ML15355A490

Columbia, Final Safety Analysis Report, Amendment 63, Chapter 2 - Site Characteristics

ML15355A490
Person / Time
Site:	Columbia
Issue date:	12/21/2015
From:	Energy Northwest
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML15356A148	List: GO2-15-159, Final Safety Analysis Report, Amendment 63, Chapter 13 -Conduct of Operations ML15355A480 ML15355A481 ML15355A486 ML15355A487 ML15355A488 ML15355A489 ML15355A490 ML15355A496 ML15355A497 ML15355A498 ML15355A499 ML15355A500 ML15355A507 ML15355A508 ML15355A509 ML15355A510 ML15355A511 ML15355A512
References
GO2-15-159
Download: ML15355A490 (258)

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COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS Section Page LDCN-09-044 2-i 2.1 GEOGRAPHY AND DEMOGRAPHY ................................................ 2.1-1 2.1.1 SITE LOCATION AND DESCRIPTION ........................................... 2.1-1 2.1.1.1 Specification of Location ............................................................. 2.1-1 2.1.1.2 Site Area Map .......................................................................... 2.1-1 2.1.1.3 Boundaries for Establishing Effluent Release Limits ........................... 2.1-2 2.1.2 EXCLUSION AREA AUTHORITY AND CONTROL .......................... 2.1-2 2.1.2.1 Authority ................................................................................ 2.1-2 2.1.2.2 Control of Activities Unrelated to Plant Operation .............................. 2.1-4 2.1.2.2.1 Industrial Development Complex ................................................ 2.1-4 2.1.2.2.2 618-11 (Wye) Waste Burial Ground ............................................. 2.1-4 2.1.2.3 Arrangements for Traffic Control .................................................. 2.1-5 2.1.2.4 Abandonment or Relocation of Roads ............................................. 2.1-5 2.1.3 POPULATION DISTRIBUTION ..................................................... 2.1-5 2.1.3.1 Population Within Ten Miles ........................................................ 2.1-6 2.1.3.2 Population Between Ten and Fifty Miles .......................................... 2.1-7 2.1.3.3 Transient Population .................................................................. 2.1-7 2.1.3.4 Low Population Zone ................................................................. 2.1-7 2.1.3.5 Population Center ..................................................................... 2.1-7 2.1.3.6 Population Density .................................................................... 2.1-7 2.

1.4 REFERENCES

........................................................................... 2.1-8 2.2 NEARBY INDUSTRIAL, TRANSPORTATION, AND MILITARY FACILITIES ................................................................................ 2.2-1 2.2.1 LOCATION AND ROUTES .......................................................... 2.2-1 2.2.2 DESCRIPTIONS ......................................................................... 2.2-3 2.2.2.1 Description of Facilities .............................................................. 2.2-3 2.2.2.2 Description of Products and Materials ............................................. 2.2-6 2.2.2.3 Pipelines ................................................................................ 2.2-7 2.2.2.4 Waterways .............................................................................. 2.2-7 2.2.2.5 Airports ................................................................................. 2.2-8 2.2.2.6 Projection of Industrial Growth ..................................................... 2.2-8 2.2.3 EVALUATION OF POTENTIAL ACCIDENTS ................................. 2.2-8 2.2.3.1 Determination of Design Basis Events ............................................. 2.2-8 2.2.3.2 Effects of Design Basis Events ...................................................... 2.2-11 2.

2.4 REFERENCES

........................................................................... 2.2-11 COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS (Continued)

Section Page 2-ii 2.3 METEOROLOGY ......................................................................... 2.3-1 2.3.1 REGIONAL CLIMATOLOGY .......................................................... 2.3-1 2.3.1.1 General Climate ....................................................................... 2.3-1 2.3.1.2 Regional Meteorological Conditions for Design and Operating Bases ....... 2.3-4 2.3.1.2.1 Severe Weather Phenomena ....................................................... 2.3-4 2.3.1.2.1.1 Heavy Rain, Snow, and Ice ..................................................... 2.3-4 2.3.1.2.1.2 Thunderstorms and Hail ......................................................... 2.3-4 2.3.1.2.1.3 Tornadoes .......................................................................... 2.3-6 2.3.1.2.1.4 Strong Winds ...................................................................... 2.3-7 2.3.1.2.1.5 High Air Pollution Potential (APP) and Dust Storm Potential ........... 2.3-8 2.3.1.2.1.5.1 Evaluation of August 11, 1955 and January 11, 1972 Dust Storms at Hanford ............................................................. 2.3-11 2.3.1.2.1.5.2 Hanford Dust Storm Climatology for Design and Operating Bases ... 2.3-13 2.3.1.2.2 Design Snow Load .................................................................. 2.3-14 2.3.1.2.3 Meteorological Data Used for Evaluation of Ultimate Heat Sink .......... 2.3-15 2.3.2 LOCAL METEOROLOGY .............................................................. 2.3-16 2.3.2.1 Data Comparisons ..................................................................... 2.3-16 2.3.2.1.1 Winds .................................................................................. 2.3-18 2.3.2.1.2 Moisture and Temperature ........................................................ 2.3-19 2.3.2.1.3 Monthly Precipitation .............................................................. 2.3-20 2.3.2.1.4 Fog .................................................................................... 2.3-20 2.3.2.1.5 Stability Summaries ................................................................. 2.3-21 2.3.2.2 Potential Influence of the Plant and Its Facilities on Local Meteorology .... 2.3-22 2.3.2.3 Local Meteorological Conditions for Design and Operating Bases ........... 2.3-23 2.3.2.4 Topographic Description ............................................................. 2.3-23 2.3.3 ONSITE METEOROLOGICAL MEASUREMENT PROGRAM ................... 2.3-23 2.3.3.1 Permanent Onsite Meteorological Tower and Instrumentation Characteristics ......................................................................... 2.3-24 2.3.3.2 Quality Assurance Program ......................................................... 2.3-26 2.3.3.2.1 Data Recovery During April 1, 1974 - March 31, 1976 ..................... 2.3-26 2.3.3.2.2 Maintenance and Calibration ..................................................... 2.3-28 2.3.3.2.3 Data Processing and Analysis .................................................... 2.3-28 2.3.3.2.4 Meteorological Monitoring Program During Plant Operation .............. 2.3-29 2.3.3.3 Other Meteorological Measurement Programs Considered for the Data Comparisons ............................................................................ 2.3-31 2.3.3.3.1 CGS Temporary Tower ............................................................ 2.3-31 COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS (Continued)

Section Page 2-iii 2.3.3.3.2 Hanford Meteorological Station .................................................. 2.3-31 2.3.3.4 Joint Stability - Wind Frequency Summaries ..................................... 2.3-31 2.3.4 SHORT TERM DIFFUSION ESTIMATES ........................................ 2.3-32 2.3.4.1 Objective ................................................................................ 2.3-32 2.3.4.2 Exclusion Area Boundary ............................................................ 2.3-32 2.3.4.3 Low Population Zone ................................................................. 2.3-33 2.3.4.4 Control Room .......................................................................... 2.3-33 2.3.4.5 Description of Sources ............................................................... 2.3-33 2.3.4.6 Control Room Intakes ................................................................ 2.3-34 2.3.4.7 Calculations ............................................................................ 2.3-34 2.3.5 LONG-TERM (ROUTINE) DIFFUSION ESTIMATES ............................. 2.3-35 2.3.5.1 Objectives ............................................................................... 2.3-35 2.3.5.2 Calculations ............................................................................ 2.3-36 2.

3.6 REFERENCES

........................................................................... 2.3-38 2.4 HYDROLOGY ENGINEERING ........................................................ 2.4-1 2.4.1 HYDROLOGIC DESCRIPTION ..................................................... 2.4-1 2.4.1.1 Site and Facilities ...................................................................... 2.4-1 2.4.1.2 Hydrosphere ............................................................................ 2.4-1 2.4.2 FLOODS .................................................................................. 2.4-4 2.4.2.1 Flood History .......................................................................... 2.4-4 2.4.2.2 Flood Design Considerations ........................................................ 2.4-4 2.4.2.3 Effects of Local Intense Precipitation .............................................. 2.4-5 2.4.3 PROBABLE MAXIMUM FLOOD ON STREAMS AND RIVERS ........... 2.4-6 2.4.3.1 Probable Maximum Precipitation ................................................... 2.4-7 2.4.3.2 Precipitation Losses ................................................................... 2.4-7 2.4.3.3 Runoff and Stream Course Models ................................................. 2.4-7 2.4.3.4 Probable Maximum Flood Flow .................................................... 2.4-8 2.4.3.5 Water Level Determinations ......................................................... 2.4-9 2.4.3.6 Coincident Wind Wave Activity .................................................... 2.4-9 2.4.4 POTENTIAL DAM FAILURES, SEISMICALLY INDUCED ................. 2.4-9 2.4.4.1 Dam Failure Permutations ........................................................... 2.4-10 2.4.4.2 Unsteady Flow Analysis of Potential Dam Failures ............................. 2.4-11 2.4.4.3 Water Level at Plant Site ............................................................. 2.4-11 2.4.5 PROBABLE MAXIMUM SURGE AND SEICHE FLOODING ............... 2.4-11 2.4.6 PROBABLE MAXIMUM TSUNAMI FLOODING .............................. 2.4-12 COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS (Continued)

Section Page 2-iv 2.4.7 ICE EFFECTS ........................................................................... 2.4-12 2.4.8 COOLING WATER CANALS AND RESERVOIRS ............................. 2.4-13 2.4.9 CHANNEL DIVERSIONS ............................................................ 2.4-13 2.4.10 FLOODING PROTECTION REQUIREMENTS ................................ 2.4-13 2.4.11 LOW WATER CONSIDERATIONS .................................................. 2.4-14 2.4.11.1 Low Flow in Streams ................................................................ 2.4-14 2.4.11.2 Low Water Resulting From Surges, Seiches, or Tsunami ..................... 2.4-15 2.4.11.3 Historical Low Water ............................................................... 2.4-15 2.4.11.4 Future Controls ....................................................................... 2.4-16 2.4.11.5 Plant Requirements .................................................................. 2.4-17 2.4.11.6 Heat Sink Dependability Requirements .......................................... 2.4-17 2.4.12 DISPERSION, DILUTION, AND TRAVEL TIMES OF ACCIDENTAL RELEASES OF LIQUID EFFLUENTS IN SURFACE WATERS ........... 2.4-17 2.4.13 GROUNDWATER ..................................................................... 2.4-18 2.4.13.1 Description and Onsite Use ........................................................ 2.4-18 2.4.13.2 Sources ................................................................................ 2.4-23 2.4.13.3 Accidental Effects.................................................................... 2.4-25 2.4.13.4 Monitoring or Safeguard Requirements .......................................... 2.4-29 2.4.13.5 Design Bases for Subsurface Hydrostatic Loadings ........................... 2.4-29 2.4.14 TECHNICAL SPECIFICATIONS AND EMERGENCY OPERATION REQUIREMENTS ..................................................................... 2.4-30 2.4.15 REFERENCES ......................................................................... 2.4-30 2.5 GEOLOGY, SEISMOLOGY, AND GEOTECHNICAL ENGINEERING ...... 2.5-1

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES Number Title Page 2-v 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site.....................................................................2.1-9 2.1-2 2000 Population Distribution by Compass Sector and Distance from the Site..........................................................2.1-12 2.2-1 Hanford Site Nuclear Facilities...............................................2.2-13 2.3-1 Average and Extremes of Climatic Elements at Hanford................2.3-43 2.3-2 Average Return Period and Existing Record for Various Precipitation Amounts and Intensity During Specified Time Periods at Hanford..............................................................2.3-45 2.3-3 Miscellaneous Snowfall Statistics (1946 through 1970)..................2.3-46 2.3-4 Tornado History Within 100 Miles of CGS................................2.3-47 2.3-5 Monthly and Annual Prevailing Directions, Average Speeds, and Peak Gusts: 1945-1970 at HMS........................................2.3-48 2.3-6 Speed and Direction of Daily Peak Gusts..................................2.3-49 2.3-7a CGS and HMS Hourly Meteorlogical Data, August 7-9, 1972 (Ultimate Heat Sink Studies)..................................................2.3-51 2.3-7b CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-52 2.3-7c CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-53 2.3-7d CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-54 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page 2-vi 2.3-7e CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-55 2.3-7f 24 Hour HMS Meteorological Profile for August 4, 1961..............2.3-56 2.3-7g Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing Second Through Thirtieth Day Pond Thermal Performance..........................................................2.3-57 2.3-7h Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing First Through Thirtieth Day Maximum Mass Loss........................................................................2.3-58 2.3-8a Summary of CGS Onsite Meteorological Data Collected During the First and Second Annual Cycles as Compared to Corresponding Hanford Meterological Station Data......................2.3-59 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975).................................................2.3-61 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970)..........................................2.3-66 2.3-10 Percent Frequency of Occurrence of Wind Direction at the Hanford Reservation............................................................2.3-70 2.3-11 Persistence of Wind Direction in One Sector (22.5 Degrees) from 4/74 through 3/75 at 33-ft Level......................................2.3-72 2.3-12 Persistence of Wind Direction in Two Sectors (45 Degrees) from 4/74 through 3/75 at CGS for 33-ft Level...........................2.3-74 2.3-12a Longest Persistence of Wind Direction in One (22.5 Degrees) and Two (45 Degrees) Sectors During First and Second Annual Cycles at 33-ft Level.................................................2.3-76 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2

SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page 2-vii 2.3-13 Percent Frequency of Occurrence of Wind Speed at the Hanford Reservation............................................................2.3-77 2.3-14 Diurnal Variation of 33-ft Elevation Dry Bulb Temperature (F°) at CGS and Monthly Average Dry Bulb Temperature (F°) at the Hanford Reservation.......................................................2.3-79 2.3-15 Diurnal Variation of 33-ft Elevation Wet Bulb Temperature (F°) at CGS and Monthly Average Wet Bulb Temperature (F°) at the Hanford Reservation............................................................2.3-80 2.3-16 Diurnal Variation of 33 ft Elevation Dew Point Temperature (F°) at CGS and Monthly Average Dew Point Temperature (F°) at the Hanford Reservation.......................................................2.3-81 2.3-17 Frequency of Occurrence, Dry Bulb Temperature (F°) Versus Time of Day from 4/74 through 3/75 for 33-ft Level....................2.3-82 2.3-18 Frequency of Occurrence, Wet Bulb Temperature (F°) Versus Time of Day from 4/74 through 3/75 for 33-ft Level....................2.3-83 2.3-19 Frequency of Occurrence, Dew Point Temperature (F°) Versus Time of Day from 4/74 through 3/75 for 33-ft Level....................2.3-84 2.3-20 Monthly Averages of Psychrometric Data Based on Period of Record (1950-1970).........................................................2.3-85 2.3-21 Diurnal Variation of Precipitation Intensity at CGS and Monthly Total Precipitation at the Hanford Reservation.................2.3-86 2.3-22 Frequency of Occurrence, Precipitation Versus Time of Day from 4/74 through 3/75 at CGS..............................................2.3-87 2.3-22a Annual Frequency of Occurrence of Wind Direction and Wind Speed Versus Precipitation Intensity.................................2.3-88 COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page LDCN-13-067 2-viii 2.3-23 Statistics on Fog at the Hanford Meteorology Station .................... 2.3-90 2.3-24 Percent Frequency Distribution of Wind Speeds During Hourly Observations of Fog at Pasco and at HMS ................................. 2.3-91 2.3-25 Percent Frequency of Occurrence of Stability at the Hanford Reservation............................................................ 2.3-92 2.3-26 Frequency of Occurrence T (F/200 ft) Versus Time of Day from 4/74 through 3/75 at CGS between 245 and 33-ft Levels ......... 2.3-94 2.3-27 Frequency of Occurrence, Sigma () Versus Time of Day from 4/74 through 3/75 at CGS for 33-ft Level .................................. 2.3-95 2.3-28 Joint Frequency Distribution of Wind Speed and Direction ............. 2.3-96 2.3-28A Joint Frequency Distribution of Wind Speed and Direction ............. 2.3-100 2.3-29 through 2.3-32 DELETED 2.3-33 Exclusion Area Boundary Accident /Q Desert Sigmas ................. 2.3-105 2.3-33a Exclusion Area Boundary /Q Values Desert Sigmas w/ Meander .... 2.3-106 2.3-34 Exclusion Area Boundary Accident /Q P-G Sigmas .................... 2.3-107 2.3-34a Exclusion Area Boundary /Q Values Pasquill-Gifford Sigmar w/ Meander and Building Wake Credit ..................................... 2.3-108 2.3-35 Low Population Zone Accident /Q Desert Sigmas ...................... 2.3-109 2.3-36 Low Population Zone Accident /Q P-G Sigmas ......................... 2.3-110 2.3-37 Control Room, Exclusion Area Boundary and Low Population Zone /Qs (S/m3) .......................................... 2.3-111 COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page LDCN-13-067 2-ix 2.3-38a CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-112 2.3-38b CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-113 2.3-38c CGS Calculations, Terrain Features, Desert Sigmas ..................... 2.3-114 2.3-38d CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-115 2.3-38e CGS Calculations, Terrain Features, Desert Sigmas ..................... 2.3-116 2.3-38f CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-117 2.3-39a DELETED ....................................................................... 2.3-118 through 2.3-39f

2.3-40 Frequency of Wind Resuspension Periods at Hanford (1953-1970) ...................................................................... 2.3-119 2.3-41 Dust Concentration Dependency on Wind Speed and Direction at Hanford 1953-1970 .......................................................... 2.3-120 2.3-42 Hours Satisfying Dust Storm Criteria at Hanford (1953-1970) ......... 2.3-121 2.4-1 Major Columbia River Basin Dams ......................................... 2.4-35 2.4-2 Columbia River Temperatures Near Columbia Generating Station .... 2.4-36 2.4-3 Downstream Surface Water Users ........................................... 2.4-37 2.4-4 Mean Discharges in CFS of Columbia River Below Priest Rapids Dam, Modified to 1970 Conditions ................................ 2.4-38 2.4-5 Dependable Yield, Columbia River Below Priest Rapids Dam, Washington ....................................................................... 2.4-39 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page LDCN-05-050 2-x 2.4-6 Major Geologic Units in the Hanford Region and Their Water-Bearing Properties......................................................2.4-40

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES Number Title 2-xi 2.1-1 General Area, 0-20 Miles 2.1-2 General Area, 0-50 Miles 2.1-3 Overall Site Plan

2.1-4 Project Area Map - 10 Mile Radius

2.1-5 Project Area Map - 50 Mile Radius

2.1-6 2000 Population in Communities Around Site 2.1-7 Transportation and Topographic Features of Low Population Zone 2.2-1 Hanford Reservation Road System

2.2-2 Hanford Reservation Railroad System 2.2-3 Federal Airways and Instrument Approaches/Departures 2.3-1 Rainfall Intensity, Duration, and Frequency Based on the Period 1947-69 at Hanford 2.3-2 Greatest Depth of Snow on Ground During 24 of 25 Winters of Record at Hanford 1946-47 through 1969-70 2.3-3 Distribution of Characterized Tornadoes in 20-Year Period (1950-69) 2.3-4 Peak Wind Gust Return Probability Diagram 2.3-5 Dust Occurrences Per Wind Speeds to 400 ft Heights 2.3-6 Near-Surface Airborne Dust Concentration as a Function of Average Air Velocity COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES (Continued)

Number Title 2-xii 2.3-7 Monthly Hourly Average of Temperature and Relative Humidity (Sheets 1 through 3) 2.3-8 Probability (%) that the First Hourly Observation of an Inversion will Mark the Beginning of an Inversion Run of N Hr (Sheets 1 through 4) 2.3-9 Topographic Cross Sections of Region Surrounding Site 2.3-10 Yearly Hourly Average of Temperature and Relative Humidity 2.3-11 Cumulative (%) Frequency of Hourly Centerline /Q at Site Boundary Circular Distance of 1.212 Miles From Source (April 1974-March 1975) 2.3-12 Cumulative (%) Frequency of Hourly Centerline /Q at Site Boundary Circular Distance of 1.212 Miles From Source (April 1975-March 1976) 2.3-13 Cumulative (%) Frequency of Occurrence of /Q For Postulated Accidents of 8, 16, 72, and 624 Hr At Outer Boundary of LPZ (3.0 Miles from Source) (April 1974-March 1975) 2.3-14 Cumulative (%) Frequency of Occurrence of /Q for Postulated Accidents of 8, 16, 72, and 624 Hr at Outer Boundary of LPZ (3.0 Miles from Source) (April 1975-March 1976) 2.3-15 Annual Average /Q by Sector at the Site Boundary for First and Second Annual Cycle Data 2.4-1 Hydrographic Map

2.4-2 Topographic Map of Site and Surrounding Area

2.4-3 Detailed Contours Near the Site

2.4-4 Discharge and Temperature of the Columbia River at Priest Rapids 2.4-5 Columbia River Water Surface Profiles River Miles 323 to 358 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES (Continued)

Number Title LDCN-03-058 2-xiii 2.4-6 Safety-Related Building Roof Plans and Sections (Sheets 1 through 5) 2.4-7 PMF Hydrograph due to Thunderstorm PMP 2.4-8 Probable Maximum Precipitation Drainage Basin 2.4-9 Probable Maximum Precipitation Channel Cross Sections

2.4-10 Water Surface Profile

2.4-11 Effective Fetch Diagram

2.4-12 Computed Long-Term Temperature Trends on the Columbia River at Rock Island Dam (1938-1962) 2.4-13 River Elevation at Low Flows - River Mile 352

2.4-14 Duration Curves Columbia River, Priest Rapids Dam 2.4-15 Frequency Curves of High and Low Flows for the Columbia River Below Priest Rapids Dam 2.4-16 Location of Intake and Discharge 2.4-17 Monitoring Well Locations (September 1975) 2.4-18 Hanford Reservation Water Table Map (December 1975) 2.4-19 Groundwater Contours Assuming Construction of the Ben Franklin Dam 2.4-20 Hanford Reservation Water Table Map (January 1944) 2.4-21 Hydraulic Conductivities in the Unconfined Aquifer 2.4-22 Nitrate (NO3) Concentrations (December 1976)

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES (Continued)

Number Title LDCN-05-050 2-xiv 2.4-23 Gross Beta Concentrations (December 1976) 2.4-24 Tritium (3H) Concentrations (December 1976) 2.4-25 Pasco Basin Uppermost Confined Aquifer Potential Map (1970) 2.4-26 Hanford Reservation Water Table Map (September 1973) 2.4-27 Well Hydrographs (Sheets 1 and 2)

2.4-28 Site Topographic Map

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-03-023 2.1-1 Chapter 2

SITE CHARACTERISTICS

2.1 GEOGRAPHY AND DEMOGRAPHY 2.1.1 SITE LOCATION AND DESCRIPTION

2.1.1.1 Specification of Location Columbia Generating Station (CGS) is located in the southeast area of the U.S. Department of Energy's (DOE) Hanford Site in Benton County, Washington. The site is approximately 3 miles west of the Columbia River at River Mile 352, approximately 10 miles north of north Richland, 18 miles northwest of Pasco, and 21 miles northwest of Kennewick (Figures 2.1-1 and 2.1-2).

The reactor is located at 46° 28' 18" north latitude and 119° 19' 58" west longitude. The approximate Universal Transverse Mercator coordinates are 5,148,840 meters north and 320,930 meters east.

2.1.1.2 Site Area Map The CGS site area is that real estate over which Energy Northwest has the legal right to control access. It is the area enclosed by the exclusion area boundary plus the plant property lines as shown in Figure 3-1 of the Offsite Dose Calculation Manual (ODCM). The property line and nearby industrial facilities are shown in Figure 2.1-3. Industrial facilities located in the site area are the H. J. Ashe Substation and Energy Northwest's Nuclear Projects 1 and 4 (WNP-4 was terminated in January 1982, and WNP-1 was terminated in May 1994). Highway and railway facilities located within the site area are shown in Figure 2.1-3. The relative locations of the plant structures are shown in Figure 1.2-1.

The boundary of the exclusion area is a circle with its center at the reactor and a radius of 1950 m. Ownership and control of the land outside the CGS property line but within the site exclusion area are discussed in Section 2.1.2. The site is situated near the middle of the relatively flat, essentially featureless plain, which is best described as a shrub steppe with sagebrush interspersed with perennial native and introduced annual grasses extending in a northerly, westerly, and southerly direction for several miles. The plain is characterized by slight topographic relief of approximately 20 ft across the plant site.

The dominant topographic features in the area are the Rattlesnake Hills, 13 to 15 miles west southwest, 3200 ft above the elevation of the plant site; Gable Mountain, approximately COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-13-050 2.1-2 10 miles northwest of the site and about 670 ft above the site grade; and the steep river cut bluffs forming the east bank of the Columbia River, approximately 3.5 miles east of the site (Figure 2.1-1). 2.1.1.3 Boundaries for Establishing Effluent Release Limits The boundary for establishing effluent release limits (unrestricted area boundary as defined in 10 CFR Part 20) is the site area boundary as shown in the ODCM, Figure 3-1. The site area is the area enclosed by the exclusion area boundary and the plant property lines that fall outside the exclusion area. All area within the site area boundary is considered a controlled area as defined by 10 CFR 20.1003. A number of restricted areas (as defined in 10 CFR 20.1003) are associated with CGS. The primary CGS restricted area is located within the plant security fence which also is the boundary of the protected area (as defined in 10 CFR 73.2). This is shown as the double fence line in Figure 1.2-1. Unescorted access to the protected area is controlled by CGS security staff. Other restricted areas include the Independent Spent Fuel Storage Installation, stormwater ponds, Plant Support Facility calibration laboratory, Warehouse No. 5, the cooling tower sediment disposal area, and Building 167 on the WNP-4 site. Access to these secondary restricted areas is controlled by locks and fences. Temporary restricted areas may be established and removed as dictated by activities at CGS. 2.1.2 EXCLUSION AREA AUTHORITY AND CONTROL 2.1.2.1 Authority Energy Northwest leased 1089 acres from the DOE, within the DOE Hanford Site, to be used for CGS. A letter from the DOE Richland Operations office to the Managing Director of Energy Northwest (Reference 2.1-1) advises that the DOE has the authority to sell or lease land on the Hanford Site and the letter further states This Authority is contained in Section 120 of the Atomic Energy Community Act of 1955, as amended, and Section 161g of the Atomic Energy Act of 1954, as amended. There is also general federal disposal authority available under the Federal Property Administrative Services Act of 1949, as amended. The 1950-m radius exclusion area extends beyond the CGS property lines and overlaps DOE lands as well as the additional land leased by Energy Northwest for the construction of the WNP-1 and WNP-4 projects (see Figure 2.1-3 and ODCM Figure 3-1). All land outside the Energy Northwest leased property but within the exclusion area is managed by the DOE. In recognition of the requirement specified in 10 CFR 100.3(a) [Now 100.3] that a licensee have control over access to the exclusion area, the following terms have been incorporated as Article 7 of the site property lease agreement between Energy Northwest and the DOE (as modified in 1975):

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-11-027 2.1-3 Nothwithstanding any provisions of this lease to the contrary, the Administration [Energy Research and Development Administration -- now DOE] agrees that the Supply System [now Energy Northwest] has the authority to determine all activities within the exclusion area within the meaning of 10 CFR Section 100.3(a) [Now 100.3], including the authority to remove a personnel and property from the area. The Supply System agrees that it will exercise such authority in a manner so as not to preclude the Administration from undertaking any action or activity within the exclusion area that is permissible under the provisions of 10 CFR Section 100.3(a) [Now 100.3]. As used herein, the term "exclusion area" includes both the leased and nonleased portions of the exclusion area.

Therefore, any actions such as public access and actions concerning mineral rights and easements taken within the exclusion area but outside the leased property are under the control of the DOE with the provision that Energy Northwest has the legal right to control access of individuals to the exclusion area if necessary. All rail shipments on the track which traverses the property (Figure 2.1-3) are also under control of the DOE and are also subject to the above provision and controls imposed by Energy Northwest Security.

The only paved roads that traverse the exclusion area of CGS are the CGS, WNP-1, and WNP-4 facility access roads shown in Figure 2.1-3. Access by land from outside of the Hanford Site to the plant site is over DOE roads. Travel within the exclusion area on the access roads will be under the authority of Energy Northwest.

In the event that evacuation or other control of the exclusion area should become necessary, appropriate notice will be given to the DOE-Richland Operations Office for control of non-Energy Northwest originated activities.

The above provisions provide the necessary assurance that the exclusion area is properly controlled. If Energy Northwest should decide that an easement would be useful in ensuring continued control, there is a provision in Article 5(b) of the lease as follows: Subject to the provisions of Section 161g of the Atomic Energy Act of 1954, as amended, the Commission has authority to grant easements for rights-of-way for roads, transmission lines and for any other purpose, and agrees to negotiate with Energy Northwest for such rights-of-way over the Hanford Operations Area as are necessary to service the Leased Premises. Pursuant to this provision Energy Northwest could obtain an easement over the exclusion area in question from the DOE, which would ensure that no permanent structures or other activities inconsistent with the exclusion area would be carried on therein.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 LDCN-09-044 2.1-4 2.1.2.2 Control of Activities Unrelated to Plant Operation In accordance with, and as defined by 10 CFR 100.3, Energy Northwest has the authority to determine all activities within the exclusion area, including the authority to remove all personnel and property from the area. The following activities unrelated to plant operation are permitted within the exclusion area: 2.1.2.2.1 Industrial Development Complex Energy-Northwest is conducting site restoration and economic development (such as leasing of excess facilities for office space and manufacturing) activities at the WNP-1 and WNP-4 sites (the WNP-1 and WNP-4 sites are also leased from the DOE and controlled by Energy Northwest). The number of personnel at the WNP-1 and WNP-4 sites varies. However, coordination of activities within the exclusion area is under the control of Energy Northwest and the CGS emergency plan. This includes notification and evacuation considerations in the event of an emergency at CGS. 2.1.2.2.2 618-11 (Wye) Waste Burial Ground The 618-11 site is a DOE waste burial ground, encompassing an eight-acre parcel directly adjacent to Energy Northwest leased land (see Figure 2.1-3) and located wholly within the CGS exclusion area. The DOE and its site contractor are approved to perform non-intrusive surveillance and characterization activities to obtain data and information necessary for planning future intrusive activities and remediation strategies. These activities are necessary to meet the 618-11 site remediation and closeout milestone of September 2018 as delineated in the Hanford Federal Facility Agreement and Consent Order. All 618-11 site activities are controlled by DOE in accordance with 10 CFR Chapter III. DOE has responsibility for the 618-11 site documented safety analysis (DSA) in accordance with 10 CFR 830.204. The currently approved DSA and its associated technical safety requirements (TSR) establish the safety basis and assess the environmental impact of the non-intrusive activities within the site. The soil overburden covering the caissons and vertical pipe units at the 618-11 site is identified as a passive design feature that serves a mitigative function. Existing soil overburden shall not be removed. A memorandum of understanding (MOU) has been established between the DOE 618-11 site contractor and Energy Northwest for communication and mutual support for the non-intrusive activities at the site. The MOU delineates the requirements for the site contractor to inform Energy Northwest of plans, schedules, manning, and other matters pertaining to the non-intrusive site activities. In addition, the MOU defines Energy Northwest requirements for contractor notification of CGS events with the potential to affect the 618-11 site operation and/or personnel. Communication includes notification and evacuation considerations in the event of an emergency at CGS.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 LDCN-09-044 2.1-5 In the event of a 618-11 site emergency, including the 618-11 site design basis event, the 618-11 site is subject to control by the DOE. Control includes notifications, implementation of required actions, and communication of recommendations to protect the health and safety of CGS personnel and the public within and beyond the Hanford reservation boundaries. The non-intrusive activities, analyzed 618-11 site events, and the design basis event associated with the non-intrusive activities, have been assessed and approved by DOE. In addition, Energy Northwest has performed an evaluation of the 618-11 site releases that would occur from the postulated design basis event. The evaluation, using NRC radionuclide transport methodology and CGS meteorological data, has confirmed that the potential 618-11 site releases will not adversely impact Structures, Systems, and Components or credited operator actions. Implementation of DOE approved non-intrusive activities at the 618-11 site will not affect the operation of CGS, and thus, will not result in a significant hazard to the health and safety of the public from CGS's operation.

2.1.2.3 Arrangements for Traffic Control The only roads within the exclusion area are the Energy Northwest access roads. These roads are normally used only by employees and visitors associated with the CGS, WNP-1, and WNP-4 facilities, DOE, and DOE contractors. The security force, with offsite assistance as required, controls traffic during emergencies.

2.1.2.4 Abandonment or Relocation of Roads There were no public roads transversing the exclusion area that had to be abandoned or relocated as a result of the construction of CGS.

2.1.3 POPULATION DISTRIBUTION

Table 2.1-1 presents the compass sector population estimates for 1980 and the forecasts for the same compass sectors by decade from 1990 to 2030.* Cumulative totals are also shown in Table 2.1-1. This table may be keyed to Figures 2.1-4 and 2.1-5, which show the sectors and major population centers within 10 and 50 miles of the site. As can be seen in Figure 2.1-6, population centers, within 50 miles of the site include the Tri-Cities area of Richland, Pasco, and Kennewick; Moses Lake; Hermiston; and the communities lying along the Yakima River

• Population estimates out to 50 miles were derived to serve the licensing requirements of WNP-1, CGS, and WNP-4. Therefore, estimates were made relative to the centroid of the triangle formed by the three reactors. This point is located 2800 ft east of CGS and has coordinates longitude 119º 19' 18" west, latitude 46° 28' 19" north. This shift does not affect the overall accuracy or applicability of the population distribution projections.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-14-009,13-067 2.1-6 from Prosser to Toppenish. Figure 2.1-4 shows that there are no towns located within 10 miles of the site, with the exception of a small part of Richland.

The 1990 to 2030 forecasts presented here (Reference 2.1-2) are based on a. 1979 population figures provided by the Washington State Office of Financial Management,

b. Benton and Franklin County Traffic Analysis Zone population distributions,

c. Computed annual average area growth rates from 1975 through 1979 which were utilized to obtain the total 1980 population estimated for each area, and

d. County forecasts prepared by the Bonneville Power Administration. (References 2.1-3 and 2.1-4).

Table 2.1-2 presents the compass sector population estimates for 2010 based on U.S. Census Bureau data (Reference 2.1-5). See also Figures 2.1-4 and 2.1-5.

2.1.3.1 Population Within Ten Miles An estimated 3000 people live within 10 miles of the site. The nearest inhabitants occupy farms which are located east of Columbia River and are thinly spread over five compass sectors. There are no permanent inhabitants located within 3 miles of the site.

No significant changes in land use within five miles are anticipated. The Hanford Site is expected to remain dedicated primarily to industrial use without private residences. No change in the use of the land east of the Columbia River is expected since it currently is irrigated to about the maximum amount practicable. The primary increase in population within the 10-mile radius is expected to be in the area south and south-southeast of the plant (see Figure 2.1-4).

2.1.3.2 Population Between Ten and Fifty Miles As indicated in Table 2.1-2, about 450,000 people were estimated to be living within a 50-mile radius of CGS in 2010. Projections for the 10-50 mile region are shown in Table 2.1-1 which is based on earlier (1979-1980) population counts.

2.1.3.3 Transient Population The transient population consists of agricultural workers needed for harvesting crops produced in the region, industrial and construction workers, and sportsmen engaged in hunting, fishing, COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 2.1-7 and boating. A description of the transient population is discussed in Section 5.6 of the CGS Emergency Plan.

2.1.3.4 Low Population Zone The low population zone (LPZ) [see 10 CFR 100.3(b)] for CGS is defined as all land within a 3-mile radius of the reactor. This LPZ was selected on the basis that it is not expected to have a large population in the future and that effective protective measures could be established. As shown in Table 2.1-2, no permanent residents are located within a 3-mile radius of the reactor, and none are anticipated in the future.

There are no public facilities or institutions such as schools and hospitals within a 3-mile radius of the plant. The transportation facilities and topographic features of the LPZ are shown in Figure 2.1-7.

2.1.3.5 Population Center The nearest population center is the City of Richland, 12 miles to the south.

2.1.3.6 Population Density In 2000, the population densities within the 10, 20, and 30-mile radii were 9, 96, and 73 people per square miles, respectively. In 2030, the densities out to the same distances are estimated to be 13, 123, and 84, respectively, based on the projections in Table 2.1-1.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-14-009 2.1-8 2.

1.4 REFERENCES

2.1-1 Letter from Atomic Energy Commission, Richland Operations Office, to Managing Director of the Supply System, Washington Public Power Supply System,

Subject:

Appendix 2P, November 25, 1970.

2.1-2 Yandon, K. E., Projections and Distributions of Populations Within a 50-Mile Radius of Washington Public Power Supply System Nuclear Projects Nos. 1, 2, and 4 by Compass Direction and Radii Intervals, 1970-2030, October 1980.

2.1-3 Bonneville Power Administration, U.S. Department of Energy, Washington,

Subject:

Population, Employment and Household Projections to 2000 by County, July 1979.

2.1-4 Bonneville Power Administration, U.S. Department of Energy, Oregon Population, Employment and Household Projections to 2000 by County.

2.1-5 Washington State Office of Financial Management, Forecasting Division (2012). Small Area Estimate Program: Census Block Groups [SAEP_ColGenFac_Sectors_2000-2012.xls]. Via communication with M. Mohrman, Washington Office of Financial Management, July 2013; Oregon Population Data Estimates 2010 provided by Portland State University, Population Research Center, C. Rynerson, in collaboration with the M. Mohrman at Washington State Office of Financial Management, March 2014.

Table 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site 1980 1990 2000 2010 2020 2030 Distance Cumulative (miles) Direction (compass segment) Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003LDCN-03-023 2.1-90-3 All 0 0 0 0 0 0 0 0 0 0 0 0 3-5 N-NNE 0 0 0 0 0 0 0 0 0 0 0 0 NE 10 10 35 35 48 48 52 52 55 55 86 86 ENE 22 32 43 78 56 104 60 112 63 118 64 150 E 22 54 43 121 56 160 60 172 63 181 64 214 ESE 22 76 43 164 56 216 60 232 63 244 64 278 SE 4 80 6 170 9 225 11 243 11 255 12 290 SSE-NNW 0 80 0 170 0 225 0 243 0 255 0 290 5-10 N 26 106 58 228 77 302 83 326 87 342 88 378 NNE 83 189 126 354 152 454 162 488 170 512 172 550 NE 155 344 198 552 224 678 240 728 252 764 254 804 ENE 114 458 157 709 177 855 190 918 200 964 202 1006 E 135 593 200 909 257 1112 276 1194 290 1254 293 1299 ESE 168 761 276 1185 341 1453 366 1560 385 1639 389 1688 SE 190 951 406 1591 536 1989 575 2135 604 2243 610 2298 SSE 45 996 253 1844 308 2297 330 2465 347 2590 350 2648 S 50 1046 272 2116 483 2780 518 2983 544 3134 550 3198 SSW 235 1281 535 2651 809 3589 867 3850 911 4045 920 4118 SW 25 1306 25 2676 25 3614 27 3877 28 4073 29 4147 WSW-NNW 0 1306 0 2676 0 3614 0 3877 0 4073 0 4147 10-20 N 332 1638 371 3047 398 40112 427 4304 449 4522 454 4601 NNE 328 1966 371 3418 397 4409 426 4730 447 4969 452 5053 NE 399 2365 562 3980 588 4997 630 4360 662 5631 669 5722 ENE 792 3157 835 4815 855 5852 917 6277 964 6595 974 6696 E 461 3618 479 5294 544 6396 583 6860 613 7208 619 7315 ESE 192 3810 430 5724 576 6972 618 7478 650 7858 657 7972 SE 4155 7965 5221 10945 5821 12793 6242 13720 6561 14419 6627 14599 SSE 49178 57143 63483 74428 70917 83710 76043 89763 79932 94351 80734 95333 S 28943 86086 37672 112100 45434 129144 48717 138480 51208 145559 51722 147055 SSW 1592 87678 1772 113872 1922 131066 2061 140541 2166 147725 2188 149243 SW 3106 90784 3597 117469 894 134960 4175 144716 4389 152114 4433 153676 WSW 950 91734 1048 118517 1108 136068 1188 145904 1248 153362 1260 154936 W 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 WNW 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 NW 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 NNW 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 Table 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site (Continued) 1980 1990 2000 2010 2020 2030 Distance Cumulative (miles) Direction (compass segment) Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003LDCN-03-023 2.1-10 20-30 N 1501 93235 1837 120354 2055 138123 2203 148107 2316 155678 2339 157275 NNE 5759 98994 6487 126841 7123 145246 7638 155745 8029 163707 8110 165385 NE 2015 101009 2174 129015 2274 147520 2438 158183 2563 166270 2589 167974 ENE 1717 102726 1760 130775 1786 149306 1915 160098 2013 168283 2033 170007 E 151 102877 194 130969 220 149526 236 160334 248 168531 250 170257 ESE 153 103030 240 131209 305 149831 327 160661 344 168875 348 170605 SE 6138 109168 6512 137721 6738 156569 7225 167886 7594 176469 7670 178275 SSE 24116 133284 32559 170280 36360 192929 38987 206873 42032 218501 42454 220729 S 187 133471 678 170958 975 193904 1045 207918 1098 219599 1109 221838 SSW 875 134346 1218 172176 1426 195330 1529 209447 1607 221206 1623 223461 SW 6165 140511 7147 179323 7737 203067 8296 217743 8720 229926 8808 232269 WSW 1626 142137 1799 181122 1908 204975 2046 219789 2151 232077 2173 234442 W 1191 143328 1325 182447 1429 206404 1532 221321 1610 233687 1626 236068 WNW 185 143513 280 182727 297 206701 318 221639 334 234021 338 236406 NW 40 143553 44 182771 48 206749 51 221690 54 234075 55 236461 NNW 182 143735 200 182971 218 206967 234 221924 246 234321 249 236710 30-40 N 980 144715 1096 184065 1127 208094 1208 223132 1270 235591 1283 237993 NNE 3198 147913 3663 187728 3983 212077 4271 227403 4490 240081 4536 242529 NE 650 148563 800 188528 745 212822 799 228202 846 240927 850 243379 ENE 421 148984 447 188975 475 213297 509 228711 535 241462 540 243919 E 128 149112 136 189111 141 213438 152 228863 160 241622 162 244081 ESE 167 149279 176 189287 182 213620 195 229058 205 241827 208 244289 SE 464 149743 484 189771 497 214117 533 229591 560 242387 566 244855 SSE 592 150335 844 190615 955 215072 1023 230615 1076 243463 1087 245942 S 4680 155015 5653 196268 6368 221440 6828 237442 7172 250635 7250 253192 SSW 256 155271 424 196692 529 221969 567 238009 596 251231 602 253794 SW 473 155744 661 197353 786 222755 842 238851 885 252116 894 254688 WSW 21871 177615 24729 222082 26890 249645 28833 267684 30362 282478 30665 285353 W 3578 181193 3949 226031 4273 253918 4582 272266 4816 287294 4864 290217 WNW 1399 182592 1459 227490 1579 255497 1693 273959 1780 289074 1798 292015 NW 703 183295 770 228260 836 256333 896 274855 942 290016 952 292967 NNW 1575 184870 1738 229998 1899 258232 2036 276891 2140 292156 2161 295128 40-50 N 17872 202742 19730 249728 21572 279804 23130 300021 24312 316468 24556 319684 NNE 893 203635 1019 250747 1121 280925 1202 301223 1263 317731 1275 320959 NE 926 204561 1139 251886 1275 282200 1367 302590 1437 319168 1451 322410 ENE 213 204774 243 252129 375 282575 402 302992 423 319591 427 322837 E 241 205015 258 252387 268 282843 287 303279 302 319893 305 323142 ESE 864 205879 925 253312 961 283804 1030 304309 1083 320976 1095 324237 Table 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site (Continued) 1980 1990 2000 2010 2020 2030 Distance Cumulative (miles) Direction (compass segment) Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003LDCN-03-023 2.1-11 40-50 (cont.) SE 2084 207963 2245 25557 2349 286153 2518 306827 2646 323622 2673 326910 SSE 1740 209703 1920 257477 2072 288225 2222 309049 2336 325958 2359 329269 S 16540 226243 16406 273883 17708 305933 18987 328036 19958 345916 20158 349427 SSW 2610 228853 2895 276778 2972 308905 3186 331222 3349 349265 3428 352855 SW 421 229274 443 277221 476 309381 509 331731 535 349800 541 353396 WSW 809 230083 892 278113 965 310346 1035 332766 1088 350888 1099 354495 W 18515 248598 20481 298594 22176 332525 23780 356546 24996 375884 25247 379742 WNW 1742 250340 1903 300497 2043 334568 2191 358737 2303 378187 2326 382068 NW 812 251152 859 301356 905 335473 970 359707 1020 379207 1030 383098 NNW 532 251684 587 301943 642 336115 688 360395 723 379930 730 383828

Table 2.1-2 2010 Population Distribution by Compass Sector and Distance from the Site LDCN-14-009,13-067 2.1-12 COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 Distance (miles) Direction (compass segment) 2010 Population Distance (miles) Direction (compass segment) 2010 Population Distance (miles) Direction (compass segment) 2010 Population 0-3 ALL 0 5-10 N 16 10-20 N 136 5-10 NNE 78 10-20 NNE 742 3-4 NNE 0 5-10 NE 248 10-20 NE 1699 3-4 ENE 0 5-10 ENE 213 10-20 ENE 934 3-4 E 1 5-10 E 298 10-20 E 680 3-4 ESE 0 5-10 ESE 308 10-20 ESE 513 3-4 SE-NNW 0 5-10 SE 588 10-20 SE 16219 5-10 SSE 239 10-20 SSE 95379 4-5 NNE 1 5-10 S 376 10-20 S 38669 4-5 NE 18 5-10 SSW 548 10-20 SSW 7516 4-5 ENE 19 5-10 SW 16 10-20 SW 1232 4-5 E 27 5-10 WSW-NW 0 10-20 WSW 11 4-5 ESE 25 5-10 NNW 1 10-20 WNW 0 4-5 SE 0 10-20 NNW 1 4-5 SSE-NNW 0 10-20 NW - W 0 0-5 TOTAL 91 0-10 TOTAL 3020 0-20 TOTAL 166751 20-30 N 1098 30-40 N 1138 40-50 N 37171 20-30 NNE 13285 30-40 NNE 3802 40-50 NNE 782 20-30 NE 1237 30-40 NE 210 40-50 NE 705 20-30 ENE 3638 30-40 ENE 302 40-50 ENE 164 20-30 E 53 30-40 E 121 40-50 E 48 20-30 ESE 509 30-40 ESE 686 40-50 ESE 188 20-30 SE 18611 30-40 SE 343 40-50 SE 1415 20-30 SSE 50050 30-40 SSE 201 40-50 SSE 310 20-30 S 1710 30-40 S 8330 40-50 S 30053 20-30 SSW 131 30-40 SSW 236 40-50 SSW 5441 20-30 SW 11225 30-40 SW 1552 40-50 SW 217 20-30 WSW 1475 30-40 WSW 41107 40-50 WSW 4428 20-30 W 50 30-40 W 934 40-50 W 22691 20-30 WNW 205 30-40 WNW 6111 40-50 WNW 26 20-30 NW 611 30-40 NW 2478 40-50 NW 619 20-30 NNW 443 30-40 NNW 3870 40-50 NNW 1622 0-30 TOTAL 271082 0-40 TOTAL 342503 0-50 TOTAL 448383 Table based on April 2010 Census Bureau counts.

General Area, 0 - 20 Miles1-1.202.603099Form No. 960690Amendment 55May 2001Figure.veR.oN .warDSandpitEltopiaRanchWaterTank1717395Hathaway800Basin City770170RanchSavageIslandBasin CityRanchRanchFrischnechtShanoRadioTowerRadio TowerMesaSMITH CANYONOLD MAIDWaterTankOthelloAir Force StaCactusSaddle GapPotholesEastCanalUS Government RRMathewsCornerRINGOLD FLAT260CampLakeScooteneyReservoirT LakeWASHTUCNA COULEEClarkPondP A R A D I S E F L A T SCanalEagleLakesSURVIVAL TRAINING AREAJUNIPER FORESTWaterTankGravelpitGravelpitRadioTowerRadioTowerHumorist12QuarryRYE GRASS COULEEWaterTank124GravelpitGladePascoSubstaSubstaIce Harbor DamJACKASSMOUNTAINWaterTankWooded IslandESQUATZEL COULEEDiversionChannelEsquatzelRichlandPasco WestVista521ColumbiaPointTri-CitiesAirport407Potholes CanalWTPipeline395SacajaweaState ParkSNAKE RIVERUNION PACIFICHedgesWTSubsta14VistaColumbia CanalKENNEWICKFranklin Co Irr Can NORTHERNColumbia CanalBADGER MOUNTAINCanalIslandViewRichland391221Grain elevatorGrain elevatorGravelpit240224RanchRadioTowerGrain elevatorGrain elevatorBadger CanyonBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksKelly GulchHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONGibbonWhitstrandChandler ButteSunnyside CanalChaffeePumpingStationRanchRanchRoza CanalUNION PACIFICProsserSpringWebber CanyonRoza CanalBlack CanyonSpring CrSnipes Creek2424324W A H L U K E S L O P ERanchChristensen Bros840Mattawa750White BluffsSADDLE MOUNTAINNATIONAL WILDLIFE REFUGECABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsHanford DitchTowersWaterTankBensonSpringLockeIslandSubstaBENTON COFRANKLIN CO82DamNorthProsser82121282KionaGravelpit18218212ChandlerIslandViewSacajaweaState ParkRoute 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.FinleyProsser694MCNARY NATIONALWILDLIFE REFUGEWALLA StevensCountryChristianCountry HavenEdwin MarkumBig RiverCOLD CREEK VALLEYH A N F O R D R E S E R V A T I O NYAKIMA RIVERIowa FlatsN Power Plant LoopColumbia Generating StationKinder-CareKiBeBurbank HiwoodGRANT CO20 Statute Miles151050530 Kilometers25151050520SCALERailroadPipeline PowerlineMedium Duty Road Light Duty RoadHeavy Duty Road395260Landplane AirportLanding AreaFederal Route MarkerState Route Interstate Route80NPark or ReservationBoundarySandpit or GravelpitPopulated PlacesRadio Tower, WellLatitude/LongitudeEmergency CenterLEGEND5 MILES10 MILES20 MILESFFTFColumbia Generating StationFinal Safety Analysis Report Hepner JunctionPine CreekpitpitSandpitEltopiaRanchWaterTankWater Tank1726026026261260Gravel pit17FiveCorners395395Hathaway800Pent884Watson1349Baumann Farm1600Othello1145Basin City770170RanchSavageIslandBasin CityRanchRanchLower Monumental DamPleasantViewFarmFIELDS GULCHAyerRanchPALOUSE FALLSRECREATION AREAFarmHarderDUNNIGAN COULEEDavinSkookumCan261Grain ElevatorGrain ElevatorOld RR gradeConnellConnell City925Grain ElevatorWASHTUCNA COULEERattlesnakeCanCOULEEHARDESTYMichigan PrairieWashtucnaKahlotusSAND HILLS COULEEHattonHATTON COULEEENEER A T T L E S N A K E F L A TCunningham CanyonPROVIDENCE COULEEPipelineGrain ElevatorCunninghamFrischnechtShanoBruceBURLINGTONNORTHERNRadioTowerRadio TowerMesaDevils CanyonSMITH CANYONOLD MAID COULEEWaterTankSITEOthelloAir Force StaCactusOthelloELECTRIFIEDTauntonSaddle GapPotholesEastCanalUS Government RRRanchBURLINGTON NORTHERNUNION PACIFICLower Monumental813FarringtonpitScottMagallonMathewsCornerRINGOLD FLATFisher Ranch152110 MI20 MI30 MI40 MI50 MI260RattlesnakeLakeCampLakeScooteneyReservoirT LakeWASHTUCNA COULEEClarkPondLake KahlotusSulfur LakeP A R A D I S E F L A T SLowCanalEagleLakesDry LakeESEPrescottHarshaLamarEuricaGrain elevatorGrain elevatorElwoodClydeGrainelevatorHatchGrainelevatorGrainelevatorGrain elevatorGrainelevatorGrainelevatorGrain elevatorGrainelevatorHadleyWalkerPageValleyGroveEnnisGrainelevatorGrain elevatorGrainelevatorWhitman StationSubstaSubstaCollegePlaceWALLA WALLALowdenTouchetMartinSlaterPipeline12395ZangerJunctionReeseClimaxSidingGrain elevatorSURVIVAL TRAINING AREAJUNIPER FORESTWaterTankGravelpitGravelpitReddLeveyWaterTankGrain elevatorGrain elevatorJOHNSONBUTTEThe ButteRadioTowerRadioTowerWallulaWaterTankHumoristMCNARY NATIONALWILDLIFE REFUGENine Mile CanyonCompressorStation540Snake River12QuarryWalker CanyonRYE GRASS FLATEELUOC SSARG EYRWaterTankQuarry124Lake SacajaweaGravelpitGladePascoSubstaSubstaIce Harbor DamJACKASSMOUNTAINWaterTankWooded IslandTaylor FlatESQUATZEL COULEEDiversionChannelEsquatzelRichlandPasco WestVista521ColumbiaPointTri-CitiesAirport407Potholes CanalWTPipelineDry HollowE U R E K A F L A TWinnett CanyonWinnett CanyonBadger HollowBadger HollowGravelpitBURLINGTON NORTHERNBURLINGTON NORTHERNSPRING VALLEYWebber CanyonWoodward CanyonBurbankFinleyNine Canyon395SacajaweaState ParkWTSNAKE RIVERL A K E W A L L U L AUNION PACIFICUNION PACIFICHedgesWTSubstaGrain elevatorGravelpitRadio TowersRadioTowerGrain elevatorWilliams WellsAmon WellYoungWellsCoyoteSpring14Bowden SpringsBofer CanyonTaylor CanyonFour CanyonStraub CanyonVistaCressWellsColumbia CanalKENNEWICKFranklin Co Irr Can NORTHERNBURLINGTON NORTHERNColumbia CanalBADGER MOUNTAINCanalSwitzler CanyonPipelineHORSE HEAVEN HILLSDry CreekWalla Walla RiverWHITMANMISSIONNHSWalla Walla RiverIslandViewRichland391124260McNary DamL A K E W A L L U L AWASHINGTONOREGONSESGardenaWindmillBig WellCold SpringsReservoirHunt DitchGreasewood CreekPine Dry CrBurlingame DitchTo Pendleton3957307303084Umatilla River20732SSEMilton-FreewaterWalla Walla ValleyUmapineWalla Walla RiverSkyranch 850Page 850204WestonAthena1111Grain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorWTWTBowlusHillGrain elevatorOregon Sky Ranch357Grain elevatorHoldmanWTNORTH FORK JUNIPER CANYONNORTH FORK COLD SPRINGS CANYONSOUTH FORK JUNIPER CANYONMIDDLE FORK COLD SPRINGS CANYONSOUTH FORK COLD SPRINGS CANYONCOLD SPRINGS CANYONDESPAIN GULCHSTAGE GULCHJUNIPER CANYONRUSH CANYONSwitzler CanyonTankBURLINGTON NORTHERNWARM SPRINGS CANYONVANSYCLE CANYONGrain elevator37FOURMILE GAPEchoHAT ROCKSTATE PARKUMATILLA BUTTEHermiston StateStanfieldHinkleSILLUSI BUTTEHERMISTON BUTTEHermistonMcNaryPower CitySubstationHERMISTON BUTTEUNION PACIFIC207COLD SPRINGSNWR84221SSW1414BOARDMANBOMBINGRANGE730LAKE UMATILLAUMATILLA NATIONAL WILDLIFE REFUGECOLUMBIA RIVERHepner JunctionGOLGOTHA BUTTE84CANOE RIDGEALDER RIDGEALDER RIDGEWindmillWindmillBoardman390PATERSONDEAD CANYONTULE CANYONRattlesnakeSpringRanchRanchOrdnanceWater towerUmatilla Army DepotRIDGEUMATILLA ORDNANCEDEPOTWestlandWest Extension Irrigation CanalDisposal PlantIrrigonUNION PACIFICWaterTowerBURLINGTONPatersonFOURMILE CANYONWARDBUTTEFINLEY BUTTESBING CANYONEast BranchGlade CreekCOYOTE COULEEBoardmanCoyote CanyonSAND RIDGEWindmillRanchWindmillRanchCemeteryClevelandBickletonCemeterySTEGEMAN CANYONSWBIG HORN CANYONWOOD GULCHDOUTY CANYONAlder CreekPine CreekSPRING CANYONCrowButte221Grain elevatorGrain elevatorGrain elevatorGravelpit2402242412232222RanchH O R S E H E A V E N H I L L SCemRanchGrain elevatorRanchGrain elevatorRanchRadioTowerGravelpitGravelpitRanchGrain elevatorCarter CanyonGrain elevGrain elevatorGrain elevatorGrain elevatorGrain elevatorRanchBadger CanyonBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksKelly GulchHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandIowa FlatsRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONGibbonWhitstrandChandler ButteSunnyside CanalChaffeePumpingStationRanchRanchRoza CanalYAKIMA RIVERUNION PACIFICHORSE HEAVEN HILLSProsser694GRANDVIEW BUTTEPumpingStationSunnyside764LichtySunnysideBryonRanchPumping StationPumping StationToppenishBuenaOutlookEmeraldGrangerGiffen LakeTOPPENISHNWRWSWYakima I R HdqrsNORTHERNBURLINGTONGranger Farm Labor CampPumpingStationTOPPENISH NWRSNIPES MOUNTAINBURLINGTONHEMBRE MTNSatusMabtonWTCemPumping StationSulfur SpringWaterTanksRadioTowerLibertyOleys LakeGrangeMabton West CanalYakimaIndian ReservationGrain elevatorBluelightWindmillGrain elevatorRadio StationRadio TowerMoore CanyonCoyote CanyonGravelpitProsserpit9797LozierSpringsCampbellSpringMaidenSpringSpringWebber CanyonMabton SiphonToppenish CreekToppenish CreekWapity SloughSatus No. 2 Pump CanalSunnyside CanalZillahRoza CanalSulfur CrBlack CanyonSpring CrSnipes CreekWater410PipelineEast Branch Glade CrMcKinleySpringGlade CreekGlade CreekWNWW242424324RanchRanchRange CentralCemObservation postBadger GapSquaw TitFiring Center AAFY A K I M A R I D G EU M T A N U M R I D G EY A K I M AF I R I N GC E N T E RSADDLE MOUNTAINSSADDLE MOUNTAINSCORRAL CANYONSOURDOUGH CANYONALKALI CANYONSADDLE MOUNTAINSNWNNEW A H L U K E S L O P ERanchPriest RapidsDamMattawaChristensen Bros840SMYRNA BENCHCNWRCNWRCNWRBeverlyRanchWAHATISPEAKMattawa750Desert570CorfuRanchROYAL SLOPEWaterTankCNWRCNWRCNWRSchwanaWhite BluffsSADDLE MOUNTAINNATIONAL WILDLIFE REFUGECABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsLower Crab CreekWTCNWRCold CreekHanford DitchTowersRanchRanchWaterTankCOLD CREEK VALLEYBensonSpringLockeIslandDry CrHorsethief PtCairn Hope PeakEmerson NippleSubstaH A N F O R D R E S E R V A T I O NWapatoSawyerDonaldPumping stationELEPHANT MOUNTAINHILLSZILLAH PEAKMOXEE VALLEYMoxee CityRATTLESNAKE HILLSRanchTowerPlantQuarantineStationBLACK ROCK VALLEYRanchRanchCemHigh TopR A T T L E S N A K E H I L L SR A T T L E S N A K E H I L L SRadioFacilityKITTITAS CANYONMoxee CanalMoxee CanalSelah CreekHanson CreekMcDonald SpringsCottonwood CreekBlack Rock SpringSentinel GapSentinel BluffsELECTRIFIEDSmyrnaSENTINEL MOUNTAINCemPriest RapidsLakeNNWSAND DUNESWHISKEY DICKMTNROCKY COULEESPRING GULCHCaribou CreekRYEGRASS COULEE PARKMIDDLE CANYONHULT BUTTEJOHNSON CANYONBOYLSTON MOUNTAINSRock SpringPoison SpringLone Star SpringRYEGRASSMOUNTAINWippe Pumping StationBadger CrFire stationKittitas Microwave TowerSCHNEBLY COULEEF R E N C H M A N H I L L SWinchester WastewayMoses Lake Sky Ranch1100GeorgeSAND HILLSPotholesState ParkTHE POTHOLES10Mae10Ranch909026CNWRChristensen1150F R E N C H M A N H I L L SCemCampRoyalCityNATURAL CORRALLARSON AFBIMPACT AREARed RockCouleeCNWRWest CanalFrenchman Hills LakeRoyal LakeWanapum DamCNWRFrenchman SpringsPOTHOLES COULEEBABCOCK BENCHLAVAGINKGOPETRIFIEDFOREST PARKSand HollowBABCOCK RIDGEStan CoffinLakeCRESCENT BARCRESCENT BAR281283Leslie CreekSkookumchuck CreekJohnson CrBoylstonBADGER POCKETEast KittitasAirway BeaconTrail CreekNorth Branch CanalBeaconHIAWATHA VALLEYSAND DUNES17171090Larson Air Force Base1186Moses LakePOTHOLES RESERVOIRMoses Lake12002121261261RitzvilleRitzville180021395NNELindDewald1880WardenWaterFranz RanchSchrag StationLaingStationRefineryWheelerRaugust StationWindmillLIND COULEERadioTowerDryland ExperimentProvidenceGrain elevatorsGrain elevatorsLind1491ServiaLIND COULEEBOWERS COULEELIND COULEEPipelineNew Warden1265GrainelevatorGravel pitPipelineNORTHERN PACIFICUndergroundaqueductCHICAGO MILWAUKEE ST PAUL AND PACIFICFARRIER COULEEWindmillWindmillPAHA COULEEPahaNORTHERN PACIFIC1090RalstonMcElroy LakePizarroGrainelevROCKY COULEEUndergroundaqueductLewis HornPelican HornLIND COULEEBassett JunctionMcDonald SidingWindmillTiflisRitellSidingNORTHERN PACIFICCHICAGO MILWAUKEE ST PAUL AND PACIFICRocky Coulee WastewayO'Sullivan DamSielen SidingUpper GooseLakeJACKASSMOUNTAINParkerHornSoda LakeCOLUMBIANATIONALWILDLIFE REFUGEGoose LakeShiner LakeMorgan LakeTaggars1149Kent Farms1155BeatriceGravel pitRoxboroWEBER COULEEMeterStationHillcrestRuffKITTITAS CO GRANT COADAMS COBENTON COFRANKLIN COYAKIMA COKLICKITAT COWALLA WALLA COUMATILLA COMORROW CO82Plymouth8212828212CemGrandviewDamNorthProsser82BURLINGTON121282KionaGravelpit18218212ChandlerIslandViewSacajaweaState ParkSixprong CreekSudburyRoute 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonwoodIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.46°00'46°30'46°45'46°15'45°45'47°00'LongitudeLatitude46°00'46°30'46°45'46°15'47°00'LatitudeLongitude119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'123953953953953030General Area, 0 - 50 Miles990306.602.1-2Form No. 960690Amendment 55May 2001FigureDraw. No.Rev.60 Miles50 MilesPendleton149337Grain elevatorSTAGE GULCHMISSOURI GULCHRailroadPipelinePowerlineMedium Duty RoadLight Duty RoadHeavy Duty RoadLEGEND395260Landplane AirportLanding AreaFederal Route MarkerState RouteInterstate Route80NPark or ReservationBoundarySandpit or GravelpitPopulated PlacesRadio Tower, WellLatitude/Longitude930114.50 MiAug 1998SCALE20 Statute Miles151050530 Kilometers2515105052045°45'Brushy CreekColumbia Generating Station50 Mile Ingestion ExposureEmergency Planning ZoneNColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Project Area Map - 10 Mile Radius4-1.201.603099FigureForm No. 960690.veR.oN .warDEltopiaRanchWaterTankBasin City770170RanchSavageIslandBasin CityRanchRanchUS Government RRMathewsCornerRINGOLD FLATCampLakeClarkPondRadioTowerGravelpitGladePascoJACKASSMOUNTAINWaterTankWooded IslandESQUATZEL COULEEDiversionChannelEsquatzelRichlandPasco WestVista521ColumbiaPointTri-CitiesAirport407Potholes CanalWT395SacajaweaState ParkWTSubsta14VistaKENNEWICKFranklin Co Irr Can NORTHERNColumbia CanalBADGER MOUNTAINIslandViewRichland391Grain elevator240224Grain elevatorGrain elevatorBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONChandler ButteChaffeeRoza CanalWebber CanyonWhite BluffsCABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsHanford DitchTowersBENTON CO82121282KionaGravelpit18218212ChandlerIslandViewSacajaweaState ParkRoute 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.StevensCountryChristianCountry HavenEdwin MarkumBig RiverCOLD CREEK VALLEYH A N F O R D R E S E R V A T I O NYAKIMA RIVERIowa FlatsN Power Plant LoopColumbia Generating StationKinder-CareKiBewoodScale in Miles105055 MILES20 MILESFFTFCanal10 MILESColumbia Generating StationFinal Safety Analysis Report Hepner JunctionPine CreekpitpitSandpitEltopiaRanchWaterTankWater Tank1726026026261260Gravel pit17FiveCorners395395Hathaway800Pent884Watson1349Baumann Farm1600Othello1145Basin City770170RanchSavageIslandBasin CityRanchRanchLower Monumental DamPleasantViewFarmFIELDS GULCHAyerRanchPALOUSE FALLSRECREATION AREAFarmHarderDUNNIGAN COULEEDavinSkookumCan261Grain ElevatorGrain ElevatorOld RR gradeConnellConnell City925Grain ElevatorWASHTUCNA COULEERattlesnakeCanCOULEEHARDESTYMichigan PrairieWashtucnaKahlotusSAND HILLS COULEEHattonHATTON COULEEENEER A T T L E S N A K E F L A TCunningham CanyonPROVIDENCE COULEEPipelineGrain ElevatorCunninghamFrischnechtShanoBruceBURLINGTONNORTHERNRadioTowerRadio TowerMesaDevils CanyonSMITH CANYONOLD MAID COULEEWaterTankOthelloAir Force StaCactusOthelloELECTRIFIEDTauntonSaddle GapPotholesEastCanalUS Government RRRanchBURLINGTON NORTHERNUNION PACIFICLower Monumental813FarringtonpitScottMagallonMathewsCornerRINGOLD FLATFisher Ranch152110 MI20 MI30 MI40 MI50 MI260RattlesnakeLakeCampLakeScooteneyReservoirT LakeWASHTUCNA COULEEClarkPondLake KahlotusSulfur LakeP A R A D I S E F L A T SLowCanalEagleLakesDry LakeESEPrescottHarshaLamarEuricaGrain elevatorGrain elevatorElwoodClydeGrainelevatorHatchGrainelevatorGrainelevatorGrain elevatorGrainelevatorGrainelevatorGrain elevatorGrainelevatorHadleyWalkerPageValleyGroveEnnisGrainelevatorGrain elevatorGrainelevatorWhitman StationSubstaSubstaCollegePlaceWALLA WALLALowdenTouchetMartinSlaterPipeline12395ZangerJunctionReeseClimaxSidingGrain elevatorSURVIVAL TRAINING AREAJUNIPER FORESTWaterTankGravelpitGravelpitReddLeveyWaterTankGrain elevatorGrain elevatorJOHNSONBUTTEThe ButteRadioTowerRadioTowerWallulaWaterTankHumoristMCNARY NATIONALWILDLIFE REFUGENine Mile CanyonCompressorStation540Snake River12QuarryWalker CanyonRYE GRASS FLATEELUOC SSARG EYRWaterTankQuarry124Lake SacajaweaGravelpitGladePascoSubstaSubstaIce Harbor DamJACKASSMOUNTAINWaterTankWooded IslandTaylor FlatESQUATZEL COULEEDiversionChannelEsquatzelRichlandPasco WestVista521ColumbiaPointTri-CitiesAirport407Potholes CanalWTPipelineDry HollowE U R E K A F L A TWinnett CanyonWinnett CanyonBadger HollowBadger HollowGravelpitBURLINGTON NORTHERNBURLINGTON NORTHERNSPRING VALLEYWebber CanyonWoodward CanyonBurbankFinleyNine Canyon395SacajaweaState ParkWTSNAKE RIVERL A K E W A L L U L AUNION PACIFICUNION PACIFICHedgesWTSubstaGrain elevatorGravelpitRadio TowersRadioTowerGrain elevatorWilliams WellsAmon WellYoungWellsCoyoteSpring14Bowden SpringsBofer CanyonTaylor CanyonFour CanyonStraub CanyonVistaCressWellsColumbia CanalKENNEWICKFranklin Co Irr Can NORTHERNBURLINGTON NORTHERNColumbia CanalBADGER MOUNTAINCanalSwitzler CanyonPipelineHORSE HEAVEN HILLSDry CreekWalla Walla RiverWHITMANMISSIONNHSWalla Walla RiverIslandViewRichland391124260McNary DamL A K E W A L L U L AWASHINGTONOREGONSESGardenaWindmillBig WellCold SpringsReservoirHunt DitchGreasewood CreekPine Dry CrBurlingame DitchTo Pendleton395730730Pendleton14933084Umatilla River20732SSE37Milton-FreewaterWalla Walla ValleyUmapineWalla Walla RiverSkyranch 850Page 850204WestonAthena1111Grain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorWTWTBowlusHillGrain elevatorOregon Sky Ranch357Grain elevatorHoldmanWTNORTH FORK JUNIPER CANYONNORTH FORK COLD SPRINGS CANYONSOUTH FORK JUNIPER CANYONMIDDLE FORK COLD SPRINGS CANYONSOUTH FORK COLD SPRINGS CANYONCOLD SPRINGS CANYONDESPAIN GULCHSTAGE GULCHJUNIPER CANYONRUSH CANYONSwitzler CanyonTankBURLINGTON NORTHERNWARM SPRINGS CANYONVANSYCLE CANYONSTAGE GULCHMISSOURI GULCHGrain elevator37FOURMILE GAPEchoHAT ROCKSTATE PARKUMATILLA BUTTEHermiston StateStanfieldHinkleSILLUSI BUTTEHERMISTON BUTTEHermistonMcNaryPower CitySubstationHERMISTON BUTTEUNION PACIFIC207COLD SPRINGSNWR84221SSW1414BOARDMANBOMBINGRANGE730SCALE20 Statute Miles151050530 Kilometers25151050520LAKE UMATILLAUMATILLA NATIONAL WILDLIFE REFUGECOLUMBIA RIVERHepner JunctionGOLGOTHA BUTTE84CANOE RIDGEALDER RIDGEALDER RIDGEWindmillWindmillBoardman390PATERSONDEAD CANYONTULE CANYONRattlesnakeSpringRanchRanchOrdnanceWater towerUmatilla Army DepotRIDGEUMATILLA ORDNANCEDEPOTWestlandWest Extension Irrigation CanalDisposal PlantIrrigonUNION PACIFICWaterTowerBURLINGTONPatersonFOURMILE CANYONWARDBUTTEFINLEY BUTTESBING CANYONEast BranchGlade CreekCOYOTE COULEEBoardmanCoyote CanyonSAND RIDGEWindmillRanchWindmillRanchCemeteryClevelandBickletonCemeterySTEGEMAN CANYONSWBIG HORN CANYONWOOD GULCHDOUTY CANYONAlder CreekPine CreekSPRING CANYONCrowButte221Grain elevatorGrain elevatorGrain elevatorGravelpit2402242412232222RanchH O R S E H E A V E N H I L L SCemRanchGrain elevatorRanchGrain elevatorRanchRadioTowerGravelpitGravelpitRanchGrain elevatorCarter CanyonGrain elevGrain elevatorGrain elevatorGrain elevatorGrain elevatorRanchBadger CanyonBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksKelly GulchHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandIowa FlatsRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONGibbonWhitstrandChandler ButteSunnyside CanalChaffeePumpingStationRanchRanchRoza CanalYAKIMA RIVERUNION PACIFICHORSE HEAVEN HILLSProsser694GRANDVIEW BUTTEPumpingStationSunnyside764LichtySunnysideBryonRanchPumping StationPumping StationToppenishBuenaOutlookEmeraldGrangerGiffen LakeTOPPENISHNWRWSWYakima I R HdqrsNORTHERNBURLINGTONGranger Farm Labor CampPumpingStationTOPPENISH NWRSNIPES MOUNTAINBURLINGTONHEMBRE MTNSatusMabtonWTCemPumping StationSulfur SpringWaterTanksRadioTowerLibertyOleys LakeGrangeMabton West CanalYakimaIndian ReservationGrain elevatorBluelightWindmillGrain elevatorRadio StationRadio TowerMoore CanyonCoyote CanyonGravelpitProsserpit9797LozierSpringsCampbellSpringMaidenSpringSpringWebber CanyonMabton SiphonToppenish CreekToppenish CreekWapity SloughSatus No. 2 Pump CanalSunnyside CanalZillahRoza CanalSulfur CrBlack CanyonSpring CrSnipes CreekWater410PipelineEast Branch Glade CrMcKinleySpringGlade CreekGlade CreekWNWW242424324RanchRanchRange CentralCemObservation postBadger GapSquaw TitFiring Center AAFY A K I M A R I D G EU M T A N U M R I D G EY A K I M AF I R I N GC E N T E RSADDLE MOUNTAINSSADDLE MOUNTAINSCORRAL CANYONSOURDOUGH CANYONALKALI CANYONSADDLE MOUNTAINSNWNNEW A H L U K E S L O P ERanchPriest RapidsDamMattawaChristensen Bros840SMYRNA BENCHCNWRCNWRCNWRBeverlyRanchWAHATISPEAKMattawa750Desert570CorfuRanchROYAL SLOPEWaterTankCNWRCNWRCNWRSchwanaWhite BluffsSADDLE MOUNTAINNATIONAL WILDLIFE REFUGECABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsLower Crab CreekWTCNWRCold CreekHanford DitchTowersRanchRanchWaterTankCOLD CREEK VALLEYBensonSpringLockeIslandDry CrHorsethief PtCairn Hope PeakEmerson NippleSubstaH A N F O R D R E S E R V A T I O NWapatoSawyerDonaldPumping stationELEPHANT MOUNTAINHILLSZILLAH PEAKMOXEE VALLEYMoxee CityRATTLESNAKE HILLSRanchTowerPlantQuarantineStationBLACK ROCK VALLEYRanchRanchCemHigh TopR A T T L E S N A K E H I L L SR A T T L E S N A K E H I L L SRadioFacilityKITTITAS CANYONMoxee CanalMoxee CanalSelah CreekHanson CreekMcDonald SpringsCottonwood CreekBlack Rock SpringSentinel GapSentinel BluffsELECTRIFIEDSmyrnaSENTINEL MOUNTAINCemPriest RapidsLakeNNWSAND DUNESWHISKEY DICKMTNROCKY COULEESPRING GULCHCaribou CreekRYEGRASS COULEE PARKMIDDLE CANYONHULT BUTTEJOHNSON CANYONBOYLSTON MOUNTAINSRock SpringPoison SpringLone Star SpringRYEGRASSMOUNTAINWippe Pumping StationBadger CrFire stationKittitas Microwave TowerSCHNEBLY COULEEF R E N C H M A N H I L L SWinchester WastewayMoses Lake Sky Ranch1100GeorgeSAND HILLSPotholesState ParkTHE POTHOLES10Mae10Ranch909026CNWRChristensen1150F R E N C H M A N H I L L SCemCampRoyalCityNATURAL CORRALLARSON AFBIMPACT AREARed RockCouleeCNWRWest CanalFrenchman Hills LakeRoyal LakeWanapum DamCNWRFrenchman SpringsPOTHOLES COULEEBABCOCK BENCHLAVAGINKGOPETRIFIEDFOREST PARKSand HollowBABCOCK RIDGEStan CoffinLakeCRESCENT BARCRESCENT BAR281283Brushy CreekLeslie CreekSkookumchuck CreekJohnson CrBoylstonBADGER POCKETEast KittitasAirway BeaconTrail CreekNorth Branch CanalBeaconHIAWATHA VALLEYSAND DUNES17171090Larson Air Force Base1186Moses LakePOTHOLES RESERVOIRMoses Lake12002121261261RitzvilleRitzville180021395NNELindDewald1880WardenWaterFranz RanchSchrag StationLaingStationRefineryWheelerRaugust StationWindmillLIND COULEERadioTowerDryland ExperimentProvidenceGrain elevatorsGrain elevatorsLind1491ServiaLIND COULEEBOWERS COULEELIND COULEEPipelineNew Warden1265GrainelevatorGravel pitPipelineNORTHERN PACIFICUndergroundaqueductCHICAGO MILWAUKEE ST PAUL AND PACIFICFARRIER COULEEWindmillWindmillPAHA COULEEPahaNORTHERN PACIFIC1090RalstonMcElroy LakePizarroGrainelevROCKY COULEEUndergroundaqueductLewis HornPelican HornLIND COULEEBassett JunctionMcDonald SidingWindmillTiflisRitellSidingNORTHERN PACIFICCHICAGO MILWAUKEE ST PAUL AND PACIFICRocky Coulee WastewayO'Sullivan DamSielen SidingUpper GooseLakeJACKASSMOUNTAINParkerHornSoda LakeCOLUMBIANATIONALWILDLIFE REFUGEGoose LakeShiner LakeMorgan LakeTaggars1149Kent Farms1155BeatriceGravel pitRoxboroWEBER COULEEMeterStationHillcrestRuffKITTITAS CO GRANT COADAMS COBENTON COFRANKLIN COYAKIMA COKLICKITAT COWALLA WALLA COUMATILLA COMORROW CORailroadPipelinePowerlineMedium Duty RoadLight Duty RoadHeavy Duty RoadLEGEND395260Landplane AirportLanding AreaFederal Route MarkerState RouteInterstate Route80NPark or ReservationBoundarySandpit or GravelpitPopulated PlacesRadio Tower, WellLatitude/Longitude82Plymouth8212828212CemGrandviewDamNorthProsser82BURLINGTON121282KionaGravelpit18218212ChandlerColumbia Generating Station50 Mile Ingestion ExposureEmergency Planning ZoneNIslandViewSacajaweaState ParkSixprong CreekSudbury930114.50 MiAug 1998Route 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonwoodIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.46°00'46°30'46°45'46°15'45°45'47°00'LongitudeLatitude46°00'46°30'46°45'46°15'45°45'47°00'LatitudeLongitude119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'123953953953953030Project Area Map - 50 Mile Radius990306.502.1-5Form No. 960690Amendment 55May 2001FigureDraw. No.Rev.ColumbiaGeneratingStationColumbia Generating StationFinal Safety Analysis Report 2010 Population in Communities Around Site970187.1412.1-6FigureAmendment 63December 2015Form No. 960690Draw. No.Rev.Ephrata(7,664)Quincy (6,750)Royal City (2,140)Moses Lake (20,366)Odessa (910)Ritzville (1,673)Lind (564)Mesa (489)Connell (4,209)Kahlotus (193)Dayton (2,526)Prescott (318)Waitsburg (1,217)Walla Walla (31,731)College Place (8,765)Milton Freewater (7,050)Stanfield (2,043)Boardman(3,220)Hermiston (16,745)Union Gap (6,047)Wapato (4,997)Toppenish (8,949)Granger (3,246)Yakima (91,196)Moxee (3,308)Zillah (2,964)Mabton(2,286)Prosser (5,714)Benton City (3,038)Columbia Generating StationIrrigon(1,826)Umatilla(6,906)Pendleton (16,612)Scale01020304050 MilesColumbia RiverYakima RiverSnake RiverColumbia RiverEllensburg (18,174)MorrowKlickitatYakimaKittitasGrantAdamsFranklinWalla WallaUmatillaBentonRichland (48,058)West Richland (11,811)Kennewick (73,917)George (501)Selah (7,147)Mattawa (4,437)Othello (7,364)Warden (2,692)Sunnyside (15,858)Grandview10,862)Columbia Generating StationFinal Safety Analysis ReportLDCN-14-009, 13-067Pasco (59,781)

COLUMBIA GENERATING STATION Amendment 60 FINAL SAFETY ANALYSIS REPORT December 2009 LDCN-08-035 2.2-1 2.2 NEARBY INDUSTRIAL, TRANSPORTATION, AND MILITARY FACILITIES This section describes the industrial, transportation, and military installations and operations in the vicinity of the site which may have a potential effect on the safe operation of Columbia Generating Station (CGS).

2.2.1 LOCATION AND ROUTES

There are no military bases, missile sites, manufacturing plants, chemical plants, commercial chemical storage facilities, or airports within a 5-mile radius of the site. A security barrier completely surrounds the station and its major supporting facilities to keep unauthorized vehicles a safe distance from critical structures.

According to the Richland Operations Office of the Department of Energy (DOE) (Reference 2.2-1), there are no plans for petrochemical storage facilities, airports, oil and gas pipelines, or petrochemical tank farms on the Hanford Site. Plans for modifications to or new radiological material treatment or storage facilities are discussed in Section 2.2.2.

As shown in Figure 2.1-3, the following facilities are located at or near the CGS site: Energy Northwest Plant Engineering Center, H. J. Ashe Substation, DOE Fast Flux Test Facility (FFTF), WNP-1 and WNP-4 sites, DOE 618-11 (Wye) radioactive waste burial ground, Permanent meteorological tower, Independent Spent Fuel Storage Installation (ISFSI), and Hydrogen Storage and Supply Facility. Other facilities that are located within a 5-mile radius of the site include: The Plant Support Facility/Emergency Operation Facility which is located 0.75 miles southwest of CGS on Energy Northwest property, The Benton Substation which is located 3 miles east-southeast of CGS on DOE property, The Laser Interferometer Gravitational-Wave Observatory (LIGO) which is located approximately 3.3 miles west-southwest of CGS on DOE property, and The DOE 618-10 (300 North) radioactive waste burial ground which is located approximately 3.5 miles south of CGS on DOE property.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-01-055,03-023 2.2-2 Transportation needs of CGS can be met by existing barge, rail, and highway facilities. Barges of up to 3000 tons capacity can be accommodated on the Columbia River within the Hanford Site. A barge unloading facility 9 miles south of the plant was used for delivery of large construction items for the DOE FFTF and Energy Northwest nuclear projects. These materials were transported by truck or rail to the construction sites from the Port of Benton landing.

The CGS site is serviced by a two-lane paved access road connected to Hanford Site Route 4, which is a paved four-lane major artery located 1.6 miles west of the station. Route 4 is part of the DOE road system. The DOE-owned road system connects the areas of the Hanford Site with paved two-lane and four-lane primary roads, secondary gravel roads, and unimproved roads. State Highway 240 traverses the Hanford Site from the southeast to the northwest. The highway passes within about 7 miles of CGS in the southwest quadrant. The highway connects into State Highway 24, which goes west to Yakima, Washington, and across the Vernita Bridge on the Columbia River 22 miles to the northwest (see Figure 2.2-1).

The Hanford Site (DOE) railroad system (see Figure 2.2-2) connects with commercial rail systems in Richland and Kennewick, Washington. Railroad operations that pass through CGS property are restricted to only those trains that have been authorized by Energy Northwest Security. The rail line is physically blocked at the two points where the plant vehicle barrier crosses the tracks.

Heavy barge traffic north of the Port of Benton dock is not feasible because the river channel is too shallow and the current is too swift. The environmental impact and economic cost of constructing a new barge slip at some upstream location and channeling the river cannot presently be justified with the availability of land transportation between the Port of Benton facility and the Hanford Site.

Making the Columbia River navigable for barges from north of Richland to Wenatchee would result in barge traffic past the CGS site at River Mile 352. However, this situation would not likely occur. Locks or other lift facilities would have to be constructed at the Priest Rapids, Wanapum, and Rock Island Dams. Furthermore, in 2000, a presidential executive order created the Hanford Reach National Monument, protecting the 51-mile Hanford Reach of the Columbia River (Reference 2.2-2). The protected area includes a 1/4-mile-wide corridor on the west side of the river in the vicinity of CGS.

Airports, military facilities, low-level Federal airways, and airport instrument approaches in the vicinity of CGS are discussed in Section 3.5.1.6 and shown in Figure 2.2-3.

An explosives and ordinance test site operated by Pacific Northwest National Laboratory approximately 13 miles northwest of the site was abandoned in mid-1975 (Reference 2.2-3). Explosives for operations such as quarrying or seismic studies on the Hanford Site are brought to the blasting site as needed and unused quantities are removed. Normally the only explosives COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 LDCN-05-011 2.2-3 stored on the Hanford Site are small arms ammunition for use by the security patrols. A small arms firing range used for training by the DOE security patrol is located 8 miles due south of the plant (Reference 2.2-3). Another range, used by Energy Northwest security personnel, is located 1.5 miles east-northeast of CGS on Energy Northwest lease property.

2.2.2 DESCRIPTIONS

2.2.2.1 Description of Facilities Energy Northwest's Plant Engineering Center is located west of the CGS turbine generator building as shown in Figure 1.2-1. It is a two-story, 100,000 ft2 facility designed to house approximately 470 CGS plant staff personnel. The H. J. Ashe Substation is located approximately 0.5 mile north of CGS and is operated by the Bonneville Power Administration as part of its transmission system.

The Energy Northwest permanent meteorological tower is located less than 0.5 mile west of the plant site. The tower is automated so that the only personnel at the tower are those required to make adjustments to the instruments or to perform repairs to the system. There are no permanent personnel at the facility.

The ISFSI is located immediately north-northwest of the plant. Confinement of all radioactive materials at the ISFSI is provided by the required use of NRC certified spent fuel storage casks listed in 10 CFR 72.214. The ISFSI storage cask system consists of an inner stainless steel multi-purpose canister (MPC) and an outer storage overpack. The MPC contains the spent fuel. It is a welded pressure vessel with no bolted closure or mechanical seals. Primary closure welds are examined and leakage tested to ensure their integrity. The MPC redundant closures are designed to maintain confinement integrity during normal conditions of storage, and off-normal and postulated accident conditions. The outer storage overpack is fabricated from concrete and structural steel components that are classified as important to safety. A fully loaded spent fuel storage cask weighs approximately 185 tons. The spent fuel loaded storage casks are located within the Energy Northwest ISFSI protected area which is surrounded by a fence and topped with barbed wire. The ISFSI access gates are locked except when in use.

The Hydrogen Storage and Supply Facility is located 0.6 miles south-southeast of the plant site. The facility is part of a hydrogen water chemistry system to prevent and mitigate intergranular stress corrosion cracking in reactor internal structures and piping welds. The facility consists of a fenced gravel yard with concrete pads constructed to accommodate a liquid hydrogen tank, nitrogen tank, gaseous hydrogen tubes, and all supporting piping and equipment necessary to supply CGS with gaseous hydrogen. The liquid and compressed gases are delivered to the facility by truck.

COLUMBIA GENERATING STATION Amendment 60 FINAL SAFETY ANALYSIS REPORT December 2009 LDCN-09-026 2.2-4 Within the exclusion area radius of 1950 m is Energy Northwest's 1250-MWe WNP-1 project. Construction of the PWR plant, located 1500 m (4925 ft) east-southeast of CGS, was suspended in April 1982. In May 1994 the Energy Northwest Board of Directors voted to terminate WNP-1. The construction of twin unit WNP-4, located 1250 m (4100 ft) east-northeast of CGS, was terminated in January 1982. These projects have a separate access road that ties into the Hanford Site Route 4, 1.6 miles south of the CGS access road. Support activities at either the WNP-1 or WNP-4 sites do not interfere with operation of CGS. These may include activities associated with site restoration and economic development (such as leasing of excess facilities for office space and manufacturing). Within the exclusion area, Energy Northwest has the authority to determine all activities within the meaning of 10 CFR 100.3(a), including the authority to remove all personnel and property from the area.

The Laser Interferometer Gravitational-Wave Observatory (LIGO) is located approximately 3.3 miles west-southwest from the plant site. The mission of this research facility is to observe gravitational waves of cosmic origin. The facility houses laser interferometers, consisting of mirrors suspended at each of the corners of an L-shaped vacuum system measuring 2.5 miles on a side. The materials and activities at this facility do not impact the operation of CGS.

The Umatilla Chemical Depot (UMCD), formerly known as Umatilla Army Depot, is located in northeastern Oregon in parts of Umatilla and Morrow Counties approximately 43 miles south of CGS. In 1962, the UMCD began storing chemical weapons and stored approximately 12% (3717 tons) of the nation's original chemical weapons. The weapons consisted of various munitions and ton containers containing GB (Sarin), VX, or HD (Mustard) agents. Beginning in 1990, the UMCD shipped all conventional ammunition and supplies to other installations and only chemical weapons remained pending disposal. The Umatilla Chemical Agent Disposal Facility was completed in 2001 and uses high temperature incineration to destroy the weapons. The Army began weapons disposal in 2004 and has destroyed all GB and VX nerve agent chemical weapons. In June, 2009, the Army began the HD blister agent disposal campaign which is expected to take between one and two years to complete. Upon completion, the facility will be dismantled and the UMCD will be closed.

As discussed in Section 2.1.1 and shown in Figure 2.1-1, CGS is located on the DOE Hanford Site. In reviewing the plant site and the vicinity for potential external hazards or hazardous material, the Hanford facilities currently operating, recently operating, or with the potential for operating were screened. The facilities discussed below are those believed to pose the most risk to the safe operations of CGS. The safety analysis reports and accident analysis prepared for those facilities were reviewed to determine possible hazards. No accidents evaluated present a physical challenge to the CGS buildings. Releases with the potential to impact the operation of CGS were radioactive particulate that would be effectively mitigated within General Design Criterion (GDC) 19 limits by the control room high-efficiency particulate air (HEPA) filters. Considered but not included were the 200 East Burial Grounds, the Critical Mass Laboratory, the Liquid Effluent Retention Facility, and the Effluent Treatment Facility in the 200 East Area. In the 200 West Area, the T Plant, U Plant, Reduction-Oxidation Plant, COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-11-027 2.2-5 and the 222-S Laboratory were considered but not included. These facilities have insufficient radiological or toxicological inventories in a dispersible form to represent a risk to CGS operation. The specific facilities included are discussed in Table 2.2-1.

Three DOE facilities are located within a 5-mile radius of the plant site. These are the Fast Flux Test Facility (FFTF) and two radioactive waste burial grounds. The specific hazards associated with these facilities are summarized in Table 2.2-1 and the specific activities are listed below:

The FFTF is a deactivated sodium cooled breeder reactor located approximately 3 miles southwest of CGS. All fuel has been removed and shipped to the Idaho National Laboratory. All sodium has been removed, solidified, and is stored on-site. The facility has been placed in a long-term, low-cost surveillance and maintenance condition. The 618-10 (300 North) Waste Burial Ground is approximately 3.5 miles south of CGS. DOE has initiated trench remediation activities at the site. Trench remediation is expected to take 18 months (1/2013).

The 618-11 (Wye) Waste Burial Ground is directly west of CGS, outside of Energy Northwest leased land, but within its 1950-meter exclusion area radius and security perimeter. The site received low- to high-activity waste, fission products, some plutonium-contaminated waste, and non-radiological hazardous waste from March 1962 to December 1967 from the Hanford 300 Area. The waste is buried in 3 trenches, 50 Vertical Pipe Units (VPUs), and four caissons. The site was covered with an overburden of soil when it was closed. The surface was stabilized in 1982 with an additional 2 ft of soil. Since surface stabilization, activities at the site have been limited to monitoring and surveillance. DOE completed non-intrusive surveillance and characterization activities at the site in 2011 to obtain data information and information for planning remediation activities.

The DOE 300, 200 East, and 200 West Areas are located within a 10-mile radius of the site. The current waste management activities (storage, disposal, and treatment) conducted in these areas are discussed in Table 2.2-1. The 300 Area is approximately 7 miles southeast of CGS. The only hazard presented to CGS from this site is from the spent nuclear fuel and other radioactive material stored there. There is an unknown quantity of miscellaneous reactor fuel material in the 300 Area. This quantity is not publicly available information.

The DOE 200 East and 200 West Areas are approximately 10 miles northwest of CGS. Originally these facilities were constructed to support the extraction of weapons grade plutonium for the defense program. However, as the Hanford mission has changed from production to environmental cleanup, so has the purpose of the facilities discussed. This COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-6 change in mission has, in some cases, resulted in a change in the hazards presented to CGS plant site and personnel.

A private (non-DOE) low-level radioactive waste disposal area is adjacent to 200 East Area. There are also plans to build private waste vitrification facilities adjacent to 200 East. These facilities are also discussed in Table 2.2-1.

Several plutonium production reactor facilities are located approximately 20 miles north-northwest of CGS. All of the reactors were water cooled, graphite moderated. The last operating reactor, the N Reactor, was permanently shut down in 1991. The N Reactor also provided steam for the Energy Northwest Hanford Generating Station until 1987. The fuel has been removed from the reactors for storage or treatment. The current activities at these reactor sites are also discussed in Table 2.2-1.

The nearest petroleum product storage tanks are located 22 miles southeast of the site: approximately 23 million gal capacity at the Chevron Pipeline Company and approximately 20 million gal capacity at the Tidewater Barge Lines.

2.2.2.2 Description of Products and Materials The existing Hanford Site railroad track (owned by the DOE and operated by a private contractor in support of the Hanford Operations), and the CGS, the WNP-1, WNP-4, and the FFTF railroad spurs all run within the exclusion area of the plant site. Shipments of large quantities of hazardous materials on this track that existed during initial licensing of CGS are no longer made (Reference 2.2-4).

The DOE has no plans for railroad shipments of explosives in the foreseeable future. However the DOE's Richland Operations Office has agreed to notify Energy Northwest prior to transporting any explosive shipments of more than 1800 lb past CGS (Reference 2.2-5). Energy Northwest will provide an analysis to the NRC of the potential consequences prior to the start of such shipping (Reference 2.2-6).

Hazardous material is also transported on Hanford Route 4 by DOE. Chlorine is the only material of concern transported on Route 4 with the potential for impacting CGS operation.

Section 6.4.4.2.1 provides additional information on control room habitability assessments for CGS.

The Yakima Training Center, a sub-installation of Fort Lewis, is 30 miles northwest of the site. The center consists of 327,000 acres. The center provides training facilities and logistical support and it is used for firing of all types of ordnance, both in a direct mode and by indirect artillery and mortars. Weapons to 155mm are fired. This type firing occurs frequently. Other types of live ordnance use at the center include aerial delivery by high performance aircraft of ordnance to include 2,000-lb bombs, helicopter weapons which include automatic weapons and COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-7 2.75-in. folding fin rockets, and anti-aircraft missiles. These latter activities are significant as to occurrence. The majority of the ordnance impacts a 20,000-acre area which is generally located in the central portion of the center. All activities are confined to the geographical limits of the center and/or its restricted air space unless special arrangements are made with affected agencies. Mechanized units (i.e., tanks and armored personnel carriers) from Fort Lewis and reserve components conduct extensive maneuvers on all accessible areas of the Training Center and use specially designed ranges to practice firing their weapons. Infantry and engineer units that support the mechanized units also train at the center. Training activity is greatest from March to November. War games sometimes involve troop and equipment deployment at the Richland Airport and along Highway 243 west of Vernita Bridge. Helicopters may fly near the Hanford Site, or military vehicles may travel over Highway 240 (Reference 2.2-7).

2.2.2.3 Pipelines There are no commercial oil or gas pipelines in the vicinity of CGS. The nearest major natural gas transmission pipeline to the site is about 12 miles. A 20-in. gas transmission line of the Northwest Pipeline Corporation is located east and essentially parallel to U.S. Highway 395 between Pasco and Ritzville, Washington. A second pipeline system consisting of parallel 36-in. and 42-in. lines, owned by Pacific Gas Transmission Company, passes through Wallula, approximately 24 miles from the site (Reference 2.2-8). These distances eliminate any potential hazard to plant operations due to a natural gas fire or explosion. The Energy Northwest Hydrogen Storage and Supply Facility is located 0.6 miles south-southeast of the plant and is connected to the plant with a 2-in NPS gas pipeline. The pipeline runs north from the facility approximately 400 ft east of the plant and then turns and runs west approximately 400 feet north of the plant then south approximately 200 ft west of the plant to its connection point on the west side of the Turbine Building. Fire and explosion risks to the plant involving this pipeline are discussed in Appendix F and Section 3.5.1.5.

2.2.2.4 Waterways Makeup water inlet structures are located in the Columbia River 315 ft from the shoreline at low river flow (36,000 cfs; el. 341.73 ft) at river mile 351.75.

A significant amount of Columbia River barge traffic moves as far upstream as the Ports of Pasco and Kennewick. Also, a docking facility established by the Port of Benton in North Richland (approximately 9 miles downstream of the CGS site) is accessible by barges with a maximum 16 ft of draft (normally 2500 to 3000 tons). The first use of this facility was in April 1973 when the FFTF reactor vessel was off-loaded. Traffic to the North Richland dock is very infrequent in comparison to that in Pasco and Kennewick due to the lack of large industrial concerns in the region between Richland and Priest Rapids Dam. This facility is most often used to off-load dismantled nuclear components. On several occasions in the past, COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-8 lightly loaded barges have transported material to the vicinity of the Hanford Site. This required maintenance of an adequate flow from Priest Rapids Dam during the transit period. 2.2.2.5 Airports Three commercial airports are within 20 miles of CGS. The closest is Richland Airport 11 miles south of the plant. This general aviation airport has two 4000-ft runways, one with a 010/190 orientation and the other with a 070/250 orientation. Visual flight rule landings are standard for Federal Aviation Administration (FAA) non-control-tower airports.

The Tri-Cities Airport 17 miles southeast near Pasco is the largest airport within 40 miles. The FAA operates the air traffic tower and airport radar approval control facility. The airport has two 7700-ft crossing runways with 120/300 and 030/210 orientations. The latter has a 4430-ft parallel runway. Runway 30 has a very high frequency omnirange (VOR) instrument approach and Runway 21R has an instrument landing system and is an instrument approach runway.

The Vista Airport operated by the Port of Kennewick is a general aviation airport located 18 miles south-southeast. It has a 4000-ft runway with a 20/200 orientation. All operations are under visual flight rules.

Information relative to the flight paths and activity at these three commercial airports, the Yakima Training Center, and the nearby private airstrips is discussed in Section 3.5.1.6.

2.2.2.6 Projection of Industrial Growth There is no projected growth of waterway traffic nor plans for oil and gas pipelines within 10 miles of CGS.

2.2.3 EVALUATION OF POTENTIAL ACCIDENTS

2.2.3.1 Determination of Design Basis Events Energy Northwest has investigated the resistance of plant structures to explosions. The reactor building is a reinforced-concrete structure up to the refueling floor and is designed to withstand the worst probable combination of wind velocity and associated pressure drop due to a design basis tornado. A differential pressure of 3 psi between the exterior and interior of the building is also considered in the design. At its nearest point, the railroad is 510 ft from the reactor building.

From the above criteria, it has been determined that the reactor building can resist an explosion of 20,000 lb of dynamite on a railway car 510 ft from the reactor building. The performance of the reactor building structure for this blast loading condition will be similar to that for the COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-9 original design basis tornado loading condition based on the 3 psi differential pressure used in the original tornado analysis.

In the unlikely event of an explosion or fire on the railroad affecting the 115-kV shutdown power supply, the 230-kV power supply or the diesel generators would fulfill that function.

It is extremely unlikely that an explosion or fire on the mainline railroad would compromise the safe shutdown of the facility. As noted in Section 2.2.2.2, DOE has no plans to ship explosives on the railroad, and the agency will notify Energy Northwest prior to the shipment of explosives in a quantity greater than 1800 lb. Energy Northwest Security controls access to the rails that pass near the plant. The only explosives on the Hanford Site are small arms munitions. As described in Section 2.2.2.2, this represents no hazard to the operation of CGS. The Yakima Training Center does not endanger the site. Hydrogen gas stored in the gas bottle storage building and in a trailer parked adjacent to the gas bottle storage building will not pose any fire or explosion problem because of the light weight properties and dispersal qualities of the gas and the distances (approximately 400 ft) between the storage areas and any safety-related equipment. Hydrogen gas stored at the Hydrogen Storage and Supply Facility (HSSF) and transported to the plant by pipeline does not pose a significant fire or explosion risk to the plant as discussed in Appendix F and Section 3.5.1.5. Habitability considerations for the control room and quantities of hydrogen gas stored in/adjacent to the gas bottle storage building and at the HSSF are discussed in Section 6.4.4.2.3.

Table 2.2-1 summarizes the potential events at the Hanford Site facilities that could present a radiological or chemical hazard or hazardous situation to the continued safe operation of CGS. The cesium and strontium capsules stored at the Waste Encapsulation and Storage Facility (WESF), the fuel stored at the K Basins, and the high level waste stored in the tank farms present contributions to risk at CGS due to presence of 137Cs, 90Sr, and 241Am. However, based on consideration of the radionuclide inventory at risk, the ability to transport this inventory, and the proximity of the storage facility, the risk is dominated by the inventory stored at WESF. The probability of the loss of cooling in the capsule storage pool is extremely low, but the potential dose to unprotected CGS personnel due to the release is significant. Any required evacuations would be performed as discussed in the Emergency Plan. The design basis accident at WESF would not result in a condition at CGS which would challenge the criteria established in 10 CFR 100.

In each event evaluated, the radiological dose resulting from particulate releases would be adequately filtered by the control room HEPA filters, mitigating any challenge to the habitability of the control room. None of the facilities present a chemical exposure risk to CGS. Radiological exposures for postulated events on the Hanford Site are characterized by the contribution from gaseous radionuclides because of the short half-life of 131I and because the other noble gases were released during the spent fuel processing.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-10 The Yakima Training Center, discussed in Section 2.2.2.2, is used for military maneuvers and weapons training and is the only significant military activity in the vicinity of the Hanford Site. The only weapon currently in use at the Yakima Training Center known to present a hazard to the Hanford Site is the multiple launch rocket system (MLRS). With a range in excess of 25 miles, the MLRS could potentially impact the CGS site. However, the MLRS is only fired from the perimeter of the Yakima Training Center into a centrally located impact zone and is only fired with dummy warheads. Given this information, additional safety features, and the administrative controls in place at the Yakima Training Center, a weapons accident having an impact on CGS is very improbable.

The Umatilla Chemical Depot, discussed in Section 2.2.2.1, is used to store chemical weapons. As part of the program to demilitarize chemical weapons, an incinerator has been constructed at the Depot for disposal of the weapons. Risks associated with weapons disposal operations at the Umatilla Chemical Depot have been quantified in a Phase 1 Quantitative Risk Assessment (QRA) prepared for the U.S. Army. The QRA examined risks associated with storing munitions at the Depot, transporting munitions from the storage igloos to the incinerator, and processing munitions within the incinerator. Although not directly transferable to the assessment of effects at CGS, the risk estimates provide some inferences regarding the risks to plant operation. A review of the assessment concluded that the risk to persons in the 60 to 100 km distance range due to chemical munitions disposal are very small. It should also be recognized that operations at the Depot would be within the scope of a comprehensive emergency preparedness program that includes offsite notification. Furthermore, pursuant to Regulatory Guide 1.78, chemicals stored or situated at distances greater than 5 miles from CGS need not be considered because, if a release were to occur, atmospheric dispersion will dilute and disperse the incoming plume to such a degree that either toxic limits will never be reached or there would be sufficient time for control room operators to take appropriate action. In addition, the probability of a plume remaining within a given sector for a long period of time is quite small (Reference 2.2-9).

As stated in Section 2.2.2.1, confinement of all radioactive materials at the ISFSI is provided by the required use of NRC certified spent fuel storage casks listed in 10 CFR 72.214. Pursuant to the 10 CFR 72.212 report, evaluations performed in support of the ISFSI have demonstrated the reactor site-specific parameters are bounded by the safety analysis for the generically approved cask. Accordingly, activities associated with the facility do not adversely impact operation of CGS (Reference 2.2-10).

Brush fires have occurred on the Hanford Site and have presented no potential hazard to existing facilities. Areas adjacent to CGS major buildings and auxiliary facilities are maintained to prevent weed growth by landscaping, gravel, ground cover, and weed control spraying. The Hydrogen Storage and Supply Facility (HSSF) is landscaped with gravel beyond the perimeter of the site, exceeding the code required clearance distance, to keep the area free from dry vegetation and combustible materials. These or similar methods of weed control minimize brush fire hazards to CGS facilities.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-11 The potential effects of fires that involve materials used in the operation of the plant are discussed in Appendix F.

The formation of unconfined vapor clouds caused by the accidental release of flammable or toxic liquids or vapors stored at the plant site is discussed in Section 6.4 and addressed by the Emergency Plan.

The non-safety-related makeup water intake consists of two sets of paired perforated pipe sections. One set is capable of supplying the full makeup water requirements of the plant. Extreme low river flow (36,000 cfs) will provide about 0.5 ft of water over the top of the intake pipes. The probability of damage to both sets of intakes as a result of a pleasure boat or barge accident is extremely remote given the infrequency of both extreme low flows and large boat and barge traffic. In the unlikely event that such an accident might occur, destruction of the makeup water intake structure would be comparable in effect to loss of offsite power to the makeup water pumps. The Seismic Category I spray ponds provide for 30-day cooling without makeup. This is ample time to restore makeup from either the river or wells.

There are no upstream industrial facilities for which waterborne deliveries of significant quantities of petroleum products, corrosive chemicals, or other hazardous materials are expected. Fuel oil, diesel oil, acids, and caustics are stored at the N-Reactor site. The oil storage facilities are protected by dikes, and the chemical storage facilities are far enough from the river to avoid direct discharge. Thus, there is no possible hazard to the plant due to spillage of such materials into the river. There are no upstream releases which may be corrosive, cryogenic, or coagulant.

2.2.3.2 Effects of Design Basis Events As discussed in Section 2.2.3.1, the activities of nearby industrial, transportation, and military facilities will have no adverse effect on the plant.

2.

2.4 REFERENCES

2.2-1 Holmes, D. B., Energy Northwest, personal communication with Steve Burnam, Site Infrastructure Division, Department of Energy, July 31, 1998.

2.2-2 Presidential Proclamation 7319, Establishment of the Hanford Reach National Monument, 65 FR 37253, June 9, 2000.

2.2-3 Chasse, J. P., Energy Northwest, personal communication with B. J. Rokkan, Safeguards and Security Division, DOE, Richland Operations Office, December 6, 1977.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-12 2.2-4 Note, D. A. Marsh, Westinghouse Hanford, to D. E. Larson, Supply System, dated January 22, 1993. 2.2-5 Memorandum, C. A. Hansen, Assistant Manager for Waste Management, DOE-RL to Alice Q. Murphy et al., 98-WPD-032, February 20, 1998.

2.2-6 NUREG 0892, Safety Evaluation Report Related to the Operation of WPPSS Nuclear Project No. 2, Section 2.2.1, March 1982.

2.2-7 Arbuckle, J. D., Energy Northwest, personal communication with J. Reddick, Executive Officer, Yakima Training Center, July 29, 2003.

2.2-8 Hosler, A. G., Contact with Local Organizations to Support CSB SAR Chapter 1 (Memo 042AGH.96 to Canister Storage Building Report File), Science Applications International Corporation, May 6, 1998.

2.2-9 Holmes, D. P and Chasse, J. P., Energy Northwest, White Paper -- Applicability of the Chemical Stockpile Disposal Program at the Umatilla Army Depot to the WNP-2 FSAR, December 1997.

2.2-10 Energy Northwest, Independent Spent Fuel Storage Installation 10 CFR 72.212 Evaluation, Docket Number 72-35, Revision 1, September 2002.

Table 2.2-1 Hanford Site Nuclear Facilities Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-11-027 2.2-13Fast Flux Test Facility (FFTF) Ref: Surveillance and Maintenance Plan for FFTF, Rev. 0, DOE/RL-2009-26 Deactivated sodium cooled breeder reactor Activated solid sodium 1) 180,000 lb sodium spill hr dose at 1.5 mi = 0.015 mrem, 24-hr dose at 4.5 mi = 0.26 mrem Particulate release, effectively mitigated by distance DOE 618-10 (300 North) Waste Burial Ground Ref: Final Hazard Categorization for the 618-10 Burial Ground Remediation, Rev.2, February 2011, WCH-390 Disposal site with broad spectrum of low- to high-level solid radioactive wastes buried in caissons or pipe Radioactive waste Caisson penetration with fire - unmitigated dose at 5 km = 10.2 mrem Particulate release, effectively mitigated by distance (>5 km) DOE 618-11 (Wye) Waste Burial Ground Ref: 618-10 and 618-11 Waste Burial Grounds Basis for Interim Operation, Rev. 1, WCH-183 Disposal site with broad spectrum of low- to high-level solid radioactive wastes and non-radiological hazardous materials buried in caissons or pipe Radioactive waste inventories, primarily Cs-137, Sr-90, and Pu-239 and non-radiological hazardous materials bounded by beryllium Caisson penetration with fire and explosion: control room doses are less than 0.1 rem; beryllium oxide concentration of 4.6 x 10-3 mg/m3 at 100 m from 618-11 site boundary Particulate release, effectively mitigated by credited 618-11 Waste Burial Ground project controls. The soil overburden covering the VPUs and caissons in the 618-11 Waste Burial Ground is credited for reducing releases and is designated as a passive design feature. No missiles are postulated for this event.

Table 2.2-1 Hanford Site Nuclear Facilities (Continued) Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORTDecember 2011 2.2-14 B Plant Ref: B Plant Basis for Interim Operation, March 6, 1997, HNF-SD-BIO-003 Process to remove cesium and strontium from radioactive waste, deactivated, currently in surveillance and maintenance mode Residual radionuclide inventories on cell filters (137Cs, 90Sr, and 241Am) Flooding cell 291-B HEPA filters - 0.368 rem max. public dose Particulate release effectively mitigated by distance Plutonium-Uranium Extraction Facility (PUREX). PUREX End State Basis for Interim Operation (BIO) 1997, HNF-SD-CP-15B-004 (Draft) Currently shut down, in preparation for decommissioning and decontamination Residual plutonium and uranium contamination Design basis earthquake, dose @ 100 m - 1.9 rem; 12 km - 7.4 x 10-4 rem Particulate release, mitigated by distance Plutonium Finishing Plant (PFP) Ref: Plutonium Finishing Plant Final Safety Analysis Report, 1995, WHC-SD-CP-SAR-021 Receipt and storage of SNM, reactive material stabilization, radioactive and mixed waste handling Stored SNM, and residual plutonium contamination Design basis earthquake, 8-hr dose of 15.2 rem @550 m 24-hr dose of 0.31 rem @12,500 m Particulate release, mitigated by distance Tank Waste Remediation System (TWRS) Facilities Ref: Tank Waste Remediation System Basis for Interim Operation, 1997, HNF-SD-WM-BIO-00, Revision 0 Mixed radioactive and chemical wastes storage in 149 single shell tanks (SST) and 28 double shell tanks (DST) in 12 tank farms

Associated support facility: 242-A-Evaporator SSTs contain combinations of sludge, saltcake, and interstitial and pooled liquids

DSTs contain liquid and slurry waste with small amounts of sludge Table 2.2-1 Hanford Site Nuclear Facilities (Continued) Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORTDecember 2011 2.2-15Tank Waste Remediation System- Project (TWRS-P) (private facilities, proposed for construction in 2000) Ref: DOE/RL-96-0006 Vitrify low level, high level, and transuranic mixed waste High level radioactive waste Requirements for authorization limit to less than 25 rem/event in an accident. Releases are projected to be airborne particulate. HEPA filter system would protect CGS control room operators, in accordance with the limits of GDC 19 Waste Encapsulation and Storage Facility (WESF)

Ref: Waste Encapsulation and Storage Facility Basis for Interim Operation, 1997, HNF-SD-WM-BIO-002 Conversion process for cesium and strontium has halted Cesium chloride and strontium fluoride salts, encapsulated in double-walled metal containers stored in water-filled cooling basin Capsule rupture following loss of water from storage pool - 24 hr exposure to public, 9 rem Control room exposure mitigated by HEPA filters; potential evacuation of other personnel Low-Level Waste Disposal Site (Private) Buried storage of low-level radioactive waste in lined containers Low-level buried waste, monitored as required by NRC license No credible event None Canister Storage Building (CSB)

Ref: Letter; DOE to H. J. Hatch, Flour Daniel Hanford, 28 May 97 Storage of spent nuclear fuel (SNF) from the K Basins in sealed multi-canister overpacks (MCO) 2100 metric tons of spent fuel, from production reactors Requirements for authorization limit to less than 5 rem/event in an accident. Releases are projected to be airborne particulate HEPA filter system would protect CGS control room operators, in accordance with the limits of GDC 19 Cold Vacuum Drying Facility (CVDS) Ref: Letter; DOE to H. J. Hatch, Flour Daniel Hanford, 28 May 97 Draining and vacuum drying to remove water from MCOs in preparation for interim storage at CSB Spray release Requirements for authorization limit to less than 5 rem/event in an accident. Releases are projected to be airborne particulate. HEPA filter system would protect CGS control room operators, in accordance with the limits of GDC 19 Table 2.2-1 Hanford Site Nuclear Facilities (Continued) Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORTDecember 2011 2.2-16B, C, D, DR, F, and H Reactors (shutdown since 1969)

Ref: WHC-EP-0619, Vol. 1. Single-pass, water-cooled, graphite-moderated reactors The onsite hazards involve personnel injury, primarily falls and electric shock. No significant offsite risks No credible event None K East and West reactors (shutdown since 1971)

Ref: WHC-EP-0619, Vol. 1. Single-pass, water-cooled, graphite-moderated reactors The onsite hazards involve personnel injury, primarily falls and electric shock. No significant offsite risks No credible event None K East and West Basins Ref: WHC-EP-0619, Vol. 1. Storage basins for spent fuel, some severely degraded Approximately 2100 metric ton inventory of irradiated reactor fuel Dropping and overturning of a transfer cask containing reactor fuel. (Bounding event; but transfer is administratively prohibited) None N reactor (shutdown since 1987) and N Basin Ref: WHC-EP-0619, Vol. 1. and BHI-00866, Rev 0 A pressure tube, water-cooled, graphite-moderated reactor with fuel assemblies removed for decontamination and decommissioning The onsite hazards involve personnel injury, primarily falls and electric shock. No significant offsite risks No credible event None Amendment 55May 2001Hanford Reservation Road System990306.152.2-1FigureForm No. 960690Draw. No.Rev.Arid LandsEcology ReserveColumbia RiverRichlandBenton CityYakima RiverWNP-1WNP-4* HANFORD RESERVATION ROADS STATE HIGHWAYS

• WNP-4 HAS BEEN TERMINATED108642021MILES22424240243242224200W200EColumbia Generating StationFinal Safety Analysis ReportColumbiaGeneratingStation12121212 Amendment 55May 2001Hanford Reservation Railroad System990306.162.2-2FigureForm No. 960690Draw. No.Rev.Arid LandsEcology ReserveHanford No. 1Columbia RiverRichlandBenton CityYakima RiverColumbiaGeneratingStationWNP-1WNP-4* HANFORD RAILROAD SYSTEM* WNP-4 HAS BEEN TERMINATED108642021MILESColumbia Generating StationFinal Safety Analysis Report NORTHFigureAmendment 57December 2003Form No. 960690Draw. No.Rev.Federal Airways and InstrumentApproaches/Departures900547.962.2-3Columbia Generating StationFinal Safety Analysis ReportSUNNYSIDEPROSSERBentonCountyRICHLANDPASCOCOLUMBIACOLUMBIA RIVERAGCARRKENNEWICKVISTAFFTFCOLUMBIAAG 2BASIN CITYWye BarricadeMcWHORTERHanford SiteBoundaryMATTAWAGrantCountyChristensenBros.DESERT AIR301V187°Adams CountyTAGGARESFIELDKENTFARMSOTHELLOCONNELCITYFranklin CountyGREENACRES332°YakimaTrainingCenterCGS200West200EastSLINKARD269°2424324172404SVR1350V281IR329IR329IR329VR1351VR1360VR497V2041239539539582182 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-1 2.3 METEOROLOGY The italicized information, including associated tables and figures, is historical and was provided to support the application for an operating license.

2.3.1 REGIONAL CLIMATOLOGY*

2.3.1.1 General Climate The site is located in a mid-latitude semi-arid (steppe) climatic region in the Lower Columbia Basin which is the lowest elevation of any part of central Washington. A major factor influencing this climatological region is its location in the continent, well away from the windward coast and protected to the west by the 4,000 to 7,000-ft average elevation Cascade Mountains. Dominant air masses affecting the region are of maritime polar origin as modified by the presence of these mountains. Modified continental tropical and polar air masses also periodically affect the climate. In winter, there is a succession of cyclones as the westerlies and the polar front prevail in these latitudes. The mountain barriers commonly induce these storms to occlude by delaying air mass movement. Fewer frontal passages occur during the summer months since subtropical oceanic high cells reach their highest latitudes thereby diverting cyclonic storms poleward. Along the eastern margin of the Pacific anticyclone, an out-flow of stable subsiding air brings distinctly drier conditions to the North American Pacific coast.

The regional temperatures, precipitation, and winds are greatly affected by the presence of the mountain barriers. The Rocky Mountains and ranges in Southern British Columbia are effective in protecting the inland basin from the more severe winter storms and associated cold polar air masses moving southward across Canada. Occasionally, an outbreak of cold air will pass through the Basin and result in low temperatures or a damaging spring or fall frost. Maritime polar air traveling eastward from the coastal zone cools as it rises along the western slope of the Cascade Range. These orographic effects cause heavy precipitation on the windward and light precipitation on the leeward slopes. The prevailing westerly. winds are normally strongest during winter and spring due to the presence of cyclonic scale disturbances and associated frontal activity. During those months, foehn or chinook winds (a warm dry

• This section is based on records kept at the Hanford Meteorology Station (14 miles northwest of the site, elevation 733 ft MSL) from 1945 to 1980 (2) and 100-N area sites (1) (supplemented with precipitation and temperature data taken by U.S. Weather Bureau cooperative observers at a site about 25 miles north of the present station location during the period from 1912 to 1944 (2,3) and regional climatological data gathered during the period from 1931 to 1960). (4) Other references are as indicated.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-2 wind on the lee side of a mountain range; the warmth and dryness of the air is due to adiabatic compression upon descending the mountain slopes) occur whenever cyclonic circulation is sufficiently strong and deep to force air completely across the cascades in a short period of time. At other times during the winter, warm front occlusions can force moist air over the Cascade Range. The mixing of this moist air with relatively cooler air in the Basin results in considerable cloudiness and fog. The percent of possible sunshine ranges from 20 to 30 percent in winter, 50 to 60 percent in spring and fall, and 80 to 85 percent in mid-summer. Because the site is in the rain shadow of these mountains, annual average precipitation decreases from about 100 inches near the summit of the Cascades to about 6 or 7 inches in the Basin. Approximately 70 percent of the annual total precipitation occurs from November through April and about 10 percent occurs during July through September. Rainfall amounts are normally light in the summer and gradually increase in late fall, reaching a peak of about one inch each month in midwinter due to cyclonic storm and frontal activity. Rainfall amounts decrease in Spring, increase somewhat in June, and again sharply decrease in July. During mid-summer, it is not uncommon to have 3- to 6-week periods with trace rainfall. There are only two occurrences per year of 24-hour amounts of 0.50 inch or more, while occurrences of 24-hour amounts of 1.00 inch or more number only four in the entire 25 years of record (1946 to 1970). One of these was the record storm of October 1 through 2, 1957, in which rainfall totaled 1.08 inches in three hours, 1.68 inches in six hours, and 1.88 inches in twelve hours. At the other extreme, there have been 81 consecutive days without measurable rain (June 22 through September 10, 1967), 139 days with only 0.18 inch (June 22 through November 7, 1967), and 172 days with only 0.32 inch (February 24 through August 13, 1968).

About 45 percent of all precipitation during the months of December, January, and February is in the form of snow. Regional annual total snowfall amounts have ranged from less than 1/2 inch in 1957 to 1958 to 56.1 inches for the winter of 1992-1993; the annual average total is about 14 inches.

Snow rarely remains on the ground longer than two to four weeks or reaches a depth at any time in excess of four to six inches, as rapid melting, which often contributes to local stream flooding, can occur from rain or Chinook winds. The record greatest depth of 24.5 inches occurred in February 1916.

Thunderstorms have been observed in the area in every month except November. Although severe ones are rare, lightning strikes have occasionally ignited grass fires which burned thousands of acres of the Hanford Reservation and resulted subsequently in considerable wind erosion of soil. The most notable of these occurrences were in August 1961, July 1963, and July 1970, and August 1984.

The continental-type climate not only affects precipitation in the Basin but also results in wide ranges and variations in annual temperature conditions. While the regional annual average temperature is about 53°F, the coldest month, January, has a mean of about 29°F; the COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-3 warmest month, July, has a mean of about 76°F. Although the presence of the cascades contributes to the wide differences in monthly average temperatures, other mountain ranges shield the area from many of the arctic surges, and half of all winters are free of temperatures as low as 0°F. However, six winters in 58 of record have contributed a total of 16 days with temperatures of -20F or below; and in January to February 1950, there were four consecutive such days. There are ten days of record when even the maximum temperature failed to rise above zero. At the other extreme, in the winter of 1925 to 1926, the lowest temperature all season was +22F. Although winter minima have varied from -27F to +22F, summer maxima have varied only from 100°F to 115°F. However, there is considerable variation in the frequency of such maxima. In 1954, for example, there was only one day with a maximum as high as 100°F. On the other hand, there have been two summers (1938 and 1967) when the temperature went to 100°F or above for 11 consecutive days.

Although temperatures reach 90°F or above on about 56 days a year, there are only about seven annual occurrences of overnight minima 70°F or above. The usual cool nights are a result of gravity winds.

The channeling of air by the Cascade Mountains and surrounding terrain produces a prevailing WNW and NW regional flow. Local topographic features can cause other channeling effects and formation of local diurnal wind circulation systems which produce a greater degree of variability in winds at locations within the Basin. For example, the Columbia Generating Station (CGS) site experiences a bimodal wind direction distribution from approximately south and also northwest; at the Hanford Meteorological Station (HMS) about 14 miles northwest, the direction distribution displays a single peak at approximately WNW to NW (refer to 2.3.2).

Drainage (gravity) winds channeled by topographic features produce a marked effect on diurnal range of wind speed and cause the highest monthly average speeds of about 9 mph to occur during the summer months. In July, for example, hourly average speeds range from a low of 5.2 mph from 9 to 10 a.m. to a high of 13.0 mph from 9 to 10 p.m. In contrast, the corresponding speeds in January are 5.5 and 6.3 mph. These warm season diurnal winds, resulting from relatively cold air draining from the Cascade Mountains, occur in response to pressure gradients created between surface-heated warm, dry basin air and cooler air situated over the mountains and coastal region. This favors an outbreak of stronger winds during the afternoon and evening hours. Although the gravity wind occurs with regularity in summer, it is never strong unless reinforced by frontal activity. In June, the month of highest average speed, there are fewer instances of hourly averages exceeding 31 mph than in December, the month of lowest average speed. A complete summary of the monthly averages and extremes of climatic elements at the Hanford Reservation appears in Table 2.3-1.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-4 2.3.1.2 Regional Meteorological Conditions for Design and Operating Bases 2.3.1.2.1 Severe Weather Phenomena

2.3.1.2.1.1 Heavy Rain, Snow, and Ice. Glaze is a coating of ice, generally clear and smooth, but with some air pockets. It is formed on exposed objects by the freezing of super-cooled drizzle or rain drops. Glaze is denser, harder, and more transparent than either rime or hoar frost. Although the record shows an average of seven glaze days per year, many of these cause little or no inconvenience to the public. Two outstanding exceptions occurred on February 11 to 12, 1954, and on November 23 to 24, 1970. There was serious disruption to Hanford traffic in each instance although there was no known damage to transmission lines. In each instance, rising temperatures soon melted the ice.

Precipitation frequency (rain and snow), intensity, and quantity statistics are presented in Figures 2.3-1 and 2.3-2 and Tables 2.3-2 and 2.3-3. For the winter of 1992-93, the following snowfall records were set: greatest winter snowfall (56.1 inches); most days with greater than 1, 6, and 12 inches on the ground (71, 41, and 9, respectively); and greatest 24-hour snowfall (10.2 inches) on February 18 and 19. Probable maximum precipitation is given in 2.4.3.1.

2.3.1.2.1.2 Thunderstorms and Hail. Thunderstorms may occur during any month of the year at Hanford. A thunderstorm day is one in which thunder is heard. If a thunderstorm should begin in late evening and last past midnight, it is counted as two thunderstorm days even though only one storm event occurred. Similarly, should there be two or more distinct thunderstorms in a day - and this sometimes happens - it is counted as a single thunderstorm day. The table below shows the monthly frequency of thunderstorms.

HMS THUNDERSTORM DAYS: 1945-1970

J F M A M J J A S O N D SUM Total 0 1 7 18 53 64 46 54 24 5 0 0 272 Average 0 # # 1 2 3 2 2 1 # 0 0 11 % of Total 0 # 3 7 19 23 17 20 9 2 0 0 100 # = Less than 0.5 Although the table above shows 0 for the months of November through January, a thunderstorm occurred at HMS on December 22, 1971. In Richland, one occurred on January 18, 1953. However, the thunderstorm season essentially includes only the months of April through September. Although the average is eleven days per year, the number has varied from three to twenty-three. In June 1948, there were eight thunderstorm days during the month; and this record was repeated in August 1953. The records show that cold fronts probably constitute the greatest single cause of thunderstorms at HMS. During the years of 1947 to 1955, 43 percent of all thunderstorm days during the months of May through August COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-5 were directly associated with cold frontal passages. On several occasions (notably on August 7, 1953), lightning has struck the HMS tower.

Peak gust data are not available for the 50-, 200-, and 400- ft levels prior to 1952. Of the 185 thunderstorm days occurring during the period of 1952 to 1970, the speed classification of peak gusts on these days is as follows:

Number of Cases  % of Total mph 50 ft 200 ft 400 ft 50 ft 200 ft 400 ft < 21 18 9 5 10 5 3 21 -30 75 45 42 40 24 23 31 -40 63 80 73 34 43 39 41 -50 23 34 46 12 19 25 51 -60 4 11 12 2 6 8 61 -70 1 4 5 1 2 3 > 70 1 2 2 1 1 1 185 185 185 100 100 100 Precipitation was not measured during 1945 and 1946 in which 26 thunderstorm days occurred. During the period of 1947 to 1970, 246 thunderstorm days were recorded. The daily precipitation distribution during these days was as follows:

Amount - Inches Number of Cases % of Total None or trace 110 45 0.01 - 0.10 87 35 0.11 - 0.25 29 12 0.26 - 0.50 15 6 > 0.50 5 2 246 100 Precipitation intensities are defined in Reference 2.3-5.

The record for rainfall intensity during a thunderstorm is 0.55 inch in 20 minutes (1.65 inches per hour) on June 12, 1969. This storm included hailstones of 1/4-inch diameter.

Hail was reported on fourteen, or 5 percent, of the total thunderstorm days. Blowing dust or dust was reported on sixteen thunderstorm days and both hail and blowing dust or dust on six days.

Hail is a rare phenomenon at Hanford. For all years of record, hail has not occurred more than twice in any year. Of the 272 thunderstorm days from 1945 to 1970, hail was reported on fourteen or 5 percent of these days. Hail was also reported on two days without occurrence COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-6 of either a cold frontal passage or a thunderstorm on the same day. The distribution by months of days on which hail occurred is as follows: J F M A M J J A S O N D Total Number 0 1 1 4 2 1 2 2 1 0 0 0 14 % of Total 0 7 7 30 14 7 14 14 7 0 0 0 100 Where size was reported, all except two reports indicated sizes in the 0.2- to 0.3-inch range. The exceptions were May 26, 1954, and July 1, 1955, when the size reported was 0.4 inch. There is no known case of local damage from hail. 2.3.1.2.1.3 Tornadoes

The State of Washington experiences, on the average, less than one tornado each year. Within a one hundred mile radius of the site, only fourteen tornadoes have been reported since 1916. These tornadoes are listed in Table 2.3-4. Of these fourteen recorded tornadoes, only five had any damage associated with them. A more extensive survey of tornadoes in the three northwestern states (Washington, Oregon, and Idaho) was performed by Fujita (6). His results indicate that tornadoes and hailstorms in this area occur primarily in "alleys". The locations of these "alleys" are shown in Figure 2.3-3 along with locations of tornadoes which have been recorded in the tri-state area during the twenty-year period from 1950 to 1969.

Jaech (7) has analyzed the data of Fujita (6) to determine the probability of a tornado striking the Jersey Nuclear Company Fuel Facility (now Siemens Power Corporation), which is located about eight miles from the site. His analysis estimates the probability of occurrence of a tornado in the vicinity of the Exxon site as six chances in a million during any given year or about one chance in four thousand during a forty-year plant life.

The peak tornado wind velocity estimated for the site is 214 mph (Reference 2.3-7). This includes an estimated maximum rotational and translational wind velocities (at a 95-percent confidence level). Daubek (Reference 2.3-8) estimates the maximum translational velocity to be 30 mph. The maximum pressure drop in the center of the tornado relative to the environment is estimated to be up to 1.5 psi (Reference 2.3-6). These values are equal to or less than those tornado parameters listed for a Class III region (which includes the site location) in Regulatory Guide 1.76, issued April 1974. Prior to the issuance of this guide, CGS was designed to withstand some of the most stringent NRC tornado criteria presented for a site located within a Class I region.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-7 A comparison between criteria used for CGS and those applicable to Class I and III regions are given below:

Design Basis Tornado Characteristics

Maximum Wind Rotational Translational Speed (mph) Speed (mph) Speed (mph) Maximum Minimum Class I Region 360 290 70 5 Class III Region 240 190 50 5 CGS 360 300 60 - Radius of Maximum Rotational Speed (ft) Pressure Drop (psi) Rate of Pressure Drop (psi/sec) Class I Region 150 3.0 2.0 Class III Region 150 1.5 0.6 CGS 264 - 880 3.0 1.0

Wind and tornado loading criteria used in the CGS structural design are discussed in Section 3.3.

2.3.1.2.1.4 Strong Winds. The Hanford region experiences high wind speeds due to squall lines, frontal passages, strong pressure gradients and thunderstorms. The Hanford Reservation has experienced only one recorded tornado (June 1948) and has not been known to be affected by typhoons. No complete statistics are readily available which present frequency of occurrence of high winds produced or accompanied by a particular meteorological event.

However, the highest winds produced by any cause are tabulated for HMS in Tables 2.3-5 and 2.3-6. Figure 2.3-4 indicates the return probability of any peak wind gust, again due to any cause.

The speed-direction summary (Table 2.3-6) shows that daily peak gusts of at least 40 mph have occurred from all but four of the sixteen compass points indicated. The SW octant, however, accounts for 65 percent of such cases. The SSW octant accounts for 83 percent of daily peak gusts of 50 mph or over and 100 percent of those 60 mph or over. Since WNW and NW are the most frequently observed directions at HMS, they account for almost half of all daily peak gusts. However, less than 3 percent of these are at speeds of 40 mph or more. By contrast, 23 percent of daily peak gusts from the SSW and SW attain this speed. Although the winter season has a lower average wind speed than any other, it also has the greatest frequency of days with peak gusts 40 mph or over (10 percent). This compares with 8 percent for spring, 7 percent for fall, and 5 percent for summer. However, reflecting the frequent periods of stagnation in winter, this season also has the highest frequency of days with peak gusts under Peak wind gust data associated with thunderstorm activity are given in 2.3.1.2.1.2.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-8 10 mph (16 percent). This compares with 10 percent for fall and 1 percent for spring. In summer, such days are virtually non-existent with only one being tabulated in 1,102 days of record. About 60 percent of the days from May through August experience drainage winds of at least 13 mph from the west direction for at least two hours daily during the period of 1600 to 2400 PST.

The annual extreme fastest mile of wind speed* for a given region has been commonly used as the best available measure of wind for design purposes (Reference 2.3-9). The standard reference speed level is normally chosen at the 30-ft elevation, and wind speed is assumed to vary with the one-seventh power of height.

All CGS structures have been designed to withstand a basic wind (fastest mile) velocity, including gusts of 100 mph at an elevation of 30 ft above the site grade. This design speed value is conservative for the CGS site since the 100 year return period peak gust as shown in Figure 2.3-4 at HMS is 86 mph at an elevation of 50 ft (as given in Tables 2.3-5 and 2.3-6 at that level peak gusts have not exceeded 80 mph during the period 1945 to present). The 100 year return period fastest mile of wind would be less than 86 mph since by definition gust velocity divided by an appropriate gust factor provides the velocity of the fastest mile of wind. Although not recorded in historical records the 100 year fastest mile of wind can be expected to be in the range of 66 to 78 mph. These values are based on the application of gust factors of 1.3 and 1.1 (Reference 2.3-10) for gusts of one and 10 sec durations** respectively to the estimated historical value of 86 mph.

2.3.1.2.1.5 High Air Pollution Potential (APP) and Dust Storm Potential. Larson (11) has concluded that "consideration of the general weather parameters indicates a significantly high average annual APP over southeastern Washington." Holzworth (12) has estimated that the mean maximum January mixing depth in the Hanford area is about 250 meters, which is nearly the lowest in the contiguous United States, and for July about 2,000 meters. Hosler (13) has indicated a significantly high frequency of low-level inversion in winter over this area - on the order of 43 percent with bases below 150 meters. The occurrence of very stable and moderately stable conditions between the surface and 60 meters in winter at the Hanford Meteorology Tower is 66.5 percent.

Stagnation is defined by Huschke (14) as "the persistence of a given volume of air over a region, permitting an abnormal buildup of pollutants from sources within the region". Defining the establishment of stagnation as an uninterrupted period of daily average wind speed of 5.0 miles per hour or less and/or a peak gust of 15 miles per hour or less, Jenne (15)

• Fastest mile of wind is generally defined as either the fastest speed associated with 1 mile of passing wind or fastest observed 1 minute wind speed. ** According to Huschke (Glossary of Meteorology, 1959), the duration of a gust is usually less than 20 seconds.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-9 compiled a 15-year summary of Hanford stagnation periods covering the months of November through February (1947-48 through 1961-62). Both of the two most notable Hanford stagnation periods experienced during this time occurred in November and December 1952. The first period was from November 15 to December 3 (19 days). Then, after five days of ventilation, stagnation set in again December 9 and lasted through December 28 (20 days). Average wind speeds during the two periods were respectively, 2.6 and 2.9 miles per hour. Eleven days during the first period and eight during the second had peak gusts under 10 miles per hour. One day during the first period and two during the second had average speeds less than 1.0 miles per hour with peak "gusts" of 4 miles per hour. There were 13 days of fog in each period.

Although stagnation lasting for 20 days can be expected only one season in twenty, a 10-day stagnation period can be expected every other season. Only one season in three will fail to produce a stagnation period of at least eight days.

Air quality in the Hanford area, in terms of sulfur dioxide, nitrogen dioxide, and suspended particulates, is routinely measured by the Hanford Environmental Health Foundation. (18,29)

For the year 1971, SO2 measurement in Richland averaged less than 0.02 ppm. At other sampling stations, the concentrations were below the detection limit of 0.01 ppm. In 1974, all 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> sequential samples of SO2 measured in the vicinity of Richland, North Richland, and Hanford 300 Area had concentrations below the detection limit of 0.005 ppm which is 25% of the annual average ambient air standard of 0.02 ppm. The 1971 and 1974 measurements for NO2 and suspended particulates are shown below: Air Quality Measurements-Annual Averages for 1971 and 1974 (18, 29* ) (these data are based on 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> integrated samples) NO2 (pom) Location No. of Samples Max. Min. Avg. Richland (747 Building) 49 6.8 0.06 0.86 Opposite Richland 170 0.019 <.001 0.005 (Hobkirk Ranch) ( 78) (0.022) (0.001) (0.006)

Opposite N.

Richland 157 3.0 <.001 0.024

• Concentrations in parentheses are for 1974. ** High value due to a local dust storm.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-10 (Gilliam Ranch) (130) (0.020) (0.001) (0.006) Opposite 300 Area 170 0.025 0.001 0.005 (Sullivan Ranch) ( 77) (0.014) (0.001) (0.005)

Ringold 166 0.028 0.001 0.006 (Keys Ranch)

White Bluffs 149 0.028 0.001 0.006 (McLane Ranch) Suspended Particulate (g/m+3)

Location No. of Samples Max. Min. Avg. Richland (747 Building) 42 (125) 440 (572)** 25 ( 8) 120 ( 57) Opposite Richland - - - -

(Hobkirk Ranch)

Opposite N. Richland - - - -

(Gilliam Ranch)

Opposite 300 Area - - - - (Sullivan Ranch)

Ringold - - - - (Keys Ranch)

White Bluffs - - - -

(McLane Ranch) The major cause of air pollution in the Hanford area is dust occurring during windy periods. The most significant sources are cultivated fields in the surrounding area. A limited amount of information is available regarding atmospheric dust loading in the Hanford area. Hilst and Nickola (16) conducted limited dust investigations over a range of wind speeds and to heights of 400 feet in the Hanford area. A portion of their findings is presented in Figure 2.3-5. Other investigations which have been made in the Hanford area and reported by Sehmel and Lloyd (17) demonstrate the dependence of airborne concentrations on wind speed as shown in Figure 2.3-6.

Measurements of the particulate burden in air at a specific observation point in the 200 Areas at Hanford showed values of around 100 micrograms per cubic meter of air when the wind was less than 8 mph. The particulate content increased when higher winds were present, averaging 1,000 micrograms per cubic meter with winds of 12 mph, and 3,000 micrograms per cubic meter with winds of 16 mph.

Additional considerations regarding the August 11, 1955 and January 11, 1972 dust storms shown in Figures 2.3-5 and 2.3-6 and other climatological dust storm characteristics at Hanford are contained in the following paragraphs.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-11 2.3.1.2.1.5.1 Evaluation of August 11, 1955 and January 11, 1972 Dust Storms at Hanford. The wind speeds at 1.25 ft., 50 ft. and 400 ft. heights for the August 11, 1955 observation period were 14, 24, 31 mph respectively. Figure 2.3-5 represents atypical conditions for the site region. The case was originally selected for study as a situation with considerable airborne dust conditions compared to average conditions. A Hanford climatological summary of dust storms is given in Table 2.3-40 for 1953-1970 (30). Dust dependence on wind speed and direction (50 ft.) at the Hanford Meteorological Station is given in Table 2.3-41 for the same period (30). Approximate values of dust concentrations are computed based on an empirical relationship using visibility observations (31). The relationship is C656v1.25mg/m3 where V is horizontal visibility in km. This is based on data from the Great Plains with visibilities 7 to 9 miles and wind speeds greater than 12 mph. Hourly weather observations at the Hanford Meteorological Station were used as input criteria to define a wind resuspension or dust storm period. Hours satisfying dust storm criteria at Hanford (1953-1970) had either visibilities less than 7 miles and dust reported, or visibilities between 7-14 miles, wind speeds greater than 5.8 m/s, and relative humidities less than 70%. Since the above empirical concentration - visibility relationship was based on observed dust concentrations at approximately 5-6 feet above the surface, any measured dust data should be interpolated to that height when comparing the measurements to the calculated 1953-1970 results of Table 2.3-41. (30)

The frequency of the hourly data satisfying the dust storm criteria at Hanford is given in Table 2.3-42. (30)

The August 11, 1955 dust storm has an interpolated 5-ft value of 17 mg/m3 compared with the climatological average of about 7 mg/m3. Further inspection of the climatological values in Table 2.3-41, supports a conclusion that the storm is an example of the more severe type of dust storm that occurs in this region.

Care must be taken in interpretation of Tables 2.3-40 to 2.3-42 to allow for certain limitations. Estimates based on visibilities and/or wind speeds outside the range used in formulation of Equation 1 are of unknown reliability. The average visibilities within each wind speed class were within the range of empirical validity except for the high wind cases. Another source of errors is the fact that the visibility observations are taken at specific times and are not hourly averages. Considering these limitations Tables 2.3-40 to 2.3-42 may be taken to represent overall aspects of the Hanford dust storm climatology. Individual values must be considered approximate estimates - particularly those based on only a few data points.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-12 The extreme value in Table 2.3-41 in the 53 to 66 mph class (988 mg/m3) represents a single observation of 0-1/16 miles visibility for a few minutes. Typically at the onset of a dust storm very low visibilities with high winds occur for a few minutes. The very limited visibility and high winds for such a period were coded for the data for that hour. The station log reveals that five minutes after the onset of this dust storm, the winds had dropped to 37 mph and visibility was 3/8 mile. The phenomenon was generated by a thunderstorm passing close to the station. Hence, the extreme value in Table 2.3-41 represents an occurrence of very short duration which was the onset of a dust storm that had a duration of about one hour. Qualitative observation indicates that this is not an atypical scenario. Over the 40 minute duration of the storm, the average calculated average dust concentration was 60 mg/m3. It should be noted, however, that the onset concentration (988 mg/m3) is of unknown validity because it is calculated from a visibility value for which the empirical model has not been validated.

The visibility during the January 11, 1972 storm was initially less than one mile, changing to four miles during the last half hour of the reported episode. The January 11, 1972 dust storm had winds at 50' WSW in the range 31 to 43 mph. Wind storms with peak gusts recorded at 50' on the Hanford Tower during this period have a three to four year return period at Hanford.

Actual particulate loading depends on other factors such as surface conditions and atmospheric stability. Hence, the wind gust return period does not necessarily apply to particulate loading although it is reasonable to assume the return period is not less than that for wind.

Detailed estimates of the particulate size and total mass concentrations cannot be accurately made for the January 11, 1972 dust storm as a result of the lack of any particle size distribution data. In addition, only one height of mass concentration datum (189 mg/m3 at 0.2m) was made in the steep gradient region of the vertical profile. An indication of size distribution and mass loading profiles can be obtained from other data collected at Hanford. Sehmel (32) reports an April 1972 storm which has mass loadings near the surface which are similar to the January 11, 1972 storm. Although adjacent meteorological observations are not available for this episode, the fact that the mass loadings at the lower levels are of the same order as the January 11, 1972 dust storm provides a basis for comparison of the storms. The April 1972 storm has well documented mass loading profiles as a function of particle size. The table shown below contains the profiles of airborne soil concentrations as a function of particle diameter for the dust storm. These are based on optical measurements for smaller particles (.16 to 5 m) at 0.9m and, impacter-cowl measurements for larger particles (1 to 230 m) at the indicated heights. The mass loading is dominated by the larger particle data.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-13 Soil Mass Loading for the April 1972 Dust Storm (mg/m 3) Particle Height (m) Diameter Range ( m) 0.3 1.0 2.0 3.0 10. 32. 0.9 - 5.0 0.21 0.11 *

• 0.058 .0038 5 - 20 0.83 0.28 0.26 .25 0.070 .0056 20 - 60 14. 4.4 2.9 1.5 .81 .29 60 - 240 220. 6.6 2.8 1.3 .19 .11 Total 235 11.4 6.0 ~3.1 1.13 0.41 Comparison of the dust loading of 6.0 mg/m3 at 2 meters with the climatological summaries in Tables 2.3-41 and 2.3-42 indicates that this is a typical dust storm for the region.

The particle size distribution for the August 11, 1955 storm is shown in the following table for comparison.

Airborne Dust Loadings of Particles Greater Than 0.9 For August 11, 1955 Dust Storm (mg/m3) Particle Height (m) Diameter Range (m) 0.38 2.0 15.2 30.5 0.9 - 5.0 0.015 0.012 0.012 0.0079 5 - 20 0.39 0.32 0.23 0.17 20 - 60 3.1 2.2 1.1 0.77 60 - 240 18. 12.0 2.3 0.78 Total 22. 14.5 3.7 1.7 The April 1972 dust storm has higher mass loadings near the surface in all size ranges. The August 11, 1955 dust storm had higher dust loadings above 1 to 2 m heights in the ranges greater than 5 diameter. One interpretation of these profiles is that the 1972 storm had a source nearby and the 1955 data represents advection of airborne dust from more remote sources (33).

2.3.1.2.1.5.2 Hanford Dust Storm Climatology for Design and Operating Bases. The Hanford climatological study of dust storms for 1953-1970 (30) (discussed in the previous subsection) was re-examined for the purpose of establishing the "worst case" dust storm which may have occurred during that period (33). The worst case dust storm, i.e., that storm which had the largest calculated time integrated dust loading (mg-hr/m3), is considered to be

• No value in reference.

COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000 LDCN-98-117 2.3-14 160 mg-hr/m2, duration of 18 hr, and average dust loading of 8.9 mg/m3 at a height of 5 to 6 ft. The design basis dust storm is bounded by a postulated volcanic ashfall event (see Section 2.5.1.2.6) in the evaluation of the design and performance of HVAC systems and diesel generators. Results of this worst case dust storm investigation are listed below. As mentioned above, these loadings would apply for a height of 5 to 6 feet above the ground. Detailed Estimates of the Dust Loadings for the Six Worst Storms Based on Surface Observations of the Hanford Meteorology Station, 1953-1970 Storm Number Total Dust Loading (mg-hr/m3) Actual Duration (hr) Average Dust Loading (mg/m3) 1 40* 0.67 60 2 100 1.0 100 3 160 18** 8.9 4 44 2.6 17 5 90 3.1 29 6 80 7 11 The worst storm of these was storm No. 3. While it was also shown in this study that once a given dust storm terminated, there existed a 5% probability that another one would occur within 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> and a 50% probability that another one would occur within 30 days, none of the above six worst case dust storms had occurred within 30 days of each other. Most had occurred in different years during the 1953-1970 study period.

The dust loading for storm No. 3 is conservative in terms of its being considered as the worst case storm for use in plant design evaluations. As a result of the shorter storm durations of the measured August 11, 1955, January 11, 1972, and April 1972 dust storms, their time integrated dust loadings at 5-6 feet above the ground are not worse than that computed for storm No. 3 (33).

2.3.1.2.2 Design Snow Load

The American National Standards Institute (ANSI) in "Building Code Requirements for minimum Design Loads in Buildings and other Structures" (19) provides weights of 100-year return period ground level snow packs for the site region. The ANSI (Reference 2.3-19) value

• Value is less than actual dust loading as a result of less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> duration. ** The detailed investigation yielded 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> as opposed to a range of 1-16 hours given in Table 2.3-40 of 2.3.1.2.1.5.1 for the range in duration of dust storms using the same 1953-1970 data.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-15 of 20 lb/ft2 was used as the design snow load for all CGS structures.* Assuming a specific gravity of 0.1 or snow density 6.24 lb/ft3, this design value corresponds to a snow depth of 3.2 ft. The above snow load is conservative for the site as snow depth seldom exceeds six inches, and the greatest depth of 24.5 inches was recorded in February 1916. (4) The weight of the 48-hour probable maximum winter precipitation can be determined from the data presented in Table 2.3-3. Since the greatest snowfall in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was 10.2 inches (February 1993) and a record depth of approximately 12 inches lasted four days (December 1964) these depths would correspond to snow loads of 5.3 and 6.24 lb/ft2 respectively. 2.3.1.2.3 Meteorological Data Used for Evaluation of Ultimate Heat Sink The ultimate heat sink is evaluated in Section 9.2.5.

The meteorological data presented in Figure 2.3-7 and Tables 2.3-1, 2.3-5, and 2.3-7a-7h was used to evaluate the performance of the CGS spray ponds in 9.2.5 with respect to (1) maximum evaporation and drift loss and (2) minimum water cooling. In accordance with Regulatory Guide 1.27, Rev. 1 "Ultimate Heat Sink for Nuclear Power Plants", the worst one-day and 30-day periods of meteorological record which resulted in minimum heat transfer to the atmosphere were established. The worst recorded 30-day period (30-day average) of maximum difference between dry-bulb and dewpoint temperature and highest simultaneously recorded wind speeds which resulted in the maximum evaporation and drift loss were also established.

Climatological moisture and temperature data presented as a function of time of day for each month in Figure 2.3-7, and wind statistics given in Table 2.3-5 were used to establish the maximum initial pond temperature for the ultimate heat sink analyses in 9.2.5. It was determined in 9.2.5 using these meteorological data, solar radiation formulas contained in ASHRAE Handbook of Fundamentals, and techniques outlined in the John Hopkins University Report "Cooling Water Studies" (Edison Electric Institute Research Report No. 5, Project RP-49, November 1969) that the month of July contained the worst average meteorological data which resulted in the maximum initial pond temperature.

The worst day meteorological data was considered to be the given combination of meteorological parameters in a particular consecutive twenty-four hour period which resulted in the worst pond thermal performance. The following recorded episodes of extreme wet bulb temperatures experienced at the CGS and/or HMS sites were evaluated in 9.2.5 to establish the worst pond thermal performance:

1) August 7-9, 1972 at CGS and HMS, presented in Table 2.3-7a (20),

• Ice loading is included in this CGS estimate.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.3-16 2) July 4-12, 1975 at CGS, presented in Tables 2.3-7b to 2.3-7e from the onsite FSAR meteorological monitoring program,

3) August 4, 1961 at HMS, presented in Table 2.3-7f (21).

The meteorological conditions which occurred on July 10, 1975 at CGS resulted in the worst pond thermal performance as determined in 9.2.5.

The following worst month meteorological data were used in 9.2.5 to establish the second through thirtieth day worst pond thermal performance and worst 30-day drift loss and evaporation (Reference 2.3-21):

a) July 9 - August 8, 1961 at HMS, presented in Table 2.3-7a (minimum heat transfer) b) July 2 - August 1, 1960 at HMS, presented in Table 2.3-7h (maximum evaporation and drift loss)

Diurnal variations in dry bulb and wet bulb temperatures for both 30-day periods assumed that the hourly temperature variation approximated a sine wave of one cycle in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Reference 2.3-21). The average wind speeds during both 30-day periods was approximately 5.5 mph. The root mean square average of the hourly wind speed data for the 30-day mass loss period is 6.91 mph.

For conservatism in the thermal analysis, the worst day data for thermal performance was assumed to repeat in the analysis until pond temperature peaked (three days repetition). For conservatism in the mass loss analysis, an upper bound curve was fit to the drift loss data taken during spray pond testing. The drift loss value was obtained from this curve. See 9.2.5 for details.

2.3.2 LOCAL METEOROLOGY

2.3.2.1 Data Comparisons The local meteorology prior to CGS plant operation at the CGS site can be described from FSAR meteorological data procured during the period April 1, 1974 to March 31, 1976 from the permanent onsite 7-ft and 245-ft meteorological towers. Data collected from the 245-ft CGS tower had been used for the short-term (accident) and long-term (routine) diffusion estimates. Onsite meteorological data were also obtained from a temporary 23-ft tower which commenced operation in April 1972 for the purpose of determining optimum cooling tower geometric orientation for performance during high wet bulb periods. The 23-ft meteorological tower data were also used with other regional data to establish the potential impact of proposed mechanical draft cooling tower atmospheric releases in the vicinity of CGS COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-17 (Reference 2.3-22). The permanent tower data have been compared where appropriate and possible, with simultaneously recorded and historical data obtained from the Hanford Meteorological Station (HMS) for the purpose of documenting the representativeness of the two years of onsite meteorological measurements. For the months of April through August 1974, comparisons have also been made with data from the onsite temporary tower; this tower and instrumentation were dismantled in September 1974. Monthly and annual average comparisons between simultaneously recorded and historical data for all the aforementioned meteorological tower sites have indicated that agreement between the data sources is reasonably good. When comparing sources of data, it should be recognized that at any given time, significant differences can exist between the reported meteorological conditions at the CGS and HMS sites (see, for example, Table 2.3-7a). Differences in the frequencies of occurrence of various meteorological conditions at a given site can also exist from year to year or from one elevation to another elevation at a site for coincident observation times. Any discrepancies between summarized data sources can also be attributed (in addition to site separation and instrument height above ground) to differences in types and accuracies of instrumentation used and procedures considered for acquiring, processing, and analyzing raw meteorological data. Details regarding the onsite meteorological measurement program are presented in 2.3.3.

For the following data comparisons, the following definitions are used:

CGS Data obtained from the permanent 7' and 245' towers at the CGS site; summarized here for April 1, 1974 - March 31, 1976. CGS (temp). Data obtained from the temporary 23' tower at the CGS site; summarized here for April 1, 1974 - August 31, 1975.

HMS: Data obtained from the Hanford Meteorological Station; used here for April 1, 1974 - March 31, 1976.

HMS (hist): Data obtained from the Hanford meteorology tower at the Hanford Meteorological Station, used here for various periods identified in the data comparison listings. The source is AEC Research and Development Report "Climatography of the Hanford Area", June 1972, BNWL-1605.

Wind Variable: At CGS an hour of data which contains less than 15 minutes of any one direction sector; at Hanford, the same but for 20 minutes. Data obtained at the 33 foot (10 meter) elevation is presented since these data have been subsequently used in the site diffusion studies for postulated ground-level release cases.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-18 Wind Calm: At CGS, an hour of data for which the average speed is 0.22 miles per hour or less; at Hanford, average speed less than 1 mph (as decided by weather observer, corresponds to no motion of strip-chart recorded pen). Sense of Delta T: Positive values imply relative stability, negative values imply relative instability.

The first annual cycle of CGS onsite meteorological data which covered the period April 1, 1974 through March 31, 1975 has been presented in detail. Local meteorological data collected during the second annual cycle (April 1, 1975 through March 31, 1976) generally portrayed the same characteristics as indicated by comparison with the first annual cycle data. Except for the high wet bulb episode experienced at CGS during July 1975 (refer to 2.3.1.2.3 and 2.3.2.3), no monitored onsite data proved to be more severe in terms of the design and operation of CGS than those data presented in 2.3.1.2. Hence, only the second annual cycle monthly averages have been presented in Table 2.3-8a which summarizes the two years of monitored on-site data with concurrently measured and historical HMS data. Any significant differences noted between first and second annual cycle onsite data and concurrently measured CGS and HMS data are discussed in 2.3.2.1. Otherwise, conclusions stated herein for the first annual cycle of data similarly apply to the second annual cycle data. It is observed in Table 2.3-8a that any year to year differences in the summarized monthly mean meteorological data at tend to parallel the differences in the means summarized for the HMS site for corresponding months during the two year monitoring period.

Summaries of joint frequency distributions of wind direction and wind speed by atmospheric stability class and results from accident and routine diffusion estimates for both annual cycles of CGS onsite meteorological data are presented in subsequent sections.

Magnetic tape files of the two years of hourly onsite data have been transmitted to the NRC.

2.3.2.1.1 Winds

Table 2.3-8b presents monthly and annual CGS joint wind speed and direction data for the first annual cycle of monitoring. Similar data for the HMS site are given in Table 2.3-9. The CGS data presented in the above tables were collected at an elevation of 33 feet above local grade for the one year period of record whereas the HMS historical data were collected at an elevation of 50 feet above local grade during the period 1955 through 1970 (HMS is approximately 280 feet higher in elevation than the CGS site). Additional wind direction frequency statistics are presented in Table 2.3-10.

The CGS 33 ft and CGS (temp) 23 ft wind direction data given in Table 2.3-10 have similar distributions of direction frequency and show a bimodal wind direction distribution from approximately South and also Northwest. These distributions differ from that given for the HMS site where the direction distribution displays a single peak at approximately West COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-19 Northwest to Northwest. Further, the wind direction distribution at the CGS site is much more uniform around the compass than it is at the HMS site. The differences in these distributions may be attributed to the influence of terrain features, causing variability of air flow at the CGS site. This conclusion is strengthened by the observation that the CGS monthly wind frequency distributions are similar through-out the period of data acquisition. Tables 2.3-11 and 2.3-12 provide the 20 longest occurrences of wind direction persistence at CGS for an elevation of 33 feet. Table 2.3-11 shows persistence in one (22.5 degree) sector while Table 2.3-12 shows persistence within two (45 degrees) adjoining sectors; the corresponding stability class distributions and average wind speed within each stability class are also provided.

It is noted that the majority of the periods of high direction persistence at CGS are associated with unstable, neutral, and moderately stable atmospheric conditions and moderate to strong wind speeds. These represent relatively good diffusion conditions. Table 2.3-12a summarizes the longest persistences of wind direction in one and two sectors at CGS measured during the first and second annual cycles. The annual frequency and duration of episodes of high wind direction persistence at CGS depend upon the frequency and intensity of weather systems which result in regional large scale gradient flow. For example, during the first annual cycle, the longest persistence in one and two sectors lasted 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> (NW) and 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> (NW, NNW) respectively. During the second annual cycle, the longest persistence in one and two sectors lasted 33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> (NNE) and 35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br /> (N, NNE) respectively. Whereas the longest persistence in one sector during the first annual cycle lasted 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />, the duration of the first three longest persistences in one sector during the second annual cycle (33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> from NNE, 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> from SSW, and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> from NW) exceeded that longest duration.

Table 2.3-13 presents monthly frequency distributions and averages of wind speed measured at the CGS and HMS sites. Considering site separation, elevation of sensors, and instrumentation and procedural differences, the CGS wind data appear meteorologically reasonable and demonstrate consistency among data sources.

2.3.2.1.2 Moisture and Temperature

Diurnal variation and averages of dry-bulb, wet-bulb, and dew-point temperatures for the first annual cycle of monitoring at the CGS and HMS sites are given in Tables 2.3-14 to 2.3-16. Tables 2.3-17 to 2.3-19 present frequency distributions of dry-bulb, wet-bulb, and dewpoint temperatures, summarized for the first year of CGS site observations. Table 2.3-20 contains additional climatological summaries of monthly normals and extreme values of temperature and humidity measured at HMS.

Considering the 280 ft difference between the CGS and HMS sites and assuming a dry adiabatic lapse rate of 5.48°F/1000 ft, one can expect a temperature difference of about 1.5°F between the dry-bulb temperature data measured at both sites.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-20 Higher monthly average wet-bulb and dewpoint temperatures occurred at CGS since the CGS site experienced air of slightly higher moisture content than the HMS site. The higher moisture content may be attributed to Columbia River proximity and irrigation of the fields in the vicinity of CGS. This conclusion is strengthened by the fact that moisture enhancement at CGS was at a minimum for the months of January, February, and March during the first annual cycle of CGS site observations.

During the second annual cycle of monitoring, it was observed that the CGS site experienced air of essentially the same moisture content as did the HMS site. The absence of the moisture enhancement at CGS, which was noted during the first annual cycle, may be attributed to reduced evaporation from the proximate river and irrigated fields. The periodic occurrences (during the second annual cycle) of cooler dry-bulb temperatures and precipitation deficits when high dry-bulb temperatures prevailed may have resulted in reduced evaporation.

2.3.2.1.3 Monthly Precipitation

Diurnal variation of precipitation intensity at CGS and monthly total precipitation at CGS and HMS for the first annual cycle of monitoring are given in Table 2.3-21. Frequency of occurrence of precipitation intensity data from April 1974 through March 1975 at CGS are presented in Table 2.3-22. Frequency of occurrence of wind speed and direction versus precipitation intensity for the same year of data is given in Table 2.3-22a. The data show that the CGS site experienced less precipitation than did the HMS site. The difference can be attributed to site separation and the incidence of precipitation falling in the form of showers of quite limited spatial extent. The precipitation deficit at CGS may also result from a rain shadow effect from Rattlesnake Mountain. A precipitation gradient is known to exist along the slope of this terrain feature.

2.3.2.1.4 Fog

Fog data are unavailable for the site. Although fog has been observed in every month of the year at HMS, it is essentially a seasonal phenomenon with 95 percent of it observed during the months of November through February. Inclusion of March and October fog would increase this percentage to 99.7. Tables 2.3-23 and 24 summarize the duration and persistence statistics for fog occurrences at HMS. Because of the relative proximity of the site to the Columbia River, it is expected that the frequency of occurrence, intensity and duration of fog would be somewhat greater than these data indicate (refer also to 2.3.2.1.5).

Most fog in the Hanford region is of the radiation type and hence occurs mostly in conjunction with light wind, inversion or stable atmospheric conditions. The occurrence of fog at the site can therefore be considered as one visual indicator of poor atmospheric diffusion conditions. Advection and frontal fogs occur occasionally at both HMS and the Tri-City stations of Richland and Pasco. In addition, at Richland and Pasco, there are occasional occurrences of COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-21 steam fog from the Columbia River. These are not usually deep and many would be classified as ground fog.

Statistics on fog persistence are limited to those at HMS. Although most dense (visibility 1/4 mile or less) fogs do not last longer than 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, a few run for much longer periods as shown in Table 2.3-23. After a period of fog, there frequently follows a period of atmospheric stagnation with a low stratus overcast and light winds. Such conditions may persist for many days.

2.3.2.1.5 Stability Summaries For the purposes of comparison, the t (temperature difference) and sigma theta (standard deviation of the horizontal wind direction fluctuations) stability classifications which are used in diffusion studies at Hanford are given below with the t "Pasquill" and sigma theta classes identified in NRC Regulatory Guide 1.23: REGULATORY GUIDE 1.23 Pasquill Class t/Z (F/200 FT) Sigma* Theta Extremely unstable A Less than -2.1 25.0 Moderately unstable B -2.1 to -1.9 20.0 Slightly unstable C -1.9 to -1.6 15.0 Neutral D -1.6 to -0.6 10.0 Slightly stable E -0.6 to 1.6 5.0 Moderately stable F 1.6 to 4.4 2.5 Extremely stable G greater than 4.4 1.7 HANFORD RESERVATION CLASSIFICATION Pasquill Class t/Z (F/200 FT) Sigma Theta Groupings** (Degrees) Very unstable Less than -2.5 greater than 22.5 Unstable -2.5 to -1.5 25.5 to 17.5 17.5 to 12.5

• Period of 15 minutes to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. ** Note that these sigma theta groupings do not necessarily correspond to any particular Hanford Stability Class on the left, i.e., there can be a maximum of 35 group combinations of t/Z and sigma theta although some combinations are unlikely to occur.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-22 Neutral -1.5 to 0.5 12.5 to 7.5 7.5 to 3.75 Moderately Stable 0.5 to 3.5 3.75 to 2.1 Very Stable greater than 3.5 less than 2.1 Joint frequency distributions of wind speed and direction by atmospheric stability class (temperature difference and sigma theta combinations) for the first and second annual cycles of monitoring are presented in Section 2.3.3. Percent frequency of occurrence of stability (t distribution) at CGS and HMS are given in Table 2.3-25. Although the heights over which t was measured are similar for both sites, it is observed in Table 2.3-25 that CGS experiences air of greater thermal stability than HMS. This discrepancy between site stabilities may be accounted for because of terrain differences. The CGS site serves as a drainage basin for relatively cool air (especially at night), resulting in strong thermal low-level stratification and the formation of persistent temperature inversions. This conclusion is strengthened by the observation that the difference between the sites is much more pronounced during July, August, September and October than during all other months. It is during these months that pooling of relatively cool air is at a maximum due, partly, to minimum cloudiness and therefore, enhanced nocturnal cooling occurs at the ground. It is noted in Table 2.3-25 that the percent frequencies of stability types for both annual cycles of monitoring at CGS are very similar. Frequencies of occurrence of t and sigma theta versus time of day for the first year of onsite meteorological measurements are given in Table 2.3-26 and 2.3-27. Although frequency of occurrence and duration of inversion conditions were not analyzed for the site, stagnation and inversion information contained in 2.3.1.2.1.5 and 2.3.2.1.5 for HMS should be representative for the site (except for the fact that the above data indicates that CGS experiences a greater frequency of surface-based inversions than does HMS). Figure 2.3-8 shows probabilities of inversion persistence at HMS from 1952-1969 (2). 2.3.2.2 Potential Influence of the Plant and Its Facilities on Local Meteorology The shapes and sizes of the buildings erected on the plant site will produce a disturbed air flow which alters the initial distribution pattern and diffusion rates of plant release airborne contaminants. In the diffusion calculations this effect is considered.

Electrical power generation by steam turbines requires dissipation of large quantities of low grade thermal energy. Waste heat produced from the operation of CGS is dissipated by means of six circular mechanical draft cooling towers. These evaporative cooling towers release waste heat directly to the atmosphere in the form of sensible and latent heat. An extended visible plume consisting of liquid water droplets can occur principally during the winter months when periods of cold weather and high relative humidity prevail. Fogging is defined as occurring if visible plumes intersect the ground, buildings, or other elevated structures.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-23 Fog occurs naturally in this region, and any cooling tower fog is an extension of the naturally occurring phenomenon. When air temperatures of 0°C or lower prevail, the additional potential exists for icing on these surfaces. At times, small cumulus clouds could form above or remote from the plant, depending on the atmospheric temperature and moisture conditions in the first several thousand feet above the cooling towers. No significant environmental or atmospheric impacts arising from CGS cooling tower operation have been observed or are foreseen based on dispersion meteorological studies performed by Battelle Northwest Laboratories (Reference 2.3-22). Details covering potential environmental impacts arising from CGS cooling tower operation are given in the CGS Environmental Report.

2.3.2.3 Local Meteorological Conditions for Design and Operating Bases The regional long term meteorological conditions provided in Section 2.3.1.2 are applicable for use in establishing the plant design and station operating bases. Except for the high wet bulb episode experienced at CGS during July 1975 (refer to 2.3.1.2.3), none of the local short term meteorological data presented in 2.3.2.1 proved to be more severe in terms of the design and operation of CGS than those presented in 2.3.1.2. Data collected since January 1, 1984 form the revised long-term design and operating basis for dispersion calculation. 2.3.2.4 Topographic Description As shown in Figures 2.1-1 and 2.1-2, the plant is located at a grade elevation of 441 feet MSL in a basin area formed by the Saddle Mountains to the northwest, bluffs and hills rising to about 900 feet MSL to the north and east, the Horse Heaven Hills to the south and the Rattlesnake Hills and Yakima, Umtanum and Manastach ridges to the west. Topographic cross-sections plotted out to 10 kilometers by sector from the plant are given in Figure 2.3-9. Except for the cliffs toward the east across the Columbia River, the region within this circumference is basically flat and featureless and slopes gradually toward the Columbia River. Additional details regarding the regional topography and geology are given in 2.5. The effects of regional topography on local meteorology are discussed in 2.3.1.1, 2.3.2.1.1 and 2.3.2.1.5. The need to consider plume height relative to land elevations has been obviated by the assumption of a ground-level release for the accident and routine station release cases which are presented in 2.3.4 and 2.3.5. 2.3.3 ONSITE METEOROLOGICAL MEASUREMENT PROGRAM The permanent onsite meteorological data collection system in use since January 23, 1974 consisted of a 240 ft main tower, an auxiliary seven ft instrument mast, sensors with associated COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000 LDCN-99-000 2.3-24 electronics and recording devices, and a meteorological shelter. A 23 ft onsite temporary tower was also used during the period April 1, 1972 through August 31, 1974. The Battelle Memorial Institute, Pacific Northwest Laboratories, had been conducting a continuing two year program of acquisition, processing, and analysis of meteorological data for Energy Northwest Columbia Generating Station in a contractual arrangement with Burns and Roe, Inc.

The first and second annual cycles of reliable meteorological data were collected during the periods April 1, 1974 through March 31, 1975 and April 1, 1975 through March 31, 1976, respectively. The accuracy of these data had been established primarily through calibrations conducted at quarterly intervals as required through a formal program of quality assurance. The data were examined for meteorological reasonableness, after corrections were applied per the calibration Reports, through computer edit programs. No data were found to be unreasonable. The annual summaries were compared with the monthly summaries and all were found to be consistent. The computer summarization programs (identical for monthly and annual purposes) were tested at quarterly intervals by application to dummy data per the quality assurance program. (23) The computer calculation programs for x/Q were similarly tested. Comparisons between CGS meteorological data and concurrently measured and historical HMS data have been presented in 2.3.2.1.

2.3.3.1 Permanent Onsite Meteorological Tower and Instrumentation Characteristics The meteorological tower, which is located approximately 2,500 feet west of the CGS plant site with its base at 455' MSL, consists of a 240 ft high primary tower with a five ft mast extending above it. The primary tower is triangular in shape and of open lattice construction to minimize tower interference with meteorological measurements. Wind and temperature measurements were made at the top of the mast and at the 33 ft level. The dewpoint temperature was measured at the 33 ft level. At the lower level the instruments were mounted on an eight ft horizontal boom extending southwest of the tower. Wind and temperature measurements were also made at the top of a seven ft mast which was located approximately 80 feet southwest of the 245 ft tower.

Wind speed measurements were made using conventional cup anemometers (Climet Instruments, Model 011-1 Wind Speed Transmitter) which have a response threshold of about 0.6 mph and a distance constant of less than five feet. Over a calibrated range of 0.6 to 90 mph the accuracy of these instruments is +/- 1% or 0.15 mph (whichever is greater). Data collection on the 240 foot and seven foot towers was terminated on June 1, 1976 subsequent to the collection of two years of reliable tower data ending March 31, 1976, required for the CGS FSAR. Data collection on the Primary and backup towers began on July 1, 1984.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-25 Wind direction measurements were made using lightweight vanes (Climet Instruments, Model 012-10 Wind Direction Transmitter).

The response threshold of these vanes is about 0.75 mph, and their damping ratio and distance constant are approximately 0.4 and 3.3 feet, respectively. Dual potentiometers in the Wind Direction Transmitter produce an electrical signal covering 540° in azimuth with an accuracy of +/-3°. In addition, electronics had been included to provide signals which were proportional to the standard deviation of the wind direction fluctuations at each level.

Temperature instrumentation had been installed to provide measurements of both the ambient air temperature at the 245, 33 and 7 ft levels, as well as the temperature differences between these levels. The ambient air temperature and the temperature difference measurement systems were independent of each other to provide for reliability. Atmospheric stability delta - T classes were determined solely on the basis of the data from the electronic differencing bridge and not by subtracting the ambient air temperature measurements. All temperature measurements for both systems were made in aspirated radiation shields (Climet Instruments Model 016-1 or -2) using platinum resistance temperature detectors (Rosemount Engineering Co., Model 104 MB6ABCA). These instruments provided an ambient temperature range from

-30°F to +/-130°F and a temperature difference range of +/-15°F. The accuracy of the instruments is +/-.09°F in the measurement of temperatures and +/-0.18°F in the measurement of temperature differences.

The dewpoint temperature was measured at the 33 ft level of the tower using a lithium chloride dewpoint sensor (Climet Instruments, Model 015-12) housed in an aspirated radiation shield (Climet Instruments Model 016-2). Precipitation was measured at ground level using a tipping bucket rain gage (Meteorology Research Incorporated, Model 302) located about 40 feet west of the main tower. This instrument is accurate to within 1% at rainfall rates up to 3 in./hr and has a resolution of 0.01 in. The instrument building provided a semi-controlled environment near the tower to house the instrument electronics and record the data. Analog strip chart and digital magnetic tape recorders were used to provide redundant data recording capability. The primary data recording system was a seven-track digital magnetic tape recorder (Kennedy, Model 1600) which used 1/2 inch tape. Logarithmically time-averaged wind speed, wind direction, temperature, temperature difference and dewpoint temperature signals were recorded at five minute intervals. The time constant of the averaging process was five to ten minutes. The standard deviation of wind direction fluctuations during the preceding five minutes at each level and the total precipitation were recorded along with the wind and temperature information. All data, except the wind direction standard deviations, were also recorded on strip charts which provided a backup data record to enhance data retrievability. In addition, since the strip charts contained an essentially instantaneous record of the signal from each instrument, they provided a rapid means of identifying instrument malfunctions and were useful in system calibration. These strip charts and magnetic tapes were changed weekly.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-01-072 2.3-26 In summary, the total system accuracies for the measured meteorological parameters meet or exceed the following specifications:

air temperature +/-0.5°C temperature difference +/-0.2°C

humidity (dew point) +/-2.8°C wind speed 0.5 mph from 0.5 to 5 mph, +/-10% of reading above 5 mph per RG 1.97, Rev. 3. wind direction +/-5° These are verified by the end-to-end calibrations. Data recovery was better than 90%.

2.3.3.2 Quality Assurance Program To ensure the quality of the meteorological data collected by the monitoring system, an extensive quality assurance program had been instituted. This program covered all phases of meteorological monitoring from the initial instrument acquisition through the analysis of data. Periodic checks and calibration of the instrument systems and individual components had been instituted. These periodic checks ranged from daily inspection of the strip charts to semiannual calibration of the complete system. All checks, calibrations and maintenance were fully documented, including traceability of test and calibration equipment to the National Bureau of Standards where necessary. Once collected, the data were protected from loss to the maximum extent possible; the digital tapes were examined to identify possible instrumentation malfunctions; and the data were then copied onto two master tapes. The original weekly tape and one master tape were stored in vaults for safekeeping while the second master tape was used in the preparation of data summaries. Finally, to ensure proper operation of computer hardware and software, all computer programs used to summarize or analyze the data were checked quarterly using a standard data input. The computer output from these tests was then saved to document computer operation.

The various phases of the quality assurance program pertaining to the two years of permanent onsite meteorological monitoring and data processing are discussed in the following subsections.

2.3.3.2.1 Data Recovery During April 1, 1974 - March 31, 1976 The meteorological data acquisition system was put into operation during January 1974. Outages in the digital system precluded an initiation date for the acquisition of reliable data prior to April 1, 1974 because the processing of an inordinate amount of data from strip charts COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-27 would have been required. The data utilized in the production of the monthly and annual summaries have been obtained exclusively with the primary data recording equipment (magnetic tape digital system) since August 1, 1974. Recourse to data recorded on strip charts was required at times prior to August 1974 to assure, as viewed at the time, a recovery rate of 90% representative data as required by Nuclear Regulatory Guide 1.23. The percentages of monthly data read from strip charts is listed below:

April 1974 - 23.3%

May 1974 - 8.3%

June 1974 - 49.5% (W/S 33' - 59.1%)

July 1974 - 1.6%

From routine and anticipated causes (system maintenance and calibration) modest data losses were experienced on the order of 2% and 1.2% for the first and second annual cycles of onsite data collection respectively. A comparable amount, for some of the meteorological quantities, was caused by circumstances beyond Battelle's control (power outages, delay in receipt of spare parts, etc.). The percentages of missing annual data for various meteorological quantities are listed below:

April 1, 1974- March 31, 1975 April 1, 1975 March 31, 1976 Wind Speed 33' 4.0% 2.7%

Wind Direction 33' 4.0% 1.5%

Dry Bulb Temperature 33' 2.5% 1.2%

Wet Bulb, Dewpoint Temperature 33' 2.7% 1.2% Differential Temperature 33' - 245' 3.1% 1.5%

These percentages are representative of missing data for all meteorological quantities except precipitation. During the first annual cycle of monitoring, data recovery for precipitation was 100%. Precipitation data recovery was complete during the second annual cycle of monitoring, except possibly during December 1975 when a sand plug was discovered in the rain gauge funnel. As a result, it was estimated that less than 0.1 inch of precipitation was not recorded during that month. For the first annual cycle of monitoring, the data recovery rate was 96% or better for all meteorological quantities; this rata was 97% or better during the second annual cycle of monitoring.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-28 2.3.3.2.2 Maintenance and Calibration Assurance of quality data rests primarily with the calibrations performed at quarterly intervals and reported for July and October 1974; January, April, July and October 1975; and January and April 1976.

All evidence to date obtained through formal calibrations and routine daily and weekly inspection had demonstrated that the meteorological system remained electronically stable in terms of obtaining data of sufficient quality to meet the requirements in Regulatory Guide 1.23. The calibration corrections required are tabulated in the response to NRC question 6.4 on the FER. The calibrations established any system inaccuracies by comparisons to standards. These inaccuracies were corrected by appropriately adjusting the data at the data processing stage as opposed to adjusting the system electronics. The calibrations before and after each calibration period were used to determine if corrections were required to account for drift or if offset had occurred. No drift corrections were required. The offsets were discussed in the FER response. For corrections that were not constant throughout the range of a given parameter, a calibration table or curve was used to correct the data. Calibration corrections were applied as part of the computer programs used to edit and translate the data from the original raw-data tapes to a master file of hourly values.

2.3.3.2.3 Data Processing and Analysis

For the two years (1974-1976) of onsite FSAR meteorological monitoring at CGS, all data (magnetic tape and strip chart where required) were run through computer edit programs. No data were found to be unreasonable except for known causes as documented in Nonconformance Reports. Data corrections, per the Calibration Reports, were applied in the computer programs. Summarization of data has been accomplished only at such times as calibration information was available to bracket in time the acquired data.

The data for each hour is represented by an average of the data for the last 30 minutes in the hour. The averaging period of 30 minutes was selected for consistency with 1) the data used to formulate the Hanford Diffusion Model used for routine and accident dose calculations, 2) the recommendations in Regulatory Guide 1.23, and 3) computational economy. The only exception was wind direction which was averaged over one-hour to facilitate the formulation of wind direction persistence summaries. One thirty-minute period per hour is considered adequate for climatological summaries consisting of averages of many hours. In addition, x/Qs based on thirty-minute averages will be conservative for estimates of the one-hour averages. All data products were based on these "hourly" averages.

Wet bulb from the permanent tower was obtained from standard psychrometric formulas presented in the Smithsonian Meteorological Tables, 1971 issue.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-29 The above descriptions relate to data collected and used in FSAR submittals through Amendment #36. Data collection and processing since July 1, 1983 is described in 2.3.3.2.4. The Kennedy Tape Recorder has been replaced with a floppy disk recorder for increased reliability.

In several of the monthly summary reports, the computer programs as applied to dummy data have been compiled as called for in the Quality Assurance Manual (Reference 2.3-23) for the purpose of documenting proper programming and proper computer performance.

These computer computations have been verified with hand calculations made with the dummy data. The computational programs for x/Q were similarly tested.

2.3.3.2.4 Meteorological Monitoring Program During Plant Operation The meteorological tower, which is located approximately 2500 ft west of the CGS plant site with its base at 455 ft msl consists of a 240-ft high primary tower with a 5-ft mast extending above it. This tower is triangular in shape and of open lattice construction to minimize tower interference with meteorological measurements. Wind and temperature measurements are made at the top of the mast and at the 33-ft elevation by duplicate sets of instruments. One set of instruments is the primary measurement system and the other set constitutes the backup instrumentation. The lower elevation wind speed/direction instruments are mounted on a horizontal boom, extending southwest of the tower.

Wind speed and wind direction measurements are made with a single instrument package that combines a wind speed propeller on the leading (upwind) end of the instrument and a wind direction vane, or tail, on the opposite end. Wind speed measurement range is 0.5 to 90 mph with a threshold sensitivity of about 1 mph. The wind direction measurements are made by the wind passing over the wind vane portion of the instrument. In addition, electronic modules process the data from these instruments and provide output data which is proportional to the standard deviation of the wind direction fluctuations over 15 minutes.

Temperature instrumentation provides measurements of the ambient air temperature at the 245 and 33-ft elevations. Temperature measurements are made in aspirated radiation shields using platinum RTDs. These instruments provide an ambient temperature range from -50°F to +150°F. Each set of RTDs (one from 33 ft level and one from 245 ft level) are calibrated together in the same temperature bath and electronic modules process the data from these instruments to provide a temperature difference range of +/-15°F.

The relative humidity is measured at the 33-ft elevation of the tower using an intercap sensor with a range of 0 to 100% RH housed in an aspirated radiation shield. Precipitation is measured at ground level using a tipping bucket rain gauge located about 40-ft west of the main tower. The barometric pressure is measured by a pressure transmitter located inside the COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 LDCN-10-001 2.3-30 Met Tower building. The Met Tower building provides a semi-controlled environment near the tower to house the instrument electronics. Signal conditioning is provided in the Met Tower by two GE FANUC PLC controllers, one for the primary instrumentation and one for the backup instrumentation. The primary controller feeds data to the Supervisory System and the PDIS via the LAN. The backup controller feeds data only to the PDIS via the LAN. Information will be available to all locations for both the primary and backup instruments on the LAN. The backup system does not provide data for the barometric pressure or the rain gauge. Wind speed, wind direction, temperature, temperature difference and relative humidity signals are averaged by the controllers using a 15 minute time constant device before sending the information to the control room. In the control room are three recorders which record 245-ft and 33-ft wind speed, wind direction, delta temperature, and ambient temperature at 33-ft elevation. The system accuracies for the measured meteorological parameters are demonstrated to meet or exceed the following specifications by performance of instrument loop calibrations:

Air temperature +/-0.5°C (+/-0.9°F) Temperature difference +/-0.2°C (+/-0.36°F)

Humidity (dew point) +/-2.8°C (+/-5.0°F)

Wind speed +/-0.50 mph from 0.5 to 5 mph, +/-10% of reading above 5 mph per RG 1.97, Rev. 3. Wind direction +/-5.0° This data is processed by the Supervisory System which forms the primary communication vehicle for the meteorological system. The supervisory system located at the meteorological tower building and the control room digitizes and multiplexes the data to the control room where it is restored to analog format and sent to recorders and the PPCRS, as required, on a real-time basis. The data input to the supervisory system is 15-minute average analog values. Longer period averages will also be computed for trend analysis and report generation. These data are routed to satisfy display and processing requirements of the onsite technical support centers (TSC) and the emergency operations facility (EOF). The primary meteorological tower data is stored by the plant data acquisition system. Instrument calibrations and maintenance procedures meet the data recovery and system accuracy requirements of Regulatory Guide 1.23 except as noted above.

The Emergency Dose Projection system provides redundant data communication paths with remote access and redundant power sources as required for routine or emergency preparedness support. The near real time access to both the primary and backup meteorology systems, via the supervisory system or the LAN, thus satisfies the emergency preparedness requirements of Regulatory Guide 1.23.

These two systems are designed to meet or exceed data unavailability statements of Regulatory Guide 1.23. If offsite meteorological data is needed, data can be obtained from a network of meteorological towers located on the Hanford Site using methods described in the Emergency COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-31 Preparedness Plan. The accuracy, calibration, and reliability of all data not directly controllable by Energy Northwest is determined by the private/governmental controlling agency. 2.3.3.3 Other Meteorological Measurement Programs Considered for the Data Comparisons 2.3.3.3.1 CGS Temporary Tower A temporary 23-ft onsite tower was used during the period April 1, 1972, through August 31, 1974, to obtain data input for CGS environmental studies and to provide a comparative overlap with the initially measured permanent tower data.

The temporary tower was located in the vicinity of the permanent towers with its base at approximately 448 ft msl. Wind data from the temporary tower were obtained at the 23-ft level while temperature data were acquired at the 3-ft level. Wet bulb data from the temporary tower were established from techniques and data contained in the U.S. Department of Commerce, Weather Bureau Office Document, Relative Humidity and Dewpoint Table. As a special quality assurance program was not initiated for the temporary tower installation, it is not possible to assert that this tower's data complied with the requirements contained in Regulatory Guide 1.23. 2.3.3.3.2 Hanford Meteorological Station The Hanford Site maintains a network of meteorological towers, which can be accessed for data by telephone or electronic form. 2.3.3.4 Joint Stability - Wind Frequency Summaries Joint frequencies of wind direction and wind speed by atmospheric stability class (sigma theta by t classes), collected at the 33 ft level of the permanent tower during the period from January 1, 1984 to December 31, 1989 are presented in Table 2.3-28A. The sigma theta/t stability classification approach (see 2.3.2.1.5) has been used by Battelle to maintain consistency with the longer term HMS data to which existing data is compared and to satisfy the data requirements of the Hanford Diffusion Model (HDM) the HDM requires joint measurements of sigma theta and t for the more restrictive stable diffusion cases and utilizes the Sutton method with locally derived parameters for neutral and unstable cases (21). The HDM differs from the standard NRC diffusion models as a result of the incorporation of empirically derived diffusion coefficients based on historical experiments performed at Hanford. As a result of the extensive experimental data that were used in deriving the HDM, itis appropriate to consider this model when performing diffusion analysis at the Hanford Reservation.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-32 In 2.3.2.1, comparisons between measured CGS onsite data and simultaneously recorded and historical HMS data illustrated the following differences between sites:

a. The CGS site experienced a small air moisture enhancement during the first annual cycle of monitoring. During the second annual cycle, the CGS site experienced air of essentially the same moisture content as did the HMS site.

b. The CGS site experiences a biomodal wind direction distribution from approximately south and also northwest. At HMS, the direction distribution displays a single peak at approximately west northwest to northwest.

c. The CGS site experiences air of greater thermal stability than does HMS.

Reasons for these differences were given in 2.3.2.1.

2.3.4 SHORT TERM DIFFUSION ESTIMATES 2.3.4.1 Objective In this section brief descriptions of the sources, the receptors, and the methodologies used to calculate the air dispersion factors, /Q, for the Exclusion Area Boundary (EAB), the Low Population Zone (LPZ), and the control room are presented. 2.3.4.2 Exclusion Area Boundary The EAB is located at a distance of 1950 m (approximately 1.2 miles) from the site. The /Qs were calculated using site-specific meteorological data from 1996 to 1999, (Reference 2.3-38). The Joint Frequency Distributions (JFDs), Table 2.3-28, were used as an input to the computer code PAVAN, (Reference 2.3-25) and the /Q results are presented in Table 2.3-37. The /Q values at the EAB are calculated for each hour of data. The cumulative probability distribution of these values are determined for each of the wind direction sectors. Two distributions are calculated, Pasquill-Gifford (P-G) with meander sigmas and desert sigmas (includes meander). The distributions represent the annual probabilities that the given /Q values will be exceeded in each wind direction sector at the exclusion area distance. Table 2.3-34 incorporates the P-G meander effect and Table 2.3-33 has desert sigmas. From each of the sixteen sector distributions, the /Q value which is exceeded 0.5 percent of the total time was selected. This value was selected based on the percentage of total observations rather than the percentage of observations that the wind direction is within the appropriate sector. These 16 sector /Q values are given in Tables 2.3-33 through 2.3-34. The highest of these sixteen values is defined as the maximum sector /Q value.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-33 2.3.4.3 Low Population Zone The LPZ is located at a distance of 4827 m (approximately 3 miles) from the site. The /Qs were calculated using site specific meteorological data from 1996 to 1999, (Reference 2.3-38), the JFDs, Table 2.3-28, were used as an input to the computer code PAVAN, (Reference 2.3-25) and the /Q results are presented in Table 2.3-37. The sector /Q values at the LPZ have been estimated for various fixed time intervals of a 30-day period. These time intervals are 0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and 1 - 30 days. The estimates for these time periods are made by interpolation on a log-log plot of the two-hour and annual average values as described by Regulatory Guide 1.145. These interpolations are carried out for the value which is exceeded 5 percent of the time, and 0.5 percent of the time. The interpolations are displayed in Tables 2.3-35 (Desert) through 2.3-36 (P-G, meander). For these interpolations the 2-hour values are assumed equivalent to the 1-hour values. These depictions and interpolation schemes are identical to those specified in Regulatory Guide 1.145. 2.3.4.4 Control Room The control room air dispersion factors /Q were calculated using the 1996 to 1999 site-specific hourly meteorological data, (Reference 2.3-37). The meteorological data and the input parameters were used as input to the computer code ARCON96, (Reference 2.3-36), and the /Q results are presented in Table 2.3-37. 2.3.4.5 Description of Sources There are 4 sources at CGS that could release radioactivity to the environment following an accident. These sources are described below: a. The roofline source is a vent (short stack) on top of the reactor building at a height of 70 m (approximately 229 ft) above the ground through which routine releases take place. Following an accident, the exhaust air from the reactor building passes through the SGT filtration system before exiting through the roofline stack. This source is treated as a ground level point source in the /Q calculations. b. The reactor building railroad bay doors are located at the ground level on the eastside wall of the reactor building. It is assumed that some leakage to the environment takes place through these doors. c. The reactor building walls from the 606 ft level to the 670 ft level (top of reactor building) are made of metal sheets and therefore they are assumed to be COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-34 a diffuse source capable of leaking radioactive materials to the atmosphere, this source is also treated as a ground level release source. d. The Turbine Building Exhaust System (TBES) is a set of four circular vents (short stacks) located on top of the radwaste building roof. Air from the turbine building is exhausted to the atmosphere through these 4 vents. 2.3.4.6 Control Room Intakes There are three intakes at CGS which draw air into the control room during normal operation as well as post accident. A description of these intakes is given below: a. Local intake point: The local intake point is a vent located on the west side of the radwaste building wall at an elevation of 527 ft (26.5 m above the ground). b. Remote intakes: there are two ground level remote intake points which are approximately 180 degrees from each other. One remote intake is located to the north-west side of the turbine building and is labeled remote-1, the other is located to the south-east side of the reactor building and is labeled remote-2. 2.3.4.7 Calculations Formulations for calculating short term /Q values have been developed for licensing of nuclear power plants and are described in Regulatory Guide 1.145, (Reference 2.3-26) "Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants." For the CGS configuration, it is assumed that accidental releases are made at ground level. This assumption provides a conservative estimate of downwind /Q values. NRC code PAVAN (Reference 2.3-25) is used to produce dispersion estimates with the desert sigma option enabled.

Based on the guidance given in Regulatory Guide 1.145 the /Q values are calculated using three separate equations. The particular equation which is used depends upon the existing meteorological conditions. The equations are: (1) )2A / yz(U1Q / 10+= (2) )yz3(U1Q / 10= (3) yzU1Q / 10=

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-35 Where /Q is relative concentration (sec/m3) is 3.14159 U10 is the wind speed at the 10 meter level (m/sec) y is the horizontal desert diffusion parameter (m) determined from downwind distance and stability category. z is the vertical desert diffusion parameter (m) determined from downwind distance and stability category. Y represents plume meander and building wake effects (m) and is a function of stability category, wind speed, and downwind distance. A is the smallest vertical plane cross-sectional area of the reactor building (m2). During neutral or stable atmospheric stability conditions, the results of all three equations are used to determine dosages. The values from Equations (1) and (2) are compared and the larger is selected. This value is compared with that computed in Equation 3 and the lower value is selected as the appropriate /Q value. During all other meteorological conditions (unstable and/or wind speeds of 6 m/sec or more), only equations (1) and (2) are considered. The appropriate /Q value is the larger of the two. Values of Y and z, the horizontal and vertical diffusion parameters are taken from Regulatory Guide 1.145 for the applicable stability category and downwind distance. For extremely stable condition (Category G), the following equations are applied: Y(G) = 2/3 Y(F) z(G) = 3/5 z(F) 2.3.5 LONG-TERM (ROUTINE) DIFFUSION ESTIMATES

2.3.5.1 Objectives The joint wind direction and wind speed by atmospheric stability class data presented in Subsection 2.3.3 was used to assess annual average normalized concentrations, X/Q, for 16 radial sectors extending from the site boundary to a distance of 50 miles from the source. Tables 2.3-38 provides X/Q and D/Q concentrations for a mix mode release assuming desert COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-36 sigmas no decay, no plume depletion, recirculation, and a building wake (building height - 70.4 m). D/Q is normalized deposition.

2.3.5.2 Calculations The calculational techniques used are consistent with the guidance provided in Regulatory Guide 1.111 "Methods for Estimating Atmospheric Transport and Dispersions of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors". The joint frequency data presented in Subsection 2.3.3 were used in conjunction with the following equation to obtain X/Q values at appropriate downwind distance in each of the 16 sectors. ()()()(,).exp()./xQfhxRxxuxxDijijezjfxizj=+2032205222212 Where: (,)xQ = average effluent concentration in Ci/m3 normalized by source release rate (Ci/sec) at distance x and direction k.

x = downwind distance from release point.

ui = midpoint value of ith wind speed class.

he = effective plume height. zj(x) = vertical standard desert deviation of effluent spread at distance x for the jth stability class.

Rfx = factor to account for air recirculation and stagnation.

fijk = joint probability of the ith wind speed class, jth stability, class, and kth wind direction. = 3.1416 D = maximum building height of adjacent buildings (D = 70.4 m)

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-37 The building wake correction Equation 1 must not reduce the X/Q estimate by more than a factor of 3 or ()2220512312xjxDzjx()./()/+ Equation 1 assumes a long-term continuous release whose effluent is distributed evenly across a 22.5° sector. The release was assumed to be ground level (i.e., he = 0 in Equation 1). Computer code X0QD0Q, with the Desert sigma option enabled described in NUREG-0324, was used to make two sets of calculations. The nearest residences where maximum individual doses with single sector contributions occur at distances of 4.0 miles ENE (Ringold) and 4.2 miles ESE (Taylor Flats) of CGS. The annual average /Q values for these locations are calculated in Table 2.3-38c, 38f and 39c, 39f. The Columbia bluffs rise to an elevation of 878 ft just south of Taylor Flat. If it is considered that the low level sigma Z is less than 100 m out to 6 km for the P-G stability classes D-G, which are prevalent most of the winters and that low-level winds deflect either north or south near the bluffs (Reference 2.3-2), it is estimated that the total doses for these locations may be once again as large due to contributions of favorably oriented wind sectors. The total dose in the channeling area of the Columbia River should include contributions from four other sectors with deflected winds and other channeling effects. The individual doses in that location could be twice as large as for the single sector, constant wind computations. The drift from the cooling towers should remove some of the effluent and deposit it on the site with the salts and counteract the bluff effect. The mechanical draft cooling towers should entrain part of the effluent, lift it with the plume and thus also make the /Q values over-predictive. Reasons for these differences were given in Subsection 2.3.2.1.

The results reported by Start and Wendell ("Regional Effluent Dispersion Calculation Considering spatial and Temporal Meteorological Variation," Preprint volume, Symposium on Atmospheric Diffusion and Air Pollution of the American Meteorological Society, September 9-13, 1974) indicate an average value at these distances of about 0.65 and a minimum single point value of about 1.75. If these factors are multiplied by the fraction of plume remaining at the distances in question, about 0.75, to account for the conservatism of the nondepleting model used to arrive at the dose estimates provided in 5.2 of the CGS Environmental Report, it is found that the most critical dose of 9.2 mrem to a child's thyroid (at Taylor Flat) is still within the 10 CFR Part 50 Appendix I design objective limit of 15 mrem. For example, 1.75 x 0.75 x 9.2 = 12.1 mrem. This value would still be conservative because the above recirculation factors do not account for the existence of a bluff line immediately downwind of Taylor Flat which will under the more stable conditions turn the plume before it reaches Taylor Flat. This effect would further reduce the effective recirculation factor.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-38 At the nearest point of the nearest population center, about 9 miles, the average recirculation factor value from Start and Wendell, 1974, appears to be about 0.3 with the maximum single point value about 0.8. In addition to this effect, the effect of topographic channeling has been evaluated by conservatively hypothesizing that under stable conditions that winds blowing anywhere from the east to west (through north) sector might end up in the four sectors containing the majority of the population, SE through WSW (Pasco through Benton City). Including the effects due to channeling results in an estimated maximum factor of approximately 1.6. Applying the factors for recirculation and fraction of plume remaining after deposition results in a maximum effective factor of (1.6 x 0.8 x 0.67 = 0.86) less than one.

It therefore appears reasonable to conclude that the methodology employed to estimate doses is sufficiently conservative for the subject site to ensure that the doses to individuals and the general population have not been substantially underestimated due to the inherent assumptions.

2.

3.6 REFERENCES

2.3-1 Baker, D. A., Diffusion Climatology on the 100-N Area, Hanford Washington, Douglas United Nuclear Company, DUN-7841, Richland, Washington, January 1972.

2.3-2 Stone, W. A., et al. Climatography of the Hanford Area, Battelle Pacific Northwest Laboratories, BNWL-1605, Richland, Washington, June 1972.

2.3-3 Stone, W. A. Meteorological Instrumentation of the Hanford Area, General Electric, Hanford Atomic Products Operation, HW-62455, Richland, Washington, March 1964.

2.3-4 Phillips, E., Tri-City Area, Kennewick-Pasco-Richland, Washington Narrative Climatological Summary, Climatography of the United States No. 20-45, U.S. Department of Commerce and Economic Development.

2.3-5 Federal Meteorological Handbook No. 1, Surface Observations, U.S. Government Printing Office, January 1970. 2.3-6 Fujita, T., Estimate of Maximum Wind Speed of Tornadoes in Three Northwestern States, SMRP Research Paper No. 92, University of Chicago, December 1970. 2.3-7 Jaech, J. L., Statistical Analysis of Tornado Data for the Three Northwestern States, Jersey Nuclear Company, Richland, Washington, December 1970.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-39 2.3-8 Daubek, H. G., Tornado History and a Discussion of the Tornado Warning System, Battelle Memorial Institute, Pacific Northwest Laboratories Report to Jersey Nuclear Company, Richland, Washington, December 1970. 2.3-9 Thom, H. C. S., "New Distribution of Extreme Winds in the United States," Journal for the Structural Division, ASCE, ST-7, July 1968, pp 1787-1801.

2.3-10 ASCE Task Committee Report, Wind Forces on Structures, Paper No. 3269, Vol. 126, 1961.

2.3-11 Larson, L. B., Air Pollution Potential Over Southeastern Washington, U.S. Weather Bureau, Walla Walla, Washington, May 1970 (unpublished Presentation).

2.3-12 Holzworth, G. C., "Estimates of Mean Maximum Depths in the Contiguous United States," Monthly Weather Review, Vol. 92, pp 235-242, May 1964.

2.3-13 Hosler, C. R., "Low-Level Inversion Frequency in the Contiguous United States," Monthly Weather Review, Vol. 89, pp 319-339, September 1961.

2.3-14 Huschke, R. E., ed., Glossary of Terms Frequently Used in Air Pollution, American Meteorological Society, Boston, Massachusetts, January 1968.

2.3-15 Jenne, D. E., Frequency Analysis of Some Climatological Extremes at Hanford, General Electric, Hanford Atomic Products Operation, Richland, Washington, April 1963.

2.3-16 Hilst, G. R., and Nickola, P. W., "On Wind Erosion of Small Particles," Bulletin of the American Meteorological Society, Vol. 40, pp 73-77, February 1959.

2.3-17 Sehmel, G. A., and Lloyd, F. D., Airborne Dust Concentrations, Pacific Northwest Laboratories Annual Report for 1971 to the USAEC Division of Biology and Medicine, Vol. II, Part 1, Atmospheric Sciences, Battelle Pacific Northwest Laboratories, BNWL-1651, Richland, Washington, December 1972.

2.3-18 Bramson, P. E., and Corley, J. P. Environmental Surveillance at Hanford for CY-1971, Battelle Northwest Laboratories, BNWL-1683, Richland, Washington, August 1972.

2.3-19 ANSI A58, 1-1972, "Building Code Requirements for Minimum Design Loads in Buildings and Other Structures," American National Standards Institute, 1972.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-40 2.3-20 Simpson, C. L., Computer Printouts of Meteorological Data from the HMS and Hanford No. 2 Sites, March 1-August 31, 1972, BNWL, September 1972.

2.3-21 PSAR WPPSS Nuclear Project No. 1, August 1974 (Docket No. 50-460).

2.3-22 Droppo, J. G. et al., Atmospheric Effects of Circular Mechanical Draft Cooling Towers at Washington Public Power Supply System Nuclear Power Plant Number Two, Final Report to Burns and Roe, Inc., November 1976.

2.3-23 Quality Assurance Program for the Acquisition, Processing, and Analysis of Meteorological Data for Washington Public Power Supply System Nuclear Project No. 2, Battelle Pacific Northwest Laboratories, Richland, Washington, April 1974.

2.3-24 Regulatory Guide 1.70, Rev. 3, Standard Format and Content of Safety Analysis Reports For Nuclear Power Plants, November 1978.

2.3-25 T. J. Bander, "PAVAN: An Atmospheric Dispersion Program for Evaluating Design Basis Accidental Releases of Radioactive Materials from Nuclear Power Stations," NUREG/CR-2858 (November 1982).

2.3-26 U.S. Nuclear Regulatory Commission, 1979: Regulatory Guide 1.145, "Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants," USNRC Office of Standards Development, Wash., D.C.

2.3-27 Gifford, F. A., 1975: Atmospheric Dispersion Models for Environmental Pollution Applications. Lectures on Air Pollution and Environmental Impact Analyses, American Meteorological Society, pp. 35-38.

2.3-28 PSAR WPPSS Nuclear Project No. 2, February 1973.

2.3-29 Fix, J. J., Environmental Surveillance at Hanford for CY-1974, Battelle Northwest Laboratories, BNWL-1910, Richland, Washington, April 1975.

2.3-30 Orgill, M. M., G. A. Sehmel, and T. J. Bander, 1974: "Regional Wind Resuspension of Dust," Pacific Northwest Laboratory Annual Report for 1973, to the USAEC Division of Biomedical and Environmental Research, Part 3, Atmospheric Sciences, BNWL-1850, pp. 214-219.

2.3-31 Hagen, L. J. and N. P. Woodruff, 1973: "Air Pollution from Duststorms in the Great Plains," Atmos. Environ., 7, pp. 323-332.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-41 2.3-32 Sehmel, G. A., 1976: "The Influence of Soil Insertion on Atmospheric Particle Size Distributions," Pacific Northwest Laboratory Annual Report to ERDA Division of Biomedical and Environmental Research, Part 3, Atmospheric Sciences, BNWL-200, pp.99-101.

2.3-33 A. Brandstetter of BNL to J. J. Verderber of Burns and Roe Inc., entitled "Hanford Duststorm Climatology Environmental Studies for CGS," and dated December 2, 1977.

2.3-34 U.S. Atomic Energy Commission, 1972: Regulatory Guide 1.23, Onsite Meteorological Programs.

2.3-35 Briggs, G. A., 1973: "Diffusion Estimation for Small Emissions in Environmental Research Laboratory," Air Resources Atmos. Turbc. and Diffusion Lab. 1973 Annual Report, ATDL-106, USDOC-NOAA.

2.3-36 NUREG-6331, "Atmospheric Relative Concentrations in Building Wakes," Revision 1, May 1997, ARCON96 RSICC Computer Code Collection November CCC-664. 2.3-37 Calculation NE-02-03-14, "Control Room /Q Using ARCON96 with 1996-1999 Meteorological Data." 2.3-38 Calculation NE-02-03-16, "Calculation of the EAB and LPZ /Q Using PAVAN with 1996-1999 Meteorological Data."

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-43Table 2.3-1 Averages and Extremes of Climatic Elements at Hanford (Based on all Available Records to and Including the Year 1980) PAGE 1 OF 2 TEMPERATURE (F) DEGREE DAYS (BASE 65F) PRECIPITATION (INCHES) 1912-1980 AVERAGES 1912-1980 EXTREMES DEGREE DAYS (BASE 65F) 1912-1980 TOTALS DAILY MAXIMUM DAILY MINIMUM HEATING 1945-1980 TOTALS COOLING 1960-1980 TOTALS SNOW, ICE PELLETS (SLEET) DAILY MAXIMUM DAILY MINIMUM MONTHLY HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR RECORD HIGHEST YEAR RECORD LOWEST YEAR RECORD HIGHEST YEAR RECORD LOWEST YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MINIMUM MONTHLY YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MINIMUM MONTHLY YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MINIMUM MONTHLY YEAR MAX. IN 24 HOURS YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MAX. IN 24 HOURS YEAR MAXIMUM DEPTH YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Year 36.6 45.4 56.5 66.2 75.5 83.2 91.8 89.3 79.6 65.4 48.4 39.4 64.8 21.9 27.3 33.7 40.0 47.8 55.3 61.0 59.2 50.8 40.6 31.3 26.0

41.2 29.3 36.3 45.1 53.1 61.7 69.3 76.4 74.3 65.2 53.0 39.8 32.7

53.0 42.5 44.5 49.8 59.6 68.8 75.4 81.8 81.5 71.7 59.0 46.0 38.5

81.8 1953 1958 1926 1934 1947 1922 1960 1967 1967 1952 1954 1957 July 1960 12.1 21.4 39.4 47.5 56.6 63.0 72.4 69.8 58.8 48.8 31.3 18.5

12.1 1950 1929 1955 1955 1933 1953 1963 1964 1926 1930 1955 1919 Jan 1950 72 71 83 95 103 110 115 113 102 90 75 69 115 1971 1924 1960 1934 1936+

1912 1939 1961 1976+

1933 1975 1980 July 1939 -2

-3 24 41 49 55 59 63 52 31 14 -3 -3 1950 1950 1960 1945 1918 1966 1966 1920 1934 1935 1955 1919 Feb 1950+ 53 55 54 60 70 81 82 81 72 60 52 56 82 1971 1932 1942 1956 1956 1924 1925 1961+

1955 1945+

1959+

1975 July 1925 -23

-23 6 12 23 33 39 40 25 6 27 -27 1934 1950 1955 1935 1954 1933 1979 1918 1926 1935 1955 1919 Dec 1919 1104 781 638 381 156 35 4 6 70 376 758 990 5299 1640 1147794 522 25890 22 32179 4791008 122416401950 1956 1955 1955 1977 1953 1955 1960 1972 1946 1955 1964 Jan 1950 694 576 476 253 36 3 0

0 10 200 567 822 0 1953 1958 1947 1977 1947 1938 1975+1979+1979+1952 1954 1957 Aug 1979+0 0

0 2 43 183 384 323 102 2 0

0 1039 0 0

0 24 94 310 518 508 216 10 0 0 518 ------

---

---

1977 1971 1969 1960 1967 1967 1971

---

---

July 1960 0 0

0 0

3 57 232 171 27 0 0

0 0 ------

---

---

1978+

1962 1980 1963 1964 1970 1977+

---

---

Apr 1978+ 0.92 0.60 0.37 0.39 0.48 0.54 0.15 0.24 0.31 0.56 0.85 0.89

6.302.47 3.08 1.86 1.22 2.03 2.92 0.81 1.36 1.34 2.72 3.05 2.53 3.081970 1940 1957 1969 1972 1950 1966 1977 1947 1957 1926 1931 Feb 1940 0.08 T 0 0

0 0

0 0 T 0 T 0.11 0 1977 1967 1942+

1933+

1931 1919 1939+

1955+

1976+

1917+

1976+

1976+

Aug 1955+ 1.08 1.24 0.59 0.58 1.39 1.50 1.25 0.89 0.82 1.91 0.78 1.00 1.91 1948 1916 1949 1980 1972 1934 1942 1977 1947 1957 1966 1958 Oct 1957 5.3 2.3 0.3 T T 0 0

0 0 T 1.4 3.9 13.223.4 26.04.2 T T 0 0

0 0 1.5 12.7 19.1 26.01950 1916 1951 1968+

1960

---

---

---

---

1973 1955 1964 Feb 1916 7.1 18.02.2 T T 0 0

0 0 1.5 8.3 5.4 18.01954 1916 1957 1968+

1960

---

---

---

---

1973 1978 1965 Feb 1916 12.0 24.52.3 0 0

0 0

0 0 1.5 9.1 12.1 24.51969 1916 1957

---

---

---

---

---

---

1973 1978 1964 Feb 1916 WIND (mph) RELATIVE HUMIDITY (%) SKY COVER (SCALE 0-10) SOLAR RADIATION (LANGLEYS)* 1945-1980 AVERAGES PEAK GUSTS 1946-1980 AVERAGES 1946-1980 EXTREMES 1946-1980 AVERAGES (SUNRISE TO SUNSET) 1953-1980 AVERAGES DAILY TOTALS 1953-1980 EXTREME DAILY TOTALS PREVAILING DIRECTION MEAN MONTHLY SPEEDS HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR SPEED DIRECTION YEAR MEAN HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR HIGHEST YEAR LOWEST YEAR MONTHLY HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR MONTHLY HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Year NW NW WNW WNW WNW WNW WNW WNW WNW WNW NW NW

WNW 6.4 7.1 8.5 9.0 8.9 9.2 8.7 8.0 7.5 6.6 6.1 6.1

7.7 10.3 10.8 10.7 11.1 10.5 10.7 9.6 9.1 9.2 9.1 8.2 8.3 11.1 1972 1976 1977+ 1972+ 1965+ 1949 1963 1946 1961 1946 1977 1968 Apr 1972+ 3.1 4.6 5.9 7.4 5.8 7.7 6.8 6.0 5.4 4.4 2.9 3.9

2.9 1955 1963 1958 1958 1957 1950+ 1955 1956 1957 1952 1956 1963+ Nov 1956 80 65 70 73 71 72 69 66 65 63 64 71 80 SW SW SW SSW SSW SW WSW SW SSW SSW SSW SW

SW 1972 1971 1956 1972 1948 1957 1979 1961 1953 1950 1949 1955 Jan 1972 76.4 70.7 55.9 46.9 43.0 39.7 32.2 35.6 41.6 56.8 73.6 80.0 54.3 88.8 86.9 65.9 64.5 61.9 53.5 40.5 47.8 55.5 74.2 88.7 90.5 90.5 1960 1963 1950 1963 1948 1950 1955 1976 1977 1962 1979 1950 Dec 1950 60.0 54.0 44.0 36.9 31.2 30.0 21.9 24.5 33.2 42.5 62.8 69.0 21.9 1963 1967 1965 1966 1966 1949 1959 1967 1974 1952 1976 1968 July 1959 100 100 100 100 100 100 99 100 100 100 100 100 100 1980+ 1980+ 1979+ 1978+ 1978+ 1977+ 1972 1972+ 1978+ 1980+ 1980+ 1980+ Dec 1980+ 13 14 12 9 7 10 6 7 10 10 16 26 6 1963 1962 1965+ 1954 1953 1964+ 1951 1951 1962+ 1952+ 1976+ 1972 July 1951 7.9 7.6 6.8 6.4 5.9 5.3 2.9 3.4 4.1 5.8 7.7 8.1 6.09.2 9.3 8.5 8.1 7.7 7.0 4.7 5.9 6.7 8.0 9.1 9.2 9.3 1978 1980 1978 1963 1977+

1950 1976 1968 1978 1975 1972 1962 Feb 1980 4.3 5.9 4.9 3.7 4.5 2.8 0.9 0.6 1.4 3.9 6.2 6.4 0.6 1949 1964 1965 1951 1945 1961 1953 1955 1975 1952 1957 1978 Aug 1955 116 194 335 469 569 627 650 548 415 262 130 89 367 136 238 388 535 634 698 714 613 463 303 180 116 714 1973 1970 1965 1973 1970 1960 1973 1955 1975 1976 1957 1970 July 1973 78 128 293 374 472 537 588 475 326 216 97 57 57 1978 1980 1978 1963 1980 1980 1955 1968 1977 1975 1979+ 1980+ Dec 1980+277 422 542 704 838 821 808 721 591 434 295 196 838 1969 1958 1968 1972 1977 1971 1974 1957 1970 1973 1971 1972 May 1977 16 21 44 75 67 112 118 107 61 33 14 9 9 1976+

1976 1979 1974 1962 1965 1972 1959 1957 1974 1969 1973 Dec 1973 EXTREME AVERAGES OR TOTALS AND YEAR OR SEASON OF OCCURRENCE 1912-1980 TEMPERATURE AVERAGES (F) HIGHEST ANNUAL 56.2 (1958+)

LOWEST ANNUAL 50.2 (1929)

HIGHEST WINTER (D-J-F) 41.1 (1933-34)

LOWEST WINTER 24.2 (1948-49)

HIGHEST SPRING (M-A-M) 58.2 (1947)

LOWEST SPRING 48.0 (1955)

HIGHEST SUMMER (J-J-A) 78.2 (1958)

LOWEST SUMMER 70.2 (1980)

HIGHEST FALL (S-O-N) 56.6 (1963) LOWEST FALL 49.5 (1978) 1912-1980 PRECIPITATION TOTALS (IN.)

GREATEST ANNUAL 11.45 (1950)

LEAST ANNUAL 2.99 (1976)

SNOW, ICE PELLETS (SLEET)

GREATEST SEASONAL 43.6 (1915-16)

LEAST SEASONAL 0.3 (1957-58)

1945-1980 WIND SPEED AVERAGE (MPH)

HIGHEST ANNUAL 8.3 (1968+)

LOWEST ANNUAL 6.3 (1957)

1945-1980 RELATIVE HUMIDITY AVERAGE (%)

HIGHEST ANNUAL 58.9 (1978)

LOWEST ANNUAL 49.4 (1967)

1945-1980 SKY COVER AVERAGES (SUNRISE TO SUNSET, SCALE 0-10)

HIGHEST ANNUAL 6.6 (1978+)

LEAST ANNUAL 5.1 (1949)

1953-1980 SOLAR RADIATION AVERAGE DAILY TOTAL (LANGLEYS)

HIGHEST ANNUAL 390 (1973) LOWEST ANNUAL 324 (1980)

• CALORIES/cm2 +ALSO ON EARLIER YEARS COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-44NUMBER OF DAYS CLEAR (0-3 TENTHS SKY COVER, SR TO SS)

GREATEST ANNUAL (1954-80) 121 1960 LEAST ANNUAL (1954-80) 80 1977

CLOUDY (9-10 TENTHS SKY COVER, SR TO SS)

GREATEST ANNUAL (1954-80) 193 1978 LEAST ANNUAL (1954-80) 85 1966

THUNDERSTORMS GREATEST ANNUAL (1945-80) 23 1948 LEAST ANNUAL (1945-80) 3 1949

HEAVY FOG (VIS. 1/4 MILE OR LESS)

GREATEST SEASONAL (1945-80) 42 1950-51 LEAST SEASONAL (1945-80) 9 1948-49

PRECIPITATION 0.10 INCH OR MORE GREATEST ANNUAL (1946-80) 39 1950 LEAST ANNUAL (1946-80) 10 1965

SNOW 1.0 INCH OR MORE GREATEST SEASONAL (1946-80) 15 1955-56 LEAST SEASONAL (1946-80) 0 1976-77

3 IN. OR MORE SNOW ON GROUND GREASTEST SEASONAL (1946-80) 40 1978-79+

LEAST SEASONAL (1946-80) 0 1976-77

PEAK GUST 40 MPH OR GREATER GREATEST ANNUAL (1945-80) 41 1961 LEAST ANNUAL (1945-80) 10 1978

MAX. TEMPERATURE 90 OR ABOVE GREATEST ANNUAL (1912-80) 85 1940+

LEAST ANNUAL (1912-80) 29 1980

MAX. TEMPERATURE 100 OR ABOVE GREATEST ANNUAL (1912-80) 32 1942 LEAST ANNUAL (1912-80) 1 1954

MAX. TEMPERATURE 32 OR BELOW GREATEST SEASONAL (1912-80) 53 1955-56 LEAST SEASONAL (1912-80) 1 1937-38

MIN. TEMPERATURE 32 OR BELOW GREATEST SEASONAL (1912-80) 141 1916-17 LEAST SEASONAL (1912-80) 75 1957-58

MIN. TEMPERATURE 0 OR BELOW GREATEST SEASONAL (1912-80) 18 1949-50 LEAST SEASONAL (1912-80)01976-77Table 2.3-1 Averages and Extremes of Climatic Elements at Hanford (Based on all Available Records to and Including the Year 1980) (Continued) PAGE 2 OF 2 NUMBER OF DAYS (1954-1980) NUMBER OF DAYS (1945-1980)

• CLEAR PTLY CLDY CLOUDY THUNDERSTORMS HEAVY FOG (VIS. 1/4 MI. OR LESS) PRECIPITATION 0.10 INCH OR MORE SNOW 1.0 INCH OR MORE MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MONTHLY MEAN GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Year 3 4

6 6

8 10 19 18 15 10 4 3 106 7 9 12 12 14 21 26 30 27 14 10 9 30 1963 1968+

1979+

1962 1973 1961 1960 1955 1975 1980+

1957 1978 Aug 1955 0 0

1 1

1 5 13 9 6

1 1

1 0 1955+

1980+

1978+

1963 1977 1972+

1976+

1978 1978 1975 1973+

1980+

Feb 1980+ 5 5

8 9 11 10 7 7

7 7

5 5 86 22 19 17 15 12 10 5 6

8 14 21 23 172 28 26 23 21 19 15 12 13 16 22 25 28 28 1978 1980+

1977 1979+

1977+

1980+

1976 1968 1977 1973 1973+

1962 Jan 1978+ 17 12 9 6

6 5

0 0

1 9 15 17 0 1963 1964 1979+

1956 1958 1979+

1967 1969+

1975 1970 1961 1978 Aug 1969+ 0

1 2

2 2

2 1

0

1. 10 0 1

1 3

7 8

7 8

4 2

0 1 8 ------

1972+

1969+

1979+

1956 1972+

1975 1953 1959 1976

---

1971 June 1972+ 0 0

0 0

0 0

0 0

0 0

0 0 0 ------

1980+

1980+

1977+

1977+

1963+

1973+

1974+

1976+

1980+

---

1980+

---

6 3

1

0

1 6

8 25 15 11 5 1

1 1

0 1

1 7 13 17 17 1976 1963 1951 1975+

1958 1971

---

1959 1977 1980 1965 1950 Dec 1950 0 0

0 0

0 0

0 0

0 0

0 2 0 1949 1977 1980+

1980+

1980+

1980+

---

1980+

1980+

1978+

1960 1968+ ------ 3 2 2

1 2

2 1

1 1

2 3

3 23 8 5

8 5

4 8

3 4

5 8 10 9 10 1970 1980+

1957 1948 1980+

1950 1974+

1976+

1977+

1950 1973 1964 Nov 1973 0 0

0 0

0 0

0 0

0 0

0 0 0 1977+

1979+

1980+

1977+

1979+

1979+

1980+

1980+

1978+

1978+

1976+

1976+

Aug 1980+ 2 1

0 0

0 0

0 0

1 1

2 6 10 4 2

0 0

0 0

0 0

1 6

6 10 1950 1975+

1957+

---

---

---

---

---

---

1973 1955 1964 Jan 1950 0 0

0 0

0 0

0 0

0 0

0 0 0 1977+

1979+

1980+

---

---

---

---

---

---

1980+

1980+

1976+ ------ NUMBER OF DAYS (1945-1980) NUMBER OF DAYS (1912 - 1980) 3" OR MORE SNOW ON GND. PEAK GUST 40 MPH OR GREATER MAX. TEMP 90 OR ABOVE MAX. TEMP 100 OR ABOVE MAX. TEMP. 32 OR BELOW MIN. TEMP. 32 OR BELOW MIN. TEMP 0 OR BELOW MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLYY YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Year 5 3 0

0 0

0 0

0 0

0 1

2 11 23 16 0 0

0 0

0 0

0 0 12 14 23 1969 1950

---

---

---

---

---

---

---

---

1978 1955 Jan 1969 0 0 0

0 0

0 0

0 0

0 0

0 0 1977+

1978+

---

---

---

---

---

---

---

---

1980+

1980+

---

3 2 3

3 2

2 1

1 1

2 2

3 25 11 10 9 7

6 6

4 5

4 8

5 8 11 1972 1976 1956 1972 1971+

1973 1979+

1951 1946 1967 1973+

1957+

Jan 1972 0 0 0

0 0

0 0

0 0

0 0

0 0 1979+

1978+

1978 1979+

1977 1980+

1977+

1980+

1980+

1979+

1979+

1969+

---

0 0 0

3 9 20 18 5

0 0 55 0 0

0 4 11 20 29 29 16 1 0

0 29 ------

---

---

1926 1924 1940+

1941 1915 1938 1933

---

---

July 1941 0 0 0

0 0

0 8

7 0

0 0

0 0 ------

---

---

1980+

1980+

1980+

1963 1948 1977+

1980+

---

---

---

0 0 0

0

2 7

4

0 0

0 13 0 0

0 0

1 9 16 16 2 0

0 0 16 ------

---

---

---

1966+

1970 1971+

1942 1955+

---

---

---

July 1971+ 0 0 0

0 0

0 0

0 0

0 0

0 0 ------

---

---

---

1980+

1980+

1963+

1980+

1980+

---

---

---

---

11 3 #

0 0

0 0

0 0

2 8 24 30 15 2 0

0 0

0 0

0 2 15 19 30 1979 1956 1960

---

---

---

---

---

---

1935 1955 1914 Jan 1979 0 0 0

0 0

0 0

0 0

0 0

0 0 1967+

1976+

1980+

---

---

---

---

---

---

1980+

1976+

1974+

---

27 21 15 5

0 0

0

5 17 25 115 31 28 25 15 3 0

0 0

4 12 30 31 31 1980+

1944+

1944+

1935 1938

---

---

---

1933+

1916 1936 1978+

Jan 1980+ 9 5 6

0 0

0 0

0 0

0 4 14 0 1953 1958 1968+

1974+

1980+

---

---

---

1980+

1962+

1949 1933

---

2 1 0

0 0

0 0

0 0

0

1 4 14 9 0

0 0

0 0

0 0

0 1 14 14 1950 1929

---

---

---

---

---

---

---

---

1955+

1919 Jan 1950+ 0 0 0

0 0

0 0

0 0

0 0

0 0 1977+

1980+

---

---

---

---

---

---

---

---

1980+

1980+

---

REFERENCE NOTES

• PRECIPITATION OBSERVATIONS NOT BEGUN UNTIL 1946

1. LESS THAN 1/2

+ ALSO ON EARLIER YEARS LOCATION AND HISTORY PRESENT LOCATION 25 MILES NW OF RICHLAND, WASHINGTON LATITUDE 4634'N; LONGITUDE 11936'W, ELEVATION 733 FEET OBSERVATIONS FROM 1912 TO 1944 WERE BY UNITED STATES WEATHER BUREAU COOPERATIVE OBSERVERS AT A SITE ABOUT 10 MILES ENE OF PRESENT LOCATION. SINCE 1944, OBSERVATIONS HAVE BEEN MAINTAINED ON A 24 HOUR-A-DAY BASIS BY THREE DIFFERENT DOE CONTRACTORS.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-45Table 2.3-2 Average Return Period (R) and Existing Record (ER) for Various Precipitation Amounts and Intensity During Specified Time Periods at Hanford (Based on Extreme Value Analysis of 1947-1969 Records) Amount (Inches) Intensity (Inches per Hour) Time Period Time Period R (YEARS) 20 MIN 60 MIN 2 HRS 3 HRS 6 HRS 12 HRS 24 HRS 20 MIN 60 MIN 2 HRS 3 HRS 6 HRS 12 HRS 24 HRS2 5 10 25 50 100 250 500 1000 0.16 0.24 0.37 0.47 0.53 0.60 0.68 0.73 0.80 0.26 0.40 0.50 0.62 0.72 0.81 0.93 1.02 1.11 0.30 0.48 0.59 0.74 0.85 0.96 1.11 1.22 1.33 0.36 0.55 0.67 0.83 0.96 1.07 1.22 1.33 1.45 0.48 0.77 0.96 1.21 1.40 1.59 1.82 2.00 2.20 0.62 0.95 1.17 1.45 1.66 1.87 2.13 2.34 2.55 0.72 1.06 1.28 1.56 1.77 1.99 2.26 2.47 2.68 0.49 0.72 1.1 1.4 1.6 1.8 2.0 2.2 2.4 0.26 0.40 0.50 0.62 0.72 0.81 0.93 1.02 1.11 0.15 0.24 0.30 0.37 0.42 0.48 0.55 0.61 0.67 0.12 0.18 0.22 0.28 0.32 0.36 0.41 0.44 0.48 0.08 0.13 0.16 0.20 0.23 0.27 0.30 0.33 0.37 0.052 0.079 0.098 0.121 0.138 0.156 0.177 0.195 0.212 0.030 0.044 0.053 0.065 0.074 0.083 0.094 0.103 0.112

• No records have been kept for time periods of less than 60 minutes. However, the rain gage chart for 6-12-69 shows that 0.55 inch occurred during a 20-minute period from 1835 to 1855 PST. An additional 0.01 inch occurred between 1855 and 1910 to account for the record 60-minute amount of 0.59 inch.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-46Table 2.3-3 Miscellaneous Snowfall Statistics (1946 Through 1970) Oct Nov Dec Jan Feb Mar Season Average number of days with depth at 0400 PST 1" or more 3" or more 6" or more 12" or more 0 0

0 0 1 1

0 0 5 2

1

1. 10 5 3

1. 5 3

1 0 #

0 0

0 21 11 5

1. Record greatest number of days with depth at 0400 PST 1" or more 3" or more 6" or more 12" or more 0 0 0 0 (1955) 11 (1955) 10 0 0 (1964+) 17 (1955) 14 (1964) 12 (1964) 4 (1969) 31 (1969) 23 (1965) 23 (1969) 1 (1950) 17 (1950) 16 (1969+) 8 0 (1951) 3 0 0

0 (1955-56) 54 (1949-50) 38 (1949-50) 23 (1964-65) 4 Record greatest depth (1957) 0.3 (1946) 5.1 (1964) 12.1 (1969) 12.0 (1969) 10.0 (1957) 2.3 (Dec 1964) 12.1 Greatest in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (1957) 0.3 (1955) 4.8 (1965) 5.4 (1954) 7.1 (1959) 5.2 (1957+) 2.2 (Jan. 1954) 7.1 Average % of water equivalent of all precipitation 2 14 46 48 29 14 26 ( ) Denotes year of occurrence

+ Denotes also in earlier years

1. Denotes less than 1/2 day COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-47 Table 2.3-4 Tornado History Within 100 Miles of CGS Date Location June 26, 1916 Walla Walla, Washington April 15, 1925 Condon, Oregon

September 2, 1936 Walla Walla, Washington

May 20, 1948 Yakima, Washington

May 29, 1948 Yakima, Washington

June 11, 1948 Ephrata, Washington

June 16, 1948 Hanford Reservation

May 9, 1956 Kennewick, Washington

April 12, 1957 Ione, Oregon

April 30, 1957 Yakima, Washington

May 6, 1957 Harrington, Washington

April 24, 1958 Walla Walla, Washington June 26, 1958 Wallula Junction, Washington March 14, 1966 Little Goose Dam, Washington Note: No major damage or loss of life was associated with any of the tornadoes.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-48 Table 2.3-5 Monthly and Annual Prevailing Directions, Average Speeds, and Peak Gusts: 1945-1970 at HMS (50 ft level) Peak Gust Month Prev Den Avg Speed HighestAvg Year LowestAvg Year Speed Den Year Jan NW 6.4 9.6* 1953 3.1 1955 65** S 1967 Feb NW 7.0 9.4 1961 4.6 1963 63 SW 1965 Mar WNW 8.4 10.7 1964 5.9 1958 70 SW 1956 Apr WNW 9.0 11.1 1959 7.4 1958 60 WSW 1969 May WNW 8.8 10.5 1965+ 5.8 1957 71 SSW 1943 June WNW 9.2 10.7 1949 7.7 1950+ 72 SW 1957 July WNW 8.6 9.6 1963 6.8 1955 55 WSW 1963 Aug WNW 8.0 9.1 1946 6.0 1956 66 SW 1961 Sept WNW 7.5 9.2 1961 5.4 1957 65 SSW 1953 Oct WNW 6.7 9.1 1946 4.4 1952 63 SSW 1950 Nov NW 6.2 7.9 1945 2.9 1956 64 SSW 1949 Dec NW 6.0 8.3 1968 3.9 1963+ 71 SW 1955 Year WNW 7.6 8.3 1968+ 6.3 1957 72** SW June 1957

• The average speed for January, 1972, was 10.3 mph

• • On January 11, 1972, a new all-time record peak gust of 80 mph was established COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-49Table 2.3-6 Speed and Direction of Daily Peak Gusts* Speed Class (mph) Extreme High and Date of Occurrence ** Direction Under 10 10-19 20-2930-39 40-4950-59 60-69 70 orover Total mph Date NNE 0.2 0.8 1.3 0.2 0.1 0 0 0 2.6 47 Feb. 5, 1948 NE 0.3 1.0 1.0 0.2 0 0 0 0 2.5 38 July 10, 1951 ENE 0.2 0.6 0.3 0.1 0 0 0 0 1.2 37 May 27, 1947 E 0.2 0.7 0.2 0.1 # 0 0 0 1.2 44 June 11, 1950 ESE 0.1 0.4 0.1 0 0 0 0 0 0.6 26 June 2, 1958 SE 0.7 2.0 0.4 # # # 0 0 3.1 53 Aug. 29, 1947 SSE 0.7 1.8 0.5 0.1 0.1 # 0 0 3.2 52 Dec. 4, 1952 S 0.3 0.8 1.0 0.7 0.3 0.2 # 0 3.3 58 Dec. 23, 1957 SSW 0.1 0.9 1.5 1.4 0.8 0.4 0.1 # 5.2 71 May 26, 1948 SW 0.2 0.7 3.6 3.4 1.7 0.4 0.1 0.1 10.2 72 June 5, 1957 WSW 0.2 1.5 2.7 2.4 1.1 0.2 0 0 8.1 58 Nov. 3, 1958 L W 0.3 2.2 2.1 1.0 0.3 # 0 0 5.9 52 Nov. 4, 1958 L WNW 1.0 9.6 8.0 5.4 0.6 # 0 0 24.6 50 July 19, 1953 NW 1.5 9.6 6.8 5.1 0.8 0 0 0 23.8 49 April 6, 1952 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-50Table 2.3-6 Speed and Direction of Daily Peak Gusts* (Continued) Speed Class (mph) Extreme High and Date of Occurrence ** Direction Under 10 10-19 20-29 30-39 40-49 50-59 60-69 70 orover Total mph Date NNW 0.4 0.8 0.3 # 0 0 0 0 1.5 38 May 8, 1955 N 0.2 1.1 1.4 0.2 0.1 0 0 0 3.0 46 Aug. 27, 1951 Summary 6.6 34.5 31.2 20.3 5.9 1.2 0.2 0.1 100.0 --- ---

• Based on 12 years of observations (1947-58). Tabular values under speed classes denote percent of all daily observations made during the period. L Denotes the latest of several occurrences.

1. Denotes less than .05%.

• • A new record was set on January 11, 1972, when a peak gust of 80 mph was recorded at the 50 foot level at the Hanford Meteorology Station. Reference Document BNWL-1640 "The Hanford Wind Storm of January 11, 1972." dated February 1972, issued by Battelle Pacific Northwest Laboratories.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-51 Table 2.3-7a CGS and HMS Hourly Meteorological Data, August 7-9, 1972 (Ultimate Heat Sink Studies) CGS Site HMS Tower Site Day/Hour Wind Direction (degrees) Wind Speed (mph) Dry Bulb (F) Relative Humidity (percent) Wet Bulb (F) Wind Direction (degrees) Wind Speed (mph) Dry Bulb (F) Wet Bulb (F) Elevation 23 feet 23 feet 3 feet 3 feet 3 feet 50 feet 7 feet 7 feet 7 feet 7/1 7/2 7/3 7/4 7/5 7/6 7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 30 50 160 80 50 70 100 70 70 100 130 140 360 80 110 110 90 60 50 50 40 60 100 30 5 5

5 5

5 4

5 4

4 5

5 5

6 8

8 9

9 9 12 12 8 6

5 4 76 72 71 69 65 61 61 59 67 77 85 91 96 99 102 106 107 108 106 106 103 96 89 85 35 36 44 48 51 64 64 68 66 54 46 38 35 32 30 28 25 24 23 23 22 22 26 34 60 58 59 58 55 54 54 53 59 65 69 71 73 74 76 77 77 77 75 75 73 69 66 66 220 270 300 270 180 110 300 320 320 Variable 40 Variable 90 110 90 Variable 90 90 110 90 130 220 300 270 6 6

5 5

4 2

1 5

3 1

3 3

5 5

4 4

8 8

7 8

7 6

8 5 78 76 78 74 72 67 76 81 85 92 93 98 102 104 105 107 108 106 103 97 90 84 82 81 57 56 57 54 55 53 57 60 61 64 64 66 68 68 69 69 69 68 67 64 62 60 58 58 8/1 8/2 8/3 8/4 8/5 8/6 8/7 8/8 8/9 8/10 8/11 8/12 8/13 8/14 8/15 8/16 8/17 8/18 8/19 8/20 8/21 8/22 8/23 8/24 360 130 40 20 40 80 100 140 130 130 120 70 70 40 60 70 30 30 90 110 320 320 320 320 6 5

5 7

6 5

5 4

5 5

7 7

6 6

7 7

8 8

8 8 19 21 15 15 79 72 70 71 71 67 65 62 67 77 85 90 95 98 101 104 106 108 106 106 108 100 95 91 36 39 42 46 46 46 52 54 56 53 46 40 37 34 32 30 28 27 26 25 26 26 28 28 63 58 58 59 59 56 55 53 57 64 69 71 73 74 76 77 77 78 77 76 78 73 71 68 270 270 200 240 200 300 320 20 140 110 110 60 90 90 130 110 220 270 300 300 300 300 300 270 4 4

4 1

4 5

5 3

2 3

4 4

4 4

4 6 10 16 20 21 21 22 16 16 78 77 78 71 70 69 79 85 87 91 93 97 103 104 106 108 108 106 102 96 91 90 87 85 57 57 57 53 53 53 60 63 63 65 65 67 69 69 70 70 70 68 70 66 66 63 64 63 9/1 9/2 9/3 9/4 9/5 9/6 9/7 9/8 9/9 9/10 9/11 9/12 9/13 9/14 9/15 9/16 9/17 9/18 9/19 9/20 9/21 9/22 9/23 9/24 320 320 180 Variable 150 140 160 200 190 200 180 170 190 200 160 300 250 300 310 320 320 320 320 320 17 10 7 5

6 5

5 7

7 8

6 5

7 10 8 13 13 17 14 20 22 17 13 16 90 89 84 77 72 70 71 68 73 81 89 94 98 100 100 102 104 104 104 102 96 93 87 84 32 32 34 35 46 54 57 58 60 56 50 44 38 34 30 30 28 26 27 26 27 29 30 30 69 68 65 61 60 59 61 59 63 68 72 74 76 76 74 76 76 75 76 74 71 70 66 64 270 240 300 240 270 240 240 220 240 320 320 220 220 220 220 240 300 300 300 300 300 300 300 300 9 6

7 6 11 10 8 6 10 9 6

5 10 15 15 13 16 20 20 17 16 18 19 14 83 82 78 80 82 82 82 87 89 94 96 99 101 101 101 103 102 97 93 88 83 80 79 78 63 61 60 62 63 63 63 65 65 65 66 67 68 67 67 68 68 67 65 63 61 60 60 60 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-52 Table 2.3-7b CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level) (Ultimate Heat Sink Studies) Day/Hour Wind Speedmph Dry Bulb F Dewpoint F Wet Bulb F 4/1 4/2 4/3 4/4 4/5 4/6 4/7 4/8 4/9 4/10 4/11 4/12 4/13 4/14 4/15 4/16 4/17 4/18 4/19 4/20 4/21 4/22 4/23 4/24 3.56 3.66 1.71 4.88 2.96 2.76 5.21 3.33 6.02 5.97 12.36 9.67 9.55 8.89 6.28 5.85 6.13 3.55 3.41 5.64 3.88 3.61 3.97 4.81 66.13 64.91 64.16 62.69 61.87 65.60 72.51 77.12 81.71 83.95 90.00 94.48 97.15 99.57 102.37 103.49 104.27 104.77 103.68 95.64 91.49 86.72 83.92 79.60 53.17 54.85 53.92 53.41 53.57 55.20 55.95 54.84 55.52 57.71 55.57 57.09 57.97 58.00 56.77 54.77 52.40 51.20 49.57 59.28 57.55 56.56 58.68 57.84 58.41 58.86 58.07 57.22 56.99 59.30 62.22 63.26 65.16 67.00 67.88 69.99 71.21 71.93 72.17 71.63 70.88 70.56 69.61 71.39 69.30 67.32 67.50 65.66 5/1 5/2 5/3 5/4 5/5 5/6 5/7 5/8 5/9 5/10 5/11 5/12 5/13 5/14 5/15 5/16 5/17 5/18 5/19 5/20 5/21 5/22 5/23 5/24 4.96 3.90 3.30 6.61 6.06 5.00 5.28 2.94 4.87 8.24 5.82 5.69 6.13 4.74 7.52 6.43 4.65 6.93 6.48 6.79 5.25 6.05 3.95 6.34 76.83 74.83 71.68 70.93 71.15 72.99 77.84 81.95 87.01 92.11 96.69 98.96 100.80 103.79 105.36 105.81 104.53 103.48 101.04 96.64 93.63 89.23 87.41 83.80 57.17 55.47 55.41 54.56 55.57 55.89 57.41 58.51 57.89 56.24 54.80 57.68 60.27 54.99 54.77 55.09 53.25 52.80 57.15 57.79 57.23 56.43 57.25 58.84 64.37 62.79 61.64 60.92 61.54 62.36 64.84 66.78 68.07 68.85 69.61 71.60 73.36 71.81 72.18 72.44 71.31 70.80 71.97 70.97 69.80 68.05 67.88 67.55 6/1 6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6/13 6/14 6/15 6/16 6/17 2.68 6.15 4.87 6.08 5.55 2.14 2.35 4.21 2.96 5.10 13.07 12.58 6.00 4.56 5.09 6.27 9.89 81.71 79.55 76.13 73.41 72.83 74.56 80.99 85.01 86.61 89.49 86.75 83.84 87.87 88.69 91.49 94.56 92.59 59.17 59.15 59.73 59.47 59.39 61.28 63.33 61.95 63.65 61.49 62.85 63.47 60.85 61.47 60.59 59.57 60.03 67.05 66.33 65.54 64.49 64.24 65.91 69.16 69.61 71.04 70.70 70.63 70.10 69.87 70.45 70.83 71.21 70.87 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-53 Table 2.3-7c CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level)* (Ultimate Heat Sink Studies) Day/Hour Wind Speedmph Dry Bulb F Dewpoint F Wet Bulb F 6/18 6/19 6/20 6/21 6/22 6/23 6/24 7.70 3.03 5.58 12.41 8.22 3.64 3.82 93.44 92.59 90.53 87.60 82.43 79.72 79.49 59.81 59.17 59.57 60.93 58.69 56.40 55.65 71.00 70.43 70.02 69.83 67.03 64.94 64.48 7/1 7/2 7/3 7/4 7/5 7/6 7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 8.39 7.41 8.64 7.31 7.31 8.75 10.86 8.77 10.34 12.46 9.95 10.70 6.33 3.98 8.95 12.70 5.17 3.60 8.61 5.68 4.75 4.06 8.93 16.32 75.23 73.55 72.88 72.67 71.28 74.37 76.77 79.63 83.07 86.32 89.15 90.61 92.80 95.65 95.01 96.85 96.51 97.15 96.40 91.52 86.08 84.35 81.39 81.47 54.69 54.69 53.95 53.68 53.36 55.44 57.23 58.96 59.71 60.35 61.49 60.37 59.71 59.57 58.67 59.31 59.49 58.72 57.76 58.85 61.33 55.89 59.31 60.35 62.52 61.94 61.31 61.10 60.43 62.61 64.38 66.26 67.77 69.13 70.60 70.45 70.76 71.53 70.90 71.76 71.75 71.56 70.88 69.94 69.58 66.22 67.02 67.62 8/1 8/2 8/3 8/4 8/5 8/6 8/7 8/8 8/9 8/10 8/11 8/12 8/13 8/14 8/15 8/16 8/17 8/18 8/19 8/20 8/21 8/22 8/23 8/24 10.89 10.13 11.19 9.25 8.42 8.80 14.06 13.55 M M

M M

M M

M 5.38 5.44 3.66 3.50 6.68 7.28 9.70 9.48 6.22 80.08 79.65 78.05 76.72 74.67 76.45 79.23 80.37 M M

M M

M M

M 101.23 102.03 102.16 100.85 97.09 92.64 89.25 87.49 83.73 58.21 56.69 55.33 54.43 54.53 55.55 56.88 57.60 M M

M M

M M

M 59.09 58.00 56.56 55.28 56.61 56.40 55.25 53.71 54.29 66.01 65.07 63.83 62.91 62.25 63.40 65.03 65.79 M M

M M

M M

M 72.92 72.64 72.02 71.07 70.54 69.09 67.49 66.21 65.24 *M - Missing data COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-54 Table 2.3-7d CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level)* (Ultimate Heat Sink Studies) Day/Hour Wind Speed mph Dry Bulb F Dewpoint F Wet Bulb F 9/1 9/2 9/3 9/4 9/5 9/6 9/7 9/8 9/9 9/10 9/11 9/12 9/13 9/14 9/15 9/16 9/17 9/18 9/19 9/20 9/21 9/22 9/23 9/24 7.99 5.26 3.95 4.58 3.78 4.00 4.67 9.88 12.03 10.18 8.76 5.78 7.10 4.77 5.17 5.12 3.24 6.10 6.18 7.80 13.30 25.82 17.04 11.05 81.52 79.12 74.91 73.12 72.37 75.28 79.79 83.38 85.49 88.13 92.13 95.52 99.49 102.61 106.40 108.03 109.47 109.15 107.44 101.47 99.31 94.16 94.61 92.37 55.81 56.45 58.32 58.69 57.92 59.49 60.16 60.06 60.00 61.28 62.85 64.40 63.17 62.72 58.77 55.28 55.49 53.07 52.35 57.87 53.15 61.36 59.49 57.57 65.25 64.76 64.35 63.94 63.25 65.12 66.98 68.06 68.69 70.18 72.20 74.02 74.46 75.01 74.23 73.15 73.65 72.58 71.79 72.42 69.69 72.01 71.19 69.58 10/1 10/2 10/3 10/4 10/5 10/6 10/7 10/8 10/9 10/10 10/11 10/12 10/13 10/14 10/15 10/16 10/17 10/18 10/19 10/20 10/21 10/22 10/23 10/24 8.36 12.16 9.19 5.08 1.56 6.53 7.10 4.15 3.89 5.12 3.77 5.74 5.89 5.27 5.30 5.90 9.37 12.21 8.55 5.54 4.26 3.14 7.36 12.76 90.91 85.92 84.24 80.61 80.24 78.27 83.25 86.77 90.64 92.64 95.23 98.32 100.91 103.09 105.20 105.71 104.93 102.48 101.15 98.27 96.21 90.72 91.33 91.49 58.03 59.17 57.28 56.21 58.48 59.55 62.99 62.91 61.09 62.00 63.36 62.40 59.41 59.39 58.91 56.00 54.11 55.88 56.05 56.13 56.59 60.53 57.68 60.48 69.35 68.39 66.88 65.14 66.21 66.15 69.65 70.67 70.83 71.90 73.38 73.73 72.98 73.58 73.96 72.80 71.78 71.81 71.50 70.68 70.27 70.57 69.31 70.77 11/1 11/2 11/3 11/4 11/5 11/6 11/7 11/8 11/9 11/10 11/11 7.86 12.03 14.22 6.62 8.70 7.13 12.45 M 10.14 12.86 14.68 89.61 86.81 88.56 87.60 85.47 85.28 82.37 M 83.96 83.57 82.51 61.65 62.03 61.48 59.81 60.11 60.37 61.23 M 62.40 62.53 63.97 70.83 70.20 70.42 69.25 68.74 68.82 68.39 M 69.53 69.49 70.00 *M - Missing data COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-55 Table 2.3-7e CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level)* (Ultimate Heat Sink Studies) Day/Hour Wind Speed mph Dry Bulb F Dewpoint F Wet Bulb F 11/12 11/13 11/14 11/15 11/16 11/17 11/18 11/19 11/20 11/21 11/22 11/23 11/24 13.48 11.16 11.36 8.17 4.60 4.39 4.27 11.57 9.70 8.24 6.89 10.12 10.69 84.13 87.73 87.76 89.92 94.72 96.19 96.16 89.28 84.99 83.01 82.00 81.97 78.83 64.96 62.91 63.12 61.81 59.97 59.89 58.85 64.05 61.07 60.69 61.09 59.39 57.81 71.06 70.96 71.08 71.00 71.46 71.85 71.33 72.05 69.10 68.28 68.20 67.25 65.38 12/1 12/2 12/3 12/4 12/5 12/6 12/7 12/8 12/9 12/10 12/11 12/12 12/13 12/14 12/15 12/16 12/17 12/18 12/19 12/20 12/21 12/22 12/23 12/24 10.37 7.69 3.17 2.34 5.74 6.75 6.57 4.62 4.23 4.51 5.53 5.53 5.93 6.81 10.87 12.07 15.02 12.21 15.39 13.48 8.45 7.23 9.74 5.68 77.65 76.64 75.87 75.71 73.92 70.51 73.07 76.88 79.71 82.69 84.13 86.43 88.75 90.69 91.31 87.20 86.96 87.39 83.63 81.47 81.76 81.36 79.41 77.73 57.01 56.85 56.32 56.99 58.64 56.51 57.71 59.63 60.93 61.44 61.01 61.65 62.40 62.93 61.73 60.19 62.24 61.36 62.45 60.80 58.77 54.43 44.32 43.97 64.57 64.14 63.59 63.89 64.18 61.81 63.38 65.73 67.38 68.61 68.81 69.86 70.98 71.85 71.37 69.32 70.36 70.00 69.46 67.87 66.86 64.51 59.39 58.63 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-56 Table 2.3-7f 24 Hour HMS Meteorological Profile for August 4, 1961 Hour Dry Bulb Temp Wet Bulb Temp Dew Pt Wind (mph) F F F F 0 1 2 3 4

5 6

7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 82.0 84.0 86.0 85.0 85.0 85.0 86.0 91.0 92.0 96.0 99.0 103.0 107.0 110.0 112.0 112.0 113.0 110.0 108.0 100.0 98.0 96.0 94.0 93.0 61.0 62.0 63.0 63.0 63.0 62.0 61.0 63.0 63.0 64.0 65.0 67.0 69.0 70.0 71.0 71.0 72.0 70.0 68.0 66.0 66.0 66.0 65.0 64.0 45.0 46.0 48.0 49.0 48.0 46.0 43.0 42.0 42.0 41.0 42.0 44.0 45.0 46.0 48.0 48.0 49.0 45.0 43.0 45.0 45.0 46.0 46.0 45.0 4 5 5 5 5

3 8

7 6

6 7

6 6

5 6

5 5

8 14 19 20 18 16 12 24 Hour Average: Dry Bulb = 96.96 F Wet Bulb = 65.62 F Dew Point = 45.29 F Wind = 8.37 mph COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-57 Table 2.3-7g Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing Second Through Thirtieth Day Pond Thermal Performance (Based On July 9 - August 8, 1961 Hourly Hanford Meteorological Station Data) Hour Dry Bulb (F) Wet Bulb (F) 1 2 3

4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 70.2 68.8 68.3 68.8 70.2 72.5 75.6 79.0 82.8 86.6 90.1 93.1 95.4 96.8 97.3 96.8 95.4 93.1 90.1 86.6 82.8 79.0 75.6 72.5 56.5 56.0 55.8 56.0 56.5 57.3 58.4 59.6 61.0 62.3 63.6 64.7 65.5 66.0 66.2 66.0 65.5 64.7 63.6 62.3 61.0 59.6 58.4 57.3 Daily Average and Variation 82.8 +/- 14.5°F 61.0 +/- 5.2°F COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-58 Table 2.3-7h Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing First Through Thirtieth Day Maximum Mass Loss (Based On July 2 - August 1, 1960 Hourly Hanford Meteorological Station Data) Hour Dry Bulb (F) Wet Bulb (F) 1 2 3

4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 69.4 67.8 67.3 67.8 69.4 71.9 75.1 78.9 82.9 86.9 90.7 93.9 96.4 98.0 98.5 98.0 96.4 93.9 90.7 86.9 82.9 78.9 75.1 71.9 53.3 52.6 52.4 52.6 53.3 54.3 55.7 57.3 59.0 60.7 62.3 63.7 64.7 65.4 65.6 65.4 64.7 63.7 62.3 60.7 59.0 57.3 55.7 54.3 Daily Average and Variation 82.9 +/- 15.6°F 59.0 +/- 6.6°F

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-59Table 2.3-8a Summary of CGS Onsite Meteorological Data Collected During the First and Second Annual Cycles as Compared to Corresponding Hanford Meteorological Station Data (Historical HMS Data Indicated for Each Month) April May June July August September October Site and Sensor Elevation '74 '75 '74 '75 '74 '75 '74 '75 '74 '75 '74 '75 '74 '75 1. Prevailing Wind Direction CGS 33'HMS 50' HMS (hist) 50' (1955-1970)

WNW SSW WNW N/A WNW SSW NW WNW N/A WNW WNW NW WNW N/A WNW S S WNW N/A WNW S S WNW N/A WNW N N NW N/A NW WNW S NW NWWNW 2. Mean Wind Speed (mph) CGS 33' HMS 50' HMS (hist) 50' (1955-1970) 9.8 8.0 10.3 9.0 9.0 8.4 8.7 9.0 9.6 8.8 8.5 9.3 9.0 10.5 9.2 7.2 7.6 8.1 8.5 8.6 6.8 7.9 7.5 9.0 8.0 6.5 5.7 7.1 6.8 7.5 4.8 7.2 5.6 7.1 6.7 3. Mean Dry Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 52.2 47.6 52.5 48.4 52.5 57.4 59.6 57.9 60.7 61.8 72.5 66.1 73.3 67.3 69.9 73.6 78.7 74.8 80.0 77.5 74.7 70.3 76.3 71.2 75.3 66.9 66.2 68.3 67.9 67.0 51.7 52.1 52.0 52.353.2 4. Mean Wet Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 44.7 39.7 43.9 40.0 42.8 47.2 48.2 46.5 49.0 49.1 56.0 52.7 54.5 54.0 54.5 57.4 61.5 56.3 62.0 57.9 58.0 55.7 57.0 56.0 57.3 52.6 52.0 52.0 52.0 52.6 43.8 45.3 42.0 45.045.4 5. Mean Dew Point Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 36.6 29.8 33.3 30.0 30.4 36.6 36.9 34.0 38.6 36.0 43.0 40.8 38.2 42.4 41.2 44.9 50.2 41.0 50.1 42.3 45.6 44.2 43.2 44.6 42.8 39.9 39.5 38.9 38.2 39.5 35.0 38.2 31.0 37.236.9 6. Total Precipitation (inches) CGS HMS HMS (hist) 1946-1970 Mean Total N/A - Not Available

.55 .53

.46 .42 .44

.44 .47

.28 .38 .50

.06 .46

.12 .14 .66

.45 .09

.71 .32 .16 0.0 1.17 Trace 1.16 .21

.06 0.0

.01 .03 .30

.10 .74

.21 .87 .61 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-60Table 2.3-8a Summary of CGS Onsite Meteorological Data Collected During the First and Second Annual Cycles as Compared to Corresponding Hanford Meteorological Station Data (Historical HMS Data Indicated for Each Month) (Continued) First AnnualCycle Second AnnualCycle November December January February March Site and Sensor Elevation '74 '75 '74 '75 '75 '76 '75 '76 '75 '76 April '74-March '75 April '75- March '76 1. Prevailing Wind Direction CGS 33' HMS 50' HMS (hist) 50' (1955-1970)

SSW S NW NW NW S NWNW NW NW NNW NWNW NWSW NW NW SSWNW NW SW NW NNW SSWWNW NW SW WNW NW NW N/A N/A NW ('55 -'70) 2. Mean Wind Speed (mph) CGS 33' HMS 50' HMS (hist) 50' (1955-1970) 5.8 7.8 5.5 7.7 6.2 6.4 7.1 5.9 7.2 6.0 6.4 5.0 6.4 4.9 6.4 7.8 10.4 7.5 10.8 7.0 8.7 9.1 8.9 9.6 8.4 7.2 7.8 9.1 10.1 7.6 ('55 - '70) 3. Mean Dry Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 42.1 39.5 42.1 39.3 40.1 36.8 34.2 35.7 34.5 33.4 32.3 32.4 32.0 31.5 30.3 33.8 37.7 33.6 37.3 37.5 41.9 40.8 42.0 40.6 44.0 53.1 52.1 53.4 52.6 53.5 ('50 - '70) 4. Mean Wet Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 39.3 35.5 38.0 35.0 36.4 34.5 31.9 33.0 32.0 31.2 30.0 30.6 30.0 30.0 27.9 30.9 32.9 31.0 33.0 33.6 36.2 34.4 36.0 35.0 37.3 44.3 43.4 43.4 43.6 43.8 ('50 - '70) 5. Mean Dew Point Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 36.3 30.6 33.9 30.0 31.1 31.4 28.9 29.2 28.1 27.5 26.3 28.1 26.0 27.6 23.2 26.5 25.4 25.5 25.5 27.4 27.9 24.8 26.0 25.0 27.3 35.9 34.8 33.4 34.8 33.8 ('50 - '70) 6. Total Precipitation (inches) CGS HMS HMS (hist) 1946-1970 Mean Total N/A - Not Available .56 .70

.71 .60 .80 .67 .03 .97 .70 .81 .93 .08 1.43 .56 .97 .67 .11 .98 .36 .58 .52 .16 .33 .23 .38 4.92 4.54 6.21 5.87 6.53 ('46 - '70)

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-61 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) APRIL SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 5 2 8 15 6 4 0 0 0 0 0 0 0 1 19 22 ENEE0 0 1 3 2 3 0 0 0 0 0 0 0 0 0 0 3 6 ESESE0 0 6 4 4 12 1 6 0 1 0 0 0 0 0 0 11 23 SSES0 0 4 8 26 18 21 19 0 12 0 0 0 0 3 7 54 64 SSWSW0 0 4 4 16 18 29 9 30 15 2 4 0 0 13 6 94 56 WSWW0 0 3 3 10 14 12 16 5 17 3 4 1 1 7 8 41 63 WNWNW0 0 7 5 19 23 26 15 40 9 21 11 8 3 2 1 123 67 NNWN0 0 5 3 17 14 5 5 1 1 0 0 0 0 2 0 30 23 VARCALM0 0 2 0 5 0 0 0 0 0 0 0 0 0 0 0 7 0 UNKNOTOTAL0 0 0 69 0 224 0 176 0 131 0 45 0 13 14 64 14 720 MAY SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 5 7 11 3 0 3 0 0 0 0 0 0 0 0 16 13 ENEE0 0 1 8 6 6 2 0 0 0 0 0 0 0 0 0 9 14 ESESE0 0 6 1 9 16 0 1 0 0 0 0 0 0 0 0 15 18 SSES0 0 9 10 38 27 13 45 0 10 0 0 0 0 0 0 60 92 SSWSW0 0 5 3 30 15 49 18 16 13 4 3 2 0 0 0 106 52 WSWW0 0 6 3 19 23 30 35 13 13 1 5 0 0 0 0 69 79 WNWNW0 0 11 4 24 14 34 10 17 13 10 4 0 2 0 0 96 47 NNWN0 0 3 4 13 7 7 1 0 0 0 0 0 0 0 0 23 12 VARCALM0 0 7 0 8 0 0 0 0 0 0 0 0 0 0 0 15 0 UNKNOTOTAL0 0 0 93 0 269 0 248 0 95 0 27 0 4 8 8 8 744 JUNE SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 5 7 12 9 1 4 0 0 0 0 0 0 0 1 18 21 ENE E 0 0 6 3 16 14 9 7 0 0 0 0 0 0 0 0 31 24 ESE SE 0 0 4 4 16 23 6 10 0 0 0 0 0 0 0 0 26 37 SSE S 0 0 7 4 34 20 11 18 0 10 0 2 0 0 0 1 52 55 SSW SW 0 0 6 3 20 11 12 6 12 4 1 5 0 0 0 0 51 29 WSW W 0 0 3 2 15 18 5 14 3 13 1 2 1 3 0 0 28 52 WNW NW 0 0 2 3 24 15 19 20 10 8 10 5 2 2 0 0 67 53 NNW N 0 0 6 6 17 11 3 1 0 0 0 0 0 0 0 0 26 18 VAR CALM 0 0 0 0 4 0 0 0 1 0 0 0 0 0 0 0 5 0 UNKNO TOTAL 0 0 10 81 38 317 26 172 9 70 0 26 0 8 44 46 127 720 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-62 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) JULY SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 3 11 13 12 2 1 0 0 0 0 0 0 0 0 18 24 ENE E 0 0 3 10 9 14 6 6 0 0 0 0 0 0 0 0 18 30 ESE SE 0 0 6 10 18 26 1 4 0 0 0 0 0 0 0 0 25 40 SSE S 0 0 3 6 37 27 16 32 1 5 0 0 0 0 0 0 57 70 SSW SW 0 0 9 7 16 22 18 14 9 6 2 0 0 1 0 0 54 50 WSW W 0 0 6 7 12 14 11 19 3 9 1 0 2 0 0 0 35 49 WNW NW 0 0 5 11 18 18 18 21 17 13 5 4 0 0 0 0 63 67 NNW N 0 0 10 8 25 22 4 5 2 0 0 0 0 0 0 0 41 35 VAR CALM 0 0 5 0 24 0 3 0 0 0 0 0 0 0 0 0 32 0 UNKNO TOTAL 0 0 0 120 0 327 0 181 0 65 0 12 0 3 36 36 36 744 AUGUST SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 16 12 21 19 11 6 0 3 0 2 0 0 0 0 48 42 ENE E 0 0 9 10 6 4 0 4 0 0 0 0 0 0 0 0 15 18 ESE SE 0 0 12 6 9 25 0 1 0 0 0 0 0 0 0 0 21 32 SSE S 0 0 8 7 39 33 16 28 0 4 0 3 0 0 0 0 63 75 SSW SW 0 0 11 8 24 16 17 8 13 0 1 1 0 0 0 0 66 33 WSW W 0 0 9 4 18 13 1 6 0 3 0 0 0 0 0 0 28 26 WNW NW 0 0 8 12 19 27 13 12 22 8 10 8 1 0 0 0 73 67 NNW N 0 0 4 15 35 32 10 10 0 0 0 0 0 0 0 0 49 57 VAR CALM 0 0 12 0 5 0 1 0 0 0 0 0 0 0 0 0 18 0 UNKNO TOTAL 0 0 0 163 0 345 0 144 0 53 0 25 0 1 13 13 13 744 SEPTEMBER SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 19 21 29 11 10 5 11 2 0 0 0 0 0 0 69 39 ENE E 0 0 20 17 20 7 0 0 0 0 0 0 0 0 0 0 40 24 ESE SE 0 0 15 7 11 11 1 3 0 0 0 0 0 0 0 0 27 21 SSE S 0 0 1 8 13 22 7 25 0 4 0 0 0 0 0 0 21 59 SSW SW 0 0 5 12 18 11 11 3 3 3 1 0 0 0 0 0 38 29 WSW W 0 0 8 12 5 10 3 10 1 4 0 0 0 0 0 0 17 36 WNW NW 0 0 9 9 12 19 17 24 12 8 5 4 1 1 0 0 56 65 NNW N 0 0 12 15 29 38 14 28 3 12 0 0 1 0 0 0 59 93 VAR CALM 0 0 10 0 8 0 1 0 0 0 0 0 0 0 0 0 19 0 UNKNO TOTAL 0 0 0 200 0 274 0 162 0 63 0 10 0 3 8 8 8 720 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-63 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) OCTOBER SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 26 26 15 17 1 0 0 0 0 0 0 0 0 0 42 43 ENE E 0 0 26 20 22 4 1 0 0 0 0 0 0 0 0 0 49 24 ESE SE 0 0 15 15 2 19 0 2 0 0 0 0 0 0 0 0 17 36 SSE S 0 0 16 13 21 25 8 13 0 0 0 0 0 0 0 0 45 51 SSW SW 0 0 15 12 21 13 6 1 0 0 0 0 0 0 0 0 42 26 WSW W 0 0 15 12 11 9 2 10 0 5 0 1 0 0 0 0 28 37 WNW NW 0 0 21 17 11 17 15 12 11 7 6 0 0 0 0 0 64 53 NNW N 0 0 29 37 20 24 9 3 2 0 0 0 0 0 0 0 60 64 VAR CALM 0 1 16 0 4 0 0 0 0 0 0 0 0 0 0 0 20 1 UNKNO TOTAL 0 1 0 331 0 255 0 83 0 25 0 7 0 0 42 42 42 744 NOVEMBER SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 18 10 14 13 4 2 0 0 0 0 0 0 2 1 38 26 ENE E 0 0 13 6 10 2 7 0 0 0 0 0 0 0 1 0 31 8 ESE SE 0 0 12 14 3 13 0 7 0 0 0 0 0 0 0 0 15 34 SSE S 0 0 7 12 28 29 15 29 3 5 0 0 0 0 0 0 53 75 SSW SW 0 0 11 12 32 20 14 6 19 8 1 4 0 0 0 0 77 50 WSW W 0 0 9 12 6 14 5 3 2 1 2 2 0 0 0 3 24 35 WNW NW 0 0 22 27 14 34 7 12 5 0 1 1 0 0 2 1 51 75 NNW N 0 0 24 30 34 17 2 3 0 0 0 0 0 0 0 0 60 50 VAR CALM 0 0 11 0 2 0 0 0 0 0 0 0 0 0 0 0 13 0 UNKNO TOTAL 0 0 0 250 0 285 0 116 0 43 0 11 0 0 5 15 5 720 DECEMBER SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 12 9 3 5 2 2 0 0 0 0 0 0 0 0 17 16 ENE E 0 0 5 6 4 1 0 0 0 0 0 0 0 0 0 0 9 7 ESE SE 0 0 8 9 1 6 1 5 0 1 0 0 0 0 0 0 10 21 SSE S 0 0 5 11 26 39 25 35 3 14 1 1 0 0 0 0 60 100 SSW SW 0 0 14 14 23 11 29 9 9 2 4 0 3 0 0 0 82 36 WSW W 0 0 16 20 17 15 6 7 3 3 2 3 1 4 0 0 45 52 WNW NW 0 0 27 17 25 59 21 11 6 3 1 0 1 0 0 1 81 91 NNW N 0 0 29 21 27 12 6 0 0 1 0 0 0 0 0 0 62 34 VAR CALM 0 0 8 0 3 0 1 0 0 0 0 0 0 0 0 0 12 0 UNKNO TOTAL 0 0 0 231 0 277 0 160 0 45 0 12 0 9 9 10 9 744 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-64 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) JANUARY SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 11 13 17 11 6 4 0 0 0 0 0 0 0 0 34 28 ENE E 0 0 10 5 12 10 5 1 0 0 0 0 0 0 6 2 33 18 ESE SE 0 0 15 10 5 14 2 1 0 0 0 1 0 0 1 1 23 27 SSE S 0 0 13 10 17 14 15 16 2 6 1 0 0 0 0 0 48 46 SSW SW 0 0 6 15 18 14 10 5 15 7 3 4 0 2 0 1 52 48 WSW W 0 0 13 8 16 8 4 8 3 4 6 0 3 0 0 0 45 28 WNW NW 0 0 23 20 14 37 13 19 0 3 0 0 0 0 1 10 51 89 NNW N 0 0 29 11 47 17 22 15 0 0 0 0 0 0 4 1 102 44 VAR CALM 0 0 7 0 3 0 1 0 0 0 0 0 0 0 0 0 11 0 UNKNO TOTAL 0 0 0 219 0 274 0 147 0 40 0 15 0 5 17 44 17 744 FEBRUARY SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 15 8 15 8 2 0 0 0 0 0 0 0 0 0 32 16 ENEE0 0 5 4 8 2 0 0 0 0 0 0 0 0 0 0 13 6 ESESE0 0 5 6 5 10 1 3 0 1 0 0 0 0 0 0 11 20 SSES0 0 14 14 20 11 13 18 4 8 1 2 0 0 0 0 52 53 SSWSW0 0 9 4 8 9 10 3 9 9 18 4 1 4 0 0 55 33 WSWW0 0 9 4 7 11 3 6 7 1 4 1 1 1 0 0 31 24 WNWNW0 0 7 12 14 54 9 45 2 10 2 3 1 2 0 0 35 126 NNWN0 0 14 16 45 19 24 19 14 1 0 0 0 0 0 0 97 55 VARCALM0 0 5 0 2 0 1 0 0 0 0 0 0 0 0 0 8 0 UNKNOTOTAL0 0 0 151 0 248 0 157 0 66 0 35 0 10 5 5 5 672 MARCH SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 6 5 8 4 5 1 2 0 0 0 0 0 0 0 21 10 ENE E 0 0 4 6 4 2 1 2 0 0 0 0 0 0 0 0 9 10 ESE SE 0 0 9 2 5 6 1 7 0 3 0 0 0 0 0 0 15 18 SSE S 0 0 5 3 24 28 22 35 3 13 0 0 0 0 0 0 54 79 SSW SW 0 0 1 5 15 9 24 14 16 31 6 14 0 0 0 0 62 73 WSW W 0 0 4 1 7 12 12 2 8 0 6 1 0 0 0 0 37 16 WNW NW 0 0 6 13 21 32 19 27 2 6 0 1 4 4 0 0 52 83 NNW N 0 0 9 11 37 18 23 6 12 9 5 0 0 0 0 0 86 44 VAR CALM 0 0 7 0 5 0 0 0 0 0 0 0 0 0 0 0 12 0 UNKNO TOTAL 0 0 0 97 0 237 0 201 0 105 0 33 0 8 63 63 63 744 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-65 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) ANNUAL SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 141 131 166 127 50 32 13 5 0 2 0 0 2 3 372 300 ENEE0 0 103 98 119 69 31 20 0 0 0 0 0 0 7 2 260 189 ESESE0 0 113 88 88 181 14 50 0 6 0 1 0 0 1 1 216 327 SSES0 0 92 106 323 293 182 313 16 91 3 8 0 0 3 8 619 819 SSWSW0 0 96 99 241 169 229 96 151 98 43 39 6 7 13 7 779 515 WSWW0 0 101 88 143 161 94 136 48 73 26 19 9 9 7 11 428 497 WNWNW0 0 148 150 215 349 211 228 144 88 71 41 18 14 5 13 812 883 NNWN0 0 174 177 346 231 129 96 34 24 5 0 1 0 6 1 695 529 VARCALM0 1 90 0 73 0 8 0 1 0 0 0 0 0 0 0 172 1 UNKNOTOTAL0 0 10 2005 38 3332 26 1945 9 801 0 258 0 64 264 354 347 8760 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-66Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) JANUARY SPEED CLASS (MPH) FEBRUARY SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTALAVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.8 2.0 1.8 1.3 1.8 1.8 2.7 1.6 1.4 1.2 1.4 1.4 1.8 2.4 3.6 3.0 1.3 5.4 1.2 0.8 0.7 0.5 0.6 0.7 1.5 0.8 0.9 1.0 1.4 1.5 2.3 5.6 7.8 2.8 0.1 0.2 0.4 0.2 0.1 0.1 0.2 0.4 0.3 0.4 0.6 1.4 1.7 1.3 5.1 6.6 0.6 0.3 0.1 0.1

0.1 0.2 0.1 0.5 1.0 1.6 0.8 10.6 0.9 1.2 0.1 0.2 0.1 0.1

1. #

0.1 0.2 0.6 0.7 0.4 0.1

0.1

1. #

1. 0.1 0.3 0.3 0.2 #

0.1 0.1

1. 4.7 3.4 2.9 1.9 2.4 2.8 4.8 2.9 3.6 4.8 6.8 6.0 6.1 14.0 19.3 6.5 1.4 5.4 4.3 4.6 4.4 3.0 3.0 3.4 4.0 5.4 7.7 11.5 10.7 8.9 6.3 7.1 6.9 4.2 1.8 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.6 1.8 2.2 1.3 1.3 1.3 1.9 1.2 1.3 1.0 1.0 0.9 1.6 1.9 3.3 2.3 1.3 2.4 1.6 1.3 0.9 0.6 0.7 0.7 1.1 0.8 0.7 1.0 1.6 2.1 3.4 4.9 6.9 2.5 0.2 0.4 0.8 0.2 0.1

0.1 0.3 0.4 0.4 0.8 1.3 2.1 2.9 6.8 6.4 0.8

1. 0.2 0.4 0.2

0.1 0.2 0.3 0.6 1.8 1.4 1.1 1.5 1.5 0.1 #

0.1

0.1 0.5 1.1 0.5 0.2 0.3 0.2

1. #

0.1

0.1 0.2 0.5 0.3 0.1 0.1 0.1

0.1 0.1 0.1

1. 4.8 4.5 3.5 1.9 2.0 2.1 3.4 2.6 2.9 4.2 7.4 7.4 9.3 15.5 18.4 5.7 1.5 2.4 4.5 6.3 3.8 3.3 3.0 3.3 4.0 5.2 6.6 10.5 12.6 10.5 7.8 8.3 7.3 4.8 1.8 TOTAL 38.7 30.1 19.6 7.6 2.6 0.9 0.2 # 100.0 6.2 TOTAL 30.6 31.0 23.8 9.4 3.0 1.5 0.3 100.0 7.1

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05% MARCH SPEED CLASS (MPH) APRIL SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.9 1.4 1.7 0.7 0.9 1.0 1.4 0.6 1.0 0.6 0.8 0.8 1.1 1.1 1.5 1.4 1.3 0.7 1.8 1.6 1.2 0.8 0.8 1.1 1.7 1.1 1.4 1.3 2.0 2.5 3.9 4.4 4.4 2.4 0.2 1.0 0.9 0.3 0.1 0.2 0.2 0.5 0.8 0.7 1.1 2.0 3.0 3.1 5.8 5.3 1.1

1. 0.2 0.6 0.2

0.1 0.1 0.3 0.4 1.2 2.5 2.5 1.2 2.2 1.8 0.2 #

0.1

1. #

0.2 0.7 1.5 1.0 0.2 0.8 0.6

1. #

0.3 0.8 0.4 0.1 0.1 0.1

0.1 0.2 0.2

1. 4.9 4.5 3.5 1.6 1.9 2.4 3.7 2.8 3.7 5.3 9.8 10.4 9.6 14.4 13.7 5.1 1.5 0.7 5.4 6.8 4.8 5.0 4.2 4.4 5.0 7.1 7.4 12.1 13.5 11.7 8.2 9.5 8.9 5.6 2.1 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.6 1.0 1.4 0.6 0.8 0.8 1.0 0.5 0.7 0.7 0.7 0.8 1.1 0.8 1.2 0.9 1.6 0.5 1.6 1.3 1.2 1.0 1.0 1.0 1.5 1.0 1.4 1.5 2.3 2.6 4.2 3.9 3.7 1.9 0.5 0.7 0.6 0.4 0.2 0.5 0.2 0.5 0.8 0.7 1.1 2.1 3.8 4.3 6.0 4.2 0.6 0.3 0.3 0.2 0.1

0.1 0.2 0.3 0.9 2.1 2.5 1.7 4.2 3.2 0.2 #

0.1

0.1 0.4 1.6 1.1 0.5 1.3 1.5

1. #

0.1 0.6 0.4 0.1 0.3 0.4

0.1 0.1

1. # 4.2 3.3 3.2 1.9 2.3 2.0 3.1 2.5 3.2 4.7 9.5 11.3 11.9 16.5 14.2 3.6 2.1 0.5 5.5 6.8 5.3 5.2 5.0 4.5 5.2 6.8 6.7 9.6 12.7 11.4 8.8 11.0 11.0 5.8 2.7 TOTAL 19.9 32.6 26.1 13.5 5.1 1.8 0.5 100.0 8.6 TOTAL 16.7 31.6 26.7 16.3 6.6 1.9 0.2 100.0 9.1

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-67Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) (Continued) MAY SPEED CLASS (MPH) JUNE SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTALAVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEEDN NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.2 0.6 1.0 0.8 0.9 0.9 1.0 0.6 0.6 0.7 0.6 0.9 1.2 0.8 1.2 1.0 1.9 0.6 1.7 1.4 1.5 1.1 1.2 1.0 1.5 1.3 1.7 1.3 2.4 2.7 4.0 3.9 3.6 1.8 1.3 0.9 0.7 1.0 0.3 0.3 0.3 0.6 0.6 0.5 0.8 1.7 3.5 4.4 6.7 4.9 0.7

1. 0.1 0.3 0.1 0.1

0.1 0.2 0.1 0.4 1.1 1.8 1.6 4.7 4.4 0.1 #

0.1

0.1 0.5 0.7 0.2 1.7 2.6

0.1 0.2

0.2 0.5

1. #

1. 3.9 3.0 3.7 2.3 2.4 2.2 3.2 2.7 2.9 3.3 6.4 9.8 11.4 18.0 17.2 3.6 3.2 0.6 5.7 6.7 6.4 5.0 4.7 4.6 5.4 6.4 5.6 7.4 9.6 10.1 8.3 11.2 12.0 5.5 3.2 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 0.9 0.6 0.8 0.4 0.5 0.6 0.7 0.5 0.6 0.4 0.7 0.6 0.7 0.6 0.7 0.6 1.6 0.3 2.0 1.8 1.4 1.0 1.3 1.3 1.6 1.1 1.7 1.5 2.5 2.5 4.1 3.5 3.7 2.0 1.7 0.9 0.8 0.8 0.4 0.3 0.3 0.4 0.4 0.3 0.7 2.0 3.5 4.4 6.9 5.1 0.8

1. 0.2 0.4 0.5 0.1

0.1 0.1 0.2 1.0 1.5 1.6 6.2 5.4 0.1 #

0.1

1. 0.1 0.3 0.4 0.3 2.1 3.4

0.1

0.4 0.7

1. #

1. 4.0 3.6 3.6 1.9 2.1 2.2 2.7 2.1 2.7 2.9 6.5 8.6 11.1 19.7 19.0 3.5 3.3 0.3 6.0 7.1 7.5 6.5 5.6 5.0 5.2 5.8 5.5 7.3 8.8 9.7 8.8 12.1 13.0 6.3 3.4 TOTAL 16.5 33.4 27.9 15.1 5.9 1.0 # 100.0 8.7 TOTAL 11.8 34.7 28.0 17.4 6.7 1.2 100.0 9.3

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05% JULY SPEED CLASS (MPH) AUGUST SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.1 0.7 0.9 0.5 0.7 0.7 0.9 0.4 0.7 0.5 0.8 0.7 1.0 0.7 0.9 0.8 2.6 0.4 2.6 2.1 2.1 1.2 1.5 1.3 1.7 1.0 1.5 1.3 2.3 3.0 4.4 4.2 3.8 2.0 1.8 0.6 0.8 0.5 0.2 0.3 0.3 0.3 0.4 0.2 0.5 1.7 2.8 3.5 7.7 5.6 0.7

1. 0.1 0.2 0.2

1. #

0.1 0.2 1.0 1.4 0.9 4.8 5.1 0.1

0.4 0.4 0.1 1.8 3.0

0.1 0.2

0.2 0.5

1. 4.4 3.8 3.7 1.9 2.5 2.3 2.9 1.8 2.5 2.5 6.3 8.5 9.9 19.4 18.9 3.6 4.4 0.4 5.3 6.0 5.7 5.0 4.9 4.9 4.9 5.6 5.3 6.5 9.1 9.5 7.7 11.2 12.4 5.8 3.3 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.3 1.0 1.3 0.7 0.9 0.8 1.1 0.7 0.8 0.6 1.0 0.9 1.3 0.9 1.2 1.0 2.8 0.6 2.5 1.8 1.6 1.1 1.3 1.6 1.8 1.1 1.4 1.6 2.7 3.2 5.1 4.1 3.8 2.3 1.3 0.4 0.5 0.3 0.1 0.2 0.3 0.5 0.6 0.3 0.7 1.6 2.9 4.1 7.6 5.1 0.5 0.1 0.1 0.1

1. #

0.2 0.8 1.4 0.7 4.1 4.5 0.1

1. 0.1 0.2 0.1

1.3 2.3

0.1 0.1 0.2 0.5

1. 4.3 3.4 3.3 1.9 2.4 2.7 3.4 2.4 2.5 3.2 6.4 8.6 11.2 18.2 17.4 3.9 4.1 0.6 5.0 5.1 4.4 4.3 4.5 4.7 4.8 5.5 4.8 6.6 8.1 8.5 7.5 10.6 11.8 5.4 3.0 TOTAL 15.0 37.8 26.1 14.1 5.7 1.0 100.0 8.6 18.9 38.3 25.7 12.1 4.0 0.9 # 100.0 7.9

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-68Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) (Continued) SEPTEMBER SPEED CLASS (MPH) OCTOBER SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEEDDIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.9 1.5 1.8 1.3 1.6 1.2 1.4 0.9 0.9 0.8 0.8 1.0 1.3 1.2 1.4 1.3 2.0 1.2 2.4 1.8 1.8 0.9 1.1 1.5 2.1 1.3 1.3 1.6 2.1 3.0 4.9 4.0 3.6 2.6 0.6 0.9 1.0 0.6 0.1 0.2 0.2 0.4 0.5 0.3 0.5 1.3 2.7 3.7 5.6 4.9 0.9 0.3 0.4 0.3 0.1

1. #

0.1 0.1 0.2 1.0 1.3 0.8 2.9 3.3 0.2 #

0.1 0.1

0.1 0.5 0.6 0.3 0.9 1.4

1. #

0.1 0.3 0.1 0.1 0.1 0.2

1. 5.5 4.8 4.6 2.4 2.9 2.9 3.9 2.8 2.6 3.3 6.0 8.7 11.1 14.7 14.8 5.0 2.6 1.2 5.3 6.4 5.6 3.9 3.7 4.1 4.6 5.3 5.2 7.0 9.9 9.4 7.6 9.8 10.5 5.7 2.6 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.6 2.1 2.4 1.4 1.8 1.8 2.5 1.0 1.1 1.0 1.0 1.0 1.7 1.7 2.4 2.1 1.6 2.7 1.7 1.1 0.8 0.7 0.9 1.4 1.9 1.5 1.4 1.4 2.0 2.8 4.6 4.7 4.4 2.5 0.1 0.4 0.3 0.2 0.1 0.1 0.1 0.6 0.7 0.5 0.7 1.5 3.0 3.6 5.0 4.0 0.6

1. 0.1 0.1 0.1

0.1 0.1 0.3 0.7 1.4 1.6 0.7 1.4 1.6 0.1

0.2 0.5 1.0 0.6 0.1 0.4 0.4

0.2 0.4 0.1

0.1

1. 4.8 3.6 3.5 2.2 2.8 3.3 5.1 3.3 3.5 4.5 7.3 9.1 10.7 13.2 12.9 5.3 1.7 2.7 3.9 3.9 3.5 3.6 3.1 3.6 4.2 5.7 6.7 9.7 11.3 9.5 7.1 8.1.

8.0 4.7 1.8 TOTAL 23.5 36.6 23.8 11.0 4.0 0.9 100.0 7.5 TOTAL 31.9 33.9 21.4 8.3 3.2 0.8 # # 100.0 6.7

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05% NOVEMBER SPEED CLASS (MPH) DECEMBER SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.7 2.2 1.9 1.8 1.9 2.0 2.5 1.4 1.7 1.4 1.6 1.3 2.1 2.5 3.6 3.0 1.4 4.7 1.3 0.7 0.5 0.4 0.6 1.0 1.4 1.2 1.2 1.2 1.6 2.1 3.4 4.6 5.9 2.8 0.1 0.4 0.4 0.1

0.1 0.3 0.4 0.5 0.8 1.4 1.9 1.9 4.9 4.7 1.0 0.2 0.2

0.1 0.2 0.5 0.9 1.5 1.3 0.6 1.0 0.7 0.2 #

0.1 0.3 0.7 0.8 0.4 0.1 0.3 0.1

1. #

0.2 0.3 0.1 0.1 0.1 0.1

0.1 0.1

1. #

1. 4.6 3.5 2.5 2.2 2.5 3.1 4.3 3.3 4.2 5.3 7.3 7.1 8.2 13.4 15.1 7.0 1.5 4.7 4.0 4.0 2.8 2.5 2.6 3.1 3.9 5.3 6.8 9.9 10.5 9.1 6.8 7.5 6.6 4.6 1.6 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.7 1.6 1.7 1.5 1.6 1.9 2.6 1.7 1.7 1.3 1.5 1.6 2.1 2.9 3.8 2.9 1.5 6.8 1.0 0.6 0.5 0.5 0.6 0.7 1.2 1.2 0.8 0.7 1.3 1.8 2.7 5.7 7.3 2.4 0.1 0.3 0.2

0.1 0.2 0.4 0.2 0.4 0.6 1.2 1.7 1.5 5.3 6.0 0.9 0.2

1. #

0.1 0.1 0.2 0.4 0.8 1.4 1.1 0.5 0.8 1.0 0.1

1. # 0.1 0.2 0.5 1.0 0.4 0.1 0.1 0.1

0.1 0.4 0.5 0.1

0.1 0.1

1. 4.2 2.4 2.2 2.0 2.3 2.9 4.3 3.4 3.6 4.4 7.0 6.7 6.9 14.8 18.2 6.3 1.6 6.8 3.5 3.6 2.6 2.4 2.9 3.6 3.6 4.7 6.7 11.1 11.8 8.6 6.0 6.9 6.7 4.3 1.7 TOTAL 39.7 30.0 18.8 7.4 2.8 0.9 0.2 # 100.0 6.1 TOTAL 41.4 29.1 19.0 6.7 2.5 1.1 0.2 # # 100.0 5.9

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-69Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) (Continued) COMPOSITE OF ALL MONTHS SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTALAVG SPEED N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW VAR CALM 2.0 1.4 1.6 1.0 1.2 1.2 1.6 0.9 1.0 0.9 1.0 1.0 1.4 1.5 2.1 1.7 1.7 2.2 1.8 1.4 1.2 0.8 1.0 1.1 1.6 1.1 1.3 1.3 2.0 2.5 3.9 4.5 4.9 2.3 0.7 0.6 0.6 0.4 0.2 0.2 0.2 0.4 0.5 0.4 0.7 1.6 2.7 3.2 6.1 5.2 0.8 # 0.2 0.3 0.2 # # # 0.1 0.1 0.2 0.6 1.4 1.6 1.0 2.9 2.8 0.1 #

1. # # # # # # 0.1 0.3 0.8 0.5 0.2 0.9 1.3 # #

1. # #

1. # 0.2 0.3 0.2 # 0.1 0.3 #

1. 0.1 # # # # #

1. # #

1. 4.6 3.7 3.4 2.0 2.4 2.5 3.7 2.0 3.0 4.0 7.2 8.5 9.7 16.0 16.6 4.9 2.4 2.2 4.9 5.7 4.9 4.1 3.9 4.0 4.5 5.7 6.4 9.5 10.9 9.9 7.7 9.7 9.6 5.1 2.7 TOTAL 25.4 33.4 23.8 11.5 4.1 1.1 0.1 # # 100.0 7.6 # DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-70Table 2.3-10 Percent Frequency of Occurrence of Wind Direction at the Hanford Reservation* WIND DIRECTION MONTH/YEAR/SITE/ELEVATION NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW N VARI-ABLE CALM 4/74 CGS 33' 4/74 CGS (temp) 23' 4/74 HMS 50' April (1955-1970) HMS (hist) 50' 2.64 2.64 1.53 3.2 3.06 3.61 2.36 3.2 0.42 1.11 1.25 2.0 0.83 1.81 1.53 2.3 1.53 3.75 1.94 2.0 3.19 4.72 2.64 3.1 7.50 6.81 2.50 2.5 8.89 10.42 1.81 3.2 13.06 6.11 3.61 4.7 7.78 4.31 6.81 9.5 5.69 4.72 15.28 11.2 8.75 10.28 13.19 11.8 17.08 16.11 22.08 16.6 9.31 7.50 17.08 14.3 4.17 2.36 2.78 3.7 3.19 2.92 1.53 4.2 0.97 3.19 1.67 2.1 0.00 0.00 0.42 0.4 5/74 CGS 33' 5/74 CGS (temp) 23' 5/74 HMS 50' May (1955-1970) HMS (hist) 50' 2.15 0.94 1.88 3.1 1.75 2.69 1.34 3.7 1.21 0.94 0.81 2.3 1.88 2.82 1.75 2.4 2.02 2.28 3.36 2.2 2.42 4.57 1.88 3.3 8.06 8.20 1.75 2.7 12.37 11.83 2.15 2.8 14.25 9.14 4.70 3.3 6.99 6.32 8.47 6.4 9.27 7.53 14.92 9.8 10.62 8.20 14.25 11.4 12.90 8.06 21.24 18.1 6.32 5.24 13.31 17.2 3.09 2.55 1.75 3.6 1.61 1.48 1.88 3.9 2.02 6.05 3.90 3.2 0.00 0.13 0.67 0.6 6/74 CGS 33' 6/74 CGS (temp) 23' 6/74 HMS 50' June (1955-1970) HMS (hist) 50' 2.50 3.06 1.94 3.6 2.92 4.72 2.92 3.7 4.31 3.75 2.22 2.0 3.33 4.44 2.50 2.2 3.61 7.22 3.75 2.2 5.14 7.50 4.03 2.8 7.22 7.78 2.64 2.1 7.64 6.67 2.36 2.6 7.08 6.53 3.06 3.0 4.03 5.42 4.44 6.5 3.89 3.61 7.22 8.5 7.22 4.86 6.25 11.2 9.31 10.0 24.03 19.6 7.36 10.0 19.58 18.9 3.61 4.72 4.72 3.5 2.50 2.22 2.36 3.9 0.69 7.50 5.56 3.3 0.00 0.00 0.42 0.4 7/74 CGS 33' 7/74 CGS (temp) 23' 7/74 HMS 50' July (1955-1970) HMS (hist) 50' 2.42 3.63 2.82 3.8 3.23 4.30 1.88 3.8 2.42 3.49 2.96 2.0 4.03 3.09 2.55 2.5 3.36 5.51 3.90 2.3 5.38 5.78 3.76 2.9 7.66 8.60 2.69 1.9 9.41 9.14 3.76 2.5 7.26 10.22 2.96 2.5 6.72 3.36 5.11 6.3 4.70 3.76 12.50 8.4 6.59 4.30 12.90 9.9 8.47 5.65 16.53 19.5 9.01 12.50 11.96 18.9 5.51 5.78 2.96 3.5 4.70 3.76 2.42 4.5 4.30 6.99 8.33 4.4 0.00 0.13 0.00 0.4 8/74 CGS 33' 8/74 CGS (temp) 23' 8/74 HMS 50' August (1955-1970) HMS (hist) 50' 6.45 6.72 5.65 3.4 5.65 8.87 3.49 2.9 2.02 4.03 2.55 2.0 2.42 4.03 2.42 2.4 2.82 3.76 2.69 2.7 4.30 5.38 2.55 3.4 8.47 10.48 2.55 2.4 10.08 10.62 2.96 2.5 8.87 5.51 3.49 3.2 4.44 3.49 3.36 6.4 3.76 2.42 7.12 8.6 3.49 2.69 10.62 11.3 9.81 7.39 16.80 18.3 9.01 8.74 16.13 17.4 6.59 7.12 5.65 3.9 7.66 3.49 4.97 4.4 2.42 4.30 6.18 4.2 0.00 0.40 0.81 0.6 9/74 CGS 33' 9/73 CGS (temp) 23' 9/73 HMS 50' September (1955-1970) HMS (hist) 50' 9.58 4.72 7.36 4.9 5.42 6.11 4.86 4.6 5.56 3.61 1.67 2.4 3.33 4.86 3.75 2.9 3.75 3.75 2.50 2.8 2.92 5.42 2.50 3.9 2.92 7.92 2.64 2.7 8.19 8.47 2.92 2.8 5.28 5.28 3.61 3.4 4.03 4.72 4.58 6.0 2.36 2.36 8.61 8.8 5.00 3.75 6.81 11.0 7.78 7.36 15.28 14.7 9.03 6.94 15.97 14.8 8.19 7.08 7.22 4.9 12.92 8.47 4.03 5.6 2.64 9.17 3.06 2.6 0.00 0.00 2.64 1.2 10/74 CGS 33' 10/73 CGS (temp) 23' 10/73 HMS 50' October (1955-1970) HMS (hist) 50' 5.65 3.76 2.42 3.5 5.78 4.70 3.76 3.6 6.59 2.69 2.15 2.3 3.23 4.30 1.75 2.8 2.28 3.63 3.23 3.3 4.84 6.85 3.63 5.1 6.05 9.68 2.96 3.4 6.85 11.96 3.23 3.5 5.65 7.53 5.65 4.5 3.49 5.51 10.89 7.4 3.76 1.75 11.16 9.2 4.97 4.84 9.27 10.7 8.60 7.12 14.78 13.2 7.12 6.85 11.42 12.9 8.06 4.97 4.84 5.4 8.60 3.23 2.82 4.7 2.69 8.20 1.48 1.8 0.13 0.27 4.57 2.7

• For some months, when concurrent measurements are not available for all sites shown; previous year data is given.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-71Table 2.3-10 Percent Frequency of Occurrence of Wind Direction at the Hanford Reservation* (Continued) WIND DIRECTION MONTH/YEAR/SITE/ELEVATION NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW N VARI-ABLE CALM 11/74 CGS 33' 11/73 CGS (temp) 23' 11/73 HMS 50' November (1955-1970) HMS (hist) 50' 5.28 2.22 3.33 3.4 3.61 4.86 1.67 2.6 4.31 1.81 1.81 2.3 1.11 1.53 1.81 2.5 2.08 4.44 3.61 3.1 4.72 8.19 6.11 4.4 7.36 9.72 3.06 3.3 10.42 8.19 5.00 4.2 10.69 5.42 6.25 5.2 6.94 2.22 7.50 7.4 3.33 2.22 4.86 7.1 4.86 5.69 5.42 8.4 7.08 16.25 13.89 13.4 10.42 8.06 19.31 15.1 8.33 3.75 5.97 7.0 6.94 2.92 4.44 4.6 1.81 3.61 0.56 1.4 0.00 0.28 5.42 4.6 12/74 CGS 33' 12/73 CGS (temp) 23' 12/73 HMS 50' December (1955-1970) HMS (hist) 50' 2.28 2.28 2.02 2.5 2.15 5.38 1.48 2.3 1.21 2.28 2.15 1.9 0.94 2.82 2.28 2.3 1.34 3.76 2.28 2.8 2.82 7.53 3.49 4.2 8.06 9.95 3.49 3.4 13.44 10.62 4.30 3.5 11.02 5.24 4.70 4.4 4.84 3.09 7.12 7.1 6.05 2.02 8.20 6.8 6.99 4.30 9.54 6.9 10.89 9.41 13.84 14.8 12.23 10.48 20.02 18.2 8.33 4.84 4.57 6.3 4.57 2.82 1.75 4.2 1.61 7.93 2.15 1.6 0.00 0.67 6.59 6.8 1/75 CGS 33' 1/74 CGS (temp) 23' 1/74 HMS 50' January (1955-1970) HMS (hist) 50' 4.57 2.28 2.69 3.4 3.76 1.88 3.09 2.9 4.44 1.08 2.02 1.9 2.42 1.88 1.34 2.4 3.09 3.09 2.55 2.8 3.63 4.97 4.57 4.7 6.45 7.12 4.03 3.1 6.18 13.17 4.03 3.6 6.99 17.34 5.24 4.9 6.45 8.20 16.67 6.7 6.05 3.23 13.04 6.0 3.76 3.23 7.66 6.1 6.85 5.51 7.53 14.2 11.96 6.32 9.81 19.5 13.71 3.49 4.30 6.4 5.91 1.88 3.09 4.6 1.48 4.70 1.21 1.4 0.00 1.61 4.70 5.4 2/75 CGS 33' 2/74 CGS (temp) 23' 2/74 HMS 50' February (1955-1970) HMS (hist) 50' 4.76 1.04 2.08 4.4 2.38 1.79 2.68 3.5 1.93 1.34 2.08 1.9 0.89 1.64 1.19 2.1 1.64 4.32 4.17 2.2 2.98 7.44 4.46 3.4 7.74 9.08 2.83 2.7 7.89 13.54 5.36 2.9 8.18 13.39 8.63 4.2 4.91 6.25 10.57 7.5 4.61 7.14 12.95 7.4 3.57 5.21 10.86 9.3 5.21 8.33 10.12 15.4 18.76 5.65 10.71 18.4 14.43 2.38 4.91 5.8 8.18 1.34 2.38 5.0 1.19 8.93 2.23 1.5 0.00 0.19 1.79 2.4 3/75 CGS 33' 3/74 CGS (temp) 23' 3/74 HMS 50' March (1955-1970) HMS (hist) 50' 2.82 1.61 1.75 4.5 1.34 2.55 2.69 3.5 1.21 2.02 2.02 1.7 1.34 2.82 1.61 2.0 2.02 1.61 1.21 2.3 2.42 6.59 4.84 3.7 7.26 6.72 3.76 2.8 10.62 10.08 4.30 3.8 8.33 10.08 7.12 5.4 9.81 7.66 15.05 9.9 4.97 4.84 10.75 10.4 2.15 5.65 9.01 9.6 6.99 6.72 11.16 14.4 11.16 6.72 13.04 13.7 11.56 4.57 5.65 5.0 5.91 3.23 2.82 5.1 1.61 9.41 2.82 1.5 0.00 1.08 0.40 0.7 April 1974-March 1975 CGS 33' 1955-1970 HMS (hist) 50' 4.25 3.7 3.42 3.4 2.97 2.0 2.16 2.4 2.47 2.6 3.73 3.7 7.07 2.8 9.35 3.2 8.89 4.1 5.88 7.2 4.89 8.5 5.67 9.8 9.27 16.0 10.08 16.6 7.93 4.9 6.04 4.5 1.96 2.4 0.01 2.2

• For some months, when concurrent measurements are not available for all sites shown; previous year data is given.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-72 Table 2.3-11 Persistence of Wind Direction in One Sector (22.5 Degrees) from 4/74 through 3/75 at 33-ft Level (Stability Based On Temperature Difference) DATE STARTED DAY HOUR WIND DIR HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 400 22 NW 14 0 0 3 11 0 V UNS UNSTA NEUTR M STA V STA .00

.00 10.30 11.08 .00 171 10 S

10 0 1 7

2 0 UNKNO

V UNS UNSTA NEUTR M STA .00 16.00 18.14 15.00 .00

295 15

NNW

10 0 0 0 1

2 V STA UNKNO

V UNS UNSTA NEUTR .00

.00 .00 19.57 21.18

327 14

NW

10 7 0

0 0 0 M STA V STA UNKNO

V UNS UNSTA 9.98 .00

.00 .00

.00

425 6

NNW

10 5 5

0 0 0 NEUTR M STA V STA UNKNO

V UNS 3.81 4.06 .00

.00 .00 1 7 2

0 0 UNSTA NEUTR M STA V STA UNKNO 5.53 5.84 6.81 .00

.00 134 7 SSW 9 0 1 8

0 0 0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 23.78 19.54 .00 .00 .00 219 17 WNW 9 0 2

2 5

0 V UNS UNSTA NEUTR M STA V STA .00 17.34 22.97 16.69 .00 393 2 NW 9 0 0

9 0

V UNS UNSTA NEUTR M STA .00

.00 #999.0 (missing data) .00

404 2

NNW

9 0 0 0 0

1 V STA UNKNO

V UNS UNSTA NEUTR .00

.00 .00

.00 13.63 8 0 0 M STA V STA UNKNO 11.18 .00

.00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-73 Table 2.3-11 Persistence of Wind Direction in One Sector (22.5 Degrees) from 4/74 through 3/75 at 33-ft Level (Continued) (Stability Based on Temperature Difference) DATE STARTED DAY HOUR WIND DIR HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 407 5 SSW 9 0 0 V UNS UNSTA .00

.00

102 13

WNW

8 2 7

0 0 0 NEUTR M STA V STA UNKNO

V UNS 17.20 20.64 .00

.00 .00 5 1 2

0 0 UNSTA NEUTR M STA V STA UNKNO 16.67 19.07 16.91 .00

.00 132 13 WNW 8 0 6 1

1 0

0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 22.17 22.06 17.06 .00

.00 244 11 NNE 8 0 7

1 0

0 V UNS UNSTA NEUTR M STA V STA .00 15.35 12.87 .00

.00 271 16 NW 8 0 0 1

2 5 UNKNO

V UNS UNSTA NEUTR M STA .00 .00 18.52 16.92 11.63

363 10

S

8 0 0 0 0

5 V STA UNKNO

V UNS UNSTA NEUTR .00

.00 .00

.00 13.70

396 21

NW

8 3 0

0 0 0 M STA V STA UNKNO

V UNS UNSTA 13.80 .00

.00 .00

.00

401 12

NNW

8 4 4

0 0

0 0 NEUTR M STA V STA UNKNO V UNS UNSTA 9.10 8.16 .00

.00

.00

.00

402 6

N

8 5 3 0 0 0 NEUTR M STA V STA UNKNO

V UNS 12.80 11.49 .00

.00 .00 0 7 1

0 0 UNSTA NEUTR M STA V STA UNKNO .00 9.04 9.99 .00

.00 426 14 SW 8 0 2 3

3 0

0 V UNS UNSTA NEUTR V STA V STA UNKNO .00 18.58 16.88 15.28 .00

.00 430 8 NNW 8 0 6

1 1

0 V UNS UNSTA NEUTR M STA V STA .00 10.54 10.68 7.82 .00 0 UNKNO .00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-74 Table 2.3-12 Persistence of Wind Direction in Two Sectors (45 Degrees) from 4.74 through 3/75 at CGS for 33-ft Level (Stability Based on Temperature Difference) DATE STARTED DAY HOUR WIND DIRECTIONS HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 400 22 NW NNW 26 0 0 8 15 3 V UNS UNSTA NEUTR M STA V STA .00 .00 11.80 11.05 6.23 379 12 NW NNW 23 0 0 0 6 17 UNKNO V UNS UNSTA NEUTR M STA .00 .00

.00 3.73 3.78 399 23 NW NNW 22 0 0 0 0 7 V STA UNKNO V UNS UNSTA NEUTR .00

.00 .00 .00 15.79 424 21 NW NNW 20 15 0 0 0 2 M STA V STA UNKNO V UNS UNSTA 12.65 .00 .00 .00 4.20 102 1 NNW NW 19 8 10 0 0 0 NEUTR M STA V STA UNKNO V UNS 5.88 7.18 .00

.00 .00 8 2 9 0 0 UNSTA NEUTR M STA V STA UNKNO 18.20 28.03 21.20 .00 .00 400 17 WNW NW 19 0 0 3 16 0 0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 .00 10.30 11.44 .00 .00 244 5 N NNE 18 0 7 7 4 0 V UNS UNSTA NEUTR M STA V STA .00 15.35 15.01 9.66 .00 404 2 NNW N 18 0 0 0 9 9 UNKNO V UNS UNSTA NEUTR M STA .00 .00

.00 11.56 10.83 431 10 NW NNW 18 0 0 0 5 5 V STA UNKNO V UNS UNSTA NEUTR .00

.00 .00 17.79 17.77 171 3 S SSW 17 8 0 0 1 8 M STA V STA UNKNO V UNS UNSTA 8.45 .00 .00 16.00 18.37 224 17 NNW NW 17 5 3 0 0 0 NEUTR M STA V STA UNKNO V UNS 16.60 13.33 .00

.00 .00 4 3 10 0 0 UNSTA NEUTR M STA V STA UNKNO 10.07 14.39 12.00 .00

.00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-75 Table 2.3-12 Persistence of Wind Direction in Two Sectors (45 Degrees) from 4.74 through 3/75 at CGS for 33-ft Level (Continued) (Stability Based on Temperature Difference) DATE STARTED DAY HOUR WIND DIRECTIONS HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 401 21 NNW N 17 0 0 7 3

7 0 V UNS UNSTA NEUTR M STA V STA UNKNO .00

.00 9.04 8.95 6.78 .00 406 21 SSW SW 17 0 0

2 15 0 V UNS UNSTA NEUTR M STA V STA .00

.00 17.20 21.52 .00 438 1 SSE S 17 0 0 2

2 7 UNKNO

V UNS UNSTA NEUTR M STA .00 .00 7.67 5.47 7.21

396 17

WNW NW

16 6 0 0 0 10 V STA UNKNO

V UNS UNSTA NEUTR 8.80 .00 .00

.00 8.80

423 8

NW NNW

16 6 0

0 0 0 M STA V STA UNKNO

V UNS UNSTA 7.94 .00

.00 .00

.00

98 11

WNW NW

15 10 6 0

0 0 3 NEUTR M STA V STA UNKNO

V UNS UNSTA 7.61 5.58 .00

.00 .00 15.67

253 15

WNW NW

15 4 8

0 0 0 NEUTR M STA V STA UNKNO

V UNS 14.00 11.62 .00

.00 .00 0 2 9

4 0 UNSTA NEUTR M STA V STA UNKNO .00 16.41 11.59 7.27 .00 293 11 W WNW 15 0 4 3

8 0

0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 16.25 18.27 9.39 .00

.00 355 6 WSW W 15 0 0

7 8

0 V UNS UNSTA NEUTR M STA V STA .00

.00 25.65 15.14 .00 0 UNKNO .00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-76Table 2.3-12a Longest Persistence of Wind Direction in One (22.5 Degrees) and Two (45 Degrees) Sectors During First and Second Annual Cycles at 33-ft Level (Stability Based on Temperature Difference) First Annual Cycle (April '74 - March '75) Second Annual Cycle (April '75 - March '76)

MONTH WIND DIRECTION HOURS OF PERSISTENCE HOURS OF EACH STABILITY AVERAGE WIND SPEED MONTH WIND DIRECTION HOURS OF PERSISTENCE HOURS OF EACH STABILITY AVERAGE WIND SPEED January NW 14 0 0

3 11 0 0

V UNS UNSTA NEUTR M STA V STA UNKNO

.00

.00 10.30 11.08 .00 .00 February NNE 33 0 3 10 20 0 0 V UNS UNSTA NEUTR M STA V STA UNKNO

.00 30.22 29.04 23.15 .00 .00 January NW, NNW 26 0 0

8 15 3 0

V UNS UNSTA NEUTR M STA V STA UNKNO

.00

.00 11.86 11.05 6.23 .00 January N, NNE 35 0 3 10 22 0 0

V UNS UNSTA NEUTR M STA V STA UNKNO

.00 30.22 29.04 21.84 .00

.00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-77Table 2.3-13 Percent Frequency of Occurrence of Wind Speed at the Hanford Reservation (1) Wind Speed Range, mph (2) Month/Year/Site/Elevations Calm 1-3 4-7 8-12 13-18 19-24 25-Up Average Speed (mph) 4/74 CGS 33' 4/74 CGS (temp) 23' 4/74 HMS 50' April (1955-1970) HMS (hist) 50' 0.00 0.00 0.42 9.58 13.19 9.72 16.8 31.11 37.50 26.11 31.6 24.17 23.47 33.33 26.6 18.19 17.78 19.72 16.2 6.25 4.72 7.64 6.6 1.81 0.42 3.06 2.2 9.8 8.7 10.3 9.0 5/74 CGS 33' 5/74 CGS (temp) 23' 5/74 HMS 50' May (1955-1970) HMS (hist) 50' 0.00 0.13 0.67 12.50 14.11 12.63 16.6 36.16 38.17 30.11 33.3 33.33 28.23 32.66 27.9 12.77 11.96 18.15 15.1 3.63 2.55 5.38 6.0 0.54 0.67 0.40 1.1 8.4 7.9 9.0 8.8 6/74 CGS 33' 6/74 CGS (temp) 23' 6/74 HMS 50' June (1955-1970) HMS (hist) 50' 0.00 0.00 0.42 11.25 21.67 13.61 11.7 44.03 47.64 35.42 34.6 23.89 18.06 26.11 28.1 9.72 9.03 15.69 17.4 3.61 3.06 7.64 6.8 1.11 0.56 1.11 1.4 8.5 6.9 9.0 9.2 7/74 CGS 33' 7/74 CGS (temp) 23' 7/74 HMS 50' July (1955-1970) HMS (hist) 50' 0.00 0.13 0.00 16.13 25.40 16.26 15.0 43.95 45.30 38.44 37.8 24.33 19.89 27.28 26.2 8.74 8.06 13.44 14.2 1.61 1.21 4.57 5.8 0.40 0.00 0.00 1.0 7.2 6.4 8.1 8.6 8/74 CGS 33' 8/74 CGS (temp) 23' 8/74 HMS 50' August (1955-1970) HMS (hist) 50' 0.00 0.40 0.81 21.91 27.82 16.53 18.9 46.37 46.24 43.28 38.2 19.35 17.20 26.21 25.6 7.12 6.85 7.53 12.3 3.36 1.21 5.11 4.2 0.13 0.00 0.54 0.8 6.8 6.0 7.5 8.0 9/74 CGS 33' 9/73 CGS (temp) 23' 9/73 HMS 50' September (1955-1970) HMS (hist) 50' 0.00 0.00 2.64 27.78 26.67 20.42 23.6 38.06 42.08 36.25 36.8 22.50 22.50 28.33 23.8 8.75 7.50 8.75 10.9 1.39 1.25 3.19 4.1 0.42 0.00 0.42 0.8 6.5 6.2 7.1 7.5 (1) For some months, when, concurrent measurements are not available for all sites shown; previous year data is given. (2) HMS (hist) 50' calm values are included in the 1-3 mph range group.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-78Table 2.3-13 Percent Frequency of Occurrence of Wind Speed at the Hanford Reservation (1) (Continued) Month/Year/Site/Elevation Calm 1-3 4-7 8-12 13-18 19-24 25-Up Average Speed (mph) 10/74 CGS 33' 10/73 CGS (temp) 23' 10/73 HMS 50' October (1955-1970) RMS (hist) 50' 0.13 0.27 4.57 44.49 30.91 25.81 32.1 34.27 40.99 34.95 34.0 11.16 16.80 23.39 21.3 3.36 8.87 7.53 8.3 0.94 2.15 3.23 3.3 0.00 0.00 0.54 1.0 4.8 6.2 6.7 6.7 11/74 CGS 33' 11/73 CGS (temp) 23' 11/73 HMS 50' November (1955-1970) HMS (hist) 50' 0.00 0.28 5.42 34.72 17.92 19.86 39.7 39.58 37.08 33.89 30.1 16.11 21.53 26.67 18.9 5.97 7.78 6.81 7.5 1.53 2.36 5.28 2.7 0.00 0.00 2.08 1.1 5.8 7.1 7.5 6.2 12/74 CGS 33' 12/73 CGS (temp) 23' 12/73 HMS 50' December (1955-1970) HMS (hist) 50' 0.00 0.67 6.59 31.05 41.53 25.13 41.4 37.23 31.72 31.05 29.2 21.51 15.86 23.79 18.9 6.05 8.74 9.95 6.7 1.61 1.21 3.09 2.5 1.21 0.27 0.40 1.3 6.4 5.7 6.7 6.0 1/75 CGS 33' 1/74 CGS (temp) 23' 1/74 HMS 50' January (1955-1970) HMS (hist) 50' 0.00 2.02 4.70 29.44 29.97 21.10 38.8 36.83 24.46 26.48 30.2 19.76 15.46 21.24 19.5 5.38 16.40 13.31 7.6 2.02 7.80 7.66 2.7 0.67 3.90 5.51 1.2 6.4 8.7 9.3 6.4 2/75 CGS 33' 2/74 CGS (temp) 23' 2/74 HMS 50' February (1955-1970) HMS (hist) 50' 0.00 1.19 1.79 22.47 26.64 20.09 30.8 36.90 29.17 33.63 31.0 23.36 22.17 23.66 23.9 9.82 15.03 15.63 9.3 5.21 4.46 4.61 3.2 1.49 1.34 0.60 1.7 7.8 7.6 8.0 7.0 3/75 CGS 33' 3/74 CGS (temp) 23' 3/74 HMS 50' March (1955-1970) HMS (hist) 50' 0.00 1.08 0.40 13.04 28.90 16.94 20.0 31.85 31.32 33.33 32.6 27.02 18.68 25.81 26.1 14.11 12.77 13.04 13.5 4.44 3.36 7.66 5.4 1.08 3.36 2.82 2.4 8.7 7.8 9.1 8.4 April 1974 - March 1975 CGS 33' 1955-1970 HMS (hist) 50' 0.01 22.89 25.4 38.04 33.3 22.20 23.9 9.14 11.6 2.95 4.4 0.73 1.4 7.2 7.6 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-79Table 2.3-14 Diurnal Variation of 33-ft Elevation Dry Bulb Temperature (F) at CGS and Monthly Average Dry Bulb Temperature (F) at the Hanford Reservation Month/Year Hour April 1974 May 1974 June 1974 July 1974 August 1974 September 1974 October 1974 November1974 December 1974 January 1975 February1975 March 1975 Annual Average(April 1974 -March 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 46.7 46.1 44.9 44.4 43.3 43.6 45.3 49.2 51.8 54.2 56.2 57.9 59.3 60.5 60.9 60.9 60.3 58.8 56.1 53.6 51.8 50.3 48.9 47.7 51.0 49.8 48.3 46.9 45.8 47.0 50.9 54.4 56.8 59.0 61.3 63.1 64.9 66.3 67.5 67.7 67.4 66.2 63.9 60.3 57.7 56.0 54.2 52.7 63.7 62.1 60.3 58.1 57.5 59.6 63.8 68.0 72.7 75.3 78.0 80.5 82.3 83.8 85.1 84.6 85.1 84.1 81.9 77.8 73.7 70.7 68.0 66.0 66.5 64.5 62.2 60.8 59.7 61.0 65.3 69.3 73.0 75.1 77.3 79.4 81.3 83.2 84.7 85.2 85.2 84.7 82.7 78.7 75.5 73.0 70.8 68.9 66.8 64.6 63.0 61.2 60.0 59.6 63.6 68.8 72.9 76.4 79.1 81.6 84.0 86.2 87.5 88.4 88.4 87.1 83.7 79.6 75.7 73.6 71.0 69.0 58.2 57.1 56.3 55.3 54.1 53.0 53.9 58.9 64.8 68.6 72.0 75.2 77.8 79.8 81.0 81.6 81.2 78.4 73.6 69.4 67.1 64.5 62.3 60.4 45.6 44.7 43.3 42.6 41.3 40.8 40.4 43.4 48.3 52.7 56.4 59.5 62.0 63.7 64.8 65.1 63.7 60.0 56.4 53.5 51.3 49.4 48.2 46.4 40.3 40.1 39.6 39.5 39.0 38.7 38.3 38.3 39.9 41.6 43.8 45.4 46.7 47.4 47.6 46.9 45.0 43.5 42.7 42.1 41.6 41.0 40.2 40.0 35.3 35.3 35.1 35.0 34.9 34.1 33.8 33.8 34.4 35.8 37.9 39.6 41.0 41.7 41.5 40.5 38.8 37.7 36.8 36.8 36.8 36.1 35.2 35.1 30.9 30.8 30.4 30.6 30.1 30.0 29.4 29.5 30.3 31.7 33.0 34.9 35.7 36.5 37.2 36.7 35.2 33.9 32.9 32.1 31.5 31.1 31.0 30.8 30.6 30.5 30.1 30.2 30.1 29.8 29.6 29.3 31.3 33.9 35.6 37.6 38.6 39.3 39.7 39.5 38.7 36.8 35.3 34.4 33.8 32.8 32.4 31.6 37.5 36.6 35.9 35.0 34.9 34.7 35.1 37.4 40.6 42.9 45.2 46.9 48.6 49.4 50.3 50.8 50.0 47.9 44.9 42.7 41.2 40.1 39.2 38.1 47.9 46.9 45.9 45.1 44.3 44.4 45.8 48.4 51.2 54.3 56.2 58.4 60.1 61.6 62.4 62.3 61.7 60.4 57.7 55.2 53.3 51.7 50.2 49.0 Monthly Average Dry Bulb Temperature (F)* (Site, Elevation)

CGS 33' CGS 7' CGS (temp) 3' HMS 3' 1950-1970 HMS (hist) 3' 52.2 52.7 53.3 52.5 52.5 57.4 58.3 59.6 57.9 61.8 72.5 73.0 74.2 73.3 69.9 73.6 74.3 75.3 74.8 77.5 74.7 75.0 76.3 76.3 75.3 66.9 66.3 (65.0) 68.3 67.0 51.7 50.6 (51.2) 52.0 53.2 42.1 41.9 (39.7) 42.1 40.1 36.8 36.1 (37.8) 35.7 33.4 32.3 32.2 (29.0) 32.0 30.3 33.8 33.9 (40.7) 33.6 37.5 41.9 42.2 (45.4) 42.0 44.0 53.1 53.1 Not Computed 53.4 *For some months, when concurrent measurements are not available for all sites shown, former year data is given in parentheses.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-80Table 2.3-15 Diurnal Variation of 33-ft Elevation Wet Bulb Temperature (F) at CGS and Monthly Average Wet Bulb Temperature (F) at the Hanford Reservation Month/Year Hour April 1974 May 1974 June 1974 July 1974 August 1974 September1974 October 1974 November1974 December 1974 January 1975 February 1975 March 1975 Annual Average(April 1974 -March 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 41.9 41.5 40.9 40.7 40.2 40.5 41.9 44.2 45.5 46.6 47.1 47.8 48.2 48.6 48.7 48.6 48.5 48.0 46.8 45.8 44.8 43.8 43.1 42.5 44.4 43.8 43.3 42.6 41.9 42.7 44.9 46.1 47.5 48.1 49.1 49.7 50.3 50.7 51.0 50.9 50.8 50.4 49.7 48.5 47.4 46.6 45.8 45.1 52.1 51.6 50.9 50.1 50.0 51.2 53.3 54.9 56.8 57.7 58.8 59.6 60.0 60.3 60.7 60.1 60.5 60.3 59.6 58.4 56.5 54.9 54.1 53.1 54.7 54.1 53.1 52.6 52.3 53.4 55.4 56.9 57.9 58.5 59.0 59.7 60.2 60.4 60.9 61.1 61.0 60.8 60.1 59.0 58.0 57.2 56.2 55.6 54.9 54.1 53.5 52.8 52.5 52.3 54.5 56.8 58.2 59.7 60.6 61.2 61.7 62.2 62.4 62.6 62.6 62.0 60.9 59.6 58.0 57.3 56.6 55.8 49.1 48.6 48.0 47.6 47.0 46.4 47.1 49.7 52.6 54.2 55..4 56.5 57.4 57.9 58.2 58.3 58.0 57.0 55.4 53.6 52.4 51.4 50.5 49.7 40.7 40.1 39.3 38.9 38.0 37.8 37.5 39.5 42.7 44.9 46.7 48.0 49.1 49.7 50.2 50.3 49.8 48.4 46.4 44.8 43.4 42.4 41.8 41.1 38.0 38.0 37.6 37.6 37.3 37.1 36.8 36.9 38.2 39.3 40.8 41.6 42.3 42.6 42.8 42.4 41.4 40.5 40.0 39.6 39.0 38.5 37.8 37.7 33.5 33.6 33.5 33.4 33.2 32.7 32.4 32.2 32.6 34.0 35.4 36.4 37.3 37.6 37.6 36.9 35.8 35.1 34.4 34.4 34.4 34.1 33.5 33.5 29.0 29.0 28.7 28.9 28.5 28.4 27.9 27.8 28.4 29.6 30.6 31.8 32.3 32.8 33.2 32.9 31.9 30.9 30.4 29.7 29.4 29.0 29.0 28.8 28.9 28.7 28.5 28.4 28.3 28.0 27.8 27.6 29.5 31.2 32.1 33.2 33.9 34.2 34.5 34.4 34.0 32.9 32.0 31.4 31.1 30.5 30.3 29.6 34.0 33.4 32.9 32.3 32.2 32.1 32.4 34.3 36.1 37.1 38.3 39.0 39.5 40.0 40.4 40.6 40.1 39.2 37.8 36.8 35.9 35.2 34.6 34.0 41.8 41.4 40.9 40.6 40.2 40.3 41.0 42.3 43.8 45.3 46.1 47.0 47.7 48.2 48.4 48.3 48.0 47.2 46.2 45.2 44.3 43.5 42.8 42.3 Monthly Average Wet Bulb Temperature (F)* (Site, Elevation) CGS 33' CGS (temp) 3' HMS 3' 1950-1970 HMS (hist) 3' 44.7 45.9 43.9 42.8 47.2 49.8 46.5 49.1 56.0 60.0 54.5 54.5 57.4 61.0 56.3 57.9 58.0 62.6 57.0 57.3 52.6 (54.6) 52.0 52.6 43.8 (45.5) 42.0 45.4 39.3 (37.8) 38.0 36.4 34.5 (36.4) 33.0 31.2 30.0 (26.4) 30.0 27.9 30.9 (36.6) 31.0 33.6 36.2 (39.3) 36.0 37.3 44.3 Not Calculated 43.4 *For some months, when concurrent measurements are not available for all sites shown, former year data is given in parentheses.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-81Table 2.3-16 Diurnal Variation of 33 ft Elevation Dew Point Temperature (F) at CGS and Monthly Average Dew Point Temperature (F) at the Hanford Reservation Month/Year Hour April 1974 May 1974 June 1974 July 1974 August 1974 September1974 October 1974 November1974 December 1974 January 1975 February1975 March 1975 Annual Average(April 1974 -March 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 36.5 36.5 36.6 36.8 36.7 37.0 38.3 38.8 38.8 38.8 37.8 37.3 36.8 36.4 35.9 35.8 36.0 36.6 37.0 37.3 37.1 36.8 36.7 36.6 37.3 37.5 37.8 37.9 37.7 38.1 38.6 37.3 37.8 37.2 36.7 36.2 35.5 35.1 34.6 34.0 34.1 34.5 35.2 36.3 36.6 36.8 37.1 37.1 42.0 42.5 42.7 43.1 43.3 44.1 44.6 44.3 44.4 44.2 44.2 43.8 43.3 42.6 42.3 41.5 41.9 42.4 42.8 43.5 42.7 41.7 42.4 42.1 45.1 45.4 45.5 45.7 46.2 47.2 47.5 47.5 46.7 46.0 45.7 45.3 44.4 43.3 43.1 43.1 42.7 42.9 42.6 43.5 44.4 44.7 44.5 44.9 45.4 45.6 45.8 45.9 46.3 46.4 47.3 47.8 47.3 47.7 47.4 46.7 46.0 45.3 44.5 44.0 44.0 43.7 44.1 44.5 44.4 44.6 45.2 45.3 40.5 40.6 39.9 40.1 40.1 39.8 40.4 41.0 41.8 41.7 41.4 40.9 40.4 39.7 39.4 39.0 38.5 38.6 39.4 39.2 38.8 38.9 39.2 39.5 35.0 34.6 34.4 34.6 34.0 34.2 34.0 35.0 36.3 36.3 36.2 36.0 35.6 35.3 35.1 35.1 35.5 36.1 35.3 34.8 34.0 33.8 34.2 34.7 35.4 35.5 35.4 35.6 35.4 35.3 35.1 35.2 36.4 36.7 37.4 37.5 37.4 37.3 37.7 37.4 37.4 37.1 37.0 36.7 36.2 35.5 35.1 35.0 31.2 31.4 31.4 31.4 31.0 30.8 30.5 30.0 30.3 31.7 32.2 32.3 32.5 32.1 32.4 32.1 31.8 31.5 31.1 31.0 31.3 31.2 31.1 31.2 26.0 26.1 25.9 26.0 26.0 25.8 25.5 25.1 25.4 26.4 26.9 27.0 27.2 27.5 27.4 27.4 27.0 26.4 25.9 26.0 25.8 25.6 25.6 26.1 26.0 25.9 25.4 25.4 25.2 24.9 24.9 26.8 27.1 26.9 26.8 27.0 27.0 27.0 27.2 27.2 27.1 27.2 27.1 27.2 27.1 27.2 26.6 28.6 28.6 28.3 28.4 28.4 28.2 28.5 30.0 29.6 28.8 28.3 27.6 27.2 26.6 26.3 26.3 25.9 26.7 27.6 28.3 28.3 27.9 27.9 27.9 35.8 35.9 35.9 36.0 35.9 36.1 36.3 36.5 36.8 37.1 36.8 36.5 36.1 35.7 35.5 35.2 35.2 35.4 35.5 35.7 35.6 35.4 35.6 35.6 Monthly Average Dew Point Temperature (F) (Site/Elevation)

CGS 33' HMS 3' 1950-1970 HMS (hist) 3' 36.6 33.3 30.4 36.6 34.0 36.0 43.0 38.2 41.2 44.9 41.0 42.3 45.6 43.2 42.8 39.9 38.9 39.5 35.0 31.0 36.9 36.3 33.9 31.1 31.4 29.2 27.5 26.3 26.0 23.2 26.5 25.5 27.4 27.9 26.0 27.3 35.9 33.4 COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000LDCN-99-000 2.3-82Table 2.3-17 Frequency of Occurrence, Dry Bulb Temperature (F) Versus Time of Day from 4/74 through 3/75 for 33-ft Level TIME OF DAY -20

-15 -20

-15

-10 1 0

0 0 2 0

0 0 3 0

0 0 4 0

0 0 5 0

0 0 6 0

0 0 7 0

0 0 8 0

0 0 9 0

0 0 10 0 0

0 11 0 0

0 12 0 0

0 13 0 0

0 14 0 0

0 15 0 0

0 16 0 0

0 17 0 0

0 18 0 0

0 19 0 0

0 20 0 0

0 21 0 0

0 22 0 0

0 23 0 0

0 24 0 0

0 TOTAL0 0

0 5 0 5 10 15 -5 0 5 10 15 20 0 0

0 0

1 2 0 0

0 0

1 2 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 7 0 0

0 0

0 5 0 0

0 0

0 7 0 0

0 0

0 8 0 0

0 0

0 4 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 2 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 2 0 0

0 0

0 3 0 0

0 0

1 3 0 0

0 0

1 3 0 0

0 0

1 2 0 0

0 0

5 69 20 25 30 35 40 45 25 30 35 40 45 50 11 22 44 42 40 51 11 26 46 39 45 52 13 27 43 45 48 48 13 29 44 46 54 46 14 30 42 48 57 48 13 37 41 44 57 43 17 28 41 46 45 42 14 27 31 39 36 38 10 25 26 24 35 38 7 17 26 27 28 37 5 13 25 31 28 35 4 9 21 30 31 32 4 9 12 32 28 34 3 9 14 21 37 29 3 9 11 23 36 29 3 8 14 26 34 29 4 9 20 28 26 41 6 11 19 32 34 36 7 10 29 37 35 33 9 8 37 35 35 29 9 9 41 34 38 34 9 11 40 45 33 39 9 13 47 40 43 37 10 20 45 38 46 39 208 416 759 852 929 919 50 55 60 65 70 75 55 60 65 70 75 80 33 31 27 25 26 7 30 33 29 26 20 2 34 32 32 25 11 1 40 31 32 21 3 0 31 33 29 20 2 0 38 28 30 23 2 0 28 34 28 25 18 2 28 30 28 28 22 17 34 17 24 30 18 16 35 24 20 31 33 18 33 33 20 25 31 29 32 34 27 19 26 37 32 33 22 27 27 20 33 30 22 32 24 22 36 25 24 26 26 26 39 21 24 24 27 24 25 24 24 24 25 21 23 30 23 17 29 19 26 31 21 25 16 31 41 27 19 27 30 17 40 27 21 29 23 27 34 26 33 23 26 23 32 29 28 24 30 20 35 29 26 35 20 12 792 692 613 611 515 391 80 85 90 95 100 105 85 90 95 100 105 110 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 1 0

0 0

0 0 16 1 0

0 0

0 15 10 1 0

0 0 15 16 5 0

0 0 18 19 9 1

0 0 37 12 20 3 0

0 34 17 20 9 0

0 20 31 16 14 2 0 17 30 21 14 3 0 22 26 20 16 3 0 27 19 18 13 2 0 16 23 13 7 1

0 22 16 8 0

0 0 19 8 0

0 0

0 14 2 0

0 0

0 5 1

0 0

0 0 4 0

0 0

0 0 302 231 151 77 11 0 110 UNKNO TOTAL 0 3 365 0 3 365 0 3 365 0 3 365 0 4 365 0 4 365 0 4 365 0 18 365 0 47 365 0 33 365 0 18 365 0 14 365 0 12 365 0 8 365 0 7 365 0 6 365 0 6 365 0 6 365 0 3 365 0 3 365 0 3 365 0 3 365 0 3 365 0 3 365 0 217 8760 COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORTApril 2000LDCN-99-000 2.3-83Table 2.3-18 Frequency of Occurrence, Wet Bulb Temperature (F) Versus Time of Day from 4/74 through 3/75 for 33-ft Level TIME OF DAY -20

-15 -20

-15

-10 1 0

0 0 2 0

0 0 3 0

0 0 4 0

0 0 5 0

0 0 6 0

0 0 7 0

0 0 8 0

0 0 9 0

0 0 10 0 0

0 11 0 0

0 12 0 0

0 13 0 0

0 14 0 0

0 15 0 0

0 16 0 0

0 17 0 0

0 18 0 0

0 19 0 0

0 20 0 0

0 21 0 0

0 22 0 0

0 23 0 0

0 24 0 0

0 TOTAL 0 0

0 5 0 5 10 15 -5 0 5 10 15 20 0 0

0 0

2 1 0 0

0 0

2 2 0 0

0 0

2 4 0 0

0 0

1 7 0 0

0 0

1 9 0 0

0 0

1 8 0 0

0 0

1 9 0 0

0 0

2 8 0 0

0 0

1 5 0 0

0 0

1 3 0 0

0 0

1 3 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 2 0 0

0 0

0 2 0 0

0 0

0 2 0 0

0 0

1 1 0 0

0 0

1 1 0 0

0 0

1 3 0 0

0 0

1 4 0 0

0 0

2 2 0 0

0 0

2 2 0 0

0 0

2 1 0 0

0 0 25 88 20 25 30 35 40 45 25 30 35 40 45 50 14 35 44 54 73 43 15 33 51 51 73 44 18 35 46 58 65 52 14 42 47 57 65 54 14 41 50 60 61 51 16 43 45 67 56 47 18 41 42 60 53 51 15 34 37 51 55 47 9 30 32 44 52 39 8 24 33 41 51 49 8 14 39 45 52 51 6 10 43 39 50 54 6 7 33 50 45 52 6 7 26 49 53 50 6 7 24 51 51 52 5 10 28 50 51 48 7 11 31 50 48 47 8 14 35 52 44 49 10 18 41 48 48 52 9 18 48 46 50 55 8 23 47 48 62 43 10 26 55 44 56 52 9 35 47 56 57 44 12 39 44 49 65 52 251 597 968 1220 1336 1178 50 55 60 65 70 75 55 60 65 70 75 80 48 39 8 0

0 0 50 33 6 1

0 0 49 27 5 0

0 0 48 23 3 0

0 0 51 18 4 0

0 0 51 23 3 0

0 0 38 39 8 0

0 0 39 41 18 0 0

0 43 36 23 3 0

0 42 38 33 5 0

0 39 49 39 6 0

0 44 50 43 8 0

0 49 50 46 12 0 0 49 52 47 15 0 0 52 47 45 21 0 0 51 46 44 24 0 0 51 44 45 23 0 0 43 51 44 17 0 0 42 46 41 14 0 0 49 39 35 9 0

0 55 45 22 4 0

0 48 46 19 1 0

0 49 48 11 1 0

0 44 44 9 0

0 0 1124 974 601 164 0 0 80 UNKNO TOTAL 0 4 365 0 4 365 0 4 365 0 4 365 0 5 365 0 5 365 0 5 365 0 18 365 0 48 365 0 37 365 0 19 365 0 15 365 0 12 365 0 8 365 0 7 365 0 6 365 0 6 365 0 6 365 0 3 365 0 3 365 0 3 365 0 4 365 0 4 365 0 4 365 0 234 8760 COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000LDCN-99-000 2.3-84Table 2.3-19 Frequency of Occurrence, Dew Point Temperature (F) Versus Time of Day from 4/74 through 3/75 for 33-ft Level TIME OF DAY -40

-35 -40

-35

-30 1 0

0 0 2 0

0 0 3 0

0 0 4 0

0 0 5 0

0 0 6 0

0 0 7 0

0 0 8 0

0 0 9 0

0 0 10 0 0

0 11 0 0

0 12 0 0

0 13 0 0

0 14 0 0

0 15 0 0

0 16 0 0

0 17 0 0

0 18 0 0

0 19 0 0

0 20 0 0

0 21 0 0

0 22 0 0

0 23 0 0

0 24 0 0

0 TOTAL 0 0

0-30

-25

-20

-15 5 -25

-20

-15 5 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 5 10 15 20 25 5 10 15 20 25 30 0 1

4 12 23 45 0 2

2 14 22 47 0 1

5 12 24 44 0 2

4 13 22 46 0 2

4 13 28 43 0 3

2 16 23 44 0 2

3 16 23 46 1 1

2 16 22 48 1 1

3 8 17 48 1 1

4 5 18 48 1 2

3 7 21 44 1 3

3 10 20 44 1 1

4 11 20 48 1 3

2 11 23 47 1 3

3 11 25 48 1 2

4 10 26 49 1 2

3 11 28 49 0 2

4 13 24 45 0 1

5 11 22 47 0 1

4 10 25 47 0 1

2 12 26 45 0 1

2 13 30 43 0 1

2 16 24 49 0 1

3 13 28 48 10 40 77 284 564 1112 30 35 40 45 50 55 35 40 45 50 55 60 74 86 67 38 7 3 70 77 77 38 8 3 74 74 73 42 9 2 67 77 73 44 10 2 65 81 65 48 6 4 68 77 66 46 11 2 60 78 64 42 21 4 48 81 59 44 20 4 47 70 56 47 16 4 45 74 65 48 15 5 53 87 56 54 15 4 56 89 66 47 9 3 59 90 67 42 8 3 69 80 73 40 6 2 66 78 78 38 6 1 66 90 73 30 7 1 66 92 69 29 6 3 74 86 71 24 9 3 76 86 74 27 10 3 73 88 70 30 10 3 76 91 68 28 6 4 76 91 62 33 8 1 70 88 65 35 7 3 73 78 67 40 6 4 1571 1991 1626 934 238 71 60 65 70 75 80 65 70 75 80 UNKNO 1 0

0 0

0 4 1 0

0 0

0 4 1 0

0 0

0 4 1 0

0 0

0 4 1 0

0 0

0 5 2 0

0 0

0 5 1 0

0 0

0 5 1 0

0 0

0 18 0 0

0 0

0 47 0 0

0 0

0 36 0 0

0 0

0 18 0 0

0 0

0 14 0 0

0 0

0 11 0 0

0 0

0 8 0 0

0 0

0 7 0 0

0 0

0 6 0 0

0 0

0 6 0 0

0 0

0 6 0 0

0 0

0 3 1 0

0 0

0 3 1 0

0 0

0 3 1 0

0 0

0 4 1 0

0 0

0 4 0 0

0 0

0 4 13 0 0

0 0 229 TOTAL 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 8760 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-85Table 2.3-20 Monthly Averages of Psychrometric Data Based on Period of Record (1950-1970) AVERAGES JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC YEAR DRY BULB WET BULB REL HUM.

DEWPOINT 30.3 27.9 76.0 23.2 37.5 33.6 69.7 27.4 44.0 37.3 55.0 27.3 52.5 42.8 46.4 30.4 61.8 49.1 41.8 36.0 69.9 54.5 39.4 41.2 77.5 57.9 31.5 42.3 75.3 57.3 34.9 42.8 67.0 52.6 39.9 39.5 53.2 45.4 57.7 36.9 40.1 36.4 72.6 31.1 33.4 31.2 80.8 27.5 53.5 43.8 53.8 33.8 MONTHLY AVERAGE EXTREMES DRY BULB HIGHEST YEAR LOWEST YEAR 43.0 1953 12.9 1950 44.0 1958 25.8 1956 48.7 1968 39.6 1955 56.2 1956 48.3 1955 68.7 1958 57.2 1962 75.5 1969 64.2 1953 82.8 1960 73.2 1963 82.5 1967 70.6 1964 72.0 1967 61.6 1970 59.1 1952 50.3 1968 45.8 1954 32.3 1955 38.8 1953 26.5 1964 56.3 1953 51.0 1955+

WET BULB HIGHEST YEAR LOWEST YEAR 39.3 1953 12.4 1950 40.7 1958 23.4 1956 40.8 1963 32.9 1955 45.1 1962 39.3 1955 54.6 1958 45.4 1959 58.6 1958 51.4 1954 61.2 1958 55.6 1954 61.1 1961 54.9 1964 56.5 1963 48.3 1970 47.7 1962 42.4 1970 42.3 1954 29.6 1955 35.8 1966 25.0 1964 46.5 1958 41.8 1955 REL HUM. HIGHEST YEAR LOWEST YEAR 89 1960 60 1963 87 1963 54 1967 66 1950 44 1965 64 1963 37 1966 *52 1962+

31 1966 54 1950 34 1960 40 1955 22 1959 44 1968 24 1967 55 1969 34 1952 74 1962 42 1952 80 1956 64 1963+ 90 1950 69 1968 58 1950+

49 1967 DEWPOINT HIGHEST YEAR LOWEST YEAR 34.4 1953 6.5 1950 36.7 1958 17.3 1956 34.0 1961 20.8 1965+ 37.1 1963 26.2 1955 43.8 1957 30.4 1964 47.5 1958 37.5 1954 46.6 1958 35.4 1959 46.9 1961 38.4 1955 45.4 1963 33.8 1970 43.5 1962 32.1 1970 38.3 1954 24.0 1959 34.3 1950 21.0 1951 37.7 1958 31.5 1955 +Also in Earlier Years *Although not included in these tables, an average of 63% was recorded in 1948 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-86Table 2.3-21 Diurnal Variation of Precipitation Intensity (Inches/Hour) at CGS and Monthly Total Precipitation (Inches) at the Hanford Reservation HOUR APRIL 1974 MAY 1974 JUNE 1974 JULY 1974 AUGUST 1974 SEPTEMBER 1974 OCTOBER1974 NOVEMBER1974 DECEMBER1974 JANUARY 1975 FEBRUARY1975 MARCH 1975 AVERAGE FOR HOUR (APRIL 1974 - MARCH 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 0.000 0.000 0.016 0.000 0.016 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.024 0.032 0.016 0.016 0.024 0.016 0.020 0.000 0.000 0.032 0.080 0.036 0.136 0.016 0.000 0.000 0.032 0.048 0.072 0.000 0.088 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.048 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.024 0.032 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.168 0.040 0.032 0.016 0.000 0.016 0.032 0.000 0.000 0.000 0.016 0.000 0.000 0.000 0.000 0.016 0.056 0.000 0.024 0.000 0.000 0.000 0.032 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.064 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.016 0.000 0.064 0.000 0.000 0.000 0.016 0.000 0.016 0.000 0.000 0.000 0.000 0.016 0.024 0.056 0.024 0.000 0.000 0.000 0.000 0.032 0.036 0.040 0.028 0.052 0.028 0.000 0.000 0.000 0.000 0.016 0.040 0.032 0.020 0.020 0.016 0.016 0.000 0.000 0.000 0.000 0.024 0.056 0.020 0.036 0.024 0.032 0.000 0.040 0.000 0.032 0.000 0.024 0.048 0.000 0.000 0.020 0.016 0.064 0.072 0.020 0.024 0.024 0.000 0.056 0.024 0.036 0.024 0.032 0.048 0.040 0.032 0.032 0.020 0.024 0.016 0.048 0.024 0.032 0.032 0.000 0.000 0.000 0.000 0.016 0.024 0.016 0.072 0.040 0.016 0.016 0.000 0.000 0.024 0.064 0.036 0.000 0.024 0.016 0.000 0.020 0.032 0.040 0.000 0.000 0.000 0.000 0.000 0.016 0.048 0.032 0.024 0.028 0.024 0.024 0.000 0.000 0.000 0.000 0.000 0.000 0.048 0.088 0.000 0.016 0.080 0.071 0.029 0.026 0.018 0.030 0.045 0.026 0.029 0.039 0.036 0.034 0.022 0.032 0.024 0.033 0.029 0.038 0.026 0.034 0.032 0.040 0.021 0.040 0.038 MONTHLY TOTAL PRECIPITATION (INCHES)

CGS HMS HMS (hist) 1946-1970 Mean Total 0.55 0.46 0.44 0.44 0.28 0.50 0.06 0.12 0.66 0.45 0.71 0.16 0.00 trace 0.21 0.06 0.01 0.30 0.10 0.21 0.61 0.56 0.71 0.80 0.67 0.97 0.81 0.93 1.43 0.97 0.67 0.98 0.58 0.52 0.33 0.38 4.92 6.21 6.53 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-87Table 2.3-22 Frequency of Occurrence, Precipitation (Inches/Hour) Versus Time of Day from 4/74 through 3/75 at CGS

Time of Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24TOTAL 016 6 5 7 4 5 5 8 5 6 4 5 5 6 6 8 7 9 8 7 8 4 3 8 10149 050 2 0 0 0 1 1 1 0 2 1 1 0 1 0 2 0 2 1 1 1 1 0 2 121 100 2 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 03 250 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 500 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-88 Table 2.3-22a Annual Frequency of Occurrence of Wind Direction and Wind Speed Versus Precipitation Intensity FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .016 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0 0 1-3 2 2

2 4-7 2 3

1 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 4 5

3 E ESE SE SSE S SSW 0 0

0 0

0 0 1 7

1 4

3 3 4 2

1 6

3 3 0 0

2 4

5 4 0 0

1 4

0 3 0 0

0 1

0 1 0 0

0 0

0 0 0 0

0 0

0 0 5 9

5 21 11 14 SW WSW W WNW NW NNW 0 0

0 0

0 0 1 1

0 0

5 2 3 2

3 5 10 10 4 1

2 7

5 2 1 0

0 0

1 0 0 1

0 0

0 0 0 0

1 0

0 0 0 0

0 0

0 0 9 5

6 12 21 14 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 2

0 0 36 1 1

0 0 60 0 0

0 0 36 0 0

0 0 10 0 0

0 0

3 0 0

0 0

1 0 0

0 1

1 1 3

0 1 149 FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .050 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0

0 1-3 1 1

0 4-7 1 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 2 1

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

1 3

0 2 0 0

0 2

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

1 5

0 2 SW WSW W WNW NW NNW 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 2 1 1 0 1

1 0 3 1 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 1

1 2 4 2 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

2 0 0

0 0

5 0 0

0 0 12 0 0

0 0

2 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0 21 FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .100 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0

0 1-3 0 0

0 4-7 0 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 0 0

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

1 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 1

0 0 SW WSW W WNW NW NNW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 1

0 0 0 0

0 0

0 1 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 1

0 1 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

0 0 0

0 0

1 0 0

0 0

1 0 0

0 0

1 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

3 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-89 Table 2.3-22a Annual Frequency of Occurrence of Wind Direction and Wind Speed Versus Precipitation Intensity (Continued) FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .250 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0

0 1-3 0 0

0 4-7 0 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 0 0

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 SW WSW W WNW NW NNW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .500 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0 0 1-3 0 0

0 4-7 0 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 0 0

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 SW WSW W WNW NW NNW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-90Table 2.3-23 Statistic on Fog at the Hanford Meteorology Station (Based on 1945-1970 Data)* All Fog (viz 0-6 Miles) Dense Fog (viz 1/4 Mile or Less) No. of Days No. of Hours No. of Days No. of Hours Greatest No. of Hours of Persistence J

F M

A M

J J

A S

O N

D Avg 9 6

1

2 8 12 Greatest 19 20 6 1

3 1

1 1

1 9 14 20 Least 0 0

0 0

0 0

0 0

0 0

1 2 Avg 68.3 36.4 4.4 0.3 0.3

0.3 7.6 55.4 105.4 Greatest 193.4 206.2 20.6 2.8 2.7 0.5 0.7 1.0 5.5 63.6 148.0 193.8 Least 0 0

0 0

0 0

0 0

0 0

1.0 6.5 Avg 6 3

1

0 0

1 5

8 Greatest14 11 5 1

1 0

0 1

1 6 13 17 Least 0 0

0 0

0 0

0 0

0 0

0 2 Avg 20.4 12.7 1.8 0.1 0.1 0

0

0.1 3.1 21.1 42.0 Greatest52.4 86.7 7.8 1.8 1.6 0

0 1.0 3.2 35.2 71.4 119.8 Least 0 0

0 0

0 0

0 0

0 0

0 1.3 (9) AF 58.1 58.0 12.2 2.8 2.7 0.5 0.7 0.7 2.6 39.0 65.4 72.3 (10) DF 15.0 16.7 5.0 0

1.6 0

0 0.7 1.4 15.8 20.6 47.0 (1) (2) (3) (4) (5) (6) (7) (8) Y 33 57 22 278.4 462.5 147.7 24 42 2 101.4 201.5 24.3 72.3 47.0 # Less than 1/2 1. Greatest number of days in a season -- occurred in 1969-70 2. Least number of days in a season -- occurred in 1948-49

3. Greatest number of hours in a season -- occurred in 1964-65

4. Least number of hours in a season -- occurred in 1948-49

5. Greatest number of days in a season -- occurred in 1950-51

6. Least number of days in a season -- occurred in 1948-49

7. Greatest number of hours in a season -- occurred in 1962-63

8. Least number of hours in a season -- occurred in 1948-49

9. AF denotes all fog (viz 0-6 miles)

10. DF denotes dense fog (viz 1/4 mile or less). Records for persistence of dense fog did not begin until 1953.

• Summation for the year does not necessarily reflect the summation of individual months.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.3-91 Table 2.3-24 Percent Frequency Distribution of Wind Speeds During Hourly Observations of Fog at Pasco (1966-1970) and at HMS (1960-1970) Speed Class* Station Calm 1-3 4-7 8-12 12 Total HMS(1) 29 44 25 2 0 100 Pasco(2) 61 8 24 6 1 100

• Speed classes are in units of mph for HMS, and in units of knots for Pasco. (1) Statistics for HMS are only for hourly observations of fog restricting visibility to 1/2 mile or less.

(2) Statistics for Pasco are for all hourly observations of fog (visibility 0-6 miles).

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-92Table 2.3-25 Percent Frequency of Occurrence of Stability (T Distribution) at the Hanford Reservation (1) Month/Year/Site Very Unstable Less Than -2.5 Unstable -2.5 to -1.5 t Range (°F/200 ft) Neutral -1.5 to -0.5 Moderately Stable -0.5 to +3.5 Very Stable Greater Than 3.5 4/74 CGS 4/74 HMS APRIL 1955-1970 HMS (hist) 0.14 3.61 5.10 15.69 25.28 20.88 27.78 26.94 30.22 43.33 40.83 39.19 12.36 3.19 4.61 5/74 CGS 5/74 HMS MAY 1955-1970 HMS (hist) 0.27 6.18 8.33 23.39 33.20 22.56 30.51 26.34 30.18 35.89 32.39 34.71 8.06 1.88 4.22 6/74 CGS 6/74 HMS JUNE 1955-1970 HMS (hist) 1.25 7.36 8.60 35.42 33.33 26.25 17.36 24.72 30.75 30.42 31.39 31.45 5.42 3.19 2.95 7/74 CGS 7/74 HMS JULY 1955-1970 HMS (hist) 0.00 6.72 8.74 28.23 30.78 26.31 25.81 28.90 27.69 27.02 30.51 33.42 14.11 3.09 3.84 8/74 CGS 8/74 HMS AUGUST 1955-1970 HMS (hist) 0.00 8.20 7.33 28.09 32.12 23.73 20.83 18.28 26.55 23.79 33.74 37.65 25.54 7.66 4.74 9/74 CGS 9/74 HMS SEPTEMBER 1955-1970 HMS (hist) 0.00 6.94 5.05 21.67 25.69 19.90 20.83 17.64 25.11 21.25 33.06 40.89 35.14 16.67 9.05 10/74 CGS 10/74 HMS OCTOBER 1955-1970 HMS (hist) 0.00 3.36 2.23 14.38 20.16 11.82 18.15 17.74 27.03 25.81 41.26 48.87 38.98 17.47 10.06 11/74 CGS 11/74 HMS NOVEMBER 1955-1970 HMS (hist) 0.00 0.00 0.76 4.58 5.00 6.82 28.06 30.42 31.74 52.22 57.22 53.37 14.44 5.83 7.30 12/74 CGS 12/74 HMS DECEMBER 1955-1970 HMS (hist) 0.00 0.13 0.40 1.75 5.24 4.35 22.72 22.72 36.53 56.18 60.89 50.98 18.15 11.02 7.74 (1)t at CGS is computed from 33 to 245 foot levels; at HMS, t is computed from 50 to 250 foot level.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-93Table 2.3-25 Percent Frequency of Occurrence of Stability (T Distribution) at the Hanford Reservation (1) (Continued) Month/Year/Site Very Unstable Less Than -2.5 Unstable -2.5 to -1.5 t Range (°F/200 ft) Neutral -1.5 to -0.5 Moderately Stable -0.5 to +3.5 Very Stable Greater Than 3.5 1/75 CGS 1/74 HMS (1975 Not Available)

JANUARY 1955-1970 HMS (hist) 0.00 0.13 0.34 2.55 5.65 4.73 30.51 29.30 34.78 53.90 59.54 52.23 10.62 5.11 7.91 2/75 CGS 2/74 HMS (1975 Not Available)

FEBRUARY 1955-1970 HMS (hist) 0.00 0.30 1.51 8.78 14.43 9.29 30.51 26.93 28.24 49.40 51.19 52.05 10.57 7.14 8.90 3/75 CGS 3/74 HMS (1975 Not Available)

MARCH 1955-1970 HMS (hist) 0.13 1.48 3.49 20.03 19.09 15.84 17.34 26.34 28.22 42.07 47.04 45.25 11.96 6.05 6.61 April 1974 - March 1975 CGS 1955-1970 HMS (hist) 0.14 4.32 17.17 16.04 24.25 29.80 38.21 41.84 17.17 6.49 April 1975 -

March 1976 CGS 0.59 21.31 21.85 37.20 17.51 (1)t at CGS is computed from 33 to 245 foot levels; at HMS, t is computed from 50 to 250 foot level.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-94Table 2.3-26 Frequency of Occurrence T (F/200 ft) Versus Time of Day from 4/74 through 3/75 at CGS between 245 and 33 ft Levels Time of Day 1 2 3 4 5 6789101112131415 161718192021222324TOTALLT-2.5 0 0 0 0 0 0000032212 110000000 12GE-2.5 LT-1.5 0 0 0 0 0 0 3 43 98 137 156 175 213 217 196 148 90 271000001504 GE-1.5 LT-0.5 17 16 16 16 18 37 97 137 134 150 168 158 123 123 145 168 181 167 111 52 33 21 18 18 2124GE-0.5 LT-3.5 216 202 193 197 187 188 177 131 76 40 20 16 14 14 14 42 85 156 203 236 235 242 238 225 3347GE-3.5 124 141 148 143 150 133 84 36 9 511111 028417191951021161504UNKNO 8 6 8 9 10 7418483317131297 667966776 269TOTAL 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 8760 Average for Hour 3.008 3.261 2.714 .243 -1.104 -1.432 -1.502 -1.240 -.155 1.656 2.228 2.6852.899 3.226 3.227 1.499 -.654 -1.303 -1.521 -1.441 -.835 .762 2.144 2.383 .883 COLUMBIA GENERATING STATION Amendment53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-95Table 2.3-27 Frequency of Occurrence, Sigma (°) Versus Time of Day from 4/74 through 3/75 at CGS for 33 ft Level Time of Day GE22.5 1 111 2 110 3 105 4 104 5 104 611279681179124101391114412152131521415315 137 1610917 6218 4419 5220 5121 7922 882310724 98TOTAL2550LT22.5 GE17.5 30 33 32 38 33 32342932353944333646 393220212836262741790 LT17.5 GE12.5 43 48 54 52 52 47544846587055686050 5950363439435147411205LT 12.5 GE7.5 104 91 87 74 94 9711211481797179838094 1071441511131121059698882354LT7.5 GE3.75 60 61 64 75 62 56583131181917132327 396592121112908668771365LT3.75 GE2.1 0 5 7 5 4 6100010000 1111138585687LT2.1 8 8 8 7 5 5020000000 00037524569 UNKNO 9 9 8 10 11 10102451362118161311 111111888899340TOTAL 365 365 365 365 365 365365365365365365365365365365 3653653653653653653653653658760 Average for Hour 22.406 23.575 22.42123.03127.39027.76828.29821.89514.19814.65618.66720.99723.638 22.506 22.794 21.73027.37828.12428.87427.136 17.01115.28517.97820.98522.384 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-96Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction PLANT NAME: COLUMBIA GENERATING STATION METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METER TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS A WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .029 .101 .231 .190 .168 .114 .051 .079 .003 .000 .000 .000 .96 .035 .123 .190 .145 .117 .088 .028 .057 .003 .006 .000 .000 .79 .027 .095 .161 .130 .060 .035 .016 .032 .006 .000 .000 .000 .56 .021 .073 .114 .035 .022 .006 .003 .000 .000 .000 .000 .000 .27 .024 .085 .095 .032 .016 .013 .000 .000 .000 .000 .000 .000 .26 .022 .079 .123 .095 .028 .013 .003 .000 .000 .000 .000 .000 .36 .025 .088 .247 .158 .139 .070 .019 .003 .000 .000 .000 .000 .75 .014 .051 .180 .247 .262 .114 .047 .022 .006 .003 .000 .000 .95 .024 .085 .224 .209 .180 .196 .180 .196 .063 .022 .000 .000 1.38 .017 .060 .155 .107 .107 .117 .079 .092 .016 .006 .003 .000 .76 .013 .044 .098 .073 .076 .073 .035 .066 .035 .003 .000 .000 .52 .016 .057 .063 .054 .038 .025 .013 .041 .025 .009 .000 .000 .34 .013 .047 .095 .028 .035 .025 .016 .028 .022 .009 .000 .000 .32 .020 .070 .098 .054 .016 .019 .019 .035 .019 .022 .000 .000 .37 .022 .079 .155 .085 .060 .013 .016 .019 .013 .009 .000 .000 .47 .024 .085 .269 .171 .085 .098 .054 .035 .000 .003 .003 .000 .83 .348 1.223 2.497 1.811 1.410 1.018 .578 .705 .212 .095 .006 .000 9.90 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS B WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .007 .022 .063 .085 .047 .035 .019 .013 .003 .000 .000 .000 .29 .008 .025 .041 .057 .057 .032 .006 .006 .000 .006 .000 .000 .24 .001 .003 .035 .047 .032 .025 .003 .006 .000 .000 .000 .000 .15 .005 .016 .013 .013 .006 .003 .003 .009 .000 .000 .000 .000 .07 .007 .022 .019 .009 .006 .000 .000 .000 .000 .000 .000 .000 .06 .005 .016 .035 .016 .022 .006 .000 .000 .000 .000 .000 .000 .10 .006 .019 .038 .063 .038 .009 .006 .009 .000 .000 .000 .000 .19 .006 .019 .025 .076 .085 .051 .019 .013 .003 .000 .000 .000 .30 .005 .016 .070 .095 .076 .092 .047 .066 .009 .000 .000 .000 .48 .005 .016 .057 .025 .047 .047 .041 .060 .025 .013 .000 .000 .34 .003 .009 .051 .032 .022 .032 .016 .051 .025 .025 .000 .000 .27 .003 .009 .028 .016 .019 .013 .000 .006 .013 .000 .000 .000 .11 .004 .013 .028 .016 .019 .019 .028 .032 .003 .013 .000 .000 .17 .003 .009 .025 .022 .022 .019 .022 .016 .006 .013 .000 .000 .16 .008 .025 .038 .028 .038 .016 .013 .006 .003 .000 .000 .000 .18 .012 .038 .063 .070 .032 .025 .009 .013 .000 .000 .000 .000 .26 .092 .278 .629 .670 .569 .424 .234 .307 .092 .070 .000 .000 3.36 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-97Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS C TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .007 .019 .076 .079 .054 .051 .022 .022 .000 .000 .000 .000 .33 .011 .032 .060 .057 .047 .035 .009 .006 .006 .000 .000 .000 .26 .009 .025 .035 .035 .009 .016 .009 .006 .000 .000 .000 .000 .14 .005 .016 .013 .028 .003 .000 .000 .000 .000 .000 .000 .000 .07 .003 .009 .019 .022 .006 .000 .000 .000 .000 .000 .000 .000 .06 .004 .013 .009 .003 .013 .006 .000 .000 .000 .000 .000 .000 .05 .005 .016 .025 .063 .035 .022 .003 .016 .000 .000 .000 .000 .19 .002 .006 .047 .098 .076 .057 .035 .016 .000 .000 .000 .000 .34 .007 .019 .044 .082 .092 .063 .063 .047 .019 .006 .000 .000 .44 .008 .022 .057 .044 .044 .047 .057 .063 .032 .019 .000 .000 .39 .008 .022 .028 .028 .044 .047 .022 .054 .041 .009 .000 .000 .30 .003 .009 .044 .019 .022 .035 .016 .028 .044 .003 .000 .000 .22 .003 .009 .022 .028 .025 .022 .022 .032 .013 .003 .000 .000 .18 .003 .009 .028 .038 .009 .022 .022 .016 .028 .025 .000 .000 .20 .003 .009 .051 .054 .022 .022 .013 .009 .022 .000 .000 .000 .21 .007 .019 .054 .079 .051 .035 .022 .028 .003 .003 .000 .000 .30 .088 .256 .613 .759 .553 .480 .316 .345 .209 .070 .000 .000 3.69 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS D WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .035 .142 .332 .420 .218 .193 .130 .032 .003 .003 .000 .000 1.51 .025 .101 .215 .231 .186 .101 .047 .038 .025 .003 .000 .000 .97 .020 .082 .168 .171 .126 .107 .051 .013 .019 .013 .006 .000 .78 .018 .073 .104 .079 .060 .019 .000 .006 .000 .000 .000 .000 .36 .012 .051 .117 .073 .057 .016 .000 .000 .000 .000 .000 .000 .33 .010 .041 .101 .092 .082 .022 .016 .003 .000 .000 .000 .000 .37 .021 .085 .205 .193 .218 .133 .051 .013 .003 .000 .000 .000 .92 .018 .073 .322 .401 .395 .303 .136 .120 .009 .000 .000 .000 1.78 .025 .101 .322 .338 .398 .326 .228 .335 .123 .041 .006 .000 2.24 .015 .060 .243 .212 .205 .281 .240 .370 .215 .120 .022 .000 1.98 .031 .126 .136 .168 .161 .142 .107 .202 .142 .101 .016 .000 1.33 .019 .079 .123 .149 .079 .054 .082 .155 .133 .035 .000 .000 .91 .027 .111 .158 .092 .101 .126 .092 .107 .057 .016 .006 .000 .89 .030 .123 .158 .202 .202 .149 .171 .326 .161 .057 .006 .000 1.59 .028 .114 .471 .468 .414 .310 .231 .161 .088 .051 .006 .000 2.34 .031 .126 .405 .455 .408 .265 .149 .155 .047 .009 .009 .000 2.06 .363 1.489 3.581 3.742 3.312 2.547 1.729 2.035 1.027 .449 .079 .000 20.35 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-98Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS E WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .037 .142 .370 .307 .161 .079 .035 .025 .009 .003 .000 .000 1.17 .029 .111 .291 .250 .104 .032 .013 .041 .041 .000 .000 .000 .91 .019 .073 .199 .171 .145 .047 .009 .019 .022 .003 .000 .000 .71 .021 .082 .095 .085 .025 .028 .016 .003 .000 .000 .000 .000 .36 .018 .070 .070 .060 .016 .000 .000 .003 .000 .000 .000 .000 .24 .013 .051 .098 .063 .079 .038 .006 .000 .000 .000 .000 .000 .35 .025 .095 .247 .288 .348 .247 .101 .070 .003 .000 .000 .000 1.42 .029 .111 .411 .544 .670 .525 .288 .224 .009 .000 .000 .000 2.81 .051 .196 .490 .484 .484 .553 .430 .424 .076 .025 .006 .000 3.22 .043 .168 .392 .288 .196 .250 .316 .518 .348 .133 .025 .000 2.68 .045 .174 .281 .228 .199 .164 .199 .224 .196 .082 .016 .000 1.81 .043 .164 .307 .218 .142 .107 .104 .120 .038 .019 .000 .000 1.26 .051 .196 .310 .256 .272 .136 .136 .130 .038 .019 .000 .000 1.54 .074 .284 .446 .480 .455 .509 .442 .477 .202 .063 .006 .000 3.44 .066 .253 .651 .762 .610 .487 .389 .354 .098 .032 .000 .000 3.70 .045 .174 .676 .540 .414 .234 .107 .180 .066 .013 .000 .000 2.45 .607 2.342 5.332 5.022 4.320 3.436 2.592 2.813 1.147 .392 .054 .000 28.06 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS F WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .075 .272 .531 .307 .041 .006 .009 .000 .000 .000 .000 .000 1.24 .055 .199 .446 .205 .025 .003 .000 .000 .000 .000 .000 .000 .93 .037 .136 .221 .126 .070 .009 .000 .000 .000 .000 .000 .000 .60 .016 .057 .095 .051 .032 .009 .000 .000 .000 .000 .000 .000 .26 .016 .057 .044 .025 .006 .000 .000 .000 .000 .000 .000 .000 .15 .014 .051 .076 .032 .013 .006 .000 .000 .000 .000 .000 .000 .19 .020 .073 .209 .174 .269 .111 .028 .013 .000 .000 .000 .000 .90 .035 .126 .512 .604 .582 .414 .092 .066 .006 .000 .000 .000 2.44 .055 .202 .629 .733 .578 .297 .130 .104 .009 .006 .000 .000 2.75 .041 .149 .455 .389 .288 .120 .107 .085 .047 .009 .000 .000 1.69 .049 .177 .303 .205 .117 .051 .032 .032 .003 .006 .000 .000 .97 .057 .209 .265 .183 .088 .051 .016 .016 .000 .003 .000 .000 .89 .065 .237 .322 .164 .142 .101 .051 .006 .003 .000 .000 .000 1.09 .070 .256 .442 .319 .326 .171 .088 .044 .000 .000 .000 .000 1.72 .083 .303 .733 .512 .442 .161 .063 .006 .000 .000 .000 .000 2.31 .072 .262 .670 .528 .177 .073 .013 .013 .000 .000 .000 .000 1.81 .759 2.765 5.954 4.558 3.195 1.583 .629 .386 .070 .025 .000 .000 19.92 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-99Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS G WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .113 .332 .860 .281 .025 .000 .000 .000 .000 .000 .000 .000 1.61 .111 .326 .787 .237 .025 .000 .000 .000 .000 .000 .000 .000 1.49 .068 .199 .335 .180 .060 .009 .000 .000 .000 .000 .000 .000 .85 .030 .088 .092 .044 .019 .006 .003 .000 .000 .000 .000 .000 .28 .020 .060 .019 .003 .003 .000 .000 .000 .000 .000 .000 .000 .11 .022 .063 .019 .000 .000 .000 .000 .000 .000 .000 .000 .000 .10 .027 .079 .139 .114 .028 .009 .000 .000 .000 .000 .000 .000 .40 .054 .158 .357 .493 .307 .136 .032 .006 .003 .000 .000 .000 1.55 .059 .174 .408 .496 .313 .085 .028 .009 .006 .000 .000 .000 1.58 .047 .139 .335 .155 .111 .025 .019 .003 .000 .003 .000 .000 .84 .067 .196 .237 .082 .047 .000 .000 .000 .000 .000 .003 .000 .63 .061 .180 .120 .051 .019 .013 .003 .000 .000 .000 .000 .000 .45 .067 .196 .171 .047 .041 .016 .000 .000 .000 .000 .000 .000 .54 .071 .209 .307 .139 .044 .016 .000 .000 .000 .000 .000 .000 .79 .094 .275 .667 .395 .221 .019 .006 .000 .000 .000 .000 .000 1.68 .134 .392 .796 .405 .101 .003 .000 .000 .000 .000 .000 .000 1.83 1.046 3.066 5.648 3.123 1.365 .338 .092 .019 .009 .003 .003 .000 14.71 WIND MEASURED AT 10.0 METERS WIND SPEED CORRECTED TO THE RELEASE HEIGHT OF 10.0 METERS.

OVERALL WIND DIRECTION FREQUENCY WIND DIRECTION: N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW FREQUENCY: 7.1 5.6 3.8 1.7 1.2 1.5 4.8 10.2 12.1 8.7 5.8 4.2 4.7 8.3 10.9 9.5 OVERALL WIND SPEED FREQUENCY AS MEASURED ON THE TOWER:

MAX. WIND SPEED (M/S): .425 1.006 2.034 3.018 4.001 5.029 6.013 8.024 10.036 13.031 18.038 44.704 WIND SPEED FREQUENCY: 3.30 11.42 24.25 19.68 14.73 9.83 6.17 6.61 2.77 1.10 .14 .00 BUILDING AND RELEASE CHARACTERISTICS:

RELEASE HEIGHT: 10.00 METERS MIXING VOLUME COEFFICIENT: 0.50 BUILDING CROSS-SECTIONAL AREA: 2861.00 SQUARE METERS THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-100Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction PLANT NAME: COLUMBIA GENERATING STATION METEOROLOGICAL INSTRUMENTATION DATA PERIOD: 1984-1989, AVERAGE HOURLY DATA WIND SENSORS HEIGHT: 10.0 METER TYPE OF RELEASE: GROUND LVL RLS DELTA-T HEIGHTS: 245FT, 33FT SOURCE OF DATA: ANNUAL MET DATA COLLECTION 1984-1989 COMMENTS: DATA PROCESSED UNDER-THE SUPPLY SYSTEM QA PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS A WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.002 0.188 0.460 0.095 0.029 0.000 0.000 0.77 0.002 0.102 0.319 0.079 0.061 0.000 0.000 0.56 0.002 0.072 0.140 0.052 0.014 0.000 0.000 0.28 0.000 0.016 0.025 0.002 0.000 0.000 0.000 0.04 0.002 0.038 0.057 0.005 0.000 0.000 0.000 0.10 0.000 0.063 0.125 0.005 0.002 0.000 0.000 0.19 0.000 0.084 0.226 0.041 0.005 0.000 0.000 0.36 0.005 0.138 0.573 0.168 0.034 0.000 0.000 0.92 0.005 0.131 0.613 0.389 0.186 0.000 0.000 1.32 0.000 0.115 0.312 0.231 0.294 0.009 0.002 0.96 0.005 0.100 0.235 0.138 0.213 0.032 0.000 0.72 0.002 0.127 0.211 0.109 0.125 0.000 0.000 0.57 0.000 0.118 0.136 0.054 0.054 0.007 0.000 0.37 0.002 0.129 0.181 0.081 0.104 0.000 0.000 0.50 0.005 0.197 0.299 0.111 0.075 0.000 0.000 0.69 0.005 0.231 0.410 0.086 0.016 0.002 0.000 0.75 0.036 1.850 4.322 1.646 1.211 0.050 0.002 9.12 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS B WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.000 0.038 0.111 0.018 0.016 0.000 0.000 0.18 0.000 0.045 0.061 0.016 0.000 0.000 0.000 0.12 0.000 0.014 0.029 0.007 0.002 0.000 0.000 0.05 0.000 0.007 0.009 0.000 0.000 0.000 0.000 0.02 0.000 0.007 0.007 0.002 0.000 0.000 0.000 0.02 0.002 0.020 0.041 0.005 0.000 0.000 0.000 0.07 0.000 0.027 0.111 0.014 0.002 0.000 0.000 0.15 0.000 0.061 0.172 0.043 0.007 0.000 0.000 0.28 0.000 0.041 0.190 0.070 0.045 0.000 0.000 0.35 0.002 0.050 0.111 0.104 0.072 0.002 0.000 0.34 0.000 0.018 0.063 0.041 0.043 0.000 0.000 0.17 0.002 0.036 0.066 0.045 0.063 0.009 0.000 0.22 0.000 0.054 0.057 0.016 0.020 0.000 0.000 0.15 0.000 0.038 0.059 0.048 0.072 0.005 0.000 0.22 0.002 0.059 0.095 0.016 0.018 0.000 0.000 0.19 0.000 0.043 0.136 0.038 0.011 0.000 0.000 0.23 0.009 0.559 1.318 0.482 0.374 0.016 0.000 2.76 COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-101Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS C TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.000 0.095 0.177 0.061 0.032 0.000 0.000 0.36 0.000 0.059 0.097 0.027 0.005 0.000 0.000 0.19 0.002 0.020 0.070 0.014 0.000 0.000 0.000 0.11 0.000 0.029 0.032 0.000 0.000 0.000 0.000 0.06 0.000 0.020 0.034 0.002 0.002 0.000 0.005 0.06 0.000 0.027 0.059 0.009 0.007 0.000 0.000 0.10 0.000 0.043 0.143 0.023 0.000 0.000 0.000 0.21 0.000 0.102 0.238 0.079 0.020 0.000 0.000 0.44 0.000 0.070 0.188 0.154 0.086 0.000 0.000 0.50 0.002 0.059 0.161 0.106 0.052 0.005 0.000 0.38 0.000 0.079 0.115 0.100 0.054 0.002 0.000 0.35 0.002 0.066 0.136 0.095 0.068 0.007 0.000 0.37 0.000 0.075 0.102 0.075 0.045 0.000 0.002 0.30 0.005 0.100 0.120 0.041 0.091 0.005 0.000 0.36 0.000 0.088 0.170 0.045 0.063 0.000 0.000 0.37 0.000 0.109 0.179 0.029 0.023 0.000 0.000 0.34 0.011 1.041 2.019 0.860 0.548 0.018 0.007 4.50 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS D WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.014 0.469 0.623 0.211 0.109 0.000 0.000 1.42 0.011 0.267 0.387 0.081 0.052 0.000 0.000 0.80 0.005 0.147 0.238 0.038 0.029 0.000 0.000 0.46 0.002 0.081 0.095 0.002 0.011 0.000 0.000 0.19 0.000 0.093 0.140 0.016 0.011 0.000 0.000 0.26 0.002 0.204 0.231 0.048 0.007 0.000 0.000 0.49 0.005 0.213 0.441 0.072 0.032 0.000 0.000 0.76 0.005 0.287 0.847 0.244 0.068 0.000 0.000 1.45 0.002 0.337 0.885 0.414 0.220 0.002 0.000 1.86 0.011 0.283 0.627 0.475 0.387 0.032 0.000 1.82 0.002 0.263 0.414 0.290 0.283 0.011 0.005 1.27 0.016 0.333 0.340 0.201 0.226 0.005 0.002 1.12 0.005 0.355 0.407 0.231 0.177 0.005 0.002 1.18 0.016 0.448 0.586 0.349 0.387 0.032 0.007 1.82 0.011 0.559 0.894 0.240 0.213 0.020 0.005 1.94 0.014 0.534 0.996 0.263 0.170 0.009 0.000 1.99 0.120 4.874 8.152 3.176 2.381 0.115 0.020 18.84 COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-102Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS E WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.016 0.808 0.754 0.125 0.043 0.000 0.000 1.75 0.009 0.521 0.552 0.070 0.050 0.000 0.000 1.20 0.014 0.328 0.494 0.027 0.005 0.000 0.000 0.87 0.014 0.134 0.158 0.034 0.000 0.000 0.000 0.34 0.000 0.154 0.168 0.011 0.002 0.000 0.000 0.34 0.020 0.285 0.412 0.018 0.000 0.000 0.000 0.74 0.011 0.421 0.840 0.127 0.054 0.000 0.000 1.45 0.020 0.521 1.720 0.392 0.170 0.000 0.000 2.82 0.011 0.738 1.684 0.632 0.396 0.009 0.000 3.47 0.020 0.700 1.252 0.580 0.552 0.059 0.002 3.16 0.036 0.616 0.912 0.369 0.292 0.016 0.000 2.24 0.009 0.718 0.810 0.274 0.177 0.002 0.011 2.00 0.014 0.786 0.998 0.441 0.235 0.011 0.000 2.49 0.054 1.035 1.648 0.706 0.480 0.016 0.000 3.94 0.034 1.184 1.813 0.496 0.303 0.007 0.000 3.84 0.043 1.050 1.410 0.310 0.152 0.000 0.000 2.97 0.326 9.997 15.627 4.611 2.911 0.120 0.014 33.61 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS F WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.016 0.752 0.441 0.000 0.000 0.000 0.000 1.21 0.011 0.552 0.274 0.005 0.000 0.000 0.000 0.84 0.005 0.278 0.285 0.009 0.002 0.000 0.000 0.58 0.014 0.131 0.104 0.009 0.000 0.000 0.000 0.26 0.005 0.100 0.070 0.005 0.000 0.000 0.000 0.18 0.009 0.190 0.152 0.005 0.000 0.000 0.000 0.36 0.007 0.333 0.573 0.066 0.036 0.000 0.000 1.01 0.009 0.550 1.288 0.240 0.079 0.005 0.000 2.17 0.018 0.629 1.320 0.242 0.079 0.000 0.000 2.29 0.011 0.557 0.643 0.179 0.052 0.005 0.005 1.45 0.027 0.537 0.430 0.070 0.020 0.002 0.000 1.09 0.020 0.494 0.432 0.034 0.023 0.000 0.000 1.00 0.029 0.552 0.405 0.088 0.018 0.000 0.000 1.09 0.034 0.772 0.815 0.195 0.050 0.000 0.000 1.87 0.014 1.050 1.148 0.113 0.045 0.000 0.018 2.39 0.023 1.021 0.747 0.025 0.000 0.000 0.014 1.83 0.251 8.498 9.128 1.284 0.405 0.011 0.036 19.61 COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-103Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS G WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.016 0.790 0.312 0.007 0.002 0.000 0.032 1.16 0.005 0.686 0.292 0.002 0.009 0.000 0.032 1.03 0.007 0.303 0.240 0.029 0.005 0.000 0.032 0.62 0.005 0.174 0.084 0.005 0.000 0.000 0.023 0.29 0.005 0.091 0.023 0.000 0.000 0.000 0.000 0.12 0.011 0.111 0.059 0.007 0.000 0.000 0.000 0.19 0.014 0.213 0.272 0.011 0.000 0.000 0.000 0.51 0.007 0.385 0.869 0.075 0.014 0.000 0.000 1.35 0.009 0.392 0.645 0.050 0.011 0.011 0.000 1.12 0.014 0.310 0.310 0.014 0.007 0.005 0.000 0.66 0.016 0.267 0.174 0.011 0.000 0.000 0.000 0.47 0.014 0.287 0.104 0.005 0.002 0.000 0.000 0.41 0.007 0.299 0.115 0.005 0.000 0.000 0.000 0.43 0.009 0.473 0.267 0.020 0.005 0.000 0.000 0.77 0.020 0.654 0.453 0.018 0.000 0.000 0.000 1.15 0.027 0.822 0.450 0.000 0.000 0.000 0.007 1.31 0.183 6.257 4.670 0.258 0.054 0.016 0.125 11.56 WIND MEASURED AT 10.0 METERS WIND SPEED CORRECTED TO THE RELEASE HEIGHT OF 10.0 METERS. OVERALL WIND DIRECTION FREQUENCY WIND DIRECTION: N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW FREQUENCY: 6.9 4.7 3.0 1.2 1.1 2.1 4.5 9.4 10.9 8.8 6.3 5.7 6.0 9.5 10.6 9.4 OVERALL WIND SPEED FREQUENCY AS MEASURED ON THE TOWER:

MAX. WIND SPEED (M/S): 0.268 1.341 3.129 5.364 8.047 10.729 11.176 WIND SPEED FREQUENCY: 0.94 33.08 45.23 12.32 7.88 0.35 0.20 BUILDING AND RELEASE CHARACTERISTICS:

RELEASE HEIGHT: 10.00 METERS MIXING VOLUME COEFFICIENT: 0.50 BUILDING CROSS-SECTIONAL AREA: 2766.00 SQUARE METERS THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-104

TABLE 2.3-29 THROUGH TABLE 2.3-32 DELETED COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-105Table 2.3-33 Exclusion Area Boundary Accident /Q Desert Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1.68E-04 1.61E-04 1.13E-04 5.62E-05 2.88E-05 3.14E-05 7.22E-05 1.19E-04 1.30E-04 1.09E-04 1.20E-04 1.14E-04 1.25E-04 1.39E-04 1.59E-04 1.81E-04 1.08E-04 1.02E-04 7.01E-05 3.38E-05 1.80E-05 1.94E-05 4.41E-05 7.70E-05 8.49E-05 6.85E-05 7.40E-05 6.94E-05 7.65E-05 8.76E-05 1.04E-04 1.18E-04 8.69E-05 8.16E-05 5.51E-05 2.63E-05 1.42E-05 1.53E-05 3.45E-05 6.20E-05 6.86E-05 5.45E-05 5.81E-05 5.41E-05 6.00E-05 6.94E-05 8.44E-05 9.52E-05 5.39E-05 5.00E-05 3.27E-05 1.51E-05 8.52E-06 9.06E-06 2.02E-05 3.87E-05 4.32E-05 3.31E-05 3.44E-05 3.16E-05 3.53E-05 4.20E-05 5.34E-05 5.98E-05 2.71E-05 2.48E-05 1.55E-05 6.88E-06 4.09E-06 4.29E-06 9.39E-06 1.97E-05 2.23E-05 1.62E-05 1.62E-05 1.46E-05 1.65E-05 2.04E-05 2.77E-05 3.07E-05 1.17E-05 1.05E-05 6.20E-06 2.62E-06 1.67E-06 1.72E-06 3.67E-06 8.64E-06 9.87E-06 6.73E-06 6.46E-06 5.66E-06 6.50E-06 8.41E-06 1.24E-05 1.36E-05 38.6 389.5 22.0 10.4 7.6 7.5 10.0 20.3 23.5 17.9 23.8 22.7 25.1 27.9 34.5 43.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 1.81E-04 TOTAL HOURS AROUND SITE: 724.9 SRP 2.3.4 1950. 1.69E-04 1.12E-04 9.06E-05 5.76E-05 3.01E-05 1.36E-05 SITE LIMIT 1.69E-04 1.12E-04 9.06E-055.76E-05 3.01E-05 1.36E-05 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-106 Table 2.3-33a Exclusion Area Boundary /Q Values Desert Sigmas w/ Meander Direction From Site 0.5% Level(a) (10-4 sec/m3) 5% Level(b) (10-4 sec/m3) S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1.68 1.61 1.13 0.562 0.288 0.314 0.722 1.19 1.30 1.09 1.20 1.14 1.25 1.39 1.59 1.81 2.04 2.26 2.13 2.20 2.19 1.93 1.17 1.18 1.17 1.18 1.74 2.03 2.00 1.58 1.52 1.86 (a) Exceeded 0.5% of the total time. (b) Exceeded 5% of the time that wind blows into the individual sector.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-107Table 2.3-34 Exclusion Area Boundary Accident /Q P-G Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950. 1.67E-041.59E-041.15E-045.48E-052.52E-052.85E-057.40E-051.30E-041.38E-041.08E-041.09E-041.01E-041.10E-041.24E-041.59E-041.77E-04 8.92E-058.36E-055.89E-052.81E-051.39E-051.54E-053.92E-057.05E-057.60E-055.86E-055.81E-055.32E-055.87E-056.83E-058.86E-059.68E-05 6.53E-056.06E-054.21E-052.01E-051.03E-051.13E-052.85E-055.20E-055.65E-054.31E-054.24E-053.87E-054.29E-055.07E-056.61E-057.16E-05 3.32E-053.01E-052.04E-059.75E-065.39E-065.80E-061.43E-052.68E-052.97E-052.22E-052.15E-051.94E-052.17E-052.65E-053.51E-053.72E-05 1.25E-051.10E-057.20E-063.45E-062.12E-062.22E-065.29E-061.04E-051.18E-058.56E-068.07E-067.19E-068.18E-061.05E-051.41E-051.45E-05 3.82E-063.23E-062.01E-069.65E-076.80E-076.87E-071.57E-063.24E-063.81E-062.67E-062.44E-062.14E-062.47E-063.37E-064.63E-064.59E-06 38.9385.621.08.66.16.39.222.825.517.219.918.920.723.235.243.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 1.77E-04 TOTAL HOURS AROUND SITE: 702.8 SRP 2.3.4 1950. 2.86E-04 1.45E-04 1.03E-04 4.91E-05 1.70E-05 4.63E-06 SITE LIMIT 1.65E-04 9.16E-05 6.82E-05 3.59E-05 1.43E-05 4.63E-06 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-108 Table 2.3-34a Exclusion Area Boundary /Q Values Pasquill-Gifford Sigmar w/ Meander and Building Wake Credit Direction From Site 0.5% Level(a) (10-4 sec/m3) 5% Level(b) (10-4 sec/m3) S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1.67 1.59 1.15 0.548 0.252 0.285 0.740 1.30 1.38 1.08 1.09 1.01 1.10 1.24 1.59 1.77 1.99 2.18 2.02 1.96 1.93 1.71 1.14 1.29 1.25 1.17 1.53 1.80 1.77 1.38 1.52 1.82 (a) Exceeded 0.5% of the total time. (b) Exceeded 5% of the time that wind blows into the individual sector.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-109Table 2.3-35 Low Population Zone Accident /Q Desert Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWNWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 8.35E-05 7.96E-05 5.52E-05 2.18E-05 7.98E-06 8.94E-06 2.94E-05 5.22E-05 5.78E-05 5.01E-05 5.49E-05 5.04E-05 5.66E-05 6.26E-05 7.62E-05 8.91E-05 4.58E-05 4.33E-05 2.92E-05 1.16E-05 4.64E-06 5.13E-06 1.57E-05 2.93E-05 3.26E-05 2.71E-05 2.92E-05 2.66E-05 2.99E-05 3.39E-05 4.27E-05 4.95E-05 3.39E-05 3.19E-05 2.12E-05 8.48E-06 3.54E-06 3.89E-06 1.15E-05 2.20E-05 2.45E-05 1.99E-05 2.12E-05 1.93E-05 2.17E-05 2.50E-05 3.20E-05 3.69E-05 1.76E-05 1.64E-05 1.06E-05 4.28E-06 1.97E-06 2.13E-06 5.81E-06 1.17E-05 1.31E-05 1.03E-05 1.07E-05 9.60E-06 1.09E-05 1.28E-05 1.70E-05 1.95E-05 6.92E-06 6.36E-06 3.94E-06 1.61E-06 8.46E-07 8.96E-07 2.19E-06 4.78E-06 5.38E-06 3.95E-06 3.98E-06 3.53E-06 4.02E-06 4.94E-06 6.91E-06 7.81E-06 2.20E-06 1.99E-06 1.17E-06 4.85E-07 3.02E-07 3.11E-07 6.61E-07 1.59E-06 1.80E-06 1.23E-06 1.19E-06 1.04E-06 1.19E-06 1.54E-06 2.29E-06 2.55E-06 39.1 364.8 22.2 9.8 7.0 7.2 9.1 18.0 21.1 16.7 22.7 21.6 23.7 25.3 33.4 43.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 8.91E-05 TOTAL HOURS AROUND SITE: 685.7 SRP 2.3.4 4827. 7.96E-05 4.51E-05 3.39E-05 1.83E-05 7.54E-06 2.55E-06 SITE LIMIT 7.96E-05 4.51E-05 3.39E-05 1.83E-05 7.54E-06 2.55E-06 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-110Table 2.3-36 Low Population Zone Accident /Q P-G Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWNWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 7.65E-05 7.30E-05 5.16E-05 2.17E-05 8.35E-06 9.39E-06 3.16E-05 5.63E-05 6.01E-05 4.77E-05 4.98E-05 4.56E-05 5.08E-05 5.64E-05 7.21E-05 8.17E-05 3.43E-05 3.21E-05 2.22E-05 9.52E-06 4.05E-06 4.48E-06 1.42E-05 2.59E-05 2.81E-05 2.18E-05 2.23E-05 2.03E-05 2.28E-05 2.61E-05 3.38E-05 3.74E-05 2.30E-05 2.13E-05 1.46E-05 6.31E-06 2.83E-06 3.10E-06 9.49E-06 1.76E-05 1.92E-05 1.48E-05 1.49E-05 1.35E-05 1.52E-05 1.78E-05 2.31E-05 2.53E-05 9.64E-06 8.74E-06 5.85E-06 2.59E-06 1.29E-06 1.39E-06 3.97E-06 7.56E-06 8.42E-06 6.32E-06 6.22E-06 5.62E-06 6.37E-06 7.71E-06 1.02E-05 1.08E-05 2.77E-06 2.43E-06 1.57E-06 7.19E-07 4.19E-07 4.38E-07 1.14E-06 2.25E-06 2.58E-06 1.87E-06 1.78E-06 1.59E-06 1.82E-06 2.32E-06 3.12E-06 3.21E-06 6.01E-07 5.08E-07 3.16E-07 1.50E-07 1.06E-07 1.07E-07 2.46E-07 5.13E-07 6.05E-07 4.21E-07 3.84E-07 3.40E-07 3.94E-07 5.36E-07 7.35E-07 7.24E-07 38.9 379.7 20.9 9.2 6.5 6.7 9.1 21.4 24.0 16.8 21.1 20.1 22.1 23.6 34.6 43.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 8.17E-05 TOTAL HOURS AROUND SITE: 698.5 SRP 2.3.4 4827. 1.15E-04 4.99E-05 3.28E-05 1.33E-05 3.61E-06 7.35E-07 SITE LIMIT 7.53E-05 3.50E-05 2.39E-05 1.04E-05 3.16E-06 7.35E-07 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-111Table 2.3-37 Control Room, Exclusion Area Boundary and Low Population Zone /Qs (S/m3) Control Room(1) LPZ(2) EAB(2) Filtered Unfiltered SGT Roofline Railway Bay doors SC Leakage RBW SC Leakage Turbine Building SGT Roofline Railway Bay doors SC Leakage RBW SC Leakage Turbine Building 0 - 2 hrs 1.43E-04 3.65E-04 1.99E-04 8.81E-04 6.95E-04 5.34E-04 8.69E-04 4.70E-03 4.95E-05 1.81E-04 2 - 8 hrs 1.05E-04 2.89E-04 1.44E-04 3.75E-04 3.36E-04 1.97E-04 4.40E-04 2.00E-03 4.95E-05 8 - 24 hrs 4.14E-05 1.18E-04 5.73E-05 1.93E-04 1.28E-04 8.41E-05 1.75E-04 1.03E-03 3.69E-05 1 - 4 days 3.52E-05 9.83 E-05 5.00E-05 1.50E-04 9.72E-05 7.26E-05 1.38E-04 8.01E-04 1.95E-05 4 - 30 days 3.03E-05 8.61E-05 4.18E-05 1.44E-04 7.69E-05 7.00E-05 1.10E-04 7.69E-04 7.81E-06 (1) Reference 2.3-37 (2) Reference 2.3-38 NOTE: EAB = Exclusion Area Boundary LPZ = Low Population Zone SGT = Standby Gas Treatment SC = Secondary Containment RBW = Reactor Building Wall COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-112Table 2.3-38a CGS Calculation, Terrain Features, Desert Sigmas CGS TURBINE AND RADWASTE BLDGS NO DECAY, UNDEPLETED CORRECTED USING STANDARD OPEN TERRAIN FACTORS ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 0.250 0.500 0.750 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1.170E-04 8.738E-05 5.041E-05 2.672E-05 1.743E-05 3.424E-05 5.972E-05 1.094E-04 1.148E-04 9.052E-05 7.851E-05 7.545E-05 8.001E-05 1.238E-04 1.508E-04 1.535E-04 4.880E-05 3.691E-05 2.119E-05 1.129E-05 7.139E-06 1.390E-05 2.452E-05 4.499E-05 4.680E-05 3.669E-05 3.196E-05 3.053E-05 3.243E-05 5.040E-05 6.203E-05 6.378E-05 2.943E-05 2.243E-05 1.282E-05 6.851E-06 4.257E-06 8.233E-06 1.463E-05 2.691E-05 2.783E-05 2.171E-05 1.896E-05 1.805E-05 1.917E-05 2.986E-05 3.703E-05 3.835E-05 1.612E-05 1.234E-05 7.028E-06 3.769E-06 2.314E-06 4.450E-06 7.962E-06 1.468E-05 1.514E-05 1.174E-05 1.029E-05 9.773E-06 1.038E-05 1.617E-05 2.016E-05 2.097E-05 7.145E-06 5.502E-06 3.117E-06 1.679E-06 1.015E-06 1.936E-06 3.496E-06 6.471E-06 6.639E-06 5.115E-06 4.493E-06 4.260E-06 4.517E-06 7.040E-06 8.853E-06 9.262E-06 4.144E-06 3.204E-06 1.808E-06 9.761E-07 5.849E-07 1.109E-06 2.014E-06 3.738E-06 3.821E-06 2.930E-06 2.578E-06 2.442E-06 2.585E-06 4.029E-06 5.097E-06 5.358E-06 2.767E-06 2.146E-06 1.207E-06 6.527E-07 3.886E-07 7.331E-07 1.337E-06 2.487E-06 2.536E-06 1.937E-06 1.706E-06 1.615E-06 1.708E-06 2.662E-06 3.383E-06 3.569E-06 2.013E-06 1.565E-06 8.781E-07 4.753E-07 2.817E-07 5.293E-07 9.689E-07 1.805E-06 1.836E-06 1.399E-06 1.233E-06 1.167E-06 1.232E-06 1.920E-06 2.449E-06 2.593E-06 1.551E-06 1.208E-06 6.766E-07 3.666E-07 2.164E-07 4.053E-07 7.440E-07 1.388E-06 1.409E-06 1.071E-06 9.443E-07 8.935E-07 9.420E-07 1.469E-06 1.879E-06 1.995E-06 1.246E-06 9.718E-07 5.432E-07 2.945E-07 1.733E-07 3.237E-07 5.955E-07 1.112E-06 1.128E-06 8.551E-07 7.543E-07 7.136E-07 7.514E-07 1.172E-06 1.503E-06 1.600E-06 1.031E-06 8.058E-07 4.497E-07 2.439E-07 1.431E-07 2.667E-07 4.917E-07 9.193E-07 9.305E-07 7.045E-07 6.216E-07 5.881E-07 6.185E-07 9.644E-07 1.241E-06 1.323E-06 ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 5.000 7.500 10.000 15.000 20.000 25.000 30.000 35.000 40.000 45.000 50.000 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 8.745E-07 6.840E-07 3.812E-07 2.068E-07 1.211E-07 2.252E-07 4.159E-07 7.782E-07 7.867E-07 5.948E-07 5.248E-07 4.965E-07 5.217E-07 8.135E-07 1.049E-06 1.120E-06 4.911E-07 3.859E-07 2.140E-07 1.162E-07 6.750E-08 1.245E-07 2.313E-07 4.434E-07 4.368E-07 3.285E-07 2.900E-07 2.744E-07 2.872E-07 4.479E-07 5.821E-07 6.263E-07 3.377E-07 2.662E-07 1.471E-07 7.994E-08 4.618E-08 8.474E-08 1.580E-07 2.973E-07 2.979E-07 2.234E-07 1.972E-07 1.866E-07 1.947E-07 3.038E-07 3.970E-07 4.294E-07 2.095E-07 1.658E-07 9.121E-08 4.960E-08 2.846E-08 5.184E-08 9.714E-08 1.832E-07 1.827E-07 1.364E-07 1.204E-07 1.140E-07 1.184E-07 1.849E-07 2.435E-07 2.653E-07 1.494E-07 1.186E-07 6.504E-08 3.536E-08 2.021E-08 3.662E-08 6.883E-08 1.301E-07 1.292E-07 9.622E-08 8.490E-08 8.045E-08 8.330E-08 1.301E-07 1.722E-07 1.886E-07 1.150E-07 9.147E-08 5.005E-08 2.721E-08 1.550E-08 2.799E-08 5.272E-08 9.973E-08 9.881E-08 7.345E-08 6.478E-08 6.141E-08 6.343E-08 9.912E-08 1.317E-07 1.448E-07 9.290E-08 7.402E-08 4.042E-08 2.197E-08 1.249E-08 2.249E-08 4.242E-08 8.032E-08 7.940E-08 5.895E-08 5.196E-08 4.929E-08 5.080E-08 7.942E-08 1.059E-07 1.168E-07 7.760E-08 6.191E-08 3.376E-08 1.835E-08 1.041E-08 1.870E-08 3.532E-08 6.692E-08 6.604E-08 4.898E-08 4.316E-08 4.095E-08 4.214E-08 6.590E-08 8.809E-08 9.740E-08 6.641E-08 5.304E-08 2.889E-08 1.570E-08 8.897E-09 1.595E-08 3.014E-08 5.714E-08 5.630E-08 4.172E-08 3.675E-08 3.489E-08 3.584E-08 5.607E-08 7.511E-08 8.325E-08 5.789E-08 4.628E-08 2.518E-08 1.368E-08 7.744E-09 1.386E-08 2.621E-08 4.927E-08 4.892E-08 3.623E-08 3.189E-08 3.029E-08 3.108E-08 4.863E-08 6.527E-08 7.248E-08 5.121E-08 4.097E-08 2.227E-08 1.209E-08 6.841E-09 1.222E-08 2.314E-08 4.390E-08 4.314E-08 3.193E-08 2.810E-08 2.670E-08 2.736E-08 4.282E-08 5.757E-08 6.405E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-113Table 2.3-38b CGS Calculation, Terrain Features, Desert Sigmas

CGS TURBINE AND RADWASTE BLDGS NO DECAY, UNDEPLETED CHI/Q (SEC/METER CUBED) FOR EACH SEGMENT SEGMENT BOUNDARIES IN MILES FROM THE SITE DIRECTION FROM SITE .5-1 1-2 2-3 3-4 4-5 5-10 10-20 20-30 30-40 40-50 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 2.782E-05 2.117E-05 1.211E-05 6.468E-06 4.034E-06 7.812E-06 1.386E-05 2.549E-05 2.640E-05 2.061E-05 1.800E-05 1.715E-05 1.821E-05 2.834E-05 3.509E-05 3.628E-05 7.806E-06 6.000E-06 3.404E-06 1.831E-06 1.113E-06 2.127E-06 3.830E-06 7.081E-06 7.275E-06 5.617E-06 4.929E-06 4.677E-06 4.961E-06 7.730E-06 9.967E-06 1.013E-05 2.832E-06 2.195E-06 1.236E-06 6.680E-07 3.982E-07 7.518E-07 1.370E-06 2.548E-06 2.599E-06 1.986E-06 1.749E-06 1.656E-06 1.751E-06 2.730E-06 3.466E-06 3.656E-06 1.567E-06 1.220E-06 6.834E-07 3.702E-07 2.186E-07 4.096E-07 7.517E-07 1.402E-06 1.424E-06 1.082E-06 9.543E-07 9.030E-07 9.521E-07 1.484E-06 1.899E-06 2.015E-06 1.037E-06 8.099E-07 4.521E-07 2.451E-07 1.439E-07 2.682E-07 4.944E-07 9.242E-07 9.356E-07 7.085E-07 6.251E-07 5.914E-07 6.221E-07 9.699E-07 1.247E-06 1.330E-06 5.081E-07 3.989E-07 2.214E-07 1.202E-07 6.994E-08 1.292E-07 2.397E-07 4.498E-07 4.528E-07 3.410E-07 3.009E-07 2.848E-07 2.982E-07 4.651E-07 6.035E-07 6.485E-07 2.113E-07 1.671E-07 9.199E-08 5.001E-08 2.873E-08 5.239E-08 9.809E-08 1.849E-07 1.845E-07 1.379E-07 1.217E-07 1.152E-07 1.198E-07 1.870E-07 2.459E-07 2.677E-07 1.153E-07 9.172E-08 5.019E-08 2.729E-08 1.555E-08 2.809E-08 5.290E-08 1.001E-07 9.915E-08 7.372E-08 6.502E-08 6.164E-08 6.368E-08 9.951E-08 1.322E-07 1.453E-07 7.771E-08 6.199E-08 3.381E-08 1.837E-08 1.043E-08 1.873E-08 3.538E-08 6.703E-08 6.615E-08 4.906E-08 4.323E-08 4.103E-08 4.221E-08 6.602E-08 8.823E-08 9.755E-08 5.794E-08 4.631E-08 2.520E-08 1.369E-08 7.751E-09 1.387E-08 2.624E-08 4.976E-08 4.897E-08 3.626E-08 3.193E-08 3.032E-08 3.111E-08 4.868E-08 6.534E-08 7.255E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-114Table 2.3-38c CGS Calculation, Terrain Features, Desert Sigmas CGS TURBINE AND RADWASTE BLDGS - SPECIFIC POINTS OF INTEREST RELEASE ID TYPE OF LOCATION DIRECTION FROM SITE DISTANCE X/Q X/Q X/Q D/Q (MILES) (METERS) (SEC/CUB.METER) NO DECAY UNDEPLETED (SEC/CUB.METER) 2.260 DAY DECAY UNDEPLETED (SEC/CUB.METER) 8.000 DAY DECAY DEPLETED (PER SQ.METER) A A A

A A

A A

A A

A A

A A

A A

A A

A A

A A

A A

A A A A A

A A

A A

A A

A A

A A

A A PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

EAB (1950 M) EAB (1950 M) EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M) SE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE SE SE ESE ENE NNE ESE SE SE NE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 6.40 3.90 4.00 4.10 4.20 4.30 4.40 4.50 3.00 3.10 3.21 3.30 3.40 3.50 3.60 15.00 4.80 4.20 4.10 4.30 0.10 9.59 8.29 4.30 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 10298. 6275.

6436.

6597.

6758.

6919.

7080.

7241.

4827.

4988.

5159.

5310.

5471.

5632.

5792. 24135. 7723.

6758.

6597.

6918. 160. 15437.

13346. 6919.

1950. 1950. 1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950. 7.2E-07 1.2E-06 1.2E-06 1.1E-06 1.1E-06 1.0E-06 1.0E-06 9.6E-07 1.9E-06 1.8E-06 1.7E-06 1.6E-06 1.5E-06 1.5E-06 1.4E-06 2.4E-07 1.1E-06 1.1E-06 6.9E-07 7.6E-07 4.1E-04 4.2E-07 5.1E-07 6.7E-07 1.1E-05 8.4E-06 4.8E-06 2.6E-06 1.6E-06 3.0E-06 5.4E-06 9.9E-06 1.0E-05 7.9E-06 6.9E-06 6.6E-06 7.0E-06 1.1E-05 1.4E-05 1.4E-05 6.8E-07 1.2E-06 1.1E-06 1.1E-06 1.0E-06 1.0E-06 9.6E-07 9.2E-07 1.9E-06 1.8E-06 1.7E-06 1.6E-06 1.5E-06 1.4E-06 1.4E-06 2.1E-07 1.1E-06 1.0E-06 6.5E-07 7.3E-07 4.1E-04 3.9E-07 4.7E-07 6.3E-07 1.1E-05 8.3E-06 4.7E-06 2.5E-06 1.5E-06 2.9E-06 5.3E-06 9.8E-06 1.0E-05 7.8E-06 6.8E-06 6.5E-06 6.9E-06 1.1E-05 1.3E-05 1.4E-05 5.1E-07 9.3E-07 8.9E-07 8.5E-07 8.1E-07 7.8E-07 7.5E-07 7.2E-07 1.5E-06 1.4E-06 1.3E-06 1.3E-06 1.2E-06 1.1E-06 1.1E-06 1.5E-07 8.3E-07 8.1E-07 5.2E-07 5.7E-07 4.0E-04 2.8E-07 3.5E-07 5.0E-07 9.4E-06 7.2E-06 4.1E-06 2.2E-06 1.3E-06 2.6E-06 4.6E-06 8.5E-06 8.8E-06 6.8E-06 5.9E-06 5.6E-06 6.0E-06 9.3E-06 1.2E-05 1.2E-05 2.6E-10 7.0E-10 6.6E-10 6.3E-10 6.0E-10 5.7E-10 5.4E-10 5.1E-10 1.3E-09 1.2E-09 1.1E-09 1.0E-09 9.6E-10 9.0E-10 8.4E-10 6.0E-11 4.9E-10 6.0E-10 3.7E-10 5.1E-10 8.4E-07 1.3E-10 1.7E-10 3.7E-10 7.9E-09 5.5E-09 3.5E-09 1.4E-09 1.3E-09 2.5E-09 5.2E-09 1.1E-08 1.3E-08 1.0E-08 7.3E-09 6.7E-09 7.0E-09 1.1E-08 1.2E-08 1.1E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-115Table 2.3-38d CGS Calculation, Terrain Features, Desert Sigmas CGS REACTOR BLDG NO DECAY, UNDEPLETED CORRECTED USING STANDARD OPEN TERRAIN FACTORS ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 0.250 0.500 0.750 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 3.983E-07 3.015E-07 2.241E-07 9.654E-08 3.448E-08 7.411E-08 2.513E-07 7.930E-07 1.124E-06 1.049E-06 6.008E-07 4.892E-07 5.015E-07 9.120E-07 6.666E-07 4.473E-07 5.147E-07 3.460E-07 2.226E-07 7.983E-08 7.360E-08 1.508E-07 3.020E-07 7.233E-07 8.905E-07 7.337E-07 4.702E-07 5.305E-07 5.031E-07 7.571E-07 6.348E-07 5.728E-07 4.459E-07 2.917E-07 1.853E-07 7.694E-08 7.682E-08 1.476E-07 2.641E-07 5.856E-07 6.762E-07 5.603E-07 3.787E-07 4.710E-07 4.747E-07 6.975E-07 5.775E-07 5.291E-07 2.855E-07 1.836E-07 1.175E-07 5.258E-08 5.380E-08 1.017E-07 1.670E-07 3.550E-07 4.031E-07 3.353E-07 2.340E-07 3.229E-07 3.390E-07 4.987E-07 3.846E-07 3.498E-07 1.417E-07 8.972E-08 5.986E-08 2.801E-08 2.883E-08 5.532E-08 8.155E-08 1.649E-07 1.877E-07 1.577E-07 1.123E-07 2.809E-07 3.184E-07 4.778E-07 2.045E-07 1.780E-07 8.546E-08 5.399E-08 3.986E-08 1.857E-08 1.888E-08 3.697E-08 4.940E-08 9.701E-08 1.113E-07 9.422E-08 6.758E-08 3.180E-07 3.702E-07 5.635E-07 1.394E-07 1.089E-07 6.007E-08 3.809E-08 3.227E-08 1.473E-08 1.476E-08 2.952E-08 3.530E-08 6.783E-08 7.839E-08 6.677E-08 4.829E-08 3.667E-07 4.232E-07 6.623E-07 1.150E-07 7.782E-08 4.723E-08 3.012E-08 2.901E-08 1.300E-08 1.283E-08 2.619E-08 2.826E-08 5.335E-08 6.206E-08 5.308E-08 3.883E-08 5.692E-07 6.426E-07 1.026E-06 1.046E-07 6.216E-08 3.955E-08 2.537E-08 2.518E-08 1.120E-08 1.088E-08 2.256E-08 2.409E-08 4.477E-08 5.232E-08 4.498E-08 4.067E-08 1.128E-06 1.325E-06 1.950E-06 2.207E-07 5.287E-08 3.450E-08 2.223E-08 2.229E-08 9.892E-09 9.460E-09 1.990E-08 2.133E-08 3.913E-08 4.585E-08 3.965E-08 4.490E-08 1.019E-06 1.054E-06 1.650E-06 7.638E-07 4.674E-08 3.085E-08 1.996E-08 2.000E-08 8.868E-09 8.362E-09 1.781E-08 1.931E-08 4.183E-08 4.113E-08 4.297E-08 8.482E-08 8.387E-07 8.662E-07 1.356E-06 6.314E-07 4.227E-08 ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 5.000 7.500 10.000 15.000 20.000 25.000 30.000 35.000 40.000 45.000 50.000 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 2.814E-08 1.825E-08 1.814E-08 8.058E-09 7.499E-09 1.613E-08 1.778E-08 4.509E-08 3.754E-08 4.676E-08 2.656E-07 7.075E-07 7.296E-07 1.143E-06 5.345E-07 3.896E-08 2.023E-08 1.646E-08 1.472E-08 6.624E-09 4.948E-09 1.203E-08 1.734E-08 2.990E-08 4.858E-08 4.163E-07 4.104E-07 3.901E-07 4.000E-07 6.275E-07 2.974E-07 3.642E-08 1.577E-08 1.027E-08 6.195E-08 2.853E-08 3.627E-09 1.269E-08 1.283E-08 2.199E-08 4.276E-07 3.178E-07 2.789E-07 2.653E-07 2.710E-07 1.652E-07 2.034E-07 2.261E-08 3.200E-07 2.576E-07 1.393E-07 7.526E-08 4.242E-08 7.524E-08 1.423E-07 2.697E-07 2.625E-07 1.945E-07 1.705E-07 1.623E-07 1.650E-07 2.594E-07 3.525E-07 3.975E-07 2.287E-07 1.846E-07 9.960E-08 5.376E-08 3.020E-08 5.333E-08 1.011E-07 1.919E-07 1.860E-07 1.376E-07 1.205E-07 1.148E-07 1.163E-07 1.830E-07 2.499E-07 2.834E-07 1.764E-07 1.427E-07 7.682E-08 4.145E-08 2.323E-08 4.089E-08 7.760E-08 1.474E-07 1.425E-07 1.053E-07 9.214E-08 8.786E-08 8.872E-08 1.398E-07 1.916E-07 2.181E-07 1.428E-07 1.156E-07 6.218E-08 3.353E-08 1.876E-08 3.294E-08 6.258E-08 1.190E-07 1.148E-07 8.473E-08 7.408E-08 7.067E-08 7.121E-08 1.123E-07 1.544E-07 1.762E-07 1.195E-07 9.686E-08 5.202E-08 2.804E-08 1.567E-08 2.746E-08 5.221E-08 9.930E-08 9.564E-08 7.055E-08 6.164E-08 5.884E-08 5.918E-08 9.334E-08 1.287E-07 1.473E-07 1.024E-07 8.309E-08 4.458E-08 2.402E-08 1.341E-08 2.346E-08 4.463E-08 8.493E-08 8.168E-08 6.022E-08 5.259E-08 5.021E-08 5.043E-08 7.958E-08 1.099E-07 1.261E-07 8.938E-08 7.259E-08 3.891E-08 2.096E-08 1.169E-08 2.042E-08 3.888E-08 7.401E-08 7.108E-08 5.238E-08 4.572E-08 4.367E-08 4.380E-08 6.915E-08 9.568E-08 1.099E-07 7.915E-08 6.433E-08 3.446E-08 1.856E-08 1.034E-08 1.805E-08 3.437E-08 6.544E-08 6.278E-08 4.625E-08 4.035E-08 3.855E-08 3.862E-08 6.099E-08 8.452E-08 9.728E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-116Table 2.3-38e CGS Calculation, Terrain Features, Desert Sigmas CGS REACTOR BLDG NO DECAY, UNDEPLETED CHI/Q (SEC/METER CUBED) FOR EACH SEGMENT SEGMENT BOUNDARIES IN MILES FROM THE SITE DIRECTION FROM SITE .5-1 1-2 2-3 3-4 4-5 5-10 10-20 20-30 30-40 40-50 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 3.899E-07 2.557E-07 1.635E-07 6.676E-08 6.588E-08 1.279E-07 2.294E-07 5.137E-07 6.024E-07 4.988E-07 3.347E-07 4.184E-07 4.207E-07 6.224E-07 5.045E-07 4.591E-07 1.486E-07 9.471E-08 6.378E-08 2.927E-08 2.996E-08 5.746E-08 8.625E-08 1.770E-07 2.016E-07 1.690E-07 1.195E-07 3.067E-07 3.460E-07 5.205E-07 2.156E-07 1.855E-07 6.171E-08 3.914E-08 3.299E-08 1.506E-08 1.509E-08 3.018E-08 3.624E-08 6.982E-08 8.063E-08 6.861E-08 4.965E-08 4.347E-07 4.968E-07 7.813E-07 1.174E-07 7.985E-08 3.982E-08 2.553E-08 2.517E-08 1.122E-08 1.090E-08 2.258E-08 2.423E-08 4.507E-08 5.264E-08 4.526E-08 4.175E-08 9.267E-07 1.027E-06 1.572E-06 3.944E-07 5.319E-08 3.093E-08 2.000E-08 1.999E-08 8.872E-09 8.368E-09 1.781E-08 1.934E-08 4.224E-08 4.120E-08 4.339E-08 1.400E-07 8.436E-07 8.714E-07 1.364E-06 6.347E-07 4.237E-08 2.000E-08 1.411E-08 3.647E-08 1.668E-08 4.928E-09 1.324E-08 1.543E-08 2.976E-08 2.146E-07 2.904E-07 3.198E-07 4.052E-07 4.159E-07 5.365E-07 3.083E-07 3.085E-08 2.118E-07 1.702E-07 1.045E-07 5.532E-08 2.837E-08 5.160E-08 9.519E-08 1.801E-07 2.652E-07 1.966E-07 1.723E-07 1.641E-07 1.669E-07 2.045E-07 2.738E-07 2.635E-07 1.769E-07 1.431E-07 7.704E-08 4.156E-08 2.330E-08 4.103E-08 7.785E-08 1.479E-07 1.430E-07 1.057E-07 9.247E-08 8.817E-08 8.906E-08 1.403E-07 1.923E-07 2.188E-07 1.196E-07 9.698E-08 5.209E-08 2.808E-08 1.569E-08 2.750E-08 5.228E-08 9.945E-08 9.579E-08 7.066E-08 6.174E-08 5.893E-08 5.928E-08 9.350E-08 1.289E-07 1.475E-07 8.944E-08 7.264E-08 3.894E-08 2.098E-08 1.170E-08 2.044E-08 3.891E-08 7.407E-08 7.115E-08 5.243E-08 4.576E-08 4.371E-08 4.385E-08 6.922E-08 9.576E-08 1.100E-07

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-117Table 2.3-38f CGS Calculation, Terrain Features, Desert Sigmas CGS REACTOR BLDG, SPECIFIC POINTS OF INTEREST RELEASE ID TYPE OF LOCATION DIRECTION FROM SITE DISTANCE X/Q X/Q X/Q D/Q (MILES) (METERS) (SEC/CUB.METER) NO DECAY UNDEPLETED (SEC/CUB.METER) 2.260 DAY DECAY UNDEPLETED (SEC/CUB.METER) 8.000 DAY DECAY DEPLETED (PER SQ.METER) B B B

B B

B B

B B

B B

B B

B B

B B

B B

B B

B B

B B B B B

B B

B B

B B

B B

B B

B B PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

EAB (1950 M) EAB (1950 M) EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M) SE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE SE SE ESE ENE NNE ESE SE SE NE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 6.40 3.90 4.00 4.10 4.20 4.30 4.40 4.50 3.00 3.10 3.21 3.30 3.40 3.50 3.60 15.00 4.80 4.20 4.10 4.30 0.10 9.59 8.29 4.30 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 10298. 6275.

6436.

6597.

6758.

6919.

7080.

7241.

4827.

4988.

5159.

5310.

5471.

5632.

5792. 24135. 7723.

6758.

6597.

6918. 160. 15437.

13346. 6919.

1950. 1950. 1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950. 3.7E-07 1.7E-06 1.7E-06 1.6E-06 1.5E-06 1.5E-06 1.4E-06 1.4E-06 1.0E-06 1.2E-06 1.5E-06 1.8E-06 1.9E-06 1.8E-06 1.8E-06 3.5E-07 5.7E-07 1.5E-06 9.8E-07 4.1E-08 3.1E-06 2.1E-07 2.6E-07 6.8E-08 1.9E-07 1.2E-07 7.9E-08 3.8E-08 3.8E-08 7.2E-08 1.1E-07 2.3E-07 2.6E-07 2.2E-07 1.6E-07 2.7E-07 2.9E-07 4.4E-07 2.7E-07 2.4E-07 3.5E-07 1.6E-06 1.6E-06 1.5E-06 1.5E-06 1.4E-06 1.3E-06 1.3E-06 9.9E-07 1.2E-06 1.5E-06 1.8E-06 1.8E-06 1.8E-06 1.7E-06 3.1E-07 5.5E-07 1.5E-06 9.3E-07 4.1E-08 3.1E-06 2.0E-07 2.5E-07 6.6E-08 1.9E-07 1.2E-07 7.9E-08 3.8E-08 3.7E-08 7.1E-08 1.1E-07 2.3E-07 2.6E-07 2.2E-07 1.6E-07 2.7E-07 2.9E-07 4.4E-07 2.7E-07 2.4E-07 3.4E-07 1.3E-06 1.3E-06 1.2E-06 1.2E-06 1.1E-06 1.1E-06 1.0E-06 8.1E-07 9.6E-07 1.2E-06 1.5E-06 1.5E-06 1.4E-06 1.4E-06 2.9E-07 5.5E-07 1.2E-06 7.7E-07 3.9E-08 3.1E-06 1.9E-07 2.4E-07 6.6E-08 1.8E-07 1.2E-07 7.6E-08 3.6E-08 3.7E-08 7.0E-08 1.1E-07 2.2E-07 2.5E-07 2.1E-07 1.5E-07 2.6E-07 2.9E-07 4.3E-07 2.6E-07 2.3E-07 3.2E-10 7.0E-10 6.6E-10 6.4E-10 6.0E-10 5.7E-10 5.5E-10 5.2E-10 1.2E-09 1.2E-09 1.1E-09 1.0E-09 9.4E-10 8.9E-10 8.3E-10 7.6E-11 5.9E-10 6.0E-10 3.8E-10 1.8E-10 4.0E-08 1.6E-10 2.0E-10 1.3E-10 1.6E-09 1.0E-09 5.7E-10 1.9E-10 2.4E-10 4.8E.10 9.0E-10 2.0E-09 2.8E-09 2.5E-09 1.8E-09 1.8E-09 1.5E-09 2.4E-09 2.0E-09 1.9E-09 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-118

TABLE 39 (a through f) DELETED COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-119 Table 2.3-40 Frequency of Wind Resuspension Periods at Hanford (1953-1970)

Total Dust Hours 476 Total Dust Days 142 Number of Dust Storms 150 Average Dust Hr/Yr. 26.4 Average Dust Days/Yr. 7.9 Average Dust Storms Per Year 8.3 Range in Duration of Dust Storms (hr.) 1-16 Average Duration of Dust Storms (hr.) 3.2 Average Dust Storm Concentration (from Table 2) mg/m3 6.77

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-120Table 2.3-41 Dust Concentration Dependency on Wind Speed and Direction at Hanford 1953-1970 Predicted Concentration From Visibility, mg/m3 WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 WIND SPEED CLASS (MPH) 55-63 64-UP OVERALL AVERAGE 25-31 32-38 39-46 47-54 SE SSE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE .00 .00 .00

.00 .00 .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 .00 .00 1.74 .00 3.29 2.02 3.29 1.74 4.38 .00

.00 2.71 .00

.00 7.83 .00 2.71 1.74 1.74 3.49 1.88 2.60 2.92 3.38 4.60 .00 3.29 .00 .00 2.71 1.62 2.48 6.34 1.81 1.83 2.64 2.58 2.58 3.50 3.41 3.38 3.05 2.44 .00 .00 1.38 1.38 1.62 3.54 4.96 2.89 1.77 1.50 4.80 5.06 6.08 4.54 2.19 3.60 .00 .00 1.25 5.70 2.21 2.75 4.13 5.37 1.99 1.98 .00 12.99 7.04 2.81 .00 2.71 .00 .00

.00 15.92 3.86 8.83 12.95 2.71 3.29 2.23 .00

.00 7.83 .00

.00 .00 .00 .00 .00 .00 4.13 13.87 48.31 .00 4.13 .00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 .00 .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 988.88* .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 .00 .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 1.78 7.17 2.95 19.40 7.67 3.54 2.39 2.08 2.77 3.81 4.77 3.84 2.48 2.78 2.71 OVERALL** AVERAGE .00 2.84 3.00 3.15 4.15 3.71 8.57 22.22 .00 988.88 .00 6.77 .00 NO DATA *VISIBILITY 0 TO 1/16 MILE DUE TO ONE-HOUR DUSTSTORM **WEIGHTED AVERAGE BASED ON TABLE 2.3-42 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-121Table 2.3-42 Hours Satisfying Dust Storm Criteria at Hanford (1953-1970) Hours With (1) Visibility 7 Mile and Dust Reported or (2) Visibility 7 to 14 Miles, Windspeed 5.8 M/Sec: RH 70% Dust Assumed WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 WIND SPEED CLASS (MPH) 55-63 64-UP TOTAL HOURS 25-31 32-38 39-46 47-54 SE SSE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 1 0 1 2 1 1 2 0 0 1 0 0

1 0 1 1 1 5 6 8 12 3 3

0 1 0 0 1

3 4 3 7 3 5 4 6 34 31 19 3 6 0 0 1

1 3 13 17 5 11 3 2 10 23 15 6 2 0 0 1

3 11 24 39 7 6 5 2 1 7 5 0 1 0 0 0

3 13 26 13 1 1 2 0 0 1 0 0 0 0 0 0

0 2 6 4 0 1 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 11 33 74 81 18 29 21 18 58 66 44 9 10 1 TOTAL HOURS 0 9 42 129 112 110 60 13 0 1 0 476 Amendment 55May 2001Rainfall Intensity, Duration, and Frequency Based on the Period 1947-69 at Hanford010126.012.3-1FigureForm No. 960690Draw. No.Rev.8.06.04.02.01.00.80.60.40.20.10.080.060.040.02A25105B10050C2D1000500Return Period (Years)51015203040502345681012182460MinutesDurationHoursIntensity (Inches per Hour)To use this chart, select any desired rainfall intensity and duration and read from the diagonal lines the expected frequency of such intensity and duration. For example, rainfall intensity of 1.3 inches per hour for 10 minutes can be expected to occur, on average, once every five years (point A). However, such intensity can be expected for 30 minutes duration only about once in 100 years (point B). The return period for intensity for 60 minutes duration is greater than 1000 years (point C).There are, of course, variations in use of the chart. Suppose, for example, it is desired to find the "100-year storm" for 60 minutes. This is 0.8 inch (point D).250Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Greatest Depth of Snow on Ground During 24 of 25Winters of Record at Hanford (1946-47 through1969-70)990306.142.3-2FigureForm No. 960690Draw. No.Rev.1008060402010864210.010.10.52510203040506070809095989999.999.99PROBABILITY (%) THAT GREATEST DEPTH WILL EXCEED GIVEN AMOUNTPROBABILITY (%) THAT GREATEST DEPTH WILL NOT EXCEED GIVEN AMOUNT99.9999.999.899959080706050403020105210.50.20.10.050.01INCHES1964-65*GREATEST DEPTH WAS LESS THAN 1 INCH DURING ONE WINTER (1957-58)98Columbia Generating StationFinal Safety Analysis Report

Amendment 55May 2001Peak Wind Gust Return Probability Diagram990306.172.3-4FigureForm No. 960690Draw. No.Rev.100AVERAGE NUMBER OF YEARS BETWEEN OCCURRENCE OF A GIVENSPEED AND THAT OF AN EQUAL OR GREATER SPEEDSPEED (MPH)1.00011.0011.0101.101.201.301.401.601.802.003.04.06.08.0 10203040 50608010020030040060080010002000300040008000Y = REDUCED VARIATEEXTREME PROBABILITY PAPERRETURN PERIOD = T908070 60 5040-2-10 1

234 5

6 7

8OBSERVED VARIATE = XJUNE 1957JUNE 1957JANUARY 1972MODEMEANColumbia Generating StationFinal Safety Analysis Report400 FT LEVEL200 FT LEVEL50 FT LEVEL Amendment 55May 2001Dust Occurrences Per Wind Speeds to 400 ftHeights990306.182.3-5FigureForm No. 960690Draw. No.Rev.400300 200100001020304050607080HEIGHT ABOVE GROUND (FT)()()(a) AVERAGE MASS OF DUST PER FOOT3, AND(b) MASS MEAN DIAMETER OF DUST PARTICLES. METEOROLOGY TOWER, HAPO. AUGUST 11, 1955(a) MASS PER CUBIC FOOT (x 10-3 GM/ft3)(b) MASS MEAN DIAMETER ()Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Near-Surface Airborne Dust Concentration as aFunction of Average Air Velocity990306.192.3-6FigureForm No. 960690Draw. No.Rev.3001001010369121518212427301950 DATADUST @ 4 FT.

WIND @ 1.5 METERS3AIR VELOCITY (MPH)DUST @ 8" WIND @ 7 FT.1/11/72 DUST STORMAIRBORNE DUST CONCENTRATION, mg/m3Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001D.P.Monthly Hourly Average of Temperature andRelative Humidity - January thru April990306.212.3-7.1FigureForm No. 960690Draw. No.Rev.JanuaryPST0204060810121416182022249080 70 60 504030 20 10PSTF and %02040608101214161820222490 80 70 60 504030 20 10FebruaryTemp. (D.B.)R.H.MarchPSTTemp. (D.B.)W.B.020406081012141618202224908070 60 50 403020 10R.H.PSTF and %F and %F and %020406081012141618202224908070 60 50 403020 10AprilTemp. (D.B.)D.P.R.H.W.B.W.B.D.P.D.P.Temp. (D.B.)W.B.R.H.Monthly and annual hourly averages of Dry Bulb (D.B.) and Wet Bulb (W.B.)Temperature Relative Humidity (R.H.) and temperature of the dew point (D.P.)(1957 - 1970)Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Monthly Hourly Average of Temperature andRelative Humidity - May thru August990306.402.3-7.2FigureForm No. 960690Draw. No.Rev.MayPSTTemp. (D.B.)W.B.D.P.0204060810121416182022249080 70 60 504030 20 10R.H.PSTF and %0204060810121416182022249080 70 60 504030 20 10JuneTemp. (D.B.)R.H.JulyPSTTemp. (D.B.)W.B.D.P.020406081012141618202224908070 60 50 403020 10R.H.PSTF and %F and %F and %020406081012141618202224908070 60 50 403020 10AugustTemp. (D.B.)D.P.R.H.W.B.W.B.D.P.Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Monthly Hourly Average of Temperature andRelative Humidity - September thru December990306.222.3-7.3FigureForm No. 960690Draw. No.Rev.Monthly and annual hourly averages of Dry Bulb (D.B.) and Wet Bulb (W.B.) TemperatureRelative Humidity (R.H.) and temperature of the dew point (D.P.)(1957-1970)SeptemberPSTTemp. (D.B.)W.B.D.P.0204060810121416182022249080 70 60 504030 20 10R.H.PSTF and %0204060810121416182022249080 70 60 504030 20 10OctoberTemp. (D.B.)R.H.NovemberPSTTemp. (D.B.)W.B.D.P.020406081012141618202224908070 60 50 403020 10R.H.PSTF and %F and %F and %020406081012141618202224908070 60 50 403020 10DecemberTemp. (D.B.)D.P.R.H.W.B.W.B.D.P.Columbia Generating StationFinal Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.032.3-8.1FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.112510203040506070809095989999.999.99N(Hours)PercentAn inversion runof N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 dataJan-Feb14Columbia Generating Station Final Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.022.3-8.2FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.112510203040506070809095989999.999.99N(Hours)PercentAn inversion runof N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 dataMarch-AprilMay-June108Columbia Generating StationFinal Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.042.3-8.3FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.512510203040506070809095989999.999.99N(Hours)PercentAn inversion runof N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 dataJuly-Aug118Sept-OctColumbia Generating Station Final Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.052.3-8.4FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.512510203040506070809095989999.999.99N(Hours)Percent15Nov-DecColumbia Generating StationFinal Safety Analysis ReportAn inversion run of N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 data Amendment 55May 2001Topographic Cross Sections of RegionSurrounding Site990306.232.3-9FigureForm No. 960690Draw. No.Rev.600400MSL FT.600400600400600400800600400800600400800600400800MSL FT.MSL FT.MSL FT.SSWSWWSWW WNW NW NNWNorthNNENEENEE ESE SE SSESOUTH1086420246810km(6.2 mi.)Plant Site600400Plant SiteColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Yearly Hourly Average of Temperature andRelative Humidity990306.242.3-10FigureForm No. 960690Draw. No.Rev.Monthly and annual hourly averages of Dry Bulb (D.B.) and Wet Bulb (W.B.) TemperatureRelative Humidity (R.H.) and temperature of the dew point (D.P.)(1957-1970)AnnualPSTF and %Temp. (D.B.)W.B.D.P.02040608101214161820222490807060504030 2010R.H.Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Hourly Centerline( /Q at Site Boundary Circular Distance of 1.212Miles From Source (April 1974-March 1975)990306.252.3-11FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than)Wake FactorNo Wake FactorColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Hourly Centerline( /Q at Site Boundary Circular Distance of 1.212Miles From Source (April 1975-March 1976)990306.262.3-12FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than)Wake FactorNo Wake FactorColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Occurrence of (/Q for PostulatedAccidents of 8, 16, 72, and 624 Hr at Outer Boundary of LowPopulation Zone (3.0 Miles from Source) (April 1974-March 1975)990306.272.3-13FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than).624 Hours72 Hours8 Hours (Wake Factor)8 Hours (No Wake Factor)16 HoursColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Occurrence of ( /Q for PostulatedAccidents of 8, 16, 72, and 624 Hr at Outer Boundary of LowPopulation Zone (3.0 Miles from Source) (April 1975-March 1976)990306.282.3-14FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than)624 Hours72 Hours8 Hours (Wake Factor)8 Hours (No Wake Factor)16 HoursColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Annual Average /Q by Sector at the SiteBoundary for First and Second Annual Cycle Data990306.292.3-15FigureForm No. 960690Draw. No.Rev.10-5NNNENEENEEESESESSESSSWSWWSWWWNWNWNNW10-610-710-8Down Wind Sector(Solid Line is for 4/74 - 3/75 data;dashed line is for 4/75 - 3/76 data)No Building Wake FactorBuilding Wake Factor IncludedColumbia Generating StationFinal Safety Analysis Report CHI/Q (sec/m3)

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.4-1 2.4 HYDROLOGY ENGINEERING The italicized information is historical and was provided to support the application for an operating license.

2.4.1 HYDROLOGIC DESCRIPTION

2.4.1.1 Site and Facilities Columbia Generating Station (CGS) is located in the Hanford Site within Benton County, Washington, approximately 3 miles west of the Columbia River at river mile (RM) 352, 10 miles north of Richland and 45 miles downstream from Grant County PUD Priest Rapids Dam. The site coordinates are approximately 46° 28' North Latitude and 119° 20' West Longitude. The Columbia River is the predominant hydrologic feature of the area and provides principal drainage for the surrounding area. The riverbed is clearly marked in the terrain and at the proximity of the site the river flows between high banks. The Columbia River approximate riverbed elevation is 328 ft above mean sea level (msl); the ground elevation at the site is approximately 440 ft. Another hydrologic feature of the area is the Yakima River, which at its closest approach flows within 8 miles of the plant site. The river system is shown in the hydrographic map, Figure 2.4-1. Figures 2.1-1 and 2.1-2 show the major hydrologic features of the area.

All Seismic Category I structures are located above maximum postulated flood elevations. For flood elevations refer to Sections 2.4.3 and 2.4.4.

Water for cooling tower makeup water and other plant requirements is withdrawn from the Columbia River. The intake system is designed for a maximum capacity of 25,000 gpm (55.7 cfs). The non-safety-related makeup water intake system is approximately 3 miles east of the plant and is made up of two offshore perforated pipe inlets, two lead-in pipes, and pump house structure.

A topographic map and contour map of the region surrounding the site are shown in Figures 2.4-2 and 2.4-3. The natural drainage features of the surrounding area have not been changed by the construction of CGS.

2.4.1.2 Hydrosphere The Columbia River, the largest river flowing into the Pacific Ocean from North America, is one of this world's greatest sources of hydroelectric power. Its annual discharge of 18,000,000 acre ft (1 acre-ft = 43,560 ft3) is exceeded in the North American continent only by the Mississippi, Mackenzie and St. Lawrence Rivers.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-2 The Columbia River drains an area of approximately 258,000 square miles, lying to the west of the Continental Divide in the northwestern part of the U.S. (85%) and southwestern part of Canada (15%). Major tributaries are the Kootenay, Snake, Pend Oreille, Spokane, Okanogan, Yakima, and Willamette Rivers. In determining the Standard Project Flood (SPF) the drainage area was divided into subbasins. These subbasins can be grouped into six general areas with similar hydrometeorological characteristics.

The six areas are: (1) upper Columbia, which includes the drainage of the area in Canada and the northern part of the United States above Chief Joseph Dam; (2) Middle Columbia, which includes the area between Pasco and Chief Joseph Dam; (3) Upper and Middle Snake River; (4) Lower Snake River, the area between Weiser and Ice Harbor Dam; (5) Lower Columbia, including the area between Bonneville Dam and Pasco; (6) the Columbia below Bonneville Dam, including the Willamette River.

The river basin has five outstanding physical features: the Rocky Mountain System, the Columbia Plateau, the Columbia River Gorge, the Cascade Range and Puget Trough.

The Rocky Mountain System is the major range with elevations from 2000 to over 12,000 ft. There are permanent glaciers and extensive snow fields at higher elevations and deep valleys that provide the principal drainage for the head-waters of the Columbia, Kootenay and other rivers.

The Columbia Plateau is a great, generally treeless, semiarid plateau covering over 100,000 square miles in the central portion of the basin. This plateau is in an area between the Cascade Range and the Rocky Mountains. The plateau was formed by successive flows of lava and filled to a general thickness of approximately 4000 ft. The Columbia River flows 1214 miles from its source in Columbia Lake (el. 2700 ft) in British Columbia, near the crest of the Rockies, to the Pacific Ocean at Astoria, Oregon. It sweeps around the north and northwesterly sides of the Columbia Plateau to central Washington to be joined by the Snake River. The Columbia River flows directly across the axis of the Cascades in a narrow gorge to the Pacific.

The Columbia Gorge is the gateway from the Pacific Ocean to the intermountain Columbia Plateau. Tide flows 140 miles up-river. For most of its length the river flows in deep valleys and canyons.

High flows occur in late spring and early summer with melting of snow on the mountainous watershed. Low flows occur in autumn and winter.

The Columbia River has been regulated by dams and reservoirs over the past 35 years. A large portion of the main stream and major tributaries is developed to meet various COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.4-3 functional requirements, such as flood control, hydroelectric power, irrigation, municipal and industrial supply, etc. The regulation of Columbia River floods is accomplished by use of reservoir storage space provided primarily for irrigation or for hydroelectric power utilization. The volume of usable reservoir storage space is on the order of 20% to 25%.

There are seven dams upstream and four dams downstream of the site on the main stream of the Columbia River within the U.S. These dams are listed in Table 2.4-1. The Columbia River flow in the reach of CGS is controlled by regulation of the upstream reservoir projects, which have a total usable storage capacity of approximately 35 million acre-ft. Some control of flow in the immediate vicinity of the site is by regulation of the nearest upstream hydroelectric projects, Priest Rapids Dam, at RM 397, containing about 45,000 acre-ft of active storage, and Wanapum Dam, at RM 415, containing about 161,000 acre-ft of active storage. Some minimal effect on the river flow in the vicinity of the site is caused by McNary Dam, at RM 292, approximately 60 RM downstream from the site area.

Flows in the Columbia River during the summer, fall, and winter vary from a low of 36,000 ft3/sec to as much as 160,000 ft3/sec. During spring runoff high flows ranging from 250,000 ft3/sec to 450,000 ft3/sec have been recorded. The average annual flow is 120,000 ft3/sec; during low flow periods flows may average about 60,000 ft3/sec (see Figure 2.4-4).

The Grand Coulee and Bonneville dams were put into operation prior to World War II and several dams were built after the war. The four downstream dams include large locks to permit the passage of river vessels. Several of the dams provide emergency floodwater storage. Grand Coulee, the largest and most complex of the dams, augments the low winter flows for the entire system from its 9,402,000 acre-ft of available storage (of which approximately 5,100,000 acre-ft is active storage) and also pumps water to the Columbia River Irrigation Project.

The river channel near the CGS site varies between 400 and 600 yards in width for low water and normal high water level, respectively. The depth varies from about 25 ft to 45 ft for normal high water and flood high water levels, respectively. Velocities vary from 3 ft/sec to over 11 ft/sec depending on section and flow. Average water temperature is 51°F. Temperatures may reach a low of 32°F and a high of 68°F. (See Table 2.4-2 and Figure 2.4-4.)

A list of water usage downstream of CGS, obtained from records of the Department of Ecology, State of Washington, for water rights as of February 1980, is presented in Table 2.4-3. The closest municipal surface water user is the City of Richland with an intake approximately 12 miles downstream. The location of local groundwater users is discussed in Section 2.4.13.2.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.4-4 2.4.2 FLOODS

2.4.2.1 Flood History Floods in the Columbia River Basin are grouped as: a. The interior basin east of the Cascades, caused by melting snowpack and occurring from May through June; b. The Willamette and other basins, west of the Cascades, caused by direct runoff from intense winter rain occasionally augmented by snowmelt. There is some overlapping effect within these two groupings. At certain elevations, basins in the interior Columbia drainage area occasionally have significant flood flows resulting from winter rain or snowmelt. These are local floods and do not usually contribute sufficient flow to cause flooding of the main Columbia River. Major floods in the Columbia River Basin result from rapid spring melting of the snowpack over a wide area, generally augmented by rain or by above-normal precipitation in May, accompanied by a major chinook wind which causes rapid area temperature rise. The annual spring snowmelt flood of the main interior basin is characterized by relatively uniform distribution over the basin. The snowfall and individual snow storms may vary, but the integration of all storms over the winter period smoothes the irregularities, with the result that the distribution of the flood runoff is reasonably constant from year to year.

The maximum historical flood of record is that of June 7, 1894, which resulted from a combination of hydrometeorologic conditions, including heavy snowpack and rapid melt plus rainfall. The peak discharge at CGS was 740,000 ft3/sec for the Columbia River, as estimated from high water marks at Wenatchee, Washington (Reference 2.4-1). The largest recent flood, occurring in 1948, had an observed peak discharge of 690,000 ft3/sec at Hanford. These floods were spring floods resulting from the melt of a large snowpack combined with the spring rains (Reference 2.4-2). Water surface profiles for the Columbia River in the vicinity of the site as derived by the Corps of Engineers (Reference 2.4-2) are given in Figure 2.4-5.

The plant site is located approximately three miles west of the Columbia River at RM 352 with reactor floor elevation of 441 ft msl, which is 68 ft above the water level estimated for the largest historical flood (approximately 373 ft msl). There is no record of flooding in the immediate site area.

2.4.2.2 Flood Design Considerations Flood protection of safety-related components is based on the highest calculated flood water level including wave effects, resulting from intense local precipitation. Several different probable maximum events were considered, including the Corps of Engineers design-project COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 LDCN-03-069 2.4-5 flood considered to be "the most severe reasonably possible." Wave action caused by storm winds, the effects of failure of upstream dam surge flooding, and ice flooding were also considered.

The results of these analyses (described in Section 2.4.3) indicate that the CGS site is safe from floods and that no flood protection measures are required. The Hydrogen Storage and Supply Facility located 0.6 miles south-southeast of the plant is subject to flooding due to the PMP flood discussed in Section 2.4.3.1. Equipment storing liquid and gaseous hydrogen has been analyzed for the effects of this flood (Section 2.4.2.3). As discussed in sections that follow, plant safety-related structures are located above high water elevations associated with Columbia River flooding (Sections 2.4.2.1 and 2.4.3), intense local precipitation (Sections 2.4.3.5 and 2.4.3.6), and upriver dam failures (Section 2.4.4).

2.4.2.3 Effects of Local Intense Precipitation Intense local summer thunder storms can produce short duration rains which have the potential for causing serious flood. Winter precipitation may occur as rain or snow and would be less intense than the worst summer thunderstorm. The probable maximum precipitation (PMP) event for the CGS site has been determined using the methodology developed by the U.S. Weather Bureau and reported in Hydrometeorological Report No. 43, "Probable Maximum Precipitation, Northwest States" (Reference 2.4-3).

The plant area slopes easterly to a broad channel which is adequate to store and drain the PMP. Construction contours of the site are shown in Figure 2.4-28. The reactor building and the spray ponds are located at elevations that are safe from the effect of any flood resulting from the maximum precipitation event.

Winter precipitation may occur as rain or snow. The winter season snowfall has ranged from less than 0.5 in. to a maximum of 12 in. in December 1964. There is no ice accumulation at the site.

To accommodate surface drainage during severe climatic conditions such as rainfall and rapid snow melts, a system of catch basins and dry wells is provided with inlet elevations a minimum of 6 in. lower than the nearest road and a minimum of 12 in. lower than the finished floor elevation of the nearest building(s). Runoff from the PMP event is accommodated by designing the roadways such that the high point of the road is 6 in. to 1 ft below the finished floor elevation of the adjacent safety-related building(s). Runoff from this event is from the northwest to the southeast across the site plateau to the low area southeast of the plant site. The general plant site is nominally 9 ft above the maximum calculated water surface elevation resulting from the postulated PMP (Section 2.4.3.3). Therefore, the site grading precludes the potential flooding of safety-related structures. The Hydrogen Storage and Supply Facility is subject to the PMP event flooding.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-13-050 2.4-6 The elevation of the facility is 420 ft msl and the PMP flood level is 431.1 ft msl (Section 2.4.3.5). See Section 10.4.10 for more discussion.

Roofs of buildings are designed to take, with adequate drainage, any instantaneous or local intense precipitation. Discharge from roof drains is carried by means of a storm sewer system to a manhole located southeast of the reactor building. From that point a pipeline with a northeast alignment transfers the discharge to lined evaporation ponds about 1500 ft away from the plant site.

The roofs of safety-related buildings (diesel generator building, radwaste/control building, standby service water pump house) are concrete beam and slab construction except the high roof of the reactor building, which is metal deck on steel framing. The minimum roof slope for all structures is 1/8 in. per ft for adequate drainage and the roof areas are encompassed by curbs or parapet walls up to 3 ft 6 in. high. Roof plans, including details of roof drains and overflow scuppers, are provided in Figure 2.4-6. Assuming that the roof drains are completely blocked during the PMP event, overflow scuppers limit the depth of water to within the design load carrying capability of the roofs. Those safety-related structures that do not have this relief capability structurally can carry the entire PMP accumulations. 2.4.3 PROBABLE MAXIMUM FLOOD ON STREAMS AND RIVERS Analyses for probable maximum flood (PMF) and SPF on the Columbia River (Reference 2.4-2) are consistent with the requirements of Regulatory Guide 1.59, Revision 2. The SPF for the Mid-Columbia Reach of the highly developed and regulated Columbia River is defined as 570,000 ft3/sec (Reference 2.4-4). The unregulated SPF for the same reach is 740,000 ft3/sec. The unregulated PMF at the site is estimated to be 1,600,000 ft3/sec (References 2.4-2, 2.4-4, and 2.4-5).

Adjustment of the flood profiles for the Hanford region reported in Reference 2.4-4, results in a regulated PMF of 1,440,000 ft3/sec and a water level of 390 ft at the Seismic Category II makeup water structure. This structure is not designed to function throughout the PMF but is designed for the SPF (unregulated) of 740,000 ft3/sec.

Although assumed to exist for the purpose of flood hydrograph calculations, Ben Franklin Dam is not a federally authorized project. As originally planned it would have been a low head dam with only a negligible effect on extreme flood flows (Reference 2.4-6). The design basis flood for the CGS site area results from the PMP event on the adjacent drainage basin and not from flooding of the Columbia River.

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-12-020 2.4-7 2.4.3.1 Probable Maximum Precipitation The PMP event which was presented in the CGS PSAR was subsequently reevaluated in the preparation of the PSAR for WPPSS Nuclear Project No. 1 (Docket 50-460). The analysis presented here is consistent with the latter document.

Precipitation in the vicinity of the site has been classified by the U.S. Weather Bureau, Reference 2.4-3, as convergence precipitation, orographic precipitation, and thunderstorm precipitation. The methodology for predicting the total amount of precipitation from each of these events, as given in Reference 2.4-3, requires the adding together of the convergence PMP and the orographic PMP to obtain a single precipitation for a general storm. A separate analysis is then required for thunderstorms. Thunderstorms in the vicinity of the site can be locally very intense for short periods of time and hence, have the potential for causing serious flooding. The PMP for both a general storm and a thunderstorm were analyzed as given in Chapters 6 and 5, respectively, of Reference 2.4-3 for a 38.5 mile2 basin at the site. This basin is shown in Figure 2.4-8 and is described in Section 2.4.3.3. The calculated general storm PMP results in a 24-hr and 48-hr precipitation of 7.9 in. and 10.1 in., respectively.

A thunderstorm PMP yields 9.2 in. in a 6-hr period. Therefore, the thunderstorm is considerably more severe. The thunderstorm PMP hydrograph is Time Rain (hr) (in.) 1 0.6 2 1.6 3 5.2 4 0.9 5 0.5 6 0.4 Total 9.2

2.4.3.2 Precipitation Losses Infiltration losses have been estimated in the vicinity of the sites as 1.5 in./hr (Reference 2.4-7). However, for the analysis below, an average antecedent moisture condition (Condition II as defined in Reference 2.4-8) was assumed. As explained in the following section, the 60-minute retention loss rate is 0.15 in./hr.

2.4.3.3 Runoff and Stream Course Models The drainage basin common to the reactor building and spray ponds is shown in Figure 2.4-8. The entire area drains to a broad channel that extends in a north-south direction for about 7 miles, and ranges from about 2000 ft to over a mile wide. All plant structures are located on COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-8 high ground to the west of the channel. At a point about 2.8 miles south of the reactor site, the four-lane Department of Energy (DOE) highway crosses the drainage basin. The area above this section is 33.2 miles2. To evaluate the effect of the PMP event on the plant area, the peak discharge at the highway crossing, 2.8 miles downstream of the plant, was calculated using the U.S. Bureau of Reclamation procedure for computing design floods on ungauged basins from thunderstorm rainfall in the western U.S. (Reference 2.4-8). Important assumptions used in the triangular hydrograph procedure of Reference 2.4-8 are a. Hydrologic soil group B,

b. Land use and treatment class - poor pasture or range,

c. Thunderstorm cover-index is brush-sage-grass combination with 50% or less cover density, and

d. Thunderstorm minimum 15-minute retention loss rate of 0.06 in./15 minutes and 60-minute retention loss rate of 0.15 in./hr.

Additionally, no credit was taken in the hydrograph analysis for potential storage in the stream channel or upstream sub-basins.

The time of concentration, Tc, for the watershed above the highway crossing was computed to be 7.5 hr. The PMF hydrograph is shown in Figure 2.4-7 for the 33.2 mile2 drainage basin. A peak discharge of 21,400 ft3/sec was determined.

Based on this PMF, an upstream water surface profile was determined using the Corps of Engineers HEC Standard-Step Procedure (Reference 2.4-9). A total of eleven cross sections were used (seven downstream, one at the plant, and three upstream as shown in Figure 2.4-3). Details of the channel cross sections are shown in Figure 2.4-9. The Manning roughness coefficient was conservatively taken as n=0.035 in the main channel sections, and n=0.05 in the overbank areas.

Using the computational procedure of Reference 2.4-9, it was determined that the channel restrictions at cross sections 5 and 7 (Figure 2.4-3) do not control the flow. The stillwater elevation at the plant site (cross section 8) was determined to be 431.1 ft msl. The water surface profile is shown in Figure 2.4-10.

2.4.3.4 Probable Maximum Flood Flow The PMF runoff hydrograph produced by the PMP at cross section 1 (Figure 2.4-3) is shown in Figure 2.4-7. The peak discharge at this location is 21,400 ft3/sec.

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-12-043 2.4-9 2.4.3.5 Water Level Determinations As discussed in Section 2.4.3.3, the water elevation of a flood at the plant site generated by the PMP event is 431.1 ft msl. This flood condition has a higher estimated elevation than any flood of the Columbia River.

2.4.3.6 Coincident Wind Wave Activity Procedures published by the Corps of Engineers (References 2.4-10 and 2.4-11 were used to determine the wind wave activity. The effective fetch for the predominant July wind direction (north) is 3450 ft (0.65 miles). The effective fetch diagram is shown in Figure 2.4-11. The calculated extreme 2-year over water wind for the north-to-south direction, based on area data, is 63.5 mph. This wind results in a maximum wave height of 4.0 ft, with the assumption of a water depth of 12 ft (the average depth in cross sections 8, 9, and 10). The other potential wind directions ENE and ESE were evaluated but found to be less severe. The wind setup has been computed to be 0.3 ft, and the maximum wave runup is 1.9 ft on a smooth, 1 on 8 slope of compacted naturally occurring sands and gravels. Therefore, the design water surface elevation is 433.3 ft msl. This is less than the east spray pond overflow weir at elevation of 434.5 ft msl.

2.4.4 POTENTIAL DAM FAILURES, SEISMICALLY INDUCED

Analyses of floods resulting from potential dam failures were investigated by the Corps of Engineers for the Columbia River. These studies are consistent with Regulatory Guide 1.59, Revision 2. The flood resulting from the breaching of Grand Coulee Dam is considered in lieu of a seismically induced flood.

In 1951, the Seattle District Corps of Engineers made a confidential study (now declassified) to determine artificial flood hydrographs and the flood profile in the Columbia River Valley resulting from breaching the Grand Coulee Dam by enemy attack. The studies covered a spectrum of conditions in terms of breach openings and hydrologic conditions that might prevail at the time of attack. A postulated seismic failure of Grand Coulee Dam could result in displacement of part of the structure, but it would still act as a restriction or weir and minimize the hydraulic failure. For this reason, the explosion-induced artificial flood represents an upper limit to seismically induced failures. The failure of Grand Coulee Dam would initiate a catastrophic flood, which would be augmented by the failure of the earth portions of downstream dams and subsequent release of the storage pools. Figure 2.4-5 shows water surface profiles for RM 323 to RM 358 for various river flows, including Artificial Flood No. 1. This flood provides a "limiting case" assessment of the conservatism of CGS elevation. This flood would have an outfall peak of 8,800,000 ft3/sec at Grand Coulee Dam at the moment of breaching and a peak discharge at RM 338 (Richland) of 4,800,000 ft3/sec.

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-10 A base flow of 50,000 ft3/sec was assumed above the mouth of the Snake for this flood (Reference 2.4-12). An arbitrarily assumed dramatic failure of Arrow and/or Mica Dams in Canada could result in greater releases of storage in terms of volume than that from the Grand Coulee Dam, but the effects of such postulated releases are mitigated by a combination of valley storage and critical (flow limiting) valley cross sections. The Corps of Engineers states (Reference 2.4-13) that the river channel restrictions at Trail, British Columbia, would restrict river flow to about 3.1 x 106 cfs, regardless of the postulated dam failure. A major failure upstream would result in this maximum flow for many days causing overtopping of Grand Coulee Dam. An analysis by the Bureau of Reclamation (Reference 2.4-14) concluded that overtopping which might result from the failure of upstream dams will not cause failure of either the Grand Coulee Dam or the Forebay Dam.

Various studies (References 2.4-12, 2.4-15, 2.4-16 and 2.4-17) made by the Corps of Engineers, and others, since 1951 have considered that breaching of Grand Coulee Dam would represent the worst catastrophic event for downstream Columbia River occupants. Although these studies bear no relationship to flooding from natural causes, they have been used as the basis for a very conservative, limiting case approach.

Figure 2.4-5 shows water surface profiles for RM 323 to RM 395 for artificial and real stage flows, one of which corresponds to Artificial Flood No. 1 noted earlier, which has been established (Reference 2.4-18) as conservative (limiting case) criteria for Columbia River flooding. Since the base flow used to develop these curves was 50,000 ft3/sec, an additional 570,000 ft3/sec is added to account for simultaneous occurrence of the regulated SPF.

2.4.4.1 Dam Failure Permutations The effect of potential dam failure on the water levels at the site is determined using the following assumptions:

a. The Columbia River is at flood stage, with a SPF (570,000 ft3/sec regulated);

b. The reservoirs in each storage pool are full; c. A massive hydraulic failure occurs at Grand Coulee Dam, releasing 8,800,000 ft3/sec; d. Following the above assumed failure, all downstream dams between CGS site and Grand Coulee Dam suffer some degree of failure and release their storage reservoirs to the flood. [The result of a stability analysis (Reference 2.4-15) showed that all mass concrete portions of the dams will resist sliding and overturning with the possible exception of part of Rock Island Dam.];

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-11 e. The explosion-induced failure of Grand Coulee Dam represents a more severe failure than any seismic event because of the failure mechanism;

f. Failure of Arrow and/or Mica Dam could result in greater release of storage volume than Grand Coulee Dam; however, the peak flow is limited to 3,100,000 ft3/sec due to channel restrictions at Trail, British Columbia; and

g. Overtopping of Grand Coulee Dam would occur with failure of Arrow and/or Mica Dams in Canada. The failure of Grand Coulee, as a result of overtopping, is not considered to be a credible event in view of its concrete construction and rock abutments.

2.4.4.2 Unsteady Flow Analysis of Potential Dam Failures The flood hydrographs developed by the Corps of Engineers are based on the results of extensive studies of the physical characteristics of the flood route (References 2.4-12 and 2.4-15). Subsequent studies made by the Corps of Engineers verify these results (Reference 2.4-17). Water levels following such a flood would depend on the status of reservoir storage upstream from Grand Coulee Dam but, without regulation of some dams, would approximate the natural seasonal flow conditions.

2.4.4.3 Water Level at Plant Site The water elevations associated with limiting case flood (LCF) levels are shown in Figure 2.4-5. RM 350 provides the control for backwater flow to the plant area which is sheltered by higher ground east of WNP-1 and WNP-4. Elevation at RM 350 (dam breach flood = 422 ft msl 4,800,000 ft3/sec plus SPF, 570,000 ft3/sec)

Allowance for simultaneous wind and wave action + 2 ft Elevation: 424 ft msl=LCF An adequate margin exists between the resultant flood elevation and the plant elevation of 441 ft msl.

2.4.5 PROBABLE MAXIMUM SURGE AND SEICHE FLOODING The location of the CGS site is not close to any water body which experiences seiche flooding. Thus the site is not vulnerable to such flooding.

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-12 2.4.6 PROBABLE MAXIMUM TSUNAMI FLOODING The location of the CGS site is in south-central Washington and it is not adjacent to any coastal area. It is not, therefore, vulnerable to tsunami flooding.

2.4.7 ICE EFFECTS Historically, the Columbia River has never experienced complete flow stoppage or significant flooding due to ice blockage. Periodic ice blocking has caused reduced flows and limited flooding for only relatively short periods of time. The most significant icing in recent recorded history occurred during the winter of 1936-37 prior to the construction of the upstream regulating dams. A relatively thick sheet of ice formed across the river. The minimum flow recorded near the Priest Rapids Dam site during this winter was 20,000 cfs. However, the ice forming on the river was caused primarily by the low flow rather than the reverse. The deltaic mouths of many of the tributaries to the Columbia River are frequently blocked by ice causing backup of flood waters. No instance of complete stoppage is known to have occurred.

Ice blockage is most likely to occur when water temperatures are already low, when flows are small, and when a significant cold spell occurs. With the completion of Grand Coulee and other dams on the Columbia River main stream, the seasonal temperature and flow cycles have drastically changed. These changes will further aid to reduce the intensity and timing of the conditions which may contribute to potential ice blockage and flooding situations. Also average river flow rates, during the winter months, have been increased significantly. The water temperatures have shown a shift in time such that the peak temperatures occur 30-45 days later than formerly. In addition, the low extreme temperatures measured have risen over the years.

The long term trends of temperatures in the Columbia River been studied (Reference 2.4-19) using a 37 year record of measured temperatures. The trends for the maximum, average and minimum temperatures are shown in Figure 2.4-12. The erection of dams on the upper Columbia River has caused the extreme high and low river temperatures measured at Rock Island Dam (Columbia RM 453, 101 miles above the CGS site) to converge toward the average. Winter water temperatures are considerably warmer and summer temperatures cooler with a slightly lowered average of less than 1°F occurring during the 37 years.

On the basis of these studies and the recorded observation of 25 years of operation of the Hanford plutonium production plants, it is concluded that the potential for ice blockage or the combination of blockage and flooding behind ice dams is so low as to be considered insignificant. The erection of Mica, Arrow, and Libby Dams in the Columbia River Basin headwaters is expected to further raise winter water flows and also to increase winter water temperatures somewhat.

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-13 In any event, ice flooding will not effect the capability to shut down the reactor in a safe and orderly manner. Also, the daily fluctuating stage of the river at the intake location will discourage formation of sheet ice as well as ice jams. Ice flows, should they occur, will normally pass over intake structure due to relatively high winter discharge in the river. 2.4.8 COOLING WATER CANALS AND RESERVOIRS

There are no cooling water canals. The two spray ponds located southeast of the reactor building designed as Seismic Category I structures, have reinforced concrete side walls, and reinforced concrete base mats at el. 420 ft msl. The finished grade at the spray ponds is approximately at el. 434 ft msl and have top of wall elevations of 435 ft msl. The spray ponds are the ultimate heat sink for normal reactor cooldown and for emergency cooling.

The spray ponds are a part of the standby service water system which is discussed in Section 9.2.7. See also Section 2.4.11.6.

During normal reactor operation, the cooling water necessary for the plant is supplied from the cooling tower basins.

2.4.9 CHANNEL DIVERSIONS

The Columbia River flow in the Hanford reach is controlled to a large extent by regulation of the upstream reservoir projects. The riverbed in the vicinity of the site is well defined and it is very unlikely that the riverbed would be diverted from its present location by natural causes. Any possible effect on water supply to the makeup water pump house from riverbed changes would come from extremely slow changes which can be corrected if and when they occur.

As discussed in Section 2.4.7, the river has not frozen over in Hanford reach during at least the past 25 years, and icing on the river has not been a problem at pump house or outfall structures associated with the plutonium production plants.

2.4.10 FLOODING PROTECTION REQUIREMENTS

The design considerations of safety-related facilities to withstand floods and flood waves are described in Section 2.4.2.2. The PMF is discussed in Section 2.4.3.

All safety-related facilities are housed in Seismic Category I structures protected from flooding and designed to withstand the static and dynamic forces of all postulated floods. Flood considerations are described in Section 3.4 and the design of Seismic Category I structures, for all conditions including flood, is described in Section 3.8.

In the event of a flood at the site, it will be possible to place the plant in a safe shutdown condition.

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-14 All non-safety-related facilities with the exception of the makeup water pump house, are above the LCF elevation. The flooding of the makeup water pump house would not affect safety-related equipment and would not affect the safe shutdown of the plant. The approximate finished grade at all Seismic Category I structures except the spray ponds is at elevation 440 ft msl. The finished grade of the spray ponds is 434 ft msl.

The PMF elevation of the Columbia River (described in Section 2.4.3), at the site, is estimated to be 390 ft msl. Seismic Category I structures are designed to withstand the static and dynamic forces which could result from a flood due to a breach of Grand Coulee Dam. Since this represents the LCF, the structures are also considered secure against the forces due to the lower PMF.

The access openings to all seismic Category I structures are located well above all flood water elevations, including that due to wind and wave action.

2.4.11 LOW WATER CONSIDERATIONS

As described in Section 2.4.1.1, plant water needs are supplied through an intake structure in the Columbia River. The top of the makeup water intake screens (at RM 352) are set below the water surface elevation that would be associated with the minimum allowable flow (36,000 cfs) at the federally licensed Priest Rapids Dam (at RM 397). Water levels at the CGS intake are not influenced by backwater from the downstream McNary Dam (RM 292). The Columbia River Basin upstream of CGS has in excess of 35 million acre-ft of usable reservoir storage capacity. Because of this storage and highly regulated river flows, it is improbable that flows below the licensed minimum will occur. Based on data for 1961 through 1994, 7-day low flow with a recurrence interval of 100 years has been estimated at 44,500 cfs.

Even if some event (e.g., very severe drought) caused the makeup water system to be inoperable, the loss of water would not compromise the safe shutdown of the plant. As is discussed in Sections 9.2.5 and 9.2.7, shutdown cooling water is supplied by the ultimate heat sink which contains a 30-day supply of water in two spray ponds. The only scenario in which the makeup water pump house is called on to supply water in an emergency situation is when a tornado removes a significant quantity of spray pond water (see Section 9.2.5.3). Therefore, the low river water condition is not a situation requiring safety-related features and procedures.

2.4.11.1 Low Flow in Streams Reservoir projects on the Columbia River Basin upstream of the proposed site have a total usable storage capacity in excess of 35 million acre-ft. This capacity is sufficient to maintain a flow in the Columbia River, at the proximity of CGS, of 36,000 ft3/sec for over 1 year with absolutely no inflow from other sources. Because of this regulation, the anticipated minimum COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-15 and maximum monthly mean flow rates will be 60,000 and 260,000 ft3/sec in the vicinity of the site. It is improbable that minimum flows below that administratively set for dam operation (36,000 ft3/sec) will occur due to drought conditions. Columbia River storage measurements have been extrapolated down to 25,000 cfs and are shown in Figure 2.4-13. The river elevation at RM 352, site of the CGS makeup water pump house, is 341.73 ft msl and has a corresponding flow of 36,000 ft3/sec. 2.4.11.2 Low Water Resulting From Surges, Seiches, or Tsunami There exists no possibility of low water conditions resulting from meteorological or geoseismic generated surges, seiches, or tsunami unless such natural phenomena effected rapid closure of the Priest Rapids Dam, which is located 45 miles upstream from the proposed site. Rapid closure of the dam would cause a negative surge to be generated downstream. A complete stoppage of flow is an unlikely event because of the redundant equipment and operational procedure in place at the dam. Provisions to guard against an accidental shut off of Priest Rapids Dam include:

a. A gate actuation button in the control room of the Dam which is used to maintain at least minimum licensed flow from the facility in the event of one or more turbine shutdowns.

b. Independent motors on each gate which have redundant wiring and power supplies.

c. Electrical heating on four of the gates to prevent ice buildup which might interfere with gate operation.

d. Multiple offsite power sources in addition to an on-site diesel generator power backup for gate operation.

In the event of a rapid and complete stoppage of flow over Priest Rapids Dam the effect of the negative surge would pass the site in a few hours. Since the Priest Rapids Dam is a run of the river dam with low storage capacity, it is unlikely that its closure can restrict the Columbia River flow for a significant period of time before being topped.

2.4.11.3 Historical Low Water Historical records of the U.S. Geological Survey gauging station (RM 394.5) located 2.6 miles downstream from Priest Rapids Dam show low daily averaged flows of 20,000 ft3/sec (January 31, 1937) and low monthly averaged flows of 20,900 ft3/sec (February 1937). An instantaneous low flow of 4120 ft3/sec occurred February 10, 1932, due to activities connected with dam regulation of the river near Wenatchee, Washington, before construction of Priest COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-16 Rapids Dam. After completion of the Dam in 1956, the minimum flow rate of the Columbia River at RM 352, approximate location of the CGS makeup water pump house site, is 36,000 ft3/sec. The flow is maintained by the Grant County PUD as operator of the Priest Rapids Dam (RM 397) under FPC license which states: "The licenses shall so regulate the flow from the Project 2114 that it will not result in flows of less than 36,000 cfs of water at the Hanford Works of the Atomic Energy Commission except when conditions are beyond the licensee's control."

In eighteen years of operation the flow has not dropped below the specified minimum.

The annual average flow of the Columbia River below Priest Rapids Dam is in the range of 115,000 cfs. The effect of use of upstream water for irrigation development on the stream flow has been taken into account and the modified mean monthly discharge variations for the period 1928-58 are shown in Table 2.4-4 and Figure 2.4-14. The discharge for the base period of 1929-58 was adjusted to reflect 1970 levels of water utilization, including water consumption due to activities of flood control, power generation and irrigation. Figure 2.4-15 shows the exceedance frequency for annual low flows for the period 1929 through 1958 with 1970 conditions measured at the gauging station (RM 394.5) immediately below Priest Rapids Dam. Because of the flow regulation on the Columbia River, the anticipated minimum and maximum monthly mean flow rates will approximate 60,000 and 260,000 cfs in the vicinity of the CGS site. The variations of the river flow in this reach are due not only to seasonal fluctuations, but also to the daily regulation of the power producing Priest Rapids Dam. Flow rates during the late summer, fall and winter may vary from a low of 36,000 cfs to 160,000 cfs each day.

The dependable yield for flows in the Columbia River below Priest Rapids Dam for periods of one year through 10 years, as well as the 30-year period 1929-58 is illustrated in Table 2.4-5. The flow duration curve resulting from a plot of Table 2.4-4 is shown by Figure 2.4-14 (Reference 2.4-20). This figure illustrates the percentage of time equaled or exceeded for different amounts of flows below Priest Rapids Dam on a monthly and on an annual basis.

2.4.11.4 Future Controls Flows in the Columbia River at Hanford are required to be maintained above 36,000 ft3/sec. This is the licensed minimum flow of Priest Rapids Dam and, as such, is a parameter closely monitored and controlled by the Grant County PUD. The State of Washington has administratively set higher average daily minimum flows (greater than 40,000 ft3/sec) and will attempt to have the FERC licenses for the dams modified to insure the minimums (Reference 2.4-21).

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 LDCN-04-052 2.4-17 2.4.11.5 Plant Requirements All cooling water is supplied to the plant cooling towers via the circulating water system, the plant service water system, or the standby service water system described in Sections 9.2.1.2 and 10.4.5. In the event of an incident rendering the cooling towers inoperative, cooling water is supplied from the spray ponds by the standby service water system, described in Section 9.2.7. These are closed loop systems and the only water loss is through evaporative cooling.

Makeup to the plant cooling towers and spray ponds comes from the Columbia River. Should this capability be lost, the cooling load is taken over by the spray ponds. These ponds have sufficient capacity to provide shutdown cooling water for 30 days without makeup. Other sources of water are available to provide makeup after the initial 30-day period (see Section 9.2.5). Therefore, variation in river flow will not have any adverse affect on the capability to shut down the reactor in a safe and orderly manner.

2.4.11.6 Heat Sink Dependability Requirements At the minimum river flow of 36,000 ft3/sec described in Section 2.4.11.3, there is still sufficient submergence at the makeup water pumps to provide full makeup water requirements at full power operation. Sump level indication and low level alarms are provided in the main control room. Should the sump water elevation fall below the minimum submergence level for the makeup pumps, due either to low river flow or blocked inlets, the plant would be shut down if the situation could not be readily corrected with the safety-related standby service water coming from the spray ponds.

Section 9.2.5 discusses the design bases used in designing the two spray ponds which serve as the ultimate heat sink for CGS. Design of the CGS ultimate heat sink is in compliance with the guidelines presented in Regulatory Guide 1.27 Rev. 1, "Ultimate Heat Sink for Nuclear Power Plants," dated March 1974. The CGS spray ponds serve as the suction source and discharge point for the standby service water system. This system is discussed in Section 9.2.7 and identifies the uses and quantities of water drawn from the ultimate heat sink.

2.4.12 DISPERSION, DILUTION, AND TRAVEL TIMES OF ACCIDENTAL RELEASES OF LIQUID EFFLUENTS IN SURFACE WATERS Small amounts of liquid radioactive wastes, processed within the plant and containing traces of radioactive nuclides, are discharged ultimately to the Columbia River via the plant blowdown line as discussed in Section 11.2.2.2.6 (see Figure 2.4-16). In the vicinity of CGS, the Columbia River is wide, relatively shallow, and fast flowing. Field measurements have shown river velocities near the CGS discharge to be about 3 ft/sec for minimum flows (Reference 2.4-22) and 4.5 ft/sec for average flows (Reference 2.4-23). At the point of discharge the river is about 5 ft deep at minimum flow. Based on a dye dispersion study (Reference 2.4-22), the local eddy diffusivity at low flow has been conservatively estimated to COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-18 be 4 ft2/sec (Reference 2.4-24). With a combination of minimum river flow and maximum blowdown, it is estimated that an effluent would be diluted by a factor of about 60 at a distance of 300 ft and a factor of 200 at 3000 ft. Dilution factors and travel times for calculating doses to downstream water users are discussed in the CGS Offsite Dose Calculation Manual (ODCM).

Downstream surface water users are listed in Section 2.4.1.2. The travel time to the nearest withdrawal which could be affected by an accidental release is approximately 1 hr. At that point a radioactive release would be essentially completely mixed with the river resulting in a dilution factor of 1:200,000. It is concluded that water users are sufficiently removed from the release point, and the Columbia River is sufficiently dispersive to preclude adverse impacts due to accidental releases. The dispersion characteristics of the river and the effects of routine releases are discussed in Sections 5.1 and 5.2 of the Environmental Report - Operating License Stage.

2.4.13 GROUNDWATER

2.4.13.1 Description and Onsite Use Subsurface soil conditions, across the site, have been classified as follows: a. Loose to medium dense, fine to coarse sand with scattered gravel (glaciofluvial sediments).

b. Very dense, sandy gravel with interbedded sandy and silty layers (Ringold Formation, Middle Member).

c. Very dense, interbedded layers of sandy gravel silt and soft sandstone (Ringold Formation, Lower Member).

d. Basalt bedrock which forms the bedrock beneath the area.

The lithologic character and water bearing properties of the geologic units occurring in the Hanford region are summarized in Table 2.4-6. In general, groundwater in the surficial sediments occurs unconfined, although locally confined zones exist. Water in the basalt bedrock occurs mainly under confined conditions. Occasionally, the lower zone of the Ringold Formation occurs as a confined aquifer, separated from the overlying unconfined aquifer by thick clay beds which possess a distinct hydraulic potential.

The unconfined aquifer consists of both glaciofluvial sand and gravel deposits and the Ringold silts, clays, and gravels. Since these materials are very heterogeneous, often greater lithologic differences occur within a given bed than between beds. In the vicinity of CGS the water table is below the top of the Ringold Formation (see Figures 2.5-64 and 2.5-65). The unconfined COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-19 aquifer bottom is the basalt bedrock in some areas and silt/clay zones of the Ringold Formation in other areas. Clearly the bottom of the unconfined aquifer is not a continuous lithologic surface.

The Hanford Reservation contains over 2200 wells constructed from pre-Hanford work days to the present). Approximately 600 of these wells are used for groundwater monitoring (Reference 2.4-25). Figure 2.4-17 identifies the well locations in the Hanford Reservation as of September 1975. Figure 2.4-18 shows the December 1975 groundwater contour map. In general, the groundwater gradient resulting from groundwater flowing under the Reservation is the highest in the southwestern area toward Rattlesnake Mountain, and slopes toward the Hanford 200 Areas near the center of the reservation. From the 200 Areas the general slope in the gradient is toward northeast and southeast.

A groundwater contour map based on the potential construction of the Ben Franklin Dam at approximately RM 348 is illustrated by Figure 2.4-19. The CGS design basis groundwater level is based on the possible construction of the Ben Franklin Dam and is taken to be 420 ft msl, whereas the most recent study indicates that the water table would be about 405 ft msl (Reference 2.4-26). The feasibility of constructing Ben Franklin Hydroelectric Dam has been extensively studied. Its proposal was strongly contested by local groups and individuals concerned with environmental protection and preservation. Additionally, the matter of the impact such a facility would have on the DOE Hanford Reservation was believed by some to preclude its construction. Finally, the cost/benefit ratio was believed by many to be too low to make the project viable. The combination of the unresolved impediments to the project has effectively, though not conclusively, relegated it to a very low priority status. Planning studies for the project by the Corps of Engineers were suspended in 1969 and reinitiated in October 1979 as part of the development of a management plan for the Hanford reach. The most recent studies were terminated in November 1981.

Impermeable groundwater boundaries are the Rattlesnake Hills, Yakima Ridge, and Umtanum Ridge on the west and southwest sides of the Hanford Reservation. Gable Mountain and Gable Butte also impede the groundwater flow, as well as other small areas of basalt outcrop above the water table. The Yakima River recharges the unconfined aquifer along its reach from horn Rapids to Richland. The Columbia River forms a hydraulic potential boundary which is a discharge boundary for the aquifer. The major source of natural recharge is precipitation on Rattlesnake Hills, Yakima Ridge, and Umtanum Ridge.

Minor changes would be expected in the groundwater elevations during the summer months because of the charging stage of the Columbia River, which historically reaches peak flood stage in June. Because CGS is located about three miles from the river and because of the permeability characteristics and enormous volume of the Ringold Formation, there is a substantial time lag in changing water levels. For the same reasons, the range in water table fluctuations is very small.

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-20 Natural recharge due to precipitation over the lowlands of the Hanford Reservation is not measurable as the evaporation potential during the summer months greatly exceeds total precipitation. Data on migration of moisture from natural precipitation in deep soils (below 30 ft) show movement rates less than 1/2-in./yr at one measurement site (References 2.4-27, 2.4-28 and 2.4-29). The major artificial recharge of ground water to the unconfined aquifer occurs near the Hanford 200 East and 200 West Areas. The large volume of process water (1.35 x 1011 gal) discharged to ground during 1944-1973 has caused the formation of significant groundwater mounds in the water table (Figures 2.4-20 and 2.4-26). Other local groundwater mounds formerly existed along the Columbia River. The present Hanford 100-N Area mound is the only one of these remaining. A minor recharge mound also exists at the Hanford 300 Area.

The unconfined aquifer is characterized by its hydraulic conductivity, the storage coefficient, and the effective porosity. The hydraulic conductivity relates the water flow quantity to the hydraulic potential gradient, while the effective porosity gives the fraction of porous media volume that is available to transmit ground water flow. The storage coefficient relates a change in the water table elevation to a change in the volume of water contained in the aquifer per unit horizontal area. In the limit of no delayed yield, the storage coefficient is equal to the effective porosity of the soil through which the water table moves. These parameters vary widely over the Hanford Reservation.

Qualitatively the hydraulic conductivity, storage coefficient, and effective porosity distributions are a function of the different geologic formations in the unconfined aquifer. Ancestral Columbia River channels which incised in the Ringold Formation are now filled with more permeable glaciofluvial sediments. These channels have been identified extending eastward along the northern and southern flanks of Gable Mountain and extending southeastward from the 200 East Area to the Columbia River (see Figure 2.4-21). These permeable channels are reflected in the groundwater flow pattern of the region.

Quantitative measurements of the hydraulic conductivity of the unconfined aquifer have been made on the Hanford Reservation using a variety of techniques: pumping tests, specific capacity tests, and tracer tests. The most common method has been the pumping tests. Values obtained for the Ringold Formation range between 10 to 650 ft/day with a median of about 130 ft/day. In sharp contrast are the very large hydraulic conductivities of glaciofluvial sediments, ranging from 1,200 to 12,000 ft/day (Reference 2.4-30).

The storage coefficient is much more difficult to measure in the field and estimates are, therefore, less common. For the unconfined aquifer, estimates of the storage coefficient have ranged from 0.01 to 0.1 (Reference 2.4-30). An areal estimate of 0.11 has been provided for the 200 West Area based on the growth of groundwater mounds (References 2.4-30 and 2.4-31). The median specific yield (effective porosity) has been estimated by various researchers at Hanford to range from 4.8% to 11%; most commonly it is assumed to be 10%

(Reference 2.4-32).

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-21 The unconfined groundwater aquifer is characterized by the contour map of the hydraulic potential or water table. The map for December 1975 appears in Figure 2.4-18. The depth to the water table varies greatly from place to place, depending chiefly on local topography which ranges from less than 1 to more than 300 ft below the land surface. Beneath most of the Hanford 200 Area disposal sites the depth of the water table averages about 250 ft. The current estimate of the maximum saturated thickness of the unconfined aquifer is approximately 230 ft.

The chemical quality of the groundwater in the unconfined aquifer is measured at seven locations. Sodium, calcium, and sulfate ions are measured as well as pH. Chromium and fluoride ions associated with fuel manufacturing operations are analyzed from Hanford 300 Area wells. Nitrate ion, which is a waste product from the manufacturing and chemical separation operations, is monitored over the entire Hanford Reservation. Annual maps of the nitrate ion concentration near the surface of the unconfined aquifer are published (Reference 2.4-33). The map showing nitrate concentration for December 1975 appears in Figure 2.4-22.

The radiological status of the groundwater near the surface of the unconfined aquifer is monitored regularly (Reference 2.4-34) and reported annually. Plots of gross beta (ruthenium) plumes and the tritium plumes are shown in Figures 2.4-23 and 2.4-24 for December 1975 (Reference 2.4-33). Since the nitrate ion is not adsorbed in the soil it can be used as a tracer for groundwater movement. The extent of movement of waste water containing radionuclides can thus be plotted. Respective tritium and nitrate ion concentrations under the CGS site are currently ranging from 30 to 300 pci/ml and 4.5 to 45 mg/l depending on the sampling location. Concentration guide for drinking water is 3,000 pci/ml for tritium and the recommended drinking water standard is 10 mg/l for nitrate ions. Gross beta concentrations do not extend to the site.

From the research that has been done to date, it appears that there are a number of confined aquifers underlying the Hanford Reservation. Relatively impermeable confining beds commonly include the individual basalt flows and the silts and clays of the lower part of the Ringold Formation.

Within the basalt sequence, groundwater is transmitted primarily in the interflow zones, either in sedimentary beds or in the scoria and breccia zones forming the tops and bottoms of the flows (References 2.4-35 and 2.4-36). Basalt flows in the Pasco Basin have been eroded particularly in the anticlinal ridges. In some locations the basalts are highly jointed and contain breccia, pillow and plagonite complexes through which groundwater can move. Consequently, hydraulic potential differences between water bearing zones in the upper part of the basalt sequence are small over hundreds of feet of depth. The lowermost Ringold Formation silts and clays are of variable thickness. Distinct hydraulic potential differences have been observed between aquifers below the silts and clays and the unconfined aquifer.

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-22 Groundwater flow in the uppermost confined aquifer is also to the southeast with possible discharge into the Columbia River somewhere below Lake Wallula. However, the flow rates are regarded as quite small due to the low transmissivity range of this water bearing zone. Groundwater in the lower confined aquifers does not appear to cross the major anticlinal divides that define the Pasco Basin.

The piezometric or hydraulic potential map for the confined zones above the basalt (Figure 2.4-25) was based on measurements made in 1970. In general, the hydraulic potential observed in the confined aquifer zones above the basalt is greater than in the overlying unconfined aquifer. The main exception is in the vicinity of the Hanford 200 Area recharge mounds which have raised the potential in the unconfined aquifer.

One recharge area that has been identified is from the Yakima River at Horn Rapids. The piezometric map in Figure 2.4-25 also suggests recharge from the upper Cold Creek Valley with flow toward a potential trough under the Columbia River. The Columbia Basin Irrigation Project to the northeast and east, and the Columbia River behind Priest Rapids and Wanapum Dams to the northwest are other probable recharge sites in both these areas the basalt is exposed and is covered by perennially saturated unconsolidated deposits. A site of possible minor recharge exists adjacent to Gable Butte and Gable Mountain anticline near the center of the Reservation.

Only 90 wells on the Hanford Reservation have been drilled to basalt. Thus data on the confined aquifers in the basalt flows are limited and more would have to be gathered to fully characterize the confined aquifers.

The plant is located on glaciofluvial outwash sands and gravels which are about 50 ft thick. Below this layer occurs very dense gravel. Sandy gravel occurs in a sequence approximately 200 ft thick which is assumed to be the middle member of the Ringold Formation. The lower member of the Ringold Formation consists of a very compact, interbedded gravel, sand, silt, and clay and extends down to a depth of about 500-525 ft. Basaltic bedrock underlies the lower Ringold member, at approximately 550 ft depth.

The water table is about 60 ft below the ground surface level at CGS. The water table elevation is about 378 +4 ft msl and appears to be stable. The effective bottom of the unconfined aquifer is assumed to be at about 220-260 ft msl at the top of the lower Ringold Formation. Groundwater potentials from the lower Ringold and from the basalt water bearing zones are about 25 ft higher than that of the unconfined aquifer. Test borings down to 925 ft reveal there are water bearing zones in the lower basalt flows and sedimentary interbeds at CGS. Piezometric level in basalt is 10 ft above unconfined water table and hence artesian.

Under the CGS site the unconfined groundwater is moving easterly toward the Columbia River, the nearest discharge boundary. Studies of the uppermost confined aquifer indicate that the COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-23 potential gradients at the proposed site are oriented in the same general direct ion as those of the unconfined aquifer.

Three water supply wells are located on the site. Two shallow wells were constructed in the unconfined aquifer (at approximately 240 ft deep) and a third well penetrates a confined aquifer in the underlying basalt flows (at approximately 695 ft deep). Normal water supply is from the river, and the deep well is maintained in the standby mode to provide supplemental makeup water for the potable and demineralized water system as needed. Pumping capability is about 250 gpm. The two shallow wells were used during construction.

2.4.13.2 Sources Regional use of the unconfined aquifer occurs at two nearby locations. The first is at the DOE's 400 Area located about 3 miles southwest of the CGS site as shown in Figure 2.1-3. Groundwater to this construction site is supplied from two wells and is used for sanitary and operation purposes. Maximum expected usage rate is between 2 million and 2.5 million gal/month. No data is available on drawdown tests performed on the FFTF water supply wells 699-SO-7 and SO-8. The second location of ground water use is the WNP-1/4 site about 1 mile east of CGS. Water is drawn from two wells for sanitary and potable water requirements. Usage rate is approximately 250,000 gal/month.

The two onsite wells which drew from the unconfined aquifer (699-13-1A and 1B) are 234 and 244 ft deep. Drawdown tests for each well showed 22 and 91 ft of drawdown respectively, at pumping rates of 250 gpm and test durations of about 25 hr. These wells are no longer used. The third well (695 ft deep) is sealed from the unconfined aquifer and draws from confined water in the basalt. Drawdown on this well was 163 ft at a pumping rate of 275 gpm with a test duration of 25 hr.

Water table contours in the vicinity of CGS can be seen in Figure 2.4-26. The aquifer is assumed to be isotropic, therefore, flow occurs along instantaneous streamlines perpendicular to the equipotential contours. The groundwater flow is toward the discharge boundary at the Columbia River to the east of the site. The hydraulic potential gradient in this area is about 8-10 ft/mile in the unconfined aquifer. As described in Section 2.4.13.1, recharge and discharge of riverbank storage occur along the Columbia River with daily fluctuations superimposed on the seasonal variations in river stage. Hydrographs of wells in the vicinity of the plant site (Figure 2.4-27) show that riverbank storage is not detectable even in years of extreme spring runoff at the two wells that are about one mile from the riverbank. Thus no seasonal reversability of the gradients driving the groundwater flow occurs. In other areas of the Hanford Reservation, the seasonal fluctuations of groundwater levels from riverbank recharge can be detected 3-4 miles inland from the riverbank.

During early studies of groundwater in the area (References 2.4-37 and 2.4-31) little information was obtained on specific features at the plant site. The water table for 1944 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-24 (pre-Hanford Work conditions) was interpolated using 1948-1952 observation well data (Figure 2.4-20) and showed a water table elevation of about 370 ft msl under the site. The potential gradient was interpolated (References 2.4-31 and 2.4-38) to be about 5-6 ft per mile toward the Columbia River. The earliest wells in the vicinity (699-2-3 and 17-5) were drilled in 1950. Their hydrographs, presented in Figure 2.4-27, show the gradual rise of the water table to approximately 15 ft above pre-Hanford Operations elevations. The peak rise in 1972 for well 699-2-3 shown on Figure 2.4-27 is believed to be a measurement error. Other wells were drilled in 1958, 1961, 1962 and 1966. Their hydrographs appear in Figure 2.4-27. Wells 669-14-E6-T and E5T also show the gradual rise of the water table at their respective locations. Smaller apparent water table changes at the site between 1944- 1974 (see 2.4.13.1 and Figure 2.4-27, well 699-14-E6-T and 699-20-E5-T) indicated a zone of relatively lower hydraulic conductivity in this area.

Well 699-9-E2 is a deep well perforated in both the unconfined and lower confined aquifer zones. Its historical hydrograph (Figure 2.4-27) reflects a composite of confined and unconfined potentials with discontinuities caused by sanding in an subsequent maintenance operations. The 1962 peak of the hydrograph of well 699-20-E12 (Figure 2.4-27) is due to the influence of the high confined aquifer potential before the installation of piezometer tubes in this deep well. The 1972 peak, could be bank recharge from the high river stage of that year but the lack of previous response to river stage makes the measurement suspicious. Well 699-10-E12, also located within one mile of the river, does not show seasonal bank recharge (Figure 2.4-27). Over the past two years, a decrease in the rate of rise is evident.

Soil test borings and water supply wells drilled in conjunction with the CGS construction site, confirmed the present contouring interpretation of the water table. Recent data from boring at WNP-1 and WNP-4 are not reflected in the water table maps shown in Figures 2.4-18, 2.4-19, 2.4-26, and 2.4-25.

The historical well hydrographs for the uppermost confined aquifer in the vicinity of the plant site are given in Figure 2.4-27. Well number 699-20-E12-P shows a rather rapid rise of the confined aquifer potential in 1962-65. It has been postulated that this rise reflects recharge to the confined zones from irrigation across the river in the Columbia Basin Irrigation Project. The hydraulic potential in the uppermost confined aquifer near the plant site is presently about 390 ft msl, which is about 25 ft higher than the potential of the overlying unconfined aquifer.

The effects of the groundwater withdrawal at the site have been estimated to be local. No drawdown has been detected in the nearest observation wells, numbers 699-17-5 and 699-9-E2. The latter well is perforated over multiple aquifers so it does not give a representative measurement of the water table elevation. The radius of influence (defined to be the radius at which a 0.1 ft drawdown exists) of the CGS wells has been estimated to be about 3500-4500 ft. This is based on the ten months of high rate of withdrawal during compaction COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-25 operations taking into account the ambient water table gradient. The subsequent reduction in withdrawal flow rate to 25% of the early value would shrink the radius of influence considerably.

There is no groundwater recharge area within the influence of the plant. The 60-ft depth from the land surface to the water table and the arid condition of sediments above the water table make it virtually impossible to detect any recharge from precipitation over this area.

2.4.13.3 Accidental Effects An evaluation of a possible radioactive liquid release is postulated due to the rupture of a 700-gal decontamination solution concentrator waste tank within the radwaste building (see Figure 11.2-1). The released effluent was then assumed to reach the soil environment outside the building and to percolate to the water table unimpeded. On entering the groundwater, the postulated radwaste release is dispersed, sorbed, decayed, and diluted along the potential groundwater pathway from the plant towards the Columbia River.

In the unconfined (water table) aquifer, there are no down gradient groundwater users between CGS and the Columbia River. However, the construction water needs at WNP-1/4 are supplied by the two deep wells that withdraw groundwater from the uppermost confined aquifer downgradient from the CGS radwaste building. During operation of WNP-1/4, these wells will be maintained in a standby mode. The uppermost screens in these wells are about 240 ft below the ground surface in the lower Ringold Formation. The effective bottom of the unconfined aquifer is generally assumed to be at the top of the lower Ringold Formation or about 200 ft below the surface. Thus, in all likelihood, any liquid radioactive spill to the groundwater beneath the CGS radwaste building would travel through the unconfined aquifer towards the Columbia River. However, for conservatism, analyses of postulated radionuclide movement assume that the WNP-1/4 wells draw from the unconfined aquifer. The remainder of this subsection provides estimates of travel times of critical radionuclides to move from the postulated spill to receptors and the corresponding concentration reduction factors.

For an assumed one-dimensional groundwater movement, the groundwater travel time, t, is the path length, L, divided by the groundwater velocity (seepage velocity), u. The groundwater velocity is the Darcy (apparent) velocity divided by the effective porosity, u = Ki/ne, where K is the lateral permeability (hydraulic conductivity) of the aquifer, i is the hydraulic gradient, and ne is the effective porosity of the aquifer material.

For computational purposes, a conservative value for lateral permeability of 500 ft/day was selected to represent the unconfined aquifer located in the Ringold Formation beneath CGS (see Figure 2.4-21). From 2.4.13.1, effective porosity is taken 0.10. From Figure 2.4-26, the gradient in the water table aquifer between the plant and the Columbia River is about 8 or 9 ft/mile, and is taken conservatively as 10 ft/mile.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-26 Using the above parameter values, groundwater velocities were computed to be 10 ft/day. With path lengths of 3.4 miles to the river and 1.0 mile to the WNP-1/4 wells, the respective travel times are estimated to be 5.2 years and 1.5 years. Generally, the critical radionuclides of concern for a postulated liquid radwaste spill are 3H, 90Sr, and 137Cs. These three radionuclides are fairly representative in terms of sorption characteristics, of those found in liquid radwaste tanks, since tritium does not sorb onto soil particles at all, strontium is an intermediate sorber, and cesium strongly sorbs to soil particles. The half-life of tritium is 12.3 years, whereas those of 90Sr and 137Cs are 29.0 and 30.1 years, respectively.

The travel time, ti, for a particular radionuclide moving through groundwater depends upon the velocity, ui, of the radionuclide ti = l/ui where the radionuclide velocity is ui = rfu in which rf is the velocity reduction factor attributable to sorption r = 1/1+bn kfd In this equation, b is the bulk density of the aquifer material, n is the total porosity, and Kd is the equilibrium distribution coefficient for a particular radionuclide. The bulk density and total porosity are further related physically as b = Rs (1 - n) where Rs is the real specific gravity or particle density of the solid particles in the aquifer media. The particle density, Rs, for Hanford soils is usually taken to be constant at 2.65 gm/cm3, (Reference 2.4-39). The bulk density b, of Hanford soils has been determined to range from about 1.5 gm/cm3 to about 1.75 gm/cm3, with a median value of about 1.65 gm/cm3, (Reference 2.4-40). For the median value of bulk density, the corresponding total porosity is about 0.377.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-27 Using the above value for bulk density and total porosity, radionuclide travel time, ti, through the groundwater beneath WNP-1/4 can be expressed as ti = (1 + 4.4 Kd) t The following summarizes radionuclide travel times (in years) to the WNP-1/4 wells (1.0 miles) and to the Columbia River (3.4 miles):

Nuclide Half-life, years Kd ti @ 1.0 miles ti @ 3.4 miles 3H 12.3 0 1.5 5.2 90Sr 29.0 10 67.0 230.0 137Cs 30.1 100 660.0 2300.0 The radionuclide concentration at the point of water use will be determined by the amount of decay, dispersion, and sorption on the aquifer media. The minimum concentration reduction factor, CRFmin, along the centerline of the contaminant plume from an instantaneous point source is given by (Reference 2.4-41) CRF = CC (KKK)2Vminoxyz1/2()/432t for an effluent volume, V, with a specific gravity of 1.0 and an initial concentration, Co, released to soil with dispersion coefficients, Kx, Ky, Kz, in the x, y, and z directions, respectively. This expression neglects the phenomena of sorption and decay which will be considered later.

It is generally accepted that the dispersion coefficients are proportional to groundwater velocity for unidirectional flow, i.e.,

Kuxyzxyz,,,, = where x,y,z, are constants called dispersivities which are a function of the nonhomogeneity of the material. The range in dispersivities in homogeneous granular aquifers may approach 1000 cm (33 ft) (Reference 2.4-42). Substituting this relationship into the above expression for concentration reduction, and noting that travel time is determined by path length and velocity, results in CRFmin = (4L) ()2V3/2xyz1/2 For the conservative condition of x = y = z = 1.0, then COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-28 CRF = (4 L)2Vmin3/2 The concentration reduction factors at the WNP-1/4 wells and at the bank of the Columbia River, due only to dispersion, are 9.1 x 104 and 5.7 x 105, respectively, for the 700-gal concentrated waste tank. When sorption and decay are included, the concentration reduction is given by (Reference 2.4-42) CRF = (4 L)3 / 2 ( )xyz1/22V e ti in which is the radionuclide decay constant defined in terms of the half-life, T1/2, of a particular radionuclide as = 1n 2T1/2 The concentration reduction factor can be expressed as CRF = CRF (e t )min i The exponential term accounts for the effects of sorption and decay. The only effect of sorption on concentration reduction is to increase the travel time, thus allowing more time for decay. Concentration reduction factors (CRF) for the radionuclides listed were calculated for path lengths of 1.0 mile (to WNP-1/4 wells) and 3.4 miles (to Columbia River):

Nuclide CRF (1.0 mile) CRF (3.4 mile) 3H 1.0 x 105 7.7 x 105 90Sr 4.5 x 105 1.8 x 108 137Cs 3.7 x 1011 5.8 x 1928 The above factors, derived through the application of conservative parameters, are used in Section 15.7.3 to evaluate concentrations offsite. The consideration of the WNP-1/4 wells is especially conservative. Groundwater contamination from the 200 Areas which reached CGS over six years ago (see Section 2.4.13.1) has not been detected at WNP-1/4. This substantiates that the WNP-1/4 wells do not draw from the unconfined aquifer or, alternatively, the hydraulic conductivities are much less than assumed.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-13-050 2.4-29 It should also be noted that if Ben Franklin Dam were ever constructed, the concentration reduction factors at the river bank would be even larger than those noted above. This would be true, because the groundwater gradient (thus, the groundwater velocity) would be decreased as shown in Figure 2.4-19.

2.4.13.4 Monitoring or Safeguard Requirements Plant water systems result in releases to the ground at a number of locations. Sanitary wastewater is routed to a central treatment system comprised of lined aeration lagoons and stabilization ponds. This treatment plant also receives wastes from the Plant Support Facility, WNP-1 and WNP-4, and the DOE's 400 Area. Periodically the treated effluent is discharged to percolation beds.

As discussed in Section 2.4.2.3, the storm water drainage system discharges to lined ponds northeast of the plant (see additional description in Section 9.3.3.2.3.1). Such sources as water treatment filter backwashes, heating, ventilating, and air conditioning (HVAC) air wash units, and some building sumps and floor drains (see Section 9.3.3.2.3) also contribute to flow in the storm water system. Periodic testing and flushing of the fire protection system and cleaning of the cooling towers and standby service water ponds result in localized discharges of water to the ground.

Monitoring of groundwater and plant-related discharges to ground is performed as described in the ODCM.

2.4.13.5 Design Bases for Subsurface Hydrostatic Loadings CGS does not employ permanent dewatering systems. Site groundwater conditions are presented in Section 2.5.4.6 and the design bases for subsurface hydrostatic loadings are given in Section 3.4.

The design-basis groundwater elevation used for subsurface hydrostatic loadings is 420 ft msl and was predicated on the possible future construction of Ben Franklin Dam at RM 348. As noted in Section 2.4.13.1, planning for the dam has been terminated. The same section notes that the water table beneath CGS would rise to less than 405 ft msl if the dam were to be completed. The actual water table beneath the project is about 385 ft msl (see Sections 2.4.13.1 and 2.5.4.6). The design-basis groundwater level is adequate to account for seepage from the ultimate heat sink spray ponds or the rupture of any Seismic Category I or nonseismic pipe. As discussed in Section 3.8.4.1.5, the two, 250-ft2 reinforced-concrete spray ponds are designed to Seismic Category I requirements and are designed to mitigate any possible water leakage. The bottom of the spray ponds are at 417 ft msl and the ponds are designed for external hydrostatic loading to 420 ft msl. The maximum combined leakage from the two ponds during the initial filling sequences was 120 gpm. It may be inferred from previous studies (Reference 2.4-7) that continued leakage cannot affect the groundwater level COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-30 beneath the ponds or other safety-related structures, the closest of which (500+ ft away) is the diesel generator building with a foundation at 434 ft msl. These early CGS hydrologic studies evaluated the effect of cooling pond leakage and cooling tower blowdown at the project site. Equivalent leakage/discharge rates used in these studies were very much greater than leakage from the spray ponds. For example, the continuous discharge of 2700 gpm of cooling tower blowdown to the depression just east of CGS was estimated to raise the water table about 20 ft beneath the point of discharge (Reference 2.4-7). Based on these previous studies, it can be concluded that the minimal amount of spray pond leakage will have no influence on the design-basis groundwater elevation of 420 ft msl. With respect to a pipe break, the 144-in. circulating water system pipe on the discharge side of the condenser would produce the maximum release of water. The maximum quantity of water released from such a rupture is 199,180 ft3. This discharge would have a negligible (less than 1 in.) and temporary effect on the groundwater level. Failure of the pipe at its closest proximity to a safety-related building may result in temporary saturation of the backfill. This material has been recompacted to a minimum relative density of 75% and an average relative density of 85%. As discussed in Section 2.5.4.8, these densities are not susceptible to liquefaction for motions associated with the safe shutdown earthquake, and as discussed in Section 2.5.4.10, temporary saturation would not significantly reduce the bearing capacity of the densely compacted backfill. A continuous but undetected leak from any major pipe would not influence the groundwater level enough to affect plant structures. This may be deduced from the time factors and water table rises predicted from a number of scenarios in the above mentioned hydrologic studies (Reference 2.4-7).

2.4.14 TECHNICAL SPECIFICATIONS AND EMERGENCY OPERATION REQUIREMENTS The worst hydrological condition, as discussed in this section, is a flood caused by a postulated PMP event. This flood does not create an adverse hydrological condition on safety-related equipment. Emergency flood protection procedures are therefore unnecessary.

2.4.15 REFERENCES

2.4-1 Woods, V. W., "A Summary of Columbia River Hydrographic Information Pertinent to Hanford Works - 1894 to 1954," HW-30347, February 24, 1954.

2.4-2 Memorandum Report Columbia River Basin Lower Columbia River Standard Project Flood and Probable Maximum Flood, U.S. Army Engineers, North Pacific Division, Portland, OR, September 1969.

2.4-3 "Probable Maximum Precipitation," Hydrometeorological Report No. 43, U.S. Weather Bureau (now NOAA), Northwest States, 1966.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-31 2.4-4 Corps of Engineers, North Pacific Division, letter to V. C. St. Clair, Atomic Energy Commission, Richland Office, November 2, 1970. 2.4-5 Corps of Engineers, North Pacific Division, letter to M. J. Hroncich, Burns and Roe Inc., February 7, 1972.

2.4-6 Corps of Engineers, North Pacific Division, letter to M. J. Hroncich, Burns and Roe Inc., February 14, 1972. 2.4-7 Final Report on Hydrology Studies of the WNP-2 Site, July 1971, and Addendum I to Final Report on Hydrology Studies of the WNP-2 Site, by Battelle Northwest, Richland, WA, to Burns and Roe Inc., July 1971. 2.4-8 Design of Small Dams, U.S. Bureau of Reclamation, 1977.

2.4-9 "Water Surface Profiles," Vol. 6 Hydrologic Engineering Methods for Water Resources Development, U.S. Army Corps of Engineers, Hydrologic Engineering Center, July 1975.

2.4-10 Shore Protection Manual, U.S. Army Corps of Engineers, Coastal Engineering Research Center, 1975.

2.4-11 "Wave Runup and Wind Setup on Reservoir Embankments," Engineering Technical Letter No. 1110-2-221, Department of the Army, Corps of Engineers, November 29, 1976.

2.4-12 Artificial Flood Possibilities on the Columbia River, Corps of Engineers, Washington District, Washington, DC, November 20, 1951.

2.4-13 Rockwood, D. M, letter to R. Chitwood, "Preliminary Estimate of Upstream Dam Failure Effects," June 21, 1972.

2.4-14 Arthur, H. G., letter to J. J. Stein, "Behavior of Grand Coulee Dam and Forebay Dam When Subjected to Overtopping," August 1, 1972. 2.4-15 Artificial Flood Considerations for Columbia River Dams, Corps of Engineers, U.S. Army Engineer District, Seattle, WA, August 1963. 2.4-16 Eugene Isaacson, Calculations of Severe Floods in a Developed River, January 1965.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-32 2.4-17 Artificial Flood Considerations for Columbia River Below Chief Joseph Dam to Richland, Washington, U.S. Army, Corps of Engineers North Pacific Division, Portland, OR, January 1968. 2.4-18 Safety Evaluation by the Division of Reactor Licensing, U.S. Atomic Energy Commission in the matter of Portland General Electric Company, Pacific Power and Light Company, City of Eugene, OR, Trojan Nuclear Plant, Docket No. 50-344, pp. 11-12. 2.4-19 Jaske, R. T., and Synoground, M. O., "Effect of Hanford Plant Operation on the Temperature of the Columbia River, 1964-Present," BNWL-1345, Battelle, Pacific Northwest Laboratories, Richland, WA, November 1970. 2.4-20 "Columbia North Pacific Region Water Resources Appendix V," Volume 1, March 1969.

2.4-21 Columbia River Instream Resource Protection Program, Department of Ecology, Olympia, WA, June 1980, pp. 61-67.

2.4-22 Vertical Mixing Characteristics of the Columbia River at RM 351.75, WNP No. 2, Battelle Pacific Laboratories, Richland, WA, March 16, 1972.

2.4-23 Preoperational Environmental Monitoring Studies Near WNP-1, 2, and 4 August 1978 Through March 1980, WPPSS Columbia River Ecology Studies Vol. 7, Beack Consultants, Inc., Portland, OR, June 1980.

2.4-24 Kannberg, L. D., Mathematical Modeling of the WNP-1/2/4 Cooling Tower Blowdown Plumes, Battelle Pacific Northwest Laboratories, Richland, WA, March 1980.

2.4-25 McGhan, V. L., and Damschen, D. W., Hanford Wells, PNL-2894, Battelle Pacific Northwest Laboratories, Richland, WA, May 1979.

2.4-26 Harty, Harold, "The Effects of Ben Franklin Dam on the Hanford Site," PNL-2821, Battelle, Pacific Northwest Laboratories, Richland, WA, April 1979.

2.4-27 Bierschenk, W. H., "Aquifer Characteristics and Ground Water Movement at Hanford," HW-60601, June 9, 1959.

2.4-28 Bierschenk, W. H., "Hydraulic Characteristics of Hanford Aquifers," HW-48916, March 3, 1957.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-33 2.4-29 Honstead, J. F., McConiga, M. W., and Raymond, J. R., "Gable Mountain Ground Water Tests," HW-34532, January 21, 1955. 2.4-30 Gephart, R. E., Spane, F. A., Leonhart, L. S., Palombo, D. A., Strait, S. R., "Pasco Basin Hydrology", Hydrologic Studies within the Columbia Plateau, Washington - An Integration of Current Knowledge, (RNO-BWI-ST-5), by Rockwell Hanford Operations, Richland, WA, October 1979.

2.4-31 Newcomb, R. C., Strand, J. R. and Frank, F. J., "Geology and Ground Water Characteristics of the Hanford Reservation of the U.S. Atomic Energy Commission," Professional Paper # 717, USGS., Washington, 1972.

2.4-32 Cole, C. R., and Reisenauer, A. E., "Variable Thickness Transient Model Assumptions and Boundary Conditions," Battelle Pacific Northwest Laboratories, Richland, WA, August 1974.

2.4-33 Environmental Monitoring Report on the Status of Groundwater Beneath the Hanford Site, January- December 1975, BNWL-2034, Battelle, Pacific Northwest Laboratories, Richland, WA, January 1977.

2.4-34 Bramson, O. P. E., and Corley, J. P., "Hanford Environmental Surveillance Routine Program," Master Schedule -CY 1973, BNWL-B-234, Battelle, Pacific Northwest Laboratories, Richland, WA, December 1972.

2.4-35 Newcomb, R. C., "Some Preliminary Notes on Ground Water in the Columbia Basalt," Northwest Sciences, Vol. 33, 1, 1959, pp. 1-18.

2.4-36 LaSala, A. M., Jr., Doty, G. C., and Pearson, F. S., "A Preliminary Evaluation of Regional Ground Water Flow in South-Central Washington," USGS Open File Report, January 1973.

2.4-37 Parker, G. G., and Piper, A. M., "Geologic and Hydrologic Features of the Richland Area, WA, Relevant to Disposal of Waste at the Hanford -Directed Operations of the Atomic Energy Commission," Interior Report 1, USGS Report to Atomic Energy Commission, 101 pages, 5 Illus., 1949.

2.4-38 Kipp, K. L., and Mudd, R. D., "Selected Water Table Contour Maps for the Well Hydrographs and Hanford Reservation, 1944-1973," BNWL-1797, Battelle, Pacific Northwest Laboratories, Richland, WA.

2.4-39 Serne, R. J., Routson, R. C., and Cochran, D. A., "Experimental Methods for Obtaining PERCOL Model Input and Verification Data," BNWL-1721, Battelle Pacific Northwest Laboratories, Richland, WA, 1973, p. 24.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-34 2.4-40 Rouston, R. C., and Serne, R. J., "Experimental Support Studies for the PERCOL and Transport Models," BNWL-1719, Battelle Pacific Northwest Laboratories, Richland, WA, 1972, pp. 37, B-1, and B-2.

2.4-41 Carslaw, H. S., and Jaeger, J. C., Conduction of Heat in Solids, Oxford University Press, London, England, 1959.

2.4-42 Codell, R. B., and Schreiher, D. L., "NRC Models for Evaluating the Transport of Radionuclides in Groundwater," Proceedings of the Symposium on Management of Low Level Radioactive Waste, Pergamon Press, 1979, pp. 1193-1212.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-35 Table 2.4-1 Major Columbia River Basin Dams Location Dams River River Miles from Site Usable Storage 103 ac-ft Upstream Mica Columbia (Can) 666 12,000 Duncan Duncan 1,400 Arrow Columbia (Can) 429 7,090 Libby Kootenai 642 5,000 Hungry Horse South Fork Flathead 3,160 Kerr Clark Fork 1,219 Albeni Falls Pend Oreille 483 1,153 Grand Coulee Columbia 245 5,200 Chief Joseph Columbia 193 -- Wells Columbia 164 117 Chelan Chelan 152 677 Rocky Reach Columbia 122 120 Rock Island Columbia 101 -- Wanapum Columbia 64 389a Priest Rapids Columbia 45 170a Downstream McNary Columbia 60 John Day Columbia 136 The Dalles Columbia 160 Bonneville Columbia 206 a Storage not available for flood regulation.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-36 Table 2.4-2 Columbia River Temperatures Near Columbia Generating Station MONTHLY AVERAGE WATER TEMPERATURE, IN C, AT RICHLAND, WA Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Average 1965 6.1 5.4 6.3 9.1 11.0 14.2 17.3 19.8 18.5 16.4 12.6 8.4 12.1 1966 6.9 6.2 6.8 10.3 12.1 13.5 16.2 18.8 19.4 15.6 12.6 9.5 12.2 1967 7.4 7.0 6.6 8.8 12.0 13.9 17.0 20.2 19.4 16.1 12.0 7.8 12.4 1968 5.7 5.0 6.0 8.8 12.8 14.3 17.0 18.7 18.3 15.0 11.4 7.4 11.7 1969 2.7 1.9 4.3 8.0 11.4 15.3 17.9 19.3 18.6 15.2 11.7 7.0 11.1 1970 5.3 4.9 5.7 7.9 11.7 15.4 19.0 19.9 17.5 14.9 10.6 5.9 11.6 1971 4.2 3.4 3.8 7.0 11.1 12.9 16.4 19.5 17.8 15.0 10.7 6.2 10.7 1972 3.3 2.2 3.7 7.0 11.0 13.3 15.5 18.1 16.9 14.0 10.5 6.1 10.1 1973 3.2 3.0 4.7 7.8 12.9 15.6 18.3 19.6 18.3 15.0 9.9 7.6 11.3 1974 3.2 3.2 5.2 8.2 11.3 13.7 17.4 19.4 18.8 15.4 11.5 7.9 11.3 Average 1965-1974 4.7 4.2 5.3 8.3 11.7 14.2 17.2 19.3 18.4 15.3 11.4 7.4 11.4 Minimum Daily 0.2 0.7 2.4 5.1 8.6 11.2 14.2 17.3 14.6 11.1 7.7 2.4 -- Maximum Daily 8.3 8.3 8.6 12.8 15.0 17.7 20.4 21.5 21.1 18.5 15.9 11.3 -- Records since June 1964. MONTHLY AVERAGE WATER TEMPERATURE, IN C, AT PRIEST RAPIDS DAM, WA 1961 5.4 4.7 4.7 7.4 10.4 13.7 17.3 18.9 17.8 14.9 10.4 6.6 11.0 1962 4.1 3.6 3.6 6.5 10.0 13.7 16.1 17.4 17.1 14.8 11.9 8.9 10.6 1963 5.3 3.8 4.6 6.5 10.4 14.0 16.6 18.4 18.3 16.3 11.9 7.7 11.2 1964 5.5 4.6 4.7 7.2 9.7 12.8 15.3 17.1 16.3 14.6 10.8 6.3 10.4 1965 4.4 3.3 4.1 6.6 10.0 13.3 16.1 18.4 17.3 15.3 11.9 7.8 10.7 1966 4.8 4.1 4.5 7.8 10.6 12.4 15.3 17.5 17.5 14.6 11.6 8.4 10.8 1967 5.9 5.7 5.0 6.8 10.1 13.3 16.1 18.5 18.2 15.4 11.3 7.2 11.1 1968 4.6 3.3 4.6 7.1 11.1 13.4 16.1 17.5 17.2 14.2 10.9 6.8 10.6 1969 2.4 1.5 3.4 7.2 10.8 14.6 17.1 18.2 17.7 14.8 11.5 7.6 10.6 1970 4.3 4.1 4.8 6.8 10.9 14.8 18.0 19.2 17.5 15.2 10.6 6.2 11.0 1971 4.0 3.5 3.6 6.6 10.7 12.6 15.3 18.4 17.2 15.2 11.3 6.8 10.4 1972 3.6 1.9 4.0 7.2 10.6 12.9 15.2 17.3 16.8 15.4 11.3 7.3 10.3 1973 2.3 2.9 4.8 7.7 12.5 15.4 17.6 18.8 17.8 15.2 10.3 7.7 11.1 1974 4.0 3.0 4.9 7.7 10.8 13.6 17.2 18.7 18.4 15.5 11.8 8.6 11.2 Average 1965-1974 4.0 3.3 4.4 7.2 10.8 13.6 16.4 18.3 17.6 15.1 11.3 7.4 10.8 Minimum Daily 0.3 0.3 2.2 4.3 7.5 10.6 13.1 16.6 15.3 12.2 7.7 2.3 -- Maximum Daily 7.6 6.2 6.9 10.1 14.6 17.1 19.3 20.2 20.0 18.7 14.4 10.5 -- Records since August 1960. Recorded values adjusted by computer-simulation to compensate for measurement errors and missing data.

COLUMBIA GENERATING STATION Amendment 55 FINAL SAFETY ANALYSIS REPORT May 2001 LDCN-00-000 2.4-37 Table 2.4-3 Downstream Surface Water Users Location of Diversion Approximate Miles Quantity Type Name Township Range Section Downstream (cfs) Usea Energy Northwest 11 28 2 -- 90 IN Peter Kewit and Sons 11 28 2 -- 1 I L. L. Bailey 11 28 24 4 2 I H. D. Loyd 11 28 24 4 0.99 D,I Central Premix Concrete Company 11 28 27 4 2 IN Battelle Memorial Institute 10 28 14 8 4.4 I University of Washington 10 28 23 9 1.75 I City of Richland 10 28 24 9 0.67 D City of Richland 10 28 25 12 31 D City of Richland 10 28 25 12 23.25 D City of Richland 10 28 25 12 31 D City of Richland 10 28 35 12 93 D E. C. Watts 9 28 1 13 0.31 D,I H. S. Petty 9 28 1 13 0.48 I N. H. and M. E. Ketchersid 9 28 1 13 1.66 I G. C. Walkley 9 28 1 13 2.32 I R. T. Justesen, et al. 9 28 12 15 2.54 I Central Premix Concrete Company 9 28 12 15 1.10 IN City of Richland 9 28 13 17 2.0 I Benton County 9 29 28 19 1.0 I City of Kennewick 9 30 31 23 55.7 D City of Pasco 9 30 31 23 35.0 D F. J. Henckel 8 30 14 27 0.015 I Allied Chemical 8 30 14 27 3.55 IN Chevron Chemical 8 30 23 28 3.77 IN Chevron Chemical 8 30 23 28 40 IN Phillips Pacific Chemical Company 8 30 24 28 82 IN Phillips Pacific Chemical Company 8 30 24 28 20 IN Boise Cascade Corporation 7 31 10 34 24.5 IN L. D. Hoyte, et al. 7 31 14 35 179.8 I D. Howe 7 31 23 36 6.4 I Crawford and Sons 6 30 27 47 32.8 I Barbarosa Farms 6 30 27 47 20 I Crawford and Sons 6 30 27 47 7.6 I Rainier National Bank 6 30 27 47 9.4 I Anderson and Coffin 5 29 5 49 242 I Horse Heaven Farms 5 29 6 50 82 I Horse Heaven Farms 5 29 6 50 550 I Horse Heaven Farms 5 29 6 50 290 I Anderson and Coffin 5 29 6 50 242 I a D - Domestic or municipal uses I - Irrigation and other agricultural uses IN - Industrial Includes only those water rights for which a permit or certificate has been issued COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-38 Table 2.4-4 Mean Discharges in CFS of Columbia River Below Priest Rapids Dam, Modified to 1970 Conditions Water Year Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Annual 1928 224000 109900 90900 1929 82300 78400 101100 103000 108000 72600 85200 62000 71300 87600 97000 94300 86900 1930 87900 89800 102700 93500 90700 83100 72500 81700 90200 98800 97600 92700 90100 1931 86800 89600 100000 82200 90800 88400 74500 81700 104000 102200 99400 85800 90400 1932 87400 88700 102000 95000 109200 77800 90700 157500 156700 74600 97800 90600 102300 1933 89600 69700 102700 128800 167100 97900 118900 185900 196600 180300 121900 100200 130000 1934 100600 104200 128000 139600 203400 196700 243100 221200 168800 104500 100000 101000 150900 1935 82000 72400 109200 132100 132000 111300 117600 147500 156900 131100 99300 96900 115700 1936 90200 86200 107900 119400 79800 80400 81500 160500 123300 83400 93200 89400 99600 1937 87600 87500 105400 96600 100600 84400 63500 70400 76900 87800 102500 91500 87900 1938 89300 83100 88700 111000 124100 86800 110700 142400 146800 154100 90400 89200 109700 1939 83400 77100 91700 127200 90400 83000 108500 100000 112400 95500 96900 90800 96400 1940 85800 85400 90500 133200 98000 89200 110700 89700 101700 94100 96000 91600 97200 1941 84300 79600 92500 99400 92200 87900 137400 76900 73200 84000 91500 88700 90600 1942 96000 82700 91400 114100 119000 84600 115900 105300 148400 101400 102000 88300 104100 1943 87900 65800 86800 105600 150600 116000 132400 202600 134300 147700 101300 88900 118300 1944 81300 77200 96800 99300 110600 78700 88200 88000 69100 81200 94600 84400 87400 1945 90100 90900 103600 88500 94000 86500 77800 112800 67800 88800 99300 87400 90600 1946 86200 85700 92500 95600 117700 90800 112200 178100 170900 134500 94400 91100 112500 1947 79600 81300 93100 116000 137800 135200 155900 184400 163400 136300 89900 85500 121500 1948 94700 96000 113900 113200 202800 166700 137700 193400 257600 194700 122900 101900 149600 1949 88000 83600 97700 126000 114000 80000 123000 166400 181600 82700 92200 87800 110200 1950 79000 69500 106800 123300 155200 145400 136400 197500 200200 211900 114800 96200 136400 1951 91800 87900 102600 115400 223400 186200 195600 188800 171300 174300 110300 91700 144900 1952 94200 98800 112200 126500 155200 113300 134600 172400 135800 145100 88700 85900 121900 1953 85500 83900 103900 95500 124800 87800 98700 174000 168300 141400 99000 89200 112700 1954 83600 89800 110300 122100 153600 135200 124200 191200 224900 228400 163600 114400 145100 1955 98700 103400 126600 132400 143900 102700 110500 104300 181800 193300 111900 91000 125000 1956 95700 94500 97000 108100 206500 200600 173500 245800 212600 200400 103600 90700 152400 1957 87400 82900 109400 132100 145100 101200 113600 182700 176500 120900 89000 86900 119000 1958 77500 75200 83300 120200 123700 107300 125000 172800 172900 Mean 87800 84700 101700 113200 132100 108600 119000 147900 147200 132800 102400 91800 114100 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-39 Table 2.4-5 Dependable Yield, Columbia River Below Priest Rapids Dam, Washington Consecutive Years of Lowest Mean Flow Inclusive Years Lowest Mean Flow (cfs) Percent of 1929-1958 Mean 1 1937 86,600 75.9 2 1930-31 89,900 78.8 3 1929-31 92,900 81.4 4 1929-32 95,800 84.0 5 1937-41 96,400 84.5 6 1937-42 97,300 85.3 7 1936-42 98,400 86.2 8 1937-44 99,000 86.8 9 1937-45 97,900 85.8 10 1936-45 98,600 86.4 11 1929-58 114,100 100.0 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-40 Table 2.4-6 Major Geologic Units in the Hanford Region and Their Water-Bearing Properties System Series Geologic Unit Material Water-Bearing Properties Fluviatile and glaciofluviatile sediments and the Touchet formation

(0-200 ft thick) Sands and gravels occurring chiefly as glacial outwash. Unconsolidated, tending toward coarseness and angularity of grains, essentially free of fines. Where below the water table, such deposits have very high permeability and are capable of storing vast amounts of water.

Highest permeability value determined was 12,000 ft/day. Pleistocene Palouse soil Wind deposited silt. Occurs everywhere above the water table. Quaternary Ringold formation (200-1200 ft thick) Well-bedded lacustrine silts and sands and local beds of clay and gravel.

Poorly sorted, locally semi-consolidated or cemented. Generally divided into the lower "blue clay" portion which contains considerable sand and gravel, the middle conglomerate portion, and the upper silts and fine sand portion. Has relatively low permeability; values range from 1 to 200 ft/day. Storage capacity correspondingly low. In very minor part, a few beds of gravel and sand are sufficiently clean that permeability is moderately large; on the other hand, some beds of silty clay or clay are essentially impermeable. Miocene and Pliocene Columbia River basalt series (10,000 ft thick) Basaltic lavas with interbedded sedimentary rocks, considerably deformed. Underlie the unconsolidated sediments. Rocks are generally dense except for numerous shrink-age cracks, interflow scoria zones, and interbedded sediments. Permeability of rocks is small (e.g.,

0.002 to 9 ft/day) but transmissivity of a thick section may be considerable (70 to 700 ft2/day)

Amendment 55May 2001Hydrographic Map990306.302.4-1FigureForm No. 960690Draw. No.Rev.Yakima RiverRichlandPascoKennewickWalla Walla RiverSnake RiverN. Richland20 mi.15 mi.10 mi.5 mi.2 mi.PlantSiteColumbia RiverCoulee CreekRattlesnake CreekCrab CreekPowerColumbia RiverColumbia Generating StationFinal Safety Analysis Report

Discharge and Temperature of the Columbia Riverat Priest Rapids990306.062.4-4FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.Temperature (C)Q (kcfs)Record TMax19.9 (1963)1020Jan1020Feb1020Mar1020Apr1020May1020June1020July1020Aug1020Sept1020Oct1020Nov1020Dec0246810 1214160/181000/18200400 500 600700800(E)Estimated from high water marks at Wenatchee(I)Based on USGS-published weekly averages atPriest Rapids for the period 1953 - 67(2)USGS-Published daily averages atPriest Rapids.(3)Daily averages for the USGS Gaging Stationat Priest Rapids.(4)Based on 15-day moving averages for the1960- 68 period of record at Priest Rapids.1963(3)1969 and Record TMin 0.0Normal (I)1969 (2)1969 TMax19.71969 QMax320Normal (4)1956 QMax 5.541948 QMax 693Record QMax 740 9Discharge (Q) and temperature (T) of the Columbia River at Priest Rapids during 1969 with miscellaneous data for prior years (p)(p) Unless otherwise specified, pre-1960 data are for Trinidad. A gaging station about 23 miles downstream from WenatcheeColumbia Generating StationFinal Safety Analysis Report Columbia River Water Surface ProfilesRiver Miles 323 to 358990306.072.4-5FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.1,360,000 CFS725,000 CFS300,000 CFS36,000 CFS725,000 CFS300,000 CFS36,000 CFS1,360,000 CFS500480460440420400380360340358Elevation Above MSLRiver Miles355350345340330325335328Elevation Above MSL7,200,000 CFS5,969,000 CFS4,768,000 CFSGround El. at Plant SiteGround El. atMake-up Water Pumphouse6,800,000 CFS5,646,000 CFS4,512,000 CFS2,200,000 CFSMouth of Yakima RiverMouth of Snake RiverColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001PMF Hydrograph Due to Thunderstorm PMP990306.312.4-7FigureForm No. 960690Draw. No.Rev.Time (Hours)24681012141618246 8101214 16 182022Probable Maximum FloodHydrograph @ X-sec 1Peak Flow = 21,400 cfsColumbia Generating StationFinal Safety Analysis Report

Amendment 57December 2003Probable Maximum Precipitation ChannelCross Sections990306.082.4-9FigureForm No. 960690Draw. No.Rev.14364324284244364324284244204364324284244204164364324284244204164364324284244204164364324284244204164124084364324284244204164124084364324284244204164124084364324284244204164364324284244204163000250020001500 100050005001000 150035003000250020001500100050005001000436432428424420200015001000500050010001500243598761011Distance (feet)Overbank areasElevation (feet MSL)Columbia Generating StationFinal Safety Analysis ReportLDCN-02-000 Amendment 55May 2001Water Surface Profile990306.322.4-10FigureForm No. 960690Draw. No.Rev.1234576891011X-SecCross Section NumbersElevation (Feet MSL)Distance (1000 Feet)024681012141618202224262830404406408410412414416418420422424426428430Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Effective Fetch Diagram990306.332.4-11FigureForm No. 960690Draw. No.Rev.Scale - 1" = 2000'Outline of MaximumStillwater PondEast Spray PondCentral Radial6789101112131415R1R2R3R4R5Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Computed Long-Term Temperature Trends on theColumbia River at Rock Island Dam(1938 - 1962)990306.342.4-12FigureForm No. 960690Draw. No.Rev.706050 4032Upper ExtremeMeanLower ExtremeCalender YearsRiver Temperature, °F19401948195619641972Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001River Elevation at Low Flows - River Mile 352990306.352.4-13FigureForm No. 960690Draw. No.Rev.360350340330Flow KCFSElevation - ft above MSL020304050607010Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Duration Curves Columbia River, Priest RapidsDam990306.362.4-14FigureForm No. 960690Draw. No.Rev.3002001000Percent of Time Equaled or ExceededDischarge, Thousand Cubic Feet per Second0203040506070809010010Period: 1929 - 19581970 ConditionsAnnualMonthlyColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Frequency Curves of High and Low Flows for theColumbia River Below Priest Rapids Dam990306.372.4-15FigureForm No. 960690Draw. No.Rev.Period1 Month3 Month6 Month12 Month6 Month3 Month 1 MonthPeriod of record 1929 - 19581970 ConditionsHigh Flows30020010050Low FlowsRecurrence Interval, YearsMean Discharge, 1000 cfs1.11.523510203050mean 115,000 cfs12 monthsColumbia Generating StationFinal Safety Analysis Report

Amendment 57December 2003Hanford Reservation Water Table Map (December1975)010126.532.4-18FigureForm No. 960690Draw. No.Rev.Yakima RiverColumbia RiverSource:Atlantic Richfield Hanford CompanyReport ARH -ST-137 Dated Nov. 1976Columbia RiverHanfordReservationGableMountainPond434(132)B Pond574(172)West Lake403(123)200 W200 EU Pond656(200)RichlandWater Table Contoursin Feet and (Meters) above Mean Sea LevelPonds with Water Surfacein Feet and (Meters) above Mean Sea LevelKilometers1005Miles1005LEGEND:470(143)350(107)360(110)370(113)380(116)390(119)400(122)410(125)420(128)430(131)440(114)490(149)510 (155)500 (152)0480 (146)460(140)450(137)LDCN-02-000Columbia Generating StationFinal Safety Analysis Report

Rev.FigureDraw. No.Form No. 960690LDCN-06-000Amendment 59December 2007020361.092.4-22Nitrate (NO3) Concentrations (December 1976)Columbia Generating StationFinal Safety Analysis Report

Well Hydrographs990306.092.4-27.1FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.506070370360380390Water Elevation (FT-MSL)506070506070Calender YearWell No. 699-23Casing Elev = 477.14Well No. 699-17-5 Casing Elev = 433.19Well No. 699-9-E2 Casing Elev = 418.48506070360350370Water Elevation (FT-MSL)506070506070506070Calender YearWell No. 699-20-ESTCasing Elev = 467.69Well No. 699-14E6T Casing Elev = 458.38Well No. 699-20-E12 Casing Elev = 437.25Well No. 699-10-E12 Casing Elev = 430.86Columbia Generating StationFinal Safety Analysis Report Well Hydrographs990306.392.4-27.2FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.Water Elevation, Ft-MSL385384 383382381380Well Number 699-20-E12-P37962Calender YearCalender YearCalender Year657075Well Number699-10-E12-P391390389388387 386657075Well Number699-14-E6P6668707274389388387386Water Elevation, Ft-MSLCasing Elevation437.45 Ft-MSL646668707274Well Number699-20-E5-PCasing Elevation467.04 Ft-MSLCasing Elev.

458.44 Ft-MSLCasing Elev.

431.20 Ft-MSLColumbia Generating StationFinal Safety Analysis Report COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 LDCN-05-050 2.5-1 2.5 GEOLOGY, SEISMOLOGY, AND GEOTECHNICAL ENGINEERING The information discussing the geology, seismology, and geotechnical engineering is contained in a technical memorandum, TM-2143, "Geology, Seismology, and Geotechnical Engineering Report." This report is incorporated by reference into the FSAR and as such is subject to the same controls as the FSAR.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS Section Page LDCN-09-044 2-i 2.1 GEOGRAPHY AND DEMOGRAPHY ................................................ 2.1-1 2.1.1 SITE LOCATION AND DESCRIPTION ........................................... 2.1-1 2.1.1.1 Specification of Location ............................................................. 2.1-1 2.1.1.2 Site Area Map .......................................................................... 2.1-1 2.1.1.3 Boundaries for Establishing Effluent Release Limits ........................... 2.1-2 2.1.2 EXCLUSION AREA AUTHORITY AND CONTROL .......................... 2.1-2 2.1.2.1 Authority ................................................................................ 2.1-2 2.1.2.2 Control of Activities Unrelated to Plant Operation .............................. 2.1-4 2.1.2.2.1 Industrial Development Complex ................................................ 2.1-4 2.1.2.2.2 618-11 (Wye) Waste Burial Ground ............................................. 2.1-4 2.1.2.3 Arrangements for Traffic Control .................................................. 2.1-5 2.1.2.4 Abandonment or Relocation of Roads ............................................. 2.1-5 2.1.3 POPULATION DISTRIBUTION ..................................................... 2.1-5 2.1.3.1 Population Within Ten Miles ........................................................ 2.1-6 2.1.3.2 Population Between Ten and Fifty Miles .......................................... 2.1-7 2.1.3.3 Transient Population .................................................................. 2.1-7 2.1.3.4 Low Population Zone ................................................................. 2.1-7 2.1.3.5 Population Center ..................................................................... 2.1-7 2.1.3.6 Population Density .................................................................... 2.1-7 2.

1.4 REFERENCES

........................................................................... 2.1-8 2.2 NEARBY INDUSTRIAL, TRANSPORTATION, AND MILITARY FACILITIES ................................................................................ 2.2-1 2.2.1 LOCATION AND ROUTES .......................................................... 2.2-1 2.2.2 DESCRIPTIONS ......................................................................... 2.2-3 2.2.2.1 Description of Facilities .............................................................. 2.2-3 2.2.2.2 Description of Products and Materials ............................................. 2.2-6 2.2.2.3 Pipelines ................................................................................ 2.2-7 2.2.2.4 Waterways .............................................................................. 2.2-7 2.2.2.5 Airports ................................................................................. 2.2-8 2.2.2.6 Projection of Industrial Growth ..................................................... 2.2-8 2.2.3 EVALUATION OF POTENTIAL ACCIDENTS ................................. 2.2-8 2.2.3.1 Determination of Design Basis Events ............................................. 2.2-8 2.2.3.2 Effects of Design Basis Events ...................................................... 2.2-11 2.

2.4 REFERENCES

........................................................................... 2.2-11 COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS (Continued)

Section Page 2-ii 2.3 METEOROLOGY ......................................................................... 2.3-1 2.3.1 REGIONAL CLIMATOLOGY .......................................................... 2.3-1 2.3.1.1 General Climate ....................................................................... 2.3-1 2.3.1.2 Regional Meteorological Conditions for Design and Operating Bases ....... 2.3-4 2.3.1.2.1 Severe Weather Phenomena ....................................................... 2.3-4 2.3.1.2.1.1 Heavy Rain, Snow, and Ice ..................................................... 2.3-4 2.3.1.2.1.2 Thunderstorms and Hail ......................................................... 2.3-4 2.3.1.2.1.3 Tornadoes .......................................................................... 2.3-6 2.3.1.2.1.4 Strong Winds ...................................................................... 2.3-7 2.3.1.2.1.5 High Air Pollution Potential (APP) and Dust Storm Potential ........... 2.3-8 2.3.1.2.1.5.1 Evaluation of August 11, 1955 and January 11, 1972 Dust Storms at Hanford ............................................................. 2.3-11 2.3.1.2.1.5.2 Hanford Dust Storm Climatology for Design and Operating Bases ... 2.3-13 2.3.1.2.2 Design Snow Load .................................................................. 2.3-14 2.3.1.2.3 Meteorological Data Used for Evaluation of Ultimate Heat Sink .......... 2.3-15 2.3.2 LOCAL METEOROLOGY .............................................................. 2.3-16 2.3.2.1 Data Comparisons ..................................................................... 2.3-16 2.3.2.1.1 Winds .................................................................................. 2.3-18 2.3.2.1.2 Moisture and Temperature ........................................................ 2.3-19 2.3.2.1.3 Monthly Precipitation .............................................................. 2.3-20 2.3.2.1.4 Fog .................................................................................... 2.3-20 2.3.2.1.5 Stability Summaries ................................................................. 2.3-21 2.3.2.2 Potential Influence of the Plant and Its Facilities on Local Meteorology .... 2.3-22 2.3.2.3 Local Meteorological Conditions for Design and Operating Bases ........... 2.3-23 2.3.2.4 Topographic Description ............................................................. 2.3-23 2.3.3 ONSITE METEOROLOGICAL MEASUREMENT PROGRAM ................... 2.3-23 2.3.3.1 Permanent Onsite Meteorological Tower and Instrumentation Characteristics ......................................................................... 2.3-24 2.3.3.2 Quality Assurance Program ......................................................... 2.3-26 2.3.3.2.1 Data Recovery During April 1, 1974 - March 31, 1976 ..................... 2.3-26 2.3.3.2.2 Maintenance and Calibration ..................................................... 2.3-28 2.3.3.2.3 Data Processing and Analysis .................................................... 2.3-28 2.3.3.2.4 Meteorological Monitoring Program During Plant Operation .............. 2.3-29 2.3.3.3 Other Meteorological Measurement Programs Considered for the Data Comparisons ............................................................................ 2.3-31 2.3.3.3.1 CGS Temporary Tower ............................................................ 2.3-31 COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS (Continued)

Section Page 2-iii 2.3.3.3.2 Hanford Meteorological Station .................................................. 2.3-31 2.3.3.4 Joint Stability - Wind Frequency Summaries ..................................... 2.3-31 2.3.4 SHORT TERM DIFFUSION ESTIMATES ........................................ 2.3-32 2.3.4.1 Objective ................................................................................ 2.3-32 2.3.4.2 Exclusion Area Boundary ............................................................ 2.3-32 2.3.4.3 Low Population Zone ................................................................. 2.3-33 2.3.4.4 Control Room .......................................................................... 2.3-33 2.3.4.5 Description of Sources ............................................................... 2.3-33 2.3.4.6 Control Room Intakes ................................................................ 2.3-34 2.3.4.7 Calculations ............................................................................ 2.3-34 2.3.5 LONG-TERM (ROUTINE) DIFFUSION ESTIMATES ............................. 2.3-35 2.3.5.1 Objectives ............................................................................... 2.3-35 2.3.5.2 Calculations ............................................................................ 2.3-36 2.

3.6 REFERENCES

........................................................................... 2.3-38 2.4 HYDROLOGY ENGINEERING ........................................................ 2.4-1 2.4.1 HYDROLOGIC DESCRIPTION ..................................................... 2.4-1 2.4.1.1 Site and Facilities ...................................................................... 2.4-1 2.4.1.2 Hydrosphere ............................................................................ 2.4-1 2.4.2 FLOODS .................................................................................. 2.4-4 2.4.2.1 Flood History .......................................................................... 2.4-4 2.4.2.2 Flood Design Considerations ........................................................ 2.4-4 2.4.2.3 Effects of Local Intense Precipitation .............................................. 2.4-5 2.4.3 PROBABLE MAXIMUM FLOOD ON STREAMS AND RIVERS ........... 2.4-6 2.4.3.1 Probable Maximum Precipitation ................................................... 2.4-7 2.4.3.2 Precipitation Losses ................................................................... 2.4-7 2.4.3.3 Runoff and Stream Course Models ................................................. 2.4-7 2.4.3.4 Probable Maximum Flood Flow .................................................... 2.4-8 2.4.3.5 Water Level Determinations ......................................................... 2.4-9 2.4.3.6 Coincident Wind Wave Activity .................................................... 2.4-9 2.4.4 POTENTIAL DAM FAILURES, SEISMICALLY INDUCED ................. 2.4-9 2.4.4.1 Dam Failure Permutations ........................................................... 2.4-10 2.4.4.2 Unsteady Flow Analysis of Potential Dam Failures ............................. 2.4-11 2.4.4.3 Water Level at Plant Site ............................................................. 2.4-11 2.4.5 PROBABLE MAXIMUM SURGE AND SEICHE FLOODING ............... 2.4-11 2.4.6 PROBABLE MAXIMUM TSUNAMI FLOODING .............................. 2.4-12 COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 Chapter 2 SITE CHARACTERISTICS TABLE OF CONTENTS (Continued)

Section Page 2-iv 2.4.7 ICE EFFECTS ........................................................................... 2.4-12 2.4.8 COOLING WATER CANALS AND RESERVOIRS ............................. 2.4-13 2.4.9 CHANNEL DIVERSIONS ............................................................ 2.4-13 2.4.10 FLOODING PROTECTION REQUIREMENTS ................................ 2.4-13 2.4.11 LOW WATER CONSIDERATIONS .................................................. 2.4-14 2.4.11.1 Low Flow in Streams ................................................................ 2.4-14 2.4.11.2 Low Water Resulting From Surges, Seiches, or Tsunami ..................... 2.4-15 2.4.11.3 Historical Low Water ............................................................... 2.4-15 2.4.11.4 Future Controls ....................................................................... 2.4-16 2.4.11.5 Plant Requirements .................................................................. 2.4-17 2.4.11.6 Heat Sink Dependability Requirements .......................................... 2.4-17 2.4.12 DISPERSION, DILUTION, AND TRAVEL TIMES OF ACCIDENTAL RELEASES OF LIQUID EFFLUENTS IN SURFACE WATERS ........... 2.4-17 2.4.13 GROUNDWATER ..................................................................... 2.4-18 2.4.13.1 Description and Onsite Use ........................................................ 2.4-18 2.4.13.2 Sources ................................................................................ 2.4-23 2.4.13.3 Accidental Effects.................................................................... 2.4-25 2.4.13.4 Monitoring or Safeguard Requirements .......................................... 2.4-29 2.4.13.5 Design Bases for Subsurface Hydrostatic Loadings ........................... 2.4-29 2.4.14 TECHNICAL SPECIFICATIONS AND EMERGENCY OPERATION REQUIREMENTS ..................................................................... 2.4-30 2.4.15 REFERENCES ......................................................................... 2.4-30 2.5 GEOLOGY, SEISMOLOGY, AND GEOTECHNICAL ENGINEERING ...... 2.5-1

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES Number Title Page 2-v 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site.....................................................................2.1-9 2.1-2 2000 Population Distribution by Compass Sector and Distance from the Site..........................................................2.1-12 2.2-1 Hanford Site Nuclear Facilities...............................................2.2-13 2.3-1 Average and Extremes of Climatic Elements at Hanford................2.3-43 2.3-2 Average Return Period and Existing Record for Various Precipitation Amounts and Intensity During Specified Time Periods at Hanford..............................................................2.3-45 2.3-3 Miscellaneous Snowfall Statistics (1946 through 1970)..................2.3-46 2.3-4 Tornado History Within 100 Miles of CGS................................2.3-47 2.3-5 Monthly and Annual Prevailing Directions, Average Speeds, and Peak Gusts: 1945-1970 at HMS........................................2.3-48 2.3-6 Speed and Direction of Daily Peak Gusts..................................2.3-49 2.3-7a CGS and HMS Hourly Meteorlogical Data, August 7-9, 1972 (Ultimate Heat Sink Studies)..................................................2.3-51 2.3-7b CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-52 2.3-7c CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-53 2.3-7d CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-54 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page 2-vi 2.3-7e CGS Hourly Meteorological Data, July 4-12, 1975 (Ultimate Heat Sink Studies)..................................................2.3-55 2.3-7f 24 Hour HMS Meteorological Profile for August 4, 1961..............2.3-56 2.3-7g Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing Second Through Thirtieth Day Pond Thermal Performance..........................................................2.3-57 2.3-7h Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing First Through Thirtieth Day Maximum Mass Loss........................................................................2.3-58 2.3-8a Summary of CGS Onsite Meteorological Data Collected During the First and Second Annual Cycles as Compared to Corresponding Hanford Meterological Station Data......................2.3-59 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975).................................................2.3-61 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970)..........................................2.3-66 2.3-10 Percent Frequency of Occurrence of Wind Direction at the Hanford Reservation............................................................2.3-70 2.3-11 Persistence of Wind Direction in One Sector (22.5 Degrees) from 4/74 through 3/75 at 33-ft Level......................................2.3-72 2.3-12 Persistence of Wind Direction in Two Sectors (45 Degrees) from 4/74 through 3/75 at CGS for 33-ft Level...........................2.3-74 2.3-12a Longest Persistence of Wind Direction in One (22.5 Degrees) and Two (45 Degrees) Sectors During First and Second Annual Cycles at 33-ft Level.................................................2.3-76 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2

SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page 2-vii 2.3-13 Percent Frequency of Occurrence of Wind Speed at the Hanford Reservation............................................................2.3-77 2.3-14 Diurnal Variation of 33-ft Elevation Dry Bulb Temperature (F°) at CGS and Monthly Average Dry Bulb Temperature (F°) at the Hanford Reservation.......................................................2.3-79 2.3-15 Diurnal Variation of 33-ft Elevation Wet Bulb Temperature (F°) at CGS and Monthly Average Wet Bulb Temperature (F°) at the Hanford Reservation............................................................2.3-80 2.3-16 Diurnal Variation of 33 ft Elevation Dew Point Temperature (F°) at CGS and Monthly Average Dew Point Temperature (F°) at the Hanford Reservation.......................................................2.3-81 2.3-17 Frequency of Occurrence, Dry Bulb Temperature (F°) Versus Time of Day from 4/74 through 3/75 for 33-ft Level....................2.3-82 2.3-18 Frequency of Occurrence, Wet Bulb Temperature (F°) Versus Time of Day from 4/74 through 3/75 for 33-ft Level....................2.3-83 2.3-19 Frequency of Occurrence, Dew Point Temperature (F°) Versus Time of Day from 4/74 through 3/75 for 33-ft Level....................2.3-84 2.3-20 Monthly Averages of Psychrometric Data Based on Period of Record (1950-1970).........................................................2.3-85 2.3-21 Diurnal Variation of Precipitation Intensity at CGS and Monthly Total Precipitation at the Hanford Reservation.................2.3-86 2.3-22 Frequency of Occurrence, Precipitation Versus Time of Day from 4/74 through 3/75 at CGS..............................................2.3-87 2.3-22a Annual Frequency of Occurrence of Wind Direction and Wind Speed Versus Precipitation Intensity.................................2.3-88 COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page LDCN-13-067 2-viii 2.3-23 Statistics on Fog at the Hanford Meteorology Station .................... 2.3-90 2.3-24 Percent Frequency Distribution of Wind Speeds During Hourly Observations of Fog at Pasco and at HMS ................................. 2.3-91 2.3-25 Percent Frequency of Occurrence of Stability at the Hanford Reservation............................................................ 2.3-92 2.3-26 Frequency of Occurrence T (F/200 ft) Versus Time of Day from 4/74 through 3/75 at CGS between 245 and 33-ft Levels ......... 2.3-94 2.3-27 Frequency of Occurrence, Sigma () Versus Time of Day from 4/74 through 3/75 at CGS for 33-ft Level .................................. 2.3-95 2.3-28 Joint Frequency Distribution of Wind Speed and Direction ............. 2.3-96 2.3-28A Joint Frequency Distribution of Wind Speed and Direction ............. 2.3-100 2.3-29 through 2.3-32 DELETED 2.3-33 Exclusion Area Boundary Accident /Q Desert Sigmas ................. 2.3-105 2.3-33a Exclusion Area Boundary /Q Values Desert Sigmas w/ Meander .... 2.3-106 2.3-34 Exclusion Area Boundary Accident /Q P-G Sigmas .................... 2.3-107 2.3-34a Exclusion Area Boundary /Q Values Pasquill-Gifford Sigmar w/ Meander and Building Wake Credit ..................................... 2.3-108 2.3-35 Low Population Zone Accident /Q Desert Sigmas ...................... 2.3-109 2.3-36 Low Population Zone Accident /Q P-G Sigmas ......................... 2.3-110 2.3-37 Control Room, Exclusion Area Boundary and Low Population Zone /Qs (S/m3) .......................................... 2.3-111 COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page LDCN-13-067 2-ix 2.3-38a CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-112 2.3-38b CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-113 2.3-38c CGS Calculations, Terrain Features, Desert Sigmas ..................... 2.3-114 2.3-38d CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-115 2.3-38e CGS Calculations, Terrain Features, Desert Sigmas ..................... 2.3-116 2.3-38f CGS Calculation, Terrain Features, Desert Sigmas ...................... 2.3-117 2.3-39a DELETED ....................................................................... 2.3-118 through 2.3-39f

2.3-40 Frequency of Wind Resuspension Periods at Hanford (1953-1970) ...................................................................... 2.3-119 2.3-41 Dust Concentration Dependency on Wind Speed and Direction at Hanford 1953-1970 .......................................................... 2.3-120 2.3-42 Hours Satisfying Dust Storm Criteria at Hanford (1953-1970) ......... 2.3-121 2.4-1 Major Columbia River Basin Dams ......................................... 2.4-35 2.4-2 Columbia River Temperatures Near Columbia Generating Station .... 2.4-36 2.4-3 Downstream Surface Water Users ........................................... 2.4-37 2.4-4 Mean Discharges in CFS of Columbia River Below Priest Rapids Dam, Modified to 1970 Conditions ................................ 2.4-38 2.4-5 Dependable Yield, Columbia River Below Priest Rapids Dam, Washington ....................................................................... 2.4-39 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF TABLES (Continued)

Number Title Page LDCN-05-050 2-x 2.4-6 Major Geologic Units in the Hanford Region and Their Water-Bearing Properties......................................................2.4-40

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES Number Title 2-xi 2.1-1 General Area, 0-20 Miles 2.1-2 General Area, 0-50 Miles 2.1-3 Overall Site Plan

2.1-4 Project Area Map - 10 Mile Radius

2.1-5 Project Area Map - 50 Mile Radius

2.1-6 2000 Population in Communities Around Site 2.1-7 Transportation and Topographic Features of Low Population Zone 2.2-1 Hanford Reservation Road System

2.2-2 Hanford Reservation Railroad System 2.2-3 Federal Airways and Instrument Approaches/Departures 2.3-1 Rainfall Intensity, Duration, and Frequency Based on the Period 1947-69 at Hanford 2.3-2 Greatest Depth of Snow on Ground During 24 of 25 Winters of Record at Hanford 1946-47 through 1969-70 2.3-3 Distribution of Characterized Tornadoes in 20-Year Period (1950-69) 2.3-4 Peak Wind Gust Return Probability Diagram 2.3-5 Dust Occurrences Per Wind Speeds to 400 ft Heights 2.3-6 Near-Surface Airborne Dust Concentration as a Function of Average Air Velocity COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES (Continued)

Number Title 2-xii 2.3-7 Monthly Hourly Average of Temperature and Relative Humidity (Sheets 1 through 3) 2.3-8 Probability (%) that the First Hourly Observation of an Inversion will Mark the Beginning of an Inversion Run of N Hr (Sheets 1 through 4) 2.3-9 Topographic Cross Sections of Region Surrounding Site 2.3-10 Yearly Hourly Average of Temperature and Relative Humidity 2.3-11 Cumulative (%) Frequency of Hourly Centerline /Q at Site Boundary Circular Distance of 1.212 Miles From Source (April 1974-March 1975) 2.3-12 Cumulative (%) Frequency of Hourly Centerline /Q at Site Boundary Circular Distance of 1.212 Miles From Source (April 1975-March 1976) 2.3-13 Cumulative (%) Frequency of Occurrence of /Q For Postulated Accidents of 8, 16, 72, and 624 Hr At Outer Boundary of LPZ (3.0 Miles from Source) (April 1974-March 1975) 2.3-14 Cumulative (%) Frequency of Occurrence of /Q for Postulated Accidents of 8, 16, 72, and 624 Hr at Outer Boundary of LPZ (3.0 Miles from Source) (April 1975-March 1976) 2.3-15 Annual Average /Q by Sector at the Site Boundary for First and Second Annual Cycle Data 2.4-1 Hydrographic Map

2.4-2 Topographic Map of Site and Surrounding Area

2.4-3 Detailed Contours Near the Site

2.4-4 Discharge and Temperature of the Columbia River at Priest Rapids 2.4-5 Columbia River Water Surface Profiles River Miles 323 to 358 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES (Continued)

Number Title LDCN-03-058 2-xiii 2.4-6 Safety-Related Building Roof Plans and Sections (Sheets 1 through 5) 2.4-7 PMF Hydrograph due to Thunderstorm PMP 2.4-8 Probable Maximum Precipitation Drainage Basin 2.4-9 Probable Maximum Precipitation Channel Cross Sections

2.4-10 Water Surface Profile

2.4-11 Effective Fetch Diagram

2.4-12 Computed Long-Term Temperature Trends on the Columbia River at Rock Island Dam (1938-1962) 2.4-13 River Elevation at Low Flows - River Mile 352

2.4-14 Duration Curves Columbia River, Priest Rapids Dam 2.4-15 Frequency Curves of High and Low Flows for the Columbia River Below Priest Rapids Dam 2.4-16 Location of Intake and Discharge 2.4-17 Monitoring Well Locations (September 1975) 2.4-18 Hanford Reservation Water Table Map (December 1975) 2.4-19 Groundwater Contours Assuming Construction of the Ben Franklin Dam 2.4-20 Hanford Reservation Water Table Map (January 1944) 2.4-21 Hydraulic Conductivities in the Unconfined Aquifer 2.4-22 Nitrate (NO3) Concentrations (December 1976)

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 Chapter 2 SITE CHARACTERISTICS LIST OF FIGURES (Continued)

Number Title LDCN-05-050 2-xiv 2.4-23 Gross Beta Concentrations (December 1976) 2.4-24 Tritium (3H) Concentrations (December 1976) 2.4-25 Pasco Basin Uppermost Confined Aquifer Potential Map (1970) 2.4-26 Hanford Reservation Water Table Map (September 1973) 2.4-27 Well Hydrographs (Sheets 1 and 2)

2.4-28 Site Topographic Map

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-03-023 2.1-1 Chapter 2

SITE CHARACTERISTICS

2.1 GEOGRAPHY AND DEMOGRAPHY 2.1.1 SITE LOCATION AND DESCRIPTION

2.1.1.1 Specification of Location Columbia Generating Station (CGS) is located in the southeast area of the U.S. Department of Energy's (DOE) Hanford Site in Benton County, Washington. The site is approximately 3 miles west of the Columbia River at River Mile 352, approximately 10 miles north of north Richland, 18 miles northwest of Pasco, and 21 miles northwest of Kennewick (Figures 2.1-1 and 2.1-2).

The reactor is located at 46° 28' 18" north latitude and 119° 19' 58" west longitude. The approximate Universal Transverse Mercator coordinates are 5,148,840 meters north and 320,930 meters east.

2.1.1.2 Site Area Map The CGS site area is that real estate over which Energy Northwest has the legal right to control access. It is the area enclosed by the exclusion area boundary plus the plant property lines as shown in Figure 3-1 of the Offsite Dose Calculation Manual (ODCM). The property line and nearby industrial facilities are shown in Figure 2.1-3. Industrial facilities located in the site area are the H. J. Ashe Substation and Energy Northwest's Nuclear Projects 1 and 4 (WNP-4 was terminated in January 1982, and WNP-1 was terminated in May 1994). Highway and railway facilities located within the site area are shown in Figure 2.1-3. The relative locations of the plant structures are shown in Figure 1.2-1.

The boundary of the exclusion area is a circle with its center at the reactor and a radius of 1950 m. Ownership and control of the land outside the CGS property line but within the site exclusion area are discussed in Section 2.1.2. The site is situated near the middle of the relatively flat, essentially featureless plain, which is best described as a shrub steppe with sagebrush interspersed with perennial native and introduced annual grasses extending in a northerly, westerly, and southerly direction for several miles. The plain is characterized by slight topographic relief of approximately 20 ft across the plant site.

The dominant topographic features in the area are the Rattlesnake Hills, 13 to 15 miles west southwest, 3200 ft above the elevation of the plant site; Gable Mountain, approximately COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-13-050 2.1-2 10 miles northwest of the site and about 670 ft above the site grade; and the steep river cut bluffs forming the east bank of the Columbia River, approximately 3.5 miles east of the site (Figure 2.1-1). 2.1.1.3 Boundaries for Establishing Effluent Release Limits The boundary for establishing effluent release limits (unrestricted area boundary as defined in 10 CFR Part 20) is the site area boundary as shown in the ODCM, Figure 3-1. The site area is the area enclosed by the exclusion area boundary and the plant property lines that fall outside the exclusion area. All area within the site area boundary is considered a controlled area as defined by 10 CFR 20.1003. A number of restricted areas (as defined in 10 CFR 20.1003) are associated with CGS. The primary CGS restricted area is located within the plant security fence which also is the boundary of the protected area (as defined in 10 CFR 73.2). This is shown as the double fence line in Figure 1.2-1. Unescorted access to the protected area is controlled by CGS security staff. Other restricted areas include the Independent Spent Fuel Storage Installation, stormwater ponds, Plant Support Facility calibration laboratory, Warehouse No. 5, the cooling tower sediment disposal area, and Building 167 on the WNP-4 site. Access to these secondary restricted areas is controlled by locks and fences. Temporary restricted areas may be established and removed as dictated by activities at CGS. 2.1.2 EXCLUSION AREA AUTHORITY AND CONTROL 2.1.2.1 Authority Energy Northwest leased 1089 acres from the DOE, within the DOE Hanford Site, to be used for CGS. A letter from the DOE Richland Operations office to the Managing Director of Energy Northwest (Reference 2.1-1) advises that the DOE has the authority to sell or lease land on the Hanford Site and the letter further states This Authority is contained in Section 120 of the Atomic Energy Community Act of 1955, as amended, and Section 161g of the Atomic Energy Act of 1954, as amended. There is also general federal disposal authority available under the Federal Property Administrative Services Act of 1949, as amended. The 1950-m radius exclusion area extends beyond the CGS property lines and overlaps DOE lands as well as the additional land leased by Energy Northwest for the construction of the WNP-1 and WNP-4 projects (see Figure 2.1-3 and ODCM Figure 3-1). All land outside the Energy Northwest leased property but within the exclusion area is managed by the DOE. In recognition of the requirement specified in 10 CFR 100.3(a) [Now 100.3] that a licensee have control over access to the exclusion area, the following terms have been incorporated as Article 7 of the site property lease agreement between Energy Northwest and the DOE (as modified in 1975):

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-11-027 2.1-3 Nothwithstanding any provisions of this lease to the contrary, the Administration [Energy Research and Development Administration -- now DOE] agrees that the Supply System [now Energy Northwest] has the authority to determine all activities within the exclusion area within the meaning of 10 CFR Section 100.3(a) [Now 100.3], including the authority to remove a personnel and property from the area. The Supply System agrees that it will exercise such authority in a manner so as not to preclude the Administration from undertaking any action or activity within the exclusion area that is permissible under the provisions of 10 CFR Section 100.3(a) [Now 100.3]. As used herein, the term "exclusion area" includes both the leased and nonleased portions of the exclusion area.

Therefore, any actions such as public access and actions concerning mineral rights and easements taken within the exclusion area but outside the leased property are under the control of the DOE with the provision that Energy Northwest has the legal right to control access of individuals to the exclusion area if necessary. All rail shipments on the track which traverses the property (Figure 2.1-3) are also under control of the DOE and are also subject to the above provision and controls imposed by Energy Northwest Security.

The only paved roads that traverse the exclusion area of CGS are the CGS, WNP-1, and WNP-4 facility access roads shown in Figure 2.1-3. Access by land from outside of the Hanford Site to the plant site is over DOE roads. Travel within the exclusion area on the access roads will be under the authority of Energy Northwest.

In the event that evacuation or other control of the exclusion area should become necessary, appropriate notice will be given to the DOE-Richland Operations Office for control of non-Energy Northwest originated activities.

The above provisions provide the necessary assurance that the exclusion area is properly controlled. If Energy Northwest should decide that an easement would be useful in ensuring continued control, there is a provision in Article 5(b) of the lease as follows: Subject to the provisions of Section 161g of the Atomic Energy Act of 1954, as amended, the Commission has authority to grant easements for rights-of-way for roads, transmission lines and for any other purpose, and agrees to negotiate with Energy Northwest for such rights-of-way over the Hanford Operations Area as are necessary to service the Leased Premises. Pursuant to this provision Energy Northwest could obtain an easement over the exclusion area in question from the DOE, which would ensure that no permanent structures or other activities inconsistent with the exclusion area would be carried on therein.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 LDCN-09-044 2.1-4 2.1.2.2 Control of Activities Unrelated to Plant Operation In accordance with, and as defined by 10 CFR 100.3, Energy Northwest has the authority to determine all activities within the exclusion area, including the authority to remove all personnel and property from the area. The following activities unrelated to plant operation are permitted within the exclusion area: 2.1.2.2.1 Industrial Development Complex Energy-Northwest is conducting site restoration and economic development (such as leasing of excess facilities for office space and manufacturing) activities at the WNP-1 and WNP-4 sites (the WNP-1 and WNP-4 sites are also leased from the DOE and controlled by Energy Northwest). The number of personnel at the WNP-1 and WNP-4 sites varies. However, coordination of activities within the exclusion area is under the control of Energy Northwest and the CGS emergency plan. This includes notification and evacuation considerations in the event of an emergency at CGS. 2.1.2.2.2 618-11 (Wye) Waste Burial Ground The 618-11 site is a DOE waste burial ground, encompassing an eight-acre parcel directly adjacent to Energy Northwest leased land (see Figure 2.1-3) and located wholly within the CGS exclusion area. The DOE and its site contractor are approved to perform non-intrusive surveillance and characterization activities to obtain data and information necessary for planning future intrusive activities and remediation strategies. These activities are necessary to meet the 618-11 site remediation and closeout milestone of September 2018 as delineated in the Hanford Federal Facility Agreement and Consent Order. All 618-11 site activities are controlled by DOE in accordance with 10 CFR Chapter III. DOE has responsibility for the 618-11 site documented safety analysis (DSA) in accordance with 10 CFR 830.204. The currently approved DSA and its associated technical safety requirements (TSR) establish the safety basis and assess the environmental impact of the non-intrusive activities within the site. The soil overburden covering the caissons and vertical pipe units at the 618-11 site is identified as a passive design feature that serves a mitigative function. Existing soil overburden shall not be removed. A memorandum of understanding (MOU) has been established between the DOE 618-11 site contractor and Energy Northwest for communication and mutual support for the non-intrusive activities at the site. The MOU delineates the requirements for the site contractor to inform Energy Northwest of plans, schedules, manning, and other matters pertaining to the non-intrusive site activities. In addition, the MOU defines Energy Northwest requirements for contractor notification of CGS events with the potential to affect the 618-11 site operation and/or personnel. Communication includes notification and evacuation considerations in the event of an emergency at CGS.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 LDCN-09-044 2.1-5 In the event of a 618-11 site emergency, including the 618-11 site design basis event, the 618-11 site is subject to control by the DOE. Control includes notifications, implementation of required actions, and communication of recommendations to protect the health and safety of CGS personnel and the public within and beyond the Hanford reservation boundaries. The non-intrusive activities, analyzed 618-11 site events, and the design basis event associated with the non-intrusive activities, have been assessed and approved by DOE. In addition, Energy Northwest has performed an evaluation of the 618-11 site releases that would occur from the postulated design basis event. The evaluation, using NRC radionuclide transport methodology and CGS meteorological data, has confirmed that the potential 618-11 site releases will not adversely impact Structures, Systems, and Components or credited operator actions. Implementation of DOE approved non-intrusive activities at the 618-11 site will not affect the operation of CGS, and thus, will not result in a significant hazard to the health and safety of the public from CGS's operation.

2.1.2.3 Arrangements for Traffic Control The only roads within the exclusion area are the Energy Northwest access roads. These roads are normally used only by employees and visitors associated with the CGS, WNP-1, and WNP-4 facilities, DOE, and DOE contractors. The security force, with offsite assistance as required, controls traffic during emergencies.

2.1.2.4 Abandonment or Relocation of Roads There were no public roads transversing the exclusion area that had to be abandoned or relocated as a result of the construction of CGS.

2.1.3 POPULATION DISTRIBUTION

Table 2.1-1 presents the compass sector population estimates for 1980 and the forecasts for the same compass sectors by decade from 1990 to 2030.* Cumulative totals are also shown in Table 2.1-1. This table may be keyed to Figures 2.1-4 and 2.1-5, which show the sectors and major population centers within 10 and 50 miles of the site. As can be seen in Figure 2.1-6, population centers, within 50 miles of the site include the Tri-Cities area of Richland, Pasco, and Kennewick; Moses Lake; Hermiston; and the communities lying along the Yakima River

• Population estimates out to 50 miles were derived to serve the licensing requirements of WNP-1, CGS, and WNP-4. Therefore, estimates were made relative to the centroid of the triangle formed by the three reactors. This point is located 2800 ft east of CGS and has coordinates longitude 119º 19' 18" west, latitude 46° 28' 19" north. This shift does not affect the overall accuracy or applicability of the population distribution projections.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-14-009,13-067 2.1-6 from Prosser to Toppenish. Figure 2.1-4 shows that there are no towns located within 10 miles of the site, with the exception of a small part of Richland.

The 1990 to 2030 forecasts presented here (Reference 2.1-2) are based on a. 1979 population figures provided by the Washington State Office of Financial Management,

b. Benton and Franklin County Traffic Analysis Zone population distributions,

c. Computed annual average area growth rates from 1975 through 1979 which were utilized to obtain the total 1980 population estimated for each area, and

d. County forecasts prepared by the Bonneville Power Administration. (References 2.1-3 and 2.1-4).

Table 2.1-2 presents the compass sector population estimates for 2010 based on U.S. Census Bureau data (Reference 2.1-5). See also Figures 2.1-4 and 2.1-5.

2.1.3.1 Population Within Ten Miles An estimated 3000 people live within 10 miles of the site. The nearest inhabitants occupy farms which are located east of Columbia River and are thinly spread over five compass sectors. There are no permanent inhabitants located within 3 miles of the site.

No significant changes in land use within five miles are anticipated. The Hanford Site is expected to remain dedicated primarily to industrial use without private residences. No change in the use of the land east of the Columbia River is expected since it currently is irrigated to about the maximum amount practicable. The primary increase in population within the 10-mile radius is expected to be in the area south and south-southeast of the plant (see Figure 2.1-4).

2.1.3.2 Population Between Ten and Fifty Miles As indicated in Table 2.1-2, about 450,000 people were estimated to be living within a 50-mile radius of CGS in 2010. Projections for the 10-50 mile region are shown in Table 2.1-1 which is based on earlier (1979-1980) population counts.

2.1.3.3 Transient Population The transient population consists of agricultural workers needed for harvesting crops produced in the region, industrial and construction workers, and sportsmen engaged in hunting, fishing, COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 2.1-7 and boating. A description of the transient population is discussed in Section 5.6 of the CGS Emergency Plan.

2.1.3.4 Low Population Zone The low population zone (LPZ) [see 10 CFR 100.3(b)] for CGS is defined as all land within a 3-mile radius of the reactor. This LPZ was selected on the basis that it is not expected to have a large population in the future and that effective protective measures could be established. As shown in Table 2.1-2, no permanent residents are located within a 3-mile radius of the reactor, and none are anticipated in the future.

There are no public facilities or institutions such as schools and hospitals within a 3-mile radius of the plant. The transportation facilities and topographic features of the LPZ are shown in Figure 2.1-7.

2.1.3.5 Population Center The nearest population center is the City of Richland, 12 miles to the south.

2.1.3.6 Population Density In 2000, the population densities within the 10, 20, and 30-mile radii were 9, 96, and 73 people per square miles, respectively. In 2030, the densities out to the same distances are estimated to be 13, 123, and 84, respectively, based on the projections in Table 2.1-1.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-14-009 2.1-8 2.

1.4 REFERENCES

2.1-1 Letter from Atomic Energy Commission, Richland Operations Office, to Managing Director of the Supply System, Washington Public Power Supply System,

Subject:

Appendix 2P, November 25, 1970.

2.1-2 Yandon, K. E., Projections and Distributions of Populations Within a 50-Mile Radius of Washington Public Power Supply System Nuclear Projects Nos. 1, 2, and 4 by Compass Direction and Radii Intervals, 1970-2030, October 1980.

2.1-3 Bonneville Power Administration, U.S. Department of Energy, Washington,

Subject:

Population, Employment and Household Projections to 2000 by County, July 1979.

2.1-4 Bonneville Power Administration, U.S. Department of Energy, Oregon Population, Employment and Household Projections to 2000 by County.

2.1-5 Washington State Office of Financial Management, Forecasting Division (2012). Small Area Estimate Program: Census Block Groups [SAEP_ColGenFac_Sectors_2000-2012.xls]. Via communication with M. Mohrman, Washington Office of Financial Management, July 2013; Oregon Population Data Estimates 2010 provided by Portland State University, Population Research Center, C. Rynerson, in collaboration with the M. Mohrman at Washington State Office of Financial Management, March 2014.

Table 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site 1980 1990 2000 2010 2020 2030 Distance Cumulative (miles) Direction (compass segment) Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003LDCN-03-023 2.1-90-3 All 0 0 0 0 0 0 0 0 0 0 0 0 3-5 N-NNE 0 0 0 0 0 0 0 0 0 0 0 0 NE 10 10 35 35 48 48 52 52 55 55 86 86 ENE 22 32 43 78 56 104 60 112 63 118 64 150 E 22 54 43 121 56 160 60 172 63 181 64 214 ESE 22 76 43 164 56 216 60 232 63 244 64 278 SE 4 80 6 170 9 225 11 243 11 255 12 290 SSE-NNW 0 80 0 170 0 225 0 243 0 255 0 290 5-10 N 26 106 58 228 77 302 83 326 87 342 88 378 NNE 83 189 126 354 152 454 162 488 170 512 172 550 NE 155 344 198 552 224 678 240 728 252 764 254 804 ENE 114 458 157 709 177 855 190 918 200 964 202 1006 E 135 593 200 909 257 1112 276 1194 290 1254 293 1299 ESE 168 761 276 1185 341 1453 366 1560 385 1639 389 1688 SE 190 951 406 1591 536 1989 575 2135 604 2243 610 2298 SSE 45 996 253 1844 308 2297 330 2465 347 2590 350 2648 S 50 1046 272 2116 483 2780 518 2983 544 3134 550 3198 SSW 235 1281 535 2651 809 3589 867 3850 911 4045 920 4118 SW 25 1306 25 2676 25 3614 27 3877 28 4073 29 4147 WSW-NNW 0 1306 0 2676 0 3614 0 3877 0 4073 0 4147 10-20 N 332 1638 371 3047 398 40112 427 4304 449 4522 454 4601 NNE 328 1966 371 3418 397 4409 426 4730 447 4969 452 5053 NE 399 2365 562 3980 588 4997 630 4360 662 5631 669 5722 ENE 792 3157 835 4815 855 5852 917 6277 964 6595 974 6696 E 461 3618 479 5294 544 6396 583 6860 613 7208 619 7315 ESE 192 3810 430 5724 576 6972 618 7478 650 7858 657 7972 SE 4155 7965 5221 10945 5821 12793 6242 13720 6561 14419 6627 14599 SSE 49178 57143 63483 74428 70917 83710 76043 89763 79932 94351 80734 95333 S 28943 86086 37672 112100 45434 129144 48717 138480 51208 145559 51722 147055 SSW 1592 87678 1772 113872 1922 131066 2061 140541 2166 147725 2188 149243 SW 3106 90784 3597 117469 894 134960 4175 144716 4389 152114 4433 153676 WSW 950 91734 1048 118517 1108 136068 1188 145904 1248 153362 1260 154936 W 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 WNW 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 NW 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 NNW 0 91734 0 118517 0 136068 0 145904 0 153362 0 154936 Table 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site (Continued) 1980 1990 2000 2010 2020 2030 Distance Cumulative (miles) Direction (compass segment) Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003LDCN-03-023 2.1-10 20-30 N 1501 93235 1837 120354 2055 138123 2203 148107 2316 155678 2339 157275 NNE 5759 98994 6487 126841 7123 145246 7638 155745 8029 163707 8110 165385 NE 2015 101009 2174 129015 2274 147520 2438 158183 2563 166270 2589 167974 ENE 1717 102726 1760 130775 1786 149306 1915 160098 2013 168283 2033 170007 E 151 102877 194 130969 220 149526 236 160334 248 168531 250 170257 ESE 153 103030 240 131209 305 149831 327 160661 344 168875 348 170605 SE 6138 109168 6512 137721 6738 156569 7225 167886 7594 176469 7670 178275 SSE 24116 133284 32559 170280 36360 192929 38987 206873 42032 218501 42454 220729 S 187 133471 678 170958 975 193904 1045 207918 1098 219599 1109 221838 SSW 875 134346 1218 172176 1426 195330 1529 209447 1607 221206 1623 223461 SW 6165 140511 7147 179323 7737 203067 8296 217743 8720 229926 8808 232269 WSW 1626 142137 1799 181122 1908 204975 2046 219789 2151 232077 2173 234442 W 1191 143328 1325 182447 1429 206404 1532 221321 1610 233687 1626 236068 WNW 185 143513 280 182727 297 206701 318 221639 334 234021 338 236406 NW 40 143553 44 182771 48 206749 51 221690 54 234075 55 236461 NNW 182 143735 200 182971 218 206967 234 221924 246 234321 249 236710 30-40 N 980 144715 1096 184065 1127 208094 1208 223132 1270 235591 1283 237993 NNE 3198 147913 3663 187728 3983 212077 4271 227403 4490 240081 4536 242529 NE 650 148563 800 188528 745 212822 799 228202 846 240927 850 243379 ENE 421 148984 447 188975 475 213297 509 228711 535 241462 540 243919 E 128 149112 136 189111 141 213438 152 228863 160 241622 162 244081 ESE 167 149279 176 189287 182 213620 195 229058 205 241827 208 244289 SE 464 149743 484 189771 497 214117 533 229591 560 242387 566 244855 SSE 592 150335 844 190615 955 215072 1023 230615 1076 243463 1087 245942 S 4680 155015 5653 196268 6368 221440 6828 237442 7172 250635 7250 253192 SSW 256 155271 424 196692 529 221969 567 238009 596 251231 602 253794 SW 473 155744 661 197353 786 222755 842 238851 885 252116 894 254688 WSW 21871 177615 24729 222082 26890 249645 28833 267684 30362 282478 30665 285353 W 3578 181193 3949 226031 4273 253918 4582 272266 4816 287294 4864 290217 WNW 1399 182592 1459 227490 1579 255497 1693 273959 1780 289074 1798 292015 NW 703 183295 770 228260 836 256333 896 274855 942 290016 952 292967 NNW 1575 184870 1738 229998 1899 258232 2036 276891 2140 292156 2161 295128 40-50 N 17872 202742 19730 249728 21572 279804 23130 300021 24312 316468 24556 319684 NNE 893 203635 1019 250747 1121 280925 1202 301223 1263 317731 1275 320959 NE 926 204561 1139 251886 1275 282200 1367 302590 1437 319168 1451 322410 ENE 213 204774 243 252129 375 282575 402 302992 423 319591 427 322837 E 241 205015 258 252387 268 282843 287 303279 302 319893 305 323142 ESE 864 205879 925 253312 961 283804 1030 304309 1083 320976 1095 324237 Table 2.1-1 Projected Population Distribution by Compass Sector and Distance from the Site (Continued) 1980 1990 2000 2010 2020 2030 Distance Cumulative (miles) Direction (compass segment) Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total Number Cumulative Total COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003LDCN-03-023 2.1-11 40-50 (cont.) SE 2084 207963 2245 25557 2349 286153 2518 306827 2646 323622 2673 326910 SSE 1740 209703 1920 257477 2072 288225 2222 309049 2336 325958 2359 329269 S 16540 226243 16406 273883 17708 305933 18987 328036 19958 345916 20158 349427 SSW 2610 228853 2895 276778 2972 308905 3186 331222 3349 349265 3428 352855 SW 421 229274 443 277221 476 309381 509 331731 535 349800 541 353396 WSW 809 230083 892 278113 965 310346 1035 332766 1088 350888 1099 354495 W 18515 248598 20481 298594 22176 332525 23780 356546 24996 375884 25247 379742 WNW 1742 250340 1903 300497 2043 334568 2191 358737 2303 378187 2326 382068 NW 812 251152 859 301356 905 335473 970 359707 1020 379207 1030 383098 NNW 532 251684 587 301943 642 336115 688 360395 723 379930 730 383828

Table 2.1-2 2010 Population Distribution by Compass Sector and Distance from the Site LDCN-14-009,13-067 2.1-12 COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 Distance (miles) Direction (compass segment) 2010 Population Distance (miles) Direction (compass segment) 2010 Population Distance (miles) Direction (compass segment) 2010 Population 0-3 ALL 0 5-10 N 16 10-20 N 136 5-10 NNE 78 10-20 NNE 742 3-4 NNE 0 5-10 NE 248 10-20 NE 1699 3-4 ENE 0 5-10 ENE 213 10-20 ENE 934 3-4 E 1 5-10 E 298 10-20 E 680 3-4 ESE 0 5-10 ESE 308 10-20 ESE 513 3-4 SE-NNW 0 5-10 SE 588 10-20 SE 16219 5-10 SSE 239 10-20 SSE 95379 4-5 NNE 1 5-10 S 376 10-20 S 38669 4-5 NE 18 5-10 SSW 548 10-20 SSW 7516 4-5 ENE 19 5-10 SW 16 10-20 SW 1232 4-5 E 27 5-10 WSW-NW 0 10-20 WSW 11 4-5 ESE 25 5-10 NNW 1 10-20 WNW 0 4-5 SE 0 10-20 NNW 1 4-5 SSE-NNW 0 10-20 NW - W 0 0-5 TOTAL 91 0-10 TOTAL 3020 0-20 TOTAL 166751 20-30 N 1098 30-40 N 1138 40-50 N 37171 20-30 NNE 13285 30-40 NNE 3802 40-50 NNE 782 20-30 NE 1237 30-40 NE 210 40-50 NE 705 20-30 ENE 3638 30-40 ENE 302 40-50 ENE 164 20-30 E 53 30-40 E 121 40-50 E 48 20-30 ESE 509 30-40 ESE 686 40-50 ESE 188 20-30 SE 18611 30-40 SE 343 40-50 SE 1415 20-30 SSE 50050 30-40 SSE 201 40-50 SSE 310 20-30 S 1710 30-40 S 8330 40-50 S 30053 20-30 SSW 131 30-40 SSW 236 40-50 SSW 5441 20-30 SW 11225 30-40 SW 1552 40-50 SW 217 20-30 WSW 1475 30-40 WSW 41107 40-50 WSW 4428 20-30 W 50 30-40 W 934 40-50 W 22691 20-30 WNW 205 30-40 WNW 6111 40-50 WNW 26 20-30 NW 611 30-40 NW 2478 40-50 NW 619 20-30 NNW 443 30-40 NNW 3870 40-50 NNW 1622 0-30 TOTAL 271082 0-40 TOTAL 342503 0-50 TOTAL 448383 Table based on April 2010 Census Bureau counts.

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ParkWTSNAKE RIVERL A K E W A L L U L AUNION PACIFICUNION PACIFICHedgesWTSubstaGrain elevatorGravelpitRadio TowersRadioTowerGrain elevatorWilliams WellsAmon WellYoungWellsCoyoteSpring14Bowden SpringsBofer CanyonTaylor CanyonFour CanyonStraub CanyonVistaCressWellsColumbia CanalKENNEWICKFranklin Co Irr Can NORTHERNBURLINGTON NORTHERNColumbia CanalBADGER MOUNTAINCanalSwitzler CanyonPipelineHORSE HEAVEN HILLSDry CreekWalla Walla RiverWHITMANMISSIONNHSWalla Walla RiverIslandViewRichland391124260McNary DamL A K E W A L L U L AWASHINGTONOREGONSESGardenaWindmillBig WellCold SpringsReservoirHunt DitchGreasewood CreekPine Dry CrBurlingame DitchTo Pendleton3957307303084Umatilla River20732SSEMilton-FreewaterWalla Walla ValleyUmapineWalla Walla RiverSkyranch 850Page 850204WestonAthena1111Grain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorWTWTBowlusHillGrain elevatorOregon Sky Ranch357Grain elevatorHoldmanWTNORTH FORK JUNIPER CANYONNORTH FORK COLD 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RIDGEWindmillRanchWindmillRanchCemeteryClevelandBickletonCemeterySTEGEMAN CANYONSWBIG HORN CANYONWOOD GULCHDOUTY CANYONAlder CreekPine CreekSPRING CANYONCrowButte221Grain elevatorGrain elevatorGrain elevatorGravelpit2402242412232222RanchH O R S E H E A V E N H I L L SCemRanchGrain elevatorRanchGrain elevatorRanchRadioTowerGravelpitGravelpitRanchGrain elevatorCarter CanyonGrain elevGrain elevatorGrain elevatorGrain elevatorGrain elevatorRanchBadger CanyonBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksKelly GulchHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandIowa FlatsRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONGibbonWhitstrandChandler ButteSunnyside CanalChaffeePumpingStationRanchRanchRoza CanalYAKIMA RIVERUNION PACIFICHORSE HEAVEN HILLSProsser694GRANDVIEW BUTTEPumpingStationSunnyside764LichtySunnysideBryonRanchPumping StationPumping StationToppenishBuenaOutlookEmeraldGrangerGiffen LakeTOPPENISHNWRWSWYakima I R HdqrsNORTHERNBURLINGTONGranger Farm Labor CampPumpingStationTOPPENISH NWRSNIPES MOUNTAINBURLINGTONHEMBRE MTNSatusMabtonWTCemPumping StationSulfur SpringWaterTanksRadioTowerLibertyOleys LakeGrangeMabton West CanalYakimaIndian ReservationGrain elevatorBluelightWindmillGrain elevatorRadio StationRadio TowerMoore CanyonCoyote CanyonGravelpitProsserpit9797LozierSpringsCampbellSpringMaidenSpringSpringWebber CanyonMabton SiphonToppenish CreekToppenish CreekWapity SloughSatus No. 2 Pump CanalSunnyside CanalZillahRoza CanalSulfur CrBlack CanyonSpring CrSnipes CreekWater410PipelineEast Branch Glade CrMcKinleySpringGlade CreekGlade CreekWNWW242424324RanchRanchRange CentralCemObservation postBadger GapSquaw TitFiring Center AAFY A K I M A R I D G EU M T A N U M R I D G EY A K I M AF I R I N GC E N T E RSADDLE MOUNTAINSSADDLE MOUNTAINSCORRAL CANYONSOURDOUGH CANYONALKALI CANYONSADDLE MOUNTAINSNWNNEW A H L U K E S L O P ERanchPriest RapidsDamMattawaChristensen Bros840SMYRNA BENCHCNWRCNWRCNWRBeverlyRanchWAHATISPEAKMattawa750Desert570CorfuRanchROYAL SLOPEWaterTankCNWRCNWRCNWRSchwanaWhite BluffsSADDLE MOUNTAINNATIONAL WILDLIFE REFUGECABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsLower Crab CreekWTCNWRCold CreekHanford DitchTowersRanchRanchWaterTankCOLD CREEK VALLEYBensonSpringLockeIslandDry CrHorsethief PtCairn Hope PeakEmerson NippleSubstaH A N F O R D R E S E R V A T I O NWapatoSawyerDonaldPumping stationELEPHANT MOUNTAINHILLSZILLAH PEAKMOXEE VALLEYMoxee CityRATTLESNAKE HILLSRanchTowerPlantQuarantineStationBLACK ROCK VALLEYRanchRanchCemHigh TopR A T T L E S N A K E H I L L SR A T T L E S N A K E H I L L SRadioFacilityKITTITAS CANYONMoxee CanalMoxee CanalSelah CreekHanson CreekMcDonald SpringsCottonwood CreekBlack Rock SpringSentinel GapSentinel BluffsELECTRIFIEDSmyrnaSENTINEL MOUNTAINCemPriest RapidsLakeNNWSAND DUNESWHISKEY DICKMTNROCKY COULEESPRING GULCHCaribou CreekRYEGRASS COULEE PARKMIDDLE CANYONHULT BUTTEJOHNSON CANYONBOYLSTON MOUNTAINSRock SpringPoison SpringLone Star SpringRYEGRASSMOUNTAINWippe Pumping StationBadger CrFire stationKittitas Microwave TowerSCHNEBLY COULEEF R E N C H M A N H I L L SWinchester WastewayMoses Lake Sky Ranch1100GeorgeSAND HILLSPotholesState ParkTHE POTHOLES10Mae10Ranch909026CNWRChristensen1150F R E N C H M A N H I L L SCemCampRoyalCityNATURAL CORRALLARSON AFBIMPACT AREARed RockCouleeCNWRWest CanalFrenchman Hills LakeRoyal LakeWanapum DamCNWRFrenchman SpringsPOTHOLES COULEEBABCOCK BENCHLAVAGINKGOPETRIFIEDFOREST PARKSand HollowBABCOCK RIDGEStan CoffinLakeCRESCENT BARCRESCENT BAR281283Leslie CreekSkookumchuck CreekJohnson CrBoylstonBADGER POCKETEast KittitasAirway BeaconTrail CreekNorth Branch CanalBeaconHIAWATHA VALLEYSAND DUNES17171090Larson Air Force Base1186Moses LakePOTHOLES RESERVOIRMoses Lake12002121261261RitzvilleRitzville180021395NNELindDewald1880WardenWaterFranz RanchSchrag StationLaingStationRefineryWheelerRaugust StationWindmillLIND COULEERadioTowerDryland ExperimentProvidenceGrain elevatorsGrain elevatorsLind1491ServiaLIND COULEEBOWERS COULEELIND COULEEPipelineNew Warden1265GrainelevatorGravel pitPipelineNORTHERN PACIFICUndergroundaqueductCHICAGO MILWAUKEE ST PAUL AND PACIFICFARRIER COULEEWindmillWindmillPAHA COULEEPahaNORTHERN PACIFIC1090RalstonMcElroy LakePizarroGrainelevROCKY COULEEUndergroundaqueductLewis HornPelican HornLIND COULEEBassett JunctionMcDonald SidingWindmillTiflisRitellSidingNORTHERN PACIFICCHICAGO MILWAUKEE ST PAUL AND PACIFICRocky Coulee WastewayO'Sullivan DamSielen SidingUpper GooseLakeJACKASSMOUNTAINParkerHornSoda LakeCOLUMBIANATIONALWILDLIFE REFUGEGoose LakeShiner LakeMorgan LakeTaggars1149Kent Farms1155BeatriceGravel pitRoxboroWEBER COULEEMeterStationHillcrestRuffKITTITAS CO GRANT COADAMS COBENTON COFRANKLIN COYAKIMA COKLICKITAT COWALLA WALLA COUMATILLA COMORROW CO82Plymouth8212828212CemGrandviewDamNorthProsser82BURLINGTON121282KionaGravelpit18218212ChandlerIslandViewSacajaweaState ParkSixprong CreekSudburyRoute 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonwoodIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.46°00'46°30'46°45'46°15'45°45'47°00'LongitudeLatitude46°00'46°30'46°45'46°15'47°00'LatitudeLongitude119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'123953953953953030General Area, 0 - 50 Miles990306.602.1-2Form No. 960690Amendment 55May 2001FigureDraw. No.Rev.60 Miles50 MilesPendleton149337Grain elevatorSTAGE GULCHMISSOURI GULCHRailroadPipelinePowerlineMedium Duty RoadLight Duty RoadHeavy Duty RoadLEGEND395260Landplane AirportLanding AreaFederal Route MarkerState RouteInterstate Route80NPark or ReservationBoundarySandpit or GravelpitPopulated PlacesRadio Tower, WellLatitude/Longitude930114.50 MiAug 1998SCALE20 Statute Miles151050530 Kilometers2515105052045°45'Brushy CreekColumbia Generating Station50 Mile Ingestion ExposureEmergency Planning ZoneNColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Project Area Map - 10 Mile Radius4-1.201.603099FigureForm No. 960690.veR.oN .warDEltopiaRanchWaterTankBasin City770170RanchSavageIslandBasin CityRanchRanchUS Government RRMathewsCornerRINGOLD FLATCampLakeClarkPondRadioTowerGravelpitGladePascoJACKASSMOUNTAINWaterTankWooded IslandESQUATZEL COULEEDiversionChannelEsquatzelRichlandPasco WestVista521ColumbiaPointTri-CitiesAirport407Potholes CanalWT395SacajaweaState ParkWTSubsta14VistaKENNEWICKFranklin Co Irr Can NORTHERNColumbia CanalBADGER MOUNTAINIslandViewRichland391Grain elevator240224Grain elevatorGrain elevatorBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONChandler ButteChaffeeRoza CanalWebber CanyonWhite BluffsCABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsHanford DitchTowersBENTON CO82121282KionaGravelpit18218212ChandlerIslandViewSacajaweaState ParkRoute 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.StevensCountryChristianCountry HavenEdwin MarkumBig RiverCOLD CREEK VALLEYH A N F O R D R E S E R V A T I O NYAKIMA RIVERIowa FlatsN Power Plant LoopColumbia Generating StationKinder-CareKiBewoodScale in Miles105055 MILES20 MILESFFTFCanal10 MILESColumbia Generating StationFinal Safety Analysis Report Hepner JunctionPine CreekpitpitSandpitEltopiaRanchWaterTankWater Tank1726026026261260Gravel pit17FiveCorners395395Hathaway800Pent884Watson1349Baumann Farm1600Othello1145Basin City770170RanchSavageIslandBasin CityRanchRanchLower Monumental DamPleasantViewFarmFIELDS GULCHAyerRanchPALOUSE FALLSRECREATION AREAFarmHarderDUNNIGAN COULEEDavinSkookumCan261Grain ElevatorGrain ElevatorOld RR gradeConnellConnell City925Grain ElevatorWASHTUCNA COULEERattlesnakeCanCOULEEHARDESTYMichigan PrairieWashtucnaKahlotusSAND HILLS COULEEHattonHATTON COULEEENEER A T T L E S N A K E F L A TCunningham CanyonPROVIDENCE COULEEPipelineGrain ElevatorCunninghamFrischnechtShanoBruceBURLINGTONNORTHERNRadioTowerRadio TowerMesaDevils CanyonSMITH CANYONOLD MAID COULEEWaterTankOthelloAir Force StaCactusOthelloELECTRIFIEDTauntonSaddle GapPotholesEastCanalUS Government RRRanchBURLINGTON NORTHERNUNION PACIFICLower Monumental813FarringtonpitScottMagallonMathewsCornerRINGOLD FLATFisher Ranch152110 MI20 MI30 MI40 MI50 MI260RattlesnakeLakeCampLakeScooteneyReservoirT LakeWASHTUCNA COULEEClarkPondLake KahlotusSulfur LakeP A R A D I S E F L A T SLowCanalEagleLakesDry LakeESEPrescottHarshaLamarEuricaGrain elevatorGrain elevatorElwoodClydeGrainelevatorHatchGrainelevatorGrainelevatorGrain elevatorGrainelevatorGrainelevatorGrain elevatorGrainelevatorHadleyWalkerPageValleyGroveEnnisGrainelevatorGrain elevatorGrainelevatorWhitman StationSubstaSubstaCollegePlaceWALLA WALLALowdenTouchetMartinSlaterPipeline12395ZangerJunctionReeseClimaxSidingGrain elevatorSURVIVAL TRAINING AREAJUNIPER FORESTWaterTankGravelpitGravelpitReddLeveyWaterTankGrain elevatorGrain elevatorJOHNSONBUTTEThe ButteRadioTowerRadioTowerWallulaWaterTankHumoristMCNARY NATIONALWILDLIFE REFUGENine Mile CanyonCompressorStation540Snake River12QuarryWalker CanyonRYE GRASS FLATEELUOC SSARG EYRWaterTankQuarry124Lake SacajaweaGravelpitGladePascoSubstaSubstaIce Harbor DamJACKASSMOUNTAINWaterTankWooded IslandTaylor FlatESQUATZEL COULEEDiversionChannelEsquatzelRichlandPasco WestVista521ColumbiaPointTri-CitiesAirport407Potholes CanalWTPipelineDry HollowE U R E K A F L A TWinnett CanyonWinnett CanyonBadger HollowBadger HollowGravelpitBURLINGTON NORTHERNBURLINGTON NORTHERNSPRING VALLEYWebber CanyonWoodward CanyonBurbankFinleyNine Canyon395SacajaweaState ParkWTSNAKE RIVERL A K E W A L L U L AUNION PACIFICUNION PACIFICHedgesWTSubstaGrain elevatorGravelpitRadio TowersRadioTowerGrain elevatorWilliams WellsAmon WellYoungWellsCoyoteSpring14Bowden SpringsBofer CanyonTaylor CanyonFour CanyonStraub CanyonVistaCressWellsColumbia CanalKENNEWICKFranklin Co Irr Can NORTHERNBURLINGTON NORTHERNColumbia CanalBADGER MOUNTAINCanalSwitzler CanyonPipelineHORSE HEAVEN HILLSDry CreekWalla Walla RiverWHITMANMISSIONNHSWalla Walla RiverIslandViewRichland391124260McNary DamL A K E W A L L U L AWASHINGTONOREGONSESGardenaWindmillBig WellCold SpringsReservoirHunt DitchGreasewood CreekPine Dry CrBurlingame DitchTo Pendleton395730730Pendleton14933084Umatilla River20732SSE37Milton-FreewaterWalla Walla ValleyUmapineWalla Walla RiverSkyranch 850Page 850204WestonAthena1111Grain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorGrain elevatorWTWTBowlusHillGrain elevatorOregon Sky Ranch357Grain elevatorHoldmanWTNORTH FORK JUNIPER CANYONNORTH FORK COLD SPRINGS CANYONSOUTH FORK JUNIPER CANYONMIDDLE FORK COLD SPRINGS CANYONSOUTH FORK COLD SPRINGS CANYONCOLD SPRINGS CANYONDESPAIN GULCHSTAGE GULCHJUNIPER CANYONRUSH CANYONSwitzler CanyonTankBURLINGTON NORTHERNWARM SPRINGS CANYONVANSYCLE CANYONSTAGE GULCHMISSOURI GULCHGrain elevator37FOURMILE GAPEchoHAT ROCKSTATE PARKUMATILLA BUTTEHermiston StateStanfieldHinkleSILLUSI BUTTEHERMISTON BUTTEHermistonMcNaryPower CitySubstationHERMISTON BUTTEUNION PACIFIC207COLD SPRINGSNWR84221SSW1414BOARDMANBOMBINGRANGE730SCALE20 Statute Miles151050530 Kilometers25151050520LAKE UMATILLAUMATILLA NATIONAL WILDLIFE REFUGECOLUMBIA RIVERHepner JunctionGOLGOTHA BUTTE84CANOE RIDGEALDER RIDGEALDER RIDGEWindmillWindmillBoardman390PATERSONDEAD CANYONTULE CANYONRattlesnakeSpringRanchRanchOrdnanceWater towerUmatilla Army DepotRIDGEUMATILLA ORDNANCEDEPOTWestlandWest Extension Irrigation CanalDisposal PlantIrrigonUNION PACIFICWaterTowerBURLINGTONPatersonFOURMILE CANYONWARDBUTTEFINLEY BUTTESBING CANYONEast BranchGlade CreekCOYOTE COULEEBoardmanCoyote CanyonSAND RIDGEWindmillRanchWindmillRanchCemeteryClevelandBickletonCemeterySTEGEMAN CANYONSWBIG HORN CANYONWOOD GULCHDOUTY CANYONAlder CreekPine CreekSPRING CANYONCrowButte221Grain elevatorGrain elevatorGrain elevatorGravelpit2402242412232222RanchH O R S E H E A V E N H I L L SCemRanchGrain elevatorRanchGrain elevatorRanchRadioTowerGravelpitGravelpitRanchGrain elevatorCarter CanyonGrain elevGrain elevatorGrain elevatorGrain elevatorGrain elevatorRanchBadger CanyonBadgerCandy Mtn.Fast Flux Test FacilityRATTLESNAKE HILLSWaterTankWaterTanksKelly GulchHorn Rapids DamWTCorral CanyonWTRadioTowerObservatoryPumping StationMcWhorter1356WestRichlandIowa FlatsRED MOUNTAINGoose HillUNION PACIFICBenton CityBURLINGTONGibbonWhitstrandChandler ButteSunnyside CanalChaffeePumpingStationRanchRanchRoza CanalYAKIMA RIVERUNION PACIFICHORSE HEAVEN HILLSProsser694GRANDVIEW BUTTEPumpingStationSunnyside764LichtySunnysideBryonRanchPumping StationPumping StationToppenishBuenaOutlookEmeraldGrangerGiffen LakeTOPPENISHNWRWSWYakima I R HdqrsNORTHERNBURLINGTONGranger Farm Labor CampPumpingStationTOPPENISH NWRSNIPES MOUNTAINBURLINGTONHEMBRE MTNSatusMabtonWTCemPumping StationSulfur SpringWaterTanksRadioTowerLibertyOleys LakeGrangeMabton West CanalYakimaIndian ReservationGrain elevatorBluelightWindmillGrain elevatorRadio StationRadio TowerMoore CanyonCoyote CanyonGravelpitProsserpit9797LozierSpringsCampbellSpringMaidenSpringSpringWebber CanyonMabton SiphonToppenish CreekToppenish CreekWapity SloughSatus No. 2 Pump CanalSunnyside CanalZillahRoza CanalSulfur CrBlack CanyonSpring CrSnipes CreekWater410PipelineEast Branch Glade CrMcKinleySpringGlade CreekGlade CreekWNWW242424324RanchRanchRange CentralCemObservation postBadger GapSquaw TitFiring Center AAFY A K I M A R I D G EU M T A N U M R I D G EY A K I M AF I R I N GC E N T E RSADDLE MOUNTAINSSADDLE MOUNTAINSCORRAL CANYONSOURDOUGH CANYONALKALI CANYONSADDLE MOUNTAINSNWNNEW A H L U K E S L O P ERanchPriest RapidsDamMattawaChristensen Bros840SMYRNA BENCHCNWRCNWRCNWRBeverlyRanchWAHATISPEAKMattawa750Desert570CorfuRanchROYAL SLOPEWaterTankCNWRCNWRCNWRSchwanaWhite BluffsSADDLE MOUNTAINNATIONAL WILDLIFE REFUGECABLE BUTTEHanfordCABLE MOUNTAINCoyote RapidsLower Crab CreekWTCNWRCold CreekHanford DitchTowersRanchRanchWaterTankCOLD CREEK VALLEYBensonSpringLockeIslandDry CrHorsethief PtCairn Hope PeakEmerson NippleSubstaH A N F O R D R E S E R V A T I O NWapatoSawyerDonaldPumping stationELEPHANT MOUNTAINHILLSZILLAH PEAKMOXEE VALLEYMoxee CityRATTLESNAKE HILLSRanchTowerPlantQuarantineStationBLACK ROCK VALLEYRanchRanchCemHigh TopR A T T L E S N A K E H I L L SR A T T L E S N A K E H I L L SRadioFacilityKITTITAS CANYONMoxee CanalMoxee CanalSelah CreekHanson CreekMcDonald SpringsCottonwood CreekBlack Rock SpringSentinel GapSentinel BluffsELECTRIFIEDSmyrnaSENTINEL MOUNTAINCemPriest RapidsLakeNNWSAND DUNESWHISKEY DICKMTNROCKY COULEESPRING GULCHCaribou CreekRYEGRASS COULEE PARKMIDDLE CANYONHULT BUTTEJOHNSON CANYONBOYLSTON MOUNTAINSRock SpringPoison SpringLone Star SpringRYEGRASSMOUNTAINWippe Pumping StationBadger CrFire stationKittitas Microwave TowerSCHNEBLY COULEEF R E N C H M A N H I L L SWinchester WastewayMoses Lake Sky Ranch1100GeorgeSAND HILLSPotholesState ParkTHE POTHOLES10Mae10Ranch909026CNWRChristensen1150F R E N C H M A N H I L L SCemCampRoyalCityNATURAL CORRALLARSON AFBIMPACT AREARed RockCouleeCNWRWest CanalFrenchman Hills LakeRoyal LakeWanapum DamCNWRFrenchman SpringsPOTHOLES COULEEBABCOCK BENCHLAVAGINKGOPETRIFIEDFOREST PARKSand HollowBABCOCK RIDGEStan CoffinLakeCRESCENT BARCRESCENT BAR281283Brushy CreekLeslie CreekSkookumchuck CreekJohnson CrBoylstonBADGER POCKETEast KittitasAirway BeaconTrail CreekNorth Branch CanalBeaconHIAWATHA VALLEYSAND DUNES17171090Larson Air Force Base1186Moses LakePOTHOLES RESERVOIRMoses Lake12002121261261RitzvilleRitzville180021395NNELindDewald1880WardenWaterFranz RanchSchrag StationLaingStationRefineryWheelerRaugust StationWindmillLIND COULEERadioTowerDryland ExperimentProvidenceGrain elevatorsGrain elevatorsLind1491ServiaLIND COULEEBOWERS COULEELIND COULEEPipelineNew Warden1265GrainelevatorGravel pitPipelineNORTHERN PACIFICUndergroundaqueductCHICAGO MILWAUKEE ST PAUL AND PACIFICFARRIER COULEEWindmillWindmillPAHA COULEEPahaNORTHERN PACIFIC1090RalstonMcElroy LakePizarroGrainelevROCKY COULEEUndergroundaqueductLewis HornPelican HornLIND COULEEBassett JunctionMcDonald SidingWindmillTiflisRitellSidingNORTHERN PACIFICCHICAGO MILWAUKEE ST PAUL AND PACIFICRocky Coulee WastewayO'Sullivan DamSielen SidingUpper GooseLakeJACKASSMOUNTAINParkerHornSoda LakeCOLUMBIANATIONALWILDLIFE REFUGEGoose LakeShiner LakeMorgan LakeTaggars1149Kent Farms1155BeatriceGravel pitRoxboroWEBER COULEEMeterStationHillcrestRuffKITTITAS CO GRANT COADAMS COBENTON COFRANKLIN COYAKIMA COKLICKITAT COWALLA WALLA COUMATILLA COMORROW CORailroadPipelinePowerlineMedium Duty RoadLight Duty RoadHeavy Duty RoadLEGEND395260Landplane AirportLanding AreaFederal Route MarkerState RouteInterstate Route80NPark or ReservationBoundarySandpit or GravelpitPopulated PlacesRadio Tower, WellLatitude/Longitude82Plymouth8212828212CemGrandviewDamNorthProsser82BURLINGTON121282KionaGravelpit18218212ChandlerColumbia Generating Station50 Mile Ingestion ExposureEmergency Planning ZoneNIslandViewSacajaweaState ParkSixprong CreekSudbury930114.50 MiAug 1998Route 4 SouthRoute 4 SouthRoute 11ABasin Hill Rd.Hollingsworth Rd.Bellflower Rd.Columbia Rd.Mountain Vista RdRoute 10 SouthRoute 2 SouthHorn Rapids Rd.Stevens Dr.Selph Landing Rd.Taylor Flats Rd.Glade North Rd.Alder RdBirch Rd.W. Sagemoor Rd.CedarDogwoodElm Rd.West Fir Rd.Eltopia Rd.Fir Rd.Fir WayGlenwoodGlenwoodAuburn Rd.N. Belleview Rd.N. Belleview Rd.N. Coulee Rd.CootonwoodIronwood Rd.W. Juniper Rd.Russell Rd.W. Klamath Rd.Sheffield Rd.Juniper Rd.Olympia Dr.Glade North Rd.AshR 170HarringtonVanGiesonGeorge Washinton WayN. Rd 68W. Sagemoor Rd.46°00'46°30'46°45'46°15'45°45'47°00'LongitudeLatitude46°00'46°30'46°45'46°15'45°45'47°00'LatitudeLongitude119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'119°00'118°45'118°30'119°30'120°00'119°45'119°15'120°15'123953953953953030Project Area Map - 50 Mile Radius990306.502.1-5Form No. 960690Amendment 55May 2001FigureDraw. No.Rev.ColumbiaGeneratingStationColumbia Generating StationFinal Safety Analysis Report 2010 Population in Communities Around Site970187.1412.1-6FigureAmendment 63December 2015Form No. 960690Draw. No.Rev.Ephrata(7,664)Quincy (6,750)Royal City (2,140)Moses Lake (20,366)Odessa (910)Ritzville (1,673)Lind (564)Mesa (489)Connell (4,209)Kahlotus (193)Dayton (2,526)Prescott (318)Waitsburg (1,217)Walla Walla (31,731)College Place (8,765)Milton Freewater (7,050)Stanfield (2,043)Boardman(3,220)Hermiston (16,745)Union Gap (6,047)Wapato (4,997)Toppenish (8,949)Granger (3,246)Yakima (91,196)Moxee (3,308)Zillah (2,964)Mabton(2,286)Prosser (5,714)Benton City (3,038)Columbia Generating StationIrrigon(1,826)Umatilla(6,906)Pendleton (16,612)Scale01020304050 MilesColumbia RiverYakima RiverSnake RiverColumbia RiverEllensburg (18,174)MorrowKlickitatYakimaKittitasGrantAdamsFranklinWalla WallaUmatillaBentonRichland (48,058)West Richland (11,811)Kennewick (73,917)George (501)Selah (7,147)Mattawa (4,437)Othello (7,364)Warden (2,692)Sunnyside (15,858)Grandview10,862)Columbia Generating StationFinal Safety Analysis ReportLDCN-14-009, 13-067Pasco (59,781)

COLUMBIA GENERATING STATION Amendment 60 FINAL SAFETY ANALYSIS REPORT December 2009 LDCN-08-035 2.2-1 2.2 NEARBY INDUSTRIAL, TRANSPORTATION, AND MILITARY FACILITIES This section describes the industrial, transportation, and military installations and operations in the vicinity of the site which may have a potential effect on the safe operation of Columbia Generating Station (CGS).

2.2.1 LOCATION AND ROUTES

There are no military bases, missile sites, manufacturing plants, chemical plants, commercial chemical storage facilities, or airports within a 5-mile radius of the site. A security barrier completely surrounds the station and its major supporting facilities to keep unauthorized vehicles a safe distance from critical structures.

According to the Richland Operations Office of the Department of Energy (DOE) (Reference 2.2-1), there are no plans for petrochemical storage facilities, airports, oil and gas pipelines, or petrochemical tank farms on the Hanford Site. Plans for modifications to or new radiological material treatment or storage facilities are discussed in Section 2.2.2.

As shown in Figure 2.1-3, the following facilities are located at or near the CGS site: Energy Northwest Plant Engineering Center, H. J. Ashe Substation, DOE Fast Flux Test Facility (FFTF), WNP-1 and WNP-4 sites, DOE 618-11 (Wye) radioactive waste burial ground, Permanent meteorological tower, Independent Spent Fuel Storage Installation (ISFSI), and Hydrogen Storage and Supply Facility. Other facilities that are located within a 5-mile radius of the site include: The Plant Support Facility/Emergency Operation Facility which is located 0.75 miles southwest of CGS on Energy Northwest property, The Benton Substation which is located 3 miles east-southeast of CGS on DOE property, The Laser Interferometer Gravitational-Wave Observatory (LIGO) which is located approximately 3.3 miles west-southwest of CGS on DOE property, and The DOE 618-10 (300 North) radioactive waste burial ground which is located approximately 3.5 miles south of CGS on DOE property.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-01-055,03-023 2.2-2 Transportation needs of CGS can be met by existing barge, rail, and highway facilities. Barges of up to 3000 tons capacity can be accommodated on the Columbia River within the Hanford Site. A barge unloading facility 9 miles south of the plant was used for delivery of large construction items for the DOE FFTF and Energy Northwest nuclear projects. These materials were transported by truck or rail to the construction sites from the Port of Benton landing.

The CGS site is serviced by a two-lane paved access road connected to Hanford Site Route 4, which is a paved four-lane major artery located 1.6 miles west of the station. Route 4 is part of the DOE road system. The DOE-owned road system connects the areas of the Hanford Site with paved two-lane and four-lane primary roads, secondary gravel roads, and unimproved roads. State Highway 240 traverses the Hanford Site from the southeast to the northwest. The highway passes within about 7 miles of CGS in the southwest quadrant. The highway connects into State Highway 24, which goes west to Yakima, Washington, and across the Vernita Bridge on the Columbia River 22 miles to the northwest (see Figure 2.2-1).

The Hanford Site (DOE) railroad system (see Figure 2.2-2) connects with commercial rail systems in Richland and Kennewick, Washington. Railroad operations that pass through CGS property are restricted to only those trains that have been authorized by Energy Northwest Security. The rail line is physically blocked at the two points where the plant vehicle barrier crosses the tracks.

Heavy barge traffic north of the Port of Benton dock is not feasible because the river channel is too shallow and the current is too swift. The environmental impact and economic cost of constructing a new barge slip at some upstream location and channeling the river cannot presently be justified with the availability of land transportation between the Port of Benton facility and the Hanford Site.

Making the Columbia River navigable for barges from north of Richland to Wenatchee would result in barge traffic past the CGS site at River Mile 352. However, this situation would not likely occur. Locks or other lift facilities would have to be constructed at the Priest Rapids, Wanapum, and Rock Island Dams. Furthermore, in 2000, a presidential executive order created the Hanford Reach National Monument, protecting the 51-mile Hanford Reach of the Columbia River (Reference 2.2-2). The protected area includes a 1/4-mile-wide corridor on the west side of the river in the vicinity of CGS.

Airports, military facilities, low-level Federal airways, and airport instrument approaches in the vicinity of CGS are discussed in Section 3.5.1.6 and shown in Figure 2.2-3.

An explosives and ordinance test site operated by Pacific Northwest National Laboratory approximately 13 miles northwest of the site was abandoned in mid-1975 (Reference 2.2-3). Explosives for operations such as quarrying or seismic studies on the Hanford Site are brought to the blasting site as needed and unused quantities are removed. Normally the only explosives COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 LDCN-05-011 2.2-3 stored on the Hanford Site are small arms ammunition for use by the security patrols. A small arms firing range used for training by the DOE security patrol is located 8 miles due south of the plant (Reference 2.2-3). Another range, used by Energy Northwest security personnel, is located 1.5 miles east-northeast of CGS on Energy Northwest lease property.

2.2.2 DESCRIPTIONS

2.2.2.1 Description of Facilities Energy Northwest's Plant Engineering Center is located west of the CGS turbine generator building as shown in Figure 1.2-1. It is a two-story, 100,000 ft2 facility designed to house approximately 470 CGS plant staff personnel. The H. J. Ashe Substation is located approximately 0.5 mile north of CGS and is operated by the Bonneville Power Administration as part of its transmission system.

The Energy Northwest permanent meteorological tower is located less than 0.5 mile west of the plant site. The tower is automated so that the only personnel at the tower are those required to make adjustments to the instruments or to perform repairs to the system. There are no permanent personnel at the facility.

The ISFSI is located immediately north-northwest of the plant. Confinement of all radioactive materials at the ISFSI is provided by the required use of NRC certified spent fuel storage casks listed in 10 CFR 72.214. The ISFSI storage cask system consists of an inner stainless steel multi-purpose canister (MPC) and an outer storage overpack. The MPC contains the spent fuel. It is a welded pressure vessel with no bolted closure or mechanical seals. Primary closure welds are examined and leakage tested to ensure their integrity. The MPC redundant closures are designed to maintain confinement integrity during normal conditions of storage, and off-normal and postulated accident conditions. The outer storage overpack is fabricated from concrete and structural steel components that are classified as important to safety. A fully loaded spent fuel storage cask weighs approximately 185 tons. The spent fuel loaded storage casks are located within the Energy Northwest ISFSI protected area which is surrounded by a fence and topped with barbed wire. The ISFSI access gates are locked except when in use.

The Hydrogen Storage and Supply Facility is located 0.6 miles south-southeast of the plant site. The facility is part of a hydrogen water chemistry system to prevent and mitigate intergranular stress corrosion cracking in reactor internal structures and piping welds. The facility consists of a fenced gravel yard with concrete pads constructed to accommodate a liquid hydrogen tank, nitrogen tank, gaseous hydrogen tubes, and all supporting piping and equipment necessary to supply CGS with gaseous hydrogen. The liquid and compressed gases are delivered to the facility by truck.

COLUMBIA GENERATING STATION Amendment 60 FINAL SAFETY ANALYSIS REPORT December 2009 LDCN-09-026 2.2-4 Within the exclusion area radius of 1950 m is Energy Northwest's 1250-MWe WNP-1 project. Construction of the PWR plant, located 1500 m (4925 ft) east-southeast of CGS, was suspended in April 1982. In May 1994 the Energy Northwest Board of Directors voted to terminate WNP-1. The construction of twin unit WNP-4, located 1250 m (4100 ft) east-northeast of CGS, was terminated in January 1982. These projects have a separate access road that ties into the Hanford Site Route 4, 1.6 miles south of the CGS access road. Support activities at either the WNP-1 or WNP-4 sites do not interfere with operation of CGS. These may include activities associated with site restoration and economic development (such as leasing of excess facilities for office space and manufacturing). Within the exclusion area, Energy Northwest has the authority to determine all activities within the meaning of 10 CFR 100.3(a), including the authority to remove all personnel and property from the area.

The Laser Interferometer Gravitational-Wave Observatory (LIGO) is located approximately 3.3 miles west-southwest from the plant site. The mission of this research facility is to observe gravitational waves of cosmic origin. The facility houses laser interferometers, consisting of mirrors suspended at each of the corners of an L-shaped vacuum system measuring 2.5 miles on a side. The materials and activities at this facility do not impact the operation of CGS.

The Umatilla Chemical Depot (UMCD), formerly known as Umatilla Army Depot, is located in northeastern Oregon in parts of Umatilla and Morrow Counties approximately 43 miles south of CGS. In 1962, the UMCD began storing chemical weapons and stored approximately 12% (3717 tons) of the nation's original chemical weapons. The weapons consisted of various munitions and ton containers containing GB (Sarin), VX, or HD (Mustard) agents. Beginning in 1990, the UMCD shipped all conventional ammunition and supplies to other installations and only chemical weapons remained pending disposal. The Umatilla Chemical Agent Disposal Facility was completed in 2001 and uses high temperature incineration to destroy the weapons. The Army began weapons disposal in 2004 and has destroyed all GB and VX nerve agent chemical weapons. In June, 2009, the Army began the HD blister agent disposal campaign which is expected to take between one and two years to complete. Upon completion, the facility will be dismantled and the UMCD will be closed.

As discussed in Section 2.1.1 and shown in Figure 2.1-1, CGS is located on the DOE Hanford Site. In reviewing the plant site and the vicinity for potential external hazards or hazardous material, the Hanford facilities currently operating, recently operating, or with the potential for operating were screened. The facilities discussed below are those believed to pose the most risk to the safe operations of CGS. The safety analysis reports and accident analysis prepared for those facilities were reviewed to determine possible hazards. No accidents evaluated present a physical challenge to the CGS buildings. Releases with the potential to impact the operation of CGS were radioactive particulate that would be effectively mitigated within General Design Criterion (GDC) 19 limits by the control room high-efficiency particulate air (HEPA) filters. Considered but not included were the 200 East Burial Grounds, the Critical Mass Laboratory, the Liquid Effluent Retention Facility, and the Effluent Treatment Facility in the 200 East Area. In the 200 West Area, the T Plant, U Plant, Reduction-Oxidation Plant, COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-11-027 2.2-5 and the 222-S Laboratory were considered but not included. These facilities have insufficient radiological or toxicological inventories in a dispersible form to represent a risk to CGS operation. The specific facilities included are discussed in Table 2.2-1.

Three DOE facilities are located within a 5-mile radius of the plant site. These are the Fast Flux Test Facility (FFTF) and two radioactive waste burial grounds. The specific hazards associated with these facilities are summarized in Table 2.2-1 and the specific activities are listed below:

The FFTF is a deactivated sodium cooled breeder reactor located approximately 3 miles southwest of CGS. All fuel has been removed and shipped to the Idaho National Laboratory. All sodium has been removed, solidified, and is stored on-site. The facility has been placed in a long-term, low-cost surveillance and maintenance condition. The 618-10 (300 North) Waste Burial Ground is approximately 3.5 miles south of CGS. DOE has initiated trench remediation activities at the site. Trench remediation is expected to take 18 months (1/2013).

The 618-11 (Wye) Waste Burial Ground is directly west of CGS, outside of Energy Northwest leased land, but within its 1950-meter exclusion area radius and security perimeter. The site received low- to high-activity waste, fission products, some plutonium-contaminated waste, and non-radiological hazardous waste from March 1962 to December 1967 from the Hanford 300 Area. The waste is buried in 3 trenches, 50 Vertical Pipe Units (VPUs), and four caissons. The site was covered with an overburden of soil when it was closed. The surface was stabilized in 1982 with an additional 2 ft of soil. Since surface stabilization, activities at the site have been limited to monitoring and surveillance. DOE completed non-intrusive surveillance and characterization activities at the site in 2011 to obtain data information and information for planning remediation activities.

The DOE 300, 200 East, and 200 West Areas are located within a 10-mile radius of the site. The current waste management activities (storage, disposal, and treatment) conducted in these areas are discussed in Table 2.2-1. The 300 Area is approximately 7 miles southeast of CGS. The only hazard presented to CGS from this site is from the spent nuclear fuel and other radioactive material stored there. There is an unknown quantity of miscellaneous reactor fuel material in the 300 Area. This quantity is not publicly available information.

The DOE 200 East and 200 West Areas are approximately 10 miles northwest of CGS. Originally these facilities were constructed to support the extraction of weapons grade plutonium for the defense program. However, as the Hanford mission has changed from production to environmental cleanup, so has the purpose of the facilities discussed. This COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-6 change in mission has, in some cases, resulted in a change in the hazards presented to CGS plant site and personnel.

A private (non-DOE) low-level radioactive waste disposal area is adjacent to 200 East Area. There are also plans to build private waste vitrification facilities adjacent to 200 East. These facilities are also discussed in Table 2.2-1.

Several plutonium production reactor facilities are located approximately 20 miles north-northwest of CGS. All of the reactors were water cooled, graphite moderated. The last operating reactor, the N Reactor, was permanently shut down in 1991. The N Reactor also provided steam for the Energy Northwest Hanford Generating Station until 1987. The fuel has been removed from the reactors for storage or treatment. The current activities at these reactor sites are also discussed in Table 2.2-1.

The nearest petroleum product storage tanks are located 22 miles southeast of the site: approximately 23 million gal capacity at the Chevron Pipeline Company and approximately 20 million gal capacity at the Tidewater Barge Lines.

2.2.2.2 Description of Products and Materials The existing Hanford Site railroad track (owned by the DOE and operated by a private contractor in support of the Hanford Operations), and the CGS, the WNP-1, WNP-4, and the FFTF railroad spurs all run within the exclusion area of the plant site. Shipments of large quantities of hazardous materials on this track that existed during initial licensing of CGS are no longer made (Reference 2.2-4).

The DOE has no plans for railroad shipments of explosives in the foreseeable future. However the DOE's Richland Operations Office has agreed to notify Energy Northwest prior to transporting any explosive shipments of more than 1800 lb past CGS (Reference 2.2-5). Energy Northwest will provide an analysis to the NRC of the potential consequences prior to the start of such shipping (Reference 2.2-6).

Hazardous material is also transported on Hanford Route 4 by DOE. Chlorine is the only material of concern transported on Route 4 with the potential for impacting CGS operation.

Section 6.4.4.2.1 provides additional information on control room habitability assessments for CGS.

The Yakima Training Center, a sub-installation of Fort Lewis, is 30 miles northwest of the site. The center consists of 327,000 acres. The center provides training facilities and logistical support and it is used for firing of all types of ordnance, both in a direct mode and by indirect artillery and mortars. Weapons to 155mm are fired. This type firing occurs frequently. Other types of live ordnance use at the center include aerial delivery by high performance aircraft of ordnance to include 2,000-lb bombs, helicopter weapons which include automatic weapons and COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-7 2.75-in. folding fin rockets, and anti-aircraft missiles. These latter activities are significant as to occurrence. The majority of the ordnance impacts a 20,000-acre area which is generally located in the central portion of the center. All activities are confined to the geographical limits of the center and/or its restricted air space unless special arrangements are made with affected agencies. Mechanized units (i.e., tanks and armored personnel carriers) from Fort Lewis and reserve components conduct extensive maneuvers on all accessible areas of the Training Center and use specially designed ranges to practice firing their weapons. Infantry and engineer units that support the mechanized units also train at the center. Training activity is greatest from March to November. War games sometimes involve troop and equipment deployment at the Richland Airport and along Highway 243 west of Vernita Bridge. Helicopters may fly near the Hanford Site, or military vehicles may travel over Highway 240 (Reference 2.2-7).

2.2.2.3 Pipelines There are no commercial oil or gas pipelines in the vicinity of CGS. The nearest major natural gas transmission pipeline to the site is about 12 miles. A 20-in. gas transmission line of the Northwest Pipeline Corporation is located east and essentially parallel to U.S. Highway 395 between Pasco and Ritzville, Washington. A second pipeline system consisting of parallel 36-in. and 42-in. lines, owned by Pacific Gas Transmission Company, passes through Wallula, approximately 24 miles from the site (Reference 2.2-8). These distances eliminate any potential hazard to plant operations due to a natural gas fire or explosion. The Energy Northwest Hydrogen Storage and Supply Facility is located 0.6 miles south-southeast of the plant and is connected to the plant with a 2-in NPS gas pipeline. The pipeline runs north from the facility approximately 400 ft east of the plant and then turns and runs west approximately 400 feet north of the plant then south approximately 200 ft west of the plant to its connection point on the west side of the Turbine Building. Fire and explosion risks to the plant involving this pipeline are discussed in Appendix F and Section 3.5.1.5.

2.2.2.4 Waterways Makeup water inlet structures are located in the Columbia River 315 ft from the shoreline at low river flow (36,000 cfs; el. 341.73 ft) at river mile 351.75.

A significant amount of Columbia River barge traffic moves as far upstream as the Ports of Pasco and Kennewick. Also, a docking facility established by the Port of Benton in North Richland (approximately 9 miles downstream of the CGS site) is accessible by barges with a maximum 16 ft of draft (normally 2500 to 3000 tons). The first use of this facility was in April 1973 when the FFTF reactor vessel was off-loaded. Traffic to the North Richland dock is very infrequent in comparison to that in Pasco and Kennewick due to the lack of large industrial concerns in the region between Richland and Priest Rapids Dam. This facility is most often used to off-load dismantled nuclear components. On several occasions in the past, COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-8 lightly loaded barges have transported material to the vicinity of the Hanford Site. This required maintenance of an adequate flow from Priest Rapids Dam during the transit period. 2.2.2.5 Airports Three commercial airports are within 20 miles of CGS. The closest is Richland Airport 11 miles south of the plant. This general aviation airport has two 4000-ft runways, one with a 010/190 orientation and the other with a 070/250 orientation. Visual flight rule landings are standard for Federal Aviation Administration (FAA) non-control-tower airports.

The Tri-Cities Airport 17 miles southeast near Pasco is the largest airport within 40 miles. The FAA operates the air traffic tower and airport radar approval control facility. The airport has two 7700-ft crossing runways with 120/300 and 030/210 orientations. The latter has a 4430-ft parallel runway. Runway 30 has a very high frequency omnirange (VOR) instrument approach and Runway 21R has an instrument landing system and is an instrument approach runway.

The Vista Airport operated by the Port of Kennewick is a general aviation airport located 18 miles south-southeast. It has a 4000-ft runway with a 20/200 orientation. All operations are under visual flight rules.

Information relative to the flight paths and activity at these three commercial airports, the Yakima Training Center, and the nearby private airstrips is discussed in Section 3.5.1.6.

2.2.2.6 Projection of Industrial Growth There is no projected growth of waterway traffic nor plans for oil and gas pipelines within 10 miles of CGS.

2.2.3 EVALUATION OF POTENTIAL ACCIDENTS

2.2.3.1 Determination of Design Basis Events Energy Northwest has investigated the resistance of plant structures to explosions. The reactor building is a reinforced-concrete structure up to the refueling floor and is designed to withstand the worst probable combination of wind velocity and associated pressure drop due to a design basis tornado. A differential pressure of 3 psi between the exterior and interior of the building is also considered in the design. At its nearest point, the railroad is 510 ft from the reactor building.

From the above criteria, it has been determined that the reactor building can resist an explosion of 20,000 lb of dynamite on a railway car 510 ft from the reactor building. The performance of the reactor building structure for this blast loading condition will be similar to that for the COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-9 original design basis tornado loading condition based on the 3 psi differential pressure used in the original tornado analysis.

In the unlikely event of an explosion or fire on the railroad affecting the 115-kV shutdown power supply, the 230-kV power supply or the diesel generators would fulfill that function.

It is extremely unlikely that an explosion or fire on the mainline railroad would compromise the safe shutdown of the facility. As noted in Section 2.2.2.2, DOE has no plans to ship explosives on the railroad, and the agency will notify Energy Northwest prior to the shipment of explosives in a quantity greater than 1800 lb. Energy Northwest Security controls access to the rails that pass near the plant. The only explosives on the Hanford Site are small arms munitions. As described in Section 2.2.2.2, this represents no hazard to the operation of CGS. The Yakima Training Center does not endanger the site. Hydrogen gas stored in the gas bottle storage building and in a trailer parked adjacent to the gas bottle storage building will not pose any fire or explosion problem because of the light weight properties and dispersal qualities of the gas and the distances (approximately 400 ft) between the storage areas and any safety-related equipment. Hydrogen gas stored at the Hydrogen Storage and Supply Facility (HSSF) and transported to the plant by pipeline does not pose a significant fire or explosion risk to the plant as discussed in Appendix F and Section 3.5.1.5. Habitability considerations for the control room and quantities of hydrogen gas stored in/adjacent to the gas bottle storage building and at the HSSF are discussed in Section 6.4.4.2.3.

Table 2.2-1 summarizes the potential events at the Hanford Site facilities that could present a radiological or chemical hazard or hazardous situation to the continued safe operation of CGS. The cesium and strontium capsules stored at the Waste Encapsulation and Storage Facility (WESF), the fuel stored at the K Basins, and the high level waste stored in the tank farms present contributions to risk at CGS due to presence of 137Cs, 90Sr, and 241Am. However, based on consideration of the radionuclide inventory at risk, the ability to transport this inventory, and the proximity of the storage facility, the risk is dominated by the inventory stored at WESF. The probability of the loss of cooling in the capsule storage pool is extremely low, but the potential dose to unprotected CGS personnel due to the release is significant. Any required evacuations would be performed as discussed in the Emergency Plan. The design basis accident at WESF would not result in a condition at CGS which would challenge the criteria established in 10 CFR 100.

In each event evaluated, the radiological dose resulting from particulate releases would be adequately filtered by the control room HEPA filters, mitigating any challenge to the habitability of the control room. None of the facilities present a chemical exposure risk to CGS. Radiological exposures for postulated events on the Hanford Site are characterized by the contribution from gaseous radionuclides because of the short half-life of 131I and because the other noble gases were released during the spent fuel processing.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-10 The Yakima Training Center, discussed in Section 2.2.2.2, is used for military maneuvers and weapons training and is the only significant military activity in the vicinity of the Hanford Site. The only weapon currently in use at the Yakima Training Center known to present a hazard to the Hanford Site is the multiple launch rocket system (MLRS). With a range in excess of 25 miles, the MLRS could potentially impact the CGS site. However, the MLRS is only fired from the perimeter of the Yakima Training Center into a centrally located impact zone and is only fired with dummy warheads. Given this information, additional safety features, and the administrative controls in place at the Yakima Training Center, a weapons accident having an impact on CGS is very improbable.

The Umatilla Chemical Depot, discussed in Section 2.2.2.1, is used to store chemical weapons. As part of the program to demilitarize chemical weapons, an incinerator has been constructed at the Depot for disposal of the weapons. Risks associated with weapons disposal operations at the Umatilla Chemical Depot have been quantified in a Phase 1 Quantitative Risk Assessment (QRA) prepared for the U.S. Army. The QRA examined risks associated with storing munitions at the Depot, transporting munitions from the storage igloos to the incinerator, and processing munitions within the incinerator. Although not directly transferable to the assessment of effects at CGS, the risk estimates provide some inferences regarding the risks to plant operation. A review of the assessment concluded that the risk to persons in the 60 to 100 km distance range due to chemical munitions disposal are very small. It should also be recognized that operations at the Depot would be within the scope of a comprehensive emergency preparedness program that includes offsite notification. Furthermore, pursuant to Regulatory Guide 1.78, chemicals stored or situated at distances greater than 5 miles from CGS need not be considered because, if a release were to occur, atmospheric dispersion will dilute and disperse the incoming plume to such a degree that either toxic limits will never be reached or there would be sufficient time for control room operators to take appropriate action. In addition, the probability of a plume remaining within a given sector for a long period of time is quite small (Reference 2.2-9).

As stated in Section 2.2.2.1, confinement of all radioactive materials at the ISFSI is provided by the required use of NRC certified spent fuel storage casks listed in 10 CFR 72.214. Pursuant to the 10 CFR 72.212 report, evaluations performed in support of the ISFSI have demonstrated the reactor site-specific parameters are bounded by the safety analysis for the generically approved cask. Accordingly, activities associated with the facility do not adversely impact operation of CGS (Reference 2.2-10).

Brush fires have occurred on the Hanford Site and have presented no potential hazard to existing facilities. Areas adjacent to CGS major buildings and auxiliary facilities are maintained to prevent weed growth by landscaping, gravel, ground cover, and weed control spraying. The Hydrogen Storage and Supply Facility (HSSF) is landscaped with gravel beyond the perimeter of the site, exceeding the code required clearance distance, to keep the area free from dry vegetation and combustible materials. These or similar methods of weed control minimize brush fire hazards to CGS facilities.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-11 The potential effects of fires that involve materials used in the operation of the plant are discussed in Appendix F.

The formation of unconfined vapor clouds caused by the accidental release of flammable or toxic liquids or vapors stored at the plant site is discussed in Section 6.4 and addressed by the Emergency Plan.

The non-safety-related makeup water intake consists of two sets of paired perforated pipe sections. One set is capable of supplying the full makeup water requirements of the plant. Extreme low river flow (36,000 cfs) will provide about 0.5 ft of water over the top of the intake pipes. The probability of damage to both sets of intakes as a result of a pleasure boat or barge accident is extremely remote given the infrequency of both extreme low flows and large boat and barge traffic. In the unlikely event that such an accident might occur, destruction of the makeup water intake structure would be comparable in effect to loss of offsite power to the makeup water pumps. The Seismic Category I spray ponds provide for 30-day cooling without makeup. This is ample time to restore makeup from either the river or wells.

There are no upstream industrial facilities for which waterborne deliveries of significant quantities of petroleum products, corrosive chemicals, or other hazardous materials are expected. Fuel oil, diesel oil, acids, and caustics are stored at the N-Reactor site. The oil storage facilities are protected by dikes, and the chemical storage facilities are far enough from the river to avoid direct discharge. Thus, there is no possible hazard to the plant due to spillage of such materials into the river. There are no upstream releases which may be corrosive, cryogenic, or coagulant.

2.2.3.2 Effects of Design Basis Events As discussed in Section 2.2.3.1, the activities of nearby industrial, transportation, and military facilities will have no adverse effect on the plant.

2.

2.4 REFERENCES

2.2-1 Holmes, D. B., Energy Northwest, personal communication with Steve Burnam, Site Infrastructure Division, Department of Energy, July 31, 1998.

2.2-2 Presidential Proclamation 7319, Establishment of the Hanford Reach National Monument, 65 FR 37253, June 9, 2000.

2.2-3 Chasse, J. P., Energy Northwest, personal communication with B. J. Rokkan, Safeguards and Security Division, DOE, Richland Operations Office, December 6, 1977.

COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 2.2-12 2.2-4 Note, D. A. Marsh, Westinghouse Hanford, to D. E. Larson, Supply System, dated January 22, 1993. 2.2-5 Memorandum, C. A. Hansen, Assistant Manager for Waste Management, DOE-RL to Alice Q. Murphy et al., 98-WPD-032, February 20, 1998.

2.2-6 NUREG 0892, Safety Evaluation Report Related to the Operation of WPPSS Nuclear Project No. 2, Section 2.2.1, March 1982.

2.2-7 Arbuckle, J. D., Energy Northwest, personal communication with J. Reddick, Executive Officer, Yakima Training Center, July 29, 2003.

2.2-8 Hosler, A. G., Contact with Local Organizations to Support CSB SAR Chapter 1 (Memo 042AGH.96 to Canister Storage Building Report File), Science Applications International Corporation, May 6, 1998.

2.2-9 Holmes, D. P and Chasse, J. P., Energy Northwest, White Paper -- Applicability of the Chemical Stockpile Disposal Program at the Umatilla Army Depot to the WNP-2 FSAR, December 1997.

2.2-10 Energy Northwest, Independent Spent Fuel Storage Installation 10 CFR 72.212 Evaluation, Docket Number 72-35, Revision 1, September 2002.

Table 2.2-1 Hanford Site Nuclear Facilities Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-11-027 2.2-13Fast Flux Test Facility (FFTF) Ref: Surveillance and Maintenance Plan for FFTF, Rev. 0, DOE/RL-2009-26 Deactivated sodium cooled breeder reactor Activated solid sodium 1) 180,000 lb sodium spill hr dose at 1.5 mi = 0.015 mrem, 24-hr dose at 4.5 mi = 0.26 mrem Particulate release, effectively mitigated by distance DOE 618-10 (300 North) Waste Burial Ground Ref: Final Hazard Categorization for the 618-10 Burial Ground Remediation, Rev.2, February 2011, WCH-390 Disposal site with broad spectrum of low- to high-level solid radioactive wastes buried in caissons or pipe Radioactive waste Caisson penetration with fire - unmitigated dose at 5 km = 10.2 mrem Particulate release, effectively mitigated by distance (>5 km) DOE 618-11 (Wye) Waste Burial Ground Ref: 618-10 and 618-11 Waste Burial Grounds Basis for Interim Operation, Rev. 1, WCH-183 Disposal site with broad spectrum of low- to high-level solid radioactive wastes and non-radiological hazardous materials buried in caissons or pipe Radioactive waste inventories, primarily Cs-137, Sr-90, and Pu-239 and non-radiological hazardous materials bounded by beryllium Caisson penetration with fire and explosion: control room doses are less than 0.1 rem; beryllium oxide concentration of 4.6 x 10-3 mg/m3 at 100 m from 618-11 site boundary Particulate release, effectively mitigated by credited 618-11 Waste Burial Ground project controls. The soil overburden covering the VPUs and caissons in the 618-11 Waste Burial Ground is credited for reducing releases and is designated as a passive design feature. No missiles are postulated for this event.

Table 2.2-1 Hanford Site Nuclear Facilities (Continued) Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORTDecember 2011 2.2-14 B Plant Ref: B Plant Basis for Interim Operation, March 6, 1997, HNF-SD-BIO-003 Process to remove cesium and strontium from radioactive waste, deactivated, currently in surveillance and maintenance mode Residual radionuclide inventories on cell filters (137Cs, 90Sr, and 241Am) Flooding cell 291-B HEPA filters - 0.368 rem max. public dose Particulate release effectively mitigated by distance Plutonium-Uranium Extraction Facility (PUREX). PUREX End State Basis for Interim Operation (BIO) 1997, HNF-SD-CP-15B-004 (Draft) Currently shut down, in preparation for decommissioning and decontamination Residual plutonium and uranium contamination Design basis earthquake, dose @ 100 m - 1.9 rem; 12 km - 7.4 x 10-4 rem Particulate release, mitigated by distance Plutonium Finishing Plant (PFP) Ref: Plutonium Finishing Plant Final Safety Analysis Report, 1995, WHC-SD-CP-SAR-021 Receipt and storage of SNM, reactive material stabilization, radioactive and mixed waste handling Stored SNM, and residual plutonium contamination Design basis earthquake, 8-hr dose of 15.2 rem @550 m 24-hr dose of 0.31 rem @12,500 m Particulate release, mitigated by distance Tank Waste Remediation System (TWRS) Facilities Ref: Tank Waste Remediation System Basis for Interim Operation, 1997, HNF-SD-WM-BIO-00, Revision 0 Mixed radioactive and chemical wastes storage in 149 single shell tanks (SST) and 28 double shell tanks (DST) in 12 tank farms

Associated support facility: 242-A-Evaporator SSTs contain combinations of sludge, saltcake, and interstitial and pooled liquids

DSTs contain liquid and slurry waste with small amounts of sludge Table 2.2-1 Hanford Site Nuclear Facilities (Continued) Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORTDecember 2011 2.2-15Tank Waste Remediation System- Project (TWRS-P) (private facilities, proposed for construction in 2000) Ref: DOE/RL-96-0006 Vitrify low level, high level, and transuranic mixed waste High level radioactive waste Requirements for authorization limit to less than 25 rem/event in an accident. Releases are projected to be airborne particulate. HEPA filter system would protect CGS control room operators, in accordance with the limits of GDC 19 Waste Encapsulation and Storage Facility (WESF)

Ref: Waste Encapsulation and Storage Facility Basis for Interim Operation, 1997, HNF-SD-WM-BIO-002 Conversion process for cesium and strontium has halted Cesium chloride and strontium fluoride salts, encapsulated in double-walled metal containers stored in water-filled cooling basin Capsule rupture following loss of water from storage pool - 24 hr exposure to public, 9 rem Control room exposure mitigated by HEPA filters; potential evacuation of other personnel Low-Level Waste Disposal Site (Private) Buried storage of low-level radioactive waste in lined containers Low-level buried waste, monitored as required by NRC license No credible event None Canister Storage Building (CSB)

Ref: Letter; DOE to H. J. Hatch, Flour Daniel Hanford, 28 May 97 Storage of spent nuclear fuel (SNF) from the K Basins in sealed multi-canister overpacks (MCO) 2100 metric tons of spent fuel, from production reactors Requirements for authorization limit to less than 5 rem/event in an accident. Releases are projected to be airborne particulate HEPA filter system would protect CGS control room operators, in accordance with the limits of GDC 19 Cold Vacuum Drying Facility (CVDS) Ref: Letter; DOE to H. J. Hatch, Flour Daniel Hanford, 28 May 97 Draining and vacuum drying to remove water from MCOs in preparation for interim storage at CSB Spray release Requirements for authorization limit to less than 5 rem/event in an accident. Releases are projected to be airborne particulate. HEPA filter system would protect CGS control room operators, in accordance with the limits of GDC 19 Table 2.2-1 Hanford Site Nuclear Facilities (Continued) Facility Description Hazard Design Basis Event Impact on CGS COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORTDecember 2011 2.2-16B, C, D, DR, F, and H Reactors (shutdown since 1969)

Ref: WHC-EP-0619, Vol. 1. Single-pass, water-cooled, graphite-moderated reactors The onsite hazards involve personnel injury, primarily falls and electric shock. No significant offsite risks No credible event None K East and West reactors (shutdown since 1971)

Ref: WHC-EP-0619, Vol. 1. Single-pass, water-cooled, graphite-moderated reactors The onsite hazards involve personnel injury, primarily falls and electric shock. No significant offsite risks No credible event None K East and West Basins Ref: WHC-EP-0619, Vol. 1. Storage basins for spent fuel, some severely degraded Approximately 2100 metric ton inventory of irradiated reactor fuel Dropping and overturning of a transfer cask containing reactor fuel. (Bounding event; but transfer is administratively prohibited) None N reactor (shutdown since 1987) and N Basin Ref: WHC-EP-0619, Vol. 1. and BHI-00866, Rev 0 A pressure tube, water-cooled, graphite-moderated reactor with fuel assemblies removed for decontamination and decommissioning The onsite hazards involve personnel injury, primarily falls and electric shock. No significant offsite risks No credible event None Amendment 55May 2001Hanford Reservation Road System990306.152.2-1FigureForm No. 960690Draw. No.Rev.Arid LandsEcology ReserveColumbia RiverRichlandBenton CityYakima RiverWNP-1WNP-4* HANFORD RESERVATION ROADS STATE HIGHWAYS

• WNP-4 HAS BEEN TERMINATED108642021MILES22424240243242224200W200EColumbia Generating StationFinal Safety Analysis ReportColumbiaGeneratingStation12121212 Amendment 55May 2001Hanford Reservation Railroad System990306.162.2-2FigureForm No. 960690Draw. No.Rev.Arid LandsEcology ReserveHanford No. 1Columbia RiverRichlandBenton CityYakima RiverColumbiaGeneratingStationWNP-1WNP-4* HANFORD RAILROAD SYSTEM* WNP-4 HAS BEEN TERMINATED108642021MILESColumbia Generating StationFinal Safety Analysis Report NORTHFigureAmendment 57December 2003Form No. 960690Draw. No.Rev.Federal Airways and InstrumentApproaches/Departures900547.962.2-3Columbia Generating StationFinal Safety Analysis ReportSUNNYSIDEPROSSERBentonCountyRICHLANDPASCOCOLUMBIACOLUMBIA RIVERAGCARRKENNEWICKVISTAFFTFCOLUMBIAAG 2BASIN CITYWye BarricadeMcWHORTERHanford SiteBoundaryMATTAWAGrantCountyChristensenBros.DESERT AIR301V187°Adams CountyTAGGARESFIELDKENTFARMSOTHELLOCONNELCITYFranklin CountyGREENACRES332°YakimaTrainingCenterCGS200West200EastSLINKARD269°2424324172404SVR1350V281IR329IR329IR329VR1351VR1360VR497V2041239539539582182 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-1 2.3 METEOROLOGY The italicized information, including associated tables and figures, is historical and was provided to support the application for an operating license.

2.3.1 REGIONAL CLIMATOLOGY*

2.3.1.1 General Climate The site is located in a mid-latitude semi-arid (steppe) climatic region in the Lower Columbia Basin which is the lowest elevation of any part of central Washington. A major factor influencing this climatological region is its location in the continent, well away from the windward coast and protected to the west by the 4,000 to 7,000-ft average elevation Cascade Mountains. Dominant air masses affecting the region are of maritime polar origin as modified by the presence of these mountains. Modified continental tropical and polar air masses also periodically affect the climate. In winter, there is a succession of cyclones as the westerlies and the polar front prevail in these latitudes. The mountain barriers commonly induce these storms to occlude by delaying air mass movement. Fewer frontal passages occur during the summer months since subtropical oceanic high cells reach their highest latitudes thereby diverting cyclonic storms poleward. Along the eastern margin of the Pacific anticyclone, an out-flow of stable subsiding air brings distinctly drier conditions to the North American Pacific coast.

The regional temperatures, precipitation, and winds are greatly affected by the presence of the mountain barriers. The Rocky Mountains and ranges in Southern British Columbia are effective in protecting the inland basin from the more severe winter storms and associated cold polar air masses moving southward across Canada. Occasionally, an outbreak of cold air will pass through the Basin and result in low temperatures or a damaging spring or fall frost. Maritime polar air traveling eastward from the coastal zone cools as it rises along the western slope of the Cascade Range. These orographic effects cause heavy precipitation on the windward and light precipitation on the leeward slopes. The prevailing westerly. winds are normally strongest during winter and spring due to the presence of cyclonic scale disturbances and associated frontal activity. During those months, foehn or chinook winds (a warm dry

• This section is based on records kept at the Hanford Meteorology Station (14 miles northwest of the site, elevation 733 ft MSL) from 1945 to 1980 (2) and 100-N area sites (1) (supplemented with precipitation and temperature data taken by U.S. Weather Bureau cooperative observers at a site about 25 miles north of the present station location during the period from 1912 to 1944 (2,3) and regional climatological data gathered during the period from 1931 to 1960). (4) Other references are as indicated.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-2 wind on the lee side of a mountain range; the warmth and dryness of the air is due to adiabatic compression upon descending the mountain slopes) occur whenever cyclonic circulation is sufficiently strong and deep to force air completely across the cascades in a short period of time. At other times during the winter, warm front occlusions can force moist air over the Cascade Range. The mixing of this moist air with relatively cooler air in the Basin results in considerable cloudiness and fog. The percent of possible sunshine ranges from 20 to 30 percent in winter, 50 to 60 percent in spring and fall, and 80 to 85 percent in mid-summer. Because the site is in the rain shadow of these mountains, annual average precipitation decreases from about 100 inches near the summit of the Cascades to about 6 or 7 inches in the Basin. Approximately 70 percent of the annual total precipitation occurs from November through April and about 10 percent occurs during July through September. Rainfall amounts are normally light in the summer and gradually increase in late fall, reaching a peak of about one inch each month in midwinter due to cyclonic storm and frontal activity. Rainfall amounts decrease in Spring, increase somewhat in June, and again sharply decrease in July. During mid-summer, it is not uncommon to have 3- to 6-week periods with trace rainfall. There are only two occurrences per year of 24-hour amounts of 0.50 inch or more, while occurrences of 24-hour amounts of 1.00 inch or more number only four in the entire 25 years of record (1946 to 1970). One of these was the record storm of October 1 through 2, 1957, in which rainfall totaled 1.08 inches in three hours, 1.68 inches in six hours, and 1.88 inches in twelve hours. At the other extreme, there have been 81 consecutive days without measurable rain (June 22 through September 10, 1967), 139 days with only 0.18 inch (June 22 through November 7, 1967), and 172 days with only 0.32 inch (February 24 through August 13, 1968).

About 45 percent of all precipitation during the months of December, January, and February is in the form of snow. Regional annual total snowfall amounts have ranged from less than 1/2 inch in 1957 to 1958 to 56.1 inches for the winter of 1992-1993; the annual average total is about 14 inches.

Snow rarely remains on the ground longer than two to four weeks or reaches a depth at any time in excess of four to six inches, as rapid melting, which often contributes to local stream flooding, can occur from rain or Chinook winds. The record greatest depth of 24.5 inches occurred in February 1916.

Thunderstorms have been observed in the area in every month except November. Although severe ones are rare, lightning strikes have occasionally ignited grass fires which burned thousands of acres of the Hanford Reservation and resulted subsequently in considerable wind erosion of soil. The most notable of these occurrences were in August 1961, July 1963, and July 1970, and August 1984.

The continental-type climate not only affects precipitation in the Basin but also results in wide ranges and variations in annual temperature conditions. While the regional annual average temperature is about 53°F, the coldest month, January, has a mean of about 29°F; the COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-3 warmest month, July, has a mean of about 76°F. Although the presence of the cascades contributes to the wide differences in monthly average temperatures, other mountain ranges shield the area from many of the arctic surges, and half of all winters are free of temperatures as low as 0°F. However, six winters in 58 of record have contributed a total of 16 days with temperatures of -20F or below; and in January to February 1950, there were four consecutive such days. There are ten days of record when even the maximum temperature failed to rise above zero. At the other extreme, in the winter of 1925 to 1926, the lowest temperature all season was +22F. Although winter minima have varied from -27F to +22F, summer maxima have varied only from 100°F to 115°F. However, there is considerable variation in the frequency of such maxima. In 1954, for example, there was only one day with a maximum as high as 100°F. On the other hand, there have been two summers (1938 and 1967) when the temperature went to 100°F or above for 11 consecutive days.

Although temperatures reach 90°F or above on about 56 days a year, there are only about seven annual occurrences of overnight minima 70°F or above. The usual cool nights are a result of gravity winds.

The channeling of air by the Cascade Mountains and surrounding terrain produces a prevailing WNW and NW regional flow. Local topographic features can cause other channeling effects and formation of local diurnal wind circulation systems which produce a greater degree of variability in winds at locations within the Basin. For example, the Columbia Generating Station (CGS) site experiences a bimodal wind direction distribution from approximately south and also northwest; at the Hanford Meteorological Station (HMS) about 14 miles northwest, the direction distribution displays a single peak at approximately WNW to NW (refer to 2.3.2).

Drainage (gravity) winds channeled by topographic features produce a marked effect on diurnal range of wind speed and cause the highest monthly average speeds of about 9 mph to occur during the summer months. In July, for example, hourly average speeds range from a low of 5.2 mph from 9 to 10 a.m. to a high of 13.0 mph from 9 to 10 p.m. In contrast, the corresponding speeds in January are 5.5 and 6.3 mph. These warm season diurnal winds, resulting from relatively cold air draining from the Cascade Mountains, occur in response to pressure gradients created between surface-heated warm, dry basin air and cooler air situated over the mountains and coastal region. This favors an outbreak of stronger winds during the afternoon and evening hours. Although the gravity wind occurs with regularity in summer, it is never strong unless reinforced by frontal activity. In June, the month of highest average speed, there are fewer instances of hourly averages exceeding 31 mph than in December, the month of lowest average speed. A complete summary of the monthly averages and extremes of climatic elements at the Hanford Reservation appears in Table 2.3-1.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-4 2.3.1.2 Regional Meteorological Conditions for Design and Operating Bases 2.3.1.2.1 Severe Weather Phenomena

2.3.1.2.1.1 Heavy Rain, Snow, and Ice. Glaze is a coating of ice, generally clear and smooth, but with some air pockets. It is formed on exposed objects by the freezing of super-cooled drizzle or rain drops. Glaze is denser, harder, and more transparent than either rime or hoar frost. Although the record shows an average of seven glaze days per year, many of these cause little or no inconvenience to the public. Two outstanding exceptions occurred on February 11 to 12, 1954, and on November 23 to 24, 1970. There was serious disruption to Hanford traffic in each instance although there was no known damage to transmission lines. In each instance, rising temperatures soon melted the ice.

Precipitation frequency (rain and snow), intensity, and quantity statistics are presented in Figures 2.3-1 and 2.3-2 and Tables 2.3-2 and 2.3-3. For the winter of 1992-93, the following snowfall records were set: greatest winter snowfall (56.1 inches); most days with greater than 1, 6, and 12 inches on the ground (71, 41, and 9, respectively); and greatest 24-hour snowfall (10.2 inches) on February 18 and 19. Probable maximum precipitation is given in 2.4.3.1.

2.3.1.2.1.2 Thunderstorms and Hail. Thunderstorms may occur during any month of the year at Hanford. A thunderstorm day is one in which thunder is heard. If a thunderstorm should begin in late evening and last past midnight, it is counted as two thunderstorm days even though only one storm event occurred. Similarly, should there be two or more distinct thunderstorms in a day - and this sometimes happens - it is counted as a single thunderstorm day. The table below shows the monthly frequency of thunderstorms.

HMS THUNDERSTORM DAYS: 1945-1970

J F M A M J J A S O N D SUM Total 0 1 7 18 53 64 46 54 24 5 0 0 272 Average 0 # # 1 2 3 2 2 1 # 0 0 11 % of Total 0 # 3 7 19 23 17 20 9 2 0 0 100 # = Less than 0.5 Although the table above shows 0 for the months of November through January, a thunderstorm occurred at HMS on December 22, 1971. In Richland, one occurred on January 18, 1953. However, the thunderstorm season essentially includes only the months of April through September. Although the average is eleven days per year, the number has varied from three to twenty-three. In June 1948, there were eight thunderstorm days during the month; and this record was repeated in August 1953. The records show that cold fronts probably constitute the greatest single cause of thunderstorms at HMS. During the years of 1947 to 1955, 43 percent of all thunderstorm days during the months of May through August COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-5 were directly associated with cold frontal passages. On several occasions (notably on August 7, 1953), lightning has struck the HMS tower.

Peak gust data are not available for the 50-, 200-, and 400- ft levels prior to 1952. Of the 185 thunderstorm days occurring during the period of 1952 to 1970, the speed classification of peak gusts on these days is as follows:

Number of Cases  % of Total mph 50 ft 200 ft 400 ft 50 ft 200 ft 400 ft < 21 18 9 5 10 5 3 21 -30 75 45 42 40 24 23 31 -40 63 80 73 34 43 39 41 -50 23 34 46 12 19 25 51 -60 4 11 12 2 6 8 61 -70 1 4 5 1 2 3 > 70 1 2 2 1 1 1 185 185 185 100 100 100 Precipitation was not measured during 1945 and 1946 in which 26 thunderstorm days occurred. During the period of 1947 to 1970, 246 thunderstorm days were recorded. The daily precipitation distribution during these days was as follows:

Amount - Inches Number of Cases % of Total None or trace 110 45 0.01 - 0.10 87 35 0.11 - 0.25 29 12 0.26 - 0.50 15 6 > 0.50 5 2 246 100 Precipitation intensities are defined in Reference 2.3-5.

The record for rainfall intensity during a thunderstorm is 0.55 inch in 20 minutes (1.65 inches per hour) on June 12, 1969. This storm included hailstones of 1/4-inch diameter.

Hail was reported on fourteen, or 5 percent, of the total thunderstorm days. Blowing dust or dust was reported on sixteen thunderstorm days and both hail and blowing dust or dust on six days.

Hail is a rare phenomenon at Hanford. For all years of record, hail has not occurred more than twice in any year. Of the 272 thunderstorm days from 1945 to 1970, hail was reported on fourteen or 5 percent of these days. Hail was also reported on two days without occurrence COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-6 of either a cold frontal passage or a thunderstorm on the same day. The distribution by months of days on which hail occurred is as follows: J F M A M J J A S O N D Total Number 0 1 1 4 2 1 2 2 1 0 0 0 14 % of Total 0 7 7 30 14 7 14 14 7 0 0 0 100 Where size was reported, all except two reports indicated sizes in the 0.2- to 0.3-inch range. The exceptions were May 26, 1954, and July 1, 1955, when the size reported was 0.4 inch. There is no known case of local damage from hail. 2.3.1.2.1.3 Tornadoes

The State of Washington experiences, on the average, less than one tornado each year. Within a one hundred mile radius of the site, only fourteen tornadoes have been reported since 1916. These tornadoes are listed in Table 2.3-4. Of these fourteen recorded tornadoes, only five had any damage associated with them. A more extensive survey of tornadoes in the three northwestern states (Washington, Oregon, and Idaho) was performed by Fujita (6). His results indicate that tornadoes and hailstorms in this area occur primarily in "alleys". The locations of these "alleys" are shown in Figure 2.3-3 along with locations of tornadoes which have been recorded in the tri-state area during the twenty-year period from 1950 to 1969.

Jaech (7) has analyzed the data of Fujita (6) to determine the probability of a tornado striking the Jersey Nuclear Company Fuel Facility (now Siemens Power Corporation), which is located about eight miles from the site. His analysis estimates the probability of occurrence of a tornado in the vicinity of the Exxon site as six chances in a million during any given year or about one chance in four thousand during a forty-year plant life.

The peak tornado wind velocity estimated for the site is 214 mph (Reference 2.3-7). This includes an estimated maximum rotational and translational wind velocities (at a 95-percent confidence level). Daubek (Reference 2.3-8) estimates the maximum translational velocity to be 30 mph. The maximum pressure drop in the center of the tornado relative to the environment is estimated to be up to 1.5 psi (Reference 2.3-6). These values are equal to or less than those tornado parameters listed for a Class III region (which includes the site location) in Regulatory Guide 1.76, issued April 1974. Prior to the issuance of this guide, CGS was designed to withstand some of the most stringent NRC tornado criteria presented for a site located within a Class I region.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-7 A comparison between criteria used for CGS and those applicable to Class I and III regions are given below:

Design Basis Tornado Characteristics

Maximum Wind Rotational Translational Speed (mph) Speed (mph) Speed (mph) Maximum Minimum Class I Region 360 290 70 5 Class III Region 240 190 50 5 CGS 360 300 60 - Radius of Maximum Rotational Speed (ft) Pressure Drop (psi) Rate of Pressure Drop (psi/sec) Class I Region 150 3.0 2.0 Class III Region 150 1.5 0.6 CGS 264 - 880 3.0 1.0

Wind and tornado loading criteria used in the CGS structural design are discussed in Section 3.3.

2.3.1.2.1.4 Strong Winds. The Hanford region experiences high wind speeds due to squall lines, frontal passages, strong pressure gradients and thunderstorms. The Hanford Reservation has experienced only one recorded tornado (June 1948) and has not been known to be affected by typhoons. No complete statistics are readily available which present frequency of occurrence of high winds produced or accompanied by a particular meteorological event.

However, the highest winds produced by any cause are tabulated for HMS in Tables 2.3-5 and 2.3-6. Figure 2.3-4 indicates the return probability of any peak wind gust, again due to any cause.

The speed-direction summary (Table 2.3-6) shows that daily peak gusts of at least 40 mph have occurred from all but four of the sixteen compass points indicated. The SW octant, however, accounts for 65 percent of such cases. The SSW octant accounts for 83 percent of daily peak gusts of 50 mph or over and 100 percent of those 60 mph or over. Since WNW and NW are the most frequently observed directions at HMS, they account for almost half of all daily peak gusts. However, less than 3 percent of these are at speeds of 40 mph or more. By contrast, 23 percent of daily peak gusts from the SSW and SW attain this speed. Although the winter season has a lower average wind speed than any other, it also has the greatest frequency of days with peak gusts 40 mph or over (10 percent). This compares with 8 percent for spring, 7 percent for fall, and 5 percent for summer. However, reflecting the frequent periods of stagnation in winter, this season also has the highest frequency of days with peak gusts under Peak wind gust data associated with thunderstorm activity are given in 2.3.1.2.1.2.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-8 10 mph (16 percent). This compares with 10 percent for fall and 1 percent for spring. In summer, such days are virtually non-existent with only one being tabulated in 1,102 days of record. About 60 percent of the days from May through August experience drainage winds of at least 13 mph from the west direction for at least two hours daily during the period of 1600 to 2400 PST.

The annual extreme fastest mile of wind speed* for a given region has been commonly used as the best available measure of wind for design purposes (Reference 2.3-9). The standard reference speed level is normally chosen at the 30-ft elevation, and wind speed is assumed to vary with the one-seventh power of height.

All CGS structures have been designed to withstand a basic wind (fastest mile) velocity, including gusts of 100 mph at an elevation of 30 ft above the site grade. This design speed value is conservative for the CGS site since the 100 year return period peak gust as shown in Figure 2.3-4 at HMS is 86 mph at an elevation of 50 ft (as given in Tables 2.3-5 and 2.3-6 at that level peak gusts have not exceeded 80 mph during the period 1945 to present). The 100 year return period fastest mile of wind would be less than 86 mph since by definition gust velocity divided by an appropriate gust factor provides the velocity of the fastest mile of wind. Although not recorded in historical records the 100 year fastest mile of wind can be expected to be in the range of 66 to 78 mph. These values are based on the application of gust factors of 1.3 and 1.1 (Reference 2.3-10) for gusts of one and 10 sec durations** respectively to the estimated historical value of 86 mph.

2.3.1.2.1.5 High Air Pollution Potential (APP) and Dust Storm Potential. Larson (11) has concluded that "consideration of the general weather parameters indicates a significantly high average annual APP over southeastern Washington." Holzworth (12) has estimated that the mean maximum January mixing depth in the Hanford area is about 250 meters, which is nearly the lowest in the contiguous United States, and for July about 2,000 meters. Hosler (13) has indicated a significantly high frequency of low-level inversion in winter over this area - on the order of 43 percent with bases below 150 meters. The occurrence of very stable and moderately stable conditions between the surface and 60 meters in winter at the Hanford Meteorology Tower is 66.5 percent.

Stagnation is defined by Huschke (14) as "the persistence of a given volume of air over a region, permitting an abnormal buildup of pollutants from sources within the region". Defining the establishment of stagnation as an uninterrupted period of daily average wind speed of 5.0 miles per hour or less and/or a peak gust of 15 miles per hour or less, Jenne (15)

• Fastest mile of wind is generally defined as either the fastest speed associated with 1 mile of passing wind or fastest observed 1 minute wind speed. ** According to Huschke (Glossary of Meteorology, 1959), the duration of a gust is usually less than 20 seconds.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-9 compiled a 15-year summary of Hanford stagnation periods covering the months of November through February (1947-48 through 1961-62). Both of the two most notable Hanford stagnation periods experienced during this time occurred in November and December 1952. The first period was from November 15 to December 3 (19 days). Then, after five days of ventilation, stagnation set in again December 9 and lasted through December 28 (20 days). Average wind speeds during the two periods were respectively, 2.6 and 2.9 miles per hour. Eleven days during the first period and eight during the second had peak gusts under 10 miles per hour. One day during the first period and two during the second had average speeds less than 1.0 miles per hour with peak "gusts" of 4 miles per hour. There were 13 days of fog in each period.

Although stagnation lasting for 20 days can be expected only one season in twenty, a 10-day stagnation period can be expected every other season. Only one season in three will fail to produce a stagnation period of at least eight days.

Air quality in the Hanford area, in terms of sulfur dioxide, nitrogen dioxide, and suspended particulates, is routinely measured by the Hanford Environmental Health Foundation. (18,29)

For the year 1971, SO2 measurement in Richland averaged less than 0.02 ppm. At other sampling stations, the concentrations were below the detection limit of 0.01 ppm. In 1974, all 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> sequential samples of SO2 measured in the vicinity of Richland, North Richland, and Hanford 300 Area had concentrations below the detection limit of 0.005 ppm which is 25% of the annual average ambient air standard of 0.02 ppm. The 1971 and 1974 measurements for NO2 and suspended particulates are shown below: Air Quality Measurements-Annual Averages for 1971 and 1974 (18, 29* ) (these data are based on 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> integrated samples) NO2 (pom) Location No. of Samples Max. Min. Avg. Richland (747 Building) 49 6.8 0.06 0.86 Opposite Richland 170 0.019 <.001 0.005 (Hobkirk Ranch) ( 78) (0.022) (0.001) (0.006)

Opposite N.

Richland 157 3.0 <.001 0.024

• Concentrations in parentheses are for 1974. ** High value due to a local dust storm.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-10 (Gilliam Ranch) (130) (0.020) (0.001) (0.006) Opposite 300 Area 170 0.025 0.001 0.005 (Sullivan Ranch) ( 77) (0.014) (0.001) (0.005)

Ringold 166 0.028 0.001 0.006 (Keys Ranch)

White Bluffs 149 0.028 0.001 0.006 (McLane Ranch) Suspended Particulate (g/m+3)

Location No. of Samples Max. Min. Avg. Richland (747 Building) 42 (125) 440 (572)** 25 ( 8) 120 ( 57) Opposite Richland - - - -

(Hobkirk Ranch)

Opposite N. Richland - - - -

(Gilliam Ranch)

Opposite 300 Area - - - - (Sullivan Ranch)

Ringold - - - - (Keys Ranch)

White Bluffs - - - -

(McLane Ranch) The major cause of air pollution in the Hanford area is dust occurring during windy periods. The most significant sources are cultivated fields in the surrounding area. A limited amount of information is available regarding atmospheric dust loading in the Hanford area. Hilst and Nickola (16) conducted limited dust investigations over a range of wind speeds and to heights of 400 feet in the Hanford area. A portion of their findings is presented in Figure 2.3-5. Other investigations which have been made in the Hanford area and reported by Sehmel and Lloyd (17) demonstrate the dependence of airborne concentrations on wind speed as shown in Figure 2.3-6.

Measurements of the particulate burden in air at a specific observation point in the 200 Areas at Hanford showed values of around 100 micrograms per cubic meter of air when the wind was less than 8 mph. The particulate content increased when higher winds were present, averaging 1,000 micrograms per cubic meter with winds of 12 mph, and 3,000 micrograms per cubic meter with winds of 16 mph.

Additional considerations regarding the August 11, 1955 and January 11, 1972 dust storms shown in Figures 2.3-5 and 2.3-6 and other climatological dust storm characteristics at Hanford are contained in the following paragraphs.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-11 2.3.1.2.1.5.1 Evaluation of August 11, 1955 and January 11, 1972 Dust Storms at Hanford. The wind speeds at 1.25 ft., 50 ft. and 400 ft. heights for the August 11, 1955 observation period were 14, 24, 31 mph respectively. Figure 2.3-5 represents atypical conditions for the site region. The case was originally selected for study as a situation with considerable airborne dust conditions compared to average conditions. A Hanford climatological summary of dust storms is given in Table 2.3-40 for 1953-1970 (30). Dust dependence on wind speed and direction (50 ft.) at the Hanford Meteorological Station is given in Table 2.3-41 for the same period (30). Approximate values of dust concentrations are computed based on an empirical relationship using visibility observations (31). The relationship is C656v1.25mg/m3 where V is horizontal visibility in km. This is based on data from the Great Plains with visibilities 7 to 9 miles and wind speeds greater than 12 mph. Hourly weather observations at the Hanford Meteorological Station were used as input criteria to define a wind resuspension or dust storm period. Hours satisfying dust storm criteria at Hanford (1953-1970) had either visibilities less than 7 miles and dust reported, or visibilities between 7-14 miles, wind speeds greater than 5.8 m/s, and relative humidities less than 70%. Since the above empirical concentration - visibility relationship was based on observed dust concentrations at approximately 5-6 feet above the surface, any measured dust data should be interpolated to that height when comparing the measurements to the calculated 1953-1970 results of Table 2.3-41. (30)

The frequency of the hourly data satisfying the dust storm criteria at Hanford is given in Table 2.3-42. (30)

The August 11, 1955 dust storm has an interpolated 5-ft value of 17 mg/m3 compared with the climatological average of about 7 mg/m3. Further inspection of the climatological values in Table 2.3-41, supports a conclusion that the storm is an example of the more severe type of dust storm that occurs in this region.

Care must be taken in interpretation of Tables 2.3-40 to 2.3-42 to allow for certain limitations. Estimates based on visibilities and/or wind speeds outside the range used in formulation of Equation 1 are of unknown reliability. The average visibilities within each wind speed class were within the range of empirical validity except for the high wind cases. Another source of errors is the fact that the visibility observations are taken at specific times and are not hourly averages. Considering these limitations Tables 2.3-40 to 2.3-42 may be taken to represent overall aspects of the Hanford dust storm climatology. Individual values must be considered approximate estimates - particularly those based on only a few data points.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-12 The extreme value in Table 2.3-41 in the 53 to 66 mph class (988 mg/m3) represents a single observation of 0-1/16 miles visibility for a few minutes. Typically at the onset of a dust storm very low visibilities with high winds occur for a few minutes. The very limited visibility and high winds for such a period were coded for the data for that hour. The station log reveals that five minutes after the onset of this dust storm, the winds had dropped to 37 mph and visibility was 3/8 mile. The phenomenon was generated by a thunderstorm passing close to the station. Hence, the extreme value in Table 2.3-41 represents an occurrence of very short duration which was the onset of a dust storm that had a duration of about one hour. Qualitative observation indicates that this is not an atypical scenario. Over the 40 minute duration of the storm, the average calculated average dust concentration was 60 mg/m3. It should be noted, however, that the onset concentration (988 mg/m3) is of unknown validity because it is calculated from a visibility value for which the empirical model has not been validated.

The visibility during the January 11, 1972 storm was initially less than one mile, changing to four miles during the last half hour of the reported episode. The January 11, 1972 dust storm had winds at 50' WSW in the range 31 to 43 mph. Wind storms with peak gusts recorded at 50' on the Hanford Tower during this period have a three to four year return period at Hanford.

Actual particulate loading depends on other factors such as surface conditions and atmospheric stability. Hence, the wind gust return period does not necessarily apply to particulate loading although it is reasonable to assume the return period is not less than that for wind.

Detailed estimates of the particulate size and total mass concentrations cannot be accurately made for the January 11, 1972 dust storm as a result of the lack of any particle size distribution data. In addition, only one height of mass concentration datum (189 mg/m3 at 0.2m) was made in the steep gradient region of the vertical profile. An indication of size distribution and mass loading profiles can be obtained from other data collected at Hanford. Sehmel (32) reports an April 1972 storm which has mass loadings near the surface which are similar to the January 11, 1972 storm. Although adjacent meteorological observations are not available for this episode, the fact that the mass loadings at the lower levels are of the same order as the January 11, 1972 dust storm provides a basis for comparison of the storms. The April 1972 storm has well documented mass loading profiles as a function of particle size. The table shown below contains the profiles of airborne soil concentrations as a function of particle diameter for the dust storm. These are based on optical measurements for smaller particles (.16 to 5 m) at 0.9m and, impacter-cowl measurements for larger particles (1 to 230 m) at the indicated heights. The mass loading is dominated by the larger particle data.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-13 Soil Mass Loading for the April 1972 Dust Storm (mg/m 3) Particle Height (m) Diameter Range ( m) 0.3 1.0 2.0 3.0 10. 32. 0.9 - 5.0 0.21 0.11 *

• 0.058 .0038 5 - 20 0.83 0.28 0.26 .25 0.070 .0056 20 - 60 14. 4.4 2.9 1.5 .81 .29 60 - 240 220. 6.6 2.8 1.3 .19 .11 Total 235 11.4 6.0 ~3.1 1.13 0.41 Comparison of the dust loading of 6.0 mg/m3 at 2 meters with the climatological summaries in Tables 2.3-41 and 2.3-42 indicates that this is a typical dust storm for the region.

The particle size distribution for the August 11, 1955 storm is shown in the following table for comparison.

Airborne Dust Loadings of Particles Greater Than 0.9 For August 11, 1955 Dust Storm (mg/m3) Particle Height (m) Diameter Range (m) 0.38 2.0 15.2 30.5 0.9 - 5.0 0.015 0.012 0.012 0.0079 5 - 20 0.39 0.32 0.23 0.17 20 - 60 3.1 2.2 1.1 0.77 60 - 240 18. 12.0 2.3 0.78 Total 22. 14.5 3.7 1.7 The April 1972 dust storm has higher mass loadings near the surface in all size ranges. The August 11, 1955 dust storm had higher dust loadings above 1 to 2 m heights in the ranges greater than 5 diameter. One interpretation of these profiles is that the 1972 storm had a source nearby and the 1955 data represents advection of airborne dust from more remote sources (33).

2.3.1.2.1.5.2 Hanford Dust Storm Climatology for Design and Operating Bases. The Hanford climatological study of dust storms for 1953-1970 (30) (discussed in the previous subsection) was re-examined for the purpose of establishing the "worst case" dust storm which may have occurred during that period (33). The worst case dust storm, i.e., that storm which had the largest calculated time integrated dust loading (mg-hr/m3), is considered to be

• No value in reference.

COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000 LDCN-98-117 2.3-14 160 mg-hr/m2, duration of 18 hr, and average dust loading of 8.9 mg/m3 at a height of 5 to 6 ft. The design basis dust storm is bounded by a postulated volcanic ashfall event (see Section 2.5.1.2.6) in the evaluation of the design and performance of HVAC systems and diesel generators. Results of this worst case dust storm investigation are listed below. As mentioned above, these loadings would apply for a height of 5 to 6 feet above the ground. Detailed Estimates of the Dust Loadings for the Six Worst Storms Based on Surface Observations of the Hanford Meteorology Station, 1953-1970 Storm Number Total Dust Loading (mg-hr/m3) Actual Duration (hr) Average Dust Loading (mg/m3) 1 40* 0.67 60 2 100 1.0 100 3 160 18** 8.9 4 44 2.6 17 5 90 3.1 29 6 80 7 11 The worst storm of these was storm No. 3. While it was also shown in this study that once a given dust storm terminated, there existed a 5% probability that another one would occur within 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> and a 50% probability that another one would occur within 30 days, none of the above six worst case dust storms had occurred within 30 days of each other. Most had occurred in different years during the 1953-1970 study period.

The dust loading for storm No. 3 is conservative in terms of its being considered as the worst case storm for use in plant design evaluations. As a result of the shorter storm durations of the measured August 11, 1955, January 11, 1972, and April 1972 dust storms, their time integrated dust loadings at 5-6 feet above the ground are not worse than that computed for storm No. 3 (33).

2.3.1.2.2 Design Snow Load

The American National Standards Institute (ANSI) in "Building Code Requirements for minimum Design Loads in Buildings and other Structures" (19) provides weights of 100-year return period ground level snow packs for the site region. The ANSI (Reference 2.3-19) value

• Value is less than actual dust loading as a result of less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> duration. ** The detailed investigation yielded 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> as opposed to a range of 1-16 hours given in Table 2.3-40 of 2.3.1.2.1.5.1 for the range in duration of dust storms using the same 1953-1970 data.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-15 of 20 lb/ft2 was used as the design snow load for all CGS structures.* Assuming a specific gravity of 0.1 or snow density 6.24 lb/ft3, this design value corresponds to a snow depth of 3.2 ft. The above snow load is conservative for the site as snow depth seldom exceeds six inches, and the greatest depth of 24.5 inches was recorded in February 1916. (4) The weight of the 48-hour probable maximum winter precipitation can be determined from the data presented in Table 2.3-3. Since the greatest snowfall in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was 10.2 inches (February 1993) and a record depth of approximately 12 inches lasted four days (December 1964) these depths would correspond to snow loads of 5.3 and 6.24 lb/ft2 respectively. 2.3.1.2.3 Meteorological Data Used for Evaluation of Ultimate Heat Sink The ultimate heat sink is evaluated in Section 9.2.5.

The meteorological data presented in Figure 2.3-7 and Tables 2.3-1, 2.3-5, and 2.3-7a-7h was used to evaluate the performance of the CGS spray ponds in 9.2.5 with respect to (1) maximum evaporation and drift loss and (2) minimum water cooling. In accordance with Regulatory Guide 1.27, Rev. 1 "Ultimate Heat Sink for Nuclear Power Plants", the worst one-day and 30-day periods of meteorological record which resulted in minimum heat transfer to the atmosphere were established. The worst recorded 30-day period (30-day average) of maximum difference between dry-bulb and dewpoint temperature and highest simultaneously recorded wind speeds which resulted in the maximum evaporation and drift loss were also established.

Climatological moisture and temperature data presented as a function of time of day for each month in Figure 2.3-7, and wind statistics given in Table 2.3-5 were used to establish the maximum initial pond temperature for the ultimate heat sink analyses in 9.2.5. It was determined in 9.2.5 using these meteorological data, solar radiation formulas contained in ASHRAE Handbook of Fundamentals, and techniques outlined in the John Hopkins University Report "Cooling Water Studies" (Edison Electric Institute Research Report No. 5, Project RP-49, November 1969) that the month of July contained the worst average meteorological data which resulted in the maximum initial pond temperature.

The worst day meteorological data was considered to be the given combination of meteorological parameters in a particular consecutive twenty-four hour period which resulted in the worst pond thermal performance. The following recorded episodes of extreme wet bulb temperatures experienced at the CGS and/or HMS sites were evaluated in 9.2.5 to establish the worst pond thermal performance:

1) August 7-9, 1972 at CGS and HMS, presented in Table 2.3-7a (20),

• Ice loading is included in this CGS estimate.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.3-16 2) July 4-12, 1975 at CGS, presented in Tables 2.3-7b to 2.3-7e from the onsite FSAR meteorological monitoring program,

3) August 4, 1961 at HMS, presented in Table 2.3-7f (21).

The meteorological conditions which occurred on July 10, 1975 at CGS resulted in the worst pond thermal performance as determined in 9.2.5.

The following worst month meteorological data were used in 9.2.5 to establish the second through thirtieth day worst pond thermal performance and worst 30-day drift loss and evaporation (Reference 2.3-21):

a) July 9 - August 8, 1961 at HMS, presented in Table 2.3-7a (minimum heat transfer) b) July 2 - August 1, 1960 at HMS, presented in Table 2.3-7h (maximum evaporation and drift loss)

Diurnal variations in dry bulb and wet bulb temperatures for both 30-day periods assumed that the hourly temperature variation approximated a sine wave of one cycle in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Reference 2.3-21). The average wind speeds during both 30-day periods was approximately 5.5 mph. The root mean square average of the hourly wind speed data for the 30-day mass loss period is 6.91 mph.

For conservatism in the thermal analysis, the worst day data for thermal performance was assumed to repeat in the analysis until pond temperature peaked (three days repetition). For conservatism in the mass loss analysis, an upper bound curve was fit to the drift loss data taken during spray pond testing. The drift loss value was obtained from this curve. See 9.2.5 for details.

2.3.2 LOCAL METEOROLOGY

2.3.2.1 Data Comparisons The local meteorology prior to CGS plant operation at the CGS site can be described from FSAR meteorological data procured during the period April 1, 1974 to March 31, 1976 from the permanent onsite 7-ft and 245-ft meteorological towers. Data collected from the 245-ft CGS tower had been used for the short-term (accident) and long-term (routine) diffusion estimates. Onsite meteorological data were also obtained from a temporary 23-ft tower which commenced operation in April 1972 for the purpose of determining optimum cooling tower geometric orientation for performance during high wet bulb periods. The 23-ft meteorological tower data were also used with other regional data to establish the potential impact of proposed mechanical draft cooling tower atmospheric releases in the vicinity of CGS COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-17 (Reference 2.3-22). The permanent tower data have been compared where appropriate and possible, with simultaneously recorded and historical data obtained from the Hanford Meteorological Station (HMS) for the purpose of documenting the representativeness of the two years of onsite meteorological measurements. For the months of April through August 1974, comparisons have also been made with data from the onsite temporary tower; this tower and instrumentation were dismantled in September 1974. Monthly and annual average comparisons between simultaneously recorded and historical data for all the aforementioned meteorological tower sites have indicated that agreement between the data sources is reasonably good. When comparing sources of data, it should be recognized that at any given time, significant differences can exist between the reported meteorological conditions at the CGS and HMS sites (see, for example, Table 2.3-7a). Differences in the frequencies of occurrence of various meteorological conditions at a given site can also exist from year to year or from one elevation to another elevation at a site for coincident observation times. Any discrepancies between summarized data sources can also be attributed (in addition to site separation and instrument height above ground) to differences in types and accuracies of instrumentation used and procedures considered for acquiring, processing, and analyzing raw meteorological data. Details regarding the onsite meteorological measurement program are presented in 2.3.3.

For the following data comparisons, the following definitions are used:

CGS Data obtained from the permanent 7' and 245' towers at the CGS site; summarized here for April 1, 1974 - March 31, 1976. CGS (temp). Data obtained from the temporary 23' tower at the CGS site; summarized here for April 1, 1974 - August 31, 1975.

HMS: Data obtained from the Hanford Meteorological Station; used here for April 1, 1974 - March 31, 1976.

HMS (hist): Data obtained from the Hanford meteorology tower at the Hanford Meteorological Station, used here for various periods identified in the data comparison listings. The source is AEC Research and Development Report "Climatography of the Hanford Area", June 1972, BNWL-1605.

Wind Variable: At CGS an hour of data which contains less than 15 minutes of any one direction sector; at Hanford, the same but for 20 minutes. Data obtained at the 33 foot (10 meter) elevation is presented since these data have been subsequently used in the site diffusion studies for postulated ground-level release cases.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-18 Wind Calm: At CGS, an hour of data for which the average speed is 0.22 miles per hour or less; at Hanford, average speed less than 1 mph (as decided by weather observer, corresponds to no motion of strip-chart recorded pen). Sense of Delta T: Positive values imply relative stability, negative values imply relative instability.

The first annual cycle of CGS onsite meteorological data which covered the period April 1, 1974 through March 31, 1975 has been presented in detail. Local meteorological data collected during the second annual cycle (April 1, 1975 through March 31, 1976) generally portrayed the same characteristics as indicated by comparison with the first annual cycle data. Except for the high wet bulb episode experienced at CGS during July 1975 (refer to 2.3.1.2.3 and 2.3.2.3), no monitored onsite data proved to be more severe in terms of the design and operation of CGS than those data presented in 2.3.1.2. Hence, only the second annual cycle monthly averages have been presented in Table 2.3-8a which summarizes the two years of monitored on-site data with concurrently measured and historical HMS data. Any significant differences noted between first and second annual cycle onsite data and concurrently measured CGS and HMS data are discussed in 2.3.2.1. Otherwise, conclusions stated herein for the first annual cycle of data similarly apply to the second annual cycle data. It is observed in Table 2.3-8a that any year to year differences in the summarized monthly mean meteorological data at tend to parallel the differences in the means summarized for the HMS site for corresponding months during the two year monitoring period.

Summaries of joint frequency distributions of wind direction and wind speed by atmospheric stability class and results from accident and routine diffusion estimates for both annual cycles of CGS onsite meteorological data are presented in subsequent sections.

Magnetic tape files of the two years of hourly onsite data have been transmitted to the NRC.

2.3.2.1.1 Winds

Table 2.3-8b presents monthly and annual CGS joint wind speed and direction data for the first annual cycle of monitoring. Similar data for the HMS site are given in Table 2.3-9. The CGS data presented in the above tables were collected at an elevation of 33 feet above local grade for the one year period of record whereas the HMS historical data were collected at an elevation of 50 feet above local grade during the period 1955 through 1970 (HMS is approximately 280 feet higher in elevation than the CGS site). Additional wind direction frequency statistics are presented in Table 2.3-10.

The CGS 33 ft and CGS (temp) 23 ft wind direction data given in Table 2.3-10 have similar distributions of direction frequency and show a bimodal wind direction distribution from approximately South and also Northwest. These distributions differ from that given for the HMS site where the direction distribution displays a single peak at approximately West COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-19 Northwest to Northwest. Further, the wind direction distribution at the CGS site is much more uniform around the compass than it is at the HMS site. The differences in these distributions may be attributed to the influence of terrain features, causing variability of air flow at the CGS site. This conclusion is strengthened by the observation that the CGS monthly wind frequency distributions are similar through-out the period of data acquisition. Tables 2.3-11 and 2.3-12 provide the 20 longest occurrences of wind direction persistence at CGS for an elevation of 33 feet. Table 2.3-11 shows persistence in one (22.5 degree) sector while Table 2.3-12 shows persistence within two (45 degrees) adjoining sectors; the corresponding stability class distributions and average wind speed within each stability class are also provided.

It is noted that the majority of the periods of high direction persistence at CGS are associated with unstable, neutral, and moderately stable atmospheric conditions and moderate to strong wind speeds. These represent relatively good diffusion conditions. Table 2.3-12a summarizes the longest persistences of wind direction in one and two sectors at CGS measured during the first and second annual cycles. The annual frequency and duration of episodes of high wind direction persistence at CGS depend upon the frequency and intensity of weather systems which result in regional large scale gradient flow. For example, during the first annual cycle, the longest persistence in one and two sectors lasted 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> (NW) and 26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> (NW, NNW) respectively. During the second annual cycle, the longest persistence in one and two sectors lasted 33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> (NNE) and 35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br /> (N, NNE) respectively. Whereas the longest persistence in one sector during the first annual cycle lasted 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />, the duration of the first three longest persistences in one sector during the second annual cycle (33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> from NNE, 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> from SSW, and 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> from NW) exceeded that longest duration.

Table 2.3-13 presents monthly frequency distributions and averages of wind speed measured at the CGS and HMS sites. Considering site separation, elevation of sensors, and instrumentation and procedural differences, the CGS wind data appear meteorologically reasonable and demonstrate consistency among data sources.

2.3.2.1.2 Moisture and Temperature

Diurnal variation and averages of dry-bulb, wet-bulb, and dew-point temperatures for the first annual cycle of monitoring at the CGS and HMS sites are given in Tables 2.3-14 to 2.3-16. Tables 2.3-17 to 2.3-19 present frequency distributions of dry-bulb, wet-bulb, and dewpoint temperatures, summarized for the first year of CGS site observations. Table 2.3-20 contains additional climatological summaries of monthly normals and extreme values of temperature and humidity measured at HMS.

Considering the 280 ft difference between the CGS and HMS sites and assuming a dry adiabatic lapse rate of 5.48°F/1000 ft, one can expect a temperature difference of about 1.5°F between the dry-bulb temperature data measured at both sites.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-20 Higher monthly average wet-bulb and dewpoint temperatures occurred at CGS since the CGS site experienced air of slightly higher moisture content than the HMS site. The higher moisture content may be attributed to Columbia River proximity and irrigation of the fields in the vicinity of CGS. This conclusion is strengthened by the fact that moisture enhancement at CGS was at a minimum for the months of January, February, and March during the first annual cycle of CGS site observations.

During the second annual cycle of monitoring, it was observed that the CGS site experienced air of essentially the same moisture content as did the HMS site. The absence of the moisture enhancement at CGS, which was noted during the first annual cycle, may be attributed to reduced evaporation from the proximate river and irrigated fields. The periodic occurrences (during the second annual cycle) of cooler dry-bulb temperatures and precipitation deficits when high dry-bulb temperatures prevailed may have resulted in reduced evaporation.

2.3.2.1.3 Monthly Precipitation

Diurnal variation of precipitation intensity at CGS and monthly total precipitation at CGS and HMS for the first annual cycle of monitoring are given in Table 2.3-21. Frequency of occurrence of precipitation intensity data from April 1974 through March 1975 at CGS are presented in Table 2.3-22. Frequency of occurrence of wind speed and direction versus precipitation intensity for the same year of data is given in Table 2.3-22a. The data show that the CGS site experienced less precipitation than did the HMS site. The difference can be attributed to site separation and the incidence of precipitation falling in the form of showers of quite limited spatial extent. The precipitation deficit at CGS may also result from a rain shadow effect from Rattlesnake Mountain. A precipitation gradient is known to exist along the slope of this terrain feature.

2.3.2.1.4 Fog

Fog data are unavailable for the site. Although fog has been observed in every month of the year at HMS, it is essentially a seasonal phenomenon with 95 percent of it observed during the months of November through February. Inclusion of March and October fog would increase this percentage to 99.7. Tables 2.3-23 and 24 summarize the duration and persistence statistics for fog occurrences at HMS. Because of the relative proximity of the site to the Columbia River, it is expected that the frequency of occurrence, intensity and duration of fog would be somewhat greater than these data indicate (refer also to 2.3.2.1.5).

Most fog in the Hanford region is of the radiation type and hence occurs mostly in conjunction with light wind, inversion or stable atmospheric conditions. The occurrence of fog at the site can therefore be considered as one visual indicator of poor atmospheric diffusion conditions. Advection and frontal fogs occur occasionally at both HMS and the Tri-City stations of Richland and Pasco. In addition, at Richland and Pasco, there are occasional occurrences of COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-21 steam fog from the Columbia River. These are not usually deep and many would be classified as ground fog.

Statistics on fog persistence are limited to those at HMS. Although most dense (visibility 1/4 mile or less) fogs do not last longer than 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, a few run for much longer periods as shown in Table 2.3-23. After a period of fog, there frequently follows a period of atmospheric stagnation with a low stratus overcast and light winds. Such conditions may persist for many days.

2.3.2.1.5 Stability Summaries For the purposes of comparison, the t (temperature difference) and sigma theta (standard deviation of the horizontal wind direction fluctuations) stability classifications which are used in diffusion studies at Hanford are given below with the t "Pasquill" and sigma theta classes identified in NRC Regulatory Guide 1.23: REGULATORY GUIDE 1.23 Pasquill Class t/Z (F/200 FT) Sigma* Theta Extremely unstable A Less than -2.1 25.0 Moderately unstable B -2.1 to -1.9 20.0 Slightly unstable C -1.9 to -1.6 15.0 Neutral D -1.6 to -0.6 10.0 Slightly stable E -0.6 to 1.6 5.0 Moderately stable F 1.6 to 4.4 2.5 Extremely stable G greater than 4.4 1.7 HANFORD RESERVATION CLASSIFICATION Pasquill Class t/Z (F/200 FT) Sigma Theta Groupings** (Degrees) Very unstable Less than -2.5 greater than 22.5 Unstable -2.5 to -1.5 25.5 to 17.5 17.5 to 12.5

• Period of 15 minutes to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. ** Note that these sigma theta groupings do not necessarily correspond to any particular Hanford Stability Class on the left, i.e., there can be a maximum of 35 group combinations of t/Z and sigma theta although some combinations are unlikely to occur.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-22 Neutral -1.5 to 0.5 12.5 to 7.5 7.5 to 3.75 Moderately Stable 0.5 to 3.5 3.75 to 2.1 Very Stable greater than 3.5 less than 2.1 Joint frequency distributions of wind speed and direction by atmospheric stability class (temperature difference and sigma theta combinations) for the first and second annual cycles of monitoring are presented in Section 2.3.3. Percent frequency of occurrence of stability (t distribution) at CGS and HMS are given in Table 2.3-25. Although the heights over which t was measured are similar for both sites, it is observed in Table 2.3-25 that CGS experiences air of greater thermal stability than HMS. This discrepancy between site stabilities may be accounted for because of terrain differences. The CGS site serves as a drainage basin for relatively cool air (especially at night), resulting in strong thermal low-level stratification and the formation of persistent temperature inversions. This conclusion is strengthened by the observation that the difference between the sites is much more pronounced during July, August, September and October than during all other months. It is during these months that pooling of relatively cool air is at a maximum due, partly, to minimum cloudiness and therefore, enhanced nocturnal cooling occurs at the ground. It is noted in Table 2.3-25 that the percent frequencies of stability types for both annual cycles of monitoring at CGS are very similar. Frequencies of occurrence of t and sigma theta versus time of day for the first year of onsite meteorological measurements are given in Table 2.3-26 and 2.3-27. Although frequency of occurrence and duration of inversion conditions were not analyzed for the site, stagnation and inversion information contained in 2.3.1.2.1.5 and 2.3.2.1.5 for HMS should be representative for the site (except for the fact that the above data indicates that CGS experiences a greater frequency of surface-based inversions than does HMS). Figure 2.3-8 shows probabilities of inversion persistence at HMS from 1952-1969 (2). 2.3.2.2 Potential Influence of the Plant and Its Facilities on Local Meteorology The shapes and sizes of the buildings erected on the plant site will produce a disturbed air flow which alters the initial distribution pattern and diffusion rates of plant release airborne contaminants. In the diffusion calculations this effect is considered.

Electrical power generation by steam turbines requires dissipation of large quantities of low grade thermal energy. Waste heat produced from the operation of CGS is dissipated by means of six circular mechanical draft cooling towers. These evaporative cooling towers release waste heat directly to the atmosphere in the form of sensible and latent heat. An extended visible plume consisting of liquid water droplets can occur principally during the winter months when periods of cold weather and high relative humidity prevail. Fogging is defined as occurring if visible plumes intersect the ground, buildings, or other elevated structures.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-23 Fog occurs naturally in this region, and any cooling tower fog is an extension of the naturally occurring phenomenon. When air temperatures of 0°C or lower prevail, the additional potential exists for icing on these surfaces. At times, small cumulus clouds could form above or remote from the plant, depending on the atmospheric temperature and moisture conditions in the first several thousand feet above the cooling towers. No significant environmental or atmospheric impacts arising from CGS cooling tower operation have been observed or are foreseen based on dispersion meteorological studies performed by Battelle Northwest Laboratories (Reference 2.3-22). Details covering potential environmental impacts arising from CGS cooling tower operation are given in the CGS Environmental Report.

2.3.2.3 Local Meteorological Conditions for Design and Operating Bases The regional long term meteorological conditions provided in Section 2.3.1.2 are applicable for use in establishing the plant design and station operating bases. Except for the high wet bulb episode experienced at CGS during July 1975 (refer to 2.3.1.2.3), none of the local short term meteorological data presented in 2.3.2.1 proved to be more severe in terms of the design and operation of CGS than those presented in 2.3.1.2. Data collected since January 1, 1984 form the revised long-term design and operating basis for dispersion calculation. 2.3.2.4 Topographic Description As shown in Figures 2.1-1 and 2.1-2, the plant is located at a grade elevation of 441 feet MSL in a basin area formed by the Saddle Mountains to the northwest, bluffs and hills rising to about 900 feet MSL to the north and east, the Horse Heaven Hills to the south and the Rattlesnake Hills and Yakima, Umtanum and Manastach ridges to the west. Topographic cross-sections plotted out to 10 kilometers by sector from the plant are given in Figure 2.3-9. Except for the cliffs toward the east across the Columbia River, the region within this circumference is basically flat and featureless and slopes gradually toward the Columbia River. Additional details regarding the regional topography and geology are given in 2.5. The effects of regional topography on local meteorology are discussed in 2.3.1.1, 2.3.2.1.1 and 2.3.2.1.5. The need to consider plume height relative to land elevations has been obviated by the assumption of a ground-level release for the accident and routine station release cases which are presented in 2.3.4 and 2.3.5. 2.3.3 ONSITE METEOROLOGICAL MEASUREMENT PROGRAM The permanent onsite meteorological data collection system in use since January 23, 1974 consisted of a 240 ft main tower, an auxiliary seven ft instrument mast, sensors with associated COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000 LDCN-99-000 2.3-24 electronics and recording devices, and a meteorological shelter. A 23 ft onsite temporary tower was also used during the period April 1, 1972 through August 31, 1974. The Battelle Memorial Institute, Pacific Northwest Laboratories, had been conducting a continuing two year program of acquisition, processing, and analysis of meteorological data for Energy Northwest Columbia Generating Station in a contractual arrangement with Burns and Roe, Inc.

The first and second annual cycles of reliable meteorological data were collected during the periods April 1, 1974 through March 31, 1975 and April 1, 1975 through March 31, 1976, respectively. The accuracy of these data had been established primarily through calibrations conducted at quarterly intervals as required through a formal program of quality assurance. The data were examined for meteorological reasonableness, after corrections were applied per the calibration Reports, through computer edit programs. No data were found to be unreasonable. The annual summaries were compared with the monthly summaries and all were found to be consistent. The computer summarization programs (identical for monthly and annual purposes) were tested at quarterly intervals by application to dummy data per the quality assurance program. (23) The computer calculation programs for x/Q were similarly tested. Comparisons between CGS meteorological data and concurrently measured and historical HMS data have been presented in 2.3.2.1.

2.3.3.1 Permanent Onsite Meteorological Tower and Instrumentation Characteristics The meteorological tower, which is located approximately 2,500 feet west of the CGS plant site with its base at 455' MSL, consists of a 240 ft high primary tower with a five ft mast extending above it. The primary tower is triangular in shape and of open lattice construction to minimize tower interference with meteorological measurements. Wind and temperature measurements were made at the top of the mast and at the 33 ft level. The dewpoint temperature was measured at the 33 ft level. At the lower level the instruments were mounted on an eight ft horizontal boom extending southwest of the tower. Wind and temperature measurements were also made at the top of a seven ft mast which was located approximately 80 feet southwest of the 245 ft tower.

Wind speed measurements were made using conventional cup anemometers (Climet Instruments, Model 011-1 Wind Speed Transmitter) which have a response threshold of about 0.6 mph and a distance constant of less than five feet. Over a calibrated range of 0.6 to 90 mph the accuracy of these instruments is +/- 1% or 0.15 mph (whichever is greater). Data collection on the 240 foot and seven foot towers was terminated on June 1, 1976 subsequent to the collection of two years of reliable tower data ending March 31, 1976, required for the CGS FSAR. Data collection on the Primary and backup towers began on July 1, 1984.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-25 Wind direction measurements were made using lightweight vanes (Climet Instruments, Model 012-10 Wind Direction Transmitter).

The response threshold of these vanes is about 0.75 mph, and their damping ratio and distance constant are approximately 0.4 and 3.3 feet, respectively. Dual potentiometers in the Wind Direction Transmitter produce an electrical signal covering 540° in azimuth with an accuracy of +/-3°. In addition, electronics had been included to provide signals which were proportional to the standard deviation of the wind direction fluctuations at each level.

Temperature instrumentation had been installed to provide measurements of both the ambient air temperature at the 245, 33 and 7 ft levels, as well as the temperature differences between these levels. The ambient air temperature and the temperature difference measurement systems were independent of each other to provide for reliability. Atmospheric stability delta - T classes were determined solely on the basis of the data from the electronic differencing bridge and not by subtracting the ambient air temperature measurements. All temperature measurements for both systems were made in aspirated radiation shields (Climet Instruments Model 016-1 or -2) using platinum resistance temperature detectors (Rosemount Engineering Co., Model 104 MB6ABCA). These instruments provided an ambient temperature range from

-30°F to +/-130°F and a temperature difference range of +/-15°F. The accuracy of the instruments is +/-.09°F in the measurement of temperatures and +/-0.18°F in the measurement of temperature differences.

The dewpoint temperature was measured at the 33 ft level of the tower using a lithium chloride dewpoint sensor (Climet Instruments, Model 015-12) housed in an aspirated radiation shield (Climet Instruments Model 016-2). Precipitation was measured at ground level using a tipping bucket rain gage (Meteorology Research Incorporated, Model 302) located about 40 feet west of the main tower. This instrument is accurate to within 1% at rainfall rates up to 3 in./hr and has a resolution of 0.01 in. The instrument building provided a semi-controlled environment near the tower to house the instrument electronics and record the data. Analog strip chart and digital magnetic tape recorders were used to provide redundant data recording capability. The primary data recording system was a seven-track digital magnetic tape recorder (Kennedy, Model 1600) which used 1/2 inch tape. Logarithmically time-averaged wind speed, wind direction, temperature, temperature difference and dewpoint temperature signals were recorded at five minute intervals. The time constant of the averaging process was five to ten minutes. The standard deviation of wind direction fluctuations during the preceding five minutes at each level and the total precipitation were recorded along with the wind and temperature information. All data, except the wind direction standard deviations, were also recorded on strip charts which provided a backup data record to enhance data retrievability. In addition, since the strip charts contained an essentially instantaneous record of the signal from each instrument, they provided a rapid means of identifying instrument malfunctions and were useful in system calibration. These strip charts and magnetic tapes were changed weekly.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-01-072 2.3-26 In summary, the total system accuracies for the measured meteorological parameters meet or exceed the following specifications:

air temperature +/-0.5°C temperature difference +/-0.2°C

humidity (dew point) +/-2.8°C wind speed 0.5 mph from 0.5 to 5 mph, +/-10% of reading above 5 mph per RG 1.97, Rev. 3. wind direction +/-5° These are verified by the end-to-end calibrations. Data recovery was better than 90%.

2.3.3.2 Quality Assurance Program To ensure the quality of the meteorological data collected by the monitoring system, an extensive quality assurance program had been instituted. This program covered all phases of meteorological monitoring from the initial instrument acquisition through the analysis of data. Periodic checks and calibration of the instrument systems and individual components had been instituted. These periodic checks ranged from daily inspection of the strip charts to semiannual calibration of the complete system. All checks, calibrations and maintenance were fully documented, including traceability of test and calibration equipment to the National Bureau of Standards where necessary. Once collected, the data were protected from loss to the maximum extent possible; the digital tapes were examined to identify possible instrumentation malfunctions; and the data were then copied onto two master tapes. The original weekly tape and one master tape were stored in vaults for safekeeping while the second master tape was used in the preparation of data summaries. Finally, to ensure proper operation of computer hardware and software, all computer programs used to summarize or analyze the data were checked quarterly using a standard data input. The computer output from these tests was then saved to document computer operation.

The various phases of the quality assurance program pertaining to the two years of permanent onsite meteorological monitoring and data processing are discussed in the following subsections.

2.3.3.2.1 Data Recovery During April 1, 1974 - March 31, 1976 The meteorological data acquisition system was put into operation during January 1974. Outages in the digital system precluded an initiation date for the acquisition of reliable data prior to April 1, 1974 because the processing of an inordinate amount of data from strip charts COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.3-27 would have been required. The data utilized in the production of the monthly and annual summaries have been obtained exclusively with the primary data recording equipment (magnetic tape digital system) since August 1, 1974. Recourse to data recorded on strip charts was required at times prior to August 1974 to assure, as viewed at the time, a recovery rate of 90% representative data as required by Nuclear Regulatory Guide 1.23. The percentages of monthly data read from strip charts is listed below:

April 1974 - 23.3%

May 1974 - 8.3%

June 1974 - 49.5% (W/S 33' - 59.1%)

July 1974 - 1.6%

From routine and anticipated causes (system maintenance and calibration) modest data losses were experienced on the order of 2% and 1.2% for the first and second annual cycles of onsite data collection respectively. A comparable amount, for some of the meteorological quantities, was caused by circumstances beyond Battelle's control (power outages, delay in receipt of spare parts, etc.). The percentages of missing annual data for various meteorological quantities are listed below:

April 1, 1974- March 31, 1975 April 1, 1975 March 31, 1976 Wind Speed 33' 4.0% 2.7%

Wind Direction 33' 4.0% 1.5%

Dry Bulb Temperature 33' 2.5% 1.2%

Wet Bulb, Dewpoint Temperature 33' 2.7% 1.2% Differential Temperature 33' - 245' 3.1% 1.5%

These percentages are representative of missing data for all meteorological quantities except precipitation. During the first annual cycle of monitoring, data recovery for precipitation was 100%. Precipitation data recovery was complete during the second annual cycle of monitoring, except possibly during December 1975 when a sand plug was discovered in the rain gauge funnel. As a result, it was estimated that less than 0.1 inch of precipitation was not recorded during that month. For the first annual cycle of monitoring, the data recovery rate was 96% or better for all meteorological quantities; this rata was 97% or better during the second annual cycle of monitoring.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-28 2.3.3.2.2 Maintenance and Calibration Assurance of quality data rests primarily with the calibrations performed at quarterly intervals and reported for July and October 1974; January, April, July and October 1975; and January and April 1976.

All evidence to date obtained through formal calibrations and routine daily and weekly inspection had demonstrated that the meteorological system remained electronically stable in terms of obtaining data of sufficient quality to meet the requirements in Regulatory Guide 1.23. The calibration corrections required are tabulated in the response to NRC question 6.4 on the FER. The calibrations established any system inaccuracies by comparisons to standards. These inaccuracies were corrected by appropriately adjusting the data at the data processing stage as opposed to adjusting the system electronics. The calibrations before and after each calibration period were used to determine if corrections were required to account for drift or if offset had occurred. No drift corrections were required. The offsets were discussed in the FER response. For corrections that were not constant throughout the range of a given parameter, a calibration table or curve was used to correct the data. Calibration corrections were applied as part of the computer programs used to edit and translate the data from the original raw-data tapes to a master file of hourly values.

2.3.3.2.3 Data Processing and Analysis

For the two years (1974-1976) of onsite FSAR meteorological monitoring at CGS, all data (magnetic tape and strip chart where required) were run through computer edit programs. No data were found to be unreasonable except for known causes as documented in Nonconformance Reports. Data corrections, per the Calibration Reports, were applied in the computer programs. Summarization of data has been accomplished only at such times as calibration information was available to bracket in time the acquired data.

The data for each hour is represented by an average of the data for the last 30 minutes in the hour. The averaging period of 30 minutes was selected for consistency with 1) the data used to formulate the Hanford Diffusion Model used for routine and accident dose calculations, 2) the recommendations in Regulatory Guide 1.23, and 3) computational economy. The only exception was wind direction which was averaged over one-hour to facilitate the formulation of wind direction persistence summaries. One thirty-minute period per hour is considered adequate for climatological summaries consisting of averages of many hours. In addition, x/Qs based on thirty-minute averages will be conservative for estimates of the one-hour averages. All data products were based on these "hourly" averages.

Wet bulb from the permanent tower was obtained from standard psychrometric formulas presented in the Smithsonian Meteorological Tables, 1971 issue.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-29 The above descriptions relate to data collected and used in FSAR submittals through Amendment #36. Data collection and processing since July 1, 1983 is described in 2.3.3.2.4. The Kennedy Tape Recorder has been replaced with a floppy disk recorder for increased reliability.

In several of the monthly summary reports, the computer programs as applied to dummy data have been compiled as called for in the Quality Assurance Manual (Reference 2.3-23) for the purpose of documenting proper programming and proper computer performance.

These computer computations have been verified with hand calculations made with the dummy data. The computational programs for x/Q were similarly tested.

2.3.3.2.4 Meteorological Monitoring Program During Plant Operation The meteorological tower, which is located approximately 2500 ft west of the CGS plant site with its base at 455 ft msl consists of a 240-ft high primary tower with a 5-ft mast extending above it. This tower is triangular in shape and of open lattice construction to minimize tower interference with meteorological measurements. Wind and temperature measurements are made at the top of the mast and at the 33-ft elevation by duplicate sets of instruments. One set of instruments is the primary measurement system and the other set constitutes the backup instrumentation. The lower elevation wind speed/direction instruments are mounted on a horizontal boom, extending southwest of the tower.

Wind speed and wind direction measurements are made with a single instrument package that combines a wind speed propeller on the leading (upwind) end of the instrument and a wind direction vane, or tail, on the opposite end. Wind speed measurement range is 0.5 to 90 mph with a threshold sensitivity of about 1 mph. The wind direction measurements are made by the wind passing over the wind vane portion of the instrument. In addition, electronic modules process the data from these instruments and provide output data which is proportional to the standard deviation of the wind direction fluctuations over 15 minutes.

Temperature instrumentation provides measurements of the ambient air temperature at the 245 and 33-ft elevations. Temperature measurements are made in aspirated radiation shields using platinum RTDs. These instruments provide an ambient temperature range from -50°F to +150°F. Each set of RTDs (one from 33 ft level and one from 245 ft level) are calibrated together in the same temperature bath and electronic modules process the data from these instruments to provide a temperature difference range of +/-15°F.

The relative humidity is measured at the 33-ft elevation of the tower using an intercap sensor with a range of 0 to 100% RH housed in an aspirated radiation shield. Precipitation is measured at ground level using a tipping bucket rain gauge located about 40-ft west of the main tower. The barometric pressure is measured by a pressure transmitter located inside the COLUMBIA GENERATING STATION Amendment 61 FINAL SAFETY ANALYSIS REPORT December 2011 LDCN-10-001 2.3-30 Met Tower building. The Met Tower building provides a semi-controlled environment near the tower to house the instrument electronics. Signal conditioning is provided in the Met Tower by two GE FANUC PLC controllers, one for the primary instrumentation and one for the backup instrumentation. The primary controller feeds data to the Supervisory System and the PDIS via the LAN. The backup controller feeds data only to the PDIS via the LAN. Information will be available to all locations for both the primary and backup instruments on the LAN. The backup system does not provide data for the barometric pressure or the rain gauge. Wind speed, wind direction, temperature, temperature difference and relative humidity signals are averaged by the controllers using a 15 minute time constant device before sending the information to the control room. In the control room are three recorders which record 245-ft and 33-ft wind speed, wind direction, delta temperature, and ambient temperature at 33-ft elevation. The system accuracies for the measured meteorological parameters are demonstrated to meet or exceed the following specifications by performance of instrument loop calibrations:

Air temperature +/-0.5°C (+/-0.9°F) Temperature difference +/-0.2°C (+/-0.36°F)

Humidity (dew point) +/-2.8°C (+/-5.0°F)

Wind speed +/-0.50 mph from 0.5 to 5 mph, +/-10% of reading above 5 mph per RG 1.97, Rev. 3. Wind direction +/-5.0° This data is processed by the Supervisory System which forms the primary communication vehicle for the meteorological system. The supervisory system located at the meteorological tower building and the control room digitizes and multiplexes the data to the control room where it is restored to analog format and sent to recorders and the PPCRS, as required, on a real-time basis. The data input to the supervisory system is 15-minute average analog values. Longer period averages will also be computed for trend analysis and report generation. These data are routed to satisfy display and processing requirements of the onsite technical support centers (TSC) and the emergency operations facility (EOF). The primary meteorological tower data is stored by the plant data acquisition system. Instrument calibrations and maintenance procedures meet the data recovery and system accuracy requirements of Regulatory Guide 1.23 except as noted above.

The Emergency Dose Projection system provides redundant data communication paths with remote access and redundant power sources as required for routine or emergency preparedness support. The near real time access to both the primary and backup meteorology systems, via the supervisory system or the LAN, thus satisfies the emergency preparedness requirements of Regulatory Guide 1.23.

These two systems are designed to meet or exceed data unavailability statements of Regulatory Guide 1.23. If offsite meteorological data is needed, data can be obtained from a network of meteorological towers located on the Hanford Site using methods described in the Emergency COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-31 Preparedness Plan. The accuracy, calibration, and reliability of all data not directly controllable by Energy Northwest is determined by the private/governmental controlling agency. 2.3.3.3 Other Meteorological Measurement Programs Considered for the Data Comparisons 2.3.3.3.1 CGS Temporary Tower A temporary 23-ft onsite tower was used during the period April 1, 1972, through August 31, 1974, to obtain data input for CGS environmental studies and to provide a comparative overlap with the initially measured permanent tower data.

The temporary tower was located in the vicinity of the permanent towers with its base at approximately 448 ft msl. Wind data from the temporary tower were obtained at the 23-ft level while temperature data were acquired at the 3-ft level. Wet bulb data from the temporary tower were established from techniques and data contained in the U.S. Department of Commerce, Weather Bureau Office Document, Relative Humidity and Dewpoint Table. As a special quality assurance program was not initiated for the temporary tower installation, it is not possible to assert that this tower's data complied with the requirements contained in Regulatory Guide 1.23. 2.3.3.3.2 Hanford Meteorological Station The Hanford Site maintains a network of meteorological towers, which can be accessed for data by telephone or electronic form. 2.3.3.4 Joint Stability - Wind Frequency Summaries Joint frequencies of wind direction and wind speed by atmospheric stability class (sigma theta by t classes), collected at the 33 ft level of the permanent tower during the period from January 1, 1984 to December 31, 1989 are presented in Table 2.3-28A. The sigma theta/t stability classification approach (see 2.3.2.1.5) has been used by Battelle to maintain consistency with the longer term HMS data to which existing data is compared and to satisfy the data requirements of the Hanford Diffusion Model (HDM) the HDM requires joint measurements of sigma theta and t for the more restrictive stable diffusion cases and utilizes the Sutton method with locally derived parameters for neutral and unstable cases (21). The HDM differs from the standard NRC diffusion models as a result of the incorporation of empirically derived diffusion coefficients based on historical experiments performed at Hanford. As a result of the extensive experimental data that were used in deriving the HDM, itis appropriate to consider this model when performing diffusion analysis at the Hanford Reservation.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-32 In 2.3.2.1, comparisons between measured CGS onsite data and simultaneously recorded and historical HMS data illustrated the following differences between sites:

a. The CGS site experienced a small air moisture enhancement during the first annual cycle of monitoring. During the second annual cycle, the CGS site experienced air of essentially the same moisture content as did the HMS site.

b. The CGS site experiences a biomodal wind direction distribution from approximately south and also northwest. At HMS, the direction distribution displays a single peak at approximately west northwest to northwest.

c. The CGS site experiences air of greater thermal stability than does HMS.

Reasons for these differences were given in 2.3.2.1.

2.3.4 SHORT TERM DIFFUSION ESTIMATES 2.3.4.1 Objective In this section brief descriptions of the sources, the receptors, and the methodologies used to calculate the air dispersion factors, /Q, for the Exclusion Area Boundary (EAB), the Low Population Zone (LPZ), and the control room are presented. 2.3.4.2 Exclusion Area Boundary The EAB is located at a distance of 1950 m (approximately 1.2 miles) from the site. The /Qs were calculated using site-specific meteorological data from 1996 to 1999, (Reference 2.3-38). The Joint Frequency Distributions (JFDs), Table 2.3-28, were used as an input to the computer code PAVAN, (Reference 2.3-25) and the /Q results are presented in Table 2.3-37. The /Q values at the EAB are calculated for each hour of data. The cumulative probability distribution of these values are determined for each of the wind direction sectors. Two distributions are calculated, Pasquill-Gifford (P-G) with meander sigmas and desert sigmas (includes meander). The distributions represent the annual probabilities that the given /Q values will be exceeded in each wind direction sector at the exclusion area distance. Table 2.3-34 incorporates the P-G meander effect and Table 2.3-33 has desert sigmas. From each of the sixteen sector distributions, the /Q value which is exceeded 0.5 percent of the total time was selected. This value was selected based on the percentage of total observations rather than the percentage of observations that the wind direction is within the appropriate sector. These 16 sector /Q values are given in Tables 2.3-33 through 2.3-34. The highest of these sixteen values is defined as the maximum sector /Q value.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-33 2.3.4.3 Low Population Zone The LPZ is located at a distance of 4827 m (approximately 3 miles) from the site. The /Qs were calculated using site specific meteorological data from 1996 to 1999, (Reference 2.3-38), the JFDs, Table 2.3-28, were used as an input to the computer code PAVAN, (Reference 2.3-25) and the /Q results are presented in Table 2.3-37. The sector /Q values at the LPZ have been estimated for various fixed time intervals of a 30-day period. These time intervals are 0 - 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, 2 - 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, 8 - 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and 1 - 30 days. The estimates for these time periods are made by interpolation on a log-log plot of the two-hour and annual average values as described by Regulatory Guide 1.145. These interpolations are carried out for the value which is exceeded 5 percent of the time, and 0.5 percent of the time. The interpolations are displayed in Tables 2.3-35 (Desert) through 2.3-36 (P-G, meander). For these interpolations the 2-hour values are assumed equivalent to the 1-hour values. These depictions and interpolation schemes are identical to those specified in Regulatory Guide 1.145. 2.3.4.4 Control Room The control room air dispersion factors /Q were calculated using the 1996 to 1999 site-specific hourly meteorological data, (Reference 2.3-37). The meteorological data and the input parameters were used as input to the computer code ARCON96, (Reference 2.3-36), and the /Q results are presented in Table 2.3-37. 2.3.4.5 Description of Sources There are 4 sources at CGS that could release radioactivity to the environment following an accident. These sources are described below: a. The roofline source is a vent (short stack) on top of the reactor building at a height of 70 m (approximately 229 ft) above the ground through which routine releases take place. Following an accident, the exhaust air from the reactor building passes through the SGT filtration system before exiting through the roofline stack. This source is treated as a ground level point source in the /Q calculations. b. The reactor building railroad bay doors are located at the ground level on the eastside wall of the reactor building. It is assumed that some leakage to the environment takes place through these doors. c. The reactor building walls from the 606 ft level to the 670 ft level (top of reactor building) are made of metal sheets and therefore they are assumed to be COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-34 a diffuse source capable of leaking radioactive materials to the atmosphere, this source is also treated as a ground level release source. d. The Turbine Building Exhaust System (TBES) is a set of four circular vents (short stacks) located on top of the radwaste building roof. Air from the turbine building is exhausted to the atmosphere through these 4 vents. 2.3.4.6 Control Room Intakes There are three intakes at CGS which draw air into the control room during normal operation as well as post accident. A description of these intakes is given below: a. Local intake point: The local intake point is a vent located on the west side of the radwaste building wall at an elevation of 527 ft (26.5 m above the ground). b. Remote intakes: there are two ground level remote intake points which are approximately 180 degrees from each other. One remote intake is located to the north-west side of the turbine building and is labeled remote-1, the other is located to the south-east side of the reactor building and is labeled remote-2. 2.3.4.7 Calculations Formulations for calculating short term /Q values have been developed for licensing of nuclear power plants and are described in Regulatory Guide 1.145, (Reference 2.3-26) "Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants." For the CGS configuration, it is assumed that accidental releases are made at ground level. This assumption provides a conservative estimate of downwind /Q values. NRC code PAVAN (Reference 2.3-25) is used to produce dispersion estimates with the desert sigma option enabled.

Based on the guidance given in Regulatory Guide 1.145 the /Q values are calculated using three separate equations. The particular equation which is used depends upon the existing meteorological conditions. The equations are: (1) )2A / yz(U1Q / 10+= (2) )yz3(U1Q / 10= (3) yzU1Q / 10=

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-35 Where /Q is relative concentration (sec/m3) is 3.14159 U10 is the wind speed at the 10 meter level (m/sec) y is the horizontal desert diffusion parameter (m) determined from downwind distance and stability category. z is the vertical desert diffusion parameter (m) determined from downwind distance and stability category. Y represents plume meander and building wake effects (m) and is a function of stability category, wind speed, and downwind distance. A is the smallest vertical plane cross-sectional area of the reactor building (m2). During neutral or stable atmospheric stability conditions, the results of all three equations are used to determine dosages. The values from Equations (1) and (2) are compared and the larger is selected. This value is compared with that computed in Equation 3 and the lower value is selected as the appropriate /Q value. During all other meteorological conditions (unstable and/or wind speeds of 6 m/sec or more), only equations (1) and (2) are considered. The appropriate /Q value is the larger of the two. Values of Y and z, the horizontal and vertical diffusion parameters are taken from Regulatory Guide 1.145 for the applicable stability category and downwind distance. For extremely stable condition (Category G), the following equations are applied: Y(G) = 2/3 Y(F) z(G) = 3/5 z(F) 2.3.5 LONG-TERM (ROUTINE) DIFFUSION ESTIMATES

2.3.5.1 Objectives The joint wind direction and wind speed by atmospheric stability class data presented in Subsection 2.3.3 was used to assess annual average normalized concentrations, X/Q, for 16 radial sectors extending from the site boundary to a distance of 50 miles from the source. Tables 2.3-38 provides X/Q and D/Q concentrations for a mix mode release assuming desert COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-36 sigmas no decay, no plume depletion, recirculation, and a building wake (building height - 70.4 m). D/Q is normalized deposition.

2.3.5.2 Calculations The calculational techniques used are consistent with the guidance provided in Regulatory Guide 1.111 "Methods for Estimating Atmospheric Transport and Dispersions of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors". The joint frequency data presented in Subsection 2.3.3 were used in conjunction with the following equation to obtain X/Q values at appropriate downwind distance in each of the 16 sectors. ()()()(,).exp()./xQfhxRxxuxxDijijezjfxizj=+2032205222212 Where: (,)xQ = average effluent concentration in Ci/m3 normalized by source release rate (Ci/sec) at distance x and direction k.

x = downwind distance from release point.

ui = midpoint value of ith wind speed class.

he = effective plume height. zj(x) = vertical standard desert deviation of effluent spread at distance x for the jth stability class.

Rfx = factor to account for air recirculation and stagnation.

fijk = joint probability of the ith wind speed class, jth stability, class, and kth wind direction. = 3.1416 D = maximum building height of adjacent buildings (D = 70.4 m)

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-37 The building wake correction Equation 1 must not reduce the X/Q estimate by more than a factor of 3 or ()2220512312xjxDzjx()./()/+ Equation 1 assumes a long-term continuous release whose effluent is distributed evenly across a 22.5° sector. The release was assumed to be ground level (i.e., he = 0 in Equation 1). Computer code X0QD0Q, with the Desert sigma option enabled described in NUREG-0324, was used to make two sets of calculations. The nearest residences where maximum individual doses with single sector contributions occur at distances of 4.0 miles ENE (Ringold) and 4.2 miles ESE (Taylor Flats) of CGS. The annual average /Q values for these locations are calculated in Table 2.3-38c, 38f and 39c, 39f. The Columbia bluffs rise to an elevation of 878 ft just south of Taylor Flat. If it is considered that the low level sigma Z is less than 100 m out to 6 km for the P-G stability classes D-G, which are prevalent most of the winters and that low-level winds deflect either north or south near the bluffs (Reference 2.3-2), it is estimated that the total doses for these locations may be once again as large due to contributions of favorably oriented wind sectors. The total dose in the channeling area of the Columbia River should include contributions from four other sectors with deflected winds and other channeling effects. The individual doses in that location could be twice as large as for the single sector, constant wind computations. The drift from the cooling towers should remove some of the effluent and deposit it on the site with the salts and counteract the bluff effect. The mechanical draft cooling towers should entrain part of the effluent, lift it with the plume and thus also make the /Q values over-predictive. Reasons for these differences were given in Subsection 2.3.2.1.

The results reported by Start and Wendell ("Regional Effluent Dispersion Calculation Considering spatial and Temporal Meteorological Variation," Preprint volume, Symposium on Atmospheric Diffusion and Air Pollution of the American Meteorological Society, September 9-13, 1974) indicate an average value at these distances of about 0.65 and a minimum single point value of about 1.75. If these factors are multiplied by the fraction of plume remaining at the distances in question, about 0.75, to account for the conservatism of the nondepleting model used to arrive at the dose estimates provided in 5.2 of the CGS Environmental Report, it is found that the most critical dose of 9.2 mrem to a child's thyroid (at Taylor Flat) is still within the 10 CFR Part 50 Appendix I design objective limit of 15 mrem. For example, 1.75 x 0.75 x 9.2 = 12.1 mrem. This value would still be conservative because the above recirculation factors do not account for the existence of a bluff line immediately downwind of Taylor Flat which will under the more stable conditions turn the plume before it reaches Taylor Flat. This effect would further reduce the effective recirculation factor.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-38 At the nearest point of the nearest population center, about 9 miles, the average recirculation factor value from Start and Wendell, 1974, appears to be about 0.3 with the maximum single point value about 0.8. In addition to this effect, the effect of topographic channeling has been evaluated by conservatively hypothesizing that under stable conditions that winds blowing anywhere from the east to west (through north) sector might end up in the four sectors containing the majority of the population, SE through WSW (Pasco through Benton City). Including the effects due to channeling results in an estimated maximum factor of approximately 1.6. Applying the factors for recirculation and fraction of plume remaining after deposition results in a maximum effective factor of (1.6 x 0.8 x 0.67 = 0.86) less than one.

It therefore appears reasonable to conclude that the methodology employed to estimate doses is sufficiently conservative for the subject site to ensure that the doses to individuals and the general population have not been substantially underestimated due to the inherent assumptions.

2.

3.6 REFERENCES

2.3-1 Baker, D. A., Diffusion Climatology on the 100-N Area, Hanford Washington, Douglas United Nuclear Company, DUN-7841, Richland, Washington, January 1972.

2.3-2 Stone, W. A., et al. Climatography of the Hanford Area, Battelle Pacific Northwest Laboratories, BNWL-1605, Richland, Washington, June 1972.

2.3-3 Stone, W. A. Meteorological Instrumentation of the Hanford Area, General Electric, Hanford Atomic Products Operation, HW-62455, Richland, Washington, March 1964.

2.3-4 Phillips, E., Tri-City Area, Kennewick-Pasco-Richland, Washington Narrative Climatological Summary, Climatography of the United States No. 20-45, U.S. Department of Commerce and Economic Development.

2.3-5 Federal Meteorological Handbook No. 1, Surface Observations, U.S. Government Printing Office, January 1970. 2.3-6 Fujita, T., Estimate of Maximum Wind Speed of Tornadoes in Three Northwestern States, SMRP Research Paper No. 92, University of Chicago, December 1970. 2.3-7 Jaech, J. L., Statistical Analysis of Tornado Data for the Three Northwestern States, Jersey Nuclear Company, Richland, Washington, December 1970.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-39 2.3-8 Daubek, H. G., Tornado History and a Discussion of the Tornado Warning System, Battelle Memorial Institute, Pacific Northwest Laboratories Report to Jersey Nuclear Company, Richland, Washington, December 1970. 2.3-9 Thom, H. C. S., "New Distribution of Extreme Winds in the United States," Journal for the Structural Division, ASCE, ST-7, July 1968, pp 1787-1801.

2.3-10 ASCE Task Committee Report, Wind Forces on Structures, Paper No. 3269, Vol. 126, 1961.

2.3-11 Larson, L. B., Air Pollution Potential Over Southeastern Washington, U.S. Weather Bureau, Walla Walla, Washington, May 1970 (unpublished Presentation).

2.3-12 Holzworth, G. C., "Estimates of Mean Maximum Depths in the Contiguous United States," Monthly Weather Review, Vol. 92, pp 235-242, May 1964.

2.3-13 Hosler, C. R., "Low-Level Inversion Frequency in the Contiguous United States," Monthly Weather Review, Vol. 89, pp 319-339, September 1961.

2.3-14 Huschke, R. E., ed., Glossary of Terms Frequently Used in Air Pollution, American Meteorological Society, Boston, Massachusetts, January 1968.

2.3-15 Jenne, D. E., Frequency Analysis of Some Climatological Extremes at Hanford, General Electric, Hanford Atomic Products Operation, Richland, Washington, April 1963.

2.3-16 Hilst, G. R., and Nickola, P. W., "On Wind Erosion of Small Particles," Bulletin of the American Meteorological Society, Vol. 40, pp 73-77, February 1959.

2.3-17 Sehmel, G. A., and Lloyd, F. D., Airborne Dust Concentrations, Pacific Northwest Laboratories Annual Report for 1971 to the USAEC Division of Biology and Medicine, Vol. II, Part 1, Atmospheric Sciences, Battelle Pacific Northwest Laboratories, BNWL-1651, Richland, Washington, December 1972.

2.3-18 Bramson, P. E., and Corley, J. P. Environmental Surveillance at Hanford for CY-1971, Battelle Northwest Laboratories, BNWL-1683, Richland, Washington, August 1972.

2.3-19 ANSI A58, 1-1972, "Building Code Requirements for Minimum Design Loads in Buildings and Other Structures," American National Standards Institute, 1972.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 2.3-40 2.3-20 Simpson, C. L., Computer Printouts of Meteorological Data from the HMS and Hanford No. 2 Sites, March 1-August 31, 1972, BNWL, September 1972.

2.3-21 PSAR WPPSS Nuclear Project No. 1, August 1974 (Docket No. 50-460).

2.3-22 Droppo, J. G. et al., Atmospheric Effects of Circular Mechanical Draft Cooling Towers at Washington Public Power Supply System Nuclear Power Plant Number Two, Final Report to Burns and Roe, Inc., November 1976.

2.3-23 Quality Assurance Program for the Acquisition, Processing, and Analysis of Meteorological Data for Washington Public Power Supply System Nuclear Project No. 2, Battelle Pacific Northwest Laboratories, Richland, Washington, April 1974.

2.3-24 Regulatory Guide 1.70, Rev. 3, Standard Format and Content of Safety Analysis Reports For Nuclear Power Plants, November 1978.

2.3-25 T. J. Bander, "PAVAN: An Atmospheric Dispersion Program for Evaluating Design Basis Accidental Releases of Radioactive Materials from Nuclear Power Stations," NUREG/CR-2858 (November 1982).

2.3-26 U.S. Nuclear Regulatory Commission, 1979: Regulatory Guide 1.145, "Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants," USNRC Office of Standards Development, Wash., D.C.

2.3-27 Gifford, F. A., 1975: Atmospheric Dispersion Models for Environmental Pollution Applications. Lectures on Air Pollution and Environmental Impact Analyses, American Meteorological Society, pp. 35-38.

2.3-28 PSAR WPPSS Nuclear Project No. 2, February 1973.

2.3-29 Fix, J. J., Environmental Surveillance at Hanford for CY-1974, Battelle Northwest Laboratories, BNWL-1910, Richland, Washington, April 1975.

2.3-30 Orgill, M. M., G. A. Sehmel, and T. J. Bander, 1974: "Regional Wind Resuspension of Dust," Pacific Northwest Laboratory Annual Report for 1973, to the USAEC Division of Biomedical and Environmental Research, Part 3, Atmospheric Sciences, BNWL-1850, pp. 214-219.

2.3-31 Hagen, L. J. and N. P. Woodruff, 1973: "Air Pollution from Duststorms in the Great Plains," Atmos. Environ., 7, pp. 323-332.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-41 2.3-32 Sehmel, G. A., 1976: "The Influence of Soil Insertion on Atmospheric Particle Size Distributions," Pacific Northwest Laboratory Annual Report to ERDA Division of Biomedical and Environmental Research, Part 3, Atmospheric Sciences, BNWL-200, pp.99-101.

2.3-33 A. Brandstetter of BNL to J. J. Verderber of Burns and Roe Inc., entitled "Hanford Duststorm Climatology Environmental Studies for CGS," and dated December 2, 1977.

2.3-34 U.S. Atomic Energy Commission, 1972: Regulatory Guide 1.23, Onsite Meteorological Programs.

2.3-35 Briggs, G. A., 1973: "Diffusion Estimation for Small Emissions in Environmental Research Laboratory," Air Resources Atmos. Turbc. and Diffusion Lab. 1973 Annual Report, ATDL-106, USDOC-NOAA.

2.3-36 NUREG-6331, "Atmospheric Relative Concentrations in Building Wakes," Revision 1, May 1997, ARCON96 RSICC Computer Code Collection November CCC-664. 2.3-37 Calculation NE-02-03-14, "Control Room /Q Using ARCON96 with 1996-1999 Meteorological Data." 2.3-38 Calculation NE-02-03-16, "Calculation of the EAB and LPZ /Q Using PAVAN with 1996-1999 Meteorological Data."

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-43Table 2.3-1 Averages and Extremes of Climatic Elements at Hanford (Based on all Available Records to and Including the Year 1980) PAGE 1 OF 2 TEMPERATURE (F) DEGREE DAYS (BASE 65F) PRECIPITATION (INCHES) 1912-1980 AVERAGES 1912-1980 EXTREMES DEGREE DAYS (BASE 65F) 1912-1980 TOTALS DAILY MAXIMUM DAILY MINIMUM HEATING 1945-1980 TOTALS COOLING 1960-1980 TOTALS SNOW, ICE PELLETS (SLEET) DAILY MAXIMUM DAILY MINIMUM MONTHLY HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR RECORD HIGHEST YEAR RECORD LOWEST YEAR RECORD HIGHEST YEAR RECORD LOWEST YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MINIMUM MONTHLY YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MINIMUM MONTHLY YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MINIMUM MONTHLY YEAR MAX. IN 24 HOURS YEAR MEAN MONTHLY MAXIMUM MONTHLY YEAR MAX. IN 24 HOURS YEAR MAXIMUM DEPTH YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Year 36.6 45.4 56.5 66.2 75.5 83.2 91.8 89.3 79.6 65.4 48.4 39.4 64.8 21.9 27.3 33.7 40.0 47.8 55.3 61.0 59.2 50.8 40.6 31.3 26.0

41.2 29.3 36.3 45.1 53.1 61.7 69.3 76.4 74.3 65.2 53.0 39.8 32.7

53.0 42.5 44.5 49.8 59.6 68.8 75.4 81.8 81.5 71.7 59.0 46.0 38.5

81.8 1953 1958 1926 1934 1947 1922 1960 1967 1967 1952 1954 1957 July 1960 12.1 21.4 39.4 47.5 56.6 63.0 72.4 69.8 58.8 48.8 31.3 18.5

12.1 1950 1929 1955 1955 1933 1953 1963 1964 1926 1930 1955 1919 Jan 1950 72 71 83 95 103 110 115 113 102 90 75 69 115 1971 1924 1960 1934 1936+

1912 1939 1961 1976+

1933 1975 1980 July 1939 -2

-3 24 41 49 55 59 63 52 31 14 -3 -3 1950 1950 1960 1945 1918 1966 1966 1920 1934 1935 1955 1919 Feb 1950+ 53 55 54 60 70 81 82 81 72 60 52 56 82 1971 1932 1942 1956 1956 1924 1925 1961+

1955 1945+

1959+

1975 July 1925 -23

-23 6 12 23 33 39 40 25 6 27 -27 1934 1950 1955 1935 1954 1933 1979 1918 1926 1935 1955 1919 Dec 1919 1104 781 638 381 156 35 4 6 70 376 758 990 5299 1640 1147794 522 25890 22 32179 4791008 122416401950 1956 1955 1955 1977 1953 1955 1960 1972 1946 1955 1964 Jan 1950 694 576 476 253 36 3 0

0 10 200 567 822 0 1953 1958 1947 1977 1947 1938 1975+1979+1979+1952 1954 1957 Aug 1979+0 0

0 2 43 183 384 323 102 2 0

0 1039 0 0

0 24 94 310 518 508 216 10 0 0 518 ------

---

---

1977 1971 1969 1960 1967 1967 1971

---

---

July 1960 0 0

0 0

3 57 232 171 27 0 0

0 0 ------

---

---

1978+

1962 1980 1963 1964 1970 1977+

---

---

Apr 1978+ 0.92 0.60 0.37 0.39 0.48 0.54 0.15 0.24 0.31 0.56 0.85 0.89

6.302.47 3.08 1.86 1.22 2.03 2.92 0.81 1.36 1.34 2.72 3.05 2.53 3.081970 1940 1957 1969 1972 1950 1966 1977 1947 1957 1926 1931 Feb 1940 0.08 T 0 0

0 0

0 0 T 0 T 0.11 0 1977 1967 1942+

1933+

1931 1919 1939+

1955+

1976+

1917+

1976+

1976+

Aug 1955+ 1.08 1.24 0.59 0.58 1.39 1.50 1.25 0.89 0.82 1.91 0.78 1.00 1.91 1948 1916 1949 1980 1972 1934 1942 1977 1947 1957 1966 1958 Oct 1957 5.3 2.3 0.3 T T 0 0

0 0 T 1.4 3.9 13.223.4 26.04.2 T T 0 0

0 0 1.5 12.7 19.1 26.01950 1916 1951 1968+

1960

---

---

---

---

1973 1955 1964 Feb 1916 7.1 18.02.2 T T 0 0

0 0 1.5 8.3 5.4 18.01954 1916 1957 1968+

1960

---

---

---

---

1973 1978 1965 Feb 1916 12.0 24.52.3 0 0

0 0

0 0 1.5 9.1 12.1 24.51969 1916 1957

---

---

---

---

---

---

1973 1978 1964 Feb 1916 WIND (mph) RELATIVE HUMIDITY (%) SKY COVER (SCALE 0-10) SOLAR RADIATION (LANGLEYS)* 1945-1980 AVERAGES PEAK GUSTS 1946-1980 AVERAGES 1946-1980 EXTREMES 1946-1980 AVERAGES (SUNRISE TO SUNSET) 1953-1980 AVERAGES DAILY TOTALS 1953-1980 EXTREME DAILY TOTALS PREVAILING DIRECTION MEAN MONTHLY SPEEDS HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR SPEED DIRECTION YEAR MEAN HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR HIGHEST YEAR LOWEST YEAR MONTHLY HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR MONTHLY HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR HIGHEST MONTHLY YEAR LOWEST MONTHLY YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Year NW NW WNW WNW WNW WNW WNW WNW WNW WNW NW NW

WNW 6.4 7.1 8.5 9.0 8.9 9.2 8.7 8.0 7.5 6.6 6.1 6.1

7.7 10.3 10.8 10.7 11.1 10.5 10.7 9.6 9.1 9.2 9.1 8.2 8.3 11.1 1972 1976 1977+ 1972+ 1965+ 1949 1963 1946 1961 1946 1977 1968 Apr 1972+ 3.1 4.6 5.9 7.4 5.8 7.7 6.8 6.0 5.4 4.4 2.9 3.9

2.9 1955 1963 1958 1958 1957 1950+ 1955 1956 1957 1952 1956 1963+ Nov 1956 80 65 70 73 71 72 69 66 65 63 64 71 80 SW SW SW SSW SSW SW WSW SW SSW SSW SSW SW

SW 1972 1971 1956 1972 1948 1957 1979 1961 1953 1950 1949 1955 Jan 1972 76.4 70.7 55.9 46.9 43.0 39.7 32.2 35.6 41.6 56.8 73.6 80.0 54.3 88.8 86.9 65.9 64.5 61.9 53.5 40.5 47.8 55.5 74.2 88.7 90.5 90.5 1960 1963 1950 1963 1948 1950 1955 1976 1977 1962 1979 1950 Dec 1950 60.0 54.0 44.0 36.9 31.2 30.0 21.9 24.5 33.2 42.5 62.8 69.0 21.9 1963 1967 1965 1966 1966 1949 1959 1967 1974 1952 1976 1968 July 1959 100 100 100 100 100 100 99 100 100 100 100 100 100 1980+ 1980+ 1979+ 1978+ 1978+ 1977+ 1972 1972+ 1978+ 1980+ 1980+ 1980+ Dec 1980+ 13 14 12 9 7 10 6 7 10 10 16 26 6 1963 1962 1965+ 1954 1953 1964+ 1951 1951 1962+ 1952+ 1976+ 1972 July 1951 7.9 7.6 6.8 6.4 5.9 5.3 2.9 3.4 4.1 5.8 7.7 8.1 6.09.2 9.3 8.5 8.1 7.7 7.0 4.7 5.9 6.7 8.0 9.1 9.2 9.3 1978 1980 1978 1963 1977+

1950 1976 1968 1978 1975 1972 1962 Feb 1980 4.3 5.9 4.9 3.7 4.5 2.8 0.9 0.6 1.4 3.9 6.2 6.4 0.6 1949 1964 1965 1951 1945 1961 1953 1955 1975 1952 1957 1978 Aug 1955 116 194 335 469 569 627 650 548 415 262 130 89 367 136 238 388 535 634 698 714 613 463 303 180 116 714 1973 1970 1965 1973 1970 1960 1973 1955 1975 1976 1957 1970 July 1973 78 128 293 374 472 537 588 475 326 216 97 57 57 1978 1980 1978 1963 1980 1980 1955 1968 1977 1975 1979+ 1980+ Dec 1980+277 422 542 704 838 821 808 721 591 434 295 196 838 1969 1958 1968 1972 1977 1971 1974 1957 1970 1973 1971 1972 May 1977 16 21 44 75 67 112 118 107 61 33 14 9 9 1976+

1976 1979 1974 1962 1965 1972 1959 1957 1974 1969 1973 Dec 1973 EXTREME AVERAGES OR TOTALS AND YEAR OR SEASON OF OCCURRENCE 1912-1980 TEMPERATURE AVERAGES (F) HIGHEST ANNUAL 56.2 (1958+)

LOWEST ANNUAL 50.2 (1929)

HIGHEST WINTER (D-J-F) 41.1 (1933-34)

LOWEST WINTER 24.2 (1948-49)

HIGHEST SPRING (M-A-M) 58.2 (1947)

LOWEST SPRING 48.0 (1955)

HIGHEST SUMMER (J-J-A) 78.2 (1958)

LOWEST SUMMER 70.2 (1980)

HIGHEST FALL (S-O-N) 56.6 (1963) LOWEST FALL 49.5 (1978) 1912-1980 PRECIPITATION TOTALS (IN.)

GREATEST ANNUAL 11.45 (1950)

LEAST ANNUAL 2.99 (1976)

SNOW, ICE PELLETS (SLEET)

GREATEST SEASONAL 43.6 (1915-16)

LEAST SEASONAL 0.3 (1957-58)

1945-1980 WIND SPEED AVERAGE (MPH)

HIGHEST ANNUAL 8.3 (1968+)

LOWEST ANNUAL 6.3 (1957)

1945-1980 RELATIVE HUMIDITY AVERAGE (%)

HIGHEST ANNUAL 58.9 (1978)

LOWEST ANNUAL 49.4 (1967)

1945-1980 SKY COVER AVERAGES (SUNRISE TO SUNSET, SCALE 0-10)

HIGHEST ANNUAL 6.6 (1978+)

LEAST ANNUAL 5.1 (1949)

1953-1980 SOLAR RADIATION AVERAGE DAILY TOTAL (LANGLEYS)

HIGHEST ANNUAL 390 (1973) LOWEST ANNUAL 324 (1980)

• CALORIES/cm2 +ALSO ON EARLIER YEARS COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-44NUMBER OF DAYS CLEAR (0-3 TENTHS SKY COVER, SR TO SS)

GREATEST ANNUAL (1954-80) 121 1960 LEAST ANNUAL (1954-80) 80 1977

CLOUDY (9-10 TENTHS SKY COVER, SR TO SS)

GREATEST ANNUAL (1954-80) 193 1978 LEAST ANNUAL (1954-80) 85 1966

THUNDERSTORMS GREATEST ANNUAL (1945-80) 23 1948 LEAST ANNUAL (1945-80) 3 1949

HEAVY FOG (VIS. 1/4 MILE OR LESS)

GREATEST SEASONAL (1945-80) 42 1950-51 LEAST SEASONAL (1945-80) 9 1948-49

PRECIPITATION 0.10 INCH OR MORE GREATEST ANNUAL (1946-80) 39 1950 LEAST ANNUAL (1946-80) 10 1965

SNOW 1.0 INCH OR MORE GREATEST SEASONAL (1946-80) 15 1955-56 LEAST SEASONAL (1946-80) 0 1976-77

3 IN. OR MORE SNOW ON GROUND GREASTEST SEASONAL (1946-80) 40 1978-79+

LEAST SEASONAL (1946-80) 0 1976-77

PEAK GUST 40 MPH OR GREATER GREATEST ANNUAL (1945-80) 41 1961 LEAST ANNUAL (1945-80) 10 1978

MAX. TEMPERATURE 90 OR ABOVE GREATEST ANNUAL (1912-80) 85 1940+

LEAST ANNUAL (1912-80) 29 1980

MAX. TEMPERATURE 100 OR ABOVE GREATEST ANNUAL (1912-80) 32 1942 LEAST ANNUAL (1912-80) 1 1954

MAX. TEMPERATURE 32 OR BELOW GREATEST SEASONAL (1912-80) 53 1955-56 LEAST SEASONAL (1912-80) 1 1937-38

MIN. TEMPERATURE 32 OR BELOW GREATEST SEASONAL (1912-80) 141 1916-17 LEAST SEASONAL (1912-80) 75 1957-58

MIN. TEMPERATURE 0 OR BELOW GREATEST SEASONAL (1912-80) 18 1949-50 LEAST SEASONAL (1912-80)01976-77Table 2.3-1 Averages and Extremes of Climatic Elements at Hanford (Based on all Available Records to and Including the Year 1980) (Continued) PAGE 2 OF 2 NUMBER OF DAYS (1954-1980) NUMBER OF DAYS (1945-1980)

• CLEAR PTLY CLDY CLOUDY THUNDERSTORMS HEAVY FOG (VIS. 1/4 MI. OR LESS) PRECIPITATION 0.10 INCH OR MORE SNOW 1.0 INCH OR MORE MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MONTHLY MEAN GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Year 3 4

6 6

8 10 19 18 15 10 4 3 106 7 9 12 12 14 21 26 30 27 14 10 9 30 1963 1968+

1979+

1962 1973 1961 1960 1955 1975 1980+

1957 1978 Aug 1955 0 0

1 1

1 5 13 9 6

1 1

1 0 1955+

1980+

1978+

1963 1977 1972+

1976+

1978 1978 1975 1973+

1980+

Feb 1980+ 5 5

8 9 11 10 7 7

7 7

5 5 86 22 19 17 15 12 10 5 6

8 14 21 23 172 28 26 23 21 19 15 12 13 16 22 25 28 28 1978 1980+

1977 1979+

1977+

1980+

1976 1968 1977 1973 1973+

1962 Jan 1978+ 17 12 9 6

6 5

0 0

1 9 15 17 0 1963 1964 1979+

1956 1958 1979+

1967 1969+

1975 1970 1961 1978 Aug 1969+ 0

1 2

2 2

2 1

0

1. 10 0 1

1 3

7 8

7 8

4 2

0 1 8 ------

1972+

1969+

1979+

1956 1972+

1975 1953 1959 1976

---

1971 June 1972+ 0 0

0 0

0 0

0 0

0 0

0 0 0 ------

1980+

1980+

1977+

1977+

1963+

1973+

1974+

1976+

1980+

---

1980+

---

6 3

1

0

1 6

8 25 15 11 5 1

1 1

0 1

1 7 13 17 17 1976 1963 1951 1975+

1958 1971

---

1959 1977 1980 1965 1950 Dec 1950 0 0

0 0

0 0

0 0

0 0

0 2 0 1949 1977 1980+

1980+

1980+

1980+

---

1980+

1980+

1978+

1960 1968+ ------ 3 2 2

1 2

2 1

1 1

2 3

3 23 8 5

8 5

4 8

3 4

5 8 10 9 10 1970 1980+

1957 1948 1980+

1950 1974+

1976+

1977+

1950 1973 1964 Nov 1973 0 0

0 0

0 0

0 0

0 0

0 0 0 1977+

1979+

1980+

1977+

1979+

1979+

1980+

1980+

1978+

1978+

1976+

1976+

Aug 1980+ 2 1

0 0

0 0

0 0

1 1

2 6 10 4 2

0 0

0 0

0 0

1 6

6 10 1950 1975+

1957+

---

---

---

---

---

---

1973 1955 1964 Jan 1950 0 0

0 0

0 0

0 0

0 0

0 0 0 1977+

1979+

1980+

---

---

---

---

---

---

1980+

1980+

1976+ ------ NUMBER OF DAYS (1945-1980) NUMBER OF DAYS (1912 - 1980) 3" OR MORE SNOW ON GND. PEAK GUST 40 MPH OR GREATER MAX. TEMP 90 OR ABOVE MAX. TEMP 100 OR ABOVE MAX. TEMP. 32 OR BELOW MIN. TEMP. 32 OR BELOW MIN. TEMP 0 OR BELOW MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLY YEAR MEAN MONTHLY GREATEST MONTHLY YEAR LEAST MONTHLYY YEAR Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Year 5 3 0

0 0

0 0

0 0

0 1

2 11 23 16 0 0

0 0

0 0

0 0 12 14 23 1969 1950

---

---

---

---

---

---

---

---

1978 1955 Jan 1969 0 0 0

0 0

0 0

0 0

0 0

0 0 1977+

1978+

---

---

---

---

---

---

---

---

1980+

1980+

---

3 2 3

3 2

2 1

1 1

2 2

3 25 11 10 9 7

6 6

4 5

4 8

5 8 11 1972 1976 1956 1972 1971+

1973 1979+

1951 1946 1967 1973+

1957+

Jan 1972 0 0 0

0 0

0 0

0 0

0 0

0 0 1979+

1978+

1978 1979+

1977 1980+

1977+

1980+

1980+

1979+

1979+

1969+

---

0 0 0

3 9 20 18 5

0 0 55 0 0

0 4 11 20 29 29 16 1 0

0 29 ------

---

---

1926 1924 1940+

1941 1915 1938 1933

---

---

July 1941 0 0 0

0 0

0 8

7 0

0 0

0 0 ------

---

---

1980+

1980+

1980+

1963 1948 1977+

1980+

---

---

---

0 0 0

0

2 7

4

0 0

0 13 0 0

0 0

1 9 16 16 2 0

0 0 16 ------

---

---

---

1966+

1970 1971+

1942 1955+

---

---

---

July 1971+ 0 0 0

0 0

0 0

0 0

0 0

0 0 ------

---

---

---

1980+

1980+

1963+

1980+

1980+

---

---

---

---

11 3 #

0 0

0 0

0 0

2 8 24 30 15 2 0

0 0

0 0

0 2 15 19 30 1979 1956 1960

---

---

---

---

---

---

1935 1955 1914 Jan 1979 0 0 0

0 0

0 0

0 0

0 0

0 0 1967+

1976+

1980+

---

---

---

---

---

---

1980+

1976+

1974+

---

27 21 15 5

0 0

0

5 17 25 115 31 28 25 15 3 0

0 0

4 12 30 31 31 1980+

1944+

1944+

1935 1938

---

---

---

1933+

1916 1936 1978+

Jan 1980+ 9 5 6

0 0

0 0

0 0

0 4 14 0 1953 1958 1968+

1974+

1980+

---

---

---

1980+

1962+

1949 1933

---

2 1 0

0 0

0 0

0 0

0

1 4 14 9 0

0 0

0 0

0 0

0 1 14 14 1950 1929

---

---

---

---

---

---

---

---

1955+

1919 Jan 1950+ 0 0 0

0 0

0 0

0 0

0 0

0 0 1977+

1980+

---

---

---

---

---

---

---

---

1980+

1980+

---

REFERENCE NOTES

• PRECIPITATION OBSERVATIONS NOT BEGUN UNTIL 1946

1. LESS THAN 1/2

+ ALSO ON EARLIER YEARS LOCATION AND HISTORY PRESENT LOCATION 25 MILES NW OF RICHLAND, WASHINGTON LATITUDE 4634'N; LONGITUDE 11936'W, ELEVATION 733 FEET OBSERVATIONS FROM 1912 TO 1944 WERE BY UNITED STATES WEATHER BUREAU COOPERATIVE OBSERVERS AT A SITE ABOUT 10 MILES ENE OF PRESENT LOCATION. SINCE 1944, OBSERVATIONS HAVE BEEN MAINTAINED ON A 24 HOUR-A-DAY BASIS BY THREE DIFFERENT DOE CONTRACTORS.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-45Table 2.3-2 Average Return Period (R) and Existing Record (ER) for Various Precipitation Amounts and Intensity During Specified Time Periods at Hanford (Based on Extreme Value Analysis of 1947-1969 Records) Amount (Inches) Intensity (Inches per Hour) Time Period Time Period R (YEARS) 20 MIN 60 MIN 2 HRS 3 HRS 6 HRS 12 HRS 24 HRS 20 MIN 60 MIN 2 HRS 3 HRS 6 HRS 12 HRS 24 HRS2 5 10 25 50 100 250 500 1000 0.16 0.24 0.37 0.47 0.53 0.60 0.68 0.73 0.80 0.26 0.40 0.50 0.62 0.72 0.81 0.93 1.02 1.11 0.30 0.48 0.59 0.74 0.85 0.96 1.11 1.22 1.33 0.36 0.55 0.67 0.83 0.96 1.07 1.22 1.33 1.45 0.48 0.77 0.96 1.21 1.40 1.59 1.82 2.00 2.20 0.62 0.95 1.17 1.45 1.66 1.87 2.13 2.34 2.55 0.72 1.06 1.28 1.56 1.77 1.99 2.26 2.47 2.68 0.49 0.72 1.1 1.4 1.6 1.8 2.0 2.2 2.4 0.26 0.40 0.50 0.62 0.72 0.81 0.93 1.02 1.11 0.15 0.24 0.30 0.37 0.42 0.48 0.55 0.61 0.67 0.12 0.18 0.22 0.28 0.32 0.36 0.41 0.44 0.48 0.08 0.13 0.16 0.20 0.23 0.27 0.30 0.33 0.37 0.052 0.079 0.098 0.121 0.138 0.156 0.177 0.195 0.212 0.030 0.044 0.053 0.065 0.074 0.083 0.094 0.103 0.112

• No records have been kept for time periods of less than 60 minutes. However, the rain gage chart for 6-12-69 shows that 0.55 inch occurred during a 20-minute period from 1835 to 1855 PST. An additional 0.01 inch occurred between 1855 and 1910 to account for the record 60-minute amount of 0.59 inch.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-46Table 2.3-3 Miscellaneous Snowfall Statistics (1946 Through 1970) Oct Nov Dec Jan Feb Mar Season Average number of days with depth at 0400 PST 1" or more 3" or more 6" or more 12" or more 0 0

0 0 1 1

0 0 5 2

1

1. 10 5 3

1. 5 3

1 0 #

0 0

0 21 11 5

1. Record greatest number of days with depth at 0400 PST 1" or more 3" or more 6" or more 12" or more 0 0 0 0 (1955) 11 (1955) 10 0 0 (1964+) 17 (1955) 14 (1964) 12 (1964) 4 (1969) 31 (1969) 23 (1965) 23 (1969) 1 (1950) 17 (1950) 16 (1969+) 8 0 (1951) 3 0 0

0 (1955-56) 54 (1949-50) 38 (1949-50) 23 (1964-65) 4 Record greatest depth (1957) 0.3 (1946) 5.1 (1964) 12.1 (1969) 12.0 (1969) 10.0 (1957) 2.3 (Dec 1964) 12.1 Greatest in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (1957) 0.3 (1955) 4.8 (1965) 5.4 (1954) 7.1 (1959) 5.2 (1957+) 2.2 (Jan. 1954) 7.1 Average % of water equivalent of all precipitation 2 14 46 48 29 14 26 ( ) Denotes year of occurrence

+ Denotes also in earlier years

1. Denotes less than 1/2 day COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-47 Table 2.3-4 Tornado History Within 100 Miles of CGS Date Location June 26, 1916 Walla Walla, Washington April 15, 1925 Condon, Oregon

September 2, 1936 Walla Walla, Washington

May 20, 1948 Yakima, Washington

May 29, 1948 Yakima, Washington

June 11, 1948 Ephrata, Washington

June 16, 1948 Hanford Reservation

May 9, 1956 Kennewick, Washington

April 12, 1957 Ione, Oregon

April 30, 1957 Yakima, Washington

May 6, 1957 Harrington, Washington

April 24, 1958 Walla Walla, Washington June 26, 1958 Wallula Junction, Washington March 14, 1966 Little Goose Dam, Washington Note: No major damage or loss of life was associated with any of the tornadoes.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-48 Table 2.3-5 Monthly and Annual Prevailing Directions, Average Speeds, and Peak Gusts: 1945-1970 at HMS (50 ft level) Peak Gust Month Prev Den Avg Speed HighestAvg Year LowestAvg Year Speed Den Year Jan NW 6.4 9.6* 1953 3.1 1955 65** S 1967 Feb NW 7.0 9.4 1961 4.6 1963 63 SW 1965 Mar WNW 8.4 10.7 1964 5.9 1958 70 SW 1956 Apr WNW 9.0 11.1 1959 7.4 1958 60 WSW 1969 May WNW 8.8 10.5 1965+ 5.8 1957 71 SSW 1943 June WNW 9.2 10.7 1949 7.7 1950+ 72 SW 1957 July WNW 8.6 9.6 1963 6.8 1955 55 WSW 1963 Aug WNW 8.0 9.1 1946 6.0 1956 66 SW 1961 Sept WNW 7.5 9.2 1961 5.4 1957 65 SSW 1953 Oct WNW 6.7 9.1 1946 4.4 1952 63 SSW 1950 Nov NW 6.2 7.9 1945 2.9 1956 64 SSW 1949 Dec NW 6.0 8.3 1968 3.9 1963+ 71 SW 1955 Year WNW 7.6 8.3 1968+ 6.3 1957 72** SW June 1957

• The average speed for January, 1972, was 10.3 mph

• • On January 11, 1972, a new all-time record peak gust of 80 mph was established COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-49Table 2.3-6 Speed and Direction of Daily Peak Gusts* Speed Class (mph) Extreme High and Date of Occurrence ** Direction Under 10 10-19 20-2930-39 40-4950-59 60-69 70 orover Total mph Date NNE 0.2 0.8 1.3 0.2 0.1 0 0 0 2.6 47 Feb. 5, 1948 NE 0.3 1.0 1.0 0.2 0 0 0 0 2.5 38 July 10, 1951 ENE 0.2 0.6 0.3 0.1 0 0 0 0 1.2 37 May 27, 1947 E 0.2 0.7 0.2 0.1 # 0 0 0 1.2 44 June 11, 1950 ESE 0.1 0.4 0.1 0 0 0 0 0 0.6 26 June 2, 1958 SE 0.7 2.0 0.4 # # # 0 0 3.1 53 Aug. 29, 1947 SSE 0.7 1.8 0.5 0.1 0.1 # 0 0 3.2 52 Dec. 4, 1952 S 0.3 0.8 1.0 0.7 0.3 0.2 # 0 3.3 58 Dec. 23, 1957 SSW 0.1 0.9 1.5 1.4 0.8 0.4 0.1 # 5.2 71 May 26, 1948 SW 0.2 0.7 3.6 3.4 1.7 0.4 0.1 0.1 10.2 72 June 5, 1957 WSW 0.2 1.5 2.7 2.4 1.1 0.2 0 0 8.1 58 Nov. 3, 1958 L W 0.3 2.2 2.1 1.0 0.3 # 0 0 5.9 52 Nov. 4, 1958 L WNW 1.0 9.6 8.0 5.4 0.6 # 0 0 24.6 50 July 19, 1953 NW 1.5 9.6 6.8 5.1 0.8 0 0 0 23.8 49 April 6, 1952 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-50Table 2.3-6 Speed and Direction of Daily Peak Gusts* (Continued) Speed Class (mph) Extreme High and Date of Occurrence ** Direction Under 10 10-19 20-29 30-39 40-49 50-59 60-69 70 orover Total mph Date NNW 0.4 0.8 0.3 # 0 0 0 0 1.5 38 May 8, 1955 N 0.2 1.1 1.4 0.2 0.1 0 0 0 3.0 46 Aug. 27, 1951 Summary 6.6 34.5 31.2 20.3 5.9 1.2 0.2 0.1 100.0 --- ---

• Based on 12 years of observations (1947-58). Tabular values under speed classes denote percent of all daily observations made during the period. L Denotes the latest of several occurrences.

1. Denotes less than .05%.

• • A new record was set on January 11, 1972, when a peak gust of 80 mph was recorded at the 50 foot level at the Hanford Meteorology Station. Reference Document BNWL-1640 "The Hanford Wind Storm of January 11, 1972." dated February 1972, issued by Battelle Pacific Northwest Laboratories.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-51 Table 2.3-7a CGS and HMS Hourly Meteorological Data, August 7-9, 1972 (Ultimate Heat Sink Studies) CGS Site HMS Tower Site Day/Hour Wind Direction (degrees) Wind Speed (mph) Dry Bulb (F) Relative Humidity (percent) Wet Bulb (F) Wind Direction (degrees) Wind Speed (mph) Dry Bulb (F) Wet Bulb (F) Elevation 23 feet 23 feet 3 feet 3 feet 3 feet 50 feet 7 feet 7 feet 7 feet 7/1 7/2 7/3 7/4 7/5 7/6 7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 30 50 160 80 50 70 100 70 70 100 130 140 360 80 110 110 90 60 50 50 40 60 100 30 5 5

5 5

5 4

5 4

4 5

5 5

6 8

8 9

9 9 12 12 8 6

5 4 76 72 71 69 65 61 61 59 67 77 85 91 96 99 102 106 107 108 106 106 103 96 89 85 35 36 44 48 51 64 64 68 66 54 46 38 35 32 30 28 25 24 23 23 22 22 26 34 60 58 59 58 55 54 54 53 59 65 69 71 73 74 76 77 77 77 75 75 73 69 66 66 220 270 300 270 180 110 300 320 320 Variable 40 Variable 90 110 90 Variable 90 90 110 90 130 220 300 270 6 6

5 5

4 2

1 5

3 1

3 3

5 5

4 4

8 8

7 8

7 6

8 5 78 76 78 74 72 67 76 81 85 92 93 98 102 104 105 107 108 106 103 97 90 84 82 81 57 56 57 54 55 53 57 60 61 64 64 66 68 68 69 69 69 68 67 64 62 60 58 58 8/1 8/2 8/3 8/4 8/5 8/6 8/7 8/8 8/9 8/10 8/11 8/12 8/13 8/14 8/15 8/16 8/17 8/18 8/19 8/20 8/21 8/22 8/23 8/24 360 130 40 20 40 80 100 140 130 130 120 70 70 40 60 70 30 30 90 110 320 320 320 320 6 5

5 7

6 5

5 4

5 5

7 7

6 6

7 7

8 8

8 8 19 21 15 15 79 72 70 71 71 67 65 62 67 77 85 90 95 98 101 104 106 108 106 106 108 100 95 91 36 39 42 46 46 46 52 54 56 53 46 40 37 34 32 30 28 27 26 25 26 26 28 28 63 58 58 59 59 56 55 53 57 64 69 71 73 74 76 77 77 78 77 76 78 73 71 68 270 270 200 240 200 300 320 20 140 110 110 60 90 90 130 110 220 270 300 300 300 300 300 270 4 4

4 1

4 5

5 3

2 3

4 4

4 4

4 6 10 16 20 21 21 22 16 16 78 77 78 71 70 69 79 85 87 91 93 97 103 104 106 108 108 106 102 96 91 90 87 85 57 57 57 53 53 53 60 63 63 65 65 67 69 69 70 70 70 68 70 66 66 63 64 63 9/1 9/2 9/3 9/4 9/5 9/6 9/7 9/8 9/9 9/10 9/11 9/12 9/13 9/14 9/15 9/16 9/17 9/18 9/19 9/20 9/21 9/22 9/23 9/24 320 320 180 Variable 150 140 160 200 190 200 180 170 190 200 160 300 250 300 310 320 320 320 320 320 17 10 7 5

6 5

5 7

7 8

6 5

7 10 8 13 13 17 14 20 22 17 13 16 90 89 84 77 72 70 71 68 73 81 89 94 98 100 100 102 104 104 104 102 96 93 87 84 32 32 34 35 46 54 57 58 60 56 50 44 38 34 30 30 28 26 27 26 27 29 30 30 69 68 65 61 60 59 61 59 63 68 72 74 76 76 74 76 76 75 76 74 71 70 66 64 270 240 300 240 270 240 240 220 240 320 320 220 220 220 220 240 300 300 300 300 300 300 300 300 9 6

7 6 11 10 8 6 10 9 6

5 10 15 15 13 16 20 20 17 16 18 19 14 83 82 78 80 82 82 82 87 89 94 96 99 101 101 101 103 102 97 93 88 83 80 79 78 63 61 60 62 63 63 63 65 65 65 66 67 68 67 67 68 68 67 65 63 61 60 60 60 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-52 Table 2.3-7b CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level) (Ultimate Heat Sink Studies) Day/Hour Wind Speedmph Dry Bulb F Dewpoint F Wet Bulb F 4/1 4/2 4/3 4/4 4/5 4/6 4/7 4/8 4/9 4/10 4/11 4/12 4/13 4/14 4/15 4/16 4/17 4/18 4/19 4/20 4/21 4/22 4/23 4/24 3.56 3.66 1.71 4.88 2.96 2.76 5.21 3.33 6.02 5.97 12.36 9.67 9.55 8.89 6.28 5.85 6.13 3.55 3.41 5.64 3.88 3.61 3.97 4.81 66.13 64.91 64.16 62.69 61.87 65.60 72.51 77.12 81.71 83.95 90.00 94.48 97.15 99.57 102.37 103.49 104.27 104.77 103.68 95.64 91.49 86.72 83.92 79.60 53.17 54.85 53.92 53.41 53.57 55.20 55.95 54.84 55.52 57.71 55.57 57.09 57.97 58.00 56.77 54.77 52.40 51.20 49.57 59.28 57.55 56.56 58.68 57.84 58.41 58.86 58.07 57.22 56.99 59.30 62.22 63.26 65.16 67.00 67.88 69.99 71.21 71.93 72.17 71.63 70.88 70.56 69.61 71.39 69.30 67.32 67.50 65.66 5/1 5/2 5/3 5/4 5/5 5/6 5/7 5/8 5/9 5/10 5/11 5/12 5/13 5/14 5/15 5/16 5/17 5/18 5/19 5/20 5/21 5/22 5/23 5/24 4.96 3.90 3.30 6.61 6.06 5.00 5.28 2.94 4.87 8.24 5.82 5.69 6.13 4.74 7.52 6.43 4.65 6.93 6.48 6.79 5.25 6.05 3.95 6.34 76.83 74.83 71.68 70.93 71.15 72.99 77.84 81.95 87.01 92.11 96.69 98.96 100.80 103.79 105.36 105.81 104.53 103.48 101.04 96.64 93.63 89.23 87.41 83.80 57.17 55.47 55.41 54.56 55.57 55.89 57.41 58.51 57.89 56.24 54.80 57.68 60.27 54.99 54.77 55.09 53.25 52.80 57.15 57.79 57.23 56.43 57.25 58.84 64.37 62.79 61.64 60.92 61.54 62.36 64.84 66.78 68.07 68.85 69.61 71.60 73.36 71.81 72.18 72.44 71.31 70.80 71.97 70.97 69.80 68.05 67.88 67.55 6/1 6/2 6/3 6/4 6/5 6/6 6/7 6/8 6/9 6/10 6/11 6/12 6/13 6/14 6/15 6/16 6/17 2.68 6.15 4.87 6.08 5.55 2.14 2.35 4.21 2.96 5.10 13.07 12.58 6.00 4.56 5.09 6.27 9.89 81.71 79.55 76.13 73.41 72.83 74.56 80.99 85.01 86.61 89.49 86.75 83.84 87.87 88.69 91.49 94.56 92.59 59.17 59.15 59.73 59.47 59.39 61.28 63.33 61.95 63.65 61.49 62.85 63.47 60.85 61.47 60.59 59.57 60.03 67.05 66.33 65.54 64.49 64.24 65.91 69.16 69.61 71.04 70.70 70.63 70.10 69.87 70.45 70.83 71.21 70.87 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-53 Table 2.3-7c CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level)* (Ultimate Heat Sink Studies) Day/Hour Wind Speedmph Dry Bulb F Dewpoint F Wet Bulb F 6/18 6/19 6/20 6/21 6/22 6/23 6/24 7.70 3.03 5.58 12.41 8.22 3.64 3.82 93.44 92.59 90.53 87.60 82.43 79.72 79.49 59.81 59.17 59.57 60.93 58.69 56.40 55.65 71.00 70.43 70.02 69.83 67.03 64.94 64.48 7/1 7/2 7/3 7/4 7/5 7/6 7/7 7/8 7/9 7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18 7/19 7/20 7/21 7/22 7/23 7/24 8.39 7.41 8.64 7.31 7.31 8.75 10.86 8.77 10.34 12.46 9.95 10.70 6.33 3.98 8.95 12.70 5.17 3.60 8.61 5.68 4.75 4.06 8.93 16.32 75.23 73.55 72.88 72.67 71.28 74.37 76.77 79.63 83.07 86.32 89.15 90.61 92.80 95.65 95.01 96.85 96.51 97.15 96.40 91.52 86.08 84.35 81.39 81.47 54.69 54.69 53.95 53.68 53.36 55.44 57.23 58.96 59.71 60.35 61.49 60.37 59.71 59.57 58.67 59.31 59.49 58.72 57.76 58.85 61.33 55.89 59.31 60.35 62.52 61.94 61.31 61.10 60.43 62.61 64.38 66.26 67.77 69.13 70.60 70.45 70.76 71.53 70.90 71.76 71.75 71.56 70.88 69.94 69.58 66.22 67.02 67.62 8/1 8/2 8/3 8/4 8/5 8/6 8/7 8/8 8/9 8/10 8/11 8/12 8/13 8/14 8/15 8/16 8/17 8/18 8/19 8/20 8/21 8/22 8/23 8/24 10.89 10.13 11.19 9.25 8.42 8.80 14.06 13.55 M M

M M

M M

M 5.38 5.44 3.66 3.50 6.68 7.28 9.70 9.48 6.22 80.08 79.65 78.05 76.72 74.67 76.45 79.23 80.37 M M

M M

M M

M 101.23 102.03 102.16 100.85 97.09 92.64 89.25 87.49 83.73 58.21 56.69 55.33 54.43 54.53 55.55 56.88 57.60 M M

M M

M M

M 59.09 58.00 56.56 55.28 56.61 56.40 55.25 53.71 54.29 66.01 65.07 63.83 62.91 62.25 63.40 65.03 65.79 M M

M M

M M

M 72.92 72.64 72.02 71.07 70.54 69.09 67.49 66.21 65.24 *M - Missing data COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-54 Table 2.3-7d CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level)* (Ultimate Heat Sink Studies) Day/Hour Wind Speed mph Dry Bulb F Dewpoint F Wet Bulb F 9/1 9/2 9/3 9/4 9/5 9/6 9/7 9/8 9/9 9/10 9/11 9/12 9/13 9/14 9/15 9/16 9/17 9/18 9/19 9/20 9/21 9/22 9/23 9/24 7.99 5.26 3.95 4.58 3.78 4.00 4.67 9.88 12.03 10.18 8.76 5.78 7.10 4.77 5.17 5.12 3.24 6.10 6.18 7.80 13.30 25.82 17.04 11.05 81.52 79.12 74.91 73.12 72.37 75.28 79.79 83.38 85.49 88.13 92.13 95.52 99.49 102.61 106.40 108.03 109.47 109.15 107.44 101.47 99.31 94.16 94.61 92.37 55.81 56.45 58.32 58.69 57.92 59.49 60.16 60.06 60.00 61.28 62.85 64.40 63.17 62.72 58.77 55.28 55.49 53.07 52.35 57.87 53.15 61.36 59.49 57.57 65.25 64.76 64.35 63.94 63.25 65.12 66.98 68.06 68.69 70.18 72.20 74.02 74.46 75.01 74.23 73.15 73.65 72.58 71.79 72.42 69.69 72.01 71.19 69.58 10/1 10/2 10/3 10/4 10/5 10/6 10/7 10/8 10/9 10/10 10/11 10/12 10/13 10/14 10/15 10/16 10/17 10/18 10/19 10/20 10/21 10/22 10/23 10/24 8.36 12.16 9.19 5.08 1.56 6.53 7.10 4.15 3.89 5.12 3.77 5.74 5.89 5.27 5.30 5.90 9.37 12.21 8.55 5.54 4.26 3.14 7.36 12.76 90.91 85.92 84.24 80.61 80.24 78.27 83.25 86.77 90.64 92.64 95.23 98.32 100.91 103.09 105.20 105.71 104.93 102.48 101.15 98.27 96.21 90.72 91.33 91.49 58.03 59.17 57.28 56.21 58.48 59.55 62.99 62.91 61.09 62.00 63.36 62.40 59.41 59.39 58.91 56.00 54.11 55.88 56.05 56.13 56.59 60.53 57.68 60.48 69.35 68.39 66.88 65.14 66.21 66.15 69.65 70.67 70.83 71.90 73.38 73.73 72.98 73.58 73.96 72.80 71.78 71.81 71.50 70.68 70.27 70.57 69.31 70.77 11/1 11/2 11/3 11/4 11/5 11/6 11/7 11/8 11/9 11/10 11/11 7.86 12.03 14.22 6.62 8.70 7.13 12.45 M 10.14 12.86 14.68 89.61 86.81 88.56 87.60 85.47 85.28 82.37 M 83.96 83.57 82.51 61.65 62.03 61.48 59.81 60.11 60.37 61.23 M 62.40 62.53 63.97 70.83 70.20 70.42 69.25 68.74 68.82 68.39 M 69.53 69.49 70.00 *M - Missing data COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-55 Table 2.3-7e CGS Hourly Meteorological Data, July 4-12, 1975 (33 ft Level)* (Ultimate Heat Sink Studies) Day/Hour Wind Speed mph Dry Bulb F Dewpoint F Wet Bulb F 11/12 11/13 11/14 11/15 11/16 11/17 11/18 11/19 11/20 11/21 11/22 11/23 11/24 13.48 11.16 11.36 8.17 4.60 4.39 4.27 11.57 9.70 8.24 6.89 10.12 10.69 84.13 87.73 87.76 89.92 94.72 96.19 96.16 89.28 84.99 83.01 82.00 81.97 78.83 64.96 62.91 63.12 61.81 59.97 59.89 58.85 64.05 61.07 60.69 61.09 59.39 57.81 71.06 70.96 71.08 71.00 71.46 71.85 71.33 72.05 69.10 68.28 68.20 67.25 65.38 12/1 12/2 12/3 12/4 12/5 12/6 12/7 12/8 12/9 12/10 12/11 12/12 12/13 12/14 12/15 12/16 12/17 12/18 12/19 12/20 12/21 12/22 12/23 12/24 10.37 7.69 3.17 2.34 5.74 6.75 6.57 4.62 4.23 4.51 5.53 5.53 5.93 6.81 10.87 12.07 15.02 12.21 15.39 13.48 8.45 7.23 9.74 5.68 77.65 76.64 75.87 75.71 73.92 70.51 73.07 76.88 79.71 82.69 84.13 86.43 88.75 90.69 91.31 87.20 86.96 87.39 83.63 81.47 81.76 81.36 79.41 77.73 57.01 56.85 56.32 56.99 58.64 56.51 57.71 59.63 60.93 61.44 61.01 61.65 62.40 62.93 61.73 60.19 62.24 61.36 62.45 60.80 58.77 54.43 44.32 43.97 64.57 64.14 63.59 63.89 64.18 61.81 63.38 65.73 67.38 68.61 68.81 69.86 70.98 71.85 71.37 69.32 70.36 70.00 69.46 67.87 66.86 64.51 59.39 58.63 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-56 Table 2.3-7f 24 Hour HMS Meteorological Profile for August 4, 1961 Hour Dry Bulb Temp Wet Bulb Temp Dew Pt Wind (mph) F F F F 0 1 2 3 4

5 6

7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 82.0 84.0 86.0 85.0 85.0 85.0 86.0 91.0 92.0 96.0 99.0 103.0 107.0 110.0 112.0 112.0 113.0 110.0 108.0 100.0 98.0 96.0 94.0 93.0 61.0 62.0 63.0 63.0 63.0 62.0 61.0 63.0 63.0 64.0 65.0 67.0 69.0 70.0 71.0 71.0 72.0 70.0 68.0 66.0 66.0 66.0 65.0 64.0 45.0 46.0 48.0 49.0 48.0 46.0 43.0 42.0 42.0 41.0 42.0 44.0 45.0 46.0 48.0 48.0 49.0 45.0 43.0 45.0 45.0 46.0 46.0 45.0 4 5 5 5 5

3 8

7 6

6 7

6 6

5 6

5 5

8 14 19 20 18 16 12 24 Hour Average: Dry Bulb = 96.96 F Wet Bulb = 65.62 F Dew Point = 45.29 F Wind = 8.37 mph COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-57 Table 2.3-7g Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing Second Through Thirtieth Day Pond Thermal Performance (Based On July 9 - August 8, 1961 Hourly Hanford Meteorological Station Data) Hour Dry Bulb (F) Wet Bulb (F) 1 2 3

4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 70.2 68.8 68.3 68.8 70.2 72.5 75.6 79.0 82.8 86.6 90.1 93.1 95.4 96.8 97.3 96.8 95.4 93.1 90.1 86.6 82.8 79.0 75.6 72.5 56.5 56.0 55.8 56.0 56.5 57.3 58.4 59.6 61.0 62.3 63.6 64.7 65.5 66.0 66.2 66.0 65.5 64.7 63.6 62.3 61.0 59.6 58.4 57.3 Daily Average and Variation 82.8 +/- 14.5°F 61.0 +/- 5.2°F COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-58 Table 2.3-7h Diurnal Variation in Dry Bulb and Wet Bulb Temperature for Use in Analyzing First Through Thirtieth Day Maximum Mass Loss (Based On July 2 - August 1, 1960 Hourly Hanford Meteorological Station Data) Hour Dry Bulb (F) Wet Bulb (F) 1 2 3

4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 69.4 67.8 67.3 67.8 69.4 71.9 75.1 78.9 82.9 86.9 90.7 93.9 96.4 98.0 98.5 98.0 96.4 93.9 90.7 86.9 82.9 78.9 75.1 71.9 53.3 52.6 52.4 52.6 53.3 54.3 55.7 57.3 59.0 60.7 62.3 63.7 64.7 65.4 65.6 65.4 64.7 63.7 62.3 60.7 59.0 57.3 55.7 54.3 Daily Average and Variation 82.9 +/- 15.6°F 59.0 +/- 6.6°F

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-59Table 2.3-8a Summary of CGS Onsite Meteorological Data Collected During the First and Second Annual Cycles as Compared to Corresponding Hanford Meteorological Station Data (Historical HMS Data Indicated for Each Month) April May June July August September October Site and Sensor Elevation '74 '75 '74 '75 '74 '75 '74 '75 '74 '75 '74 '75 '74 '75 1. Prevailing Wind Direction CGS 33'HMS 50' HMS (hist) 50' (1955-1970)

WNW SSW WNW N/A WNW SSW NW WNW N/A WNW WNW NW WNW N/A WNW S S WNW N/A WNW S S WNW N/A WNW N N NW N/A NW WNW S NW NWWNW 2. Mean Wind Speed (mph) CGS 33' HMS 50' HMS (hist) 50' (1955-1970) 9.8 8.0 10.3 9.0 9.0 8.4 8.7 9.0 9.6 8.8 8.5 9.3 9.0 10.5 9.2 7.2 7.6 8.1 8.5 8.6 6.8 7.9 7.5 9.0 8.0 6.5 5.7 7.1 6.8 7.5 4.8 7.2 5.6 7.1 6.7 3. Mean Dry Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 52.2 47.6 52.5 48.4 52.5 57.4 59.6 57.9 60.7 61.8 72.5 66.1 73.3 67.3 69.9 73.6 78.7 74.8 80.0 77.5 74.7 70.3 76.3 71.2 75.3 66.9 66.2 68.3 67.9 67.0 51.7 52.1 52.0 52.353.2 4. Mean Wet Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 44.7 39.7 43.9 40.0 42.8 47.2 48.2 46.5 49.0 49.1 56.0 52.7 54.5 54.0 54.5 57.4 61.5 56.3 62.0 57.9 58.0 55.7 57.0 56.0 57.3 52.6 52.0 52.0 52.0 52.6 43.8 45.3 42.0 45.045.4 5. Mean Dew Point Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 36.6 29.8 33.3 30.0 30.4 36.6 36.9 34.0 38.6 36.0 43.0 40.8 38.2 42.4 41.2 44.9 50.2 41.0 50.1 42.3 45.6 44.2 43.2 44.6 42.8 39.9 39.5 38.9 38.2 39.5 35.0 38.2 31.0 37.236.9 6. Total Precipitation (inches) CGS HMS HMS (hist) 1946-1970 Mean Total N/A - Not Available

.55 .53

.46 .42 .44

.44 .47

.28 .38 .50

.06 .46

.12 .14 .66

.45 .09

.71 .32 .16 0.0 1.17 Trace 1.16 .21

.06 0.0

.01 .03 .30

.10 .74

.21 .87 .61 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-60Table 2.3-8a Summary of CGS Onsite Meteorological Data Collected During the First and Second Annual Cycles as Compared to Corresponding Hanford Meteorological Station Data (Historical HMS Data Indicated for Each Month) (Continued) First AnnualCycle Second AnnualCycle November December January February March Site and Sensor Elevation '74 '75 '74 '75 '75 '76 '75 '76 '75 '76 April '74-March '75 April '75- March '76 1. Prevailing Wind Direction CGS 33' HMS 50' HMS (hist) 50' (1955-1970)

SSW S NW NW NW S NWNW NW NW NNW NWNW NWSW NW NW SSWNW NW SW NW NNW SSWWNW NW SW WNW NW NW N/A N/A NW ('55 -'70) 2. Mean Wind Speed (mph) CGS 33' HMS 50' HMS (hist) 50' (1955-1970) 5.8 7.8 5.5 7.7 6.2 6.4 7.1 5.9 7.2 6.0 6.4 5.0 6.4 4.9 6.4 7.8 10.4 7.5 10.8 7.0 8.7 9.1 8.9 9.6 8.4 7.2 7.8 9.1 10.1 7.6 ('55 - '70) 3. Mean Dry Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 42.1 39.5 42.1 39.3 40.1 36.8 34.2 35.7 34.5 33.4 32.3 32.4 32.0 31.5 30.3 33.8 37.7 33.6 37.3 37.5 41.9 40.8 42.0 40.6 44.0 53.1 52.1 53.4 52.6 53.5 ('50 - '70) 4. Mean Wet Bulb Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 39.3 35.5 38.0 35.0 36.4 34.5 31.9 33.0 32.0 31.2 30.0 30.6 30.0 30.0 27.9 30.9 32.9 31.0 33.0 33.6 36.2 34.4 36.0 35.0 37.3 44.3 43.4 43.4 43.6 43.8 ('50 - '70) 5. Mean Dew Point Temp. (°F) CGS 33' HMS 3' HMS (hist) 3' (1950-1970) 36.3 30.6 33.9 30.0 31.1 31.4 28.9 29.2 28.1 27.5 26.3 28.1 26.0 27.6 23.2 26.5 25.4 25.5 25.5 27.4 27.9 24.8 26.0 25.0 27.3 35.9 34.8 33.4 34.8 33.8 ('50 - '70) 6. Total Precipitation (inches) CGS HMS HMS (hist) 1946-1970 Mean Total N/A - Not Available .56 .70

.71 .60 .80 .67 .03 .97 .70 .81 .93 .08 1.43 .56 .97 .67 .11 .98 .36 .58 .52 .16 .33 .23 .38 4.92 4.54 6.21 5.87 6.53 ('46 - '70)

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-61 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) APRIL SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 5 2 8 15 6 4 0 0 0 0 0 0 0 1 19 22 ENEE0 0 1 3 2 3 0 0 0 0 0 0 0 0 0 0 3 6 ESESE0 0 6 4 4 12 1 6 0 1 0 0 0 0 0 0 11 23 SSES0 0 4 8 26 18 21 19 0 12 0 0 0 0 3 7 54 64 SSWSW0 0 4 4 16 18 29 9 30 15 2 4 0 0 13 6 94 56 WSWW0 0 3 3 10 14 12 16 5 17 3 4 1 1 7 8 41 63 WNWNW0 0 7 5 19 23 26 15 40 9 21 11 8 3 2 1 123 67 NNWN0 0 5 3 17 14 5 5 1 1 0 0 0 0 2 0 30 23 VARCALM0 0 2 0 5 0 0 0 0 0 0 0 0 0 0 0 7 0 UNKNOTOTAL0 0 0 69 0 224 0 176 0 131 0 45 0 13 14 64 14 720 MAY SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 5 7 11 3 0 3 0 0 0 0 0 0 0 0 16 13 ENEE0 0 1 8 6 6 2 0 0 0 0 0 0 0 0 0 9 14 ESESE0 0 6 1 9 16 0 1 0 0 0 0 0 0 0 0 15 18 SSES0 0 9 10 38 27 13 45 0 10 0 0 0 0 0 0 60 92 SSWSW0 0 5 3 30 15 49 18 16 13 4 3 2 0 0 0 106 52 WSWW0 0 6 3 19 23 30 35 13 13 1 5 0 0 0 0 69 79 WNWNW0 0 11 4 24 14 34 10 17 13 10 4 0 2 0 0 96 47 NNWN0 0 3 4 13 7 7 1 0 0 0 0 0 0 0 0 23 12 VARCALM0 0 7 0 8 0 0 0 0 0 0 0 0 0 0 0 15 0 UNKNOTOTAL0 0 0 93 0 269 0 248 0 95 0 27 0 4 8 8 8 744 JUNE SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 5 7 12 9 1 4 0 0 0 0 0 0 0 1 18 21 ENE E 0 0 6 3 16 14 9 7 0 0 0 0 0 0 0 0 31 24 ESE SE 0 0 4 4 16 23 6 10 0 0 0 0 0 0 0 0 26 37 SSE S 0 0 7 4 34 20 11 18 0 10 0 2 0 0 0 1 52 55 SSW SW 0 0 6 3 20 11 12 6 12 4 1 5 0 0 0 0 51 29 WSW W 0 0 3 2 15 18 5 14 3 13 1 2 1 3 0 0 28 52 WNW NW 0 0 2 3 24 15 19 20 10 8 10 5 2 2 0 0 67 53 NNW N 0 0 6 6 17 11 3 1 0 0 0 0 0 0 0 0 26 18 VAR CALM 0 0 0 0 4 0 0 0 1 0 0 0 0 0 0 0 5 0 UNKNO TOTAL 0 0 10 81 38 317 26 172 9 70 0 26 0 8 44 46 127 720 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-62 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) JULY SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 3 11 13 12 2 1 0 0 0 0 0 0 0 0 18 24 ENE E 0 0 3 10 9 14 6 6 0 0 0 0 0 0 0 0 18 30 ESE SE 0 0 6 10 18 26 1 4 0 0 0 0 0 0 0 0 25 40 SSE S 0 0 3 6 37 27 16 32 1 5 0 0 0 0 0 0 57 70 SSW SW 0 0 9 7 16 22 18 14 9 6 2 0 0 1 0 0 54 50 WSW W 0 0 6 7 12 14 11 19 3 9 1 0 2 0 0 0 35 49 WNW NW 0 0 5 11 18 18 18 21 17 13 5 4 0 0 0 0 63 67 NNW N 0 0 10 8 25 22 4 5 2 0 0 0 0 0 0 0 41 35 VAR CALM 0 0 5 0 24 0 3 0 0 0 0 0 0 0 0 0 32 0 UNKNO TOTAL 0 0 0 120 0 327 0 181 0 65 0 12 0 3 36 36 36 744 AUGUST SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 16 12 21 19 11 6 0 3 0 2 0 0 0 0 48 42 ENE E 0 0 9 10 6 4 0 4 0 0 0 0 0 0 0 0 15 18 ESE SE 0 0 12 6 9 25 0 1 0 0 0 0 0 0 0 0 21 32 SSE S 0 0 8 7 39 33 16 28 0 4 0 3 0 0 0 0 63 75 SSW SW 0 0 11 8 24 16 17 8 13 0 1 1 0 0 0 0 66 33 WSW W 0 0 9 4 18 13 1 6 0 3 0 0 0 0 0 0 28 26 WNW NW 0 0 8 12 19 27 13 12 22 8 10 8 1 0 0 0 73 67 NNW N 0 0 4 15 35 32 10 10 0 0 0 0 0 0 0 0 49 57 VAR CALM 0 0 12 0 5 0 1 0 0 0 0 0 0 0 0 0 18 0 UNKNO TOTAL 0 0 0 163 0 345 0 144 0 53 0 25 0 1 13 13 13 744 SEPTEMBER SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 19 21 29 11 10 5 11 2 0 0 0 0 0 0 69 39 ENE E 0 0 20 17 20 7 0 0 0 0 0 0 0 0 0 0 40 24 ESE SE 0 0 15 7 11 11 1 3 0 0 0 0 0 0 0 0 27 21 SSE S 0 0 1 8 13 22 7 25 0 4 0 0 0 0 0 0 21 59 SSW SW 0 0 5 12 18 11 11 3 3 3 1 0 0 0 0 0 38 29 WSW W 0 0 8 12 5 10 3 10 1 4 0 0 0 0 0 0 17 36 WNW NW 0 0 9 9 12 19 17 24 12 8 5 4 1 1 0 0 56 65 NNW N 0 0 12 15 29 38 14 28 3 12 0 0 1 0 0 0 59 93 VAR CALM 0 0 10 0 8 0 1 0 0 0 0 0 0 0 0 0 19 0 UNKNO TOTAL 0 0 0 200 0 274 0 162 0 63 0 10 0 3 8 8 8 720 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-63 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) OCTOBER SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 26 26 15 17 1 0 0 0 0 0 0 0 0 0 42 43 ENE E 0 0 26 20 22 4 1 0 0 0 0 0 0 0 0 0 49 24 ESE SE 0 0 15 15 2 19 0 2 0 0 0 0 0 0 0 0 17 36 SSE S 0 0 16 13 21 25 8 13 0 0 0 0 0 0 0 0 45 51 SSW SW 0 0 15 12 21 13 6 1 0 0 0 0 0 0 0 0 42 26 WSW W 0 0 15 12 11 9 2 10 0 5 0 1 0 0 0 0 28 37 WNW NW 0 0 21 17 11 17 15 12 11 7 6 0 0 0 0 0 64 53 NNW N 0 0 29 37 20 24 9 3 2 0 0 0 0 0 0 0 60 64 VAR CALM 0 1 16 0 4 0 0 0 0 0 0 0 0 0 0 0 20 1 UNKNO TOTAL 0 1 0 331 0 255 0 83 0 25 0 7 0 0 42 42 42 744 NOVEMBER SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 18 10 14 13 4 2 0 0 0 0 0 0 2 1 38 26 ENE E 0 0 13 6 10 2 7 0 0 0 0 0 0 0 1 0 31 8 ESE SE 0 0 12 14 3 13 0 7 0 0 0 0 0 0 0 0 15 34 SSE S 0 0 7 12 28 29 15 29 3 5 0 0 0 0 0 0 53 75 SSW SW 0 0 11 12 32 20 14 6 19 8 1 4 0 0 0 0 77 50 WSW W 0 0 9 12 6 14 5 3 2 1 2 2 0 0 0 3 24 35 WNW NW 0 0 22 27 14 34 7 12 5 0 1 1 0 0 2 1 51 75 NNW N 0 0 24 30 34 17 2 3 0 0 0 0 0 0 0 0 60 50 VAR CALM 0 0 11 0 2 0 0 0 0 0 0 0 0 0 0 0 13 0 UNKNO TOTAL 0 0 0 250 0 285 0 116 0 43 0 11 0 0 5 15 5 720 DECEMBER SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 12 9 3 5 2 2 0 0 0 0 0 0 0 0 17 16 ENE E 0 0 5 6 4 1 0 0 0 0 0 0 0 0 0 0 9 7 ESE SE 0 0 8 9 1 6 1 5 0 1 0 0 0 0 0 0 10 21 SSE S 0 0 5 11 26 39 25 35 3 14 1 1 0 0 0 0 60 100 SSW SW 0 0 14 14 23 11 29 9 9 2 4 0 3 0 0 0 82 36 WSW W 0 0 16 20 17 15 6 7 3 3 2 3 1 4 0 0 45 52 WNW NW 0 0 27 17 25 59 21 11 6 3 1 0 1 0 0 1 81 91 NNW N 0 0 29 21 27 12 6 0 0 1 0 0 0 0 0 0 62 34 VAR CALM 0 0 8 0 3 0 1 0 0 0 0 0 0 0 0 0 12 0 UNKNO TOTAL 0 0 0 231 0 277 0 160 0 45 0 12 0 9 9 10 9 744 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-64 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) JANUARY SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 11 13 17 11 6 4 0 0 0 0 0 0 0 0 34 28 ENE E 0 0 10 5 12 10 5 1 0 0 0 0 0 0 6 2 33 18 ESE SE 0 0 15 10 5 14 2 1 0 0 0 1 0 0 1 1 23 27 SSE S 0 0 13 10 17 14 15 16 2 6 1 0 0 0 0 0 48 46 SSW SW 0 0 6 15 18 14 10 5 15 7 3 4 0 2 0 1 52 48 WSW W 0 0 13 8 16 8 4 8 3 4 6 0 3 0 0 0 45 28 WNW NW 0 0 23 20 14 37 13 19 0 3 0 0 0 0 1 10 51 89 NNW N 0 0 29 11 47 17 22 15 0 0 0 0 0 0 4 1 102 44 VAR CALM 0 0 7 0 3 0 1 0 0 0 0 0 0 0 0 0 11 0 UNKNO TOTAL 0 0 0 219 0 274 0 147 0 40 0 15 0 5 17 44 17 744 FEBRUARY SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 15 8 15 8 2 0 0 0 0 0 0 0 0 0 32 16 ENEE0 0 5 4 8 2 0 0 0 0 0 0 0 0 0 0 13 6 ESESE0 0 5 6 5 10 1 3 0 1 0 0 0 0 0 0 11 20 SSES0 0 14 14 20 11 13 18 4 8 1 2 0 0 0 0 52 53 SSWSW0 0 9 4 8 9 10 3 9 9 18 4 1 4 0 0 55 33 WSWW0 0 9 4 7 11 3 6 7 1 4 1 1 1 0 0 31 24 WNWNW0 0 7 12 14 54 9 45 2 10 2 3 1 2 0 0 35 126 NNWN0 0 14 16 45 19 24 19 14 1 0 0 0 0 0 0 97 55 VARCALM0 0 5 0 2 0 1 0 0 0 0 0 0 0 0 0 8 0 UNKNOTOTAL0 0 0 151 0 248 0 157 0 66 0 35 0 10 5 5 5 672 MARCH SPEED CLASS(MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNE NE 0 0 6 5 8 4 5 1 2 0 0 0 0 0 0 0 21 10 ENE E 0 0 4 6 4 2 1 2 0 0 0 0 0 0 0 0 9 10 ESE SE 0 0 9 2 5 6 1 7 0 3 0 0 0 0 0 0 15 18 SSE S 0 0 5 3 24 28 22 35 3 13 0 0 0 0 0 0 54 79 SSW SW 0 0 1 5 15 9 24 14 16 31 6 14 0 0 0 0 62 73 WSW W 0 0 4 1 7 12 12 2 8 0 6 1 0 0 0 0 37 16 WNW NW 0 0 6 13 21 32 19 27 2 6 0 1 4 4 0 0 52 83 NNW N 0 0 9 11 37 18 23 6 12 9 5 0 0 0 0 0 86 44 VAR CALM 0 0 7 0 5 0 0 0 0 0 0 0 0 0 0 0 12 0 UNKNO TOTAL 0 0 0 97 0 237 0 201 0 105 0 33 0 8 63 63 63 744 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-65 Table 2.3-8b Frequency of Occurrence of Wind Direction Versus Speed for CGS 33-ft Level (1974-1975) (Continued) ANNUAL SPEED CLASS (MPH) CALM 1-3 4-7 8-12 13-18 19-24 25-UP UNKNO TOTAL NNENE0 0 141 131 166 127 50 32 13 5 0 2 0 0 2 3 372 300 ENEE0 0 103 98 119 69 31 20 0 0 0 0 0 0 7 2 260 189 ESESE0 0 113 88 88 181 14 50 0 6 0 1 0 0 1 1 216 327 SSES0 0 92 106 323 293 182 313 16 91 3 8 0 0 3 8 619 819 SSWSW0 0 96 99 241 169 229 96 151 98 43 39 6 7 13 7 779 515 WSWW0 0 101 88 143 161 94 136 48 73 26 19 9 9 7 11 428 497 WNWNW0 0 148 150 215 349 211 228 144 88 71 41 18 14 5 13 812 883 NNWN0 0 174 177 346 231 129 96 34 24 5 0 1 0 6 1 695 529 VARCALM0 1 90 0 73 0 8 0 1 0 0 0 0 0 0 0 172 1 UNKNOTOTAL0 0 10 2005 38 3332 26 1945 9 801 0 258 0 64 264 354 347 8760 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-66Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) JANUARY SPEED CLASS (MPH) FEBRUARY SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTALAVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.8 2.0 1.8 1.3 1.8 1.8 2.7 1.6 1.4 1.2 1.4 1.4 1.8 2.4 3.6 3.0 1.3 5.4 1.2 0.8 0.7 0.5 0.6 0.7 1.5 0.8 0.9 1.0 1.4 1.5 2.3 5.6 7.8 2.8 0.1 0.2 0.4 0.2 0.1 0.1 0.2 0.4 0.3 0.4 0.6 1.4 1.7 1.3 5.1 6.6 0.6 0.3 0.1 0.1

0.1 0.2 0.1 0.5 1.0 1.6 0.8 10.6 0.9 1.2 0.1 0.2 0.1 0.1

1. #

0.1 0.2 0.6 0.7 0.4 0.1

0.1

1. #

1. 0.1 0.3 0.3 0.2 #

0.1 0.1

1. 4.7 3.4 2.9 1.9 2.4 2.8 4.8 2.9 3.6 4.8 6.8 6.0 6.1 14.0 19.3 6.5 1.4 5.4 4.3 4.6 4.4 3.0 3.0 3.4 4.0 5.4 7.7 11.5 10.7 8.9 6.3 7.1 6.9 4.2 1.8 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.6 1.8 2.2 1.3 1.3 1.3 1.9 1.2 1.3 1.0 1.0 0.9 1.6 1.9 3.3 2.3 1.3 2.4 1.6 1.3 0.9 0.6 0.7 0.7 1.1 0.8 0.7 1.0 1.6 2.1 3.4 4.9 6.9 2.5 0.2 0.4 0.8 0.2 0.1

0.1 0.3 0.4 0.4 0.8 1.3 2.1 2.9 6.8 6.4 0.8

1. 0.2 0.4 0.2

0.1 0.2 0.3 0.6 1.8 1.4 1.1 1.5 1.5 0.1 #

0.1

0.1 0.5 1.1 0.5 0.2 0.3 0.2

1. #

0.1

0.1 0.2 0.5 0.3 0.1 0.1 0.1

0.1 0.1 0.1

1. 4.8 4.5 3.5 1.9 2.0 2.1 3.4 2.6 2.9 4.2 7.4 7.4 9.3 15.5 18.4 5.7 1.5 2.4 4.5 6.3 3.8 3.3 3.0 3.3 4.0 5.2 6.6 10.5 12.6 10.5 7.8 8.3 7.3 4.8 1.8 TOTAL 38.7 30.1 19.6 7.6 2.6 0.9 0.2 # 100.0 6.2 TOTAL 30.6 31.0 23.8 9.4 3.0 1.5 0.3 100.0 7.1

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05% MARCH SPEED CLASS (MPH) APRIL SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.9 1.4 1.7 0.7 0.9 1.0 1.4 0.6 1.0 0.6 0.8 0.8 1.1 1.1 1.5 1.4 1.3 0.7 1.8 1.6 1.2 0.8 0.8 1.1 1.7 1.1 1.4 1.3 2.0 2.5 3.9 4.4 4.4 2.4 0.2 1.0 0.9 0.3 0.1 0.2 0.2 0.5 0.8 0.7 1.1 2.0 3.0 3.1 5.8 5.3 1.1

1. 0.2 0.6 0.2

0.1 0.1 0.3 0.4 1.2 2.5 2.5 1.2 2.2 1.8 0.2 #

0.1

1. #

0.2 0.7 1.5 1.0 0.2 0.8 0.6

1. #

0.3 0.8 0.4 0.1 0.1 0.1

0.1 0.2 0.2

1. 4.9 4.5 3.5 1.6 1.9 2.4 3.7 2.8 3.7 5.3 9.8 10.4 9.6 14.4 13.7 5.1 1.5 0.7 5.4 6.8 4.8 5.0 4.2 4.4 5.0 7.1 7.4 12.1 13.5 11.7 8.2 9.5 8.9 5.6 2.1 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.6 1.0 1.4 0.6 0.8 0.8 1.0 0.5 0.7 0.7 0.7 0.8 1.1 0.8 1.2 0.9 1.6 0.5 1.6 1.3 1.2 1.0 1.0 1.0 1.5 1.0 1.4 1.5 2.3 2.6 4.2 3.9 3.7 1.9 0.5 0.7 0.6 0.4 0.2 0.5 0.2 0.5 0.8 0.7 1.1 2.1 3.8 4.3 6.0 4.2 0.6 0.3 0.3 0.2 0.1

0.1 0.2 0.3 0.9 2.1 2.5 1.7 4.2 3.2 0.2 #

0.1

0.1 0.4 1.6 1.1 0.5 1.3 1.5

1. #

0.1 0.6 0.4 0.1 0.3 0.4

0.1 0.1

1. # 4.2 3.3 3.2 1.9 2.3 2.0 3.1 2.5 3.2 4.7 9.5 11.3 11.9 16.5 14.2 3.6 2.1 0.5 5.5 6.8 5.3 5.2 5.0 4.5 5.2 6.8 6.7 9.6 12.7 11.4 8.8 11.0 11.0 5.8 2.7 TOTAL 19.9 32.6 26.1 13.5 5.1 1.8 0.5 100.0 8.6 TOTAL 16.7 31.6 26.7 16.3 6.6 1.9 0.2 100.0 9.1

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-67Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) (Continued) MAY SPEED CLASS (MPH) JUNE SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTALAVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEEDN NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.2 0.6 1.0 0.8 0.9 0.9 1.0 0.6 0.6 0.7 0.6 0.9 1.2 0.8 1.2 1.0 1.9 0.6 1.7 1.4 1.5 1.1 1.2 1.0 1.5 1.3 1.7 1.3 2.4 2.7 4.0 3.9 3.6 1.8 1.3 0.9 0.7 1.0 0.3 0.3 0.3 0.6 0.6 0.5 0.8 1.7 3.5 4.4 6.7 4.9 0.7

1. 0.1 0.3 0.1 0.1

0.1 0.2 0.1 0.4 1.1 1.8 1.6 4.7 4.4 0.1 #

0.1

0.1 0.5 0.7 0.2 1.7 2.6

0.1 0.2

0.2 0.5

1. #

1. 3.9 3.0 3.7 2.3 2.4 2.2 3.2 2.7 2.9 3.3 6.4 9.8 11.4 18.0 17.2 3.6 3.2 0.6 5.7 6.7 6.4 5.0 4.7 4.6 5.4 6.4 5.6 7.4 9.6 10.1 8.3 11.2 12.0 5.5 3.2 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 0.9 0.6 0.8 0.4 0.5 0.6 0.7 0.5 0.6 0.4 0.7 0.6 0.7 0.6 0.7 0.6 1.6 0.3 2.0 1.8 1.4 1.0 1.3 1.3 1.6 1.1 1.7 1.5 2.5 2.5 4.1 3.5 3.7 2.0 1.7 0.9 0.8 0.8 0.4 0.3 0.3 0.4 0.4 0.3 0.7 2.0 3.5 4.4 6.9 5.1 0.8

1. 0.2 0.4 0.5 0.1

0.1 0.1 0.2 1.0 1.5 1.6 6.2 5.4 0.1 #

0.1

1. 0.1 0.3 0.4 0.3 2.1 3.4

0.1

0.4 0.7

1. #

1. 4.0 3.6 3.6 1.9 2.1 2.2 2.7 2.1 2.7 2.9 6.5 8.6 11.1 19.7 19.0 3.5 3.3 0.3 6.0 7.1 7.5 6.5 5.6 5.0 5.2 5.8 5.5 7.3 8.8 9.7 8.8 12.1 13.0 6.3 3.4 TOTAL 16.5 33.4 27.9 15.1 5.9 1.0 # 100.0 8.7 TOTAL 11.8 34.7 28.0 17.4 6.7 1.2 100.0 9.3

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05% JULY SPEED CLASS (MPH) AUGUST SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.1 0.7 0.9 0.5 0.7 0.7 0.9 0.4 0.7 0.5 0.8 0.7 1.0 0.7 0.9 0.8 2.6 0.4 2.6 2.1 2.1 1.2 1.5 1.3 1.7 1.0 1.5 1.3 2.3 3.0 4.4 4.2 3.8 2.0 1.8 0.6 0.8 0.5 0.2 0.3 0.3 0.3 0.4 0.2 0.5 1.7 2.8 3.5 7.7 5.6 0.7

1. 0.1 0.2 0.2

1. #

0.1 0.2 1.0 1.4 0.9 4.8 5.1 0.1

0.4 0.4 0.1 1.8 3.0

0.1 0.2

0.2 0.5

1. 4.4 3.8 3.7 1.9 2.5 2.3 2.9 1.8 2.5 2.5 6.3 8.5 9.9 19.4 18.9 3.6 4.4 0.4 5.3 6.0 5.7 5.0 4.9 4.9 4.9 5.6 5.3 6.5 9.1 9.5 7.7 11.2 12.4 5.8 3.3 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.3 1.0 1.3 0.7 0.9 0.8 1.1 0.7 0.8 0.6 1.0 0.9 1.3 0.9 1.2 1.0 2.8 0.6 2.5 1.8 1.6 1.1 1.3 1.6 1.8 1.1 1.4 1.6 2.7 3.2 5.1 4.1 3.8 2.3 1.3 0.4 0.5 0.3 0.1 0.2 0.3 0.5 0.6 0.3 0.7 1.6 2.9 4.1 7.6 5.1 0.5 0.1 0.1 0.1

1. #

0.2 0.8 1.4 0.7 4.1 4.5 0.1

1. 0.1 0.2 0.1

1.3 2.3

0.1 0.1 0.2 0.5

1. 4.3 3.4 3.3 1.9 2.4 2.7 3.4 2.4 2.5 3.2 6.4 8.6 11.2 18.2 17.4 3.9 4.1 0.6 5.0 5.1 4.4 4.3 4.5 4.7 4.8 5.5 4.8 6.6 8.1 8.5 7.5 10.6 11.8 5.4 3.0 TOTAL 15.0 37.8 26.1 14.1 5.7 1.0 100.0 8.6 18.9 38.3 25.7 12.1 4.0 0.9 # 100.0 7.9

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-68Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) (Continued) SEPTEMBER SPEED CLASS (MPH) OCTOBER SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEEDDIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 1.9 1.5 1.8 1.3 1.6 1.2 1.4 0.9 0.9 0.8 0.8 1.0 1.3 1.2 1.4 1.3 2.0 1.2 2.4 1.8 1.8 0.9 1.1 1.5 2.1 1.3 1.3 1.6 2.1 3.0 4.9 4.0 3.6 2.6 0.6 0.9 1.0 0.6 0.1 0.2 0.2 0.4 0.5 0.3 0.5 1.3 2.7 3.7 5.6 4.9 0.9 0.3 0.4 0.3 0.1

1. #

0.1 0.1 0.2 1.0 1.3 0.8 2.9 3.3 0.2 #

0.1 0.1

0.1 0.5 0.6 0.3 0.9 1.4

1. #

0.1 0.3 0.1 0.1 0.1 0.2

1. 5.5 4.8 4.6 2.4 2.9 2.9 3.9 2.8 2.6 3.3 6.0 8.7 11.1 14.7 14.8 5.0 2.6 1.2 5.3 6.4 5.6 3.9 3.7 4.1 4.6 5.3 5.2 7.0 9.9 9.4 7.6 9.8 10.5 5.7 2.6 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.6 2.1 2.4 1.4 1.8 1.8 2.5 1.0 1.1 1.0 1.0 1.0 1.7 1.7 2.4 2.1 1.6 2.7 1.7 1.1 0.8 0.7 0.9 1.4 1.9 1.5 1.4 1.4 2.0 2.8 4.6 4.7 4.4 2.5 0.1 0.4 0.3 0.2 0.1 0.1 0.1 0.6 0.7 0.5 0.7 1.5 3.0 3.6 5.0 4.0 0.6

1. 0.1 0.1 0.1

0.1 0.1 0.3 0.7 1.4 1.6 0.7 1.4 1.6 0.1

0.2 0.5 1.0 0.6 0.1 0.4 0.4

0.2 0.4 0.1

0.1

1. 4.8 3.6 3.5 2.2 2.8 3.3 5.1 3.3 3.5 4.5 7.3 9.1 10.7 13.2 12.9 5.3 1.7 2.7 3.9 3.9 3.5 3.6 3.1 3.6 4.2 5.7 6.7 9.7 11.3 9.5 7.1 8.1.

8.0 4.7 1.8 TOTAL 23.5 36.6 23.8 11.0 4.0 0.9 100.0 7.5 TOTAL 31.9 33.9 21.4 8.3 3.2 0.8 # # 100.0 6.7

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05% NOVEMBER SPEED CLASS (MPH) DECEMBER SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTAL AVG SPEED N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.7 2.2 1.9 1.8 1.9 2.0 2.5 1.4 1.7 1.4 1.6 1.3 2.1 2.5 3.6 3.0 1.4 4.7 1.3 0.7 0.5 0.4 0.6 1.0 1.4 1.2 1.2 1.2 1.6 2.1 3.4 4.6 5.9 2.8 0.1 0.4 0.4 0.1

0.1 0.3 0.4 0.5 0.8 1.4 1.9 1.9 4.9 4.7 1.0 0.2 0.2

0.1 0.2 0.5 0.9 1.5 1.3 0.6 1.0 0.7 0.2 #

0.1 0.3 0.7 0.8 0.4 0.1 0.3 0.1

1. #

0.2 0.3 0.1 0.1 0.1 0.1

0.1 0.1

1. #

1. 4.6 3.5 2.5 2.2 2.5 3.1 4.3 3.3 4.2 5.3 7.3 7.1 8.2 13.4 15.1 7.0 1.5 4.7 4.0 4.0 2.8 2.5 2.6 3.1 3.9 5.3 6.8 9.9 10.5 9.1 6.8 7.5 6.6 4.6 1.6 N NNE NE ENE E

ESE SE SSE S

SSW SW WSW W

WNW NW NNW VAR CALM 2.7 1.6 1.7 1.5 1.6 1.9 2.6 1.7 1.7 1.3 1.5 1.6 2.1 2.9 3.8 2.9 1.5 6.8 1.0 0.6 0.5 0.5 0.6 0.7 1.2 1.2 0.8 0.7 1.3 1.8 2.7 5.7 7.3 2.4 0.1 0.3 0.2

0.1 0.2 0.4 0.2 0.4 0.6 1.2 1.7 1.5 5.3 6.0 0.9 0.2

1. #

0.1 0.1 0.2 0.4 0.8 1.4 1.1 0.5 0.8 1.0 0.1

1. # 0.1 0.2 0.5 1.0 0.4 0.1 0.1 0.1

0.1 0.4 0.5 0.1

0.1 0.1

1. 4.2 2.4 2.2 2.0 2.3 2.9 4.3 3.4 3.6 4.4 7.0 6.7 6.9 14.8 18.2 6.3 1.6 6.8 3.5 3.6 2.6 2.4 2.9 3.6 3.6 4.7 6.7 11.1 11.8 8.6 6.0 6.9 6.7 4.3 1.7 TOTAL 39.7 30.0 18.8 7.4 2.8 0.9 0.2 # 100.0 6.1 TOTAL 41.4 29.1 19.0 6.7 2.5 1.1 0.2 # # 100.0 5.9

1. DENOTES LESS THAN 0.05%

1. DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-69Table 2.3-9 Percentage Frequency Distribution of 50-ft Wind Direction Versus Speed at HMS (1955-1970) (Continued) COMPOSITE OF ALL MONTHS SPEED CLASS (MPH) DIRECTION 0-3 4-7 8-12 13-18 19-24 25-31 32-38 39-46 46 TOTALAVG SPEED N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW VAR CALM 2.0 1.4 1.6 1.0 1.2 1.2 1.6 0.9 1.0 0.9 1.0 1.0 1.4 1.5 2.1 1.7 1.7 2.2 1.8 1.4 1.2 0.8 1.0 1.1 1.6 1.1 1.3 1.3 2.0 2.5 3.9 4.5 4.9 2.3 0.7 0.6 0.6 0.4 0.2 0.2 0.2 0.4 0.5 0.4 0.7 1.6 2.7 3.2 6.1 5.2 0.8 # 0.2 0.3 0.2 # # # 0.1 0.1 0.2 0.6 1.4 1.6 1.0 2.9 2.8 0.1 #

1. # # # # # # 0.1 0.3 0.8 0.5 0.2 0.9 1.3 # #

1. # #

1. # 0.2 0.3 0.2 # 0.1 0.3 #

1. 0.1 # # # # #

1. # #

1. 4.6 3.7 3.4 2.0 2.4 2.5 3.7 2.0 3.0 4.0 7.2 8.5 9.7 16.0 16.6 4.9 2.4 2.2 4.9 5.7 4.9 4.1 3.9 4.0 4.5 5.7 6.4 9.5 10.9 9.9 7.7 9.7 9.6 5.1 2.7 TOTAL 25.4 33.4 23.8 11.5 4.1 1.1 0.1 # # 100.0 7.6 # DENOTES LESS THAN 0.05%

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-70Table 2.3-10 Percent Frequency of Occurrence of Wind Direction at the Hanford Reservation* WIND DIRECTION MONTH/YEAR/SITE/ELEVATION NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW N VARI-ABLE CALM 4/74 CGS 33' 4/74 CGS (temp) 23' 4/74 HMS 50' April (1955-1970) HMS (hist) 50' 2.64 2.64 1.53 3.2 3.06 3.61 2.36 3.2 0.42 1.11 1.25 2.0 0.83 1.81 1.53 2.3 1.53 3.75 1.94 2.0 3.19 4.72 2.64 3.1 7.50 6.81 2.50 2.5 8.89 10.42 1.81 3.2 13.06 6.11 3.61 4.7 7.78 4.31 6.81 9.5 5.69 4.72 15.28 11.2 8.75 10.28 13.19 11.8 17.08 16.11 22.08 16.6 9.31 7.50 17.08 14.3 4.17 2.36 2.78 3.7 3.19 2.92 1.53 4.2 0.97 3.19 1.67 2.1 0.00 0.00 0.42 0.4 5/74 CGS 33' 5/74 CGS (temp) 23' 5/74 HMS 50' May (1955-1970) HMS (hist) 50' 2.15 0.94 1.88 3.1 1.75 2.69 1.34 3.7 1.21 0.94 0.81 2.3 1.88 2.82 1.75 2.4 2.02 2.28 3.36 2.2 2.42 4.57 1.88 3.3 8.06 8.20 1.75 2.7 12.37 11.83 2.15 2.8 14.25 9.14 4.70 3.3 6.99 6.32 8.47 6.4 9.27 7.53 14.92 9.8 10.62 8.20 14.25 11.4 12.90 8.06 21.24 18.1 6.32 5.24 13.31 17.2 3.09 2.55 1.75 3.6 1.61 1.48 1.88 3.9 2.02 6.05 3.90 3.2 0.00 0.13 0.67 0.6 6/74 CGS 33' 6/74 CGS (temp) 23' 6/74 HMS 50' June (1955-1970) HMS (hist) 50' 2.50 3.06 1.94 3.6 2.92 4.72 2.92 3.7 4.31 3.75 2.22 2.0 3.33 4.44 2.50 2.2 3.61 7.22 3.75 2.2 5.14 7.50 4.03 2.8 7.22 7.78 2.64 2.1 7.64 6.67 2.36 2.6 7.08 6.53 3.06 3.0 4.03 5.42 4.44 6.5 3.89 3.61 7.22 8.5 7.22 4.86 6.25 11.2 9.31 10.0 24.03 19.6 7.36 10.0 19.58 18.9 3.61 4.72 4.72 3.5 2.50 2.22 2.36 3.9 0.69 7.50 5.56 3.3 0.00 0.00 0.42 0.4 7/74 CGS 33' 7/74 CGS (temp) 23' 7/74 HMS 50' July (1955-1970) HMS (hist) 50' 2.42 3.63 2.82 3.8 3.23 4.30 1.88 3.8 2.42 3.49 2.96 2.0 4.03 3.09 2.55 2.5 3.36 5.51 3.90 2.3 5.38 5.78 3.76 2.9 7.66 8.60 2.69 1.9 9.41 9.14 3.76 2.5 7.26 10.22 2.96 2.5 6.72 3.36 5.11 6.3 4.70 3.76 12.50 8.4 6.59 4.30 12.90 9.9 8.47 5.65 16.53 19.5 9.01 12.50 11.96 18.9 5.51 5.78 2.96 3.5 4.70 3.76 2.42 4.5 4.30 6.99 8.33 4.4 0.00 0.13 0.00 0.4 8/74 CGS 33' 8/74 CGS (temp) 23' 8/74 HMS 50' August (1955-1970) HMS (hist) 50' 6.45 6.72 5.65 3.4 5.65 8.87 3.49 2.9 2.02 4.03 2.55 2.0 2.42 4.03 2.42 2.4 2.82 3.76 2.69 2.7 4.30 5.38 2.55 3.4 8.47 10.48 2.55 2.4 10.08 10.62 2.96 2.5 8.87 5.51 3.49 3.2 4.44 3.49 3.36 6.4 3.76 2.42 7.12 8.6 3.49 2.69 10.62 11.3 9.81 7.39 16.80 18.3 9.01 8.74 16.13 17.4 6.59 7.12 5.65 3.9 7.66 3.49 4.97 4.4 2.42 4.30 6.18 4.2 0.00 0.40 0.81 0.6 9/74 CGS 33' 9/73 CGS (temp) 23' 9/73 HMS 50' September (1955-1970) HMS (hist) 50' 9.58 4.72 7.36 4.9 5.42 6.11 4.86 4.6 5.56 3.61 1.67 2.4 3.33 4.86 3.75 2.9 3.75 3.75 2.50 2.8 2.92 5.42 2.50 3.9 2.92 7.92 2.64 2.7 8.19 8.47 2.92 2.8 5.28 5.28 3.61 3.4 4.03 4.72 4.58 6.0 2.36 2.36 8.61 8.8 5.00 3.75 6.81 11.0 7.78 7.36 15.28 14.7 9.03 6.94 15.97 14.8 8.19 7.08 7.22 4.9 12.92 8.47 4.03 5.6 2.64 9.17 3.06 2.6 0.00 0.00 2.64 1.2 10/74 CGS 33' 10/73 CGS (temp) 23' 10/73 HMS 50' October (1955-1970) HMS (hist) 50' 5.65 3.76 2.42 3.5 5.78 4.70 3.76 3.6 6.59 2.69 2.15 2.3 3.23 4.30 1.75 2.8 2.28 3.63 3.23 3.3 4.84 6.85 3.63 5.1 6.05 9.68 2.96 3.4 6.85 11.96 3.23 3.5 5.65 7.53 5.65 4.5 3.49 5.51 10.89 7.4 3.76 1.75 11.16 9.2 4.97 4.84 9.27 10.7 8.60 7.12 14.78 13.2 7.12 6.85 11.42 12.9 8.06 4.97 4.84 5.4 8.60 3.23 2.82 4.7 2.69 8.20 1.48 1.8 0.13 0.27 4.57 2.7

• For some months, when concurrent measurements are not available for all sites shown; previous year data is given.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-71Table 2.3-10 Percent Frequency of Occurrence of Wind Direction at the Hanford Reservation* (Continued) WIND DIRECTION MONTH/YEAR/SITE/ELEVATION NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW N VARI-ABLE CALM 11/74 CGS 33' 11/73 CGS (temp) 23' 11/73 HMS 50' November (1955-1970) HMS (hist) 50' 5.28 2.22 3.33 3.4 3.61 4.86 1.67 2.6 4.31 1.81 1.81 2.3 1.11 1.53 1.81 2.5 2.08 4.44 3.61 3.1 4.72 8.19 6.11 4.4 7.36 9.72 3.06 3.3 10.42 8.19 5.00 4.2 10.69 5.42 6.25 5.2 6.94 2.22 7.50 7.4 3.33 2.22 4.86 7.1 4.86 5.69 5.42 8.4 7.08 16.25 13.89 13.4 10.42 8.06 19.31 15.1 8.33 3.75 5.97 7.0 6.94 2.92 4.44 4.6 1.81 3.61 0.56 1.4 0.00 0.28 5.42 4.6 12/74 CGS 33' 12/73 CGS (temp) 23' 12/73 HMS 50' December (1955-1970) HMS (hist) 50' 2.28 2.28 2.02 2.5 2.15 5.38 1.48 2.3 1.21 2.28 2.15 1.9 0.94 2.82 2.28 2.3 1.34 3.76 2.28 2.8 2.82 7.53 3.49 4.2 8.06 9.95 3.49 3.4 13.44 10.62 4.30 3.5 11.02 5.24 4.70 4.4 4.84 3.09 7.12 7.1 6.05 2.02 8.20 6.8 6.99 4.30 9.54 6.9 10.89 9.41 13.84 14.8 12.23 10.48 20.02 18.2 8.33 4.84 4.57 6.3 4.57 2.82 1.75 4.2 1.61 7.93 2.15 1.6 0.00 0.67 6.59 6.8 1/75 CGS 33' 1/74 CGS (temp) 23' 1/74 HMS 50' January (1955-1970) HMS (hist) 50' 4.57 2.28 2.69 3.4 3.76 1.88 3.09 2.9 4.44 1.08 2.02 1.9 2.42 1.88 1.34 2.4 3.09 3.09 2.55 2.8 3.63 4.97 4.57 4.7 6.45 7.12 4.03 3.1 6.18 13.17 4.03 3.6 6.99 17.34 5.24 4.9 6.45 8.20 16.67 6.7 6.05 3.23 13.04 6.0 3.76 3.23 7.66 6.1 6.85 5.51 7.53 14.2 11.96 6.32 9.81 19.5 13.71 3.49 4.30 6.4 5.91 1.88 3.09 4.6 1.48 4.70 1.21 1.4 0.00 1.61 4.70 5.4 2/75 CGS 33' 2/74 CGS (temp) 23' 2/74 HMS 50' February (1955-1970) HMS (hist) 50' 4.76 1.04 2.08 4.4 2.38 1.79 2.68 3.5 1.93 1.34 2.08 1.9 0.89 1.64 1.19 2.1 1.64 4.32 4.17 2.2 2.98 7.44 4.46 3.4 7.74 9.08 2.83 2.7 7.89 13.54 5.36 2.9 8.18 13.39 8.63 4.2 4.91 6.25 10.57 7.5 4.61 7.14 12.95 7.4 3.57 5.21 10.86 9.3 5.21 8.33 10.12 15.4 18.76 5.65 10.71 18.4 14.43 2.38 4.91 5.8 8.18 1.34 2.38 5.0 1.19 8.93 2.23 1.5 0.00 0.19 1.79 2.4 3/75 CGS 33' 3/74 CGS (temp) 23' 3/74 HMS 50' March (1955-1970) HMS (hist) 50' 2.82 1.61 1.75 4.5 1.34 2.55 2.69 3.5 1.21 2.02 2.02 1.7 1.34 2.82 1.61 2.0 2.02 1.61 1.21 2.3 2.42 6.59 4.84 3.7 7.26 6.72 3.76 2.8 10.62 10.08 4.30 3.8 8.33 10.08 7.12 5.4 9.81 7.66 15.05 9.9 4.97 4.84 10.75 10.4 2.15 5.65 9.01 9.6 6.99 6.72 11.16 14.4 11.16 6.72 13.04 13.7 11.56 4.57 5.65 5.0 5.91 3.23 2.82 5.1 1.61 9.41 2.82 1.5 0.00 1.08 0.40 0.7 April 1974-March 1975 CGS 33' 1955-1970 HMS (hist) 50' 4.25 3.7 3.42 3.4 2.97 2.0 2.16 2.4 2.47 2.6 3.73 3.7 7.07 2.8 9.35 3.2 8.89 4.1 5.88 7.2 4.89 8.5 5.67 9.8 9.27 16.0 10.08 16.6 7.93 4.9 6.04 4.5 1.96 2.4 0.01 2.2

• For some months, when concurrent measurements are not available for all sites shown; previous year data is given.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-72 Table 2.3-11 Persistence of Wind Direction in One Sector (22.5 Degrees) from 4/74 through 3/75 at 33-ft Level (Stability Based On Temperature Difference) DATE STARTED DAY HOUR WIND DIR HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 400 22 NW 14 0 0 3 11 0 V UNS UNSTA NEUTR M STA V STA .00

.00 10.30 11.08 .00 171 10 S

10 0 1 7

2 0 UNKNO

V UNS UNSTA NEUTR M STA .00 16.00 18.14 15.00 .00

295 15

NNW

10 0 0 0 1

2 V STA UNKNO

V UNS UNSTA NEUTR .00

.00 .00 19.57 21.18

327 14

NW

10 7 0

0 0 0 M STA V STA UNKNO

V UNS UNSTA 9.98 .00

.00 .00

.00

425 6

NNW

10 5 5

0 0 0 NEUTR M STA V STA UNKNO

V UNS 3.81 4.06 .00

.00 .00 1 7 2

0 0 UNSTA NEUTR M STA V STA UNKNO 5.53 5.84 6.81 .00

.00 134 7 SSW 9 0 1 8

0 0 0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 23.78 19.54 .00 .00 .00 219 17 WNW 9 0 2

2 5

0 V UNS UNSTA NEUTR M STA V STA .00 17.34 22.97 16.69 .00 393 2 NW 9 0 0

9 0

V UNS UNSTA NEUTR M STA .00

.00 #999.0 (missing data) .00

404 2

NNW

9 0 0 0 0

1 V STA UNKNO

V UNS UNSTA NEUTR .00

.00 .00

.00 13.63 8 0 0 M STA V STA UNKNO 11.18 .00

.00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-73 Table 2.3-11 Persistence of Wind Direction in One Sector (22.5 Degrees) from 4/74 through 3/75 at 33-ft Level (Continued) (Stability Based on Temperature Difference) DATE STARTED DAY HOUR WIND DIR HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 407 5 SSW 9 0 0 V UNS UNSTA .00

.00

102 13

WNW

8 2 7

0 0 0 NEUTR M STA V STA UNKNO

V UNS 17.20 20.64 .00

.00 .00 5 1 2

0 0 UNSTA NEUTR M STA V STA UNKNO 16.67 19.07 16.91 .00

.00 132 13 WNW 8 0 6 1

1 0

0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 22.17 22.06 17.06 .00

.00 244 11 NNE 8 0 7

1 0

0 V UNS UNSTA NEUTR M STA V STA .00 15.35 12.87 .00

.00 271 16 NW 8 0 0 1

2 5 UNKNO

V UNS UNSTA NEUTR M STA .00 .00 18.52 16.92 11.63

363 10

S

8 0 0 0 0

5 V STA UNKNO

V UNS UNSTA NEUTR .00

.00 .00

.00 13.70

396 21

NW

8 3 0

0 0 0 M STA V STA UNKNO

V UNS UNSTA 13.80 .00

.00 .00

.00

401 12

NNW

8 4 4

0 0

0 0 NEUTR M STA V STA UNKNO V UNS UNSTA 9.10 8.16 .00

.00

.00

.00

402 6

N

8 5 3 0 0 0 NEUTR M STA V STA UNKNO

V UNS 12.80 11.49 .00

.00 .00 0 7 1

0 0 UNSTA NEUTR M STA V STA UNKNO .00 9.04 9.99 .00

.00 426 14 SW 8 0 2 3

3 0

0 V UNS UNSTA NEUTR V STA V STA UNKNO .00 18.58 16.88 15.28 .00

.00 430 8 NNW 8 0 6

1 1

0 V UNS UNSTA NEUTR M STA V STA .00 10.54 10.68 7.82 .00 0 UNKNO .00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-74 Table 2.3-12 Persistence of Wind Direction in Two Sectors (45 Degrees) from 4.74 through 3/75 at CGS for 33-ft Level (Stability Based on Temperature Difference) DATE STARTED DAY HOUR WIND DIRECTIONS HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 400 22 NW NNW 26 0 0 8 15 3 V UNS UNSTA NEUTR M STA V STA .00 .00 11.80 11.05 6.23 379 12 NW NNW 23 0 0 0 6 17 UNKNO V UNS UNSTA NEUTR M STA .00 .00

.00 3.73 3.78 399 23 NW NNW 22 0 0 0 0 7 V STA UNKNO V UNS UNSTA NEUTR .00

.00 .00 .00 15.79 424 21 NW NNW 20 15 0 0 0 2 M STA V STA UNKNO V UNS UNSTA 12.65 .00 .00 .00 4.20 102 1 NNW NW 19 8 10 0 0 0 NEUTR M STA V STA UNKNO V UNS 5.88 7.18 .00

.00 .00 8 2 9 0 0 UNSTA NEUTR M STA V STA UNKNO 18.20 28.03 21.20 .00 .00 400 17 WNW NW 19 0 0 3 16 0 0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 .00 10.30 11.44 .00 .00 244 5 N NNE 18 0 7 7 4 0 V UNS UNSTA NEUTR M STA V STA .00 15.35 15.01 9.66 .00 404 2 NNW N 18 0 0 0 9 9 UNKNO V UNS UNSTA NEUTR M STA .00 .00

.00 11.56 10.83 431 10 NW NNW 18 0 0 0 5 5 V STA UNKNO V UNS UNSTA NEUTR .00

.00 .00 17.79 17.77 171 3 S SSW 17 8 0 0 1 8 M STA V STA UNKNO V UNS UNSTA 8.45 .00 .00 16.00 18.37 224 17 NNW NW 17 5 3 0 0 0 NEUTR M STA V STA UNKNO V UNS 16.60 13.33 .00

.00 .00 4 3 10 0 0 UNSTA NEUTR M STA V STA UNKNO 10.07 14.39 12.00 .00

.00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-75 Table 2.3-12 Persistence of Wind Direction in Two Sectors (45 Degrees) from 4.74 through 3/75 at CGS for 33-ft Level (Continued) (Stability Based on Temperature Difference) DATE STARTED DAY HOUR WIND DIRECTIONS HOURS OF PERSISTENCE HOURS EACH STABILITY AVERAGE SPEED (MPH) 401 21 NNW N 17 0 0 7 3

7 0 V UNS UNSTA NEUTR M STA V STA UNKNO .00

.00 9.04 8.95 6.78 .00 406 21 SSW SW 17 0 0

2 15 0 V UNS UNSTA NEUTR M STA V STA .00

.00 17.20 21.52 .00 438 1 SSE S 17 0 0 2

2 7 UNKNO

V UNS UNSTA NEUTR M STA .00 .00 7.67 5.47 7.21

396 17

WNW NW

16 6 0 0 0 10 V STA UNKNO

V UNS UNSTA NEUTR 8.80 .00 .00

.00 8.80

423 8

NW NNW

16 6 0

0 0 0 M STA V STA UNKNO

V UNS UNSTA 7.94 .00

.00 .00

.00

98 11

WNW NW

15 10 6 0

0 0 3 NEUTR M STA V STA UNKNO

V UNS UNSTA 7.61 5.58 .00

.00 .00 15.67

253 15

WNW NW

15 4 8

0 0 0 NEUTR M STA V STA UNKNO

V UNS 14.00 11.62 .00

.00 .00 0 2 9

4 0 UNSTA NEUTR M STA V STA UNKNO .00 16.41 11.59 7.27 .00 293 11 W WNW 15 0 4 3

8 0

0 V UNS UNSTA NEUTR M STA V STA UNKNO .00 16.25 18.27 9.39 .00

.00 355 6 WSW W 15 0 0

7 8

0 V UNS UNSTA NEUTR M STA V STA .00

.00 25.65 15.14 .00 0 UNKNO .00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-76Table 2.3-12a Longest Persistence of Wind Direction in One (22.5 Degrees) and Two (45 Degrees) Sectors During First and Second Annual Cycles at 33-ft Level (Stability Based on Temperature Difference) First Annual Cycle (April '74 - March '75) Second Annual Cycle (April '75 - March '76)

MONTH WIND DIRECTION HOURS OF PERSISTENCE HOURS OF EACH STABILITY AVERAGE WIND SPEED MONTH WIND DIRECTION HOURS OF PERSISTENCE HOURS OF EACH STABILITY AVERAGE WIND SPEED January NW 14 0 0

3 11 0 0

V UNS UNSTA NEUTR M STA V STA UNKNO

.00

.00 10.30 11.08 .00 .00 February NNE 33 0 3 10 20 0 0 V UNS UNSTA NEUTR M STA V STA UNKNO

.00 30.22 29.04 23.15 .00 .00 January NW, NNW 26 0 0

8 15 3 0

V UNS UNSTA NEUTR M STA V STA UNKNO

.00

.00 11.86 11.05 6.23 .00 January N, NNE 35 0 3 10 22 0 0

V UNS UNSTA NEUTR M STA V STA UNKNO

.00 30.22 29.04 21.84 .00

.00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-77Table 2.3-13 Percent Frequency of Occurrence of Wind Speed at the Hanford Reservation (1) Wind Speed Range, mph (2) Month/Year/Site/Elevations Calm 1-3 4-7 8-12 13-18 19-24 25-Up Average Speed (mph) 4/74 CGS 33' 4/74 CGS (temp) 23' 4/74 HMS 50' April (1955-1970) HMS (hist) 50' 0.00 0.00 0.42 9.58 13.19 9.72 16.8 31.11 37.50 26.11 31.6 24.17 23.47 33.33 26.6 18.19 17.78 19.72 16.2 6.25 4.72 7.64 6.6 1.81 0.42 3.06 2.2 9.8 8.7 10.3 9.0 5/74 CGS 33' 5/74 CGS (temp) 23' 5/74 HMS 50' May (1955-1970) HMS (hist) 50' 0.00 0.13 0.67 12.50 14.11 12.63 16.6 36.16 38.17 30.11 33.3 33.33 28.23 32.66 27.9 12.77 11.96 18.15 15.1 3.63 2.55 5.38 6.0 0.54 0.67 0.40 1.1 8.4 7.9 9.0 8.8 6/74 CGS 33' 6/74 CGS (temp) 23' 6/74 HMS 50' June (1955-1970) HMS (hist) 50' 0.00 0.00 0.42 11.25 21.67 13.61 11.7 44.03 47.64 35.42 34.6 23.89 18.06 26.11 28.1 9.72 9.03 15.69 17.4 3.61 3.06 7.64 6.8 1.11 0.56 1.11 1.4 8.5 6.9 9.0 9.2 7/74 CGS 33' 7/74 CGS (temp) 23' 7/74 HMS 50' July (1955-1970) HMS (hist) 50' 0.00 0.13 0.00 16.13 25.40 16.26 15.0 43.95 45.30 38.44 37.8 24.33 19.89 27.28 26.2 8.74 8.06 13.44 14.2 1.61 1.21 4.57 5.8 0.40 0.00 0.00 1.0 7.2 6.4 8.1 8.6 8/74 CGS 33' 8/74 CGS (temp) 23' 8/74 HMS 50' August (1955-1970) HMS (hist) 50' 0.00 0.40 0.81 21.91 27.82 16.53 18.9 46.37 46.24 43.28 38.2 19.35 17.20 26.21 25.6 7.12 6.85 7.53 12.3 3.36 1.21 5.11 4.2 0.13 0.00 0.54 0.8 6.8 6.0 7.5 8.0 9/74 CGS 33' 9/73 CGS (temp) 23' 9/73 HMS 50' September (1955-1970) HMS (hist) 50' 0.00 0.00 2.64 27.78 26.67 20.42 23.6 38.06 42.08 36.25 36.8 22.50 22.50 28.33 23.8 8.75 7.50 8.75 10.9 1.39 1.25 3.19 4.1 0.42 0.00 0.42 0.8 6.5 6.2 7.1 7.5 (1) For some months, when, concurrent measurements are not available for all sites shown; previous year data is given. (2) HMS (hist) 50' calm values are included in the 1-3 mph range group.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-78Table 2.3-13 Percent Frequency of Occurrence of Wind Speed at the Hanford Reservation (1) (Continued) Month/Year/Site/Elevation Calm 1-3 4-7 8-12 13-18 19-24 25-Up Average Speed (mph) 10/74 CGS 33' 10/73 CGS (temp) 23' 10/73 HMS 50' October (1955-1970) RMS (hist) 50' 0.13 0.27 4.57 44.49 30.91 25.81 32.1 34.27 40.99 34.95 34.0 11.16 16.80 23.39 21.3 3.36 8.87 7.53 8.3 0.94 2.15 3.23 3.3 0.00 0.00 0.54 1.0 4.8 6.2 6.7 6.7 11/74 CGS 33' 11/73 CGS (temp) 23' 11/73 HMS 50' November (1955-1970) HMS (hist) 50' 0.00 0.28 5.42 34.72 17.92 19.86 39.7 39.58 37.08 33.89 30.1 16.11 21.53 26.67 18.9 5.97 7.78 6.81 7.5 1.53 2.36 5.28 2.7 0.00 0.00 2.08 1.1 5.8 7.1 7.5 6.2 12/74 CGS 33' 12/73 CGS (temp) 23' 12/73 HMS 50' December (1955-1970) HMS (hist) 50' 0.00 0.67 6.59 31.05 41.53 25.13 41.4 37.23 31.72 31.05 29.2 21.51 15.86 23.79 18.9 6.05 8.74 9.95 6.7 1.61 1.21 3.09 2.5 1.21 0.27 0.40 1.3 6.4 5.7 6.7 6.0 1/75 CGS 33' 1/74 CGS (temp) 23' 1/74 HMS 50' January (1955-1970) HMS (hist) 50' 0.00 2.02 4.70 29.44 29.97 21.10 38.8 36.83 24.46 26.48 30.2 19.76 15.46 21.24 19.5 5.38 16.40 13.31 7.6 2.02 7.80 7.66 2.7 0.67 3.90 5.51 1.2 6.4 8.7 9.3 6.4 2/75 CGS 33' 2/74 CGS (temp) 23' 2/74 HMS 50' February (1955-1970) HMS (hist) 50' 0.00 1.19 1.79 22.47 26.64 20.09 30.8 36.90 29.17 33.63 31.0 23.36 22.17 23.66 23.9 9.82 15.03 15.63 9.3 5.21 4.46 4.61 3.2 1.49 1.34 0.60 1.7 7.8 7.6 8.0 7.0 3/75 CGS 33' 3/74 CGS (temp) 23' 3/74 HMS 50' March (1955-1970) HMS (hist) 50' 0.00 1.08 0.40 13.04 28.90 16.94 20.0 31.85 31.32 33.33 32.6 27.02 18.68 25.81 26.1 14.11 12.77 13.04 13.5 4.44 3.36 7.66 5.4 1.08 3.36 2.82 2.4 8.7 7.8 9.1 8.4 April 1974 - March 1975 CGS 33' 1955-1970 HMS (hist) 50' 0.01 22.89 25.4 38.04 33.3 22.20 23.9 9.14 11.6 2.95 4.4 0.73 1.4 7.2 7.6 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-79Table 2.3-14 Diurnal Variation of 33-ft Elevation Dry Bulb Temperature (F) at CGS and Monthly Average Dry Bulb Temperature (F) at the Hanford Reservation Month/Year Hour April 1974 May 1974 June 1974 July 1974 August 1974 September 1974 October 1974 November1974 December 1974 January 1975 February1975 March 1975 Annual Average(April 1974 -March 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 46.7 46.1 44.9 44.4 43.3 43.6 45.3 49.2 51.8 54.2 56.2 57.9 59.3 60.5 60.9 60.9 60.3 58.8 56.1 53.6 51.8 50.3 48.9 47.7 51.0 49.8 48.3 46.9 45.8 47.0 50.9 54.4 56.8 59.0 61.3 63.1 64.9 66.3 67.5 67.7 67.4 66.2 63.9 60.3 57.7 56.0 54.2 52.7 63.7 62.1 60.3 58.1 57.5 59.6 63.8 68.0 72.7 75.3 78.0 80.5 82.3 83.8 85.1 84.6 85.1 84.1 81.9 77.8 73.7 70.7 68.0 66.0 66.5 64.5 62.2 60.8 59.7 61.0 65.3 69.3 73.0 75.1 77.3 79.4 81.3 83.2 84.7 85.2 85.2 84.7 82.7 78.7 75.5 73.0 70.8 68.9 66.8 64.6 63.0 61.2 60.0 59.6 63.6 68.8 72.9 76.4 79.1 81.6 84.0 86.2 87.5 88.4 88.4 87.1 83.7 79.6 75.7 73.6 71.0 69.0 58.2 57.1 56.3 55.3 54.1 53.0 53.9 58.9 64.8 68.6 72.0 75.2 77.8 79.8 81.0 81.6 81.2 78.4 73.6 69.4 67.1 64.5 62.3 60.4 45.6 44.7 43.3 42.6 41.3 40.8 40.4 43.4 48.3 52.7 56.4 59.5 62.0 63.7 64.8 65.1 63.7 60.0 56.4 53.5 51.3 49.4 48.2 46.4 40.3 40.1 39.6 39.5 39.0 38.7 38.3 38.3 39.9 41.6 43.8 45.4 46.7 47.4 47.6 46.9 45.0 43.5 42.7 42.1 41.6 41.0 40.2 40.0 35.3 35.3 35.1 35.0 34.9 34.1 33.8 33.8 34.4 35.8 37.9 39.6 41.0 41.7 41.5 40.5 38.8 37.7 36.8 36.8 36.8 36.1 35.2 35.1 30.9 30.8 30.4 30.6 30.1 30.0 29.4 29.5 30.3 31.7 33.0 34.9 35.7 36.5 37.2 36.7 35.2 33.9 32.9 32.1 31.5 31.1 31.0 30.8 30.6 30.5 30.1 30.2 30.1 29.8 29.6 29.3 31.3 33.9 35.6 37.6 38.6 39.3 39.7 39.5 38.7 36.8 35.3 34.4 33.8 32.8 32.4 31.6 37.5 36.6 35.9 35.0 34.9 34.7 35.1 37.4 40.6 42.9 45.2 46.9 48.6 49.4 50.3 50.8 50.0 47.9 44.9 42.7 41.2 40.1 39.2 38.1 47.9 46.9 45.9 45.1 44.3 44.4 45.8 48.4 51.2 54.3 56.2 58.4 60.1 61.6 62.4 62.3 61.7 60.4 57.7 55.2 53.3 51.7 50.2 49.0 Monthly Average Dry Bulb Temperature (F)* (Site, Elevation)

CGS 33' CGS 7' CGS (temp) 3' HMS 3' 1950-1970 HMS (hist) 3' 52.2 52.7 53.3 52.5 52.5 57.4 58.3 59.6 57.9 61.8 72.5 73.0 74.2 73.3 69.9 73.6 74.3 75.3 74.8 77.5 74.7 75.0 76.3 76.3 75.3 66.9 66.3 (65.0) 68.3 67.0 51.7 50.6 (51.2) 52.0 53.2 42.1 41.9 (39.7) 42.1 40.1 36.8 36.1 (37.8) 35.7 33.4 32.3 32.2 (29.0) 32.0 30.3 33.8 33.9 (40.7) 33.6 37.5 41.9 42.2 (45.4) 42.0 44.0 53.1 53.1 Not Computed 53.4 *For some months, when concurrent measurements are not available for all sites shown, former year data is given in parentheses.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-80Table 2.3-15 Diurnal Variation of 33-ft Elevation Wet Bulb Temperature (F) at CGS and Monthly Average Wet Bulb Temperature (F) at the Hanford Reservation Month/Year Hour April 1974 May 1974 June 1974 July 1974 August 1974 September1974 October 1974 November1974 December 1974 January 1975 February 1975 March 1975 Annual Average(April 1974 -March 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 41.9 41.5 40.9 40.7 40.2 40.5 41.9 44.2 45.5 46.6 47.1 47.8 48.2 48.6 48.7 48.6 48.5 48.0 46.8 45.8 44.8 43.8 43.1 42.5 44.4 43.8 43.3 42.6 41.9 42.7 44.9 46.1 47.5 48.1 49.1 49.7 50.3 50.7 51.0 50.9 50.8 50.4 49.7 48.5 47.4 46.6 45.8 45.1 52.1 51.6 50.9 50.1 50.0 51.2 53.3 54.9 56.8 57.7 58.8 59.6 60.0 60.3 60.7 60.1 60.5 60.3 59.6 58.4 56.5 54.9 54.1 53.1 54.7 54.1 53.1 52.6 52.3 53.4 55.4 56.9 57.9 58.5 59.0 59.7 60.2 60.4 60.9 61.1 61.0 60.8 60.1 59.0 58.0 57.2 56.2 55.6 54.9 54.1 53.5 52.8 52.5 52.3 54.5 56.8 58.2 59.7 60.6 61.2 61.7 62.2 62.4 62.6 62.6 62.0 60.9 59.6 58.0 57.3 56.6 55.8 49.1 48.6 48.0 47.6 47.0 46.4 47.1 49.7 52.6 54.2 55..4 56.5 57.4 57.9 58.2 58.3 58.0 57.0 55.4 53.6 52.4 51.4 50.5 49.7 40.7 40.1 39.3 38.9 38.0 37.8 37.5 39.5 42.7 44.9 46.7 48.0 49.1 49.7 50.2 50.3 49.8 48.4 46.4 44.8 43.4 42.4 41.8 41.1 38.0 38.0 37.6 37.6 37.3 37.1 36.8 36.9 38.2 39.3 40.8 41.6 42.3 42.6 42.8 42.4 41.4 40.5 40.0 39.6 39.0 38.5 37.8 37.7 33.5 33.6 33.5 33.4 33.2 32.7 32.4 32.2 32.6 34.0 35.4 36.4 37.3 37.6 37.6 36.9 35.8 35.1 34.4 34.4 34.4 34.1 33.5 33.5 29.0 29.0 28.7 28.9 28.5 28.4 27.9 27.8 28.4 29.6 30.6 31.8 32.3 32.8 33.2 32.9 31.9 30.9 30.4 29.7 29.4 29.0 29.0 28.8 28.9 28.7 28.5 28.4 28.3 28.0 27.8 27.6 29.5 31.2 32.1 33.2 33.9 34.2 34.5 34.4 34.0 32.9 32.0 31.4 31.1 30.5 30.3 29.6 34.0 33.4 32.9 32.3 32.2 32.1 32.4 34.3 36.1 37.1 38.3 39.0 39.5 40.0 40.4 40.6 40.1 39.2 37.8 36.8 35.9 35.2 34.6 34.0 41.8 41.4 40.9 40.6 40.2 40.3 41.0 42.3 43.8 45.3 46.1 47.0 47.7 48.2 48.4 48.3 48.0 47.2 46.2 45.2 44.3 43.5 42.8 42.3 Monthly Average Wet Bulb Temperature (F)* (Site, Elevation) CGS 33' CGS (temp) 3' HMS 3' 1950-1970 HMS (hist) 3' 44.7 45.9 43.9 42.8 47.2 49.8 46.5 49.1 56.0 60.0 54.5 54.5 57.4 61.0 56.3 57.9 58.0 62.6 57.0 57.3 52.6 (54.6) 52.0 52.6 43.8 (45.5) 42.0 45.4 39.3 (37.8) 38.0 36.4 34.5 (36.4) 33.0 31.2 30.0 (26.4) 30.0 27.9 30.9 (36.6) 31.0 33.6 36.2 (39.3) 36.0 37.3 44.3 Not Calculated 43.4 *For some months, when concurrent measurements are not available for all sites shown, former year data is given in parentheses.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-81Table 2.3-16 Diurnal Variation of 33 ft Elevation Dew Point Temperature (F) at CGS and Monthly Average Dew Point Temperature (F) at the Hanford Reservation Month/Year Hour April 1974 May 1974 June 1974 July 1974 August 1974 September1974 October 1974 November1974 December 1974 January 1975 February1975 March 1975 Annual Average(April 1974 -March 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 36.5 36.5 36.6 36.8 36.7 37.0 38.3 38.8 38.8 38.8 37.8 37.3 36.8 36.4 35.9 35.8 36.0 36.6 37.0 37.3 37.1 36.8 36.7 36.6 37.3 37.5 37.8 37.9 37.7 38.1 38.6 37.3 37.8 37.2 36.7 36.2 35.5 35.1 34.6 34.0 34.1 34.5 35.2 36.3 36.6 36.8 37.1 37.1 42.0 42.5 42.7 43.1 43.3 44.1 44.6 44.3 44.4 44.2 44.2 43.8 43.3 42.6 42.3 41.5 41.9 42.4 42.8 43.5 42.7 41.7 42.4 42.1 45.1 45.4 45.5 45.7 46.2 47.2 47.5 47.5 46.7 46.0 45.7 45.3 44.4 43.3 43.1 43.1 42.7 42.9 42.6 43.5 44.4 44.7 44.5 44.9 45.4 45.6 45.8 45.9 46.3 46.4 47.3 47.8 47.3 47.7 47.4 46.7 46.0 45.3 44.5 44.0 44.0 43.7 44.1 44.5 44.4 44.6 45.2 45.3 40.5 40.6 39.9 40.1 40.1 39.8 40.4 41.0 41.8 41.7 41.4 40.9 40.4 39.7 39.4 39.0 38.5 38.6 39.4 39.2 38.8 38.9 39.2 39.5 35.0 34.6 34.4 34.6 34.0 34.2 34.0 35.0 36.3 36.3 36.2 36.0 35.6 35.3 35.1 35.1 35.5 36.1 35.3 34.8 34.0 33.8 34.2 34.7 35.4 35.5 35.4 35.6 35.4 35.3 35.1 35.2 36.4 36.7 37.4 37.5 37.4 37.3 37.7 37.4 37.4 37.1 37.0 36.7 36.2 35.5 35.1 35.0 31.2 31.4 31.4 31.4 31.0 30.8 30.5 30.0 30.3 31.7 32.2 32.3 32.5 32.1 32.4 32.1 31.8 31.5 31.1 31.0 31.3 31.2 31.1 31.2 26.0 26.1 25.9 26.0 26.0 25.8 25.5 25.1 25.4 26.4 26.9 27.0 27.2 27.5 27.4 27.4 27.0 26.4 25.9 26.0 25.8 25.6 25.6 26.1 26.0 25.9 25.4 25.4 25.2 24.9 24.9 26.8 27.1 26.9 26.8 27.0 27.0 27.0 27.2 27.2 27.1 27.2 27.1 27.2 27.1 27.2 26.6 28.6 28.6 28.3 28.4 28.4 28.2 28.5 30.0 29.6 28.8 28.3 27.6 27.2 26.6 26.3 26.3 25.9 26.7 27.6 28.3 28.3 27.9 27.9 27.9 35.8 35.9 35.9 36.0 35.9 36.1 36.3 36.5 36.8 37.1 36.8 36.5 36.1 35.7 35.5 35.2 35.2 35.4 35.5 35.7 35.6 35.4 35.6 35.6 Monthly Average Dew Point Temperature (F) (Site/Elevation)

CGS 33' HMS 3' 1950-1970 HMS (hist) 3' 36.6 33.3 30.4 36.6 34.0 36.0 43.0 38.2 41.2 44.9 41.0 42.3 45.6 43.2 42.8 39.9 38.9 39.5 35.0 31.0 36.9 36.3 33.9 31.1 31.4 29.2 27.5 26.3 26.0 23.2 26.5 25.5 27.4 27.9 26.0 27.3 35.9 33.4 COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000LDCN-99-000 2.3-82Table 2.3-17 Frequency of Occurrence, Dry Bulb Temperature (F) Versus Time of Day from 4/74 through 3/75 for 33-ft Level TIME OF DAY -20

-15 -20

-15

-10 1 0

0 0 2 0

0 0 3 0

0 0 4 0

0 0 5 0

0 0 6 0

0 0 7 0

0 0 8 0

0 0 9 0

0 0 10 0 0

0 11 0 0

0 12 0 0

0 13 0 0

0 14 0 0

0 15 0 0

0 16 0 0

0 17 0 0

0 18 0 0

0 19 0 0

0 20 0 0

0 21 0 0

0 22 0 0

0 23 0 0

0 24 0 0

0 TOTAL0 0

0 5 0 5 10 15 -5 0 5 10 15 20 0 0

0 0

1 2 0 0

0 0

1 2 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 7 0 0

0 0

0 5 0 0

0 0

0 7 0 0

0 0

0 8 0 0

0 0

0 4 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 2 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 1 0 0

0 0

0 2 0 0

0 0

0 3 0 0

0 0

1 3 0 0

0 0

1 3 0 0

0 0

1 2 0 0

0 0

5 69 20 25 30 35 40 45 25 30 35 40 45 50 11 22 44 42 40 51 11 26 46 39 45 52 13 27 43 45 48 48 13 29 44 46 54 46 14 30 42 48 57 48 13 37 41 44 57 43 17 28 41 46 45 42 14 27 31 39 36 38 10 25 26 24 35 38 7 17 26 27 28 37 5 13 25 31 28 35 4 9 21 30 31 32 4 9 12 32 28 34 3 9 14 21 37 29 3 9 11 23 36 29 3 8 14 26 34 29 4 9 20 28 26 41 6 11 19 32 34 36 7 10 29 37 35 33 9 8 37 35 35 29 9 9 41 34 38 34 9 11 40 45 33 39 9 13 47 40 43 37 10 20 45 38 46 39 208 416 759 852 929 919 50 55 60 65 70 75 55 60 65 70 75 80 33 31 27 25 26 7 30 33 29 26 20 2 34 32 32 25 11 1 40 31 32 21 3 0 31 33 29 20 2 0 38 28 30 23 2 0 28 34 28 25 18 2 28 30 28 28 22 17 34 17 24 30 18 16 35 24 20 31 33 18 33 33 20 25 31 29 32 34 27 19 26 37 32 33 22 27 27 20 33 30 22 32 24 22 36 25 24 26 26 26 39 21 24 24 27 24 25 24 24 24 25 21 23 30 23 17 29 19 26 31 21 25 16 31 41 27 19 27 30 17 40 27 21 29 23 27 34 26 33 23 26 23 32 29 28 24 30 20 35 29 26 35 20 12 792 692 613 611 515 391 80 85 90 95 100 105 85 90 95 100 105 110 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 1 0

0 0

0 0 16 1 0

0 0

0 15 10 1 0

0 0 15 16 5 0

0 0 18 19 9 1

0 0 37 12 20 3 0

0 34 17 20 9 0

0 20 31 16 14 2 0 17 30 21 14 3 0 22 26 20 16 3 0 27 19 18 13 2 0 16 23 13 7 1

0 22 16 8 0

0 0 19 8 0

0 0

0 14 2 0

0 0

0 5 1

0 0

0 0 4 0

0 0

0 0 302 231 151 77 11 0 110 UNKNO TOTAL 0 3 365 0 3 365 0 3 365 0 3 365 0 4 365 0 4 365 0 4 365 0 18 365 0 47 365 0 33 365 0 18 365 0 14 365 0 12 365 0 8 365 0 7 365 0 6 365 0 6 365 0 6 365 0 3 365 0 3 365 0 3 365 0 3 365 0 3 365 0 3 365 0 217 8760 COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORTApril 2000LDCN-99-000 2.3-83Table 2.3-18 Frequency of Occurrence, Wet Bulb Temperature (F) Versus Time of Day from 4/74 through 3/75 for 33-ft Level TIME OF DAY -20

-15 -20

-15

-10 1 0

0 0 2 0

0 0 3 0

0 0 4 0

0 0 5 0

0 0 6 0

0 0 7 0

0 0 8 0

0 0 9 0

0 0 10 0 0

0 11 0 0

0 12 0 0

0 13 0 0

0 14 0 0

0 15 0 0

0 16 0 0

0 17 0 0

0 18 0 0

0 19 0 0

0 20 0 0

0 21 0 0

0 22 0 0

0 23 0 0

0 24 0 0

0 TOTAL 0 0

0 5 0 5 10 15 -5 0 5 10 15 20 0 0

0 0

2 1 0 0

0 0

2 2 0 0

0 0

2 4 0 0

0 0

1 7 0 0

0 0

1 9 0 0

0 0

1 8 0 0

0 0

1 9 0 0

0 0

2 8 0 0

0 0

1 5 0 0

0 0

1 3 0 0

0 0

1 3 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 3 0 0

0 0

0 2 0 0

0 0

0 2 0 0

0 0

0 2 0 0

0 0

1 1 0 0

0 0

1 1 0 0

0 0

1 3 0 0

0 0

1 4 0 0

0 0

2 2 0 0

0 0

2 2 0 0

0 0

2 1 0 0

0 0 25 88 20 25 30 35 40 45 25 30 35 40 45 50 14 35 44 54 73 43 15 33 51 51 73 44 18 35 46 58 65 52 14 42 47 57 65 54 14 41 50 60 61 51 16 43 45 67 56 47 18 41 42 60 53 51 15 34 37 51 55 47 9 30 32 44 52 39 8 24 33 41 51 49 8 14 39 45 52 51 6 10 43 39 50 54 6 7 33 50 45 52 6 7 26 49 53 50 6 7 24 51 51 52 5 10 28 50 51 48 7 11 31 50 48 47 8 14 35 52 44 49 10 18 41 48 48 52 9 18 48 46 50 55 8 23 47 48 62 43 10 26 55 44 56 52 9 35 47 56 57 44 12 39 44 49 65 52 251 597 968 1220 1336 1178 50 55 60 65 70 75 55 60 65 70 75 80 48 39 8 0

0 0 50 33 6 1

0 0 49 27 5 0

0 0 48 23 3 0

0 0 51 18 4 0

0 0 51 23 3 0

0 0 38 39 8 0

0 0 39 41 18 0 0

0 43 36 23 3 0

0 42 38 33 5 0

0 39 49 39 6 0

0 44 50 43 8 0

0 49 50 46 12 0 0 49 52 47 15 0 0 52 47 45 21 0 0 51 46 44 24 0 0 51 44 45 23 0 0 43 51 44 17 0 0 42 46 41 14 0 0 49 39 35 9 0

0 55 45 22 4 0

0 48 46 19 1 0

0 49 48 11 1 0

0 44 44 9 0

0 0 1124 974 601 164 0 0 80 UNKNO TOTAL 0 4 365 0 4 365 0 4 365 0 4 365 0 5 365 0 5 365 0 5 365 0 18 365 0 48 365 0 37 365 0 19 365 0 15 365 0 12 365 0 8 365 0 7 365 0 6 365 0 6 365 0 6 365 0 3 365 0 3 365 0 3 365 0 4 365 0 4 365 0 4 365 0 234 8760 COLUMBIA GENERATING STATION Amendment 54 FINAL SAFETY ANALYSIS REPORT April 2000LDCN-99-000 2.3-84Table 2.3-19 Frequency of Occurrence, Dew Point Temperature (F) Versus Time of Day from 4/74 through 3/75 for 33-ft Level TIME OF DAY -40

-35 -40

-35

-30 1 0

0 0 2 0

0 0 3 0

0 0 4 0

0 0 5 0

0 0 6 0

0 0 7 0

0 0 8 0

0 0 9 0

0 0 10 0 0

0 11 0 0

0 12 0 0

0 13 0 0

0 14 0 0

0 15 0 0

0 16 0 0

0 17 0 0

0 18 0 0

0 19 0 0

0 20 0 0

0 21 0 0

0 22 0 0

0 23 0 0

0 24 0 0

0 TOTAL 0 0

0-30

-25

-20

-15 5 -25

-20

-15 5 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 5 10 15 20 25 5 10 15 20 25 30 0 1

4 12 23 45 0 2

2 14 22 47 0 1

5 12 24 44 0 2

4 13 22 46 0 2

4 13 28 43 0 3

2 16 23 44 0 2

3 16 23 46 1 1

2 16 22 48 1 1

3 8 17 48 1 1

4 5 18 48 1 2

3 7 21 44 1 3

3 10 20 44 1 1

4 11 20 48 1 3

2 11 23 47 1 3

3 11 25 48 1 2

4 10 26 49 1 2

3 11 28 49 0 2

4 13 24 45 0 1

5 11 22 47 0 1

4 10 25 47 0 1

2 12 26 45 0 1

2 13 30 43 0 1

2 16 24 49 0 1

3 13 28 48 10 40 77 284 564 1112 30 35 40 45 50 55 35 40 45 50 55 60 74 86 67 38 7 3 70 77 77 38 8 3 74 74 73 42 9 2 67 77 73 44 10 2 65 81 65 48 6 4 68 77 66 46 11 2 60 78 64 42 21 4 48 81 59 44 20 4 47 70 56 47 16 4 45 74 65 48 15 5 53 87 56 54 15 4 56 89 66 47 9 3 59 90 67 42 8 3 69 80 73 40 6 2 66 78 78 38 6 1 66 90 73 30 7 1 66 92 69 29 6 3 74 86 71 24 9 3 76 86 74 27 10 3 73 88 70 30 10 3 76 91 68 28 6 4 76 91 62 33 8 1 70 88 65 35 7 3 73 78 67 40 6 4 1571 1991 1626 934 238 71 60 65 70 75 80 65 70 75 80 UNKNO 1 0

0 0

0 4 1 0

0 0

0 4 1 0

0 0

0 4 1 0

0 0

0 4 1 0

0 0

0 5 2 0

0 0

0 5 1 0

0 0

0 5 1 0

0 0

0 18 0 0

0 0

0 47 0 0

0 0

0 36 0 0

0 0

0 18 0 0

0 0

0 14 0 0

0 0

0 11 0 0

0 0

0 8 0 0

0 0

0 7 0 0

0 0

0 6 0 0

0 0

0 6 0 0

0 0

0 6 0 0

0 0

0 3 1 0

0 0

0 3 1 0

0 0

0 3 1 0

0 0

0 4 1 0

0 0

0 4 0 0

0 0

0 4 13 0 0

0 0 229 TOTAL 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 8760 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-85Table 2.3-20 Monthly Averages of Psychrometric Data Based on Period of Record (1950-1970) AVERAGES JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC YEAR DRY BULB WET BULB REL HUM.

DEWPOINT 30.3 27.9 76.0 23.2 37.5 33.6 69.7 27.4 44.0 37.3 55.0 27.3 52.5 42.8 46.4 30.4 61.8 49.1 41.8 36.0 69.9 54.5 39.4 41.2 77.5 57.9 31.5 42.3 75.3 57.3 34.9 42.8 67.0 52.6 39.9 39.5 53.2 45.4 57.7 36.9 40.1 36.4 72.6 31.1 33.4 31.2 80.8 27.5 53.5 43.8 53.8 33.8 MONTHLY AVERAGE EXTREMES DRY BULB HIGHEST YEAR LOWEST YEAR 43.0 1953 12.9 1950 44.0 1958 25.8 1956 48.7 1968 39.6 1955 56.2 1956 48.3 1955 68.7 1958 57.2 1962 75.5 1969 64.2 1953 82.8 1960 73.2 1963 82.5 1967 70.6 1964 72.0 1967 61.6 1970 59.1 1952 50.3 1968 45.8 1954 32.3 1955 38.8 1953 26.5 1964 56.3 1953 51.0 1955+

WET BULB HIGHEST YEAR LOWEST YEAR 39.3 1953 12.4 1950 40.7 1958 23.4 1956 40.8 1963 32.9 1955 45.1 1962 39.3 1955 54.6 1958 45.4 1959 58.6 1958 51.4 1954 61.2 1958 55.6 1954 61.1 1961 54.9 1964 56.5 1963 48.3 1970 47.7 1962 42.4 1970 42.3 1954 29.6 1955 35.8 1966 25.0 1964 46.5 1958 41.8 1955 REL HUM. HIGHEST YEAR LOWEST YEAR 89 1960 60 1963 87 1963 54 1967 66 1950 44 1965 64 1963 37 1966 *52 1962+

31 1966 54 1950 34 1960 40 1955 22 1959 44 1968 24 1967 55 1969 34 1952 74 1962 42 1952 80 1956 64 1963+ 90 1950 69 1968 58 1950+

49 1967 DEWPOINT HIGHEST YEAR LOWEST YEAR 34.4 1953 6.5 1950 36.7 1958 17.3 1956 34.0 1961 20.8 1965+ 37.1 1963 26.2 1955 43.8 1957 30.4 1964 47.5 1958 37.5 1954 46.6 1958 35.4 1959 46.9 1961 38.4 1955 45.4 1963 33.8 1970 43.5 1962 32.1 1970 38.3 1954 24.0 1959 34.3 1950 21.0 1951 37.7 1958 31.5 1955 +Also in Earlier Years *Although not included in these tables, an average of 63% was recorded in 1948 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-86Table 2.3-21 Diurnal Variation of Precipitation Intensity (Inches/Hour) at CGS and Monthly Total Precipitation (Inches) at the Hanford Reservation HOUR APRIL 1974 MAY 1974 JUNE 1974 JULY 1974 AUGUST 1974 SEPTEMBER 1974 OCTOBER1974 NOVEMBER1974 DECEMBER1974 JANUARY 1975 FEBRUARY1975 MARCH 1975 AVERAGE FOR HOUR (APRIL 1974 - MARCH 1975) 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 0.000 0.000 0.016 0.000 0.016 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.024 0.032 0.016 0.016 0.024 0.016 0.020 0.000 0.000 0.032 0.080 0.036 0.136 0.016 0.000 0.000 0.032 0.048 0.072 0.000 0.088 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.048 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.024 0.032 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.168 0.040 0.032 0.016 0.000 0.016 0.032 0.000 0.000 0.000 0.016 0.000 0.000 0.000 0.000 0.016 0.056 0.000 0.024 0.000 0.000 0.000 0.032 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.064 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.016 0.000 0.064 0.000 0.000 0.000 0.016 0.000 0.016 0.000 0.000 0.000 0.000 0.016 0.024 0.056 0.024 0.000 0.000 0.000 0.000 0.032 0.036 0.040 0.028 0.052 0.028 0.000 0.000 0.000 0.000 0.016 0.040 0.032 0.020 0.020 0.016 0.016 0.000 0.000 0.000 0.000 0.024 0.056 0.020 0.036 0.024 0.032 0.000 0.040 0.000 0.032 0.000 0.024 0.048 0.000 0.000 0.020 0.016 0.064 0.072 0.020 0.024 0.024 0.000 0.056 0.024 0.036 0.024 0.032 0.048 0.040 0.032 0.032 0.020 0.024 0.016 0.048 0.024 0.032 0.032 0.000 0.000 0.000 0.000 0.016 0.024 0.016 0.072 0.040 0.016 0.016 0.000 0.000 0.024 0.064 0.036 0.000 0.024 0.016 0.000 0.020 0.032 0.040 0.000 0.000 0.000 0.000 0.000 0.016 0.048 0.032 0.024 0.028 0.024 0.024 0.000 0.000 0.000 0.000 0.000 0.000 0.048 0.088 0.000 0.016 0.080 0.071 0.029 0.026 0.018 0.030 0.045 0.026 0.029 0.039 0.036 0.034 0.022 0.032 0.024 0.033 0.029 0.038 0.026 0.034 0.032 0.040 0.021 0.040 0.038 MONTHLY TOTAL PRECIPITATION (INCHES)

CGS HMS HMS (hist) 1946-1970 Mean Total 0.55 0.46 0.44 0.44 0.28 0.50 0.06 0.12 0.66 0.45 0.71 0.16 0.00 trace 0.21 0.06 0.01 0.30 0.10 0.21 0.61 0.56 0.71 0.80 0.67 0.97 0.81 0.93 1.43 0.97 0.67 0.98 0.58 0.52 0.33 0.38 4.92 6.21 6.53 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-87Table 2.3-22 Frequency of Occurrence, Precipitation (Inches/Hour) Versus Time of Day from 4/74 through 3/75 at CGS

Time of Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24TOTAL 016 6 5 7 4 5 5 8 5 6 4 5 5 6 6 8 7 9 8 7 8 4 3 8 10149 050 2 0 0 0 1 1 1 0 2 1 1 0 1 0 2 0 2 1 1 1 1 0 2 121 100 2 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 03 250 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 500 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-88 Table 2.3-22a Annual Frequency of Occurrence of Wind Direction and Wind Speed Versus Precipitation Intensity FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .016 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0 0 1-3 2 2

2 4-7 2 3

1 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 4 5

3 E ESE SE SSE S SSW 0 0

0 0

0 0 1 7

1 4

3 3 4 2

1 6

3 3 0 0

2 4

5 4 0 0

1 4

0 3 0 0

0 1

0 1 0 0

0 0

0 0 0 0

0 0

0 0 5 9

5 21 11 14 SW WSW W WNW NW NNW 0 0

0 0

0 0 1 1

0 0

5 2 3 2

3 5 10 10 4 1

2 7

5 2 1 0

0 0

1 0 0 1

0 0

0 0 0 0

1 0

0 0 0 0

0 0

0 0 9 5

6 12 21 14 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 2

0 0 36 1 1

0 0 60 0 0

0 0 36 0 0

0 0 10 0 0

0 0

3 0 0

0 0

1 0 0

0 1

1 1 3

0 1 149 FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .050 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0

0 1-3 1 1

0 4-7 1 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 2 1

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

1 3

0 2 0 0

0 2

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

1 5

0 2 SW WSW W WNW NW NNW 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 2 1 1 0 1

1 0 3 1 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 0

0 0 0 0 0 1

1 2 4 2 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

2 0 0

0 0

5 0 0

0 0 12 0 0

0 0

2 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0 21 FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .100 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0

0 1-3 0 0

0 4-7 0 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 0 0

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

1 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 1

0 0 SW WSW W WNW NW NNW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 1

0 0 0 0

0 0

0 1 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 1

0 1 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

0 0 0

0 0

1 0 0

0 0

1 0 0

0 0

1 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

3 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-89 Table 2.3-22a Annual Frequency of Occurrence of Wind Direction and Wind Speed Versus Precipitation Intensity (Continued) FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .250 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0

0 1-3 0 0

0 4-7 0 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 0 0

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 SW WSW W WNW NW NNW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 FREQUENCY OF OCCURRENCE, WIND DIRECTION VS SPEED FROM 4/74 THROUGH 3/75 AT WPPSS2 FOR 33 FOOT LEVEL RAIN INTENSITY GREATER THAN OR EQUAL .500 INCHES PER HOUR SPEED CLASS (MPH) NNE NE ENE CALM 0 0 0 1-3 0 0

0 4-7 0 0

0 8-12 0 0

0 13-18 0 0

0 19-24 0 0

0 25-UP 0 0

0 UNKNO 0 0

0 TOTAL 0 0

0 E ESE SE SSE S SSW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 SW WSW W WNW NW NNW 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 0 0

0 0

0 0 N VAR CALM UNKNO TOTAL 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 0 0

0 0

0 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-90Table 2.3-23 Statistic on Fog at the Hanford Meteorology Station (Based on 1945-1970 Data)* All Fog (viz 0-6 Miles) Dense Fog (viz 1/4 Mile or Less) No. of Days No. of Hours No. of Days No. of Hours Greatest No. of Hours of Persistence J

F M

A M

J J

A S

O N

D Avg 9 6

1

2 8 12 Greatest 19 20 6 1

3 1

1 1

1 9 14 20 Least 0 0

0 0

0 0

0 0

0 0

1 2 Avg 68.3 36.4 4.4 0.3 0.3

0.3 7.6 55.4 105.4 Greatest 193.4 206.2 20.6 2.8 2.7 0.5 0.7 1.0 5.5 63.6 148.0 193.8 Least 0 0

0 0

0 0

0 0

0 0

1.0 6.5 Avg 6 3

1

0 0

1 5

8 Greatest14 11 5 1

1 0

0 1

1 6 13 17 Least 0 0

0 0

0 0

0 0

0 0

0 2 Avg 20.4 12.7 1.8 0.1 0.1 0

0

0.1 3.1 21.1 42.0 Greatest52.4 86.7 7.8 1.8 1.6 0

0 1.0 3.2 35.2 71.4 119.8 Least 0 0

0 0

0 0

0 0

0 0

0 1.3 (9) AF 58.1 58.0 12.2 2.8 2.7 0.5 0.7 0.7 2.6 39.0 65.4 72.3 (10) DF 15.0 16.7 5.0 0

1.6 0

0 0.7 1.4 15.8 20.6 47.0 (1) (2) (3) (4) (5) (6) (7) (8) Y 33 57 22 278.4 462.5 147.7 24 42 2 101.4 201.5 24.3 72.3 47.0 # Less than 1/2 1. Greatest number of days in a season -- occurred in 1969-70 2. Least number of days in a season -- occurred in 1948-49

3. Greatest number of hours in a season -- occurred in 1964-65

4. Least number of hours in a season -- occurred in 1948-49

5. Greatest number of days in a season -- occurred in 1950-51

6. Least number of days in a season -- occurred in 1948-49

7. Greatest number of hours in a season -- occurred in 1962-63

8. Least number of hours in a season -- occurred in 1948-49

9. AF denotes all fog (viz 0-6 miles)

10. DF denotes dense fog (viz 1/4 mile or less). Records for persistence of dense fog did not begin until 1953.

• Summation for the year does not necessarily reflect the summation of individual months.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.3-91 Table 2.3-24 Percent Frequency Distribution of Wind Speeds During Hourly Observations of Fog at Pasco (1966-1970) and at HMS (1960-1970) Speed Class* Station Calm 1-3 4-7 8-12 12 Total HMS(1) 29 44 25 2 0 100 Pasco(2) 61 8 24 6 1 100

• Speed classes are in units of mph for HMS, and in units of knots for Pasco. (1) Statistics for HMS are only for hourly observations of fog restricting visibility to 1/2 mile or less.

(2) Statistics for Pasco are for all hourly observations of fog (visibility 0-6 miles).

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-92Table 2.3-25 Percent Frequency of Occurrence of Stability (T Distribution) at the Hanford Reservation (1) Month/Year/Site Very Unstable Less Than -2.5 Unstable -2.5 to -1.5 t Range (°F/200 ft) Neutral -1.5 to -0.5 Moderately Stable -0.5 to +3.5 Very Stable Greater Than 3.5 4/74 CGS 4/74 HMS APRIL 1955-1970 HMS (hist) 0.14 3.61 5.10 15.69 25.28 20.88 27.78 26.94 30.22 43.33 40.83 39.19 12.36 3.19 4.61 5/74 CGS 5/74 HMS MAY 1955-1970 HMS (hist) 0.27 6.18 8.33 23.39 33.20 22.56 30.51 26.34 30.18 35.89 32.39 34.71 8.06 1.88 4.22 6/74 CGS 6/74 HMS JUNE 1955-1970 HMS (hist) 1.25 7.36 8.60 35.42 33.33 26.25 17.36 24.72 30.75 30.42 31.39 31.45 5.42 3.19 2.95 7/74 CGS 7/74 HMS JULY 1955-1970 HMS (hist) 0.00 6.72 8.74 28.23 30.78 26.31 25.81 28.90 27.69 27.02 30.51 33.42 14.11 3.09 3.84 8/74 CGS 8/74 HMS AUGUST 1955-1970 HMS (hist) 0.00 8.20 7.33 28.09 32.12 23.73 20.83 18.28 26.55 23.79 33.74 37.65 25.54 7.66 4.74 9/74 CGS 9/74 HMS SEPTEMBER 1955-1970 HMS (hist) 0.00 6.94 5.05 21.67 25.69 19.90 20.83 17.64 25.11 21.25 33.06 40.89 35.14 16.67 9.05 10/74 CGS 10/74 HMS OCTOBER 1955-1970 HMS (hist) 0.00 3.36 2.23 14.38 20.16 11.82 18.15 17.74 27.03 25.81 41.26 48.87 38.98 17.47 10.06 11/74 CGS 11/74 HMS NOVEMBER 1955-1970 HMS (hist) 0.00 0.00 0.76 4.58 5.00 6.82 28.06 30.42 31.74 52.22 57.22 53.37 14.44 5.83 7.30 12/74 CGS 12/74 HMS DECEMBER 1955-1970 HMS (hist) 0.00 0.13 0.40 1.75 5.24 4.35 22.72 22.72 36.53 56.18 60.89 50.98 18.15 11.02 7.74 (1)t at CGS is computed from 33 to 245 foot levels; at HMS, t is computed from 50 to 250 foot level.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-93Table 2.3-25 Percent Frequency of Occurrence of Stability (T Distribution) at the Hanford Reservation (1) (Continued) Month/Year/Site Very Unstable Less Than -2.5 Unstable -2.5 to -1.5 t Range (°F/200 ft) Neutral -1.5 to -0.5 Moderately Stable -0.5 to +3.5 Very Stable Greater Than 3.5 1/75 CGS 1/74 HMS (1975 Not Available)

JANUARY 1955-1970 HMS (hist) 0.00 0.13 0.34 2.55 5.65 4.73 30.51 29.30 34.78 53.90 59.54 52.23 10.62 5.11 7.91 2/75 CGS 2/74 HMS (1975 Not Available)

FEBRUARY 1955-1970 HMS (hist) 0.00 0.30 1.51 8.78 14.43 9.29 30.51 26.93 28.24 49.40 51.19 52.05 10.57 7.14 8.90 3/75 CGS 3/74 HMS (1975 Not Available)

MARCH 1955-1970 HMS (hist) 0.13 1.48 3.49 20.03 19.09 15.84 17.34 26.34 28.22 42.07 47.04 45.25 11.96 6.05 6.61 April 1974 - March 1975 CGS 1955-1970 HMS (hist) 0.14 4.32 17.17 16.04 24.25 29.80 38.21 41.84 17.17 6.49 April 1975 -

March 1976 CGS 0.59 21.31 21.85 37.20 17.51 (1)t at CGS is computed from 33 to 245 foot levels; at HMS, t is computed from 50 to 250 foot level.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 19982.3-94Table 2.3-26 Frequency of Occurrence T (F/200 ft) Versus Time of Day from 4/74 through 3/75 at CGS between 245 and 33 ft Levels Time of Day 1 2 3 4 5 6789101112131415 161718192021222324TOTALLT-2.5 0 0 0 0 0 0000032212 110000000 12GE-2.5 LT-1.5 0 0 0 0 0 0 3 43 98 137 156 175 213 217 196 148 90 271000001504 GE-1.5 LT-0.5 17 16 16 16 18 37 97 137 134 150 168 158 123 123 145 168 181 167 111 52 33 21 18 18 2124GE-0.5 LT-3.5 216 202 193 197 187 188 177 131 76 40 20 16 14 14 14 42 85 156 203 236 235 242 238 225 3347GE-3.5 124 141 148 143 150 133 84 36 9 511111 028417191951021161504UNKNO 8 6 8 9 10 7418483317131297 667966776 269TOTAL 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 365 8760 Average for Hour 3.008 3.261 2.714 .243 -1.104 -1.432 -1.502 -1.240 -.155 1.656 2.228 2.6852.899 3.226 3.227 1.499 -.654 -1.303 -1.521 -1.441 -.835 .762 2.144 2.383 .883 COLUMBIA GENERATING STATION Amendment53 FINAL SAFETY ANALYSIS REPORTNovember 19982.3-95Table 2.3-27 Frequency of Occurrence, Sigma (°) Versus Time of Day from 4/74 through 3/75 at CGS for 33 ft Level Time of Day GE22.5 1 111 2 110 3 105 4 104 5 104 611279681179124101391114412152131521415315 137 1610917 6218 4419 5220 5121 7922 882310724 98TOTAL2550LT22.5 GE17.5 30 33 32 38 33 32342932353944333646 393220212836262741790 LT17.5 GE12.5 43 48 54 52 52 47544846587055686050 5950363439435147411205LT 12.5 GE7.5 104 91 87 74 94 9711211481797179838094 1071441511131121059698882354LT7.5 GE3.75 60 61 64 75 62 56583131181917132327 396592121112908668771365LT3.75 GE2.1 0 5 7 5 4 6100010000 1111138585687LT2.1 8 8 8 7 5 5020000000 00037524569 UNKNO 9 9 8 10 11 10102451362118161311 111111888899340TOTAL 365 365 365 365 365 365365365365365365365365365365 3653653653653653653653653658760 Average for Hour 22.406 23.575 22.42123.03127.39027.76828.29821.89514.19814.65618.66720.99723.638 22.506 22.794 21.73027.37828.12428.87427.136 17.01115.28517.97820.98522.384 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-96Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction PLANT NAME: COLUMBIA GENERATING STATION METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METER TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS A WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .029 .101 .231 .190 .168 .114 .051 .079 .003 .000 .000 .000 .96 .035 .123 .190 .145 .117 .088 .028 .057 .003 .006 .000 .000 .79 .027 .095 .161 .130 .060 .035 .016 .032 .006 .000 .000 .000 .56 .021 .073 .114 .035 .022 .006 .003 .000 .000 .000 .000 .000 .27 .024 .085 .095 .032 .016 .013 .000 .000 .000 .000 .000 .000 .26 .022 .079 .123 .095 .028 .013 .003 .000 .000 .000 .000 .000 .36 .025 .088 .247 .158 .139 .070 .019 .003 .000 .000 .000 .000 .75 .014 .051 .180 .247 .262 .114 .047 .022 .006 .003 .000 .000 .95 .024 .085 .224 .209 .180 .196 .180 .196 .063 .022 .000 .000 1.38 .017 .060 .155 .107 .107 .117 .079 .092 .016 .006 .003 .000 .76 .013 .044 .098 .073 .076 .073 .035 .066 .035 .003 .000 .000 .52 .016 .057 .063 .054 .038 .025 .013 .041 .025 .009 .000 .000 .34 .013 .047 .095 .028 .035 .025 .016 .028 .022 .009 .000 .000 .32 .020 .070 .098 .054 .016 .019 .019 .035 .019 .022 .000 .000 .37 .022 .079 .155 .085 .060 .013 .016 .019 .013 .009 .000 .000 .47 .024 .085 .269 .171 .085 .098 .054 .035 .000 .003 .003 .000 .83 .348 1.223 2.497 1.811 1.410 1.018 .578 .705 .212 .095 .006 .000 9.90 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS B WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .007 .022 .063 .085 .047 .035 .019 .013 .003 .000 .000 .000 .29 .008 .025 .041 .057 .057 .032 .006 .006 .000 .006 .000 .000 .24 .001 .003 .035 .047 .032 .025 .003 .006 .000 .000 .000 .000 .15 .005 .016 .013 .013 .006 .003 .003 .009 .000 .000 .000 .000 .07 .007 .022 .019 .009 .006 .000 .000 .000 .000 .000 .000 .000 .06 .005 .016 .035 .016 .022 .006 .000 .000 .000 .000 .000 .000 .10 .006 .019 .038 .063 .038 .009 .006 .009 .000 .000 .000 .000 .19 .006 .019 .025 .076 .085 .051 .019 .013 .003 .000 .000 .000 .30 .005 .016 .070 .095 .076 .092 .047 .066 .009 .000 .000 .000 .48 .005 .016 .057 .025 .047 .047 .041 .060 .025 .013 .000 .000 .34 .003 .009 .051 .032 .022 .032 .016 .051 .025 .025 .000 .000 .27 .003 .009 .028 .016 .019 .013 .000 .006 .013 .000 .000 .000 .11 .004 .013 .028 .016 .019 .019 .028 .032 .003 .013 .000 .000 .17 .003 .009 .025 .022 .022 .019 .022 .016 .006 .013 .000 .000 .16 .008 .025 .038 .028 .038 .016 .013 .006 .003 .000 .000 .000 .18 .012 .038 .063 .070 .032 .025 .009 .013 .000 .000 .000 .000 .26 .092 .278 .629 .670 .569 .424 .234 .307 .092 .070 .000 .000 3.36 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-97Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS C TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .007 .019 .076 .079 .054 .051 .022 .022 .000 .000 .000 .000 .33 .011 .032 .060 .057 .047 .035 .009 .006 .006 .000 .000 .000 .26 .009 .025 .035 .035 .009 .016 .009 .006 .000 .000 .000 .000 .14 .005 .016 .013 .028 .003 .000 .000 .000 .000 .000 .000 .000 .07 .003 .009 .019 .022 .006 .000 .000 .000 .000 .000 .000 .000 .06 .004 .013 .009 .003 .013 .006 .000 .000 .000 .000 .000 .000 .05 .005 .016 .025 .063 .035 .022 .003 .016 .000 .000 .000 .000 .19 .002 .006 .047 .098 .076 .057 .035 .016 .000 .000 .000 .000 .34 .007 .019 .044 .082 .092 .063 .063 .047 .019 .006 .000 .000 .44 .008 .022 .057 .044 .044 .047 .057 .063 .032 .019 .000 .000 .39 .008 .022 .028 .028 .044 .047 .022 .054 .041 .009 .000 .000 .30 .003 .009 .044 .019 .022 .035 .016 .028 .044 .003 .000 .000 .22 .003 .009 .022 .028 .025 .022 .022 .032 .013 .003 .000 .000 .18 .003 .009 .028 .038 .009 .022 .022 .016 .028 .025 .000 .000 .20 .003 .009 .051 .054 .022 .022 .013 .009 .022 .000 .000 .000 .21 .007 .019 .054 .079 .051 .035 .022 .028 .003 .003 .000 .000 .30 .088 .256 .613 .759 .553 .480 .316 .345 .209 .070 .000 .000 3.69 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS D WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .035 .142 .332 .420 .218 .193 .130 .032 .003 .003 .000 .000 1.51 .025 .101 .215 .231 .186 .101 .047 .038 .025 .003 .000 .000 .97 .020 .082 .168 .171 .126 .107 .051 .013 .019 .013 .006 .000 .78 .018 .073 .104 .079 .060 .019 .000 .006 .000 .000 .000 .000 .36 .012 .051 .117 .073 .057 .016 .000 .000 .000 .000 .000 .000 .33 .010 .041 .101 .092 .082 .022 .016 .003 .000 .000 .000 .000 .37 .021 .085 .205 .193 .218 .133 .051 .013 .003 .000 .000 .000 .92 .018 .073 .322 .401 .395 .303 .136 .120 .009 .000 .000 .000 1.78 .025 .101 .322 .338 .398 .326 .228 .335 .123 .041 .006 .000 2.24 .015 .060 .243 .212 .205 .281 .240 .370 .215 .120 .022 .000 1.98 .031 .126 .136 .168 .161 .142 .107 .202 .142 .101 .016 .000 1.33 .019 .079 .123 .149 .079 .054 .082 .155 .133 .035 .000 .000 .91 .027 .111 .158 .092 .101 .126 .092 .107 .057 .016 .006 .000 .89 .030 .123 .158 .202 .202 .149 .171 .326 .161 .057 .006 .000 1.59 .028 .114 .471 .468 .414 .310 .231 .161 .088 .051 .006 .000 2.34 .031 .126 .405 .455 .408 .265 .149 .155 .047 .009 .009 .000 2.06 .363 1.489 3.581 3.742 3.312 2.547 1.729 2.035 1.027 .449 .079 .000 20.35 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-98Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS E WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .037 .142 .370 .307 .161 .079 .035 .025 .009 .003 .000 .000 1.17 .029 .111 .291 .250 .104 .032 .013 .041 .041 .000 .000 .000 .91 .019 .073 .199 .171 .145 .047 .009 .019 .022 .003 .000 .000 .71 .021 .082 .095 .085 .025 .028 .016 .003 .000 .000 .000 .000 .36 .018 .070 .070 .060 .016 .000 .000 .003 .000 .000 .000 .000 .24 .013 .051 .098 .063 .079 .038 .006 .000 .000 .000 .000 .000 .35 .025 .095 .247 .288 .348 .247 .101 .070 .003 .000 .000 .000 1.42 .029 .111 .411 .544 .670 .525 .288 .224 .009 .000 .000 .000 2.81 .051 .196 .490 .484 .484 .553 .430 .424 .076 .025 .006 .000 3.22 .043 .168 .392 .288 .196 .250 .316 .518 .348 .133 .025 .000 2.68 .045 .174 .281 .228 .199 .164 .199 .224 .196 .082 .016 .000 1.81 .043 .164 .307 .218 .142 .107 .104 .120 .038 .019 .000 .000 1.26 .051 .196 .310 .256 .272 .136 .136 .130 .038 .019 .000 .000 1.54 .074 .284 .446 .480 .455 .509 .442 .477 .202 .063 .006 .000 3.44 .066 .253 .651 .762 .610 .487 .389 .354 .098 .032 .000 .000 3.70 .045 .174 .676 .540 .414 .234 .107 .180 .066 .013 .000 .000 2.45 .607 2.342 5.332 5.022 4.320 3.436 2.592 2.813 1.147 .392 .054 .000 28.06 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS F WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .075 .272 .531 .307 .041 .006 .009 .000 .000 .000 .000 .000 1.24 .055 .199 .446 .205 .025 .003 .000 .000 .000 .000 .000 .000 .93 .037 .136 .221 .126 .070 .009 .000 .000 .000 .000 .000 .000 .60 .016 .057 .095 .051 .032 .009 .000 .000 .000 .000 .000 .000 .26 .016 .057 .044 .025 .006 .000 .000 .000 .000 .000 .000 .000 .15 .014 .051 .076 .032 .013 .006 .000 .000 .000 .000 .000 .000 .19 .020 .073 .209 .174 .269 .111 .028 .013 .000 .000 .000 .000 .90 .035 .126 .512 .604 .582 .414 .092 .066 .006 .000 .000 .000 2.44 .055 .202 .629 .733 .578 .297 .130 .104 .009 .006 .000 .000 2.75 .041 .149 .455 .389 .288 .120 .107 .085 .047 .009 .000 .000 1.69 .049 .177 .303 .205 .117 .051 .032 .032 .003 .006 .000 .000 .97 .057 .209 .265 .183 .088 .051 .016 .016 .000 .003 .000 .000 .89 .065 .237 .322 .164 .142 .101 .051 .006 .003 .000 .000 .000 1.09 .070 .256 .442 .319 .326 .171 .088 .044 .000 .000 .000 .000 1.72 .083 .303 .733 .512 .442 .161 .063 .006 .000 .000 .000 .000 2.31 .072 .262 .670 .528 .177 .073 .013 .013 .000 .000 .000 .000 1.81 .759 2.765 5.954 4.558 3.195 1.583 .629 .386 .070 .025 .000 .000 19.92 COLUMBIA GENERATING STATION Amendment59 FINAL SAFETY ANALYSIS REPORTDecember 2007LDCN-05-009 2.3-99Table 2.3-28 Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS G WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 TOTAL .42 1.01 2.03 3.02 4.00 5.03 6.01 8.02 10.04 13.03 18.04 44.70 .113 .332 .860 .281 .025 .000 .000 .000 .000 .000 .000 .000 1.61 .111 .326 .787 .237 .025 .000 .000 .000 .000 .000 .000 .000 1.49 .068 .199 .335 .180 .060 .009 .000 .000 .000 .000 .000 .000 .85 .030 .088 .092 .044 .019 .006 .003 .000 .000 .000 .000 .000 .28 .020 .060 .019 .003 .003 .000 .000 .000 .000 .000 .000 .000 .11 .022 .063 .019 .000 .000 .000 .000 .000 .000 .000 .000 .000 .10 .027 .079 .139 .114 .028 .009 .000 .000 .000 .000 .000 .000 .40 .054 .158 .357 .493 .307 .136 .032 .006 .003 .000 .000 .000 1.55 .059 .174 .408 .496 .313 .085 .028 .009 .006 .000 .000 .000 1.58 .047 .139 .335 .155 .111 .025 .019 .003 .000 .003 .000 .000 .84 .067 .196 .237 .082 .047 .000 .000 .000 .000 .000 .003 .000 .63 .061 .180 .120 .051 .019 .013 .003 .000 .000 .000 .000 .000 .45 .067 .196 .171 .047 .041 .016 .000 .000 .000 .000 .000 .000 .54 .071 .209 .307 .139 .044 .016 .000 .000 .000 .000 .000 .000 .79 .094 .275 .667 .395 .221 .019 .006 .000 .000 .000 .000 .000 1.68 .134 .392 .796 .405 .101 .003 .000 .000 .000 .000 .000 .000 1.83 1.046 3.066 5.648 3.123 1.365 .338 .092 .019 .009 .003 .003 .000 14.71 WIND MEASURED AT 10.0 METERS WIND SPEED CORRECTED TO THE RELEASE HEIGHT OF 10.0 METERS.

OVERALL WIND DIRECTION FREQUENCY WIND DIRECTION: N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW FREQUENCY: 7.1 5.6 3.8 1.7 1.2 1.5 4.8 10.2 12.1 8.7 5.8 4.2 4.7 8.3 10.9 9.5 OVERALL WIND SPEED FREQUENCY AS MEASURED ON THE TOWER:

MAX. WIND SPEED (M/S): .425 1.006 2.034 3.018 4.001 5.029 6.013 8.024 10.036 13.031 18.038 44.704 WIND SPEED FREQUENCY: 3.30 11.42 24.25 19.68 14.73 9.83 6.17 6.61 2.77 1.10 .14 .00 BUILDING AND RELEASE CHARACTERISTICS:

RELEASE HEIGHT: 10.00 METERS MIXING VOLUME COEFFICIENT: 0.50 BUILDING CROSS-SECTIONAL AREA: 2861.00 SQUARE METERS THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-100Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction PLANT NAME: COLUMBIA GENERATING STATION METEOROLOGICAL INSTRUMENTATION DATA PERIOD: 1984-1989, AVERAGE HOURLY DATA WIND SENSORS HEIGHT: 10.0 METER TYPE OF RELEASE: GROUND LVL RLS DELTA-T HEIGHTS: 245FT, 33FT SOURCE OF DATA: ANNUAL MET DATA COLLECTION 1984-1989 COMMENTS: DATA PROCESSED UNDER-THE SUPPLY SYSTEM QA PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS A WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.002 0.188 0.460 0.095 0.029 0.000 0.000 0.77 0.002 0.102 0.319 0.079 0.061 0.000 0.000 0.56 0.002 0.072 0.140 0.052 0.014 0.000 0.000 0.28 0.000 0.016 0.025 0.002 0.000 0.000 0.000 0.04 0.002 0.038 0.057 0.005 0.000 0.000 0.000 0.10 0.000 0.063 0.125 0.005 0.002 0.000 0.000 0.19 0.000 0.084 0.226 0.041 0.005 0.000 0.000 0.36 0.005 0.138 0.573 0.168 0.034 0.000 0.000 0.92 0.005 0.131 0.613 0.389 0.186 0.000 0.000 1.32 0.000 0.115 0.312 0.231 0.294 0.009 0.002 0.96 0.005 0.100 0.235 0.138 0.213 0.032 0.000 0.72 0.002 0.127 0.211 0.109 0.125 0.000 0.000 0.57 0.000 0.118 0.136 0.054 0.054 0.007 0.000 0.37 0.002 0.129 0.181 0.081 0.104 0.000 0.000 0.50 0.005 0.197 0.299 0.111 0.075 0.000 0.000 0.69 0.005 0.231 0.410 0.086 0.016 0.002 0.000 0.75 0.036 1.850 4.322 1.646 1.211 0.050 0.002 9.12 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS B WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.000 0.038 0.111 0.018 0.016 0.000 0.000 0.18 0.000 0.045 0.061 0.016 0.000 0.000 0.000 0.12 0.000 0.014 0.029 0.007 0.002 0.000 0.000 0.05 0.000 0.007 0.009 0.000 0.000 0.000 0.000 0.02 0.000 0.007 0.007 0.002 0.000 0.000 0.000 0.02 0.002 0.020 0.041 0.005 0.000 0.000 0.000 0.07 0.000 0.027 0.111 0.014 0.002 0.000 0.000 0.15 0.000 0.061 0.172 0.043 0.007 0.000 0.000 0.28 0.000 0.041 0.190 0.070 0.045 0.000 0.000 0.35 0.002 0.050 0.111 0.104 0.072 0.002 0.000 0.34 0.000 0.018 0.063 0.041 0.043 0.000 0.000 0.17 0.002 0.036 0.066 0.045 0.063 0.009 0.000 0.22 0.000 0.054 0.057 0.016 0.020 0.000 0.000 0.15 0.000 0.038 0.059 0.048 0.072 0.005 0.000 0.22 0.002 0.059 0.095 0.016 0.018 0.000 0.000 0.19 0.000 0.043 0.136 0.038 0.011 0.000 0.000 0.23 0.009 0.559 1.318 0.482 0.374 0.016 0.000 2.76 COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-101Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS C TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.000 0.095 0.177 0.061 0.032 0.000 0.000 0.36 0.000 0.059 0.097 0.027 0.005 0.000 0.000 0.19 0.002 0.020 0.070 0.014 0.000 0.000 0.000 0.11 0.000 0.029 0.032 0.000 0.000 0.000 0.000 0.06 0.000 0.020 0.034 0.002 0.002 0.000 0.005 0.06 0.000 0.027 0.059 0.009 0.007 0.000 0.000 0.10 0.000 0.043 0.143 0.023 0.000 0.000 0.000 0.21 0.000 0.102 0.238 0.079 0.020 0.000 0.000 0.44 0.000 0.070 0.188 0.154 0.086 0.000 0.000 0.50 0.002 0.059 0.161 0.106 0.052 0.005 0.000 0.38 0.000 0.079 0.115 0.100 0.054 0.002 0.000 0.35 0.002 0.066 0.136 0.095 0.068 0.007 0.000 0.37 0.000 0.075 0.102 0.075 0.045 0.000 0.002 0.30 0.005 0.100 0.120 0.041 0.091 0.005 0.000 0.36 0.000 0.088 0.170 0.045 0.063 0.000 0.000 0.37 0.000 0.109 0.179 0.029 0.023 0.000 0.000 0.34 0.011 1.041 2.019 0.860 0.548 0.018 0.007 4.50 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS D WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.014 0.469 0.623 0.211 0.109 0.000 0.000 1.42 0.011 0.267 0.387 0.081 0.052 0.000 0.000 0.80 0.005 0.147 0.238 0.038 0.029 0.000 0.000 0.46 0.002 0.081 0.095 0.002 0.011 0.000 0.000 0.19 0.000 0.093 0.140 0.016 0.011 0.000 0.000 0.26 0.002 0.204 0.231 0.048 0.007 0.000 0.000 0.49 0.005 0.213 0.441 0.072 0.032 0.000 0.000 0.76 0.005 0.287 0.847 0.244 0.068 0.000 0.000 1.45 0.002 0.337 0.885 0.414 0.220 0.002 0.000 1.86 0.011 0.283 0.627 0.475 0.387 0.032 0.000 1.82 0.002 0.263 0.414 0.290 0.283 0.011 0.005 1.27 0.016 0.333 0.340 0.201 0.226 0.005 0.002 1.12 0.005 0.355 0.407 0.231 0.177 0.005 0.002 1.18 0.016 0.448 0.586 0.349 0.387 0.032 0.007 1.82 0.011 0.559 0.894 0.240 0.213 0.020 0.005 1.94 0.014 0.534 0.996 0.263 0.170 0.009 0.000 1.99 0.120 4.874 8.152 3.176 2.381 0.115 0.020 18.84 COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-102Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS E WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.016 0.808 0.754 0.125 0.043 0.000 0.000 1.75 0.009 0.521 0.552 0.070 0.050 0.000 0.000 1.20 0.014 0.328 0.494 0.027 0.005 0.000 0.000 0.87 0.014 0.134 0.158 0.034 0.000 0.000 0.000 0.34 0.000 0.154 0.168 0.011 0.002 0.000 0.000 0.34 0.020 0.285 0.412 0.018 0.000 0.000 0.000 0.74 0.011 0.421 0.840 0.127 0.054 0.000 0.000 1.45 0.020 0.521 1.720 0.392 0.170 0.000 0.000 2.82 0.011 0.738 1.684 0.632 0.396 0.009 0.000 3.47 0.020 0.700 1.252 0.580 0.552 0.059 0.002 3.16 0.036 0.616 0.912 0.369 0.292 0.016 0.000 2.24 0.009 0.718 0.810 0.274 0.177 0.002 0.011 2.00 0.014 0.786 0.998 0.441 0.235 0.011 0.000 2.49 0.054 1.035 1.648 0.706 0.480 0.016 0.000 3.94 0.034 1.184 1.813 0.496 0.303 0.007 0.000 3.84 0.043 1.050 1.410 0.310 0.152 0.000 0.000 2.97 0.326 9.997 15.627 4.611 2.911 0.120 0.014 33.61 JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS F WIND SPEED (M/S)

TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.016 0.752 0.441 0.000 0.000 0.000 0.000 1.21 0.011 0.552 0.274 0.005 0.000 0.000 0.000 0.84 0.005 0.278 0.285 0.009 0.002 0.000 0.000 0.58 0.014 0.131 0.104 0.009 0.000 0.000 0.000 0.26 0.005 0.100 0.070 0.005 0.000 0.000 0.000 0.18 0.009 0.190 0.152 0.005 0.000 0.000 0.000 0.36 0.007 0.333 0.573 0.066 0.036 0.000 0.000 1.01 0.009 0.550 1.288 0.240 0.079 0.005 0.000 2.17 0.018 0.629 1.320 0.242 0.079 0.000 0.000 2.29 0.011 0.557 0.643 0.179 0.052 0.005 0.005 1.45 0.027 0.537 0.430 0.070 0.020 0.002 0.000 1.09 0.020 0.494 0.432 0.034 0.023 0.000 0.000 1.00 0.029 0.552 0.405 0.088 0.018 0.000 0.000 1.09 0.034 0.772 0.815 0.195 0.050 0.000 0.000 1.87 0.014 1.050 1.148 0.113 0.045 0.000 0.018 2.39 0.023 1.021 0.747 0.025 0.000 0.000 0.014 1.83 0.251 8.498 9.128 1.284 0.405 0.011 0.036 19.61 COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-07-044 2.3-103Table 2.3-28A Joint Frequency Distribution of Wind Speed and Direction (Continued)

JOINT FREQUENCY DISTRIBUTION OF WIND SPEED AND DIRECTION ATMOSPHERIC STABILITY CLASS G WIND SPEED (M/S) TOWER RELEASE N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 TOTAL 0.27 1.34 3.13 5.36 8.05 10.73 11.18 0.016 0.790 0.312 0.007 0.002 0.000 0.032 1.16 0.005 0.686 0.292 0.002 0.009 0.000 0.032 1.03 0.007 0.303 0.240 0.029 0.005 0.000 0.032 0.62 0.005 0.174 0.084 0.005 0.000 0.000 0.023 0.29 0.005 0.091 0.023 0.000 0.000 0.000 0.000 0.12 0.011 0.111 0.059 0.007 0.000 0.000 0.000 0.19 0.014 0.213 0.272 0.011 0.000 0.000 0.000 0.51 0.007 0.385 0.869 0.075 0.014 0.000 0.000 1.35 0.009 0.392 0.645 0.050 0.011 0.011 0.000 1.12 0.014 0.310 0.310 0.014 0.007 0.005 0.000 0.66 0.016 0.267 0.174 0.011 0.000 0.000 0.000 0.47 0.014 0.287 0.104 0.005 0.002 0.000 0.000 0.41 0.007 0.299 0.115 0.005 0.000 0.000 0.000 0.43 0.009 0.473 0.267 0.020 0.005 0.000 0.000 0.77 0.020 0.654 0.453 0.018 0.000 0.000 0.000 1.15 0.027 0.822 0.450 0.000 0.000 0.000 0.007 1.31 0.183 6.257 4.670 0.258 0.054 0.016 0.125 11.56 WIND MEASURED AT 10.0 METERS WIND SPEED CORRECTED TO THE RELEASE HEIGHT OF 10.0 METERS. OVERALL WIND DIRECTION FREQUENCY WIND DIRECTION: N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW FREQUENCY: 6.9 4.7 3.0 1.2 1.1 2.1 4.5 9.4 10.9 8.8 6.3 5.7 6.0 9.5 10.6 9.4 OVERALL WIND SPEED FREQUENCY AS MEASURED ON THE TOWER:

MAX. WIND SPEED (M/S): 0.268 1.341 3.129 5.364 8.047 10.729 11.176 WIND SPEED FREQUENCY: 0.94 33.08 45.23 12.32 7.88 0.35 0.20 BUILDING AND RELEASE CHARACTERISTICS:

RELEASE HEIGHT: 10.00 METERS MIXING VOLUME COEFFICIENT: 0.50 BUILDING CROSS-SECTIONAL AREA: 2766.00 SQUARE METERS THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-104

TABLE 2.3-29 THROUGH TABLE 2.3-32 DELETED COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-105Table 2.3-33 Exclusion Area Boundary Accident /Q Desert Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1950. 1.68E-04 1.61E-04 1.13E-04 5.62E-05 2.88E-05 3.14E-05 7.22E-05 1.19E-04 1.30E-04 1.09E-04 1.20E-04 1.14E-04 1.25E-04 1.39E-04 1.59E-04 1.81E-04 1.08E-04 1.02E-04 7.01E-05 3.38E-05 1.80E-05 1.94E-05 4.41E-05 7.70E-05 8.49E-05 6.85E-05 7.40E-05 6.94E-05 7.65E-05 8.76E-05 1.04E-04 1.18E-04 8.69E-05 8.16E-05 5.51E-05 2.63E-05 1.42E-05 1.53E-05 3.45E-05 6.20E-05 6.86E-05 5.45E-05 5.81E-05 5.41E-05 6.00E-05 6.94E-05 8.44E-05 9.52E-05 5.39E-05 5.00E-05 3.27E-05 1.51E-05 8.52E-06 9.06E-06 2.02E-05 3.87E-05 4.32E-05 3.31E-05 3.44E-05 3.16E-05 3.53E-05 4.20E-05 5.34E-05 5.98E-05 2.71E-05 2.48E-05 1.55E-05 6.88E-06 4.09E-06 4.29E-06 9.39E-06 1.97E-05 2.23E-05 1.62E-05 1.62E-05 1.46E-05 1.65E-05 2.04E-05 2.77E-05 3.07E-05 1.17E-05 1.05E-05 6.20E-06 2.62E-06 1.67E-06 1.72E-06 3.67E-06 8.64E-06 9.87E-06 6.73E-06 6.46E-06 5.66E-06 6.50E-06 8.41E-06 1.24E-05 1.36E-05 38.6 389.5 22.0 10.4 7.6 7.5 10.0 20.3 23.5 17.9 23.8 22.7 25.1 27.9 34.5 43.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 1.81E-04 TOTAL HOURS AROUND SITE: 724.9 SRP 2.3.4 1950. 1.69E-04 1.12E-04 9.06E-05 5.76E-05 3.01E-05 1.36E-05 SITE LIMIT 1.69E-04 1.12E-04 9.06E-055.76E-05 3.01E-05 1.36E-05 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-106 Table 2.3-33a Exclusion Area Boundary /Q Values Desert Sigmas w/ Meander Direction From Site 0.5% Level(a) (10-4 sec/m3) 5% Level(b) (10-4 sec/m3) S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1.68 1.61 1.13 0.562 0.288 0.314 0.722 1.19 1.30 1.09 1.20 1.14 1.25 1.39 1.59 1.81 2.04 2.26 2.13 2.20 2.19 1.93 1.17 1.18 1.17 1.18 1.74 2.03 2.00 1.58 1.52 1.86 (a) Exceeded 0.5% of the total time. (b) Exceeded 5% of the time that wind blows into the individual sector.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-107Table 2.3-34 Exclusion Area Boundary Accident /Q P-G Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950.1950. 1.67E-041.59E-041.15E-045.48E-052.52E-052.85E-057.40E-051.30E-041.38E-041.08E-041.09E-041.01E-041.10E-041.24E-041.59E-041.77E-04 8.92E-058.36E-055.89E-052.81E-051.39E-051.54E-053.92E-057.05E-057.60E-055.86E-055.81E-055.32E-055.87E-056.83E-058.86E-059.68E-05 6.53E-056.06E-054.21E-052.01E-051.03E-051.13E-052.85E-055.20E-055.65E-054.31E-054.24E-053.87E-054.29E-055.07E-056.61E-057.16E-05 3.32E-053.01E-052.04E-059.75E-065.39E-065.80E-061.43E-052.68E-052.97E-052.22E-052.15E-051.94E-052.17E-052.65E-053.51E-053.72E-05 1.25E-051.10E-057.20E-063.45E-062.12E-062.22E-065.29E-061.04E-051.18E-058.56E-068.07E-067.19E-068.18E-061.05E-051.41E-051.45E-05 3.82E-063.23E-062.01E-069.65E-076.80E-076.87E-071.57E-063.24E-063.81E-062.67E-062.44E-062.14E-062.47E-063.37E-064.63E-064.59E-06 38.9385.621.08.66.16.39.222.825.517.219.918.920.723.235.243.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 1.77E-04 TOTAL HOURS AROUND SITE: 702.8 SRP 2.3.4 1950. 2.86E-04 1.45E-04 1.03E-04 4.91E-05 1.70E-05 4.63E-06 SITE LIMIT 1.65E-04 9.16E-05 6.82E-05 3.59E-05 1.43E-05 4.63E-06 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-108 Table 2.3-34a Exclusion Area Boundary /Q Values Pasquill-Gifford Sigmar w/ Meander and Building Wake Credit Direction From Site 0.5% Level(a) (10-4 sec/m3) 5% Level(b) (10-4 sec/m3) S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1.67 1.59 1.15 0.548 0.252 0.285 0.740 1.30 1.38 1.08 1.09 1.01 1.10 1.24 1.59 1.77 1.99 2.18 2.02 1.96 1.93 1.71 1.14 1.29 1.25 1.17 1.53 1.80 1.77 1.38 1.52 1.82 (a) Exceeded 0.5% of the total time. (b) Exceeded 5% of the time that wind blows into the individual sector.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-109Table 2.3-35 Low Population Zone Accident /Q Desert Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWNWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 8.35E-05 7.96E-05 5.52E-05 2.18E-05 7.98E-06 8.94E-06 2.94E-05 5.22E-05 5.78E-05 5.01E-05 5.49E-05 5.04E-05 5.66E-05 6.26E-05 7.62E-05 8.91E-05 4.58E-05 4.33E-05 2.92E-05 1.16E-05 4.64E-06 5.13E-06 1.57E-05 2.93E-05 3.26E-05 2.71E-05 2.92E-05 2.66E-05 2.99E-05 3.39E-05 4.27E-05 4.95E-05 3.39E-05 3.19E-05 2.12E-05 8.48E-06 3.54E-06 3.89E-06 1.15E-05 2.20E-05 2.45E-05 1.99E-05 2.12E-05 1.93E-05 2.17E-05 2.50E-05 3.20E-05 3.69E-05 1.76E-05 1.64E-05 1.06E-05 4.28E-06 1.97E-06 2.13E-06 5.81E-06 1.17E-05 1.31E-05 1.03E-05 1.07E-05 9.60E-06 1.09E-05 1.28E-05 1.70E-05 1.95E-05 6.92E-06 6.36E-06 3.94E-06 1.61E-06 8.46E-07 8.96E-07 2.19E-06 4.78E-06 5.38E-06 3.95E-06 3.98E-06 3.53E-06 4.02E-06 4.94E-06 6.91E-06 7.81E-06 2.20E-06 1.99E-06 1.17E-06 4.85E-07 3.02E-07 3.11E-07 6.61E-07 1.59E-06 1.80E-06 1.23E-06 1.19E-06 1.04E-06 1.19E-06 1.54E-06 2.29E-06 2.55E-06 39.1 364.8 22.2 9.8 7.0 7.2 9.1 18.0 21.1 16.7 22.7 21.6 23.7 25.3 33.4 43.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 8.91E-05 TOTAL HOURS AROUND SITE: 685.7 SRP 2.3.4 4827. 7.96E-05 4.51E-05 3.39E-05 1.83E-05 7.54E-06 2.55E-06 SITE LIMIT 7.96E-05 4.51E-05 3.39E-05 1.83E-05 7.54E-06 2.55E-06 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-110Table 2.3-36 Low Population Zone Accident /Q P-G Sigmas PLANT NAME: CGS METEOROLOGICAL INSTRUMENTATION DATA PERIOD: JFD 1996-1999 WIND SENSORS HEIGHT: 10.0 METERS TYPE OF RELEASE: GROUND LEVEL RELEASE DELTA-T HEIGHTS: 10 - 75 METERS SOURCE OF DATA: CGS ONSITE MET DATA TAKEN FROM FRAMATOME JFD FILES FOR 96-99 COMMENTS: input file: P96-99-F.inp output file: P96-99-F.out PROGRAM: PAVAN, 10/76, 8/79 REVISION, IMPLEMENTATION OF REGULATORY GUIDE 1.145, REVISION 1 RELATIVE CONCENTRATION (/Q) VALUES (SEC/CUBIC METER) VERSUS HOURS PER YEAR MAX AVERAGING TIME 0-2 HR /Q IS DOWNWIND SECTOR DISTANCE (METERS) 0-2 HOURS 0-8 HOURS 8-24 HOURS 1-4 DAYS 4-30 DAYS ANNUAL AVERAGE EXCEEDED IN SECTOR DOWNWIND SECTOR S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 4827. 7.65E-05 7.30E-05 5.16E-05 2.17E-05 8.35E-06 9.39E-06 3.16E-05 5.63E-05 6.01E-05 4.77E-05 4.98E-05 4.56E-05 5.08E-05 5.64E-05 7.21E-05 8.17E-05 3.43E-05 3.21E-05 2.22E-05 9.52E-06 4.05E-06 4.48E-06 1.42E-05 2.59E-05 2.81E-05 2.18E-05 2.23E-05 2.03E-05 2.28E-05 2.61E-05 3.38E-05 3.74E-05 2.30E-05 2.13E-05 1.46E-05 6.31E-06 2.83E-06 3.10E-06 9.49E-06 1.76E-05 1.92E-05 1.48E-05 1.49E-05 1.35E-05 1.52E-05 1.78E-05 2.31E-05 2.53E-05 9.64E-06 8.74E-06 5.85E-06 2.59E-06 1.29E-06 1.39E-06 3.97E-06 7.56E-06 8.42E-06 6.32E-06 6.22E-06 5.62E-06 6.37E-06 7.71E-06 1.02E-05 1.08E-05 2.77E-06 2.43E-06 1.57E-06 7.19E-07 4.19E-07 4.38E-07 1.14E-06 2.25E-06 2.58E-06 1.87E-06 1.78E-06 1.59E-06 1.82E-06 2.32E-06 3.12E-06 3.21E-06 6.01E-07 5.08E-07 3.16E-07 1.50E-07 1.06E-07 1.07E-07 2.46E-07 5.13E-07 6.05E-07 4.21E-07 3.84E-07 3.40E-07 3.94E-07 5.36E-07 7.35E-07 7.24E-07 38.9 379.7 20.9 9.2 6.5 6.7 9.1 21.4 24.0 16.8 21.1 20.1 22.1 23.6 34.6 43.7 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE MAX /Q 8.17E-05 TOTAL HOURS AROUND SITE: 698.5 SRP 2.3.4 4827. 1.15E-04 4.99E-05 3.28E-05 1.33E-05 3.61E-06 7.35E-07 SITE LIMIT 7.53E-05 3.50E-05 2.39E-05 1.04E-05 3.16E-06 7.35E-07 THE FIVE-PERCENT-FOR-THE-ENTIRE-SITE /Q IS LIMITING.

COLUMBIA GENERATING STATION Amendment 59 FINAL SAFETY ANALYSIS REPORT December 2007 LDCN-05-009 2.3-111Table 2.3-37 Control Room, Exclusion Area Boundary and Low Population Zone /Qs (S/m3) Control Room(1) LPZ(2) EAB(2) Filtered Unfiltered SGT Roofline Railway Bay doors SC Leakage RBW SC Leakage Turbine Building SGT Roofline Railway Bay doors SC Leakage RBW SC Leakage Turbine Building 0 - 2 hrs 1.43E-04 3.65E-04 1.99E-04 8.81E-04 6.95E-04 5.34E-04 8.69E-04 4.70E-03 4.95E-05 1.81E-04 2 - 8 hrs 1.05E-04 2.89E-04 1.44E-04 3.75E-04 3.36E-04 1.97E-04 4.40E-04 2.00E-03 4.95E-05 8 - 24 hrs 4.14E-05 1.18E-04 5.73E-05 1.93E-04 1.28E-04 8.41E-05 1.75E-04 1.03E-03 3.69E-05 1 - 4 days 3.52E-05 9.83 E-05 5.00E-05 1.50E-04 9.72E-05 7.26E-05 1.38E-04 8.01E-04 1.95E-05 4 - 30 days 3.03E-05 8.61E-05 4.18E-05 1.44E-04 7.69E-05 7.00E-05 1.10E-04 7.69E-04 7.81E-06 (1) Reference 2.3-37 (2) Reference 2.3-38 NOTE: EAB = Exclusion Area Boundary LPZ = Low Population Zone SGT = Standby Gas Treatment SC = Secondary Containment RBW = Reactor Building Wall COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-112Table 2.3-38a CGS Calculation, Terrain Features, Desert Sigmas CGS TURBINE AND RADWASTE BLDGS NO DECAY, UNDEPLETED CORRECTED USING STANDARD OPEN TERRAIN FACTORS ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 0.250 0.500 0.750 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 1.170E-04 8.738E-05 5.041E-05 2.672E-05 1.743E-05 3.424E-05 5.972E-05 1.094E-04 1.148E-04 9.052E-05 7.851E-05 7.545E-05 8.001E-05 1.238E-04 1.508E-04 1.535E-04 4.880E-05 3.691E-05 2.119E-05 1.129E-05 7.139E-06 1.390E-05 2.452E-05 4.499E-05 4.680E-05 3.669E-05 3.196E-05 3.053E-05 3.243E-05 5.040E-05 6.203E-05 6.378E-05 2.943E-05 2.243E-05 1.282E-05 6.851E-06 4.257E-06 8.233E-06 1.463E-05 2.691E-05 2.783E-05 2.171E-05 1.896E-05 1.805E-05 1.917E-05 2.986E-05 3.703E-05 3.835E-05 1.612E-05 1.234E-05 7.028E-06 3.769E-06 2.314E-06 4.450E-06 7.962E-06 1.468E-05 1.514E-05 1.174E-05 1.029E-05 9.773E-06 1.038E-05 1.617E-05 2.016E-05 2.097E-05 7.145E-06 5.502E-06 3.117E-06 1.679E-06 1.015E-06 1.936E-06 3.496E-06 6.471E-06 6.639E-06 5.115E-06 4.493E-06 4.260E-06 4.517E-06 7.040E-06 8.853E-06 9.262E-06 4.144E-06 3.204E-06 1.808E-06 9.761E-07 5.849E-07 1.109E-06 2.014E-06 3.738E-06 3.821E-06 2.930E-06 2.578E-06 2.442E-06 2.585E-06 4.029E-06 5.097E-06 5.358E-06 2.767E-06 2.146E-06 1.207E-06 6.527E-07 3.886E-07 7.331E-07 1.337E-06 2.487E-06 2.536E-06 1.937E-06 1.706E-06 1.615E-06 1.708E-06 2.662E-06 3.383E-06 3.569E-06 2.013E-06 1.565E-06 8.781E-07 4.753E-07 2.817E-07 5.293E-07 9.689E-07 1.805E-06 1.836E-06 1.399E-06 1.233E-06 1.167E-06 1.232E-06 1.920E-06 2.449E-06 2.593E-06 1.551E-06 1.208E-06 6.766E-07 3.666E-07 2.164E-07 4.053E-07 7.440E-07 1.388E-06 1.409E-06 1.071E-06 9.443E-07 8.935E-07 9.420E-07 1.469E-06 1.879E-06 1.995E-06 1.246E-06 9.718E-07 5.432E-07 2.945E-07 1.733E-07 3.237E-07 5.955E-07 1.112E-06 1.128E-06 8.551E-07 7.543E-07 7.136E-07 7.514E-07 1.172E-06 1.503E-06 1.600E-06 1.031E-06 8.058E-07 4.497E-07 2.439E-07 1.431E-07 2.667E-07 4.917E-07 9.193E-07 9.305E-07 7.045E-07 6.216E-07 5.881E-07 6.185E-07 9.644E-07 1.241E-06 1.323E-06 ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 5.000 7.500 10.000 15.000 20.000 25.000 30.000 35.000 40.000 45.000 50.000 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 8.745E-07 6.840E-07 3.812E-07 2.068E-07 1.211E-07 2.252E-07 4.159E-07 7.782E-07 7.867E-07 5.948E-07 5.248E-07 4.965E-07 5.217E-07 8.135E-07 1.049E-06 1.120E-06 4.911E-07 3.859E-07 2.140E-07 1.162E-07 6.750E-08 1.245E-07 2.313E-07 4.434E-07 4.368E-07 3.285E-07 2.900E-07 2.744E-07 2.872E-07 4.479E-07 5.821E-07 6.263E-07 3.377E-07 2.662E-07 1.471E-07 7.994E-08 4.618E-08 8.474E-08 1.580E-07 2.973E-07 2.979E-07 2.234E-07 1.972E-07 1.866E-07 1.947E-07 3.038E-07 3.970E-07 4.294E-07 2.095E-07 1.658E-07 9.121E-08 4.960E-08 2.846E-08 5.184E-08 9.714E-08 1.832E-07 1.827E-07 1.364E-07 1.204E-07 1.140E-07 1.184E-07 1.849E-07 2.435E-07 2.653E-07 1.494E-07 1.186E-07 6.504E-08 3.536E-08 2.021E-08 3.662E-08 6.883E-08 1.301E-07 1.292E-07 9.622E-08 8.490E-08 8.045E-08 8.330E-08 1.301E-07 1.722E-07 1.886E-07 1.150E-07 9.147E-08 5.005E-08 2.721E-08 1.550E-08 2.799E-08 5.272E-08 9.973E-08 9.881E-08 7.345E-08 6.478E-08 6.141E-08 6.343E-08 9.912E-08 1.317E-07 1.448E-07 9.290E-08 7.402E-08 4.042E-08 2.197E-08 1.249E-08 2.249E-08 4.242E-08 8.032E-08 7.940E-08 5.895E-08 5.196E-08 4.929E-08 5.080E-08 7.942E-08 1.059E-07 1.168E-07 7.760E-08 6.191E-08 3.376E-08 1.835E-08 1.041E-08 1.870E-08 3.532E-08 6.692E-08 6.604E-08 4.898E-08 4.316E-08 4.095E-08 4.214E-08 6.590E-08 8.809E-08 9.740E-08 6.641E-08 5.304E-08 2.889E-08 1.570E-08 8.897E-09 1.595E-08 3.014E-08 5.714E-08 5.630E-08 4.172E-08 3.675E-08 3.489E-08 3.584E-08 5.607E-08 7.511E-08 8.325E-08 5.789E-08 4.628E-08 2.518E-08 1.368E-08 7.744E-09 1.386E-08 2.621E-08 4.927E-08 4.892E-08 3.623E-08 3.189E-08 3.029E-08 3.108E-08 4.863E-08 6.527E-08 7.248E-08 5.121E-08 4.097E-08 2.227E-08 1.209E-08 6.841E-09 1.222E-08 2.314E-08 4.390E-08 4.314E-08 3.193E-08 2.810E-08 2.670E-08 2.736E-08 4.282E-08 5.757E-08 6.405E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-113Table 2.3-38b CGS Calculation, Terrain Features, Desert Sigmas

CGS TURBINE AND RADWASTE BLDGS NO DECAY, UNDEPLETED CHI/Q (SEC/METER CUBED) FOR EACH SEGMENT SEGMENT BOUNDARIES IN MILES FROM THE SITE DIRECTION FROM SITE .5-1 1-2 2-3 3-4 4-5 5-10 10-20 20-30 30-40 40-50 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 2.782E-05 2.117E-05 1.211E-05 6.468E-06 4.034E-06 7.812E-06 1.386E-05 2.549E-05 2.640E-05 2.061E-05 1.800E-05 1.715E-05 1.821E-05 2.834E-05 3.509E-05 3.628E-05 7.806E-06 6.000E-06 3.404E-06 1.831E-06 1.113E-06 2.127E-06 3.830E-06 7.081E-06 7.275E-06 5.617E-06 4.929E-06 4.677E-06 4.961E-06 7.730E-06 9.967E-06 1.013E-05 2.832E-06 2.195E-06 1.236E-06 6.680E-07 3.982E-07 7.518E-07 1.370E-06 2.548E-06 2.599E-06 1.986E-06 1.749E-06 1.656E-06 1.751E-06 2.730E-06 3.466E-06 3.656E-06 1.567E-06 1.220E-06 6.834E-07 3.702E-07 2.186E-07 4.096E-07 7.517E-07 1.402E-06 1.424E-06 1.082E-06 9.543E-07 9.030E-07 9.521E-07 1.484E-06 1.899E-06 2.015E-06 1.037E-06 8.099E-07 4.521E-07 2.451E-07 1.439E-07 2.682E-07 4.944E-07 9.242E-07 9.356E-07 7.085E-07 6.251E-07 5.914E-07 6.221E-07 9.699E-07 1.247E-06 1.330E-06 5.081E-07 3.989E-07 2.214E-07 1.202E-07 6.994E-08 1.292E-07 2.397E-07 4.498E-07 4.528E-07 3.410E-07 3.009E-07 2.848E-07 2.982E-07 4.651E-07 6.035E-07 6.485E-07 2.113E-07 1.671E-07 9.199E-08 5.001E-08 2.873E-08 5.239E-08 9.809E-08 1.849E-07 1.845E-07 1.379E-07 1.217E-07 1.152E-07 1.198E-07 1.870E-07 2.459E-07 2.677E-07 1.153E-07 9.172E-08 5.019E-08 2.729E-08 1.555E-08 2.809E-08 5.290E-08 1.001E-07 9.915E-08 7.372E-08 6.502E-08 6.164E-08 6.368E-08 9.951E-08 1.322E-07 1.453E-07 7.771E-08 6.199E-08 3.381E-08 1.837E-08 1.043E-08 1.873E-08 3.538E-08 6.703E-08 6.615E-08 4.906E-08 4.323E-08 4.103E-08 4.221E-08 6.602E-08 8.823E-08 9.755E-08 5.794E-08 4.631E-08 2.520E-08 1.369E-08 7.751E-09 1.387E-08 2.624E-08 4.976E-08 4.897E-08 3.626E-08 3.193E-08 3.032E-08 3.111E-08 4.868E-08 6.534E-08 7.255E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-114Table 2.3-38c CGS Calculation, Terrain Features, Desert Sigmas CGS TURBINE AND RADWASTE BLDGS - SPECIFIC POINTS OF INTEREST RELEASE ID TYPE OF LOCATION DIRECTION FROM SITE DISTANCE X/Q X/Q X/Q D/Q (MILES) (METERS) (SEC/CUB.METER) NO DECAY UNDEPLETED (SEC/CUB.METER) 2.260 DAY DECAY UNDEPLETED (SEC/CUB.METER) 8.000 DAY DECAY DEPLETED (PER SQ.METER) A A A

A A

A A

A A

A A

A A

A A

A A

A A

A A

A A

A A A A A

A A

A A

A A

A A

A A

A A PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

EAB (1950 M) EAB (1950 M) EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M) SE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE SE SE ESE ENE NNE ESE SE SE NE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 6.40 3.90 4.00 4.10 4.20 4.30 4.40 4.50 3.00 3.10 3.21 3.30 3.40 3.50 3.60 15.00 4.80 4.20 4.10 4.30 0.10 9.59 8.29 4.30 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 10298. 6275.

6436.

6597.

6758.

6919.

7080.

7241.

4827.

4988.

5159.

5310.

5471.

5632.

5792. 24135. 7723.

6758.

6597.

6918. 160. 15437.

13346. 6919.

1950. 1950. 1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950. 7.2E-07 1.2E-06 1.2E-06 1.1E-06 1.1E-06 1.0E-06 1.0E-06 9.6E-07 1.9E-06 1.8E-06 1.7E-06 1.6E-06 1.5E-06 1.5E-06 1.4E-06 2.4E-07 1.1E-06 1.1E-06 6.9E-07 7.6E-07 4.1E-04 4.2E-07 5.1E-07 6.7E-07 1.1E-05 8.4E-06 4.8E-06 2.6E-06 1.6E-06 3.0E-06 5.4E-06 9.9E-06 1.0E-05 7.9E-06 6.9E-06 6.6E-06 7.0E-06 1.1E-05 1.4E-05 1.4E-05 6.8E-07 1.2E-06 1.1E-06 1.1E-06 1.0E-06 1.0E-06 9.6E-07 9.2E-07 1.9E-06 1.8E-06 1.7E-06 1.6E-06 1.5E-06 1.4E-06 1.4E-06 2.1E-07 1.1E-06 1.0E-06 6.5E-07 7.3E-07 4.1E-04 3.9E-07 4.7E-07 6.3E-07 1.1E-05 8.3E-06 4.7E-06 2.5E-06 1.5E-06 2.9E-06 5.3E-06 9.8E-06 1.0E-05 7.8E-06 6.8E-06 6.5E-06 6.9E-06 1.1E-05 1.3E-05 1.4E-05 5.1E-07 9.3E-07 8.9E-07 8.5E-07 8.1E-07 7.8E-07 7.5E-07 7.2E-07 1.5E-06 1.4E-06 1.3E-06 1.3E-06 1.2E-06 1.1E-06 1.1E-06 1.5E-07 8.3E-07 8.1E-07 5.2E-07 5.7E-07 4.0E-04 2.8E-07 3.5E-07 5.0E-07 9.4E-06 7.2E-06 4.1E-06 2.2E-06 1.3E-06 2.6E-06 4.6E-06 8.5E-06 8.8E-06 6.8E-06 5.9E-06 5.6E-06 6.0E-06 9.3E-06 1.2E-05 1.2E-05 2.6E-10 7.0E-10 6.6E-10 6.3E-10 6.0E-10 5.7E-10 5.4E-10 5.1E-10 1.3E-09 1.2E-09 1.1E-09 1.0E-09 9.6E-10 9.0E-10 8.4E-10 6.0E-11 4.9E-10 6.0E-10 3.7E-10 5.1E-10 8.4E-07 1.3E-10 1.7E-10 3.7E-10 7.9E-09 5.5E-09 3.5E-09 1.4E-09 1.3E-09 2.5E-09 5.2E-09 1.1E-08 1.3E-08 1.0E-08 7.3E-09 6.7E-09 7.0E-09 1.1E-08 1.2E-08 1.1E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-115Table 2.3-38d CGS Calculation, Terrain Features, Desert Sigmas CGS REACTOR BLDG NO DECAY, UNDEPLETED CORRECTED USING STANDARD OPEN TERRAIN FACTORS ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 0.250 0.500 0.750 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 3.983E-07 3.015E-07 2.241E-07 9.654E-08 3.448E-08 7.411E-08 2.513E-07 7.930E-07 1.124E-06 1.049E-06 6.008E-07 4.892E-07 5.015E-07 9.120E-07 6.666E-07 4.473E-07 5.147E-07 3.460E-07 2.226E-07 7.983E-08 7.360E-08 1.508E-07 3.020E-07 7.233E-07 8.905E-07 7.337E-07 4.702E-07 5.305E-07 5.031E-07 7.571E-07 6.348E-07 5.728E-07 4.459E-07 2.917E-07 1.853E-07 7.694E-08 7.682E-08 1.476E-07 2.641E-07 5.856E-07 6.762E-07 5.603E-07 3.787E-07 4.710E-07 4.747E-07 6.975E-07 5.775E-07 5.291E-07 2.855E-07 1.836E-07 1.175E-07 5.258E-08 5.380E-08 1.017E-07 1.670E-07 3.550E-07 4.031E-07 3.353E-07 2.340E-07 3.229E-07 3.390E-07 4.987E-07 3.846E-07 3.498E-07 1.417E-07 8.972E-08 5.986E-08 2.801E-08 2.883E-08 5.532E-08 8.155E-08 1.649E-07 1.877E-07 1.577E-07 1.123E-07 2.809E-07 3.184E-07 4.778E-07 2.045E-07 1.780E-07 8.546E-08 5.399E-08 3.986E-08 1.857E-08 1.888E-08 3.697E-08 4.940E-08 9.701E-08 1.113E-07 9.422E-08 6.758E-08 3.180E-07 3.702E-07 5.635E-07 1.394E-07 1.089E-07 6.007E-08 3.809E-08 3.227E-08 1.473E-08 1.476E-08 2.952E-08 3.530E-08 6.783E-08 7.839E-08 6.677E-08 4.829E-08 3.667E-07 4.232E-07 6.623E-07 1.150E-07 7.782E-08 4.723E-08 3.012E-08 2.901E-08 1.300E-08 1.283E-08 2.619E-08 2.826E-08 5.335E-08 6.206E-08 5.308E-08 3.883E-08 5.692E-07 6.426E-07 1.026E-06 1.046E-07 6.216E-08 3.955E-08 2.537E-08 2.518E-08 1.120E-08 1.088E-08 2.256E-08 2.409E-08 4.477E-08 5.232E-08 4.498E-08 4.067E-08 1.128E-06 1.325E-06 1.950E-06 2.207E-07 5.287E-08 3.450E-08 2.223E-08 2.229E-08 9.892E-09 9.460E-09 1.990E-08 2.133E-08 3.913E-08 4.585E-08 3.965E-08 4.490E-08 1.019E-06 1.054E-06 1.650E-06 7.638E-07 4.674E-08 3.085E-08 1.996E-08 2.000E-08 8.868E-09 8.362E-09 1.781E-08 1.931E-08 4.183E-08 4.113E-08 4.297E-08 8.482E-08 8.387E-07 8.662E-07 1.356E-06 6.314E-07 4.227E-08 ANNUAL AVERAGE CHI/Q (SEC/METER CUBED) DISTANCE IN MILES FROM THE SITE SECTOR 5.000 7.500 10.000 15.000 20.000 25.000 30.000 35.000 40.000 45.000 50.000 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 2.814E-08 1.825E-08 1.814E-08 8.058E-09 7.499E-09 1.613E-08 1.778E-08 4.509E-08 3.754E-08 4.676E-08 2.656E-07 7.075E-07 7.296E-07 1.143E-06 5.345E-07 3.896E-08 2.023E-08 1.646E-08 1.472E-08 6.624E-09 4.948E-09 1.203E-08 1.734E-08 2.990E-08 4.858E-08 4.163E-07 4.104E-07 3.901E-07 4.000E-07 6.275E-07 2.974E-07 3.642E-08 1.577E-08 1.027E-08 6.195E-08 2.853E-08 3.627E-09 1.269E-08 1.283E-08 2.199E-08 4.276E-07 3.178E-07 2.789E-07 2.653E-07 2.710E-07 1.652E-07 2.034E-07 2.261E-08 3.200E-07 2.576E-07 1.393E-07 7.526E-08 4.242E-08 7.524E-08 1.423E-07 2.697E-07 2.625E-07 1.945E-07 1.705E-07 1.623E-07 1.650E-07 2.594E-07 3.525E-07 3.975E-07 2.287E-07 1.846E-07 9.960E-08 5.376E-08 3.020E-08 5.333E-08 1.011E-07 1.919E-07 1.860E-07 1.376E-07 1.205E-07 1.148E-07 1.163E-07 1.830E-07 2.499E-07 2.834E-07 1.764E-07 1.427E-07 7.682E-08 4.145E-08 2.323E-08 4.089E-08 7.760E-08 1.474E-07 1.425E-07 1.053E-07 9.214E-08 8.786E-08 8.872E-08 1.398E-07 1.916E-07 2.181E-07 1.428E-07 1.156E-07 6.218E-08 3.353E-08 1.876E-08 3.294E-08 6.258E-08 1.190E-07 1.148E-07 8.473E-08 7.408E-08 7.067E-08 7.121E-08 1.123E-07 1.544E-07 1.762E-07 1.195E-07 9.686E-08 5.202E-08 2.804E-08 1.567E-08 2.746E-08 5.221E-08 9.930E-08 9.564E-08 7.055E-08 6.164E-08 5.884E-08 5.918E-08 9.334E-08 1.287E-07 1.473E-07 1.024E-07 8.309E-08 4.458E-08 2.402E-08 1.341E-08 2.346E-08 4.463E-08 8.493E-08 8.168E-08 6.022E-08 5.259E-08 5.021E-08 5.043E-08 7.958E-08 1.099E-07 1.261E-07 8.938E-08 7.259E-08 3.891E-08 2.096E-08 1.169E-08 2.042E-08 3.888E-08 7.401E-08 7.108E-08 5.238E-08 4.572E-08 4.367E-08 4.380E-08 6.915E-08 9.568E-08 1.099E-07 7.915E-08 6.433E-08 3.446E-08 1.856E-08 1.034E-08 1.805E-08 3.437E-08 6.544E-08 6.278E-08 4.625E-08 4.035E-08 3.855E-08 3.862E-08 6.099E-08 8.452E-08 9.728E-08 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-116Table 2.3-38e CGS Calculation, Terrain Features, Desert Sigmas CGS REACTOR BLDG NO DECAY, UNDEPLETED CHI/Q (SEC/METER CUBED) FOR EACH SEGMENT SEGMENT BOUNDARIES IN MILES FROM THE SITE DIRECTION FROM SITE .5-1 1-2 2-3 3-4 4-5 5-10 10-20 20-30 30-40 40-50 S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 3.899E-07 2.557E-07 1.635E-07 6.676E-08 6.588E-08 1.279E-07 2.294E-07 5.137E-07 6.024E-07 4.988E-07 3.347E-07 4.184E-07 4.207E-07 6.224E-07 5.045E-07 4.591E-07 1.486E-07 9.471E-08 6.378E-08 2.927E-08 2.996E-08 5.746E-08 8.625E-08 1.770E-07 2.016E-07 1.690E-07 1.195E-07 3.067E-07 3.460E-07 5.205E-07 2.156E-07 1.855E-07 6.171E-08 3.914E-08 3.299E-08 1.506E-08 1.509E-08 3.018E-08 3.624E-08 6.982E-08 8.063E-08 6.861E-08 4.965E-08 4.347E-07 4.968E-07 7.813E-07 1.174E-07 7.985E-08 3.982E-08 2.553E-08 2.517E-08 1.122E-08 1.090E-08 2.258E-08 2.423E-08 4.507E-08 5.264E-08 4.526E-08 4.175E-08 9.267E-07 1.027E-06 1.572E-06 3.944E-07 5.319E-08 3.093E-08 2.000E-08 1.999E-08 8.872E-09 8.368E-09 1.781E-08 1.934E-08 4.224E-08 4.120E-08 4.339E-08 1.400E-07 8.436E-07 8.714E-07 1.364E-06 6.347E-07 4.237E-08 2.000E-08 1.411E-08 3.647E-08 1.668E-08 4.928E-09 1.324E-08 1.543E-08 2.976E-08 2.146E-07 2.904E-07 3.198E-07 4.052E-07 4.159E-07 5.365E-07 3.083E-07 3.085E-08 2.118E-07 1.702E-07 1.045E-07 5.532E-08 2.837E-08 5.160E-08 9.519E-08 1.801E-07 2.652E-07 1.966E-07 1.723E-07 1.641E-07 1.669E-07 2.045E-07 2.738E-07 2.635E-07 1.769E-07 1.431E-07 7.704E-08 4.156E-08 2.330E-08 4.103E-08 7.785E-08 1.479E-07 1.430E-07 1.057E-07 9.247E-08 8.817E-08 8.906E-08 1.403E-07 1.923E-07 2.188E-07 1.196E-07 9.698E-08 5.209E-08 2.808E-08 1.569E-08 2.750E-08 5.228E-08 9.945E-08 9.579E-08 7.066E-08 6.174E-08 5.893E-08 5.928E-08 9.350E-08 1.289E-07 1.475E-07 8.944E-08 7.264E-08 3.894E-08 2.098E-08 1.170E-08 2.044E-08 3.891E-08 7.407E-08 7.115E-08 5.243E-08 4.576E-08 4.371E-08 4.385E-08 6.922E-08 9.576E-08 1.100E-07

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-117Table 2.3-38f CGS Calculation, Terrain Features, Desert Sigmas CGS REACTOR BLDG, SPECIFIC POINTS OF INTEREST RELEASE ID TYPE OF LOCATION DIRECTION FROM SITE DISTANCE X/Q X/Q X/Q D/Q (MILES) (METERS) (SEC/CUB.METER) NO DECAY UNDEPLETED (SEC/CUB.METER) 2.260 DAY DECAY UNDEPLETED (SEC/CUB.METER) 8.000 DAY DECAY DEPLETED (PER SQ.METER) B B B

B B

B B

B B

B B

B B

B B

B B

B B

B B

B B

B B B B B

B B

B B

B B

B B

B B

B B PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE PROTECTED ARE LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

LPZ (4828)

EAB (1950 M) EAB (1950 M) EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M)

EAB (1950 M) SE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE ESE SE SE ESE ENE NNE ESE SE SE NE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE SE SSE 6.40 3.90 4.00 4.10 4.20 4.30 4.40 4.50 3.00 3.10 3.21 3.30 3.40 3.50 3.60 15.00 4.80 4.20 4.10 4.30 0.10 9.59 8.29 4.30 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 1.21 10298. 6275.

6436.

6597.

6758.

6919.

7080.

7241.

4827.

4988.

5159.

5310.

5471.

5632.

5792. 24135. 7723.

6758.

6597.

6918. 160. 15437.

13346. 6919.

1950. 1950. 1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950.

1950. 3.7E-07 1.7E-06 1.7E-06 1.6E-06 1.5E-06 1.5E-06 1.4E-06 1.4E-06 1.0E-06 1.2E-06 1.5E-06 1.8E-06 1.9E-06 1.8E-06 1.8E-06 3.5E-07 5.7E-07 1.5E-06 9.8E-07 4.1E-08 3.1E-06 2.1E-07 2.6E-07 6.8E-08 1.9E-07 1.2E-07 7.9E-08 3.8E-08 3.8E-08 7.2E-08 1.1E-07 2.3E-07 2.6E-07 2.2E-07 1.6E-07 2.7E-07 2.9E-07 4.4E-07 2.7E-07 2.4E-07 3.5E-07 1.6E-06 1.6E-06 1.5E-06 1.5E-06 1.4E-06 1.3E-06 1.3E-06 9.9E-07 1.2E-06 1.5E-06 1.8E-06 1.8E-06 1.8E-06 1.7E-06 3.1E-07 5.5E-07 1.5E-06 9.3E-07 4.1E-08 3.1E-06 2.0E-07 2.5E-07 6.6E-08 1.9E-07 1.2E-07 7.9E-08 3.8E-08 3.7E-08 7.1E-08 1.1E-07 2.3E-07 2.6E-07 2.2E-07 1.6E-07 2.7E-07 2.9E-07 4.4E-07 2.7E-07 2.4E-07 3.4E-07 1.3E-06 1.3E-06 1.2E-06 1.2E-06 1.1E-06 1.1E-06 1.0E-06 8.1E-07 9.6E-07 1.2E-06 1.5E-06 1.5E-06 1.4E-06 1.4E-06 2.9E-07 5.5E-07 1.2E-06 7.7E-07 3.9E-08 3.1E-06 1.9E-07 2.4E-07 6.6E-08 1.8E-07 1.2E-07 7.6E-08 3.6E-08 3.7E-08 7.0E-08 1.1E-07 2.2E-07 2.5E-07 2.1E-07 1.5E-07 2.6E-07 2.9E-07 4.3E-07 2.6E-07 2.3E-07 3.2E-10 7.0E-10 6.6E-10 6.4E-10 6.0E-10 5.7E-10 5.5E-10 5.2E-10 1.2E-09 1.2E-09 1.1E-09 1.0E-09 9.4E-10 8.9E-10 8.3E-10 7.6E-11 5.9E-10 6.0E-10 3.8E-10 1.8E-10 4.0E-08 1.6E-10 2.0E-10 1.3E-10 1.6E-09 1.0E-09 5.7E-10 1.9E-10 2.4E-10 4.8E.10 9.0E-10 2.0E-09 2.8E-09 2.5E-09 1.8E-09 1.8E-09 1.5E-09 2.4E-09 2.0E-09 1.9E-09 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-118

TABLE 39 (a through f) DELETED COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-119 Table 2.3-40 Frequency of Wind Resuspension Periods at Hanford (1953-1970)

Total Dust Hours 476 Total Dust Days 142 Number of Dust Storms 150 Average Dust Hr/Yr. 26.4 Average Dust Days/Yr. 7.9 Average Dust Storms Per Year 8.3 Range in Duration of Dust Storms (hr.) 1-16 Average Duration of Dust Storms (hr.) 3.2 Average Dust Storm Concentration (from Table 2) mg/m3 6.77

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-120Table 2.3-41 Dust Concentration Dependency on Wind Speed and Direction at Hanford 1953-1970 Predicted Concentration From Visibility, mg/m3 WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 WIND SPEED CLASS (MPH) 55-63 64-UP OVERALL AVERAGE 25-31 32-38 39-46 47-54 SE SSE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE .00 .00 .00

.00 .00 .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 .00 .00 1.74 .00 3.29 2.02 3.29 1.74 4.38 .00

.00 2.71 .00

.00 7.83 .00 2.71 1.74 1.74 3.49 1.88 2.60 2.92 3.38 4.60 .00 3.29 .00 .00 2.71 1.62 2.48 6.34 1.81 1.83 2.64 2.58 2.58 3.50 3.41 3.38 3.05 2.44 .00 .00 1.38 1.38 1.62 3.54 4.96 2.89 1.77 1.50 4.80 5.06 6.08 4.54 2.19 3.60 .00 .00 1.25 5.70 2.21 2.75 4.13 5.37 1.99 1.98 .00 12.99 7.04 2.81 .00 2.71 .00 .00

.00 15.92 3.86 8.83 12.95 2.71 3.29 2.23 .00

.00 7.83 .00

.00 .00 .00 .00 .00 .00 4.13 13.87 48.31 .00 4.13 .00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 .00 .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 988.88* .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 .00 .00

.00 .00 .00 .00 .00

.00 .00 .00

.00 .00 .00 .00 .00 .00 1.78 7.17 2.95 19.40 7.67 3.54 2.39 2.08 2.77 3.81 4.77 3.84 2.48 2.78 2.71 OVERALL** AVERAGE .00 2.84 3.00 3.15 4.15 3.71 8.57 22.22 .00 988.88 .00 6.77 .00 NO DATA *VISIBILITY 0 TO 1/16 MILE DUE TO ONE-HOUR DUSTSTORM **WEIGHTED AVERAGE BASED ON TABLE 2.3-42 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.3-121Table 2.3-42 Hours Satisfying Dust Storm Criteria at Hanford (1953-1970) Hours With (1) Visibility 7 Mile and Dust Reported or (2) Visibility 7 to 14 Miles, Windspeed 5.8 M/Sec: RH 70% Dust Assumed WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 WIND SPEED CLASS (MPH) 55-63 64-UP TOTAL HOURS 25-31 32-38 39-46 47-54 SE SSE S SSW SW WSW W WNW NW NNW N NNE NE ENE E ESE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 1 0 1 2 1 1 2 0 0 1 0 0

1 0 1 1 1 5 6 8 12 3 3

0 1 0 0 1

3 4 3 7 3 5 4 6 34 31 19 3 6 0 0 1

1 3 13 17 5 11 3 2 10 23 15 6 2 0 0 1

3 11 24 39 7 6 5 2 1 7 5 0 1 0 0 0

3 13 26 13 1 1 2 0 0 1 0 0 0 0 0 0

0 2 6 4 0 1 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 11 33 74 81 18 29 21 18 58 66 44 9 10 1 TOTAL HOURS 0 9 42 129 112 110 60 13 0 1 0 476 Amendment 55May 2001Rainfall Intensity, Duration, and Frequency Based on the Period 1947-69 at Hanford010126.012.3-1FigureForm No. 960690Draw. No.Rev.8.06.04.02.01.00.80.60.40.20.10.080.060.040.02A25105B10050C2D1000500Return Period (Years)51015203040502345681012182460MinutesDurationHoursIntensity (Inches per Hour)To use this chart, select any desired rainfall intensity and duration and read from the diagonal lines the expected frequency of such intensity and duration. For example, rainfall intensity of 1.3 inches per hour for 10 minutes can be expected to occur, on average, once every five years (point A). However, such intensity can be expected for 30 minutes duration only about once in 100 years (point B). The return period for intensity for 60 minutes duration is greater than 1000 years (point C).There are, of course, variations in use of the chart. Suppose, for example, it is desired to find the "100-year storm" for 60 minutes. This is 0.8 inch (point D).250Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Greatest Depth of Snow on Ground During 24 of 25Winters of Record at Hanford (1946-47 through1969-70)990306.142.3-2FigureForm No. 960690Draw. No.Rev.1008060402010864210.010.10.52510203040506070809095989999.999.99PROBABILITY (%) THAT GREATEST DEPTH WILL EXCEED GIVEN AMOUNTPROBABILITY (%) THAT GREATEST DEPTH WILL NOT EXCEED GIVEN AMOUNT99.9999.999.899959080706050403020105210.50.20.10.050.01INCHES1964-65*GREATEST DEPTH WAS LESS THAN 1 INCH DURING ONE WINTER (1957-58)98Columbia Generating StationFinal Safety Analysis Report

Amendment 55May 2001Peak Wind Gust Return Probability Diagram990306.172.3-4FigureForm No. 960690Draw. No.Rev.100AVERAGE NUMBER OF YEARS BETWEEN OCCURRENCE OF A GIVENSPEED AND THAT OF AN EQUAL OR GREATER SPEEDSPEED (MPH)1.00011.0011.0101.101.201.301.401.601.802.003.04.06.08.0 10203040 50608010020030040060080010002000300040008000Y = REDUCED VARIATEEXTREME PROBABILITY PAPERRETURN PERIOD = T908070 60 5040-2-10 1

234 5

6 7

8OBSERVED VARIATE = XJUNE 1957JUNE 1957JANUARY 1972MODEMEANColumbia Generating StationFinal Safety Analysis Report400 FT LEVEL200 FT LEVEL50 FT LEVEL Amendment 55May 2001Dust Occurrences Per Wind Speeds to 400 ftHeights990306.182.3-5FigureForm No. 960690Draw. No.Rev.400300 200100001020304050607080HEIGHT ABOVE GROUND (FT)()()(a) AVERAGE MASS OF DUST PER FOOT3, AND(b) MASS MEAN DIAMETER OF DUST PARTICLES. METEOROLOGY TOWER, HAPO. AUGUST 11, 1955(a) MASS PER CUBIC FOOT (x 10-3 GM/ft3)(b) MASS MEAN DIAMETER ()Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Near-Surface Airborne Dust Concentration as aFunction of Average Air Velocity990306.192.3-6FigureForm No. 960690Draw. No.Rev.3001001010369121518212427301950 DATADUST @ 4 FT.

WIND @ 1.5 METERS3AIR VELOCITY (MPH)DUST @ 8" WIND @ 7 FT.1/11/72 DUST STORMAIRBORNE DUST CONCENTRATION, mg/m3Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001D.P.Monthly Hourly Average of Temperature andRelative Humidity - January thru April990306.212.3-7.1FigureForm No. 960690Draw. No.Rev.JanuaryPST0204060810121416182022249080 70 60 504030 20 10PSTF and %02040608101214161820222490 80 70 60 504030 20 10FebruaryTemp. (D.B.)R.H.MarchPSTTemp. (D.B.)W.B.020406081012141618202224908070 60 50 403020 10R.H.PSTF and %F and %F and %020406081012141618202224908070 60 50 403020 10AprilTemp. (D.B.)D.P.R.H.W.B.W.B.D.P.D.P.Temp. (D.B.)W.B.R.H.Monthly and annual hourly averages of Dry Bulb (D.B.) and Wet Bulb (W.B.)Temperature Relative Humidity (R.H.) and temperature of the dew point (D.P.)(1957 - 1970)Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Monthly Hourly Average of Temperature andRelative Humidity - May thru August990306.402.3-7.2FigureForm No. 960690Draw. No.Rev.MayPSTTemp. (D.B.)W.B.D.P.0204060810121416182022249080 70 60 504030 20 10R.H.PSTF and %0204060810121416182022249080 70 60 504030 20 10JuneTemp. (D.B.)R.H.JulyPSTTemp. (D.B.)W.B.D.P.020406081012141618202224908070 60 50 403020 10R.H.PSTF and %F and %F and %020406081012141618202224908070 60 50 403020 10AugustTemp. (D.B.)D.P.R.H.W.B.W.B.D.P.Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Monthly Hourly Average of Temperature andRelative Humidity - September thru December990306.222.3-7.3FigureForm No. 960690Draw. No.Rev.Monthly and annual hourly averages of Dry Bulb (D.B.) and Wet Bulb (W.B.) TemperatureRelative Humidity (R.H.) and temperature of the dew point (D.P.)(1957-1970)SeptemberPSTTemp. (D.B.)W.B.D.P.0204060810121416182022249080 70 60 504030 20 10R.H.PSTF and %0204060810121416182022249080 70 60 504030 20 10OctoberTemp. (D.B.)R.H.NovemberPSTTemp. (D.B.)W.B.D.P.020406081012141618202224908070 60 50 403020 10R.H.PSTF and %F and %F and %020406081012141618202224908070 60 50 403020 10DecemberTemp. (D.B.)D.P.R.H.W.B.W.B.D.P.Columbia Generating StationFinal Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.032.3-8.1FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.112510203040506070809095989999.999.99N(Hours)PercentAn inversion runof N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 dataJan-Feb14Columbia Generating Station Final Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.022.3-8.2FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.112510203040506070809095989999.999.99N(Hours)PercentAn inversion runof N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 dataMarch-AprilMay-June108Columbia Generating StationFinal Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.042.3-8.3FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.512510203040506070809095989999.999.99N(Hours)PercentAn inversion runof N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 dataJuly-Aug118Sept-OctColumbia Generating Station Final Safety Analysis Report Probability (%) that the First Hourly Observationof an Inversion will Mark the Beginning of anInversion Run of N Hr990306.052.3-8.4FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.100806050403020108654320.010.10.512510203040506070809095989999.999.99N(Hours)Percent15Nov-DecColumbia Generating StationFinal Safety Analysis ReportAn inversion run of N hours is N consecutive hourly observations of inversion (T200 -T3 >0.0)plotted points based on 1952-1969 data Amendment 55May 2001Topographic Cross Sections of RegionSurrounding Site990306.232.3-9FigureForm No. 960690Draw. No.Rev.600400MSL FT.600400600400600400800600400800600400800600400800MSL FT.MSL FT.MSL FT.SSWSWWSWW WNW NW NNWNorthNNENEENEE ESE SE SSESOUTH1086420246810km(6.2 mi.)Plant Site600400Plant SiteColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Yearly Hourly Average of Temperature andRelative Humidity990306.242.3-10FigureForm No. 960690Draw. No.Rev.Monthly and annual hourly averages of Dry Bulb (D.B.) and Wet Bulb (W.B.) TemperatureRelative Humidity (R.H.) and temperature of the dew point (D.P.)(1957-1970)AnnualPSTF and %Temp. (D.B.)W.B.D.P.02040608101214161820222490807060504030 2010R.H.Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Hourly Centerline( /Q at Site Boundary Circular Distance of 1.212Miles From Source (April 1974-March 1975)990306.252.3-11FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than)Wake FactorNo Wake FactorColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Hourly Centerline( /Q at Site Boundary Circular Distance of 1.212Miles From Source (April 1975-March 1976)990306.262.3-12FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than)Wake FactorNo Wake FactorColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Occurrence of (/Q for PostulatedAccidents of 8, 16, 72, and 624 Hr at Outer Boundary of LowPopulation Zone (3.0 Miles from Source) (April 1974-March 1975)990306.272.3-13FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than).624 Hours72 Hours8 Hours (Wake Factor)8 Hours (No Wake Factor)16 HoursColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Cumulative (%) Frequency of Occurrence of ( /Q for PostulatedAccidents of 8, 16, 72, and 624 Hr at Outer Boundary of LowPopulation Zone (3.0 Miles from Source) (April 1975-March 1976)990306.282.3-14FigureForm No. 960690Draw. No.Rev.0.010.050.20.51251020304050607080909510-310-410-510-610-710-8/Q (sec/M3)/Q (sec/M3) Cumulative Probability (% Greater Than)624 Hours72 Hours8 Hours (Wake Factor)8 Hours (No Wake Factor)16 HoursColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Annual Average /Q by Sector at the SiteBoundary for First and Second Annual Cycle Data990306.292.3-15FigureForm No. 960690Draw. No.Rev.10-5NNNENEENEEESESESSESSSWSWWSWWWNWNWNNW10-610-710-8Down Wind Sector(Solid Line is for 4/74 - 3/75 data;dashed line is for 4/75 - 3/76 data)No Building Wake FactorBuilding Wake Factor IncludedColumbia Generating StationFinal Safety Analysis Report CHI/Q (sec/m3)

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.4-1 2.4 HYDROLOGY ENGINEERING The italicized information is historical and was provided to support the application for an operating license.

2.4.1 HYDROLOGIC DESCRIPTION

2.4.1.1 Site and Facilities Columbia Generating Station (CGS) is located in the Hanford Site within Benton County, Washington, approximately 3 miles west of the Columbia River at river mile (RM) 352, 10 miles north of Richland and 45 miles downstream from Grant County PUD Priest Rapids Dam. The site coordinates are approximately 46° 28' North Latitude and 119° 20' West Longitude. The Columbia River is the predominant hydrologic feature of the area and provides principal drainage for the surrounding area. The riverbed is clearly marked in the terrain and at the proximity of the site the river flows between high banks. The Columbia River approximate riverbed elevation is 328 ft above mean sea level (msl); the ground elevation at the site is approximately 440 ft. Another hydrologic feature of the area is the Yakima River, which at its closest approach flows within 8 miles of the plant site. The river system is shown in the hydrographic map, Figure 2.4-1. Figures 2.1-1 and 2.1-2 show the major hydrologic features of the area.

All Seismic Category I structures are located above maximum postulated flood elevations. For flood elevations refer to Sections 2.4.3 and 2.4.4.

Water for cooling tower makeup water and other plant requirements is withdrawn from the Columbia River. The intake system is designed for a maximum capacity of 25,000 gpm (55.7 cfs). The non-safety-related makeup water intake system is approximately 3 miles east of the plant and is made up of two offshore perforated pipe inlets, two lead-in pipes, and pump house structure.

A topographic map and contour map of the region surrounding the site are shown in Figures 2.4-2 and 2.4-3. The natural drainage features of the surrounding area have not been changed by the construction of CGS.

2.4.1.2 Hydrosphere The Columbia River, the largest river flowing into the Pacific Ocean from North America, is one of this world's greatest sources of hydroelectric power. Its annual discharge of 18,000,000 acre ft (1 acre-ft = 43,560 ft3) is exceeded in the North American continent only by the Mississippi, Mackenzie and St. Lawrence Rivers.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-2 The Columbia River drains an area of approximately 258,000 square miles, lying to the west of the Continental Divide in the northwestern part of the U.S. (85%) and southwestern part of Canada (15%). Major tributaries are the Kootenay, Snake, Pend Oreille, Spokane, Okanogan, Yakima, and Willamette Rivers. In determining the Standard Project Flood (SPF) the drainage area was divided into subbasins. These subbasins can be grouped into six general areas with similar hydrometeorological characteristics.

The six areas are: (1) upper Columbia, which includes the drainage of the area in Canada and the northern part of the United States above Chief Joseph Dam; (2) Middle Columbia, which includes the area between Pasco and Chief Joseph Dam; (3) Upper and Middle Snake River; (4) Lower Snake River, the area between Weiser and Ice Harbor Dam; (5) Lower Columbia, including the area between Bonneville Dam and Pasco; (6) the Columbia below Bonneville Dam, including the Willamette River.

The river basin has five outstanding physical features: the Rocky Mountain System, the Columbia Plateau, the Columbia River Gorge, the Cascade Range and Puget Trough.

The Rocky Mountain System is the major range with elevations from 2000 to over 12,000 ft. There are permanent glaciers and extensive snow fields at higher elevations and deep valleys that provide the principal drainage for the head-waters of the Columbia, Kootenay and other rivers.

The Columbia Plateau is a great, generally treeless, semiarid plateau covering over 100,000 square miles in the central portion of the basin. This plateau is in an area between the Cascade Range and the Rocky Mountains. The plateau was formed by successive flows of lava and filled to a general thickness of approximately 4000 ft. The Columbia River flows 1214 miles from its source in Columbia Lake (el. 2700 ft) in British Columbia, near the crest of the Rockies, to the Pacific Ocean at Astoria, Oregon. It sweeps around the north and northwesterly sides of the Columbia Plateau to central Washington to be joined by the Snake River. The Columbia River flows directly across the axis of the Cascades in a narrow gorge to the Pacific.

The Columbia Gorge is the gateway from the Pacific Ocean to the intermountain Columbia Plateau. Tide flows 140 miles up-river. For most of its length the river flows in deep valleys and canyons.

High flows occur in late spring and early summer with melting of snow on the mountainous watershed. Low flows occur in autumn and winter.

The Columbia River has been regulated by dams and reservoirs over the past 35 years. A large portion of the main stream and major tributaries is developed to meet various COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.4-3 functional requirements, such as flood control, hydroelectric power, irrigation, municipal and industrial supply, etc. The regulation of Columbia River floods is accomplished by use of reservoir storage space provided primarily for irrigation or for hydroelectric power utilization. The volume of usable reservoir storage space is on the order of 20% to 25%.

There are seven dams upstream and four dams downstream of the site on the main stream of the Columbia River within the U.S. These dams are listed in Table 2.4-1. The Columbia River flow in the reach of CGS is controlled by regulation of the upstream reservoir projects, which have a total usable storage capacity of approximately 35 million acre-ft. Some control of flow in the immediate vicinity of the site is by regulation of the nearest upstream hydroelectric projects, Priest Rapids Dam, at RM 397, containing about 45,000 acre-ft of active storage, and Wanapum Dam, at RM 415, containing about 161,000 acre-ft of active storage. Some minimal effect on the river flow in the vicinity of the site is caused by McNary Dam, at RM 292, approximately 60 RM downstream from the site area.

Flows in the Columbia River during the summer, fall, and winter vary from a low of 36,000 ft3/sec to as much as 160,000 ft3/sec. During spring runoff high flows ranging from 250,000 ft3/sec to 450,000 ft3/sec have been recorded. The average annual flow is 120,000 ft3/sec; during low flow periods flows may average about 60,000 ft3/sec (see Figure 2.4-4).

The Grand Coulee and Bonneville dams were put into operation prior to World War II and several dams were built after the war. The four downstream dams include large locks to permit the passage of river vessels. Several of the dams provide emergency floodwater storage. Grand Coulee, the largest and most complex of the dams, augments the low winter flows for the entire system from its 9,402,000 acre-ft of available storage (of which approximately 5,100,000 acre-ft is active storage) and also pumps water to the Columbia River Irrigation Project.

The river channel near the CGS site varies between 400 and 600 yards in width for low water and normal high water level, respectively. The depth varies from about 25 ft to 45 ft for normal high water and flood high water levels, respectively. Velocities vary from 3 ft/sec to over 11 ft/sec depending on section and flow. Average water temperature is 51°F. Temperatures may reach a low of 32°F and a high of 68°F. (See Table 2.4-2 and Figure 2.4-4.)

A list of water usage downstream of CGS, obtained from records of the Department of Ecology, State of Washington, for water rights as of February 1980, is presented in Table 2.4-3. The closest municipal surface water user is the City of Richland with an intake approximately 12 miles downstream. The location of local groundwater users is discussed in Section 2.4.13.2.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 LDCN-02-000 2.4-4 2.4.2 FLOODS

2.4.2.1 Flood History Floods in the Columbia River Basin are grouped as: a. The interior basin east of the Cascades, caused by melting snowpack and occurring from May through June; b. The Willamette and other basins, west of the Cascades, caused by direct runoff from intense winter rain occasionally augmented by snowmelt. There is some overlapping effect within these two groupings. At certain elevations, basins in the interior Columbia drainage area occasionally have significant flood flows resulting from winter rain or snowmelt. These are local floods and do not usually contribute sufficient flow to cause flooding of the main Columbia River. Major floods in the Columbia River Basin result from rapid spring melting of the snowpack over a wide area, generally augmented by rain or by above-normal precipitation in May, accompanied by a major chinook wind which causes rapid area temperature rise. The annual spring snowmelt flood of the main interior basin is characterized by relatively uniform distribution over the basin. The snowfall and individual snow storms may vary, but the integration of all storms over the winter period smoothes the irregularities, with the result that the distribution of the flood runoff is reasonably constant from year to year.

The maximum historical flood of record is that of June 7, 1894, which resulted from a combination of hydrometeorologic conditions, including heavy snowpack and rapid melt plus rainfall. The peak discharge at CGS was 740,000 ft3/sec for the Columbia River, as estimated from high water marks at Wenatchee, Washington (Reference 2.4-1). The largest recent flood, occurring in 1948, had an observed peak discharge of 690,000 ft3/sec at Hanford. These floods were spring floods resulting from the melt of a large snowpack combined with the spring rains (Reference 2.4-2). Water surface profiles for the Columbia River in the vicinity of the site as derived by the Corps of Engineers (Reference 2.4-2) are given in Figure 2.4-5.

The plant site is located approximately three miles west of the Columbia River at RM 352 with reactor floor elevation of 441 ft msl, which is 68 ft above the water level estimated for the largest historical flood (approximately 373 ft msl). There is no record of flooding in the immediate site area.

2.4.2.2 Flood Design Considerations Flood protection of safety-related components is based on the highest calculated flood water level including wave effects, resulting from intense local precipitation. Several different probable maximum events were considered, including the Corps of Engineers design-project COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 LDCN-03-069 2.4-5 flood considered to be "the most severe reasonably possible." Wave action caused by storm winds, the effects of failure of upstream dam surge flooding, and ice flooding were also considered.

The results of these analyses (described in Section 2.4.3) indicate that the CGS site is safe from floods and that no flood protection measures are required. The Hydrogen Storage and Supply Facility located 0.6 miles south-southeast of the plant is subject to flooding due to the PMP flood discussed in Section 2.4.3.1. Equipment storing liquid and gaseous hydrogen has been analyzed for the effects of this flood (Section 2.4.2.3). As discussed in sections that follow, plant safety-related structures are located above high water elevations associated with Columbia River flooding (Sections 2.4.2.1 and 2.4.3), intense local precipitation (Sections 2.4.3.5 and 2.4.3.6), and upriver dam failures (Section 2.4.4).

2.4.2.3 Effects of Local Intense Precipitation Intense local summer thunder storms can produce short duration rains which have the potential for causing serious flood. Winter precipitation may occur as rain or snow and would be less intense than the worst summer thunderstorm. The probable maximum precipitation (PMP) event for the CGS site has been determined using the methodology developed by the U.S. Weather Bureau and reported in Hydrometeorological Report No. 43, "Probable Maximum Precipitation, Northwest States" (Reference 2.4-3).

The plant area slopes easterly to a broad channel which is adequate to store and drain the PMP. Construction contours of the site are shown in Figure 2.4-28. The reactor building and the spray ponds are located at elevations that are safe from the effect of any flood resulting from the maximum precipitation event.

Winter precipitation may occur as rain or snow. The winter season snowfall has ranged from less than 0.5 in. to a maximum of 12 in. in December 1964. There is no ice accumulation at the site.

To accommodate surface drainage during severe climatic conditions such as rainfall and rapid snow melts, a system of catch basins and dry wells is provided with inlet elevations a minimum of 6 in. lower than the nearest road and a minimum of 12 in. lower than the finished floor elevation of the nearest building(s). Runoff from the PMP event is accommodated by designing the roadways such that the high point of the road is 6 in. to 1 ft below the finished floor elevation of the adjacent safety-related building(s). Runoff from this event is from the northwest to the southeast across the site plateau to the low area southeast of the plant site. The general plant site is nominally 9 ft above the maximum calculated water surface elevation resulting from the postulated PMP (Section 2.4.3.3). Therefore, the site grading precludes the potential flooding of safety-related structures. The Hydrogen Storage and Supply Facility is subject to the PMP event flooding.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-13-050 2.4-6 The elevation of the facility is 420 ft msl and the PMP flood level is 431.1 ft msl (Section 2.4.3.5). See Section 10.4.10 for more discussion.

Roofs of buildings are designed to take, with adequate drainage, any instantaneous or local intense precipitation. Discharge from roof drains is carried by means of a storm sewer system to a manhole located southeast of the reactor building. From that point a pipeline with a northeast alignment transfers the discharge to lined evaporation ponds about 1500 ft away from the plant site.

The roofs of safety-related buildings (diesel generator building, radwaste/control building, standby service water pump house) are concrete beam and slab construction except the high roof of the reactor building, which is metal deck on steel framing. The minimum roof slope for all structures is 1/8 in. per ft for adequate drainage and the roof areas are encompassed by curbs or parapet walls up to 3 ft 6 in. high. Roof plans, including details of roof drains and overflow scuppers, are provided in Figure 2.4-6. Assuming that the roof drains are completely blocked during the PMP event, overflow scuppers limit the depth of water to within the design load carrying capability of the roofs. Those safety-related structures that do not have this relief capability structurally can carry the entire PMP accumulations. 2.4.3 PROBABLE MAXIMUM FLOOD ON STREAMS AND RIVERS Analyses for probable maximum flood (PMF) and SPF on the Columbia River (Reference 2.4-2) are consistent with the requirements of Regulatory Guide 1.59, Revision 2. The SPF for the Mid-Columbia Reach of the highly developed and regulated Columbia River is defined as 570,000 ft3/sec (Reference 2.4-4). The unregulated SPF for the same reach is 740,000 ft3/sec. The unregulated PMF at the site is estimated to be 1,600,000 ft3/sec (References 2.4-2, 2.4-4, and 2.4-5).

Adjustment of the flood profiles for the Hanford region reported in Reference 2.4-4, results in a regulated PMF of 1,440,000 ft3/sec and a water level of 390 ft at the Seismic Category II makeup water structure. This structure is not designed to function throughout the PMF but is designed for the SPF (unregulated) of 740,000 ft3/sec.

Although assumed to exist for the purpose of flood hydrograph calculations, Ben Franklin Dam is not a federally authorized project. As originally planned it would have been a low head dam with only a negligible effect on extreme flood flows (Reference 2.4-6). The design basis flood for the CGS site area results from the PMP event on the adjacent drainage basin and not from flooding of the Columbia River.

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-12-020 2.4-7 2.4.3.1 Probable Maximum Precipitation The PMP event which was presented in the CGS PSAR was subsequently reevaluated in the preparation of the PSAR for WPPSS Nuclear Project No. 1 (Docket 50-460). The analysis presented here is consistent with the latter document.

Precipitation in the vicinity of the site has been classified by the U.S. Weather Bureau, Reference 2.4-3, as convergence precipitation, orographic precipitation, and thunderstorm precipitation. The methodology for predicting the total amount of precipitation from each of these events, as given in Reference 2.4-3, requires the adding together of the convergence PMP and the orographic PMP to obtain a single precipitation for a general storm. A separate analysis is then required for thunderstorms. Thunderstorms in the vicinity of the site can be locally very intense for short periods of time and hence, have the potential for causing serious flooding. The PMP for both a general storm and a thunderstorm were analyzed as given in Chapters 6 and 5, respectively, of Reference 2.4-3 for a 38.5 mile2 basin at the site. This basin is shown in Figure 2.4-8 and is described in Section 2.4.3.3. The calculated general storm PMP results in a 24-hr and 48-hr precipitation of 7.9 in. and 10.1 in., respectively.

A thunderstorm PMP yields 9.2 in. in a 6-hr period. Therefore, the thunderstorm is considerably more severe. The thunderstorm PMP hydrograph is Time Rain (hr) (in.) 1 0.6 2 1.6 3 5.2 4 0.9 5 0.5 6 0.4 Total 9.2

2.4.3.2 Precipitation Losses Infiltration losses have been estimated in the vicinity of the sites as 1.5 in./hr (Reference 2.4-7). However, for the analysis below, an average antecedent moisture condition (Condition II as defined in Reference 2.4-8) was assumed. As explained in the following section, the 60-minute retention loss rate is 0.15 in./hr.

2.4.3.3 Runoff and Stream Course Models The drainage basin common to the reactor building and spray ponds is shown in Figure 2.4-8. The entire area drains to a broad channel that extends in a north-south direction for about 7 miles, and ranges from about 2000 ft to over a mile wide. All plant structures are located on COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-8 high ground to the west of the channel. At a point about 2.8 miles south of the reactor site, the four-lane Department of Energy (DOE) highway crosses the drainage basin. The area above this section is 33.2 miles2. To evaluate the effect of the PMP event on the plant area, the peak discharge at the highway crossing, 2.8 miles downstream of the plant, was calculated using the U.S. Bureau of Reclamation procedure for computing design floods on ungauged basins from thunderstorm rainfall in the western U.S. (Reference 2.4-8). Important assumptions used in the triangular hydrograph procedure of Reference 2.4-8 are a. Hydrologic soil group B,

b. Land use and treatment class - poor pasture or range,

c. Thunderstorm cover-index is brush-sage-grass combination with 50% or less cover density, and

d. Thunderstorm minimum 15-minute retention loss rate of 0.06 in./15 minutes and 60-minute retention loss rate of 0.15 in./hr.

Additionally, no credit was taken in the hydrograph analysis for potential storage in the stream channel or upstream sub-basins.

The time of concentration, Tc, for the watershed above the highway crossing was computed to be 7.5 hr. The PMF hydrograph is shown in Figure 2.4-7 for the 33.2 mile2 drainage basin. A peak discharge of 21,400 ft3/sec was determined.

Based on this PMF, an upstream water surface profile was determined using the Corps of Engineers HEC Standard-Step Procedure (Reference 2.4-9). A total of eleven cross sections were used (seven downstream, one at the plant, and three upstream as shown in Figure 2.4-3). Details of the channel cross sections are shown in Figure 2.4-9. The Manning roughness coefficient was conservatively taken as n=0.035 in the main channel sections, and n=0.05 in the overbank areas.

Using the computational procedure of Reference 2.4-9, it was determined that the channel restrictions at cross sections 5 and 7 (Figure 2.4-3) do not control the flow. The stillwater elevation at the plant site (cross section 8) was determined to be 431.1 ft msl. The water surface profile is shown in Figure 2.4-10.

2.4.3.4 Probable Maximum Flood Flow The PMF runoff hydrograph produced by the PMP at cross section 1 (Figure 2.4-3) is shown in Figure 2.4-7. The peak discharge at this location is 21,400 ft3/sec.

COLUMBIA GENERATING STATION Amendment 62 FINAL SAFETY ANALYSIS REPORT December 2013 LDCN-12-043 2.4-9 2.4.3.5 Water Level Determinations As discussed in Section 2.4.3.3, the water elevation of a flood at the plant site generated by the PMP event is 431.1 ft msl. This flood condition has a higher estimated elevation than any flood of the Columbia River.

2.4.3.6 Coincident Wind Wave Activity Procedures published by the Corps of Engineers (References 2.4-10 and 2.4-11 were used to determine the wind wave activity. The effective fetch for the predominant July wind direction (north) is 3450 ft (0.65 miles). The effective fetch diagram is shown in Figure 2.4-11. The calculated extreme 2-year over water wind for the north-to-south direction, based on area data, is 63.5 mph. This wind results in a maximum wave height of 4.0 ft, with the assumption of a water depth of 12 ft (the average depth in cross sections 8, 9, and 10). The other potential wind directions ENE and ESE were evaluated but found to be less severe. The wind setup has been computed to be 0.3 ft, and the maximum wave runup is 1.9 ft on a smooth, 1 on 8 slope of compacted naturally occurring sands and gravels. Therefore, the design water surface elevation is 433.3 ft msl. This is less than the east spray pond overflow weir at elevation of 434.5 ft msl.

2.4.4 POTENTIAL DAM FAILURES, SEISMICALLY INDUCED

Analyses of floods resulting from potential dam failures were investigated by the Corps of Engineers for the Columbia River. These studies are consistent with Regulatory Guide 1.59, Revision 2. The flood resulting from the breaching of Grand Coulee Dam is considered in lieu of a seismically induced flood.

In 1951, the Seattle District Corps of Engineers made a confidential study (now declassified) to determine artificial flood hydrographs and the flood profile in the Columbia River Valley resulting from breaching the Grand Coulee Dam by enemy attack. The studies covered a spectrum of conditions in terms of breach openings and hydrologic conditions that might prevail at the time of attack. A postulated seismic failure of Grand Coulee Dam could result in displacement of part of the structure, but it would still act as a restriction or weir and minimize the hydraulic failure. For this reason, the explosion-induced artificial flood represents an upper limit to seismically induced failures. The failure of Grand Coulee Dam would initiate a catastrophic flood, which would be augmented by the failure of the earth portions of downstream dams and subsequent release of the storage pools. Figure 2.4-5 shows water surface profiles for RM 323 to RM 358 for various river flows, including Artificial Flood No. 1. This flood provides a "limiting case" assessment of the conservatism of CGS elevation. This flood would have an outfall peak of 8,800,000 ft3/sec at Grand Coulee Dam at the moment of breaching and a peak discharge at RM 338 (Richland) of 4,800,000 ft3/sec.

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-10 A base flow of 50,000 ft3/sec was assumed above the mouth of the Snake for this flood (Reference 2.4-12). An arbitrarily assumed dramatic failure of Arrow and/or Mica Dams in Canada could result in greater releases of storage in terms of volume than that from the Grand Coulee Dam, but the effects of such postulated releases are mitigated by a combination of valley storage and critical (flow limiting) valley cross sections. The Corps of Engineers states (Reference 2.4-13) that the river channel restrictions at Trail, British Columbia, would restrict river flow to about 3.1 x 106 cfs, regardless of the postulated dam failure. A major failure upstream would result in this maximum flow for many days causing overtopping of Grand Coulee Dam. An analysis by the Bureau of Reclamation (Reference 2.4-14) concluded that overtopping which might result from the failure of upstream dams will not cause failure of either the Grand Coulee Dam or the Forebay Dam.

Various studies (References 2.4-12, 2.4-15, 2.4-16 and 2.4-17) made by the Corps of Engineers, and others, since 1951 have considered that breaching of Grand Coulee Dam would represent the worst catastrophic event for downstream Columbia River occupants. Although these studies bear no relationship to flooding from natural causes, they have been used as the basis for a very conservative, limiting case approach.

Figure 2.4-5 shows water surface profiles for RM 323 to RM 395 for artificial and real stage flows, one of which corresponds to Artificial Flood No. 1 noted earlier, which has been established (Reference 2.4-18) as conservative (limiting case) criteria for Columbia River flooding. Since the base flow used to develop these curves was 50,000 ft3/sec, an additional 570,000 ft3/sec is added to account for simultaneous occurrence of the regulated SPF.

2.4.4.1 Dam Failure Permutations The effect of potential dam failure on the water levels at the site is determined using the following assumptions:

a. The Columbia River is at flood stage, with a SPF (570,000 ft3/sec regulated);

b. The reservoirs in each storage pool are full; c. A massive hydraulic failure occurs at Grand Coulee Dam, releasing 8,800,000 ft3/sec; d. Following the above assumed failure, all downstream dams between CGS site and Grand Coulee Dam suffer some degree of failure and release their storage reservoirs to the flood. [The result of a stability analysis (Reference 2.4-15) showed that all mass concrete portions of the dams will resist sliding and overturning with the possible exception of part of Rock Island Dam.];

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-11 e. The explosion-induced failure of Grand Coulee Dam represents a more severe failure than any seismic event because of the failure mechanism;

f. Failure of Arrow and/or Mica Dam could result in greater release of storage volume than Grand Coulee Dam; however, the peak flow is limited to 3,100,000 ft3/sec due to channel restrictions at Trail, British Columbia; and

g. Overtopping of Grand Coulee Dam would occur with failure of Arrow and/or Mica Dams in Canada. The failure of Grand Coulee, as a result of overtopping, is not considered to be a credible event in view of its concrete construction and rock abutments.

2.4.4.2 Unsteady Flow Analysis of Potential Dam Failures The flood hydrographs developed by the Corps of Engineers are based on the results of extensive studies of the physical characteristics of the flood route (References 2.4-12 and 2.4-15). Subsequent studies made by the Corps of Engineers verify these results (Reference 2.4-17). Water levels following such a flood would depend on the status of reservoir storage upstream from Grand Coulee Dam but, without regulation of some dams, would approximate the natural seasonal flow conditions.

2.4.4.3 Water Level at Plant Site The water elevations associated with limiting case flood (LCF) levels are shown in Figure 2.4-5. RM 350 provides the control for backwater flow to the plant area which is sheltered by higher ground east of WNP-1 and WNP-4. Elevation at RM 350 (dam breach flood = 422 ft msl 4,800,000 ft3/sec plus SPF, 570,000 ft3/sec)

Allowance for simultaneous wind and wave action + 2 ft Elevation: 424 ft msl=LCF An adequate margin exists between the resultant flood elevation and the plant elevation of 441 ft msl.

2.4.5 PROBABLE MAXIMUM SURGE AND SEICHE FLOODING The location of the CGS site is not close to any water body which experiences seiche flooding. Thus the site is not vulnerable to such flooding.

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-12 2.4.6 PROBABLE MAXIMUM TSUNAMI FLOODING The location of the CGS site is in south-central Washington and it is not adjacent to any coastal area. It is not, therefore, vulnerable to tsunami flooding.

2.4.7 ICE EFFECTS Historically, the Columbia River has never experienced complete flow stoppage or significant flooding due to ice blockage. Periodic ice blocking has caused reduced flows and limited flooding for only relatively short periods of time. The most significant icing in recent recorded history occurred during the winter of 1936-37 prior to the construction of the upstream regulating dams. A relatively thick sheet of ice formed across the river. The minimum flow recorded near the Priest Rapids Dam site during this winter was 20,000 cfs. However, the ice forming on the river was caused primarily by the low flow rather than the reverse. The deltaic mouths of many of the tributaries to the Columbia River are frequently blocked by ice causing backup of flood waters. No instance of complete stoppage is known to have occurred.

Ice blockage is most likely to occur when water temperatures are already low, when flows are small, and when a significant cold spell occurs. With the completion of Grand Coulee and other dams on the Columbia River main stream, the seasonal temperature and flow cycles have drastically changed. These changes will further aid to reduce the intensity and timing of the conditions which may contribute to potential ice blockage and flooding situations. Also average river flow rates, during the winter months, have been increased significantly. The water temperatures have shown a shift in time such that the peak temperatures occur 30-45 days later than formerly. In addition, the low extreme temperatures measured have risen over the years.

The long term trends of temperatures in the Columbia River been studied (Reference 2.4-19) using a 37 year record of measured temperatures. The trends for the maximum, average and minimum temperatures are shown in Figure 2.4-12. The erection of dams on the upper Columbia River has caused the extreme high and low river temperatures measured at Rock Island Dam (Columbia RM 453, 101 miles above the CGS site) to converge toward the average. Winter water temperatures are considerably warmer and summer temperatures cooler with a slightly lowered average of less than 1°F occurring during the 37 years.

On the basis of these studies and the recorded observation of 25 years of operation of the Hanford plutonium production plants, it is concluded that the potential for ice blockage or the combination of blockage and flooding behind ice dams is so low as to be considered insignificant. The erection of Mica, Arrow, and Libby Dams in the Columbia River Basin headwaters is expected to further raise winter water flows and also to increase winter water temperatures somewhat.

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-13 In any event, ice flooding will not effect the capability to shut down the reactor in a safe and orderly manner. Also, the daily fluctuating stage of the river at the intake location will discourage formation of sheet ice as well as ice jams. Ice flows, should they occur, will normally pass over intake structure due to relatively high winter discharge in the river. 2.4.8 COOLING WATER CANALS AND RESERVOIRS

There are no cooling water canals. The two spray ponds located southeast of the reactor building designed as Seismic Category I structures, have reinforced concrete side walls, and reinforced concrete base mats at el. 420 ft msl. The finished grade at the spray ponds is approximately at el. 434 ft msl and have top of wall elevations of 435 ft msl. The spray ponds are the ultimate heat sink for normal reactor cooldown and for emergency cooling.

The spray ponds are a part of the standby service water system which is discussed in Section 9.2.7. See also Section 2.4.11.6.

During normal reactor operation, the cooling water necessary for the plant is supplied from the cooling tower basins.

2.4.9 CHANNEL DIVERSIONS

The Columbia River flow in the Hanford reach is controlled to a large extent by regulation of the upstream reservoir projects. The riverbed in the vicinity of the site is well defined and it is very unlikely that the riverbed would be diverted from its present location by natural causes. Any possible effect on water supply to the makeup water pump house from riverbed changes would come from extremely slow changes which can be corrected if and when they occur.

As discussed in Section 2.4.7, the river has not frozen over in Hanford reach during at least the past 25 years, and icing on the river has not been a problem at pump house or outfall structures associated with the plutonium production plants.

2.4.10 FLOODING PROTECTION REQUIREMENTS

The design considerations of safety-related facilities to withstand floods and flood waves are described in Section 2.4.2.2. The PMF is discussed in Section 2.4.3.

All safety-related facilities are housed in Seismic Category I structures protected from flooding and designed to withstand the static and dynamic forces of all postulated floods. Flood considerations are described in Section 3.4 and the design of Seismic Category I structures, for all conditions including flood, is described in Section 3.8.

In the event of a flood at the site, it will be possible to place the plant in a safe shutdown condition.

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-14 All non-safety-related facilities with the exception of the makeup water pump house, are above the LCF elevation. The flooding of the makeup water pump house would not affect safety-related equipment and would not affect the safe shutdown of the plant. The approximate finished grade at all Seismic Category I structures except the spray ponds is at elevation 440 ft msl. The finished grade of the spray ponds is 434 ft msl.

The PMF elevation of the Columbia River (described in Section 2.4.3), at the site, is estimated to be 390 ft msl. Seismic Category I structures are designed to withstand the static and dynamic forces which could result from a flood due to a breach of Grand Coulee Dam. Since this represents the LCF, the structures are also considered secure against the forces due to the lower PMF.

The access openings to all seismic Category I structures are located well above all flood water elevations, including that due to wind and wave action.

2.4.11 LOW WATER CONSIDERATIONS

As described in Section 2.4.1.1, plant water needs are supplied through an intake structure in the Columbia River. The top of the makeup water intake screens (at RM 352) are set below the water surface elevation that would be associated with the minimum allowable flow (36,000 cfs) at the federally licensed Priest Rapids Dam (at RM 397). Water levels at the CGS intake are not influenced by backwater from the downstream McNary Dam (RM 292). The Columbia River Basin upstream of CGS has in excess of 35 million acre-ft of usable reservoir storage capacity. Because of this storage and highly regulated river flows, it is improbable that flows below the licensed minimum will occur. Based on data for 1961 through 1994, 7-day low flow with a recurrence interval of 100 years has been estimated at 44,500 cfs.

Even if some event (e.g., very severe drought) caused the makeup water system to be inoperable, the loss of water would not compromise the safe shutdown of the plant. As is discussed in Sections 9.2.5 and 9.2.7, shutdown cooling water is supplied by the ultimate heat sink which contains a 30-day supply of water in two spray ponds. The only scenario in which the makeup water pump house is called on to supply water in an emergency situation is when a tornado removes a significant quantity of spray pond water (see Section 9.2.5.3). Therefore, the low river water condition is not a situation requiring safety-related features and procedures.

2.4.11.1 Low Flow in Streams Reservoir projects on the Columbia River Basin upstream of the proposed site have a total usable storage capacity in excess of 35 million acre-ft. This capacity is sufficient to maintain a flow in the Columbia River, at the proximity of CGS, of 36,000 ft3/sec for over 1 year with absolutely no inflow from other sources. Because of this regulation, the anticipated minimum COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-15 and maximum monthly mean flow rates will be 60,000 and 260,000 ft3/sec in the vicinity of the site. It is improbable that minimum flows below that administratively set for dam operation (36,000 ft3/sec) will occur due to drought conditions. Columbia River storage measurements have been extrapolated down to 25,000 cfs and are shown in Figure 2.4-13. The river elevation at RM 352, site of the CGS makeup water pump house, is 341.73 ft msl and has a corresponding flow of 36,000 ft3/sec. 2.4.11.2 Low Water Resulting From Surges, Seiches, or Tsunami There exists no possibility of low water conditions resulting from meteorological or geoseismic generated surges, seiches, or tsunami unless such natural phenomena effected rapid closure of the Priest Rapids Dam, which is located 45 miles upstream from the proposed site. Rapid closure of the dam would cause a negative surge to be generated downstream. A complete stoppage of flow is an unlikely event because of the redundant equipment and operational procedure in place at the dam. Provisions to guard against an accidental shut off of Priest Rapids Dam include:

a. A gate actuation button in the control room of the Dam which is used to maintain at least minimum licensed flow from the facility in the event of one or more turbine shutdowns.

b. Independent motors on each gate which have redundant wiring and power supplies.

c. Electrical heating on four of the gates to prevent ice buildup which might interfere with gate operation.

d. Multiple offsite power sources in addition to an on-site diesel generator power backup for gate operation.

In the event of a rapid and complete stoppage of flow over Priest Rapids Dam the effect of the negative surge would pass the site in a few hours. Since the Priest Rapids Dam is a run of the river dam with low storage capacity, it is unlikely that its closure can restrict the Columbia River flow for a significant period of time before being topped.

2.4.11.3 Historical Low Water Historical records of the U.S. Geological Survey gauging station (RM 394.5) located 2.6 miles downstream from Priest Rapids Dam show low daily averaged flows of 20,000 ft3/sec (January 31, 1937) and low monthly averaged flows of 20,900 ft3/sec (February 1937). An instantaneous low flow of 4120 ft3/sec occurred February 10, 1932, due to activities connected with dam regulation of the river near Wenatchee, Washington, before construction of Priest COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-16 Rapids Dam. After completion of the Dam in 1956, the minimum flow rate of the Columbia River at RM 352, approximate location of the CGS makeup water pump house site, is 36,000 ft3/sec. The flow is maintained by the Grant County PUD as operator of the Priest Rapids Dam (RM 397) under FPC license which states: "The licenses shall so regulate the flow from the Project 2114 that it will not result in flows of less than 36,000 cfs of water at the Hanford Works of the Atomic Energy Commission except when conditions are beyond the licensee's control."

In eighteen years of operation the flow has not dropped below the specified minimum.

The annual average flow of the Columbia River below Priest Rapids Dam is in the range of 115,000 cfs. The effect of use of upstream water for irrigation development on the stream flow has been taken into account and the modified mean monthly discharge variations for the period 1928-58 are shown in Table 2.4-4 and Figure 2.4-14. The discharge for the base period of 1929-58 was adjusted to reflect 1970 levels of water utilization, including water consumption due to activities of flood control, power generation and irrigation. Figure 2.4-15 shows the exceedance frequency for annual low flows for the period 1929 through 1958 with 1970 conditions measured at the gauging station (RM 394.5) immediately below Priest Rapids Dam. Because of the flow regulation on the Columbia River, the anticipated minimum and maximum monthly mean flow rates will approximate 60,000 and 260,000 cfs in the vicinity of the CGS site. The variations of the river flow in this reach are due not only to seasonal fluctuations, but also to the daily regulation of the power producing Priest Rapids Dam. Flow rates during the late summer, fall and winter may vary from a low of 36,000 cfs to 160,000 cfs each day.

The dependable yield for flows in the Columbia River below Priest Rapids Dam for periods of one year through 10 years, as well as the 30-year period 1929-58 is illustrated in Table 2.4-5. The flow duration curve resulting from a plot of Table 2.4-4 is shown by Figure 2.4-14 (Reference 2.4-20). This figure illustrates the percentage of time equaled or exceeded for different amounts of flows below Priest Rapids Dam on a monthly and on an annual basis.

2.4.11.4 Future Controls Flows in the Columbia River at Hanford are required to be maintained above 36,000 ft3/sec. This is the licensed minimum flow of Priest Rapids Dam and, as such, is a parameter closely monitored and controlled by the Grant County PUD. The State of Washington has administratively set higher average daily minimum flows (greater than 40,000 ft3/sec) and will attempt to have the FERC licenses for the dams modified to insure the minimums (Reference 2.4-21).

COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 LDCN-04-052 2.4-17 2.4.11.5 Plant Requirements All cooling water is supplied to the plant cooling towers via the circulating water system, the plant service water system, or the standby service water system described in Sections 9.2.1.2 and 10.4.5. In the event of an incident rendering the cooling towers inoperative, cooling water is supplied from the spray ponds by the standby service water system, described in Section 9.2.7. These are closed loop systems and the only water loss is through evaporative cooling.

Makeup to the plant cooling towers and spray ponds comes from the Columbia River. Should this capability be lost, the cooling load is taken over by the spray ponds. These ponds have sufficient capacity to provide shutdown cooling water for 30 days without makeup. Other sources of water are available to provide makeup after the initial 30-day period (see Section 9.2.5). Therefore, variation in river flow will not have any adverse affect on the capability to shut down the reactor in a safe and orderly manner.

2.4.11.6 Heat Sink Dependability Requirements At the minimum river flow of 36,000 ft3/sec described in Section 2.4.11.3, there is still sufficient submergence at the makeup water pumps to provide full makeup water requirements at full power operation. Sump level indication and low level alarms are provided in the main control room. Should the sump water elevation fall below the minimum submergence level for the makeup pumps, due either to low river flow or blocked inlets, the plant would be shut down if the situation could not be readily corrected with the safety-related standby service water coming from the spray ponds.

Section 9.2.5 discusses the design bases used in designing the two spray ponds which serve as the ultimate heat sink for CGS. Design of the CGS ultimate heat sink is in compliance with the guidelines presented in Regulatory Guide 1.27 Rev. 1, "Ultimate Heat Sink for Nuclear Power Plants," dated March 1974. The CGS spray ponds serve as the suction source and discharge point for the standby service water system. This system is discussed in Section 9.2.7 and identifies the uses and quantities of water drawn from the ultimate heat sink.

2.4.12 DISPERSION, DILUTION, AND TRAVEL TIMES OF ACCIDENTAL RELEASES OF LIQUID EFFLUENTS IN SURFACE WATERS Small amounts of liquid radioactive wastes, processed within the plant and containing traces of radioactive nuclides, are discharged ultimately to the Columbia River via the plant blowdown line as discussed in Section 11.2.2.2.6 (see Figure 2.4-16). In the vicinity of CGS, the Columbia River is wide, relatively shallow, and fast flowing. Field measurements have shown river velocities near the CGS discharge to be about 3 ft/sec for minimum flows (Reference 2.4-22) and 4.5 ft/sec for average flows (Reference 2.4-23). At the point of discharge the river is about 5 ft deep at minimum flow. Based on a dye dispersion study (Reference 2.4-22), the local eddy diffusivity at low flow has been conservatively estimated to COLUMBIA GENERATING STATION Amendment58 FINAL SAFETY ANALYSIS REPORT December2005 2.4-18 be 4 ft2/sec (Reference 2.4-24). With a combination of minimum river flow and maximum blowdown, it is estimated that an effluent would be diluted by a factor of about 60 at a distance of 300 ft and a factor of 200 at 3000 ft. Dilution factors and travel times for calculating doses to downstream water users are discussed in the CGS Offsite Dose Calculation Manual (ODCM).

Downstream surface water users are listed in Section 2.4.1.2. The travel time to the nearest withdrawal which could be affected by an accidental release is approximately 1 hr. At that point a radioactive release would be essentially completely mixed with the river resulting in a dilution factor of 1:200,000. It is concluded that water users are sufficiently removed from the release point, and the Columbia River is sufficiently dispersive to preclude adverse impacts due to accidental releases. The dispersion characteristics of the river and the effects of routine releases are discussed in Sections 5.1 and 5.2 of the Environmental Report - Operating License Stage.

2.4.13 GROUNDWATER

2.4.13.1 Description and Onsite Use Subsurface soil conditions, across the site, have been classified as follows: a. Loose to medium dense, fine to coarse sand with scattered gravel (glaciofluvial sediments).

b. Very dense, sandy gravel with interbedded sandy and silty layers (Ringold Formation, Middle Member).

c. Very dense, interbedded layers of sandy gravel silt and soft sandstone (Ringold Formation, Lower Member).

d. Basalt bedrock which forms the bedrock beneath the area.

The lithologic character and water bearing properties of the geologic units occurring in the Hanford region are summarized in Table 2.4-6. In general, groundwater in the surficial sediments occurs unconfined, although locally confined zones exist. Water in the basalt bedrock occurs mainly under confined conditions. Occasionally, the lower zone of the Ringold Formation occurs as a confined aquifer, separated from the overlying unconfined aquifer by thick clay beds which possess a distinct hydraulic potential.

The unconfined aquifer consists of both glaciofluvial sand and gravel deposits and the Ringold silts, clays, and gravels. Since these materials are very heterogeneous, often greater lithologic differences occur within a given bed than between beds. In the vicinity of CGS the water table is below the top of the Ringold Formation (see Figures 2.5-64 and 2.5-65). The unconfined COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-19 aquifer bottom is the basalt bedrock in some areas and silt/clay zones of the Ringold Formation in other areas. Clearly the bottom of the unconfined aquifer is not a continuous lithologic surface.

The Hanford Reservation contains over 2200 wells constructed from pre-Hanford work days to the present). Approximately 600 of these wells are used for groundwater monitoring (Reference 2.4-25). Figure 2.4-17 identifies the well locations in the Hanford Reservation as of September 1975. Figure 2.4-18 shows the December 1975 groundwater contour map. In general, the groundwater gradient resulting from groundwater flowing under the Reservation is the highest in the southwestern area toward Rattlesnake Mountain, and slopes toward the Hanford 200 Areas near the center of the reservation. From the 200 Areas the general slope in the gradient is toward northeast and southeast.

A groundwater contour map based on the potential construction of the Ben Franklin Dam at approximately RM 348 is illustrated by Figure 2.4-19. The CGS design basis groundwater level is based on the possible construction of the Ben Franklin Dam and is taken to be 420 ft msl, whereas the most recent study indicates that the water table would be about 405 ft msl (Reference 2.4-26). The feasibility of constructing Ben Franklin Hydroelectric Dam has been extensively studied. Its proposal was strongly contested by local groups and individuals concerned with environmental protection and preservation. Additionally, the matter of the impact such a facility would have on the DOE Hanford Reservation was believed by some to preclude its construction. Finally, the cost/benefit ratio was believed by many to be too low to make the project viable. The combination of the unresolved impediments to the project has effectively, though not conclusively, relegated it to a very low priority status. Planning studies for the project by the Corps of Engineers were suspended in 1969 and reinitiated in October 1979 as part of the development of a management plan for the Hanford reach. The most recent studies were terminated in November 1981.

Impermeable groundwater boundaries are the Rattlesnake Hills, Yakima Ridge, and Umtanum Ridge on the west and southwest sides of the Hanford Reservation. Gable Mountain and Gable Butte also impede the groundwater flow, as well as other small areas of basalt outcrop above the water table. The Yakima River recharges the unconfined aquifer along its reach from horn Rapids to Richland. The Columbia River forms a hydraulic potential boundary which is a discharge boundary for the aquifer. The major source of natural recharge is precipitation on Rattlesnake Hills, Yakima Ridge, and Umtanum Ridge.

Minor changes would be expected in the groundwater elevations during the summer months because of the charging stage of the Columbia River, which historically reaches peak flood stage in June. Because CGS is located about three miles from the river and because of the permeability characteristics and enormous volume of the Ringold Formation, there is a substantial time lag in changing water levels. For the same reasons, the range in water table fluctuations is very small.

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-20 Natural recharge due to precipitation over the lowlands of the Hanford Reservation is not measurable as the evaporation potential during the summer months greatly exceeds total precipitation. Data on migration of moisture from natural precipitation in deep soils (below 30 ft) show movement rates less than 1/2-in./yr at one measurement site (References 2.4-27, 2.4-28 and 2.4-29). The major artificial recharge of ground water to the unconfined aquifer occurs near the Hanford 200 East and 200 West Areas. The large volume of process water (1.35 x 1011 gal) discharged to ground during 1944-1973 has caused the formation of significant groundwater mounds in the water table (Figures 2.4-20 and 2.4-26). Other local groundwater mounds formerly existed along the Columbia River. The present Hanford 100-N Area mound is the only one of these remaining. A minor recharge mound also exists at the Hanford 300 Area.

The unconfined aquifer is characterized by its hydraulic conductivity, the storage coefficient, and the effective porosity. The hydraulic conductivity relates the water flow quantity to the hydraulic potential gradient, while the effective porosity gives the fraction of porous media volume that is available to transmit ground water flow. The storage coefficient relates a change in the water table elevation to a change in the volume of water contained in the aquifer per unit horizontal area. In the limit of no delayed yield, the storage coefficient is equal to the effective porosity of the soil through which the water table moves. These parameters vary widely over the Hanford Reservation.

Qualitatively the hydraulic conductivity, storage coefficient, and effective porosity distributions are a function of the different geologic formations in the unconfined aquifer. Ancestral Columbia River channels which incised in the Ringold Formation are now filled with more permeable glaciofluvial sediments. These channels have been identified extending eastward along the northern and southern flanks of Gable Mountain and extending southeastward from the 200 East Area to the Columbia River (see Figure 2.4-21). These permeable channels are reflected in the groundwater flow pattern of the region.

Quantitative measurements of the hydraulic conductivity of the unconfined aquifer have been made on the Hanford Reservation using a variety of techniques: pumping tests, specific capacity tests, and tracer tests. The most common method has been the pumping tests. Values obtained for the Ringold Formation range between 10 to 650 ft/day with a median of about 130 ft/day. In sharp contrast are the very large hydraulic conductivities of glaciofluvial sediments, ranging from 1,200 to 12,000 ft/day (Reference 2.4-30).

The storage coefficient is much more difficult to measure in the field and estimates are, therefore, less common. For the unconfined aquifer, estimates of the storage coefficient have ranged from 0.01 to 0.1 (Reference 2.4-30). An areal estimate of 0.11 has been provided for the 200 West Area based on the growth of groundwater mounds (References 2.4-30 and 2.4-31). The median specific yield (effective porosity) has been estimated by various researchers at Hanford to range from 4.8% to 11%; most commonly it is assumed to be 10%

(Reference 2.4-32).

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-21 The unconfined groundwater aquifer is characterized by the contour map of the hydraulic potential or water table. The map for December 1975 appears in Figure 2.4-18. The depth to the water table varies greatly from place to place, depending chiefly on local topography which ranges from less than 1 to more than 300 ft below the land surface. Beneath most of the Hanford 200 Area disposal sites the depth of the water table averages about 250 ft. The current estimate of the maximum saturated thickness of the unconfined aquifer is approximately 230 ft.

The chemical quality of the groundwater in the unconfined aquifer is measured at seven locations. Sodium, calcium, and sulfate ions are measured as well as pH. Chromium and fluoride ions associated with fuel manufacturing operations are analyzed from Hanford 300 Area wells. Nitrate ion, which is a waste product from the manufacturing and chemical separation operations, is monitored over the entire Hanford Reservation. Annual maps of the nitrate ion concentration near the surface of the unconfined aquifer are published (Reference 2.4-33). The map showing nitrate concentration for December 1975 appears in Figure 2.4-22.

The radiological status of the groundwater near the surface of the unconfined aquifer is monitored regularly (Reference 2.4-34) and reported annually. Plots of gross beta (ruthenium) plumes and the tritium plumes are shown in Figures 2.4-23 and 2.4-24 for December 1975 (Reference 2.4-33). Since the nitrate ion is not adsorbed in the soil it can be used as a tracer for groundwater movement. The extent of movement of waste water containing radionuclides can thus be plotted. Respective tritium and nitrate ion concentrations under the CGS site are currently ranging from 30 to 300 pci/ml and 4.5 to 45 mg/l depending on the sampling location. Concentration guide for drinking water is 3,000 pci/ml for tritium and the recommended drinking water standard is 10 mg/l for nitrate ions. Gross beta concentrations do not extend to the site.

From the research that has been done to date, it appears that there are a number of confined aquifers underlying the Hanford Reservation. Relatively impermeable confining beds commonly include the individual basalt flows and the silts and clays of the lower part of the Ringold Formation.

Within the basalt sequence, groundwater is transmitted primarily in the interflow zones, either in sedimentary beds or in the scoria and breccia zones forming the tops and bottoms of the flows (References 2.4-35 and 2.4-36). Basalt flows in the Pasco Basin have been eroded particularly in the anticlinal ridges. In some locations the basalts are highly jointed and contain breccia, pillow and plagonite complexes through which groundwater can move. Consequently, hydraulic potential differences between water bearing zones in the upper part of the basalt sequence are small over hundreds of feet of depth. The lowermost Ringold Formation silts and clays are of variable thickness. Distinct hydraulic potential differences have been observed between aquifers below the silts and clays and the unconfined aquifer.

COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-22 Groundwater flow in the uppermost confined aquifer is also to the southeast with possible discharge into the Columbia River somewhere below Lake Wallula. However, the flow rates are regarded as quite small due to the low transmissivity range of this water bearing zone. Groundwater in the lower confined aquifers does not appear to cross the major anticlinal divides that define the Pasco Basin.

The piezometric or hydraulic potential map for the confined zones above the basalt (Figure 2.4-25) was based on measurements made in 1970. In general, the hydraulic potential observed in the confined aquifer zones above the basalt is greater than in the overlying unconfined aquifer. The main exception is in the vicinity of the Hanford 200 Area recharge mounds which have raised the potential in the unconfined aquifer.

One recharge area that has been identified is from the Yakima River at Horn Rapids. The piezometric map in Figure 2.4-25 also suggests recharge from the upper Cold Creek Valley with flow toward a potential trough under the Columbia River. The Columbia Basin Irrigation Project to the northeast and east, and the Columbia River behind Priest Rapids and Wanapum Dams to the northwest are other probable recharge sites in both these areas the basalt is exposed and is covered by perennially saturated unconsolidated deposits. A site of possible minor recharge exists adjacent to Gable Butte and Gable Mountain anticline near the center of the Reservation.

Only 90 wells on the Hanford Reservation have been drilled to basalt. Thus data on the confined aquifers in the basalt flows are limited and more would have to be gathered to fully characterize the confined aquifers.

The plant is located on glaciofluvial outwash sands and gravels which are about 50 ft thick. Below this layer occurs very dense gravel. Sandy gravel occurs in a sequence approximately 200 ft thick which is assumed to be the middle member of the Ringold Formation. The lower member of the Ringold Formation consists of a very compact, interbedded gravel, sand, silt, and clay and extends down to a depth of about 500-525 ft. Basaltic bedrock underlies the lower Ringold member, at approximately 550 ft depth.

The water table is about 60 ft below the ground surface level at CGS. The water table elevation is about 378 +4 ft msl and appears to be stable. The effective bottom of the unconfined aquifer is assumed to be at about 220-260 ft msl at the top of the lower Ringold Formation. Groundwater potentials from the lower Ringold and from the basalt water bearing zones are about 25 ft higher than that of the unconfined aquifer. Test borings down to 925 ft reveal there are water bearing zones in the lower basalt flows and sedimentary interbeds at CGS. Piezometric level in basalt is 10 ft above unconfined water table and hence artesian.

Under the CGS site the unconfined groundwater is moving easterly toward the Columbia River, the nearest discharge boundary. Studies of the uppermost confined aquifer indicate that the COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-23 potential gradients at the proposed site are oriented in the same general direct ion as those of the unconfined aquifer.

Three water supply wells are located on the site. Two shallow wells were constructed in the unconfined aquifer (at approximately 240 ft deep) and a third well penetrates a confined aquifer in the underlying basalt flows (at approximately 695 ft deep). Normal water supply is from the river, and the deep well is maintained in the standby mode to provide supplemental makeup water for the potable and demineralized water system as needed. Pumping capability is about 250 gpm. The two shallow wells were used during construction.

2.4.13.2 Sources Regional use of the unconfined aquifer occurs at two nearby locations. The first is at the DOE's 400 Area located about 3 miles southwest of the CGS site as shown in Figure 2.1-3. Groundwater to this construction site is supplied from two wells and is used for sanitary and operation purposes. Maximum expected usage rate is between 2 million and 2.5 million gal/month. No data is available on drawdown tests performed on the FFTF water supply wells 699-SO-7 and SO-8. The second location of ground water use is the WNP-1/4 site about 1 mile east of CGS. Water is drawn from two wells for sanitary and potable water requirements. Usage rate is approximately 250,000 gal/month.

The two onsite wells which drew from the unconfined aquifer (699-13-1A and 1B) are 234 and 244 ft deep. Drawdown tests for each well showed 22 and 91 ft of drawdown respectively, at pumping rates of 250 gpm and test durations of about 25 hr. These wells are no longer used. The third well (695 ft deep) is sealed from the unconfined aquifer and draws from confined water in the basalt. Drawdown on this well was 163 ft at a pumping rate of 275 gpm with a test duration of 25 hr.

Water table contours in the vicinity of CGS can be seen in Figure 2.4-26. The aquifer is assumed to be isotropic, therefore, flow occurs along instantaneous streamlines perpendicular to the equipotential contours. The groundwater flow is toward the discharge boundary at the Columbia River to the east of the site. The hydraulic potential gradient in this area is about 8-10 ft/mile in the unconfined aquifer. As described in Section 2.4.13.1, recharge and discharge of riverbank storage occur along the Columbia River with daily fluctuations superimposed on the seasonal variations in river stage. Hydrographs of wells in the vicinity of the plant site (Figure 2.4-27) show that riverbank storage is not detectable even in years of extreme spring runoff at the two wells that are about one mile from the riverbank. Thus no seasonal reversability of the gradients driving the groundwater flow occurs. In other areas of the Hanford Reservation, the seasonal fluctuations of groundwater levels from riverbank recharge can be detected 3-4 miles inland from the riverbank.

During early studies of groundwater in the area (References 2.4-37 and 2.4-31) little information was obtained on specific features at the plant site. The water table for 1944 COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-24 (pre-Hanford Work conditions) was interpolated using 1948-1952 observation well data (Figure 2.4-20) and showed a water table elevation of about 370 ft msl under the site. The potential gradient was interpolated (References 2.4-31 and 2.4-38) to be about 5-6 ft per mile toward the Columbia River. The earliest wells in the vicinity (699-2-3 and 17-5) were drilled in 1950. Their hydrographs, presented in Figure 2.4-27, show the gradual rise of the water table to approximately 15 ft above pre-Hanford Operations elevations. The peak rise in 1972 for well 699-2-3 shown on Figure 2.4-27 is believed to be a measurement error. Other wells were drilled in 1958, 1961, 1962 and 1966. Their hydrographs appear in Figure 2.4-27. Wells 669-14-E6-T and E5T also show the gradual rise of the water table at their respective locations. Smaller apparent water table changes at the site between 1944- 1974 (see 2.4.13.1 and Figure 2.4-27, well 699-14-E6-T and 699-20-E5-T) indicated a zone of relatively lower hydraulic conductivity in this area.

Well 699-9-E2 is a deep well perforated in both the unconfined and lower confined aquifer zones. Its historical hydrograph (Figure 2.4-27) reflects a composite of confined and unconfined potentials with discontinuities caused by sanding in an subsequent maintenance operations. The 1962 peak of the hydrograph of well 699-20-E12 (Figure 2.4-27) is due to the influence of the high confined aquifer potential before the installation of piezometer tubes in this deep well. The 1972 peak, could be bank recharge from the high river stage of that year but the lack of previous response to river stage makes the measurement suspicious. Well 699-10-E12, also located within one mile of the river, does not show seasonal bank recharge (Figure 2.4-27). Over the past two years, a decrease in the rate of rise is evident.

Soil test borings and water supply wells drilled in conjunction with the CGS construction site, confirmed the present contouring interpretation of the water table. Recent data from boring at WNP-1 and WNP-4 are not reflected in the water table maps shown in Figures 2.4-18, 2.4-19, 2.4-26, and 2.4-25.

The historical well hydrographs for the uppermost confined aquifer in the vicinity of the plant site are given in Figure 2.4-27. Well number 699-20-E12-P shows a rather rapid rise of the confined aquifer potential in 1962-65. It has been postulated that this rise reflects recharge to the confined zones from irrigation across the river in the Columbia Basin Irrigation Project. The hydraulic potential in the uppermost confined aquifer near the plant site is presently about 390 ft msl, which is about 25 ft higher than the potential of the overlying unconfined aquifer.

The effects of the groundwater withdrawal at the site have been estimated to be local. No drawdown has been detected in the nearest observation wells, numbers 699-17-5 and 699-9-E2. The latter well is perforated over multiple aquifers so it does not give a representative measurement of the water table elevation. The radius of influence (defined to be the radius at which a 0.1 ft drawdown exists) of the CGS wells has been estimated to be about 3500-4500 ft. This is based on the ten months of high rate of withdrawal during compaction COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 2.4-25 operations taking into account the ambient water table gradient. The subsequent reduction in withdrawal flow rate to 25% of the early value would shrink the radius of influence considerably.

There is no groundwater recharge area within the influence of the plant. The 60-ft depth from the land surface to the water table and the arid condition of sediments above the water table make it virtually impossible to detect any recharge from precipitation over this area.

2.4.13.3 Accidental Effects An evaluation of a possible radioactive liquid release is postulated due to the rupture of a 700-gal decontamination solution concentrator waste tank within the radwaste building (see Figure 11.2-1). The released effluent was then assumed to reach the soil environment outside the building and to percolate to the water table unimpeded. On entering the groundwater, the postulated radwaste release is dispersed, sorbed, decayed, and diluted along the potential groundwater pathway from the plant towards the Columbia River.

In the unconfined (water table) aquifer, there are no down gradient groundwater users between CGS and the Columbia River. However, the construction water needs at WNP-1/4 are supplied by the two deep wells that withdraw groundwater from the uppermost confined aquifer downgradient from the CGS radwaste building. During operation of WNP-1/4, these wells will be maintained in a standby mode. The uppermost screens in these wells are about 240 ft below the ground surface in the lower Ringold Formation. The effective bottom of the unconfined aquifer is generally assumed to be at the top of the lower Ringold Formation or about 200 ft below the surface. Thus, in all likelihood, any liquid radioactive spill to the groundwater beneath the CGS radwaste building would travel through the unconfined aquifer towards the Columbia River. However, for conservatism, analyses of postulated radionuclide movement assume that the WNP-1/4 wells draw from the unconfined aquifer. The remainder of this subsection provides estimates of travel times of critical radionuclides to move from the postulated spill to receptors and the corresponding concentration reduction factors.

For an assumed one-dimensional groundwater movement, the groundwater travel time, t, is the path length, L, divided by the groundwater velocity (seepage velocity), u. The groundwater velocity is the Darcy (apparent) velocity divided by the effective porosity, u = Ki/ne, where K is the lateral permeability (hydraulic conductivity) of the aquifer, i is the hydraulic gradient, and ne is the effective porosity of the aquifer material.

For computational purposes, a conservative value for lateral permeability of 500 ft/day was selected to represent the unconfined aquifer located in the Ringold Formation beneath CGS (see Figure 2.4-21). From 2.4.13.1, effective porosity is taken 0.10. From Figure 2.4-26, the gradient in the water table aquifer between the plant and the Columbia River is about 8 or 9 ft/mile, and is taken conservatively as 10 ft/mile.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-26 Using the above parameter values, groundwater velocities were computed to be 10 ft/day. With path lengths of 3.4 miles to the river and 1.0 mile to the WNP-1/4 wells, the respective travel times are estimated to be 5.2 years and 1.5 years. Generally, the critical radionuclides of concern for a postulated liquid radwaste spill are 3H, 90Sr, and 137Cs. These three radionuclides are fairly representative in terms of sorption characteristics, of those found in liquid radwaste tanks, since tritium does not sorb onto soil particles at all, strontium is an intermediate sorber, and cesium strongly sorbs to soil particles. The half-life of tritium is 12.3 years, whereas those of 90Sr and 137Cs are 29.0 and 30.1 years, respectively.

The travel time, ti, for a particular radionuclide moving through groundwater depends upon the velocity, ui, of the radionuclide ti = l/ui where the radionuclide velocity is ui = rfu in which rf is the velocity reduction factor attributable to sorption r = 1/1+bn kfd In this equation, b is the bulk density of the aquifer material, n is the total porosity, and Kd is the equilibrium distribution coefficient for a particular radionuclide. The bulk density and total porosity are further related physically as b = Rs (1 - n) where Rs is the real specific gravity or particle density of the solid particles in the aquifer media. The particle density, Rs, for Hanford soils is usually taken to be constant at 2.65 gm/cm3, (Reference 2.4-39). The bulk density b, of Hanford soils has been determined to range from about 1.5 gm/cm3 to about 1.75 gm/cm3, with a median value of about 1.65 gm/cm3, (Reference 2.4-40). For the median value of bulk density, the corresponding total porosity is about 0.377.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-27 Using the above value for bulk density and total porosity, radionuclide travel time, ti, through the groundwater beneath WNP-1/4 can be expressed as ti = (1 + 4.4 Kd) t The following summarizes radionuclide travel times (in years) to the WNP-1/4 wells (1.0 miles) and to the Columbia River (3.4 miles):

Nuclide Half-life, years Kd ti @ 1.0 miles ti @ 3.4 miles 3H 12.3 0 1.5 5.2 90Sr 29.0 10 67.0 230.0 137Cs 30.1 100 660.0 2300.0 The radionuclide concentration at the point of water use will be determined by the amount of decay, dispersion, and sorption on the aquifer media. The minimum concentration reduction factor, CRFmin, along the centerline of the contaminant plume from an instantaneous point source is given by (Reference 2.4-41) CRF = CC (KKK)2Vminoxyz1/2()/432t for an effluent volume, V, with a specific gravity of 1.0 and an initial concentration, Co, released to soil with dispersion coefficients, Kx, Ky, Kz, in the x, y, and z directions, respectively. This expression neglects the phenomena of sorption and decay which will be considered later.

It is generally accepted that the dispersion coefficients are proportional to groundwater velocity for unidirectional flow, i.e.,

Kuxyzxyz,,,, = where x,y,z, are constants called dispersivities which are a function of the nonhomogeneity of the material. The range in dispersivities in homogeneous granular aquifers may approach 1000 cm (33 ft) (Reference 2.4-42). Substituting this relationship into the above expression for concentration reduction, and noting that travel time is determined by path length and velocity, results in CRFmin = (4L) ()2V3/2xyz1/2 For the conservative condition of x = y = z = 1.0, then COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-28 CRF = (4 L)2Vmin3/2 The concentration reduction factors at the WNP-1/4 wells and at the bank of the Columbia River, due only to dispersion, are 9.1 x 104 and 5.7 x 105, respectively, for the 700-gal concentrated waste tank. When sorption and decay are included, the concentration reduction is given by (Reference 2.4-42) CRF = (4 L)3 / 2 ( )xyz1/22V e ti in which is the radionuclide decay constant defined in terms of the half-life, T1/2, of a particular radionuclide as = 1n 2T1/2 The concentration reduction factor can be expressed as CRF = CRF (e t )min i The exponential term accounts for the effects of sorption and decay. The only effect of sorption on concentration reduction is to increase the travel time, thus allowing more time for decay. Concentration reduction factors (CRF) for the radionuclides listed were calculated for path lengths of 1.0 mile (to WNP-1/4 wells) and 3.4 miles (to Columbia River):

Nuclide CRF (1.0 mile) CRF (3.4 mile) 3H 1.0 x 105 7.7 x 105 90Sr 4.5 x 105 1.8 x 108 137Cs 3.7 x 1011 5.8 x 1928 The above factors, derived through the application of conservative parameters, are used in Section 15.7.3 to evaluate concentrations offsite. The consideration of the WNP-1/4 wells is especially conservative. Groundwater contamination from the 200 Areas which reached CGS over six years ago (see Section 2.4.13.1) has not been detected at WNP-1/4. This substantiates that the WNP-1/4 wells do not draw from the unconfined aquifer or, alternatively, the hydraulic conductivities are much less than assumed.

COLUMBIA GENERATING STATION Amendment 63 FINAL SAFETY ANALYSIS REPORT December 2015 LDCN-13-050 2.4-29 It should also be noted that if Ben Franklin Dam were ever constructed, the concentration reduction factors at the river bank would be even larger than those noted above. This would be true, because the groundwater gradient (thus, the groundwater velocity) would be decreased as shown in Figure 2.4-19.

2.4.13.4 Monitoring or Safeguard Requirements Plant water systems result in releases to the ground at a number of locations. Sanitary wastewater is routed to a central treatment system comprised of lined aeration lagoons and stabilization ponds. This treatment plant also receives wastes from the Plant Support Facility, WNP-1 and WNP-4, and the DOE's 400 Area. Periodically the treated effluent is discharged to percolation beds.

As discussed in Section 2.4.2.3, the storm water drainage system discharges to lined ponds northeast of the plant (see additional description in Section 9.3.3.2.3.1). Such sources as water treatment filter backwashes, heating, ventilating, and air conditioning (HVAC) air wash units, and some building sumps and floor drains (see Section 9.3.3.2.3) also contribute to flow in the storm water system. Periodic testing and flushing of the fire protection system and cleaning of the cooling towers and standby service water ponds result in localized discharges of water to the ground.

Monitoring of groundwater and plant-related discharges to ground is performed as described in the ODCM.

2.4.13.5 Design Bases for Subsurface Hydrostatic Loadings CGS does not employ permanent dewatering systems. Site groundwater conditions are presented in Section 2.5.4.6 and the design bases for subsurface hydrostatic loadings are given in Section 3.4.

The design-basis groundwater elevation used for subsurface hydrostatic loadings is 420 ft msl and was predicated on the possible future construction of Ben Franklin Dam at RM 348. As noted in Section 2.4.13.1, planning for the dam has been terminated. The same section notes that the water table beneath CGS would rise to less than 405 ft msl if the dam were to be completed. The actual water table beneath the project is about 385 ft msl (see Sections 2.4.13.1 and 2.5.4.6). The design-basis groundwater level is adequate to account for seepage from the ultimate heat sink spray ponds or the rupture of any Seismic Category I or nonseismic pipe. As discussed in Section 3.8.4.1.5, the two, 250-ft2 reinforced-concrete spray ponds are designed to Seismic Category I requirements and are designed to mitigate any possible water leakage. The bottom of the spray ponds are at 417 ft msl and the ponds are designed for external hydrostatic loading to 420 ft msl. The maximum combined leakage from the two ponds during the initial filling sequences was 120 gpm. It may be inferred from previous studies (Reference 2.4-7) that continued leakage cannot affect the groundwater level COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-30 beneath the ponds or other safety-related structures, the closest of which (500+ ft away) is the diesel generator building with a foundation at 434 ft msl. These early CGS hydrologic studies evaluated the effect of cooling pond leakage and cooling tower blowdown at the project site. Equivalent leakage/discharge rates used in these studies were very much greater than leakage from the spray ponds. For example, the continuous discharge of 2700 gpm of cooling tower blowdown to the depression just east of CGS was estimated to raise the water table about 20 ft beneath the point of discharge (Reference 2.4-7). Based on these previous studies, it can be concluded that the minimal amount of spray pond leakage will have no influence on the design-basis groundwater elevation of 420 ft msl. With respect to a pipe break, the 144-in. circulating water system pipe on the discharge side of the condenser would produce the maximum release of water. The maximum quantity of water released from such a rupture is 199,180 ft3. This discharge would have a negligible (less than 1 in.) and temporary effect on the groundwater level. Failure of the pipe at its closest proximity to a safety-related building may result in temporary saturation of the backfill. This material has been recompacted to a minimum relative density of 75% and an average relative density of 85%. As discussed in Section 2.5.4.8, these densities are not susceptible to liquefaction for motions associated with the safe shutdown earthquake, and as discussed in Section 2.5.4.10, temporary saturation would not significantly reduce the bearing capacity of the densely compacted backfill. A continuous but undetected leak from any major pipe would not influence the groundwater level enough to affect plant structures. This may be deduced from the time factors and water table rises predicted from a number of scenarios in the above mentioned hydrologic studies (Reference 2.4-7).

2.4.14 TECHNICAL SPECIFICATIONS AND EMERGENCY OPERATION REQUIREMENTS The worst hydrological condition, as discussed in this section, is a flood caused by a postulated PMP event. This flood does not create an adverse hydrological condition on safety-related equipment. Emergency flood protection procedures are therefore unnecessary.

2.4.15 REFERENCES

2.4-1 Woods, V. W., "A Summary of Columbia River Hydrographic Information Pertinent to Hanford Works - 1894 to 1954," HW-30347, February 24, 1954.

2.4-2 Memorandum Report Columbia River Basin Lower Columbia River Standard Project Flood and Probable Maximum Flood, U.S. Army Engineers, North Pacific Division, Portland, OR, September 1969.

2.4-3 "Probable Maximum Precipitation," Hydrometeorological Report No. 43, U.S. Weather Bureau (now NOAA), Northwest States, 1966.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-31 2.4-4 Corps of Engineers, North Pacific Division, letter to V. C. St. Clair, Atomic Energy Commission, Richland Office, November 2, 1970. 2.4-5 Corps of Engineers, North Pacific Division, letter to M. J. Hroncich, Burns and Roe Inc., February 7, 1972.

2.4-6 Corps of Engineers, North Pacific Division, letter to M. J. Hroncich, Burns and Roe Inc., February 14, 1972. 2.4-7 Final Report on Hydrology Studies of the WNP-2 Site, July 1971, and Addendum I to Final Report on Hydrology Studies of the WNP-2 Site, by Battelle Northwest, Richland, WA, to Burns and Roe Inc., July 1971. 2.4-8 Design of Small Dams, U.S. Bureau of Reclamation, 1977.

2.4-9 "Water Surface Profiles," Vol. 6 Hydrologic Engineering Methods for Water Resources Development, U.S. Army Corps of Engineers, Hydrologic Engineering Center, July 1975.

2.4-10 Shore Protection Manual, U.S. Army Corps of Engineers, Coastal Engineering Research Center, 1975.

2.4-11 "Wave Runup and Wind Setup on Reservoir Embankments," Engineering Technical Letter No. 1110-2-221, Department of the Army, Corps of Engineers, November 29, 1976.

2.4-12 Artificial Flood Possibilities on the Columbia River, Corps of Engineers, Washington District, Washington, DC, November 20, 1951.

2.4-13 Rockwood, D. M, letter to R. Chitwood, "Preliminary Estimate of Upstream Dam Failure Effects," June 21, 1972.

2.4-14 Arthur, H. G., letter to J. J. Stein, "Behavior of Grand Coulee Dam and Forebay Dam When Subjected to Overtopping," August 1, 1972. 2.4-15 Artificial Flood Considerations for Columbia River Dams, Corps of Engineers, U.S. Army Engineer District, Seattle, WA, August 1963. 2.4-16 Eugene Isaacson, Calculations of Severe Floods in a Developed River, January 1965.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-32 2.4-17 Artificial Flood Considerations for Columbia River Below Chief Joseph Dam to Richland, Washington, U.S. Army, Corps of Engineers North Pacific Division, Portland, OR, January 1968. 2.4-18 Safety Evaluation by the Division of Reactor Licensing, U.S. Atomic Energy Commission in the matter of Portland General Electric Company, Pacific Power and Light Company, City of Eugene, OR, Trojan Nuclear Plant, Docket No. 50-344, pp. 11-12. 2.4-19 Jaske, R. T., and Synoground, M. O., "Effect of Hanford Plant Operation on the Temperature of the Columbia River, 1964-Present," BNWL-1345, Battelle, Pacific Northwest Laboratories, Richland, WA, November 1970. 2.4-20 "Columbia North Pacific Region Water Resources Appendix V," Volume 1, March 1969.

2.4-21 Columbia River Instream Resource Protection Program, Department of Ecology, Olympia, WA, June 1980, pp. 61-67.

2.4-22 Vertical Mixing Characteristics of the Columbia River at RM 351.75, WNP No. 2, Battelle Pacific Laboratories, Richland, WA, March 16, 1972.

2.4-23 Preoperational Environmental Monitoring Studies Near WNP-1, 2, and 4 August 1978 Through March 1980, WPPSS Columbia River Ecology Studies Vol. 7, Beack Consultants, Inc., Portland, OR, June 1980.

2.4-24 Kannberg, L. D., Mathematical Modeling of the WNP-1/2/4 Cooling Tower Blowdown Plumes, Battelle Pacific Northwest Laboratories, Richland, WA, March 1980.

2.4-25 McGhan, V. L., and Damschen, D. W., Hanford Wells, PNL-2894, Battelle Pacific Northwest Laboratories, Richland, WA, May 1979.

2.4-26 Harty, Harold, "The Effects of Ben Franklin Dam on the Hanford Site," PNL-2821, Battelle, Pacific Northwest Laboratories, Richland, WA, April 1979.

2.4-27 Bierschenk, W. H., "Aquifer Characteristics and Ground Water Movement at Hanford," HW-60601, June 9, 1959.

2.4-28 Bierschenk, W. H., "Hydraulic Characteristics of Hanford Aquifers," HW-48916, March 3, 1957.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-33 2.4-29 Honstead, J. F., McConiga, M. W., and Raymond, J. R., "Gable Mountain Ground Water Tests," HW-34532, January 21, 1955. 2.4-30 Gephart, R. E., Spane, F. A., Leonhart, L. S., Palombo, D. A., Strait, S. R., "Pasco Basin Hydrology", Hydrologic Studies within the Columbia Plateau, Washington - An Integration of Current Knowledge, (RNO-BWI-ST-5), by Rockwell Hanford Operations, Richland, WA, October 1979.

2.4-31 Newcomb, R. C., Strand, J. R. and Frank, F. J., "Geology and Ground Water Characteristics of the Hanford Reservation of the U.S. Atomic Energy Commission," Professional Paper # 717, USGS., Washington, 1972.

2.4-32 Cole, C. R., and Reisenauer, A. E., "Variable Thickness Transient Model Assumptions and Boundary Conditions," Battelle Pacific Northwest Laboratories, Richland, WA, August 1974.

2.4-33 Environmental Monitoring Report on the Status of Groundwater Beneath the Hanford Site, January- December 1975, BNWL-2034, Battelle, Pacific Northwest Laboratories, Richland, WA, January 1977.

2.4-34 Bramson, O. P. E., and Corley, J. P., "Hanford Environmental Surveillance Routine Program," Master Schedule -CY 1973, BNWL-B-234, Battelle, Pacific Northwest Laboratories, Richland, WA, December 1972.

2.4-35 Newcomb, R. C., "Some Preliminary Notes on Ground Water in the Columbia Basalt," Northwest Sciences, Vol. 33, 1, 1959, pp. 1-18.

2.4-36 LaSala, A. M., Jr., Doty, G. C., and Pearson, F. S., "A Preliminary Evaluation of Regional Ground Water Flow in South-Central Washington," USGS Open File Report, January 1973.

2.4-37 Parker, G. G., and Piper, A. M., "Geologic and Hydrologic Features of the Richland Area, WA, Relevant to Disposal of Waste at the Hanford -Directed Operations of the Atomic Energy Commission," Interior Report 1, USGS Report to Atomic Energy Commission, 101 pages, 5 Illus., 1949.

2.4-38 Kipp, K. L., and Mudd, R. D., "Selected Water Table Contour Maps for the Well Hydrographs and Hanford Reservation, 1944-1973," BNWL-1797, Battelle, Pacific Northwest Laboratories, Richland, WA.

2.4-39 Serne, R. J., Routson, R. C., and Cochran, D. A., "Experimental Methods for Obtaining PERCOL Model Input and Verification Data," BNWL-1721, Battelle Pacific Northwest Laboratories, Richland, WA, 1973, p. 24.

COLUMBIA GENERATING STATION Amendment 57 FINAL SAFETY ANALYSIS REPORT December 2003 2.4-34 2.4-40 Rouston, R. C., and Serne, R. J., "Experimental Support Studies for the PERCOL and Transport Models," BNWL-1719, Battelle Pacific Northwest Laboratories, Richland, WA, 1972, pp. 37, B-1, and B-2.

2.4-41 Carslaw, H. S., and Jaeger, J. C., Conduction of Heat in Solids, Oxford University Press, London, England, 1959.

2.4-42 Codell, R. B., and Schreiher, D. L., "NRC Models for Evaluating the Transport of Radionuclides in Groundwater," Proceedings of the Symposium on Management of Low Level Radioactive Waste, Pergamon Press, 1979, pp. 1193-1212.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-35 Table 2.4-1 Major Columbia River Basin Dams Location Dams River River Miles from Site Usable Storage 103 ac-ft Upstream Mica Columbia (Can) 666 12,000 Duncan Duncan 1,400 Arrow Columbia (Can) 429 7,090 Libby Kootenai 642 5,000 Hungry Horse South Fork Flathead 3,160 Kerr Clark Fork 1,219 Albeni Falls Pend Oreille 483 1,153 Grand Coulee Columbia 245 5,200 Chief Joseph Columbia 193 -- Wells Columbia 164 117 Chelan Chelan 152 677 Rocky Reach Columbia 122 120 Rock Island Columbia 101 -- Wanapum Columbia 64 389a Priest Rapids Columbia 45 170a Downstream McNary Columbia 60 John Day Columbia 136 The Dalles Columbia 160 Bonneville Columbia 206 a Storage not available for flood regulation.

COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-36 Table 2.4-2 Columbia River Temperatures Near Columbia Generating Station MONTHLY AVERAGE WATER TEMPERATURE, IN C, AT RICHLAND, WA Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Average 1965 6.1 5.4 6.3 9.1 11.0 14.2 17.3 19.8 18.5 16.4 12.6 8.4 12.1 1966 6.9 6.2 6.8 10.3 12.1 13.5 16.2 18.8 19.4 15.6 12.6 9.5 12.2 1967 7.4 7.0 6.6 8.8 12.0 13.9 17.0 20.2 19.4 16.1 12.0 7.8 12.4 1968 5.7 5.0 6.0 8.8 12.8 14.3 17.0 18.7 18.3 15.0 11.4 7.4 11.7 1969 2.7 1.9 4.3 8.0 11.4 15.3 17.9 19.3 18.6 15.2 11.7 7.0 11.1 1970 5.3 4.9 5.7 7.9 11.7 15.4 19.0 19.9 17.5 14.9 10.6 5.9 11.6 1971 4.2 3.4 3.8 7.0 11.1 12.9 16.4 19.5 17.8 15.0 10.7 6.2 10.7 1972 3.3 2.2 3.7 7.0 11.0 13.3 15.5 18.1 16.9 14.0 10.5 6.1 10.1 1973 3.2 3.0 4.7 7.8 12.9 15.6 18.3 19.6 18.3 15.0 9.9 7.6 11.3 1974 3.2 3.2 5.2 8.2 11.3 13.7 17.4 19.4 18.8 15.4 11.5 7.9 11.3 Average 1965-1974 4.7 4.2 5.3 8.3 11.7 14.2 17.2 19.3 18.4 15.3 11.4 7.4 11.4 Minimum Daily 0.2 0.7 2.4 5.1 8.6 11.2 14.2 17.3 14.6 11.1 7.7 2.4 -- Maximum Daily 8.3 8.3 8.6 12.8 15.0 17.7 20.4 21.5 21.1 18.5 15.9 11.3 -- Records since June 1964. MONTHLY AVERAGE WATER TEMPERATURE, IN C, AT PRIEST RAPIDS DAM, WA 1961 5.4 4.7 4.7 7.4 10.4 13.7 17.3 18.9 17.8 14.9 10.4 6.6 11.0 1962 4.1 3.6 3.6 6.5 10.0 13.7 16.1 17.4 17.1 14.8 11.9 8.9 10.6 1963 5.3 3.8 4.6 6.5 10.4 14.0 16.6 18.4 18.3 16.3 11.9 7.7 11.2 1964 5.5 4.6 4.7 7.2 9.7 12.8 15.3 17.1 16.3 14.6 10.8 6.3 10.4 1965 4.4 3.3 4.1 6.6 10.0 13.3 16.1 18.4 17.3 15.3 11.9 7.8 10.7 1966 4.8 4.1 4.5 7.8 10.6 12.4 15.3 17.5 17.5 14.6 11.6 8.4 10.8 1967 5.9 5.7 5.0 6.8 10.1 13.3 16.1 18.5 18.2 15.4 11.3 7.2 11.1 1968 4.6 3.3 4.6 7.1 11.1 13.4 16.1 17.5 17.2 14.2 10.9 6.8 10.6 1969 2.4 1.5 3.4 7.2 10.8 14.6 17.1 18.2 17.7 14.8 11.5 7.6 10.6 1970 4.3 4.1 4.8 6.8 10.9 14.8 18.0 19.2 17.5 15.2 10.6 6.2 11.0 1971 4.0 3.5 3.6 6.6 10.7 12.6 15.3 18.4 17.2 15.2 11.3 6.8 10.4 1972 3.6 1.9 4.0 7.2 10.6 12.9 15.2 17.3 16.8 15.4 11.3 7.3 10.3 1973 2.3 2.9 4.8 7.7 12.5 15.4 17.6 18.8 17.8 15.2 10.3 7.7 11.1 1974 4.0 3.0 4.9 7.7 10.8 13.6 17.2 18.7 18.4 15.5 11.8 8.6 11.2 Average 1965-1974 4.0 3.3 4.4 7.2 10.8 13.6 16.4 18.3 17.6 15.1 11.3 7.4 10.8 Minimum Daily 0.3 0.3 2.2 4.3 7.5 10.6 13.1 16.6 15.3 12.2 7.7 2.3 -- Maximum Daily 7.6 6.2 6.9 10.1 14.6 17.1 19.3 20.2 20.0 18.7 14.4 10.5 -- Records since August 1960. Recorded values adjusted by computer-simulation to compensate for measurement errors and missing data.

COLUMBIA GENERATING STATION Amendment 55 FINAL SAFETY ANALYSIS REPORT May 2001 LDCN-00-000 2.4-37 Table 2.4-3 Downstream Surface Water Users Location of Diversion Approximate Miles Quantity Type Name Township Range Section Downstream (cfs) Usea Energy Northwest 11 28 2 -- 90 IN Peter Kewit and Sons 11 28 2 -- 1 I L. L. Bailey 11 28 24 4 2 I H. D. Loyd 11 28 24 4 0.99 D,I Central Premix Concrete Company 11 28 27 4 2 IN Battelle Memorial Institute 10 28 14 8 4.4 I University of Washington 10 28 23 9 1.75 I City of Richland 10 28 24 9 0.67 D City of Richland 10 28 25 12 31 D City of Richland 10 28 25 12 23.25 D City of Richland 10 28 25 12 31 D City of Richland 10 28 35 12 93 D E. C. Watts 9 28 1 13 0.31 D,I H. S. Petty 9 28 1 13 0.48 I N. H. and M. E. Ketchersid 9 28 1 13 1.66 I G. C. Walkley 9 28 1 13 2.32 I R. T. Justesen, et al. 9 28 12 15 2.54 I Central Premix Concrete Company 9 28 12 15 1.10 IN City of Richland 9 28 13 17 2.0 I Benton County 9 29 28 19 1.0 I City of Kennewick 9 30 31 23 55.7 D City of Pasco 9 30 31 23 35.0 D F. J. Henckel 8 30 14 27 0.015 I Allied Chemical 8 30 14 27 3.55 IN Chevron Chemical 8 30 23 28 3.77 IN Chevron Chemical 8 30 23 28 40 IN Phillips Pacific Chemical Company 8 30 24 28 82 IN Phillips Pacific Chemical Company 8 30 24 28 20 IN Boise Cascade Corporation 7 31 10 34 24.5 IN L. D. Hoyte, et al. 7 31 14 35 179.8 I D. Howe 7 31 23 36 6.4 I Crawford and Sons 6 30 27 47 32.8 I Barbarosa Farms 6 30 27 47 20 I Crawford and Sons 6 30 27 47 7.6 I Rainier National Bank 6 30 27 47 9.4 I Anderson and Coffin 5 29 5 49 242 I Horse Heaven Farms 5 29 6 50 82 I Horse Heaven Farms 5 29 6 50 550 I Horse Heaven Farms 5 29 6 50 290 I Anderson and Coffin 5 29 6 50 242 I a D - Domestic or municipal uses I - Irrigation and other agricultural uses IN - Industrial Includes only those water rights for which a permit or certificate has been issued COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-38 Table 2.4-4 Mean Discharges in CFS of Columbia River Below Priest Rapids Dam, Modified to 1970 Conditions Water Year Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. Annual 1928 224000 109900 90900 1929 82300 78400 101100 103000 108000 72600 85200 62000 71300 87600 97000 94300 86900 1930 87900 89800 102700 93500 90700 83100 72500 81700 90200 98800 97600 92700 90100 1931 86800 89600 100000 82200 90800 88400 74500 81700 104000 102200 99400 85800 90400 1932 87400 88700 102000 95000 109200 77800 90700 157500 156700 74600 97800 90600 102300 1933 89600 69700 102700 128800 167100 97900 118900 185900 196600 180300 121900 100200 130000 1934 100600 104200 128000 139600 203400 196700 243100 221200 168800 104500 100000 101000 150900 1935 82000 72400 109200 132100 132000 111300 117600 147500 156900 131100 99300 96900 115700 1936 90200 86200 107900 119400 79800 80400 81500 160500 123300 83400 93200 89400 99600 1937 87600 87500 105400 96600 100600 84400 63500 70400 76900 87800 102500 91500 87900 1938 89300 83100 88700 111000 124100 86800 110700 142400 146800 154100 90400 89200 109700 1939 83400 77100 91700 127200 90400 83000 108500 100000 112400 95500 96900 90800 96400 1940 85800 85400 90500 133200 98000 89200 110700 89700 101700 94100 96000 91600 97200 1941 84300 79600 92500 99400 92200 87900 137400 76900 73200 84000 91500 88700 90600 1942 96000 82700 91400 114100 119000 84600 115900 105300 148400 101400 102000 88300 104100 1943 87900 65800 86800 105600 150600 116000 132400 202600 134300 147700 101300 88900 118300 1944 81300 77200 96800 99300 110600 78700 88200 88000 69100 81200 94600 84400 87400 1945 90100 90900 103600 88500 94000 86500 77800 112800 67800 88800 99300 87400 90600 1946 86200 85700 92500 95600 117700 90800 112200 178100 170900 134500 94400 91100 112500 1947 79600 81300 93100 116000 137800 135200 155900 184400 163400 136300 89900 85500 121500 1948 94700 96000 113900 113200 202800 166700 137700 193400 257600 194700 122900 101900 149600 1949 88000 83600 97700 126000 114000 80000 123000 166400 181600 82700 92200 87800 110200 1950 79000 69500 106800 123300 155200 145400 136400 197500 200200 211900 114800 96200 136400 1951 91800 87900 102600 115400 223400 186200 195600 188800 171300 174300 110300 91700 144900 1952 94200 98800 112200 126500 155200 113300 134600 172400 135800 145100 88700 85900 121900 1953 85500 83900 103900 95500 124800 87800 98700 174000 168300 141400 99000 89200 112700 1954 83600 89800 110300 122100 153600 135200 124200 191200 224900 228400 163600 114400 145100 1955 98700 103400 126600 132400 143900 102700 110500 104300 181800 193300 111900 91000 125000 1956 95700 94500 97000 108100 206500 200600 173500 245800 212600 200400 103600 90700 152400 1957 87400 82900 109400 132100 145100 101200 113600 182700 176500 120900 89000 86900 119000 1958 77500 75200 83300 120200 123700 107300 125000 172800 172900 Mean 87800 84700 101700 113200 132100 108600 119000 147900 147200 132800 102400 91800 114100 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-39 Table 2.4-5 Dependable Yield, Columbia River Below Priest Rapids Dam, Washington Consecutive Years of Lowest Mean Flow Inclusive Years Lowest Mean Flow (cfs) Percent of 1929-1958 Mean 1 1937 86,600 75.9 2 1930-31 89,900 78.8 3 1929-31 92,900 81.4 4 1929-32 95,800 84.0 5 1937-41 96,400 84.5 6 1937-42 97,300 85.3 7 1936-42 98,400 86.2 8 1937-44 99,000 86.8 9 1937-45 97,900 85.8 10 1936-45 98,600 86.4 11 1929-58 114,100 100.0 COLUMBIA GENERATING STATION Amendment 53 FINAL SAFETY ANALYSIS REPORT November 1998 2.4-40 Table 2.4-6 Major Geologic Units in the Hanford Region and Their Water-Bearing Properties System Series Geologic Unit Material Water-Bearing Properties Fluviatile and glaciofluviatile sediments and the Touchet formation

(0-200 ft thick) Sands and gravels occurring chiefly as glacial outwash. Unconsolidated, tending toward coarseness and angularity of grains, essentially free of fines. Where below the water table, such deposits have very high permeability and are capable of storing vast amounts of water.

Highest permeability value determined was 12,000 ft/day. Pleistocene Palouse soil Wind deposited silt. Occurs everywhere above the water table. Quaternary Ringold formation (200-1200 ft thick) Well-bedded lacustrine silts and sands and local beds of clay and gravel.

Poorly sorted, locally semi-consolidated or cemented. Generally divided into the lower "blue clay" portion which contains considerable sand and gravel, the middle conglomerate portion, and the upper silts and fine sand portion. Has relatively low permeability; values range from 1 to 200 ft/day. Storage capacity correspondingly low. In very minor part, a few beds of gravel and sand are sufficiently clean that permeability is moderately large; on the other hand, some beds of silty clay or clay are essentially impermeable. Miocene and Pliocene Columbia River basalt series (10,000 ft thick) Basaltic lavas with interbedded sedimentary rocks, considerably deformed. Underlie the unconsolidated sediments. Rocks are generally dense except for numerous shrink-age cracks, interflow scoria zones, and interbedded sediments. Permeability of rocks is small (e.g.,

0.002 to 9 ft/day) but transmissivity of a thick section may be considerable (70 to 700 ft2/day)

Amendment 55May 2001Hydrographic Map990306.302.4-1FigureForm No. 960690Draw. No.Rev.Yakima RiverRichlandPascoKennewickWalla Walla RiverSnake RiverN. Richland20 mi.15 mi.10 mi.5 mi.2 mi.PlantSiteColumbia RiverCoulee CreekRattlesnake CreekCrab CreekPowerColumbia RiverColumbia Generating StationFinal Safety Analysis Report

Discharge and Temperature of the Columbia Riverat Priest Rapids990306.062.4-4FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.Temperature (C)Q (kcfs)Record TMax19.9 (1963)1020Jan1020Feb1020Mar1020Apr1020May1020June1020July1020Aug1020Sept1020Oct1020Nov1020Dec0246810 1214160/181000/18200400 500 600700800(E)Estimated from high water marks at Wenatchee(I)Based on USGS-published weekly averages atPriest Rapids for the period 1953 - 67(2)USGS-Published daily averages atPriest Rapids.(3)Daily averages for the USGS Gaging Stationat Priest Rapids.(4)Based on 15-day moving averages for the1960- 68 period of record at Priest Rapids.1963(3)1969 and Record TMin 0.0Normal (I)1969 (2)1969 TMax19.71969 QMax320Normal (4)1956 QMax 5.541948 QMax 693Record QMax 740 9Discharge (Q) and temperature (T) of the Columbia River at Priest Rapids during 1969 with miscellaneous data for prior years (p)(p) Unless otherwise specified, pre-1960 data are for Trinidad. A gaging station about 23 miles downstream from WenatcheeColumbia Generating StationFinal Safety Analysis Report Columbia River Water Surface ProfilesRiver Miles 323 to 358990306.072.4-5FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.1,360,000 CFS725,000 CFS300,000 CFS36,000 CFS725,000 CFS300,000 CFS36,000 CFS1,360,000 CFS500480460440420400380360340358Elevation Above MSLRiver Miles355350345340330325335328Elevation Above MSL7,200,000 CFS5,969,000 CFS4,768,000 CFSGround El. at Plant SiteGround El. atMake-up Water Pumphouse6,800,000 CFS5,646,000 CFS4,512,000 CFS2,200,000 CFSMouth of Yakima RiverMouth of Snake RiverColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001PMF Hydrograph Due to Thunderstorm PMP990306.312.4-7FigureForm No. 960690Draw. No.Rev.Time (Hours)24681012141618246 8101214 16 182022Probable Maximum FloodHydrograph @ X-sec 1Peak Flow = 21,400 cfsColumbia Generating StationFinal Safety Analysis Report

Amendment 57December 2003Probable Maximum Precipitation ChannelCross Sections990306.082.4-9FigureForm No. 960690Draw. No.Rev.14364324284244364324284244204364324284244204164364324284244204164364324284244204164364324284244204164124084364324284244204164124084364324284244204164124084364324284244204164364324284244204163000250020001500 100050005001000 150035003000250020001500100050005001000436432428424420200015001000500050010001500243598761011Distance (feet)Overbank areasElevation (feet MSL)Columbia Generating StationFinal Safety Analysis ReportLDCN-02-000 Amendment 55May 2001Water Surface Profile990306.322.4-10FigureForm No. 960690Draw. No.Rev.1234576891011X-SecCross Section NumbersElevation (Feet MSL)Distance (1000 Feet)024681012141618202224262830404406408410412414416418420422424426428430Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Effective Fetch Diagram990306.332.4-11FigureForm No. 960690Draw. No.Rev.Scale - 1" = 2000'Outline of MaximumStillwater PondEast Spray PondCentral Radial6789101112131415R1R2R3R4R5Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Computed Long-Term Temperature Trends on theColumbia River at Rock Island Dam(1938 - 1962)990306.342.4-12FigureForm No. 960690Draw. No.Rev.706050 4032Upper ExtremeMeanLower ExtremeCalender YearsRiver Temperature, °F19401948195619641972Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001River Elevation at Low Flows - River Mile 352990306.352.4-13FigureForm No. 960690Draw. No.Rev.360350340330Flow KCFSElevation - ft above MSL020304050607010Columbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Duration Curves Columbia River, Priest RapidsDam990306.362.4-14FigureForm No. 960690Draw. No.Rev.3002001000Percent of Time Equaled or ExceededDischarge, Thousand Cubic Feet per Second0203040506070809010010Period: 1929 - 19581970 ConditionsAnnualMonthlyColumbia Generating StationFinal Safety Analysis Report Amendment 55May 2001Frequency Curves of High and Low Flows for theColumbia River Below Priest Rapids Dam990306.372.4-15FigureForm No. 960690Draw. No.Rev.Period1 Month3 Month6 Month12 Month6 Month3 Month 1 MonthPeriod of record 1929 - 19581970 ConditionsHigh Flows30020010050Low FlowsRecurrence Interval, YearsMean Discharge, 1000 cfs1.11.523510203050mean 115,000 cfs12 monthsColumbia Generating StationFinal Safety Analysis Report

Amendment 57December 2003Hanford Reservation Water Table Map (December1975)010126.532.4-18FigureForm No. 960690Draw. No.Rev.Yakima RiverColumbia RiverSource:Atlantic Richfield Hanford CompanyReport ARH -ST-137 Dated Nov. 1976Columbia RiverHanfordReservationGableMountainPond434(132)B Pond574(172)West Lake403(123)200 W200 EU Pond656(200)RichlandWater Table Contoursin Feet and (Meters) above Mean Sea LevelPonds with Water Surfacein Feet and (Meters) above Mean Sea LevelKilometers1005Miles1005LEGEND:470(143)350(107)360(110)370(113)380(116)390(119)400(122)410(125)420(128)430(131)440(114)490(149)510 (155)500 (152)0480 (146)460(140)450(137)LDCN-02-000Columbia Generating StationFinal Safety Analysis Report

Rev.FigureDraw. No.Form No. 960690LDCN-06-000Amendment 59December 2007020361.092.4-22Nitrate (NO3) Concentrations (December 1976)Columbia Generating StationFinal Safety Analysis Report

Well Hydrographs990306.092.4-27.1FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.506070370360380390Water Elevation (FT-MSL)506070506070Calender YearWell No. 699-23Casing Elev = 477.14Well No. 699-17-5 Casing Elev = 433.19Well No. 699-9-E2 Casing Elev = 418.48506070360350370Water Elevation (FT-MSL)506070506070506070Calender YearWell No. 699-20-ESTCasing Elev = 467.69Well No. 699-14E6T Casing Elev = 458.38Well No. 699-20-E12 Casing Elev = 437.25Well No. 699-10-E12 Casing Elev = 430.86Columbia Generating StationFinal Safety Analysis Report Well Hydrographs990306.392.4-27.2FigureAmendment 55May 2001Form No. 960690Draw. No.Rev.Water Elevation, Ft-MSL385384 383382381380Well Number 699-20-E12-P37962Calender YearCalender YearCalender Year657075Well Number699-10-E12-P391390389388387 386657075Well Number699-14-E6P6668707274389388387386Water Elevation, Ft-MSLCasing Elevation437.45 Ft-MSL646668707274Well Number699-20-E5-PCasing Elevation467.04 Ft-MSLCasing Elev.

458.44 Ft-MSLCasing Elev.

431.20 Ft-MSLColumbia Generating StationFinal Safety Analysis Report COLUMBIA GENERATING STATION Amendment 58 FINAL SAFETY ANALYSIS REPORT December 2005 LDCN-05-050 2.5-1 2.5 GEOLOGY, SEISMOLOGY, AND GEOTECHNICAL ENGINEERING The information discussing the geology, seismology, and geotechnical engineering is contained in a technical memorandum, TM-2143, "Geology, Seismology, and Geotechnical Engineering Report." This report is incorporated by reference into the FSAR and as such is subject to the same controls as the FSAR.