ML23006A139

0 to Updated Safety Analysis Report, Section 2, Site and Environs

ML23006A139
Person / Time
Site:	Monticello
Issue date:	12/19/2022
From:	Xcel Energy, Northern States Power Company, Minnesota
To:	Office of Nuclear Reactor Regulation
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ML23006A159	List: L-MT-22-021, 0 to Updated Safety Analysis Report, Appendix K, Revision 37, Renewed Operating License-USAR Supplement ML23006A127 ML23006A128 ML23006A129 ML23006A130 ML23006A132 ML23006A133 ML23006A134 ML23006A135 ML23006A136 ML23006A137 ML23006A138 ML23006A139 ML23006A140 ML23006A141 ML23006A142 ML23006A143 ML23006A144 ML23006A145 ML23006A146 ML23006A147 ML23006A148 ML23006A149 ML23006A150 ML23006A151 ML23006A152 ML23006A153 ML23006A155 ML23006A156
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MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 1 of 79 TABLE OF CONTENTS Section Page 2.1 Introduction .................................................................................................4 2.2 Site Description ..........................................................................................4 2.2.1 Location ......................................................................................................4 2.2.2 Topography ................................................................................................5 2.2.3 Access ........................................................................................................5 2.2.4 Land Use ....................................................................................................5 2.2.5 Population Distribution................................................................................5 2.2.6 Conclusions ................................................................................................6 Table 2.2-1 Estimated 2010 Resident Population Distribution Around the Monticello Nuclear Generating Plant ...........................................................................7 2.3 Meterology ..................................................................................................8 2.3.1 General.......................................................................................................8 2.3.2 Temperature ...............................................................................................8 2.3.3 Precipitation ................................................................................................8 2.3.4 Winds and Wind Loading............................................................................9 2.3.4.1 Tornadoes and Severe Thunderstorms .................................................... 10 2.3.4.2 Conclusions .............................................................................................. 10 2.3.5 Plant Design Based on Meterology .......................................................... 11 Table 2.3-1 Monthly Air Temperature .......................................................................... 12 Table 2.3-2 Summary of Precipitation Statistics .......................................................... 13 Table 2.3-3 Average Monthly Snowfall (inches) .......................................................... 14 Table 2.3-4 Snow Load Data ....................................................................................... 15 Table 2.3-5 Wind Frequency Distributions at 10 Meter Level, Stability Class A .......... 16 Table 2.3-6 Wind Frequency Distributions at 10 Meter Level, Stability Class B .......... 17 Table 2.3-7 Wind Frequency Distributions at 10 Meter Level, Stability Class C .......... 18 Table 2.3-8 Wind Frequency Distributions at 10 Meter Level, Stability Class D .......... 19 Table 2.3-9 Wind Frequency Distributions at 10 Meter Level, Stability Class E .......... 20 Table 2.3-10 Wind Frequency Distributions at 10 Meter Level, Stability Class F .......... 21 Table 2.3-11 Wind Frequency Distributions at 10 Meter Level, Stability Class G .......... 22 Table 2.3-12 Wind Frequency Distributions at 10 Meter Level, All Classes Combined . 23 Table 2.3-13 Wind Frequency Distributions at 100 Meter Level, Stability Class A ........ 25 Table 2.3-14 Wind Frequency Distributions at 100 Meter Level, Stability Class B ........ 26 Table 2.3-15 Wind Frequency Distributions at 100 Meter Level, Stability Class C ........ 27 Table 2.3-16 Wind Frequency Distributions at 100 Meter Level, Stability Class D ........ 28

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 2 of 79 Table 2.3-17 Wind Frequency Distributions at 100 Meter Level, Stability Class E ........ 29 Table 2.3-18 Wind Frequency Distributions at 100 Meter Level, Stability Class F......... 30 Table 2.3-19 Wind Frequency Distributions at 100 Meter Level, Stability Class G ........ 31 Table 2.3-20 Wind Frequency Distributions at 100 Meter Level, All Classes Combined ................................................................................................. 32 Table 2.3-21 Maximum Wind Velocity ........................................................................... 34 Table 2.3-22 Annual Average Dispersion Factor (X/Q) - Reactor Building Vent Releases .................................................................................................. 35 Table 2.3-23 Annual Average Dispersion Factor (X/Q) - Plant Stack Releases ........... 36 Table 2.3-24 Relative Deposition per Unit Area (D/Q) - Reactor Building Vent Releases .................................................................................................. 37 Table 2.3-25 Relative Deposition per Unit Area (D/Q) - Plant Stack Releases ............. 38 Table 2.3-26 Site Boundary X/Q and D/Q - Reactor Building Vent Releases ................ 39 Table 2.3-27 Site Boundary X/Q and D/Q - Plant Stack Releases................................ 40 2.4 Hydrology ................................................................................................. 41 2.4.1 Surface Water .......................................................................................... 41 2.4.2 Public Water Supplies .............................................................................. 42 2.4.2.1 Surface Water .......................................................................................... 42 2.4.2.2 Ground Water ........................................................................................... 43 2.4.3 Plant Design Bases Dependent on Hydrology .......................................... 43 2.4.4 Water Use Permits and Appropriations Relevant to Plant Operation ....... 44 2.4.4.1 Site Active Water Ground Supply Wells ................................................... 44 2.4.4.2 Impacts on Ground Water Around Power Block Structures ...................... 44 2.4.5 Surface Water Quality .............................................................................. 46 2.4.6 Environmental Assessment ...................................................................... 47 Table 2.4-1 Mississippi River Flows at Elk River and St. Cloud, Minnesota ................ 47 2.5 Geology and Soil Investigation ................................................................. 48 2.5.1 General..................................................................................................... 48 2.5.2 Regional Geology ..................................................................................... 48 2.5.3 Site Geology ............................................................................................. 49 2.5.4 Groundwater ............................................................................................. 50 2.5.5 Foundation Investigation .......................................................................... 50 2.5.6 Conclusions .............................................................................................. 50 Table 2.5-1 Geologic Formations in the General Area of the Site ............................... 51 2.6 Seismology ............................................................................................... 52 2.6.1 General..................................................................................................... 52 2.6.2 Seismic History ......................................................................................... 52

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 3 of 79 2.6.3 Faulting in Area ........................................................................................ 52 2.6.4 Design Criteria .......................................................................................... 53 2.6.5 Seismic Monitoring System ...................................................................... 53 Table 2.6-1 Seismic History of the Region .................................................................. 55 Table 2.6-2 Modified Mercalli Intensity Scale of 1931 (Abridged) ................................ 57 2.7 Radiation Environmental Monitoring Program (REMP) ............................ 58 2.7.1 Program Design and Data Interpretation .................................................. 58 2.7.2 Program Description ................................................................................. 58 2.7.3 Interlaboratory Comparison Program ....................................................... 59 2.8 Ecological and Biological Studies ............................................................. 59 2.9 Consequences of Hypothetical Local Catastrophes ................................. 59 2.9.1 Toxic Chemical Spills ............................................................................... 59 2.10 References ............................................................................................... 60 FIGURES ................................................................................................................. 63 Figure 2.2-1 Monticello Property Map ........................................................................... 64 Figure 2.3-1 Return Period of Extreme Short-Interval Rainfall, Minneapolis, MN ......... 65 Figure 2.4-1 Flow Duration Curve, Mississippi River at St. Cloud, MN ......................... 66 Figure 2.4-2 1965 Spring Flood at Monticello Site ........................................................ 67 Figure 2.4-3 Flood Frequency Study - Mississippi River at Monticello Site .................. 68 Figure 2.5-1a Flood Frequency Study - Mississippi River at Monticello Site .................. 69 Figure 2.5-1b Regional Geology Map ............................................................................. 70 Figure 2.5-2 Location of Original Borings ..................................................................... 71 Figure 2.5-3 Geologic Cross Section A-A ..................................................................... 72 Figure 2.5-4 Log of Borings Sheet 1 ............................................................................. 73 Figure 2.5-5 Log of Borings Sheet 2 ............................................................................. 74 Figure 2.6-1 Principal Earthquakes - Minnesota Region............................................... 75 Figure 2.6-2 Tectonic Map of Minnesota Region .......................................................... 76 Figure 2.6-3 Seismic Regionalization U.S.A. ................................................................ 77 Figure 2.6-4 Seismic Probability Map of U.S.A. ............................................................ 78 Figure 2.6-5 Seismic Response Spectra ...................................................................... 79

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 4 of 79 2.1 Introduction The Monticello site was thoroughly investigated as a site for a nuclear power plant and found to be suitable as evidenced by issuance of a construction permit (Docket No.

50-263) on June 19, 1967.

Section 2 contains information on the site and environs of the Monticello Nuclear Generating Station.

2.2 Site Description 2.2.1 Location The plant is located within the city limits of Monticello, Minnesota (1990 population 4,941), on the right bank of the Mississippi River in Section 33, T-122N, R-25W, in Wright County, Minnesota, at 45° 20 N latitude and 93° 50 W longitude. The reactor center line is located at approximately 850,810 feet North and 2,036,920 feet East as determined on the Minnesota State Grid, South Zone.

604000000820 The plant site consists of approximately 2000 acres of land owned in fee by Northern States Power Company, a wholly owned operating subsidiary of Xcel Energy Corporation (Xcel Energy). Part of this property is on the left bank of the river in Sherburne County and part is on the right bank in Wright County. Drawing ND-95208, Section 15, shows the plant site boundaries. This figure also shows an outline of the minimum fenced area which defines the restricted area boundary or site boundary for gaseous releases in accordance with10CFR20 and Appendix I to 10CFR50. Due to the prevailing wind pattern, the direction of maximum integrated dosage for normal effluent releases is SSE. The southern property line generally follows the northern boundary of the right-of-way for the Burlington Northern Railway. The exclusion zone has been arbitrarily selected to occupy the same fenced area. This more than satisfies the 10CFR100 (as augmented by 10CFR50.67) definition of an exclusion zone. Access to the exclusion zone is restricted by a perimeter fence with No Trespassing signs posted at intervals along the fence. Access to the exclusion zone by water is not restricted by a fence; however, No Trespassing signs are placed at intervals along the shoreline of the river.

The nearest site boundary is approximately 1630 feet S 30 degrees W of the reactor center line. The distance to the nearest residence is about 0.6 mile to the southwest, and the nearest large city, St. Cloud, is 22 miles upstream from the plant site. The northwestern suburbs of Minneapolis are about 30 miles southeast from the site.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 5 of 79 2.2.2 Topography The topography of the Monticello site is characterized by relatively level bluffs which rise sharply above the river. Three distinct bluffs exist at the plant site at elevations 920, 930, and 940 feet above mean sea level (ft msl). Normal river is 905 ft msl, and the maximum reported flood is at 916 ft msl.

Bluffs located about 1 mile north and south of the site rise to 950 ft msl. Beyond 1 mile north, the terrain is relatively level with numerous lakes and wooded areas. To the south, west, and east, the terrain is hilly and dotted with numerous small lakes.

2.2.3 Access 604000000832 Highway access is available to Wright County Road 75 which is about 4,500 feet southeast of the reactor building. Interstate 94 runs northwest from Minneapolis about 2,000 feet southwest of the site. Drawing ND-95208, Section 15, shows the location of these highways.

604000000832 Railroad access is available from the Burlington Northern track which is about 2,000 feet southwest. The site is served by a spur from this line.

The reach of the Mississippi River near the site is not suitable for navigation because its gradient is very steep and numerous shoals exist due to the current.

2.2.4 Land Use The land surrounding the site is predominantly rural. There are a few small villages and many lakes within a 15-mile radius of the site. The terrain is heavily wooded along the river, while the bluffs away from the river are cultivated and used for dairy farming.

Crops raised in the area include soybeans, corn, oats, hay, and potatoes.

2.2.5 Population Distribution The area in which the Monticello Plant is located is principally rural in character and the land is used primarily for farming. The main residential and business district of Monticello is about 3 miles southeast of the plant. Other nearby communities include:

Becker (2010 population of 4,538) about 4 miles northwest; Big Lake (2010 population of 10,060) about 5 miles east; Maple Lake (2010 population of 2,059) about 10 miles southwest; and Buffalo (2010 population of 15,453) about 10 miles south. The closest large cities are St. Cloud (2010 population of 65,842) about 20 miles northwest and Minneapolis (2010 population of 382,578) and St. Paul (2010 population of 285,068) about 30 miles southeast of the plant.

The resident population within the 10 mile Emergency Planning Zone (EPZ) (2010 estimate) is approximately 68,635. Similarly, within a 50-mile radius of the plant (approx. 7,850 square miles) the population in 1990 is estimated to be 2,273,213, of which about 90% reside in the Minneapolis-St. Paul metropolitan area. The projected population within the 50-mile radius in the year 2000 is approximately 2.25 million.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 6 of 79 In Wright County and in Sherburne County, immediately across the Mississippi River to the Northeast, about 80% of the land is used for farming. It is expected that these two counties will remain largely agricultural.

Table 2.2-1 shows the 2010 population.

The low population zone radius for the Monticello facility has arbitrarily been selected as one mile. Due to the sparse population of the area there will be no difficulty in taking appropriate protective action in the event of a serious accident. Based on the 10CFR100 (as augmented by 10CFR50.67) definition of a low population zone radius and the radiological effects presented in Section 14, the selection of a one-mile radius is more than adequate.

In November 2012 an updated Monticello Evacuation Time Estimate was completed.

This study was based on the most recent (2010) census estimates and considered factors such as transient and seasonal population changes, special facilities, and changes in the area transportation (roadway) network.

2.2.6 Conclusions The population distribution around the site is quite low. Good isolation from population centers is evident. Land use is devoted to agriculture. Therefore, from the population distribution and land usage viewpoint, the site is suitable for the facility as designed.

The analyses of design basis accidents in Section 14 verify that maximum expected doses at or beyond the exclusion area boundary are well below the reference doses given in 10CFR50.67

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 7 of 79 Table 2.2-1 Estimated 2010 Resident Population Distribution Around the Monticello Nuclear Generating Plant Radius (MILES) N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL 0-1 0 0 0 0 0 0 0 0 22 0 0 0 0 0 0 0 22 1-2 4 0 0 0 205 63 919 319 0 143 0 122 61 98 0 0 1,934 2-3 0 2 11 135 110 455 1,417 89 0 220 0 94 22 1 0 0 2,556 3-4 533 4 313 1,356 272 358 2,189 1,174 130 0 322 84 164 32 29 44 7,004 4-5 568 244 304 2,970 1,718 827 2,328 687 263 124 115 29 11 232 39 1,044 11,503 5-6 476 78 256 1,112 3,088 1,341 2,571 81 46 73 161 57 59 175 32 1,847 11,453 6-7 144 319 419 527 179 407 349 112 139 101 123 40 299 104 4 464 3,730 7-8 125 546 603 683 640 492 103 46 327 141 100 176 167 203 275 719 5,346 8-9 141 304 276 932 292 869 103 70 1,361 237 365 147 273 135 65 171 5,741 9-10 179 391 350 537 1,014 526 164 64 2,701 248 178 94 184 181 130 71 7,012 10-11* 404 138 519 208 652 325 1,260 150 3,281 104 2,238 345 154 1,993 196 367 12,334 TOTAL 2,574 2,026 3,051 8,460 8,170 5,663 11,403 2,792 8,270 1,391 3,602 1,188 1,394 3,154 770 4,727 68,635

• Note this population is the remainder of the 10-Mile EPZ due to geopolitical boundaries which extend into the 10-11 mile range.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 8 of 79 2.3 Meterology 2.3.1 General Travelers Research Corporation analyzed the meteorology of the plant site. Initial design criteria related to meteorology were based on data taken at St. Cloud and Minneapolis. Since the original Facility Description and Safety Analysis Report was written, a meteorological program was established to provide actual on-site meteorological data. The data obtained from this program are summarized in USAR Tables 2.3-5 through 2.3-20. These data confirm the adequacy of the initial design criteria used in the plant design.

The general climatic regime of the site is that of a marked continental type characterized by wide variations in temperature, scanty winter precipitation, normally ample summer rainfall, and a general tendency to extremes in all climatic features. Of special interest are the extremes in annual snowfall, which may be as little as six inches or as much as 88 inches; a temperature range of 145°F for the period of record; occasional severe thunderstorms with heavy rainfall and high winds; and the possibility of an occasional tornado or ice storm. These and other pertinent meteorological data are presented in the following sections.

2.3.2 Temperature Average and extreme monthly air temperatures for the Monticello site are not available, but 54 years of data for St. Cloud and Minneapolis - St. Paul have been adjusted to give representative average values for the site area. The site is approximately 13 miles closer to St. Cloud than to Minneapolis. A summary of monthly air temperatures from January to December is given in Table 2.3-1.

2.3.3 Precipitation Precipitation in the Monticello area is typical for the marked continental climate, with scanty winter precipitation and normally ample summer rainfall. The months of May through September have the greatest amounts of precipitation; average fall of rain during this period is 17-18 inches, or more than 70% of the annual rainfall.

Thunderstorms are the principal source of rain during May through September and the Monticello area normally experiences 36 of these annually. The heaviest rainfall also occurs during a particularly severe thunderstorm. A summary of precipitation statistics is shown in Table 2.3-2 (based on St. Cloud and Minneapolis - St. Paul averages).

Average monthly snowfall statistics are given in Table 2.3-3.

Intense rainfall is produced by an occasional severe thunderstorm. The return period of extreme short interval rainfall is a useful guide. The nearest location for which return period data are available and which should be reasonably representative for the Monticello area is Minneapolis. This data is shown in Figure 2.3-1.

Snow load data available from a Housing and Home Finance Agency (HHFA) study conducted in 1952 (Reference 18) are given in Table 2.3-4.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 9 of 79 Data relating to freezing rain and resultant formation of glaze ice on highways and utility lines are available from the following studies:

American Telephone and Telegraph Company, 1917-18 to 1924-25 (Reference 19)

Edison Electric Institute, 1926-27 to 1937-38 (Reference 20)

Association of American Railroads, 1928-29 to 1936-37 (Reference 21)

Quartermaster Research and Engineering Command, U.S. Army, 1959 (Reference 22)

The U.S. Weather Bureau also maintains annual summaries. The following is a fairly accurate description of the glaze-ice climatology of middle Minnesota.

Time of occurrence - October through April Average frequency without regard to ice thickness, 1-2 storms per year Duration of ice on utility lines - 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (mean) to 83 hours9.606481e-4 days <br />0.0231 hours <br />1.372354e-4 weeks <br />3.15815e-5 months <br /> (maximum of record)

Return periods for freezing rain storms producing ice of various thickness are:

0.25 inch - Once every 2 years 0.50 inch - Once every 2 years 0.75 inch - Once every 3 years 2.3.4 Winds and Wind Loading The preoperational meteorological data program is described in Sections 2.3.4 and 2.3.5 of the FSAR. The Monticello plant is currently provided with a 100-meter meteorological tower. Wind speed, direction, and temperature difference instrumentation is located at approximately ten meters and at the elevation of the plant effluent point (43 meters and 100 meters). In addition, temperature and rainfall instruments are provided. Meteorological data is used to compute dispersion (X/Q) and deposition (D/Q) factors for use in the dose assessment of airborne releases. Wind speed, direction, and atmosphere stability class are averaged over the release period and serve as inputs to a dispersion model. Stability class is determined using temperature difference measurements between the ten meter elevation and the elevation of the release.

Wind frequency distributions for the 10 and 100 meter tower elevations for the period January 1, 1980 through December 31, 1980 are presented in Tables 2.3-5 through 2.3-20. The distributions are for Stability A through G, as defined in Table 1 of the proposed revision 1 to Regulatory Guide 1.23 issued September 1980 (Reference 39).

Annual average dispersion factor (X/Q) and deposition per unit area (D/Q) were computed for this period and are presented in Tables 2.3-22 through 2.3-27. NRC computer code XOQDOQ was used for these calculations (Reference 14). This historical data may be useful in estimating off-site doses due to routine releases of airborne radioactive effluents from the reactor building vent and plant stack.

Wind frequency distributions for the 10, 43 and 100 meter tower elevations for the period of January 1, 1998 through December 31, 2002 were prepared for use in calculating atmospheric dispersion coefficients for design basis radiological consequences analysis using Alternative Source Term Methodology (reference USAR Section 14.7). These distributions apply only to the accident analyses.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 10 of 79 2.3.4.1 Tornadoes and Severe Thunderstorms Severe storms such as tornadoes are not numerous, but they do occur occasionally.

The latitude of the Monticello site places it at the northern edge of the region of maximum tornado frequency in the United States, but only a few tornadoes have occurred in this vicinity. Eight tornadoes have been reported in Wright County during the period 1916-1967, two of which subsequently moved across the Mississippi River into Sherburne County.

A 1-degree square1, lying between 45 and 46 degrees north, and between 93 and 94 degrees west, encompasses the Monticello site. There have been approximately eight tornado occurrences reported in this 1-degree square in the 14-year test period, 1953-1966. The ratio of eight tornadoes in 14 years gives a mean annual tornado frequency of 0.6. This frequency is confirmed by the Mean Annual Tornado Frequency figures published by the U.S. Department of Commerce, Weather Bureau (Reference 31).

Using the methods described by H. C. S. Thom (Reference 2), with a mean annual tornado frequency of 0.6, the probability of a tornado striking a given point in the outlined 1-degree square, which encompasses the Monticello site, can be calculated to be 5x10-4 per year, or one tornado every 2000 years. The effects of the tornado phenomenon including possible effects of missiles and water loss effects in the fuel pool are discussed in Reference 3 of this section.

Subsequently, it was determined the drywell head could become a missile hazard for the spent fuel pool, however, since the probability is less than 10-7, it is not a credible missile.

The average number of thunderstorms for Minneapolis and St. Cloud is 36 with more than half of these occurring in June, July, and August. Therefore, it is expected that the Monticello site may experience an average of 36 thunder- storms annually. The fastest wind recorded for 54 years of record for each month at Minneapolis is given in Table 2.3-21.

2.3.4.2 Conclusions The meteorology of the site area is basically that of a marked continental area with relatively favorable atmospheric dilution conditions prevailing. Diffusion climatology comparisons with other locations indicate that the site is typical of the North Central United States. Frequency of inversion is expected to be 30-40% of the year.

The site is located in an area occasionally traversed by storms and tornadoes.

Maximum reported wind speed associated with passage of storm is 92 mph.

1. In this area, a 1-degree square is approximately 3,354 square miles.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 11 of 79 2.3.5 Plant Design Based on Meterology The station is designed with an off-gas stack to be used for continuous dispersal of gases to the atmosphere. Based on meteorological data at the site, plant operational characteristics, and stack design, the off-site doses arising from routine plant operation will satisfy the guidelines of Appendix I to 10CFR50.

A listing of other relevant reference material is given in References 4 through 9.

Class I and Class II Station structures are designed to withstand the effects of 100 mph winds at 30-feet above ground with a gust factor of 1.1. Structures and systems which are necessary for a safe shutdown of the reactor and maintaining a shutdown condition are designed to withstand tornado wind loadings of 300 mph.

Bibliography: Rainfall Intensity - Duration - Frequency Curves, Tech. Paper No. 25, U.S. Weather Bureau (1955) (Reference 23).

Climatological Data with Comparative Data, Minneapolis - St. Paul, Minnesota, 1953-1956 - U.S. Weather Bureau (2 publications)

(Reference 24).

Climatological Data with Comparative Data, St. Cloud, Minnesota 1953-1965 - U.S. Weather Bureau (2 publications) (Reference 25).

Climatography of the United States, No. 86-17, Minnesota, U.S.

Weather Bureau (Reference 26).

Local Climatological Data with Comparative Data, 1965 - U.S.

Weather Bureau (Reference 27).

Snow Load Studies, Housing Research Paper 19, Housing and Home Finance Agency, 1952 (Reference 28).

Glaze, Its Meteorology and Climatology, Geographical Distribution and Economic Effects, Quartermaster Research and Engineering Center, 1959 (Reference 29).

Climatography of the United States No. 60-21, Minnesota - U.S.

Weather Bureau (Reference 30).

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 12 of 79 Table 2.3-1 Monthly Air Temperature Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Maximum 21 24 38 55 68 77 83 80 72 59 40 26 Minimum 3 6 20 35 46 56 61 59 50 39 24 10 Mean 12 15 29 45 57 66 72 70 61 49 32 18 Extreme Maximum 59 61 82 91 105 103 107 104 105 90 75 63 Extreme Minimum -38 -34 -30 4 20 33 42 38 22 8 29

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 13 of 79 Table 2.3-2 Summary of Precipitation Statistics Extreme Extreme Days with Monthly Monthly *Max. in Days with 0.01 inch Mean Min. Max. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Thunder Month or more (inches) (inches) (inches) (inches) storms Dec 9 0.77 T 2.48 1.05 0 Jan 8 0.78 0.02 2.82 1.90 0 Feb 7 0.80 0.01 3.10 1.83 0 Winter 24 2.35 - - - 0 March 10 1.32 0.11 3.95 2.00 1 April 9 1.94 0.32 5.72 3.15 2 May 12 3.11 0.20 10.00 5.00 5 Spring 31 6.37 - - - 8 June 13 4.06 0.87 9.78 3.35 8 July 10 2.86 0.31 12.34 4.80 7 Aug 10 2.83 0.31 8.99 4.62 6 Summer 33 9.75 - - - 21 Sept 9 2.92 0.24 9.24 3.65 4 Oct 8 1.65 .01 7.18 3.24 2 Nov 8 1.40 .01 4.66 1.44 1 Fall 25 5.97 T - - 7 Annual 113 24.44

• St. Cloud 1894-1965 T = TRACE

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 14 of 79 Table 2.3-3 Average Monthly Snowfall (inches)

Location Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann Minneapolis 6.3 8.0 11.5 2.7 0.2 0.0 0.0 0.0 0.1 0.3 6.1 7.0 42.2 St. Paul St. Cloud 6.5 7.7 11.5 2.8 0.1 0.0 0.0 0.0 0.1 0.4 6.3 7.0 42.4 Maximum in 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s: Minneapolis 16.2 inches St. Cloud 12.2 inches

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 15 of 79 Table 2.3-4 Snow Load Data Wt. of Estimated Wt. of Seasonal Max. Accumulation Snowpack Equalled Wt. of Max on Grd plus Wt.

or Exceeded 1 Yr Snowpack of Max. Possible Location in 10__________ of Record_ Storm Minneapolis 30 lb/ft2 40 lb/ft2 50 lb/ft2 St. Cloud 30 lb/ft2 40 lb/ft2 50 lb/ft2

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 16 of 79 Table 2.3-5 Wind Frequency Distributions at 10 Meter Level, Stability Class A (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 3 20 34 15 4 0 76 NNE 4 11 11 2 0 0 28 NE 5 17 23 1 0 0 46 ENE 9 25 13 0 0 0 47 E 4 18 12 3 1 0 38 ESE 4 24 32 7 1 0 68 SE 4 22 43 24 0 0 93 SSE 3 13 47 32 7 0 102 S 2 18 39 36 26 0 121 SSW 3 25 60 26 3 0 117 SW 2 21 43 10 0 0 76 WSW 5 27 34 18 1 0 85 W 3 25 12 15 4 0 59 WNW 5 21 34 22 5 0 87 NW 4 20 51 27 7 0 109 NNW 2 10 37 30 5 0 84 VAR 0 0 0 0 0 0 0 Total Hours this Class 1242 Hours of Calm this Class 6 Percent of all Data this Class 15.14

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 17 of 79 Table 2.3-6 Wind Frequency Distributions at 10 Meter Level, Stability Class B (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 1 7 11 3 0 0 22 NNE 0 6 4 0 1 0 11 NE 1 4 5 1 0 0 11 ENE 0 5 0 0 0 0 5 E 0 4 0 0 0 0 4 ESE 0 4 4 1 1 0 10 SE 0 4 2 1 1 0 8 SSE 1 5 3 3 2 0 14 S 3 5 3 3 0 0 14 SSW 2 2 7 2 0 0 13 SW 4 2 4 0 0 0 10 WSW 1 5 5 1 0 0 12 W 0 1 4 2 0 0 7 WNW 1 7 8 2 1 0 19 NW 1 7 9 6 3 0 26 NNW 1 8 8 4 1 0 22 VAR 0 0 0 0 0 0 0 Total Hours this Class 208 Hours of Calm this Class 0 Percent of all Data this Class 2.54

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 18 of 79 Table 2.3-7 Wind Frequency Distributions at 10 Meter Level, Stability Class C (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 4 14 15 5 2 0 40 NNE 1 7 11 1 0 0 20 NE 2 7 5 1 0 0 15 ENE 0 11 0 0 0 0 11 E 1 5 1 0 0 0 7 ESE 2 6 6 1 1 0 16 SE 0 5 8 2 2 0 17 SSE 0 7 6 7 0 0 20 S 1 5 9 4 1 1 21 SSW 0 6 4 1 0 1 12 SW 2 8 11 4 0 0 25 WSW 0 8 6 0 1 0 15 W 0 7 3 3 2 0 15 WNW 2 4 14 7 1 0 28 NW 2 1 12 2 1 0 18 NNW 0 8 16 8 0 0 32 VAR 0 0 0 0 0 0 0 Total Hours this Class 313 Hours of Calm this Class 1 Percent of all Data this Class 3.82

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 19 of 79 Table 2.3-8 Wind Frequency Distributions at 10 Meter Level, Stability Class D (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 37 83 118 62 10 0 310 NNE 19 56 55 18 3 0 151 NE 26 56 61 12 0 0 155 ENE 24 71 28 1 0 0 124 E 12 58 47 9 0 0 126 ESE 13 75 79 34 0 0 201 SE 11 63 123 40 6 0 243 SSE 13 35 80 14 1 0 143 S 11 34 53 26 6 0 130 SSW 8 31 36 8 4 1 88 SW 5 23 27 3 2 0 60 WSW 9 18 24 4 3 0 58 W 7 28 20 15 3 0 78 WNW 5 40 72 29 20 3 169 NW 17 37 95 55 25 1 230 NNW 26 69 170 108 14 0 387 VAR 0 0 0 0 0 0 0 Total Hours this Class 2753 Hours of Calm this Class 100 Percent of all Data this Class 33.56

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 20 of 79 Table 2.3-9 Wind Frequency Distributions at 10 Meter Level, Stability Class E (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 28 96 48 7 0 0 179 NNE 15 39 17 2 0 0 73 NE 19 50 21 3 0 0 93 ENE 17 30 13 1 0 0 61 E 14 35 19 1 0 0 69 ESE 13 61 45 2 0 0 121 SE 12 70 49 3 0 0 134 SSE 9 50 38 15 1 0 113 S 10 32 33 28 2 0 105 SSW 13 35 41 22 1 0 112 SW 15 21 18 5 0 0 59 WSW 15 28 14 11 0 0 68 W 18 43 30 2 0 0 93 WNW 9 101 98 22 0 0 230 NW 11 54 87 36 2 0 190 NNW 20 87 113 33 4 0 257 VAR 0 0 0 0 0 0 0 Total Hours this Class 2008 Hours of Calm this Class 51 Percent of all Data this Class 24.48

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 21 of 79 Table 2.3-10 Wind Frequency Distributions at 10 Meter Level, Stability Class F (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 29 35 2 0 0 0 66 NNE 8 14 2 0 0 0 24 NE 18 14 2 0 0 0 34 ENE 14 9 0 0 0 0 23 E 12 26 0 0 0 0 38 ESE 14 46 6 0 0 0 66 SE 9 40 6 5 0 0 60 SSE 15 36 9 2 2 1 65 S 9 29 19 0 0 0 57 SSW 14 33 8 2 0 0 57 SW 20 25 6 0 0 0 51 WSW 18 39 3 1 0 0 61 W 18 37 7 0 0 0 62 WNW 15 31 0 0 0 0 46 NW 17 29 10 0 0 0 56 NNW 14 69 11 0 0 0 94 VAR 0 0 0 0 0 0 0 Total Hours this Class 871 Hours of Calm this Class 11 Percent of all Data this Class 10.62

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 22 of 79 Table 2.3-11 Wind Frequency Distributions at 10 Meter Level, Stability Class G (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 43 23 1 0 0 0 67 NNE 16 7 1 0 0 0 24 NE 17 12 0 0 0 0 29 ENE 15 1 0 0 0 0 16 E 15 5 0 0 0 0 20 ESE 17 10 0 0 0 0 27 SE 18 14 0 0 0 0 32 SSE 35 30 0 0 0 0 65 S 33 44 6 0 0 0 83 SSW 49 35 3 0 0 0 87 SW 35 14 0 0 0 0 49 WSW 38 28 0 0 0 0 66 W 33 22 0 0 0 0 55 WNW 32 11 0 0 0 0 43 NW 26 19 0 0 0 0 45 NNW 41 30 0 0 0 0 71 VAR 0 0 0 0 0 0 0 Total Hours this Class 808 Hours of Calm this Class 29 Percent of all Data this Class 9.85

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 23 of 79 Table 2.3-12 Wind Frequency Distributions at 10 Meter Level, All Classes Combined (Hours at Each Wind Speed and Direction)

(Page 1 of 2)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 145 278 229 92 16 0 760 NNE 63 140 101 23 4 0 331 NE 88 160 117 18 0 0 383 ENE 79 152 54 2 0 0 287 E 58 151 79 13 1 0 302 ESE 63 226 172 45 3 0 509 SE 54 218 231 75 9 0 587 SSE 76 176 183 73 13 1 522 S 69 167 162 97 35 1 531 SSW 89 167 159 61 8 2 486 SW 83 114 109 22 2 0 330 WSW 86 153 86 35 5 0 365 W 79 163 76 37 14 0 369 WNW 69 215 226 82 27 3 622 NW 78 167 264 126 38 1 674 NNW 104 281 355 183 24 0 947 VAR 0 0 0 0 0 0 0 Data Recovery Summary for Period Total Hours 8784 Hours of Calm 198 Hours of Bad Data 581 Percent Data Recovery 93.39

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 24 of 79 Table 2.3-12 Wind Frequency Distributions at 10 Meter Level, All Classes Combined (Hours at Each Wind Speed and Direction)

(Page 2 of 2)

Percent Acceptable Observations in Each Stability Class Class A 15.14 Class B 2.54 Class C 3.82 Class D 33.56 Class E 24.48 Class F 10.62 Class G 9.85 Average Wind Speed for Each Wind Category 1 to 3 MPH 2.4 4 to 7 MPH 5.5 8 to 12 MPH 9.7 13 to 18 MPH 14.7 19 to 24 MPH 20.5 Above 24 MPH 25.8

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 25 of 79 Table 2.3-13 Wind Frequency Distributions at 100 Meter Level, Stability Class A (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 1 3 9 7 6 7 33 NNE 2 3 0 0 0 0 5 NE 0 1 0 1 0 0 2 ENE 0 2 2 0 0 0 4 E 0 0 0 1 0 0 1 ESE 0 6 7 16 3 2 34 SE 0 7 8 24 13 4 56 SSE 0 1 10 32 21 1 65 S 0 3 10 28 18 7 66 SSW 0 3 16 23 16 8 66 SW 1 6 9 16 6 2 40 WSW 0 1 9 24 18 0 52 W 0 3 8 8 17 3 39 WNW 1 1 4 2 7 4 19 NW 1 2 4 11 7 1 26 NNW 0 1 5 17 9 1 33 VAR 0 0 0 0 0 0 0 Total Hours this Class 656 Hours of Calm this Class 115 Percent of all Data this Class 7.98

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 26 of 79 Table 2.3-14 Wind Frequency Distributions at 100 Meter Level, Stability Class B (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 0 4 15 16 4 0 39 NNE 0 4 5 10 0 0 19 NE 0 3 10 3 0 0 16 ENE 1 3 6 1 0 0 11 E 0 2 3 0 0 0 5 ESE 0 3 7 2 2 1 15 SE 0 2 8 3 3 0 16 SSE 0 1 14 9 2 1 27 S 0 5 8 5 4 1 23 SSW 1 2 14 9 7 1 34 SW 1 4 14 5 2 0 26 WSW 0 4 6 5 5 0 20 W 0 5 6 4 4 3 22 WNW 0 2 4 2 1 5 14 NW 0 3 7 8 11 1 30 NNW 0 4 11 8 9 0 32 VAR 0 0 0 0 0 0 0 Total Hours this Class 349 Hours of Calm this Class 0 Percent of all Data this Class 4.25

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 27 of 79 Table 2.3-15 Wind Frequency Distributions at 100 Meter Level, Stability Class C (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 0 3 16 15 2 1 37 NNE 0 5 13 2 0 0 20 NE 0 2 2 4 0 0 8 ENE 0 4 11 0 0 0 15 E 0 3 9 2 1 0 15 ESE 0 8 6 5 0 0 19 SE 0 4 1 3 2 0 10 SSE 1 1 9 5 3 0 19 S 0 3 7 1 2 2 15 SSW 0 6 13 7 4 1 31 SW 0 4 4 6 1 1 16 WSW 0 4 7 7 0 0 18 W 0 4 4 5 3 1 17 WNW 2 3 11 7 5 7 35 NW 1 3 12 21 4 4 45 NNW 3 11 10 10 4 3 41 VAR 0 0 0 0 0 0 0 Total Hours this Class 361 Hours of Calm this Class 0 Percent of all Data this Class 4.39

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 28 of 79 Table 2.3-16 Wind Frequency Distributions at 100 Meter Level, Stability Class D (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 17 46 84 120 101 49 417 NNE 15 38 45 67 19 3 187 NE 10 21 36 37 18 6 128 ENE 6 36 60 34 4 1 141 E 10 45 51 25 12 5 148 ESE 12 39 59 56 44 15 225 SE 9 27 51 130 69 20 306 SSE 4 30 51 76 26 14 201 S 7 15 50 60 18 11 161 SSW 11 25 40 39 32 7 154 SW 6 22 25 28 16 8 105 WSW 6 17 17 33 9 7 89 W 5 27 15 22 18 15 102 WNW 13 26 47 61 48 41 236 NW 8 23 52 100 95 63 341 NNW 10 45 90 151 120 82 498 VAR 0 0 0 0 0 0 0 Total Hours this Class 3504 Hours of Calm this Class 65 Percent of all Data this Class 42.64

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 29 of 79 Table 2.3-17 Wind Frequency Distributions at 100 Meter Level, Stability Class E (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 2 16 36 80 54 12 200 NNE 1 12 20 51 17 1 102 NE 2 12 20 29 12 3 78 ENE 0 12 42 19 7 1 81 E 5 7 35 30 7 0 84 ESE 4 10 21 39 20 3 97 SE 0 8 25 61 32 4 130 SSE 2 9 27 76 40 5 159 S 2 14 30 36 36 18 136 SSW 1 4 23 43 52 20 143 SW 2 8 10 20 53 7 100 WSW 3 18 17 20 22 2 82 W 2 13 21 29 18 3 86 WNW 2 6 31 66 55 4 164 NW 2 14 29 75 50 2 172 NNW 3 15 31 68 67 11 195 VAR 0 0 0 0 0 0 0 Total Hours this Class 2032 Hours of Calm this Class 23 Percent of all Data this Class 24.73

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 30 of 79 Table 2.3-18 Wind Frequency Distributions at 100 Meter Level, Stability Class F (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 3 9 14 27 18 2 73 NNE 0 5 17 16 13 0 51 NE 1 6 22 13 7 1 50 ENE 0 6 21 14 0 0 41 E 2 6 13 18 3 0 42 ESE 0 6 9 18 7 1 41 SE 2 8 12 22 18 0 62 SSE 2 5 13 30 21 3 74 S 2 8 8 30 12 7 67 SSW 0 2 9 21 33 2 67 SW 1 2 8 42 30 0 83 WSW 2 8 10 19 23 5 67 W 1 6 17 14 10 1 49 WNW 3 8 17 37 11 1 77 NW 4 10 22 33 5 0 74 NNW 5 14 22 37 4 0 82 VAR 0 0 0 0 0 0 0 Total Hours this Class 1000 Hours of Calm this Class 0 Percent of all Data this Class 12.17

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 31 of 79 Table 2.3-19 Wind Frequency Distributions at 100 Meter Level, Stability Class G (Hours at Each Wind Speed and Direction)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 0 7 8 5 2 0 22 NNE 0 2 14 7 2 0 25 NE 1 3 7 6 2 0 19 ENE 1 3 9 1 0 0 14 E 0 2 5 6 0 0 13 ESE 0 3 3 5 0 0 11 SE 0 0 8 8 3 0 19 SSE 3 5 2 5 2 0 17 S 0 2 3 2 0 0 7 SSW 0 2 5 11 1 0 19 SW 0 8 13 7 7 0 35 WSW 3 4 11 3 4 1 26 W 0 3 13 6 2 0 24 WNW 0 3 11 5 4 0 23 NW 2 6 8 9 0 0 25 NNW 1 5 5 2 2 2 17 VAR 0 0 0 0 0 0 0 Total Hours this Class 316 Hours of Calm this Class 0 Percent of all Data this Class 3.85

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 32 of 79 Table 2.3-20 Wind Frequency Distributions at 100 Meter Level, All Classes Combined (Hours at Each Wind Speed and Direction)

(Page 1 of 2)

Wind Speed (MPH)

WIND DIRECTION 1-3 4-7 8-12 13-18 19-24 >24 TOTAL N 23 88 182 270 187 71 821 NNE 18 69 114 153 51 4 409 NE 14 48 97 93 39 10 301 ENE 8 66 151 69 11 2 307 E 17 65 116 82 23 5 308 ESE 16 75 112 141 76 22 442 SE 11 56 113 251 140 28 599 SSE 12 52 126 233 115 24 562 S 11 50 116 162 90 46 475 SSW 13 44 120 153 145 39 514 SW 11 54 83 124 115 18 405 WSW 14 56 77 111 81 15 354 W 8 61 84 88 72 26 339 WNW 21 49 125 180 131 62 568 NW 18 61 134 257 172 71 713 NNW 22 95 174 293 215 99 898 VAR 0 0 0 0 0 0 0 Data Recovery Summary for Period Total Hours 8784 Hours of Calm 203 Hours of Bad Data 566 Percent Data Recovery 93.56

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 33 of 79 Table 2.3-20 Wind Frequency Distributions at 100 Meter Level, All Classes Combined (Hours at Each Wind Speed and Direction)

(Page 2 of 2)

Percent Acceptable Observations in Each Stability Class Class A 7.98 Class B 4.25 Class C 4.39 Class D 42.64 Class E 24.73 Class F 12.17 Class G 3.85 Average Wind Speed for Each Wind Category 1 to 3 MPH 2.6 4 to 7 MPH 5.7 8 to 12 MPH 10.2 13 to 18 MPH 15.5 19 to 24 MPH 21.1 Above 24 MPH 28.2

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 34 of 79 Table 2.3-21 Maximum Wind Velocity Month Speed, MPH Direction Year Jan 47 NW 1928 Feb 52 NW 1952 March 56 SW 1920 April 58 N 1912 May 61 NW 1964 June 63 NW 1939 July 92* W 1951 August 57 NW 1922 September 50 NW 1921 October 73 S 1949 November 60 SW 1959 December 52 W 1946

• Associated with the July 20, 1951 tornado

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 35 of 79 Table 2.3-22 Annual Average Dispersion Factor (X/Q) - Reactor Building Vent Releases Reactor Building Vent No Decay, Undepleted Corrected for Open Terrain Recirculation Annual Average CHI/Q (Sec/Meter Cubed) Distance in Miles Sector 0.250 0.500 0.750 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 S 6.345E-06 2.532E-06 1.812E-06 1.206E-06 7.098E-07 4.539E-07 3.211E-07 2.736E-07 2.433E-07 2.106E-07 1.864E-07 SSW 2.742E-06 1.163E-06 8.628E-07 5.724E-07 3.233E-07 2.500E-07 2.108E-07 1.543E-07 1.192E-07 1.011E-07 8.773E-08 SW 2.985E-06 1.246E-06 9.472E-07 6.498E-07 3.851E-07 3.108E-07 2.672E-07 2.090E-07 1.704E-07 1.497E-07 1.320E-07 WSW 1.949E-06 8.250E-07 6.662E-07 4.821E-07 3.037E-07 2.462E-07 2.106E-07 1.548E-07 1.198E-07 1.071E-07 9.643E-08 W 2.393E-06 9.695E-07 7.325E-07 5.018E-07 3.014E-07 2.422E-07 2.084E-07 1.631E-07 1.329E-07 1.061E-07 8.733E-08 WNW 4.552E-06 1.768E-06 1.247E-06 8.060E-07 4.532E-07 3.477E-07 2.900E-07 2.393E-07 2.020E-07 1.594E-07 1.300E-07 NW 5.502E-06 2.094E-06 1.399E-06 8.565E-07 4.435E-07 2.855E-07 2.046E-07 1.688E-07 1.459E-07 1.235E-07 1.071E-07 NNW 4.704E-06 1.698E-06 1.112E-06 6.930E-07 3.859E-07 2.493E-07 1.796E-07 1.386E-07 1.121E-07 9.375E-08 8.041E-08 N 5.225E-06 1.822E-06 1.133E-06 6.806E-07 3.661E-07 2.315E-07 1.643E-07 1.347E-07 1.163E-07 9.604E-08 8.136E-08 NNE 4.357E-06 1.489E-06 9.479E-07 5.946E-07 3.437E-07 2.255E-07 1.642E-07 1.275E-07 1.035E-07 8.665E-07 7.431E-08 NE 2.523E-06 9.147E-07 5.967E-07 3.771E-07 2.148E-07 1.592E-07 1.290E-07 1.011E-07 8.234E-08 6.909E-08 5.929E-08 ENE 3.074E-06 1.035E-06 6.587E-07 4.245E-07 2.560E-07 1.829E-07 1.424E-07 1.119E-07 9.141E-08 7.688E-08 6.611E-08 E 3.142E-06 1.104E-06 7.441E-07 4.922E-07 2.963E-07 1.999E-07 1.471E-07 1.146E-07 9.290E-08 7.763E-08 6.638E-08 ESE 5.744E-06 2.195E-06 1.425E-06 8.550E-07 4.320E-07 2.693E-07 1.880E-07 1.411E-07 1.112E-07 9.091E-08 7.636E-08 SE 6.575E-06 2.438E-06 1.529E-06 8.966E-07 4.458E-07 2.949E-07 2.192E-07 1.638E-07 1.287E-07 1.049E-07 8.790E-08 SSE 9.467E-06 3.635E-06 2.343E-06 1.395E-06 7.007E-07 4.363E-07 3.045E-07 2.284E-07 1.801E-07 1.473E-07 1.239E-07 Annual Average CHI/Q (Sec/Meter Cubed) Distance in Miles Sector 5.000 7.500 10.000 15.000 20.000 25.000 30.000 35.000 40.000 45.000 50.000 S 1.584E-07 8.944E-08 6.152E-08 3.795E-08 2.685E-08 2.049E-08 1.641E-08 1.359E-08 1.155E-08 9.997E-09 8.787E-09 SSW 7.398E-08 4.073E-08 2.760E-08 1.673E-08 1.170E-08 8.858E-09 7.051E-09 5.812E-09 4.916E-09 4.241E-09 3.715E-09 SW 1.104E-07 5.913E-08 3.946E-08 2.349E-08 1.626E-08 1.223E-08 9.682E-09 7.949E-09 6.701E-09 5.765E-09 5.040E-09 WSW 8.102E-08 4.410E-08 2.971E-08 1.787E-08 1.244E-08 9.379E-09 7.442E-09 6.118E-09 5.163E-09 4.445E-09 3.888E-09 W 7.362E-08 4.039E-08 2.729E-08 1.647E-08 1.150E-08 8.698E-09 6.922E-09 5.706E-09 4.827E-09 4.165E-09 3.650E-09 WNW 1.087E-07 5.814E-08 3.870E-08 2.297E-08 1.588E-08 1.194E-08 9.459E-09 7.772E-09 6.557E-09 5.645E-09 4.939E-09 NW 9.039E-07 4.975E-08 3.367E-08 2.037E-08 1.424E-08 1.079E-08 8.595E-09 7.093E-09 6.006E-09 5.187E-09 4.550E-09 NNW 6.954E-08 4.177E-08 2.987E-08 1.936E-08 1.413E-08 1.103E-08 8.994E-09 7.559E-08 6.498E-09 5.684E-09 5.041E-09 N 7.033E-08 4.216E-08 3.010E-08 1.946E-08 1.419E-08 1.108E-08 9.028E-09 7.587E-09 6.523E-09 5.706E-09 5.061E-09 NNE 6.492E-08 4.041E-08 2.954E-08 1.967E-08 1.461E-08 1.155E-08 9.510E-09 8.057E-09 6.972E-09 6.134E-09 5.467E-09 NE 5.180E-08 3.212E-08 2.336E-08 1.544E-08 1.141E-08 8.987E-09 7.377E-09 6.234E-09 5.384E-09 4.728E-09 4.207E-09 ENE 5.786E-08 3.612E-08 2.639E-08 1.753E-08 1.298E-08 1.024E-08 8.412E-09 7.113E-09 6.146E-09 5.398E-09 4.805E-09 E 5.781E-08 3.546E-08 2.563E-08 1.681E-08 1.236E-08 9.700E-09 7.940E-09 6.694E-09 5.770E-09 5.058E-09 4.495E-09 ESE 6.554E-08 3.835E-08 2.701E-08 1.722E-08 1.248E-08 9.695E-09 7.881E-09 6.611E-09 5.675E-09 4.959E-09 4.394E-09 SE 7.530E-08 4.381E-08 3.074E-08 1.947E-08 1.401E-08 1.082E-08 8.747E-09 7.302E-09 6.241E-09 5.432E-09 4.797E-09 SSE 1.065E-07 6.296E-08 4.487E-08 2.923E-08 2.100E-08 1.621E-08 1.317E-08 1.105E-08 9.685E-09 8.630E-09 7.607E-09

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 36 of 79 Table 2.3-23 Annual Average Dispersion Factor (X/Q) - Plant Stack Releases Offgas Stack No Decay, Undepleted Corrected for Open Terrain Recirculation Annual Average CHI/Q (Sec/Meter Cubed) Distance in Miles Sector 0.250 0.500 0.750 1.000 1.500 2.000 2.500 3.000 3.500 4.000 4.500 S 2.115E-07 4.610E-07 2.388E-07 1.593E-07 1.288E-07 9.864E-08 7.790E-08 6.894E-08 6.157E-08 5.380E-08 4.765E-08 SSW 2.837E-07 7.831E-07 3.300E-07 1.700E-07 1.106E-07 9.136E-08 7.844E-08 6.159E-08 5.017E-08 4.336E-08 3.810E-08 SW 1.845E-08 3.655E-08 3.938E-08 3.921E-08 3.866E-08 4.136E-08 4.103E-08 3.536E-08 3.093E-08 2.878E-08 2.690E-08 WSW 2.433E-08 4.174E-08 4.948E-08 4.936E-08 4.708E-08 4.665E-08 4.328E-08 3.408E-08 2.772E-08 2.516E-08 2.304E-08 W 5.617E-09 2.206E-08 3.707E-08 4.484E-08 5.007E-08 5.511E-08 5.516E-08 4.752E-08 4.142E-08 3.487E-08 2.990E-08 WNW 1.006E-07 6.505E-08 6.450E-08 6.468E-08 6.394E-08 6.555E-08 6.264E-08 5.602E-08 5.023E-08 4.155E-08 3.514E-08 NW 1.418E-07 6.927E-08 5.869E-08 5.975E-08 5.870E-08 5.118E-08 4.319E-08 3.917E-08 3.548E-08 3.103E-08 2.750E-08 NNW 1.477E-07 8.592E-08 6.979E-08 6.209E-08 5.752E-08 4.724E-08 3.884E-08 3.244E-08 2.757E-08 2.381E-08 2.085E-08 N 1.476E-07 8.231E-08 6.138E-08 5.204E-08 4.793E-08 3.936E-08 3.252E-08 2.897E-08 2.597E-08 2.233E-08 1.949E-08 NNE 1.582E-07 1.080E-07 8.621E-08 6.771E-08 5.532E-08 4.327E-08 3.479E-08 2.873E-08 2.427E-08 2.089E-08 1.825E-08 NE 2.384E-07 4.483E-07 1.951E-07 9.784E-08 5.879E-08 4.452E-08 3.628E-08 2.946E-08 2.468E-08 2.114E-08 1.844E-08 ENE 1.202E-07 7.218E-08 5.321E-08 3.986E-08 3.219E-08 2.775E-08 2.422E-08 2.069E-08 1.795E-08 1.577E-08 1.402E-08 E 9.542E-08 6.545E-08 5.063E-08 3.953E-08 3.280E-08 2.701E-08 2.253E-08 1.910E-08 1.645E-08 1.437E-08 1.271E-08 ESE 1.608E-07 4.092E-07 1.913E-07 1.103E-07 7.750E-08 5.977E-08 4.803E-08 3.978E-08 3.375E-08 2.917E-08 2.560E-08 SE 1.908E-07 4.410E-07 2.167E-07 1.285E-07 8.914E-08 7.234E-08 6.044E-08 4.895E-08 4.075E-08 3.467E-08 3.003E-08 SSE 8.598E-08 9.415E-08 1.104E-07 1.062E-07 9.305E-08 7.625E-08 6.228E-08 5.167E-08 4.366E-08 3.751E-08 3.271E-08 Annual Average CHI/Q (Sec/Meter Cubed) Distance in Miles Sector 5.000 7.500 10.000 15.000 20.000 25.000 30.000 35.000 40.000 45.000 50.000 S 4.135E-08 2.465E-08 1.726E-08 1.073E-08 7.580E-09 5.763E-09 4.597E-09 3.794E-09 3.211E-09 2.771E-09 2.428E-09 SSW 3.303E-08 1.972E-08 1.388E-08 8.722E-09 6.223E-09 4.774E-09 3.840E-09 3.193E-09 2.721E-09 2.363E-09 2.082E-09 SW 2.325E-08 1.368E-08 9.507E-09 5.853E-09 4.106E-09 3.106E-09 2.467E-09 2.029E-09 1.712E-09 1.474E-09 1.288E-09 WSW 1.978E-08 1.140E-08 7.837E-09 4.777E-09 3.339E-09 2.521E-09 2.001E-09 1.645E-09 1.387E-09 1.194E-09 1.043E-09 W 2.603E-08 1.561E-08 1.093E-08 6.765E-09 4.750E-09 3.590E-09 2.848E-09 2.339E-09 1.970E-09 1.692E-09 1.477E-09 WNW 3.025E-08 1.750E-08 1.201E-08 7.268E-09 5.039E-09 3.775E-09 2.976E-09 2.431E-09 2.039E-09 1.746E-09 1.519E-09 NW 2.380E-08 1.405E-08 9.773E-09 6.016E-09 4.216E-09 3.185E-09 2.527E-09 2.076E-09 1.750E-09 1.504E-09 1.313E-09 NNW 1.836E-08 1.147E-08 8.248E-09 5.287E-09 3.804E-09 2.929E-09 2.359E-09 1.961E-09 1.669E-09 1.448E-09 1.274E-09 N 1.724E-08 1.091E-08 7.886E-09 5.067E-09 3.640E-09 2.795E-09 2.244E-09 1.859E-09 1.578E-09 1.365E-09 1.197E-09 NNE 1.616E-08 1.027E-08 7.432E-09 4.768E-09 3.419E-09 2.619E-09 2.099E-09 1.736E-09 1.471E-09 1.271E-09 1.114E-09 NE 1.633E-08 1.048E-08 7.707E-09 5.102E-09 3.756E-09 2.945E-09 2.407E-09 2.027E-09 1.745E-09 1.528E-09 1.357E-09 ENE 1.259E-08 8.389E-09 6.250E-09 4.166E-09 3.064E-09 2.394E-09 1.948E-09 1.633E-09 1.400E-09 1.221E-09 1.079E-09 E 1.136E-09 7.459E-09 5.508E-09 3.633E-09 2.653E-09 2.062E-09 1.671E-09 1.396E-09 1.193E-09 1.038E-09 9.153E-10 ESE 2.276E-08 1.471E-08 1.080E-08 7.091E-09 5.173E-09 4.020E-09 3.258E-09 2.723E-09 2.328E-09 2.026E-09 1.789E-09 SE 2.640E-08 1.648E-08 1.188E-08 7.676E-09 5.564E-09 4.310E-09 3.490E-09 2.915E-09 2.493-09 2.170E-09 1.917E-09 SSE 2.889E-08 1.823E-08 1.318E-08 8.505E-09 6.071E-09 4.643E-09 3.728E-09 3.091E-09 2.651E-09 2.316E-09 2.028E-09

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 37 of 79 Table 2.3-24 Relative Deposition per Unit Area (D/Q) - Reactor Building Vent Releases Reactor Building Vent Corrected for Open Terrain Recirculation Relative Deposition per Unit Area (M**-2) at Fixed Points by Downwind Sectors Distance in Miles Sector 0.25 0.50 0.75 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 S 8.092E-08 3.151E-08 1.761E-08 8.946E-09 3.746E-09 1.900E-09 1.135E-09 7.688E-10 5.686E-10 4.375E-10 3.536E-10 SSW 3,154E-08 1.295E-08 7.461E-09 3.869E-09 1.609E-09 8.979E-10 5.352E-10 3.563E-10 2.567E-10 1.965E-10 1.583E-10 SW 3.300E-08 1.377E-08 7.966E-09 4.147E-09 1.735E-09 9.762E-10 5.841E-10 3.907E-10 2.836E-10 2.443E-10 2.629E-10 WSW 2.055E-08 9.475E-09 5.706E-09 3.047E-09 1.281E-09 7.625E-10 4.563E-10 3.047E-10 2.200E-10 1.693E-10 1.459E-10 W 2.502E-08 1.056E-08 6.179E-09 3.225E-09 1.349E-09 7.579E-10 4.517E-10 3.013E-10 2.184E-10 1.685E-10 1.366E-10 WNW 5.235E-08 2.088E-08 1.177E-08 5.991E-09 2.437E-09 1.320E-09 7.849E-10 5.228E-10 4.494E-10 3.415E-10 2.717E-10 NW 6.974E-08 2.703E-08 1.504E-08 7.583E-09 2.914E-09 1.492E-09 9.284E-10 6.290E-10 4.606E-10 3.515E-10 2.816E-10 NNW 6.209E-08 2.360E-08 1.286E-08 6.399E-09 2.543E-09 1.281E-09 7.729E-10 5.142E-10 3.680E-10 2.787E-10 2.281E-10 N 7.209E-08 2.676E-08 1.434E-08 7.046E-09 2.712E-09 1.364E-09 8.121E-10 5.491E-10 4.003E-10 3.078E-10 2.480E-10 NNE 5.609E-08 2.149E-08 1.150E-08 5.643E-09 2.168E-09 1.092E-09 6.510E-10 4.314E-10 3.073E-10 2.310E-10 1.807E-10 NE 3.345E-08 1.350E-08 7.297E-09 3.601E-09 1.354E-09 6.904E-10 4.220E-10 2.798E-10 1.994E-10 1.498E-10 1.171E-10 ENE 3.671E-08 1.447E-08 7.753E-09 3.811E-09 1.429E-09 7.286E-10 4.441E-10 2.946E-10 2.098E-10 1.573E-10 1.227E-10 E 3.616E-08 1.380E-08 7.441E-09 3.674E-09 1.383E-09 7.040E-10 4.220E-10 2.802E-10 1.993E-10 1.490E-10 1.157E-10 ESE 7.702E-08 2.887E-08 1.555E-08 7.653E-09 2.863E-09 1.450E-09 8.654E-10 5.727E-10 4.064E-10 3.034E-10 2.352E-10 SE 9.530E-08 3.536E-08 1.903E-08 9.380E-09 3.520E-09 1.787E-09 1.108E-09 7.322E-10 5.211E-10 3.917E-10 3.070E-10 SSE 1.223E-07 4.534E-08 2.479E-08 1.237E-08 4.704E-09 2.399E-09 1.438E-09 9.546E-10 6.786E-10 5.068E-10 3.929E-10 Sector Distance in Miles 5.00 7.50 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 S 2.971E-10 1.641E-10 1.127E-10 6.546E-11 4.158E-11 2.793E-11 1.993E-11 1.486E-11 1.148E-11 9.147E-12 7.448E-12 SSW 1.323E-10 7.175E-11 4.870E-11 2.806E-11 1.782E-11 1.201E-11 8.596E-12 6.434E-12 4.986E-12 3.982E-12 3.250E-12 SW 2.105E-10 9.662E-11 5.959E-11 3.100E-11 1.909E-11 1.291E-11 9.317E-12 7.044E-12 5.505E-12 4.427E-12 3.634E-12 WSW 1.213E-10 6.451E-11 4.329E-11 2.471E-11 1.570E-11 1.062E-11 7.637E-12 5.741E-12 4.466E-12 3.580E-12 2.930E-12 W 1.154E-10 6.493E-11 4.495E-11 2.636E-11 1.680E-11 1.129E-11 8.061E-12 6.013E-12 4.646E-12 3.701E-12 3.013E-12 WNW 2.243E-10 1.166E-10 7.775E-11 4.381E-11 2.752E-11 1.845E-11 1.315E-11 9.804E-12 7.573E-12 6.024E-12 4.898E-12 NW 2.345E-10 1.257E-10 8.501E-11 4.874E-11 3.086E-11 2.075E-11 1.483E-11 1.109E-11 8.579E-12 6.843E-12 5.578E-12 NNW 1.892E-10 9.973E-11 6.677E-11 3.794E-11 2.401E-11 1.623E-11 1.168E-11 8.812E-12 6.897E-12 5.559E-12 4.588E-12 N 2.073E-10 1.125E-10 7.670E-11 4.423E-11 2.805E-11 1.887E-11 1.349E-11 1.008E-11 7.817E-12 6.237E-12 5.088E-12 NNE 1.461E-10 6.935E-11 4.359E-11 2.340E-11 1.477E-11 1.024E-11 7.634E-12 5.990E-12 4.874E-12 4.079E-12 3.502E-12 NE 9.447E-11 4.440E-11 2.767E-11 1.482E-11 9.433E-12 6.640E-12 5.023E-12 3.996E-12 3.291E-12 2.782E-12 2.410E-12 ENE 9.867E-11 4.581E-11 2.835E-11 1.505E-11 9.545E-12 6.726E-12 5.108E-12 4.086E-12 3.391E-12 2.886E-12 2.519E-12 E 9.243E-11 4.165E-11 2.516E-11 1.293E-11 8.073E-12 5.669E-12 4.320E-12 3.483E-12 2.928E-12 2.518E-12 2.228E-12 ESE 1.878E-10 8.431E-11 5.083E-11 2.596E-11 1.690E-11 1.118E-11 8.386E-12 6.635E-12 5.466E-12 4.613E-12 3.999E-12 SE 2.489E-10 1.199E-10 7.608E-11 4.100E-11 2.565E-11 1.747E-11 1.273E-11 9.745E-12 7.737E-12 6.321E-12 5.291E-12 SSE 3.136E-10 1.405E-10 8.434E-11 5.267E-11 3.273E-11 2.225E-11 1.622E-11 1.342E-11 1.457E-11 1.291E-11 1.047E-11

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 38 of 79 Table 2.3-25 Relative Deposition per Unit Area (D/Q) - Plant Stack Releases Offgas Stack Corrected for Open Terrain Recirculation Relative Deposition per Unit Area (M**-2) at Fixed Points by Downwind Sectors Distance in Miles Sector 0.25 0.50 0.75 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 S 8.898E-09 7.159E-09 5.968E-09 4.054E-09 1.953E-09 1.193E-09 8.045E-10 5.771E-10 4.319E-10 3.739E-10 3.038E-10 SSW 5.688E-09 4.432E-09 3.478E-09 2.236E-09 1.025E-09 6.119E-10 4.918E-10 3.371E-10 2.454E-10 1.925E-10 1.510E-10 SW 1.821E-09 1.550E-09 1.419E-09 1.038E-09 5.308E-10 3.322E-10 2.875E-10 2.048E-10 1.483E-10 1.123E-10 8.902E-11 WSW 2.098E-09 1.769E-09 1.596E-09 1.155E-09 5.895E-10 3.655E-10 3.111E-10 2.140E-10 1.561E-10 1.241E-10 9.717E-11 W 1.487E-09 1.348E-09 1.350E-09 1.050E-09 5.609E-10 3.570E-10 3.036E-10 2.255E-10 1.633E-10 1.236E-10 9.681E-11 WNW 4.723E-09 3.809E-09 3.189E-09 2.174E-09 1.051E-09 6.427E-10 5.445E-10 3.870E-10 2.798E-10 2.117E-10 1.658E-10 NW 5.707E-09 4.661E-09 3.991E-09 2.772E-09 1.361E-09 8.380E-10 5.676E-10 4.081E-10 3.058E-10 2.692E-10 2.172E-10 NNW 7.648E-09 5.852E-09 4.428E-09 2.743E-09 1.212E-09 7.115E-10 4.696E-10 3.330E-10 2.477E-10 1.909E-10 1.511E-10 N 7.157E-09 5.428E-09 4.032E-09 2.450E-09 1.060E-09 6.161E-10 4.043E-10 2.858E-10 2.122E-10 1.634E-10 1.294E-10 NNE 8.998E-09 6.737E-09 4.863E-09 2.863E-09 1.196E-09 6.828E-10 4.434E-10 3.115E-10 2.307E-10 1.774E-10 1.404E-10 NE 6.944E-09 5.171E-09 3.688E-09 2.141E-09 8.802E-10 4.980E-10 3.217E-10 2.254E-10 1.666E-10 1.280E-10 1.013E-10 ENE 6.176E-09 4.591E-09 3.263E-09 1.885E-09 7.710E-10 4.350E-10 2.805E-10 1.963E-10 1.451E-10 1.115E-10 8.822E-11 E 5.361E-09 4.032E-09 2.939E-09 1.749E-09 7.403E-10 4.253E-10 2.773E-10 1.952E-10 1.447E-10 1.113E-10 8.813E-11 ESE 6.035E-09 4.770E-09 3.848E-09 2.538E-09 1.192E-09 7.196E-10 4.824E-10 3.449E-10 2.577E-10 1.989E-10 1.575E-10 SE 8.324E-09 6.599E-09 5.355E-09 3.552E-09 1.676E-09 1.014E-09 6.806E-10 4.870E-10 3.640E-10 2.810E-10 2.225E-10 SSE 7.413E-09 6.241E-09 5.616E-09 4.058E-09 2.056E-09 1.282E-09 8.739E-10 6.305E-10 4.732E-10 3.660E-10 2.897E-10 Distance in Miles Sector 5.00 7.50 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 S 2.446E-10 1.114E-10 6.564E-11 3.308E-11 2.074E-11 1.466E-11 1.116E-11 8.927E-12 7.412E-12 6.290E-12 5.463E-12 SSW 1.217E-10 5.567E-11 3.292E-11 1.671E-11 1.053E-11 7.563E-12 5.836E-12 4.727E-12 3.969E-12 3.402E-12 2.986E-12 SW 7.162E-11 3.229E-11 1.879E-11 9.304E-12 5.797E-12 4.085E-12 3.138E-12 2.557E-12 2.174E-12 1.890E-12 1.690E-12 WSW 7.819E-11 3.531E-11 2.059E-11 1.022E-11 6.374E-12 4.485E-12 3.431E-12 2.776E-12 2.342E-12 2.020E-12 1.790E-12 W 7.788E-11 3.515E-11 2.044E-11 1.009E-11 6.253E-12 4.377E-12 3.335E-12 2.694E-12 2.270E-12 1.959E-12 1.739E-12 WNW 1.335E-10 6.042E-11 3.541E-11 1.776E-11 1.113E-11 7.835E-12 5.961E-12 4.770E-12 3.971E-12 3.378E-12 2.942E-12 NW 1.748E-10 7.937E-11 4.658E-11 2.335E-11 1.460E-11 1.028E-11 7.816E-12 6.248E-12 5.191E-12 4.410E-12 3.837E-12 NNW 1.222E-10 5.853E-11 3.613E-11 1.925E-11 1.225E-11 8.921E-12 6.812E-12 5.396E-12 4.378E-12 3.623E-12 3.046E-12 N 1.047E-10 5.019E-11 3.102E-11 1.657E-11 1.056E-11 7.732E-12 5.931E-12 4.702E-12 3.821E-12 3.165E-12 2.663E-12 NNE 1.137E-10 5.462E-11 3.383E-11 1.817E-11 1.163E-11 8.582E-12 6.621E-12 5.270E-12 4.294E-12 3.563E-12 3.002E-12 NE 8.210E-11 3.948E-11 2.448E-11 1.318E-11 8.450E-12 6.265E-12 4.847E-12 3.865E-12 3.153E-12 2.619E-12 2.207E-12 ENE 7.148E-11 3.439E-11 2.133E-11 1.149E-11 7.373E-12 5.474E-12 4.239E-12 3.382E-12 2.760E-12 2.293E-12 1.933E-12 E 7.135E-11 3.425E-11 2.120E-11 1.136E-11 7.261E-12 5.343E-12 4.113E-12 3.269E-12 2.661E-12 2.207E-12 1.858E-12 ESE 1.273E-10 6.078E-11 3.740E-11 1.979E-11 1.252E-11 8.999E-12 6.821E-12 5.363E-12 4.333E-12 3.575E-12 3.000E-12 SE 1.797E-10 8.583E-11 5.280E-11 2.792E-11 1.765E-11 1.268E-11 9.605E-12 7.548E-12 6.096E-12 5.029E-12 4.219E-12 SSE 2.339E-10 1.114E-10 6.831E-11 3.586E-11 2.255E-11 1.598E-11 1.200E-11 9.368E-12 7.532E-12 6.193E-12 5.185E-12

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 39 of 79 Table 2.3-26 Site Boundary X/Q and D/Q - Reactor Building Vent Releases Reactor Building Vent Corrected for Open Terrain Recirculation Specific Points of Interest Release Type of Sector Distance X/Q X/Q X/Q D/Q ID Location (Miles) (Meters) (Sec/Cub Meter) (Sec/Cub Meter) (Sec/Cub Meter) (Per Sq Meter)

No Decay 2.260 Day Decay 8.000 Day Decay

_______ ____________ __________ __________ _________ Undepleted Undepleted Depleted ______________

R Site Boundary S 0.34 547. 4.04E-06 4.03E-06 3.79E-06 5.36E-08 R Site Boundary SSW 0.32 515. 1.92E-06 1.92E--06 1.813-06 2.31E-08 R Site Boundary SW 0.32 515. 2.05E-06 2.05E-06 1.93E-06 2.43E-08 R Site Boundary WSW 0.35 563. 1.17E-06 1.17E-06 1.11E-06 1.43E-08 R Site Boundary W 0.48 772. 9.97E-07 9.96E-07 9.31E-07 1.11E-08 R Site Boundary WNW 0.68 1094. 1.33E-06 1.33E-06 1.24E-06 1.36E-06 R Site Boundary NW 0.43 692. 2.49E-06 2.49E-06 2.32E-06 3.34E-08 R Site Boundary NNW 0.53 853. 1.57E-06 1.57E-06 1.45E-06 2.17E-08 R Site Boundary N 0.51 821. 1.76E-06 1.75E-06 1.62E-06 2.60E-08 R Site Boundary NNE 0.58 933. 1.23E-06 1.22E-06 1.13E-06 1.72E-08 R Site Boundary NE 0.65 1046. 6.74E-07 6.73E-07 6.26E-07 9.13E-09 R Site Boundary ENE 0.83 1336. 5.55E-07 5.53E-07 5.14E-07 6.05E-09 R Site Boundary E 0.59 950. 9.09E-07 9.08E-07 8.39E-07 1.08E-08 R Site Boundary ESE 0.59 950. 1.81E-06 1.80E-06 1.67E-06 2.25E-08 R Site Boundary SE 0.61 982. 1.91E-06 1.91E-06 1.75E-06 2.62E-08 R Site Boundary SSE 0.43 692. 4.38E-06 4.38E-06 4.06E-06 5.65E-08

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 40 of 79 Table 2.3-27 Site Boundary X/Q and D/Q - Plant Stack Releases Offgas Stack Corrected for Open Terrain Recirculation Specific Points of Interest Release Type of Sector Distance X/Q X/Q X/Q D/Q ID Location (Miles) (Meters) (Sec/Cub Meter) (Sec/Cub Meter) (Sec/Cub Meter) (Per Sq Meter)

No Decay 2.260 Day Decay 8.000 Day Decay

_______ ____________ __________ __________ _________ Undepleted Undepleted Depleted ______________

R Site Boundary SSW 0.31 499. 6.50E-07 6.44E-07 6.48E-07 5.48E-09 R Site Boundary SW 0.33 531. 2.96E-08 2.96E-08 2.96E-08 1.75E-09 R Site Boundary SW 0.33 531. 2.96E-08 2.96E-08 2.96E-08 1.75E-09 R Site Boundary WSW 0.38 612. 3.54E-08 3.54E-08 3.54E-08 1.94E-09 R Site Boundary W 0.56 901. 2.49E-08 2.49E-08 2.46E-08 1.33E-09 R Site Boundary NW 0.78 1255. 5.70E-08 5.69E-08 5.61E-08 3.83E-09 R Site Boundary NW 0.53 853. 5.93E-08 5.92E-08 5.86E-08 4.55E-09 R Site Boundary NNW 0.61 982. 7.02E-08 7.02E-08 6.92E-08 5.12E-09 R Site Boundary N 0.59 950. 6.60E-08 6.60E-08 6.51E-08 4.83E-09 R Site Boundary N 0.63 1014. 6.33E-08 6.32E-08 6.23E-08 4.60E-09 R Site Boundary NNE 0.65 1046. 8.84E-08 8.83E-08 8.68E-08 5.49E-09 R Site Boundary ENE 0.78 1255. 4.96E-08 4.96E-08 4.86E-08 3.05E-09 R Site Boundary E 0.50 805. 6.12E-08 6.11E-08 6.06E-08 4.03E-09 R Site Boundary ESE 0.50 805. 3.42E-07 3.37E-07 3.37E-07 4.77E-09 R Site Boundary SSE 0.51 821. 9.11E-08 9.10E-08 9.02E-08 6.20E-09 R Site Boundary S 0.36 579. 4.78E-07 4.74E-07 4.77E-07 8.24E-09

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 41 of 79 2.4 Hydrology 2.4.1 Surface Water The Monticello sites lies about one-third of the river distance from Elk River, Minnesota to St. Cloud, Minnesota. Stream flow records of the Mississippi were kept at Elk River by the U.S. Geological Survey. The gauging station at Elk River was about 2500 feet downstream from the confluence of the Elk River (the only significant river entering the Mississippi River between the cities of Elk River and St. Cloud) and the Mississippi River. The Elk River Station has closed and the U.S. Geological Survey established a gauging station on the Mississippi River at St. Cloud in 1989.

In Table 2.4-1, the number of years of record, the average annual flow, the minimum recorded flow, the maximum recorded flow at each gauging station are tabulated. From this data, and with information on Elk River flows, the following flow statistics are estimated for the Mississippi River at the Monticello site:

Average Flow - 4600 ft3/sec Minimum Flow - 240 ft3/sec Maximum Flow - 51,000 ft3/sec The average velocity of flow at the site varies between 1.5 to 2.5 ft/sec for flows below 10,000 cfs.

Figure 2.4-1 is a flow duration curve for the Mississippi River at St. Cloud. From this curve, the flow at Monticello is expected to exceed 1100 ft3/sec 90% of the time, and 300 ft3/sec 99% of the time.

Based on past temperature records from the Whitney Steam Plant at St. Cloud (since retired and removed) the average river temperature for these summer months is 71°F.

Because of possible low stream flow conditions, and high natural river water temperatures, two cooling towers are included in the plant design in order to meet the standards of the Minnesota Pollution Control Agency. At times of extremely low flow, the plant operates on a closed cycle and the makeup requirement of about 54 ft3/sec is withdrawn from the river. At times of substantial flow and high ambient river temperature conditions, the cooling tower may be employed to control the temperature of discharged water.

All existing cooling towers are operated whenever the ambient river temperature measured at some point unaffected by the plants discharge is consistently at or above 20°C (68°F), except in the event the cooling towers are out of service due to equipment failure or performance of maintenance to prevent equipment failure.

The spring flood of 1965 exceeds all flood flows on record to date. Figure 2.4-2 shows the location of three flood stage boards which recorded this record flood. The stage at the site was about 916 ft msl for an estimated flow of 51,000 ft3/sec. Figure 2.4-3 shows the results of a flood frequency study. The 1000 year flood has an estimated stage of 920 ft msl.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 42 of 79 A study was made by the Harza Engineering Company to determine the predicted flood discharge flow and flood level at the site resulting from the maximum probable flood as defined by the U.S. Army Corps of Engineers (Policies and Procedures Pertaining to Determination of Spillway Capacities and Freeboard Allowances for Dams, Engineer Circular No. 1110-2-27, Enclosure 2, August 1, 1966 (Reference 33), Department of the Army, Office of the Chief of Engineers). Refer to Appendix G.

The probable maximum discharge was determined to be 364,900 ft3/sec and to have a corresponding peak stage of elevation 939.2 ft msl. The flood would result from meteorological conditions which could occur in the spring and would reach maximum river level in about 12 days. It was estimated the flood stage would remain above elevation 930.0 ft msl. for approximately 11 days.

The normal river stage at the plant site is about 905 ft msl. At a distance 1-1/2 mile upstream, the normal river elevation is about 910 ft msl, and at an equal distance downstream, the river is at 900 ft msl. Thus, the hydraulic slope is about 3-1/3 ft/mile.

2.4.2 Public Water Supplies 2.4.2.1 Surface Water The nearest domestic water supply reservoir with a free surface open to the air is the Minneapolis Water Works Reservoir. This reservoir is located north of Minneapolis, and is about 37 miles from the site. St. Paul uses a chain of lakes in its water supply system. These lakes, located north of St. Paul, are about 40 miles from the site.

The major supply of water for these reservoirs is the Mississippi River. The St.

Paul intake is about 33 river miles from the site and the Minneapolis intake is about 37 miles from the site. Harza Engineering Company made a study of pollutant dispersion of a slug waste in the river (Reference 35) between the Monticello Plant site and the Minneapolis and St. Paul water intakes. The results of this study were given in Answer to Question 3.3 of Amendment 4 and all of Amendment 8 of the Monticello Facility Description and Safety Analysis Report.

In the event of a contaminated Mississippi River, the Minneapolis water supply would be more critical than the St. Paul water supply, because Minneapolis has about a 2 day water supply and St. Paul a 4+week supply. Under the emergency, withdrawal of river water for the Minneapolis system could be suspended for about 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> without curtailment of non-essential use. This period could be extended to about 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> if non-essential use is curtailed.

Between 1960 and 1980, recreational use of the reach of river near Monticello has increased significantly.

River water is used for irrigation in a limited way between the site and Minneapolis. Twenty-six water appropriation permits have been issued by the Minnesota Department of Natural Resources for this reach of the river.

At Elk River, the river water is used for cooling purposes for an electric generating plant. The next industrial water user is Xcel Energy in north Minneapolis.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 43 of 79 2.4.2.2 Ground Water The outwash drift on both sides of the Mississippi in general yields large quantities of water. The water table under normal circumstances is higher than the river, thus ground water as well as run-off from rainfall feeds the river. The drift water usually is quite hard containing calcium, magnesium, and bicarbonates, with small amounts of sodium, potassium, sulfates, and chlorides.

Between the plant site and Minneapolis, the cities of Monticello, Elk River, Anoka, Coon Rapids, Champlin, Brooklyn Center, Brooklyn Park, and Fridley obtain groundwater from the bedrock formations for their domestic water supply as of 1981.

Numerous shallow wells supply water for residences and farms along the river terrace.

The closest public water supply wells are the city of Monticello wells. These wells are 16 inches in diameter and 250 feet deep. The 1200 gpm capacity is limited by the installed pumps. The wells have been tested to 2000 gpm. They are located in the main part of the city of Monticello.

The wells which obtain their water from the drift are recharged by local precipitation, while the wells which withdraw water from the bedrock are recharged by precipitation where the bedrock is at or near the land surface. The largest increment of recharge occurs during the spring thaw.

A review of Figure 2.5.2, Location of Original Borings, and Figure 2.5.5, Log of Borings, shows that the groundwater table in the area surrounding the plant site ranges from about 908 ft. msl to about 942 ft. msl, with the site itself at approximately 908 ft. msl. Since the normal river is at about 905 ft msl, groundwater flow is to the river. This usual case of groundwater flow to the river may not exist during floods.

2.4.3 Plant Design Bases Dependent on Hydrology Water movements passing the site are subject to large variations in the course of a year.

Plant design with respect to operation and liquid waste disposal takes into account large variations in water flow from less than 200 ft3/sec to flood level up to plant grade (about 930ft msl) which is well above record historical floods.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 44 of 79 2.4.4 Water Use Permits and Appropriations Relevant to Plant Operation The ground and surface water appropriations are pursuant to permits issued by the Minnesota Department of Natural Resources. The requirements for groundwater include domestic use for over 25 persons, industrial use to seal pumps in the plant intake structure and plant make up water. River water is required for condenser cooling, service water cooling, and plant makeup.

2.4.4.1 Site Active Water Ground Supply Wells Active Water Supply Well Summary MDH Unique Well Depth Principal Aquifer MDH Name Location Well No. (feet, bgs) Utilized Site Administration Building 197429 Well 1 80 Buried Outwash (SAB)

Well #11, West of Plant - Mt Simon 236025 Well 2 93 Plant Admin Building (PAB) Sandstone Plant Engineering Building Mt Simon 437214 Well 3 72 (PEB) Sandstone Well #12, West of Plant - Mt Simon 218039 Well 4 80 Plant Admin Building (PAB) Sandstone Security Training Facility 706817 Well 7 65 Buried Outwash (Double Wide Trailer)

Shipping and Receiving 731132 Well 8 73 Buried Outwash Warehouse Security Training Facility 786216 Well 9 38 Buried Outwash (Shooting Range Building) 2.4.4.2 Impacts on Ground Water Around Power Block Structures Wells 2, 3 and 4 are completed in the sandstone bedrock formation that is confined by a thick sequence of clayey glacial till at the well locations. Wells 1 and 8 are completed in buried sand and gravel outwash that appears to be confined by a thin layer of clayey glacial till. Wells 7 and 9, located east of the Plant at the Security Training Facility, are completed in relatively shallow, confined sand and gravel deposits. Site water supply Wells 7, 8, and 9 are completed in confined outwash deposits that are located either up-gradient or cross-gradient from the Reactor and Turbine Buildings at distances in excess of 1,750 feet. Based on usage of the wells, which is limited to sanitary and potable purposes, the wells are too far to measurably impact water levels near the Reactor and Turbine Buildings. Well 1 is located 625 feet upgradient of the Reactor and Turbine Buildings and is completed in a buried sand and gravel outwash aquifer. Well 3 is located side-gradient of the Reactor and Turbine Buildings, is completed in the remnant Mt. Simon Sandstone and is confined by clayey glacial till. Based on usage of these wells, which is limited to sanitary and potable purposes, and occasional landscape watering at Well 1, it is unlikely that pumping would affect groundwater flow in the vicinity of the Reactor and Turbine Buildings. Furthermore, it is even less likely that these wells would be capable of reversing gradients, capturing contaminated groundwater.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 45 of 79 Wells 2 and 4 are located in excess of 1,000 feet west of the Turbine and Reactor Buildings parallel to the Mississippi River in an upstream direction. The wells are situated in a side gradient direction with respect to the water table in the vicinity of the Plant. While it is anticipated that groundwater flow in the sandstone aquifer is also towards the river, consistent with regional flow patterns, the Water Monitoring System does not extend this far to the west. Observed flow directions in the deeper monitoring wells, which may correlate with the upper portion of the bedrock aquifer, are consistently towards the north and northeast, towards the Mississippi River, on the east side of the Plant.

Regarding the sustainability of water production from the high capacity wells (Wells 2 and 4), there is currently no reason to suspect that other groundwater use at the plant would adversely impact continued production from Wells 2 and 4 at the permitted levels. The wells have been in constant use since the plant began generating power in 1971. The wells are approximately 50 years old, and at some point, they may require major maintenance or replacement. Based on the available information and favorable operating history, the wells could be replaced in the general vicinity of the existing wells when replacement is needed. The new wells would be expected to have similar production characteristics as the existing wells.

Regarding potential effects of deep pumping on shallow groundwater flow, the best available information is from the water monitoring system which has been used to characterize shallow groundwater flow in detail since 2012 when the current monitoring well configuration was complete. This flow characterization has focused on the area of the Plant and has included hourly measurements of groundwater and river elevations to assess flow conditions in the shallow outwash aquifer and the upper portion of the deeper bedrock aquifer. Throughout this time period the high capacity wells have been in operation. Monitoring at the well nests suggests mostly upward vertical gradients north of the Turbine Building and mostly downward vertical gradient between the reactor building and turbine building; however, in both cases flow is predominantly towards the river.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 46 of 79 2.4.5 Surface Water Quality Water samples were taken upstream, downstream and at the plant discharge on February 28, 1972. The chemical analyses of the samples were as follows:

Upstream Downstream Plant Mississippi Mississippi Discharge P Alkalinity - ppm CaCO3 0 0 0 M Alkalinity - ppm CaCO3 170 169 165 Ammonia Nitrogen - ppm N 0.05 0.02 0.02 Organic Nitrogen - ppm N 0.933 0.61 0.65 Nitrate Nitrogen - ppm N 0.28 0.37 0.37 Nitrite Nitrogen - ppm N 0.001 0.003 0.002 Chloride - ppm 1.4 0.9 1.0 Sulfate - ppm SO4 7.8 6.6 7.3 Color - Units 35 35 35 Turbidity - JTU 3.9 2.0 2.5 Total Hardness - ppm CaCO3 177 178 178 Calcium Hardness - ppm CaCO3 122 114 122 pH 7.5 7.9 7.8 Total Solids - ppm 288 272 247 Non-Filterable Solids - ppm 12 3 5 Dissolved Solids - ppm 276 269 242 Fixed Non-Filterable Solids - ppm 8 2 3 Volatile Solids - ppm 4 1 2 Total Soluble Phosphorus - ppm P 0.035 0.026 0.024 Total Chlorophyll - mg/m3 5.7 1.5 1.6 Conductivity - mmhos (25°C) 364 357 364 Temp. °C 0.2 8.3 15.5 D.O. mg/l 8.4 8.6 8.2 BOD mg/l 0.9 1.0 0.9 Cooling towers not operating Paper pulp (Sartell and Little Falls) facilities were located upstream of the plant when the study was done. Sewage treatment facilities (St. Cloud and others) are located upstream of the plant.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 47 of 79 2.4.6 Environmental Assessment An environmental assessment (EA) of MNGP operation at Extended Power Uprate (EPU) conditions was submitted to the NRC (Reference 45, Enclosure 4). The assessment was subsequently updated by Reference 47. Approval of the updated EA was completed in May 2013 (Reference 46). The assessment includes the environmental effect of plant water use and cooling tower operation at EPU conditions.

Table 2.4-1 Mississippi River Flows at Elk River and St. Cloud, Minnesota Location Elk River1 St. Cloud2 Number of Records, years 38 40 Average Annual Flow, ft3/sec 5,260 4,360 Minimum Recorded Flow, ft3/sec 278 220 Maximum Recorded Flow, ft3/sec 49,200 46,780 (4-12-52) (4-15-65)

1. Data from Hydrologic Atlas of Minnesota, Bulletin #10, Minnesota Department of Conservation, April 1959, at U.S. Geological Survey, Recorder 2755. Station discontinued October 31, 1957 (Reference 36).

2. Data from Northern States Power Company records from July 1, 1925, to December 31, 1965, at Whitney Steam Plant, St. Cloud, Minnesota (Reference 37).

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 48 of 79 2.5 Geology and Soil Investigation 2.5.1 General Dames and Moore, consultants in applied earth sciences, analyzed the geology and foundation conditions of the plant site.

2.5.2 Regional Geology Rocks dating as early as Precambrian time underlie the region of Minnesota which includes the plant site. Pleistocene glaciation, probably less than 1,000,000 years in age, as well as recent alluvial deposition have mantled the older rocks with a variety of unconsolidated materials in the form of glacial moraines, glacial outwash plains, glacial till, and river bed sediments. This cover of young soil rests upon a surface of glacially-carved bedrock consisting of sandstone and shale strata underlain by deeply weathered granite rocks. Volcanics also form portions of the bedrock sequence in certain areas. The bedrock surface is irregular and slopes generally to the east or southeast.

The geologic column showing the age relationships of the various bedrock units and surficial deposits of the region is presented in Table 2.5-1. Figure 2.5-1a and 2.5-1b show the regional extent of the consolidated formations.

The principal structural feature in this part of Minnesota is a deep trough formed during Precambrian time in the granite and associated crystalline rocks. This basin extended from Lake Superior into Iowa, and provided a site for the deposition of thick sequences of Precambrian and later Paleozic sediments and volcanics. Strata of Paleozoic age are now exposed along the southern half of the structural trough. In the Minneapolis-St.

Paul area, they form a circular basin containing artesian groundwater.

The ice fronts or glacial lobes advanced across this region during the last stage of glaciation, named the Wisconsin Stage. One lobe came from the general area of Lake Superior and deposited terminal moraines immediately south of the present course of the Mississippi River. A later ice front advanced across the area from the southwest, overriding the earlier moraines. Erosion of these glacial sediments by the Mississippi River has been active since the final retreat of the ice.

The present course of the Mississippi has no relation to the streams that flowed through the area prior to glaciation. There are therefore, old river channels which cross the region and which may be substantially deeper than the present river channel.

A major fault system of Precambrian age has been inferred from regional geophysical surveys. This fault system is associated with the Precambrian structural trough. The major movements along this fault system, which amount to thousands of feet, appear to have been restricted to Precambrian time. Minor fault displacements occurred during the Paleozoic era, but faulting within the last few million years is not in evidence.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 49 of 79 2.5.3 Site Geology The site occupies a bluff which forms the southwest bank of the Mississippi River.

Several flat alluvial terraces comprise the main topographical features on the property.

These terraces lie at average elevations of 930 and 918 ft msl and in general, slope very slightly away from the river.

The present surface drainage of the immediate plant site area is mainly to the southwest, away from the river. Surface run-off will tend to collect in the depression at the south end of the terrace where it is bounded by higher ground, then flow easterly to the river.

At the time of start of construction, most of the site was under cultivation, which has since been discontinued, with the remainder of the site area covered by scattered low brush and small trees.

The pattern of the present meander system suggests that the channel to the south of the islands in the river is now the main channel. It is possible that the channel to the north of the islands may eventually be abandoned. If this occurs during the lifetime of the plant it probably will result in increased erosion along the bluff at the plant site; however, this erosion is not a matter of concern because the actual amount would be small and not interfere with any structures.

The site is located on the extreme western edge of the Precambrian structural trough previously discussed under Regional Geology. A well in the town of Monticello about 2-3/4 miles east of the site which was drilled to a depth of 500 ft did not encounter granite. Other well information generally indicates that 150 to 200 ft of unconsolidated alluvium and drift overlies sandstone and red shale of unknown thickness at Monticello.

All the rock and soil units present at the site therefore slope eastward and thicken toward the sedimentary basin and its artesian groundwater aquifers.

Decomposed granite and basic rocks of Precambrian age comprise the oldest formation at the site, within the depth investigated. This material lies below the ground surface at a depth of about 75 to 122 ft. (See Figures 2.5-1a through 2.5-5) Resting directly upon the weathered Precambrian crystalline rocks is approximately 10 to 15 ft of medium-grained quartz sandstone which, in general, is moderately well cemented. The upper surface of underlying rock can support unit foundation loads up to 15,000 pounds per square foot.

Above the sandstone is a series of alluvial strata about 50 ft thick which consists predominately of clean sands with gravel, as well as a few layers of clay and glacial till.

This alluvial sequence represents successive depositions of glacial outwash, moraine, and more recently, sediments laid down by the Mississippi River. During its history this river has meandered as much as 1-1/2 miles south of its present channel.

The distribution of the unconsolidated materials in the locality of the site is shown on Figure 2.5-1b.

The nearest known or inferred fault is the Douglas fault, located approximately 23 miles southeast of the site as shown on Figure 2.5-1a. It is probable that the site has not experienced any activity within recent geologic times.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 50 of 79 2.5.4 Groundwater Large supplies of groundwater are available from the Mississippi River sediments, the glacial deposits, and the underlying sandstones in the area. Most of the private wells in the area are shallow, and penetrate either the river alluvium or the glacial deposits. The town of Monticello derives its water supply from a well approximately 237 ft deep which is believed to penetrate sandstone aquifers. The communities of Big Lake, Albertville, and Elk River also recover water from this formation.

The general path of deep groundwater flow is to the southeast across the region surrounding the site for the plant. The regional gradient, therefore, broadly parallels the trend of the topography and the principal surface drainage. Groundwater at shallower depths moves toward the Mississippi River or its tributaries at variable gradients depending on local conditions.

The water table beneath the low terraces which border the Mississippi River usually lies at about river elevation and slopes very slightly toward the river during periods of normal stream flow. Such is the case at the site.

Movement of groundwater takes place within the three principal rock and soil materials at the site. In the decomposed, clayey granitic rocks, which are very low in permeability relative to the overlying materials, the rate of ground water movement is extremely slow.

2.5.5 Foundation Investigation The location of the principal structures including the turbine and reactor buildings, intake structure, stack and diesel building and soil borings are shown in Figures 2.5-1a through 2.5-5.

Dynamic soil tests were not considered because the probability of liquefaction is very low under the cyclic loadings produced by the 1952 Taft earthquake (refer to Section 2.6.3), considering the density of the sand and overburden pressure.

Sands which are typically vulnerable to liquefaction are saturated, under low confining pressures, and have standard penetration test values of about N=5. Laboratory studies by Seed and Lee (Liquefaction of Saturated Sands during Cyclic Loading, Journal Soil Mechanics and Foundation Division, ASCE, November 1966, Volume 92, No. SM6)

(Reference 38) demonstrate that sands denser than the critical void ratio can be made to liquefy under cyclic loading. Consequently liquefaction has an extremely low statistical possibility in a cemented sand with standard penetration test values of N=80 or more, and could only occur under a very large number (e.g., 10,000) of very high stress cycles. The number of stress cycles that could be expected due to the Taft earthquake is estimated to be less than 1000 cycles.

2.5.6 Conclusions No unusual features of the site geology are evident. Underlying formations are adequate for foundation for the plant structures.

The geology and soil conditions have been investigated and found stable.

Consequently, no special plant design features pertaining to the site geology were necessary.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 51 of 79 Table 2.5-1 Geologic Formations in the General Area of the Site Geologic Age Geologic Name Description Remarks ERA Period Cenozoic Quaternary Recent Deposits Unconsolidated clay, silt, sand, and Largely Mississippi gravel River deposits Pleistocene Unconsolidated clay, silt, sand, gravel, Largely from Superior and boulders deposited as till, outwash, and Grantsburg lobes lake deposits, & loess of Wisconsin glaciation Paleozoic Cambrian Franconia Formation Sandstone and shale, some aquifer May not be present in (St. Croix Series) zones immediate area of site Dresbach Formation Sandstone, siltstone and shale, May not be present in (St. Croix Series) aquifer zone immediate area of site Precambrian Keweenawan Hinckley Formation Sandstone Thin in the immediate area of the site. An important aquifer where sufficiently thick Red Clastic Series Sandstone and red shale Probably not present in immediate area of site Volcanics Mafic lava flows with thin layers of Probably not present tuff and breccia in immediate area of site Granite and Present at site Associated Intrusives

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 52 of 79 2.6 Seismology 2.6.1 General John A. Blume, Associates, analyzed the seismology of the plant site. A copy of the Blume report is included in Appendix A.

2.6.2 Seismic History In Table 2.6-1 are listed numerically the earthquakes in the general region in and around Minnesota. Those more applicable to the site are plotted on Figure 2.6-1. The earliest earthquake on record occurred in 1860 in central Minnesota; thus over 100 years of records exist. During that period, earthquakes have had little effect at the site. Since compilation of Table 2.6-1, there has been no observed evidence of seismic activity in the plant area.

2.6.3 Faulting in Area The nearest known or inferred fault - the Douglas Fault - is 23 miles southeast of the site (Figure 2.5-1a). According to referenced geological information, there is no indication that faulting has affected the area of the site in the last few million years. The major fault system of Precambrian age, which is associated with the Precambrian structural trough, is seen on Figure 2.6-2. Major movements of thousands of feet along this system appear to have been restricted to Precambrian time, with minor displacements having occurred during the Paleozoic era. Faulting within recent geologic time is not in evidence.

Richters Seismic Regionalization Map (Figure 2.6-3) shows the area of the site in a probable maximum intensity of VIII, Modified Mercalli.

This intensity has been based on the areas relationship to the Canadian shield. Stable shields in other continents are usually fringed by belts of moderate seismicity, with occasionally large earthquakes. Historically, this area is too young to prove or disprove such seismic activity. The Modified Mercalli scale is explained in Table 2.6-2.

The Coast and Geodetic Surveys Seismic Probability Map of the United States (Figure 2.6-4) assigns the area to Zone 0 - no damage.

It is considered that neither the regionalization nor the probability map is satisfactory in determining a proper seismic factor if considered alone. Each, however, is based on judgment and fact which, when weighed with other data, become more meaningful. In the case at hand, the assignment of an VIII as the largest probable intensity for the general area must be tempered by the fact that the intensity at or near the underlying sandstone will be much less than that experienced in areas of less competent material, where invariably the maximum damage is sustained.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 53 of 79 Earthquakes can and do occur in this region away from faults, and probably result from residual stresses due to recent glaciers. A quake similar to No. 12 and 24 in Table 2.6-1 was postulated near the site and using the dynamic response data obtained insitu, the Taft earthquake of July 21, 1952, North 69 West component with an applied factor of 0.33 was selected as best representative for the design earthquake. Figure 2.6-5 shows single-mass spectra when averaged.

2.6.4 Design Criteria Design criteria which utilize this earthquake record are discussed in Section 12.

Section 12 also gives specific design information related to the seismic analysis of the building and equipment.

2.6.5 Seismic Monitoring System The Seismic Monitoring System annunciates the occurrence and records the severity of significant seismic events.

The system is composed of three subsystems: the relatively simple annunciators and peak-recording accelerometers, and the more sophisticated acceleration sensors located in the drywell, on the refueling floor and in the seismic shed (located to the north of the warehouse).

Each of the peak-recording accelerometers is a self-contained unit. The sensing mechanism is a permanent magnet stylus attached to the end of a torsional accelerometer. Low frequency accelerations cause the magnet to erase pre-recorded lines on a small (approximately 1/4 inch square) piece of magnetic tape. Because an erasure is permanent, only the peak acceleration that the tape has been subjected to can be deduced when the tape is developed. Each peak recording accelerometer unit contains three torsional accelerometers and magnetic tapes - one each for longitudinal, transverse, and vertical accelerations.

The magnetic tapes can be removed from the accelerometers, developed, and evaluated by plant personnel for a rapid determination of the severity of a seismic disturbance.

The accelerograph recording system gives a more detailed record of a disturbance than the peak recording accelerometers - it records accelerations in three directions (longitudinal, transverse, and vertical, as above) at each of the three sensor locations on magnetic tape cartridges. This system has five major components: trigger, three sensors, and the recording and control equipment. When the trigger (located in the No.

12 125 Vdc battery room) senses the beginning of a seismic disturbance, (an acceleration .01 g), it initiates the system power-on sequence and causes the EARTHQUAKE alarm to annunciate in the control room. The recorder then converts the nine analog acceleration signals (three sensors with three directions/sensor) into frequency modulated tones and records them on the magnetic tapes (one for each triaxial sensor). The recorder will run for 10 seconds after each trigger signal, up to a maximum of 30 minutes. The resulting tape gives a detailed record of the disturbance, but must be sent off-site to be fully processed.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 54 of 79 The control room EARTHQUAKE annunciator is also initiated by any seismic switch of the Seismic Annunciator System. In addition to this, there are two more alarms initiated by the Seismic Annunciator System. The first of these is the Operational Basis Earthquake (OBE) alarm which annunciates when its seismic switch senses an acceleration .03g. The second is the Design Basis Earthquake (DBE) alarm, which annunciates when its switch senses an acceleration .06g. These two switches do not activate the accelerograph recording system.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 55 of 79 Table 2.6-1 Seismic History of the Region (Page 1 of 2)

Location N W Intensity No. Date Place Lat. Long. (M.M) Remarks

• 1 1860 Central Minn. - - Unknown Felt over 3,000 square miles 2 10/9/1872 Sioux City, Iowa 42.7 97.0 V Felt over 140,000 square miles 3 11/15/1877 East Nebraska 41.0 97.0 VII Felt over 140,000 square miles.

4 7/28/1902 East Nebraska 42.5 97.5 V Felt over 35,000 square miles.

5 7/26/1905 Calumet, Mich. 47.3 88.4 VII Felt over 16,000 square miles.

6 5/9/1906 Washabaugh County, S. D. 43.0 101.0 VI Felt over 8,000 square miles.

7 5/26/1906 Keweenaw Peninsula, Michigan 47.3 88.4 VIII Felt over 1,000 square miles.

8 5/15/1909 Canada, felt to South 50.0 105.00 VIII Felt over 500,000 square miles.

9 5/26/1909 Dixon, Illinois 42.5 89.0 VII Felt over 40,000 square miles.

10 10/22/1909 Sterling, Illinois 41.6 89.8 IV-V 11 6/2/1911 South Dakota 44.2 98.2 V Felt over 40,000 square miles.

12 9/3/1917 Minnesota 46.3 94.5 VI Felt over 10,000 square miles.

• 13 2/28/1925 Canada 48.2 70.8 VIII Felt over 2,000,000 square miles.

14 10/6/1929 Yankton, S. Dakota 42.8 97.4 V (est.)

15 1/17/1931 White Lake, S. Dakota 43.8 98.7 V (est.)

• 16 11/12/1934 Rock Island & Moline, Illinois Davenport, Iowa 41.4 90.5 V 17 3/1/1935 Eastern Nebraska 40.3 96.2 VI Felt over 50,000 square miles.

• 18 11/1/1935 Canada 46.8 79.1 IX and over Felt over 1,000,000 square miles, felt in Minnesota.

19 11/1/1935 Egan, S. Dakota 44.0 96.6 V (est.)

20 10/1/1938 Sioux Falls, S. Dakota 43.5 96.6 V Felt over 3,000 square miles.

• Indicates epicenter not plotted on map.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 56 of 79 Table 2.6-1 Seismic History of the Region (Page 2 of 2)

Location N W Intensity No. Date Place Lat. Long. (M.M) Remarks 21 1/28/1939 Detroit Lake, Minn. 46.9 95.5 V (est.)

22 6/10/1939 Fairfax, S. Dakota 43.1 98.8 VI (est.)

23 7/23/1946 Wessington, S. Dakota 44.5 98.7 VI (est.)

24 5/6/1947 Milwaukee Area 42.9 87.9 VII Felt Sheboygan to Kenosha, Wis.

25 2/15/1950 Alexandria, Minn. 45.7 94.8 V-VI (est.)

26 1/6/1955 Hancock, Michigan 47.3 88.4 V 27 12/3/1957 Mitchell, S. Dakota 43.8 98.0 V 28 1/12/1959 Doland, S. Dakota 44.9 98.0 V 29 12/31/1961 W. Pierre, S. Dakota 44.4 100.5 VI

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 57 of 79 Table 2.6-2 Modified Mercalli Intensity Scale of 1931 (Abridged)

I. Not felt except by a very few under especially favorable circumstances II. Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended objects may swing.

III. Felt quite noticeably indoors, especially on upper floors of buildings, but many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibration like passing of truck. Duration estimated.

IV. During the day felt indoors by many, outdoors by few. At night some awakened. Dishes, windows, doors disturbed, walls make creaking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.

V. Felt by nearly everyone, many awakened. Some dishes, windows, etc., broken; a few instances of cracked plaster; unstable objects overturned. Disturbance of trees, poles, and other tall objects sometimes noticed. Pendulum clocks may stop.

VI. Felt by all, many frightened and run outdoors. Some heavy furniture moved; a few instances of fallen plaster or damaged chimneys. Damage slight.

VII. Everybody runs outdoors. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable in poorly built or badly designed structures; some chimneys broken. Noticed by persons driving motor cars.

VIII. Damage slight in specially designed structures; considerable in ordinary substantial buildings with partial collapse; great in poorly built structures. Panel walls thrown out of frame structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water.

Disturbs persons driving motor cars.

IX. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb; great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken.

X. Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations; ground badly cracked. Rails bent. Landslides considerable from river banks and steep slopes. Shifted sand and mud. Water splashed (slopped) over banks.

XI. Few, if any (masonry), structures remain standing. Bridges destroyed. Broad fissures in ground. Underground pipe lines completely out of service. Earth slumps and land slips in soft ground. Rails bent greatly.

XII. Damage total. Waves seen on ground surfaces. Lines of sight and level distorted.

Objects thrown upward into the air.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 58 of 79 2.7 Radiation Environmental Monitoring Program (REMP) 2.7.1 Program Design and Data Interpretation The purpose of the Radiation Environmental Monitoring Program (REMP) at the Monticello Nuclear Generating Plant is to assess the impact of the plant on its environment (References 7 and 42). For this purpose, samples are collected from the air, terrestrial, and aquatic environments and analyzed for radioactive content. In addition, ambient gamma radiation levels are monitored by thermoluminescent dosimeters (TLDs).

Sources of environmental radiation include the following:

a. natural background radiation arising from cosmic rays and primordial radionuclides;

b. fallout from atmospheric nuclear detonations;

c. releases from nuclear power plants.

In interpreting the data, effects due to the Plant must be distinguished from those due to other sources. To accomplish this, the program uses the control-indicator concept suggested by NRC Guidelines.

2.7.2 Program Description The sample types and locations included in the current Radiation Environmental Monitoring Program (REMP) at the Monticello Nuclear Generating Plant are listed in the Offsite Dose Calculation Manual (ODCM, Reference 8).

Sample locations are chosen to provide measurements of radiation and of radioactive materials in those exposure pathways and for those radionuclides which lead to the highest potential radiation exposures off site. The technique for establishing sample locations conforms to guidance provided by the NRC.

The air environment is monitored by continuous air samplers which filter out airborne radioactive particulates and adsorb airborne radioiodine.

Ambient gamma radiation is monitored at thermoluminescent dosimeter (TLD) stations located in a circular array around the plant. TLD stations are also located around the sites Independent Spent Fuel Storage Installation (ISFSI).

The terrestrial environment is monitored through samples of groundwater and locally produced food products.

The aquatic environment is monitored through sampling sediment and water from the Mississippi River at locations upstream and downstream of the plant. Drinking water from the city of Minneapolis, which is drawn from the river, is also sampled.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 59 of 79 2.7.3 Interlaboratory Comparison Program Monticello participates in an Interlaboratory Comparison Program to ensure the precision and accuracy of radioactivity measurements of environmental samples. This program is described in the ODCM.

2.8 Ecological and Biological Studies On August 26, 1977 the Minnesota Pollution Control Agency, the permitting agency under the U. S. Environmental Protection Agency, issued the National Pollution Discharge Elimination System (NPDES) Permit No. MN0000868 covering the Monticello Nuclear Generating Plant. This permit is reissued with any modifications required every 5 years. The NPDES effluent limitations and monitoring requirements, thermal studies and ecological monitoring requirements provide appropriate protection for the environment. There are no ecological or biological monitoring requirements under NRC jurisdiction. Pre-operational and early operational ecological and biological studies are described in the FSAR.

An environmental assessment (EA) of MNGP operation at Extended Power Uprate (EPU) conditions was submitted to the NRC (Reference 45, Enclosure 4). The assessment was subsequently updated by Reference 47. Approval of the updated EA was completed in May 2013 (Reference 46). The assessment evaluated the continued applicability of ecological and biological studies for EPU operation.

2.9 Consequences of Hypothetical Local Catastrophes 2.9.1 Toxic Chemical Spills Due to the toxicity of commonly used chemicals, which may be transported near the Monticello Nuclear Generating Plant by railroad or highway, a survey was performed to predict which chemicals may become hazardous in the event of a spill. The analysis was performed in conformance with the guidance set forth by Regulatory Guide 1.78 (Reference 40) and NUREG 0570 (Reference 41). The analysis results were submitted to the NRC for review as required by NUREG 0737, Item III D.3.4 (References 10, 11, 12, 13).

A new toxic chemical survey (Reference 16) was performed in 1993 which identified toxic chemicals in sufficient quantities stored on-site, stored in the vicinity of the site, or shipped near the plant at sufficient frequency to warrant further evaluation. For chemicals meeting these criteria, evaluation indicated that Control Room personnel would have at least two minutes to don breathing apparatus before incapacitation limits were exceeded. The results of the 1993 survey and evaluation were submitted (References 17 and 43) and approved by the NRC (Reference 44).

In 1998, the list of postulated spills was reviewed. The 1993 methodology was used to determine event duration based on concentration level outside the air intake. These event durations were then used to size the Control Room Breathing Air System (see Section 10.3.11).

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 60 of 79 In 2002, an update to the 1998 study using the most recent information available for on-site and off-site chemical sources was performed. This update did not identify any new threat to the site.

In 2008 an update to the 2002 study was completed with no additional threat identified.

In 2014 an update to the 2008 study was completed (EC 23401) using more current on-site and off-site chemical source listings obtained from BNSF, Sherburne & Wright Counties, plant walkdowns, warehouse inspections, and site chemical listings. This survey found no new threats that would challenge Control Room Habitability in event of a postulated accident.

In 2020 an update to the 2014 study was completed (Eval 608000000603) using current on-site and off-site chemical source listings obtained from BNSF, Sherburne & Wright Counties, site walkdowns, and chemical listings. This survey identified peracetic acid as a new chemical stored within five miles that could affect the site during a postulated spill.

The impact was bound by current procedures.

2.10 References

1. Deleted.

2. Tornado Probabilities, H C S Thom, Office of Climatology, U.S. Weather Bureau, published in Monthly Weather Review, October-November 1963, 91, Nos. 10-12, Pages 730-736.

3. General Electric Report, APED-5696, Tornado Protection for Spent Fuel Storage Pool, D R Miller and W A Williams, November 1968.

4. Air Pathway Exposure Model Validation Study at the Monticello Nuclear Generating Plant, J E Partridge, et al., Eastern Environmental Radiation Facility, Montgomery, Alabama and C B Nelson, Environmental Analysis Division, U.S.

Environmental Protection Agency.

5. General Electric Report, NEDO-21159-1, Airborne Releases from BWRs for Environmental Impact Evaluations, Amendment 1, T R Marrero, September 1976.

6. NUS Report, Monticello Short Term (Accident) Diffusion Factors, D A Sullivan, Environmental Safeguards Division, Rockville, Maryland, August 1976.

7. NSP (L O Mayer) letter to the NRC, License Amendment Request - Radioactive Effluent Technical Specification, dated May 1, 1979.

8. Monticello Nuclear Generating Plant, Offsite Dose Calculation Manual (ODCM).

9. NSP (L O Mayer) letter to the NRC (D L Zieman), MNGP Appendix I Filing, dated June 4, 1976.

10. Bechtel Report, Monticello Nuclear Generating Plant Main Control Room, Toxic Chemical Study, January 1981.

11. NSP (D M Musolf) letter to the NRC, Revision 1 to License Amendment Request dated April 3, 1984, dated August 17, 1984.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 61 of 79

12. NRC (J A Zwolinski) letter to NSP (D M Musolf), Request for Additional Information - Control Room Ventilation System (TAC 56977), dated November 5, 1986.

13. NSP (D M Musolf) letter to the NRC, Revision 3 to License Amendment Request dated April 3, 1984, dated February 19, 1987.

14. NUREG/CR-2919, XOQDOQ, Computer Program for the Meteorological Evaluation of Routine Effluent Release at Nuclear Power Stations, September 1982.

15. KLD Engineering, P.C., "Monticello Nuclear Generating Plant Development of Evacuation Time Estimates", dated November 2012.

16. Tenera Report, Monticello Nuclear Generating Plant Control Room Habitability -

Toxic Chemical Study, Final Report, June 11, 1993.

17. NSP (R O Anderson) letter to the NRC, License Amendment Request, Removal of Chlorine Detection Requirements and Changes to Control Room Ventilation System Requirements, dated November 30, 1993.

18. Housing and Home Finance Agency (HHFA) study conducted in 1952.

19. American Telephone and Telegraph Company study, conducted 1917-18 to 1924-25.

20. Edison Electric Institute study, conducted 1926-27 to 1937-38.

21. Association of American Railroads study, conducted 1928-29 to 1936-37.

22. Quartermaster Research and Engineering Command Study, U.S. Army, 1959.

23. Rainfall Intensity - Duration - Frequency Curves, U.S. Weather Bureau Technical Paper No. 25, (1955).

24. Climatological Data with Comparative Data, Minneapolis - St. Paul, Minnesota, 1953-1956, U.S. Weather Bureau (2 publications).

25. Climatological Data with Comparative Data, St. Cloud, Minnesota 1953 - 1965, U.S. Weather Bureau (2 publications).

26. Climatography of the United States, No. 86-17, Minnesota, U.S. Weather Bureau.

27. Local Climatological Data with Comparative Data, 1965, U.S. Weather Bureau.

28. Snow Load Studies, Housing Research Paper 19, Housing and Home Finance Agency, 1952.

29. Glaze, Its Meteorology and Climatology, Geographical Distribution and Economic Effects, Quartermaster Research and Engineering Center, 1959.

30. Climatography of the United States, No. 60-21, Minnesota, U.S. Weather Bureau.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 62 of 79

31. Mean Annual Tornado Frequency figures published by the U.S. Department of Commerce, Weather Bureau.

32. Deleted.

33. Department of the Army, Office of the Chief of Engineers, Engineer Circular No.

1110-2-27, Policies and Procedures Pertaining to Spillway Capacities and Freeboard Allowances for Dams, August 1, 1966 .

34. Deleted.

35. Harza Engineering Company study of pollutant dispersion of a slug waste in the Mississippi River.

36. Hydrologic Atlas of Minnesota, Bulletin #10, Minnesota Department of Conservation, April 1959, at U.S. Geological Survey, Recorder 2755.

37. Northern States Power Company records from July 1, 1925, to December 31, 1965, at Whitney Steam Plant, St. Cloud, Minnesota.

38. Liquefaction of Saturated Sands during Cyclic Loading, Laboratory studies by Seed and Lee, ASCE, Journal, Soil Mechanics and Foundation Division, Volume 92, No. SM6, November 1966.

39. Regulatory Guide 1.23, Meteorological Programs in Support of Nuclear Power Plants, Proposed Revision 1, September 1980.

40. Regulatory Guide 1.78, Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During A Postulated Hazardous Chemical Release, June 1, 1974.

41. NUREG 0570, Toxic Vapor Concentrations in the Control Room Following a Postulated Accidental Release, June 1, 1979.

42. NRC (D B Vassallo) letter to NSP (D M Musolf), Amendment 15 to Facility Operating License DPR-22 dated December 17, 1982.

43. NSP (R O Anderson) letter to the NRC, Additional Information to Support License Amendment Request dated November 30, 1993, dated June 30, 1994.

44. NRC (B A Wetzel) letter to NSP (R O Anderson), Issuance of Amendment Re:

Removal of Chlorine Detector Requirements from Technical Specifications (TAC No. M88602), dated August 25, 1994.

45. NSPM Letter L-MT-08-052 (T J O'Connor) to NRC, "License Amendment Request:

Extended Power Uprate (TAC MD9990)," dated November 5, 2008.

46. NRC (M C Wong) memorandum to NRC (R D Carlson), "Environmental Review Complete for Monticello Nuclear Generating Plant, Unit 1 Extended Power Uprate Application (MD9990)," dated May 2, 2013.

47. NSPM Letter L-MT-13-020 (M A Schimmel) to NRC, "Monticello Extended Power Uprate (EPU): Second Supplement for Gap Analysis Updates (TAC MD9990),"

dated February 27, 2013.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 63 of 79 FIGURES

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 64 of 79 Figure 2.2-1 Monticello Property Map Reference Section 15 USAR Drawings ND-95208 Monticello Property Map

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 65 of 79 Figure 2.3-1 Return Period of Extreme Short-Interval Rainfall, Minneapolis, MN

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 66 of 79 Figure 2.4-1 Flow Duration Curve, Mississippi River at St. Cloud, MN

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 67 of 79 Figure 2.4-2 1965 Spring Flood at Monticello Site

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 68 of 79 Figure 2.4-3 Flood Frequency Study - Mississippi River at Monticello Site

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 69 of 79 Figure 2.5-1a Flood Frequency Study - Mississippi River at Monticello Site

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 70 of 79 Figure 2.5-1b Regional Geology Map

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 71 of 79 Figure 2.5-2 Location of Original Borings

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 72 of 79 Figure 2.5-3 Geologic Cross Section A-A

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 73 of 79 Figure 2.5-4 Log of Borings Sheet 1

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 74 of 79 Figure 2.5-5 Log of Borings Sheet 2

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 75 of 79 Figure 2.6-1 Principal Earthquakes - Minnesota Region

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 76 of 79 Figure 2.6-2 Tectonic Map of Minnesota Region

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 77 of 79 Figure 2.6-3 Seismic Regionalization U.S.A.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 78 of 79 Figure 2.6-4 Seismic Probability Map of U.S.A.

MONTICELLO UPDATED SAFETY ANALYSIS REPORT USAR-02 Revision 37 SECTION 2 SITE AND ENVIRONS Page 79 of 79 Figure 2.6-5 Seismic Response Spectra