ML24128A102

Updated Safety Analysis Report (Usar), Revision 38, Section 2, Site and Environs

ML24128A102
Person / Time
Site:	Prairie Island
Issue date:	04/30/2024
From:	Northern States Power Company, Minnesota, Xcel Energy
To:	Office of Nuclear Reactor Regulation
Shared Package
ML24128A092	List: L-PI-24-010, Revisions 255 Through 264 for Technical Specification Bases ML24128A088 ML24128A098 ML24128A099 ML24128A100 ML24128A101 ML24128A102 ML24128A103 ML24128A104 ML24128A105 ML24128A106 ML24128A107 ML24128A108 ML24128A109 ML24128A110 ML24128A111 ML24128A112 ML24128A113 ML24128A114 ML24128A115 ML24128A116 ML24128A117 ML24128A118 ML24128A119 ML24128A120
References
L-PI-24-010
Download: ML24128A102 (1)

Text

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 1 of 80

SECTION 2

SITE AND ENVIRONS

TABLE OF CONTENTS Page

2.1 INTRODUCTION

.....................................................................................7

2.2 SITE DESCRIPTION...............................................................................9 2.2.1 Location....................................................................................9 2.2.2 Topography..............................................................................9 2.2.3 Access.....................................................................................10 2.2.5 Population Distribution.............................................................12 2.3 METEOROLOGY....................................................................................13 2.3.1 General....................................................................................13 2.3.2 Descriptive Meteorology...........................................................13 2.3.3 Winds and Wind Loading.........................................................14 2.3.4 Plant Design Based on Meteorology........................................16 2.4 HYDROLOGY.........................................................................................17 2.4.1 Summary..................................................................................17 2.4.2 Hydrological Program...............................................................17 2.4.3 Surface Water..........................................................................18 2.4.4 Ground Water...........................................................................24 2.4.5 Plant Design Basis Dependent on Hydrology...........................25 2.5 GEOLOGY AND SOIL INVESTIGATION................................................27 2.5.1 General....................................................................................27 2.5.2 Regional Geology.....................................................................28 2.5.3 Site Geology.............................................................................29 2.5.4 Foundation Investigation..........................................................30 2.5.5 Soil Compaction.......................................................................30 2.6 SEISMOLOGY........................................................................................31 2.6.1 General....................................................................................31 2.6.2 Seismic History........................................................................32 2.6.3 Recent Seismic History............................................................32 PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 2 of 80

TABLE OF CONTENTS [Continued]

2.7 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM..........33

2.8 ECOLOGICAL AND BIOLOGICAL STUDIES.........................................35

2.9 CONSEQUENCES OF HYPOTHETICAL LOCAL CATASTROPHES....37 2.9.1 Effects of Oil Spillage...............................................................37 2.9.2 Postulated Explosion of Munitions Barge.................................37 2.9.3 Vulnerability of Cooling Water Intakes to Barge Collision........39 2.9.4 Toxic Chemical Study..............................................................40 2.9.5 Blast Release from Natural Gas Supply Line...........................40 2.9.6 Summary of Analysis of Effects of Local Disasters..................41 2.10 REFERENCES........................................................................................43

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TABLE OF CONTENTS [Continued]

LIST OF TABLES

TABLE 2.2-1 ESTIMATED 2010 RESIDENT POPULATION DISTRIBUTION WITHIN THE PRAIRIE ISLAND EMERGENCY PLANNING ZONE

TABLE 2.3-1 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS A (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-2 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS B (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-3 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS C (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-4 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS D (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-5 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS E (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-6 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS F (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-7 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS G (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-8 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY ALL CLASSES COMBINED (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-9 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS A (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-10 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS B (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 4 of 80

TABLE OF CONTENTS [Continued]

LIST OF TABLES [Continued]

TABLE 2.3-11 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS C (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-12 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS D (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-13 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS E (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-14 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS F (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-15 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS G (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-16 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY ALL CLASSES COMBINED (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA

TABLE 2.3-17 ANNUAL AVERAGE DISPERSION PER UNIT AREA (X/Q)

TABLE 2.3-18 RELATIVE DEPOSITION PER UNIT AREA (D/Q)

TABLE 2.3-19 SITE BOUNDARY X/Q AND D/Q

TABLE 2.4-1 MINIMUM CONSECUTIVE-DAY LOW-FLOW, IN CFS, FOR THE FIVE LOWEST YEARS OF RECORD

TABLE 2.4-2 DISCHARGE OF MISSISSIPPI RIVER AND CANNON RIVER

TABLE 2.4-3 WELLS IN PLANT VICINITY

TABLE 2.5-1 GEOLOGIC FORMATIONS IN THE GENERAL AREA OF THE SITE

TABLE 2.6-1 MINNESOTA EARTHQUAKES

TABLE 2.6-2 MODIFIED MERCALLI INTENSITY SCALE OF 1931 (Abridged)

TABLE 2.9-1 CONTROL ROOM HABITABILITY TOXIC CHEMICALS PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 5 of 80

TABLE OF CONTENTS [Continued]

LIST OF FIGURES

FIGURE 2.2-1 PROPERTY PLOT PLAN

FIGURE 2.2-2 GENERAL SITE TOPOGRAPHY

FIGURE 2.2-3 HIGHWAY TRANSPORTATION ROUTES

FIGURE 2.2-4 POPULATION DISTRIBUTION

FIGURE 2.3-1A CLIMATE OF PRAIRIE ISLAND SITE REGION - AIR TEMPERATURE

FIGURE 2.3-1B CLIMATE OF PRAIRIE ISLAND SITE REGION - RAINFALL

FIGURE 2.3-1C CLIMATE OF PRAIRIE ISLAND SITE REGION - EXTREME WINDS

FIGURE 2.4-1 LOCATION OF MAJOR STREAMS AND GAUGING STATIONS

FIGURE 2.4-2 FLOW DURATION CURVES FOR MISSISSIPPI RIVER

FIGURE 2.4-3 LOCK & DAM NO. 3 PLAN AND SECTIONS

FIGURE 2.4-4 AVERAGE TEMPERATURE OF MISSISSIPPI RIVER AT ST. PAUL, MINNESOTA

FIGURE 2.4-5 STREAM PROFILE FOR MISSISSIPPI RIVER FROM LOCK &

DAM 2 TO LOCK & DAM 3

FIGURE 2.4-6 LOCATION PLAN OF WELLS IN PLANT VICINITY

FIGURE 2.4-7 FLOOD PROTECTION KEY PLAN AND DETAILS

FIGURE 2.5-1 REGIONAL GEOLOGIC MAP OF BEDROCK FORMATIONS

FIGURE 2.5-2 REGIONAL GEOLOGIC STRUCTURE

FIGURE 2.5-3 REGIONAL GEOLOGIC CROSS SECTION

FIGURE 2.5-4 LOG OF BORINGS

FIGURE 2.6-1 EARTHQUAKE EVENTS IN MINNESOTA PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 6 of 80

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SECTION 2 SITE AND ENVIRONS

2.1 INTRODUCTION

The site for the Prairie Island Nuclear Generating Plant was thoroughly investigated for locating nuclear power reactors and found to be suitable by the USAEC. This is evidenced by issuance of Construction Permits CPPR-45 and CPPR-46 (June 25, 1968) and Facility Operating Licenses DPR-42 (August 9, 1973) for Unit 1 and DPR-60 (October 29, 1974) for Unit 2. Information pertinent to Prairie Island is contained in USAEC Dockets 50-282 for Unit 1 and 50-306 for Unit 2.

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2.2 SITE DESCRIPTION

2.2.1 Location

The site is located within the city limits of the City of Red Wing, Minnesota (population 15,134 according to 1990 census) on the right (West) bank of the Mississippi River in Sec. 4 and 5, T113N, R15W, in Goodhue County, Minnesota, at 92 37.9 west longitude and 44 37.3 north latitude.

Approximately 578 acres of land are owned in fee by Northern States Power Company at the plant location. Figure 2.2-1 shows the plant site boundaries. This figure also shows an outline of the minimum fenced area that defines the exclusion zone, which satisfies the 10CFR100 definition. 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.

East of the plant the exclusion zone boundary extends to the main channel of the Mississippi River. Islands within this boundary as well as a small strip of land northeast of the plant are owned by the Corps of Engineers. An agreement (Ref. 27 & 28) has been made with the Corps of Engineers such that no residences will be built on that strip of land or islands within the exclusion zone for the life of the plant.

The distance to the closest occupied offsite residence is 3000 ft. The governing population center, Eagan (population 47,409 according to 1990 census) lies 31 miles northwest of the plant.

2.2.2 Topography

Topography near the Prairie Island site is fairly level to slightly rolling ground ranging in elevation from 675 ft. to 706 ft. Unless otherwise stated, all elevations are in feet above mean sea level (MSL), 1929 adjustment. The surface slopes gradually toward the Mississippi River on the northeast and to the Vermillion River on the southwest. Normal pool elevation is at 674.5 ft. and the maximum reported flood (1965) was at 687.7 ft.

Steep bluffs parallel this stretch of the Mississippi River and rise to above a 1,000 ft.

elevation approximately 1-1/2 miles northeast and southwest of the site. Northeast and southwest of these bluffs, the ground elevation ranges from 1,000 ft. to 1,200 ft. and is marked by many deeply eroded coulees. Topography in the vicinity of the plant is shown in Figures 2.2-1 and 2.2-2.

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2.2.3 Access

Highway access is available to US Highway 61 via Goodhue County Rd. 18. Figure 2.2-3 shows the location of the highways in the vicinity of the Prairie Island Site.

Railroad access is available from the CP Line Railroad (formerly the Soo Line) which is about 2300 ft. southwest of the reactor buildings. The site is served by a spur from this main line. Figure 2.2-1 shows the location of this track.

Arrangements have been made with the States of Minnesota and Wisconsin Emergency Management Divisions, State Police and local law enforcement agencies to control highway, railway and waterway traffic near the site in the event of an emergency (Ref. 29).

2.2.4 Land Use

2.2.4.1 Regional Land Use Goodhue County, in which the site is located, and the adjacent counties of Dakota and Pierce (in Wisconsin) are predominantly rural. Dairy products and livestock account for most of the three-county farm products with field crops and vegetables accounting for most of the remainder. Principal crops are corn, oats, hay, soybeans, and barley.

2.2.4.2 Local Land Use The region within a radius of five miles of the site is devoted almost exclusively to agricultural pursuits. Principal crops include soybeans, corn, oats, hay and some cannery crops at about four miles from the plant site. The nearest dairy farm is located more than two miles southwest of the plant site. Some beef cattle are raised approximately two miles southwest of the site. Cattle are on pasture from early June to late September or early October. During the winter, cows are fed on locally-produced hay and silage. Beyond the site boundary and within a one-mile radius of the plant, there are approximately 20 to 30 permanent residences or summer cottages. The closest occupied offsite residence is approximately 3000 feet NNW from the plant.

2.2.4.3 Nearby Commercial Facilities At about one mile NW from the plant, the Mdewakanton Sioux Indian Community owns and operates the Treasure Island Casino, a combination resort hotel/bingo/casino gambling facility. The plants Emergency plan and the State of Minnesota Local Government Emergency Response Plans for Nuclear Power Plants include notification plans for the Treasure Island Casino in the event of a nuclear plant radiological emergency.

Another business facility, consisting of a gasoline station, convenience store and lounge, is located about two miles WNW from the plant. The emergency plans Public Alert and Notification System provides for the facilitys notification in the case of a nuclear plant radiological emergency.

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2.2.4.4 Nearby Industrial, Transportation, and Military Facilities

The following industrial facilities (workforce population greater than 30) are located within 5 miles of the plant site (Reference 25):

Advertising Unlimited, 3-4 miles South DB Industries, 3-4 miles SSE IRC Industries, 3-4 miles SSE Jostens, 3-4 miles SSE Dayco PTI, 3-4 miles SSE Protein Technologies, 4-5 miles ESE Ram Center Inc., 3-4 miles South Red Wing Shoe Company, 3-4 miles SSE Republican Eagle (Manufacturing), 4-5 miles SSE Riedell Shoe Company, 3-4 miles SSE Riviera Cabinets, 3-4 miles SSE Central Research Laboratory, 3-4 miles South

No activities at the above facilities present a hazard to the safe operation of the plant.

A buried natural gas supply line from Xcel Gas Energy is located in the west plant area, with a branch supplying the New Site Administration Building.

No military installations are within 5 miles of the plant site. Transportation activities which could potentially have an effect on the plant are described below.

The Red Wing airport is located about seven miles east southeast of the plant site in Bay City, Wisconsin, at 44 35 15 north, 92 29 40 west. It is at elevation 780 ft. msl and has one asphalt paved runway which is 5010 ft. long by 100 ft. wide and an adjacent taxiway. The runway designation is 09/27 with a 3 glide slope. There are 48 aircraft based at the airport. The 48 aircraft includes 42 single engine aircraft under 4,000 pounds, 2 multi-engine aircraft of approximately 4,500 pounds, and 2 jets, one of which is approximately 8,000 pounds and one approximately 12,000 pounds.

Railroad traffic occurs on the following railroads, which pass within 5 miles of the site:

CP Line Railroad (Soo Line) runs across the southwest portion of the Prairie Island Nuclear Generating Plant site.

Burlington Northern Railroad runs within 2 miles east of the plant site in Wisconsin.

Truck traffic occurs on Minnesota State Highway 61, which runs within 2.5 miles of the plant site to the south. In addition, a number of county roads and trunk highways are located within 5 miles of the site, as shown on Figure 2.2-3.

Barge traffic occurs on the Mississippi River, which flows in its main channel no closer than 0.5 miles from the plant site.

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2.2.5 Population Distribution

The nearest population centers from the site are Eagan (1990 population of 47,409),

26 miles northwest of the site; Minneapolis - St. Paul metropolitan area (1990 population of 2,407,090), 30 miles northwest of the site; and Rochester (1990 population of 70,745), 41 miles south of the site. No other population centers with more than 25,000 people lie within 50 miles of the site.

Table 2.2-1 shows the estimated 2010 resident population distribution within the emergency planning zone (EPZ) of the plants.

The low population zone (LPZ) radius for the Prairie Island Facility, within which there is a reasonable probability that appropriate protective measures could be taken on behalf of the residents in the event of a serious accident, has been selected as one and one-half miles. State and local governments emergency plans and the plants emergency plans include emergency notification plans for disseminating protective measures to the residents and transient population in the ten mile radius emergency planning zone which includes the low population zone area. Based on the 10 CFR Part 100 definition of a low population zone radius and the radiological effects presented in Section 14, the selection of a one and one-half mile radius is adequate.

No limitations on normal plant operation are envisioned as a consequence of population increase, because the objective of plant effluent control is to assure radiation levels at better than acceptable values and as low as practicable at all points beyond the nearest site boundary.

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2.3 METEOROLOGY

2.3.1 General

Meteorology in the region of the site was evaluated to provide a basis for determination of annual average waste gas release limits, estimates of exposure from potential accidents and design criteria for storm protection. This evaluation was based on twenty-five months of site data from May 1968 to May 1970. The preoperational meteorological data program is discussed in Section 2.8 of the FSAR. One year of supplemental data for the period June 1, 1971 through May 31, 1972 using NRC recommended delta-T stability classification is presented in Appendix H.

The data presented in Appendix H is utilized for off-site accident dose calculations.

Meteorological data is collected continuously and compiled annually. The information collected from March 22, 1974 to March 21, 1975 was used as the basis for Prairie Islands response to the requirements of 10CFR50, Appendix I. The information collected from April 1, 1977 to March 31, 1978 was used as the basis for the Offsite Dose Calculation Manual and is used for evaluating plant gaseous release rates.

Tables 2.3-1 through 2.3-19 present the meteorological data collected during calendar year 1991.

FSAR Section 2.8 and associated Figures contain the wind roses and wind persistence data for the May 1968 through May 1970 time period. FSAR/USAR Appendix H contain the wind roses and wind persistence data for the June 1971 through May 1972 time period.

For the alternate source term dose analyses, new atmospheric dispersion factors have been calculated for determining dose to the control room operators. These new atmospheric dispersion factors were determined based on meteorological data for a five year time period of 1993 through 1997.

See 5AWI 8.8.0, Environmental Monitoring Program, for additional information on Prairie Islands current meteorological monitoring program.

2.3.2 Descriptive Meteorology The climate of the site region is basically continental and influenced by the general storms which move eastward along the northern tier of the United States. The geographical location results in frequent changes in weather systems as polar and tropical air masses alternate. Climatic characteristics are illustrated in Figures 2.3-1A, B

& C which shows average and extreme temperatures, precipitation, and extreme winds at Minneapolis, Minnesota. Rainfall averages about 25 inches per year, with 65 percent falling in the months of May through September. Maximum rainfall during 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was 10.0 inches in July 1987 (Reference 20). Snowfall averages about 44 inches per year, with a maximum of 19.9 inches in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in January 1982.

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2.3.3 Winds and Wind Loading

The Prairie Island Nuclear Generating Plant was provided with a new 60 meter tower and meteorological instruments meeting Regulatory Guide 1.23, Proposed Revision 1 (Sept. 1980) in October, 1982 (Ref. 34). Wind speed, direction, and temperature difference instrumentation is located at approximately the 10 meter level and the 60 meter level. In addition, temperature and rainfall instruments are installed.

Recent joint frequency distributions for the 10 and 60 meter tower level for the period January 1, 1991 through December 31, 1991 are presented in Tables 2.3-1 through 2.3-16. The distributions are for Stability A through G as defined in Regulatory Guide 1.23. Annual average dispersion factor (/Q) and deposition per unit area (D/Q) were computed for this period and are presented in Tables 2.3-18 and 2.3-19. The Meteorological Information and Dose Assessment System was used for these calculations (Ref. 19).

Meteorological data is used to compute dispersion (/Q) and deposition (D/Q) factors for use in the dose assessment of airborne releases in accordance with the requirements of the Offsite Dose Calculation Manual. 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 10 meter level elevation and the 60 meter level.

2.3.3.1 Atmospheric Stability

Atmospheric stability is important in describing the diffusion capacity of the atmosphere.

Atmospheric stability, as used in this report, refers to the degree of wind turbulence rather than the vertical thermal structure of the atmosphere. Stable conditions are associated with low turbulence and poor atmospheric diffusion capacity. Unstable conditions are associated with high turbulence and favorable diffusion characteristics.

A typical onsite seasonal and annual distribution of atmospheric stability is shown in Table 2.3-17. Winter is the season of greatest stability, and summer has the maximum occurrence of unstable conditions.

2.3.3.2 Tornadoes

Minnesota lies to the north of the principal tornado belt in the United States. During the seven year period 1963-1969, 15 tornadoes and 21 funnel clouds were reported in the 11 square centered about the site and encompassing nearby Wisconsin and Minnesota. Over 90% of these occurrences were reported in the months of May, June, and July.

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According to statistical methods proposed by Thom (Ref. 1) the probability of a tornado striking a point within a given area may be estimated as follows:

in which P is the mean probability per year, Z is the mean tornado path area, t is the mean number of tornadoes per year in area A. Based on available data from 1963 -1969, including the sightings of funnel clouds, the value of t for the 1 square surrounding the site is 5.1. Using as the value for A, the area of the 1 square encompassing the site yields:

P = 4.5 x 10-3 year-1

At a 95% confidence interval Thoms formula becomes

in which N is the total number of tornadoes in the area of concern during the seven years of record, 1963-1969.

The 95% confidence limits are 5.8 x 10-3/yr. and 3.8 x 10-3/yr. The mean recurrence interval, R = 1/P, is 220 years; and, at these confidence limits the recurrence intervals, R = 1/P, range between 170 and 260 years.

Damage caused by tornadoes results from three principal effects:

a. The dynamic forces resulting from the high velocity vortex winds

b. The bursting forces caused by differential static pressure resulting from the sharp pressure reduction in the immediate vicinity of a tornado funnel.

c. The impact of missiles generated by (a) and (b).

The most widely accepted values of wind speed in a tornado appear to be about 300 mph (Refs. 2, 3, 4) or less for a very severe tornado at the peak of its intensity.

Some sources mention values as high as 500-600 mph (Refs. 2, 5) but these estimates appear to be based on indirect observations of phenomena such as straws driven into trees, etc., and are not regarded as authoritative.

The highest directly observed wind velocities were derived from motion pictures of debris in the Dallas tornado of April 2, 1957 (Ref. 3). These velocities range up to 170 mph tangential and 150 mph upward resulting in a maximum wind vector of 220 mph. If higher velocities were present, they must have been very localized and not typical of the average wind on large bodies.

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The design wind speed of 300 mph with a forward progression of 60 mph is about 36 percent greater than that of the Dallas tornado and is thought to be quite conservative in view of the Prairie Island plant location.

The greatest recorded pressure drop associated with a tornado was equivalent to a bursting pressure of approximately 3 psi, (Ref. 2) while the greatest measured pressure drops have been on the order of 1.5 psi.(Refs. 2, 6, 7, 8, 9) For the Dallas tornado mentioned above a maximum pressure drop of about 0.9 psi was determined from calculations (Ref. 3).

The structural design criteria used to assure adequate design to accommodate the most severe storm conditions are discussed in Section 12.2.

2.3.4 Plant Design Based on Meteorology

Based on meteorological data in the region of the site, at the site, and plant operational characteristics, the offsite doses arising from routine plant operation satisfy the guidelines of Appendix I to 10CFR50 (Ref. 10).

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2.4 HYDROLOGY

All elevations stated are referenced to 1929 datum mean sea level.

2.4.1 Summary The principal surface waters in the vicinity of the site are the Mississippi River, Sturgeon Lake, the Vermillion River, and the Cannon River. The levels of the Mississippi River and Sturgeon Lake are controlled by Lock and Dam Number 3 which is located approximately one and one-half miles downstream from the plant. The Vermillion River enters the main stream of the Mississippi below the dam. The maximum flood of record occurred in 1965 when a peak stage of 687.7 ft. was recorded. Flood stages during the anticipated plant life are not expected to exceed levels attained during 1965.

The ground water table is normally within 5 to 20 feet (approximately 674.5 ft.) of the ground surface of the site and appears to slope southwest from the Mississippi River toward the Vermillion River. The nearest ground water consumption of important magnitude is in the town of Red Wing, six miles downstream.

2.4.2 Hydrological Program

A hydrological investigation of the site was performed by Dames & Moore. The scope of the hydrological program consisted of:

a. A review of pertinent data regarding the flow, usage, temperature, chemical and biological characteristics, and other properties of Mississippi River waters and other adjacent surface waters

b. A study of the hydrological interrelationship between the Mississippi River, Sturgeon Lake, the ground waters underlying the site, and other adjacent surface waters.

c. A study of the infiltration characteristics of the near-surface soils at the site, and the determination of the composition and permeability characteristics of the bottom sediments in Sturgeon Lake and the slough areas located immediately east of the site.

d. The performance of pumping tests to obtain information regarding permeability, transmissibility, and storage characteristics of the deeper soil strata.

Certain data pertaining to the Mississippi River are presented in this section. Other data and the results of the various hydrological field studies are reported in Appendix E.

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2.4.3 Surface Water

2.4.3.1 Surface Drainage

Surface drainage on Prairie Island at the site is essentially nonexistent, owing to the extremely sandy nature of the soils and the topography of the island. There are no well-established drainage lines, and because of the hummocky nature of the terrain, there are many small internal drainage basins.

2.4.3.2 Stream Flow

The Mississippi River and its major local tributaries, the Vermillion River and the Cannon River, are the principal streams of the area. The location of the major streams and gauging stations are shown on Figure 2.4-1. The Mississippi River is dammed at a point about one and one-half miles downstream from the plant by Lock and Dam Number 3. Its two major local tributaries enter the main stream below the dam. The normal pool upstream from the dam is at 674.5 ft.

There are no withdrawals of river water for city water supply for at least 300 miles downstream from the site. Minor withdrawals of river water for irrigation purposes do occur, the nearest being 53 miles downstream.

Stream flow records are available for the Mississippi River at Prescott and at Winona, and for the Cannon River at Welch. Figure 2.4-2 shows flow duration curves for the two stations on the Mississippi River.

Table 2.4-1 summarizes the consecutive-day low-flow characteristics of the Mississippi River at Prescott. The discharge characteristics of the Mississippi and Cannon Rivers are summarized in Table 2.4-2.

2.4.3.3 Availability of Circulating Water and Cooling Water

2.4.3.3.1 General Characteristics of Water Supply

The circulating water intake is located in the upper pool of Lock and Dam Number 3.

The lock and dam is one of a series of navigation dams on the Mississippi River for the purpose of maintaining a minimum-depth navigation channel. The flow in the river is for the most part unregulated, i.e., natural river flow is passed through the dam so as to maintain an unvarying upper pool level. The normal upper pool is at 674.5 ft. This level may be lowered to 672.5 ft. at the dam to control pool elevation at Prescott to 674.5 ft.

for a river flow of approximately 17,000 cfs. The bottom of the main channel at the circulating water intake is at 655.6 ft, creating a pool with a minimum normal depth of 18.9 ft. The lowest one-day unregulated flow recorded in 37 years of record is 1,380 cfs on July 13, 1940, as shown in Table 2.4-2.

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Because the flows on the days immediately before and after are significantly different than this figure, it appears that this flow was not a natural occurrence. The flows for the period in question are tabulated below:

Date Flow (cfs) 7-10-40 6090 7-11-40 11,400 7-12-40 3760 7-13-40 1380 7-14-40 5300 7-5-40 4620 7-16-40 3350 7-17-40 2220

The St. Paul District of the Corps of Engineers, in charge of reservoir regulation, has stated that several days prior to July 13, 1940, a heavy rainfall occurred in the Upper Mississippi Valley. Anticipating an increased flow, the operator at Lock and Dam No. 2, on July 11, opened the gates excessively, allowing a flow of approximately 10,000 cfs.

This resulted in an extreme draw-down of the pool behind Lock and Dam No. 2 and required that the flow for the following days be restricted in order to refill the reservoir.

On July 13, the flow through Lock and Dam No. 2 was 900 cfs. According to the Corps of Engineers, the flow contributed by the St. Croix River was approximately 1800 cfs resulting in a combined flow at the Prescott gage of approximately 2700 cfs. The Corps of Engineers believes that the recording of 1380 cfs for July 13 is in error, and should be closer to 2700 cfs. For the period of record considered for design of cooling facilities at Prairie Island, the next lowest flow is 2100 cfs in 1936.

2.4.3.3.2 Accidents to Water Supply

The reliability of near-normal pool levels at the circulating water intake is dependent on the structural integrity of various elements of Lock and Dam Number 3. The vulnerable elements of the dam affecting upper pool levels are (1) the dikes, (2) the lock miter gates and (3) the spillway gates. These elements and their locations in the dam are shown in Figure 2.4-3.

Accidents or natural disasters could remove all or part of one of these elements and thereby cause a lowering of the upper pool well below the normal level. The resulting stable new pool level would be controlled by the elevation of the lower pool which in turn is established by Lock and Dam Number 4 located 44.1 river miles downstream. The normal lower pool level of Lock and Dam Number 3 is 666.5 ft. Dam Number 4 is operated to maintain water level at Wabasha at 666.5 ft. The loss of a miter gate or spillway gate will tend to equalize the pools on either side of the dam at the elevation of the lower pool. Natural flow will establish the upper pool at an elevation somewhat higher than the lower pool, depending on the flow rate.

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The most probable accident to the dam involves the dike which could be breached by overtopping or embankment failure. If this occurred, the upper pool level could be lowered to the base of the dike. The lowest height of the upper pool that could be produced by an accident of this type is at 671.5 ft.

The low upper pool elevation consistent with an accident resulting in the loss of a set of miter gates, or in the loss of one spillway gate, is 666.5 ft. A loss of all gates (miter gates and four spillway gates) would equalize the upper and lower pools at the lower pool elevation. The lowest water level experienced prior to operation of Lock and Dam Number 4 was at 662 ft. in 1934.

2.4.3.3.3 High Main Channel Velocities

An accident to miter gates or spillway gates at normal upper and lower pools would temporarily cause unnaturally high flow rates in the upper pool. This in turn would cause higher than normal main channel velocities. In the case of loss of a set of miter gates, the main channel average velocity would be 1.5 fps. The loss of one spillway gate results in a main channel average velocity of 1.6 fps. The loss of all spillway gates would result in a main channel average velocity of 6.2 fps.

2.4.3.3.4 Overall Reliability of Cooling Water Supply

An adequate water supply from the Mississippi River is assured to meet cooling water requirements. The minimum natural river flow is 2100 cfs (942,500 gpm). An accident to the dam concurrent with normal water flows would produce a pool elevation at the intake of 666.5 ft. This latter condition is the one consistent with safeguards philosophy and provides a pool 10.9 ft. deep at the circulating water intake.

Flow velocities past the intake after an accident to the dam will not divert flow from the intake. The design of the cooling water supply is such that adequate water will be delivered into the plant under any condition. See Section 10.4 for details of the intake structure and the emergency cooling water intake.

2.4.3.4 River Temperature

The design maximum temperature for the Cooling Water System is 85F. This value was chosen based on historical data gathered at several sites on the Mississippi River.

The value is that temperature that is not expected to be exceeded more than 1% of the time.

A temperature curve showing the average monthly temperature of the Mississippi River at St. Paul is presented in Figure 2.4-4. Indications are that, on the average, these temperatures are from two to three degrees higher than those at the site.

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2.4.3.5 Floods

According to the U.S. Army, Corps of Engineers, the 1965 flood, which is the highest on record, has a recurrence interval of 150 years. The peak stage at Lock and Dam Number 3 during this flood was 687.7 ft. It is estimated by the Corps of Engineers that a flood having a 1000-year recurrence interval would have a peak stage of about 691.8 ft. at Lock and Dam Number 3, and a discharge of about 335,000 cfs.

A stream profile of the section of the river near the site is presented in Figure 2.4-5 showing profiles of the highest and lowest flow of record. An approximate longitudinal land profile of the Prairie Island site is also shown in Figure 2.4-5.

A study to determine the magnitude of the probable maximum flood has been done for this area of the Mississippi River by Harza Engineering Company. The probable maximum discharge was determined to be 910,300 cfs and to have a corresponding peak stage of 703.6 ft. The flood would result from meteorological conditions which could occur in the Spring and could reach maximum river level in about 12 days. It was estimated that the flood stage would remain above 695 ft. for approximately 13 days.

The detailed results of the study are presented in Appendix F. Wind generated waves would be of maximum height when the wind is from east to west in the direction of the circulating water intake canal. With a persistent wind speed of 45 mph the height of the significant wave1 would be less than 1.8 feet (crest to trough). The maximum one percent wave height, consistent with the highest significant wave, is estimated to be less than 3.10 feet. If the conservative assumption is made that run-up equals the approaching wave height, then the maximum water level would be 706.7 ft.

The main powerhouse structure consisting of the reactor buildings, the auxiliary and fuel handling building, the turbine building, the D5/D6 diesel generator building, and the pump section of the screenhouse structure are protected against the probable maximum flood of 703.6 ft. This is equivalent to 704.1 ft. (1912 adj) from the Harza Engineering Study. The base slabs of these structures have been designed to resist the full hydrostatic head of the probable maximum flood. The top of the substructure and/or superstructure flood protection walls are at 705.0 ft, and are designed to resist the probable maximum flood. These structures are capable of withstanding the hydrostatic forces associated with the probable maximum flood and associated maximum wave run-up to 706.7 ft. Some water leakage would occur whenever wave action exceeds 705 ft. on certain portions of the turbine building and auxiliary building walls. This leakage would occur through the joint between the top of the concrete wall and the bottom of the metal siding. This event would not compromise, or cause a loss of, any safety related function for two reasons. First, the leakage would represent a relatively small quantity of water which could be easily handled by plant sump pumps.

1 Significant and maximum one percent wave height and run up are defined in Shore Protection and Planning an Design,: Technical Report No.4, 3rd Edition, 1966 U.S. Army Corps of Engineers Coastal Engineering Research Center.

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Second, the leakage would occur at a great enough distance from safety related equipment that there would be no direct contact of the water with such equipment.

All construction joints are keyed and provided with water stops. Penetrations through the foundation base slabs and flood protection walls below 703.6 ft. were held at a minimum. Necessary penetrations are closed prior to flooding with bulkheads stored on site. Hydrostatic pressures compress sealant materials along outside edges to assure a water tight fit on bulkhead closures. Figure 2.4-7 shows the location and details of all bulkhead closures and flood protection walls.

The only safeguards related equipment located outside the structures mentioned above are the diesel fuel tanks and fuel storage vaults, pipes and control cables all of which are buried and are designed to resist hydrostatic forces as well as other effects associated with the probable maximum flood.

The cooling tower pump house and the generator step-up transformer are protected from floods to 695.0. The substation and cooling tower transformers will function when flooded up to 698.0 ft. Normal plant operation is limited to flooding below 695.0 ft.

The Prairie Island plant is designed such that all areas critical to nuclear safety are protected against the effects of the probable maximum flood and associated maximum wave run-up. Plant operating procedures and emergency plans state the flood stage elevations at which plant protective measures must be taken. These procedures will require placing the unit in Mode 3, Hot Standby, when flood stage elevations exceed 692 feet at the plant site.

Long range advisory projections and short-term forecasts of river stage and crest are supplied by the National Weather Service Office, Minnesota River District for gage stations on the Mississippi River and its major tributaries. Gage stations covered include Hastings and Red Wing, up river and down river from the plant site. Advisory and forecast reports are received directly in the NSP system dispatch center. The basis to readily interpret these projections for specific locations between gage stations is developed in cooperation with the Corps of Engineers and Department of Commerce National Oceanic and Atmospheric Administration.

NSP has had extensive experience in using these advisories and forecasts to develop and use flood procedures for successful continued operation of many river-site plants subject to seasonal floods of varying degree.

Advance planning and preliminary arrangements for operation during floods would be based on the advisory reports of flood potential. Implementation of flood procedures would be based on the three-day forecasts of flood stage and actual flood stage at the plant site.

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In the event that three-day flood forecasts project crests greater than the minimum access road elevations, plant emergency fuel oil storage tanks will be maintained on a keep-full status until the access road becomes impassable or the flood crest has subsided below this level. Backup provisions for transportation of plant personnel and other plant supplies will be instituted.

In the event that three-day forecasts project a crest in excess of those stated in the plant operating procedures, bulkheads, which are stored onsite, will be installed to close all openings in the flood protection walls and sandbag barriers will be constructed around the substation control house. Normal operation will continue to a flood stage elevation stated in the plant operating procedures.

When flood stage exceeds elevations (692 ft.) stated in the plant operating procedures, both units would be taken to Mode 3, Hot Standby, and actions taken to assure availability of offsite power. Control circuitry for the respective source breakers in the plant substation would be defeated and fault protection would be provided at the source end of all offsite transmission lines.

The emergency and normal cooling water pumps are operable to a flood stage of elevation 695.0 ft. with no additional protective measures required. The cooling water pumps and their associated equipment are located in the Class I, Type I portion of the screen house which is designed for the probable maximum flood. When three day forecasts project crests in excess of those stated in the plant operating procedures, bulkhead closures in the flood openings of this structure will be installed and the normal cooling water pumps could continue service as long as station auxiliary electrical power is available. In the event emergency diesel power use becomes necessary, the emergency cooling water pumps are capable of providing all essential and normal cooling water service up to the maximum probable flood stage considerations.

As discussed in Section 10.3.13, any combination of the six Unit 1 Design Class I fuel oil storage tanks will allow operation of one safety related Unit 1 emergency diesel generator, D1 or D2, and one diesel driven cooling water pump, 12 or 22, for 14 days.

Any combination of the four Unit 2 Design Class I fuel oil storage tanks will allow operation of one Unit 2 emergency diesel generator, D5 or D6 for 14 days. This is longer than the 13 days that the river flood level for the probable maximum flood will remain above the plant grade elevation. The emergency diesel fuel oil storage tanks will be filled to capacity for the extended period the access road may be impassable during flooding conditions, as discussed above as a keep full requirement.

2.4.3.5.1 Floods from Dam Failure

Lock and Dam Number 2 is located 17 miles upstream of the plant site. The difference in normal pool elevations across the dam is 12.2 feet. Failure of the dam could result in a sudden release of water, temporarily producing the effect of a flood in the river channel downstream of the dam. The storage effect of the lower channel basin and the resulting loss of head in the upper reservoir will greatly attenuate flooding effects at the Prairie Island site.

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There is no flood hazard resulting from a dam break at Lock and Dam Number 2. This conclusion was substantiated by determining stable water level elevations at Lock and Dam Number 3 resulting from sustained flow with the loss of 10 tainter gates at Lock and Dam Number 2. Sustained flow will maintain the upper pool elevation at Lock and Dam Number 3, and will provide the volume of water needed in the lower pool to produce the maximum pool level consistent with steady flow supplied through 10 spillway bays. The flow resulting from these postulated extreme conditions would produce a river level at 684.5 ft. in the lower pool at Lock and Dam Number 2 with a corresponding level in the upper pool at Lock and Dam Number 3 of 676.5 ft.

2.4.4 Ground Water

2.4.4.1 Regional Characteristics

Regionally, the movement of ground water is toward the Mississippi River and its main tributaries. The ground water table slopes from the higher, glaciated bedrock areas toward these surface streams, generally at low gradients. Ground water enters the river valley from along the base of the bordering bedrock bluffs in the form of springs or as subsurface flow.

Beneath the flood plains and low terraces which border the Mississippi River, ground water levels closely coincide with the elevations of the river surface, and vary in accordance with river fluctuations. The average ground water gradient in these bottom lands is downstream, and essentially parallel to the stream gradient.

Pool elevation on the Mississippi River adjacent to the site is controlled by Lock and Dam Number 3. The Vermillion River by-passes the dam and therefore is not directly controlled by it. Elevations on the Vermillion River and connected lakes are therefore lower than the Mississippi River and the ground water table slopes southwestward between the two rivers. Due to the permeable nature of the sandy alluvial soils forming Prairie Island, the ground water table responds quickly to changes in river stage.

There is only minor usage of ground water for domestic, agricultural and irrigation purposes near the site or immediately downstream. A deep well believed to penetrate bedrock aquifiers exists at Lock and Dam Number 3. The nearest ground water consumption of important magnitude is in the town of Red Wing, six miles downstream.

This community derives its water supply from four deep wells which penetrate sandstone aquifier of the Dresbach and Hinckley formations. The wells pump from depths of 400 to 730 ft., and each well is capable of providing the municipal requirements of about 1400 gpm. A high degree of hardness is characteristic of the water from these wells.

Several industries in the Red Wing area also utilize ground water in quantities exceeding the municipal consumption, and derive their supplies principally from the bedrock aquifers. Total well production from the bedrock at Red Wing probably exceeds 3000 gpm, and fairly large quantities may also be extracted from the alluvium for certain industrial uses.

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Communities further downstream from the plant site which supply their water needs from wells in bedrock are Lake City, 25 river miles downstream, and Wabasha, 37 miles downstream.

A survey of 58 wells in the vicinity of the plant site is summarized in Table 2.4-3. The location of the wells and an outline of the survey area are shown on Figure 2.4-6.

2.4.4.2 Movements of Effluents

Dispersion of effluents entering the ground water system from the plant would take place principally in the upper portion of the saturated zone of the river alluvium. Due to the numerous surface waterways in the vicinity of the site, the majority of effluents would permanently leave the ground water environment and would mix with surface waters at the borders of Prairie Island.

The coefficient of horizontal permeability for the shallow aquifer beneath the site is:

Kh = 1,000 to 4,000 gallons/day/sq ft

Vertical permeability is about 30 percent of horizontal permeability. Due to the relatively permeable nature of the soils at the site, a path exists to the deeper bedrock aquifers directly below the site. Silt deposits lining the bottom of the river channels, however, have virtually eliminated exposure of bedrock aquifers to the main stream of the river.

There is no reason to believe effluents will penetrate to the depth of bedrock aquifers. It is very unlikely that significant amounts of effluents could succeed in reaching shallow wells at Red Wing by way of continuous ground water paths.

Any possible recharging of the shallow aquifer at Red Wing by river water would be expected to entail dilution of the river water with stored ground water and other sources, time decay of activity, and removal of activities other than tritium by filtration through the soil.

The annual average dilution factor for the Mississippi River at Red Wing considering substantial use of cooling water is about 18. A minimum factor is 3.3 based on the 7-day average low flow having a once-in-ten-year probability of recurrence. Credit is not taken for the relatively minor flows contributed between the site and Red Wing by the Vermillion and Cannon Rivers.

The overall dilution factor includes that accomplished before release to the Mississippi River, which is expected to result in less than 0.1 MPC discharge to the river.

Therefore, an overall minimum dilution factor of at least 33 would occur at Red Wing.

2.4.5 Plant Design Basis 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 accounts for large variations in water flow from less than 2000 cfs to flood flows. Plant grade is about 695 ft. which is 7 ft. above record historical floods. The plant is designed to withstand the effects of the probable maximum flood.

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2.5 GEOLOGY AND SOIL INVESTIGATION

2.5.1 General

A detailed geological investigation was performed at the site by Dames & Moore. The geological program consisted of:

a. A review of pertinent literature and preliminary boring data, and discussions with local geologists, in order to describe regional characteristics, bedrock structure, and the general character and thickness of overburden soils at the site.

b. A study of the geological features of the site and environs by means of visual field reconnaissance and interpretation of maps and aerial photographs.

c. A detailed test boring and laboratory test program performed to identify predominant soil and rock types and to evaluate pertinent physical properties of the soil and rock strata present at the site.

d. Analyses to develop a suitable foundation system.

Certain pertinent data concerning regional and site geology are presented in this section. Other data and the results of field studies are reported in Appendix E.

The location and general topographic features of the site are shown on Figures 2.2-1 and 2.2-2.

The sub-surface soils at the site consist of permeable sandy alluvium. The sandy alluvium ranges in thickness from 158 to 185 feet and is variable with respect to engineering properties. The soils are generally suitable from a bearing capacity (shear failure) standpoint for support of the structures, but settlement restrictions and/or a low margin of safety against liquefaction of the upper 50 feet (above elevation 645) of alluvium required that certain critical structures be supported on densified sand.

Several hundred feet of sound sandstone underlie the alluvial soils.

The plant site is located in a region of very low seismic activity. There is no evidence of even ancient inactive faulting within six miles of the site. Inactive faults are located approximately 6 and 13 miles from the site. No activity has occurred along either of these faults in recent geologic times.

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2.5.2 Regional Geology

Precambrian granite, gneiss, schist, and volcanics comprise the oldest bedrock in the Minnesota-Wisconsin region. The basement rock is overlain by as much as 800 ft. of Paleozoic sandstone, shale and dolomite. Younger formations originally present in the region have been removed by erosion, and an irregular topography has been developed on the exposed bedrock surface. Except for local areas in southeastern Minnesota and parts of Wisconsin, bedrock is concealed under 100 to 300 feet of Pleistocene glacial drift. In contrast, the extreme southeastern tip of Minnesota, including the site vicinity, is covered by only a thin veneer of drift. It is therefore considered a part of the driftless area commonly referred to by glacial geologists. In this driftless area of Minnesota and central and southwestern Wisconsin, the unconsolidated materials consist primarily of loess, recent alluvium, and residual soil.

Drainage in the region is controlled by the Mississippi River. The Mississippi River originated as an outlet for early glacial meltwaters. Its major present day tributaries were developed by the draining of glacial lakes at the close of the Pleistocene.

A geologic column showing the thicknesses and age relationships of the various bedrock units and surficial deposits of the region is presented on the generalized stratigraphic column presented in Table 2.5-1.

The regional extent of the consolidated strata is shown in Figure 2.5-1.

2.5.2.1 Structure and Faulting

The dominant structural feature in Southeastern Minnesota and adjacent areas of Wisconsin and Iowa is the Keweenawan Basin. This basin was formed in early Precambrian time and extended from Lake Superior into Iowa. It provided a site for the deposition of thick sequences of later Precambrian and Paleozoic strata consisting of volcanics and sediments. These beds were gently warped by subsequent compressive forces into several subordinate structures. A large basin in the Paleozoic rocks extended northward from Iowa into the southeastern corner of Minnesota. This basin is separated from a smaller basin in the Twin Cities area by the Afton-Hudson anticline.

The anticline begins at Farmington and trends northeastward through Hastings, Minnesota and Hudson, Wisconsin. A syncline lies to the east of this structure in the vicinity of River Falls, Wisconsin. Near the extreme southeastern corner of Minnesota, a second anticline extends from Rochester through Red Wing and is postulated to extend a short distance into Wisconsin.

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Several major faults in the Minnesota-Wisconsin region have been inferred from geophysical surveys. The principal movements along these faults, which amounted to thousands of feet, appear to have been restricted to Precambrian time. The Douglas fault and the Lake Owen fault penetrate Precambrian rocks along the North and South sides of the Keweenawan Basin, respectively. A southern extension of the Lake Owens fault, which is known as the Hastings fault, trends southwest near the city of Hastings, about 13 miles northwest of the site. Minor activity occurred along the Hastings fault during both Precambrian and Paleozoic times. Other minor movements occurred in the Paleozoic strata six miles southeast of the site near the city of Red Wing, and approximately 20 miles northeast of the site in the River Falls syncline near Waverly, Wisconsin.

There is no evidence of recent activity along any of the known fault zones in the Minnesota-Wisconsin region.

The locations of these structural features are shown in Figure 2.5-1. Regional geology is further shown in Figure 2.5-2, and in Figure 2.5-3.

2.5.3 Site Geology

Prairie Island is a low island terrace associated with the Mississippi River flood plain. It is separated from other parts of the lowland by the Vermillion River on the west, and by the Mississippi River on the east. Ground surface elevations range from approximately 675 to 706 feet. Most of Prairie Island is under cultivation. Other lowland areas near the site are forested or covered by swamp vegetation.

The Mississippi River flood plain in this area is confined within a valley about three miles wide. Rocky bluffs and heavily forested slopes rise abruptly from both sides of the valley to a height of about 300 feet. The uplands immediately surrounding the valley reach elevations ranging from approximately 1000 to 1200 feet. They are deeply trenched by numerous streams emptying into the Mississippi River.

The overburden materials at the site are permeable sandy alluvial soils which were deposited as glacial outwash and as recent river sedimentation. Preliminary borings, such as that shown in Figure 2.5-4 and other borings (see Appendix E) indicated that the overburden soils at the site vary from 158 to 185 feet thick.

The uppermost bedrock unit at the site is sandstone and is believed to be part of the Franconia formation (See Table 2.5-1). Its thickness at this location is unknown, but would be much less than 180 feet, the total measured thickness of the Franconia formation in complete sections. Underneath the Franconia formation are several hundred feet of lower Cambrian and Precambrian sandstone with minor shale horizons.

The site is located on the west limb of the Red Wing anticline, as evidenced by a gentle westward dip of the bedrock.

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2.5.4 Foundation Investigation

The location of the principal structures, including the turbine and reactor buildings, intake structure, and discharge facilities are shown in Figure 2.2-1. The location of soil borings is shown in Appendix E and the log of a typical boring is shown in Figure 2.5-4.

Dynamic soil tests were conducted because the probability of liquefaction is high under the cyclic loadings produced by the 1952 Taft earthquake (see Appendix E), 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 (Reference

11) demonstrate that sands denser than the critical void ratio can be made to liquefy under cyclic loading.

2.5.5 Soil Compaction

According to the Dames & Moore report in Appendix E, soils above elevation 645 have a low margin of safety against liquefaction under the postulated maximum credible earthquake. To provide for a suitable margin of safety against liquefaction it was recommended to either:

a. Support critical plant structures on piling founded in the dense sands below elevation 645.

b. Densify the in-place granular soils above elevation 645 by the vibro-flotation method.

c. Densify the soils above elevation 645 by excavation and recompaction.

Economic studies of all three above methods were conducted. Method (c) was selected; design and construction commenced. The final design called for dewatering the foundation area to elevation 642, excavation of the area to elevation 645, and recompacting the area using the excavated material as fill. The fill was placed in three-inch layers and compacted to 100% maximum density as determined by the American Association of State Highway Officials Test Designation T 180 - 57. This corresponds to at least 85% relative density -- the figure above which soils of this type will not liquefy.

The fill was replaced and compacted to the appropriate elevations upon which the foundation slabs were placed.

The results of the field testing done by Dames & Moore during the excavation and recompaction procedure revealed that the required densities were obtained throughout the area and the foundation design and construction meet all safety criteria.

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2.6 SEISMOLOGY

2.6.1 General

A seismological investigation of the site was performed by Dames and Moore. The seismological program consisted of:

a. An evaluation of the seismicity of the area.

b. A study of geologic structure as related to earthquake activity.

c. The postulation of operational and design earthquake accelerations, and the preparation of recommended response spectra.

d. Field and laboratory measurements of the dynamic response characteristics of the soil and rock strata underlying the site.

The results of the seismological program are reported in Appendix E.

The State of Minnesota has experienced only a few moderate earthquake shocks in the relatively short period since 1860 during which earthquakes have been recorded in the State. A tabulation of earthquakes having epicenters in Minnesota, together with certain out-of-state earthquakes felt in Minnesota, is presented in Table 2.6-1 and in Figure 2.6-1. Earthquake intensities are described in terms of the Modified Mercalli Intensity Scale of 1931, which is explained in Table 2.6-2.

Based on the seismic history and the regional tectonics, it is anticipated that the site will not experience any significant earthquake motion during the economic life of the nuclear facility. Historically, there is no basis for expecting ground motion of more than a few percent of gravity. However, for conservatism, the plant is designed to respond elastically to earthquake ground motion as high as 6 percent gravity, with no loss of function. Provisions have also been made for safe shutdown of the reactor if ground motions reach as high as 12 percent of gravity in the overburden soils at the site. In the event of an earthquake, plant operating procedures identify the action thresholds for plant shutdown and post event physical inspection of the facility.

Because of a low margin of safety against liquefaction during a design basis earthquake, all critical structures at elevation 645 or higher have been supported on densified sand. All foundations are within the sand above the bedrock.

The design of the structures and their foundations took into account the dynamic effects of earthquake motion. Consideration was given in the design to maximum expected ground motions, response spectra, and elastic moduli and damping values of the various soil and rock. Seismic design criteria are provided in Section 12.

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2.6.2 Seismic History

Southeastern Minnesota is considered one of the least active seismic zones of the United States. Kings distribution of epicenters contours the area as having less than one epicenter per 10,000 sq. km, the least active classification (Ref. 26). However, earthquakes are not unknown in Minnesota. At least six (1860, 1865-70, 1917, 1928, 1939, and 1950) have had local origins, and certain others, with epicenters outside the state, have been felt within the borders of Minnesota. These events are discussed in Appendix E, Section 4. There has been no seismic activity of any consequence in recent years in the vicinity of the plant.

2.6.3 Recent Seismic History

An extensive seismic monitoring system is installed at Prairie Island. Only one seismic event has been recorded at the plant. An earthquake triggered the seismic alarm about 0650 on June 10, 1987. The seismic acceleration was measured at about 0.01 g, the lower limit of detectability for the installed instrumentation. The quake was centered in southeastern Illinois and caused tremors in fifteen states and Canada. The quake was not detectable at the Monticello Nuclear Generating Plant.

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2.7 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

The Radiological Environmental Monitoring Program (REMP) for the Prairie Island site environs was initiated in May 1970 and has continued through start-up and plant operation. The purpose of the REMP is to assess the impact of plant operation on the surrounding environment and evaluate the performance of systems and equipment installed in the plant to control releases of radioactive materials.

The monitoring system design is based on the indicator-control concept. Most types of samples are collected both at indicator locations (nearby, downwind or downstream) and at control locations (distant, upwind or upstream). A plant effect would be indicated if the radiation level at an indicator location was significantly larger than that at the control location and could not be accounted for by typical fluctuations in radiation levels arising from other sources.

The environment near the plant is sampled and analyzed for selected radioactive isotopes in accordance with the requirements of the Offsite Dose Calculation Manual (ODCM). These samples include air, direct radiation, terrestrial (well water, drinking water, milk and cultivated crops) and river (water, fish and sediment).

A census is conducted annually to determine that location of the nearest milk animal and garden (larger than 500 square feet) producing broad leaf vegetation.

The results of the radioanalysis of these samples and the data collected from the environmental monitors are reported to the NRC in the Annual Radiological Environmental Monitoring Report in accordance with the requirements of the Technical Specifications.

In February, 1982, changes to the Technical Specifications deleting the Appendix B Environmental Technical Specifications (and inserting certain environmental reporting requirements previously included in Appendix B into Appendix A) were approved by the NRC (Reference 15). Other changes to the Technical Specifications to implement the requirements of Appendix I of 10 CFR Part 50, based on the guidance provided by NUREG-0472 and NUREG-0133, were approved by the NRC in October, 1982, and are effective January 1, 1983 (Reference 16). The Offsite Dose Calculation Manual and the Process Control Program were also accepted by the NRC at the same time. The NRC further concluded that the radwaste systems presently installed and the provisions in the revised Technical Specifications are adequate to reduce releases of radioactive material in liquid and gaseous effluents to as low as reasonably achievable (ALARA) levels.

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2.8 ECOLOGICAL AND BIOLOGICAL STUDIES

On January 19, 1981, 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. MN0004006 [Ref. 30] coverin g the Prairie Island Nuclear Generating Plant. This permit is reissued with any modifications 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.

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2.9 CONSEQUENCES OF HYPOTHETICAL LOCAL CATASTROPHES

2.9.1 Effects of Oil Spillage

The plant is fully protected from possible effects of oil spillage on the river by the design of the intake screenhouse and earthen dikes which prevent floating oil from entering the plant. The only water intake that bypasses these barriers is the emergency intake to the cooling water system and this intake is located in a crib at the bottom of the river branch beyond the intake canal.

In addition, the suction intakes for the circulating water pumps, the cooling water pumps, and the fire pumps are submerged in bays within the screenhouse.

Another purpose of these barriers is to prevent uncontrolled return of hot surface water to the river when the plant is operated with cooling towers, the return flow from which is by a return canal that merges with the plant intake canal.

In conclusion, the operation of the circulating water system, the engineered safety feature cooling water system, and other systems is unaffected by the occurrence of an oil spill.

2.9.2 Postulated Explosion of Munitions Barge

In the absence of reported bulk shipments of munitions or other explosives this far north on the Mississippi River, the question of a barge explosion can be relevant only in the sense that such cargo is not restricted.

The size and nature of a hypothetical cargo that might be postulated to explode is entirely speculative; therefore it is assumed conservatively that a jumbo barge (195 ft.

length, 35 ft. width, 8-1/2 ft. draft), the largest hauler of dry cargo, is completely laden with 1400 tons of TNT, and that this cargo detonates in mid-channel directly opposite the plant. The resulting 1.4 kiloton explosion would be comparable to the Texas City disaster (April 1947) which resulted from detonation of 2 to 4 kilotons of equivalent explosive.

A mid-channel location opposite the plant would be along the Minnesota-Wisconsin line, which is a minimum of 2600 feet distance from the control room, at a point nearly due east from it. An overestimate of the blast effect is given by assuming the occurrence of a surface blast at this point.

Surface detonation of 1.4 kilotons would result in a peak overpressure of 2-1/4 psi at 2600 feet distance, plus a minor dynamic pressure due to a 78 mph transient wind, as determined directly by use of The Nuclear Bomb Effects Computer (Ref. 12). The overpressure would actually be substantially less because of the attenuation and vertical blast deflection that would occur due to the fact that much of the full cargo would necessarily be located below the waterline.

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The effects of this pressure on either of the shield buildings can be scaled conservatively from the results of previous calculations of tornado loading. The tornado-induced stresses were based on a 1.56 psi frontal overpressure with resultant areas of depression up to minus 3 psi on the sides of the structure. The maximum local tensile stress in any steel reinforcement member was determined to be 50,000 psi, relative to a minimum yield strength of 60,000 psi and a minimum ultimate strength of 90,000 psi. This occurred for certain more highly loaded members at mid-elevation in the structure. The concrete was nowhere compressively stressed to more than about one-half its compressive strength.

The calculated frontal overpressure of the blast, and the overall blast loading, will momentarily be 1.44 times as great as for the tornado, and should correspondingly cause a maximum local tensile stress of 72,000 psi. This is between the yield strength and the ultimate tensile strength, indicating that some local deformation and concrete cracking could possibly occur for sustained loading of such magnitude, depending on the extent to which the actual yield strength of the affected members exceeded the minimum specified value, but that no extensive structural failure and no structural collapse would occur.

Both the yield strength of the steel and the compressive strength of the concrete will actually be much greater for the pulse loading of the blast, which falls nearly linearly to zero from the initial overpressure over a time duration of 0.5 seconds, as determined by the referenced computer. It can be inferred from Figures 6-2 and 6-5 of the Air Force Design Manual (Ref. 13) that the short-term minimum yield strength would not be exceeded under these conditions. Considering also the attenuation effects due to partial submergence of the explosion source at the time of detonation, it may be concluded that there would actually be no local deformation whatever.

In any case, the free-standing containment vessel within the shield building would be unaffected, as would the components of the reactor system within the containment.

The control room should readily survive the postulated blast without injury to its occupants. The entire room is enclosed with two-foot thick concrete walls, except for the north wall which is 18 inches thick, and it is surrounded by other structures.

Conservative application of the linear and rotational components of tornado velocities for those areas of the structure that would be exposed to the blast has effectively resulted in design for a 2-1/4 psi internal loading, plus allowance for missiles and earthquakes. The reinforcement in the structure is symmetrical and it can be concluded that the design is also adequate for such pressure loading applied externally.

Similarly, it can be concluded that the massive structure of the spent fuel storage area would be unaffected.

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Damage may be expected to occur to light external structures that are exposed to the blast. In particular, the metal siding and roof decking of certain structures such as the turbine building would be blown off, consistent with the intent of their design with regard to tornado forces. Extensive minor damage would be expected to occur throughout the plant and switchyard.

Despite such superficial and repairable damage to the plant from an occurrence for which it was not specifically designed, no reduction in effectiveness would be expected for either the containment system or the engineered safety features that are provided to respond to a nuclear accident. The only realistic concern is that the blast could cause a nuclear accident or incapacitate the operators before they can accomplish an orderly shutdown.

No consequence of the postulated explosion is foreseen that would either initiate a nuclear accident or prevent safe shutdown of the plant.

2.9.3 Vulnerability of Cooling Water Intakes to Barge Collision

Plant safety with regard to continued availability of cooling water supply requires only that there be sufficient flow to satisfy normal shutdown and post-accident requirements.

Such assurance is provided by redundancy and reliability of adequate sources of cooling water supply.

The possible consequences of a storm-driven or flood-driven barge colliding with any structure or earthwork related to the plant are therefore of interest only to the extent that such collision might conceivably disable all redundant sources of supply.

The post-shutdown or post-accident supply paths of interest are those to the five cooling water pumps, any one of which can accommodate the total demand for both units with an accident having occurred in one and Mode 3, Hot Standby in the other. Two means of supply of intake canal water are provided for the safeguards pumps. Two horizontal pumps take suction from the main intake bays in the screenhouse, and three vertical pumps take suction from a safeguards bay in the screenhouse. The safeguards bay is a concrete structure enclosed on all sides and normally supplied by underwater ports on each side of the structure which are open to the water in the other bays. This island structure is located well back in the screenhouse and is protected on the canal side by the massive concrete piers that define the other bays.

The safeguards bay has further redundancy of supply in that it can also be fed by the emergency intake line described in Section 10.4. This source of supply is delivered through underground piping which becomes embedded within the piers, and is particularly invulnerable to any barge accident condition. The pipe is buried approximately 40 feet below the canal and emerges at a submerged intake in the branch channel of the river between the intake canal and the approach canal (see Figure 10.4-3). The intake terminal protrudes four feet upward from its crib structure, which is depressed relative to the two canals such that the highest elevation of the intake is below the bottom of the two canals.

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To disable all supplies of cooling water, an accident would have to result in concurrently blocking the intake screenhouse structure screens and totally damaging or blocking the emergency intake structure. Screen bypass gates are provided in the intake screenhouse and the emergency intake structure is designed and located to preclude total blocking by the postulated barge accident. There is no credible way in which an uncontrolled barge could cause total loss of necessary cooling water supply capability.

2.9.4 Toxic Chemical Study

Due to the toxicity of commonly used chemicals, which may be transported near the Prairie Island Nuclear Generating Plant by railroad, highway or the Mississippi River, periodic chemical surveys and control room habitability analyses are performed to determine the potential effects of a chemical spill on the control room operators. The surveys and analyses are performed in conformance with the guidance set forth by the Nuclear Regulatory Guide 1.78 and NUREG 0570. (Ref. 32)

Due to design changes, chlorine is no longer stored onsite and regulations requiring early warning of onsite chlorine releases no longer apply. Recognizing that removal of onsite chlorine may eliminate the need for the control room HVAC chlorine detectors a license amendment was requested to delete the chlorine detection system. (Ref. 23)

The license amendment was subsequently approved by the NRC. (Ref. 24)

Installation of the natural gas supply line in the west plant area elicits the need to account for a natural gas release, for its effect on control room habitability and operation of emergency diesel generator. Using U.S. NRC Regulatory Guide 1.78, Revision 1 methodology, references 36 and 37 determine that natural gas released from this supply line will not result in natural gas concentrations in the control room or near the diesel generator combustion air intakes, security diesel intakes or intakes for the diesel driven cooling water pumps that challenge the environments for habitability or operation.

Potential hazardous releases from all identified sources need not be considered in the design of the plant and no special control room HVAC detectors are required. Table 2.9-1 lists the chemicals which were considered. Table 2.9-1 is updated periodically to evaluate any changes in stored or transported toxic chemicals.

2.9.5 Blast Release from Natural Gas Supply Line

A Blast Analysis (Ref. 35) was performed to estimate the blast load effects that could potentially threaten the plant structures, systems and components (SSCs) important to safety in the event of a gas Vapor Cloud Explosion (VCE). A VCE could occur in the event of delayed ignition of flammable gas or vapor released from a postulated leak in the gas line. A VCE explosion would result in a pressure wave that manifests a certain distance from the place of ignition. This pressure wave has the potential to damage any SSCs that are within the envelope of the pressure wave. This Blast Analysis implements the methodology found in US NRC Regulatory Guide 1.91, Rev. 2, Evaluations of Explosions Postulated to Occur at Nearby Facilities and on Transportation Routes Near Nuclear Power Plants (RG 1.91, Ref. 38).

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In order to determine the maximum blast pressure using RG 1.91 methodology, a full guillotine break was assumed at any location along the planned gas line routing. The flammable mass contained in the vapor cloud was estimated based on the full bore release size and the release was considered to be pure methane. Once the amount of material release was determined, the energy in the vapor cloud was calculated and the mass of flammable material was converted into an equivalent mass of TNT. This TNT equivalent was then used to determine the 1-psi incident pressure distance.

The 1 psi blast effect distances were then mapped graphically. The boundaries of the 1 psi blast contour and its location relative to plant structures was determined. This map shows that no plant SSCs inside the protected area would be affected by this 1 psi pressure wave. However it does show that a portion of the sub-station could be affected by this pressure wave. It was determined that the postulated explosion could affect electrical systems resulting in a Loss Of Offiste Power (LOOP) event, although the frequency of such an event was found to be less than minimal. Since it is unknown what kind of affect the blast wave would have on the sub-station components it was assumed that this could possibly result in a loss of offsite power event.

2.9.6 Summary of Analysis of Effects of Local Disasters The possible consequences of various hypothetical local disasters have been investigated and it is concluded, for the conditions or assumptions specified for each occurrence except the toxic chemical study (Reference 23), that the plant would either be relatively unaffected in its operation or that it could safely be shutdown without initiation of a nuclear accident.

These conclusions are not entirely surprising in view of the plant design requirements which include the effects of earthquakes, floods, tornadoes, and gross release of radioactivity. Once designed consistent with these requirements, the plant is found to be relatively invulnerable to lesser local disasters, even though its design has not specifically anticipated their occurrence.

It is noted with some concern, however, that the relevance of vulnerability of any nuclear plant to the more severe offsite catastrophes that can be postulated is questionable. As in the Texas City-type explosion, the role of the nuclear plant would essentially be that of victim rather than potential offender. The direct consequences of such an accident would reasonably be expected to exceed greatly in severity any likely secondary consequences of a nuclear accident that might be provoked by the blast, provided such secondary consequences were evaluated consistent with the assumed reality of the primary event. With engineered safety features presumed to be effective unless they are directly affected by the disaster, and with activity release, if any, considered on the basis of reasonable expectation, the predicted nuclear consequences would be relatively minor.

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The more severe consequences of a nuclear accident that are predicted on the traditional basis of sequential conservative assumptions, and which we apply to the nuclear plant when it is regarded by itself as a potential offender, would not logically be applied to overall evaluation of a composite accident, the severe primary consequences of which are directly predictable and not a matter of consistently conservative assumption.

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2.10 REFERENCES

1. Thom, H. C. S., Tornado Probabilities, Monthly Weather Review, Vol. 91, No. 10-12, pp. 730-736.

2. Flora, S. D., Tornadoes of the United States, University of Oklahoma, 1954.

3. Hoecker, W. H., Wind Speed and Flow Patterns in the Dallas Tornado of April 2, 1957, Monthly Weather Review, May, 1960, and December, 1961.

4. Booker, C. A., Tower Damage Provides Key to Worcester Tornado Data, Electrical World, August 17, 1953.

5. Silberg, P. A., On the Nature of Tornadoes, Raytheon Co., June, 1961.

6. Hoecker, W. H., Three-Dimensional Pressure Pattern of the Dallas Tornado and Some Resultant Implications, Monthly Weather Review, December, 1961.

7. The Topeka Kansas Tornado, Engineering News Record, April, 1966.

8. Brooks, E. N., Compendium of Meteorology, American Meteorological Society, 1951.

9. Gloser, A., Tornado Studies, Texas A & M Department of Oceanography and Meteorology Contract Cqb 8696, 1956.

10. Offsite Dose Calculation Manual, Revision 1, L. O. Mayer (NSP) to Director NRR, April 15, 1980.

11. Seed and Lee, Liquefaction of Saturated Sands During Cyclic Loading, Journal of Soil Mechanics and Foundation Division, ASCE, Vol. 91, No. SM6, November 1966.

12. The Effects of Nuclear Weapons, Dept. of Defense and AEC, April 1962.

13. AFSWC - TDR-62-138, Air Force Design Manual December 1962, Air Force Special Weapons Center.

14. Deleted

15. Letter, Dominic C. DiIanni (NRC) to L O Mayer (NSP), February 26, 1982.

(18311/1663)

16. Letter, Dominic C. DiIanni (NRC) to D M Musolf (NSP), October 21, 1982.

(18312/1523)

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 44 of 80

17. Deleted

18. Deleted

19. MIDAS, Meteorological Information and Dose Assessment System; Pickard, Lowe, Garrick, Inc.

20. National Oceanic and Atmospheric Administration, Local Climatological Data, Minneapolis-St. Paul, Minnesota, July 1987.

21. Deleted

22. Deleted

23. Letter, T M Parker (NSP) to US Nuclear Regulatory Commission, License Amendment Request dated December 13, 1991, Removal of Chlorine Detection Requirements, December 13, 1991. (2211/1480) (2861/2465)

24. Letter, William 0. Long (NRC) to T. M. Parker (NSP), Amendment Nos.102 And 95 To Facility Operating License Nos. DPR-42 AND DPR-60 (TAC NOS.

M82518 AND M82519), September 29, 1992.

25. KLD Engineering, P.C., Evacuation Time Estimate for the Prairie Island Nuclear Generating Plant Emergency Planning Zone, November 2012.

26. Quarternary Tectonics in Middle North America P. B. King in Quarternary of the U.S. edited by H. E. Wright, Jr. and D. G. Fry, The Princeton University Press, 1965.

27. Letter, GV Welk (NSP) to Col. RE Cox (Corps of Engineers), Authorization To Evacuate Area, August 18, 1972. (7209/0637)

28. Letter, Col. RE Cox (Corps of Engineers) to GV Welk (NSP), September 18, 1972. (7209/0634)

29. Prairie Island Nuclear Generating Plant, Emergency Plan.

30. National Pollutant Discharge Elimination System (NPDES)/State Disposal System (SDS) Water Quality Permit - MN 0004006

31. Prairie Island NGP Calculation, ENG-ME-603, Evaluation of the Effects of the Rupture of a Liquid Nitrogen Tank on Control Room Habitability, Rev. 0.

32. Calculation GEN-PI-076, Control Room Habitability Analyses for Offsite Hazardous Chemical Release.

33. Analysis of Hydrogen Toxicity Hazard at PINGP, Vendor Calc. #2008-10838

34. Letter, D. Gilberts to J. Keppler (NRC), Emergency Preparedness Appraisal Response, January 15, 1982.

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35. PI-53354-M02, "Analysis Report of Postulated Vapor Cloud Explosions from Natural Gas Line Installation," Rev. 0

36. PI-53354-M03, "Analysis Report Determining Potential Natural Gas Vapor Cloud Concentration Levels," Rev. 0

37. PI-53354-M04, "Control Room Habitability and Diesel Generator Operability Following a Natural Gas Release," Rev. 0

38. U.S. Nuclear Regulatory Commission (USNRC) Regulatory Guide 1.91, April 2013, Revision 2, Evaluation of Explosions

39. U.S. Nuclear Regulatory Commission (US NRC) Regulatory Guide 1.78 December 2001, Revision 1, Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazard Chemical Release

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TABLE 2.2-1 ESTIMATED 2010 RESIDENT POPULATION DISTRIBUTION WITHIN THE PRAIRIE ISLAND EMERGENCY PLANNING ZONE (REFERENCE 25)

Radius N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW TOTAL (MILES)

0-1 0 0 0 0 0 0 0 0 0 0 0 0 6 164 0 22 192

1-2 27 34 74 0 6 0 0 0 0 21 0 13 0 20 11 0 206

2-3 23 75 75 12 4 0 0 0 7 20 23 30 0 0 0 1 270

3-4 16 59 30 2 165 137 0 614 458 111 1 40 68 84 0 0 1,785

4-5 20 21 35 34 50 148 476 901 281 0 17 30 45 5 0 13 2,076

5-6 77 35 120 80 172 296 1,445 677 4 35 75 0 99 218 46 117 3,496

6-7 6 169 101 48 38 601 6,655 56 48 73 57 98 239 331 0 0 8,520

7-8 171 59 166 74 223 331 4,113 146 44 43 51 53 162 461 146 658 6,901

8-9 86 166 148 106 41 265 127 107 17 114 57 91 115 593 176 106 2,315

9-10 288 260 290 82 24 484 136 78 62 108 98 100 89 109 297 224 2,729

10-11* 70 394 276 17 78 8 45 12 8 57 74 35 0 595 52 264 1,985

TOTAL 784 1,272 1,315 455 801 2,270 12,997 2,591 929 582 453 490 823 2,580 728 1,405 30,475

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

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TABLE 2.3-1 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS A (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 1 7 2 0 0 0 10 NNE 4 5 2 0 0 0 11 NE 2 5 3 0 0 0 10 ENE 2 8 7 0 0 0 17 E 1 15 21 0 0 0 37 ESE 0 10 25 4 1 0 40 SE 0 3 0 1 0 0 4 SSE 1 3 6 3 0 0 13 S 0 2 16 2 0 0 20 SSW 0 5 5 3 0 0 13 SW 1 2 3 3 0 0 9 WSW 1 3 4 1 0 0 9 W 0 7 12 5 0 0 24 WNW 0 10 17 10 0 0 37 NW 1 17 23 18 1 0 60 NNW 0 7 17 2 0 0 26 TOTAL 14 109 163 52 2 0 340

PERCENT OF ALL DATA THIS CLASS: 3.88%

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TABLE 2.3-2 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS B (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 1 4 2 1 0 0 8 NNE 0 7 1 0 0 0 8 NE 1 5 3 0 0 0 9 ENE 0 2 1 0 0 0 3 E 0 13 21 1 0 0 23 ESE 1 7 12 2 0 0 22 SE 0 3 4 1 0 0 8 SSE 1 3 12 4 0 0 20 S 0 8 17 3 0 0 28 SSW 0 4 13 3 0 0 20 SW 2 2 5 2 0 0 11 WSW 0 2 4 1 0 0 7 W 0 6 6 1 0 0 13 WNW 0 12 26 8 0 0 46 NW 0 13 17 10 2 0 42 NNW 1 10 5 2 0 0 8 TOTAL 7 101 137 39 2 0 286

PERCENT OF ALL DATA THIS CLASS: 3.26%

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TABLE 2.3-3 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS C (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTA DIRECTION L N 1 7 2 1 0 0 11 NNE 1 15 0 0 0 0 16 NE 2 3 0 0 0 0 5 ENE 3 6 4 0 0 0 13 E 2 25 7 2 0 0 36 ESE 2 11 20 6 0 0 39 SE 2 2 4 7 0 0 15 SSE 2 5 14 3 0 0 24 S 1 6 23 2 0 0 32 SSW 1 8 14 1 0 0 24 SW 1 7 7 8 0 0 23 WSW 0 6 7 3 0 0 16 W 1 9 6 4 0 0 20 WNW 1 16 14 5 1 0 37 NW 1 19 21 11 3 0 55 NNW 3 15 8 1 0 0 27 TOTAL 24 160 151 54 4 0 393

PERCENT OF ALL DATA THIS CLASS: 4.49%

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TABLE 2.3-4 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS D (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 19 67 27 5 0 0 118 NNE 30 47 5 0 0 0 82 NE 41 64 16 2 0 0 123 ENE 28 68 32 3 0 0 121 E 25 192 127 30 0 0 375 ESE 11 73 222 130 13 0 449 SE 12 103 91 27 3 0 236 SSE 19 91 92 26 0 0 228 S 18 79 115 10 0 0 222 SSW 14 59 55 9 0 0 137 SW 16 39 30 21 0 0 106 WSW 8 51 44 17 1 0 121 W 17 76 129 61 3 0 286 WNW 23 106 139 85 5 0 358 NW 28 84 132 108 20 0 372 NNW 26 79 66 25 2 0 198 TOTAL 335 1278 1322 559 47 0 3542

PERCENT OF ALL DATA THIS CLASS: 40.43%

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TABLE 2.3-5 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS E (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 37 26 19 1 0 0 85 NNE 35 16 4 1 0 0 57 NE 31 27 1 0 0 0 59 ENE 50 42 7 0 0 0 101 E 85 174 29 6 0 0 294 ESE 65 181 100 22 4 0 374 SE 44 237 125 16 3 0 423 SSE 50 115 69 12 0 0 249 S 33 101 120 4 0 0 260 SSW 21 40 43 5 0 0 109 SW 28 27 27 9 0 0 91 WSW 37 40 22 7 3 0 109 W 74 145 52 21 4 0 297 WNW 79 173 93 47 2 0 394 NW 72 138 77 38 1 0 327 NNW 50 37 28 7 0 0 124 TOTAL 791 1519 816 196 14 0 3353

PERCENT OF ALL DATA THIS CLASS: 38.28%

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TABLE 2.3-6 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS F (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 15 1 0 0 0 0 17 NNE 10 0 0 0 0 0 11 NE 12 0 0 0 0 0 12 ENE 23 4 0 0 0 0 27 E 38 16 2 0 0 0 58 ESE 43 19 0 0 0 0 62 SE 34 13 0 0 3 0 48 SSE 29 9 2 0 0 0 42 S 10 3 0 0 0 0 13 SSW 11 2 0 0 0 0 13 SW 17 6 0 0 0 0 25 WSW 25 7 0 0 0 0 32 W 40 11 2 0 0 0 53 WNW 73 45 3 0 0 0 121 NW 47 23 1 0 0 0 71 NNW 29 2 0 0 0 0 31 TOTAL 456 161 10 0 0 0 636

PERCENT OF ALL DATA THIS CLASS: 7.26%

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TABLE 2.3-7 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY CLASS G (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 2 0 0 0 0 0 2 NNE 5 0 0 0 0 0 7 NE 4 0 0 0 0 0 4 ENE 5 2 0 0 0 0 9 E 16 10 0 0 0 0 29 ESE 14 4 0 0 0 0 19 SE 22 2 0 0 3 0 24 SSE 12 1 0 0 0 0 14 S 11 0 0 0 0 0 11 SSW 4 1 0 0 0 0 5 SW 4 0 0 0 0 0 4 WSW 9 0 0 0 0 0 9 W 12 1 0 0 0 0 13 WNW 20 9 0 0 0 0 29 NW 23 2 0 0 0 0 26 NNW 4 1 0 0 0 0 5 TOTAL 167 33 0 0 0 0 210

PERCENT OF ALL DATA THIS CLASS: 2.40%

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TABLE 2.3-8 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY ALL CLASSES COMBINED (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA (Page 1 of 2)

WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTA DIRECTION L N 76 112 52 8 0 0 251 NNE 85 90 12 1 0 0 192 NE 93 104 23 2 0 0 222 ENE 111 132 51 3 0 0 301 E 167 445 195 39 0 0 852 ESE 136 305 379 164 18 0 1005 SE 114 363 224 52 3 0 758 SSE 114 227 195 48 0 0 590 S 73 199 291 21 0 0 586 SSW 51 119 130 21 0 0 321 SW 69 83 72 43 0 0 269 WSW 80 109 81 29 4 0 303 W 144 255 207 92 7 0 706 WNW 196 371 292 155 8 0 1022 NW 172 296 271 185 27 0 953 NNW 113 151 124 37 2 0 429 TOTAL 1794 3361 2599 900 69 0 760

HOURS OF CALM TOTAL: 41 HOURS OF MISSING DATA: 0 HOURS WITH VARIABLE DIRECTION: 0 PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 56 of 80

TABLE 2.3-8 JOINT FREQUENCY DISTRIBUTIONS AT 10 METERS, STABILITY ALL CLASSES COMBINED (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA (Page 2 of 2)

Percent Occurrence in each Stability Class

Class A 3.88%

Class B 3.26%

Class C 4.49%

Class D 40.43%

Class E 38.28%

Class F 7.26%

Class G 2.40%

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TABLE 2.3-9 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS A (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 1 3 3 0 0 0 7 NNE 0 3 3 1 0 0 7 NE 1 3 5 2 0 0 11 ENE 1 5 6 2 0 0 14 E 1 15 19 4 0 0 39 ESE 1 5 22 10 2 0 40 SE 0 1 1 1 0 0 3 SSE 0 3 5 8 0 0 16 S 0 1 11 6 0 0 18 SSW 1 3 5 5 0 0 14 SW 0 2 1 3 2 0 8 WSW 0 2 5 1 1 0 9 W 0 3 14 7 6 1 31 WNW 1 6 10 14 5 0 36 NW 1 5 26 13 14 1 60 NNW 1 7 9 9 1 0 27 TOTAL 9 67 145 86 31 2 340

PERCENT OF ALL DATA THIS CLASS: 3.88%

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TABLE 2.3-10 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS B (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 0 4 0 0 0 0 4 NNE 3 5 1 1 0 0 10 NE 0 5 3 1 0 0 9 ENE 0 1 1 1 0 0 3 E 0 7 10 2 1 0 20 ESE 0 2 15 4 1 0 22 SE 0 3 10 0 3 0 16 SSE 1 0 12 3 3 0 19 S 0 3 16 6 1 0 26 SSW 0 1 6 8 1 0 16 SW 0 2 2 7 1 0 12 WSW 0 1 6 1 0 0 8 W 0 2 5 3 3 0 13 WNW 0 9 23 11 5 3 51 NW 0 5 16 12 3 1 37 NNW 0 9 5 5 1 0 20 TOTAL 4 59 131 65 23 4 286

PERCENT OF ALL DATA THIS CLASS: 3.26%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 59 of 80

TABLE 2.3-11 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS C (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 1 10 1 1 1 0 14 NNE 5 7 2 0 0 0 14 NE 1 2 0 0 0 0 3 ENE 1 6 6 4 0 0 17 E 1 15 12 3 2 0 33 ESE 1 4 22 7 4 0 38 SE 0 4 6 4 4 0 18 SSE 0 0 10 9 2 0 21 S 1 6 15 14 0 0 36 SSW 2 2 8 9 1 0 22 SW 0 5 4 8 2 0 19 WSW 0 4 7 2 1 1 15 W 0 7 7 6 3 2 25 WNW 2 10 9 12 4 0 37 NW 1 13 19 13 6 3 55 NNW 1 11 10 3 1 0 26 TOTAL 17 106 138 95 31 6 393

PERCENT OF ALL DATA THIS CLASS: 4.49%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 60 of 80

TABLE 2.3-12 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS D (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 10 41 33 14 2 0 100 NNE 15 42 32 2 1 0 92 NE 16 47 32 15 2 0 112 ENE 10 54 47 24 7 0 142 E 11 99 136 78 25 1 350 ESE 12 56 163 132 79 13 455 SE 13 57 125 50 17 2 264 SSE 15 39 92 64 13 0 223 S 7 57 101 58 4 0 227 SSW 3 36 47 35 8 0 129 SW 9 32 34 23 10 0 108 WSW 10 27 59 24 7 1 128 W 7 49 93 110 53 9 321 WNW 15 45 100 130 65 15 370 NW 21 41 64 98 62 28 314 NNW 21 46 67 58 15 0 207 TOTAL 195 768 1225 915 370 69 3542

PERCENT OF ALL DATA THIS CLASS: 40.43%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 61 of 80

TABLE 2.3-13 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS E (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 10 25 22 14 4 0 75 NNE 15 26 19 6 0 0 66 NE 25 30 20 2 0 0 77 ENE 18 23 21 7 1 0 70 E 21 87 77 19 25 1 210 ESE 28 147 166 54 79 4 418 SE 41 133 223 85 17 0 493 SSE 22 69 115 43 13 0 260 S 13 61 102 85 4 0 265 SSW 10 23 36 39 8 0 113 SW 9 26 27 24 10 1 92 WSW 15 45 43 27 7 3 139 W 21 89 139 64 53 4 336 WNW 22 72 116 108 65 6 378 NW 14 55 93 84 62 1 267 NNW 13 31 30 18 15 0 94 TOTAL 297 942 1249 679 162 20 3353

PERCENT OF ALL DATA THIS CLASS: 38.28%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 62 of 80

TABLE 2.3-14 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS F (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 8 5 0 0 0 0 13 NNE 6 3 1 0 0 0 10 NE 6 5 1 0 0 0 12 ENE 10 4 0 0 0 0 14 E 10 12 2 0 0 0 24 ESE 10 55 32 1 0 0 98 SE 24 33 21 1 0 0 80 SSE 9 7 1 1 0 0 18 S 11 8 1 0 0 0 22 SSW 6 3 0 0 0 0 9 SW 15 6 3 1 0 0 25 WSW 8 15 4 0 0 0 27 W 18 29 17 1 1 0 66 WNW 11 30 54 8 1 0 106 NW 14 43 22 5 0 0 84 NNW 10 13 5 0 0 0 28 TOTAL 176 271 164 18 2 0 636

PERCENT OF ALL DATA THIS CLASS: 7.26%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 63 of 80

TABLE 2.3-15 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY CLASS G (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 0 0 0 0 0 0 0 NNE 2 1 0 0 0 0 3 NE 1 1 0 0 0 0 3 ENE 1 0 0 0 0 0 1 E 1 1 0 0 0 0 2 ESE 4 19 4 0 0 0 27 SE 5 21 5 0 0 0 31 SSE 4 7 1 0 0 0 12 S 4 7 0 0 0 0 11 SSW 10 2 1 0 0 0 13 SW 7 3 0 0 0 0 10 WSW 3 7 1 0 0 0 11 W 7 9 2 0 0 0 18 WNW 6 16 14 1 0 0 37 NW 3 16 8 0 0 0 27 NNW 0 4 0 0 0 0 4 TOTAL 58 114 36 1 0 0 210

PERCENT OF ALL DATA THIS CLASS: 2.40%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 64 of 80

TABLE 2.3-16 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY ALL CLASSES COMBINED (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA (Page 1 of 2)

WIND SPEED (MPH)

WIND 1-3 4-7 8-12 13-18 19-24 >24 TOTAL DIRECTION N 30 88 59 29 7 0 213 NNE 46 87 58 10 1 0 202 NE 50 93 61 20 2 0 227 ENE 41 93 81 38 8 0 261 E 45 236 256 106 32 2 678 ESE 56 288 424 208 105 17 1098 SE 83 252 391 141 35 2 905 SSE 51 125 236 128 29 0 569 S 36 143 246 169 8 0 605 SSW 32 70 103 96 15 0 316 SW 40 76 71 66 20 1 274 WSW 36 101 125 55 15 5 337 W 53 188 277 191 84 16 810 WNW 57 188 326 284 134 24 1015 NW 54 178 248 225 105 34 844 NNW 46 121 126 93 19 0 406 TOTAL 756 2327 3088 1859 619 101 8760

HOURS OF CALM TOTAL: 25 HOURS OF MISSING DATA: 0 HOURS WITH VARIABLE DIRECTION: 0 PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 65 of 80

TABLE 2.3-16 JOINT FREQUENCY DISTRIBUTIONS AT 60 METERS, STABILITY ALL CLASSES COMBINED (HOURS AT EACH WIND SPEED AND DIRECTION) 1991 DATA (Page 2 of 2)

Percent Occurrence in each Stability Class

Class A 3.88%

Class B 3.26%

Class C 4.49%

Class D 40.43%

Class E 38.28%

Class F 7.26%

Class G 2.40%

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 66 of 80

Table 2.3-17 ANNUAL AVERAGE DISPERSION FACTOR (__/Q) 1991 DATA For Release Point 1, Building Vents Annual Ground Average __/Q (Sec/m3)

DISTANCE IN MILES

Direction 0.5 1.5 2.5 3.5 4.5 7.5 15 25 35 45 N 1.4569E-06 2.9406E-07 1.3898E-07 8.2836E-08 5.8196E-08 2.9101E-08 1.1268E-08 5.5804E-09 3.5619E-09 2.5544E-09 NNE 1.5352E-06 2.9433E-07 1.3925E-07 8.4574E-08 5.9972E-08 3.0474E-08 1.2087E-08 6.0402E-09 3.8715E-09 2.8040E-09

NE 1.4247E-06 2.7854E-07 1.3061E-07 7.8058E-08 5.4776E-08 2.7275E-08 1.0518E-08 5.1858E-09 3.2958E-09 2.3596E-09 ENE 2.0911E-06 4.1381E-07 1.9629E-07 1.1839E-07 8.3723E-08 4.2357E-08 1.6676E-08 8.3099E-09 5.3191E-09 3.8383E-09 E 4.5640E-06 8.9561E-07 4.2480E-07 2.5677E-07 1.8173E-07 9.2069E-08 3.6334E-08 1.8122E-08 1.1605E-08 8.3822E-09 ESE 4.1136E-06 8.1691E-07 3.8905E-07 2.3496E-07 1.6629E-07 8.4258E-08 3.3264E-08 1.6611E-08 1.065E-08 7.6919E-09 SE 4.0346E-06 7.9787E-07 3.7950E-07 2.3048E-07 1.6405E-07 8.4088E-08 3.3597E-08 1.6828E-08 1.0800E-08 7.8328E-09

SSE 3.1943E-06 6.3196E-07 3.0154E-07 1.8268E-07 1.2949E-07 6.5792E-08 2.6078E-08 1.3043E-08 8.3689E-09 6.0520E-09 S 2.5327E-06 5.0213E-07 2.3484E-07 1.4043E-07 9.9226E-08 5.0248E-08 1.9685E-08 9.7643E-09 6.2315E-09 4.4923E-09 SSW 1.4161E-06 2.7870E-07 1.3145E-07 7.8821E-08 5.5530E-08 2.7901E-08 1.0885E-08 5.4059E-09 3.4550E-09 2.4868E-09 SW 1.5642E-06 3.0634E-07 1.4800E-07 9.0273E-08 6.3950E-08 3.2386E-08 1.2869E-08 6.4656E-09 4.1632E-09 3.0134E-09 WSW 1.9328E-06 3.7676E-07 1.8249E-07 1.1197E-07 7.9620E-08 4.0596E-08 1.6268E-08 8.1933E-09 5.2797E-09 3.8312E-09

W 3.2843E-06 6.5951E-07 3.1290E-07 1.8820E-07 1.3315E-07 6.7512E-08 2.6596E-08 1.3257E-08 8.4894E-09 6.1262E-09 WNW 4.6477E-06 9.1779E-07 4.4245E-07 2.6943E-07 1.9110E-07 9.7098E-08 3.8645E-08 1.9410E-08 1.2492E-08 9.0444E-09 NW 4.0554E-06 7.9646E-07 3.7855E-07 2.2897E-07 1.6218E-07 8.2301E-08 3.2561E-08 1.6274E-08 1.0439E-08 7.5486E-09 NNW 2.1511E-06 4.2964E-07 2.0336E-07 1.2158E-07 8.5501E-08 4.2820E-08 1.6642E-08 8.2662E-09 5.2830E-09 3.7961E-09

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 67 of 80

TABLE 2.3-18 RELATIVE DISPERSION PER UNIT AREA (D/Q) 1991 DATA

For Release Point 1, Building Vents Annual Average D/Q (1/m2)

DISTANCE IN MILES

Direction 0.5 1.5 2.5 3.5 4.5 7.5 15 25 35 45 N 5.8255E-09 8.9269E-10 4.0369E-10 2.1189E-10 1.3524E-10 5.6487E-11 1.8392E-11 6.7715E-12 3.6142E-12 2.2706E-12 NNE 4.4562E-09 6.8285E-10 3.0880E-10 1.6209E-10 1.0345E-10 4.3209E-11 1.4068E-11 5.1798E-12 2.7646E-12 1.7368E-12 NE 5.1524E-09 7.8955E-10 3.5705E-10 1.8741E-10 1.1961E-10 4.9960E-11 1.6267E-11 5.9891E-12 3.1966E-12 2.0082E-12

ENE 6.9860E-09 1.0705E-09 4.8411E-10 2.5411E-10 1.6218E-10 6.7739E-11 2.2055E-11 8.1204E-12 4.3341E-12 2.7229E-12 E 1.9774E-08 3.0302E-09 1.3703E-09 7.1926E-10 4.5905E-10 1.9174E-10 6.2429E-11 2.2985E-11 1.2268E-11 7.7073E-12 ESE 2.3326E-08 3.5743E-09 1.6164E-09 8.4842E-10 5.4149E-10 2.6217E-10 7.3640E-11 2.7113E-11 1.4471E-11 9.0914E-12 SE 1.7593E-08 2.6958E-09 1.2191E-09 6.3991E-10 4.0840E-10 1.7059E-10 5.5541E-11 2.0449E-11 1.0915E-11 6.8569E-12 SSE 1.3693E-08 2.0983E-09 9.4892E-10 4.9808E-10 3.1789E-10 1.3278E-10 4.3231E-11 1.5917E-11 8.4955E-12 5.3372E-12

S 1.3601E-08 2.0841E-09 9.4248E-10 4.9471E-10 3.1573E-10 1.3188E-10 4.2938E-11 1.5809E-11 8.4379E-12 5.3010E-12 SSW 7.4501E-09 1.1416E-09 5.1627E-10 2.7099E-10 1.7295E-10 7.2240E-11 2.3521E-11 8.6599E-12 4.6221E-12 2.9039E-12 SW 6.2433E-09 9.5670E-10 4.3264E-10 2.2709E-10 1.4493E-10 6.0537E-11 1.9711E-11 7.2571E-12 3.8734E-12 2.4334E-12 WSW 7.0324E-09 1.0776E-09 4.8732E-10 2.5579E-10 1.6325E-10 6.8189E-11 2.2202E-11 8.1743E-12 4.3629E-12 2.7410E-12 W 1.6386E-08 2.5109E-09 1.1355E-09 5.9601E-10 3.8039E-10 1.5888E-10 5.1731E-11 1.9046E-11 1.0166E-11 6.3865E-12

WNW 2.3720E-08 3.6348E-09 1.6437E-09 8.6277E-10 5.5064E-10 2.3999E-10 7.4885E-11 2.7571E-11 1.4716E-11 9.2452E-12 NW 2.2119E-08 3.3894E-09 1.5327E-09 8.0452E-10 5.1347E-10 2.1447E-10 6.9830E-11 2.5710E-11 1.3722E-11 8.6210E-12 NNW 9.9567E-09 1.5257E-09 6.8997E-10 3.6217E-10 2.3114E-10 9.6545E-11 3.1434E-11 1.1574E-11 6.1772E-12 3.8808E-12

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 68 of 80

TABLE 2.3-19 SITE BOUNDARY X/Q AND D/Q

BUILDING VENTS CORRECTED FOR OPEN TERRAIN RECIRCULATION SPECIFIC POINTS OF INTEREST

DISTANCE X/Q X/Q X/Q D/Q RELEASE TYPE OF DIRECTION (MILES) (METERS) (SEC/CUB METER) (SEC/CUB METER) (SEC/CUB METER) (PER SQ. METER ID LOCATION NO DECAY 2.260 DAY DECAY 8.000 DAY DECAY UNDEPLETED UNDEPLETED DEPLETED V SITE BOUNDARY S 0.43 692. 8.84E-06 8.78E-06 8.13E-06 3.46E-08

V SITE BOUNDARY SSW 0.40 644. 9.86E-06 9.80E-06 9.11E-06 3.68E-08 V SITE BOUNDARY SW 0.40 644. 9.79E-06 9.72E-06 9.04E-06 3.45E-08 V SITE BOUNDARY WSW 0.37 595. 1.62E-05 1.61E-05 1.50E-05 5.44E-08 V SITE BOUNDARY W 0.36 579. 2.76E-05 2.74E095 2.56E-05 1.06E-07 V SITE BOUNDARY WNW 0.36 579. 2.39E-05 2.38E-05 2.22E-05 9.97E-08

V SITE BOUNDARY NW 0.43 692. 1.88E-05 1.87E-05 1.73E-05 7.84E-08 V SITE BOUNDARY NNW 0.48 772. 1.11E-05 1.11E-05 1.02E-05 5.82E-08 V SITE BOUNDARY N 0.28 451. 2.04E-05 2.03E-05 1.92E-05 9.65E-08 V SITE BOUNDARY NNE 0.26 418. 1.91E-05 1.90E-05 1.80E-05 7.40E-08 V SITE BOUNDARY NE 0.84 1352. 2.82E-06 2.78E-06 2.49E-06 9.70E-09

V SITE BOUNDARY ENE 0.62 998. 1.01E-05 9.99E-06 9.06E-06 4.24E-08 V SITE BOUNDARY E 0.59 950. 1.33E-05 1.32E-05 1.20E-05 3.80E-08 V SITE BOUNDARY ESE 0.61 982. 1.76E-05 1.75E-05 1.59E-05 5.87E-08 V SITE BOUNDARY SE 0.67 1078. 1.75E-05 1.74E-05 1.57E-05 5.99E-08 V SITE BOUNDARY SSE 0.43 692. 2.00E-05 1.98E-05 1.84E-05 7.16E-08

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 69 of 80

TABLE 2.4-1 MINIMUM CONSECUTIVE-DAY LOW-FLOW, IN CFS, FOR THE FIVE LOWEST YEARS OF RECORD

1 Day (Year) 7 Days (Year) 14 Days (Year) 30 Days (Year)

1380 (1940) 2190 (1936) 2260 (1936) 2350 (1934)

2100 (1936) 2240 (1934) 2260 (1934) 2650 (1936)

2210 (1934) 2640 (1933) 2650 (1933) 2860 (1933)

2270 (1939) 3110 (1931) 3190 (1931) 3360 (1932)

2520 (1933) 3270 (1932) 3320 (1932) 3370 (1931)

Note: Gaged at Prescott, about 15 miles upstream from site. Since no severe low flows have occurred after 1940, it is believed that construction of facilities on the river since that time assist in augmenting low flow.

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 70 of 80

TABLE 2.4-2 DISCHARGE OF MISSISSIPPI RIVER AND CANNON RIVER

MISSISSIPPI RIVER CANNON RIVER

AT PRESCOTT AT WINONA AT WELCH

AVERAGE 15,020 CFS 24,520 CFS 475 CFS

MAXIMUM 228,000 cfs 4-18-65 268,000 cfs 4-19-65 36,100 cfs 4-10-65

MINIMUM 1,380 cfs 7-13-40 3,350 cfs 12-29-33 2.5 cfs 1-3-50

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 71 of 80

TABLE 2.4-3 Page 1 of 4

WELLS IN PLANT VICINITY

Location Use

Well Fractional Sec Twp Range County Depth Diam Demand Domestic Livestock Irrigation Other No. Section (ft) (in) (gpm) of acres

1 NW 1/4, NW 1/4 9 113 15 Goodhue 50 2 ? X X

2 NW 1/4, SW 1/4 5 113 15 Goodhue 50 2 ? X X

3 NW 1/4, SW 1/4 5 113 15 Goodhue 80 4 12 to 15 X

4 SW 1/4, NW 1/4 5 113 15 Goodhue 50 2 Hand pmp X

5 NW 1/4, SE 1/4 9 113 15 Goodhue 65 4 Hand pmp X

6 NE 1/4, NE 1/4 5 113 15 Goodhue 60 4 ? River Testing Station

7 SW 1/4, SE 1/4 32 113 15 Goodhue 35 1 1/2 ? X

8 SW 1/4, SE 1/4 32 113 15 Goodhue 40 & 18 1 1/4 & 1 1/4 ? X 2

9 SW 1/4 SE 1/4 32 113 15 Goodhue

10 NW 1/4, SE 1/4 9 113 15 Goodhue 60 4 Hand pmp X Campers

11 SW 1/4, NW 1/4 10 113 15 Goodhue 595 6 ? X Lock Uses

12 SW 1/4, SE 1/4 16 113 15 Goodhue ? ? X X

13 NW 1/4, SE 1/4 16 113 15 Goodhue 60 6 ? X X

14 NE 1/4, SE 1/4 9 113 15 Goodhue 55 & 55 2 & 2 X

15 SW 1/4, SW 1/4 31 113 15 Goodhue 30 1 1/4 15 X

16 NE 1/4, NE 1/4 30 25 18 Pierce 65 4 10 to 12 X X

17 SE 1/4, NW 1/4 29 25 18 Pierce 91 6 ? X

18 SE 1/4, NW 1/4 29 25 18 Pierce 90 1 1/4 ? X X PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 72 of 80

TABLE 2.4-3 Page 2 of 4

WELLS IN PLANT VICINITY

Location Use Well Fractional Sec Twp Range County Depth Diam Demand Domestic Livestock Irrigation Other No. Section (ft) (in) (gpm) of acres 19 SW 1/4, NE 1/4 29 25 18 Pierce 45 5 ? X 20 SE 1/4, SW 1/4 28 25 189= Pierce 50 2 ? X X 21 NE 1/4, NW 1/4 33 25 18 Pierce 85 4 ? X 22 NE 1/4, NW 1/4 33 25 18 Pierce 85 4 ? X 23 SE 1/4, NW 1/4 33 25 18 Pierce 100 4 ? X X 1.5 24 SE 1/4, NW 1/4 33 25 18 Pierce 65 4 ? X 25 SE 1/4, NW 1/4 33 24 18 Pierce 30 2 ? X 26 NE 1/4, SE 1/4 33 24 18 Pierce 123 4 ? X 27 SW 1/4, NE 1/4 33 24 18 Pierce X 28 SE 1/4, NW 1/4 33 24 18 Pierce 90 4 ? X X 29 SW 1/4, NE 1/4 33 24 18 Pierce ? ? ?

30 SW 1/4, NE 1/4 33 24 18 Pierce ? ? ? X 31 NW 1/4, SE 1/4 33 24 18 Pierce 65 4 ? X 32 NW 1/4, SE 1/4 33 24 18 Pierce 160 4 ? X 33 NW 1/4, SE 1/4 33 24 18 Pierce ? ? ? X 34 NW 1/4, SE 1/4 33 24 18 Pierce 300 4 ? X 35 NW 1/4, SE 1/4 33 24 18 Pierce X X 36 SE 1/4, SE 1/4 33 24 18 Pierce X

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 73 of 80

TABLE 2.4-3 Page 3 of 4

WELLS IN PLANT VICINITY

Location Use Well Fractional Sec Twp Range County Depth Diam Demand Domestic Livestock Irrigation Other No. Section (ft) (in) (gpm) of acres 37 NW 1/4, SE 1/4 33 24 18 Pierce 20 2 12 X Minnows 38 SW 1/4, SE 1/4 33 24 18 Pierce 40 1 1/4 10 X Minnows 39 NE 1/4, NE 1/4 13 24 18 Pierce 132 4 12 to 15 X 40 NW 1/4, NW 1/4 3 24 18 Pierce 120 4 ? X 41 NW 1/4, NW 1/4 3 24 18 Pierce 65 4 12 X X 42 SE 1/4, NW 1/4 5 113 15 Goodhue 300 X Fire Protection during const.

43 SE 1/4, NW 1/4 5 113 15 Goodhue 300 X 44 SW 1/4, SE 1/4 31 114N 15W Goodhue 92 4 15 X 45 SW 1/4, SW 1/4 32 114N 15W Goodhue 92 4 15 X 46 NW 1/4, NW 1/4 5 113N 15W Goodhue 110 4 40 X 47 NW 1/4, NW 1/4 5 113N 15W Goodhue 105 4 26 X 48 NW 1/4, NW 1/4 5 113N 15W Goodhue 110 4 20 X 49 NW 1/4, NW 1/4 5 113N 15W Goodhue 101 4 20 X 50 SW 1/4, NW 1/4 5 113N 15W Goodhue 105 4 12 X 51 SW 1/4, NW 1/4 5 113N 15W Goodhue 104 4 15 X 52 NW 1/4, NW 1/4 5 113N 15W Goodhue 90 4 20 X 53 NW 1/4, NW 1/4 5 113N 15W Goodhue 92 4 20 X 54 NW 1/4, NW 1/4 5 113N 15W Goodhue 100 4 20 X

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 74 of 80

TABLE 2.4-3 Page 4 of 4

WELLS IN PLANT VICINITY

Location Use Well Fractional Sec Twp Range County Depth Diam Demand Domestic Livestock Irrigation Other No. Section (ft) (in) (gpm) of acres 55 NW 1/4, NW 1/4 5 113N 15W Goodhue 84 4 15 x 56 NW 1/4, NW 1/4 5 113N 15W Goodhue 80 4 20 x 57 SW 1/4, NW 1/4 5 113N 15W Goodhue 86 4 15 x 58 NW 1/4, NW 1/4 5 113N 15W Goodhue 94 4 15 x

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 75 of 80

TABLE 2.5-1 GEOLOGIC FORMATIONS IN THE GENERAL AREA OF THE SITE

GEOLOGIC AGE GEOLOGIC APPROX. THICKNESS DESCRIPTION REMARKS ERA PERIOD NAME IN FEET

Cenozoic Recent Unconsolidated clay, Largely Mississippi and Vermillion Quarternary Deposits silt, sand and gravel River deposits

Pleistocene 20 to 200 Unconsolidated clay, silt, sand, Largely from Superior and Des gravel and boulders deposited as Moines lobes of Wisconsin glaciation till, outwash and loess

Paleozoic Oneota 100 Dolomite Exposte along river bluffs Ordovician

Cambrian Jordan 100 Sandstone An important aquifer

Saint Lawrence Formation 43 Dolomite siltstone and silty dolomite

Franconia Formation 180 Sandstone and shale Aquifer zones. Uppermost bedrock (St. Croix Series) at site

Dresbach Formation 100+ Sandstone, siltstone and shale Aquifer zones (St. Croix Series)

Precambrian Hinckley Formation 100+ Sandstone An important aquifer Keweenawan

Red Clastic Series Sandstone and Red Shale May not be present under the site

Volcanics Mafic lava flow with thin May be present under the site layers of tuff and breccia

Granite and Associated Principal Basement rock under Intrusives the site

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 76 of 80

TABLE 2.6-1 MINNESOTA EARTHQUAKES

YEAR DAY TIME INTENSITY LOCALITY EPICENTER AREA LOCATION SQ.

N. LAT. W. LONG MILES

1860 V + Central - -

Minnesota

1865-70 ? Le Sueur, - -

Minnesota

1909 5-26 08:42 VIII Dixon, 42.5 89.0 500,000 III in Minn. Illinois

1917 9-3 15:30 V-VI Staples, 46.3 94.5 10,000 Minnesota

1928 12-23 00:10 III Bowstring, 47.4 94.0 Local Minnesota

1935 11-1 01:04 VI Timiskaming, 46.8 79.1 1,000,000 I in Min. Canada

1938 10-11 03:37 V Sioux Falls, 43.3 96.4 3,000 IV in Minn. S.D.

1939 1-28 11:55 IV Detroit Lakes, 46.9 95.5 2,000 Minnesota

1950 2-15 04:05 V-VI Alexandria, 45.7 94.8 Local Minnesota

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 77 of 80

TABLE 2.6-2 MODIFIED MERCALLI INTENSITY SCALE OF 1931 (Abridged)

Page 1 of 2

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 card 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 indoors. 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 or badly designed structures; some chimneys broken. Noticed by persons driving motor cars.

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 78 of 80

TABLE 2.6-2 MODIFIED MERCALLI INTENSITY SCALE OF 1931 (Abridged)

Page 2 of 2

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 foundation. 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.

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 79 of 80

TABLE 2.9-1 CONTROL ROOM HABITABILITY TOXIC CHEMICALS Page 1 of 2

CHEMICAL Toxic Chemicals Stored Onsite Toxic Chemicals Shipped by Rail (SOO Line, subsidiary of CPR):

1. Boric Acid 1. Chlorine

2. Diesel Fuel #1 2. Ammonia Anhydrous

3. Diesel Fuel #2 3. Isobutane

4. Nitrogen (Liquid) (Note 3) 4. LPB

5. Oil, Diesel Lube 5. Styrene, Monomer

6. Oil, Turbine Lube 6. Vinyl Acetate

7. Hydrazine 7. Benzene

8. Sodium Hydroxide (50%) 8. Denatured Alcohol

9. Sulfuric Acid 9. Ethyl Alcohol

10. Ethylene Glycol 10. Ethyl Acetate

11. Anion/Cation Resin 11. Methanol

12. Carbon Dioxide 12. Toluene

13. Propane 13. Flammable Liquid, N.D.S., (Pulp Mill Liquid)

14. Hydrogen (Note 4) 14. Petroleum Naptha

15. Natural Gas 15. Ammonium Nitrate Fertilizer

16. Sodium Hypochlorite (12%) 16. Hydrogen Peroxide

17. Ammonium Sulfate (20%) 17. Phenol

18. Sodium Bisulfite (40%) 18. Phosphoric Acid

19. Benzene Phosphorous Dichloride Toxic Chemicals Stored Within Five Miles of Plant: 20. Molten Sulfur Ammonia potentially stored on a farm near the station 21. Nickel Sulfate (Note 1)

Toxic Chemicals Shipped by Truck: 22. Hexene None (Note 1) 23. Hydrochloric Acid

PRAIRIE ISLAND UPDATED SAFETY ANALYSIS REPORT USAR SECTION 02 Revision 38 Page 80 of 80

TABLE 2.9-1 CONTROL ROOM HABITABILITY TOXIC CHEMICALS Page 2 of 2

CHEMICAL Toxic Chemicals Shipped by Rail (BNSF Line):

1. Chlorine 38. Ethanolamine

2. Sulfur Dioxide 39. Hexane

3. Carbon Dioxide 40. Nitric Acid

4. Hydrogen Sulfide 41. Propane

5. Butane 42. Propylene Oxide

6. LPG 43. Hydrochloric Acid

7. Vinyl Chloride

8. Ethylene Oxide

9. Styrene Monomer

10. Benzene

11. Denatured Alcohol Toxic Chemicals Shipped by Barge:

12. Ethyl Alcohol 1. Chemical Fertilizers

13. Methyl Alcohol 2. Petroleum Pitches

14. Paint 3. Petroleum Naptha

15. Resin Solution 4. Petroleum Solvents

16. Aromatic Concentrates

17. Diesel Fuel Oil Toxic Chemicals Shipped by Canadian Pacific Railway line (CPR Line):

18. Petroleum Naptha 1. Acetic Acid

19. Calcium Carbide (Flammable Solid) 2. Hexane

20. Sodium Metal (Flammable Solid) 3. Propane

21. Sodium Chlorate 4. Hydrochloric Acid

22. Chloropierin Mixture 5. Butadienes

23. Sodium Cyanide (Solid) 6. Octane

24. Sulfuric Acid 7. Picolines

25. Phosphoric Acid 8. Acetonitrile

26. Acetic Anhydride 9. Fluorosilicic Acid

27. Ferric Chloride Solution 10. Isopropanol

28. Silicon Chloride 11. Toluene

29. Titanium Tetrachloride 12. Acetone

30. Potassium Hydroxide 13. Carbon Dioxide

31. Sodium Hydroxide 14. Gasoline

32. Molten Sulfur 15. Ammonia

33. Butadiene

34. Carbon Disulfide Note 1: See Reference 23 for details.

35. Coal Tar Distillates Note 2: Not used.

36. Propylene Note 3: See Reference 31 for details.

37. Acetic Acid Note 4: See Reference 33 for details.

1 2 3 4 5 6 7 8 9 10 11 12

REVISIONS AD AS BUILT-ADDED GUIDE WALL &

FLOW CUTOFFS TO A s s s s s s s s s SCREENHOUSE A s s s s s s s s s INTAKE CANAL.

s ITT ~ ITT.;.; ~ ITT s ITT s PER ORR PI-97-lt7 ITT ITT ITT ITT ITT ITT o5 o5 er I

'" '" ITT ITT

" " M M iq I OWN= WHS 9-3-97 N N N N N N o/ o/ N, CHK'D: PAS 11-6-97 597,000 "' "' "' "' "' "' 597,000 MOD*: 96CW01 FILMED U-97 a - ii. 2045' 76 AS BUILT I[ 20' GATE ADD HOLDING POND Ii AND ACCESS ROAD HURD STA. # 2 E':\\CLU5,0W l='E.NCE.

N.-l:1961B09.152 I E. 2,349,41 !5.15 ' PER ORR PI-09-032

/ OWN1 KJF 10-6-09 rl-- - - CHK'D: JL 10-14-09

MO *: EC-13321 596,500 APP'D: CMR 10-14-09 I ' REVISED TO REFLECT 77 AS BUILT I STURGEON LAKE i I REMOVAL OF FAB SHOP B '.,..-- - SHORE LINE Si CREWS QUARTERS B

LEASED BY N.S.P. Co. FROM PER ORR PI-11-141 GBB \\ THE DEPT. OF THE ARMY AS DESCRIBED IN ARMY LEASE DWN1 KJF 9-23-11 No, DACW22-1-76-l86 CHK'D: GTL 9-2"1-11 688 MOD": EC-16742 APP'D: CMR 10-3-11 596,000 ------~-~-692 596,000 78 AS BUILT-

---~------t--------- - REVISED TO REFLECT THE AREA L TG POLE REMOVAL OF RAIL ROAD

!TYPJ I TRACKS *2 & *3 WITHIN THE OCA & PA.

I PER ORR PI-11-196 I OWN: KJF 10-13-11 CHK'D: GTL 10-20-11 MOD", EC-17204 APP' : CMR 10-20-11 I I w 79 AS BUILT-595,500 I \\ 595,500 REVISED TO ADO THE SAF C (SECURITY ACCESS FACILITY C I & EXPANDED PROTECTED I \\ << AREA FENCING & BARRIERS I I, PER ORR PI-12-099 OWN: KJF 1-3-12 I CHK'D, JCL 5-11-12 I i MOD*: EC-15219 I I APP'01 CMR 5-14-12 I I 80 AS BUILT-ADDED NEW DISTRIBUTl N CENTER.

595,000 595,000

HURD STA :Ir 2 PER ORR Pl-12-236 N. 5516,809.52 OWN: JEK 12-13-12

/ E. 2,349,415.15 CHK'D: PWM 2-8-13 MOD": EC-19055 of *, APP' : CMR 2-8-13 I',: 81 AS BUILT-D '* ADDED RSG STORAGE BLOG, D PARKING & LAYDDWN AREAS AND TREATMENT BASJNS FOR U2 SGRP PROJECT.

594,500 PER ORR Pl-13-266

OWN1 KJF 1-10-14 N CHK'D: JLS 1-24-14 MO *: EC-21639 an APP'01 CMR J-29-14

I 82 AS BUILT-E-W 4 LINE--, REMOVEO GRAVEL PARKING 0 LOT EXTENSION THAT WAS "

INSTALLED FOR U2 SGRP. 0 0

PER ORR Pl-15-012 594,000 594,000 OWN1 JEK 1-29-15 0 CHK'D: JLS 2-9-15 0 MOD": EC-23354 APP' : CMR 2-9-15 0 83 AS BUILT- ~

E ADDED FLEX STORAGE E BUILDING AS SHOWN. 0 co PER ORR Pl-16-019 OWN: LAB 1-25-16 CHK'D: TJP 1-26-16 MOD": EC-23565 APP' : KJW 1-26-16

'1 84 AS BUILT-i ADDEO NATURAL GAS I SUPPLY LINE TO SAB.

I I PER ORR Pl-15-219 I OWN: JEK 1-5-16 I CHK'D1 TLL 3-3-16 I MOD*: EC-23319

\\ 593,000 APP'O: KJW 3-9-16 F \\ \\ 85 AS BUILT-F ADDED RAO STORAGE AREA I 19 NORTH OF ASG STORAGE

\\, BLOG & SCALE SAB.

0 \\ PER ORR PI-16-200 OWN: JEK 9-20-16

\\ CHK'O: MP 9-20-16 MOO": EC-27185 APP' : OB 9-20-16 592,500 592,500 86 AS BUILT-UPDATED NW CORNER OF PA PER SECURITY UPGRADE, INCORPORATE FCR 501000001465-052.

PER ORR Pl-20-075 OWN; JEK 12-1-20

~----------~ CHK'O: TPB 12-1-20 I NOTES1 692 MOD*, 601000001455 REF UST OF DWGS - NFh6204-8 DISCHARGE APP'D: OB 12-2-20 STRUCTURE ~-------,(")

G YARD PLAN DWGS - NF*3f204-l THRU -10 -sss-j --- ISl SHE PLAN - NF-116972 N 592,000 592,000 CD

'LEGEND \\ (")

NAME OF SYSTEM SYMBOL J N.S.P. Co. PROPERTY LINE z SHORE LINE ROAO DESIGN HIGH WATER ELEVATION 703'--6"

---

;,---- NORMAL WATER ELEVATION 674'--6" RAILROAD TRACK *> LON WATER ELEVATION 672'--6" SECURITY FENCE ~- ____J__:'L ELEVATIONS SHOVvN ARE MEAN SEA LEVEL SUB-STA. FENCE -~___,.._,._ DATUM 1929 ADJUSTMENTS TO CORRECT EXCLUSION FENCE TO 1912 DATUM ADD 0.48 FEET.

591,500 NATURAL GAS SUPPLY LINE

H PROPERTY PLOT PLAN H

100 0 100 200 WQFEET SCALE IN FEET NORlHERN () _,,,_,_ STATES POWEFl COMPANY st.ALE 1"=200' REV 86

PRAIRIE ISLAND NUCLEAR GENERATING PLANT NF-38203 AEDWl~,M~ESOTA

$$$$$$SYT IME$$$$$$$$$$$SYDA TE$$$$$$ $$USERNAt.E$$ NF-38203.0G~j NSP GE:lfERATION CNJ j 1 2 3 4 5 6 7 8 9 10 $$$$$$$$$0ES I GNF IL$$$$$$$$$ 12

FIGURE 2.2-1 REV. 37

CAD FILE: U0220LDGN REVISIONS

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011111,u, U02202.0GN NCRTIERN ST,.TES POWER COMPANY SCM.£ NONE PRAIRIE ISLAND NUCLEAR GENERATING PLANT FIGURE 2.2a2 REV. 18 RED WING MINNESOTA OAK GROVE REVISIONS ti---,

-i 440 th AVE

~ 430 th AVE 430 ii> AVE HASTINGS

320 1h AVE

230 1h ll'IE

0 1 2 MILES

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80 AVERAGE 'f' u.

0 60 N Cf) EXTREME MINIMUM (OBSERVED) N w """

w 40 0 0

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BASED ON DATA FROM MINNEAPOLIS

-20 'f' 1931 - 1960 1960 - 1969

-40 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

MONTH

Maximum Observed Temperature = 99° F Minimum Observed Temperature = -32° F

CLIMATE OF PRAIRIE ISLAND SITE REGION

DWN: LAB DATE: 7-11-19 NORTHERN STATES POWER COMPANY SCALE: NONE fl Xcel Energy-..,_ ____...._ ____ __

CHECKED: CAD U02301A.DGN PRAIRIE ISLAND NUCLEAR GENERATING PLANT FIGURE 2.3-1A REV. 36 FILE: RED WING, MINNESOTA 8.-----------------------.-----T--.....------,.-----.

RAINFALL 24 HOUR MAXIMUM

6

V)

LI.I 5 4 z

2 AVERAGE MONTHLY

ALL RAINFALL CURVES BASED

• OBSERVED ON DATA FROM 1939-1969 JULY 1892 0.__ _ __._ _ __.I,_ _ _,__ _ __._ __..._ _ __.__ _ ____, __ _._ _ __._ __..._ _ __,

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC MONTH

CLIMATE OF PRAIRIE ISLAND SITE REGION

OWN T. MILLER DATE 6_23-99 NORTI£RH STATES POWER Cot.FAHY SCALE& NCI£ ILE 0023018.DGN FIGURE 2.3-1 B REV. 18 PRAIRIE ISLAND NUCLEAR GENERA TING PLANT IIED lltG IIIKSOTA 90 fir----,.------.------------------

EXTREME WINDS

PROBABILITY OF WIND

z: SPEED MORE THAN uxu Q.

~ 70 I

C I.LI I.LI Q.

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C z

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• WINDS BASED ON 31 YEARS OF DATA DURING PERIOD 1938-1969

30

.01.02.os o. 1 0.2 o.s PROBABILITY/ YR

CLIMATE OF PRAIRIE ISLAND SITE REGION

OWN T. HILLER DATE 6-23-99 NORTHERN STATES POWER COMPANY SCALE: NONE CHECKED CACI PRAIRIE ISLAND NUCLEAR GENERATING PLANT FILE U0230lc.oGN IEI INl MN£SQTA FIGURE 2.3-1 C REV. 18

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DWN T.HILLER DATE 6-23-99 NORTI£RN STATES POWER COMPANY SCALE: NO£ Ct£CKEO CAO PRAIRIE ISLAND NUCLEAR GENERA TING PLANT FIGURE 2.4-1 REV. 18 FILE U02 401.0GN IIED WIG IIHNESOT A 1,000,000 9 8

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% TIME

GRAPH COMPILED FROM DATA OBTAINED FROM U.S. GEOLOGICAL SURVEY STATISTICAL SUMMARIES

FLOW DURATION CURVES FOR MISSISSIPPI RIVER

OWN T. MILLER DATE 6-23-99 NORTHERN STATES POWER C()li,f)ANY SCALE: NONE I OECKED l..AU FIGURE 2.4-2 REV. 18 PRAIRIE ISLAND NUCLEAR GENERA TING PLANT FILE U02402.DGN RED RC WNEiOTA REVISIONS

DAM 4 ROLLER GATES UPSTREAM - CURRENT____.. DOWNSTREAM

-CURRENT~ (90' I 20')

C

685 5

SLOPE-I ON 3 SLOPE-I ON 5 5

SECTION A-A EARTH DIKE CTYP)

PLAN VIEW

DOWNSTREAM

EL 704 EL 672 5

UPSTREAM EL 680 5 111111 NORMAL LP EL 666 5 UP!>TREAM DOWNSTREAM -CURRENT-LP DAM tt4 EL 654 5 EL 659 5 CURRENT NORMAL U P EL 674 5~

-=-

SECTION C-C SECTION 8-8 ROLLER GATE MAIN LOCK

0111 TAM °"TE 6-23-99 SIGNIFICANT NO,

OEmll GAOUP 5 CL 6

-.ie:TIIL ETNSUR LOCK AND DAM N0.3 PLAN AND SECTIONS

CM '11..£, II0240MlOII NORTHERN STATES POWER COMPANY.,_ICIU __ NON_E _ __. ______ -t PRAIRIE ISLAND NUCLEAR GENERATING PLANT FIGURE 2.4-3 REV. 18 RED WING MNESOT'-

t-l&J X 70 z

l&J a:

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IA.I "

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30---------------------------JAN FEB MAR APR MAY JUN JUL AUG SEP OCT W:N DEC

MONTH

PERIOD OF RECORD 1956 TO 1964

REFERENCE:

UNPUBLISHED DATA ON STREAM TEMPERATURES FOR THE MISSISSIPPI RIVER COMPILED BY THE U. S. ARMY CORPS

• OF ENO PAUL MINNESCYrA INEERS, ST.

AVERAGE TEMPERATURE OF MISSISSIPPI RIVER AT ST. PAUL, MN.

OWN T, MILLER DATE 6-23-99 NORTHERN STATES POWER COMPANY SCALE: NONE CHECl<ED CAO PRAIRIE ISLAND NUCLEAR GENERATING PLANT FILE U02-4D-4,DGN FIGURE 2.4-4 REV. 18 RED WNG MNESOTA REVISIONS N N C/)

0 0 -w LL 1-% 0 0 *

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u u...J C/)- 0:: - % u u 0 0 *,c Q.. C ~ 0 0

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...... PROFILE PUIIT ' I

... _ - -. ~- - - --- -... s11E,

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1-- - 1952 HIGH A - - ---.. --

LLI -- - - WATER LLI - - -- ~- - i- - - - -,.._ - -

LL z

z 0 680 -

LLI

...J LLI POOL ELEVATION UPSTR~fRO~ LOCK AND DAM NO. 3 674 -6 670

1934 LOW WATER

660 NOTE:

ENGINEERS STREAM PROFILE CURVES MODIFIED FROM U.S. CORPS OF

DIii TAM DIITES-23-99 SIGH!FlCANf NC.

CHEIDD z

~PIIOJECT __..,, __ ET_Ns_u_R -....... STREAM PROFILE FOR MISSISSIPPI RIVER FROM

-* CEIT.

LOCK AND DAM NO. 2 TO LOCK AND DAM NO.3

CillO FII..E,UD2401UXlN INCLUDING SITE OF NUCLEAR PLANT NORTHERN STATES POWER COMPANY IOU NONE IIEY PRAIRIE ISLAND NUCLEAR GENERA TING PLANT FIGURE 2.4-5 REV.18 RED WING ~SOTA

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LOCATION PLAN OF WELLS IN PLANT VICINITY

OWN T,MILLER DATE 6-23-99 NORTHERN STATES POWER COMPANY SCALE: NONE C1£Cl<ED CAD U02-40&.DGH PRAIRIE ISLAND NUCLEAR GENERA TING PLANT FIGURE 2.4-8 REV. 18 RED WINO WIESOTA 2 3 4 5 6 7 8 9 10 11 12

REVISIONS

A 1111S BUILT*

ltCORPOIUIT[ DRAWING INTO NSP DIIAWllrlO SYSTEM A SEE OWG.N'"-38276*11 2 PER NIR Pl*"IIM82 A FCII SPLASH Gl#IRO DETAILS DVN, IIMS 12*7-qa AT FLOOD PANELS 1<<*1 CHIC'O.PASl2*2:l*"8 1<<*4 l MK*5 -~ FR.MED l*'t'I

Rolhng Do.,.. B

AOOEDSECTIDI\\ID*DI, G)---- - - MODIFIED OOOR..... RS.

CHAICiEODIIG.CLASS HIOHW.TER FROti43TOI.

EL. 713'*1" DWN,TIIM 111!1-12*82 CIIC1JI""' lr.!-13*12 PAOJ*,IIBMl.2 IEV'D,c.D.KI.R.El!l-13*12

• ~ *; *: :1_***_: __ -.*1*..- APP'O&CERT1

• .* PERDRRPl-ll2*17'1

OWNiiJES fi*83*112 CIIC'DICtiAB*6*12 ICJD*18lBMll2 FILMED 6182 B 0--- C AS BUILT* B ADDED REF.DWG.ILI-IBER FORMOO!Flc.lTIOMTO FLOODP#INELS

PERIRIPl-ll3*113

@---- DWN,GPL7-14*13 CIIC'DI CNI 8/13113 MOD*11J.-Z SCREENHOUSE FILMED 8/13 76 AS BUILT*

REMOVE DOOR JU,4BERS (0------ -421.-4231437.

l'ERCIIRPl-13-143 DWN,JEI( 3*4*13 SECTION B-8 CHK'O.ICAK 3*7-13 MDD*1EC*21614 0 I IYPICALFLOOOPANEL Al PASSAGE DOOR APP'DICMR 3*7*13 C C SECTION A-A I 'IPICOI riood p.... 1

.,.. 011,ng do....

' SECONDARY I ADM! N BLDG

=====~ i;,

EL. 711!1'*r :

~

D ~t~~!~~- D I ~ JI CD CD TURBINE BUI LOI NG 0 0)

N I 'Iii' T""

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E E SERVI CE BUILDING - ----0

It---------<-- - -0 -c_J C7 AUX! LI ARY BUI LOI NG

SECTION C-C

-J-----------0 T'l'PICIIII. CIXRETE rDI.II0Al10NWAI.L

UNIT 2 -----------G REACTOR UNIT 1 F BUI LOI NG REACTOR F BUI LOI NG 0----------------- LEGEND

1. Jll(-1, 1<<*4, 1<<*5, &1<<*'1 ADLLIIGDOOAS SEEIMOS.N"-38276,. } FLOOD PIIINELS AT } FIJI MOOIFICATICIIS, llF*:!9276*1 a llF-38276*2 0------------------- ""

HIGH,11UER 2. 1<<*7, 1<<*11, TIIIU, MC-17,} F~~~~T } =~

EL. 793'*1' 12N FIJI *17

3. 301§ZJ1::, }FLOOD DOORS } rlJI MODIFICATIONS, SEE DWOS. N"*38271MI "76

4, IZZZZI } CIINCRET[ FLOOO WIIILL ISi G 5.- }coNCRETESTIU:TlllE ISi RAD WASTE ISi C'1 BUI LOI NG,....

........-FLOODDOIIA 0-- -- -- -- -- -- -- - -- -- ORUM STORAGE ENCLOSURE DESIGNHIGHWlilT[RELEYATIDN 713'*1" NOAIMLWITEAELEYAIION 674'*6" J LDWWITERELEYATIOII 172'*1" z

ELEVATll>>ISSHDWNARE1Mt&EALEYEL OATL.fill-.ZC,A0JUSTMENIST0CORRECT l01<n20ATUMMI0&48FEET.

CAAIJEEL.

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• t>:l""" ~ """"- " tit po'l=.,,. o' h l )o:1< YOJ1"""' ~ -,. il ~ br

"'*~ - -*- **~........ u,,-, *,~,. **~""""*

4111 112 s... I UN SECTION 0-D REF, DlffiS,

,.-.3a275 FLOOD PROTECTION H llF*383111*28 KEY PLAN ANO DETAILS H

NOHIHERNSTATESPOWERCOMPANY fl,Xl>>l&IBnff = 76 PRAIRIE ISLAND NUCLEAR GENERATING PLANT NF-173000

lf'*173111.0CiNCll!lE'IE!l'ill 2 3 4 5 6 7 8 9 10 12 FIGURE 2.4-7 REV. 33

CAD FILE: U02407.DGN HUdeon t ~ / 6ao...., ~ /

HASTINGS "-....

~ FAULT / //

'1/ ~

-.......,,,... '~I ;'/

~,,,"';

~ 'J

"-~/

It I

0po I

0po

LEGENl

0-fg - LIMESTONE AND DOLOYTE - PU TTVILLE Fm SHALE - GLENWOOD Fm Oap - SANDSTONE - ST.PETER Fm Opo - DOLOMITE - SHAKOPEE Fm SANDSTONE - NEW RICHMOtl> Fm DOLOMITE - Ot£0TA Fm LEGEND 6ao - SAN>STONE - JORDAN Fm FAULT - KNOWN AN> WERRED DOLOMTE AND SI. TSTONE - ST. LAWRENCE Fm ANTICLINE ACCESS SAN>STONE - FRANCOttA Fm.. DRESBACH Fm 5 0 5 ~ ~ ~ ta ~ CROSS SECTION A-A MILES

= = = = ======-=-===== -=-----========.. --- SYNCLIE AXIS

REGIONAL GEOLOGIC MAP OF BEDROCK FORMATIONS

OWN T. MILLER DATE 6-23-99 NORTHERN STATES POWER COMPANY SCALE* NONE CHECKED ?tt1E PRAIRIE ISLAND NUCLEAR GENERA TING PLANT FIQURE 2.5-1 REV. 18 002501,DGN RED WING IIN£SOTA HASTINGS F'AULT---4---

ZONE \\

TWIN CITIES BASIN "----

AFTON-HUDSON ANTICLINE

,_....___ ISLAND _...,£--- PRAIRIE SITE

---RED WING ANTICLINE

MIi.Ei IO O 10 to JO 40 50 to 10 10 10 100

REFERENCES

1. TECTONIC MAP OF THE UNITED STATES BY LEGEND USG SAND THE A~RICAN ASSOCIATION OF PETROLEUM GEOLOGISTS 1961 -- FAULT-KNOWN AND INTERFERRED

2. UNPUBLISHED STRUCTURE MAP BY MINNESOTA GEOLOGICAL SURVEY. + ANTICLINE AXIS

+SYNCLINE AXIS

REGIONAL GEOLOGIC STRUCTURE

OWN T. MILLER DATE 6-23-99 NORTHERN STATES POWER COMPANY SCALE* OONE C~Cl<ED CAO U02502.0GN FIOUAE 2.8-2 REV. 18 PRAIRIE ISLAND NUCLEAR GENERA TING PLANT IIED WIG lolNNESOTA nl C z

~ *

~, ;-I X

F r

v n 0 NW SE

~ > ; A A

C 0 a, PRAIRIE ISLAND N I UI N GENERATING 0 c., ~

w I UJ ST. PAUL HASTINGS SITE RED WING ~

b l8 C) UJ z I ::0 lL.

ITI z C) - i i t t ~

.,, 0 - z 700 AVERAGE BOTTOMLAND TERRACE ELEVATION ALONG THE MISSISSIPPI RIVER, 700 ~

0 z O ALLIJYIIM APPROXIMATELY 180 FT. OF SAND Z

ij l> ~ 5 oo- - - - - - - a-~-~- ORDOVICIAN - - - - - CAMBRIAN U- - --....:-500 ~

r > TWIN ~ DCLOMITE SANDSTONEE q RED Wit<<J........._ <e

-~ C)

"'::u r -t ITI ~ CITIES AFTON,,:JO~TE, ~~~E....,..._ ~

~ifi 0 Cj! r UJ BASIN ANTICLINE // ~I~ ~ '4~UP TYHlV,*.,,,, rrl

~ z u, 0 C: -I C) t,o f1*,_. RED Wit<<J I n - i -~~ ~.,,-- _,,/" FAULT r -t n ---..._...._ I~~__,,,,.

I\\:'~ :::0.,, n 0 ::0 -- --- --./1.Jl;. -- /

~ ~ !3 0 c;,* -- -- I I..,,,,.. ---~ __,,.. PRECAMBRIAN

IT1 (I) :;on (I) SANDSTotE i -- ---.__ - -- MINOR SHALi;-.

-t.,, (I) UP TO 4400 Fr. --

Zz ITI ---- THICK_,,-, ---

c;') -< n "lJ -t,,,,,

r -

0 z _,_-- PRECAMBRIAN

-t z TREN> CF THIS CONTACT lMKN>WN -- --- MAFRIC EXTRUSIVES, l> I UP TO 20.000 u,* l> FT. THICK

'Tl n l> -- ------ -- -

s r -

C '!:'

u ~

rn ~

01 I HORIZONTAL SCAI Ea 1 IN. = APPROX. 6 MILES Ci) VERTICAL SCALE VARIABLE AND HIGtL Y EXAGGERATED

u

~

CD V,

~ BORING 3 u ~ SURFACE ELEVATION 6783 SHEARING STRENGTH IN LBS..SQ.FT. ~ 0..

6000 5000 4000 JOOO 2000 1000 0 9 J cc SYMBOLS DESCRIPTIONS 680 DARK BROWN FINE SANO WITH SILT TO~SOIL ROOTS TO A INCHES BWWN FINE SANO 670 -\\ WATER LEVEL 6-5---07 219% 96

660 218% 107 BROWN FINE TO MEDIUM SAND WITH GRAVEL AND OCCASIONAL COBBLES 650 BROWN FINE SAND WITH OCCASIONAL GRAVEL

• AND OCCASIONAL COBBLES

640 212% 105

630 BROWN FINE TO MEDIUM SAND WITH GRAVEL 620 1111"11'1 I BROWN FINE TO COARSE SAND WITH GRAVEL 101% m 610 22 l.nul.ml I BROWN FINE TO MEDIUM SAND

tu 209% 105 w

,.._ 18-

~ 600 GRADING SOME GRAVEL z 141% 121 BROWN FINE TO COARSE SAND WITH SOME 0 48 *:: :: GRAVEL AND ZONES OF HIGH GRAVEL CONTENT

~ 590 * :/. :... **

~...

w 189% 111 78 **J_:1 SW 580.*

99% 129..

570 fflll!Tmit---i BROWN FINE TO MEDIUM SAND 226% 102 !l!l'HW SP

• 1 BROWN FINE TO COARSE SAND WITH GRAVEL 560 SW 119% 130, -~- BROWN FINE TO COARSE SAND AND GRAVEL

!U~, SP AND SOME COBBLES

........ GP 550 102% 127 ~11111---1 BROWN FINE TO MEDIUM SAND

540 196% 109 0ROWN MEDIUM SAND WITH SOME GRAVEL OCCASIONAL LAYERS OF COARSE SAND 530 200% 106 AND GRAVEL lill111 IWI I U!!ti~ BROWN FINE TO COARSE SAND GRAVEL AND BOULDERS 520 m I BROWNISH GRAY FINE GRAINED SANDSTONE "T" WITH THIN SEAMS OF DARK GRAY SHALE (MEDIUM HARD) 55% THIN BEDDED AND HORIZONTALLY BEDDED 510 PARTIALLY CEMENTED GRADING MEDIUM GRAINED 30% SHALE SEAMS GRADING OUT GRADING TO LOOSELY CEMENTED 500 IM'IMI I GRADING MORE CEMENTED GRADING TO LOOSELY CEMENTED

490

~ ~ 1~ 1 BORING COMPLETED AT 178.5 FEET

~ 1 I! ON 5-24-67

~ ~ ~ CASING USED TO A DEPTH OF 28.3 FEET

~ I PIEZOMETER INSTALLED AT 10 FEET

~ z § 2 ~ ON 5-24-67 m 0 NOTES:

vi i "' c::... I i ~ "' "' I

-0 0.,,

~ z ~ GROUND SURFACE ELEVATIONS REFER TO MEAN SEA

! ~ 51 LEVEL DATUM - 1929 ADJUSTMENT.

INDICATES A DAMES AND MOORE UNDISTURBED

~ ~ ~ "' SAMPLE. (TYPE U SAMPLER)

! G)"' !

~ m ()

~ Z 0 ~ ~ INDICATES STANDARD PENETRATION TEST. FIGURES

..., m ~ UNDER THE BLOW COUNT COLUMN INDICATE THE

> ~ -v

j i ~ NUMBER OF BLOWS REQUIRED TO DRIVE A SAMPLER, z WITH AN OUTSIDE DIAMETER OF 2 INCHES, ONE Q FOOT WITH A 140 POUND WEIGHT FALLING 30 INCHES.

z I r-100% I INDICATES DEPTH. LENGTH. AND PERCENT OF CORE

--i 0 RUN RECOVERED.

G) INDICATES SAMPLE SUBJECTED TO DYNAMIC TRIAXIAL 0

• COMPRESSION TEST. DATA REGARDING TEST IS

,, ~ -n LOCATED IN PART 6 OF REPORT.

i5 CD INDICATES SAMPLE SUBJECTED TO DYNAMIC CONFINED C: 0 z 2!:! *

• COMPRESSION TEST. DATA REGARDING TEST IS LOCATED lJ 0 IN PART 6 OF REPORT.

m ~ z G)

N (/'I en I

~

• (/'I lJ I I... 6 z

(/1

~

a, BOWSTRING lII 1928

~ DETROIT LAKES y lX 1939 OUUJTH

STAPLE$

~-(1917

LONG PRAIR~'lZ'+ 1860 ALEXANDR!~ *

'lZ'-'iI 19!50y

I MINNESOTA

,-*-*-*-*-* l~A **-*-*-*-*--*- *------ ---*-.. -.

I *1 r EARTHQUAKE EVENTS IN MINNESOTA I

• 0 100 MILES lllll!!l--m!!!!!!!!l!!tll!l!!l!!!!!!!!!!!91!!!!!!!1!!!!!!!!a.. LEGEND I

~ LOCATION OF EPICENTER

REFERENCE:

1939 DATE OF EARTHQUAKE

EARTHQIJAkE lfSTORY OF TI£ LHTED STATES -n INTENSITY OF EARTHQUAKE PARTb STRONGER EARTHQUAKES OF 1l£ UNITED STA TES U. S. COAST AN> GEODETK:

SURVEY PUBUCA TION NO. '4H EARTHQUAKE EVENTS IN MINNESOTA

OWN T. MILLER DATE 6-23-99 NORTHERN STATES POWER COMPANY SCALE* NONE OECl<ED CAO U02601.0GN PRAIRIE ISLAND NUCLEAR GENERA TING PLANT FIGURE 2.8-1 REV. 18 IED IHI MNIESOTA