ML19281A048

Revision 27 to Updated Final Safety Analysis Report, Chapter 2.0, Site, Sections 1 Thru 9

ML19281A048
Person / Time
Site:	Peach Bottom
Issue date:	04/08/2019
From:	Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
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ML19281A037	List: ML19281A043 ML19281A045 ML19281A046 ML19281A047 ML19281A048 ML19281A049 ML19281A050 ML19281A051 ML19281A052 ML19281A053
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PBAPS UFSAR SECTION 2.0 SITE 2.1

SUMMARY

DESCRIPTION This section provides information on the site and environs of the Peach Bottom Atomic Power Station, summarizes the analyses and studies which have been conducted pertinent to the site, and sets forth the conclusions which may be drawn there from to confirm the suitability of the site for Units 2 and 3. Information is included which has been used in establishing safety-related portions of the plant design basis and in analyzing the safety of the station under normal and abnormal conditions. A summary of the station design bases which require special consideration of the site characteristics is contained in paragraph 1.6.1.1.10.

Information provided in this section was prepared by various groups within the licensees organization, as well as consultants retained by the licensee and Bechtel Corporation, including: Dr.

D. W. Pritchard - The Johns Hopkins University (hydrology); Dames and Moore (seismology - geology); Meteorological Evaluation Services, Inc. (formerly Smith-Singer Meteorologists, Inc.)(meteorology); International Chemical and Nuclear Corporation (formerly Nuclear Science and Engineering Corporation); and Combustion Engineering, Inc. (environmental radiation monitoring).

Dr. G. W. Housner, consultant to Bechtel Corporation, has reviewed the seismology portion of this section. Professor D. U. Deere of the University of Illinois was retained as a consultant to comment on the stability of the slopes.

CHAPTER 02 2.1-1 REV. 21, APRIL 2007

PBAPS UFSAR 2.2 SITE DESCRIPTION 2.2.1 Location The PBAPS is located partly in Peach Bottom Township, York County, partly in Drumore Township, Lancaster County, and partly in Fulton Township, Lancaster County, in southeastern Pennsylvania, on the westerly shore of Conowingo Pond at the mouth of Rock Run Creek.

The plant is about 38 mi north-northeast of Baltimore, Maryland, and 63 mi west-southwest of Philadelphia, Pennsylvania. Conowingo Pond is formed by the backwater of Conowingo Dam on the Susquehanna River; the dam is located about 9 mi downstream from the Unit 2 reactor. Figures 2.2.1 through 2.2.4 are maps showing the site location with respect to the surrounding area. The nearest communities are Delta, Pennsylvania and Cardiff, Maryland approximately 4 mi southwest of the closest reactor (Unit 2).

2.2.2 Property Ownership The licensee owns the 620-acre property lying within the solid site boundary shown in Figure 2.2.5, except that the immediate area on which Units 2 and 3 stand is owned by the licensee, and PSEG Nuclear, LLC, as tenants in common. The adjoining area lying along the discharge canal in a downstream direction, described in Figure 2.2.5 by a dashed boundary, was owned by the Philadelphia Electric Power Company, a wholly-owned subsidiary of PECO, as part of the Federal Power Commission Project No. 405 (Conowingo). An application dated February 25, 1969, was filed with the Federal Power Commission to alter the Conowingo Project boundary so as to exclude from that project this 26-acre tract and a littoral strip of land about 7,000 ft in length (upstream of the 26-acre tract) which was subject to flowage rights in favor of the Conowingo Project. On October 13, 1970, the Commission issued an order approving the application.

The site boundary, as defined in Section 20.1003 of 10CFR Part 20, includes both the solid and dashed boundaries shown in Figure 2.2.5.

Although not a part of the Peach Bottom project, the remaining land along both sides of Conowingo Pond, from below Holtwood Dam to Conowingo Dam ranging up to 300 ft back from the waterline, is owned by Exelon Corporations subsidiaries.

CHAPTER 02 2.2-1 REV. 26, APRIL 2017

PBAPS UFSAR 2.2.3 Site Arrangement and Exclusion Area Two aerial photographs of the site and surrounding countryside, taken in 1959 prior to construction of Unit 1, the now decommissioned HTGR, are shown in Figures 2.2.6 and 2.2.7. The first view looks approximately toward the west and the second approximately toward the north-northeast. Figure 2.2.8 is an aerial view of the site taken in November 1965 showing Unit 1 after completion.

The arrangement of the major structures on site for all three units is shown in Figure 2.2.5 and Drawing C-1. Drawing C-2 is a plot plan of Units 2 and 3. Figures 2.2.11 (looking approximately northwest) and 2.2.12 (looking approximately east-southeast) are aerial photographs of the site during the later stages of construction of Unit 2.

The Unit 2 and Unit 3 reactors are located about 700 ft and 1,000 ft, respectively, upstream of the center of the Unit 1 containment building and about 300 ft back from the shore line of Conowingo Pond existing prior to construction, shown in Figure 2.2.5.

The minimum exclusion distance from the center of the reactor to the site boundary from either Unit 2 or Unit 3 is about 2,700 ft as shown in Figure 2.2.5. The minimum distance from the center of a reactor to the site boundary in a downstream direction is about 3,300 ft (from Unit 2) and in an inland direction about 3,100 ft (from Unit 2). The minimum distance across the pond from either the Unit 2 or Unit 3 reactor to the far shore of the pond (to the northeast) is 7,600 ft. The minimum distance from the stack to the site boundary is 2,350 ft. The exclusion area, as defined in Section 100.3 of 10CFR Part 100, includes the area within the minimum exclusion distance from the center of Unit 2 and Unit 3 reactors as shown in Figure 2.2.5.

The "controlled area," as defined in Section 20.1003 of 10 CFR Part 20, includes the land area inside both the heavy solid black line and heavy dotted black line shown in Figure 2.2.5.

The restricted area, as defined in Section 20.1003 of 10CFR Part 20, includes the area within 1) the Protected Area Boundary (PAB) for Unit 2 and Unit 3, 2) the main Stack and the associated Radiation Monitor Building, and 3) the enclosed area surrounding the Onsite Radwaste Storage Facility. Other restricted areas may be established on a temporary basis in accordance with station procedures.

CHAPTER 02 2.2-2 REV. 26, APRIL 2017

PBAPS UFSAR The restricted area for the Independent Spent Fuel Storage casks will be an appropriate barricaded area around the storage casks such that the limits of 10CFR 20 are met.

The meteorological conditions with respect to annual radioactive effluent releases from the plant stack and reactor building roof vents have been evaluated for all points on the site land boundary and along the waterline. Based on that evaluation it was determined that the point on the site boundary described in Appendix E, paragraph E.3.3.1, receives the maximum annual dose.

Therefore, for normal plant operation, the pond can be considered as an unrestricted area.

2.2.4 Topography A topographical description of the site and the surrounding area is shown in Figures 2.2.2 through 2.2.8 and Drawing C-1. The plant is located between Conowingo Pond and the foot of a low hill near the point at which Rock Run Creek discharges into the pond.

Within a 1-mi radius of the plant and on both sides of Conowingo Pond, steep sloping hills rise directly up to about 300 ft above plant grade with outcroppings of rock apparent at many locations.

Because of the relatively rough terrain, much of this area is desolate with wooded areas scattered throughout, although the more gentle sloping areas are cleared and cultivated. The rather hilly terrain persists to a distance of 12 to 15 mi from the site.

Thereafter, the land becomes low rolling hills. The population density becomes greater and more concentrated centers of population occur.

Elevation versus distance for 10 mi from the stack has been determined from U.S. Geological Survey maps for each of the sixteen 22.5-deg sectors shown in Figures 2.2.2 and 2.2.3. The highest elevation in any direction versus the approximate distance from the stack as well as the direction of each high elevation is listed in Table 2.2.1. These highest elevations, plotted versus distance in Figure 2.2.13, were used to calculate radiation doses from the stack. More extensive information was submitted in Enclosure B (dated September 30, 1976) to Information Requested in Enclosure 2 to letter from George Lear to E. G. Bauer dated February 17, 1976.

Plant grade between the turbine buildings and the pond is nominally Elevation 116.0 ft Conowingo Datum (C.D.) (Elevation 116.7 ft MSL).

Grade between the reactor building and the hill is Elevation 135.0 ft C.D. Normal elevation of Conowingo Pond is between 104 ft and CHAPTER 02 2.2-3 REV. 26, APRIL 2017

PBAPS UFSAR 109.25 ft C.D., but can vary down to Elevation 98.5 ft C.D. due to hydroelectric plant operation.

The minimum suction water elevation to maintain normal operation is 98.5 ft C.D. The minimum water level for safe plant shutdown is discussed in Section 2.4. The elevation of the cooling water intake invert at the screen structure is 84.0 ft C.D.

At the pump structure shown in Drawing C-1, the water intake invert is 79.83 ft C.D.

2.2.5 Site Access and Control Access routes to the PBAPS are shown in Figure 2.2.4. The site area can be reached from the southeast on Maryland Route 623, from the southwest on Maryland Route 165, and from the northwest on Pennsylvania Route 74. The main access to Units 2 and 3 is either from Pennsylvania 74 via Lay Road and Papermill Road or from Maryland 623 to Flintville Road and Lay Road. Lay Road is a bituminous all-weather road which enters the site near Conowingo Pond upstream of the units. The south substation is reached from Flintville Road via Atom Road a bituminous all-weather road which enters the site from the south.

With the exception of the stack, the circulating water cooling towers, and the intake and discharge structures, Units 2 and 3 are completely enclosed in a chain link fence as shown in Drawing C-2.

Entrance to the plant area is controlled 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day. Passage through the guardhouse is required to gain access to Units 2 and 3.

The Independent Spent Fuel Storage Installation is enclosed in its own protected area boundary by fences separate from the plant's protected area boundary. When access to the facility is not required, remotely monitored security features and routine patrols ensure the security of the facility.

A rail spur from the former Maryland and Pennsylvania Railroad was extended to the site from the west and has since been abandoned.

CHAPTER 02 2.2-4 REV. 26, APRIL 2017

PBAPS UFSAR 2.2.6 Land Use 2.2.6.1 On-Site Approximately 700 ft and 1,000 ft downstream from Units 2 and 3, respectively, and included in their exclusion area is Unit 1, as shown in Figures 2.2.5 and Drawing C-1. Unit 1 is now in a SAFSTOR status that allows it to be safely stored and subsequently decontaminated to levels that permit release of the facility for unrestricted use.

Two 500-kV transmission substations are located on the Peach Bottom site, as shown in Figure 2.2.5. Each substation occupies a plot approximately 750 ft by 1,000 ft. The north substation is about 2,000 ft northwest of Unit 3 and the south substation is about 1,600 ft south-southwest of Unit 2. The substations are of outdoor construction; consisting of the necessary circuit breakers, disconnect switches, transformers, and associated equipment for four 500-kV transmission lines, two 500-kV substation tie lines, two 500-kV generator tie lines, and three 220-kV lines. The substations are unattended, and are remotely controlled from the control room of Units 2 and 3 and the Phila. main office. In addition, an existing 220-kV transmission substation is located adjacent to and upstream of Unit 1.

The two 500-kV substations are physically separated from both nuclear facilities and are enclosed each in separate fenced areas.

The two 220-kV substations are located at the north substation (with one of the two 500-kV subs) and south of the switchgear building behind the emergency diesel building.

There are no public highways which pass through the site, and no major arterial highways pass near the site. There are no items listed in the National Register of Historical Places within or near the site boundary. The nearest such place is the Fulton House (birthplace of Robert Fulton) on US 222, about 6.6 mi east-northeast of Unit 3.

2.2.6.2 Off-Site This section of the UFSAR describes the characteristics of the area surrounding PBAPS at the time of original construction unless otherwise noted.

The major portion of the land in the five-county area surrounding the site is used for agricultural purposes. In 1964, the portion CHAPTER 02 2.2-5 REV. 26, APRIL 2017

PBAPS UFSAR of each county's land used as farmland was: 55 percent in Chester County, Pennsylvania; 77 percent in Lancaster County, Pennsylvania; 66 percent in York County, Pennsylvania; 57 percent in Cecil County, Maryland; and 53 percent in Harford County, Maryland.

Pertinent agricultural statistics for each county are presented in Tables 2.2.2, 2.2.3, and 2.2.4.

Industrialization in the five counties surrounding the site is quite diversified and is becoming increasingly important. There are only a few industries within a 5- to 10-mi radius of the station, but most of them are associated with food processing, textiles, or tobacco. Pertinent industrial employment statistics for the five-county area are given in Table 2.2.5. In 1967, according to the Department of Commerce, the portion of each county's labor force employed in manufacturing was: 50 percent in Chester County, Pennsylvania; 54 percent in Lancaster County, Pennsylvania; 57 percent in York County, Pennsylvania; 48 percent in Cecil County, Maryland; and 35 percent in Harford County, Maryland. The employment in various types of manufacturing for each of the five counties and for the total five-county area is shown in Tables 2.2.6 through 2.2.11. In addition, Table 2.2.12 lists the products of and employment by the industrial companies located within a 10-mi radius of the site. None of these activities would adversely affect operations at the site.

A number of government installations are located in the five-county area. Cecil County, Maryland contains the Veterans' Administration Hospital at Perryville and a unit of the Army Engineers Corps along the Chesapeake and Delaware Canal. Harford County, Maryland is the site of the Aberdeen Proving Grounds, approximately 20 mi almost directly south of the site. Chester County, Pennsylvania contains the Veterans' Administration Hospital near Coatesville.

The use of land in a 19-county area, extending approximately 50 mi from the site, has been evaluated. The counties in this area are listed in Table 2.2.13.

As the distance from the Peach Bottom site increases, agricultural activities become less important, as evidenced by the drop in the percentage of those employed in agriculture services from 0.48 percent in the five-county area surrounding the site (Table 2.2.5) to 0.24 percent in the counties lying within approximately 50 mi of Peach Bottom (Table 2.2.14). Data in the latter table also indicate that the relative employment in other segments of business is not substantially different from those nearer the site.

CHAPTER 02 2.2-6 REV. 26, APRIL 2017

PBAPS UFSAR Employment by type of product manufactured in the 19-county area is shown in Table 2.2.15.

The area adjacent to the plant site, included in an arc with a radius of 7,600 ft or more, extending from northwest to east to southwest, is covered by Conowingo Pond. The pond is used for recreation and small boats may occasionally be in this area, especially during the summer season.

Within 10 statute mi of the PBAPS site are four aerodromes with only emergency facilities or no facilities according to the Washington Sectional Aeronautical Chart, 29th Edition, effective March 20, 1981, which is published in accordance with Inter-agency Air Cartographic Committee specifications and agreements and approved by the Department of Defense, Federal Aviation Administration, and the Department of Commerce. Tanglewood, Conowingo, Ruff, and Delta Aerodromes are listed in Table 2.2.15.1; Tanglewood and Conowingo are for public use. These aerodromes have no traffic areas. There are no civil or military aerodromes within 10 mi of the site.

The center lines of Victor 3 Airway and Victor 93E Airway are within 1 mi of the PBAPS site. Victor airways extend 4 mi on either side of their center lines. Victor airways are low altitude designated routes that carry commercial and general flights between 3,000 and 18,000 ft.

Approximately at the closest point on Victor 3 to PBAPS is Norris intersection which is established by another radio navigation facility called Lancaster VOR. The intersection is the point at which the airway changes between a "From" bearing and a "To" bearing with respect to the above-mentioned terminal radio facilities. The air traffic on Victor 3 passes PBAPS high overhead in the east-northeast and west-southwest magnetic directions.

2.2.7 Population The information in this section is historical and was submitted in the original FSAR to support the license application unless otherwise noted. For the most current information regarding the population, schools, and recreational and public areas, as well as population density within the sixteen meteorological zones, consult the Emergency Plan. For the most current information regarding operational dose estimates, consult the Annual Radiological Environmental Operating Report and the Annual Effluent Release Report.

CHAPTER 02 2.2-7 REV. 26, APRIL 2017

PBAPS UFSAR The area within a 60-mi radius of the Peach Bottom site covers portions of four states including at least part of 30 counties and the cities of Baltimore and Philadelphia. This area is shown in Figure 2.2.1 by county, township, urban places, cities, boroughs, villages, urbanized areas, etc. Tables 2.2.16 through 2.2.26 show the Census of Population for 1950, 1960, and 1970 and the projected populations for 1970 and 1980 for these and other close-by counties. Projections for 1970 and 1980 are those published by state agencies or the Chamber of Commerce of Metropolitan Baltimore with the exception of the 1980 projections for eight counties in Maryland. The 1980 projections for these eight counties were estimated by extrapolation of growth rates as shown in Figure 2.2.14. The population of the area increased 40 percent between 1950 and 1960 and was projected to increase another 40 percent by 1980.

Beyond 1980, population projections for the area of concern are not provided. However, if the same growth between 1960 and 1980 is projected for 1990 and 2000, the population would increase about 20 percent every 10 yr.

The 1960 Census of Population for the various townships, urban places, cities, boroughs, villages, urbanized areas, etc, that comprise the annular rings between 5 mi and 60 mi of the site is listed in Tables 2.2.17 through 2.2.22 by direction and distance from the site. The populations for the City of Baltimore and the City-County of Philadelphia are listed by election wards to provide smaller population units.

In the tabulation between 20 mi and 60 mi it was assumed that all the people lived at an estimated center of population of each civil division. Between 5 mi and 20 mi, the population of each civil division was apportioned to each annular section, assuming that the population was uniformly distributed within the civil division. The cumulative population from the location of Units 2 and 3 for each of 16 sectors for 0 to 5 mi distance is shown in Figure 2.2.15, and for 5 to 60 mi in Figure 2.2.16.

The population distribution around the site for the years 1950, 1960, 1970, and 1980, and for various distances between 5 and 60 mi and for 16 directions, is shown in Table 2.2.23. The population density for each of these annular sectors is given in Table 2.2.24.

Table 2.2.25 tabulates the 1964 to 1966 population distribution within a 5-mi radius of the Peach Bottom site by radial 1-mi increments and the 16 sectors. This population distribution was determined by counting electric meters and converting to population. This method of determining population is conservative CHAPTER 02 2.2-8 REV. 26, APRIL 2017

PBAPS UFSAR because it automatically includes summer residents. The year-round population within 1-mi of the site is less than one-half of the total listed. Population density for the 0- to 5-mi area, as given in Table 2.2.26, was determined from data in Table 2.2.25. Current population density within 5 mi, as given in Table 2.2.26.1, was determined from data in Table 2.2.25.1.

The comparison between the population distribution from 5 to 60 mi for Peach Bottom Units 2 and 3 of the 1970 Census and the 1970 population as projected in about 1966 according to the sources listed in Table 2.2.16 is presented in Table 2.2.23.1 along with the 1960 and 1980 distributions. The comparison for the same years of the population density is given in Table 2.2.24.1.

The City of Lancaster, located in Lancaster County, Pennsylvania, lies 19.4 mi to the north of the reactors and has 57,690 residents according to the 1970 Census of Population. The corresponding "population center distance," i.e., "the distance from the reactor to the nearest boundary of a densely populated center containing more than about 25,000 residents," for the Peach Bottom site is 17.9 mi. Distances to other population centers of over 25,000 people within a 60-mi radius are shown in Figure 2.2.17. Distances to the center of other large communities are given in Tables 2.2.17 through 2.2.22.

2.2.7.1 Five-to-Sixty-Mile Population Distribution The population within 60 mi of Peach Bottom Units 2 and 3 as reported in the 1970 Census increased 1.8 percent more than was projected at the time of the Final Safety Analysis Report (FSAR).

Growth was slower than projected from the northeast through the south-southeast sectors and faster than projected from the north-northwest through the north-northeast sectors. The remainder of the area had mixed growth performance with respect to projections.

The largest difference between 1970 Census figures and those projected for 1970 at the time of the Peach Bottom FSAR occurred in the southwest sector, particularly between 20 and 40 mi from the site. In this segment, the population exceeds projections by 62 percent and already exceeds what was expected in this area by the year 2000. Such rapid growth has occurred in only two out of the 96 segments analyzed.

Updating with the 1970 Census data has been complicated because the Bureau of Commerce which distributes Census information has not released the maps which show boundary changes of civil divisions and the boundaries of newly created civil divisions. Nevertheless, the 1970 Census of Population is published according to the new CHAPTER 02 2.2-9 REV. 26, APRIL 2017

PBAPS UFSAR boundaries. In all cases except the City and County of Philadelphia and the State of Delaware, the new entities were merged back into the civil divisions from which they were derived.

For Delaware and Philadelphia this merge back into 1960 entities was impossible because they have been completely redefined internally. To accommodate analysis at this time, the 1970 population projections have been used for Philadelphia and Delaware.

Comparison of Census and Projected Population for Philadelphia and Delaware Projected County State 1960 1970 1970 1980 Philadel-phia Co. Pa. 2,002,517 1,948,609 2,074,157 2,180,011 Kent Co. Del. 65,651 81,892 91,800 133,600 New Castle Co. Del. 307,446 385,856 409,700 582,700 Sussex Co. Del. 73,195 80,356 80,900 91,800 Total 2,448,809 2,496,713 2,656,557 2,988,111 Population projections for the decades ahead do not yet reflect the 1970 Census because the agencies which make projections have not all had sufficient time to analyze the factors leading to the differences between the 1970 population as counted by the Census and as they predicted prior to that time. New projections are not anticipated for several years.

2.2.7.2 Zero-to-Five-Mile Population Distribution The resident population and its distribution within 5 mi of Peach Bottom Units 2 and 3 do not appear to have changed significantly since reported in the FSAR. Improvements in the accuracy of the data and in the validity of methods for population distribution analysis are believed to have caused most of the differences between the analysis for the FSAR and the current analysis. During 1970, the licensee was in the process of performing an audit between its customer records used for billing purposes, which are the data used for making local population estimates, versus its geographic maps of customer locations, which are the basis for distributing the population estimates. Because the customer CHAPTER 02 2.2-10 REV. 26, APRIL 2017

PBAPS UFSAR coordinates obtained by the digitizing process of the audit are to be used in the company's computerized Customer Information System, these current data give an improved picture of the population distribution.

North and east of the plant within 5 mi is territory of the Pennsylvania Power and Light Company (PP&L). Since they supplied the population distribution for the Peach Bottom FSAR in 1964, PP&L has digitized its customers also and has produced a new set of maps. Furthermore, adjustment has been made for the 6-deg misalignment between the coordinate system used by PP&L and the licensees coordinate system. This misalignment was not corrected for in the original FSAR submittal.

Within 1 mi of Peach Bottom Units 2 and 3, the resident population was verified by a door-to-door survey conducted in June 1971.

Seasonal dwellings within the first mile were considered to contribute three persons each which is a conservative factor at this time.

The 1970 Census did not include the temporary residences of the construction forces engaged at the PBAPS. This temporary population is estimated to more than double the population of Peach Bottom township in which the facilities are located. After completion of construction, the population should be back in line with the figures reported by the Census.

2.2.7.3 Parameters and Characteristics for a Low Population Zone Although 10CFR50.67 provides the dose acceptance criteria for the PBAPS licensing basis design basis accidents, 10CFR100 was historically used to determine the distance of site boundaries.

The three criteria given in 10CFR100, "Reactor Site Criteria," were considered in selecting the low population zone for Peach Bottom Units 2 and 3. The low population distance of 7,300 m meets all three criteria; therefore, it is acceptable for use in the safety analysis of Units 2 and 3.

The first criterion, as given in 10CFR100.3(b), requires that there be a reasonable probability that appropriate protective measures could be taken in the event of a serious accident.

Table 2.2.25.1 indicates that the estimated 1970 population within 5 mi of the site is less than 6,000. The estimated 1970 population within the 7,300-m low population zone, as shown in Table 2.2.27, CHAPTER 02 2.2-11 REV. 26, APRIL 2017

PBAPS UFSAR is 4,567, representing about 1,600 residences. These are mostly concentrated to the southwest and mostly farther than 3 mi from the plant.

In the unlikely event of an accidental release, released material would not be likely to travel rapidly in all directions at once; it would move with the wind during the period of release. This would further reduce the area and therefore the number of people affected immediately, allowing a longer time to effect protective measures.

If it is assumed a 45-deg sector is affected by the release, the maximum estimated 1970 population that could be affected is 1,288 in the southwest and west-southwest sectors. The annual wind rose at Elevation 688 ft MSL, based on 3 yr of data, indicates the wind only blows toward this 45-deg sector about 7.6 percent of the year.

The estimated 1970 population in the 45-deg sector (southeast and south-southeast) toward which the wind blows most frequently (22.9 percent of the year) is only 328; of these, only 89 live within 4 mi of the site.

The second criterion given in 10CFR100.11(a) (2) specifies a maximum whole-body dose of 25 Rem and a maximum thyroid dose of 300 Rem during an accidental release. The implementation of the Alternative Source Term methodology supersedes the 10CFR100 offsite dose criteria with the dose criterion in 10CFR50.67(b)(2)(ii). Per 10CFR50.67, an individual located at any point on the outer boundary of the low population zone, who is exposed to the radioactive cloud resulting from the postulated fission product release (during the entire period of its passage), would not receive a radiation dose in excess of 0.25 Sv (25 rem) total effective dose equivalent (TEDE).

The highest corresponding calculated doses for any of the design accidents, as listed in Table 14.9.7, is the LOCA dose of 9.59 Rem at 7,300 m. These calculations utilized the NRC assumptions given in Regulatory Guide 1.183. For the elevated Off-Gas Stack scenario, the highest terrain value within a given directional sector between the Station and the LPZ at 7,300 meters was assigned to the LPZ receptor in that given direction. Therefore, a low population zone of 7,300 m conservatively meets this criterion.

The third criterion given in 10CFR100.11(a)(3) specifies that the population center distances must be at least 1 1/3 times the distance to the outer edge of the low population zone.

The outer edge of the selected low population zone is about 4.5 mi (7,300 m). The nearest population center, as shown in Figure 2.2.17 in Lancaster, Pennsylvania, is about 17.9 mi from the CHAPTER 02 2.2-12 REV. 26, APRIL 2017

PBAPS UFSAR units. Based on Lancaster, a maximum low population zone of 17.9 1 1/3 or 13.4 mi is allowed under this criterion. Therefore, the selected low population zone distance of 7,300 m (about 4.5 mi) is well within the criterion and is acceptable on this basis.

CHAPTER 02 2.2-13 REV. 26, APRIL 2017

PBAPS UFSAR TABLE 2.2.1 MAXIMUM ELEVATION OF TERRAIN VERSUS DISTANCE FROM OFF-GAS STACK Distance from Maximum Direction Distance from Direction Off-Gas Stack Elevation of Maximum Off-Gas Stack Elevation of Maximum (ft) Above MSL Elevation (ft) Above MSL Elevation 0 280 - 5,800 470 SSW 100 300 WSW, W, WNW, NW, NNW 6,000 470 SSW 200 310 N, SW, WSW, W, WNW, NW, NNW 6,200 490 SSW 300 330 WNW, NW 6,400 490 SSW 400 340 N, W, WNW, NW, NNW 6,600 490 SSW 500 350 N 6,800 490 SSW 600 360 N, NNW 7,000 490 SSW 700 360 N, NNW 7,200 490 SSW 800 350 N, NNW 7,400 490 SSW 900 340 N, W, WNW, NNW 7,600 490 SSW 1,000 340 W, WNW 7,800 490 SSW 1,100 340 W, WNW 8,000 490 SSW, WNW 1,200 350 W 8,200 490 SSW, WNW 1,300 350 W 8,400 490 SSW, WNW 1,400 350 W 8,600 490 SSW, WNW 1,500 360 NNW 8,800 480 WNW 1,600 380 NNW 9,000 480 SSW 1,700 380 NNW 9,200 500 SW 1,800 380 NNW 9,400 510 SW 1,900 380 NNW 9,600 520 SW 2,000 380 NNW 9,800 530 SW 2,200 380 WNW, NW 10,000 540 SW 2,400 380 WNW 10,200 530 SW 2,600 380 WNW 10,400 500 SW 2,800 390 SSE, S 10,600 500 SW 3,000 400 SSE, S 10,800 510 SW 3,200 400 SSE, S 11,000 520 SW 3,400 420 S 11,200 530 SW 3,600 430 SSW 11,400 550 SW 3,800 420 SSW 11,600 540 SW 4,000 400 S, SSW, SW, W, WNW 11,800 550 SW 4,200 410 S, SSW 12,000 550 SW 4,400 410 S, SW, WNW 12,200 530 SW 4,600 430 SW 12,400 520 SW 4,800 440 SW 12,600 530 SW, NW 5,000 450 SW 12,800 550 SW 5,200 450 SW 13,000 540 SW 5,400 440 SSW, SW 13,200 560 SW 5,600 450 SSW 13,400 560 SW 13,600 550 SW 20,400 660 SW 13,800 550 SW 20,600 670 SW 14,000 570 SW 20,800 670 SW CHAPTER 02 2.2-14 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.1 (Continued)

Distance from Maximum Direction Distance from Direction Off-Gas Stack Elevation of Maximum Off-Gas Stack Elevation of Maximum (ft) Above MSL Elevation (ft) Above MSL Elevation 14,200 590 SW 21,000 670 SW 14,400 590 SW 21,200 670 SW 14,600 590 SW 21,400 670 SW 14,800 590 SW 21,600 680 SW 15,000 600 SW 21,800 690 SW 15,200 610 SW 22,000 690 SW 15,400 600 SW 22,200 670 SW 15,600 590 SW 22,400 670 SW 15,800 590 SW 22,600 670 SW 16,000 590 SW 22,800 660 SW 16,200 590 SW 23,000 660 SW 16,400 590 SW 23,200 690 SW 16,600 610 SW 23,400 690 SW 16,800 610 SW 23,600 690 SW 17,000 620 SW 23,800 710 SW 17,200 630 SW 24,000 720 SW 17,400 630 SW 24,200 740 SW 17,600 630 SW 24,400 740 SW 17,800 630 SW 24,600 740 SW 18,000 630 SW 24,800 803 SW 18,200 630 SW 25,000 760 SW 18,400 630 SW 25,200 780 SW 18,600 630 SW 25,400 760 SW 18,800 640 SW 25,600 730 SW 19,000 650 SW 25,800 730 SW 19,200 650 SW 26,000 730 SW 19,400 650 SW 26,200 725 SW 19,600 650 SW 26,400 680 SW, N 19,800 650 SW 27,000 660 N 20,000 650 SW 27,500 690 N 20,200 650 SW 28,000 680 SW 28,500 690 SW 46,500 930 N 29,000 690 SW 47,000 930 N 29,500 690 SW 47,500 930 N 30,000 700 SW 48,000 930 N 30,500 710 SW 48,500 920 N 31,000 690 SW 49,000 910 N 31,500 670 SW, WNW 49,500 900 N 32,000 670 N, WNW 50,000 890 N 32,500 690 NNW 50,500 880 N 33,000 730 NNW 51,000 870 N 33,500 700 WNW, NNW 51,500 870 N 34,000 700 WNW 52,000 860 N 34,500 720 NNW 52,500 850 N 35,000 760 NNW 53,000 840 N 35,500 800 NNW CHAPTER 02 2.2-15 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.1 (Continued)

Distance from Maximum Direction Distance from Direction Off-Gas Stack Elevation of Maximum Off-Gas Stack Elevation of Maximum (ft) Above MSL Elevation (ft) Above MSL Elevation 36,000 810 NNW 36,500 850 NNW 37,000 840 NNW 37,500 850 NNW 38,000 840 NNW 38,500 840 NNW 39,000 870 N 39,500 870 N 40,000 860 N 40,500 850 N 41,000 830 N 41,500 830 N 42,000 850 N 42,500 850 N 43,000 860 N 43,500 880 N 44,000 890 N 44,500 900 N 45,000 900 N 45,500 910 N 46,000 910 N CHAPTER 02 2.2-16 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.2 PERCENTAGE OF COUNTY LAND USED FOR FARMING IN THE FIVE-COUNTY AREA SURROUNDING THE PEACH BOTTOM SITE Land Used Woodland Total Harvested as not Other County Farmland Cropland Pasture Pastured Farmland Chester, Pa. 55.4 26.0 16.1 5.8 7.5 Lancaster, Pa. 77.4 52.8 13.6 5.0 6.0 York, Pa. 65.7 37.9 10.1 8.4 9.3 Cecil, Md. 56.6 25.5 13.1 11.5 6.5 Harford, Md. 52.9 21.6 17.9 8.5 4.9 Source: 1964 U.S. Census of Agriculture, U.S. Dept of Commerce.

CHAPTER 02 2.2-17 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.3 AGRICULTURAL EMPLOYMENT IN THE FIVE-COUNTY AREA SURROUNDING THE PEACH BOTTOM SITE Number of Agricultural Portion of County Farms(1) Employment(2) County Employment(2)

Chester, Pa. 2,339 5,102 6.6%

Lancaster, Pa. 6,247 9,744 8.6%

York, Pa. 3,816 4,383 4.6%

Cecil, Md. 659 1,181 7.9%

Harford, Md. 1,060 2,056 8.5%

Total 14,121 22,466 (1)

Source: 1964 U.S. Census of Agriculture, U.S. Dept of Commerce.

(2)

Source: County and City Data Book 1962, U.S. Dept of Agriculture.

CHAPTER 02 2.2-18 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.4 VALUE OF FARM PRODUCTS SOLD IN THE FIVE-COUNTY AREA SURROUNDING THE PEACH BOTTOM SITE Total Farm Products Source of Farm Income*

All Dairy Poultry Livestock Other County Value* Rank in State Crops Products Products Products Products Chester, Pa. $ 44,885,470 Second 53.2% 30.3% 4.2% 12.3% .1%

Lancaster, Pa. 109,121,532 First 19.7% 28.0% 27.8% 24.5% .1%

York, Pa. 34,857,686 Third 33.2% 22.9% 24.2% 19.7% .3%

Cecil, Md. 7,984,648 Fifteenth 30.5% 49.5% 8.4% 11.6% .2%

Harford, Md. 11,279,049 Eleventh 17.7% 63.2% 3.9% 15.2% .7%

• Sources: 1. 1964 U.S. Census of Agriculture, U.S. Dept of Commerce.

2. County and City Data Book 1962, U.S. Dept of Commerce.

CHAPTER 02 2.2-19 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.5 EMPLOYMENT IN FIVE-COUNTY AREA SURROUNDING THE PEACH BOTTOM SITE Chester, Lancaster, York, Cecil, Harford Pa. Pa. Pa. Md. Md.

Agricultural Services .48% .56% .14% .19% .65%

Mining .13% .39% .48% 1.08% .74%

Contract Construction 4.44% 5.05% 4.85% 7.27% 8.66%

Manufacturing 50.32% 54.35% 56.67% 48.51% 34.72%

Transportation and Other Public Utilities 6.08% 4.55% 5.01% 5.59% 8.06%

Wholesale Trade 3.90% 4.70% 4.34% 3.25% 2.05%

Retail Trade 15.22% 15.45% 15.55% 19.28% 24.31%

Finance, Insurance, and Real Estate 2.96% 2.75% 2.67% 4.52% 5.33%

Services 16.27% 12.04% 10.16% 9.90% 15.16%

Unclassified .20% .18% .13% .41% .33%

Total Percent 100.00% 100.00% 100.00% 100.00% 100.00%

Total Employment 63,055 100,766 91,528 78,690 13,608 Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-20 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.6 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN CHESTER COUNTY, PENNSYLVANIA Number of Total Type of Product Employees Number of Manufactured Reported Units Reported Food and Kindred Products 3,354 43 Textile Mill Products 1,257 12 Apparel and Related Products 772 14 Lumber and Wood Products 197 16 Furniture and Fixtures

• 5 Paper and Allied Products 1,495 14 Printing and Publishing 1,419 30 Chemicals and Allied Products 1,678 19 Rubber and Plastics Products 1,095 6 Stone, Clay, and Glass Products 1,053 25 Primary Metal Industries 7,874 15 Fabricated Metal Products 1,349 42 Machinery, Except Electrical 2,591 53 Electrical Machinery 5,323 16 Transportation Equipment

• 9 Not Separately Classified -- 24 Total Manufacturing 31,736 343

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-21 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.7 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN LANCASTER COUNTY, PENNSYLVANIA Number of Total Type of Product Employees Number of Manufactured Reported Units Reported Food and Kindred Products 4,370 118 Tobacco Manufacturers 614 12 Textile Mill Products 1,869 18 Apparel and Related Products 6,123 62 Lumber and Wood Products 541 31 Furniture and Fixtures 442 17 Paper and Allied Products 796 12 Printing and Publishing 2,417 65 Chemicals and Allied Products

• 16 Leather and Leather Products 2,850 23 Stone, Clay, and Glass Products 2,438 24 Primary Metal Industries 2,846 33 Fabricated Metal Products 5,801 55 Machinery, Except Electrical 5,188 82 Electrical Machinery 7,513 12 Transportation Equipment 1,109 16 Instruments and Related Products

• 4 Not Separately Classified -- 33 Total Manufacturing 54,779 633

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967-U.S. Dept of Commerce.

CHAPTER 02 2.2-22 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.8 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN YORK COUNTY, PENNSYLVANIA Number of Total Type of Product Employees Number of Manufactured Reported Units Reported Ordnance and Accessories

• 2 Food and Kindred Products 3,753 88 Tobacco Manufacturers 1,127 24 Textile Mill Products 3,485 21 Apparel and Related Products 5,380 50 Lumber and Wood Products 565 23 Furniture and Fixtures 4,294 39 Paper and Allied Products 3,315 29 Printing and Publishing 2,772 44 Chemicals and Allied Products 292 11 Petroleum and Coal Products 294 7 Rubber and Plastics Products 400 5 Leather and Leather Products 2,412 16 Stone, Clay, and Glass Products 1,666 29 Primary Metal Industries 1,831 13 Fabricated Metal Products 3,374 49 Machinery, Except Electrical 8,597 73 Electrical Machinery 2,411 17

• Figures not published to avoid disclosure of operations of reporting units.

CHAPTER 02 2.2-23 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.8 (Continued)

Number of Total Type of Product Employees Number of Manufactured Reported Units Reported Transportation Equipment 1,272 7 Instrument and Related Products

• 2 Not Separately Classified -- 16 Total Manufacturing 51,873 565

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1976 - U.S. Dept of Commerce.

CHAPTER 02 2.2-24 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.9 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN CECIL COUNTY, MARYLAND Number of Total Type of Product Employees Number of Manufactured Reported Units Reported Ordnance and Accessories

• 2 Textile Mill Products 201 4 Apparel and Related Products 368 3 Lumber and Wood Products 91 10 Paper and Allied Products

• 1 Chemicals and Allied Products 313 12 Rubber and Plastics Products

• 1 Primary Metal Industries

• 1 Electrical Machinery

• 2 Transportation Equipment

• 4 Not Separately Classified -- 15 Total Manufacturing 3,817 55

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-25 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.10 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN HARFORD COUNTY, MARYLAND Number of Total Type of Product Employees Number of Manufactured Reported Units Reported Food and Kindred Products 132 7 Apparel and Related Products 420 4 Lumber and Wood Products

• 11 Chemicals and Allied Products 775 8 Rubber and Plastics Products

• 2 Stone, Clay, and Glass Products 428 8 Fabricated Metal Products 454 5 Not Separately Classified -- 14 Total Manufacturing 4,723 59

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-26 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.11 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN THE FIVE-COUNTY AREA SURROUNDING THE PEACH BOTTOM SITE Type of Product Number of Total Number Number of Units Not Manufactured Employees Reported of Units Reported Reporting Employees Ordnance and Accessories

• 4 4 Food and Kindred Products 11,609 256 -

Tobacco Manufacturers 1,741 36 -

Textile Mill Products 6,812 55 -

Apparel and Related Products 13,063 133 -

Lumber and Wood Products 1,394 91 11 Furniture and Fixtures 4,736 61 5 Paper and Allied Products 5,606 56 1 Printing and Publishing 6,608 139 -

Chemicals and Allied Products 3,063 66 16 Petroleum and Coal Products 294 7 -

Leather and Leather Products 5,262 39 -

Rubber and Plastic Products 1,495 14 3 Stone, Clay, and Glass Products 5,585 86 -

Primary Metal Industries 12,551 62 1 Fabricated Metal Products 10,978 151 -

Machinery, Except Electrical 16,376 208 -

Electrical Machinery 15,247 47 2 Transportation Equipment 2,381 36 13 Instruments and Related Products

• 6 6 Not Separately Classified - 102 -

Total Manufacturing 146,928 1,655 -

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-27 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.12 COMPANIES LOCATED WITHIN 10 MILES OF THE PEACH BOTTOM SITE*

(HISTORICAL)

Company Name Approximate Employees Type of Industry Cecil County Fawn Grove Manufacturing Company 100 Sewing factory H.E. Shallcross & Sons 35 Butcher Harford County Blue Ridge Flooring Company 65 Saw milling, flooring C.D. Miller Lumber manufacturing, saw milling Maryland Green Marble Corporation 16 Maryland Verde antique marble Green marble chips Maryland Lava Company 70 Lava insulation, special insulators, Pilot tips Miller Chemical & Fertilizer Corporation 21 Chemicals, fertilizer McCorquodale Color Card Company 22 Color Charts Maryland Ceramic & Steatite Company, Inc. 45 Epoxy and lava products Whitefore Packing Company 150 Canned foods Petti Frocks, Inc., Assoc. 84 Wearing apparel R. Roberts & Son 20 Fuel tanks, refuse containers B. G. S. Jourdan & Sons 55 Canned tomatoes The Susquehanna Electric Company 65 Hydro Electric Plant York County Star Printing Company Printing Weldon Packing Company Canned foods Snyder Packing Company 100 Canned foods PECO Energy 64 Nuclear Power Generating Station Lancaster County Pennsylvania Power & Light Company 150 Hydro Electric Plant

• Companies with less than 10 employees have not been reported.

CHAPTER 02 2.2-28 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.13 COUNTIES LYING WITHIN ABOUT 50 MILES OF THE PEACH BOTTOM SITE Delaware New Jersey New Castle Salem Maryland Pennsylvania Anne Arundel Adams Baltimore* Berks Carroll Chester Cecil Cumberland Harford Dauphin Howard Delaware Kent Lancaster Queen Annes Lebanon York

• Including city of Baltimore CHAPTER 02 2.2-29 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.14 EMPLOYMENT IN COUNTIES WITHIN 50 MILES OF THE PEACH BOTTOM SITE Percent of Employment Total Employment Agricultural Services 3,285 .24 Mining 3,771 .27 Contract Construction 77,983 5.65 Manufacturing 596,897 43.23 Transportation and Other Public Utilities 87,712 6.35 Wholesale Trade 77,517 5.61 Retail Trade 248,209 17.98 Finance, Insurance, and Real Estate 68,752 4.98 Services 213,221 15.44 Unclassified Establishments 2,413 .17

• 1,098 .08 1,380,858 100.00

• Figures not published to avoid disclosure of operation of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-30 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.15 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENTS IN COUNTIES WITHIN APPROXIMATELY 50 MILES OF THE PEACH BOTTOM SITE Type of Product Number of Total Number Number of Units Not Manufactured Employees Reported of Units Reported Reporting Employees Ordnance and Accessories

• 6 6 Food and Kindred Products 49,009 831 4 Tobacco Manufacturers 1,741 36 -

Textile Mill Products 21,379 198 5 Apparel and Related Products 44,783 545 1 Lumber and Wood Products 4,146 242 19 Furniture and Fixtures 10,641 184 11 Paper and Allied Products 19,454 190 3 Printing and Publishing 26,975 665 -

Chemicals and Allied Products 22,874 273 21 Petroleum and Coal Products 1,656 33 6 Leather and Leather Products 9,513 91 17 Rubber and Plastic Products 15,275 103 3 Stone, Clay, and Glass Products 13,823 275 7 Primary Metal Industries 36,032 181 29 Fabricated Metal Products 32,202 531 -

Machinery, Except Electrical 46,970 629 -

Electrical Machinery 50,678 183 11 Transportation Equipment 57,619 132 19 Instruments and Related Products 1,037 57 32 Not Separately Classified - 516 -

Total Manufacturing 595,288 5,901 -

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.2-31 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.15.1 AIRPORTS WITHIN 10 MILES OF THE PEACH BOTTOM ATOMIC POWER STATION Airport Tangelwood Conowingo Ruff Delta Distance (statute mi) 6 1/2 7 4 4 Direction (true north) 36 140 272 226 Elevation (ft) 680 380 465 540 Type Public Public Private, Private, Use Use Restricted Restricted CHAPTER 02 2.2-32 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.16 BUREAU OF CENSUS AND PROJECTED POPULATION OF COUNTIES COUNTY STATE 1950 (l) 1960 (1) 1970 (1) 1970 (2) 1980 (2)

KENT CO. DE. 37870. 65651. 81892. 91800. 133600.

NEW CASTLE CO. DE. 218879. 307446. 385856. 409700. 582700.

SUSSEX CO. DE. 61336. 73195. 80356. 80900. 91800.

ANNE ARUNDEL CO. MD. 117392. 206634. 297539. 316825. 415732.

8ALTIMORE (CITY) MD. 949708. 939024. 905759. 946227. 950840.

8ALTIMORE CO. MD. 270273. 492428. 621077. 645155. 802385.

CALVERT CO. MD. 12100. 15826. 20682. 21890. 26200.

CAROL NE CO. MD. 18234. 19462. 19781. 20570. 20600.

CARROLL CO. MD. 44907. 52785. 69006. 66515. 75225.

CEC L CO. MD. 33356. 48408. 53291. 59713. 72435.

DORCHESTER CO. MD. 27815. 29666. 29405. 30622. 32124.

FREDERICK CO. MD. 62287. 71930. 84927. 86543. 105470.

HARFORD CO. MD. 51782. 76722. 115378. 110525. 150450.

HOWARD CO. MD. 23119. 36152. 61911. 65268. 112835.

KENT CO. MD. 13677. 15481. 16146. 17950. 18830.

MONTGOMERY CO. MD. 164401. 340928. 522809. 508140. 630232.

PR. GEORGES CO. MD. 194182. 357395. 660567. 621057. 770284.

QUEEN ANNES CO. MD. 14579. 16569. 18422. 18289. 19500.

SOMERSET CO. MD. 20745. 19623. 18924. 50698. 19940.

TALBOT CO. MD. 19428. 21578. 23682. 23442. 26585 WASHINGTON CO. MD. 78886. 91219. 103829. 101955. 113765.

WICOMICO CO MD. 39641. 49050. 54236. 55964. 58490.

WORCESTER CO. MD. 23148. 23733. 24442. 25342. 25477.

ATLANTIC CO. NJ. 132399. 160880. 175043. 193200. 226200.

BERGEN CO. NJ. 539139. 780255. 898012. 950000. 1093700.

BURLINGTON CO. NJ. 135910. 224499. 323132. 333000. 413900.

CAMDEN CO. NJ. 300743. 392035. 456291. 490800. 574600.

CAPE MAY CO. NJ. 37131. 48555. 59554. 57000. 67600.

CUMBERL AND CO. NJ. 86597. 106850. 121374. 133300. 159800.

ESSEX CO. NJ. 905949. 923545. 929986. 973400. 1009800.

GLOCESTER CO. NJ. 91727. 134840. 172681. 178200. 229600.

HUDSON CO. NJ. 647437. 610734. 609266. 606000. 612100.

HUNTERDON CO. NJ. 42736. 54107. 69718. 72300. 103700.

MERCER CO. NJ. 229781. 266392. 303968. 323100. 372700.

MIDDLESEX CO. NJ. 264872. 433856. 583813. 622000. 842800.

MONMOUTH CO. NJ. 225327. 334401. 459379. 483500. 655200.

MORRIS CO. NJ. 164371. 261620. 383454. 390100. 571900.

OCEAN CO. NJ. 56622. 108241. 208470. 181000. 270000.

PASSAIC CO. NJ. 337093. 406618. 460782. 483200. 545000.

SALEM CO. NJ. 49508. 58711. 60346. 70400. 86100.

SOMERSET CO. NJ. 99052. 143913. 198372. 207000. 283300.

SUSSEX CO. NJ. 34423. 49255. 77528. 72700. 104300.

UNION CO. NJ. 398138. 504255. 543116. 584600. 638400.

WARREN CO. NJ. 54374. 63220. 73879. 76700. 104100.

ADAMS CO. PA. 44197. 51906. 56937. 58560. 65082.

BERKS CO. PA. 255740. 275414. 296382. 289378. 302383.

BUCKS CO. PA. 144620. 308567. 415056. 395449. 526738.

CARBON CO. PA. 57558. 52889. 50573. 53884. 53376.

CHESTER CO. PA. 159141. 210608. 278311. 283607. 389552.

COLUMBIA CO. PA. 53460. 53489. 55114. 53705. 53500.

CUMBERLAND CO. PA. 94457. 124816. 158177. 156296. 192934.

DAUPHIN COUNTY PA. 197784. 220255. 223834. 233891. 250515.

DELAWARE CO. PA. 414234. 553154. 600035. 620179. 713775.

FRANKL N CO. PA. 75927. 88172. 100833. 106342. 128205.

JUNIATA CO. PA. 15243. 15874. 16712. 17973. 20443.

LACKAWANNA CO. PA 257396. 234531. 234107. 213363. 189405.

LANCASTER CO. PA. 234717. 278359. 319693. 315216. 385471.

LEBANON CO. PA. 78905. 90853. 99665. 98539. 106021.

LEHIGH CO. PA. 198207. 227536. 255304. 243425. 255321.

LUZERNE CO. PA. 392241. 346972. 342301. 338858. 322108.

LYCOMING CO. PA. 101249. 109367. 113296. 112442. 113681.

MIFFLIN CO. PA. 43691. 44348. 45268. 46470. 47712.

MONROE CO. PA. 33803. 39567. 45422. 484l0. 58969.

MONTGOMERY CO. PA. 353068. 516682. 623799. 652966. 814053.

MONTOUR CO. PA. 16001. 16730. 16508. 17492. 18139.

NORTHAMPTON CO. PA. 185243. 201412. 214368. 216781. 233662.

NORTHUMBERLAND CO. PA. 116612. 104138. 99190. 100568. 95790.

PERRY CO. PA. 24782. 26582. 28615. 27565. 28671.

PHILA. CO. PA. 2071605. 2002517. 1948609. 2074157. 2180011.

PIKE CO. PA, 8425. 9158. 11818. 10569. 11617.

SCHUYLKILL CO. PA. 200577. 173027. 160089. 166777. 157506.

SNYDER CO. PA. 22912. 25922. 29269. 32546. 40776.

SULLIVAN CO. PA. 6745. 6251. 5961. 5316. 4394.

UNION CO. PA. 23150. 25646. 28603. 33352. 44321.

WAYNE CO. PA. 28478. 28237. 29581. 31198. 34347.

WYOMING CO. PA. 16766. 16813. 19082. 16295. 15735.

YORK CO. PA. 202737. 238336. 272603. 269554. 306422 (1) BUREAU OF CENSUS (2) PROJECTED POPULATION CHAPTER 02 2.2-33 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.16 (Continued)

SOURCES OF PROJECTED POPULATIONS Year State 1970 1980 1985 1990 2000 Delaware Kent Co. 1 1 2 2 2 New Castle 1 1 2 2 2 Co.

Sussex Co. 3 3 3 3 2 Maryland 4 4 2 2 4 New Jersey 5 5 5 5 5 Pennsylvania 6 6 2 2 2 Year of KEY: Estimate 1 - Division of Urban Affairs, U. of Delaware 1965 2 - Estimate by Philadelphia Electric Company -

3 - Delaware State Planning Office 1967 4 - Maryland State Planning Department 1967 5 - Bureau of Research and Statistics Division 1966 of Economic Development New Jersey Department of Conservation and Economic Development 6 - Pennsylvania State Planning Board 1967 CHAPTER 02 2.2-34 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.17 POPULATION OF MINOR CIVIL SUBDIVISIONS PEACH BOTTOM UNITS 2 AND 3 (HISTORICAL)

CHAPTER 02 2.2-35 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.18 POPULATION OF MINOR CIVIL SUBDIVISIONS PEACH BOTTOM UNITS 2 AND 3 (HISTORICAL)

CHAPTER 02 2.2-36 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.18 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-37 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.19 POPULATION OF MINOR CIVIL SUBDIVISIONS PEACH BOTTOM UNITS 2 AND 3 (HISTORICAL)

CHAPTER 02 2.2-38 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.19 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-39 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.19 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-40 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.20 POPULATION OF MINOR CIVIL SUBDIVISIONS PEACH BOTTOM UNITS 2 AND 3 (HISTORICAL)

CHAPTER 02 2.2-41 REV. 25, APRIL 2015

PBAPS UFSAR Table 2.2.20 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-42 REV. 25, APRIL 2015

PBAPS UFSAR Table 2.2.20 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-43 REV. 25, APRIL 2015

PBAPS UFSAR Table 2.2.20 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-44 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.21 POPULATION OF MINOR CIVIL SUBDIVISIONS PEACH BOTTOM UNITS 2 AND 3 (HISTORICAL)

CHAPTER 02 2.2-45 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.21 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-46 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.21 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-47 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.21 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-48 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.21 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-49 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.22 POPULATION OF MINOR CIVIL SUBDIVISIONS PEACH BOTTOM UNITS 2 AND 3 (HISTORICAL)

CHAPTER 02 2.2-50 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.22 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-51 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.22 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-52 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.22 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-53 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.22 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-54 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.22 (Continued)

(HISTORICAL)

CHAPTER 02 2.2-55 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.23 POPULATION DISTRIBUTION BETWEEN 5 MILES AND 60 MILES OF PEACH BOTTOM UNITS 2 AND 3 BY RADIAL INCREMENT AND DIRECTION FROM SITE (HISTORICAL)

CHAPTER 02 2.2-56 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.23.1 COMPARISON BETWEEN 1970 PROJECTED AND 1970 CENSUS POPULATION DISTRIBUTION BETWEEN 5 MILES AND 60 MILES OF THE PEACH BOTTOM UNITS 2 AND 3 BY RADIAL INCREMENT AND BY DIRECTION FROM SITE (HISTORICAL)

CHAPTER 02 2.2-57 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.24 POPULATION DENSITY* BETWEEN 5 MILES AND 60 MILES OF PEACH BOTTOM UNITS 2 AND 3 BY RADIAL INCREMENT AND BY DIRECTION FROM SITE (HISTORICAL)

CHAPTER 02 2.2-58 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.24.1 COMPARISION BETWEEN 1970 PROJECTED AND 1970 CENSUS POPULATION DENSITY* BETWEEN 5 MILES AND 60 MILES OF PEACH BOTTOM UNITS 2 AND 3 BY RADIAL INCREMENT AND BY DIRECTION FROM SITE (HISTORICAL)

CHAPTER 02 2.2-59 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.25 INITIAL ESTIMATED POPULATION DISTRIBUTION* WITHIN 5 MILES OF THE PEACH BOTTOM UNITS 2 AND 3 BY RADIAL 1-MILE INCREMENTS AND BY DIRECTION FROM SITE (HISTORICAL) 0-1** 1-2 2-3 3-4 4-5 0-5 Direction Mile Miles Miles Miles Miles Miles N - - 89 16 37 142 NNE - 21 24 58 47 150 NE - 6 49 111 54 220 ENE - 26 77 106 280 489 E - - 297 43 80 420 ESE - - - 35 49 84 SE - - - - 50 50 SSE 3 6 - 36 389 434 S 3 29 24 101 115 272 SSW 3 45 16 42 83 189 SW - 51 42 744 857 1,694 WSW 3 22 35 138 67 265 W 6 26 38 80 314 464 WNW 32 32 13 58 144 279 NW 29 141 176 246 207 799 NNW 35 77 24 19 39 194 Total 114 482 904 1,833 2,812 6,145

• Distribution determined by counting electric meters and converting to population. Conversion factors for PECO meters (1966) are based on the 1960 Bureau of Census' population per housing unit factor for York Co., Pennsylvania and Harford Co.,

Maryland, whereas, factors for PP&L meters (1964) are based on the 1960 ratio of the number of customers to the Bureau of Census population for Drumore, Fulton, and Martic Townships, Lancaster Co., Pennsylvania

• • There are no residents within the site boundary (2,500 ft minimum).

CHAPTER 02 2.2-60 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.2.25.1 CURRENT ESTIMATED POPULATION DISTRIBUTION*

WITHIN 5 MILES OF PEACH BOTTOM UNITS 2 AND 3 BY RADIAL 1-MILE INCREMENTS AND BY DIRECTION FROM SITE 0-1** 1-2 2-3 3-4 4-5 0-5 Direction Miles Miles Miles Miles Miles Miles N - - 90 31 45 166 NNE - - 119 28 77 224 NE - 49 59 129 70 307 ENE - 10 94 52 259 415 E - 91 84 129 304 608 ESE - 87 262 63 105 517 SE - - 3 42 106 151 SSE 5 11 - 28 352 396 S - 13 28 120 63 224 SSW 2 27 5 99 116 249 SW - 32 16 651 684 1,383 WSW 13 2 30 126 113 284 W 8 7 14 45 115 189 WNW 36 20 4 100 105 265 NW 21 80 65 100 167 433 NNW 22 46 - 62 18 148 Total 107 475 873 1,805 2,699 5,959

• Distribution is determined by counting electric meters and converting to population. Conversion factors for Conowingo Power Company, a subsidiary of PECO are based on the ratio of the 1970 Census to the number of residential meters, excluding those showing less than five kilowatt hours per day average, which is less than one-quarter the average daily usage of suburban customers. The conversion factor used for PP&L meters, which are northeast of the site across Susquehanna River, is 3.5 people per meter.

• • There are no residents within the site boundary (2,500 ft minimum).

CHAPTER 02 2.2-61 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.26 INITIAL ESTIMATED POPULATION DENSITY*

WITHIN 5 MILES OF PEACH BOTTOM UNITS 2 AND 3 BY RADIAL 1-MILE INCREMENTS AND BY DIRECTION FROM SITE 0-1 1-2 2-3 3-4 4-5 0-5 Direction Mile Miles Miles Miles Miles Miles N - - 148 12 21 38 NNE - 175 24 42 26 35 NE - 16 50 81 30 49 ENE - 84 78 77 158 110 E - - 306 31 45 98 ESE - - - 25 28 23 SE - - - - 33 20 SSE 33 10 - 37 397 125 S 36 49 24 74 65 57 SSW 34 76 16 31 47 39 SW - 86 43 543 484 354 WSW 28 37 30 101 38 55 W 62 44 39 58 177 96 WNW 242 49 33 42 81 58 NW 209 247 205 191 128 179 NNW 333 428 343 21 25 69 Annular Ring 120 80 70 91 105 92

• Population densities are the number of people per square mile of land area. In computing the population density of the 0-1 mi area, the land area of site property is excluded. Populations used are given in Table 2.2.25.

CHAPTER 02 2.2-62 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.26.1 CURRENT ESTIMATED POPULATION DENSITY* WITHIN 5 MILES OF PEACH BOTTOM UNITS 2 AND 3 BY RADIAL 3-MILE INCREMENTS AND BY DIRECTION FROM SITE 0-1 1-2 2-3 3-4 4-5 0-5 Direction Mile Miles Miles Miles Miles Miles N - - 150 23 26 44 NNE - - 119 20 43 52 NE - 131 60 94 39 68 ENE - 32 115 38 146 93 E - 303 109 75 171 142 ESE - 870 655 45 60 142 SE - - 10 60 70 60 SSE 55 18 - 29 359 114 S - 22 28 88 36 47 SSW 23 46 5 73 66 51 SW - 54 16 475 386 289 WSW 121 3 26 92 64 59 W 83 12 14 33 65 39 WNW 272 31 10 72 59 55 NW 151 140 76 78 103 97 NNW 209 225 - 69 12 53 Annular Ring 113 79 68 90 101 89

• Population densities are the number of people per square mile of land area. In computing the population density of the 0-1 mi area, the land area of site property is excluded. Populations used are given in Table 2.2.25.1.

CHAPTER 02 2.2-63 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.27 CURRENT ESTIMATED POPULATION DISTRIBUTION* WITHIN THE LOW POPULATION ZONE** AROUND PEACH BOTTOM UNITS 2 AND 3 BY RADIAL 1-MILE INCREMENTS AND BY DIRECTION FROM SITE 0-1*** 1-2 2-3 3-4 4-4.5 0-4.5 Direction Mile Miles Miles Miles Miles Miles N - - 90 31 38 159 NNE - - 119 28 44 191 NE - 49 59 129 41 278 ENE - 10 94 52 78 234 E - 91 84 129 68 372 ESE - 87 262 63 75 487 SE - - 3 42 31 76 SSE 5 11 - 28 208 252 S - 13 28 120 21 182 SSW 2 27 5 99 49 182 SW - 32 16 651 368 1,067 WSW 13 2 30 126 50 221 W 8 7 14 45 41 115 WNW 36 20 4 100 37 197 NW 21 80 65 100 140 406 NNW 22 46 - 62 18 148 Total 107 475 873 1,805 1,307 4,567

• Distribution determined by counting electric meters and converting to population. Conversion factors for Conowingo Power Company, a subsidiary of PECO, are based on the ratio of the 1970 Census to the number of residential meters excluding those showing less than 5 kWh per day average which is less than one-quarter the average daily usage of suburban customers. The conversion factor used for PP&L meters which are northeast of the site across the Susquehanna River is 3.5 people per meter.

• • Low population zone distance is 7,300 m or about 4.5 mi.

• • • There are no residents within the site boundary (2,500 ft minimum CHAPTER 02 2.2-64 REV. 21, APRIL 2007

PBAPS UFSAR 2.3 METEOROLOGY This section provides information obtained from the meteorological monitoring program in place prior to 1973. On February 7, 1973, Tower 1 was replaced by Tower 1A to allow routing of a 500-kV line over the partially dismantled Tower 1. Tower 1A is only 150 ft from Tower 1 and comparison of the data indicates that the two locations are very similar. Therefore, Tower 1 data is applicable to Tower 1A. In April 1992, the 1A Tower was abandoned in place due to use of Tower 2 and River Tower information.

Other changes involved the removal of the short-term, research-type bivane from the 150-ft level of the microwave tower and the discontinuance of temperature readings at the Hill Pole.

2.3.1 General Meteorological Features The site is located in a well-defined river valley, which in turn lies in rolling but not exceptionally rugged country. Maximum elevations in the immediate vicinity of the facility seldom exceed 300 ft above river level, although there are several plateau sections and hilltops reaching 500 to 800 ft above the river within 10 mi to the southwest, west, northwest, and north of the site. A more complete topographical description of the site and surrounding area is given in paragraph 2.2.4. Nothing in the existing site data or the general records of the area suggests any particularly unusual or disturbing meteorological features.

There is clear evidence of channeling in the valley and of slope-flow on the western shore where the plant is located, but these patterns are not difficult to define. Close to the steep, western side of the valley, virtually all stable atmospheric conditions are accompanied by downslope motion, with the air flowing out over the river and then either up or down stream. In unstable conditions, accompanied by local solar heating, the pattern is more varied, but channeling is also quite apparent.

At higher elevations, the wind flow becomes progressively divorced from valley effects until, at Elevation 688 ft MSL (height above mean sea level) near the top of the microwave tower, it is difficult to see the channeling, and the distribution of wind directions and speeds is typical of the unrestricted flow of the eastern United States.

The frequency of stable dispersion conditions is normal for a location of this type, averaging approximately 30 percent of all CHAPTER 02 2.3-1 REV. 25, APRIL 2015

PBAPS UFSAR hours annually and reaching a peak of about 45 percent during the most stable months.

The meteorological conditions with respect to annual radioactive effluent releases from the plant stack and reactor building roof vents have been evaluated for all points on the site land boundary and along the waterline. Based on that evaluation, it was determined that the point on the site boundary described in Appendix E, paragraph E.3.3.1, receives the maximum annual dose.

Therefore, for normal plant operation, the pond can be considered as an unrestricted area.

2.3.2 Sources of Data The Peach Bottom site is equipped with two meteorological towers and two satellite wind instruments, all of which have been operating long enough to provide a good understanding of wind patterns and stability at almost any elevation of interest in design and operation of the facility. The locations and elevations of the equipment, which have been divided into two weather stations (designated No. 1 and No. 2) are listed in Table 2.3.1 and shown in Figures 2.3.1 and 2.3.2. In addition to the instruments located on towers, a continuous record of relative humidity and precipitation is obtained at the base of both the microwave tower and Weather Tower No. 1, and atmospheric pressure is recorded at the base of the microwave tower.

Two years of records (August, 1967 through July, 1969) from both the new meteorological equipment installed at Weather Station No.

2 to provide data for Units 2 and 3 and the original equipment at Weather Station No. 1 installed in 1959 for Unit 1 have been processed and analyzed. The instruments have operated satisfactorily. Data obtained from the weather instrumentation at Weather Station No. 1 complements that from the high-level tower.

The Aerovane installed over the river has been in service for a shorter period of time (since July 1968), but the data from it have been most helpful in establishing flow patterns from the site over the river.

The meteorological monitoring program was upgraded in 1983 to conform to the requirements of Regulatory Guide 1.23, proposed Rev. 1. The details of this upgrade are discussed in Section 2.3.3.

Background data on high winds, tornadoes, and other relatively unusual phenomena have been derived from long-term records in the general area. These records are from National Weather Service CHAPTER 02 2.3-2 REV. 25, APRIL 2015

PBAPS UFSAR stations in Philadelphia and Harrisburg Pennsylvania, Wilmington Delaware, and Baltimore Maryland.

2.3.3 Onsite Meteorological Measurements 2.3.3.1 Meteorological Measurements Program, 1967-1982 Data Collection at the Peach Bottom site began with the installation of Weather Station No. 1 in 1959 for use in the licensing of Unit 1. The meteorological monitoring program in support of Units 2 and 3 began in August 1967. This program included measurements at Towers No. 1 and No. 2 and the Hill Pole.

Tower No. 1 was located on the river bank slightly southeast of Unit 1 near the visitors center. Wind direction and speed were measured at two levels, along with ambient temperature, temperature lapse rate, precipitation and relative humidity. In 1973 Tower 1 was replaced with Tower 1A. Tower 1A has identical measurement levels and instrument exposure, but was located approximately 150 ft. from Tower 1 to avoid interference with overhead transmission lines.

Tower No. 2 (microwave tower) is located on the bluff slightly north and west of Units 2 and 3. Wind speed and direction were measured at two levels on Tower 2, along with ambient temperature, temperature lapse rate, precipitation and relative humidity. In addition, bivane measurements were taken at Tower 2 for a brief period.

The Hill Pole is located directly behind Units 2 and 3 on the bluff near the base of the off-gas stack. Wind speed and direction, and ambient temperature were measured at one level. An additional wind sensor was installed at the River Tower in August 1968.

The location and elevation of all sensors in the Peach Bottom meteorological monitoring program are documented in Table 2.3.1.

The locations of the meteorological towers and their elevations with respect to the local terrain and gaseous effluent release points are shown in Figures 2.3.1 and 2.3.2.

2.3.3.2 Meteorological Measurements Program, 1983 - Present The meteorological monitoring program was upgraded during the period October 1982 through May 1983 to conform to the new requirements of Regulatory Guide 1.23, proposed Rev. 1, and NUREG-0654.

CHAPTER 02 2.3-3 REV. 25, APRIL 2015

PBAPS UFSAR 2.3.3.2.1 Measurements and Instrumentation 2.3.3.2.1.1 Siting The upgraded meteorological system in general utilizes the same tower locations and instrument elevations as the previous system shown in Figures 2.3.1 and 2.3.2. The only exceptions to this are the addition of two wind levels on Tower No. 2 and a change in the delta temperature measurement interval at Tower No. 2. These changes were made to conform with Regulatory Guide 1.23, proposed Rev. 1, and are documented in Table 2.3.1-A.

2.3.3.2.1.2 Instrumentation and Performance Specifications The upgraded instrumentation systems installed at Peach Bottom were designed to meet the requirements of Regulatory Guide 1.23, proposed Rev. 1.

2.3.3.2.1.3 Windspeed The Bendix Aerovane Wind Transmitter has been removed. This instrument is not required by Regulatory Guide 1.23, proposed Rev.

1, and does not meet the required starting speed.

All other wind speed measurements are provided by Climatronics three-cup anemometers. A 30-hole photochopper with an LED photochopper device provides a frequency output directly proportional to wind speed.

2.3.3.2.1.4 Wind Direction The Bendix Aerovane Wind Transmitter has been removed.

All other wind direction measurements are provided by Climatronics Wind Direction Sensor. The sensor consists of a counterbalanced, light weight vane and a precision, low torque, highly reliable potentiometer to yield a voltage output proportional to the wind direction.

2.3.3.2.1.5 Sigma Theta (Standard Deviation)

Standard deviation of wind direction is computed utilizing two methods, one for analog and one for digital data output.

CHAPTER 02 2.3-4 REV. 25, APRIL 2015

PBAPS UFSAR 2.3.3.2.1.5.1 Sigma Theta (Analog)

Analog output of the standard deviation of wind direction is computed by the Climatronics sigma computer using a CMOS microprocessor with a sampling rate of 1 per second. Each wind sample is converted from polar to rectangular coordinates with northern and eastern components. From this, the standard deviation (sigma theta) is computed over an interval of 15 minutes.

2.3.3.2.1.5.2 Sigma Theta (Digital)

The Sigma Theta Digital computation has been removed.

2.3.3.2.1.6 Temperature The ambient temperature measuring system uses a standard 100 Ohm, 4-wire platinum RTD. Climatronics platinum temperature translator provides a voltage output of 0 to 5 volts corresponding to an ambient temperature of -30 to 120F. Each translator is calibrated to its comparison sensor which enables precise measurement accuracy. The nonlinear sensor response is compensated for by the translator electronics to provide an excellent fit to the Callendar-Van Dusen Equation. These sensors are housed in a Climatronics motor-aspirated temperature/dew point shield.

2.3.3.2.1.7 Temperature Difference The temperature sensors used in determining temperature difference are identical to those used for ambient temperature. Climatronics platinum temperature difference translator provides a voltage output of 0 to 5 volts corresponding to a temperature difference of -10 to 20F. These sensors are housed in the motor-aspirated temperature shield.

2.3.3.2.1.8 Dew Point Dew point temperature is measured using Climatronics Lithium Chloride dew point sensor. The dew point translator provides a voltage output of 0 to 5 volts corresponding to -30 to 120F. The sensor is housed in the motor-aspirated temperature/dew point shield at the same elevations as the ambient temperature sensors.

CHAPTER 02 2.3-5 REV. 25, APRIL 2015

PBAPS UFSAR 2.3.3.2.1.9 Precipitation Precipitation is measured using a gauge of the "tipping bucket" type. Each tip of the bucket equals 0.01 inches of water. The gauge has an electrical heater for operation with snow or freezing rain. The gauge is manufactured by Climatronics Corp. The translator for this unit consists of an electronic counter and an A-D signal converter. The counter will recycle to 0 on the 100th count.

2.3.3.2.2 Calibration and Maintenance Procedures 2.3.3.2.2.1 Calibration All sensors and related equipment are calibrated according to written procedures designed to ensure adherence to Regulatory Guide 1.23, proposed Rev. 1, guidelines for accuracy.

Calibrations occur at least every six months, with component checks and adjustments performed when required.

All meters and other equipment used in calibrations are, in turn, calibrated at scheduled intervals. All instruments used in calibrations are traceable to the National Bureau of Standards.

2.3.3.2.2.2 Maintenance Inspection and maintenance of all equipment is accomplished in accordance with the contractors procedures approved by Exelon Generation. Inspections occur at least once per month by qualified individuals capable of performing the maintenance if required. The results of the inspections, maintenance and calibrations performed are reported in the Monthly Report issued to the Station.

2.3.3.2.3 Data Communication, Recording and Display Data from all tower locations are digitized at the base of the respective tower and transmitted to the control room and to an on-site computer for archive storage. The digitized data are available on computer terminals in the control room and Emergency Operations Facility (EOF) and are available for remote interrogation by the licensee, the NRC and State governments.

Data from Tower 2 is recorded at the base building at the tower and in the control room. Data from the River Tower are transmitted via radio telementry to the base of Tower 2, where the CHAPTER 02 2.3-6 REV. 25, APRIL 2015

PBAPS UFSAR data are recorded, as well as in the control room. Data from the Hill Pole are recorded in the control room only.

Weekly, all data is sent to an approved licensee meteorological consultant for data processing and analysis.

2.3.3.2.3.1 Data Analysis Procedures 2.3.3.2.3.1.1 Data Quality Control The digital data acquisition systems are checked daily to monitor system performance. The evaluation criteria vary from parameter to parameter, but the overall objective is to identify potential problems and to notify plant personnel as soon as possible in order to minimize system down time. This procedure is performed on each working day.

All analog data is subject to a quality check. Analog data is inspected for the following items:

a. Verification of log sheets versus actual data received

b. Time continuity

c. Instrument malfunction

d. Directional switching problems

e. Missing data 2.3.3.2.3.1.2 Data Reduction Digital *hourly averages, for all meteorological parameters, are taken from the PMS Computer (1985 - 1992) and the Plant Monitoring System (1993 - Present). Calibration corrections are applied and the data analyzed prior to input to the licensees meteorological data base. (*Precipitation is an hourly total.)

2.3.4 Standard Meteorological Data 2.3.4.1 Temperature The distribution of hourly temperatures at Weather Stations No. 1 and No. 2 is shown in Tables 2.3.4 and 2.3.5, respectively. There are no notable differences between the two stations, and both reflect what would be expected in this general location; a few CHAPTER 02 2.3-7 REV. 25, APRIL 2015

PBAPS UFSAR winter temperatures in the 5 to 10F range and occasional readings above 90F in the summer.

2.3.4.2 Precipitation Precipitation data (representing rain, melted snow, etc) were obtained during the entire 2-yr period at Weather Station No. 1, but observations did not begin at Weather Station No. 2 until December, 1967. Data from the two stations are presented in Tables 2.3.6 and 2.3.7.

2.3.4.3 High Winds The general wind flow in the site area is moderate. In terms of observational data, the long records of the Philadelphia area are of interest, and these suggest that peaks in excess of 75 mph are quite rare (Table 2.3.8). These modest peak winds are to be expected, since the site is too far inland to be affected by the full force of the hurricanes, and it is not usually influenced by any other phenomena producing exceptional wind speeds. The peak winds observed at the site during the 2-yr period are listed in Table 2.3.9.

The tornado frequency in the site area has been investigated. The particular 1-degree square surrounding the site has been affected by tornadoes 22 times during the period 1916 to 1961, according to Spohn's Tornado Climatology1. Using his technique for reducing the frequency of occurrence to the chance of a tornado affecting the site, the probability is found to be 1 in 2,600 years.

2.3.4.4 Ice Storms There is a fairly high probability of severe ice storms in this part of Pennsylvania, and there have been numerous instances in which disruption of power, communications, and transportation facilities have occurred. One severe ice storm can be expected every 3 years between December and February(2,3) 2.3.5 Diffusion Meteorology 2.3.5.1 Turbulence Classification The method of separating dispersion conditions according to the turbulence indicated by the wind direction fluctuations of a standard Bendix-Friez Aerovane has been used as a classification system in the analysis. The technique depends upon the magnitude of the angular swings of the vane as well as certain qualitative CHAPTER 02 2.3-8 REV. 25, APRIL 2015

PBAPS UFSAR characteristics of the recorded trace over the hourly sampling period, as detailed in Table 2.3.10. Much of the analysis is based on this classification system. (Turbulence Classification is no longer performed using the Bendix-Friez Aerovane.)

The monthly and annual distributions of the five turbulence classes are listed in Tables 2.3.11 and 2.3.12 for the highest Aerovane location on each of the main towers; namely, the nominal 100-ft level (Elevation 411 ft MSL) at Weather Station No. 1 and the nominal 320-ft level (Elevation 688 ft MSL) at Weather Station No. 2. The distributions at these two locations are similar, and they are also in accord with the results obtained at the site where the classification was originally used. The dominant classes at all seasons of the year are II and V, which are the typical daytime and typical nocturnal turbulence regimes, respectively. The low-level station, however, shows more stable Class V cases in the spring and less in the fall, as would be expected, since the seasonal relation between river and air temperatures favors such a result. The Class IV turbulence, representing the typical storm situation, is least prominent at both stations in the summer and accounts for approximately 15 percent of the hours during the remainder of the year. The Class I and III cases represent light wind conditions with convective turbulence, and are relatively infrequent at both stations.

Table 2.3.13 shows the relationship between lapse rates and the turbulence classes on an annual basis. The unstable cases are obviously Classes I, II, and III. Class IV is slightly more stable and Class V is the dominantly stable condition. The agreement between turbulence class and lapse rate is not perfect, however, indicating that factors other than thermal stability influence the turbulence.

2.3.5.2 Wind Direction Distributions Complete wind rose data from all of the instruments are available in Appendix N, but only selected wind roses illustrating the typical flow patterns at various altitudes under the important stability conditions are presented in detail. Wind roses for the 3-month periods January-February-March and July-August-September for stability classifications II and V, the typical daytime and nocturnal inversion cases, respectively, are shown in Figures 2.3.3 through 2.3.22. Annual wind roses for all classes of wind combined for each Aerovane location are given in Figures 2.3.23 through 2.3.28. The annual directional distribution of wind for each class and all classes combined for the highest Aerovane location on each main tower is presented in Tables 2.3.14 and CHAPTER 02 2.3-9 REV. 25, APRIL 2015

PBAPS UFSAR 2.3.15. (Wind Direction Distributions are no longer performed using the Bendix-Friez Aerovane.)

2.3.5.2.1 Class II At the center of the river during both cold and warm months (Figures 2.3.11 and 2.3.12), there is a strong tendency for flow parallel to the valley, with a predominant downriver flow in winter giving way to an even upriver and downriver distribution in the warmer months. The same tendency exists at the nominal 30-ft level on Tower No. 1 (Figures 2.3.3 and 2.3.4). At the nominal 100-ft level, the Hill Pole, and the nominal 320-ft level, less marked preferences are found, although NW, N, and S winds are clearly preferred (Figures 2.3.5 through 2.3.10).

2.3.5.2.2 Class V At the higher elevations, represented in Figures 2.3.15 through 2.3.20, the flow under stable conditions is not well defined, with modest preference for various directions at the nominal 100-ft level, at the Hill Pole, and at the nominal 320-ft level. At the two lower elevations, a striking illustration of the slope and valley flow is observed. At the nominal 30-ft elevation (Figures 2.3.13 and 2.3.14) the wind during stable conditions is almost exclusively downslope from the west, moving over the river. As shown in Figures 2.3.21 and 2.3.22, the air then tends to move upstream or downstream, although more commonly downstream in summer. It is at first suprising to observe upstream flow during stable conditions, since the literature would predict a marked favoritism for downstream motion, but the dammed-up river is virtually flat in this locality, and the normal pattern does not exist.

2.3.5.3 Wind Speed Distributions The wind speed for the same set of meteorological conditions and seasons is summarized for all stations in Table 2.3.16. The nominal 320-ft level shows the highest speeds under all conditions, as would be expected from its position well above the terrain. The river vane shows the next highest speed, because it is well exposed, and even under stable conditions the flow is appreciable. The nominal 100-ft level, nominal 30-ft level, and the Hill Pole elevation all exhibit very light winds, especially in stable conditions, because they are almost completely shielded from the normal gradient aloft and from the developed flow over the river.

CHAPTER 02 2.3-10 REV. 25, APRIL 2015

PBAPS UFSAR The percentage frequency distribution of wind speed as a function of stability classification for each location is shown in Tables 2.3.17 to 2.3.22. These tables clearly reflect the probability of low wind speeds close to the ground.

2.3.5.4 Lapse Rates The thermal stability, as evidenced by the temperature differences between different elevations on the towers, is summarized in Tables 2.3.23 and 2.3.24. These tables list the distribution among lapse rate groups over the year. Figures 2.3.20 through 2.3.36 depict the mean diurnal variation in lapse rate for 1 month in each season. A single representative month in each season gives essentially the same pattern as the data for the entire season.

There is nothing unusual about any of the lapse rate distributions. They seem quite normal in every respect, and the differences observed between Weather Stations No. 1 and No. 2 are what would be anticipated. The lower tower shows more marked variations from day to night with rather steep inversions, particularly in the spring when the river water is cold and in the fall when the general climatic conditions favor inversions. The upper tower shows relatively shallow inversions and it probably often extends above the top of the surface inversion layers.

2.3.5.5 Steadiness Analysis The records form the nominal 100-ft level of the lower tower (Weather Station No. 1) and the nominal 320-ft level (Weather Station No. 2) have been analyzed for wind steadiness to determine the probability of nearly invariant wind direction occurring for extended periods of time.

The study shows that for periods up to 24 hr, very steady wind directions under stable as well as unstable conditions must be expected approximately once every year or two. At the lower elevation (Table 2.3.25) the preferred directions regardless of stability are SE and NW, but the slope flow from the WNW prevails under stable conditions. At the nominal 320-ft level on the upper tower (Table 2.3.26) the favored directions are NW and SE almost exclusively.

For periods longer than 1 day, steady winds (even over an 18-deg sector) are uncommon under any stability conditions, but a finite probability of having almost invariant winds for 48 hr on the CHAPTER 02 2.3-11 REV. 25, APRIL 2015

PBAPS UFSAR lower tower (Weather Station No. 1) with stable conditions is found, even though the return period is 160 months.

2.3.5.6 Bivane Fluctuations The bivane mounted at a nominal 150-ft level (Elevation 518 ft MSL) on the microwave tower has been troublesome (as has been true for this type of instrument at most sites). Nevertheless, it has been possible to extract a reasonable amount of short-term fluctuation data from it. There is growing evidence, however, that these light bivanes are suitable only for brief research investigations, and produce unreliable data in continuous field service if not recalibrated frequently.

The data obtained from the Peach Bottom instrument are summarized in Table 2.3.27. The mean and modal (most frequently occurring) values of the hourly angular ranges of the horizontal and vertical fluctuations of the vane are given for the four prominent turbulence classes. The standard deviations of the fluctuations (a for the horizontal directions and e for the vertical directions) have been computed from the ranges. The values seem reasonable and compare favorably with those observed in other experiments, although the ratio of e/ a for the stable, Class V turbulence is larger than that observed at Brookhaven. It is difficult to say whether this difference is real, but it is probable that the rough terrain introduces somewhat more vertical motion in otherwise stable conditions.

2.3.5.7 Dispersion Parameters Because of the terrain effect at the site, it is impossible to arrive at a simple set of dispersion parameters that will encompass most of the conditions encountered. Rather, the fate of each release will be strongly dependent upon its precise location, and must be treated uniquely.

At elevations well above the hilltops (e.g., at Elevation 688 ft MSL), there is little question that the simple expressions of dispersion parameters, such as the Pasquill values (5) or the ASME dispersion parameters(6) , would apply. At elevations somewhat closer to the hilltops, there is probably more vertical dispersion that suggested in these references, and it is probable that some of the excess vertical turbulence shown by the bivane is real.

A release within 50 ft of the slope, however, must be described in terms of trajectory and confining topography as well as simple dispersion. With unstable conditions, the most likely flow is a CHAPTER 02 2.3-12 REV. 25, APRIL 2015

PBAPS UFSAR gentle drift up or down valley having relatively large vertical and horizontal eddies but unusually light wind speeds. Under stable conditions, such a release is almost certain to drift slowly to the east over the river at a speed less than 1 m/sec, and then to turn either northwest or southeast and gradually expand laterally until confined by the valley walls.

2.3.5.8 Least Favorable Meteorological Conditions From the extensive meteorological measurements made at Peach Bottom, it is possible to estimate least favorable meteorological conditions which might be expected. These least favorable conditions listed in Table 2.3.28 for both an elevated release (Elevation 765 ft) and a ground release were calculated such that 95 percent of the time diffusion would be better or, conversely, 5 percent of the total time diffusion would be more restrictive than that resulting from the conditions listed.

2.3.6 Summary and Conclusions The unusually detailed set of data, begun before the construction of Unit 1 and extended to higher elevations and over the pond to meet the needs of Units 2 and 3, have defined the flow pattern in and over the valley quite adequately for both short- and long-term safety evaluations. The analysis confirms the existence of two rather distinct dispersion zones, one pertaining to the valley and the other representative of the more general synoptic pattern above it. In the Preliminary Safety Analysis Report, the speculation was offered that the downslope flow from west to east over the site during stable conditions would probably turn downstream rather than proceed across the valley. This speculation appears to have been essentially correct, but the flow over the river apparently may turn either northwest or southeast, rather than always proceeding down valley; the slope of the valley is apparently too slight to exert a determining influence on the direction during stable conditions.

The recent analysis has not uncovered any specialized conditions that were not anticipated in the earlier reports, and it is believed that the probable fate of any release over or above the site can be accurately estimated from the data available.

CHAPTER 02 2.3-13 REV. 25, APRIL 2015

PBAPS UFSAR Off-Gas Stack Tower 2: NA Tower 2: 316 - 33 320 Unit 2 Reactor Tower 2: NA Tower 2: 150 - 33 Building Stack 33 Unit 3 Reactor Tower 2: NA Tower 2: 150 - 33 Building Stack 33

• - Secondary data used only for those hours when primary data are missing except for PAVAN Control Room X/Q calculation for releases from the Off-Gas Stack. In this case, only primary data are used.

NA - Not Applicable Topographic cross-sectional profiles depicting the meteorological monitoring towers and the station stacks are provided in Figure 2.3.37.

As shown in the preceding table, two (2) towers were selected to be utilized for /Q calculations at the Control Room Intake for releases from the Units 2 and 3 Reactor Building Stacks. These stacks are not tall enough to avoid building-induced downwash; therefore, with zero (0) exit velocity having been assumed, ARCON96 treats their releases as a 'ground-level' type.

Accordingly, the Tower 1A data would appear to be the representative database for the Reactor Building stacks.

However, since these stack tops are at 305 ft msl, and thus, are actually nearer in the vertical to the Tower 2 grade elevation (367 ft msl) than they are to the Tower lA grade elevation (119 ft msl), an ARCON96 analysis is also performed using the most appropriate Tower 2 data, as indicated in the preceding table.

It was desired that a continuous five-year period of data common to all 3 towers, and for which available data meet NRC Regulator)

Guide 1.23 (Reference 7) specifications be utilized for these calculations. The period of 1984 through 1988 was selected.

2.3.7.3 Calculation of /Q at the EAB and LPZ

/Q was calculated at the EAB (823 m) and LPZ (7300 m) for the Off-Gas Stack and the Units 2 and 3 Reactor Building Stacks using the NRC-recommended model PAVAN (Reference 8). The Off-Gas Stack was executed as a stack type release, which results in non-fumigation /Q values as well as fumigation values. However, the Units 2 and 3 Reactor Building Stacks do not qualify as elevated releases as defined by Regulatory Guide 1.145 (Reference 9), therefore, they are executed as ground type releases with a result of non-fumigation /Q values only.

For stack releases during non-fumigation conditions, the equation CHAPTER 02 2.3-15 REV. 25, APRIL 2015

PBAPS UFSAR for ground-level relative concentration at the plume centerline is:

1 -he2

/Q = exp (2.3.7-1) h y z 2z2 where:

/Q is relative concentration, in sec/m3 h is wind speed representing conditions at the release height, in m/sec y is lateral plume spread, in m, a function of atmospheric stability and distance z is vertical plume spread, in m, a function of atmospheric stability and distance is 3.14159 he is effective stack height, in m: he = hs - ht hs is the initial height of the plume (usually the stack height) above plant grade, in m ht is the maximum terrain height above plant grade between the release point and the point for which the calculation is made, in m. If ht is greater than hs then he = 0 For stack release during fumigation conditions, the equation for ground-level relative concentration at the plume centerline is:

1

/Q = , he > 0 (2.3.7-2) 1/2 (2) h ey he he is wind speed representative of the fumigation layer of depth he, in m/sec; in lieu of information to the contrary, the NRC staff considers a value of 2 m/sec as a reasonably conservative assumption for he of about 100 m.

y is the lateral plume spread, in m, that is representative of the layer at a given distance; a moderately stable (F) atmospheric stability condition is usually assumed.

For the fumigation case that assumes F stability and a wind speed of 2 m/s, Equation 2.3.7-1 should be used instead of 2.3.7-2 at distances greater than the distance at which the /Q values determined using Equation 2.3.7-1 with he = 0 and Equation 2.3.7-2 are equal.

CHAPTER 02 2.3-16 REV. 25, APRIL 2015

PBAPS UFSAR

/Q values at the EAB and LPZ were calculated in accordance with Regulatory Guide 1.145. For ground-level releases, calculation for the 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following the accident were based on the following equations:

1

/Q = (2.3.7-3) 10(y z + A/2) 1

/Q = (2.3.7-4) 10(3y z) 1

/Q = (2.3.7-5) 10(y z) where:

/Q is relative concentration, in sec/m3 is 3.14159 10 is wind speed at 10 meters above plant grade, in m/sec y is lateral plume spread, in m, a function of atmospheric stability and distance z is vertical plume spread, in m, a function of atmospheric stability and distance y is lateral plume spread with meander and building wake effects (in meters), a function of atmospheric stability, wind speed, and distance [for distances of 800 m or less, y=My, where M is determined from Reg. Guide 1.145 Fig. 3; for distances greater then 800 m, y=(M-1)y800m + y A is the smallest vertical-plane cross-sectional area of the reactor building, in m2. (Other structures or a directional consideration may be justified when appropriate.)

Plume meander is only considered during neutral (D) or stable (E, F, or G) atmospheric stability conditions. For such, the higher of the values resulting from Equations 2.3.7-3 and 2.3.7-4 is compared to the value of Equation 2.3.7-5 for meander, and the lower value is selected. For all other conditions (stability classes A, B, or C), meander is not considered and the highest /Q value of equations 2.3.7-3 and 2.3.7-4 is selected.

CHAPTER 02 2.3-17 REV. 25, APRIL 2015

PBAPS UFSAR The /Q values calculated at the EAB based on meteorological data representing a 1-hour average are assumed to apply for the entire 2-hour period.

To determine the maximum sector /Q value at the EAB, a cumulative frequency probability distribution (probabilities of a given /Q value being exceeded in that sector during the total time) is constructed for each of the 16 sectors using the /Q values calculated for each hour of data. This probability is then plotted versus the /Q values and a smooth curve is drawn to form an upper bound of the computed points. For each of the 16 curves, the /Q value that is exceeded 0.5 percent of the total hours is selected and designated as the sector /Q value. The highest of the 16 sector /Q values is the maximum sector /Q.

Per RG 1.145, Peach Bottom is classified as an inland site (more than 3.2 km from large bodies of water such as oceans or Great Lakes); therefore, the maximum sector /Q value at the EAB is determined by comparison of the sector fumigation and non-fumigation (as determined in the above paragraph) /Q values. If the fumigation value is greater, then it is used for the 0 - 0.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> time period and the non-fumigation value is used for the 0.5 - 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> time period. Otherwise, the non-fumigation sector value is used for the entire 0-2 hour time period.

Determination of the LPZ maximum sector /Q is based on a logarithmic interpolation between the 2-hour sector /Q and the annual average /Q for the same sector. For each time period, the highest of these 16 sector X/Q values is identified as the maximum sector /Q value. The maximum sector /Q values will, in most cases, occur in the same sector. If they do not occur in the same sector, all 16 sets of values are used in dose assessment requiring time-integrated concentration considerations. The set that results in the highest time-integrated dose within a sector is considered the maximum sector

/Q.

The maximum sector /Q at the LPZ for stack releases during fumigation conditions at inland sites are determined in the same manner as the EAB (See paragraph 2 of this section).

The 5% overall site /Q value for the EAB and LPZ is determined by constructing an overall cumulative probability distribution for all directions. The value of /Q is plotted versus the CHAPTER 02 2.3-18 REV. 25, APRIL 2015

PBAPS UFSAR probability of it being exceeded, and an upper bound curve is drawn. From this curve, the 2-hour /Q value that is exceeded 5%

of the time is found. The 5% overall site /Q at the LPZ for intermediate time periods is determined by logarithmic interpolation of the maximum of the 16 annual average /Q values and the 5% 2-hour /Q values.

2.3.7.3.1 PAVAN Meteorological Databases The meteorological databases to be utilized for the EAB and LPZ

/Q calculations (shown in Section 2.3.7.2) were prepared for use in PAVAN by transforming the five years (i.e., 1984-1988) of hourly meteorological tower data observations into joint wind speed-wind direction-stability class occurrence frequency distribution as shown in Table 2.3.29. In accordance with Regulatory Guide 1.145, atmospheric stability class was determined by vertical temperature difference between the release height and the 10-m level, and wind direction was distributed into 16 - 22.5o sectors.

Eleven (11) wind speed categories were defined according to Regulatory Guide 1.23 with the first category identified as "calm." The higher of the starting speeds of the wind vane and anemometer (i.e., 0.50 mph) was used as the threshold for calm winds, per Regulatory Guide 1.145, section 1.1. A midpoint was also assumed between each of the Regulatory Guide 1.23 wind speed categories, Nos. 2-10 as to be inclusive of all wind speeds. The wind speed categories have therefore been defined as follows:

PAVAN /Q Wind Speed Categories Wind Speed Categoriesa (Regulatory Guide 1.23, Revision 1)

Category Wind Speed (mph) 1 (Calm)b <0.5 2 >=0.5 to <2.35 3 >=2.35 to <3.47 4 >=3.47 to <4.59 5 >=4.59 to <6.82 6 >=6.82 to <9.06 7 >=9.06 to <11.30 8 >=11.30 to <13.53 9 >=13.53 to <18.01 10 >=18.01 to <22.37 11 >=22.37 CHAPTER 02 2.3-19 REV. 25, APRIL 2015

PBAPS UFSAR a

To be inclusive of all monitored wind speeds, a midpoint was assumed between each designated wind speed category.

b The higher of the starting speeds of the Climatronics wind vane and anemometer equipment (i.e. 0.50 mph) was used as the threshold for calm winds, per Regulatory Guide 1.145, Section 1.1.

In the equations shown in Section 2.3.7.3, it should be noted that wind speed appears as a factor in the denominator. This causes obvious difficulties in making calculations for periods of calm. The procedures used by PAVAN assign a direction to each calm period according to the directional distribution for the lowest wind-speed class. This is done separately for the calms in each stability class.

2.3.7.3.2 Model Input Parameters The Off-Gas Stack has a height of 500 ft and is located on terrain that is approximately 265 ft C.D. PAVAN does not have the capability to account for the difference between station grade and stack grade, therefore, they were conservatively assumed to be equal resulting in a stack input height of 152.4 m. For this elevated Off-Gas Stack scenario, PAVAN requires input of terrain data. The highest terrain value within a given directional sector between the Station and the EAB was assigned to the EAB receptor in that given direction. The LPZ terrain heights were analogously assigned. These terrain heights are provided in the following table.

HIGHEST INTERVENING TERRAIN BETWEEN SITE AND EAB, AND LPZ (Meters Above Off-Gas Stack Grade)

DOWNWIND EAB LPZ DOWNWIND EAB LPZ DIRECTION (823 m) (7300 m) DIRECTION (823 m) (7300 m)

N 0 110 S 31 55 NNE 0 85 SSW 31 61 NE 0 85 SW 18 128 ENE 0 67 WSW 12 104 E 0 48 W 24 73 ESE 0 67 WNW 31 98 SE 0 43 NW 31 104 SSE 0 43 NNW 24 85 The units 2 and 3 Reactor Building Stacks have heights of 189 ft above station grade, however since they do not qualify as elevated releases per Regulatory Guide 1.145, PAVAN requires that each of these stack heights be assigned an input value of 10 m. For this CHAPTER 02 2.3-20 REV. 25, APRIL 2015

PBAPS UFSAR 2.3.7.4.1 ARCON96 Model Analysis Since the Units 2 and 3 Reactor Building Stacks are not 2.5 times the height of the adjacent structures, they do not qualify as an elevated release per RG 1.194, therefore, ARCON96 is executed in vent release mode. With an assumed zero (0) vertical exit velocity, vent releases are treated as ground-level releases by ARCON96. The basic model for a ground-level release is 2

1 y

/Q = exp -0.5 (2.3.7-6) y zU y

/Q relative concentration (concentration divided by release rate) [(Ci/m3)/(Ci/s)]

y, z diffusion coefficients (m)

U wind speed (m/s)

Y distance from the center of the plume (m)

This equation assumes that the release is continuous, constant, and of sufficient duration to establish a representative mean concentration. It also assumes that the material being released is reflected by the ground. Diffusion coefficients are typically determined from atmospheric stability and distance from the release point using empirical relationships. A diffusion coefficient parameterization from the NRC PAVAN and XOQDOQ (Reference 12) codes is used for y and z.

The diffusion coefficients have the general form

= a xb + c where x is the distance from the release point, in meters, and a, b, and c are parameters that are functions of stability. The parameters are defined for 3 distance ranges - 0 to 100 m, 100 to 1000 m, and greater than 1000 m. The parameter values may be found in the listing of Subroutine NSIGMAl in Appendix A of NUREG/CR-6331 Rev. 1.

Diffusion coefficient adjustments for wakes and low wind speeds are incorporated as follows:

To estimate diffusion in building wakes, composite wake diffusion coefficients, y and z, replace y and z. The composite wake diffusion coefficients are defined by CHAPTER 02 2.3-22 REV. 25, APRIL 2015

PBAPS UFSAR y = (y2 + y12 + y22) 1/2 (2.3.7-7) z = (z2 + z12 + z22) 1/2 (2.3.7-8) where y and z are the normal diffusion coefficients, y1 and z1 are the low wind speed corrections, and y2 and z2 are the building wake corrections. These corrections are described and evaluated in Ramsdall and Fosmire (Reference 13). The form of the low wind speed corrections is x -x y12 = 9.13x105 1 - 1 + exp (2.3.7-9) 1000U 1000U x -x Z12 = 6.67x102 1 - 1 + exp (2.3.7-10) 100U 100U where x is the distance from the release point to the receptor, in meters, and U is the wind speed in meters per second. It is appropriate to use the slant range distance for x because these corrections are made only when the release is assumed to be at the ground level and the receptor is assumed to be on the axis of the plume. The diffusion coefficients corrections that account for enhanced diffusion in the wake have a similar form. These corrections are x -x y22 = 5.24x10-2U-2A 1 - 1 + exp (2.3.7-11) 10A 10A CHAPTER 02 2.3-23 REV. 25, APRIL 2015

PBAPS UFSAR x -x z22 = 1.17x10-2U-2A 1 - 1 + exp (2.3.7-12) 10A 10A The value A is the cross-sectional area of the building.

An upper limit is placed on y as a conservative measure.

This limit is the standard deviation associated with a concentration uniformly distributed across a sector with width equal to the circumference of a circle with radius to the distance between the source and receptor. This value is 2X ymax = (2.3.7-13) 12 1.81x The Off-Gas Stack does qualify as an elevated release and is therefore executed as such in ARCON96. For elevated releases, the relative concentration is given by:

2 2 1 y he - hi

/Q = exp -0.5 exp -0.5 yzU y z where he is the effective stack height and hi is the height of the intake. Wake corrections are not made to diffusion coefficients used in calculating concentrations in elevated plumes. Effective stack height is determined from the actual stack height (hs), the difference in terrain elevation between the stack and intake locations (ts-ti), and stack downwash (hd) by he = hs + (ts-ti) + hd where the stack downwash is computed as wo hd = 4rs -1.5 CHAPTER 02 2.3-24 REV. 25, APRIL 2015

PBAPS UFSAR U(hs) and rs is the radius of the stack, wo is the vertical velocity of the effluent, and U(hs) is the wind speed at stack height. A release is considered elevated if the actual stack height is more than 2.5 times the height of structures in the immediate vicinity of the stack. Plume rise is not considered in calculating effective stack height in ARCON96. If consideration of plume rise is desired, the plume rise must be calculated manually and added to the release height before the release height is entered.

The sector-average model is used in calculating relative concentrations for elevated releases for averaging period longer than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The sector-average plume model for elevated releases may be derived in the same manner as the sector-average plume model for ground-level releases. It is 2

1 he - hi

/Q = exp -0.5 2WszU z Note that the use of the elevated plume models may lead to unrealistically low concentrations at control room intakes.

Near the base of stacks the highest concentrations are likely to occur during low wind speed conditions when there may be reversals in the wind direction. Since the Peach Bottom Off-Gas Stack is located close to the control room intake, RG 1.145 methodology is used in accordance with RG 1.194 to estimate potential control room intake concentrations during low wind speed conditions (See PAVAN modeling analysis in Section 2.3.7.4.2).

2.3.7.4.1.1 ARCON96 Meteorological Databases The 1984-1988 meteorological databases utilized in ARCON96 are shown in Section 2.3.7.2 and consist of hourly meteorological data observations of wind speed and direction, and delta temperature stability class.

The designation of 'calm' is made to all wind speed observations of less than 0.5 mph. The higher of the starting speeds of the Climatronics wind vane and anemometer equipment on each of the CHAPTER 02 2.3-25 REV. 25, APRIL 2015

PBAPS UFSAR towers (i.e., 0.50 mph) was used as the threshold for calm winds, per Regulatory Guide 1.145, Section 1.1.

2.3.7.4.1.2 ARCON96 Input Parameters The parameters that were input into the ARCON96 model for use in calculating the Control Room /Q are summarized in the following table:

ARCON96 INPUT UNIT 2 REACTOR UNIT 3 REACTOR OFF-GAS STACK PARAMETER BUILDING STACK BUILDING STACK Release Height (m) 152.4 57.6 57.6 Intake Height (m) 21 21 21 Horizontal Distance from 208.8 58.4 58.4 Intake to Stack (m)

Elevation Difference between 49.9 0 0 Stack Grade and Intake Grade (m)

Building Area (m2) 2583.6 2583.6 2583.6 Direction from Intake To 244 113 15 Stack (o)

Vertical Velocity (m/s) 0 0 0 Stack Flow (m3/s) 0 0 0 Stack Radius (m) 0 0 0 2.3.7.4.1.3 ARCON96 Control Room /Q Results A summary of the atmospheric diffusion estimates at the Control Room Intake for releases from the Off Gas Stack and Units 2 and 3 Reactor Building Stacks is shown in the following table.

ARCON96 Control Room /Q Results (sec/m3)

RELEASE INTAKE &

METEOROLOGICAL 0-2 hour 2-8 hour 8-24 hour 1-4 day 4-30 day SCENARIO

1. Off-Gas Stack to Control Room Intake:

Wind: Tower 2 320 Stability: Tower 2 316 - 33 1.00E-15 1.00E-15 1.00E-15 7.25E-15 5.92E-15

2. Unit 2 Reactor Building Stack to Control Room Intake:

Wind: Tower 1A 92 Stability: Tower 1A 89 - 33 1.17E-03 9.08E-04 4.14E-04 2.90E-04 2.26E-04 Wind: Tower 2 92 Stability: Tower 2 150 - 33 1.18E-03 8.55E-04 3.50E-04 2.36E-04 1.67E-04

3. Unit 3 Reactor Building Stack to Control Room Intake:

Wind: Tower 2 92 Stability: Tower 2 89 - 33 1.02E-03 5.02E-04 2.38E-04 1.62E-04 1.36E-04 Wind: Tower 2 75 Stability: Tower 2 150 - 33 1.18E-03 8.91E-04 4.00E-04 2.51E-04 1.98E-04 For the Units 2 and 3 stack release scenarios, the higher of the /Q values associated with the two meteorological databases analyzed is in larger text.

2.3.7.4.2 PAVAN Model Analysis CHAPTER 02 2.3-26 REV. 25, APRIL 2015

PBAPS UFSAR As mentioned in Section 2.3.7.4, a PAVAN modeling analysis was also performed to determine /Q values at the Control Room Intake for releases from the Off-Gas Stack. This analysis supplements the ARCON96 modeling analysis results for the 0-2 hour, 1-4 day, and 4-30 day /Q time intervals.

PAVAN was executed in stack release mode utilizing the equations outlined in Section 2.3.7.3.

2.3.7.4.2.1 PAVAN Meteorological Databases The meteorological tower database utilized in PAVAN for calculation of Control Room /Q for releases from the Off-Gas Stack is identified in Section 2.3.7.2. This database is the same as used by PAVAN for the EAB and LPZ /Q analyses outlined in Section 2.3.7.3.1. Page 1 of Table 2.3.29 shows the joint frequency distribution for the database.

2.3.7.4.2.2 PAVAN Input Parameters For the Off-Gas Stack to Control Room Intake scenario, PAVAN was executed with a stack-to-intake horizontal distance of 209 m.

For conservatism in modeling this scenario, the Off-Gas Stack was assumed to have the same grade elevation as the Station.

Review of this output was then performed in accordance with NRC RG 1.194 guidance to determine at which approximate distance the actual 0-2 hour maximum /Q is predicted to occur in each given downwind sector. Following this, a new set of PAVAN runs was executed for several distances ranging out to and exceeding the approximated distance. The initial predicted approximate distance to the maximum 0-2 hour /Q was 4000 m. Therefore, in all, the distances modeled to determine the actual maximum /Q are as follows: 209 (actual), 280, 300, 500, 750, 1000, 1500, 2000, 3000, 4000, 5000, and 6000 meters.

The Off-Gas Stack has a height of 500 ft and is located on terrain that is approximately 265 ft C.D. PAVAN does not have the capability to account for the difference between station grade and stack grade; therefore, in accordance with RG 1.194/

the release height is input as the difference between the actual release height and the intake height (500 ft - 69 ft = 431 ft =

131.4 m).

CHAPTER 02 2.3-27 REV. 25, APRIL 2015

PBAPS UFSAR PAVAN requires terrain data to be input for stack releases. The terrain data utilized for this calculation of /Q at the Control Room are the same as those used for the EAB and LPZ as shown in Section 2.3.7.3.2.

The Reactor Building height of 54.3 m and the calculated Reactor Building vertical cross-sectional area of 2584 m2 were utilized.

2.3.7.4.2.3 PAVAN Control Room /Q Results PAVAN Maximum /Q (sec/m3) Results Off-Gas Stack to Control Room Intake Modeled Horizontal Distance (m) from Stack to Control Room Intake 209 280 300 500 750 1000 1500 2000 3000 4000 5000 6000 Averaging (Actual Period Distance)

/Q (sec/m3) 3.31E- 3.31E- 3.31E- 3.31E- 2.60E- 2.32E- 2.18E- 2.05E- 1.95E- 1.87E- 1.86E- 1.75E-0-2 hr 06 06 06 06 06 06 06 06 06 06 06 06 2.28E- 1.68E- 2.18E- 3.93E- 3.02E- 2.55E- 2.26E- 2.34E- 2.65E- 2.74E- 2.72E- 2.62E-1-4 day 08 07 07 07 07 07 07 07 07 07 07 07 1.14E- 2.79E- 4.23E- 1.09E- 8.26E- 6.75E- 5.77E- 6.61E- 8.60E- 9.17E- 9.07E- 8.76E-4-30 day 09 08 08 07 08 08 08 08 08 08 08 08 2.3.7.4.3 Control Room /Q Results (In accordance with RG 1.194)

The following table shows the final Control Room /Q results in accordance with RG 1.194, which is derived based on the ARCON96 and PAVAN analysis /Q values.

Control Room X/Q Results (sec/m3)

RECEPTOR RELEASE POINT 0-2 hour 2-8 hour 8-24 hour 1-4 day 4-30 day Off-Gas Stack 3.31E-06 1.00E-15 1.00E-15 1.64E-08 4.54E-09 Control Unit 2 Reactor Room Building Stack 1.18E-03 9.08E-04 4.14E-04 2.90E-04 2.26E-04 Intake Unit 3 Reactor Building Stack 1.18E-03 8.91E-04 4.00E-04 2.51E-04 1.98E-04 CHAPTER 02 2.3-28 REV. 25, APRIL 2015

PBAPS UFSAR 2.3 METEOROLOGY REFERENCES

1. Spohn, H. R., et al, "Tornado Climatology," Monthly Weather Review, Washington, D. C., 90 (9), September, 1962, pp. 398-406.

2. Bennett, I., "Glaze: Its Meteorology & Climatology, Geographical Distribution & Ecomonic Effects," Environmental Protection Research Division Technical Report EP-105, Quartermaster Research Division Technical Report EP-105, Quartermaster Research & Engineering Command, Natick, Mass.,

March, 1959, p 217.

3. Kimble, George H. T., Our American Weather. N. Y., McGraw Hill, 1955.

4. Singer, I. and Smith, M., "Relation of Gustiness to Other Meteorological Parameters," Journal of Meteorology, Vol. 10, No. 2, April, 1953.

5. Slade, D. H., Meteorology and Atomic Energy 1968, (TID-24190) U.S. Atomic Energy Commission Division of Technical Information, July, 1968, p 101.

6. Smith, M. E. (ed.), Recommended Guide for the Prediction of the Dispersion of Airborne Effluents, American Society of Mechanical Engineers, New York, 1968, p 85.

7. Regulatory Guide 1.23 (Safety Guide 23) Rev. 1, Onsite Meteorological Programs; U.S. Nuclear Regulatory Commission; USNRC Office of Standards Development; Washington, D.C.; 2007.

8. Atmospheric Dispersion Code System for Evaluating Accidental Radioactivity Releases from Nuclear Power Stations; PAVAN, Version 2; Oak Ridge National Laboratory; U.S. Nuclear Regulatory Commission; December 1997.

9. Regulatory Guide 1.145; Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants (Revision 1); U.S. Nuclear Regulatory Commission; November 1982.

10. Atmospheric Relative Concentrations in Building Wakes; NUREG/CR-6331, PNNL-10521, Rev. 1; prepared by J.V.

CHAPTER 02 2.3-29 REV. 25, APRIL 2015

PBAPS UFSAR Ramsdell, Jr., C. A. Simmons, Pacific Northwest National Laboratory; prepared for U.S. Nuclear Regulatory Commission; May 1997 (Errata, July 1997).

11. Regulatory Guide 1.194; Atmospheric Relative Concentrations for Control Room Radiological Habitability Assessments at Nuclear Power Plants; U.S. Nuclear Regulatory Commission; June 2003.

12. XOQDOQ: Computer Program for the Meteorological Evaluation of Routine Releases at Nuclear Power Stations; NUREG/CR-2919; J. F. Sagendorf, J. T. Goll, and W. F. Sandusky, U.S.

Nuclear Regulatory Commission; Washington, D.C; 1982.

13. Atmospheric Dispersion Estimates in the Vicinity of Buildings; J. V. Ramsdell and C. J. Fosmire, Pacific Northwest Laboratory; 1995.

CHAPTER 02 2.3-30 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.3.1 ELEVATION OF PEACH BOTTOM WEATHER INSTRUMENTS (a)

WEATHER STATION NO. 1 WEATHER STATION NO. 2 Weather Tower No. 1 Hill Pole Microwave Tower River Tower Grade El 119 El 261 El 367 El 109 Wind Instruments Location No.

W1 El 153 (34', 30') (b)

W2 El 211 (92', 100')

W3 El 302 (41', 40')

W4 El 443 (76', 75')

W5 El 518 (151', 150') (c)

W6 El 688 (321', 320')

W7 El 164 (55', 50')

Thermohms T1 El 152 (33', 30')

T2 El 208 (89', 100')

T3 El 299 (38', 40')

T4 (d)

T5 El 443 (76', 75')

T6 El 513 (146', 150')

T7 El 683 (316', 320')

T8 (d)

(a)All elevations refer to mean sea level (MSL).

(b)The first figure in parenthesis after the elevation above MSL refers to the actual height of the sensor above grade or above the normal Pond Elevation in the case of the River Tower. The second figure in the parenthesis refers to the nominal height of the sensor above grade.

(c)This is a bivane. All other wind instruments are aerovanes.

(d)This is a constant reference temperature (40 F).

CHAPTER 02 2.3-31 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.1-A ELEVATION OF PEACH BOTTOM WEATHER INSTRUMENTS (a) 1983 SYSTEM UPGRADE WEATHER STATION NO. 1 WEATHER STATION NO. 2 Weather Tower No. 1(f) Hill Pole Microwave Tower River Tower Grade El 119 El 261 El 367 El 109 Location No.

Wind Instruments W1 El 153 (34')

W2 El 211 (92')

W3 El 294 (33')

W4 El 400 (33')

W5 El 443 (76')

W6 El 688 (321')

W6A El 697 (330') c W7 El 154 (45')

RTD Temperature Sensors T1 El 152 (33')

T1 El 152 (33') d T2 El 208 (89')

T3 (e)

T4 (e)

T5 El 400 (33')

T5 El 400 (33') d T6 El 517 (150')

T7 El 683 (316')

T8 (e)

Precipitation P1 El 124' (5')

P2 El 372 (5')

(a) All elevations refer to mean sea level (MSL).

(b) The first figure in parenthesis after the elevation above MSL refers to the actual height of the sensor above grade or above the normal Pond Elevation in the case of the River Tower.

(c) This is a Bendix Aerovane. All other instruments are Climatronics.

(d) This is a dew point sensor.

(e) Removed from service during upgrade.

(f) Removed from service in April 1992.

TABLE 2.3.2 CHAPTER 02 2.3-32 REV. 21, APRIL 2007

PBAPS UFSAR SAMPLE WEATHER DATA LISTINGS WEATHER STATION NO. 1(a)

Location Peach Bottom 1 Date 4-30-69 Wind 30 FT 100 FT Hill Bivane Gust Temperature ( F)

Hour DIR SP DIR SP DIR SP EL AZ S L 30 FT 100-30 H-30 D S PCPN PRESS RH 1 295 4 315 8 295 5 -0 -0 -0 2 50.0 0.0 -.6 0.00 -0 0 .06 0.00 96 2 305 8 330 11 285 7 -0 -0 -0 2 50.0 -.2 -.8 0.00 -0 0 .04 0.00 96 3 315 7 330 10 275 7 -0 -0 -0 2 48.0 -.2 -.8 0.00 -0 0 0.00 0.00 96 4 310 6 330 7 255 7 -0 -0 -0 2 49.0 0.0 -.7 0.00 -0 0 0.00 0.00 87 5 325 7 340 11 265 5 -0 -0 -0 2 47.3 -.1 -.7 0.00 -0 0 0.00 0.00 83 6 325 6 335 9 305 7 -0 -0 -0 2 47.8 -.2 -.7 0.00 -0 0 0.00 0.00 82 7 325 6 345 10 300 7 -0 -0 -0 2 47.8 -.2 -.7 0.00 -0 0 0.00 0.00 82 8 330 7 345 10 305 6 -0 -0 -0 2 46.8 -.2 -.8 0.00 -0 0 0.00 0.00 80 9 345 8 360 12 315 8 -0 -0 -0 2 47.0 -.6 -.6 0.00 -0 0 0.00 0.00 81 10 355 9 360 12 315 6 -0 -0 -0 2 48.5 -.8 -.4 0.00 -0 0 .04 0.00 72 11 355 9 360 11 315 8 -0 -0 -0 2 49.5 -.7 -.6 0.00 -0 0 0.00 0.00 70 12 360 8 10 8 315 6 -0 -0 -0 2 51.0 -.8 .3 0.00 -0 0 0.00 0.00 68 13 355 7 5 9 315 10 -0 -0 -0 2 54.0 -.8 -.2 0.00 -0 0 0.00 0.00 65 14 25 6 5 8 330 11 -0 -0 -0 2 54.3 -.7 1.0 0.00 -0 0 0.00 0.00 62 15 30 6 35 8 335 11 -0 -0 -0 2 56.0 -.7 .7 0.00 -0 0 0.00 0.00 59 16 25 5 25 7 335 11 -0 -0 -0 2 55.0 -.7 .6 0.00 -0 0 0.00 0.00 55 17 25 2 30 2 335 11 -0 -0 -0 2 55.6 -.6 .4 0.00 -0 0 0.00 0.00 54 18 20 1 20 1 335 10 -0 -0 -0 5 56.8 -.5 0.0 0.00 -0 0 0.00 0.00 54 19 20 2 20 2 355 10 -0 -0 -0 5 57.8 0.0 .1 0.00 -0 0 0.00 0.00 58 20 275 2 285 1 355 9 -0 -0 -0 5 52.7 2.4 1.6 0.00 -0 0 0.00 0.00 94 21 280 3 275 0 355 10 -0 -0 -0 5 49.7 3.6 2.0 0.00 -0 0 0.00 0.00 96 22 275 3 275 3 360 9 -0 -0 -0 5 48.0 3.0 .8 0.00 -0 0 0.00 0.00 96 23 280 2 265 4 360 5 -0 -0 -0 5 46.0 2.6 .2 0.00 -0 0 0.00 0.00 96 24 280 3 265 4 355 3 -0 -0 -0 5 45.0 1.4 -.7 0.00 -0 0 0.00 0.00 96 LISTING OF THE DATA FROM PEACH BOTTOM WEATHER STATION NO. 1(a)

From left to right: Hour of the day.

Nominal 30-ft level Aerovane, wind direction ( ) and speed (mi/hr) (at Location W1, El +153 MSL)

Nominal 100-ft level Aerovane, " " " " " (at Location W2, El +211 MSL)

Hill Aerovane, River Tower, " " " " " (at Location We, El +302 MSL)

Bivane Elevation and Azimuth (not used at this weather station)

Gustiness Classification(b) S (not used)

L - Turbulence at nominal 100-ft level Temperature ( F) - nominal 30-ft level (at Location T1, El 152 MSL)

Temperature Difference - T100-T30 ( F)

Temperature Difference - T -T30 ( F)

Temperature - not used Direction and Speed - not used Precipitation - (in)

Pressure - not used at this station Relative Humidity (%)

(a)

See Table 2.3.1 for exact instrument locations.

(b)

See Table 2.3.10 for description of Turbulence classes.

TABLE 2.3.3 SAMPLE WEATHER DATA LISTINGS CHAPTER 02 2.3-33 REV. 21, APRIL 2007

PBAPS UFSAR WEATHER STATION NO. 2(a)

Location Peach Bottom 2 Date 4-30-69 Wind 75 FT 320 FT SAT Bivane Gust Temperature ( F)

Hour DIR SP DIR SP DIR SP EL AZ S L 75 FT 150-75 320-75 D S PCPN PRES RH 1 320 11 15 17 315 12 23 20 -0 2 49.4 -.2 -.6 0.00 -0 0 .05 29.53 100 2 345 13 20 19 345 17 14 22 -0 2 49.0 -.2 -.8 0.00 -0 0 0 00 29.52 100 3 340 13 25 18 340 15 13 18 -0 2 47.3 -.2 -1.0 0.00 -0 0 0 00 29.53 94 4 345 13 25 17 340 14 13 25 -0 2 47.5 -.2 -.9 0.00 -0 0 0 00 29.53 89 5 350 12 35 16 345 13 13 30 -0 2 47.0 -.2 -1.0 0.00 -0 0 0 00 29.56 87 6 345 13 35 15 355 15 14 30 -0 2 46.5 -.2 -1.0 0.00 -0 0 0 00 29.59 88 7 350 12 40 15 350 14 16 22 -0 2 46.0 -.3 -1.1 0.00 -0 0 0 00 29.62 88 8 345 12 35 13 350 14 17 58 -0 2 46.2 -.3 -1.1 0.00 -0 0 0 00 29.62 89 9 355 10 45 14 355 11 28 50 -0 2 46.8 -.2 -1.4 0.00 -0 0 0 00 29.65 90 10 5 9 45 12 360 13 38 50 -0 2 48.2 -.6 -1.7 0.00 -0 0 0 00 29.67 84 11 10 9 45 10 360 11 26 42 -0 2 48.0 -.6 -1.6 0.00 -0 0 0 00 29.66 69 12 20 9 50 12 5 10 28 34 -0 2 50.0 -.6 -1.6 0.00 -0 0 0 00 29.66 68 13 20 9 55 11 360 10 23 30 -0 2 51.0 -.7 -1.8 0.00 -0 0 0 00 29.66 64 14 30 8 60 9 10 9 22 50 -0 2 53.2 -.8 -2.0 0.00 -0 0 0 00 29.65 63 15 30 9 70 10 40 8 30 20 -0 2 54.0 -.9 -1.8 0.00 -0 0 0 00 29.65 59 16 30 7 65 9 35 7 16 18 -0 2 55.0 -.9 -1.8 0.00 -0 0 0 00 29.64 60 17 35 5 80 5 30 5 14 15 -0 2 55.1 -.6 -1.6 0.00 -0 0 0 00 29.65 62 18 35 2 80 3 25 3 15 15 -0 5 55.2 -.5 -1.4 0.00 -0 0 0 00 29.65 64 19 25 4 70 6 25 3 6 5 -0 5 55.0 -.2 -.9 0.00 -0 0 0 00 29.67 70 20 355 0 70 4 330 1 1 3 -0 5 54.7 -.2 -.6 0.00 -0 0 0 00 29.68 82 21 35 1 70 2 300 1 1 2 -0 5 52.2 .2 .7 0.00 -0 0 0 00 29.69 94 22 290 2 170 0 305 1 4 7 -0 5 51.7 .6 .4 0.00 -0 0 0 00 29.71 99 23 295 3 170 0 285 1 4 7 -0 5 50.0 .8 1.6 0.00 -0 0 0 00 29.70 99 24 315 4 170 0 285 1 2 8 -0 5 49.0 1.0 2.2 0.00 -0 0 0 00 29.70 99 LISTING OF THE DATA FROM PEACH BOTTOM WEATHER STATION NO. 2(a)

From left to right: Hour of the day.

Nominal 75-ft level Aerovane, wind direction ( ) and speed (mi/hr) (at Location W4, El 443 MSL)

Nominal 320-ft level Aerovane, " " " " (at Location W6, El 688 MSL)

Satellite Aerovane, River Tower " " " " (at Location W7, El 164 MSL)

Bivane Elevation and Azimuth ( ) - nominal 150-ft level (at Location W5, El 518 MSL)

Gustiness Classification(b) S (not used)

L - Turbulence at nominal 320-ft level Temperature ( F) - nominal 75-ft level (at Location T5, El 443 MSL)

Temperature Difference - T150-T75 ( F)

T320-T75 ( F)

Temperature - not used Direction and Speed - not used Precipitation - (in)

Pressure - (in Hg)

Relative Humidity (%)

(a)

See Table 2.3.1 for exact instrument locations.

(b)

See Table 2.3.10 for description of Turbulence classes.

CHAPTER 02 2.3-34 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.4 DISTRIBUTION OF HOURLY TEMPERATURES PEACH BOTTOM WEATHER STATION NO. 1 LOCATION T1 (NOMINAL 30-FT LEVEL, EL 152 FT MSL)

(Percent)

Period: August, 1967-July, 1969 Temperature Classes (F) 0 +10 +20 +30 +40 +50 +60 +70 +80 +90 to to to to to to to to to to Month <0 +10 +20 +30 +40 +50 +60 +70 +80 +90 +100 >100 Jan 0 2 22 38 29 8 1 0 0 0 0 0 Feb 0 1 5 16 64 13 1 0 0 0 0 0 Mar 0 0 1 20 42 22 8 4 2 1 0 0 Apr 0 0 0 <1 8 27 39 20 5 1 0 0 May 0 0 0 0 1 11 42 30 12 3 1 0 Jun 0 0 0 0 0 <1 10 37 39 13 1 0 Jul 0 0 0 0 0 0 2 14 64 18 2 0 Aug 0 0 0 0 0 0 7 27 42 22 2 0 Sep 0 0 0 0 0 2 20 39 34 5 0 0 Oct 0 0 0 0 9 15 34 36 4 2 <1 0 Nov 0 0 <1 3 28 43 22 3 1 0 0 0 Dec 0 1 5 22 46 22 4 0 0 0 0 0 Annual 0 <1 3 8 20 13 16 18 17 5 <1 0 CHAPTER 02 2.3-35 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.5 DISTRIBUTION OF HOURLY TEMPERATURES PEACH BOTTOM WEATHER STATION NO. 2 LOCATION T5 (NOMINAL 75-FT LEVEL, EL 443 FT MSL)

(Percent)

Period: August, 1967-July, 1969 Temperature Classes (F) 0 +10 +20 +30 +40 +50 +60 +70 +80 +90 to to to to to to to to to to Month <0 +10 +20 +30 +40 +50 +60 +70 +80 +90 +100 >100 Jan 0 3 25 34 22 15 1 0 0 0 0 0 Feb 0 1 10 27 56 6 0 0 0 0 0 0 Mar 0 0 <1 12 34 31 16 6 1 0 0 0 Apr 0 0 0 <1 4 31 40 20 4 1 0 0 May 0 0 0 0 7 28 31 24 8 2 <1 0 Jun 0 0 0 0 0 0 8 38 47 13 <1 0 Jul 0 0 0 0 0 0 0 27 54 18 1 0 Aug 0 0 0 0 0 0 1 49 42 5 3 0 Sep 0 0 0 0 0 1 10 49 38 2 0 0 Oct 0 0 0 0 5 28 36 26 5 <1 0 0 Nov 0 0 0 31 22 25 20 2 0 0 0 0 Dec 0 <1 6 27 42 20 5 0 0 0 0 0 Annual 0 <1 4 11 16 16 14 20 16 3 <1 0 CHAPTER 02 2.3-36 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.6 PRECIPITATION PEACH BOTTOM WEATHER STATION NO. 1 (Inches, water)

Period: August, 1967-July, 1969 Month 1967 1968 1969 Range of Maximum Hourly Rate Jan .33 .75 .11 to .20 Feb .60 .64 .01 to .10 Mar .06 1.08 .21 to .30 Apr 2.72 2.75 .81 to .90 May 5.11 1.23 .31 to .40 Jun 2.72 2.82 .81 to .90 Jul 1.01 3.95 >1.00 Aug 6.91 3.46 .91 to 1.00 Sep .67 4.15 .81 to .90 Oct 1.41 3.14 .41 to .50 Nov 2.32 1.37 .21 to .30 Dec 4.43 2.26 .31 to .40 Annual Total 26.93 CHAPTER 02 2.3-37 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.7 PRECIPITATION PEACH BOTTOM WEATHER STATION NO. 2 (Inches, water)

Period: August, 1967-July, 1969 Month 1967 1968 1969 Range of Maximum Hourly Rate Jan * .30 .64 .11 to .20 Feb * .45 .70 .01 to .10 Mar

• 2.89 .82 .21 to .30 Apr

• 1.60 3.12 .51 to .60 May

• 5.17 1.41 .31 to .40 Jun

• 3.44 3.02 .71 to .80 Jul * .44 6.94 .81 to .90 Aug

• 3.46 .91 to 1.00 Sep

• 4.66 .71 to .80 Oct

• 1.56 .31 to .40 Nov

• 4.66 .71 to .80 Dec 1.25 2.26 .11 to .20 Annual Total 30.89

• No precipitation recorded CHAPTER 02 2.3-38 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.8 DISTRIBUTION OF PEAK WINDS PHILADELPHIA INTERNATIONAL AIRPORT (25-yr record)

Fastest Mile Month Speed (mph) Direction Jan 61 NE Feb 59 NW Mar 56 NW Apr 59 SW May 56 SW June 73 SW July 67 E Sep 49 NE Oct 66 SW Nov 60 SW Dec 47 NW Fastest Mile Observed in Area: 88 mph, North, July, 1931 Estimated Peak Hourly Value: 70 mph CHAPTER 02 2.3-39 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.9 HIGHEST MEAN HOURLY WIND SPEED AND ESTIMATED PEAK GUST PEACH BOTTOM WEATHER STATION NO. 2 LOCATION W6 (NOMINAL 320-FT LEVEL, EL 688 FT MSL)

Period: August, 1967-July, 1969 Maximum Hourly Estimated Wind Mean Speed Peak Direction Year Month (mph) (mph) ()

1967 Aug 22 36 200 Sep 35 55 170 Oct 31 49 240 Nov 33 53 305 Dec 34 54 335 1968 Jan 37 56 300 Feb 37 57 295 Mar 40 60 325 Apr 30 48 305 May 29 44 090 Jun 26 44 260 Jul 22 33 345 Aug 26 43 240 Sep 24 39 125 Oct 28 44 235 Nov 28 42 200 Dec 41 64 295 1969 Jan 28 44 295 Feb 35 53 345 Mar 26 39 325 Apr 27 40 180 May 26 39 280 Jun 27 42 175 Jul 21 32 065 CHAPTER 02 2.3-40 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.10 TURBULENCE CLASSIFICATION Brookhaven National Smith-Singer Pasquill Laboratory Classification Classification Classification* Description of Wind Trace I - A Fluctuations of the wind direction dur-ing the course of 1 hr exceed 90 deg.

II B & C B1 Fluctuations are confined to a lower limit of 15 deg and an upper limit of 45 deg.

III A B2 Trace is similar to I and II but the upper and lower limits are 90 and 45 deg.

IV D C The lower limit of the fluctuations is 15 deg, and no upper limit is imposed.

The case is distinguished by an unbroken solid core, through which a straight line can be drawn for the entire hour, without touching "open space" on the chart.

V F & G D The trace approximates a line, and short-term fluctuations do not exceed 15 deg.

Direction may vary gradually over a wide angle during the hour.

• Source: Singer, I. and Smith, M., "Relation of Gustiness to other Meteorological Parameters," Journal of Meteorology, Vol. 10, No. 2, April, 1953.

CHAPTER 02 2.3-41 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.2.11 MANUFACTURING ESTABLISHMENTS AND EMPLOYMENT IN THE FIVE-COUNTY AREA SURROUNDING THE PEACH BOTTOM SITE Type of Product Number of Total Number Number of Units Not Manufactured Employees Reported of Units Reported Reporting Employees Ordnance and Accessories

• 4 4 Food and Kindred Products 11,609 256 -

Tobacco Manufacturers 1,741 36 -

Textile Mill Products 6,812 55 -

Apparel and Related Products 13,063 133 -

Lumber and Wood Products 1,394 91 11 Furniture and Fixtures 4,736 61 5 Paper and Allied Products 5,606 56 1 Printing and Publishing 6,608 139 -

Chemicals and Allied Products 3,063 66 16 Petroleum and Coal Products 294 7 -

Leather and Leather Products 5,262 39 -

Rubber and Plastic Products 1,495 14 3 Stone, Clay, and Glass Products 5,585 86 -

Primary Metal Industries 12,551 62 1 Fabricated Metal Products 10,978 151 -

Machinery, Except Electrical 16,376 208 -

Electrical Machinery 15,247 47 2 Transportation Equipment 2,381 36 13 Instruments and Related Products

• 6 6 Not Separately Classified - 102 -

Total Manufacturing 146,928 1,655 -

• Figures not published to avoid disclosure of operations of reporting units.

Source: County Business Patterns, 1967 - U.S. Dept of Commerce.

CHAPTER 02 2.3-42 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.12 PERCENTAGE FREQUENCY OF TURBULENCE CLASSES PEACH BOTTOM WEATHER STATION NO. 2 LOCATION W6 (NOMINAL 320-FT LEVEL, EL 688 FT MSL)

Period: August, 1967-July 1969 Class Month I II III IV V Jan 1 55 2 12 30 Feb <1 50 2 20 28 Mar 1 48 2 22 27 Apr 1 56 4 10 29 May <1 54 4 10 32 Jun 1 61 4 5 29 Jul 2 58 4 3 33 Aug 1 48 4 7 40 Sep 2 43 2 11 42 Oct 1 45 2 10 42 Nov 1 41 1 11 46 Dec 1 53 2 14 30 Annual 1 51 3 12 33 CHAPTER 02 2.3-43 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.13 RELATION BETWEEN LAPSE RATES AND TURBULENCE CLASSES (Percent)

Period: August, 1967-July, 1969 Weather Station No. 1 Temperature Difference T100 - T30 (F)

Turbu- -1.6 -0.4 0.6 1.6 2.6 3.6 lence to to to to to to Class <-1.7 -0.5 0.5 1.5 2.5 3.4 4.5 >4.6 I 0.1 0.5 1.0 0.1 0.0 0.0 0.0 0.0 II 1.5 10.5 29.1 5.4 3.0 1.5 1.3 0.7 III 0.4 0.9 1.5 0.3 0.2 <0.1 0.0 <0.1 IV 0.2 1.7 4.7 0.5 0.3 0.3 0.2 <0.1 V 0.1 1.0 11.3 9.6 6.1 3.3 1.6 1.1 Weather Station No. 2 Temperature Difference T320 - T75 (F)

I 0.3 0.5 0.1 0.1 0.0 <0.1 0.0 0.0 II 8.2 34.1 4.7 1.2 0.5 0.2 0.1 0.1 III 0.7 1.3 0.2 0.1 0.1 <0.1 0.0 0.0 IV 0.3 10.7 2.7 0.4 0.2 <0.1 <0.1 0.0 V 0.1 6.8 9.4 4.7 3.6 2.8 2.3 3.5 CHAPTER 02 2.3-44 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.14 ANNUAL DISTRIBUTION OF WIND BY TURBULENCE CLASS AND DIRECTION PEACH BOTTOM WEATHER STATION NO. 1 LOCATION W2 (NOMINAL 100-FT LEVEL, EL 211 FT MSL)

(Percent of All Hours During Which Data Are Available)

Period: August, 1967-July, 1969 Missing Hours: 4,622 Turbulence Class Wind All Direction I II III IV V Classes 10 <0.1 0.9 0.1 <0.1 0.4 1.4 20 <0.1 0.9 <0.1 0.1 0.2 1.2 30 <0.1 0.6 0.1 <0.1 0.4 1.2 40 0.1 0.5 <0.1 <0.1 0.5 1.2 50 <0.1 0.4 <0.1 <0.1 0.2 0.7 60 <0.1 0.5 <0.1 0.1 0.2 0.9 70 <0.1 0.6 <0.1 <0.1 0.3 1.0 80 <0.1 0.5 <0.1 0.1 0.3 1.0 90 <0.1 0.7 0.1 0.0 0.3 1.1 100 <0.1 0.9 0.1 <0.1 0.7 1.7 110 0.1 1.2 <0.1 <0.1 0.6 1.9 120 0.2 2.9 0.1 0.1 1.2 4.5 130 0.4 4.0 0.5 0.5 1.6 6.9 140 0.1 2.0 0.2 0.1 1.0 3.4 150 0.2 2.2 0.3 <0.1 1.5 4.2 160 0.1 1.3 0.1 <0.1 1.7 3.2 170 <0.1 1.0 0.1 0.1 1.0 2.2 180 0.1 0.8 0.1 0.2 1.0 2.2 190 <0.1 0.3 <0.1 <0.1 0.9 1.3 200 0.0 0.1 0.0 0.0 0.4 0.5 210 0.1 0.1 <0.1 0.0 0.9 1.0 220 0.1 0.2 <0.1 <0.1 1.5 1.9 230 0.0 0.4 <0.1 <0.1 0.8 1.2 240 0.1 1.0 0.1 0.1 1.5 2.7 250 0.1 1.8 0.1 0.3 2.2 4.5 CHAPTER 02 2.3-45 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.14 (Continued)

Turbulence Class Wind All Direction I II III IV V Classes 260 <0.1 1.8 0.1 0.4 1.8 4.0 270 0.2 2.3 0.1 0.4 2.2 5.3 280 0.1 3.7 0.3 0.4 2.0 6.5 290 <0.1 3.4 0.1 1.5 1.2 6.1 300 0.1 2.9 0.2 0.9 1.1 5.2 310 0.1 2.9 0.1 0.9 0.9 4.9 320 <0.1 2.5 <0.1 0.4 0.4 3.4 330 <0.1 2.7 0.2 0.6 0.6 4.2 340 <0.1 2.3 0.1 0.2 0.5 3.1 350 <0.1 1.8 0.1 0.1 0.3 2.3 360 <0.1 1.3 0.1 0.1 0.5 2.0 All 2.5 53.4 3.5 7.7 32.9 100.0 CHAPTER 02 2.3-46 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.15 ANNUAL DISTRIBUTION OF WIND BY TURBULENCE CLASS AND DIRECTION PEACH BOTTOM WEATHER STATION NO. 2 LOCATION W6 (NOMINAL 320-FT LEVEL, EL 688 FT MSL)

(Percent of All Hours During Which Data Are Available)

Period: August, 1967-July, 1969 Missing Hours: 2,024 Turbulence Class Wind All Direction I II III IV V Classes 10 <0.1 1.4 0.1 0.2 0.7 2.3 20 0.0 1.2 0.1 0.1 0.5 1.9 30 <0.1 1.0 0.1 0.1 0.5 1.8 40 <0.1 1.0 <0.1 0.1 0.3 1.5 50 <0.1 0.7 <0.1 0.1 0.5 1.3 60 <0.1 0.8 0.1 0.1 0.5 1.5 70 <0.1 0.8 0.1 0.1 0.4 1.4 80 <0.1 0.8 0.1 <0.1 0.3 1.3 90 <0.1 0.9 0.1 0.1 0.4 1.6 100 <0.1 0.9 <0.1 0.1 0.5 1.5 110 <0.1 1.2 0.1 <0.1 0.6 1.9 120 <0.1 1.5 0.1 0.1 0.8 2.5 130 <0.1 1.6 0.1 0.1 0.7 2.5 140 0.0 1.1 <0.1 0.2 0.9 2.3 150 <0.1 1.5 <0.1 0.2 1.1 2.8 160 <0.1 1.5 0.1 0.1 1.1 2.8 170 0.0 1.5 0.1 0.3 1.0 2.9 180 0.1 2.4 0.1 0.6 1.1 4.3 190 <0.1 2.0 <0.1 0.4 1.3 3.8 200 <0.1 1.3 <0.1 0.4 0.9 2.7 210 <0.1 1.2 0.1 0.2 1.1 2.6 220 <0.1 0.9 0.1 0.1 0.8 2.0 230 <0.1 0.9 0.1 0.2 0.9 2.0 240 0.1 0.9 0.1 0.1 1.1 2.3 250 <0.1 1.0 0.1 0.2 1.1 2.4 CHAPTER 02 2.3-47 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.15 (Continued)

Turbulence Class Wind All Direction I II III IV V Classes 260 <0.1 0.9 <0.1 0.2 1.1 2.2 270 <0.1 1.3 0.1 0.4 1.5 3.3 280 <0.1 1.8 0.1 0.5 1.2 3.5 290 0.0 1.8 <0.1 0.7 1.4 4.0 300 <0.1 2.3 0.1 0.9 1.5 4.8 310 <0.1 2.4 0.1 1.2 1.5 5.3 320 <0.1 2.3 0.1 0.9 1.5 4.8 330 <0.1 3.0 0.2 1.2 1.5 6.0 340 <0.1 2.4 0.2 0.8 1.1 4.6 350 <0.1 1.6 0.1 0.8 0.9 2.9 360 <0.1 1.3 0.1 0.4 0.9 2.7 All 0.9 51.2 2.8 11.7 33.4 100.0 CHAPTER 02 2.3-48 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.16 MEAN ANNUAL WIND SPEEDS AT VARIOUS LEVELS PEACH BOTTOM WEATHER STATIONS NOS. 1 AND 2 (MPH)

Period: August, 1967 - July, 1969 Hill Pole River Tower Nominal Nominal Nominal Nominal Nominal Nominal Turbulence 30-Ft 100-Ft 40-Ft 75-Ft 320-Ft 50-Ft Class El 153 El 211 El 302 El 443 El 688 El 164 I 1 1 4 2 2 2 II 4 6 6 7 11 8 III 2 3 5 4 4 4 IV 8 11 9 11 18 11 V 1 1 1 4 8 2 All 3 4 4 6 11 6 CHAPTER 02 2.3-49 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.17 PERCENTAGE FREQUENCY OF WIND SPEEDS BY TURBULENCE CLASSES LOCATION W1 (NOMINAL 30-FT LEVEL, EL 152 MSL)

Period: August, 1967-July, 1969 CLASS Speed (mph) I II III IV V All

<1 1.79 13.85 1.48 0.39 22.55 40.05 2 0.50 8.39 0.59 0.52 5.39 15.38 3 0.29 6.33 0.43 0.54 2.41 10.00 4 0.09 5.48 0.28 0.51 1.59 7.94 5 0.02 4.10 0.20 0.63 0.33 5.27 6 0.01 3.12 0.16 0.62 0.15 4.07 7 0.01 3.50 0.08 0.93 0.08 4.60 8 0.00 2.35 0.04 0.61 0.02 3.02 9 0.01 1.95 0.03 0.73 0.01 2.73 10 0.01 1.28 0.04 0.78 0.00 2.10 11 0.00 1.14 0.01 0.65 0.01 1.81 12 0.00 0.55 0.01 0.27 0.03 0.85 13 0.00 0.50 0.00 0.43 0.01 0.94 14 0.00 0.10 0.00 0.17 0.00 0.27 CHAPTER 02 2.3-50 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.17 (Continued)

CLASS Speed (mph) I II III IV V All 15 0.00 0.11 0.00 0.25 0.00 0.36 16 0.00 0.06 0.00 0.16 0.00 0.22 17 0.00 0.04 0.00 0.17 0.00 0.20 18 0.00 0.01 0.00 0.05 0.00 0.06 19+ 0.00 0.03 0.00 0.09 0.00 0.12 SUM 2.70 52.80 3.30 8.50 32.50 100.00 CHAPTER 02 2.3-51 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.18 PERCENTAGE FREQUENCY OF WIND SPEEDS BY TURBULENCE CLASSES LOCATION W2 (NOMINAL 100-FT LEVEL, EL 211 FT MSL)

Period: August, 1967-July, 1969 CLASS Speed (mph) I II III IV V All 1 1.77 5.58 .58 .11 23.24 31.68 2 .60 5.75 .49 .05 3.43 10.33 3 .36 5.49 .59 .06 1.59 8.10 4 .14 5.92 .34 .18 1.37 7.95 5 .09 5.32 .39 .26 .61 6.67 6 .02 5.33 .16 .53 .56 6.59 7 0.00 4.29 .18 .62 .19 5.28 8 0.00 3.97 .12 .71 .14 4.94 9 0.00 2.67 .06 .67 .04 3.43 10 0.00 2.61 .04 .76 .02 3.43 11 0.00 2.00 .02 .62 .01 2.65 12 0.00 1.43 0.00 .67 0.00 2.10 13 0.00 1.32 .01 .75 .01 2.08 14 0.00 .71 .01 .45 0.00 1.16 CHAPTER 02 2.3-52 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.18 (Continued)

CLASS Speed (mph) I II III IV V All 15 0.00 .69 .01 .60 0.00 1.30 16 0.00 .35 0.00 .34 0.00 .69 17 0.00 .27 0.00 .30 0.00 .57 18 0.00 .11 0.00 .12 0.00 .23 19 0.00 .24 0.00 .58 0.00 .82 SUM 2.90 54.00 3.30 8.30 31.20 100.00 CHAPTER 02 2.3-53 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.19 PERCENTAGE FREQUENCY OF WIND SPEEDS BY TURBULENCE CLASSES LOCATION W3 (HILL POLE, EL 302 FT MSL)

Period: August, 1967-July, 1969 CLASS Speed (mph) I II III IV V All

<1 .72 5.63 .49 .10 19.29 26.21 2 .39 5.82 .37 .25 5.42 12.26 3 .33 5.53 .33 .34 2.76 9.29 4 .31 6.65 .39 .49 2.10 9.95 5 .27 5.47 .33 .68 .85 7.59 6 .21 5.12 .37 .74 .59 7.04 7 .17 4.65 .28 1.06 .28 6.43 8 .08 3.62 .27 .69 .12 4.79 9 .06 2.73 .14 .71 .08 3.71 10 .02 2.01 .08 .72 .06 2.90 11 .05 1.60 .07 .68 .04 2.43 12 .01 1.17 .03 .43 .03 1.66 13 .04 1.15 .05 .63 .01 1.87 14 .01 .68 .02 .31 0.00 1.03 CHAPTER 02 2.3-54 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.19 (Continued)

CLASS Speed (mph) I II III IV V All 15 .02 .68 .05 .33 0.00 1.07 16 .01 .33 .01 .21 0.00 .56 17 .01 .21 0.00 .17 0.00 .39 18 0.00 .14 0.00 .10 0.00 .24 19+ .01 .30 .02 .24 .01 .58 SUM 2.70 53.50 3.20 8.80 31.60 100.00 CHAPTER 02 2.3-55 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.20 PERCENTAGE FREQUENCY OF WIND SPEEDS BY TURBULENCE CLASSES LOCATION W4 (NOMINAL 75-FT LEVEL, EL 443 FT MSL)

Period: August, 1967-July, 1969 CLASS Speed (mph) I II III IV V All

<1 .48 3.45 .63 .15 9.13 13.84 2 .40 3.44 .56 .14 4.31 8.85 3 .12 3.92 .39 .16 3.58 8.18 4 .07 4.18 .36 .33 3.97 8.90 5 .03 4.03 .25 .43 2.67 7.41 6 .01 4.49 .24 .52 2.85 8.11 7 .02 4.79 .22 .68 2.10 7.82 8 .02 4.06 .12 .92 1.97 7.08 9 0.00 3.22 .09 .97 1.07 5.34 10 0.00 3.34 .05 .93 .77 5.10 11 .01 3.21 .04 1.18 .49 4.93 12 0.00 2.00 .02 .66 .29 2.97 13 0.00 2.22 .03 1.00 .11 3.36 14 0.00 .93 0.00 .46 .07 1.46 CHAPTER 02 2.3-56 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.20 (Continued)

CLASS Speed (mph) I II III IV V All 15 .01 1.53 .01 .90 .03 2.48 16 0.00 .68 0.00 .33 .01 1.01 17 0.00 .80 0.00 .44 0.00 1.24 18 0.00 .23 0.00 .16 0.00 .39 19+ 0.00 .68 0.00 .83 .01 1.52 SUM 1.10 51.20 3.00 11.10 33.40 100.00 CHAPTER 02 2.3-57 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.21 PERCENTAGE FREQUENCY OF WIND SPEEDS BY TURBULENCE CLASSES LOCATION W6 (NOMINAL 320-FT LEVEL, EL 688 FT MSL)

Period: August, 1967-July, 1969 CLASS Speed (mph) I II III IV V All

<1 .30 .45 .44 .02 2.11 3.32 2 .26 .90 .39 0.00 1.64 3.19 3 .19 1.05 .35 .01 1.52 3.13 4 .13 1.91 .38 .01 2.29 4.72 5 .03 2.12 .26 .03 1.98 4.42 6 .04 2.98 .23 .05 2.98 6.28 7 .02 3.08 .20 .02 2.34 5.66 8 .02 4.37 .26 .11 2.92 7.68 9 0.00 3.13 .09 .07 1.85 5.14 10 .01 3.82 .08 .17 2.43 6.52 11 0.00 3.48 .06 .29 2.13 5.96 12 0.00 3.87 .03 .40 2.15 6.45 13 0.00 3.36 .02 .66 1.70 5.74 14 0.00 2.67 .01 .70 1.61 4.99 15 0.00 2.85 0.00 .86 1.18 4.90 CHAPTER 02 2.3-58 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.21 (Continued)

CLASS Speed (mph) I II III IV V All 16 0.00 2.30 0.00 1.00 1.13 4.42 17 0.00 2.04 0.00 1.20 .59 3.82 18 0.00 1.28 0.00 1.01 .56 2.84 19+ 0.00 5.31 .02 4.84 .65 10.81 SUM 1.00 50.90 2.80 11.40 33.70 100.00 CHAPTER 02 2.3-59 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.22 PERCENTAGE FREQUENCY OF WIND SPEEDS BY TURBULENCE CLASSES LOCATION W7 (RIVER TOWER, EL 164 FT MSL)

Period: August, 1967-July, 1969 CLASS Speed (mph) I II III IV V All

<1 .64 8.72 1.15 1.22 12.17 23.90 2 .25 3.20 .42 .20 7.10 11.19 3 .12 2.97 .19 .16 3.46 6.90 4 .13 3.75 .29 .27 3.75 8.19 5 .03 3.31 .14 .39 2.04 5.92 6 .02 4.18 .23 .65 1.82 6.90 7 .01 4.29 .14 .67 .90 6.01 8 .03 4.11 .13 .74 .91 5.92 9 0.00 2.95 .07 .47 .39 3.89 10 .01 2.82 .02 .50 .31 3.66 11 0.00 2.59 .03 .56 .10 3.27 12 0.00 2.11 .01 .40 .11 2.64 13 0.00 2.19 .01 .52 .06 2.78 14 0.00 1.12 .02 .40 .01 1.56 CHAPTER 02 2.3-60 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.22 (Continued)

CLASS Speed (mph) I II III IV V All 15 0.00 1.39 0.00 .41 .01 1.82 16 0.00 .93 0.00 .19 .01 1.13 17 0.00 .94 0.00 .38 .02 1.34 18 0.00 .53 0.00 .14 0.00 .67 19+ 0.00 1.55 0.00 .77 0.00 2.31 SUM 1.20 53.60 2.80 9.00 33.10 100.00 CHAPTER 02 2.3-61 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.23 PERCENTAGE FREQUENCY OF LAPSE RATES PEACH BOTTOM WEATHER STATION NO. 1 Period: August, 1967-July, 1969 Lapse Rate Group (T100-T20) (F)

-1.6 -0.4 +0.6 +1.6 +2.6 +3.5 to to to to to to Month -1.7 -0.5 +0.5 +1.5 +2.5 +3.5 +4.5 +4.6 Jan 2 20 53 14 6 3 2 <1 Feb 1 19 45 14 9 6 4 2 Mar 1 24 40 24 7 3 1 <1 Apr 3 18 48 12 8 4 5 2 May <1 18 50 11 8 6 4 3 Jun <1 7 55 18 11 5 2 2 Jul 0 4 42 19 16 11 5 3 Aug 6 12 44 14 11 6 3 4 Sep 6 13 36 8 12 13 8 4 Oct 3 6 39 22 10 10 6 4 Nov 1 12 50 17 12 4 2 2 Dec 1 11 57 14 9 4 2 2 Annual 2 14 47 15 10 6 4 2 CHAPTER 02 2.3-62 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.24 PERCENTAGE FREQUENCY OF LAPSE RATES PEACH BOTTOM WEATHER STATION NO. 2 Period: August, 1967-July, 1969 Lapse Rate Group (T320-T75) (F)

-1.6 -0.4 +0.6 +1.6 +2.6 +3.5 to to to to to to Month -1.7 -0.5 +0.5 +1.5 +2.5 +3.5 +4.5 +4.6 Jan 4 65 20 4 1 2 2 2 Feb 12 64 14 4 2 2 <1 2 Mar 12 52 18 8 3 2 2 3 Apr 15 52 16 6 4 2 1 4 May 20 45 14 7 5 2 2 5 Jun* 30 40 16 5 5 2 1 1 Jul* 26 44 10 7 7 4 2 <1 Aug* 5 64 18 6 2 3 2 0 Sep 14 39 14 8 8 6 6 5 Oct 12 42 18 9 8 5 4 2 Nov 13 40 18 6 6 5 4 8 Dec 4 65 16 6 3 3 1 2 Annual 14 51 16 6 4 3 2 4

• Only one year's data included.

CHAPTER 02 2.3-63 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.25 STEADINESS FACTORS PEACH BOTTOM WEATHER STATION NO. 1 NOMINAL 100-FT LEVEL (EL 211 FT MSL)

Period: August, 1967-July, 1969 Meteoro- Preferred logical Return Period (Months) Direction and Condition Duration S1.0 S = 0.9 S = 0.8 Speed (mph)

All 8 hr 5 <1 <1 SE-NW 1 All 12 hr 7 1 1 SE-NW 1 All 24 hr 15 2 <1 SE-NW 2 All 2 days 32 3 <1 SE-NW 2 All 4 days 60 17 4 SE-NW 3 All 8 days 160 55 17 NW-SE 4 All 16 days 330 120 37 NW-SE 4 All 30 days 900 300 95 NW-SE 4 Stable 8 hr 7 1 <1 WNW-SE 1 Stable 12 hr 18 3 <1 WNW-SE 1 Stable 24 hr 48 15 5 WNW-SE 2 Stable 48 hr 450 210 100 WNW-SE 2 (A steadiness value (S)1.0 implies almost no variation of the mean wind direction; value of 0.9, no more than 18 fluctuation; 0.8, no more than 36).

CHAPTER 02 2.3-64 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.26 STEADINESS FACTORS PEACH BOTTOM WEATHER STATION NO. 2 NOMINAL 320-FT LEVEL (EL 688 FT MSL)

Period: August, 1967-July, 1969 Meteoro- Preferred logical Return Period (Months) Direction and Condition Duration S1.0 S = 0.9 S = 0.8 Speed (mph)

All 8 hr 5 <1 <1 NW-SE 3 All 12 hr 7 1 <1 NW-SE 3 All 24 hr 15 1 <1 NW-SE 3 All 2 days 25 3 <1 NW-SE 4 All 4 days 65 15 3 NW-SE 4 All 8 days 140 52 20 NW-SE 6 All 16 days 260 115 47 NW-SE 6 All 30 days 700 270 05 NW-SE 6 Stable 8 hr 8 <1 <1 NW-SE 3 Stable 12 hr 30 4 1 NW-SE 3 Stable 24 hr 63 22 7 NW-SE 4 Stable 48 hr 650 320 160 NW-SE 4 (A steadiness value (S)1.0 implies almost no variation of the mean wind direction; a value of 0.9, no more than 18 fluctuation; 0.8, no more than 36.)

CHAPTER 02 2.3-65 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.27 BIVANE MEASUREMENTS PEACH BOTTOM WEATHER STATION NO. 2 NOMINAL 150-FT LEVEL (EL 518 FT MSL)

Period: August, 1967 - July, 1969*

Mean Values Angular Direction Standard Deviation()

Range () ()

Turbulence Class Azimuth Elevation Azimuth Elevation e/ a II 27 15 9 5 .55 III >36 >36 >12 >12 1 IV 22 15 7 5 .69 V 10 6 3 2 .66 Modal Values II 25 14 8 5 .62 III >36 >36 >12 >12 1 IV 23 15 8 5 .62 V 5 3 2 1 .50

• Ten individual months of data from this period covering eight different calendar months are included.

CHAPTER 02 2.3-66 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.3.28 LEAST FAVORABLE METEOROLOGICAL CONDITIONS Elevated Release Time After % of Period Wind Speed Turbulence Type of Accident Affected (m/sec) Class Model 0-8 hr 100 1 V Centerline 8-24 hr 100 2 V 22 1/2 Sector 1-4 days 50 2 V 22 1/2 Sector 50 5 IV 4-30 days 10 2 V 22 1/2 Sector 10 4 II 10 5 IV Ground Release 0-8 hr 100 1/2 V Centerline 8-24 hr 100 1 V 22 1/2 Sector 1-4 days 50 1 V 22 1/2 Sector 50 2 II 4-30 days 10 1 V 22 1/2 Sector 10 2 II 10 3 IV CHAPTER 02 2.3-67 REV. 21, APRIL 2007

PBAPS UFSAR Table 2.3.29 CHAPTER 02 2.3-68 REV. 22, APRIL 2009

PBAPS UFSAR Table 2.3.29 CHAPTER 02 2.3-69 REV. 22, APRIL 2009

PBAPS UFSAR Table 2.3.29 CHAPTER 02 2.3-70 REV. 22, APRIL 2009

PBAPS UFSAR Table 2.3.29 CHAPTER 02 2.3-71 REV. 22, APRIL 2009

PBAPS UFSAR Table 2.3.29 CHAPTER 02 2.3-72 REV. 22, APRIL 2009

PBAPS UFSAR 2.4 HYDROLOGY 2.4.1 General Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-1 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 2.4.2 Land Area Ground Hydrology 2.4.2.1 Introduction This section presents the results of the hydrologic investigation made in connection with environmental studies at the PBAPS site, and presents the results of field explorations conducted for this phase of the work.

Publications were reviewed, organizations contacted, and individuals interviewed to obtain information which, combined with field observations and tests, provides the basis for the conclusions presented. These conclusions consider both:

1. The effects of the station upon the natural surface and subsurface ground water conditions.

2. The effect of normal, flood, and drought conditions on the station.

2.4.2.2 Surface Water 2.4.2.2.1 Regional Southeastern Pennsylvania is, for the most part, drained by the Delaware and Susquehanna Rivers and their tributaries. The major surface stream in the area is the Susquehanna River, which originates at Lake Otsego in New York and terminates in the Chesapeake Bay. Most of the streams in the area drain into the Susquehanna River Basin. The Peach Bottom site is located about 14 mi northwest of the river's mouth at the head of the Chesapeake Bay.

Observed flows in the Susquehanna River near the site ranged from a minimum daily average (1964) of 1,400 cfs to a peak (1972) of 972,000 cfs. Average discharge is 36,200 cfs. Peak flows in the upper Susquehanna River are controlled by several flood control dams (Table 2.4.7).

The Peach Bottom site is located on the west bank of the pond formed by Conowingo Dam. The normal pool elevation at Conowingo CHAPTER 02 2.4-2 REV. 26, APRIL 2017

PBAPS UFSAR Dam is between +104 ft and +109.25 ft (C.D.). During the flood of 1936, the river stage at the site was approximately Elevation +113 ft (C.D.).

Minimum pool levels are established prior to expected flood flows when the water level is lowered as much as 10 ft to provide storage capacity during flood conditions.

Plant grade is established at Elevation +116 ft (C.D.).

Consequently, because of the available freeboard, inundation of the site is considered improbable, even under flood conditions.

During the Hurricane Agnes record flood of 1972 the water level rose to Elevation 114.2 ft (C.D.), exclusive of waves and run-up, which is still 1.8 ft below plant grade.

Average annual values for precipitation in the Susquehanna River Basin have been compiled for a period of 68 years (through 1955) at York, Pennsylvania, about 28 miles northwest of the site. The annual precipitation recorded for the period is subject to wide variation, ranging from a low of 22.9 inches to a high of 55.9 inches. Average annual precipitation for the period of record is 40.4 inches. The water loss through evaporation and absorption by the soil is estimated to be about 22 inches (55 percent) and the runoff into streams and rivers approximately 18 inches. The maximum and minimum mean monthly precipitations are 4.25 inches in July and 2.70 inches in November, respectively. Similar records have been kept at Conowingo Dam. The mean monthly maximum, mean monthly minimum, and mean annual precipitation during a 25 year of record at Conowingo Dam are 4.80 inches, 2.87 inches, and 45.44 inches, respectively.

2.4.2.2.2 Site The Peach Bottom site is located in a rural, sparsely populated area within the Susquehanna River Basin. The area surrounding the site is characterized by broad ridgetops and steep hillsides.

Topography of the area ranges from about Elevation +110 ft (C.D.)

at the river to above +400 ft (C.D.) beyond the property limits.

This relatively rugged topography results in well-dissected drainage courses which are apparently unrelated to geologic structure. It is believed that the stream courses existed prior to the geologic uplift of the region.

The major surficial drainage course within the property limits is Rock Run, which flows in a general easterly direction into Conowingo Pond just south of Unit 1.

CHAPTER 02 2.4-3 REV. 26, APRIL 2017

PBAPS UFSAR Rock Run is a perennial stream dividing the property into two sections. The watershed area of the creek is approximately 4 sq mi. Due to its limited drainage area and steep banks, Rock Run presents no flood danger to the proposed construction. About two-thirds of the runoff within the property limits is diverted by means of perennial and intermittent streams into Rock Run and subsequently into Conowingo Pond. The remaining runoff flows directly into the pond.

The amount of runoff in the area is estimated to average 18 in/yr, about 45 percent of the annual precipitation. Numerous factors control the amount of runoff. Among these are:

1. The type, intensity, and duration of the precipitation.

2. The temperature in the watershed area.

3. The amount and type of vegetal cover.

4. The topography of the drainage area.

5. The permeability of the upper soils.

Although the site area is covered with dense vegetation, the site topography is more rugged than that in the surrounding area.

Comparing the site characteristics to those of the surrounding area, the site runoff is about the same or slightly greater than the estimated area runoff.

2.4.2.3 Ground Water 2.4.2.3.1 Regional The region includes two greatly different ground water provinces which correspond to the two major physiographic divisions known as the Piedmont Province (in which the site is situated) and the Coastal Plain Province. The Fall Zone separates the two provinces.

The Coastal Plain is underlain by an alternating sequence of impermeable silt and clay strata and permeable sand and gravel beds, forming a series of aquicludes and aquifers. The Piedmont Province comprises a separate and topographically higher ground water province. There is essentially no hydrologic connection between the Piedmont and Coastal Plain Provinces with respect to ground water occurrence and water use.

CHAPTER 02 2.4-4 REV. 26, APRIL 2017

PBAPS UFSAR In the Piedmont Province within the region, the overall water table gradients and ground water discharge are toward the Delaware River Basin, the southeast geographic boundary of the Piedmont.

However, other major drainage basins within the area, such as the Susquehanna River, may locally reverse the overall hydrologic trend.

The rocks of the southeastern Piedmont Province generally furnish small supplies of potable water. Most wells in the region yield only small quantities of water. These wells are sufficient for domestic needs, but generally are inadequate for public or industrial use. Most of the wells are less than 100 ft deep, and obtain water from fractures and crevices in the zone of weathered rock. About half the wells in the region yield from 5 to 20 gpm and about one-quarter yield from 20 to 100 gpm. The remaining wells yield less than 5 gpm. Yields in excess of 100 gpm are extremely rare.

Two small groups of summer cottages are located near Conowingo Pond. One is located less than 1 mi north and the other 1 1/2 mi south of the Peach Bottom site. Domestic water supplies for these residents are obtained from shallow overburden wells which yield less than 10 gpm. PBAPS has several closed groundwater wells and four wells that provide non-potable water to remote facilities.

One well is at the North Substation and one is at the Salt Storage Facility at the North Substation. No information is available on the depth or capacity of either well. A third well is in the Upper North Parking Lot. It is 200 feet deep and provides 6 gpm.

It is used occasionally for washing hands or rinsing equipment.

The fourth well, at the South Substation, is 300 feet deep and provides 1 gpm to a toilet at the substation.

Most of the ground water recovered in the region is soft, but some is moderately hard and contains iron in undesirable amounts. The small available ground water supplies are derived from precipitation that soaks into and through the soil and weathered rock in limited areas surrounding each well. The water percolates into drilled wells through fissures and cracks that thin out and disappear with increasing depth in the bedrock.

Ground water moves in the overburden and rock fissures in the direction of the nearest stream or spring. The ground water flows under phreatic conditions and tends to support the perennial flow of the many streams in the region. Throughout most of their lengths, the streams, therefore, generally act as drains rather than as sources of ground water. They would act as sources of CHAPTER 02 2.4-5 REV. 26, APRIL 2017

PBAPS UFSAR recharge only where pumping of wells reverses the natural direction of ground water movement. The reversal of ground water movement in the area due to wells is unlikely since:

1. The population is rather sparse.

2. Most of the land is undeveloped or used for agricultural purposes.

3. There is little industry.

4. The major water sources are surficial.

5. Wells are relatively unproductive and influence only a limited area, resulting in little, if any, recharge from the local streams.

The movement of ground water in the area generally follows the topography and is toward and into the Susquehanna River Valley.

The occurrence of springs in a number of places in the slopes facing the river confirms that the movement of ground water is away from the upland areas and toward the river.

2.4.2.3.2 Site Water level observations made in the borings drilled for this investigation indicate that the ground water table at the site slopes downward to the east and roughly follows the ground surface topography. The direction of ground water flow is toward Conowingo Pond. The overall gradient of the water table is approximately 15 percent, but local variations were observed.

The water table ranges from over 100 ft below the ground surface in the higher western portion of the plant area to pond level at the easterly limit of the site. The ground water levels recorded at the site ranged from about Elevation +109 ft (C.D.) to Elevation +250 ft (C.D). The pond level during this same observation period was approximately Elevation +109 ft (C.D.). It is anticipated that in the area adjacent to the pond the ground water levels will vary with changes in the pond level, but that inland the phreatic will be relatively unaffected by moderate variations in the pond level.

Field permeability tests were conducted at specific horizons in seven test borings drilled during this investigation. The field permeability tests included both pump-in tests and bailing tests.

The test results are presented in Tables 2.4.1 through 2.4.3. The CHAPTER 02 2.4-6 REV. 26, APRIL 2017

PBAPS UFSAR test results were extremely erratic and reflect the influence of spacing, width, and continuity of the joints, fractures, and weathered rock seams on the gross permeability of the rock mass.

The unfractured relatively fresh rock appears to be impermeable.

Based upon field observations and the field testing program, it is believed that the joints and seams in the rock are neither continuous nor interconnected. The volume of water contained in the rock within a seam is therefore limited. Consequently, the measured permeability during a field test would be expected to decrease as the water drains from the water bearing zone within the rock. The field permeability test results confirm this supposition. The permeability data, therefore, should be used in a qualitative manner and should be considered accurate as to order of magnitude only.

The measured permeability in the Peters Creek schist ranged from under 0.1 ft/day in the relatively unweathered zone to greater than 20 ft/day in the highly weathered and fractured material.

The results of the near-surface percolation tests performed in the overburden soils were relatively consistent and reflect the similarity of the natural residual soils throughout the site area.

The measured permeability of the overburden generally ranged from 0.1 to 0.3 ft/day. However, occasional pockets of more permeable soil were observed.

The rate of ground water flow at the site is dependent upon the permeability of the residual natural soils and the frequency of fissures and fractures in the underlying rock. The rate of flow is usually slow because of the moderate gradients involved.

Temperature measurements of the ground water in the borings, as indicated in Table 2.4.4, ranged from 51F to 53F during the winter of 1966-67, the period of the field explorations. During the same period, the temperature of the water in Conowingo Pond was 34F.

Peach Bottom began installation of groundwater monitoring wells in 2006 in accordance with the Nuclear Energy Institute (NEI) document NEI 07-07, "Industry Ground Water Protection Initiative."

A total of 31 groundwater monitoring wells were installed between 2006 and 2011. The monitoring wells are installed in the overburden and bedrock. Well depths range from 6.5' to 105'.

CHAPTER 02 2.4-7 REV. 26, APRIL 2017

PBAPS UFSAR NEI 07-07 requires an initial hydrogeological study. This was completed in 2006. Periodic updates to the station's hydrogeology are also required.

2.4.2.4 Conclusions The direction of ground water movement in the area is toward Conowingo Pond. Joints and fractures in the rock at the site appear to be of limited extent. Since the rate of ground water movement is largely controlled by the number and arrangements of joints and fractures in the rock, the amount of flow will be small. The overlying natural soil is not very permeable and would limit recharge to the underlying rock.

There are no known deep aquifers of any extent in the region and the bedrock becomes sounder with depth. The possibility of ground water flow inland from the site is highly improbable.

No drinking wells are located down-gradient from the plant area.

The hydrologic characteristics of the site and surrounding area and the pattern of ground water use indicate that accidental discharge of radioactive fluids on or below the ground surface would have no adverse effect on existing or potential local ground water use. Fluids will run off or percolate in the direction of Conowingo Pond. Ground water monitoring wells are located down-gradient from the plant area.

2.4.3 River Hydrology 2.4.3.1 Introduction The Susquehanna River drains an area of 27,000 sq mi upstream from the Peach Bottom site. Observed flows near the site since 1929 have ranged from a minimum daily average (1964) of 1,400 cfs to a maximum peak of 972,000 cfs (1972). The average flow is 36,200 cfs. The temperature of the water during July and August has averaged somewhat less than 80F, while the lowest temperature ever is about 34F.

The concentration of liquid radioactive releases were studied, and it was concluded that even under the lowest flow conditions of record, the radioactivity concentration in the pond will not be excessive.

The maximum flood of record occurred in June of 1972 when a flow of 972,000 cfs was measured. Units 2 and 3 have been designed to CHAPTER 02 2.4-8 REV. 26, APRIL 2017

PBAPS UFSAR be safely shut down in the event of occurrence of the probable maximum flood of 1,750,000 cfs.

CHAPTER 02 2.4-9 REV. 26, APRIL 2017

PBAPS UFSAR 2.4.3.2 Stream Flow The flows of the Susquehanna River are unregulated except for the minor influences of the three run-of-the-river hydro plants and one pumped storage hydro plant 4 mi upstream of Units 2 and 3.

Measured flows at Conowingo have ranged from a minimum daily average of 1,400 cfs in 1964 to a maximum of 972,000 cfs (peak) in 1972. The ratio of maximum to minimum of more than 500 to 1 is typical of unregulated streams in the eastern United States. The mean flow of the Susquehanna is 36,200 cfs. This is 1.34 cfs per sq mi or 18 in of runoff annually, which is about normal for a large watershed on which some 40 in of rain falls annually. The major gaging stations and the drainage areas above them are shown in Figure 2.4.1. The average monthly and annual river flows and the maximum and minimum average daily discharge in each month for the period 1929-1980 are shown in Table 2.4.5. Figure 2.4.2 is a duration curve which indicates the percentages of total time the river flows exceeded any magnitude. In Table 2.4.6 are listed for each month the minimum average 7-day flows at Conowingo.

The lowest minimum daily average unregulated river flows were recorded during the 1930-32 drought (1,450 cfs) and during 1962-64 (1,400 cfs). The minimum flows next in order are 1,775 cfs in the 1941 drought, 1,800 cfs in the 1966 drought, and 2,125 cfs in the 1939 drought. All other minimum daily averages exceed 2,400 cfs and the average of all minimum daily averages is 3,700 cfs. The river flow exceeds 5,000 cfs about 90 percent of the time. Future regulations of the river will undoubtedly increase the minimum discharges. However, the extent of the increase is unpredictable because of the many uncertainties as to future policy with regard to water resource conservation and development in the Susquehanna Basin.

The maximum discharge of 972,000 cfs (peak) which occurred in the 1972 flood caused by Hurricane Agnes is considered a rare occurrence. How much greater the flow might be in some future flood if the river were left unregulated is a matter of conjecture. In view of the control measures described below, it is reasonable to assume that a future discharge in excess of 972,000 cfs (peak) at Conowingo Dam is extremely unlikely. The three dams on the lower Susquehanna River passed the 1972 flood without difficulty.

The average of the peak annual discharges (1929 through 1980) is 290,000 cfs. Once in about 20 yr, on the average, the peak, unregulated discharge might exceed 550,000 cfs.

CHAPTER 02 2.4-10 REV. 26, APRIL 2017

PBAPS UFSAR Since World War II, the U.S. Corps of Engineers has worked continuously on flood control and water resources problems of the Susquehanna Basin. Reports on the West Branch and on the North Branch of the Susquehanna River were published in 1954(6) and 1957(7), respectively. The report on the Raystown Branch of the Juniata River appeared in 1962(8). The status of water resources development in Baltimore District was published in 1965(9,10). In all, 14 major dams have been completed on tributaries of the Susquehanna River; one is partially completed, six others have been authorized but not started, and one additional very large storage project has been given considerable study.

Table 2.4.7 gives some of the details of these dams and Figure 2.4.3 shows their locations.

The recent progress in the construction of flood control reservoirs in the Susquehanna Basin is believed to warrant an assumption that it is exceedingly improbable that Conowingo Dam will in the future have to pass a flood greater than that of 1972.

2.4.3.3 Factors Influencing the Concentration of Radioactivity in Conowingo Pond After Release After release of the diluted liquid radwaste from the Peach Bottom discharge canal, the concentration of radioactivity in the pond continues to decrease by several mechanisms. These include radioactive decay and mixing of the discharged water with additional pond water. An adjustable jet type discharge from the canal (which will maintain the discharge velocity between 5 and 7 fps) has been adopted to enhance this mixing with pond water.

Operation of the Muddy Run pumped storage hydroelectric plant also speeds mixing by reversing the normal downstream flow during the pumping cycle at river flows below about 13,000 cfs.

In order to estimate further dilution of liquid radwaste by pond water after release from the discharge canal, an extensive series of tests were run as part of the original license application under the supervision of Dr. D. W. Pritchard, Director of the Chesapeake Bay Institute of the Johns Hopkins University, utilizing the hydraulic model of Conowingo Pond located at the Alden Research Laboratories of Worcester Polytechnic Institute.

This same model was used to study the dissipation of heat from the circulating water effluent released to Conowingo Pond.

Dilutions were determined in the model tests by introducing Rhodamine B dye as a fluorescent tracer into the modeled Peach Bottom discharge canal under various conditions and measuring the CHAPTER 02 2.4-11 REV. 26, APRIL 2017

PBAPS UFSAR dye concentration in grab samples taken at numerous sampling stations throughout the pond model at appropriate times during the tests. Dye concentrations in the samples were measured with a Turner Fluorometer.

Initially, dye dilutions obtained with the model were confirmed to adequately represent Conowingo Pond by comparing model results with actual dye studies performed in Conowingo Pond in 1960 under corresponding flow conditions.

To determine dilutions in the pond under both normal and abnormal conditions, two series of model tests were run, one representing a continuous steady-state release of radioactivity and the other representing a sudden release of a larger quantity of radioactivity over a relatively short period of time, about 1 hr.

All model tests in which Units 2 and 3 were simulated were conducted over a period of time (about 6 hr) representing 2 weeks of plant operation with dye concentration measurements being taken throughout the second week. Since the flow schedules for the operation of the hydroelectric plants are repeated on a weekly cycle, this ensured that the flows in the model represented the same cyclic history pattern as Conowingo Pond.

The steady-state tests were run over a range of natural river flows in the Susquehanna varying from 0 (no flow through either Holtwood Dam or Conowingo Dam) to 150,000 cfs. In tests utilizing natural flows, all hydroelectric stations (Holtwood, Conowingo, and Muddy Run) were operated according to their combined planned programmed operating schedule, which is coordinated to use the available river flow most efficiently. The operating schedule appropriate for the particular flow utilized in each test was followed. Tests were run at zero flow with both Muddy Run operating and Muddy Run shut down.

In the steady-state tests, dye was continuously introduced into the heated condenser discharge water. In the other series of tests, a slug of dye was dumped into the Peach Bottom circulating water discharge canal at a time representing the beginning of the second week of plant operation; this sudden release was superimposed on a steady-state release of dye similar to that used in the earlier series of tests.

Results of the steady-state model tests indicate that at natural river flows below about 13,000 cfs (which occur about 30 percent of the time), some of the condenser circulating discharge water from Units 2 and 3 re-enters the plant circulating water intake.

CHAPTER 02 2.4-12 REV. 26, APRIL 2017

PBAPS UFSAR The alternating pumping and generation cycles of Muddy Run were found to cause corresponding cyclic fluctuations in the concentration of radioactivity in the plant circulating water intake at low flow, the highest concentration resulting from the pumping cycles as would be expected. The lower the natural river flow, the more pronounced was the effect. From model tests at zero flow and 5,000 cfs flow, it is possible to predict that under the most extreme condition of continuous low flow on record (an average flow of 2,500 cfs for 84 consecutive days in 1964), the concentration of radioactive materials, neglecting decay, released to the pond from the circulating water discharge canal of Units 2 and 3 would be about 2.8 times what it would be if there were no recirculation. This value is based on the radioactivity being continuously released at a steady rate over the entire period of low flow.

This is a conservative approach since liquid radwaste will normally be discharged during only a portion of each day; in addition, radioactive decay will occur to reduce the buildup of radioactivity in the pond over a period of time. Decay was not simulated in the dye tests, nor was credit given for decay in calculating the results. The factor of 2.8 is additionally conservative because this represents the worst point in the weekly cycle of hydro plant operation and persists for only a few hours.

An average factor for the entire 7-day cycle period is about 1.8 for this worst continuous low flow condition on record.

Based on the dye tests described above, the maximum concentrations of radioactivity both at Peach Bottom and at the public water intakes for various natural river flows are listed in Table 2.4.8 for the continuous release of 1 millicurie/day of liquid radwaste to the discharge canal with full circulating water flow in Units 2 and 3. Very little variation in concentration was found anywhere in the pond below Peach Bottom for a given river flow. The highest concentration found at any water intake from a 1-millicurie/day continuous release is 2.2 x 10-10 Ci/cc or about 0.0022 of the maximum permissible concentration even under the worst condition of low flow on record. This amount of radioactivity is small compared to 1.2 x 10-8 Ci/cc, the average monthly concentration of total gross beta activity in the Susquehanna River at Conowingo reported by the U.S. Public Health Service from May, 1960 (when Conowingo became a part of the National Water Quality Network) through November, 1967. The concentration of total gross beta activity during this period reached a peak on the order of 6 x 10-8 Ci/cc in 1962 due to CHAPTER 02 2.4-13 REV. 26, APRIL 2017

PBAPS UFSAR fallout from bomb testing and has averaged about 5 x 10-9 Ci/cc between 1965 and 1967.

Similar measurements reported by the National Water Quality Network on samples taken at Holtwood Dam indicate that the total gross beta activity (on dissolved and suspended material) of river water averaged about 1.6 x 10-8 Ci/cc from November, 1961 through January 1969 and averaged 8 x 10-9 Ci/cc between January 1966 and January 1969.

It is concluded, therefore, that liquid radwaste routinely discharged to Conowingo Pond from Peach Bottom Units 2 and 3 will not result in excessive concentration of radioactivity in the pond.

Results of the slug tests on the model allow prediction of the concentration of radioactivity which would be present at various locations throughout Conowingo Pond in the unlikely event that a quantity of radioactivity were inadvertently released to the discharge canal over a short period of time. Release to the environment of a large quantity of radwaste, such as the emptying of a tank, is considered not credible because all outdoor tanks containing radioactive liquids which might flow to the pond are contained in watertight structures to prevent such an event. (See Sec. 9.2.4.1) An inadvertent slug release of an undiked tank outside the radwaste enclosure has been considered; the results show that even this would produce no significant risk to the public.

The quantity of radioactive material contained in any outside tanks that are not surrounded by liners, dikes, or walls capable of holding the tank contents and that do not have tank overflows and surrounding area drains connected to the liquid radwaste treatment system shall be limited in total activity to ensure that the permissible concentration limits at any offsite water intake cannot be exceeded by a sudden release of the tank (see Table 9.2.7b). This also applies to outside tanks contained within structures that can no longer perform their design function of holding the tank content to prevent a release to the environment.

The maximum concentrations occurring both at Peach Bottom and at the public water intakes resulting from the sudden release of a total of 1 Ci to the discharge canal are shown in Table 2.4.9.

The 1-Ci basis for this table was selected to simplify the calculation of concentrations resulting from the release of any quantity of radioactivity. Table 9.2.7b uses the data in Table 2.4.9 to illustrate the maximum effect (MPC) to any supply intake CHAPTER 02 2.4-14 REV. 26, APRIL 2017

PBAPS UFSAR resulting from release of expected inventories in outside undiked tanks. For example, even if a total expected inventory of 3.8 curies in an undiked tank outside the radwaste area were inadvertently released to the discharge canal, the highest resulting concentration at any supply intake would be 3.8 times that shown in Table 2.4.9 (about 0.6 x 10-7 Ci/cc) or 3.8 times that shown in Table 9.2.7b (about 0.6 maximum permissible concentration {MPC} on an unidentified basis) at Conowingo with a 150,000 cfs flow. At the Peach Bottom intake even with a 2,500 cfs flow (lowest extended average flow on record), the concentration would be about 0.95 x 10-7 Ci/cc or 0.95 MPC on an unidentified basis.

It is considered not credible that an uncontrolled release to the pond of an entire inventory of an outside tank located within a watertight structure that is at least 500 ft. from the water's edge can occur. Considering that any outside tank not contained within watertight structures shall contain limited radioactive inventories to mitigate the effect of a postulated failure, it is concluded that the permissible concentration limits at the water intakes cannot be exceeded through the sudden release of radioactivity from the Peach Bottom station.

The model tests on the sudden release of radioactivity also provided information on the times at which various concentrations will occur throughout the pond. The time after a slug release that the maximum concentration occurs at the various intakes is listed in Table 2.4.9. At the Chester water intake, the time to reach maximum concentration varies from 144 hr (8.7 days) at a river flow of 2,500 cfs to 4 hr at 50,000 cfs. At high flows, exceeding about 100,000 cfs, none of the released activity would reach the Chester water intake. At the Baltimore water intake and Conowingo tailrace, the times to reach the maximum concentration are slightly longer.

After the maximum concentration is reached, concentrations decrease with time. An estimate of the rate of decrease can be obtained from the data in Table 2.4.10, which presents the times required for the concentration in the pond to decrease to various fractions of complete mixing, i.e., to various fractions of 2.8 x 10-9 Ci/cc, the concentration which would result if 1 Ci were uniformly mixed in the entire static volume of water in Conowingo Pond at mean water level. This information allows estimation of the concentration in the pond versus time resulting from a sudden slug release of radioactivity.

CHAPTER 02 2.4-15 REV. 26, APRIL 2017

PBAPS UFSAR Taken together, the hydraulic model tests have provided an excellent understanding of the effects of either a steady-state or sudden slug release of radioactivity and have demonstrated that even under the worst low flow conditions on record, the radioactivity released from Peach Bottom Units 2 and 3 will not result in excessive concentrations in Conowingo Pond.

2.4.3.4 Temperature Temperature records kept for 10 yr by the Conowingo Power Company show an average July and August water temperature of somewhat less than 80F. The minimum winter temperature of the river water is 34F. These temperatures are measured approximately 70 ft below the water surface.

2.4.3.5 Floods Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-16 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-17 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-18 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-19 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-20 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-21 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-22 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 CHAPTER 02 2.4-23 REV. 26, APRIL 2017

PBAPS UFSAR Security Related Information Withheld Under 10 CFR 2.390 2.4.3.5.6 Wind-Generated Waves and Wave Run-Up The height of wind-generated waves was computed using the greatest weighted average fetch, 2.0 mi, that will produce the most severe effect at the plant site. Wind velocities were measured at the site from 1967 to 1969. To supplement this short record, wind velocities at other points in the general area with longer history were examined.

At Philadelphia International Airport, with a 25-yr record, the fastest mile measured was 73 mph. At Harrisburg, Pennsylvania, with a 30-yr record, the fastest mile was measured at 68 mph. In both cases the direction was west. A sustained wind over a period of about 20 min is necessary for generation of fully developed waves at Peach Bottom. It is estimated that the maximum 20-min average velocity would be about 80 percent of the peak. From a consideration of the surrounding conditions, recorded wind velocities, wind direction, effect of topography, and time required for waves to develop, a 45-mph wind on a 2-mi fetch was used in computing a wave height of 2.7 ft, measured from trough to tip. The tip is assumed to be two-thirds of the wave height above still water. Superimposing an additional 1.8 ft of wind-generated CHAPTER 02 2.4-24 REV. 26, APRIL 2017

PBAPS UFSAR waves on the conditions assumed previously yields a peak elevation top of wave tip of Elevation +133.8 ft (C.D.). Compared to the protection level provided of Elevation +135.0 ft (C.D.), this leaves additional freeboard of 1.2 ft.

This margin of freeboard, together with the conservative assumptions used in computing the water level under hypothesized PMF conditions, is considered more than adequate for the safety criteria of the plant.

The maximum wave of the spectrum analyzed is estimated to be approximately 1.67 times the significant wave height, or 4.5 ft high. Only a small percentage (1 percent) of all waves reach this maximum height.

Wave run-up is defined as the height above still-water level to which a wave rises when it encounters an obstruction. At Peach Bottom the obstructions encountered are the vertical walls of the various buildings. One of the parameters necessary to determine the height of wave run-up is the ratio of the depth of still water to the wave height. Previous wave studies indicate that as this ratio increases above about 3.0, the height of run-up decreases.

In estimating run-up at this site, a ratio of depth of still water to height of wave of 3.0 was used, although under design conditions the actual ratio was 4.0 for structures away from the shore and about 10.0 for the pump structure located at the shoreline. The wave run-up heights estimated are, therefore, greater than the height that might occur. It is estimated that the significant waves will run up 3.5 ft and the maximum waves 5.4 ft. The maximum wave run-up superimposed on the steady-state PMF Elevation +131.5 ft (C.D.) results in an Elevation of +136.9 ft (C.D.).

2.4.3.5.7 Safe Shutdown of Structures and Components for Units 2 and 3 due to Run-up of the Maximum Wave Superimposed on the Probable Maximum Flood Water Level Structures The following describes the structures required for safe shutdown of Units 2 and 3, assuming that no accident occurs concurrently.

In addition, the radwaste building is flood protected to Elevation

+135.0 ft (C.D.) but is not required for safe plant shutdown.

CHAPTER 02 2.4-25 REV. 26, APRIL 2017

PBAPS UFSAR

1. Reactor Building This structure has a minimum number of doors below Elevation +135.0 ft (C.D.). They are watertight. The structure is sealed to Elevation +135.0 ft (C.D.).

Reactor building doors above Elevation +135.0 ft (C.D.)

are weatherstripped for leaktightness as secondary containment. Since these doors are well on the shoreside of the structures, maximum waves are not expected. Even if an excessive wave were to reach these doors which are the most vulnerable part of the building envelope, no significant inflow is anticipated. Small amounts of water which might leak through the doors' weatherstripping would be handled by the building drainage system and pumped out.

2. Main Control Room Complex The control room and cable spreading room are well above the flood level. The emergency switchgear room is at Elevation +135.0 ft (C.D.), well above the maximum still-water level of +132.0 ft (C.D.) (paragraph 2.4.3.5.4.2). Since it is inside the turbine building, no wave run-up effects are anticipated. The turbine building will be allowed to flood to equalize the water level to avoid excessive unbalanced hydrostatic loads on the exterior walls.

3. Diesel-Generator Building This structure has watertight doors to above Elevation

+138.0 ft (C.D.) or more than 1.1 ft above the maximum wave run-up.

4. Pump Structure The parapet around the roof of the critical pump area is at Elevation +137.5 ft (C.D.) or 0.6 ft above the estimated maximum wave run-up of Elevation +136.9 ft (C.D.).

5. Emergency Heat Sink Facility Including Cooling Tower This structure has one weathertight door below the maximum wave run-up elevation and is sealed against flooding to above this height (except for the door). All CHAPTER 02 2.4-26 REV. 26, APRIL 2017

PBAPS UFSAR equipment required for safe shutdown is protected by the structures described above.

Components Components required for safe shutdown of Units 2 and 3 include the following:

1. Reactor vessel and internals

2. Control rod drive system (portion essential for scram)

3. Recirculation piping system

4. RCICS

5. RHRS

6. High-pressure service water system

7. Emergency cooling system

8. Emergency service water system

9. Standby power systems

10. Instrumentation and controls

a. Reactor level instrumentation

b. Reactor pressure instrumentation.

For drawings of structures and components, see Drawings C-84 Sheet 1, M-2 through M-7 and Figures 12.1.1, and 12.2.1.

The structures required for safe shutdown were statically checked for hydrostatic pressures caused by PMF with no loss of function.

The pump structure was further investigated for the effects of floating objects weighing 10,000 lb, 50 ft long by 2.5 ft in diameter, traveling at 5.0 fps and impinging upon it, and the bottom slab was checked for pressure differentials caused by the PMF.

The elevation of the cooling water intake invert at the screen structure is +84.0 ft (C.D.).

CHAPTER 02 2.4-27 REV. 26, APRIL 2017

PBAPS UFSAR At the pump structure, the water intake invert is +79.83 ft (C.D.)

(Drawing C-84 Sheet 1). For location on-site refer to Drawing C-1.

Watertight doors are provided at all structures; waterproofing is installed to Elevation +135.0 ft (C.D.), and any penetration in the exterior walls is sealed to ensure leaktightness necessary to plant safety. For further discussions, see FSAR Section 12.0, "Structures and Shielding."

2.4.4 Uses of River 2.4.4.1 Introduction The reach of the Susquehanna River impounded by Conowingo Dam is part of an extensive hydroelectric development.

There are six existing water supply intakes on the Susquehanna River downstream from the Peach Bottom site.

The Conowingo Pond is used by a moderate number of boaters and fishermen during the recreation season.

2.4.4.2 Industrial Use Along the lower 35 mi, where the river flows between steep hills, are located four major hydroelectric plants: Safe Harbor, Holtwood, Muddy Run, and Conowingo. The Conowingo Dam is approximately 9 mi downstream from the site while the Holtwood Dam is 6 mi upstream. The pumped storage facility at Muddy Run which uses the Conowingo Pond as a lower reservoir is located 4 mi upstream.

During low flows, the hydroelectric plants are operated intermittently to meet peak daily demands. Conowingo Pond is scheduled to be full on Monday morning and lowered by intermittent operation through the week to the point that it will just fill over the weekend. At high flows the hydroelectric plants operate on the base load and peaks are carried by steam electric generating units.

2.4.4.3 Public Use The generally steep shoreline of the Susquehanna River restricts access to a limited number of locations for water related recreational activities by the public. In the vicinity of the upriver property line of the plant site, the Township Commissioners had been granted permission and operated a boat CHAPTER 02 2.4-28 REV. 26, APRIL 2017

PBAPS UFSAR launching area; however, this permission was terminated at the beginning of plant construction. Upon completion of Units 2 and 3, a new upriver boat launching facility with operation under control of the licensee was constructed. The river is at least 7,200 ft wide at this point, and, especially in the summer, boaters are attracted to the area.

The river below Peach Bottom can presently be used as a source of water supply for the city of Havre de Grace, the Perry Point Veterans' Hospital, the Conowingo Village, the city of Baltimore, the city of Chester, and the Bainbridge Naval Training Station, which in turn supplies water to the town of Port Deposit, Maryland.

The two largest potential water users are the city of Baltimore and the city of Chester. The intake for the city of Baltimore is located about 1,000 ft upstream of Conowingo Dam, with a 38-mi pipeline bringing the water to an existing reservoir. The city of Baltimore can presently withdraw up to 150 million gal of water per day from Conowingo Pond. The city first diverted Susquehanna River water on January 12, 1966. Since 1970, water has been diverted very sparingly, mostly for test purposes.

The intake for the Chester Water Authority, which supplies water to the city of Chester, is located about 7 mi upstream of Conowingo Dam. The Chester Water Authority can withdraw up to 32 million gal of water per day from Conowingo Pond. The Authority first diverted Susquehanna River Water on November 6, 1970. Since mid-1971, water has been diverted very sparingly, mostly for test purposes.

The quality of water in the lower river is good, as indicated by the uses for water supply, recreation, and sport fishing.

CHAPTER 02 2.4-29 REV. 26, APRIL 2017

PBAPS UFSAR 2.4 HYDROLOGY REFERENCES

1. Hall, George M., "Ground Water in Southeastern Pennsylvania,"

Pennsylvania Topographic and Geologic Survey, Bulletin W2, 1934.

2. U.S. Weather Bureau, 1964, "Climatography of the United States," Number 86-15 Maryland and Pennsylvania, 1951 through 1960.

3. U.S. Weather Bureau, 1964, "Climatography of the United States," Number 86-32 Pennsylvania, 1951 through 1960.

4. Lohman, S.W., "Ground Water Resources of Pennsylvania,"

Pennsylvania Topographic and Geologic Survey, Bulletin W7.

5. "Final Hazards Summary Report," Part C - Volume 1, Site and Environmental Information, PECO Energy Company (PECO),

formerly, Philadelphia Electric Company.

6. "West Branch of the Susquehanna River, Pa.," Report of the District Engineer, Baltimore District, U.S. Corps of Engineers, February 29, 1952. Published 1954 as House Document 25, 84th Congress, 1st Session.

7. "North Branch of the Susquehanna River and Tributaries, New York and Pennsylvania," Report of the District Engineer, Baltimore District, U.S. Corps of Engineers, December 30, 1950. Published as House Document 394, 84th Congress, 2nd Session.

8. "Juniata River and Tributaries, Pa.," Report of the District Engineer, Baltimore District, U.S. Corps of Engineers, June 30, 1961. Published 1962 as House Document 565, 87th Congress, 2nd Session.

9. "Water Resources Development by the U.S. Army Corps of Engineers in Pennsylvania," U.S. Army Engineer Division, North Atlantic, January 1, 1965.

10. "Water Resources Development by The U.S. Army Corps of Engineers in New York," U.S. Army Engineer Division, North Atlantic, January 1, 1965.

CHAPTER 02 2.4-30 REV. 26, APRIL 2017

PBAPS UFSAR

11. Supplemental Agreement to the PECO Energy Company (PECO),

formerly the Philadelphia Electric Company, AEC Contract No.

AT(40-1)2586.

CHAPTER 02 2.4-31 REV. 26, APRIL 2017

PBAPS UFSAR TABLE 2.4.1 FIELD PERMEABILITY TEST DATA PUMP-IN TESTS Boring H-11 Ground Surface Elevation = 238.0 ft Elevation of Static Water Table = 164 ft Elevation of Bottom of Depth of Boring Calculated Boring Below Casing Head Flow Permeability (ft) Material (ft) (ft) (gpm) (ft/day) 232 Light brown 2 6 .043 0.3 silt with little fine to coarse gravel 227 Light brown 2 11 6.0 22.4 silt with little fine to coarse gravel 223 Light brown 1 15 1/2 .028 0.1 silt with little fine to coarse gravel 217 3/4 Light brown 1 1/4 20 1/2 .090 0.2 silt and fine gravel 203 1/2 Peters Creek 5 1/2 32 3/4 .20 0.1 schist (moderately weathered) 198 P.C.S. (moderately 11 35 1/2 1.3 0.5 weathered) 194 P.C.S. (moderately 15 37 1/2 10 2.6 weathered)

KEY: P.C.S. = Peters Creek schist CHAPTER 02 2.4-32 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.1 (Continued)

Elevation of Bottom of Depth of Boring Calculated Boring Below Casing Head Flow Permeability (ft) Material (ft) (ft) (gpm) (ft/day) 189 P.C.S. (moderately 20 40 2.0 0.4 weathered) 183 1/2 P.C.S. (highly 25 1/2 42 3/4 30 4.4 weathered) 178 1/4 P.C.S. (highly 30 3/4 45 1/2 28 3.3 weathered) 173 1/2 P.C.S. (moderately 35 1/2 47 3/4 25 2.5 weathered) 168 P.C.S. (moderately 41 50 1/2 23 2.0 weathered) 164 P.C.S. (moderately 45 52 1/2 23 1.8 weathered) 159 P.C.S. (moderately 50 55 23 1.5 weathered) 153 1/2 P.C.S. (moderately 55 1/2 57 3/4 24 1.4 weathered) 148 1/2 P.C.S. (moderately 60 1/2 60 1/4 38 2.0 weathered) 143 1/2 P.C.S. (moderately 65 1/2 62 3/4 42 2.0 weathered) 138 1/2 P.C.S. (moderately 70 1/2 65 1/4 36 1.5 weathered) 133 1/2 P.C.S. (moderately 75 1/2 67 3/4 40 1.5 weathered) 128 1/2 P.C.S. (moderately 80 1/2 70 1/4 45 1.5 weathered) 123 1/2 P.C.S. 85 1/2 72 3/4 47 1.5 (unweathered)

CHAPTER 02 2.4-33 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.1 (Continued)

Elevation of Bottom of Depth of Boring Calculated Boring Below Casing Head Flow Permeability (ft) Material (ft) (ft) (gpm) (ft/day) 118 1/2 P.C.S. 90 1/2 75 51 1.5 (unweathered) 113 1/2 P.C.S. 95 1/2 75 62 1.7 (unweathered) 108 1/2 P.C.S. 100 1/2 75 56 1.5 (unweathered) 103 1/2 P.C.S. 105 1/2 75 57 1.5 (unweathered) 98 1/2 P.C.S. 110 1/2 75 56 1.4 (unweathered) 93 1/2 P.C.S. 115 1/2 75 59 1.4 (unweathered) 88 1/2 P.C.S. 120 1/2 75 66 1.5 (unweathered) 85 P.C.S. 124 75 62 1.4 (unweathered) 80 1/4 P.C.S. 128 3/4 75 45 1.0 (unweathered) 75 1/4 P.C.S. 133 3/4 75 52 1.1 (unweathered) 70 3/4 P.C.S. 138 1/4 75 52 1.1 (unweathered) 65 1/2 P.C.S. 143 1/2 75 49 1.0 (unweathered) 61 P.C.S. 148 75 71 1.4 (unweathered) 54 1/2 P.C.S. 154 1/2 75 57 1.1 (unweathered)

CHAPTER 02 2.4-34 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.1 (Continued)

Ground Surface Elevation = 217.4 ft Elevation of Static Water Table = +/- 161 ft Elevation of Bottom of Depth of Boring Calculated Boring Below Casing Head Flow Permeability (ft) Material (ft) (ft) (gpm) (ft/day) 50 1/4 P.C.S. 158 3/4 75 56 1.0 (unweathered) 205 Gray silt and fine 2 11 31 115.0 to coarse gravel 200 1/2 P.C.S. 1 1/2 15 3/4 .218 0.7 (highly weathered) 193 1/2 P.C.S. (highly 8 1/2 19 1/4 26 20.0 weathered) 188 1/2 P.C.S. (highly 13 1/2 21 3/4 30 14.0 weathered) 183 1/2 P.C.S. (highly 18 1/2 24 1/4 46 16.0 weathered) 178 1/2 P.C.S. (highly 23 1/2 26 3/4 56 14.0 weathered) 173 1/2 P.C.S. (highly 28 1/2 29 1/4 31 6.2 weathered) 168 1/2 P.C.S. (highly 33 1/2 31 3/4 24 3.9 weathered) 163 1/2 P.C.S. (highly 38 1/2 34 1/4 24 3.2 weathered) 158 1/2 P.C.S. (highly 43 1/2 36 3/4 44 4.9 weathered) 155 P.C.S. 47 38 1/2 52 5.1 (unweathered) 152 P.C.S. 50 40 52 4.7 (unweathered) 147 P.C.S 55 42 1/2 70 5.4 (unweathered)

CHAPTER 02 2.4-35 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.1 (Continued)

Elevation of Bottom of Depth of Boring Calculated Boring Below Casing Head Flow Permeability (ft) Material (ft) (ft) (gpm) (ft/day) 142 P.C.S 60 45 82 5.6 (unweathered) 137 P.C.S. 65 45 86 5.5 (unweathered) 132 P.C.S. 70 50 94 5.1 (unweathered) 127 P.C.S. 75 52 1/2 97 4.8 (unweathered) 122 P.C.S. 80 55 112 4.9 (unweathered) 117 P.C.S. 85 55 3/4 75 3.1 (unweathered) 113 1/2 P.C.S. 88 1/2 55 3/4 72 2.8 (unweathered) 106 1/2 P.C.S. 95 1/2 55 3/4 84 3.2 (unweathered) 101 1/2 P.C.S. 97 1/2 52 3/4 68 2.7 (unweathered) 96 1/2 P.C.S. 102 1/2 52 3/4 66 2.5 (unweathered) 91 1/2 P.C.S. 107 1/2 52 3/4 76 2.8 (unweathered) 86 1/2 P.C.S. 112 1/2 52 3/4 72 2.5 (unweathered) 81 1/2 P.C.S. 117 1/2 52 3/4 78 2.6 (unweathered) 76 1/2 P.C.S. 122 1/2 52 3/4 75 2.6 (unweathered)

CHAPTER 02 2.4-36 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.1 (Continued)

Elevation of Bottom of Depth of Boring Calculated Boring Below Casing Head Flow Permeability (ft) Material (ft) (ft) (gpm) (ft/day) 71 1/2 P.C.S. 127 1/2 52 3/4 71 2.2 (unweathered) 66 1/2 P.C.S. 132 1/2 52 3/4 70 2.2 (unweathered) 61 1/2 P.C.S. 137 1/2 52 3/4 69 2.0 (unweathered) 55 1/2 P.C.S. 142 1/2 52 3/4 66 1.9 (unweathered) 51 1/2 P.C.S. 147 1/2 52 3/4 75 2.1 (unweathered)

CHAPTER 02 2.4-37 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.2 FIELD PERMEABILITY TEST DATE PUMP-OUT TESTS Depth To Elapsed Time After Water Completion Of Bailing Surface (min) (ft)

Boring H-3 1/4 57.3 Ground Surface Elevation =

249.4 ft 1 1/2 55.6 Depth to Bottom of Boring =

85 ft 2 1/2 55.2 Depth to Static Water Level =

52.0 ft 3 1/2 54.7 4 1/2 54.4 5 1/2 54.1 6 1/2 53.8 7 1/2 53.7 Average Permeability = 0.3 ft/day Boring H-3 1/2 57.0 Ground Surface Elevation =

249.4 ft 1 56.5 Depth to Bottom of Boring =

95 ft 2 55.8 Depth to Static Water Level =

52.0 ft 2 1/2 55.7 3 55.3 4 55.1 5 54.7 10 53.8 15 53.6 20 53.5 25 53.4 30 53.2 Average Permeability = 0.3 ft/day CHAPTER 02 2.4-38 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.2 (Continued)

Depth To Elapsed Time After Water Completion Of Bailing Surface (min) (ft)

Boring H-8 1 70.9 Ground Surface Elevation =

219.4 ft 2 70.3 Depth to Bottom of Boring =

95 ft 3 69.8 Depth to Static Water Level =

47.0 ft 4 69.0 5 68.3 6 67.7 7 67.2 8 66.6 9 66.0 10 65.5 15 62.7 20 60.2 25 58.6 31 57.8 40 57.0 50 56.6 290 47.5 Average Permeability = 0.03 ft/day Boring H-18 3/4 88.0 Ground Surface Elevation =

217.6 ft 2 85.7 Depth to Bottom of Boring =

97.5 ft 3 84.4 Depth to Static Water Level =

74.9 ft 4 83.2 5 82.2 6 81.5 8 80.5 10 79.9 15 79.0 20 78.4 25 78.1 30 77.7 Average Permeability = 0.1 ft/day CHAPTER 02 2.4-39 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.2 (Continued)

Depth To Elapsed Time After Water Completion Of Bailing Surface (min) (ft)

Boring H-18 1 59.8 Ground Surface Elevation =

217.6 ft 2 59.0 Depth to Bottom of Boring =

136.5 ft 3 58.6 Depth to Static Water Level =

53.3 ft 4 58.3 5 58.1 10 57.4 15 56.8 30 56.0 Average Permeability = 0.1 ft/day Boring H-19 1/2 85.4 Ground Surface Elevation =

211 ft 1 84.5 Depth to Bottom of Boring =

115 ft 2 83.9 Depth to Static Water Level =

79.3 ft 3 83.4 4 82.9 5 82.7 6 82.4 7 82.3 8 82.2 9 82.1 10 82.0 15 81.9 20 81.8 25 81.8 30 81.8 Average Permeability = 0.2 ft/day CHAPTER 02 2.4-40 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.2 (Continued)

Depth To Elapsed Time After Water Completion Of Bailing Surface (min) (ft)

Boring H-45 0 33.0 Ground Surface Elevation =

148 ft 1 22.8 Depth to Bottom of Boring =

50.0 ft 2 22.6 Depth to Static Water Level =

22.0 ft 3 22.5 4 22.5 5 22.5 6 22.4 11 22.4 16 22.4 Average Permeability = 0.2 ft/day CHAPTER 02 2.4-41 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.3 PERCOLATION TEST DATA Time for Water Soil Level to Fall 1" Absorptivity Test Soil Type (min) (ft/day)

A Reddish-brown sandy 9 1/2 0.23 silt with some fine to coarse gravel B Light brown silt with 70 0.08 little fine to coarse gravel C Light brown silt with 29 0.11 little fine to coarse gravel D Light brown silt with 135 0.07 little fine to coarse gravel E Brown sandy silt with 27 0.12 a trace of roots F Brown sandy silt with 48 0.09 a trace of roots G Light brown sandy 73 0.08 silt with little fine to coarse gravel H Light brown sandy 80 0.08 silt with little fine to coarse gravel I Dark brown organic 42 0.09 silt with a trace of roots J Dark brown organic 26 0.12 silt with a trace of roots CHAPTER 02 2.4-42 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.4 WATER TEMPERATURE DATA Depth of Measurement Temperature Boring (ft) (F)

H-1 200 51 H-3 100 51 H-8 90 52 H-11 140 51 H-15 90 52 H-17 130 51 H-19 90 52 H-21 80 51 H-23 70 51 H-28 60 51 H-32 45 51 H-35 55 51 H-45 25 53 H-47 45 52 H-65 85 51 H-67 60 52 H-71 35 53 H-77 75 52 Reservoir 0 34 Reservoir 5 34 Reservoir 15 34 CHAPTER 02 2.4-43 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.5 NATURAL RIVER FLOW OF THE SUSQUEHANNA RIVER AT CONOWINGO DAM MAXIMUM AVERAGE DAILY FLOW (cfs) 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 JAN. 90,600 113,400 9,450 92,400 52,975 109,525 184,300 51,175 249,150 103,325 JAN.

FEB. 128,475 179,750 21,125 84,725 92,075 17,025 65,275 59,800 109,930 92,175 FEB.

MAR. 254,950 145,375 153,450 112,825 189,000 125,625 141,550 756,000 62,875 115,250 MAR.

APR. 224,400 84,575 130,850 248,775 181,660 146,150 135,625 133,950 234,350 108,375 APR.

MAY 177,050 33,950 132,225 169,900 110,650 32,625 138,400 32,250 149,200 47,500 MAY JUNE 48,525 42,275 44,575 16,400 48,250 25,800 19,800 19,375 48,750 29,725 JUNE JULY 17,750 19,300 34,200 17,275 32,500 21,325 185,325 14,000 28,450 32,300 JULY AUG. 6,500 4,275 13,600 6,300 303,925 18,100 20,775 11,575 74,550 17,925 AUG.

SEPT. 8,600 8,125 8,875 4,575 117,900 128,150 11,050 9,800 36,925 70,725 SEPT.

OCT. 76,600 3,750 6,350 65,575 26,500 65,825 15,475 20,175 144,125 19,750 OCT.

NOV. 109,675 3,800 7,750 115,250 24,725 49,460 105,625 120,725 127,475 32,075 NOV.

DEC. 99,925 9,550 47,950 40,650 46,625 266,625 82,250 68,600 162,350 127,750 DEC.

MINIMUM AVERAGE DAILY FLOW (cfs) 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 JAN. 7,800 18,050 3,050 19,850 18,325 9,050 12,450 15,625 46,000 12,400 JAN.

FEB. 8,750 16,575 3,875 17,625 10,175 6,175 14,750 13,450 30,125 36,225 FEB.

MAR. 42,450 42,300 13,525 13,760 20,850 6,375 51,676 78,800 24,550 27,775 MAR.

APR. 36,350 29,275 25,150 23,400 39,525 22,650 30,850 28,500 33,325 31,075 APR.

MAY 42,300 15,050 26,550 17,225 33,700 12,150 14,950 13,375 28,175 16,700 MAY JUNE 11,250 13,375 10,500 9,400 9,550 7,525 9,425 8,700 13,200 8,850 JUNE JULY 7,100 4,100 7,000 5,425 6,225 4,175 8,000 3,350 7,425 8,725 JULY AUG. 3,275 2,075 5,250 3,525 5,925 5,125 6,175 3,575 6,925 6,225 AUG.

SEPT. 3,400 2,785 3,175 1,450 17,950 5,050 4,400 2,950 6,900 3,600 SEPT.

OCT. 6,425 1,600 2,450 2,060 8,925 8,750 3,375 4,275 4,375 6,250 OCT.

NOV. 18,375 1,800 2,950 26,450 8,800 11,175 11,150 9,075 22,850 7,850 NOV.

DEC. 12,975 1,900 4,850 6,500 8,325 19,075 12,125 8,050 12,450 13,300 DEC.

AVERAGE DAILY FLOW (cfs) 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 JAN. 16,491 46,783 5,305 44,744 28,906 46,393 44,968 29,456 101,650 37,358 JAN.

FEB. 20,271 35,502 9,659 41,863 25,394 11,447 30,717 19,022 50,648 58,938 FEB.

MAR. 102,185 74,910 33,126 34,210 78,658 39,341 85,286 251,865 39,869 63,380 MAR.

APR. 113,268 52,793 72,844 91,308 96,591 81,236 66,772 76,978 91,484 50,295 APR.

MAY 74,323 23,472 66,048 48,627 56,666 20,794 49,483 20,962 55,004 26,658 MAY JUNE 20,334 22,179 22,984 12,203 23,143 12,211 13,971 12,347 21,496 16,377 JUNE JULY 10,512 10,234 16,417 9,402 13,390 6,862 35,202 6,631 13,703 15,987 JULY AUG. 4,965 3,274 2,127 4,777 44,844 7,425 12,506 6,509 20,511 11,151 AUG.

SEPT. 5,334 4,101 5,372 2,845 39,124 28,152 6,932 5,095 14,711 16,596 SEPT.

OCT. 27,365 2,794 3,988 21,819 14,047 19,658 5,058 9,745 32,680 9,778 OCT.

NOV. 34,025 2,880 4,362 54,357 15,562 26,065 38,111 29,563 52,878 13,900 NOV.

DEC. 35,145 4,628 17,204 18,244 23,370 54,365 35,016 37,110 41,821 46,130 DEC.

YEARLY 38,727 23,630 20,423 32,075 38,308 29,496 30,375 42,107 44,705 30,296 YEARLY CHAPTER 02 2.4-44 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.5 (Continued)

MAXIMUM AVERAGE DAILY FLOW (cfs) 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 JAN. 33,750 19,250 138,850 34,350 455,150 61,475 71,825 173,225 87,050 35,650 JAN.

FEB. 213,500 33,850 34,975 44,750 144,700 47,325 157,700 29,425 99,250 118,075 FEB.

MAR. 153,725 199,125 87,925 223,200 188,500 187,425 259,275 216,025 120,400 267,175 MAR.

APR. 128,175 465,200 253,925 110,775 263,700 151,875 101,475 42,025 209,950 323,775 APR.

MAY 39,500 75,675 22,125 315,200 167,025 204,875 166,550 487,650 135,250 93,040 MAY JUNE 15,550 66,425 49,700 50,550 81,875 52,175 60,900 204,850 85,600 47,575 JUNE JULY 10,850 22,275 17,500 68,825 17,400 28,150 52,475 39,275 59,075 31,425 JULY AUG. 9,275 12,500 13,300 72,200 9,575 9,475 40,900 32,950 24,825 15,775 AUG.

SEPT. 6,725 41,300 8,925 34,500 7,100 9,200 85,950 18,925 26,325 6,475 SEPT.

OCT. 15,900 14,600 4,200 69,325 89,900 20,325 71,125 47,775 6,475 9,900 OCT.

NOV. 21,350 44,225 11,200 88,875 178,375 19,050 170,925 30,875 47,975 57,125 NOV.

DEC. 29,125 152,150 115,200 358,050 20,775 54,875 161,225 15,325 23,700 167,250 DEC.

MINIMUM AVERAGE DAILY FLOW (cfs) 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 JAN. 10,225 5,925 15,375 9,500 27,400 8,400 9,275 17,450 21,625 7,400 JAN.

FEB. 43,800 6,150 13,275 14,575 21,400 7,575 9,875 12,175 10,450 7,725 FEB.

MAR. 38,300 14,650 16,050 19,975 30,250 24,025 61,825 48,675 10,250 30,375 MAR.

APR. 42,125 68,700 24,275 22,325 26,300 38,625 27,675 14,150 43,700 50,600 APR.

MAY 13,800 23,425 8,550 16,100 41,150 28,125 46,875 12,050 48,475 48,725 MAY JUNE 8,250 12,575 7,400 13,725 13,750 14,600 21,600 26,600 17,050 18,600 JUNE JULY 3,875 8,275 5,025 7,850 7,275 5,700 11,375 9,575 14,700 12,000 JULY AUG. 2,975 4,750 3,875 11,474 5,400 3,650 9,450 9,225 11,500 7,175 AUG.

SEPT. 2,125 7,300 1,825 6,675 2,575 3,450 9,000 5,275 6,375 3,400 SEPT.

OCT. 3,625 6,000 1,775 12,325 3,300 4,575 18,975 8,975 4,000 4,025 OCT.

NOV. 6,225 7,675 4,450 22,425 21,525 6,275 22,950 9,750 5,775 4,775 NOV.

DEC. 5,950 14,000 6,125 10,525 6,700 13,950 16,100 9,575 9,900 15,975 DEC.

AVERAGE DAILY FLOW (cfs) 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 JAN. 19,930 10,091 36,935 20,031 83,346 19,050 24,805 55,145 46,998 16,945 JAN.

FEB. 87,799 15,097 20,278 25,701 56,674 19,272 38,843 19,314 32,406 40,292 FEB.

MAR. 84,639 53,711 43,743 87,694 84,227 82,356 152,845 95,331 49,240 104,332 MAR.

APR. 74,261 212,656 82,737 68,560 74,747 74,934 53,655 22,651 75,694 102,792 APR.

MAY 21,982 41,983 13,999 59,842 91,886 67,339 83,624 85,326 88,050 71,542 MAY JUNE 10,687 29,597 17,236 23,070 36,404 29,060 34,560 77,967 46,614 28,235 JUNE JULY 6,968 14,581 9,636 18,514 10,700 10,852 25,217 20,536 35,508 18,210 JULY AUG. 5,627 7,015 7,460 22,312 7,014 5,062 19,829 17,327 17,174 12,097 AUG.

SEPT. 3,214 15,548 4,581 11,528 4,371 5,478 29,930 8,009 12,504 5,165 SEPT.

OCT. 6,484 8,983 3,013 35,598 15,460 9,451 37,590 21,111 5,170 6,556 OCT.

NOV. 12,527 24,881 7,169 41,451 48,154 10,102 63,944 15,167 23,717 25,287 NOV.

DEC. 11,338 41,175 23,552 51,607 12,581 24,029 53,393 12,406 17,593 37,615 DEC.

YEARLY 28,788 39,610 22,528 39,242 43,797 29,749 51,319 37,762 *37,575 39,068 YEARLY

• wtd. avg.

CHAPTER 02 2.4-45 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.5 (C0ntinued)

MAXIMUM AVERAGE DAILY FLOW (cfs) 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 JAN. 234,000 141,175 133,475 218,075 170,750 57,725 152,075 24,300 124,500 72,600 JAN.

FEB. 102,150 125,225 172,650 137,800 95,650 106,575 98,700 101,975 61,500 116,900 FEB.

MAR. 68,775 300,825 103,675 343,550 225,900 234,525 180,225 336,900 95,900 152,600 MAR.

APR. 91,025 226,325 269,975 196,850 100,150 117,325 72,725 221,900 255,600 284,400 APR.

MAY 53,450 63,475 49,400 171,375 129,050 158,525 57,050 98,000 62,500 185,000 MAY JUNE 28,100 73,450 83,875 65,075 170,600 52,175 29,700 42,300 19,400 44,100 JUNE JULY 23,425 16,825 33,075 22,000 13,700 10,025 8,250 40,400 14,600 32,900 JULY AUG. 9,375 36,150 12,850 14,100 10,100 7,750 123,875 55,500 6,100 28,500 AUG.

SEPT. 13,600 49,200 15,425 46,225 8,800 9,875 19,350 22,300 6,200 25,300 SEPT.

OCT. 11,875 68,075 7,375 6,825 6,800 43,350 264,500 32,900 7,600 26,300 OCT.

NOV. 17,925 430,025 33,325 177,025 18,525 42,475 125,725 144,100 16,000 36,500 NOV.

DEC. 77,500 297,350 73,875 204,925 45,775 79,275 35,050 133,000 136,700 35,600 DEC.

MINIMUM AVERAGE DAILY FLOW (cfs) 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 JAN. 37,950 27,675 22,900 34,350 18,600 4,025 8,025 9,175 10,300 13,800 JAN.

FEB. 32,875 27,875 51,425 20,150 31,750 10,825 7,625 15,350 22,700 10,100 FEB.

MAR. 24,525 10,900 56,825 21,025 36,925 34,250 53,050 51,300 37,200 41,300 MAR.

APR. 31,475 37,250 43,700 49,350 43,525 30,325 28,925 48,400 41,600 73,400 APR.

MAY 16,300 29,700 15,500 28,475 37,450 18,425 9,450 23,800 17,700 20,600 MAY JUNE 7,100 12,525 11,725 9,350 11,475 9,200 7,700 17,300 9,300 14,500 JUNE JULY 6,575 10,800 12,475 6,925 5,500 3,400 2,925 15,800 4,900 10,800 JULY AUG. 4,325 4,475 5,250 6,675 3,375 3,400 2,500 9,700 3,200 9,900 AUG.

SEPT. 4,725 7,600 3,650 5,575 2,650 3,150 3,875 10,300 2,600 5,700 SEPT.

OCT. 6,025 7,100 3,450 4,000 3,050 3,050 8,300 9,500 3,900 6,900 OCT.

NOV. 7,500 12,650 9,475 3,675 3,725 7,825 28,150 17,000 4,200 14,900 NOV.

DEC. 10,325 16,400 14,500 19,550 10,525 16,075 8,900 16,300 7,300 10,900 DEC.

AVERAGE DAILY FLOW (cfs) 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 JAN. 94,809 60,907 71,649 93,910 64,433 14,826 41,751 14,366 37,684 37,623 JAN.

FEB. 62,086 55,354 91,358 56,384 49,443 43,151 31,255 51,056 38,150 23,368 FEB.

MAR. 41,314 76,879 75,547 94,203 76,886 67,445 104,589 101,758 55,552 78,890 MAR.

APR. 55,788 90,644 90,294 95,460 64,520 53,887 42,253 102,113 105,260 140,150 APR.

MAY 34,927 43,733 25,977 71,523 68,586 56,727 20,454 53,023 30,600 74,297 MAY JUNE 12,464 34,334 28,825 22,797 44,892 23,213 15,068 24,457 12,677 25,353 JUNE JULY 11,059 13,754 18,684 14,010 9,197 6,650 5,443 26,165 7,823 19,613 JULY AUG. 6,215 12,811 8,679 9,699 6,263 5,010 24,233 21,513 4,451 14,945 AUG.

SEPT. 7,170 20,048 6,270 13,755 5,076 5,618 9,011 16,673 4,133 11,380 SEPT.

OCT. 8,185 20,828 5,296 5,447 4,125 10,945 57,728 16,777 5,187 12,639 OCT.

NOV. 11,135 72,423 22,347 27,875 8,188 19,278 52,547 36,328 8,993 23,400 NOV.

DEC. 32,948 92,252 39,743 53,692 25,895 34,842 19,433 61,752 43,552 18,832 DEC.

YEARLY 31,365 49,404 40,389 46,563 35,625 28,466 35,089 43,832 29,505 40,041 YEARLY CHAPTER 02 2.4-46 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.5 (C0ntinued)

MAXIMUM AVERAGE DAILY FLOW (cfs) 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 JAN. 213,500 105,000 13,800 77,100 44,300 166,600 38,500 37,800 67,800 26,600 59,900 JAN.

FEB. 112,200 132,500 385,900 109,800 21,300 62,400 106,400 234,900 53,200 109,300 69,200 FEB.

MAR. 93,800 155,400 262,400 147,100 232,900 470,100 66,400 152,800 176,300 192,800 88,900 MAR.

APR. 174,600 377,900 226,800 252,100 151,200 136,400 68,200 76,000 146,300 62,100 123,600 APR.

MAY 120,100 138,100 92,000 47,300 50,600 179,000 45,500 86,600 102,200 134,700 57,600 MAY JUNE 22,500 118,600 39,100 12,000 31,900 17,500 18,100 31,100 31,300 133,700 41,500 JUNE JULY 10,000 23,000 23,300 5,900 10,700 10,000 7,900 6,700 23,700 63,600 41,100 JULY AUG. 8,500 21,800 20,800 9,800 7,700 7,300 6,500 6,100 39,300 9,300 35,600 AUG.

SEPT. 19,900 56,700 17,300 7,500 7,700 3,800 7,500 8,400 23,100 39,900 9,800 SEPT.

OCT. 61,600 14,300 6,200 45,300 3,900 4,300 14,400 9,300 70,500 12,200 6,800 OCT.

NOV. 162,200 14,600 24,000 60,100 12,700 7,000 17,400 66,300 94,500 12,880 55,500 NOV.

DEC. 155,800 12,300 24,400 41,000 36,800 22,300 21,700 63,000 72,300 80,800 97,600 DEC.

MINIMUM AVERAGE DAILY FLOW (cfs) 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 JAN. 9,600 22,300 7,800 10,400 7,500 8,200 8,300 4,900 7,400 11,400 14,900 JAN.

FEB. 22,200 19,700 7,600 11,700 10,400 13,200 8,400 6,100 9,100 12,200 15,500 FEB.

MAR. 23,100 18,100 55,000 30,100 10,100 14,000 23,400 42,700 14,900 12,500 8,900 MAR.

APR. 33,000 28,500 45,100 35,600 24,600 44,900 36,100 20,900 37,300 15,600 34,600 APR.

MAY 14,200 20,300 25,000 11,000 18,900 11,900 11,400 32,000 30,400 18,800 20,000 MAY JUNE 7,000 23,600 17,400 5,700 8,000 6,100 4,600 3,100 12,400 22,200 10,800 JUNE JULY 5,600 7,900 9,500 2,900 5,000 3,800 2,500 2,700 10,400 7,700 5,200 JULY AUG. 3,300 6,200 6,700 2,700 2,900 2,400 2,400 2,200 8,400 3,300 6,000 AUG.

SEPT. 2,600 5,800 4,200 2,400 2,300 1,400 3,000 1,800 6,200 3,900 2,800 SEPT.

OCT. 4,700 7,000 3,300 7,300 1,600 1,800 6,000 3,400 7,600 4,200 3,200 OCT.

NOV. 21,400 8,100 3,400 9,500 1,900 1,500 6,400 3,500 25,000 8,900 4,500 NOV.

DEC. 27,400 2,800 9,000 8,100 7,100 3,000 11,000 11,700 23,100 12,100 10,200 DEC.

AVERAGE DAILY FLOW (cfs) 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 JAN. 41,577 49,619 10,697 30,055 21,021 44,900 18,300 17,400 19,745 18,500 22,600 JAN.

FEB. 42,875 49,924 64,217 27,104 15,839 29,200 43,100 53,400 29,646 40,500 27,400 FEB.

MAR. 56,009 27,955 98,026 84,139 105,006 132,500 40,600 73,300 80,094 55,300 27,900 MAR.

APR. 75,853 127,766 110,900 111,373 51,410 70,100 54,500 33,700 61,127 33,500 56,800 APR.

MAY 36,177 75,448 53,819 24,223 31,313 47,800 27,700 54,097 63,044 217,060 32,900 MAY JUNE 11,806 49,083 25,197 9,123 18,350 10,500 9,400 15,600 18,030 22,500 19,200 JUNE JULY 7,380 15,493 13,903 4,010 6,797 6,000 3,900 11,400 14,684 18,200 14,900 JULY AUG. 5,542 14,252 12,303 4,587 4,548 4,200 4,300 3,400 20,674 6,500 18,000 AUG.

SEPT. 6,717 22,970 8,017 4,083 3,973 2,300 4,300 4,900 10,020 13,600 6,300 SEPT.

OCT. 17,413 9,613 4,313 17,897 2,639 2,900 9,700 5,600 25,842 6,760 5,000 OCT.

NOV. 40,883 11,097 8,767 29,123 6,597 3,200 10,400 10,800 42,007 41,700 25,900 NOV.

DEC. 69,545 7,977 14,548 20,026 18,565 8,200 15,000 29,500 46,290 32,800 31,100 DEC.

YEARLY 34,315 38,433 35,392 30,479 23,838 30,150 20,100 26,091 35,934 42,243 24,000 YEARLY CHAPTER 02 2.4-47 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.5 (C0ntinued)

MAXIMUM AVERAGE DAILY FLOW (cfs) 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 JAN. 28,500 48,100 69,800 92,300 122,700 125,600 167,000 15,300 211,100 260,500 47,500 JAN.

FEB. 164,400 199,300 50,200 204,200 102,600 369,300 239,300 125,100 88,200 213,800 17,000 FEB.

MAR. 145,900 218,300 319,700 152,300 126,500 159,700 119,700 207,000 271,300 444,000 215,200 MAR.

APR. 335,700 99,300 225,600 163,000 200,200 74,100 89,700 222,100 168,800 91,200 198,700 APR.

MAY 66,200 77,400 139,500 86,600 88,700 106,900 49,900 49,300 223,600 99,900 96,700 MAY JUN. 35,300 24,300 969,400 66,200 24,800 92,600 118,600 17,200 38,500 64,900 23,500 JUN JUL. 57,000 11,400 165,000 47,300 64,300 34,600 34,600 27,600 24,300 16,900 17,500 JUL.

AUG. 17,700 39,400 16,400 25,500 20,400 13,300 41,000 16,600 38,500 28,600 10,200 AUG.

SEPT. 12,500 13,400 8,800 34,500 42,300 583,300 17,200 150,600 17,700 77,400 8,400 SEPT.

OCT. 47,500 22,900 9,600 39,000 15,300 142,900 243,300 171,500 16,400 109,000 10,900 OCT.

NOV. 139,200 39,600 121,800 56,000 37,800 78,900 72,900 156,300 18,400 161,400 26,100 NOV.

DEC. 56,500 147,300 212,000 201,400 116,400 47,900 46,000 163,500 60,300 99,800 26,000 DEC.

MINIMUM AVERAGE DAILY FLOW (cfs) 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 JAN. 12,500 13,300 31,700 24,400 32,400 30,400 15,900 7,700 29,000 24,800 12,500 JAN.

FEB. 28,300 11,600 16,500 22,500 23,000 21,100 36,000 7,400 19,100 13,500 5,900 FEB.

MAR. 27,400 42,100 54,600 19,300 38,900 38,400 37,400 69,700 15,200 53,100 6,900 MAR.

APR. 71,900 29,400 45,200 34,900 30,600 30,300 22,700 25,400 35,100 34,500 37,500 APR.

MAY 25,000 23,900 27,200 37,600 21,700 28,800 20,400 10,800 24,200 18,100 20,800 MAY JUNE 12,100 7,200 25,200 22,500 11,400 21,600 17,800 8,400 14,900 9,000 10,300 JUNE JULY 11,300 5,300 18,100 11,400 8,300 13,000 13,400 9,600 8,500 7,600 6,100 JULY AUG. 5,800 4,200 7,900 8,000 5,200 5,800 10,200 8,100 7,500 9,000 4,600 AUG.

SEPT. 3,500 5,200 4,900 6,700 9,500 10,600 4,900 4,400 5,700 11,400 2,800 SEPT.

OCT. 6,300 4,700 5,100 6,900 4,200 24,600 16,000 35,200 6,900 21,100 2,200 OCT.

NOV. 19,400 9,600 7,000 12,100 6,900 22,000 16,000 26,700 8,200 19,700 4,400 NOV.

DEC. 30,800 27,200 46,200 32,500 26,000 23,300 12,600 29,900 16,300 19,400 6,000 DEC.

AVERAGE DAILY FLOW (cfs) 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 JAN. 18,700 27,100 44,300 49,000 69,500 51,600 47,800 10,990 83,100 97,100 25,700 JAN.

FEB. 67,200 72,300 30,600 60,500 45,600 81,200 97,000 23,330 33,500 44,900 11,900 FEB.

MAR. 50,300 99,700 108,300 62,000 58,800 78,000 61,000 120,800 110,400 135,800 68,000 MAR.

APR. 132,800 60,500 87,100 77,200 89,200 47,400 41,500 82,600 89,200 61,000 101,500 APR.

MAY 41,200 43,800 68,900 57,900 38,200 55,900 32,800 27,400 79,200 41,500 44,800 MAY JUNE 20,400 14,800 179,800 36,100 18,600 42,300 36,300 11,300 26,000 24,800 16,700 JUNE JULY 20,400 7,300 60,900 21,100 20,500 20,300 23,400 17,500 14,000 12,000 10,600 JULY AUG. 10,600 14,300 12,200 13,800 9,900 9,600 19,500 12,000 15,800 15,000 7,800 AUG.

SEPT. 8,060 10,500 7,000 15,600 20,100 81,400 11,900 32,100 10,400 28,300 4,300 SEPT.

OCT. 17,400 10,700 7,200 13,100 10,900 64,300 77,700 69,900 10,800 45,900 4,600 OCT.

NOV. 56,000 17,600 53,200 25,700 21,900 39,600 34,700 63,400 12,800 46,300 9,900 NOV.

DEC. 41,000 57,000 101,000 86,300 51,400 35,300 23,800 85,700 30,200 41,600 15,500 DEC.

YEARLY 40,338 36,300 63,375 43,190 37,880 50,575 42,280 63,910 42,950 49,520 26,775 YEARLY SOURCE: Conowingo Hydroelectric Station Flow Records.

CHAPTER 02 2.4-48 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.6 MINIMUM AVERAGE 7-DAY FLOWS AT CONOWINGO FOR THE VARIOUS MONTHS OF THE YEAR (With 1-day overlap into adjacent month)

Minimum 7-Day Natural Year of River Flows at Conowingo Month Minimum Period of Minimum (cfs)

January 1931 January 22 to 28 4,604 February 1931 February 5 to 11 5,136 March 1901 February 28 to March 6 7,840 April 1946 April 25 to May 1 15,468 May 1941 May 26 to June 1 9,150 June 1965 June 25 to July 1 5,086 July 1965 July 25 to 31 2,900 August 1966 August 26 to September 1 2,686 September 1964 September 13 to 19 1,871 October 1963 October 25 to 31 2,329 November 1964 November 17 to November 23 2,357 December 1930 November 30 to December 6 2,918 CHAPTER 02 2.4-49 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.7 DAMS AND RESERVOIRS ON TRIBUTARIES OF THE SUSQUEHANNA RIVER Drainage Flood Area Storage Height Name of Dam Name of Tributary Purpose Owner (sq mi) (acre-ft) (ft)

COMPLETE AND IN OPERATION Indian Rock Cadorus Cr. Flood C. USA 94 28,000 83 Stevenson First Fork Cr. Flood C. Penna. 243 78,950 167 Almond Canacadea Flood C. USA 56 14,800 90 Arkport Canisteo R. Flood C. USA 31 7,900 113 Whitney Pt. Otselio R. Flood C. USA 255 86,440 95 East Sidney Ouleout Cr. Flood C. USA 102 33,500 146 Bush Kettle Cr. Flood C. USA 226 75,000 165 Stillwater Lackawanna R. Flood C. USA 36.8 11,800 77 Curwensville West Branch Flood C. USA 365 118,500 131 Aylesworth Aylesworth Cr. Flood C. USA 6.2 1,900 85.5 Sayers Bald Eagle Cr. Flood C. USA 339 99,000 100 Tioga Tioga R. Flood C. USA 280 125,000* 125 Hammond Crooked Cr. Flood C. USA 122 125,000* 107 Raystown Raystown Bra. Flood C. USA 960 225,000 225 PARTIALLY COMPLETE Cowanesque Cowanesque R. Flood C. USA 299 95,700 145 AUTHORIZED - NOT STARTED Copes Corner Butternut Cr. Flood C. USA 118 37,900 75 Davenport Center Charlotte Cr. Flood C. USA 164 52,500 100 Genegantslet Genegantslet Cr. Flood C. USA 95 30,200 104 S. Plymouth Canasawacta Flood C. USA 58 18,500 125 West Oneonta Otega Cr. Flood C. USA 108 34,500 86 Fall Brook Fall Brook Flood C. USA 4.1 1,400 67 NOTE: Under study, but not authorized, are many dams which are part of a comprehensive study of water resources development for the Susquehanna River Basin by the U.S. Army Corps of Engineers.

• Combined reservoir because of connecting channel through saddle in ridge separating the Tioga River and Crooked Creek Basin.

CHAPTER 02 2.4-50 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.8 MAXIMUM CONCENTRATION IN CONOWINGO POND FROM A ONE-MILLICURIE/DAY STEADY-STATE DISCHARGE FROM PEACH BOTTOM UNITS 2 AND 3*

(Based on modelling described in Section 2.4.3.3)

Average Peach Bottom Peach Bottom Conowingo River Cooling Water Cooling Water Chester Baltimore Discharge Flow Intake Discharge Water Intake Water Intake (Average)

(cfs) (Ci/cc) (Ci/cc) (Ci/cc) (Ci/cc) (Ci/cc) 2,500 2.2 x 10-10 3.5 x 10-10 1.6 x 10-10 1.6 x 10-10 1.6 x 10-10 5,000 1.1 x 10-10 2.3 x 10-10 0.8 x 10-10 0.8 x 10-10 0.8 x 10-10 10,000 0.6 x 10-10 1.8 x 10-10 0.5 x 10-10 0.5 x 10-10 0.4 x 10-10 15,000 0 1.2 x 10-10 0.4 x 10-10 0.4 x 10-10 0.3 x 10-10 25,000 0 1.2 x 10-10 0.20 x 10-10 0.17 x 10-10 0.16 x 10-10 50,000 0 1.2 x 10-10 0.14 x 10-10 0.13 x 10-10 0.08 x 10-10 100,000 0 1.2 x 10-10 0.04 x 10-10 0.08 x 10-10 0.04 x 10-10 150,000 0 1.2 x 10-10 0.01 x 10-10 0.06 x 10-10 0.03 x 10-10

• Based on a condenser circulating water flow of 3,350 cfs (1,500,000 gpm) with all six circulating water pumps operating.

CHAPTER 02 2.4-51 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.9 MAXIMUM CONCENTRATION RESULTING FROM AN ARBITRARY ONE-CURIE SLUG RELEASE INTO THE PEACH BOTTOM DISCHARGE CANAL*

(Based on modelling described in Section 2.4.3.3)

Peach Bottom Cooling Water Intake Chester Water Intake Average River Maximum Time of Maximum Time of Flow Concentration Maximum Concentration Concentration Maximum Concentration (cfs) (Ci/cc) (hr after release) (Ci/cc) (hr after release) 2,500 2.5 x 10-8 12 1.4 x 10-8 144 5,000 2.0 x 10-8 12 6.6 x 10-9 70 10,000 1.0 x 10-8 12 3.1 x 10-9 33 15,000 0 - 2.0 x 10-9 21 25,000 0 - 1.0 x 10-9 11 50,000 0 - 3.0 x 10-9 4 100,000 0 - 0 -

150,000 0 - 0 -

Baltimore Water Intake Conowingo Powerhouse Tailrace Average River Maximum Time of Maximum Time of Flow Concentration Maximum Concentration Concentration Maximum Concentration (cfs) (Ci/cc) (hr after release) (Ci/cc) (hr after release) 2,500 0.7 x 10-9 208 5.0 x 10-10 193 5,000 0.8 x 10-9 110 8.0 x 10-10 100 10,000 0.8 x 10-9 61 1.3 x 10-9 53 15,000 0.9 x 10-9 45 1.8 x 10-9 38 25,000 1.1 x 10-9 31 2.3 x 10-9 25 50,000 1.4 x 10-9 22 5.2 x 10-9 16 100,000 2.1 x 10-9 17 1.0 x 10-8 12 150,000 2.9 x 10-9 15 1.5 x 10-8 10

• Based on a condenser circulating water flow of 3350 cfs (1,500,000 gpm) with all six circulating water pumps operating.

CHAPTER 02 2.4-52 REV. 25, APRIL 2015

PBAPS UFSAR TABLE 2.4.10 TIME IN DAYS AFTER RELEASE TO REACH VARIOUS CONCENTRATIONS FOR AN ARBITRARY ONE-CURIE SLUG RELEASE FROM THE PEACH BOTTOM DISCHARGE*

(Based on modelling described in Section 2.4.3.3)

Average Peach Bottom Cooling Water Intake Chester Water Intake River (Concentration - Ci/cc) (Concentration - Ci/cc)

Flow (cfs) 2.8 x 10-9 1.4 x 10-9 2.8 x 10-10 2.8 x 10-11 2.8 x 10-9 1.4 x 10-9 2.8 x 10-10 2.8 x10-11 2,500 13 47 142 277 7 47 142 277 5,000 10 27 75 142 7 27 75 142 10,000 7 17 41 75 7 17 41 75 15,000 - - - - - 8 21 47 25,000 - - - - - - 10 25 50,000 - - - - - - 0.3 8 100,000 - - - - - - - -

150,000 - - - - - - - -

Average Baltimore Water Intake Conowingo Powerhouse Tailrace River (Concentration - Ci/cc) (Concentration - Ci/cc)

Flow (cfs) 2.8 x 10-9 1.4 x 10-9 2.8 x 10-10 2.8 x 10-11 2.8 x 10-9 1.4 x 10-9 2.8 x 10-10 2.8 x10-11 2,500 - - 152 287 - - 152 287 5,000 - - 85 152 - - 85 152 10,000 - - 51 85 - - 51 85 15,000 - - 33 55 - 18 33 55 25,000 - - 19 31 - 11 19 31 50,000 - 0.9 8 13 3 5.5 8 13 100,000 - 0.9 2.8 4.5 1.2 2.8 3 4.5 150,000 - 0.8 1.0 1.5 0.6 0.7 1.0 1.5

• If 1 Ci were uniformly mixed with the entire static volume of Conowingo Pond at mean water elevation, a concentration of about 2.8 x 10-9 Ci/cc would result. No credit for radioactive decay has been included.

CHAPTER 02 2.4-53 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.11 CHRONOLOGICAL LIST OF FLOODS PEAK DISCHARGES FOR SUSQUEHANNA RIVER AT HARRISBURG, PA.

Discharge Discharge Year Date (cfs) Year Date (cfs) 1786 Oct. 5 482,000 1925 Feb. 13 379,000 1846 Mar. 15 482,000 1926 Nov. 17 323,000 1865 Mar. 18 573,000 1927 Mar. 23 208,000 1868 Mar. 19 417,000 1928 May 2 252,000 1886 Jan. 6 385,000 1929 Mar. 17 235,000 1889 June 2 654,000 1930 Feb. 28 177,000 1891 Feb. 19 408,000 1931 Mar. 31 153,000 1892 April 5 270,000 1932 April 2 245,000 1893 May 5 324,000 1933 Aug. 25 269,000 1894 May 22 613,000 1934 Dec. 2 242,000 1895 April 11 230,000 1935 July 11 187,000 1896 April 1 265,000 1936 Mar. 19 740,000 1897 Mar. 26 180,000 1937 Jan. 24 231,000 1898 Mar. 24 315,000 1938 Dec. 20 178,000 1899 Mar. 6 228,000 1939 Feb. 23 210,000 1900 Mar. 2 238,000 1940 April 2 418,000 1901 Nov. 28 249,000 1941 April 7 244,000 1902 Mar. 3 449,000 1942 May 24 290,000 1903 Mar. 2 276,000 1943 Jan. 1 412,000 1904 Mar. 8 298,000 1944 May 9 212,000 1905 Mar. 21 306,000 1945 Mar. 5 252,000 1905 Dec. 4 210,000 1946 May 29 494,000 1907 Mar. 15 247,000 1947 April 7 214,000 1908 Mar. 20 297,000 1948 April 16 308,000 1909 May 2 297,000 1949 Jan. 1 220,000 1910 Mar. 3 332,000 1950 Nov. 27 416,000 1911 Jan. 16 178,000 1951 April 1 266,000 1912 April 4 249,000 1952 Mar. 13 324,000 1913 Mar. 28 402,000 1953 Mar. 26 216,000 1914 Mar. 30 358,000 1954 Mar. 3 242,000 1915 Feb. 26 286,000 1955 Mar. 6 177,000 1916 Mar. 29 379,000 1956 Mar. 10 338,000 1917 Mar. 29 155,000 1957 April 7 250,000 1918 Mar. 16 288,000 1958 April 9 281,000 1919 May 23 294,000 1959 Jan. 24 230,000 1920 May 13 423,000 1960 April 2 382,000 1921 Nov. 30 278,000 1961 Feb. 27 392,000 1922 Mar. 9 192,000 1962 April 2 270,000 CHAPTER 02 2.4-54 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.4.11 (Continued)

Discharge Discharge Year Date (cfs) Year Date (cfs) 1923 Mar. 6 261,000 1963 Mar. 28 249,000 1924 April 8 324,000 1964 Mar. 12 484,000 1965 Feb. 11 136,000 1973 Feb. 4 209,000 1966 Feb. 15 265,000 1974 Dec. 29 205,000 1967 Mar. 17 182,000 1975 Sept. 27 529,000 1968 Mar. 24 202,000 1976 Feb. 19 239,000 1969 April 8 127,000 1977 Oct. 10 254,000 1970 April 4 343,000 1978 Mar. 24 252,000 1971 Mar. 1 224,000 1979 Mar. 7 416,000 1972 June 24 1,020,000 1980 Mar. 23 205,000 CHAPTER 02 2.4-55 REV. 21, APRIL 2007

PBAPS UFSAR 2.5 GEOLOGY AND SEISMOLOGY 2.5.1 Introduction This subsection presents the geologic and seismologic studies performed by Dames & Moore. The site is located adjacent to and west of the Conowingo Pond in Peach Bottom Township, York County, Pennsylvania, approximately 2 1/2 mi north of the Pennsylvania-Maryland state line. Conowingo Pond is formed by the backwater of Conowingo Dam located on the Susquehanna River approximately 9 mi downstream from the site. The location of the site with respect to surrounding topographical features is shown in Drawing C-1.

The geologic and seismologic studies which were performed to develop data for site evaluation purposes are described in this subsection. The results of these studies were used in formulating the conclusions regarding site suitability which are presented in paragraphs 2.5.2 and 2.5.3.

2.5.1.1 Field Explorations Field explorations of the site and environs were performed by Dames and Moore. The field investigation program consisted of the following:

1. A test boring program

2. A geologic survey of the site and surrounding area

3. Geophysical surveys

4. Micromotion measurements.

2.5.1.1.1 Test Borings More than 100 test borings were drilled. Undisturbed soil samples of the overburden and NX-size cores of the underlying rock were extracted from the borings and subjected to appropriate laboratory tests to evaluate the physical properties of the soil and underlying rock.

The drilling program is discussed in subsection 2.7, "Foundation Analysis," and representative boring logs are shown in Figures 2.7.2 through 2.7.9.

CHAPTER 02 2.5-1 REV. 21, APRIL 2007

PBAPS UFSAR 2.5.1.1.2 Geologic Survey The geologic features of the site and its environs were studied by Dames and Moore. The geologic studies included geologic mapping of the site, geologic reconnaissance of the site and its environs, a study of the surface water and ground water conditions of the site and surrounding area, a literature research, and interviews with prominent local geologists.

2.5.1.1.3 Seismic Refraction Survey A seismic refraction survey was undertaken to evaluate the depth to bedrock, the compressional wave velocities in the bedrock, and the compressional wave velocities in the soil overburden.

Dynamite blasts near each end of the profile line were used as an energy source. The velocities obtained reflect the variations in local topography and subsurface stratification at the site.

2.5.1.1.4 Micromotion Measurements Micromotion measurements were made with an instrument that measures the ambient background motion at the site and its response to natural vibration generators, such as wind and waves.

The data obtained are useful in evaluating the dynamic properties of the subsurface materials. The magnitude of movement in the bedrock at the site was so small that no discernible data were obtained. This absence of measurable ground vibrations usually occurs when relatively sound rock is present at shallow depths below the ground surface.

2.5.1.2 Laboratory Tests Representative rock cores extracted from the test borings were subjected to a comprehensive laboratory testing program to evaluate the physical characteristics of the rock encountered at the site. Laboratory tests included:

1. Unconfined compression tests

2. Tensile tests

3. Shockscope tests.

CHAPTER 02 2.5-2 REV. 21, APRIL 2007

PBAPS UFSAR 2.5.1.2.1 Unconfined Compression Tests The strength of the underlying rock formation was evaluated by subjecting representative rock samples to unconfined compression tests. The results of several unconfined compression tests are shown on some of the boring logs, Figures 2.7.4, 2.7.5, 2.7.6, 2.7.7, and 2.7.9.

2.5.1.2.2 Tensile Tests Standard tensile tests were performed by subjecting selected rock samples to an axial tensile load. A uniform rate of loading was applied until failure occurred. The results of some of the tensile tests are presented in Table 2.5.1.

2.5.1.2.3 Shockscope Tests In the shockscope tests performed, the samples are subjected to a physical shock under a range of confining pressures, and the time necessary for the shock wave to travel the length of the sample is measured using an oscilloscope. The velocity of compressional wave propagation is then computed. Since this velocity is proportional to the dynamic modulus of elasticity of the sample, the data also are used in evaluating dynamic elastic properties.

The results of the tests are presented in Table 2.5.2.

2.5.2 Geology 2.5.2.1 Introduction This subsection presents the results of the geologic studies performed by Dames and Moore for the PBAPS. Descriptions and the results of the field explorations and laboratory tests performed in conjunction with the geologic studies are presented in paragraph 2.5.1.

2.5.2.1.1 Summary The results of the geologic studies subsequently presented may be summarized as follows:

1. The geology of the region is relatively complex, making specific stratigraphic and structural relationships somewhat conjectural.

CHAPTER 02 2.5-3 REV. 21, APRIL 2007

PBAPS UFSAR

2. Bedrock at the site is the Peters Creek schist, a metamorphosed sedimentary rock of Precambrian or early Paleozoic age. Overburden is a residual sandy silt and gravel derived by weathering of the underlying schist.

Zones of highly weathered rock separate the overburden and the fresh hard rock.

3. No active fault is known or suspected in the vicinity of the site. Known faults in the area have been inactive for at least 140 million yr.

4. Adequate foundation support for major structures is available from the Peters Creek formation. Lighter structures can be adequately supported in the overburden.

5. There is no geologic feature of the site or surrounding area which adversely affects the intended use of the site.

2.5.2.1.2 Geological Program The geologic program of investigation conducted for the site included:

1. A thorough review of pertinent geological literature (published and unpublished) and interviews with university, state, and federal geologists.

2. A thorough geologic survey and analysis of the site and surrounding area including interpretation of maps and aerial photographs.

3. An investigation of subsurface soil, rock, and ground water conditions by means of a test boring program, geophysical surveys, and other related field studies.

The results of the geological investigation are described in the following paragraphs.

2.5.2.2 Regional Geology 2.5.2.2.1 Physiography The site lies within the Piedmont Upland Section of the Piedmont Physiographic Province of the Appalachian Highlands. The northeast-southwest trending Piedmont Province is an eroded CHAPTER 02 2.5-4 REV. 21, APRIL 2007

PBAPS UFSAR plateau of low relief and rolling topography. The surface of the plateau slopes to the southeast. The Piedmont is divided into an upland and a lowland section. The upland section is underlain by metamorphosed sedimentary and crystalline rocks of Paleozoic and Precambrian age. The rocks are relatively resistant to erosion and support an uneven hilly surface. The higher hills are capped by Cambrian quartzites and Precambrian crystalline rocks, while broad valleys characterize areas underlain by limestone and calcareous shales. The less rugged lowland section to the north and west of the Piedmont uplands is formed largely on relatively soft shales and sandstones of Triassic age.

In Pennsylvania, the upland section occupies the southeastern portion of the state, extending northward from the Maryland-Pennsylvania border a maximum of 30 mi.

The Triassic Lowland Section of the Piedmont Province, located approximately 30 mi north of the site, is about 10 mi wide and trends diagonally across the southeastern portion of the state.

Ridges in the Triassic lowland trend northeast-southwest along the strike of the more resistant bedrock formations. Higher and more rugged terrain exists where these formations have been intruded by diabase dikes and sills.

The Fall Zone, which represents the physiographic boundary between the Piedmont Province and the Atlantic Coastal Plain Province, is located about 20 mi southeast of the site at its closest approach.

2.5.2.2.2 Stratigraphy The bedrock in the northern provinces of the Appalachian Highlands is primarily unmetamorphosed sedimentary rocks which range in age from Cambrian to Pennsylvanian. The Triassic Lowland Section contains unmetamorphosed sandstones, shales, and conglomerates that have been intruded by igneous sills and dikes. A series of Ordovician, Cambrian, and Precambrian limestones, quartzites, and schists occur in the Conestoga Valley Section of the Piedmont Province between the Triassic lowland and Piedmont upland.

The rocks of the Piedmont upland are of Precambrian and Early Paleozoic age and are known collectively as the Glenarm Series.

They are metamorphosed sedimentary rocks and include, in order of decreasing age, the Wissahickon and Peters Creek schists, Cardiff conglomerate, and Peach Bottom slate.

CHAPTER 02 2.5-5 REV. 21, APRIL 2007

PBAPS UFSAR 2.5.2.2.3 Structure The rocks of the Piedmont Province are highly folded and often faulted. Folding and faulting have been mapped in the northern part of the Pennsylvania Piedmont where the complex structural conditions are exposed. Toward the southern part of the Piedmont, structural relationships are not as well known because of the much higher degree of metamorphism. However, the structural trends can be traced from the north and northeast into the general vicinity of the site and further southward.

The dominant structural feature of the region is the Regional Appalachian Orogenic Belt. This belt is marked by the northeast-southwest orientation of the axes and lineation of most of the structural features and stratigraphic contacts.

Two major fault systems are prevalent in the region: faults of Paleozoic age or older, and faults of Triassic age. The Paleozoic faults are largely thrust faults and occurred during early Paleozoic regional metamorphism or during the late Paleozoic Appalachian Orogeny. The thrust sheets are relatively thin and generally exhibit movement to the northwest. The north-south trending faults at their flanks are tears. These faults do not involve younger Mesozoic or Cenozoic strata and are completely healed.

In the Piedmont uplands, some of the major thrust faults are transected by Triassic age diabase dikes which show no displacement. Similar relationships of Triassic dikes crossing Paleozoic faults are found in the Reading Prong area north of the site. Based on the absence of displacement of the Triassic diabase dikes, it is evident that the last movement along these faults occurred probably 200 million yr ago and certainly no later than 140 million yr ago.

The Triassic faults are normal or strike slip faults that occurred during late Triassic or early Jurassic times. Most of these faults are located near the Triassic lowlands, about 30 mi from the site, and are of limited significance.

A zone of Paleozoic faults trending through the vicinity of the Peach Bottom site has been inferred. One of these faults is associated with the Peach Bottom Syncline, the closest structure to the site. The syncline is a narrow, tightly folded structure which trends in a northeast-southwest direction. Its axis, and that of its associated fault, is located approximately 1 mi south of the site.

CHAPTER 02 2.5-6 REV. 21, APRIL 2007

PBAPS UFSAR Other faults, with traces roughly parallel to that of the Peach Bottom fault, have been mapped to the northwest and southeast of the site. The closest of these mapped faults lies approximately 4 mi from the site.

Studies indicate that the Peach Bottom fault, and the similar nearby faults, have been completely healed.

The most recent fault movement in the region is believed to have occurred during Mesozoic times approximately 140 to 200 million yr ago. Early activity has been traced to the Devonian Period with possible movement as early as late Ordovician times, some 440 to 460 million yr ago.

2.5.2.2.4 Geologic History The history of the Piedmont Province is complex and not completely understood. Intense metamorphic deformation occurred in Precambrian times, approximately one billion years ago.

Sedimentary and igneous rocks were altered and the Baltimore gneiss domes were formed. During late Precambrian time, sediments of the Glenarm Series were deposited in a geosyncline that was developing parallel to the already established regional northeast-southwest trend. The cumulative thickness of the Glenarm sediments is estimated to be 10,000 to 20,000 ft.

The geosyncline containing the Glenarm sediments was deeply downwarped and subjected to intense thrusts originating from the south and southeast. These tectonic forces resulted in regional metamorphism and folding of the Glenarm sediments during late Ordovician time. Simultaneously, the Baltimore gneiss basement was uplifted, subjecting the Glenarm sediments to further deformation and faulting.

Major metamorphism occurred during Late Devonian or Early Mississippian time and most of the presently observed lineations and fabric were imparted to the gneisses and schists of the Glenarm strata. Deep-seated crustal blocks moved from the southeast to the northwest folding the crustal sediments of the Piedmont in this region. This resulted in the attitude change of the beds and schistosity from horizontal in the northwest to vertical or overturned in the southeast. Major faulting and folding occurred during this time.

The last major tectonic movements in the region occurred in late Permian time during the Appalachian Revolution. The Appalachian CHAPTER 02 2.5-7 REV. 21, APRIL 2007

PBAPS UFSAR Mountain system was gently and broadly uplifted and folded. Since that time, the Piedmont Upland Section has been continually subjected to erosion.

Elongated crustal blocks, down-faulted in relation to the surrounding rocks, were formed and filled with sediments during the Triassic period. These areas, called grabens, were subsequently intruded by diabase dikes and sills. No movement along any fault system has been recognized in the region since Triassic time.

Post-Triassic geological history of the Piedmont Province is one of progressive erosion. Since Triassic time, the area has been continuously above sea level and deposition has been restricted to alluvium along some of the larger streams. By the beginning of Cretaceous time, all of the rocks, including the hardest and most resistant, had been eroded to a level gently rolling surface. At the beginning of Tertiary time, this surface was uplifted and subjected to renewed erosion.

2.5.2.3 Site Geology 2.5.2.3.1 General The site is located within the outcrop zone of the Peters Creek schist, the most extensive formation in the area. Younger formations in the surrounding area are the Cardiff conglomerate and the Peach Bottom slate. The most significant structural feature in the site area is the Peach Bottom syncline. The Peach Bottom slate forms the core of the syncline. The Cardiff conglomerate underlies the slate and outcrops around it except on the northwest face.

2.5.2.3.2 Physiography The original site topography was characterized by rugged, heavily wooded terrain. Original elevations ranged from about 400 ft in the western portion of the site to about 110 ft near Conowingo Pond. The ground surface generally sloped rather steeply in an easterly direction toward the river.

The most prominent site features include Unit 1, the Susquehanna River, and Rock Run Creek. Rock Run Creek is a minor tributary of the Susquehanna and is located south of Units 2 and 3.

CHAPTER 02 2.5-8 REV. 21, APRIL 2007

PBAPS UFSAR 2.5.2.3.3 Stratigraphy The site lies within the outcrop zone of the Peters Creek schist.

The Susquehanna River cuts across the regional strike of the bedrock in the Piedmont upland and the Peters Creek schist is exposed for about 12 mi along the banks of the river. The schist extends about 35 mi northeast of the site and 20 mi southwest of the site where it grades into related rocks of the Glenarm Series.

Recent studies of the Piedmont Province suggest that the Peters Creek schist is possibly a sandy member of the Wissahickon formation.

The Cardiff conglomerate and the Peach Bottom slate lie within and comprise the Peach Bottom Syncline. They are quite limited in areal extent and outcrop approximately 1 mi south of the site. The Cardiff conglomerate, which overlies the Peters Creek schist, is a conglomeratic quartzite containing sheared quartz pebbles in a matrix of fine-grained quartz, chlorite, and mica-rich sands. The Peach Bottom slate, which overlies the Cardiff conglomerate, is a fine-grained, blue-black slate with lenses and seams of quartzite.

The slate exhibits strong cleavage.

The site is mantled by residual soils derived by weathering of the underlying schist. These soils are compact and consist of sandy silt and silty sand with gravel. The underlying Peters Creek schist is a greenish-gray to white chlorite schist interbedded with seams and bands of quartzite that range up to 6 ft in thickness.

The upper zone of the bedrock formation has been greatly altered by weathering to essentially a friable material containing ribs of relatively unweathered rock. The interface between the overlying residual soil and the highly weathered rock is transitional.

Although rock structure generally is evident in the highly weathered material, some of it has been destroyed by the weathering process. The zone of severe weathering ranges in thickness from less than 10 ft to more than 60 ft. However, this zone is generally limited to thicknesses of 25 ft or less. The greatest thicknesses of highly weathered rock were encountered in the higher western portion of the construction area.

Below the highly weathered zone the schist becomes harder and fresher. The relatively fresh rock surface was encountered at depths ranging from about 15 ft below original grade, near the Susquehanna River, to greater than 80 ft below grade in the higher CHAPTER 02 2.5-9 REV. 21, APRIL 2007

PBAPS UFSAR western portion of the construction area. Contours of the surface of the relatively fresh rock are shown in Figure 2.7.1.

2.5.2.3.4 Structure The nearest significant structure to the site is the Peach Bottom Syncline. The Peach Bottom Syncline, located approximately 1 mi south of the site, is a narrow, elongated, tightly folded syncline, approximately 16 mi long and with an average width of 1/2 mi. The Peach Bottom slate forms the core of the syncline.

The Cardiff conglomerate underlies the slate and outcrops around it except on the northwest face. The Peach Bottom slate is faulted against the Peters Creek schist for a distance of 9 mi.

The closest approach of this faulting to the site is about 1 mi to the south. The fault has been inactive for at least 140 million yr.

In the site area, the Peters Creek formation is characterized by thin lenticular bedding and strong flow cleavage resulting in a well developed schistosity.

A major cut into the formation was made in conjunction with the plant construction and is shown in Figure 2.7.1. Recent mapping of the schist exposed in this cut indicates that, along the long face of the cut in the vicinity of Units 2 and 3, the predominant strike of the schistosity is between North 55 deg East and North 65 deg East. The strike of the schistosity rotates to about North 35 deg East near the northern end of the cut and to about North 40 deg East near the southern end of the cut. The dip of the schistosity is between 60 and 70 deg to the southeast throughout the site.

The exposed rocks exhibit different jointing patterns on either side of about Plant Coordinate North 1350. The following "major" joint patterns were mapped in the area south of Plant Coordinate North 1350:

Strike Dip North 50 deg West 60 deg (East)

North 20 deg West 67 deg (West)

North 30 deg East Near Vertical North 60 deg West Near Vertical CHAPTER 02 2.5-10 REV. 21, APRIL 2007

PBAPS UFSAR In addition to the joint patterns listed above, other minor features are apparent. Neither the major nor the minor joints appear to be continuous over large areas. The effect of the jointing is to produce numerous, rather small, blocks of rocks.

North of Plant Coordinate North 1350, the principal joint systems are:

Strike Dip North 50 deg West Near Vertical North 80 deg West 0 to 10 deg (North)

Additional minor joint patterns have been mapped, but they are discontinuous and considered to be unimportant.

During early site reviews for Fulton Generating Station in 1978, a previously undetected shear zone and diabase dike were mapped in the vicinity of the Peach Bottom site by Stone & Webster Engineering Company. Investigation and analysis by both Stone &

Webster and Dames & Moore concluded that these geological features were a common occurrence for the region and were of no consequence due to the age of the features. Analysis report was forwarded to the NRC per letter from S. L. Daltroff to J. F. Stolz dated November 30, 1982.

2.5.2.3.5 River Geology The PBAPS is located adjacent to and on the west bank of the Susquehanna River, about 14 mi north of the river's mouth at Chesapeake Bay. The Susquehanna, from its source in Lake Otsego, New York, to the head of Chesapeake Bay is 422 mi long and drains an area of about 27,500 sq mi. Approximately 27,000 sq mi of this area is upriver from Peach Bottom.

The Susquehanna is a transverse river which crosses three different geologic regions distinguished from one another on the basis of age, character, and structure of the rocks and the physiography. These regions are (from north to south) the Appalachian Plateau, the Mountainous Area (which includes the Valley and Ridge, Great Valley, and Blue Ridge Provinces), and the Piedmont.

The quantity of water carried by the river is small in comparison to the size of its valley, the river being in this sense an underfit stream. This is probably due to the fact that at one CHAPTER 02 2.5-11 REV. 21, APRIL 2007

PBAPS UFSAR time during the last period of glacial retreat, drainage from the New York Finger Lakes went chiefly southward through the Susquehanna Valley, producing much larger flows than the river presently carries. These periods of higher flow are thought to be responsible for a stretch of depositional terraces and wide flood plains visible between Falmouth and Columbia, Pennsylvania, about 35 and 23 mi, respectively, upstream of the Peach Bottom site.

Terracing is not evident south of Columbia, probably because of the relatively steep-sided valley cut through the Piedmont uplands in which the site is located.

The course of the river has been largely controlled by variations in the resistance to erosion of the bedrock which it crosses. The lower 35-mi stretch of the river is relatively straight, indicative of the similar types of rock found in this area. Rocky islands in the river, representing isolated areas of more resistant rock, are numerous. The fall of the river in this area is about 4 to 5 ft per mi.

Three dams have been constructed since 1910 in the lower 35 mi of the river. These are, from north to south, the Safe Harbor, Holtwood, and Conowingo Dams. The Peach Bottom site is located 9 mi above Conowingo Dam and 6 mi below Holtwood Dam.

Conowingo Pond, formed by Conowingo Dam, varies in width from about 0.6 to 1.5 mi and is slightly less than 1 1/2 mi wide in the site area. The pond contains about 246,000 acre-feet (82 billion gal) of water. Normal pond elevation is between 104 ft and 109.25 ft C.D. The top 10 ft (80,000 acre-feet) of water in the pond are used as pondage to regulate power generation. River flows at Conowingo Dam, which became operational in 1928, have ranged from a maximum of 972,000 cfs to a minimum of 1,400 cfs, averaging 37,400 cfs. This flow represents about 18 in of runoff from the basin out of an average area rainfall of approximately 40 in annually.

The depth of water near and upstream of the site area is variable, but averages about 12 to 15 ft. About 1 mi downstream from the site, the water depth increases rapidly, reaching a maximum depth of over 100 ft near Conowingo Dam.

A line of borings drilled in the river extending out from the plant site encountered an average sediment thickness of about 10 ft. The sediments consist primarily of fine sand and silt with occasional clayey zones. Sediment deposition in the pond for the first 20 yr after construction of Conowingo Dam amounted to about 7 ft.

CHAPTER 02 2.5-12 REV. 21, APRIL 2007

PBAPS UFSAR Bedrock underlying the river sediments near the site consists of the same Peters Creek schist encountered in the plant area. The schist is erratically weathered along planes of foliation in a manner similar to that observed in the rock exposed at the site.

2.5.2.3.6 Conclusions The site is underlain at shallow depths by competent Peters Creek schist, a metamorphosed sedimentary rock of Precambrian or early Paleozoic age. The rock provides excellent foundation support for the facility. The site is located in the structurally complex Piedmont Province. The nearest fault to the site is associated with the Peach Bottom Syncline and passes about 1 mi south of the site.

This fault and other regional faults have been inactive for 140 to 200 million yr.

Detailed analysis of the geology of the site and surrounding areas has revealed no geologic condition which would preclude construction and operation of a nuclear power station at this location.

2.5.3 Seismology 2.5.3.1 Introduction This subsection of the report presents the results of the engineering seismology studies performed by Dames and Moore.

2.5.3.1.1 Summary The site lies in a region which has experienced a moderate amount of minor earthquake activity. Most of the reported earthquakes have occurred in the Piedmont Province in which the site is located. Some minor shocks have occurred in a northeast-southwest trend along the Fall Zone, the physiographic boundary between the Piedmont and the Coastal Plain to the southeast. Some scattered activity has occurred in the Coastal Plain.

Based on the seismic history and the geologic structure of the region, no significant earthquake ground motion is expected at the site during the life of the facility. Despite demonstrative evidence to the contrary, consideration was given to the remote possibility that geologic structure in the epicentral areas of the significant regional earthquakes could exist in the site area.

CHAPTER 02 2.5-13 REV. 21, APRIL 2007

PBAPS UFSAR Thus, it has been hypothesized that a maximum credible earthquake (MCE) equivalent to the 1871 Wilmington, Delaware earthquake (maximum Intensity VII*) occurs near the site resulting in a maximum horizontal ground acceleration at foundation level of 12 percent of gravity. Such an event is highly improbable and this hypothesis is conservative.

Class I facilities have been designed to remain operable for horizontal earthquake ground accelerations equal to 5 percent of gravity (design earthquake).

2.5.3.2 Program of Investigation To develop a seismic design criteria for the plant, a comprehensive program of investigation was performed. The investigation included:

1. A comprehensive study of the geologic structure and tectonic history of the region.

2. A review of the seismic history of the region primarily based on a literature search.

3. Evaluation of the seismicity of the region considering the relationship of historic earthquakes to known geologic features, tectonics, and earthquake mechanisms.

4. Field geophysical measurements to evaluate pertinent physical properties of the bedrock at the site.

5. Selection of appropriate design earthquakes and MCE's.

6. An estimate of the maximum level of ground motion to be expected at the site due to the occurrence of the design earthquakes and MCE's.

7. Presentation of the seismic design criteria in the form of response spectra.

• All intensity values in this report refer to the Modified Mercalli Intensity scale of 1931, revised. The intensity scale is a means of reporting the size of an earthquake in terms of its perceptible effect.

Class I structures are founded on competent Peters Creek schist. Class I facilities have been designed to permit safe shutdown in the event of an MCE.

CHAPTER 02 2.5-14 REV. 21, APRIL 2007

PBAPS UFSAR 2.5.3.3 Geologic and Tectonic Background 2.5.3.3.1 Regional Geology The site is located in the Piedmont Uplands Section of the Piedmont Physiographic Province. The uplands is a northeast-southwest trending belt of structurally complex schist, gneisses, slates, and conglomerates with some igneous intrusions. The uplands is bounded by the Triassic Lowland and Conestoga Valley Sections to the northwest and the Coastal Plain Province to the southeast.

The rocks of the Piedmont uplands are of Precambrian and Paleozoic age and are known collectively as the Glenarm Series. They are metamorphosed sedimentary rocks and include, in order of decreasing age, Wissahickon and Peters Creek schists, Cardiff conglomerate, and Peach Bottom slate.

The Piedmont rocks are highly folded and often faulted. Folding and faulting have been mapped in the northern part of the Pennsylvania Piedmont where the complex structural conditions are exposed. Toward the southern part of the Piedmont, structural relationships are not as well exposed because of the much higher degree of metamorphism. However, the structural trends can be traced from the north and northeast into the general vicinity of the site and southward.

The dominant structural feature of the region is the Regional Appalachian Orogenic Belt. This belt is marked by the northeast-southwest orientation of the axes and lineation of most of the structural features and stratigraphic contacts.

Two major fault systems prevalent in the region are faults of Paleozoic age or older, and faults of Triassic age. The Paleozoic faults are largely thrust faults and occurred during early Paleozoic regional metamorphism or during the later Paleozoic Appalachian Orogeny. The thrust sheets are relatively thin and generally exhibit movement to the northwest. The north-south trending faults at their flanks are tears. These faults do not involve younger Mesozoic or Cenozoic strata and are completely healed.

In the Piedmont uplands, some of the major thrust faults are transected by Triassic age diabase dikes which show no displacement. Similar relationships of Triassic dikes crossing Paleozoic faults are found in the Reading Prong area north of the site. The last movement along these faults probably occurred 200 CHAPTER 02 2.5-15 REV. 21, APRIL 2007

PBAPS UFSAR million yr ago and certainly no later than 140 million yr ago, based on the absence of displacement of the Triassic diabase dikes. The Triassic faults are normal or strike slip faults that occurred during late Triassic or early Jurassic times. Most of these faults are located in and near the Triassic lowlands, about 30 mi from the site, and are of limited significance.

2.5.3.3.2 Site Geology The site is mantled by residual soils derived by weathering of the underlying schist. These soils are compact and consist of sandy silt and silty sand with gravel. The residual soils range in thickness from 0 to about 40 ft and are underlain by the Peters Creek formation.

At the site, the Peters Creek is a greenish-gray to white chlorite schist interbedded with seams and bands of quartzite that range up to 6 ft in thickness. The upper part of the Peters Creek formation has been altered by weathering. The zones of severe weathering are generally limited to thicknesses of 25 ft or less, although excavation in the western portion of the construction area encountered highly weathered rock to depths in excess of 65 ft below the original rock surface. A few seams within the bedrock exhibit a high degree of weathering to known depths of up to 200 ft. These weathered zones are relatively thin and generally parallel the schistosity of the rock.

Below the highly weathered zone, the rock is fresher and harder.

The relatively fresh, hard rock occurs at depths ranging from approximately 15 to 80 ft below the original ground surface. The greater depths of weathering were generally encountered in the higher, western portion of the construction area. Compressional wave velocities in the Peters Creek formation range from under 7,000 fps in the highly weathered zone to over 16,000 fps in the relatively fresh rock.

A zone of Paleozoic faults trending through the vicinity of the Peach Bottom site has been inferred. One of these faults is associated with the Peach Bottom Syncline, the closest structure to the site.

The Peach Bottom Syncline is a narrow, tightly folded syncline which trends in a northeast-southwest direction. Its axis, and that of its associated fault, are located approximately 1 mi south of the site.

CHAPTER 02 2.5-16 REV. 21, APRIL 2007

PBAPS UFSAR Other faults with traces roughly parallel to that of the Peach Bottom fault have been mapped to the northwest and southeast of the site. The closest of these mapped faults lies approximately 4 mi from the site.

Studies indicate that the Peach Bottom fault, and the similar nearby faults, have been completely healed.

The most recent fault movement in the region is believed to have occurred during Mesozoic time between 140 and 200 million yr ago.

Earlier activity has been traced to the Devonian Period with possible movement as early as late Ordovician times, some 440 to 460 million yr ago.

2.5.3.4 Seismicity 2.5.3.4.1 General The site is located in an area which has experienced a moderate amount of minor earthquake activity. The record of earthquake occurrence in southeastern Pennsylvania and the surrounding areas date back to the early 18th Century. Many earthquakes have been reported since that time and some of these caused minor structural damage; however, none can be considered to be of great or catastrophic proportion. Since this region has had a relatively large and well-distributed population since the early 18th Century, it is probable that any major earthquake activity (Intensity VIII or larger) since that time would have been reported in local newspapers, private journals, or diaries. The absence of such documentation is indicative of the absence of major earthquake activity in the region during this period.

2.5.3.4.2 Regional Relationship of Tectonics to Earthquakes Most of the earthquake activity in southeastern Pennsylvania and the surrounding area occurs in the Piedmont, west of the Fall Zone. The trend of epicenters in the region is generally northeast-southwest, parallel to the trend of geologic structure in the Piedmont. Most of the areas of activity can be related to known faulting or other geologic features.

There also appears to be a pattern of minor seismicity trending in a northeast-southwest direction, in a narrow belt roughly along the axis of the Fall Zone.

To the southeast of the Fall Zone, there is scattered earthquake activity within the Coastal Plain. Since little is known of the CHAPTER 02 2.5-17 REV. 21, APRIL 2007

PBAPS UFSAR tectonics of the basement rock in the Coastal Plain, it is not possible to relate these reported earthquakes to documented tectonic features. It is believed that the bedrock in the Coastal Plain is similar to that exposed in the Piedmont, and thus the more significant earthquake activity would probably be related to structures in the bedrock. However, there is no major active faulting in the region.

2.5.3.4.3 Regional Seismicity The zone of major earthquake activity closest to the site is the St. Lawrence River Valley Region, whose closest approach is about 350 mi to the northwest. The St. Lawrence River Valley is a major rift valley formed of a downfaulted graben structure. The tectonic development of the St. Lawrence River Valley is completely dissimilar to the tectonic development of the Piedmont.

The major earthquakes of the St. Lawrence River Valley (shocks in 1663 and 1925 with maximum intensities as great as IX or X) had their epicenters near Quebec, over 550 mi northeast of the site.

These earthquakes were felt over the entire eastern section of Canada and the United States and probably had an intensity of about IV in the site area.

Earthquakes near Charleston, South Carolina, in 1886 are the only major earthquakes recorded in the Coastal Plain of the eastern United States. These shocks, which had a maximum intensity of about IX, had their epicenters about 550 mi southeast of the site.

It is probable that these shocks were felt in the site area with an intensity of about III. It is believed that these earthquakes are related to local faulting in the basement rock near Charleston.

Although no major earthquakes have had epicenters closer than about 350 mi to the site, many earthquakes of low to moderate intensity have originated in the region surrounding the site. Most shocks in the region have occurred in a narrow zone within the Piedmont Province, parallel to the Fall Zone. No other trend of epicenters appears to exist in the region.

The largest earthquakes reported in the area had epicentral intensities of VII. Of the two Intensity VII shocks recorded, the closer occurred in October, 1871 near Wilmington, Delaware about 40 mi east of the site, causing some minor damage near its epicenter. The other Intensity VII shock was recorded about 100 mi from the site near Wilkes-Barre, Pennsylvania in February, 1954.

CHAPTER 02 2.5-18 REV. 21, APRIL 2007

PBAPS UFSAR In addition to the above-described shocks, seven earthquakes with epicentral intensities of VI have occurred in this area.

The epicentral locations of all known earthquakes of Intensity V or greater originating in the region surrounding the site are shown in Figure 2.5.1. A list of earthquakes of Intensity V or greater which have occurred within about 100 mi of Peach Bottom is presented in Table 2.5.3.

2.5.3.4.4 Local Seismicity Five significant earthquakes have been recorded within a radius of 50 mi of the site. One was of Intensity VII; two shocks had epicentral intensities of VI; and two were recorded with maximum intensities of V.

The earthquakes closest to the site occurred in southeast Pennsylvania on March 8, 1889 about 25 mi northeast of the site (Intensity V), and in Harford County, Maryland in March, 1883 some 20 mi southwest of the site (Intensity IV-V). The 1889 earthquake was felt in an area of about 4,000 sq mi but did no significant damage. The series of 1883 Harford County earthquakes were local shocks causing no structural damage.

Three other shocks originated about 35 to 40 mi from the site. The largest of these originated near Wilmington, Delaware on October 5, 1871 and probably was felt in the vicinity of the site. The magnitude of this shock is estimated at about 5 or slightly higher on the Richter Scale.

Although several of the aforementioned shocks probably were felt in the locality of the site, no damaging effects were experienced.

The ground motion at the site expected from a shock similar to any of the historical shocks would not cause damage to reasonably well-built structures.

On an historical basis, it would appear that the site may experience earthquake motion during the life of the plant facilities, but no damage would be expected in even moderately well-designed structures.

2.5.3.5 Site Seismic Evaluation 2.5.3.5.1 Selection of Maximum Credible Earthquake CHAPTER 02 2.5-19 REV. 21, APRIL 2007

PBAPS UFSAR On the basis of the seismic history of the area, it does not appear likely that the site would be subjected to significant earthquake ground motion during the life of the facility. However, in order to establish criteria for the MCE, the degree of ground motion which is remotely possible, considering both the seismic history and geologic structure of the region and site area, was examined. The MCE has been considered to be the largest shock in the region at the closest epicentral distance to the site consistent with geologic structure.

The largest recorded earthquake in the region surrounding the site was the 1871 Wilmington, Delaware Intensity VII shock. Although it is likely that the 1871 Wilmington shock was related to readjustment along the Fall Zone, it may be related to a faulted area several miles north of Wilmington. It is possible that this faulted area may be related to the series of faults inferred to pass through the vicinity of the site.

Although the possibility is considered remote, the effect of a shock as large as the 1871 Wilmington (Magnitude 5 to 5 1/2) earthquake occurring as close to the site as the Peach Bottom Fault was investigated. It is estimated that this maximum credible shock could produce ground accelerations at the plant site as high as 12 percent of gravity. The Class I facilities are designed in accordance with this MCE criterion of 12 percent of gravity.

2.5.3.5.2 Selection of Design Earthquake On the basis of the seismic history of the area, the Class I facilities are designed to withstand ground accelerations which could result from a shock of about the same size as the earthquakes of 1871 (Wilmington), 1883 (Harford County), or 1889 (southeast Pennsylvania) at the closest approach to the site of their related geologic structure.

It has been estimated that the magnitude of the 1871 Wilmington shock was about 5 or slightly larger. The maximum ground acceleration at the site due to a recurrence of this shock at an epicentral distance of 20 mi (the closest approach of the Fall Zone to the site) would be less than 5 percent of gravity.

The magnitudes of the 1883 Harford County shocks and the 1889 southeast Pennsylvania shock were estimated to be less than 4. It has been estimated that ground motion at the site due to a Magnitude 4 earthquake about 17 mi from the site would be insignificant.

CHAPTER 02 2.5-20 REV. 21, APRIL 2007

PBAPS UFSAR Based upon this study of the earthquake activity in the vicinity of the site and considering the nature of the proposed facilities, the major structures were designed to accept ground accelerations of 5 percent of gravity for the design earthquake condition.

2.5.3.6 Seismic Design Criteria 2.5.3.6.1 Response Spectra The seismic Class I structures were designed in accordance with the response spectra illustrated in Figures C.3.1 and C.3.2, Appendix C, "Structural Design Criteria."

CHAPTER 02 2.5-21 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.5.1 ROCK TENSILE TEST DATA Depth Tensile Strength Boring (ft) (psi)

H-1 147 418 H-13 182.5 362 H-13 183 966 H-13 183.5 573 H-31A 40 110 H-65 91 528 H-65 92.5 343 CHAPTER 02 2.5-22 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.5.2 SHOCKSCOPE TEST RESULTS Velocity of Compressional Average Confining Wave Dynamic Modulus Depth Pressure Propagation Elasticity Boring (ft) Material (psf) (fps) (psi)

H-1 130 Peters 0 15,580 10.2 x 106 Creek 2,000 17,980 Schist 4,000 17,980 6,000 18,690 H-32 19 Peters 0 8,330 1.8 x 106 Creek 2,000 8,740 Schist 4,000 8,740 6,000 8,740 H-32 29 Peters 0 13,160 6.9 x 106 Creek 2,000 14,340 Schist 4,000 14,340 6,000 15,770 H-32 79 Peters 0 16,390 10.4 x 106 Creek 2,000 18,210 Schist 4,000 18,210 6,000 18,210 H-35 16 Peters 0 5,460 0.8 x 106 Creek 2,000 5,690 Schist 4,000 5,690 6,000 5,940 H-35 20 Peters 0 10,570 5.1 x 106 Creek 2,000 12,920 Schist 4,000 12,920 6,000 12,920 H-35 39 Peters 0 15,670 9.3 x 106 Creek 2,000 17,240 Schist 4,000 17,240 6,000 17,240 H-35 65 Peters 0 14,220 8.1 x 106 Creek 2,000 15,500 Schist 4,000 15,500 6,000 17,060 H-47 35 Peters 0 7,850 2.1 x 106 Creek 2,000 9,160 Schist 4,000 9,160 6,000 10,990 H-47 43 Peters 0 12,750 6.9 x 106 Creek 2,000 14,880 Schist 4,000 14,880 6,000 14,880 CHAPTER 02 2.5-23 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.5.3 SIGNIFICANT EARTHQUAKES WITHIN ABOUT 100 MILES OF PEACH BOTTOM, PENNSYLVANIA (Intensity V or Greater)

EPICENTRAL LOCATION Intensity Distance Perceptible (Modified) From Site Area Year Date Time* Mercalli) Locality N.Lat. W.Long. (mi) (sq mi) 1871 Oct 9 09:40 VII Wilmington, Delaware 39.7 75.5 45 --

1877 Sept 10 09:59 IV-V Delaware Valley 40.3 74.9 85 300 1879 Mar 25 19:30 IV-V Delaware River 39.2 75.5 55 600 1883 Mar 11 18:57 IV-V Harford County, Maryland 39.5 76.4 20 Local Mar 12 00:00 IV-V Harford Conty, Maryland 39.5 76.4 20 Local 01:00 1884 May 31 -- V Allentown, Pennsylvania 40.6 75.5 75 Local 1885 Jan 2 21:16 V Maryland and Virginia 39.2 77.5 75 3,500 1889 Mar 8 18:40 V Southeast Pennsylvania 40 76 25 4,000 1895 Sept 1 06:09 VI New Jersey 40.7 74.8 105 35,000 1906 May 8 12:41 V Delaware 38.7 75.7 80 400 1908 May 31 12:42 VI Allentown, Pennsylvania 40.6 75.5 75 Local 1909 April 2 02:25 V-VI Virginia, West Virginia, 39.4 78.0 95 2,500 Maryland and Pennsylvania 1921 Jan 26 18:40 V New Jersey 40 75 70 150 1933 Jan 24 21:00 V Near Trenton, New Jersey 40.2 74.7 90 600 1938 July 15 17:45 VI Southern Blair County, Pa. 40.4 78.2 110 100 Aug 22 22:36 V Central New Jersey 40.1 74.5 95 5,000 1939 Nov 14 21:54 V Salem County, New Jersey 39.6 75.2 60 6,000 1954 Jan 7 02:25 VI Sinking Spring, Pennsylvania 40.3 76.0 40 --

Feb 21 15:00 VII Wilkes-Barre, Pennsylvania 41.2 75.9 100 Local Feb 23 22:55 VI Wilkes-Barre, Pennsylvania 41.2 75.9 100 Local 1957 Mar 23 14:03 VI West-Central New Jersey 40-3/4 75-3/4 105 --

1961 Sept 14 21:17 V Lehigh Valley, Pennsylvania 40-3/4 75-1/2 80 Local Dec 27 12:06 V Pennsylvania-New Jersey Border 40-1/2 74-3/4 85 --

1964 May 12 01:45 VI Near Cornwall, Pennsylvania 40.2 76.5 33 --

• Using 24-hour clock CHAPTER 02 2.5-24 REV. 21, APRIL 2007

PBAPS UFSAR 2.6 ENVIRONMENTAL RADIATION MONITORING PROGRAM 2.6.1 General In conjunction with Unit 1, the HTGR located at the PBAPS, a pre-operational environmental radiation survey was conducted between March, 1960 and February, 1966 at which time this reactor first achieved criticality. Nuclear Science and Engineering Corporation, who began monitoring in March, 1960, and Combustion Engineering, Inc., who began monitoring in July, 1962, were employed as the consultants to the licensee for collecting and analyzing various samples. The objective of the program was to acquire quantitative data for the concentrations of radioactivity in environmental media in the vicinity of the reactor site prior to the operation of the HTGR.

An environmental radiation monitoring program similar in scope to that carried out prior to February, 1966 has continued since that time in order to acquire similar data after the initial operation of Unit 1. The program was expanded with the advent of Units 2 and 3 in order to continue monitoring environmental radioactivity levels in the Peach Bottom area.

The Environmental Radiation Monitoring Program as presented in the original FSAR (Section 2.6.2) is historical. The facility's Technical Specifications define the current Radiological Environmental Monitoring Program (REMP). The Offsite Dose Calculation Manual (ODCM) expands upon the REMP as defined by the facility's Technical Specifications and contains up-to-date information on the program. Monitoring is performed at onsite and offsite locations as described in the ODCM. The results of the REMP are reported in the Annual Radiological Environmental Operation Report. This report also includes the results of the annual land census.

2.6.2 Pre-operational Radiation Monitoring Program Description Twelve environmental sampling stations (1 through 12), whose locations are shown in Figures 2.6.1 and 2.6.2, have been utilized in both the Unit 1 pre-operational and post-operational environmental survey through 1973. This program was also used as part of the pre-operational radiation monitoring program for Units 2 and 3.

Two of the environmental monitoring stations now have more than one instrument of a type. At the site, Station 1, one gamma CHAPTER 02 2.6-1 REV. 26, APRIL 2017

PBAPS UFSAR scintillation detector and one rain gauge collector are located near the base of Weather Tower No. 1, designated Station 1A, and another instrument of each type, installed in October, 1967 and August, 1967, respectively, is located near the base of the microwave tower, designated Station 1B. These towers are shown in Figure 2.3.1. In addition, two air particulate samplers are located side by side at the bases of Weather Tower No. 1, and a third, 1B, is located at the base of the Microwave Tower. Of these, the original sampler, 1A, has been operated by Nuclear Science & Engineering Corporation, International Chemical and Nuclear Corporation (who acquired Nuclear Science and Engineering Corporation in 1967), Interex Corporation, and Chem Waste Management, Inc. (who acquired Interex Corporation in 1981). The second sampler, 1Z, placed in service in July 1962, has been operated by Combustion Engineering and Radiation Management Corporation. The 1B sampler has been operated by International Chemical and Nuclear Corporation, Interex Corporation, and Chem Waste Management, Inc., since it was placed in service in November 1967. Two air particulate samplers are now located side by side on top of the power house at Conowingo Dam, Station 4; the second station, 4B, began operation in May 1962.

The pre-operational environmental program for Units 2 and 3 was carried out through August 8, 1973 by Combustion Engineering, Inc., Nuclear Science and Engineering Corporation, followed by International Chemical and Nuclear Corporation (with work performed by ICN/Tracerlab, Chemical and Radioisotope Division since early 1969). Since mid-1972 Interex Corporation and Radiation Management Corporation continued the program. This is documented in references 1, 2, and 3. These reports have been previously submitted to the NRC and are made part of the PBAPS Updated FSAR by reference.

This environmental program is designed to monitor various types of pertinent materials in the food chains of both animals and humans.

Samples are taken of the atmospheric, terrestrial, and aquatic environment, using those media which are sensitive indicators of changes in the environmental radioactivity such as particulate matter in air, water, soil, and sediment as well as those which could enter the human food chain such as potable water, milk, vegetation, and fish. The program also monitors the general levels of radioactivity in the environment in a number of substances in which radioactivity would likely be found if it were present. Each type of sample is analyzed for the type or types of gross radioactivity or the particular isotope(s) of biological significance most likely to be present in that type of sample.

CHAPTER 02 2.6-2 REV. 26, APRIL 2017

PBAPS UFSAR With the advent of Units 2 and 3, the Peach Bottom radiation monitoring program was reviewed and revised to include additional monitoring directed toward the gaseous and liquid discharges by the BWR units. These revisions did not affect the Combustion Engineering program.

As a part of the expanded monitoring program, the Radiation Management Corporation of Philadelphia was retained to monitor the tritium in environmental water samples and to monitor ambient gamma doses by use of thermoluminescent dosimeters (TLD) at a number of locations both on- and off-site as listed in the referenced reports. Additional analyses were added to the Radiation Management Corporation's portion of the program, including fish, vegetation, milk, and soil. Analyses included gamma spec, gross beta and alpha, K-40, I-131, and strontium.

Tritium measurements began September 24, 1970. The TLD measurements began May 25, 1971 at eight locations and expanded to 35 locations as they became available. The gamma dose monitoring station locations were chosen after a careful study of the Peach Bottom area meteorological, topographic, and demographic data.

The licensee periodically reviews its Peach Bottom environmental radiation monitoring program and continues to cooperate with appropriate governmental agencies by providing them with periodic reports on the program results.

2.6.3 Pre-operational Radiation Monitoring Program Results Results of the Pre-operational Peach Bottom Environmental Program are summarized in the referenced reports. Maximum and minimum values are reported for the entire Pre-operational Period through August 1973, and mean values are reported for each year for each type of sample analysis performed. The types and levels of activity detected in these samples indicated the presence of only naturally occurring radionuclides and those which have resulted from the testing of nuclear weapons.

The general levels of radioactivity at the site and in the surrounding regions were found to be generally low at the beginning of the survey period, but rose rapidly in 1961 due to weapons testing, and continued at a relatively high level through 1962 and into 1963. From late 1963 through 1967, dispersions and decay generally reduced activity levels to the 1960 levels.

Radioactivity levels again rose in 1968 through 1971 due to additional weapons testing throughout the world, then decreased again in 1972 and 1973.

CHAPTER 02 2.6-3 REV. 26, APRIL 2017

PBAPS UFSAR These trends can best be seen in the levels of radioactivity in particulate matter in the atmosphere. Annual maximum, annual minimum, annual mean, and monthly mean values of filterable air particulate radioactivity measured at the site area and Philadelphia stations are presented in the reference section of the Interex Corporation Report. Comparisons are made with similar values at Harrisburg, Pennsylvania and Trenton, New Jersey, reported by the U.S. Public Health Service in their series of "Radiological Health and Data Reports." It can be seen that the levels of radioactivity vs. time are similar in all four widely separated regions, indicating that the general levels of air particulate radioactivity are the same throughout this section of the United States.

Correlation with Public Health Service data since mid-1967 is not as good as in earlier years because the Public Health Service data changed from a sensitive laboratory analysis to a less sensitive field measurement at that time and because the Public Health Service data has been rounded off to the nearest pci/cu m beginning in early 1968.

2.6.4 Additional Cooperative Monitoring Programs In conjunction with the Peach Bottom environmental radiation monitoring program, the licensee began participating in 1960 in what was formerly known as the National Water Quality Network Program begun by the U.S. Public Health Service of the Department of Health, Education, and Welfare and now continued under the Water Quality Office of the Environmental Protection Agency.

Participation in this program consists of using the Conowingo Hydroelectric Power Plant as a sampling station in the network. A duplicate sample of surface water from Holtwood Dam is also provided to the network. Cooperation in this program is being continued to assist in establishing the background environmental radiation levels both upstream and downstream of the Peach Bottom plant.

The AEC contracted with the Commonwealth of Pennsylvania, Office of Radiological Health to perform a 3-yr radiological monitoring program at Peach Bottom and two other nuclear plants in Pennsylvania. The program began in 1971 and was aimed at monitoring onsite radwaste handling and the concentrations of radioactivity in the environment surrounding the stations. The NRC continued this program through 1981. The licensee is cooperating with the Commonwealth by providing them access to the company facilities and by providing radiation monitoring samples taken under the surveillance of Commonwealth personnel.

CHAPTER 02 2.6-4 REV. 26, APRIL 2017

PBAPS UFSAR Each year since 1960 the licensee has filed two reports with the NRC which outline the tests conducted and results obtained. The most recent reports are as follows:

1. Radiological Regional Environmental Monitoring Program for Peach Bottom Atomic Power Station, Report No. 17, January 1, 1981 through December 31, 1981, Radiation Management Corporation, May 1982.

2. Environs Radiation Monitoring Program for Peach Bottom Atomic Power Station, Report No. 39, January 1, 1981 through December 31, 1981, Chemical Waste Management Inc., May 1982.

Other reports for previous years are on file with the NRC.

The environmental radiation monitoring program is adjusted year to year to sample and define any new concerns that may develop. The reports submitted each year outline the program and sampling points for that year.

CHAPTER 02 2.6-5 REV. 26, APRIL 2017

PBAPS UFSAR 2.6 ENVIRONMENTAL RADIATION MONITORING PROGRAM REFERENCES

1. Pre-operational Radiological Environmental Monitoring Report for Units 2 and 3, Peach Bottom Atomic Power Station, September 1970 to August 1973, Radiation Management Corporation, dated January 1974.

2. Environs Radiation Monitoring Program Pre-operational Summary Report for Units 2 and 3, Peach Bottom Atomic Power Station, February 5, 1966 through August 8, 1973, Interex Corporation, dated June 1977.

3. Radiation Monitoring Program for Peach Bottom Atomic Power Station, Operational Reports Nos. 15-32, January to June 1966 (No. 15) through January to December 1974 (No. 32),

Combustion Engineering, Inc.

CHAPTER 02 2.6-6 REV. 26, APRIL 2017

PBAPS UFSAR 2.7 FOUNDATION ANALYSIS 2.7.1 General The foundation analysis for the construction of Units 2 and 3 was performed in three parts:

1. Field explorations.

2. Laboratory tests.

3. Establishment of foundation design criteria.

2.7.2 Field Explorations Along with, and in addition to, the geologic and seismic explorations, detailed foundation investigations including borings were carried out for use in the design of the foundations for the structures.

2.7.2.1 Test Borings Prior to the construction of Unit 1, 38 borings were drilled in the general plant area. The results of this previous work were considered in the foundation analysis for Units 2 and 3.

Subsurface conditions were further explored by drilling 115 additional test borings. The majority of the test borings were located in the vicinity of Units 2 and 3. The locations of these test borings and test pits are shown on the Boring Plan, Figure 2.7.1. A number of borings were located within Conowingo Pond in the vicinity of the discharge canal and cooling towers.

Most of the borings in the higher portions of the site extended into the bedrock and were drilled to depths on the order of 100 to 200 ft below the ground surface. The borings drilled in the lower area near Conowingo Pond generally penetrated to depths ranging from 20 to 60 ft below the ground surface. The borings drilled within the Conowingo Pond usually were terminated at the rock surface, although rock was cored in a number of these borings.

Disturbed and undisturbed soil samples, suitable for laboratory testing, were extracted from the test borings, examined, and subjected to appropriate laboratory tests.

All rock cores extracted from the test borings were examined with regard to type of rock, strike and dip, fractures, seams, joints, CHAPTER 02 2.7-1 REV. 25, APRIL 2015

PBAPS UFSAR and other pertinent physical characteristics. Selected core samples were subjected to appropriate laboratory tests.

Figures 2.7.2 through 2.7.9 show some of the Boring Logs which are representative of the borings taken and describe the soils and bedrock encountered at the plant site.

2.7.2.2 Field Permeability Tests A series of pump-in, pump-out, and percolation tests were performed to obtain estimates of the permeability of the in situ materials at predetermined depths. The data obtained from these tests were used to establish dewatering requirements during excavating for the foundations.

2.7.3 Laboratory Tests Representative undisturbed soil samples and rock cores extracted from the test borings were subjected to a comprehensive laboratory testing program to evaluate the physical and chemical characteristics of the soils and rock encountered at the site.

The laboratory program included the following tests:

1. Static Tests

a. Direct shear

b. Unconfined compression

c. Triaxial compression

d. Rock tensile

e. Brazilian rock tensile

f. Confined compression (consolidation)

2. Dynamic Tests

a. Triaxial compression

b. Shockscope

3. Other Physical Tests

a. Moisture and density CHAPTER 02 2.7-2 REV. 25, APRIL 2015

PBAPS UFSAR

b. Particle-size

c. Atterberg limits

d. Compaction

4. Chemical Tests

a. pH values

b. Soluble sulphates

c. Ground water analyses 2.7.4 Subsurface Conditions The results of the field exploration program indicate that the plant area is underlain by three basically different, but related, materials. These are, in order of increasing depth:

1. Surficial sandy silt and silty sand with gravel (residual decomposed rock).

2. Highly weathered rock.

3. Relatively fresh rock.

The southeast corner of the construction area is covered by up to 20 ft of silt, sand, and gravel fill containing construction debris. Underlying the fill in this area, and at the surface in the remaining site area, is compact silty sand and sandy silt containing gravel. This soil is the product of decomposition of the bedrock. The residual soil ranges from 0 thickness at locations where the underlying rock crops out to about 40 ft.

Underlying the residual soil is highly weathered Peters Creek schist. This formation is a greenish-gray to white metamorphic rock consisting of chlorite schist interbedded with thin bands of quartzite. The schistosity and cleavage planes dip to the southeast at about 60 to 70 deg. The highly weathered zone ranges in thickness from less than 10 to greater than 60 ft. The rock generally grades less weathered with depth, although thin seams of weathered rock were observed at depths in excess of 200 ft below the ground surface.

The surface of the relatively fresh rock was encountered in the plant area at elevations ranging from about 100 to 200 ft. (All CHAPTER 02 2.7-3 REV. 25, APRIL 2015

PBAPS UFSAR elevations are referred to Conowingo Datum.) This surface generally follows the topography, sloping downward toward the Susquehanna River. Contours of the surface of the relatively fresh rock are shown in Figure 2.7.1. The contours are based on the results of the subsurface investigations and were prepared by interpolating between borings.

2.7.5 General Foundation Criteria 2.7.5.1 General The results of this investigation indicated that the compact residual soil, the weathered rock, and the relatively fresh rock are all suitable for foundations for the plant facilities.

Although anticipated movements would be very small, individual structures are founded on a single type of foundation material (i.e., either soil or rock, but not both) in order to minimize differential foundation movement.

Spread or mat foundations are used for support of all facilities in the plant area. Pile foundations are required for support of certain structures installed in and near Conowingo Pond.

To obtain greater bearing capacity and less foundation movement, foundations are founded in the relatively fresh rock rather than the overlying weathered rock.

The base of each of the major structures is founded below the surface of the relatively fresh rock. Other less critical facilities are founded above the fresh rock surface on either the highly weathered rock, the compact residual soils, or compacted structural fill.

2.7.5.2 Spread or Mat Foundations Based upon the results of the laboratory tests and engineering analyses, the following general criteria were used in developing foundation designs:

1. Spread or mat foundations installed at shallow depths within controlled compacted fill can be designed utilizing bearing pressures of up to 1 1/2 tons per sq ft, depending on the depth and least width of the foundation, settlement restrictions, and quality of the fill.

2. Spread or mat foundations established within the compact residual soils at a depth of at least 4 ft below lowest CHAPTER 02 2.7-4 REV. 25, APRIL 2015

PBAPS UFSAR adjacent grade can be proportioned using bearing pressures of up to 3 tons per sq ft.

3. Spread or mat foundations installed in the weathered rock can be designed utilizing bearing pressures of up to 5 tons per sq ft.

4. Spread or mat foundations established on relatively fresh rock (or lean concrete fill placed over fresh rock) can be designed utilizing bearing pressures of up to 20 tons per sq ft.

The recommended bearing pressures apply to the total of all design loads, dead and live, and refer to the pressure which can be imposed in excess of the pressure imposed by the adjacent overburden. Specific foundation design for each of the structures is discussed in subsequent paragraphs.

2.7.5.3 Pile Foundations Little or no compact residual soil was encountered in the test borings in and near the Susquehanna River. Consequently, the structures located in this area are supported on pile foundations.

Steel H bearing pile foundations support certain auxiliary structures. The piles are driven to refusal and derive their support from the Peters Creek formation. The pile foundations are designed for a maximum load of 60 tons per pile.

The piles support only gravity loads. No credit was taken for the influence of the piles on the lateral dynamic characteristics of the structure or equipment response.

All piles, including those for Class I structures, are of materials for which physical and chemical tests verified their compliance with the material specifications. Pile driving was done under Quality Control by Bechtel field forces. Pile driving records, material, identification, and inspection reports were maintained. All piles are protected by the plant cathodic protection system.

CHAPTER 02 2.7-5 REV. 25, APRIL 2015

PBAPS UFSAR 2.7.6 Foundations for Structures 2.7.6.1 General The results of foundation studies based on the field explorations and laboratory tests are presented, and the specific criteria for the foundation design for various structures are established.

2.7.6.2 Design Considerations The plant facilities include four major structures: the reactor buildings, the radwaste building, and the turbine building.

Auxiliary structures include the diesel-generator building, the stack, the administration building, the emergency cooling tower, shop, and warehouse, the water treatment building, and the boiler house. Marine structures are located in the area of Conowingo Pond. These structures include the pump structure (for service and circulating water intake), the cooling towers, the offshore embankments, and additional structures such as the intake screen structure, the cooling tower pump structure, the discharge control structure, the bridge structure, and the on-site storage radwaste facility.

A detailed description of foundations provided for the structures is given in the following paragraphs.

Figure 2.7.1 shows the locations of the major plant structures in relation to the test borings drilled in the plant area.

2.7.6.3 Major Structures The reactor buildings are constructed in the western portion of the construction area, as shown in Figure 2.7.1. The lowest floor of these structures is founded at Elevation 87.0 ft. In order to reach this elevation, excavation ranging from about 80 to 160 ft was required. The drywells are installed on rock pedestals, at Elevation 104.0 ft, in the central portion of the buildings. The pedestals are 65 ft in diameter.

The base of these structures is 50 to 100 ft below the surface of the relatively fresh rock. Consequently, it was anticipated that the rock at the foundation depth would be sound. However, since the exploration program revealed that occasional thin, nearly vertical seams of weathered rock exist to great depths below the relatively fresh rock surface, the rock exposed at foundation level was carefully examined by an experienced engineering geologist to determine where it was necessary to remove the CHAPTER 02 2.7-6 REV. 25, APRIL 2015

PBAPS UFSAR weathered rock seams to some depth below foundation level. Any over-excavated material was replaced with lean concrete.

A slab of lean concrete, at least 3 in thick, protected the exposed surface against deterioration of the foundation rock. The concrete mat foundation for the structures rests on the lean concrete slab with a waterproofing membrane between them.

Shears are resisted by rock pedestals and passive pressures at ends of walls and miscellaneous keys formed by depressed slabs in the radwaste and turbine buildings. The governing load combination (D + L + E) results in a shear key value of 5,500 psf.

The maximum shear stress in the rock due to the imposed vertical load as well as the direct horizontal shears is small in comparison with the ultimate shear strength of the rock as indicated by laboratory tests performed by Dames & Moore. The shear strength of the rock, based on the test data, is approximately 72,000 psf (paragraph 2.9.8).

A Dames & Moore engineering geologist was in attendance at the site during foundation construction. He inspected the quality of the rock before, during, and after excavation, and ascertained that it was sound and free of defects.

The estimated total settlement that the containment buildings will experience consists of elastic deformations of less than 1/2 in under the design loads. Since these structures consist primarily of dead load, most of the elastic deformation occurs during construction. Post-construction movement is expected to be small, less than 1/4 in.

The radioactive waste handling building is constructed on rock between the two containment structures. The floor of this building is founded at Elevation 91.5 ft, about 70 to 90 ft below the surface of the relatively fresh rock.

The estimated elastic movements of the radwaste building are less than 1/4 in due to the design floor load.

The turbine-generator building is constructed east of the reactor buildings. The mat foundations beneath the turbine-generators are founded generally at Elevation 106 ft 6 in. A lightly loaded concrete floor slab covers the remaining area in turbine-generator building.

CHAPTER 02 2.7-7 REV. 25, APRIL 2015

PBAPS UFSAR The Unit 3 turbine mat is founded at depths ranging from 10 to 60 ft below the fresh rock surface. The Unit 2 turbine mat is founded below or near the surface of the fresh rock.

The estimated elastic deformation of the foundation rock is about 1/4 in or less beneath the turbine mats.

The circulating water discharge tunnel is constructed adjacent to and below the western edge of the turbine mats. During construction of the tunnel, blasting operations were controlled so that the foundation rock beneath the turbine mats in this area would not be adversely affected.

The foundations for the walls and columns of the turbine building are installed generally at about Elevation 90.0 ft in the relatively fresh rock.

2.7.6.4 Auxiliary Structures The foundation of all areas of the radwaste on-site storage facility with the exception of the DAW storage, staging and dock areas, are supported on mat foundations. The structural loads in the DAW storage, staging and dock areas are transmitted to spread footings located at least 4 feet below grade on either compacted fill or competent soil.

All other auxiliary buildings referred to in paragraph 2.7.6.2 are supported on pile foundations except the boiler house, the stack and the emergency cooling tower north of the reactor building, which is supported on spread footings on the fresh rock. Among these, the only seismic Class I structures are the diesel-generator building, the stack and the emergency cooling tower.

The pile foundations were necessary since these structures are located either in the reclaimed area of Conowingo Pond or in the backfilled areas where the rock was excavated during plant construction.

2.7.6.5 Marine Structures 2.7.6.5.1 Pump Structure The pump structure for service and circulating water intake is located within Conowingo Pond, and its face is 200 to 300 ft from the original shoreline. The location of this facility is shown in relation to the onshore facilities in Figure 2.7.1. The structure is nominally 80 ft by 250 ft in plan dimensions. The base of most of the structure is at Elevation 77.0 ft.

CHAPTER 02 2.7-8 REV. 25, APRIL 2015

PBAPS UFSAR The borings drilled in the vicinity of this structure indicate that relatively fresh rock ranges from Elevation 78 to 82 ft. The base of most of the structure (at Elevation 77.0 ft) is installed within the relatively fresh rock.

2.7.6.5.2 Cooling Towers Cooling towers are located south-southeast of the intake structure within the pond area.

Borings drilled in this area encountered from 6 to 12 ft of soft clay and silty soils overlying the bedrock. The cooling towers are installed on rock fill embankment.

Satisfactory support for the cooling towers, which are founded at Elevation 111.0 ft, was achieved by proper control over the fill placement and by the utilization of a surcharge program. This method avoided excessive settlement of the cooling towers due to the underlying strata of soft clay and silty soils.

2.7.6.5.3 Offshore Embankments The embankments extend about 1 mi downstream and about 1,200 ft upstream from the circulating water pump structure. Final grade at the surface of the embankment is approximately Elevation 116.0 ft.

Borings drilled near the embankments indicate that subsurface conditions are similar to those encountered in the area of the cooling towers. Approximately 25 to 30 ft of fill was required to construct the embankments. The required fill was obtained from excavations in the inland construction area and consist of both soil and rock fragments.

The embankments were constructed in the same manner previously described for fill placement for support of the cooling towers, and have side slopes of one vertical to one and one-half horizontal. However, no surcharge was required for these embankments.

2.7.6.5.4 Additional Structures The intake screen structure, cooling tower pump structure, discharge control structure, and bridge structure are also located within the pond area and are supported on rock.

CHAPTER 02 2.7-9 REV. 25, APRIL 2015

PBAPS UFSAR 2.8 SITE PREPARATION 2.8.1 General Preparation of the Peach Bottom site for Units 2 and 3 consisted primarily of excavating over 1,500,000 cu yd of soil and rock and of cutting the major slopes in portions of the site. The construction of the major slopes, blasting techniques, dewatering, and backfilling, is discussed in the following paragraphs.

2.8.2 Major Slopes 2.8.2.1 General One of the most important aspects of the site preparation was the cutting of stable slopes on the west and north sides of the site. Because of the significant height and close proximity of these slopes to the structures, as shown on the Plot Plan, Drawing C-2, extensive stability studies were performed to evaluate the steepest angle at which the slopes could be safely cut. The studies consisted of evaluating, both qualitatively and quantitatively, all apparent factors which could affect the stability of the slopes. Some of these factors are the strength of the material, the zones of weak material which are present along the planes of schistosity, the prominent joint systems, the ground water, and seismic effects. The two quantitative methods of stability analysis which were used are the modified method of slices and the sliding block method.

The material in which the slopes are constructed was classified into three general zones for the purpose of performing the stability studies. These zones are soil, weathered rock, and relatively fresh rock. The zones are illustrated in Figures 2.8.1 and 2.8.2.

A review of the safety evaluation of the slopes as constructed is covered by subsection 2.9, "Slope Stability."

2.8.2.1.1 Soil The soil overburden in the vicinity of the top of the cut slopes extends to an average depth of about 20 ft. The soil is residual and consists of decomposed weathered schist. Occasional bands of relatively hard schist and quartz are present. Analyses indicated that the residual soil would be stable in a cut slope at an angle of one and one-half horizontal to one vertical, and they have been successfully cut to this slope.

CHAPTER 02 2.8-1 REV. 21, APRIL 2007

PBAPS UFSAR 2.8.2.1.2 Weathered Rock This zone is present below the soil in the cut slopes. The thickness of this zone varies from roughly 5 to 75 ft. The material in this zone consists of moderately hard schist with many seams of soft highly weathered rock. Most of the highly weathered seams are less than 6 ft in width and constitute less than 25 percent of the material in this zone. The material in the seams increases in hardness and strength with depth.

The highly weathered seams occur parallel to the schistosity. The dip of the schistosity ranges from 60 to 70 deg toward the southeast. Prominent joints are also present in this material.

However, field studies indicate that most of the joints are tight and have soft seams.

A cut slope of one-half horizontal to one vertical was initially recommended for this zone. It became apparent during excavation that much of the zone was more highly weathered than the borings had indicated and it was decided to flatten the slope in this region to 1 on 1. Figures 2.8.1 and 2.8.2 show the cut slope as constructed.

2.8.2.1.3 Relatively Fresh Rock Relatively fresh rock is exposed in the lower portion of the slopes. This material is primarily hard schist with only a few seams of weathered rock parallel to the schistosity. Most of these seams are very narrow. Cut slopes of one-half horizontal to one vertical were recommended in this material.

The one-half horizontal to one vertical slope on the north side of the site is roughly parallel to the schistosity, and the recommended slope has been cut. On the west side of the site, the cut slope is nearly normal to the strike of the schistosity, and some weathered areas have been encountered which have ravelled and slightly flattened. The one-half to one slopes proved to be satisfactory.

2.8.2.2 Benches Benches were used for the major cut slopes to provide access to the slopes and to provide a means for catching rock fragments that might fall from the slopes above. A distance of 40 to 50 ft corresponding generally to the levels of changing material was chosen for the vertical distance between benches. A width of 12 CHAPTER 02 2.8-2 REV. 21, APRIL 2007

PBAPS UFSAR ft was selected for the benches as the narrowest, which would provide easy access to the slopes. The upper bench between the soil and weathered rock slopes is stable and is performing its desired function. A concrete lined ditch has been constructed against the toe of the soil slope to collect the water falling on the seeded slope and convey it to the south for disposal. The bench between the weathered and fresh rock slopes is very irregular because of the aforementioned flattening of some portions of the lower slope.

2.8.3 Surface Ravelling and Rock Falls Exposure of the cut face of the rock slopes indicates that some parts of the Peters Creek schist weather more rapidly than others.

The most rapid weathering occurs in the most fractured material.

The effect of weathering is to cause ravelling of the surface and debris to fall from the slope. The ravelling tends to undercut the quartzite seams present in the Peters Creek schist and to locally oversteepen the slope. Thus the possibility of minor rock falls must be considered.

Surface ravelling presents no danger to the reactor facilities.

However, there is concern for the safety of the personnel and some equipment in the event of a rock fall. Consequently, a protective chain-link fence at the base of the slope is provided and barriers are built around equipment as required.

2.8.4 Rock Blasting Blasting studies, including a field testing program, were made prior to general production blasting in order to develop blasting techniques and to set limits on the seismic disturbances which could be tolerated by existing structures. Blasting was carried out successfully with no significant disturbances to Unit 1 operations.

The test blasting program was conducted at the site in a pit about 750 ft north of Unit 1. The most significant information developed from the test program was blast attenuation curves.

These curves are shown in Figure 2.8.3.

As developed for the test program, the criteria that the particle velocity at Unit 1 should not exceed 1 ips and that the particle acceleration should not exceed 5 percent of gravity were used as a guide for the initial blasting operations.

CHAPTER 02 2.8-3 REV. 21, APRIL 2007

PBAPS UFSAR Specialized techniques were used during the blasting operation to reduce the transmission of seismic energy.

Presplitting was successfully used to obtain stable steep cuts where desirable.

All blasting operations were observed by an engineering geologist from Dames and Moore, and monitored using Sprengnether seismograph recording equipment. The specialized blasting procedures were modified, as required, in the field considering the actual conditions which were encountered.

2.8.5 Dewatering Ground water was encountered in a number of places in the cut slopes and in the foundation area.

The slopes intersect the original ground water table. This results in seeps and springs occurring at many of the open joints and at a few of the zones containing highly weathered material.

The locations of these seeps and springs changed as the excavation deepened. The ground water table may ultimately stabilize to intersect the cut slope near the toe.

Even where springs are not present, the ground water surface may be close enough to the surface of the cut slopes to introduce uplift forces and seepage pressures and thereby reduce the resistance to sliding along joint surfaces. To minimize the possibility of detrimental ground water pressures, long horizontal drains are installed in the slopes. The drains have been observed to be effective.

Selected drain holes also accommodate rock strain measuring instrumentation. The instrumentation is described in paragraph 2.9.9.

A small amount of dewatering was required in the deep foundation area. Sump pumps installed in the excavation were adequate for dewatering purposes. Most of the water came from the river side with only a minor quantity coming from the ground water in the area to the west. The river water could enter the excavation through joints and seams of weathered material in the rock, through newly placed fill material, and through the river-deposited silt overlying the bedrock in this area.

CHAPTER 02 2.8-4 REV. 21, APRIL 2007

PBAPS UFSAR 2.8.6 Backfilling In general, material for required backfilling operations was available in sufficient quantities from the higher portions of the site. The upper residual soil zone contains suitable material for backfill where soil is required. All soil backfill and other fill which is utilized for structural support is compacted to a density of at least 95 percent of the maximum density obtainable by the American Association of State Highway Officials (AASHO) Method of Compaction (T-180). In certain areas, particularly around the circulating water pipes, and adjacent to deep walls, imported backfill was used.

In general, the two rock zones provided material of adequate quality and size for general rock fill and rip-rap purposes. The rock tended to break along schistosity planes and form long tabular pieces. Care was taken to minimize the breakup of the rock used.

CHAPTER 02 2.8-5 REV. 21, APRIL 2007

PBAPS UFSAR 2.9 SLOPE STABILITY 2.9.1 General The slopes to the west of Units 2 and 3 are cut into the Peters Creek schist. The material in the cut grades from an overburden of soils derived by weathering of the underlying schist, through a zone of material which is weathered to various degrees, into sound and relatively fresh rock. The upland at the north end of the slope is at about Elevation 300.0 ft (C.D.) with the main toe of the excavation at about Elevation 135.0 ft. Portions of the excavation for the reactor extend to about Elevation 90.0. This subsection is concerned with the long-term stability of the main cut slopes.

The slope stability analyses discussed herein were performed by Dames and Moore.

2.9.2 Rock Character Bedrock at the site is the Peters Creek schist. The rock is greenish-gray to white, foliated, chlorite schist interbedded with seams and bands of quartzite that range up to 6 ft in thickness.

The upper zone of the bedrock formation has been altered by weathering to a friable material containing ribs of relatively unweathered rock. The interface between the overlying residual soil and the highly weathered rock is irregular and slopes upward to the north. Hard, fresh schist is found below the highly weathered zone.

The Peters Creek formation is characterized by thin lenticular bedding and strong flow cleavage resulting in a well developed schistosity. Mapping of the exposed areas of the schist indicates that along the long face of the cut in the vicinity of Units 2 and 3, the predominant strike of the schistosity and cleavage partings parallel to the schistosity is between North 55 deg East and North 65 deg East. The strike of the schistosity rotates to about North 35 deg East as the northern end of the cut is approached, and rotates to about North 40 deg East in the neighborhood of the south end of the cut. The dip of the schistosity is between 60 and 70 deg to the southeast over the entire site.

There is a general change in the character of the rock exposed in the face of the cut at about Plant Coordinate North 1350; to the north, the material is sound and relatively unweathered while to the south the rock is moderately to severely weathered and highly CHAPTER 02 2.9-1 REV. 21, APRIL 2007

PBAPS UFSAR jointed. South of Plant Coordinate North 1350, the jointing and fracturing is so extensive that small blocks have been formed and the stability of the slope is expected to be governed by the mass movement of a blocky, particulate mass of rock.

The following "major" joint patterns were mapped in the area south of Plant Coordinate North 1350 (Figure 2.7.1):

Strike Dip North 50 deg West 60 deg (East)

North 20 deg West 67 deg (West)

North 30 deg East Near vertical North 60 deg West Near vertical In addition to the joint patterns listed above, other minor fractures are apparent. Neither the major nor the minor joints appear to be continuous over large areas. The effect of the jointing is to produce numerous, rather small, blocks of rock.

North of Plant Coordinate North 1350 (Figure 2.7.1), the principal joint systems are:

Strike Dip North 30 deg West Near vertical North 80 deg West 0 to 10 deg (North)

Additional minor joint patterns have been mapped, but they are discontinuous and considered to be unimportant with respect to the overall stability of the slopes.

As anticipated, the rock slopes have been found to be water-bearing. Ground water seepage is evident at several points along the slope. During the early stage of construction, a series of drains was installed in the slopes and individual flows as large as 1 to 2 gpm have been measured at the drains. The water is flowing from joint planes and from the planes of foliation.

Readings after completion of the slope indicate very small water flow, less than 1/2 gpm per drain.

CHAPTER 02 2.9-2 REV. 21, APRIL 2007

PBAPS UFSAR 2.9.3 Geometry of Constructed Slopes The slopes incorporated in the plant design are shown in Table 2.9.1.

An inspection of the slopes was made in order to determine if the as-built slope angles conform to the design angles. The field measurements revealed that the as-built slopes are in general agreement with the design slopes.

Local areas of oversteepening and some areas of overhanging rock were noted between Elevations 135.0 ft and 165.0 ft and Plant Coordinates North 900 and North 1400. In areas where the oversteepened rock was loose and blocky, the loose material was removed.

2.9.4 Stability Analysis In order to evaluate the stability of a rock mass, it is necessary to consider the possibility that failure will take place by sliding of individual, large blocks of rock formed by intersecting foliation and fracture surfaces, and also the possibility that the rock mass is sufficiently fractured that it can act much like a soil mass and fail along some deep, curved, surface of sliding.

For cuts in most rocks, it is unnecessary to consider failure due to over-stressing of the intact material because its strength is too high to present any stability problems.

Graphical and analytical techniques are available for the solution of the sliding block problem, provided that the structure of the rock mass is known and there is some information about the shearing resistance of the rock along fracture surfaces.

Similarly, the possibility of a deep-seated failure along a curved surface of sliding can be evaluated by graphical and analytical techniques. Because failure along curved surfaces of sliding involves movements along fracture surfaces that may be arbitrarily oriented, a statistically valid value of the gross shearing resistance of the fractured rock mass must be introduced into the analysis. This value of the shear strength is different from the value utilized in the sliding block analysis.

A valuable indication of the stability of a rock slope can be obtained through use of the recently developed method of finite elements. This method permits evaluation of the elastic response of a discontinuous medium to stresses produced by such factors as excavation and earthquakes. Although it is an elastic analysis, CHAPTER 02 2.9-3 REV. 21, APRIL 2007

PBAPS UFSAR it does provide an indication of the overall stability of the slope and the potential modes by which failure could occur.

2.9.5 Rock Properties A large number of compression and tension tests were performed on the rock cores extracted from the borings drilled at the site. The results of these tests indicate that the Peters Creek schist exhibits the average strength properties shown in Table 2.9.2.

2.9.6 Sliding Block Analyses The rock structure at this site is favorably oriented and almost precludes the possibility of major movements of large blocks. The orientation of the major joint systems north of Plant Coordinate North 1350 and the direction of the strike of the plane of schistosity are such that no sliding wedges of significant dimensions are formed by the intersection of inclined joints.

Instead, massive, stable blocks are produced by the intersection of the schistosity and the joints. In the northwest corner of the excavation, the cut face is nearly parallel to the plane of schistosity. However, in this area, the face of the slope has been cut at an angle equal to or flatter than the minimum 60 deg southeast dip of the schist. Therefore, there is little likelihood of any large-scale instability due to sliding along the planes of schistosity and fracture.

South of Plant Coordinate North 1350, the intersections of the joint systems form small blocks that are considered in the next paragraph.

2.9.7 Curved Surface of Sliding Analyses Failure along a curved surface of sliding was considered to be possible in the area south of Plant Coordinate North 1350. In this region, the rock is moderately to severely weathered. The stability of the slope was analyzed by assuming that failure will occur along a circular surface of sliding. A computer solution, employing the "Method of Slices," was used to find the failure surface having the minimum factor of safety.

The analyses included a horizontal seismic acceleration of 0.12g and a vertical acceleration of 0.08g. The ground water table was assumed to be at Elevation 250.0 ft at a distance of about 400 ft from the toe of the cut, which is the highest level observed in the borings in this area, and to decline toward the face of the cut at a slope of 4 horizontal to 1 vertical.

CHAPTER 02 2.9-4 REV. 21, APRIL 2007

PBAPS UFSAR The conservative shear strength parameters listed in Table 2.9.3 were assumed for the soil-rock system. A measure of the degree of conservatism applied in the analyses can be obtained by comparing the parameters in Table 2.9.3 with the rock properties given in Table 2.9.2. The soil-rock profile used in the analysis is shown in Figure 2.9.1.

Assuming the worst condition for the stability of the slope occurs, and using the conservative strength parameters presented in Table 2.9.3, the factor of safety exceeds 1.7 in the absence of earthquake stresses, and exceeds 1.4 when earthquake conditions are considered.

The stability of the jointed rock in the less weathered zone was also investigated by considering near-circular failure surfaces that follow pre-existing joint planes. Once again, conservative shear strength parameters were assumed and an adequate factor of safety, larger than that obtained from the circular-surface analysis, was found.

It is concluded that deep-seated failures along curved surfaces of sliding are extremely improbable.

2.9.8 Finite Element Analyses Analyses of the elastic stresses and associated deflections of the rock slope were performed using the methods of finite elements. A portion of the slope south of Plant Coordinate North 1350 was modeled as a 4-layer system to reflect the decrease in weathering with depth below the ground surface. A horizontal acceleration of 0.12g and a vertical acceleration of 0.08g were introduced in the analyses.

The slope geometry and finite element mesh that were used are shown in Figure 2.9.2. The conservative parameters that were considered in the finite element analyses are listed in Table 2.9.4.

The results of the analyses are presented graphically on Figures 2.9.3, 2.9.4, and 2.9.5. The contours of maximum principal stress are shown in Figure 2.9.3 and the contours of minimum principal stress are shown in Figure 2.9.4. The directions of the principal stresses at selected points are indicated in Figure 2.9.5.

Examination of Figures 2.9.3, 2.9.4, and 2.9.5 reveals the expected concentration of compressive stress at the toe of the slope. A small tension zone was indicated in an area several CHAPTER 02 2.9-5 REV. 21, APRIL 2007

PBAPS UFSAR hundred feet from the face of the slope. This tension zone is an "end effect" common to this type of analysis and does not represent a true tension zone. This zone occurs sufficiently far from the cut face to have no effect on the calculated stresses in the critical area near the face of the slope.

The highest value of the maximum principal stress, found near the toe of the slope, was 27,000 psf (about 187 psi). At the same point, the minor principal stress was 3,600 psf (25 psi) and the maximum shearing stress was 11,700 psf (81 psi). However, the shear strength of the rock, at this critical point and along the critical failure surface, is estimated from the test data to be at least 72,000 psf (500 psi).

Evaluation of the results of the finite element analyses leads to the conclusion that, even under severe earthquake conditions, there is a large margin of safety against deep-seated failure of the rock material.

2.9.9 Bore Hole Extensometers Twenty-four bore hole extensometers, 35 to 80 ft long, were installed in the slope in June, 1968 to monitor the movements of the rock. The observations to January, 1970 indicate that some very small surface movements are occurring.

These movements of less than 1/10 in appear to be primarily at the rock surface and do not indicate deep-seated movement of the rock mass. Several shallow extensometers, 8 ft in length, have been installed and confirm that these minor movements are confined to the slope surface.

2.9.10 Conclusions The stability analyses indicate that the rock slopes are stable as constructed. No evidence of deep-seated instability has been found nor is there any indication that massive blocks will slide off the backslope.

CHAPTER 02 2.9-6 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.9.1 DESIGN SLOPES Material Slope Residual Soil Overburden 1 1/2 horizontal : 1 vertical Weathered Rock 1 horizontal : 1 vertical Relatively Fresh, Unweathered Rock 1/2 horizontal*: 1 vertical

• In those areas where the toe of the cut is parallel to the strike of the schistosity, the slope follows the plane of the schistosity.

CHAPTER 02 2.9-7 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.9.2 ROCK PROPERTIES Average Angle of Compressive Shearing Cohesion Strength Resistance Intercept (psi) (deg) (psi)

Failure through intact material 20,000 50 3,500 Failure along plane of schistosity 2,500 45 500 CHAPTER 02 2.9-8 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.9.3 PARAMETERS USED IN CURVED SURFACE STABILITY ANALYSES Angle of Internal Cohesion Elevation Density Friction Intercept Material (ft) (pcf) (deg) (psi)

Soil Overburden Above 232 135 29* 0 Highly Weathered Schist 232 to 172 140 34 9 Moderately Weathered Schist 172 to 120 150 40 17 Unweathered Schist Below 120 170 45 25

• Conservative value used in analyzing stability of overall slope.

The actual angle of internal friction is appreciably higher and adequate to minimize local sloughing even under earthquake conditions.

CHAPTER 02 2.9-9 REV. 21, APRIL 2007

PBAPS UFSAR TABLE 2.9.4 PARAMETERS USED IN FINITE ELEMENT ANALYSES Modulus of Density Elasticity Poisson's Material (pcf) (psi) Ratio Soil Overburden 135 0.7 x 104 0.33 Highly Weathered Schist 140 0.1 x 106 0.30 Moderately Weathered Schist 150 0.3 x 106 0.30 Unweathered Schist 170 1.0 x 106 0.28 CHAPTER 02 2.9-10 REV. 21, APRIL 2007