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Annual Radiological Environmental Operating Report 82, January 1, 2024 Through December 31, 2024
	ML25140A114
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Site:	Peach Bottom
Issue date:	05/19/2025
From:	; Exelon Generation Co
To:	; Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation
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Peach Bottom Atomic Power Station 2024 Document Number: 50-171, 50-277, 50-278 Annual Radiological Environmental Operating Report

Annual Radiological Environmental Operating Report YEAR: 2024 Page 1 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station TABLE OF CONTENTS 1.0 LIST OF ACRONYMS AND DEFINITIONS................................................................................ 3 2.0 Executive Summary................................................................................................................... 4 2.1 Summary of

Conclusions:

............................................................................................... 5

3.0 INTRODUCTION

........................................................................................................................ 7 4.0 Site description and sample locations........................................................................................ 8 5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM REQUIREMENTS................ 9 6.0 MAPS OF COLLECTION SITES.............................................................................................. 16 7.0 Reporting Levels for radioactivity concentrations in environmental samples............................. 19 8.0 SAMPLING PROGRAM, PROGRAM MODIFICATION AND INTEPRETATION OF RESULTS................................................................................................................................ 20 8.1 Environmental Direct Radiation Dosimetry Results....................................................... 20 8.2 Air Particulate and Radioiodine Sample Results........................................................... 21 8.3 Waterborne Sample Results......................................................................................... 22 8.4 Ingestion Pathway Sample Results............................................................................... 25 9.0 LAND USE CENSUS............................................................................................................... 26 10.0 SAMPLE DEVIATIONS, ANOMALIES AND UNAVAILABILITY................................................ 27 11.0 OTHER SUPPLEMENTAL INFORMATION............................................................................. 28 11.1 NEI 07-07 Onsite Radiological Groundwater Monitoring Program................................. 28 11.2 Independent Spent Fuel Storage Installation (ISFSI) Monitoring Program.................... 29 11.3 Corrections to Previous Reports................................................................................... 29 12.0 Bibliography............................................................................................................................. 30 TABLES Table 1, Radiological Environmental Monitoring Program - Direct Radiation......................................... 9 Table 2, Radiological Environmental Monitoring Program - Airborne................................................... 10 Table 3, Radiological Environmental Monitoring Program - Waterborne............................................. 11 Table 4, Radiological Environmental Monitoring Program - Ingestion.................................................. 12 Table 5, REMP Sampling Locations - Direct Radiation........................................................................ 14 Table 6, Reporting Levels for Radioactivity Concentrations in Environmental Samples....................... 19 Table 7, Maximum Values for the Limit of Detection............................................................................ 19 Table 8, Land Use Census - Nearest Receptors within 5 miles........................................................... 27 Table 9, Sample Deviation Summary................................................................................................... 28 Table 10, Monthly Drinking Water Results........................................................................................... 34 Table 11, Monthly Surface Water Results............................................................................................ 35 Table 12, Monthly Vegetation Results.................................................................................................. 36 Table 13, Monthly Milk Results............................................................................................................ 38 Table 14, Weekly Airborne I-131 Results............................................................................................. 39 Table 15, Weekly Airborne Gross Beta Results................................................................................... 43 Table 16, Quarterly Isotopic Data for Air Filters, Water, Milk and Fish................................................. 47

Annual Radiological Environmental Operating Report YEAR: 2024 Page 2 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 17, Gamma Isotopic Results for Fish......................................................................................... 48 Table 18, Gamma Isotopic Results for Sediment................................................................................. 48 Table 19, CGS Cross Check Intercomparison Results......................................................................... 53 Table 20, Interlaboratory Split Sample Results.................................................................................... 59 Table 21, Comparison of Gross Beta Results from Split Samples of 1Z and 1A.................................. 64 Table 22, Comparison of I-131 Results from Split Samples of 1Z and 1A............................................ 66 Table 23, Groundwater Protection Results for the Specific Analytes Analysis Program....................... 76 Table 24, Groundwater Protection Results for Tritium.......................................................................... 77 Table 25, Tritium Precipitation Results................................................................................................. 78 FIGURES Figure 1, Potential exposure pathways to Members of the Public due to Plant Operations [7]............... 7 Figure 2, REMP Sample Locations (Near Field/Site Boundary)........................................................... 16 Figure 3, REMP Sample Locations (Far Field)..................................................................................... 17 Figure 4, REMP Sample Locations (Onsite)......................................................................................... 18 Figure 5, Air Particulate: Analysis for Gross Beta, Average for All Indicator vs. Control Location......... 21 Figure 6, Surface Water Tritium Results.............................................................................................. 22 Figure 7, Comparison of Beta Emitters in Split Samples CGS and TBE Analysis................................. 23 Figure 8, Drinking Water Gross Beta Samples Control vs. Indicator Comparison................................ 24 Figure 9, Drinking Water Tritium Sample Results................................................................................. 25 Figure 10, Surface Water and Overburden RGPP Monitoring Locations.............................................. 73 Figure 11, Bedrock Seep and Bedrock RGPP Monitoring Locations.................................................... 74 Figure 12, Precipitation Recapture Sample Locations.......................................................................... 75 ATTACHMENTS, Data Table Summary.................................................................................................... 33, Complete Data Table for All Analysis Results Obtained In 2024................................... 34, Cross Check Intercomparison Program......................................................................... 49, Environmental Direct Radiation Dosimetry Results....................................................... 68 : Radiological Groundwater Protection Program.............................................................. 70

Annual Radiological Environmental Operating Report YEAR: 2024 Page 3 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 1.0 LIST OF ACRONYMS AND DEFINITIONS

1.

Airborne Activity Sampling: Continuous sampling of air through the collection of particulates and radionuclides on filter media.

2.

ARERR: Annual Radioactive Effluent Release Report

3.

AREOR: Annual Radiological Environmental Operating Report

4.

BWR: Boiling Water Reactor

5.

Composite Sample: A series of single collected portions (aliquots) analyzed as one sample. The aliquots making up the sample are collected at time intervals that are very short compared to the composite period.

6.

Control: A sampling station in a location not likely to be affected by plant effluents due to its distance and/or direction from the station.

7.

Curie (Ci): A measure of radioactivity; equal to 3.7 x 1010 disintegrations per second, or 2.22 x 1012 disintegrations per minute.

8.

Direct Radiation Monitoring: The measurement of radiation dose at various distances from the plant is assessed using Thermoluminescent Dosimeters (TLD), Optically Stimulated Luminescence Dosimeters (OSLD) and pressurized ionization chambers.

9.

EPA: Environmental Protection Agency

10.

GPI: Groundwater Protection Initiative

11.

Grab Sample: A single discrete sample drawn at one point in time.

12.

Indicator: A sampling location that is likely to be affected by plant effluents due to its proximity and/or direction from the plant.

13.

Ingestion Pathway: The ingestion pathway includes milk, fish, drinking water and garden produce. Also sampled (under special circumstances) are other media such as vegetation or animal products when additional information about particular radionuclides is needed.

14.

ISFSI: Independent Spent Fuel Storage Installation

15.

Lower Limit of Detection (LLD): An a priori measure of the detection capability of a radiochemistry measurement based on instrument setup, calibration, background, decay time, and sample volume. An LLD is expressed as an activity concentration. The MDA is used for reporting results. LLD are specified by a regulator, such as the NRC and are typically listed in the ODCM.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 4 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

16.

MDA: Minimum Detectable Activity. For radiochemistry instruments, the MDA is the a posteriori minimum concentration that a counting system detects. The smallest concentration or activity of radioactive material in a sample that will yield a net count above instrument background and that is detected with 95%

probability, with only five % probability of falsely concluding that a blank observation represents a true signal.

17.

MDC: Minimum Detectable Concentration. Essentially synonymous with MDA for the purposes of radiological monitoring.

18.

Mean: The sum of all of the values in a distribution divided by the number of values in the distribution, synonymous with average.

19.

Microcurie: 3.7 x 104 disintegrations per second, or 2.22 x106 disintegrations per minute.

20.

N/A: Not Applicable

21.

NEI: Nuclear Energy Institute

22.

NIST: National Institute of Standards and Technology.

23.

NRC: Nuclear Regulatory Commission

24.

ODCM: Offsite Dose Calculation Manual

25.

OSLD: Optically Stimulated Luminescence Dosimeter

26.

pCi/L: picocuries / Liter

27.

PWR: Pressurized Water Reactor

28.

REMP: Radiological Environmental Monitoring Program

29.

TLD: Thermoluminescent Dosimeter

Annual Radiological Environmental Operating Report YEAR: 2024 Page 5 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 2.0 EXECUTIVE

SUMMARY

Peach Bottom Atomic Power Station Radiological Environmental Monitoring Program (REMP) was established prior to the station becoming operational to provide information on background radiation present in the area. The goal of PBAPS REMP is to evaluate the impact of the station on the environment. Environmental samples from different media are monitored as part of the program in accordance with specifications detailed in the Offsite Dose Calculation Manual (ODCM) and ODCM Specifications (ODCMS). The program compares data from Indicator locations near the plant to control locations farther away from the site to assess operation impacts.

The Annual Radiological Environmental Operating Report (AREOR) provides data obtained through analyses of environmental samples collected at PBAPS for the reporting period of January 1st through December 31st, 2024. During that time period 1608 analyses were performed on 1296 samples. In assessing all the data gathered for this report and comparing these results with preoperational data and/or 10-year average values, it was concluded that the operation of PBAPS did not result in detection of plant related radionuclides in the environment.

Results of OSLD measurements are listed in Attachment 4. In 2019, six years of OSLD data (2012-2018) were re-evaluated with the new methodology presented in Constellation Nuclear corporate procedure CY-AA-170-1001, to determine a background dose and baseline for each location in the REMP. Detectable Facility Dose is any normalized net dose above the sum of the normalized mean background dose and minimum differential dose (BQ/A + MDDQ/A) and is reported both quarterly and annually for each location. Quarterly and Annual Normalized Net Dose for each location is reported in Attachment 4. The net dose is calculated by subtracting a control transit dosimeter and extraneous dose rather than a control or background location dose. The net dose is normalized to a standard 91-day quarter. Detectable annual facility related dose was identified at the ISFSI dosimeter location, 1R, (described below). There is no detectable ambient gamma radiation to the members of the public due to PBAPS operations.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 6 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 2.1 Summary of

Conclusions:

No measurable activities above background levels were detected. All values were consistent with historical results which indicate no adverse radiological environmental impacts associated with the operation of PBAPS. Naturally occurring radionuclides are present in the Earth's crust and atmosphere and exists in detectable quantities throughout the world. It is common to detect naturally occurring radionuclides in many of the samples collected for REMP. Some examples of naturally occurring radionuclides that are frequently seen in samples are potassium-40, beryllium-7, actinium-228 (present as a decay product of radium-228), and radium-226.

Additionally, some relatively long-lived anthropogenic radioisotopes, such as strontium-90 and cesium-137, are also seen in some REMP samples; these radionuclides exist in measurable quantities throughout the world as a result of fallout from historic atmospheric nuclear weapons testing and other nuclear events worldwide such as Fukushima and Chernobyl. Detailed information on the exposure of the U.S. population to ionizing radiation can be found in NCRP Report No. 160 [1].

In 2024, the doses from both liquid and gaseous effluents were conservatively calculated for the Maximum Exposed Member of the Public due to PBAPS Operation. Doses calculated were well below all Offsite Dose Calculations Manual (ODCM) limits. The results of those calculations were as follows:

Annual Radiological Environmental Operating Report YEAR: 2024 Page 7 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

Annual Radiological Environmental Operating Report YEAR: 2024 Page 8 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

3.0 INTRODUCTION

The Radiological Environmental Monitoring Program (REMP) provides data on measurable levels of radiation and radioactive materials in the environment. This program also evaluates the relationship between quantities of radioactive materials released from the plant and resultant doses to individuals from principal pathways of exposure. In this capacity, REMP provides a check on the effluent release program and dispersion modeling to ensure that concentrations in the environment due to radioactive effluents conform to the As Low as Is Reasonably Achievable (ALARA) design objectives of 10 CFR 50, Appendix I [2], and implements the requirements of Section IV.B.2 and IV.B.3 of Appendix I. REMP is designed to conform to the Nuclear Regulatory Commission (NRC) Regulatory Guide 4.1 [3], NUREG 1301/1302

[4] [5], and the 1979 NRC Branch Technical Position [6].

Figure 1, Potential exposure pathways to Members of the Public due to Plant Operations [7]

Quality assurance aspects of the sampling program and OSLD data collection are conducted in accordance with Regulatory Guides 4.15 [8] and 4.13 [9]. REMP also adheres to the requirements of PA, PBAPS Technical Specifications, and Offsite Dose Calculation Manual (ODCM). These governing documents dictate the environmental sampling, sample analysis protocols, data reporting and quality assurance requirements for the environmental monitoring program.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 9 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station The Annual Radiological Environmental Operating Report provides summaries of the environmental data from exposure pathways, interpretations of the data, and analyses of trends of the results. Routinely monitored pathways include ingestion, inhalation, and direct radiation. Routes of exposure are based on site specific information such as meteorology, receptor locations, and water usage around the plant.

4.0 SITE DESCRIPTION AND SAMPLE LOCATIONS PBAPS is located along the Susquehanna River between Holtwood and Conowingo Dams in Peach Bottom Township, York County, Pennsylvania. The initial loading of fuel into Unit 1, a 40 MWe (net) high temperature gas-cooled reactor, began on 5 February 1966, and initial criticality was achieved on 3 March 1966. Shutdown of Peach Bottom Unit 1 for decommissioning was on 31 October 1974. For the purposes of the monitoring program, the beginning of the operational period for Unit 1 was considered to be 5 February 1966. A summary of the Unit 1 preoperational monitoring program was presented in a previous report (1). PBAPS Units 2 and 3 are boiling water reactors, each with a power output of approximately 1385 MWe. The first fuel was loaded into Peach Bottom Unit 2 on 9 August 1973. Criticality was achieved on 16 September 1973 and full power was reached on 16 June 1974. The first fuel was loaded into Peach Bottom Unit 3 on 5 July 1974. Criticality was achieved on 7 August 1974 and full power was first reached on 21 December 1974.

Preoperational summary reports (2)(3) for Units 2 and 3 have been previously issued and summarize the results of all analyses performed on samples collected from 5 February 1966 through 8 August 1973.

PBAPS sampling media are selected based on site specific information such as meteorology, receptor locations, and water usage around the plant. Sampling and analysis frequencies are documented in the Offsite Dose Calculation Manual and site procedures. Required sampling, analysis frequencies and location of sample collected are captured in the following tables and figures:

Table 1, Radiological Environmental Monitoring Program - Direct Radiation Table 2, Radiological Environmental Monitoring Program - Airborne Table 3, Radiological Environmental Monitoring Program - Waterborne Table 4, Radiological Environmental Monitoring Program - Ingestion Table 5, REMP Sampling Locations - Direct Radiation Figure 2, REMP Sample Locations (Near Field/Site Boundary)

Figure 3, REMP Sample Locations (Far Field)

Figure 4, REMP Sample Locations (Onsite)

Annual Radiological Environmental Operating Report YEAR: 2024 Page 10 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM REQUIREMENTS Table 1, Radiological Environmental Monitoring Program - Direct Radiation Requirement Sample Location Description, Distance, and Direction Sampling Collection/

Frequency Type and Frequency of Analyses Direct Radiation At least 40 routine monitoring stations either with two or more dosimeters or with one instrument for measuring and recording dose rate continuously to be placed as follows:

An inner ring of stations in the general area of the SITE BOUNDARY and an outer ring in the 3 to 6 mile range from the site. A station is in each sector of each ring except as dictated by local geography. The balance of the stations are in special interest areas such as population centers, nearby residences, schools, and in areas to service as control locations.

See Table 5 Quarterly (Every 92 days)

Gamma dose/Quarterly

Annual Radiological Environmental Operating Report YEAR: 2024 Page 11 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 2, Radiological Environmental Monitoring Program - Airborne Requirement Sample Location Description, Distance, and Direction Sampling Collection/

Frequency Type and Frequency of Analyses Airborne Radioiodine and Particulates Samples from 5 locations:

3 samples from close to the SITE BOUNDARY locations (in different sectors) of the highest calculated annual average ground level D/Q.

1 sample from the vicinity of a community having the highest calculated annual average ground level D/Q.

1 sample from a control location unlikely to be affected by the plant.

1Z 1,500 feet SE of site 1A^,QC collocated with 1Z Weather Station #1 1B 2,500 feet NW of site Weather Station #2 1C 4,700 feet SSE of site South Sub Road 3A 19,300 feet SW of site Delta Station 5H2 C 162,400 feet NE of site Manor Substation (LGS)

Approximately 1 cfm continuous flow through glass fiber filter which is collected weekly.

A TEDA impregnated flow-through cartridge is connected to air sampler and is collected weekly at site filter change.

Continuous sampler operation with sample collection every 7 days or required by dust loading, whichever is more frequent.

Gross beta analysis on each weekly sample.

Gamma spectrometry shall be done when gross beta exceeds ten times the yearly mean of control station value.

Gross beta analysis done 24 hr. after sampling to allow for Radon and Thoron daughter decay.

Gamma Spec on quarterly (92 days) composite by location.

Radioiodine canisters: I-131 analysis every 7 days C Indicates a Control location QC Indicates a Quality Control duplicate sample location

^ Indicates a sample location that is sampled and analyzed routinely, but is not listed as a sample location in the ODCM

Annual Radiological Environmental Operating Report YEAR: 2024 Page 12 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 3, Radiological Environmental Monitoring Program - Waterborne Requirement Sample Location Description, Distance, and Direction Sampling Collection/

Frequency Type and Frequency of Analyses Surface Water 1 sample upstream (control) and 1 sample downstream (indicator) 1LL C 1,200 feet ENE of site U2 and U3 Intake Composite 1MM 5,500 feet SE of site Canal Discharge Sample collected from a continuous water sampler, monthly. In event, sampler is inoperable, grab samples will be collected each calendar day until sampler returned to service.

Gamma isotopic analysis monthly; H-3 on quarterly composite Drinking Water 1 sample of each of 1 to 3 of the nearest water supplies that could be affected by its discharge.

1 sample from a control location.

4L 45,900 feet SE of site Conowingo Dam 6I C 30,500 feet NW of site Holtwood Dam 13B 13,300 feet ESE of site Susquehanna Pumping Station Sample collected from a continuous water sampler, monthly. In event, sampler is inoperable, weekly grab samples will be collected until sampler returned to service.

Gross beta and gamma isotopic monthly, H-3 on quarterly composite Sediment from Shoreline 1 sample from downstream area with existing or potential recreational value.

4J 7,400 feet SE of site Down River from Plant Discharge Area 4T^ 41,800 feet SE of site Conowingo Pond near Conowingo Dam 6FC^ 31,500 feet NW of site Holtwood Dam A sediment sample is taken down stream of discharge semi-annually.

Gamma isotopic analysis of each sample C Indicates a Control location

^ Indicates a sample location that is sampled and analyzed routinely, but is not listed as a sample location in the ODCM

Annual Radiological Environmental Operating Report YEAR: 2024 Page 13 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 4, Radiological Environmental Monitoring Program - Ingestion Requirement Sample Location Description, Distance, and Direction Sampling Collection/

Frequency Type and Frequency of Analyses Milk:

Samples from milking animals in 3 locations within 3 miles distance having the highest dose potential.

1 sample from milking animals at a control location (unlikely to be affected by the plant).

M-13F C 32,600 feet W of site M-11A 4,900 feet SW of site M-7D 19,100 feet SE of site M-15B 9,500 feet NW of site M-4C 10,900 feet ENE of site M-1C 15,000 feet N of site Sample of fresh milk is collected from each farm biweekly when cows are on pasture (April through October), monthly at other times.

I-131 analyses on each sample.

Gamma isotopic analysis or Cs-134, Cs-137 by chemical separation quarterly M-3D^ 18,500 feet NE of site M-1F^C 46,100 feet N of site M-3B^ 10,500 feet NE of site M-9G^ 89,200 feet S of site M-15G^ 9,500 feet NW of site Sample of fresh milk is collected from each farm quarterly.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 14 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 4, Radiological Environmental Monitoring Program - Ingestion Requirement Sample Location Description, Distance, and Direction Sampling Collection/

Frequency Type and Frequency of Analyses Fish and Invertebrates:

1 sample of each commercially and recreationally important species in vicinity of discharge point when available.

1 sample of same species in areas not influenced by plant discharge when available.

4 6,000-10,000 feet SE of site PBAPS Discharge Area 6 C 50,000-70,000 feet NNW of site Area not influenced by Plant Discharge Two species of recreationally important fish (predator and bottom feeder) sampled in season or semiannually if not seasonal.

Gamma isotopic analyses on edible portions.

Food Products:

Samples of 3 different kinds of broad leaf vegetation grown nearest offsite garden of highest annual average ground level D/Q if milk sampling is not performed.

1 sample of each of the similar broad leaf vegetation grown 15-30 km distant in the least prevalent wind direction if milk sampling is not performed.

1C 4,700 feet SSE of site 55 C 51,900 feet NE of site 2Q^ 9,504 feet SW of site 3Q^ 9,504 feet SW of site Samples of three (3) different kinds of broad leaf vegetation monthly when available if milk sampling is not performed.

Gamma isotopic and I-131 analysis C Indicates a Control location

^ Indicates a sample location that is sampled and analyzed routinely, but is not listed as a sample location in the ODCM

Annual Radiological Environmental Operating Report YEAR: 2024 Page 15 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 5, REMP Sampling Locations - Direct Radiation Site #

Location Type Sector Distance Description 1L Inner ring NE 1,100 feet Just before intake building on pipe by shoreline 1A Inner ring SE 1,500 feet Located at 1A air sample site on pole 2

Inner ring SE 4,700 feet Back corner of orchard walk thru woods to fenced cage at cliffs edge 1I Inner ring SSE 2,900 feet Walk on left side of perimeter fence around south sub station located attached to fence 1C Inner ring SSE 4,700 feet Located on pole at 1C air sample site 1J Inner ring S

4,000 feet Follow field dirt road to top of field & woods, on left side at edge of woods on pole 1F Inner ring SSW 2,900 feet Off Atom Rd. through gate, follow dirt rd. to top near powerlines inside fenced area on pole 40 Inner ring SW 8,000 feet Address 43 Atom Rd. behind house on end of wash line pole 1NN Inner ring WSW 2,700 feet Drive past N. Substation on right maint. buildings drive past &

on pole in field 1H Inner ring W

3,200 feet At N. Substation drive thru gate & turn to right follow field road to pole on right 1G Inner ring WNW 3,100 feet At N. Substation on left side of perimeter fence follow along fence to where attached to fence 1B Inner ring NW 2,500 feet Located on pole at 1B air sample site 1E Inner ring NNW 3,000 feet Onsite behind Dorsey Park boat launch inside fenced area on pole 1K Inner ring SW 4,700 feet Off Booker Rd. Ben Blank milk farm behind house on pole 1P Inner ring ESE 2,200 feet Onsite located on fence near shoreline by cooling tower #2 15 Outer ring N

19,300 feet Off Silver Spring Rd. turn right on dirt lane in field inside fenced area on pole 22 Outer ring NNE 12,500 feet Along Eagle Rd. under power line tower on pole just off roadway 44 Outer ring NE 26,700 feet Along Goshen Rd. on pole just off roadway 32 Outer ring ENE 14,400 feet Along Slate Hill Rd. inside fenced area on pole 45 Outer ring ENE 18,500 feet Along Peach Bottom Rd. up farm lane in field on leg of Power line tower - Keeney Line 14 Outer ring E

10,300 feet Along Peters Creek Rd. on right inside fenced area on pole 17 Outer ring ESE 21,500 feet Along Riverview Rd. in field inside fenced area on pole 31A Outer ring SE 24,100 feet Along dirt Rd. Eckerman Rd. on left side on pole 4K Outer ring SE 45,900 feet On rooftop on West side of Conowingo Dam 23 Outer ring SSE 5,500 feet Off Burke Rd. turn into driveway & proceed into orchard located on pole near water tower

Annual Radiological Environmental Operating Report YEAR: 2024 Page 16 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 5, REMP Sampling Locations - Direct Radiation Site #

Location Type Sector Distance Description 27 Outer ring S

14,400 feet Along Cooper dirt Rd. along field edge on pole 48 Outer ring SSW 26,500 feet Along Route 136 Substation in Md. behind station in grass on pole 3A Outer ring SW 19,300 feet Located on pole outside of fenced area for 3A air station in Delta 49 Outer ring WSW 21,500 feet Along Route 74 S. turn onto September Lane follow dirt rd. to pole on right side along edge of field 50 Outer ring W

26,400 feet Along Route 851 W. to Trans Pipeline on left side of road outside of fence on a pole 51 Outer ring WNW 21,000 feet Along McKinley Rd. on fence at Sub Station 26 Outer ring NW 21,800 feet Along Slab Rd. park on right in field follow field fence line to Power Line Tower on leg of tower 6B Outer ring NW 30,400 feet At Holtwood Dam on rooftop of original powerhouse 42 Outer ring NNW 21,500 feet Across from Muddy Run Plant driveway located on fence along this driveway 43 Special interest NNE 26,200 feet Behind Rental business follow farm lane to pole on left 5

Special interest E

24,400 feet Near Wakefield off Pilottown Rd. inside fenced area on pole 16 Special interest E

67,100 feet Nottingham Substation on right side on pole 24 Special interest ESE 58,200 feet Harris Substation toward left side on fence 2B Special interest SSE 3,900 feet 870 Burke Rd. follow lane to house off left side of yard on T-pole 46 Special interest SSE 23,800 feet Off Flintville Rd. turn onto Bryce Lane dirt Rd. follow to pole on right side of lane 47 Special interest S

22,700 feet Off Susquehanna Hall Rd. turn into Scout camp take first dirt rd. on left follow to fence where attached 18 Special interest W

52,200 feet Near Fawn Grove Reids residence on pole in driveway 19C Special interest WNW 124,000 feet Red Lion, Pa. along Railwood Lane/Alley on T-pole 1T Special interest WNW 3,100 feet Along Lay Rd. near P.B. nuclear plant on T-pole near house C Control location

Annual Radiological Environmental Operating Report YEAR: 2024 Page 17 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 6.0 MAPS OF COLLECTION SITES Figure 2, REMP Sample Locations (Near Field/Site Boundary)

Annual Radiological Environmental Operating Report YEAR: 2024 Page 18 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 3, REMP Sample Locations (Far Field)

Annual Radiological Environmental Operating Report YEAR: 2024 Page 19 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 4, REMP Sample Locations (Onsite)

Annual Radiological Environmental Operating Report YEAR: 2024 Page 20 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 7.0 REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES Table 6, Reporting Levels for Radioactivity Concentrations in Environmental Samples Radionuclide Water (pCi/L)

Air Particulates or Gases (pCi/m3)

Fish (pCi/Kg-wet)

Milk (pCi/L)

Food Products (pCi/Kg-wet)

H-3 20,000 (1)

Mn-54 1,000 30,000 Fe-59 400 10,000 Co-58 1,000 30,000 Co-60 300 10,000 Zn-65 300 20,000 Zr-Nb-95 400 I-131 2 (2) 0.9 3

100 Cs-134 30 10 1,000 60 1,000 Cs-137 50 20 2,000 70 2,000 Ba-La-140 200 300 Table 7, Maximum Values for the Limit of Detection Radionuclide Water (pCi/L)

Air Particulates or Gases (pCi/m3)

Fish (pCi/Kg-wet)

Milk (pCi/L)

Food Products (pCi/Kg-wet)

Sediment (pCi/Kg-dry)

Gross Beta 4.0 0.01 H-3 2,000 (3)

Mn-54 15 130 Fe-59 30 260 Co-58, Co-60 15 130 Zn-65 30 260 Zr-95, Nb-95 30, 15 I-131 1 (4) 0.07 1

60 Cs-134 15 0.05 130 15 60 150 Cs-137 18 0.06 150 18 80 180 Ba-140, La-140 60, 15 15 1 For drinking water samples: If no drinking water pathway exists, a value of 30,000 pCi/L may be used.

2 If no drinking water pathway exists, a value of 20 pCi/l may be used 3 If no drinking water pathway exists, a value of 3,000 pCi/L may be used. Some states may require a lower LLD for drinking water sources-per 40 CFR 141 Safe drinking water ACT.

4 If no drinking water pathway exists, a value of 15 pCi/l may be used

Annual Radiological Environmental Operating Report YEAR: 2024 Page 21 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 8.0 SAMPLING PROGRAM, PROGRAM MODIFICATION AND INTEPRETATION OF RESULTS At most nuclear stations, data was collected prior to plant operation to determine background radioactivity levels in the environment. Annual data is routinely compared to preoperational and/or 10-year average values to determine if changes in the environs are present. Strict comparison is difficult to make due to fallout from historical nuclear weapon testing. Cesium-137 can be routinely found in environmental samples as a results of above ground nuclear weapons testing. It is important to note, levels of Cs-137 in environment are observed to fluctuate, for example as silt distributions shift due to natural erosion and transport processes, Cs-137 may or may not be observed in sediment samples.

In the following sections, results from direct radiation, air, water, and food products analyzed as part of REMP in 2024 will be discussed. Sampling program descriptions and deviations will also be discussed.

8.1 Environmental Direct Radiation Dosimetry Results Dose is measured as net exposure (field reading less transit reading) normalized to 91-day quarters. Data is treated and analyzed consistent with ANSI/HPS N13.37-2014, which compares the measured dose for each location to the baseline background dose for that location. Environmental dose rates vary by location, depending on geological and land use considerations, and remain relatively constant for any given location (unless land use changes). Some facilities observe seasonal variation in environmental doses. Baseline Background Doses have been determined for both quarterly and annual measurements at each location using historical field measurements.

ANSI/HPS N13.37-2014 uses the concept of minimum differential dose (MDD), which is the minimum facility-related dose that can be detected above background. Due to natural background variations and measurement sensitivities and uncertainties, minimum differential dose is not zero. MDD is calculated based on statistical performance of the dosimetry system in the environment and is site specific.

Normalized doses that exceed the Minimum Differential Dose value above the Baseline Background Dose are considered to indicate Facility-Related Dose; a quality assurance review is performed to verify that any results indicating Facility-Related Dose are accurate.

During the calendar year 2024, a total of 48 locations were monitored and data analyzed in accordance with the requirements in Table 1, Radiological Environmental Monitoring Program - Direct Radiation. Attachment 4, Environmental Direct Radiation Dosimetry Results, provides the annual direct radiation dosimetry analysis.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 22 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 8.2 Air Particulate and Radioiodine Sample Results Air particulate filters and charcoal canisters were collected from locations specified in Table 1, Radiological Environmental Monitoring Program - Direct Radiation. During the calendar year 2024, a total of 265 samples were collected and analyzed for gross beta, gamma emitters and iodine. Particulate samplers are used to continuously collect airborne particulates on a filter. The samples are analyzed for gross beta activity following filter changeout which occurs weekly. Gamma isotopic analysis is also performed on the samples collected at each location and is analyzed quarterly.

Radioiodine (I-131) analysis is performed weekly on radioiodine sample cartridges.

Air particulate samples were analyzed for concentrations of gross beta and gamma-emitting nuclides. Gross beta and cosmogenic naturally occurring beryllium-7 (Be-7) were detected at levels consistent with those detected in previous years. No fission or activation products were detected. High-sensitivity I-131 analyses were performed on weekly air samples. All I-131 results were less than minimum detectable activity.

Gross Beta results are plotted in Figure 5, below.

Figure 5: Air Particulate: Analysis for Gross Beta, Indicator Group 1 vs. Indicator Group 2 vs. Control Location Air particulate and radioiodine results from this monitoring period, 2024, were compared to 10 year average as shown in Figure 5, and there were no significant changes.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 23 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 8.3 Waterborne Sample Results 8.3.1 Surface Water (i.e., Bay, Lake etc.)

Composite water samples are collected monthly at the upstream control location and at the downstream indicator locations. Monthly composite samples are analyzed for gamma emitters. Aliquots from the monthly composites are combined to form a quarterly composite which is then analyzed for tritium. During the calendar year 2024, a total of 24 surface water samples were collected and analyzed in accordance with the requirements in the ODCM and shown in Table 3, Radiological Environmental Monitoring Program - Waterborne. Tritium concentrations in surface water were well below the EPA tritium drinking water limit of 20,000 pCi/L.

Figure 6, Surface Water Tritium Results, Indicator vs. Control vs EPA Limit

Annual Radiological Environmental Operating Report YEAR: 2024 Page 24 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 8.3.2 Beta Analysis Comparison; CGS vs. TBE 2024 Figure 7, Comparison of Beta Emitters in Split Samples CGS and TBE Analysis 8.3.3 Drinking Water A total of 36 drinking water samples were obtained in 2024. These samples were analyzed for gross beta, low level iodine, and gamma analysis monthly. These samples were analyzed for tritium quarterly in accordance with requirements in the ODCM and shown in Table 3, Radiological Environmental Monitoring Program -

Waterborne. Total gross beta activities detected were consistent with those detected in previous years. No other fission or activation products were detected. Tritium concentrations in drinking water were less than MDA, thus far below the EPA tritium drinking water limit of 20,000 pCi/L.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 25 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 8, Drinking Water Gross Beta Samples Control vs. Indicator Comparison

Annual Radiological Environmental Operating Report YEAR: 2024 Page 26 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 9, Drinking Water Tritium Sample Results: EPA Limit vs Indicator vs Control

Annual Radiological Environmental Operating Report YEAR: 2024 Page 27 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 8.3.4 Sediment from Shoreline Shoreline sediment collections were made in May and November of 2024 and analyzed for gamma-emitting isotopes. Samples are collected at both indicator and control locations. A total of 6 shoreline samples were analyzed in accordance with requirements in the ODCM and shown in Table 3, Radiological Environmental Monitoring Program - Waterborne.

Sediment samples from all locations were analyzed for gamma-emitting nuclides. All analyses met minimum detectable activities. No fission or activation products were detected.

8.4 Ingestion Pathway Sample Results 8.4.1 Milk Milk samples from milking animals were collected at 5 locations within 5 km having the highest dose potential, along with samples collected from a control location 15-30 km in the least prevalent wind direction. Samples were collected and analyzed monthly when cows were not on pasture and biweekly when cows were on pasture.

Samples were analyzed for low level iodine and gamma-emitting nuclides. Samples were also collected and analyzed quarterly from 5 additional milk locations.

Concentrations of naturally occurring potasssium-40 were consistent with those detected in previous years. No fission or activation products were found.

8.4.2 Fish and Invertebrates A total of 8 fish samples were collected in 2024. These samples were analyzed for gamma emitting radionuclides in edible portions, in accordance with requirements of the ODCM and summarized in Table 4, Radiological Environmental Monitoring Program - Ingestion. These samples are collected from the indicator and control areas as required by the ODCM (with a bottom feeder species and a predator species collected at each location). All non-natural gamma emitters were less than the minimal detectable activity. Concentrations of naturally occurring potassium-40 (K-40) were consistent with those detected in previous years.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 28 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 8.4.3 Food Products A total of 48 vegetation samples were analyzed in 2024 for gamma emitting radionuclides in accordance with requirements of the ODCM, as summarized in Table 4, Radiological Environmental Monitoring Program - Ingestion.

8.4.4 Leafy Vegetation In accordance with the ODCM and as described in Table 4, Radiological Environmental Monitoring Program - Ingestion, 48 broad leaf vegetation samples were collected from growing locations nearest site boundary in areas of highest predicted annual average ground level D/Q. Samples are collected and analyzed for gamma isotopic activity from the indicator and control locations monthly during growing season. It is common to detect Cs-137 in broadleaf samples at both indicator and control locations. Cs-137 can be attributed to offsite sources such as weapons testing, Chernobyl, and Fukushima events. All non-natural gamma emitters were less than the minimal detectable activity.

9.0 LAND USE CENSUS An annual land use census is required by the Offsite Dose Calculation Manual and is performed to ensure that changes in the use of areas at or beyond the site boundary are identified and modifications to REMP are made if required by changes in land use. The land use census satisfies the requirements of Section IV.B.3 of Appendix I to 10 CFR 50 [1]. NUREG-1302 Control 3.12.2 specifies that "a Land Use Census shall be conducted and shall identify within a distance of 8 km (5 mi.) the location in each of the 16 meteorological sectors of the nearest milk animal, the nearest residence and the nearest garden of greater than 50 m2 (500 ft2) producing broad leaf vegetation. Note, per NUREG-1302, broad leaf vegetation sampling of at least three different kinds of vegetation may be performed at the SITE BOUNDARY in each of two different direction sectors with the highest predicted D/Qs in lieu of the garden census.

A Land Use Census was conducted during the calendar year 2024, within the growing season, to identify changes in land use, receptor locations, and new exposure pathways. The results for the 2024 Land Use Census are listed in Table 8:

Land Use Census - Nearest Receptors within 5 miles. The nearest gardens in all other sectors reported in the 2024 report are the same as the previous years report.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 29 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 8, Land Use Census - Nearest Receptors within 5 miles Sector Direction Nearest Residence (Miles)

Nearest Garden(1)

(Miles)

Nearest Dairy Animal (Miles)

A N

2.34 2.69 2.69 B

NNE 2.10 2.09 2.05 C

NE 1.91 1.89 1.99 D

ENE 1.99 2.35 2.07*

E E

1.91 2.74 2.74 F

ESE 3.05 3.62 3.82 G

SE 2.04 2.04 3.62*

H SSE 0.74 0.74 Not Found in Sector J

S 1.05 1.05 Not Found in Sector K

SSW 1.15 1.11 2.20 L

SW 0.90 0.92 0.92*

M WSW 0.76 1.72 Not Found in Sector N

W 0.80 0.80 1.84 P

WNW 0.55 0.79 4.19 Q

NW 0.56 0.91 1.81 R

NNW 0.97 Not Found in Sector Not Found in Sector (1) Larger than 500 square feet (as can best be determined from a distance)

Denotes current REMP milk sample location Red Denotes the site/site information has been updated from the previous years Land Use Census 10.0 SAMPLE DEVIATIONS, ANOMALIES AND UNAVAILABILITY Sampling and analysis are performed for media types addressed in the Offsite Dose Calculation Manual. Sampling and analysis challenges may be experienced due to a multitude of reasons including environmental factors, loss of TLDs/OSLDs, contamination of samples, etc. To aid classification of sampling and analysis challenges experienced in 2024, the following three terms are used to describe the issues: Sample Anomalies, Sample Deviation, and Unavailable Samples.

Media that experienced downtime (i.e., air samplers or water samplers) during a surveillance period are classified a Sample Deviation. Sample Anomalies are defined as errors that were introduced to a sample once it arrived in the laboratory, errors that prevents the sample from being analyzed as it normally would or may have altered the outcome of the analysis (i.e., cross contamination, human error).

Annual Radiological Environmental Operating Report YEAR: 2024 Page 30 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Sample Unavailability is defined as sample collection with no available sample (i.e.,

food crop, TLD).

All required samples were collected and analyzed as scheduled except for the following:

Table 9, Sample Deviation Summary Sample Type and Analysis Location Collection Date or Period Reason for not conducting REMP sampling as required by ODCM Plans for preventing reoccurrence Air Particulate and Iodine Cartridge 1C 1/18/24 Moisture in the rotameter on the pump; calculated volume of 71.6 m3.

Air pump was replaced and sampler was returned to operation Air Particulate and Iodine Cartridge 1Z 5/30/24 GFI outlet tripped which caused sample location to have less than required run time hours. The QA collocated air sampler location (1A) was collected and analyzed for credit instead of the 1Z sample.

The GFI outlet was reset and pump was restarted with no further issues.

11.0 OTHER SUPPLEMENTAL INFORMATION 11.1 NEI 07-07 Onsite Radiological Groundwater Monitoring Program Peach Bottom Atomic Power Station has developed a Groundwater Protection Initiative (GPI) program in accordance with NEI 07-07, Industry Ground Water Protection Initiative - Final Guidance Document. The purpose of the GPI is to ensure timely detection and an effective response to situations involving inadvertent radiological releases to groundwater in order to prevent migration of licensed radioactive material off-site and to quantify impacts on decommissioning. It is important to note that samples and results taken in support of NEI 07-07 on-site groundwater monitoring program are separate from the Radiological Environmental Monitoring Program (REMP). See Attachment 5.

11.2 Independent Spent Fuel Storage Installation (ISFSI) Monitoring Program In 2023, an evaluation of the background data set for all dosimeters was completed to determine if any changes were required. It was determined the background for dosimeter 1R should be updated. Due to casks being on the ISFSI pad, the dose for this location is elevated and not suitable to be used for the background. Pre-operational dose studies did not use dosimeters that are comparable to OSLDs, therefore, the background of the surrounding dosimeter locations were reviewed, and an average of those backgrounds was

Annual Radiological Environmental Operating Report YEAR: 2024 Page 31 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station applied to the 1R calculations. Detectable facility-related dose at 1R was identified as expected following the change. No annual facility dose was detected at any surrounding dosimeters.

11.3 Corrections to Previous Reports N/A

Annual Radiological Environmental Operating Report YEAR: 2024 Page 32 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station 12.0 BIBLIOGRAPHY

[1] NCRP, "Report No. 160, Ionizing Radiation Exposure of the Population of the United States,"

National Council on Radiation Protection, Bethesda, 2009.

[2] "10 CFR 50, "Domestic Licensing of Production and Utilization Facilities"," US Nuclear Regulatory Commission, Washington, DC.

[3] "Regulatory Guide 4.1, "Radiological Environmental Monitoring for Nuclear Power Plants",

Revision 2," Nuclear Regulatory Commission, 2009.

[4] "NUREG-1301, Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Pressurized Water Reactors,.," Nuclear Regulatory Commission, April 1991.

[5] "NUREG-1302, Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Boiling Water Reactors,," Nuclear Regulatory Commission, April 1991.

[6] "Branch Technical Position, Revision 1," NRC000096, Submitted March 30, 2012, November 1979.

[7] "Japan Atomic Energy Agency," 06 November 2020. [Online]. Available:

https://www.jaea.go.jp/english/04/ntokai/houkan/houkan_02.html.

[8] "Regulatory Guide 4.15, Quality Assurance for Radiological Monitoring Programs (Inception through Normal Operations to License Termination) -- Effluent Streams and the Environment,"

Nuclear Regulatory Commission, July, 2007.

[9] "Regulatory Guide 4.13, Performance, Testing, and Procedural Specifications for Thermoluminescence Dosimetry: Environmental Applications, Revision 2," Nuclear Regulatory Commision, June, 2019.

[10] "NUREG/CR-2919, XOQDOQ Computer Program for the Meteorological Evaluation of Routine Effluent Releases at Nuclear Power Stations,," Nuclear Regulatory Commission, September, 1982.

[11] "Measurements of Radionuclides in the environment Sampling and Analysis of plutonium in soil,"

Nuclear Regulatory Commission, 1974.

[12] "Ionizing Radiation Exposure of the Population of the United States," Bethesda, MD, 2009.

[13] Nuclear Regulatory Commission, 30 June 2015. [Online]. Available: http://www.nrc.gov/reading-rm/basic-ref/students/animated-pwr.html. [Accessed October 2020].

[14] "ICRP Publication 60, ICRP Publication 60: 1990 Recommendations of the International Commission on Radiological Protection, 60, Annals of the ICRP Volume 21/1-3,," International Commission on Radiation Protection, October, 1991.

[15] "NRC Resource Page," [Online]. Available: http://www.nrc.gov/about-nrc/radiation.html. [Accessed 10 November 2020].

[16] "NUREG-0133, Preparation of Effluent Technical Specifications for Nuclear Power Plants,"

Nuclear Regulatory Commission, 1987.

[17] "Regulatory Guide 1.109, Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Demonstrating Compliance with 10 CFR Part 50, Appendix I,,"

Nuclear Regulatory Commission, Ocotober, 1977.

[18] [Online]. Available: http://hps.org/hpspublications/radiationfactsheets.html. [Accessed 2020].

[19] "NEI 07-07, Industry Ground Water Protection InitiativeFinal Guidance Document,," Nuclear Energy Institute, Washington, D.C..

Annual Radiological Environmental Operating Report YEAR: 2024 Page 33 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

[20] "ANSI 13.37, Environmental Dosimetry-Criteria for System Design and Implementation," Health Physics Society (HPS), May, 2019.

[21] "40 CFR Part 141, National Primary Drinking Water Regulations,," US Environmental Protection Agency, Washington, DC..

[22] Nuclear Regulatory Commission, 25 June 2015. [Online]. Available: http://www.nrc.gov/reading-rm/basic-ref/students/animated-bwr.html. [Accessed October 2020].

[23] "NEI 07-07, Industry Ground Water Protection InitiativeFinal Guidance Document, Rev. 1,"

Nuclear Energy Institute, Washington, D.C., 2019.

[24] Nuclear Regulatory Commission, 25 June 2015. [Online]. Available: http://www.nrc.gov/reading-rm/basic-ref/students/animated-bwr.html. [Accessed October 2020].

[25] [Online]. Available: http://hps.org/hpspublications/radiationfactsheets.html. [Accessed 2020].

[26] "Japan Atomic Energy Agency," 06 November 2020. [Online]. Available:

https://www.jaea.go.jp/english/04/ntokai/houkan/houkan_02.html.

[27] "NRC Resource Page," [Online]. Available: http://www.nrc.gov/about-nrc/radiation.html. [Accessed 10 November 2020].

[28] "NUREG-0133, Preparation of Effluent Technical Specifications for Nuclear Power Plants,"

Nuclear Regulatory Commission, 1987.

[29] Nuclear Regulatory Commission, 30 June 2015. [Online]. Available: http://www.nrc.gov/reading-rm/basic-ref/students/animated-pwr.html. [Accessed October 2020].

[30] "Regulatory Guide 4.13, Performance, Testing, and Procedural Specifications for Thermoluminescence Dosimetry: Environmental Applications, Revision 2," Nuclear Regulatory Commision, June, 2019.

[31] "Regulatory Guide 4.15, Quality Assurance for Radiological Monitoring Programs (Inception through Normal Operations to License Termination) -- Effluent Streams and the Environment,"

Nuclear Regulatory Commission, July, 2007.

[32] "10 CFR 50 - Domestic Licensing of Production and Utilization Facilities," US Nuclear Regulatory Commission, Washington, DC.

[33] "40 CFR 190 - Environmental Radiation Protection Standards for Nuclear Power Operation," US Environmental Protection Agency, Washington, DC.

[34] "NUREG-0324 - XOQDOQ, Program for the Meteorological Evaluation of Routine Effluent Releases at Nuclear Power Stations," Nuclear Regulatory Commission, September, 1977.

[35] "NCRP Report No. 160 - Ionizing Radiation Exposure of the Population of the United States,"

National Council on Radiation Protection and Measurements, Bethesda, MD, 2009.

[36] "Regulatory Guide 1.109 - Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Demonstrating Compliance with 10 CFR Part 50, Appendix I," Nuclear Regulatory Commission, Ocotober, 1977.

[37] "40 CFR 141 - National Primary Drinking Water Regulations," US Environmental Protection Agency, Washington, DC..

[38] "10 CFR 20 - Standards for Protection Against Radiation," US Nuclear Regulatory Commission, Washington, DC

[39] Preoperational Environs Radioactivity Survey Summary Report, March 1960 through January 1966. (September 1967)

[40] Interex Corporation, Peach Bottom Atomic Power Station Regional Environs Radiation Monitoring Program Preoperational Summary Report, Units 2 and 3, 5 February 1966 through 8 August 1973, June 1977, Natick, Massachusetts

Annual Radiological Environmental Operating Report YEAR: 2024 Page 34 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

[41] Radiation Management Corporation Publication, Peach Bottom Atomic Power Station Preoperational Radiological Monitoring Report for Unit 2 and 3, January 1974, Philadelphia, PA

[42] Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Boiling Water Reactors, Generic Letter 89-01, Supplement No. 1 (NUREG-1302), April 1991

[43] American National Standards Institute/Health Physis Society, (ANSI/HPS) N13.37-2014, "Environmental Dosimetry-Criteria for System Design and Implementation"

[44] Constellation Generation Solutions Sampling Procedures

a. CY-ES-214, Collection of RGPP Water Samples for Radiological Analysis

b. CY-ES-237, Air Iodine and Air Particulate Sample Collection for Radiological

c. CY-ES-239, EIS Collection Exchange of Field Dosimeters for Radiological Analysis

d. CY-ES-241, Vegetation Sample Collection for Radiological Analysis

e. CY-ES-242, Soil and Sediment Sample Collection for Radiological Analysis

f. CY-ES-247, Precipitation Sampling and Collection for Radiological Analysis

[45] Constellation Generation Solutions Analytical Procedures

a. CY-ES-204, Sample Preparation for Gamma Analysis

b. CY-ES-205, Operation of HPGE Detectors with the Genie PC Counting System

c. CY-ES-206, Operation of the Tennelec S5E Proportional Counter

d. CY-ES-246, Sample Preparation for Gross Beta Analysis

[46] Peach Bottom Atomic Power Station 2024 Land use Survey

[47] CY-AA-170-1000, Radiological Environmental Monitoring Program (REMP) and Meteorological Program Implementation.

[48] Teledyne Browne Engineering, (TBE) 2018 Analysis Procedures Current Revisions

a. TBE-2001 Alpha Isotopic and Pu-241

b. TBE-2006 Iron-55 Activity in Various Matrices

c. TBE-2007 Gamma Emitting Radioisotope Analysis

d. TBE-2008 Gross Alpha and/or Gross Beta Activity in Various Matrices

d. TBE-2011 Tritium Analysis in Drinking Water by Liquid Scintillation

e. TBE-2013 Radionickel Activity in Various Matrices

f. TBE-2019 Radiostrontium Analysis by Ion Exchange

[49] GEL Laboratory Procedures

a. GL-RAD-A-002 Tritium

b. GL-RAD-A-022 Ni-63

c. GL-RAD-A-004 Sr89/90, Liquid

d. GL-RAD-A-040 Fe-55

[50] Normandeau Associates, Inc. (NAI) Sampling Procedures Current Revisions

a. Procedure No. ER2 Collection of Silt Samples for Radiological Analysis

b. Procedure No. ER3 Collection of Fish Samples for Radiological Analysis

[51] Landauer Incorporated, Analysis procedure proprietary, Current Revision

[52] Teledyne Browne Engineering Environmental Services, 4th Quarter 2024 Quality Assurance Report, January - December 2024

[53] GEL 2024 Annual Environmental Quality Assurance Report for the Radiological Environmental Monitoring Program (REMP)

Annual Radiological Environmental Operating Report YEAR: 2024 Page 35 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

, Data Table Summary Medium or Pathway Sampled (Units)

Type, Total Number of Analyses performed (e.g., I-131, 400)

Lower Limit of Detection (LLD)

Indicator Mean5; (f6).

Range1 Location with Highest Annual Mean Control Mean1 (f2).

Range1 Number of Nonroutine Reported Measurements Name Distance and Direction Mean1 (f2)

Range1 Air Particulates (pCi/m3)

Beta, 265 (0.01) 2.84E-02 (1.00E 5.99E-02)

(212/212) 1Z 2.90E-02 (1.27E 5.71E-02)

(53/53) 2.49E-02 (9.20E 4.15E-02)

(53/53) 0 Direct Radiation (mrem/qtr.)

Gamma Dose, 384 N/A 20.2 (8.8-31.9)

(376/376) 1R ISFSI Pad 29.4 (25.9-31.9)

(8/8) 14.4 (11.9-16.5)

(8/8) 0 Drinking Water (pCi/L)

Gross Beta, 36 4

2.03 (1.19-2.63)

(24/24) 13B Chester Water Authority 2.15 (1.33-2.63)

(12/12) 1.80 (1.19-2.65)

(12/12) 0 1,5 Mean and range are based on detectable measurements only.

2,6 Fraction of detectable measurements at specified locations is indicated in parentheses.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 36 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

, Complete Data Table for All Analysis Results Obtained In 2024 Table 10, Monthly Drinking Water Results Monthly Radionuclides in Drinking Water (pCi/L)

Location 13B 4L 6I (Control)

Date Gamma Emitters Gross Beta Activity Uncertainty (2-)

Gamma Emitters Gross Beta Activity Uncertainty (2-)

1/29/2024 1.33E+00 7.56E-01 1/31/2024 1.47E+00 7.67E-01 1.66E+00 7.80E-01 2/26/2024 1.81E+00 8.05E-01 2/28/2024 1.70E+00 7.96E-01 1.50E+00 7.83E-01 3/26/2024 2.06E+00 7.71E-01 3/27/2024 1.19E+00 7.05E-01 1.42E+00 7.22E-01 4/29/2024 2.06E+00 7.54E-01 5/01/2024 1.47E+00 7.10E-01 1.19E+00 6.87E-01 5/28/2024 2.10E+00 7.61E-01 5/30/2024 1.45E+00 7.11E-01 1.28E+00 6.96E-01 6/24/2024 2.63E+00 8.42E-01 6/27/2024 1.98E+00 7.96E-01 1.90E+00 7.90E-01 7/29/2024 2.42E+00 7.93E-01 8/01/2024 2.42E+00 7.92E-01 2.56E+00 8.02E-01 8/26/2024 2.06E+00 7.89E-01 8/29/2024 2.15E+00 7.96E-01 1.37E+00 7.38E-01 9/30/2024 2.26E+00 8.08E-01 10/03/2024 2.26E+00 8.07E-01 1.70E+00 7.69E-01 10/28/2024 2.59E+00 8.33E-01 10/31/2024 2.14E+00 8.01E-01 2.65E+00 8.35E-01 12/2/2024 2.46E+00 8.40E-01 12/4/2024 2.26E+00 8.28E-01 2.20E+00 8.23E-01 12/31/2024 2.04E+00 7.59E-01 01/02/2025 1.95E+00 7.52E-01 1.84E+00 7.42E-01

Annual Radiological Environmental Operating Report YEAR: 2024 Page 37 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 11, Monthly Surface Water Results Monthly Radionuclides in Surface Water (pCi/L)

Location 1LL (Control) 1MM Date Gamma Emitters Gross Beta Activity Uncertainty Gamma Emitters Gross Beta Activity Uncertainty 1/31/2024 ND ND ND ND 2/28/2024 ND ND ND ND 3/27/2024 ND ND ND ND 5/1/2024 ND ND ND ND 5/29/2024 ND ND ND ND 6/26/2024 ND ND ND ND 7/31/2024 ND ND ND ND 8/28/2024 ND ND ND ND 10/2/2024 ND ND ND ND 10/30/2024 ND ND ND ND 12/4/2024 ND ND ND ND 1/1/2025 ND ND ND ND

All Non Natural Radionuclides <MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 38 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 12, Monthly Vegetation Results Radionuclides in Vegetation (pCi/kg wet)

Date Sample Code Sample Type Gamma Emitters 6/18/2024 1C Kale 6/18/2024 Horseradish 6/18/2024 Collards 7/16/2024 Kale 7/16/2024 Cabbage 7/16/2024 Collards 8/14/2024 Kale 8/14/2024 Cabbage 8/14/2024 Collards 9/10/2024 Corn Leaves 9/10/2024 Squash 9/10/2024 Collards 6/18/2024 2Q Cabbage 6/18/2024 Broccoli 6/18/2024 Cauliflower 7/16/2024 Cabbage 7/16/2024 Broccoli 7/16/2024 Squash 8/14/2024 Cabbage 8/14/2024 Broccoli 8/14/2024 Squash Leaves 9/10/2024 Cabbage 9/10/2024 Broccoli

All Non Natural Radionuclides <MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 39 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 12, Monthly Vegetation Results Radionuclides in Vegetation (pCi/kg wet)

Date Sample Code Sample Type Gamma Emitters 6/18/2024 3Q Zucchini 6/18/2024 Kale 6/18/2024 Lettuce 7/16/2024 Broccoli 7/16/2024 Kale 7/16/2024 Cabbage 8/14/2024 Cauliflower 8/14/2024 Cabbage 8/14/2024 Squash Leaves 9/10/2024 Cabbage 9/10/2024 Beets 9/10/2024 Sunflower Leaves 6/18/2024 55 (Control)

Cabbage 6/18/2024 Kale 6/18/2024 Swiss Chard 7/16/2024 Cabbage 7/16/2024 Kale 7/16/2024 Swiss Chard 8/14/2024 Cabbage 8/14/2024 Kale 8/14/2024 Swiss Chard 9/10/2024 Zucchini 9/10/2024 Corn Leaves 9/10/2024 Swiss Chard

All Non Natural Radionuclides <MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 40 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 13, Monthly Milk Results Monthly Gamma Emitters in Milk (pCi/L)

Date M-11A M-7D M-15B M-4C M-1C M-13F (Control) 1/17/2024 2/13/2024 3/11/2024 3/12/2024 4/3/2024 4/17/2024 4/30/2024 5/14/2024 5/29/2024 6/11/2024 6/25/2024 7/9/2024 7/23/2024 8/6/2024 8/20/2024 9/4/2024 9/17/2024 10/1/2024 10/16/2024 10/30/2024 11/12/2024 11/26/2024 12/10/2024

All Non Natural Radionuclides <MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 41 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 14, Weekly Airborne I-131 Results Concentration of Iodine-131 in Filtered Air (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control) 1/2/2024 1/4/2024 1/8/2024 1/11/2024 1/16/2024 1/18/2024 1/22/2024 1/25/2024 1/29/2024 1/31/2024 2/6/2024 2/7/2024 2/12/2024 2/15/2024 2/19/2024 2/22/2024 2/26/2024 2/28/2024 3/4/2024 3/7/2024 3/11/2024 3/14/2024 3/18/2024 3/20/2024

Annual Radiological Environmental Operating Report YEAR: 2024 Page 42 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 14, Weekly Airborne I-131 Results Concentration of Iodine-131 in Filtered Air (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control) 3/25/2024 3/27/2024 4/1/2024 4/4/2024 4/8/2024 4/10/2024 4/15/2024 4/18/2024 4/22/2024 4/25/2024 4/29/2024 5/1/2024 5/6/2024 5/9/2024 5/13/2024 5/16/2024 5/20/2024 5/23/2024 5/28/2024 5/30/2024

1 6/3/2024 6/6/2024 6/10/2024 6/13/2024 6/17/2024 6/20/2024 6/25/2024 6/27/2024

Annual Radiological Environmental Operating Report YEAR: 2024 Page 43 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 14, Weekly Airborne I-131 Results Concentration of Iodine-131 in Filtered Air (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control) 7/1/2024 7/3/2024 7/8/2024 7/11/2024 7/15/2024 7/18/2024 7/22/2024 7/25/2024 7/29/2024 8/1/2024 8/5/2024 8/8/2024 8/12/2024 8/15/2024 8/19/2024 8/22/2024 8/26/2024 8/29/2024 9/3/2024 9/5/2024 9/9/2024 9/12/2024 9/16/2024 9/19/2024 9/23/2024 9/26/2024 9/30/2024 10/3/2024 10/7/2024 10/10/2024

Annual Radiological Environmental Operating Report YEAR: 2024 Page 44 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 14, Weekly Airborne I-131 Results Concentration of Iodine-131 in Filtered Air (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control) 10/14/2024 10/16/2024 10/21/2024 10/24/2024 10/29/2024 10/31/2024 11/4/2024 11/7/2024 11/11/2024 11/14/2024 11/18/2024 11/20/2024 11/25/2024 11/26/2024 12/2/2024 12/4/2024 12/9/2024 12/12/2024 12/16/2024 12/19/2024 12/23/2024 12/26/2024 12/30/2024 1/02/2025 1 Due to air sampler failure, sample of record for this location was from collocated sample, 1A. See Table 9.

All Non Natural Radionuclides <MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 45 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 15, Weekly Airborne Gross Beta Results Gross Beta Activity in Air Particulates (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control)

Gross Beta Activity (2-)

1/2/2024 2.30E-02 2.54E-03 1/4/2024 3.12E-02 2.54E-03 3.17E-02 2.52E-03 3.12E-02 2.53E-03 3.09E-02 2.50E-03 1/8/2024 1.97E-02 2.35E-03 1/11/2024 1.91E-02 2.25E-03 1.91E-02 2.28E-03 2.04E-02 2.29E-03 1.87E-02 2.27E-03 1/16/2024 3.11E-02 2.31E-03 1/18/2024 4.13E-02 2.86E-03 3.08E-02 7.05E-03 4.23E-02 2.89E-03 3.74E-02 2.75E-03 1/22/2024 3.13E-02 2.91E-03 1/25/2024 3.20E-02 2.63E-03 3.43E-02 2.54E-03 3.56E-02 2.74E-03 3.49E-02 2.72E-03 1/29/2024 1.80E-02 2.01E-03 1/31/2024 1.00E-02 2.15E-03 1.24E-02 2.25E-03 1.34E-02 2.29E-03 1.25E-02 2.26E-03 2/6/2024 2.18E-02 2.19E-03 2/7/2024 2.49E-02 2.28E-03 2.60E-02 2.19E-03 2.85E-02 2.40E-03 2.57E-02 2.31E-03 2/12/2024 2.40E-02 2.61E-03 2/15/2024 3.01E-02 2.32E-03 3.32E-02 2.40E-03 3.36E-02 2.42E-03 2.87E-02 2.27E-03 2/19/2024 2.56E-02 2.32E-03 2/22/2024 2.78E-02 2.55E-03 2.60E-02 2.49E-03 2.59E-02 2.49E-03 2.61E-02 2.50E-03 2/26/2024 2.39E-02 2.25E-03 2/28/2024 3.24E-02 2.75E-03 3.64E-02 2.87E-03 3.29E-02 2.76E-03 3.47E-02 2.82E-03 3/4/2024 2.41E-02 2.30E-03 3/7/2024 1.55E-02 1.81E-03 1.50E-02 1.67E-03 1.84E-02 2.04E-03 1.54E-02 1.80E-03 3/11/2024 9.20E-03 1.62E-03 3/14/2024 2.36E-02 2.30E-03 2.45E-02 2.34E-03 2.73E-02 2.43E-03 2.61E-02 2.39E-03 3/18/2024 3.21E-02 2.51E-03 3/20/2024 2.51E-02 2.65E-03 2.59E-02 2.78E-03 2.73E-02 2.72E-03 2.59E-02 2.76E-03 3/25/2024 1.63E-02 2.06E-03

Annual Radiological Environmental Operating Report YEAR: 2024 Page 46 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 15, Weekly Airborne Gross Beta Results Gross Beta Activity in Air Particulates (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control)

Gross Beta Activity (2-)

3/27/2024 1.75E-02 2.08E-03 1.95E-02 2.16E-03 2.17E-02 2.23E-03 2.26E-02 2.26E-03 4/1/2024 2.09E-02 2.19E-03 4/4/2024 2.01E-02 2.13E-03 2.10E-02 2.01E-03 2.26E-02 2.14E-03 2.25E-02 2.06E-03 4/8/2024 9.62E-03 1.69E-03 4/10/2024 1.60E-02 2.42E-03 1.31E-02 2.19E-03 1.58E-02 2.23E-03 1.27E-02 2.02E-03 4/15/2024 2.18E-02 2.16E-03 4/18/2024 2.74E-02 2.31E-03 2.89E-02 2.24E-03 3.00E-02 2.31E-03 3.10E-02 2.29E-03 4/22/2024 1.82E-02 2.07E-03 4/25/2024 1.80E-02 2.07E-03 2.16E-02 2.19E-03 2.08E-02 2.16E-03 2.41E-02 2.28E-03 4/29/2024 2.36E-02 2.22E-03 5/1/2024 2.97E-02 2.64E-03 3.35E-02 2.79E-03 3.07E-02 2.68E-03 3.00E-02 2.52E-03 5/6/2024 2.09E-02 2.17E-03 5/9/2024 1.86E-02 1.95E-03 2.09E-02 2.01E-03 2.08E-02 2.02E-03 2.16E-02 2.03E-03 5/13/2024 1.66E-02 2.03E-03 5/16/2024 1.46E-02 1.95E-03 1.66E-02 2.00E-03 1.43E-02 1.91E-03 1.74E-02 2.03E-03 5/20/2024 1.79E-02 2.03E-03 5/23/2024 1.26E-02 1.94E-03 1.65E-02 2.12E-03 1.65E-02 2.11E-03 1.64E-02 1.98E-03 5/28/2024 2.71E-02 2.23E-03 5/30/2024 2.57E-02 2.31E-03 2.98E-02 2.44E-03 2.52E-02 1 2.22E-03 1 2.96E-02 2.44E-03 6/3/2024 2.35E-02 2.43E-03 6/6/2024 3.13E-02 2.70E-03 3.03E-02 2.48E-03 3.09E-02 2.52E-03 2.94E-02 2.31E-03 6/10/2024 2.42E-02 2.34E-03 6/13/2024 1.58E-02 1.97E-03 1.83E-02 2.07E-03 1.41E-02 1.91E-03 1.74E-02 2.04E-03 6/17/2024 2.15E-02 2.53E-03 6/20/2024 2.52E-02 2.30E-03 2.99E-02 2.46E-03 2.80E-02 2.39E-03 2.90E-02 2.29E-03 6/25/2024 2.98E-02 2.33E-03 6/27/2024 2.74E-02 2.54E-03 3.25E-02 2.52E-03 3.41E-02 2.66E-03 3.42E-02 2.57E-03

Annual Radiological Environmental Operating Report YEAR: 2024 Page 47 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 15, Weekly Airborne Gross Beta Results Gross Beta Activity in Air Particulates (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control)

Gross Beta Activity (2-)

7/1/2024 2.07E-02 2.47E-03 7/3/2024 1.47E-02 2.27E-03 1.50E-02 2.28E-03 1.68E-02 2.35E-03 1.71E-02 2.37E-03 7/8/2024 2.50E-02 2.34E-03 7/11/2024 3.29E-02 2.50E-03 3.39E-02 2.38E-03 3.65E-02 2.61E-03 3.49E-02 2.40E-03 7/15/2024 2.61E-02 2.34E-03 7/18/2024 3.00E-02 2.65E-03 2.92E-02 2.47E-03 3.05E-02 2.50E-03 3.14E-02 2.40E-03 7/22/2024 3.06E-02 2.74E-03 7/25/2024 3.04E-02 2.51E-03 3.04E-02 2.49E-03 2.75E-02 2.41E-03 3.11E-02 2.36E-03 7/29/2024 2.57E-02 2.37E-03 8/1/2024 3.40E-02 2.63E-03 3.10E-02 2.54E-03 2.78E-02 2.44E-03 3.59E-02 2.68E-03 8/5/2024 3.35E-02 2.61E-03 8/8/2024 3.17E-02 2.55E-03 3.36E-02 2.61E-03 3.11E-02 2.53E-03 3.29E-02 2.59E-03 8/12/2024 2.49E-02 2.32E-03 8/15/2024 2.48E-02 2.34E-03 2.29E-02 2.28E-03 2.76E-02 2.60E-03 2.52E-02 2.38E-03 8/19/2024 2.88E-02 2.49E-03 8/22/2024 2.48E-02 2.36E-03 2.42E-02 2.35E-03 2.58E-02 2.40E-03 2.42E-02 2.33E-03 8/26/2024 2.42E-02 2.35E-03 8/29/2024 5.33E-02 3.10E-03 4.90E-02 3.01E-03 5.71E-02 3.20E-03 5.99E-02 3.29E-03 9/3/2024 3.65E-02 2.49E-03 9/5/2024 3.17E-02 2.63E-03 3.16E-02 2.61E-03 4.02E-02 2.86E-03 5.28E-02 3.16E-03 9/9/2024 1.85E-02 2.45E-03 9/12/2024 3.14E-02 2.58E-03 3.04E-02 2.54E-03 3.17E-02 2.58E-03 3.23E-02 2.61E-03 9/16/2024 4.15E-02 2.81E-03 9/19/2024 3.79E-02 2.75E-03 3.65E-02 2.71E-03 4.22E-02 2.86E-03 4.08E-02 2.82E-03 9/23/2024 3.54E-02 2.66E-03 9/26/2024 3.20E-02 2.53E-03 2.64E-02 2.35E-03 3.14E-02 2.51E-03 3.14E-02 2.51E-03 9/30/2024 1.02E-02 1.81E-03 10/3/2024 1.22E-02 1.89E-03 1.32E-02 1.94E-03 1.27E-02 1.91E-03 1.03E-02 1.82E-03 10/7/2024 2.51E-02 2.32E-03

Annual Radiological Environmental Operating Report YEAR: 2024 Page 48 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 15, Weekly Airborne Gross Beta Results Gross Beta Activity in Air Particulates (pCi/m3)

GROUP I GROUP II GROUP III Date 1B 1C 1Z 3A 5H2 (Control)

Gross Beta Activity (2-)

10/10/2024 3.75E-02 2.69E-03 3.44E-02 2.59E-03 4.26E-02 2.82E-03 4.16E-02 2.80E-03 10/14/2024 3.30E-02 2.51E-03 10/16/2024 4.01E-02 2.97E-03 3.87E-02 2.97E-03 3.35E-02 2.63E-03 3.64E-02 2.89E-03 10/21/2024 2.31E-02 2.26E-03 10/24/2024 4.75E-02 2.77E-03 4.26E-02 2.62E-03 4.28E-02 2.50E-03 4.46E-02 2.68E-03 10/29/2024 3.92E-02 2.55E-03 10/31/2024 4.25E-02 2.85E-03 3.54E-02 2.65E-03 3.55E-02 2.50E-03 3.77E-02 2.72E-03 11/4/2024 3.10E-02 2.73E-03 11/7/2024 2.66E-02 2.20E-03 2.99E-02 2.45E-03 3.33E-02 2.41E-03 2.64E-02 2.33E-03 11/11/2024 2.48E-02 2.33E-03 11/14/2024 2.63E-02 2.40E-03 2.59E-02 2.37E-03 2.98E-02 2.49E-03 2.66E-02 2.40E-03 11/18/2024 2.18E-02 2.27E-03 11/20/2024 3.59E-02 2.92E-03 3.19E-02 2.82E-03 3.67E-02 2.96E-03 3.36E-02 2.86E-03 11/25/2024 3.21E-02 2.45E-03 11/26/2024 2.39E-02 2.50E-03 2.48E-02 2.51E-03 2.37E-02 2.47E-03 2.50E-02 2.52E-03 12/2/2024 3.38E-02 2.65E-03 12/4/2024 3.61E-02 2.44E-03 3.64E-02 2.46E-03 3.52E-02 2.42E-03 3.65E-02 2.46E-03 12/9/2024 2.92E-02 2.47E-03 12/12/2024 3.82E-02 2.56E-03 3.74E-02 2.55E-03 3.97E-02 2.61E-03 3.43E-02 2.46E-03 12/16/2024 3.08E-02 2.47E-03 12/19/2024 2.58E-02 2.33E-03 2.74E-02 2.37E-03 2.61E-02 2.32E-03 2.56E-02 2.31E-03 12/23/2024 1.67E-02 2.05E-03 12/26/2024 2.92E-02 2.44E-03 3.26E-02 2.56E-03 3.07E-02 2.50E-03 2.87E-02 2.44E-03 12/30/2024 2.30E-02 2.24E-03 1/02/2025 1.97E-02 2.12E-03 2.42E-02 2.27E-03 2.40E-02 2.26E-03 2.21E-02 2.19E-03 1 Due to air sampler failure, sample of record for this location was from collocated sample, 1A. See Table 9.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 49 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 16, Quarterly Isotopic Data for Air Filters, Water, Milk and Fish Location Nuclide Q1 Q2 Q3 Q4 Quarterly Air Filter Composite for Gamma Emitters (pCi/m3) 5H2 (Control)

Cs134, Cs137

<MDAs

<MDAs 3A Cs134, Cs137

<MDAs

<MDAs 1Z Cs134, Cs137

<MDAs

<MDAs 1B Cs134, Cs137

<MDAs

<MDAs 1C Cs134, Cs137

<MDAs

<MDAs Quarterly Tritium in Water (pCi/L) 1LL H-3

<MDA

<MDA 1MM H-3

<MDA

<MDA 6I H-3

<MDA

<MDA 4L H-3

<MDA

<MDA 13B H-3

<MDA

<MDA Quarterly Milk Samples for Gamma Emitters (pCi/m3)

M-3D Gamma Emitters

<MDAs

<MDAs M-1F Gamma Emitters

<MDAs

<MDAs M-3B Gamma Emitters

<MDAs

<MDAs M-9G Gamma Emitters

<MDAs

<MDAs M-15G Gamma Emitters

<MDAs

Annual Radiological Environmental Operating Report YEAR: 2024 Page 50 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 17, Gamma Isotopic Results for Fish Radionuclides in Fish (pCi/kg wet)

Sample Date Sample Code Sample Type Gamma Emitters 6/6/2024 4

Bottom Feeder 6/6/2024 Predator Fish 10/8/2024 Bottom Feeder 10/8/2024 Predator Fish 6/7/2024 6

Bottom Feeder 6/7/2024 Predator Fish 10/21/2024 Predator Fish 10/21/2024 Bottom Feeder

All Non-Natural Gamma Emitters <MDA Table 18, Gamma Isotopic Results for Sediment Radionuclides in Sediment (pCi/kg dry)

Sample Date Sample Code Gamma Emitters 5/22/2024 4J 11/5/2024 4J 5/22/2024 4T 11/5/2024 4T 5/22/2024 6F 11/5/2024 6F

All Non-Natural Gamma Emitters <MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 51 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

, Cross Check Intercomparison Program Participation in cross check intercomparison studies is mandatory for laboratories performing analyses of REMP samples satisfying the requirements in the Offsite Site Dose Calculation Manual. Intercomparison studies provide a consistent and effective means to evaluate the accuracy and precision of analyses performed by a laboratory.

Study results should fall within specified control limits and results that fall outside the control limits are investigated and corrected.

Constellation Generation Solutions Laboratory participated in the following proficiency testing studies provided by Environmental Resource Associates (ERA) and Eckert Ziegler Analytics (EZA) in 2024. The Laboratorys intercomparison program results for 2024 are summarized below. is a summary of Constellation Generation Solutions (CGS) laboratorys quality assurance program. It consists of Table 19 which is a compilation of the results of the CGS laboratorys participation in an interlaboratory comparison program with Environmental Resource Associates (ERA) located in Arvada, Colorado and Eckert and Ziegler Analytics, Inc. (EZA) located in Atlanta, Georgia.

It also includes a compilation of the results of the Constellation Generation Solutions (CGS) Laboratorys participation in a split sample program with Teledyne Brown Engineering located in Knoxville, Tennessee.

The CGS laboratory's intercomparison results are in full agreement when they were evaluated using designated acceptance ranges and the Resolution Test Criteria in accordance with the Constellation Radiochemistry Quality Control procedure, except as noted in the Pass/Fail column and described below. The CGS laboratory's results are provided with their analytical uncertainties of 2 sigma. When evaluating with the Resolution Test a one sigma uncertainty is used to determine Pass or Fail and noted accordingly. Co-located air samplers provide the opportunity to perform interlaboratory comparisons of beta particulate and radioiodine filters that due to the nature of the sample precludes them from splitting for analysis. Results of 1Z analyzed by CGS and 1A analyzed by TBE for beta particulates are provided at the end of this table for review and are generally in good agreement. The radioiodine samples collected alongside the beta particulate filters were analyzed and all were below MDA so there are no results to compare for that parameter.

All CGS results reported passed their respective acceptance ranges and Resolution Test Criteria with the following two exceptions for the interlaboratory crosschecks:

Annual Radiological Environmental Operating Report YEAR: 2024 Page 52 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station RAD-137 I-131 water study on 04/08/2024 on Detector 6 (D6) failed high at 29.7 pCi/L for a true value of 25.1 pCi/L with an acceptance range of 21.7 - 28.5 pCi/L. This was a new detector, and the study had very low area counts. Of the three runs, the other two values would have passed.

Results on all other detectors were successful. Further review of the data indicated all the Ba-133 results in the other RAD-137 water study were in acceptable range. In that study, Ba-133 is meant to approximate I-131 results as it has an energy very close to I-131 in the spectrum. The detector is new in the lab and there is an ongoing review of its performance to identify the optimal operating range and any inherent bias.

E14044 Filter study on 12/05/24 failed low for Cs-134 on D6 reporting 91.3 +/- 3.25 pCi for a true value of 116 pCi. This study also had unusually low area counts in this range of the spectrum. The result did pass the acceptance range of 81.2 - 150.8 pCi, however due to the extremely low activity level, count times were extended significantly to capture other isotopes with lower yields resulting in very low uncertainties for higher yield isotopes. In the case of Cs-134 the uncertainty was less than 5% and at the level of recovery observed, the result failed the resolution test. Routine analysis is normally performed to achieve 15%

+/- 5 %. Review of all other studies performed on this detector showed successful performance for Cs-134 and all other isotopes. The evaluation of detector performance is ongoing to identify inherent bias or variability at low count rates as is observed in environmental samples.

The vendor laboratories used by CGS for subcontracting and interlaboratory comparison samples, GEL Laboratories and Teledyne Brown Engineering (TBE), also participate in the ERA and EZA interlaboratory comparison program. A presentation of their full data report is provided in their Annual Environmental Quality Assurance Program Reports, [52,53]. In summary GEL and TBE reported results met vendor and laboratory acceptance ranges with the following exceptions described here.

For TBE, the following three studies reported data that did not meet the specified acceptance criteria and were addressed through the TBE Corrective Action Program. Investigations of the failures are described as follows:

TBE Crosschecks failed high for MRAD-40 Gross Beta at 42.1 pCi/Filter. The true value was 22.2 and the acceptable range was 13.5-33.5 pCi/Filter. All QC associated with the original sample was acceptable and no anomalies were found. This sample was used as the WG duplicate with a result of 42.5 pCi.

Both were counted on the same detector. Upon comparison to historical sample data, the alpha activity of this ERA submitted sample was the highest assigned result, and the beta activity was the lowest. Therefore, the alpha-to-beta crosstalk was more significant than normal, causing the beta activity to report falsely high data. The counting room laboratory staff will adjust the alpha-to-beta crosstalk via correction calculation measures when high alpha are observed.

Subsequent study MRAD-41 for Gross Beta filter returned acceptable results.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 53 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station RAD-137 Gross Alpha in water failed low at 35.2 pCi/L. The true value was 52.6 pCi/L and the acceptable range was 39.6 - 65.6 pCi/L. A QuiKResponse repeat study was analyzed and failed high at 40.3 pCi/L and the acceptable range was 21.5 - 38.5 pCi/L. Investigation showed higher than usual solids in the ERA study, out of the usual range of client samples received by the lab. Also, a different attenuation curve, Th-230, was used for the crosscheck than had been used historically. This curve was less representative of client samples. The lab review of data also showed that a replicate run of the sample would have passed but the lab chose the wrong replicate to report. The lab has gone to a lower volume of sample and resumed using the Am-241 attenuation curve which more closely mirrors client samples and subsequent crosschecks are reporting acceptable.

Quarter 1-2024 gamma results for Co-60 (air filter) and Ce-141 (soil) both failed high. The reported result for the filter Co-60 was 168+/- 12.7 and the known value was 126+/-2.1; the reported results for the soil Ce-141 was 0.106 and the known value was 0.0714+/-0.0013 pCi/g. The root cause investigation showed successful results for the filter on another detector. All QC associated with this sample was acceptable.

The soil was recounted on another detector and Ce-141 result of 0.085 was acceptable and generally the same for other geometries. All QC associated with this sample was acceptable. No effective corrective action can be taken at this time. Historically, the Filter Co-60 and soil Ce-141 results have been well within TBE QC acceptance ranges. TBE has successfully passed cross-check results, and it appears that these two results are anomalous. If there is a recurrence, a root cause investigation will be done promptly.

For the GEL Laboratory, the following six studies reported data that did not meet the specified acceptance criteria and were addressed through GELs internal nonconformance system. A summary is found below:

RAD-136 water Sr-90 failed high, while I-131 failed low.

Strontium-90: The Group Leader has reviewed the method to identify the bias.

The method LCS trend was reviewed, and no anomalies were identified. The calibration used for the analysis was compared to the new calibration performed recently and the original reported data was processed with both calibrations for comparison. Data still maintained a high bias but was within the limits of the study. A sample of known Strontium concentration was analyzed, and the results were processed using the new calibration. The result was within the mid-range of the acceptance limits. Instrument run logs were reviewed and there was no indication of possible bias from a previously counted sample.

Iodine-131: The laboratory has reviewed the data and found no errors. All batch QC samples, including a duplicate, met acceptance criteria. The carrier yields were found to be slightly higher than typically seen in this method, possibly contributing to the low bias in the result. The laboratory will continue to investigate all steps of the analytical process.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 54 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station RAD-137 water Sr-90 and I-131 studies both failed low.

Strontium-90: The unacceptable result was analyzed by a modified method of 905.0 and recovered 83% of the known value which is acceptable for the laboratorys LCS. The PT sample was also analyzed by EPA DW method 905.0 and achieved an acceptable result recovering 94% of the assigned value. The RPD between the methods was 12%. The laboratory is evaluating calibration, yield determination, techniques, reagents, carriers, and each step of the process for areas of improvement.

Iodine-131: The laboratory has reviewed the data and no errors were noted. All batch QC samples, including an in-batch duplicate, met acceptance criteria. It was noted that the carrier yields were found to be slightly higher than are typically seen in this method including the reference sample used to calculate the LCS, potentially contributing to the low bias in the result.

RAD-138 Sr-90 and I-131 on water failed low.

Strontium-90: The laboratory conducted an in-depth review of all available data and did not identify any specific errors or anomalies that could explain the performance evaluation failure. The instrument calibrations were reviewed for possible significant areas of variance when compared to previous calibrations and none were noted. The quality department conducted direct observations of the analytical processes noting minor areas of improvement during precipitations and column separations. A definitive root cause was not isolated during the investigation.

Iodine-131: The laboratory has reviewed the data and found no errors. All batch QC samples, including an in-batch duplicate, met the acceptance criteria. As part of the investigation, the quality department observed the preparation process. During the review, it was identified that a reagent may have been improperly diluted, potentially contributing to the low bias observed in the results.

This procedural discrepancy has been noted as a probable cause requiring corrective action.

The laboratory has since successfully completed a single-blind spiked sample, achieving results within the acceptance criteria for both Sr-90 and I-131.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 55 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 19, CGS Cross Check Intercomparison Results Study Date Study ID Units Radionuclide Reported Value Assigned Value Acceptance Performance Evaluation Lower Limit Upper Limit 3/14/2024 E14036 Milk pCi/L I-131 96.7 90.8 63.6 118 Pass pCi/L Cs-134 182 198 139 257 Pass pCi/L Cs-137 181 171 120 222 Pass pCi/L Ce-141 88.1 85 59.5 111 Pass pCi/L Cr-51 281 230 161 299 Pass pCi/L Mn-54 187 183 128 238 Pass pCi/L Fe-59 93.6 86.5 60.6 112 Pass pCi/L Co-60 152 158 111 205 Pass pCi/L Zn-65 161 176 123 229 Pass 3/14/2024 E14037 Water pCi/L Beta Cs-137 238 231 162 300 Pass 3/14/2024 E14038 Charcoal pCi I-131 75.9 90.2 63.1 117 Pass 3/14/2024 E14038 Charcoal pCi I-131 79.0 90.2 63.1 117 Pass 3/14/2024 E14038 Charcoal pCi I-131 77.1 90.2 63.1 117 Pass 3/14/2024 E14038 Charcoal pCi I-131 77.3 90.2 63.1 117 Pass 4/8/2024 RAD-137 Water pCi/L I-131 27.1 25.1 21.7 28.5 Pass 4/8/2024 RAD-137 Water pCi/L I-131 25.1 25.1 21.7 28.5 Pass 4/8/2024 RAD-137 Water pCi/L I-131 27.5 25.1 21.7 28.5 Pass 4/8/2024 RAD-137 Water pCi/L I-131 29.7 25.1 21.7 28.5 Fail 1 4/8/2024 RAD-137 Water pCi/L Beta Cs-137 36.6 46.5 33.9 59.1 Pass 4/8/2024 RAD-137 Water pCi/L Cs-134 55.9 57.8 42.8 72.8 Pass pCi/L Cs-137 190 186 149 223 Pass pCi/L Co-60 98.8 98.8 79.7 118 Pass pCi/L Zn-65 228 240 188 292 Pass 4/8/2024 RAD-137 Water pCi/L Cs-134 60.7 57.8 42.8 72.8 Pass pCi/L Cs-137 185 186 149 223 Pass pCi/L Co-60 97.7 98.8 79.7 118 Pass pCi/L Zn-65 233 240 188 292 Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 56 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 19, CGS Cross Check Intercomparison Results Study Date Study ID Units Radionuclide Reported Value Assigned Value Acceptance Performance Evaluation Lower Limit Upper Limit 4/8/2024 RAD-137 Water pCi/L Cs-134 59.8 57.8 42.8 72.8 Pass pCi/L Cs-137 190 186 149 223 Pass pCi/L Co-60 97.2 98.8 79.7 118 Pass pCi/L Zn-65 240 240 188 292 Pass 4/8/2024 RAD-137 Water pCi/L Cs-134 58.6 57.8 42.8 72.8 Pass pCi/L Cs-137 185 186 149 223 Pass pCi/L Co-60 102 98.8 79.7 118 Pass pCi/L Zn-65 227 240 188 292 Pass 6/13/2024 E14101 Soil pCi/g Cs-134 0.406 0.408 0.286 0.530 Pass pCi/g Cs-137 0.402 0.451 0.316 0.586 Pass 6/13/2024 E14101 Soil pCi/g Cs-134 0.372 0.408 0.286 0.530 Pass 6/13/2024 E14101 Soil pCi/g Cs-137 0.365 0.451 0.316 0.586 Pass 6/13/2024 E14039 Water pCi/L Beta Cs-137 265 262 183 341 Pass 6/13/2024 E14040 Water pCi/L Ce-141 45.4 37.5 26.3 48.8 Pass pCi/L Co-60 402 391 274 508 Pass pCi/L Cr-51 250 291 204 378 Pass pCi/L Cs-134 237 242 169 315 Pass pCi/L Cs-137 233 229 160 298 Pass pCi/L Fe-59 183 174 122 226 Pass pCi/L Mn-54 209 204 143 265 Pass pCi/L Zn-65 89.6 99.1 69.4 129 Pass 6/13/2024 E14040 Water pCi/L Ce-141 40 37.5 26.3 48.8 Pass pCi/L Co-60 397 391 274 508 Pass pCi/L Cr-51 286 291 204 378 Pass pCi/L Cs-134 238 242 169 315 Pass pCi/L Cs-137 237 229 160 298 Pass pCi/L Fe-59 183 174 122 226 Pass pCi/L Mn-54 212 204 143 265 Pass pCi/L Zn-65 95.4 99.1 69.4 129 Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 57 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 19, CGS Cross Check Intercomparison Results Study Date Study ID Units Radionuclide Reported Value Assigned Value Acceptance Performance Evaluation Lower Limit Upper Limit 6/13/2024 E14041 Filter pCi Ce-141 25.4 25.2 17.6 32.8 Pass pCi Co-60 258 262 183 341 Pass 6/13/2024 E14041 Filter pCi Cr-51 211 195 137 254 Pass pCi Cs-134 137 162 113 211 Pass pCi Cs-137 159 153 107 199 Pass pCi Fe-59 132 117 81.9 152 Pass pCi Mn-54 143 137 95.9 178 Pass pCi Zn-65 71.0 66.4 46.5 86.3 Pass 6/13/2024 E14042A Filter pCi Beta Cs-137 249 220 154 286 Pass 9/12/2024 E14043 Filter pCi Beta Cs-137 242 221 84.7 157 Pass 9/12/2024 E14102 Soil pCi/g Cs-134 0.318 0.336 0.235 0.437 Pass pCi/g Cs-137 0.287 0.295 0.207 0.384 Pass 9/12/2024 E14102 Soil pCi/g Cs-134 0.299 0.336 0.235 0.437 Pass pCi/g Cs-137 0.269 0.295 0.207 0.384 Pass 9/12/2024 E14102 Soil pCi/g Cs-134 0.305 0.336 0.235 0.437 Pass pCi/g Cs-137 0.277 0.295 0.207 0.384 Pass 9/12/2024 E14102 Soil pCi/g Cs-134 0.312 0.336 0.235 0.437 Pass pCi/g Cs-137 0.282 0.295 0.207 0.384 Pass 9/16/2024 MRAD-41 Filter pCi Cs-134 499 581 377 712 Pass 9/16/2024 MRAD-41 Filter pCi Cs-137 880 848 696 1110 Pass pCi Co-60 865 839 713 1070 Pass pCi Zn-65 269 239 196 365 Pass 10/4/2024 RAD-139 Water pCi/L Cs-134 79.6 80.2 63.0 97.4 Pass pCi/L Cs-137 49.7 46.3 23.3 69.3 Pass 10/4/2024 RAD-139 Water pCi/L Co-60 47.9 45.3 31.6 59.0 Pass pCi/L Zn-65 108 114 75.0 153 Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 58 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 19, CGS Cross Check Intercomparison Results Study Date Study ID Units Radionuclide Reported Value Assigned Value Acceptance Performance Evaluation Lower Limit Upper Limit 10/4/2024 RAD-139 Water pCi/L Cs-134 79.8 80.2 63.0 97.4 Pass pCi/L Cs-137 46.0 46.3 23.3 69.3 Pass pCi/L Co-60 49.4 45.3 31.6 59.0 Pass pCi/L Zn-65 106 114 75.0 153 Pass 10/4/2024 RAD-139 Water pCi/L Cs-134 79.4 80.2 63.0 97.4 Pass pCi/L Cs-137 46.3 46.3 23.3 69.3 Pass pCi/L Co-60 47.5 45.3 31.6 59.0 Pass pCi/L Zn-65 106 114 75.0 153 Pass 10/4/2024 RAD-139 Water pCi/L I-131 26.4 26.3 22.7 29.9 Pass 10/4/2024 RAD-139 Water pCi/L I-131 26.3 26.3 22.7 29.9 Pass 12/5/2024 E14044 Filter pCi Ce-141 75.7 74.8 52 97 Pass pCi Co-58 105 97.9 69 127 Pass pCi Cr-60 220 219 153 285 Pass pCi Cr-51 182 185 130 241 Pass pCi Cs-134 97.9 116 81 151 Pass pCi Cs-137 144 144 101 187 Pass pCi Fe-59 130 107 75 139 Pass pCi Mn-54 113 104 73 135 Pass pCi Zn-65 164 155 109 202 Pass 12/5/2024 E14044 Filter pCi Ce-141 69.3 74.8 52 97 Pass pCi Co-58 93.7 97.9 69 127 Pass pCi Cr-60 196 219 153 285 Pass pCi Cr-51 166 185 130 241 Pass pCi Cs-134 91.3 116 81 151 Fail 1 pCi Cs-137 135 144 101 187 Pass pCi Fe-59 113 107 75 139 Pass pCi Mn-54 106 104 73 135 Pass pCi Zn-65 146 155 109 202 Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 59 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 19, CGS Cross Check Intercomparison Results Study Date Study ID Units Radionuclide Reported Value Assigned Value Acceptance Performance Evaluation Lower Limit Upper Limit 12/5/2024 E14044 Filter pCi Ce-141 66.6 74.8 52 97 Pass pCi Co-58 92.4 97.9 69 127 Pass pCi Cr-60 204 219 153 285 Pass pCi Cr-51 175 185 130 241 Pass pCi Cs-134 95.7 116 81 151 Pass 12/5/2024 E14044 Filter pCi Cs-137 139 144 101 187 Pass pCi Fe-59 119 107 75 139 Pass pCi Mn-54 102 104 73 135 Pass pCi Zn-65 139 155 109 202 Pass 12/5/2024 E14045 Water pCi/L Beta Cs-137 257 240 168 312 Pass 12/5/2024 E14046 Charcoal pCi I-131 58.0 65.3 45.7 84.9 Pass pCi I-131 59.3 65.3 45.7 84.9 Pass pCi I-131 59.4 65.3 45.7 84.9 Pass 12/5/2024 E14047 Milk pCi/L Ce-141 74.7 71.6 50.1 93.1 Pass pCi/L Co-58 95.2 93.7 65.6 122 Pass pCi/L Co-60 211 210 147 273 Pass pCi/L Cr-51 164 177 124 230 Pass pCi/L Cs-134 114 111 77.7 144 Pass pCi/L Cs-137 150 138 96.6 179 Pass pCi/L Fe-59 112 102 71.4 133 Pass pCi/L I-131 50.1 51.0 35.7 66.3 Pass pCi/L Mn-54 106 99.5 69.7 129 Pass pCi/L Zn-65 141 149 104 194 Pass 12/5/2024 E14047 Milk pCi/L Ce-141 77.8 71.6 50.1 93.1 Pass pCi/L Co-58 96.9 93.7 65.6 122 Pass 12/5/2024 E14047 Milk pCi/L Co-60 208 210 147 273 Pass pCi/L Cr-51 205 177 124 230 Pass pCi/L Cs-134 110 111 77.7 144 Pass pCi/L Cs-137 140 138 96.6 179 Pass pCi/L Fe-59 100 102 71.4 133 Pass pCi/L I-131 45.5 51.0 35.7 66.3 Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 60 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 19, CGS Cross Check Intercomparison Results Study Date Study ID Units Radionuclide Reported Value Assigned Value Acceptance Performance Evaluation Lower Limit Upper Limit pCi/L Mn-54 109 99.5 69.7 129 Pass pCi/L Zn-65 136 149 104 194 Pass 12/5/2024 E14047 Milk pCi/L Ce-141 71.9 71.6 50.1 93.1 Pass pCi/L Co-58 89.7 93.7 65.6 122 Pass pCi/L Co-60 232 210 147 273 Pass pCi/L Cr-51 180 177 124 230 Pass pCi/L Cs-134 113 111 77.7 144 Pass pCi/L Cs-137 149 138 96.6 179 Pass pCi/L Fe-59 112 102 71.4 133 Pass pCi/L I-131 63.3 51.0 35.7 66.3 Pass pCi/L Mn-54 105 99.5 69.7 129 Pass pCi/L Zn-65 148 149 104 194 Pass 1 See Discussion at the beginning of Attachment 3

Annual Radiological Environmental Operating Report YEAR: 2024 Page 61 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 20, Interlaboratory Split Sample Results Sample Type Location Sample Date Analysis Result Units CGS Results w 2 TBE Split Results w 2 Pass/Fail (Split)

Water 4L 1/31/2024 Gross Beta pCi/L 1.47 0.77

<MDA Pass Water 4L 1/31/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 1/31/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 2/28/2024 Gross Beta pCi/L 1.70 0.80 2.15+/-1.33 Pass Water 4L 2/28/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 2/28/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 3/27/2024 Gross Beta pCi/L 1.19 0.71

<MDA Pass Water 4L 3/27/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 3/27/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 3/27/2024 Tritium pCi/L

<MDA

<MDA Pass Water 4L 5/1/2024 Gross Beta pCi/L 1.47 0.71

<MDA Pass Water 4L 5/1/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 5/1/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 5/30/2024 Gross Beta pCi/L 1.45 0.71 2.66+/-1.45 Pass Water 4L 5/30/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 5/30/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 6/27/2024 Gross Beta pCi/L 1.98 0.80 3.32+/-1.40 Pass Water 4L 6/27/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 6/27/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 6/27/2024 Tritium pCi/L

<MDA

<MDA Pass Water 4L 8/1/2024 Gross Beta pCi/L 2.42 0.79 3.98+/-1.63 Pass Water 4L 8/1/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 8/1/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 8/29/2024 Gross Beta pCi/L 2.15 0.80

<MDA Pass Water 4L 8/29/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 8/29/2024 Gamma pCi/L

<MDA

<MDA Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 62 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 20, Interlaboratory Split Sample Results Sample Type Location Sample Date Analysis Result Units CGS Results w 2 TBE Split Results w 2 Pass/Fail (Split)

Water 4L 10/3/2024 Gross Beta pCi/L 2.26 0.81 1.97+/-1.34 Pass Water 4L 10/3/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 10/3/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 10/3/2024 Tritium pCi/L

<MDA

<MDA Pass Water 4L 10/31/2024 Gross Beta pCi/L 2.14 0.80

<MDA Pass Water 4L 10/31/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 10/31/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 12/4/2024 Gross Beta pCi/L 2.26 0.83 2.61+/-1.67 Pass Water 4L 12/4/2024 LLI pCi/L

<MDA

<MDA Pass Water 4L 12/4/2024 Gamma pCi/L

<MDA

<MDA Pass Water 4L 1/2/2025 Gross Beta pCi/L 1.95 0.75 2.13+/-1.31 Pass Water 4L 1/2/2025 LLI pCi/L

<MDA

<MDA Pass Water 4L 1/2/2025 Gamma pCi/L

<MDA

<MDA Pass Water 4L 1/2/2025 Tritium pCi/L

<MDA

<MDA Pass Milk M-11A 2/13/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-11A 2/13/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-13F 2/13/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-13F 2/13/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-7D 2/13/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-7D 2/13/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-11A 5/14/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-11A 5/14/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-13F 5/14/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-13F 5/14/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-7D 5/14/2024 Gamma pCi/L

<MDA

<MDA Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 63 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 20, Interlaboratory Split Sample Results Sample Type Location Sample Date Analysis Result Units CGS Results w 2 TBE Split Results w 2 Pass/Fail (Split)

Milk M-7D 5/14/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-11A 8/6/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-11A 8/6/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-13F 8/6/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-13F 8/6/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-7D 8/6/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-7D 8/6/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-11A 11/12/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-11A 11/12/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-13F 11/12/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-13F 11/12/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-7D 11/12/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-7D 11/12/2024 LLI pCi/L

<MDA

<MDA Pass Filter Composite 1Z/1A 3/27/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite 1Z/1A 6/27/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite 1Z/1A 10/3/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite 1Z/1A 1/2/2025 Gamma pCi/m3

<MDA

<MDA Pass Milk M-13F 5/14/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-13F 5/14/2024 LLI pCi/L

<MDA

<MDA Pass Milk M-7D 5/14/2024 Gamma pCi/L

<MDA

<MDA Pass Milk M-7D 5/14/2024 LLI pCi/L

<MDA

<MDA Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 64 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 20, Interlaboratory Split Sample Results Sample Type Location Sample Date Analysis Result Units CGS Results w 2 TBE Split Results w 2 Pass/Fail (Split)

Vegetation H1-2 6/19/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation H1-2 7/17/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation H1-2 8/14/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation H1-2 9/11/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation B10-2 8/14/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation B10-2 8/14/2024 Strontium 90 pCi/Kg

<MDA

<MDA Pass Fish INDP 10/16/2024 Gamma pCi/Kg

<MDA

<MDA Pass Fish INDP 10/16/2024 Strontium 90 pCi/Kg

<MDA

<MDA Pass Sediment J2-1 10/29/24 Gamma pCi/Kg

<MDA

<MDA Pass Water WA1 6/28/2024 Gamma pCi/L

<MDA

<MDA Pass Water WA2 6/28/2024 Gamma pCi/L

<MDA

<MDA Pass Oysters IA3 6/19/2024 Gamma pCi/Kg

<MDA

<MDA Pass Oysters IA6 6/19/2024 Gamma pCi/Kg

<MDA

<MDA Pass Bottom Sediment WBS4 6/19/2024 Gamma pCi/Kg

<MDA

<MDA Pass Bottom Sediment WBS2 6/19/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation IB10 7/22/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation IB11 7/22/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation IB12 7/22/2024 Gamma pCi/Kg

<MDA

<MDA Pass Vegetation East 7/23/2024 Gamma pCi/Kg

<MDA

<MDA Pass Milk Farm A 09/03/2024 Gamma Gamma pCi/L

<MDA Pass Milk Farm A 09/03/2024 Gamma LLI pCi/L

<MDA Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 65 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 20, Interlaboratory Split Sample Results Sample Type Location Sample Date Analysis Result Units CGS Results w 2 TBE Split Results w 2 Pass/Fail (Split)

Milk Farm B 09/03/2024 Gamma Gamma pCi/L

<MDA Pass Milk Farm B 09/03/2024 Gamma LLI pCi/L

<MDA Pass Milk

55 09/09/2024 Gamma Gamma pCi/L

<MDA Pass Milk

55 09/09/2024 Gamma LLI pCi/L

<MDA Pass Fish (Spanish Mackerel)

IA1 8/14/2024 Gamma pCi/kg

<MDA

<MDA Pass Filter Composite CC-A1 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-A2 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-A3 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-A4 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-A5 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-SFA1 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-SFA2 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-SFA3 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass Filter Composite CC-SFA4 9/30/2024 Gamma pCi/m3

<MDA

<MDA Pass

Annual Radiological Environmental Operating Report YEAR: 2024 Page 66 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 21, Comparison of Gross Beta Results from Split Samples of 1Z and 1A Interlaboratory Split Sample Results (Air Particulate Beta )

Media Location Sample Date Beta pCi/M3 (CGS)

(TBE) 1Z

+/-2 1A

+/-2 Filter 1Z / 1A 1/4/2024 Beta pCi/M3 3.12E-02 2.53E-03 1.74E-02 4.10E-03 Filter 1Z / 1A 1/11/2024 Beta pCi/M3 2.04E-02 2.29E-03 9.27E-03 3.80E-03 Filter 1Z / 1A 1/18/2024 Beta pCi/M3 4.23E-02 2.89E-03 2.19E-02 4.58E-03 Filter 1Z / 1A 1/25/2024 Beta pCi/M3 3.56E-02 2.74E-03 2.10E-02 4.55E-03 Filter 1Z / 1A 1/31/2024 Beta pCi/M3 1.34E-02 2.29E-03 1.08E-02 3.97E-03 Filter 1Z / 1A 2/7/2024 Beta pCi/M3 2.85E-02 2.40E-03 1.39E-02 4.06E-03 Filter 1Z / 1A 2/15/2024 Beta pCi/M3 3.36E-02 2.42E-03 1.87E-02 4.15E-03 Filter 1Z / 1A 2/22/2024 Beta pCi/M3 2.59E-02 2.49E-03 1.71E-02 4.03E-03 Filter 1Z / 1A 2/28/2024 Beta pCi/M3 3.29E-02 2.76E-03 1.86E-02 4.92E-03 Filter 1Z / 1A 3/7/2024 Beta pCi/M3 1.84E-02 2.04E-03 9.35E-03 3.25E-03 Filter 1Z / 1A 3/14/2024 Beta pCi/M3 2.73E-02 2.43E-03 2.06E-02 4.25E-03 Filter 1Z / 1A 3/20/2024 Beta pCi/M3 2.73E-02 2.72E-03 1.13E-02 4.46E-03 Filter 1Z / 1A 3/27/2024 Beta pCi/M3 2.17E-02 2.23E-03 1.15E-02 3.84E-03 Filter 1Z / 1A 4/4/2024 Beta pCi/M3 2.26E-02 2.14E-03 1.63E-02 4.28E-03 Filter 1Z / 1A 4/10/2024 Beta pCi/M3 1.58E-02 2.23E-03 1.13E-02 3.45E-03 Filter 1Z / 1A 4/18/2024 Beta pCi/M3 3.00E-02 2.31E-03 1.95E-02 4.23E-03 Filter 1Z / 1A 4/25/2024 Beta pCi/M3 2.08E-02 2.16E-03 1.33E-02 3.69E-03 Filter 1Z / 1A 5/1/2024 Beta pCi/M3 3.07E-02 2.68E-03 2.27E-02 4.71E-03 Filter 1Z / 1A 5/9/2024 Beta pCi/M3 2.08E-02 2.02E-03 1.43E-02 3.69E-03 Filter 1Z / 1A 5/16/2024 Beta pCi/M3 1.43E-02 1.91E-03 9.14E-03 3.72E-03 Filter 1Z / 1A 5/23/2024 Beta pCi/M3 1.65E-02 2.11E-03 1.17E-02 3.46E-03 Filter 1Z / 1A 6/6/2024 Beta pCi/M3 3.09E-02 2.52E-03 2.34E-02 4.35E-03 Filter 1Z / 1A 6/13/2024 Beta pCi/M3 1.41E-02 1.91E-03 1.39E-02 3.67E-03 Filter 1Z / 1A 6/20/2024 Beta pCi/M3 2.80E-02 2.39E-03 2.33E-02 4.35E-03 Filter 1Z / 1A 6/27/2024 Beta pCi/M3 3.41E-02 2.66E-03 2.35E-02 4.84E-03 Filter 1Z / 1A 7/3/2024 Beta pCi/M3 1.68E-02 2.35E-03 1.30E-02 4.31E-03 Filter 1Z / 1A 7/11/2024 Beta pCi/M3 3.65E-02 2.61E-03 2.53E-02 4.45E-03 Filter 1Z / 1A 7/18/2024 Beta pCi/M3 3.05E-02 2.50E-03 1.95E-02 4.71E-03 Filter 1Z / 1A 7/25/2024 Beta pCi/M3 2.75E-02 2.41E-03 1.95E-02 5.08E-03 Filter 1Z / 1A 8/1/2024 Beta pCi/M3 2.78E-02 2.44E-03 2.18E-02 4.76E-03 Filter 1Z / 1A 8/8/2024 Beta pCi/M3 3.11E-02 2.53E-03 2.74E-02 4.78E-03 Filter 1Z / 1A 8/15/2024 Beta pCi/M3 2.76E-02 2.60E-03 1.62E-02 3.85E-03 Filter 1Z / 1A 8/22/2024 Beta pCi/M3 2.58E-02 2.40E-03 2.21E-02 4.50E-03 Filter 1Z / 1A 8/29/2024 Beta pCi/M3 5.71E-02 3.20E-03 3.91E-02 5.30E-03 Filter 1Z / 1A 9/5/2024 Beta pCi/M3 4.02E-02 2.86E-03 1.47E-02 4.24E-03 Filter 1Z / 1A 9/12/2024 Beta pCi/M3 3.17E-02 2.58E-03 2.66E-02 5.04E-03 Filter 1Z / 1A 9/19/2024 Beta pCi/M3 4.22E-02 2.86E-03 3.88E-02 5.53E-03 Filter 1Z / 1A 9/26/2024 Beta pCi/M3 3.14E-02 2.51E-03 2.42E-02 4.95E-03 Filter 1Z / 1A 10/3/2024 Beta pCi/M3 1.27E-02 1.91E-03 1.24E-02 3.76E-03 Filter 1Z / 1A 10/10/2024 Beta pCi/M3 4.26E-02 2.82E-03 2.67E-02 4.92E-03 Filter 1Z / 1A 10/16/2024 Beta pCi/M3 3.35E-02 2.63E-03 3.04E-02 5.53E-03 Filter 1Z / 1A 10/24/2024 Beta pCi/M3 4.28E-02 2.50E-03 3.42E-02 4.98E-03 Filter 1Z / 1A 10/31/2024 Beta pCi/M3 3.55E-02 2.50E-03 2.56E-02 4.82E-03 Filter 1Z / 1A 11/7/2024 Beta pCi/M3 3.33E-02 2.41E-03 1.97E-02 4.59E-03 Filter 1Z / 1A 11/14/2024 Beta pCi/M3 2.98E-02 2.49E-03 1.97E-02 4.31E-03 Filter 1Z / 1A 11/20/2024 Beta pCi/M3 3.67E-02 2.96E-03 2.95E-02 5.13E-03 Filter 1Z / 1A 11/26/2024 Beta pCi/M3 2.37E-02 2.47E-03 1.55E-02 4.61E-03

Annual Radiological Environmental Operating Report YEAR: 2024 Page 67 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 21, Comparison of Gross Beta Results from Split Samples of 1Z and 1A Interlaboratory Split Sample Results (Air Particulate Beta )

Media Location Sample Date Beta pCi/M3 (CGS)

(TBE) 1Z

+/-2 1A

+/-2 Filter 1Z / 1A 12/4/2024 Beta pCi/M3 3.52E-02 2.42E-03 2.54E-02 4.23E-03 Filter 1Z / 1A 12/12/2024 Beta pCi/M3 3.97E-02 2.61E-03 3.04E-02 4.63E-03 Filter 1Z / 1A 12/19/2024 Beta pCi/M3 2.61E-02 2.32E-03 1.63E-02 3.95E-03 Filter 1Z / 1A 12/26/2024 Beta pCi/M3 3.07E-02 2.50E-03 1.83E-02 4.01E-03 Filter 1Z / 1A 1/2/2025 Beta pCi/M3 2.40E-02 2.26E-03 1.86E-02 4.05E-03

Annual Radiological Environmental Operating Report YEAR: 2024 Page 68 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 22, Comparison of I-131 Results from Split Samples of 1Z and 1A Charcoal 1Z /1A Sample Date I-131 pCi/M3 1Z 1A Charcoal 1Z /1A 1/04/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 1/11/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 1/18/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 1/25/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 1/31/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 2/08/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 2/14/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 2/22/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 2/28/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 3/07/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 3/14/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 3/20/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 3/27/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 4/04/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 4/11/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 4/18/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 4/25/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 5/01/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 5/9/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 5/15/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 5/23/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 5/29/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 6/06/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 6/13/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 6/20/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 6/26/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 7/03/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 7/10/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 7/18/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 7/24/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 8/01/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 8/08/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 8/15/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 8/22/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 8/29/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 9/05/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 9/12/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 9/19/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 9/26/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 10/03/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 10/10/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 10/17/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 10/24/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 10/30/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 11/07/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 11/13/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 11/20/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 11/26/2024 I-131 pCi/M3

<MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 69 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 22, Comparison of I-131 Results from Split Samples of 1Z and 1A Charcoal 1Z /1A Sample Date I-131 pCi/M3 1Z 1A Charcoal 1Z /1A 12/04/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 12/11/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 12/19/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 12/26/2024 I-131 pCi/M3

<MDA

<MDA Charcoal 1Z /1A 1/2/2025 I-131 pCi/M3

<MDA

Annual Radiological Environmental Operating Report YEAR: 2024 Page 70 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

, Environmental Direct Radiation Dosimetry Results Monitoring Location Quarterly

Baseline, BQ (mrem)

BQ +

MDDQ (mrem)

Normalized Quarterly Monitoring Data, MQ Quarterly Facility Dose, FQ=MQ-BQ Annual

Baseline, BA (mrem)

BA + MDDA (mrem)

Annual Monitoring Data, MA (mrem)

Annual Facility Dose, FA=MA-BA (mrem, or ND if FA MDDA)

(mrem)

(mrem, or ND if FQ MDDQ) 1 2

3 4

1 2

3 4

PTLD14 23.2 28.6 21.3 18.7 21.1 22.0 ND ND ND ND 92.8 105.9 83.1 ND PTLD15 23.9 29.3 18.5 25.2 20.2 24.5 ND ND ND ND 95.5 108.6 88.3 ND PTLD16 23.4 28.8 21.1 20.8 20.5 22.1 ND ND ND ND 93.7 106.8 84.6 ND PTLD17 27.2 32.6 25.2 28.7 24.5 24.5 ND ND ND ND 108.9 122.0 102.9 ND PTLD18 23.9 29.3 21.3 21.5 21.6 23.7 ND ND ND ND 95.5 108.6 88.1 ND PTLD19 20.8 26.2 11.9 16.5 13.8 15.5 ND ND ND ND 83.2 96.3 57.6 ND PTLD1A 23.8 29.2 24.6 23.2 21.9 24.5 ND ND ND ND 95.0 108.1 94.1 ND PTLD1B 20.2 25.6 13.2 15.8 16.7 18.0 ND ND ND ND 80.8 93.9 63.8 ND PTLD1C 24.1 29.5 18.6 22.2 21.6 23.7 ND ND ND ND 96.3 109.4 86.1 ND PTLD1D 23.4 28.8 19.1 19.9 20.2 20.3 ND ND ND ND 93.8 106.9 79.5 ND PTLD1E 22.8 28.2 19.6 20.9 20.2 19.1 ND ND ND ND 91.2 104.3 79.8 ND PTLD1F 27.0 32.4 18.7 25.3 25.5 25.7 ND ND ND ND 108.0 121.1 95.2 ND PTLD1G 15.9 21.3 13.1 12.4 11.7 13.7 ND ND ND ND 63.4 76.5 51.0 ND PTLD1H 23.6 29.0 19.0 21.0 21.5 23.3 ND ND ND ND 94.4 107.5 84.8 ND PTLD1I 21.4 26.8 17.5 18.8 18.7 20.1 ND ND ND ND 85.6 98.7 75.3 ND PTLD1J 27.3 32.7 21.9 22.6 25.7 26.3 ND ND ND ND 109 122.1 96.6 ND PTLD1K 26.4 31.8 20.7 29.0 26.1 27.6 ND ND ND ND 105.5 118.6 103.3 ND PTLD1L 19.4 24.8 19.2 18.5 18.5 18.6 ND ND ND ND 77.6 90.7 74.8 ND PTLD1M 14.0 19.4 9.2 13.2 8.8 11.5 ND ND ND ND 56.1 69.2 42.6 ND PTLD1NN 25.5 30.9 20.1 22.7 22.7 23.3 ND ND ND ND 102.1 115.2 88.7 ND PTLD1P 16.1 21.5 12.4 14.9 13.9 15.3 ND ND ND ND 64.6 77.7 56.6 ND PTLD1Q 18.7 24.1 13.9 15.8 15.4 16.9 ND ND ND ND 74.9 88.0 62.1 ND PTLD1R 24.0 29.4 25.9 31.9 31.6 28.0 83.1 83.1 83.1 83.1 96.0 109.1 117.5 21.5 PTLD1T 24.1 29.5 18.0 21.5 20.6 22.8 ND ND ND ND 96.5 109.6 83.0 ND PTLD2 23 28.4 17.9 20.4 19.9 24.1 ND ND ND ND 92.2 105.3 82.4 ND PTLD22 24.3 29.7 19.8 23.3 22.4 21.7 ND ND ND ND 97.0 110.1 87.2 ND PTLD23 24.9 30.3 21.7 23.3 19.9 24.4 ND ND ND ND 99.7 112.8 89.3 ND PTLD24 18.1 23.5 13.4 13.7 11.2 13.8 ND ND ND ND 72.3 85.4 52.1 ND PTLD26 26.0 31.4 19.4 20.9 21.3 24.7 ND ND ND ND 104.1 117.2 86.4 ND PTLD27 24.7 30.1 18.8 22.4 20.2 24.3 ND ND ND ND 98.8 111.9 85.7 ND

Annual Radiological Environmental Operating Report YEAR: 2024 Page 71 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Monitoring Location Quarterly

Baseline, BQ (mrem)

BQ +

MDDQ (mrem)

Normalized Quarterly Monitoring Data, MQ Quarterly Facility Dose, FQ=MQ-BQ Annual

Baseline, BA (mrem)

BA + MDDA (mrem)

Annual Monitoring Data, MA (mrem)

Annual Facility Dose, FA=MA-BA (mrem, or ND if FA MDDA)

(mrem)

(mrem, or ND if FQ MDDQ) 1 2

3 4

1 2

3 4

PTLD2B 22.1 27.5 16.1 20.7 20.2 19.8 ND ND ND ND 88.4 101.5 76.8 ND PTLD31A 19.9 25.3 17.0 18.2 17.2 16.0 ND ND ND ND 79.6 92.7 68.5 ND PTLD32 25.4 30.8 20.0 22.6 19.0 24.5 ND ND ND ND 101.7 114.8 86.1 ND PTLD3A 17.3 22.7 13.0 16.3 13.4 16.6 ND ND ND ND 69.3 82.4 59.4 ND PTLD40 27.8 33.2 20.7 22.0 27.7 28.0 ND ND ND ND 111.2 124.3 98.6 ND PTLD42 21.0 26.4 15.1 13.4 10.5 18.0 ND ND ND ND 84.2 97.3 57.0 ND PTLD43 26.5 31.9 24.0 25.6 25.0 24.7 ND ND ND ND 106.1 119.2 99.2 ND PTLD44 22.8 28.2 17.4 20.3 18.4 21.6 ND ND ND ND 91.3 104.4 77.7 ND PTLD45 24.5 29.9 19.9 23.7 19.1 20.7 ND ND ND ND 98.2 111.3 83.3 ND PTLD46 21.0 26.4 18.3 18.4 19.5 20.9 ND ND ND ND 84.2 97.3 77.0 ND PTLD47 26.0 31.4 19.7 23.5 22.5 26.1 ND ND ND ND 103.8 116.9 91.8 ND PTLD48 24.3 29.7 19.8 21.6 23.4 23.4 ND ND ND ND 97.1 110.2 88.3 ND PTLD49 24.0 29.4 18.0 22.0 20.6 23.9 ND ND ND ND 95.8 108.9 84.5 ND PTLD4K 15.1 20.5 10.6 10.2 13.3 12.1 ND ND ND ND 60.3 73.4 46.1 ND PTLD5 22.0 27.4 23.1 19.2 18.7 18.9 ND ND ND ND 87.8 100.9 79.9 ND PTLD50 28.1 33.5 22.8 28.4 23.4 28.5 ND ND ND ND 112.2 125.3 103.0 ND PTLD51 23.6 29.0 17.4 22.1 23.3 19.6 ND ND ND ND 94.5 107.6 82.4 ND PTLD6B 19.8 25.2 15.7 17.4 17.2 17.0 ND ND ND ND 79.1 92.2 67.4 ND MDDQ = Quarterly Minimum Differential Dose = 5.4 mrem MDDA = Annual Minimum Differential Dose = 13.1 mrem ND = Not Detected, where MQ (BQ+MDDQ) or MA (BA+MDDA)

Annual Radiological Environmental Operating Report YEAR: 2024 Page 72 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station

Radiological Groundwater Protection Program 1.0 Results Summary Peach Bottom Generating Station has a total of 24 wells (three Background wells, four Long-Term Shutdown wells, five Mid-Field wells, three Perimeter wells, and nine Source wells), two bedrock seeps (monitored as Mid-Field sample points), and two yard drain locations (monitored as Source sample points), that are sampled as part of the Station RGPP (EN-PB-408-4160). Figure 1a shows the surface water and overburden aquifer RGPP sample locations and Figure 1b shows the bedrock aquifer RGPP sample locations.

RGPP sampling at the Station is performed by Constellation Generation Services, under contract to Constellation. Laboratory testing is performed by Teledyne Brown Engineering. The laboratory data, field data, and depth to water readings are uploaded to the RACER website, which is a data repository for the RGPP sampling rounds.

Note that previously obstructed monitoring well MW-PB-11 was recently found and in operable condition, east of MW-PB-30, near the Administration Building A. This well was sampled as part of the MW-PB-30 groundwater investigation. This well should be incorporated into the RGPP as a Mid-Field designated well since it is downgradient of MW-PB-30 and the southern Moisture-Separator Room.

Tritium Peach Bottom has 24 monitoring wells, two bedrock seeps (monitored as Mid-Field sample points), and two yard drain locations (monitored as Source sample points) that are sampled for tritium. Samples collected from Source and Long-Term designated wells are analyzed for tritium quarterly; samples collected from Mid-Field designated wells are analyzed for tritium semi-annually, and samples collected from Background and Perimeter designated wells are analyzed for tritium annually.

The tritium concentration in a groundwater sample collected from MW-PB-30 on August 13, 2024 increased from 1,100 pCi/L to 112,000 pCi/L. Station personnel found that a penetration in a sump in the southern Moisture Separator Room allowed tritiated water to migrate to groundwater. Monitoring well MW-PB-30 is located approximately ten feet from the sump. The Station installed a barrier around the sump to stop water from entering. Tritium concentrations show a decreasing trend since the barrier was installed. As of September 24, 2024, the tritium concentration was 4,340 pCi/L. Although the tritium concentration spiked in the sample collected from MW-PB-30 during the 4th quarter 2024 RGPP round (29,700 pCi/L), tritium concentrations continue to show a decreasing trend since the barrier was installed. As of December 10,2024, the tritium concentration was 9,010 pCi/L.

Gross-Alpha Gross-alpha analysis was most recently performed on Source and Long-Term Shutdown designated wells, during the 2nd quarter 2024 RGPP sampling round. Gross-alpha (dissolved and suspended) was not detected at concentrations greater than their respective Alert Levels in the samples collected during the 2nd quarter 2024 RGPP sampling round.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 73 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Per the RGPP, all Long-Term Shutdown and Source designated wells will have gross-alpha analysis performed again in 2026.

Gamma-Radionuclides Gamma-radionuclide analysis has been performed on RGPP samples (quarterly to annually) at Peach Bottom Generating Station since 2006. This extensive sampling and analysis produced over 10,800 data records for the Station. Gamma-radionuclides have not been detected at concentrations greater than their respective LLDs, in RGPP samples submitted to the vendor laboratory since 2006. Therefore, in the 2020 RGPP, gamma-radionuclide analysis frequency was reduced from annual to every two years.

Gamma-radionuclide analysis was most recently performed during the 2nd quarter 2024 RGPP sampling round. Station-related gamma radionuclides were not detected at concentrations exceeding their respective LLDs in 2024. Per the RGPP, the next time gamma-radionuclide analysis will be performed is 2026.

Select Transuranics Select transuranics analysis is procedurally required annually for former Elevated designated (current Source designated) well MW-PB-25. Additionally, EN-PB-408-4160 requires select transuranics analysis if a gross alpha concentration exceeds the Alert Level in a particular well, there is an unexpected increase in tritium activity, and if a non-tritium licensed material result exceeds the High Level as established by the RGPP.

U-233/234 was detected in the sample collected from MW-PB-25 at 0.4276 pCi/L, during the 2nd quarter 2024 RGPP sampling round; U-238 was also detected in the sample collected from MW-PB-25 at 0.2269 pCi/L. The detected uranium concentrations are similar to those reported in the past and are considered background concentrations because no Station related transuranics, gamma-radionuclides, Fe-55, Ni-63, and Sr-89/90 were detected in the sample collected from MW-PB-25. Table 2 provides a summary of select transuranics results (U-233/234 and U-238) since 2006.

Select transuranics analysis was performed on the sample collected from MW-PB-30 during the 3rd quarter 2024, due to the unexpected increase in tritium concentration to 112,000 pCi/L.

Select transuranics were not detected in the MW-PB-30 sample collected in the 3rd quarter 2024.

Hard-to Detects (Fe-55 and Ni-63)

Hard-to-detect analysis (Fe-55 and Ni-63) is procedurally required annually for former Elevated designated (current Source designated) well MW-PB-25, as well as Long-Term Shutdown designated wells. As part of the current EN-PB-408-4160, hard-to-detect analysis is warranted on samples collected from Source designated wells once every 5 years, starting in 2021.

Additionally, hard-to-detect analyses is required if there is an unexpected increase in tritium activity, and if a non-tritium licensed material result exceeds the High Level as established by the RGPP.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 74 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station The 2nd quarter 2024 samples collected from Long-Term Shutdown designated well and Source designated well MW-PB-25, and the 3rd quarter 2024 sample collected from MW-PB-30, were analyzed for hard-to-detects (Fe-55 and Ni-63). Hard-to-detects (Fe-55 and Ni-63) were not detected in the samples collected during the 2nd and 3rd quarter 2024. Long-Term Shutdown designated wells will have Fe-55 and Ni-63 analysis performed in 2025. Source designated wells will have Fe-55 and Ni-63 analysis performed again in 2026.

Sr-89 and Sr-90 Sr-89 and Sr-90 have been an annual procedurally required analysis on Detection, Long-Term Shutdown, and Elevated designated wells since sample point designations became part of the RGPP in 2010. EN-PB-408-4160 states that Sr-89 and 90 analyses should be performed annually for Source and Long-Term Shutdown designated sample locations. If a positive result is reported, samples collected from wells with the Sr-89 and Sr-90 detections, will be analyzed quarterly to evaluate the activity in the area of the well.

In 2024, samples were collected from the eleven Source designated sample locations and four Long-Term Shutdown designated wells during the 2nd quarter 2024 RGPP sampling round and from MW-PB-30 during the 3rd quarter 2024 RGPP sampling round. Sr-89 and Sr-90 were not detected in the samples collected during the 2nd and 3rd quarter 2023 RGPP sampling round.

Precipitation Recapture Peach Bottom Generating Station is a Boiling Water Reactor (BWR) generating station. The RGPP requires BWR generating stations to sample precipitation on a semi-annual basis. In 2020, the RGPP was modified to increase the minimum number of samples to eight recapture sample locations and to focus sample locations in areas close to atmospheric release points or areas that could receive atmospheric recapture. The RGPP states that a minimum of eight samples should be collected from within the protected area in a manner that surrounds the Turbine Building and Reactor Building as well as ancillary structures that could vent tritiated vapor to the atmosphere.

RGPP precipitation samples were collected in January and July 2024. Eight precipitation samples were collected across the Station during both sampling rounds. Tritium was detected at concentrations greater than 200 pCi/L in six of the sixteen recapture samples collected in 2024. The maximum tritium concentration was 380 pCi/L, in the sample collected from PB-P3.

Figure 10, Surface Water and Overburden RGPP Monitoring Locations Figure 11, Bedrock Seep and Bedrock RGPP Monitoring Locations Figure 12, Precipitation Recapture Sample Locations

Annual Radiological Environmental Operating Report YEAR: 2024 Page 75 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 10, Surface Water and Overburden RGPP Monitoring Locations

Annual Radiological Environmental Operating Report YEAR: 2024 Page 76 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 11, Bedrock Seep and Bedrock RGPP Monitoring Locations

Annual Radiological Environmental Operating Report YEAR: 2024 Page 77 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Figure 12, Precipitation Recapture Sample Locations

Annual Radiological Environmental Operating Report YEAR: 2024 Page 78 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 23, Groundwater Protection Results for the Specific Analytes Analysis Program Complete RGPP Results (in pCi/L)

Location Sample Date Gross Alpha (dissolved)

Gross Alpha (suspended)

U-233/234 U-238 Sr-89/90 Gamma Emitters*

Ni-63 MW-PB-1 6/4/24 ND ND ND ND ND

<MDA ND 12/10/24 ND ND ND ND ND

<MDA ND MW-PB-10 6/5/24 1.44 3.03 ND ND

<MDA

<MDA MW-PB-12 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-13 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-15 6/5/24 1.42 0.961 ND ND

<MDA

<MDA MW-PB-16 6/5/24 10.3 14.3 ND ND

<MDA

<MDA MW-PB-19 6/4/24 0.517 1.15 ND ND

<MDA

<MDA ND MW-PB-2 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-20 6/4/24 2.23 2.8 ND ND

<MDA

<MDA ND MW-PB-22 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-24 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-25 6/4/24 1.44 0.926 0.4276 0.2269

<MDA

<MDA MW-PB-26 6/4/24 2.83 1.15 ND ND

<MDA

<MDA ND MW-PB-27 6/4/24 4.46 1.48 ND ND

<MDA

<MDA ND MW-PB-28 6/4/24 1.17 4.44 ND ND

<MDA

<MDA ND MW-PB-29 6/4/24 0.511 1.05 ND ND

<MDA

<MDA ND MW-PB-3 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-30 6/4/24 0.47 1.12 ND ND

<MDA

<MDA ND 8/16/24 ND ND

<MDA

<MDA MW-PB-31 6/4/24 0.827 1.06 ND ND

<MDA

<MDA ND MW-PB-4 6/4/24 ND ND ND ND ND

<MDA ND MW-PB-7 6/5/24 ND ND ND ND ND

<MDA ND MW-PB-8 6/5/24 1.52 1.37 ND ND

<MDA

<MDA U/2 YARD 6/7/24 1.3 1.05 ND ND

<MDA

<MDA ND U/3 YARD 6/4/24 0.918 1.15 ND ND

<MDA

<MDA ND ND No Data, Sample collected as required.

<MDA Less than minimum detectable activity.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 79 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 24, Groundwater Protection Results for Tritium Concentration of Tritium in Groundwater (in pCi/L)

Location Q1 Q2 Q3 Q4 U/2 YARD

<MDA 211

<MDA

<MDA U/3 YARD 567 816 769 781 MW-PB-25 606 493

<MDA 238 MW-PB-12 ND ND 249 268 MW-PB-22 ND

<MDA ND

<MDA MW-PB-10

<MDA

<MDA MW-PB-15

<MDA

<MDA MW-PB-20

<MDA

<MDA MW-PB-31

<MDA

<MDA 220 567 MW-PB-4 ND

<MDA ND 266 MW-PB-5

<MDA

<MDA ND ND MW-PB-6

<MDA

<MDA ND ND MW-PB-7 ND 201 ND ND MW-PB-8

<MDA

<MDA MW-PB-24 ND 224 ND

<MDA MW-PB-29 374 578 683 674 MW-PB-26 518 991 1,910 1,560 MW-PB-30 295 1,100 112,000*

2,480 4,340 29,700**

9,010 SP-PB-1

<MDA

<MDA 216 SP-PB-2

<MDA

<MDA MW-PB-19 279

<MDA

<MDA MW-PB-1 ND

<MDA ND ND MW-PB-13 ND ND

<MDA 294 MW-PB-16

<MDA

<MDA MW-PB-2*

ND

<MDA ND ND MW-PB-3 ND

<MDA ND ND MW-PB-28

<MDA 300

<MDA

<MDA MW-PB-27 1,040 1,770 4,110 2,600 ND No Data, Sample collected as required.

<MDA Less than minimum detectable activity.

Sample was obtained on 8/13/24. MW-PB-30 was resampled on 8/16/24 and 9/24/24 for tritium values of 2,480 pCi/L and 4,340 pCi/L, respectively.

- First sample was obtained on 11/5/24 with a tritium concentration of 29,700 pCi/L, and the resample on 12/10/24 resulted in a tritium concentration of 9,010 pCi/L.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 80 of 80 Company: Constellation Plant: Peach Bottom Atomic Power Station Table 25, Tritium Precipitation Results Concentration of Tritium in Precipitation Recapture (pCi/L)

Location 2/21/2024 8/28/2024 PB-P1

<MDA

<MDA PB-P2

<MDA

<MDA PB-P3

<MDA 380 PB-P4 234 243 PB-P5

<MDA

<MDA PB-P6 325

<MDA PB-P7 317

<MDA PB-P8 250

<MDA

<MDA Less than minimum detectable activity.

ML25140A114

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