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Annual Radiological Environmental Operating Report
	ML25135A014
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Site:	Braidwood
Issue date:	05/15/2025
From:	; Constellation Energy Generation
To:	; Office of Nuclear Reactor Regulation
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~-=" Constellation Braidwood Nuclear Power Station 2024 Annual Radiological Environmental Operating Report Document Number: 50-456/50-457

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 1 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 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

........................................................................................................................ 6 4.0 SITE DESCRIPTION AND SAMPLE LOCATIONS..................................................................... 7 5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM REQUIREMENTS................ 8 6.0 MAPS OF COLLECTION SITES.............................................................................................. 13 7.0 REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES................................................................................................. 16 8.0 SAMPLING PROGRAM, PROGRAM MODIFICATION AND INTEPRETATION OF RESULTS................................................................................................................................ 17 8.1 Environmental Direct Radiation Dosimetry Results....................................................... 17 8.2 Air Particulate and Radioiodine Sample Results........................................................... 18 8.3 Waterborne Sample Results......................................................................................... 19 8.4 Ingestion Pathway Sample Results............................................................................... 21 9.0 LAND USE CENSUS............................................................................................................... 23 10.0 SAMPLE DEVIATIONS, ANOMALIES AND UNAVAILABILITY................................................ 25 11.0 OTHER SUPPLEMENTAL INFORMATION............................................................................. 27 11.1 NEI 07-07 Onsite Radiological Groundwater Monitoring Program................................. 27 11.2 Corrections to Previous Reports................................................................................... 27 12.0 BIBLIOGRAPHY...................................................................................................................... 28 TABLES Table 1: Radiological Environmental Sampling Program - Exposure Pathway - Direct Radiation......... 8 Table 2, Radiological Environmental Sampling Program - Exposure Pathway -Airborne...................... 8 Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne................. 9 Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion................... 10 Table 5, REMP Sampling Locations - Direct Radiation........................................................................ 11 Table 6, Reporting Levels for Radioactivity Concentrations in Environmental Samples....................... 16 Table 7, Maximum Values for the Limit of Detection............................................................................ 16 Table 8: Land Use Census - Nearest Receptors within 8 miles........................................................... 24 Table 9: Sample Deviation Summary................................................................................................... 25 Table 10: Braidwood Data Summary Table.......................................................................................... 30 Table 11, 'vVeekly Aii Particulate Gross Beta (E-3 pCi/m3).................................................................... 37 Table 12: Quarterly Air Particulate Gamma Isotopic (pCi/m3 +/- 2 Sigma).............................................. 40 Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3)..................................................................................... 42 Table 14, Monthly/Bi-Weekly Milk 1-131 (pCi/L +/- 2 Sigma)................................................................... 45 Table 15: Monthly/Bi-Weekly Milk Gamma Isotopic (pCi/L +/- 2 Sigma)................................................. 46 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)................................................ 47 Table 17, Monthly Surface Water Gross Beta (pCi/L +/- 2 Sigma)......................................................... 54 Table 18, Monthly Surface Water Nickel-63 and lron-55 (pCi/L +/- 2 Sigma).......................................... 55

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 2 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma).................................................. 56 Table 20, Quarterly Surface Water Tritium (pCi/L +/- 2 Sigma).............................................................. 62 Table 21, Monthly Public Water Gross Beta, Tritium, lron-55, Nickel-63, and 1-131 (pCi/L +/- 2 Sigma). 63 Table 22, Monthly Public Water Gamma Isotopic (pCi/L +/- 2 Sigma).................................................... 64 Table 23, Quarterly Groundwater Tritium (pCi/L +/- 2 Sigma)................................................................. 65 Table 24, Quarterly Ground Water Gamma Isotopic (pCi/L +/- 2 Sigma)................................................ 66 Table 25, Semi-Annual Fish lron-55, Nickel-63, and Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)............ 69 Table 26, Semi-Annual Shoreline Sediment lron-55, Nickel-63, and Gamma Isotopic (pCi/kg Dry+/- 2 Sigma)................................................................................................................................................. 70 Table 27: Analytics Environmental Radioactivity Cross Check Program.............................................. 74 Table 28: DOE's Mixed Analyte Performance Evaluation Program (MAPEP)...................................... 76 Table 29: ERA Environmental Radioactivity Cross Check Program..................................................... 78 FIGURES Figure 1, Potential exposure pathways to Members of the Public due to Plant Operations [7]............... 6 Figure 2, Inner Ring and Other OSLO Locations of Braidwood Station, 2024...................................... 13 Figure 3, Fixed Air Sampling and Outer Ring OSLO Locations for Braidwood Station, 2024................ 14 Figure 4, Ingestions and Waterborne Exposure Pathway Sample Locations of Braidwood Station, 2024

- - - - 15 Figure 5, Air Particulate: Analysis for Gross Beta, Average for All Indicator vs. Control Location......... 18 Figure 6: Surface Water Tritium Results.............................................................................................. 19 Figure 7: Public Water Gross Beta Sample Indicator Comparison....................................................... 20 Figure 8: Public Water Tritium Sample Results.................................................................................... 21 ATTACHMENTS, Data Table Summary.................................................................................................... 30, Complete Data Table for All Analysis Results Obtained in 2024................................... 37, Cross Check lntercomparison Program......................................................................... 71, Environmental Direct Radiation Dosimetry Results....................................................... 79

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 3 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 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 (OSLO) 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 I YEAR: 2024 I

Page 4 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2

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.

OSLO: Optically Stimulated Luminescence Dosimeter

26.

pCi/L: picocuries / Liter

27.

PWR: Pressurized Water Reactor

28.

REMP: Radiological Environmental Monitoring Program

29.

TLD: Thermoluminescent Dosimeter 2.0 EXECUTIVE

SUMMARY

Braidwood Station Units 1 and 2 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 Braidwood Station 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). The program compares data from Indicator locations near the plant, to Control locations farther away from the site to assess operation impacts.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 5 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 2.1 The Annual Radiological Environmental Operating Report (AREOR) provides data obtained through analyses of environmental samples collected at Braidwood Station for the reporting period of January 1st through December 31st, 2024. During that time period 1,589 analyses were performed on 1,280 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 Braidwood Station had no adverse radiological impact on the enviroment.

Summary of

Conclusions:

All values were consistent with historical results which indicate no adverse radiological environmental impacts associated with the operation of Braidwood Station. 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-?, 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. Detailed information on the exposure of the U.S. population to ionizing radiation can be found in NCRP Report No. 160 [1].

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 6 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2

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].

0.

Gaseous cffiucnts

~I

~.......

J0kposition Livestock products

(

- - - - lngcstionf-..~':lf"'lt.

\ Inhalation I ngcstion

************* l

Radiation o

Radionuclides

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

Quality assurance aspects of the sampling program and TLD/OSLD data collection are conducted in accordance with Regulatory Guides 4.15 [8] and 4.13 [9]. REMP also adheres to the requirements of the state of Illinois, Braidwood Station 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 7 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 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 The Braidwood Station, consisting of two 3,645 MWt pressurized water reactors owned and operated by Constellation is located in Will County, Illinois. Unit No. 1 went critical on May 29, 1987. Unit No. 2 went critical on March 08, 1988. The site is located in northeastern Illinois, 20 miles south-southwest of Joliet, Illinois, 60 miles southwest of Chicago and southwest of the Kankakee River.

Braidwood Station 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 Sampling Program - Exposure Pathway -

Direct Radiation Table 2, Radiological Environmental Sampling Program - Exposure Pathway -

Airborne Table 3, Radiological Environmental Sampling Program - Exposure Pathway-Waterborne Table 4, Radiological Environmental Sampling Program - Exposure Pathway-Ingestion Table 5, REMP Sampling Locations - Direct Radiation Figure 2, Inner Ring and Other OSLO Locations of Braidwood Station, 2024 Figure 3, Fixed Air Sampling and Outer Ring OSLO Locations for Braidwood Station, 2024 Figure 4, Ingestions and Waterborne Exposure Pathway Sample Locations of Braidwood Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 \

Page 8 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM REQUIREMENTS Table 1: Radiological Environmental Sampling Program - Exposure Pathway - Direct Radiation Sample Location Description, Sampling Requirement Distance, and Direction Collection/

Type and Frequency of Analyses Frequency Direct Radiation 48 OSLD monitoring stations with two dosimeters placed as follows:

An inner ring of stations, one in each compass sector in the general area of the site boundary.

See Table 5 Quarterly Gamma dose Quarterly An outer ring of stations, one in each compass sector at approximately 5 miles from the site An additional set located at the eight fixed air sampling locations An ISFSI set Table 2, Radiological Environmental Sampling Program - Exposure Pathway - Airborne Sample Location Description, Sampling Type and Frequency of Analyses Collection/

Requirement Distance, and Direction Frequency Airborne Radioiodine and Particulates BD-02 Custer Park, 5.0 miles E One week composite of Particulate sampler: Gross Beta Samples from 8 locations:

BD-03 County Line Road (Control), 6.2 continuous air analysis following weekly filter change miles ESE sampling through and Gamma isotopic quarterly on Four locations close to the site boundary in different BD-04 Essex, 4.8 miles SSE glass fiber filter composite filters by location on near sectors of the highest calculated annual average ground BD-05 Gardner, 5.5 miles SW paper. Weekly field and control samples.

composite of level D/Q.

BD-06 Godley, 0.5 miles WSW continuous air Three samples from the vicinity of a community having the sampling through Radioiodine canister: 1-131 analysis BD-19 Nearsite NW, 0.3 miles NW charcoal filter.

weekly on near field and control highest calculated annual average D/Q.

BD-20 Nearsite N, 0.6 miles N Quarterly samples.

composite of One sample from Control Locations between 4 - 8 miles BD-21 Nearsite NE, 0.5 miles NE each station away in the least predominant wind direction.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 9 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne Requirement Sample Location Description, Distance, Sampling Collection/

Type and Frequency of Analyses and Direction Frequency BD-10 Kankakee River Downstream, 5.4 miles NE BD-25 Kankakee River Upstream (Control),

Monthly composite Gamma isotopic Monthly Surface Water 9.6 miles E sample from weekly Gross Beta Monthly One sample upstream BD-38 Main Drainage Ditch, 1.5 miles S grab samples; Fe-55 Monthly (control) and five samples BD-40 Braidwood Station Cooling Lake, quarterly composite Ni-63 Monthly from weekly grab downstream Onsite (1.0 mile E) samples H-3 Quarterly BD-55 North Pond Fatlan Site, 0.6 miles NE BD-56 South Pond Fatlan Site, 0.6 miles NE H-3 Monthly Weekly grab samples; Gamma isotopic Monthly Public Water Monthly composites Gross Beta Monthly One sample downstream BD-22 Wilmington, 6.0 miles NE from weekly grab 1-131 (Low Level) Monthly (indicator) samples Fe-55 Monthly Ni-63 Monthly BD-13 Braidwood City Hall Well, 1.7 miles NNE BD-34 Gibson Well, 4.7 miles E Groundwater/Well Water BD-35 Joly Well, 4.7 miles E Gamma isotopic Quarterly BD-36 Hutton Well, 4.7 miles E Quarterly grab H-3 Quarterly Eight indicator locations down BD-37 Nurczyk Well, 4.7 miles E samples gradient from the plant BD-50 Skole Well, 4.7 miles E BD-51 Fatlan Well, 0.6 miles NE BD-54 Cash Well, 0.9 miles NE BD-10 Kankakee River, Downstream, 5.4 Sediment from Shoreline miles NE Gamma isotopic Semiannually One sample upstream BD-25 Kankakee River Upstream (Control),

Semiannual grab Ni-63 Semiannually (control) and two samples 9.6 miles E samples Fe-55 Semiannually downstream (indicator)

BD-57 Circulating Water Slowdown Discharge, 5.4 miles E

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 10 of 81 Company_:_C:onstellation I Plant: Braidwood Station Units 1 and 2 Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion Requirement Sample Location Description, Distance, and Sampling Collection/

Type and Frequency Direction Frequency of Analyses Goat milk Gamma isotopic and One sample from a milking animal at BD-18A 8270 Duck Pond Rd, Coal City, IL Biweekly when animals 1-131 Biweekly when a control location 15 to 30 km 60416(Control), 6.2 miles NNW are on pasture; monthly animals are on pasture; distant and in the least prevalent at other times monthly at other times.

wind direction.

Fish Gamma isotopic One sample upstream and two BD-25 Kankakee River, Upstream (Control), 9.6 analysis on edible samples downstream for each miles E portions commercially and recreationally BD-28 Kankakee River, Discharge, 5.4 miles E Semiannually Ni-63 on edible portions important species in vicinity of site BD-41 Cooling Lake, Onsite (1.0 mile E)

Fe-55 on edible discharge.

portions Vegetation BWD-G1 Nearsite NE, 0.54 miles NE Seven locations producing BWD-G2 Nearsite W, 0.21 miles W vegetables from areas irrigated by Quadrant 1 Clark Farm, 3.8 miles ENE Grab samples during Gamma isotopic on water in which liquid plant wastes Quadrant 2 W.F. Soltwisch, 4.5 miles SSE the growing season each sample have been discharged and one Quadrant 3 Bruce Corsini, 5.4 miles SSW sample collected from a control Quadrant 4 Bruce Sinkular, 1.9 miles NNW location.

Control Gorman Farm, 9.0 miles NE

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 11 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2 Table 5, REMP Sampling Locations - Direct Radiation Site#

Location Sector Distance Description Type 80-101 Inner Ring N

0.5 miles80-102 Inner Ring NNE 1.1 miles80-103 Inner Ring NE 1.0 mile 80-104 Inner Ring ENE 0.7 miles80-105 Inner Ring E

2.2 miles80-106 Inner Ring ESE 2.5 miles 8D-107 Inner Ring SE 3.2 miles80-108 Inner Ring SSE 3.2 miles80-109 Inner Ring s

3.8 miles80-110 Inner Ring SSW 2.8 miles 8O-111a Inner Ring SW 1.4 miles80-112 Inner Ring WSW 0.7 miles 8O-113a Inner Ring w

0.5 miles80-114 Inner Ring WNW 0.4 miles80-115 Inner Ring NW 0.3 miles80-116 Inner Ring NNW 0.4 miles 8D-201 Outer Ring N

4.2 miles80-202 Outer Ring NNE 4.8 miles 8D-203 Outer Ring NE 4.9 miles80-204 Outer Ring ENE 4.3 miles80-205 Outer Ring E

4.0 miles80-206 Outer Ring ESE 4.5 miles

Annual Radiological Environmental Operating Reeort I YEAR: 2024 I

Page 12 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 5, REMP Sampling Locations - Direct Radiation Site#

Location Sector Distance Description Type BD-207 Outer Ring SE 4.5 miles BD-208 Outer Ring SSE 4.5 miles BD-209 Outer Ring s

4.8 miles BD-210 Outer Ring SSW 5.3 miles BD-211 Outer Ring SW 4.8 miles BD-212 Outer Ring WSW 5.0 miles BD-213 Outer Ring w

4.8 miles BD-214 Outer Ring WNW 4.3 miles BD-215 Outer Ring NW 4.5 miles BD-216 Outer Ring NNW 4.0 miles BD-02 Other E

5.0 miles Custer Park (indicator)

BD-03 Other ESE 6.2 miles 13000 W. Road (control)

BD-04 Other SSE 4.8 miles Essex (indicator)

BD-05 Other SW 5.5 miles Gardner (indicator)

BD-06 Other WSW 0.5 miles Godley (indicator)

BD-19 Other NW 0.3 miles Nearsite NW (indicator)

BD-20 Other N

0.6 miles Nearsite N (indicator)

BD-21 Other NE 0.5 miles Nearsite NE (indicator)

BD-ISFSl-104-3 ISFSI E

0.11 miles BD-ISFSl-104-4 ISFSI E

0.13 miles BD-ISFSl-105-3 ISFSI SE 0.23 miles BD-ISFSl-105-4 ISFSI SE 0.20 miles BD-ISFSl-110-3 ISFSI SE 0.18 miles BD-ISFSl-110-4 ISFSI SE 0.15 miles

Annual Radiological Environmental Operating Report

[ YEAR: 2024 [

Page 13 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 6.0 MAPS OF COLLECTION SITES A

2. lrner R1rg Jcs11nete~s N

Figure 2, Inner Ring and Other OSLD Locations of Braidwood Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 14 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 BO-Z10 Legend 111 1 R-,idwnorl "t,t,nn 2 Cuter c;:,ng Oosrn?ters

~

t\lr s~mrhnc1 ! O!~.::rinn.:::

Figure 3, Fixed Air Sampling and Outer Ring OSLO Locations for Braidwood Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 15 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 N

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1 2

3 5

IIMciMllt:lf*-*t::::=111 **=:=II Miles llrairlwood Station

ll,IU Cou:rty t tfh! t<<l O:*i':,:rl'E

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P-I.ATI:i'?!OCD S,ATI::,t-1 FIGURE* l-3 HKJKHlO~f ANt V-/,;., TFRJX)RNF. FXF'((f)RF.

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)( M:lk Figure 4, Ingestions and Waterborne Exposure Pathway Sample Locations of Braidwood Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 16 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 7.0 REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES Table 6, Reporting Levels for Radioactivity Concentrations in Environmental Samples Water Air Particulates Fish (pCi/kg-Food Radionuclide or Gases Milk (pCi/L)

Products (pCi/L)

(pCi/m3) wet)

(pCi/Kg-wet)

H-3 20,000 (1)

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

100 Cs-134 30 10 1,000 60 1,000 Cs-137 50 20 2,000 70 2,000 Ba-La-140 200 NA NA 300 NA Table 7, Maximum Values for the Limit of Detection Water Air Particulates Fish Milk Food Products Sediment Radionuclide or Gases (pCi/L)

(pCi/m3)

(pCi/kg-wet)

(pCi/L)

(pCi/Kg-wet)

(pCi/Kg-dry)

Gross Beta 4

0.01 NA NA NA H-3 2,000 NA NA NA NA Mn-54 15 NA 130 NA NA Fe-59 30 NA 260 NA NA Co-58, Co-60 15 NA 130 NA NA Zn-65 30 NA 260 NA NA Zr-Nb-95 15 NA NA NA NA 1-131 1 (3) 0.07 NA 1

60 Cs-134 15 0.05 130 15 60 Cs-137 18 0.06 150 18 80 Ba-140 60 NA NA 60 NA La-140 15 NA NA 15 NA 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/1 may be used 3 If no drinking water pathway exists, a value of 15 pCi/I may be used NA NA NA NA NA NA NA NA 150 180 NA NA

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 17 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 8.0 SAMPLING PROGRAM, PROGRAM MODIFICATION AND INTEPRETATION OF RESULTS 8.1 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. Results from samples collected and analyzed during the year, 2024, are described below.

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.

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 (MOD), 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. MOD 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 46 locations were monitored and data., Environmental Direct Radiation Dosimetry Results, provides the annual direct radiation dosimetry analysis.

All OSLO measurements had a range of 11.2 to 64 mrem/std. quarter. A comparison of the Inner Ring, Outer Ring and Other data to the Control Location data, indicate that the ambient gamma radiation levels from all locations were similar.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 18 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 8.2 Air Particulate and Radioiodine Sample Results Air particulate filters and charcoal canisters were collected from locations specified in Table 2, Radiological Environmental Sampling Program - Exposure Pathway -

Airborne. During the calendar year 2024, a total of 424 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. Naturally occurring beryllium-? was detected on all the control and indicator samples at concentrations consistent with previous years Radioiodine (1-131) analysis is performed weekly on radioiodine sample cartridges.

All air particulate and radioiodine samples were below detection limit and were at levels consistent with previous years. All air particulate quarterly gamma composite samples were below the detection limit except for naturally occurring radionuclides.

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M w 25.0 20.0 15.0 10.0 5.0 0.0 Air Particulate: Analysis for Gross Beta, Indicator vs. Control 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Year

Indicator.....,.,..Control Figure 5, Air Particulate: Analysis for Gross Beta, Average for All Indicator 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 I YEAR: 2024 I

Page 19 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 8.3 8.3.1 Waterborne Sample Results 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 72 surface water samples were collected and analyzed in accordance with the requirements in the ODCM and shown in Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne. Gross Beta was detected in 63 of the 72 samples with a range of 2 to 13 pCi/L. The required LLD for gross beta was met for all samples. Samples from all locations were analyzed for gamma-emitting nuclides. No nuclides were detected and all required LLDs were met.

Tritium was detected in two samples with concentrations ranging from 485 to 738 pCi/L(Table 20, Quarterly Surface Water Tritium (pCi/L +/- 2 Sigma)). Tritium concentrations in surface water were well below the EPA tritium drinking water limit of 20,000 pCi/L and were consistent with expected levels as a result of permitted liquid discharges.

1400

i' 1200

~ 1000

-2:'

800 0

600

<(

E 400

J

+-'

~ 200 0

Surface Water Tritium Data 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Year

There are no detected tritium results for 8D-25(Control). If there are detectable results in the future, it will be added to the graph.

Figure 6: Surface Water Tritium Results

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 20 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 8.3.2 REMP Groundwater Groundwater samples were collected from control location upgradient from the plant and indicator location down gradient from the plant. During the calendar year 2024, a total of 32 groundwater water samples were collected from offsite monitoring wells and analyzed in accordance with the requirements in the ODCM and shown in Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne.

A total of 8 indicator samples were collected. These samples were analyzed for tritium and gamma quarterly. All samples were collected in new unused plastic bottles, which were rinsed with source water prior to collection.

Samples from all locations were analyzed for gamma-emitting nuclides. No nuclides were detected and all required LLDs were met. There has been no detectable tritium in any REMP groundwater samples in 2024 or the previous 10 years, therefore, no trend has been established above the detection limit to plot on a trending graph.

8.3.3 Public Water A total of 12 public water samples were obtained in 2024. Monthly composites of weekly samples were analyzed for gross beta, gamma-emitting nuclides, tritium, lodine-131 (Low Level), lron-55, and Nickel-63 monthly in accordance with requirements in the ODCM and shown in Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne. Gross Beta was detected in 9 out of the 12 samples with concentrations ranging from 3 to 6 pCi/L. No gamma-emitting nuclides were detected and all required LLDs were met. lron-55 and Nickel-63 was not detected and all required LLDs were met. lodine-131(Low Level) was not detected in any of the samples and all required LLDs were met. Tritium was detected in 11 out of the 12 samples with concentrations ranging from 271 to 1,350 pCi/L.

Tritium concentrations in public water were well below the EPA tritium drinking water limit of 20,000 pCi/L.

u

<(

ru

!:fl 0

0 4.5 4.0 3,5 3.0 2.5 2.0 1.5 1.0 0.5 0,0 Public Water Gross Beta 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Year

-.,..BD-22 Figure 7: Public Water Gross Beta Sample Indicator Comparison

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 21 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2

~

C5 20000.0

a. c

't5

<(

E 2000.0 200.0 b

Tritium Data 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024

.....,._BD-22 EPA Limit Figure 8: Public Water Tritium Sample Results 8.3.4 Sediment from Shoreline 8.4 8.4.1 Shoreline sediment collections were made in May and October, 2024 and analyzed for gamma-emitting isotopes, lron-55, and Nickel-63. Samples are collected at both indicator and control locations. A total of 6 (2 from the control location and 4 from the indicator locations) shoreline samples were analyzed in accordance with requirements in the ODCM and shown in Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne. Cesium-137 was detected in 1 of the 2 control sam pies at a concentration of 121 pCi/kg Dry. No other fission or activation products were found, and all required LLDs were met.

It is common to detect Cesium-137 in sediment samples at both indicator and control locations. Cesium-137 can be attributed to offsite sources such as weapons testing, Chernobyl, and Fukushima events. While Cs-137 is periodically found in sediment samples, the historical relationship between the indicator and control locations demonstrate that the plant is not the source of activity detected.

Ingestion Pathway Sample Results Goat Milk Milk samples from milking animals were collected at one location collected from an indicator location approximately 10 km that would have the highest dose potential.

Samples were analyzed for gamma-emitting isotopes and lodine-131(Low Level).

Vegetation collected, in 2024, were used as control samples in lieu of a control milk location.

No nuclides potentially associated with Braidwood Station were detected, and all required LLDs were met.

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 22 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 8.4.2 Fish A total of 12 fish samples were collected in 2024. These samples were analyzed for gamma-emitting radionuclides, lron-55, and Nickel-63 in edible portions, in accordance with requirements of the ODCM and summarized in Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion. These samples are collected from the indicator and control areas as required by the ODCM.

No fission or activation products were detected and all required LLDs were met. lron-55 and Nickel-63 were not detected, and all required LLDs were met.

8.4.3 Vegetation A total of 109 food product-type samples were analyzed in 2024 for gamma-emitting radionuclides in accordance with requirements of the ODCM, as summarized in Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion No fission or activation products were detected, and all required LLDs were met.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 23 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 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 [2]. NUREG-1301/1302 Control 3.12.2 specifies that "a Land Use Census shall be conducted and shall identify within a distance of 10 km (6.2 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-1301/1302, 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 8 miles. In summary, the highest D/Q locations for nearest livestock and nearest residence did not change following the 2024 census.

The Land Use Census included the addition of a new milk animal location located 6.2 miles away from the station. All other locations stayed the same.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 24 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 I

Table 8: Land Use Census - Nearest Receptors within 8 miles I

Sector Direction Nearest Residence Distance Nearest Milk Distance Livestock Distance (Miles)

Animal (Miles)

(Miles) 34800 Route 129, 0.3 Lestina, 1360 Division A

N miles from corner of 0.5 Street, Division and Rt.

2.6 Division and Rt.129 133 B

NNE 470 S. Washington 0.9 Street, Braidwood Hank Tameling, 34940 C

NE S. Center, Next to 0.7 station property D

ENE 34740 S. Center 0.6 Street, Braidwood 35047 Cemetery Mark Favero, 23538 E

E Road, Braidwood, NE 1.5 Smiley Road, north side 2.3 corner of Cemetery of Smiley Rd.; just east and Smiley Rd.

of Essex Rd.

Ralph Morris, 35515 James Hefner, 36718 F

ESE Essex Rd., 1"1 house 2.2 Essex Road; westside, 2.3 south of Smiley, east at McGuire Rd.

side of Essex James Hefner, 36718 E. Foley, Essex Rd.

G SE Essex Road, corner of 2.7 2.7 Cooper and Essex South of Cooper Rd.

Willis, 16700 6000N, H

SSE across from South 4.5 Wilmington Sportsmen's Club Richard Woodcock, J

s south of 5000N on 4.2 19000W, east side of road Joyce, 7550 E. Rice K

SSW 4715 S. Kankakee Rd, 1.3 Road, S. Wilmington; 5.3 Braceville north side of Rice just west of creek Larry Zin, 784 Rose L

SW Lane, End of Rose 0.4 Lane Terri Case-Hughes, M

WSW 784 Mesa, WSW side 0.5 of station property line Biros Dairy Farm, Don Francois, 3245 S.

Dean Nove, 785 Elmo Reed Road and Rt.

Berta Road, Braceville; N

w Court, west side of 0.4 47; east on Reed 8.7 1 mile north of 1.6 station property fence 1.2 miles; farm on Braceville Rd. on west north side of road side of Berta Casey Hansel, 490 p

WNW Vernon Street, east of 0.4 Rt. 53 on Vernon Gary Basham, 35020 Q

NW S. Rt. 129, west of L-0.4 19 on Rt. 129 Edward Carlo, 34908 8270 Duck Pond 8270 Duck Pond Rd, R

NNW S. State Road 129, 0.4 Rd, Coal City, IL 6.2 Coal City, IL 60416 6.2 west side of Rt. 129 60416

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 25 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 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 as 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).

"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 Collection Reason for not conducting REMP Sample Type Location Date or Period sampling as required by ODCM No sample was collected due to Ground Water BD-50 01/11/25 external water being turned off.

Residents were absent.

Surface Water BD-25 01/18/2024 No sample. The area was inaccessible due to the river being frozen.

Surface Water BD-38 01/18/2024 No sample due to the lake being frozen.

Surface Water BD-55 01/18/2024 No sample due to the pond being frozen.

Surface Water BD-56 01/18/2024 No sample due to the pond being frozen Surface Water BD-25 01/25/2024 No sample. The area was inaccessible due to the river being frozen.

Surface Water BD-25 02/01/2024 No sample. The area was inaccessible due to flooding Surface Water BD-25 02/08/2024 No sample. The area was inaccessible due to flooding Surface Water BD-25 04/04/2024 No sample. The area was inaccessible due to flooding Surface Water BD-25 04/11/2024 No sample. The area was inaccessible due to flooding Surface Water BD-25 04/18/2024 No sample. The area was inaccessible due to flooding Plans for preventing reoccurrence Sample was collected at a later time.

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 26 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 9: Sample Deviation Summary Cont'd Collection Reason for not conducting REMP Plans for preventing Sample Type Location Date or Period sampling as required by ODCM reoccurrence Timer indicates 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months less than AP/Al BD-05 04/25/2024 expected due to a short power outage.

During collection, the timer indicated an expected value of 160.2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

Timer indicates approximately 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months less than expected, possibly due to a The timer was AP/Al BD-05 05/23/2024 power outage. During collection, the exchanged and run time timer indicated a low value of 86.1 was calculated hours.

Ground Water MW-11 2nd Quarter No sample was collected. Not enough 2024 water was present.

Timer indicates approximately 35.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months less than expected due to a AP/Al BD-02 07/17/2024 power outage caused by severe storms in the area. During the collection, the timer indicated an expected value of 190.6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Timer indicates approximately 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months less than expected due to a power AP/Al BD-03 07/17/2024 outage caused by severe storms in the area. During the collection, the timer indicated an expected value of 191.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months .

Surface Water BD-25 07/17/2024 No sample. The area was inaccessible due to flooding Surface Water BD-38 09/19/2024 No sample. This was due to the area being dried up.

The timer shows approximately 20 The timer was AP/Al BD-06 10/31/2024 hours less than expected, possibly due exchanged to a faulty timer.

The timer shows lower readings of 105.0 hours0 days 0 hours 0 weeks 0 months possibly due to a broken The timer was AP/Al BD-06 11/07/2024 timer. During the collection, the timer exchanged, and the run indicated an expected value of 169.1 time was calculated.

hours.

Surface Water BD-10 12/05/2024 No sample. The area was inaccessible due to the river being frozen.

Surface Water BD-25 12/05/2024 No sample. The area was inaccessible due to the river being frozen.

Surface Water BD-56 12/05/2024 No sample due to the pond being frozen Surface Water BD-10 12/12/2024 No sample. The area was inaccessible due to the river being frozen.

Surface Water BD-25 12/12/2024 No sample. The area was inaccessible due to the river being frozen.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 27 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 11.0 11.1 11.2 Table 9: Sample Deviation Summary Cont'd Collection Reason for not conducting REMP Plans for preventing Sample Type Location Date or Period sampling as required by ODCM reoccurrence Surface Water BD-56 12/12/2024 No sample due to the pond being frozen Surface Water BD-56 12/19/2024 No sample due to the pond being frozen Ground Water MW-6 4th Quarter No sample collected. Not enough water 2024 present.

OTHER SUPPLEMENTAL INFORMATION NEI 07-07 Onsite Radiological Groundwater Monitoring Program Braidwood Station Units 1 and 2 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, samples and results taken in support of NEI 07-07 on-site groundwater monitoring program are separate from the Radiological Environmental Monitoring Program (REMP).

Results of the NEI 07-07 Radiological Groundwater Monitoring Program(RGPP) for onsite groundwater wells are provided in the RGPP report attached to the end of this document.

Corrections to Previous Reports There were no corrections to the previous report in 2024.

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 28 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 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, 197 4.

[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] "NRG 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 Initiative-Final Guidance Document,"," Nuclear Energy Institute, Washington, D.C..

Annual Radiological Environmental Operating Report

[ YEAR: 2024 [

Page 29 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2

[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 Initiative-Final 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.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 30 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2, Data Table Summary Table 10: Braidwood Data Summa_ry Table Type, Total Number Lower Indicator Location with Highest Annual Number of Medium or Pathway of Analyses Limit of Means; Mean Control Non routine Sampled (Units) performed Detection (f6).

Name Mean5 Means (f6).

Reported (e.g., 1-131, 400)

(LLD)

Ranges Distance and (f6)

Ranges Measurements Direction Ranges BD-05 Gross Beta, 424 10 18 (371/371)

Gardner 19 (53/53) 18 (53/53) 0 (7/36) 5.5 miles SW (9/36)

(6/35)

Mn-54 N/A

< LLD

< LLD 0

Co-58 N/A

< LLD

< LLD 0

Fe-59 N/A

< LLD

< LLD 0

Air Particulates Co-60 N/A

< LLD

< LLD 0

(E-03 pCi/m3)

Zn-65 N/A

< LLD

< LLD 0

Gamma, Nb-95 N/A

< LLD

< LLD 0

32 Zr-95 N/A

< LLD

< LLD 0

Cs-134 50

< LLD

< LLD 0

Cs-137 60

< LLD

< LLD 0

Ba-140 N/A

< LLD

< LLD 0

La-140 N/A

< LLD

< LLD 0

Airborne Radioiodine 1-131,424 70

< LLD

< LLD N/A 0

(E-03 pCi/m3) 17 (180/180)

BD-ISFSl-110-3 62.1 (4/4) 14.9 (4/4)

Direct Radiation Gamma Dose, 184 N/A 0

(mrem/qtr.)

(11.2/64) 0.18 MILES SE (60.5/64)

(13.1/16.8) 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations, as indicated in parentheses.

Annual Radiological Environmental Operating Report LYEAR: 2024 J Page 31 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2, Data Table Summary Table 10: Braidwood Data Summary Table Indicator Location with Highest Annual Type, Total Number Lower Mean Medium or Pathway of Analyses Limit of Means; Name Sampled (Units) performed Detection (f6).

Distance Means (e.g., 1-131, 400)

(LLD)

Ranges and (f6)

Direction Ranges l-131(Low Level), 5 1

< LLD

< LLD Mn-54 N/A

< LLD

< LLD Co-58 N/A

< LLD

< LLD Fe-59 N/A

< LLD

< LLD Co-60 N/A

< LLD

< LLD Goat Milk Zn-65 N/A

< LLD

< LLD (pCi/L)

Gamma, 5 Nb-95 N/A

< LLD

< LLD Zr-95 N/A

< LLD

< LLD Cs-134 15

< LLD

< LLD Cs-137 18

< LLD

< LLD Ba-140 60

< LLD

< LLD La-140 15

< LLD

< LLD Mn-54 N/A

< LLD

< LLD Co-58 N/A

< LLD

< LLD Fe-59 N/A

< LLD

< LLD Co-60 N/A

< LLD

< LLD Zn-65 N/A

< LLD

< LLD Vegetation

Gamma, Nb-95 N/A

< LLD

< LLD (pCi/kg-wet) 109 Zr-95 N/A

< LLD

< LLD 1-131 60

< LLD

< LLD Cs-134 60

< LLD

< LLD Cs-137 80

< LLD

< LLD Ba-140 N/A

< LLD

< LLD La-140 N/A

< LLD

< LLD 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations, as indicated in parentheses.

Control Means (f6).

Ranges N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

< LLD

< LLD Number of Non routine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 32 of 81 Company: Constellati_<>n

[ Plant: Braidwood Station Units 1 and 2, Data Table Summary Table 10: Braidwood Data Summary Table Indicator Location with Highest Annual Type, Total Number Lower Mean Medium or Pathway of Analyses Limit of Means; Name Means Sampled (Units) performed Detection (f6).

Distance (f6)

(e.g., 1-131, 400)

(LLD)

Ranges and Ranges Direction BD-40 Braidwood Gross Beta, 72 4

6.4 (52/60)

Station 9.8 (12/12)

Cooling Lake (2.4/13.4)

Onsite (3.2/13.4)

BD-10 Kankakee H-3, 24 200 612 (2/20)

River 612 (2/4)

Downstream (485/738) 5.4 miles NE (485/738)

Fe-55, 24 200

< LLD

< LLD Surface Water (pCi/L)

Ni-63, 24 30

< LLD

< LLD Mn-54 15

< LLD

< LLD Co-58 15

< LLD

< LLD Fe-59 30

< LLD

< LLD Co-60 15

< LLD

< LLD Zn-65 30

< LLD

< LLD Gamma, 72 Nb-95 15

< LLD

< LLD Zr-95 30

< LLD

< LLD 1-131 15

< LLD

< LLD Cs-134 15

< LLD

< LLD Cs-137 18

< LLD

< LLD Ba-140 60

< LLD

< LLD La-140 15

< LLD

< LLD 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations is indicated in parentheses.

Control Means (f6).

Ranges 4.8 (11/12)

(3.2/7)

< LLD

< LLD Number of Non routine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report j -YEAR: 2024 \

Page 33 of 81 Com~nyScmstellation J Plant: Braidwood Station Units 1 and 2 Type, Total Number Medium or of Analyses Pathway Sampled (Units) performed (e.g., 1-131, 400)

Gross Beta, 12 H-3, 12 1-131 (Low Level), 12 Fe-55, 12 Public Water Ni-63, 12 (pCi/L)

Mn-54 Co-58 Fe-59 Co-60 Zn-65

Gamma, Nb-95 12 Zr-95 Cs-134 Cs-137 Ba-140 La-140, Data Table Summary Table 10: Braidwood Data Summary Table Indicator Location with Highest Annual Lower Mean Limit of Means; Name Means Detection (f6).

Distance (f6)

(LLD)

Ranges and Ranges Direction BD-22 4

4.1 (9/12)

Wilmington 4.1 (9/12)

(2.9/5.9) 6.0 miles NE (2.9/5.9)

BD-22 200 860 (11/12)

Wilmington 860 (11/12)

(271/1350) 6.0 miles NE (271/1350) 1

< LLD

< LLD 200

< LLD

< LLD 30

< LLD

< LLD 15

< LLD

< LLD 15

< LLD

< LLD 30

< LLD

< LLD 15

< LLD

< LLD 30

< LLD

< LLD 15

< LLD

< LLD 30

< LLD

< LLD 15

< LLD

< LLD 18

< LLD

< LLD 60

< LLD

< LLD 15

< LLD

< LLD 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations, as indicated in parentheses.

Control Means (f6).

Ranges N/A N/A N/A

< LLD

< LLD Number of Nonroutine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 34 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2, Data Table Summary Table 10: Braidwood Data Summary Table Indicator Location with Highest Annual Type, Total Number Lower Medium or Pathway of Analyses Limit of Means; Name Sampled (Units) performed Detection (f6).

Distance (e.g., 1-131, 400)

(LLD)

Ranges and Direction H-3,32 200

< LLD

< LLD Mn-54 15

< LLD

< LLD Co-58 15

< LLD

< LLD Fe-59 30

< LLD

< LLD Ground Water Co-60 15

< LLD

< LLD (pCi/L)

Zn-65 30

< LLD

< LLD Nb-95 15

< LLD

< LLD Gamma, 32 Zr-95 30

< LLD

< LLD 1-131 15

< LLD

< LLD Cs-134 15

< LLD

< LLD Cs-137 18

< LLD

< LLD Ba-140 60

< LLD

< LLD La-140 15

< LLD

< LLD 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations, as indicated in parentheses.

is indicated in parentheses Mean Means (f6)

Ranges

< LLD

< LLD Control Means (f6).

Ranges N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Number of Nonroutine Reported Measurements 0

0 0

Annual Radiological Environmental Operating Report

\ YEAR: 202i \

Page 35 of 81 Company: Constellation

. J Plant: Braidwood Station Units 1 and 2, Data Table Summary Table 10: Braidwood Data Summary Table Location with Highest Annual Type, Total Number Lower Indicator Mean Medium or Pathway of Analyses Limit of Means; Name Sampled (Units) performed Detection (f6).

Distance Means (e.g., 1-131, 400)

(LLD)

Ranges and (f6)

Direction Range5 Fe-55, 12 260

< LLD

< LLD Ni-63, 12 260

< LLD

< LLD Mn-54 130

< LLD

< LLD Co-58 130

< LLD

< LLD Fe-59 260

< LLD

< LLD Fish (pCi/kg Wet)

Co-60 130

< LLD

< LLD Zn-65 260

< LLD

< LLD Gamma, 12 Nb-95 N/A

< LLD

< LLD Zr-95 N/A

< LLD

< LLD Cs-134 130

< LLD

< LLD Cs-137 150

< LLD

< LLD Ba-140 N/A

< LLD

< LLD La-140 N/A

< LLD

< LLD 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations, as indicated in parentheses.

Control Means (f6).

Ranges

< LLD

< LLD Number of Nonroutine Reported Measurements 0

0 0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 36 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2, Data Table Summary Table 10: Braidwood Data Summary Table Indicator Location with Highest Annual Type, Total Number Lower Mean Medium or Pathway of Analyses Limit of Means; Sampled (Units) performed Detection (f6).

Name Means (e.g., 1-131, 400)

(LLD)

Distance (t6)

Ranges and Direction Range5 Fe-55, 6 260

< LLD

< LLD Ni-63, 6 260

< LLD

< LLD Mn-54 N/A

< LLD

< LLD Co-58 N/A

< LLD

< LLD Fe-59 N/A

< LLD

< LLD Co-60 N/A

< LLD

< LLD Sediment (pCi/kg Zn-65 N/A

< LLD

< LLD Dry)

Nb-95 N/A

< LLD

< LLD Zr-95 N/A

< LLD

< LLD Gamma, 6 Cs-134 150

< LLD

< LLD BD-25 Kankakee Cs-137 180

< LLD River 121 (1/2)

Upstream 9.6 miles Ba-140 N/A

< LLD

< LLD La-140 N/A

< LLD

< LLD 5 Mean and range are based on detectable measurements only.

6 Fraction are based on detectable measurements at specified locations, as indicated in parentheses.

Control Means (t6).

Ranges

< LLD

< LLD 121 (1/2)

< LLD

< LLD Number of Non routine Reported Measurements 0

0 0

Collection Date 12/28/2023 01/04/2024 01/11/2024 01/18/2024 01/25/2024 02/01/2024 02/08/2024 02/15/2024 02/22/2024 02/28/2024 03/07/2024 03/14/2024 03/21/2024 03/28/2024 04/04/2024 04/11/2024 04/18/2024 04/25/2024 05/02/2024 05/09/2024 05/16/2024 Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 37 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2 BD-06 18

+/-

18

+/-

26

+/-

17

+/-

15

+/-

10

+/-

19

+/-

23

+/-

20

+/-

11

+/-

19

+/-

11

+/-

16

+/-

9

+/-

10

+/-

11

+/-

11

+/-

15

+/-

13

+/-

11

+/-

17

+/-, Complete Data Table for All Analysis Results Obtained in 2024 Note: Throughout Attachment 2, bold data entries are for the reported concentration Table 11, Weekly Air Particulate Gross Beta (E-3 pCi/m3)

BD-19 BD-20 BD-21 BD-02 BD-04 BD-05 4

12

+/-

4 16

+/-

4 17

+/-

4 12

+/-

4 16

+/-

4 16

+/-

5 15

+/-

4 19

+/-

5 20

+/-

5 22

+/-

5 22

+/-

5 21

+/-

5 25

+/-

5 26

+/-

5 28

+/-

5 21

+/-

4 29

+/-

5 20

+/-

4 18

+/-

4 12

+/-

4 19

+/-

4 15

+/-

4 17

+/-

4 15

+/-

4 14

+/-

4 13

+/-

4 19

+/-

4 10

+/-

4 15

+/-

4 18

+/-

4 16

+/-

4 13

+/-

4 13

+/-

4 11

+/-

4 15

+/-

4 12

+/-

4 16

+/-

4 17

+/-

4 16

+/-

4 14

+/-

4 19

+/-

4 18

+/-

5 23

+/-

5 23

+/-

5 22

+/-

5 16

+/-

4 19

+/-

4 23

+/-

5 21

+/-

5 24

+/-

5 22

+/-

5 19

+/-

5 36

+/-

6 21

+/-

4 14

+/-

4 12

+/-

4 14

+/-

4 13

+/-

4 13

+/-

4 14

+/-

4 25

+/-

4 19

+/-

4 17

+/-

4 17

+/-

4 20

+/-

4 17

+/-

4 10

+/-

4 12

+/-

4 11

+/-

4 9

+/-

4 8

+/-

3 12

+/-

4 16

+/-

4 13

+/-

4 17

+/-

4 14

+/-

4 13

+/-

4 15

+/-

4 10

+/-

4 8

+/-

4 8

+/-

4 10

+/-

4 13

+/-

4 9

+/-

4 8

+/-

4 13

+/-

4 10

+/-

4 10

+/-

4 9

+/-

4 10

+/-

4 13

+/-

4 14

+/-

4 17

+/-

4 11

+/-

4 14

+/-

4 17

+/-

4 13

+/-

4 13

+/-

4 15

+/-

4 10

+/-

4 11

+/-

4 17

+/-

4 15

+/-

4 14

+/-

4 14

+/-

4 14

+/-

4 11

+/-

4 15

+/-

4 14

+/-

4 14

+/-

4 15

+/-

4 12

+/-

3 13

+/-

4 15

+/-

4 15

+/-

4 12

+/-

4 14

+/-

4 10

+/-

4 11

+/-

4 11

+/-

4 17

+/-

4 17

+/-

4 17

+/-

4 13

+/-

4 21

+/-

4 19

+/-

4 5

4 4

4 5

5 4

4 4

4 BD-03 13

+/-

4 16

+/-

4 28

+/-

5 17

+/-

4 15

+/-

4 11

+/-

4 14

+/-

4 20

+/-

5 21

+/-

5 14

+/-

4 17

+/-

4 11

+/-

4 14

+/-

4 6

+/-

4 11

+/-

4 14

+/-

4 19

+/-

5 16

+/-

4 17

+/-

4 11

+/-

4 18

+/-

4

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 38 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 11, Weekly Air Particulate Gross Beta (E-3 pCi/m3) Cont'd Collection BD-06 BD-19 BD-20 BD-21 BD-02 BD-04 BD-05 BD-03 Date 05/23/2024 10

+/-

4 11

+/-

4 12

+/-

4 12

+/-

4 7

+/-

3 14

+/-

4 11

+/-

4 11

+/-

4 05/30/2024 15

+/-

4 15

+/-

4 15

+/-

4 12

+/-

4 11

+/-

4 17

+/-

4 12

+/-

4 17

+/-

5 06/06/2024 15

+/-

4 10

+/-

4 12

+/-

4 14

+/-

4 10

+/-

4 16

+/-

4 13

+/-

4 13

+/-

4 06/13/2024 18

+/-

4 19

+/-

4 16

+/-

4 17

+/-

4 15

+/-

4 16

+/-

4 17

+/-

4 19

+/-

4 06/20/2024 13

+/-

4 15

+/-

4 14

+/-

4 15

+/-

4 11

+/-

4 15

+/-

4 12

+/-

4 11

+/-

4 06/27/2024 13

+/-

5 13

+/-

5 11

+/-

4 11

+/-

4 11

+/-

4 14

+/-

5 14

+/-

4 17

+/-

5 07/03/2024 22

+/-

4 16

+/-

4 17

+/-

4 18

+/-

4 15

+/-

4 19

+/-

4 17

+/-

4 19

+/-

4 07/11/2024 17

+/-

4 18

+/-

4 18

+/-

4 21

+/-

5 13

+/-

5 19

+/-

4 15

+/-

4 15

+/-

5 07/17/2024 15

+/-

4 17

+/-

4 14

+/-

4 14

+/-

4 9

+/-

3 16

+/-

4 14

+/-

4 13

+/-

4 07/25/2024 16

+/-

4 18

+/-

4 19

+/-

4 18

+/-

4 15

+/-

4 20

+/-

4 17

+/-

4 18

+/-

4 08/01/2024 22

+/-

4 21

+/-

4 21

+/-

4 21

+/-

4 23

+/-

5 18

+/-

4 23

+/-

4 16

+/-

4 08/08/2024 18

+/-

4 20

+/-

4 18

+/-

4 23

+/-

5 12

+/-

4 18

+/-

4 21

+/-

5 19

+/-

4 08/15/2024 17

+/-

4 16

+/-

4 14

+/-

4 17

+/-

4 13

+/-

4 16

+/-

4 15

+/-

4 15

+/-

4 08/22/2024 30

+/-

5 28

+/-

5 24

+/-

5 27

+/-

5 24

+/-

5 24

+/-

5 26

+/-

5 25

+/-

5 08/29/2024 17

+/-

4 12

+/-

4 19

+/-

4 18

+/-

5 14

+/-

4 15

+/-

4 17

+/-

5 12

+/-

4 09/05/2024 27

+/-

4 26

+/-

4 25

+/-

4 27

+/-

4 22

+/-

4 27

+/-

4 29

+/-

4 28

+/-

4 09/13/2024 33

+/-

6 33

+/-

6 29

+/-

5 30

+/-

5 27

+/-

5 31

+/-

6 32

+/-

6 35

+/-

6 09/19/2024 20

+/-

5 22

+/-

5 22

+/-

5 24

+/-

5 17

+/-

4 21

+/-

5 24

+/-

5 18

+/-

4 09/26/2024 17

+/-

4 19

+/-

4 20

+/-

4 22

+/-

5 15

+/-

4 17

+/-

4 24

+/-

5 20

+/-

5 10/03/2024 28

+/-

5 30

+/-

5 31

+/-

5 24

+/-

5 22

+/-

5 30

+/-

5 28

+/-

5 24

+/-

5 10/10/2024 23

+/-

4 23

+/-

4 18

+/-

4 24

+/-

5 18

+/-

4 23

+/-

4 23

+/-

5 19

+/-

4 10/17/2024 26

+/-

5 31

+/-

5 29

+/-

5 29

+/-

5 24

+/-

5 31

+/-

5 29

+/-

5 29

+/-

5

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 39 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2 Table 11, Weekly Air Particulate Gross Beta (E-3 pCi/m3) Cont'd Collection BD-06 BD-19 BD-20 BD-21 BD-02 BD-04 BD-05 BD-03 Date 10/24/2024 26

+/-

5 29

+/-

5 25

+/-

5 25

+/-

5 27

+/-

5 30

+/-

5 36

+/-

6 25

+/-

5 10/31/2024 13

+/-

4 14

+/-

4 10

+/-

4 14

+/-

4 13

+/-

4 12

+/-

4 15

+/-

4 14

+/-

4 11/07/2024 21

+/-

4 23

+/-

4 20

+/-

4 23

+/-

5 20

+/-

4 22

+/-

4 22

+/-

4 22

+/-

4 11/14/2024 25

+/-

5 24

+/-

5 24

+/-

4 26

+/-

5 22

+/-

5 22

+/-

5 28

+/-

5 22

+/-

5 11/21/2024 20

+/-

5 22

+/-

5 17

+/-

5 17

+/-

5 18

+/-

5 17

+/-

5 23

+/-

5 17

+/-

5 11/27/2024 24

+/-

4 28

+/-

4 27

+/-

4 25

+/-

4 28

+/-

4 28

+/-

4 27

+/-

4 26

+/-

4 12/05/2024 20

+/-

4 18

+/-

4 21

+/-

4 20

+/-

4 20

+/-

4 22

+/-

5 21

+/-

5 17

+/-

4 12/12/2024 24

+/-

5 31

+/-

5 27

+/-

5 33

+/-

5 28

+/-

5 31

+/-

5 34

+/-

5 30

+/-

5 12/19/2024 18

+/-

4 15

+/-

4 19

+/-

4 20

+/-

5 20

+/-

4 22

+/-

5 20

+/-

5 22

+/-

4 12/26/2024 31

+/-

5 35

+/-

5 28

+/-

5 32

+/-

5 27

+/-

5 29

+/-

5 32

+/-

5 29

+/-

5

Annual Radiological Environmental Operating Report I YEAR: 2024 1 Page 40 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 12: Quarterly Air Particulate Gamma Isotopic (pCi/m3 +/- 2 Sigma)

Station Nuclide Q1 Q2 Q3 Q4 Station Nuclide Q1 Q2 Q3 Q4 Mn-54 2

3 3

2 Mn-54 2

2 1

1 Co-58 2

3 3

2 Co-58 1

2 2

1 Fe-59 5

7 8

4 Fe-59

< 4 6

6 5

Co-60 3

2 3

2 Co-60 3

2 2

2 Zn-65 5

6 7

6 Zn-65 3

4 6

4 BD-06 Nb-95 2

3 3

2 BD-20 Nb-95 2

3 3

2 Zr-95 4

6 6

3 Zr-95 2

4 5

3 Cs-134 2

3 3

2 Cs-134 1

3 2

1 Cs-137 2

2 2

2 Cs-137 1

2 1

2 Ba-140 11 34 30 19 Ba-140 10 28 46 16 La-140 5

15 17 9

La-140 4

10

< 7 7

Mn-54 2

4 3

2 Mn-54 1

2 2

2 Co-58 2

4 3

2 Co-58 1

2 3

3 Fe-59 4

10 9

5 Fe-59 3

7 7

7 Co-60 2

4 4

3 Co-60 2

3 2

3 Zn-65 3

8 6

5 Zn-65 1

4 7

6 BD-19 Nb-95 2

< 4 3

2 BD-21 Nb-95 2

3 3

2 Zr-95 3

7 6

5 Zr-95 2

4 6

4 Cs-134 2

3 3

2 Cs-134 2

2 3

2 Cs-137 2

3 3

2 Cs-137 1

3 3

2 Ba-140 9

42 49 18 Ba-140 10 34 42 19 La-140 3

16 21 7

La-140 3

15 16 6

Annual Radiological Environmental Operating Report I YEAR: 2024 1 Page 41 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 12: Quarterly Air Particulate Gamma Isotopic (pCi/m3 +/- 2 Sigma) Cont'd Station Nuclide Q1 Q2 Q3 Q4 Station Nuclide Q1 Q2 Q3 Q4 Mn-54 1

2 2

2 Mn-54 1

2 4

2 Co-58 2

2 2

2 Co-58 1

3 5

3 Fe-59 2

6 6

6 Fe-59 3

6 14 6

Co-60 2

1 3

3 Co-60 2

2 5

3 Zn-65 5

5 4

4 Zn-65 4

5 12 7

BD-02 Nb-95 2

2 2

2 BD-05 Nb-95 1

3 6

3 Zr-95 3

4 4

3 Zr-95 2

4 9

6 Cs-134 2

2 2

2 Cs-134 1

2 4

3 Cs-137 2

1 2

2 Cs-137 1

2 3

3 Ba-140 8

29 31 19 Ba-140 7

23 70 30 La-140 7

14 15 9

La-140 4

13 39 10 Mn-54 2

2 2

1 Mn-54 3

4 4

2 Co-58 2

3 3

2 Co-58 2

5 4

2 Fe-59 3

7 7

4 Fe-59 6

12 9

6 Co-60 2

3 1

2 Co-60 3

6 4

3 Zn-65 3

7 4

5 Zn-65 6

10 8

5 BD-04 Nb-95 1

3 2

2 BD-03 Nb-95 2

6 4

3 Zr-95 3

6 5

3 Zr-95 6

9 7

5 Cs-134 1

3 3

2 Cs-134 2

4 4

2 Cs-137 1

2 2

2 Cs-137 2

4 3

3 Ba-140 7

35 35 14 Ba-140 15 55 61 24 La-140 15 15 13 8

La-140 6

17 21 10

Annual Radiological Environmental Operating Report iY'EAR: 2024 ]

Page 42 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3)

Collection BD-06 BD-19 BD-20 BD-21 BD-02 BD-04 BD-05 BD-03 Date 12/28/2023

< 35 36 37 18 44 45 41 46 01/04/2024

< 32 31 32 32

< 45 45

< 43 46 01/11/2024

< 46 46 47 47 58 58 54 59 01/18/2024

< 40

< 40 40 40 56 57 56 57 01/25/2024

< 47 48 48 48 40 38 37 40 02/01/2024

< 39 40 37 39 31 33 30 32 02/08/2024

< 38

< 38 38 38 27 26 13 26 02/15/2024

< 35 36 36 36

< 48 45

< 46 48 02/22/2024

< 43 45

< 45 48 51 50 48 51 02/28/2024

< 47 44 44 46 36 34 26 35 03/07/2024

< 40 40 39 42 41 39 16 41 03/14/2024 31 31 30 24 36 37 35 37 03/21/2024

< 22 10 11 11 11 21 22 22 03/28/2024

< 48 47

< 48 48 34 35 33 35 04/04/2024

< 34 33 33 34 32 32 31 34 04/11/2024

< 36 37 37 37 35 34 33 35 04/18/2024

< 49 48 48 49 37 35 16 35 04/25/2024

< 34 34 33 35 44 41 43 45 05/02/2024 41 40 40 40 35 35 33 36 05/09/2024

< 47 43

< 44 20 49

< 46 46 49 05/16/2024

< 36 36 34 37 31 30 30 29

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 43 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3) Cont'd Collection BD-06 BD-19 BD-20 BD-21 BO-02 BD-04 BD-05 BD-03 Date 05/23/2024

< 48

< 47

< 48

< 44 43 17 43 05/30/2024

< 43 41

< 40 41

< 37 35 37 39 06/06/2024 54 52 52 54 44 45 17 44 06/13/2024 27 28 26 28 39 38 18 39 06/20/2024 38 36 37

< 37 42 17 41 44 06/27/2024 51 50

< 49 51

< 55 55 24 56 07/03/2024 39 38

< 38

< 40

< 33 33 35 33 07/11/2024 60 60

< 59 61 32 51 49 57 07/17/2024 35 34 34 35 31 30 20 30 07/25/2024 30 29 29

< 30

< 33 32 31 33 08/01/2024 38 37 37 38 32 31 31 32 08/08/2024 48 33 47 47

< 33 33 34 32 08/15/2024 25 25 16 25 27 26 25 25 08/22/2024 35 34 35

< 35 34 34 36 33 08/29/2024 29 28 27 29 39 38 41 40 09/05/2024 26 26 25

< 26 22 22 22 21 09/13/2024 51 51 56

< 52 56 56 57 55 09/19/2024 39 37

< 38

< 38 51 50 52 49 09/26/2024 30 32 32

< 33 32 29 14 32 10/03/2024

< 40 37

< 37

< 38 41 41 42 40 10/10/2024 38 38 36

< 39 40 39 40 39 10/17/2024 32 32 32

< 34

< 45 43 46 43

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 44 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3) Cont'd Collection BD-06 BD-19 BD-20 BD-21 BD-02 BD-04 BD-05 BD-03 Date 10/24/2024

< 35

< 34

< 25

< 35

< 41

< 42

< 40 10/31/2024

< 38

< 37

< 39

< 44

< 46

< 45 11/07/2024

< 33

< 32 31 33

< 39

< 37 11/14/2024

< 36

< 35

< 37

< 42

< 43

< 42 11/21/2024

< 33 32

< 21

< 33

< 41

< 43

< 41 11/27/2024

< 39

< 40

< 37

< 40

< 34

< 33

< 35

< 33 12/05/2024

< 26

< 25 19

< 26

< 39

< 40

< 41

< 39 12/12/2024

< 53

< 50

< 53

< 52

< 51

< 53

< 52 12/19/2024

< 35 33

< 14

< 35

< 37

< 39

< 36 12/26/2024

< 32 32

< 31

< 33

< 37

< 39

< 38

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 45 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 14, Monthly/Bi-Weekly Milk 1-131 (pCi/L +/- 2 Sigma)

Collection BD-18A Date 06/14/2024

< 0.7 07/05/2024

< 0.9 08/07/2024

< 0.9 09/06/2024

< 0.8 12/06/2024

< 0.8

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 46 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2 Table 15: Monthly/Bi-Weekly Milk Gamma Isotopic (pCi/L +/- 2 Sigma)

Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 06/14/2024 10

< 13

< 25

< 13

< 25 11

< 19 11 11

< 43

< 12 07/05/2024 11

< 10

< 24

< 12

< 27 10

< 18

< 14 11

< 46 11 BD-18A 08/07/2024

< 11

< 13

< 30 10

< 27

< 12

< 19

< 12

< 10

< 59

< 10 09/06/2024

< 9

< 10

< 20

< 8

< 18

< 8

< 17

< 9

< 8

< 31

< 9 12/06/2024

< 7

< 9

< 23

< 12

< 20 10

< 15 10

< 9

< 36

< 9

Annual Radiologic~_ Envi_r_onmental Operating Report I YEAR: 2024 I

Page 47 of 81 Company: Constellation

..... J Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)

Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates CARROT 09/20/2024

< 35

< 36

< 87

< 31

< 62

< 28

< 56

< 41

< 34

< 36

< 113

< 35 COLLARD 09/20/2024

< 29

< 24

< 68

< 34

< 76

< 34

< 37

< 39

< 30

< 32

< 130

< 41 GREENS BEET 09/20/2024

< 19

< 17

< 41

< 19

< 44

< 20

< 32

< 22

< 23

< 19

< 75

< 25 LEAVES BO-CONTROL RED BEETS 09/20/2024

< 33

< 40

< 69

< 37

< 75

< 37

< 62

< 38

< 40

< 32

< 146

< 47 CARROT 10/18/2024

< 34

< 33 72

< 41

< 84

< 33 77

< 47

< 44

< 33

< 155

< 42 COLLARD 10/18/2024

< 36

< 30 81

< 22

< 84 GREENS 31

< 70

< 48

< 44

< 41

< 149

< 34 SWISS 10/18/2024

< 18

< 17

< 39

< 19

< 44 CHARD 19

< 30

< 27

< 21

< 19

< 83

< 21

Annual Radiological Environmental Operating Report J YEAR:~024 _l Page 48 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet+/- 2 Sigma) Cont'd Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates COLLARD 07/17/2024

< 30

< 32

< 67

< 38

< 85

< 30 61

< 52

< 36

< 37

< 133

< 27 GREENS MUSTARD 07/17/2024

< 24

< 56

< 26

< 70 GREENS 27

< 38

< 30

< 28

< 115

< 35 RADISH 07/17/2024

< 38

< 46

< 107

< 43

< 96

< 40

< 68

< 50

< 45

< 40

< 175

< 41 COLLARD 08/15/2024

< 33

< 41

< 95

< 29

< 74 GREENS 38

< 67

< 53

< 39

< 34

< 128

< 44 MUSTARD 08/15/2024

< 25

< 23

< 56

< 20

< 60

< 24

< 41

< 35

< 30

< 98

< 25 GREENS RADISH 08/15/2024

< 19

< 38

< 19

< 51

< 18

< 35

< 29

< 24

< 22

< 86

< 24 BD-QUAD 1 COLLARD GREENS 09/19/2024

< 30

< 32

< 65

< 26

< 67

< 29

< 56

< 51

< 31

< 35

< 160

< 44 MUSTARD 09/19/2024

< 36

< 32

< 79

< 37

< 81

< 38

< 60

< 50

< 29

< 45

< 153

< 46 GREENS RADISH 09/19/2024

< 24

< 31

< 60

< 28

< 74

< 30

< 44

< 42

< 33

< 38

< 124

< 31 COLLARD 10/17/2024

< 33

< 69

< 38

< 75

< 28

< 57

< 48

< 30

< 26

< 118

< 50 GREENS MUSTARD 10/17/2024

< 17

< 35

< 20

< 40

< 17

< 28

< 26

< 19

< 18 77

< 21 GREENS RADISH 10/17/2024

< 36

< 34

< 76 31

< 88

< 36

< 59

< 46

< 37

< 41

< 165

< 54

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 49 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet +/- 2 Sigma) Cont'd Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates ONION 07/17/2024

< 27

< 28

< 56

< 34

< 59

< 30

< 50

< 44

< 30

< 30 131

< 36 RADISH 07/17/2024

< 28 31

< 60

< 32

< 64

< 34

< 55

< 45

< 31

< 28

< 111

< 47 SWISS 07/17/2024

< 26

< 27

< 70

< 31

< 76 CHARD 30

< 43

< 41

< 29

< 25

< 124

< 41 COLLARD 08/15/2024 GREENS 25

< 22 51

< 34

< 47

< 28

< 49

< 29

< 28

< 22

< 103

< 31 RADISH 08/15/2024

< 27

< 18

< 57

< 35

< 54

< 25

< 45

< 35

< 26

< 95

< 30 BEET 08/15/2024

< 25

< 24

< 49

< 29

< 65 LEAVES 26

< 45

< 33

< 31

< 26

< 98

< 29 BO-QUAD 2 RED BEETS 08/15/2024 16

< 15

< 43

< 19

< 38

< 17

< 27

< 20

< 19

< 18

< 70

< 21 COLLARD 09/19/2024

< 28

< 28 GREENS

< 56

< 28

< 61

< 30

< 47

< 35

< 28

< 22

< 104

< 33 KALE 09/19/2024

< 33

< 28

< 70

< 37

< 95

< 31

< 49

< 45

< 37

< 32

< 144

< 44 TURNIP 09/19/2024

< 12

< 30

< 15

< 34

< 14

< 22

< 17

< 13

< 49

< 14 COLLARD 10/17/2024

< 38

< 74

< 35

< 84 GREENS 40

< 73

< 51

< 43

< 31

< 169

< 50 KALE 10/17/2024 31

< 28

< 57

< 34

< 91

< 30

< 62

< 44

< 36

< 30

< 143

< 36 RADISH 10/17/2024

< 27 31

< 47

< 38

< 68

< 28

< 63

< 41

< 29

< 26

< 135

< 36

Annual Radiological Environmental Operating Report L YEAR: 2024 J Page 50 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet+/- 2 Sigma) Cont'd Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates COLLARD 07/17/2024

< 35

< 36 72

< 38

< 83 GREENS 37

< 59

< 51

< 39

< 35

< 147

< 47 RADISH 07/17/2024

< 15

< 30

< 16

< 31

< 15

< 27

< 26

< 17

< 16

< 69

< 18 BEET 07/17/2024 LEAVES 14

< 14

< 30

< 15

< 32

< 15

< 24

< 22

< 16

< 15

< 67

< 20 RED 07/17/2024 BEETS 20

< 22

< 52

< 31

< 67

< 25

< 45

< 32

< 27

< 28

< 104

< 33 COLLARD 08/15/2024

< 32

< 69

< 36

< 83

< 39

< 68

< 48

< 38

< 36

< 140

< 38 GREENS RADISH 08/15/2024

< 20

< 19

< 38

< 22

< 39

< 19

< 30

< 25

< 20

< 18

< 79

< 27 BEET LEAVES 08/15/2024

< 27

< 30

< 56

< 36

< 52

< 33

< 48

< 40

< 37

< 31

< 141

< 56 RED 08/15/2024

< 23

< 26

< 55

< 31

< 52

< 21

< 51

< 30

< 21

< 25

< 96

< 16 BEETS BO-QUAD 3 SWISS CHARD 08/15/2024

< 36

< 35

< 69

< 26

< 64

< 35

< 50

< 44

< 30

< 144

< 43 COLLARD 09/19/2024

< 29

< 81

< 27

< 70

< 30

< 50

< 39

< 38

< 29

< 147 31 GREENS RADISH 09/19/2024

< 87

< 86

< 164

< 98

< 200

< 89

< 147

< 125

< 91

< 90

< 355

< 127 BEET 09/19/2024

< 19

< 40

< 19

< 44 LEAVES 19

< 34

< 26

< 21

< 20

< 80

< 27 RED 09/19/2024

< 28

< 31 BEETS

< 71

< 38

< 78

< 33

< 54

< 49

< 33

< 32

< 143

< 47 SWISS 09/19/2024

< 19

< 40

< 21

< 42

< 19

< 33

< 27

< 20

< 79

< 27 CHARD COLLARD 10/17/2024

< 30

< 27

< 79

< 39

< 107

< 34

< 52

< 48

< 38

< 37

< 162

< 49 GREENS RED 10/17/2024 31

< 26 BEETS

< 50

< 35

< 61

< 31

< 53

< 42

< 34

< 33

< 121

< 35

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 51 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet +/- 2 Sigma) Cont'd Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates MUSTARD 07/17/2024

< 21

< 24

< 48

< 24

< 55 GREENS 25

< 44

< 35

< 29

< 22

< 116

< 24 RADISH 07/17/2024

< 33

< 29

< 67

< 34 72

< 36

< 58

< 54

< 29

< 33

< 150

< 48 RED BEETS 07/17/2024

< 23

< 22

< 44

< 25

< 48

< 22

< 38

< 35

< 24

< 100

< 31 BEET LEAVES 07/17/2024

< 28

< 33

< 53

< 34

< 79 31

< 48

< 42

< 36

< 33

< 117

< 44 KOHLRABI 08/15/2024

< 23

< 26

< 42

< 25

< 49

< 24

< 39

< 33

< 22

< 25

< 95

< 37 MUSTARD 08/15/2024

< 14

< 27

< 16

< 29 BD-QUAD 4 GREENS

< 14

< 24

< 20

< 15

< 58

< 20 RADISH 08/15/2024

< 26

< 27

< 51

< 31

< 67

< 23

< 39

< 41

< 30

< 23

< 127

< 34 KOHLRABI 09/19/2024

< 20

< 19

< 43

< 23

< 45

< 20

< 35

< 27

< 22

< 21

< 86

< 28 RADISH 09/19/2024

< 27

< 31

< 68

< 30

< 68

< 34

< 60

< 44

< 35

< 31

< 153

< 42 BEET 09/19/2024

< 32

< 29

< 62

< 35

< 61 LEAVES 32

< 55

< 43

< 35

< 32

< 134

< 43 RED BEETS 09/19/2024

< 28

< 24

< 66

< 31

< 79

< 29

< 35

< 36

< 22

< 105

< 35 RADISH 10/17/2024

< 30

< 36

< 71

< 30

< 90

< 27

< 53

< 50

< 32

< 38

< 141

< 39

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 52 of 81 Company: Constellation Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet +/- 2 Sigma) Cont'd Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates KALE 07/11/2024

< 26

< 22

< 46

< 24

< 59

< 21

< 38

< 28

< 24

< 25

< 113

< 36 TURNIP 07/11/2024

< 24

< 21

< 54

< 25

< 45

< 25

< 44

< 29

< 21

< 28

< 86

< 29 CABBAGE 07/11/2024

< 33

< 27

< 65

< 34

< 57

< 34

< 47

< 45

< 33

< 36

< 144

< 23 KALE 07/25/2024

< 37

< 38

< 91

< 54

< 64

< 40 77

< 52

< 39

< 38

< 146

< 57 CABBAGE 07/25/2024

< 25

< 66

< 31

< 60

< 30

< 52

< 39

< 32

< 33

< 113

< 38 KOHLRABI 07/25/2024 31

< 27

< 64

< 32

< 37

< 26

< 48

< 35

< 28

< 35

< 108

< 40 SWISS CHARD 08/08/2024

< 29

< 59

< 36

< 68

< 26

< 48

< 37

< 33

< 110

< 34 TURNIP 08/08/2024

< 23

< 22

< 49

< 20

< 59

< 27

< 36

< 35

< 24

< 25

< 90

< 21 CABBAGE 08/08/2024

< 25

< 26

< 47

< 34

< 63

< 22

< 43

< 37

< 27

< 24

< 93

< 38 KALE 08/22/2024

< 40

< 33

< 79

< 36

< 84

< 44

< 60

< 46

< 49

< 44

< 128

< 70 TURNIP 08/22/2024

< 26

< 27

< 46

< 24

< 71

< 33

< 38

< 36

< 27

< 30

< 113

< 33 BWD-G1 CABBAGE 08/22/2024

< 23

< 21

< 51

< 18

< 40

< 21

< 27

< 25

< 24

< 17

< 80

< 27 KALE 09/05/2024

< 20

< 17

< 42

< 21

< 47

< 19

< 38

< 29

< 24

< 90

< 26 SWISS CHARD 09/05/2024

< 18

< 16

< 36

< 22

< 43

< 17

< 30

< 22

< 21

< 19 72

< 23 TURNIP 09/05/2024

< 16

< 13

< 27

< 17

< 34

< 14

< 25

< 19

< 16

< 17

< 58

< 14 KALE 09/19/2024

< 24

< 20

< 47

< 24

< 49

< 25

< 46

< 36

< 29

< 32

< 99

< 39 SWISS CHARD 09/19/2024

< 28

< 63

< 33

< 79

< 28

< 48

< 41

< 30

< 28

< 130

< 42 TURNIP 09/19/2024

< 28

< 60

< 24

< 63

< 23

< 39

< 36

< 31

< 28

< 130

< 29 CABBAGE 10/03/2024

< 8

< 7

< 15

< 8

< 17

< 8

< 14

< 13

< 9

< 8

< 35

< 10 KALE 10/03/2024

< 17

< 16

< 34

< 19

< 37

< 17

< 30

< 27

< 19

< 20

< 79

< 21 RADISH 10/03/2024

< 30

< 29

< 51

< 39

< 71

< 30

< 50

< 48

< 32

< 136

< 47 CABBAGE 10/17/2024

< 23

< 49

< 29

< 53

< 27

< 37

< 32

< 25

< 116

< 37 KALE 10/17/2024

< 33

< 59

< 51

< 40

< 37

< 54

< 45

< 38

< 35 131

< 30 RADISH 10/17/2024

< 30

< 28

< 57

< 29

< 81

< 29

< 49

< 36

< 29

< 30

< 116

< 46

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 53 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet +/- 2 Sigma) Cont'd Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates KALE 07/11/2024

< 31

< 38

< 79

< 33

< 67

< 38

< 53

< 52

< 30

< 42

< 141

< 48 CABBAGE 07/11/2024

< 34

< 33

< 80

< 37 77

< 33

< 57

< 53

< 34

< 38

< 155

< 38 KOHLRABI 07/11/2024

< 25

< 26 51

< 12

< 57

< 23

< 39

< 36

< 34

< 27

< 112

< 29 KALE 07/25/2024

< 26

< 34

< 78

< 51

< 87

< 37

< 52

< 51

< 43

< 38

< 159

< 35 CABBAGE 07/25/2024

< 31

< 38

< 76

< 40

< 80

< 40

< 54

< 48

< 40

< 35

< 145

< 32 TURNIP 07/25/2024

< 28

< 35

< 64

< 35 72

< 28

< 58

< 44

< 31

< 34

< 143

< 27 KALE 08/08/2024

< 26

< 27

< 57

< 27 77

< 26

< 60

< 31

< 29

< 148

< 37 CABBAGE 08/08/2024

< 19

< 21

< 35

< 24

< 43

< 17

< 40

< 28

< 23

< 17

< 82

< 28 TURNIP 08/08/2024

< 21

< 23

< 58

< 22

< 45

< 29

< 38 31

< 30

< 23

< 90

< 21 KALE 08/22/2024

< 29

< 25

< 64

< 37

< 65

< 24

< 57

< 47

< 34

< 141

< 39 CABBAGE 08/22/2024

< 16

< 19

< 43

< 17

< 42

< 21

< 31

< 34

< 23

< 27 101

< 34 TURNIP 08/22/2024

< 30

< 25

< 61

< 24

< 81

< 26

< 59

< 42

< 28

< 38

< 137

< 37 BWD-G2 KOHLRABI 09/05/2024

< 17

< 15

< 30

< 18

< 30

< 17

< 30

< 20

< 19

< 18

< 61

< 20 CABBAGE 09/05/2024

< 13

< 12

< 22

< 13

< 25

< 13

< 22

< 20

< 14

< 16

< 54

< 15 TURNIP 09/05/2024

< 15

< 30

< 16

< 35

< 16

< 27

< 19

< 16

< 18

< 59

< 19 CABBAGE 09/19/2024

< 17

< 14

< 33

< 16

< 31

< 19

< 25

< 31

< 20

< 90

< 26 KALE 09/19/2024

< 27

< 26

< 54

< 28

< 68

< 26

< 46

< 38

< 28

< 33

< 137

< 47 TURNIP 09/19/2024

< 29

< 25

< 60

< 29

< 57

< 22

< 43

< 36

< 37

< 120

< 48 RADISH 10/03/2024 11

< 12

< 24

< 15

< 27

< 12

< 20

< 15

< 12

< 13

< 48

< 16 SWISS CHARD 10/03/2024

< 14

< 15 31

< 15

< 29

< 14

< 23

< 19

< 13

< 16

< 57

< 17 KALE 10/03/2024

< 24

< 22 51

< 28

< 60

< 25

< 41

< 37

< 29

< 26

< 103

< 33 TURNIP 10/03/2024

< 13

< 12

< 26

< 13

< 24

< 12

< 22

< 16

< 13

< 50

< 17 CABBAGE 10/17/2024

< 26

< 27

< 41

< 26

< 49

< 28

< 42

< 32

< 25

< 26

< 97

< 29 KALE 10/17/2024

< 29

< 34

< 79

< 27

< 82

< 30

< 58

< 46

< 34

< 32

< 125

< 44 TURNIP 10/17/2024

< 22

< 38

< 24

< 61

< 30

< 37

< 24

< 112

< 31

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 54 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 17, Monthly Surface Water Gross Beta (pCi/L +/- 2 Sigma)

Collection Date BD-10 BD-25 BD-38 BD-40 BD-55 BD-56 01/04/2024 -

01/25/2024 3

+/-

2 4

+/-

2 4

+/-

2 8

+/-

3 4

+/-

2 4

+/-

2 02/01/2024 -

02/28/2024 5

+/-

2 4

+/-

2 8

+/-

2 11

+/-

3 4

+/-

2 9

+/-

2 03/07/2024 -

03/28/2024 9

+/-

3 5

+/-

2 8

+/-

3 9

+/-

3 4

+/-

2 4

04/04/2024 -

04/25/2024 5

+/-

2 7

+/-

2 13

+/-

3 13

+/-

3 4

+/-

2 3

+/-

2 05/02/2024 -

05/30/2024 4

+/-

2 4

+/-

2 9

+/-

3 12

+/-

3 3

3 06/06/2024 -

06/27/2024 5

+/-

2 4

+/-

2 4

+/-

2 8

+/-

3 3

+/-

2 3

07/03/2024 -

07/25/2024 5

+/-

2 3

+/-

2 4

8

+/-

3 3

3 08/01/2024 -

08/29/2024 7

+/-

2 6

+/-

2 9

+/-

3 3

+/-

2 4

+/-

2 2

+/-

2 09/05/2024 -

09/26/2024 5

+/-

2 5

+/-

2 8

+/-

3 12

+/-

3 4

+/-

2 3

+/-

2 10/03/2024 -

10/31/2024 5

+/-

2 3

6

+/-

4 6

+/-

4 4

4

+/-

2 11/07/2024 -

11/27/2024 7

+/-

2 6

+/-

2 8

+/-

3 13

+/-

3 3

+/-

2 5

+/-

2 12/05/2024 -

12/26/2024 5

+/-

2 5

+/-

2 8

+/-

3 13

+/-

3 3

+/-

2 2

+/-

1

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 55 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 18, Monthly Surface Water Nickel-63 and lron-55 (pCi/L +/- 2 Sigma)

Station Collection Date Ni-63 Fe-55 01/04/2024 01/25/2024 26 64 02/01/2024 02/28/2024 28 74 03/07/2024 03/28/2024 28 69 04/04/2024 04/25/2024 25 78 05/02/2024 05/30/2024 9

133 06/06/2024 06/27/2024 28 80 BD-10 07/03/2024 07/25/2024 26 85 08/01/2024 08/29/2024 23 83 09/05/2024 09/26/2024 16 58 10/03/2024 10/31/2024 16 129 11/07/2024 -

11/27/2024 22 85 12/05/2024 12/26/2024 21 39 01/04/2024 01/25/2024 29 102 02/01/2024 02/28/2024 27 67 03/07/2024 03/28/2024 27 54 04/04/2024 04/25/2024 28 51 05/02/2024 05/30/2024 8

92 06/06/2024 -

06/27/2024 28 131 BD-25 07/03/2024 07/25/2024 28 70 08/01/2024 08/29/2024 23 64 09/05/2024 09/26/2024 27 58 10/03/2024 10/31/2024 19 192 11/07/2024 11/27/2024 22 182 12/05/2024 12/26/2024 21 37

Annual Radiological Environmental Operating Report I YEAR: 2024-1 Page 56 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma)

Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/04/2024 01/25/2024 4

4 8

4 7

5 8

14 4

3

< 28

< 9 02/01/2024 02/28/2024 4

5 11

< 4 8

5 9

13 4

5

< 28

< 10 03/07/2024 03/28/2024 7

4 16 8

12 7

11 12 7

6

< 37

< 10 04/04/2024 04/25/2024

< 7 6

13 5

10 6

10 14 6

4

< 28

< 13 05/02/2024 05/30/2024 5

7 14 8

15 6

12 12 9

6

< 31

< 11 06/06/2024 06/27/2024 5

5 13 6

11 6

8 9

5 6

< 29

< 10 BD-10 07/03/2024 07/25/2024 5

5 12 5

12 5

9 10 5

5

< 28

< 8 08/01/2024 08/29/2024 4

5 11 5

9 6

10 14 6

6

< 36

< 12 09/05/2024 -

09/26/2024 2

2 5

2 4

9 2

2

< 18

< 6 10/03/2024 10/31/2024

< 7 9

14 9

12 7

13 12 9

7

< 37

< 13 11/07/2024 11/27/2024 5

6 15 5

10 5

10 15 7

6

< 36

< 4 12/19/2024 12/26/2024 3

3 6

3 5

8 3

3

< 17

< 6

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 57 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/04/2024 01/13/2024 1

2 5

2 3

15 2

2 20 8

02/15/2024 02/28/2024 4

5 11 5

9 6

9 14 5

5 30 11 03/07/2024 03/28/2024 7

6 13 8

12 8

10 13 9

7 32 13 04/25/2024 04/25/2024 4

5 10 7

11 4

9 14 5

5 26 8

05/02/2024 05/30/2024 6

7 16 6

12 7

13 11 7

7 28 10 06/06/2024 06/27/2024 6

6 13 7

11 6

9 10 6

6 25 8

BD-25 07/03/2024 07/25/2024 4

4 10 5

7 4

8 6

5 4

17 6

08/01/2024 08/29/2024 4

4 10 5

9 5

9 14 5

5 29 13 09/05/2024 09/26/2024 2

2 5

2 4

8 2

2 16 5

10/03/2024 10/31/2024 5

4 12 7

10 5

9 9

5 6

25 10 11/07/2024 11/27/2024 5

5 9

4 8

5 8

14 4

5 30 8

12/19/2024 12/26/2024 5

5 10 6

10 7

9 14 5

5 32 12

Annual Radiological Environmental Operating Report I YEAR: 2024 1 Page 58 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/04/2024 01/25/2024 2

3 6

3 5

9 3

3 21 7

02/01/2024 02/28/2024 4

5 11 5

9 5

8 13 5

4 30 9

03/07/2024 03/28/2024 6

5 16 6

14 8

11 11 6

7 29 12 04/04/2024 -

04/25/2024 5

5 11 5

11 6

9 13 4

5 33 9

05/02/2024 05/30/2024 7

7 11 7

10 7

7 10 7

6 31 9

06/06/2024 06/27/2024 6

6 15 4

12 7

10 9

8 6

27 9

BD-38 07/03/2024 -

07/25/2024 6

5 12 6

9 6

10 12 6

5 28 9

08/01/2024 08/29/2024 5

5 11 4

9 6

9 14 6

4 30 10 09/05/2024 09/26/2024 2

2 4

8 2

2 15 6

10/03/2024 -

10/31/2024 7

7 14 9

17 7

14 14 8

9 34 13 11/07/2024 11/27/2024 5

6 12 6

12 5

9 13 6

5 36 14 12/05/2024 12/26/2024 3

5 11 4

9 5

8 13 4

4 28 9

Annual Radiological Environmental Operating Report l YEAR: 2024 I

Page 59 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/04/2024 01/25/2024 4

4 9

4 8

6 9

12 3

5 37

< 10 02/01/2024 02/28/2024 5

4 11 5

10 6

8 13 5

5 32

< 13 03/07/2024 03/28/2024 5

5 11 6

13 8

11 12 6

6 26

< 12 04/04/2024 04/25/2024 5

6 11 5

12 5

12 15 6

5 32

< 15 05/02/2024 05/30/2024 7

6 17 6

10 8

11 9

8 6

28

< 10 06/06/2024 06/27/2024 4

4 11 3

11 5

8 6

4 5

19

< 9 BD-40 07/03/2024 -

07/25/2024 5

6 11 5

12 6

11 9

6 6

24

< 11 08/01/2024 08/29/2024 4

5 9

5 8

13 5

4 31

< 10 09/05/2024 09/26/2024 2

2 5

2 4

9 2

2 19

< 6 10/03/2024 10/31/2024 9

8 18 7

18 10 13 14 10 8

39

< 14 11/07/2024 11/27/2024 6

7 14 7

14 6

12 14 7

5 37

< 13 12/05/2024 12/26/2024 3

3 7

4 6

3 6

9 3

3 22

< 6

Annual Radiological Environmental Operating Report I YEAR: 2024 T Page 60 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/04/2024 01/11/2024 2

3 6

2 5

3 5

14 2

2 35 13 02/01/2024 02/28/2024 4

5 13 5

9 6

9 14 5

5 33 11 03/07/2024 03/28/2024 5

7 15 7

15 7

12 13 7

7 34 10 04/04/2024 04/25/2024 4

5 12 6

11 6

9 15 6

5 30 11 05/02/2024 05/30/2024

< 7 5

13 10 16

< 7 13 11

< 6 7

31 12 06/06/2024 06/27/2024 6

7 15 7

15 8

12 9

8 8

28 13 BD-55 07/03/2024 07/25/2024 6

7 14 8

12 5

11 10 7

7 29 6

08/01/2024 08/29/2024 5

6 11 5

9 5

9 14 5

4 31 10 09/05/2024 09/26/2024 2

2 5

2 4

9 2

2 16 5

10/03/2024 10/31/2024 5

6 12 7

13 6

12 10 8

6 31 9

11/07/2024 11/27/2024 5

6 12 6

9 5

9 13 6

6 31 14 12/05/2024 12/26/2024 5

4 12 7

9 7

10 15 6

5 43 12

Annual Radiological Environmental Operating Report

\ YEAR: 2024 I

Page 61 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/04/2024 01/11/2024 1

2 3

1 2

2 3

15 1

1 19

< 7 02/01/2024 02/28/2024 4

6 12 5

11 6

9 13 4

5 26 6

03/07/2024 03/28/2024 7

7 10 7

12 5

12 11 8

6 29 12 04/04/2024 04/25/2024 6

6 11 6

10 5

10 15 7

6 35 11 05/02/2024 05/30/2024 6

8 16 7

13 6

14 11 8

8 29 12 06/06/2024 06/27/2024 6

6 9

5 10 7

11 9

9 7

32 12 BD-56 07/03/2024 07/25/2024 6

6 10 7

13 7

10 10 6

6 30 10 08/01/2024 08/29/2024 4

5 11 5

9 6

8 13 5

5 31 10 09/05/2024 09/26/2024 2

2 4

2 3

8 2

2 15 5

10/03/2024 -

10/31/2024 6

6 13 8

16 7

13 9

7 7

32 9

11/07/2024 11/27/2024 5

5 12 6

10 5

9 12 6

6 32 10 12/26/2024 12/26/2024 5

5 10 4

9 5

9 14 5

5 34 8

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 62 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 20, Quarterly Surface Water Tritium (pCi/L +/- 2 Sigma)

Station Collection Dates H-3 01/04/2024 03/28/2024 184 04/04/2024 06/27/2024 196 BD-10 07/03/2024 -

09/26/2024 738

+/-

157 10/03/2024 12/26/2024 485

+/-

129 01/04/2024 03/28/2024 189 04/04/2024 06/27/2024 196 BD-25 07/03/2024 09/26/2024 185 10/03/2024 12/26/2024 183 01/04/2024 -

03/28/2024 186 04/04/2024 06/27/2024 195 BD-38 07/03/2024 09/26/2024 179 10/03/2024 12/26/2024 179 01/04/2024 03/28/2024 183 04/04/2024 -

06/27/2024 198 BD-40 07/03/2024 -

09/26/2024 183 10/03/2024 12/26/2024 175 01/04/2024 03/28/2024 183 04/04/2024 06/27/2024 198 BD-55 07/03/2024 09/26/2024 184 10/03/2024 12/26/2024 176 01/04/2024 03/28/2024 184 04/04/2024 06/27/2024 196 BD-56 07/03/2024 -

09/26/2024 184 10/03/2024 -

12/26/2024 174

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 63 of 81 Com~y~onstellation...... *~*** J Plant: Braidwood Station Units 1 and 2 Table 21, Monthly Public Water Gross Beta, Tritium, lron-55, Nickel-63, and 1-131 (pCi/L +/- 2 Sigma)

Station Collection Dates Gross Beta H-3 Fe-55 Ni-63 1-131 12/28/2023 01/25/2024 4

+/-

2 198 66 23 0.9 01/25/2024 02/28/2024 2

1090

+/-

186 88 27 0.6 02/28/2024 03/28/2024 3

1140

+/-

191 63 30 0.9 03/28/2024 04/25/2024 3

+/-

2 858

+/-

169 196 23 1

04/25/2024 05/30/2024 3

+/-

2 286

+/-

140 130 8

0.8 05/30/2024 06/27/2024 5

+

2 376

+/-

122 141 25 1

BD-22 06/27/2024 07/25/2024 6

+/-

2 271

+/-

127 90 24 0.9 07/25/2024 08/29/2024 4

1050

+/-

182 121 17 0.9 08/29/2024 09/26/2024 3

+/-

2 1350

+/-

205 63 18 0.7 09/26/2024 10/31/2024 4

+/-

2 1070

+/-

193 63 27 0.9 10/31/2024 11/27/2024 5

+/-

2 782

+/-

158 88 27 0.9 11/27/2024 01/02/2025 4

+/-

2 1190

+/-

189 165 24 0.9

Annual Radiological Environmental Operating Report i_ YEA~: 2024 J Page 64 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 22, Monthly Public Water Gamma Isotopic (pCi/L +/- 2 Sigma)

Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 12/28/2023 01/25/2024 2

3 5

2 5

3 4

2 2

< 18

< 5 01/25/2024 02/28/2024 4

5 15 6

11 6

9 5

5

< 27

< 13 02/28/2024 03/28/2024 5

5 12 5

13 5

10 5

5

< 23

< 8 03/28/2024 04/25/2024 5

6 11 7

13 6

8 5

5

< 30

< 8 04/25/2024 05/30/2024 5

6 13 7

12 5

12 6

6

< 28

< 11 05/30/2024 06/27/2024 6

6 8

7 8

6 8

6 4

< 28

< 13 BD-22 06/27/2024 07/25/2024 1

1 3

1 2

1 1

< 11

< 4 07/25/2024 08/29/2024 2

2 4

2

< 4 2

3 2

2

< 18

< 5 08/29/2024 09/26/2024 1

1 3

2 3

1 2

1 1

< 9

< 3 09/26/2024 10/31/2024 1

1 3

1 2

1 1

< 17

< 6 10/31/2024 -

11/27/2024 6

8 16 6

14 6

17 9

7

< 21

< 12 11/27/2024 01/02/2025 5

6 7

5 6

5 10 4

5

< 27

< 11

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 65 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 23, Quarterly Groundwater Tritium (pCi/L +/- 2 Sigma)

Collection BD-13 BD-34 BD-35 BD-36 BD-37 BD-50 BD-51 BD-54 Date 01/13/2024

< 192

< 179

< 188

< 184 179 (1)

< 184

< 198 03/28/2024

< 185 04/11/2024 191

< 196

< 189

< 192

< 196

< 193

< 199

< 196 07/11/2024

< 198

< 194

< 187

< 190 191

< 185

< 188

< 185 10/10/2024 181

< 180

< 183

< 180

< 178

< 180

< 177

< 180 (1) See Sample Deviations Table

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 66 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 24, Quarterly Ground Water Gamma Isotopic (pCi/L +/- 2 Sigma)

Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/11/2024 01/11/2024 5

5 14 5

13

< 6 8

14 6

< 6 31 13 04/11/2024 04/11/2024 6

8 13 9

15 8

12 11 8

9

< 34 12 BD-13 07/11/2024 -

07/11/2024 5

5 11 5

13 5

11 8

7

< 4

< 22 9

10/10/2024 10/10/2024 7

7 14 5

15 7

13 9

7

< 7

< 34 10 01/11/2024 -

01/11/2024 5

6 10 7

10 5

12 14 5

< 5

< 26 8

04/11/2024 04/11/2024 8

7 18 7

13 8

8 10 8

< 7 31 8

BD-34 07/11/2024 07/11/2024 5

5 11 5

10 5

8 8

5 5

< 27 6

10/10/2024 -

10/10/2024 7

5 15 8

18 8

14 14 6

< 9

< 37 12 01/11/2024 01/11/2024 5

< 4 10 5

10 6

9 14 5

5

< 27 11 04/11/2024 04/11/2024 5

6 13 6

13 6

9 11 7

7 31 10 BD-35 07/11/2024 07/11/2024 5

4 10 6

8

< 4 8

8 5

5

< 22 7

10/10/2024 10/10/2024 7

7 15 8

18 7

12 11 7

8

< 28 10

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 67 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 24, Quarterly Ground Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/11/2024 01/11/2024 5

6 10 7

14 6

10 14 8

6 27 9

04/11/2024 04/11/2024 7

5 13 6

11 8

10 10 6

7 29 10 BD-36 07/11/2024 07/11/2024 6

5 13 7

12 6

9 9

7 6

28 8

10/10/2024 10/10/2024 6

7 11 7

10

< 7 13 10 8

7 24 8

01/13/2024 01/13/2024 6

6 9

8 12 6

9 13 6

< 7 37 14 04/11/2024 04/11/2024 7

8 14 9

16 7

14 9

6 8

36 12 BD-37 07/11/2024 07/11/2024 5

6 10 5

9 5

9 7

4 5

21 7

10/10/2024 10/10/2024 7

7 16 6

15 6

10 10 8

6 26 8

03/28/2024 03/28/2024 6

5 10 6

10

< 7 10 11 5

6 30 11 04/11/2024 04/11/2024 7

7 16 8

16 5

11 10 8

7 32 11 BD-50 07/11/2024 07/11/2024 4

4 9

5 11 5

9 9

5 5

23

< 7 10/10/2024 10/10/2024 6

7 13 6

9 6

11 11 5

6 24 9

Annual Radiological Environmental Operating Report I YEAR: 2024~ I Page 68 of 81 Company: Constellation

....... J Plant: Braidwood Station Units 1 and 2 Table 24, Quarterly Ground Water Gamma Isotopic (pCi/L +/- 2 Sigma) Cont'd Station Collection Dates Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01/11/2024 01/11/2024 6

5 12 6

12 5

10 13 5

< 6 31 14 04/11/2024 04/11/2024 7

6 14 8

13 6

12 11 7

7

< 29 10 BD-51 07/11/2024 07/11/2024 5

5 11 5

9 5

8 8

4 5

22 9

10/10/2024 10/10/2024 5

7 10

< 7 11 7

8 8

6 6

32 14 01/11/2024 01/11/2024 4

5 11

< 4 10 5

8 14 5

5 32 7

04/11/2024 04/11/2024 6

7 12 7

11 7

12 12 6

7 31 9

BD-54 07/11/2024 -

07/11/2024

< 4

< 4 9

5 8

6 5

4 18 8

10/10/2024 10/10/2024 7

6 11 8

15 8

12 12 8

7 37 11

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 69 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 25, Semi-Annual Fish lron-55, Nickel-63, and Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)

Station Collection Fe-55 Ni-63 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140 Dates Channel 06/03/2024

< 254

< 60 Catfish 71

< 66 126 76 147

< 84 127

< 148

< 66

< 57

< 418

< 142 Small mouth 06/03/2024

< 212

< 67

< 94 72 178

< 92 175

< 69 118 177

< 85

< 80

< 460

< 142 Bass 80-25 Common Carp 09/23/2024

< 183 158 72

< 62 120

< 75 125

< 79

< 107

< 332

< 60

< 66

< 692

< 217 Bigmouth 09/23/2024

< 253 133

< 70

< 96 151 61 151

< 77 120

< 391

< 85

< 72

< 695

< 225 Buffalo Flathead 06/03/2024

< 143

< 73

< 58 60 107

< 68 135 71

< 97 102

< 64

< 58

< 253

< 102 Catfish Common 06/03/2024

< 242

< 75

< 68

< 63 154

< 50 137

< 75 125 121

< 66

< 58

< 349

< 88 Carp 80-28 Channel Catfish 09/23/2024

< 248 119

< 50 52 124

< 48 104 51

< 77

< 263 51

< 42

< 407

< 123 Common 09/23/2024

< 254 124

< 68 61

< 200

< 63 119

< 77

< 497

< 53

< 59

< 715

< 273 Carp Largemouth 06/03/2024

< 248

< 65

< 65 79 185

< 79 161

< 94 107

< 142

< 75

< 53

< 299

< 154 Bass Flathead 06/03/2024

< 215 53

< 62 61 142

< 82 91

< 69 102 115

< 57

< 51

< 318

< 121 80-41 Catfish Largemouth 09/23/2024

< 157 109

< 47

< 62 144

< 42 117

< 70 116

< 535

< 52

< 49

< 819

< 229 Bass Common 09/23/2024

< 259 159

< 62

< 73 165 Carp 60 110

< 78 140

< 629

< 76

< 54

< 775

< 308

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 70 of 81 Company: Constellation J Plant: Braidwood Station Units 1 and 2 Table 26, Semi-Annual Shoreline Sediment lron-55, Nickel-63, and Gamma Isotopic (pCi/kg Dry+/- 2 Sigma)

Station Collection Fe-55 Ni-63 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 Dates 05/15/2024

< 1987

< 235

< 56

< 55

< 134 71

< 126

< 60

< 106

< 69

< 75

< 225

< 79 BD-10 10/16/2024

< 1982

< 235

< 87

< 90

< 192

< 97

< 281

< 113

< 154

< 110

< 95

< 398

< 125 05/15/2024

< 1935

< 217

< 50

< 51

< 120

< 57 111

< 53

< 80

< 59 121

+/- 74

< 226

< 88 BD-25 10/16/2024

< 1544

< 240

< 53

< 57

< 114

< 57

< 130

< 58

< 113

< 65

< 67

< 258

< 68 05/15/2024

< 1602

< 251

< 43

< 47

< 115

< 52

< 129

< 47

< 82

< 59

< 48

< 205

< 54 BD-57 10/16/2024

< 1473 131

< 69

< 70

< 130

< 61

< 160

< 78

< 110 72

< 76

< 331

< 103

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 71 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2, Cross Check lntercomparison 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. lntercomparison 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.

Teledyne Brown Engineering Inc. (TBE) participated in the following proficiency testing studies provided by Eckert Ziegler Analytics, DOE's Mixed Analyte Performance Evaluation Program (MAPEP), and/or Environmental Resource Associates (ERA) in 2024. The Laboratory's intercomparison program results for 2024 are summarized below.

For the TBE laboratory, 152 out of 167 analyses performed met the specified acceptance criteria. Fifteen analyses did not meet the specified acceptance criteria and were addressed through the TBE Corrective Action Program. A summary is found below:

I.

NCR 24-02: ERA March MRAD-40 study with Air Particulate AM-241 evaluated as "Not Acceptable." TBE reported 38.8 pCi/filter and the known value returned at 55.0 pCi/filter (range 39.3-73.3). The root cause investigation determined that the sample was not logged into the system correctly and therefore not prepared with the required tracer. To correct and prevent recurrence, personnel involved are to utilize a template to ensure all analyses are logged as required and the QA Manager will perform sample log review as a back up to ensure accuracy. Acceptable results returned in a later sample study, supporting effectiveness of corrective action.

II.

NCR 24-03: ERA March MRAD-40 air particulate study GR-B evaluated as "Not Acceptable." TBE reported 42.1 pCi/filter and the known value returned at 22.2 pCi/filter (range 13.5-33.5). The root cause investigation determined that alpha-to-beta crosstalk was more significant than normal which caused the beta activity to report falsely high data. To correct and prevent recurrence, personnel involved are to adjust the alpha-to-beta crosstalk via correction calculation measures when high alpha activities are observed. Acceptable results returned in a later sample study, supporting effectiveness of corrective action.

Ill.

NCR 24-05: ERA April RAD-137 water study GR-A evaluated as "Not Acceptable."

TBE reported 35.2 pCi/L and the known value returned at 52.6 pCi/L (range 39.6-65.6). The root cause investigation determined that the provided samples contained a solids content that was significantly higher than the typical client samples tested by the laboratory. A set aliquot volume for prior ERA samples was used and not adjusted to account for the sudden increase in solid content. To correct and prevent recurrence, new sample types were ordered from ERA that used Am-241 to better reflect client sample testing and acceptable results were achieved. Acceptable results returned in a later sample study, supporting effectiveness of corrective action.

IV.

NCR 24-06: E&Z Analytics March E14092 air particulate study Co-60 evaluated as "Not Acceptable." TBE reported 168 pCi and the known value returned at 126 pCi.

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 72 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Additionally, March E14093 soil Ce-141 evaluated as "Not Acceptable." TBE reported 0.106pCi/g and the known value returned at 0.071 pCi/g. The root cause investigation was unable to determine any anomaly thus no proposed corrective action. No recurrence has occurred.

V.

CAR 24-02 (CAR 23-31 ): MAPEP February 24-MaS50 soil study Fe-55 evaluated as "Not Acceptable." TBE reported 297 Bg/Kg and the known value returned at 650 Bg/Kb (range 455-845). The root cause investigation suspects that the current analytical procedure is not sufficient to add the interferences added to the sample by MAPEP.

This investigation is still ongoing (See NCR 24-16) as the suggested corrective action did not provide desired results.

VI.

NCR 24-08: MAPEP February 24-MaS50 soil study Ni-63 evaluated as "Not Acceptable." TBE reported 1070 Bg/Kg and the known value returned at 1530 Bg/Kb (range 1071-1989). The root cause investigation suspected that the sample contained added interferences that are not typically seen in client samples. All QC efforts associated with the sample were acceptable and no anomalies found, even after reanalysis. To correct and prevent recurrence, samples suspected of additional interferences will include the addition of Ni-59 tracer to determine yield results when calculating results. TBE analytical procedure TBE-2013 was updated to include this change.

VII.

NCR 24-09: MAPEP February 24-MaSU50 urine study Zn-65 evaluated as "Not Acceptable." The root cause investigation determined that the sample was spiked lower than TBE's typical detection limit and client requirements. The report was revised by MAPEP indicating "Not Evaluated," resulting in this nuclide to not be considered a failure.

VIII.

NCR 24-10: MAPEP February 24-MaW50 water study Tc-99 evaluated as "Not Acceptable." TBE reported 9.95Bg/L and the known value returned 7.47Bg/L (range 5.23-9. 71 ). The root cause investigation suspects Thorium interference that was not removed during the column separation process of the analytical procedure; however, it cannot be confirmed as all QC efforts associated with the sample were acceptable and with no anomalies found. To potentially correct and prevent recurrence, an additional rinse step was added to the procedure. Acceptable results returned in a later sample study, supporting effectiveness of corrective action.

IX.

NCR 24-11: MAPEP February 24-RdV50 vegetation study Sr-90 evaluated as "Not Acceptable." TBE reported 0.276Bg/sample and the known value returned 0.529Bg/sample (range 0.370-0.688). The root cause investigation determined a laboratory accident resulting in a spilled (loss) of sample. No corrective action was performed as the cause was an unintentional sample spill.

X.

NCR 24-14: ERA September MRAD-41 air particulate study U-234/238 evaluated as "Not Acceptable." TBE reported 14.0/14.2 pCi/filter and the known value returned at 31.1/30.9 pCi/filter (range 23.1-36.9). The root cause investigation determined that the laboratory technician placed double the amount of tracer in the sample by error. To correct and prevent recurrence, samples that have been digested/leached with carrier/tracer added will have a label placed over the cap indicating it has already been added. Additionally, the beaker that aliquot is put in should have markings to indicate

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 73 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 carrier/tracer has already been added to the sample.

XI.

NCR 24-15: ERA September MRAD-41 water study Fe-55 evaluated as "Not Acceptable." TBE reported 615 pCi/L and the known value returned at 1230 pCi/L (range 723-1790). The root cause is still under investigation.

XII.

NCR 24-16: MAPEP August 24-MaS50 soil study Fe-55 evaluated as "Not Acceptable." TBE did not report a value and the known value returned 780Bg/Kg (range 546-1014). The root cause is still under investigation.

XIII.

NCR 24-17: MAPEP August 24-RdV51 vegetation study Sr-90 evaluated as "Not Acceptable." TBE reported 0.95Bg/sample and the known value returned 2.39Bg/sample (range 1.67-3.11 ). The root cause is still under investigation.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 74 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 27: Analytics Environmental Radioactivity Cross Check Program Teledyne Brown Engineering Environmental Services Identification TBE Known Ratio ofTBE Evaluation Month/Year Number Matrix Nuclide Units Reported Value (aJ to Analytics (b)

Value Result March 2024 E14089 Milk Sr-89 pCi/L 79.6 78.2 1.02 A

Sr-90 pCi/L 12.6 11.9 1.06 A

E14090 Milk Ce-141 pCi/L 75.6 85.0 0.89 A

Co-58 pCi/L

-0.069 Not Measured Co-60 pCi/L 139 158 0.88 A

Cr-51 pCi/L 212 230 0.92 A

Cs-134 pCi/L 167 198 0.84 A

Cs-137 pCi/L 158 171 0.93 A

Fe-59 pCi/L 81.1 86.5 0.94 A

1-131 pCi/L 80.9 90.8 0.89 A

Mn-54 pCi/L 173 183 0.95 A

Zn-65 pCi/L 165 176 0.93 A

E14091 Charcoal 1-131 pCi 90.1 90.3 1.00 A

E14092 AP Ce-141 pCi 68.1 67.5 1.01 A

Co-58 pCi 1.73 Not Measured Co-60 pCi 168 126 1.34 N(1J Cr-51 pCi 182 183 0.99 A

Cs-134 pCi 157 157 1.00 A

Cs-137 pCi 132 136.0 0.97 A

Fe-59 pCi 70.3 68.6 1.02 A

Mn-54 pCi 144 145 0.99 A

Zn-65 pCi 125 140 0.89 A

E14093 Soil Ce-141 pCi/g 0.106 0.071 1.48 N(1J Co-58 pCi/g

-0.005 Not Measured Co-60 pCi/g 0.121 0.133 0.91 A

Cr-51 pCi/g 0.198 0.194 1.02 A

Cs-134 pCi/g 0.206 0.166 1.24 w

Cs-137 pCi/g 0.207 0.209 0.99 A

Fe-59 pCi/g 0.063 0.073 0.87 A

Mn-54 pCi/g 0.140 0.153 0.91 A

Zn-65 pCi/g 0.149 0.148 1.01 A

E14094 AP Sr-89 pCi 83.9 90.6 0.93 A

Sr-90 pCi 11.7 13.8 0.85 A

(a) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) Analytics evaluation based on TBE internal QC limits:

A = Acceptable - reported result falls within ratio limits of 0.80-1.20 W = Acceptable with warning - reported result falls within 0.70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and > 1.30 (1) See NCR 24-06

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 75 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 27: Analytics Environmental Radioactivity Cross Check Program Cont'd Teledyne Brown Environmental Services Month/Year Identification Matrix Nuclide Units TBE Reported Known Ratio of TBE to Evaluation Number Value Value (a)

Analytics Result (b)

September 2024 E14095 Milk Sr-89 pCi/L 88.0 92.3 0.95 A

Sr-90 pCi/L 12.4 15.2 0.82 A

E14096 Milk Ce-141 pCi/L 124 124 1.00 A

Co-58 pCi/L 154 150 1.03 A

Co-60 pCi/L 232 236 0.98 A

Cr-51 pCi/L 284 274 1.04 A

Cs-134 pCi/L 180.0 187 0.96 A

Cs-137 pCi/L 126 127 0.99 A

Fe-59 pCi/L 127.0 113 1.12 A

1-131 pCi/L 85.3 89.0 0.96 A

Mn-54 pCi/L 162 162 1.00 A

Zn-65 pCi/L 294 275 1.07 A

E14097 Charcoal 1-131 pCi 98.8 92.6 1.07 A

E14098 AP Ce-141 pCi 82.0 76.7 1.07 A

Co-58 pCi 91.0 92.6 0.98 A

Co-60 pCi 180 146 1.23 w

Cr-51 pCi 208 170 1.22 w

Cs-134 pCi 116 116 1.00 A

Cs-137 pCi 83.1 78.9 1.05 A

Fe-59 pCi 75.6 70.2 1.08 A

Mn-54 pCi 101 100 1.01 A

Zn-65 pCi 167 170 0.98 A

E14099 Soil Ce-141 pCi/g 0.224 0.222 1.01 A

Co-58 pCi/g 0.249 0.268 0.93 A

Co-60 pCi/g 0.420 0.423 0.99 A

Cr-51 pCi/g 0.492 0.492 1.00 A

Cs-134 pCi/g 0.278 0.336 0.83 A

Cs-137 pCi/g 0.276 0.295 0.94 A

Fe-59 pCi/g 0.233 0.204 1.14 A

Mn-54 pCi/g 0.279 0.290 0.96 A

Zn-65 pCi/g 0.538 0.494 1.09 A

E14100 AP Sr-89 pCi 79.8 82.7 0.96 A

Sr-90 pCi 12.0 13.6 0.88 A

Gr-A E14197 Liquid (Am241) pCi/L 47.6 50.1 0.95 A

Gr-B (Cs137) pCi/L 248 270 0.92 A

(a) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) Analytics evaluation based on TBE internal QC limits:

A= Acceptable - reported result falls within ratio limits of 0.80-1.20 W = Acceptable with warning - reported result falls within 0.70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and > 1.30

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 76 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 28: DOE's Mixed Analyte Performance Evaluation Program (MAPEP)

Teledyne Brown Engineering Environmental Services Identification TBE Known Acceptance Evaluation Month/Year Number Matrix Nuclide Units Reported Value Range (b)

Value (a)

February 2024 24-MaS50 Soil Fe-55 Sq/kg 297 650 455 - 845 N(3)

Ni-63 Sq/kg 1070 1530 1071 - 1989 N(4)

Tc-99 Sq/kg 325 336 235 - 437 A

Th-228 Sq/kg 34.6 48.8 34.2 - 63.4 w

Th-230 Sq/kg 49.7 54.0 38.0 - 70.0 A

Th-232 Sq/kg 36.4 45.1 31.6 - 58.6 A

24-MaSU50 Urine Cs-134 Sq/L 1.12 1.36 0.95 - 1.77 A

Cs-137 Sq/L 2.00 2.23 1.56 - 2.90 A

Co-57 Sq/L 1.06 1.26 0.88 - 1.64 A

Co-60 Sq/L 2.26 2.38 1.67 - 3.09 A

K-40 Sq/L

-1.80 NR Mn-54 Sq/L 1.44 1.51 1.06 - 1.96 A

U-234 Sq/L 0.00101 (1)

A U-238 Sq/L 0.00228 (1)

A Zn-65 Sq/L

-0.42 0.84 0.59 - 1.09 NE(5>

24-MaW50 Water Ni-63 Sq/L 0.338 0.80 (2)

A Tc-99 Sq/L 9.95 7.47 5.23 - 9.71 N(6) 24-RdV50 Vegetation Cs-134 Sq/sample 2.80 3.67 2.57 - 4.77 w

Cs-137 Sq/sample 2.21 2.57 1.80 - 3.34 A

Co-57 Sq/sample 2.23 2.53 1.77-3.29 A

Co-60 Sq/sample 2.42 2.96 2.07 - 3.85 A

Mn-54 Sq/sample 0.033 (1)

A Sr-90 Sq/sample 0.276 0.529 0.370 - 0.688 N(?)

Zn-65 Sq/sample 6.83 8.02 5.61 -10.43 A

(a) The MAPEP known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) DOEIMAPEP evaluation:

A = Acceptable - reported result falls within ratio limits of 0.80-1.20 W = Acceptable with warning-reported result falls within 0. 70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and> 1.30 (1) False positive test (2) Sensitivity evaluation (3) See CAR 23 Analyte not on XCHK list (4) See NCR 24-08 (5) Not Evaluated (6) See NCR 24-10 (7) See NCR 24-11 (8) Not Reported (9) See NCR 24-16 (10) See NCR 24-17

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 77 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 Table 28: DOE's Mixed Analyte Performance Evaluation Program (MAPEP) Cont'd Teled}'.'.ne Brown Engineering Environmental Services Identification TSE Known Acceptance Evaluation Month/Year Number Matrix Nuclide Units Reported Value Range (b)

Value (a)

August 2024 24-MaS51 Soil Fe-55 Sq/kg (8) 780 546 - 1014 N(9)

Ni-63 Sq/kg 1140.00 1450.00 1015-1885 w

Tc-99 Sq/kg 155.00 171.00 120 - 222 A

Th-228 Sq/kg 38.00 43.30 30.3 - 56.3 A

Th-230 Sq/kg 46.10 44.00 30.8 - 57.2 A

Th-232 Sq/kg 38.90 42.60 29.8 - 55.4 A

24-MaW51 Water Ni-63 Sq/L 0.60 (1)

A Tc-99 Sq/L 11.90 11.20 7.8 - 14.6 A

24-RdV51 Vegetation Cs-134 Sq/sample 3.12 2.89 2.02 - 3.76 A

Cs-137 Sq/sample 2.18 1.91 1.34 - 2.48 A

Co-57 Sq/sample 0.00 (1)

A Co-60 Sq/sample 2.24 2.01 1.41 - 2.61 A

Mn-54 Sq/sample 3.76 3.53 2.47 - 4.59 A

Sr-90 Sq/sample 0.95 2.39 1.67 - 3.11 N(10)

Zn-65 Sq/sample 10.30 9.13 6.39 - 11.87 A

( a) The MAPEP known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) DOE/MAPEP evaluation:

A = Acceptable - reported result falls within ratio limits of 0.80-1.20 W = Acceptable with warning-reported result falls within 0. 70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of< 0. 70 and> 1.30 (1) False positive test (2) Sensitivity evaluation (3) See CAR 23 Analyte not on XCHK list (4) See NCR 24-08 (5) Not Evaluated (6) See NCR 24-10 (7) See NCR 24-11 (8) Not Reported (9) See NCR 24-16 (10) See NCR 24-17

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 78 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2 MonthNear March 2024 April 2024 Table 29: ERA Environmental Radioactivity Cross Check Program Teledyne Brown Engineering Environmental Services Identification TBE Known Acceptance Number Matrix Nuclide Units Reported Value(*)

Limits Value MRAD-40 Water Am-241 pCi/L 101 139 95.4 - 178 Fe-55 pCi/L 2185 2480 1460- 3610 Pu-238 pCi/L 62.0 70.4 42.3 - 91.2 Pu-239 pCi/L 61.2 76.5 47.3 - 94.3 Soil Am-241 pCi/kg NR 1880 1020 - 2660 Pu-238 pCi/kg 667 512 255 - 778 Pu-239 pCi/kg 562 545 297 - 784 Sr-90 pCi/kg 4050 3630 1130 - 5650 U-234 pCi/kg 3040 4360 2040 - 5710 U-238 pCi/kg 3270 4320 2370 - 5800 AP Am-241 pCi/filter 38.8 55.0 39.3 - 73.3 Fe-55 pCi/filter 387 386 141-616 Pu-238 pCi/filter 45.9 41.1 31.0 - 50.5 Pu-239 pCi/filter 54.9 56.1 41.9 - 67.7 U-234 pCi/filter 11.1 11.6 8.60 - 13.6 U-238 pCi/filter 12.8 11.5 8.68 - 13.7 GR-A pCi/filter 116 95.9 50.1 -158 GR-B pCi/filter 42.1 22.2 13.5 - 33.5 RAD-137 Water Ba-133 pCi/L 62.8 65.9 50.1 - 81.7 Cs-134 pCi/L 51.0 57.8 42.8 - 72.8 Cs-137 pCi/L 153 186 149 - 223 Co-60 pCi/L 92.1 98.8 79.7-118 Zn-65 pCi/L 208 240 188 - 292 GR-A pCi/L 35.2 52.6 39.6 - 65.6 GR-B pCi/L 49 46.5 33.9 - 59.1 U-Nat pCi/L 56.0 59.3 52.8-65.8 H-3 pCi/L 19,000 21,300 18,200 - 24,400 Sr-89 pCi/L 48.9 52.2 37.8 - 66.6 Sr-90 pCi/L 32.6 37.6 32.0 -43.2 1-131 pCi/L 21.8 25.1 21.7 - 28.5 Evaluation (b)

A A

A N(1)

A A

N(2)

A A

A N(3)

A A

(a) The ERA known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation.

(b) ERA evaluation:

A = Acceptable - Reported value falls within the Acceptance Limits N = Not Acceptable - Reported value falls outside of the Acceptance Limits (1) See NCR 24-02 (2) See NCR 24-03 (3) See NCR 24-05 (4) See NCR 24-15 (5) See NCR 24-14

Annual Radiological Environmental Operating Report I YEAR: 2024 j Page 79 of 81 Com_p_any: Constellation I Plant: Braidwood Station Units 1 and 2, Environmental Direct Radiation Dosimetry Results BD-03 16.2 20.9 16.3 13.4 13.1 16.8 ND ND ND ND 64.9 74.6 59.6 ND BD-02 15.9 20.6 14.1 16.5 16.2 16.8 ND ND ND ND 63.8 73.4 63.6 ND BD-04 15.1 19.7 13.8 14.8 13.4 15.9 ND ND ND ND 60.4 70.1 57.9 ND BD-05 16.1 20.8 16.7 17.2 15.6 16.6 ND ND ND ND 64.5 74.1 66.1 ND BD-101 15.7 20.4 17.0 14.3 14.4 15.1 ND ND ND ND 62.9 72.5 60.8 ND BD-102 15.7 20.3 12.6 15.3 13.7 14.5 ND ND ND ND 62.6 72.3 56.1 ND BD-103 15.6 20.2 15.8 17.1 14.6 15.3 ND ND ND ND 62.4 72.0 62.8 ND BD-104 14.6 19.2 15.7 14.9 12.9 14.1 ND ND ND ND 58.4 68.1 57.6 ND BD-105 14.9 19.5 13.6 13.0 13.9 13.7 ND ND ND ND 59.5 69.1 54.2 ND BD-106 14.5 19.2 13.0 14.3 15.0 16.4 ND ND ND ND 58.2 67.8 58.7 ND BD-107 14.7 19.4 14.8 16.3 15.3 15.8 ND ND ND ND 58.9 68.6 62.2 ND BD-108 15.3 20.0 15.2 14.0 13.7 15.5 ND ND ND ND 61.3 70.9 58.4 ND BD-109 18.3 22.9 18.2 17.6 17.5 17.9 ND ND ND ND 73.2 82.9 71.2 ND BD-110 14.5 19.2 12.4 14.2 12.7 14.0 ND ND ND ND 58.1 67.8 53.3 ND BD-111a 15.2 19.9 14.6 12.9 14.4 12.0 ND ND ND ND 60.9 70.6 53.9 ND BD-112 14.8 19.4 14.0 15.4 14.4 13.1 ND ND ND ND 61.9 71.5 56.9 ND BD-113a 15.7 20.3 14.5 14.7 14.7 13.9 ND ND ND ND 62.8 72.5 57.8 ND BD-114 15.4 20.0 14.9 15.9 14.7 15.1 ND ND ND ND 61.4 71.1 60.6 ND BD-115 15.5 20.1 15.3 18.3 14.3 15.4 ND ND ND ND 61.9 71.6 63.3 ND MDD0 = Quarterly Minimum Differential Dose = 4.63 mrem MDDA = Annual Minimum Differential Dose = 9.65 mrem ND = Not Detected, where Mo s (Bo+MDDo) or MA s (BA+MDDA)

Annual Radiologic~ Environm~tal Operating Report I YEAR: 2024 I

Page 80 of 81 Company: Constellation I Plant: Braidwood Station Units 1 and 2, Environmental Direct Radiation Dosimetry Results BD-116 16.1 20.8 15.6 14.9 15.8 16.3 ND ND ND ND 64.6 74.2 62.6 ND BD-201 18.5 23.2 19.1 19.3 19.2 19.1 ND ND ND ND 70.4 80.1 76.7 ND BD-202 15.6 20.2 15.7 14.5 14.5 14.0 ND ND ND ND 59.2 68.8 58.7 ND BD-203 15.3 20.0 13.8 14.1 14.8 16.7 ND ND ND ND 61.3 70.9 59.4 ND BD-204 14.5 19.1 13.3 14.7 12.7 13.9 ND ND ND ND 58.1 67.7 54.6 ND BD-205 14.8 19.5 15.1 14.1 13.2 14.7 ND ND ND ND 59.3 69.0 57.1 ND BD-206 15.4 20.1 15.1 15.3 14.3 15.7 ND ND ND ND 61.8 71.4 60.4 ND BD-207 14.4 19.0 14.5 13.9 14.2 12.4 ND ND ND ND 57.6 67.2 55.0 ND BD-208 15.3 19.9 15.4 15.2 14.5 12.9 ND ND ND ND 61.2 70.8 58.0 ND BD-209 19.9 24.5 18.4 18.9 19.0 17.9 ND ND ND ND 79.4 89.1 74.2 ND BD-210 17.3 21.9 16.9 17.8 15.9 18.2 ND ND ND ND 69.2 78.8 68.8 ND BD-211 19.8 24.4 20.7 21.8 18.8 19.1 ND ND ND ND 79.0 88.7 80.4 ND BD-212 17.9 22.5 15.4 15.8 13.7 15.6 ND ND ND ND 71.5 81.2 60.5 ND BD-213 14.3 18.9 13.1 15.9 14.6 11.2 ND ND ND ND 57.2 66.8 54.8 ND BD-214 16.8 21.4 16.5 16.0 16.7 19.4 ND ND ND ND 67.1 76.7 68.6 ND BD-215 14.9 19.6 15.7 15.1 14.4 13.6 ND ND ND ND 59.8 69.4 58.8 ND BD-216 17.4 22.1 15.3 17.1 17.2 16.8 ND ND ND ND 69.7 79.4 66.4 ND BD-06 15.0 19.7 12.2 15.5 12.9 14.8 ND ND ND ND 60.1 69.8 55.4 ND MDDa = Quarterly Minimum Differential Dose= 4.63 mrem MDDA = Annual Minimum Differential Dose = 9.65 mrem ND= Not Detected, where Ma~ (Ba+MDDa) or MA~ (BA+MDDA)

Annual Radiological Environmental Operating Report J_ YEAR: ~024 [

Page 81 of 81 Company: Constellation.

J Plant: Braidwood Station Units 1 and 2, Environmental Direct Radiation Dosimetry Results BD-19 16.4 21.1 16.4 17.9 15.1 17.2 ND ND ND ND 65.7 75.4 66.6 ND BD-20 16.1 20.7 16.4 16.8 14.1 16.0 ND ND ND ND 64.2 73.8 63.3 ND BD-21 15.5 20.1 15.9 16.5 15.0 15.6 ND ND ND ND 62.1 71.7 63.0 ND BD-ISFSl-104-3 15.7 19.8 14.8 15.0 13.9 12.8 ND ND ND ND 62.8 70.7 56.5 ND BD-ISFSl-104-4 15.7 19.8 17.5 20.8 18.5 19.5 ND 5.1 ND ND 62.8 70.7 76.3 13.5 BD-ISFSl-105-3 15.7 19.8 18.3 19.0 19.3 20.2 ND ND ND 4.5 62.8 70.7 76.8 14 BD-ISFSl-105-4 15.7 19.8 27.0 32.7 31.7 27.0 11.3 17.0 16.0 11.3 62.8 70.7 118.4 55.6 BD-ISFSl-110-3 15.7 19.8 62.5 64.0 60.5 61.4 46.8 48.3 44.8 45.7 62.8 70.7 248.4 185.6 BD-ISFSl-110-4 15.7 19.8 20.9 26.2 21.5 23.0 5.2 10.5 5.8 7.3 62.8 70.7 91.6 28.8 MDD0 = Quarterly Minimum Differential Dose= 4.63 mrem MDDA = Annual Minimum Differential Dose = 9.65 mrem ND = Not Detected, where Mo s (Bo+MDDo) or MA s (BA+MDDA)

Intentionally left blank

Constellation Braidwood Nuclear Power Station 2024 Annual Radiological Groundwater Protection Program Report Document Number: 50-456/50-457

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 1 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station TABLE OF CONTENTS 1.0 LIST OF ACRONYMS AND DEFINITIONS................................................................................ 2 2.0 NEI 07-07 ONSITE RADIOLOGICAL GROUNDWATER MONITORING PROGRAM................. 4 2.1 TABLES Voluntary Notification.................................................................................................... 13 Table 1, Groundwater Protection Program Monitoring Well Sampling Locations.................................... 4 Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma)................................................................................................................................... 7 Table 3, Groundwater Protection Program Monitoring Well Gamma Isotopic in Groundwater Samples (pCi/L +/- 2 sigma)................................................................................................................................. 11 Table 4, Groundwater Protection Program Monitoring Well Hard-To-Detects in Groundwater Samples (pCi/L +/- 2 sigma)................................................................................................................................. 12 FIGURES Figure 1, Groundwater Monitoring Well Sample Locations Braidwood Station, 2024............................. 6

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 2 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station 1.0 LIST OF ACRONYMS AND DEFINITIONS

1.

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.

2.

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

3.

Counting Error: An estimate of the two-sigma uncertainty associated with the sample results based on total counts accumulated.

4.

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

5.

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

6.

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

7.

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.

8.

LLD: Lower Limit of Detection. 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.

9.

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 5% probability of falsely concluding that a blank observation represents a true signal.

10.

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

11.

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

12.

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

13.

millirem (mrem): 1/1000 rem; a unit of radiation dose equivalent in tissue.

14.

Milliroentgen (mR): 1/1000 Roentgen; a unit of exposure to X-or gamma radiation.

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 3 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station

15.

N/A: Not Applicable

16.

NEI: Nuclear Energy Institute

17.

NRC: Nuclear Regulatory Commission

18.

ODCM: Offsite Dose Calculation Manual

19.

Protected Area: A 10 CFR 73 security term is an area encompassed by physical barriers and to which access is controlled for security purposes. The fenced area immediately surrounding the plant and around ISFSI are commonly classified by the licensee as "Protected areas." Access to the protected area requires a security badge or escort.

20.

REMP: Radiological Environmental Monitoring Program

21.

Restricted Area: A 10 CFRR 20 defined term where access to which is limited by the licensee for the purpose of protecting individuals against undue risks from exposure to radiation and radioactive materials.

22.

TRM: Technical Requirements Manual

23.

TS: Technical Specification

24.

Unrestricted Area: An area, access to which is neither limited nor controlled by the licensee.

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 4 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station 2.0 NEI 07-07 ONSITE RADIOLOGICAL GROUNDWATER MONITORING PROGRAM Braidwood Nuclear Power Station has developed a Groundwater Protection Initiative (GPI) program in accordance with NEI 07-07, Industry Ground Water Protection Initiative - Final Guidance Document [1]. 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. During 2024, Braidwood Station collected and analyzed groundwater samples in accordance with the requirements of approved procedures following regulatory methods..

This section is included in this report to communicate results of NEI 07-07 Radiological Groundwater Monitoring Program. Monitoring wells installed as part of GPI program are sampled and analyzed as summarized in Table 1, Groundwater Protection Program Monitoring Well Sampling Locations. In addition to reporting results from NEI 07-07 monitoring wells, voluntary communications to offsite governmental agencies for onsite leaks or spills per NEI 07-07 Objective 2.2, are also reported as part of this report. It is important to note, samples and results taken in support of NEI 07-07 groundwater monitoring program are not part of the Radiological Environmental Monitoring Program (REMP) but are reported as an attachment to the AREOR.

Table 1, Groundwater Protection Program Monitoring Well Sampling Locations Site Site Type 0WM31P Drinking Water MW-2 Monitoring Well MW-4 Monitoring Well MW-5 Monitoring Well MW-6 Monitoring Well MW-7 Monitoring Well MW-9 Monitoring Well MW-11 Monitoring Well MW-102R Monitoring Well MW-1410 Monitoring Well MW-142D Monitoring Well MW-143D Monitoring Well MW-144D Monitoring Well MW-145D Monitoring Well MW-154 Background Well MW-155 Background Well MW-159D Monitoring Well MW-162D Monitoring Well MW-BW-201S Monitoring Well

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 5 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Table 1, Groundwater Protection Program Monitoring Well Sampling Locations Cont'd Site Site Type MW-BW-202S Monitoring Well MW-BW-203S Monitoring Well MW-BW-207I Monitoring Well PS-7 Monitoring Well PS-8 Monitoring Well PS-9 Monitoring Well PS-10 Monitoring Well PS-11 Monitoring Well PS-12 Monitoring Well PS-13 Monitoring Well PS-14 Monitoring Well PS-15 Monitoring Well RW-6 Recovery Well RW-11 Recovery Well RW-12 Recovery Well VB1-1 Monitoring Well VB2-5DR Monitoring Well VB3-2 Monitoring Well VB5-2 Monitoring Well VB6-1 Monitoring Well VB7-1 Monitoring Well VB6-1 Monitoring Well VB7-1 Monitoring Well VB8-2R Monitoring Well VB9-1 Monitoring Well VB10-1R Monitoring Well VB11-1 Monitoring Well

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Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 7 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Radiological Groundwater Monitoring Program tritium results are summarized in Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma). No groundwater monitoring locations had detectable gamma or HTD in 2024.

Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma)

Site Collection Date H-3 Sr-89 Sr-90 MW-102R 2/15/2024

< 198

< 7

< 1.0 MW-102R 4/24/2024

< 193 MW-102R 9/26/2024

< 187 MW-102R 10/16/2024

< 197 MW-11 2/13/2024 320

+/-

134

< 10

< 0.9 MW-11 6/20/2024 304

+/-

130 MW-11 8/26/2024

< 180 MW-11 10/15/2024

< 184 MW-1410 2/14/2024 383

+/-

136

< 5

< 0.9 MW-142D 2/14/2024 508

+/-

139

< 7

< 0.9 MW-143D 2/14/2024 196

< 8

< 0.9 MW-144D 2/14/2024 533

+/-

143

< 8

< 0.9 MW-145D 3/5/2024 187

< 8

< 0.9 MW-145D 5/1/2024 191 MW-145D 7/24/2024 191 MW-145D 10/3/2024 183 MW-154 2/16/2024 195

< 6 1.0 MW-155 2/16/2024 195

< 8

< 0.9 MW-159D 2/13/2024 238

+/-

128

< 6

< 0.9 MW-162D 2/13/2024 322

+/-

131

< 9

< 0.9 MW-2 2/14/2024 848

+/-

172

< 7

< 0.9 MW-2 4/25/2024 479

+/-

135 MW-2 8/26/2024 262

+/-

121 MW-2 10/14/2024 218

+/-

122 MW-4 2/14/2024 378

+/-

133

< 8

< 1.0 MW-4 4/22/2024 473

+/-

136 MW-4 8/29/2024 341

+/-

121 MW-4 10/14/2024 336

+/-

131 MW-5 2/14/2024 415

+/-

136

< 6 1.0 MW-5 4/25/2024 285

+/-

128 MW-5 9/11/2024 394

+/-

125 MW-5 10/14/2024 186 MW-6 2/14/2024 701

+/-

156

< 5 1.0 MW-6 4/25/2024 258

+/-

136 MW-6 8/29/2024 596

+/-

136

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 8 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma) Cont'd Site Collection Date H-3 Sr-89 Sr-90 MW-7 2/14/2024 543

+/-

142

< 7

< 1.0 MW-7 4/25/2024 398

+/-

134 MW-7 8/29/2024 383

+/-

125 MW-7 10/15/2024 288

+/-

127 MW-9 8/30/2024

< 189 MW-BW-1410 4/25/2024 325

+/-

127 MW-BW-1410 8/28/2024 476

+/-

131 MW-BW-141D 10/14/2024 312

+/-

130 MW-BW-142D 4/25/2024 621

+/-

143 MW-BW-142D 8/29/2024 588

+/-

143 MW-BW-142D 10/14/2024 584

+/-

142 MW-BW-143D 4/23/2024

< 188 MW-BW-143D 8/29/2024

< 189 MW-BW-143D 10/14/2024

< 188 MW-BW-144D 4/25/2024 738

+/-

154 MW-BW-144D 8/28/2024 348

+/-

132 MW-BW-144D 10/14/2024 291

+/-

129 MW-BW-154 4/26/2024 184 MW-BW-154 9/27/2024 183 MW-BW-154 10/16/2024 187 MW-BW-155 4/26/2024 200 MW-BW-155 9/27/2024 189 MW-BW-155 10/16/2024 186 MW-BW-159D 4/25/2024 189 MW-BW-159D 8/26/2024 182 MW-BW-159D 10/18/2024 183 MW-BW-162D 4/22/2024 401

+/-

131 MW-BW-162D 9/12/2024 272

+/-

123 MW-BW-162D 10/15/2024 222

+/-

125 MW-BW-201S 2/14/2024 262

+/-

130

< 8

< 0.9 MW-BW-201S 4/22/2024

< 194 MW-BW-201S 9/11/2024

< 187 MW-BW-201S 10/15/2024

< 187 MW-BW-2021 8/30/2024

< 185 MW-BW-202S 2/14/2024 249

+/-

132

< 9

< 1.0

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 9 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma) Cont'd Site Collection Date H-3 Sr-89 Sr-90 MW-BW-202S 4/22/2024

< 190 MW-BW-202S 8/29/2024

< 183 MW-BW-202S 10/15/2024

< 197 MW-BW-2031 8/30/2024

< 192 MW-BW-203S 2/13/2024

< 194

< 8

< 0.9 MW-BW-203S 4/22/2024 258

+/-

126 MW-BW-203S 8/29/2024

< 184 MW-BW-203S 10/15/2024

< 191 MW-BW-2071 2/14/2024 547

+/-

143

< 8

< 0.9 MW-BW-2071 4/25/2024 423

+/-

133 MW-BW-2071 9/11/2024 302

+/-

129 MW-BW-2071 10/14/2024 259

+/-

128 PS-10 2/15/2024

< 196

< 5

< 0.9 PS-10 4/24/2024

< 193 PS-10 9/26/2024

< 187 PS-10 10/17/2024

< 190 PS-12 2/15/2024

< 193

< 7 1.0 PS-12 4/24/2024

< 193 PS-12 9/26/2024

< 194 PS-12 10/17/2024

< 192 RW-6 2/15/2024

< 198

< 6 0.8 RW-6 4/24/2024

< 186 RW-6 9/27/2024

< 188 RW-6 10/16/2024

< 190 VB-11-1 10/3/2024

< 185 VB-5-2 10/3/2024

< 187 VB-6-1 10/3/2024

< 190 VB-7-1 10/3/2024

< 186 VBl-1 2/16/2024

< 193

< 8

< 0.8 VBl-1 4/26/2024 249

+/-

123 VBl-1 9/27/2024

< 191 VBl-1 10/16/2024

< 188 VB10-1R 3/5/2024

< 188

< 4

< 0.8 VB10-1R 5/1/2024

< 193

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 10 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma) Cont'd Site Collection Date H-3 Sr-89 Sr-90 VB10-1R 7/24/2024

< 193

< 5

< 1 VB10-1R 10/3/2024

< 189 VB11-1 3/5/2024

< 191 VB11-1 5/1/2024

< 193 VB11-1 7/24/2024

< 195 VB3-2 2/15/2024

< 198

< 7

< 0.9 VB3-2 5/11/2024

< 190 VB3-2 9/26/2024

< 185 VB3-2 10/17/2024

< 197 VB5-2 3/5/2024

< 189

< 3

< 0.9 VB5-2 5/1/2024

< 195 VB5-2 7/24/2024

< 191 VB6-1 3/5/2024

< 187

< 5

< 0.9 VB6-1 5/1/2024

< 195 VB6-1 7/24/2024

< 190 VB7-1 3/5/2024

< 189

< 4 0.9 VB7-1 5/1/2024

< 197 VB7-1 7/24/2024

< 195 VB8-2R 3/5/2024

< 189

< 5 1.0 VB8-2R 5/1/2024

< 192 VB8-2R 7/24/2024

< 189 VB8-2R 10/3/2024

< 184 VB9-1 3/5/2024

< 187

< 4 0.8 VB9-1 5/1/2024

< 197 VB9-1 7/24/2024

< 195 VB9-1 10/3/2024

< 184

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 11 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Table 3, Groundwater Protection Program Monitoring Well Gamma Isotopic in Groundwater Samples (pCi/L +/- 2 sigma)

No Groundwater Samples Analyzed for Gamma Isotopic in 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 12 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station Table 4, Groundwater Protection Program Monitoring Well Hard-To-Detects in Groundwater Samples (pCi/L +/- 2 sigma)

No Groundwater Samples Analyzed for Hard-To-Detects in 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 13 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station 2.1 Voluntary Notification During 2024, Braidwood Nuclear Power Station did not make a voluntary NEI 07-07 notification to State/Local officials, NRC, and to other stakeholders required by site procedures.

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 14 of 14 Company: Constellation I Plant: Braidwood Nuclear Power Station BIBLIOGRAPHY

[1] "NEI 07 Industry Ground Water Protection Initiative -

Final Guidance Document, Rev. 1,"

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

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

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

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

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

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

[6] "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.

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

Nuclear Regulatory Commission, 1987.

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

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

[9] Health Physics Society, [Online]. Available: http://hps.org/hpspublications/radiationfactsheets.html.

[Accessed 2020].

BW250020, Annual Radiological Environmental Operating Report

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