Text

2024 Annual Radiological Environmental Operation Report
	ML25122A164
Person / Time
Site:	Clinton
Issue date:	04/29/2025
From:	Krukowski A; Constellation Energy Generation
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	U-604832
	Download: ML25122A164 (1)
	v • d • e

Constellation Clinton Power Station 8401 Power Road Clinton IL 61727 U-604832 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461 10 CFR 50.36a

Subject:

Clinton Power Station 2024 Annual Radiological Environmental Operation Report Clinton Power Station is submitting the 2024 Annual Radiological Environmental Operation Report. This report is submitted in accordance with Technical Specification requirement 5.6.2, "Annual Radiological Environmental Operation Report," and covers the period from January 1, 2024, through December 31, 2024.

There are no regulatory commitments contained in this report.

Questions in regard to this letter may be directed to Mr. Mohamad Fakhreddine, Chemistry Manager, at 217-937-3200.

Respectfully, Krukowski, Andrew Andrew Krukowski Plant Manager Clinton Power Station Digitally signed by Krukowski, Andrew Date: 2025.04.29 06:56:17

-05'00'

Attachment:

Annual Radiological Environmental Operation Report cc:

Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety - Illinois Emergency Management Agency

U-604832

SUBJECT:

Clinton Power Station 2024 Annual Radiological Environmental Operation Report bee (with attachment):

A. Krukowski C. Wilson D. Hillinger C. Miller R. Johnston M. Fakhreddine D. Livingston

Annual Radiological Environmental Operating Report YEAR: 2024 Page O of 79

l 2024 Annual Radiological Environmental Operating Report Document Number: 50-461

Annual Radiological Environmental Operating Report YEAR: 2024 Page 1 of 79 1---------~~----~---------~------~-

C om an : Constellation Plant: Clinton Clean Ener Center TABLE OF CONTENTS 1.0 LIST OF ACRONYMS AND DEFINITIONS................................................................................ 3 2.0 EXECUTIVE

SUMMARY

............................................................................................................ 5 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.............................................................................................. 14 7.0 REPORTING LEVELS FOR RADIOACTIVITY CONCENTRATIONS IN ENVIRONMENTAL SAMPLES................................................................................................. 18 8.0 SAMPLING PROGRAM, PROGRAM MODIFICATION AND INTEPRETATION OF RESULTS................................................................................................................................ 19 8.1 Environmental Direct Radiation Dosimetry Results....................................................... 19 8.2 Air Particulate and Radioiodine Sample Results........................................................... 20 8.3 Waterborne Sample Results......................................................................................... 21 8.4 Ingestion Pathway Sample Results............................................................................... 22 9.0 LAND USE CENSUS............................................................................................................... 23 10.0 SAMPLE DEVIATIONS, ANOMALIES AND UNAVAILABILITY................................................ 24 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...................... 9 Table 3, Radiological Environmental Sampling Program - Exposure Pathway-Waterborne............... 10 Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion................... 11 Table 5, REMP Sampling Locations - Direct Radiation........................................................................ 12 Table 6, Reporting Levels for Radioactivity Concentrations in Environmental Samples....................... 18 Table 7, Maximum Values for the Limit of Detection............................................................................ 18 Table 8, Land Use Census - Nearest Receptors within 5 miles........................................................... 24 Table 9: Sample Deviation Summary................................................................................................... 25 Table 10: Clinton Station Data Summary Table................................................................................... 30 Table 11, Weekly Air Particulate Gross Beta (E-3 pCi/m3).................................................................... 37 Table 12, Quarterly Air Particulate Gamma Isotopic (pCi/m 3 +/- 2 Sigma)............................................... 40 Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3)..................................................................................... 43 Table 14, Monthly/Bi-Weekly Milk 1-131 (pCi/L +/- 2 Sigma)................................................................... 46 Table 15, Monthly/Bi-Weekly Milk Gamma Isotopic (pCi/L +/- 2 Sigma)................................................. 47 Table 16, Annual Vegetation Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)................................................ 48 Table 17, Bi-weekly Grass Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)................................................... 51 Table 18, Monthly Surface Water lodine-131 (pCi/L +/- 2 Sigma)........................................................... 55

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 2 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 19, Monthly Surface Water Gamma Isotopic (pCi/L +/- 2 Sigma).................................................. 56 Table 20, Quarterly Surface Water Tritium (pCi/L +/- 2 Sigma).............................................................. 60 Table 21, Monthly Drinking Water Gross Beta and 1-131 (pCi/L +/- 2 Sigma)......................................... 61 Table 22, Monthly Drinking Water Gamma Isotopic (pCi/L +/- 2 Sigma)................................................. 62 Table 23, Quarterly Drinking Water Tritium (pCi/L +/- 2 Sigma).............................................................. 63 Table 24, Quarterly Groundwater Tritium (pCi/L +/- 2 Sigma)................................................................. 64 Table 25, Quarterly Ground Water Gamma Isotopic (pCi/L +/- 2 Sigma)................................................ 65 Table 26, Semi-Annual Fish Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)................................................. 66 Table 27, Semi-Annual Shoreline Sediment Gamma Isotopic (pCi/kg Dry+/- 2 Sigma)......................... 68 Table 28: Analytics Environmental Radioactivity Cross Check Program.............................................. 72 Table 29: DOE's Mixed Analyte Performance Evaluation Program (MAPEP)...................................... 74 Table 30: ERA Environmental Radioactivity Cross Check Program..................................................... 76 FIGURES Figure 1, Potential exposure pathways to Members of the Public due to Plant Operations [7]............... 6 Figure 2, Environmental Sampling Locations Within One Mile of the Clinton Power Station, 2024....... 14 Figure 3, Environmental Sampling Locations Between One and Two Miles of the Clinton Power Station, 2024 *************************************............................................................................................................... 15 Figure 4, Environmental Sampling Locations Between Two and Five Miles of the Clinton Power Station, 2024 ********************************************************************************************************** **************************************.... 16 Figure 5, Environmental Sampling Locations Greater Than Five Miles of the Clinton Power Station, 2024 **************** ************************************... *............................................................................................ 17 Figure 6, Air Particulate: Analysis for Gross Beta, Average for All Indicator vs. Control Location......... 20 ATTACHMENTS, Data Table Summary.................................................................................................... 30, Complete Data Table for All Analysis Results Obtained In 2024................................... 37, Cross Check lntercomparison Program......................................................................... 69, Environmental Direct Radiation Dosimetry Results....................................................... 77

Annual Radiological Environmental Operating Report YEAR: 2024 Page 3 of 79 Com an : Constellation Plant: Clinton Clean Ener Center 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 79 Company: Constellation I Plant: Clinton Clean Enerav Center

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 x10 6 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

Annual Radiological Environmental Operating Report

\\ YEAR: 2024 \\

Page 5 of 79 Company: Constellation

\\ Plant: Clinton Clean Energy Center 2.0 EXECUTIVE

SUMMARY

2.1 Clinton Clean Energy Center 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 Clinton 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.

The Annual Radiological Environmental Operating Report (AREOR) provides data obtained through analyses of environmental samples collected at Clinton Station for the reporting period of January 1st through December 31st, 2024. During that time period 1,573 analyses were performed on 1,447 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 Clinton Station, did not result in detection of plant related radionuclides in the environment.

Summary of

Conclusions:

No measurable activities above background levels were detected. All values were consistent with historical results which indicate no adverse radiological environmental impacts associated with the operation of Clinton 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. Pre-operational Radiological Environmental Monitoring Program (pre-operational REMP) was conducted to establish background radioactivity levels prior to operation of the Station. The environmental media sampled and analyzed during the pre-operational REMP were atmospheric radiation, fall-out, domestic water, surface water, marine life, milk, and vegetation. The results of the monitoring were detailed in the report entitled, Environmental Radiological Monitoring for Clinton Power Nuclear Power Station, Illinois Power Company, Annual Report 1987, May 1988. 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 YEAR: 2024 Page 6 of 79

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].

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- - - - Agricultural product.

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Soil 0

Liquid emuents

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 Illinois, Clinton 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 I YEAR: 2024 I

Page 7 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 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 Clinton Clean Energy Center, also known as Clinton Power Station, (CPS),

consisting of one approximately 1,120 MW gross electrical power output boiling water reactor is located in Harp Township, DeWitt County, Illinois. CPS is owned and operated by Constellation and became operational in 1987. Unit No. 1 went critical on February 27, 1987. The site encloses approximately 13,626 acres. This includes the approximately 4,900-acre, man-made cooling lake and about 95 acres of property not owned by Constellation. The plant is situated on approximately 150 acres. The cooling water discharge flume - which discharges to the eastern arm of the lake -

occupies an additional 130 acres. Although the nuclear reactor, supporting equipment and associated electrical generation and distribution equipment lie in Harp Township, portions of the aforementioned 13,626-acre plot reside within Wilson, Rutledge, DeWitt, Creek, Nixon and Santa Anna Townships.

Clinton 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, Environmental Sampling Locations Within One Mile of the Clinton Power Station, 2024 Figure 3, Environmental Sampling Locations Between One and Two Miles of the Clinton Power Station, 2024 Figure 4, Environmental Sampling Locations Between Two and Five Miles of the Clinton Power Station, 2024 Figure 5, Environmental Sampling Locations Greater Than Five Miles of the Clinton Power Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 8 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM REQUIREMENTS Table 1, Radiological Environmental Sampling Program - Exposure Pathway - Direct Radiation Sample Location Description, Sampling Requirement Collection/

Type and Frequency of Analyses Distance, and Direction Frequency Direct Radiation 54 DLRs 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.

Special interest areas representing special interest areas.

A supplemental set and a control

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 9 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 2, Radiological Environmental Sampling Program - Exposure Pathway - Airborne Sample Location Description, Sampling Requirement Distance, and Direction Collection/

Type and Frequency of Analyses Frequency CL-1 Camp Quest, 1.8 miles W CL-2 Clinton's Main Access Road, 0.7 miles NNE CL-3 Clinton's Secondary Access Road, One-week Airborne Radioiodine and Particulates 0.7 miles NE composite of Samples from 10 locations:

CL-4 Residence Near Recreation Area, continuous Particulate sampler: Gross Beta 0.8 miles SW air sampling analysis following weekly filter change Five locations close to the site boundary in different sectors CL-6 Clinton's Recreation Area, 0.7 miles through glass and Gamma isotopic quarterly on each of the highest calculated annual average ground level D/Q.

WSW fiber filter station.

CL-7 Mascoutin Recreation Area, 2.3 paper.

Four samples from the vicinity of a community having the miles SE One week Radioiodine canister: 1-131 analysis highest calculated annual average D/Q.

composite of CL-8 DeWitt Cemetery, 2.2 miles E continuous weekly on near field and control One samples from Control Locations between 4 - 8 miles air sampling samples.

away in the least predominant wind direction.

CL-11 Illinois Power Substation (C), 16 through milesS charcoal filter CL-15 Rt. 900N Residence, 0.9 miles N CL-94 Old Clinton Road, 0.6 miles E

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 10 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne Requirement Sample Location Description, Distance, Sampling Collection/ Frequency Type and Frequency of and Direction Analyses CL-13 Salt Creek Bridge on Rt. 10, 3.6 miles SW Surface Water CL-90 Discharge Flume, 0.4 miles SE Monthly grab and composite from Gamma isotopic Monthly Two samples upstream CL-91 Parnell Boat Access (C), 6.1 miles a continuous water compositor.

1-131 Monthly (control) and two sample ENE Quarterly composite from a H-3 Quarterly downstream continuous water compositor CL-99 North Fork Access (C), 3.5 miles NNE Drinking (Potable) Water CL-14 Station Plant Service Bldg, Onsite Monthly and quarterly composite Gamma isotopic Monthly One of sample downstream from a continuous water Gross Beta Monthly (indicator) compositor H-3 Quarterly Groundwater/Well Water CL-7D Mascoutin Recreation Area, 2.3 miles Gamma isotopic Three indicator locations ESE Quarterly composite from a Quarterly down gradient from the plant, CL-12T DeWitt Pump House, 1.6 miles E continuous water compositor H-3 Quarterly only if likely to be affected.

CL-12R DeWitt Pump House, 1.6 miles E Sediment from Shoreline One sample upstream CL-7B Clinton Lake, 2.1 miles SE Semiannual grab samples Gamma isotopic (control) and one sample CL-105 Lake Shelbyville(C), 50 miles S Semiannually downstream (indicator)

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 11 of 79 Company: Constellation I Plant: Clinton Clean Enercw Center Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion Requirement Sample Location Description, Distance, and Sampling Collection/

Type and Frequency Direction Frequency of Analyses Milk Bi-weekly grab samples One of sample from milking animals when cows are on Gamma isotopic and I-at a control location 15 to 30 km CL-116 Dement Dairy (C), 14 miles WSW pasture.

131 analysis on each distant and in the least prevalent sample wind direction.

Monthly all other times Fish One sample upstream and one CL-19 End of Discharge Flume, 3.4 miles E Gamma isotopic sample downstream of each CL-105 Lake Shelbyville(C), 50 miles S Semiannually analysis on edible commercially and recreationally portions important species in vicinity of site discharge.

Vegetation CL-114 Residence WSW of Site (C), 12.5 miles Two locations producing vegetables WSW Gamma isotopic on from areas irrigated by water in CL-115 Site's Secondary Access Road, 0.7 miles Monthly grab June each sample which liquid plant wastes have been NE through September Gross Beta on each discharged and one sample CL-118 Site's Main Access Road, 0.7 miles NNE sample collected from a control location.

Grass Four locations from areas irrigated CL-1 Camp Quest, 1.8 miles W by water in which liquid plant wastes CL-2 Clinton's Main Access Road, 0.7 miles NNE Bi-weekly May through Gamma isotopic on have been discharged and one CL-8 DeWitt Cemetery, 2.2 miles E October each sample sample collected from a control CL-116 Pasture in Rural Kenney (C), 14 miles WSW location.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 12 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center Table 5, REMP Sampling Locations - Direct Radiation Site#

Location Sector Distance Description Type CL-1 Inner Ring w

1.8 miles CL-5 Inner Ring NNE 0.7 miles CL-22 Inner Ring NE 0.6 miles CL-23 Inner Ring ENE 0.5 miles CL-24 Inner Ring E

0.5 miles CL-34 Inner Ring WNW 0.8 miles CL-35 Inner Ring NW 0.7 miles CL-36 Inner Ring N

0.6 miles CL-42 Inner Ring ESE 2.8 miles CL-43 Inner Ring SE 2.8 miles CL-44 Inner Ring SSE 2.3 miles CL-45 Inner Ring s

2.8 miles CL-46 Inner Ring SSW 2.8 miles CL-47 Inner Ring SW 3.3 miles CL-48 Inner Ring WSW 2.3 miles CL-63 Inner Ring NNW 1.3 miles CL-51 Outer Ring NW 4.4 miles CL-52 Outer Ring NNW 4.3 miles CL-53 Outer Ring E

4.3 miles CL-54 Outer Ring ESE 4.6 miles CL-55 Outer Ring SE 4.1 miles CL-56 Outer Ring SSE 4.1 miles CL-57 Outer Ring s

4.6 miles CL-58 Outer Ring SSW 4.3 miles CL-60 Outer Ring SW 4.5 miles CL-61 Outer Ring WSW 4.5 miles CL-76 Outer Ring N

4.6 miles CL-77 Outer Ring NNE 4.5 miles

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 13 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 5, REMP Sampling Locations - Direct Radiation Site#

Location Sector Distance Description Type CL-78 Outer Ring NE 4.8 miles CL-79 Outer Ring ENE 4.5 miles CL-80 Outer Ring w

4.1 miles CL-81 Outer Ring WNW 4.5 miles CL-37 Special Interest N

3.4 miles CL-41 Special Interest E

2.4 miles CL-49 Special Interest w

3.5 miles CL-64 Special Interest WNW 2.1 miles CL-65 Special Interest ENE 2.6 miles CL-74 Special Interest w

1.9 miles CL-75 Special Interest N

0.9 miles CL-2 Supplemental NNE 0.7 miles CL-3 Supplemental NE 0.7 miles CL-4 Supplemental SW 0.8 miles CL-6 Supplemental WSW 0.8 miles CL-7 Supplemental SE 2.3 miles CL-8 Supplemental E

2.2 miles CL-15 Supplemental N

0.9 miles CL-33 Supplemental SW 11.7 miles CL-84 Supplemental E

0.6 miles CL-90 Supplemental SE 0.4 miles CL-91 Supplemental ENE 6.1 miles CL-97 Supplemental SW 10.3 miles CL-99 Supplemental NNE 3.5 miles CL-114(1)

Supplemental WSW 12.5 miles CL-11 Control s

16 miles

<1l The location for CL-114 changed at the beginning of 2023 due to a change In control garden location In 2022. CL-1 14 Is a supplemental DLR and a 5-year baseline is being gathered before facility-related dose calculations can be performed. 2023 will be the first full year of a baseline data collection.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 14 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 6.0 MAPS OF COLLECTION SITES.

Figure 2, Environmental Sampling Locations Within One Mile of the Clinton Power Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 15 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Figure 3, Environmental Sampling Locations Between One and Two Miles of the Clinton Power Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 16 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Figure 4, Environmental Sampling Locations Between Two and Five Miles of the Clinton Power Station, 2024

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 17 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Figure 5, Environmental Sampling Locations Greater Than Five Miles of the Clinton Power Station, 2024

Annual Radiological Environmental Operating Report YEAR: 2024 Page 18 of 79 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/m 3) 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)

H-3 2,000 (J)

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 (4) 0.07 NA 1

60 Cs-134 15 0.05 130 15 60 Cs-137 18 0.06 150 18 80 Ba-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/I may be used NA NA NA NA NA NA NA 150 180 NA 3 If no drinking water pathway exists, a value of 3,000 pCi/L may be used. Some states may require a lower LLD for drinking water sources-per 40 CFR 141 Safe drinking water ACT.

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

Annual Radiological Environmental Operating Report

\\ YEAR: 2024 I

Page 19 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 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 N 13.37-2014, 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 54 locations were monitored and data analyzed in accordance with the requirements in Table 1, Radiological Environmental Sampling Program - Exposure Pathway - Direct Radiation. Attachment 4, provides the annual direct radiation dosimetry analysis.

There was no direct radiation dose detected from the facility. All OSLO measurements were analyzed, and none were found to have radiation levels that had increased over normal background radiation levels.

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 20 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 520 samples were collected and analyzed for gross beta, gamma emitters and iodine. Particulate samplers are used to continuously collect airborne particulates on a filter. The samples are analyzed for gross beta activity following filter changeout which occurs weekly. Gamma isotopic analysis is also performed on the samples collected at each location and is analyzed quarterly. Radioiodine (1-131) analysis is performed weekly on radioiodine sample cartridges.

All gross beta analyses of air particulate filters detected gross beta activity 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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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 6, 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 6, and there were no significant changes.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 21 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 8.3 Waterborne Sample Results 8.3.1 Surface Water (i.e., Bay, Lake etc.)

Composite water samples are collected monthly at the upstream control location and at the downstream indicator locations. Monthly composite samples are analyzed for gamma emitters. Aliquots from the monthly composites are combined to form a quarterly composite which is then analyzed for tritium. During the calendar year 2024, a total of 16 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. Samples were analyzed for lodine-131 (Low Level). There was no detectable lodine-131 and all required LLDS were met. Samples were analyzed for gamma-emitting nuclides. No nuclides were detected and all required LLDs were met. Tritium concentrations in surface water were well below the EPA tritium drinking water limit of 20,000 pCi/L There has been no detectable tritium in any surface water samples in 2024 or the previous 10 years, therefore, no trend has been established above the detection limit to plot on a trending graph.

8.3.2 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 11 groundwater water samples wece 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 3 indicator sample locations were collected. These samples were analyzed for tritium and gamma quarterly. All groundwater samples were collected in new containers, 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. Tritium concentrations in groundwater were well below the EPA tritium drinking water limit of 20,000 pCi/L. 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.

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 22 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 8.3.3 Drinking Water A total of 12 drinking water samples were obtained in 2024. These samples were analyzed for gross beta, gamma, and 1-131 monthly and tritium quarterly, in accordance with requirements in the ODCM and shown in Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne. Gross Beta was not detected in any of the samples and all required LLDs were met. No gamma-emitting nuclides were detected and all required LLDs were met. Tritium concentrations in drinking water were well below the EPA tritium drinking water limit of 20,000 pCi/L. There has been no detectable tritium in any REMP drinking water samples in 2024 or in the previous 10 years, therefore, no trend has been established above the detection limit to plot on a trending graph.

8.3.4 Sediment from Shoreline Shoreline sediment collections were made in May and September, 2024 and analyzed for gamma-emitting isotopes. Samples are collected at both indicator and control locations. A total of 4 shoreline samples were analyzed in accordance with requirements in the ODCM and shown in Table 3, Radiological Environmental Sampling Program - Exposure Pathway - Waterborne No nuclides potentially associated with Clinton Station were detected and all required LLDs were met.

8.4 Ingestion Pathway Sample Results 8.4.1 Milk Milk samples from milking animals were collected at 1 location within 5 km having the highest dose potential. Samples were collected January-December. Samples were analyzed for gamma-emitting isotopes and 1-131 (Low Level}.

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

8.4.2 Fish A total of 16 fish samples were collected in 2024. These samples were analyzed for gamma emitting radionuclides in edible portions, in accordance with requirements of the ODCM and summarized in Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion. These samples are collected from the indicator and control areas as required by the ODCM.

Naturally occurring potassium-40 was identified in all fish samples with concentrations consistent with previous years.

Annual Radiological Environmental Operating Report YEAR: 2024 Page 23 of 79 8.4.3 Vegetation A total of 34 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 nuclides potentially associated with Clinton Station were detected and all required LLDs were met.

8.4.4 Grass In accordance with the ODCM and as described in Table 4, Radiological Environmental Sampling Program - Exposure Pathway - Ingestion, 48 grass samples were collected from growing locations nearest site boundary in areas of highest predicted annual average ground level D/Q. Samples are collected and analyzed for gamma isotopic from the indicator and control locations biweekly May through October.

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

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 8 km (5 mi.) the location in each of the 16 meteorological sectors of the nearest milk animal, the nearest residence and the nearest garden of greater than 50 m2 (500 ft2) producing broad leaf vegetation. Note, per NUREG-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 5 miles. In summary, the highest D/Q locations for nearest garden, nearest residence and nearest milk animal did not change following the 2024 census

--f

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 24 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center I

Table 8, Land Use Census - Nearest Receptors within 5 miles I

Sector Direction Residence Milk Farm Livestock (Miles)

(Miles)

A N

0.9 0.9 0.9 B

NNE 0.9 1.1 C

NE 1.3 D

ENE 1.8 E

E 1.0 F

ESE 3.2 G

SE 2.4 H

SSE 1.8 J

s 3.0 K

SSW 2.9 L

SW 0.7 M

WSW 2.2 2.7 N

w 1.2 p

WNW 1.6 Q

NW 1.6 2.4 R

NNW 1.3 1.3 10.0 SAMPLE DEVIATIONS, ANOMALIES AND UNAVAILABILITY Sampling and analysis are performed for media types addressed in the Offsite Dose Calculation Manual. Sampling and analysis challenges may be experienced due to a multitude of reasons including environmental factors, loss of TLDs/OSLDs, contamination of samples, etc. To aid classification of sampling and analysis challenges experienced in 2024, the following three terms are used to describe the issues: Sample Anomalies, Sample Deviation, and Unavailable Samples.

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

"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:

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 25 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 9: Sample Deviation Summary Collection Reason for not conducting REMP Plans for preventing Sample Type Location Date or Period sampling as required by ODCM reoccurrence Four air samplers were found with approximately 4-5 hours missing from the collection timer. The less than expected sample collection time AP CL-7, CL-8, CL-15, 01/03/2024 indicates a brief loss of power in the and CL-94 area. Affected air samplers include ODCM sample locations CL-8 and CL-15, as well as supplemental ODCM sample locations CL-7 and CL-94. (IR 04736473)

Gross-beta analysis for air sampler CL-4 indicated no activity was detected. The sample collection sheet indicated the sampler flow rate was within the procedural requirement, however, upon further investigation, the CL-4 particulate 03/27/24-filter paper appeared to be damaged and AP CL-4 04/03/24 torn. Due to the filter appearance and low activity identified, the validity of sample collection is suspect and does not appear to be representative for the collection period. CL-4 is a non-ODCM required, supplemental air sampler. This was marked as a missed sample.

(IR 04765877)

Air sampler CL-1 was found with a short collection timer. The timer recorded 162.7 hours8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months of collection time, indicating AP CL-1 04/24/2024 a short power outage during the collection week. CL-1 is a non-ODCM required, supplemental air sampler. (IR 04773743)

Air sampler collection timers were missing hours from the collection period, 04/17 /2024-indicating a short power outage in the AP CL-1 04/24/2024 area. CL-1 is a non-ODCM required, supplemental air sampler and was missing approximately 7.4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months of collection. (IR 04778746)

Air sampler collection timers were missing hours from the collection period, indicating a short power outage in the area. CL-4 is a non-ODCM required, AP CL-3 and CL-4 05/15/2024-supplemental air sampler and was 05/22/2024 missing approximately 16.2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of collection CL-3 is an ODCM required air sampler and was missing approximately 4.2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of collection.

(IR 04778746)

Two air samplers were found with approximately 1.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months missing from the collection timer. The less than AP CL-4 and CL-6 08/07/2024 expected sample collection time indicates a brief loss of power in the area. Affected air samplers include non-ODCM required, supplemental air samplers CL-4 and CL-6. (IR 04792335)

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 26 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 The REMP vendor identified electrical work being performed near CL-7. The vendor stated that the power was out during the sample collection, so the flow rate and Vmax were estimated based on previous week's values. The samples AP CL-7 08/28/2024-were collected and the filter media was 09/04/2024 exchanged as normal. Collection timer was unavailable for reading, and utility worker stated power would be returned to the air sampler later that same day, causing collection to be short a couple hours. CL-7 collection timer was short by approximately 1.4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . (IR 04798678)

Air sampler CL-1 collection timer was missing approximately 5-6 hours for the AP CL-1 08/28/2024-collection, indicating a brief power 09/04/2024 outage in the area. CL-1 is a non-ODCM required, supplemental air sampler.

(IR 04803884)

The REMP sampling vendor identified CL-57 OSLDs and holder were missing, likely caused by mowing activities in the area. CL-57 is an ODCM-required sampling location and is located in the outer ring of dosimeters at 4.6 miles S of OSLO CL-57 09/18/2024 the station. CL-57 was present at the location during the August monthly visual check, and the amount of time the OSLO has been missing during the month of September is unknown. This was marked as a missed sample.

(IR 04802846)

It was identified that the amount of vegetation collected at CL-118 was not of adequate size to reach the Vegetation CL-118 09/25/2024 requirement of 1 kg. Brush and tree overgrowth in the area has led to decreased amounts of sunlight which could be preventing vegetation growth.

(IR 04804779)

There was a labeling discrepancy for the iodine and particulate samples at REMP locations CL-3 and CL-4. The particulate filters from both locations were originally labeled as collected from CL-3 with one AP and Charcoal CL-3 and CL-4 10/23/2024 of samples later corrected from CL-3 to CL-4. The charcoal cartridges from both locations were labeled as CL-4.

Determining which charcoal cartridge was labeled correctly could not be determined. (IR 04813077)

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 27 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 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 During the weekly compositor walkdowns in October, it was identified that the hose connected to surface water compositor CL-99 had washed up on the bank and was not able to collect a Surface Water CL-99 10/02/2024 sample. A grab sample was collected for the week in place of the composite sample. The monthly surface water sample for the month of November required a grab sample due to low water level in the creek. (IR 04811494)

Non-ODCM required, supplemental air sampler CL-6 collection timer recorded approximately 2.6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months less than the AP CL-6 12/18/2024 weekly expected collection time due to the pump requiring minor maintenance in the field. The missing time corresponds to the time the pump was down for maintenance. (IR 04824580)

The REMP sampling vendor was unable The sample collection to collect the quarterly ground water was rescheduled to Groundwater CL-7D 12/31/2024 sample at CL-7D due to the park building January 2nd, 2025, and being locked for the holiday.

the sample was able to (IR 04827058) be successfully obtained at that time.

During 2024, the drinking water Weekly grab samples compositor located at CL-14 was non-were obtained from this Drinking Water CL-14 2024 functional due to issues overcoming the location and composited pressurized drinking water system for the monthly and causing leaks from the compositor.

quarterly analyses.

11.0 OTHER SUPPLEMENTAL INFORMATION 11.1 NEI 07-07 Onsite Radiological Groundwater Monitoring Program 11.2 Clinton Clean Energy Center 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 for onsite groundwater wells are provided in the ARERR.

Corrections to Previous Reports No corrections made in previous reports in 2024

Annual Radiological Environmental Operating Report YEAR: 2024 Page 28 of 79 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.

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

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

Nuclear Regulatory Commission, 1987.

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

Nuclear Regulatory Commission, Ocotober, 1977.

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

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

Annual Radiological Environmental Operating Report

\\ YEAR: 2024 \\

Page 29 of 79 Company: Constellation I Plant: Clinton Clean Energy Center

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

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

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

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

[26] "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 79 Company: Constellation I Plant: Clinton Clean Enerav Center, Data Table Summary Table 10: Clinton Station Data Summary Table Type, Total Number Lower Indicator Location with Highest Annual Mean Medium or of Analyses Limit of Means; Pathway Sampled (Units) performed Detection (f6).

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

(LLD)

Ranges Name (f6)

Distance and Direction Ranges CL-3 Gross Beta, 520 10 20 (467/468)

Clinton's Secondary Access 20 (52/52)

Road (7/36) 0.7 miles NE (9/36)

Co-60 N/A

< LLD

< LLD Nb-95 N/A

< LLD

< LLD Air Particulates Zr-95 N/A

< LLD

< LLD (E-03 pCi/m3)

Ru-103 N/A

< LLD

Gamma, Ru-106 N/A

< LLD

< LLD 40 Cs-134 50

< LLD

< LLD Cs-137 60

< LLD

< LLD Ce-141 N/A

< LLD

< LLD Ce-144 N/A

< LLD

< LLD Airborne Gamma, 520 Radioiodine 70

< LLD

< LLD (E-03 pCi/m3) 1-131 Direct Radiation Gamma Dose, 215 N/A 18.6 (211 /211)

CL-49 20.8 (4/4)

(mrem/qtr.)

(11.9/23.3) 3.5 miles W (20.2/21.9) 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 20 (52/52)

(7/35)

< LLD

< LLD N/A 17.3 (4/4)

(13.9/18.8)

Number of Nonroutine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 31 of 79 Company: Constellation I Plant: Clinton Clean Energy Center, Data Table Summary Table 10: Clinton Station Data Summary Table Type, Total Number Lower Indicator Location with Highest Annual Mean Medium or Pathway of Analyses Limit of Means; Sampled (Units) performed Detection (f6).

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

(LLD)

Ranges Name (f6)

Distance and Direction Ranges l-131(Low Level), 19 1

< LLD

< LLD CL-116 K-40 N/A N/A Dement Dairy 1074 (19/19) 14 miles WSW (883/1252)

Mn-54 N/A N/A

< LLD

< LLD Co-58 N/A N/A

< LLD

< LLD Fe-59 N/A N/A

< LLD

< LLD Milk Co-60 N/A N/A

< LLD

< LLD (pCi/L)

Gamma, Zn-65 N/A N/A

< LLD

< LLD 19 Nb-95 N/A N/A

< LLD

< LLD Zr-95 N/A N/A

< LLD

< LLD Cs-134 15 N/A

< LLD

< LLD Cs-137 18 N/A

< LLD

< LLD Ba-140 60 N/A

< LLD

< LLD La-140 15 N/A

< LLD

< LLD Ce-144 N/A N/A

< 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

< LLD 1074 (19/19)

(883/1252)

< LLD

< LLD Number of Nonroutine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 32 of 79 Company: Constellation I Plant: Clinton Clean EnerC1v Center, Data Table Summary Table 1 o* Clinton Station Data Summarv Table Type, Total Lower Indicator Location with Highest Annual Mean Medium or Number of Limit of Means; Pathway Analyses Detection (f6).

Means Sampled (Units) performed (LLD)

Name (f6)

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

Ranges Distance and Direction Ranges 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) 34 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 Ce-144 N/A

< 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 Grass

Gamma, Nb-95 N/A

< LLD

< LLD (pCi/kg Wet) 48 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 Ce-144 N/A

< 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

< LLD

< LLD Number of Nonroutine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report YEAR: 2024 Page 33 of 79, Data Table Summary Table 10: Clinton Station Data Summary Table Type, Total Number Lower Indicator Location with Highest Annual Mean Medium or of Analyses Limit of Means; Pathway Sampled performed Detection (f6).

Name Means (Units)

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

(LLD)

Ranges Distance and Direction (f6)

Ranges 1-131 (Low Level),

1

< LLD

< LLD 12 H-3, 16 200

< LLD

< LLD Mn-54 15

< LLD

< LLD Co-58 15

< LLD

< LLD Surface Water Fe-59 30

< LLD

< LLD (pCi/L)

Co-60 15

< LLD

< LLD Zn-65 30

< LLD

Gamma, Nb-95 15

< LLD

< LLD 48 Zr-95 30

< LLD

< LLD Cs-134 15

< LLD

< LLD Cs-137 18

< LLD

< LLD Ba-140 60

< LLD

< LLD La-140 15

< LLD

< LLD Ce-144 N/A

< 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

< LLD

< LLD Number of Non routine Reported Measurements 0

0 0

0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 34 of 79 Company: Constellation I Plant: Clinton Clean Energy Center, Data Table Summary Table 1 O* Clinton Station Data Summary Table Type, Total Number Lower Indicator Location with Highest Annual Mean Medium or Pathway Sampled of Analyses Limit of Means; performed Detection (f6).

Name Means (Units)

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

(LLD)

Ranges Distance and Direction (f6)

Ranges 1-131 (Low Level),

1

< LLD

< LLD 12 Gross Beta, 12 4

< LLD

< LLD H-3, 4 200

< LLD

< LLD Drinking water Mn-54 15

< LLD

< LLD (pCi/L)

Co-58 15

< LLD

< LLD Fe-59 30

< LLD

< LLD Co-60 15

< LLD

< LLD Zn-65 30

< LLD

Gamma, Nb-95 15

< LLD

< LLD 12 Zr-95 30

< LLD

< LLD Cs-134 15

< LLD

< LLD Cs-137 18

< LLD

< LLD Ba-140 60

< LLD

< LLD La-140 15

< LLD

< LLD Ce-144 N/A

< 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 Mean5 (f6).

Ranges N/A N/A N/A

< LLD

< LLD Number of Nonroutine Reported Measurements 0

0 0

Annual Radiological Environmental Operating Report YEAR: 2024 Page 35 of 79, Data Table Summary Table 10: Clinton Station Data Summary Table Type, Total Number Lower Indicator Location with Highest Annual Mean Medium or of Analyses Limit of Means; Pathway Sampled Means (Units) performed Detection (f6).

Name (f6)

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

(LLD}

Ranges Distance and Direction Ranges H-3, 11 200

< LLD

< LLD Mn-54 15

< LLD

< LLD Co-58 15

< LLD

< LLD Fe-59 30

< LLD

< LLD Ground/Well Water Co-60 15

< LLD

< LLD (pCi/L)

Zn-65 30

< LLD

Gamma, Nb-95 15

< LLD

< LLD 11 Zr-95 30

< LLD

< LLD Cs-134 15

< LLD

< LLD Cs-137 18

< LLD

< LLD Ba-140 60

< LLD

< LLD La-140 15

< LLD

< LLD Ce-144 N/A

< LLD

< LLD Mn-54 130

< LLD

< LLD Co-58 130

< LLD

< LLD Fe-59 260

< LLD

< LLD Co-60 130

< LLD

< LLD Zn-65 260

< LLD

< LLD Fish

Gamma, Nb-95 N/A

< LLD

< LLD (pCi/kg Wet) 16 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 Ce-144 N/A

< 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 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 Nonroutine Reported Measurements 0

0 0

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 36 of 79 Company: Constellation I Plant: Clinton Clean EnerQy Center, Data Table Summary Table 10: Clinton Station Data Summary Table Type, Total Number Lower Indicator Location with Highest Annual Mean Medium or Pathway of Analyses Limit of Mean5; Means Sampled (Units) performed Detection (f6).

Name (t6)

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

(LLD)

Range5 Distance and Direction Ranges 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 Sediment Nb-95 N/A

< LLD

< LLD (pCi/kg Dry)

Gamma, 4 Zr-95 N/A

< LLD

< LLD Cs-134 150

< LLD

< LLD Cs-137 180

< LLD

< LLD Ba-140 N/A

< LLD

< LLD La-140 N/A

< LLD

< LLD Ce-144 N/A

< 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 (t6).

Ranges

< LLD

< LLD Number of Nonroutine Reported Measurements 0

0 0

0

Collection Date 01/03/2024 01/10/2024 01/17/2024 01/24/2024 01/31/2024 02/07/2024 02/14/2024 02/21/2024 02/28/2024 03/06/2024 03/13/2024 03/20/2024 03/27/2024 04/03/2024 04/10/2024 04/17/2024 04/24/2024 05/01/2024 05/08/2024 05/1 5/2024 05/22/2024 Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 37 of 79 CL-2 23

+/-

23

+/-

20

+/-

13

+/-

12

+/-

17

+/-

16

+/-

24

+/-

14

+/-

16

+/-

14

+/-

12

+/-

16

+/-

9

+/-

19

+/-

12

+/-

18

+/-

13

+/-

12

+/-

20

+/-

12

+/-

Company: Constellation I Plant: Clinton Clean Enerav Center 5

26 5

28 4

18 4

11 4

12 4

17 4

22 4

25 4

17 4

18 4

14 4

20 3

9 4

20 4

12 4

15 4

16 4

14 4

21 4

12, 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)

CL-3 CL-4 CL-6 CL-15 CL-94 CL-1 CL-7

+/-

5 26

+/-

5 25

+/-

5 25

+/-

5 26

+/-

5 28

+/-

5 24

+/-

5 28

+/-

5 29

+/-

5 25

+/-

5 29

+/-

5 26

+/-

5 28

+/-

4 20

+/-

4 16

+/-

4 20

+/-

4 17

+/-

4 18

+/-

4 18

+/-

3 13

+/-

4 15

+/-

4 13

+/-

4 11

+/-

3 13

+/-

4 11

+/-

4 18

+/-

4 19

+/-

4 9

+/-

4 15

+/-

4 15

+/-

4 17

+/-

4 22

+/-

4 22

+/-

4 17

+/-

4 20

+/-

4 19

+/-

4 19

+/-

4 21

+/-

4 22

+/-

4 22

+/-

4 24

+/-

5 20

+/-

4 22

+/-

4 24

+/-

4 23

+/-

4 25

+/-

5 24

+/-

4 23

+/-

4 24

+/-

4 18

+/-

4 19

+/-

4 18

+/-

4 18

+/-

4 18

+/-

4 16

+/-

4 21

+/-

4 17

+/-

4 17

+/-

4 15

+/-

4 14

+/-

4 18

+/-

4 15

+/-

4 16

+/-

4 18

+/-

4 15

+/-

4 16

+/-

4 18

+/-

4 15

+/-

4 13

+/-

4 13

+/-

4 10

+/-

4 14

+/-

4 12

+/-

4 5(1) 16

+/-

4 15

+/-

4 17

+/-

4 15

+/-

4 13

+/-

3 7

+/-

3 7

+/-

3 7

+/-

3 9

+/-

3 8

+/-

3 8

+/-

5 18

+/-

4 17

+/-

4 18

+/-

4 16

+/-

4 18

+/-

4 17

+/-

4 13

+/-

4 19

+/-

5 16

+/-

4 14

+/-

4 13

+/-

4 14

+/-

4 13

+/-

4 14

+/-

4 19

+/-

4 16

+/-

4 12

+/-

4 11

+/-

4 12

+/-

4 15

+/-

4 12

+/-

4 12

+/-

4 13

+/-

4 12

+/-

4 14

+/-

4 14

+/-

4 13

+/-

4 13

+/-

4 13

+/-

4 9

+/-

4 22

+/-

5 23

+/-

4 20

+/-

4 19

+/-

4 22

+/-

4 19

+/-

4 9

+/-

4 11

+/-

4 8

+/-

4 9

+/-

4 7

+/-

4 9

+/-

(1) See Sample Deviations Table CL-8 5

24

+/-

5 29

+/-

4 20

+/-

3 15

+/-

4 16

+/-

4 19

+/-

4 19

+/-

4 22

+/-

4 13

+/-

4 19

+/-

4 17

+/-

4 13

+/-

4 13

+/-

3 10

+/-

4 12

+/-

4 15

+/-

4 13

+/-

4 14

+/-

4 14

+/-

4 22

+/-

4 9

+/-

CL-11 5

26

+/-

5 5

23

+/-

5 4

19

+/-

4 4

13

+/-

4 4

13

+/-

4 4

19

+/-

4 4

24

+/-

4 4

22

+/-

4 4

18

+/-

4 4

20

+/-

4 4

16

+/-

4 4

12

+/-

4 4

15

+/-

4 4

7

+/-

3 4

13

+/-

4 4

14

+/-

4 4

16

+/-

4 4

14

+/-

4 4

13

+/-

4 4

19

+/-

4 4

8

+/-

4

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 38 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 11, Weekly Air Particulate Gross Beta (E-3 pCi/m3) Cont'd Collection CL-2 CL-3 CL-4 CL-6 CL-15 CL-94 CL-1 CL-7 CL-8 CL-11 Date 05/29/2024 13

+/-

4 14

+/-

4 17

+/-

4 16

+/-

4 15

+/-

4 17

+/-

4 14

+/-

4 14

+/-

4 16

+/-

4 15

+/-

4 06/05/2024 12

+/-

4 10

+/-

4 14

+/-

4 13

+/-

4 15

+/-

4 13

+/-

4 13

+/-

4 12

+/-

4 9

+/-

3 14

+/-

4 06/12/2024 15

+/-

4 16

+/-

4 18

+/-

4 20

+/-

5 19

+/-

5 18

+/-

5 17

+/-

4 15

+/-

4 21

+/-

5 13

+/-

4 06/1 9/2024 16

+/-

4 22

+/-

4 17

+/-

4 18

+/-

4 18

+/-

4 13

+/-

4 18

+/-

4 18

+/-

4 19

+/-

4 16

+/-

4 06/26/2024 14

+/-

4 17

+/-

4 16

+/-

4 12

+/-

4 18

+/-

4 17

+/-

4 17

+/-

4 14

+/-

4 11

+/-

4 14

+/-

4 07/03/2024 17

+/-

4 16

+/-

4 17

+/-

4 17

+/-

4 15

+/-

4 15

+/-

4 12

+/-

4 18

+/-

4 18

+/-

4 16

+/-

4 07/10/2024 16

+/-

5 16

+/-

4 17

+/-

5 17

+/-

5 12

+/-

4 17

+/-

5 17

+/-

5 14

+/-

4 18

+/-

5 17

+/-

5 07/1 7/2024 18

+/-

4 22

+/-

5 15

+/-

4 16

+/-

4 17

+/-

4 17

+/-

4 21

+/-

4 17

+/-

4 20

+/-

4 21

+/-

4 07/24/2024 14

+/-

4 20

+/-

4 18

+/-

4 18

+/-

4 17

+/-

4 15

+/-

4 17

+/-

4 15

+/-

4 16

+/-

4 21

+/-

5 07/31/2024 19

+/-

4 24

+/-

5 22

+/-

4 21

+/-

4 23

+/-

5 25

+/-

5 21

+/-

4 23

+/-

5 24

+/-

5 20

+/-

4 08/07/2024 23

+/-

5 22

+/-

4 15

+/-

4 19

+/-

4 19

+/-

4 20

+/-

4 18

+/-

4 18

+/-

4 19

+/-

4 19

+/-

4 08/14/2024 22

+/-

5 22

+/-

5 19

+/-

4 21

+/-

4 20

+/-

4 17

+/-

4 21

+/-

4 19

+/-

4 19

+/-

4 20

+/-

4 08/21/2024 27

+/-

5 30

+/-

5 32

+/-

5 26

+/-

5 29

+/-

5 24

+/-

5 27

+/-

5 24

+/-

5 32

+/-

5 26

+/-

5 08/28/2024 22

+/-

4 18

+/-

4 18

+/-

4 23

+/-

5 19

+/-

4 22

+/-

4 26

+/-

5 16

+/-

4 22

+/-

5 23

+/-

5 09/04/2024 20

+/-

5 20

+/-

5 17

+/-

4 19

+/-

4 19

+/-

5 21

+/-

5 23

+/-

5 19

+/-

4 23

+/-

5 22

+/-

5 09/11/2024 32

+/-

5 29

+/-

5 31

+/-

5 22

+/-

5 25

+/-

5 26

+/-

5 29

+/-

5 22

+/-

5 27

+/-

5 25

+/-

5 09/18/2024 21

+/-

5 30

+/-

5 21

+/-

5 24

+/-

5 21

+/-

5 23

+/-

5 23

+/-

5 20

+/-

5 25

+/-

5 22

+/-

5 09/25/2024 18

+/-

4 21

+/-

5 18

+/-

4 17

+/-

4 15

+/-

4 18

+/-

4 21

+/-

5 11

+/-

4 18

+/-

4 15

+/-

4 10/02/2024 29

+/-

5 31

+/-

5 30

+/-

5 26

+/-

5 31

+/-

5 28

+/-

5 31

+/-

5 34

+/-

5 31

+/-

5 29

+/-

5 10/09/2024 31

+/-

5 29

+/-

5 31

+/-

5 31

+/-

5 30

+/-

5 31

+/-

5 32

+/-

5 23

+/-

4 30

+/-

5 30

+/-

5 10/1 6/2024 26

+/-

5 28

+/-

5 27

+/-

5 30

+/-

5 27

+/-

5 31

+/-

5 29

+/-

5 22

+/-

5 33

+/-

5 32

+/-

5 10/23/2024 36

+/-

5 28

+/-

5 34

+/-

5 31

+/-

5 31

+/-

5 33

+/-

5 26

+/-

5 25

+/-

5 31

+/-

5 35

+/-

5

Annual Radiological Environmental Operating Report YEAR: 2024 Page 39 of 79 Table 11, Weekly Air Particulate Gross Beta (E-3 pCi/m3) Cont'd Collection CL-2 CL-3 CL-4 CL-6 CL-15 CL-94 CL-1 CL-7 CL-8 CL-11 Date 10/30/2024 18

+/-

4 15

+/-

4 19

+/-

4 16

+/-

4 16

+/-

4 18

+/-

4 15

+/-

4 15

+/-

4 16

+/-

4 16

+/-

4 11/06/2024 16

+/-

4 15

+/-

4 14

+/-

4 16

+/-

4 18

+/-

5 16

+/-

4 15

+/-

4 12

+/-

4 13

+/-

4 15

+/-

4 11 /13/2024 26

+/-

5 23

+/-

5 25

+/-

5 30

+/-

5 24

+/-

5 29

+/-

5 26

+/-

5 22

+/-

4 25

+/-

5 31

+/-

5 11/20/2024 20

+/-

4 14

+/-

4 23

+/-

4 15

+/-

4 19

+/-

4 18

+/-

4 20

+/-

4 19

+/-

4 18

+/-

4 19

+/-

4 11/27/2024 27

+/-

5 36

+/-

5 36

+/-

5 35

+/-

5 30

+/-

5 32

+/-

5 33

+/-

5 34

+/-

5 31

+/-

5 34

+/-

5 12/04/2024 21

+/-

5 23

+/-

5 22

+/-

5 16

+/-

4 19

+/-

5 22

+/-

5 21

+/-

5 22

+/-

5 23

+/-

5 17

+/-

4 12/11/2024 28

+/-

5 27

+/-

5 26

+/-

5 28

+/-

5 26

+/-

5 25

+/-

5 28

+/-

5 25

+/-

5 26

+/-

5 29

+/-

5 12/18/2024 23

+/-

5 26

+/-

6 25

+/-

5 24

+/-

5 25

+/-

5 23

+/-

5 20

+/-

5 24

+/-

5 22

+/-

5 22

+/-

5 12/24/2024 29

+/-

5 31

+/-

5 27

+/-

5 30

+/-

5 27

+/-

5 31

+/-

5 28

+/-

5 31

+/-

5 32

+/-

5 30

+/-

5

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 40 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center Table 12, Quarterly Air Particulate Gamma Isotopic (pCi/m3 +/- 2 Sigma)

Station Nuclide Q1 Q2 Q3 Q4 Station Nuclide Q1 Q2 Q3 Q4 Co-60 4

5 3

2 Co-60 3

3 3

2 Nb-95 3

4 2

2 Nb-95 2

3 3

3 Zr-95 6

8 4

4 Zr-95 3

5 3

4 Ru-103 3

4 3

2 Ru-103 2

3 3

3 CL-2 Ru-106

< 28

< 33 21

< 19 CL-4 Ru-106 15 20 15 17 Cs-134 4

5 3

3 Cs-134 2

3 2

3 Cs-137 2

4 2

2 Cs-137 2

2 2

2 Ce-141 3

6 4

3 Ce-141 2

4 3

3 Ce-144 11 18 10 9

Ce-144 8

11 10 9

Co-60 3

2 4

2 Co-60 3

2 2

2 Nb-95 3

2 4

2 Nb-95 2

2 2

3 Zr-95 5

3 6

3 Zr-95 3

4 4

6 Ru-103 2

2 4

2 Ru-103 2

2 2

3 CL-3 Ru-106 17 14 29 16 CL-6 Ru-106 17 14 13 17 Cs-134 3

2 3

2 Cs-134 2

2 2

3 Cs-137 2

2 3

2 Cs-137 2

2 2

2 Ce-141 2

2 4

2 Ce-141 2

3 3

3 Ce-144 9

6 12 6

Ce-144 8

8 6

10

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 41 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 Co-60 2

< 4 2

3 Co-60 3

2 2

1 Nb-95 2

< 4 3

2 Nb-95 2

3 2

2 Zr-95 3

< 7 4

4 Zr-95 4

4 4

4 Ru-103 2

< 5 2

2 Ru-103 2

2 2

2 CL-15 Ru-106 16

< 27 19 17 CL-1 Ru-106 18 18 17 19 Cs-134 2

< 3 2

2 Cs-134 2

3 2

2 Cs-137 2

< 4 2

2 Cs-137 2

2 2

2 Ce-141 2

< 5 3

3 Ce-141 3

2 3

3 Ce-144 8

12 9

8 Ce-144 9

6 8

9 Co-60 2

< 2 3

2 Co-60 3

3 5

2 Nb-95 2

< 3 3

2 Nb-95 3

3 5

3 Zr-95 3

5 6

5 Zr-95 5

5 8

5 Ru-103 2

< 2 3

2 Ru-103 2

2 5

3 CL-94 Ru-106 23 18 21 23 CL-7 Ru-106 22 19 31 21 Cs-134 2

< 2 4

3 Cs-134 3

3 3

3 Cs-137 2

< 2 3

2 Cs-137 3

2 4

3 Ce-141 3

< 3 5

3 Ce-141 3

3 6

5 Ce-144 8

< 7 12 9

Ce-144 11 7

16 13

Annual Radiological Environmental Operating Report YEAR: 2024 Page 42 of 79 Table 12, Quarterly Air Particulate Gamma Isotopic (pCi/m3 +/- 2 Sigma) Cont'd Station Nuclide Q1 Q2 Q3 Q4 Co-60 3

2 3

2 Nb-95 2

2 2

< 2 Zr-95 5

4 4

4 Ru-103 2

2 3

2 CL-8 Ru-106 17 17 19 17 Cs-134 2

2 2

2 Cs-137 2

2 2

2 Ce-141 2

3 3

3 Ce-144 9

7 10 7

Co-60 3

3

< 4 3

Nb-95 3

3

< 4 2

Zr-95

< 4 5

6

< 4 Ru-103 2

3 3

3 CL-11 Ru-106 24 19 27 21 Cs-134 2

2 3

3 Cs-137 2

2 3

2 Ce-141 3

3

< 4 3

Ce-144 13 9

9 8

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 43 of 79 Company: Constellation I Plant: Clinton Clean EnerQV Center Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3)

Collection CL-2 CL-3 CL-4 CL-6 CL-15 CL-94 CL-1 CL-7 CL-8 CL-11 Date 01/03/2024

< 48

< 33

< 49

< 39

< 49

< 39

< 39 18 01/10/2024

< 23

< 54

< 57

< 55

< 57

< 56

< 24 01/17/2024

< 37

< 49

< 49 17

< 50

< 50 21 01/24/2024

< 35

< 36

< 20

< 15

< 19 19 19 01/31/2024

< 37

< 38

< 29

< 43

< 19

< 43

< 43 02/07/2024

< 24 11

< 23

< 25

< 24

< 23

< 24

< 24 16 02/14/2024

< 30

< 13

< 30

< 43

< 38

< 30

< 38

< 37 02/21/2024

< 36

< 36 15

< 46

< 36

< 45

< 45 19 02/28/2024 18

< 43

< 54

< 53

< 43

< 53

< 23

< 52 03/06/2024

< 38

< 37

< 18

< 38 19

< 37

< 38

< 37

< 37 37 03/13/2024 17

< 42

< 41

< 42

< 29

< 42

< 29

< 22

< 29 03/20/2024

< 23

< 11

< 16

< 25

< 23

< 24

< 24 03/27/2024 18

< 42

< 41

< 42 55

< 23

< 42

< 54

< 54 04/03/2024

< 35 35 15 35 36

< 35

< 36

< 15

< 35 04/10/2024

< 58 58 58 58 58

< 58

< 25

< 24

< 58

< 58 04/17/2024

< 41

< 41 41 41 37

< 38

< 22

< 37

< 38

< 29 04/24/2024

< 39

< 40 17 40

< 18

< 43

< 40

< 43

< 45 05/01/2024

< 40 41 41 41 24

< 34 18 34

< 34

< 34 05/08/2024

< 15 37 37 37 39

< 40

< 36

< 39

< 39 17 05/15/2024

< 58 59 27 58 19

< 39

< 59

< 39

< 40

< 40 05/22/2024

< 40 17

< 40

< 40 46

< 43

< 39 19

< 44

< 45

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 44 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3) Cont'd Collection CL-2 CL-3 CL-4 CL-6 CL-15 CL-94 CL-1 CL-7 CL-8 CL-11 Date 05/29/2024

< 48 21

< 49

< 59 26 50 58

< 58 58 06/05/2024

< 44 19

< 44 44

< 49 47 44

< 49 21 48 06/12/2024

< 33

< 23

< 34

< 34 16 34

< 33 33 33 06/19/2024

< 37

< 38

< 37

< 37 22 51 16 51 51 51 06/26/2024 15

< 33

< 26 17 33 26 26 26 07/03/2024

< 28 41

< 41 41

< 39 18 41

< 39 39 38 07/10/2024

< 26

< 39

< 39 39

< 29 13 39

< 29 29 29 07/17/2024

< 40 21

< 41 41

< 52

< 37 41 51 52 51 07/24/2024

< 44

< 45

< 37 38 33 16 37 38 07/31/2024

< 43

< 29

< 43

< 42 59 43

< 57 58 57 08/07/2024

< 35

< 40 39 26 40

< 40 30 08/14/2024

< 21

< 43

< 37 37 43 36 37 19 08/21/2024

< 39

< 45 19 30

< 45

< 45 45 08/28/2024

< 43

< 42

< 43

< 37 40 33

< 36 37 37 09/04/2024

< 34

< 47

< 37 36

< 47

< 36 36 39 09/11/2024

< 40

< 40 31

< 40

< 44 22 40

< 45

< 45 44 09/18/2024

< 41 41

< 32

< 42

< 37 19 41 38 38 37 09/25/2024

< 38

< 20

< 39 38

< 35 34 38 25 33 34 10/02/2024

< 38 51 51 51

< 47 33 51

< 47 48 48 10/09/2024 51 51

< 50 51 51 24 38 50 50 50 10/16/2024 21 41

< 41 41 31 32 41

< 32 32 24 10/23/2024

< 26 38

< 38

< 38 19 41 38 41 41 41

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 45 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 13, Weekly Air Iodine 1-131 (E-3 pCi/m3) Cont'd Collection CL-2 CL-3 CL-4 CL-6 CL-15 CL-94 CL-1 CL-7 CL-8 CL-11 Date 10/30/2024

< 27

< 41

< 41 41

< 30

< 40

< 42

< 39

< 39 11/06/2024

< 47

< 20

< 48

< 47

< 54

< 53

< 48

< 53

< 39 11/13/2024

< 45 31

< 45 46

< 43

< 45

< 20

< 43

< 43 11/20/2024

< 39

< 44 21

< 30

< 44

< 44 11/27/2024 17

< 40

< 48

< 41

< 48

< 35 12/04/2024

< 17

< 36

< 28

< 26

< 37

< 27

< 29 12/11/2024

< 46

< 46 51

< 46

< 50 21

< 46

< 50

< 50 12/18/2024

< 42

< 22

< 42

< 41

< 40

< 42 41

< 41

< 45 12/24/2024

< 25 25

< 25

< 28

< 41

< 16 41

< 41

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 46 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 14, Monthly/Bi-Weekly Milk 1-131 (pCi/L +/- 2 Sigma)

Collection Date CL-116 01/31/2024 0.6 02/28/2024 0.9 03/27/2024 0.9 04/24/2024 0.9 05/15/2024 0.8 05/29/2024 0.8 06/12/2024 0.9 06/26/2024 0.7 07/10/2024 0.9 07/24/2024 0.8 08/07/2024 0.7 08/21/2024 0.8 09/04/2024 0.8 09/18/2024 0.8 10/02/2024 0.7 10/16/2024 0.9 10/30/2024 0.8 11/27/2024 0.9 12/31/2024 0.9

Annual Radiological Environmental Operating Report YEAR: 2024 Page 47 of 79 Table 15, Monthly/Bi-Weekly Milk Gamma Isotopic (pCi/L +/- 2 Sigma)

Station Collection K-40 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 Ce-144 Dates 01 /31 /2024 1058

+/-

187 9

8 18 8

16 9

14 9

8 32 12 49 02/28/2024 1252

+/-

171 5

5 11 7

11 7

10 7

6 19 7

47 03/27/2024 1116

+/-

160 7

9 15 9

16 7

13 6

8 31 10 59 04/24/2024 883

+/-

143 5

8 15 10 16 7

11 6

8 28 8

39 05/15/2024 1059

+/-

155 6

7 14 8

16 7

11 8

6 28 8

47 05/29/2024 1066

+/-

160 7

7 19 7

17 8

12 8

8 35 7

53 06/12/2024 1204

+/-

198 8

9 17 10 19 6

13 8

7 38 8

50 06/26/2024 1172

+/-

153 6

8 16 7

14 6

11 6

7 29 9

45 07/10/2024 1008

+/-

164 7

6 16 7

17 8

12 9

7 32 9

52 CL-116 07/24/2024 1094

+/-

148 8

7 17 8

15 7

13 9

7 31 8

50 08/07/2024 991

+/-

155 6

6 14 7

18 7

12 8

8 30 9

54 08/21/2024 1081

+/-

144 8

8 19 6

15 8

13 8

8 36 11 44 09/04/2024 1077

+/-

195 8

9 18 9

20

< 7 16 9

8 32 13 45 09/18/2024 1049

+/-

161 8

8 18 10 17 7

11 9

7 34 9

45 10/02/2024 1198

+/-

91 4

4 10 5

11 4

7 5

4 19 6

28 10/16/2024 1202

+/-

148 7

7 14 8

17 7

11 7

6 29 8

44 10/30/2024 994

+/-

146 7

8 16 9

15 6

11 8

7 32 12 44 11/27/2024 910

+/-

139 6

6 13 7

18 8

12 8

7 28 8

50 12/31/2024 986

+/-

159 6

7 16 7

18 8

13 8

8 27 10 42

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 48 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 Ce-144 Dates KALE 06/26/2024

< 41

< 32

< 76

< 43

< 76

< 38

< 63

< 38

< 36

< 48

< 142

< 43

< 220 LETTUCE 06/26/2024

< 36

< 29

< 71

< 40

< 77

< 37

< 63

< 47

< 32

< 37

< 127

< 41 177 SWISS CHARD 06/26/2024

< 37

< 24

< 79

< 47

< 86

< 29

< 63

< 35

< 49

< 40

< 165

< 46 176 KALE 07/24/2024

< 32 31

< 88

< 34

< 48

< 30

< 54

< 37

< 34

< 38

< 117

< 36 161 LETTUCE 07/24/2024

< 18

< 17 41

< 16 41 17

< 30

< 28

< 18

< 20

< 77

< 24 120 SWISS 07/24/2024 31 28 67 47 71 35 58 53 36 40 152 55 223 CHARD CL-114 BROCCOLI 08/28/2024

< 33

< 23

< 71

< 41

< 64

< 38

< 46 44

< 37

< 29

< 143

< 43

< 212 KALE 08/28/2024

< 22

< 25

< 54

< 22

< 48

< 28

< 44

< 35

< 25

< 19

< 105

< 27

< 119 SWISS 08/28/2024 CHARD 40

< 32

< 75

< 38

< 89

< 36

< 64

< 48

< 40

< 32

< 139

< 44

< 193 BROCCOLI 09/25/2024 31

< 20

< 62

< 31

< 59

< 27

< 43

< 47

< 33

< 30

< 133

< 44 179 KALE 09/25/2024

< 23

< 20 47

< 27 61

< 14 31

< 30 21

< 19

< 94

< 20 124 SWISS 09/25/2024

< 19

< 23 45

< 25

< 54

< 22 CHARD

< 38

< 36

< 24

< 20

< 88

< 29

< 97

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 49 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 Ce-144 Dates KALE 06/26/2024

< 41

< 36

< 86

< 33

< 98

< 48

< 70

< 53

< 45

< 38

< 173

< 20

< 215 LETTUCE 06/26/2024

< 42

< 33

< 74

< 42 91

< 42

< 52

< 46

< 35

< 125

< 37

< 214 SWISS CHARD 06/26/2024

< 30

< 28

< 69

< 30

< 59

< 32

< 39

< 48

< 28

< 29

< 117

< 28

< 183 KALE 07/24/2024

< 28

< 27

< 58

< 22

< 66

< 31

< 45

< 36

< 33

< 27

< 122

< 35

< 139 LETTUCE 07/24/2024

< 29

< 40

< 81

< 37

< 91

< 35

< 60

< 47

< 41

< 33

< 133

< 48

< 187 SWISS CHARD 07/24/2024

< 42

< 32

< 80

< 30

< 90 31

< 73

< 50

< 35

< 28

< 94

< 52

< 198 CL-115 KALE 08/28/2024 29

< 31

< 70

< 35

< 61

< 33

< 47

< 45

< 40

< 35

< 118

< 53

< 171 LETTUCE/KALE 08/28/2024

< 35

< 31

< 77

< 38

< 81

< 30

< 56

< 48

< 34

< 35 151

< 50

< 183 SWISS CHARD 08/28/2024 31

< 36

< 71

< 32

< 80

< 30

< 57

< 49

< 34

< 23

< 132

< 41

< 189 KALE 09/25/2024

< 21

< 18

< 49

< 23

< 52 19

< 35

< 32

< 24

< 19

< 86

< 20

< 104 KALE/SWISS 09/25/2024

< 18

< 18 CHARD

< 41

< 21

< 45 17

< 30

< 34

< 21

< 19

< 94 31

< 116 SWISS CHARD 09/25/2024

< 15

< 16

< 36

< 17

< 37 16

< 32

< 28

< 15 18

< 78

< 20

< 111

Annual Radiological Environmental Operating Report YEAR: 2024 Page 50 of79 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 Ce-144 Dates KALE 06/26/2024

< 38

< 34

< 87

< 45

< 90

< 37

< 65

< 52

< 38

< 41

< 166

< 57

< 184 LETTUCE 06/26/2024

< 39

< 98

< 40

< 74

< 40

< 55

< 46

< 41

< 38

< 117

< 46

< 224 SWISS CHARD 06/26/2024

< 33

< 40

< 94

< 42

< 58

< 37

< 70

< 50

< 40

< 43

< 172

< 41

< 196 KALE 07/24/2024

< 28

< 20

< 56

< 35

< 87

< 31

< 42

< 36

< 34

< 25

< 110

< 40

< 152 LETTUCE 07/24/2024

< 33

< 43

< 56

< 43 77

< 42

< 49

< 46

< 40

< 39

< 142

< 49

< 209 CL-118 SWISS CHARD 07/24/2024

< 25

< 24

< 43

< 36

< 71

< 26

< 44

< 36 31

< 30

< 113

< 38

< 161 KALE/LETTUCE 08/28/2024

< 27

< 33 77

< 40

< 90

< 37

< 55

< 47

< 35 31

< 145

< 42

< 184 LETTUCE 08/28/2024

< 39

< 29

< 84

< 37

< 101

< 39

< 80

< 45

< 47

< 43

< 146

< 48

< 207 SWISS CHARD 08/28/2024

< 32

< 34

< 90

< 37

< 79

< 38

< 56

< 53

< 37

< 39

< 170

< 42

< 204 KALE/LETTUCE/SWISS 09/25/2024

< 22

< 25

< 65

< 33

< 56

< 25 51

< 37

< 28

< 24

< 107

< 33

< 111 CHARD

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 51 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center Table 17, Bi-weekly Grass Gamma Isotopic (pCi/kg Wet+/- 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 Ce-144 05/15/2024

< 32

< 29

< 67

< 30 113 26

< 53 44 49 33 125 42 166 05/29/2024

< 24

< 26

< 57

< 33 59 26 39

< 35 27 27 115 33 122 06/12/2024

< 29

< 28

< 56

< 27 64 29

< 52

< 47 31 31 135 39 187 06/26/2024

< 32

< 29

< 66

< 33 68

< 33

< 46

< 43 36 29 123 28 160 07/10/2024

< 22 21

< 53

< 29 54 25

< 47

< 37 26 24 109 33 141 07/24/2024

< 38

< 27

< 65

< 41 66 35

< 54

< 40 28 33 149 34 203 CL-01 08/07/2024

< 23

< 25 51

< 30 58 26

< 44

< 43 28 26 123 28 173 08/21/2024

< 25

< 27

< 70

< 29 67

< 29

< 59

< 39 28 32 133 39 212 09/04/2024

< 23 18

< 52

< 22 55

< 25

< 45

< 36 26 22 111 26 116 09/18/2024

< 32

< 33

< 78

< 38 92 41 72

< 50 44 40 151 41 202 10/02/2024

< 23

< 55 29 59

< 24

< 46

< 38 25 22 99 25 150 10/16/2024

< 20

< 19

< 43 21 43 19

< 33

< 29 23 20 84 19 109

Annual Radiological Environmental Operating Report YEAR: 2024 Page 52 of 79 Table 17, Bi-weekly Grass Gamma Isotopic (pCi/kg Wet+/- 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 Ce-144 05/15/2024

< 29

< 31

< 75

< 37

< 65

< 29

< 49

< 37

< 32

< 28

< 162

< 27

< 140 05/29/2024

< 24

< 23

< 46

< 23

< 53

< 23

< 37

< 34

< 23

< 96

< 28 145 06/12/2024

< 32

< 33

< 83

< 44

< 76

< 39

< 54

< 52

< 32

< 35 161

< 43

< 202 06/26/2024

< 28

< 76

< 38

< 70 31

< 59

< 45

< 34

< 30

< 142

< 33

< 256 07/10/2024

< 28

< 35

< 78

< 38

< 68

< 22

< 54

< 40

< 29

< 23

< 130

< 43

< 156 07/24/2024

< 20

< 19

< 43

< 18

< 50

< 20

< 38

< 26

< 20

< 19 72

< 26

< 105 CL-02 08/07/2024

< 31

< 36

< 70

< 28

< 63

< 27

< 47

< 42

< 30

< 29

< 112

< 38

< 167 08/21/2024

< 30

< 28

< 62

< 36

< 78

< 32

< 47

< 50

< 35

< 28

< 127

< 38

< 176 09/04/2024

< 30

< 24

< 58

< 33

< 66

< 27 41

< 39

< 25

< 26

< 97

< 22

< 154 09/18/2024

< 18

< 16

< 38

< 19

< 41 17

< 28

< 25

< 17

< 17 71 21

< 88 10/02/2024

< 20

< 48

< 23

< 54

< 23

< 37

< 35

< 22

< 100

< 26

< 136 10/16/2024

< 20

< 22

< 40

< 21

< 47

< 22

< 38

< 33

< 22

< 98

< 29

< 122

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 53 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 17, Bi-weekly Grass Gamma Isotopic (pCi/kg Wet+/- 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 Ce-144 05/15/2024

< 27

< 34

< 57

< 32

< 69

< 28

< 42

< 26

< 32 128

< 33

< 140 05/29/2024

< 20

< 18

< 38

< 15

< 43

< 19

< 29

< 26 18

< 18 77

< 15

< 113 06/12/2024

< 38

< 35

< 107

< 33

< 90

< 38

< 62

< 46

< 28

< 39

< 160

< 36

< 202 06/26/2024

< 20

< 23

< 47

< 23

< 53 16 31 31

< 25

< 22

< 87

< 22

< 142 07/10/2024

< 29

< 35

< 63

< 29

< 68 31

< 54

< 54 31

< 33

< 130

< 43

< 197 07/24/2024

< 22

< 58

< 28

< 57

< 23

< 44

< 27

< 22

< 23

< 95 31

< 116 CL-08 08/07/2024 21

< 23

< 52

< 22

< 55

< 24 41

< 32

< 25

< 26

< 87

< 30 122 08/21/2024

< 29

< 26

< 53

< 43

< 65

< 30

< 47

< 46

< 32

< 29 141

< 34

< 152 09/04/2024

< 26

< 25

< 61

< 31

< 60

< 27

< 43

< 39

< 27

< 24

< 105

< 26

< 132 09/18/2024

< 31

< 36

< 82

< 39

< 94

< 32

< 62

< 50

< 35

< 33

< 142 41

< 182 10/02/2024

< 32

< 33

< 83

< 34

< 85

< 35

< 55

< 45

< 35 171

< 45

< 163 10/16/2024

< 25

< 26

< 57

< 28

< 69

< 28

< 46

< 42

< 27

< 28

< 119

< 34

< 162

Annual Radiological Environmental Operating Report YEAR: 2024 Page 54 of 79 Table 17, Bi-weekly Grass 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 Ce-144 Dates 05/15/2024

< 27

< 28

< 68

< 28

< 69

< 28

< 56

< 44

< 32

< 26

< 105

< 45

< 140 05/29/2024

< 27

< 25

< 63

< 25

< 48

< 24

< 32

< 25

< 114 31

< 156 06/12/2024

< 28

< 30

< 82

< 41 72

< 38

< 55

< 49

< 35

< 40

< 159

< 36

< 178 06/26/2024

< 23

< 33

< 65

< 44

< 76

< 38

< 48

< 42

< 36

< 28

< 115

< 31

< 203 07/10/2024

< 18

< 24

< 47

< 28

< 47

< 22

< 40

< 36

< 23

< 20

< 94

< 25 151 07/24/2024

< 27

< 28

< 62

< 36 77

< 25

< 46

< 31

< 139

< 23

< 212 CL-11 6 08/07/2024

< 29

< 35

< 87

< 30

< 81

< 40 61

< 49

< 38

< 37

< 119

< 26

< 178 08/21/2024

< 25

< 28

< 58 31

< 61

< 32

< 41

< 43

< 30

< 28

< 116

< 35

< 193 09/04/2024

< 20 21

< 59

< 24

< 59

< 24

< 40

< 36

< 27

< 26

< 105

< 26

< 149 09/18/2024

< 37

< 33 77

< 41

< 76

< 33

< 58

< 50

< 35

< 32

< 128

< 50

< 165 10/02/2024

< 6

< 15

< 7 16

< 7

< 12

< 10

< 7

< 6

< 27

< 9

< 28 10/16/2024

< 20

< 41

< 22

< 47 19

< 34

< 32

< 20 21

< 85

< 25

< 108

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 55 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center Table 18, Monthly Surface Water lodine-131 (pCi/L +/- 2 Sigma)

Collection 1-131 Station Dates 12/27/2023 0.6 01/31/2024 0.8 02/28/2024 0.8 03/27/2024 0.9 04/24/2024 0.8 05/29/2024 0.8 CL-90 06/26/2024 0.7 07/31/2024 0.8 08/28/2024 0.7 09/25/2024 0.9 10/30/2024 0.7 11/27/2024 0.8

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 56 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center 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 Cs-134 Cs-137 Ba-140 La-140 Ce-144 12/27/2023 01/31/2024 9

6 7

7 13 7

12 8

7 29 9

42 01 /31 /2024 02/28/2024 6

6 12 5

16 8

12 7

7 23 11 40 02/28/2024 03/27/2024 7

8 16 9

15 8

13 9

9 37 13 43 03/27/2024 04/24/2024 5

6 12 6

13 5

10 5

6 25 7

42 04/24/2024 05/29/2024 5

6 12 5

12 6

9 8

8 18 11 40 05/29/2024 06/26/2024 7

6 13 8

13 7

10 6

7 26 10 44 CL-90 06/26/2024 -

07/31/2024 6

5 10 6

11 5

9 5

5 26 6

37 07/31 /2024 08/28/2024 7

7 17 8

6 6

14 7

9 35 14 50 08/28/2024 09/25/2024 5

6 12 5

12 6

9 8

6 29 11 41 09/25/2024 10/30/2024 8

6 16 8

13 8

14 9

8 30 12 52 10/30/2024 11/27/2024 5

6 11 7

10 5

10 6

5 26 9

42 11/27/2024 12/31/2024 7

6 11 9

15 7

12 7

6 39 8

41

Annual Radiological Environmental Operating Report YEAR: 2024 Page 57 of 79 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 Cs-134 Cs-137 Ba-140 La-140 Ce-144 01 /31/2024 01/31/2024 8

7

< 16 9

17 7

14 7

8 34 8

44 02/28/2024 02/28/2024 6

6

< 13 6

13 4

8 7

6 21 9

39 03/27/2024 03/27/2024 8

10

< 15 9

13 10 15 8

10 35 13 48 04/24/2024 04/24/2024 5

6

< 8 6

12 5

9 6

7 24 8

37 05/29/2024 05/29/2024 5

7

< 16 10 12 8

10 7

7 23 13 43 06/26/2024 06/26/2024 7

8

< 16 8

16 7

13 7

8 34 9

55 CL-13 07/31/2024 07/31 /2024 4

5

< 8 4

9 4

8 5

4 19 8

28 08/28/2024 08/28/2024 6

5

< 13

< 7 17 7

11 6

7 30 8

55 09/25/2024 09/25/2024 6

5

< 8 5

9 7

9 6

5 25 7

44 10/30/2024 10/30/2024

< 7 7

< 13 6

12 7

8 32 12 41 11/27/2024 11 /27/2024

< 7 7

< 13 7

13 7

11 7

7 33 9

54 12/31/2024 12/31/2024 6

5

< 13 7

11 6

10 6

6 33 14 42

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 58 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 Cs-134 Cs-137 Ba-140 La-140 Ce-144 12/27/2023 01/31/2024 7

8 16 7

14 6

15 8

8 32 10 61 01/31/2024 02/28/2024 6

6 11 6

13 7

10 7

5 20 7

44 02/28/2024 -

03/27/2024 5

7 12 15 10 5

9 6

4 29 13 40 03/27/2024 04/24/2024 7

6 11 7

12 6

5 26 10 39 04/24/2024 05/29/2024 6

5 15 6

13 7

6 27 11 42 05/29/2024 06/26/2024 7

7

< 8 4

13 6

13 7

7 32 11 45 CL-91 06/26/2024 07/31/2024 6

6 11 7

10 7

11 7

6 25 9

42 07/31/2024 08/28/2024 7

8 16 11 14 9

13 9

8 37 10 59 08/28/2024 09/25/2024 8

8 17 8

17 8

11 6

7 33 11 43 09/25/2024 10/30/2024 6

6 15 8

20 9

13 8

8 29 11 48 10/30/2024 11/27/2024 8

8 15 9

19 7

14 8

9 43 10 66 11/27/2024 12/31/2024 5

7 13 10 16 8

13 8

8 38 9

41

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 59 of 79 Company: Constellation I Plant: Clinton Clean Energy Center 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 Cs-134 Cs-137 Ba-140 La-140 Ce-144 12/27/2023 01/31 /2024 6

6 12 5

15 6

12 7

5 20 5

43 01 /31/2024 02/28/2024

< 6 5

12 6

11 6

8 6

6 27 7

48 02/28/2024 03/27/2024

< 7

< 7 16 5

15 6

14 7

7 41 15 47 03/27/2024 04/24/2024

< 5

< 4 9

6 10 4

6 4

4 22 6

32 04/24/2024 05/29/2024

< 6 4

16 7

14 7

12 7

7 24 14 43 05/29/2024 06/26/2024

< 5

< 7 12 8

10 6

9 6

6 26 10 42 CL-99 06/26/2024 07/31/2024

< 5 6

18 6

11 6

11 8

7 26 12 42 07/31/2024 08/28/2024

< 7 8

15 9

15 7

13 9

6 27 11 40 08/28/2024 09/25/2024

< 5 6

11 6

13 6

9 7

5 25 9

36 09/25/2024 10/30/2024

< 6 4

11 7

12 5

10 6

5 21 6

37 10/30/2024 11/27/2024

< 6 5

10 6

11 6

8 6

5 22 8

34 11/27/2024 12/31/2024

< 7

< 7 12 7

17 7

12 7

8 31 11 46

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 60 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 20, Quarterly Surface Water Tritium (pCi/L +/- 2 Sigma)

Station Collection Dates H-3 12/27/2023 03/27/2024 183 03/27/2024 06/26/2024 196 CL-90 06/26/2024 09/23/2024 185 09/23/2024 12/31/2024 183 12/27/2023 03/27/2024 185 03/27/2024 06/26/2024 195 CL-13 06/26/2024 09/23/2024 181 09/23/2024 12/31/2024 178 12/27/2023 03/27/2024 181 03/27/2024 06/26/2024 193 CL-91 06/26/2024 09/23/2024 183 09/23/2024 12/31/2024 175 12/27/2023 03/27/2024 185 03/27/2024 06/26/2024 200 CL-99 06/26/2024 09/23/2024 181 09/23/2024 12/31/2024 176

Annual Radiological Environmental Operating Report YEAR: 2024 Page 61 of 79

.-----------==--------~---=--------==------=------'------'----_;;:_

Com an : Constellation Plant: Clinton Clean Ener Center Table 21, Monthly Drinking Water Gross Beta and 1-131 (pCi/L +/- 2 Sigma)

Collection Dates Gr-B 1-131 Station 01/31/2024 1.6 0.8 02/28/2024 1.6 0.8 03/27/2024 1.7 0.8 04/24/2024 1.6 0.8 05/29/2024 1.7 0.9 06/26/2024 1.7 0.9 CL-14 07/03/2024 1.6 0.7 08/07/2024 1.4 0.9 09/04/2024 1.6 0.7 10/02/2024 2.3 0.9 11/06/2024 1.3 0.9 12/04/2024 1.6 0.9

Annual Radiological Environmental Operating Report YEAR: 2024 Page 62 of 79 Table 22, Monthly Drinking 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 Ce-144 01/31/2024 -

01/31/2024 5

7 17 8

< 13

< 7

< 11 9

10 24 15 48 02/28/2024 -

02/28/2024 5

6 11 6

< 12

< 6

< 10 7

6 23 8

38 03/27/2024 03/27/2024 6

< 4 14 8

< 17

< 5

< 11 5

6 28 10 40 04/24/2024 -

04/24/2024

< 5 5

16 5

< 10

< 6

< 10 6

6 27 6

36 05/29/2024 05/29/2024

< 6

< 12 9

< 12

< 6

< 10 7

< 6 29 10 39 06/26/2024 06/26/2024

< 5

< 7 12 5

< 10

< 6

< 9 7

4 27 10 41 CL-14 07/03/2024 -

07/31 /2024

< 6

< 7 12 6

< 14

< 6

< 11 6

7 31 8

43 08/07/2024 08/28/2024

< 6 5

10 5

< 11

< 6

< 10 6

7 26 7

44 09/04/2024 09/25/2024

< 7

< 7 13 9

< 17

< 7

< 12 8

7 36 12 48 10/02/2024 -

10/30/2024 6

< 7 14 7

< 13

< 6

< 11 7

8 34 11 46 11/06/2024 -

11/27/2024 6

6 13 7

< 12

< 6

< 12 6

7 27 8

45 12/04/2024 12/31 /2024

< 6 6

10 6

< 15

< 6

< 9 9

8 29 10 37

Annual Radiological Environmental Operating Report YEAR: 2024 Page 63 of 79 Com an : Constellation Plant: Clinton Clean Ener Center Table 23, Quarterly Drinking Water Tritium (pCi/L +/- 2 Sigma)

Station Collection Dates H-3 01/31/2024 03/27/2024

186 04/24/2024 06/26/2024 197 CL-14 07/03/2024 09/25/2024 197 10/30/2024 12/31/2024 179

Annual Radiological Environmental Operating Report

\\ YEAR: 2024 \\

Page 64 of 79 Company: Constellation

\\ Plant: Clinton Clean Energy Center Table 24, Quarterly Groundwater Tritium (pCi/L +/- 2 Sigma)

Collection CL-07D CL-12R CL-12T Date 03/27/2024 191 189 189 06/26/2024 174 174 193 09/25/2024 175 177 178 12/31/2024 (1) 183 185 (1) See Sample Deviation Table

Annual Radiological Environmental Operating Report YEAR: 2024 Page 65 of 79 Table 25, 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 Cs-134 Cs-137 Ba-140 La-140 Ce-144 03/27/2024 03/27/2024 4

4 8

4 9

4 6

5 4

17 6

25 06/26/2024 06/26/2024 5

7 13 6

14 7

15 8

7 29 10 48 CL-07O 09/25/2024 -

09/25/2024 5

5 12 6

12 6

11 6

6 28 10 38 12/31/2024 -

12/31/2024 (1)

(1)

(1) 03/27/2024 03/27/2024 3

4 7

4 8

4 6

4 4

16 5

26 06/26/2024 06/26/2024 8

8 17 8

11 8

13 9

7 30 10 41 CL-12R 09/25/2024 09/25/2024 7

8 16 7

15 7

13 7

7 37 9

45 12/31/2024 -

12/31/2024 4

5 15 3

11 6

9 7

6 24 11 32 03/27/2024 03/27/2024 4

4 8

4 7

5 5

17 7

26 06/26/2024 06/26/2024 7

6 17 8

16 9

13 8

6 33 7

44 CL-12T 09/25/2024 09/25/2024 9

7 17 10 15 7

10 8

7 39 10 46 12/31/2024 -

12/31/2024 6

7 12 8

17 7

10 6

7 30 10 46 (1) See Sample Deviation Table

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 66 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 26, Semi-Annual Fish Gamma Isotopic (pCi/kg Wet+/- 2 Sigma)

Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 Ce-144 Dates Largemouth 05/16/2024 Bass 68

< 62

< 85

< 57

< 126

< 55

< 108

< 62

< 66

< 264

< 114 316 Bluegill 05/16/2024 51

< 67

< 115

< 90

< 123

< 58

< 68

< 55

< 58

< 236

< 61 206 Channel Catfish 05/16/2024

< 58

< 53

< 112

< 66

< 115

< 56

< 105

< 65

< 46

< 242

< 90 224 Carp 05/16/2024

< 52

< 62

< 121

< 69

< 156

< 68

< 123

< 75

< 68

< 270

< 77 306 CL-19 Blue Catfish 09/26/2024

< 73

< 83

< 133

< 83

< 154

< 80

< 140

< 58 72

< 655

< 199 301 Bluegill 09/26/2024

< 47

< 59

< 151 72

< 130

< 57

< 110

< 59

< 62

< 458

< 187 301 Common Carp 09/26/2024

< 69

< 59

< 131

< 64

< 149 77 71

< 56

< 49

< 638

< 168 228 Largemouth Bass 09/26/2024

< 76

< 84

< 216

< 83

< 164

< 89

< 164

< 79

< 75

< 847

< 259 419

Annual Radiological Environmental Operating Report YEAR: 2024 Page 67 of 79 Table 26, Semi-Annual Fish 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 Cs-134 Cs-137 Ba-140 La-140 Ce-144 Dates Largemouth 05/16/2024 Bass 53

< 49

< 87 91

< 114

< 42 77

< 53

< 55

< 205 51

< 200 Bluegill 05/16/2024

< 40

< 33

< 96

< 47

< 87 41

< 66

< 39

< 42

< 192

< 52

< 174 Crappie 05/16/2024

< 18

< 37

< 20

< 40

< 17

< 30

< 19

< 18

< 86

< 27

< 100 Carp 05/16/2024

< 48

< 42

< 62

< 55

< 83

< 42

< 80 51

< 42

< 223

< 52

< 211 CL-105 Bluegill 09/30/2024

< 54

< 53

< 155

< 79

< 102 81 141

< 70 72

< 574

< 187

< 292 Common Carp 09/30/2024 77

< 97

< 188 72

< 213

< 95

< 142

< 88

< 87

< 601

< 238

< 362 Largemouth Bass 09/30/2024

< 43

< 52

< 104

< 46

< 103

< 50

< 94

< 49

< 45

< 381

< 103

< 215 White Crappie 09/30/2024

< 69 72

< 203

< 64

< 160

< 69

< 108

< 86

< 53

< 508

< 159

< 337

Annual Radiological Environmental Operating Report YEAR: 2024 Page 68 of 79 Table 27, Semi-Annual Shoreline Sediment Gamma Isotopic (pCi/kg Dry+/- 2 Sigma)

Station Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140 Ce-144 Dates 05/16/2024

< 40

< 41

< 80

< 43

< 94 41

< 75

< 48

< 39

< 186

< 57

< 192 CL-07B 09/26/2024

< 32

< 35

< 93

< 37

< 80

< 37

< 69

< 39

< 32

< 219

< 67

< 192 05/16/2024

< 40

< 33

< 84

< 43

< 84

< 37

< 70

< 42

< 38

< 170

< 49 181 CL-105 09/30/2024

< 40

< 36

< 90

< 27

< 93

< 40

< 59 44

< 35

< 202

< 54

< 191

Annual Radiological Environmental Operating Report I YEAR: 2024 I

Page 69 of 79 Company: Constellation I Plant: Clinton Clean Energy Center, 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

Annual Radiological Environmental Operating Report YEAR: 2024 Page 70 of 79

~--------.--~--~-~--~------...,__

Com an : Constellation Plant: Clinton Clean Ener Center "Not Acceptable." TBE reported 168 pCi and the known value returned at 126 pCi.

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

Annual Radiological Environmental Operating Report YEAR: 2024 Page 71 of 79 added. Additionally, the beaker that aliquot is put in should have markings to indicate 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 72 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 28: 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 (a) 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(1)

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(1)

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 73 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 28: 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 74 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center Table 29: 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(4l 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(6l 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(7l 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 75 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 29: DOE's Mixed Analyte Performance Evaluation Program (MAPEP) Cont'd Teled:tne Brown Engineering Environmental Services Identification TSE Known Acceptance Evaluation Month/Year Matrix Nuclide Units Reported Value Number Value (a)

Range (b)

August2O24 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-23O 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-6O 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-9O 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) 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 23-31

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 76 of 79 Company: Constellation I Plant: Clinton Clean Energy Center Table 30: ERA Environmental Radioactivity Cross Check Program Teledyne Brown Engineering Environmental Services Identification TBE Known Acceptance Evaluation Month/Year Number Matrix Nuclide Units Reported Value<*>

Limits (b)

Value March 2024 MRAD-40 Water Am-241 pCi/L 101 139 95.4 - 178 A

Fe-55 pCi/L 2185 2480 1460- 3610 A

Pu-238 pCi/L 62.0 70.4 42.3 - 91.2 A

Pu-239 pCi/L 61.2 76.5 47.3 - 94.3 A

Soil Am-241 pCi/kg NR 1880 1020 - 2660 Pu-238 pCi/kg 667 512 255 - 778 A

Pu-239 pCi/kg 562 545 297 - 784 A

Sr-90 pCi/kg 4050 3630 1130 - 5650 A

U-234 pCi/kg 3040 4360 2040 - 5710 A

U-238 pCi/kg 3270 4320 2370 - 5800 A

AP Am-241 pCi/filter 38.8 55.0 39.3 - 73.3 N(1)

Fe-55 pCi/filter 387 386 141 - 616 A

Pu-238 pCi/filter 45.9 41.1 31.0 - 50.5 A

Pu-239 pCi/filter 54.9 56.1 41.9-67.7 A

U-234 pCi/filter 11.1 11.6 8.60 - 13.6 A

U-238 pCi/filter 12.8 11.5 8.68-13.7 A

GR-A pCi/filter 116 95.9 50.1 -158 A

GR-B pCi/filter 42.1 22.2 13.5 - 33.5 N<2>

April 2024 RAD-137 Water Ba-133 pCi/L 62.8 65.9 50.1 -81.7 A

Cs-134 pCi/L 51.0 57.8 42.8 - 72.8 A

Cs-137 pCi/L 153 186 149 - 223 A

Co-60 pCi/L 92.1 98.8 79.7-1 18 A

Zn-65 pCi/L 208 240 188 - 292 A

GR-A pCi/L 35.2 52.6 39.6 - 65.6 Nl3l GR-B pCi/L 49 46.5 33.9 - 59.1 A

U-Nat pCi/L 56.0 59.3 52.8-65.8 A

H-3 pCi/L 19,000 21,300 18,200 - 24,400 A

Sr-89 pCi/L 48.9 52.2 37.8 - 66.6 A

Sr-90 pCi/L 32.6 37.6 32.0 -43.2 A

1-131 pCi/L 21.8 25.1 21.7 - 28.5 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 Umits 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 I Page 77 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center, Environmental Direct Radiation Dosimetry Results Ba+ MDDa Quarterly Normalized Quarterly Monitoring Data, Ma Monitoring

Baseline, Location Ba (mrem)

(mrem)

(mrem) 1 2

3 4

CL-01 18.5 25.1 18.9 22.1 17.5 18.9 CL-02 19.2 25.8 20.4 21.4 20.1 19.5 CL-03 18.7 25.3 18 19.2 17.1 18.7 CL-04 18.2 24.8 17.8 17.9 17.1 18.5 CL-05 19.1 25.7 18.7 19.6 18.4 18.3 CL-06 16.5 23.1 14.5 18.4 16.1 18.8 CL-07 17.4 24 17.7 19.5 17 17.4 CL-08 18.5 25.1 17.2 19.9 18.3 18.6 CL-11 17.3 23.9 18.5 18.8 13.9 18 CL-1141'1 18.1 24.7 20.8 17.9 18 21.2 CL-15 16.6 23.2 14.5 16.8 15.8 17.9 CL-22 19.4 26 18.8 21 17.9 19.7 CL-23 20.4 27 17.8 21.6 17.9 18.7 CL-24 20.1 26.7 19.1 23.2 17.4 19.8 CL-33 19.8 26.4 17.6 21.4 15.6 19.8 CL-34 19.4 26 19.2 18.7 15.9 18.5 CL-35 17.9 24.5 19 17.1 18.3 19.2 CL-36 18.6 25.2 18 21.9 15.1 18.6 CL-37 17.8 24.4 17.1 19.3 17.6 19.3 CL-41 19.8 26.4 18.3 23.3 18 20.2 MDDa = Quarterly Minimum Differential Dose= 6.6 mrem MDDA = Annual Minimum Differential Dose= 9.5 mrem ND = Not Detected, where Ma~ (Ba+MDDa) or MA~ (BA+MDDA)

Quarterly Facility Dose, Fa=Ma-Ba (mrem, or "ND" if Fa :S MDDa) 1 2

3 4

ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND (1)

(1)

ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND BA+

MDDA Annual

Baseline, BA (mrem)

(mrem) 74 83.5 76.7 86.2 74.7 84.2 72.8 82.3 76.5 86 65.8 75.3 69.5 79 74 83.5 69.3 78.8 72.3 81.8 66.3 75.8 77.6 87.1 81.5 91 80.5 90 79.2 88.7 77.5 87 71.6 81.1 74.2 83.7 71.1 80.6 79.4 88.9 Annual Monitoring Data, MA (mrem) 77.4 81.4 73 71.3 75 67.8 71.6 74 69.2 77.9 65 77.4 76 79.5 74.4 72.3 73.6 73.6 73.3 79.8 (1) The location of CL-114 was changed when the location of CL-114 garden location was changed. The data collected during the 2023 year was collected to begin the 5-year baseline of the location. There is no requirement in the ODCM to have this location monitored, and there is not a requirement in ANSI/HPS 13.37. CL-114 a supplemental monitoring location Annual Facility

Dose, FA=MA-BA (mrem, or "ND" if FA:S MDDA)

ND ND ND ND ND ND ND ND ND (1)

ND ND ND ND ND ND ND ND ND ND

Annual Radiological Environmental Operating Report I YEAR: 2024 I Page 78 of 79 Company: Constellation I Plant: Clinton Clean Enerav Center, Environmental Direct Radiation Dosimetry Results Ba+ MDDa Quarterly Normalized Quarterly Monitoring Data, Ma Monitoring

Baseline, Location Ba CL-42 CL-43 CL-44 CL-45 CL-46 CL-47 CL-48 CL-49 CL-51 CL-52 CL-53 CL-54 CL-55 CL-56 CL-57 CL-58 CL-60 CL-61 CL-63 (mrem)

(mrem)

(mrem) 1 2

3 4

18.6 25.2 15.7 20.4 17.6 19.6 19.9 26.5 19.8 21.9 19.7 20.9 18.9 25.5 18.3 21.1 21.4 18.9 20.2 26.8 20.6 19.8 19.9 20.8 19.2 25.8 16.6 18.7 16.4 19.3 19.9 26.5 17.1 20.6 17.2 19.6 18.6 25.2 17.9 19.1 17.2 20 20 26.6 20.8 21.9 20.3 20.2 20.2 26.8 19.8 18.9 19.9 19 19.9 26.5 19.1 22 18.7 18.8 18 24.6 17.7 16.4 18.8 19 19.5 26.1 18.6 19.5 16.9 17.1 19.7 26.3 19.4 20.5 17.9 21.1 20.3 26.9 18.5 19.4 19.6 22 20.4 27 17.3 20.7 (2) 21.1 19.8 26.4 18.3 21.4 17.9 19.1 19.8 26.4 17.6 18.7 18.9 18.1 19.5 26.1 17.4 19.2 15 17.4 16.7 23.3 17.9 17.7 16.4 18.1 MDD0 = Quarterly Minimum Differential Dose= 6.6 mrem MDDA = Annual Minimum Differential Dose= 9.5 mrem ND = Not Detected, where Mo~ (Bo+MDDo) or MA~ (BA+MDDA)

(2) Refer to Sample Deviations Table Quarterly Facility Dose, Fa=Ma-Ba (mrem, or "ND" if FaS MDDa) 1 2

3 4

ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND BA+

MDDA Annual

Baseline, BA (mrem)

(mrem) 74.2 83.7 79.7 89.2 75.4 84.9 80.6 90.1 73 82.5 79.4 88.9 74.2 83.7 79.8 89.3 76.6 86.1 75.6 85.1 71.9 81.4 78 87.5 78.7 88.2 81 90.5 81.6 91.1 79.1 88.6 79 88.5 78.1 87.6 66.6 76.1 Annual Facility

Dose, Annual FA=MA-BA Monitoring (mrem, Data, MA or "ND" (mrem) if FAS MDDA) 73.3 ND 82.3 ND 79.7 ND 81.1 ND 71 ND 74.5 ND 74.2 ND 83.2 ND 77.6 ND 78.6 ND 71.9 ND 72.1 ND 78.9 ND 79.5 ND 78.8 ND 76.7 ND 73.3 ND 69 ND 70.1 ND

Annual Radiological Environmental Operating Report YEAR: 2024, Environmental Direct Radiation Dosimetry Results Ba+ MDDa Quarterly Normalized Quarterly Monitoring Data, Ma Monitoring

Baseline, Location Ba (mrem)

(mrem)

(mrem) 1 2

3 CL-64 19 25.6 20.1 20.5 18.7 CL-65 20.1 26.7 20.5 20.6 18.4 CL-74 17 23.6 18.4 18.3 16.4 CL-75 18.9 25.5 17.5 20.9 16.5 CL-76 19.7 26.3 18.3 20.1 20.7 CL-77 18.1 24.7 15.4 18.8 14.6 CL-78 18 24.6 18.2 20.3 18.3 CL-79 19.3 25.9 19.6 21.5 20.1 CL-80 18.9 25.5 19 22.1 16.6 CL-81 19.2 25.8 15.9 20.4 16 CL-84 19.1 25.7 19.4 21.6 15.6 CL-90 15.6 22.2 13.7 16.8 11.9 CL-91 17.4 24 16.6 19.1 13.9 CL-97 19.4 26 19.1 20.4 17.2 CL-99 15.1 21.7 16.1 17.6 15.2 MDDa = Quarterly Minimum Differential Dose= 6.6 mrem MDDA = Annual Minimum Differential Dose = 9.5 mrem 4

17.6 18.1 17.4 17.8 19.6 18.8 19 19.5 18.2 17.9 18.7 15 17.3 18 16.5 ND = Not Detected, where Ma $ (Ba+MDDa) or MA$ (BA+MDDA)

Quarterly Facility Dose, Fa=Ma-Ba (mrem, or "ND" if FaS MDDa) 1 2

3 4

ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Page 79 of 79 Annual BA+

Facility MDDA

Dose, Annual Annual FA=MA-BA

Baseline, Monitoring (mrem, BA Data, MA or "ND" (mrem)

(mrem) if (mrem)

FAS MDDA) 75.9 85.4 76.9 ND 80.5 90 77.6 ND 68 77.5 70.5 ND 75.7 85.2 72.7 ND 78.7 88.2 78.7 ND 72.2 81.7 67.6 ND 72 81.5 75.8 ND 77.1 86.6 80.7 ND 75.5 85 75.9 ND 76.8 86.3 70.2 ND 76.3 85.8 75.3 ND 62.2 71.7 57.4 ND 69.5 79 66.9 ND 77.6 87.1 74.7 ND 60.6 70.1 65.4 ND

Intentionally left blank

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page O of 22 Company: Constellation I Plant: Clinton Clean Enerav Center Annual Radiological Groundwater Protection Program Report 2024 Document Number: 50-461

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 1 of 22 Company: Constellation I Plant: Clinton Clean Energy Center TABLE OF CONTENTS 1.0 LIST OF ACRONYMS AND DEFINITIONS................................................................................ 2

2.0 INTRODUCTION

........................................................................................................................ 4 2.1 About Nuclear Power...................................................................................................... 4 2.2 About Radiation Dose..................................................................................................... 6 2.3 About Dose Calculation.................................................................................................. 8 3.0 NEI 07-07 ONSITE RADIOLOGICAL GROUNDWATER MONITORING PROGRAM............... 10 3.1 Voluntary Notification.................................................................................................... 21 4.0 BIBLIOGRAPHY...................................................................................................................... 22 TABLES Table 1, Groundwater Protection Program Monitoring Well Sampling Locations.................................. 10 Table 2, Groundwater Protection Monitoring Well Tritium and Strontium in Ground Water Samples (pCi/L +/- 2 sigma)................................................................................................................................. 16 Table 3, Groundwater Protection Program Monitoring Well Gamma Isotopic in Groundwater Samples (pCi/L +/- 2 sigma)................................................................................................................................. 18 Table 4, Groundwater Protection Program Monitoring Well Tritium in Surface Water Samples (pCi/L +/- 2 sigma).................................................................................................................................................. 19 Table 5, Groundwater Protection Program Monitoring Well Tritium in Precipitation Water Samples (pCi/L +/- 2 sigma)................................................................................................................................. 20 FIGURES Figure 1, Pressurized Water Reactor (PWR) [1]..................................................................................... 4 Figure 2, Boiling Water Reactor (BWR) [2]............................................................................................. 5 Figure 3, Sources of Radiation Exposure (NCRP Report No. 160) [3].................................................... 6 Figure 4, Potential exposure pathways to Members of the Public due to Plant Operations [6]............... 8 Figure 5, Onsite Sampling Locations at Clinton Power Station, 2024................................................... 12 Figure 6, Sampling Locations South of Clinton Power Station, 2024.................................................... 13 Figure 7, Sampling Locations East of Clinton Power Station, 2024...................................................... 14 Figure 8, Recapture Sampling Locations of Clinton Power Station, 2024............................................. 15

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 2 of 22 Company: Constellation I Plant: Clinton Clean Energy Center 1.0 LIST OF ACRONYMS AND DEFINITIONS

1.

Alpha Particle (a): A charged particle emitted from the nucleus of an atom having a mass and charge equal in magnitude of a helium nucleus.

2.

BWR: Boiling Water Reactor

3.

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.

4.

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.

5.

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

6.

Curie (Ci): A measure of radioactivity; equal to 3. 7 x 1010 disintegrations per second, or 2.22 x 1012 disintegrations per minute.

7.

Direct Radiation Monitoring: The measurement of radiation dose at various distances from the plant is assessed using thermoluminescent dosimeters (TLDs), optically stimulated luminescent dosimeters (OSLDs), and/or pressurized ionization chambers.

8.

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

9.

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

10.

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.

11.

ISFSI: Independent Spent Fuel Storage Installation

12.

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 NRG and are typically listed in the ODCM.

13.

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.

Annual Radiological Groundwater Protection Program Report J

YEAR: 2024 J

Page 3 of 22 Company: Constellation I Plant: Clinton Clean Energy Center

14.

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

15.

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

16.

Microcurie (µCi): 3. 7 x 104 disintegrations per second, or 2.22 x106 disintegrations per minute.

17.

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

18.

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

19.

N/A: Not Applicable

20.

NEI: Nuclear Energy Institute

21.

NRC: Nuclear Regulatory Commission

22.

ODCM: Offsite Dose Calculation Manual

23.

OSLO: Optically Stimulated Luminescence Dosimeter

24.

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.

25.

PWR: Pressurized Water Reactor

26.

REC: Radiological Effluent Control

27.

REMP: Radiological Environmental Monitoring Program

28.

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.

29.

TEDE: Total Effective Dose Equivalent (TEDE) means the sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures).

30.

TLD: Thermoluminescent Dosimeter 31.

TRM: Technical Requirements Manual

32.

TS: Technical Specification

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 4 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center

33.

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

2.0 INTRODUCTION

2.1 About Nuclear Power Commercial nuclear power plants are generally classified as either Boiling Water Reactors (BWRs) or Pressurized Water Reactors (PWRs), based on their design. A BWR includes a single coolant system where water used as reactor coolant boils as it passes through the core and the steam generated is used to turn the turbine generator for power production. A PWR, in contrast, includes two separate water systems: radioactive reactor coolant and a secondary system. Reactor coolant is maintained under high pressure, preventing boiling. The high-pressure coolant is passed through a heat exchanger called a steam generator where the secondary system water is boiled, and the steam is used to turn the turbine generator for power production.

Containment Structll"e Figure 1, Pressurized Water Reactor (PWR) [1]

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 5 of 22 Company: Constellation I Plant: Clinton Clean Energy Center 2.1 Containment Structure Control Rods Figure 2, Boiling Water Reactor (BWR) [2]

Electricity is generated by a nuclear power plant similarly to the way that electricity is generated at other conventional types of power plants, such as those powered by coal or natural gas. Water is boiled to generate steam; the steam turns a turbine that is attached to a generator and the steam is condensed back into water to be returned to the boiler. What makes nuclear power different from these other types of power plants is that the heat is generated by fission and decay reactions occurring within and around the core containing fissionable uranium (U-235).

Nuclear fission occurs when certain nuclides (primarily U-233, U-235, or Pu-239) absorb a neutron and break into several smaller nuclides (called fission products) as well as producing some additional neutrons.

Fission results in production of radioactive materials including gases and solids that must be contained to prevent release or treated prior to release. These effluents are generally treated by filtration and/or hold-up prior to release. Releases are generally monitored by sampling and by continuously indicating radiation monitors. The effluent release data is used to calculate doses in order to ensure that dose to the public due to plant operation remains within required limits.

Annual Radiological Groundwater Protection Program Report YEAR: 2024 Page 6 of 22 2.2 About Radiation Dose Ionizing radiation, including alpha, beta, and gamma radiation from radioactive decay, has enough energy to break chemical bonds in tissues and result in damage to tissue or genetic material. The amount of ionization that will be generated by a given exposure to ionizing radiation is quantified as dose. Radiation dose is generally reported in units of millirem (mrem) in the US.

Computed tomography (medical)

(24%)

Terrestrial (background)

(3%)

Nuclear medicine (medical)

(12%)

Space Internal {background)

(background)

(S3/4)

(5%)

lnterventional fluoroscopy (medical)

(7%)

Radon & thoron

{background)

(37%)

Industrial

(<0.1%)

Occupational

(<0.1%)

Consumer Conventional radiography/fluoroscopy (medical)

(5%)

(2%)

Figure 3, Sources of Radiation Exposure (NCRP Report No. 160) [3]

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 7 of 22 Company: Constellation I Plant: Clinton Clean Energy Center The National Council on Radiation Protection (NCRP) has evaluated the population dose for the US and determined that the average individual is exposed to approximately 620 mrem per year [3). There are many sources for radiation dose, ranging from natural background sources to medical procedures, air travel, and industrial processes. Approximately half (310 mrem) of the average exposure is due to natural sources of radiation including exposure to radon, cosmic radiation, and internal radiation and terrestrial due to naturally occurring radionuclides. The remaining 310 mrem of exposure is due to man-made sources of exposure, with the most significant contributors being medical (48% of total mrem per year) due to radiation used in various types of medical scans and treatments. Of the remaining 2%

of dose, most is due to consumer activities such as air travel, smoking cigarettes, and building materials. A small fraction of this 2% is due to industrial activities including generation of nuclear power.

Readers that are curious about common sources and effects of radiation dose that they may encounter can find excellent sources of information from the Health Physics Society, including the Radiation Fact Sheets [4], and from the US Nuclear Regulatory Commission website [5].

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 8 of 22 Company: Constellation I Plant: Clinton Clean Energy Center 2.3 About Dose Calculation Concentrations of radioactive material in the environment resulting from plant operations are very small and it is not possible to determine doses directly using measured activities of environmental samples. To overcome this, dose calculations based on measured activities of effluent streams are used to model the dose impact for Members of the Public due to plant operation and effluents. There are several mechanisms that can result in dose to Members of the Public, including: Ingestion of radionuclides in food or water; Inhalation of radionuclides in air; Immersion in a plume of noble gases; and Direct Radiation from the ground, the plant or from an elevated plume.

,l}cpo~ition Gascou. cffiucnts Inge. tionp;;..~'ll>

~

I 0

- . lnhalntion

\\

A**** ln~c *tion

\\ Dcpo. it ion t

\\

/

- - - - Agricultur, 0 °~0 Public

*.jt Soil

~

Soil

I n c~tton **.

o

Radionuclidcs

.... : Behavior of radionuclides Figure 4, Potential exposure pathways to Members of the Public due to Plant Operations [6]

Each plant has an Offsite Dose Calculation Manual (ODCM) that specifies the methodology used to obtain the doses in the Dose Assessment section of this report.

The dose assessment methodology in the ODCM is based on NRC Regulatory Guide 1.109 [7] and NUREG-0133 [8]. Doses are calculated by determining what the nuclide concentration will be in air, water, on the ground, or in food products based on plant effluent releases. Release points are continuously monitored to quantify what concentrations of nuclides are being released. For gaseous releases meteorological data is used to determine how much of the released activity will be present at a given location outside of the plant either deposited onto the ground or in gaseous form.

Intake patterns and nuclide bio-concentration factors are used to determine how much activity will be transferred into animal milk or meat. Finally, human ingestion factors and dose factors are used to determine how much activity will be consumed and how much dose the consumer will receive. Inhalation dose is calculated by determining the concentration of nuclides and how much air is breathed by the individual.

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 9 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center For liquid releases, dilution and mixing factors are used to model the environmental concentrations in water. Drinking water pathways are modeled by determining the concentration of nuclides in the water at the point where the drinking water is sourced (e.g., taken from wells, rivers, or lakes). Fish and invertebrate pathways are determined by using concentration at the release point, bioaccumulation factors for the fish or invertebrate and an estimate of the quantity of fish consumed.

Each year a Land Use Census is performed to determine what potential dose pathways currently exist within a five-mile radius around the plant, the area most affected by plant operations. The Annual Land Use Census identifies the locations of vegetable gardens, nearest residences, milk animals and meat animals. The data from the census is used to determine who is the likely to be most exposed to radiation dose as a result of plant operation.

There is significant uncertainty in dose calculation results, due to modeling dispersion of material released and bioaccumulation factors, as well as assumptions associated with consumption and land-use patterns. Even with these sources of uncertainty, the calculations do provide a reasonable estimate of the order of magnitude of the exposure. Conservative assumptions are made in the calculation inputs such as the number of various foods and water consumed, the amount of air inhaled, and the amount of direct radiation exposure from the ground or plume, such that the actual dose received are likely lower than the calculated dose. Even with the built-in conservatism, doses calculated for the maximum exposed individual due to plant operation are a very small fraction of the annual dose that is received due to other sources. The calculated doses due to plant effluents, along with REMP results, serve to provide assurance that radioactive effluents releases are not exceeding safety standards for the environment or people living near the plant.

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 10 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center 3.0 NEI 07-07 ONSITE RADIOLOGICAL GROUNDWATER MONITORING PROGRAM Clinton Clean Energy Center has developed a Groundwater Protection Initiative (GPI) program in accordance with NEI 07-07, Industry Ground Water Protection Initiative -

Final Guidance Document [9]. 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, Clinton 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 should be reported as part of ARERR.

Table 1, Groundwater Protection Program Monitoring Well Sampling Locations Site Site Type B-3 Monitoring Well MW-CL-1 Monitoring Well MW-CL-2 Monitoring Well MW-CL-121 Monitoring Well MW-CL-131 Monitoring Well MW-CL-13S Monitoring Well MW-CL-14S Monitoring Well MW-CL-151 Monitoring Well MW-CL-15S Monitoring Well MW-CL-16S Monitoring Well MW-CL-17S Monitoring Well MW-CL-181 Monitoring Well MW-CL-18S Monitoring Well MW-CL-19S Monitoring Well MW-CL-20S Monitoring Well MW-CL-21S Monitoring Well MW-CL-22S Monitoring Well RG-E Precipitation Water RG-ENE Precipitation Water RG-ESE Precipitation Water

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 11 of 22 Company: Constellation I Plant: Clinton Clean Energy Center Table 1, Groundwater Protection Program Monitoring Well Sampling Locations Cont'd Site Site Type RG-N Precipitation Water RG-NE Precipitation Water RG-NNW Precipitation Water RG-S Precipitation Water RG-SE Precipitation Water RG-SW Precipitation Water RG-SW2 Precipitation Water RG-W Precipitation Water RG-WNW Precipitation Water RG-WSW Precipitation Water

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 12 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center MAP OF COLLECTION SITES Figure 5, Onsite Sampling Locations at Clinton Power Station, 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 13 of 22 Company: Constellation I Plant: Clinton Clean Energy Center Figure 6, Sampling Locations South of Clinton Power Station, 2024

Annual Radiological Groundwater Protection Program Report l YEAR: 2024 I Page 14 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center 0

Figure 7, Sampling Locations East of Clinton Power Station, 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 15 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center 0

oo 900 2023 aprurc SafT"()le loca n

I pCIJl d'ion rec.a life s.an collect In nu ry rd June, 20H Figure 8, Recapture Sampling Locations of Clinton Power Station, 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 16 of 22 Company: Constellation I Plant: Clinton Clean Energy Center 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 analyzed for gross alpha, gamma, or HTD in 2024.

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

Collection Date H-3 Sr-89 B-3 4/24/2024

< 196 MW-CL-121 3/13/2024

< 186 MW-CL-121 4/24/2024

< 199

< 8 MW-CL-121 8/27/2024

< 189 MW-CL-121 10/30/2024

< 189 MW-CL-13S 3/13/2024

< 181 MW-CL-13S 4/24/2024

< 196

< 5 MW-CL-13S 8/27/2024

< 191 MW-CL-13S 10/30/2024

< 191 MW-CL-14S 3/14/2024 659

+/-

150 MW-CL-14S 3/14/2024 791 165

+/-

Reanalysis MW-CL-14S 4/25/2024 471

+/-

139

< 3 MW-CL-14S 8/28/2024

< 190 MW-CL-14S 10/31/2024 190 MW-CL-16S 3/14/2024

< 182 MW-CL-16S 4/25/2024 218

+/-

129

< 4 MW-CL-16S 8/28/2024

< 192 MW-CL-16S 10/31/2024

< 189 MW-CL-17S 3/14/2024

< 184 MW-CL-17S 4/25/2024

< 196

< 3 MW-CL-17S 8/28/2024

< 185 MW-CL-17S 10/31/2024

< 184 MW-CL-181 3/14/2024

< 185 MW-CL-181 4/25/2024

< 195

< 5 MW-CL-181 8/28/2024

< 190 MW-CL-181 10/31/2024

< 190 MW-CL-18S 3/14/2024

< 187 MW-CL-18S 4/25/2024

< 194

< 4 MW-CL-18S 8/28/2024

< 184 MW-CL-18S 10/31/2024

< 188 MW-CL-19S 3/13/2024

< 179 MW-CL-19S 4/24/2024

< 194

< 9 MW-CL-19S 8/27/2024

< 194 MW-CL-19S 10/30/2024

< 194 Sr-90

< 0.8

< 0.9

< 0.8

< 0.9

< 0.7

< 0.8

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 17 of 22 Company: Constellation I Plant: Clinton Clean Energy Center 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-CL-21S 3/13/2024

< 188 MW-CL-21S 4/24/2024

< 198 9

< 0.8 MW-CL-21S 8/27/2024

< 191 MW-CL-21S 10/30/2024

< 188 MW-CL-22S 3/14/2024

< 183 MW-CL-22S 4/25/2024

< 198 3

< 0.9 MW-CL-22S 8/28/2024

< 189 MW-CL-22S 10/31/2024

< 191 MW-CL-1 4/24/2024

< 194 MW-CL-131 4/24/2024

< 196 MW-CL-151 4/24/2024

< 198 MW-CL-15S 4/24/2024

< 196 MW-CL-2 4/24/2024

< 197 MW-CL-20S 4/24/2024

< 193

Site Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 18 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center Table 3, Groundwater Protection Program Monitoring Well Gamma Isotopic in Groundwater Samples (pCi/L +/- 2 sigma)

Collection Date Be-7 K-40 Co-58 Fe-59 Co-60 Zn-65 Nb-96 Zr-95 Cs-134 Cs-137 Ba-140 La-140 No Groundwater Samples Analyzed for Gamma Isotopic in 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 19 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center Table 4, Groundwater Protection Program Monitoring Well Tritium in Surface Water Samples (pCi/L +/- 2 sigma)

No Surface Water Samples Analyzed for Tritium in 2024

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 20 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center Table 5, Groundwater Protection Program Monitoring Well Tritium in Precipitation Water Samples (pCi/L +/- 2 sigma)

Site Collection Date H-3 RG-E 10/1/2024

< 192 RG-E 11/20/2024

< 193 RG-ENE 10/1/2024

< 192 RG-ENE 11/20/2024 309

+/-

132 RG-ESE 10/1/2024

< 194 RG-ESE 11/20/2024

< 188 RG-N 10/1/2024

< 186 RG-N 11/20/2024

< 192 RG-NE 10/1/2024

< 190 RG-NE 11/20/2024

< 189 RG-NNW 10/1/2024

< 195 RG-NNW 11/20/2024

< 181 RG-S 10/1/2024

< 192 RG-S 11/20/2024

< 188 RG-SE 10/1/2024 205

+/-

127 RG-SE 11/20/2024 196

+/-

126 RG-SW 10/1/2024

< 191 RG-SW 11/20/2024

< 192 RG-SW2 10/1/2024

< 192 RG-SW2 11/20/2024 292

+/-

125 RG-W 10/1/2024

< 193 RG-W 11/20/2024

< 177 RG-WNW 10/1/2024

< 191 RG-WNW 11/20/2024

< 179 RG-WSW 10/1/2024

< 191 RG-WSW 11/20/2024

< 179

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 21 of 22 Company: Constellation I Plant: Clinton Clean Enerav Center 3.1 Voluntary Notification During 2024, Clinton Clean Energy Center did not make a voluntary NEI 07-07 notification to State/Local officials, NRG, and to other stakeholders required by site procedures.

Annual Radiological Groundwater Protection Program Report I YEAR: 2024 I Page 22 of 22 Company: Constellation I Plant: Clinton Clean Energy Center 4.0 BIBLIOGRAPHY

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

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

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

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

[Accessed 2020].

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

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

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

[7] "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.

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

Nuclear Regulatory Commission, 1987.

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

Final Guidance Document, Rev. 1,"

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

U-604832, 2024 Annual Radiological Environmental Operation Report

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U-604832, 2024 Annual Radiological Environmental Operation Report

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Subject:

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SUMMARY

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2.0 INTRODUCTION

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