ML25107A293

Independent Spent Fuel Storage Installation (ISFSI) - Annual Radiological Environmental Operating Report

ML25107A293
Person / Time
Site:	North Anna
Issue date:	04/17/2025
From:	Hilbert L Virginia Electric & Power Co (VEPCO)
To:	Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation, Document Control Desk
References
25-094
Download: ML25107A293 (1)

Text

{{#Wiki_filter:VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 April 17, 2025 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Serial No. 25-094 NAPS: RAP Docket Nos. 50-338/339 72-16 72-56 License Nos. NPF-4/7 SNM-2507 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION ENERGY VIRGINIA) NORTH ANNA POWER STATION UNIT NOS. 1 AND 2 INDEPENDENT SPENT FUEL STORAGE INSTALLATION {ISFSI) ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT In accordance with North Anna Units 1 and 2 Technical Specification 5.6.2 and the North Anna Independent Spent Fuel Storage Installation Technical Specification 5.5.2, enclosed is the 2024 Annual Radiological Environmental Operating Report. The Radiological Environmental Operating Report provides the details associated with the Radiological Environmental Monitoring Program. If you have any questions or require additional information, please contact Mr. Marcus A. Hofmann at (540) 894-2100. Very truly yours, 4~ Lisa Hilbert Site Vice President Enclosure Commitments made in this letter: None cc: Mark Miller - Region II Director, Division of Spent Fuel Management NRC Senior Resident Inspector North Anna Power Station

Dominion Energy North Anna Power Station Radiological Environmental Monitoring Program January 1, 2024 to December 31, 2024 Prepared by Dominion Energy, North Anna Power Station

Prepared by: Reviewed by: Approved by: Annual Radiological Environmental Operating Report North Anna Power Station January 1, 2024 to December 31, 2024 ryant anrique Supervisor Radiological Analysis and Instrumentation Dominion Energy North Anna Power Station Bradley Pleasants Superintendent Health Physics Technical Services George R. Simmons Manager Radiological Protection and Chemistry Dominion Energy North Anna Power Station 2

Table of Contents

1. EXECUTIVE

SUMMARY

.............................................................................................................. 4

2. PROGRAM DESCRIPTION............................................................................................................ 6 2.1 Introduction............................................................................................................................. 6 2.2 Sampling and Analysis Program............................................................................................. 7

3. ANALYTICAL RESULTS............................................................................................................ 21 3.1 Summary of Results.............................................................................................................. 21 3.2 Analytical Results of 2024 REMP Samples.......................................................................... 28

4. DISCUSSION OF RESULTS......................................................................................................... 56 4.1 Gamma Exposure Rate......................................................................................................... 56 4.2 Airborne Gross Beta.............................................................................................................. 57 4.3 Airborne Radioiodine............................................................................................................. 58 4.4 Air Particulate Gamma......................................................................................................... 59 4.5 Air Particulate Strontium...................................................................................................... 59 4.6 Soil........................................................................................................................................ 59

4. 7 Precipitation.......................................................................................................................... 59 4.8 Cow Milk.............................................................................................................................. 59 4.10 Well Water.......................................................................................................................... 59 4.11 RiverWater......................................................................................................................... 60 4.12 Surface Water....................................................................................................................... 60 4.13 Bottom Sediment................................................................................................................ 61 4.14 Shoreline Soil...................................................................................................................... 62 4.15 Fisl1...................................................................................................................................... 62

5. PROGRAM EXCEPTIONS........................................................................................................... 63 REFERENCES.................................................................................................................................... 64 APPENDICES..................................................................................................................................... 65 APPENDIX A: LAND USE CENSUS............................................................................................... 66 All listed distances are in miles....................................................................................................... 67 3

1. EXECUTIVE

SUMMARY

This document is a detailed report of the 2024 North Anna Nuclear Power Station Radiological Environmental Monitoring Program (REMP). It is submitted in accordance with North Anna Unit 1 and 2 Technical Specification 5.6.2 and North Anna Independent Spent Fuel Storage Installation (ISFSI) Technical Specification 5.5.2. Radioactivity levels from January 1 through December 31, 2024, in water, silt, shoreline sediment, aquatic biota, food products, vegetation, and direct exposure pathways have been analyzed, evaluated and summarized. The REMP is designed to confirm that radiological effluent releases are As Low As Reasonably Achievable (ALARA), no undue environmental effects occur, and the health and safety of the public are protected. The program also detects any unexpected environmental processes that could allow radiation accumulations in the environment or food pathway chains. Radiation and radioactivity in the environment are monitored within a 25-mile radius of the station. North Anna Power Station (NAPS) personnel collect a variety of samples within this area. A number of sampling locations for each medium are selected using available meteorological, land use, and water use data. Two types of samples are obtained. Control samples are collected from areas that are beyond the measurable influence of North Anna Power Station (NAPS) or any other nuclear facility. These samples are used as reference data. Normal background radiation levels, or radiation present due to causes other than North Anna Power Station (NAPS), can be compared to the environment sunounding the station. Indicator samples are the second sample type obtained. These samples show how much radiation is contributed to the environment by the station. Indicator samples are taken from areas close to the station where any station contribution will be at the highest concentration. Prior to station operation, samples were collected and analyzed to determine the amount of radioactivity present in the area. The resulting values are used as a "pre-operational baseline." Analysis results from the indicator samples are compared to both cunent control sample values and the pre-operational baseline to determine if changes in radioactivity levels are attributable to station operations, or causes such as the Chernobyl accident, Fukushima Daiichi or natural variation. Radiation Detection Company provided thermoluminescent dosimetry (TLD) services and Teledyne Brown Engineering Environmental Services provided radioanalytical services. Participation in an Interlaboratory Comparison Program provides an independent check of sample measurement precision and accuracy. Typically, radioactivity levels in the environment are so low that analysis values frequently fall below the minimum detection limits of state-of-the-art measurement methods. Because of this, the Nuclear Regulatory Commission (NRC) requires equipment used for radiological environmental monitoring be able to detect specified minimum Lower Limits of Detection (LLDs ). This ensures that analyses are as accurate as possible. The NRC also mandates a reporting level for certain radionuclides. Licensed nuclear facilities must report the radionuclide activities in those environmental samples that are equal to or greater than the specified reporting level. Environmental radiation levels are sometimes refened to as a percent of the reporting level. Analytical results are reported for all possible radiation exposure pathways to man. These pathways include airborne, water, aquatic, terrestrial, and direct radiation exposure. The airborne exposure pathway includes radioactive airborne iodine and paiiiculates, and precipitation. The 2024 airborne results were similar to previous years. Fallout or natural radioactivity levels remained at levels consistent with past years' results. Water and aquatic exposure pathway samples include precipitation, surface, river and well water, silt and shoreline sediments, and fish. The average tritium activity in surface water for 2024 was 4713 pCi/liter. No other plant related isotopes were reported in any surface or river water. River water collected from the North Anna River, 5.8 miles downstream of the site had an average tritium level of 4023 pCi/liter. No plant related isotopes were detected in quarterly precipitation samples. Silt samples indicated the presence of naturally 4

occurring potassium-40 and thorium and uranium decay daughters at levels consistent with the natural background. Plant related isotope, Cs-13 7, was not identified in any indicator sample during the reporting period. The detection of Cs-13 7 in bottom sediment is historically common with positive indication usually apparent in both indicator and control samples. During the pre-operational period sediment samples were also analyzed by gamma spectroscopy. Levels during this phase varied by location and date and averaged 360 pCi/kg. Shoreline soil, which may provide a direct exposure pathway, indicated the presence of potassium-40 and thorium and uranium decay daughters also at levels consistent with natural levels. No plant related isotope was detected in the indicator or control locations in shoreline soil. No plant related isotope was detected in fish samples from either Lake Anna or the control location, Lake Orange. Soil samples, which are collected every three years from twelve stations, were not scheduled to be collected in 2024. During the preoperational phase Cs-13 7 was routinely detected and was attributed to fallout. Levels during this phase varied by location and date and ranged from 88 to 1390 pCi/Kg. The average was 645 pCi/kg. The terrestrial exposure pathway includes milk and food/vegetation products. No milk samples were obtained during the reporting period since the last operating dairy farm within the sampling area closed on O 1/01/2018 rendering milk samples unavailable. No plant related isotope was detected in any vegetation sample. The direct exposure pathway measures environmental radiation doses by use of thermoluminescent dosimeters (TLDs). TLD results have remained essentially constant over the years. During 2024, as in previous years, operation of the North Anna Power Station and the Independent Spent Fuel Storage Installation (ISFSI) created no adverse environmental effects or health hazards. The maximum total body dose calculated for a hypothetical individual at the station site boundary due to liquid and gaseous effluents released from the station during 2024 was 0.583 millirem. For reference, this dose may be compared to the 620 millirem average annual exposure to every person in the United States from natural and man-made sources. Natural background sources in the environment provide approximately 50% of radiation exposure to man, while medical uses provide approximately 48%. By comparison, nuclear power contributes less than 0.1 %. These results demonstrate not only compliance with federal and state regulations but also demonstrate the adequacy of radioactive effluent control at Nolih Anna Power Station. 5

2. PROGRAM DESCRIPTION 2.1 Introduction This report documents the 2024 North Anna Power Station operational Radiological Environmental Monitoring Program (REMP).

The North Anna Power Station of Virginia Electric and Power Company (Dominion Energy) is located on Lake Anna in Mineral, Virginia, approximately 35 miles southwest of Fredericksburg, Virginia. The site consists of two units, each with a pressurized water reactor (PWR) nuclear steam supply system and turbine generator furnished by Westinghouse Electric Corporation. Each unit has a gross electrical output of 1029 megawatts electric (MWe). Unit 1 achieved commercial operation on June 6, 1978 and Unit 2 on December 14, 1980. An independent spent fuel storage facility was licensed for dry cask storage of spent fuel in 1998. The United States Nuclear Regulatory Commission (USNRC) regulations require that nuclear power plants be designed, constructed, and operated to keep levels of radioactive material in effluents to unrestricted areas as low as reasonably achievable (ALARA). To ensure these criteria are met, the operating license for North Anna Power Station includes Technical Specifications which address the release of radioactive effluents. In-plant monitoring is used to ensure release limits are not exceeded. As a precaution against unexpected or undefined environmental processes which might allow undue accumulation of radioactivity in the environment, a program for monitoring the plant environs is also included in the North Anna Power Station Offsite Dose Calculation Manual (ODCM). North Anna Power Station is responsible for collecting the various indicator and control environmental samples. Radiation Detection Company is utilized for processing the TLDs. Teledyne Brown Engineering Environmental Services (TBE) is utilized for sample analyses. The results of the analyses are used to determine if changes in radioactivity levels may be attributable to station operations. Measured values are compared with control levels, which vary with time due to external events, such as cosmic ray bombardment, nuclear weapons test fallout and seasonal variations of naturally occurring radioisotopes. Data collected prior to station operation is used to indicate the degree of natural variation to be expected. The pre-operational data is compared with data collected during the operational phase to assist in evaluating any radiological impact of station operation. Occasionally samples of environmental media show the presence of man-made isotopes. As a method of referencing the measured radionuclide concentrations in the sample media to a dose consequence to man, the data is compared to the reporting level concentrations listed in North Anna's ODCM. These concentrations are based upon the annual dose commitment recommended by 10CFR50, Appendix I, to meet the criterion of "As Low As Is Reasonably Achievable". This report documents the results of the Radiological Environmental Monitoring Program for 2024 and satisfies the following objectives of the program: To provide measurements of radiation and of radioactive materials in those exposure pathways and for those radionuclides that lead to the highest potential radiation exposure of the maximum exposed member of the public resulting from station operations. To supplement the radiological effluent monitoring program by verifying that radioactive effluents are within allowable limits. To identify changes in radioactivity in the environment. 6

To verify that station operations have no detrimental effect on the health and safety of the public. 2.2 Sampling and Analysis Program Table 2-1 summarizes the 2024 sampling program for North Anna Power Station. All samples listed in Table 2-1 are taken at indicator locations except those labeled "control." The North Anna Radiological Monitoring Locations maps denote sample locations for North Anna Power Station. The locations are color coded to designate sample types. Table 2-2 summarizes the analysis program conducted by TBE for North Anna Power Station during the year 2024. 7

TABLE 2-1 North Anna Power Station - 2024 RADIOLOGICAL SAMPLING STATION DISTANCE AND DIRECTION FROM UNIT NO. 1 Collection Sam~le Media Location Station Distance Direction Degrees FreguencI Remarks Environmental NAPS Sewage Treatment Plant 01 0.20 NE 42° Quarterly & Annually Dosimetry (TLD) Fredericks Hall 02 5.30 SSW 203° Quarterly & Annually Mineral, Va 03 7.10 WSW 243° Quarterly & Annually Wares Crossroads 04 5.10 WNW 287° Quarterly & Annually Route 752 05 4.20 NNE 20° Quarterly & Annually Sturgeon's Creek Marina 05A 2.04 N 110 Quarterly & Annually Levy, VA 06 4.70 ESE 115° Quarterly & Annually Bumpass, VA 07 7.30 SSE 167° Quarterly & Annually End of Route 685 21 1.00 WNW 301 ° Quarterly & Annually Route 700 22 1.00 WSW 242° Quarterly & Annually "Aspen Hills" 23 0.93 SSE 158° Quarterly & Annually Orange, VA 24 22.00 NW 325° Quarterly & Annually Control Bearing Cooling Tower N-1/33 0.06 N 100 Quarterly Sturgeon's Creek Marina N-2/34 2.04 N 11 ° Quarterly Parking Lot "C" (on-site) NNE-3/35 0.24 NNE 32° Quarterly Good Hope Church NNE-4/36 3.77 NNE 25° Quarterly Parking Lot "B" NE-5/37 0.20 NE 42° Quarterly Lake Anna Marina (Bogg's Dr) NE-6/38 1.46 NE 34° Quarterly Weather Tower Fence ENE-7/39 0.36 ENE 74° Quarterly Route 689 ENE-8/40 2.43 ENE 65° Quarterly Near Training Facility E-9/41 0.30 E 91° Quarterly "Morning Glory Hill" E-10/42 2.85 E 93° Quarterly Island Dike ESE-11/43 0.12 ESE 103° Quarterly Route 622 ESE-12/44 4.70 ESE 115° Quarterly DVP Biology Lab SE-13/45 0.64 SE 1380 Quarterly Route 701 (Dam Entrance) SE-14/46 5.88 SE 137° Quarterly "Aspen Hills" SSE-15/47 0.93 SSE 158° Quarterly Elk Creek SSE-16/48 2.33 SSE 165° Quarterly NAPS Access Rd. S-17/49 0.36 s 173° Quarterly 8

TABLE 2-1 North Anna Power Station - 2024 RADIOLOGICAL SAMPLING STATION DISTANCE AND DIRECTION FROM UNIT NO. 1 Collection Sam~le Media Location Station Distance Direction Degrees Freguency Remarks Environmental Elk Creek Church S-18/50 1.55 s 178° Quarterly Thermoluminescent NAPS Access Rd. SSW-19/51 0.24 SSW 197° Quarterly Dosimetry (TLD) Route 618 SSW-20/52 5.30 SSW 205° Quarterly 500kv Tower SW-21/53 0.60 SW 218° Quarterly Route 700 SW-22/54 3.96 SW 232° Quarterly NAPS SE Switchyard WSW-23/55 0.38 WSW 237° Quarterly Route 700 (Exclusion Boundary) WSW-24/56 1.00 WSW 242° Quarterly South Gate Switchyard W-25/57 0.32 w 279° Quarterly Route 685 W-26/58 1.55 w 274° Quarterly End of Route 685 WNW-27/59 1.00 WNW 301° Quarterly Route 685 WNW-28/60 1.40 WNW 303° Quarterly North Gate - Laydown Area NW-29/61 0.52 NW 321 ° Quarterly Lake Anna Campground NW-30/62 2.54 NW 319° Quarterly

1. 1/#2 Intake NNW-31/63 0.07 NNW 349° Quarterly Route 208 NNW-32/64 2.21 NNW 344° Quarterly Bumpass Post Office C-1/2 7.30 SSE 167° Quarterly Orange, VA C-3/4 22.00 NW 325° Quarterly Control Mineral, VA C-5/6 7.10 WSW 243° Quarterly Louisa, VA C-7/8 11.54 WSW 257° Quarterly Control Airborne Particulate NAPS Sewage Treatment Plant 01 0.20 NE 42° Weekly and Radioiodine Biology Lab 0lA 0.64 SE 1380 Weekly Fredericks Hall 02 5.30 SSW 203° Weekly Mineral, VA 03 7.10 WSW 243° Weekly Wares Crossroads 04 5.10 WNW 287° Weekly Route 752 05 4.20 NNE 20° Weekly Sturgeon's Creek Marina 05A 2.04 N

110 Weekly Levy, VA 06 4.70 ESE 115° Weekly Bumpass, VA 07 7.30 SSE 167° Weekly 9

TABLE 2-1 North Anna Power Station-2024 RADIOLOGICAL SAMPLING STATION DISTANCE AND DIRECTION FROM UNIT NO. 1 Collection Sam~le Media Location Station Distance Direction Degrees Freguency Remarks Airborne Particulate End of Route 685 21 1.00 WNW 301 ° Weekly and Radioiodine Route 700 22 1.00 WSW 242° Weekly "Aspen Hills" 23 0.93 SSE 158° Weekly Orange, VA 24 22.00 NW 325° Weekly Control Surface Water Waste Heat Treatment Facility 08 3.37 SSE 148° Monthly (Second Cooling Lagoon) Lake Anna (upstream) 09A 12.90 WNW 295° Monthly Control (Route 669 Bridge) River Water Nmih Anna River (downstream) 11 5.80 SE 128° Monthly Ground Water Biology Lab 0lA 0.64 SE 138° Quarterly (Well Water) Precipitation Biology Lab 0lA 0.64 SE 1380 Monthly Aquatic Sediment Waste Heat Treatment Facility 08 3.37 SSE 148° Semi-Annually (Second Cooling Lagoon) Lake Anna (upstream) 09A 12.90 WNW 295° Semi-Annually Control (Route 669 Bridge) North Anna River (downstream) 11 5.80 SE 128° Semi-Annually Shoreline Soil Waste Heat Treatment Facility 08 3.37 SSE 148° Semi-Annually (Second Cooling Lagoon) Soil NAPS Sewage Treatment Plant 01 0.20 NE 42° Once/3 years Fredericks Hall 02 5.30 SSW 203° Once/3 years Mineral, VA 03 7.10 WSW 243° Once/3 years Wares Crossroads 04 5.10 WNW 287° Once/3 years Route 752 05 4.20 NNE 20° Once/3 years Sturgeon's Creek Marina 05A 2.04 N 11 ° Once/3 years Levy, VA 06 4.70 ESE 115° Once/3 years 10

Sam.[!le Media Soil Fish Food Products (Vegetation) TABLE 2-1 North Anna Power Station-2024 RADIOLOGICAL SAMPLING STATION DISTANCE AND DIRECTION FROM UNIT NO. 1 Collection Location Station Distance Direction Degrees Freguenc~ Bumpass, VA 07 7.30 SSE 167° Once/3 years End of Route 685 21 1.00 WNW 301 ° Once/3 years Route 700 (Exclusion Boundary) 22 1.00 WSW 242° Once/3 years 11 Aspen Hills 11 23 0.93 SSE 158° Once/3 years Orange, VA 24 22.00 NW 325° Once/3 years Waste Heat Treatment Facility 08 3.37 SSE 148° Semi-Annually (Second Cooling Lagoon) Lake Orange 25 16.5 NW 312° Semi-Annually Stagecoach Road 14B 1.22 NNE 40° Monthly if available or at harvest Route 614 15 1.37 SE 133° Monthly if available or at harvest Route 629/522 16 12.60 NW 314° Monthly if available or at harvest Aspen Hills 23 0.93 SSE 158° Monthly if available or at harvest "Historic Lane" 26 1.15 s 172 ° Monthly if available or at harvest 11 Remarks Control Control Control

SAMPLE MEDIA Thermoluminescent Dosimetry (TLD) (84 TLDs) (12 TLDs) Airborne Radioiodine Airborne Particulate Surface Water River Water TABLE 2-2 North Anna Power Station SAMPLE ANALYSIS PROGRAM FREQUENCY ANALYSIS LLD Quarterly Gamma Dose 2mR+/-2mR Annually Gamma Dose 2mR+/-2mR Weekly I-131 0.07 Weekly Gross Beta 0.01 Quarterly (a) Gamma Isotopic Cs-134 0.05 Cs-137 0.06 2nd Quarter Sr-89 (b) Composite Sr-90 (b) Monthly I-131 l(c) Gamma Isotopic Mn-54 15 Fe-59 30 Co-58 15 Co-60 15 Zn-65 30 Zr-95 30 Nb-95 15 Cs-134 15 Cs-137 18 Ba-140 60 La-140 15 Quarterly(a) Tritium (H-3) 2000 2nd Quarter Sr-89 (b) Composite Sr-90 (b) Monthly I-131 l(c) Gamma Isotopic Mn-54 15 Fe-59 30 Co-58 15 Co-60 15 Zn-65 30 Zr-95 30 Nb-95 15 Cs-134 15 Cs-137 18 Ba-140 60 La-140 15 REPQRT llNITS mR/std. Month mR/std. Month pCi/m3 pCi/m3 pCi/m3 pCi/m3 pCi/L pCi/L pCi/L pCi/L pCi/L pCi/L

• LLDs indicate those levels to which environmental samples are required to be analyzed. Actual analysis of samples may be lower than the listed values.

(a) Quarterly composite of each location's samples are used for the required analysis (b) There are no required LLDs for Sr-89/90 ( c) LLD for non-drinking water is 10 pCi/liter ( d) LLD applied are those for water samples. However, since this is a semi-annual composite no LLD is applied for these nuclides due to their short half-lives. 12

SAMPLE MEDIA River Water Ground Water (Well Water) Aquatic Sediment Precipitation Shoreline Soil TABLE 2-2 North Anna Power Station SAMPLE ANALYSIS PROGRAM FREQUENCY ANALYSIS LLD Quarterly( a) Tritium (H-3) 2000 2nd Quarter Sr-89 (b) Composite Sr-90 (b) Quarterly Gamma Isotopic Mn-54 15 Fe-59 30 Co-58 15 Co-60 15 Zn-65 30 Zr-95 30 Nb-95 15 I-131 l0(c) Cs-134 15 Cs-137 18 Ba-140 60 La-140 15 Quarterly( a) Tritium (H-3) 2000 2nd Quarter Sr-89 (b) Sr-90 (b) Semi-Annually Gamma Isotopic Cs-134 150 Cs-137 180 Annually Sr-89 (b) Sr-90 (b) Monthly Gross Beta 4 Semi-Annual Gamma Isotopic Composite Mn-54 15 Fe-59 30 Co-58 15 Co-60 15 Zn-65 30 Zr-95 30 Nb-95 15 I-131 (d) Cs-134 15 Cs-137 18 Ba-140 (d) La-140 (d) Semi-Annually Gamma Isotopic Cs-134 150 Cs-137 180 Annually Sr-89 (b) Sr-90 (b) REPQRT llNITS pCi/L pCi/L pCi/L pCi/L pCi/L pCi/kg (dry) pCi/kg (dry) pCi/L pCi/L pCi/kg (dry) pCi/kg (dry)

• LLDs indicate those levels to which environmental samples are required to be analyzed. Actual analysis of samples may be lower than the listed values.

(a) Quarterly composite of each location's samples are used for the required analysis (b) There are no required LLDs for Sr-89/90 ( c) LLD for non-drinking water is 10 pCi/liter ( d) LLD applied are those for water samples. However, since this is a semi-annual composite no LLD is applied for these nuclides due to their short half-lives. 13

Legend For The North Anna Power Station Environmental Monitoring Stations Overview Maps Map Environmental Station Designation Identification 1 (a) 01,NE-5/37 IA 0IA,SE-13/45 2 (a) 02,SSW-20/52 3 (a) 03,C-5/6 4 (a) 04 5 (a) 05 5A (a) 05A,N-2/34 6 (a) 06,ESE-12/44 7 (a) 07, C-1/2 8 08-Water, Fish, Sediment, Shoreline Soil 9A 09 A-Water sample, Sediment 11 I I-River Water, Sediment 14B 14 B-V egetation 15 15-Vegetation 16 16-V egetation 21 (a) 21,WNW-27/59 22 (a) 22,WSW-24/56 23 (a) 23-SSE-15/47,Vegetation 24 (a)(b) 24,C-3/4 25 (c) 25-Fish 26 26-Vegetation (a) Indicates air sample station, annual and quarterly TLD, Triennial soil. (b) In Orange ( c) In Lake Orange 15 Map Environmental Station Designation Identification 7/8 C-7/8 1/33 N-1/33 31/63 NNW-31/63 29/61 NW-29/61 3/35 NNE-3/35 7/39 ENE-7/39 9/41 E-9/41 11/43 ESE-11/43 17/49 S-17/49 19/51 SSW-19/51 21/53 SW-21/53 23/55 WSW-23/55 16/48 SSE-16/48 14/46 SE-14/46 22/54 SW-22/54 26/58 W-26/58 28/60 WNW-28/60 32/64 NNW-32/64 8/40 ENE-8/40 4/36 NNE-4/36 10/42 E-10/42

Legend fixed Environmen.tal Monitoring Sla1io n.o Loca1ions Scare - 3f8 inch = 235 ft.. Figure 1. North Anna Site Radiological Monitoring Locations SSW 16

MAs,N I J:_~Rf ,/' ~=_;..,-.;:.:--- \\ n ~ ~.., ~~ ~ 1-NNE ~ 0-AA ... ~ vu'J-r jf';:- (io~~ - - ~.--_,,.,,. * ~-----** ~~~~- ~~ y -,.~:2.----...,,-,, / ATEWOOD. -~-..,~~- -- G~v -;tttt!"

• ~-{J::;~** 1

~~~~~ .Uk ,,,,. r~ ("~ 17 ~~ ~1 ~ ~ TSYLVANii "- 't North Anna Environmental Map !Fixed Environmental Samplling Location 1 TLO Sampling Garden ( IAesidents , Meat Animals Origirnal 9 1991 by ADC of Alexandria.. Inc., 6440 Gener:al Gre,en Wo.y. Af.ax:mclrfa. VA 22312. USED WITH PERt.llSSJON. INo othe-r reproduction m o.v be m o.de Ylilhoul die wrJtten perrni33ion of ADC.. ~- - ~ ENI ~ MARYE ~

?_.

E. * /AAA\\ _.j~f:/ OB32soH

// .7',, llORE tOSSI -.s- ,-~. /2 ~ JO (,.J. /y ~} ,,,1\\ Nortn 1-\\nna CHVI ronrn l 'vl H, Fixed Environmental Sampling Location TLD Sampling Garden IResidents Meat Animalls Original © 1 gg1 oY ADC 01 Alexandria, Inc., 6440 General Green way, Alexandria, VA 22312. USED WilT:H PERMISSION. NO otner reproaucoon may oe made wnnoul the written permission 01 ADC. ~1 ~2~ I ~ t\\, /;/ ~\\ V A -*MA~* ~~ -~~o~ MINE I ii' .i 18 ~

• • 1 *

\\ l /-:'!, 9 MO,NT

• ../

REE MILE nuu ..... A-N[R s*,~.,F-"'c...-:'-"17.,.= C,83283G

L -~.*::r I~ I, rNw, -~ ----<' ,<?' MONROVtlA~ (~*-

• (:'~

./ ~ N ~~ -~ -- ' '-c 1, !J ~:::::=-;r /'. ~ 4::, ~;- ~ ~ -=*"* --=***'.,.;

65.

4:

• H--

VAWTl.,.-...... : '* * / .4 I COR:NER *:::t,;:;.

b.

-~.... I.II .::~ ~ / ' J I North Anna Environmental !Map Fixed Environmental Sampling llocalion TLJD -Samplmng Garden (, Residents Meat Animals 0 11ginal t> 199 11 b;, ADC oU\\ll&ll.Bffllllria, me.. 64,ilO lleflertill Gree~ lll/ety, Ale'.tatrldr,la, '!IA 223112~ USED Wll1f-'I PE:lllMISSitON.. No 01I1e! N!i,jX'QdUCttl~ ma.y be-rnadl!! w ilt.lout. tthe M1t1em pennl!l81cl'l -ol AOC. ,f '.~ ~ANTON ~ W _,v..'t p l, r.... ~... ~:; I 19 --~.....-*""WIIJ ~ NNW ~NMb~, .Q"~b-=~Qc ~~~ JON~ iJ~if/~. ?\\M°'"IEllS uaes / ~c"oss N' n!tttJ l(~.a ~ 'i ~ ~ jl\\ i .f

1 CM201G

IICKHAI ORNER ~ ..#} 1:-1 E ~,__, ~ -15 20 ~

• soe

--~~:: .. ~* ~ _='_*=::.-._ ,I

• ~

~.. Q..b. ~-

---

~--~~~

North Anna Environmentalll Map Fixed Environmemal Sampling Location TLD Sampling 1Garden C Resid,ents Meat Animars Ollgn:rl,fl 11Q.Q1 t:,/ ADC Of Ale.xiilTlarla, IILC.* 1644{) Gene1:al Gleen 1,vay. AleXaoorla, VA 22312.. USED YIITIH PERM1SSIO'l'1L N'O o1hel 1rep1001£1Jon rooy'be made \\t1hrut me 11','lltlefl [Pelrm55100 OT AIDC. CB3282G-

3. ANALYTICAL RESULTS 3.1 Summary of Results In accordance with the North Anna Offsite Dose Calculation Manual (ODCM), a summary table of the analytical results has been prepared and is presented in Table 3-1. This data is presented in accordance with the format of the USNRC Branch Technical Position, "Acceptable Radiological Environmental Monitoring Program", Rev. 1, November 1979. The LLD listed value is taken from the ODCM. For radioanalytic analyses, the values listed in the columns indicated as "Mean/Range" include any results above the Minimum Detectable Concentration, MDC. Results are considered true positives when the measured value exceeds both the MDC and the 2E error. For TLDs the mean and range include all values.

A more detailed analysis of the data is given in Section 4 where a discussion of the variations in the data explains many aspects that are not evident in the Summary Table because of the basic limitation of data summaries. 21

RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Page 1 of 6 RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

NORTH ANNA NUCLEAR POWER STATION, LOUISA COUNTY, VIRGINIA 2024 Docket No. 50-338/339 2023 Medium or Pathway Sampled (Units) Direct Radiation (mR.std. Month) (Sector TLDs) Analysis Type Gamma Dose

• • C3/4, -718 used for control locations Direct Radiation Gamma (mR.std. Month)

Dose (Pre-operational TLDs) ""' C3/4, -718 used for control locations Direct Radiation Gamma (mR.std. Month) Dose (Emergency Sector TLDs)

• • C3/4, -718 used for control locations Direct Radiation Gamma (mR.std. Month)

Dose (Environmental TLDs) Direct Radiation Gamma (mR.std. Month) Dose (Annual TLDs) Air Particulate GR-B (10e-3 pCifm3) GAMMA BE-7 Cs-134 Cs-137 Sr-89 Sr-90 Air Iodine 1-131 (10e*3 pCifms) sou-GAMMA (pCilkg dry wt.) K-40 CS-134 CS-137 Ra-226

• LLD identifed in OOCM
  • C-3/4, 7 /S used as control locations Total LLD" Number 253 2

32 2 39 2 48 2 12 2 689 0.o1 52 52 NA 52 0.05 52 0.06 13 0.01 13 0.o1 689 0.07 0 0 0 150 0 180 0 Indicator Locations Mean (Range) 5.3 (253/253) (1.4-10.2) 3.5 (16/16) (1.1-5.0) 6.1 (39/39) (3.1-9.1) 4.4 (44/44) (1.8-7.8) 3.9 (11/11) (2.7-5.7) 17.0 (636/636) (4.46-40.3) 115.4 (48/48) (67.2-185.4) (0/48) (0/48) (0/48) (0/48) (01636) NIA NIA NIA NIA Indicator Location with Highest Mean Numberl Distance Direction 29/61 0.52 M1. NW C-1/2 7.30 ML SSE EPSR 0.2Mi. 05/06 NNW STA-01 0.20Mi. NE STA-23 0.93Mi. SSE 05A 2.04Mi. N 03 7.10Mi. WSW NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA N/A NIA NIA NIA NIA NIA NIA 22 I Mean (Range) 9.2 (8/8) (7.8-10.2) 4.0 (8i8) (2.4-5.0) 7.9 (8/8) (6.4-9.1) 6.5 (4/4) (5.8-7.8) 5.7 (1/1) (5.7) 18.6 (53/53) (6.73-40.3) 138.9 (4/4) (99.5-185.4) NIA NIA NIA NIA NIA NIA NIA NIA NIA Control Locations Mean (Range) 4.1 (16/16) (2.4-5.0) 4.1 (16/16) (2.4-5.0) 4.1 (16/16) (2.4-5.0) 4.0 (4/4) (3.1-4.5) 3.3 (1/1) (3.3) 17.0 (53/53) (6.82-29.8) 114.4 (4/4) (102.7-126.3) (0/4) (0/4) (0/4) (0/4) (0/53) NIA NIA NIA NIA Non-Routine Reported Measurement 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Page 2 of 6 Medium or Pathway Sampled (Units) Soll-.. (cont'd) (pCilkg dry wt.) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

NORTH ANNA NUCLEAR POWER STATION, LOUISA COUNTY, VIRGINIA 2024 Docket No. 50-338/339 2023 Indicator Indicator Analysis Total LLD* Locations Location with Highest Mean Type Number Mean Numberl Distance I Mean (Range) Direction (Range) Th-228 0 NIA NIA NIA NIA Th-232 0 NIA NIA NIA NIA Sr-89 0 NIA NIA NIA NIA Sr-90 0 NIA NIA NIA NIA

• • • Soll samples are obtained triennially.

Precipitation GR-B 12 4 3.2 (9112) 01A 0.64Mi. 3.2 (9/12) (pCilliter) (2.1-6.8) SE (2.1-6.8) H-3 12 2000 (0/12) NIA NIA NIA GAMMA 2 Be-7 2 (0/2) NIA NIA NIA Mn-54 2 15 (0/2) NIA NIA NIA Fe-59 2 30 (0/2) NIA NIA NIA Co-58 2 15 (0/2) NIA NIA NIA Co-60 2 15 (0/2) NIA NIA NIA Zn-65 2 30 (0/2) NIA NIA NIA Zr-95 2 30 (0/2) NIA NIA NIA Nb-95 2 15 (0/2) NIA NIA NIA Cs-134 2 15 (0/2) NIA NIA NIA Cs-137 2 18 (0/2) NIA NIA NIA Ba-140 2 60 (0/2) NIA NIA NIA La-140 2 15 (0/2) NIA NIA NIA 1-131 2 10 (0/2) NIA NIA NIA 23 Control Locations Mean (Range) NIA NIA NIA NIA NA NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA NIA Non-Routine Reported Measurement 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Page 3 of 6 RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

NORTH ANNA NUCLEAR POWER STATION, LOUISA COUNTY, VIRGINIA 2024 Docket No. 50-338/339 2023 Medium or Indicator Indicator Control Pathway Analysis Total LLD* Locations Location with Highest Mean Locations Non-Routine Reported Sampled Type Number Mean Number I Distance I Mean Mean Measurement (Units) (Range) Direction (Range) (Range) Precipitation (cont'd) Th-228 2 4.855 (1/2) 01A 0.64Mi. 4.855 (1/2) NIA 0 (pCiJ/iter) (4.855) SE (4.855) Fruits & Vegetables GAMMA 35 (pCilkg wet wt) Be-7 35 1245 (25/28) 14B 1.22 Ml. 1609 (6/7) 1978 (6/7) 0 (379.5-4105) NNE (511-4105) (956.2-3163) K-40 35 4016 (28/28) 14B 1.22 Mi. 5129 (7/7) 4655 (7/7) 0 (1727-6665) NNE (3050-6596) (297 4-6625) 1-131 35 60 (0/28) NIA NIA NIA (0/7) 0 Cs-134 35 60 {0/28) NIA NIA NIA (0/7) 0 Cs-137 35 80 (0/28) NIA NIA NIA (0/7) 0 Ra-226 35 918.1 (1/28) 23 0.93Mi. 918.1 (1/7) <LLD 0 (918.1) SSE (918.1) Th-228 35 123.8 (5/28) 23 0.93Mi. 152.9 (3/7) <LLD 0 (63.3-229.4) SSE (93.4-229.4) Th-232 35 463 (2/28) 23 0.93Mi. 463 (217) <LLD 0 (335.6-590.4) SSE {335.6-590.4) Well Water H-3 4 2000 (0/4) NIA NIA NIA NIA 0 (pCilliter) GAMMA 4 Mn-54 4 15 (0/4) N/A NIA NIA NIA 0 Fe-59 4 30 (0/4) NIA NIA NIA NIA 0 Co-58 4 15 (0/4) NIA NIA NIA NIA 0 Co-60 4 15 (0/4) NIA NIA NIA NIA 0 Zl1-65 4 30 (0/4) NIA NIA NIA NIA 0 Zr-95 4 30 (0/4) NIA NIA NIA NIA 0 Nb-95 4 15 (0/4) NIA NIA NIA NIA 0 1-131 4 10 (0/4) NIA NIA NIA NIA 0 Cs-134 4 15 (0/4) NIA NIA NIA NIA 0 Cs-137 4 18 (0/4) NIA NIA NIA NIA 0 24

RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Page 4 of 6 Medium or Pathway Sampled (Units) Well Water (cont'd) (pCi/liter) River Water (pCi/liter) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

NORTH ANNA NUCLEAR POWER STATION, LOUISA COUNTY, VIRGINIA 2024 Docket No. 50-338/339 2023 Indicator Indicator Analysis Total LLD* Locations Location with Highest Mean Type Number Mean Numberl Distance I Mean (Range) Direction (Range) Ba-140 4 60 (0/4) NIA NIA NIA La-140 4 15 (0/4) NIA NIA NIA Sr-89 (0/1) NIA NIA NIA Sr-90 (0/1) NIA NIA NIA H..3 4 2000 4023 (4/4) 11 5.80Mi. 4023 (4/4) (1850-6740) SE (1850-6740) GAMMA 12 Mn-54 12 15 (0/12) NIA NIA NIA Fe-59 12 30 (0/12) NIA NIA NIA Co-58 12 15 (0/12) NIA NIA NIA Co-60 12 15 (0/12) NIA NIA NIA Zn-65 12 30 (0/12) NIA NIA NIA Zr-95 12 30 (0/12) NIA NIA NIA Nb-95 12 15 (0/12) NIA NIA NIA 1-131 12 (0/12) NIA NIA NIA Cs-134 12 15 (0/12) NIA NIA NIA Cs-137 12 18 (0/12) NIA NIA NIA Ba-140 12 60 (0/12) NIA NIA NIA La-140 12 15 (0/12) NIA NIA NIA Sr-89 (0/1) NIA NIA NIA Sr-90 (0/1) NIA NIA NIA 25 Control Non-Routine Locations Reported Mean Measurement (Range) NIA 0 N/A 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0 NIA 0

RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Page 5 of 6 Medium or Pathway Sampled (Units} Surface Water (pCl/1iter) Sediment Slit (pCl/kg dry wt.) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

NORTH ANNA NUCLEAR POWER STATION, LOUISA COUNTY, VIRGINIA 2024 Docket No. 50-338/339 2023 Indicator Indicator Analysis Total LLD* Locations Location with Highest Mean Type Number Mean Numberl Distance I Mean (Range) Direction (Range) H-3 8 2000 4713 (4/4) 08 3.37Mi. 4713 (4/4) (2900-6080) SSE (2900-6080) GAMMA 24 Mn-54 24 15 (0/12) NIA NIA NIA Fe-59 24 30 (0/12) NIA NIA NIA Co-58 24 15 (0/12) NIA NIA NIA Co-60 24 15 (0/12) NIA NIA NIA Zn-65 24 30 (0/12) NIA NIA NIA Zr-95 24 30 (0/12) NIA NIA NIA Nb-95 24 30 (0/12) NIA NIA NIA 1-131 24 (0/12) NIA NIA NIA Cs-134 24 15 (0/12) NIA NIA NIA Cs-137 24 18 (0/12) NIA NIA NIA Ba-140 24 60 (0/12) NIA NIA NIA La-140 24 15 (0/12) N/A NIA NIA Sr-89 2 (0/1) NIA NIA NIA Sr-90 2 (0/1) NIA NIA NIA GAMMA 6 K-40 6 10962 (4/4) 11 5.80Mi. 20475 (2/2) (1288-23390) SE (17560-23390) Cs-134 6 150 (0/4) NIA NIA NIA Cs-137 6 180 (0/4) NIA NIA NIA Ra-226 6 2198 (1/4) 11 5.80Mi. 2198 (1/2) (2198) SE (2198) 26 Control Locations Mean (Range) (0/4) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/12) (0/1) (0/1) 10820 (2/2) (10670-10970) (0/2) (0/2) (0/2) Non-Routine Reported Measurement 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Page 6 of 6 Medium or Pathway Sampled (Units) Sediment Slit (cont'd) (pCilkg dry wt.) Shoreline Soll (pCilkg dry wt.) Fish-other (pCilkg wet wt.) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

NORTH ANNA NUCLEAR POWER STATION, LOUISA COUNTY, VIRGINIA 2024 Docket No. 50-338/339 2023 Indicator Indicator Analysis Total LLD* Locations Location with Highest Mean Type Number Mean Numberl Distance I Mean {Range) Direction (Range) Th-228 6 898.5 (3/4) 11 5.80Mi. 1297 (2/2) (101.6-1440} SE (1154-1440) Th-232 6 1138 (2/4) 11 5.80Mi. 1138 (2/2) (989.4-1287) SE (989.4-1287) Sr-89 3 (0/2) NIA NIA NIA (Annually) Sr-90 3 (0/2) NIA NIA NIA (Annually) GAMMA 2 K-40 2 1417 (2/2) 08 3.37Mi. 1417 (2/2) {857.5-1976} SSE (857.5-1976) Cs-134 2 150 (0/2) N/A NIA NIA Cs-137 2 180 (0/2) NIA NIA N/A Ra-226 2 (0/2) N/A NIA NIA Th-228 2 124.1 (1/2) 08 3.37Mi. 124.1 (1/2) (124.1) SSE (124.1) Th-232 2 (0/2) NIA NIA NIA Sr-89 (0/1) NIA NIA NIA (Annually) Sr-90 (0/1) NIA NIA NIA (Annually) GAMMA 8 K-40 8 2094 (4/4) 08 3.37Mi. 2094 (4/4) (1369-2959) SSE (1369-2959) Mn-54 8 130 (0/4) NIA NIA NIA Fe-59 8 260 (0/4) NIA NIA NIA Co-58 8 130 (0/4) NIA NIA NIA Co-60 8 130 (0/4) NIA NIA NIA Zn-65 8 260 (0/4) NIA NIA NIA Cs-134 8 130 {0/4) NIA NIA NIA Cs-137 8 150 (0/4) NIA NIA N/A 27 Control Locations Mean (Range) 209.5(2/2) (127.3-291.7) (0/2) (0/1) (0/1) NIA NIA NIA NIA NIA NIA NIA NIA 2083(4/4) (1906-2401) (0/4) (0/4) (0/4) (0/4) (0/4) (0/4) (0/4) Non-Routine Reported Measurement 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

3.2 Analytical Results of 2024 REMP Samples Radiological analyses of environmental media characteristically approach and frequently fall below the detection limits of state-of-the-art measurement methods. The data reported in the following tables are strictly counting statistics. The reported error is two times the standard deviation (2cr) of the net activity. Unless otherwise noted, the overall error ( counting, sample size, chemistry, errors, etc.) is estimated to be 2 to 5 times that listed. Results are considered true positives when the measured value exceeds both the MDC and the 2E error. Because of counting statistics, negative values, zeros and numbers below the Minimum Detectable Level (MDL) are statistically valid pieces of data1. For clarity of this report only detectable results are presented. TBE's analytical methods meet the Lower Limit of Detection (LLD) requirements given in Table 2 of the USNRC Branch Technical Position, "An Acceptable Radiological Environmental Monitoring Program", (November 1979, Revision 1) and the North AnnaODCM. Data are given according to sample type as indicated below.

1.

Gamma Exposure Rate

2.

Air Particulates, Gross Beta Radioactivity

3.

Air Particulates, Weekly I-131

4.

Air Particulates, Quantitative Gamma Spectra

5.

Air Particulate Strontium

6.

Soil

7.

Precipitation

8.

Cow Milk

9.

Food Products and Vegetation

10.

Well Water

11.

River Water

12.

Surface Water

13.

Bottom Sediment/Silt

14.

Shoreline Soil

15.

Fish 1 Analytical results are handled as recommended by HASL ("Reporting of Analytical Results from HASL, "letter by Leo B. Higginbotham) and NUREG/CR-4007 (Sept. 1984). 28

TABLE 3-2 QUARTERLY GAMMA EXPOSURE RA TE (mR/Std_ Month)+/- 2 Sigma First Quarter Second Quarter Third Quarter Fourth Quarter 1/212024-41212024-71212024-10/212024-Station 4/2/2024 71212024 10/212024 1/8/2025 5.8 6.2 N-33 4.8 7_0 5.5 6.2 N-2 2.1 4.3 3.5 4.0 3.6 (+/-) 1.9 N-34 2.4 3.7 4.1 5.0 NNE-3 5.8 8.0 7.4 9.3 7.4 (+/-) 2.4 NNE-35 6.1 7.7 6.8 8.4 NNE-4 3.4 5.7 5.8 5.9 5.3 (+/-) 2.2 NNE-.'36 3.8 5.7 5.5 6.5 NE..S 4.1 6.3 6.4 5.9 5.8 1.9 NE--37 5.1 5.0 6.8 6.5 NE.S 3.1 4] 4.5 5.3 4.5 1.9 NE-38 3.1 5.0 4-8 5.6 ENE-7 5.1 6.0 3.5 7.4 6.0 (+/-) 2.9 ENE--39 5.1 7.3 6.4 7.4 ENE-8 2.1 3.0 6.1 3.7 3.4 2.7 ENE-40 1.8 3.01 3.5 4.0 E-9 4.4 6.3 6.4 7.1 6.2 (+/-) 2. 0 E-41 5.1 6.3 6.1 7.4 E-10 3.4 5.3 5.5 5.9 5.1 2.1 E-42 3.4 6.0 5.5 5.9 ESE-11 4.8 5.7 5.8 7.4 5.8 (+/-) 2.0 ESE-43 4.1 6.0 5.8 6.5 ESE-12 3.8 6.0 6.5 5.5 (+/-) 2.3 ESE-44 4.1 6.0 5.8 6.5 SE-13 4.8 5.7 5.1 6.2 5.5 (+/-) 1.3 SE-45 4.4 6.0 5.5 6.2 SE-14 5.8 7.3 7.8 8.4 7.2 (+/-) 2.3 SE-46 5.4 7.7 6.8 8.7 SSE-15 5.4 6.7 5.8 7.1 6.1 (+/-) 2.0 SSE-47 4.1 6.3 6.8 6.8 SSE-16 2.4 4.3 3.8 4.3 4.0 (+/-) 1.5 SSE-48 3.4 4.3 4.1 5.0 S-17 4.8 7.0 5.5 6.5 5.8 1.9 S-49 4.4 6.0 5.1 6.8 "'Average of collocated TLDs """TLD missing 29

First Quarter 1/2/2024-Station 4/2/2024 S-18 2.1 S-50 1.4 SSW-19 6.4 SSW-51 6.4 SSW-20 2.1 SSW-52 2.1 SW-21 3.4 SW-53 3.8 SW-22 3.8 SW-54 4.1 WSW-23 4.1 WSW-55 3.8 WSW-24 4.8 WSW.So 3.1 W-25 6.1 W-57 6.4 W-26 3.1 W-58 2.4 WNW-27 2.8 WNW-59 3.1 WNW-28 2.4 WNW-60 2.8 NW-29 8.4 NW-61 7.8 NW-30 1.4 NW-62 1.8 NNW-31 3.8 NNW-63 4.4 NNW-32 3.1 NNW-64 3.1 "'Average of collocated TLDs - TLD missing Second Quarter 4/2/2024-7/2/2024 3.7 3.3 8.0 7.7 3.3 3.3 5.3 5.3 6.3 6,0 4.7 6.0 8.4 8.0 3.7 4.0 4.3 4.7 4.3 4.7 9.4 9.4 3.3 3.3 9.7 7.7 5.3 5.3 TABLE 3-2 QUARTERLY GAMMA EXPOSURE RATE (mR/Std. Month}+/- 2 Sigma Turd Quarter Fourth Quarter 71212024-10/2/2024-Quarterty Average" 10/2/2024 1/8/2025 (+/-) 2 S.D. 3.1 3.4 3.0 (+/-} 1.6 3.1 3.7 7.8 8.7 7.7 (+/-) 1.8 7.8 9.0 3.8 3.7 3.3 (+/-) 1.9 3.1 5.0 5.5 5.6 5.1 (+/-) 1.9 5.5 6.2 5.8 6.2 5.3 (+/-) 1.9 5.1 5.1 5.5 5.9 5.1 5.6 5.2 (+/-) 1.9 1 6.8 6.5 6.7 {+/-) 2.0 5.5 5.9 3.5 4.3 3.6 (+/-) 1.3 3.5 4.3 4.1 5.0 4.1 (+/-) 1.7 3.8 5.0 4.1 4.3 4.0 (+/-) 1.8 4.5 5.0 9.1 10.2 9.2 (+/-) 1.5 9.7 9.3 "'7r 3.7 2.9 (+/-) 2.2 = 4.0 5.5 6.2 6.3 (+/-) 3.8

7. 1 5.9 4.8 5.3 4.8 (+/-) 2.2 5.1 6.2 Mean 5.3 (+/-) 3.4 30

First Quarter 1/2/2024-Station 4/2/2024 C-1 2.4 C-2 3.4 C-3= 2.4 C-4= 2.8 C-5 2.1 C-6 1.1 e-1= 3.4 C-8:tt 3.8 EPSA 4.8 EPSA-02:tt* 4.1 EPSF-03""':t 3.8 EPSF-04-* 4.1 EPSR 7.1 EPSR-OO""'x 6.4 EPSJ-07*** 3.8 EPSJ-08,1-:tt 3.1 EPSP 7.8 EPSP 7.4

• Average of collocated TLDs
  • Control Location

-Emergency Plan 1LDs. x:tt,t TLD Missing Second Quarter 41212024-7/2/2024 4.3 3.7 4.0 4.3 3.7 3.3 4.7 4.7 6.0 5.7 5.0 8.0 7.7 5.0 6.0 8.0 8.7 TABLE 3-2 QUARfERLY GAMMA EJPOSURE RA TE (rnR/Std. Month)+/- 2 Sigma Third Q.iarter Fourth Quarter 71212024-10/212024-Quarterly Average,\\" 10/2/2024 1/812025 (+/-) 2 S.D. 4.5 5.0 4.0 (+/-) 1.6 4.1 4.3 4.5 4.7 3.9 (+/-) 1.8 3.8 5.0 2.8 4.3 3.0 (+/-) 2.0 3.5 3.4 3.8 4.3 4.3 (+/-) 1.1 4.8 5.0 Indicator Mean 3.5 (+/-) 2.0 Control Mean 4.1 1.5 6.1 6.5 5.7 1.7 5.5 6.2 5.5 5.6 5.0 (+/-) 1.5 5.3 7.8 8.4 7.9 1.6 9.1 8.4 4.5

7. 1 5.1 (+/-) 2.7 5.1 6.5 5.5 6.2 6.9 (+/-) 2.4 5.5 6.5 Mean 6.1 (+/-) 3.0 31

First Quarter 1/212024-Station 4/2/2024 STA-01 6.4 STA-02 1.8 STA-03 2.8 STA-04 2.1 STA-05 3.1 STA-05A 2.4 STA-06 3.8 STA-07 2.8 STA-21 2.8 STA-22 4.4 STA-23 5.1 STA-24W" 3.1

tA\\efage of collocated TLDs tt Control Second Quarter 4/2/2024-7/2/2024 6.0 3.0 3.7 4.3 5.3 4.3 6.0 4.3 4.0 5.3 6.3 4.0 TABLE 3-2 QUARTERLY GAMMA EXPOS URE RA 1E (mRiStd. Month)+/-2 Sigma Third Quarter Fourth Quarter 71212024-10/212024-Quarterly A..erage;t Annual 10/2/2024 1/8/2025

(+/-)2 S.D. 1lD 5.8 7.8 6.5 (+/-} 1.8 5.1 3.1 4.7 3.1 (+ /-) 2.4 3.0 3.1 3.7 3.3 (+/-) 0.9 2.7 3.5 4.0 3.5 (+/-) 2.0 2.9 4.1 5.0 4.4 (+/-) 2.0 4.1 4.5 5.0 4.0 (+/-) 2.2 3.3 5.8 6.2 5.4 (+/-) 2.3 4.8 3.5 4.3 3.7 (+/-) 1.5 3.3 3.8 4.7 (+/-) 1.6 3.3 4.8 5.6 5.0 (+/-) 1.1 4.6 5.8 6.5 5.9 (+/-) 1.3 5.7 4.5 4.3 4.0 12 3.3 Mean Indicator Locations 4.4 (+/-) 2.7 3.9 (+/-) 2.0 32

TABLE 3-3 AIR PARTICULATES GROSS BETA RADIOACTIVITY (1Q*3 pCi/m3) LOCATIONS PERIOD ENDING 01 02 03 04 05 06 07 21 (+/-} (+/-) (+/-) (+/-} (+/-) (+/-) (+/-) (+/-) 01 /02/24 11.00 2.550 11.40 2.560 5.590 2.190 10.80 2.490 11.50 2.540 9.210 2.430 10.60 2.520 11.60 2.570 01/10/24 13.10 2.400 5.550 1.980 9.910 2.270 10.50 2.290 8.510 2.170 12.20 2.370 11.10 2.310 9.300 2.170 01117/24 20.30 3.020 19.60 2.990 24.30 3.190 22.20 3.100 22.50 3.150 19.50 2.970 20.10 3.010 21.10 3.050 01 /23/24 29.60 3.640 21.20 3.220 18.60 3.110 29.80 3.820 27.10 3.720 18.90 3.100 24.40 3.540 24.20 3.440 01/30/24 10.70 2.390 7.120 2.170 8.770 2.260 8.060 2.210 12.20 2.480 9.060 2.290 6.260 2.110 7.260 2.140 02/06/.24 15.90 2.650 13.00 2.480 11.40 2.380 13.50 2.510 11.40 2.390 11.20 2.370 10.20 2.310 13.00 2.480 02/14/24 11.90 2.340 9.500 2.210 11.30 2.310 12.80 2.390 13.60 2.430 13.80 2.440 14.20 2.470 11.50 2.3.20 02/20/24 19.00 3.070 14.70 2.890 18.20 3.090 21.50 3.270 16.80 3.020 20.20 3.200 11.00 2.670 17.40 3.050 02127124 20.90 3.040 18.70 2.880 19.20 2.920 19.80 2.940 19.40 2.930 22.70 3.220 16.40 2.770 18.70 2.890 03/06/24 11.40 2.250 8.450 2.070 8.900 2.100 9.800 2.150 12.10 2.390 11.40 2.250 9.360 2.130 11.50 2.250 03/1 9.690 2.650 9,620 2.620 7,890 180 9.910 2.590 9.490 2,620 03/19/24 24.10 3.130 18.20 2.850 18.90 2.890 12.10 2.540 18.70 2.890 19.00 3.030 16.70 2.780 18.60 2.880 03/26/24 12.40 2.720 12.40 2.730 10.90 2.640 14.50 2.840 12.60 2.740 12.80 2.750 11.90 2.750 12.30 2.720 04/02/24 20.10 2.910 15.20 2.640 19.00 2.830 17.10 2.730 16.80 2.720 16.90 2.730 14.60 2.610 17.00 2.720 04/09/24 7.120 2.100 4.460 1.910 8.730 2.230 5.840 2.030 6.980 2.100 8.400 2.190 6.210 2.040 4.950 1.990 04/17/24 18.30 2.550 15.20 2.390 16.60 2.460 15.20 2.390 17.80 5.080 17.40 2.500 17.30 2.500 16.50 2.460 04/23/24 16.80 3.080 9.790 2.670 14.50 2.950 9.560 2.660 16.40 3.070 14.40 2.960 13.70 2.900 14.10 2.930 05/01 /24 18.40 2.600 16.40 2.500 20.40 2.700 15.40 2.450 15.90 2.480 15.10 2.440 15.10 2.430 17.30 2.550 05/08/24 10.20 2.420 8.880 2.350 12.00 2.530 9.890 2.410 8.240 2.310 10.80 2.460 11.50 2.500 10.20 2.430 05/15/24 10.20 2.350 10.80 2.380 13.30 2.530 11.80 2.440 9.920 2.320 12.00 2.450 12.30 2.470 11.70 2.440 05/21/24 7.560 2.470 7.940 2.510 6.48 2.400 6.490 2.400 4.640 2.280 7.890 2.510 7.840 2.490 6.310 2.390 05/28/24 13.40 2.630 11.40 2.530 16.40 2.780 10.10 2.440 13.60 2.660 13.40 2.640 12.00 2.570 12.40 2.550 06/05/24 17.50 2.650 13.70 2.450 16.80 2.620 16.20 2.600 15.10 2.520 15.70 2.550 14.80 2.510 15.80 2.590 06/12/24 15.10 2.650 11.50 2.440 15.30 2.650 13.70 2.560 14.70 2.620 10.50 2.380 11.10 2.410 10..80 2.390 06/19/24 19.30 2.910 18.80 2.890 17.90 2.840 17.90 2.850 18.60 2.890 21.00 3.000 17.90 2.850 16.60 2.780 06/25/24 14.20 2.980 14.90 3.010 16.10 3.080 14.50 2.960 14.90 3.010 14.50 2.990 13.50 2.930 13.50 2.930 33

TABLE 3-3 AIR PARTICULATES GROSS BETA RADIOACTIVITY (10*3 pCi/m3) LOCATIONS PERIOD ENDING 01 02 03 04 05 06 07 21 (+/-) (+/-) (+/-} (+/-) (+/-) (+/-) (+/-) (+/-) 07/02/24 13.40 2.600 13.90 2.630 16.10 2.700 16.90 2.780 13.50 2.600 12.90 2.560 12.80 2.560 13.00 2.570 07/09/24 16.20 2.820 17.50 2.890 19.10 3.010 14.10 2.740 16.70 2.850 13.30 2.650 16.10 2.810 18.30 2.920 07117/24 18.50 2.660 20.10 2.860 19.00 2.700 18.50 2.670 18.30 2.660 14.80 2.490 17.40 2.620 15.50 2.520 07/23/24 17.00 3.230 11.80 2.950 18.70 3.310 14.30 3.090 18.50 3.460 14.80 3.260 15.70 3.150 10.70 2.880 07/31 /24 15.60 2.630 11.80 2.460 18.00 2.740 14.70 2.580 19.90 2.830 15.10 2.610 16.30 .2.670 16.40 2.660 08/06/24 20.30 3.310 20.60 3.320 22.50 3.420 22.80 3.430 22.10 3.400 17.90 3.180 22.60 3.430 21.10 3.350 08/13/24 12.40 2.510 14.70 2.650 16.30 2.730 16.20 2.720 15.70 2.700 11.40 2.450 14.30 2.620 13.70 2.590 08/20/24 18.70 2.880 19.40 2.910 22.20 3.050 21.20 3.000 22.60 3.080 19.90 2.940 21.50 3.060 20.00 2.940 08/27/24 19.30 2.920 28.90 3.360 23.40 3.120 17.60 2.830 21.20 3.010 21.10 3.010 18.10 2.860 22.30 3.070 09104124 22.10 2.840 24.30 2.930 31.50 3.230 23.70 2.910 27.00 3.040 26.30 3.020 28.10 3.090 25.30 2.970 09/11 /24 1R10 2.820 19.00 2.870 21.10 2.970 18.80 2.860 18.30 2.830 21.70 3.000 19.20 2.880 15.50 2.680 09/18/24 23.10 3.080 22.20 3.050 28.80 3.340 24.40 3.150 29.40 3.. 370 22.70 3.060 22.20 3.050 22.00 3.030 09/25/24 19.20 2.920 16.70 2.800 20.60 2.990 19.30 2.930 16.40 2.790 16.40 2.790 15.60 2.740 14.10 2.660 10/02/24 12.50 2.600 9.800 2.430 13.60 2.590 12.60 2.570 13.00 2.610 10.80 2.490 11.40 2.520 10.10 2.450 10/08/24 30.70 3.680 24.70 3.390 33.50 3.880 31.00 3.730 31.70 3.730 26.20 3.470 28.60 3.580 28.80 3.590 10/16/24 21.40 2.700 23.70 2.820 26.00 2.920 23.70 2.830 27.00 2.960 25.20 2.870 22.20 2.750 22.30 2.750 10/22/24 26.40 3.560 18.20 3.150 23.90 3.440 25.70 3.530 26.70 3.590 22.90 3.410 21.70 3.330 19.80 3.230 10/29/24 31.90 3.490 31.90 3.610 32.60 3.520 29.00 3.370 32.60 3.520 27.90 3.320 29.70 3.400 30.80 3.440 11/05/24 19.70 2.950 18.50 2.900 23.70 3.140 20.80 3.010 22.40 3.090 19.90 2.970 19.80 2.960 19.30 2.930 11 /13/24 13.10 2.460 15.00 2.570 19.00 2.750 14.60 2.540 17.50 2.670 16.80 2.640 16.20 2.620 15.50 2.580 11 /19/24 16.70 3.190 19.70 3.340 21.40 3.420 20.30 3.360 16.90 3.210 18.30 3.280 16.70 3.180 16.70 3.180 11/26/24 24.00 3.020 24.50 3.050 33.90 3.470 17.90 2.720 23.50 3.000 22.40 2.940 24.40 3.040 24.20 3.030 12/03/24 21.40 3.090 19.60 3.010 22.20 3.130 16.30 2.840 18.30 2.940 17.80 2.910 18.10 2.930 17.10 2.880 12/10/24 22.90 3.180 19.60 3.020 26.30 3.330 22.40 3.150 20.70 3.070 21.10 3.090 21.00 3.090 21.70 3.110 12/17/24 16.40 2.760 16.40 2.760 18.30 2.860 13.80 2.630 17.10 2.790 16.80 2.780 15.30 2.710 16.70 2.780 12/23/24 14.70 3.030 14.60 3.030 20.20 3.330 15.90 3.100 17.70 3.220 13.30 2.970 14.00 3.000 14.10 3.000 12/31/24 20.00 2.630 21.30 2.690 24.40 2.830 22.00 2.730 17.50 2.500 20.50 2.650 16.40 2.450 23.40 2.790 Mean 17.43 2.825 15.98 2.750 18.56 2.875 16.66 2.785 17.59 2.888 16.51 2.785 16.06 2.756 16.25 2.761 34

TABLE 3-3 AIR PARTICULATES GROSS BETA RADIOACTIVITY (10-3 pCi/m3) LOCATIONS PERIOD ENDING 22 23 24* 01A 05A (+/-) (+/-) (+/-) (+/-) (+/-) 01/02/24 9.010 2.420 12.20 2.590 7.230 2.300 9.240 2.450 10.10 2.480 01/10/24 11.80 2.340 11.00 2.310 7.450 2.110 12.40 2.360 6.730 2.060 01/17/24 20.20 3.010 21.50 3.070 18.70 2.930 16.50 2.830 17.70 2.880 01/23/24 27.00 3.710 24.30 3.390 23.60 3.350 17.20 3.010 19.50 3.140 01/30/24 6.530 2.130 9.530 2.320 7.540 2.190 9.980 2.350 7.190 2.170 02/06/24 14.40 2.560 9.100 2.240 11.90 2.410 11.30 2.380 11.40 2.380 02/14/24 13.80 2.450 12.40 2.370 12.20 2.350 11.70 2.330 9.280 2.190 02/20/24 14.60 2.890 16.40 3.000 18.20 3.090 17.20 3.040 14.90 2.910 02/27/24 19.80 3.060 16.20 2.750 21.40 3.030 20.70 3.120 20.30 2.970 03/06/24 11.90 2.280 14.30 2.410 12.80 2.430 10.80 2.220 11.90 2.280 03/12/24 6.970 2.460 9.350 2.620 8.080 2.520 8.080 2.540 6.990 2.450 03/19/24 18.70 3.020 17.70 2.830 17.80 2.840 20.00 3.080 18.10 2.850 03/26/24 13.90 2.800 11.70 2.690 15.20 2.880 13.90 2.810 10.60 2.630 04/02/24 18.90 2.840 17.00 2.740 17.30 2.740 16.80 2.750 15.50 2.650 04/09/24 7.550 2.140 7.320 2.120 7.350 2.130 5.500 1.970 8.050 2.170 04/17/24 16.30 2.450 18.20 2.550 9.980 2.570 19.00 2.590 18.50 2.560 04/23/24 16.20 3.040 13.20 2.870 16.60 3.090 15.40 3.000 12.50 2.850 05/01/24 15.60 2.460 17.50 2.560 14.80 2.420 16.50 2.510 18.50 2.610 05/08/24 7.640 2.270 10.80 2.470 9.430 2.390 11.10 2.480 9.540 2.390 05/15/24 12.60 2.500 13.30 2.540 12.20 2.450 12.30 2.480 9.920 2.320 05/21/24 7.220 2.440 7.400 2.460 6.820 2.450 11.00 2.690 7.910 2.510 05/28/24 12.90 2.610 17.00 2.830 14.40 2.700 11.60 2.540 13.10 2.630 06/05/24 14.80 2.520 16.00 2.580 16.20 2.570 15.40 2.550 10.30 2.270 06/12/24 12.30 2.490 13.40 2.550 12.70 2.510 11.50 2.440 16.80 2.740 06/19/24 14.50 2.670 20.90 2.990 19.80 2.950 18.00 2.850 19.90 2.950 06/25/24 15.30 3.030 19.30 3.250 15.00 2.990 16.80 3.110 11.60 2.810

• Control Station 35

TABLE 3-3 AIR PARTICULATES GROSS BETA RADIOACTIVITY (10-3 pCi/m3) LOCATIONS PERIOD ENDING 22 23 24* 01A 05A (+/-) (+/-) (+/-) (+/-) (+/-) 07/02/24 16.40 2.760 14.80 2.670 13.00 2.570 17.90 2.850 16.80 2.780 07/09/24 18.40 2.950 17.90 2.920 11.10 2.540 17.30 2.880 18.80 2.960 07/17/24 16.90 2.590 20.30 2.870 19.70 2.740 16.70 2.570 15.10 2.500 07/23/24 17.60 3.260 12.40 2.980 16.00 3.180 12.20 2.970 16.80 3.360 07/31/24 14.20 2.560 17.50 2.720 17.20 2.710 15.60 2.630 19.40 2.810 08/06/24 23.00 3.440 23.80 3.480 22.40 3.410 12.30 2.870 21.70 3.370 08/13/24 13.70 2.590 17.60 2.800 16.80 2.740 13.40 2.570 17.20 2.770 08/20/24 20.90 2.980 15.00 2.680 23.40 3.110 17.70 2.820 20.70 2.990 08/27/24 20.70 2.980 22.90 3.090 21.60 3.030 19.40 2.920 20.90 2.990 09/04/24 21.70 2.820 24.20 2.920 23.10 2.880 25.20 2.970 24.90 2.960 09/11/24 20.00 2.930 20.10 2.930 19.80 2.900 16.00 2.720 19.20 2.870 09/18/24 24.10 3.120 25.70 3.200 25.50 3.190 22.60 3.060 30.10 3.390 09/25/24 17.00 2.810 17.50 2.840 15.60 2.750 16.50 2.780 21.60 3.050 10/02/24 11.10 2.500 13.40 2.630 10.80 2.480 7.880 2.320 14.90 2.710 10/08/24 28.80 3.610 31.80 3.750 29.10 3.610 29.30 3.620 38.00 4.000 10/16/24 24.60 2.850 21.30 2.700 24.10 2.830 21.60 2.720 30.30 3.210 10/22/24 21.10 3.300 21.20 3.310 21.70 3.350 20.60 3.280 30.50 3.920 10/29/24 32.80 3.530 31.50 3.470 29.80 3.400 29.60 3.390 40.30 3.970 11/05/24 26.00 3.390 21.10 3.020 22.10 3.190 17.90 2.870 26.40 3.400 11/13/24 18.50 2.720 18.20 2.710 14.90 2.660 14.80 2.550 18.00 2.810 11/19/24 19.90 3.340 15.90 3.140 22.40 3.490 17.00 3.200 24.10 3.580 11/26/24 22.40 2.950 27.50 3.180 24.30 3.040 26.60 3.150 32.60 3.540 12/03/24 18.70 2.960 19.70 3.010 21.50 3.090 21.20 3.080 25.70 3.420 12/10/24 24.60 3.670 19.50 3.010 21.80 3.120 19.70 3.030 32.00 3.710 12/17/24 13.30 2.600 17.50 2.830 16.40 2.750 16.80 2.780 21.60 3.150 12/23/24 14.80 3.030 16.40 3.120 17.20 3.200 13.00 2.930 22.80 3.470 12/31/24 17.40 2.500 21.70 2.710 24.50 2.830 19.00 2.590 29.40 3.160 Mean 16.96 2.818 17.42 2.826 16.99 2.815 16.18 2.766 18.62 2.900 Mean all Indicator locations 17.02 2.811

• Control Station 36

TABLE 3-4 AIRBORNE IODINE (10-3 pCi/m3) LOCATIONS PERIOD ENDING 01 02 03 04 05 06 07 21 01/02/24 < 26.61 < 26.33 < 12.61 < 25.88 < 26.06 < 30.95 < 15.95 < 31.06 01/10/24 < 17.41 < 17.63 < 7.509 < 17.77 < 17.68 < 19.49 < 46.46 < 45.41 01/17/24 < 32.36 < 32.36 < 32.19 < 32.19 < 13.76 < 44.68 < 18.80 < 44.60 01/23/24 < 63.02 < 62.89 < 63.94 < 67.91 < 28.80 < 53.70 < 57.50 < 55.18 01/30/24 < 34.90 < 14.66 < 34.66 < 34.66 < 34.96 < 20.71 < 49.38 < 48.38 02/06/24 < 13.05 < 19.51 < 19.51 < 19.51 < 19.51 < 21.22 < 19.16 < 19.16 02/14/24 < 26.34 < 26.34 < 26.26 < 15.28 < 15.28 < 15.28 < 11.67 < 15.26 02/20/24 < 15.13 < 15.59 < 15.59 < 22.85 < 25.36 < 22.90 < 22.85 < 22.85 02/27/24 < 20.37 < 19.83 < 8.434 < 19.90 < 19.90 < 14.99 < 18.40 < 18.44 03/06/24 < 27.58 < 27.54 < 27.54 < 27.54 < 12.29 < 20.40 < 13.66 < 20.40 03/12/24 < 20.33 < 48.09 < 48.38 < 48.38 < 48.29 < 33.97 < 25.98 < 33.97 03/19/24 < 27.78 < 21.16 < 27.88 < 27.92 < 27.88 < 43.55 < 40.79 < 41.00 03/26/24 < 10.87 < 25.97 < 25.97 < 25.97 < 25.97 < 14.47 < 6.76 < 14.47 04/02/24 < 10.32 < 21.48 < 21.37 < 21.37 < 21.37 < 22.31 < 22.31 < 22.20 04/09/24 < 18.80 < 18.90 < 21.20 < 19.14 < 19.00 < 21.80 < 21.80 < 9.473 04/17/24 < 16.56 < 16.56 < 16.59 < 16.59 < 21.66 < 16.50 < 16.58 < 16.60 04/23/24 < 20.31 < 20.35 < 20.35 < 20.39 < 9.714 < 12.93 < 30.65 < 30.65 05/01/24 < 22.42 < 20.25 < 20.25 < 20.25 < 20.25 < 20.16 < 20.16 < 20.16 05/08/24 < 33.99 < 34.05 < 34.05 < 34.05 < 14.30 < 16.36 < 24.46 < 24.46 05/15/24 < 11.38 < 27.03 < 27.03 < 27.03 < 26.89 < 27.03 < 27.13 < 27.13 05/21/24 < 23.77 < 23.92 < 23.87 < 23.92 < 10.18 < 10.44 < 15.73 < 15.73 05/28/24 < 36.44 < 15.36 < 36.31 < 36.31 < 36.63 < 15.52 < 20.38 < 19.96 06/05/24 < 37.69 < 37.46 < 37.75 < 37.81 < 15.66 < 34.53 < 34.59 < 14.80 06/12/24 < 14.78 < 22.06 < 22.06 < 22.02 < 22.06 < 29.13 < 29.08 < 13.77 06/19/24 < 10.03 < 20.76 < 20.76 < 20.76 < 20.80 < 12.59 < 24.65 < 24.65 06/25/24 < 43.11 < 43.02 < 43.02 < 55.62 < 56.30 < 56.41 < 23.66 < 56.41 PERIOD 37

TABLE 3-4 AIRBORNE IODINE (10-3 pCi/m3) LOCATIONS PERIOD ENDING 01 02 03 04 05 06 07 21 07/02/24 < 17.36 < 41.24 < 40.32 < 41.09 <41.17 < 14.79 < 31.29 < 31.24 07/09/24 < 22.20 < 22.20 < 22.72 < 26.49 < 23.54 < 23.38 < 23.50 < 23.50 07/17/24 < 21.92 < 17.87 < 22.06 < 22.06 < 22.02 < 24.74 < 24.81 < 24.78 07/23/24 < 23.35 < 23.35 < 23.31 < 23.35 < 11.79 < 16.41 < 11.72 < 15.45 07/31/24 < 22.67 < 17.51 < 22.70 < 22.70 < 22.74 < 16.63 < 24.86 < 24.78 08/06/24 < 16.68 < 39.35 < 39.35 < 39.35 < 39.43 < 37.84 < 41.99 < 37.91 08/13/24 < 21.63 < 21.67 < 21.63 < 21.63 < 16.53 < 22.78 < 22.86 < 22.86 08/20/24 < 24.88 < 24.88 < 18.95 < 24.88 < 25.01 < 28.32 < 13.68 < 28.17 08/27/24 < 32.14 < 32.14 < 24.48 < 32.14 < 32.14 < 36.18 < 36.18 < 36.24 09/04/24 < 31.68 < 31.58 < 31.58 < 11.97 < 28.29 < 28.29 < 28.29 < 28.25 09/11/24 < 26.50 < 12.08 < 26.55 < 26.50 < 26.46 < 24.96 < 25.05 < 24.96 09/18/24 < 26.38 < 29.37 < 26.47 < 26.52 < 26.42 < 25.63 < 10.90 < 25.72 09/25/24 < 24.07 < 24.11 < 24.11 < 22.54 < 22.61 < 25.04 < 22.54 < 22.54 10/02/24 < 11.50 < 25.15 < 24.46 < 24.80 < 25.10 < 9.36 < 22.08 < 22.08 10/08/24 < 27.26 < 27.26 < 18.85 < 27.77 < 27.32 < 28.59 < 28.59 < 28.59 10/16/24 < 25.79 < 25.95 < 25.91 < 21.66 < 19.38 < 19.35 < 19.43 < 19.43 10/22/24 < 20.48 < 20.48 < 15.60 < 20.48 < 20.60 < 13.44 < 17.53 < 17.53 10/29/24 < 19.83 < 20.97 < 19.80 < 14.60 < 21.83 < 21.83 < 21.83 < 21.83 11/05/24 < 26.80 < 24.20 < 24.20 < 24.20 < 24.20 < 20.32 < 20.32 < 20.32 11/13/24 < 20.80 < 10.15 < 20.83 < 20.83 < 20.70 < 14.71 < 32.53 < 32.53 11/19/24 < 25.75 < 25.70 < 25.65 < 25.65 < 17.33 < 28.15 < 25.26 < 25.26 11/26/24 < 29.49 < 29.49 < 22.50 < 29.54 < 29.49 < 15.66 < 33.01 < 33.01 12/03/24 < 29.28 < 32.49 < 29.33 < 29.28 < 29.28 < 24.55 < 32.23 < 32.23 12/10/24 < 15.48 < 32.58 < 32.58 < 32.52 < 32.58 < 13.44 < 26.32 < 26.27 12/17/24 < 18.54 < 20.60 < 18.60 < 18.60 < 18.51 < 23.05 < 23.17 < 23.17 12/23/24 < 36.33 < 36.41 < 36.41 < 36.41 < 18.75 < 18.53 < 40.48 < 40.40 12/31/24 < 28.08 < 25.32 < 25.32 < 25.36 < 25.28 < 23.96 < 23.96 < 10.17 38

TABLE 3-4 AIRBORNE IODINE (10-3 pCi/m3) LOCATIONS PERIOD ENDING 22 23 24* 01A 05A 01/02/24 < 31.01 < 30.90 < 26.90 < 27.37 < 27.04 01/10/24 < 46.25 < 46.39 < 29.79 < 29.24 < 29.74 01/17/24 < 44.83 < 44.83 < 48.21 < 48.38 < 48.21 01/23/24 < 27.58 < 53.59 < 28.45 < 67.97 < 68.11 01/30/24 < 49.30 < 49.21 < 33.63 < 33.63 < 33.69 02/06/24 < 19.16 < 19.16 < 17.02 < 17.02 < 17.02 02/14/24 < 17.54 < 17.54 < 7.39 < 17.54 < 17.49 02/20/24 < 26.00 < 26.00 < 25.95 < 26.00 < 12.55 02/27/24 < 19.53 < 18.37 < 30.57 < 32.52 < 30.52 03/06/24 < 20.43 < 20.43 < 17.92 < 16.86 < 16.84 03/12/24 < 34.11 < 34.11 < 38.51 < 38.91 < 38.51 03/19/24 < 18.30 < 40.86 < 30.24 < 32.23 < 30.24 03/26/24 < 14.45 < 14.47 < 18.13 < 18.13 < 18.13 04/02/24 < 17.05 < 22.39 < 21.96 < 22.38 < 21.99 04/09/24 < 21.88 < 21.84 < 17.67 < 17.39 < 17.61 04/17/24 < 16.60 < 18.41 < 20.25 < 15.34 < 15.32 04/23/24 < 30.58 < 30.58 < 25.35 < 25.14 < 25.35 05/01/24 < 20.16 < 13.50 < 25.26 < 25.34 < 25.30 05/08/24 < 24.41 < 24.46 < 17.76 < 17.63 < 17.70 05/15/24 < 27.22 < 20.74 < 24.25 < 24.59 < 24.38 05/21/24 < 15.67 < 15.70 < 25.26 < 24.85 < 25.16 05/28/24 < 20.31 < 20.31 < 23.59 < 23.55 < 23.59 06/05/24 < 34.74 < 34.74 < 25.77 < 25.97 < 25.73 06/12/24 < 29.18 < 29.13 < 17.01 < 17.07 < 17.04 06/19/24 < 24.61 < 24.57 < 25.03 < 24.86 < 24.95 06/25/24 < 46.15 < 46.15 < 19.08 < 46.05 < 45.96

• Control Station 39

TABLE 3-4 AIRBORNE IODINE (10-3 pCi/m3) LOCATIONS PERIOD ENDING 22 23 24* 01A 05A 07/02/24 < 31.24 < 31.18 < 28.51 < 28.71 < 28.56 07/09/24 < 22.73 < 22.73 < 22.53 < 22.65 < 15.13 07/17/24 < 24.70 < 12.48 < 24.20 < 24.01 < 24.13 07/23/24 < 15.41 < 15.45 < 13.99 < 13.96 < 14.80 07/31/24 < 24.82 < 24.82 < 26.90 < 26.82 < 26.90 08/06/24 < 37.84 < 37.84 < 36.56 < 36.49 < 36.49 08/13/24 < 15.32 < 22.86 < 19.46 < 19.64 < 19.50 08/20/24 < 28.17 < 28.17 < 26.24 < 26.19 < 26.33 08/27/24 < 17.16 < 36.18 < 32.73 < 32.61 < 32.61 09/04/24 < 22.25 < 14.86 < 22.32 < 22.32 < 22.29 09/11/24 < 10.63 < 25.09 < 22.20 < 22.39 < 22.27 09/18/24 < 25.59 < 25.63 < 33.05 < 33.05 < 33.05 09/25/24 < 24.30 < 24.30 < 24.43 < 24.26 < 10.32 10/02/24 < 22.04 < 22.04 < 19.64 < 19.81 < 19.71 10/08/24 < 28.77 < 13.12 < 28.79 < 28.73 < 28.79 10/16/24 < 24.54 < 24.54 < 24.58 < 12.52 < 26.10 10/22/24 < 17.53 < 17.53 < 25.47 < 25.31 < 27.09 10/29/24 < 20.05 < 20.05 < 9.683 < 20.05 < 21.28 11/05/24 < 14.53 < 20.32 < 32.12 < 30.33 < 32.29 11/13/24 < 32.53 < 32.53 < 24.24 < 22.86 < 24.20 11/19/24 < 25.26 < 25.26 < 14.89 < 14.76 < 14.89 11/26/24 < 33.01 < 33.01 < 35.02 < 35.08 < 37.23 12/03/24 < 32.23 < 32.23 < 33.48 < 33.48 < 35.67 12/10/24 < 31.55 < 26.27 < 28.30 < 28.35 < 30.14 12/17/24 < 9.821 < 23.17 < 22.65 < 22.77 < 24.21 12/23/24 < 40.40 < 40.40 < 33.34 < 32.86 < 33.20 12/31/24 < 24.03 < 24.03 < 30.68 < 30.87 < 32.67

• Control Station 40

TABLE 3-5 AIR PARTICULATES (10-3 pCi/m3) GAMMA SPECTRA - QTR 1 (12/26/23 - 03/26/24) LOCATION Be-7 Cs-134 Cs-137 (+/-) 01 110.30 19.920 < 1.1140 < 1.1530 02 79.650 18.520 < 1.3910 < 1.0540 03 99.450 24.260 < 1.7710 < 1.8310 04 117.70 17.420 < 1.0790 < 0.7640 05 84.000 20.510 < 1.2450 < 0.9303 06 92.720 21.190 < 1.2520 < 1.3110 07 100.60 20.520 < 1.0970 < 1.0420 21 90.450 20.600 < 1.5390 < 1.3400 22 109.70 23.770 < 1.4150 < 0.8853 23 108.70 17.370 < 1.2460 < 0.9534 24* 102.70 18.950 < 1.3070 < 0.8283 01A 67.240 21.930 < 1.7280 < 1.7230 05A 100.10 17.230 < 0.9599 < 0.9159 GAMMA SPECTRA AND STRONTIUM 89/90- QTR 2 (03/26/24 - 06/25/24) LOCATION Be-7 Cs-134 Cs-137 Sr-89 Sr-90 (+/-) 01 126.70 21.330 < 0.9820 < 0.8746 < 8.5600 < 2.4600 02 119.10 20.310 < 1.1460 < 1.0280 < 8.2000 < 2.3500 03 135.00 22.480 < 1.2570 < 1.0670 < 8.7500 < 2.1000 04 123.50 31.640 < 2.0820 < 1.6730 < 8.3200 < 2.7100 05 140.40 27.030 < 1.2470 < 1.2200 < 9.4800 < 2.8000 06 138.00 21.040 < 1.4910 < 0.9373 < 8.5500 < 2.1600 07 119.60 22.220 < 0.9791 < 1.0930 < 7.9600 < 2.0300 21 108.10 25.450 < 1.3810 < 1.3370 < 9.2300 < 2.5900 22 149.30 25.110 < 0.9697 < 1.1850 < 8.2000 < 2.7500 23 112.30 24.220 < 1.3390 < 1.3200 < 8.4300 < 3.7100 24* 120.60 19.350 < 0.9786 < 0.9173 < 9.2200 < 2.0400 01A 120.50 22.480 < 0.8329 < 0.8659 < 7.7900 < 2.2000 05A 139.60 26.070 < 1.3840 < 1.1470 < 6.7600 < 1.9700

• Control Location 41

TABLE 3-5 AIR PARTICULATES (10-3 pCi/m3) GAMMA SPECTRA - QTR 3 (06/25/24 - 09/25/24) LOCATION Be-7 Cs-134 Cs-137 (+/-) 01 144.20 25.590 < 1.2270 < 1.1690 02 116.40 25.540 < 1.9880 < 1.4660 03 185.40 38.870 < 2.6180 < 1.6540 04 107.60 17.030 < 0.8699 < 0.8877 05 152.00 24.840 < 1.0160 < 0.5504 06 127.10 25.710 < 1.7610 < 1.4230 07 131.20 34.050 < 1.7160 < 1.7600 21 126.80 20.750 < 1.2550 < 1.0640 22 125.40 23.830 < 1.6680 < 1.8200 23 121.80 23.040 < 1.3830 < 1.0020 24* 126.30 19.940 < 0.9069 < 0.8687 01A 99.830 23.160 < 1.1030 < 1.0640 05A 131.50 22.230 < 1.4200 < 1.0260 GAMMA SPECTRA - QTR 4 (09/25/24 - 12/31/24) Annual Mean LOCATION Be-7 Cs-134 Cs-137 Be-7 (+/-) (+/-) 01 96.490 18.150 < 0.7958 < 0.9650 119.42 21.25 02 90.820 17.850 < 1.0530 < 1.0880 101.49 20.56 03 135.80 22.790 < 0.9608 < 0.8180 138.91 27.10 04 106.30 16.660 < 0.8610 < 0.8493 113.78 20.69 05 137.70 25.990 < 1.5380 < 1.8930 128.53 24.59 06 100.50 18.360 < 0.7279 < 1.1010 114.58 21.58 07 74.510 17.620 < 1.3720 < 1.2270 106.48 23.60 21 104.90 18.880 < 1.4370 < 1.0260 107.56 21.42 22 89.510 18.000 < 0.8566 < 0.8024 118.48 22.68 23 104.60 21.220 < 0.9999 < 1.1160 111.85 21.46 24* 108.10 22.750 < 1.5830 < 1.3380 114.43 20.25 01A 93.620 16.810 < 1.3650 < 0.9713 95.298 21.10 05A 141.40 19.280 < 0.9010 < 0.8873 128.15 21.20 Mean of All Indicator Locations 115.38 22.268

• Control Location 42

LOCATION 01 02 03 04 05 06 07 21 22 23 24* 05A LOCATION 01 02 03 04 05 06 07 21 22 23 24* 05A Mean COLLECTION DATE COLLECTION DATE

• Control Location Sr-89 Sr-90 TABLE 3-6 Soil (pCi/kg dry wt.)

K-40 (+/-) Cs-134 Cs-137 (+/-) Soil sampled on Triennial basis. Not required in 2024 Th-228 Th-232 (+/-) (+/-) 43 Ra-226 (+/-)

TABLE 3-7 Precipitation (pCi/L) LOCATION 01A COLLECTION DATE Gr-B H-3 Rainfall (inches) (+/-) 01/30/24 < 1.5 < 1240 8.95 02/27/24 2.1 1.1 < 1250 1.49 03/26/24 < 1.7 < 1230 4.79 05/01/24 2.1 1.1 < 1230 3.59 05/28/24 < 1.6 < 1280 4.02 06/27/24 6.8 1.5 < 1230 1.75 07/31/24 3.0 1.2 < 250 4.63 08/27/24 5.3 1.3 < 1220 2.38 09/25/24 2.7 1.1 < 1260 5.32 10/29/24 2.5 1.5 < 1250 1.56 11/26/24 2.1 1.0 < 1220 2.18 12/31/24 2.5 1.1 < 1350 2.35 Mean 3.2 1.2 Total 43.01 44

COLLECTION DATE 06/27/24 12/31/24 Mean COLLECTION DATE 06/27/24 12/31/24 Mean Be-7 < 31.26 < 47.36 Nb-95 < 2.880 < 4.498 Mn-54 < 1.299 < 1.906 Cs-134 < 1.251 < 1.857 TABLE 3-7 Precipitation (pCi/L) Fe-59 LOCATION 01A Co-58 < 9.225 < 13.87 Cs-137 <1.119 < 1.660 < 2.539 < 3.819 Ba-140 < 645.5 < 1183 45 Co-60 < 1.276 < 1.725 La-140 < 231.6 < 381.1 Zn-65 < 2.818 < 3.928 1-131 < 4368 < 7866 Zr-95 < 5.196 < 7.302 Th-228 (+/-) < 2.210 4.855 3.947 4.855 3.947

OOllEC'flONI TABLE3-8 MJU< ~piCIJl) LOCA.TIIONI DATE K--40 Sr~Q Sr--90 1-131* ,~~ Cs.-134"' Os-137"' Ba-140"' la-1-40"" ~Hk sampl'.es co1tlld not be obtaiined in 2024 d ue to the llaclc: of dairy farms within l*he sampr.ing area~

• UD rdentlfled in OOCM 46

TABLE 3-9 Food and Vegetation (pCi/kg wet wt.) LOCATION 14B COLLECTION DATE Be-7 K-40 1-131 ** Cs-134** Cs-137** Th-228 ~ (+/-) (+/-) 04/09/24 4105 566.8 6596 901.4 < 44.80 < 44.64 < 44.93 < 98.69 05/15/24 511.0 166.5 3050 392.4 < 39.80 < 13.67 < 17.53 < 29.17 06/12/24 1848 429.8 4969 820.7 < 46.70 < 40.86 < 35.60 < 76.07 07/09/24 709.4 315.7 5338 813.9 < 38.40 < 43.18 < 40.47 97.14 54.98 08/13/24 983.3 234.1 4554 567.2 < 42.20 < 27.88 < 25.34 < 55.83 09/11/24 < 430.9 5955 873.0 < 46.80 < 35.88 < 38.84 < 74.40 10/08/24 1497 333.3 5438 722.8 < 48.30 < 30.23 < 32.24 < 50.50 Mean 1609 341.0 5129 727.3 97.14 54.98 LOCATION 15 COLLECTION DATE Be-7 K-40 1-131 ** Cs-134** Cs-137** Th-228 (+/-) (+/-) (+/-) 04/17/24 453.5 223.6 5254 662.7 < 41.40 < 28.51 < 16.69 < 49.91 05/15/24 611.2 213.8 3849 498.9 < 42.00 < 25.67 < 22.56 < 39.90 06/12/24 1074 339.7 5326 708.6 < 31.80 < 41.39 < 41.75 < 71.15 07/09/24 1128 211.5 3361 411.8 < 34.20 < 21.79 < 24.31 63.33 33.20 08/13/24 1559 341.6 3955 658.7 < 35.60 < 43.62 < 37.77 < 75.91 09/11/24 1258 312.3 4581 656.2 < 35.70 < 33.83 < 30.00 < 59.73 10/08/24 1613 364.2 3778 544.9 < 47.10 < 29.32 < 25.68 < 48.75 Mean 1100 286.7 4301 591.7 63.33 33.20 LOCATION 16* COLLECTION DATE Be-7 K-40 1-131 ** Cs-134** Cs-137** (+/-) (+/-) 04/09/24 1645 358.0 6049 772.2 < 37.50 < 39.69 < 30.47 05/15/24 1128 225.2 3960 473.6 < 44.50 < 18.97 < 20.00 06/12/24 956.2 361.8 6625 924.4 < 37.90 < 40.47 < 37.96 07/09/24 < 232.9 3849 508.6 < 20.40 < 22.28 < 21.15 08/13/24 2839 440.7 4123 766.5 < 37.20 < 38.92 < 50.35 09/11/24 2135 321.2 2974 533.6 < 39.10 < 37.59 < 34.78 10/08/24 3163 458.7 5008 649.2 < 36.40 < 38.64 < 30.44 Mean 1978 360.9 4655 661.2

• Control Station
  • LLD identified in ODCM 47

TABLE 3-9 Food and Vegetation (pCi/kg wet wt.) LOCATION 23 COLLECTION DATE Be-7 K-40 1-131 ** Cs-134** Cs-137** Th-228 Th-232 Ra-226 (+/-) (+/-) (+/-) (+/-) (+/-) 04/09/24 3087 549.1 6665 1021 < 42.40 < 57.72 < 62.08 < 89.22 < 262.7 < 1215 05/15/24 762.2 270.4 3584 607.8 < 40.70 < 38.91 < 31.25 < 50.79 < 158.1 < 686.9 06/12/24 < 399.3 4330 613.4 < 36.20 < 39.17 < 31.12 < 62.00 < 173.1 < 855.2 07/09/24 524.6 236.8 2967 443.0 < 39.10 < 34.42 < 28.32 135.9 54.47 335.6 70.29 918.1 600.2 08/13/24 1090 407.7 4720 805.2 < 28.10 < 46.63 < 36.50 93.39 48.55 < 213.8 < 787.4 09/11/24 991.6 383.9 3619 620.6 < 44.30 < 38.29 < 36.24 < 72.07 < 215.4 < 844.8 10/08/24 1524 355.3 2491 480.8 < 39.20 < 44.09 < 40.74 229.4 60.55 590.4 198.2 < 679.6 Mean 1330 367.2 4054 656.0 152.9 54.52 463.0 134.2 918.1 600.2 LOCATION 26 COLLECTION DATE Be-7 K-40 1-131** Cs-134** Cs-137** (+/-) (+/-) 04/09/24 2169 512.1 3562 763.1 < 45.90 < 46.34 < 50.87 05/15/24 379.5 301.4 2515 390.5 < 39.60 < 27.48 < 22.43 06/12/24 411.9 259.1 2294 502.0 < 36.20 < 32.86 < 26.95 07/09/24 671.1 267.5 1936 368.1 < 38.00 < 30.41 < 25.36 08/13/24 1601 387.5 4018 696.7 < 34.40 < 33.46 < 30.14 09/11/24 < 393.2 2027 476.4 < 45.40 < 36.10 < 34.35 10/08/24 568.8 317.2 1727 435.8 < 40.10 < 31.77 < 33.26 Mean 966.9 340.8 2583 518.9 Be-7 K-40 1-131** Cs-134** Cs-137** Th-228 Th-232 Ra-226 (+/-) (+/-) (+/-) (+/-) (+/-) All Indicator Mean 1245 332.0 4016 623.5 123.8 50.35 463.0 134.2 918.1 600.2

• • LLD identified in ODCM 48

TABLE 3-10 WELL WATER (pCi/L) COLLECTION LOCATION DATE H-3 Sr-89 Sr-90 Mn-54 Fe-59 Co-58 Co-60 Zn-65 01A 03/26/24 < 1220 (a) (a) < 5.23 < 10.8 < 5.24 < 5.32 < 11.5 06/25/24 < 1250 < 1.81 < 0.883 < 6.21 < 13.2 < 5.76 < 6.80 < 13.6 09/25/24 < 1260 (a) (a) < 5.29 < 12.5 < 5.57 < 5.55 < 12.2 12/31/24 < 1330 (a) (a) < 4.78 < 10.5 < 6.05 < 6.75 < 13.9 Mean COLLECTION LOCATION DATE Zr-95 Nb-95 1-131 Cs-134 Cs-137 Ba-140 La-140 01A 03/26/24 < 9.25 < 7.00 < 6.49 < 6.13 < 5.45 < 23.4 < 8.04 06/25/24 < 10.0 < 7.76 < 9.28 < 6.55 < 6.74 < 21.6 < 8.06 09/25/24 < 10.5 < 7.67 < 8.91 < 6.11 < 6.17 < 30.8 < 10.6 12/31/24 < 9.69 < 7.39 < 9.62 < 7.20 < 5.44 < 28.3 < 10.3 Mean (a) Sr-89/90 analyses performed on the second quarter sample. 49

TABLE 3-11 River Water (pCi/L) LOCATION 11 COLLECTION DATE H-3 Sr-89 Sr-90 Mn-54* Fe-59* Co-58* Co-60* Zn-65* (+/-) 01/17/24 (a) (b) (b) < 2.870 < 6.553 < 2.799 < 3.720 < 5.959 02/14/24 (a) (b) (b) < 4.748 < 9.917 < 5.686 < 5.825 < 12.25 03/12/24 6740 989.0 (b) (b) < 4.874 < 8.399 < 4.649 < 5.178 < 8.995 04/17/24 (a) (b) (b) < 3.496 < 10.77 < 4.834 < 6.166 < 10.70 05/15/24 (a) (b) (b) < 7.088 < 10.07 < 6.135 < 8.535 < 12.37 06/12/24 4720 957.0 < 3.270 < 0.870 < 5.696 < 7.778 < 5.851 < 5.545 < 12.08 07/17/24 (a) (b) (b) < 4.818 < 14.09 < 4.797 < 7.113 < 10.99 08/13/24 (a) (b) (b) < 3.793 < 7.943 < 4.411 < 6.897 < 12.64 09/18/24 1850 873.0 (b) (b) < 5.826 < 10.68 < 5.238 < 4.897 < 11.11 10/16/24 (a) (b) (b) < 6.380 < 10.24 < 6.332 < 6.476 < 14.05 11/13/24 (a) (b) (b) < 5.823 < 9.775 < 4.985 < 5.359 < 12.01 12/17/24 2780 947.0 (b) (b) < 2.795 < 5.470 < 2.974 < 3.063 < 5.798 Mean 4022.5 941.5 Nb-95* Zr-95* 1-131* Cs-134* Cs-137* Ba-140* La-140* 01/17/24 < 3.333 < 5.565 < 0.938 < 2.984 < 3.035 < 18.34 < 6.772 02/14/24 < 5.248 < 10.68 < 0.384 < 4.763 < 5.355 < 25.16 < 11.56 03/12/24 < 5.138 < 9.100 < 0.769 < 6.032 < 6.046 < 17.27 < 6.353 04/17/24 < 7.079 < 11.06 < 0.791 < 5.557 < 6.523 < 25.39 < 8.328 05/15/24 < 7.096 < 10.24 < 0.766 < 6.731 < 5.718 < 27.33 < 8.411 06/12/24 < 6.135 < 8.269 < 0.792 < 5.134 < 6.188 < 26.17 < 9.700 07/17/24 < 6.046 < 11.60 < 0.858 < 6.623 < 4.772 < 25.65 < 6.535 08/13/24 < 4.249 < 9.510 < 0.837 < 5.429 < 4.751 < 16.86 < 5.533 09/18/24 < 5.506 < 8.706 < 0.871 < 6.811 < 5.032 < 23.64 < 8.880 10/16/24 < 7.427 < 10.63 < 0.728 < 7.173 < 6.274 < 30.20 < 9.853 11/13/24 < 5.171 < 10.23 < 0.870 < 6.087 < 6.313 < 24.77 < 7.679 12/17/24 < 2.964 < 5.230 < 0.847 < 3.085 < 3.364 < 12.26 < 2.739 Mean

• LLD identified in ODCM.

(a) Tritium analyses on quarterly composite. (b) Sr-89/90 performed on 2nd quarter composite sample. 50

TABLE 3-12 Surface Water (pCi/L) LOCATION 08 COLLECTION DATE H-3 Sr-89 Sr-90 Mn-54* Fe-59* Co-58* Co-60* Zn-65* (+/-) 01/17/24 (a) (b) (b) < 1.386 < 3.702 < 1.483 < 1.570 < 3.099 02/14/24 (a) (b) (b) < 6.478 < 12.63 < 5.600 < 3.803 < 11.90 03/12/24 6080 967.0 (b) (b) < 5.140 < 12.25 < 5.884 < 5.722 < 12.04 04/17/24 (a) (b) (b) < 5.496 < 11.96 < 4.559 < 7.681 < 12.61 05/15/24 (a) (b) (b) < 4.924 < 13.95 < 6.069 < 4.261 < 8.471 06/12/24 5490 979.0 < 3.730 < 0.973 < 5.189 < 13.66 < 5.386 < 6.506 < 13.81 07/17/24 (a) (b) (b) < 5.116 < 11.58 < 5.087 < 5.595 < 12.33 08/13/24 (a) (b) (b) < 5.390 < 13.81 < 5.383 < 7.767 < 12.64 09/18/24 4380 980.0 (b) (b) < 5.714 < 11.48 < 4.851 < 7.148 < 11.37 10/16/24 (a) (b) (b) < 6.399 < 10.75 < 6.267 < 7.119 < 17.44 11/13/24 (a) (b) (b) < 7.011 < 11.57 < 5.642 < 7.080 < 11.54 12/17/24 2900 957.0 < 2.842 < 6.415 < 2.722 < 3.810 < 5.807 Mean 4712.5 970.8 Nb-95* Zr-95* 1-131* Cs-134* Cs-137* Ba-140* La-140* 01/17/24 < 1.663 < 2.871 < 0.780 < 1.388 < 1.482 < 14.01 < 5.352 02/14/24 < 7.002 < 12.62 < 0.759 < 5.882 < 5.650 < 26.53 < 9.505 03/12/24 < 4.897 < 9.811 < 0.820 < 5.111 < 5.847 < 26.04 < 6.889 04/17/24 < 6.392 < 11.68 < 0.868 < 4.869 < 6.610 < 22.89 < 6.951 05/15/24 < 7.084 < 8.750 < 0.735 < 6.468 < 5.941 < 26.24 < 8.797 06/12/24 < 6.627 < 9.820 < 0.779 < 7.116 < 5.130 < 25.44 < 7.999 07/17/24 < 5.313 < 7.059 < 0.730 < 5.113 < 6.138 < 28.08 < 8.795 08/13/24 < 5.364 < 10.54 < 0.817 < 7.244 < 6.582 < 24.54 < 8.855 09/18/24 < 4.538 < 9.680 < 0.926 < 5.425 < 5.006 < 20.62 < 10.10 10/16/24 < 7.325 < 10.45 < 0.743 < 6.654 < 5.793 < 28.64 < 11.44 11/13/24 < 7.101 < 10.61 < 0.717 < 8.566 < 6.762 < 25.28 < 8.716 12/17/24 < 3.214 < 4.867 < 0.808 < 3.455 < 3.446 < 13.46 < 3.392 Mean

• LLD identified in ODCM.

(a) Tritium analyses on quarterly composite. (b) Sr-89/90 performed on 2nd quarter composite sample. 51

COLLECTION DATE 01/17/24 02/14/24 03/12/24 04/17/24 05/15/24 06/12/24 07/17/24 08/13/24 09/18/24 10/16/24 11/13/24 12/17/24 Mean 01/17/24 02/14/24 03/12/24 04/17/24 05/15/24 06/12/24 07/17/24 08/13/24 09/18/24 10/16/24 11/13/24 12/17/24 Mean

• LLD identified in ODCM.
  • Control location.

H-3 (a) (a) < 1180 (a) (a) < 1230 (a) (a) < 1280 (a) (a) < 1350 Nb-95* < 1.894 < 6.301 < 4.062 < 4.977 < 5.333 < 6.250 < 4.885 < 5.854 < 4.408 < 7.074 < 4.746 < 3.625 (a) Tritium analyses on quarterly composite. Sr-89 (b) (b) (b) (b) (b) < 4.690 (b) (b) (b} (b} (b) Zr-95* < 3.440 < 8.899 < 7.654 < 5.579 < 10.18 < 10.13 < 7.956 < 8.536 < 7.145 < 10.31 < 8.742 < 6.258 (b) Sr-89/90 performed on 2nd quarter composite sample. Sr-90 (b) (b) (b) (b) (b) < 0.876 (b) (b) (b) (b) (b) 1-131* < 0.908 < 0.700 < 0.764 < 0.852 < 0.775 < 0.796 < 0.744 < 0.845 < 0.873 < 0.871 < 0.874 < 0.811 TABLE 3-12 Surface Water (pCi/L) LOCATION 09A ** Mn-54* Fe-59* Co-58* Co-60* Zn-65* < 1.756 < 3.958 < 1.979 < 1.928 < 3.506 < 6.246 < 12.72 < 6.194 < 6.065 < 14.82 < 4.296 < 7.936 < 4.875 < 5.402 < 8.873 < 4.478 < 10.32 < 4.757 < 6.306 < 12.09 < 5.733 < 14.41 < 5.517 < 6.314 < 12.40 < 6.510 < 10.05 < 5.388 < 6.210 < 11.65 < 4.593 < 8.773 < 5.176 < 4.851 < 7.587 < 5.735 < 10.11 < 4.912 < 5.977 < 6.471 < 4.319 < 13.37 < 5.275 < 4.943 < 9.688 < 5.537 < 11.61 < 8.004 < 6.224 < 14.53 < 5.267 < 10.67 < 5.752 < 6.345 < 9.902 < 3.250 < 6.324 < 3.347 < 3.681 < 7.160 Cs-134* Cs-137* Ba-140* La-140* < 1.955 < 1.747 < 17.47 < 6.341 < 6.034 < 5.754 < 24.78 < 8.036 < 4.670 < 4.459 < 16.58 < 8.117 < 4.884 < 5.875 < 21.23 < 8.354 < 5.722 < 5.177 < 21.47 < 5.705 < 6.270 < 5.934 < 32.68 < 5.835 < 4.731 < 4.726 < 20.55 < 7.917 < 6.664 < 3.807 < 23.42 < 7.817 < 4.809 < 5.212 < 21.76 < 7.999 < 6.855 < 7.027 < 27.58 < 10.89 < 4.974 < 5.993 < 24.71 < 7.464 < 3.988 < 3.534 < 13.89 < 4.335 52

LOCATION 08 09A* 11 08 09A* 11 LOCATION 08 09A* 11 08 09A* 11 COLLECTION DATE 04/18/24 04/18/24 04/18/24 10/03/24 10/03/24 10/03/24 Indicator Mean Control Mean COLLECTION DATE 04/18/24 04/18/24 04/18/24 10/03/24 10/03/24 10/03/24 Indicator Mean Control Mean Sr-89 (a) (a) (a) < 668.0 < 734.0 < 550.0 Th-228 (+/-) 101.6 73.84 127.3 64.23 1154 80.99 < 130.1 291.7 99.20 1440 201.6 898.5 118.8 209.5 81.72 (a) Sr-89/90 analyses performed annually.

• Control location, Background location TABLE 3-13 Sediment Silt (pCi/kg dry wt.)

Sr-90 K-40 Cs-134 Cs-137 Ra-226 (+/-) (+/-) (a) 1288 521.5 < 50.53 < 43.06 < 911.2 (a) 10970 1047 < 57.36 < 50.24 < 982.4 (a) 17560 1128 < 60.28 < 50.67 2198 967.4 < 39.50 1609 615.8 < 69.68 < 53.39 < 1189 < 42.10 10670 1525 < 84.02 < 91.11 < 1623 < 40.90 23390 2066 < 100.4 < 88.26 < 1932 10962 1083 2198 967.4 10820 1286 Th-232 (+/-) < 198.2 < 220.2 989.4 114.6 < 286.4 < 394.2 1287 203.5 1138 159.1 53

COLLECTION LOCATION DATE Sr-89 08 04/18/24 (a) 08 10/03/24 < 815.0 Mean COLLECTION LOCATION DATE Th-228 (+/-) 08 04/18/24 < 66.13 08 10/03/24 124.1 82.01 Mean 124.1 82.01

• LLD identified on ODCM (a) Sr-89/90 analyses performed annually.

Sr-90 (a) < 42.80 Th-232 < 151.1 < 209.7 TABLE 3-14 Shoreline Soil (pCi/kg dry wt.) LOCATIONS K-40 (+/-) 857.5 389.5 1976 724.5 1417 557.0 54 Cs-134* < 42.62 < 47.96 Cs-137* < 32.13 < 56.31 Ra-226 < 760.6 < 1099

LOCATION Fish Type 08 (a) (b) (a) (b) 25** (a) (b) (a) (b) LOCATION 08 (a) (b) (a) (b) 25** (a) (b) (a) (b)

• LLD identified in ODCM
  • Control Station COLLECTION DATE 05/07/24 05/07/24 11/12/24 11/12/24 05/14/24 05/14/24 11/19/24 11/19/24 Mean Indicator Mean Control Mean COLLECTION DATE 05/07/24 05/07/24 11/12/24 11/12/24 05/14/24 05/14/24 11/19/24 11/19/24 Mean Indicator Mean Control Mean (a) Non-bottom dwelling species of gamefish.

(b) Bottom dwelling species of fish. TABLE 3-15 Fish (pCi/kg wet wt.) K-40 Mn-54* Fe-59* Co-58* Co-60* Zn-65* (+/-) 2135 638.2 < 57.98 < 99.22 < 62.79 < 63.25 < 135.6 1912 692.4 < 46.23 < 105.0 < 47.36 < 59.64 < 91.41 2959 1002 < 74.59 < 182.0 < 81.37 < 87.99 < 172.9 1369 506.8 < 36.70 < 88.50 < 43.05 < 46.76 < 95.52 1930 979.9 < 63.54 < 156.4 < 65.59 < 46.96 < 162.1 2401 881.2 < 67.10 < 154.2 < 71.68 < 96.96 < 151.1 2094 517.5 < 29.83 < 66.73 < 29.19 < 54.92 < 72.79 1906 645.3 < 51.40 < 93.39 < 46.34 < 55.13 < 110.8 2088 732.9 2094 709.9 2083 756.0 Cs-134* Cs-137* < 58.17 < 50.61 < 67.55 < 56.25 < 75.49 < 82.41 < 37.75 < 47.25 55

4. DISCUSSION OF RESULTS Data from the radiological analyses of environmental media collected during 2024 and tabulated in Section 3, are discussed below. Except for TLDs, Teledyne Brown Engineering analyzed all samples throughout the year. The procedures and specifications followed for these analyses are as required in the TBE quality assurance manuals and laboratory procedures. In addition to internal quality control measurements performed by each laboratory, they also participate in an Interlaboratory Comparison Program. Participation in this program ensures that independent checks on the precision and accuracy of the measurements of radioactive material in environmental samples are performed. The results of the Interlaboratory Comparison Programs are provided in Appendix B.

The predominant radioactivity detected throughout 2024 was that from external sources, such as fallout from nuclear weapons tests and naturally occurring radionuclides. Naturally occurring nuclides such as Be-7, K-40, Th-228 and Th-232 were detected in numerous samples. Th-228 & Th-232 results were variable and are generally at levels higher than plant related radionuclides. In the past, Cs-13 7, a plant related nuclide, has been detected in soil and aquatic sediment samples at levels corresponding to levels associated with fallout from nuclear weapons tests. The following is a discussion and summary of the results of the environmental measurements taken during the 2024 reporting period. 4.1 Gamma Exposure Rate A thermoluminescent dosimeter (TLD) is an inorganic crystal used to detect ambient radiation. TLDs are placed in two concentric rings around the station. The inner ring is located at the site boundary, and the outer ring is located at approximately five miles from the station. TLDs are also placed in special interest areas, such as population areas and nearby residences. Additional TLDs serve as controls. Ambient radiation comes from naturally occurring radioisotopes in the air and soil, radiation from cosmic origin, fallout from nuclear weapons testing, station effluents and direct radiation from the station. The results of the analyses are presented in Table 3-2. Figure 4-1 shows the historical trend of TLD exposure rate measurements. Control and indicator averages indicate a steady relationship. Prior to January 2001 TLDs made of CaSO4:Dy in Teflon were used. From January 2001 until 2024 two TLDs made of CaF and LiF sensitive elements were deployed at each sampling location. Starting with the 2024 sampling period, the CaF and LiF TLDs were replaced with dosimeters using the same type CaSO4:Dy elements that were in the dosimeters prior to January 2001. The dose with the replacement TLDs is higher than that of the TLDs used from 2001 until 2024. This will continue to be monitored. 56

9.0 8.0 7.0 ,s;:; ~ s:: 6.0 0

E

-d ~ 5.0 (I) 0:: E Environmental TLD 4.0 sectorTLD 3.0 2.0 1.0 0.0 Figure 4-1 TLD (mrem/Standard Month) Sector TLDs are deployed quarterly at thirty-two locations in the environs of the North Anna site. Two badges are placed at each location. The average level of these 32 sector TLD locations (two badges at each location) was 5.3 mR/standard month with a range of 1.4 to 10.2 mR/standard month. The highest quarterly average reading for any single location was obtained at location NW-29/61. This value was 9.2 mR/standard month. This location is on site on the Laydown Area north gate. Quarterly and annual TLDs are also located at twelve environmental air sampling stations. For the eleven indicator locations within 10 miles of the station the average quarterly reading was 4.4 mR/standard month with a range of 1.7 to 6.0 mR/standard month. The average annual reading for these locations was 3.0 mR/standard month with a range from 1.8 to 7.8 mR/standard month. The control location showed a quarterly average of 4.0 mR/standard month with a range of 3.1 to 4.5 mR/standard month. Its annual reading was 3.3 mR/standard month. 10 emergency sector TLDs, which are all located onsite had a quarterly average of 6.1 mR/standard month with EPSR-5/6 having the highest quarterly average of 7.9 mR/standard month. Eight other TLDs, designated C-1 thru C-8, which were pre-operational controls, were collected quarterly from four locations. Stations C-3/4 and C-7 /8 are designated controls. These had a quarterly average of 4.1 mR/ standard month, while Station C-1/2 and C-5/6 had a quarterly average of 3.5 mR/standard month with a range of 1.1 to 5.0 mR/standard month. During the pre-operational period (starting in 1977) the doses were measured between 4.3 and 8.8 mR/standard month. 4.2 Airborne Gross Beta Results of the weekly gross beta analyses are presented in Table 3-3. A review of the historical plot in Figure 4-2, indicates gross beta activity levels have remained relatively unchanged. The drop indicated in 2009 is a function of a return to the vendor used from 1988 until 2001. Inner and outer ring monitoring locations continue to show no significant variation in measured activities (see Figure 4-3). This indicates that any station contribution is not measurable. Gross beta activity found during the pre-operational and early operating period of North Anna Power Station was higher because of nuclear weapons testing. During that time, nearly 740 nuclear weapons were tested worldwide. In 1985 weapons testing ceased, and with the exception of the Chernobyl accident in 1986, airborne gross beta results have remained steady. During the preoperational period of July 1, 197 4 through March 31, 1978 gross beta activities ranged from a low of0.005 pCi/m3 to a high of0.75 pCi/m3. 57

0.12 0.1 0.08 ('f) E control u 0.06 0.. Indicator Average Pre-Op 0.04 Required LLD 0.02 0 00 en ("() '<:j-I.O 00 en .-l ("() '<:j-I.O 00 en ("() '<:j-I.O 00 en .-l ("() <id" 00 00 qi en en qi en en 9 0 0 9 0 0 .--t .--t ~.-l .-l ~ N N C:

6.

C:

6.

C:

6. >-

C:

6.

C:

6.

C: Cl. C:

6.

C: Cl. ~ Q) ("O ~ Q) ("O ~ Q) ("O ~ Q) ("O ~ Q) ("O ~ Q) ("O ~ Q) ("O ~ Q) \\I') 2 \\I') 2 VI 2 \\I') 2 (/') 2 VI 2 \\I') 2 \\I') Figure 4-2 Historical Gross Beta in Air Particulates 3.00E-02 2.SOE-02 2.00E-02 ('f) E 1.SOE-02 u control 0.. 1.00E-02 Indicator 5.00E-03 O.OOE+OO N N ("() ("() '<:j- '<:j-LI) I.O I.O r-- r-- 00 en en 0 0 .-l .--t N ("() ("() '<:j- '<:j- .--i ~ 2 z ~ 7 1 .,..; 7 '2 .--t .--t ~ 1 r;-i ~ 1 N N ~ N C: 00 u J:i

a.

> C: C: 00 u J:i Cl.

0. >

~

l

("O u ("O Q) ~ Q) Q)

a.

0 ~ ~

l

("O u ("O Q) ~ Q) Q) 0 <( 2 0 2 0 u.. \\I') <( z <( 2 0 2 0 u.. VI <( z Figure 4-3 2022 Gross Beta in Air Particulates (pCi/m3) 4.3 Airborne Radioiodine Charcoal cartridges are used to collect airborne radioiodine. Once a week the samples are collected and analyzed. The results of the analyses are presented in Table 3-4. These results are similar to pre-operational data and the results of samples taken prior to and after the 1986 accident in the Soviet Union at Chernobyl and the effect of the Fukushima Daiichi event. 58

4.4 Air Particulate Gamma The air particulate filters that are utilized for the weekly gross beta analyses are composited by location and analyzed quarterly by gamma spectroscopy. The results are listed in Table 3-5. The results indicate the presence of naturally occurring Be-7, which is produced by cosmic processes. Examination of pre-operational data indicates comparable measurements of Be-7, as would be expected. The results of these analyses indicate the lack of station effects on the environment. 4.5 Air Particulate Strontium Strontium-89 and 90 analyses are performed on the second quarter composites of air particulate filters from all monitoring stations. There has been no detection of these fission products at any of the indicator or control stations in recent years. 4.6 Soil Soil samples, which are collected every three years from twelve stations, were not scheduled for collection in 2024. During the preoperational phase Cs-13 7 was routinely detected and was attributed to fallout. Levels during this phase varied by location and date and ranged from 88 to 1390 pCi/Kg. The average was 645 pCi/kg. The current levels are also varied significantly by location and date. The decrease in the average, and the fact that the averages for the control location and the indicator locations are similar is indicative of fallout.

4. 7 Precipitation A sample of rain water was collected monthly, when available, at on-site station 0lA and analyzed for gross beta activity and H-3. The results are presented in Table 3-7. Twelve precipitation samples were obtained in 2024. Semi-annual composites are prepared and analyzed for gamma emitting isotopes in accordance with program requirements. No plant related isotopes were reported in any precipitation water sample at the indicator location. Naturally occurring gamma emitting radioisotope Th-228 was detected in one indicator station sample. No positive H-3 result was reported. During the pre-operational period gross beta activity in rain water was expressed in nCi per square meter of the collector surface, thus a direct comparison cannot be made to the 2024 period. During the pre-operational period, tritium was measured in over half of the few quarterly composites made. This tritium activity ranged from 100 to 330 pCi/liter.

4.8 CowMilk Milk samples were unavailable during the reporting period due to the closure of the final operating dairy within the sampling area on 1/1/18. 4.9 Food Products and Vegetation Food/vegetation samples were collected from five locations and analyzed by gamma spectroscopy. The results of the analyses are presented in Table 3-9. Low levels of Cs-137, attributable to fallout, have been seen periodically in vegetation samples. Cosmogenic beryllium-7 was detected in thirty one of thirty five samples. Naturally occurring potassium-40 was detected in all samples. Naturally occurring thorium-228 was detected in five of thirty five samples. Naturally occurring radium-226 was detected in one of thirty five samples and naturally occmTing thorium-232 was detected in two of thirty five samples. No plant related isotopes were identified in any vegetation sample during 2024. 4.10 Well Water Water was sampled quarterly from the onsite well at the metrology laboratory. These samples were analyzed for gamma radiation and for tritium. The second quarter sample was analyzed by vendor for Sr-89, Sr-90, H-3, I-131, and gamma emitters. The results of these analyses are presented in Table 3-10. No plant related isotopes were detected. No gamma 59

emitting isotopes were detected during the pre-operational period. 4.11 River Water Samples of water from the North Anna River were collected monthly. The analyses are presented in Table 3-11. All monthly samples are analyzed by gamma spectroscopy. The monthly samples are composited quarterly and analyzed for tritium. Additionally, the second quarter samples are analyzed for strontium-89 and strontium-90 in accordance with program requirements. There has been no detection of these fission products at any of the indicator or control stations in recent years. No gamma emitting radioisotopes were positively identified in any of the samples. There was no measured activity of strontium-89 or strontium-90. Tritium was measured in all four samples with an average annual concentration of 4023 pCi/liter and a range of 1850 to 6740 pCi/liter, see Figure 4-4. No river water samples were collected during the pre-operational period. 10000 9000 8000 7000 6000 ....J ..... u 5000 Tritium C. 4000 Required LLD 3000 2000 1000 0 Figure 4-4 Tritium in River water 4.12 Surface Water Samples of surface water were collected monthly from two stations, an indicator station located at the discharge lagoon and a control station located 12.9 miles WNW. The samples were analyzed by gamma spectroscopy and for iodine-131 by radiochemical separation. A quarterly composite from each station was prepared and analyzed for tritium. Additionally, the second quarter samples are analyzed for strontium-89 and strontium-90. There has been no positive indication of these fission products at any of the indicator or control stations in recent years. The results are presented in Table 3-12. No non-naturally occurring gamma emitting radioisotopes, including iodine were detected in any of the samples. Tritium was not detected in any sample at the control location. The average level of tritium activity at the indicator location was 4 713 pCi/L with a range of 2900 to 6080 pCi/L. 60

20000 18000 16000 14000 .....1 12000 ~ 10000 8000 6000 4000 2000 _f-\\ = 0 N N M M 'V 'V c :5 c :5 c :5 ,u ,u ,u 4.13 Bottom Sediment i.n i.n c :5 ,u Tritium Required LLD Avg. Pre-Op '° '° r--... " 00 00 °' °' 0 0 ...- N N N M M 'V 'V N N N N N N N N N c :5 c :5 c :5 i::. :5 C: :5 C :5 C :5 C: :5 C :5 n:s n:s ,u ,u ,u ,u n:s ,u ,u Figure 4. 5 Tritium in Surface Water Bottom sediment or silt is sampled to evaluate any buildup of radionuclides in the environment due to the operation of the station. Buildup of radionuclides in bottom sediment could indirectly lead to increasing radioactivity levels in fish. Sediment samples were collected during April and October from each of three locations and were analyzed by gamma spectroscopy. The October samples were analyzed for strontium-89 and strontium-90. The results are presented in Table 3-13. Cs-13 7 which historically has been detected periodically in sediment samples was not detected in any bottom sediment sample during 2024. The detection of Cs-137 in bottom sediment is historically common with positive indications usually apparent in both indicator and control samples. The detection of Cs-137 is the result of accumulation and runoff into the lake of residual weapons testing fallout; its global presence has been well documented. During the pre-operational period sediment samples were also analyzed by gamma spectroscopy. Levels during this phase varied by location and date and averaged 360 pCi/kg. Figure 4-6 shows the historical trend of Cs-137 in sediments. Neither Strontium-89 nor Strontium-90 was detected in any samples of aquatic sediment/silt in 2024. Strontium-90 has been detected occasionally in the past at both the indicator and control locations and is attributable to fallout from past bomb tests. Several naturally occurring radioisotopes were detected in these samples at background levels. 61

500 450 400 350 ~ 300 ...... u 250 C. 200 150 100 50 0 °' 0 '?' 9 ..0..0 a, a, LL. LL. 4.14 Shoreline Soil 9 ..0 a, LL. N M 'V U') '° r--. 9 9 9 9 9 9 ..0..0..0..0..0..0 a, a, a, a, a, a, LL. LL. LL. LL. LL. LL. station 08 station 09A station 11 Pre-Operational 00 °' 0 N M 'V U') '° r--. 00 °' 0 N M 'V 9 9 ~ ~ ~ ~ ~ ..0..0..0..0..0..0..0..0..0..0..0..0..0..0..0..0..0 a, a, a, a, a, a, a, a, a, a, a, a, a, a, a, <1J a, LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. LL. Figure 4-6 Cs-13 7 in Sediment/Silt Shoreline soil/sediment, unlike bottom sediment, may provide a direct dose to humans. Buildup of radioisotopes along the shoreline may provide a source of direct exposure for those using the area for commercial and recreational uses. Samples of shoreline soil were collected in April and October from indicator station 08. The samples were analyzed by gamma spectroscopy. The October sample was analyzed for strontium-89 and strontium-90. The results are presented in Table 3-14. Naturally occurring radioisotopes were detected at concentrations equivalent to normal background activities. No plant related isotopes were detected in any indicator samples analyzed. Strontium-90 is often detected in this media, however as discussed previously, the presence of Sr-90 and Cs-137 is attributed to accumulation of residual global fallout from past atmospheric weapons testing. 4.15 Fish Four sample sets of fish, two from Lake Anna and two from the control station, Lake Orange, were collected during 2024 and analyzed by gamma spectroscopy. Each sample set consisted of a sample of game species and a sample of bottom-dwelling species, which were analyzed separately. The results are presented in Table 3-15. Naturally occurring K-40 was detected in all samples. No plant related isotopes were detected. Cs-137 was measured in pre-operational environmental fish samples. 62

5. PROGRAM EXCEPTIONS REMP Exceptions for Scheduled Sampling and Analysis during 2024-North Anna Location Description Date of Sampling Reason( s) for Loss/Exception 14B,15,16,23,26 Vegetation 01/10/24 Seasonal unavailability 14B,15,16,23,26 Vegetation 02/14/24 Seasonal unavailability 14B,15,16,23,26 Vegetation 03/12/24 Seasonal unavailability ESE-12, NW-30,NW-62, TLD 10/02/24 Missing TLD's unable to collect EPSF-04 14B,15,16,23,26 Vegetation 11/13/24 Seasonal unavailability 14B,15,16,23,26 Vegetation 12/10/24 Seasonal unavailability 63

REFERENCES Dominion, North Anna Power Station Technical Specifications, Units 1 and 2. Dominion, North Anna Power Station Independent Spent Fuel Storage Installation Technical Specifications. Dominion, Station Administrative Procedure, VPAP-2103N, "Offsite Dose Calculation Manual". Virginia Electric and Power Company, North Anna Technical Procedure, HP-3051.010, "Radiological Environmental Monitoring Program". Title 10 Code of Federal Regulation, Part 50 (10CFR50), "Domestic Licensing of Production and Utilization Facilities". United States Nuclear Regulatory Commission Regulatory Guide 1.109, Rev. 1, "Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 1 0CFR50, Appendix I", October, 1977. United States Nuclear Regulatory Commission, Regulatory Guide 4.8 "Environmental Technical Specifications for Nuclear Power Plants", December 1975. USNRC Branch Technical Position, "Acceptable Radiological Environmental Monitoring Program", Rev. 1, November 1979. NUREG 0472, "Radiological Effluent Technical Specifications for PWRs", Rev. 3, March 1982. HASL-300, Environmental Measurements Laboratory, "EML Procedures Manual," 27th Edition, Volume 1, February 1992. NUREG/CR-4007, "Lower Limit of Detection: Definition and Elaboration of a Proposed Position for Radiological Effluent and Environmental Measurements," September 1984. 64

APPENDICES 65

Direction Distance (miles) Nearest Site Boundary N 0.87 NNE 0.85 NE 0.82 ENE 0.81 E 0.83 ESE 0.85 SE 0.88 SSE 0.91 s 0.94 SSW 1.01 SW 1.06 WSW 1.09 w 1.06 WNW 1.02 NW 0.97 NNW 0.90 APPENDIX A: LAND USE CENSUS Year 2024 LAND USE CENSUS North Anna Power Station Louisa County, Virginia January 1 to December 31, 2024 Nearest Nearest Resident Garden(> 50m2) 1.3 2.75 0.9 3.25 0.9 1.6 2.37 2.43 1.25 2.05 1.53 1.7 1.4 1.9 1.0 2.66 1.03 1.48 1.11 2.00 1.56 2.16 1.62 2.26 1.41 1.96 1.1 1.56 0.98 1.09 1.0 1.33 66 Nearest Nearest Nearest Meat Milch Milch Animal Cow Goat NONE NONE NONE 1.6 NONE NONE 1.6 NONE NONE 2.49 NONE NONE 3.5 NONE NONE NONE NONE NONE 1.4 NONE NONE 1.6 NONE NONE 2.0 NONE NONE 2.0 NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE NONE

2023 to 2024 Land Use Census Changes 2023 2024 Nearest Direction Distance Distance Resident W 1.50 1.41 Site Boundary NONE Garden ENE WNW Meat Animal NNW Milch Cow Milch Goat All listed distances are in miles NONE NONE 2.40 2.05 2.30 67 2.43 1.56 NONE

2024 Summary of Results - Inter-laboratory Comparison Program {ICP) The Teledyne Brown Engineering Environmental Services (TBE-ES) laboratory analyzed Performance Evaluation (PE) samples of air particulate (AP), milk, soil, vegetation, and water matrices that represent test and matrix combinations available for REMP programs. The PE samples supplied by Eckert & Ziegler (E&Z) Analytics Inc., Environmental Resource Associates (ERA), and Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP), were evaluated against the following pre-set acceptance criteria: A. E&Z Analytics Evaluation Criteria Analytics' evaluation report provides a ratio of TBE's result and E&Z Analytics' known value. Since flag values are not assigned by E&Z Analytics, TBE evaluates the reported ratios based on internal QC requirements based on the DOE MAPEP criteria.

1.

A= Acceptable - reported result falls within ratio limits of 0.80-1.20

2.

W = Acceptable with warning - reported result falls within 0.70-0.80 or 1.20-1.30

3.

N = Not Acceptable - reported result falls outside the ratio limits of< 0.70 and> 1.30 B. ERA Evaluation Criteria ERA's evaluation report provides an acceptance range for control and warning limits with associated flag values. ERA's acceptance limits are established per the US EPA, National Environmental Laboratory Accreditation Conference (NELAC), state-specific Performance Testing (PT) program requirements or ERA's SOP for the Generation of Performance Acceptance Limits, as applicable. The acceptance limits are either determined by a regression equation specific to each analyte or a fixed percentage limit promulgated under the appropriate regulatory document.

1.

A= Acceptable - Reported value falls within the Acceptance Limits

2.

N = Not Acceptable - Reported value falls outside of the Acceptance Limits C. DOE Evaluation Criteria MAPEP's evaluation report provides an acceptance range with associated flag values. MAPEP defines three levels of performance:

1.

Acceptable (flag= "A") - result within+/- 20% of the reference value

2.

Acceptable with Warning (flag= "W") - result falls in the+/- 20% to+/- 30% of the reference value

3.

Not Acceptable (flag= "N") - bias is greater than 30% of the reference value Note: The Department of Energy (DOE} Mixed Analyte Performance Evaluation Program (MAPEP) samples are created to mimic conditions found at DOE sites which do not always resemble typical environmental samples obtained at commercial nuclear power facilities. 68

The Inter-Laboratory Comparison Program provides evidence of "in control" counting systems and methods, and that the laboratories are producing accurate and reliable data. 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: A. 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. B. 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. C. 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-231 to better reflect client sample testing and acceptable results were achieved. Acceptable results returned in a later sample study, supporting effectiveness of corrective action. D. NCR 24-06: E&Z Analytics March E14092 air particulate study Co-60 evaluated as "Not Acceptable." TBE reported 168 pCi and the known value returned at 126 pCi. Additionally, March E14093 soil Ce-141 evaluated as "Not Acceptable." TBE reported 0.106pCi/g and the known value returned at 0.071pCi/g. The root cause investigation was unable to determine any anomaly thus no proposed corrective action. No recurrence has occurred. E. CAR 24-02 (CAR 23-31 ): MAPEP February 24-MaS50 soil study Fe-55 evaluated as "Not Acceptable." TBE reported 297 Bq/Kg and the known value returned at 650 Bq/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. F. NCR 24-08: MAPEP February 24-MaS50 soil study Ni-63 evaluated as "Not Acceptable." TBE reported 1070 Bq/Kg and the known value returned at 1530 Bq/Kb (range 1071-1989). The root cause investigation suspected that the sample contained added interferences that are not typically 69

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 ofNi-59 tracer to determine yield results when calculating results. TBE analytical procedure TBE-2013 was updated to include this change. G. 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. H. NCR 24-10: MAPEP February 24-MaW50 water study Tc-99 evaluated as "Not Acceptable." TBE reported 9.95Bq/L and the known value returned 7.47Bq/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. I. NCR 24-11: MAPEP February 24-RdV50 vegetation study Sr-90 evaluated as "Not Acceptable." TBE reported 0.276Bq/sample and the known value returned 0.529Bq/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. J. NCR 24-14: ERA September MRAD-41 air particulate study U-234/238 evaluated as "Not Acceptable." TBE reported 14.0/14.2 pCi/filter and the known value returned at 31.1/30.9 pCi/filter (range 23.1-36.9). The root cause investigation determined that the laboratory technician placed double the amount of tracer in the sample by error. To correct and prevent recurrence, samples that have been digested/leached with carrier/tracer added will have a label placed over the cap indicating it has already been added. Additionally, the beaker that aliquot is put in should have markings to indicate carrier/tracer has already been added to the sample. K. 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. L. NCR 24-16: MAPEP August 24-MaS51 soil study Fe-55 evaluated as "Not Acceptable." TBE did not report a value and the known value returned 780Bq/Kg (range 546-1014). The root cause is still under investigation. M. NCR 24-17: MAPEP August 24-RdV51 vegetation study Sr-90 evaluated as "Not Acceptable." TBE reported 0.95Bq/sample and the known value returned 2.39Bq/sample (range 1.67-3.11). The root cause is still under investigation. 70

A.1 Analytics Enviro:nma111tal Radioactivity Cross Check f:rog :am Taledl!;!a Brown Engineering Environmental Services clenl!i,ca'licln TBE KiritiWfl Ratio or TBE ro Motilthi'Yea:t Matrix Nuciide Units Repatl.ed l Nl.llil'.ll>er Value~ Analytics ResL.111 Evaluation Value tMau;h2024 E 4089 M i Sr-891 pCi,'l. 19.6 78.2 1.112 A Sr-90 pCill 2.6 11.9 1.06 A E14CD9D !Mi~ iCa-14'il pCiJL 75.fi 85.0 0.89 A Co-58 pCiJl. -0.mm Not MeawreQ C'.J>fi[) pCill 139 158 0.88 A Ot-51 pCill 2 2 23@ 0.92 A Cs-134 pCiJl.. 1157 n1a 0.84 A Cs-137 pCiJl. 'i158 171 0.93 A Fe-59 pCiJL a.1 .86.5 0.941 A 1- 'i1 31 pCi,tL 80.9 90.8 0.8'9 A Ml'l-54 pC~IL 173 183 0.95 A Ztl-00 pOill 165 176 0.93 A E14091 Ohah'.Xla'I m-131 pCi 90.1 '90.3 1.00 A E14092 AP Ce-'i141 pCi 6fU 61.5 1.01 A Co-58 pCi 1.73 Ndt.leaSl.l d Co-60 pCi 'i168 126 cw N~ Ot-51 pCi 182 183 0.99 A Cs- ::W

pCi,

'i157 157 um A Os-137 pCi 'il32 136.C!J 0JJ7 A Fe-59 pCi 71lt.3 68.6, 1.02 A Mn:-54 pCi 1144 145 0.99 A Zr'I-Bi5 pCi 125 140 0.89 A E14Cll93 Sciil iCa-141 pOilg

0. Hl6 QU 1.48 N f,IJ Co-68 pCilg

-[ltJlJ[lt5 Ndt Mei:li:IUradl ~o pCi.rg IDL 21 0.13.3 0.91 A Ot-5'il pCi,rg

0. '98 0.194

'il.02 A Cs-1::W pCilg 0,_2}1Jfi 0.100 'il.24 'MV Os-137 pCilg 0.207 0..2[19 0.99 A Fe-59 pCilg OJIIB3 0..073 0.87 A (Mr1-54 pCi,r!J D. (II

0. 153 0.91 A

Zll--fii!ii pOilg 0.1 9 0148 1.01 A E14094 AP Sr-8'9 pCi 83.9 90.18, 0Jl3 A Sr-9D pCi 11.7 13.B 0.85 A Septs er 2024 E149.5 Milt Sr-8'9 pCill 188-Cl 92.3 0.95 A Sr-00 pCi.lL 12.4 152 0.82 A E14096 Mill. Ce-14'il pOiJL 12, 124 1.0D A Co-58 pCi.rL 'i154 1-5([) 1.03 A Co-60 pCi,lL 232 236 0.98 A 71

A.1 Analytics Environmental Radioactivity Cross Check Pmgll'arm Teledyne* Brown Eng1mierimp Environmemtal Services ldemti5ta1ion TBE KlfiOWI'I Ratia of TIBE 11:0 Morillh/Year INLmibet f.latti:X. Nuclide Units Reported Value (a) Analytics Result 'Value Ot-51 pOi,ll. 2B4 274 UM Cs-134 pOiJlL 180.0 187 0.98 Cs-137 pOi.rll.. 126 127 0.99 Fe-59 pCi.it. 127.0 113 1.12 1-131 pOi.it. 8!L3 M.O 0.98 Ml'l-54 pCiJlL 162 162 1.00 Zii-65 pCi,ll. 294 275 1.07 E14{]J97 OhahXla'l ~-131 pOi 98.B '92.6 1.07 E14098 AP 08-~41 pCi 82.0 76..7 1.07 Co-SB pOi QU!l '9Q.6 0.98 Co-60 pCi 180 146 1.23 Ot-51 pCi 208 170 1.22. iOs-134 pCi 1 6 116 1.0D Cs-137 pCi. 83.1 78.'9 1.1)5 Fe-59 pCi 75.6 702 1.08 !Mn-54 pOt 101 100 1.01 Zn-00 pCi 167 170 0.98 E14099 ScJI Ce--141 pCiig 0..224 0.222 1.m Co-58 pCilg 0.249 0.2~ 0.93 Co-60 pCitg 0.420 0.423 0.99 Ot-51 pCitg 0.4'92 0.492 1.0D Cs-1:W pCi.r!J 0..278 0.336 0.83 Cs-137 pCi.rg 0.276 0.295 0.94 Fe-§9 pCitg 0.233 0.2CM 1.14 !Mh--5!1. pCi.lE!I 0.279 0.200 0.96 Zn-E!6 pCi.t'g 0.538 0.494 1.09 E 1410, AP Sr-BQI pOi 79.5 82.7 0.96 Sr-00 pCi 12.Cll

13J3, 0.88 E14197 Liquid iGr-A £Arn241 J, pOi,llL 47.6.

5@.1 0Jl5 Gr-B (06137} pCi,llL 2.48 270 0.92

ej TheAna.lyt.lcsA'.liVl!in Wl'r.leJ.s equ,al'i!'O 1~ dltlep.!n~piese,!ilt1!ll ~oSl!Brildsml es: de!~bygrBJi ~

• c.Bl'ildlar ll't]l'rJme\\!r;i'c ffll!!8S!l\\!l\\'alM1S made, !lii;.\\!i\\li'g stsndaml Jltl'ep.srml'fl.D

~ j ~ elti3fuafi\\on based oo TSE.L'r.tl'a:rlal QC ~ !l'lll'B:- A ~Aooepta.t.\\\\e-.repartedliE!sw'tlal\\s !ll1'thln raAb!frim~s:Jlllfill.BG-1..211!1 W.,;;, Accsprab\\e wJth WBtilll~ - i!'cJ!Orted m~i.t fall's ~\\\\tt.uril 0.1C-0.6tl' c,.r 1.Z0.-1.3/J 'N - Net.lloceptabie - tepart:ed reS'lll\\i.t mD's !lilJJf.sicle tl\\Je,ratib 1l'm'ts of<- rO.. 7G tmd. ;, 'J...30 72 Ewluaooh,ii A. A A A A A A A A A ?N,.,, A .A A A A A A A A A A A A A A A A

A2 DOE's Mixed Amalyte Performance Evaluation Program (MAPEP) Teledymt Brown Engineer1ing En,vironm lal Services mctentifiicatiOn TEE Know.n A.coeplancs Monlh!Y,ear Numbet Maltix Nuclide Units Reported Valw('ll Ri:llige E:.valualian I.bl Value February 2024 24-Ma$5(]) Soil Fe-55 Bqlkg 297 1658 455-845

NlJ, Ni-63 Bct'kg 1070 1530 1071 - 1'989

~,, Tc-'99 Bqlkg 3:25 336

235-437 A

lb-22B Bg,lkg 34_6 48.8 34.2-63.4 w Th-23(]) B!Jk~ 49.7 54.0 38.0-70.0 A Th-232 Bc)'k§ 36.4 45.1 31.6-58.6 A 24..IMa.SUIOO Urine Cs-134 IBqfL 1.12 1.36 0Jlt5-1.77 A Cs--137 IBqi\\L 200 2.23 1.56-2.90 A Co-57 1Bq11L UJ6 L26 0.88-1.64, A Co-60 Bql'L

2.26 238 Uii7-3.09 A

K-40

Bql\\L

-1.M Mr'l-54 IBqt'L U4 1.51 U)5-1.'96 A U-234 Bql'L 0_00101 (1J A U-238 ~iL 0.00228 (1J A Zn-55 IBqi\\L --0.42 0.84 0.5111-.00 NErs~ 24-,Ma.wm Water Ni-63 1Bq1\\L 0.338 O.BiD (2} A To-'99 1Bq1'L 9.95

7. 7 5.23-9.71 I&~

24-R!:IVOO 'Vegetation Cs-134 B[Jl'$illmpfe 2e@ 3.67 257-4.71 w Cs-137 B~mple 2-21 257 U~D-3.34 A Co-57 B~mple 2.221 25'3 1.77-3.29 A Co-60 B~rnpls 242 200 20'7-3115 A Mo-54 Bqls;ample 0.033 (1J A .Sr-90 Bq,sarnple 0.276 O.!!ml 0.370-UISB Nf111 Zr'l-55 Bql':!iarniJle fl,J!,3 8.02 5.6 - 10..43 A Aagust2024 24..J,laS51 Soil Fe-5.5 BqlkQ {BJ 780 546-Ul14 l!Jt, Ni-63 B~ 1140..(])0 50.00 1U15-1,885 w lG-00 B~ 155.£10 171.100 12D-222 A Th-2213 B )kg 38.00 43.30 31J.lL3-55.3 A lb-230 B~fkg 4fUO -44.00 3@..8 - fu.2 A Th-2:32 B~ 38.191D 2.60

2S!l.B-55.

A 24..IMa\\1!151 Water Ni-53 IBqi'L 0.60 ('1} A Tc-00 Bql'l. 11.'9(11 11.20 7.8-1-4.6 A 24-Rr1V5~ Vegela*too Cs-134 B[llsarnpls 3.12

2~89 202-3.76 A

Cs-137 Bql'sarnple 2.18 1.91 C:W-2.48 A Co-57 Bq)'san,ple 0.00 (1J A Co-60 B~rnple 2~24 201

1. 1 - 2.61 A

Mr.-54 BqtsarmpJ.e 3.76 3.53 247-4.59 A Sr-00 Bql'san,ple 0.95 239 1.67-3.n r,ialtCJr Zn-615 Bqi'sarnple UJ.30 9.13 1fL39 - 11.87 A 73

{:sJ rfie UAPEP.kr:lawn VBl\\:re is eql!lsJ lD 1,00% cf thE-parametel"Fif!serJt ft:i* tbe standard as di!.'tell'lJffle.ri b!f' gral/NJJeJlic Elfldlor ~mi:m'c measWiM'Jen! m-arie dur:f!:Jg standsrri p.fEf'PS.t'atk"Jn tt,j OCYEMAPEP e\\\\Bl'blBfl'cm*: A,. Acceptsb'e - repatted illeSl.lff taPs 11titl\\uril rat.lo Jlm:i't5: of C..8(H.26 IW ~ Act:eplab.'e 11t.ith I.\\ISlnV?g-n;pai'ted IIE:'Sll\\\\f (aQ'.s w.\\!twil (J_ 1().f)_B(J tN' 1.~1.3.fJ t~ /!id Ac.CEp~'e - ff!/J{Jfted.restl\\lt fall's.o.r.ir&rte the rel\\~ /Jm'ts of"'-(HO Fdl'd ;;. 11.::30' m F-etBce pos,.'11i;e tesl {'2J Sel'J~ill ~ e,mhl*.!i'bbn (3; See CA'R. 23..311 " ' See N:CR '.24,48 f:5} 'hlat Evel'uared, ra-reporsed BB Fa1st Poe, by 1.M.'P'EP '6.~ See t.l:CR 24,;10 f/1J See NCR:24 *11 74

A.3 ERA Emvirorumm.tal RadJoactMty Cr,oss 1Ch ck Program Teledyne Brown Engineering Environmental Services MonthlYaat ldentit'icalian Malri:x. Nuclide lllmls "flBE Reported Known A.cceplance Evaluation Cbl Number Value Value fa) Limits !March.2024 MRAD-40 Water Am-241 pCi/L 101 139 95.-4-178 A Fe-55 pCilL 2185 24BO 1-fflO-3610 A flu-238 pCllL 162~0 70.,4, -42.3, - 91.2 A P1.t-:239 pCif,L 6L2 76.5 47.3 - 94.J A Seil Am-2-41 pCi/kg NR ~880 1020-2660 PLJ-238 pCilkg 667 512 255 - 778 A Pu-239 pCi/kg 562 54.5 297 - 784 A Sr-'90 pCi/kg 4050 3830 1130 - 5650 A U-234 pCi/kg 3040 4360 20,40 - 5710 A U-238 pCill<g 3270 4320 2370 - 5800 A AP Alili-24-~ pOitliilter 3.8.B 55.0 39.3 - 73.3 Nr*~ Fe--55 pOilfilter 387 386 141 - 616 A Pu-238 pCuf~lter 4.5.9 41.1 31.0 - 50.5 A Pu-239 pCi/l\\ilter 54.9 56,.1 41.9 - 67.7 A U-234 pOilliilter 11.1 11.6 8.60 - 13.6 A l!J-238 pC'i.lWtet 12.B 11.5 B.6B - 13.7 A GR-A i;>Oitftilfet 116 9.5.9 50.1-158 A GR-8 pO_il~ill.er 2.1 22.2 13..5 - 33.5 Nf2~ ApJi l 2024 RAD-137 Wah:lr Ba-133 pOil\\L ~B 65.9 5(U - 81.7 A c.,;..134 pC-1/L 51.0 57.B 42.8 - 728 A Cs-*1.37 pOilL 153 186 149 - 223 .A Co-00 pCilL 921 98.8 79.7-118 A Zn:-65 p()i/L 208 20 188-292 A GR-A pOilL 3.5.2 52.6 39.6 - 65.6 N~6 GR-B pOitL 49 46.5 33.9 - 59.1 A U-Nal pOilL 00.0 59.3 52..&-f!5..8 A H-3 pC:itL 19,000 21.300 18,200 - 24.400 A St-39 [POiiL -4&9 52'..2 37.8 - 66.6 A Sr-9@ pCi!L 32.6 37.iB 32.0 - 43.2 A i-131 pOli'L 21.8 2.5.1 21.7 - 28.5 A SeJ11l:em.M r 2024 MRAD-41 Wat.er Am-2 1 pCil\\L 108.0 117.0 B0.3-150 A Fe--55 pCil'L 6l5 1230 723-1700 Nf4~ Pu-238 pCil\\L 99 103 6 1.9-133 A Pu-239 pCi/L 123 133 82.3-164 A Sail M -241 pCilkg 132@ 1110 599-1570 A flu-238 pCilkg 1380 1mm 928-28:ro A Pu-239 pCilkg 7,95 1030 §.61-1480 A

Sr-'90 pCilkg 3240 4730 1470-7370 A

75

lJJ-,234 pCi/l<g 2540 2860 1340-3750 l!l-238 pCi/l<g 23'90 2840 1560-3810 AP Arn-241 pOilfiilfet 27.0 29.1 20.8-38.8 Fe-55 pO.ilimer 64A 800 292-1280 Pu-238 pOilMtet 22_3 21.5 16.2-26.4 Pu-239 pD.ttfiilter 30.6 32~4 24.2-39.. 1 U-234 pOUl\\ilter 14.0 31.1 23.1 -36.4 U-238 pO.i/1\\iller 14-2 30.9 23.3--36J~ GR-A pOilliilfer 80.0 72_4 37..8-119 GR-B pOilfiilter 57.5 47.9 29.0-7.2.4 Oddber 2024 RAD-13'9< W.a'ter Ba-133 pCittl 30.3

27.

15.5-39.3 0&--134 pOUL 73.3 80.2 63.0-97.4 Cs-:137 pOiiiL 46,.6 46.3 23.3-69.3 Co-00 pCciiL 442 45.J 31.6-59.0 Zn-65 pCi~L 104 114.0 75.0-153 GR-A pCillL 47J6 51.7 38.9-64,.5 GR-8

• O.ii'L

-44.. 2 ,48.1 35.2-61.0 U-N:al pOUL .28.3 26.00 23.6-30.2 H-3 pOil'L 4,690 5,320 3870-6770 St...SS [j)Cii'L 57.5 44.2 30.6-57.8 St-'90 pOu'L 37.3 35.6 30.2-41.0 0-131 pO.irL 28.3 26.3 22.7-29.Q (s} The ERA lknawn value J.!I equal. il'D 100 af the peramete.rpr;e.!ie.l'Jt oo* i!he srandard as de&ermmed tiy graP,'/meJlic al'Jdibr vaJumetrlc

m1aE1~!B1'1M?.!!\\!S made dum;g staJ\\\\~ preparation..

{b} ERA e1,,..al'uar, r.r A

• AceepJal'lte - Repooed Wi\\\\u'E' fal\\\\9 within Ike Aoop1ance Lim!ls

,J Not.AIO!:epl'a.b.ie - ~ad ~-e fa,IJs DJ:lts,'de of tile Accept81'ilce LJrrn't.s 1} See NCR U02 (ij See NCR U~t>l (.3J See NCR ~05 (4J Sae NCRU1S 76 A A A A A A Nrs)

Nrs, A

A A A A A A A A A A A A A}}