0CAN052101, Annual Radiological Environmental Operating Report for 2020

Annual Radiological Environmental Operating Report for 2020

ML21133A017
Person / Time
Site:	Arkansas Nuclear
Issue date:	05/13/2021
From:	Keele R Entergy Operations
To:	Document Control Desk, Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation
References
0CAN052101
Download: ML21133A017 (66)

Text

0CAN052101 May 13, 2021 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555

SUBJECT:

Annual Radiological Environmental Operating Report for 2020 Arkansas Nuclear One - Units 1 and 2 NRC Docket Nos. 50-313, 50-368, and 72-13 Renewed Facility Operating License Nos. DPR-51 and NPF-6

Reference:

Entergy Operations, Inc. (Entergy) letter to NRC, Annual Radioactive Effluent Release Report for 2020, Arkansas Nuclear One, Units 1 and 2 (0CAN042102),

dated April 21, 2021 In accordance with Arkansas Nuclear One (ANO), Unit 1 Technical Specification (TS) 5.6.2 and Unit 2 TS 6.6.2, the submittal of an annual radiological environmental operating report for the previous year is required by May 15, of each year. The subject ANO report for the calendar year 2020, is enclosed. This report fulfills the reporting requirements of the referenced TSs.

The radionuclides detected by the radiological environmental monitoring program during 2020, were significantly below the regulatory limits. The operation of the ANO station during 2020, had no harmful radiological effects nor resulted in any irreversible damage to the local environment.

No environmental samples from the monitoring program equaled or exceeded the reporting levels for radioactivity concentration due to ANO effluents when averaged over any calendar quarter. A map of sampling locations and a corresponding table providing the respective distances and directions from the reactor containment building is included in the Offsite Dose Calculation Manual submitted as part of the referenced Annual Radioactive Effluent Release Report.

Riley D. Keele, Jr.

Manager, Regulatory Assurance Arkansas Nuclear One Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-7826

0CAN052101 Page 2 of 2 This letter contains no new commitments. If you have any questions or require additional information, please contact me.

Respectfully, ORIGINAL SIGNED BY RILEY D. KEELE, JR.

Riley D. Keele, Jr.

RDK/nbm

Enclosure:

Annual Radiological Environmental Operating Report for 2020 cc:

NRC Region IV Regional Administrator NRC Senior Resident Inspector - Arkansas Nuclear One NRC Project Manager - Arkansas Nuclear One Designated Arkansas State Official

Enclosure to 0CAN052101 Annual Radiological Environmental Operating Report for 2020

Plant: Arkansas Nuclear One Page 1 of 63 Year: 2020 Document Number: 0CAN052101 Annual Radiological Environmental Operating Report

Plant: Arkansas Nuclear One Year: 2020 Page 2 of 63 Annual Radiological Environmental Operating Report TABLE OF CONTENTS 1.0 EXECUTIVE

SUMMARY

.............................................................................................................. 3

2.0 INTRODUCTION

.......................................................................................................................... 5 3.0 RADIOLOGICAL ENVIRONMENTAL SAMPLING PROGRAM REQUIREMENTS...................... 6 4.0 INTERPRETATION AND TRENDS OF RESULTS..................................................................... 17 5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

.......................... 24 ATTACHMENTS - Sample Deviations......................................................................................................... 29 - Monitoring Results Tables.............................................................................................. 32 - Interlaboratory Comparison Program Results................................................................ 47 - Environmental Dosimetry Company Interlaboratory Comparison Program Report........ 50

Plant: Arkansas Nuclear One Year: 2020 Page 3 of 63 Annual Radiological Environmental Operating Report 1.0 EXECUTIVE

SUMMARY

1.1 Radiological Environmental Monitoring Program The Annual Radiological Environmental Operating Report presents data obtained through analyses of environmental samples collected for Arkansas Nuclear One (ANO) Radiological Environmental Monitoring Program (REMP) for the period January 1 through December 31, 2020. This report fulfills the requirements of Arkansas Nuclear One Unit 1 Technical Specification (TS) 5.6.2 and Unit 2 TS 6.6.2.

All required lower limit of detection (LLD) capabilities were achieved in all sample analyses during 2020, as required by the ANOs Offsite Dose Calculation Manual (ODCM). No measurable levels of radiation above baseline levels attributable to ANO operation were detected in the vicinity of ANO. The 2020 Radiological Environmental Monitoring Program thus substantiated the adequacy of source control and effluent monitoring at ANO with no observed impact of plant operations on the environment.

ANO established the REMP prior to the stations becoming operational (1974) to provide data on background radiation and radioactivity normally present in the area.

ANO has continued to monitor the environment by sampling air, water, sediment, fish, and food products, as well as measuring direct radiation. ANO also samples milk if milk-producing animals used for human consumption are present within five miles (8 km) of the plant.

The REMP includes sampling indicator and control locations within an approximate 20-mile radius of the plant. The REMP utilizes indicator locations near the site to show any increases or buildup of radioactivity that might occur due to station operation and control locations farther away from the site to indicate the presence of only naturally occurring radioactivity. ANO personnel compare indicator results with control and preoperational results to assess any impact ANO operation might have had on the surrounding environment.

In 2020, environmental samples were collected for radiological analysis. The results of indicator locations were compared with control locations and previous studies. It was concluded that no significant relationship exists between ANO operation and effect on the area around the plant. The review of 2020 data showed radioactivity levels in the environment were undetectable in many locations and near background levels in significant pathways.

1.2 Reporting Levels No samples equaled or exceeded reporting levels.

Plant: Arkansas Nuclear One Year: 2020 Page 4 of 63 Annual Radiological Environmental Operating Report 1.3 Comparison to State and/or Federal Program ANO personnel compared REMP data to state monitoring programs as results became available. Historically, the programs used for comparison have included the U.S. Nuclear Regulatory Commission (NRC) Thermoluminescent Dosimeter (TLD)

Direct Radiation Monitoring Network and the Arkansas Department of Health.

The NRC TLD Network Program was discontinued in 1998. Historically these results have compared to those from the ANO REMP. ANO TLD results continue to remain similar to the historical average and continue to verify that plant operation is not affecting the ambient radiation levels in the environment.

The Arkansas Department of Health and the ANO REMP entail similar radiological environmental monitoring program requirements. These programs include collecting air samples and splitting or sharing sample media such as water, sediment, and fish.

Both programs have obtained similar results over previous years.

1.4 Sample Deviations During 2020, environmental sampling was performed for eight (8) media types addressed in the ODCM and for direct radiation. A total of 291 samples of the 292 scheduled were obtained. Of the scheduled samples, 99.6% were collected and analyzed in accordance with the requirements specified in the ODCM. Attachment 1 contains the listing of sample deviations and actions taken.

1.5 Program Modifications Changes made to ANO REMP Procedure EN-CY-130-01.

Throughout Section 7.0 - Updated procedure in order to use new air sample stations, this includes units or measure, calibration process, and new steps for operation and sampling.

- Moved the TLD 137 location from the speed limit sign on Arkansas Highway 28 to a utility pole on the front lawn of the Morris R. Moore Arkansas National Guard Armory.

Changes made to ANO ODCM:

(Table 4-1, Page 37) Moved the TLD 137 location from the speed limit sign on Arkansas Highway 28 to a utility pole on the front lawn of the Morris R. Moore Arkansas National Guard Armory.

Plant: Arkansas Nuclear One Year: 2020 Page 5 of 63 Annual Radiological Environmental Operating Report

2.0 INTRODUCTION

2.1 Radiological Environmental Monitoring Program ANO established the REMP to ensure that plant operating controls properly function to minimize any associated radiation endangerment to human health or the environment. The REMP is designed for:

Analyzing applicable pathways for anticipated types and quantities of radionuclides released into the environment.

Considering the possibility of a buildup of long-lived radionuclides in the environment and identifying physical and biological accumulations that may contribute to human exposures.

Considering the potential radiation exposure to plant and animal life in the environment surrounding ANO.

Correlating levels of radiation and radioactivity in the environment with radioactive releases from station operation.

2.2 Pathways Monitored The airborne, direct radiation, waterborne and ingestion pathways are monitored as required by ANO ODCM. A description of the REMP utilized to monitor the exposure pathways is described in the attached Tables and Figures.

Section 4.0 of this report provides a discussion of 2020 sampling results with Section 5.0 providing a summary of results for the monitored exposure pathways.

2.3 Land Use Census ANO conducts a land use census biennially, as required by Section B 2.5.2 of the ODCM. The purpose of this census is to identify changes in uses of land within five miles of ANO that would require modifications to the REMP and the ODCM. The most important criteria during this census are to determine the location of the nearest milk animal, the nearest residence, and the nearest garden of greater than 500 ft2 producing fresh leafy vegetables in each of the 16 meteorological sectors within a 5 mile distance from one reactor (containment).

Plant: Arkansas Nuclear One Year: 2020 Page 6 of 63 Annual Radiological Environmental Operating Report 3.0 RADIOLOGICAL ENVIRONMENTAL SAMPLING PROGRAM REQUIREMENTS Table 1, Exposure Pathway - Airborne Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses RADIOIODINE AND PARTICULATES 3 samples close to the Site Boundary, in (or near) different sectors with the highest calculated annual average ground level D/Q.

Station 2 (243° - 0.5 miles) -

South of the sewage treatment plant.

Station 56 (264° - 0.4 miles) -

West end of the sewage treatment plant.

Station 1 (88° - 0.5 miles) - Near the meteorology tower.

Continuous sampler operation with sample collection every two weeks, or more frequently if required by dust loading.

Radioiodine Canisters - I-131 analysis every two weeks.

Air Particulate - Gross beta radioactivity analysis following filter change.

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

Station 6 (111° - 6.8 miles) -

Local Entergy office, 305 South Knoxville Avenue, Russellville Continuous sampler operation with sample collection every two weeks, or more frequently if required by dust loading.

Radioiodine Canisters - I-131 analysis every two weeks.

Air Particulate - Gross beta radioactivity analysis following filter change.

RADIOIODINE AND PARTICULATES 1 sample from a control location, as for example 15 - 30 km distance and in the least prevalent wind direction.

Station 7 (210° - 19.0 miles) -

Entergy Supply Yard on Highway 10 in Danville. (Control)

Continuous sampler operation with sample collection every two weeks, or more frequently if required by dust loading.

Radioiodine Canisters - I-131 analysis every two weeks.

Air Particulate - Gross beta radioactivity analysis following filter change.

Plant: Arkansas Nuclear One Year: 2020 Page 7 of 63 Annual Radiological Environmental Operating Report Table 2, Exposure Pathway - Direct Radiation Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses TLDS 16 inner ring stations with two or more dosimeters in each meteorological sector in the general area of the site boundary.

Station 1 (88° - 0.5 miles) - On a pole near the meteorology tower.

Station 2 (243° - 0.5 miles) - South of the sewage treatment plant.

Station 3 (5 - 0.7 miles) - West of ANO Gate #2 on Highway 333 (approximately 0.35 miles)

Station 4 (181° - 0.5 miles) - West of May Cemetery entrance on south side of the road.

Station 56 (264° - 0.4 miles) - West end of the sewage treatment plant.

Station 108 (306° - 0.9 miles) - South on Flatwood Road on a utility pole.

Station 109 (291° - 0.6 miles) - Utility pole across from the junction of Flatwood Road and Round Mountain Road.

Station 110 (138° - 0.8 miles) -

Bunker Hill Lane on the first utility pole on the left.

Station 145 (28° - 0.6 miles) - Near west entrance to the RERTC on a utility pole.

Once per 92 days.

mR exposure quarterly.

Plant: Arkansas Nuclear One Year: 2020 Page 8 of 63 Annual Radiological Environmental Operating Report Table 2, Exposure Pathway - Direct Radiation Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses TLDS 16 inner ring stations with two or more dosimeters in each meteorological sector in the general area of the site boundary.

Station 146 (45° - 0.6 miles) - South end of east parking lot at RERTC on a utility pole.

Station 147 (61° - 0.6 miles) - West side of Bunker Hill Road, approximately 100 yards from intersection with State Highway 333.

Station 148 (122° - 0.6 miles) -

Intersection of Bunker Hill Road with Scott Lane on county road sign post.

Station 149 (156° - 0.5 miles) - On a utility pole on the south side of May Road.

Station 150 (205° - 0.6 miles) - North side of May Road on a utility pole past the McCurley Place turn.

Station 151 (225° - 0.4 miles) - West side of sewage treatment plant near the lake on a metal post.

Station 152 (338° - 0.8 miles) - South side of State Highway 333 on a road sign post.

Once per 92 days.

mR exposure quarterly.

Plant: Arkansas Nuclear One Year: 2020 Page 9 of 63 Annual Radiological Environmental Operating Report Table 2, Exposure Pathway - Direct Radiation Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses TLDS 8 stations with two or more dosimeters in special interest areas such as population centers, nearby residences, schools, and in 1 -

2 areas to serve as control locations.

Station 6 (111° - 6.8 miles) - Entergy local office in Russellville (305 South Knoxville Avenue).

Station 7 (210° - 19.0 miles) -

Entergy Supply Yard on Highway 10 in Danville.

Station 111 (120° - 2.0 miles) -

Marina Road on a utility pole on the left just prior to curve.

Station 116 (318° - 1.8 miles) -

Highway 333 and Highway 64 in London on a utility pole north of the railroad tracks.

Station 125 (46° - 8.7 miles) - College Street on a utility pole at the southeast corner of the red brick school building.

Station 127 (100° - 5.2 miles) -

Arkansas Tech Campus on a utility pole across from Paine Hall.

Station 137 (151° - 8.2 miles) - On a speed limit sign on the right in front of the Morris R. Moore Arkansas National Guard Armory.

Station 153 (304° - 9.2 miles) -

Knoxville Elementary School near the school entrance gate on a utility pole.

Once per 92 days.

mR exposure quarterly.

Plant: Arkansas Nuclear One Year: 2020 Page 10 of 63 Annual Radiological Environmental Operating Report Table 3, Exposure Pathway - Waterborne Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses SURFACE WATER 1 indicator location (influenced by plant discharge) 1 control location (uninfluenced by plant discharge)

Station 8 (166° - 0.2 miles) - Plant discharge canal.

Station 10 (95° - 0.5 miles) - Plant intake canal.

Grab samples every 92 days.

Gamma isotopic analysis and tritium analysis quarterly.

Drinking Water 1 indicator location (influenced by plant discharge) 1 control location (uninfluenced by plant discharge)

Station 14 (70° - 5.1 miles) -

Russellville city water system from the Illinois Bayou.

Station 57 (208° - 19.5 miles) -

Danville public water supply treatment on Fifth Street.

Once per 92 days.

I-131, gross beta, gamma isotopic and tritium analyses once per 92 days.

GROUNDWATER a control location up gradient from the protected area 2 sample locations of Groundwater from indicator locations down gradient from the protected area.

Station 58 (GWM-1, 22° - 0.3 miles) -

North of Protected Area in Owner Control Area (OCA). West of Security North Check Point, east side of access road.

Station 62 (GWM-101, 34° - 0.5 miles) - North of Protected Area in OCA. East of outside receiving building.

Station 63 (GWM-103, 206° - 0.1 miles) - South of Protected area in OCA. North-east of Stator Rewind Bldg. near wood line.

Station 64 (GWM-13, 112° - 0.1 miles) - South of Oily Water Separator facility, northwest corner of U-2 Intake Structure. Inside Protected area.

Grab samples every 92 days.

Gamma isotopic, gross beta, and tritium analysis quarterly.

Plant: Arkansas Nuclear One Year: 2020 Page 11 of 63 Annual Radiological Environmental Operating Report Table 3, Exposure Pathway - Waterborne Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses SEDIMENT FROM SHORELINE 1 indicator location (influenced by plant discharge) 1 control location (uninfluenced by plant discharge)

Station 8 (243° - 0.9 miles) - Plant discharge canal.

Station 16 (287° - 5.5 miles) - Panther Bay on south side of Arkansas River across from mouth of Piney Creek.

Once per 365 days.

Gamma isotopic analysis annually.

Plant: Arkansas Nuclear One Year: 2020 Page 12 of 63 Annual Radiological Environmental Operating Report Table 4, Exposure Pathway - Ingestion Requirement Sample Point Description Distance and Direction Sampling and Collection Frequency Type and Frequency Of Analyses MILK If commercially available, 1 sample from milking animals within 8 km distant where doses are calculated to be greater than 1 mrem per year.

1 sample from milking animals at a control location 15 - 30 km distant when an indicator location exists.

Currently, no available milking animals within 5 miles of ANO.

Gamma isotopic and I-131 analyses once per 92 days.

Gamma isotopic and I-131 analyses once per 92 days.

FISH AND INVERTEBRATES 1 sample of a commercially and/or recreationally important species in vicinity of plant discharge area.

1 sample of similar species in area not influenced by plant discharge.

Station 8 (212° - 0.5 miles) - Plant discharge canal.

Station 16 (287° - 5.5 miles) - Panther Bay on south side of Arkansas River across from mouth of Piney Creek.

Once per 365 days.

Gamma isotopic analysis on edible portions annually FOOD PRODUCTS 1 sample of one type of broadleaf vegetation grown near the SITE BOUNDARY location of highest predicted annual average ground level D/Q if milk sampling is not performed.

1 sample of similar broadleaf vegetation grown 15 - 30 km distant, if milk sampling is not performed.

Station 13 (273° - 0.5 miles) - West from ANO toward Gate 4 onto Flatwood Road.

Station 55 (217° - 13.1 miles) - Ozark National Forest north of Danville Three per 365 days.

Gamma. isotopic and I-131 analyses three times per 365 days

Plant: Arkansas Nuclear One Year: 2020 Page 13 of 63 Annual Radiological Environmental Operating Report Figure 1, Exposure Pathway

Plant: Arkansas Nuclear One Year: 2020 Page 14 of 63 Annual Radiological Environmental Operating Report Figure 2, Sample Collection Sites -Near Field Lake Dardanelle Arkansas Nuclear One REMP Sample Locations (Near Field)

Revised 24May05 West Access Rd.

Cemetery May Rd.

Bunker Hill Rd.

Bunker Hill Ln.

Scott Ln.

Training Center SR 333 150 4

149 8S 110 148 8C 36 56 2

13 109 10 1

147 146 145 108 152 3

151

Plant: Arkansas Nuclear One Year: 2020 Page 15 of 63 Annual Radiological Environmental Operating Report Figure 3, Sample Collection Sites - Far Field

Plant: Arkansas Nuclear One Year: 2020 Page 16 of 63 Annual Radiological Environmental Operating Report Figure 4, Sample Collection Sites -

Plant: Arkansas Nuclear One Year: 2020 Page 17 of 63 Annual Radiological Environmental Operating Report 4.0 INTERPRETATION AND TRENDS OF RESULTS 4.1 Air Particulate and Radioiodine Sample Results - Example The REMP has detected radioactivity in the airborne pathway attributable to other sources. These include the 25th Chinese nuclear test explosion in 1980, the radioactive plume release due to reactor core degradation at Chernobyl Nuclear Power Plant in 1986, and the Fukushima Daiichi Nuclear Power Plant accident (March 11, 2011).

In 2020 there were no samples above the LLD for I-131. Indicator gross beta air particulate results for 2020 were comparable to results obtained from 2010-2019 of the operational REMP, but less than 2013 when the annual average was 0.043. Also, the 2020 gross beta annual average was less than the average for preoperational levels. Results are reported as annual average picocuries per cubic meter (pCi/m3).

Monitoring Period Result 2010 - 2019 (Minimum Value) 0.017 2020 Average Value 0.017 2010 - 2019 (Maximum Value) 0.043 Preoperational 0.050 In the absence of plant-related gamma radionuclides, gross beta activity is attributed to naturally occurring radionuclides. Table 9, Air Particulate Data Summary Table, includes gross beta concentrations and provides a comparison of the indicator and control means and ranges emphasizes the consistent trends seen in this pathway to support the presence of naturally occurring activity. Therefore, it can be concluded that the airborne pathway continues to be unaffected by ANO operations.

Plant: Arkansas Nuclear One Year: 2020 Page 18 of 63 Annual Radiological Environmental Operating Report 4.2 Thermoluminescent Dosimetry (TLD) Sample Results -Example ANO reports measured dose as net exposure (field reading less transit reading) normalized to 92 days and relies on comparison of the indicator locations to the control as a measure of plant impact. ANOs comparison of the inner ring and special interest area TLD results to the control, as seen in Table 5, Direct Radiation Annual Summary, identified no noticeable trend that would indicate that the ambient radiation levels are being affected by plant operations. In addition, the inner ring value of 7.6 millirem (mrem) shown in Table 5 for 2020 is within the historical bounds of 2010 -

2019 annual average results, which have ranged from 7.6 to 8.5 mrem. Overall, ANO concluded that the ambient radiation levels are not being affected by plant operations.

Table 5, Direct Radiation Annual Summary Year Inner Ring (mR/Qtr)

Special Interest (mR/Qtr)

Control Location (mR/Qtr) 2010 8.3 7.4 6.9 2011 8.5 7.6 6.9 2012 8.0 7.2 7.0 2013 8.3 7.6 6.8 2014 7.8 6.9 6.1 2015 7.6 6.9 6.1 2016 8.0 6.7 6.5 2017 8.2 7.2 6.7 2018 7.7 6.4 5.7 2019 7.7 6.9 6.9 2020 7.6 6.9 6.0 4.3 Waterborne Sample Results Analytical results for 2020 drinking water and ground water samples were similar to those reported in previous years. Gamma radionuclides analytical results for 2020 surface water samples were similar to those reported in previous years. Tritium in ANO surface water indicator samples continues to be detected, but at levels below those experienced in 2013 and below the ODCM-required LLD. These results are further explained below.

Plant: Arkansas Nuclear One Year: 2020 Page 19 of 63 Annual Radiological Environmental Operating Report 4.3.1 Surface Water Samples were collected and analyzed for gamma radionuclides and tritium. Gamma radionuclides were below detectable limits which is consistent with results seen in previous operational years. Tritium continues to be detected at the indicator location (Station 8) where previously monitored liquid radioactive effluent from the plant is periodically discharged in accordance with the regulatory criteria established in the ODCM and, for 2020, at levels considerably lower than the ODCM-required LLD of 3000 pCi/l. Furthermore, unlike the elevated tritium levels observed in 2013 attributable to particular plant events, no elevated levels attributable to particular events were observed in 2020. Results are reported as annual average pCi/l.

Monitoring Period Result 2010 - 2019 (Minimum Value) 427.0 2020 Value 707.0 2010 - 2019 (Maximum Value) 2940*

Preoperational 200.0

• Indicates value from 2013 ANO personnel have noted no definable increasing trends associated with the tritium levels at the discharge location. Levels detected during 2020 and previous operational years have been well below regulatory reporting limits. Therefore, the operation of ANO had no definable impact on this waterborne pathway during 2020 and levels of radionuclides remain similar to those obtained in previous operational years.

4.3.2 Drinking Water Samples were collected from two locations (indicator and control). Although ANO personnel utilize Station 14 (City of Russellville) as an indicator location due to the potential for the drinking water pathway to exist, the City of Russellville has not withdrawn water from Lake Dardanelle in the past several years.

Drinking water samples were analyzed for gross beta radionuclides, I-131, gamma radionuclides and tritium. Gamma radionuclides, gross beta radionuclides, I-131, and tritium concentrations were below the LLD limits at the indicator and control locations, which is consistent with the preoperational and operational years as shown below.

Results from 2020 are summarized in table below. Results are reported as annual average pCi/L. The indicator location has historically shown gross beta above MDC but less than LLD, while the control location is below MDC and LLD. However, in 2020 the fourth quarter sample at the indicator was 1.88 pCi/L. This is above MDC bus less than LLD. The first through third quarters 2020 samples were less than MDC and LLD. The value for Gross Beta at the control location in 2020 was 2.07 pCi/L.

Plant: Arkansas Nuclear One Year: 2020 Page 20 of 63 Annual Radiological Environmental Operating Report Radionuclide 2020 2019 2010 - 2018**

Preoperational Gross Beta 1.72 1.97*

2.37 2.0 Iodine-131

< LLD

< LLD

< LLD

< LLD Gamma

< LLD

< LLD

< LLD

< LLD Tritium

< LLD

< LLD

< LLD 200.0 Average for the control sample during 2019, gross beta was 1.97 pCi/L which is >MDC, but <LLD.

• • Average of the results from the years 2010-2018.

ANO personnel have noted no definable trends associated with drinking water results at the indicator location. Therefore, the operation of Arkansas Nuclear One had no definable impact on this waterborne pathway during 2020 and levels of radionuclides remain similar to those obtained in previous operational years.

4.3.3 Groundwater Samples were collected from four REMP locations (2 control, and 2 indicator locations). During 2011, ANO incorporated sixteen additional groundwater monitoring wells into the Groundwater Protection Initiative (GPI) site program. Sample data are compiled, organized and reviewed annually to:

Analyze for increasing or decreasing trends at individual sample points, wells or groups of wells.

Review the radionuclides detected to determine whether changes should be made to the analysis sites or sampling frequencies for each sampling location.

Evaluate the locations of radionuclides in ground water to determine if changes should be made to the sampling locations.

Review current investigation levels and determine if changes should be made.

Determine if any change to the ODCM is required.

Determine if a corrective action/remediation is required.

Groundwater samples from the four REMP locations were analyzed for tritium and gamma radionuclides. Tritium and gamma concentrations were below the LLD limits at all four locations. Listed below is a comparison of 2020 indicator results to past operational years. Results are reported as annual average pCi/l. REMP Groundwater data are captured in the table below. Arkansas Nuclear One operations had no significant impact on the environment or public by this waterborne pathway.

Radionuclide 2020 2010 - 2019 Iodine-131

< LLD

< LLD Gamma

< LLD

< LLD Tritium

< LLD

< LLD Gross Beta 3.18*

3.50**

Average for Indicator and control wells for 2020.

• • Only 2014-2019 gross beta data available for review as historical data. Value is historical average.

Plant: Arkansas Nuclear One Year: 2020 Page 21 of 63 Annual Radiological Environmental Operating Report 4.4 Soil Sample Results - Example Sediment samples were collected from two locations in 2020 and analyzed for gamma radionuclides. Listed below is a comparison of 2020 indicator results to the 2010 - 2019 operational years. ANO operations had no significant impact on the environment or public by this waterborne pathway. Results are reported as pCi/kg.

Monitoring Period Result 2010 - 2019 (Minimum Value) 65.55 2020 Value

<LLD 2010 - 2019 (Maximum Value) 661.0 Sediment samples were collected from two locations in 2020 and analyzed for gamma radionuclides. Although Cesium-137 has been detected in years prior to 2020, all gamma radionuclides from 2020 samples were below detectable limits.

These results are consistent with previous years results. Therefore, ANO operations had no significant impact on the environment or public by this waterborne pathway.

4.5 Ingestion Sample Results - Example 4.5.1 Milk Sample Results Milk samples were not collected during 2020 due to the unavailability of indicator locations within five miles of ANO.

4.5.2 Fish Sample Results Fish samples were collected from two locations and analyzed for gamma radionuclides. In 2020, gamma radionuclides were below detectable limits which are consistent with the preoperational monitoring period and operational results since 1997. Therefore, based on these measurements, ANO operations had no significant radiological impact upon the environment or public by this ingestion pathway.

4.5.3 Food Product Sample Results The REMP has detected radionuclides prior to 1990 that are attributable to other sources. These include the radioactive plume release due to reactor core degradation at Chernobyl Nuclear Power Plant in 1986 and atmospheric weapons testing.

In 2020, food product samples were collected when available from two locations and analyzed for Iodine-131 and gamma radionuclides. The 2020 levels remained undetectable, as has been the case in previous years. Therefore, based on these measurements, ANO operations had no significant radiological impact upon the environment or public by this ingestion pathway.

Plant: Arkansas Nuclear One Year: 2020 Page 22 of 63 Annual Radiological Environmental Operating Report 4.6 Land Use Census Results The latest land use census (performed in 2019) did not identify any new locations that yielded a calculated dose or dose commitment greater than those currently calculated Table 6, Land Use Census - [2019] Nearest Residence Within Five Miles.

One cattle farm was observed in the NNE sector. An interview with the owner was performed and he stated that the cattle were for breeding. ANO personnel chose not to perform a garden census in 2019, but instead to sample broadleaf vegetation which is allowed by ODCM Section L 2.5.2. As allowed by NRC Regulatory Guide 1.21, Revision 2, Section 3.2, broadleaf vegetation sampling in the meteorological sector (Sector 13) with a D/Q value within 10% of the sector with the highest D/Q (Sector 12) was performed.

Plant: Arkansas Nuclear One Year: 2020 Page 23 of 63 Annual Radiological Environmental Operating Report Table 6, Land Use Census - [2019] Nearest Residence Within Five Miles Sector Direction Range (Miles)

Comment Nearest Residence Garden Meat Nearest Milk Animal 1

N 0.9 N/A

>5

>5 None 2

NNE 1.3 N/A 2.8

>5 1

3 NE 0.9 N/A

>5

>5 None 4

ENE 0.8 N/A

>5

>5 None 5

E 0.8 N/A

>5

>5 None 6

ESE 0.8 N/A

>5

>5 None 7

SE 0.8 N/A

>5

>5 None 8

SSE 0.8 N/A

>5

>5 None 9

S 0.8 N/A

>5

>5 None 10 SSW 0.7 N/A

>5

>5 None 11 SW 2.8 N/A

>5

>5 None 12 WSW 0.7 N/A

>5

>5 None 13 W

0.8 N/A

>5

>5 None 14 WNW 0.8 N/A

>5

>5 None 15 NW 1.0 N/A

>5

>5 None 16 NNW 0.9 N/A

>5

>5 None Comment 1

While performing the LUC, a cattle farm was identified. A phone interview was performed with the owner of the farm. The owner stated the cattle were mainly for breeding purposes but could provide an animal for consumption. The meat pathway is not required per ANO ODCM.

Plant: Arkansas Nuclear One Year: 2020 Page 24 of 63 Annual Radiological Environmental Operating Report 4.7 Interlaboratory Comparison Results and Attachment 4 contains result summaries for Interlaboratory Comparison Program for Teledyne Brown Engineering and Environmental Dosimetry Group.

5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

1.

Table 7, Radiological Environmental Monitoring Program Summary, summarizes data for the 2020 REMP program.

Plant: Arkansas Nuclear One Year: 2020 Page 25 of 63 Annual Radiological Environmental Operating Report Table 7, Radiological Environmental Monitoring Program Summary Sample Type (Units)

Type / Number of Analyses

[Note 1]

LLD [Note 2]

Indicator Locations Mean (F)[Note 3]

[Range]

Location [Note 4] [Highest Annual Mean]

Control Locations Mean (F)[Note 3] [Range]

Number of Non-Routine Results [Note 5]

Location Mean (F)[Note 3]

[Range]

Air Particulates (pCi/m3)

GB / 130 0.01 0.0175(78 / 78)

[0.0166 - 0.0184]

Station 6 (88°,0.5 mi) 0.0192 (26 / 26)

[0.0103 - 0.0331]

0.0171 (52 / 52)

[0.0165 - 0.0192]

9 Airborne Iodine (pCi/ m3)

I-131 / 130 0.07

< LLD N/A N/A

< LLD 9

Inner Ring TLDs (mR/Qtr)

Special Interest TLDs (mR/Qtr)

Control TLD (mR/Qtr)

Gamma / 64 Gamma / 28 Gamma / 4

[Note 6]

[Note 6]

[Note 6]

7.6 (64 / 64)

[5.1 - 9.4]

6.9 (28 / 28)

[5.1 - 8.5]

N/A Station 56 (264°, 0.4 mi)

Station 116 (318° - 1.8 mi)

N/A 9.4 (4 / 4)

[8.3 - 11.2]

8.5 (4 / 4)

[8.1 - 9.1]

N/A N/A N/A 6.0 (4 / 4)

[5.3 - 6.9]

0 1

0

Plant: Arkansas Nuclear One Year: 2020 Page 26 of 63 Annual Radiological Environmental Operating Report Table 7, Radiological Environmental Monitoring Program Summary Sample Type (Units)

Type / Number of Analyses

[Note 1]

LLD [Note 2]

Indicator Locations Mean (F)[Note 3]

[Range]

Location [Note 4] [Highest Annual Mean]

Control Locations Mean (F)[Note 3] [Range]

Number of Non-Routine Results [Note 5]

Location Mean (F)[Note 3]

[Range]

Surface Water (pCi/l)

H-3 / 8 GS / 24 Mn-54 Fe-59 Co-58 Co-60 Zn-65 Zr-95 Nb-95 I-131 Cs-134 Cs-137 Ba-140 La-140 3000 15 30 15 15 30 30 15 15 15 18 60 15 707.0 (4 / 4)

[370 - 986]

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD Station 8 (166°,

0.2 mi)

N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 707.0 (4 / 4)

[370 - 986]

N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD 0

0 0

0 0

0 0

0 0

0 0

0 0

Plant: Arkansas Nuclear One Year: 2020 Page 27 of 63 Annual Radiological Environmental Operating Report Table 7, Radiological Environmental Monitoring Program Summary Sample Type (Units)

Type / Number of Analyses

[Note 1]

LLD [Note 2]

Indicator Locations Mean (F)[Note 3]

[Range]

Location [Note 4] [Highest Annual Mean]

Control Locations Mean (F)[Note 3] [Range]

Number of Non-Routine Results [Note 5]

Location Mean (F)[Note 3]

[Range]

Drinking Water (pCi/1)

GB / 8 I-131 / 8 H-3 / 8 GS / 8 Mn-54 Fe-59 Co-58 Co-60 Zn-65 Zr-95 Nb-95 Cs-134 Cs-137 Ba-140 La-140 4

1 2000 15 30 15 15 30 30 15 15 18 60 15 1.72 (4 / 4)

[1.57 - 1.88]

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD Station 57 (208°, 19.5 mi)

N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.07 (4 / 4)

[1.74 - 2.35]

N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A 2.07 (4 / 4)

[1.74 - 2.35]

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD 0

0 0

0 0

0 0

0 0

0 0

0 0

0 Fish (pCi/kg)

GS / 2 Mn-54 Fe-59 Co-58 Co-60 Zn-65 Cs-134 Cs-137 130 260 130 130 260 130 150

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD

< LLD 0

0 0

0 0

0 0

Plant: Arkansas Nuclear One Year: 2020 Page 28 of 63 Annual Radiological Environmental Operating Report Table 7, Radiological Environmental Monitoring Program Summary Sample Type (Units)

Type / Number of Analyses

[Note 1]

LLD [Note 2]

Indicator Locations Mean (F)[Note 3]

[Range]

Location [Note 4] [Highest Annual Mean]

Control Locations Mean (F)[Note 3] [Range]

Number of Non-Routine Results [Note 5]

Location Mean (F)[Note 3]

[Range]

Food Products (pCi/kg)

I-131 / 6 GS / 6 Cs-134 Cs-137 60 60 80

< LLD

< LLD

< LLD N/A N/A N/A N/A N/A N/A N/A N/A N/A 0

0 0

LEGEND:

[Note 1] - GB = Gross beta; I-131 = Iodine-131; H-3 = Tritium; GS = Gamma scan.

[Note 2] - LLD = Required lower limit of detection based on ANO Units 1 and 2 ODCM Table 2.5-1.

[Note 3] - Mean and range based upon detectable measurements only. Fraction of detectable measurements at specified locations is indicated in parenthesis (F).

[Note 4] - Locations are specified (1) by name and (2) degrees relative to reactor site.

[Note 5] - Non-routine results are those which exceed ten times the control station value. If no control station value is available, the result is considered non-routine if it exceeds ten times the preoperational value for the location.

[Note 6] - LLD is not defined in ANO Units 1 and 2 ODCM Table 2.5-1.

Plant: Arkansas Nuclear One Year: 2020 Page 29 of 63 Annual Radiological Environmental Operating Report Page 1 of 3 Sample Deviations Table 8, Sample Deviations Table Comment No.

Sample Media Affected Sample Location Date Problem Evaluation / Actions 1

Air Sample Air Station 2 04/21/2020 Suspected Power Loss Air Station 2 was 1.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> short. This was due to suspected power loss.

CR-ANO-C-2020-1223.

2 Air Sample Air Station 6 05/05/2020 Suspected Power Loss Air station # 6 lost power for 5.17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />. The power loss was due to severe storms. CR-ANO-C-2020-1334.

3 Air Sample Air Station 6 05/19/2020 Suspected Power Loss Air station # 6 lost power for 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> during the two-week sample collection period. CR-ANO-C-2020-1479.

4 Air Sample Air Station 2 06/02/2020 Power Loss Station 2 was 23.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> less than expected. This was due to air station 2 losing power on 5/27 at 1532. Chemistry was notified by the installed air station monitoring system that power had been lost to the station. The power loss was due to strong thunderstorms that blew through the area on 5/27/20. Entergy Arkansas was contacted, and power outage report was submitted to get powered restored. The monitoring system notified chemistry that power was restored on 5/28 at 1416 and chemistry staff went and verified shortly after the notification was received. CR-ANO-C-2020-1593.

Plant: Arkansas Nuclear One Year: 2020 Page 30 of 63 Annual Radiological Environmental Operating Report Page 2 of 3 Sample Deviations Table 8, Sample Deviations Table Comment No.

Sample Media Affected Sample Location Date Problem Evaluation / Actions 5

Air Sample Air Station 6 06/02/2020 Run-Time Totalizer Failure While performing the biweekly Air Particulate & Iodine Sampling in accordance Air Station 6 has had 3 consecutive sampling events where the run-time hours were lower than expected (CR-ANO-C-2020-1223, CR-ANO-C-2020-1334, &

CR-ANO-C-2020-1479). The installed monitoring system never indicated a power failure at the air station except for on 4/28/20 when power was lost due to a storm (CR-ANO-C-2020-1334). On 5/20/20 chemistry staff went to investigate the issue. It was determined that there had been no power outages and that the totalizer was not advancing appropriately. The faulty run-time totalizer was replaced with a verified functional totalizer. The sampling event that occurred on 6/2/20 had the correct run-time hours as expected at Station 6.

CR-ANO-C-2020-1596.

6 Air Sample Air Station 6 and 56 06/30/2020 Run-Time Totalizer Failure While collecting REMP air particulate and iodine samples from monitoring stations IAW EN-CY-130-01, it was determined that station #6 and #56 did not show the appropriate amount of runtime on the totalizer. There was no indication of power loss and the totalizer was observed advancing during sampling. CR-ANO-C-2020-1851.

7 TLD TLD 137 07/15/2020 Missing TLD The 2nd quarter TLD number 137 (located near Dardanelle National Guard Armory) was missing. TLD cage was present but top cap was missing.

CR-ANO-C-2020-1982.

8 Air Sample Air Station 1 08/11/2020 Power Loss Air station #1 had a power loss on 8-4-20 @ 19:32 hrs and was restored on 8 20 @ 08:08 hrs. Second power loss event was on 8-9-20 @ 06:12 hrs and power was restored on 8-9-20 at 09:18 hrs. Run time loss was due to GFCI trip on both occasions. Air station #6 had a run time loss of 1 hr and 13 minutes due to temporary power loss. CR-ANO-C-2020-2236.

Plant: Arkansas Nuclear One Year: 2020 Page 31 of 63 Annual Radiological Environmental Operating Report Page 3 of 3 Sample Deviations Table 8, Sample Deviations Table Comment No.

Sample Media Affected Sample Location Date Problem Evaluation / Actions 9

Air Sample Air Station 1 09/08/2020 Power Loss Chemistry noted that Air Station#1 near the Met Tower had a 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> delta in the run time for the two week sampling period. This was due to the GFCI tripped on 8-31-20 at ~0030 and power was reset at 0630 the same day.

CR-ANO-C-2020-2472.

10 Air Sample Air Station 1 and 6 09/22/2020 Power Loss While performing Bi-weekly air Monitoring(REMP) sampling chemistry documented short run times for the two-week sampling period than normal on Air Stations #1 and #6. This was expected and accounted for during the replacement and troubleshooting on station #1 power loss events due to GFCI trips on this station were:

9/10/20 1440 to 1520 9/13/20 0200 to 0900 9/14 0050 to 0150 Chemistry had GFCI replaced and replaced Sampling pump on this station with no further issues noted at this time.

Station #6 was due to external power loss in the sampling area on 9/9/20 from 1300 - 1600, power was restored, and no further issues noted.

CR-ANO-C-2020-2615.

Deviation was captured in 2020 AREOR. See attached deviation table.

Plant: Arkansas Nuclear One Year: 2020 Page 32 of 63 Annual Radiological Environmental Operating Report Page 1 of 15 Monitoring Results Tables Table 9, Air Particulate Data Summary Table Analysis: Gross Beta Units: pCi/m3 Start Date End Date Station 1 (Indicator)

Station 2 (Indicator)

Station 56 (Indicator)

Station 6[Note 1]

(Control)

Station 7 (Control)

REQUIRED LLD 0.01 0.01 0.01 0.01 0.01 12/31/2019 1/14/2020 1.14E-02 1.27E-02 1.17E-02 1.03E-02 1.05E-02 1/14/2020 1/28/2020 2.23E-02 1.77E-02 1.46E-02 1.76E-02 1.87E-02 1/28/2020 2/11/2020 9.13E-03 1.24E-02 1.07E-02 1.24E-02 1.35E-02 2/11/2020 2/25/2020 1.74E-02 1.68E-02 1.50E-02 1.59E-02 1.59E-02 2/25/2020 3/10/2020 1.33E-02 1.31E-02 1.20E-02 1.27E-02 1.65E-02 3/10/2020 3/24/2020 9.49E-03 1.09E-02 8.50E-03 1.16E-02 1.09E-02 3/24/2020 4/7/2020 1.57E-02 1.80E-02 1.54E-02 1.95E-02 1.60E-02 4/7/2020 4/21/2020 1.31E-02 1.18E-02 [Note 2]

1.06E-02 1.34E-02 1.31E-02 4/21/2020 5/5/2020 1.72E-02 1.78E-02 1.55E-02 1.70E-02 [Note 2]

1.50E-02 5/5/2020 5/19/2020 1.13E-02 1.49E-02 1.20E-02 1.46E-02 [Note 2]

1.36E-02 5/19/2020 6/2/2020 1.27E-02 8.95E-03 [Note 2]

1.30E-02 1.30E-02 [Note 2]

1.09E-02 6/2/2020 6/16/2020 1.65E-02 1.76E-02 1.46E-02 1.65E-02 1.57E-02 6/16/2020 6/30/2020 1.99E-02 1.91E-02 2.32E-02[Note 2]

2.48E-02 [Note 2]

1.63E-02 6/30/2020 7/14/2020 1.79E-02 1.67E-02 1.38E-02 1.67E-02 1.50E-02 7/14/2020 7/28/2020 1.30E-02 1.71E-02 8.55E-03 1.26E-02 1.62E-02 7/28/2020 8/11/2020 2.37E-02 [Note 2]

2.15E-02 2.26E-02 2.32E-02 2.16E-02 8/11/2020 8/25/2020 2.33E-02 2.55E-02 2.68E-02 2.57E-02 2.52E-02 8/25/2020 9/8/2020 1.68E-02 [Note 2]

1.60E-02 1.53E-02 1.92E-02 1.84E-02 9/8/2020 9/22/2020 2.82E-02 [Note 2]

3.52E-02 3.02E-02 3.31E-02 [Note 2]

3.47E-02 9/22/2020 10/6/2020 1.07E-02 2.07E-02 2.05E-02 1.90E-02 1.79E-02 10/6/2020 10/20/2020 1.72E-02 2.70E-02 2.50E-02 2.99E-02 2.55E-02 10/20/2020 11/3/2020 9.71E-03 1.75E-02 1.85E-02 1.86E-02 9.44E-03 11/3/2020 11/17/2020 1.75E-02 2.42E-02 2.61E-02 2.40E-02 1.60E-02 11/17/2020 12/1/2020 1.21E-02 1.74E-02 1.82E-02 2.04E-02 1.22E-02 12/1/2020 12/15/2020 2.41E-02 2.52E-02 3.04E-02 3.09E-02 1.65E-02

Plant: Arkansas Nuclear One Year: 2020 Page 33 of 63 Annual Radiological Environmental Operating Report Page 2 of 15 Monitoring Results Tables Table 9, Air Particulate Data Summary Table Analysis: Gross Beta Units: pCi/m3 Start Date End Date Station 1 (Indicator)

Station 2 (Indicator)

Station 56 (Indicator)

Station 6[Note 1]

(Control)

Station 7 (Control) 12/15/2020 12/29/2020 2.71E-02 2.36E-02 2.57E-02 2.57E-02 1.50E-02 Station Yearly Average 1.66E-02 1.84E-02 1.76E-02 1.92E-02 1.65E-02

[Note 1] - Station with highest annual mean.

[Note 2] - Reference Attachment 1, Sample Deviations, Table 8, Sample Deviations Table, Table 10, Radioiodine Cartridge Data Table Summary Analysis: I-131 Units: pCi/m3 Start Date End Date Station 1 (Indicator)

Station 2 (Indicator)

Station 56 (Indicator)

Station 6 (Control)

Station 7 (Control) 12/31/2019 1/14/2020

< 2.24E-02

< 2.25E-02

< 1.88E-02

< 2.23E-02

< 2.22E-02 1/14/2020 1/28/2020

< 1.89E-02

< 1.89E-02

< 1.89E-02

< 1.88E-02

< 1.58E-02 1/28/2020 2/11/2020

< 2.78E-02

< 2.79E-02

< 2.80E-02

< 1.15E-02

< 2.76E-02 2/11/2020 2/25/2020

< 2.33E-02

< 2.33E-02

< 2.33E-02

< 1.56E-02

< 2.32E-02 2/25/2020 3/10/2020

< 3.00E-02

< 3.00E-02

< 3.00E-02

< 1.26E-02

< 2.99E-02 3/10/2020 3/24/2020

< 2.66E-02

< 2.66E-02

< 2.66E-02

< 2.66E-02

< 2.22E-02 3/24/2020 4/7/2020

< 2.23E-02

< 2.23E-02

< 2.24E-02

< 2.23E-02

< 1.13E-02 4/7/2020 4/21/2020

< 1.77E-02

< 1.77E-02 [Note 1]

< 1.49E-02

< 1.78E-02

< 1.77E-02 4/21/2020 5/5/2020

< 1.63E-02

< 1.64E-02

< 1.64E-02

< 7.53E-03 [Note 1]

< 1.62E-02 5/5/2020 5/19/2020

< 2.93E-02

< 2.94E-02

< 2.46E-02

< 3.05E-02 [Note 1]

< 2.92E-02 5/19/2020 6/2/2020

< 1.72E-02

< 1.84E-02 [Note 1]

< 1.71E-02

< 1.03E-02 [Note 1]

< 1.73E-02 6/2/2020 6/16/2020

< 1.91E-02

< 1.90E-02

< 1.12E-02

< 1.74E-02

< 1.88E-02 6/16/2020 6/30/2020

< 2.46E-02

< 2.46E-02

< 1.63E-02 [Note 1]

< 2.86E-02 [Note 1]

< 2.44E-02 6/30/2020 7/14/2020

< 4.28E-02

< 4.27E-02

< 4.28E-02

< 4.20E-02

< 1.78E-02 7/14/2020 7/28/2020

< 2.42E-02

< 2.42E-02

< 2.42E-02

< 1.02E-02

< 2.41E-02 7/28/2020 8/11/2020

< 1.58E-02 [Note 1]

< 3.59E-02

< 3.58E-02

< 3.57E-02

< 3.53E-02 8/11/2020 8/25/2020

< 3.78E-02

< 1.59E-02

< 3.79E-02

< 3.78E-02

< 3.77E-02 8/25/2020 9/8/2020

< 1.67E-02 [Note 1]

< 3.90E-02

< 3.89E-02

< 3.88E-02

< 3.86E-02

Plant: Arkansas Nuclear One Year: 2020 Page 34 of 63 Annual Radiological Environmental Operating Report Page 3 of 15 Monitoring Results Tables Table 10, Radioiodine Cartridge Data Table Summary Analysis: I-131 Units: pCi/m3 Start Date End Date Station 1 (Indicator)

Station 2 (Indicator)

Station 56 (Indicator)

Station 6 (Control)

Station 7 (Control) 9/8/2020 9/22/2020

< 2.68E-02 [Note 1]

< 2.61E-02

< 2.61E-02

< 2.62E-02 [Note 1]

< 1.08E-02 9/22/2020 10/6/2020

< 2.70E-02

< 2.70E-02

< 2.70E-02

< 2.69E-02

< 2.69E-02 10/6/2020 10/20/2020

< 2.16E-02

< 2.17E-02

< 1.82E-02

< 2.16E-02

< 2.13E-02 10/20/2020 11/3/2020

< 7.97E-03

< 7.91E-03

< 7.90E-03

< 7.89E-03

< 7.84E-03 11/3/2020 11/17/2020

< 2.52E-02

< 2.54E-02

< 1.07E-02

< 2.51E-02

< 2.51E-02 11/17/2020 12/1/2020

< 2.91E-02

< 2.91E-02

< 2.91E-02

< 1.22E-02

< 2.89E-02 12/1/2020 12/15/2020

< 1.85E-02

< 1.86E-02

< 1.86E-02

< 7.77E-03

< 1.85E-02 12/15/2020 12/29/2020

< 1.51E-02

< 3.59E-02

< 3.59E-02

< 3.59E-02

< 3.57E-02 Station Yearly Average

<LLD

<LLD

<LLD

<LLD

<LLD

[Note 1] - Reference Attachment 1, Sample Deviations, Table 8, Sample Deviations Table,

Plant: Arkansas Nuclear One Year: 2020 Page 35 of 63 Annual Radiological Environmental Operating Report Page 4 of 15 Monitoring Results Tables Table 11, Thermoluminescent Dosimeters - Inner Ring Analysis: Gamma Dose Units: mrem Station 1st Qtr

[2020]

2nd Qtr

[2020]

3rd Qtr

[2020]

4th Qtr

[2020]

Annual Mean

[2020]

1 7.6 8.6 8.4 8.8 8.4 2

6.3 6.7 8.0 8.7 7.4 3

4.8 4.5 5.1 5.9 5.1 4

7.1 6.9 7.8 8.1 7.5 56[Note 1]

8.7 8.3 9.5 11.2 9.4 108 8.2 7.4 8.6 8.7 8.2 109 7.0 8.2 8.5 8.8 8.1 110 7.5 7.2 7.8 8.4 7.7 145 6.8 7.0 7.2 7.8 7.2 146 6.7 6.8 7.5 7.8 7.2 147 6.5 6.7 6.5 7.5 6.8 148 7.0 7.3 8.0 8.5 7.7 149 6.6 6.6 11.3 7.3 8.0 150 8.1 8.6 8.7 9.3 8.7 151 7.3 8.0 8.5 8.5 8.1 152 5.7 6.2 6.4 6.7 6.3

[Note 1] - Station with highest annual mean.

Plant: Arkansas Nuclear One Year: 2020 Page 36 of 63 Annual Radiological Environmental Operating Report Page 5 of 15 Monitoring Results Tables Table 12, Thermoluminescent Dosimeters - Special Interest Areas Analysis: Gamma Dose Units: mrem Station 1st Qtr [2020]

2nd Qtr [2020]

3rd Qtr [2020]

4th Qtr [2020]

Annual Mean

[2020]

6 7.0 6.6 6.5 7.5 6.9 111 5.0 4.6 4.9 6.0 5.1 116[Note 1]

8.3 8.5 8.1 9.1 8.5 125 4.8 5.0 4.9 7.9 5.7 127 6.6 7.3 6.7 7.9 7.1 137 7.3 0 [Note 2]

7.4 8.5 7.7 153 6.0 6.7 7.5 7.6 7.0

[Note 1] - Station with highest annual mean.

[Note 2] - Reference Attachment 1, Sample Deviations, Table 8, Sample Deviations Table Table 13, Thermoluminescent Dosimeters - Control Analysis: Gamma Dose Units: mrem Station 1st Qtr [2020]

2nd Qtr [2020]

3rd Qtr [2020]

4th Qtr [2020]

Annual Mean

[2020]

7 5.3 5.8 5.9 6.9

6.0 Plant

Arkansas Nuclear One Year: 2020 Page 37 of 63 Annual Radiological Environmental Operating Report Page 6 of 15 Monitoring Results Tables Table 14, Surface Water - Gamma Analysis: Gamma Isotopic Units: pCi/L Location Start Date End Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 REQUIRED LLD 15 15 30 15 30 15 30 15 15 18 60 15 Station 8 (Indicator) 12/31/2019 01/31/2020

< 1.69

< 1.86

< 4.40

< 1.62

< 3.42

< 1.92

< 3.18

< 8.97

< 1.73

< 1.73

< 16.2

< 5.17 Station 10 (Control) 12/31/2019 01/31/2020

< 8.57

< 8.30

< 18.0

< 8.78

< 15.1

< 7.88

< 12.7

< 9.84

< 9.24

< 6.29

< 39.2

< 7.66 Station 8 (Indicator) 01/31/2020 02/28/2020

< 1.76

< 1.99

< 4.05

< 1.71

< 3.48

< 2.11

< 3.41

< 8.01

< 1.87

< 1.90

< 15.5

< 4.78 Station 10 (Control) 01/31/2020 02/28/2020

< 5.41

< 5.30

< 13.5

< 6.82

< 10.3

< 5.84

< 12.3

< 8.19

< 6.98

< 5.82

< 26.8

< 8.23 Station 8 (Indicator) 02/28/2020 03/31/2020

< 1.82

< 2.02

< 4.47

< 2.03

< 3.90

< 2.10

< 3.40

< 8.12

< 1.79

< 1.84

< 16.1

< 5.25 Station 10 (Control) 02/28/2020 03/31/2020

< 6.04

< 5.35

< 10.6

< 6.07

< 12.6

< 4.25

< 9.83

< 6.00

< 7.23

< 6.52

< 17.9

< 9.15 Station 8 (Indicator) 03/31/2020 04/30/2020

< 1.44

< 1.67

< 3.69

< 1.51

< 2.97

< 1.73

< 3.10

< 9.01

< 1.57

< 1.65

< 16.2

< 5.36 Station 10 (Control) 03/31/2020 04/30/2020

< 5.27

< 4.86

< 11.9

< 8.49

< 13.1

< 6.03

< 13.3

< 11.2

< 7.47

< 7.12

< 32.0

< 7.90 Station 8 (Indicator) 04/30/2020 05/31/2020

< 1.64

< 1.98

< 4.21

< 1.97

< 3.71

< 2.13

< 3.40

< 7.34

< 1.93

< 1.94

< 15.3

< 5.68 Station 10 (Control) 04/30/2020 05/31/2020

< 7.94

< 7.11

< 11.4

< 5.60

< 8.99

< 6.90

< 11.9

< 8.86

< 7.12

< 8.85

< 26.4

< 10.1

Plant: Arkansas Nuclear One Year: 2020 Page 38 of 63 Annual Radiological Environmental Operating Report Page 7 of 15 Monitoring Results Tables Table 14, Surface Water - Gamma Analysis: Gamma Isotopic Units: pCi/L Location Start Date End Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Station 8 (Indicator) 05/31/2020 06/30/2020

< 1.80

< 2.14

< 4.96

< 1.88

< 3.90

< 2.20

< 3.68

< 12.2

< 2.06

< 1.85

< 20.7

< 6.81 Station 10 (Control) 05/31/2020 06/30/2020

< 5.72

< 7.11

< 11.7

< 5.96

< 13.1

< 5.38

< 12.8

< 9.56

< 6.98

< 6.62

< 24.6

< 8.03 Station 8 (Indicator) 06/30/2020 07/31/2020

< 1.59

< 1.78

< 4.21

< 1.70

< 3.08

< 1.86

< 3.27

< 11.6

< 1.71

< 1.70

< 17.9

< 6.43 Station 10 (Control) 06/30/2020 07/31/2020

< 5.65

< 6.73

< 17.1

< 9.65

< 13.5

< 6.62

< 12.8

< 8.90

< 7.70

< 6.86

< 27.2

< 9.19 Station 8 (Indicator) 07/31/2020 08/31/2020

< 2.41

< 2.99

< 6.06

< 2.55

< 4.92

< 3.01

< 5.17

< 14.3

< 2.82

< 2.90

< 26.0

< 7.45 Station 10 (Control) 07/31/2020 08/31/2020

< 5.05

< 5.00

< 15.9

< 6.98

< 10.9

< 6.59

< 9.00

< 8.67

< 6.44

< 5.93

< 25.8

< 7.94 Station 8 (Indicator) 08/31/2020 09/30/2020

< 1.66

< 1.80

< 4.23

< 1.65

< 3.79

< 2.18

< 3.47

< 8.43

< 2.06

< 1.79

< 16.4

< 5.98 Station 10 (Control) 08/31/2020 09/30/2020

< 6.34

< 6.05

< 11.4

< 7.39

< 13.3

< 8.41

< 9.42

< 8.39

< 8.01

< 6.23

< 26.5

< 10.5 Station 8 (Indicator) 09/30/2020 10/31/2020

< 1.67

< 1.83

< 4.10

< 1.69

< 3.40

< 1.85

< 3.21

< 9.31

< 1.73

< 1.66

< 15.9

< 5.04 Station 10 (Control) 09/30/2020 10/31/2020

< 5.75

< 5.94

< 11.2

< 7.01

< 10.8

< 5.69

< 10.4

< 8.48

< 6.66

< 7.04

< 27.4

< 5.10

Plant: Arkansas Nuclear One Year: 2020 Page 39 of 63 Annual Radiological Environmental Operating Report Page 8 of 15 Monitoring Results Tables Table 14, Surface Water - Gamma Analysis: Gamma Isotopic Units: pCi/L Location Start Date End Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 Station 8 (Indicator) 10/31/2020 11/30/2020

< 1.65

< 1.92

< 4.68

< 1.60

< 3.41

< 2.08

< 3.30

< 14.0

< 1.79

< 1.71

< 21.1

< 6.35 Station 10 (Control) 10/31/2020 11/30/2020

< 2.79

< 2.80

< 6.04

< 2.58

< 5.23

< 2.96

< 5.15

< 5.72

< 2.85

< 2.73

< 15.0

< 5.23 Station 8 (Indicator) 11/30/2020 12/31/2020

< 1.95

< 2.39

< 5.03

< 2.08

< 4.25

< 2.31

< 4.19

< 11.2

< 1.98

< 1.83

< 19.7

< 6.69 Station 10 (Control) 11/30/2020 12/31/2020

< 8.06

< 9.06

< 16.4

< 7.93

< 13.7

< 7.22

< 13.2

< 10.2

< 5.04

< 7.43

< 31.1

< 11.1

Plant: Arkansas Nuclear One Year: 2020 Page 40 of 63 Annual Radiological Environmental Operating Report Page 9 of 15 Monitoring Results Tables Table 15, Surface Water - Tritium Analysis: H-3 Units: pCi/L Location Start Date End Date H-3 REQUIRED LLD 3000 Station 8 (Indicator) 12/31/2019 03/31/2020 5141 Station 10 (Control) 12/31/2019 03/31/2020

< 357 Station 8 (Indicator) 03/31/2020 06/30/2020 9862 Station 10 (Control) 03/31/2020 06/30/2020

<359 Station 8 (Indicator) 06/30/2020 09/30/2020

<370 Station 10 (Control) 06/30/2020 09/30/2020

<372 Station 8 (Indicator) 09/30/2020 12/31/2020 958 Station 10 (Control) 09/30/2020 12/31/2020

<303

Plant: Arkansas Nuclear One Year: 2020 Page 41 of 63 Annual Radiological Environmental Operating Report Page 10 of 15 Monitoring Results Tables Table 16, Drinking Water -Gamma, GB, I-131 Analysis: Gamma Isotopic, Gross Beta, I-131 Units: pCi/L Location Collection Date Gross Beta Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 REQUIRED LLD 4.0 15 15 30 15 30 15 30 1.0 15 18 60 15 Station 14 (Indicator) 01/07/2020

< 1.57

< 4.47

< 5.48

< 8.71

< 4.67

< 8.85

< 5.10

< 8.06

<0.566

< 5.46

< 4.46

< 16.9

< 4.66 Station 57 (Control) 01/07/2020 2.34

< 4.31

< 4.81

< 10.6

< 4.90

< 10.4

< 4.50

< 6.98

< 0.393

< 5.51

< 5.05

< 17.7

< 5.99 Station 14 (Indicator) 04/04/2020

< 1.72

< 6.73

< 5.94

< 10.5

< 7.85

< 12.4

< 6.27

<11.1

<0.576

< 7.89

< 6.47

<20.1

< 6.09 Station 57 (Control) 04/04/2020

< 1.74

< 7.17

< 8.30

< 15.6

< 8.01

< 12.2

< 6.10

< 12.8

<0.518

< 8.94

< 9.01

< 24.3

< 8.66 Station 14 (Indicator) 7/13/2020

< 1.70

< 8.28

< 7.97

< 10.2

< 7.13

< 14.6

< 8.68

< 14.3

< 0.565

< 9.76

< 7.19

< 41.7

< 7.94 Station 57 (Control) 7/13/2020 1.85

< 7.28

< 7.45

< 17.6

< 6.67

< 14.2

< 7.29

< 11.7

< 0.794

< 7.29

< 6.72

< 31.8

< 7.92 Station 14 (Indicator) 10/06/2020 1.88

< 3.60

< 6.18

< 12.5

< 6.32

< 12.2

< 6.25

< 11.1

< 0.765

< 7.86

< 7.27

< 21.4

< 4.32 Station 57 (Control) 10/06/2020 2.35

< 6.20

< 5.93

< 11.5

< 5.25

< 13.0

< 6.08

< 9.87

< 0.654

< 6.35

< 6.65

< 23.6

< 7.90

Plant: Arkansas Nuclear One Year: 2020 Page 42 of 63 Annual Radiological Environmental Operating Report Page 11 of 15 Monitoring Results Tables Table 17, Drinking Water - Tritium Analysis: H-3 Units: pCi/L Location Collection Date H-3 REQUIRED LLD 2000 Station 14 (Indicator) 01/07/2020

< 302 Station 57 (Control) 01/07/2020

< 295 Station 14 (Indicator) 04/04/2019

< 332 Station 57 (Control) 04/04/2019

< 336 Station 14 (Indicator) 07/13/2020

< 377 Station 57 (Control) 07/13/2020

< 387 Station 14 (Indicator) 10/06/2020

< 352 Station 57 (Control) 10/06/2020

< 349 Table 18, Sediment Analysis: Gamma Isotopic Units: pCi/kg Location Collection Date Cs-134 Cs-137 REQUIRED LLD 150 180 Station 8 (Indicator) 05/22/2020

< 82.3

< 101 Station 16 (Control) 05/22/2020

< 110

< 123

Plant: Arkansas Nuclear One Year: 2020 Page 43 of 63 Annual Radiological Environmental Operating Report Page 12 of 15 Monitoring Results Tables Table 19, Fish Analysis: Gamma Isotopic Units: pCi/kg Location Collection Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Cs-134 Cs-137 REQUIRED LLD 130 130 260 130 260 130 150 Station 8 (Indicator) 03/06/2020

< 49.8

< 56.8

< 126

< 78.2

< 161

< 72.8

< 69.9 Station 16 (Control) 5/22/2020

< 77.0

< 65.9

< 142

< 96.4

< 144

< 50.2

< 83.2 Table 20, Food Products Analysis: I-131, Gamma Isotopic Units: pCi/kg Location Collection Date I-131 Cs-134 Cs-137 REQUIRED LLD 60 60 80 Station 13 (Indicator) 06/16/2020

< 56.1

< 47.3

< 40.2 Station 55 (Control) 06/16/2020

< 38.2

< 33.9

< 38.4 Station 13 (Indicator) 07/14/2020

< 53.0

< 26.4

< 26.2 Station 55 (Control) 07/14/2020

< 46.4

< 33.1

< 29.8 Station 13 (Indicator) 08/11/2020

< 55.0

< 34.4

< 35.3 Station 55 (Control) 08/11/2020

< 48.1

< 37.0

< 31.3

Plant: Arkansas Nuclear One Year: 2020 Page 44 of 63 Annual Radiological Environmental Operating Report Page 13 of 15 Monitoring Results Tables Table 21, Groundwater - Gamma and Iodine Analysis: Gross Beta, I-131, Gamma Isotopic Units: pCi/L Location Collection Date Gr-B Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 REQUIRED LLD N/A[Note 1]

15 15 30 15 30 15 30 15 15 18 60 15 Station 58 (Control) 03/13/2020 2.47

< 4.70E

< 4.64

< 9.36

< 4.57

< 8.48

< 5.02

< 7.92

< 10.2

< 5.00

< 4.62

< 26.5

< 8.70 Station 62 (Control) 03/12/2020

< 1.43

< 4.71

< 5.55

< 10.7

< 4.72

< 11.6

< 5.14

< 10.9

< 11.4

< 6.11

< 5.75

< 23.4

< 11.1 Station 63 (Indicator) 03/12/2020

< 2.24

< 4.80

< 4.30

< 10.1

< 5.24

< 8.51

< 4.78

< 6.84

< 10.7

< 5.34

< 4.12

< 24.5

< 9.71 Station 64 (Indicator) 03/13/2020

< 3.25

< 6.02

< 5.66

< 11.5

< 6.06

< 13.4

< 8.52

< 11.3

< 11.0

< 6.16

< 6.43

< 31.8

< 10.5 Station 58 (Control) 06/09/2020

<1.67

< 6.91

< 7.68

< 13.3

< 7.59

< 9.56

< 7.31

< 12.8

< 13.6

< 6.64

< 6.28

< 24.7

< 10.2 Station 62 (Control) 06/09/2020

<2.92

< 6.95

< 5.66

< 10.3

< 7.64

< 8.49

< 6.86

< 13.1

< 11.3

< 7.73

< 5.94

< 31.5

< 8.36 Station 63 (Indicator) 06/09/2020 5.31

< 4.91

< 5.46

< 10.4

< 6.94

< 9.69

< 5.47

< 9.60

< 9.74

< 5.63

< 4.79

< 29.3

< 11.6 Station 64 (Indicator) 06/10/2020 2.60

< 5.63

< 7.31

< 11.9

< 8.46

< 13.3

< 7.15

< 10.3

< 11.5

< 7.37

< 5.96

< 33.0

< 9.59

Plant: Arkansas Nuclear One Year: 2020 Page 45 of 63 Annual Radiological Environmental Operating Report Page 14 of 15 Monitoring Results Tables Table 21, Groundwater - Gamma and Iodine Analysis: Gross Beta, I-131, Gamma Isotopic Units: pCi/L Location Collection Date Gr-B Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 I-131 Cs-134 Cs-137 Ba-140 La-140 REQUIRED LLD N/A[Note 1]

15 15 30 15 30 15 30 15 15 18 60 15 Station 58 (Control) 09/18/2020

<1.90

< 7.62

< 9.09

< 15.7

< 8.29

< 19.9

< 10.2

< 14.5

< 14.7

< 6.70

< 8.03

< 39.5

< 13.8 Station 62 (Control) 09/18/2020

<3.87

< 5.88

< 7.54

< 16.5

< 6.77

< 15.0

< 6.82

< 11.0

< 13.9

< 8.02

< 7.74

< 40.3

< 9.68 Station 63 (Indicator) 09/18/2020 8.33

< 8.54

< 7.73

< 17.1

< 4.24

< 19.0

< 8.32

< 10.6

< 11.9

< 8.59

< 8.60

< 34.1

< 10.4 Station 64 (Indicator) 09/09/2020

<3.26

< 4.17

< 4.03

< 10.6

< 4.08

< 9.68

< 5.45

< 8.53

< 14.6

< 5.21

< 4.37

< 27.8

< 10.5 Station 58 (Control) 12/08/2020

<1.97

< 9.76

< 10.7

< 21.2

< 10.2

< 25.7

< 14.1

< 23.0

< 13.0

< 10.3

< 10.3

< 43.3

< 13.7 Station 62 (Control) 12/08/2020

<2.75

< 7.68

< 6.92

< 15.8

< 7.38

< 14.3

< 8.27

< 12.8

< 8.50

< 9.38

< 7.30

< 33.7

< 8.95 Station 63 (Indicator) 12/08/2020

<3.66

< 5.81

< 6.44

< 14.3

< 6.54

< 17.7

< 5.92

< 11.8

< 9.48

< 7.25

< 7.75

< 36.4

< 5.74 Station 64 (Indicator) 12/09/2020 3.39

< 8.74

< 8.30

< 18.1

< 9.90

< 19.3

< 12.3

< 16.6

< 12.0

< 11.5

< 9.90

< 37.5

< 12.5

[Note 1] - Per ANOs ODCM there is no Gross Beta LLD for groundwater or a reportable detectable concentration.

Plant: Arkansas Nuclear One Year: 2020 Page 46 of 63 Annual Radiological Environmental Operating Report Page 15 of 15 Monitoring Results Tables Table 22, Groundwater - Tritium Analysis: H-3 Units: pCi/L Location Collection Date H-3 REQUIRED LLD 3000 Station 58 (Control) 03/13/2020

< 355 Station 62 (Control) 03/12/2020

< 361 Station 63 (Indicator) 03/12/2020

< 346 Station 64 (Indicator) 03/13/2020

< 395 Station 58 (Control) 06/09/2020

<336 Station 62 (Control) 06/09/2020

<331 Station 63 (Indicator) 06/09/2020

<330 Station 64 (Indicator) 06/10/2020

<325 Station 58 (Control) 09/18/2020

<366 Station 62 (Control) 09/18/2020

<376 Station 63 (Indicator) 09/18/2020

<384 Station 64 (Indicator) 09/09/2020

<373 Station 58 (Control) 12/08/2020

<327 Station 62 (Control) 12/08/2020

<302 Station 63 (Indicator) 12/08/2020

<312 Station 64 (Indicator) 12/09/2020

<339

Plant: Arkansas Nuclear One Year: 2020 Page 47 of 63 Annual Radiological Environmental Operating Report Page 1 of 3 Interlaboratory Comparison Program Results 1.0

SUMMARY

1.1 Summary of Results - Inter-laboratory Comparison Program (ICP)

The TBE Laboratory analyzed Performance Evaluation (PE) samples of air particulate (AP), air iodine, milk, soil, vegetation, and water matrices for various analytes. The PE samples supplied by 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:

1.

Analytics Evaluation Criteria Analytics evaluation report provides a ratio of TBEs result and Analytics known value. Since flag values are not assigned by Analytics, TBE evaluates the reported ratios based on internal QC requirements based on the DOE MAPEP criteria.

2.

ERA Evaluation Criteria ERAs evaluation report provides an acceptance range for control and warning limits with associated flag values. ERAs acceptance limits are established per the US EPA, National Environmental Laboratory Accreditation Conference (NELAC), state-specific Performance Testing (PT) program requirements or ERAs 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.

3.

DOE Evaluation Criteria MAPEPs evaluation report provides an acceptance range with associated flag values. MAPEP defines three levels of performance:

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

of the reference value 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 resemble typical environmental samples obtained at commercial nuclear power facilities.

Plant: Arkansas Nuclear One Year: 2020 Page 48 of 63 Annual Radiological Environmental Operating Report Page 2 of 3 Interlaboratory Comparison Program Results

4.

For the TBE laboratory, 126 out of 133 analyses performed met the specified acceptance criteria. Seven analyses did not meet the specified acceptance criteria for the following reasons and were addressed through the TBE Corrective Action Program. A summary is found below:

a.

The MAPEP February 2020 AP U-233/234 and U-238 results were evaluated as Not Acceptable. The reported value for U-233/234 was 0.0416 +/- 0.0102 Bq/sample and the known result was 0.075 Bq/sample (acceptance range 0.053 - 0.098). The reported value for U-238 was 0.0388 +/- 0.00991 Bq/sample and the known result was 0.078 Bq/sample (acceptance range 0.055 - 0.101). This sample was run as the workgroup duplicate and had RPDs of 10.4% (U-234) and 11.7% (U-238). After the known results were obtained, the sample was relogged.

The filter was completely digested with tracer added originally; the R1 results were almost identical. It was concluded that the recorded tracer amount was actually double, causing the results to be skewed. Lab worksheets have been modified to verify actual tracer amount vs. LIMS data. TBE changed vendors for this cross-check to ERA MRAD during the 2nd half of 2020. Results were acceptable at 97.8% for U-234 and 106%

for U-238. (NCR 20-13)

b.

The Analytics September 2020 milk Sr-89 result was evaluated as Not Acceptable. The reported value was 62.8 pCi/L and the known result was 95.4 (66%). All QC data was reviewed and there were no anomalies.

This was the first failure for milk Sr-89 since 2013 and there have only been 3 upper/lower boundary warnings since that time. It is believed that there may have been some Sr-89 loss during sample prep. The December 2020 result was at 92% of the known. (NCR 20-19)

c.

The ERA October 2020 water I-131 result was evaluated as Not Acceptable. The reported value was 22.9 pCi/L and the known result was 28.2 (acceptance range 23.5 - 33.1). The reported result was 81% of the known, which passes TBE QC criteria. This was the first failure for water I-131. (NCR 20-17)

d.

The ERA October 2020 water Gross Alpha and Gross Beta results were evaluated as Not Acceptable. The reported/acceptable values and ranges are as follows:

Reported Known Range Gross Alpha 40.0 26.2 13.3-34.7 Gross Beta 47.5 69.1 48.0-76.0 All QC data was reviewed with no anomalies and a cause for failure could not be determined. This was the first failure for water Gross Beta. A Quick Response follow-up cross-check was analyzed as soon as possible with acceptable results at 96.8% for Gross Alpha and 102% for Gross Beta. (NCR 20-18)

Plant: Arkansas Nuclear One Year: 2020 Page 49 of 63 Annual Radiological Environmental Operating Report Page 3 of 3 Interlaboratory Comparison Program Results

e.

The MAPEP August 2020 soil Ni-63 result was evaluated as Not Acceptable. The reported value was 438 +/- 21.1 Bq/kg and the known result was 980 Bq/kg (acceptance range 686 - 1274). It is believed that some Ni-63 loss occurred during the sample prep step. (NCR 20-20)

f.

The Analytics September 2019 soil Cr-51 sample was evaluated as Not Acceptable. TBEs reported result of 0.765 +/- 0.135 pCi/g exceeded the upper acceptance range (140% of the known result of 0.547 pCi/g). The TBE result was within the acceptable range (0.63 - 0.90 pCi/g) with the associated error. The Cr-51 result is very close to TBEs normal detection limit. In order to get a reportable result, the sample must be counted for 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> (10x longer than client samples). There is no client or regulatory requirement for this nuclide and TBE will remove Cr-51 from the reported gamma nuclides going forward. (NCR 19-27)

5.

The Inter-Laboratory Comparison Program provides evidence of in control counting systems and methods, and that the laboratories are producing accurate and reliable data.

Plant: Arkansas Nuclear One Year: 2020 Page 50 of 63 Annual Radiological Environmental Operating Report Page 1 of 15 Environmental Dosimetry Company Interlaboratory Comparison Program Report ENVIRONMENTAL DOSIMETRY COMPANY ANNUAL QUALITY ASSURANCE STATUS REPORT January - December 2019 10 Ashton Lane Sterling, MA 01564

Plant: Arkansas Nuclear One Year: 2020 Page 51 of 63 Annual Radiological Environmental Operating Report Page 2 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report 1.0 EXECUTIVE

SUMMARY

Routine quality control (QC) testing was performed for dosimeters issued by the Environmental Dosimetry Company (EDC).

During this annual period100% (72/72) of the individual dosimeters, evaluated against the EDC internal performance acceptance criteria (high-energy photons only), met the criterion for accuracy and 100% (72/72) met the criterion for precision (Table 1).

In addition, 100% (12/12) of the dosimeter sets evaluated against the internal tolerance limits met EDC acceptance criteria (Table 2) and 100% (6/6) of independent testing passed the performance criteria (Table 3). Trending graphs, which evaluate performance statistic for high-energy photon irradiations and co-located stations are given in Appendix A.

One internal assessment and one external audit were performed in 2020.There was one deficiency issued in the external audit.

2.0 INTRODUCTION

The TLD systems at the Environmental Dosimetry Company (EDC) are calibrated and operated to ensure consistent and accurate evaluation of TLDs. The quality of the dosimetric results reported to EDC clients is ensured by in house performance testing and independent performance testing by EDC clients, and both internal and client directed program assessments.

The purpose of the dosimetry quality assurance program is to provide performance documentation of the routine processing of EDC dosimeters. Performance testing provides a statistical measure of the bias and precision of dosimetry processing against a reliable standard, which in turn points out any trends or performance changes. Two programs are used:

2.1 QC Program The TLD systems at the Environmental Dosimetry Company (EDC) are calibrated and operated to ensure consistent and accurate evaluation of TLDs. The quality of the dosimetric results reported to EDC clients is ensured by in-house performance testing and independent performance testing by EDC clients, and both internal and client directed program assessments.

The purpose of the dosimetry quality assurance program is to provide performance documentation of the routine processing of EDC dosimeters. Performance testing provides a statistical measure of the bias and precision of dosimetry processing against a reliable standard, which in turn points out any trends or performance changes. Two programs are used:

Plant: Arkansas Nuclear One Year: 2020 Page 52 of 63 Annual Radiological Environmental Operating Report Page 3 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report 2.2 QA Program An internal assessment of dosimetry activities is conducted annually by the Quality Assurance Officer (Reference 1). The purpose of the assessment is to review procedures, results, materials or components to identify opportunities to improve or enhance processes and/or services.

3.0 PERFORMANCE EVALUATION CRITERIA 3.1 Acceptance Criteria for Internal Evaluations

1.

Bias For each dosimeter tested, the measure of bias is the percent deviation of the reported result relative to the delivered exposure. The percent deviation relative to the delivered exposure is calculated as follows:

i i

i H

H 100 H

Where:

H'i=the corresponding reported exposure for the ith dosimeter (i.e., the reported exposure)

Hi =the exposure delivered to the ith irradiated dosimeter (i.e., the delivered exposure)

2.

Mean Bias For each group of test dosimeters, the mean bias is the average percent deviation of the reported result relative to the delivered exposure. The mean percent deviation relative to the delivered exposure is calculated as follows:

i i

i H

H 1

100 H

n Where:

H'i = the corresponding reported exposure for the ith dosimeter (i.e., the reported exposure)

Hi = the exposure delivered to the ith irradiated test dosimeter (i.e., the delivered exposure) n = the number of dosimeters in the test group

Plant: Arkansas Nuclear One Year: 2020 Page 53 of 63 Annual Radiological Environmental Operating Report Page 4 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report

3.

Precision For a group of test dosimeters irradiated to a given exposure, the measure of precision is the percent deviation of individual results relative to the mean reported exposure. At least two values are required for the determination of precision. The measure of precision for the ith dosimeter is:

i i

i H

H 1

100 H

n Where:

H'i = the reported exposure for the ith dosimeter (i.e., the reported exposure)

Hi = the mean reported exposure; i.e.

n = the number of dosimeters in the test group

4.

EDC Internal Tolerance Limits All evaluation criteria are taken from the EDC Quality System Manual, (Reference 2). These criteria are only applied to individual test dosimeters irradiated with high-energy photons (Cs 137) and are as follows for Panasonic Environmental dosimeters: +/- 15% for bias and +/- 12.8% for precision.

3.2 QC Investigation Criteria and Result Reporting EDC Quality System Manual (Reference 2) specifies when an investigation is required due to a QC analysis that has failed the EDC bias criteria. The criteria are as follows:

1.

No investigation is necessary when an individual QC result falls outside the QC performance criteria for accuracy.

2.

Investigations are initiated when the mean of a QC processing batch is outside the performance criterion for bias.

Plant: Arkansas Nuclear One Year: 2020 Page 54 of 63 Annual Radiological Environmental Operating Report Page 5 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report 3.3 Reporting of Environmental Dosimetry Results to EDC Customers

1.

All results are to be reported in a timely fashion.

2.

If the QA Officer determines that an investigation is required for a process, the results shall be issued as normal. If the QC results prompting the investigation have a mean bias from the known of greater than +/-20%, the results shall be issued with a note indicating that they may be updated in the future, pending resolution of a QA issue.

3.

Environmental dosimetry results do not require updating if the investigation has shown that the mean bias between the original results and the corrected results, based on applicable correction factors from the investigation, does not exceed +/-20%.

Plant: Arkansas Nuclear One Year: 2020 Page 55 of 63 Annual Radiological Environmental Operating Report Page 6 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report 4.0 DATA

SUMMARY

FOR ISSUANCE PERIOD JANUARY-DECEMBER 2018 4.1 General Discussion Results of performance tests conducted are summarized and discussed in the following sections. Summaries of the performance tests for the reporting period are given in Tables 1 through 3 and Figures 1 through 4.

Table 1 provides a summary of individual dosimeter results evaluated against the EDC internal acceptance criteria for high-energy photons only. During this period100% (72/72) of the individual dosimeters, evaluated against these criteria, met the tolerance limits for accuracy and 100% (72/72) met the criterion for precision. A graphical interpretation is provided in Figures 1 and 2.

Table 2 provides the bias and standard deviation results for each group (N=6) of dosimeters evaluated against the internal tolerance criteria. Overall,100% (12/12) of the dosimeter sets, evaluated against the internal tolerance performance criteria, met these criteria. A graphical interpretation is provided in Figure 3.

Table 3 presents the independent blind spike results for dosimeters processed during this annual period. All results passed the performance acceptance criterion. Figure 4 is a graphical interpretation of Seabrook Station blind co-located station results.

4.2 Result Trending One of the main benefits of performing quality control tests on a routine basis is to identify trends or performance changes. The results of the Panasonic environmental dosimeter performance tests are presented in Appendix A. The results are evaluated against each of the performance criteria listed in Section II, namely: individual dosimeter accuracy, individual dosimeter precision, and mean bias.

All of the results presented in Appendix A are plotted sequentially by processing date.

5.0 STATUS OF EDC CONDITION REPORTS (CR)

During this annual period, one EDC Condition Report was issued. CR 1-2020 was issued to document the deficiency from the DTE Energy Audit 20-003.

6.0 STATUS OF AUDITS/ASSESSMENTS

1.

Internal EDC Internal Quality Assurance Assessment was conducted during the fourth quarter 2020. There were no findings identified.

2.

External DTE Energy Audit 20-003 was conducted on July 28-30, 2020. There was one deficiency identified.

Plant: Arkansas Nuclear One Year: 2020 Page 56 of 63 Annual Radiological Environmental Operating Report Page 7 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report 7.0 PROCEDURES AND MANUALS REVISED DURING JANUARY - DECEMBER 2018 Manual 1 was revised on September 28, 2020.

Several procedures were reissued with no changes as part of the 5-year review cycle.

8.0 CONCLUSION

AND RECOMMENDATIONS The quality control evaluations continue to indicate the dosimetry processing programs at the EDC satisfy the criteria specified in the Quality System Manual. The EDC demonstrated the ability to meet all applicable acceptance criteria.

9.0 REFERENCES

1.

EDC Quality Control and Audit Assessment Schedule, 2020.

2.

EDC Manual 1, Quality System Manual, Rev. 4, September 28, 2020.

Plant: Arkansas Nuclear One Year: 2020 Page 57 of 63 Annual Radiological Environmental Operating Report Page 8 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report TABLE 1 PERCENTAGE OF INDIVIDUAL DOSIMETERS THAT PASSED EDC INTERNAL CRITERIA JANUARY - DECEMBER 2019(1), (2)

Dosimeter Type Number Tested

% Passed Bias Criteria

% Passed Precision Criteria Panasonic Environmental 72 100 100 (1)This table summarizes results of tests conducted by EDC.

(2)Environmental dosimeter results are free in air.

TABLE 2 MEAN DOSIMETER ANALYSES (N=6)

JANUARY - DECEMBER 2019(1), (2)

Process Date Exposure Level Mean Bias %

Standard Deviation Tolerance Limit +/-

15%

4/28/2020 37 1.8 1.2 Pass 5/02/2020 94 2.9 1.4 Pass 5/20/2020 56

-0.5 1.4 Pass 7/28/2020 72 4.1 0.6 Pass 8/07/2020 111 4.0 1.3 Pass 9/24/2020 25

-4.6 1.2 Pass 10/24/2020 35 5.2 1.6 Pass 10/28/2020 60 1.6 0.7 Pass 11/18/2020 91 0.5 1.6 Pass 01/21/2021 31 3.8 1.7 Pass 02/09/2021 83 0.3 0.8 Pass 02/16/2021 46 5.3 1,5 Pass (1)This table summarizes results of tests conducted by EDC for TLDs issued in 2020.

(2)Environmental dosimeter results are free in air.

Plant: Arkansas Nuclear One Year: 2020 Page 58 of 63 Annual Radiological Environmental Operating Report Page 9 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report TABLE 3

SUMMARY

OF INDEPENDENT DOSIMETER TESTING JANUARY - DECEMBER 2019(1), (2)

Issuance Period Client Mean Bias %

Standard Deviation %

Pass / Fail 1st Qtr. 2020 Millstone

-3.8 3.0 Pass 2nd Qtr.2020 Seabrook 0.5 1.4 Pass 2nd Qtr.2020 Millstone

-3.0 1.6 Pass 3rd Qtr. 2020 Millstone 0.4 2.6 Pass 4th Qtr.2020 PSEG(PNNL)

-3.2 0.9 Pass 4th Qtr.2020 Seabrook 6.9 1.9 Pass 4th Qtr.2020 SONGS

-8.4 1.3 Pass 4th Qtr.2020 Millstone 3.0 1.9 Pass (1) Performance criteria are +/- 15%.

(2) Blind spike irradiations using Cs-137

Plant: Arkansas Nuclear One Year: 2020 Page 59 of 63 Annual Radiological Environmental Operating Report Page 10 of 14 Environmental Dosimetry Company Interlaboratory Comparison Program Report APPENDIX A DOSIMETRY QUALITY CONTROL TRENDING GRAPHS ISSUE PERIOD JANAURY - DECEMBER 2019

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