ML24107A887

From kanterella
Jump to navigation Jump to search
2023 Annual Radiological Environmental Operating Report (AREOR)
ML24107A887
Person / Time
Site: Grand Gulf Entergy icon.png
Issue date: 04/16/2024
From: Hardy J
Entergy Operations
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
GNRO2024-00009
Download: ML24107A887 (1)
v • d • e


Text

Entergy Operations, Inc.

E) entergy P.O Box 756 Port G ibson, Mississippi 39150

Jeffery Hardy Manager Regu lato ry Assur ance G rand Gulf Nu clea r Sta tion Tel: 802-38 0-5124

GGNS TS 5.6.2

GNRO2024-00009

April 16, 2024

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

SUBJECT:

Grand Gulf Nuclear Station Annual Radiological Environmental Operating Report (AREOR)

Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29

In accordance with Grand Gulf Nuclear Station Unit 1 Technical Specification 5.6.2, attached is the Annual Radiological Environmental Operating Report (AREOR) for the time-period of January 1, 2023 through December 31, 2023.

There are no commitments contained in this submittal. If you have any questions or need additional information, please contact me at 802-380-5124.

Sin~,J~

JH/ram

Attachment:

1, Annual Radiological Environmental Operating Report GNRO2024-00009 Page 2 of 2

cc: NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Attachment 1

GNRO2024-00009 Annual Radiological Environmental Operating Report

} entergy

Plant: Grand Gulf Nuclear Station Page 1 of 59 YEAR: 2023 Document Number: GNRO 2024-00009 Annual Radiological Environmental Operating Report Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 2 of 59 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

.......................... 21

ATTACHMENTS

- Sample Deviations........................................................................................................ 28

- Monitoring Results Tables............................................................................................ 29

- lnterlaboratory Comparison Program Results...............................................................44 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 3 of 59 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 Grand Gulf Nuclear Station (GGNS) Radiological Environmental Monitoring Program (REMP) for the period January 1 through December 31, 2023. This report fulfills the requirements of Grand Gulf Nuclear Station Technical Specification 5.6.2.

All required lower limit of detection (LLD) capabilities were achieved in all sample analyses during 2023, as required by the GGNS Offsite Dose Calculation Manual (ODCM) Specifications Table 6.12.1-3. No measurable levels of radiation above reporting levels for radioactivity as outlined in ODCM Specifications Table 6.12.1-2 were detected in the vicinity of GGNS. The 2023 Radiological Environmental Monitoring Program thus substantiated the adequacy of source control and effluent monitoring at GGNS, with impacts of plant operations to the environment within regulatory limits.

GGNS established the REMP in 1978 prior to the station's becoming operational (1985) to provide data on background radiation and radioactivity normally present in the area. GGNS has continued to monitor the environment by sampling air, water, sediment, fish and food products, as well as measuring direct radiation. GGNS also samples milk if milk-producing animals, used for human consumption, are present within five miles (8 km) of the plant. According to the 2022 Land Use Census, there are no milk producing animals.

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. GGNS personnel compare indicator results with control and preoperational results to assess any impact GGNS operation might have had on the surrounding environment.

In 2023, 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 GGNS operation and effect on the area around the plant. The review of 2023 data showed radioactivity levels in the environment were undetectable in many locations and near background levels in significant pathways.

1.2 Reporting Levels

When averaged over any calendar quarter, no environmental samples equaled or exceeded reporting levels for radioactivity as outlined in ODCM Specifications Table 6.12.1-2 ; the analytical results did not trigger any Radiological Monitoring Program Special Reports.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 4 of 59 Annual Radiological Environmental Operating Report

1.3 Comparison to State and/or Federal Program

GGNS 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 Mississippi State Department of Health (MSDH), Division of Radiological Health monitoring program.

The NRC TLD Network Program was discontinued in 1998. Historically these results have compared to those from the GGNS REMP. GGNS 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 MSDH and the GGNS 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 2023, environmental sampling was performed for 5 media types addressed in the ODCM and for direct radiation. A total of 603 of the 604 scheduled samples were obtained. Of the scheduled samples, 99 percent 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

There were no program modifications during the reporting period.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 5 of 59 Annual Radiological Environmental Operating Report

2.0 INTRODUCTION

2.1 Radiological Environmental Monitoring Program

GGNS 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 GGNS.
  • 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 GGNS ODCM Table 6. 12.1-1. 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 2023 sampling results with Section 5.0 providing a summary of results for the monitored exposure pathways.

2.3 Land Use Census

GGNS conducts a land use census biennially, as required by Section 6.12.2 of the ODCM. The purpose of this census is to identify changes in uses of land within five miles of GGNS that would require modifications to the REMP and the ODCM. The most important criteria during this census are to determine the location in each sector of the nearest occupied residence, unoccupied residence, garden, and milking animal.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 6 of 59 Annual Radiological Environmental Operating Report

3.0 RADIOLOGICAL ENVIRONMENTAL SAMPLING PROGRAM REQUIREMENTS

Table 1, Exposure Pathway - Airborne

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Distance and Direction Frequency Analyses

RADIOIODINE AND PARTICULATES AS-7 (Sector H, 0.5 miles) -

1 sample close to the SITE BOUNDARY South-southeast of GGNS at the IBEW U nion Hall having the highest calculated annual average ground level D/Q.

RADIOIODINE AND PARTICULATES AS-1 (Sector G, 5.5 miles) -

  • Radioiodine Canisters 131 analysis every 7 days 1 sample from the vicinity of a community Southeast of GGNS at the Po rt Gibson C ity Ba rn
  • Air Particulate - Gross beta radioactivity analysis having the highest calculated annual average 7 days, or more frequen tly if following filter change ground level D/Q. required by dus t loading. Air
  • Particulate - Gamma Isotopic composite (by RADIOIODINE AND PARTICULATES AS-20 (Sector L, 0.9 miles) - location) every 92 days 1 sample from the vicinity of a community South-southeast o f GGNS at having the highest calculated annual average the fo rmer Glodjo residence ground level D/Q.

RADIOIODINE AND PARTICULATES AS-3 (Sector B, 18 miles)-

1 sample from a control location 15 - 30 km North of the V icksburg A irport d istance.

Plant: Grand Gulf Nuclear Station l Year: 2023 l Page 7 of 59 Annual Radiological Environmental Operating Report

Table 2, Exposure Pathway - Direct Radiation

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Distance and Direction Frequency Analyses

TLDS

  • M-16 (Sector A, Radius 0.9 An inner ring of stations in the general areas Miles) - Meteorological Tower. 92 days Gamma dose ; 92 days of the SITE BOUNDARY.
  • M-19 (Sector E, Radius 0.5 Miles) - Eastern SITE BOUNDARY Property line, North-northeast of HWSA.
  • M-21 (Sector J, Radius 0.4 Miles) - Near Former Training Center Building on Bald Hill Road.
  • M-22 (Sector G, Radius 0.5 Miles) - Former RR Entrance

Crossing On Bald Hill Road.

  • M-23 (Sector Q, Radius 0.5 Miles) - Gin Lake Road 50 Yards North of Heavy Haul Road on Power Pole.
  • M-25 (Sector N, Radius 1.6 Miles)-Radial Well Number 1.
  • M-28 (Sector L, Radius 0.9 Miles) - Bald Hill Road.
  • M-94 (Sector R, Radius 0.8 Miles) - Sector R Near

Meteorological Tower.

  • M-95 (Sector F, Radius 0.5 mi) -Spoils Area, fence of old storage

area, near entrance gate Plant: Grand Gulf Nuclear Station I Year: 2023 l Page 8 of 59 Annual Radiological Environmental Operating Report

Table 2, Exposure Pathway - Direct Radiation

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Distance and Direction Frequency Analyses

TLDS

  • M-96 (Sector B, Radius 0.7 mi.) -

An inner ring of stations in the general areas North Gate Fence 92 days Gamma dose ; 92 days of the SITE BOUNDARY.

  • M-97 (Sector D, Radius 0.8 mi.) -

Grand Gulf Road entrance gate to spoils area

  • M-98 (Sector H, Radius 0.5 mi.) -

Bald Hill Road, across from Union Hall, in curve

  • M-99 (Sector K, Radius 0.4 mi.) -

North Fence of old Ball Field near utility pole

  • M-100 (Sector C, Radius 0.6 mi.)

- Grand Gulf Road Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 9 of 59 Annual Radiological Environmental Operating Report

Table 2, Exposure Pathway - Direct Radiation

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Distance and Direction Frequency Analyses

TLDS

  • M-36 (Sector P, Radius 5.0 An outer ring of stations approximately 3 to 5 Miles) - Curve on HW 608, Point 92 days Gamma dose; 92 days miles from the site. Nearest GGNS at Power Pole.
  • M-40 (Sector M, Radius 2.3 Miles) - Headly Drive, Near River Port Entrance.
  • M-48 (Sector K, Radius 4.8 Miles) - 0.4 Miles South on Mont

Gomer Road on West Side.

  • M-49 (Sector H, Radius 4.5 Miles) - Fork in Bessie Weathers

Road/Shaifer Road.

  • M-50 (Sector B, Radius 5.3 Miles) - Panola Hunting Club Entrance.
  • M-55 (Sector D, Radius 5.0 Miles) - Near lnge lside Karnac

Ferry Road/Ash land R o ad Intersection.

  • M-57 (Sector F, Radius 4.5 Miles) - Hwy 61, Beh ind the

We lcome to P o rt Gibson Sign at G le n sda le Subd iv ision.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 10 of 59 Annual Radiological Environmental Operating Report

Table 2, Exposure Pathway - Direct Radiation

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Distance and Direction Frequency Analyses

TLDS

  • M-01 (Sector E, Radius 3.5 Additional stations in special interest areas Miles) -Across the road from 92 days Gamma dose; 92 days such as population centers, nearby Lake Claiborne Entry Gate.

residences, schools, and in 1 or 2 areas to (Special) serve as control locations.

  • M-07 (Sector G, Radius 5.5 Miles) -AS-1 PG, Port Gibson C ity Barn. (Specia l)
  • M-09 (Sector D, Radius 3.5 Miles) - Warner Tully Y-Camp.

(Special)

  • M-10 (Sector A, Radius 1.5 Miles) - Grand Gulf Military Park.

(Specia l)

  • M-14 (Sector B, Radius 18.0 Miles)- AS 61VA, Hwy 61,

North of Vicksburg Airport.

(Control)

  • M-33 (Sector P, Radius 12.5 Miles) - Newellton, Louisiana

Water Tower. (Control)

  • M-38 (Sector M, Radius 9.5 Miles) - Lake Bruin State Park,

Entrance Road. (Special)

  • M-39 (Sector M, Radius 13.0 Miles) - St. Joseph, Louisiana,

Auxiliary Water Tank. (Special)

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 11 of 59 Annual Radiological Environmental O~rating ~Report

Table 3, Exposure Pathway - Waterborne

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Analyses Distance and Direction Frequency

  • MRUP (Sector R, Radius 1.8 Miles) - At least 4500 ft upstream 92 days Gamma isotopic and tritium analysis; 92 days of the GGNS discharge point into SURFACE WATER the Mississippi River to allow 1 sample upstream and 1 sample adequate mixing of the Mississippi downstream. and Big Black Rivers.
  • MRDOWN (Sector N, Radius 1.6 Miles) - At least 5000 ft downstream of the GGNS d ischarge p oint in the Mississippi River near Rad ia l We ll No. 1.
  • MRDOWN (Sector P, Radius 1.3 1 samp le downstream d ur ing a Liquid Miles) - Do wnstream o f the Radwaste Discharge. GGNS d ischarge p oint in the 366 days Gamma isotopic and tritium ana lysis; 366 d ays M ississipp i R iver n ear Radial Well No. 5.

1 sample from Outfa ll 007

  • OUTFALL 007 (Sector N, Radius 31 days Tritium; 31 days 0.2 Miles)- Storm Dra in System
  • PGWELL (Sector G, Radius 5.0 Miles) - Po rt Gibs o n We lls - 366 days Gamma isotopic and tritium analysis ; 366 days Taken fro m d istribut ion system or GROUNDWATER o ne o f the five we lls.

Samples from 2 sources

  • CONSTWELL (Sector Q, Radius 0.4 Miles) - GGNS C on struction Water We ll - Taken from d istrib u tion system or the well.

Plant: Grand Gulf Nuclear Station J Year: 2023 J Page 12 of 59 Annual Radiological Environmental Operating Report

Table 3, Exposure Pathway - Waterborne

Requirement Sample Point Description Sampling and Collection Type and Frequency Of Distance and Direction Frequency Analyses

SEDIMENT FROM SHORELINE

  • SEDHAM (Sector N, Radius 1.6 1 sample from downstream area and 1 Miles) - Downstream of the 366 days Gamma isotopic; 366 days sample from upstream area Mississippi GGNS discharge point in the River near Ham ilton Lake outlet.
  • SEDCONT (Minimum of 100 yds) - Upstream of the GGNS

discharge point in the Mississippi River.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 13 of 59 Annual Radiological Enyironmental Operating R~ort

Table 4, Exposure Pathway - Ingestion

Requirement Sample Point Description Distance Sampling and Collection Type and Frequency Of and Direction Frequency Analyses

MILK

  • If commercially available, 1 sample from
  • Currently, no available milking anim als 92 days when required Gamma isotopic and 1-131; 92 days milking animals within 8 km distant within 8 km of GGNS.
  • 1 sample from milking animals at a
  • ALCONT (Sector K, Radius 10.5 control location >8 km distant when an Miles) - Located South-southwest of indicator location exists. GGNS at Alcorn State University.

(Control)

FISH AND INVERTEBRATES

  • FISHDOWN - Downstream of the
  • 1 sample in vicinity of GGNS discharge GGNS discharge point into the 366 days Gamma isotopic River on edible portions; 366 days point. Mississippi
  • 1 sample uninfluenced by GGNS discharge point into the
  • FISHUP - Upstream of the GGNS discharge. River M ississippi uninfluenced by plant operations.

FOOD PRODUCTS

  • VEG-J (Sector J, Radius 0.4 Miles) -
  • 1 sample of broadleaf vegetation grown in South of GGNS near former Training 92 days when available Gamma isotopic and 1-131; 92 days one of two different offsite locations with Center on Bald Hill Road.

highest anticipated annual average

  • VEG-CONT (Sector K, Radius 10.5 ground level D/Q if milk sampling is not Miles) - Alcorn State University south-performed. southwest of GGNS when available,
  • (Control) 1 sample of similar vegetation grown 15-otherwise a location 15-30 km distant.

30 km distant if milk sampling is not performed.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 14 of 59 Annual Radiological Environmental Operating Report

Figure 1, Exposure Pathway

NUCLEAR POWER PLANT

~

LIQUID EFFLUENT

0.rtct I

/.ldi1tion *..

~EL TRANSPORT

-...:. j Cl,

~ -- -\\ ~ -~

Exposure pathways to man Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 15 of 59 Annual Radiological Environmental Operating Report

Figure 2, Sample Collection Sites -Near Field Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 16 of 59 Annual Radiological Environmental Operating Report

Figure 3, Sample Collection Sites - Far Field Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 17 of 59 Annual Radiological Environmental Operating Report

4.0 INTERPRETATION AND TRENDS OF RESULTS

4.1 Air Particulate and Radioiodine Sample Results

GGNS did not detect any plant related gamma emitting radionuclides in the quarterly air particulate composites. The REMP had previously detected airborne radioactivity attributable to other sources in this pathway. These sources include the Chinese nuclear test in 1980 and the accident at the Chernobyl Nuclear Power Plant in 1986.

The GGNS REMP detected radioactivity released from the Fukushima Dai-ichi Nuclear Power Plant following the March 11, 2011, Tohoku earthquake.

In 2023 there were no samples above the LLD for 1-131. Indicator gross beta air particulate results for 2023 were comparable to results obtained from 2013-2022 of the operational REMP. Also, the 2023 gross beta annual average was less than the average for preoperational levels. Results are reported as annual average picocuries per cubic meter (pCi/m 3).

Monitoring Period Result 2013 - 2022 (Minimum Value) 0.008 2023 Average Value 0.024 2013 - 2022 (Maximum Value) 0.040 Preoperational 0.032

In the absence of plant-related gamma radionuclides, gross beta activity is attributed to naturally occurring radionuclides. Table 7, which include gross beta concentrations and provide 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 Grand Gulf Nuclear Station operations.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 18 of 59 Annual Radiological Environmental Operating Report

4.2 Thermoluminescent Dosimetry (TLD) Sample Results

Grand Gulf Nuclear Station 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. Grand Gulf Nuclear Station's comparison of the inner ring and special interest area TLD results to the control, as seen in Table 7, 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 10.0 millirem/quarter (mR/Qtr) shown in Table 7 for 2023 is within the historical bounds of 2013 -2022 annual average results, which have ranged from 9.3 to 10.0 mrem. Overall, Grand Gulf Nuclear Station concluded that the ambient radiation levels are not being affected by plant operations.

Table 5, Direct Radiation Annual Summary

Year Inner Ring (mR/Qtr) Outer Ring (mR/Qtr) Control Location (mR/Qtr)

2013 9.8 9.7 10.8 2014 10.0 9.9 11.0

2015 9.6 9.5 10.8

2016 9.3 9.3 10.7

2017 9.9 9.9 11.3

2018 9.7 9.8 10.6

2019 10.0 9.7 10.7

2020 9.6 9.4 10.7 2021 9.9 10.2 11.7

2022 9.6 9.7 10.8

2023 10.0 10.1 11.2

4.3 Waterborne Sample Results

Analytical results for 2023 surface water and drinking water samples were similar to those reported in previous years. Gamma radionuclides analytical results for 2023 surface water samples were similar to those reported in previous years. Tritium detected in Grand Gulf Nuclear Station surface water indicator samples is attributed to washout and entrainment of normal, previously monitored gaseous effluents.

4.3.1 Surface Water

Samples were collected from two indicator locations (Outfall 007, MRDOWN) and one control location (MRUP) and analyzed for gamma emitting radionuclides and tritium. Plant related gamma emitting radionuclides and tritium remained undetectable in the upstream and downstream Mississippi River locations, which is consistent with previous operational years.

Storm waters contribute to Outfall 007 and can include tritium as a result of washout and entrainment of normal, previously monitored gaseous effluents. As a result, tritium is Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 19 of 59 Annual Radiological Environmental Operating Report

occasionally observed. Tritium was measured during January (736 pCi/L) and December (9,620 pCi/L) at the Outfall 007 location. Tritium was not observed in the remaining Outfall 007 samples collected during 2023. Results are reported as annual average pCi/1.

Monitoring Period Result 2013-2022 (Minimum Value) 347 2023 Average Value 5072 2013 - 2022 (Maximum Value) 24600 Preoperational 2739

Grand Gulf Nuclear Station personnel have noted no definable increasing trends associated with the tritium levels at the discharge location (Outfall 007). Levels detected during 2023 and previous operational years have remained below regulatory limits. Therefore, the operation of Grand Gulf Nuclear Station had no definable impact on this waterborne pathway during 2023 and levels of radionuclides remain similar to those obtained in previous operational years.

4.3.2 Drinking Water

Drinking water samples were collected from two locations, CONSTWELL (indicator) and PGWELL (control). Drinking water samples were analyzed for 1-131, gamma radionuclides and tritium. During 2023, gamma radionuclides, 1-131, and tritium concentrations were below the LLD limits at the indicator and control locations, which is consistent with previous operational years. Results are reported as annual average pCi/L.

Radionuclide 2023 2013-2022 Preoperational Gross Beta < LLD < LLD <LLD lodine-131 < LLD < LLD < LLD Gamma < LLD < LLD < LLD Tritium < LLD < LLD <LLD

Grand Gulf Nuclear Station personnel have noted no definable trends associated with drinking water results at the indicator location. Therefore, the operation of Grand Gulf Nuclear Station had no definable impact on this waterborne pathway during 2023 and levels of radionuclides remain similar to those obtained in previous operational years.

Results from 2023 are summarized in Table 7.

4.3.3 Groundwater

Groundwater monitoring data collected during administration of the Groundwater Protection Initiative (GPI) site program are included in the Annual Radioactive Effluent Release Report.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 20 of 59 Annual Radiological Environmental Operating Report

4.4 Soil Sample Results

Sediment samples were collected from two locations in 2023 and analyzed for gamma radionuclides. Listed below is a comparison of 2023 indicator results to the 2013 - 2022 operational years. Grand Gulf Nuclear Station operations had no significant impact on the environment or public by this waterborne pathway. Results are reported as pCi/kg.

Monitoring Period Result 2013 - 2022 (Minimum Value) <LLD 2023 Value < LLD 2012 - 2022 (Maximum Value) 39.9 Preoperational 295.0

4.5 Ingestion Sample Results

4.5.1 Milk Sample Results

Milk samples were not collected during 2023 due to the unavailability of indicator locations within five miles of Grand Gulf Nuclear Station.

4.5.2 Fish Sample Results

Fish samples were collected from two locations and analyzed for gamma radionuclides. In 2023, gamma radionuclides were below detectable limits which are consistent with preoperational and operational years. Therefore, based on these measurements, Grand Gulf Nuclear Station 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 2023, food product samples were collected from two locations and analyzed for plant related lodine-131 and gamma radionuclides. The 2023 levels remained undetectable, as has been the case in previous years. Therefore, based on these measurements, Grand Gulf Nuclear Station operations had no significant radiological impact upon the environment or public by this ingestion pathway.

4.6 Land Use Census Results

The latest land use census, performed in 2022, did not identify any new locations that yielded a calculated dose or dose commitment greater than those currently calculated.

The land use census identified no milk-producing animals within a five-mile radius of the plant site. In accordance with ODCM Section 6.12.1, Grand Gulf Nuclear Station personnel sampled broadleaf vegetation.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 21 of 59 Annual Radiological Environmental Operating Report

Table 6, Land Use Census - 2022 Nearest Residence Within Five Miles

Sector Direction Nearest Residence (miles) Nearest Garden (miles)

A N 1.02 none w ithin 5 m iles

8 NNE 1.51 1.52

C NE 0.70 none w ithin 5 m iles D ENE 2.60 4.50

E E 0.83 0.91

F ESE 2.25 none w ithin 5 m iles

G SE 3.72 4.20

H SSE 1. 10 4.31 J s 3. 14 none w ithin 5 m iles K SSW 2.20 2. 18

L SW 0.89 0.89

M WSW none w ithin 5 miles none within 5 miles N w none within 5 m iles none w ithin 5 miles p WNW none within 5 miles none w ithin 5 miles a NW none within 5 miles none within 5 miles

R NNW 1.44 none w ithin 5 m iles

The next land use census is scheduled to be conducted in 2024.

4.7 lnterlaboratory Comparison Results

Teledyne Brown Engineering and Stanford Dosimetry analyzed interlaboratory comparison samples to fulfill the requirements of ODCM Specification 6. 12.1. The results are shown in Attachment 3.

5.0 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

1. Table 7, Radiological Environmental Monitoring Program Summary, summarizes data for the 2023 REMP program.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 22 of 59 Annual Radiologica! Envirqnmental Operating Report

Table 7, Radiological Environmental Monitoring Program Summary

Location with the Highest Annual Control Sample Type Type/ Number Indicator Locations Mean Locations Number of (Units) of Analyses LLD (Note2] Mean (F)[Note 3] Mean (F)(Note 3] Non-Routine [Note 1) [Range] Mean (F)[Note 3) Results [Note SJ Location [Note 41 [Range] [Range]

GB I 208 0.01 0.0241 (156/ 156) AS-20 GR 0.0245 (52 I 52 ) 0.0250 (52 I 52) 0 Air [0.0095 - 0.0505] (Sector L, 0.9 mi) [0.0108 - 0.0472] [0.0109 - 0.0445]

Particulates GS/ 16 (pCi/m 3 ) Cs-134 0.05 <LLD NIA NIA <LLD 0 CS-137 0.06 <LLD NIA NIA <LLD 0

Airborne 1-131 / 208 0.07 < LLD NIA NIA < LLD 0 Iodine (pCi/ m 3 )

Inner Ring Gamma / 55 [Note6] 10.0 (55 / 55) M-99 12.9 (4 / 4 ) NIA TLDs (mR/Qtr) 0 [6.7 -14.6] (Sector K, 0.4 mi.) [11.7 -14.6]

Outer Ring Gamma/ 28 [Note6] 10. 1 (28 / 28) M-57 12.2 (4 I 4) NIA 0 TLDs (mR/Qtr) [5.5 - 13.3] (Sector F, 4.5 mi.) [11.1-13.3]

Special Interest TLDs Gamma/ 28 [Note6] 10.4 (28 I 28) M-01 11.7(4/4) NIA 0 (mR/Qtr) [8.1 -12.6] (Sector E, 3.5 mi.) [10.9 - 12.6 ]

Control TLD Gamma/ 4 [Note6] NIA NIA NIA 11.2(4/4) 0 (mR/Qtr) [10.3-12.7]

Plant: Grand Gulf Nuclear Station J Year: 2023 J Page 23 of 59 Annual Radiological Environmental Operating Report

Table 7, Radiological Environmental Monitoring Program Summary

Location with the Highest Annual Control Sample Type Type/ Number Indicator Locations Mean Locations Number of (Units) of Analyses LLD (Note2] Mean (F)[Note 3] Mean (F)[Note 31 Non-Routine [Note 1) [Range] Mean (F)INote 31 Results [Note SJ Location (Note 41 [Range] [Range)

H-3 / 42 3000 5072 (4 / 42) Outfall 007 5072 (4/ 24 ) < LLD 0

[651 - 9620] (Sector N, 0.2 mi.) [651 - 9620]

GS I 18 Mn-54 15 < LLD N/A N/A < LLD 0 Fe-59 30 < LLD N/A NIA < LLD 0 Co-58 15 < LLD N/A N/A < LLD 0 Surface Water Co-60 15 < LLD N/A N/A < LLD 0 (pCi/1) Zn-65 30 < LLD N/A N/A < LLD 0 Zr-95 30 < LLD N/A N/A < LLD 0 Nb-95 15 < LLD N/A N/A < LLD 0 1-131 15 < LLD N/A N/A < LLD 0 Cs-134 15 < LLD N/A N/ A < LLD 0 Cs-137 18 < LLD N/A N/A < LLD 0 Ba-140 60 < LLD N/A N/A < LLD 0 La-140 15 < LLD N/A N/A < LLD 0 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 24 of 59 Annual Radiological Environmental Operating Report

Table 7, Radiological Environmental Monitoring Program Summary

Location with the Highest Annual Control Sample Type Type/ Number Indicator Locations Mean Locations Number of of Analyses LLD [Note2] Mean (F)!Note 31 Non-Routine (Units) [Note 1] [Range] Mean (F)[Note 3] Mean (F)[Note 31 Results [Note SJ Location [Note 41 [Range] [Range]

1-13114 1 < LLD NIA NIA < LLD 0

H-314 2000 < LLD NIA NIA < LLD 0

GS I 4 Mn-54 15 < LLD NIA NIA < LLD 0 Fe-59 30 < LLD NIA NIA < LLD 0 Drinking Water Co-58 15 < LLD NIA NIA < LLD 0 (pCi/1) Co-60 15 < LLD NIA NIA < LLD 0 Zn-65 30 < LLD NIA NIA < LLD 0 Zr-95 30 < LLD NIA NIA < LLD 0 Nb-95 15 < LLD NIA NIA < LLD 0 Cs-134 15 < LLD NIA NIA < LLD 0 Cs-137 18 < LLD NIA NIA < LLD 0 Ba-140 60 < LLD NIA NIA < LLD 0 La-140 15 < LLD NIA NIA < LLD 0

Sediment GSl4 Cs-134 150 < LLD NIA NIA NIA 0 (pCi/kg) Cs-137 180 < LLD NIA NIA NIA 0 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 25 of 59 Annual Radiological Environmental Operating Report

Table 7, Radiological Environmental Monitoring Program Su 'mmary

Location with the Highest Annual Control Sample Type Type/ Number Indicator Locations Mean Locations Number of 3) Mean (F)INote (Units) of Analyses LLD [Note2) Mean (F)[Note [Note 1) [Range] Mean (f)[Note 31 Non-Routine Location [Note 41 [Range] [Range] 3) Results [Note SJ

GS/4 Mn-54 130 < LLD N/A N/A < LLD 0 Fe-59 260 < LLD N/A N/A < LLD 0 Fish (pCi/kg) Co-58 130 < LLD N/A N/A < LLD 0 Co-60 130 < LLD N/A N/A < LLD 0

Zn-65 260 < LLD N/A N/A < LLD 0 Cs-134 130 < LLD N/A N/A < LLD 0 Cs-137 150 < LLD N/A N/A < LLD 0

1-131 / 12 60 < LLD N/A N/A N/A 0 Food Products GS/ 12 (pCi/kg) Cs-134 60 < LLD N/A N/A N/A 0 Cs-137 80 < LLD N/A N/A N/A 0 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 26 of 59 Annual Radiological Environmental Operating Report

Table 7, Radiological Environmental Monitoring Program Summary

Location with the Highest Annual Control Sample Type Mean Number of Type/ Number Indicator Locations (Units) [Note 1] Mean (F)[Note 3] Non-Routine of Analyses LLD [Note2] Mean (F)[Note 3] Locations

[Range] Mean (F)[Note 3] Results [Note 51 Location [Note 41

[Range] [Range)

GS/8 Mn-54 15 < LLD N/A N/A < LLD 0 Fe-59 30 < LLD N/A N/A < LLD 0 Co-58 15 < LLD N/A N/A < LLD 0 Co-60 15 < LLD N/A N/A < LLD 0 Surface Water Zn-65 30 < LLD N/A N/A < LLD 0 (Special) Zr-95 30 < LLD N/A N/A < LLD 0 (pCi/1) Nb-95 15 < LLD N/A N/A < LLD 0 1-131 15 < LLD N/A N/A < LLD 0

Cs-134 15 < LLD N/A N/A < LLD 0 Cs-137 18 < LLD N/A N/A < LLD 0 Ba-140 60 < LLD N/A N/A < LLD 0 La-140 15 < LLD N/A N/A < LLD 0 Plant: Grand Gulf Nuclear Station l Year:2023 I Page 27 of 59 Annual Radiological Environmental Operating Report

Table 7, Radiological Environmental Monitoring Program Summary

Location with the Highest Annual Control Sample Type Type/ Number Indicator Locations Mean Locations Number of (Units) [Note 1] [Range] Mean (F)INote 31 of Analyses LLD [Note2] Mean (F)(Note 3] Mean (F)[Note 3] Non-Routine Location [Note 41 [Range] [Range] Results [Note 51

GS/ 1 Mn-54 130 < LLD N/A N/A < LLD 0 Meat Fe-59 260 < LLD N/A N/A < LLD 0 (Special) Co-58 130 < LLD NIA N/A < LLD 0 (pCi/kg) Co-60 130 < LLD N/A N/A < LLD 0 Zn-65 260 < LLD N/A N/A < LLD 0 Cs-134 130 < LLD N/A N/A < LLD 0 Cs-137 150 < LLD N/A N/A < LLD 0

LEGEND:

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

[Note 2] - LLD= Required lower limit of detection based on ODCM Table 6.12.1-3.

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

[Note 4] - Where applicable, locations are specified (1) by name, (2) distance from reactor site, and (3) meteorological sector.

[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 ODCM Table 6.12.1-3.

Plant: Grand Gulf Nuclear Station l Year: 2023 I Page 28 of 59 Annual Radiological Environmental O_eerating Report Attachment 1 Page 1 of 1 Sample Deviations

Table 8, Sample Deviations Table

Comment Sample Sample Media Date Problem Evaluation I Actions No. Affected Location

During collection of 1st quarter 2023 TLDs, monitoring location M-96 1 TLD M-96 03/30/23 TLD Lost could not be located. Field observation indicated the TLD may have been lost when a fallen tree damaged the pole it was attached to.

CR-GGN-2023-01972 documents the condition.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 29 of 59 Annual Radiological Environmental Operating Report Page 1 of 15 Monitoring Results Tables

Table 9, Air Particulate Data Summary Table

Analysis: Gross Beta I Units: pCi/m 3

Station Station Station Station Start Date End Date AS-1 AS-7 AS-20 AS-3 [Note 1)

(Indicator) (Indicator) (Indicator) (Control)

REQUIRED LLD -+ 0.01 0.01 0.01 0.01

12/ 27 /22 01 / 03 /23 0.0157 0.0166 0.0178 0.0184 01 / 03 /23 01 / 10/23 0.0196 0.0184 0.0201 0.0195 01 / 10/23 01 / 17/23 0.0273 0.0280 0.0301 0.0283 01 / 17/23 01 /24 / 23 0.0181 0.0157 0.0222 0.0191 01 / 24 /23 01 / 31 /23 0.0146 0.0197 0.0128 0.0161 01 / 31 /23 02/ 07 / 23 0.0201 0.0219 0.0203 0.0232 02 / 07 /23 02 / 14/23 0.0203 0.0188 0.0163 0.0245 02 / 14/23 02 /21 / 23 0.0177 0.0141 0.0183 0.0172 02/21 /23 02 /28 /23 0.0198 0.0193 0.0206 0.0194 02/28/23 03 / 07 /23 0.0212 0.0175 0.0194 0.0174 03/07/23 03 / 14/23 0.0239 0.0216 0.0209 0.0251 03/14 /23 03 /21 /23 0.0208 0.0241 0.0233 0.0200 03 / 21 /23 03/ 28 /23 0.0223 0.0247 0.0225 0.0250 03/28 /23 04/04 /23 0.0240 0.0253 0.0239 0.0246 04 / 04/23 04/ 11 / 23 0.00952 0.00976 0.0108 0.0109 04/ 11 /23 04/ 18/23 0.0135 0.0141 0.0164 0.0174 04/18 /23 04/25 / 23 0.0209 0.0194 0.0228 0.0214 04/25 /23 05/02 /23 0.0195 0.018 0.0178 0.0205 05/02 /23 05/09 / 23 0.0222 0.0182 0.0174 0.0228 05 / 09 /23 05 / 16/23 0.0226 0.0233 0.0190 0.0216 05 / 16/23 05 /23 /23 0.0208 0.0192 0.0229 0.0234 05/23 /23 05 / 30 /23 0.0249 0.0278 0.0267 0.0258 05/30/23 06 / 06 /23 0.0216 0.0267 0.0236 0.0274 06/06 /23 06 / 13/ 23 0.0242 0.0265 0.0270 0.0282 06/ 13/23 06 /20 /23 0.0152 0.0182 0.0172 0.0243 06 /20 /23 06 /27 /23 0.0206 0.0193 0.0211 0.0200 06/27 /23 07/ 04 /23 0.0212 0.0219 0.0229 0.0258 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 30 of 59 Annual Radiological Environmental Operating Report Page 2 of 15 Monitoring Results Tables

Table 9, Air Particulate Data Summary Table

Analysis: Gross Beta I Units: pCi/m 3

Station Station Station Station Start Date End Date AS-1 AS-7 AS-20 AS-3 (Note 1)

(Indicator) (Indicator) (Indicator) (Control)

REQUIRED LLD ~ 0.01 0.01 0.01 0.01

07/04/23 07/11/23 0.0112 0.0145 0.0143 0.0152 07/11/23 07/18/23 0.0197 0.0211 0.0188 0.0218 07/18/23 07/25/23 0.0278 0.0285 0.0279 0.0293 07/25/23 08/01/23 0.0351 0.0339 0.0359 0.0298 08/01/23 08/08/23 0.0250 0.0230 0.0239 0.0317 08/08/23 08/15/23 0.0186 0.0175 0.0238 0.0216 08/15/23 08/22/23 0.0272 0.0305 0.0319 0.0268 08/22/23 08/29/23 0.0440 0.0377 0.0380 0.0429 08/29/23 09/05/23 0.0276 0.0274 0.0262 0.0296 09/05/23 09/12/23 0.0257 0.0243 0.0266 0.0276 09/12/23 09/19/23 0.0445 0.0440 0.0472 0.0417 09/19/23 09/26/23 0.0340 0.0330 0.0365 0.0329 09/26/23 10/03/23 0.0306 0.0330 0.0303 0.0362 10/03/23 10/10/23 0.0224 0.0232 0.0246 0.0253 10/10/23 10/17/23 0.0208 0.0168 0.0180 0.0183 10/17/23 10/24/23 0.0343 0.0307 0.0337 0.0308 10/24/23 10/31/23 0.0194 0.0197 0.0197 0.0232 10/31/23 11/07/23 0.0289 0.0309 0.0337 0.0261 11/07/23 11/14/23 0.0505 0.0238 0.0236 0.0259 11/14/23 11/21/23 0.0269 0.0272 0.0331 0.0282 11/21/23 11/28/23 0.0426 0.0374 0.0439 0.0445 11/28/23 12/05/23 0.0274 0.0257 0.0306 0.0274 12/05/23 12/12/23 0.0270 0.0243 0.0222 0.0245 12/12/23 12/19/23 0.0235 0.0276 0.0314 0.0249 12/19/23 12/26/23 0.0243 0.0217 0.0223 0.0268

[Note 1]-Station with highest annual mean.

Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 31 of 59 Annual Radiological Environmental Operating Report Page 3 of 15 Monitoring Results Tables

Table 10, Radioiodine Cartridge Data Table Summary

Analysis: 1-131 I Units: pCi/m 3

Start Date End Date AS-1 AS-7 AS-20 AS-3 (Indicator) (Indicator) (Indicator) (Control)

REQUIRED LLD + 0.07 0.07 0.07 0.07

12/27/22 01 / 03 /23 <0.03215 < 0.03159 <0.03274 < 0.0323 01 / 03 /23 01 / 10/23 < 0.04344 <0.04178 <0.04339 <0.04328 01 / 10/23 01 / 17/23 < 0.03374 <0.03166 <0.0339 < 0.03371 01 / 17/23 01 /24 /23 <0.02814 < 0.02657 <0.02842 <0.02719 01 /24 /23 01 /31 /23 < 0.03414 <0.03334 <0.0344 <0.03396 01 / 31 /23 02 / 07 /23 <0.0324 7 <0.03242 <0.03355 < 0.03288 02 /07 / 23 02 / 14/23 <0.02569 <0.02486 <0.02576 <0.02535 02 / 14/23 02 /21 /23 < 0.02976 <0.02895 <0.03 <0.03017 02/21 /23 02 /28 /23 <0.0238 < 0.03524 <0.03651 < 0.03472 02 /28 /23 03 /07/23 <0.03414 <0.03278 <0.03455 <0.03346 03 / 07/23 03 / 14/23 <0.04189 <0.04054 <0.04274 <0.04215 03 / 14/23 03 /21 /23 <0.03362 < 0.03244 <0.03338 <0.0322 03 /21 /23 03/28 /23 < 0.02358 <0.02314 <0.02477 <0.02317 03 /28 /23 04 / 04 /23 < 0.02515 <0.02459 <0.02546 < 0.02474 04/ 04 /23 04 / 11 /23 <0.02434 <0.02401 <0.02469 < 0.02503 04 / 11 /23 04 / 18/23 < 0.05558 <0.05702 <0.05809 <0.05543 04/ 18/23 04 /25 /23 < 0.02761 <0.02763 <0.02804 <0.02776 04 /25 /23 05 / 02 /23 <0.04729 <0.04596 <0.04681 < 0.04645 05 /02 /23 05 /09 /23 < 0.03181 <0.0310 1 <0.03164 < 0.03202 05 / 09 /23 05 / 16/23 < 0.05846 <0.05732 < 0.05907 <0.0572 05/ 16/23 05/23 /23 <0.03556 < 0.03464 <0.03566 < 0.03492 05 /23 /23 05/ 30 /23 <0.03366 <0.01487 <0.03352 <0.03299 05 / 30 /23 06 /06 /23 < 0.04779 <0.01961 <0.04794 <0.04789 06/ 06 /23 06 / 13/23 <0.03231 < 0.03169 <0.03233 < 0.03154 06 / 13/23 06/ 20 / 23 <0.04906 <0.06347 <0.0649 < 0.03955 06 /20/23 06 /27 /23 <0.03838 <0.0383 <0.03759 <0. 03703 06 /2 7/23 07 / 04 /23 <0.06008 <0.06056 <0.06121 < 0.06099 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 32 of 59 Annual Radiological Environmental Operating Report Page 4 of 15 Monitoring Results Tables

Table 10, Radioiodine Cartridge Data Table Summary

Analysis: 1-131 I Units: pCi/m 3

Start Date End Date AS-1 AS-7 AS-20 AS-3 (Indicator) (Indicator) (Indicator) (Control)

REQUIRED LLD + 0.07 0.07 0.07 0.07

07/04/23 07/11/23 <0.02545 <0.01223 <0.02588 <0.02683 07/11/23 07/18/23 <0.03018 <0.02882 <0.02932 <0.02765 07/18/23 07/25/23 <0.05296 <0.05472 <0.05537 <0.0549 07/25/23 08/01/23 <0.0214 <0.02146 <0.02165 <0.02154 08/01/23 08/08/23 <0.05162 <0.05189 <0.05244 <0.05153 08/08/23 08/15/23 <0.02691 <0.03546 <0.03594 <0.03597 08/15/23 08/22/23 <0.05442 <0.05504 <0.05561 <0.05531 08/22/23 08/29/23 <0.02569 <0.03864 <0.03914 <0.04248 08/29/23 09/05/23 <0.03504 <0.03526 <0.0357 <0.03766 09/05/23 09/12/23 <0.02102 <0.0510 4 <0.05144 <0.05554 09/12/23 09/19/23 <0.01644 <0.03456 <0.03 482 <0.03615 09/19/23 09/26/23 <0.05 401 <0.05303 <0.05336 <0.05315 09/26/23 10/03/23 <0.03908 <0.03819 <0.03855 <0.03847 10/03/23 10/10/23 <0.05006 <0.04958 <0.05028 <0.02053 10/10/23 10/17/23 <0.04485 <0.0 4393 <0.04485 <0.01838 10/17/23 10/24/23 <0.02147 <0.01602 <0.02136 <0.02172 10/24/23 10/31/23 <0.03187 <0.03117 <0.03159 <0.03059 10/31/23 11/07/23 <0.04107 <0.04026 <0.0173 <0.04162 11/07/23 11/14/23 <0.03493 <0.03407 <0.03483 <0.03507 11/14/23 11/21/23 <0.05101 <0.04968 <0.05102 <0.05162 11/21/23 11/28/23 <0.02991 <0.01493 <0.02979 <0.03039 11/28/23 12/05/23 <0.03262 <0.01541 <0.03251 <0.03294 12/05/23 12/12/23 <0.04434 <0.01817 <0.04417 <0.04567 12/12/23 12/19/23 <0.03549 <0.03 426 <0.03522 <0.03539 12/19/23 12/26/23 <0.02066 <0.02006 <0.02057 <0.02102 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 33 of 59 Annual Radiological Environmental Operating Report Page 5 of 15 Monitoring Results Tables

Table 11, Air Gamma Quarterly Composite

Analysis: Gamma Isotopic Units: pCi/cu.m

Location Date CS-134 CS-137

REQUIRED LLD ~ 0.05 0.06

AS-1 < 0.00157 <0.001454 AS-3 <0.001891 <0.001268 AS-7 < 0.002328 <0.002329 02/10/23

AS-20 <0.001842 <0.001648 AS-1 <0.002751 <0.002093 AS-3 <0.002935 <0.002012 05/12/23 AS-7 <0.002445 <0.001362 AS-20 <0.001492 <0.001723 AS-1 <0.001863 <0.001446 AS-3 08/11/23 <0.002374 <0.001628 AS-7 <0.003083 <0.002801 AS-20 <0.002028 <0.001116 AS-1 <0.001938 <0.001825 AS-3 <0.001955 <0.001357 11/10/23 AS-7 <0.001921 <0.001352 AS-20 <0.002886 <0.002129 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 34 of 59 Annual Radiological Environmental Operating Report Page 6 of 15 Monitoring Results Tables

Table 12, Thermoluminescent Dosimeters - Inner Ring

Analysis: Gamma Dose I Units: mrem

Station 1st Qtr 2023 2nd Qtr 2023 3rt1 Qtr 2023 4 th Qtr 2023 Annual Mean 2023

M-16 10.3 10.0 12.1 11.7 11.0

M-19 8.7 9.0 10.4 10.1 9.5

M-21 12.0 11.3 12.4 12.2 12.0

M-22 8.3 7.7 9.0 9.2 8.5

M-23 8.0 8.6 8.8 9.7 8.8

M-25 7.5 6.7 9.4 9.3 8.2

M-28 10.4 10.6 11.9 12.0 11.3

M-94 9.8 9.3 11.6 11.0 10.4

M-95 6.8 10.1 7.9 7.7 8.1 M-96 Lost(Note 2) 6.8 10.8 10.4 9.3

M-97 7.1 9.6 8.0 8.2 8.2

M-98 11.1 7. 1 12.3 12.4 10.8

M-99[No te 1) 12.0 11.7 13.6 14.6 12.9

M-100 9.4 11.8 11.0 12.2 11.1

[Note 1] - Station with highest annual mean.

[Note 2] - Reference Attachment 1, Sample Deviations, Table 8, Sample Deviations Table, Comment 1 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 35 of 59 Annual Radiological Environmental Operating Report Page 7 of 15 Monitoring Results Tables

Table 13, Thermoluminescent Dosimeters - Outer Ring

Analysis: Gamma Dose I Units: mrem

Station 1st Qtr 2023 2nd Qtr 2023 3 rd Qtr 2023 4th Qtr 2023 Annual Mean 2023

M-36 8.4 11.2 9.0 9.4 9.5 M-40 6.0 8.2 6.2 6.9 6.8 M-48 10.2 5.5 11.3 11.2 9.6 M-49 10.8 9.7 11.6 12.1 11.0 M-50 9.2 9.9 11.0 11.4 10.4 M-55 11.3 9.4 11.1 12.4 11.1 M-57 [Nole 1] 11.1 11.1 13.1 13.3 12.2

[Note 1] - Station w ith highest annual mean.

Table 14, Thermoluminescent Dosimeters - Special Interest Areas

Analysis: Gamma Dose I Units: mrem

Station 1st Qtr 2023 2nd Qtr 2023 3rd Qtr 2023 4 th Qtr 2023 Annual Mean 2023

M-01 [No le 1] 11.1 10.9 12.3 12.6 11.7

M-07 9.3 9.8 11.0 10.6 10.2 M-09 9.9 9.1 10.8 10.1 10.0 M-10 8.1 8.8 10.0 9.2 9.0 M-33 11.1 11.2 12.5 12.2 11.8 M-38 8.9 8.3 11.7 10.6 9.9 M-39 8.9 8.6 10.1 10.9 9.7

[Note 1] - Station with highest annual mean.

Table 15, Thermoluminescent Dosimeters - Control

Analysis: Gamma Dose I Units: mrem

Station 1st Qtr 2023 2nd Qtr 2023 3 rd Qtr 2023 4th Qtr 2023 Annual Mean 2023

M-14 10.3 10.3 12.7 11.7 11.2 Plant: Grand Gulf Nuclear Station I Year: 2023 J Page 36 of 59 Annual Radiological Environmental Operating Report Attachment 2 Page 8 of 15 Monitoring Results Tables

Table 16, Surface Water-Gamma

Analysis: Gamma Isotopic Units: pCi/L

Location Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140

REQUIRED LLD + 15 15 30 15 30 15 30 15 15 18 60 15

MRDOWN 02/ 06 /23 <6.237 <6.853 <18.67 <7.059 <10.84 <6.962 <13.25 < 12.16 <7.684 <8.328 < 31.55 < 11.46

MRUP 02/ 06 / 23 <6.489 <7. 148 < 11.84 <7.638 <14.13 <7.335 < 12.07 < 13.7 8 <6.878 < 7.479 <35.54 < 10.64

MRDOWNGG 02/ 06 / 23 <5.895 <6.898 <14.34 <7.369 <18.63 <6.606 <11.93 <11.63 <6.013 <7.289 < 33.9 <7.018

MRUP GG 02 / 06 /23 <5.079 <7.585 < 16.66 <7.113 <15.79 <8.586 < 11.05 < 11.5 <6.462 < 5.57 9 < 31.32 < 12.84

MRDOWN 05 / 02 /23 <6.635 <6.903 < 13.29 < 9.33 <12.69 <7.348 <10.77 < 10.7 <7.399 <7.348 < 39.78 <7.188

MRUP 05 / 02/23 <6.411 <7.785 <8.004 <9.797 < 13.08 <6.215 <9.494 <1 1.12 <8.557 <6.544 < 35. 13 < 12.21

MRDOWNGG 05/ 02 / 23 <6. 198 <5.782 <7.65 <4.818 <15.49 <4.895 < 12.76 <9.35 <6.508 <6.907 <29.49 < 10.97

MRUP GG 05 / 02 /23 <5.953 <5.97 < 11.71 <7.377 <10 <7.477 <9.058 <9.916 <5.927 < 5.952 <24.56 <9.582

MRDOWN 08/ 02 / 23 <7.591 <6.36 < 14.5 <7.212 <12.22 <7.511 <12.92 < 11.42 <6.885 <6.865 <30.78 <11.27

MRUP 08/ 02/23 <5.709 <6.052 <8.042 <6.759 <10.9 <5.057 <10.65 <11.89 <6.487 <6.381 <27.68 <5.16 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 37 of 59 Annual Radiological Environmental O~eratingfteport Attachment 2 Page 9 of 15 Monitoring Results Tables

Table 16, Surface Water-Gamma

Analysis: Gamma Isotopic Units: pCi/L

Location Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140

REQUIRED LLD + 15 15 30 15 30 15 30 15 15 18 60 15

MRDOWNGG 08/ 02 /23 <7.627 <7.361 < 16. 16 <6.237 < 13.38 <6.712 <8.793 < 13. 12 <9.846 <8.248 < 32.6 7 < 13.91

MRUP GG 08/ 02 /23 <6.459 < 5.859 < 17.37 <6.713 <9.31 <5.679 < 11.29 < 10.95 <6.714 < 7.492 <30.75 <11.32

MRDOWN 10/ 31 /23 <6.644 <6.569 < 13.71 <7.609 <18.94 <7.626 <12.37 < 10.62 <8.079 <7.864 < 30.97 <7.131

MRUP 10/ 31 /23 <7.684 <8.615 <13.59 <5.587 <18.4 <9.854 <14.35 < 13.4 <8.483 <6.744 < 34.97 <9.44

MRDOWN GG 10/ 31/23 <5.578 <5.183 <12.32 <7.711 <11.68 <6.295 <9.248 < 11.1 <5.944 <5.758 <23.78 <9.49

MRUP GG 10/ 31 / 23 <7. 145 <7.666 < 14.56 <6.425 <12.67 <7.217 <9.696 <9.546 <7.242 <6.891 <30.16 < 10.5

MRDOWN* 10/ 18/23 <8.368 <7.446 < 19.36 <8.876 <17.93 <6.939 < 12.77 <10.15 <7.221 <7.786 < 36.31 < 11.31

MRDOWNGG* 10/ 18/ 23 <6.374 <7.844 < 13.72 <8.087 <16.52 <9.24 < 11.23 < 11.7 <8.029 < 7.094 <36.45 < 10.7

GG - indicates duplicate sample

Table 17, Surface Water-Tritium

Analysis: H-3 Units: pCi/L

Location I Date H-3

REQUIRED LLD + 3000

OUTFALL 007 01 / 17/23 736

OUTFALL 007 GG 01 / 17/23 651

MRDOWN 02/ 06/23 <539

MRUP 02 / 06 / 23 <539

MRDOWNGG 02 / 06 / 23 <532

MRUP GG 02 / 06 /23 <571

OUTFALL 007 02 / 14/23 <501

OUTFALL 007 GG 02 / 14/23 <496

OUTFALL 007 03 / 15/23 <586

OUTFALL 007 GG 03 / 15/23 <597

OUTFALL 007 04 / 18/23 <525

OUTFALL 007 GG 04/ 18/23 <513

OUTFALL 007 05 / 16/23 <509

OUTFALL 007 GG 05 / 16/ 23 <508

MRDOWN 05 / 02 /23 <466

MRUP 05/ 02 / 23 <475

MRDOWNGG 05 / 02 /23 <479

MRUP GG 05/ 02 / 23 <479

OUTFALL 007 06 / 13/23 <599

OUTFALL 007 GG 06/ 13/23 <613

OUTFALL 007 07 / 18/23 <541

OUTFALL 007 GG 07/ 18/ 23 <540

MRDOWN 08 / 02 /23 <573

MRUP 08/ 02 /23 <551

MRDOWNGG 08 / 02 /23 <572 Plant: Grand Gulf Nuclear Station I Rev.2023 I Page 39 of 59 Annual Radiological Environmental Operating Report Page 11 of 15 Monitoring Results Tables

Table 17, Surface Water-Tritium

Analysis: H-3 Units: pCi/L

Location Date _ H-3

MRUP GG 08/02/23 <598

OUTFALL 007 08/16/23 <482

OUTFALL 007 GG 08/16/23 <487

OUTFALL 007 09/12/23 <548

OUTFALL 007 GG 09 / 12/23 <556

OUTFALL 007 10/17/23 <571

OUTFALL 007 GG 10/17/23 <567

MRDOWN* 10/18/23 <575

MRDOWN GG* 10/18/23 <570

MRDOWN 10/31/23 <554

MRUP 10/31/23 <569

MRDOWNGG 10/31/23 <560

MRUP GG 10/31/23 <562

OUTFALL 007 11/14/23 <586

OUTFALL 007 GG 11/14/23 <586

OUTFALL 007 12/12/23 9280

OUTFALL 007 GG 12/12/23 9620

GG - indicates duplicate sample

Table 18, Drinking Water - Gamma, 1-131

Analysis: Gamma Isotopic, 1-131 Units: pCi/L

Location Date 1-131 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 Cs-134 Cs-137 Ba-140 La-140

REQUIRED LLD ~ 1 15 15 30 15 30 15 30 15 18 60 15

CONSTWELL 11 /0 8/23 <0.754 <6.757 <7.547 <11.83 <6.861 < 12.93 <8.168 < 10.02 <6.315 <5.861 <29.35 <9.228

CONSTWELL GG 11 / 08 /23 <0.794 < 7.784 <7.368 <15.33 <4.895 <1 4.9 <8.7 15 < 11.25 <7.235 <8.581 <27.99 <12.94

PGWELL 11 / 08 /2 3 <0.834 <6.979 <7. 57 <13.07 <7.958 < 18.72 <7.465 < 11.49 <6.746 <7.1 41 <40.44 <8.571

PGWELLGG 11 / 08 /23 <0.719 <5.708 <7.041 <13.79 <7.869 <14.3 <6.622 < 11.02 <7. 502 <7. 69 <26.06 <7.117

GG - indicates duplicate sample Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 41 of 59 Annual Radiological Environmental Operating Report Page 13 of 165 Monitoring Results Tables

Table 19, Drinking Water-Tritium

Analysis: H-3 Units: pCi/L

Location Date H-3

REQUIRED LLD + 2000

CONSlWELL 11 / 08 /23 <512

CONSlWELL GG 11 / 08 / 23 <521

PGWELL 11 / 08 /23 <506

PGWELLGG 11 / 08 / 23 <517

GG - indicates duplicate sample

Table 20, Sediment

Analysis: Gamma Isotopic Units: pCi/kg

Location Date Cs-134 Cs-137

REQUIRED LLD + 150 180

SEDHAM 09/06/23 <87.2 <84.37

SEDHAM GG 09/06/23 <81.08 <59.65

SEDCONT 09/06/23 <71.29 <50.13

SEDCONTGG 09/06/23 <85.66 <61.35

GG - indicates duplicate sample Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 42 of 59 Annual Radiological Environmental Operating Report Attachment 2 Page 14 of 165 Monitoring Results Tables

Table 21, Fish

Analysis: Gamma Isotopic Units: pCi/kg

Location Collection Mn-54 Co-58 Fe-59 Co-60 Zn-65 Cs-134 Cs-137 Date

REQUIRED LLD + 130 130 260 130 260 130 150

FISHDOWN 08/21/23 <33.31 <26.87 <50.69 <40.2 <61.96 <32.64 <26.61

FISHDOWNGG 08/21/23 <50.29 <37.72 <111.7 <64.72 <117.5 <57.63 <53.83

FISHUP 08/21/23 <52.18 <44.75 <107.3 <76.84 <151.8 <68.7 <49.66

FISHUP GG 08 /21/23 <56.41 <56.32 <91.64 <64.01 <107.2 <70.3 <32.87

GG - indicates duplicate sample

Table 22, Food Products

Analysis: Gamma Isotopic, 1-131 Units: pCi/kg

Location Collection Date 1-131 Cs-134 Cs-137

REQUIRED LLD + 60 60 80

VEG -CONT 02/13/23 <25.82 <26.73 <22.65

VEG-J 02/13/23 <28 <31.54 <21.95

VEG -CONTGG 02/13/23 <27.52 <27.05 <26.75

VEG -J GG 02/13/23 <28.07 <31.41 <26.22

VEG -CONT 05/15/23 <25.02 <23.44 <22.61

VEG-J 05/15/23 <28.49 <40.24 <29.82

VEG -CONTGG 05/15/23 <22.84 <20.52 <26.47

VEG -J GG 05/15/23 <40.4 <34.56 <37.66

VEG-CONT 08/14/23 <27.84 <25.87 < 16.69

VEG -J 08/14/23 <21.61 <23.56 < 18.43

VEG -CONT 11/06/23 <28.2 <29.23 <24. 18

VEG-J 11/06/23 <34.54 <26.59 <29.19

GG - indicates duplicate sample Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 43 of 59 Annual Radiological Environmer1!al Opera!ing R~ort Attachment 2 Page 155 of 165 Monitoring Results Tables

Table 23, Special Samples, Surface Water - Gamma Isotopic

Analysis: Gamma Isotopic Units: pCi/L

Location Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Nb-95 Zr-95 1-131 Cs-134 Cs-137 Ba-140 La-140

REQUIRED LLD + 15 15 30 15 30 15 30 15 15 18 60 15

OSN 007 03/20/23 <6.137 <5.242 <12.12 <5.97 <12.2 <6.706 <8.37 4 <8.272 <5.517 <5.613 <30.25 <14.39

OSN 007 GG 03/20 /23 <6.171 <6.785 <12.51 <7.82 6 <13.62 <5.89 <11.1 <10.99 <7.178 <6.42 <29.85 <10.04

OSN 007 06/21/23 <7.895 <7.171 <16. 34 <6.421 <9.47 <8.343 <12.5 <11.67 <6.711 <8.914 < 34. 39 <10.7

OSN 007 GG 06/21/23 <5.994 <4.226 <18.54 < 11.35 <16.13 <4.457 <12.09 < 11.69 <7.271 <5.844 <3 1.07 <10.92

OSN 007 09/ 25/23 <6.531 <6.914 <14.35 <7.505 <11.8 <5.269 <9.779 <7.377 <6.66 <5.931 <22.25 <8.534

OSN 007 GG 09/25/23 <4.618 <8.213 <12.35 <5.891 <16. 94 <7.57 <11.48 <7.36 <6.381 <6.074 < 18.28 <9.229

OSN 007 11/28/23 <6.007 <6.729 <12.29 <6.00 4 <14.74 <5.812 <8.033 <9.595 <7.366 <5.608 <27. 11 <8.596

OSN 007GG 11/28/23 <6.046 <6.246 <11.37 <5.109 <8.588 <5.627 <9.345 <11.49 <8.001 <5.8 <2 6.02 <7.367

GG - indicates duplicate sample

Table 24, Special Samples, Meat

Analysis: Gamma Isotopic Units: pCi/kg

Location I Date Mn-54 Co-58 Fe-59 Co-60 Zn-65 Cs-134 Cs-137

REQUIRED LLD + 130 130 260 130 260 130 150

DEER 1 10/22/23 <68.02 <75.15 <130.2 <78.96 <171.7 <73.05 <49.76 Plant: Grand Gulf Nuclear Station I Year: 2023 I Page 44 of 59 Annual Radiological Environmental Operating Report

ATTACHMENT 3

INTERLABORATORY COMPARISON RESULTS

Quality control data from the following offsite environmental laboratories are summarized in the following pages.

Teledyne Brown Engineering

Environmental Dosimetry Company/ Stanford Dosimetry.

TELEDYNE BROWN ENGINEERING The TBE Laboratory analyzed Performance Evaluation (PE) samples of air particulate (AP), air iodine, milk, soil, vegetation, and water matrices that represent test & matrix combinations available for REMP programs. 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:

A. Analytics Evaluation Criteria Analytics' evaluation report provides a ratio of TBE's 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.

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.

C. DOE Evaluation Criteria

MAPEP's 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 always resemble typical

environmental samples obtained at commercial nuclear power facilities.

For the TBE laboratory, 124 out of 131 analyses performed met the specified acceptance

criteria. Seven analyses did not meet the specified acceptance criteria and were addressed

through the TBE Corrective Action Program. A summary is found below:

1. The MAPEP February 2023 Soil Ni-63 result was evaluated as Not Acceptable. TBE's reported value was 294 Bq/kg and the known result was 1130 Bq/kg (range 791 - 1469).

The sample was reprepped by a different (senior) lab technician with results of 1120 &

1250 Bq. It was determined that there was a difference between the two techs during the sample prep (technique) and the procedure was revised to reflect these differences including using a specific aliquot amount. (NCR 23-08) 2. The MAPEP February 2023 vegetation Sr-90 result was evaluated as Not Acceptable.

The reported value was 0.05 Bq (not detected) and the known result was a "false positive".

This was considered to be a statistical failure because TBE's reported result with 3 times the uncertainty resulted in a slightly positive net result (0.03194 Bq/kg). The reported result was significantly below TBE's average detection limit for vegetation samples.

(NCR 23-09)

3. The ERA RAD April 2023 water Ba-133 result was evaluated as Not Acceptable. The reported value was 26.0 pCi/L and the known was 22.3 (acceptance range 17.1 - 25.8 pCi) or 117% of the known (acceptable for TBE QC). The sample was used as the workgroup duplicate with a result of 25.4 (114%). The sample had also been counted on a different detector with a result of 21.9 (98%). The was TBE 's first failure for Ba-133.

(NCR 23-10)

4. The MAPEP August 2023 soil Fe-55 result was evaluated as Not Acceptable. The reported value was 346 Bq/kg and the known result was 1280 (acceptance range of 896-1664 Bq/kg). This was TBE's initial evaluation for Fe-55 in soils. The result was received at the end of December and the root cause in under investigation. No client samples were associated with this cross-check. (CAR 23-31)
5. The Analytics September 2023 milk Sr-90 result was evaluated as Not Acceptable. The reported result was 7.28 pCi/L and the known result was 12.8 (57% of known). This sample was used as the workgroup duplicate and the carrier yields for both samples were 107% and 75%. The LCS recovery for the workgroup was at 106%. The ERA drinking water Sr-90 cross check that was analyzed around the same time was acceptable at 108%. There was no explanation for the failure. This is the first low biased failure for Sr-90 milk. The last failure (high) was in 2016. (NCR 23-24)
6. The ERA RAD October 2023 water Gross Alpha result was evaluated as Not Acceptable.

The reported result was 53.2 pCi/L and the known result was 70.6 (acceptable range of 54.0 - 87.2 pCi/L). The reported result was the workgroup duplicate and was within 75%

of the known value (within TBE QC range). The original result was 63.3 pCi/L (90% of the known). Because the LCS result was biased slightly high, the decision was made to report the lower value. (NCR 23-20) 7. The ERA RAD October 2023 water 1-131 result was evaluated as Not Acceptable. The reported value was 23.5 pCi/L and the known result was 29.7 (acceptable range of 25.8 -

33.6) The reported result was 79% of the known, which is within the acceptable TBE QC range. The workgroup was reviewed with no anomalies found. The LCS/LCSD results were 109% and 86.1 %. The sample was not processed in a timely manner as per the ERA instructions which stated to analyze shortly after receipt due to the short half-life.

Going forward, the QA &/or Lab Mgr. will ensure that this analysis is started sooner.

(NCR 23-21)

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

ENVIRONMENTAL DOSIMETRY COMPANY

ANNUAL QUALITY ASSURANCE STATUS REPORT

January - December 2023

Prepared By: Date:,?/('f/21,£--*

Approved By: Date: 3/;'(t1/2

Environmental Dosimetry Company 10 Ashton Lane Sterling, MA 01564 TABLE OF CONTENTS

LIST OF TABLES........................................................................................................................ ii

EXECUTIVE

SUMMARY

............................................................................................................ iii

I. INTRODUCTION............................................................................................................ 1

A. QC Program........................................................................................................ 1

B. QA Program........................................................................................................ 1

II. PERFORMANCE EVALUATION CRITERIA................................................................... 1

A. Acceptance Criteria for Internal Evaluations........................................................ 1

B. QC Investigation Criteria and Result Reporting................................................... 3

C. Reporting of Environmental Dosimetry Results to EDC Customers..................... 3

Ill. DATA

SUMMARY

FOR ISSUANCE PERIOD JANUARY-DECEMBER 2023................. 3

A. General Discussion............................................................................................. 3

B. Result Trending.................................................................................................. 4

IV. STATUS OF EDC CONDITION REPORTS (CR)........................................................... 4

V. STATUS OF AUDITS/ASSESSMENTS.......................................................................... 4

A. Internal................................................................................................................ 4

B. External.............................................................................................................. 4

VI. PROCEDURES AND MANUALS REVISED DURING JANUARY - DECEMBER 2023... 4

VII. CONCLUSION AND RECOMMENDATIONS................................................................. 4

VIII. REFERENCES............................................................................................................... 4

APPENDIX A DOSIMETRY QUALITY CONTROL TRENDING GRAPHS

LIST OF TABLES

1. Percentage of Individual Analyses Which Passed EDC Internal Criteria, January - December 2023 5
2. Mean Dosimeter Analyses (n=6), January - December 2023 5
3. Summary of Independent QC Results for 2023 5

-ii-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% 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 2023. There were no findings.

-iii-I. 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 :

A. QC Program

Dosimetry quality control tests are performed on EDC Panasonic 814 Environmental dosimeters. These tests include: (1) the in-house testing program coordinated by the EDC QA Officer and (2) independent test perform by EDC clients. In-house test are performed using six pairs of 814 dosimeters, a pair is reported as an individual result and six pairs are reported as the mean result.

Results of these tests are described in this report.

Excluded from this report are instrumentation checks. Although instrumentation checks represent an important aspect of the quality assurance program, they are not included as process checks in this report. Instrumentation checks represent between 5-10% of the TLDs processed.

B. 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.

11. PERFORMANCE EVALUATION CRITERIA

A. 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 :

where:

H; = the corresponding reported exposure for the ith

dosimeter (i.e., the reported exposure)

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

1of 6 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:

where:

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

H1 = the exposure delivered to the ith irradiated test dosimeter (i.e., the delivered exposure)

n = the number of dosimeters in the test group

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:

where:

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

R = the mean reported exposure; i.e., R = IH:( ~)

n = the number of dosimeters in the test group

3. 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.

2of 6 B. 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.

C. 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 unless if the QC results prompting the investigation have a mean bias from the known of greater than +/-20%, then 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 +/-15%.

11 1. DATA

SUMMARY

FOR ISSUANCE PERIOD JANUARY-DECEMBER 2023

A. 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 petiormance 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.

3of 6 B. 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 11,

namely: individual dosimeter accuracy, individual dosimeter precision, and mean bias.

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

IV. STATUS OF EDC CONDITION REPORTS (CR)

No condition reports were issued during this annual period.

V. STATUS OF AUDITS/ASSESSMENTS

1. Internal

EDC Internal Quality Assurance Assessment was conducted during the fourth quarter 2023. There were no findings identified.

2. External

DTE Energy Audit 23-001 was conducted on April 25-26, 2023. There were no findings identified.

V I. PROCEDURES AND MANUALS REVISED DURING JANUARY - DECEMBER 2023

No procedures or manuals were revised in 2023.

VII. 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.

VIII. REFERENCES

1. EDC Quality Control and Audit Assessment Schedule, 2023.
2. EDC Manual 1, Quality System Manual, Rev. 4, September 28, 2020.

4of 6 TABLE 1

PERCENTAGE OF INDIVIDUAL DOSIMETERS THAT PASSED EDC INTERNAL CRITERIA JANUARY - DECEMBER 2023( 11 * (2l

1 Numbe rr % P-assed Bias erlteiia % Passed IPreelslon Dosimeter, Type iTested 0rlteliia

\\ 100 Panasonic Environmental 72 100

<1lThis table summarizes results of tests conducted by EDC.

<2lEnvironmental dosimeter results are free in air.

TABLE 2

MEAN DOSIMETER ANALYSES lN=6)

JANUARY - DECEMBER 2023d), (2l

- Standard,

Process Date Exposure bevel Mean Bias% Tiolerance 1 JE>e'liatlon % ~L imit at-/-15%

4/25/2023 107 0.8 1.1 Pass 5/2/2023 33 5.4 1.6 Pass 5/15/2023 56 5.1 1.3 Pass 7/23/2023 52 0.0 0.7 Pass 7/26/2023 33 2.8 2.6 Pass 8/14/2023 76 -3.0 1.5 Pass 11/4/2023 44 1.7 0.8 Pass 11/13/2023 64 -1.9 2.4 Pass 12/08/2023 83 2.7 1.0 Pass 01/30/2024 28 -0.7 1.6 Pass 02/04/2024 123 -2.7 1.6 Pass 02/8/2024 97 -1.1 1.2 Pass

<1lThis table summar izes results of tests conducted by EDC for TLDs issued in 2023.

<2 >Environmental dosimeter results are free in air.

TABLE 3

SUMMARY

OF INDEPENDENT DOSIMETER TESTING JANUARY - DECEMBER 2023( 11 * (2l

lssuanee Peilod SIient Mean Standard latlon % Pass 1 fall Blas% Dev,

1s t Qtr. 2023 Millstone 1.9 1.1 Pass 2 na Qtr.2023 Seabrook 0.6 1.3 Pass 3ra Qtr. 2023 Millstone -3.8 1.4 Pass 3ra Qtr. 2023 SONGS -14.8 1.5 Pass 4tn Qtr.2023 Millstone 7.7 5.3 Pass 41n Qtr.2023 PSEG(PNNL) 48mR 2.9 2.9 Pass 4m Qtr.2023 PSEG(PNNL) 95mR 0.0 0.7 Pass 41n Qtr.2023 PSEG(PNNL) 143mR 1.2 1.3 Pass 4m Qtr.2023 PSEG(PNNL) 191 R 2.2 0.6 Pass 4 111 Qtr.2023 Seabrook 2.6 1.6 Pass

<1lperformance criteria are +/- 15%.

<2 >sIind spike irradiations using Cs-137

5of 6 APPENDIX A

DOSIMETRY QUALITY CONTROL TRENDING GRAPHS

ISSUE PERIOD JANAURY - DECEMBER 2023

6of 6 INDMDUAL ACCURACY ENVIRONMENTAL FIGURE 1

1fi

14

12

1D

B

6 I

  • I
  • 4 I
  • I 2 * *
  • I I
  • D--l-J!!"""-'*:..,a,..__ ___ ______ *_ *_,;. _____________ ___ ~ __ __........ ________ --J I

-2 * * * ** I *...

-4 * * * *

-8

-10

-12

-14

PROCESSING DATE INDMDUAI.. PRECISION ENVIRONMENTAL FIGURE2

16

14

12

10

B

6

4 z 2..

0....

en D.............

c3 -2 w...

a:

a.. -4

-<5

-l!

-10

-12 LSL--12.&

-14

PROCESSING DATE MEAN ACCURACY ENVIRONMENTAL FIGURE3 16 ------------ -------------------------

14

12

6 -

4 -

-2

-II -

  • 10-

.14 _

LR. - -u

-16~ --....-----,------,--------.----- --..-----,------,--------.-------..-----,-----,-----.---~

PROCESSING DATE SEABROOK CD-LOCATE ACCURACY FIGURE4

20 ~----- ----------- - ------- - ------------------------------

18

16

11 12

1D

8

6 1

2

  • D - a * *

~ -2 * * * * * *

  • CD -'4
  1. - -i5 * *

-8

  • 10
  • 12

-11

-16

-18

  • 20 -~ --------------------------------------------------

EXPECTED FIELD EXPOSURE (mRISTD. QUARTER

Retrieved from "https://kanterella.com/w/index.php?title=ML24107A887&oldid=3685868"