Text

2022 Radiological Environmental Operating Report
	ML23137A151
Person / Time
Site:	Vermont Yankee
Issue date:	05/10/2023
From:	Daniels C; NorthStar Nuclear Decommissioning Company
To:	; Office of Nuclear Reactor Regulation, Document Control Desk
References
	BVY 23-013
	Download: ML23137A151 (1)
	v • d • e

Northstar Nuclear Decommissioning Co., LLC

~ Vermont Yankee Nuclear Power Station North Star 320 Governor Hunt Rd.

,rnon, VT 05354 802-451-5354 Corey R. Daniels ISFSI Senior Manager 10 CFR 50, Appx I, SEC IV.B.2 and IV.B.3 BVY 23-013 May 10, 2023 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

2022 Radiological Environmental Operating Report Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28

Dear Sir or Madam:

In accordance with 10 CFR 50, Appendix I, Sections IV.B.2 and IV.B.3 and the Vermont Yankee Off-site Dose Calculation Manual, please find enclosed a copy of the 2022 Annual Radiological Environmental Operating Report.

This letter contains no new regulatory commitments.

Should you have any questions concerning this letter, or require additional information, please contact Mr. Thomas B. Silko at (802) 451-5354, Ext 2506.

Sincerely,

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CRD/tbs

Enclosure:

Annual Radiological Environmental Operating Report for 2022.

BVY 23-013 / Page 2 of 2 cc: Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road, Suite 102 King of Prussia, PA 19406-1415 Commissioner Vermont Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05602-2601 Massachusetts Department of Public Health Director, Radiation Control Program 529 Main Street, Suite 1 M2A Charlestown, MA 02129 Commissioner Massachusetts Department of Conservation and Recreation 251 Causeway Street Boston, MA 02114

BVY 23-013 Docket No. 50-271 Enclosure Vermont Yankee Nuclear Power Station Annual Radiological Environmental Operating Report for 2022 (78 pages excluding this cover sheet)

BVY 23-013 / Enclosure / Page 1 of 78 NORTHSTAR-VERMONTYANKEE Vermont Yankee Nuclear Power Station ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT Year 2022 Reviewed by: - - - - - - - - , , - - - - - - - - - - - - - - '/ (//f",11 J * //'/!_

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BVY 23-013 / Enclosure / Page 2 of 78 TABLE OF CONTENTS

1. INTRODUCTION ............................................................................................................... 4

2. BACKGROUND RADIOACTIVITY ................................................................................. 5 2.1 Naturally Occurring Background Radioactivity .............................................................. 5 2.2 Man-Made Background Radioactivity ............................................................................. 6

3. GENERAL PLANT AND SITE INFORMATION ............................................................. 6

4. PROGRAM DESIGN .......................................................................................................... 7 4.1 Monitoring Zones ............................................................................................................. 7 4.2 Pathways Monitored......................................................................................................... 8 4.3 Descriptions of Monitoring Programs .............................................................................. 8 4.3.1 Air Sampling ............................................................................................................................. 8 4.3.2 Charcoal Cartridge (Radioiodine) Sampling ............................................................................. 9 4.3.3 River Water Sampling ............................................................................................................... 9 4.3.4 Ground Water (Deep Well Potable Water) Sampling ............................................................... 9 4.3.5 Sediment Sampling ................................................................................................................... 9 4.3.6 Milk Sampling......................................................................................................................... 10 4.3.7 Silage (Chopped Corn or Grass) Sampling ............................................................................. 10 4.3.8 Mixed Grass Sampling ............................................................................................................ 10 4.3.9 Fish Sampling ......................................................................................................................... 10 4.3.10 TLD Monitoring.................................................................................................................. 10

5. RADIOLOGICAL DATA

SUMMARY

TABLES ........................................................... 23

6. ANALYSIS OF ENVIRONMENTAL RESULTS ............................................................ 37 6.1 Sampling Program Deviations ....................................................................................... 37 6.2 Comparison of Achieved LLDs with Requirements ...................................................... 38 6.3 Comparison of Results with Reporting Levels .............................................................. 39 6.4 Changes in Sampling Locations ..................................................................................... 39 6.5 Data Analysis by Media Type ........................................................................................ 40

7. QUALITY ASSURANCE PROGRAM ............................................................................ 59 7.1 Environmental Dosimetry Company Laboratory ........................................................... 59 7.2 Teledyne Brown Engineering Laboratory - Environmental Services (TBE-ES) .......... 72 7.2.1 Operational Quality Control Scope ......................................................................................... 72 7.2.2 Analytical Services Quality Control Synopsis ........................................................................ 73

8. LAND USE CENSUS........................................................................................................ 75

9.

SUMMARY

....................................................................................................................... 77

10. REFERENCES .................................................................................................................. 78 VY 2022 AREOR Page 2 of 78

BVY 23-013 / Enclosure / Page 3 of 78 LIST OF TABLES Table 4.1 Radiological Environmental Monitoring Program ....................................................... 11 Table 4.2 Radiological Environmental Monitoring Locations (Non-TLD) In 2022 .................... 13 Table 4.3 Radiological Environmental Monitoring Locations (TLD) In 2022 ............................ 14 Table 4.4 Environmental Lower Limit Of Detection (LLD) Sensitivity Requirements ............... 15 Table 4.5 Reporting Levels for Radioactivity Concentrations in Environmental Samples .......... 16 Table 5.1 Sample Medium Analyses ............................................................................................ 25 Table 5.2 Environmental TLD Data Summary ............................................................................. 35 Table 5.3 Environmental TLD Measurements 2022..................................................................... 36 Table 6.1 Removed........................................................................................................................ 45 Table 6.2 Trend Graph Summary Table ....................................................................................... 46 Table 8.1 2022 Land Use Census Locations* ............................................................................... 76 LIST OF FIGURES Figure 4.1 Environmental Sampling Locations in Close Proximity to the Plant .......................... 17 Figure 4.2 Environmental Sampling Locations Within 5 km of the Plant.................................... 18 Figure 4.3 Environmental Sampling Locations Greater Than 5 km from the Plant ..................... 19 Figure 4.4 TLD Locations in Close Proximity to the Plant .......................................................... 20 Figure 4.5 TLD Locations within 5 km of the Plant ..................................................................... 21 Figure 4.6 TLD Locations Greater Than 5 km of the Plant .......................................................... 22 Figure 6.1 Gross Beta Measurements on Air Particulate Filters Quarterly Average Concentrations .............................................................................................................................. 47 Figure 6.2 Gross Beta Measurements on Air Particulate Filters (11) ........................................... 48 Figure 6.3 Gross Beta Measurements on Air Particulate Filters (12) ........................................... 49 Figure 6.8 Gross Beta Measurements on River Water Semi-Annual Concentrations .................. 50 Figure 6.9 Gross Beta Measurements on Ground Water Semi-Annual Concentrations ............... 51 Figure 6.12 Cesium 137 in Fish - Annual Average Concentrations ............................................. 52 Figure 6.13 Average Exposure Rate at Inner Ring, Outer Ring and Control TLDs ..................... 53 Figure 6.14 Exposure Rate at Indicator TLDs DR-1, DR-2 and DR-3 ......................................... 54 Figure 6.15 Exposure Rate at Indicator TLDs DR-6 and DR-50.................................................. 55 Figure 6.16 Exposure Rate at Site Boundary TLDs DR-7, DR-8 and DR-53A ........................... 56 Figure 6.17 Exposure Rate at Site Boundary TLDs DR-43, DR-44, DR-45 and DR-46 ............. 57 Figure 6.27 Exposure Rate at Control TLDs DR-4 and DR-5 ...................................................... 58 VY 2022 AREOR Page 3 of 78

BVY 23-013 / Enclosure / Page 4 of 78

1. INTRODUCTION This report summarizes the findings of the Radiological Environmental Monitoring Program (REMP) conducted by Northstar-Vermont Yankee in the vicinity of the Vermont Yankee Nuclear Power Station (VY) in Vernon, Vermont during the calendar year 2022. The analyses of samples collected indicated that no plant-generated radioactive material was found in any location off site. In all cases, the possible radiological impact was negligible with respect to exposure from natural background radiation. In no case did the detected levels exceed the most restrictive federal regulatory or plant license limits for radionuclides in the environment.

Measured values were several orders of magnitude below reportable levels listed in Table 4.5 of this report. Except for sample deviations listed in Section 6.1, all other samples were collected and analyzed as required by the program.

This report is submitted annually in compliance with the Vermont Yankee Offsite Dose Calculation Manual (VY ODCM), Section 10.2. The remainder of this report is organized as follows:

Section 2: Provides an introductory explanation of background radioactivity and radiation detected in the plant environs.

Section 3: Provides a brief description of the Vermont Yankee Nuclear Power Station site and its environs.

Section 4: Provides a description of the overall REMP program design. Included is a summary of the Vermont Yankee Nuclear Power Station (VY) Off-Site Dose Calculation Manual (ODCM) requirements for REMP sampling, tables listing all locations sampled or monitored in 2022 with compass sectors and distances from the plant, and maps showing each REMP location. Tables listing Lower Limit of Detection requirements and Reporting Levels are also included.

Section 5: Consists of the summarized data as required by the VY ODCM. The tables are in a format similar to that specified by the NRC Radiological Assessment Branch Technical Position on Environmental Monitoring (Reference 1). Also included is a summary of the 2022 environmental TLD measurements.

Section 6: Provides the results of the 2022 monitoring program. The performance of the program in meeting regulatory requirements as given in the ODCM is discussed, and the data acquired during the year are analyzed.

Section 7: Provides an overview of the Quality Assurance programs used at Environmental Dosimetry Company and Teledyne Brown Engineering for contracted analyses of environmental media.

Section 8: Summarizes the requirements and the results of the 2022 Land Use Census.

Section 9: Gives a summary of the 2022 Radiological Environmental Monitoring Program.

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BVY 23-013 / Enclosure / Page 5 of 78

2. BACKGROUND RADIOACTIVITY Radiation or radioactivity potentially detected in the Vermont Yankee environment can be grouped into three categories. The first is naturally-occurring radiation and radioactivity. The second is man-made radioactivity from sources other than the Vermont Yankee plant. The third potential source of radioactivity is due to emissions from the Vermont Yankee plant. For the purposes of the Vermont Yankee REMP, the first two categories are classified as background radiation and are the subject of discussion in this section of the report. The third category is the one that the REMP is designed to detect and evaluate.

2.1 Naturally Occurring Background Radioactivity Natural radiation and radioactivity in the environment, which provide the major source of human radiation exposure, may be subdivided into three separate categories: primordial radioactivity, cosmogenic radioactivity and cosmic radiation. Primordial radioactivity is made up of those radionuclides that were created with the universe and that have a sufficiently long half-life to be still present on the earth. Included in this category are the newly-formed daughter radionuclides descending from these original elements. A few of the more significant radionuclides in this category are Uranium-238 (U-238), Thorium-232 (Th-232), Rubidium-87 (Rb-87), Potassium-40 (K-40), Radium-226 (Ra-226), and Radon-222 (Rn-222). Uranium-238 and Thorium-232 are readily detected in soil and rock, whether through direct field measurements or through laboratory analysis of samples. Radium-226 in the earth can find its way from the soil into ground water and is often detectable there. Radon-222 is one of the components of natural background in air, and its daughter products are detectable on air sampling filters. Potassium-40 comprises about 0.01 percent of all natural potassium in the earth, and is consequently detectable in most biological substances, including the human body. There are many more primordial radionuclides found in the environment in addition to the major ones discussed above (Reference 2).

The second sub-category of naturally-occurring radiation and radioactivity is cosmogenic radioactivity. This is produced through the nuclear interaction of high energy cosmic radiation with elements in the earths atmosphere, and to a much lesser degree, in the earths crust. These radioactive elements are then incorporated into the entire geosphere and atmosphere, including the earths soil, surface rock, biosphere, sediments, ocean floors, polar ice and atmosphere. The major radionuclides in this category are Carbon-14 (C-14), Hydrogen-3 (H-3 or Tritium), Sodium-22 (Na-22), and Beryllium-7 (Be-7). Beryllium-7 is the one most readily detected, and is found on air sampling filters and occasionally in biological media (Reference 2).

The third sub-category of naturally-occurring radiation and radioactivity is cosmic radiation.

This consists of high energy atomic and sub-atomic particles of extra-terrestrial origin and the secondary particles and radiation that are produced through their interaction in the earths atmosphere. The majority of this radiation comes from outside of our solar system, and to a lesser degree from the sun. We are protected from most of this radiation by the earths atmosphere, which absorbs the radiation. Consequently, one can see that with increasing elevation one would be exposed to more cosmic radiation as a direct result of a thinner layer of air for protection. This direct radiation is detected in the field with gamma spectroscopy equipment, high pressure ion chambers and thermoluminescent dosimeters (TLDs).

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BVY 23-013 / Enclosure / Page 6 of 78 2.2 Man-Made Background Radioactivity The second source of background radioactivity in the Vermont Yankee environment is from man-made sources not related to the power plant. The most recent contributor (prior to year 2011) to this category was the fallout from the Chernobyl accident in April of 1986, which was detected in the Vermont Yankee environment and other parts of the world. Some smaller amounts of radioactivity were detected in the environment following the Fukushima Daiichi plants accidents in March 2011. A much greater contributor to this category, however, has been fallout from atmospheric nuclear weapons tests. Tests were conducted from 1945 through 1980 by the United States, the Soviet Union, the United Kingdom, China and France, with the large majority of testing occurring during the periods 1954-1958 and 1961-1962. (A test ban treaty was signed in 1963 by the United States, Soviet Union and United Kingdom, but not by France and China.)

Atmospheric testing was conducted by the Peoples Republic of China as recently as October 1980.

Much of the fallout detected today is due to this explosion and the last large scale test performed in November of 1976 (Reference 3).

The radioactivity produced by these detonations was deposited worldwide. The amount of fallout deposited in any given area is dependent on many factors, such as the explosive yield of the device, the latitude and altitude of the detonation, the season in which it occurred, and the timing of subsequent rainfall which washes fallout from the troposphere (Reference 4). Most of this fallout has decayed into stable elements, but the residual radioactivity is still readily detectable in environmental samples worldwide. The two predominant radionuclides are Cesium-137 (Cs-137) and Strontium-90 (Sr-90). They are found in soil and in vegetation, and since cows and goats graze large areas of vegetation, these radionuclides are also concentrated and often detected in milk.

Other potential man-made sources of environmental background radioactivity include other nuclear power plants, coal-fired power plants, national defense installations, hospitals, research laboratories and industry. These, collectively, are insignificant on a global scale when compared to the sources discussed above (natural and weapons-testing fallout).

3. GENERAL PLANT AND SITE INFORMATION The Vermont Yankee Nuclear Power Station is located in the town of Vernon, Vermont in Windham County. The 130-acre site is on the west shore of the Connecticut River, immediately upstream of the Vernon Hydroelectric Station. The plant site is bounded on the north, south and west by privately-owned land and on the east by the Connecticut River. The surrounding area is generally rural and lightly populated, and the topography is flat or gently rolling on the valley floor.

Construction of the single unit 540 megawatt BWR (Boiling Water Reactor) plant began in 1967.

The pre-operational Radiological Environmental Monitoring Program, designed to measure environmental radiation and radioactivity levels in the area prior to station operation, began in 1970. Commercial operation began on November 30, 1972. An Extended Power Uprate, conducted in 2006, resulted in the generation capacity increasing to 650 megawatts electric.

Vermont YankeeNuclear Power Station permanently shutdown on December 29, 2014.

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BVY 23-013 / Enclosure / Page 7 of 78

4. PROGRAM DESIGN The Radiological Environmental Monitoring Program (REMP) for the Vermont Yankee Nuclear Power Station (VY) was designed with specific objectives in mind. These are:

To provide an early indication of the appearance or accumulation of any radioactive material in the environment caused by the operation of the station.

To provide assurance to regulatory agencies and the public that the stations environmental impact is known and within anticipated limits.

To verify the adequacy and proper functioning of station effluent controls and monitoring systems.

To provide standby monitoring capability for rapid assessment of risk to the general public in the event of unanticipated or accidental releases of radioactive material. The program was initiated in 1970, approximately two years before the plant began commercial operation. It has been functioning continuously since that time, with improvements made periodically over those years.

The current program is designed to meet the intent of NRC Regulatory Guide 4.1, Programs for Monitoring Radioactivity in the Environs of Nuclear Power Plants; NRC Regulatory Guide 4.8, Environmental Technical Specifications for Nuclear Power Plants; the NRC Radiological Assessment Branch Technical Position of November 1979, An Acceptable Radiological Environmental Monitoring Program; and NRC NUREG-0473, Radiological Effluent Technical Specifications for BWRs. The environmental TLD program has been designed and tested around NRC Regulatory Guide 4.13, Performance, Testing and Procedural Specifications for Thermoluminescence Dosimetry: Environmental Applications. The quality assurance program is designed around the guidance given in NRC Regulatory Guide 4.15, Quality Assurance for Radiological Monitoring Programs (Normal Operations) - Effluent Streams and the Environment.

The sampling requirements of the REMP are given in the Off-Site Dose Calculation Manual Table 3.5.1 and are summarized in Table 4.1 of this report. The identification of the required sampling locations is given in the Off-Site Dose Calculation Manual (ODCM), Chapter 7. These sampling and monitoring locations are shown graphically on the maps in Figures 4.1 through 4.6 of this report.

The Vermont Yankee Radiation Protection/Chemistry Department conducts the radiological environmental monitoring program and facilitates the collection of all airborne, terrestrial and ground water samples. VY maintains a contract with Normandeau Associates to collect all fish and river sediment samples. In 2022, analytical measurements of environmental samples were performed at Teledyne Brown Engineering Laboratory in Knoxville, Tennessee. TLD badges are posted and retrieved by the Vermont Yankee Chemistry Department and were analyzed by the Environmental Dosimetry Company in Sterling, Massachusetts.

4.1 Monitoring Zones The REMP is designed to allow comparison of levels of radioactivity in samples from the area possibly influenced by the plant to levels found in areas not influenced by the plant. Monitoring locations within the first zone are called indicators. Those within the second zone are called VY 2022 AREOR Page 7 of 78

BVY 23-013 / Enclosure / Page 8 of 78 controls. The distinction between the two zones, depending on the type of sample or sample pathway, is based on one or more of several factors, such as site meteorological history, meteorological dispersion calculations, relative direction from the plant, river flow, and distance.

Analysis of survey data from the two zones aids in determining if there is a significant difference between the two areas. It can also help in differentiating between radioactivity and radiation due to plant releases and that due to other fluctuations in the environment, such as atmospheric nuclear weapons test fallout or seasonal variations in the natural background.

4.2 Pathways Monitored Four pathway categories are monitored by the REMP. They are the airborne, waterborne, ingestion and direct radiation pathways. Each of these four categories is monitored by the collection of one or more sample media, which are listed below, and are described in more detail in this section:

Airborne Pathway Air Particulate Sampling Waterborne Pathways River Water Sampling Ground Water Sampling Sediment Sampling Ingestion Pathways Silage Sampling Mixed Grass Sampling Fish Sampling Direct Radiation Pathway TLD Monitoring 4.3 Descriptions of Monitoring Programs 4.3.1 Air Sampling Continuous air samplers were installed at seven locations until August 4, 2015, when sample collection was discontinued at one station not required by the VY ODCM. Another station was removed from service in March 2016 (ODCM Rev 36) because it was a non-required control sample and with the plant in permanent shut down, it was deleted from the REMP. In December 2016, two more air sample stations were removed from service with the release of ODCM Rev 37.

At the beginning of 2021, three air sample stations were situated to support the program.Currently there are two indicator stations and one control station. Data from all samples collected in 2022 are included in this report. The sampling pumps at these locations operate continuously at a flow rate of approximately one cubic foot per minute. Airborne particulates are collected by passing air through a 50 mm glass-fiber filter. A dry gas meter is incorporated into the sampling VY 2022 AREOR Page 8 of 78

BVY 23-013 / Enclosure / Page 9 of 78 stream to measure the total volume of air sampled in a given interval. The entire system is housed in a weatherproof structure. The filters were collected on a weekly frequency through the end of October 2018. Due to changes in the VY ODCM, the weekly collections were revised to monthly during November and December 2018. To allow for the decay of radon daughter products, the analysis for gross beta radioactivity is delayed for more than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The monthly filters are composited by location at the environmental laboratory for a quarterly gamma spectroscopy analysis.

If the gross-beta activity on an air particulate sample is greater than ten times the yearly mean of the control samples, ODCM Table 3.5.1, Note c, then a gamma isotopic analysis of the sample is required.

4.3.2 Charcoal Cartridge (Radioiodine) Sampling Continuous air samplers were installed at seven locations until August 4, 2015 when sample collection was discontinued at one station not required by the VY ODCM. One station was removed in March 2016 (ODCM Rev 36) because it was a non-required control sample and with the plant in permanent shut down, it was removed from the REMP. In December 2016 all charcoal filters were removed from sample stations with the implementation of ODCM Rev 37. With the radioactive decay and ultimate cessation of I-131 in the plant effluent stream, there is no longer a credible source of radioiodine generated by VY.

4.3.3 River Water Sampling A grab sample is collected monthlyat the upstream control location. Each sample is analyzed for gamma-emitting radionuclides. Although not required by the VY ODCM, a gross-beta analysis is also performed on each sample. The monthly samples are composited by location by the contracted environmental laboratory for a minimum frequency of quarterly tritium (H-3) analysis.

The Service Water System was removed from service in December of 2018. There has not been a continuous discharge of water to the river since that time. Revision 41 of the VY ODCM (July 2021) eliminated the requirement for the automatic composite sampler at the downstream location and replaced it with a monthly grab sample.

4.3.4 Ground Water (Deep Well Potable Water) Sampling Grab samples are collected quarterly from two indicator locations and one control location. Only one indicator and one control are required by the VY ODCM. Each sample is analyzed for gamma-emitting radionuclides and H-3. Although not required by the VY ODCM, a gross-beta analysis is also performed on each sample.

4.3.5 Sediment Sampling River sediment grab samples were collected semiannually from the downriver location and at the North Storm Drain Outfall by Normandeau Associates. Each sample is analyzed at an offsite environmental laboratory for gamma-emitting radionuclides.

VY 2022 AREOR Page 9 of 78

BVY 23-013 / Enclosure / Page 10 of 78 4.3.6 Milk Sampling Milk sample collection was terminated in December 2016 based upon assessment of potential releases of radioiodine from the plant and a concurrent revision of the Vermont Yankee Offsite Dose Calculation Manual. Radioactive decay has removed I-131 from plant radioactive materials inventory.

4.3.7 Silage (Chopped Corn or Grass) Sampling Silage samples are collected on a quarterly basis from two Land Use Census-identified indicator farms and one control farm. The silage from each location is shipped to the contracted environmental laboratory where each sample is analyzed for gamma-emitting radionuclides.

4.3.8 Mixed Grass Sampling At each air sampling station, a mixed grass sample is collected quarterly, when available. Enough grass is clipped to provide the minimal sample weight needed to achieve the required Lower Limit of Detection (LLD). The mixed grass samples are analyzed for gamma-emitting radionuclides.

Until iodine sampling was discontinued by ODCM Rev 37 in December 2016, the grass samples were analyzed for low-level I-131. This analysis was not required by the ODCM but had been performed for a number of years.

4.3.9 Fish Sampling Fish samples were collected semiannually at two Connecticut River locations (upstream of the plant and in the Vernon Pond) by Normandeau Associates during 2022. The samples are frozen and delivered to the environmental laboratory where the edible and inedible portions are separately analyzed for gamma-emitting radionuclides.

4.3.10 TLD Monitoring Direct gamma radiation exposure is continuously monitored with the use of thermoluminescent dosimeters (TLDs). Specifically, Panasonic UD-801AS1 and UD-814AS1 calcium sulfate dosimeters are used, with a total of five elements in place at each monitoring location. Each pair of dosimeters is sealed in a plastic bag, which is in turn housed in a plastic screen cylinder. This cylinder is attached to an object such as a fence or utility pole.

A total of 10 stations were required by the ODCM in 2022 and must be read out quarterly unless gaseous release controls were exceeded during the period. Vermont Yankee Radiation Protection/Chemistry Department staff posts and retrieves all TLDs, while the contracted environmental laboratory (Environmental Dosimetry Company) provides processing.

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BVY 23-013 / Enclosure / Page 11 of 78 Table 4.1 Radiological Environmental Monitoring Program (as required by ODCM Table 3.5.1)*

Collection Analysis Exposure Pathway Number Routine and/or Sample Media of Collection Analysis Analysis Sample Sampling Frequency Mode Type Frequency Locations

1. Direct Radiation 10 Continuous Quarterly Gamma dose; de- Each TLD (TLDs) dose only, unless gaseous release Control was exceeded

2. Airborne 3 Continuous Monthly Particulate Each Sample (Particulates) Sample:

Gross Beta Quarterly Gamma Isotopic Composite (by location)

3. Waterborne

a. Surface water 2 Downstream. Monthly Gamma Isotopic Each Sample grab Upstream:

grab Tritium (H-3) Quarterly Composite

b. Ground water 3 Grab Quarterly Gamma Isotopic Each Sample Tritium (H-3) Each Sample

c. Shoreline 2 Downstream: Semiannually Gamma Isotopic Each Sample Sediment grab N. Storm Drain Outfall:

grab

See ODCM Table 3.5.1 for complete footnotes.

VY 2022 AREOR Page 11 of 78

BVY 23-013 / Enclosure / Page 12 of 78 Table 4.1 cont.

Radiological Environmental Monitoring Program (as required by ODCM Table 3.5.1)*

Collection Analysis Exposure Pathway and/or Sample Number of Routine Collection Number of Routine Media Sample Sampling Frequency Sample Sampling Locations Mode Locations Mode

4. Ingestion

a. Fish 2 Grab Semiannually Gamma Isotopic Each Sample on Edible Portions

b. Vegetation Grass Sample 1 at each air Grab Quarterly Gamma Isotopic Each Sample sampling when available station Silage Sample 2 Indicator Grab Quarterly Gamma Isotopic Each Sample 1 Control

See ODCM Table 3.5.1 for complete footnotes.

VY 2022 AREOR Page 12 of 78

BVY 23-013 / Enclosure / Page 13 of 78 Table 4.2 Radiological Environmental Monitoring Locations (Non-TLD) In 2022 Distance Direction Exposure from Plant from Pathway Station Code Station Description Zone (a) Stack (km) Plant

1. Airborne AP/CF-11 River Sta. No. 3.3 I 1.9 SSE AP/CF-12 N. Hinsdale, NH I 3.6 NNW AP/CF-21 Spofford Lake C 16.4 NNE

2. Waterborne

a. Surface WR-11 River Sta. No. 3.3 I 1.9 SSE WR-21 Rt.9 Bridge C 11.8 NNW

b. Ground WG-11 Main Plant Well I 0.2 On-site WG-12 Vernon Green Well I 2.1 SSE WT-14 Test Well 201 I -- On-site WT-16 Test Well 202 I -- On-site WT-17 Test Well 203 I -- On-site WT-18 Test Well 204 I -- On-site WG-22 Copeland Well C 13.7 N

c. Sediment SE-11 Shoreline Downriver I 0.6 SSE SE-12 North Storm Drain Outfall I 0.1 E

3. Ingestion

a. Fish FH-11 Vernon Pond I 0.6 (b) SSE FH-21 Rt.9 Bridge C 11.8 NNW

b. Mixed Grass TG-11 River Sta. No. 3.3 I 1.9 SSE TG-12 N. Hinsdale, NH I 3.6 NNW TG-21 Spofford Lake C 16.4 NNE

c. Silage TC-11 Miller Farm I 0.8 W TC-18 Blodgett Farm I 3.6 SE TC-22 Franklin Farm C 9.7 WSW (a) I = Indicator Stations; C = Control Stations (b) Fish samples are collected anywhere in Vernon Pond (Connecticut River, Vernon Hydro Station impoundment), which is adjacent to the plant (see Figure 4.1).

VY 2022 AREOR Page 13 of 78

BVY 23-013 / Enclosure / Page 14 of 78 Table 4.3 Radiological Environmental Monitoring Locations (TLD) In 2022 Distance Direction from Plant from Station Code Station Description Zone(a) (km) (b) Plant (b)

DR-l River Sta. No. 3.3 AI 1.6 SSE DR-2 N. Hinsdale, NH AI 3.9 NNW DR-5 Spofford Lake C 16.5 NNE DR-6 Vernon School AI 0.52 WSW DR-7 Site Boundary SB 0.28 W DR-8 Site Boundary IR 0.25 SSW DR-43 Site Boundary IR 0.44 SSE DR-45 Site Boundary IR 0.12 NE DR-46 Site Boundary IR 0.28 NNW DR-53A West Cornfield SB 0.34 WSW (a) IR = Incident Response TLD; AI = Area of Interest TLD; C = Control TLD; SB = Site Boundary TLD.

(b) Distance and direction is relative to the center of the Turbine Building [DS1]for direct radiation monitors.

VY 2022 AREOR Page 14 of 78

BVY 23-013 / Enclosure / Page 15 of 78 Table 4.4 Environmental Lower Limit Of Detection (LLD) Sensitivity Requirements Airborne Particulates Water or Gases Fish Vegetation Sediment Analysis (pCi/l) (pCi/m3) (pCi/kg) (pCi/kg) (pCi/kg dry)

Gross-Beta 4 0.01 H-3 2,000(a)

Mn-54 15 130 Co-60 15 130 Zn-65 30 260 Zr- 95 15 Cs-134 15 0.05 130 60 150 Cs-137 18 0.06 150 60 180 (a) If no drinking water pathway exists, a value of 3,000 picocuries/liter may be used.

See ODCM Table 4.5.1 for additional explanatory footnotes.

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BVY 23-013 / Enclosure / Page 16 of 78 Table 4.5 Reporting Levels for Radioactivity Concentrations in Environmental Samples Airborne Particulates Food Water or Gases Fish Product Sediment Analysis (pCi/l) (pCi/m3) (pCi/kg) (pCi/kg) (pCi/kg dry)

H-3 20,000(a)

Mn-54 1,000 30,000 Co-60 300 10,000 3,000(b)

Zn-65 300 20,000 Zr- 95 400 Cs-134 30 10 1,000 1,000 Cs-137 50 20 2,000 2,000 (a) Reporting Level for drinking water pathways. For non-drinking water, a value of 30,000pCi/liter may be used.

(b) Reporting level for individual grab samples taken at North Storm Drain Outfall only.

See ODCM Table 3.5.2 for additional explanatory footnotes.

VY 2022 AREOR Page 16 of 78

BVY 23-013 / Enclosure / Page 17 of 78 Figure 4.1 Environmental Sampling Locations in Close Proximity to the Plant VY 2022 AREOR Page 17 of 78

BVY 23-013 / Enclosure / Page 18 of 78 Figure 4.2 Environmental Sampling Locations Within 5 km of the Plant VY 2022 AREOR Page 18 of 78

BVY 23-013 / Enclosure / Page 19 of 78 Figure 4.3 Environmental Sampling Locations Greater Than 5 km from the Plant VY 2022 AREOR Page 19 of 78

BVY 23-013 / Enclosure / Page 20 of 78 Figure 4.4 TLD Locations in Close Proximity to the Plant VY 2022 AREOR Page 20 of 78

BVY 23-013 / Enclosure / Page 21 of 78 Figure 4.5 TLD Locations within 5 km of the Plant VY 2022 AREOR Page 21 of 78

BVY 23-013 / Enclosure / Page 22 of 78 Figure 4.6 TLD Locations Greater Than 5 km of the Plant VY 2022 AREOR Page 22 of 78

BVY 23-013 / Enclosure / Page 23 of 78

5. RADIOLOGICAL DATA

SUMMARY

TABLES This section summarizes the analytical results of the environmental samples that were collected during 2022. These results, shown in Table 5.1, are presented in a format similar to that prescribed in the NRCs Radiological Assessment Branch Technical Position on Environmental Monitoring (Reference 1). The results are ordered by sample media type and then by radionuclide. The units for each media type are also given.

In 2022, Vermont Yankee contracted with one laboratory for primary analyses of the environmental samples. A second laboratory was available, if needed, to cross-check the first laboratory for selected samples and to analyze other samples for hard-to-detect radionuclides (such as Strontium-89 and 90).

The left-most columns of Table 5.1 contains the medium or pathway sampled, the radionuclide of interest, the total number of analyses for that radionuclide in 2022 and the number of measurements which exceeded the Reporting Levels found in Table 3.5.2 of the VY Off-site Dose Calculation Manual. The latter are classified as Non-routine measurements. The second column lists the required Lower Limit of Detection (LLD) for those radionuclides that have detection capability requirements as specified in the ODCM Table 4.5.1. The absence of a value in this column indicates that no LLD is specified in the ODCM for that radionuclide in that media. The target LLD for any analysis is typically 50 percent of the most restrictive required LLD. Occasionally the required LLD may not be met. This may be due to malfunctions in sampling equipment or lack of sufficient sample quantity which would then result in low sample volume. Delays in analysis at the laboratory could also be a factor. Such cases, if and when they should occur, would be addressed in Section 6.2.

For each radionuclide and media type, the remaining three columns summarize the data for the following categories of monitoring locations: (1) the Indicator stations, which are within the range of influence of the plant and which could be affected by its operation; (2) the Control stations, which are beyond the influence of the plant; and (3) the station which had the highest mean concentration during 2022 for that radionuclide. Direct radiation monitoring stations (using TLDs) are grouped into Inner Ring, Outer ring, Site Boundary and Control.

In each of these columns, for each radionuclide, the following statistical values are given:

The mean value of all concentrations, including those results that are less than the a posteriori LLD for that analysis.

The minimum and maximum concentration, including those results that are less than the a VY 2022 AREOR Page 23 of 80

BVY 23-013 / Enclosure / Page 24 of 78 posteriori LLD. In previous years, data less than the a posteriori LLD were converted to zero for purposes of reporting the means and ranges.

The Number Detected is the number of positive measurements. A measurement is considered positive when the concentration is greater than three times the standard deviation in the concentration and greater than or equal to the a posteriori LLD (Minimum Detectable Concentration or MDC).

The Total Analyzed for each column is also given.

Each single radioactivity measurement datum in this report is based on a single measurement of a sample. Any concentration below the a posteriori LLD for its analysis is averaged with those values above the a posteriori LLD to determine the average of the results. Likewise, the values are reported in ranges even though they are below the a posteriori LLD. To be consistent with normal data review practices used by Vermont Yankee, a positive measurement is considered to be one whose concentration is greater than three times its associated standard deviation, is greater than or equal to the a posteriori LLD and satisfies the analytical laboratorys criteria for identification.

The radionuclides reported in this section represent those that: 1) had an LLD requirement in Table 4.5.1 of the ODCM, or a Reporting Level listed in Table 3.5.2 of the ODCM, or 2) had a positive measurement of radioactivity, whether it was naturally-occurring or man-made; or 3) were of special interest for any other reason. The radionuclides routinely analyzed and reported by the environmental laboratory (in a gamma spectroscopy analysis) were: Th-232, Ba/La-140, Be-7, Co-58, Co-60, Cs-134, Cs-137, Fe-59, K-40, Mn-54, Zn-65 and Zr-95.

Data from direct radiation measurements made by TLDs are provided in Table 5.2. The complete listing of quarterly TLD data is provided in Table 5.3.

VY 2022 AREOR Page 24 of 80

BVY 23-013 / Enclosure / Page 25 of 78 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL

SUMMARY

FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2022 Name of Facility: VERMONT YANKEE NUCLEAR POWER PLANT DOCKET NUMBER: 50-271 Location of Facility: VERNON, VT REPORTING PERIOD: 2022 INDICATOR CONTROL LOCATION WITH HIGHEST ANNUAL MEAN LOCATIONS LOCATION NUMBER MEDIUM OR TYPES OF OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE PERFORME OF (UNIT OF PERFORMED D DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT MEASUREMENT) (LLD) DIRECTION S AIR PARTICULATES GR-B 36 0.01 0.0164 0.0153 0.0170 12 INDICATOR 0 (PCI/M3) (24/24) (12/12) (12/12) N. HINSDALE NH

( 0.0081/ 0.0265) ( 0.0100/ 0.0225) ( 0.0094/ 0.0240) 3.6 KM NNW OF SITE GAMMA 12 BE-7 N/A 0.1092 0.1082 0.1140 12 INDICATOR 0 (8/8) (4/4) (4/4) N. HINSDALE NH

( 0.0753/ 0.1480) ( 0.0836/ 0.1415) ( 0.0776/ 0.1480) 3.6 KM NNW OF SITE K-40 N/A 0.0378 0.0423 0.0423 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)

(< 0.0239/< (< 0.0294/< (< 0.0294/<

0.0613) 0.0511) 0.0511) 16.4 KM NNE OF SITE CS-134 0.05 0.0023 0.0026 0.0026 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)

(< 0.0017/< (< 0.0022/< (< 0.0022/<

0.0034) 0.0028) 0.0028) 16.4 KM NNE OF SITE CS-137 0.06 0.0020 0.0022 0.0022 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)

(< 0.0015/< (< 0.0019/< (< 0.0019/<

0.0026) 0.0026) 0.0026) 16.4 KM NNE OF SITE RA-226 N/A 0.0314 0.0366 0.0366 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)

(< 0.0225/< (< 0.0318/< (< 0.0318/<

0.0407) 0.0393) 0.0393) 16.4 KM NNE OF SITE AC-228 N/A 0.0086 0.0102 0.0102 21 CONTROL 0 VY 2022 AREOR Page 25 of 78

BVY 23-013 / Enclosure / Page 26 of 78 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)

(< 0.0065/< (< 0.0068/< (< 0.0068/<

0.0123) 0.0129) 0.0129) 16.4 KM NNE OF SITE TH-228 N/A 0.0029 0.0035 0.0035 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)

(< 0.0021/< (< 0.0026/< (< 0.0026/<

0.0045) 0.0042) 0.0042) 16.4 KM NNE OF SITE RIVER WATER GR-B 24 4 1.928 2.074 2.074 21 CONTROL 0 (PCI/LITER) (3/12) (4/12) (4/12) ROUTE 9 BRIDGE 11.8 KM NNW OF

(< 1.610/ 2.900) (< 1.560/ 3.790) (< 1.560/ 3.790) SITE H-3 24 2000 516 531 531 21 CONTROL 0 (0/12) (0/12) (0/12) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<400/<577) (<382/<592) (<382/<592) SITE GAMMA 24 MN-54 15 1.993 2.024 2.024 21 CONTROL 0 (0/12) (0/12) (0/12) ROUTE 9 BRIDGE 11.8 KM NNW OF

(< 1.221/< 4.604) (< 1.529/< 4.180) (< 1.529/< 4.180) SITE CO-58 N/A 2.155 2.054 2.155 11 INDICATOR 0 (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(< 1.204/< 4.642) (< 1.485/< 4.006) (< 1.204/< 4.642) 1.9 KM SSE OF SITE FE-59 N/A 4.362 4.324 4.362 11 INDICATOR 0 (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(< 2.453/< 9.030) (< 3.046/< 9.034) (< 2.453/< 9.030) 1.9 KM SSE OF SITE CO-60 15 2.407 2.055 2.407 11 INDICATOR 0 (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(< 1.249/< 5.489) (< 1.598/< 3.170) (< 1.249/< 5.489) 1.9 KM SSE OF SITE ZN-65 30 4.370 4.220 4.370 11 INDICATOR 0 (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(< 2.505/< 9.711) (< 3.137/< 8.960) (< 2.505/< 9.711) 1.9 KM SSE OF SITE ZR-95 15 3.586 3.600 3.600 21 CONTROL 0 (0/12) (0/12) (0/12) ROUTE 9 BRIDGE 11.8 KM NNW OF

(< 2.315/< 7.127) (< 2.703/< 6.773) (< 2.703/< 6.773) SITE VY 2022 AREOR Page 26 of 78

BVY 23-013 / Enclosure / Page 27 of 78 I-131 N/A 3.515 3.559 3.559 21 CONTROL 0 (0/12) (0/12) (0/12) ROUTE 9 BRIDGE 11.8 KM NNW OF

(< 2.319/< 6.676) (< 2.025/< 6.728) (< 2.025/< 6.728) SITE RIVER WATER (cont'd) CS-134 15 2.022 1.981 2.022 11 INDICATOR 0 (PCI/LITER) (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(< 1.259/< 4.838) (< 1.460/< 3.894) (< 1.259/< 4.838) 1.9 KM SSE OF SITE CS-137 18 2.109 2.155 2.155 21 CONTROL 0 (0/12) (0/12) (0/12) ROUTE 9 BRIDGE 11.8 KM NNW OF

(< 1.210/< 4.012) (< 1.638/< 4.114) (< 1.638/< 4.114) SITE BA/LA-140 N/A 3.566 3.145 3.566 11 INDICATOR 0 (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(< 2.166/< 9.125) (< 2.023/< 6.331) (< 2.166/< 9.125) 1.9 KM SSE OF SITE RA-226 N/A 52.338 51.428 52.338 11 INDICATOR 0 (0/12) (0/12) (0/12) RIVER STA. NO. 3.3

(<32.56/<109.7) (<33.36/<100.4) (<32.56/<109.7) 1.9 KM SSE OF SITE GROUND WATER GR-B 12 4 4.026 2.283 4.205 12 INDICATOR 0 (PCI/LITER) (8/8) (2/4) (4/4) VERNON GREEN WELL

( 2.550/ 5.600) (< 1.270/ 3.770) ( 3.160/ 5.600) 2.1 KM SSE OF SITE H-3 12 2000 506 523 523 22 CONTROL 0 (0/8) (0/4) (0/4) COPELAND WELL

(<461/<566) (<478/<576) (<478/<576) 13.7 KM N OF SITE GAMMA 12 MN-54 15 1.826 1.579 1.984 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 1.325/< 2.372) (< 1.438/< 1.652) (< 1.535/< 2.372) 2.1 KM SSE OF SITE CO-58 N/A 1.862 1.699 2.030 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 1.285/< 2.445) (< 1.535/< 1.778) (< 1.508/< 2.445) 2.1 KM SSE OF SITE FE-59 N/A 4.027 3.401 4.340 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 2.483/< 4.942) (< 3.167/< 3.623) (< 3.229/< 4.942) 2.1 KM SSE OF SITE GROUND WATER (cont'd) CO-60 15 2.035 1.748 2.222 12 INDICATOR 0 (PCI/LITER) (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 1.367/< 2.421) (< 1.669/< 1.821) (< 1.653/< 2.421) 2.1 KM SSE OF SITE VY 2022 AREOR Page 27 of 78

BVY 23-013 / Enclosure / Page 28 of 78 ZN-65 30 3.974 3.296 4.386 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 3.051/< 5.937) (< 2.905/< 3.513) (< 3.051/< 5.937) 2.1 KM SSE OF SITE ZR-95 15 3.305 2.900 3.514 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 2.175/< 4.039) (< 2.665/< 3.085) (< 2.557/< 4.039) 2.1 KM SSE OF SITE CS-134 15 1.768 1.530 1.867 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 1.442/< 2.351) (< 1.458/< 1.631) (< 1.442/< 2.351) 2.1 KM SSE OF SITE CS-137 18 1.916 1.708 2.069 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 1.427/< 2.385) (< 1.565/< 1.777) (< 1.569/< 2.385) 2.1 KM SSE OF SITE BA/LA-140 N/A 3.356 2.956 3.450 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL

(< 2.027/< 4.163) (< 2.411/< 3.751) (< 2.391/< 4.101) 2.1 KM SSE OF SITE RA-226 N/A 46.561 42.308 46.58 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL

(<34.15/<65.13) (<34.32/<52.12) (<43/<50.66) 0.2 KM ON SITE SEDIMENT GAMMA 36 (PCI/KG DRY) BE-7 N/A 1027.82 1145.47 1449.6 21 CONTROL 0 (0/30) (0/6) (0/2) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<335.3/<1975) (<606.6/<1907) (<992.2/<1907) SITE K-40 N/A 16873.67 14564.83 20165 19 INDICATOR 0 (30/30) (6/6) (2/2) N. STORM DRAIN OUTFALL T-3 (10230/20600) (8290/20090) (19730/20600) 0.1 KM E OF SITE SEDIMENT (cont'd) MN-54 N/A 54.25 56.48 70.92 25 INDICATOR 0 (PCI/KG DRY) (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL U-4

(<18.68/<97.71) (<33.73/<88.4) (<44.12/<97.71) 0.1 KM E OF SITE CO-60 N/A 46.9 47.69 59.07 25 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL U-4

(<15.61/<89.46) (<28.68/<75.91) (<36.42/<81.72) 0.1 KM E OF SITE ZN-65 N/A 122.1 125.18 157.35 25 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL U-4

(<44.59/<198.2) (<72.69/<206.3) (<119.1/<195.6) 0.1 KM E OF SITE VY 2022 AREOR Page 28 of 78

BVY 23-013 / Enclosure / Page 29 of 78 NB-95 N/A 114.9 122.23 147.73 25 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL U-4

(<39.63/<201.2) (<72.09/<192.7) (<94.26/<201.2) 0.1 KM E OF SITE CS-134 150 43.31 42.55 58.14 25 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL U-4

(<15.34/<70.09) (<26.67/<64.89) (<46.18/<70.09) 0.1 KM E OF SITE CS-137 180 75.89 72.12 120.6 18 INDICATOR 0 (16/30) (3/6) (2/2) N. STORM DRAIN OUTFALL T-2

(<16.79/126) (<43.5/99.08) (116.2/125) 0.1 KM E OF SITE BA/LA-140 N/A 5661.3 5896.67 7268.5 21 CONTROL 0 (0/30) (0/6) (0/2) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<1320/<10930) (<2671/<9670) (<4867/<9670) SITE RA-226 N/A 2180.68 1729.92 2822.50 23 INDICATOR 0 (27/30) (3/6) (2/2) N. STORM DRAIN OUTFALL U-2 (952.5/3209) (<773.5/2437) (2436/3209) 0.1 KM E OF SITE AC-228 N/A 2172.78 1538.02 3582 23 INDICATOR 0 (26/30) (5/6) (2/2) N. STORM DRAIN OUTFALL U-2

(<196.4/4719) (<130.1/2831) (3336/3828) 0.1 KM E OF SITE SEDIMENT (cont'd) TH-228 N/A 1287.79 1157.08 1484 23 INDICATOR 0 (PCI/KG DRY) (30/30) (6/6) (2/2) N. STORM DRAIN OUTFALL U-2 (632.5/1500) (690.5/1518) (1468/1500) 0.1 KM E OF SITE TH-232 N/A 1065.32 1019.35 1303.5 24 CONTROL 0 (30/30) (6/6) (2/2) NORTH STORM DRAIN OUTFALL U-3 (556.5/1222) (618.6/1328) (1279/1328) 0.1 KM E OF SITE U-238 N/A 5021.63 5373.67 7158.5 25 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL U-4

(<1879/<10320) (<3189/<8115) (<3997/<10320) 0.1 KM E OF SITE TEST WELLS GR-B 16 4 4.5 N/A 5.0 17 INDICATOR 0 (PCI/LITER) (15/16) (4/4) S. FIELD WELL 203 (Septage Spreading Field) (< 1.1/ 7.1) ( 4.3/ 5.8) ON SITE H-3 16 2000 541 N/A 551.8 18 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 204 VY 2022 AREOR Page 29 of 78

BVY 23-013 / Enclosure / Page 30 of 78

(<476/<597) (<517/<588) ON SITE GAMMA 16 K-40 N/A 55.4 N/A 62.4 17 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 203

(<18.5/<166.1) (<18.5/<166.1) ON SITE MN-54 15 2.8 N/A 3.4 17 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 203

(< 1.2/< 8.3) (< 1.6/< 8.3) ON SITE CO-58 N/A 3.1 N/A 3.4 14 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 201

(< 1.1/< 8.1) (< 1.5/< 7.6) ON SITE TEST WELLS (cont'd) FE-59 N/A 6.4 N/A 7.8 14 INDICATOR 0 (PCI/LITER) (0/16) (0/4) S. FIELD WELL 201 (Septage Spreading Field) (< 2.6/<18) (< 3.6/<18) ON SITE CO-60 15 3.7 N/A 4.2 14 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 201

(< 1.2/<11.3) (< 1.8/<11.3) ON SITE NB-95 N/A 3.4 N/A 3.6 17 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 203

(< 1.4/< 8.4) (< 1.6/< 8.4) ON SITE I-131 N/A 7.1 N/A 7.8 17 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 203

(< 2.6/<14.1) (< 3.8/<14.1) ON SITE CS-134 15 3.0 N/A 3.7 14 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 201

(< 1.2/< 9.6) (< 1.5/< 9.6) ON SITE CS-137 18 3.2 N/A 3.5 17 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 203

(< 1.3/< 8.7) (< 1.7/< 8.7) ON SITE BA/LA-140 N/A 5.8 N/A 6.6 14 INDICATOR 0 (0/16) (0/4) S. FIELD WELL 201

(< 2.2/<13.3) (< 2.6/<13.3) ON SITE VY 2022 AREOR Page 30 of 78

BVY 23-013 / Enclosure / Page 31 of 78 SILAGE GAMMA 12 0 (PCI/KG WET) BE-7 N/A 168.51 718.43 718.43 22 CONTROL (1/8) (1/4) (1/4) FRANKLIN FARM

(<42.26/551.3) (<174.4/2288) (<174.4/2288) 9.7 KM WSW OF SITE 0

K-40 N/A 2897.46 11433.5 11433.5 22 CONTROL (8/8) (4/4) (4/4) FRANKLIN FARM (163.7/5005) (6459/18390) (6459/18390) 9.7 KM WSW OF SITE SILAGE (cont'd) CS-134 60 10.72 21.41 21.41 22 CONTROL 0 (PCI/KG WET) (0/8) (0/4) (0/4) FRANKLIN FARM

(< 4.34/<22.72) (<18.89/<28.32) (<18.89/<28.32) 9.7 KM WSW OF SITE CS-137 60 11.53 49.35 49.35 22 CONTROL 0 (0/8) (1/4) (1/4) FRANKLIN FARM

(< 5.20/<22.3) (<22.47/116.1) (<22.47/116.1) 9.7 KM WSW OF SITE AC-228 N/A 50.32 92.57 92.57 22 CONTROL 0 (0/8) (0/4) (0/4) FRANKLIN FARM

(<21.14/<100.7) (<85.7/<101.2) (<85.7/<101.2) 9.7 KM WSW OF SITE TH-228 N/A 25.17 45.28 45.28 22 CONTROL 0 (1/8) (1/4) (1/4) FRANKLIN FARM

(< 8.47/54.63) (<33.95/<64.73) (<33.95/<64.73) 9.7 KM WSW OF SITE MIXED GRASS GAMMA 9 (PCI/KG WET) BE-7 N/A 1634.2 1338.13 2551.2 12 INDICATOR 0 (4/6) (2/3) (3/3) N. HINSDALE NH

(<225.9/4970) (<203.4/2765) (570.6/4970) 3.6 KM NNW OF SITE K-40 N/A 4830 3676 4857 11 INDICATOR 0 (6/6) (3/3) (3/3) RIVER STA. NO. 3.3 (3151/6195) (2904/4345) (3151/6195) 1.9 KM SSE OF SITE I-131 N/A 37.39 35.38 39.75 12 INDICATOR 0 (0/6) (0/3) (0/3) N. HINSDALE NH

(<16.19/<81.7) (<20.66/<49.46) (<16.19/<81.7) 3.6 KM NNW OF SITE CS-134 60 16.3 18.13 18.6 11 INDICATOR 0 (0/6) (0/3) (0/3) RIVER STA. NO. 3.3

(<11.81/<23.76) (<12.28/<22.37) (<13.27/<23.76) 1.9 KM SSE OF SITE CS-137 60 23.86 20.61 26.93 12 INDICATOR 0 (1/6) (0/3) (1/3) N. HINSDALE NH

(<13.59/45.59) (<14.51/<29.06) (<13.59/45.59) 3.6 KM NNW OF SITE VY 2022 AREOR Page 31 of 78

BVY 23-013 / Enclosure / Page 32 of 78 MIXED GRASS (cont'd) RA-226 N/A 403.83 426.73 451.83 11 INDICATOR 0 (PCI/KG WET) (0/6) (0/3) (0/3) RIVER STA. NO. 3.3

(<302.2/<543.2) (<249.2/<556.3) (<336.8/<543.2) 1.9 KM SSE OF SITE AC-228 N/A 85.72 94.11 94.66 11 INDICATOR 0 (0/6) (0/3) (0/3) RIVER STA. NO. 3.3

(<59.49/<135.5) (<61.33/<116.9) (<63.79/<135.5) 1.9 KM SSE OF SITE TH-228 N/A 30.77 35.38 35.38 21 CONTROL 0 (0/6) (0/3) (0/3) SPOFFORD LAKE (9)

(<22.46/<40.84) (<22.89/<41.82) (<22.89/<41.82) 16.4 KM NNE OF SITE FISH GAMMA 8 (PCI/KG WET) K-40 N/A 2685.5 2893.25 2893.25 21 CONTROL 0 (4/4) (4/4) (4/4) ROUTE 9 BRIDGE 11.8 KM NNW OF (2181/3113) (2345/3474) (2345/3474) SITE MN-54 130 18.763 18.053 18.763 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(<16.21/<20.01) (<16.29/<20.11) (<16.21/<20.01) 0.6 KM SSE OF SITE CO-58 N/A 35.635 33.87 35.635 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(<32.33/<39.84) (<30.92/<38.3) (<32.33/<39.84) 0.6 KM SSE OF SITE FE-59 N/A 118.9 112.7 118.9 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(<108.1/<125.1) (<102.5/<119.9) (<108.1/<125.1) 0.6 KM SSE OF SITE CO-60 130 17.35 16.75 17.35 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(<15.5/<19.1) (<15.79/<17.54) (<15.5/<19.1) 0.6 KM SSE OF SITE ZN-65 260 40.515 41.803 41.803 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<36.15/<45.87) (<38.18/<46.36) (<38.18/<46.36) SITE FISH (cont'd) CS-134 130 16.038 16.363 16.363 21 CONTROL 0 (PCI/KG WET) (0/4) (0/4) (0/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<14.44/<17.74) (<15.08/<17.74) (<15.08/<17.74) SITE CS-137 150 16.75 16.83 16.83 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE VY 2022 AREOR Page 32 of 78

BVY 23-013 / Enclosure / Page 33 of 78 11.8 KM NNW OF

(<15.2/<18.82) (<15.15/<18.46) (<15.15/<18.46) SITE H-3 4 0.2 220 222 222 21 CONTROL 0 (0/2) (0/2) (0/2) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<100/<341) (<54/<391) (<53/<391) SITE AM-241 8 N/A 2.544 2.269 2.544 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(< 1.742/< 2.971) (< 1.061/< 5.039) (< 1.742/< 2.971) 0.6 KM SSE OF SITE CM-242 8 N/A 0.672 0.844 0.844 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(< 0.510/< 1.053) (< 0.457/< 1.802) (< 0.457/< 1.802) SITE CM-243/244 8 N/A 0.687 0.661 0.687 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(< 0.431/< 1.290) (< 0.323/< 1.041) (< 0.431/< 1.290) 0.6 KM SSE OF SITE FE-55 8 N/A 599.925 924.375 924.375 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<256.5/<1058) (<491.9/<1373) (<491.9/<1373) SITE NI-63 8 N/A 72.7 77.75 77.75 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<47.9/<103) (<51.7/<112) (<51.7/<112) SITE PU-238 8 N/A 2.538 1.413 2.538 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(< 2.172/< 2.855) (< 1.176/< 1.721) (< 2.172/< 2.855) 0.6 KM SSE OF SITE FISH (cont'd) PU-239/240 8 N/A 1.386 0.858 1.386 11 INDICATOR 0 (PCI/KG WET) (0/4) (0/4) (0/4) VERNON POND

(< 0.821/< 2.048) (< 0.619/< 1.358) (< 0.821/< 2.048) 0.6 KM SSE OF SITE PU-241 8 N/A 274 163.5 274 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(<228/<345) (<115/<200) (<228/<345) 0.6 KM SSE OF SITE PU-242 8 N/A 1.046 0.616 1.046 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND

(< 0.349/< 1.998) (< 0.186/< 0.960) (< 0.349/< 1.998) 0.6 KM SSE OF SITE VY 2022 AREOR Page 33 of 78

BVY 23-013 / Enclosure / Page 34 of 78 SR-89 8 N/A 367.25 435 435 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<224/<490) (<241/<734) (<241/<734) SITE SR-90 8 60 18.75 33.725 33.725 21 CONTROL 0 (2/4) (1/4) (1/4) ROUTE 9 BRIDGE 11.8 KM NNW OF

(<10.8/25.7) (<11.7/79.7) (<11.7/79.7) SITE TLD-DIRECT RADIATION QUARTERLY 36 N/A 7.0 7.0 9.9 DR45 INDICATOR 0 (MILLI-ROENTGEN/QTR.) (32/32) (4/4) (4/4) SITE BOUNDARY (6/11) (6/7) ( 9/11) 0.12 KM NE OF SITE VY 2022 AREOR Page 34 of 78

BVY 23-013 / Enclosure / Page 35 of 78 VY 2022 AREOR Page 35 of 78

BVY 23-013 / Enclosure / Page 36 of 78 TABLE 5.3 ENVIRONMENTAL TLD MEASUREMENTS 2022 (Micro-R per Hour)

ANNUAL Sta. 1ST QUARTER 2ND QUARTER 3RD QUARTER 4TH QUARTER AVE.

No. Description EXP. S.D. EXP. S.D. EXP. S.D. EXP. S.D. EXP.

DR-01 River Sta. No. 3.3 5.64 +/- 0.22 6.01 +/- 0.25 6.13 +/- 0.16 5.92 +/- 0.20 5.9 DR-02 N Hinsdale, NH 6.16 +/- 0.26 6.56 +/- 0.27 7.10 +/- 0.28 6.92 +/- 0.22 6.7 DR-05 Spofford Lake, NH 6.21 +/- 0.24 6.88 +/- 0.30 6.81 +/- 0.25 6.74 +/- 0.20 6.7 DR-06 Vernon School 6.23 +/- 0.27 6.48 +/- 0.25 7.06 +/- 0.21 6.84 +/- 0.27 6.7 DR-07 Site Boundary 6.63 +/- 0.26 0.00 +/- 0.00 6.92 +/- 0.37 6.95 +/- 0.30 5.1 DR-08 Site Boundary 6.28 +/- 0.28 6.66 +/- 0.38 7.12 +/- 0.25 7.26 +/- 0.38 6.8 DR-43 Site Boundary 6.45 +/- 0.30 6.44 +/- 0.33 7.19 +/- 0.29 6.83 +/- 0.34 6.7 DR-45 Site Boundary 10.31 +/- 0.44 9.15 +/- 0.36 9.28 +/- 0.41 10.81 +/- 0.50 9.9 DR-46 Site Boundary 7.18 +/- 0.48 6.79 +/- 0.29 7.30 +/- 0.20 7.81 +/- 0.37 7.3 DR-53A West Cornfield 6.52 +/- 0.38 7.36 +/- 0.22 8.05 +/- 0.31 7.75 +/- 0.26 7.4 VY 2022 AREOR Page 36 of 78

BVY 23-013 / Enclosure / Page 37 of 78

6. ANALYSIS OF ENVIRONMENTAL RESULTS 6.1 Sampling Program Deviations Off-site Dose Calculation Manual Control 3.5.1 allows for deviations if specimens are unobtainable due to hazardous conditions, seasonal unavailability, malfunction of automatic sampling equipment and other legitimate reasons. In 2022, nine deviations were noted in the REMP. These deviations did not compromise the programs effectiveness and are considered typical with respect to what is normally anticipated for any radiological environmental program. The specific deviations for 2022 were:

a) Environmental Air Sampling Station # 11 (AP-11, located at River Station No. 3.3) air pump was found to be out of service on 01/25/2022 (Week 4-22). The loss of power for approximately 175 hours0.00203 days 0.0486 hours 2.893519e-4 weeks 6.65875e-5 months . Documented in Condition Report CR-VTY-2022-000061.

b) Environmental Air Sampling Station # 21 (AP-21, located in Spofford, New Hampshire) air pump had a temporary loss of power on 02/22/2022 (Week 8-22). The loss of power for approximately 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . Documented in Condition Report CR-VTY-2022-000061.

c) Environmental Air Sampling Stations # 11, #12, #21 (AP-11, located at River Station No. 3.3, AP-12, located in N. Hinsdale, NH, and AP-21, located in Spofford, New Hampshire) sample timers were short by one hour due to entry into Daylight Savings Time (DST) on 3/29/2022 (Week 13-22)

Documented in Condition Report CR-VTY-2022-000061.

d) Environmental Air Sampling Station # 12 (AP-12, located in N. Hinsdale, NH) air pump had a temporary loss of power on 06/29/2022 (Week 26-22). The loss of power for approximately 1.3 hours3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months .

Documented in Condition Report CR-VTY-2022-000061.

e) Environmental Air Sampling Stations # 11 (AP-11, located at River Station No. 3.3) air pumps were found to be out of service on 09/27/2022 (Week 39-22). The loss of power for approximately 137 hour0.00159 days 0.0381 hours 2.265212e-4 weeks 5.21285e-5 months was due to a blown fuse and sample motor burn out. Documented in Condition Report CR-VTY-2022-000061.

f) Environmental Air Sampling Stations # 11, 12, and 21 (AP-11, located at River Station No. 3.3, AP-12, located in N. Hinsdale, NH, and AP-21, located in Spofford, New Hampshire) sample timers were increased by one hour due to the end of Daylight Savings Time (DST) on 11/29/2022 (Week 48-22)

Documented in Condition Report CR-VTY-2022-000061.

g) Environmental Air Sampling Station # 12 and 21 (AP-12, located in N. Hinsdale, NH and AP-21, located in Spofford, New Hampshire) air pump had a temporary loss of power on 11/29/2022 (Week 48-22). The loss of power for approximately 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . Documented in Condition Report CR-VTY-2022-000061.

VY 2022 AREOR Page 37 of 78

BVY 23-013 / Enclosure / Page 38 of 78 h) Eight of Eighteen river sediment samples in the shipping container received by Teledyne Brown Engineering on 8/10/22 had damaged lids. Sediment samples SEVxx1922 were collected by Normandeau Associates Inc (NAI) on 5/10/22, packed and shipped by NAI on 8/9/22. All damaged sample lids were on the bottom layer of the shipping container. The normal sample container lids were unavailable, and a less robust lid was used instead. It appeared no sample was lost. Documented in Condition Report 2022-0100.

i) On Friday June 17th at ~1800 the night crew RP Shift Tech, while completing his rounds, found that the RB HVAC particulate sampling systems were not running. The night crew RP Shift Tech reported this to the oncoming day crew RP Shift Tech and stated that he believed they had been running the night before. The day crew RP Shift Tech investigated and found that the air sampling systems had been unplugged from their extension cord (which was labeled Do Not Touch/Disturb). The RP Tech plugged the vacuum sampling pumps in and verified their respective flow rates.

The RB HVAC particulate filter samples were collected on Monday June 20th. The total volume of sample collected is registered on the calibrated gas meters. The Chemistry/Environmental personnel calculated that the sample systems had been off for ~49 hours during the 168 hour0.00194 days 0.0467 hours 2.777778e-4 weeks 6.3924e-5 months collection period.

Dose ground level release calculations were calculated and reported for the entire period of ~168 hours.

Upon further investigation it was discovered that a demolition crew had been working in the area removing cable trays which the sampling systems extension cord had been routed over. This was brought up at a morning meeting on Monday June 20th. One of the demolition crew members stated that he had unplugged the extension cord as to not damage it and had forgotten to plug it back in.

These sampling systems are required and provide data per ODCM requirements for dose calculations and monitoring of potential ground level releases to the general public, the environment and plant personnel. The deficit of 49 hours5.671296e-4 days 0.0136 hours 8.101852e-5 weeks 1.86445e-5 months and this Condition Report (CR-2022-0098) will be noted in the 2022 RETS/REMP program annual report completed in May of 2023. An additional corrective action will be initiated to track this to ensure that the deficiency is entered into annual reports. Documented in Condition Report 2022-0100.

Air sample station outages during 2022 are reflected in the air sample collection time percentages listed below.

AP/CF 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 11 100.0% 101.1% 92.6% 100.0%

12 100.1% 101.0% 98.9% 100.0%

21 99.9% 101.1% 98.9% 100.0%

6.2 Comparison of Achieved LLDs with Requirements Table 4.5.1 of the VY ODCM (also shown in Table 4.4 of this report) gives the required Lower Limits of Detection (LLDs) for environmental sample analyses. On occasion, an LLD is not achievable due to a situation such as a low sample volume caused by sampling equipment malfunction or limited sample VY 2022 AREOR Page 38 of 78

BVY 23-013 / Enclosure / Page 39 of 78 availability. In such a case, ODCM 10.2 requires a discussion of the situation. At the contracted environmental laboratory, the target LLD for the majority of analyses is 50 percent of the most restrictive required LLD. Expressed differently, the typical sensitivities achieved for each analysis are at least 2 times greater than that required by the VY ODCM.

For each analysis having an LLD requirement in ODCM Table 4.5.1, the a posteriori (after the fact)

LLD calculated for that analysis was compared with the required LLD. During 2022, all sample analyses performed for the REMP program achieved an a posteriori LLD less than the corresponding LLD requirement.

6.3 Comparison of Results with Reporting Levels ODCM Section 10.3.4 requires written notification to the NRC within 30 days of receipt of an analysis result whenever a Reporting Level in ODCM Table 3.5.2 is exceeded. Reporting Levels are the environmental concentrations that relate to the ALARA design dose objectives of 10 CFR 50, Appendix I. Environmental concentrations are averaged over the calendar quarters for the purposes of this comparison. The Reporting Levels are intended to apply only to measured levels of radioactivity due to plant effluents. During 2022, no analytical result exceeded a corresponding reporting level requirement in Table 3.5.2 of the ODCM.

6.4 Changes in Sampling Locations The Vermont Yankee Nuclear Power Station Off-Site Dose Calculation Manual Section 10.2 states that if new environmental sampling locations are identified in accordance with Control 3.5.2, the new locations shall be identified in the next Annual Radiological Environmental Operating Report. There were no required sampling location changes due to the Land Use Census conducted in 2022.

Milk collection from Dunklee farm (Vern-Mont Farm in Vernon) commenced in April, 2010 at the request of the farm owner. After the shutdown of Vermont Yankee, sampling from this location was terminated in August 2015. All milk sampling was terminated by the implementation of ODCM Rev 37 in December 2016 due to the decay of radioiodines following shutdown.

VY 2022 AREOR Page 39 of 78

BVY 23-013 / Enclosure / Page 40 of 78 6.5 Data Analysis by Media Type The 2022 REMP data for each media type is discussed below. Whenever a specific measurement result is presented, it is given as the concentration in the units of the sample (volume or weight). An analysis is considered to yield a detectable measurement when the concentration exceeds three times the standard deviation for that analysis and is greater than or equal to the Minimum Detectable Concentration (MDC) for the analysis. With respect to data plots, all net concentrations are plotted as reported, without regard to whether the value is detectable or non-detectable. In previous years, values that were less than the MDC were converted to zero.

6.5.1 Airborne Pathways 6.5.1.1 Air Particulates (AP)

The periodic air particulate filters from each of the three sampling sites were analyzed for gross-beta radioactivity. At the end of each quarter, the filters from each sampling site were composited for a gamma analysis. The results of the air particulate sampling program are shown in Table 5.1 and Figures 6.1 through 6.7.

Gross beta activity was detected in all of the air particulate filters that were analyzed. As shown in Figure 6.1, there is no significant difference between the quarterly average concentrations at the indicator (near-plant) stations and the control (distant from plant) stations. Notable in Figure 6.1 is a distinct annual cycle, with the minimum concentration in the fourth quarter, and the maximum concentration in the third quarter.

Figures 6.2 through 6.7 show the monthly gross beta concentration at each air particulate sampling location compared to the control air particulate sampling location at AP-21 (Spofford Lake, NH). Small differences are evident and expected between individual sampling locations. Figure 6.2 clearly demonstrates the distinct annual cycle, with the minimum concentration in the second quarter, and the maximum concentration in the first quarter. It can be seen that the gross-beta measurements on air particulate filters fluctuate significantly over the course of a year. The measurements from control station AP-21 vary similarly, indicating that these fluctuations are due to regional changes in naturally-occurring airborne radioactive materials, and not due to Vermont Yankee operations.

There was one naturally-occurring gamma-emitting radionuclides detected on the air particulate filters VY 2022 AREOR Page 40 of 78

BVY 23-013 / Enclosure / Page 41 of 78 during this reporting period. Be-7, a naturally-occurring cosmogenic radionuclide, was detected on all 12 filter sets analyzed.

6.5.1.2 Charcoal Cartridges (CF)

Charcoal cartridges are no longer analyzed as part of the Environmental Monitoring Program.

6.5.2 Waterborne Pathways 6.5.2.1 River Water (WR)

Monthly grab samples of river water were collected from the Connecticut River downstream from the plant discharge area and hydro station, location WR-11 and upstream control location WR-21. The samples from WR-11 and WR-21 were sent to the contracted environmental laboratory for analysis. Table 5.1 shows that gross-beta measurements were positive in three out of 12 indicator samples as would be expected due to naturally-occurring radionuclides in the water. Gross-beta was detected in four of the 12 control samples. As seen in Figure 6.8, the mean concentration of the indicator locations was similar to the mean concentration at the control location in 2022.

For each sampling site, the monthly samples were analyzed for H-3 (Tritium) analyses. None of the samples contained detectable quantities of H-3.

6.5.2.2 Ground Water - Potable Drinking Water (WG)

Quarterly ground water (deep wells supplying drinking water to the plant and selected offsite locations) samples were collected from two indicator locations (only one is required by VY ODCM) and one control location during 2022. In 1999, WG-14 (PSB Well) another on-site well location was added to the program. In July 2012, WG-15 (Southwest Well) was added to the ODCM as a quarterly sample location. Table 5.1 and Figure 6.9 show that gross-beta measurements were positive in all eight indicator samples and in two out of four control samples. The beta activity is due to naturally-occurring radionuclides in the water. The levels at all sampling locations were consistent with those detected in previous years. No other gamma-emitting radionuclides or tritium were detected in any of the samples.

VY 2022 AREOR Page 41 of 78

BVY 23-013 / Enclosure / Page 42 of 78 6.5.2.3 Sediment (SE)

Semi-annual river sediment grab samples were collected from two indicator locations during 2022. The North Storm Drain Outfall location (SE-12) is an area where up to 40 different locations can be sampled within a 20 ft by 140 ft area. In 2022, 15 locations were sampled at SE-12 during each of the semi-annual collections. Two samples were collected at SE-11 during the year. As would be expected, naturally-occurring Potassium-40 (K-40) was detected in all of the samples. Cobalt-60 was not detected in any of the samples. Radium-226 (Ra-226) was detected in 30 of 36 samples. Actinium-228 (Ac-228) was detected in 31 of 36 samples. Thorium-228 (Th-228) was detected in all of the samples analyzed.

Thorium-232 (Th-232) was detected in all of the 36 samples analyzed. Uranium-238 (U-238) was not detected in any of the 36 samples. Cesium-137 (Cs-137) was detected in 19 out of the 36 samples. The levels of Cs-137 measured were consistent with what has been measured in the previous several years and with those detected at other New England locations. Also see section 6.5.2.6 for more information.

6.5.2.4 Test Wells (WT)

During 1996, sampling was initiated at test wells around the outer edges of an area in the south portion of the VY site where septic sludge is spread. This sampling continued through 2022. The test wells are summarized in Table 5.1 under the media category, Test Well (WT). In 2022, samples were taken quarterly at each of the four locations and all were analyzed for gamma isotopic, gross beta and H-3 activity.

Prior to the gross beta analysis, each sample was filtered through a 0.45 micron Gelman Tuffryn membrane filter. Gross beta activity was detected in 15 of the 16 samples collected with levels ranging from <1.1 to 7.1 pCi/Liter. No gamma-emitting radionuclides were detected.

6.5.2.5 Storm Drain System The presence of plant-generated radionuclides in the onsite storm drain system has been identified in previous years at Vermont Yankee (VY). As a consequence, a 50.59 evaluation of radioactive materials discharged via the storm drain system was performed in 1998. This assessment was in response to Information and Enforcement Bulletin No. 80-10 and NRC Information Notice No. 91-40. The evaluation demonstrated that the total curies released via the VY storm drain system are not sufficient to result in a significant dose (i.e. dose does not exceed 10% of the technical specification objective of 0.3 millirem VY 2022 AREOR Page 42 of 78

BVY 23-013 / Enclosure / Page 43 of 78 per year to the total body, and 1.0 millirem per year to the target organ for the maximally exposed receptor). Water in the onsite storm drain system was routinely sampled throughout 2022 at the south storm drain. These samples are analyzed for tritium; no tritium was detected in any sample. A gamma isotopic analysis was also completed monthly on the Storm Drain System and no plant related isotopes were detected.

6.5.2.6 Air Compressor Condensate and Manhole Sampling Results The presence of tritium in station air compressor condensate and manholes (Storm Drain System) has been identified since 1995 (ER_95-0704). An evaluation has been performed (S.R.1592) which states leakage of tritium found in the storm drains (manholes) to ground water beneath the site will be transported by natural ground water gradient to the Connecticut River. However, at the current measured concentrations and postulated leak rate from the storm drains, the offsite dose impact is not significant (<2.4E-5 mrem/year). Data provided in Table 6.1 will be filed under the requirements of 10 CFR 50.75(g) and is presented here in response to ER_95-0704_04 commitments. Because of revisions in the security arrangements at the plant site, there was no water available for collection in Manholes 11H, 13 and 8 during 2022. Collection from the Air Compressor drains has been discontinued due to there being no source of tritium to the compressor air intakes and the drain were redirected.

6.5.2.7 Groundwater Monitoring Wells Samples Results (WS)

Leakage from primary system piping between the Augmented Off Gas (AOG) Building and the Turbine Building was identified early in 2010. A large pool of subsurface water became contaminated with Tritium as a result of this leak. A large number of new groundwater sample wells were installed and a significant effort was mounted to find the leak and fix it. Presently, mitigation efforts have resulted in the extraction of more than 300,000 gallons of tritiated water from this subsurface pool. Dose calculations have been performed assuming that this underground plume of contaminated water is moving towards and into the Connecticut River. The dose impacts and other details of this event are provided in the year 2022 Annual Radioactive Effluent Release Report.

VY 2022 AREOR Page 43 of 78

BVY 23-013 / Enclosure / Page 44 of 78 6.5.3 Ingestion Pathways 6.5.3.1 Milk (TM)

As a result of re-evaluation of source terms (and subsequent revision of the Vermont Yankee Offsite Dose Calculation Manual) which identified that radioiodine releases were no longer of measurable significance in plant releases, no milk samples were collected or analyzed during 2022.

6.5.3.2 Silage (TC)

A silage sample was collected from each of the three Land Use Census-identified farm locations during each quarter of 2022. Each of these was analyzed for gamma-emitting radionuclide. As expected with all biological media, naturally-occurring Be-7 was detected in two of 12 samples and K-40 was detected in all samples. Cs-137 was detected in one of the 12 samples analyzed. Naturally occurring Thorium-228 (Th-228) was detected in two of the 12 samples analyzed.

6.5.3.3 Mixed Grass (TG)

Mixed grass samples were collected at each of the air sampling stations during three of the four quarters of 2022. As expected with all biological media, naturally-occurring Be-7 was detected in six of the nine samples collected. Naturally-occurring K-40 was detected in all nine samples.

6.5.3.4 Fish (FH)

Semiannual samples of fish were collected from two locations in both spring and fall of 2022 for the VY REMP. Several species may be collected such as Small Mouth Bass, Large Mouth Bass, Yellow Perch, and Northern Pike. The edible portions of each of these were analyzed for gamma-emitting radionuclides. In addition to the analysis of edible portions, the inedible portions were also analyzed.

As expected in biological matter, naturally-occurring K-40 was detected in all eight samples (4 edible and 4 inedible). These fish portions were also analyzed for H-3, Am-241, Cm-242, Cm-243/244, Fe-55, Ni-63, Pu-238, Pu-239/240, Pu-241, Pu-242, Sr-89 and Sr-90.

Strontium 90 was detected in three of the four inedible portions (bones, guts and skin are included in the inedible portion). This is the twelfth year in the VY REMP program that fish has been analyzed for Hard-to-Detects such as Strontium-90. The results were compared to studies done in the Hudson River by New York State officials and it was concluded that the Strontium-90 detected is a result of weapons-VY 2022 AREOR Page 44 of 78

BVY 23-013 / Enclosure / Page 45 of 78 testing era fallout to the environment and not from nuclear power plant releases.

As shown in Table 5.1, Cs-137 was not detected in this years samples. It should be noted that the majority of the Cs-137 concentrations plotted in Figure 6.12 are considered not detectable. All values were plotted regardless of whether they were considered statistically significant or not. The Cs-137 levels plotted for 2014 and previous years are typical of concentrations attributable to global nuclear weapons testing fallout.

6.5.4 Direct Radiation Pathway Direct radiation was continuously measured at 11 locations surrounding the Vermont Yankee plant with the use of thermoluminescent dosimeters (TLDs).

The TLDs are collected every calendar quarter for readout at the environmental TLD laboratory. The complete summary of data may be found in Table 5.3.

From Tables 5.2 and 5.3 and Figure 6.13, it can be seen that the Inner and Outer Ring TLD mean exposure rates were not significantly different in 2022. This indicates no significant overall increase in direct radiation exposure rates in the plant vicinity. It can also be seen from these tables that the Control TLD mean exposure rate was not significantly different than that at the Inner and Outer Rings. Figure 6.13 also shows an annual cycle at both indicator and control locations. The lowest point of the cycle occurs usually during the winter months. This is due primarily to the attenuating effect of the snow cover on radon emissions and on direct irradiation by naturally-occurring radionuclides in the soil. Differing amounts of these naturally-occurring radionuclides in the underlying soil, rock or nearby building materials result in different radiation levels between one field site and another.

Upon examining Figure 6.17, as well as Table 5.2, it is evident that in recent years, station DR-45 had a higher average exposure rate than any other station. This location is on-site, and the higher exposure rates are due to plant operations and activities in the immediate vicinity of this TLD. There is no significant dose potential to the surrounding population or any real individual from these sources since they are located on the back side of the plant site, between the facility and the river. The same can be said for station DR-46, which has shown higher exposure rates in previous years.

VY 2022 AREOR Page 45 of 78

BVY 23-013 / Enclosure / Page 46 of 78 Table 6.2 Trend Graph Summary Table Figure Title 6.1 Gross Beta Measurements on Air Particulate Filters - Quarterly Average Concentrations 6.2 Gross Beta Measurements on Air Particulate Filters (11) 6.3 Gross Beta Measurements on Air Particulate Filters (12) 6.4 Deleted 6.5 Deleted 6.6 Deleted 6.7 Deleted 6.8 Gross Beta Measurements on River Water Semi-Annual Average Concentrations 6.9 Gross Beta Measurements on Ground Water Semi-Annual Average Concentrations 6.10 Deleted 6.11 Deleted 6.12 Cesium-137 in Fish - Annual Average Concentrations 6.13 Average Exposure Rate at Inner Ring, Outer Ring, and Control TLDS Figure Title 6.14 Exposure Rate at Indicator TLDs, DR1-3 6.15 Exposure Rate at Indicator TLDs, DR-6 & DR-50 6.16 Exposure Rate at Site Boundary TLDs DR-7, DR-8 and DR-53A 6.17 Exposure Rate at Site Boundary TLDs DR-43 thru DR-46 6.18 Deleted 6.19 Deleted 6.20 Deleted 6.21 Deleted 6.22 Deleted 6.23 Deleted 6.24 Deleted 6.25 Deleted 6.26 Deleted 6.27 Exposure Rate at Control TLDs DR-4 & 5 Note: No year 2022 data was obtained from locations previously provided in Deleted graphs due to ODCM changes implemented in January 2017 as a result of source term changes in the plant. These graphs may be viewed in the year 2016 Annual Radiological Environmental Operating Report (AREOR) for comparison purposes.

VY 2022 AREOR Page 46 of 78

BVY 23-013 / Enclosure / Page 47 of 78 Figure 6.1 - Gross Beta Measurements on Air Particulate Filters -

Quarterly Average Concentrations 0.08 0.07 0.06 0.05 pCi/cubic meter 0.04 0.03 0.02 0.01 0

Year Indicator Stations Control Station VY 2022 AREOR Page 47 of 78

BVY 23-013 / Enclosure / Page 48 of 78 Figure 6.2 - Gross Beta Measurements on Air Particulate Filters 0.08 0.07 0.06 0.05 pCi/cubic meter 0.04 0.03 0.02 0.01 0 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8 7

6 5

4 3

2 1

0 2022 Week Number AP-11 Riv er Station No. 3.3 AP-21 Spof f ord Lake VY 2022 AREOR Page 48 of 78

BVY 23-013 / Enclosure / Page 49 of 78 Figure 6.3 - Gross Beta Measurements on Air Particulate Filters 0.08 0.07 0.06 0.05 pCi/cubic meter 0.04 0.03 0.02 0.01 0 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9

8 7

6 5

4 3

2 1

0 2022 Week Number AP-12 N. Hinsdale NH AP-21 Spof f ord Lake VY 2022 AREOR Page 49 of 78

BVY 23-013 / Enclosure / Page 50 of 78 Figure 6.8 - Gross Beta Measurements on River Water Semi-Annual Average Concentration 4.00 3.50 3.00 2.50 pCi/Liter 2.00 1.50 1.00 0.50 0.00 Year WR-11 River Station No. 3.3 WR-21 Rt.9 Bridge VY 2022 AREOR Page 50 of 78

BVY 23-013 / Enclosure / Page 51 of 78 Figure 6.9 - Gross Beta Measurements on Ground Water Semi-Annual Average Concentrations 11.0 10.0 9.0 8.0 7.0 6.0 pCi/Liter 5.0 4.0 3.0 2.0 1.0 0.0 Year WG-11 Plant Well WG-12 Vernon Nursing Well WG-22 Copeland Well WG-13 COB Well WG-14 Plant Support Bldg Well WG-15 Southwest Well VY 2022 AREOR Page 51 of 78

BVY 23-013 / Enclosure / Page 52 of 78 Figure 6.12 - Cesium 137 in Fish - Annual Average Concentrations 80.0 70.0 60.0 50.0 40.0 pCi/kg 30.0 20.0 10.0 0.0 Note: In 2005 sw itched to reporting < MDA w hen no activity Year FH-11 Vernon Pond FH-21 Rt. 9 Bridge (Control)

VY 2022 AREOR Page 52 of 78

BVY 23-013 / Enclosure / Page 53 of 78 Figure 6.13 - Average Exposure Rate at Inner Ring, Outer Ring and Control TLDs 9.0 8.5 8.0 7.5 7.0 Micro-R per hour 6.5 6.0 5.5 5.0 4.5 4.0 Retrieval Date Control Inner Ring Outer Ring VY 2022 AREOR Page 53 of 78

BVY 23-013 / Enclosure / Page 54 of 78 Figure 6.14 - Exposure Rate at Indicator TLDs, DR1-3 10.0 9.5 TLD sampling from 9.0 locaons DR-3 was disconnued in 2019 8.5 due to plant shutdown and ODCM revision.

8.0 7.5 Micro-R per hour 7.0 6.5 6.0 5.5 5.0 4.5 4.0 Retrieval Date DR-1 River Sta. No. 3.3 DR-2 N. Hinsdale, NH DR-3 Hinsdale Substation VY 2022 AREOR Page 54 of 78

BVY 23-013 / Enclosure / Page 55 of 78 Figure 6.15 - Exposure Rate at Indicator TLDs, DR-6 & DR-50 10.0 9.5 TLD sampling from 9.0 locaons DR-50 was disconnued in 2019 8.5 due to plant shutdown and ODCM revision.

8.0 7.5 Micro-R per hour 7.0 6.5 6.0 5.5 5.0 4.5 4.0 Retrieval Date DR-6 Vernon School DR-50 Gov. Hunt House VY 2022 AREOR Page 55 of 78

BVY 23-013 / Enclosure / Page 56 of 78 Figure 6.16 - Exposure Rate at Site Boundary TLDs DR-7, DR-8 and DR-53A 11 10 9

8 Micro-R per Hour 7

6 5

4 Retrieval Date DR-7 Site Boundary (C) DR-8 Site Boundary DR-53A Site Boundary VY 2022 AREOR Page 56 of 78

BVY 23-013 / Enclosure / Page 57 of 78 Figure 6.17 - Exposure Rate at Site Boundary TLDs - DR-43 thru 46 19 18 17 TLD sampling from 16 locaons DR-44 was disconnued in 2019 15 due to plant shutdown 14 and ODCM revision.

13 Micro-R per hour 12 11 10 9

8 7

6 5

4 Retrieval Date DR-43 Site Boundary DR-44 Site Boundary DR-45 Site Boundary DR-46 Site Boundary VY 2022 AREOR Page 57 of 78

BVY 23-013 / Enclosure / Page 58 of 78 Figure 6.27 - Exposure Rate at Control TLDs DR-4 & 5 9

8.5 8 TLD sampling from locaons DR-4 was 7.5 disconnued in 2019 due to plant shutdown 7 and ODCM revision.

Micro-R per Hour 6.5 6

5.5 5

4.5 4

Retrieval Date DR-4 Northfield, MA DR-5 Spofford Lake VY 2022 AREOR Page 58 of 78

BVY 23-013 / Enclosure / Page 59 of 78

7. Quality Assurance Program 7.1 Environmental Dosimetry Company Laboratory ENVIRONMENTAL DOSIMETRY COMPANY ANNUAL QUALITY ASSURANCE STATUS REPORT January - December 2022 Environmental Dosimetry Company 10 Ashton Lane Sterling, MA 01564 VY 2022 AREOR Page 59 of 78

BVY 23-013 / Enclosure / Page 60 of 78 TABLE OF CONTENTS Page LIST OF TABLES ....................................................................................................................... iii EXECUTIVE

SUMMARY

............................................................................................................ iv Vermont Yankee Nuclear Power Station ................................................................................ 1 Year 2022 ............................................................................................................................... 1

1. INTRODUCTION ....................................................................................................... 4

2. BACKGROUND RADIOACTIVITY ........................................................................ 5

3. GENERAL PLANT AND SITE INFORMATION..................................................... 6

4. PROGRAM DESIGN .................................................................................................. 7 Table 4.1 Radiological Environmental Monitoring Program ............................................... 11 Table 4.1 cont. ...................................................................................................................... 12 Table 4.2 Radiological Environmental Monitoring Locations (Non-TLD) In2022 ............. 13 Table 4.3 Radiological Environmental Monitoring Locations (TLD) In 2022..................... 14 Table 4.4 Environmental Lower Limit Of Detection (LLD) SensitivityRequirements ....... 15 Table 4.5 Reporting Levels for Radioactivity Concentrations inEnvironmental Samples... 16

5. RADIOLOGICAL DATA

SUMMARY

TABLES ................................................... 23 Table 6.2 Trend Graph Summary Table ............................................................................... 46

8. LAND USE CENSUS ............................................................................................... 75 Table 8.1 2022 Land Use Census Locations*....................................................................... 76

9.

SUMMARY

............................................................................................................... 77

10. REFERENCES ...................................................................................................... 78 LIST OF TABLES Page

1. Percentage of Individual Analyses Which Passed EDC Internal Criteria, January - December 2022 5

2. Mean Dosimeter Analyses (n=6), January - December 2022 5

3. Summary of Independent QC Results for 2022 5 VY 2022 AREOR iii Page 60 of 78

BVY 23-013 / Enclosure / Page 61 of 78 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 was performed in 2022.There were no findings.

VY 2022 AREOR iv Page 61 of 78

BVY I.23-013 / Enclosure / Page 62 of 78 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.

II. 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:

(Hi Hi ) 100 Hi where:

Hi = 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)

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BVY 23-013 / Enclosure / Page 63 of 78

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:

(Hi Hi ) 1 100 Hi n where:

Hi = 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 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:

(

Hi H

) 100 H

where:

Hi = the reported exposure for the ith dosimeter (i.e., the reported exposure) 1 H = the mean reported exposure; i.e., H = Hi n

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.

VY 2022 AREOR 2 of 6 Page 63 of 78

BVY 23-013 / Enclosure / Page 64 of 78 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.

4. 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.

5. 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%.

III. DATA

SUMMARY

FOR ISSUANCE PERIOD JANUARY-DECEMBER 2022 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 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.

VY 2022 AREOR 3 of 6 Page 64 of 78

BVY 23-013 / Enclosure / Page 65 of 78 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 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.

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 2022. There were no findings identified.

2. External None.

VI. PROCEDURES AND MANUALS REVISED DURING JANUARY - DECEMBER 2022 Two procedures were reissued with no changes as part of the 5 year review cycle.

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, 2022.

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

VY 2022 AREOR 4 of 6 Page 65 of 78

BVY 23-013 / Enclosure / Page 66 of 78 TABLE 1 PERCENTAGE OF INDIVIDUAL DOSIMETERS THAT PASSED EDC INTERNAL CRITERIA JANUARY - DECEMBER 2022(1), (2)

Number % Passed Precision Dosimeter Type % Passed Bias Criteria Tested 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 2022(1), (2)

Standard Tolerance Process Date Exposure Level Mean Bias %

Deviation % Limit +/-15%

4/25/2022 43 1.2 1.8 Pass 4/27/2022 62 6.2 1.0 Pass 5/05/2022 99 2.3 0.7 Pass 7/26/2022 34 -2.6 1.2 Pass 7/27/2022 81 0.6 1.7 Pass 8/07/2022 107 -3.5 0.7 Pass 10/27/2022 52 1.8 0.9 Pass 11/02/2022 76 2.0 0.9 Pass 11/07/2022 27 7.0 0.7 Pass 01/24/2023 38 1.5 1.7 Pass 01/26/2023 115 -0.3 2.0 Pass 02/14/2023 49 2.3 4.0 Pass (1)This table summarizes results of tests conducted by EDC for TLDs issued in 2022.

(2)Environmental dosimeter results are free in air.

TABLE 3

SUMMARY

OF INDEPENDENT DOSIMETER TESTING JANUARY - DECEMBER 2022(1), (2)

Mean Standard Issuance Period Client Deviation % Pass / Fail Bias %

1st Qtr. 2022 Millstone -0.6 0.6 Pass 2nd Qtr.2022 Millstone -3.9 1.0 Pass 3rd Qtr. 2022 Millstone 0.1 0.5 Pass 4th Qtr.2022 Millstone -2.6 1.2 Pass 4th Qtr.2022 PSEG(PNNL) 48mR 1.1 1.5 Pass 4th Qtr.2022 PSEG(PNNL) 95mR 0.7 0.3 Pass 4th Qtr.2022 PSEG(PNNL) 143mR 2.3 0.8 Pass 4th Qtr.2022 PSEG(PNNL) 190mR 1.4 0.8 Pass 4th Qtr.2022 SONGS -5.6 1.1 Pass (1)Performance criteria are +/- 15%.

(2)Blind spike irradiations using Cs-137 VY 2022 AREOR 5 of 6 Page 66 of 78

BVY 23-013 / Enclosure / Page 67 of 78 APPENDIX A DOSIMETRY QUALITY CONTROL TRENDING GRAPHS ISSUE PERIOD JANAURY - DECEMBER 2022 VY 2022 AREOR 6 of 6 Page 67 of 78

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BVY 23-013 / Enclosure / Page 69 of 78 VY 2022 AREOR Page 69 of 78

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BVY 23-013 / Enclosure / Page 71 of 78 VY 2022 AREOR Page 71 of 78

BVY 23-013 / Enclosure / Page 72 of 78 7.2 Teledyne Brown Engineering Laboratory - Environmental Services (TBE-ES) 7.2.1 Operational Quality Control Scope 7.2.1.1 Inter-laboratory The Teledyne Brown Engineering Environmental Services Laboratory Quality Control (QC) Program is designed to monitor the quality of analytical processing associated with environmental, effluent (10 CFR 50),

bioassay, industrial process, and waste characterization (10 CFR 61) samples.

Quality Control of radioanalyses involves the internal process control program, and independent third party programs administered by Analytics and Environmental Resource Associates (ERA).

TBE-ES also participates in the Department of Energys (DOE) Mixed Analyte Performance Evaluation Program (MAPEP) administered by the U. S. Department of Energy. The MAPEP is a set of performance evaluation samples (e.g., water, soil, vegetation, etc.) designed to evaluate the ability and quality of analytical facilities performing measurement on samples that contain hazardous and radioactive (mixed) analytes.

Quality Control for radioanalyses during this reporting period consisted of internal process check samples.

Results for third-party process check prepared by Analytics, ERA and the DOEs MAPEP are not reported during the first quarter of the year due to the receipt date from the vendors.

7.2.1.2 Intra-laboratory The internal QC program is designed to include QC functions such as instrumentation checks (to ensure proper instrument response), blank samples (to which no analyte radioactivity has been added), for contamination checks, and instrumentation backgrounds. Process controls (or process checks) are either actual samples submitted in duplicate (duplicates) in order to evaluate the precision of laboratory measurements. Blank samples which have been spiked (spikes) with a known quantity of a radioisotope that is of interest to laboratory clients measure the accuracy of analyses. QC samples are intended to evaluate the entire radiochemical and radiometric process. Process control and qualification analyses samples seek to mimic the media type of those samples submitted for analysis by the various laboratory clients. The magnitude of the process control program combines both internal and external sources targeted at 10% of the routine sample analysis load.

To provide direction and consistency in administering the quality assurance program, TBE-ES has developed and follows a Quality Manual and a set of Standard Operating Procedures (SOP). The plan describes the scheduled frequency and scope of Quality Assurance and Quality Control (QA/QC) considered necessary for an adequate QA/QC program conducted throughout the year.

7.2.1.3 QA Program (Internal and External Audits)

During each reporting period at least one internal assessment is conducted in accordance with the pre-established TBE-ES Quality Control and Audit Assessment Schedule. In addition, the laboratory may be audited by prospective customers during a pre-contract audit, and/or by existing clients who wish to conduct periodic audits in accordance with their contractual arrangements. The Nuclear Utilities Procurement Issues Committee (NUPIC) conducts audits of TBE-ES as a function of a Utilities Radiological Environment Measurement Program (REMP).

TBE-ES Laboratory-Knoxville successfully completed client on-site audits including the Nuclear Utility Procurement Issues Committee (NUPIC). In 2022, the initial audit and approval for accreditation was granted for ISO-17025:2017 DoD-ELAP and DOECAP radiological analyses by Perry Johnson Laboratory Accreditation (PJLA). Each audit included a comprehensive review of TBE-ES's Quality and Technical programs and assessed the laboratory's ability to produce accurate and defensible data. No significant VY 2022 AREOR Page 72 of 78

BVY 23-013 / Enclosure / Page 73 of 78 deficiencies which would adversely impact data quality were identified during any of these audits.

Administrative findings identified during these inspections are usually addressed promptly, according to client specifications.

7.2.2 Analytical Services Quality Control Synopsis 7.2.2.1 Results Summary 7.2.2.1.1 Environmental Services Quality Control During this annual reporting period, twenty-seven nuclides associated with six media types were analyzed by means of the laboratory's internal process control, Analytics, ERA, MAPEP and DOE quality control programs. Media types representative of client company analyses performed during this reporting period were selected. The results for these programs are presented in Tables 7.2. Below is a synopsis of the media types evaluated:

Air Filter

Charcoal (Air Iodine)

Milk

Soil

Vegetation

Water 7.2.2.1.2 Analytics Environmental Cross-Check Program Twelve nuclides in milk, air particulate, air iodine (charcoal), and soil samples were evaluated for two sets of cross-checks during 2022. All environmental analyses performed were within the acceptable/acceptable with warning criteria except for one air particulate Ce-141 and one air particulate Co-60.

The Analytics March 2022 AP Ce-141 result was evaluated as Not Acceptable. The reported value for Ce-141 was 60.9 pCi and the known result was 42.0 pCi/L (1.45 ratio of reported result vs. known; TBEs internal acceptance range is 0.70 - 1.30). This sample was used as the workgroup duplicate with a result of 45.7 (109% of known) and was also counted on a different detector with a result of 50.9 (121% of known). This was TBEs first failure for AP Ce-141. (NCR 22-04)

The Analytics AP Co-60 result was evaluated as Not Acceptable. The reported value was 207 pCi and the known was 147 (141% of the known). TBEs internal QC acceptance is 70 - 130%. All QA was reviewed with no anomalies. This sample was used as the workgroup duplicate and counted on a different detector with a result of 167 pCi (114% of the known). This is the first failure for AP Co average result ratio compared to the known is 109%. (NCR 22-21) 7.2.2.1.3 Summary of Participation in the Department of Energy (DOE) Monitoring Program Fourteen nuclides in water, air particulate, soil, urine, and vegetation samples were evaluated twice in 2022.

All other environmental analyses that were reported were within the acceptable/acceptable with warning criteria except for urine U-234 & U-238 and water Tc-99.

The MAPEP February 2022 Urine U-234 & U-238 results were evaluated as Not Acceptable. TBEs reported values of 0.142 and 0.0254 were above the known upper ranges of 0.0096 and 0.0134 respectively for U-234 and U-238. These spiked values were below TBEs typical MDC for urine client samples. The samples were re-prepped using a larger sample aliquot and counted for 60 hours6.944444e-4 days 0.0167 hours 9.920635e-5 weeks 2.283e-5 months as opposed to 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months . The recount results were 0.00732 for U-234 and 0.0119 for U-238 (both within acceptable range). MAPEP urine samples VY 2022 AREOR Page 73 of 78

BVY 23-013 / Enclosure / Page 74 of 78 will be flagged to use a larger sample aliquot and counting time than typical client samples. MAPEP did not include any urine cross-check samples in August. (NCR 22-05)

The MAPEP August 2022 water Tc-99 result was evaluated as Not Acceptable. The reported value was 1.86

+/- 0.414 Bq/L for this false positive test. The evaluation of the submitted result to the 3 times the uncertainty indicated a slight positive. This sample was used as the workgroup duplicate with a result of 0.88

+/- 0.374 Bq/L. All QC was reviewed, and no anomalies found. This is the first unacceptable since the resumption of reporting water Tc-99 for the 3rd quarter of 2020. TBE to known ratios have ranged from 94-109% during this time. (NCR 22-22) 7.2.2.1.4 Summary of participation in the ERA Program Eighteen nuclides were evaluated in water, air particulate, and soil samples twice during 2022. All other analyses performed were within the acceptable criteria except for the MRAD 3rd quarter AP Pu-238 and RAD 4th quarter water U Natural.

The ERA MRAD September 2022 AP Pu-238 was evaluated as Not Acceptable. The reported value was 38.8 pCi and the known result was 29.9 (acceptance range 22.6 - 36.7). The AP filter was cut in half prior to digestion (shared with Fe-55) but should have been complete digested together and aliquoted afterwards like typical client samples. This is the first failure for AP Pu-238. (NCR 22-19)

The ERA October 2022 water Uranium result was evaluated as Not Acceptable. The reported value was 10.54 pCi/L and the known was 8.53 (acceptance range 6.60 - 9.88) or 124% of the known (acceptable for TBE QC). The 2-sigma error was 3.2, placing the reported result well within the acceptable range. This sample was used as the workgroup duplicate with a result of 8.2 +/- 2.9 pCi/L (also within the acceptable range). All other QA was reviewed with no anomalies. (NCR 22-20) 7.2.2.2 Intra-Laboratory Process Control Program The TBE-ES Laboratory's internal process control program evaluated 7,251 individual samples.

7.2.2.2.1 Spikes/Matrix Spikes During this reporting period, all 1,564 workgroup and matrix spikes analyzed were within the acceptance criteria.

7.2.2.2.2 Analytical Blanks During this reporting period, 1597/1599 environmental blanks analyzed were less than the MDC. One QC blank was slightly above the MDC for Sr-90 and S-35. The workgroups included samples whose activity was greater than 5x the blank. Positive blank activities were reported with a case narrative 7.2.2.2.3 Duplicates Total All the 4088 duplicate sets analyzed were within acceptance criteria.

7.2.2.2.4 Non-Conformance Reports There were 22 non-conformance reports issued for this reporting period. No VY data was impacted by the non-conformance in each of these cases.

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8. LAND USE CENSUS The Vermont Yankee Nuclear Power Station Off-site Dose Calculation Manual 3/4.5.2 requires that a Land Use Census be conducted annually between the dates of June 1 and October 1.

The 2022 Land Use Census was completed on September 27, 2022. The requirement to identify the location of the nearest milk animal in each meteorological sector from the land use census was eliminated from the ODCM in December of 2016. This was eliminated because the primary isotope, I-131 had decayed away. 41 Since no additional farms have started up within five kilometers of the plant, nor have any of the nearest residences changed locations since the 2008 Land Use Census, we are using the census analysis results from that period.

No locations were identified in the census that had at least a 20% greater dose commitment than the values currently being calculated in accordance with ODCM Control 4.3.3. This assessment included a review of dispersion factors for all of the identified residence locations. Therefore, no change in the critical receptors assumed in the ODCM dose calculations needs to be identified in the Annual Radiological Effluent Release Report.

The 2008 Land Use Census Analysis ranked the farms according to the calculated critical organ dose. The two highest ranked farms within five kilometers of the plant (per requirement of ODCM Table 3.5.1) were Blodgett Farm and Miller Farm. These farms were part of the milk sampling program until the cessation of milk sampling in December 2016 due to the decay of radioiodines since plant shut down. No additional farms are available within a five kilometer radius of the plant. We are not required to, nor are we able to add any additional farm (or farms) to the program at this time.

The results of the 2022 Land Use Census are included in this report in compliance with ODCM 4.5.2 and ODCM 10.2. The locations identified during the census may be found in Table 8.1.

VY 2022 AREOR Page 75 of 78

BVY 23-013 / Enclosure / Page 76 of 78 Table 8.1 2022 Land Use Census Locations*

NEAREST RESIDENCE NEAREST MILK ANIMAL SECTOR km (mi) km (mi)

N 1.4 (0.9) ----

NNE 1.4 (0.9) 5.52 (3.42) Cows NE 1.3 (0.8) ----

ENE 1.0 (0.6) ----

E 0.9 (0.6) ----

ESE 1.9 (1.2) ----

SE 2.0 (1.2) 6.67 (4.4) Cows SSE 2.1 (1.3) ----

S 0.6 (0.4) 3.6 (2.23) Cows**

SSW 0.8 (0.5) ----

SW 0.4 (0.3) ----

WSW 0.5 (0.3) 9.73 (6.03) Cows W 0.6 (0.4) 0.82 (0.5) Cows WNW 1.1 (0.7) ----

NW 2.3 (1.4) ----

NNW 1.7 (1.1) ----

Sectors and distances are relative to the plant stack as determined by a Global Positioning System survey conducted in 1997.

- Location of nearest milk animal within 3 miles of the plant to the point of predicted highest annual average D/Q value in each of the three major meteorological sectors.

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9.

SUMMARY

During 2022, as in previous years during plant operation, a program was conducted to assess the levels of radiation or radioactivity in the Vermont Yankee Nuclear Power Station environment.

Samples were collected (including TLDs) over the course of the year, with radionuclide or exposure rate analyses performed. The samples included groundwater, river water, sediment, fish, silage, mixed grass, storm drain sediment, and storm drain water. In addition to these samples, the air surrounding the plant was sampled continuously and the radiation levels were measured continuously with environmental TLDs.

Three of the objectives of the Radiological Environmental Monitoring Program (REMP) are:

To provide an early indication of the appearance or accumulation of any radioactive material in the environment caused by the operation of the station.

To provide assurance to regulatory agencies and the public that the stations environmental impact is known and within anticipated limits.

To verify the adequacy and proper functioning of station effluent controls and monitoring systems.

Low levels of radioactivity from three sources (discussed below) were detected in samples collected off-site as a part of the radiological environmental monitoring program. Most samples had measurable levels of naturally-occurring Potassium-40, Beryllium-7, Thorium-232 or radon daughter products. These are the most common of the naturally-occurring radionuclides.

Samples of sediment contained fallout radioactivity such as Cesium-137 from atmospheric nuclear weapons tests conducted primarily from the late 1950s through 1980.

Tritium (Hydrogen-3), at concentrations higher than background levels, was detected in on-site groundwater monitoring wells installed in 2007 and in 2010 in response to industry events and the discovery of primary system leakage from underground Augmented Off Gas (AOG) System condensate return piping into the subsurface groundwater pool under the plant site. The leakage from this piping was terminated in early February 2010. Extensive sampling and analysis was performed on groundwater samples and other media throughout all of year 2022 Steps to remediate the contamination of the subsurface groundwater layer under the plant site were terminated in December 2014. Additional assessment of the dose contribution of radioactive waterborne releases from this event is provided in the 2022 Annual Radioactive Effluent Release Report.

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10. REFERENCES

1. USNRC Radiological Assessment Branch Technical Position, An Acceptable Radiological Environmental Monitoring Program, Revision 1, November 1979.

2. NCRP Report No. 94, Exposure of the Population in the United States and Canada from Natural Background Radiation, National Council on Radiation Protection and Measurements, 1987.

3. Ionizing Radiation: Sources and Biological Effects, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), 1982 Report to the General Assembly.

4. Kathren, Ronald L., Radioactivity and the Environment - Sources, Distribution, and Surveillance, Harwood Academic Publishers, New York, 1984.

5. Till, John E. and Robert H. Meyer, ed., Radiological Assessment - A Textbook on Environmental Dose Analysis, NUREG/CR-3332, U.S. Nuclear Regulatory Commission, Washington, D.C., 1983.

6. NUREG/CR-3130, Influence of Leach Rate and Other Parameters on Groundwater Migration, February 1983.

7. Vermont Yankee Offsite Dose Calculation Manual (ODCM), Revision 42, February 17, 2022.

VY 2022 AREOR Page 78 of 78

BVY 23-013, 2022 Radiological Environmental Operating Report

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