BVY 22-015, 2021 Radiological Environmental Operating Report
| ML22125A148 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee  |
| Issue date: | 05/05/2022 |
| From: | Daniels C NorthStar Nuclear Decommissioning Company |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BVY 22-015 | |
| Download: ML22125A148 (84) | |
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Northstar Nuclear Decommissioning Co., LLC Vermont Yankee Nuclear Power Station NorthStar 320 Governor Hunt Rd.
mon, VT 05354 802-451-5354 Corey R. Daniels ISFSI Senior Manager 10 CFR 50, Appx I, SEC IV.8.2 and IV.8.3 BVY 22-015 May 5, 2022 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
2021 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 2021 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,
Enclosure:
Annual Radiological Environmental Operating Report for 2021 .
BVY 22-015 / Page 2 of 2 cc: Mr. David C. Lew 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 Jim Montgomery, Commissioner Massachusetts Department of Conservation and Recreation 251 Causeway Street Boston, MA 02114
BVY 22-015 Docket No.50-271 Enclosure Vermont Yankee Nuclear Power Station Annual Radiological Environmental Operating Report for 2021 (81 pages excluding this cover sheet)
BVY 22-015 / Enclosure / Page 1 of 81 NORTHSTAR-VERMONT YANKEE Vermont Yankee Nuclear Power Station ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT Year 2021 Reviewed by:_ ~~~ ~~-~--~--~--~ _ _ _ _ _ _ _ _ _ __ _ / S", z.Z.C? z_z:_
Scott Dorval, RP Maµa'gi!r ISFSI Date Approved for Distribution:~'---+--Plcr.~~ft...-=---
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BVY 22-015 / Enclosure / Page 2 of 81 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 ............................................................. 7
- 4. PROGRAM DESIGN .......................................................................................................... 7 4.1 Monitoring Zones ............................................................................................................. 8 4.2 Pathways Monitored ......................................................................................................... 9 4.3 Descriptions of Monitoring Programs .............................................................................. 9 4.3.1 Air Sampling ............................................................................................................................. 9 4.3.2 Charcoal Cartridge (Radioiodine) Sampling ........................................................................... 10 4.3.3 River Water Sampling ............................................................................................................. 10 4.3.4 Ground Water (Deep Well Potable Water) Sampling ............................................................. 11 4.3.5 Sediment Sampling ................................................................................................................. 11 4.3.6 Milk Sampling......................................................................................................................... 11 4.3.7 Silage (Chopped Corn or Grass) Sampling ............................................................................. 11 4.3.8 Mixed Grass Sampling ............................................................................................................ 11 4.3.9 Fish Sampling ......................................................................................................................... 11 4.3.10 TLD Monitoring.................................................................................................................. 12
- 5. RADIOLOGICAL DATA
SUMMARY
TABLES ........................................................... 25
- 6. ANALYSIS OF ENVIRONMENTAL RESULTS ............................................................ 40 6.1 Sampling Program Deviations ....................................................................................... 40
- 7. Quality Assurance Program ............................................................................................... 60 7.1 Environmental Dosimetry Company Laboratory ........................................................... 60 7.2 Teledyne Brown Engineering Laboratory - Environmental Services (TBE-ES) .......... 74 7.2.1 Operational Quality Control Scope ......................................................................................... 74 7.2.2 Analytical Services Quality Control Synopsis ........................................................................ 75
- 8. LAND USE CENSUS........................................................................................................ 78
- 9.
SUMMARY
....................................................................................................................... 80
- 10. REFERENCES .................................................................................................................. 81 VY 2021 AREOR Page 2 of 81
BVY 22-015 / Enclosure / Page 3 of 81 LIST OF TABLES Table 4.1 Radiological Environmental Monitoring Program ....................................................... 13 Table 4.2 Radiological Environmental Monitoring Locations (Non-TLD) In 2021 .................... 15 Table 4.3 Radiological Environmental Monitoring Locations (TLD) In 2021 ............................ 16 Table 4.4 Environmental Lower Limit Of Detection (LLD) Sensitivity Requirements ............... 17 Table 4.5 Reporting Levels for Radioactivity Concentrations in Environmental Samples .......... 18 Table 5.1 Sample Medium Analyses ............................................................................................ 27 Table 5.2 Environmental TLD Data Summary ............................................................................. 38 Table 5.3 Environmental TLD Measurements 2021..................................................................... 39 Table 6.1 Removed........................................................................................................................ 45 Table 6.2 Trend Graph Summary Table ....................................................................................... 47 Table 8.1 2021 Land Use Census Locations* ............................................................................... 81 LIST OF FIGURES Figure 4.1 Environmental Sampling Locations in Close Proximity to the Plant .......................... 19 Figure 4.2 Environmental Sampling Locations Within 5 km of the Plant.................................... 20 Figure 4.3 Environmental Sampling Locations Greater Than 5 km from the Plant ..................... 21 Figure 4.4 TLD Locations in Close Proximity to the Plant .......................................................... 22 Figure 4.5 TLD Locations within 5 km of the Plant ..................................................................... 23 Figure 4.6 TLD Locations Greater Than 5 km of the Plant .......................................................... 24 Figure 6.1 Gross Beta Measurements on Air Particulate Filters Quarterly Average Concentrations .............................................................................................................................. 48 Figure 6.2 Gross Beta Measurements on Air Particulate Filters (11) ........................................... 49 Figure 6.3 Gross Beta Measurements on Air Particulate Filters (12) ........................................... 50 Figure 6.8 Gross Beta Measurements on River Water Semi-Annual Concentrations .................. 51 Figure 6.9 Gross Beta Measurements on Ground Water Semi-Annual Concentrations ............... 52 Figure 6.12 Cesium 137 in Fish - Annual Average Concentrations ............................................. 53 Figure 6.13 Average Exposure Rate at Inner Ring, Outer Ring and Control TLDs ..................... 54 Figure 6.14 Exposure Rate at Indicator TLDs DR-1 and DR-2.................................................... 55 Figure 6.15 Exposure Rate at Indicator TLD DR-6 ...................................................................... 56 Figure 6.16 Exposure Rate at Site Boundary TLDs DR-7, DR-8 and DR-53A ........................... 57 Figure 6.17 Exposure Rate at Site Boundary TLDs DR-43, DR-45 and DR-46 .......................... 58 Figure 6.27 Exposure Rate at Control TLD DR-5 ........................................................................ 59 VY 2021 AREOR Page 3 of 81
BVY 22-015 / Enclosure / Page 4 of 81
- 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 NuclearPower Station (VYNPS) in Vernon, Vermont during the calendar year 2021. 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 (VYNPS) Off-Site Dose Calculation Manual (ODCM) requirements for REMP sampling, tables listing all locations sampled or monitored in 2021 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 VYNPS 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 2021 environmental TLD measurements.
Section 6: Provides the results of the 2021 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 2021 Land Use Census.
BVY 22-015 / Enclosure / Page 5 of 81 Section 9: Gives a summary of the 2021 Radiological Environmental Monitoring Program.
- 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).
BVY 22-015 / Enclosure / Page 6 of 81 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).
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 VY 2021 AREOR Page 6 of 81
BVY 22-015 / Enclosure / Page 7 of 81 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.
A decision was made in 2013 to permanently shut down and decommission Vermont Yankee Nuclear Power Station at the end of 2014. The last day of power operation occurred on December 29, 2014.
- 4. PROGRAM DESIGN The Radiological Environmental Monitoring Program (REMP) for the Vermont Yankee Nuclear Power Station (VYNPS) 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.
BVY 22-015 / Enclosure / Page 8 of 81 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. VYNPS maintained a contract with Normandeau Associates to collect all fish and river sediment samples. In 2021, 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 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.
BVY 22-015 / Enclosure / Page 9 of 81 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 2021 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 2021 AREOR Page 9 of 81
BVY 22-015 / Enclosure / Page 10 of 81 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 <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. 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 VYNPS.
4.3.3 River Water Sampling An automatic compositing sampler was maintained at the downstream sampling location. This sampler has been nonfunctional throughout 2021. The ODCM compensatory action for the out of service composite sampler was to obtain daily grab samples that were combined together to create a representative monthly composite sample. This has been accomplished by the Vermont Yankee Radiation Protection/Chemistry Department staff. An additional grab sample is collected monthly at the upstream control location. Each sample is analyzed for gamma-emitting radionuclides.
Although not required by the VYNPS 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. In July of 2021, Revision 41 of the Vermont Yankee Off-Site Dose Calculation Manual was issued. This revision eliminated the requirement for the automatic composite sampler at the downstream location and replaced it with a monthly grab sample.
BVY 22-015 / Enclosure / Page 11 of 81 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 VYNPS ODCM. Each sample is analyzed for gamma-emitting radionuclides and H-3. Although not required by the VYNPS 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.
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 2021. The samples are frozen VY 2021 AREOR Page 11 of 81
BVY 22-015 / Enclosure / Page 12 of 81 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 2021 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.
BVY 22-015 / Enclosure / Page 13 of 81 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 Sampling Collection Analysis Analysis Sample Mode Frequency 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
- 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.
BVY 22-015 / Enclosure / Page 14 of 81 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.
BVY 22-015 / Enclosure / Page 15 of 81 Table 4.2 Radiological Environmental Monitoring Locations (Non-TLD) In 2021 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
- 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
- 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).
BVY 22-015 / Enclosure / Page 16 of 81 Table 4.3 Radiological Environmental Monitoring Locations (TLD) In 2021 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 for direct radiation monitors VY 2021 AREOR Page 16 of 81
BVY 22-015 / Enclosure / Page 17 of 81 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.
BVY 22-015 / Enclosure / Page 18 of 81 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 30,000 pCi/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.
BVY 22-015 / Enclosure / Page 19 of 81 Figure 4.1 Environmental Sampling Locations in Close Proximity to the Plant VY 2021 AREOR Page 19 of 81
BVY 22-015 / Enclosure / Page 20 of 81 Figure 4.2 Environmental Sampling Locations Within 5 km of the Plant VY 2021 AREOR Page 20 of 81
BVY 22-015 / Enclosure / Page 21 of 81 Figure 4.3 Environmental Sampling Locations Greater Than 5 km from the Plant VY 2021 AREOR Page 21 of 81
BVY 22-015 / Enclosure / Page 22 of 81 Figure 4.4 TLD Locations in Close Proximity to the Plant VY 2021 AREOR Page 22 of 81
BVY 22-015 / Enclosure / Page 23 of 81 Figure 4.5 TLD Locations within 5 km of the Plant VY 2021 AREOR Page 23 of 81
BVY 22-015 / Enclosure / Page 24 of 81 Figure 4.6 TLD Locations Greater Than 5 km of the Plant VY 2021 AREOR Page 24 of 81
BVY 22-015 / Enclosure / Page 25 of 81
- 5. RADIOLOGICAL DATA
SUMMARY
TABLES This section summarizes the analytical results of the environmental samples that were collected during 2021. 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 2021, 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 2021 and the number of measurements which exceeded the Reporting Levels found in Table 3.5.2 of the VYNPS 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 2021 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 2021 AREOR Page 25 of 81
BVY 22-015 / Enclosure / Page 26 of 81 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.
BVY 22-015 / Enclosure / Page 27 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS AIR PARTICULATES GR-B 36 0.01 0.0136 0.0133 0.0138 12 INDICATOR 0 (PCI/M3) (24/24) (12/12) (12/12) N. HINSDALE NH
( 0.0103/ 0.0182) ( 0.0097/ 0.0168) ( 0.0115/ 0.0169) 3.6 KM NNW OF SITE GAMMA 12 BE-7 N/A 0.1121 0.1183 0.1183 21 CONTROL 0 (8/8) (4/4) (4/4) SPOFFORD LAKE (9)
( 0.0793/ 0.1290) ( 0.0945/ 0.1307) ( 0.0945/ 0.1307) 16.4 KM NNE OF SITE K-40 N/A 0.0342 0.0364 0.0394 11 INDICATOR 0 (0/8) (0/4) (0/4) RIVER STA. NO. 3.3
(< 0.0189/< 0.0488) (< 0.0261/< 0.0518) (< 0.0255/< 0.0488) 1.9 KM SSE OF SITE CS-134 0.05 0.0020 0.0020 0.0023 11 INDICATOR 0 (0/8) (0/4) (0/4) RIVER STA. NO. 3.3
(< 0.0015/< 0.0024) (< 0.0015/< 0.0030) (< 0.0021/< 0.0024) 1.9 KM SSE OF SITE CS-137 0.06 0.0019 0.0018 0.0020 11 INDICATOR 0 (0/8) (0/4) (0/4) RIVER STA. NO. 3.3
(< 0.0013/< 0.0026) (< 0.0013/< 0.0028) (< 0.0016/< 0.0026) 1.9 KM SSE OF SITE RA-226 N/A 0.0327 0.0338 0.0368 11 INDICATOR 0 (0/8) (0/4) (0/4) RIVER STA. NO. 3.3
(< 0.0239/< 0.0418) (< 0.0279/< 0.0495) (< 0.0329/< 0.0418) 1.9 KM SSE OF SITE AC-228 N/A 0.0075 0.0085 0.0085 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)
(< 0.0051/< 0.0106) (< 0.0057/< 0.0134) (< 0.0057/< 0.0134) 16.4 KM NNE OF SITE TH-228 N/A 0.0029 0.0032 0.0032 21 CONTROL 0 (0/8) (0/4) (0/4) SPOFFORD LAKE (9)
(< 0.0021/< 0.0036) (< 0.0026/< 0.0043) (< 0.0026/< 0.0043) 16.4 KM NNE OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 27 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 28 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS RIVER WATER GR-B 23 4 1.782 1.844 1.844 21 CONTROL 0 (PCI/LITER) (3/11) (2/12) (2/12) ROUTE 9 BRIDGE
(< 1.180/ 2.320) (< 1.360/ 2.140) (< 1.360/ 2.140) 11.8 KM NNW OF SITE H-3 23 2000 488 487 488 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(<322/<570) (<324/<587) (<322/<570) 1.9 KM SSE OF SITE GAMMA 23 MN-54 15 2.021 1.894 2.021 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 1.060/< 5.463) (< 1.060/< 3.900) (< 1.060/< 5.463) 1.9 KM SSE OF SITE CO-58 N/A 2.015 1.937 2.015 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 1.163/< 4.457) (< 1.162/< 3.784) (< 1.163/< 4.457) 1.9 KM SSE OF SITE FE-59 N/A 4.423 4.140 4.423 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 2.650/< 8.457) (< 2.067/< 8.183) (< 2.650/< 8.457) 1.9 KM SSE OF SITE CO-60 15 2.141 2.029 2.141 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 1.076/< 5.685) (< 1.114/< 3.147) (< 1.076/< 5.685) 1.9 KM SSE OF SITE ZN-65 30 4.134 4.081 4.134 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 2.126/< 9.574) (< 2.203/< 8.946) (< 2.126/< 9.574) 1.9 KM SSE OF SITE ZR-95 15 3.483 3.443 3.483 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 2.238/< 6.111) (< 2.051/< 7.235) (< 2.238/< 6.111) 1.9 KM SSE OF SITE I-131 N/A 5.982 3.170 5.982 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 2.239/<11.49) (< 1.735/< 5.822) (< 2.239/<11.49) 1.9 KM SSE OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 28 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 29 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS RIVER WATER (cont'd) CS-134 15 1.873 1.859 1.873 11 INDICATOR 0 (PCI/LITER) (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 0.965/< 4.866) (< 1.078/< 3.784) (< 0.965/< 4.866) 1.9 KM SSE OF SITE CS-137 18 2.054 2.077 2.077 21 CONTROL 0 (0/11) (0/12) (0/12) ROUTE 9 BRIDGE
(< 1.066/< 5.435) (< 1.127/< 4.070) (< 1.127/< 4.070) 11.8 KM NNW OF SITE BA/LA-140 N/A 4.455 3.255 4.455 11 INDICATOR 0 (0/11) (0/12) (0/11) RIVER STA. NO. 3.3
(< 2.557/< 8.063) (< 1.704/< 7.177) (< 2.557/< 8.063) 1.9 KM SSE OF SITE RA-226 N/A 45.592 47.35 47.35 21 CONTROL 0 (0/11) (0/12) (0/12) ROUTE 9 BRIDGE
(<23.04/<118.2) (<23.79/<93.92) (<23.79/<93.92) 11.8 KM NNW OF SITE GROUND WATER GR-B 12 4 3.050 2.145 3.513 11 INDICATOR 0 (PCI/LITER) (7/8) (2/4) (4/4) MAIN PLANT WELL
(< 1.300/ 4.580) (< 1.390/ 3.250) ( 2.580/ 4.580) 0.2 KM ON SITE H-3 12 2000 524 522 539 12 INDICATOR 0 (0/8) (0/4) (0/4) VERNON GREEN WELL
(<430/<608) (<487/<553) (<489/<608) 2.1 KM SSE OF SITE GAMMA 12 MN-54 15 1.939 1.961 1.997 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 1.142/< 2.709) (< 1.822/< 2.169) (< 1.777/< 2.446) 0.2 KM ON SITE CO-58 N/A 1.931 1.984 1.993 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 0.998/< 2.705) (< 1.935/< 2.084) (< 1.781/< 2.455) 0.2 KM ON SITE FE-59 N/A 4.050 4.158 4.186 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 1.950/< 5.849) (< 3.752/< 4.471) (< 3.763/< 5.200) 0.2 KM ON SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 29 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 30 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS GROUND WATER (cont'd) CO-60 15 2.154 2.171 2.242 11 INDICATOR 0 (PCI/LITER) (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 1.144/< 3.321) (< 2.047/< 2.268) (< 1.821/< 2.567) 0.2 KM ON SITE ZN-65 30 3.938 4.036 4.036 22 CONTROL 0 (0/8) (0/4) (0/4) COPELAND WELL
(< 2.023/< 5.838) (< 3.514/< 4.510) (< 3.514/< 4.510) 13.7 KM N OF SITE ZR-95 15 3.457 3.437 3.542 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 1.769/< 4.888) (< 3.226/< 3.644) (< 3.137/< 4.586) 0.2 KM ON SITE CS-134 15 1.905 1.947 1.947 22 CONTROL 0 (0/8) (0/4) (0/4) COPELAND WELL
(< 1.137/< 2.589) (< 1.775/< 2.081) (< 1.775/< 2.081) 13.7 KM N OF SITE CS-137 18 2.068 2.061 2.150 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 1.113/< 2.803) (< 1.904/< 2.136) (< 1.960/< 2.552) 0.2 KM ON SITE BA/LA-140 N/A 2.992 3.042 3.098 11 INDICATOR 0 (0/8) (0/4) (0/4) MAIN PLANT WELL
(< 1.350/< 4.211) (< 2.617/< 3.347) (< 2.735/< 3.377) 0.2 KM ON SITE RA-226 N/A 56.785 51.34 62.598 11 INDICATOR 0 (1/8) (0/4) (1/4) MAIN PLANT WELL
(<33.94/81.92) (<49.57/<54.56) (<44.55/81.92) 0.2 KM ON SITE SEDIMENT GAMMA 36 (PCI/KG DRY) BE-7 N/A 770.09 928.33 1287.6 17 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL T-1
(<370.5/<1863) (<669/<1134) (<712.2/<1863) 0.1 KM E OF SITE K-40 N/A 17930.47 17482.33 22300 22 CONTROL 0 (30/30) (6/6) (2/2) N. STOR DRAIN OUTFALL U-1 (6964/21740) (9924/23340) (21260/23340) 0.1 KM E OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 30 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 31 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS SEDIMENT (cont'd) MN-54 N/A 52.08 61.71 72.48 17 INDICATOR 0 (PCI/KG DRY) (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL T-1
(<30.82/<85.05) (<36.81/<88.72) (<64.15/<80.8) 0.1 KM E OF SITE CO-60 N/A 45.49 59.46 71.69 22 CONTROL 0 (0/30) (0/6) (0/2) N. STOR DRAIN OUTFALL U-1
(<23.55/<72.36) (<30.89/<96.66) (<46.72/<96.66) 0.1 KM E OF SITE ZN-65 N/A 116.18 135.78 163.35 17 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL T-1
(<63.29/<212.7) (<76.26/<188.7) (<114/<212.7) 0.1 KM E OF SITE NB-95 N/A 89.07 106.81 143.36 17 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL T-1
(<49.22/<207) (<72.78/<132.6) (<79.71/<207) 0.1 KM E OF SITE CS-134 150 43.28 52.47 59.21 35 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL W-4
(<24.84/<70.67) (<29.46/<70.21) (<55.21/<63.21) 0.1 KM E OF SITE CS-137 180 81.61 77.31 103.61 22 CONTROL 0 (17/30) (3/6) (2/2) N. STOR DRAIN OUTFALL U-1
(<29.5/136.7) (<35.6/111.7) (95.52/111.7) 0.1 KM E OF SITE BA/LA-140 N/A 2086.08 2001.22 6417.35 17 INDICATOR 0 (0/30) (0/6) (0/2) N. STORM DRAIN OUTFALL T-1
(<312.5/<12430) (<563.9/<4928) (<404.7/<12430) 0.1 KM E OF SITE RA-226 N/A 2229.58 2494.83 3190.5 19 INDICATOR 0 (24/30) (5/6) (2/2) N. STORM DRAIN OUTFALL T-3 (788.6/3548) (<1063/3575) (2848/3533) 0.1 KM E OF SITE AC-228 N/A 2207.63 2193.6 3807.5 11 INDICATOR 0 (27/30) (5/6) (2/2) DISCHARGE (3-4)
(<256/4055) (<502.3/4317) (3560/4055) 0.1 KM E OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 31 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 32 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS SEDIMENT (cont'd) TH-228 N/A 1296.38 1272.67 1696.5 22 CONTROL 0 (PCI/KG DRY) (30/30) (6/6) (2/2) N. STOR DRAIN OUTFALL U-1 (532.7/1639) (599/1765) (1628/1765) 0.1 KM E OF SITE TH-232 N/A 1164.81 1198 1472 22 CONTROL 0 (30/30) (6/6) (2/2) N. STOR DRAIN OUTFALL U-1 (569.1/1462) (736.5/1530) (1414/1530) 0.1 KM E OF SITE U-238 N/A 5048.63 5980.33 6996 22 CONTROL 0 (0/30) (0/6) (0/2) N. STOR DRAIN OUTFALL U-1
(<2806/<8078) (<2844/<9049) (<4943/<9049) 0.1 KM E OF SITE TEST WELLS GR-B 16 4 4.2 N/A 7.0 16 INDICATOR 0 (PCI/LITER) (13/16) (4/4) S.FIELD WELL 202 (Septage Spreading Field) (< 1.4/ 8.0) ( 5.5/ 8.0) ON SITE H-3 16 2000 565 N/A 574.3 17 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 203
(<498/<624) (<515/<616) ON SITE GAMMA 16 K-40 N/A 24.6 N/A 27.5 17 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 203
(<11.4/<40.6) (<18/<35.1) ON SITE MN-54 15 1.7 N/A 1.9 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.1/< 2.1) (< 1.6/< 2.0) ON SITE CO-58 N/A 1.8 N/A 1.9 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.1/< 2.1) (< 1.6/< 2.1) ON SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 32 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 33 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS TEST WELLS (cont'd) FE-59 N/A 3.7 N/A 3.9 18 INDICATOR 0 (PCI/LITER) (0/16) (0/4) S.FIELD WELL 204 (Septage Spreading Field) (< 2.3/< 4.2) (< 3.4/< 4.1) ON SITE CO-60 15 1.9 N/A 1.9 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.3/< 2.4) (< 1.6/< 2.2) ON SITE NB-95 N/A 1.9 N/A 2.0 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.2/< 2.3) (< 1.7/< 2.3) ON SITE I-131 N/A 3.0 N/A 3.2 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 2.0/< 4.1) (< 2.5/< 3.7) ON SITE CS-134 15 1.7 N/A 1.8 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.2/< 2.0) (< 1.6/< 2.0) ON SITE CS-137 18 1.8 N/A 2.0 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.2/< 2.2) (< 1.6/< 2.2) ON SITE BA/LA-140 N/A 2.9 N/A 3.1 18 INDICATOR 0 (0/16) (0/4) S.FIELD WELL 204
(< 1.7/< 3.5) (< 2.6/< 3.3) ON SITE SILAGE GAMMA 12 0 (PCI/KG WET) BE-7 N/A 295.43 475.6 475.6 22 CONTROL (1/8) (2/4) (2/4) FRANKLIN FARM
(<76.86/1300) (<163.8/1096) (<163.8/1096) 9.7 K WSW OF SITE 0
K-40 N/A 4234.3 11457.75 11457.75 22 CONTROL (8/8) (4/4) (4/4) FRANKLIN FARM (472.9/9127) (8261/14380) (8261/14380) 9.7 K WSW OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 33 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 34 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS SILAGE (cont'd) CS-134 60 15.69 22.86 22.86 22 CONTROL 0 (PCI/KG WET) (0/8) (0/4) (0/4) FRANKLIN FARM
(< 9.17/<23.06) (<17.16/<28.53) (<17.16/<28.53) 9.7 K WSW OF SITE CS-137 60 15.97 78.09 78.09 22 CONTROL 0 (0/8) (3/4) (3/4) FRANKLIN FARM
(< 9.14/<25.75) (<24.72/134.4) (<24.72/134.4) 9.7 K WSW OF SITE AC-228 N/A 70.98 99.66 99.66 22 CONTROL 0 (0/8) (0/4) (0/4) FRANKLIN FARM
(<33.89/<111.2) (<67.18/<134.6) (<67.18/<134.6) 9.7 K WSW OF SITE TH-228 N/A 29.72 41.3 41.3 22 CONTROL 0 (0/8) (0/4) (0/4) FRANKLIN FARM
(<18.84/<43.65) (<26.02/<62.35) (<26.02/<62.35) 9.7 K WSW OF SITE MIXED GRASS GAMMA 6 (PCI/KG WET) BE-7 N/A 1291.25 1080.25 1923.45 11 INDICATOR 0 (3/4) (2/2) (2/2) RIVER STA. NO. 3.3
(<222.1/3571) (237.5/1923) (275.9/3571) 1.9 KM SSE OF SITE K-40 N/A 4959.25 5138.5 5307 11 INDICATOR 0 (4/4) (2/2) (2/2) RIVER STA. NO. 3.3 (3487/6466) (4620/5657) (4148/6466) 1.9 KM SSE OF SITE I-131 N/A 31.46 29.55 33.2 12 INDICATOR 0 (0/4) (0/2) (0/2) N. HINSDALE NH
(<23.11/<38.5) (<17.55/<41.55) (<27.89/<38.5) 3.6 KM NNW OF SITE CS-134 60 22.24 19.46 22.46 12 INDICATOR 0 (0/4) (0/2) (0/2) N. HINSDALE NH
(<20.62/<24.3) (<12.24/<26.68) (<20.62/<24.3) 3.6 KM NNW OF SITE CS-137 60 26.24 21.22 27.63 11 INDICATOR 0 (0/4) (0/2) (0/2) RIVER STA. NO. 3.3
(<21.96/<31.5) (<12.57/<29.87) (<23.76/<31.5) 1.9 KM SSE OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 34 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 35 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS MIXED GRASS (cont'd) RA-226 N/A 542.15 484 550.65 11 INDICATOR 0 (PCI/KG WET) (0/4) (0/2) (0/2) RIVER STA. NO. 3.3
(<479.5/<601.2) (<234.4/<733.6) (<500.1/<601.2) 1.9 KM SSE OF SITE AC-228 N/A 91.92 85.12 96.39 12 INDICATOR 0 (0/4) (0/2) (0/2) N. HINSDALE NH
(<84.94/<105.6) (<56.74/<113.5) (<87.17/<105.6) 3.6 KM NNW OF SITE TH-228 N/A 45.39 40.48 49.99 11 INDICATOR 0 (0/4) (0/2) (0/2) RIVER STA. NO. 3.3
(<36.39/<52.77) (<26.78/<54.17) (<47.21/<52.77) 1.9 KM SSE OF SITE FISH GAMMA 8 (PCI/KG WET) K-40 N/A 2970 2727 2970 11 INDICATOR 0 (4/4) (4/4) (4/4) VERNON POND (2204/3764) (2054/3313) (2204/3764) 0.6 KM SSE OF SITE MN-54 130 20.598 21.413 21.413 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<19.8/<21.11) (<16.45/<26.69) (<16.45/<26.69) 11.8 KM NNW OF SITE CO-58 N/A 30.92 32.863 32.863 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<26.54/<37.35) (<22.82/<38.07) (<22.82/<38.07) 11.8 KM NNW OF SITE FE-59 N/A 97.51 99.515 99.515 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<71.49/<124.5) (<58.96/<121.4) (<58.96/<121.4) 11.8 KM NNW OF SITE CO-60 130 20.083 20.88 20.88 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<19.07/<21.07) (<17.5/<28.06) (<17.5/<28.06) 11.8 KM NNW OF SITE ZN-65 260 44.488 50.073 50.073 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<39.44/<47.26) (<39.02/<59.84) (<39.02/<59.84) 11.8 KM NNW OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 35 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 36 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS FISH (cont'd) CS-134 130 18.535 20.375 20.375 21 CONTROL 0 (PCI/KG WET) (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<17.12/<20.09) (<15.63/<27.5) (<15.63/<27.5) 11.8 KM NNW OF SITE CS-137 150 19.408 20.93 20.93 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<17.84/<21.92) (<17.19/<29.85) (<17.19/<29.85) 11.8 KM NNW OF SITE H-3 4 0.2 159 66 159 11 INDICATOR 0 (0/2) (0/2) (0/2) VERNON POND
(<113/<205) (<57/<74) (<113/<205) 0.6 KM SSE OF SITE AM-241 8 N/A 1.136 1.694 1.694 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(< 0.441/< 1.882) (< 0.400/< 3.079) (< 0.400/< 3.079) 11.8 KM NNW OF SITE CM-242 8 N/A 0.633 0.620 0.633 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND
(< 0.171/< 1.309) (< 0.150/< 0.963) (< 0.171/< 1.309) 0.6 KM SSE OF SITE CM-243/244 8 N/A 1.317 1.627 1.627 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(< 1.154/< 1.423) (< 0.231/< 3.086) (< 0.231/< 3.086) 11.8 KM NNW OF SITE FE-55 8 N/A 702.5 894.875 894.875 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(<143.4/<1727) (<293.1/<1915) (<293.1/<1915) 11.8 KM NNW OF SITE NI-63 8 N/A 217.75 198 217.75 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND
(<183/<268) (<150/<244) (<183/<268) 0.6 KM SSE OF SITE PU-238 8 N/A 2.298 2.439 2.439 21 CONTROL 0 (0/4) (0/4) (0/4) ROUTE 9 BRIDGE
(< 0.633/< 3.529) (< 0.836/< 3.903) (< 0.836/< 3.903) 11.8 KM NNW OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 36 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 37 of 81 TABLE 5.1 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM ANNUAL
SUMMARY
FOR THE VERMONT YANKEE NUCLEAR POWER PLANT, 2021 MEDIUM OR TYPES OF NUMBER OF REQUIRED MEAN MEAN MEAN STATION # NUMBER OF PATHWAY SAMPLED ANALYSES ANALYSES LOWER LIMIT (F) (F) (F) NAME NONROUTINE (UNIT OF PERFORMED PERFORMED OF DETECTION RANGE RANGE RANGE DISTANCE AND REPORTED MEASUREMENT) (LLD) DIRECTION MEASUREMENTS FISH (cont'd) PU-239/240 8 N/A 4.126 3.266 4.126 11 INDICATOR 0 (PCI/KG WET) (0/4) (0/4) (0/4) VERNON POND
(< 2.099/< 5.144) (< 1.447/< 4.451) (< 2.099/< 5.144) 0.6 KM SSE OF SITE PU-241 8 N/A 613.5 488.75 613.5 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND
(<402/<728) (<293/<700) (<402/<728) 0.6 KM SSE OF SITE PU-242 8 N/A 4.037 3.517 4.037 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND
(< 2.009/< 6.067) (< 1.566/< 4.982) (< 2.009/< 6.067) 0.6 KM SSE OF SITE SR-89 8 N/A 865 838.25 865 11 INDICATOR 0 (0/4) (0/4) (0/4) VERNON POND
(<157/<1560) (<134/<1750) (<157/<1560) 0.6 KM SSE OF SITE SR-90 8 60 53.325 76.15 76.15 21 CONTROL 0 (1/4) (2/4) (2/4) ROUTE 9 BRIDGE
(<43.2/71) (<44.9/134) (<44.9/134) 11.8 KM NNW OF SITE DIRECT RADIATION TLD-QUARTERLY 36 N/A 7.0 7.0 9.4 DR45 INDICATOR 0 (MILLI-ROENTGEN/QTR.) (32/32) (4/4) (4/4) SITE BOUNDARY (6/10) (6/7) ( 8.8/ 9.9) 0.12 KM NE OF SITE FRACTION OF DETECTABLE MEASUREMENTS AT SPECIFIED LOCATIONS IS INDICATED IN PARENTHESES (F) Page 37 of 81 VY 2021 AREOR
BVY 22-015 / Enclosure / Page 38 of 81 TABLE 5.2 ENVIRONMENTAL TLD DATA
SUMMARY
VERMONT YANKEE NUCLEAR POWER STATION, VERNON, VT (JANUARY - DECEMBER 2021)
OFFSITE STATION INNER RING TLD OUTER RING TLD WITH HIGHEST MEAN CONTROL TLDs MEAN* MEAN* STA.NO./ MEAN* MEAN*
RANGE* RANGE* RANGE* RANGE*
(N0. MEASUREMENTS)** (N0. MEASUREMENTS)** (N0. MEASUREMENTS)** (N0. MEASUREMENTS)**
6.30 +/- 0.27 6.99 +/- 0.23 DR02 6.99 +/- 0.30 6.74 +/- 0.26 5.51 to 7.19 6.60 to 7.27 6.60 to 7.27 6.25 to 7.00 8 4 4 4 SITE BOUNDARY TLD WITH HIGHEST MEAN SITE BOUNDARY TLD STA.NO./ MEAN* MEAN*
RANGE* RANGE *
(NO. MEASUREMENTS)** (NO. MEASUREMENTS)**
DR45 9.44 +/- 0.34 7.29 +/- 0.30 8.83 to 9.90 6.19 to 9.90 4 24
- Units are in micro-R per hour.
- Each "measurement" is typically based on quarterly readings from five TLD elements.
BVY 22-015 / Enclosure / Page 39 of 81 TABLE 5.3 ENVIRONMENTAL TLD MEASUREMENTS 2021 (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 5.51 +/- 0.24 5.73 +/- 0.25 5.98 +/- 0.46 6.19 +/- 0.22 5.9 DR-02 N Hinsdale, NH 6.60 +/- 0.24 7.00 +/- 0.20 7.27 +/- 0.29 7.10 +/- 0.21 7.0 DR-05 Spofford Lake, NH 6.29 +/- 0.31 6.78 +/- 0.20 7.00 +/- 0.28 6.87 +/- 0.26 6.7 DR-06 Vernon School 6.22 +/- 0.28 6.59 +/- 0.22 6.97 +/- 0.24 7.19 +/- 0.24 6.7 DR-07 Site Boundary 6.19 +/- 0.35 6.59 +/- 0.29 7.19 +/- 0.29 7.10 +/- 0.34 6.8 DR-08 Site Boundary 6.44 +/- 0.43 6.62 +/- 0.23 6.67 +/- 0.34 7.05 +/- 0.32 6.7 DR-43 Site Boundary 6.20 +/- 0.25 6.78 +/- 0.28 6.81 +/- 0.30 7.11 +/- 0.33 6.7 DR-45 Site Boundary 9.65 +/- 0.31 9.37 +/- 0.23 8.83 +/- 0.37 9.90 +/- 0.43 9.4 DR-46 Site Boundary 6.62 +/- 0.30 6.62 +/- 0.20 6.96 +/- 0.23 7.42 +/- 0.21 6.9 DR-53A West Cornfield 6.86 +/- 0.27 7.10 +/- 0.31 7.36 +/- 0.37 7.47 +/- 0.29 7.2 VY 2021 AREOR Page 39 of 81
BVY 22-015 / Enclosure / Page 40 of 81
- 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 2021, five 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 2021 were:
a) 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 short by one hour due to entry into Daylight Savings Time (DST) on 3/30/2021 (Week 13-21) Documented in Condition Report 2021-0145.
b) Environmental Air Sampling Station # 21 (AP-21, located in Spofford, New Hampshire) air pump was found to be out of service on 05/25/2021 (Week 21-21). The loss of power for approximately 3.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> was due to thunderstorms. Documented in Condition Report 2021-0145.
c) Environmental Air Sampling Stations # 11 and # 21 (AP-11, located at River Station No. 3.3 and AP-21, located in Spofford, New Hampshire) air pumps were found to be out of service on 06/29/2021 (Week 26-21). The loss of power for approximately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> was due to thunderstorms. Documented in Condition Report 2021-0145.
d) 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 11/30/2021 (Week 48-21) Documented in Condition Report 2021-0145.
e) Environmental Silage Sampling Stations # 11, 12, and 21 (TG-11, located at River Station No. 3.3, TG-12, located in N. Hinsdale, NH, and TG-21, located in Spofford Lake) did not have sufficient forgeable vegetation to harvest in the 4th Qtr. 2021. Documented in Condition Report 2021-0145.
f) Air sample station outages during 2021 are reflected in the air sample collection time percentages listed below.
AP/CF # 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 11 100.0% 100.0% 100.0% 100.1%
12 99.9% 99.9% 99.9% 100.1%
21 99.9% 99.8% 99.9% 100.0%
BVY 22-015 / Enclosure / Page 41 of 81 6.2 Comparison of Achieved LLDs with Requirements Table 4.5.1 of the VYNPS 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 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 VYNPS 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 2021, 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 2021, 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 2021.
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 radioiodine following shutdown.
BVY 22-015 / Enclosure / Page 42 of 81 6.5 Data Analysis by Media Type The 2021 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 during this reporting period. Be-7, a naturally-occurring cosmogenic radionuclide, was detected on all 12 filter sets analyzed.
BVY 22-015 / Enclosure / Page 43 of 81 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)
Daily grab samples were collected from the Connecticut River downstream of the plant discharge area and hydro station, location WR-11 until June of 2021. These samples were combined to create a representative composite sample. Monthly grab samples were collected at the upstream control location all year on the Connecticut River,location WR-21. The downstream location became a monthly grab sample in July 2021.
The composited samples at WR-11 were collected monthly and sent along with the WR- 21 grab samples to the contracted environmental laboratory for analysis. Table 5.1 shows that gross-beta measurements were positive in three out of 11 indicator samples as would be expected due to naturally-occurring radionuclides in the water. Gross-beta was detected in two 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 2021.
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 VYNPS ODCM) and one control location during 2021. 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 seven of 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. Naturally-occurring Radium-226 (Ra-226) was detected in one of eight indicator samples and none of the control samples. No other gamma-emitting radionuclides or tritium were detected in any of the samples.
6.5.2.3 Sediment (SE)
Semi-annual river sediment grab samples were collected from two indicator locations during 2021.
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 2021, 15 locations were sampled at SE-12 during each of VY 2021 AREOR Page 43 of 81
BVY 22-015 / Enclosure / Page 44 of 81 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 29 of 36 samples.
Actinium-228 (Ac-228) was detected in 32 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 20 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 VYNPS site where septic sludge is spread. This sampling continued through 2021. The test wells are summarized in Table 5.1 under the media category, Test Well (WT). In 2021, four wells were sampled 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 13 of 16 samples collected with levels ranging from <1.4 to 8.0 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 VYNPS 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 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 2021 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 VY 2021 AREOR Page 44 of 81
BVY 22-015 / Enclosure / Page 45 of 81 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). Because of revisions in the security arrangements at the plant site, there was no water available for collection in Manholes 11H, 13 and 8 during2021. 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. As a result of this leak a large pool of subsurface water became contaminated with Tritium. A large number of new groundwater sample wells were installed and a significant effort was mounted to find and fix the leak. 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 2021 Annual Radioactive Effluent Release Report.
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 2021.
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 2021. Each of these was analyzed for gamma-emitting radionuclide. As expected with all biological media, naturally-occurring Be-7 was detected in three of 12 samples and K-40 was detected in all samples. Cs-137 was detected in three 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 two of the four quarters of 2021. As expected with all biological media, naturally-occurring Be-7 was detected in five of the six samples collected. Naturally-occurring K-40 was detected in all six samples.
BVY 22-015 / Enclosure / Page 46 of 81 6.5.3.4 Fish (FH)
Semiannual samples of fish were collected from two locations in both spring and fall of 2021 for the VY REMP. Several species may be collected such as Walleye, Small Mouth Bass, Large Mouth Bass, Yellow Perch, White Perch, and Rock Bass. 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 tenth 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-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 2021. 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.
BVY 22-015 / Enclosure / Page 47 of 81 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.
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 2021 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.
BVY 22-015 / Enclosure / Page 48 of 81 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 2021 AREOR Page 48 of 81
BVY 22-015 / Enclosure / Page 49 of 81 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 2021 Week Number AP-11 River Station No. 3.3 AP-21 Spofford Lake VY 2021 AREOR Page 49 of 81
BVY 22-015 / Enclosure / Page 50 of 81 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 2021 Week Number AP-12 N. Hinsdale NH AP-21 Spofford Lake VY 2021 AREOR Page 50 of 81
BVY 22-015 / Enclosure / Page 51 of 81 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 2021 AREOR Page 51 of 81
BVY 22-015 / Enclosure / Page 52 of 81 Figure 6.9 - Gross Beta Measurements on Ground Water Semi-Annual Average Concentrations 11.0 10.0 9.0 8.0 7.0 pCi/Liter 6.0 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 2021 AREOR Page 52 of 81
BVY 22-015 / Enclosure / Page 53 of 81 Figure 6.12 - Cesium 137 in Fish - Annual Average Concentrations 80.0 70.0 60.0 50.0 pCi/kg 40.0 30.0 20.0 10.0 0.0 Year Note: In 2005 switched to reporting < MDA when no activity was detected. Using MDA values result in a larger number.
FH-11 Vernon Pond FH-21 Rt. 9 Bridge (Control)
BVY 22-015 / Enclosure / Page 54 of 81 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 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Retrieval Date Control Inner Ring Outer Ring VY 2021 AREOR Page 54 of 81
BVY 22-015 / Enclosure / Page 55 of 81 Figure 6.14 - Exposure Rate at Indicator TLDs, DR1-3 10.0 9.5 9.0 TLD sampling from locations DR-3 8.5 was discontinued in 2019 due to plant shutdown and ODCM revision.
8.0 Micro-R per hour 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Retrieval Date DR-1 River Sta. No. 3.3 DR-2 N. Hinsdale, NH DR-3 Hinsdale Substation VY 2021 AREOR Page 55 of 81
BVY 22-015 / Enclosure / Page 56 of 81 Figure 6.15 - Exposure Rate at Indicator TLDs, DR-6 & DR-50 10.0 9.5 9.0 8.5 TLD sampling from locations DR-50 was discontinued in 2019 due to plant shutdown and ODCM revision.
8.0 Micro-R per hour 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Retrieval Date DR-6 Vernon School DR-50 Gov. Hunt House VY 2021 AREOR Page 56 of 81
BVY 22-015 / Enclosure / Page 57 of 81 Figure 6.16 - Exposure Rate at Site Boundary TLDs DR-7, DR-8 and DR-53A 11 10 9
Micro-R per Hour 8
7 6
5 4
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Retrieval Date DR-7 Site Boundary (C) DR-8 Site Boundary DR-53A Site Boundary VY 2021 AREOR Page 57 of 81
BVY 22-015 / Enclosure / Page 58 of 81 Figure 6.17 - Exposure Rate at Site Boundary TLDs - DR-43 thru 46 19 18 TLD sampling from locations DR-44 17 was discontinued in 2019 due to plant shutdown and ODCM revision.
16 15 14 13 Micro-R per hour 12 11 10 9
8 7
6 5
4 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Retrieval Date DR-43 Site Boundary DR-44 Site Boundary DR-45 Site Boundary DR-46 Site Boundary VY 2021 AREOR Page 58 of 81
BVY 22-015 / Enclosure / Page 59 of 81 Figure 6.27 - Exposure Rate at Control TLDs DR-4 & 5 9
8.5 8
TLD sampling from locations DR-4 was discontinued in 2019 due to plant shutdown and ODCM revision.
7.5 7
Micro-R per Hour 6.5 6
5.5 5
4.5 4
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 Retrieval Date DR-4 Northfield, MA DR-5 Spofford Lake VY 2021 AREOR Page 59 of 81
BVY 22-015 / Enclosure / Page 60 of 81
- 7. Quality Assurance Program 7.1 Environmental Dosimetry Company Laboratory VY 2021 AREOR Page 60 of 81
BVY 22-015 / Enclosure / Page 61 of 81 TABLE OF CONTENTS Page LIST OF TABLES ......................................................................................................................62 EXECUTIVE
SUMMARY
...........................................................................................................63 Vermont Yankee Nuclear Power Station ................................................................................ 1 Year 2021 ............................................................................................................................... 1
- 1. INTRODUCTION ....................................................................................................... 4
- 2. BACKGROUND RADIOACTIVITY ........................................................................ 5
- 3. GENERAL PLANT AND SITE INFORMATION..................................................... 7
- 4. PROGRAM DESIGN .................................................................................................. 7 Table 4.1 Radiological Environmental Monitoring Program ............................................... 13 Table 4.1 cont. ...................................................................................................................... 14 Table 4.2 Radiological Environmental Monitoring Locations (Non-TLD) In2021 ............. 15 Table 4.3 Radiological Environmental Monitoring Locations (TLD) In 2021..................... 16 Table 4.4 Environmental Lower Limit Of Detection (LLD) SensitivityRequirements ....... 17 Table 4.5 Reporting Levels for Radioactivity Concentrations inEnvironmental Samples... 18
- 5. RADIOLOGICAL DATA
SUMMARY
TABLES ................................................... 25
- 6. ANALYSIS OF ENVIRONMENTAL RESULTS ................................................... 40 Table 6.2 Trend Graph Summary Table ............................................................................... 47
- 8. LAND USE CENSUS ............................................................................................... 78 Table 8.1 2021 Land Use Census Locations* ....................................................................... 79
- 9.
SUMMARY
............................................................................................................... 80
- 10. REFERENCES ...................................................................................................... 81 VY 2021 AREOR Page 61 of 81
BVY 22-015 / Enclosure / Page 62 of 81 LIST OF TABLES Page
- 1. Percentage of Individual Analyses Which Passed EDC Internal Criteria, January - December 2021 5
- 2. Mean Dosimeter Analyses (n=6), January - December 2021 5
BVY 22-015 / Enclosure / Page 63 of 81 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 2021.There were no findings.
BVY 22-015 / Enclosure / Page 64 of 81 I. INTRODUCTION The TLD systems at the Environmental Dosimetry Company (EDC) are calibrated and operated to ensure consistent and accurate evaluation of TLDs. The quality of the dosimetric results reported to EDC clients is ensured by in-house performance testing and independent performance testing by EDC clients, and both internal and client directed program assessments.
The purpose of the dosimetry quality assurance program is to provide performance documentation of the routine processing of EDC dosimeters. Performance testing provides a statistical measure of the bias and precision of dosimetry processing against a reliable standard, which in turn points out any trends or performance changes. Two programs are used:
A. QC Program Dosimetry quality control tests are performed on EDC Panasonic 814 Environmental dosimeters. These tests include: (1) the in-house testing program coordinated by the EDC QA Officer and (2) independent test perform by EDC clients. In-house test are performed using six pairs of 814 dosimeters, a pair is reported as an individual result and six pairs are reported as the mean result.Results of these tests are described in this report.
Excluded from this report are instrumentation checks. Although instrumentation checks represent an important aspect of the quality assurance program, they are not included as process checks in this report. Instrumentation checks represent between 5-10% of the TLDs processed.
B. QA Program An internal assessment of dosimetry activities is conducted annually by the Quality Assurance Officer (Reference 1). The purpose of the assessment is to review procedures, results, materials or components to identify opportunities to improve or enhance processes and/or services.
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)
BVY 22-015 / Enclosure / Page 65 of 81
- 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.
BVY 22-015 / Enclosure / Page 66 of 81 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 2021 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.
BVY 22-015 / Enclosure / Page 67 of 81 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 2021. There were no findings identified.
- 2. External None.
VI. PROCEDURES AND MANUALS REVISED DURING JANUARY - DECEMBER 2021 Several 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, 2021.
- 2. EDC Manual 1, Quality System Manual, Rev. 4, September 28, 2020.
BVY 22-015 / Enclosure / Page 68 of 81 TABLE 1 PERCENTAGE OF INDIVIDUAL DOSIMETERS THAT PASSED EDC INTERNAL CRITERIA JANUARY - DECEMBER 2021(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 2021(1), (2)
Standard Tolerance Process Date Exposure Level Mean Bias %
Deviation % Limit +/-15%
5/04/2021 33 0.6 0.9 Pass 5/06/2021 120 -0.2 1.4 Pass 5/26/2021 53 -3.8 1.6 Pass 7/27/2021 67 2.8 1.4 Pass 8/04/2021 91 -1.8 2.3 Pass 9/14/2021 47 -0.2 2.3 Pass 11/01/2021 28 3.7 0.6 Pass 11/03/2021 74 1.9 1.9 Pass 11/09/2021 103 1.1 1.1 Pass 01/26/2022 37 2.6 1.9 Pass 01/30/2022 85 -4.2 1.1 Pass 02/06/2022 58 2.9 1.2 Pass (1)This table summarizes results of tests conducted by EDC for TLDs issued in 2021.
(2)Environmental dosimeter results are free in air.
TABLE 3
SUMMARY
OF INDEPENDENT DOSIMETER TESTING JANUARY - DECEMBER 2021(1), (2)
Mean Standard Issuance Period Client Deviation % Pass / Fail Bias %
1st Qtr. 2021 SONGS -3.8 1.4 Pass 1st Qtr. 2021 SONGS -4.7 1.1 Pass 2nd Qtr.2021 Seabrook 3.1 1.0 Pass 3rd Qtr. 2021 Millstone -4.7 1.4 Pass 4th Qtr.2021 PSEG(PNNL) 50mR 1.3 0.8 Pass 4th Qtr.2021 PSEG(PNNL) 100mR 1.8 0.8 Pass 4th Qtr.2021 PSEG(PNNL) 150mR -0.6 0.5 Pass 4th Qtr.2021 PSEG(PNNL) 200mR -2.6 2.0 Pass 4th Qtr.2021 Seabrook 2.6 1.4 Pass (1)Performance criteria are +/- 15%.
(2)Blind spikeirradiations using Cs-137 VY 2021 AREOR Page 68 of 81
BVY 22-015 / Enclosure / Page 69 of 81 APPENDIX A DOSIMETRY QUALITY CONTROL TRENDING GRAPHS ISSUE PERIOD JANUARY - DECEMBER 2021 VY 2021 AREOR Page 69 of 81
BVY 22-015 / Enclosure / Page 70 of 81 VY 2021 AREOR Page 70 of 81
BVY 22-015 / Enclosure / Page 71 of 81 VY 2021 AREOR Page 71 of 81
BVY 22-015 / Enclosure / Page 72 of 81 VY 2021 AREOR Page 72 of 81
BVY 22-015 / Enclosure / Page 73 of 81 VY 2021 AREOR Page 73 of 81
BVY 22-015 / Enclosure / Page 74 of 81 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 (10CFR Part 50), bioassay, industrial process, and waste characterization (10CFR Part 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, air filters, 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 available at this time due to receipt date from the vendors and are not reported during the first quarter of the year.
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)
BVY 22-015 / Enclosure / Page 75 of 81 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 has successfully completed the, State of Tennessee, Nuclear Utility Procurement Issues Committee (NUPIC), New York State and Department of Healths Environmental Laboratory Approval Program (NELAP) audits. These audits were each a comprehensive review of TBE-ES's Quality and Technical programs used to assess the laboratory's ability to produce accurate and defensible data. No significant 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 2021. All environmental analyses performed were within the acceptable/acceptable with warning criteria.
7.2.2.1.3 Summary of Participation in the Department of Energy (DOE) Monitoring Program VY 2021 AREOR Page 75 of 81
BVY 22-015 / Enclosure / Page 76 of 81 Fourteen nuclides in water, air particulate, soil, urine, and vegetation samples were evaluated twice in 2021. All other environmental analyses that were reported were within the acceptable/acceptable with warning criteria except for one AP Gross Alpha and two soil Ni-63.
TBE also analyzed water and soil for Tc-99 for information purposes (not on required list for REMP) and one soil sample was evaluated as unacceptable.
The MAPEP February 2021 AP Gross Alpha result was evaluated as Not Acceptable. The reported value was 0.371 Bq/sample and the known result was 1.77 Bq/sample (acceptance range 0.53 - 3.01). A similar failure had occurred several years prior due to the filter being placed with the wrong side up on the detector. At that time, a small dot was placed on the top of the filter prior to removal from the package to indicate the correct side for counting.
The current sample was still in the detector when the result was received (dot side facing the detector). The sample was recounted with a similar result and was flipped and recounted.
The flipped result was 0.661 Bq/sample, within the acceptable range. Because TBE cannot rely on receiving correct packaging from the provider, MAPEP AP cross-checks will be counted on both sides going forward. NOTE: The August sample had the same packaging issue (upside down). (NCR 21-02)
The MAPEP February 2021 soil Ni-63 was evaluated as Not Acceptable. The reported value was 310 Bq/kg and the known result was 689 (acceptance range 482 - 896). All workgroup QC was reviewed with no anomalies. The analytical procedure had been revised prior to this analysis to eliminate added interferences. The sample yield was >100%, indicative of incomplete separation from interferences, leading to a lower result. The procedure was again revised after acceptable results were obtained. (NCR 21-03)
The MAPEP August 2021 soil Ni-63 result was evaluated as Not Acceptable. The reported value was 546 Bq/kg and the known result was 1,280 Bq/kg (acceptance range 896 - 1,664).
All QC was reviewed and no anomalies found. The procedure revision to remove added MAPAP interferences was ineffective for this sample. No client soil matrix samples were analyzed for Ni-63 in 2020 or 2021. The root cause investigation is still ongoing at this time. (NCR 21-13) 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 2021. All other analyses performed were within the acceptable criteria except for one water Fe-55, one Gross Beta, and one H-3.
The ERA MRAD March 2021 Water Fe-55 result was evaluated as Not Acceptable. The reported value for Fe-55 was 579 pCi/L and the known result was 275 pCi/L (acceptance range 162 - 400). When reviewing the original sample data, it was found that the carrier yield was 52.6% (lower than typical water samples). Looking at the etched plate that was counted, it appeared that some loss of sample could have occurred. The sample was logged for reanalysis and used as the workgroup duplicate. The results were acceptable at 197 and 221 respectively. Yields were 97.4% and 105.7% and the plated samples were centered with no apparent loss of sample. The loss of sample during plating resulted in a low yield which produced an artificially high sample result. (NCR 21-01)
BVY 22-015 / Enclosure / Page 77 of 81 The ERA October 2021 water Gross Beta result was evaluated as Not Acceptable. The reported value was 63.0 pCi/L and the known was 55.7 (acceptance range 38.1 - 62.6) or 113% of the known. The 2-sigma error was 6.8, placing the reported result well within the acceptable range. All QA was reviewed with no anomalies. A follow-up Quick Response cross-check was analyzed with a 120% ratio (see item 7). (NCR 21-10)
The ERA October 2021 water Tritium result was evaluated as Not Acceptable. The reported value was 13,800 pCi/L and the known was 17,200 (acceptance range 15,000 - 18,900). The 2-sigma error was 1,430, placing the result within the acceptable range. TBEs internal QC acceptance is 70% - 130%, while ERAs for this sample was 87% - 110%. All QA was reviewed with no anomalies. A Quick Response follow-up cross-check was analyzed with a result of 17,500 pCi/L (known 17,800 pCi/L). (NCR 21-11)
The ERA December 2021 Quick Response water Gross Beta result was evaluated as Not Acceptable. The reported value was 47.6 pCi/L and the known was 39.8 pCi/L or 120% of the known (acceptance range of 26.4 - 47.3). The 2-sigma error was 6.1, placing the reported result well within the acceptable range. All QA was reviewed with no anomalies. The original sample was recounted on a different detector with a result of 40.3 +/- 6.27 pCi/L. The failure of this sample and the RAD-127 was due to the narrow upper acceptance ranges assigned (119% and 112%) (NCR 21-14) 7.2.2.2 Intra-Laboratory Process Control Program The TBE-ES Laboratory's internal process control program evaluated 7,805 individual samples.
7.2.2.2.1 Spikes/Matrix Spikes During this reporting period, all 1435/1436 environmental spikes and matrix spikes analyzed were within the acceptance criteria. Samples in a single WG with a failing spike recovery were not reported but were completely re-prepped. The new workgroup QC was within acceptable range.
7.2.2.2.2 Analytical Blanks During this reporting period, 1474/1475 environmental blanks analyzed were less than the MDC. One QC blank was slightly above the MDC, and a case narrative was included with the sample results.
7.2.2.2.3 Duplicates Total All of the 4894 duplicate sets analyzed were within acceptance criteria.
7.2.2.2.4 Non-Conformance Reports There were 14 non-conformance reports issued for this reporting period. No ENNVY data was impacted by the non-conformance in each of these cases.
BVY 22-015 / Enclosure / Page 78 of 81
- 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 2021 Land Use Census was completed on September 29, 2021. 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. 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 2021 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.
BVY 22-015 / Enclosure / Page 79 of 81 Table 8.1 2021 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.
BVY 22-015 / Enclosure / Page 80 of 81
- 9.
SUMMARY
During 2020, 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.
Over 188 samples were collected (including TLDs) over the course of the year, with a total of over 394 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 2021 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 2021 Annual Radioactive Effluent ReleaseReport.
BVY 22-015 / Enclosure / Page 81 of 81
- 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 41, July 1, 2021.