ML19129A287

Submittal of Annual Radiological Environmental Operating Report

ML19129A287
Person / Time
Site:	Sequoyah
Issue date:	05/09/2019
From:	Rasmussen M Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation, NRC/RGN-II
References
Download: ML19129A287 (60)

Text

Tennessee Valley Authority, Sequoyah Nuclear Plant, P.O. Box 2000, Soddy Daisy, Tennessee 37384 May 9, 2019 10CFR50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D. C. 20555-0001 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327, 50-328,72-034

Subject:

Annual Radiological Environmental Operating Report Enclosed is the Annual Radiological Environmental Operating Report for the period of January 1 to December 31, 2018. This report is being submitted as required by the respective Sequoyah Nuclear Plant (SQN), Units 1 and 2, Technical Specification 5.6.1 and SQN's Offsite Dose Calculation Manual Administrative Control Section 5.1, each of which specifies that the report be submitted prior to May 15th of each year.

There are no regulatory commitments contained in this letter. If you have any questions concerning this matter, please contact Mr. Jonathon Johnson, SQN Licensing Manager, at (423)843-8129.

Respectfully, Matthew Rasmussen Site Vice President Sequoyah Nuclear Plant

Enclosure:

Annual Radiological Environmental Operating Report, Sequoyah Nuclear Plant, 2018 cc (Enclosure):

NRC Regional Administrator - Region II NRC Resident Inspector- Sequoyah Nuclear Plant printed on recycled paper

ENCLOSURE ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT SEQUOYAH NUCLEAR PLANT 2018

2018 Annual Radiologica Environnnental Operating Report Tennessee Valley Authority Sequoyah Nuclear Plant May 2019 Prepared under contract by Chesapeake Nuclear Services, Inc. and GEL Laboratories, LLC GEL Laboratories llc 1tbk Chesapeake Nuclear Services a member ofThe GEL Group n<

TABLE OF CONTENTS Executive Summary....-

• 1 Introduction 2 Naturally Occurring and Background Radioactivity 2 Electric Power Production 3 Site and Plant Description 5 Radiological Environmental Monitoring Program 7 Direct Radiation Monitoring 10 Measurement Techniques 10 Results 10 Atmospheric Monitoring 13 Sample Collection and Analysis 13 Results 13 Terrestrial Monitoring 15 Sample Collection and Analysis 15 Results 15 Liquid Pathway Monitoring 17 Sample Collection and Analysis 17 Results 17 Assessment and Evaluation 19 Results 19 Conclusions 19 References 20 Appendix A Radiological Environmental Monitoring Program and Sampling Locations 21 Appendix B Program Modifications 31 Appendix C Program Deviations 33 Appendix D Analytical Procedures 35 Appendix E Lower Limits Of Detection 37 Appendix F Quality Assurance/Quality Control Program 41 Appendix G Land Use Census 44 Appendix H Data Tables and Figures 46 Appendix I Errata to Previous Annual Environmental Operating Reports 55

EXECUTIVE

SUMMARY

This report describes the Radiological Environmental Monitoring Program (REMP) conducted by the Tennessee Valley Authority (TVA) near the Sequoyah Nuclear Plant (SQN) during the 2018 monitoring period. The program is conducted in accordance with regulatory requirements to monitor the environment per 10 CFR 20, 10 CFR 50, applicable NUREGs (U.S. NRC, 1991) and TVA procedures (TVA, 2018). The REMP includes the collection and subsequent determination of radioactive material content in environmental samples. Various types of samples are collected within the vicinity of the plant, including air, water, food crops, soil, fish and shoreline sediment, and direct radiation levels are measured. The radiation levels of these samples are measured and compared with results at control stations located outside the plant's vicinity and data collected at SQN priorto operations (preoperational data). This report contains an evaluation of the potential impact of SQN operations on the environment and the general public.

All environmental samples in support of the REMP were collected by TVA and contractor personnel. All environmental media were analyzed by GEL Laboratories, LLC except for environmental dosimeters which were analyzed by Landauer. The evaluation of all results and the generation of this report was performed by Chesapeake Nuclear Services, Inc. and GEL Laboratories.

Most of the radioactivity measured in environmental samples in the SQN program can be attributed to naturally occurring radioactive materials. There is no indication that SQN activities increased the background radiation levels normally observed in the areas surrounding the plant, as measured by environmental dosimeters. In 2018, trace quantities of cesium-137 (Cs-137) were measured in some soil samples from both indicator and control locations. Strontium-90 (Sr-90) was identified in one indicator location soil sample. The concentrations were typical of the levels expected to be present in the environment from past nuclear weapons testing. The fallout from accidents at the Chernobyl plant in the Ukraine in 1986 and the Fukushima plant in Japan in 2011 may have also contributed to the low levels of Cs-137 and Sr-90 measured in environmental samples. There was no identified increase in Cs-137 and Sr-90 levels attributed to Sequoyah.

Tritium (H-3) was detected in some surface water samples, but only from control locations. For public drinking water, low levels of gross beta and tritium radioactivity were identified in some samples from control locations and low levels of tritium were identified in some indicator location samples. The measured tritium levels were very low and a small fraction of the EPAdrinking water limit. Some control location ground water well samples were positive for gross beta, which can be attributed to natural radioactivity. Only naturally occurring radioactivity was identified in all milk, fish and food products samples. These levels of radioactive elements detected do not represent a significant contribution to the radiation exposure to members of the public.

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INTRODUCTION This report describes and summarizes the results of radioactivity measurements made near SQN and laboratory analyses of samples collected in the area. The measurements are made to comply with the requirements of 10 CFR 50, Appendix A, Criterion 64 and 10 CFR 50, Appendix I, Section IV.B.2, IV.B.3 and IV.C and to determine potential effects on public health and safety. This report satisfies the annual reporting requirements of SQN Technical Specification (TS) 5.6.1 and Offsite Dose Calculation Manual (ODCM) Administrative Control 5.1. In addition to reporting the data prescribed by specific requirements, other information is included to help correlate the significance of results measured by this monitoring program to the levels of environmental radiation resulting from naturally occurring radioactive materials.

Naturally Occurring and Background Radioactivity Most materials in our world today contain trace amounts of naturally occurring radioactivity. Potassium-40 (K-40), with a half-life of 1.3 billion years, is a common radioactive element found naturally in our environment. Approximately 0.01 percent of all potassium is radioactive potassium-40. Other examples of naturally occurring radioactivity are beryllium-7 (Be-7), bismuth-212 and 214 (Bi-212 and Bi-214), lead-210 and 214 (Pb-210 and Pb-214), thallium-208 (TI-208), actinium-228 (Ac-228), uranium-235 and uranium-238 (U-235 and U-238), thorium-234 (Th-234), radium-226 (Ra-226), radon-220 and radon-222 (Rn-220 and Rn-222), carbon-14 (C-14), and hydrogen-3 (H-3, commonly called tritium). These naturally occurring radioactive elements are in the soil, our food, our drinking water, and our bodies. Radiation emitted from these materials make up part of low-level natural background radiation exposures.

Radiation emitted from cosmic rays is the remainder.

It is possible to get an idea of the relative hazard of different types of radiation sources by evaluating the amount of radiation the U.S. population receives from each general type of radiation source. The information in Table 1 is primarily adapted from the U.S. Nuclear Regulatory Commission (U.S. NRC, February 1996) and National Council on Radiation Protection (NCRP, March 2009).

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Table 1 - US. General Population Average Dose EquivalentEstimates Source millirem (mrem)1 per Year per Person Natural Background Dose Equivalent Cosmic 33 Terrestrial 21 In the body 29 Radon 228 Total 311 Medical (effective dose equivalent) 300 Nuclear energy 0.28 Consumer Products 13 TOTAL 624.28

]One-thousandth of a Roentgen EquivalentMan (rem). By comparison, the NRC's annual radiation dose limitfor the public from any licensed activity, such as a nuclear plant, is 100 mrem As can be seen from the data presented above, natural background radiation dose equivalent to the U.S.

population exceeds that normally received from nuclear plants by several thousand times. This illustrates that routine nuclear plant operations result in population radiation doses that are insignificant compared to the dose from natural background radiation. It should be noted that the use of radiation and radioactive materials for medical uses has resulted in a similar effective dose equivalent to the U.S.

population as that caused by natural background cosmic and terrestrial radiation.

Electric Power Production Nuclear power plants are similar in many respects to conventional coal burning (or other fossil fuel) electrical generating plants. The basic process behind electrical power production in power plants is that fuel is used to heat water to produce steam which provides the force to turn turbines and generators. In a nuclear power plant, the fuel is uranium and heat is produced in the reactor through the fission of the uranium. Nuclear plants include many complex systems to control the nuclear fission process and to safeguard against the possibility of reactor malfunction. The nuclear reactions produce radionuclides commonly referred to as fission and activation products. Very small amounts of these fission and activation products are released into the plant systems. This radioactive material can be transported throughout plant systems and some of it may be released to the environment.

Paths through which radioactivity from a nuclear power plant is routinely released are monitored. Liquid and gaseous effluent monitors record the radiation levels for each release. These monitors also provide alarm mechanisms to prompt termination of any release above limits.

Releases are monitored at the onsite points of release. The radiological environmental monitoring program, which measures the environmental radiation in areas around the plant, provides a confirmation

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that releases are being properly controlled and monitored in the plant and that any resulting levels in the environment are within the established regulatory limits and a small fraction of the natural background radiation levels. In this way, the release of radioactive materials from the plant is tightly controlled, and verification is provided that the public is not exposed to significant levels of radiation or radioactive materials as the result of plant operations.

The SQN ODCM, which describes the program required by the plant technical specifications, prescribes limits for the release of radioactive effluents, as well as limits for doses to the general public from the release of these effluents.

The NRC's annual dose limit to a member of the public for all licensees is 100 mrem. The NRC's regulations for nuclear power plants require implementing a philosophy of "as low as reasonably achievable," where the dose to a member of the public from radioactive materials released from nuclear power plants to unrestricted areas is further limited on a per unit operating basis to the following:

Liquid Effluents Total body < 3 mrem/yr Any organ < 10 mrem/yr Gaseous Effluents Noble gases:

Gamma radiation < 10 millirad (mrad)/yr Beta radiation < 20 mrad/yr Particulates:

Any organ < 15 mrem/yr In addition to the NRC's regulations, the EPA limits the total dose to a member of the public due to nuclear fuel cycle facilities, including nuclear power plants. These limits, established in the Environmental Dose Standard of 40 CFR 190, are as follows:

Total body < 25 mrem/yr Thyroid <75 mrem/yr Any other organ < 25 mrem/yr Table E-l of this report presents and compares the nominal lower limits of detection (LLD) for the WBN monitoring program with the regulatory limits for maximum annual average concentration released to unrestricted areas. The table also presents the concentrations of radioactive materials in the environment which would require a special report to the NRC and the detection limits for measured radionuclides. It should be noted that the levels of radioactive materials measured in the environment are typically below or only slightly above the lower limit of detection.

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SITE AND PLANT DESCRIPTION Sequoyah is located on a site near the geographical center of Hamilton County, Tennessee, on a peninsula on the western shore of Chickamauga Lake at Tennessee River Mile (TRM) 484.5. Figure 1 shows the site in relation to other TVA projects. The SQN site, containing approximately 525 acres, is approximately 7.5 miles northeast of the nearest city limit of Chattanooga, Tennessee, 14 miles west-northwest of Cleveland, Tennessee, and approximately 31 miles south-southwest of TVA's Watts Bar Nuclear Plant (WBN) site.

Population is distributed unevenly within 10 miles of the SQN site. Approximately 60 percent of the population is in the general area between 5 and 10 miles from the plant in the sectors ranging from the south, clockwise, to the northwest sector. This concentration is a reflection of suburban Chattanooga and the town of Soddy-Daisy. This area is characterized by considerable vacant land with scattered residential subdivisions. Residential subdivision growth has continued within the 10-mile radius of the plant. There is also some small-scale farming located within 5 miles of the plant.

Chickamauga Reservoir is one of a series of highly controlled multiple-use reservoirs located on the Tennessee River whose primary uses are flood control, navigation, and the generation of electric power.

Secondary uses include industrial and public water supply and waste disposal, commercial fishing, and recreation. Public access areas, boat docks, and residential subdivisions have been developed along the reservoir shoreline.

SQN consists of two pressurized water reactors. Fuelwas loaded in Unit 1 on March 1,1980, and the unit achieved criticality on July 5, 1980. Fuel was loaded in Unit 2 in July 1981, and the unit achieved initial criticality on November 5,1981.

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Figure 1 ~~ Tennessee Volley Region

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RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM Most of the radiation and radioactivity generated in a nuclear reactor is contained within the reactor systems. Plant effluent radiation monitors are designed to monitor radionuclides released to the environment. Environmental monitoring is a final verification that the systems are performing as planned.

The monitoring program is designed to monitor the pathways between the plant and the people in the immediate vicinity of the plant. Sample types are chosen so that the potential for detection of radioactivity in the environment will be maximized. The Radiological Environmental Monitoring Program (REMP) and sampling locations for SQN are outlined in Appendix A.

There are two primary pathways by which radioactivity can move through the environment to humans:

air and water (reference Figure 2). The air pathway can be separated into two components: the direct (airborne) pathway and the indirect (ground or terrestrial) pathway. The direct airborne pathway consists of direct radiation and inhalation by humans. In the terrestrial pathway, radioactive materials may be deposited on the ground or on plants and subsequently ingested by animals and/or humans. Human exposure through the liquid pathway may result from drinking water, eating fish, or by direct exposure at the shoreline. The types of samples collected in this program are designed to monitor these pathways.

Many factors were considered in determining the locations for collecting environmental samples. The locations for the atmospheric monitoring stations were determined from a critical pathway analysis based on weather patterns, dose projections, population distribution, and land use. Terrestrial sampling stations were selected after reviewing such things as the locations of dairy animals and gardens in conjunction with the air pathway analysis. Liquid pathway stations were selected based on dose projections, water use information, and availability of media such as fish and sediment. Table A-2 lists the sampling stations and the types of samples collected. Modifications made to the SQN monitoring program in 2018 are reported in Appendix B. Deviations to the sampling program during 2018 are included in Appendix C.

To determine the amount of radioactivity in the environment prior to the operation of SQN, a preoperational radiological environmental monitoring program was initiated in 1971 and operated until the plant began operation in 1980. Measurements of the same types of radioactive materials that are measured currently were assessed during the preoperational phase to establish normal background levels for various radionuclides in the environment.

The preoperational monitoring program is a very important part of the overall program. During the 1950s, 1960s, and 1970s, atmospheric nuclear weapons testing released radioactive material to the environment causing increases in background radiation levels. Knowledge of preexisting radionuclide patterns in the environment permits a determination, through comparison and trending analyses, of the actual environmental impact of SQN operation.

The determination of environmental impact during the operating phase also considers the presence of control stations that have been established in the environment. Results of environmental samples taken at control stations (far from the plant) are compared with those from indicator stations (near the plant) to aid in the determination of the impacts from SQN operation.

In 2018 the sample analyses were performed by a contracted laboratory, GEL Laboratories, LLC, based in Charleston, SC. Analyses were conducted in accordance with written and approved procedures and are

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based on industry established standard analytical methods. A summary of the analysis techniques and methodology is presented in Appendix D.

The radiation detection devices and analysis methods used to determine the radionuclide content of samples collected in the environment are very sensitive and capable of detecting small amounts of radioactivity. The sensitivity of the measurement process is defined in terms of the lower limit of detection (LLD). A description of the nominal LLDs for the radioanalytical laboratory is presented in Appendix E.

Each laboratory applies a comprehensive quality assurance (QA)/quality control (QC) program to monitor laboratory performance throughout the year. One of the key purposes of the QA/QC program is to provide early identification of any problems in the measurement process so they can be corrected in a timely manner. This program includes instrument checks and QC sample analysis to ensure that the radiation detection instruments are functioning and being used properly. As part of an interlaboratory comparison program, the laboratory participates in a blind sample program administrated by Eckert &

Ziegler Analytics. A complete description of the program is presented in Appendix F. Appendix G contains the results of the annual land use census. Data tables summarizing the sample analysis results are presented in Appendix H. Finally, Appendix I contains any errata from previous AREORs.

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Figure 2 - Environmental Exposure Pathways ENVIRONMENTAL EXPOSURE PATHWAYS OF MAN DUE TO RELEASES OF RADIOACTIVE MATERIAL TO THE ATMOSPHERE AND LAKE.

• i_5" Diluted By Atmosphere Airborne Releases Plume Exposure X>

Liquid Releases V Diluted By Lake i! %

MAN o

Consumed By Man Animals (Milk,Meat) Shoreline Exposure o

Consumed By Animals V> ii Drinking Water Fish Vegetation Uptake From Soil

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DIRECT RADIATION MONITORING Direct radiation levels are measured at various monitoring points around the plant site. These measurements include contributions from cosmic radiation, radioactivity in the ground, fallout from atmospheric nuclear weapons tests conducted in the past, and any radioactivity that may be present from plant operations. Because of the relatively large variations in background radiation as compared to the small levels from the plant, contributions from the plant may be difficult to distinguish.

Measurement Techniques The Landauer InLight environmental dosimeter is used in the radiological environmental monitoring program for the measurement of direct radiation. This dosimeter contains four elements consisting of aluminum oxide detectors with open windows as well as plastic and copper filters. The dosimeter is processed using optically stimulated luminescence (OSL) technology to determine the amount of radiation exposure.

The dosimeters are placed approximately one meter above the ground, with two at each monitoring location. Sixteen monitoring points are located around the plant near the site boundary, one location in each of the 16 compass sectors. One monitoring point is also located in each of the 16 compass sectors at approximately four to five miles from the plant.

Dosimeters are also placed at additional monitoring locations out to approximately 32 miles from the site.

The dosimeters are exchanged every three months. The dosimeters are sent to Landauer for processing and results reporting. The values are corrected for transit and shielded background exposure. An average of the two dosimeter results is calculated for each monitoring point. The system meets or exceeds the performance specifications outlined in American National Standards Institute (ANSI) N545-1975 and ANSI N13.37-2014 for environmental applications of dosimeters.

Results All results for environmental dosimeter measurements are normalized to a standard quarter (91 days).

The monitoring locations are grouped according to the distance from the plant. The first group consists of all monitoring points within 2 miles of the plant. The second group is made up of all locations greater than 2 miles from the plant. Past data have shown that the average results from the locations more than 2 miles from the plant are essentially the same. Therefore, for purposes of this report, monitoring points 2 miles or less from the plant are identified as "onsite" stations and locations greater than 2 miles are considered "offsite."

The quarterly and annual gamma radiation levels determined from the dosimeters deployed around SQN in 2018 are summarized in Table 2. Forcomparison purposes, the average direct radiation measurements made in the preoperational phase of the monitoring program are also shown.

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Table 2 - Average External Gamma Radiation Levels at Various Distancesfrom Sequoyah NuclearPlantfor Each Quarter-2018 Average External Gamma Radiation Levels Qla Q2 Q3 Q4 Annual Preoperational (mrem/qtr) (mrem/qtr) (mrem/qtr) (mrem/qtr) (mrem/yr) (mR/yr)

Average 0-2 14.5 15.2 14.4 16.0 60.1 79 miles (onsite)3 Average >2 13.3 14.8 13.8 14.9 56.8 63 miles (offsite)3 NOTES

a. Average of the individual measurements in the set The data in Table 2 indicate that the average quarterly direct radiation levels at the SQN onsite stations are approximately 0.8 mrem/quarter higher than levels at the offsite stations. This equates to 3.3 mrem/year detected at the onsite locations, which is not statistically different than that measured during the preoperational program. Even considering this 3.3 mrem/yr increase for onsite locations attributable to plant operations, it falls below the 25 mrem total body limit for 40 CFR 190. The difference in onsite and offsite averages is consistent with levels measured for the preoperational and construction phases of TVA nuclear power plant sites where the average levels onsite were slightly higher than levels offsite.

Figure 3 compares plots of the data from the onsite stations with those from the offsite stations over the period from 1977 through 2018. Landauer InLight Optically Stimulated Luminescence (OSL) dosimeters have been deployed since 2007, replacing the Panasonic UD-814 dosimeters used during the previous years. Beginning with 2018, the methodology for evaluating and reporting the environmental direct radiation exposure was modified, to reflect recommendations contained in ANSI N13.37-2014. A study was performed to determine the dose received by dosimeters that are used as unexposed controls to account for the transit dose to all dosimeters and the shielded storage dose to the unexposed control dosimeters. This in turn was used to correctly account for the extraneous dose that should be removed from the gross measurements as measured by the field dosimeters.

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Figure 3 - Average Direct Radiation Direct Radiation Levels Sequoyah Nuclear Plant Four Quarter Moving Average 24.0 InifcalSQNP operator? m Jtiy,1980 inucftt Oo*$meier Deployment in January.

2007 1

2

^w^4ffi 16.0 12.0 1975 1980 1985 1990 2010 2015 2020

-Off-Site Table H-1 contains the results of the individual monitoring stations. The results reported in 2018 are consistent with historical and preoperational results, indicating that there is no measurable increase in direct radiation levels in the offsite environment attributable to the operation of SQN. There is no indication that SQN activities increased the background radiation levels normally observed in the areas surrounding the plant.

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ATMOSPHERIC MONITORING The atmospheric monitoring network is divided into three groups identified as local, perimeter, and remote. Four local air monitoring stations are located on or adjacent to the plant site in the general directions of greatest wind frequency. Four perimeter air monitoring stations are located between 6 to 11 miles from the plant, and two air monitors are located out to 15 miles and used as control or baseline stations. The monitoring program and the locations of monitoring stations are identified in the tables and figures of Appendix A.

Results from the analysis of samples in the atmospheric pathway are presented in Table H-2 through Table H-4. Radioactivity levels identified in this reporting period are consistent with background and preoperational program data. There is no indication of an increase in atmospheric radioactivity due to SQN operations.

Sample Collection and Analysis Air particulates are collected by continuously sampling air at a flow rate of approximately 2 cubic feet per minute (cfm) through a 2-inch glass fiber filter. The sampling system consists of a Vacuum Florescent Display (VFD), a brushless motor, and a precision-machined mechanical differential pressure flow sensor.

It is equipped with automatic flow control, on-board data storage, and various alarm notifications. This system is housed in a weather resistant environmental enclosure approximately 3 feet by 2 feet by 4 feet.

The filter is contained in a sampling head mounted on the outside of the monitoring building. The filter is replaced weekly. Each filter is analyzed for gross beta activity about 3 days after collection to allow time for the radon daughters to decay. Every 4 weeks composites of the filters from each location are analyzed by gamma spectroscopy.

Gaseous radioiodine is sampled using a commercially available cartridge containing Triethylenediamine (TEDA)-impregnated charcoal. This system is designed to collect iodine in both the elemental form and as organic compounds. The cartridge is in the same sampling head and downstream of the air particulate filter. The cartridge is changed at the same time as the particulate filter and samples the same volume of air. Each cartridge is analyzed for 1-131 by gamma spectroscopy.

Results The results from the analysis of air particulate samples are summarized in Table H-2. Gross beta activity in 2018 was consistent with levels reported in previous years. The average gross beta activity measured for air particulate samples from both indicator and control locations was 0.033 pCi/m3. The annual averages of the gross beta activity in air particulate filters at these stations for the period 1977-2018 are presented in Figure H-1. Increased levels due to fallout from atmospheric nuclear weapons testing are evident in the years prior to 1981 and a small increase from the Chernobyl accident can be seen in 1986.

These patterns are consistent with data from monitoring programs conducted by TVA at other nuclear power plant construction sites. In 2017, GEL Laboratories, LLC took over radiochemistry analysis for the BFN REMP program. Since that change, the air filter gross beta results increased from a long-term average of approximately0.02 pCi/m3 to approximately0.03 pCi/m3. This isthe result of the new laboratory using a different calibration source (Tc-99) than the prior laboratory (Sr-90). The current results are consistent

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between indicator and control samples, and consistent with results from other nuclear power plant environmental monitoring programs, including both TVA and non-TVA facilities.

Only natural radioactive materials were identified by the monthly gamma spectral analysis of the air particulate samples. As shown in Table H-3, 1-131 was not detected in any charcoal cartridge samples collected in 2018.

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TERRESTRIAL MONITORING Terrestrial monitoring is accomplished by collecting samples of environmental media that may transport radioactive material from the atmosphere to humans. For example, radioactive material may be deposited on a vegetable garden and be ingested along with the vegetables or it may be deposited on pasture grass where dairy cattle are grazing. When the cow ingests the radioactive material, some of it may be transferred to the milk and consumed by humans who drink the milk. Therefore, samples of milk, soil, and food crops are collected and analyzed to determine potential impacts from exposure through this pathway. The results from the analysis of these samples are shown in Table H-5 and Table H-6.

A land use census is conducted annually between April and October to identify the location of the nearest milk animal, the nearest residence, and the nearest garden of greater than 500 square feet producing fresh leafy vegetables in each of 16 meteorological sectors within 5 miles from the plant. This land use census satisfies the requirements 10 CFR 50, Appendix I, Section IV.B.3. The results of the 2018 land use census are presented in Appendix G.

Sample Collection and Analysis There is no milk pathway currently applicable to SQN. In previous years, there was a milk consumption pathway at one location applicable to SQN and was monitored via milk or vegetation samples at the location. The land use census will continue to monitor if the milk pathway becomes applicable to SQN again.

Soil samples are collected annually from the area surrounding each air monitoring station. The samples are collected with either a "cookie cutter" or an auger type sampler. After drying and grinding, the sample is analyzed by gamma spectroscopy. When the gamma analysis is complete, the sample is analyzed for Sr-89 and Sr- 90.

Samples representative of food crops raised in the area near the plant are obtained from individual gardens. Types of foods may vary from year to year due to changes in the local vegetable gardens.

Samples of cabbage, corn, pears, potatoes, green beans, and tomatoes were collected from local vegetable gardens and/or farms. Samples of the same food products grown in areas that would not be affected by the plant were obtained from area produce markets as control samples. The edible portion of each sample is analyzed by gamma spectroscopy.

Results The gamma analysis of soil samples detected trace levels of Cs-137. The concentrations of Cs-137 are consistent with levels previously reported from fallout. One sample from indicator location LM-4 was positive for Sr-90 at 0.117 pCi/g. All other radionuclides reported were naturally occurring isotopes. No Sr-89 was identified in SQN soil samples in 2018. The soil analysis data are provided in Table H-5.

A plot of the annual average Cs-137 concentrations in soil is presented in Figure H-2 The concentrations of Cs-137 in soil are steadily decreasing due to the cessation of weapons testing in the atmosphere, the 30-year half-life of Cs-137 and transport through the environment.

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Radionuclides reported in food samples were all naturally occurring. Analysis of these samples indicated no contribution from plant activities. The results are reported in Table H-6.

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LIQUID PATHWAY MONITORING Potential exposures from the liquid pathway can occur from drinking water, ingestion of edible fish, or from direct radiation exposure from radioactive materials deposited in the river sediment. The monitoring program includes the collection of samples of surface water, groundwater, drinking water supplies, fish, and shoreline sediment. Samples from the reservoir are collected both upstream and downstream from the plant.

Sample Collection and Analysis Samples of surface water are collected from the Tennessee River downstream and upstream of the plant using automatic sampling systems. A timer turns on the system at least once every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and the sample is collected into a composite jug. A 1-gallon sample is removed from the composite jug at 4-week intervals and the remaining water in the jug is discarded. The composite sample is analyzed for gamma emitting radionuclides and gross beta activity. A quarterly composite sample is analyzed for tritium.

Samples are collected by an automatic sampling system at the first downstream drinking water intake and at the water intake for the city of Dayton located approximately 20 miles upstream. At other selected locations, grab samples are collected from drinking water systems which use the Tennessee River as their source. The drinking water samples are analyzed every 4 weeks by gamma spectroscopy and for gross beta activity. A quarterly composite sample from each station is analyzed for tritium. Additional tritium analyses are performed on samples from two of the locations that are shared with the Watts Bar monitoring program. The sample collected at the water intake for the city of Dayton also serves as control sample for surface water.

Groundwater is sampled from an onsite well using an automatic composite sampler and a grab sample is collected quarterly from a private well in an area unaffected by SQN. Gamma spectroscopy and tritium analyses are performed monthly on samples from the onsite well and gross beta analysis is performed on a quarterly composite sample. The samples from the offsite well are analyzed by gamma spectroscopy and for tritium and gross beta activity.

Samples of commercial and game fish species are collected semiannually from each of two reservoirs: the reservoir on which the plant is located (Chickamauga Reservoir) and the upstream reservoir (Watts Bar Reservoir). The samples are collected using a combination of netting techniques and electrofishing.

Samples are prepared from filleted fish. After drying and grinding, the samples are analyzed by gamma spectroscopy.

Samples of shoreline sediment are collected from two downstream recreational use areas and one upstream location. The samples are dried and ground and analyzed by gamma spectroscopy.

Results There were no fission or activation product radionuclides identified from the gamma spectroscopy analyses performed on surface water samples. Tritium activity above the nominal LLD value was measured in samples of surface water. The tritium concentrations in two monthly samples from the control location averaged 298 pCi/liter. These tritium concentrations are considered background and represent only a small fraction of the Environmental Protection Agency (EPA) drinking water limit of

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20,000 pCi/liter. The values were consistent with previously reported values. A summary table of the results is shown in Table H-7.

There were no fission or activation product radionuclides identified by the gamma analysis of drinking water samples. Tritium activity above the nominal LLD value was measured in drinking water samples.

The tritium concentrations in three samples from one indicator location averaged 302 pCi/liter and from two samples from the control location averaged 298 pCi/liter. These tritium levels represented only a small fraction of the EPA drinking water limit of 20,000 pCi/liter. The values were consistent with previously reported values. No gross beta activity was identified in the downstream (indicator) location samples, but one upstream (control) location sample was positive for gross beta at 3.2 pCi/liter. The results are shown in Table H-8.

No fission or activation products were detected by the gamma analyses performed on groundwater samples from the REMP monitoring locations. Tritium was not detected in any collected ground water samples. No gross beta activity was detected for indicator location samples. The average gross beta concentration in samples from the offsite well control location was 11.6 pCi/liter. These gross beta levels are representative of the levels typically found in groundwater. The results from the analysis of groundwater samples are presented in Table H-9.

In 2018, game fish (large mouth bass) and commercial fish (channel catfish) were sampled and analyzed from both control and indicator locations. No fission or activation products were identified in any of the samples. The results are summarized in Table H-10.

No fission or activation products were detected by the gamma analyses performed on shoreline sediment samples from the REMP monitoring locations. All other radionuclides reported were naturally occurring isotopes. Results from the analysis of shoreline sediment samples are shown in Table H-ll.

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ASSESSMENT AND EVALUATION Potential doses to the public are estimated from measured effluents using computer models. These models were developed by TVA and are based on methodology provided by the NRC in Regulatory Guide 1.109 for determining the potential dose to individuals and populations living near a nuclear power plant.

The results of the effluent dose calculations are reported in the Annual Radioactive Effluent Release Report. The doses calculated are a representation of the dose to a "maximum exposed individual." Some of the factors used in these calculations (such as ingestion rates) are maximum expected values which will tend to overestimate the dose to this "hypothetical" person. The calculated maximum doses due to plant effluents are small fractions of the applicable regulatory limits. The expected dose to actual individuals is significantly lower.

Based on the very low concentrations of radionuclides present in plant effluent, the calculated doses as a result of plant operations are small fractions of regulatory limits and the natural background radiation dose. The results for the radiological environmental monitoring conducted for the SQN 2018 operations confirm this expectation Results As stated earlier in this report, the estimated increase in radiation dose equivalent to the general public resulting from the operation of SQN is negligible when compared to the dose from natural background radiation. The results from environmental samples are compared with the concentrations from the corresponding control stations as well as appropriate preoperational and background data to determine influences from the plant. Measurable levels of Cs-137 and Sr-90 (at a very low level) were detected in soil. The Cs-137 concentrations are consistent with levels identified previously that are the result of fallout from past atmospheric nuclear weapons testing. The low levels of tritium measured in water samples from the onsite well represented concentrations that were significantly lower than the EPA drinking water limit.

Conclusions The 2018 radiological environmental monitoring program results demonstrate that exposure to members of the general public,which may have been attributable to SQN, is a small fraction of regulatory limits and essentially indistinguishable from the natural background radiation. The radioactivity reported herein is primarily the result of fallout or natural background. Any activity which may be present in the environment as a result of plant operations does not represent a significant contribution to the exposure of members of the public.

[19]

REFERENCES GEL. (2018). 2018 Annual Quality Assurance Report for the Radiological Environmental Monitoring Program (REMP). Charleston, SC.

NCRP. (March 2009). Report No. 160, Ionizing Radiation Exposure of the Population of the United States.

NCRP, Washington, D.C.

TVA. (2018). Sequoyah Nuclear Plant Offsite Dose Calculation Manual, Revision 63.

U.S. NRC. (1991). NUREG-1301 Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Pressurized Water Reactors, Generic Letter 89-01, Supplement 1. Washington, D.C:

USNRC. Retrieved from http://www.nrc.gov/docs/ML0910/ML091050061.pdf U.S. NRC. (February 1996). Instruction Concerning Risksfrom Occupational Exposure. USNRC, Washington, D.C.

[20]

APPENDIX A RADIOLOGICAL ENVIRONMENTAL MONITORING PROG RAM AN D SAM PLING LOCATIONS

[21]

APPENDIX A Table A-l - Sequoyah Radiological Environmental Monitoring Program Exposure Pathway and/or Sample Number of Samples and Locations3 Sampling and Collection Type and Frequency of Analysis Frequency

1. AIRBORNE

a. Particulates 4 samples from locations (in different sectors) Continuous sampler operation Analyze for gross beta radioactivity >

at or near the site boundary (LM-2, 3, 4 and 5) with sample collection weekly 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following filter change.

(more frequently if required by Perform gamma isotopic analysis on 4 samples from communities approximately 6- dust loading) each sample if gross beta > 10 times 10 miles from plant (PM-2, 3, 8 and 9) yearly mean of control sample.

Composite at least once per 31 days 4 samples from control locations > 10 miles (by location) for gamma from the plant (RM-1, 2, 3 and 4) spectroscopy.

b. Radioiodine Samples from same locations as air particulates Continuous sample operation 1-131 by gamma spectroscopy on with filter collection weekly. each sample.

c. Soil Samples from same location as air particulates Annually Gamma spectroscopy, Sr-89, Sr-90 annually

2. DIRECT

a. Dosimeters 2 or more dosimeters placed at or near the site Quarterly (once per 92 days) Gamma dose quarterly (at least boundary in each of the 16 sectors. once per 92 days) 2 or more dosimeters placed at stations located approximately 4 to 5 miles from the plant in each of the 16 sectors.

2 or more dosimeters in other locations of special interest.

[22]

APPENDIX A TableA-l - Sequoyah RadiologicalEnvironmental Monitoring Program (Continued)

Exposure Pathway and/or Sample Number of Samples and Locations Sampling and Collection Type and Frequency of Analysis Frequency

3. WATERBORNE

a. Surface Water TRM 503.8 Collected by automatic Gross beta and gamma spectroscopy sequential-type sampler6 with on each sample. Composite for TRM 483.4 composite samples collected tritium analysis at least once per 92 over a period of approximately days.

31 days.

b. Ground water 1 sample adjacent to the plant (Well #6) Quarterly (Once per 92 days) Gross beta, gamma spectroscopy, and tritium analysis of each sample.

1 sample from ground water source up gradient (Farm HW).

c. Drinking Water 1 sample at the first potable surface water Monthly (once per 31 days) Gross beta and gamma scan of each supplies, downstream from the plant (TRM sample.

473.0). Composite for tritium once per 92 days.

1 sample at the next 2 downstream potable water systems (greater than 10 miles downstream) (TRM 469.9 and TRM 465.3) 1 sample at a control location (TRM 503.8)c

d. Shoreline Sediment TRM 485 Semi-Annually (at least once Gamma spectroscopy of each per 184 days) sample TRM 480 TRM 479

[23]

APPENDIX A Table A-l - Sequoyah Radiological Environmental Monitoring Program (Continued)

Exposure Pathway and/or Sample Number of Samples and Locations Sampling and Collection Type and Frequency of Analysis Frequency

4. INGESTION

a. Milk N/A. As of 2017, the milk pathway is not Once per 15 days 1-131 and gamma spectroscopy on applicable to SQN. each sample. Sr-89 and Sr-90 quarterly.

b. Fish One sample of commercially important species Semi-Annually (at least once Gamma spectroscopy on edible and one sample of recreationally important per 184 days) portions species. One sample of each species from Chickamauga and Watts Bar Reservoirs.

c. Vegetationd Samples from farms producing milk but not Monthly (at least once per 31 1-131 analysis and gamma (Pasturage and grass) providing a milk sample days) spectroscopy of each sample

d. Food Products 1 sample of each principal food products grown Annually at time of harvest. Gamma spectroscopy on edible at private gardens and/or farms in the The types of foods available for portions immediate vicinity of the plant. sampling will vary. Typically available foods may include:

1 sample of each of the same foods grown at

• Cabbage greater than 10 miles distance from the plant.

• Corn

• Green Beans

• Potatoes

• Tomatoes a Sample locations are shown on Figure A-l through Figure A-3.

bSamples shall be collected by collecting an aliquot at intervals not exceeding 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> cThe samples collected at TRMs 503.8 are taken from the raw water supply, therefore, the upstream surface water sample will be considered the control sample for drinking water dVegetation sampling is applicable only for farms that meet the criteria for milk sampling and when milk sampling cannot be performed

[24]

APPENDIX A Table A Sequoyah REMP Sampling Locations Map Location Distance Indicator (1) or Number3 Station Sector (miles) Control (C) Samples Collected5 2 LM-2 N 0.7 AP,CF,S 3 LM-3 ssw 2.0 AP,CF,S 4 LM-4 NE 1.5 AP,CF,S 5 LM-5 NNE 1.8 AP,CF,S 7 PM-2 sw 3.8 AP,CF,S 8 PM-3 w 5.6 AP,CF,S 9 PM-8 ssw 8.7 AP,CF,S 10 PM-9 wsw 2.6 AP,CF,S 11 RM-1 sw 16.7 C AP,CF,S 12 RM-2 NNE 17.8 C AP,CF,S 13 RM-3 ESE 11.3 c AP,CF,S 14 RM-4 NW 20.0 c AP,CF,S 19 Farm HW NW 1.2 1 Wc 24 Well No. 6 NNE 0.15 1 W 31 TRM 473.0 10.7d 1 PW (East Side Utilities)0 32 TRM 469.9 ""

13.8d 1 PW (E. 1. DuPont) 33 TRM 465.3 18.4d 1 PW (Chattanooga) 35 TRM 503.8 (Dayton) - 20.1d c PW,SW 37 TRM 485.0 -

1.3d c ss 38 TRM 483.4 -

0.3d 1 SW 40 TRM 479.0 -_

4.7d 1 ss 44 TRM 480.0 -

3.7d 1 ss 46 Chickamauga Reservoir 1 F (TRM 471-530) 47 Watts Bar Reservoir c F (TRM 530-602) a See Figure A-1 through Figure A-3 bSample Codes:

AM = Atmospheric moisture PW = Public water ss = Shoreline sediment AP = Air particulate filter V = Vegetation sw = Surface water F = Fish s = Soil w = Well water CF = Charcoal Filter M = Milk c A control for well water d Distance from plant discharge (TRM 483.7)

[25]

APPENDIX A Table A Sequoyah Environmental Dosimeter Locations Map Location Distance Onsite or Number3 Station Sector (miles) Offsiteb 3 SSW-1C SSW 2.0 off 4 NE-1A NE 1.5 onsite 5 NNE-1 NNE 1.8 onsite 7 SW-2 SW 3.8 off 8 W-3 W 5.6 off 9 SSW-3 SSW 8.7 off 10 WSW-2A WSW 2.6 off 11 SW-3 SW 16.7 off 12 NNE-4 NNE 17.8 off 13 ESE-3 ESE 11.3 off 14 NW-3 NW 20.0 off 49 N-l N 0.6 onsite 50 N-2 N 2.1 off 51 N-3 N 5.2 off 52 N-4 N 10.0 off 53 NNE-2 NNE 5.3 off 55 NE-1 NE 2.4 off 56 NE-2 NE 4.1 off 57 ENE-1 ENE 0.2 onsite 58 ENE-2 ENE 5.1 off 59 E-l E 1.2 onsite 60 E-2 E 5.2 off 62 ESE-1 ESE 1.2 onsite 63 ESE-2 ESE 4.9 off 66 SE-1 SE 1.4 onsite 67 SE-2 SE 1.9 onsite 68 SE-4 SE 5.2 off 69 SSE-1 SSE 1.6 onsite 70 SSE-2 SSE 4.6 off 71 S-l S 1.5 onsite 72 S-2 S 4.7 off 73 SSW-1 SSW 0.6 onsite 74 SSW-2 SSW 4.0 off 75 SW-1 SW 0.7 onsite 76 WSW-1 WSW 0.9 onsite 77 WSW-2 WSW 2.5 off 78 WSW-3 WSW 5.7 off 79 WSW-4 WSW 7.8 off 81 W-l W 0.6 onsite 82 W-2 w 4.3 off 83 WNW-1 WNW 0.4 onsite

[26]

APPENDIX A Table A Sequoyah Environmental Dosimeter Locations (Continued)

Map Location Distance Onsite or Number Station Sector (miles) Offsite 84 WNW-2 WNW 5.3 Off 85 NW-1 NW 0.4 onsite 86 NW-2 NW 5.2 off 87 NNW-1 NNW 0.6 onsite 88 NNW-2 NNW 1.7 onsite 89 NNW-3 NNW 5.3 off 90 SSW-1B SSW 1.5 onsite a See Figure A-1 through Figure A-3 b Dosimeters designated "onsite" are located 2 miles or less from the plant; "offsite" are located more than 2 miles from the plant

[27]

APPENDIX A Figure A RadiologicalEnvironmental Sampling Locations Within 1 Mile of the Plant 348.7$ N 11.25 NNW ^s*z=-^**z*L^ NNE 326.25 33.75 303.7 5 56.25 WNW ENE 281.25 78.75 258.75 101.25 WSW ESE 236.25 213.75 Scale Mile

[28]

APPENDIX A Figure A~2 - Radiological Environmental Sampling Locationsfrom ItoS Miles from the Plant 348.75 11.25 33.75 303.75 56.25 WNW ENE 281.25 78.75

-E 258J5 101.26 WSW ESE 236*25 123.75 213.75 101.25

[29]

APPENDIX A FigureA Radiological EnvironmentalSampling Locations Greater Than 5 Miles from the Plant 348.75 9 a 11,26 CH03Svn.tr 320.25 33.75 303.75, 281.25 78.75 258.7I 101.26 123,70 146.25 191.25 SCALE isf>- -w?>>

[30]

APPENDIX B PROGRAM MODIFICATIONS

[31]

APPENDIX B Radiological Environmental Monitoring Program Modifications In 2018, there are no changes to the Radiological Environmental Monitoring Program for SQN.

[32]

APPENDIX C PROGRAM DEVIATIQNS

t33]

APPENDIX C Program Deviations Media Location Date CR Issue Direct SSE-140A 12/31/2018 1481235 Both OSLDs missing on Harrison Bay Road Radiation and 40B Location 40A and 40B, SQ-SSE-1.

Air Filter, PM8 5/10/2018 1412728 PM-8 sampler found with broken belt.

Charcoal Filter PM2 7/25/2018 1434060 PM-2 REMP sampler was found not running during weekly sample. The sampler had collected 16700 cubic feet (412.8 cubic meters true volume) of sample prior to turning off so this is not a missed sample.

LM-2 11/13/2018 1468928 Insufficient volume on air filters. LM-2 sampler LM-5 not working. LM-5 has a broken belt.

RM-2 12/24/2018 1495778 Missing gross beta and 1-131 sample. No power (common at location.

location to WBN)

Surface TRM 12/11/2018 1502177 Sampler inoperable. Temporary sampler water 483.4 installed in January 2019.

Well Water 2204 H. 2/12/18 1386412 Unable to obtain sample due to frozen lines.

Walker Dip sample not available.

Farm 2204 H. 11/28/2018 1470901 The H Walker Farm REMP sample was not Walker scheduled appropriately. A sample was not Farm collected in Quarter 3 2018. The Q4 sample was collected as required. Corrective actions include more periodic reviews of sample requirements and to include the deviation in the annual REMP report.

[34]

APPENDIX D ANALYTICAL PROCEDURES

[35]

APPENDIX D Analytical Procedures Analyses of environmental samples are performed by GEL Laboratories, LLC in Charleston, SC. Analysis of environmental dosimeters is performed by Landauer, Inc. in Glenwood, IL. Analysis procedures are based on accepted methods and summarized below.

The gross beta measurements are made with an automatic low background counting system. Normal counting times are 50 minutes. Water samples are prepared by evaporating 400 milliliter (mL) of samples to near dryness, transferring to a stainless steel planchet, and completing the evaporation process. Air particulate filters are counted directly in a shallow planchet.

The specific analysis of 1-131 in milk is performed by first isolating and purifying the iodine by radiochemical separation and then counting the final precipitate on a beta-gamma coincidence counting system. The normal count time is 480 minutes. When the 1-131 counted in a gamma spectroscopy utilizing high resolution Hp-Ge detectors.

After a radiochemical separation, milk samples analyzed for Sr-89, 90 are counted on a low background beta counting system. The sample is counted a second time after a minimum ingrowth period of six days.

From the two counts, the Sr-89 and Sr-90 concentrations can be determined.

Water samples are analyzed for tritium content by first distilling a portion of the sample and then counting by liquid scintillation. A commercially available scintillation cocktail is used.

Gamma analyses are performed in various counting geometries depending on the sample type and volume. All gamma counts are obtained with germanium type detectors interfaced with a high resolution gamma spectroscopy system.

The charcoal cartridges used to sample gaseous radioiodine are analyzed by gamma spectroscopy using a high resolution gamma spectroscopy system with germanium detectors.

Atmospheric moisture samples are collected on silica gel from a metered air flow. The moisture is released from the silica gel by heating and a portion of the distillate is counted by liquid scintillation for tritium using commercially available scintillation cocktail.

The necessary efficiency values, weight-efficiency curves, and geometry tables are established and maintained on each detector and counting system. A series of daily and periodic quality control checks are performed to monitor counting instrumentation. System logbooks and control charts are used to document the results of the quality control checks.

The Landauer InLight Environmental Dosimetry System is used for measuring direct radiation in the REMP.

Landauer has performed type testing of this system in accordance with ANSI N13.37-2014 standards.

[36]

APPENDIX E LOWER LIMITS OF DETECTION

[37J

APPENDIX E Lower Limits of Detection Many factors influence the Lower Limit of Detection (LLD) for a specific analysis method, including sample size, count time, counting efficiency, chemical processes, radioactive decay factors, and interfering isotopes encountered in the sample. The most probable values for these factors have been evaluated for the various analyses performed in the environmental monitoring program. The nominal LLDs are calculated from these values, in accordance with the methodology prescribed in the ODCM. The current nominal LLD values achieved by the radioanalytical lab are listed in Table E-2 and Table E-3. For comparison, the maximum values for the lower limits of detection specified in the ODCM are given in Table E-4.

Table E-l - Comparison of Program Lower Limits of Detection with the Regulatory Limits for Maximum Annual Average Effluent Concentration Released to Unrestricted Areas and Reporting Levels Concentrations in Water (pCi/Liter) Concentrations in Air (pCi/m3) 10 CFR 20 10 CFR 20 Effluent Lower Effluent Lower Concentration Reporting Limit of Concentration Reporting Limit of Analysis Limit8 Levelb-c Detectiond Limit3 Level"-0 Detection"1 H-3 1,000,000 20,000 270 100,000 ~ -

Cr-51 500,000 - 45 30,000 ~ 0.02 Mn-54 30,000 1000 5 1,000 -- 0.005 Fe-59 10,000 400 10 500 - 0.005 Co-58 20,000 1000 5 1,000 - 0.005 Co-60 3,000 300 5 50 - 0.005 Zn-65 5,000 300 10 400 - 0.005 Sr-89 8,000 - - 1,000 -- ~

Sr-90 500 - - - 6 - -

Nb-95 30,000 400 5 2,000 ~ 0.0005 Zr-95 20,000 400 10 400 ~

0.005 Ru-103 30,000 - 5 900 - 0.005 Ru-106 3,000 - 40 20 - 0.02 1-131 1,000 2 0.4 200 0.9 0.03 Cs-134 900 30 5 200 10 0.005 Cs-137 1,000 50 5 200 20 0.005 Ce-144 3,000 ~ 30 40 ~ 0.01 Ba-140 8,000 200 25 2,000 - 0.015 La-140 9,000 200 10 2,000 0.01 a Source: Table 2 of Appendix B to 10 CFR20.1001-20.2401 bFor those reporting levels and lowerlimits of detection that are blank, no value isgiven in the reference c Source: SQN Offsite Dose Calculation Manual, Table 2.3-2 dSource: Table E-2 and Table E-3 of this report

[38]

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APPENDIX E Table E Nominal LLD Values - Gamma Analysis (continued)

Water Wet Sediment Food Airborne Charcoal and Vegetation and Soil Fish Products Particulate Filter Milk (pCi/ks, (pCi/kg. (PCi/kg, (PCi/kg, Analysis (pCi/m3) (pCi/m3) (pCi/L) wet) dry) wet) wet)

Bi -214 0.005 0.05 20 55 0.15 0.10 40 Bi-212 0.02 0.20 50 250 0.45 0.25 130 TI-208 0.002 0.02 10 30 0.06 0.03 30 Ra-224 - - -

- 0.75 - -

Ra-226 - - ~ - 0.15 ~ -

Ac-228 0.01 0.07 20 70 0.25 0.10 50 Pa-234m 800 4.0 Table E Maximum Values for Lower Limits of Detection (LLD)

Airborne Particulate or Fish Food Water Gases (PCi/kg, Milk Products Sediment Analysis (oCi/L) (pCi/m3) wet) (PCi/L) (pCi/kg, wet) (pCi/kg, dry)

Gross beta 4 0.01 -

H-3 20003 ~ -

Mn-54 15 - 130 Fe-59 30 - 260 Co-58, 60 15 - 130 Zn-65 30 - 260 Zr-95 30 - -

Nb-95 15 - -

1-131 lb 0.07 - 1 60 Cs-134 15 0.05 130 15 60 150 Cs-137 18 0.06 150 18 80 180 Ba-140 60 - - 60 La-140 15 15 Notes

a. If no drinking water pathway exists, a value of 3000 pCi/L may be used

b. If no drinking water pathway exists, a value of 15 pCi/L may be used.

[40]

APPENDIX F QUALITY ASSURANCE /QUALITY CONTROL PROGRAM

[41]

APPENDIX F Quality Assurance / Quality Control Program A quality assurance program is employed by the offsite vendor laboratory to ensure that the environmental monitoring data are reliable. This program includes the use of written, approved procedures in performing the work, provisions for staff training and certification, internal self-assessments of program performance, audits by various external organizations, and a laboratory quality control program.

The quality control program employed by the radioanalytical laboratory is designed to ensure that the sampling and analysis process is working as intended. The program includes equipment checks and the analysis of quality control samples, along with routine field samples. Instrument quality control checks include background count rate and counts reproducibility. In addition to these two general checks, other quality control checks are performed on the variety of detectors used in the laboratory. The exact nature of these checks depends on the type of device and the method it uses to detect radiation or store the information obtained.

Quality control samples of a variety of types are used by the laboratory to verify the performance of different portions of the analytical process. These quality control samples include blanks, field duplicates, process duplicates, matrix spikes, laboratory control samples, and independent cross-checks.

Blanks are samples which contain no measurable radioactivity of the type being measured. Such samples are analyzed to determine whether there is any contamination or cross-contamination of equipment, reagents, processed samples, or interferences from isotopes other than the ones being measured.

Duplicate field samples are generated at random by the sample computer program which schedules the collection of the routine samples. For example, if the routine program calls for four milk samples every week, on a random basis each farm might provide an additional sample several times a year. These duplicate samples are analyzed along with other routine samples. They provide information about the variability of radioactive content in the various sample media. If enough sample is available for a particular analysis, the laboratory staff can split the sample taking two individual aliquots, known as process duplicates. Duplicate samples provide information about the variability of the entire sampling and analytical process.

Matrix spikes are field samples that have been spiked with known low levels of specific target isotopes.

Recovery of the known amount allow the analyst to determine if any interferences are exhibited from the field sample's matrix.

Laboratory control samples are another type of quality control sample. A known amount of radioactivity is added to a sample medium and processed along with the other QC and field samples in the analytical batch. Laboratory control samples provide the assurance that all aspects of the process have been successfully completed within the criteria established by Standard Operating Procedure.

Another category of quality control samples are cross-checks. The laboratory procures single-blind performance evaluation samples from Eckert & Ziegler Analytics to verify the analysis of sample matrices processed at the laboratory. Samples are received on a quarterly basis. The laboratory's Third-Party Cross-Check Program provides environmental matrices encountered in a typical nuclear utility REMP.

Once performance evaluation samples have been prepared in accordance with the instructions from the performance evaluator provider, samples are managed and analyzed in the same manner as

[42]

APPENDIX F environmental samples. These samples have a known amount of radioactivity added and are presented to the lab staff labeled as cross-check samples. The laboratory does not know the amount of radioactivity added to the sample. Such samples test the best performance of the laboratory by determining if the laboratory can find the "right answer." These samples provide information about the accuracy of the measurement process. Further information is available about the variability of the process if multiple analyses are requested on the same sample. Like matrix spikes or laboratory control samples, these samples can also be spiked with low levels of activity to test detection limits. The analysis results for internal cross-check samples met program performance goals for 2018.

The quality control data are routinely collected, examined and reported to laboratory supervisory personnel. They are checked for trends, problem areas, or other indications that a portion of the analytical process needs correction or improvement. The result is a measurement process that provides reliable and verifiable data and is sensitive enough to measure the presence of radioactivity far below the levels which could be harmful to humans.

Per the GEL 2018 Annual Environmental Quality Assurance (QA) Report (GEL, 2018), forty-five (45) radioisotopes associated with seven (7) matrix types (air filter, cartridge, water, milk, soil, liquid and vegetation) were analyzed under GEL's Performance Evaluation program in participation with ERA, MAPEP, and Eckert & Ziegler Analytics. Matrix types were representative of client analyses performed during 2018. Of the four hundred fifty-two (452) total results, 98.4% (445 of 452) were found to be acceptable within the PT providers three sigma or other statistical criteria. For the Eckert 8t Ziegler Analytics Environmental Cross Check Program, GEL was provided ninety-two (92) individual environmental analyses. The accuracy of each result reported to Eckert & Ziegler Analytics, Inc. is measured by the ratio of GEL's result to the known value. All results fell within GEL's acceptance criteria (100% within acceptance).

The radioanalytical lab performance in 2018 meets the criteria described in Reg. Guide 4.15 and ANSI/HPS N 13.37-2014.

[43]

APPENDIX G LAND USE CENSUS m\

APPENDIX G Land Use Census A land use census is conducted annually to identify the location of the nearest milk producing animal, the nearest residence, and the nearest garden of greater than 500 square feet producing fresh leafy vegetables in each of 16 meteorological sectors within 5 miles (8,047 meters) from the plant.

The land use census is conducted between April 1 and October 1 using appropriate techniques such as door-to-door survey, mail survey, telephone survey, aerial survey, or information from local agricultural authorities or other reliable sources.

There was one change in the location of the nearest resident as identified in 2018 compared to 2017: the nearest residence in the NE sector is now 3400 meters, a significant increase from 2017. The location of the nearest garden changed or was updated in just one sector (NE) but the distance from the plant remained the same.

Table 6-i - Sequoyah Land Use Census Results Nearest Nearest Nearest Milk Meteorological Resident Garden Production Sector (meters) (meters) (meters)

N 1389 4329 -

NNE 2456 3770 -

NE 3400 6230 -

ENE 2127 5220 -

E 1685 5370 -

ESE 1693 1861 -

SE 1721 3406 -

SSE 2073 6190 -

S 1764 4137 -

SSW 2129 4532 -

SW 2502 4920 -

WSW 1036 1152 -

w 982 3050 -

WNW 1331 5363 -

NW 1316 1316 -

NNW 864 1975 -

[45]

APPENDIX H DATA TABLES AND FIGURES

[46]

APPENDIX H Table H Individual Dosimeter Stations at Sequoyah Nuclear Riant Map Ql Q2 Q3 Q4 Annual Loc. Station Dir. Distance 2018 2018 2018 2018 Exposure No. Number (degrees) (miles) (mrem/qtr) (mrem/yr) 3 SSW-1C 198 2.0 12.0 14.3 10.8 11.3 48.3 4 NE-1A 50 1.5 16.0 14.8 14.7 17.8 63.3 5 NNE-1 13 1.8 15.5 20.3 15.8 17.8 69.3 7 SW-2 227 3.8 14.0 13.8 14.3 15.8 57.8 8 W-3 280 5.6 11.0 12.8 13.3 12.3 49.3 9 SSW-3 203 8.7 15.0 18.3 12.7 18.3 64.3 10 WSW-2A 250 2.6 12.0 15.3 10.8 11.8 49.8 11 SW-3 228 16.7 15.0 17.3 18.3 17.3 67.8 12 NNE-4 32 17.8 14.4 17.2 16.1 17.1 64.8 13 ESE-3 117 11.3 14.0 16.3 14.2 14.3 58.7 14 NW-3 320 20.0 10.3 12.3 10.8 12.3 45.5 49 N-l 3 0.6 16.0 17.3 14.8 17.8 65.8 50 N-2 4 2.1 16.0 13.5 16.1 16.3 61.8 51 N-3 358 5.2 12.5 16.3 12.3 15.8 56.8 52 N-4 355 10.0 14.5 14.7 14.3 15.8 59.2 53 NNE-2 31 5.3 13.0 13.0 16.1 11.8 53.8 55 NE-1 38 2.4 14.0 14.0 16.1 14.8 58.8 56 NE-2 51 4.1 10.5 11.5 11.0 12.8 45.8 57 ENE-1 73 0.2 14.0 14.3 11.7 16.3 56.3 58 ENE-2 66 5.1 11.0 15.5 14.5 14.8 55.8 59 E-l 96 1.2 12.0 11.5 12.5 12.8 48.8 60 E-2 87 5.2 15.5 12.5 12.5 14.3 54.8 62 ESE-1 110 1.2 12.5 14.5 11.5 13.3 51.7 63 ESE-2 112 4.9 16.0 17.0 13.5 17.3 63.7 66 SE-1 131 1.4 11.5 10.5 10.0 12.3 44.3 67 SE-2 129 1.9 14.0 16.0 13.0 14.8 57.8 68 SE-4 136 5.2 16.5 18.9 16.1 16.8 68.2 69 SSE-1 154 1.6 13.0 12.5 13.0 N/A 38.5 70 SSE-2 158 4.6 13.5 17.5 15.0 18.9 64.8 71 S-l 183 1.5 16.0 16.5 18.6 18.3 69.3 72 S-2 185 4.7 13.0 11.5 11.0 12.8 48.3 73 SSW-1 203 0.6 14.5 16.8 15.2 17.3 63.7 74 SSW-2 204 4.0 17.5 23.9 19.1 16.3 76.7 75 SW-1 228 0 I 17.0 15.8 16.8 16.8 66.3 76 WSW-1 241 0.9 16.0 17.8 16.3 20.3 70.3 77 WSW-2 238 2.5 9.0 11.0 10.5 11.3 41.8 78 WSW-3 248 5.7 17.0 16.5 15.6 17.8 66.8 79 WSW-4 244 7.8 11.5 13.5 11.5 14.8 51.3 81 W-l 260 0.6 19.5 20.8 18.3 20.3 78.8 82 W-2 275 4.3 10.5 12.3 11.8 14.3 48.8 83 WNW-1 292 0.4 15.5 16.3 17.3 17.3 66.3 84 WNW-2 295 5.3 9.0 10.8 12.8 14.8 47.3 85 NW-1 315 0.4 14.0 14.8 17.3 17.8 63.8 86 NW-2 318 5.2 12.0 12.3 12.3 13.3 49.8 87 NNW-1 344 0.6 19.0 14.3 16.8 15.8 65.8 88 NNW-2 342 1.7 11.0 12.8 11.8 15.3 50.8 89 NNW-3 334 5.3 13.5 15.8 14.3 13.8 57.3 90 SSW-1B 192 1.5 11.0 12.5 12.0 11.8 47.3

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APPENDIX H Table H Weekly Airborne Particulate Gross Beta All Indicator All Control Sample Lower Limit Location with Highest Annual Mean Non-routine Type and Number of Locations Locations Pathway of Detection Reported Analysis Performed Mean (Count) Name, Distance and Mean (Count)

(Measurement Unit) (LLD)a Mean (Range) Measurements Range Direction Range Air Filter 0.033 (415/415) 0.035 (52/52) 0.033 (217/217)

Inhalation Gross Beta 622 0.01 PM-8, 8.7 Mi. SSW 0 (0.014-0.073) (0.014-0.059) (0.016-0.063)

(pCi/m3)

NOTES

a. LLD is the a priori limit as prescribed by the ODCM.

Figure H Average Beta Activity in Air Filters Annua! Average Beta Activity in Air Filters Sequoyah

" ~- ' '?:: ' '#~ *"">* **# -^- ' # M --?

ibH>>~#-**^*"-#-^>>-*~^-H!H<<>>4M>>"*^

m we W: 1990 IM *:>>** 2098 i& im *?};*:'!

[48]

APPENDIX H Table H Weekly Airborne 1-131 Radioativity All Indicator Location with Highest Annual Mean All Control Sample Lower Limit Non-routine Type and Number of Locations Locations Pathwaya of Detection Name, Distance and Reported Analysis Performed Mean (Count) Mean (Count)

(Measurement Unit) (LLD) Mean (Range) Measurements Range Direction Range Activated Charcoal Inhalation 1-131 633 0.07 < LLDa (0/423) <LLD <LLD < LLD (0/210) 0 (pCi/m3)

NOTES

a. The term "< LLD" as used means that results had no identified activity above the minimum detectable.

Table H Quarterly Airborne Composite Particulate Gamma Radioactivity All Indicator Location with Highest Annual Mean All Control Sample Lower Limit Non-routine Type and Number of Locations Locations Pathway of Detection Name, Distance and Reported Analysis Performed Mean (Count) Mean (Count)

(Measurement Unit) (LLD) Mean (Range) Measurements Range Direction Range Air Filter Gamma Inhalation *

• 156 Various < LLDa (0/104) <LLD <LLD < LLD (0/52) 0 Isotopic3 (pCi/m3)

NOTES

a. Natural occurring radionuclides were observed in quarterly composite air samples in 2018.

[49]

APPENDIX H Table H Annual Soil Radioactivity All Indicator All Control Sample Lower Limit Location with Highest Annual Mean Non-routine Type and Number of Locations Locations Pathway of Detection Name, Distance and Reported Analysis Performed Mean (Count) Mean (Range) Mean (Count)

(Measurement Unit) (LLD) Measurements Range Direction Range Gamma Various < LLDa(0/8) <LLD <LLD < LLD (0/4) 0 Isotopic3 Soil 297 (6/8) 580 (1/1) 249 (2/4)

Cs-137 12 180 LM-4,1.5 Mi.,NE 0 Direct Radiation 211-580 580 - 580 82-415 (pCi/g) Sr-89 12 1.6 < LLD (0/8) <LLD <LLD < LLD (0/4) 0 0.117(1/8) 0.117 (1/1)

Sr-90 12 0.4 LM-4, 1.5 Mi.,NE < LLD (0/4) 0 0.117-0.117 0.117-0.117 NOTES

a. Natural occurring radionuclides were observed in soil samples in 2018.

Figure H Average Cs-137 Soil Radioactivity Cs-137 Radioactivity in Soil Sequoyah m

i97o is?s isao tses mo im> 2000 2^5 2020

- #~C0sH!'O; ' A > 1

[50]

APPENDIX H Table H Annual Local Crop Radioactivity Ail Indicator Location with Highest Annual Mean All Control Lower Limit Non-routine Sample Pathway Type and Number of Locations Locations of Detection Name, Distance and Reported (Measurement Unit) Analysis Performed Mean (Count) Mean (Count)

(LLD) Mean (Range) Measurements Range Direction Range Cabbage Ingestion Gamma Variousb < LLD (0/1) <LLD <LLD < LLD (0/2) 0 (pCi/g) Isotopica Corn Ingestion Gamma Various b < LLD (0/2) <LLD <LLD N/A 0 (PCi/g) Isotopic3 Pears Ingestion Gamma Variousb < LLD (0/1) <LLD <LLD N/A 0 (PCi/g) Isotopic 3 Potatoes Ingestion Gamma 1 Various b N/A <LLD <LLD < LLD (0/1) 0 (pCi/g) Isotopic3 Green Beans Gamma Various b < LLD (0/2) <LLD <LLD N/A 0 Ingestion (pCi/g) Isotopic3 Tomatoes Ingestion Gamma 1 Various b < LLD (0/1) <LLD <LLD N/A 0 (pCi/g) Isotopic a NOTES

a. Natural occurring radionuclides were observed in local crop samples in 2018.

b. See Table E-1 through Table E-4 for the required and nominal LLDs for individual radionuclides via gamma isotopic analysis.

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APPENDIX H Table H Monthly Surface Water Radioactivity All Indicator All Control Sample Lower Limit Location with Highest Annual Mean Non-routine Type and Number of Locations Locations Pathway of Detection Reported Analysis Performed Mean (Count) Name, Distance and Mean (Count)

(Measurement Unit) (LLD) Mean (Range) Measurements Range Direction Range Gamma Surface Water 24 Various < LLD (0/13) <LLD <LLD < LLD (0/11) 0 Isotopic3 Direct Exposure 298(2/11) 298 (2/11)

(pCi/L) Tritiumb 15 2000 < LLD (0/4) TRM 483.4 c 0 232 - 363 232 - 363 NOTES

a. Natural occurring radionuclides were observed in surface water samples in 2018.

b. SQN ODCM requires quarterly tritium samples on surface water samples

c. The location with the highest annual mean is a control location.

Table H Monthly Public Drinking Water Radioactivity All Indicator All Control Sample Lower Limit Location with Highest Annual Mean Non-routine Type and Number of Locations Locations Pathway of Detection Reported Analysis Performed Mean (Count)  : Name, Distance and Mean (Count)

(Measurement Unit) (LLD) Mean (Range) Measurements Range Direction Range 3.23(1/13) 3.23 (1/13)

Gross Beta 52 4.0 < LLD (0/39) TRM 503.8 b 0 3.23-3.23 3.23-3.23 Drinking Water Gamma Ingestion Various < LLD3 (0/39) <LLD <LLD < LLD (0/13) 0 Isotopic3 (pCi/L) 302 (3/22) 302 (3/13) 298 (2/11)

Tritium 33 2000 TRM 473 0 266 - 336 266-336 232 - 363 NOTES

a. Natural occurring radionuclides were observed in drinking water samples in 2018.

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APPENDIX H Table H Quarterly Weil (Ground) Water Radioactivity Ail Indicator Location with Highest Annual Mean All Control Sample Lower Limit Non-routine Type and Number of Locations Locations Pathway of Detection Name, Distance and Reported Analysis Performed Mean (Count) Mean (Range) Mean (Count)

(Measurement Unit) (LLD) Measurements Range Direction Range 11.6 (2/2) 11.6 (2/2)

Gross Beta 6 4.0 < LLD (0/4) Farm HW, 1.2 Mi., NWb 0 Ground Water 9.9-13.3 9.9-13.3 Ingestion Gamma Various < LLD3(0/7) <LLD <LLD < LLD (0/2) 0 (pCi/L) Isotopica Tritium 19 2000 < LLD (0/7) <LLD <LLD < LLD (0/2) 0 NOTES

a. Natural occurring radionuclides were observed in ground water samples in 2018.

b. The location with the highest annual mean is a control location Table H Semi-Annual Fish Radioactivity All Indicator Location with Highest Annual Mean All Control Sample Lower Limit Non-routine Type and Number of Locations Locations Pathway of Detection Name, Distance and Reported Analysis Performed Mean (Count) Mean (Count)

(Measurement Unit) (LLD) Mean (Range) Measurements Range Direction Range Game Fish - Large Mouth Bass Gamma 4 Various < LLD3(0/2) <LLD <LLD < LLD (0/2) 0 Ingestion Isotopic a (PCi/kg)

Commercial Fish -

Channel Catfish Gamma 6 Various < LLD (0/4) <LLD <LLD < LLD (0/2) 0 Ingestion Isotopic (pCi/kg)

NOTES

a. Natural occurring radionuclides were observed in fish samples in 2018

[53]

APPENDIX H Table H Semi-Annual Shoreline Sediment Radioactivity All Indicator All Control Sample Lower Limit Location with Highest Annual Mean Non-routine Type and Number of Locations Locations Pathway of Detection Reported Analysis Performed Mean (Count) Name, Distance and Mean (Count)

(Measurement Unit) (LLD) Mean (Range) Measurements Range Direction Range Shoreline Sediment Gamma Direct Radiation 6 Various < LLD3(0/4) <LLD <LLD < LLD(0/2) 0 Isotopic a (PCi/kg)

NOTES

a. Natural occurring radionuclides were observed in shoreline sediment samples in 2018.

[54]

APPENDIX I ERRATA TO PREVIOUS ANNUAL ENVIRONMENTAL OPERATING REPORTS

[55]

APPENDIX I Errata to Previous AREORs There are no identified errors to previous AREORs.

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