ML24120A041

Annual Radioactive Environmental Operating Report for 2023

ML24120A041
Person / Time
Site:	Oyster Creek
Issue date:	04/29/2024
From:	Noval W Holtec Decommissioning International
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
HDI-OC-24-021
Download: ML24120A041 (1)

Text

Krishna P. Singh Technology Campus, 1 Holtec Blvd., Camden, NJ 08104 Telephone (856) 797-0900 Fax (856) 797-0909

10 CFR 50 Appendix I

April 29, 2024

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

Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219

Subject:

Annual Radioactive Environmental Operating Report for 2023

Enclosed with this cover letter is the Annual Radioactive Environmental Operating Report for the calendar year 2023 for the Oyster Creek Nuclear Generating Station. This submittal is made in accordance with the Oyster Creek Nuclear Generating Station s Defueled Safety Analysis Report (DSAR) Appendix B, paragraph B.2.1.b, Annual Radiological Environmental Operating Report.

There are no regulatory commitments in this letter.

Should you have any questions or require further information, please contact Kevin Wolf, Radiation Protection and Chemistry Manager, at (609) 971-4051.

Respectfully,

Digitally signed by William Noval William DN: cn=William Noval, c=US, o=HDI, ou=Regulatory Affairs, email=w.noval@holtec.com Noval Date: 2024.04.29 07:51:00 -04'00'

William Noval Director of Regulatory Affairs Holtec Decommissioning International, LLC

cc:

USNRC Regional Administrator, Region I USNRC Project Manager, NMSS - Oyster Creek Nuclear Generating Station USNRC Region I, Lead Inspector - Oyster Creek Nuclear Generating Station Assistant Commissioner, Air Quality, Energy and Sustainability, NJ DEP Assistant Director Radiation Protection Element, NJ Bureau of Nuclear Engineering

HDI-OC-24-021 Docket No: 50-219

OYSTER CREEK GENERATING STATION UNIT 1

Environmental Operating Report Annual Radiological

1 January through 31 December 2023 Enclosure 1 to HDI-OC-24-021 Prepared By Teledyne Brown Engineering Environmental Services

Oyster Creek Generating Station Forked River, NJ 08731 April 2024

Intentionally left blank

Table of Contents

Preface ................................................................................................................................. 1

I. Summary and Conclusions ............................................................................................ 11

II. Introduction ................................................................................................................... 13 A. Objectives of the REMP .................................................................................... 13 B. Implementation of the Objectives ...................................................................... 13 C. Discussion ......................................................................................................... 14

III. Program Description .................................................................................................... 16 A. Sample Collection.............................................................................................. 16 B. Sample Analysis ................................................................................................ 17 C. Data Interpretation ............................................................................................. 18 D. Program Exceptions .......................................................................................... 19 E. Program Changes ............................................................................................. 20

IV. Program Description .................................................................................................... 21 A. Aquatic Environment ......................................................................................... 21 B. Atmospheric Environment ................................................................................. 24 C. Ambient Gamma Radiation ............................................................................... 25 D. Summary of Results - Inter-laboratory Comparison Program .......................... 26

V. References ................................................................................................................... 28

VI. Errata ........................................................................................................................... 28

i Appendices

Appendix A Radiological Environmental Monitoring Report Summary Tables Table A-1 Radiological Environmental Monitoring Program Annual Summary for the Oyster Creek Generating Station, 2023

Appendix B Location Designation, Distance & Direction, and Sample Collection &

Analytical Methods Tables Table B-1 Location Designation and Identification System for the Oyster Creek Generating Station Table B-2 Radiological Environmental Monitoring Program - Sampling Locations, Distance and Direction, Oyster Creek Generating Station, 2023 Table B-3 Radiological Environmental Monitoring Program - Summary of Sample Collection and Analytical Methods, Oyster Creek Generating Station, 2023 Figures Figure B-1 Locations of REMP Stations within a 1- mile radius of the Oyster Creek Generating Station, 2023 Figure B-2 Locations of REMP Stations within a 1 to 5-mile radius of the Oyster Creek Generating Station, 2023 Figure B-3 Locations of REMP Stations greater than 5 miles from the Oyster Creek Generating Station, 2023

Appendix C Data Tables and Figures - Primary Laboratory Tables Table C-I.1 Concentrations of Tritium in Surface Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-I.2 Concentrations of Gamma Emitters in Surface Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-II.1 Concentrations of Tritium in Drinking Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-II.2 Concentrations of Gross Beta in Drinking Water Samples Collected in the Vicinity of Oyster Creek Generating Stat ion, 2023 Table C-II.3 Concentrations of Gamma Emitters in Drinking Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-III.1 Concentrations of Tritium in Groundwater Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023

ii Table C-III.2 Concentrations of Gamma Emitters in Groundwater Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-IV.1 Concentrations of Gamma Emitters in Predator and Bottom Feeder (Fish) Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-IV.2 Concentrations of Gamma Emitters in Clam and Crab Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-V.1 Concentrations of Gamma Emitters in Sediment Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-VI.1 Concentrations of Gross Beta in Air Particulate Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-VI.2 Monthly and Yearly Mean Values of Gross Beta Concentrations in Air Particulate Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-VI.3 Concentrations of Strontium in Air Particulate Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-VI.4 Concentrations of Gamma Emitters in Air Particulate Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-VII.1 Concentrations of Strontium and Gamma Emitters in Vegetation Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table C-VIII.1 Quarterly OSLD Results for Oyster Creek Generating Station, 2023 Table C-VIII.2 Mean Quarterly OSLD Results for the Site Boundary, Intermediate, Special Interest, and Control Locations for Oyster Creek Generating Station, 2023 Table C-VIII.3 Summary of the Ambient Dosimetry Program for Oyster Creek Generating Station, 2023 Figures Figure C-1 Mean Cobalt-60 Concentration in Clams Oyster Creek Generating Station, 1983 - 2023 Figure C-2 Mean Cobalt-60 Concentration in Aquatic Sediment Oyster Creek Generating Station, 1984 - 2023 Figure C-3 Mean Cesium-137 Concentration in Aquatic Sediment Oyster Creek Generating Station, 1984 - 2023 Figure C-4 Mean Weekly Gross Beta Concentrations in Air Particulates Oyster Creek Generating Station, 2008 - 2023 Figure C-5 Mean Monthly Gross Beta Concentrations in Air Particulates Oyster Creek Generating Station, 1984 - 2023 Figure C-6 Mean Quarterly OSLD Gamma Dose Oyster Creek Generating Station, 2023 iii Appendix D Data Tables - QC Laboratory Tables Table D-I.1 Concentrations of Tritium in Surface Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-I.2 Concentrations of Gamma Emitters in Surface Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-II.1 Concentrations of Tritium in Drinking Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-II.2 Concentrations of Gross Beta in Drinking Water Samples C ollected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-II.3 Concentrations of Gamma Emitters in Drinking Water Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-III.1 Concentrations of Tritium in Groundwater Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-III.2 Concentrations of Gamma Emitters in Groundwater Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023 Table D-IV.1 Concentrations of Gamma Emitters in Clam Samples Collected in the Vicinity of Oyster Creek Generating Stat ion, 2023 Table D-V.1 Concentrations of Gamma Emitters in Sediment Samples Collected in the Vicinity of Oyster Creek Generating Station, 2023

Appendix E Inter-Laboratory Comparison Program Tables Table E-1 Analytics Environmental Radioactivity Cross Check Program Teledyne Brown Engineering, 2023 Table E-2 DOEs Mixed Analyte Performance Evaluation Program (MAPEP)

Teledyne Brown Engineering, 2023 Table E-3 ERA Environmental Radioactivity Cross Check Program Teledyne Brown Engineering, 2023 Table E-4 DOEs Mixed Analyte Performance Evaluation Program (MAPEP),

ATI Environmental, Inc. Midwest Laboratory, 2023 Table E-5 Interlaboratory Comparison Crosscheck Program, Environmental Resource Associates (ERA) RAD Study, ATI Environmental, Inc.

Midwest Laboratory , 2023

Appendix F Errata Data

Appendix G Annual Radiological Groundwater Protection Program Report (ARGPPR) iv Pr e f a c e

The nuclear power industry uses terms and concepts that may be unfamiliar to all readers of this report. This section of the report is intended to help the reader better understand some of these terms and concepts. In this section, we will discuss radiation and exposure pathways. This section is intended only to give a basic understanding of these subjects to hopefully allow the reader to better understand the data provided within the report.

Every nuclear power station is required to submit two reports annually, the Annual Radioactive Effluents Release Report (ARERR) and the Annual Radiological Environmental Operating Report (AREOR). The following information is provided in both reports for Oyster Creek Generating Station.

Un d e r s t a n d i n g Ra d i a t i o n Radiation is simply defined as the process of emitting radiant energy in the form of waves or particles. Radiation can be categorized as ionizing or non- ionizing radiation.

If the radiation has enough energy to displace electrons from an atom it is termed ionizing radiation. Typically you will see a warning sign where there is a potential to be exposed to man- made ionizing radiation. These signs normally have the trefoil symbol on a yellow background.

Example Radiological warning signs

People do not always recognize non- ionizing radiation as a form of radiation, such as light, heat given off from a stove, radiowaves and microwaves. In our report we focus on the ionizing radiation that is produced at a nuclear power plant though it is important to note that ionizing radiation comes from many sources. In fact, the amount of ionizing radiation an average person is exposed to due to operation of a nuclear power plant is a

1 very small fraction of the total ionizing radiation they will be exposed to in their lifetime and will be discussed later.

From this point forward we will only be discussing ionizing radiation but we will just use the term radiation.

Since this report discusses radiation in different forms and different pathways we first need to understand where the radiation comes from that we report. Radiation comes from atoms. So, what are atoms and how does radiation come from atoms?

You may have seen a Periodic Table of the Elements .

This table lists all the elements found on earth. An atom is the smallest part of an element that maintains the characteristics of that element. An atom is made up of three parts, protons, neutrons and electrons.

2 The number of protons in an atom determines the element. A hydrogen atom will always have one proton while an oxygen atom will always have eight protons. The protons are clustered with the neutrons at the center of the atom and this is called the nucleus. Orbiting around the nucleus are the relatively small electrons. Neutrons do not have an electrical charge, protons have a positive charge while electrons have a negative charge. In an electrically neutral atom, the negative and positive charges are balanced. Atoms of the same element that have a different number of neutrons in their nucleus are called isotopes.

Isotopes are atoms that have the same number of protons but different number of neutrons. They all have the same chemical properties and many isotopes are nonradioactive or stable while other isotopes may be unstable and are radioactive.

Radioactive isotopes can be called a radionuclide, a radioisotope or simply called a radioactive atom. A radionuclide usually contains an excess amount of energy in the nucleus usually due to a deficit or excess of neutrons in the nucle us.

There are two basic ways radionuclides are produced at a nuclear power plant. The first way is a direct result of the fission process and the radionuclides created through this process are termed fission products. Fission occurs when a very large atom, such as U-235 (Uranium -235) and Pu-239 (Plutonium -239), absorbs a neutron into its nucleus making the atom unstable. In this instance the atom can actually split into smaller atoms, this splitting of the atom is called fission. When fission occurs the re is also a large amount of energy released from the atom in the form of heat which is what is used to produce the steam that will spin the turbines to produce electricity at a nuclear power plant.

3 The second way a radionuclide is produced at a nuclear power plant is through a process called activation and the radionuclides produced in this method are termed activation products. Water passes through the core where the fission process is occurring. This water is used to both produce the steam to turn the turbines and to cool the reactor. Though the water passing through the core is considered to be very pure water, there is always some other material within the water. This material typically comes from the material used in the plants construction. As the water passes through the core, the material is exposed to the fission process and the radiation within the core can react with the material causing it to become unstable, creating a radionuclide. The atoms in the water itself can become activated and create radionuclides.

Over time, radioactive atoms will reach a stable state and no longer be radioactive. To do this they must release the excess energy. The release of excess energy can be in different forms and is called radioactive decay and the energy released is called radiation. The time it takes for a radionuclide to become stable is measured in units called half-lives. A half-life is the amount of time it takes for half of the original radioactivity to decay. Each radionuclide has a specific half -life. Some half -lives can be very long and are measured in years while others may be very short and are measured in seconds.

In this report, you will see radionuclides listed such as K -40 (potassium-40) and Co- 60 (cobalt-60). The letter(s) represents the element and the number represents the specific isotope of that element and is the number of protons and neutrons in the

4 nucleus of that radionuclide. You may hear the term naturally occurring radionuclide which refers to radionuclides that naturally occur in nature such as K -40. There are man- made radionuclides such as Co- 60 that we are concerned with since these man-made radionuclides result as a by -product when generating electricity at a nuclear power plant. There are other ways man- made radionuclides are produced, such as detonating nuclear weapons, and this is important to note since nuclear weapons testing deposited these man- made radionuclides into the environment and some are still present today. There is a discussion in the AREOR for the radionculides Cs -137, Sr-89 and Sr-90. The reason we only see some of the radionuclides today is due to the fact that some of the radionuclides released into the environment had relatively short half -

lives and all the atoms have decayed to a stable state while other radionuclides have relatively long half -lives and will be measurable in the environment for years to come.

Sources of Radiation People are exposed to radiation every day of their lives and have been since the dawn of mankind. Some of this radiation is naturally occurring while some is man- made.

There are many factors that will determine the amount of radiation an individual will be exposed to such as where you live, medical treatments, etc. Below are examples of some of the typical sources of radiation an individual is exposed to in a year.

Adapted with permission of the National Council on Radiation Protection and Measurements, http://NCRPonline.org

As you can see from the graph, the largest natural source of radiation is due to Radon.

That is because essentially all air contains Radon. Cosmic and Internal make up the

5

next largest natural sources of radiation. Cosmic radiation comes from the sun and stars and there are multiple factors which can impact the amount of cosmic radiation you are exposed to such as the elevation at which you live and the amount of air travel you take a year. The internal natural source of radiation mainly comes from two sources. Technically, all organic material is slightly radioactive due to C -14 (carbon- 14),

including humans and the food we eat. C -14 makes up a percentage of the carbon in all organic material. Another contributor to the internal natural source is K -40 (potassium-40). Potassium is present in many of the foods we eat, such as Brazil nuts, bananas, carrots and red meat. The smallest natural source listed is terrestrial. Soil and rocks contain radioactive materials such as Radium and Uranium. The amount of terrestrial radiation you are exposed to depends on where you live. The map below shows terrestrial exposure levels across the United States. The radiation released from nuclear power plants is included in the Industrial and Occupational slice and is listed as

<0.1%.

Exposure Pathways Radiological exposure pathways define the methods by which people may become exposed to radioactive material. The major pathways of concern are those which could cause the highest calculated radiation dose. These projected pathways are determined from the type and amount of radioactive material released into the environment and how the environment is used. The way radioactive material is transported in the environment includes consideration of physical factor s, such as the hydrological (water) and meteorological (weather) characteristics of the area. An annual average of the water flow, wind speed, and wind direction are used to evaluate how the radionuclides will be

6 distributed in an area for gaseous or liquid releases. An important factor in evaluating the exposure pathways is the use of the environment. Many factors are considered such as dietary intake of residents, recreational use of the area, and the locations of homes and farms in the area.

The external and internal exposure pathways considered are shown in Figure 2.1. The release of radioactive gaseous effluents involves pathways such as external whole-body exposure, deposition of radioactive material on plants, deposition on soil, inhalation by animals destined for human consumption, and inhalation by humans. The release of radioactive material in liquid effluents involves pathways such as drinking water, fish, and direct exposure from the water at the shoreline while swimming.

Although radionuclides can reach humans by many different pathways, some result in more dose than others. The critical pathway is the exposure route that will provide, for a specific radionuclide, the greatest dose to a population, or to a specific group of the population called the critical group. The critical group may vary depending on the radionuclides involved, the age and diet of the group, or other cultural factors. The dose may be delivered to the whole body or to a specific organ. The organ receiving the greatest fraction of the dose is called the critical organ.

Figure 2.1 External and Internal Exposure Pathways

This simple diagram demonstrates some potential exposure pathways from Oyster Creek Generating Station.

7 Ra d i a t i o n Ri s k U.S. radiation protection standards are based on the premise that any radiation exposure carries some risk. There is a risk whether the radiation exposure is due to man- made sources or natural sources. There have been many studies performed trying to determine the level of risk. The following graph is an example of one study that tries to relate risk from many different factors. This graph represents risk as Days of Lost Life Expectancy. All the categories are averaged over the entire population except Male Smokers, Female Smokers and individuals that are overweight. Those risks are only for people that fall into those categories. The category for Nuclear Power is a government estimate based on all radioactivity releases from nuclear power, including accidents and wastes.

Adapted from th e article b y B ernard L. C oh en, Ph . D. in th e J ournal of Am erican Ph ysicians and Surgeons V olum e 8 N um b er 2 Sum m er 2 003. T h e full article can b e found at h ttp: / / w w w . j pands. org/ vol8 no2 / coh en. pdf

8 Annual Reports All nuclear power plants are required to perform sampling of both the potential release paths from the plant and the potential exposure pathways in the environment. The results of this sampling are required to be reported annually to the Nuclear Regulator y Commission (NRC) and made available to the public. There are two reports generated annually, the Annual Radioactive Effluents Release Report (ARERR) and the Annual Radiological Environmental Operating Report (AREOR). The ARERR summarizes all of the effluents released from the plant and quantifies the doses to the public from these effluents. The AREOR summarizes the results of the samples obtained in the environment looking at all the potential exposure pathways by sampling different media such as air, vegetation, direct radiation, etc. These two reports are related in that the results should be aligned. The AREOR should validate that the effluent program is accurate. The ARERR and AREOR together ensure Nuclear Power Plants are operating in a manner that adequately protects the public and the environment.

In the reports, there are four different but interrelated units for measuring radioactivity, exposure to radioactivity, absorbed dose, and dose equivalent. Together, they are used to properly capture both the amount of radiation and its effects on humans.

• Radioactivity refers to the amount of ionizing radiation released by a material.

The units of measure for radioactivity used within the AREOR and ARERR are the curie (Ci). Small fractions of the Ci often have a prefix, such as microCurie (Ci) that means 1/1,000,000. That means there are 1,000,000 Ci in one Ci.

Due to the extremely low levels of radioactivity in the environment, the unit commonly used for these samples is the picocurie (pCi). A pCi is 1/1,000,000 of a µCi; there are 1,000,000 pCi in a µCi. There are 1,000,000,000,000 pCi in a Ci.

• Exposure describes the amount of radiation traveling through the air. The units of measure for exposure used within the AREOR and ARERR are the roentgen (R). Traditionally direct radiation monitors placed around the site are measured in milliroentgen (mR), 1/1,000 of one R.

• Absorbed dose describes the amount of radiation absorbed by an object or person. The units of measure for absorbed dose used within the AREOR and ARERR are the rad. Noble gas air doses, when reported by the site, are measured in millirad (mrad), 1/1,000 of one rad.

• Dose equivalent (or effective dose) combines the amount of radiation absorbed and the health effects of that type of radiation. The units used within the AREOR and ARERR are the roentgen equivalent man (rem). Regulations require doses to the whole body, specific organ, and direct radiation to be reported in millirem (mrem), 1/1,000 of one rem.

9 Typically releases from nuclear power plants are so low that the samples taken in the environment are below the detection levels required to be met by all nuclear power plants. There are some radionuclides identified in the environment during the routine sampling, but this is typically background radiation from nuclear weapons testing and events such as Chernobyl and these radionuclides are discussed in the AREOR.

Each report lists the types of samples that are collected and the analyses performed.

Different types of media may be used at one sample location looking for specific radionuclides. There are also examples where a sample collected on one media is analyzed differently depending on the radionuclide for which the sample is being analyzed.

These annual reports, and much more information related to nuclear power, are available on the NRC website at www.nrc.gov.

10 I. Summary and Conclusions On July 1st, 2019, ownership of the Oyster Creek Nuclear Power Station and transfer of the station and decommissioning license from Exelon Generation Company, LLC to Oyster Creek Environmental Protection, LLC (OCEP) as the licensed owner and Holtec Decommissioning International, LLC (HDI) as the licensed operator, was completed. Exelon had determined that transitioning operational nuclear plants to decommissioning nuclear plants targeted for permanent shutdown was not aligned with its core objectives and actively sought buyers who would assume ownership and complete decommissioning and license termination.

This report on the Radiological Environmental Monitoring Program (REMP) conducted for the Oyster Creek Generating Station (OCGS) by Holtec Decommissioning International, LLC (HDI) covers the period 01 J anuary 2023 through 31 December 2023. During that time period, a total of 803 analyses were performed on 645 samples. In assessing all the data gathered for this report and comparing these results with historical data, it was concluded that the decommissioning of OCGS had no adverse radiological impact on the environment.

REMP-designated surface water samples were analyzed for concentrations of tritium and gamma emitting nuclides. No tritium, fission or activation products were detected in any of the surface water samples collected as part of the Radiological Environmental Monitoring Program during 2023.

REMP-designated drinking water samples were analyzed for concentrations of gross beta, tritium, and gamma emitting nuclides. The preoperational environmental monitoring program did not include analysis of drinking water for gross beta. No tritium or fission or activation products were detected in any of the drinking water samples collected.

REMP-designated groundwater samples were analyzed for concentrations of tritium and gamma emitting nuclides. No tritium and no fission or activation products were detected in REMP groundwater samples.

Fish (predator), clams, crabs, and sediment samples were analyzed for concentrations of gamma emitting nuclides. No OCGS -produced fission or activation products were detected in fish, clams, crabs or sediment samples.

Air particulate samples were analyzed for concentrations of gross beta, gamma emitting nuclides, and strontium -90 (Sr-90). Gross beta and cosmogenic beryllium-7 (Be-7) were detected at levels consistent with those detected in previous years. No fission or activation products were detected.

Sr-90 analysis was performed on quarterly composites of air particulate samples and all results were below the Minimum Detection Concentration (MDC).

Environmental gamma radiation measurements were performed quarterly using Optically Stimulated Luminescence Dosimeters (OSLD). Beginning in calendar year 2012, Exelon (the previous plant owner) began using OSLDs and

11 discontinued the use of Thermoluminescent Dosimetry (TLD). There were two main reasons for this change. First, OSLDs have minimal fade over a quarterly time period. Fade is where the dose on the dosimeter drifts lower over time.

Second, OSLDs may be re- read if necessary. TLDs are reset to zero after they are read. Levels detected were consistent with those observed in previous years. The maximum dose to any member of the public attributable to radioactive effluents and direct radiation from the OCGS was less than the 25 mRem/year limit established by the United States Environmental Protection Agency (EPA ).

12 II. Introduction The Oyster Creek Generating Station (OCGS) is a non- operational single unit nuclear power plant owned and operated by HDI. OCGS is located on the Atlantic Coastal Plain Physiographic Province in Ocean County, New Jersey, about 60 miles south of Newark, 9 miles south of Toms River, and 35 miles north of Atlantic City. It lies approximately 2 miles inland from the Barnegat Bay. The Oyster Creek Site is approximately 152 acres located west of U.S. Highway Route 9 between the south branch of the Forked River and the Oyster Creek. Most of the Site is identified as Block 100, Lot 4.02 in Lacey Township according to a 2018 American Land Title Association (ALTA)/National Society of Professional Surveyors (NSPS) land title survey. The site includes a small land area south of the Discharge Canal identified as Block 4, Lot 43 in Ocean Township. A perimeter security fence surrounds the restricted /protected area of the site. The site description is changed to reflect the current decommissioning site boundaries.

The site location is part of the New Jersey shore area with its relatively flat topography and extensive freshwater and saltwater marshlands. The South Branch of Forked River runs across the northern side of the site and Oyster Creek partly borders the southern side.

A preoperational Radiological Environmental Monitoring Program (REMP) for OCGS was established in 1966 and continued prior to the plant becoming operational in 1969. This report covers those analyses performed by Teledyne Brown Engineering (TBE), Landauer and Microbac Laboratories Inc. on samples collected during the period 01 January 2023 through 31 December 2023.

A. Objectives of the REMP The objectives of the REMP are to:

1. Provide data on measurable levels of radiation and radioactive materials in and beyond the site environs

2. Evaluate the relationship between quantities of radioactive material released from the plant and resultant radiation doses to individuals from principal pathways of exposure

3. Validate the effluent computer model that predicts radioactive material concentrations at populated off -site locations

4. Fulfill the obligations of the radiological surveillance sections of Oyster Creeks Offsite Dose Calculation Manual (ODCM)

B. Implementation of the Object ives The implementation of the objectives is accomplished by:

1. Identifying significant exposure pathways

2. Establishing baseline radiological data for media within those pathways

3. Continuously monitoring those m edia before, during and after terminating Station operation to assess Station radiological effects (if any) on the public, plant workers and the environment 13 C. Discussion

1. General Program The Radiological Environmental Monitoring Program (REMP) was established in 1966, before the plant became operational. This preoperational surveillance program was established to describe and quantify the radioactivity, and its variability, in the area prior to the operation of OCGS. After OCGS became operational in 1969, the operational surveillance program continued to measure radiation and radioactivity in the surrounding areas.

A variety of environmental samples are collected as part of the REMP at OCGS. The selection of sample types is based on the established pathways for the transfer of radionuclides through the environment to humans. The selection of sampling locations is based on sample availability, local meteorological and hydrological characteristics, local population characteristics, and land usage in the area of interest. The selection of sampling frequencies for the various environmental media is based on the radionuclides of interest, their respective half -lives, and their behavior in both the biological and physical environment.

2. Preoperational Surveillance Program The federal government requires nuclear facilities to conduct radiological environmental monitoring prior to constructing the facility. This preoperational surveillance program is aimed at c ollecting the data needed to identify pathways, including selection of the radioisotope and sample media combinations to be included in the environmental surveillance program conducted after facility operation begins.

Radiochemical analyses performed on the environmental samples should include not only those nuclides expected to be released during facility operation but should also include typical radionuclides from nuclear weapons testing and natural background radioactivity. All environmental media with a potential to be affected by facility operation as well as those media directly in the major pathways, should be sampled on at least an annual basis during the preoperational phase of the environmental surveillance program.

The preoperational surveillance design, including nuclide/media combinations, sampling frequencies and locations, collection techniques, and radioanalyses performed, should be carefully considered and incorporated in the design of the operational surveillance program. In this manner, data can be compared in a variety of ways (for example, from year to year, location to location, etc.) in order to detect any radiological impact the facility has on the surrounding environment. Data collection during the preoperational phase should be planned to provide a comprehensive database for evaluating any future changes in the environment surrounding the nuclear facility.

14 OCGS began its preoperational environmental surveillance program three years before the plant began operating in 1969. Data acc umulated during those early years provide an extensive database from which environmental monitoring personnel are able to identify trends in the radiological characteristics of the local environment. The environmental surveillance program at OCGS will continue after the plant has reached the end of its economically useful life and decommissioning has begun.

3. Consideration of Plant Effluents Effluents are strictly monitored to ensure that radioactivity released to the environment is as low as reasonably achievable (ALARA) and does not exceed regulatory limits. Effluent control includes the operation of monitoring systems, in-plant and environmental sampling and analyses programs, quality assurance programs for effluent and environmental programs, and proc edures covering all aspects of effluent and environmental monitoring.

Both radiological environmental and effluent monitoring indicate that the operation of OCGS does not result in significant radiation exposure of the people or the environment surrounding OCGS and is well below the applicable levels set by the Nuclear Regulatory Commission (NRC) and the Environmental Protection Agency (EPA).

Environmental sampling of airborne particulates showed no radioactivity attributable to the operation of OCGS .

15 III. Program Description

A. Sample Collection Samples for the OCGS REMP were collected for HDI by on- site personnel and Normandeau Associates, Incorporated. This section describes the general collection methods used to obtain environmental samples for the OCGS REMP in 2023. Sample locations and descriptions can be found in Tables B-1 and B-2, and Figures B -1, B-2, and B -3, Appendix B. The collection procedures are listed in Table B -3.

Aquatic Environment The aquatic environment was evaluated by performing radiological analyses on samples of surface water, drinking water, groundwater, fish, clams, crabs and sediment. One gallon water samples were collected monthly from two surface water locations (33 and 94), semiannually at two surface water locations (23 and 24), monthly from four drinking water wells (1N, 1S, 37 and

38) and quarterly from 2 groundwater stations (MW 3A and W -3C).

Control locations were 94 and 37. All samples were collected in plastic bottles, which were rinsed at least twice with source water prior to collection.

Fish samples comprised of the flesh of predators and bottom feeders were collected semiannually at two locations (33 and 93) and annually at control location 94. Clams were collected semiannually from three locations (23, 24, and 94 [control]). Two annual crab samples were collected from two locations (33 and 93). Sediment samples were collected at four locations semiannually (23, 24, 33, and 94 [control]).

Atmospheric Environment The atmospheric environment was evaluated by performing radiological analyses on air particulate samples. Air particulate samples were collected and analyzed bi -weekly at seven locations (C, 20, 66, 71, 72, 73, and 111).

The control location was C. The samples were obtained at each location, using a vacuum pump with glass fiber filters attached. The pumps were run continuously and sampled air at the rate of approximately one cubic foot per minute. The filters were replaced weekly and sent to the laboratory for analysis.

Terrestrial Environment The latest revision to the Offsite Dose Calculation Manual (ODCM) released in December 2022 removed vegetable samples from the program. These samples are of primary use to monitor radioactive I -131 uptake from plant releases. This radioisotope has a short half -life of 8.3 days and has decayed away completely. Therefore the analysis of vegetables has no value in monitoring for this uptake any longer.

16 Ambient Gamma Radiation Direct radiation measurements were made using Al 2O3:C Optically Stimulated Luminescence Dosimetry (OSLD). Exelon Nuclear (the previous plant owner) changed the dosimetry used for environmental monitoring. Beginning in calendar year 2012, Exelon began using OSLDs and discontinued the use of Thermoluminescent Dosimetry (TLD). There were two main reasons for this change. First, OS LDs are subject to minimal fade. Fade is where the dose on the dosimeter drifts lower over time. Second, OSLDs may be re- read if necessary. TLDs are reset to zero after they are read. The OSLDs were placed on and around the OCGS site and were categorized as follows:

An inner ring consisting of 19 locations (1, T1, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 112 and 113) near the site boundary.

An outer ring consisting of 21 locations (6, 8, 9, 22, 68, 73, 74, 75, 78, 79, 98, 99, 100, 101, 102, 103, 104, 106, 107, 109 and 110) extending to approximately 5 miles from the site designed to measure possible exposures to close-in population.

Special interest stations consisting of 3 locations (71, 72 and 81) representing special interest areas such as population centers, state parks, etc.

Background (Control) stations consisting of one location (C) greater than 20 miles distant from the site.

Indicator OSLDs were placed systematically, with at least one station in each of 16 meteorological compass sectors in the general area of the site boundary. OSLDs were also placed in each meteorological sector in the 1 to 5 mile range, where reasonable highway access would permit, in areas of public interest and population centers. Background locations were located greater than twenty miles distant from the OCGS and generally in an upwind direction from the OCGS.

Two OSLDs were placed at each location approximately three to eight feet above ground level. The OSLDs were exchanged quarterly and sent to a vendor for analysis.

B. Sample Analysis This section describes the general analytical methodologies used by TBE and Microbac Laboratories Inc. to analyze the environmental samples for radioactivity for the OCGS REMP in 2023. The analytical procedures used by the laboratories are listed in Table B -3.

In order to achieve the stated objectives, the current program includes the following analyses:

1. Concentrations of beta emitters in air particulates and drinking water

17

2. Concentrations of gamma emitters in surface water, drinking water, groundwater, fish, clams, crabs, sediment and air particulates

3. Concentrations of tritium in REMP -designated surface water, drinking water and groundwater

4. Concentrations of strontium in air particulates

C. Data Interpretation For trending purposes, the radiological and direct radiation data collected during 2023 were compared with data from past years. The results of environmental sampling show that radioactivity levels have not increased from the background radioactivity detected prior to the operation of OCGS. The operation of OCGS continues to have no measurable radiological impact upon the environment.

Several factors were important in the interpretation of the data:

1. Lower Limit of Detection and Minimum Detectable Concentration The lower limit of detection (LLD) is defined as the smallest concentration of radioactive material in a sample that would yield a net count (above background) that would be detected with only a 5% probability of falsely concluding that a blank observation represents a "real" signal. The LLD is intended as a before the fact ( a priori) estimate of a system (including instrumentation, procedure and sample type) and not as an after the fact (a posteriori) criterion for the presence of activity. All analyses were designed to achieve the required OCGS detection capabilities for environmental sample analysis.

The minimum detectable concentration (MDC) is defined above with the exception that the measurement is an after the fact estimate of the presence of activity.

2. Net Activity Calculation and Reporting of Results Net activity for a sample was calculated by subtracting background activity from the sample activity. Since the REMP measures extremely small changes in radioactivity in the environment, background variations may result in sample activity being lower than the background activity, which results in a negative number. A less -than MDC was reported in all cases where positive activity was not detected.

Gamma spectroscopy results for each type of sample were grouped as follows:

For surface, drinking water, and groundwater - five nuclides:

Mn-54, Co- 60, Zn-65, Cs-134 and Cs-137 were reported.

For fish - six nuclides: K-40, Mn- 54, Co-60, Zn-65, Cs-134 and Cs-137 were reported.

18 For clams - six nuclides: K-40, Mn- 54, Co- 60, Zn- 65, Cs-134 and Cs-137 were reported.

For crabs - six nuclides: K-40, Mn- 54, Co- 60, Zn- 65, Cs-134 and Cs-137 were reported.

For sediment - eight nuclides: Be- 7, K-40, Mn- 54, Co- 60, Cs-134, Cs-137, Ra- 226 and Th- 228 were reported.

For air particulates - five nuclides: Be- 7, Mn-54, Co-60, Cs-134 and Cs-137 were reported.

Means and standard deviations of the results were calculated. The standard deviations represent the variability of measured results for different samples rather than single analysis uncertainty.

D. Program Exceptions For 2023, the OCGS REMP had a sample recovery rate in excess of 97%.

Exceptions are listed below:

Environmental Dosimetry

1. 10/0 4/23: TLD-113 - Q3 TLD missing from pole on Route 9. The pole has been replaced and new TLD hanger installed (OYS -03530).

Air

1. 03/07/23: Station 20 - Pump was replaced due to vow vacuum reading.

When the new pump was plugged in and powered on, a fuse blew. The 8-amp fuse inside the station was replaced with no effect and repair completed ( OYS-03258).

2. 03/07/23: Station 111 - During the bi -weekly filter exchange of the REMP samples, the timer was found with no display. Calculated sample time from last date/time and replaced timer. No sample lost (OYS-03210).

3. 03/2 1/23: Station 20 - During the bi-weekly sample collection, the p ump was found not running. The GFCI reset button was pushed with no power restored. Electrical support restored station function (OYS-03232).

4. 04/ 04/23: S tation 73 - Pump running but no vacuum measur able.

Replaced pump with spare. As left reading was SAT. Filter indicated sufficient sample was collected for analysis. No sample lost. Replaced vanes on pump (OYS-03258).

5. 08/21/23: Station 66 - Pump was not running when sample collection was made. Filter was light color, indicating less dust loading than normal. Sample was sent for analysis and gross result was significantly lower than other samples. No further analysis will be performed. Pump replaced (OY -03493).

19

6. 09/06/23: Station 66 - Pump failed; no sample collected. Replaced with spare pump, as left readings were SAT (OYS -03497).

7. 09/06/23: Station 71 - Vacuum pump reading less than minimum.

Replaced with pump with spare. As left vacuum reading was SAT.

Sample loading adequate for analysis, no sample lost (OYS-03498).

8. 10/31/23: Station 66 - Discrepancy in sample run time of 31.62 hours7.175926e-4 days <br />0.0172 hours <br />1.025132e-4 weeks <br />2.3591e-5 months <br /> recorded for this station. Sample was SAT for analysis, no lost sample.

Power may have been out over the weekend due to storms in the area (OYS-03566).

9. 11/14/23: Station C - Pump vacuum reading less than minimum.

Replaced pump with spare. As left vacuu m reading was SAT. Sample loading adequate for analysis - no sample lost (OYS-03586).

10. 11/28/23: Station 73 - GFCI tripped by high wind- driven rain. Reset GFCI and sent sample for analysis (OYS-03607).

11. 12/13/23: Station 111 - Pump failed. Replaced with spare pump - as left readings were SAT. Sample loading adequate for analysis, no sample lost. (OYS-03640).

12. 12/13/23: Station 71 - pump vacuum reading less than minimum.

Replaced with spare. As left vacuum reading was SAT. Sample loading adequate for analysis, no sample lost (OYS -03641).

Drinking Water Note: Stations 1S and 1N are on- site drinking water wells. Typically, only one well is in service at a time. They are only listed as deviations when there is not a sample for the monitoring period.

2023: Station 1S was not operational for the entire year.

Program exceptions are tracked by Oyster Creek staff and Normandeau and investigated to understand the causes of the program exception. Sampling and maintenance errors are reviewed with the personnel involved to prevent recurrence.

The overall sample recovery rate indicates that the appropriate procedures and equipment are in place to assure reliable program implementation.

E. Program Changes Station 72, vegetation, and Land Use Census were removed from the ODCM in Rev. 13 (December 2022) and included in the ARERR for 2022.

There were no additional changes made in 2023.

20 IV. Results and Discussion A. Aquatic Environment

1. Surface Water Samples were taken via grab sample methodology at two locations (33 and 94) on a monthly schedule. In addition, grab samples were collected semi-annually at two locations (23 and 24). Of these locations 23, 24 and 33, located downstream, could be affected by Oyster C reeks effluent releases. The following analyses were performed:

Tritium Surface water sampling began in 1966, and the samples were analyzed for tritium as well as other radioactivity. During this preoperational program, tritium was detected at an averag e concentration of 1,050 pCi/L.

At that time, counting instrumentation was not as sensitive as it now, and the minimum detectable concentration (MDC) was 1,000 pCi/L.

Instrument improvements lowered the detection range to 200 pCi/L which was used to monitor tritium in ground water as a result of process leaks.

The MDC was changed to 2,000 pCi/L in November 2020 to reflect the reduction of risk since the plant has started actively decommissioning.

By comparing the 2023 sampling results to the decay - corrected average preoperational concentration reported in the 2007 Annual Radiological Environmental Operating Report (111 pCi/L), it can be seen that the inventory of tritium in the environment is due to fallout from past atmospheric nuclear weapons testing and is decreasing with time.

Samples from all locations were analyzed for tritium activity. No tritium activity was detected. (Table C -I.1, Appendix C)

Gamma Spectrometry Samples from all locations were analyzed for gamma emitting nuclides.

All nuclides were less than the MDC. (Table C -I.2, Appendix C)

2. Drinking water Monthly grab samples were taken from three drinking water wells (1N, 37 and 38). Station 1, because it is located on the OCGS site, could potentially be affected by radioactive releases from the plant. Station 1 was split into two separate locations, 1N and 1S. Station 38, the Ocean Township Municipal Utility Authority Well, could potentially be affected by effluent releases from the OCGS. Given its distance from the facility (1.6 miles) and depth (approximately 360 feet), however, the probability of any OCGS-related impact is very small. Stations 37, a Lacey Township Municipal Utility Authority well, is not likely to be impacted by effluents from the OCGS. This well is located generally up- gradient of the regional groundwater flow direction (southeast). In addition, because of the depth

21

(> 200 feet) and distance from the site (2.2 miles), it is unlikely to b e affected by OCGS operations.

The following analyses were performed:

Tritium Monthly samples from all locations were analyzed for tritium activity. No tritium activity was detected. Drinking water was sampled during the preoperational program and throughout the almost 50 years of the plants operational program. Tritium sampling results during the preoperational years, yielded results all less than the minimum detectable concentration of 1000 pCi/L. The 2023 results are all less than the MDC.

(Table C-II.1, Appendix C)

Gross Beta Monthly samples from all locations were analyzed for concentrations of total gross beta activity. Gross beta was detected in 20 of 36 samples and is attributed to natural sources and fallout residual from previous bomb testing. The values ranged from 1. 9 to 4.0 pCi/L.

(Table C-II.2, Appendix C)

Gamma Spectrometry Samples from all locations were analyzed for gamma emitting nuclides.

All nuclides were less than the MDC. (Table C -II.3, Appendix C)

3. Groundwater The following analyses were performed:

Tritium Samples from all locations were analyzed for tritium activity. No tritium activity was detected. (Table C -III.1, Appendix C)

Gamma Spectrometry Samples from all locations were analyzed for gamma emitting nuclides (Table C-III.2, Appendix C). All nuclides were less than the MDC.

4. Fish Fish samples comprised of predators (American eel , striped bass, white perch, bluefish, tautog, Atlantic herring and chain pickerel ) were collected at two locations (33 and 93) semiannually when available. These locations could be affected by Oyster Creeks effluent releases. The following analysis was performed:

Gamma Spectrometry The edible portions of fish samples from three locations were analyzed for gamma emitting nuclides. Naturally occurring K -40 was detected in 1 6 of

22 16 samples and ranged from 2,368 to 5,312 pCi/kg wet and was consistent with levels detected in previous years. No fission or activation products were found. (Table C -IV.1, Appendix C)

No fish were sampled during the preoperational sampling program for OCGS.

5. Clams and Crabs Clams were collected at three locations (23, 24, and 94) semiannually when available. Crabs were collected at one location (33) annually when available. Locations 23, 24, 33, and 93 could be affected by Oyster Creeks effluent releases. The following analysis was performed:

Gamma Spectrometry The edible portions of clam samples from all three locations were analyzed for gamma emitting nuclides. Naturally occurring K -40 was found at all stations and ranged from 1,530 to 2,986 pCi/kg wet and was consistent with levels detected in previous years. No fission or activation products were found. (Table C -IV.2, Appendix C) Historical levels of Co-60 in clams are shown in Figure C -1, Appendix C. After 1986, all results met the required Lower Limit of Detection (LLD) and were less than the Minimum Detectable Concentration (MDC) .

Preoperational clam sample results for naturally occurring K -40 ranged from 600 to 9,800 pCi/kg wet, which are consistent with current sample results.

The edible portions of an annual crab sample were analyzed for gamma emitting nuclides. Naturally occurring K -40 was found at a concentration of 2 ,874 pCi/kg wet, consistent with levels detected in previous years. No fission or activation products were found. (Table C-IV.2, Appendix C)

Crabs were not sampled during the preoperational years of the OCGS environmental monitoring program.

6. Sediment Aquatic sediment samples were collected at four locations (23, 24, 33, and 94) semiannually. Of these locations, stations 23, 24, and 33 located downstream, could be affected by Oyster Creeks effluent releases. The following analysis was performed:

Gamma Spectrometry Sediment samples from all four locations were analyzed for gamma emitting nuclides. Naturally occurring K -40 was detected in 10 of 10 samples ranged from 1,152 to 16,420 pCi/kg dry. Naturally occurring Th-228 was found at all 4 stations and ranged from 172 to 890 pCi/kg wet.

Cs-137 was not detected in any of the samples. No fission or activation products were found. (Table C-V.1, Appendix C)

23 The Figure C-3, Appendix C graph shows Cs -137 concentrations in sediment from 1984 through 2023 and Figure C-2, Appendix C graph shows Co-60 concentrations in sediment from 1984 through 2023.

The requirement for sampling sediment is a requirement of ODCM 3.12.1, Table 3.12.1- 1.d. ODCM Table 3.12.1- 2, Reporting Levels for Radioactive Concentrations in Environmental Samples Reporting Levels does not include requirements for sediment. CY -AA- 170- 1000, Radiological Environmental Monitoring Program and Meteorological Program Implementation, Attachment 1, Analytical Results Investigation Levels, includes sediment investigation level for Cs -137 of 1000E+00 pCi/kg dry.

While aquatic sediment sampling was part of the preoperational program, samples were not analyzed for gamma emitting nuclides until 1981.

In conclusion, the 2023 aquatic monitoring results for surface water, drinking water, groundwater, fish, clams, crabs, and sediment showed only naturally occurring radioactivity and were consistent with levels measured prior to the operation of OCGS, and with levels measured in past years. No radioactivity attributable to activities at OCGS was detected in any aquatic samples during 2023 and no adverse long- term trends are shown in the aquatic monitoring data.

B. Atmospheric Environment Airborne (Air Particulates)

Continuous air particulate samples were collected from s ix locations on a bi-weekly basis. The six locations were separated into three groups: Group I represents locations near the OCGS site boundary (20, 66 and 111), Group II represents the locations at an intermediate distance from the OCGS site (71 and 73), and Group III represents the control and locations at a remote distance from OCGS (C). The following analyses were performed:

Gross Beta Samples were analyzed for concentrations of beta emitters. Detectable gross beta activity was observed at all locations. Comparison of results among the three groups aids in determining the effects, if any, resulting from the operation of OCGS. The results from the Site Boundary locations (Group I) ranged from 4E-03 to 26E- 03 pCi/m3 with a mean of 16E- 03 pCi/m3. The results from the Intermediate Distance locations (Group II) ranged from 4E-03 to 26E-03 pCi/m3 with a mean of 16E- 03 pCi/m3. The results from the Distant locations (Group III) ranged from 9E-03 to 26E- 03 pCi/m3 with a mean of 16E- 03 pCi/m3. (Table C-VI.1 and C-VI.2, Appendix C)

The similarity of the results from the three groups indicates that there is no relationship between gross beta activity and distance from OCGS. These results are consistent with data from previous years and indicate no effects from the operation of OCGS. (Figures C -4 and C-5, Appendix C).

24 Air sample filters have been analyzed for gross beta activity since the inception of the preoperational environmental monitoring program in 1966. The preoperational data values ranged from 1.90E -02 to 2.77E -01 pCi/m3. The 2023 gross beta activity values ranged from <3E -03 to 29E- 03 pCi/m3. The 2023 results are consis tent with historical operational data (Figure C -5, Appendix C) and fall within the range of results observed during the preoperational period.

Strontium-90 Samples were composited quarterly and analyzed for Sr -90. No strontium was detected in any of the samples. (Table C -VI.3, Appendix C) These results are consistent with historical operational data. The preoperational environmental monitoring program did not include analysis of air samples for Sr -90.

Gamma Spectrometry Samples were composited quarterly and analyzed for gamma emitting nuclides. Naturally occurring Be- 7 due to cosmic ray activity was detected in 24 of 24 samples. The values ranged from 37E-03 to 96E-03 pCi/m3. All other nuclides were less than the MDC. (Table C-VI.4, Appendix C) These results are consistent with historical operational data. The preoperational environmental monitoring program did not include analysis of air samples for gamma emitting nuclides.

C. Ambient Gamma Radiation Ambient gamma radiation levels were measured using Optically Stimulated Luminescence Dosimeters (OSLD). Forty -four OSLD locations were monitored around the site with all measurements below 29 mRem/yr. Results of background corrected OSLD measurements are summarized in Tables C-IX.1 to C-IX.3 and Figure C -6.

The non- background corrected OSLD measurements ranged from 15.1 to 26.9 mR/standard quarter. In order to correct these results for background radiation, the mean of the dose rates measured at the back ground OSLD station (C) was subtracted from the dose measured at each indicator station.

The preoperational environmental monitoring program utilized film badges, the results of which are not comparable with the doses measured using thermoluminescent dosim eters or optically stimulated dosimeters during the operational REMP. In conclusion, the 2023 OSLD results are consistent with past operational measurements of direct radiation and demonstrate that the OCGS continues to be in compliance with the 40 CFR 190 limit on maximum dose to the public.

25 D. Summary of Results - Inter-laboratory Comparison Program The TBE Laboratory analyzed Performance Evaluation (PE) samples of air particulate, air iodine, milk, soil, vegetation, and water matrices that represent

test & matrix combinations available for REMP programs. The PE samples supplied by Analytics Inc., Environmental Resource Associates (ERA) and Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP), were evaluated against the following pre- set acceptance criteria:

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

B. ERA Evaluation Criteria ERAs evaluation report provides an acceptance range for control and warning limits with associated flag values. ERAs acceptance limits are established per the United States Environmental Protection Agency (USEPA), National Environmental Laboratory Accreditation Conference (NELAC), state-specific Performance Testing (PT) program requirements or ERAs standard operating procedure (SOP) for the Generation of Performance Acceptance Limits, as applicable. The acceptance limits are either determined by a regression equation specific to each analyte or a fixed percentage limit promulgated under the appropriate regulatory document.

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

• Acceptable (flag = A) - result within +/- 20% of the reference value

• Acceptable with Warning (flag = W) - result falls in the +/- 20% to +/-

30% of the reference value

• Not Acceptable (flag = N) - bias is greater than 30% of the reference value Note: The Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP) samples are created to mimic conditions found at DOE sites which do not resemble typical environmental samples obtained at commercial nuclear power facilities.

For the TBE laboratory, 124 out of 131 analyses performed met the specified acceptance criteria. Seven analyses did not meet the specified acceptance criteria and were addressed through the TBE Corrective Action Program. A summary is found below  :

26

1. The MAPEP February 2023 Soil Ni -63 result was evaluated as Not Acceptable. TBEs reported value was 294 Bq/kg and the known result was 1130 Bq/kg (range 791 - 1469). The sample was reprepped by a different (senior) lab technician with results of 1120 & 1250 Bq. It was determined that there was a difference between the two techs during the sample prep (technique) and the procedure was revised to reflect these differences including using a specific aliquot amount. (NCR 23- 08)

2. The MAPEP February 2023 vegetation Sr -90 result was evaluated as Not Acceptable. The reported value was 0.05 Bq (not detected) and the known result was a false positive. This was considered to be a statistical failure because TBEs reported result with 3 times the uncertainty resulted in a slightly positive net result (0.03194 Bq/kg). The reported result was significantly below TBEs average detection limit for vegetation samples.

(NCR 23-09)

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

(NCR 23-10)

4. The MAPEP August 2023 soil Fe- 55 result was evaluated as Not Acceptable.

The reported value was 346 Bq/kg and the known result was 1280 (acceptance range of 896- 1664 Bq/kg). This was TBEs initial evaluation for Fe-55 in soils. The result was received at the end of December and the root cause is under investigation. No client samples were associated with this cross-check. (CAR 23-31)

5. The Analytics September 2023 milk Sr -90 result was evaluated as Not Acceptable. The reported result was 7.28 pCi/L and the known result was 12.8 (57% of known). This sample was used as the workgroup duplicate and the carrier yields for both samples were 107% and 75%. The LCS recovery for the workgroup was at 106%. The ERA drinking water Sr -90 cross check that was analyzed around the same time was acceptable at 108%. There was no explanation for the failure. This is the first low biased failure for Sr -90 milk. The last failure (high) was in 2016. (NCR 23- 24)

6. The ERA RAD October 2023 water Gross Alpha result was evaluated as Not Acceptable. The reported result was 53.2 pCi/L and the known result was 70.6 (acceptable range of 54.0 - 87.2 pCi/L). The reported res ult was the workgroup duplicate and was within 75% of the known value (within TBE QC range). The original result was 63.3 pCi/L (90% of the known). Because the LCS result was biased slightly high, the decision was made to report the lower value. (NCR 23-20)

27

7. The ERA RAD October 2023 water I -131 result was evaluated as Not Acceptable. The reported value was 23.5 pCi/L and the known result was 29.7 (acceptable range of 25.8 - 33.6) The reported result was 79% of the

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

life. Going forward, the QA &/or Lab Mgr. will ensure that this analysis is started sooner. (NCR 23- 21)

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

V. References

1. HDI Offsite Dose Calculation Manual for Oyster Creek Generating Station, Procedure CY-OC-170-301.

2. United States Nuclear Regulatory Commission Branch Technical Position, An Acceptable Radiological Environmental Monitoring Program, Revision 1, November 1979.

3 Pre-Operational Environmental Radiation Survey, Oyster Creek Nuclear Electric Generating Station, Jersey Central Power and Light Company, March 1968.

VI. Errata

There was no errata data for 2023.

28 APPENDIX A

RADIOLOGICAL ENVIRONMENT AL MONITORING REPORT SUMM ARY

Intentionally left blank

APPENDIX B

LOCATION DESIGNATION, DISTANCE & DIRECTION, AND SAMPLE COLLECTION & ANALYTICAL METHODS Intentionally left blank TABLE B-1: Location Designation and Identification System for the Oyster Creek Generating Station

Sample Medium - APT = Air Particulate Clam = Clam AQS = Aquatic Sediment Crab = Crab DW = Drinking Water Fish = Fish GW = Ground Water SWA = Surface Water OSLD = Optically Stimulated Luminescence Dosimetry

Station Code - Stations Designation

Distance - Distance from the OCGS in miles

Azimuth - Azimuth with respect to the OCGS in degrees

Description - Meteorological sector in which the station is located and a narrative description

Figure B-1 Locations of REMP Stations within a 1-mile radius of the Oyster Creek Generating Station, 2023

B-7 Figure B-2 Locations of REMP Stations within a 1 to 5- mile radius of the Oyster Creek Generating Station, 2023 Figure B-3 Locations of REMP Stations greater than 5 miles from the Oyster Creek Generating Station, 2023 Intentionally left blank APPENDIX C

DATA TABLES AND FIGURES PRIMARY LABORATORY

Intentionally left blank Table C-I.1 CONCENTRATIONS OF TRITIUM IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD 23 24 33 94 01/17/23 < 269 < 283 02/15/23 < 563 < 572 03/16/23 < 597 < 603 04/18/23 < 530 < 522 05/16/23 < 496 < 501 06/05/23 < 542 < 536 < 537 < 543 07/18/23 < 514 < 511 08/16/23 < 531 < 533 09/20/23 < 559 < 554 10/02/23 < 580 < 564 < 197 < 191 11/20/23 < 518 < 526 12/19/23 < 505 < 522

MEAN ----

Table C-I.2 CONCENTRATIONS OF GAMMA EMITTERS IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137 23 06/05/23 < 6 < 9 < 15 < 7 < 6 10/03/23 < 6 < 7 < 18 < 7 < 6

MEAN -----

24 06/05/23 < 5 < 5 < 12 < 8 < 6 10/02/23 < 7 < 7 < 12 < 5 < 7

MEAN -----

33 01/17/23 < 6 < 6 < 17 < 8 < 8 02/15/23 < 5 < 7 < 11 < 6 < 6 03/16/23 < 5 < 7 < 11 < 7 < 5 04/18/23 < 9 < 8 < 14 < 8 < 8 05/16/23 < 6 < 6 < 15 < 7 < 5 06/20/23 < 8 < 9 < 12 < 8 < 8 07/18/23 < 7 < 8 < 17 < 9 < 7 08/16/23 < 6 < 6 < 12 < 7 < 5 09/20/23 < 7 < 8 < 16 < 8 < 8 10/24/23 < 7 < 8 < 18 < 9 < 9 11/20/23 < 7 < 6 < 16 < 9 < 9 12/19/23 < 9 < 9 < 24 < 8 < 9

MEAN -----

94 01/17/23 < 7 < 10 < 13 < 8 < 7 02/15/23 < 8 < 7 < 14 < 9 < 8 03/16/23 < 5 < 6 < 14 < 5 < 8 04/18/23 < 6 < 7 < 16 < 8 < 8 05/16/23 < 7 < 10 < 14 < 8 < 7 06/20/23 < 7 < 8 < 14 < 7 < 8 07/18/23 < 8 < 10 < 17 < 9 < 7 08/16/23 < 7 < 8 < 12 < 8 < 7 09/20/23 < 7 < 6 < 16 < 9 < 8 10/24/23 < 5 < 8 < 12 < 6 < 8 11/20/23 < 6 < 7 < 15 < 8 < 8 12/19/23 < 8 < 6 < 15 < 6 < 7

MEAN -----

Table C-II.1 CONCENTRATIONS OF TRITIUM IN DRINKING WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD 1N 1S 37 38 01/17/23 < 267 (1) <<289 275 02/15/23 < 581 (1) <<559 567 03/15/23 < 579 (1) <<600 593 04/18/23 < 521 (1) <<525 525 05/16/23 < 500 (1) <<506 505 06/20/23 < 549 (1) <<552 542 07/18/23 < 497 (1) <<507 499 08/16/23 < 532 (1) <<534 538 09/20/23 < 545 (1) <<555 557 10/24/23 < 560 (1) <<190 198 11/20/23 < 523 (1) <<537 517 12/13/23 < 548 (1) <<561 533 MEAN - - -

Table C-II.2 CONCENTRATIONS OF GROSS BETA IN DRINKING WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD 1N 1S 37 38 01/17/23 < 1.7 (1) 2.2 +/- 1.1 2.3 +/- 1.1 02/15/23 < 1.1 (1) < 1.7 < 1.8 03/15/23 < 2.0 (1) < 1.9 < 1.8 04/18/23 < 1.7 (1) 2.2 +/- 1.1 2.7 +/- 1.2 05/16/23 < 1.7 (1) 1.9 +/- 1.1 < 1.6 06/20/23 2.5 +/- 1.2 (1) 1.9 +/- 1.1 2.6 +/- 1.1 07/18/23 < 2.1 (1) < 1.8 1.9 +/- 1.2 08/16/23 2.6 +/- 1.2 (1) 2.8 +/- 1.2 < 1.6 09/20/23 < 1.9 (1) 1.9 +/- 1.1 3.2 +/- 1.2 10/24/23 < 2.0 (1) 1.9 +/- 1.2 4.0 +/- 1.3 11/20/23 3.3 +/- 1.3 (1) 2.9 +/- 1.3 2.2 +/- 1.3 12/13/23 < 1.8 (1) 2.9 +/- 1.2 2.0 +/- 1.2 MEAN +/- 2 STD DEV 2.8 +/- 0.8 2.3 +/- 0.9 2.6 +/- 1.4

THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES (1) SEE PROGRAM EXCEPTIONS SECTION FOR EXPLANATION Table C-II.3 CONCENTRATIONS OF GAMMA EMITTERS IN DRINKING WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

SITE Mn-54 Co-60 Zn-65 Cs-134 Cs-137 1N 01/17/23 < 6 < 8 < 12 < 7 < 7 02/15/23 < 7 < 8 < 16 < 9 < 7 03/15/23 < 7 < 6 < 14 < 7 < 8 04/18/23 < 8 < 9 < 14 < 7 < 7 05/16/23 < 5 < 6 < 11 < 6 < 6 06/20/23 < 7 < 9 < 12 < 9 < 8 07/19/23 < 7 < 6 < 20 < 8 < 6 08/16/23 < 7 < 7 < 15 < 8 < 7 09/20/23 < 6 < 6 < 11 < 8 < 6 10/24/23 < 5 < 5 < 12 < 6 < 6 11/20/23 < 7 < 6 < 16 < 8 < 7 12/13/23 < 7 < 8 < 18 < 7 < 8

MEAN -----

1S (1)

37 01/17/23 < 6 < 4 < 12 < 4 < 6 02/15/23 < 6 < 5 < 11 < 5 < 8 03/16/23 < 6 < 5 < 12 < 5 < 7 04/18/23 < 6 < 7 < 9 < 7 < 8 05/16/23 < 7 < 9 < 15 < 8 < 8 06/20/23 < 7 < 6 < 16 < 7 < 6 07/18/23 < 6 < 6 < 14 < 6 < 5 08/16/23 < 7 < 9 < 15 < 8 < 6 09/20/23 < 8 < 10 < 16 < 7 < 7 10/24/23 < 5 < 6 < 10 < 5 < 6 11/20/23 < 6 < 10 < 14 < 8 < 7 12/19/23 < 6 < 9 < 16 < 7 < 8 MEAN -----

38 01/17/23 < 7 < 5 < 15 < 5 < 7 02/15/23 < 6 < 6 < 13 < 6 < 7 03/16/23 < 6 < 7 < 16 < 8 < 7 04/18/23 < 7 < 7 < 17 < 8 < 5 05/16/23 < 5 < 6 < 10 < 5 < 6 06/20/23 < 5 < 6 < 15 < 6 < 7 07/18/23 < 5 < 7 < 12 < 7 < 6 08/16/23 < 5 < 9 < 17 < 5 < 8 09/20/23 < 5 < 6 < 11 < 7 < 6 10/24/23 < 5 < 4 < 9 < 5 < 5 11/20/23 < 6 < 7 < 14 < 8 < 7 12/19/23 < 7 < 8 < 15 < 9 < 7 MEAN -----

Table C-III.1 CONCENTRATIONS OF TRITIUM IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD MW-24-3A W-3C 01/31/23 - < <01/31/23570 558 05/03/23 - < <05/03/23187187 07/06/23 - < <07/06/23491488 10/18/23 - < <10/18/23192192

MEAN --

Table C-III.2 CONCENTRATIONS OF GAMMA EMITTERS IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137 MW-24-3A 01/31/23 - 01/31/23 < 6 < 9 < 16 < 6 < 7 05/03/23 - 05/03/23 < 5 < 6 < 10 < 7 < 6 07/06/23 - 07/06/23 < 6 < 5 < 13 < 7 < 5 10/18/23 - 10/18/23 < 6 < 8 < 15 < 5 < 7

MEAN -----

W-3C 01/31/23 - 01/31/23 < 7 < 7 < 15 < 7 < 7 05/03/23 - 05/03/23 < 6 < 8 < 17 < 7 < 7 07/06/23 - 07/06/23 < 6 < 8 < 16 < 6 < 8 10/18/23 - 10/18/23 < 8 < 9 < 17 < 8 < 6

MEAN -----

Table C-IV.1 CONCENTRATIONS OF GAMMA EMITTERS IN PREDATOR (FISH) SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/KG WET +/- 2 SIGMA

COLLECTION SITE PERIOD K-40 Mn-54 Co-60 Zn-65 Cs-134 Cs-137 33 06/05/23 3879 +/- 1093 < 58 < 75 < 113 < 66 < 56 06/05/23 5312 +/- 1245 < 76 < 61 < 123 < 77 < 70 06/05/23 3726 +/- 979 < 50 < 66 < 84 < 68 < 53 06/05/23 3803 +/- 1122 < 67 < 87 < 164 < 85 < 81 10/02/23 4213 +/- 1191 < 67 < 71 < 142 < 87 < 73 10/02/23 4298 +/- 1294 < 78 < 62 < 165 < 95 < 67 10/02/23 2987 +/- 1170 < 68 < 68 < 148 < 83 < 76 10/02/23 2368 +/- 1133 < 70 < 129 < 207 < 103 < 96 10/02/23 4868 +/- 1288 < 85 < 77 < 173 < 76 < 95

MEAN +/- 2 STD DEV 3939 +/- 1788 - ----

93 06/06/23 2458 +/- 1331 < 72 < 53 < 155 < 64 < 94 06/06/23 3770 +/- 1017 < 55 < 79 < 163 < 46 < 71 06/06/23 4831 +/- 1124 < 60 < 81 < 174 < 65 < 69 10/03/23 5059 +/- 1174 < 56 < 52 < 124 < 56 < 59 10/03/23 3459 +/- 1014 < 78 < 77 < 203 < 95 < 82 10/03/23 4876 +/- 1126 < 49 < 65 < 120 < 58 < 56 10/03/23 4706 +/- 1092 < 50 < 66 < 135 < 74 < 63

MEAN +/- 2 STD DEV 4166 +/- 1934 - ----

THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES Table C-IV.2 CONCENTRATIONS OF GAMMA EMITTERS IN CLAM AND CRAB SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/KG WET +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137K-40

23 Clams 06/05/23 1577 +/- 788 < 63 < 23 < 129 < 65 < 61 10/03/23 1788 +/- 665 < 48 < 52 < 103 < 59 < 40

MEAN +/- 2 STD DEV 1683 +/- 298 -----

24 Clams 06/05/23 1637 +/- 774 < 54 < 40 < 117 < 69 < 43 10/02/23 2246 +/- 859 < 62 < 83 < 137 < 71 < 76

MEAN +/- 2 STD DEV 1942 +/- 861 -----

94 Clams 06/07/23 2986 +/- 867 < 83 < 67 < 113 < 89 < 85 10/04/23 1530 +/- 839 < 55 < 57 < 134 < 59 < 54

MEAN +/- 2 STD DEV 2258 +/- 2059 -----

33 Crabs 09/28/23 2874 +/- 864 < 61 < 60 < 111 < 66 < 65

MEAN +/- 2 STD DEV 2874 +/- 0 -----

THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES

Table C-VI.1 CONCENTRATIONS OF GROSS BETA IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF E-3 PCI/CU METER +/- 2 SIGMA

COLLECTION GROUP IIIGROUP I GROUP II PERIOD 20 66 111 71 73 C 12/27/22 - 01/10/23 20 +/- 3 22 +/- 3 26 +/- 3 23 +/- 3 23 +/- 3 22 +/- 3 01/10/23 - 01/24/23 9 +/- 2 13 +/- 3 11 +/- 2 15 +/- 3 14 +/- 3 13 +/- 3 01/24/23 - 02/07/23 17 +/- 3 19 +/- 3 19 +/- 3 17 +/- 3 18 +/- 3 17 +/- 3 02/07/23 - 02/21/23 21 +/- 3 22 +/- 3 19 +/- 3 24 +/- 3 23 +/-318+/-3 02/21/23 - 03/07/23 15 +/- 3 16 +/- 3 15 +/- 3 16 +/- 3 14 +/- 3 15 +/- 3 03/07/23 - 03/21/23 13 +/- 8 14 +/- 3 13 +/- 3 15 +/- 3 13 +/- 3 12 +/-2 03/21/23 - 04/04/23 19 +/- 3 20 +/- 3 18 +/- 3 20 +/- 3 4 +/- 2 21 +/- 3 04/04/23 - 04/18/23 17 +/- 3 20 +/- 3 17 +/- 3 22 +/- 3 18 +/- 3 16 +/- 3 04/18/23 - 05/02/23 11 +/- 3 14 +/- 3 13 +/- 3 15 +/- 3 10 +/- 3 13 +/- 3 05/02/23 - 05/16/23 13 +/- 3 11 +/- 3 11 +/- 3 13 +/- 3 11 +/- 3 12 +/- 3 05/16/23 - 05/30/23 10 +/- 2 11 +/- 3 10 +/- 2 5 +/- 2 12 +/- 3 9 +/- 2 05/30/23 - 06/13/23 7 +/- 2 10 +/- 3 14 +/- 3 12 +/- 3 10 +/-3 14 +/-3 06/13/23 - 06/27/23 11 +/- 3 12 +/- 3 10 +/- 3 13 +/- 3 8 +/- 2 10 +/- 3 06/27/23 - 07/11/23 15 +/- 3 16 +/- 3 17 +/- 3 21 +/- 3 14 +/- 3 12 +/- 3 07/11/23 - 07/25/23 21 +/- 3 22 +/- 3 21 +/- 3 21 +/- 3 20 +/- 3 22 +/- 3 07/25/23 - 08/08/23 16 +/- 3 16 +/- 3 15 +/- 3 19 +/- 3 15 +/- 3 16 +/- 3 08/08/23 - 08/21/23 22 +/- 3 4 +/- 2 21 +/- 3 23 +/- 3 16 +/- 3 18 +/- 3 08/21/23 - 09/06/23 19 +/- 3 (1) 19 +/- 3 20 +/- 3 17 +/- 3 20 +/- 3 09/06/23 - 09/19/23 26 +/- 3 26 +/- 4 23 +/- 3 26 +/- 4 22 +/- 3 21 +/- 3 09/19/23 - 10/03/23 11 +/- 3 11 +/- 3 10 +/- 3 11 +/- 3 9 +/- 3 11 +/- 3 10/03/23 - 10/17/23 7 +/- 1 9 +/- 1 8 +/- 1 8 +/- 1 10 +/- 2 10 +/- 1 10/17/23 - 10/31/23 14 +/- 3 14 +/- 3 11 +/- 3 15 +/- 3 11 +/- 3 13 +/- 3 10/31/23 - 11/14/23 24 +/- 3 23 +/- 3 20 +/- 3 23 +/- 321+/-326+/-3 11/14/23 - 11/28/23 19 +/- 3 18 +/- 3 17 +/- 3 15 +/- 3 23 +/- 5 18 +/- 3 11/28/23 - 12/13/23 23 +/- 3 22 +/- 3 8 +/- 2 24 +/- 3 22 +/- 3 24 +/- 3 12/13/23 - 12/26/23 18 +/- 3 16 +/- 3 17 +/- 3 16 +/- 3 11 +/- 3 17 +/- 3

MEAN +/- 2 STD DEV 16 +/- 11 16 +/- 11 15 +/- 10 17 +/- 11 15 +/- 11 16 +/- 9

THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES (1) SEE PROGRAM EXCEPTIONS SECTION FOR EXPLANATION

Table C-VI.3 CONCENTRATIONS OF STRONTIUM IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF E-3 PCI/CU METER +/- 2 SIGMA

COLLECTION SITE PERIOD SR-90 20 12/27/22 - 04/04/23 < 4 04/04/23 - 06/27/23 < 7 06/27/23 - 10/03/23 < 5 10/03/23 - 12/26/23 < 4

MEAN -

66 12/27/22 - 04/04/23 < 4 04/04/23 - 06/27/23 < 7 06/27/23 - 10/03/23 < 7 10/03/23 - 12/26/23 < 8

MEAN -

71 12/30/21 - 04/04/23 < 6 04/04/23 - 06/27/23 < 9 06/27/23 - 10/06/23 < 6 10/06/23 - 12/27/23 < 6

MEAN -

73 12/27/22 - 04/04/23 < 4 04/04/23 - 06/27/23 < 9 06/27/23 - 10/03/23 < 5 10/03/23 - 12/26/23 < 6

MEAN -

111 12/27/22 - 04/04/23 < 5 04/04/23 - 06/27/23 < 7 06/27/23 - 10/03/23 < 5 10/03/23 - 12/26/23 < 5

MEAN -

C 12/27/22 - 04/04/23 < 3 04/04/23 - 06/27/23 < 9 06/27/23 - 10/03/23 < 5 10/03/23 - 12/26/23 < 4

MEAN -

Table C-VI.4 CONCENTRATIONS OF GAMMA EMITTERS IN AIR PARTICULATE SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF E-3 PCI/CU METER +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Cs-134 Cs-137Be-7 20 12/27/22 - 04/04/23 45 +/- 19 < 1 < 2 < 2 <2 04/04/23 - 06/27/23 62 +/- 21 < 2 < 2 < 2 < 2 06/27/23 - 10/03/23 45+/-16 <2<2<2 <1 10/03/23 - 12/26/23 51+/-16 <2<3<2 <2

MEAN +/- 2 STD DEV 55+/-23--- -

66 12/27/22 - 04/04/23 53 +/- 18 < 2 < 2 < 2 < 2 04/04/23 - 06/27/23 52 +/- 22 < 3 < 4 < 3 < 3 06/27/23 - 10/03/23 47+/-17 <3<3<3 <3 10/03/23 - 12/26/23 50+/-14 <2<2<2 <2

MEAN +/- 2 STD DEV 52+/-7 --- -

71 12/27/22 - 04/04/23 61 +/- 16 < 2 < 2 < 2 < 2 04/04/23 - 06/27/23 63 +/- 25 < 2 < 2 < 2 < 2 06/27/23 - 10/03/23 55+/-15 <1<2<1 <2 10/03/23 - 12/26/23 53+/-21 <3<3<3 <2

MEAN +/- 2 STD DEV 59+/-9 --- -

73 12/27/22 - 04/04/23 39 +/- 15 < 1 < 1 < 2 < 2 04/04/23 - 06/27/23 52 +/- 21 < 2 < 2 < 2 < 2 06/27/23 - 10/03/23 50+/-16 <2<3<2 <1 10/03/23 - 12/26/23 37+/-19 <2<3<2 <2

MEAN +/- 2 STD DEV 56+/-52--- -

111 12/27/22 - 04/04/23 57 +/- 15 < 2 < 2 < 3 < 2 04/04/23 - 06/27/23 55 +/- 17 < 3 < 3 < 2 < 2 06/27/23 - 10/03/23 41 +/- 22 < 1<2< 2 <2 10/03/23 - 12/26/23 45+/-15 <3<4<4 <3

MEAN +/- 2 STD DEV 50+/-13--- -

C 12/27/22 - 04/04/23 67 +/- 18 < 2 < 3 < 3 < 3 04/04/23 - 06/27/23 96 +/- 29 < 3 < 3 < 3 < 3 06/27/23 - 10/03/23 53 +/- 20 < 2 < 2 < 2 < 2 10/03/23 - 12/26/23 44 +/- 14 < 2 < 2 < 2 < 2

MEAN +/- 2 STD DEV 68+/-42----

THE MEAN AND TWO STANDARD DEVIATION ARE CALCULATED USING THE POSITIVE VALUES Table C-VII.1 QUARTERLY OSLD RESULTS FOR OYSTER CREEK GENERATING STATION, 2023(1)

RESULTS IN UNITS OF MILLIREM/STD. QUARTER +/- 2 STANDARD DEVIATION

• Results on this table reflect a "N et" result (background subtracted)

STATION MEAN CODE +/- 2 S.D. JAN - MAR APR - JUN JUL - SEP OCT - DEC 1 0.4 +/- 0.6 0.7 0.0 0.5 0.4 6 -0.4 +/- 2.0 -0.5 -1.0 -1.2 1.0 8 -1.2 +/- 2.5 -1.3 -0.3 -2.9 -0.3 9 -2.5 +/- 1.9 -1.8 -3.2 -3.5 -1.6 22 2.6 +/- 2.3 2.1 1.4 2.9 4.1 51 1.7 +/- 0.8 1.9 1.4 1.4 2.2 52 3.7 +/- 4.1 3.8 2.0 6.6 2.6 53 1.0 +/- 2.0 2.4 0.5 0.7 0.3 54 -1.5 +/- 1.4 -1.8 -1.2 -2.3 -0.7 55 5.3 +/- 3.6 6.9 5.8 5.8 2.8 56 3.4 +/- 3.4 3.8 1.4 5.4 2.9 57 -0.3 +/- 0.9 -0.9 -0.1 -0.4 0.2 58 -1.3 +/- 2.0 -0.9 -1.3 -2.7 -0.4 59 0.8 +/- 1.3 0.7 0.0 1.1 1.5 61 -0.4 +/- 2.1 -0.3 -1.4 -1.0 1.0 62 0.4 +/- 1.1 0.1 -0.1 0.4 1.1 63 0.4 +/- 1.1 1.0 0.4 -0.3 0.5 64 0.4 +/- 0.6 0.3 0.7 0.0 0.5 65 -0.6 +/- 0.9 -0.3 -0.2 -1.1 -1.0 66 -1.1 +/- 1.0 -0.8 -1.4 -1.7 -0.7 68 -3.1 +/- 2.7 -2.9 -2.1 -5.0 -2.4 71 0.0 +/- 2.2 0.9 -1.3 -0.5 0.9 72 -0.5 +/- 1.3 0.0 -1.3 0.1 -0.8 73 -2.0 +/- 1.6 -0.9 -2.4 -2.8 -2.1 74 -0.9 +/- 2.2 0.2 -1.7 -1.9 -0.1 75 0.3 +/- 1.6 0.5 1.1 -0.8 0.5 78 -0.1 +/- 0.3 -0.3 -0.1 0.1 -0.1 79 1.8 +/- 1.2 1.8 1.8 1.2 2.7 81 0.5 +/- 1.1 -0.1 0.8 0.1 1.1 98 -1.7 +/- 2.3 -0.8 -2.0 -3.2 -0.8 99 -2.0 +/- 3.5 0.4 -3.0 -2.4 -2.9 T1 0.6 +/- 2.4 0.0 -0.4 2.3 0.6 100 -1.6 +/- 2.3 -0.7 -2.3 -2.9 -0.6 101 -1.4 +/- 1.1 -1.1 -2.2 -1.5 -0.9 102 -0.2 +/- 2.5 0.6 -0.9 -1.5 1.2 103 0.2 +/- 0.8 0.3 -0.1 -0.3 0.7 104 0.0 +/- 1.6 0.5 0.3 0.5 -1.1 106 -2.1 +/- 0.9 -1.7 -2.7 -1.8 -2.3 107 -1.7 +/- 1.3 -1.3 -2.7 -1.5 -1.5 109 -1.0 +/- 2.6 -0.1 -3.0 -0.8 -0.3 110 -1.9 +/- 3.5 0.4 -3.1 -3.5 -1.6 112 1.3 +/- 1.4 1.1 2.2 1.6 0.5 113 0.2 +/- 2.6 0.0 -1.0 (2) 1.6

C 19.2 +/- 2.8 18.3 20.4 20.3 18.0

(1) Note: There are two (2) OSLD's posted at each indicator station for redundancy and data recovery. In reporting results, the average of the gross mean for the two readings is reported. There are four (4) single OSLD's posted at Control Station C and the average of the gross mean for the four readings is reported.

APPENDIX D

DATA TABLES QC COMPARISON SAMPLES The following section presents the results of data analysis performed by the QC laboratory, Microbac L aboratories - Northbrook (formerly Environmental Inc.). Duplicate samples were obtained from several locations and media and were split with the primary laboratory, Teledyne Brown Engineering (TBE) and the QC Laboratory. Comparison of the results for all media were within expected ranges.

Table D-I.1 CONCENTRATIONS OF TRITIUM IN SURFACE WATER SAMPLES COLLECTED COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD OC-24 (EIML)24 (TBE) QCA (TBE) 06/05/23 < 536 < 529 < 157 10/02/23 < 564 < 576 < 137 Table D-I.2 CONCENTRATIONS OF GAMMA EMITTERS IN SURFACE WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137 24 06/05/23 < 5 < 5 < 12 < 8 < 6 (TBE) 10/02/23 < 7 < 7 < 12 < 5 < 7

QCA 06/05/23 < 4 < 7 < 9 < 6 < 7 (TBE) 10/02/23 < 7 < 9 < 14 < 10 < 8

OC-24 06/05/23 < 2 < 1 < 3 (1) < 2 (EIML) 10/02/23 < 8 < 4 < 10 (1) < 7

`

(1) Not reported Table D-II.1 CONCENTRATIONS OF TRITIUM IN DRINKING WATER WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD OC-QC1N (Microbac)1N (TBE) 01/17/23 < 267 < 161 02/15/23 < 581 < 154 03/15/23 < 579 < 164 04/18/23 < 521 < 161 05/16/23 < 500 < 161 06/20/23 < 549 < 162 07/18/23 < 497 < 162 08/16/23 < 532 < 158 09/20/23 < 545 < 163 10/24/23 < 560 < 171 11/20/23 < 523 < 173 12/13/23 < 548 < 171

Table D-II.2 CONCENTRATIONS OF GROSS BETA IN DRINKING WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD OC-QC1N (Microbac)1N (TBE) 01/17/23 < 1.7 < 0.9 02/15/23 < 1.1 < 1.6 03/15/23 < 2.0 < 1.01 04/18/23 < 1.7 < 0.9 05/16/23 < 1.7 < 0.9 06/20/23 2.5 +/- 1.2 < 1.7 07/18/23 < 2.1 < 0.9 08/16/23 2.6 +/- 1.2 < 0.9 09/20/23 < 1.9 < 0.9 10/24/23 < 2.0 < 0.9 11/20/23 3.3 +/- 1.3 < 0.9 12/13/23 < 1.8 < 0.9 Table D-II.3 CONCENTRATIONS OF GAMMA EMITTERS IN DRINKING WATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137 1N 01/17/23 < 6 < 8 < 12 < 7 < 7 (TBE) 02/15/23 < 7 < 8 < 16 < 9 < 7 03/15/23 < 7 < 6 < 14 < 7 < 8 04/18/23 < 8 < 9 < 14 < 7 < 7 05/16/23 < 5 < 6 < 11 < 6 < 6 06/20/23 < 7 < 9 < 12 < 9 < 8 07/19/23 < 7 < 6 < 20 < 8 < 6 08/16/23 < 7 < 7 < 15 < 8 < 7 09/20/23 < 6 < 6 < 11 < 8 < 6 10/24/23 < 5 < 5 < 12 < 6 < 6 11/20/23 < 7 < 6 < 16 < 8 < 7 12/13/23 < 7 < 8 < 18 < 7 < 8

OC-QC1N 01/17/23 < 1 < 1 < 2 (1) <1 (Microbac) 02/15/23 < 1 < 1 < 2 (1) <1 03/15/23 < 1 < 1 < 2 (1) <1 04/18/23 < 2 < 2 < 5 (1) <3 05/16/23 < 5 < 4 < 7 (1) <5 06/20/23 < 2 < 5 < 5 (1) <5 07/19/23 < 8 < 4 < 6 (1) <6 08/16/23 < 6 < 5 < 9 (1) <5 09/20/23 < 3 < 10 < 6 (1) <8 10/24/23 < 2 < 2 < 4 (1) <3 11/20/23 < 3 < 3 < 6 (1) `<3 12/13/23 < 3 < 3 < 7 (1) <3

(1) Not reported Table D-III.1 CONCENTRATIONS OF TRITIUM IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION PERIOD W-3COC-W-3C (EIML) 01/31/23 - 01/31/23 < < 159558 05/03/23 - 05/03/23 < < 162187 7/6/2023 - 07/06/23 < < 163488 10/18/23 - 10/18/23 < < 169192 Table D-III.2 CONCENTRATIONS OF GAMMA EMITTERS IN GROUNDWATER SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137 W-3C 01/31/23 - 01/31/23 < 7 < 7 < 17 < 7 < 7 05/03/23 - 05/03/23 < 7 < 8 < 16 < 9 < 10 07/06/23 - 07/06/23 < 7 < 8 < 16 < 9 < 10 10/18/23 - 10/18/23 < 7 < 8 < 16 < 9 < 10

OC -W-3C 01/31/23 - 01/31/23 < 4 < 3 < 6 (1) < 3 (EIML) 05/03/23 - 05/03/23 < 2 < 1 < 3 (1) < 2 07/06/23 - 07/06/23 < 3 < 6 < 5 (1) < 5 10/18/23 - 10/18/23 < 2 < 2 < 4 (1) < 3

`

(1) Not reported Table D-IV.1 CONCENTRATIONS OF GAMMA EMITTERS IN CLAM SAMPLES COLLECTED IN THE VICINITY OF OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/KG WET +/- 2 SIGMA

COLLECTION SITE PERIOD Mn-54 Co-60 Zn-65 Cs-134 Cs-137K- 0 24 06/05/23 1637 +/- 774 < 54 < 40 < 117 < 69 < 43 (TBE)

OC-24 06/05/23 1780 +/- 90 < 3 < 3 < 6 (1) < 3 (EIML)

`

`

APPENDIX E

INTER-LABORATORY COMPARISON PROGRAM Intentionally left blank Analytics Environmental Radioactivity Cross Check Program Table E.1 Teledyne Brown Engineering Environmental Services TBE Known Month/Year Identification Number Matrix Nuclide Units Reported Value (a) Ratio of TBE to Analytics Result Evaluation (b)

Value

March 2023 E13826 Milk Sr-89 pCi/L 70.5 93.1 0.76 W Sr-90 pCi/L 12.3 14.7 0.84 A

E13827 Milk Ce-141 pCi/L 127 139 0.91 A Co-58 pCi/L 119 131 0.91 A Co-60 pCi/L 250 279 0.90 A Cr-51 pCi/L 246 302 0.82 A Cs-134 pCi/L 172 200 0.86 A Cs-137 pCi/L 125 140 0.89 A Fe-59 pCi/L 122 122 1.00 A I-131 pCi/L 70.2 82.0 0.86 A Mn-54 pCi/L 165 180 0.92 A Zn-65 pCi/L 306 306 1.00 A

E13828 Charcoal I-131 pCi 79.0 89.9 0.88 A

E13829 AP Ce-141 pCi 91.9 87.8 1.05 A Co-58 pCi 87.5 82.5 1.06 A Co-60 pCi 199 176 1.13 A Cr-51 pCi 218 191 1.14 A Cs-134 pCi 119 126 0.94 A Cs-137 pCi 92.4 88.7 1.04 A Fe-59 pCi 95.5 76.9 1.24 W Mn-54 pCi 120 113 1.06 A Zn-65 pCi 179 193 0.93 A

E13830 Soil Ce-141 pCi/g 0.224 0.220 1.02 A Co-58 pCi/g 0.193 0.207 0.93 A Co-60 pCi/g 0.406 0.441 0.92 A Cr-51 pCi/g 0.464 0.477 0.97 A Cs-134 pCi/g 0.334 0.316 1.06 A Cs-137 pCi/g 0.270 0.288 0.94 A Fe-59 pCi/g 0.183 0.193 0.95 A Mn-54 pCi/g 0.263 0.284 0.93 A Zn-65 pCi/g 0.475 0.484 0.98 A

E13831 AP Sr-89 pCi 99.4 90.8 1.09 A Sr-90 pCi 14.6 14.3 1.02 A

(a) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) Analytics evaluation based on TBE internal QC limits:

A = Acceptable - reported result falls within ratio limits of 0.80-1.20 W = Acceptable with warning - reported result falls within 0.70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of < 0.70 and > 1.30

(Page 1 of 2)

Analytics Environmental Radioactivity Cross Check Program Table E.1 Teledyne Brown Engineering Environmental Services TBE Known Month/Year Identification Number Matrix Nuclide Units Reported Value (a) Ratio of TBE to Analytics Result Evaluation (b)

Value

September 2023 E13832 Milk Sr-89 pCi/L 49.8 71.4 0.70 W Sr-90 pCi/L 7.28 12.8 0.57 N(1)

E13833 Milk Ce-141 pCi/L 93.4 104 0.90 A Co-58 pCi/L 58.2 65.8 0.88 A Co-60 pCi/L 190 223 0.85 A Cr-51 pCi/L 207 205 1.01 A Cs-134 pCi/L 96.0 114 0.84 A Cs-137 pCi/L 121 141 0.86 A Fe-59 pCi/L 78.8 78.8 1.00 A I-131 pCi/L 27.9 37.4 0.75 W Mn-54 pCi/L 128 146 0.88 A Zn-65 pCi/L 185 203 0.91 A

E13834 Charcoal I-131 pCi 76.9 78.7 0.98 A

E13835 AP Ce-141 pCi 91.9 87.1 1.05 A Co-58 pCi 58.7 55.2 1.06 A Co-60 pCi 200 187 1.07 A Cr-51 pCi 192 172 1.12 A Cs-134 pCi 89.6 96 0.94 A Cs-137 pCi 109 119 0.92 A Fe-59 pCi 68.3 66.1 1.03 A Mn-54 pCi 129 123 1.05 A Zn-65 pCi 163 171 0.96 A

E13836 Soil Ce-141 pCi/g 0.228 0.184 1.24 W Co-58 pCi/g 0.103 0.116 0.89 A Co-60 pCi/g 0.364 0.394 0.92 A Cr-51 pCi/g 0.371 0.362 1.02 A Cs-134 pCi/g 0.176 0.202 0.87 A Cs-137 pCi/g 0.285 0.315 0.90 A Fe-59 pCi/g 0.140 0.139 1.00 A Mn-54 pCi/g 0.237 0.259 0.92 A Zn-65 pCi/g 0.349 0.359 0.97 A

E13837 AP Sr-89 pCi 74.6 80.2 0.93 A Sr-90 pCi 13.9 14.4 0.96 A

(a) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation (b) Analytics evaluation based on TBE internal QC limits:

A = Acceptable - reported result falls within ratio limits of 0.80-1.20 W = Acceptable with warning - reported result falls within 0.70-0.80 or 1.20-1.30 N = Not Acceptable - reported result falls outside the ratio limits of < 0.70 and > 1.30

(1) See NCR 23-24

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DOE's Mixed Analyte Performance Evaluation Program (MAPEP)

Table E.2 Teledyne Brown Engineering Environmental Services TBE Known Month/Year IdentificationNumber Matrix Nuclide Units Reported Value (a) Acceptance Range Evaluation (b)

Value February 2023 23-MaS48 Soil Ni-63 Bq/kg 294 1130 791 - 1469 N(3)

23-MaSU48 Urine Cs-134 Bq/L 9.92 10 6.7 - 12.4 A Cs-137 Bq/L 0.0994 (1) A Co-57 Bq/L 9.35 8.67 6.07 - 11.27 A Co-60 Bq/L 9.03 8.13 5.69 - 10.57 A Mn-54 Bq/L 11.80 10.0 7.0 - 13.0 A U-234 Bq/L 0.01 Not spiked U-238 Bq/L 0.01 Not spiked Zn-65 Bq/L 10.60 9.29 6.50 - 12.08 A

23-MaW48 Water Ni-63 Bq/L 23.1 27.3 19.1 - 35.5 A

23-RdV48 Vegetation Cs-134 Bq/sample 5.6 7.6 5.32 - 9.88 W Cs-137 Bq/sample 0.03 (1) A Co-57 Bq/sample 5.9 6.9 4.85 - 9.01 A Co-60 Bq/sample 5.00 6.51 4.56 - 8.46 W Mn-54 Bq/sample 6.08 8.03 5.62 - 10.44 W Sr-90 Bq/sample 0.05 (1) N(4)

Zn-65 Bq/sample 5.49 7.43 5.20 - 9.66 W

August 2023 23-MaS49 Soil Fe-55 Bq/kg 346 1280 896 - 1664 N(5)

Ni-63 Bq/kg 1260 1370 959 - 1781 A

23-MaW49 Water Ni-63 Bq/L 1.0 1 (2) A

23-RdV49 Vegetation Cs-134 Bq/sample 3.860 4.98 3.49 - 6.47 W Cs-137 Bq/sample 0.027 (1) A Co-57 Bq/sample 3.88 4.24 2.97 - 5.51 A Co-60 Bq/sample 2.37 2.79 1.95 - 3.63 A Mn-54 Bq/sample 2.04 2.56 1.79 - 3.33 W Sr-90 Bq/sample 0.96 1.17 0.82 - 1.52 A Zn-65 Bq/sample -0.514 (1)A

E~F tric=me~surements EbF albLjAmbm=ev~lu~tionW A=Z=Accept~ble=J=reported=result=f~lls=within=r~tio=limits=of=MKUMJNKOM

==========t=Z=Accept~ble=with=w~rning=J=reported=result=f~lls=within=MKTMJMKUM=or=NKOMJNKPM

ENF c~lse=positive=test EOF EPF NCR 23-08 (4) See NCR 23-09 (5) Initial evaluation - See CAR 23-31

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ERA Environmental Radioactivity Cross Check Program Table E.3 Teledyne Brown Engineering Environmental Services Month/Year Identification Known Number Matrix Nuclide Units TBE Reported Value Value (a) Acceptance Limits Evaluation (b)

March 2023 MRAD-38 Water Am-241 pCi/L 28.1 32.1 22.0 - 41.0 A Fe-55 pCi/L 1180 1380 811 - 2010 A Pu-238 pCi/L 65.6 70.7 42.5 - 91.6 A Pu-239 pCi/L 82.9 92.4 57.2 - 114 A

Soil Sr-90 pCi/kg 2630 2580 803 - 4020 A

AP GR-A pCi/filter 69.6 76.8 40.1 - 127 A GR-B pCi/filter 36.8 32.8 19.9 - 49.6 A

April 2023 RAD-133 Water Ba-133 pCi/L 26.0 22.3 N17.1 - 25.8 (1)

Cs-134 pCi/L 72.1 77.6 A63.4 - 85.4 Cs-137 pCi/L 62.1 63.1 A56.8 - 72.2 Co-60 pCi/L 32.6 30.3 A26.7 - 36.1 Zn-65 pCi/L 253 242 A218 - 283 GR-A pCi/L 34.2 29.2 A14.9 - 38.2 GR-B pCi/L 64.3 60.7 A41.8 - 67.4 U-Nat pCi/L 61.75 62.7 A51.2 - 69.0 H-3 pCi/L 13,300 12700 A11,100 - 14,000 Sr-89 pCi/L 67.0 61.1 A49.2 - 69.0 Sr-90 pCi/L 36.5 36.0 A26.4 - 41.5 I-131 pCi/L 24.3 28.723.9 - 33.6 A

September 2023 MRAD-39 Water Am-241 pCi/L 54.0 71.0 48.7 - 90.8 A Fe-55 pCi/L 2430 2630 1550 - 3830 A Pu-238 pCi/L 172 177 106 - 229 A Pu-239 pCi/L 171 182 113 - 224 A

Soil Sr-90 pCi/kg 9580 6800 2120 - 10,600 A

AP GR-A pCi/filter 82.2 79.8 41.7 - 131 A GR-B pCi/filter 54.3 42.6 25.8 - 64.4 A

October 2023 RAD-135 Water Ba-133 pCi/L 86.3 92.2 73.8 - 111 A Cs-134 pCi/L 38.4 41.2 27.9 - 54.5 A Cs-137 pCi/L 194 199 161 - 237 A Co-60 pCi/L 49.5 47.8 33.8 - 61.8 A Zn-65 pCi/L 59.7 57.0 23.7 - 90.3 A GR-A pCi/L 53.2 70.6 54.0 - 87.2 N(2)

GR-B pCi/L 46.9 42.2 30.5 - 53.9 A U-Nat pCi/L 51.26 51.7 45.9- 57.5 A H-3 pCi/L 20,100 22,900 19,700 - 26,100 A Sr-89 pCi/L 51.1 38.2 25.2 - 51.2 A Sr-90 pCi/L 31.7 35.7 30.3 - 41.1 A I-131 pCi/L 23.5 29.7 25.8 - 33.6 N(3)

(a) The ERA known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation.

(b) ERA evaluation:

A = Acceptable - Reported value falls within the Acceptance Limits N = Not Acceptable - Reported value falls outside of the Acceptance Limits (1) See NCR 23-10 (2) See NCR 23-20 (3) See NCR 23-21

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APPENDIX F

ERRATA DATA

Intentionally left blank

There was no errata data for 2023.

Intentionally left blank APPENDIX G

ANNUAL RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM REPORT (ARGPPR)

Intentionally left blank Docket No: 50- 219

OYSTER CREEK GENERATING STATION UNIT 1

Annual Radiological Groundwater Protection Program Report

1 January through 31 December 2023

Prepared By Teledyne Brown Engineering Environmental Services

Oyster Creek Generating Station Forked River, NJ 08731

April 2024 Intentionally left blank Table of Contents

I. Summary and Conclusions ................................................................................................ 3

II. Introduction ........................................................................................................................ 4 A. Objectives of the RGPP......................................................................................... 5 B. Implementation of the Objectives.......................................................................... 6 C. Program Description .............................................................................................. 7 D. Characteristics of Tritium (H-3) ............................................................................. 7

III. Program Description ......................................................................................................... 9 A. Sample Analysis .................................................................................................... 9 B. Data Interpretation................................................................................................. 9 C. Background Analysis ......................................................................................... 10

IV. Results and Discussion ................................................................................................ 12 A. Program Exceptions ............................................................................................ 12 B. Groundwater Results ........................................................................................... 12 C. Surface Water Results ........................................................................................ 13 D. Precipitation Water Results ................................................................................. 13 E. Summary of Results - Inter-laboratory Comparison Program ........................... 14 F. Leaks, Spills, and Releases ................................................................................ 14 G. Trends .................................................................................................................. 14 H. Ongoing Investigations ........................................................................................ 15 I. Remedial Actions Taken ..................................................................................... 15

V. References ...................................................................................................................... 16

Appendices

Appendix A Location Designation

Tables Table A-1 Radiological Groundwater Protection Program - Sampling Locations, Oyster Creek Generating Station, 2023 Figures Figure A-1 RGPP Sample Locations, Surface Water and Cape May Formation, Oyster Creek Generating Station, 2023

Figure A-2 RGPP Sample locations, Cohansey Formation, Oyster Creek Generating Station, 2023

Figure A-3 RGPP Sample locations, Cape May Groundwater Formation, Oyster Creek Generating Station, October 2023

Figure A-4 RGPP Sample locations, Cohansey Groundwater Formation, Oyster Creek Generating Station, October 2023 Security-Related Information: Detailed maps of the Oyster Creek Generating Station have been withheld from public disclosure under 10 CFR 2.390 and N.J.S.A. 47:1A-1.1

Appendix B Data Tables

Tables Table B-I.1 Concentrations of Tritium, Strontium, Gross Alpha and Gross Beta in Groundwater Samples Collected as Part of the Radiological Groundwater Protection Program, Oyster Creek Generating Station, 2023 Table B-I.2 Concentrations of Gamma Emitters in Groundwater Samples Collected as Part of the Radiological Groundwater Protection Program, Oyster Creek Generating Station, 2023 Table B-I.3 Concentrations of Hard- To- Detects in Groundwater Samples Collected as Part of the Radiological Groundwater Protection Program, Oyster Creek Generating Station, 2023 Table B-II.1 Concentrations of Tritium in Surface Water Samples Collected as Part of the Radiological Groundwater Protection Program, Oyster Creek Generating Station, 2023 Table B-II.2 Concentrations of Gamma Emitters in Surface Water Samples Collected as Part of the Radiological Groundwater Protection Program, Oyster Creek Generating Station, 2023

I. Summary and Conclusions A Radiological Groundwater Protection Program (RGPP) was conducted at the Oyster Creek Generating Station (OCGS) by Holtec Decommissioning International (HDI) for the period January 1, 2023 through December31, 2023.

This report includes groundwater and surface water samples collected from the environment in 2023. In 2023, 3 19 analyses were performed on 72 samples from 37 locations.

No fission or activation gamma emitting radionuclides were detected at any of the 34 groundwater well sample locations or 3 surface water locations analyzed during 2023.

In the case of tritium, HDI specified that the laboratory achieve a lower limit of detection 100 times lower than the drinking water limit specified by the United States Environmental Protection Agency (USEPA) (2,000 pCi/l versus 20,000 pCi/l).

Tritium was detected in groundwater samples with concentrations varying from <170 to 370 pCi/L. The well with the highest concentration was W-13.

Surface water samples were collected from 3 onsite monitoring locations during 2023. Tritium was not detected in any of the 6 samples .

Strontium-89 (Sr-89) and Strontium-90 (Sr-90) were not detected in any groundwater samples during 2023.

Gross Alpha and Gross Beta analyses in the dissolved and suspended fractions were performed on groundwater samples in 2023. There were 33 samples taken from 20 groundwater well locations. Gross Alpha (dissolved) was not detected in any sample. Gross Alpha (suspended) was detected in 2 samples and concentrations ranged from 2.6 to 3.5 pCi/L. Gross Beta (dissolved) was detected in 29 samples with a range of 1.2 to 9.5 pCi/L. Gross Beta (suspended) was detected in 8 samples and ranged from 2.1 to 12.2 pCi/L.

Hard-To- Detect (HTD) analyses were not performed any samples in 2023. These analyses are prompted by procedure EN-AA- 408- 4000 and would typically include americium-241 (Am-241), cerium-242 (Ce- 242), cerium-243/244 (Ce- 243/244),

plutonium-238 (Pu- 238), plutonium-239/240 (Pu- 239/240), uranium-234 (U-234),

uranium-235 (U-235), uranium-238 (U-238), iron -55 (Fe- 55) and nickel-63 (Ni-63).

II. Introduction On July 1st, 2019, Exelon Generation Company sold the Oyster Creek Nuclear Generating Station to Oyster Creek Environmental Protection, LLC (OCEP) and Holtec Decommissioning International, LLC (HDI) as the licensed operator, was completed. OCEP and HDI are wholly-owned subsidiaries of Holtec International.

The Oyster Creek Nuclear Generating Station consisted of a single boiling water reactor (BWR) and turbine generator rated at 650 megawatts of electricity. The Station operated under Nuclear Regulatory Commission (NRC) renewed facility operating license number DPR-16. Brackish water from Barnegat Bay is supplied to the circulating water system. The circulating water system is designed to supply a continuous flow of water from Barnegat Bay through the plant to remove the waste heat released by the power cycle in the Main Condenser. The circulating water system is comprised of the intake canal from Barnegat Bay to the plant, the Main Condenser Circulating Water System, the dilution plant, and the discharge canal to Barnegat Bay. The dilution plant portion of the system was designed to minimize the adverse effects of the thermal discharge on aquatic life in the discharge canal and Barnegat Bay.

The Station is located in the Atlantic Coastal Plain physiographic province.

Topography in the region of the Station is a slightly undulating coastal plain having low relief. The land surface gradually rises from sea level at Barnegat Bay, which is located east of the Station, to approximately 50 feet above mean sea level (AMSL) 2 miles inland. This region of the coastal plain has numerous tidal marshes and is incised by easterly flowing streams and creeks. Elevations at the Station property west of Route 9 range from approximately 0 to 15 feet AMSL immediately adjacent to the intake and discharge canals to slightly more than 30 feet AMSL in the northwest portion of the Station property. The 150- acre developed portion of the Site located within the "horseshoe" formed by the intake and discharge canals west of Route 9 has an approximate average elevation of 20 feet AMSL. In the immediate vicinity of the intake and discharge canals, the Station property slopes steeply down to the canal. The average elevation of the surface water level in the intake and discharge canals is approximately 1- foot AMSL. The ground surface is relatively level except for the steep slopes at areas adjacent to the intake and discharge canals.

The three shallowest stratigraphic units in the vicinity of the Oyster Creek area in descending order are the Cape May Formation, the Cohansey Formation, and the Kirkwood Formation. Some of the Station structures are constructed to depths of approximately 50 feet below ground surface (bgs). Excavations were completed from grade, through the fill, Cape May Formation, Upper Clay, and into the Cohansey Formation during construction. Consequently, the bottoms of some

Station structures are completed within the Cohansey Formation and some structures breach the Upper Clay.

The Cape May Formation regionally has an average thickness of 40 feet and at OCGS, the Cape May is described as a light gray to tan, medium- to fine- grained sand, with trace to some silt and occasional coarse sand. It is generally poorly compacted. The Cape May Formation varies from 0 to 21 feet in thickness based on historical boring logs. The variation principally is due to the varying amount of material excavated and replaced by fill during Station construction. When present, the thickness of the Cape May generally ranges from 15 to 20 feet thick. The base of the Cape May generally is defined by the presence of a dark clay unit referred to as the Upper Clay unit. The Upper Clay is a stiff to hard, gray, plastic organic clay containing inclusions (also described as lenses or partings) of dense fine sand with trace to some organic silt. The deposits of fine sand within the Upper Clay layer have high relative densities and occur as lenses or inclusions.

The Cohansey Formation is primarily composed of a light-colored, fine- to very coarse- grained quartzose sand with lenses of silt and clay. Although most borings at the Station do not penetrate the entire Cohansey Formation, this formation appears to be approximately 60 to 80 feet thick at OCGS. A clay sequence, referred to at the Station as the "Lower Clay", marks the base of the Cohansey, which generally is present to approximately 90 to 100 feet bgs. The lower clay is a dense gray medium- to fine- grained sand containing trace to some organic silt and layers or inclusions of very stiff to hard gray organic clay. The thickness of the lower clay is estimated to be approximately 10 to 20 feet in the vicinity of OCGS.

The Cohansey Formation is underlain by the Kirkwood Formation which consists of several stratigraphic units. The Kirkwood Formation is described as a medium- to fine-grained sand with trace silt. The thickness of this formation beneath the Station is unknown. The south domestic supply well terminates in the Kirkwood at a depth of 310 feet bgs. The Kirkwood thickness in Ocean County ranges from approximately 300 to 400 feet.

This Annual Radiological Groundwater Protection Program report covers those analyses performed by Teledyne Brown Engineering (TBE) and Microbac Laboratories (formerly Environmental Inc. Midwest Labs) on samples collected in 2023.

A. Objectives of the RGPP The long- term objectives of the RGPP are as follows:

Ensure that the site characterization of geology and hydrology provides an understanding of predominant ground water gradients based upon current site conditions

Identify site risk based on plant design and work practices Evaluate all structures, systems and components (SSC) that contain or could contain licensed material and for which there is a credible mechanism for the licensed material to reach groundwater Evaluate work practices that involve licensed material and for which there is a credible mechanism for the licensed material to reach groundwater Perform on-site monitoring to ensure timely detection of inadvertent radiological releases to ground water

Understand background concentrations of radioactive analytes outside of the REMP, as required Evaluate return/re-use of previously discharged radioactive effluents in gaseous or liquid effluents that are returned from the environment to the operating nuclear power facility Ensure controls are established for the selection, installation and retirement of monitoring wells Perform remediation protocols to prevent migration of licensed material off-site and to minimize decommissioning impacts Ensure that records of leaks, spills, remediation efforts are retained and retrievable to meet the requirements of 10 CFR 50.75(g)

Ensure periodic communications are held on the RGPP with the designated State/Local officials Ensure timely verbal and written reporting occurs if there is an inadvertent release of licensed materials to the soil, groundwater or surface water Document and report all applicable RGPP data Identify and resolve deficiencies via the Decommissioning Corrective Action Program Perform program oversight to ensure effective implementation of the voluntary RGPP

B. Implementation of the Objectives The objectives identified have been implemented at the Oyster Creek Generating Station through compliance with approved procedures EN-AA-408- 4000, Radiological Groundwater Protection Program Implementation, and site specific procedure EN-OC-408- 4160, RGPP Reference Material, for Oyster Creek Generating Station.

C. Program Description Samples for the OCGS site were collected by Normandeau Associates, Inc.

This section describes the general collection methods used to obtain environmental samples for the OCGS RGPP in 2023. Sample locations can be found in Table A-1, Appendix A.

1. Sample Collection Both groundwater and surface water are collected, managed, transported and analyzed in accordance with approved procedures. Sample locations, sample collection frequencies and analytical frequencies are controlled in accordance with approved station procedures. Contractor and/or station personnel are trained in the collection, preservation management, and shipment of samples, as well as in documentation of sampling events. In addition, Normandeau procedure ER-OGS-18 as well as the New Jersey Field Sampling Procedures Manual are utilized during field collection activities.

2. Sample Analyses Samples are analyzed as specified by approved analytical procedures .

These procedures include industry standards, such as the EPA Procedures for Measuring Radioactivity in Drinking Water, DOEs EML Procedures Manual (HASL 300), or by Teledyne proprietary methods.

3. Quality Control Analytical laboratories are subject to internal quality assurance programs, industry cross-check programs, nuclear industry audits, as well as being certified by the State of New Jersey (Certification ID #RN003).

4. Data Interpretation Station personnel review and evaluate all analytical data deliverables as data is received. Analytical data results are reviewed by both station personnel and independent consultants, including a hydrogeologist, for adverse trends or changes to hydrogeologic conditions. Duplicate samples are provided to and data is shared with the New Jersey Department of Environmental Protection - Bureau of Nuclear Engineering.

D. Characteristics of Tritium (H-3)

Tritium (chemical symbol H- 3) is a radioactive isotope of hydrogen. The most common form of tritium is tritium oxide, which is also called "tritiated water."

The chemical properties of tritium are essentially those of ordinary hydrogen.

Tritiated water behaves the same as ordinary water in both the environment and the body. Tritium can be taken into the body by drinking water, breathing air, eating food, or absorption through the skin. Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the body. Tritium is excreted primarily through urine with a clearance rate characterized by an effective biological half-life of about 10 days.

Tritium is produced naturally in the upper atmosphere when cosmic rays strike air molecules. Tritium is also produced during nuclear weapons explosions, as a by-product in reactors producing electricity, and in special production reactors. Also, tritium was released into the atmosphere from Chernobyl in 1986. Like normal water, tritiated water is colorless and odorless. Tritiated water behaves chemically and physically like non- tritiated water in the subsurface, and therefore tritiated water will travel at the same velocity as the average groundwater velocity.

Tritium has a half-life of approximately 12.3 years. It decays spontaneously to helium-3 (He-3). This radioactive decay releases a beta particle (18.6 keV low- energy electron). The radioactive decay of tritium is the source of the health risk from exposure to tritium. Tritium emits very weak radiation and the associated dose is generally uniform but is dependent on the water content of the specific tissue.

III. Program Description A. Sample Analysis This section describes the general analytical methodologies used by TBE to analyze the environmental samples for radioactivity for the Oyster Creek Generating Station RGPP.

In order to achieve the stated objectives, the current program includes the following analyses for groundwater and surface water:

1. Gamma emitters

2. Tritium

3. Gross Alpha (Dissolved and Suspended) and Gross Beta (Dissolved and Suspended)

The following parameters are conditionally analyzed in accordance with Attachment 3 (Sampling and Analysis Protocols) of procedure EN-AA- 408-4000:

1. Strontium-89 and Strontium-90

2. Selected transuranics

3. Iron-55

4. Nickel- 63

B. Data Interpretation The radiological data collected prior to Oyster Creek Generating Station becoming operational, as well as background data from publicly available databases, were used as a baseline with which these operational data were compared. For the purpose of this report, Oyster Creek Generating Station was considered operational at initial criticality. Several factors were important in the interpretation of the data:

1. Lower Limit of Detection and Minimum Detectable Concentration The lower limit of detection (LLD) is defined as the smallest concentration of radioactive material in a sample that would yield a net count (above background) that would be detected with only a 5% probability of falsely concluding that a blank observation represents a "real" signal. The LLD is intended as a before the fact (a priori) estimate of a system (including instrumentation, procedure and sample type) and not as an after the fact (a posteriori) criterion for the presence of activity. All analyses were designed to achieve the required OCGS detection capabilities for environmental sample analysis.

The minimum detectable concentration (MDC) is defined as the smallest concentration of radioactive material in a sample that would yield a net count (above background) that would be detected with only a 5%

probability of falsely concluding that a blank observation represents a "real" signal as an after the fact estimate of the presence of activity.

2. Laboratory Measurements Uncertainty The estimated uncertainty in measurement of tritium in environmental samples is frequently on the order of 50% of the measurement value.

Statistically, the exact value of a measurement is expressed as a range with a stated level of confidence. The convention is to report results with a 95% level of confidence. Uncertainty comes from factors such as calibration standards, sample volume/weight measurements, or sampling uncertainty. The uncertainty of a measurement created by statistical process (counting error) is reported as well as all sources of error (Total Propagated Uncertainty or TPU). Each result has two values calculated.

Each counting result is reported and then followed with a plus or minus

(+/-) result of the estimated sample standard deviation (as TPU) that is obtained by propagating all sources of analytical uncertainty in measurements. Analytical uncertainties are reported at the 95%

confidence level.

C. Background Analysis

1. Background Concentrations of Tritium The purpose of the following discussion is to summarize background measurements of tritium in various media performed by others.

Additional detail may be found by consulting references.

a. Tritium Production Tritium is created in the environment from naturally-occurring processes both cosmic and subterranean, as well as from anthropogenic (i.e., man- made) sources. In the upper atmosphere, cosmogenic tritium is produced from the bombardment of stable nuclides and combines with oxygen to form tritiated water, which will then enter the hydrologic cycle. Below ground, lithogenic tritium is produced by the bombardment of natural lithium present in crystalline rocks by neutrons produced by the radioactive decay of naturally abundant uranium and thorium. Lithogenic production of tritium is usually negligible compared to other sources due to the limited abundance of lithium in rock. The lithogenic tritium is introduced directly to groundwater.

A major anthropogenic source of tritium and Sr-90 comes from the former atmospheric testing of thermonuclear weapons. Levels of tritium in precipitation increased significantly during the 1950s and peaked in 1963 with the signing of the limited test ban treaty. The Canadian heavy water nuclear power reactors, other commercial power reactors, nuclear research and weapons production continue to influence tritium concentrations in the environment. Also, tritium was released into the atmosphere from Chernobyl in 1986.

b. Precipitation Data Precipitation samples are routinely collected at stations around the world for the analysis of tritium and other radionuclides. One publicly available database that provides tritium concentrations in precipitation is the USEPAs RadNet database. RadNet provides tritium precipitation concentration data for samples collected at stations throughout the U.S. from 1978 up to and including 1996.

Tritium concentrations in precipitation in New Jersey from 1978 through 1996 have ranged from 600 pCi/L in 1979 to 0 pCi/L in 1996, with an average of 185 pCi/L. Tritium concentrations in wells may still be above the 2000 pCi/l detection limit from the external causes described above. Water from previous years and decades is naturally captured in groundwater, so some well water sources today are affected by the surface water from the 1960s that was elevated in tritium.

c. Surface Water Data Tritium concentrations are routinely measured in surface water bodies, including Oyster Creek and the Delaware River. New Jersey surface water data between 1978 and 1998 averaged 185 pCi/L.

The USEPA RadNet surface water data typically has a reported Combined Standard Uncertainty of 2 standard deviations. This corresponds to a +/- 36 to +/-100 pCi/L confidence bound on each given reported measurement so that the typical surface water background data provided by RadNet may be subject to measurement uncertainty of up to 100 pCi/L.

The radio- analytical laboratory counts tritium results to an HDI-specified LLD of 200 pCi/L with a typical uncertainty of +/-100 pCi/L. Therefore, sample results reported by TBE near this LLD cannot be distinguished from natural background concentrations in surface water.

IV. Results and Discussion

A. Program Exceptions There were no program exceptions in 2023. All samples required by station procedures were collected as required.

B. Groundwater Results Samples were collected from on- site locations in accordance with the station radiological groundwater protection program. As reported in the latest Hydrogeologic Investigation Report, groundwater flow in shallow aquifers is towards the intake and discharge canals.

Tritium Samples from 34 locations were analyzed for tritium activity. Tritium was detected in 14 of 63 samples. The values ranged from <LLD to 370 pCi/L.

The well with the highest concentration was W-13. (Table B -I.1, Appendix B)

Strontium Samples collected from onsite wells are analyzed for hard- to-detect (HTD) isotopes, including strontium to characterize the source of any contaminant. Per station procedures, ongoing surveillance for HTD isotopes is required after initial negative findings to ensure a new source of contamination is not present.

Strontium-89 and Strontium-90 were not detected in any location sampled in 2023. (Table B -I.1, Appendix B)

Gross Alpha and Gross Beta (dissolved and suspended)

Gross Alpha and Gross Beta analyses in the dissolved and suspended fractions were performed on groundwater samples in 2023. There were 33 samples taken from 20 groundwater well locations. Gross Alpha (dissolved) was not detected in any sample. Gross Alpha (suspended) was detected in 2 samples and concentrations ranged from 2.6 to 3.5 pCi/L. Gross Beta (dissolved) was detected in 29 samples with a range of 1.2 to 9.5 pCi/L.

Gross Beta (suspended) was detected in 8 samples and ranged from 2.1 to 12.2 pCi/L. (Table B-I.1, Appendix B)

Gamma Emitters Naturally occurring K-40 was detected in one sample at a concentration of 110 pCi/L. No other gamma- emitting nuclides were detected activation or fission gamma- emitting nuclides were detected in any groundwater sample in 2023. (Table B -I.2, Appendix B).

Hard-To-D etect Hard-To- Detect (HTD) analyses are conditionally analyzed in accordance with Attachment 3 (Sampling and Analysis Protocols) of Procedure EN- AA- 408-4000 and were not performed in 2023. (Table B- I.3, Appendix B)

C. Surface Water Results Samples were collected from 3 on- site locations in accordance with the station radiological groundwater protection program. Analytical results and anomalies are discussed below:

Tritium Samples from 3 locations were analyzed for tritium activity. No H-3 was detected in any sample. ( Table B-II.1, Appendix B)

Gross Alpha and Gross Beta (dissolved and suspended)

Gross Alpha and Gross Beta analyses in the dissolved and suspended fractions are not required on a routine basis and were not analyzed in 2023.

Gamma Emitters Naturally occurring K-40 was detected in one sample at a concentration of 173 pCi/L. No other gamma- emitting nuclides were detected in surface water samples during 2023. (Table B-II.2, Appendix B)

Hard-To- Detect Hard-To- Detect analyses are not required on a routine basis and were not analyzed in 2023.

D. Precipitation Water Results The precipitation recapture study at Oyster Creek was terminated in 2019 based upon the following criteria:

1) Historic on-site groundwater tritium concentrations do not appear to have been influenced by recapture.

2) During the nine years of sampling precipitation on a quarterly frequency from four (4) indicator and one (1) control location, there was only one (1) detection of tritium greater than the MDA (0.63% detection rate). That detection was close to the detection limit, and it cannot be ruled out that this was a contamination event (no error measurement is provided in this data table).

Although a continuous release of gaseous tritium has continued from tritiated water vapor from evaporation from the refuel floor reactor cavity, the cessation of power generation in September 2018 ended the production of tritium at the

site. Since tritium is created by activation of hydrogen in the reactor during fission, the quantity of tritium in the tanks and systems of the plant has only decreased since shutdown in 2018. The addition of demineralized water to the spent fuel pool/reactor cavity during decommissioning activities has diluted the tritium I the plant water. The tritium concentration in the plant-contaminated water systems has dropped by ~ 44% since decommissioning efforts began.

Flow from the main stack has also decreased by ~60% since power operation ceased as ventilation for radwaste, reactor, and turbine buildings are no longer operating and building heat loads have decreased. There is also much less contaminated water in the plant, therefore the ventilation system is transporting far less tritiated water vapor up the stack.

Monthly releases are calculated based on the existing tritium concentration of this water, typical release rates during operation were ~30,000 µCi/day but the current release rate is ~1,600 µCi/day. The combination of factors (lower inventory, reduced concentration, and reduced stack flow) produces approximately 5% of the release as compared to operation.

In summary, with the low detection rate while the plant was operational and the factors reducing detection probability since cessation of operation, it would be improbable to detect tritium in recapture samples collected under current plant conditions.

E. Summary of Results - Inter-Laboratory Comparison Program Inter-Laboratory Comparison Program results for TBE and Microbac (formerly Environmental Inc. Midwest Labs) are presented in the 2023 Oyster Creek AREOR. This report is part of the AREOR.

F. Leaks, Spills, and Releases There were no leaks or spills during 2023.

G. Trends A groundwater remedial program was completed in early 2009 due to the discover of leaking underground pipelines associated with the Condensate Storage Tank (CST). The damaged underground piping was replaced in late April 2009 through August 2009. A groundwater extraction well was installed on November 17, 2010, and continued to operate to remove residual tritium concentrations in the area of the CST as well as control the groundwater elevation on the western side of the protected area. Groundwater extraction ceased in October 2019 with NJDEP concurrence. Overall, the station has seen a decreasing trend in tritium values to the point where groundwater tritium is in an order of magnitude below the ODCM LLD (2,000 pCi/L).

H. Ongoing Investigations To date, GHD completed three (3) five-year hydrogeologic investigation reports for the Station (April 2011, January 2017 and September 2022). The referenced reports summarized station activities since the implementation of the NEI groundwater initiative, including changes at the site as well as RGPP sampling activities and groundwater flow. The results of these assessments can be found in References 1, 2 and 3.

I. Remedial Actions Taken

1. Compensatory Actions (Historic)

Active remediation of tritium in groundwater due to the Condensate Storage Tank (CST) spills that occurred in 2009 was initiated in October 2010. Due to the decrease in groundwater tritium as a result of the remediation project, continuous remediation was ceased in 2019. The Oyster Creek ODCM has provision to re- start remediation from this well, if necessary, via either continuous or batch discharge methods.

2. Installation of Monitoring Wells (Historic)

The following wells were installed in 2010 to better characterize and monitor the tritium plume and site hydrology:

Well Number Formation Well Installation Date W-58 I Cohansey July W-59 I Cohansey March W-60 I Cohansey July W-61 I Cohansey July W-62 Cape May March W-63 I Cohansey July W-64 Cape May March W-65 Cape May March W-66 I Cohansey July W-67 Cape May March W-68 I Cohansey July W-69 I Cohansey July W-70 I Cohansey July W-71 Cape May August W-72 Cape May August W-73 Pumping well Cohansey October

3. Actions to Recover/Reverse Plumes (Historic)

Oyster Creek Generating Station addressed the tritium in groundwater through continuous pumping of groundwater from of W-73 to the intake structure. Remediation of groundwater was terminated in 2019 with State of New Jersey concurrence.

V. References

1. GHD, Hydrogeologic Investigation Report, Fleetwide Assessment, Oyster Creek Generating Station, Forked River, New Jersey, September, 2022

2. Conestoga Rovers and Associates, Hydrogeologic Investigation Report, Fleetwide Assessment, Oyster Creek Generating Station, Forked River, New Jersey, 2016

3. Conestoga Rovers and Associates, Hydrogeologic Investigation Report, Fleetwide Assessment, Oyster Creek Generating Station, Forked River, New Jersey, April 2011

4. Conestoga Rovers and Associates, Site Investigation Report, Oyster Creek Generating Station, Forked River, New Jersey, October 2009

5. Conestoga Rovers and Associates, Remedial Investigation Workplan, Oyster Creek Generating Station, Forked River, New Jersey, 2009

APPENDIX A

LOCATION DESIGNATION

Intentionally left blank TABLE A-1: Radiological Groundwater Protection Program - Sampling Locations, Oyster Creek Generating Station, 2023

Oyster Creek Generating Station RGPP Sample Point List

Sample Well GPS RGPP Aquifer or Identification Location Coordinates Depth Sample Tritium Water Body Number (Northing/Easting) (ft) Point Alert Value Monitored Designation MW-1A-2A SW of MFOT 357380.76 Moat 575043.44 24.0 D 2,000 pCi/L Cape May

MW-1I-1A Roadway - NW 357598.17 of TWST 574412.70 19.0 D 2,000 pCi/L Cape May

MW-1I-2A Roadway - SE 357574.80 of TWST 574493.50 17.5 D 2,000 pCi/L Cape May

MW-15K-1A Roadway - 357297.90 Intake 574469.50 19.0 D 2,000 pCi/L Cape May

MW-16D Yard - W of 357573.30 MAC Building 574746.50 25.0 D 2,000 pCi/L Cape May

SW-1 Intake Canal N/A N/A SW 2,000 pCi/L Surface Water

SW-2 RT 9 South Bridge N/A N/A SW 2,000 pCi/L Surface Water

SW-3 Fire Pond N/A N/A SW 2,000 pCi/L Surface Water

W-3 Intake - Access 357173.00 24.0 Road 574499.10 D 2,000 pCi/L Cape May

W-4 Intake - Access 357176.40 Cohansey Road 574497.70 55.0 D 2,000 pCi/L

W-4A SE of OCAB 356913.30 Cohansey Building 575387.10 50.0 B 2,000 pCi/L NW Yard area, 357510.95 W-5 near Fire Water 574374.05 20.5 D 2,000 pCi/L Cape May Tank W-6 NW Yard - near 357514.02 Fire Water Tank 574373.77 52.0 D 2,000 pCi/L Cohansey

W-9 Roadway - NE 357289.29 Cape May of SAS Building 574892.74 20.0 D 2,000 pCi/L

W-10 NW of SAS 357286.29 Cape May Building 574890.61 60.0 D 2,000 pCi/L

W-12 Yard - NW of 357669.10 Cape May DWPC Building 574755.60 20.0 D 2,000 pCi/L W-13 Yard - NW of 357666.00 Cape May DWPC Building 574755.90 50.0 D 2,000 pCi/L W-14 Yard - SW of 357702.41 Cape May Warehouse 575018.75 53.0 D 2,000 pCi/L W-15 Yard - SW of 357705.83 Cape May Warehouse 575017.70 20.0 D 2,000 pCi/L

W-16 Yard - E of 357967.26 Cape May LLRW 574933.03 20.0 D 2,000 pCi/L South of TB 357128.94 W-24 W of old 574650.77 19.0 D 2,000 pCi/L Cape May Machine Shop TABLE A-1: Radiological Groundwater Protection Program - Sampling Locations, Oyster Creek Generating Station, 2023

Oyster Creek Generating Station RGPP Sample Point List

Sample Well GPS RGPP Aquifer or Identification Location Coordinates Depth Sample Tritium Water Body Number (Northing/Easting) (ft) Point Alert Value Monitored Designation South of TB 357196.14 W-34 W of old 574649.43 40.0 D 2,000 pCi/L Cohansey Machine Shop MW-52 Near Intake 357400.90 Cape May Structure 574353.00 20.0 D 2,000 pCi/L

MW-53 Near end of CW 357272.80 Cape May discharge piping 574447.60 20.0 D 2,000 pCi/L MW-54 Near Intake 357276.20 Cape May Structure 574311.70 20.0 E 2,000 pCi/L Between CST 357354.88 MW-55 and Intake 574440.07 30.0 E 2,000 pCi/L Cape May Structure

MW-56I By NaOCl tanks 357305.30 574465.50 52.0 E 2,000 pCi/L Cohansey

MW-57I Near Intake 357343.71 Cohansey Structure 574373.89 50.0 E 2,000 pCi/L MW-59I Intake Roadway 357422.14 Cohansey

- NW of CST 574406.38 44.0 D 2,000 pCi/L Between CST 357328.64 MW-61I and Intake 574444.45 72.0 E 2,000 pCi/L Cohansey Structure MW-62 NW Corner of 357467.93 Cape May Turbine Bldg 574524.10 25.0 D 2,000 pCi/L

MW-64 Near Intake 357343.96 Cape May Structure 574377.88 25.0 E 2,000 pCi/L

MW-65 Intake Roadway 357421.00 Cape May

- NW of CST 574402.55 25.0 D 2,000 pCi/L MW-67 West side of 357401.99 Cape May Turbine Bldg 574540.38 25.0 E 2,000 pCi/L MW-68I SE of Reactor 357323.83 2,000 pCi/L Cohansey Bldg 574897.64 100.0 D MW-71 S of Reactor 357365.52 Cape May Bldg 574841.89 25.0 D 2,000 pCi/L

MW-72 N of Reactor 357549.87 Cape May Bldg 574788.52 25.0 D 2,000 pCi/L

KEY: B = Background D = Detection E = Elevated I = Idle/Standby P = Plume L = Long-Term Shutdown SW = Surface Water Figure A-1 RGPP Sample Locations Surface Water and Cape May Formation Oyster Creek Generating Station, 2023 Figure A-2 RGPP Sample Locations Cohansey Formation Oyster Creek Generating Station, 2023 Figure A-3 RGPP Sample Locations Cape May Groundwater Formation Oyster Creek Generating Station, October 2023 Figure A-4 RGPP Sample Locations Cohansey Groundwater Formation Oyster Creek Generating Station, October 2023 APPENDIX B

D AT A T AB L E S Intentionally left blank

TABLE B-I.1 CONCENTRATIONS OF TRITIUM, STRONTIUM, GROSS ALPHA, AND GROSS BETA IN GROUNDWATER SAMPLES COLLECTED AS PART OF THE RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM, OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE DATE H-3 Sr-89 Sr-90Gr-A (Dis) Gr-A (Sus) Gr-B (Dis) Gr-B (Sus)

MW-1A-2A 04/25/23 < 193 MW-1I-1A 04/25/23 < 194 < 9.1 < 0.9 < 0.5 < 1.3 3.6 +/- 0.8 < 1.5 MW-1I-1A 10/18/23 < 174 MW-1I-2A 04/20/23 < 178 < 8.7 < 0.9 < 0.4 < 1.2 1.5 +/- 0.6 < 1.5 MW-1I-2A 10/17/23 < 183 MW-15K-1A 01/31/23 < 0.3 < 1.0 MW-15K-1A 04/18/23 < 195 < 6.9 < 0.9 < 0.5 < 1.4 2.5 +/- 0.7 < 1.6 MW-15K-1A 10/17/23 < 178 < 5.5 < 0.7 < 0.5 < 0.9 3.0 +/- 0.7 < 1.6 MW-16D 04/25/23 < 190 < 4.0 < 0.7 < 1.3 < 1.1 7.1 +/- 1.4 < 1.5 MW-16D 04/25/23 Duplicate < 192 < 4.0 < 0.8 < 1.3 < 1.1 7.5 +/- 1.4 < 1.5 MW-16D 04/25/23 Microbac < 162 < 0.7 < 0.5 < 2.5 (1)

MW-16D 10/18/23 < 185 MW-16D 10/18/23 Duplicate < 182 MW-16D 10/18/23 Microbac < 171 MW-52 04/20/23 < 189 MW-53 04/18/23 < 197 MW-54 04/20/23 195 +/- 123 MW-55 04/18/23 < 189 < 8.0 < 0.9 < 1.1 < 1.3 3.2 +/- 1.1 < 1.5 MW-55 10/17/23 < 184 < 5.1 < 0.7 < 0.4 < 1.2 1.2 +/- 0.6 < 1.6 MW-56I 04/18/23 < 192 < 9.2 < 0.8 < 0.6 < 1.0 6.0 +/- 0.9 < 1.7 MW-56I 10/17/23 < 174 < 6.6 < 0.6 < 0.5 < 1.1 2.6 +/- 0.7 < 1.6 MW-57I 04/20/23 < 190 < 5.6 < 0.9 < 0.8 3.5 +/- 1.6 6.9 +/- 1.1 4.1 +/- 1.5 MW-57I 10/17/23 < 190 < 5.3 < 0.6 < 0.6 < 1.5 6.7 +/- 0.9 < 1.8 MW-59I 04/18/23 208 +/- 128 < 7.2 < 0.9 < 0.5 < 1.1 1.7 +/- 0.7 < 1.7 MW-59I 10/17/23 < 190 MW-61I 04/18/23 < 191 < 8.0 < 0.8 < 0.6 < 1.2 < 1.1 4.2 +/- 1.4 MW-61I 10/17/23 < 195 MW-62 04/25/23 < 193 < 7.3 < 0.9 < 1.1 < 1.4 9.5 +/- 1.4 3.0 +/- 1.4 MW-62 10/17/23 < 180 MW-64 04/20/23 < 189 < 8.5 < 0.9 < 0.4 < 1.8 1.8 +/- 0.7 6.9 +/- 1.8 MW-64 04/20/23 Duplicate < 190 < 9.2 < 0.9 < 0.3 < 3.1 7.0 +/- 0.9 12.2 +/- 2.4 MW-64 04/20/23 Microbac < 162 < 0.8 < 0.5 < 1.3 (1)

MW-64 10/17/23 < 180 MW-64 10/17/23 Duplicate < 189 MW-64 10/17/23 Microbac < 171 MW-65 01/31/23 < 1.0 2.6 +/- 1.3 MW-65 04/18/23 < 193 < 5.5 < 0.9 < 1.2 < 1.1 4.3 +/- 1.3 < 1.7 MW-65 10/17/23 < 181 < 4.3 < 0.6 < 1.1 < 0.9 6.8 +/- 1.2 2.2 +/- 1.2 MW-67 04/25/23 < 191 < 4.2 < 0.7 < 0.6 < 1.1 5.3 +/- 1.0 < 1.7 MW-67 10/17/23 < 180 < 6.4 < 0.9 < 0.6 < 0.9 4.9 +/- 0.9 < 1.6 MW-71 04/25/23 < 189 < 4.6 < 0.7 < 0.7 < 1.0 3.3 +/- 1.0 < 1.7 MW-71 10/18/23 < 181 MW-72 04/25/23 < 192 < 9.2 < 1.0 < 0.5 < 1.0 2.2 +/- 0.8 < 1.7 MW-72 04/25/23 Duplicate < 193 < 5.9 < 1.0 < 0.5 < 1.0 2.4 +/- 0.8 < 1.7 MW-72 04/25/23 Microbac < 162 < 0.7 < 0.5 < 0.2 (1)

(1) Total Gross Alpha result reported (not dissolved/suspended)

TABLE B-I.1 CONCENTRATIONS OF TRITIUM, STRONTIUM, GROSS ALPHA, AND GROSS BETA IN GROUNDWATER SAMPLES COLLECTED AS PART OF THE RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM, OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA COLLECTION SITE DATE H-3 Sr-89 Sr-90Gr-A (Dis) Gr-A (Sus)Gr-B (Dis) Gr-B (Sus)

MW-72 10/18/23 < 178 W-1A 04/26/23 < 192 W-3 01/31/23 < 0.3 < 1.2 W-3 04/20/23 < 179 < 9.0 < 1.0 < 0.4 < 1.2 1.7 +/- 0.7 < 1.5 W-3 10/17/23 < 179 W-4 04/20/23 < 178 W-4A 04/26/23 < 181 W-5 04/24/23 Duplicate < 178 < 9.6 < 0.9 < 0.4 < 1.2 2.5 +/- 0.7 < 1.5 W-5 04/24/23 Microbac < 162 < 0.8 < 0.6 < 1.3 (1)

W-5 04/24/23 Microbac Dup < 162 < 0.7 < 0.5 < 1.3 (1)

W-5 04/24/23 < 179 < 9.7 < 0.9 < 0.5 < 1.2 2.8 +/- 0.8 < 1.5 W-5 10/17/23 < 174 W-5 10/17/23 Duplicate < 175 W-5 10/17/23 Microbac < 171 W-6 04/25/23 < 179 W-9 04/25/23 < 179 < 7.0 < 0.9 < 1.0 < 1.2 4.2 +/- 1.1 2.1 +/- 1.1 W-9 10/18/23 < 177 W-10 04/25/23 < 180 W-12 04/25/23 < 179 < 7.5 < 0.9 < 0.5 < 1.6 1.3 +/- 0.7 7.5 +/- 1.5 W-12 10/18/23 < 170 W-13 04/25/23 370 +/- 129 W-14 04/25/23 < 182 W-15 04/25/23 < 181 W-16 04/25/23 < 180 W-24 04/26/23 < 182 W-34 04/26/23 < 180 < 9.5 < 0.9 < 0.7 < 1.1 2.5 +/- 0.8 < 1.5 W-34 10/16/23 < 195

(1) Total Gross Alpha result reported (not dissolved/suspended)

TABLE B-II.1 CONCENTRATIONS OF TRITIUM IN SURFACE WATER SAMPLES COLLECTED AS PART OF THE RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM, OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER + 2 SIGMA

COLLECTION SITE DATEH-3 SW -1 04/24/23 < 193 SW -1 10/16/23 < 185 SW -2 04/24/23 < 192 SW -2 10/16/23 < 179 SW -3 04/24/23 < 192 SW -3 10/16/23 < 181 TABLE B-II.2 CONCENTRATIONS OF GAMMA EMITTERS IN SURFACE WATER SAMPLES COLLECTED AS PART OF THE RADIOLOGICAL GROUNDWATER PROTECTION PROGRAM, OYSTER CREEK GENERATING STATION, 2023 RESULTS IN UNITS OF PCI/LITER +/- 2 SIGMA

COLLECTION SITE DATE Be-7 K-40 Mn-54 Co-58 Fe-59 Co-60 Zn-65 Zr-95 Cs-134Cs-137 SW-1 04/24/23 < 44 173 +/- 72 < 5 < 5 < 10 < 7 < 8 < 9 < 5 < 5 SW-2 04/24/23 < 58 < 134 < 6 < 8 < 10 < 6 < 13 < 12 < 6 < 9 SW-3 04/24/23 < 61 < 121 < 7 < 7 < 13 < 8 < 8 < 12 < 6 < 6 Intentionally left blank