ML031470204

Annual Radiological Environmental Operating Report, January 1, 2002 Through December 31, 2002, Table of Contents Through Table 6

ML031470204
Person / Time
Site:	Davis Besse
Issue date:	04/30/2003
From:	FirstEnergy Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation
References
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Download: ML031470204 (62)

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ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT Davis-Besse Nuclear Power Station January 1, 2002 through December 31, 2002 Davis-Besse Nuclear Power Station April 2003

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report TABLE OF CONTENTS Title Page List of Tables iv List of Figures vi Executive Summary viii INTRODUCTION Fundamentals I Radiation and Radioactivity 2 Interaction with Matter 3 Quantities and Units of Measurement 5 Sources of Radiation 7 Health Effects of Radiation 9 Health Risks 10 Benefits of Nuclear Power 11 Nuclear Power Production 11 Station Systems 16 Reactor Safety and Summary 19 Radioactive Waste 19 Description of the Davis-Besse Site 22 References 24 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM Introduction 26 Preoperational Surveillance Program 26 Operational Surveillance Program Objectives 27 Quality Assurance 27 Program Description 28 Sample Analysis 32 Sample History Comparison 34 ilI

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Title Page RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM (continued) 2002 Program Anomalies 36 Atmospheric Monitoring 38 TerTestrial Monitoring 44 Aquatic Monitoring 56 Direct Radiation Monitoring 68 Conclusion 79 References 79 RADIOACTIVE EFFLUENT RELEASE REPORT Protection Standards 82 Sources of Radioactivity Released 82 Processing and Monitoring 83 Exposure Pathways 84 Dose Assessment 85 Results 86 Regulatory Limits 87 Effluent Concentration Limits 88 Average Energy 88 Measurements of Total Activity 88 Batch Releases 89 Sources of Input Data 90 Doses to Public Due to Activities Inside the Site Boundary 90 Inoperable Radioactive Effluent Monitoring Equipment 91 Changes to The ODCM and PCP 91 Borated Water Storage Tank Radionuclide Concentrations 91 LAND USE CENSUS Program Design 110 Methodology 110 Results 111 ii

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Title Page NON-RADIOLOGICAL ENVIRONMENTAL PROGRAMS Meteorological Monitoring 116 On-site Meteorological Monitoring 117 Land and Wetlands Management 132 Water Treatment Plant Operation 133 Chemical Waste Management 137 Other Environmental Regulating Acts 138 Other Environmental Programs 140 APPENDICES Appendix A: Interlaboratory Comparison Program Results 142 Appendix B: Data Reporting Conventions 162 Appendix C: Effluent Concentration Limit of Radioactivity in Air and Water 164 Above Natural Background in Unrestricted Areas Appendix D: REMP Sampling Summary 166 iii

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report List of Tables Table Page Title Number Number Risk Factors: Estimated Decrease in Average Life Expectancy 1 10 Sample Codes and Collection Frequencies 2 30 Sample Collection Summary 3 31 Radiochemical Analyses Performed on REMP Samples 4 33 Air Monitoring Locations 5 40 Milk Monitoring Location 6 45 Groundwater Monitoring Locations 7 47 Broadleaf Vegetation and Fruit Locations 8 48 Animal/Wildlife Feed Locations 9 49 Wild and Domestic Meat Locations 10 50 Soil Locations 11 52 Treated Surface Water Locations 12 58 Untreated Surface Water Locations 13 61 Shoreline Sediment Locations 14 62 Fish Locations 15 64 Thermoluminescent Dosimeter Locations 16 70 Gaseous Effluents - Summation of All Releases 17 92 Gaseous Effluents - Ground Level Releases - Batch Mode 18 93 Gaseous Effluents - Ground Level Releases - Continuous Mode 18 94 Gaseous Effluents - Mixed Mode Releases - Batch Mode 19 96 Gaseous Effluents - Mixed Mode Releases - Continuous Mode 19 97 Liquid Effluents - Summation of All Releases 20 99 Liquid Effluents - Nuclides Released - Batch Releases 21 100 Liquid Effluents - Nuclides Released - Continuous Releases 21 102 Solid Waste and Irradiated Fuel Shipments 22 104 Doses Due to Gaseous Releases for January through December 2002 23 107 Doses Due to Liquid Releases for January through December 2002 24 108 Annual Dose to The Most Exposed (from all pathways) Member of The Public 2002 25 109 Closest Exposure Pathways Present in 2002 26 113 iv

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Table Page Title Number Number Closest Exposure Pathways in 2002 26 114 Pathway Locations and Corresponding Atmospheric Dispersion (X/Q) and Deposition (D/Q) Parameters 27 115 Summary of Meteorological Data Recovery for 2002 28 121 Summary of Meteorological Data Measured for 2002 29 122 Joint Frequency Distribution by Stability Class 30 127 v

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report List of Figures Figure Page Description Number Number The Atom 1 1 Principal Decay Scheme of the Uranium Series 2 3 Range and Shielding of Radiation 3 4 Sources of Exposure to the Public 4 8 Fission Diagram 5 12 Fuel Rod, Fuel Assembly, Reactor Vessel 6 13 Station Systems 7 15 Dry Fuel Storage Module Arrangement 8 21 Map of Area Surrounding Davis-Besse 9 22 2002 Airborne Particulate Gross Beta 10 39 Air Sample Site Map 11 41 Air Sample 5-mile Map 12 42 Air Sample 25-mile Map 13 43 Gross Beta Groundwater 1982-2002 14 46 Cs-137 in Soil 1972-2002 15 51 Terrestrial Site Map 16 53 Terrestrial 5-mile Map 17 54 Terrestrial 25-mile Map 18 55 Gross Beta in Treated Surface Water 1977-2002 19 57 Gross Beta Concentration in Untreated Surface Water 1972-2002 20 60 Gross Beta Fish 1972-2002 21 63 Aquatic Site Map 22 65 Aquatic 5-mile Map 23 66 Aquatic 25-mile Map 24 67 Gamma Dose for Environmental TLDs 1973 - 2002 25 69 TLD Site Map 26 76 TLD 5-mile Map 27 77 TLD 25-mile Map 28 78 Exposure Pathways 29 85 vi

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Figure Page Description Number Number Land Use Census Map 31 112 Wind Rose Annual Average lOOM 32 124 Wind Rose Annual Average 75M 33 125 Wind Rose Annual Average lOM 34 126 Water Treatment Plant Schematic 35 134 vii

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Executive Summary The Annual Radiological Environmental Operating Report (AREOR) is a detailed report on the Environmental Monitoring Programs conducted at the Davis-Besse Nuclear Power Station from January 1 through December 31, 2002. This report meets all of the requirements in Regulatory Guide 4.8, Davis-Besse Technical Specifications '6.9.1.10, and Davis-Besse Offsite Dose Calcu-lation Manual (ODCM) Section 7.1. Reports included are the Radiological Environmental Monitoring Program, Land Use Census, and the Non-Radiological Environmental Programs, which consist of Meteorological Monitoring, Land and Wetland Management, Water Treatment, Chemical Waste Management, and Waste Minimization and Recycling. This report also includes the Radiological Effluent Release Report for the reporting period of January 1 through December 31, 2002.

Radiological Environmental Monitoring Program The Radiological Environmental Monitoring Program (REMP) is established to monitor the ra-diological condition of the environment around Davis-Besse. The REMP is conducted in accor-dance with Regulatory Guide 4.8, Davis-Besse Technical'Specification 6.8.4.d and the Davis-Besse ODCM Section 6.0. This program includes-the sampling and analysis of environmental samples and evaluating the effects of releases of radioactivity on the environment.

Radiation levels and radioactivity have been monitored within a 25-mile radius around Davis-Besse since 1972. The REMP was established at Davis-Besse about five years before the Station became operational. This pre-operational sampling and analysis program provided data on ra-diation and radioactivity normally present in the area as natural background. Davis-Besse has continued to monitor the environment by sampling air, groundwater, milk, edible meat, fruit and vegetables, animal feed, soil, drinking water, surface water, fish, shoreline sediment, and by di-rect measurement of radiation.

Samples are collected from Indicator and Control locations. Indicator locations are within ap-proximately 5 miles of the site and are expected to show naturally-occurring radioactivity plus any increases of radioactivity that might occur due to the operation of Davis-Besse. Control lo-cations are farther-away from the Station and are expected to indicate the presence of only natu-rally-occurring radioactivity. The results obtained from the samples collected from indicator locations are compared with the results from those collected from control locations and with the concentrations present in the environment before Davis-Besse became operational. This allows for the assessment of any impact the operation of Davis-Besse might have had on the surround-ing environment.

Over 2000 radiological environmental samples were collected and analyzed in 2002. An expla-nation for the sample anomalies for this reporting period is provided on page 36.

The results of the REMP indicate that Davis-Besse continues to be operated safely in accordance with applicable federal regulations. No significant increase above background radiation or radio-activity is attributed to the operation of Davis-Besse.'

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report The sampling results are divided into four sections: atmospheric monitoring, terrestrial monitor-ing, aquatic monitoring and direct radiation monitoring:

• Air samples are collected continuously at ten locations. Four samplers are collected onsite. The other six are located offsite between one-half mile to twenty-two miles away. Particulate filters and iodine cartridges are collected weekly. The 2002 indicator results were in close agreement with the samples collected at control locations.

• Terrestrial monitoring includes analysis of milk, ground water, meat, fruits, vegetables, animal feed and soil samples. Samples are collected onsite and up to 25 miles away depending on the type of sample. Results of terrestrial sam-ple analyses indicate concentrations of radioactivity similar to previous years and indicate no build-up of radioactivity due to the operation of Davis-Besse.

• Aquatic monitoring includes the collection and analysis of drinking water, un-treated surface water, fish and shoreline sediments from onsite and the vicinity of Lake Erie. The 2002 results of analysis for fish, untreated surface water, drinking water and shoreline sediment indicate normal background concentra-tion of radionuclides and show no increase or build-up of radioactivity due to the operation of Davis-Besse.

• Direct radiation averaged 15.4 mrem/9ldays at indicator locations and 15.7 mrem/91 days at control locations. This is similar to results of previous years.

The operation of Davis-Besse in 2002 caused no significant increase in the concentrations of ra-dionuclides in the environment and no adverse effect on the quality of the environment. Radio-activity released in the Station's effluents was well below the applicable federal regulatory limits.

The estimated radiation dose to the general public due to the operation of Davis-Besse in 2002 was well below all applicable regulatory limits.

In order to estimate radiation dose to the public, the pathways through which public exposure can occur must be known. To identify these exposure pathways, an Annual Land Use Census is per-formed as part of the REMP. During the census, Station personnel travel every public road within a radius of five miles of Davis-Besse to locate radiological exposure pathways (e.g., resi-dences, vegetable gardens, milk cows/goats, etc.). The one pathway of particular interest is the pathway that, for a specific radionuclide, provides the greatest dose to a sector of the population.

This is called the critical pathway. The critical pathway for 2002 was a garden in the West sector 1610 meters from Davis-Besse.

Radiological Effluent Release Report The Radiological Effluent Release Report (RERR) is a detailed listing of radioactivity released from the Davis-Besse Nuclear Power Station during the period January 1, 2002 through Decem-ber 31, 2002. The doses due to radioactivity released during this period were estimated to be:

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Liquid Effluents:

Maximum Individual Whole Body Dose 1.00E-02 mrem (0.0100 mrem)

Maximum Individual Significant Organ Dose 2.17E-01 mrem (0.217 mrem)

Total Integrated Population Dose - 8.78E-01 person-rem (0.878 person-rem)

Average Dose to the Individual 4.02E-04 mrem (0.000402 mrem)

Gaseous Effluents:

Maximum Individual Whole Body Dose due to 5.70E-04 mrem I-13 1, H-3 and Particulates with half-lives (0.00057 mrem) greater than 8 days Maximum Significant Organ Dose due to I-131, 5.70E-04 mrem H-3 and Particulates with half-lives greater than (0.00057 mrem) 8 days Total Integrated Population Dose due to I-13 1, 1.58E-02 person-rem H-3 and Particulates with half-lives greater than (0.0158 person-rem) 8 days Average Dose to an individual in the population 7.25E-06 mrem due to 1-131, H-3 and Particulates with half-lives (0.00000725 mrem) greater than 8 days Maximum Individual Skin Dose due to noble gases 5.99E-05 mrad (0.0000599 mrad)

Maximum Individual Whole Body Dose due to 9.04E-06 mrad noble gases (0.00000904 mrad)

Total Integrated Population Dose due to noble gases 4.83E-03 person-rem (0.00483 person-rem)

Average Dose to individual in population due to 2.21E-06 mrem noble gases (0.00000221 mrem)

The Total Body doses to an individual and population in an unrestricted area due to direct ra-diation from Davis-Besse is not distinguishable from background. These doses represent an extremely small fraction of the limits set by the NRC or the limits set in the ODCM.

The abnormal gaseous releases during this reporting period are listed on page 89.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report There were no changes to the Process Control Program (PCP) during this reporting period.

There was one revision to the Offsite Dose Calculation Manual during 2002 (Revision 16.0).

Non-Radiological Environmental Programs Meteorological Monitoring The Meteorological Monitoring Program at Davis-Besse is part of a program for evaluating the radiological effects of the routine operation of Davis-Besse on the surrounding environment.

Meteorological monitoring began in October, 1968.

Meteorological data recorded at Davis-Besse include wind speed, wind direction, sigma theta (standard deviation of wind direction), ambient temperature, differential temperature, dew point and precipitation. Two instrument-equipped meteorological towers are used to collect data. Data recovery for the five instruments that are operationally required by Davis-Besse Technical Re-quirement Manual was 98.9 %.

Marsh Management The FirstEnergy Company owns the Navarre Marsh. It is leased to the U.S. Fish and Wildlife Service, who manage it as part of the Ottawa National Wildlife Refuge.

Special projects conducted in 2002 with the cooperation of Ohio Department of Natural Re-sources included a Volunteer Eagle Watcher Workshop. Davis-Besse hosted the eighth annual Federal Junior Duck Stamp Art Contest for the State of Ohio in cooperation with the Ottawa Na-tional Wildlife Refuge.

Davis-Besse's resident pair of American Bald Eagles returned to fledge three eaglets for the sec-ond time in two years. Nine healthy eaglets have been fledged from this location since 1995.

Water and Wastewater Treatment Davis-Besse withdraws water from Lake Erie and processes it through its Water Treatment Plant to produce high-purity water for use in the Station's cooling systems.

Since December 1, 1998, site domestic water has been provided by the Carroll Township Water Treatment Plant.

Sewage is treated at the Davis-Besse Wastewater Treatment Plant (WWTP) and pumped to a large basin. Following a retention period, the treated water is discharged with other station wastewater back to Lake Erie.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Chemical Waste Management The Chemical Waste Management Program at Davis-Besse was developed to ensure that the off-site disposal of non-radioactive hazardous and nonhazardous chemical wastes is performed in accordance with all applicable state and federal regulations. Chemical waste disposal vendors contracted by Davis-Besse use advanced technology for offsite disposal, including recycling of chemical wastes, in order to protect human health and the environment.

In 2002, the Davis-Besse Nuclear Power Station qualified as a small quantity generator status, generating 2,100 pounds of hazardous.waste. Other non-hazardous wastes generated include 18,500 gallons of used oil, 800 gallons of oil filters and solid oily debris, and 560 gallons of microfilm process chemicals, water treatment resins, sandblasting debris.

As required by Superfund Amendment and Reauthorization Act (SARA), Davis-Besse re-ported hazardous products and chemicals to local fire departments and local and state plan-ning commissions. As part of the program to remove PCB fluid from Davis-Besse, all electrical transformers have been retrofilled and reclassified as non-PCB transformers.

Waste Minimization and Recycling The Waste Minimization and Recycling Program at Davis-Besse began in 1991 with the collec-tion and recycling of paper. This program was expanded and reinforced during 1993 to include the recycling of paper, aluminum cans, cardboard, and metal. Paper and cardboard recycling typically exceeds 50 tons annually. The scrap metal collected onsite is sold to scrap companies.

Appendices Appendix A contains results from the Interlaboratory Comparison Program required by Davis-Besse Technical Specifications. Samples with known concentrations of radioisotopes are pre-pared by the Environmental Protection Agency (EPA), and then sent (with information on sample type and date of collection only) to the laboratory contracted by the Davis-Besse Nuclear Power Station to analyze its REMP samples. The Environmental Protection Agency (EPA) compares results to known standards.

Appendix B contains data reporting conversions used in the REMP at Davis-Besse. The appen-dix provides an explanation of the format and computational methods used in reporting REMP data. Information on counting uncertainties and the calculations of averages and standard devia-tions are also provided.

Appendix C lists the effluent concentration limits for alpha and beta-emitting radioisotopes and for certain other radioisotopes in air and water samples. These concentrations are taken directly from the Code of Federal Regulations, and provide comparison values for actual REMP sampling results for 2002.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Appendix D provides a REMP sampling summary from 2002. The appendix provides a listing of the following for each sample type:

• the number and types of analyses performed,

• the lower limit of detection for each analysis,

• the mean and range of results for control and indicator locations,

• the mean, range, and description of location with highest annual mean

• the number of non-routine results For detailed studies, Appendix D provides more specific information than that listed in Chapter 2 of this report. The information presented in Appendices A through D was provided by Environmental, Inc. Midwest Laboratory in their Final Progress Report to Toledo Edison (Febru-ary, 2003).

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Introduction Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Introduction Coal, oil, natural gas and hydropower are used to run this nation's electric generating stations; however, each method has its drawbacks. Coal-fired power can affect the environment through mining, acid rain and air pollution. Oil and natural gas are in limited supply and are, therefore, costly. Hydropower is limited due to the environmental impact of damming our waterways and the scarcity of suitable sites.

Nuclear power provides a readily available source of energy. The operation of nuclear power stations has a very small impact on the environment. In fact, the Davis-Besse Nuclear Power Station is surrounded by hundreds of acres of marshland, which make up part of the Ottawa National Wild-life Refuge. In order to provide better understanding of this unique source of energy, background information on basic radiation characteristics, risk assessment, reactor operation and effluent control is provided in this section.

Fundamentals The Atom All matter consists of atoms. Simply de-scribed, atoms are made up of positively and negatively charged particles, and particles which are neutral. These particles are called protons, electrons, and neutrons, respec- Iscu m o Ni`

tively (Figure 1). The relatively large pro-tons and neutrons are packed tightly to-gether in a cluster at the center of the atom called the nucleus. Orbiting around the nu-cleus are one or more smaller electrons. In an electrically neutral atom the negative charges of the electrons are balanced by the positive charges of the protons. Due to their \ Tr4EoRLTICAL 4-EL=rRN dissimilar charges, the protons and electrons' ORBIT have a strong attraction for each other. This \ . .

holds the atom together. - Other' attractive Figurt 1: An atom consists of two parts: a nucleus forces between the protons and neutrons containing positively charged protons and electrically keep the densely packed protons from repel- neutra neutrons and one or more negatively charged electrons orbiting the nucleus. Protons and neutrons ling each other, and prevent the nucleus are nearly identical in size and weight, while each is from breaking apart. about 2000 times heavier than an electron.

1

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Radiation and Radioactivity Isotopes and Radionuclides A group of identical atoms containing the same number of protons make up an element. In fact, the number of protons an atom contains determines its chemical identity. For instance, all atoms with one proton are hydrogen atoms, and all atoms with eight protons are oxygen atoms. How-ever, the number of neutrons in the nucleus of an element may vary. Atoms with the same num-ber of protons but different numbers of neutrons are called isotopes. Different isotopes of the same element have the same chemical properties, and many are stable or nonradioactive. An un-stable or radioactive isotope of an element is called a radioisotope, a radioactive atom, or a radionuclide. Radionuclides usually contain an excess amount of energy in the nucleus. The excess energy is usually due to a surplus or deficit in the number of neutrons in the nucleus. Ra-dionuclides such as Uranium-238, Berylium-7 and Potassium-40 occur naturally. Others are man-made, such as Iodine-131, Cesium-137, and Cobalt-60.

Radiation Radiation is simply the conveyance of energy through space. For instance, heat emanating from a stove is a form of radiation, as are light rays, microwaves, and radio waves. Ionizing radiation is another type of radiation and has similar properties to those of the examples listed above.

Ionizing radiation consists of both electromagnetic radiation and particulate radiation. Elec-tromagnetic radiation is energy with no measurable mass that travels with a wave-like motion through space. Included in this category are gamma rays and X-rays. Particulate radiation con-sists of tiny, fast moving particles which, if unhindered, travel in a straight line through space.

The three types of particulate radiation of concem to us are alpha particles, which are made up of 2 protons and 2 neutrons; beta particles, which are essentially free electrons; and neutrons.

The properties of these types of radiation will be described more fully in the Range and Shielding section.

Radioactive Decay Radioactive atoms, over time, will reach a stable, non-radioactive state through a process known as radioactive decay. Radioactive decay is the release of energy from an atom through the emis-sion of ionizing radiation. Radioactive atoms may decay directly to a stable state or may go through a series of decay stages, called a radioactive decay series, and produce several daugh-ter products that eventually result in a stable atom. The loss of energy and/or matter through radioactive decay may transform the atom into a chemically different element. For example, when Uranium-238 decays, it emits an alpha particle and, as a result, the atom loses 2 protons and 2 neutrons. As discussed previously, the number of protons in the nucleus of an atom deter-mines its chemical identity. Therefore, when the Uranium-238 atom loses the 2 protons and 2 neutrons, it is transformed into an atom of Thorium-234. Thorium-234 is one of the 14 succes-sive daughter products of Uranium-238. Radon is another daughter product, and the series ends with stable Lead-206.

2

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report This example is part of a known radioactive decay series, called the Uranium series, which be-gins with Uranium-238 and ends with Lead-206 (Figure 2).

234U1 v2. x105 v 4,

230Th I 8.x104v:

Beta Decay Alpha Decay 22 .  :

l 2Ra 1600 vrII 4r l =Rn l 3.82 d l 218 Po l 3.05 min 21 4 Po 26.8 min Figure 2: Principal Decay Scheme of the Uranium Series.

Half-life Most radionuclides vary greatly in the frequency with which their atoms release radiation. Some radioactive materials, in which there are only infrequent emissions, tend to have a very long half-lives. Those radioactive materials that are very active, emitting radiation more frequently, tend to have comparably shorter half-lives. The length of time an atom remains radioactive is defined in terms of half-lives. Half-life is the amount of time required for a radioactive substance to lose half of its activity through the process of radioactive decay. Half-lives vary from millionths of a second to millions of years.

Interaction with Matter Ionization Through interactions with atoms, alpha, beta, and gamma radiation lose their energy. When these forms of radiation interact with any form of material, the energy they impart may cause 3

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report atoms in that material to become ions, or charged particles. Normally, an atom has the same number of protons as electrons. Thus, the number of positive and negative charges cancel, and the atom is electrically neutral. When one or more electrons are removed an ion is formed. Ioni-zation is one of the processes that may result in damage to biological systems.

Range and Shielding Particulate and electromagnetic radiation each travel through matter differently because of their different properties. Alpha particles contain 2 protons and 2 neutrons, are relatively large, and carry an electrical charge of +2. Alpha particles are ejected from the nucleus of a radioactive atom at speeds ranging from 2,000 to 20,000 miles per second. However, due to its compara-tively large size, an alpha particle usually does not travel very far before it loses most of its en-ergy through collisions and interactions with other atoms. As a result, a sheet of paper or a few centimeters of air can easily stop alpha particles (Figure 3).

Beta particles are very small, and comparatively fast particles, traveling at speeds near the speed of light (186,000 miles per second). Beta particles have an electrical charge of either +1 or -1.

Because they are so small and have a low charge, they do not collide and interact as often as al-pha particles, so they can travel farther. Beta particles can usually travel through several meters of air, but may be stopped by a thin piece of metal or wood.

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-Neutron ...

AD I OACTIVE rlATERIAL PAPER ALuMINUl LEAD CONCRETE Figure 3: As radiation travels, it collides and interacts with other atons and loses energy. Alpha particles can be stopped by a sheet of paper. and bet particles by a thin sheet of aluminum. Gamma radiation is shielded by highly dense materials such as lead. while hydrogenous materials (those containing hydrogen atoms), such as water and cocrtC. ar used to stop neutrons.

Gamma rays are pure energy and travel at the speed of light. They have no measurable charge or mass, and generally travel much farther than alpha or beta particles before being absorbed. After repeated interactions, the gamma ray finally loses all of its energy and vanishes. The range of a gamma ray in air varies, depending on the ray's energy and interactions. Very high-energy gamma radiation can travel a considerable distance, whereas low energy gamma radiation may travel only a few feet in air. Lead is used as shielding material for gamma radiation because of its density. Several inches of Lead or concrete may be needed to effectively shield gamma rays.

4

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environnental Operating Report Neutrons come from several sources, including the interactions of cosmic radiation with the earth's atmosphere and nuclear reactions within operating nuclear power reactors. However, neutrons are not of environmental concern since the neutron source at nuclear power stations is sealed within the containment building.

Because neutrons have no charge, they are able to pass very close to the nuclei of the material through which they are traveling.. As a result, neutrons may be captured by one of these nuclei or they may be deflected. When deflected, the neutron loses some of its energy. After a series of these deflections, the neutron has lost most of its energy. At this point, the neutron moves about as slowly as the atoms of the material through which it is traveling, and is called a thermal neu-tron. In comparison, fast neutrons are much more energetic than thermal neutrons and have greater potential for causing damage to the material through which they travel. Fast neutrons can have from 200 thousand to 200 million times the energy of thermal neutrons.

Neutron shielding is designed to slow fast neutrons and absorb thermal neutrons. Neutron shielding materials commonly used to slow neutrons down are water or polyethylene. The shield is then completed with a material such as Cadmium, to absorb the now thermal neutrons. At Davis-Besse, concrete is used to form an effective neutron shield because it contains water mole-cules and can be e'asily molded around odd shapes.

Quantities and Units of Measurement There are several quantities and units of measurement used to describe radioactivity and its ef-fects. Three terms of particular usefulness are activity, absorbed dose, and dose equivalent.

Activity: Curie Activity is the number of atoms in a sample that disintegrate (decay) per unit of time. Each time an atom disintegrates, radiation is emitted. The curie (Ci) is the unit used to describe the activity of a material and indicates the rate at which the atoms of a radioactive substance are decaying.

One curie indicates the disintegration of 37 billion atoms per second.

A curie is a unit of activity, not a quantity of material. Thus, the amount of material required to produce one curie varies. For example, one gram (1/28th of an ounce) of radium-226 is the equivalent of one curie of activity, but it would take 9,170,000 grams (about 10 tons) of thorium-232 to equal one curie.

Smaller units of the curie are often used, especially when discussing the low concentrations of radioactivity detected in environmental samples. For instance, the microcurie (uCi) is equal to one millionth of a curie, while the picocurie (pCi) represents one trillionth of a curie.

5

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operadng Report Absorbed Dose: Rad Absorbed dose is a term used to describe the radiation energy absorbed by any material exposed to ionizing radiation, and can be used for both particulate and electromagnetic radiation. The Rad (radiation absorbed dose) is the unit used to measure the absorbed dose. It is defined as the energy of ionizing radiation deposited per gram of absorbing material (1 Rad = 100 erg/gm).

The rate of absorbed dose is usually given in Rad/hr.

If the biological effect of radiation is directly proportional to the energy deposited by radiation in an organism, the Rad would be a suitable measurement of the biological effect. However, bio-logical effects depend not only on the total energy deposited per gram of tissue, but on how this energy is distributed along its path. Experiments have shown that certain types of radiation are more damaging per unit path of travel than are others. Thus, another unit is needed to quantify the biological damage caused by ionizing radiation.

Dose Equivalent: Rem Biological damage due to alpha, beta, gamma and neutron radiation may result from the ioniza-tion caused by this radiation. Some types of radiation, especially alpha particles which cause dense local ionization, can result in up to 20 times the amount of biological damage for the same energy imparted as do gamma or X-rays. Therefore, a quality factor must be applied to account for the different ionizing capabilities of various types of ionizing radiation. When the quality factor is multiplied by the absorbed dose, the result is the dose equivalent, which is an estimate of the possible biological damage resulting from exposure to a particular type of ionizing radia-tion. The dose equivalent is measured in rem (radiation equivalent man).

An example of this conversion from absorbed dose to dose equivalent uses the quality factor for alpha radiation, which is equal to 20. Thus, 1 Rad of alpha radiation is approximately equal to 20 rem. Beta and gamma radiation each have a quality factor of 1, therefore one Rad of either beta or gamma radiation is approximately equal to one rem. Neutrons have a quality factor ranging from 2 to 10. One rem produces the same amount of biological damage, regardless of the source. In terms of radiation, the rem is a relatively large unit. Therefore, a smaller unit, the millirem, is often used. One millirem (mrem) is equal to 11000 of a rem.

Deep Dose Equivalent (DDE)

Deep dose equivalent is the measurement of dose within the body, from sources of radiation that are external to the body. It is what is measured and recorded on thermoluminescent dosimeters (TLDs), film badges or other dosimeters. For example, at Davis-Besse or at any hospital that has x-ray equipment, you will see people wearing these devices. These instruments are worn to measure DDE.

Committed Effective Dose Equivalent (CEDE)

Committed effective dose equivalent is a measure of the dose received from any radioactive ma-terial taken into the body. It is calculated from the sum of the products of the committed dose 6

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report equivalent to the organ or tissue multiplied by the organ or tissue-weighting factor. CEDE ac-counts for all the dose delivered during the entire time the radioactive material is in the body.

Total Effective Dose Equivalent (TEDE)

Total effective dose equivalent is the sum of the deep dose equivalent (for dose from sources ex-ternal to the body) and the connitted effective dose equivalent (for internal dose). Since they are both doses to the body, they are not tracked separately. The NRC limits occupational dose to a radiation worker to five rem (5000 mrem) TEDE per year.

Sources of Radiation Background Radiation Radiation did not begin with the nuclear power industry, and occurs naturally on earth. It is probably the most "natural" thing in nature. Mankind has always lived with radiation and proba-bly always will. In fact, during every second of life, over 7,000 atoms undergo radioactive decay "naturally" in the body of the average adult. In addition, radioactive decay occurs naturally in soil, water, air and space. All these common sources of radiation contribute to the natural back-ground radiation to which we are all exposed.

The earth is being showered by a steady stream of high-energy gamma rays and particulate radia-tion that come fron space known as cosmic radiation. The atmosphere shields us from most of this radiation, but everyone still receives about 20 to 50 mrem each year from this source. The thinner air at higher altitudes provides less protection against cosrnic radiation. People living at higher altitudes or flying in an airplane are exposed to even higher levels cosmic radiation. Ra-dionuclides commonly found in the atmosphere as a result of cosmic ray interactions include Be-ryllium-7, Carbon-14, tritium (H-3), and Sodium-22.

Another common naturally occurring radionuclide is Potassium-40. About one-third of the ex-ternal and internal dose from naturally occurring background radiation is attributed to this radio-active isotope of potassium.

The major source of background radiation is radon, a colorless, odorless, radioactive gas that re-sults from the decay of Radium-226, a member of the Uranium-238 decay series. Since Uranium occurs naturally in all soils and rocks, everyone is continuously exposed to Radon and its daugh-ter products. Radon is not considered to pose a health hazard unless it is concentrated in a con-fined area, such as buildings, basements or underground mines. Radon-related health concerns stem from the exposure of the lungs to this radioactive gas. Radon emits alpha radiation when it decays, which can cause damage to internal tissues when inhaled. As a result, exposure to the lungs is a concern, since the only recognized health effect associated with exposure to Radon is an increased risk of lung cancer. This effect has been seen when Radon is present at levels common in uranium mines. According to the National Council on Radiation Protection and Measurement (NCRP), more than half of the radiation dose the average American receives is at-tributed to Radon.

7

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report SOURCES OF EXPOSURE TO THE PUBLIC Terrestrial 8%

-j Internal 11%

I Radon 55%

Manmade 18% (X-Rays 10%, Nuclear Medicine 4%, Consumer Products 3%, Nuclear Power

<0.2%)

Figure 4: The most significant annual dose received by an individual of the public is that received from naturally occurring radon. A very small annual dose to the public results from producing electricity by nuclear power.

Further information on Radon, its measurement, and actions to reduce the Radon concentration in buildings can be obtained by contacting the state Radon program office at the following ad-dress:

Ohio Department of Health, Bureau of Radiation Protection P.O. Box 118, 35 East Chestnut Building 7b Floor Columbus, Ohio 43216-0118 614) 481-5800 (800) 523-4439 (in Ohio Only)

The approximate average background radiation in this area (see Figure 4) is 300 mremlyear.

8

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Man-made Radiation In addition to naturally occurring cosmic radiation and radiation' from naturally occurring radio-activity, people are also exposed to man-made'radiation. The largest sources of exposure include medical x-rays and radioactive pharmaceuticals. Small doses are also received from consumer products such as televisions, smoke detectors, and fertilizers. Fallout from nuclear weapons tests is another source of man-made exposure.' Fallout radionuclides include Strontium-90, Cesium-137, and tritium. Less than one percent-of the annual dose a member of the public re-ceives is a result of having electricity generated by nuclear power.

Health Effects of Radiation The effects of ionizing radiation on human health have been under study for more than ninety years. Scientists have obtained valuable knowledge through the study of laboratory animals that were exposed to radiation under extremely controlled conditions. However, it has been difficult to relate the biological effects of irradiated laboratory animals to the potential health effects on humans.

The effects of radiation on humans can be divided into two categories, somatic and genetic. So-matic effects are those which develop in the directly exposed individual, including an unborn child. Genetic effects are those which are observed in the offspring of the exposed individual.

Somatic effects can be divided further into acute and chronic effects. Acute effects develop shortly after exposure to large amount of radiation. Much study has been done with human populations that were exposed to ionizing radiation under various circumstances. These groups include the survivors of the atomic bomb, persons undergoing medical radiation treatment, and early radiologists, who accumulated large doses of radiation, unaware of the potential hazards.

Chronic effects are a result of exposure to radiation over an extended period of time. Examples of such groups are clock dial painters, who ingested large amounts of Radium by "tipping" the paint brushes with their lips, and Uranium miners, who inhaled large amounts of radioactive dust while mining pitchblende (Uranium ore). The studies performed on these groups have increased our knowledge of the health effects from comparatively very large doses of radiation received over long periods of time.

Continuous exposure to low levels of radiation may produce somatic changes over an extended period of time. For example, someone may develop cancer from man-made radiation, back-ground radiation, or some other source not related to radiation. Because all illnesses caused by low level radiation can also be caused by other factors, it is virtually impossible to determine in-dividual health effects of low level radiation. Even though no effects have been observed at doses less than 50 rem, to be conservative, we assume the health effects resulting from low doses of radiation occur proportionally to those observed following large doses of radiation. Most ra-diation scientists agree that this assumption over-estimates the risks associated with a low-level radiation exposure. The effects predicted in this manner have never been actually observed in any individuals exposed to low level radiation. Therefore, the most likely somatic effect of low level radiation is believed to be a small increased risk of cancer. Genetic effects could occur as a result of ionizing radiation interacting with the genes in the human cells. Radiation (as well as 9

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report common chemicals) can cause physical changes or mutations in the genes. Chromosome fibers can break and rearrange, causing interference with the normal cell division of the chromosome by affecting their number and structure. A cell is able to rejoin the ends of a broken chromosome, but if there are two breaks close enough together in space and time, the broken ends from one break could join incorrectly with those from another. This could cause translocations, inversions, rings, and other types of structural rearrangements. When this happens, new mutated genes are created. Radiation is not the only mechanism by which such changes can occur. Spontaneous mutations and chemically induced mutations also have been observed. These mutated genes may be passed from parent to offspring. Viable mutations due to low level, low dose radiation have not been observed in humans.

Health Risks While people may accept the risks inherent in their personal-activities, such as smoking and driving to work each day, they are less inclined to accept the risk inherent in producing electric-ity. As with any industrial environment, it is not possible to guarantee a risk free environment.

Thus, attention should be focused on taking steps to safeguard the public, on developing a realis-tic assessment of the risks, and on placing these risks in perspective. The perceptions of risk as-sociated with exposure to radiation may have the greatest misunderstanding. Because people may not understand ionizing radiation and its associated risks, they may fear it. This fear is com-pounded by the fact that we cannot hear, smell, taste or feel ionizing radiation.

We do not fear other potentially hazardous things for which we have the same lack of sensory perception, such as radio waves, carbon monoxide, and small concentrations of numerous cancer-causing substances. These risks are larger and measurable compared to those presumed to be as-sociated with exposure to low level, low dose radiation. Most of these risks are with us through-out our lives, and can be added up over a lifetime to obtain a total effect. Table 1 shows a number of different factors that decrease the average life expectancy of individuals in the United States.

Table 1: Risk Factors: Estimated Decrease in Average Life Expectancy Overweight by 30%: 3.6 years Cigarette smoking: 1 pack/day 7.0 years 2 packs/day 10.0 years Heart Disease: 5.8 years Cancer: 2.7 years City Living (not rural): 5.0 years All operating commercial nuclear power plants totaled: less than 12 minutes 10

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Benefits of Nuclear Power Nuclear power plays an important part in meeting today's electricity needs, and will continue to serve as an important source of electric energy well into the future. Today more than twenty per-cent of the electricity produced in the United States is from nuclear powered electrical generating stations.

Nuclear power offers several advantages over altemative sources of electric energy:

• nuclear power has an excellent safety record dating back to 1957, when the first commercial nuclear power station began operating,

• Uranium, the fuel for nuclear power stations, is a relatively inexpensive fuel that is readily available in the United States,

• Nuclear power is the cleanest energy source for power stations that use steam to produce electricity. There are no greenhouse gases or acid gases produced when using nuclearfuel.

The following sections provide information on the fundamentals of how Davis-Besse uses nu-clear fuel and the fission process to produce electricity.

Nuclear Power Production Electricity is produced in a nuclear power station in the same way as in a fossil-fueled station with the exception of the source of heat. Heat changes water to steam that turns a turbine. In a fossil-fueled station, the'fuel is burned in a furnace, which is also a boiler. Inside the boiler, wa-ter is turned into steam. In a nuclear station, a reactor that contains a core of nuclear fuel,' pri-marily uranium, replaces the fumace. Heat is produced when the atoms of Uranium are split, or fissioned, inside the reactor.

What is Fission?

A special force called the binding force holds the protons and neutrons together in the nucleus of the atom. The strength of this binding force varies from atom to. atom. If the bond is weak enough, the nucleus can be split when bombarded by a free neutron (Figure 5). This causes the entire atom to split, producing smaller atoms, more free neutrons, and heat. In a nuclear reactor, a chain reaction of fission events provides the heat necessary to boil the water to produce steam.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environrnental Operating Report 0 O S Bombiirdta gw Neutron3b&rd Figdo O n Fragment Figure 5: When a heavy atom. such as uranium-235 is split or fissioned, heat. free neutrons, and fission fragments result. The free neutrons can then strike neighboring atoms causing them to fission also. In the proper environment.

this process can continue indefinitely in a chain reacdon.

Nuclear Fuel The fissioning of one Uranium atom releases approximately 50 million times more energy than the combustion of a single Carbon atom common to all fossil fuels. Since a single small reactor fuel pellet contains trillions of atoms, each pellet can release an extremely large amount of en-ergy. The amount of electricity that can be generated from three small fuel pellets would require about 3.5 tons of coal or 12 barrels of oil to generate.

Nuclear fission occurs spontaneously in nature, but these natural occurrences cannot sustain themselves because the freed neutrons either are absorbed by non-fissionable atoms or quickly decay. In contrast, a nuclear reactor minimizes neutron losses, thus sustaining the fission proc-ess by several means:

• using fuel that is free of impurities that might absorb the free neutrons,

• enriching the concentration of the rarer fissionable isotope of Uranium (U-235) relative to the concentration of U-238, a more common isotope that does not fis-sion easily,

• slowing down neutron by providing a "moderator" such as water to increase the probability of fission.

Natural Uranium contains less than one percent U-235 compared to the more abundant U-238 when it's mined. Before it can be economically used in a reactor, it is enriched to three to five percent U-235, in contrast to nuclear material used in nuclear weapons which is enriched to over 97 percent. Because of the low levels of U-235 in nuclear fuel, a nuclear power station cannot explode like a bomb.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report After the Uranium ore is separated from the earth and rock, it is concentrated in a milling proc-ess. After milling the ore to a granular form and dissolving out the Uranium with acid, the Ura-nium is converted to Uranium hexafluoride (UF6 ). -UF 6 is a chemical form of Uranium that exists as a gas at temperatures slightly above room temperature. The UF 6 is then highly purified and shipped to an enrichment facility where gaseous diffusion converters increase the concen-tration of U-235. The enriched gaseous UF6 is then converted into powdered Uranium dioxide (UO2 ), a highly stable ceramic material. The U0 2 powder is put under high pressure to form fuel pellets, each about 5/8 inch long and 3/8 inch in diameter. Approximately five pounds of these pellets are placed into a 12-foot long metal tube made of Zirconium alloy. The tubes constitute the fuel cladding. The fuel cladding is highly resistant to heat, radiation, and corrosion. When the tubes are filled with fuel pellets, they are called fuel rods.

The Reactor Core Two hundred eight fuel rods comprise a single fuel assembly. The Reactor core at Davis-Besse contains 177 of these fuel assemblies, each approximately 14 feet tall and 2,000 pounds in weight. In addition to the fuel rods, the fuel assembly also contains 16 vacant holes for the in-sertion of control rods, and one vacant hole for an incore-monitoring probe. This probe monitors temperature and neutron levels in the fuel assembly. The Davis-Besse reactor vessel, which contains all the fuel assemblies, weighs 838,000 pounds, has a diameter of 14 feet, is 39 feet high, and has steel walls that are 8 1/2 inches thick.

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p.. _ REACVT WESSEL Figure 6: The reactor core at Davis-Besse contains 177 fuel assemblies. Each assembly contains 208 fuel rods.

Each fuel rod is filled with approximately five pounds of fuel pellets, each pellet is approximately 3/8 inch in diameter and 5/8 inch long.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Envirorunental Operating Report Fission Control Raising or lowering control rod assemblies into the reactor core controls the fission rate. Each assembly consist of "fingers" containing Silver, Indium, and Cadmium metals that absorb free neutrons, thus disrupting the fission chain reaction. When control rod assemblies are slowly withdrawn from the core, fissioning begins and heat is produced. If the control rod assemblies are inserted rapidly into the reactor core, as during a plant "trip", the chain reaction ceases. A slower acting (but more evenly distributed) method of fission control is achieved by the addition of a neutron poison to the reactor coolant water. At Davis-Besse, high-purity boric acid is con-centrated or diluted in the coolant to achieve the desired level of fission. Boron-10 readily ab-sorbs free neutrons, forming Boron- l , removing the absorbed neutrons from the chain reaction.

Reactor Types Virtually all of the commercial reactors in this country are either boiling water reactors (BWRs) or pressurized water reactors (PWRs). Both types are also called light water reac-tors (LWRs) because their coolant, or medium to transfer heat, is ordinary water, which contains the light isotope of Hydrogen. Some reactors use the heavy isotope of Hydrogen (deuterium) in the reactor coolant. Such reactors are called heavy water reactors (HWRs).

In BWRs, water passes through the core and boils into steam. The steam passes through separa-tors which remove water droplets. The steam then travels to dryers before entering the turbine.

After passing though the turbine the steam is condensed back into water and returns to the core to repeat the cycle.

In PWRs, the reactor water or coolant is pressurized to prevent it from boiling. The reactor water is then pumped to a steam generator (heat exchanger) where its heat is transferred to a secon-dary water supply. The secondary water inside the generator boils into steam, which is then used to tum the turbine. This steam is then condensed back into water and returned to the steam gen-erator. Davis-Besse uses a PWR design.

The following paragraphs describe the various systems illustrated in Figure 7. Major systems in the Davis-Besse Station are assigned a different color in the figure.

14

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Station Systems Containment Building and Fission Product Release Barriers The Containment building houses the reactor vessel, the pressurizer, two steam generators, the Reactor Coolant Pumps and Reactor Coolant System piping. The building is constructed of an inner 1 -1/2 inch thick steel liner or Containment vessel, and the Shield Building with steel-reinforced concrete walls 2 feet thick. The shield building protects the containment vessel from a variety of environmental factors and provides an area for a negative pressure boundary around the steel Containment vessel. In the event that the integrity of the Containment vessel is com-promised (e.g., a crack develops), this negative pressure boundary ensures that any airborne ra-dioactive contamination present in the containment vessel is prevented from leaking out into the environment. This is accomplished by maintaining the pressure inside the Shield Building lower than that outdoors, thus forcing clean outside air to leak in, while making it impossible for the contaminated air between the Containment vessel and the Shield Building to leak out. The Con-tainment vessel is the third in a series of barriers that prevent the release of fission products in the unlikely event of an accident. The first barrier to the release of fission products is the fuel cladding itself. The second barrier is the walls of the primary system, i.e. the reactor vessel, steam generator and associated piping.

The Steam Generators The steam generators perform the same function as a boiler at a fossil-fueled power station.

The steam generator uses the heat of the primary coolant inside the steam generator tubes to boil the secondary side feedwater (secondary coolant). Fission heat from the reactor core is trans-ferred to the steam generator in order to provide the steam necessary to drive the turbine. How-ever, heat must also be removed from the core even after reactor shutdown in order to prevent damage to the fuel cladding. Therefore, pumps maintain a continuous flow of coolant through the reactor and steam generator. Primary loop water (green in Figure 7) exits the reactor at ap-proximately 606°F, passes through the steam generator, transferring some of its heat energy to the Secondary loop water (blue in Figure 7) without actually coming in contact with it. Primary coolant water exits the steam generator at approximately 558°F to be circulated back into the re-actor where it is again heated to 606°F as it passes up through the fuel assemblies. Under ordi-nary conditions, water inside the primary system would boil long before it reached such temperatures. However, it is kept under a pressure of approximately 2,200 pounds-per-square-inch (psi) at all times. This prevents the water from boiling and is the reason the reactor at Davis-Besse is called a Pressurized Water Reactor. Secondary loop water enters the base of the steam generator at approximately 450°F and under 1,100 psi pressure. At this pressure, the water can easily boil into steam as it passes over the tubes containing the primary coolant water.

Both the primary and the secondary coolant water are considered closed oop systems. This means that they are designed not to come in physical contact with one another. Rather, the cooling water in each loop transfers heat energy by convection. Convection is a method of heat transfer that can occur between two fluid media. It is the same process by which radiators are used to heat homes. The water circulating inside the radiator is separated from the air (a "fluid" medium) by the metal piping.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report The Turbine Generator The turbine, main generator, and the condenser are' all housed in what is commonly referred to as the Turbine Building. The purpose of the turbine is to convert' the thermal energy of the steam produced in the steam generator (referred to as main steam, red in Figure 7) to rotational energy of the turbine generator shaft. The turbine at Davis-Besse is actually composed of one six-stage high-pressure turbine and two seven-stage low-pressure turbines aligned on a common shaft. A turbine stage refers to a set of blades. Steam enters at the center of each turbine and moves outward along the shaft in opposite directions through each successive stage'of blading.

As the steam passes over the turbine blades, it loses pressure. Thus, the blades must be propor-tionally larger in successive stages to extract enough energy from the steam to rotate the shaft at the correct speed.

The purpose of the main generator is to convert the rotational energy of the shaft to electrical energy for commercial usage and support of station systems. The main generator is composed of two parts, a stationary stator that contains coils of copper conductors, and a rotor that supplies a rotating magnetic field within the coils of the stator. Electrical current is generated in the stator portion of the main generator. From this point, the electric current passes through a series of transformers for transmission and use throughout northern Ohio.

The Condenser After the spent steam in the secondary loop (blue in Figure 7) passes through the High and Low Pressure Turbines, it is collected in a cavernous condenser several stories tall and containing more than 70,000 small tubes. Circulating Water (yellow in Figurc 7) goes to the Cooling Tower after passing through the tubes inside the Condenser. 'As the steam from the Low-Pressure Turbines passes over these tubes, it is cooled and condensed. The condensed water is then purified and reheated before being circulated back into the steam generator again in a closed loop system. Circulating water forns 'the third (or tertiary) and final loop of cooling water used at the Davis-Besse Station.

Similar to the primary to secondary interface, the secondary-to-tertiary interface is based on a closed-loop design. The Circulating Water, which is pumped through the tubes in the Water Box, is able to cool the water in the Condenser'by the processes of conduction'and convection.

Even in the event of a primary-to-secondary leak, the water vapor exiting the Davis-Besse Cool-ing Tower would remain non-radioactive. Closed loops are an integral part of the design of any nuclear facility. This feature greatly reduces the chance of environmental impact from Station operation.

The Cooling Tower The Cooling Tower at Davis-Besse is easily the most noticeable feature of the plant. The tower stands 493 feet high and the diameter of the base is 411 feet. Two nine-foot diameter pipes cir-culate 480,000 gallons of water per minute to the tower. Its purpose is to recycle water from the Condenser by cooling and retuming it.

17

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report After passing through the Condenser, the Circulating Water has warmed to approximately 100°F.

In order to cool the water back down to 70°F, the Circulating Water enters the Cooling Tower forty feet above the ground. It is then sprayed evenly over a series of baffles called fillsheets, which are suspended vertically in the base of the tower. A natural draft of air is swept upward through these baffles and cools the water by evaporation. The evaporated water exits the top of the Cooling Tower as water vapor.

As much as 10,000 gallons of water per minute are lost to the atmosphere via the Cooling Tower.

Even so, approximately 98 percent of the water drawn from Lake Erie for station operation can be recycled through the Cooling Tower for reuse. A small portion of the Circulating Water is discharged back to Lake Erie at essentially the same temperature it was withdrawn earlier. The slightly warmer water has no adverse environmental impact on the area of lake surrounding the discharge point.

Miscellaneous Station Safety Systems The orange system in Figure 7 is part of the Emergency Core Cooling System (ECCS) housed in the Auxiliary Building of the station. The ECCS consists of three overlapping means of keeping the reactor core covered with water, in the unlikely event of a Loss-of-Coolant Accident (LOCA), thereby protecting the fuel cladding barrier against high-temperature failure. Depend-ing on the severity of the loss of pressure inside the Primary System, the ECCS will automati-cally channel borated water into the Reactor by using High Pressure Injection Pumps, a Core Flood Tank, or Low Pressure Injection Pumps. Borated water can also be sprayed from the ceiling of the Containment Vessel to cool and condense any steam that escapes the Primary Sys-tem.

The violet system illustrated in Figure 7 is responsible for maintaining the Primary Coolant water in a liquid state. It accomplishes this by adjusting the pressure inside the Primary System. Heat-ers inside the Pressurizer turn water into steam. This steam takes up more space inside the Pres-surizer, thereby increasing the overall pressure inside the Primary System. The Pressurizer is equipped with spray heads that shower cool water over the steam in the unit. In this case, the steam condenses and the overall pressure inside the Primary System drops. The Quench Tank pictured in Figure 8 is simply where excess steam is directed and condensed for storage.

The scarlet system in Figure 7 is part of the Auxiliary Feedwater System, a key safety system in event the main feedwater supply (blue in Figure 7) to the Steam Generator is lost. Following a reactor shutdown, the Auxiliary Feedwater System can supply water to the Steam Generators from the Condensate Storage Tanks. The Auxiliary Feedwater System is housed in the Turbine Building along with the Turbine, Main Generator, and the Condenser.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Reactor Safety and Summary Nuclear power plants are inherently safe,-not only by the laws of physics, but by design. Nuclear power plants cannot explode like a bomb, because the concentration of fissionable material is far less than is necessary for such a nuclear explosion. Also, many safety features are equipped with several backup systems to ensure that any possible accident would be prevented from causing a serious health or safety threat to the public, or serious impact on the local environment. Davis-Besse, like all U.S. nuclear units, has many overlapping, or redundant safety features. If one system should fail, there are still back-up systems to assure the safe operation of the Station.

During normal operation, the Reactor Control System regulates the power output by adjusting the position of the control rods. The Reactor can be automatically shut down by a separate Reac-tor Protection System, which causes all the control rod assemblies to be quickly and completely inserted into the Reactor core, stopping the chain reaction. To guard against the possibility of a Loss of Coolant Accident, the Emergency Core Cooling System is designed to pump reserve water into the reactor automatically if the reactor coolant pressure drops below a predetermined level.

The Davis-Besse Nuclear Power Station was designed, constructed, and operates to produce a reliable, safe, and environmentally sound source of electricity.

Radioactive Waste Many of the activities we depend on in our everyday lives produce radioactive waste by-products.

Nuclear energy, industrial processes, and medical treatments are some of these activities. These by-products are managed and disposed of under strict requirements set by the federal govern-ment. With the exception of used nuclear fuel assemblies, these by-products produced at com-mercial power plants are referred to as low level radioactive waste.

Low Level Radioactive Waste Low level radioactive waste consists mainly of ordinary trash and other items that have become contaminated with radioactive materials. It includes plastic gloves and other protective clothing, machine parts and tools, medical and laboratory equipment, filters, resins, and general scrap.

The radioactive material in low level radioactive waste emits the same types of radiation that naturally occurring radioactive materials tend to emit. Most low level radioactive waste "decays" to background levels of radioactivity in months or years. Nearly all of it diminishes to stable materials in less than 300 years.

Davis-Besse currently ships low-level radioactive waste to disposal facilities in South Carolina and Utah. Davis-Besse has the capacity to store low-level waste produced on site for several years in the Low Level Radioactive Waste Storage Facility (LLRWSF), should these facilities close.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report High Level Nuclear Waste Like any industrial or scientific process, nuclear energy does produce waste. The most radioac-tive is defined as "high-level" waste (because it has high levels of radioactivity). Ninety-nine percent of high-level waste from nuclear plants is used nuclear fuel. The fuel undergoes certain changes during fission. Most of the fragments of fission, pieces that are left over after the atom is split, are radioactive. After a period of time, the fission fragments trapped in the fuel assem-blies reduce the efficiency of the chain reaction. Every 18 to 24 months, the oldest fuel assem-blies are removed from the reactor and replaced with fresh fuel.

High-level nuclear waste volumes are small. Davis-Besse produces about 30 tons of used fuel every 24 months. All the used fuel produced by all America's nuclear energy plants since the first plant started operating over 30 years ago would cover an area the size of a football field about five yards deep. All of America's nuclear plants combined produce only 3,000 tons of used fuel each year. By contrast, the U.S. produces about 300,000,000 tons of chemical waste annu-ally. Also, nuclear waste slowly loses its radioactivity, but some chemical waste remains hazard-ous indefinitely.

Davis-Besse presently stores most of its used fuel in a steel-lined water-filled concrete vault in-side the plant. The Department of Energy is charged with constructing a permanent high-level waste repository for all of the nation's nuclear plants. By law, the Department of Energy was required to accept fuel from utilities by the end of 1998. Currently, Yucca Mountain, Nevada, is being considered as a possible site. Until the permanent DOE site is developed, nuclear plants will be responsible for the continued safe storage of high-level waste. At Davis-Besse, the fuel pool reached its capacity in 1996. At the end of 1996, Davis-Besse began the process of moving the older fuel assemblies that no longer require water cooling to air-cooled concrete shielded canisters. These will remain onsite until the Department of Energy facilities are ready to receive them. Dry fuel storage is already used in many countries, including Canada, and in the U.S. at nuclear plants in Arkansas, Colorado, Maryland, Michigan, Minnesota, Virginia, Wisconsin and South Carolina. Figure 8 illustrates the Dry Fuel Storage module arrangement at Davis-Besse.

In 2001, work began to increase the storage capacity of the Spent Fuel Pool. The pool remains the same size, however, removing old storage racks and replacing them with new ones changed the configuration of storage, and allows the site to safely hold all the fuel used during its 40 year expected life. This modification was completed in April of 2002.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Description of the Davis-Besse Site The Davis-Besse site is located in Carroll Township of Ottawa County, Ohio. It is on the south-western shore of Lake Erie, just north of the Toussaint River. The site lies north and east of Ohio State Route 2, approximately 10 miles northwest of Port Clinton, 7 miles north of Oak Harbor, and 25 miles east of Toledo, Ohio (Figure 9).

This section of Ohio is flat and marshy, with maximum elevations of only a few feet above the level of Lake Erie. The area originally consisted of swamp forest and marshland, rich in wildlife but unsuitable for settlement and farming. During the nineteenth century, the land was cleared and drained, and has been farmed successfully since. Today, the terrain consists of farmland with marshes extending in some places for up to two miles inland from the Sandusky Lake Shore Ridge.

Figure 9: Davis-Besse is near Oak Harbor, Port Clinton, and the Ottawa National Wildlife Refuge.

The Davis-Besse site is mainly comprised of marshland, with a small portion consisting of farm-land. The marshes are part of a valuable ecological resource, providing a breeding ground for a variety of wildlife, and a refuge for migratory birds. The site includes a tract known as Navarre Marsh, which was acquired from the U.S. Bureau of Sport Fisheries and Wildlife, Department of the Interior. In 1971, Toledo Edison purchased the 188-acre Toussaint River Marsh. The Tous-saint River Marsh is contiguous with the 610-acre Navarre Marsh section of the Ottawa National Wildlife Refuge.

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Davis-Besse Nuclear Power Station 2002 .Annual Radiological Environmental Operating Report The immediate area near Davis-Besse is sparsely populated. Ottawa County had a population of 40,985 according to the 2000 Census. The incorporated communities nearest to Davis-Besse are:

• Port Clinton - 10 miles southeast, population 6,391

• Oak Harbor- 7 miles south, population 2,841

• Rocky Ridge - 7 miles west southwest, population 389

• Toledo (nearest major city) - 25 miles west, population 313,619 There are some residences along the lakeshore used mainly as summer homes. However, -the major resort area of the county is farther east, around Port Clinton, Lakeside, and the Bass Is-lands.

The majority of non-marsh areas around the Davis-Besse site are used for farming. The major crops include soybeans, corn, wheat, oats, hay, fruits and vegetables. Meat and dairy animals are not major sources of income in the area. The main industries within five miles of the site are lo-cated in Erie Industrial Park, about four miles southeast of the station.

Most of the remaining marshes in the area have been maintained by private hunting clubs, the U.S. Fish and Wildlife Service, and the Ohio Department of Natural Resources, Division of Wildlife. The State of Ohio Department of Natural Resources operates many wildlife and recrea-tional areas within 10 miles of the Station. These include Magee Marsh, Turtle Creek, Crane Creek State Park, and the Ottawa National Wildlife Refuge. Magee Marsh and Turtle Creek lie between three and six miles WNW of the Station. Magee Marsh is a wildlife preserve that al-lows public fishing, nature study, and a controlled hunting season. Turtle Creek, a wooded area at the southem end of Magee Marsh, offers boating and fishing. Crane Creek State Park is adja-cent to Magee Marsh, and is a popular picnicking,' swimming, and fishing area. The Ottawa Na-tional Wildlife Refuge lies four to nine miles WNW of the Site, immediately west of Magee Marsh.

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report References

1. "Basic Radiation Protection Criteria," Report No. 39, National Council on Radiation Protec-tion and Measurement, Washington, D.C. (January 1971).

2. "Cesium-137 from the Environment to Man: Metabolism and Dose," Report No. 52, National Council on Radiation Protection and Measurements, Washington, D.C. (January 1977).

3. Deutch, R., "Nuclear Power, A Rational Approach," Fourth edition, GP Courseware, Inc.,

Columbia, MD. (1987).

4. Eisenbud, M., "Environmental Radioactivity," Academic Press, Inc., Orlando, FL. (1987).

5. "Environmental Radiation Measurements," Report No. 50, National Council on Radiation Protection and Measurements, Washington, D.C. (December 1976).

6. "Exposure of the Population in the United States and Canada from Natural Background Ra-diation," Report No. 94, National Council on Radiation Protection and Measurements, Washington, D.C. (December 1987).

7. "Health Effects of Exposure to Low Levels of Ionizing Radiation: BEIR V," Comnittee on the Biological Effects of Ionizing Radiations, Board on Radiation Effects Research Commis-sion on Life Sciences, National Research Council, National Academy Press, Washington, D.C. (1990).

8. Hendee, William R., and Doege, Theodore C., "Origin and Health Risks of Indoor Radon,"

Seminars in Nuclear Medicine, Vol. XVIII, No. 1, American Medical Association, Chicago, IL. (January 1987).

9. Hurley, P., "Living with Nuclear Radiation," University of Michigan Press, Ann Arbor, MI.

(1982).

10. "Indoor Air Quality Environmental Information Handbook: Radon," prepared for the United States Department of Energy, Assistant Secretary for Environment, Safety and Health, by Mueller Associated, Inc., Baltimore, MD. (January 1986).

11. Introduction to Davis-Besse Nuclear Power Station Plant Technology, July 1992, Rev. 4, Pg.2-9.

12. "Ionizing Radiation Exposure of the Population of the United States," Report No. 93, Na-tional Council on Radiation Protection and Measurements, Washington, D.C. (September 1987).

13. "Natural Background Radiation in the United States," Report No. 45, National Council on Radiation Protection and Measurements, Washington, D.C. (November 1975).

24

!I

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report

14. "Nuclear Energy Emerges from 1980's Poised for New Growth," U.S. Council for Energy Awareness, Washington, D.C. (1989).

15. "Nuclear Power: Answers to Your Questions," Edison Electric Institute, Washington, D.C.

(1987).

16. "Public Radiation Exposure from Nuclear Power Generation in the United States," Report No. 92, National Council on Radiation Protection and Measurement, Washington, D.C. (De-cember 1987).

17. "Radiation Protection Standards," Department of Environmental Sciences and Physiology and the Office of Continuing Education, Harvard School Of Public Health, Boston, MA.

(July 1989).

18. Radiological Environmental Monitoring Report for Three Mile Island Station," GPU Nuclear Corporation, Middletown, PA. (1985).

19. "Sources, Effects and Risk of Ionizing Radiation," United Nations Scientific Committee on the Effects of Atomic Radiation, 1988 Report to the General Assembly, United Nations, New York (1988).

20. "Standards for Protection Against Radiation," Title 10, Part 20, Code of Federal Regulation, Washington, D.C. (1988).

21. "Domestic Licensing of Production and Utilization Facilities," Title 10, Part 50, Code of Federal Regulations, Washington, D.C. (1988).

22. "Environmental Radiation Protection Standard for Nuclear Power Operations," Title 40, Part 190, Code of Federal Regulations, Washington, D.C. (1988).

23. Tritium in the Environment," Report No. 62, National Council on Radiation Protection and Measurement, Washington, D.C. (March 1979).

24. Site Environmental Report, Femald Environmental Management Project, United States De-partment of Energy (June 1993).

25. " Exposure from the Uranium Series with Emphasis on Radon and it's daughters" Report No.

77, National Council on Radiation Protection and Measurements, Washington, D.C. (1984).

26. "Evaluation of Occupational and Environmental Exposures to Radon and Radon daughter in the United States, " Report No. 78, National Council on Radiation Protection and Measure-ments, Washington, D.C. (1984).

25

Radiological Environmental Monitoring Program Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Radiological Environmental Monitoring Program Introduction The Radiological Environmental Monitoring Program (REMP) was established at Davis-Besse for several reasons: to provide a supplementary check on the adequacy of containment and effluent controls, to assess the radiological impact of the Station's operation on the surrounding area, and to determine compliance with applicable radiation protection guides and standards. The REMP was established in 1972, five years before the Station became operational. This pre-operational surveillance program was established to describe and quantify the radioactivity, and its variability, in the area prior to the operation of Davis-Besse. After Davis-Besse became operational in 1977, 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 Davis-Besse. The se-lection of sample types is based on the established critical pathways for the transfer of radionu-clides through the environment to humans. The selection of sampling locations is based on sample availability, local meteorological and hydrological characteristics, local population char-acteristics, 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 effect in both biological and physical environments.

A description of the REMP at Davis-Besse is provided in the following section. In addition, a brief history of analytical results for each sample type collected since 1972, and a more detailed summary of the analyses performed during this reporting period, is also provided.

Pre-operational Surveillance Program The federal government requires nuclear facilities to conduct radiological environmental moni-toring prior to constructing the facility. This pre-operational surveillance program is for the col-lection of data needed to identify critical pathways, including selection of radioisotope and sample media combinations for the surveillance conducted after facility operation begins. Ra-diochemical analyses performed on the samples should include both nuclides expected to be re-leased during facility operation, and typical fallout radionuclides and natural background radioactivity. All environmental media with a potential to be affected by facility operation, as well as those media directly in the critical pathways, should be sampled during the pre-operational phase of the environmental surveillance program.

The pre-operational surveillance design, including nuclide/media combinations, sampling fre-quencies and locations, collection techniques,- and radioanalyses performed, should be carefully considered and incorporated in the design of the operational surveillance program. In this man-ner, data can be compared in a variety of ways (for example: from year to year, location to loca-26

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report tion, etc.) in order to detect any radiological impact the facility has on the surrounding environ-ment. Data collection during the pre-operational phase should be planned to provide a compre-hensive database for evaluating any future changes in the environment surrounding the nuclear facility.

Davis-Besse began its pre-operational environmental surveillance program five years before the Station began producing power for commercial use in 1977. Data accumulated during those early years provide an extensive database from which Station personnel are able to identify trends in the radiological characteristics of the local environment. The environmental surveillance pro-gram at Davis-Besse will continue after the Station has reached the end of its economically use-ful life and decommissioning has begun.

Operational Surveillance Program Objectives The operational phase of the environmental surveillance program at Davis-Besse was designed with the following objectives in mind:

• to fulfill the obligations of the radiological surveillance sections of the Sta-tion's Technical Specifications and Offsite Dose Calculation Manual

• to determine whether any significant increase in the concentration of radionu-clides in critical pathways occurs

• to identify and evaluate the buildup, if any, of radionuclides in the local envi-ronment, or any changes in normal background radiation levels

• to veiify the adequacy of Station controls for the release of radioactive mate-rials Quality Assurance An important part of the environmental monitoring program at Davis-Besse is the Quality Assurance (QA) Program, which is conducted in accordance with the guidelines specified in NRC Regulatory Guide 4.15, "Quality Assurance for Radiological Monitoring Programs." The QA Program is designed to identify possible deficiencies in the REMP so that corrective actions can be initiated promptly. Davis-Besse's Quality Assurance program also provides confidence in the results of the REMP through:

• performing regular audits (investigations) of the REMP, including a careful examination of sample collection techniques and record keeping

• performing audits of contractor laboratories which analyze the environmental samples

• requiring analytical contractor laboratories to participate in the United States Environmental Protection Agency Cross Check Program

• requiring analytical contractor laboratories to split samples for separate analy-sis followed by a comparison of results

• splitting samples prior to analysis by independent laboratories, and then com-paring the results for agreement 27

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report

• requiring analytical contractor laboratories to perform in-house spiked sample analyses Quality Assessment audits, and inspections of the Davis-Besse REMP are performed by the FirstEnergy Nuclear Operating Company QA Department and the NRC. In addition, the NRC and the Ohio Department of Health (ODH) also perform independent environmental monitoring in the vicinity of Davis-Besse. The types of samples collected and the sampling locations used by the NRC and ODH were incorporated in Davis-Besse's REMP. Hence, the analytical results from the different programs can be compared. This practice of comparing results from identical samples, collected and analyzed by different parties, provides a valuable tool to verify the quality of the laboratories analytical procedures and the data generated.

In 1987, environmental sampling personnel at Davis-Besse incorporated their own QA program into the REMP. Duplicate samples, called quality control samples, were collected at several lo-cations. These duplicate samples were assigned different identification numbers than the num-bers assigned to the routine samples. This ensured that the analytical laboratory would not know the samples were identical. The laboratory results from analysis of the quality control samples and the routine samples could then be compared for agreement. Quality control sampling has been integrated into the program and has become an important part of the REMP since 1987.

Quality control sampling locations are changed frequently in order to duplicate as many sampling locations as possible, and to ensure the contractor laboratory has no way of correctly pairing a quality control sample with its routine sample counterpart.

Program Description The Radiological Environmental Monitoring Program (REMP) at Davis-Besse is conducted in accordance with Title 10, Code of Federal Regulations, Part 50; Regulatory Guide 4.8; the Davis-Besse Nuclear Power Station Operating License, Appendix A (Technical Specifications); the Davis-Besse Offsite Dose Calculation Manual (ODCM) and Station Operating Procedures.

Samples are collected weekly, monthly, quarterly, semiannually, or annually, depending upon the sample type and nature of the radionuclides of interest. Environmental samples collected by Davis-Besse personnel are divided into four general types:

• atmospheric -- including samples of airborne particulates and airborne radio-iodine

• terrestrial -- including samples of milk, groundwater, broad leaf vegetation, fruits, animal/wildlife feed, soil, and wild and domestic meat

• aquatic -- including samples of treated and untreated surface water, fish, and shoreline sediments

• direct radiation -- measured by thermoluminescent dosimeters All environmental samples are labeled using a sampling code. Table 2 provides the sample codes and collection frequency for each sample type.

REMP samples are collected onsite and offsite up to 25 miles away from the Station. Sampling locations may be divided into two general categories: indicator and control. Indicator locations are those which would be most likely to display the effects caused by the operation of Davis-28

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Besse, and are located within five miles of the station. Control locations are those which should be unaffected by Station operations, and are more than five miles from the Station. Data from indicator locations are compared with data from the control locations. This comparison allows REMP personnel to take into account naturally-occurring background radiation or fallout from weapons testing in evaluating any radiological impact Davis-Besse has on the surrounding envi-ronment. Data from indicator and control locations are also compared with pre-operational data to determine whether significant variations or trends exist.

Since 1987 the REMP has been reviewed and modified to develop a comprehensive sampling program adjusted to the current needs of the utility. Modifications have included additions of sampling locations above the minimum amount required in the ODCM and increasing the num-ber of analyses performed on each sample. Besides adding new locations, duplicate or Quality Control (QC) sample collection was initiated to verify the accuracy of the lab analyzing the envi-ronmental samples. These additional samples are referred to as the REMP Enhancement Sam-ples. Approximately 2000 samples were collected and over 2300 analyses were performed during 2002. In addition, 15% of the sampling locations were quality control sampling locations.

Table 3 shows the number of the sampling location and number collected for each type.

29

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Table 2: Sample Codes and Collection Frequencies Sample Collection Sample Type Code Frequency Airborne Particulate AP Weekly Airborne Iodine Al Weekly Thermoluminescent TLD Quarterly, Annually Dosimeter Milk MIL Monthly (semi-monthly during grazing season)

Groundwater WW Quarterly Broadleaf Vegetation BLV Monthly (when available)

Surface Water - Treated SWT Weekly Surface Water - sWU Weekly Untreated (lake water - monthly in summer)

Fish FIS Annually Shoreline Sediment SED Semiannually Soil Sol Semiannually Animal/Wildlife Feed DFE/WFE Annually Meat-Domestic DME Annually Meat-Wild WME Annually Fruit FRU Annually 30

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Table 3: Sample Collection Summary Sample Collection Number of Number of Number of Type Type*/ Locations Samples Samples (Remarks) Frequency** Collected Missed Atmospheric Airbome Particulates C/W 10 519 1 Airborne Radioiodine C/W 10 519 I Terrestrial Milk (Jan.-Dec.) G/M I 12 0 Groundwater GIQ*** 2 12 0 Domestic Meat G/A 2 2 0 Wild Meat G/A 2 2 0 Broadleaf Vegetation G/M 3 12 0 Fruit GIA 3 3 0 Soil G/SA 10 20 0 Animal/Wildlife Feed G/A 5 5 0 Aquatic Treated Comp/WM 4 208 0 Surface Water G/WM*** I 52 0 Untreated G/WM*** 3 156 0 Surface Water Comp/WM 3 156 0 G/M 5 35 0 Fish (3 species) GIA 2 6 0 Shoreline Sediments G/SA 5 10 0 Direct Radiation Thermoluminescent C/Q*** 88 422 2 Dosimeters (TLD) C/A*** 88 103 3

• Type of Collection: C = Continuous; G = Grab; Comp = Composite

• • Frequency of Collection: WM = Weekly composite Monthly; W = Weekly

• • • Includes quality control location, SWU and SWT QC included in weekly grab samplelcomposited monthly

• • • • Hazardous weather conditions prevented sample collection SM = Semimonthly; M = Monthly; Q = Quarterly; SA = Semiannually; A = Annually 31

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Sample Analysis When environmental samples are analyzed, several types of measurements may be performed to provide information about the radionuclides present. The major analyses that are performed on environmental samples collected for the Davis-Besse REMP include:

Gross beta analysis measures the total amount of beta emitting radioactive material present in a sample. Beta radiation may be released by many different radionuclides. Since beta decay gives a continuous energy spectrum rather than the discrete lines or "peaks" associated with gamma radiation, identification of specific beta emitting' nuclides is much more difficult. Therefore, gross beta analysis only indicates whether the sample contains normal or abnormal concentra-tions of beta emitting radionuclides, it does not identify specific radionuclides. Gross beta analy-sis merely acts as a tool to identify samples that may require further analysis.

Gamma spectral analysis provides more specific information than does gross beta analysis.

Gamma spectral analysis identifies each gamma emitting radionuclide present in the sample, and the amount of each nuclide present. Each radionuclide has a very specific "fingerprint" that al-lows for swift and accurate identification. For example, gamma spectral analysis can be used to identify the presence and amount of Iodine-131 in a sample. Iodine-131 is a man-made radioac-tive isotope of Iodine that may be present in the environment as a result of fallout from nuclear weapons testing, routine medical uses in diagnostic tests, and routine releases from nuclear power stations.

Tritium analysis indicates whether a sample contains the radionuclide tritium (H-3) and the amount present. As discussed in the Introduction Section, tritium is an isotope of Hydrogen that emits low energy beta particles.

Strontium analysis identifies the presence and amount of Strontium-89 and Strontium-90 in a sample. These man-made radionuclides are found in the environment as a result of fallout from nuclear weapons testing. Strontium is usually incorporated into the pool of the biosphere. In other words, Strontium tends to replace in living organisms and becomes incorporated in bone tissue. The principal Strontium exposure pathway is via milk produced by cattle grazed on pas-tures exposed to deposition from airborne releases.

Gamma Doses measured by thermoluminescent dosimeters while in the field are determined by a special laboratory procedure. Table 4 provides a list of the analyses performed on environ-mental samples collected for the Davis-Besse REMP.

Often samples will contain little radioactivity, and may be below the lower limit of detection for the particular type of analysis used. The lower limit of detection (LLD) is the smallest amount of sample activity that can be detected with a reasonable degree of confidence, at a predetermined level. When a measurement of radioactivity is reported as less than LLD (<LLD), it means that the radioactivity is so low that it cannot be accurately measured with any degree of confidence by that particular method for an individual analysis.

32

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Table 4: Radiochemical Analyses Performed on REMP Samples Sample Type Analyses Performed Atmospheric Monitoring Airborne Particulate Gross Beta Gamma Spectral Strontium-89 Strontium-90 Airborne Radioiodine Iodine-13 1 Terrestrial Monitoring Milk Gamma Spectral Iodine-131 Strontium-89 Strontium-90 Stable Stable Potassium Groundwater Gross Beta Gamma Spectral Tritium Strontium-89 Strontium-90 Broadleaf Vegetation Gamma Spectral and Fruits Iodine-131 Strontium-89 Strontium-90 Animal/Wildlife Feed Gamma Spectral Soil Gamma Spectral Wild and Domestic Meat Gamma Spectral 33

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Table 4: Radiochemical Analyses Performed on REMP Samples (continued)

Sample Type Analyses Performed Aquatic monitoring Untreated Surface Water Gross Beta Gamma Spectral Tritium Strontium-89 Strontium-90 Treated Surface Water Gross Beta Gamma Spectral Tritium Strontium-89

-Strontiurn-90 Iodine-131 Fish Gross Beta Gamma Spectral Shoreline Sediment Gamma Spectral Direct Radiation Monitoring Thermoluminescent Dosimeters Gamma Dose Sample History Comparison The measurement of radioactive materials present in the environment will depend on factors such as weather or variations in sample collection techniques or sample analysis., This is one reason why the results of sample analyses are compared with results from other locations and from ear-lier years. Generally, the results of sample analyses are compared with pre-operational and op-erational data. Additionally, the results of:;indicator and-control locations are also compared.

This allows REMP personnel to track and trend the radionuclides present in the environment, to assess whether a buildup of radionuclides is occurring and to determine. the effects, if any,-the operation of Davis-Besse is having on the environment. If any unusual activity is detected, it is investigated to determine whether it is attributable to the operation of Davis-Besse, or to some other source such as nuclear weapons testing.

34

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Atmospheric Monitoring

• Airborne Particulates: No radioactive particulates have been detected as a result of Davis-Besse's operation. Only natural and fallout radioactivity from nuclear weapons testing and the 1986 nuclear accident at Chemobyl have been detected.

• Airborne Radioiodine: Radioactive Iodine-131 fallout was detected in 1976, 1977, and 1978 from nuclear weapons testing, and in 1986 (0.12 to 1.2 pico-curies per cubic meter) from the nuclear accident at Chemobyl.

Terrestrial Monitoring:

• Groundwater: Tritium was detected at Indicator site T-225 at 440 pCi/L in January of 2002, and could be attributable to the operation of the Davis-Besse plant. This beach well is not used for drinking water purposes.

• Milk: Iodine-131 from nuclear weapons testing fallout was detected in 1976 and 1977 at concentrations of 1.36 and 23.9 picocuries/liter respectively. In 1986, concentrations of 8.5 picocuries/liter were detected from the nuclear accident at Chernobyl. No Iodine-131 detected has been attributable to the operation of Davis-Besse.

• Domestic and Wild Meat: Only naturally occurring Potassium-40 and very low Cesium-137 from fallout activity has been detected in meat samples. Po-tassium-40 has ranged from 1.1 to 4.6 picocuries/gram weight (wet). Cesium-137 was detected in 1974, 1975, and 1981 due to fallout from nuclear weap-ons testing.

• Broadleaf Vegetation and Fruits: Only naturally-occurring radioactive mate-rial and material from nuclear weapons testing have been detected.

• Soil: Only natural background and material from nuclear weapons testing and the 1986 nuclear accident at Chemobyl have been detected.

• Animal/Wildlife Feed: Only natural background and material from weapons testing have been detected.

Aquatic Monitoring

• Surface Water (Treated and Untreated): Historically, tritium has been de-tected sporadically at low levels in treated and untreated surface water at both Control and Indicator locations. In 2002, no tritium was detected above the detection limit of 330 pCi/L at any treated or untreated surface water sites.

The allowable effluent concentration limit of 20,000 pCi/L in an unrestricted area is stated in 40CFR 141.

• Fish: Only natural background radioactive material and material from nuclear testing have been detected.

35

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report

• Shoreline Sediments: Only natural background, material from nuclear testing and from the 1986 nuclear accident at Chemobyl have been detected.

Direct Radiation Monitoring

• Thermoluminescent Dosimeters (TLDs): The annual average gamma dose rates for the current reporting period recorded by TLDs have ranged from 50.2 to 82.2 millirem per year at Control locations and between 36.5 and 95.6 mil-lirem per year at Indicator locations. No increase above natural background radiation attributable to the operation of Davis-Besse has been observed.

2002 Program Anomalies -

All required samples were collected during 2002. Provided below is a description of 2002 sam-ple collection irregularities:

• Broadleaf vegetation was only collected between the months of July through October because of seasonal availability.

• The TLD located at the South Bass Island lighthouse (T-23) was eliminated from the program in 2002. It was not a required sample, and was not associated with any other sampling in the area.

• On 1/8/02, the sampling line for the raw water auto-sampler at the Carroll Township intake structure was clogged with silt. The line was cleared and a sample was collected. The sam-pling location was moved to the Carroll Township Treatment Plant, and now supplies a rep-resentative sample without the associated clogging.

• On 4/10/02, TLDs at sample location T-223 were missing. New TLDs were installed. This is not an ODCM-required sample.

• On 7/5/02, quarterly and annual TLDs were missing at sample location T-153. The quarterly TLD at this location was replaced. Annual TLDs were missing at locations T-124 and T-223.

None of these samples were ODCM-required.

• 7/9/02, storm-related power outages caused a loss of sampling capability for three air sam-plers. All three samplers (T-27, T-7, and T-8) had enough collection time to provide valid samples. One pump was damaged in the storm, and it was replaced.

• On 7/23/02, air sampler T-3 was found to be inoperable due to thunderstorms. Four other air samplers were missing time during this sampling period. There were sufficient hours to col-lect valid samples on all of the affected samplers. The inoperable pump had a fuse replaced and was returned to service, and the other pumps were verified as being operable.

• On 7/30/02, air sampler T-3 was found to be inoperable due to a damaged fuse holder. This damage was likely caused by the storms of the previous week, when its fuse was blown. Suf-ficient sample was collected for a valid sample. The pump was replaced with a new one. Air sampler T-8 was found with a stuck timer, which was replaced in the field.

36

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report

• On 8/6/02, five air samplers were found with timer readings about 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> less than elapsed time. The load dispatcher verified that the loss of hours was due to storm-related outages.

Samples were valid.

• On 8/20/02, air sampler T-1 would not run properly after being temporarily powered by a generator during a Station maintenance outage. The sampler was replaced. Also on this date, a greater than 1% difference was noted between the actual time and the elapsed time on air sampler T-8. The cause was electrical maintenance on the power source for this sampler.

Samples were valid.

• Two power outages during the sampling period caused a greater than 1% difference between timer and actual readings at T-1, T-2 and T-3. Total down time was about 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Samples were valid.

• A tornado caused the loss of about 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> on the Port Clinton air sampler at T-11 on 11/12/02. Sufficient sample was collected for the analysis.

• A faulty timer caused a greater than 1% difference on air sampler T-4 on 11/26/02. The pump was replaced and repaired. Sample was valid.

• On 12/31/02, a broken wire on air sampler T-1 prompted the replacement of the pump. Sam-ple T-4 was used to replace T-1 as the third required sample at the site boundary during this time period.

37

Davis-Besse Nuclear Power Station 2002 Annual Radiological Envirorunental Operating Report Atmospheric Monitoring

-r.. ,.

Air Samples Environmental air sampling is conducted to detect any increase in the concentration of airborne radionuclides that may be inhaled by humans or serve as an external radiation source. Inhaled radionuclides may be absorbed from the lungs, gastrointestinal tract, or from the skin. Air sam-ples collected by the Davis-Besse REMP include both airborne particulate and airborne ra-dioiodine.

Samples are collected weekly with low volume vacuum pumps, which draw a continuous sample through a glass fiber filter and charcoal cartridge at a rate of approximately one cubic foot per minute. Airborne particulate samples are collected on 47mm diameter filters. Charcoal car-tridges are installed downstream of the particulate filters to sarnple for the airborne radioiodine.

The airborne sarnples are sent to an offsite contract laboratory for analysis. At the laboratory, the airborne particulate filters are stored for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before they are analyzed to allow for the decay of naturally-occurring short-lived radionuclides. However, due to the short half-life of iodine-131 (approximately eight days), the airbome radioiodine cartridges are analyzed upon receipt by the contract laboratory.

38

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Airborne Particulate Davis-Besse continuously samples air for airborne radionuclides at ten locations. There are six indicator locations including four around the site boundary (T-1, T-2, T-3, and T-4), one at Sand Beach (T-7), and another at a local farm (T-8). There are four control locations, Oak Harbor (T-9), Port Clinton (T-11), Toledo (T-12) and Crane Creek (T-27). Gross beta analysis is per-formed on each of the weekly samples. Each quarter, the filters from each location are combined (composite) and analyzed for gamma-emitting radionuclides, Strontium-89 and Strontium-90.

Beta-emitting radionuclides were detected at the indicator and control locations at average con-centration of 0.025 pCi/m 3 and 0.025 pCi/m3 , respectively. Beryllium-7 was the only gamma emitting radionuclide detected by the gamma spectroscopic analysis of the quarterly composites.

Beryllium-7 is a naturally-occurring radionuclide produced in the upper atmosphere by cosmic radiation. No other gamma-emitting radionuclides were detected above their respective LLDs.

Strontium-89 and Strontium-90 were not detected above their LLDs. These results show no ad-verse change in radioactivity in air samples attributable to the operation of the Davis-Besse Nu-clear Power Station in 2002.

Airborne Iodine- 131 Airborne iodine-131 samples are collected at the same ten locations as the airborne particulate samples. Charcoal cartridges are placed downstream of the particulate filters. These cartridges are collected weekly, sealed in separate collection bags and sent to the laboratory for gamma analysis. There was no detectable iodine-131 above the LLD of 0.07 pCi/m3 .

202IrbnPktQmBa QC35 0.

QCa; QO1 CL Ibtny Febtay Ntt AOt My% ~J- AgA avtw od- N-nt- Dmt Figure 10: Concentrations of beta-emitting radionuclides in airborne particulate samples were nearly identical at indicator and control locations.

39

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Table 5: Air Monitoring Locations Sample Location Type of Number Location Location Description T-1 I Site boundary, 0.6 miles ENE of Station T-2 I Site boundary, 0.9 miles E of Station T-3 I Site boundary, 1.4 miles ESE of Station T-4 I Site boundary, 0.8 miles S of Station T-7 I Sand Beach, main entrance, 0.9 miles NW of Station T-8 I Earl Moore Farm, 2.7 miles WSW of Station T-9 C Oak Harbor Substation, 6.8 miles SW of Station T-11 C Port Clinton Water Treatment Plant, 9.5 miles SE of Station T-12 C Toledo Water Treatment Plant, 20.7 miles WNW of Station T-27 C Crane Creek State Park, 5.3 miles WNW of Station I = Indicator C = Control 40

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Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report Terrestrial Monitoring The collection and analysis of groundwater, milk, meat, fruits and broad leaf vegetation provides data to assess the buildup of radionuclides that may be ingested by humans. Animal and wildlife feed samples provide additional information on radionuclides that may be present in the food chain. The data from soil sampling provides information on the deposition of radionuclides from the atmosphere.

Many radionuclides are present in the environment due to sources such as cosmic radiation and fallout from nuclear weapons testing. Some of the radionuclides present are:

tritium, present as a result of the interaction of cosmic radiation with the upper atmosphere and as a result of routine release from nuclear facilities

. Beryllium-7, present as a result of the interaction of cosmic radiation with the upper atmosphere

. Cesium-137, a manmade radionuclide which has been deposited in the environment, (for example, in surface soils) as a result of fallout from nu-clear weapons testing and routine releases from nuclear facilities Potassium-40, a naturally occurring radionuclide normally found through-out the environment (including in the human body)

• fallout radionuclides from nuclear weapons testing, including Strontium-89, Strontium-90, Cesium-137, Cerium-141, Cerium-144, and Ruthenium-106. These radionuclides may also be released in minute amounts from nuclear facilities The radionuclides listed above are expected to be present in many of the environmental samples collected in the vicinity of the Davis-Besse Station. The contribution of radionuclides from the operation of Davis-Besse is assessed by comparing sample results with pre-operational data, op-erational data from previous years, control location data, and the types and amounts of radioac-tivity normally released from the Station in liquid and gaseous effluents.

Milk Samples Milk sampling is a valuable tool in environmental surveillance because it provides a direct basis for assessing the build up of radionuclides in-the environment'that may be ingested by humans.

Milk is collected and analyzed because it is one of the few foods commonly consumed soon after production. The milk pathway'involves the deposition of radionuclides from atmospheric re-leases onto forage consumed by cows. The radionuclides present in the forage-eating cow be-come incorporated into the milk, which is' then consumed by humans.

When available, milk samples are collected at indicator and control locations once a month from November through April, and twice a month between May and October. Sampling is increased in the summer when the herds are usually outside on pasture and not on stored feed. In Decem-ber of 1993, indicator location T-8 was eliminated from the sampling program, and no other in-dicator milk site has existed since that time. The control location will continue to be sampled 44

Davis-Besse Nuclear Power Station 2002 Annual Radiological Environmental Operating Report monthly in order to gather additional baseline data. If any dairy animals are discovered within five miles of the station, efforts will be made to include them in the milk-sampling program as indicator sites.

The 2002 milk samples were analyzed for Strontium-89, Strontium-90, iodine-131, other gamma-emitting radionuclides, stable and Potassium. A total of 12 milk samples were collected in 2002. Strontium-89 was not detected above its LLD. Strontium-90 was detected in all but one sample collected. The annual average concentration of Strontium-90 was 1.1 pCi/l. For all sam-ple sites, the annual average concentration was similar to those measured in the previous years.

Iodine-131 was not detected in any of the milk samples above the LLD of 0.5 pCi/l. The con-centrations of Barium-140 and Cesium-137 were below their respective LLDs in all samples collected.

Since the chemistries of and Strontium are similar, as are Potassium and Cesium, organisms tend to deposit Cesium radioisotopes in muscle tissue and Strontium radioisotopes in bones. In order to detect the potential environmental accumulation of these radionuclides, the ratios of the Strontium radioactivity (pCi/I) to the concentration of (g/l), and the Cesium radioactivity (pCi/I) compared to the concentration of Potassium (g/l) were monitored in milk. These ratios are com-pared to standard values to determine if buildup is occurring. No statistically significant varia-tions in the ratios were observed.

Table 6: Milk Monitoring Location Sample Location Type of Number Location Location Description T-24 C Toft Dairy, Sandusky, 21.0 miles SE of Station C = Control Groundwater Samples Soil acts as a filter and an ion exchange medium for most radionuclides. However, tritium and other radionuclides such as Ruthenium-106 have a potential to seep through the soil and could reach groundwater. Davis-Besse does not discharge its liquid effluents directly to the ground. In the past, REMP personnel sampled local wells on a quarterly basis to ensure early detection of any adverse impact on the local groundwater supplies due to Station operation. In addition, a quality control sample was collected at one of the wells each quarter. The groundwater samples were analyzed for beta-emitting radionuclides, tritium, Strontium-89, Strontium-90 and gamma-emitting radionuclides.

During the fall of 1998, the Carroll Township Water Plant began operation and offered residents a reliable source of high-quality, inexpensive drinking water. This facility has replaced all of the 45