ML091350081

Power Plant Research Program Environmental Radionuclide Concentrations in the Vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 2004-2005.

ML091350081
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Site:	Peach Bottom, 05200016
Issue date:	04/30/2008
From:	Hood B, Jones T, Mclean R State of MD, Dept of Natural Resources, Versar
To:	Office of New Reactors
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+reviewedjr, PPRP-R-30 DNR 12-422008-296
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MARYLAND DNR 12-422008-296 SDEPAF'TMENT OF NATURAL RESOURCES PPRP-R-30 I

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,I F-ENVIRONMENTAL RADIONUCLIDE CONCENTRATIONS IN THE VICINITY OF THE CALVERT CLIFFS NUCLEAR POWER PLANT AND THE PEACH BOTTOM ATOMIC POWER STATION: 2004-2005 April 2008 I

MARYLAND POWER PLANT U RESEARCH PROGRAM i

Martin O'Malley, Governor

• Anthony G. Brown, Lt. Governor I

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.I The Maryland Department of Natural Resources (DNR) seeks to preserve, protect and enhance the living resources of the State. Working in partnership with the citizens of Maryland, I this worthwhile goal will become a reality. This publication provides information that will increase your understanding of how DN R strives to reach that goal through its many diverse programs. I John R. Griffin, Secretary Maryland Department of Natural Resources I U

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This document is available in alternative format upon request from a qualified individual with a disability.

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PPRP-R-30 ENVIRONMENTAL RADIONUCLIDE CONCENTRATIONS IN THE VICINITY OF THE CALVERT CLIFFS NUCLEAR POWER PLANT AND PEACH BOTTOM ATOMIC POWER STATION: 2004-05 Thomas S. Jones Brent S. Hood Versar, Inc.

9200 Rumsey Road Columbia, Maryland 21045 and Richard I. McLean Power Plant Research Program Maryland Department of Natural Resources Tawes State Office Building Annapolis, Maryland 21401 April 2008

Foreword FOREWORD This report, Environmental Radionuclide Concentrations in the Vicinity of the Calvert Cliffs Nuclear Power Plant and The Peach Bottom Atomic Power Station: 2004-2005, contains the results of monitoring and research programs conducted by the Maryland Department of Natural Resources, Power Plant Research Program (PPRP), to evaluate the fate and effects of radionuclides released from the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station in 2004 and 2005. This is the 17th in a series of radiological assessment reports detailing PPRP's monitoring efforts since 1975. This report was prepared under Contract Numbers K00B0200109 and KOOB5200176 between the Maryland Department of Natural Resources, Power Plant Research Program, and Versar, Inc.

The authors thank Captain Rick Younger and Jake Hollinger of the R/V Kerhin (Maryland Geological Survey) for assistance with the collection of sediments for radiological analysis. We thank Mr. George R. Abbe and staff (Morgan State University, Estuarine Research Center) for designing equipment and collecting oyster samples. We also thank Craig Bruce, Martin Berlett, Megen McBride, J. Peyton Emerson, and Katherine Dillow of Versar, Inc. for collecting samples of sediment and biota. We also thank Constellation Energy Group for providing radionuclide-release data for the Calvert Cliffs Nuclear Power Plant and Exelon Nuclear for providing radionuclide-release data for the Peach Bottom Atomic Power Station.

Brent Hood and Bradford Johnson provided assistance with sediment and biological sample collection, sample preparation, sediment particle size analysis, and reduction of radiological data for incorporation into a computer database. Brent Hood prepared tables and graphics from accumulated data. Jodi Dew provided assistance with data quality control, results calculation, and management of the long-term database. Carol DeLisle provided technical editing, and Sherian George supervised the production of this report.

The preferred citation for this report is:

Jones, T.S. et al. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 2004-2005. PPRP-R-30. April 2008. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

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Foreword iv

Abstract ABSTRACT The Maryland Power Plant Research Program monitors concentrations of natural, weapons-related, and power plant-produced radionuclides in environmental samples collected from Chesapeake Bay in the vicinity of the Calvert Cliffs Nuclear Power Plant (CCNPP) and from the Susquehanna River-Chesapeake Bay system in the vicinity of Peach Bottom Atomic Power Station (PBAPS). The purpose of this monitoring is to determine the fate, transport, and potential effects of radionuclides released from power plants. This report describes monitoring activities and data collected during the 2004 and 2005 calendar years and is the 1 7th in a series that documents results of monitoring studies conducted at CCNPP since 1975 and at PBAPS since 1979.

Radionuclide concentrations in shellfish, finfish, aquatic vegetation, and sediment were measured using high-resolution gamma spectrometry. Radionuclides in environmental samples originated from natural sources, historic atmospheric testing of weapons, and normal operations of CCNPP and PBAPS. Naturally occurring radioactive isotope of potassium (40 K) and decay products of uranium and thorium were detected in most samples of biota and all samples of sediment collected during the monitoring period.

Concentrations of naturally occurring radionuclides were typically orders of magnitude greater than those of radionuclides released from power plants. Cesium-1 37 was the only radionuclide associated with the fallout from weapons testing detected in environmental samples collected in 2004 and 2005.

Small concentrations of radionuclides originating from CCNPP and PBAPS were detected in many of the sediment samples collected in the vicinity of the plants. The principal plant-related radionuclide was an isotope of cobalt (6"Co) detected in sediments at PBAPS. Radionuclides attributable to CCNPP and PBAPS represented a small fraction of the total radionuclides detected in the sediments and biota collected near CCNPP and PBAPS. The estimated dose of radiation that biota near power plants could deliver to humans did not exceed any of the U.S. Nuclear Regulatory Commission's action levels.

The concentrations of radionuclides found in sediments and biota during this monitoring period do not represent a risk to the ecological health of Chesapeake Bay or Susquehanna River. The incremental contribution of radioactivity and the corresponding dose of radiation attributable to the operation of CCNPP and PBAPS are minimal when compared with natural levels of radioactivity and the associated natural dose of radiation.

The concentrations of radionuclides in sediments and biota would increase the radiological dose to humans by no more than 0.001 %.

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Abstract

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Table of Contents TABLE OF CONTENTS

.. Page FOREW ORD ........................................................................................................ iiii ABSTRACT ............................................................................................................. v ACRONYMS, CHEMICAL ABBREVIATIONS, AND UNITS OF MEASUREMENT ................ xiii RADIOLOGICAL DEFINITIONS .................................................................................. xv

1.0 INTRODUCTION

......................................................................................... 1-1 1.1 MONITORING OBJECTIVES ................................................................ 1-1

1.2 DESCRIPTION

OF PLANTS AND STUDY SITES ..................................... 1-2 1.2.1 Calvert Cliffs Nuclear Power Plant ............................................. 1-2 1.2.2 Peach Bottom Atomic Power Station ....................................... 1-3 2.0 METHODS AND MATERIALS ........................................................................ 2-1 2.1 SAMPLE COLLECTION ....................................................................... 2-1 2.1.1 Sediments .............................................................................. 2-4 2.1.2 Biota ..................................................................................... 2-4 2.2 MEASUREMENT OF GAMMA-EMITTING RADIONUCLIDES IN BIOTA AND SEDIMENTS .............................................................................. 2-4 2.2.1 Sample Preparation ................................................................. 2-4 2.2.2 Gamma Spectrometry .............................................................. 2-5 2.3 DETERMINATION OF SEDIMENT CHARACTERISTICS ............................ 2-6 2.4 DATA ANALYSIS .............................................................................. 2-6 2.5 DETERMINATION OF POW ER PLANT CESIUM-1 37 ............................... 2-6 2.6 DATA PRESENTATION ...................................................................... 2-8 3.0 RESULTS AND DISCUSSION ........................................................................ 3-1 3.1 SOURCES OF RADIONUCLIDES .......................................................... 3-1 3.1.1 Radionuclides from CCNPP and PBAPS ...................................... 3-1 3.1.2 Natural Radionuclides .............................................................. 3-8 3.1.3 Radionuclides from W eapons Tests ........................................... 3-9 3.2 RADIONUCLIDES IN ENVIRONMENTAL SAM PLES ................................. 3-9 3.2.1 Sediments .............................................................................. 3-9 3.2.2 Biota ................................................................................... 3-16 3.3 RADIOLOGICAL EFFECTS ON THE ENVIRONMENT AND HUMAN HEALTH ........................................................................................ 3-18 3.3.1 Effect on the Environment ...................................................... 3-18 3.3.2 Effect on Human Health ......................................................... 3-18 vii

Table of Contents TABLE OF CONTENTS (Continued)

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4.0 CONCLUSION

S .......................................................................................... 4-1

5.0 REFERENCES

............................................................................................. 5-1 APPENDICES A COORDINATES OF SAMPLING STATIONS ................................................ A-1 B CONCENTRATIONS OF RADIONUCLIDES IN ENVIRONMENTAL SAMPLES .... B-1 22\dnrO8\radio\ 14245-r.doc viii

List of Figures LIST OF FIGURES Figure Page-2-1 Transects and stations for samples collected from Chesapeake Bay ................... 2-2 2-2 Transects and stations for samples collected from lower Susquehanna River and upper Chesapeake Bay .................................................................. 2-3 3-1 Relative contributions of noble gases, tritium, and environmentally significant radionuclides released from CCNPP, 2004-2005 ............................................. 3-2 3-2 Relative contributions of noble gases, tritium, and environmentally significant radionuclides released from PBAPS, 2004-2005 .............................................. 3-3 3-3 Releases of noble gases, tritium, and environmentally significant radionuclides from CCNPP and PBAPS, 2004-2005 ............................................................ 3-4 3-4 Annual aqueous releases of 13 7Cs from CCNPP, 1996-2005 ............................. 3-6 3-5 Annual aqueous releases of 13 7Cs from PBAPS, 1996-2005 .............................. 3-6 3-6 Annual aqueous releases of 6 0Co from CCNPP, 1996-2005 .............................. 3-7 3-7 Annual aqueous releases of 6"Co from PBAPS, 1996-2005 ............................... 3-7 3-8 Mean particle size values for sediments collected from the vicinity of CC NPP, 2004-2005 .................................................................................. 3-10 3-9 Mean particle size values for sediments collected from the vicinity of PBA PS, 2004-2005 .................................................................................. 3-11 3-10 Geographical distribution of average activity of 6 0Co near CCNPP, 20 0 4 -20 0 5 .............................................................................................. 3 -12 3-11 Proportion of gamma-emitting radionuclides in sediment samples .................... 3-13 3-12 Proportion of gamma-emitting radionuclides in sediment samples .................... 3-13 3-13 Total annual release of 137Cs from CCNPP and average annual activity of 137Cs in CCNPP sediments, Flag Ponds transect, 1983-2005 .................................. 3-1 5 3-14 Total annual release of 137 Cs from PBAPS and average annual activity of 137Cs in PBAPS sediments, Broad Creek transect, 1983-2005 ......................... 3-15 ix

I List of Figures I LIST OF FIGURES (Continued) I Figure Number Page I

3-15 Concentration of ilomAg in aqueous effluent from CCNPP and in 3-month tray oysters, 1994-200 5 .................................................................................. 3-17 I x

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List of Tables LIST OF TABLES Table-Number Page 2-1 Environmental samples for radiological analysis collected in 2004-2005 from Chesapeake Bay in the vicinity of CCNPP ............................................... 2-1 2-2 Environmental samples for radiological analysis collected in 2004-2005 from lower Susquehanna River and upper Chesapeake Bay ............................... 2-1 2-3 Determ ination of the lower limit of detection .................................................. 2-7 2-4 Approximate lower limits (99%) of detection for selected counting geom etries (pC i/kg) ..................................................................................... 2-8 3-1 Annual releases (curies) from all pathways of noble gases, tritium, iodines and particulates from CCNPP and PBAPS, 2004-2005 ..................................... 3-4 3-2 Total environmentally significant releases from CCNPP and PBAPS to the aqueous pathw ay, 1996-2005 ................................................................... 3-5 3-3 Quantities of environmentally significant radionuclides released from CCNPP and PBAPS via the aqueous pathway during 2004-2005 .................................. 3-8 3-4 Percent detection frequency of 60Co in CCNPP and PBAPS sediments, 19 9 6 -20 0 5 .............................................................................................. 3-12 3-5 Comparison of 137Cs released from CCNPP and PBAPS and sediment activities at representative transects, 1981 and 2005 .................................... 3-16 3-6 Estimated maximum dose commitments in millirem per year to individuals who consume finfish from Conowingo Pond, 2004-2005 ....................................... 3-19 xi

List of Tables xii

Acronyms, Chemical Abbreviations, and Units of Measurements ACRONYMS, CHEMICAL ABBREVIATIONS, AND UNITS OF MEASUREMENT ACRONYMS BGE - Baltimore Gas and Electric Company BWR - Boiling Water Reactor CCNPP - Calvert Cliffs Nuclear Power Plant DNR - Maryland Department of Natural Resources LLD - Lower Limit of Detection MDE - Maryland Department of the Environment NIST - National Institute of Science of Technology PBAPS - Peach Bottom Atomic Power Station PECO - Philadelphia Electric Company PPRP - Power Plant Research Program PWR - Pressurized Water Reactor USAEC - United States Atomic Energy Commission USEPA - United States Environmental Protection Agency USGS - United States Geological Survey USNRC - United States Nuclear Regulatory Commission CHEMICALS Ag silver Li lithium Ac actinium Na sodium Be beryllium Nb niobium Bi bismuth P phosphorus C carbon Pb lead Ce cerium Ra radium Co cobalt Ru ruthenium Cr chromium Sb antimony Cs cesium Se selenium Cu copper Sr strontium Fe iron Th thorium Ge germanium TI thallium H hydrogen U uranium

.3 H tritium Xe xenon I iodine Zn zinc K potassium Zr zirconium La lanthanum xiii

I Acronyms, Chemical Abbreviations, and Units of Measurements II UNITS OF MEASUREMENT I Ci cm curies centimeters m 3/s mi2 cubic meters per second square miles I

dpm disintegrations per minute min minutes ft3/s ha cubic feet per second hectares mm millimeters mrem millirem I

keV thousand electron volts MW megawatts kg km kilograms kilometers pCi picocuries ppm parts per million I

I liters ppt parts per thousand m meters kim yr micrometers years I

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Radiological Definitions RADIOLOGICAL DEFINITIONS Activity. The quantification of the rate of radioactive decay of radioactive material.

Becquerel. A unit of radioactivity. One becquerel is defined as 1 disintegration per second.

Curie (Ci). A unit of radioactivity. One curie is defined as 3.7 x 1010 disintegrations per second.

Dose. The energy imparted to matter by ionizing radiation. The unit of absorbed dose is the rad, equal to 0.01 joules per kilogram for irradiated material in any medium.

Dose commitment. The dose that an organ or tissue would receive during a specified period of time (i.e., a 50-year period is used in dose calculations in this report) as a result of intake (as by ingestion or inhalation) of one or more radionuclides from one year's release.

Environmentally significant. As used in this report, refers to radionuclides that are known to be assimilated by biological organisms and are discharged in detectable amounts. Not included are aqueous release of noble gases, tritium, or very short-lived radionuclides.

Half-life. The time required for a radioactive substance to lose one-half of its activity by decay. Each radionuclide has a unique half-life.

Ionizing radiation. Any electromagnetic or particulate radiation capable of producing ions (electrically charged atoms or atomic particles), directly or indirectly, in its passage through matter.

Maximally exposed individual. A hypothetical individual who remains in an uncontrolled area and would, when all potential routes of exposure from a facility's operations are considered, receive the greatest possible dose.

Radioactive decay. The spontaneous transformation of one nuclide into a different radioactive or nonradioactive nuclide, or into a different energy state of the same nuclide.

Radionuclide. An unstable nuclide capable of spontaneous transformation into other nuclides by changing its nuclear configuration or energy level. This transformation is accompanied by the emission of photons or particles.

Rem. The effective dose equivalent (i.e., the absorbed dose multiplied by the quality factor associated with the type of radiation).

Stable. Not radioactive or not easily decomposed or otherwise modified chemically.

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Radiological Definitions xvi

Introduction

1.0 INTRODUCTION

The Calvert Cliffs Nuclear Power Plant (CCNPP) and the Peach Bottom Atomic Power Station (PBAPS) generate gaseous and liquid radioactive wastes that are discharged into the atmosphere, and Chesapeake Bay and lower Susquehanna River, respectively.

Although atmospheric releases consist mainly of radioactive noble gases, which have little environmental significance, aqueous discharges to Chesapeake Bay and lower Susquehanna River contain radionuclides that can be accumulated by biota and can become associated with sediments. Ultimately, these radionuclides may contribute to a radiation dose to humans by being transported through the food chain.

This report examines and summarizes the results of monitoring and research programs conducted in the vicinity of CCNPP, lower Susquehanna River, and upper Chesapeake Bay in 2004 and 2005 by the Maryland Department of Natural Resources (DNR), Power Plant Research Program (PPRP). The report includes:

• quantities of environmentally significant radionuclides discharged from the nuclear power plants to Chesapeake Bay and Susquehanna River;

• descriptions of procedures for collecting, preparing, and analyzing environmental samples;

" concentrations of radionuclides measured in approximately 400 samples of aquatic vegetation, shellfish, finfish, and sediment collected from lower Susquehanna River and Chesapeake Bay; and

• an assessment of the environmental and health-related effects of radioactive discharges from CCNPP and PBAPS that were detected in Susquehanna River and Chesapeake Bay.

1.1 MONITORING OBJECTIVES PPRP has conducted research and monitoring to assess the effects of radioactive material released from CCNPP (since 1975) and PBAPS (since 1979) on Maryland's ecological resources. These programs evaluate radiological effects within individual trophic levels of the ecosystems of Chesapeake Bay and Susquehanna River and provide information concerning the behavior and fate of radionuclides released to Chesapeake Bay and Susquehanna River. These monitoring data are also used to estimate the radiological dose to human populations resulting from the discharge of radionuclides from these power plants.

As part of these monitoring efforts, PPRP conducts or sponsors projects that involve exposing shellfish to discharges from CCNPP for a variety of predefined exposure periods to determine the mechanisms that regulate uptake and elimination of radionuclides in specific estuarine organisms. Oysters are important biological indicators of 1-1

I Introduction environmental radionuclide concentrations. Because they are sessile, oysters in the vicinity of CCNPP are more likely to be exposed to aqueous releases of radioactive material than mobile biota such as finfish and crabs.. Oysters filter large amounts of particulate material and plankton that may have adsorbed radionuclides and accumulated heavy metals and radionuclides (McLean et al. 1987). Despite the decline in the commercial oyster fishery in recent years, oysters are still an important indicator of potential radionclide uptake in humans. Other organisms, such as mussels, may also be used to estimate potential plant-related radiation dose commitment.

The radionuclide monitoring conducted by PPRP is focused primarily on discharges to water and transfers within aqueous pathways; however, atmospheric releases of.

radioactive material are also assessed using data collected by Constellation Energy Group, Exelon Nuclear, and Maryland Department of the Environment (MDE 2005, 2006). PPRP biannually publishes the results of these assessments in its Cumulative Environmental I Impact Report for Power Plants in Maryland (CEIR 1975-1991, 1993-2008).

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1.2 DESCRIPTION

OF PLANTS AND STUDY SITES 1.2.1 Calvert Cliffs Nuclear Power Plant I Constellation Generation Group owns and operates CCNPP. The plant is in Calvert County, Maryland, on the western shore of Chesapeake Bay. Each of CCNPP's two units is a pressurized water reactor (PWR) with an operating capacity of 845 megawatts. Unit 1 is licensed to operate until 2034, and Unit 2 until 2036. Controlled releases of radionuclides via the heat dissipation system are permitted at levels defined in CCNPP's license (issued July 31, 1974 for Unit 1 and November 30, 1976 for Unit 2, renewed March 23, 2000) from the United States Nuclear Regulatory Commission (10 CFR Part 20, Appendix B; USNRC 1991). CCNPP withdraws cooling water from Chesapeake Bay at a rate of approximately 2.3 million gallons per minute (CEIR 2008), which is approximately I

four times the withdrawal rate of PBAPS.

The western shore of Chesapeake Bay is scoured by tides, wind, and waves. The Bay in this area is approximately 4.5 km wide and relatively shallow. Water depth gradually increases to 10 to 15 m about 0.8 km from the shoreline. This depth extends approximately 3 km and increases to 20 m at mid-bay. The area is tidally influenced and I

has a mean tidal range of 0.3 to 0.6 m. The velocity of the current in the vicinity ranges between 5 and 60 cm/sec (Lacy and Zeger 1979). Salinity varies seasonally and normally ranges from 7 to 17 ppt. Bottom sediments are characterized by medium coarse sands at I

depths ranging between 0 to 6 m, fine sands and clays at depths of 6 to 9 m, and clays and organic silt at depths greater than 10 m (Domotor and McLean 1988). A detailed description of the Calvert Cliffs area can be found in the Final Environmental Statement I

Related to the Operation of Calvert Cliffs Nuclear Power Plant, Units 1 and 2 (USAEC 1973) and in Baltimore Gas and Electric's license renewal application (BGE 1998). I The Calvert Cliffs region of Chesapeake Bay supports an abundant and diverse macrobenthic assemblage (Ranasinghe et al. 1996) and populations of commercially 1-2

Introduction important finfish and shellfish (Lippson and Lippson 1997). Oysters are present near CCNPP and are commercially harvested from the area. Blue crabs are also abundant throughout the site and are harvested both commercially and recreationally. This area of Chesapeake Bay also supports a diverse finfish community, including forage species (e.g.,

menhaden, anchovies, and silversides) and commercially important predatory species (e.g.,

weakfish, striped bass, and bluefish).

1.2.2 Peach Bottom Atomic Power Station Exelon Generation Company, a subsidiary of Exelon Corporation, operates PBAPS, which began operations in 1974. The plant is jointly owned by Exelon Generation and Public Service Electric and Gas of New Jersey. The plant is located in York County, Pennsylvania, approximately 5 km north of the Pennsylvania-Maryland border, on the western shore of Conowingo Pond. Each of PBAPS's two units is a boiling water reactor (BWR) with a capacity of 1098 megawatts. Controlled releases of radionuclides are permitted at levels defined in PBAPS's license (issued October 25, 1973 for Unit 2 and July 2, 1974 for Unit 3) from the United States Nuclear Regulatory Commission (10 CFR Part 20, Appendix B; USNRC 1991). Exelon Generation Company applied for a 20-year extension of its operating license on July 2, 2001 (Exelon Nuclear 2001) and received USNRC approval on May 7, 2003. The current licenses for Unit 2 and Unit 3 will expire in 2033 and 2034, respectively (Exelon Nuclear 2003).

PBAPS withdraws cooling water from the portion of Susquehanna River known as Conowingo Pond at an average rate of about 625,000 gal/min (PBAPS Communications Office 1997). Conowingo Pond also receives radionuclides in aqueous discharges from the plant during normal operations. Conowingo Pond is an impoundment created by Conowingo hydroelectric dam (13 km downstream from PBAPS) and Holtwood Dam (10 krn upstream of PBAPS). It has an average surface area of approximately 3700 ha (14 mi 2) and ranges in depth from about 3 m in upriver sections to a maximum of about 27 m at the face of Conowingo Dam. The annual average river flow at the dam is approximately 1000 m 3/s (35,000 ft 3/s; James et al. 1996). Downriver flow may be perturbed by withdrawal and discharge of cooling water for PBAPS; periodic cycling of water at the Muddy Run Pumped Storage Facility on the eastern shore, north of the plant; and operation of the turbines at Conowingo Dam.

The Susquehanna River enters the tidal portion of Chesapeake Bay approximately 6 krn downstream from Conowingo Dam. The location of the resulting interface between fresh and salt water fluctuates at the river mouth (Susquehanna Flats) or upper Chesapeake Bay and is controlled principally by river volume. The transition from fresh to brackish water is accompanied by changes in physical and chemical factors that affect the degree to which metals and radionuclides become or remain associated with particles suspended in the water column (Olsen et al. 1989). These factors influence the dispersion and distribution of radionuclides in the Susquehanna-Chesapeake Bay system.

The Susquehanna-Chesapeake Bay system supports an abundant and diverse macrobenthic assemblage as well as populations of recreationally and commercially 1-3

I Introduction important finfish (Martin Marietta 1985). Conowingo Pond contains largemouth and smallmouth bass, walleye, sunfish, channel catfish, carp, and hybrids of white and striped bass, which are principal components of the recreational fishery below Conowingo Dam.

Further downstream, white perch, channel catfish, blueback herring, American shad, and American eels are commercially fished on Susquehanna Flats. The Susquehanna Flats area supports seasonal stands of submerged aquatic vegetation (SAV), primarily Eurasian milfoil (Myriophyllum spictum), and is an important early wintering ground for migratory waterfowl (Lippson 1973).

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Methods and Materials 2.0 METHODS AND MATERIALS 2.1 SAMPLE COLLECTION Tables 2-1 and 2-2 list the environmental samples collected from Chesapeake Bay, Conowingo Pond, and Susquehanna Flats for radiological analysis. Figures 2-1 and 2-2 present the Chesapeake Bay and Susquehanna River study areas and sampling sites for monitoring releases from CCNPP and PBAPS. In the CCNPP study area, both "plant site" and "nearfield" refer to the sampling area in the immediate vicinity of CCNPP. "Kenwood Beach" and "farfield" refer to the sampling area 12 km north of CCNPP.

Table 2-1. Environmental samples for radiological analysis collected in 2004-2005 from Chesapeake Bay in the vicinity of CCNPP.

Sample Collection Number of Description of Media Frequency Sampling LocationsJ Sampling Locations Sediments Spring 28 Chesapeake Bay in the vicinity of Summer 28 CCNPP along 8 transects Fall 28 Winter 28 Oysters Quarterly 2 Plant site and Kenwood Beach Semi-annually 2 Tri-quarterly 2 Annually 2 Table 2-2. Environmental samples for radiological analysis collected in 2004-2005 from lower Susquehanna River and upper Chesapeake Bay.

Sample Collection Number of Description of Media Frequency Sampling LocationsJ Sampling Locations Sediments Spring and Fall 19 Conowingo Pond (12 stations);

Susquehanna Flats (6 stations); upper Chesapeake Bay (1 station)

Forage finfish Spring and Fall 1 Conowingo Pond (on the western shore downstream of the PBAPS discharge at station LYH-1)*

Edible finfish Spring and Fall 1 Conowingo Pond (LYH-1)*

SAV Spring and Fall 3 Susquehanna River (on the shores below the Rt. 95 bridge), Susquehanna Flats (near fishing battery), and Conowingo Pond (LYH-1)*

• LYH = Little Yellow House, see Figure 2-2.

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Methods and Materials Figure 2-1. Transects and stations for samples collected from Chesapeake Bay. Appendix A contains a list of coordinates for all stations.

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Methods and Materials Figure 2-2. Transects and stations for samples collected from lower Susquehanna River and upper Chesapeake Bay. Appendix A contains a list of coordinates for all stations.

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I Methods and Materials 2.1.1 Sediments I Sediments were collected periodically from the series of transects shown in Figure 2-1 and Figure 2-2. A hydraulic box-grab was used to collect sediments in the vicinity of CCNPP (quarterly), whereas a hand-operated Young grab was used to collect sediments at I stations surrounding PBAPS (semi-annually). The top 10 cm (or less) of sediment were recovered from each grab, and grabs were repeated until approximately 3000 cc of sediment were collected at each station.

2.1.2 Biota' For the tray-oyster study at CCNPP, mature oysters were placed into partitioned trays (Abbe 1981) and submerged for a variety of exposure periods. Trays were placed 0.4 km north of the CCNPP cooling-water outfall and were supported by a platform resting approximately 0.5 m from the bottom (approximately 5 to 5.5 m from the surface). Each tray had four compartments designed to hold 50 oysters each. Oysters from individual compartments (50 per group) were retrieved and restocked on a schedule designed to I

evaluate radionuclide concentrations in oysters exposed to CCNPP discharges for 3, 6, 9, and 12 months.

Biota for radiological analysis collected from the PBAPS study site included forage finfish, recreationally and commercially important finfish, and SAV. Edible and forage finfish were collected by electrofishing or by gill net (1-, 2-, and 4-inch experimental I

mesh). Samples of SAV were collected by hand.

2.2 MEASUREMENT OF GAMMA-EMITTING RADIONUCLIDES IN BIOTA AND SEDIMENTS 2.2.1 Sample Preparation Sediment samples were placed in a 2-liter Marinelli beaker and analyzed for radionuclide content using gamma spectrometry. After being counted, dried, and weighed, sediment samples were analyzed for particle size (Section 2.3) to determine their composition (e.g., sand, silt, or clay).

I Some forage finfish (e.g., shiners and silversides) and juveniles of other species (e.g., sunfish and gizzard shad) are important food sources for predatory finfish (e.g.,

smallmouth bass, largemouth bass, and striped bass) that are consumed by humans.

These forage fish were analyzed whole (i.e., viscera and bone were not removed) to detect radioactivity that could be transferred through the food chain and potentially contribute to I

a radiation dose to humans. Edible finfish were filleted, and samples of flesh and gut were analyzed for gamma-emitting radionuclides.

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Methods and Materials Biological samples were prepared for analysis as follows:

Oyster flesh: Samples were homogenized in a blender, diluted to 1 or 2 liters with deionized water, and preserved in a 10% solution of formaldehyde.

Edible finfish flesh and forage finfish: Samples were diced into 3-cm cubes, packed to a volume of 1 or 2 liters, and preserved in a 10% formaldehyde solution.

Edible finfish gut: Samples were wet-digested in nitric acid and diluted to 1 or 2 liters with deionized water.

Submerged aquatic vegetation: Samples were packed to a volume of 1 or 2 liters and preserved in a 10% solution of formaldehyde.

The biota samples, prepared as described above, were placed in a 1- or 2-liter Marinelli beaker and analyzed for radionuclide content using gamma spectrometry.

2.2.2 Gamma Spectrometry The gamma-ray counting system consisted of two high-resolution, intrinsic germanium detectors, one manufactured by Ortec (Ortec, Inc., Oak Ridge, TN) and the other by Canberra (Canberra, Inc., Meriden, CT). The detectors were 25% and 23%

efficient (relative to Nal), respectively, and were coupled to a Canberra Genie-2000 spectrum acquisition and analysis system (Stanek et al. 1 996a).

Electronic files containing appropriate nuclide library data and counting efficiency curves by sample were used to produce reports of the concentrations of radionuclides in the samples. Gamma-ray energy and intensity values used in energy-to-channel calibration and in data reduction were based on library data incorporated into the Genie-2000 software, which were referenced to the National Nuclear Data Center of the Brookhaven National Laboratory (Stanek et al. 1996b).

Counting efficiency curves were determined using custom multi-gamma standards commercially purchased from Analytics, Inc., Atlanta, GA, which were traceable to NIST.

All spectra were acquired for 1000 minutes. Radionuclide concentrations were corrected to collection date and time. Spectra for all samples were stored electronically for future reference.

Radionuclide concentrations and pertinent sample-collection information and analysis parameters were entered into a SAS (Statistical Analysis System, Cary, NC.)

computer database according to established procedures (Frithsen et al. 1996). SAS software was used to analyze and interpret radiological data and to generate reports.

2-5

I Methods and Materials 2.3 DETERMINATION OF SEDIMENT CHARACTERISTICS The- size of sediment particles was measured to provide a basis for comparing radionuclide concentrations detected in sediments of different composition (i.e., sand versus clay). Sediment particle size analysis accounts for composition changes that may affect measured radionuclide concentrations at a collection site. Sediments were classified as silt-clay if the mean grain size was less than 63 Ipm (Wentworth scale as published in Buchanan and Kain 1971). Sediments were classified as sand if the mean grain size was greater than 63 pIm. Mean grain size was determined by wet- or dry-sieving 50-g (dry I

weight) aliquots through 250-1pm, 1 25-p.m, and 63-pLm mesh. Each fraction was dried and weighed. That portion that passed through the 63-p[m screen was determined by subtraction from the original 50g. Particle-size index values were calculated for each I

sample by multiplying the fraction of the total weight retained on the 250-pIm mesh by 4, the fraction retained on 1 25-pLm mesh by 5, the fraction retained on the 63-pIm mesh by 6, and the fraction that passed through the 63-pLm screen by 7. The sum of these products is I

the relative particle-size index for the sediment sample and ranges from the coarsest (400),

in which all material was retained on the 250-ptm screen, to the finest (700) in which all material passed through the 63-pLm screen.

I I

2.4 DATA ANALYSIS Raw analytical results were calculated using gamma spectrum analysis software i Photopeaks distinguished from background were matched to radionuclide species and quantified based on factors such as instrument conditions, volume of sample, and radioactive decay. The concentration of a radionuclide of interest was reported as a value with a 2o uncertainty.

I The lower limit of detection (LLD) was calculated for radionuclides of interest that I were not detected. The equation given in Table 2-3 defines the LLD for data included in this report. Common LLD quantities produced by sample analyses are given in Table 2-4.

LLD quantities were disregarded when summarizing yearly averages of activity values.

2.5 DETERMINATION OF POWER PLANT CESIUM-137 Cesium-137 is a constituent of both fallout from historic weapons tests and aqueous effluent from nuclear power plants. The increment of "3 7Cs that is attributable to power plants was estimated by determining the activity of Cesium-134 in the I

environmental samples. Cesium-134 is chemically identical to 13 7Cs, and both are released in a generally consistent ratio over time. Following a correction for decay of 134Cs since the time of release, the 134 Cs activity was multiplied by the release ratio of 137Cs to 134Cs in I

aqueous effluent to estimate the concentration of 137Cs from power plants in a sample. If 134CS was not present in the sample, then the entire concentration of 1 3 7 Cs was assumed i

to be the result of fallout from weapons tests. The LLD of 137Cs from power plants is higher than the LLD of 13 7Cs from fallout because its concentration is dependent on the detection of 1 3 4 Cs, which has a higher LLD due to its shorter half-life. The concentration i 2-6

Methods and Materials 137 Cs from power plants is likely to be under-estimated because of the high probability of false-negatives in this analysis.

Table 2-3. Determination of the lower limit of detection. Source: Canberra 1998.

Lower limit of detection is given by:

LLD- LD VEBTKw where V = The mass or volume of sample E = The counting efficiency for the peak of interest B = The branching ratio of the gamma ray peak T = The sample counting time (live) in seconds Kw = The decay correction factor In(2)t.

Kwv = e T,/2 T1/2 = The half life of the nuclide tw = The elapsed clock time from the time the sample was taken to the beginning of the measurement LD = The uncertainty in the continuum count rate at the peak of interest L, = K 2 + 2Lc 2 + T2 Lc=KO"= K lF +PII+ UF+U Lc = Critical level, below which a net signal cannot reliably be detected a*0 = Variance of a null net signal K = 2.327 (based on a Poisson distribution at a confidence level of 99%)

lIF = The "true" calculated continuum under the peak Fi = The "true" measured background interference -- net peak area e3F = The variance of F (calculated continuum under the peak due to Compton scattering) cy = The variance of I (measured background interference -- net peak area) 2-7

I Methods and Materials I Table 2-4. Approximate lower limits (99%) of detection for selected counting I geometries (pCi/kg).

Radionuclide Energy

_(keV)*

Biota (1L)

(1 kg wet)

Biota (2L)

(2 kg wet)

Sand (21)

(3 kg dry)

Clay (2L)

(1.5 kg dry)

I 7

Be 478 58 60 Co 811 27 3

17 2

15 3

56 6 I Co 1333 4 2 3 7 65 95 Zn Nb 1116 766 7

3 6

3 8

3 19 8

I 95 103 Zr Ru 757 497 5

3 4

2 5

3 12 6 i 106Ru 622 28 21 23 55 11omAg 125_Sb 885 601 3

8 2

6 3

7 8

17 I

134Cs 137 Cs 605 662 3

3 2

2 3

2 8

5 I

144Ce 134 19 13 26 52

• keV = thousand electron-volts.

Note: A seven-day decay period between sample collection and counting is assumed.

I I

2.6 DATA PRESENTATION Appendix B contains radionuclide concentration data for samples collected in the I

vicinity of CCNPP and PBAPS in the 2004-2005 monitoring period. The radionuclides reported in these tables include the naturally occurring radionuclides, 7Be and 40K; the radionuclide from fallout, 60 1

65 37 Cs; and the radionuclides released from power plants, 5 8Co, I

Co, 11°omAg, 1311, and Zn. Separate tables are provided for sediments, oysters (Crassostrea virginica), finfish (various species), and SAV. Within each table, specific sample stations are arranged approximately north to south, and data are presented by date I

along with the yearly and overall means for the monitoring period.

Radionuclide concentration data are decay-corrected to the date of sample I collection. The counting uncertainty is reported as +/- 2a. Concentrations for radionuclides of interest that were not detected in specific samples were recorded as less than (<) the lower limit of detection for that sample. I 2-8

Results and Discussion 3.0 RESULTS AND DISCUSSION Plant discharge and monitoring data collected in 2004-2005 were used to complete assessments to identify and quantify sources of radionuclides, determine the concentration of radionuclides in environmental samples, and estimate potential radiological risks to ecological resources and humans. The results of these assessments are presented in separate sections below.

The origins of the more commonly observed radionuclides in environmental samples were identified to assess the magnitude of the contribution of 'radionuclides from power plants relative to those from fallout and natural source. The quantities of individual radionuclides released from CCNPP and PBAPS during 2004-2005 are provided to compare to quantities observed in environmental samples collected during the same period. Curie and millicurie levels of environmentally significant radionuclides discharged from power plants into the aqueous pathway generally translate into nanocurie and picocurie quantities of plant-related radionuclides in the environmental samples collected for this monitoring program.

3.1 SOURCES OF RADIONUCLIDES Nature, past atmospheric tests of nuclear weapons, and discharges from nuclear power plants are the three primary sources of radioactive material in Chesapeake Bay and Susquehanna River. Radionuclides attributable to each of these sources were detected in samples of biota and sediment collected in 2004-2005.

3.1.1 Radionuclides from CCNPP and PBAPS 3.1.1.1 Summary Radionuclide releases from nuclear power plants generally fall into three classes:

noble gases, tritium, and iodines and particulates. The quantities and proportions of these three classes of radionuclides released into the atmosphere and into waterways vary based on plant design (Figure 3-1, Figure 3-2, and Table 3-1). PBAPS uses boiling water reactors, whereas CCNPP uses pressurized water reactors.

In the 2004-2005 monitoring period, most radioactive effluent from CCNPP was in the form of tritium released to the aqueous pathway (88%), whereas most radioactive effluent from PBAPS was in the form of noble gases released to the atmosphere (97%;

Figure 3-3).

Noble gases are chemically inert, are not readily incorporated into biological tissues, and are not bioconcentrated. They are dispersed in the environment and generally have short half-lives, decaying rapidly to stable forms. Tritium is also readily dispersed in the environment and reduced rapidly to background levels.

3-1

I Results and Discussion I CCNPP Total Releases I

I I

I Tritium 87.15%

I Noble Gases 12.35%

I Env. Signif.

0.50% I I

CCNPP Environmentally Significant Releases I

Fe-55 69.94% I I

I i

I I

Figure 3-1. Relative contributions of noble gases, tritium, and environmentally significant radionuclides released from CCNPP, 2004-2005. Noble gases include atmospheric and dissolved gases.

I 3-2 i

Results and Discussion PBAPS Total Releases Noble Gases 97.48%

Tritium 2.50%

Env. Sig 0.01%

PBAPS Environmentally Significant Releases Fe-55 Mn-54 14.88% 10.90%

1-131 10.18%

z

/ Cr-51 Co-60 6.99%

28.17% 1-135 Other /

2.56%

Co-58

\ Zn-65 Fe-59 / nao/o 3.44%

0.81%

Figure 3-2. Relative contributions of noble gases, tritium, and environmentally significant radionuclides released from PBAPS, 2004-2005. Noble gases include atmospheric and dissolved gases.

3-3

Results and Discussion I Table 3-1. Annual releases (curies) from all pathways of noble gases, tritium, iodines I and particulates from CCNPP and PBAPS, 2004-2005. Source: Constellation Energy 2005, 2006 and Exelon 2005, 2006.

CCNPP PBAPS I

j Type lodines and Particulates air 0.0077 liq.

0.14 total 0.15 air 0.087 liq.

0.18 total 0.27 I

Tritium 12.35 2,451.00 2,463.35 0.00 45.62 45.62 Noble Gases 348.66 0.49 349.15 1,775.71 0.0016 1,775.71 I Total 361.01 2,451.63 2,812.64 1,775.80 45.80 1,821.60 I

SCCNPP PBAPS:

C I 2500 I 2000 I

E 1500-U) 1000 I

500 I

0 Noble Gases Tritium Env. Sig I

I Figure 3-3. Releases of noble gases, tritium, and environmentally significant radionuclides from CCNPP and PBAPS, 2004-2005. Noble gases include atmospheric and dissolved gases. Environmentally significant radionuclides include iodines and I

particulates.

3-4

Results and Discussion Certain radioiodines and radioactive particulates (which are composed of metal isotopes) are considered environmentally significant. Environmentally significant radio-nuclides are those that have a strong tendency to adsorb onto particles, can accumulate in biological tissues, and can be concentrated through trophic transfer (Section 3.1.1.2).

Releases of environmentally significant radionuclides into the aqueous pathway from both CCNPP and PBAPS were very low. CCNPP and PBAPS released 0.81 mCi and 1.0 mCi of 137Cs, respectively. CCNPP and PBAPS released 2.4 mCi and 76 mCi of 6°Co, respectively (Figures 3-4 through 3-7). All releases of radionuclides from PBAPS and CCNPP were the result of normal plant operation and maintenance procedures and were within regulatory limits established by,he USNRC and USEPA. Quantities of releases from CCNPP and PBAPS were obtained from Conrstellation Energy Group's and Exelon Nuclear's semi-annual reports to the USNRC, respectively (Constellation Energy Group 2005, 2006; Exelon Nuclear 2005, 2006).

3.1.1.2 Radionuclides of Interest In 2004-2005, CCNPP released approximately 138 mCi (0.0049% of total) of environmentally significant radionuclides to Chesapeake Bay; PBAPS released approximately 182 mCi (0.010% of total) of environmentally significant radionuclides to Susquehanna River during the same period. Releases of environmentally significant radionuclides (Table 3-2) vary annually due to changes in power plant maintenance, operating conditions, and waste filtration technology (Conatser 2005).

Table 3-2. Total environmentally significant releases (mCi) from CCNPP and PBAPS to the aqueous pathway, 1996-2005.

CCNPP PBAPS 1996-1997 1028 13 1998-1999 958 25 2000-2001 990 57 2002-2003 342 324 2004-2005 138 182 3-5

Results and Discussion I I

CCNPP IUMCs-1 37 I 251 20-1 7:! I E

O0 15 I

4) 10 I

ZO cc-54 1996 1997 1998 1999 2000 2001 Year 2002 2003 2004 2005 I I

Figure 3-4. Annual aqueous releases of 13 7Cs from CCNPP, 1996-2005. Sources: BGE 1997-2000; Constellation Energy 2001-2006.

I PBAPS I

• Cs-137, 1.6 1.4 I

1.2 1,

I E

"a cc:

0.8 0.6 I

I 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year Figure 3-5. Annual aqueous releases of 137 Cs from PBAPS, 1996-2005. Sources: PECO 1997-2000; Exelon 2001-2006.

3-6

Results and Discussion cc NPP E

0)

Cu a) a)

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year Figure 3-6. Annual aqueous releases of 60Co from CCNPP, 1996-2005. Sources: BGE 1997-2000; Constellation Energy 2001-2006.

PBAPS 120 03 Co-601 100-Z 80 w 60FZ I 40 60 1996 1997 1998 1999 '2000' 2001 2002* 2003 '2004 '2005 Year Figure 3-7. Annual aqueous releases of 6°Co from PBAPS, 1996-2005. Sources: PECO 1997-2000; Exelon 2001-2006.

3-7

Results and Discussion I At CCNPP, liquid radioactive wastes are discharged through the cooling-water outfall approximately 0.3 km offshore and are diluted in the receiving water. At PBAPS, I

the cooling-water outfall is located at the extreme downstream end of the power plant site, along the western shore (near Station LYH-1). I Gaseous radioactive effluent is captured and stored on site until it has decayed to lower levels. Air monitoring in the vicinity of PBAPS indicates that the effluent is diluted and dispersed to less than detectable levels in the environment (CEIR 2008); therefore, I

radioiodines and particulates released to the atmosphere are not considered environmentally significant. I Table 3-3 lists the q~uantities of the principal environmentally significant radionuclides released via the aqueous pathway in 2004-2005. Table 3-3 also identifies which of these radionuclides were found in sediment samples (Section 3.2).

I I

Table 3-3. Quantities of environmentally significant radionuclides released from CCNPP and PBAPS via the aqueous pathway during 2004-2005. Sources:

Constellation Energy 2005, 2006; Exelon 2005, 2006. I Radionuclide Quantity Released (Ci) Detected in Sediment lo°mAg CCNPP 0.00027 PBAPS 0.00049 CCNPP no PBAPS no I

58 Co 60 51 Co 0.00829 0.00236 0.00263 0.07517 no no no yes I Cr 0.00108 0.0188 no no 134 Cs l 37 Cs*

0.00035 0.00081 0.00016 0.00092 no no no no I 55 Fe 0.1018 0.04004 no no 59 Fe 1311 0.000022 0.00045 0.00218 0.00118 no no yes no I

54 Mn 95 Nb 0.00022 0.00047 0.02933 0.00019 yes no yes no I 12 5 mTe 0.0127 0 no no 65 95 Zn Zr 0.00028 0 0.00895 0.00011 no no no no I

other 0.00915 0.00168 no no Note: * = also present in environment as fallout product (see Section 3.1.3) I 3.1.2 Natural Radionuclides I Naturally occurring radionuclides are present everywhere in the environment. The principal naturally occurring radionuclides that result in measurable radiological doses to I 3-8

Results and Discussion 40 232 235 238 human populations include K and those radionuclides in the Th, U, and U decay series. Potassium-40 was detected in all samples; specific gamma-emitting daughter radionuclides from the uranium and thorium decay series were detected less frequently.

Interactions between cosmic rays and oxygen and nitrogen in the atmosphere produce several radionuclides (Whicker and Schultz 1982). One of these, 7Be, was detected frequently in sediments from both CCNPP and PBAPS and in SAV from PBAPS; however, the natural production of 7Be (half-life = 53 days) in the atmosphere contributes only a small portion of the total radiation dose from natural background.

3.1.3 Radionuclides from Weapons Tests Atmospheric tests of nuclear weapons conducted until 1980 have introduced a variety of manmade radionuclides into the environment. Cesium-137 was the only radionuclide attributable to weapons testing detected during the monitoring period. Due to its very long half-life (approx. 30 years), 137Cs has persisted in the environment long after other testing-related radionuclides have decayed to stable states.

3.2 RADIONUCLIDES IN ENVIRONMENTAL SAMPLES The environmentally significant radionuclides detected in samples from the study area consisted principally of 6°Co, 137 Cs, and 1311 (SAV only). This has been the trend since the early 1 990s, when reductions in radionuclide releases from both power plants resulted in a parallel decline in detection frequency and concentrations of plant-related radionuclides. The reductions in release rates are due, in part, to improved ion-exchange technologies at the cooling water intake and more efficient use of existing methods for reducing radioactive waste.

3.2.1 Sediments Sediments serve as sinks for both stable and radioactive metals. Suspended particulate material can scavenge metals through flocculation and adsorption, or the surface layer of bottom sediments may adsorb metals directly from the water column (Santschi et al. 1983). Because of these processes, sediments can accumulate metal radionuclides over time. Measurements of spatial and temporal patterns in the concentrations of radionuclides in sediments collected from Chesapeake Bay and Susquehanna River have been used to track the physical transport of radionuclides and intra-annual variability in the release of radionuclides from the two nuclear power plants since 1975. PPRP's monitoring results for sediment collected during 2004-2005 are summarized below. Appendix B presents concentrations of selected environmentally significant radionuclides detected in all of the sediment samples collected during 2004-2005.

3-9

I Results and Discussion I A variety of factors influence the concentrations of radionuclides in sediments, including rate of input; geographic location in relation to the power plant (e.g., distance, if I

applicable); half-life of the radionuclide; natural processes such as sedimentation, circulation, and bioturbation; and physical factors such as depth of the sediment layer from the water surface and sediment grain size. Sediment grain size was the only factor I

specifically analyzed for this report. Sediments collected at inshore stations of Chesapeake Bay and at Susquehanna Flats were composed predominantly of sand (particle size index values between 400 and 500). Sediments from Conowingo Pond and offshore stations of I

Chesapeake Bay, which were collected from depths greater than 8 m, were mostly clay (particle size index values between 600 and 700). Figures 3-8 and 3-9 show mean particle size values for sediments collected from Chesapeake Bay and Susquehanna River in 2004-I 2005. A detailed statistical exploration of physical factors that can determine spatial and temporal variability in measured radionuclide concentrations in sediment can be found in Whalen and Jones 2000.

I Radionuclides of natural origin (7 Be, 40K, Th and U decay series), from weapons tests ( 137 Cs), and from power plants (6°Co) were generally detected at higher I

concentrations in clay sediments than in sand sediments during 2004-2005. Metal radionuclides have a greater affinity for clay than for sand, due to the fine crystalline structure, greater surface area, and the higher cation exchange capacity of clay particles I

(Eisenbud 1987). Sandy sediments are coarser and less able to adsorb radionuclides (Olsen et al. 1989). I I

1 2

I (U

3 4 I

.2 t~

M I

CL S LFP LCCRL I

WS FP CCO RP LNG Transect CP LCP DP I

I Figure 3-8. Mean particle size values for sediments collected from the vicinity of CCNPP, 2004-2005. Horizontal axis arranged from North to South. I 3-10 I

Results and Discussion PBAPS 0 Station 1 E Station 2

• Station 3 700 1:

600-N)

A?500tmm ii.. III LYH COC SR3 SF6 SF8 UB10 Transect Figure 3-9. Mean particle size values for sediments collected from the vicinity of PBAPS, 2004-2005. Horizontal axis arranged from north to south.

3.2.1.1 Radionuclides from CCNPP and PBAPS in Sediment Most of the environmentally significant radionuclides found in sediment in both study areas was 137Cs from weapons tests and 6"Co from power plants. Manganese-54 was found in three samples from downstream of PBAPS in Conowingo Pond and in one sediment sample down-Bay of CCNPP. Iron-59 was detected once in the PBAPS study area, and 141Ce was detected twice near CCNPP. Cesium-137 was found in most sediment samples and is discussed in Section 3.2.1.3. All 137Cs detected during this monitoring period is assumed to be from fallout because no 134Cs was detected in samples collected during the period.

Cobalt-60 was notably absent from all CCNPP-related sediment samples for the first time since long-term monitoring began more than 30 years ago (Table 3-4). It was detected in 18.4% of sediment samples collected from the vicinity of PBAPS, which represents a slight increase over the 2002-2003 monitoring period. The recent increase in 60 Co detection rates at PBAPS generally reflects increased aqueous discharges of 6"Co from PBAPS during 2001-2005 (265 mCi) in contrast to 1996-2000 (16 mCi). At PBAPS, maximum 60Co concentrations were observed at Station LYH-1 (the station located closest to the outfall); lesser amounts were detected at downstream deposits near the western shore of Conowingo Pond (Figure 3-10). No 60Co was detected at distant stations below the dam, where sediments have a greater proportion of coarse particles.

3-11

I Results and Discussion I Table 3-4. Percent detection frequency of 60Co in CCNPP and PBAPS sediments, 1996- I 2005.

Monitoring Period 1996-1997 CCNPP 25 PBAPS 5

I 1998-1999 12.5 2.6 2000-2001 2002-2003 6.3 3.6 6.6 15.8 I

2004-2005 0 18.4 I

I SPBAPS I

250"

_ 200 I

150-Z 100 I

I LYH BC COC DAM SR3 SF1 Transect SF6 SF7 SF8 SF9 UB10 I

Figure 3-10. Geographical distribution of average activity of 60Co near PBAPS, 2004-I 2005. Horizontal axis arranged from North to South.

I 3.2.1.2 Natural Radionuclides in Sediment Generally, the major components of sediment radioactivity were the naturally I

occurring radionuclides of the thorium and uranium decay chains, 40K, and 7Be. Naturally occurring radionuclides were responsible for more than 99% of the gamma-emitting radionuclides found in most sediment samples (Figure 3-1 1 and Figure 3-1 2).

I Thorium and Uranium. Nuclear decay of naturally occurring thorium (232Th) and natural uranium ( 238U) produces gamma-emitting daughter species (e.g., thorium: 228Ac, 208 2 12 I

TI, Pb; uranium: 2 26 2 14 2 14 Ra, Bi, Pb) that accounted for most radionuclides present in sediments. The highest concentrations of these daughter radionuclides were observed at offshore stations with fine-grained sediment.

I 3-12

Results and Discussion CCNPP U-235 chain 2.8%

U-238 chain 27.0%

K-40

• 50.3%

I Th-232 chain Cs-1 37 19.6% 0.4%

Figure 3-11. Proportion of gamma-emitting radionuclides in sediment samples. Example data from the Cove Point transect, station 2.

PBAPS U-235 chain U-238 chain 0.5%

26.4%

K-40 49.9%

Th-232 chainX 22.9%

/

Cs-1 37 0.3%

Figure 3-12. Proportion of gamma-emitting radionuclides in sediment samples. Example data from the Little Yellow House transect, station 1.

3-13

I Results and Discussion Potassium-40 is a primordial, naturally occurring radionuclide that was present in 100% of sediment samples collected during the monitoring period. Potassium-40 concentrations in nature are proportional to stable potassium content (0.0118%; CRC 1979). Potassium-40 concentrations were highest in predominantly fine-grained sediments.

Beryllium-7 is a natural radionuclide produced by the interaction of cosmic rays with atmospheric oxygen and nitrogen. It is deposited on water and soil surfaces through precipitation scavenging and may enter water systems through runoff from land. Particles suspended in the water column adsorb it rapidly, and it appears in sediments as a result of particulate deposition.- Beryllium-7 was detected in 63% and 19% of sediment samples collected at PBAPS and CCNPP, respectively. Concentrations of 7Be were generally less at CCNPP than at PBAPS. Beryllium-7 concentrations near PBAPS were generally higher in samples with greater proportions of clay particles, particularly those collected from stations in Conowingo Pond near Conowingo Dam (Conowingo Creek and Conowingo Dam transects). Concentrations at sampling stations below Conowingo Dam tended to be lower due to the dominance of sandy sediment, except in clayey sediments at SF-9 and UB-10 stations. Concentrations of 7 Be at CCNPP were generally highest (when detected) in near-shore sediments where most particles were silt-sized (e.g., Cove Point 1 and Cove Point 2 stations. Beryllium-7 was rarely detected at off-shore stations with clay sediments. This contrast with results for clay sediments from the PBAPS study area may be due to high settlement time at the off-shore stations in relation to half-life.

3.2.1.3 Radionuclides from Weapons Tests in Sediment The presence of 137 Cs in sediments is assumed to be from the fallout from atmospheric atomic weapons testing, which ended approximately three decades ago.

Cesium-137 continued to be present in nearly all (91.1% at CCNPP, 96.1% at PBAPS) sediment samples from Chesapeake Bay and Susquehanna River. Because new weapons inputs to the local ecosystem continue to be nil, 137 Cs is likely to be the only fallout-related, gamma ray-emitting radionuclide to be considered in the future.

Concentrations of 137Cs were less in sediments composed primarily of sand than in those composed primarily of clay. The concentrations of 137Cs in sediments collected near PBAPS and CCNPP generally have decreased gradually since 1981 due to reductions in discharges, decay of the inventory of 137Cs present in the sediment, and dilution by sedimentation (Figures 3-13 and 3-14). At representative transects (e.g., Flag Ponds at CCNPP and Broad Creek at PBAPS), average 13 7Cs concentrations have decreased, in most cases, by more than 50% since the initiation of the monitoring program. Concentrations at Broad Creek have decreased by at least 75% over the past 24 years, demonstrating the effect of sedimentation for reducing 137Cs concentrations and its apparent half-life (Table 3-5). The greater rate of decrease of 137Cs concentrations over time in Conowingo Pond reflects the greater sedimentation rate compared to Chesapeake Bay.

I 3-14

Results and Discussion cCNPP]

1400

-FP-1 (pCi/kg) 1200 - --- FP-2 (pCi/kg)

- -...... FP-3 (pCilkg) 1000

-Cs-137 release (mCi) 4-4-

800 0n 600 400 200 .....................

1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 Year Figure 3-13. Total annual release of 137 Cs from CCNPP and average annual activity of 37 1 Cs in CCNPP sediments, Flag Ponds transect, 1983-2005.

PBAPS 1000 800 4-600 4-0 400 200 0 -. -

1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 Year 137 1 37 Figure 3-14. Total annual release of Cs from PBAPS and average annual activity of Cs in PBAPS sediments, Broad Creek transect, 1983-2005.

3-15

I Results and Discussion I Table 3-5. Comparison of 137Cs released from CCNPP and PBAPS and sediment activities I at representative transects, 1981 and 2005.

137Cs 1981 -2005  % Reduction I CCNPP release (mCi) 103 0.0807 99.9 Flag Ponds 1 (pCi/kg) 7 1.59 77.3 I Flag Ponds 2 (pCi/kg) 98 32 67.3 Flag Ponds 3 (pCi/kg) 522 298 42.9 I Flag Ponds 4 (pCi/kg) 361 153 57.6 PBAPS 137Cs release (mCi) 170 0.441 99.7 I Broad Creek 1 (pCi/kg) 707 87 87.7 Broad Creek 2 (pCi/kg) 232 49 78.9 I

Broad Creek 3 (pCi/kg) 243 42 82.7 I

3.2.2 Biota I No radionuclides from power plants were detected in any biological samples from the 137Cs vicinity of CCNPP or PBAPS. The only radionuclide detected in finfish at PBAPS was (2%) from weapons tests. lodine-131 from medical sources was detected in samples I of Eurasian milfoil collected from Susquehanna Flats and Conowingo Pond.

The ability of biota to absorb environmentally significant radionuclides differs by I

species, habitat, availability of radionuclides, and sensitivity of biota to radionuclides. Test oysters are confined to trays in the immediate vicinity of the discharge and remain there for periods of three months to one year. Conversely, finfish in Conowingo Pond are mobile I

and reside near the PBAPS outfall for only short periods of time. Finfish tend to absorb radionuclides from fallout and PBAPS, such as ' 37 Cs, 6 0Co, and 6"Zn, whose availability via sediment has been at or near zero levels since 1989-1990.

I PPRP's monitoring results for biota collected in 2004-2005 are summarized below.

I 3.2.2.1 Radionuclides from CCNPP in Tray-oysters No IOmAg was detected in tray-oysters placed in the vicinity of the cooling water I

discharge or in continually exposed oysters at the farfield (control) location (Kenwood Beach) during the monitoring period (Figure 3-15). The inability to detect 11°mAg since spring, 2001, reflects a recent downward trend in liomAg releases from CCNPP.

I Uptake of radionuclides, particularly ilo°Ag, by tray-oysters is governed by physical, chemical, and environmental conditions (e.g., plant releases, water temperature, season of I

3-16 I

Results and Discussion exposure). A detailed discussion of the tray-oyster study and statistical modeling of radionuclide concentrations in tray-oysters can be found in McLean et al. 1 987 and Rose et al. 1988, 1989.

CCNPP Release (mCi) -------

Oysters (pCi/kg) -et 100 80" 60 O 40 20  %

0 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Year Figure 3-15. Concentration of 11°mAg in aqueous effluent from CCNPP and in 3-month tray oysters, 1994-2005.

3.2.2.2 Radionuclides from PBAPS in Finfish In 2004-2005, no radionuclides from PBAPS were detected in the samples of finfish collected from Conowingo Pond. The power plant discharges minuscule amounts of environmentally significant radionuclides; hence, very limited amounts of plant-related radionuclides are present in the sediment for potential uptake. Cobalt-60 has been detected in only one finfish sample since 1995. Fallout-related 13 7Cs was detected in one sample of walleye flesh collected from Conowingo Pond in 2005. The concentration of 137 Cs in that sample was not significantly different from concentrations in the prior several years of monitoring data; moreover, the frequency of detection in the current monitoring period was the least since the initiation of monitoring.

3.2.2.3 Radionuclides from PBAPS in Submerged Aquatic Vegetation (SAV)

Sixty-seven percent of samples of Eurasian milfoil (Myriophyllum spicatum) collected from the Susquehanna River-Chesapeake Bay system in 2004-2005 contained detectable concentrations of 1311. Releases of medical wastewater generally are regarded as the source of concentrations of 1311 found in SAV. Therapeutic doses of 1311 administered in nuclear medicine typically range as high as several hundred mCi (NCRPM 1996). PBAPS released approximately 10 mCi of 1311 during the monitoring period; consequently, PBAPS cannot be ruled out as the source of an incremental contribution of the observed concentrations of 1311.

3-17

I Results and Discussion 3.3 RADIOLOGICAL EFFECTS ON THE ENVIRONMENT AND HUMAN HEALTH n 3.3.1 Effect on the Environment Although small concentrations of radionuclides attributable to weapons test fallout were detected in biota collected in 2004-2005, the maximum detected concentrations were orders of magnitude smaller than concentrations of natural radionuclides. Radiation doses to aquatic organisms attributable to discharges from power plants are an insignificant proportion of doses derived from natural radionuclides (Whicker and Schultz 1982). Living organisms normally receive most of their external and internal doses of radiation from naturally occurring radionuclides such as 40 K. Adverse effects on sensitive aquatic vertebrates have been detected at dose rates as low as 0.4 mGy/h (40 mrad/h or approximately 350 rem in one year). Adverse effects on mollusks appear at doses of 87,660 rem in one year (Eisler 1994). Doses that cause adverse effects in these organisms are far above what ingestion of finfish from Conowingo Pond and oysters from Chesapeake Bay may deliver to humans in given monitoring years (see Section 3.3.2).

3.3.2 Effect on Human Health Potential radiation doses to human consumers of oysters and finfish were estimated based upon measured concentrations of radionuclides in edible fish. Doses were expressed as "dose commitment," which refers to the total dose to a tissue or organ during a period of 50 years following ingestion, after allowing for the metabolic processes of excretion and radioactive decay. The dose commitment calculations are based on three variables. The first variable is the maximum, or worst-case, estimated concentration of plant-related -

radionuclides in finfish collected from Conowingo Pond or oysters collected from the vicinity of CCNPP. The second variable is an estimate of the maximum quantity of finfish or oysters consumed by an individual according to age (i.e., child = 6.9 kg/yr; teen = 16 kg/yr; adult = 21 kg/yr; USNRC 1977). The third variable is the dose from the intake of a radionuclide (USNRC 1977).

Table 3-6 presents estimated dose commitments for adults, teenagers, and children based on a diet of finfish (no dose estimate based on oyster consumption is presented due to the absence of detectable concentrations of radionuclides from power plants in oyster tissue samples). The estimated maximum dose from consumption of finfish during 2004-2005 was 0.007 mrem/yr to a teenager's liver. The estimated maximum total body dose to an adult was 0.004 mrem/yr.

The promulgated maximum annual effective dose equivalent to the general population as a result of a licensee's activities involving the use of radioactive material is I 100 mrem above background levels, exclusive of the dose contribution from the licensee's disposal of radioactive material (USNRC 1991). Plant design objectives to maintain effective dose equivalent resulting from release of radioactive material as part of normal operations to levels "as low as reasonably achievable" are stated in 10 CFR Part 50 Appendix I (USNRC 1996):

3-18

Results and Discussion "The calculated annual total quantity of all radioactive material above background to be released from each light-water-cooled nuclear power reactor to unrestricted areas will not result in an estimated annual dose or dose commitment from liquid effluents for any individual in an unrestricted area from all pathways of exposure in excess of 3 millirems to the total body or 10 millirems to any organ."

Table 3-6. Estimated maximum dose commitments* in millirem per year to individuals who consume finfish from Conowingo Pond, 2004-2005. Recommended consumption values and conversion factors derived from USNRC 1977.

Age Group 2004-2005 Adult Teen Child Total Body 65 Zn 0.0000 0.0000 0.0000 134Cs 0.0000 0.0000 0.0000 13 7Cs 0.0044 0.0024 0.0009 TOTAL 0.0044 0.0024 0.0009 Bone 65 Zn 0.0000 0.0000 0.0000 134Cs 0.0000 0.0000 0.0000 137 Cs 0.0049 0.0053 0.0066 TOTAL 0.0049 0.0053 0.0066 Liver 65 Zn 0.0000 0.0000 0.0000 134 Cs 0.0000 0.0000 0.0000 137 cs 0.0067 0.0070 0.0063 TOTAL 0.0067 0.0070 0.0063 Kidney 65 Zn 0.0000 0.0000 0.0000 1 34 137 CS 0.0000 1 0.0000 1 0.0000 Cs 0.0023 0.0024 0.0021 TOTAL 0.0023 0.0024 0.0021 Gastrointestinal tract - lower large intestine 65 Zn 0.0000 0.0000 0.0000 134Cs 0.0000 0.0000 0.0000 137 Cs 0.0001 0.0001 0.0000 TOTAL 0.0001 0.0001 0.0000

• Dose commitment: kg mrem X pCi yr pCi kg 3-19

Results and Discussion The USEPA has set maximum permissible dose rules as part of the regulation of the uranium fuel cycle, which includes the mining of ore in addition to the operation of nuclear power plants (40 CFR Part 190 Subpart B; USEPA 1979):

"Operations covered by this subpart shall be conducted in such a manner as to provide reasonable assurance that: A) The annual dose equivalent does not exceed 25 millirems to the whole body, 75 millirems to the thyroid, and 25 millirems to any other organ of any member of the public as the result of exposures to planned discharges of radioactive materials, radon and its daughters excepted, to the general environment from uranium fuel cycle operations and to radiation from-these operations. B) The total quantity of radioactive materials entering the general-environment from the entire uranium fuel cycle, per gigawatt-year of electrical energy produced by the fuel cycle, contains less than 50,000 curies of krypton-85, 5 millicuries of iodine-129 and 0.5 millicuries combined of plutonium-239 and other alpha-emitting transuranic radionuclides with half-lives greater than one year."

The dose commitment estimates given above show that the quantities of radionuclides found in sediment and biota do not pose a threat to human health as measured by their consequent effective dose equivalent as they migrate through trophic layers to humans.

3-20

Conclusions

4.0 CONCLUSION

S During the 2004-2005 monitoring period, CCNPP and PBAPS released radionuclides to the environment as a normal consequence of routine operations, and all quantities released resulted in estimated doses that were much less than regulatory limits set by the USNRC. Radionuclides released from CCNPP were detected in isolated samples collected from Chesapeake Bay. In the PBAPS study area, most plant-produced radionuclides were detected in sediment samples collected upstream of Conowingo Dam, especially at the station nearest to the cooling water discharge. No finfish samples collected near the PBAPS outfall contained detectable plant-related radionuclides.

Radionuclides from nuclear power plants, nuclear weapons testing, and natural sources contributed to the total radioactivity measured in environmental samples.

Generally, radionuclides from natural sources (primarily radionuclides from the uranium and thorium decay series, 40 K, and 7Be) contributed most to the total radioactivity of environmental samples.

Concentrations of radionuclides in sediments and biota do not represent a risk to the ecological health of Chesapeake Bay or Susquehanna River. The additional increment of radioactivity and radiation dose attributable to the operation of CCNPP and PBAPS is minimal when compared with natural levels of radioactivity and the associated natural radioactive dose.

The incremental increase in the dose to humans resulting from the consumption of biota that contain plant-related radionuclides is no more than 0.001% (NCRPM 1987).

This increase is insignificant when compared to the total dose attributable to natural background and other sources, which varies according to geographic region and elevation, habitat type (i.e., construction material used in residences), personal choices (e.g.,

smoking, occupation), and routine medical procedures.

4-1

Conclusions 4-2

References

5.0 REFERENCES

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BGE (Baltimore Gas and Electric Company). 1997-2000. Annual Effluent Release Reports for Calvert Cliffs Nuclear Power Plant, January 1 - December 31, 1996-1999.

Buchanan, J.B. and J.M. Kain. 1971. Measurement of the Physical and Chemical Environment. In: Methods for the Study of Marine Benthos, 30-50. N.A. Holme and A.D. McIntyre, eds. Oxford, England: Blackwell Scientific Publications.

CEIR 1993-2008. Maryland Power Plants and the Environment: A Review of the Impacts of Power Plants and Transmission Lines on Maryland's Natural Resources.

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CEIR 1975-1991. Power Plant Cumulative Environmental Impact Report for Maryland.

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Canberra 1998. Model S500 Genie-2000 Spectroscopy System: Basic Operation, Advanced Topics, Application Options. Version 1.2. September 1998. Canberra Industries, Inc., Meriden, CT.

Conatser, R.L. (Constellation Energy Group). 2005. Personal communication, August 17, 2005.

Constellation Energy Group. 2001-2006. Annual Effluent Release Reports for Calvert Cliffs Nuclear Power Plant, January 1 - December 31, 2000-2005.

CRC (Chemical Rubber Company). 1979. CRC Handbook of Chemistry and Physics. CRC Press, Boca Raton, FL.

Domotor, S.L., and R.I. McLean. 1989. Environmental radionuclide concentrations in the vicinity of the Peach Bottom Atomic Power Station. 1985-1986. PPER-R-1 1. July 1989. Maryland Department of Natural Resources, Power Plant and Environmental Review Division, Annapolis, MD.

Domotor, S.L. and R.I. McLean. 1988. Environmental Radionuclide Concentrations in the Vicinity of the Calvert Cliffs Nuclear Power Plant: 1985-1986. PPRP-R-10.

November, 1988. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

5-1

References Domotor, S.L. and R.I. McLean. 1987. Environmental Radionuclide Concentrations in the Vicinity of the Calvert Cliffs Nuclear Power Plant: 1981-1984. PPRP-R-8. July 1987. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Eisenbud, M. 1987. Environmental Radioactivity from Natural, Industrial, and Military Sources. Third edition. Orlando, FL: Academic Press, Inc.

Eisler, R. 1994. Radiation Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review. U.S. Department of the -Interior; National Biological Service, .Washington, DC. Biological Report 26.

Exelon Nuclear Company. 2003. Press release: "NRC Approves 20-Year License Extension For Peach Bottom". May 7, 2003. Exelon Nuclear Company, Kennett Square, PA.

Exelon Nuclear Company. 2001. Press release: "Exelon Nuclear Submits License Renewal Application For Peach Bottom Atomic Power Station". July 2, 2001. Exelon Nuclear Company, Kennett Square, PA.

Exelon Nuclear Company. 2001- 2006. Annual Effluent Reports for Peach Bottom Atomic Power Station, Units 2 and 3, January 1 - December 31, 2000-2005.

Frithsen, J.B., M.A. Stanek, J. Chaillou, M. Gaughan, and R.I. McLean. 1996.

Documentation for the PPRP Radioecology Data Base: Data Formats and Data Entry l Procedures. PPRP-R-22. April 5, 1996. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

James, R.W., R.H. Simmons, and B.M. Helinsky. 1996. Water resources data Maryland and Delaware water year 1995. Volume 1. Surface-water data. U.S. Geological Survey Water-Data Report MD-DE-95-1. U.S. Geological Survey, Towson, MD.

Jones, T.S. and R.I. McLean. 2005. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 2002-2003. PPRP-R-29. December 2005. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Jones, T.S. and R.I. McLean. 2003. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 2000-2001. PPRP-R-28. June 6, 2003. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

I 5-2n

References Jones, T.S. and R.I. McLean. 2000. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 1998-1999. PPRP-R-27. December 12, 2000. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Jones, T.S. and R.I. McLean. 1998. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 1996-1997. PPRP-R-25. November 20, 1998. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Jones, T.S., J.B. Frithsen, and R.I. McLean. 1997. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 1995. PPRP-R-24. February 1997.

Maryland Department of Natural Resources; Power Plant Research Program, Annapolis, MD.

Lacy, G. and S. Zeger. 1979. Thermal Plume Studies in the vicinity of Calvert Cliffs Nuclear Power Plant, April and May 1978. Academy of Natural Sciences of Philadelphia, Philadelphia, PA.

Lippson, A.J. 1973. The Chesapeake Bay in Maryland: An Atlas of National Resources.

Johns Hopkins University Press, Baltimore, MD.

Lippson, A.J. and R.L. Lippson. 1997. Life in the Chesapeake Bay, 2nd ed. Johns Hopkins University Press, Baltimore, MD.

MDE (Maryland Department of the Environment). 2005, 2006. Annual Report of Environmental Radiation Monitoring to the NRC, January 1-December 31, 2004, 2005.

Martin Marietta Environmental Systems. 1985. The Effects of an Interim Minimum Flow from the Conowingo Dam on Fish Feeding and Benthos in the Susquehanna River, PPSP-UBLS-85-4. June, 1985. Maryland Department of Natural Resources, Power Plant Siting Program, Annapolis, MD.

McLean, R.I., and S.L. Domotor. 1988. Environmental radionuclide concentrations in the Vicinity of the Peach Bottom Atomic Power Station: 1981-1984. PPRP-R-9.

March 1988. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

McLean, R.I., and S.M. Long. 1978. Gamma-ray emitting radionuclide concentrations is selected environmental media from the vicinity of the Calvert Cliffs Nuclear Power Plant (August 1975 - May 1978). PPSP-R-3. May 1978. Maryland Power Plant Siting Program, Annapolis, MD.

5-3

I References McLean, R.I., T.E. Magette, and S.G. Zobel. 1983. Environmental radionuclide concentrations in the vicinity of the Peach Bottom Atomic Power Station: 1979-1980. PPSP-R-5. January 1983. Maryland Power Plant Siting Program, Annapolis, MD.

McLean, R.I., T.E. Magette, and S.G. Zobel. 1982. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant: 1978-1980.

PPSP-R-4. December 1982. Maryland Power Plant Siting Program, Annapolis, MD.

McLean, R.l., J.K. Summers, K.A. Rose, and S.L. Domotor. 1987,.. Silver-i 1Om, . 8Co, and 6 5Zn Concentrations in the American oyster, Crassostreavirginica (Gmelin), Near the Calvert Cliffs Nuclear Power Plant. PPRP-R-7. December, 1987. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

NCRPM (National Council on Radiation Protection and Measurements). 1996. Sources and Magnitude of Occupational and Public Exposure from Nuclear Medicine Procedures.

NCRPM, Bethesda, MD.

NCRPM (National Council on Radiation Protection and Measurements). 1987. Ionizing I Radiation Exposure of the Population of the United States. NCRPM, Bethesda, MD.

Olsen, C.R., I.L. Larsen, FI.D. Lowry, R.I. McLean, and S.L. Domotor. 1989. Radionuclide I Distributions and Sorption Behavior in the Susquehanna-Chesapeake Bay System.

PPRP-R-12. January, 1989. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

PBAPS (Peach Bottom Atomic Power Station), Communications Office. 1997. Personal communication, February 12, 1997.

PECO (Philadelphia Electric Company). 1997-2000. Semi-annual Effluent Reports for Peach Bottom Atomic Power Station, Units 2 and 3, January 1 - December 31, 1996-1999.

Ranasinghe, J.A., L.C. Scott, and S.B. Weisberg. 1996. Chesapeake Bay Water Quality Monitoring Program Long Term Benthic Monitoring and Assessment Component:

Level 1 Comprehensive Report, July 1984 - December 1995. Versar, Inc.,

Columbia, MD.

Rose, K.A., R.I. McLean, and J.K. Summers. 1989. Development and Monte Carlo Analysis of an Oyster Bioaccumulation Model Applied to Biomonitoring Data.

Ecological Modeling 45: 111-132.

5-4

References Rose, K.A., R.I. McLean, J.K. Summers, and S.L. Domotor. 1988. Radiosilver (Ag-1 1Om)

Concentrations in Chesapeake Bay Oysters Maintained Near a Nuclear Power Plant:

.... A Statistical Analysis. Journal of Environmental Monitoring and Assessment 10:

205-218.

Santschi, P.H., D.M. Adler, and M. Amdurer. 1983. The Fate of Particles and Particle-reactive Metals in Coastal Waters: Radioisotope Studies in Microcosms. In: Trace Metals in Sea Water, 331-349. C.S. Wong, E. Boyle, K.W. Bruland, J.D. Burton and E.D. Goldberg, eds. Plenum, NY.

Stanek, M.A., and R.I. McLean. 1995a. Environmental Radionuclide Concentrations in the Vicinity of the Calvert Cliffs Nuclear Power Plant: 1987-1990. PPRP-R-1 8.

December 20, 1995. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Stanek, M.A., and R.I. McLean. 1 995b. Environmental Radionuclide Concentrations in the Vicinity of the Peach Bottom Atomic Power Station: 1987-1990. PPRP-R-1 9.

December 20, 1995. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Stanek, M.A., and R.I. McLean. 1995c. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant: 1991-1994. PPRP-R-20.

February 1997. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Stanek, M.A., and R.I. McLean. 1995d. Environmental radionuclide concentrations in the vicinity of the Peach Bottom Atomic Power Station: 1991-1 994. PPRP-R-21.

February 1997. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

Stanek, M.A., T.S. Jones, and J.B. Frithsen. 1996a. Comparison of the ND9900 and Genie-PC Data Acquisition and Spectrum Processing Systems. Technical Memorandum, November 11, 1996. Prepared for the Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD, by Versar, Inc.,

Columbia, MD.

Stanek, M.A., T.S. Jones, and J.B. Frithsen. 1996b. Documentation of the PPRP Gamma Spectrometry Methods: A Guide to Data Acquisition and Spectral Processing.

PPRP-R-23. December 10, 1996. Maryland Department of Natural Resources, Power Plant Research Program, Annapolis, MD.

USAEC (United States Atomic Energy Commission). 1973. Final environmental statement related to the operation of Calvert Cliffs Nuclear Power Plant Units 1 and 2, Baltimore Gas and Electric Company. Dockets Nos. 50-317 and 50-31.

5-5

I References USEPA (United States Environmental Protection Agency). 1979. 40 CFR Part 190. U.S.

Government Printing Office, Washington, DC.

USNRC (United States Nuclear Regulatory Commission). 1996. 10 CFR Part 50, Appendix I. U.S. Government Printing Office., Washington, DC.

USNRC (United States Nuclear Regulatory Commission). 1991. 10 CFR Part 20, Appendix B. Government Printing Office, Washington. DC USNRC (United States Nuclear Regulatory Commission). 1977. Calculation *of Annual of Doses to Man From Routine Releases of Reactor Effluents for the Purpose Evaluating Compliance with 10 CFR Part 50, Appendix I. Regulatory Guide 1.109.

Washington, DC: U.S. Government Printing Office.

Whalen, K.G. and T.S. Jones. 2000. Integrative Evaluation of PPRP's Radionuclide Sampling Program and Database. PPRP-R-26. July 10, 2000. Maryland Power I Plant Research Program, Annapolis, MD.

Whicker, F.W. and V. Schultz. 1982. Radioecology: Nuclear Energy and the Environment. Vol. 1. Boca Raton, FL: CRC Press, Inc.

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I 5-6

Appendix A APPENDIX A COORDINATES OF SAMPLING STATIONS A-1

Appendix A A-2

Appendix A Transects and Stations for Sediments Collected from Chesapeake Bay in the Vicinity of Calvert Cliffs Nuclear Power Plant Station North Latitude West Longitude Western Shores WS- 1 380 29.321' 760 29.336' WS-2 380 29.460' 760 29.239' WS-3 380 29.752' 760 28.272' WS-4 380 30.975' 76° 25.897' Flag Ponds FP- 1 380 27.254' 760 26.873' FP-2 380 27.302' 760 26.820' FP-3 380 27.402' 760 26.476' FP-4 380 29.211' 760 24.790' Calvert Cliffs Outfall CCO-1 380 26.316' 760 26.412' CCO-2 380 26.455' 760 26.266' CCO-3 380 26.795' 760 25.753' CCO-4 380 28.245' 760 24.055' Rocky Point RP-1 380 25.074' 760 24.949' RP-2 380 28.356' 760 24.490' RP-3 380 25.327' 760 24.300' RP-4 380 26.068' 760 22.896' Liquid Natural Gas Terminal LNG-1 380 22.625' 760 23.083' LNG-2 380 23.652' 760 22.882' LNG-3 380 23.745' 760 22.495' LNG-4 380 23.997' 760 21.431' Cove Point CP-1 380 22.500' 760 22.859' CP-2 380 22.541' 760 22.446' CP-3 380 22.601' 760 21.934' CP-4 380 22.635' 760 20.725' Little Cove Point LCP-1 380 21.292' 760 21.490' LCP-2 380 21.368' 760 20.180' Drum Point DP-1 380 19.553' 760 22.354' DP-2 380 19.574' 760 19.757' A-3

I Appendix A I I

Susquehanna River/Upper Bay Sediment Network Station Name/Location North Latitude West Longitude I LYH-1 Little Yellow House 39044.592' 76015.120' LYH-2 LYH-3 39044.929' 39045.242' 76014.635' 76014.082' I BC-1 Broad Creek 39041.909' 76014.017' BC-2 BC-3 39042.044' 39o42.280' 76013.657' 76013.063' I

CONCK-1 Conowingo Creek 39040.690' 76012.327' CONCK-2 CONCK-3 39040.848' 39o40.997' 76012.124' 76011.996' I

CONDAM-1 Conowingo Dam 39039.475' 76010.591' CONDAM-2 CONDAM-3 39039.675' 39040.026' 76010.546' 76010.383' I

SR-3 Susquehanna River (Rt. 95 Bridge) 39034.858' 76006.127' I

SF-1 Susquehanna Flats 39032.827' 76004.467' SF-6 (River Mouth (40'))

Buoy R "14" 39031.027' 76°05.007' I

SF-7 Buoy N "12" 39030.274' 76005.216' SF-8 SF-9 Buoy N "8" Buoy N "2" 39029.215' 39028.294' 76004.955' 76003.261' I

UB-10 Buoy RB "A" 39o26.555' 76001.997' Note:

Station #1 West I

Station #2 Center of Reservoir Station #3 East I I

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A-4 I

Appendix B APPENDIX B CONCENTRATIONS OF RADIONUCLIDES IN ENVIRONMENTAL SAMPLES B-1

Appendix B B-2

Appendix B INTRODUCTION This appendix contains data for most of the radionuclides detected in the environmental samples collected in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station during the 2004-2005 monitoring period.

The radionuclides reported in these tables include the naturally occurring radionuclides 7 Be and 40 K, the weapons test fallout radionuclide 137 Cs, and the power plant produced 58 60 65 radionuclides 1OmAg, Co, Co, 1311, and Zn. Radionuclide concentrations in sediments and biological samples are reported as pCi/kg dry weight, except for finfish gut samples which are reported as pCi/kg wet weight. Data are organized in the following tables:

Page Table 1. Radionuclide concentrations in sediments (CCNPP) B-5 Table 2. Radionuclide concentrations in oysters (Crassostreavirginica) B-1 9 Table 3. Radionuclide concentrations in sediments (PBAPS) B-21 Table 4. Radionuclide concentrations in finfish B-28 Table 5. Radionuclide concentrations in submerged aquatic vegetation B-31 Within each table, specific sample stations are arranged approximately north to south and data are presented by date along with the mean for the monitoring period. Data are decay corrected to the date of sample collection. Counting error is reported as +/- 20 error.

Concentrations for radionuclides that were not detected in specific samples are recorded as less than (<) the lower level of detection for that sample as determined by spectrum analysis programs. Annual means were calculated as a simple arithmetic average of concentrations and variability was expressed as 2 standard deviation units. Lower limits of detection were excluded from mean calculations.

B-3

Appendix B B-4

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCWES010 - Calvert Cliffs Western Shores Station 1 02/24/04 < 139 983 + 62 < 11 < 3 3 + 1 05/27/04 < 75 940 _ 57 < 6 < 2 2.9 _ 0.4 08/30/04 < 107 990 _ 62 < 9 < 3 4 1 11/22/04 < 100 1055 _ 64 < 8 < 2 3.5 + 0.4 Yearly -- 992 +/- 95 .... 3 +/- 1 03/04/05 < 146 1310 +/- 70 < 11 < 4 6 + 1 05/20/05 < 78 1036 +/- 56 < 7 < 3 3.3 + 0.5 08/30/05 61 + 16 1025 + 55 < 4 < 3 3.1 + 0.5

, 12/22/05 < 50 1229 +/- 65 < 5 < 3 4 _ 1 0,

Yearly 61 +/- 16 1150 +/- 284 .... 4 +/- 2 Overall 61 +/- 16 1071 +/- 224 -- 4 +/- 1 Station CCWES020 - Calvert Cliffs Western Shores Station 2 02/24/04 < 79 1020 + 62 < 7 < 3 6 + 1 05/27/04 < 131 3224 _ 192 < 11 < 5 28 + 2 08/30/04 < 87 2188 + 130 < 7 < 3 21 + 1 11/22/04 131 _ 51 3006 _ 179 < 11 < 4 18 + 1 Yearly 131 +/- 51 2360 +/- 1997 .... 19 +/- 18 03/04/05 < 169 3453 _ 179 < 14 < 5 29 _ 2 05/20/05 66 +/- 31 2241 _ 118 < 9 < 4 12 +/- 1 08/30/05 89 +/- 34 3889 _ 200 < 7 < 5 27 _ 2 12/22/05 < 37 879 _ 47 < 4 < 2 5 + 1 Yearly 78 +/- 32 2615 +/- 2702 .... 18 +/- 23 Overall 104 +/- 75 2488 +/- 362 -- 18.5 +/- 0.3

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCWES030 - Calvert Cliffs Western Shores Station 3 02/24/04 < 527 17381 _ 1023 < 42 < 16 369 +/- 23 05/27/04 < 269 14996 _ 877 < 22 < 10 402 +/- 24 08/30/04 < 377 16091 _ 947 < 33 < 14 403 +/- 24 11/22/04 < 384 15942 _ 932 < 28 < 11 396 + 23 Yearly -- 16103 + 1961 .... 393 + 32 03/04/05 < 512 17934 + 906 < 40 < 15 354 _ 20 05/20/05 < 102 3038 + 156 < 9 < 4 43 + 2 08/30/05 < 174 19106 + 964 < 18 < 15 491 _ 27

, 12/22/05 < 215 18959 + 969 < 22 < 19 311 _ 17 Yearly -- 14759 +/- 15662 .... 300 +/- 375 Overall -- 15431 +/- 1900 .... 346 +/- 131 Station CCWES040 - Calvert Cliffs Western Shores Station 4 02/24/04 < 297 17265 +/- 1010 < 30 < 13 199 _ 12 05/27/04 < 294 15208 + 895 < 27 < 13 167 + 11 08/30/04 < 306 16911 + 988 < 26 < 11 211 + 13 11/22/04 < 371 16308 + 958 < 32 < 13 214 + 13 Yearly -- 16423 +/- 1803 .... 198 +/- 43 03/04/05 < 440 16639 + 846 < 37 < 15 174 +/- 11 05/20/05 < 333 17542 +/- 892 < 30 < 15 228 +/- 13 08/30/05 < 154 16162 +/- 825 < 17 < 15 131 +/- 10 12/22/05 < 198 18718 + 947 < 20 < 16 154 + 9 Yearly -- 17265 +/- 2250 .... 172 +/- 83 Overall -- 16844 +/- 1191 .... 185 +/- 37 m m-m -m- n m-m - -m -m m -m m-m- m- -

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCFLP010 - Calvert Cliffs Flag Ponds Station 1 02/24/04 < 68 785 + 49 < 7 < 3 < 2 05/27/04 < 66 494 _ 33 < 6 < 3 < 3 08/30/04 < 66 812 + 50 < 6 < 2 2.1 + 0.4 11/22/04 < 71 416 _ 28 < 6 < 2 < 2 Yearly -- 627 + 402 .... 2.1 +/- 0.4 03/04/05 < 82 577 +/- 34 < 7 < 3 < 3 05/20/05 < 65 603 _ 35 < 6 < 3 1.6 +/- 0.4 08/30/05 27 +/-8 639 +/- 38 < 3 < 3 < 3 co 12/22/05 27 _ 11 744 + 41 < 4 < 2 1.6 + 0.4 Yearly 26.8 +/- 0.2 641 +/- 147 .... 1.59 + 0.01 Overall 26.8 +/- 0.2 634 +/- 20 -- 2 +/- 1 Station CCFLP020 - Calvert Cliffs Flag Ponds Station 2 02/24/04 < 199 5693 + 335 < 16 < 6 39 _ 3 05/27/04 < 90 4547 + 266 < 8 < 4 30 + 2 08/30/04 153 +/- 23 5408 +/- 319 < 12 < 6 35 +/- 2 11/22/04 238 +/- 53 4898 +/- 287 < 11 < 4 26 + 2 Yearly 195 +/- 120 5137 +/- 1025 .... 33 +/- 11 03/04/05 < 1.65 4777 +/- 242 < 13 < 5 24 +/- 2 05/20/05 144 +/- 51 5686 +/- 287 < 11 < 5 31 +/- 2 08/30/05 101 +/- 11 6162 +/- 311 < 7 < 5 36 +/- 2 12/22/05 80 +/- 26 5971 +/- 304 < 7 < 6 35 +/- 2 Yearly 109 _ 65 5649 +/- 1227 .... 32 +/- 11 Overall 152 +/- 123 5393 +/- 724 -- 32 +/- 2

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCFLP030 - Calvert Cliffs Flag Ponds Station 3 02/24/04 < 236 12719 + 744 < 23 < 10 319 + 19 05/27/04 < 259 13334 + 784 < 23 < 12 265 _ 16 08/30/04 < 258 14438 +/- 844 < 22 < 10 298 +/- 18 11/22/04 < 355 13738 +/- 808 < 29 < 12 305 +/- 19 Yearly -- 13557 + 1443 .... 297 +/- 46 03/04/05 < 463 15749 _ 803 < 38 < 15 253 +/- 14 05/20/05 < 336 16022 +/- 816 < 30 < 15 320 + 17 08/30/05 < 1`51 16265 + 828 < 16 < 15 349 + 19 12/22/05 < 159 15732 _ 794 < 16 < 13 270 _ 16 Yearly -- 15942 +/- 506 .... 298 + 88 Overall -- 14749 _ 3373 -- 297 +/- 2 Station CCFLP040 - Calvert Cliffs Flag Ponds Station 4 02/24/04 < 381 13395 +/- 788 < 32 < 12 113 +/- 7 05/27/04 < 246 14888 +/- 871 < 22 < 10 132 _ 8 08/30/04 < 334 15630 +/- 920 < 30 < 14 146 _ 9 11/22/04 < 352 16659 _ 973 < 27 < 10 366 + 22 Yearly -- 15143 +/- 2746 .... 189 +/- 237 03/04/05 < 486 19374 _ 978 < 39 < 15 164 +/- 9 05/20/05 < 379 19140 _ 968 < 33 < 16 171 +/- 12 08/30/05 < 175 19237 _ 975 < 19 < 17 138 _ 8 12/22/05 < 193 18073 _ 924 < 21 < 17 140 +/- 9 Yearly -- 18956 +/- 1193 .... 153 +/- 33 Overall -- 17049 + 5393 -- 171 +/- 51 M M M M M M M M M M M M M M M M M M M

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCCCO010 - Calvert Cliffs Outfall Station 1 02/24/04 < 514 4420 _ 275 < 41 < 15 14 + 2 05/27/04 < 305 4415 - 267 < 26 < 12 11 _ 2 08/30/04 46 _ 29 1041 - 63 < 7 < 3 2.6 + 0.4 11/22/04 < 105 1272 + 77 < 8 < 3 2.5 + 0.4 Yearly 46 +/- 29 2787 +/- 3770 .... 7 +/- 12 03/04/05 < 136 1362 +/- 72 < 11 < 4 < 4 05/20/05 < 91 1431 +/- 76 < 8 < 3 2.3 +/- 0.5 08/30/05 16 _ 7 1424 +/- 75 < 4 < 3 2.9 +/- 0.5

, 12/22/05 < 48 1309 +/- 72 < 5 < 4 3 +/- 1 Yearly 16 +/- 7 1381 +/- 115 .... 3 +/- 1 Overall 31 +/- 41 2084 +/- 1988 -- 5 +/- 7 Station CCCCO020 - Calvert Cliffs Outfall Station 2 02/24/04 < 212 5266 +/- 313 < 22 < 9 23 +/- 2 05/27/04 < 217 4124 +/- 251 < 20 < 10 15 +/- 2 08/30/04 < 71 1428 + 86 < 6 < 3 6 +/- 1 11/22/04 < 83 1359 + 83 < 7 < 3 5 + 1 Yearly -- 3044 +/- 3926 .... 12 +/- 17 03/04/05 < 128 1276 +/- 71 < 11 < 4 6 + 1 05/20/05 < 74 1581 +/- 84 < 7 < 3 7 +/- 1 08/30/05 55 + 15 1636 +/- 87 < 4 < 3 8 + 1 12/22/05 91 +/- 18 1950 +/- 101 < 4 < 3 8 + 1 Yearly 73 _ 52 1611 +/- 552 .... 7 _ 1 Overall 73 + 52 2328 + 2028 -- 10 +/- 7

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCCCO030 - Calvert Cliffs Outfall Station 3 02/24/04 < 95 3877 _ 228 < 8 < 3 69 + 4 05/27/04 < 58 3946 + 231 < 5 < 3 73 + 4 08/30/04 < 282 16676 + 976 < 24 < 12 404 + 24 11/22/04 < 258 13868 + 810 < 21 < 9 371 +/- 22 Yearly -- 9592 + 13317 .... 229 +/- 366 03/04/05 < 380 16689 _ 841 < 30 < 13 223 _ 12 05/20/05 < 298 15368 _ 777 < 26 < 13 205 + 12 08/30/05 < 146 18089 _ 913 < 15 < 14 390 _ 22 12/22/05 < 172 16786 _ 856 < 18 < 17 229 _ 13 0 Yearly -- 16733 +/- 2223 .... 262 +/- 172 Overall -- 13162 +/- 10099 -- 246 +/- 46 Station CCCCO040 - Calvert Cliffs Outfall Station 4 02/24/04 < 90 4100 + 241 < 8 < 3 58 +/- 4 05/27/04 < 56 3470 _ 204 < 5 < 3 47 +/- 3 08/30/04 < 278 16649 + 978 < 25 < 13 288 _ 17 11/22/04 < 277 15506 + 910 < 24 < 12 301 +/- 18 Yearly -- 9931 +/- 14234 .... 173 +/- 280 03/04/05 < 493 19572 + 996 < 42 < 18 359 + 20 05/20/05 < 309 17457 + 889 < 30 < 16 169 +/- .10 08/30/05 < :144 18252 + 929 < 17 < 16 248 + 14 12/22/05 < 157 17762 + 896 < 17 < 13 160 + 9 Yearly -- 18261 +/- 1866 .... 234 +/- 184 Overall 14096 +/- 11780 204 +/- 86 m- m m -m- -m- m -m n -m n -m m-m m-m m-

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCROP010 - Calvert Cliffs Rocky Point Station 1 02/24/04 < 74 720 + 45 < 6 < 3 1.4 + 0.3 05/27/04 < 59 602 _ 39 < 5 < 3 < 3 08/30/04 27 +/- 14 726 + 47 < 6 < 3 < 3 11/22/04 < 65 1213 + 74 < 6 < 3 < 3 Yearly 27 +/- 14 815 +/- 543 .... 1.4 +/- 0.3 03/04/05 < 101 772 _ 44 < 9 < 4 < 4 05/20/05 < 70 1020 +/- 56 < 6 < 3 2.0 _ 0.5 08/30/05 27 +/- 8 629 _ 37 < 3 < 3 < 3 12/22/05 < 36 875 + 49 < 4 < 3 3 _ 1 Yearly 27 +/- 8 824 +/- 331 .... 2 +/- 1 Overall 26.7 +/- 0.3 820 +/- 12 -- 2 +/- 1 Station CCROP020 - Calvert Cliffs Rocky Point Station 2 02/24/04 < 47 601 _ 37 < 3 < 1 < 2 05/27/04 < 39 468 _ 29 < 4 < 2 1.3 +/- 0.3 08/30/04 < 123 6762 + 396 < 11 < 6 82 _ 5 11/22/04 < 53 515 + 33 < 4 < 2 1.4 _ 0.3 Yearly -- 2086 +/- 6235 .... 28 +/- 93 03/04/05 < 82 551 +/- 31 < 7 < 2 1.9 _ 0.4 05/20/05 < 58 886 + 48 < 5 < 2 2.5 +/- 0.4 08/30/05 67 + 11 1313 + 69 < 3 < 3 6 +/- 1 12/22/05 < 31 611 + 35 < 3 < 2 2.1 +/- 0.4 Yearly 67 +/- 11 840 + 694 .... 3 +/- 4 Overall 67 +/- 11 1463 +/- 1762 -- 16 +/- 36

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCROP030 - Calvert Cliffs Rocky Point Station 3 02/24/04 < 334 14405 +/- 849 < 28 < 14 160 +/- 10 05/27/04 < 197 12325 +/- 725 < 19 < 11 131 +/- 9 08/30/04 < 323 17464 +/- 1029 < 30 < 17 257 +/- 16 11/22/04 < 299 15662 +/- 922 < 27 < 15 179 +/- 12 Yearly -- 14964 +/- 4322 .... 182 + 108 03/04/05 < 369 14804 +/- 753 < 32 < 14 172 +/- 10 05/20/05 < 289 14243 +/- 729 < 28 < 15 154 +/- 10 co 08/30/05 122 +/- 62 16178 _ 827 < 17 < 16 201 + 11 12/22/05 < 153 15617 +/- 799 < 17 < 16 157 +/- 11 Yearly 122 _ 62 15210 + 1714 .... 171 + 43 Overall 122 +/- 62 15087 +/- 348 -- 176 +/- 15 Station CCROP040 - Calvert Cliffs Rocky Point Station 4 02/24/04 < 187 13743 _ 802 < 14 < 6 179 +/- 11 05/27/04 < 168 14152 +/- 826 < 15 < 8 111 +/- 7 08/30/04 < 238 17319 + 1012 < 22 < 11 201 +/- 12 11/22/04 < 240 16331 +/- 954 < 20 < 9 254 +/- 15 Yearly -- 15386 +/- 3436 .... 186 +/- 119 03/04/05 < 332 17621 +/- 885 < 27 < 11 235 +/- 13 05/20/05 < 276 17550 +/- 884 < 25 < 13 166 +/- 9 08/30/05 < 122 18392 +/- 926 < 14 < 12 162 +/- 9 12/22/05 < .133 16492 +/- 835 < 15 < 13 256 +/- 14 Yearly -- 17514 +/- 1560 .... 205 +/- 96 Overall -- 16450 +/- 3009 .... 195 +/- 26 m----m-mm-m--m--m-mm-m --m - m-

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCLNG010 - Calvert Cliffs LNG Plant Pipeline Station 1 02/24/04 < 49 673 + 42 < 4 < 2 1.4 + 0.3 05/27/04 < 45 889 _ 54 < 4 < 2 3.1 + 0.4 08/30/04 37 + 19 760 + 47 < 4 < 2 < 2 11/22/04 < 49 999 + 60 < 4 < 2 1.8 + 0.3 Yearly 37 +/- 19 830 +/- 287 .... 2 +/- 2 03/04/05 < 85 586 _ 34 < 7 < 2 < 3 05/20/05 53 +/- 9 1272 +/- 67 < 6 < 3 2.4 _ 0.4 co 08/30/05 17 _ 7 828 _ 45 < 3 < 2 1.9 _ 0.4 12/22/05 37 +/- 10 1048 + 57 < 3 < 3 1.6 + 0.3 w Yearly 35 +/- 36 933 +/- 588 .... 2 +/- 1 Overall 36 +/- 2 882 +/- 146 -- 2.0 +/- 0.2 Station CCLNG020 - Calvert Cliffs LNG Plant Pipeline Station 2 02/24/04 < 182 8073 + 476 < 16 < 8 55 + 4 05/27/04 89 + 36 7604 + 448 < 12 < 8 49 + 3 08/30/04 442 + 56 7431 + 437 < 12 < 7 48 + 3 11/22/04 243 + 39 6623 _ 390 < 11 < 6 42 + 3 Yearly 258 +/- 353 7433 +/- 1209 .... 49 +/- 11 03/04/05 259 +/- 69 8387 _ 426 < 18 < 8 52 _ 3 05/20/05 391 + 81 8881 + 451 < 15 < 8 56 + 4 08/30/05 < 70 8038 + 409 < 8 < 8 58 +/- 4 12/22/05 341 + 51 11086 + 567 < 12 < 11 80 _ 5 Yearly 330 +/- 133 9098 +/- 2740 .... 62 +/- 25 Overall 294 +/- 102 8265 +/- 2355 -- 55 +/- 18

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCLNG030 - Calvert Cliffs LNG Plant Pipeline Station 3 02/24/04 < 180 13493 _ 790 < 14 < 8 103 +/- 7 05/27/04 < 183 12718 + 745 < 17 < 9 114 + 7 08/30/04 < 247 16091 + 943 < 23 < 12 138 + 9 11/22/04 < 143 11216 + 661 < 15 < 10 98 _ 6 Yearly -- 13379 + 4080 .... 113 +/- 36 03/04/05 < 425 17317 + 876 < 36 < 15 147 + 9 05/20/05 < 298 17045 + 862 < 27 < 14 157 + 9 08/30/05 209 _ 60 18658 _ 944 < 16 < 16 161 _ 9

- 12/22/05 294 +/- 71 17991 _ 913 < 19 < 17 145 _ 9 Yearly 251 _ 121 17753 +/- 1445 .... 153 +/- 15 Overall 251 +/- 121 15566 +/- 6185 -- 133 +/- 56 Station CCLNG040 - Calvert Cliffs LNG Plant Pipeline Station 4 02/24/04 < 190 17367 +/- 1014 < 18 < 10 14 _ 2 05/27/04 < 146 15719 _ 918 < 15 < 9 6 + 1 08/30/04 < 209 18137 +/- 1061 < 21 < 12 33 + 3 11/22/04 < 107 13944 _ 815 < 12 < 8 9 _ 1 Yearly -- 16292 +/- 3724 .... 16 +/- 24 03/04/05 < 274 18653 +/- 938 < 26 < 11 14 _ 2 05/20/05 < 222 18808 _ 947 < 22 < 12 16 + 2 08/30/05 < 91 18709 +/- 941 < 11 < 12 < 12 12/22/05 < 98 18311 +/- 922 < 11 < 11 17 +/- 2 Yearly -- 18620 +/- 432 .... 16 +/- 3 Overall -- 17456 +/- 3293 -- 15.8 +/- 0.5 m-m - -m -m m-m- -m- m -m m -m -- m -m

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCCOV010 - Calvert Cliffs Cove Point Station 1 02/24/04 < 122 5433 _ 321 < 11 < 6 24 _ 2 05/27/04 < 88 4661 +/- 274 < 8 < 5 23 _ 2 08/30/04 433 _ 52 5243 _ 309 < 10 < 6 25 _ 2 11/22/04 215 _ 39 5187 _ 306 < 8 < 5 24 + 2 Yearly 324 +/- 308 5131 +/- 662 .... 24 +/- 2 03/04/05 < 172 5271 _ 269 < 15 < 6 24 +/- 2 05/20/05 181 + 44 4954 _ 253 < 12 < 6 23 _ 2 08/30/05 106 _ 22 5361 - 273 < 6 < 6 27 _ 2

- 12/13/05 50 + 9 5241 + 267 < 7 < 6 23 + 2 01 Yearly 112 +/- 132 5207 +/- 352 .... 24 +/- 3 Overall 218 +/- 300 5169 +/- 107 -- 24.0 +/- 0.5 Station CCCOV020 - Calvert Cliffs Cove Point Station 2 02/24/04 <. 60 5142 + 301 < 5 < 3 31 +/- 2 05/27/04 < 84 6396 _ 374 < 8 < 5 39 _ 3 08/30/04 255 + 51 7367 _ 431 < 10 < 6 45 + 3 11/22/04 < 65 7349 +/- 430 < 5 < 4 29 _ 3 Yearly 255 +/- 51 6564 +/- 2102 .... 36 +/- 15 03/04/05 < 188 7766 + 391 < 15 < 6 48 +/- 3 05/20/05 153 +/- 49 8094 + 408 < 13 < 7 52 + 3 08/30/05 108 + 22 7346 + 370 < 6 < 6 46 + 3 12/13/05 262 +/- 43 9474 +/- 477 < 9 < 7 65 + 4 Yearly 174 +/- 159 8170 +/- 1843 .... 53 +/- 17 Overall 215 +/- 115 7367 +/- 2271 -- 44 +/- 24

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCCOV030 - Calvert Cliffs Cove Point Station 3 02/24/04 < 315 17196 + 1016 < 28 < 17 158 + 10 05/27/04 < 181 13163 + 774 < 18 < 12 123 + 8 08/30/04 < 257 15357 _ 906 < 24 < 15 137 _ 9 11/22/04 < 176 14348 _ 845 < 18 < 13 132 + 9 Yearly -- 15016 +/- 3415 .... 138 +/- 30 03/04/05 < 396 15742 _ 805 < 35 < 17 146 _ 10 05/20/05 < 312 16472 +/- 845 < 31 < 18 141 _ 10 08/30/05 < 142 17092 _ 876 < 17 < 18 151 _ 9 12/13/05 < 155 16124 _ 823 < 17 < 16 141 +/- 9 Yearly -- 16357 +/- 1147 .... 145 +/- 10 Overall 15687 +/- 1897 -- 141 +/- 10 Station CCCOV040 - Calvert Cliffs Cove Point Station 4 02/24/04 < 140 18145 _ 1057 < 12 < 6 < 7 05/27/04 < 140 17053 +/- 993 < 14 < 8 < 8 08/30/04 < 169 18387 _ 1071 < 16 < 9 17 _ 2 11/22/04 < 77 17635 _ 1027 < 8 < 7 < 6 Yearly -- 17805 +/- 1182 .... 17 +/- 2 03/04/05 < 249 17847 +/- 893 < 22 < 9 11 _ 1 05/20/05 < 283 26422 +/- 1325 < 26 < 15 16 _ 2 08/30/05 < 92 19143 _ 959 < 10 < 11 < 11 12/22/05 < 97 18741 +/- 938 < 11 < 10 < 10 Yearly -- 20538 +/- 7920 .... 14 +/- 7 Overall -- 19172 +/- 3865 -- 15 +/- 4 M M M M M M M M M M M M M M M M MM

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCLCP010 - Calvert Cliffs Little Cove Point Station 1 02/24/04 < 103 6587 +/- 388 < 9 < 6 86 +/- 6 05/27/04 < 152 13347 +/- 781 < 15 < 9 221 +/- 13 08/30/04 < 225 17061 +/- 999 < 21 < 12 199 +/- 12 11/22/04 < T03 11113 +/- 652 < 11 < 9 91 +/- 6 Yearly -- 12027 +/- 8757 .... 149 +/- 142 03/04/05 < 398 17097 +/- 865 < 32 < 14 167 +/- 9 05/20/05 < 334 19128 +/- 969 < 30 < 17 282 +/- 18 08/30/05 < 74 12627 +/- 635 < 8 < 8 190 +/- 10 12/13/05 < 136 15295 +/- 774 < 15 < 13 146 +/- 8 Yearly -- 16037 +/- 5520 .... 196 +/- 120 Overall -- 14032 +/- 5670 -- 173 +/- 66 Station CCLCP020 - Calvert Cliffs Little Cove Point Station 2 02/24/04 < 235 18733 +/- 1095 < 21 < 13 273 +/- 16 05/27/04 < 190 15364 +/- 904 < 19 < 13 164 +/- 11 08/30/04 < 271 19212 +/- 1131 < 27 < 17 176 +/- 13 11/22/04 < 162 16552 +/- 975 < 18 < 15 146 +/- 9 Yearly -- 17465 +/- 3635 .... 190 +/- 114 03/04/05 < 420 16357 +/- 840 < 36 < 18 136 +/- 8 05/20/05 < 309 18607 +/- 948 < 30 < 18 323 +/- 19 08/30/05 < 90 17522 +/- 884 < 11 < 12 19 +/- 5 12/13/05 < 155 19400 +/- 987 < 18 < 17 208 +/- 12 Yearly -- 17971 +/- 2647 .... 172 +/- 255 Overall -- 17718 +/- 715 .... 181 +/- 26

Table 1. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-58 Co-60 Cs-137 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCDRP010 - Calvert Cliffs Drum Point Station 1 02/24/04 < 233 17564 + 1030 < 22 < 15 142 _ 9 05/27/04 < 92 7282 + 427 < 9 < 6 79 + 5 08/30/04 368 + 39 11925 +/- 701 < 16 < 11 107 +/- 7 11/22/04 128 + 39 10161 _ 597 < 11 < 9 96 _ 6 Yearly 248 +/- 339 11733 + 8665 .... 106 +/- 53 03/04/05 < 203 9398 + 476 < 18 < 8 70 _ 4 05/20/05 < 185 10890 + 554 < 18 < 10 125 + 7 08/30/05 < 94 13632 + 693 < 11 < 12 163 + 9 12/13/05 < 104 12443 _ 632 < 12 < 11 146 _ 8 0o Yearly -- 11591 +/- 3686 .... 126 +/- 81 Overall 248 +/- 339 11662 +/- 201 -- 116 +/- 29 Station CCDRP020 - Calvert Cliffs Drum Point Station 2 02/24/04 < 222 14939 _ 880 < 21 < 14 128 +/- 8 05/27/04 < 156 14224 +/- 832 < 15 < 9 157 + 10 08/30/04 < 244 19721 _ 1155 < 23 < 14 247 _ 15 11/22/04 < 142 16752 _ 980 < 15 < 11 176 +/- 12 Yearly -- 16409 +/- 4902 .... 177 +/- 102 03/04/05 < 428 20078 +/- 1016 < 36 < 15 157 + 11 05/20/05 < 291 19161 _ 967 < 26 < 15 255 +/- 14 08/30/05 < 118 18627 + 940 < 13 < 14 258 + 14 12/13/05 < 155 19081 _ 963 < 17 < 15 183 +/- 10 Yearly -- 19237 +/- 1216 .... 213 +/- 102 Overall -- 17823 +/- 3999 -- 195 +/- 51 n-m- m n-m -m m-m- m-m -m n-m- n- m

Table 2. Radionuclide concentrations in oysters (pCi/kg +/- 2 sigma error)

Be-7 K-40 Ag-110m Co-60 Cs-137 DATE EXPOSURE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCKEBOOO - Calvert Cliffs Kenwood Beach Station 03/29/04 119 < 1014 19852 +/- 1424 < 97 < 112 < 104 07/02/04 95 < 745 16715 +/- 1183 < 76 < 93 < 78 09/23/04 83 < 1020 18359 +/- 1452 < 122 < 139 < 140 12/03/04 71 < 510 18539 +/- 1174 < 39 < 43 < 37 Yearly -- 18366 +/- 2573 ......

03/30/05 117 < 1130 14978 +/- 956 < 73 < 82 < 70 06/28/05 90 < 731 19504 +/- 1128 < 72 < 76 < 74 09/19/05 83 < 1018 17191 +/- 1099 < 81 < 89 < 81 12/01/05 74 < 838 14375 +/- 917 < 65 < 69 < 61 Yearly -- 16512 +/- 4666 ......

oW Overall -- 17439 +/- 2622 --

CD

Table 2. Radionuclide concentrations in oysters (pCi/kg +/- 2 sigma error)

Be-7 K-40 Ag-110m Co-60 Cs-137 DATE EXPOSURE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station CCPLSOOO - Calvert Cliffs Plant Site Station 03/29/04 119 < 1134 28228 +/- 1826 < 99 < 105 < 103 07/02/04 95 < 602 22031 +/- 1397 < 57 < 64 < 62 07/02/04 214 < 573 15689 +/- 1070 < 59 < 67 < 61 07/02/04 389 < 606 19730 +/- 1272 < 61 < 72 < 64 09/23/04 297 < 896 23618 +/- 1611 < 104 < 121 < 115 12/03/04 71 < 434 11533 +/- 745 < 35 < 38 < 33 12/03/04 154 < 219 10177 +/- 628 < 15 < 18 < 15 Yearly -- 18715 +/- 13170 ......

03/30/05 117 < 851 18256 + 1032 < 54 < 55 < 53 06/28/05 90 < 291 11650 + 681 < 31 < 36 < 35 06/28/05 207 < 300 11950 + 690 < 30 < 35 < 33 06/28/05 278 < 404 15025 + 847 < 43 < 47 < 46 06/28/05 361 < 314 13052 _ 720 < 33 < 35 < 36 09/19/05 83 < 1260 25986 _ 1471 < 92 < 86 < 91 12/01/05 74 < 555 13890 + 770 < 40 < 40 < 39 12/01/05 157 < 558 14287 _ 795 < 41 < 41 < 40 Yearly -- 15512 t 9419 ......

Overall -- 17113 +/- 4530 --

M M M M M M M M M M M M M M M M M M M

Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBLYHO10 - Peach Bottom Little Yellow House Station 1 06/11/04 482 + 120 11195 +/- 656 237 +/- 12 56 +/- 4 221 +/- 14 10/21/04 502 8615 +/- 502 < 5 32 +/- 2 < 27 Yearly 482 + 120 9905 +/- 3648 237 +/- 12 44 +/- 33 221 +/- 14 06/22/05 104 18859 +/- 942 < 9 < 10 < 31 10/14/05 141 + 41 12943 +/- 650 239 +/- 11 74 +/- 4 38 +/- 4 Yearly 141 +/- 41 15901 +/- 8366 239 +/- 11 74 +/- 4 38 +/- 4 Overall 311 +/- 482 12903 +/- 8479 238 +/- 3 59 +/- 43 130 +/- 258 Co Station PBLYH020 - Peach Bottom Little Yellow House Station 2 i~

06/11/04 438 + 157 13225 +/- 775 < 10 79 +/- 5

• 48 10/21/04 730 11082 +/- 648 < 8 66 +/- 4

• 44 Yearly 438 +/- 157 12153 +/- 3031 -- 72 +/- 18 06/22/05 112 15178 +/- 765 < 11 96 +/- 6

• 35 10/14/05 118 +/- 37 11112 +/- 558 18 +/- 2 58 +/- 3

• 26 Yearly 118 +/- 37 13145 +/- 5750 18 +/- 2 77 +/- 53 Overall 278 +/- 453 12649 +/- 1402 18 +/- 2 75 +/- 7 Station PBLYH030 - Peach Bottom Little Yellow House Station 3 06/11/04 K 409 13277 +/- 779 < 11 81 +/- 5

• 48 10/21/04 K 485 7980 +/- 465 < 5 22 +/- 2

• 28 Yearly 10628 +/- 7491 -- 51 +/- 83 06/22/05 108 15347 +/- 770 < 10 107 +/- 6

• 32 10/14/05 90 28 8156 +/- 409 6 +/- 1 29 +/- 2

• 20 Yearly 90 +/- 28 11751 +/- 10170 6 +/- 1 68 +/- 111 Overall 90 +/- 28 11190 +/- 1588 6 +/- 1 60 +/- 23

Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBBRC010 - Peach Bottom Broad Creek Station 1 06/11/04 < i 563 22329 +/- 1303 21 +/- 3 180 +/- 11

• 58 10/21/04 < 1075 17080 +/- 997 7 +/- 3 111 +/- 7 < 60 Yearly -- 19704 +/- 7424 14 +/- 20 146 +/- 97 06/22/05 293 +/- 46 14025 +/- 708 8 +/- 3 91 +/- 5

• 33 10/14/05 < 150 13495 +/- 684 28 +/- 3 82 +/- 5

• 41 Yearly 293 +/- 46 13760 +/- 750 18 +/- 28 87 +/- 14 Overall 293 +/- 46 16732 +/- 8406 16 +/- 6 116 +/- 83 co Station PBBRC020 - Peach Bottom Broad Creek Station 2 06/11/04 < 662 21364 +/- 1254 < 19 170 +/- 11

• 79 10/21/04 505 6490 +/- 381 < 6 31 +/- 2

• 31 Yearly 13927 +/- 21035 -- 101 +/- 197 06/22/05 201 17 9192 +/- 462 < 6 51 +/- 3

• 21 10/14/05 146 +/- 37 8752 +/- 440 29 +/- 2 47 +/- 3

• 23 Yearly 173 +/- 78 8972 +/- 623 29 +/- 2 49 +/- 5 Overall 173 .78 11449 +/- 7007 29 +/- 2 75 +/- 73 Station PBBRC030 - Peach Bottom Broad Creek Station 3 06/11/04 1053 +/- 235 18575 +/- 1087 < 14 130 +/- 8

• 56 10/21/04 < 552 6360 +/- 375 < 7 32 +/- 2

• 34 Yearly 1053 +/- 235 12467 +/- 17274 -- 81 +/- 138 06/22/05 141 + 29 6815 +/- 346 < 6 32 +/- 2 < 22 10/14/05 123 +/- 18 8308 +/- 423 10 +/- 2 52 +/- 3 < 29 Yearly 132 +/- 25 7561 +/- 2111 10 +/- 2 42 +/- 29 Overall 593 +/- 130"3 10014 +/- 6938 10 +/- 2 62 +/- 55

- n-m -- m- m-m - -m -m m-m- - m-m-m

Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBCOC010 - Peach Bottom Conowingo Creek Station 1 06/11/04 1634 + 264 21591 +/- 1268 17 +/- 5 174 +/- 11 < 80 10/21/04 1091 + 338 11067 +/- 651 < 11 69 +/- 5 < 51 Yearly 1362 + 768 16329 +/- 14883 17 +/- 5 122 +/- 147 --

06/22/05 226 + 44 13802 + 695 < 10 94 +/- 5 < 33 10/14/05 177 + 42 11126 _ 559 < 8 83 +/- 5 < 27 Yearly 202 +/- 70 12464 +/- 3785 -- 88 +/- 17 --

Overall 782 +/- 1641 14396 +/- 5466 17 +/- 5 105 +/- 47 Station PBCOC020 - Peach Bottom Conowingo Creek Station 2 06/11/04 889 _ 99 20029 +/- 1170 < 13 149 +/- 9 < 54 10/21/04 < 1146 20931 +/- 1221 < 13 130 +/- 8 < 65 Yearly 889 +/- 99 20480 +/- 1275 -- 139 +/- 27 --

06/22/05 370 _ 47 14217 +/- 717 < 11 103 +/- 6 < 33 10/14/05 136 _ 49 20600 +/- 1039 < 16 147 +/- 8 < 53 Yearly 253 +/- 330 17408 +/- 9027 -- 125 +/- 62 --

Overall 571 +/- 900 18944 +/- 4344 -- 132 +/- 20 --

Station PBCOC030 - Peach Bottom Conowingo Creek Station 3 06/11/04 1420 +/- 325 20827 +/- 1224 < 18 145 +/- 10 < 78 10/21/04 677 + 297 7648 +/- 455 < 11 51 +/- 4 < 52 Yearly 1048 +/- 1050 14238 +/- 18638 -- 98 +/- 132 --

06/22/05 490 _ 34 14891 +/- 751 < 11 113 +/- 6 < 36 10/14/05 265 + 32 15740 +/- 796 < 13 118 +/- 7 < 44 Yearly 378 +/- 318 15315 +/- 1200 -- 116 +/- 8 --

Overall 713 +/- 948 14777 +/- 1524 -- 107 +/- 25

Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBCOD010 - Peach Bottom Conowingo Dam Station 1

.06/11/04 < 323 15920 +/- 929 < 9 131 +/- 8 < 37 10/21/04 857 + 154 19731 +/- 1152 < 13 146 +/- 9 < 63 Yearly 857 +/- 154 17825 +/- 5390 -- 138 +/- 21 --

06/22/05 602 - 56 16153 +/- 812 < 11 122 +/- 7 < 36 10/14/05 231 _ 45 15385 +/- 773 7 + 2 111 +/- 6 < 36 Yearly 417 +/-- 524 15769 +/- 1087 7 +/- 2 116 +/- 16 --

Overall 637 +/-- 623 16797 +/- 2908 7 +/- 2 127 +/- 31 --

Station PBCOD020 - Peach Bottom Conowingo Dam Station 2 06/11/04 1545 _ 285 21926 +/- 1290 < 20 183 +/- 12 < 86 10/21/04 < 1132 18886 +/- 1107 < 16 134 +/- 9 < 74 Yearly 1545 + 285 20406 - 4299 -- 159 +/- 69 --

06/22/05 51 +/- 27 19464 +/- 984 < 15 157 +/- 9 < 48 10/14/05 256 + 52 18747 +/- 947 11 +/- 3 156 +/- 9 < 44 Yearly 154 + 289 19106 +/- 1013 11 +/- 3 157 +/- 2 --

Overall 849 + 1967 19756 +/- 1839 11 +/- 3 158 +/- 3 --

Station PBCOD030 - Peach Bottom Conowingo Dam Station 3 06/11/04 832 + 191 23717 +/- 1384 25 +/- 4 177 +/- 11 < 56 10/21/04 < 1164 22104 +/- 1289 < 14 148 +/- 9 < 69 Yearly 832 +/-- 191 22911 +/- 2282 25 +/- 4 163 +/- 41 --

06/22/05 790 +/- 64 18346 +/- 918 < 10 136 +/- 7 < 32 10/14/05 334 _ 55 17891 +/- 897 < 10 137 +/- 7 < 33 Yearly 562 +/- 644 18119 +/- 644 -- 137 - 2 --

Overall 697 + 382 20515 +/- 6777 25 - 4 150 - 37 --

m-m- m-m -m m-m- m- m - m-n m- m - m

Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBSRV030 - Peach Bottom Susquehanna River Station 3 06/11/04 < 93 2677 +/- 158 < 3 6 +/- 1 < 12 10/14/04 < 229 2527 +/- 150 < 3 5 +/- 1 < 15 Yearly -- 2602 +/- 212 -- 6 +/- 1 --

06/08/05 42 + 9 3111 +/- 158 < 3 6 +/- 1 < 9 10/04/05 31 +/- 13 2832 +/- 146 < 3 7 +/- 1 < 10 Yearly 36 +/- 15 2972 +/- 396 -- 7 +/- 2 Overall 36 +/- 15 2787 +/- 522 -- 6 +/- 2 Station PBSFLO10 - Peach Bottom Susquehanna Flats Station 1 06/11/04 93 +/- 39 4833 +/- 283 < 4 16 +/- 1 < 13 10/14/04 < 705 18102 +/- 1054 < 9 < 9 < 45 Yearly 93 +/- 39 11468 +/- 18766 -- 16 +/- 1 --

06/08/05 < 100 13913 +/- 700 < 9 < 9 < 30 10/04/05 < 85 13123 +/- 657 < 8 6 +/- 1 < 25 Yearly -- 13518 +/- 1117 -- 6 +/- 1 --

Overall 93 +/- 39 12493 +/- 2900 -- 11 +/- 14 --

Station PBSFL060 - Peach Bottom Susquehanna Flat Station 6 06/11/04 < 115 3056 +/- 181 < 4 6 +/- 1 < 16 10/14/04 < 336 3930 +/- 233 < 5 10 +/- 1 < 23 Yearly -- 3493 +/- 1236 -- 8 +/- 6 --

06/08/05 48 +/- 16 3758 +/- 193 < 4 11 +/- 1 < 15 10/04/05 121 +/- 24 3958 +/- 203 < 5 11 +/- 1 < 15 Yearly 84 +/- 104 3858 +/- 283 -- 10.7 +/- 0.4 --

Overall 84 +/- 104 3675 +/- 516 -- 9 +/- 4 --

Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBSFL070 - Peach Bottom Susquehanna Flat Station 7 06/11/04 45 +/- 22 2452 +/- 145 < 3 5 +/- 1 < 10 10/14/04 < 220 2893 +/- 170 < 3 6 +/- 1 < 14 Yearly 45 +/- 22 2673 +/- 624 -- 5 +/- 1 --

06/08/05 28 +/- 12 2950+/- 151 < 3 5 +/- 1 < 11 10/04/05 58 +/- 17 3735 +/- 189 < 3 12 _ 1 < 11 Yearly 43 +/- 43 3343 +/- 1110 -- 8 +/- 9 --

Overall 44 +/- 2 3008 +/- 948 -- 7 +/- 4 --

Station PBSFL080 - Peach Bottom Susquehanna Flat Station 8 06/11/04 149 +/- 52 4818 +/- 284 < 5 22 +/- 2 < 22

0) 10/14/04 < 574 10322 +/- 605 < 9 61 +/- 4 < 42 Yearly 149 + 52 7570 +/- 7783 -- 41 +/- 55 --

06/08/05 140 +/- 27 6863 +/- 348 < 6 42 +/- 3 < 21 10/04/05 151 +/- 14 7189 +/- 364 < 6 42 +/- 3 < 20 Yearly 145 +/- 16 7026 +/- 461 -- 41.8 +/- 0.2 --

Overall 147 +/- 6 7298 +/- 769 -- 41 +/- 1 Station PBSFL090 - Peach Bottom Susquehanna Flat Station 9 06/11/04 < 189 11025 +/- 643 < 7 71 +/- 4 < 28 10/14/04 862 +/- 268 15294 +/- 893 < 10 95 +/- 6 < 49 Yearly 862 +/- 268 13159 +/- 6036 -- 83 +/- 34 --

06/08/05 507 +/- 50 14703 +/- 738 < 10 98 +/- 6 < 31 10/04/05 436 +/- 54 12748 +/- 640 < 9 86 +/- 5 < 28 Yearly 472 +/- 100 13725 +/- 2764 -- 92 +/- 17 --

Overall 667 +/- 552 13442 +/- 801 -- 87 +/- 13 M-mM--- M- M- M M mM---MM

m-m-n- m-m - -m - -m - -m- -m- -m- -m-Table 3. Radionuclide concentrations in sediments (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Station PBUPB100 - Peach Bottom Upper Bay Station 10 06/11/04 143 +/- 30 10770 +/- 632 < 10 81 +/- 5 < 41 10/14/04 547 +/- 262 15424 +/- 905 < 14 106 +/- 7 < 65 Yearly 345 +/- 571 13097 +/- 6583 -- 93 +/- 35 06/08/05 < 101 12648 +/- 639 < 10 88 +/- 5 < 31 10/04/05 75 +/- 17 14021 +/- 708 < 11 95 +/- 6 < 35 Yearly 75 +/- 17 13334 +/- 1941 -- 92 +/- 9 Overall 210 +/- 382 13216 +/- 336 -- 93 +/- 2

Table 4. Radionuclide concentrations in finfish (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 SPECIES TYPE. DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR ERR CONC ERR Station PBLYHO10 - Peach Bottom Little Yellow House Station 1 M. salmoides & M. flesh 10/13/04 < 17897 16367 +/- 868 < 27 < 22 < 170 dolomieui Cyprinus carpio flesh 10/13/04 K 6011 13442

• 727 26 K 23 121 Cyprinus carpio flesh 10/13/04 K 7045 15805

• 827 26 K 22 117 Ictalurus sp. flesh 06/21/04 K 167500 27464

• 1639 135 K 1 24 796 Micropterus salmoides flesh 06/21/04 K 32986 20937

• 1116 38 K 31 229 Mixed freshwater fish flesh 06/21/04 K 72656 18913

• 1108 70 K 59 452 Mixed freshwater fish flesh 10/13/04 K 23926 16052 + 880 38 < 29 218 Porosoma cepedianum flesh 06/21/04 K 33907 20344 + 1059 32 < 27 197 Porosoma cepedianum flesh 10/13/04 K 23493 14887 + 791 29 K 27 177 flesh Yearly 18246 +/- 8536 K=

00 Cyprinus carpio flesh 06/22/05 K 1119 15702

• 850 30 26 101 K

Cyprinus carpio flesh 06/22/05 K 1102 15959

• 834 25 K 23 76 Cyprinus carpio flesh 06/22/05 K 1081 15758

• 847 26 < 24 95 Cyprinus carpio flesh 10/14/05 K 1726 16603 + 880 31 K 28 101 Ictalurus punctatus flesh 06/22/05 1985 16812

• 916 36 < 30 133 Ictalurus sp. flesh 06/22/05 K 3679 21379

• 1160 52 K 48 177 Ictalurus sp. flesh 10/14/05 K 1273 17293

• 926 30 < 27 106 Mixed freshwater fish flesh 06/22/05 K 5210 19131

• 1014 36 33 145 Porosoma cepedianum flesh 06/22/05 K 3306 15742

• 854 32 27 131 Stizostedion vitreum flesh 06/22/05 K 4390 19763

• 1053 35 27 148 Stizostedion vitreum flesh 10/14/05 K 1932 18143

• 987 39 15 + 7 133 Stizostedion vitreum flesh 10/14/05 K 2716 22708

• 1202 43 39 142 flesh Yearly 17916 +/- 4723 15 +/- 7 flesh Overall 18081 +/- 466 15 +/- 7

= ---

M- 1 M - - - - - - - - - - u

Table 4. Radionuclide concentrations in finfish (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 SPECIES TYPE DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR M. salmoides & M. gut 10/13/04

• 75517 8510 +/- 560 < 64

• 59

• 364 dolomieui Cyprinus carpio gut 10/13/04

• 15326 3988

• 308 44

• 38 K 200 Cyprinus carplo gut 10/,13/04

• 18554 6651

• 424 46

• 42

• 204 Ictalurus sp. gut 06/21/04

• 230952 19019

• 1303 176

• 166 K 1005 Ictalurus sp. gut 10/13/04

• 67231 4579

• 378 64

• 55 K 343 Micropterus dolomieui gut 06/21/04

• 215484 15962 + 1050 125 K 112

• 761 Micropterus salmoides gut 06/21/04 K 107000 5301

• 438 74

• 57

• 423 Moxostama spp. gut 06/21/04 K 243704 9548

• 858 157

• 128

• 985 Porosoma cepedianum gut 06/21/04

• 56747 4992 + 372 50

• 43 K 289 Porosoma cepedianum gut 10/13/04

• 57952 6803

• 430 49

• 44 K 269 gut Yearly 8535 +/- 1015 4

M. salmoides & M. gut 06/22/05 < 22000 14497 +/- 1011 < 127 K 125

• 478 dolomieui CD Cyprinus carpio gut 06/22/05 K 2769 5686 + 492 75

• 67

• 229 Cyprinus carpio gut 06/22/05 K 2780 8498 + 553 59

• 58

• 185 Cyprinus carpio gut 06/22/05 K 2579 4948

• 437 68 K 58 K 182 Ictalurus punctatus gut 06/22/05

• 3282 4684

• 376 55

• 47 K 177 Ictalurus sp. gut 06/22/05

• 3514 8311

• 523 49

• 50

• 158 Ictalurus sp. gut 10/14/05 K 2726 4106

• 339 56

• 46 K 164 Moxostama spp. gut 06/22/05 K 7218 4745

• 372 52

• 46 K 201 Porosoma cepedianum gut 06/22/05

• 6337 6336

• 438 51 K 45

• 198 Stizostedion vitreum gut 06/22/05

• 9042 6504

• 439 52

• 50 K 190 Stizostedion vitreum gut 10/14/05

• 4769 5259

• 462 79

• 65 K 237 Stizostedion vitreum gut 10/14/05 K 3386 5851

• 386 43

• 42

• 137 gut Yearly 6619 +/- 5664 gut Overall 7577 +/- 2710

Table 4. Radionuclide concentrations in finfish (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 Zn-65 SPECIES TYPE DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR Lepomis spp. whole 06/21/04 < 30956 13278 +/- 744 < 35 < 28 < 222 Lepomis spp. whole 06/21/04 < 35036 12873 +/- 696 < 32

• 28

• 188 Lepomis spp. whole 10/13/04 < 22568 13605 +/- 820 < 61

• 51 < 292 Lepomis spp. whole 10/13/04 < 15636 14479 +/- 789

• 38

• 34

• 181 whole Yearly 13559 +/- 1365 Lepomis spp. whole 06/22/05 < 4752 16512 +/- 881

• 33

• 31

• 137 Lepomis spp. whole 06/22/05 < 4763 15516 +/- 828

• 33

• 30

• 131 whole Yearly 16014 +/- 1409 whole Overall 14786 +/- 3472 0

= =mM-- M m M-n M M M M - - - m

Table 5. Radionuclide concentrations in submerged aquatic vegetation (pCi/kg +/- 2 sigma error)

Be-7 K-40 Co-60 Cs-137 1-131 SPECIES DATE CONC ERR CONC ERR CONC ERR CONC ERR CONC ERR ERR Station PBLYHO10 - Peach Bottom Little Yellow House 1 Myriophyllum spicatum 10/04/05 349 +/- 212 25686 +/- 1527 < 91

• 90 76 +/- 22 Myriophyllum spicatum 10/04/05 < 795 39972 +/- 2179 < 98

• 108 < 112 Myriophyllum spicatum 10/04/05 482 +/- 169 19342 +/- 1118 < 58

• 64 75 +/- 25 Myriophyllum spicatum Yearly 416 +/- 189 28333 +/- 21133 -- 76 +/- 1 Myriophyllum spicatum Overall 416 +/- 189 28333 +/- 21133 -- 76 +/- 1 Station PBFBTOOO - Peach Bottom Fishing Battery Station Myriophyllum spicatum 06/08/05 2054 +/- 294 23498 +/- 1477 < 120 < 111 675 +/- 55

,=& Myriophyllum spicatum 06/08/05 1269 +/- 190 20494 +/- 1183 < 74

• 77 345 +/- 34 Myriophyllum spicatum 10/04/05 397 +/- 154 24192 +/- 1327 < 68

• 77 < 116 Myriophyllum spicatum Yearly 1240 +/- 1658 22728 +/- 3931 -- 510 +/- 467 Myriophyllum spicatum Overall 1240 +/- 1658 22728 +/- 3931 -- 510 +/- 467 Vallisneria americana 10/04/05 < 728 57391 +/- 3089 < 102 < 97 < 141 Vallisneria americana Yearly -- 57391 +/-- 3089 --

Vallisneria americana Overall -- 57391 +/-- 3089 --