ML12131A523

2011 Annual Radiological Environmental Operating Report

ML12131A523
Person / Time
Site:	Millstone
Issue date:	04/30/2012
From:	Macmanus R Dominion, Dominion Nuclear Connecticut
To:	Document Control Desk, NRC/FSME, Office of Nuclear Reactor Regulation
References
12-246
Download: ML12131A523 (121)

Text

Dominion Nuclear Connecticut, Inc.

Millstone Power Station 03Dominion Rope Ferry Road Waterford, CT 06385 APR 3 0 2012 U.S. Nuclear Regulatory Commission Serial No.12-246 Attention: Document Control Desk MPS Lic/GJC RO Washington, DC 20555-0001 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 DOMINION NUCLEAR CONNECTICUT. INC.

MILLSTONE POWER STATION UNITS 1. 2. AND 3 2011 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT This letter transmits the Annual Radiological Environmental Operating Report for the Millstone Power Station, for the period January 2011 through December 2011. This satisfies the provisions of Section 5.7.2 of Millstone Power Station Unit 1 Permanently Defueled Technical Specifications (PDTS), and Sections 6.9.1.6a and 6.9.1.3 of the Millstone Power Station Units 2 and 3 Technical Specifications, respectively.

If you have any questions or require additional information, please contact Mr. William D. Bartron at (860) 444 4301.

Sincerely, R. K. MacManus Director, Nuclear Station Safety and Licensing

,r-.I

Serial No.12-246 2011 Annual Radiological Environmental Operating Report Page 2 of 4 Attachments: 1 Commitments made in this letter:

1. None.

cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 S. J. Giebel NRC Project Manager Millstone Unit 1 U.S. Nuclear Regulatory Commission Two White Flint North, Mail Stop T-8 F5 11545 Rockville Pike Rockville, MD 20852-2738 L. A. Kauffman NRC Inspector U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 J. D. Noggle NRC Inspector U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 J. S. Kim NRC Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-C2A 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

Serial No.12-246 2011 Annual Radiological Environmental Operating Report Page 3 of 4 (2copies)

Director Bureau of Air Management Monitoring & Radiation Division Department of Energy and Environmental Protection 79 Elm Street Hartford, CT 06106-5127 A. Honnellio Regional Radiation Representative (EPA Region 1, Boston)

U. S. Environmental Protection Agency (Region 1) 5 Post Office Square Suite 100 Boston, MA 02109 G. Allen Jr.

Department of Health and Human Services U. S. Food and Drug Administration 90 Madison St. Room 402 Worcester, MA 01608 R. Stein Chairman Connecticut Siting Council 10 Franklin Square New Britain, CT 06051 P. Kelley Waterford-East Lyme Shellfish Commission Waterford Town Hall Waterford, CT 06385 J. A. Martinez American Nuclear Insurers 95 Glastonbury Blvd.

Glastonbury, CT 06033 D. Carey Connecticut Department of Agriculture Aquaculture Division P. 0. Box 97 Millford, CT 06460

Serial No.12-246 2011 Annual Radiological Environmental Operating Report Page 4 of 4 D. Steward First Selectman Town of Waterford Waterford Town Hall Waterford, CT 06385 P. M. Formica First Selectman Town of East Lyme PO Box 519 Niantic, CT 06357 University Of Connecticut Library Serials Department Storrs, CT 06268

Serial No.12-246 Do)cket Nos. 50-245 50-336 50-423 Lice nse Nos. DPR-21 DPR-65 NPF-49 ATTACHMENT 1 2011 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT MILLSTONE POWER STATION UNITS 1, 2, AND 3 DOMINION NUCLEAR CONNECTICUT, INC. (DNC)

Millstone Power Station 2011 Radiological Environmental Operating Report January 1, 2011 - December 31, 2011 Dominion Nuclear Connecticut, Inc.

Unit License Docket 1 DPR-21 50-245 2 DPR-65 50-336 3 NPF-49 50-423 Dominion'

ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT MILLSTONE POWER STATION RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM 2011 Millstone Power Station Unit 1, DOCKET NO. 50-245 Millstone Power Station Unit 2, DOCKET NO. 50-336 Millstone Power Station Unit 3, DOCKET NO. 50-423 Dominion Nuclear Connecticut, Inc.

Waterford, Connecticut

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

- TABLE OFCONTENTS EXECUTIVE

SUMMARY

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1. INTRO DUCTIO N .................................................................................. 1-1 1.1 Overview ........................................................................................... 1-1 1.2 Radiation and Radioactivity .............................................................. 1-1 1.3 Sources of Radiation ........................................................................ 1-2 1.4 Nuclear Reactor O perations ............................................................. 1-3 1.5 Radioactive Effluent Control ............................................................. 1-8 1.6 Radiological Im pact on Hum ans ..................................................... 1-11

2. PROGRAM DESCRIPTION ........................................................................... 2-1 2.1 Sam pling Schedule and Locations ................................................... 2-1 2.2 Sam ples Collected During Report Period ......................................... 2-8

3. RADIOCHEMICAL RESULTS ........................................................................ 3-1 3.1 Sum m ary Table ................................................................................ 3-1 3.2 Data Tables ...................................................................................... 3-6

4. DISCUSSION OF RESULTS ......................................................................... 3-1 4.1 Gam m a Exposure Rate (Table 1) .................................................... 4-1 4.2 Air Particulate Gross Beta Radioactivity (Table 2) ........................... 4-3 4.3 Airborne Iodine (Table 3) ................................................................. 4-4 4.4 Air Particulate Gam m a (Table 4A-D) ............................................... 4-5 4.5 Air Particulate Strontium (Table 5) ................................................... 4-5 4.6 Soil (Table 6) ................................................................................... 4-5 4.7 Cow Milk (Table 7) ........................................................................... 4-5 4.8 Goat Milk (Table 8) .......................................................................... 4-5 4.9 Pasture Grass and Feed (Table 9) .................................................. 4-7 4.10 W ell W ater (Table 10) ...................................................................... 4-7 4.11 Reservoir W ater or Deer Meat (Table 11) ......................................... 4-7 4.12 Fruits and Vegetables (Table 12) .................................................... 4-7 4.13 Broad Leaf Vegetation (Table 13) .................................................... 4-8 4.14 Seawater (Table 14) ........................................................................ 4-8 4.15 Bottom Sedim ent (Table 15) ............................................................ 4-9 4.16 Aquatic Flora (Table 16) .................................................................. 4-9 4.17 Fish (Tables 17A and 17B) ............................................................ 4-10 4.17.1 Flounder (Table 17A) ....................................................... 4-10 4.17.2 Fish - Other (Table 17B) ................................................... 4-10 4.18 Mussels (Table 18) ........................................................................ 4-10 4.19 Oysters (Table 19) ......................................................................... 4-10 4.20 Clam s (Table 20) ........................................................................... 4-12 4.21 Scallops (Table 21) ........................................................................ 4-12 4.22 Lobsters (Table 22) ....................................................................... 4-12

5. OFFSITE DOSE EQUIVALENT COMMITMENTS ........................................... 5-1

6. DISCUSSION .............................................................................................. 6-1

7. REFERENCES ............................................................................................ 7-1 APPENDIX A - LAND USE CENSUS FOR 2011 ............................................ A-1 APPENDIX B -

SUMMARY

OF INTERLABORATORY COMPARISONS ............... B-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 EXECUTIVE

SUMMARY

INTRODUCTION This report summarizes the results of the Radiological Environmental Monitoring Program (REMP) conducted in the vicinity of MPS during the period from January 1 to December 31, 2011. This document has been prepared in accordance with the requirements of the MPS Units 1, 2 and 3 (MPS1, 2 and 3) Technical Specifications.

The REMP has been established to monitor the radiation and radioactivity released to the environment as a result of MPS's operation. This program, initiated in April 1967, includes the collection, analysis, and evaluation of radiological data in order to assess the impact of MPS on the environment and on the general public.

SAMPLING AND ANALYSIS The environmental sampling media collected in the vicinity of MPS and at distant locations included terrestrial samples in the form of air particulate filters, charcoal cartridges, soil, cow and goat milk, pasture grass, hay, well water, broadleaf vegetation, fruits and vegetables; and aquatic samples in the form of seawater, bottom sediment, aquatic flora, fish, mussels, oysters, clams and lobster.

During 2011, there were 1119 samples collected from the atmospheric, aquatic, and terrestrial environments. In addition, 174 exposure measurements were obtained using environmental thermoluminescent dosimeters (TLDs). A description of all discrepancies from the sample collection requirements in the Millstone Radiological Effluent Monitoring and Offsite Dose Calculation Manual (REMODCM) is presented in the Notes for the Data Tables of this report.

There were 1247 analyses performed on the environmental media samples. Teledyne Brown Engineering, Inc. of Knoxville, Tennessee performed the analyses as required by the MPS REMODCM.

LAND USE CENSUS The annual land use census in the vicinity of MPS was conducted as required by the MPS REMODCM during 2011. Although broadleaf sampling may be used in lieu of a garden census, gardens were included in the 2011 census. Only vegetable gardens having an area of more than 500 square feet need to be identified. Due to the difficulty of measuring individual gardens, the nearest garden within each directional sector identified by a drive-by survey is listed in Appendix A. No new dairy animals within 10 miles of the MPS were located during the census. Monthly broad leaf sampling was also performed; it may be used in lieu of the garden census.

RADIOLOGICAL IMPACT TO THE ENVIRONMENT The predominant radioactivity for many samples was from non-plant related sources, such as fallout from nuclear weapons tests and naturally occurring radionuclides.

There was no plant related activity detected in any of the terrestrial samples collected as part of the MPS REMP.

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Several aquatic samples did show plant related activity- Monitoring of seawater in the area of the discharge indicated the presence of the tritium, a station related radionuclide. Tritium was only found onsite inside the mixing zone of the quarry discharge at levels that were expected from routine plant operation. Radioactive iodine was found in three flora (seaweed) samples, one at the discharge point and two in Jordon Cove just east of the discharge point. In addition, radioactive silver (Ag-110m) was found in four samples taken in the Millstone Quarry prior to the discharge point. No radioactivity was found in edible seafood sampled beyond the discharge point.

Offsite ambient radiation measurements using environmental TLDs beyond the site boundary ranged between 39 and 96 milliRoentgens per year. The range of ambient radiation levels observed with the TLDs is consistent with natural background radiation levels for Connecticut.

Several REMP samples during 2011 identified detectable positive radioactivity that could be attributed to the trans-Pacific transport of airborne releases from Fukushima, Japan following the March 11, 2011 Tohoku earthquake. Discussions in the report for each sample type containing such radioactivity explain why the radioactivity is not related to the operations of MPS.

RADIOLOGICAL IMPACT TO THE GENERAL PUBLIC During 2011, radiation doses to the general public as a result of MPS's operation continued to be well below the federal limits and much less than the dose due to other sources of man-made (e.g., X-rays, medical) and naturally-occurring (e.g., cosmic, radon) radiation.

The calculated total body dose to the maximally exposed member of the general public from radioactive effluents and ambient radiation resulting from MPS operations for 2011 was approximately 0.2 mrem* for the year. This conservative estimate is well below the Environmental Protection Agency's (EPA) annual dose limit to any member of the general public and is a fraction of a percent of the typical dose received from natural and other sources of man-made radiation.

• The term 'mrem' used in this report is a unit of radiation dose. The letter 'm' is for 'milli', or one-thousandth of a 'rem.' The word 'rem' is an acronyn for roentgen equivalent man. One rem is equal to a rad multiplied by factors to account for type of radiation and distribution within the body. The word 'rad' is an acronyn for radiation absorbed dose. One rad is equal to the absorption of 100 ergs of energy per gram of tissue.

CONCLUSIONS The 2011 REMP for MPS resulted in the collection and analysis of over a thousand environmental samples and measurements. The data obtained were used to determine the impact of MPS's operation on the environment and on the general public.

An evaluation of direct radiation measurements, environmental sample analyses, and dose calculations indicates all applicable federal criteria were met. Furthermore, radiation levels and resulting doses from station operation were a small fraction of those attributed to natural and man-made background radiation.

Based on this information, there is no significant radiological impact on the environment or on the general public due to MPS's operation.

ii

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

1. INTRODUCTION This section provides an overview of the MPS REMP. It also includes background information to allow a reader to have an informed understanding of radiation and nuclear power operation.

1.1 Overview The REMP for 2011 performed by Dominion Nuclear Connecticut (DNC) for MPS is discussed in this report. Since the operation of a nuclear power plant results in the release of small amounts of radioactivity and low levels of radiation, the Nuclear Regulatory Commission (NRC) requires a program be established to monitor radiation and radioactivity in the environment (Reference 1). This report, published annually per MPS's Technical Specifications (section 5.7.2 for MPS1, section 6.9.1.6 for MPS2 and Section 6.9.1.3 for MPS3), summarizes the results of measurements of radiation and radioactivity in the environment in the vicinity of the MPS and at distant locations during the period January 1 to December 31 , 2011.

The REMP consists of taking radiation measurements and collecting samples from the environment, analyzing them for radioactivity content, and interpreting the results. With emphasis on the critical radiation exposure pathways to humans, samples from the aquatic, atmospheric, and terrestrial environments are collected. These samples include, but are not limited to: air, soil, cow and goat milk, pasture grass, hay, well water, broadleaf vegetation, fruits, vegetables, seawater, bottom sediment, aquatic flora, fish, mussels, oysters, clams and lobster. Thermoluminescent dosimeters (TLDs) are placed in the environment to measure gamma radiation levels. The TLDs are processed and the environmental samples are analyzed to measure the very low levels of radiation and radioactivity present in the environment as a result of MPS operation and other natural and man-made sources. These results are reviewed by MPS's radiological staff and have been reported semiannually or annually to the NRC and others for over 30 years.

In order to more fully understand how a nuclear power plant impacts humans and the environment, background information on radiation and radioactivity, natural and man-made sources of radiation, reactor operations, radioactive effluent controls, and radiological impact on humans is provided. It is believed that this information will assist the reader in understanding the radiological impact on the environment and humans from the operation of MPS.

1.2 Radiation and Radioactivity All matter is made of atoms. An atom is the smallest component into which matter can be broken down and still maintain all its chemical properties. Nuclear radiation is energy, in the form of waves or particles that is given off from atoms in an excited state (e.g., unstable, radioactive atoms).

Radioactive material exists naturally and has always been a part of our environment. The earth's crust, for example, contains radioactive uranium, radium, thorium, and potassium.

Some radioactivity is a result of nuclear weapons testing. Examples of radioactive fallout that is normally present in environmental samples are cesium-137 and strontium-90. Some examples of radioactive materials released from a nuclear power plant are cesium-137, iodine-131, strontium-90, and cobalt-60.

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Radiation is measured in units of mrem, much like temperature is measured in degrees. A mrem (mrem) is a measure of the biological effect of the energy deposited in tissue. The letter 'm' is for 'milli', or one-thousandth of a 'rem.' The word 'rem' is an acronyn for roentgen equivalent man. One rem is equal to a 'rad' multiplied by factors to account for type of radiation and distribution within the body. The word 'rad' is an acronyn for radiation absorbed dose. One rad is equal to the absorption of 100 ergs of energy per gram of tissue.

The natural and man-made radiation dose received in one year by the average American is 300 to 600 mrem (References 2, 3, 4, and 5). The per capita dose has increased substantially since the mid 1980's because of the increased usage of medical procedures involving exposure to radiation (see Reference 3).

Radioactivity is measured in Curies. Levels of radioactivity commonly seen in the environment are typically a small fraction of a Curie, therefore radioactivity in the environment is typically measured in picocuries. One picocurie (pCi) is equal to 0.037 disintegrations per second (2.22 disintegrations per minute).

1.3 Sources of Radiation As mentioned previously, naturally occurring radioactivity has always been a part of our environment. Table 1.3 shows the sources and doses of radiation from natural and man-made sources.

Table 1.3 Radiation Sources and Correspondinq Doses (1)

NATURAL MAN-MADE Radiation Dose Radiation Dose Source (mrem/year) Source (mrem/year)

Internal, inhalation(2) 228 Medical(3) 300 External, space 33 Consumer(4) 13 Internal, ingestion 29 Industrial, security, (5) 0.3 External, terrestrial 21 Occupational 0.5 Weapons Fallout < 1 Nuclear Power Plants < 1 Approximate Total 311 Approximate Total 314 (1) information from References 3 and 4 (2) from radon and thoron (3) includes computerized tomography (147 mrem), nuclear medicine (77 mrem), interventional fluoroscopy (43 mrem) and conventional radiography and fluoroscopy (33 mrem)

(4) primarily from cigarette smoking (4.6 mrem), commercial air travel (3.4 mrem), building materials (3.5 mrem) and mining and agriculture (0.8 mrem)

(5) Industrial, security, medical, educational and research 1-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Cosmic radiation (external, space) from the sun and outer space penetrates the earth's atmosphere and continuously bombards us with rays and charged particles. Some of this cosmic radiation interacts with gases and particles in the atmosphere, making them radioactive. These radioactive byproducts from cosmic ray bombardment are referred to as cosmogenic radionuclides. Isotopes such as beryllium-7 and carbon-14 are formed in this way. Exposure to cosmic and cosmogenic sources of radioactivity results in about 30 mrem of radiation dose per year.

Additionally, natural radioactivity is in our body and in the food we eat (about 30 mrem/year),

the ground we walk on (about 20 mrem/year) and the air we breathe (about 230 mrem/year).

The majority of a person's annual dose results from exposure to radon and thoron in the air we breathe. These gases and their radioactive decay products arise from the decay of naturally occurring uranium, thorium and radium in the soil and building products such as brick, stone, and concrete. Radon and thoron levels vary greatly with location, primarily due to changes in the concentration of uranium and thorium in the soil. Residents at some locations in Colorado, New York, Pennsylvania, New Jersey and even Connecticut have a higher annual dose as a result of higher levels of radon/thoron gases in these areas. In total, these various sources of naturally-occurring radiation and radioactivity contribute to a total dose of about 310 mrem per year.

In addition to hatural radiation, we are normally exposed to radiation from a number of man-made sources. The single largest doses from man-made sources result from therapeutic and diagnostic applications of x-rays and radiopharmaceuticals. The annual dose to an individual in the United States from medical and dental exposure is approximately 300 mrem.

Consumer products/uses, such cigarettes, building materials and commercial air travel contribute about 10 mrem/year. Much smaller doses result from weapons fallout (less than 1 mrem/year) and nuclear power plants (less than 1 mrem/year). Typically, the average person in the United States receives approximately 310 mrem per year from man-made sources.

1.4 Nuclear Reactor Operations MPS generates about 2100 megawatts of electricity at full power, which provides approximately one-third of the power consumed in the State of Connecticut. MPS2 and MPS3 are pressurized water reactors (MPS1, which is permanently shutdown, was a boiling water reactor). The nuclear station is located on an approximate 500-acre site about 5 kilometers (three miles) west of New London, Connecticutt. Commercial operation of MPS2 began in December 1975 and MPS3 in May 1986.

MPS was operational during most of 2011, with the exception of a refueling outage at MPS2 in April and at MPS3 in October. The annual capacity factors for MPS2 was 85.6% and for MPS3 was 87.6%.

Nuclear-generated electricity is produced by many of the same techniques used for conventional oil and coal-generated electricity. Both systems use heat to boil water in order to produce steam. The steam turns a turbine, which turns a generator, producing electricity.

In both cases, the steam passes through a condenser where it changes back into water and re-circulates back through the system. The cooling water source for MPS is the Niantic Bay.

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 The key difference between nuclear power and conventional power is the source of heat used to boil the water. Conventional plants burn fossil fuels in a boiler, while nuclear plants use uranium fission in a nuclear reactor.

Inside the reactor, a nuclear reaction called fission takes place. Particles, called neutrons, strike the nucleus of a uranium-235 atom, causing it to split into fragments called radioactive fission products. The splitting of the atoms releases both heat and more neutrons. The newly-released neutrons then collide with and split other uranium atoms, thus making more heat and releasing even more neutrons, and on and on until the uranium fuel is depleted or spent. This process is called a chain reaction. When this chain reaction is self sustaining, the reactor is called "critical."

The operation of a nuclear reactor results in the release of small amounts of radioactivity and low levels of radiation. The radioactivity originates from two major sources, radioactive fission products and radioactive activation products. Radioactive fission products, as illustrated in Figure 1.4-1 (Reference 6), originate from the fissioning of the nuclear fuel.

These fission products get into the reactor coolant from their release by minute amounts of uranium on the outside surfaces of the fuel cladding, by diffusion through the fuel pellets and cladding and, on occasion, through defects or failures in the fuel cladding. These fission products circulate along with the reactor coolant water and will deposit on the internal surfaces of pipes and equipment. The radioactive fission products on the pipes and equipment emit radiation. Examples of some fission products are krypton-85 (Kr-85),

strontium-90 (Sr-90), iodine-131 (1-131), xenon-133 (Xe-133), and cesium-137 (Cs-137).

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Nuclear Fission Fission is the splitting of atoms (e.g., uranium-235) by a neutron to release heat and more neutrons, creating a chain reaction. Radiation and fission products are by-products of the process.

Uranium Radiation Neutron Neutrons Uranium Uranium Fission Products Figure 1.4-1 Radioactive Fission Product Formation 1-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Radioactive activation products (see Figure 1.4-2), on the other hand, originate from two sources. The first is by neutron bombardment of the hydrogen, oxygen and other gas (helium, argon, nitrogen) molecules in the reactor cooling water. The second is a result of the fact that the internals of any piping system or component are subject to minute yet constant corrosion from the reactor cooling water. These minute metallic particles (for example: nickel, iron, cobalt, or magnesium) are transported through the reactor core into the fuel region, where neutrons may react with the nuclei of these particles, producing radioactive products. So, activation products are nothing more than ordinary naturally-occurring atoms that are made unstable or radioactive by neutron bombardment. These activation products circulate along with the reactor coolant water and will deposit on the internal surfaces of pipes and equipment. The radioactive activation products on the pipes and equipment emit radiation. Examples of some activation products are manganese-54 (Mn-54), iron-59 (Fe-59), cobalt-60 (Co-60), and zinc-65 (Zn-65).

collision with Stable Radioactive Neutron Cobalt Nucleus Cobalt Nucleus Figure 1.4-2 Radioactive Activation Product Formation At MPS there are five independent protective barriers that confine these radioactive materials. These five barriers, which are shown in Figure 1.4-3 (Reference 6), are:

0 fuel pellets; 0 fuel cladding; 0 reactor vessel and associated piping and equipment; 0 primary containment and, 0 secondary containment (enclosure building).

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 SIMPLIFIED DIAGRAM OF A PRESSURIZED WATER REACTOR Pressurized water reactor-common type of Light Water Reactor (LWR)

- WATER WCETAKIN VONENER COCUNG WASTE HEfAT To THE ENV~toNMENT Figure 1.4-3 The ceramic uranium fuel pellets provide the first barrier. Most of the radioactive fission products are either physically trapped or chemically bound between the uranium atoms, where they will remain. However, a few fission products that are volatile or gaseous may diffuse through the fuel pellets into small gaps between the pellets and the fuel cladding.

The second barrier, the fuel cladding, consists of zirconium alloy tubes that confine the fuel pellets. The small gaps between the fuel and the cladding contain the noble gases and volatile iodines that are types of radioactive fission products. This radioactivity can diffuse to a small extent through the fuel cladding into the reactor coolant water.

The third barrier consists of the reactor pressure vessel, steel piping and equipment that confine the reactor cooling water. The reactor pressure vessel, which holds the reactor fuel, is typically a steel tank 40 feet high by 14 feet in diameter with walls about five to nine inches thick. These vessels and associated piping provide containment for radioactivity in the primary coolant and the reactor core. However, during the course of operations and maintenance, small amounts of radioactive fission and activation products can escape through valve leaks or upon breaching of the primary coolant system for maintenance.

The fourth barrier is the primary containment. It is a cylindrical enclosure with approximately five-foot thick steel reinforced concrete walls lined by steel on the inside. Small amounts of radioactivity may be released from primary containment during operation to maintain proper containment pressure and during maintenance and refueling outages.

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 The fifth barrier is the secondary containment or enclosure building. The enclosure building is a steel building that surrounds the primary containment. This barrier is an additional safety feature at MPS's reactor units to contain radioactivity that may escape from the primary containment. This enclosure building is equipped with a filtered ventilation system that is used when needed to reduce the radioactivity that escapes from the primary containment.

The five barriers confine most of the radioactive fission and activation products. However, small amounts of radioactivity do escape via mechanical failures and maintenance on valves, piping, and equipment associated with the reactor cooling water system. The small amounts of radioactive liquids and gases that do escape the various containment systems are further controlled by the liquid purification and ventilation filtration systems. Also, prior to a release to the environment, control systems exist to collect and purify the radioactive effluents in order to reduce releases to the environment to as low as is reasonably achievable. The control of radioactive effluents at MPS will be discussed in more detail in the next section.

1.5 Radioactive Effluent Control The small amounts of radioactive liquids and gases that might escape the first two barriers are purified in the liquid and gaseous waste treatment systems, then monitored for radioactivity, and released only if the radioactivity levels are below the federal release limits.

Radioactivity released from the liquid effluent system to the environment is limited, controlled, and monitored by a variety of systems and procedures which include:

• reactor water cleanup system;

• liquid radwaste treatment system;

• sampling and analysis of the liquid radwaste tanks; and,

• liquid waste effluent discharge radioactivity monitor.

The purpose of the reactor water cleanup system is to continuously purify the reactor cooling water by removing radioactive atoms and non-radioactive impurities that may become activated by neutron bombardment. A portion of the reactor coolant water is diverted from the primary coolant system and is directed through ion exchange resins where radioactive elements, dissolved and suspended in the water, are removed through chemical processes.

The net effect is a substantial reduction of the radioactive material that is present in the primary coolant water and consequently the amount of radioactive material that might escape from the system.

Reactor cooling water that might escape the primary cooling system and other radioactive water sources are collected in floor and equipment drains. These drains direct this radioactive liquid waste to large holdup tanks. The liquid waste collected in the tanks is purified again using the liquid radwaste treatment system, which consists of a filter and ion exchange resins.

Processing of liquid radioactive waste results in large reductions of radioactive liquids discharged into Niantic Bay. Wastes processed through liquid radwaste treatment can be purified and when necessary the processed liquid is re-used in plant systems.

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Prior to release, the radioactivity in the liquid radwaste tank is sampled and analyzed to determine if the level of radioactivity is below the release limits and to quantify the total amount of radioactive liquid effluent that would be released. If the levels are below the federal release limits, the tank is drained to the liquid effluent discharge header.

This liquid waste effluent discharge line is provided with a shielded radioactivity monitor. This detector is connected to a radiation level meter and a recorder in the Control Room. The radiation alarm is set so that the detector will alarm before radioactivity levels exceed the release limits. The liquid effluent discharge header has an isolation valve. If an alarm is received, the liquid effluent discharge valve will automatically close, thereby terminating the release to the Niantic Bay and preventing any liquid radioactivity from being released that may exceed the release limits. An audible alarm notifies the Control Room operator that this has occurred.

Some liquid waste sources, which have a low potential for containing radioactivity, and/or may contain very low levels of contamination, may be discharged directly to the Long Island Sound. One such source of liquid is the turbine building sump. However, periodic representative samples are collected for analysis of radioactivity content to track the amounts of radioactivity being discharged.

Another means for adjusting liquid effluent concentrations to below federal limits is by mixing plant cooling water from the condenser with the liquid effluents in the discharge canal. This larger volume of cooling water further lowers the radioactivity levels to below the release concentration limits.

The preceding discussion illustrates that many controls exist to reduce the radioactive liquid effluents released to the Niantic Bay to as far below the release limits as is reasonably achievable.

Radioactive releases from the radioactive gaseous effluent system to the environment are limited, controlled, and monitored by a variety of systems and procedures which include:

• containment building ventilation system;

• containment building radioactivity monitors;

• sampling and analysis of containment building vent and purge effluents;

• process gas treatment system;

• auxiliary building (and engineered safeguards and fuel building for MPS3) ventilation system;

• stack and vent effluent radioactivity monitors;

• sampling and analysis of stack and vent effluents;

• process radiation monitors; and

• steam jet air ejector (SJAE) monitor The primary sources of gaseous radioactive waste are degassing of the primary coolant, gaseous liquid drains, and gaseous vents. Additional sources of gaseous waste activity include ventilation air released from the auxiliary building and purging and venting of the containment building. The radiation level meter and recorders for the effluent radioactivity monitors are located in the Control Room. The plant process computer aids in tracking the monitor readings. To supplement the information continuously provided by the detector, air samples are taken periodically from the containment, stack and vents. These samples are analyzed to quantify the total amount of tritium and radioactive gaseous and particulate effluents released.

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Gases from the primary coolant are held up in waste gas decay tanks for decay at MPS2.

Gaseous waste at MPS3 is purified through a process gas system, consisting of high-efficiency particulate air filters and charcoal adsorber beds. Gases from periodic venting of the MPS2 containment are released through a similar process system (Enclosure Building Filtration System) while gases from the MPS3 containment vacuum pumps are released without treatment. If necessary, MPS3 containment air can be filtered by an internal particulate and charcoal treatment system. Containment purges (purge is the forced ventilation process while containment vents are pressure releases) for MPS2 are filtered by high-efficiency particulate filters while at MPS3 these are not normally filtered. If necessary, particulate and charcoal filters can be used for these purges.

The auxiliary building ventilation system provides for ventilation of the auxiliary building and enclosure building (and service building and contiguous areas, waste disposal building, and fuel building for MPS3, for MPS2 these are all part of the auxiliary building). Normally, the air from the ventilation of these areas will exhaust through the ventilation vent (which has a particulate filter for MPS2). If exhaust from these areas reaches a predetermined level, the ventilation flow can be diverted by operator control to a particulate and charcoal filtration system.

Therefore, for both liquid and gaseous releases, radioactive effluent control systems exist to collect and purify the radioactive effluents in order to reduce releases to the environment to as low as is reasonably achievable. The effluents are always monitored, sampled and analyzed to make sure that radioactivity levels are below the release limits. If the release limits are being approached, isolation valves in some of the waste effluent lines will automatically shut to stop the release, or Control Room operators can implement procedures to ensure that federal regulatory limits are always met.

1-10

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 1.6 Radiological Impact on Humans The final step in the effluent control process is the determination of the radiological dose impact to humans and comparison with the federal dose limits to the public. This step is performed in three stages. As mentioned previously, the purpose of continuous radiation monitoring and periodic sampling and analysis is to measure the quantities of radioactivity being released to determine compliance with the radioactivity release limits. This is the first stage for assessing releases to the environment.

The second stage is calculations of the dose impact to the general public from MPS's radioactive effluents are performed. The purpose of these calculations is to periodically assess the doses to the general public resulting from radioactive effluents to ensure that these doses are being maintained as far below the federal dose limits as is reasonably achievable. This is the second stage for assessing releases to the environment.

The types and quantities of radioactive liquid and gaseous effluents released from MPS during each given year are reported to the NRC annually in the Radiological Effluent Release Report (RERR). Similar to this report, the RERR is submitted annually to the NRC. Section 5 of this report discusses the detailed dose calculations from the RERR and provides a comparison to REMP dose calculations. The liquid and gaseous effluents were well below the federal release limits and were a small percentage of the MPS REMODCM effluent control limits.

The measurements of the physical and chemical nature of the effluents are used to determine how the radionuclides will interact with the environment and how they can result in radiation exposure to humans. The environmental interaction mechanisms depend upon factors such as the hydrological (water) and meteorological (atmospheric) characteristics in the area. Information on the water flow, wind speed, wind direction, and atmospheric mixing characteristics are used to estimate how radioactivity will distribute and disperse in the ocean and the atmosphere.

The most important type of information that is used to evaluate the radiological impact on humans is data on the use of the environment. Information on fish and shellfish consumption, boating usage, beach usage, locations of cows and goats, locations of residences, locations of gardens, drinking water supplies, and other usage information are utilized to estimate the amount of radiation and radioactivity received by the general public.

The radiation exposure pathway to humans is the path radioactivity takes from its release point at MPS to its effect on man. The movement of radioactivity through the environment and its transport to humans is portrayed in Figure 1.6.

1-11

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 EXAMPLES OF MPS'S RADIATION EXPOSURE PATHWAYS

....... . ....I............

LIQUID EFFLUENTS

3. DIRECT RADIATION

4. DIRECT RADIATION

_ (SOIL DEPOSITION) 1. DIRECT RADIATION (AIR SUBMERSION)

1. SHORELINE DIRECT RADIATION ti' (FISHING, PICNICJNG) 5. CONSUMPTION (VEGETATION)

2. DIRECT RADIATION Q DEPOSITION (IMMERSION IN OCEAN, BOATING, SWIMMING) 6 CONSUMPTION DEPOSITION (MILK AND MEAT) r%'%,

J INGESTION I ký 11joulvir- I IWIN (FISH, SHELLFISH) L11.

......... .......... ................ INGESTION Figure 1.6 Radiation Exposure Pathways 1-12

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 There are three major pathways in which liquid effluents affect humans:

" external radiation from liquid effluents that deposit and accumulate on the shoreline;

• external radiation from immersion in ocean water containing radioactive liquids; and,

• internal radiation from consumption of fish and shellfish containing radioactivity absorbed from the liquid effluents.

There are six major ways in which gaseous effluents affect humans:

• external radiation from an airborne plume of radioactivity;

• internal radiation from inhalation of airborne radioactivity;

• external radiation from deposition of radioactive effluents on soil;

• ambient (direct) radiation from contained sources at the power plant;

• internal radiation from consumption of vegetation containing radioactivity deposited on the vegetation from airborne deposition and absorbed from the soil due to ground deposition of radioactive effluents; and,

• internal radiation from consumption of milk and meat containing radioactivity deposited on forage that is eaten by cattle and other livestock.

In addition, ambient (direct) radiation emitted from contained sources of radioactivity at MPS contributes to radiation exposure in the vicinity of the plant. For example, small amounts of ambient radiation result from low-level radioactive waste being processed and stored at the site prior to shipping and disposal. Also, the operation of the Independent Spent Fuel Storage Installation (ISFSI) which began in 2005 results in very small amounts of direct radiation at the site boundary.

The radiological dose impact on humans is based both on effluent analyses and modeling and on direct measurements of radiation and radioactivity in the environment. When MPS-related radioactivity is detected in samples that represent a plausible exposure pathway, the resulting dose from such exposure is assessed (see Sections 4 and 5). However, the operation of MPS results in releases of only small amounts of radioactivity, and, as a result of dilution in the atmosphere and ocean, even the most sensitive radioactivity measurement and analysis techniques cannot usually detect these tiny amounts of radioactivity above that which is naturally present in the environment. Therefore, radiation doses are calculated using radioactive effluent release data and computerized dose calculations that are based on conservative NRC-recommended models that tend to result in over-estimates of the resulting dose. These computerized dose calculations are performed by DNC personnel. These computer codes use the guidelines and methodology set forth by the NRC in Regulatory Guide 1.109 (Reference 7). The dose calculations are documented and described in detail in the MPS's REMODCM (Reference 8), which has been reviewed by the NRC.

It should be emphasized that because of the conservative assumptions made in the computer code calculations, the maximum hypothetical dose to an individual is considerably higher than the dose that would actually be received by a real individual.

After dose calculations are performed, the results are compared to the federal dose limits for the public. The two federal agencies that are charged with the responsibility of protecting the public from radiation and radioactivity are the NRC and the EPA.

1-13

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 The NRC, in 10 CFR 20.1301 (Reference 9) limits the levels of radiation to unrestricted areas resulting from the possession or use of radioactive materials such that they limit any individual to a dose of:

• less than. or equal to 100 mrem per year to the total body.

In addition to this dose limit, the NRC has established design objectives for nuclear plant licensees. Conformance to these guidelines ensures that nuclear power reactor effluents are maintained as far below the legal limits as is reasonably achievable.

The NRC, in 10 CFR 50 Appendix I (Reference 10) establishes design objectives for the dose to a member of the general public from radioactive material in liquid effluents released to unrestricted areas to be limited to:

• less than or equal to 3 mrem per year to the total body; and,

• less than or equal to 10 mrem per year to any organ.

The air dose due to release of noble gases in gaseous effluents is restricted to:

• less than or equal to 10 mrad per year for gamma radiation; and,

• less than or equal to 20 mrad per year for betaradiation.

The dose to a member of the general public from iodine-131, tritium, and all particulate radionuclides with half-lives greater than 8 days in gaseous effluents is limited to:

• less than or equal to 15 mrem per year to any organ.

The EPA, in 40 CFR 190.10 Subpart B (Reference 11), sets forth the environmental standards for the uranium fuel cycle. During normal operation, the annual dose to any member of the public, at or beyond the site boundary, from the entire uranium fuel cycle shall be limited to:

• less than or equal to 25 mrem per year to the total body;

• less than or equal to 75 mrem per year to the thyroid; and,

• less than or equal to 25 mrem per year to any other organ.

The summary of the 2011 radiological impact for MPS and comparison with the EPA dose limits and Appendix I guidelines is presented in Section 5 of this report.

The third stage of assessing releases to the environment is the REMP. The description and results of the REMP at MPS during 2011 is discussed in Sections 2 through 4 of this report.

1-14

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

2. PROGRAM DESCRIPTION 2.1 Samplinci Schedule and Locations The sample locations and the sample types and frequency of analysis are given in Tables 2-1 and 2-2 and Figures 2.1, 2.2 and 2.3. The program as described on Table 2-2 only lists the required samples as specified in the REMODCM. However, in order to identify the locations of the extra samples, all locations (both required and extra) are listed in Table 2-1 and shown on the figures.

2-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Table 2-1 Environmental Monitoring Program Sampling Types and Locations Location Direction &

Number* Location Name Distance From Sample Types Release Point**

1-1 On-site - Old Millstone Rd. 0.6 Mi, NNW TLD, Air Particulate, Iodine, Vegetation 2-1 On-site - Weather Shack 0.3 Mi, S TLD, Air Particulate, Iodine 3-1 On-site - Bird Sanctuary 0.3 Mi, NE TLD, Air Particulate, Iodine, Soil 4-1 On-site - Albacore Drive 1.0 Mi, N TLD, Air Particulate, Iodine, Soil 5-1 MP3 Discharge 0.1 Mi, SSE TLD 6-1 Quarry Discharge 0.3 Mi, SSE TLD 7-1 Environmental Lab Dock 0.3 Mi, SE TLD 8-1 Environmental Lab 0.3 Mi, SE TLD 9-1 Bay Point Beach 0.4 Mi, W TLD 10-1 Pleasure Beach 1.2 Mi, E TLD, Air Particulate, Iodine, Vegetation 11-1 New London Country Club 1.6 Mi, ENE TLD, Air Particulate, Iodine 12-C Fisher's Island, NY 8.0 Mi, ESE TLD 13-C Mystic, CT 11.5 Mi, ENE TLD 14-C Ledyard, CT 12.0 Mi, NE TLD, Soil 15-C Norwich, CT 14.0 Mi, N TLD, Air Particulate, Iodine 16-C Old Lyme, CT 8.8 Mi, W TLD 17-1 Site Boundary 0.5 Mi, NE Vegetation 18-X Cow 10.4 Mi, NW Milk 21-1 Goat Location #1 2.0 Mi, N Milk 24-C Goat Location #3 29.0 Mi, NNW Milk 25-1 Within 10 Miles Nearest garden Fruits & Vegetables 26-C Beyond 10 Miles Beyond 10 Miles Fruits & Vegetables 27-1 Niantic 1.7 Mi, WNW TLD, Air Particulate, Iodine 28-1 Two Tree Island 0.8 Mi, SSE Mussels, Fish***

29-1 West Jordan Cove 0.4 Mi, NNE Clams, Fish***

29-X West Jordan Cove 0.4 Mi, NNE Bottom Sediment, Fucus 30-1 Niantic Shoals 1.5 Mi, NNW Mussels 31-1 Niantic Shoals 1.8 Mi, NW Bottom Sediment, Oysters 32-1 Vicinity of Discharge < 0.1 Mi Bottom Sediment, Oysters, Lobster, Fish***, Seawater 32-X Vicinity of Discharge < 0.1 Mi Fucus 33-1 Seaside Point 1.8 Mi, ESE Bottom Sediment 33-X Seaside Point 1.8 Mi, ESE Fucus 34-1 Thames River Yacht Club 4.0 Mi, ENE Bottom Sediment 34-X Thames River Yacht club 4.0 Mi, ENE Oysters 35-1 Niantic Bay 0.3 Mi, WNW Lobster, Fish***

35-X Niantic Bay 0.3 Mi, WNW Bottom Sediment, Clams, Fucus 36-X Black Point 3.0 Mi, WSW Fucus 37-C Giant's Neck 3.5 Mi, WSW Bottom Sediment, Oysters, Seawater 37-X Giant's Neck 3.5 Mi, WSW Lobster 38-1 Waterford Shellfish Bed #1 1.0 Mi, NW Clams 39-X Jordan Cove Bar 0.8 Mi. NE Bottom Sediment, Clams

• Key: I - Indicator C - Control X - Extra - sample not required by REMODCM

• • The release points are the Site Stack for terrestrial locations and the quarry cut for aquatic locations.

• • • Flounder and another type of fish, each required to be sampled at two seperate locations.

2-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Location Direction & Distance Number* Location Name From Release Point** Sample Types 41-1 Myrock Avenue 3.2 Mi, ENE TLD 42-1 Billow Road 2.4 Mi, WSW TLD 43-1 Black Point 2.6 Mi, SW TLD 44-1 Onsite - Schoolhouse 0.1 Mi, NNE TLD 45-1 Onsite Access Road 0.5 Mi, NNW TLD 46-1 Old Lyme - Hillcrest Ave. 4.6 Mi, WSW TLD 47-1 East Lyme - W. Main St. 4.5 Mi, W TLD 48-1 East Lyme - Corey Rd. 3.4 Mi, WNW TLD 49-1 East Lyme - Society Rd. 3.6 Mi, NW TLD 50-1 East Lyme - Manwaring Rd. 2.1 Mi, W TLD 51-1 East Lyme - Smith Ave. 1.5 Mi, NW TLD 52-1 Waterford - River Rd. 1.1 Mi, NNW TLD 53-1 Waterford-Gardiners Wood Rd 1.4 Mi, NNE TLD 55-1 Waterford - Magonk Point 1.8 Mi, ESE TLD 56-1 New London - Mott Ave. 3.7 Mi, E TLD 57-1 New London - Ocean Ave. 3.6 Mi, ENE TLD 59-1 Waterford -Miner Ave. 3.4 Mi, NNE TLD 60-1 Waterford - Parkway South 4.0 Mi, N TLD 61-1 Waterford - Boston Post Rd. 4.3 Mi, NNW TLD 62-1 East Lyme - Columbus Ave. 1.9 Mi, WNW TLD 63-1 Waterford - Jordon Cove Rd. 0.8 Mi, NE TLD 64-1 Waterford - Shore Rd. 1.1 Mi, ENE TLD 65-1 Waterford - Bank St. 3.2 Mi, NE TLD 66-X NAP Parking Lot - Fit Center 0.4 Mi, NW TLD 67-X Golden Spur 4.7 Mi, NNW Bottom Sediment 69-X Pleasure Beach 0.8 Mi, E Bottom Sediment 71-1 1-MW-XFMR-03 Onsite Well Water 72-1 MW-GPI-1 Onsite Well Water 73-X Site Switchyard Fence 0.3 Mi, N TLD 74-X Ball Field Foul Pole 0.6 Mi, N TLD 75-X Waterford - Windward Way & 0.5 Mi, NE TLD Shotgun 76-X ISFSI-1 Up-gradient of ISFSI Well Water 77-X ISFSI-2A Down-gradient of ISFSI Well Water 78-X ISFSI-3 Down-gradient of ISFS1 Well Water 79-1 M3-MW-1 Onsite Well Water 80-1 S12-MW-2 Onsite Well Water 81-1 S2-MW-1 Onsite Well Water 82-1 MW-GPI-2 Onsite Well Water 83-X MW-GPI-3 Onsite Well Water 84-X MW-GPI-4 Onsite Well Water 85-X MW-GPI-5 Onsite Well Water 86-X MW-GPI-6 Onsite Well Water 88-1 DEP Dock Onsite Oysters 90-X Thames River 4 Mi, E Fucus 91 -X MW-GPI-8 Onsite Well Water 92-X MW-GPI-9 Onsite Well Water RI-X Ram Island Oysters

• Key: I - Indicator C - Control X - Extra - sample not required by the REMODCM

• • The release points are the Site Stack for terrestrial locations and the quarry cut for aquatic locations.

2-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Table 2-2 Required Sampling Frequency & Type of Analysis Exposure Pathway No. of Sampling & Collection Type of Analysis and/or Sample Locations Frequency

1. Gamma Dose - 40a Quarterly Gamma Dose - Quarterly Environmental TLD

2. Airborne Particulate 8 Continuous sampler - weekly Gross Beta - Weekly filter change Gamma Spectrum - Quarterly on composite (by location), and on individual sample if gross beta is greater than 10 times the mean of the weekly control station's gross beta results

3. Airborne Iodine 8 Continuous sampler - weekly 1-131 - Weekly canister change

4. Vegetation 5 One sample near middle and Gamma Isotopic on each sample one near end of growing season

5. Milk 2 Semimonthly when animals are Gamma Isotopic and 1-131 on each on pasture; monthly at other sample; Sr-89 and Sr-90 on times. quarterly composite 5a. Pasture Grass 2 Sample as necessary to Gamma Isotopic and 1-131 on each substitute for unavailable milk sample

6. Sea Water 2 Continuous sampler with a Gamma Isotopic and Tritium on monthly collection at indicator each sample.

location. Quarterly at control location - Composite of 6 weekly grab samples.

6a. Well Water 6 Semiannual Gamma Isotopic and Tritium on each sample

7. Bottom Sediment 5 Semiannual Gamma Isotopic on each sample 7a. Soil 3 Annually Gamma Isotopic on each sample

8. Fin Fish - Flounder 2 Quarterly Gamma Isotopic on each sample and one other type of edible fin fish

9. Mussels 2 Quarterly Gamma Isotopic on each sample (edible portion)

10. Oysters 4 Quarterly Gamma Isotopic on each sample (edible portion)

11. Clams 2 Quarterly Gamma Isotopic on each sample (edible portion)

12. Lobster 2 Quarterly Gamma Isotopic on each sample (edible portion) I (a) Two or more TLDs or TLD with two or more elements per location.

2-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 r

-i At L

I*

2-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Figure 2.2 Millstone Power Station Sampling Locations (Within 2 miles) 53 5152-f f F7 3 75 2-6

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Figure 2.3 Millstone Power Station Sampling Wells 2-7

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 2.2 Samples Collected During Report Period The following table summarizes the number of samples of each type collected and analyzed during 2011:

Number of Number of Technical Technical Specification Specification Number of Sample Type Required Samples Required Samples Extra Samples Analyzed Analyzed Gamma Exposure 160 1581 16 (Environmental TLD)

Air Particulates 416 4121 0 Air Iodine 416 412' 0 Soil 3 3 0 Cow and Goat Milk 38 52 18 3

Pasture Grass/Feed Variable 33 5 Fruit and Vegetables 4 4 3 Broad Leaf Vegetation 6 6 0 Well Water 12 12 47 Sea Water 16 16 0 Bottom Sediment 10 10 9 Aquatic Flora 0 0 24 Fish 16 104 0 Mussels 8 44 0 Oysters 16 16 9 Clams 8 8 8 Lobster 8 8 3 Total All Types 1,137 1,117 142 1 See notes at end of Section 3 for details on loss of some TLDs and air samples.

2 Pasture grass or feed sampled as necessary to substitute for unavailable milk.

3 Depends upon availability of milk samples 4 Due to sample unavailability, not all required fish and shellfish samples could be obtained 2-8

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

3. RADIOCHEMICAL RESULTS 3.1 Summary Table In accordance with the REMODCM,Section I.F.1, a summary table of the radiochemical results has been prepared and is presented on the following pages. The mean and range recorded are based only upon detectable measurements. There were no non-routine measurements in 2011.

A more detailed analysis of the data is given in Section 4.0 where a discussion of the variations in the data explains many aspects that are not evident in the Summary Table because of the basic limitation of data summaries. The data summaries include the extra ("X") samples collected throughout the year. These samples are taken to enhance the monitoring program, or are the results of special studies.

3-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Millstone Power Station Dockets 50-245, 50-336 & 50-423 Medium or Indicator Control Pathway Analysis Total LLD* Locations Location with Highest Mean Locations Sampled Type Number Mean I Distance Mean Mean (Units) (Range) NumberI Direction (Range) Range Direct Gamma 174 - 7.7 8 0.3 Mi. 10.8 7.7 Radiation Dose (4.5- 11.0) SE (10.4 - 11.0) (5.7-9.4)

TLD (uRlhr)

Air Iodine 1-131 412 70 79.8 2 0.3 Mi. 105 60.2 3

(le-3 pCi/m ) (51.2- 105) S (57.6 - 62.7)

Air Particulate GR-B 412 10 15.5 27 1.7 Mi. 15.7 15.2 (le-3 pCi/m 3 ) (4.8-31.5) WNW (5.0-27.8) (4.9-30.8)

GAMMA 48 BE-7 - 126 4 1.0 Mi. 142 128 (84 -225) N (96- 225) (90- 287)

Other <LLD - <LLD Gammas Soil GAMMA 3 (pCi/g dry) K-40 - 15.3 3 0.03 Mi. 16.0 14.2 (14.5 - 16.0) NE 1 sample 1 sample CS-137 0.18 0.373 14 12.0 Mi. 0.677 0.677 (0.288 - 0.458) NE 1 sample 1 sample Other - <LLD - <LLD Gammas Milk GAMMA 23 (pCi//) K-40 920 24 29.0 Mi. 1360 1360 (686 - 1230) NNW 1 sample 1 sample Other <LLD - <LLD Gammas Pasture GAMMA 38 GrasslHay BE-7 2.64 18 10.4 Mi. 3.17 2.80 (pCi/g wet) (0.294 - 6.92) NW 1 sample (0.622 - 6.58)

K-40 - 7.52 18 10.4 Mi. 8.77 7.49 (3.65 - 13.9) NW (7.33 - 10.2) (2.75 - 21.6)

CS-137 0.08 0.021 (1/21) 24 29.0 Mi. 0.048 0.048 NNW (0.030 - 0.059) (0.030 - 0.059)

Other - <LLD <LLD Gammas Well Water H-3 59 <LLD (pCO)

GAMMA 59 K-40 61.9 71 Onsite 72.1 (56.6 - 72.1) 1 sample Other <LLD <LLD Gammas 3-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Millstone Power Station Dockets 50-245, 50-336 & 50-423 Medium or Indicator Control Pathway Analysis Total LLD* Locations Location with Highest Mean Locations Sampled Type Number Mean Distance Mean Mean (Units) (Range) Number Direction (Range) Range Fruits & GAMMA 7 Vegetables BE-7 0.521 25 Within 10 Miles 0.521 <LLD (pCi/g wet) (0.280 - 0.832) (0.28 - 0.832)

K-40 2.39 26 Beyond 10 miles 2.76 2.76 (0.987 - 4.38) (0.929 - 5.90) (0.929 - 5.90)

Th-232 decay chain* - 0.040 (1/7) 25 Within 10 Miles 0.040 <LLD

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228.

Other - <LLD - <LLD Gammas Broad Leaf GAMMA 6 Vegetation BE-7 1.98 17 0.5 Mi. 2.58 (pCi/g wet) (0.905 - 5.76) NE (1.15 - 5.76)

K-40 - 3.50 10 1.2 Mi. 3.76 (1.92 - 5.70) E (2.63 - 5.34)

CS-137 0.08 0.061 17 0.5 Mi. 0.061 (0.045- 0.070) NE (0.045 - 0.070)

Other - <LLD - <LLD Gammas Sea Water H-3 16 - 665 32 < 0.1 Mi 665 <LLD (pCi/I) (214-2260) (214-2260)

GAMMA 16 K-40 - 264 32 < 0.1 Mi 264 258 (211 -310) (211 -310) (213-296)

Other - <LLD - <LLD Gammas Bottom GAMMA 19 Sediment K-40 - 15.7 39 0.8 Mi. 18.5 14.2 (pCi/gdry) (6.27 - 18.5) NE 1 sample (13.9 - 14.4)

CS-137 0.18 0.123 39 0.8 Mi. 0.123 <LLD 1 sample NE 1 sample Other - <LLD <LLD Gammas Flora GAMMA 24 (pCi/g wet) BE-7 0.169 90 4.0 Mi. 0.342 0.342 (0.113 - 0.236) E 1 sample 1 sample K-40 - 7.11 32 < 0.1 Mi 7.85 7.38 (5.36 - 8.70) (7.43- 8.70) (6.57 - 8.26) 1-131 0.06 0.055 32 < 0.1 Mi 0.072 <LLD (0.043 - 0.072) 1 sample Th-232 decay chain* - 0.077 33 1.8 Mi. 0.110 0.051

(.052 - 0.110) ESE 1 sample (0.048 - 0.053)

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228.

Other <LLD <LLD Gammas 3-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAM

SUMMARY

Millstone Power Station Dockets 50-245, 50-336 & 50-423 Medium or Indicator Control Pathway Analysis Total LLD* Locations Location with Highest Mean Locations Sampled Type Number Mean Distance I Mean Mean (Units) (Range) Number Direction I (Range) Range Fish - GAMMA Flounder K-40 4 - 4.3 32 < 0.1 Mi 4.7 (pCi/g wet) (3.7-4.8) (4.5-4.8)

Other - <LLD - <LLD Gammas Fish - Other GAMMA (pCi/g wet) K-40 6 - 3.8 35 0.3 Mi. 4.1 (3.3 -4.6) WNW (3.8 -4.6)

Other - <LLD <LLD Gammas Mussels GAMMA (pCi/g wet) K-40 4 - 2.4 30 1.5 Mi. 2.4 (2.3- 2.5) NNW (2.3 - 2.5)

Other - <LLD - <LLD Gammas Oysters GAMMA (pCi/g wet) K-40 23 - 1.8 31 1.8 Mi. 2.1 1.5 (1.1 -2.7) NW (2.0-2.2) (1.3-1.6)

AG-110M - 0.1 32 < 0.1 Mi 0.1 <LLD (0.1 -0.1) (0.1 -0.1)

Other - <LLD - <LLD Gammas Clams GAMMA (pCi/g wet) K-40 16 - 2.0 39 0.8 Mi. 2.1 (1.4 -2.8) NE (2.0-2.4)

Other - <LLD <LLD Gammas LoDster GAMMA (pCi/g wet) K-40 11 2.4 37 3.5 Mi. 2.6 2.6 (1.4 -2.8) WSW (1.8 - 3.0) (1.8/3.0)

Other <LLD <LLD Gammas 3-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 NOTES FOR

SUMMARY

TABLE For gamma measurements the Minimum Detectable Level (MDL) - the Lower Limit of Detection (LLD) / 2.33. For all others, MDL = 2 x (the standard deviation of the background). These MDLs are based on the absence of large amounts of interfering activity (excluding naturally occurring radionuclides). Deviations by factors of 3 to 4 can occur.

The LLD at a confidence level of 95% is the smallest concentration of radioactive material in a sample that will be detected with a 5% probability of falsely concluding that a blank observation represents a "real" signal.

For a particular measurement system (which may include radiochemical separation):

LLD = 4.66 Sb E

• V

• 2.22

• Y

• exp (-,IAt) where, LLD is the lower limit of detection as defined above (as pCi per unit mass or volume)

Sb is the standard deviation of the background counting rate or of the counting rate of a blank sample as appropriate (as counts per minute)

E is the counting efficiency (as counts per transformation)

V is the sample size (in units of mass or volume) 2.22 is the number of transformation per minute per picoCurie Y is the fractional radiochemical yield (when applicable)

A is the radioactive decay constant for the particular radionuclide Xt is the elapsed time between sample collection (or end of the sample collection period) and time of counting The LLD is defined as "a priori" (before the fact) limit representing the capability of a measurement system and not an "a posteriori" (after the fact) limit for a particular measurement.

Analyses was performed in such a manner that the stated LLDs were achieved under routine conditions. Occasionally background fluctuations, unavoidably small sample sizes, the presence of interfering nuclides, or other uncontrollable circumstances may have rendered these a priori LLDs unachievable. In such cases, the contributing factors are identified and described in this report. As shown in the equation above, for composite samples taken over a period of time, the LLD is decayed to the end of the sample period.

The listed 1-131 LLD for all the vegetation samples is for leafy vegetables.

The 1-131, Ba-140 and La-140 LLDs for the water samples are from end of sample period.

3-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 3.2 Data Tables The data reported in this section are strictly counting statistics. The reported error is two times the standard deviation (2a) of the net activity. Unless otherwise noted, the overall error (counting, sample size, chemistry, errors, etc.) is estimated to be 2 to 5 times that listed.

Results are considered positive when the measured value exceeds 1.5 times the listed 20 error (i.e., the measured value exceeds 3a). Any errors listed as zero are the artifact that there were no background counts in the area of the peak for these nuclides.

Because of counting statistics, negative values, zeros and numbers below the Minimum Detectable Level (MDL) are statistically valid pieces of data. For the purposes of this report, in order to indicate any background biases, all the valid data are presented. This practice was recommended by Health and Safety Laboratory (HASL) ("Reporting of Analytical Results from HASL," letter by Leo B. Higginbotham), NUREG 0475 and NUREG/CR-4007 (Sept.

1984). In instances where zeros are listed after significant digits, this is an artifact of the computer data-handling program.

Data are given according to sample type as indicated below.

1. Gamma Exposure Rate

2. Air Particulates, Gross Beta Radioactivity

3. Air Particulates, Weekly 1-131

4. Air Particulates, Quantitative Gamma Spectra

5. Air Particulates, Quarterly Strontium*

6. Soil

7. Milk - Dairy Farms

8. Milk - Goat Farms

9. Pasture Grass

10. Well Water

11. Reservoir Water or Deer Meat*

12. Fruits & Vegetables

13. Broad Leaf Vegetation

14. Seawater

15. Bottom Sediment

16. Aquatic Flora

17. Fin Fish

18. Mussels

19. Oysters

20. Clams

21. Scallops*

22. Lobster

• This type of sampling or analysis was not performed.

3-6

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 1 QUARTERLY GAMMA EXPOSURE RATE (uR/hr)*

LOCATIONS PERIOD 1 2 3(+--) 4 5(*--) 6(+--) 7 8 9 10 11

(+1-) (+/-) (+--) (*1-) (+/-) (+1-) (+1-)

(+1-)

1Q 7.9 0.2 9.7 0.3 7.4 0.4 7.4 0.2 8.4 0.4 8.0 0.3 5.1 0.23 10.4 0.3 8.4 0.3 10.7 0.3 6.6 0.2 2Q 8.0 0.4 9.6 0.5 7.6 0.5 7.8 0.4 9.2 0.4 7.8 0.4 4.5 0.27 11.0 0.5 9.0 0.5 10.7 0.6 6.6 0.3 8.1 0.2 9.5 0.3 7.3 0.3 7.5 0.3 8.8 0.4 7.7 0.3 See Note A 10.9 0.3 8.6 0.3 10.7 0.5 6.4 0.4 3Q 4Q 8.4 0.2 10.5 0.3 7.4 0.4 8.1 0.3 9.3 0.4 7.8 0.2 6.2 0.35 10.8 0.3 9.2 0.2 11.0 0.3 6.6 0.2 PERIOD 12C 13C 14C 15C 16C 27 41 42 43 44 45

(+--) (+1-) (+1-) (+--) (+--) (*/-)

(+6-) (+/-) (+--) (+1-)

1Q 7.2 0.4 8.5 0.4 7.9 0.6 7.5 0.2 5.7 0.2 8.9 0.4 6.8 0.3 6.6 0.3 6.4 0.3 7.5 0.3 7.0 0.3 2Q 7.0 0.3 8.8 0.5 9.2 0.4 7.6 0.4 6.2 0.3 8.1 0.4 6.6 0.3 7.3 0.4 6.8 0.3 8.5 0.5 7.2 0.4 3Q 7.4 0.2 8.5 0.4 8.7 0.3 7.4 0.2 6.2 0.3 8.0 0.2 6.8 0.2 7.3 0.3 6.5 0.2 7.8 0.4 7.5 0.4 4Q See Note B 8.8 0.3 9.4 0.3 7.8 0.3 6.2 0.2 8.3 0.3 6.7 0.4 7.3 0.3 6.6 0.2 8.0 0.2 6.9 0.3 PERIOD 46 47 48 49 50 51 52 53 55 56 57

(+--) (+/-) (+--) (+1-) (+--) (+--) (+1-)

(+/-) (+/-) (+/-) (+1-)

1Q 8.1 0.3 7.2 0.3 8.7 0.3 6.1 0.2 7.2 0.3 6.3 0.3 7.2 0.3 7.0 0.2 7.5 0.2 7.2 0.4 7.1 0.3 2Q 8.1 0.6 7.2 0.4 9.1 0.4 6.9 0.3 7.6 0.3 6.4 0.4 7.2 0.3 7.2 0.4 7.3 0.6 6.9 0.3 6.9 0.4 3Q 8.1 0.5 8.2 0.2 9.2 0.3 8.0 0.7 8.0 0.2 6.6 0.3 7.0 0.3 7.2 0.3 7.5 0.4 7.1 0.3 7.3 0.2 4Q 8.2 0.2 7.7 0.2 9.3 0.4 6.8 0.2 7.6 0.3 6.1 0.2 7.0 0.2 7.3 0.2 7.4 0.2 6.9 0.2 7.3 0.4 PERIOD 59 60 61 62 63 64 65 66X 73X 74X 75X

(+--) (+/-) (+---------) (*1-) (+/-) (+--) (+1-) (+--) (+1-) (+--) (+/-)

1Q 7.3 0.5 6.4 0.2 6.7 0.4 7.6 0.3 8.7 0.3 7.1 0.3 8.1 0.3 7.0 0.4 9.1 0.3 7.6 0.2 6.5 0.4 2Q 7.3 0.4 6.5 0.4 7.0 0.6 7.7 0.4 7.6 0.4 7.5 0.4 8.0 0.5 6.9 0.4 8.8 0.4 7.5 0.3 6.7 38.0 3Q 7.7 0.3 7.7 0.7 7.2 0.3 8.1 0.2 8.6 0.4 7.3 0.3 8.3 0.4 7.0 0.3 9.2 0.4 7.3 0.2 6.6 0.3 4Q 7.8 0.2 6.6 0.2 7.1 0.2 7.6 0.4 8.2 0.3 7.3 0.2 8.3 0.2 6.7 0.2 9.2 0.2 7.3 0.2 6.9 0.3

• READINGS ARE THE AVERAGE OF MULTI CASO4TM PHOSPHOR ELEMENTS WITHIN ONE PANASONIC TLD BADGE ERRORS ARE 1 SIGMA AND INCLUDE COUNTING, TRANSIT, READER AND FADE UNCERTAINTIES 3-7

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 2 AIR PARTICULATES GROSS BETA RADIOACTIVITY (pCi/md)

LOCATIONS PERIOD ENDING 01 02 03 04 10 11 15C 27

(+/-) -(-- -- --- ------

01/04/11 0.023 0.004 0.025 0.004 0.026 0.005 0.028 0.004 0.024 0.004 0.025 0.004 0.022 0.004 0.026 0.005 01/11/11 0.018 0.004 0.019 0.004 0.019 0.005 0.017 0.004 0.016 0.004 0.018 0.004 0.016 0.004 0.018 0.004 01/18/11 0.012 0.003 0.013 0.003 0.014 0.004 0.010 0.003 0.013 0.003 0.013 0.003 0.012 0.003 0.014 0.003 01/25/11 0.017 0.004 0.019 0.004 0.017 0.004 0.019 0.004 0.017 0.004 0.012 0.003 0.015 0.004 0.019 0.004 02/01/11 0.024 0.004 0.025 0.004 0.021 0.004 0.024 0.004 0.021 0.004 0.022 0.004 0.024 0.004 0.023 0.004 02/08/11 0.016 0.004 0.011 0.004 0.014 0.004 0.020 0.004 0.015 0.004 0.013 0.004 0.017 0.004 0.016 0.004 02/15/11 0.017 0.003 0.016 0.003 0.020 0.004 0.014 0.003 0.015 0.003 0.021 0.004 0.018 0.003 0.017 0.003 02/22/11 0.014 0.004 0.016 0.004 0.015 0.004 0.012 0.004 0.012 0.004 0.015 0.004 0.016 0.004 0.018 0.004 03/01/11 0.015 0.004 0.013 0.003 0.018 0.004 0.014 0.003 0.015 0.003 0.014 0.004 0.013 0.003 0.018 0.004 03/08/11 0.015 0.003 0.015 0.003 0.016 0.003 0.015 0.003 0.017 0.003 0.015 0.003 0.016 0.003 0.017 0.003 03/15/11 0.012 0.004 0.011 0.003 0.009 0.004 0.012 0.004 0.013 0.004 0.013 0.004 0.014 0.004 0.013 0.004 03/22/11 0.010 0.003 0.012 0.003 0.009 0.003 0.011 0.003 0.011 0.003 0.013 0.003 0.011 0.003 0.009 0.003 03/29/11 0.030 0.004 0.028 0.004 0.032 0.005 .0.028 0.004 0.031 0.004 0.031 0.005 0.031 0.004 0.028 0.005 04/05/11 0.025 0.004 0.021 0.004 0.023 0.004 0.021 0.003 0.021 0.003 0.025 0.004 0.022 0.004 0.021 0.004 04/12/11 0.022 0.004 0.017 0.004 0.024 0.005 0.025 0.004 0.023 0.004 0.024 0.004 0.021 0.004 0.023 0.005 04/19/11 0.013 0.004 0.020 0.004 0.014 0.004 0.016 0.004 0.015 0.004 0.015 0.004 0.015 0.004 0.013 0.004 04/26/11 0.017 0.004 0.016 0.004 0.017 0.004 0.016 0.004 0.017 0.004 0.014 0.004 0.017 0.004 0.013 0.004 05/03/11 0.005 0.003 0.006 0.003 0.004 0.003 0.006 0.003 0.006 0.003 0.004 0.003 0.005 0.003 0.005 0.003 05/10/11 0.014 0.004 0.014 0.004 0.011 0.003 0.011 0.003 0.014 0.004 0.012 0.004 0.012 0.003 0.013 0.003 05/17/11 0.006 0.002 0.007 0.003 0.006 0.002 0.006 0.002 0.005 0.002 0.006 0.002 0.005 0.002 0.006 0.002 05/24/11 0.003 0.003 0.006 0.004 0.005 0.003 0.005 0.003 0.008 0.004 0.006 0.004 0.008 0.003 0.005 0.003 05/31/11 0.014 0.003 0.017 0.003 0.016 0.003 0.015 0.003 0.018 0.003 0.015 0.003 0.016 0.003 0.016 0.003 06/07/11 0.012 0.003 0.013 0.003 0.011 0.003 0.010 0.003 0.012 0.003 0.012 0.003 0.010 0.003 0.012 0.003 06/14/11 0.012 0.003 0.011 0.003 0.011 0.003 0.014 0.004 0.015 0.003 0.015 0.004 0.013 0.003 0.014 0.003 06/21/11 0.013 0.003 0.011 0.003 0.012 0.003 0.013 0.003 0.009 0.003 0.015 0.003 0.010 0.003 0.013 0.003 06/28/11 0.008 0.003 0.008 0.003 0.009 0.003 0.007 0.003 0.008 0.003 0.008 0.003 0.008 0.003 0.009 0.003 SAMPLE DATES MAY VARY BY A FEW DAYS - See Note C 3-8

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 2 AIR PARTICULATES GROSS BETA RADIOACTIVITY (pCi/m3)

LOCATIONS PERIOD ENDING 01 02 03 04 10 11 15SC 27

(+/-) -- -- (--) -

--- ----- ---)ý 07/05/11 0.019 0.004 0.014 0.004 0.017 0.004 0.014 0.004 0.018 0.004 0.016 0.004 0.016 0.004 0.016 0.004 07/12/111 0.019 0.004 0.020 0.005 0.015 0.004 0.016 0.004 0.019 0.005 0.019 0.005 0.019 0.004 0.016 0.004 07/19/11 0.017 0.004 0.018 0.004 0.014 0.003 0.013 0.003 0.013 0.003 0.013 0.004 0.015 0.003 0.014 0.003 07/26/11 0.020 0.004 0.017 0.004 0.018 0.004 0.021 0.004 0.021 0.004 0.019 0.004 0.018 0.004 0.020 0.004 08/02/11 0.013 0.003 0.014 0.003 0.013 0.003 0.010 0.003 0.012 0.003 0.014 0.003 0.013 0.003 0.014 0.003 08/09/11 0.015 0.004 0.014 0.004 0.015 0.004 0.014 0.004 0.015 0.004 0.012 0.003 0.017 0.004 0.015 0.004 08/16/11 0.014 0.003 0.015 0.003 0.014 0.003 0.017 0.003 0.015 0.003 0.011 0.003 0.013 0.003 0.012 0.003 08/23/11 0.015 0.003 0.014 0.003 0.013 0.003 0.017 0.003 0.014 0.003 0.015 0.003 0.014 0.003 0.013 0.003 08/30/11 0.012 0.004 0.015 0.004 0.013 0.004 0.016 0.005 0.017 0.005 0.013 0.004 0.012 0.003 0.018 0.004 09/06/11 0.014 0.004 0.017 0.004 0.011 0.004 See Note D 0.015 0.005 0.015 0.005 0.014 0.003 0.013 0.003 09/13/11 0.011 0.003 0.013 0.003 0.013 0.004 0.012 0.003 0.010 0.003 0.012 0.003 0.016 0.004 09/20/11 0.022 0.004 0.017 0.003 0.029 0.004 0.017 0.004 0.019 0.003 0.019 0.004 0.025 0.004 09/27/11 0.009 0.003 0.009 0.003 0.012 0.004 0.011 0.004 0.011 0.003 0.010 0.003 0.010 0.003 10/04/11 0.017 0.003 0.015 0.003 0.020 0.004 0.022 0.004 0.016 0.004 0.015 0.003 0.015 0.003 0.017 0.004 10/11/11 0.023 0.004 0.025 0.004 0.023 0.004 0.024 0.004 0.024 0.004 0.031 0.004 0.024 0.004 0.024 0.004 10/18/11 0.013 0.003 0.012 0.003 0.014 0.003 0.012 0.003 0.009 0.003 0.013 0.003 0.010 0.003 0.013 0.003 10/25/11 0.011 0.003 0.014 0.003 0.013 0.004 0.013 0.004 0.013 0.004 0.009 0.003 0.011 0.003 0.014 0.004 11/01/11 0.011 0.003 0.011 0.003 0.011 0.003 0.009 0.003 0.013 0.003 0.011 0.003 0.006 0.003 0.008 0.003 11/08/11 0.013 0.003 0.011 0.003 0.013 0.003 0.016 0.003 0.012 0.003 0.014 0.003 0.016 0.003 0.016 0.003 11/15/11 0.020 0.004 0.022 0.004 0.021 0.004 0.024 0.004 0.017 0.003 0.020 0.004 0.024 0.004 0.021 0.004 11/22/11 0.016 0.003 0.016 0.003 0.016 0.003 0.015 0.004 0.014 0.003 0.015 0.003 0.015 0.003 0.014 0.003 11/29/11 0.016 0.003 0.016 0.003 0.015 0.003 0.017 0.003 0.015 0.003 0.017 0.003 0.015 0.003 0.011 0.003 12/06/11 0.015 0.003 0.012 0.003 0.014 0.003 0.010 0.003 0.015 0.003 0.011 0.003 0.013 0.003 0.011 0.003 12/13/11 0.013 0.003 0.017 0.003 0.018 0.003 0.017 0.003 0.020 0.003 0.019 0.003 0.017 0.003 0.016 0.003 12/20/11 0.021 0.004 0.024 0.003 0.020 0.004 0.021 0.004 0.021 0.003 0.021 0.003 0.023 0.004 0.023 0.004 12/27/111 0.014 0.003 0.016 0.003 0.014 0.003 0.013 0.003 0.016 0.003 0.013 0.003 0.014 0.003 0.017 0.004 01/03/12 0.016 0.003 0.014 0.003 0.019 0.004 0.018 0.004 0.017 0.004 0.016 0.003 0.014 0.003 0.019 0.004 SAMPLE DATES MAY VARY BY A FEW DAYS - See Note C 3-9

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 3 AIRBORNE IODINE (pCi/ms)

LOCATION PERIOD ENDING* 01 02 03 04 10 11 15C 27

(+-)-CF

- --- (+1-) (+/-) (+/-) (+/-) ----- --- (+1-) (+1-)

01/04/11 -0.023 0.032 -0.023 0.031 -0.025 0.035 -0.021 0.029 0.004 0.030 0.005 0.033 0.005 0.034 0.005 0.036 01/11/11 -0.006 0.017 -0.006 0.018 -0.007 0.019 -0.006 0.017 0.003 0.020 0.004 0.020 0.004 0.021 0.004 0.022 01/18/11 -0.002 0.010 -0.002 0.009 -0.002 0.010 -0.002 0.009 0.005 0.014 0.005 0.015 0.006 0.015 0.006 0.016 01/25/11 -0.005 0.027 -0.005 0.026 -0.005 0.028 -0.005 0.025 -0.007 0.022 -0.008 0.023 -0.007 0.023 -0.008 0.024 02/01/11 -0.022 0.021 -0.021 0.020 -0.025 0.023 -0.021 0.019 -0.005 0.030 -0.005 0.032 -0.005 0.033 -0.005 0.035 02/08/11 0.005 0.032 0.005 0.031 0.006 0.035 0.005 0.030 0.002 0.017 0.002 0.018 0.003 0.024 0.003 0.026 02/15/11 -0.010 0.024 -0.010 0.023 -0.011 0.026 -0.009 0.022 0.002 0.036 0.002 0.038 0.002 0.037 0.002 0.04 1 02/22/111 -0.007 0.014 -0.007 0.014 -0.007 0.015 -0.006 0.013 -0.004 0.017 -0.005 0.018 -0.004 0.018 -0.005 0.020 03/01/11 0.029 0.035 0.028 0.034 0.028 0.036 0.027 0.034 -0.007 0.021 -0.007 0.021 -0.007 0.021 -0.008 0.023 03/08/11 0.012 0.030 0.011 0.029 0.013 0.033 0.011 0.029 0.013 0.031 0.013 0.033 0.013 0.031 0.014 0.035 03/15/11 0.002 0.017 0.002 0.016 0.002 0.018 0.002 0.016 0.014 0.028 0.015 0.030 0.014 0.029 0.016 0.032 03/22/11 0.022 0.029 0.022 0.029 0.024 0.031 0.021 0.028 0.009 0.023 0.009 0.024 0.009 0.023 0.010 0.026 03/29/11 0.061 0.025 0.048 0.039 0.058 0.027 0.056 0.029 0.039 0.026 0.051 0.026 0.063 0.028 0.088 0.041 04/05/11 0.104 0.038 0.105 0.046 0.079 0.049 0.097 0.033 0.069 0.039 0.104 0.040 0.058 0.032 0.085 0.034 04/12/11 0.042 0.029 0.030 0.025 0.053 0.036 0.067 0.037 0.046 0.026 0.046 0.043 0.008 0.023 0.094 0.034 04/19/11 0.006 0.019 -0.003 0.017 -0.002 0.025 0.008 0.015 0.022 0.015 0.024 0.022 0.011 0.019 0.004 0.014 04/26/11 0.007 0.040 0.007 0.040 0.006 0.041 0.007 0.039 -0.013 0.042 -0.014 0.044 -0.013 0.042 -0.012 0.039 05/03/11 -0.002 0.036 -0.002 0.036 -0.002 0.033 -0.002 0.035 -0.016 0.030 -0.017 0.030 -0.016 0.029 -0.015 0.027 05/10/11 -0.004 0.030 -0.004 0.030 -0.004 0.027 -0.004 0.030 0.024 0.030 0.025 0.031 0.023 0.029 0.022 0.027 05/17/11 0.013 0.033 0.013 0.033 0.012 0.030 0.013 0.033 0.002 0.037 0.002 0.039 0.002 0.037 0.002 0.035 05/24/11 -0.030 0.041 -0.030 0.041 -0.028 0.039 -0.031 0.042 -0.001 0.034 -0.001 0.036 -0.001 0.034 -0.001 0.032 05/31/11 0.028 0.035 0.029 0.035 0.026 0.032 0.028 0.034 0.007 0.027 0.007 0.029 0.006 0.027 0.006 0.026 06/07/11 -0.038 0.035 -0.038 0.034 -0.035 0.032 -0.037 0.034 -0.026 0.047 -0.027 0.048 -0.025 0.045 -0.024 0.044 06/14/11 0.013 0.032 0.013 0.032 0.012 0.029 0.013 0.032 0.017 0.035 0.018 0.038 0.017 0.034 0.016 0.033 06/21/111 0.011 0.031 0.011 0.031 0.010 0.028 0.011 0.031 0.012 0.032 0.012 0.034 0.011 0.030 0.011 0.030 06/28/11 0.004 0.028 0.004 0.028 0.004 0.025 0.004 0.028 -0.008 0.033 -0.009 0.035 -0.008 0.031 -0.007 0.031

• Results during periods from 3/29/11 to 4/12/11 are positive due to radioactivity from Fukushima, Japan. See discussion in Section 4.3.

SAMPLE DATES MAY VARY BY AFEW DAYS -See Note C 3-10

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 3 AIRBORNE IODINE (pUime)

LOCATION PERIOD ENDING -- -- -- --- 02 03 04 10 ---- 11 ----- ---- 15,C 27 07/05/11 -0.004 0.038 -0.004 0.038 -0.003 0.033 -0.004 0.037 -0.012 0.040 -0.013 0.042 -0.011 0.038 -0.011 0.038 07/12/11 -0.002 0.035 -0.002 0.036 -0.002 0.032 -0.002 0.035 -0.040 0.052 -0.038 0.049 -0.030 0.047 -0.030 0.047 07/19/11 -0.004 0.022 -0.004 0.022 -0.003 0.020 -0.004 0.022 0.002 0.032 0.002 0.034 0.001 0.030 0.001 0.030 07/26/11 0.018 0.028 0.018 0.028 0.016 0.026 0.018 0.028 0.005 0.024 0.006 0.025 0.005 0.022 0.005 0.022 08/02/11 0.021 0.022 0.021 0.022 0.019 0.021 0.021 0.022 -0.008 0.027 -0.007 0.023 -0.007 0.025 -0.007 0.025 08/09/11 -0.004 0.025 -0.005 0.025 -0.004 0.023 -0.004 0.025 -0.011 0.036 -0.009 0.030 -0.010 0.033 -0.010 0.033 08/16/11 -0.003 0.020 -0.003 0.020 -0.002 0.018 -0.001 0.009 0.007 0.022 0.005 0.018 0.006 0.020 0.003 0.009 08/23/11 0.008 0.040 0.008 0.040 0.007 0.035 0.008 0.039 0.002 0.039 0.001 0.033 0.002 0.038 0.002 0.037 08/30/11 -0.002 0.015 -0.002 0.015 -0.002 0.016 -0.002 0.011 -0.003 0.018 -0.002 0.015 -0.002 0.013 -0.002 0.013 09/06/11 0.005 0.011 0.005 0.011 0.005 0.011 See Note D 0.003 0.006 -0.007 0.010 -0.005 0.007 -0.003 0.004 09/13/11 -0.001 0.006 -0.001 0.006 -0.001 0.007 -0.007 0.010 -0.001 0.005 -0.007 0.009 -0.006 0.009 09/20/11 0.032 0.030 0.032 0.030 0.034 0.032 0.029 0.036 0.023 0.029 0.027 0.032 0.027 0.033 09/27/11 -0.001 0.008 -0.001 0.009 -0.001 0.009 0.000 0.005 -0.001 0.011 -0.002 0.012 -0.001 0.005 10/04/11 0.000 0.013 0.000 0.013 0.000 0.014 0.000 0.006 -0.002 0.007 -0.002 0.006 -0.002 0.007 -0.001 0.004 10/11/11 -0.002 0.020 -0.002 0.021 -0.003 0.024 -0.002 0.023 -0.006 0.025 -0.005 0.020 -0.005 0.022 -0.006 0.023 10/18/11 0.000 0.021 0.000 0.020 0.001 0.025 0.000 0.023 0.026 0.032 0.021 0.026 0.023 0.028 0.024 0.030 10/25/11 -0.001 0.011 -0.001 0.010 -0.001 0.013 -0.001 0.012 0.005 0.016 0.004 0.013 0.005 0.014 0.005 0.015 11/01/11 -0.011 0.013 -0.009 0.012 -0.011 0.013 -0.012 0.015 0.005 0.016 0.005 0.016 0.005 0.017 0.006 0.018 11/08/11 0.010 0.029 0.008 0.026 0.009 0.029 0.011 0.032 -0.004 0.033 -0.003 0.032 -0.004 0.035 -0.004 0.038 11/15/11 -0.005 0.027 -0.005 0.026 -0.005 0.026 -0.006 0.030 0.005 0.027 0.005 0.028 0.005 0.029 0.005 0.031 11/22/11 -0.019 0.028 -0.018 0.027 -0.019 0.029 -0.022 0.032 0.000 0.018 0.000 0.018 0.000 0.019 0.000 0.020 11/29/11 0.005 0.024 0.005 0.023 0.005 0.024 0.005 0.027 0.000 0.024 0.001 0.025 0.001 0.026 0.001 0.028 12/06/11 0.000 0.015 0.000 0.014 0.000 0.015 0.000 0.017 -0.002 0.019 -0.003 0.019 -0.003 0.020 -0.003 0.021 12/13/11 -0.009 0.025 -0.008 0.023 -0.009 0.025 -0.010 0.029 -0.002 0.030 -0.002 0.031 -0.003 0.033 -0.003 0.036 12/20/11 -0.006 0.024 -0.006 0.022 -0.006 0.024 -0.007 0.027 0.018 0.026 0.018 0.027 0.019 0.029 0.021 0.032 12/27/11 0.018 0.032 0.016 0.028 0.019 0.032 0.021 0.036 -0.024 0.033 -0.023 0.031 -0.024 0.033 -0.026 0.036 01/03/12 0.013 0.026 0.011 0.023 0.013 0.026 0.015 0.030 -0.005 0.038 -0.005 0.037 -0.005 0.038 -0.006 0.043 SAMPLE DATES MAY VARY BY A FEW DAYS - See Note C 3-11

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 4A AIR PARTICULATES GAMMA SPECTRA - QTR 1 (pCi/ms)

DATE LOCATION PERIOD Be-7 Mn-54 Co-58 Co-60 Zn-65 Nb-95 Zr-95

(+/-) -000---0.001 01 12/28/10 - 03/01/11 0.111 0.043 -0.0005 0.0019 -0.0011 0.0035 0.0003 0.0016 0.0025 0.0049 0.0032 0.0040 -0.0013 0.0065 02 12/28/10 - 03/01/11 0.160 0.062 -0.0004 0.0024 0.0025 0.0049 -0.0005 0.0020 -0.0019 0.0065 0.0009 0.0053 0.0062 0.0103 03 12/28/10 - 03/01/11 0.091 0.068 -0.0014 0.0025 0.0005 0.0053 0.0000 0.0021 0.0057 0.0064 0.0000 0.0057 0.0036 0.0100 04 12/28/10 - 03/01/11 0.107 0.046 -0.0003 0.0016 0.0000 0.0035 0.0001 0.0015 0.0045 0.0047 0.0011 0.0035 0.0058 0.0064 10 12/28/10 - 03/01/11 0.144 0.059 0.0008 0.0023 -0.0025 0.0055 0.0014 0.0018 -0.0022 0.0048 0.0020 0.0058 0.0018 0.0100 11 12/28/10 - 03/01/11 0.137 0.080 -0.0014 0.0021 -0.0048 0.0048 -0.0015 0.0016 0.0020 0.0056 -0.0020 0.0043 0.0010 0.0076 15C 12/28/10 - 03/01/11 0.094 0.049 -0.0011 0.0015 -0.0020 0.0032 0.0000 0.0015 -0.0012 0.0035 0.0036 0.0030 -0.0013 0.0057 27 12/28/10 - 03/01/11 0.111 0.044 0.0001 0.0016 -0.0020 0.0034 -0.0003 0.0014 0.0042 0.0041 0.0015 0.0036 -0.0049 0.0074 01 03/01/11 - 03/29/11 0.094 0.065 -0.0003 0.0037 -0.0058 0.0047 0.0005 0.0035 -0.0074 0.0078 0.0020 0.0051 0.0028 0.0095 02 03/01/11 - 03/29/11 0.134 0.057 0.0005 0.0036 -0.0012 0.0053 -0.0023 0.0034 0.0042 0.0092 0.0001 0.0047 0.0079 0.0092 03 03/01/11 - 03/29/11 0.148 0.066 -0.0032 0.0044 -0.0011 0.0058 -0.0001 0.0030 0.0020 0.0111 0.0021 0.0061 0.0061 0.0105 04 03/01/11 - 03/29/11 0.127 0.076 -0.0005 0.0032 -0.0017 0.0052 -0.0012 0.0032 0.0009 0.0082 -0.0009 0.0048 -0.0062 0.0083 10 03/01/11 - 03/29/11 0.119 0.074 -0.0014 0.0030 -0.0035 0.0062 -0.0014 0.0043 -0.0008 0.0086 -0.0001 0.0050 -0.0018 0.0093 11 03/01/11 - 03/29/11 0.124 0.074 0.0006 0.0043 0.0013 0.0053 -0.0015 0.0033 -0.0024 0.0098 0.0019 0.0054 0.0025 0.0098 15C 03/01/11 - 03/29/11 0.090 0.056 0.0000 0.0029 -0.0009 0.0047 -0.0005 0.0035 -0.0023 0.0071 -0.0026 0.0044 0.0016 0.0078 27 03/01/11 - 03/29/11 0.100 0.070 -0.0008 0.0028 -0.0018 0.0050 0.0032 0.0039 -0.0008 0.0067 0.0071 0.0050 -0.0117 0.0081 Cs-1 Ce-141 Ce-144 0.037 LOCATION Ru-1 03 Ru-106 Cs-1 34 Ba-140

-0.0007----

0 1.000 0. 513

(-0100 01 12/28/10 - 03/01/11 -0.0114 0.0081 0.0197 0.0164 0.0018 0.0015 -0.0007 0.0014 -0.2060 1.5000 -0.0057 0.0136 -0.0024 0.0080 12/28/10 - 03/01/11 0.0052 0.0124 -0.0026 0.0198 0.0020 0.0021 1.8500 0.0017 0.0177 0.0042 0.0103 02 0.0001 0.0019 0.8200 03 12/28/10 - 03/01/11 0.0045 0.0109 -0.0019 0.0215 -0.0012 0.0023 -0.0011 0.0017 0.2520 1.9400 -0.0184 0.0162 -0.0050 0.0103 04 12/28/10 - 03/01/11 -0.0002 0.0076 0.0037 0.0131 0.0013 0.0016 -0.2420 1.3200 -0.0092 0.0145 -0.0019 0.0075 0.0005 0.0013 10 12/28/10 - 03/01/11 0.0038 0.0114 -0.0193 0.0223 0.0009 0.0022 0.0003 0.0019 -1.1800 1.6900 -0.0107 0.0198 -0.0047 0.0108 11 12/28/10 - 03/01/11 -0.0063 0.0096 0.0167 0.0175 0.0005 0.0024 -0.0001 0.0020 0.0897 1.5700 -0.0124 0.0167 -0.0029 0.0096 15C 12/28/10 - 03/01/11 -0.0017 0.0061 -0.0030 0.0144 0.0004 0.0012 -0.0002 0.0011 -0.7310 1.1600 0.0040 0.0132 -0.0059 0.0070 27 12/28/10 - 03/01/11 -0.0066 0.0080 -0.0071 0.0146 0.0005 0.0016 -0.0012 0.0015 0.4200 1.3100 -0.0005 0.0140 -0.0059 0.0076 01 03/01/11 - 03/29/11 0.0073 0.0067 0.0063 0.0275 0.0016 0.0039 0.0021 0.0031 0.2360 0.2210 0.0032 0.0107 0.0017 0.0166 02 03101/11 - 03/29/11 0.0000 0.0000 0.0026 0.0313 0.0011 0.0036 0.0041 0.0035 -0.0855 0.2240 -0.0093 0.0112 -0.0079 0.0158 03 03/01/11 - 03/29/11 0.0036 0.0078 -0.0059 0.0354 -0.0012 0.0039 0.0021 0.0043 -0.2010 0.2580 0.0130 0.0126 -0.0026 0.0177 04 03/01/11 - 03/29/11 0.0005 0.0058 0.0079 0.0299 0.0007 0.0033 -0.0016 0.0030 -0.1810 0.2080 0.0020 0.0094 0.0079 0.0149 10 03/01/11 - 03/29/11 0.0088 0.0066 -0.0108 0.0314 -0.0004 0.0034 -0.0009 0.0031 0.1060 0.2160 -0.0024 0.0092 -0.0105 0.0164 11 03/01/11 - 03/29/11 0.0029 0.0085 -0.0037 0.0289 0.0014 0.0033 -0.0016 0.0031 0.1680 0.2130 -0.0153 0.0116 -0.0162 0.0169 15C 03/01/11 - 03/29/11 0.0020 0.0068 -0.0103 0.0277 0.0001 0.0028 0.0013 0.0027 0.0245 0.1850 0.0010 0.0097 0.0047 0.0143 27 03/01/11 - 03/29/11 -0.0041 0.0068 -0.0115 0.0313 0.0002 0.0028 0.0010 0.0028 0.2480 0.2650 -0.0009 0.0114 0.0053 0.0157 3-12

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 4B AIR PARTICULATES GAMMA SPECTRA - QTR 2 (pCi/m')

DATE LOCATION PERIOD Be-7 Mn-54 Co-58 Co-60 Zn-65(-0.0009-0.0047 Nb-95 Zr-95

-0.0008-----0.0 01 03/29/11 - 05/31/11 0.109 0.047 -0.0008 0.0019 0.0012 0.0032 0.0011 0.0024 -0.0009 0.0047 -0.0025 0.0040 0.0030 0.0056 02 03/29/11 - 05/31/11 0.104 0.039 -0.0004 0.0021 -0.0002 0.0024 -0.0002 0.0017 0.0005 0.0036 -0.0018 0.0026 0.0012 0.0042 03 03/29/11 - 05/31/11 0.084 0.033 -0.0001 0.0022 -0.0018 0.0032 -0.0011 0.0023 0.0035 0.0056 0.0034 0.0032 -0.0020 0.0060 04 03/29/11 - 05/31/11 0.096 0.030 0.0005 0.0017 -0.0014 0.0026 -0.0002 0.0018 0.0000 0.0031 0.0009 0.0023 -0.0007 0.0044 10 03/29/11 - 05/31/11 0.118 0.039 0.0012 0.0019 0.0018 0.0035 -0.0015 0.0026 -0.0038 0.0051 -0.0002 0.0032 0.0043 0.0055 11 03/29/11- 05/31/11 0.144 0.051 0.0022 0.0026 0.0011 0.0036 0.0016 0.0025 0.0015 0.0067 0.0021 0.0048 -0.0007 0.0077 15C 03/29/11 - 05/31/11 0.105 0.040 0.0001 0.0019 0.0007 0.0035 -0.0015 0.0021 0.0043 0.0054 0.0017 0.0033 0.0002 0.0056 27 03/29/11- 05/31/11 0.111 0.045 -0.0013 0.0024 -0.0003 0.0038 0.0010 0.0021 0.0068 0.0063 0.0007 0.0046 0.0008 0.0074 01 05/31/11 - 06/28/11 0.171 0.089 -0.0027 0.0065 0.0060 0.0120 0.0010 0.0064 0.0086 0.0118 -0.0009 0.0107 -0.0004 0.0183 02 05/31/11 - 06/28/11 0.143 0.068 -0.0016 0.0036 0.0012 0.0057 0.0000 0.0035 0.0104 0.0093 -0.0046 0.0062 0.0056 0.0113 03 05/31/11 - 06/28/11 0.135 0.092 0.0003 0.0055 0.0001 0.0087 -0.0005 0.0063 0.0083 0.0154 -0.0050 0.0081 0.0077 0.0145 04 05/31/11 - 06/28/11 0.225 0.080 0.0027 0.0036 -0.0013 0.0054 0.0009 0.0032 0.0080 0.0083 -0.0015 0.0057 0.0013 0.0102 10 05/31/11 - 06/28/11 0.139 0.101 0.0022 0.0045 -0.0066 0.0086 0.0039 0.0045 0.0034 0.0120 0.0002 0.0080 0.0102 0.0141 11 05/31/11- 06/28/11 0.155 0.099 0.0015 0.0071 0.0013 0.0086 0.0064 0.0081 -0.0003 0.0155 0.0119 0.0118 -0.0075 0.0202 15C 05/31/11 - 06/28/11 0.287 0.082 -0.0035 0.0048 -0.0074 0.0069 0.0011 0.0039 -0.0059 0.0089 0.0033 0.0059 -0.0097 0.0108 27 05/31/11- 06/28/11 0.077 0.105 0.0007 0.0037 -0.0019 0.0068 -0.0024 0.0037 0.0036 0.0091 0.0007 0.0071 0.0046 0.0130 LOCATION Ru-103 Ru-106 Cs-134 Cs-137 Ba-140 Ce-141 Ce-144 0.0003-0.00-1 01 03/29/11 05/31/11 -0.0001 0.0053 -0.0028 0.0176 0.0003 0.0019 0.0016 0.0023 -0.1250 0.1330 0.0004 0.0067 -0.0054 0.0086 02 03/29/11 05/31/11 -0.0022 0.0046 0.0073 0.0163 0.0027 0.0019 0.0020 0.0020 -0.0159 0.1350 -0.0061 0.0068 0.0036 0.0092 03 03/29/11 05/31/11 -0.0003 0.0045 0.0006 0.0155 -0.0002 0.0024 -0.0002 0.0021 -0.1560 0.1690 -0.0043 0.0059 0.0071 0.0087 04 03/29/111 05/31/11 -0.0019 0.0047 -0.0140 0.0159 0.0021 0.0020 0.0025 0.0016 0.0596 0.1430 -0.0014 0.0064 -0.0029 0.0093 10 03/29/11 05/31/11 -0.0051 0.0043 -0.0028 0.0199 0.0023 0.0023 0.0009 0.0018 0.1300 0.1770 0.0035 0.0065 -0.0002 0.0085 11 03/29/11 05/31/11 -0.0042 0.0070 -0.0164 0.0233 0.0012 0.0029 0.0029 0.0027 0.0650 0.1990 0.0009 0.0082 0.0047 0.0126 15C 03/29/11 05/31/11 0.0037 0.0041 0.0062 0.0188 0.0018 0.0021 0.0011 0.0020 0.0210 0.1450 -0.0018 0.0063 0.0062 0.0087 27 03/29/11 05/31/11 -0.0026 0.0058 -0.0153 0.0237 0.0030 0.0013 0.0006 0.0023 0.1100 0.1940 -0.0060 0.0093 -0.0147 0.0124 01 05/31/11 06/28/11 -0.0128 0.0152 -0.0173 0.0545 0.0044 0.0063 0.0005 0.0050 0.0153 0.5610 0.0079 0.0212 0.0059 0.0244 02 05/31/11 06/28/11 -0.0006 0.0100 0.0236 0.0352 0.0030 0.0042 0.0008 0.0036 0.1110 0.4200 0.0009 0.0117 -0.0061 0.0141 03 05/31/11 06/28/11 0.0103 0.0136 -0.0029 0.0468 -0.0013 0.0053 0.0033 0.0049 -0.3490 0.5730 0.0021 0.0187 -0.0087 0.0242 04 05/31/11 06/28/11 0.0012 0.0083 0.0083 0.0302 0.0015 0.0033 0.0027 0.0033 0.0086 0.3470 -0.0045 0.0118 -0.0194 0.0153 10 05/31/11 06/28/11 -0.0098 0.0130 -0.0042 0.0414 0.0003 0.0056 0.0069 0.0045 -0.1040 0.4740 0.0021 0.0168 -0.0176 0.0212 11 05/31/11 06/28/11 0.0069 0.0208 -0.0299 0.0717 0.0070 0.0071 0.0005 0.0066 0.0435 0.6950 -0.0066 0.0236 0.0315 0.0291 15C 05/31/11 06/28/11 0.0021 0.0093 -0.0239 0.0360 0.0024 0.0044 -0.0002 0.0042 0.3600 0.3820 0.0028 0.0163 0.0092 0.0183 27 05/31/11 06/28/11 0.0047 0.0099 -0.0094 0.0361 -0.0014 0.0048 0.0011 0.0038 0.3760 0.4180 -0.0049 0.0161 -0.0150 0.0191 3-13

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 4C AIR PARTICULATES GAMMA SPECTRA - QTR 3 (pCi/me)

LOCATION Be-7 Mn-54 Co-58 Co-60 Zn-65 Nb-95 Zr-95

(+--) (+--) (+--) (+/-)

(+0-) (+1-) (+--)

01 0.115 0.039 0.0000 0.0013 -0.0015 0.0021 -0.0018 0.0015 -0.0007 0.0038 0.0009 0.0030 -0.0043 0.0052 02 0.107 0.036 0.0008 0.0018 -0.0008 0.0033 -0.0013 0.0013 0.0026 0.0038 -0.0005 0.0034 -0.0003 0.0051 03 0.125 0.042 -0.0002 0.0014 0.0007 0.0024 0.0003 0.0011 0.0034 0.0034 0.0008 0.0024 0.0005 0.0047 04 0.169 0.048 -0.0004 0.0017 -0.0002 0.0037 0.0017 0.0021 0.0019 0.0040 0.0031 0.0033 -0.0011 0.0063 10 0.109 0.046 0.0006 0.0011 -0.0002 0.0022 0.0004 0.0009 0.0002 0.0025 0.0006 0.0020 0.0000 0.0029 11 0.127 0.042 0.0004 0.0016 0.0000 0.0033 -0.0002 0.0015 0.0027 0.0040 0.0000 0.0027 0.0013 0.0051 15C 0.098 0.037 0.0002 0.0010 -0.0014 0.0015 -0.0020 0.0014 -0.0022 0.0024 0.0017 0.0023 -0.0009 0.0022 27 0.108 0.040 -0.0013 0.0018 -0.0013 0.0027 -0.0013 0.0017 -0.0001 0.0040 0.0013 0.0029 0.0002 0.0053 LOCATION Ru-103 Ru-106 Cs-134 Cs-137 Ba-140 Ce-141 Ce-144

(+1-) (+/-) (+00) (+01

) (+/-) (+1-) (+0-)

01 0.0003 0.0040 0.0083 0.0103 0.0017 0.0014 0.0001 0.0012 0.2560 0.2860 0.0003 0.0067 0.0003 0.0062 02 -0.0041 0.0054 -0.0006 0.0152 0.0015 0.0019 -0.0006 0.0014 -0.1650 0.3710 -0.0010 0.0074 -0.0013 0.0066 03 0.0013 0.0038 -0.0021 0.0115 0.0019 0.0013 -0.0005 0.0011 -0.1030 0.2800 -0.0077 0.0058 0.0007 0.0056 04 0.0047 0.0053 0.0037 0.0133 0.0025 0.0018 -0.0004 0.0015 -0.1120 0.3960 0.0045 0.0083 0.0043 0.0073 10 0.0003 0.0033 -0.0002 0.0095 -0.0012 0.0011 0.0001 0.0006 -0.2600 0.2390 -0.0015 0.0049 -0.0034 0.0047 11 0.0006 0.0045 -0.0056 0.0117 0.0011 0.0016 0.0859 0.3420 0.0032 0.0072 -0.0100 0.0068 0.00002 0.0011 15C 0.0017 0.0026 -0.0001 0.0090 -0.0003 0.0009 0.0000 0.0009 0.2130 0.1810 -0.0025 0.0042 -0.0001 0.0037 27 -0.0012 0.0050 -0.0018 0.0129 0.0020 0.0017 0.0006 0.0013 -0.0917 0.3370 0.0016 0.0081 0.0041 0.0079 3-14

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 4D AIR PARTICULATES GAMMA SPECTRA - QTR 4 (pCi/M 3)

LOCATION DATE Be-7 Mn-54 Co-58 Co-60 Zn-65 Nb-95 Zr-95 0.11 0.28 0.004 .000--.001)0001 -0.01 0 9 0 4 0 01 09/27/11 - 01/03/12 0.113 0.028 -0.0004 0.0010 -0.0001 0.0017 -0.0003 0.0012 0.0010 0.0029 0.0014 0.0021 -0.0009 0.0033 02 09/27/11 - 01/03/12 0.118 0.031 -0.0002 0.0009 -0.0009 0.0016 -0.0007 0.0008 -0.0001 0.0022 0.0021 0.0016 -0.0001 0.0032 03 09/27/11 - 01/03/12 0.105 0.033 0.0000 0.0010 0.0003 0.0017 0.0004 0.0011 0.0030 0.0034 0.0009 0.0018 0.0008 0.0029 04 09/28/11 - 01/03/12 0.130 0.044 0.0005 0.0014 -0.0024 0.0021 -0.0006 0.0013 0.0007 0.0035 0.0016 0.0021 -0.0020 0.0038 10 09/27/11 - 01/03/12 0.141 0.023 0.0000 0.0007 -0.0008 0.0012 -0.0002 0.0007 0.0033 0.0022 0.0012 0.0015 -0.0005 0.0024 11 09/27/11 - 01/03/12 0.098 0.032 0.0009 0.0012 0.0000 0.0022 -0.0005 0.0010 0.0024 0.0038 0.0008 0.0027 0.0003 0.0039 15C 09/27/11 - 01/03/12 0.094 0.037 -0.0017 0.0021 0.0019 0.0033 0.0004 0.0019 0.0032 0.0044 0.0022 0.0029 0.0004 0.0049 27 09/27/11 - 01/03/12 0.108 0.037 0.0008 0.0014 -0.0003 0.0020 0.0000 0.0011 -0.0033 0.0035 -0.0005 0.0024 -0.0009 0.0039 LOCATION DATE Ru-103 Ru-106 Cs-134 Cs-137 Ba-140 Ce-141 Ce-144 01 09/27/11 - 01/03/12 -0.0008 0.0027 0.0006 0.0087 0.0014 0.0012 0.0001 0.0010 -0.0513 0.1390 -0.0009 0.0038 0.0014 0.0037 02 09/27/11 - 01/03/12 -0.0011 0.0025 -0.0071 0.0082 0.0011 0.0012 0.0000 0.0008 -0.0925 0.1240 0.0006 0.0039 0.0016 0.0044 03 09/27/11 - 01/03/12 0.0005 0.0028 0.0052 0.0081 0.0009 0.0012 0.0011 0.0009 0.0655 0.1360 -0.0030 0.0039 -0.0008 0.0041 04 09/28/11 - 01/03/12 -0.0006 0.0039 -0.0022 0.0099 0.0014 0.0013 -0.0001 0.0012 -0.0001 0.1730 0.0000 0.0059 -0.0002 0.0067 10 09/27/11 - 01/03/12 -0.0006 0.0020 -0.0041 0.0067 0.0008 0.0010 0.0002 0.0007 0.0050 0.0993 0.0028 0.0033 -0.0028 0.0036 11 09/27/11 - 01/03/12 0.0000 0.0032 -0.0087 0.0112 0.0019 0.0016 -0.0007 0.0012 -0.0891 0.1670 -0.0005 0.0047 -0.0084 0.0054 15C 09/27/11 - 01/03/12 0.0066 0.0049 -0.0098 0.0153 0.0027 0.0022 0.0000 0.0014 -0.0832 0.2210 -0.0053 0.0059 -0.0002 0.0065 27 09/27/11 - 01/03/12 0.0024 0.0035 -0.0049 0.0119 0.0014 0.0018 -0.0001 0.0013 -0.0672 0.1790 -0.0040 0.0058 0.0044 0.0062 3-15

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE5 AIR PARTICULATES Strontium Analyses for strontium in air particulate filters were not analyzed in 2011. See discussion in Section 4.5.

3-16

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 6 SOIL (pCi/g dry wt.)

COLLECTION LOCATION DATE Be-7(+-.. K-40 Cr-51 Mn-54 Co-58 Fe-59

)

03 07/20/2011 -0.14 0.32 16.00 1.36 0.00 0.33 0.02 0.04 -0.01 0.03 -0.01 0.08 04 07/20/2011 -0.20 0.29 14.50 1.14 0.19 0.31 0.04 0.03 -0.01 0.03 -0.06 0.07 14C 07/20/2011 -0.30 0.36 14.20 1.41 0.02 0.36 -0.02 0.05 0.00 0.04 -0.07 0.09 COLLECTION LOCATION ....................

DATE Co-60--)- Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 I----- ---- -------- ---- --

03 07/20/2011 -0.02 0.04 -0.03 0.10 0.03 0.04 -0.01 0.06 0.02 0.04 -0.01 0.31 04 07/20/2011 0.01 0.04 0.01 0.08 0.04 0.04 0.00 0.06 -0.01 0.03 -0.16 0.29 14C 07/20/2011 0.00 0.05 0.03 0.10 0.02 0.05 -0.01 0.08 -0.03 0.04 0.16 0.38 COLLECTION LOCATION Cs-137 Ce-141 Ce-144 Th-232 decay chain*

0 DATE 0

03.............

. - 0.-1Sb-125 Cs-134 03 07/20/2011 -0.05 0.11 0.00 0.04 0.46 0.09 0.02 0.06 -0.32 0.25 1.10 0.21 04 07/20/2011 0.03 0.09 -0.01 0.04 0.29 0.07 -0.01 0.06 -0.14 0.23 1.42 0.26 14C 07/20/2011 -0.08 0.11 -0.02 0.05 0.68 0.10 0.02 0.06 -0.13 0.23 1.28 0.11

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-17

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 7 Cow Milk (pCi/I)

COLLECTION LOCATION DATE Sr-89 Sr-90 K-40 1-131 Cs-134 Cs-137 Ba-140 La-140

(+1-) (+1-) (+/-) (*/-) (+/-) (*/-) (+/-) (*/-)

18 02/16/2011 1250 90 0.10 0.37 1.6 2.9 0.8 2.5 -1.3 11.6 -3.8 3.2 18 03/24/2011 -0.94 4.36 0.84 0.70 1100 134 -0.05 0.16 -2.6 4.0 0.0 4.0 4.0 23.1 -2.5 6.8 18 04/07/2011 1150 140 0.53 0.49 -1.7 4.0 1.1 3.8 -6.1 25.1 2.4 5.5 18 04/21/2011 1220 46 -0.03 0.25 -0.6 1.2 1.2 1.2 -1.6 7.8 1.7 2.3 18 05/05/2011 1210 145 0.05 0.37 1.1 4.6 -1.8 4.1 7.5 23.3 -2.1 6.9 18 05/18/2011 1240 152 -0.46 0.29 -1.0 3.2 -0.5 3.6 -0.5 24.2 -4.5 6.8 18 06/09/2011 1320 150 -0.17 0.22 -5.2 4.2 -2.7 4.1 6.1 27.6 -5.0 6.5 18 06/30/2011 5.35 4.60 1.24 0.81 1180 172 -0.32 0.38 -5.5 5.3 1.2 5.0 -11.2 27.7 -4.8 8.1 18 07/14/2011 1360 157 -0.24 0.34 -5.3 4.1 -0.4 4.3 8.1 16.9 2.9 6.0 18 07/28/2011 1360 152 0.20 0.37 0.6 3.8 1.0 4.0 -1.8 14.0 -0.9 5.1 18 08/03/2011 1090 122 -0.12 0.31 1.2 3.3 2.9 3.7 18.0 15.4 -2.5 4.6 18 08/18/2011 1080 112 0.07 0.29 -0.2 2.0 2.2 1.7 2.0 7.3 0.3 2.9 18 09/08/2011 1230 170 -0.05 0.30 -4.5 4.8 3.4 5.1 -2.3 17.6 1.3 4.7 18 09/28/2011 0.00 4.56 0.27 0.80 1500 196 -0.16 0.32 5.5 5.9 -2.4 6.9 -25.4 30.7 1.8 10.1 18 10/11/2011 1040 132 -0.55 0.34 0.6 4.0 -1.9 3.9 -16.6 19.8 1.2 4.9 18 10/25/2011 1260 43 0.08 0.35 0.2 1.2 1.5 1.1 0.8 7.3 -1.2 2.0 18 11/08/2011 1220 136 0.21 0.36 0.1 3.2 -0.6 3.2 -3.3 14.2 1.3 3.8 18 12/22/2011 0.65 4.28 0.52 0.76 1270 148 -6.82 10.90 -0.3 4.1 1.3 3.7 3.0 21.4 4.5 8.4 3-18

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 8 GOAT MILK (pCi/I)

COLLECTION LOCATION DATE Sr-89 (+--) Sr-90 (+ ) .- K-40(+.-) 1-131 (+.-) Cs-134 (+.-) Cs-137 (+.-) Ba-140 (+1-) La-140 (+1-)

21 06/30/2011 See Note E See Note E 1230 195 0.18 0.41 2.9 4.6 3.9 4.9 -12.0 34.0 4.5 9.7 21 07/28/2011 686 125 0.52 0.39 -1.0 3.8 2.1 3.7 13.7 15.3 0.1 5.2 21 08/05/2011 845 148 -0.16 0.48 -0.9 3.1 2.2 3.5 4.7 30.2 4.4 9.6 24C 05/18/2011 3.54 5.63 0.19 0.64 1260 127 -0.23 0.47 -4.1 5.1 8.0 7.6 -1.0 39.2 -6.9 11.0 24C 08/03/2011 See Note E See Note E 1360 152 -0.29 0.44 -5.9 3.6 2.2 4.2 -5.6 17.1 -3.8 5.5 3-19

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 9 PASTURE GRASS / HAY (pCi/g wet wt.)

Location 18 COLLECTION DATE Be-7 (+--) K-40 (+--) Cr-51 (+/-) Mn-54 (+--) Co-58 (+--) Fe-59 (+1-) Co-60 (+--)

10/11/2011 3.170 0.224 7.33 0.38 0.082 0.113 -0.004 0.009 0.003 0.010 0.009 0.024 -0.013 0.011 10/11/2011 -0.079 0.143 10.20 0.74 -0.024 0.137 0.006 0.016 0.004 0.016 -0.013 0.038 -0.011 0.023 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131

(+7/-)ý- - -- (+/-) --- - -- - - +/1- - ----- -- - ) ---- -- )7 (+7-) -- -- /-)--

10/11/2011 -0.019 0.022 -0.002 0.011 0.005 0.019 0.006 0.011 -0.004 0.081 -0.014 0.025 -0.027 0.036 10/11/2011 -0.011 0.051 0.007 0.019 0.003 0.028 0.004 0.015 0.033 0.140 0.000 0.039 -0.007 0.032 Cs-134 Cs-137 Ba-140 La-140 Ce-141 Ce-144 Th-232 decay chain*

(+/-) (+/-) (+--) (+C-) (+1-) (+T-) (+/-)

10/11/2011 -0.026 0.010 0.007 0.010 0.015 0.071 -0.004 0.018 -0.020 0.021 -0.040 0.063 0.043 0.038 10/11/2011 -0.004 0.017 -0.023 0.018 0.081 0.094 0.013 0.029 -0.003 0.024 0.010 0.088 0.050 0.063

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-20

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 9 PASTURE GRASS / HAY (pCi/g wet wt.)

Location 21 COLLECTION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 Co-6O

(+/-) (+/-) (+/-) (+1-) (+/-) (+/-) (+/-)

01/18/2011 0.294 0.124 11.40 0.39 -0.028 0.113 -0.005 0.010 -0.011 0.011 0.013 0.024 -0.001 0.017 02/16/2011 -0.001 0.092 9.76 0.54 0.004 0.087 0.001 0.011 -0.003 0.011 -0.032 0.027 -0.007 0.015 03/24/2011 0.021 0.069 12.70 0.50 -0.051 0.086 -0.001 0.007 -0.001 0.008 -0.009 0.021 -0.004 0.011 04/07/2011 -0.049 0.079 11.60 0.59 0.022 0.096 0.003 0.009 0.006 0.011 0.007 0.027 -0.001 0.015 04/21/2011 0.039 0.048 13.90 0.55 0.021 0.059 0.003 0.005 0.004 0.005 0.000 0.014 -0.006 0.010 05/05/2011 2.220 0.333 6.69 0.68 -0.039 0.126 -0.006 0.015 -0.006 0.014 0.005 0.036 -0.009 0.018 05/18/2011 1.250 0.205 4.57 0.40 0.021 0.101 0.001 0.009 -0.003 0.009 0.005 0.029 0.005 0.013 06/14/2011 1.660 0.349 4.58 0.70 0.025 0.136 -0.017 0.017 0.009 0.020 0.019 0.048 0.009 0.023 06/30/2011 1.150 0.229 3.77 0.40 0.074 0.126 0.000 0.011 -0.009 0.011 -0.007 0.026 -0.002 0.012 07/14/2011 1.410 0.300 3.65 0.66 0.019 0.148 0.007 0.018 0.001 0.020 0.015 0.037 0.008 0.022 07/28/2011 1.290 0.200 3.85 0.40 0.023 0.101 -0.005 0.011 -0.001 0.010 -0.023 0.022 0.000 0.012 08/05/2011 1.310 0.246 4.80 0.39 -0.011 0.111 0.003 0.011 -0.006 0.011 -0.008 0.022 -0.006 0.012 08/18/2011 3.840 0.259 5.17 0.36 -0.005 0.100 -0.006 0.010 -0.001 0.010 -0.008 0.021 -0.001 0.012 09/15/2011 6.460 0.401 4.70 0.47 -0.068 0.125 -0.001 0.012 0.001 0.011 -0.016 0.027 -0.009 0.015 09/28/2011 3.040 0.289 5.12 0.44 0.016 0.099 -0.006 0.011 -0.008 0.010 -0.017 0.024 -0.010 0.013 10/11/2011 6.720 0.309 5.19 0.36 0.012 0.111 0.003 0.009 -0.002 0.008 0.000 0.022 -0.012 0.011 10/26/2011 6.920 0.383 4.09 0.40 0.022 0.122 -0.001 0.009 0.005 0.010 0.004 0.026 0.000 0.010 11/08/2011 0.972 0.357 11.90 0.82 -0.057 0.171 0.003 0.016 0.008 0.018 0.015 0.036 -0.012 0.019 12/22/2011 0.482 0.146 13.00 0.43 0.067 0.106 0.004 0.011 -0.007 0.011 -0.009 0.025 0.003 0.012 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-1.25 1-131 01/18/2011 -0.002 0.026 0.016 0.013 0.006 0.019 -0.021 0.012 0.092 0.093 0.000 0.029 -0.007 0.035 02/16/2011 -0.021 0.029 -0.003 0.010 -0.009 0.018 -0.009 0.011 0.016 0.085 0.011 0.026 0.009 0.020 03/24/2011 0.005 0.018 0.008 0.009 0.006 0.014 0.002 0.009 0.005 0.066 0.022 0.019 0.044 0.034 04/07/2011 -0.033 0.028 0.000 0.010 0.006 0.019 -0.011 0.010 -0.019 0.085 0.010 0.024 0.010 0.029 04/21/2011 -0.011 0.014 -0.002 0.005 -0.005 0.010 0.003 0.006 -0.032 0.047 0.003 0.014 -0.007 0.018 05/05/2011 -0.043 0.038 0.001 0.016 -0.018 0.027 -0.010 0.014 -0.040 0.125 -0.021 0.039 0.036 0.022 05/18/2011 0.000 0.022 -0.003 0.011 0.004 0.017 -0.004 0.011 0.024 0.072 -0.005 0.024 0.006 0.034 06/14/2011 0.031 0.050 -0.006 0.021 0.005 0.033 0.013 0.018 0.122 0.153 -0.019 0.042 0.019 0.030 06/30/2011 0.002 0.025 0.015 0.014 0.007 0.020 -0.001 0.012 -0.088 0.090 -0.005 0.029 -0.030 0.039 07/14/2011 0.045 0.040 -0.009 0.021 -0.029 0.034 0.000 0.018 0.146 0.169 0.034 0.049 -0.043 0.027 07/28/2011 -0.039 0.028 -0.004 0.011 -0.007 0.021 0.008 0.011 -0.066 0.109 -0.028 0.029 0.004 0.018 08/05/2011 -0.022 0.026 0.000 0.011 -0.004 0.019 -0.001 0.012 0.055 0.096 0.009 0.028 -0.009 0.032 08/18/2011 -0.013 0.023 0.006 0.010 0.020 0.018 -0.001 0.011 -0.028 0.082 0.012 0.028 0.001 0.019 09/15/2011 -0.024 0.032 0.006 0.012 0.002 0.019 -0.004 0.012 0.036 0.094 -0.002 0.030 0.007 0.032 09/28/2011 0.016 0.024 -0.003 0.012 -0.002 0.020 0.003 0.012 -0.109 0.093 -0.011 0.031 -0.018 0.020 10/11/2011 -0.022 0.025 -0.005 0.010 -0.003 0.017 -0.004 0.010 0.024 0.086 0.008 0.024 -0.021 0.035 10/26/2011 -0.040 0.022 0.004 0.011 -0.014 0.019 -0.007 0.012 0.007 0.095 -0.021 0.026 -0.005 0.032 11/08/2011 0.003 0.042 -0.014 0.018 0.005 0.029 0.004 0.016 0.079 0.171 -0.005 0.047 0.016 0.032 12/22/2011 -0.013 0.026 0.013 0.011 0.010 0.019 -0.011 0.012 -0.060 0.094 0.012 0.027 0.018 0.030 3-21

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 9 PASTURE GRASS / HAY (pCi/g wet wt.)

Location 21 COLLECTION DATE Cs-134 (+--) Cs-137 (+--) Ba-140 (+--) La-140 (+--) Ce-141 (+--) Ce-144 (+1-) Th-232 decay chain*

(+--)

01/18/2011 -0.005 0.012 0.021 0.013 0.049 0.075 -0.023 0.022 -0.007 0.018 -0.021 0.061 0.116 0.027 02/16/2011 -0.013 0.010 0.008 0.011 -0.012 0.051 -0.005 0.011 -0.005 0.015 -0.016 0.055 0.042 0.050 03/24/2011 0.001 0.008 0.006 0.008 -0.023 0.063 0.009 0.016 -0.004 0.015 0.033 0.047 0.004 0.025 04/07/2011 -0.007 0.011 0.008 0.010 -0.016 0.063 0.009 0.016 0.000 0.018 0.013 0.058 0.001 0.037 04/21/2011 -0.002 0.005 0.001 0.005 0.021 0.035 0.003 0.008 0.007 0.011 -0.021 0.037 -0.036 0.014 05/05/2011 0.001 0.016 -0.020 0.016 0.001 0.069 -0.019 0.017 -0.029 0.024 0.040 0.096 0.064 0.059 05/18/2011 -0.008 0.010 0.007 0.009 0.034 0.071 -0.011 0.020 0.001 0.019 0.020 0.063 0.013 0.037 06/14/2011 -0.015 0.020 0.013 0.019 0.040 0.099 -0.012 0.029 0.010 0.030 0.007 0.113 0.027 0.078 06/30/2011 -0.008 0.011 0.009 0.012 0.000 0.073 0.000 0.014 0.008 0.023 -0.041 0.079 0.053 0.051 07/14/2011 0.010 0.021 0.027 0.021 -0.069 0.082 0.001 0.019 0.003 0.025 -0.093 0.106 0.044 0.062 07/28/2011 0.008 0.012 0.010 0.013 0.018 0.048 -0.006 0.012 -0.026 0.021 -0.047 0.077 0.047 0.044 08/05/2011 0.004 0.011 0.012 0.011 0.049 0.073 0.002 0.017 -0.020 0.021 -0.089 0.074 0.036 0.029 08/18/2011 -0.001 0.011 0.002 0.010 -0.007 0.050 -0.005 0.014 0.001 0.018 0.029 0.070 0.022 0.043 09/15/2011 -0.007 0.012 0.003 0.012 0.017 0.072 -0.028 0.023 -0.007 0.020 -0.034 0.068 0.045 0.044 09/28/2011 0.002 0.010 -0.005 0.011 0.034 0.053 0.000 0.019 -0.014 0.020 -0.063 0.082 0.055 0.026 10/11/2011 0.000 0.009 0.006 0.010 0.047 0.068 0.003 0.022 -0.017 0.019 -0.022 0.057 0.085 0.070 10/26/2011 0.004 0.011 0.015 0.011 -0.067 0.070 0.000 0.019 -0.008 0.021 0.039 0.068 0.032 0.029 11/08/2011 0.003 0.020 -0.002 0.016 -0.068 0.091 -0.007 0.020 -0.047 0.029 0.014 0.104 0.232 0.064 12/22/2011 -0.008 0.012 0.002 0.011 -0.014 0.069 -0.020 0.018 0.007 0.023 -0.026 0.073 0.026 0.034

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-22

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 9 PASTURE GRASS / HAY (pCi/g wet wt.)

Location 24 COLLECTION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 Co-60

(+1-) (+--) (+/-) (+/-) (+/-) (+/-) (+1-)

01/18/2011 0.121 0.168 11.60 0.46 -0.029 0.125 0.002 0.012 -0.005 0.012 0.002 0.028 -0.007 0.014 02/16/2011 -0.037 0.058 9.57 0.40 0.009 0.062 0.002 0.007 -0.007 0.007 -0.008 0.018 0.011 0.011 03/24/2011 0.035 0.066 6.95 0.26 0.045 0.082 0.006 0.006 0.004 0.007 -0.010 0.018 -0.003 0.008 04/07/2011 0.119 0.098 21.60 0.50 0.026 0.109 -0.006 0.010 -0.001 0.011 0.007 0.027 0.009 0.014 04/21/2011 3.350 0.177 4.72 0.28 -0.018 0.070 0.005 0.007 -0.003 0.007 -0.002 0.016 0.000 0.008 05/05/2011 0.857 0.253 5.64 0.57 -0.080 0.123 0.004 0.012 0.003 0.012 0.002 0.031 0.005 0.016 06/14/2011 2.200 0.311 5.02 0.62 0.041 0.151 -0.001 0.016 -0.006 0.015 0.023 0.031 0.000 0.019 06/30/2011 1.500 0.212 4.48 0.46 -0.021 0.130 0.000 0.011 0.004 0.012 0.010 0.029 -0.011 0.013 07/14/2011 0.622 0.281 5.62 0.79 0.054 0.162 0.008 0.022 0.005 0.023 -0.009 0.049 0.002 0.028 07128/2011 1.410 0.262 5.47 0.56 -0.073 0.116 -0.005 0.013 0.008 0.013 -0.004 0.028 0.009 0.016 08/15/2011 2.290 0.307 13.60 0.75 0.013 0.159 -0.004 0.015 -0.013 0.018 -0.014 0.035 -0.004 0.020 09/15/2011 1.910 0.205 4.56 0.38 0.062 0.100 -0.001 0.009 -0.001 0.008 0.003 0.021 0.009 0.011 09/28/2011 1.970 0.236 5.69 0.45 0.001 0.090 0.002 0.010 0.005 0.010 -0.012 0.023 0.000 0.011 10/11/2011 2.740 0.195 5.75 0.34 0.019 0.109 0.001 0.008 0.002 0.009 0.007 0.021 0.002 0.010 10/25/2011 5.120 0.282 6.21 0.38 -0.018 0.110 0.006 0.009 0.000 0.010 -0.021 0.025 -0.006 0.012 11/08/2011 6.580 0.406 8.15 0.61 -0.020 0.124 0.006 0.013 -0.001 0.013 0.009 0.030 -0.011 0.017 12/22/2011 5.780 0.378 2.75 0.40 -0.056 0.143 0.007 0.013 -0.001 0.012 0.020 0.027 0.009 0.012 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131

(+/- (+-)

(/-)(+/- (+-) (/-)(+/-)

01/18/2011 0.002 0.031 0.017 0.013 0.021 0.021 -0.005 0.014 -0.004 0.109 -0.015 0.031 -0.025 0.037 02/16/2011 0.000 0.021 -0.002 0.008 -0.009 0.013 -0.006 0.008 -0.036 0.060 -0.012 0.018 -0.017 0.014 03/24/2011 0.010 0.018 0.006 0.008 -0.001 0.014 -0.010 0.008 0.019 0.058 -0.006 0.018 0.014 0.036 04/07/2011 -0.050 0.027 -0.003 0.011 -0.007 0.020 0.014 0.012 0.089 0.091 -0.007 0.027 0.019 0.032 04/21/2011 -0.026 0.016 0.001 0.006 0.002 0.012 -0.002 0.007 -0.006 0.057 -0.003 0.017 0.031 0.029 05/05/2011 -0.041 0.033 0.008 0.015 -0.010 0.020 -0.002 0.014 0.039 0.121 0.008 0.037 0.008 0.021 06/14/2011 -0.004 0.041 0.003 0.016 0.009 0.027 -0.014 0.015 -0.142 0.143 -0.016 0.042 0.035 0.032 06/30/2011 -0.022 0.025 -0.013 0.013 -0.010 0.023 0.004 0.013 0.084 0.103 0.027 0.029 -0.006 0.035 07/14/2011 -0.041 0.064 0.021 0.029 0.011 0.042 0.007 0.021 -0.150 0.194 -0.010 0.057 0.004 0.031 07/28/2011 -0.001 0.027 0.011 0.015 -0.015 0.024 0.008 0.013 0.074 0.132 -0.003 0.035 -0.003 0.020 08/15/2011 -0.008 0.039 0.023 0.017 0.000 0.028 -0.010 0.017 0.037 0.136 -0.027 0.046 -0.020 0.034 09/15/2011 -0.017 0.023 -0.002 0.009 -0.005 0.018 0.007 0.011 -0.025 0.076 0.004 0.025 -0.021 0.028 09/28/2011 -0.017 0.026 -0.001 0.010 -0.007 0.018 -0.004 0.010 -0.059 0.088 0.007 0.026 0.004 0.018 10/11/2011 -0.033 0.022 -0.009 0.009 -0.002 0.016 -0.007 0.011 -0.012 0.080 0.017 0.025 -0.023 0.036 10/25/2011 -0.017 0.023 0.005 0.009 0.022 0.017 0.001 0.011 -0.072 0.082 -0.017 0.027 0.005 0.033 11/08/2011 -0.014 0.034 0.003 0.013 0.000 0.023 0.002 0.013 0.008 0.107 -0.019 0.032 0.022 0.027 12/22/2011 -0.049 0.032 0.001 0.014 -0.002 0.023 0.000 0.012 -0.013 0.094 0.005 0.034 0.005 0.034 3-23

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 9 PASTURE GRASS / HAY (pCi/g wet wt.)

Location 24 COLLECTION DATE Cs-134 (+--) Cs-137 (+/-) Ba-140 (+--) La-140 (+/-) Ce-141 (+--) Ce-144 (+/-) Th-232 decay chain*

(+--)

01/18/2011 -0.048 0.013 0.059 0.022 0.029 0.084 -0.013 0.022 -0.009 0.023 -0.003 0.078 0.045 0.030 02/16/2011 -0.005 0.008 0.005 0.007 -0.001 0.035 0.002 0.009 0.008 0.011 -0.006 0.042 0.010 0.017 03/24/2011 -0.002 0.007 0.012 0.011 -0.009 0.064 -0.023 0.018 0.003 0.014 -0.003 0.042 0.033 0.015 04/07/2011 0.002 0.011 0.030 0.012 0.031 0.073 -0.002 0.018 -0.002 0.019 0.012 0.068 0.088 0.037 04/21/2011 0.001 0.008 0.007 0.007 0.012 0.036 -0.003 0.008 -0.003 0.013 0.024 0.047 0.022 0.034 05/05/2011 0.008 0.014 0.012 0.014 0.069 0.064 -0.001 0.013 0.011 0.021 0.056 0.090 0.012 0.025 06/14/2011 -0.008 0.014 -0.007 0.016 0.014 0.079 -0.006 0.015 -0.024 0.028 0.016 0.112 0.011 0.067 06/30/2011 0.006 0.012 0.020 0.013 -0.013 0.077 -0.004 0.021 0.018 0.023 -0.005 0.079 0.009 0.045 07/14/2011 -0.017 0.026 0.025 0.025 -0.027 0.095 0.018 0.031 0.019 0.033 0.089 0.134 -0.061 0.095 07/28/2011 0.003 0.014 0.003 0.013 0.001 0.062 0.000 0.015 -0.005 0.023 -0.038 0.099 0.019 0.048 08/15/2011 -0.030 0.019 0.056 0.027 -0.056 0.089 0.009 0.024 0.001 0.031 -0.064 0.106 0.049 0.124 09/15/2011 -0.008 0.010 -0.001 0.009 0.044 0.057 -0.011 0.019 0.002 0.017 0.004 0.062 0.044 0.059 09/28/2011 0.002 0.016 0.007 0.009 -0.010 0.048 0.003 0.011 -0.019 0.019 0.020 0.074 0.029 0.061 10/11/2011 0.001 0.010 0.001 0.009 -0.048 0.068 -0.006 0.017 -0.020 0.020 0.061 0.063 0.029 0.059 10/25/2011 -0.022 0.010 0.014 0.009 -0.025 0.067 0.008 0.019 -0.007 0.019 -0.017 0.067 0.030 0.037 11/08/2011 -0.005 0.014 0.014 0.013 0.029 0.067 -0.004 0.019 -0.005 0.022 -0.009 0.081 0.059 0.064 12/22/2011 -0.005 0.014 -0.006 0.012 0.002 0.076 0.005 0.017 -0.002 0.023 0.003 0.087 0.056 0.048

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-24

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 10 WELL WATER (pCi/I)

COLLECTION L*OCATION D...A.T.E............ H-2 ......... ........ Bea-!------- K-40 Cr-Si Mn-54 Co-58 Fe-59

(+/-)(+-

71 03/09/2011 366.0 612.0 -1.57 15.80 2.66 27.20 -5.68 19.60 1.68 1.59 0.09 1.69 1.52 3.77 71 06/22/2011 353.0 1040.0 14.70 34.00 25.00 58.70 -23.30 31.70 1.34 3.78 0.47 3.82 1.45 7.33 71 09/14/2011 188.0 466.0 6.65 19.20 72.10 38.10 1.40 2.06 -0.96 2.10 -2.33 4.47 71 12/12/2011 135.0 265.0 -3.76 35.30 42.40 72.30 10.30 38.30 -1.18 3.70 -0.45 3.93 3.07 8.19 03/09/2011 88.3 563.0 5.52 15.60 1.77 41.00 -24.50 19.40 -0.14 1.46 -0.63 1.59 0.42 3.45 06/08/2011 -371.0 441.0 7.59 10.50 6.56 43.60 0.89 13.90 -0.02 0.85 -0.09 1.02 -0.65 2.40 09/07/2011 -10.1 574.0 2.12 24.20 43.10 53.30 -2.39 31.10 -0.91 2.53 -2.69 2.88 -3.22 6.08 12/12/2011 -3580.0 790.0 3.85 11.50 -4.58 19.30 -11.90 15.60 0.40 1.11 -0.91 1.24 0.08 2.70 03/08/2011 89.3 570.0 4.96 13.80 -5.80 29.10 -7.64 16.10 -0.06 1.55 -0.59 1.65 2.23 3.49 06/07/2011 -373.0 437.0 6.78 7.94 31.00 29.50 1.10 11.10 -0.01 0.67 0.32 0.74 -0.90 1.57 09/20/2011 -95.1 513.0 -15.90 28.90 47.30 57.80 -0.63 29.10 -2.23 3.15 -1.27 3.28 -2.58 6.47 12/08/2011 -218.0 432.0 -21.70 32.10 -16.60 49.30 -17.50 32.30 -0.66 3.54 0.56 3.14 0.49 6.67 03/08/2011 206.0 563.0 3.24 14.40 -6.56 25.70 -0.68 19.00 0.20 1.50 -1.47 1.57 1.13 3.48 06/07/2011 469.0 499.0 1.70 7.33 -0.01 22.20 1.95 9.09 0.09 0.72 -0.07 0.66 0.20 1.79 09/20/2011 300.0 529.0 10.40 33.50 23.60 53.40 -9.83 38.50 -0.80 3.85 -1.13 4.15 -9.14 6.96 12/08/2011 -9.8 440.0 -5.43 33.10 58.40 49.70 -47.50 32.80 -2.47 3.45 -2.02 3.54 1.17 6.63 03/08/2011 128.0 560.0 10.40 14.50 14.20 31.90 -13.00 18.00 -0.70 1.34 0.50 1.38 -0.59 3.13 06/07/2011 67.5 536.0 4.66 7.96 66.90 39.80 1.74 11.70 -0.28 0.65 -0.13 0.74 -0.84 2.01 09/22/2011 0.0 527.0 -22.00 23.60 -14.40 42.40 -1.60 24.90 1.57 3.08 -1.14 3.20 -1.48 6.95 12/08/2011 69.2 452.0 19.90 32.60 56.00 63.40 21.00 36.30 -0.93 3.47 -3.00 3.52 -1.23 6.96 03/07/2011 31.1 529.0 -0.07 11.80 56.60 31.60 -0.08 15.60 0.10 1.17 0.43 1.27 -1.23 2.82 06/08/2011 119.0 476.0 4.59 8.56 -79.50 23.10 -5.84 9.72 -0.31 0.66 0.10 0.98 -1.05 2.12 09/07/2011 344.0 596.0 -4.97 26.20 -10.30 44.40 0.21 30.40 -0.14 2.53 -1.15 3.02 0.01 5.43 12/12/2011 -1520.0 871.0 4.88 9.52 8.49 19.80 -5.18 11.70 -0.33 0.97 0.04 1.05 -1.02 2.38 03/07/2011 252.0 573.0 6.73 15.40 -6.95 30.60 -12.90 17.40 0.46 1.57 0.03 1.82 -0.88 4.23 06/13/2011 145.0 625.0 -0.86 21.40 58.70 47.10 2.15 29.20 -2.43 2.29 0.77 2.60 1.15 5.07 09/26/2011 384.0 846.0 6.42 19.80 42.90 44.30 -7.12 22.80 0.36 1.99 -0.73 2.08 -0.31 4.34 12114/2011 -3150.0 813.0 14.00 15.20 21.40 24.80 5.33 18.50 1.05 1.36 -1.25 1.59 -0.31 3.82 03/09/2011 247.0 517.0 5.64 15.00 14.00 28.00 -9.32 18.00 0.01 1.63 -1.29 1.61 -3.05 3.49 06/13/2011 992.0 670.0 13.90 24.60 -8.31 40.10 1.66 28.60 2.50 2.44 -0.24 2.60 1.39 5.42 09/26/2011 380.0 631.0 -22.70 22.80 -15.50 27.30 20.80 23.90 -2.35 2.38 1.44 2.58 0.53 4.45 12/14/2011 -2930.0 809.0 0.10 10.90 -0.72 17.90 -18.80 14.00 0.14 1.00 -0.01 1.13 1.39 2.36 03/09/2011 254.0 576.0 5.06 16.10 27.90 28.00 0.66 19.80 -2.70 1.65 0.45 1.65 2.28 3.71 06/08/2011 -138.0 455.0 6.27 8.09 51.40 44.70 3.20 11.20 -0.02 0.75 0.17 0.83 -0.19 2.05 09/26/2011 413.0 629.0 -8.30 28.70 28.10 54.40 -3.06 28.30 -3.29 3.26 -1.83 3.70 2:50 7.09 12/12/2011 -2910.0 822.0 -3.34 11.30 -4.59 19.40 8.80 14.20 0.24 1.07 -0.37 1.15 -2.18 2.61 3-25

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 10 WELL WATER (pCi/I)

COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125

(*/-) *-

03/09/2011 0.75 1.47 -7.09 3.45 -0.31 1.85 1.14 3.21 -0.22 2.18 -1.99 15.20 3.13 4.35 06122/2011 -0.02 3.28 -0.89 9.30 -1.70 4.29 2.90 6.63 -3.03 4.31 -26.10 32.50 -3.01 9.33 09/14/2011 -0.62 1.83 -1.63 4.97 -0.18 2.25 -2.25 3.94 -0.03 2.49 1.26 18.40 12/12/2011 -2.13 4.19 -3.78 11.30 2.68 4.76 4.07 6.80 -0.21 4.39 -18.30 37.40 0.69 10.20 03/09/2011 -1.78 1.70 -1.04 3.03 -0.19 1.63 0.49 2.91 0.95 2.05 14.00 13.90 -4.31 4.15 06/08/2011 -0.04 0.81 0.06 1.73 0.02 1.16 1.88 1.91 -0.16 1.18 5.37 8.51 0.08 2.36 09/07/2011 0.70 2.43 1.27 5.78 3.09 3.66 3.01 5.06 0.97 3.26 16.80 23.20 -2.19 7.56 12/12/2011 0.53 1.07 1.75 2.50 1.49 1.25 -0.60 2.12 1.19 1.76 -6.51 10.40 1.99 3.36 03/08/2011 -1.28 1.37 -1.71 3.64 -1.16 1.68 1.25 2.89 -0.74 1.84 -5.89 13.10 -1.17 3.58 06/07/2011 0.42 0.69 -0.03 1.42 0.39 0.81 -1.97 1.74 0.01 1.13 0.56 6.24 0.57 1.82 09/20/2011 -1.57 2.74 2.77 6.98 5.97 4.16 4.96 5.14 0.12 3.40 5.07 27.90 4.38 9.73 12/08/2011 -1.19 3.31 0.64 6.46 2.22 3.75 -0.45 6.22 0.49 3.52 -2.12 30.10 -1.66 10.20 03/08/2011 -0.03 1.40 0.10 3.10 1.14 1.70 -1.14 2.74 0.51 1.95 3.62 12.60 -0.57 4.04 06/07/2011 0.02 0.68 -1.08 1.20 -0.93 0.75 1.07 1.31 -1.18 0.96 -1.73 4.97 -0.659 1.560 09/20/2011 -1.36 3.90 1.99 9.29 10.80 4.79 1.46 6.86 -1.74 4.29 -26.60 35.00 0.347 11.700 12/08/2011 -1.27 3.54 1.39 7.92 7.24 4.40 3.12 3.87 0.85 3.61 -11.80 30.70 -3.260 10.400 03/08/2011 -0.69 1.29 -1.24 2.70 -0.69 1.53 -0.08 2.75 -2.20 1.98 5.12 13.20 0.82 3.77 06/07/2011 0.00 0.65 0.17 0.93 0.75 1.03 1.16 1.55 -0.20 1.02 0.08 6.00 2.36 2.25 09/22/2011 -0.87 3.26 0.86 6.20 1.05 2.94 -1.61 4.37 -1.01 3.17 -12.10 26.30 -4.22 8.31 12/08/2011 0.31 3.82 0.19 7.22 2.90 4.19 1.96 6.00 -0.96 4.27 -1.28 33.10 -2.58 10.80 03/07/2011 -0.07 1.13 -2.09 2.38 0.39 1.31 0.45 2.25 -1.01 1.54 -4.72 11.20 -0.85 3.20 06/08/2011 0.06 0.97 -0.06 1.33 0.07 0.83 -0.48 1.67 -0.44 1.00 -3.53 7.13 -0.89 1.86 09/07/2011 -2.59 2.65 -4.74 5.59 1.38 3.05 0.17 5.62 -2.87 3.38 8.24 22.30 1.27 7.52 12/12/2011 0.37 0.96 -6.52 2.21 0.41 1.09 1.31 1.86 -0.84 1.44 -6.42 8.67 -1.14 2.53 03/07/2011 1.28 1.66 -8.78 4.14 0.43 1.91 -2.11 3.16 -2.29 2.15 -16.10 14.10 -1.46 4.07 06/13/2011 -0.66 2.57 -0.93 4.79 -2.38 2.85 -2.23 4.76 -1.63 3.12 -0.01 20.80 -3.29 6.54 09/26/2011 -0.50 1.94 2.58 4.11 1.24 2.29 0.43 3.66 -2.25 2.40 -12.70 16.90 0.55 5.66 12/14/2011 0.09 1.36 -0.01 3.24 1.80 1.68 3.53 2.99 0.25 2.03 5.76 13.40 0.88 3.93 03/09/2011 -0.50 1.39 -1.06 3.71 1.96 1.77 1.69 2.87 -0.99 2.00 -1.52 14.10 -2.11 4.20 06/13/2011 1.89 2.08 -5.30 5.41 -1.02 3.00 -0.04 4.95 -0.17 3.01 10.80 21.50 1.90 6.64 09/26/2011 0.57 2.21 2.41 5.41 5.45 3.06 0.74 3.90 -1.76 2.74 -6.55 19.80 3.15 7.37 12/14/2011 1.14 0.98 1.42 2.32 1.88 1.38 -1.94 1.97 1.42 1.44 -1.36 10.20 -3.42 3.10 82 03/09/2011 1.31 1.53 -7.98 3.73 1.88 1.91 -0.59 3.15 -1.27 2.05 5.44 13.20 2.16 4.26 82 06/08/2011 -0.23 0.69 -0.67 1.28 0.45 0.83 0.00 0.00 -0.53 0.99 1.28 7.19 0.69 2.12 82 09/26/2011 0.81 3.92 3.65 7.31 5.15 4.35 -1.53 6.25 0.18 3.61 -3.02 30.70 -0.28 9.01 82 12/12/2011 -0.34 1.05 1.07 2.46 -0.70 1.27 -0.97 2.14 -1.63 1.53 2.34 10.20 -1.27 3.05 3-26

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 10 WELL WATER (pCi/I)

COLLECTION

.9LOCATIO..N

.___-DATE_. 1-131 ................ CS-134 ...... Cs-137 Ba-140 La-140 Th-232 decay chain*

(+/-) (+/-) (+/-)

71 03/09/2011 1.85 7.30 -0.07 1.73 -1.03 2.00 -1.87 14.30 2.38 4.31 6.26 4.58 71 06/22/2011 1.43 7.62 1.13 3.75 1.97 4.11 -7.68 19.90 -10.60 8.01 1.84 13.70 71 09/14/2011 3.42 5.84 -0.36 2.44 -1.26 2.09 -12.10 13.90 0.34 4.44 -0.54 4.77 71 12/12/2011 2.51 8.75 2.38 4.09 -0.61 4.49 27.30 24.10 5.22 6.85 -11.30 14.40 03/09/2011 -1.28 7.49 0.71 2.26 1.08 1.55 -9.55 13.50 3.73 4.21 1.31 6.27 06/08/2011 -5.81 8.71 0.53 0.80 0.13 1.03 4.08 13.60 -0.33 3.88 3.89 5.69 09/07/2011 -3.12 8.19 0.47 3.02 -1.27 2.56 -8.69 16.20 -3.56 4.63 7.08 8.38 12/12/2011 -0.39 6.03 0.23 1.26 0.19 1.14 -5.42 10.50 0.42 3.29 2.66 4.86 03/08/2011 1.75 6.47 -2.99 1.54 -0.48 1.45 -12.20 12.80 -3.97 4.70 2.97 6.60 06/07/2011 -1.11 7.70 -0.23 0.64 -0.15 0.68 0.65 9.35 1.70 2.44 -3.50 4.71 09/20/2011 -2.62 5.70 -0.25 3.41 -2.00 3.32 -2.72 15.30 2.21 5.33 7.61 6.83 12/08/2011 -1.69 5.08 -0.61 3.66 0.59 4.02 6.22 16.90 -0.69 4.48 1.01 8.23 03/08/2011 -6.03 7.37 0.38 1.57 0.36 1.54 0.88 13.30 -2.49 4.46 4.19 3.40 06/07/2011 0.35 7.73 -0.06 0.55 -0.24 0.69 2.74 9.28 -0.47 2.76 -4.42 2.20 09/20/2011 0.82 7.01 0.75 4.41 -1.16 4.08 -5.16 19.10 -1.30 5.61 5.80 8.09 12/08/2011 -0.93 5.02 -0.40 3.66 -4.86 3.75 -14.20 16.10 0.49 5.00 -4.06 8.00 03/08/2011 2.76 7.30 -0.66 1.54 0.51 1.41 4.88 13.60 -0.72 3.92 1.52 9.98 06/07/2011 2.41 7.94 -0.13 0.62 0.35 0.72 7.83 10.90 0.20 2.19 -5.23 2.40 09/22/2011 1.99 4.26 0.21 2.99 -0.46 3.01 5.02 14.10 -3.02 5.70 4.36 6.73 12/08/2011 -1.76 5.20 -1.55 4.10 -0.75 4.32 -2.75 16.80 -2.20 4.40 1.37 8.60 03/07/2011 1.81 6.03 -0.24 1.39 -0.03 1.21 0.62 11.00 -1.86 3.28 5.83 8.47 06/08/2011 1.85 7.14 -0.39 0.63 0.06 0.72 1.87 10.70 1.36 3.27 -5.36 2.34 09/07/2011 4.52 7.79 0.62 2.72 -0.40 2.85 -8.34 17.00 -4.17 6.54 -5.07 5.33 12112/2011 0.04 4.34 0.69 1.11 -1.16 1.22 -0.40 8.87 -0.60 2.87 0.64 2.41 03/07/2011 5.99 7.24 -1.27 1.70 0.54 1.65 4.18 15.00 -2.08 4.91 0.66 2.69 06/13/2011 -7.64 8.49 0.38 2.69 -1.01 2.41 -0.37 16.40 -1.40 4.42 2.00 5.92 09/26/2011 -1.57 8.92 -0.87 2.21 -0.25 2.05 3.33 16.80 4.47 5.33 2.09 4.25 12/14/2011 -2.02 7.93 0.14 1.63 0.87 1.47 -13.80 13.80 0.82 4.23 1.31 6.09 03/09/2011 0.51 7.42 -0.79 1.58 -0.90 1.50 1.51 13.60 -1.93 4.46 4.13 3.36 06/13/2011 -0.10 8.44 -0.94 2.72 0.44 2.67 0.78 18.00 -2.08 5.10 11.50 12.30 09/26/2011 -0.69 5.19 0.53 2.52 0.26 2.63 -4.42 13.10 -0.54 4.32 15.50 5.67 12/14/2011 -3.55 4.57 0.16 1.33 0.14 1.09 2.16 8.83 0.69 2.53 2.55 2.81 82 03/09/2011 6.61 8.01 0.27 1.97 0.17 1.73 -9.74 15.60 0.63 4.96 0.61 6.36 82 06/08/2011 -4.66 7.06 0.52 0.63 -0.03 0.80 2.26 10.60 2.28 3.24 5.77 6.08 82 09/26/2011 -1.62 6.41 1.77 3.44 -1.05 3.45 -3.76 17.50 -1.07 6.02 14.40 7.03 82 12/12/2011 1.13 5.47 0.48 1.26 0.05 1.17 -0.82 10.20 -2.80 3.22 1.11 7.43

• The highest result for Th-228 and Act-228 is reported.

3-27

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 10 WELL WATER (pCi/I)

COLLECTION LOCATION DATE H-3 Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 83 03/16/2011 -71.7 625.0 15.90 17.70 20.80 25.30 12.40 15.60 0.29 1.40 -0.52 1.49 0.36 3.18 83 06/15/2011 135.0 623.0 4.44 29.10 3.35 44.60 -27.00 36.50 -3.02 2.85 -4.31 3.31 2.02 5.76 83 09/12/2011 -19.3 452.0 4.53 10.20 57.10 24.20 0.07 1.14 -1.16 1.20 1.97 2.60 83 12/12/2011 211.0 265.0 2.80 10.70 -3.65 20.00 -7.76 13.80 -1.95 1.09 -0.47 1.22 1.77 2.64 84 03/21/2011 402.0 633.0 1.58 22.50 49.60 38.40 -2.98 28.80 -0.45 2.40 0.76 2.93 0.28 4.91 84 06/15/2011 361.0 638.0 2.40 27.70 32.00 49.10 -11.00 33.70 -0.86 2.79 1.37 3.32 0.27 6.97 84 09/12/2011 -153.0 452.0 4.53 10.20 57.10 24.20 0.07 1.14 -1.16 1.20 1.97 2.60 84 12/12/2011 -2550.0 835.0 -12.90 31.60 -47.30 54.60 -18.30 38.00 0.90 3.02 -0.90 3.66 -5.47 8.50 85 03/14/2011 -10.2 625.0 -6.37 13.30 11.10 23.20 -1.46 16.90 -1.44 1.44 -2.13 1.51 -1.08 3.12 85 06/20/2011 -19.9 993.0 -1.56 34.30 8.18 61.50 2.87 41.80 0.40 4.22 -0.02 3.80 -0.18 7.83 85 09/27/2011 298.0 628.0 9.18 29.80 2.37 71.70 6.17 33.60 -0.48 3.38 -2.71 3.58 -0.47 6.15 86 03/14/2011 624.0 661.0 0.18 12.60 37.30 29.60 -2.46 16.40 -0.44 1.33 -0.22 1.37 1.68 3.06 86 06/20/2011 942.0 1080.0 -13.00 30.10 -7.33 48.10 -9.54 33.80 0.52 2.39 0.78 3.32 -0.41 5.47 86 09/27/2011 447.0 636.0 11.40 29.80 24.50 55.00 -17.10 32.30 -0.40 3.23 -2.74 3.66 2.73 6.40 86 12/21/2011 139.0 645.0 9.41 11.10 1.09 19.00 4.12 14.90 -0.16 1.05 -0.53 1.15 1.45 2.62 91 03/07/2011 -62.4 515.0 5.57 16.20 -5.58 26.90 -11.90 21.20 -0.38 1.59 0.12 1.71 2.30 3.79 91 06/15/2011 243.0 625.0 -2.31 26.20 35.50 50.70 -2.95 30.50 -0.35 2.52 -3.04 2.85 -2.10 5.50 91 09/14/2011 34.6 541.0 -6.89 11.00 -15.00 26.30 0.28 1.08 0.35 1.24 1.36 2.87 91 12/14/2011 -3210.0 799.0 0.92 11.30 -13.10 19.50 1.58 13.10 -0.31 1.16 -1.19 1.16 1.15 2.69 92 03/07/2011 392.0 582.0 -12.00 14.90 19.60 34.40 3.46 20.10 -0.79 1.45 0.59 1.80 -0.25 3.73 92 06/13/2011 69.5 616.0 2.06 30.30 76.60 59.20 13.40 32.90 1.00 2.90 -2.53 3.60 0.39 7.93 92 09/26/2011 10.2 812.0 -1.39 20.50 7.48 30.80 -30.20 26.60 0.23 2.09 0.00 0.00 -2.23 4.71 92 12/14/2011 -993.0 901.0 8.24 10.80 -9.76 22.20 -1.50 12.40 -0.16 1.14 0.50 1.25 2.88 2.83 3-28

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 10 WELL WATER (pCi/I)

COLLECTION LOCATION DATE Co-60(.1-) Zn-65(,1-) Nb-95(+--) Zr-95 Ru-103 Ru-106 Sb-125 83 03/16/2011 1.16 3.79 0.35 1.33 -6.80 2.91 2.25 1.51 1.04 2.68 -1.03 1.73 -3.57 12.80 83 06/15/2011 6.06 9.03 0.48 2.45 5.99 6.63 0.96 3.95 -4.56 6.17 0.08 3.72 -18.50 25.10 83 09/12/2011

-0.65 1.04 -1.78 2.74 1.15 1.34 1.95 2.09 -1.87 1.36 4.70 10.10 83 12/12/2011 0.04 1.35 0.54 2.47 1.63 1.23 1.38 2.15 -0.89 1.61 -4.53 9.60 -0.32 3.04 84 03/21/2011 0.42 2.29 -3.12 5.47 0.03 2.68 -1.24 4.87 0.45 2.93 -8.40 20.70 1.24 7.08 84 06/15/2011 -0.30 2.96 1.76 5.47 0.49 3.30 3.68 5.70 -2.06 3.60 6.99 23.80 4.56 7.83 84 09/12/2011 -0.65 1.04 -1.78 2.74 1.15 1.34 1.95 2.09 -1.87 1.36 4.70 10.10 -0.61 2.44 84 12/12/2011 -1.57 4.21 2.93 6.09 3.86 3.98 0.43 6.36 -0.94 3.99 -3.32 29.50 -16.60 9.09 85 03/14/2011 -0.31 1.28 0.38 3.04 3.94 1.78 0.79 2.67 -0.60 1.93 0.05 11.50 2.03 3.69 85 06/20/2011 0.92 3.60 7.40 6.93 -0.86 4.30 -3.70 6.72 -1.30 4.01 -22.00 33.60 8.59 10.60 85 09/27/2011 0.40 3.66 -3.61 8.42 9.84 4.24 0.20 5.45 -2.41 3.55 -6.56 31.50 9.49 10.60 86 03/14/2011 0.70 1.27 -0.70 3.24 1.03 1.51 -2.47 2.60 -3.06 1.64 -1.94 11.80 -0.98 3.55 86 06/20/2011 -0.87 3.39 2.96 6.16 0.07 4.01 -1.82 5.51 2.22 4.11 -17.10 29.60 5.11 9.41 86 09/27/2011 1.28 3.31 2.53 9.01 7.05 4.53 -1.94 6.04 -4.51 3.88 7.99 27.80 -6.84 9.84 86 12/21/2011 -0.27 1.03 -4.63 2.38 1.01 1.19 0.53 2.06 -0.32 1.65 1.96 9.72 -0.82 3.15 91 03/07/2011 -0.49 1.48 -4.99 3.29 1.86 1.83 -1.47 3.06 -0.64 2.14 2.13 14.10 4.46 4.61 91 06/15/2011 1.29 2.84 1.68 6.05 2.11 2.94 -0.30 4.68 4.15 3.51 8.27 23.60 8.76 7.69 91 09/14/2011 0.21 1.15 -5.84 2.71 0.46 1.27 2.34 2.05 -1.10 1.52 5.02 10.40 0.02 3.21 91 12/14/2011 -0.44 1.13 -3.00 2.48 1.08 1.28 1.93 2.13 -2.07 1.55 -10.00 10.30 0.20 2.94 92 03/07/2011 -0.63 1.63 -1.82 3.41 -0.22 1.78 -0.13 2.98 -0.38 1.99 2.17 14.00 -1.86 4.33 92 06/13/2011 2.14 2.86 5.70 7.20 0.01 3.68 -4.76 6.11 -0.95 3.53 -3.68 27.00 5.96 8.02 92 09/26/2011 -0.64 1.95 0.98 4.09 2.23 2.40 -0.68 3.72 -0.46 2.50 3.00 18.00 1.60 5.70 92 12/14/2011 1.62 1.21 -0.24 2.96 -0.26 1.34 0.93 2.26 -0.73 1.67 3.60 10.20 1.51 3.04 3-29

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 10 WELL WATER (pCi/I)

COLLECTION LOCATION DATE 1-13 1 Cs-i 34 Cs-137 Ba-140 La-i 40 Th-232 decay chain*

83 03/16/2011 0.93 4.55 -1.28 1.49 -0.82 1.72 -1.42 10.40 2.01 3.33 1.99 2.99 83 06/15/2011 -3.13 9.17 1.45 3.02 -1.39 2.91 -10.50 21.40 0.91 5.69 -10.50 12.00 83 09/12/2011 3.52 3.94 -0.92 1.19 -0.57 1.11 -3.88 8.84 -2.57 3.09 17.70 12.60 83 12/12/2011 -0.11 5.20 0.55 1.19 -0.31 1.14 -11.20 9.60 -0.28 3.22 1.50 5.34 84 03/21/2011 2.35 7.82 0.93 2.59 0.30 2.69 0.25 18.60 -1.97 5.33 0.62 7.62 84 06/15/2011 -0.39 9.12 -0.48 3.16 -2.38 2.96 10.30 20.70 0.22 6.23 4.66 7.44 84 09/12/2011 3.52 3.94 -0.92 1.19 -0.57 1.11 -3.88 8.84 -2.57 3.09 1.35 2.42 84 12/12/2011 -0.38 8.16 0.80 3.21 -4.20 3.94 7.18 21.20 -2.66 5.26 -8.17 12.80 85 03/14/2011 4.38 5.38 0.68 1.41 -0.98 1.64 -3.03 10.60 0.50 3.55 1.18 2.68 85 06/20/2011 -5.39 9.46 0.66 3.70 -2.45 3.91 8.72 23.60 0.79 7.54 6.75 14.50 85 09/27/2011 -0.54 6.43 0.59 3.57 3.18 3.48 9.52 17.40 2.05 5.64 17.40 8.68 86 03/14/2011 2.25 5.50 -0.53 1.45 -0.64 1.34 6.30 10.30 0.66 3.30 3.37 3.27 86 06/20/2011 -2.32 8.72 2.05 3.25 1.61 3.24 4.87 18.40 -5.16 6.33 17.80 13.70 86 09/27/2011 -0.28 6.44 2.49 4.13 -2.73 3.81 -11.10 17.20 5.79 6.17 13.40 8.62 86 12/21/2011 -4.51 6.47 -0.08 1.15 -0.27 1.10 4.36 10.60 -0.36 3.42 1.27 5.52 91 03/07/2011 -1.78 9.01 -1.06 1.93 0.82 1.59 -10.60 15.70 5.69 4.74 7.35 3.85 91 06/15/2011 2.28 8.48 1.15 2.95 -0.67 2.80 -7.84 19.00 0.24 4.99 8.83 7.12 91 09/14/2011 1.26 3.96 0.16 1.26 -0.43 1.29 -3.36 8.88 -1.20 2.64 2.24 3.24.

91 12/14/2011 -3.75 4.53 0.00 1.21 0.07 1.23 -6.98 9.10 -1.17 2.97 0.40 5.00 92 03/07/2011 -6.01 8.34 -0.10 1.63 -1.04 1.60 -3.26 14.00 0.14 4.39 2.66 3.95 92 06/13/2011 0.74 8.90 -0.86 3.41 -2.28 3.07 -6.76 21.10 -5.36 7.33 4.80 5.38 92 09/26/2011 -7.08 9.05 0.02 2.10 -0.48 2.30 2.53 17.70 4.97 5.22 2.03 4.53 92 12/14/2011 0.66 4.27 -0.07 1.18 -0.85 1.19 1.23 9.47 -0.09 3.14 1.05 2.16

• The highest result for Th-228 and Act-228 is reported.

3-30

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 11 RESERVOIR WATER or DEER MEAT Reservoir water and deer meat were not sampled in 2011. See discussion in Section 4.11.

3-31

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 12 FRUITS &VEGETABLES (pCi/g wet wt.)

LOCATION 25 DATE TYPE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 Co-60

(+--) (+--) (+--) (+--) (+--) (+--) (+--)

06/16/2011 Lettuce 0.451 0.193 3.000 0.442 0.045 0.116 0.006 0.013 -0.003 0.012 -0.013 0.027 0.001 0.013 06/23/2011 Strawberries 0.045 0.054 0.987 0.166 0.052 0.064 0.002 0.005 -0.006 0.005 -0.002 0.012 -0.003 0.005 0711412011 Lettuce 0.301 0.204 4.380 0.652 0.070 0.177 -0.011 0.020 -0.001 0.021 -0.007 0.044 -0.004 0.026 08/04/2011 Blueberries 0.207 0.126 1.470 0.310 -0.089 0.125 0.000 0.013 0.012 0.014 -0.014 0.024 0.010 0.013 08/10/2011 Lettuce 0.280 0.047 2.490 0.134 -0.032 0.048 0.002 0.006 -0.002 0.005 -0.004 0.012 -0.003 0.006 09/08/2011 Lettuce 0.832 0.061 2.930 0.146 -0.007 0.030 -0.001 0.003 -0.001 0.003 0.003 0.007 0.001 0.004 09/08/2011 Peaches 0.036 0.030 1.500 0.094 -0.004 0.021 0.000 0.003 0.002 0.003 0.003 0.006 0.000 0.003 DATE TYPE Zn-65 Nb-95 Zr-95 Ru-103 Ru-1 06 Sb-125 1-131

(+/-) (+/-) (+/-) (+/-) (+/-) -- --- (+7/_-)---- (,/-)

06/16/2011 Lettuce -0.004 0.026 0.009 0.012 0.024 0.021 0.006 0.013 -0.053 0.112 0.012 0.033 0.014 0.022 06/23/2011 Strawberries 0.011 0.011 0.010 0.008 -0.005 0.010 0.000 0.007 0.003 0.041 -0.002 0.013 -0.012 0.029 07/14/2011 Lettuce 0.015 0.053 0.030 0.022 0.018 0.032 -0.011 0.020 0.053 0.180 0.016 0.056 -0.003 0.032 08/04/2011 Blueberries 0.002 0.034 0.009 0.015 -0.008 0.025 0.000 0.014 0.014 0.130 -0.001 0.041 -0.007 0.022 08/10/2011 Lettuce 0.028 0.013 0.000 0.005 0.000 0.010 0.003 0.006 0.007 0.051 0.002 0.014 -0.003 0.010 09/08/2011 Lettuce -0.013 0.009 -0.003 0.004 -0.001 0.006 -0.004 0.003 -0.002 0.030 -0.001 0.009 -0.002 0.005 09/08/2011 Peaches -0.018 0.007 0.000 0.003 0.000 0.005 -0.001 0.003 0.021 0.023 0.000 0.007 0.003 0.004 DATE TYPE Cs-134 Cs-137 Ba-140 La-140 Ce-141 Ce-144 Th-232 decay chain*

06/16/2011 Lettuce 0.012 0.013 0.008 0.015 -0.017 0.054 -0.001 0.017 -0.011 0.021 -0.010 0.078 0.005 0.024 06/23/2011 Strawberries 0.000 0.005 -0.002 0.005 -0.005 0.049 0.005 0.016 0.007 0.011 -0.035 0.034 0.009 0.011 07/14/2011 Lettuce 0.003 0.021 -0.015 0.022 0.009 0.092 0.019 0.022 -0.013 0.034 0.021 0.141 0.077 0.078 08/04/2011 Blueberries -0.002 0.015 0.007 0.015 -0.020 0.061 -0.018 0.017 -0.003 0.023 -0.041 0.094 0.060 0.033 08/10/2011 Lettuce 0.018 0.012 0.006 0.006 0.011 0.027 0.000 0.008 0.008 0.008 -0.051 0.037 0.040 0.026 09/08/2011 Lettuce -0.002 0.004 0.003 0.004 0.005 0.015 -0.004 0.005 -0.001 0.005 0.010 0.019 0.030 0.019 09/08/2011 Peaches -0.001 0.003 0.001 0.003 -0.004 0.012 -0.003 0.004 -0.001 0.004 0.004 0.015 0.005 0.005

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-32

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 12 FRUITS &VEGETABLES (pCi/g wet wt.)

LOCATION 26 DATE TYPE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 Co-60

(+/-) (+/-) (+/-) (+/-) (+/-) (+/-) (+/-)

06/16/2011 Strawberries 0.137 0.101 5.900 0.614 -0.081 0.125 -0.008 0.014 0.002 0.012 0.013 0.033 0.004 0.017 06/16/2011 Spinach 0.138 0.138 1.800 0.393 0.027 0.127 -0.013 0.013 -0.002 0.015 0.009 0.021 0.006 0.014 07/14/2011 Lettuce 0.080 0.127 3.420 0.550 0.008 0.128 -0.001 0.018 0.007 0.019 0.005 0.039 0.011 0.021 08/10/2011 Lettuce 0.033 0.023 3.050 0.094 0.006 0.019 0.001 0.002 -0.002 0.002 -0.001 0.004 0.000 0.003 09/08/2011 Lettuce 0.008 0.019 1.430 0.087 0.009 0.021 -0.001 0.002 0.000 0.002 -0.004 0.005 0.002 0.003 09/08/2011 Apples 0.046 0.029 0.929 0.103 -0.021 0.029 0.003 0.003 0.001 0.003 -0.004 0.007 0.000 0.004 DATE TYPE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131 06/16/2011 Strawberries -0.031 0.033 0.007 0.016 0.009 0.024 0.005 0.013 -0.077 0.118 0.020 0.030 -0.005 0.025 06/16/2011 Spinach 0.017 0.034 -0.016 0.017 0.022 0.027 -0.010 0.014 -0.023 0.134 0.014 0.039 0.010 0.026 07/14/2011 Lettuce -0.003 0.040 0.010 0.020 -0.013 0.028 0.012 0.015 -0.050 0.127 0.016 0.043 -0.007 0.022 08/10/2011 Lettuce -0.006 0.005 0.002 0.002 -0.001 0.004 -0.001 0.002 0.012 0.017 -0.002 0.005 -0.001 0.004 09/08/2011 Lettuce 0.004 0.005 0.002 0.002 0.000 0.004 -0.001 0.002 -0.007 0.020 -0.001 0.006 -0.001 0.003 09/08/2011 Apples -0.004 0.009 0.000 0.003 -0.003 0.006 -0.003 0.003 -0.006 0.029 0.004 0.009 -0.004 0.005 DATE TYPE Cs-134 Cs-137 Ba-140 La-140 Ce-141 Ce-144 Th-232 decay chain*

06/16/2011 Strawberries 0.003 0.013 -0.009 0.013 0.008 0.068 0.008 0.018 0.018 0.022 0.072 0.084 0.000 0.024 06/16/2011 Spinach 0.000 0.014 -0.004 0.014 0.001 0.072 0.005 0.019 -0.003 0.024 0.026 0.089 0.002 0.024 07/14/2011 Lettuce -0.002 0.016 -0.006 0.017 0.001 0.066 -0.023 0.022 0.010 0.025 0.024 0.107 0.022 0.030 08/10/2011 Lettuce -0.001 0.002 0.001 0.002 0.010 0.010 -0.002 0.003 0.005 0.006 -0.003 0.014 0.003 0.016 09/08/2011 Lettuce 0.000 0.003 0.001 0.003 -0.010 0.010 0.001 0.003 0.003 0.006 -0.003 0.015 0.007 0.006 09/08/2011 Apples 0.001 0.004 0.000 0.003 0.001 0.014 0.000 0.005 -0.001 0.005 -0.004 0.022 0.022 0.008

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-33

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 13 BROADLEAF VEGETATION (pCi/g wet wt.)

LOCATION 1 COLLECTION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 Co-60

(+/-) (+1-) (+/-) (+/-) (+1-) (+/-) (+1-)

05/24/2011 1.420 0.163 3.520 0.268 0.038 0.042 0.001 0.004 0.001 0.004 -0.004 0.010 0.000 0.004 06/21/2011 0.905 0.269 3.270 0.437 0.129 0.166 0.003 0.016 -0.002 0.016 0.020 0.039 -0.002 0.015 07/12/2011 1.050 0.305 4.100 0.614 0.115 0.153 0.000 0.016 0.003 0.015 0.012 0.032 -0.013 0.018 08/09/2011 1.350 0.183 4.920 0.435 -0.070 0.087 0.001 0.009 0.004 0.009 0.002 0.025 -0.001 0.011 09/26/2011 2.910 0.281 1.920 0.329 0.072 0.137 -0.012 0.012 0.010 0.013 0.014 0.026 -0.006 0.013 10/06/2011 3.490 0.413 2.900 0.502 -0.003 0.180 -0.016 0.017 -0.007 0.019 -0.015 0.035 -0.007 0.017 COLLECTION DATE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131 05/24/2011 0.002 0.008 -0.004 0.004 0.006 0.008 0.003 0.005 0.012 0.035 0.006 0.008 0.015 0.029 06/21/2011 -0.051 0.035 0.003 0.017 -0.016 0.027 0.012 0.018 0.175 0.138 0.036 0.039 -0.012 0.014 07/12/2011 -0.040 0.042 -0.010 0.018 0.033 0.024 0.005 0.016 0.077 0.163 -0.025 0.042 -0.023 0.029 08/09/2011 -0.018 0.026 -0.006 0.009 0.002 0.017 -0.002 0.009 0.015 0.086 -0.006 0.023 0.021 0.018 09/26/2011 -0.028 0.032 0.017 0.014 -0.002 0.021 0.005 0.014 0.053 0.110 0.008 0.035 0.014 0.030 10/06/2011 -0.030 0.047 0.007 0.018 0.008 0.033 -0.017 0.019 -0.171 0.177 -0.028 0.059 -0.009 0.031 COLLECTION

---

DATE _ ------ Cs-134 - -- Cs-137 - .Ba-140o . La-140 Ce-141 ------- Ce-144 Th-232 decay chain*

(+1- (+1-)

05/24/2011 0.002 0.003 0.005 0.004 0.002 0.047 -0.010 0.012 -0.008 0.008 0.017 0.019 0.015 0.016 06/21/2011 -0.015 0.017 0.020 0.017 0.151 0.120 0.007 0.027 -0.001 0.032 -0.015 0.096 0.000 0.053 07/12/2011 0.002 0.016 -0.009 0.015 0.014 0.068 0.005 0.020 -0.011 0.026 -0.006 0.104 0.067 0.045 08/09/2011 -0.020 0.010 0.015 0.011 -0.018 0.049 -0.011 0.015 -0.025 0.013 -0.022 0.049 0.044 0.044 09/26/2011 -0.001 0.015 0.007 0.013 0.020 0.071 0.009 0.020 -0.005 0.026 -0.024 0.090 0.096 0.052 10/06/2011 -0.036 0.021 -0.009 0.018 0.075 0.085 0.000 0.022 0.001 0.037 -0.061 0.134 0.061 0.075

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-34

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 13 BROADLEAF VEGETATION (pCi/g wet wt.)

LOCATION 10 COLLECTION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 Co-60

(+/-) (+/-) (+/-) (+/-) (+1-) (+/-) (+/-)

05/24/2011 0.942 0.144 3.060 0.242 0.022 0.042 0.002 0.003 -0.010 0.004 0.002 0.010 -0.001 0.004 06/21/2011 0.410 0.280 4.720 0.538 -0.047 0.184 0.002 0.014 0.004 0.018 0.004 0.035 0.005 0.017 07/12/2011 0.952 0.223 3.930 0.529 -0.047 0.146 0.000 0.015 -0.010 0.016 0.001 0.034 0.014 0.017 08/09/2011 1.000 0.137 5.340 0.357 -0.047 0.061 0.003 0.007 -0.004 0.007 -0.005 0.016 -0.001 0.010 09/26/2011 1.740 0.254 2.850 0.383 0.009 0.114 0.000 0.013 -0.010 0.014 -0.011 0.025 0.011 0.013 10/06/2011 2.350 0.335 2.630 0.539 -0.134 0.151 -0.009 0.016 -0.001 0.019 -0.010 0.027 0.001 0.016 COLLECTION DATE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131 05/24/2011 0.003 0.007 0.002 0.003 -0.002 0.007 -0.001 0.005 0.031 0.028 0.000 0.008 -0.019 0.028 06/21/2011 -0.035 0.037 0.005 0.017 0.014 0.030 0.006 0.018 -0.005 0.143 0.036 0.038 -0.012 0.013 07/12/2011 0.007 0.040 0.016 0.016 0.009 0.023 0.011 0.016 -0.011 0.135 0.021 0.042 0.008 0.030 08/09/2011 -0.024 0.020 -0.003 0.008 0.003 0.013 -0.003 0.007 0.037 0.063 0.009 0.019 0.004 0.014 09/26/2011 0.004 0.031 0.019 0.017 -0.021 0.020 0.002 0.014 -0.046 0.108 -0.006 0.034 -0.015 0.032 10/06/2011 0.019 0.037 0.008 0.014 0.027 0.029 0.000 0.016 0.099 0.142 -0.023 0.042 -0.025 0.029 COLLECTION DATE Cs-134 Cs-137 Ba-140 La-140 Ce-141 Ce-1.44 Th-232 decay chain*

05/24/2011 0.000 0.003 0.005 0.004 -0.006 0.043 0.004 0.012 0.006 0.007 0.003 0.020 0.013 0.018 06/21/2011 -0.001 0.017 0.024 0.017 0.087 0.113 -0.011 0.024 0.013 0.031 -0.045 0.104 0.016 0.041 07/12/2011 0.013 0.014 0.008 0.016 0.010 0.072 0.006 0.021 0.004 0.028 -0.037 0.101 0.048 0.031 08/09/2011 -0.008 0.006 0.014 0.010 -0.019 0.038 -0.006 0.011 -0.009 0.011 -0.019 0.043 0.100 0.046 09/26/2011 0.008 0.013 0.005 0.014 -0.002 0.072 -0.020 0.023 -0.008 0.022 -0.017 0.082 0.052 0.027 10/06/2011 0.001 0.019 -0.002 0.017 0.006 0.076 0.000 0.013 -0.027 0.030 0.063 0.130 0.065 0.122

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-35

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 13 BROADLEAF VEGETATION (pCi/g wet wt.)

LOCATION 17 COLLECTION DATE Be-7(+/-) K-40(+/-) Cr-51(+/-) Mn-54(+/-) Co-58(+/-) Fe-59(+/-) Co-60(+/-)

05/24/2011 1.500 0.159 2.950 0.236 0.014 0.043 0.002 0.004 -0.001 0.003 0.006 0.009 -0.002 0.003 06/21/2011 1.150 0.298 2.610 0.418 -0.013 0.191 -0.004 0.014 -0.015 0.015 0.008 0.037 0.002 0.016 07/12/2011 1.270 0.297 3.840 0.595 0.139 0.182 0.013 0.017 0.007 0.016 -0.009 0.038 0.014 0.019 08/09/2011 1.590 0.146 5.700 0.325 -0.012 0.071 0.003 0.007 -0.004 0.007 0.009 0.017 -0.001 0.009 09/26/2011 4.210 0.361 2.060 0.376 -0.012 0.137 -0.010 0.012 -0.003 0.012 0.005 0.023 0.006 0.011 10/06/2011 5.760 0.470 2.660 0.444 0.013 0.194 -0.003 0.017 -0.017 0.017 0.042 0.032 -0.002 0.019 COLLECTION DATE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131 05/24/2011 -0.006 0.007 0.001 0.003 -0.004 0.006 0.001 0.004 -0.013 0.027 -0.001 0.007 -0.012 0.028 06/21/2011 -0.051 0.040 -0.004 0.017 -0.016 0.025 0.009 0.020 -0.048 0.139 -0.019 0.042 0.009 0.014 07/12/2011 -0.056 0.048 0.006 0.020 -0.007 0.030 -0.008 0.019 -0.027 0.150 0.015 0.049 0.024 0.032 08/09/2011 -0.012 0.019 0.009 0.007 0.007 0.013 -0.001 0.008 -0.034 0.064 0.001 0.020 0.000 0.016 09/26/2011 0.003 0.025 0.005 0.013 0.005 0.020 -0.001 0.014 0.013 0.106 0.029 0.037 -0.021 0.032 10/06/2011 0.018 0.036 0.004 0.017 -0.008 0.029 0.010 0.020 0.025 0.164 -0.002 0.055 -0.006 0.034 COLLECTION DATE Cs-i 34 Cs-i 37 Ba-140 La-140 Ce-141 Ce-144 Th-232 decay chain*

05/24/2011 0.001 0.003 0.070 0.014 -0.009 0.046 -0.001 0.008 -0.004 0.009 -0.012 0.019 0.026 0.039 06/21/2011 0.002 0.016 0.019 0.018 0.085 0.124 0.002 0.041 -0.019 0.034 0.018 0.102 0.062 0.064 07/12/2011 0.001 0.020 -0.012 0.020 -0.056 0.087 0.008 0.024 0.021 0.030 0.038 0.118 0.047 0.189 08/09/2011 -0.007 0.008 0.001 0.007 0.024 0.041 0.009 0.011 0.002 0.014 -0.015 0.050 0.029 0.031 09/26/2011 0.001 0.014 0.069 0.034 0.065 0.070 -0.002 0.017 -0.004 0.025 0.043 0.099 0.123 0.052 10/06/2011 0.005 0.018 0.045 0.027 0.088 0.089 -0.034 0.022 -0.012 0.039 0.057 0.149 0.198 0.075

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-36

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 14 SEA WATER (pCi/I)

LOCATION 32 DATE H-3 Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

(+/-) (+/-) (+/-) (+1-) (+1-) (+/-) (+1-)

01/25/2011 381 178 3.51 19.30 306 68 0.54 2.50 0.08 2.30 -0.37 5.62 02/22/2011 250 106 13.90 25.00 271 69 -14.40 30.50 -1.17 2.53 0.49 2.77 -2.98 5.86 03/29/2011 483 130 -17.80 22.20 310 63 -27.50 29.10 -0.53 2.31 -2.36 2.50 -3.25 5.34 04/26/2011 931 157 9.44 8.88 275 27 8.96 11.80 0.28 0.74 -0.05 0.96 -0.60 2.07 05/26/2011 214 119 5.93 8.48 271 49 1.76 10.30 0.28 0.65 0.07 0.65 0.10 1.89 06/28/2011 428 130 4.57 21.10 228 61 5.48 26.10 -0.70 1.87 -1.63 2.42 0.53 4.68 07/26/2011 522 132 12.70 32.50 211 135 5.84 36.90 5.20 3.67 0.17 4.07 -0.89 9.04 08/30/2011 421 128 9.67 30.00 242 87 17.30 29.90 -1.71 2.94 3.99 3.16 0.45 6.40 09/27/2011 1130 182 -3.77 22.30 262 61 -17.00 24.80 1.49 2.14 0.20 2.52 0.95 5.70 10/25/2011 2260 287 24.00 35.60 267 94 -2.55 39.40 2.83 3.74 -2.84 4.70 -6.28 9.29 11/29/2011 299 176 19.40 36.00 234 89 3.97 34.30 3.08 3.89 2.75 3.94 -1.42 7.71 12/27/2011 65 112 3.12 25.10 289 63 -6.12 31.00 -0.59 2.60 0.04 2.42 5.00 5.74 DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 S-J-125

(+/-) (+/-) (+/-) (+/-) (+/-) (+/-) (+/-)

01/25/2011 1.79 2.83 -1.91 6.28 2.05 2.73 -0.66 4.27 -0.25 2.73 0.44 22.10 02/22/2011 0.79 3.10 -0.73 5.80 0.28 2.86 1.98 5.06 -2.70 3.45 2.12 25.70 -3.46 8.18 03/29/2011 2.80 2.18 -3.86 5.74 2.45 2.61 1.84 4.07 0.40 2.86 -4.27 19.50 -1.79 6.18 04/26/2011 0.97 0.82 -0.87 1.85 -1.22 1.01 -0.14 1.77 0.07 1.20 -1.54 7.17 -0.94 2.02 05/26/2011 -0.09 0.78 0.70 1.87 0.05 0.90 0.53 1.73 0.07 1.10 3.89 6.51 1.73 2.10 06/28/2011 0.36 2.37 -3.28 5.01 0.72 2.45 -0.49 3.86 0.90 2.97 -8.00 19.00 -3.64 6.20 07/26/2011 -2.55 4.43 -2.27 9.35 -0.59 4.22 0.00 0.00 -1.10 5.14 8.37 38.20 -4.43 9.81 08/30/2011 0.20 3.22 -10.40 7.09 1.32 3.27 3.23 5.21 -2.06 4.08 -2.20 24.80 1.99 9.72 09/27/2011 -1.56 2.32 -4.99 5.43 0.89 2.34 -1.83 4.17 -2.51 2.73 -16.30 19.90 2.46 5.91 10/25/2011 -1.31 4.46 2.73 6.91 4.20 4.78 1.07 7.34 1.92 4.43 4.20 36.00 5.16 13.70 11/29/2011 -0.04 4.34 -0.81 10.00 -0.80 3.94 -1.38 7.21 0.63 4.20 35.00 32.80 3.14 9.84 12/27/2011 1.38 2.93 3.29 6.62 1.01 3.06 -0.71 4.64 0.96 3.44 -4.19 22.40 0.19 7.59 DATE -1131 Cs-134 Cs-137 Ba-140 La-140 Th-232 decay chain*

(+1-) (+/-) (+/-) (+/-) (+1-) (+/-)

01/25/2011 -1.05 4.84 -1.42 2.84 0.43 2.75 -9.18 12.80 -0.56 4.67 4.66 5.98 02/22/2011 5.05 6.89 -5.20 2.87 -1.25 2.82 -2.40 16.80 1.38 5.07 3.20 14.40 03/29/2011 -4.10 8.40 0.70 2.42 1.37 2.29 -11.70 18.00 -4.32 5.62 4.95 9.43 04/2612011 -9.98 8.43 -0.01 0.81 -0.68 1.00 -1.34 11.90 -2.81 3.81 1.39 2.34 05/26/2011 4.38 5.92 -0.15 0.66 0.59 0.78 -8.65 9.08 0.61 2.09 3.36 4.42 06/2812011 4.12 8.07 0.19 2.34 -0.04 2.09 8.82 17.10 0.50 5.19 4.78 9.01 07126/2011 -0.69 7.62 1.25 4.13 0.27 4.77 -20.00 20.90 1.05 7.76 3.37 6.47 08/30/2011 4.67 6.59 1.21 3.48 -0.56 3.32 -6.88 18.10 -1.55 4.64 10.50 11.90 09/2712011 2.80 8.06 -1.59 2.18 0.08 2.20 -12.30 15.90 -1.43 6.25 4.07 8.74 10/25/2011 3.28 7.30 -0.95 4.22 -4.98 4.40 12.30 22.40 0.20 6.52 3.19 8.44 11/29/2011 0.36 6.51 -1.78 4.73 1.84 4.14 7.31 18.60 3.79 7.74 1.74 15.20 12/27/2011 1.95 6.22 0.06 3.44 -2.39 3.07 3.18 16.50 0.50 4.56 2.29 6.04

• The highest result for Th-228 and Act-228 is reported.

3-37

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 14 SEA WATER (pCi/I)

LOCATION 37 DATE H-3 Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

(+/-) (+/-) (+/-) (+/-) (+/-) (+/-) (+/-)

03/08/2011 32 139 2.52 23.90 226 60 18.60 27.50 0.36 2.25 1.47 2.80 -0.71 5.82 06/07/2011 -87 84 -1.60 11.40 213 37 4.84 13.30 -0.92 1.23 0.02 1.32 1.94 3.19 08/30/2011 -23 103 -16.70 37.50 296 96 -1.48 41.20 1.48 3.90 -2.34 4.18 -0.43 6.55 12/06/2011 42 116 -4.23 30.00 295 69 -15.70 34.10 -0.84 2.85 1.65 3.17 -1.14 7.18 DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 03/08/2011 0.69 2.43 -0.11 5.46 -0.58 2.87 -0.14 5.42 -0.46 3.02 -2.72 23.80 3.28 6.96 06/07/2011 0.88 1.33 0.31 2.97 -0.04 1.34 0.76 2.42 -0.58 1.57 0.21 10.70 0.31 3.02 08/30/2011 1.05 3.80 -13.10 10.30 -1.59 4.08 0.60 6.68 2.00 4.45 35.20 35.60 -2.78 11.30 12/06/2011 0.32 3.22 -6.36 7.19 0.04 3.27 -0.49 4.68 -0.36 3.58 -7.06 26.90 -2.27 7.60 DATE

.... --- 1-131 ------ Cs-134 ------ Cs-1 37 ...... ......-Ba-140 .. .La-140 ..... Th-232 decay chain*

03/08/2011 -4.86 7.56 -4.63 2.84 -1.14 2.39 -13.40 18.20 2.72 5.03 12.70 8.73 06/07/2011 -1.14 5.30 -4.78 1.27 -0.69 1.18 6.17 10.70 -0.72 3.43 -0.85 2.41 08/30/2011 3.27 8.04 -5.76 5.29 -1.44 4.39 -5.44 23.40 -2.12 5.97 9.99 16.50 12/06/2011 -15.90 10.80 -2.41 3.15 -1.17 2.86 9.02 19.00 -0.59 6.98 2.75 11.30

• The highest result for Th-228 and Act-228 is reported.

3-38

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 15 BOTTOM SEDIMENT (pCi/g dry wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-558 Fe-59

(+0-)

(+1-)

( -)(+/-) (+/-)

29 06/27/2011 -0.309 0.278 6.27 0.86 -0.047 0.369 0.008 0.025 0.003 0.031 -0.020 0.063 11/22/2011 0.197 0.333 17.70 1.65 0.084 0.276 0.019 0.035 -0.002 0.038 0.064 0.091 03/02/2011 -0.114 0.250 16.30 1.21 -0.154 0.268 0.015 0.025 -0.028 0.025 0.009 0.067 08/31/2011 0.038 0.276 18.00 1.42 0.041 0.282 0.005 0.031 -0.019 0.033 -0.012 0.069 11/22/2011 0.195 0.337 15.40 1.65 -0.001 0.352 -0.004 0.044 0.017 0.038 -0.043 0.087 03/02/2011 -0.095 0.215 15.70 1.23 0.118 0.237 -0.016 0.026 0.010 0.027 0.002 0.071 08/31/2011 0.262 0.200 15.70 1.15 0.096 0.201 -0.009 0.026 -0.008 0.027 0.020 0.055 02/14/2011 -0.047 0.197 14.90 1.08 0.202 0.228 -0.006 0.021 0.005 0.025 0.011 0.061 08/31/2011 0.091 0.170 13.90 1.02 -0.065 0.172 -0.015 0.019 -0.007 0.021 0.000 0.050 06/27/2011 0.199 0.381 12.50 1.50 -0.231 0.516 0.011 0.045 0.010 0.049 0.013 0.115 12/20/2011 0.163 0.333 15.90 1.33 0.354 0.409 -0.015 0.034 -0.046 0.037 0.006 0.083 03/19/2011 0.239 0.219 13.90 0.96 0.101 0.256 -0.006 0.024 -0.011 0.026 -0.030 0.061 09/01/2011 0.233 0.170 14.40 1.01 -0.058 0.161 0.001 0.020 -0.009 0.021 -0.009 0.045 06/27/2011 0.018 0.835 16.90 2.61 0.519 1.020 0.047 0.077 -0.063 0.077 -0.247 0.209 12/14/2011 0.179 0.309 18.50 1.41 0.026 0.326 -0.003 0.036 -0.016 0.034 0.002 0.080 03/19/2011 0.070 0.206 18.30 1.22 0.043 0.273 -0.026 0.027 0.022 0.026 -0.012 0.066 09/01/2011 0.400 0.290 17.30 1.30 -0.041 0.231 -0.011 0.033 -0.016 0.032 -0.087 0.081 03/02/2011 -0.062 0.219 16.90 1.22 0.082 0.260 -0.006 0.026 -0.004 0.024 0.024 0.069 08/31/2011 0.026 0.192 17.90 1.15 0.065 0.197 0.010 0.023 -0.005 0.027 -0.035 0.058 3-39

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 15 BOTTOM SEDIMENT (pCi/g dry wt.)

COLLECTION LOCATION DATE Co-60

(+/-) Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 29 06/27/2011 0.003 0.032 -0.069 0.071 0.015 0.032 0.005 0.051 -0.006 0.033 -0.030 0.208 11/22/2011 0.058 0.053 -0.009 0.098 -0.003 0.043 0.014 0.065 -0.016 0.037 0.253 0.326 03/02/2011 0.013 0.034 0.001 0.070 0.003 0.029 -0.046 0.046 0.008 0.029 0.004 0.209 08/31/2011 0.017 0.043 0.064 0.075 -0.026 0.035 0.010 0.059 0.007 0.032 0.009 0.299 11/22/2011 -0.022 0.050 -0.077 0.089 -0.023 0.049 0.099 0.069 -0.006 0.041 -0.375 0.362 03/02/2011 0.003 0.036 -0.036 0.079 0.009 0.029 0.000 0.046 -0.005 0.026 0.050 0.216 08/31/2011 0.004 0.034 -0.029 0.071 0.021 0.026 -0.010 0.043 -0.003 0.025 -0.064 0.220 02/14/2011 -0.020 0.032 -0.017 0.073 0.022 0.027 0.037 0.044 -0.001 0.023 0.237 0.188 08/31/2011 -0.001 0.027 -0.095 0.056 -0.010 0.021 0.011 0.037 -0.005 0.020 -0.086 0.175 06/27/2011 0.026 0.050 -0.024 0.108 -0.001 0.053 0.037 0.073 0.015 0.047 -0.182 0.310 12/20/2011 -0.032 0.040 0.018 0.088 0.040 0.042 0.043 0.067 -0.014 0.041 0.155 0.288 03/19/2011 0.020 0.032 -0.030 0.065 0.014 0.026 -0.003 0.046 0.009 0.027 0.023 0.208 09/01/2011 0.012 0.028 -0.066 0.056 0.002 0.020 -0.003 0.037 0.008 0.019 -0.014 0.156 06/27/2011 0.019 0.104 -0.046 0.216 -0.026 0.092 0.022 0.155 -0.032 0.106 -0.153 0.666 12/14/2011 0.057 0.040 0.033 0.090 0.035 0.039 -0.011 0.063 0.021 0.039 -0.037 0.292 03/19/2011 -0.021 0.033 -0.010 0.066 -0.003 0.032 -0.016 0.048 0.000 0.027 -0.091 0.199 09/01/2011 -0.020 0.041 -0.132 0.086 -0.013 0.033 -0.011 0.056 -0.007 0.030 -0.105 0.252 03/02/2011 -0.049 0.031 -0.082 0.070 0.006 0.030 0.011 0.051 0.018 0.025 0.021 0.222 08/31/2011 0.044 0.030 -0.124 0.068 0.032 0.024 0.005 0.044 0.004 0.024 -0.059 0.192 3-40

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 15 BOTTOM SEDIMENT (pCi/g dry wt.)

COLLECTION

-LOCATION ---- DATE --- Ag-ib0M Sb-1125 ---- 1-131 ---- --- Cs-134 ------- Cs-137 --- Th-232 decay chain*-

(+/-) (+1-) (+/-) (+0-) (+--) (+0-)

29 06/27/2011 -0.017 0.027 0.034 0.068 -0.111 0.186 0.020 0.026 0.013 0.027 0.460 0.087 29 11/22/2011 0.016 0.036 -0.007 0.095 0.039 0.057 -0.011 0.036 0.066 0.037 1.550 0.124 31 03/02/2011 0.003 0.025 0.011 0.068 0.050 0.086 0.006 0.025 -0.017 0.026 0.696 0.174 31 08/31/2011 0.001 0.032 0.070 0.080 0.071 0.057 0.020 0.034 0.012 0.034 0.949 0.154 32 11/22/2011 -0.003 0.042 -0.038 0.098 -0.005 0.069 -0.016 0.044 0.001 0.048 1.220 0.120 33 03/02/2011 -0.002 0.024 0.017 0.058 0.049 0.080 0.000 0.028 -0.005 0.025 0.242 0.077 33 08/31/2011 -0.007 0.024 -0.021 0.066 -0.012 0.042 -0.007 0.024 0.033 0.028 0.350 0.075 34 02/14/2011 -0.018 0.022 0.015 0.054 -0.006 0.073 -0.013 0.024 0.002 0.023 0.182 0.100 34 08/31/2011 -0.007 0.019 0.032 0.052 -0.010 0.035 0.017 0.020 0.017 0.021 0.194 0.044 35 06/27/2011 -0.020 0.040 0.037 0.101 -0.020 0.224 0.006 0.037 0.010 0.046 0.919 0.228 35 12/20/2011 0.018 0.032 0.019 0.083 0.081 0.160 -0.010 0.036 0.014 0.034 1.190 0.101 37 03/19/2011 -0.006 0.022 0.003 0.057 0.013 0.088 0.005 0.027 0.014 0.024 0.206 0.048 37 09/01/2011 -0.001 0.018 0.035 0.050 0.011 0.035 -0.014 0.021 -0.002 0.020 0.209 0.082 39 06/27/2011 -0.028 0.090 -0.173 0.198 -0.131 0.481 0.036 0.081 0.129 0.091 0.931 0.240 39 12/14/2011 0.012 0.038 -0.132 0.094 0.009 0.066 -0.007 0.039 0.123 0.070 1.040 0.102 67 03/19/2011 -0.004 0.027 -0.030 0.066 0.023 0.095 -0.005 0.026 0.004 0.028 0.394 0.170 67 09/01/2011 0.008 0.030 -0.025 0.072 0.002 0.051 0.011 0.029 0.043 0.037 0.512 0.189 69 03/02/2011 -0.018 0.022 0.020 0.054 0.033 0.081 0.003 0.025 0.011 0.026 0.278 0.081 69 08/31/2011 -0.006 0.022 0.040 0.060 -0.007 0.044 -0.006 0.025 -0.003 0.023 0.249 0.086

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-41

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 16 AQUATIC FLORA - FUCUS (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

-0.00---2-0.0 29 03/23/2011 0.133 0.055 5.99 0.16 -0.027 0.039 -0.001 0.003 -0.002 0.004 0.007 0.010 29 06/07/2011 0.054 0.029 8.42 0.21 -0.011 0.037 0.000 0.002 0.002 0.003 -0.004 0.008 29 09/27/2011 0.236 0.031 6.68 0.08 -0.006 0.027 0.000 0.002 -0.001 0.002 -0.002 0.006 29 12/14/2011 0.127 0.111 6.54 0.56 -0.062 0.100 -0.004 0.011 0.000 0.012 0.014 0.029 32 03/23/2011 0.048 0.035 7.43 0.18 -0.019 0.040 0.001 0.004 -0.001 0.004 -0.011 0.010 32 05/25/2011 0.039 0.027 7.72 0.19 -0.014 0.035 0.002 0.002 0.012 0.004 -0.003 0.008 32 08/10/2011 0.064 0.076 7.53 0.46 -0.019 0.070 0.006 0.009 0.004 0.010 -0.010 0.023 32 11/07/2011 0.081 0.137 8.70 0.85 -0.026 0.146 0.012 0.017 0.003 0.015 0.041 0.045 33 02/14/2011 0.097 0.072 6.73 0.38 -0.002 0.069 0.009 0.009 0.013 0.009 -0.008 0.021 33 05/25/2011 0.113 0.047 6.51 0.14 0.019 0.035 0.001 0.002 -0.002 0.002 -0.001 0.006 33 08/20/2011 0.299 0.201 7.37 0.69 0.003 0.119 0.007 0.013 -0.002 0.014 -0.013 0.035 33 11/08/2011 0.145 0.133 6.35 0.62 0.098 0.121 0.000 0.014 0.004 0.014 -0.029 0.035 35 03/19/2011 0.086 0.058 8.08 0.22 -0.064 0.066 0.002 0.006 -0.001 0.007 -0.003 0.020 35 05/25/2011 0.198 0.074 7.40 0.18 -0.008 0.037 0.001 0.002 0.001 0.003 -0.003 0.008 35 08/20/2011 0.080 0.090 6.40 0.48 0.033 0.097 0.000 0.009 -0.003 0.010 0.001 0.022 35 11/08/2011 -0.075 0.153 6.99 0.77 0.059 0.148 0.009 0.016 0.001 0.015 0.007 0.035 36 03/19/2011 0.180 0.055 7.88 0.20 0.022 0.057 0.000 0.005 0.001 0.005 0.009 0.014 36 06/07/2011 0.152 0.055 7.03 0.17 -0.027 0.036 -0.001 0.002 0.000 0.002 0.002 0.006 36 09/28/2011 0.126 0.101 7.05 0.44 -0.098 0.112 -0.005 0.009 0.003 0.012 0.013 0.025 36 11/08/2011 -0.052 0.153 5.36 0.72 -0.110 0.124 0.005 0.018 -0.005 0.020 -0.042 0.044 90 02/14/2011 0.116 0.087 6.57 0.26 -0.005 0.054 0.001 0.005 -0.004 0.006 0.008 0.013 90 05/25/2011 0.058 0.046 6.95 0.15 0.016 0.035 0.003 0.002 -0.001 0.003 0.003 0.007 90 08/20/2011 0.116 0.129 7.72 0.61 0.002 0.132 -0.009 0.015 -0.006 0.015 0.010 0.033 90 11/08/2011 0.342 0.200 8.26 0.86 -0.003 0.150 0.002 0.018 -0.003 0.020 0.042 0.039 3-42

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 16 AQUATIC FLORA - FUCUS (pCi/g wet wt.)

COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

(+/-) (+1-) (+1-) (+1-) (+1-) (+/-)

29 03/23/2011 0.003 0.004 0.005 0.009 0.004 0.004 0.002 0.007 0.003 0.004 -0.024 0.029 29 06/07/2011 0.001 0.003 0.002 0.006 0.001 0.003 -0.001 0.005 0.001 0.003 0.000 0.020 29 09/27/2011 0.000 0.002 0.000 0.005 0.000 0.002 0.000 0.004 -0.001 0.003 -0.017 0.015 29 12/14/2011 -0.017 0.017 -0.045 0.031 0.003 0.012 0.015 0.022 0.001 0.011 0.005 0.089 32 03/23/2011 0.007 0.005 0.006 0.010 0.002 0.004 -0.008 0.007 -0.002 0.004 -0.010 0.032 32 05/25/2011 0.001 0.003 0.000 0.005 0.001 0.003 0.002 0.005 0.002 0.003 0.009 0.019 32 08/10/2011 -0.007 0.012 -0.072 0.029 -0.001 0.010 0.009 0.016 0.007 0.008 -0.047 0.071 32 11/07/2011 -0.007 0.024 0.020 0.041 -0.014 0.018 0.004 0.032 0.008 0.016 -0.114 0.150 33 02/14/2011 0.001 0.011 -0.019 0.022 0.001 0.009 -0.001 0.015 0.005 0.008 0.026 0.072 33 05/25/2011 -0.002 0.003 0.006 0.005 0.001 0.003 0.001 0.005 0.000 0.003 -0.008 0.020 33 08/20/2011 0.016 0.020 -0.024 0.042 0.009 0.016 -0.015 0.029 0.001 0.015 -0.020 0.126 33 11/08/2011 0.000 0.018 -0.001 0.038 -0.002 0.013 0.005 0.024 -0.007 0.013 -0.083 0.128 35 03/19/2011 0.001 0.009 0.007 0.017 -0.003 0.007 -0.005 0.013 0.005 0.007 -0.002 0.055 35 05/25/2011 0.001 0.003 0.000 0.005 0.000 0.003 -0.005 0.005 0.000 0.004 0.024 0.019 35 08/20/2011 -0.006 0.014 -0.023 0.026 0.000 0.010 0.009 0.017 -0.002 0.011 0.044 0.079 35 11/08/2011 -0.012 0.021 -0.002 0.043 -0.004 0.016 0.001 0.028 -0.022 0.018 -0.020 0.145 36 03/19/2011 0.001 0.006 0.003 0.014 -0.002 0.005 0.000 0.009 -0.006 0.006 0.015 0.041 36 06/07/2011 0.000 0.002 0.002 0.005 0.001 0.002 -0.002 0.004 -0.001 0.003 -0.002 0.018 36 09/28/2011 0.009 0.014 -0.013 0.024 -0.005 0.011 0.005 0.020 0.009 0.011 -0.056 0.086 36 11/08/2011 -0.006 0.025 --0.039 0.052 0.012 0.019 0.001 0.033 -0.005 0.018 -0.126 0.172 90 02/14/2011 0.002 0.007 -0.022 0.014 0.002 0.005 0.001 0.010 0.001 0.006 0.026 0.044 90 05/25/2011 0.001 0.003 0.002 0.006 0.000 0.003 0.000 0.005 -0.001 0.003 -0.009 0.018 90 08/20/2011 0.002 0.017 0.006 0.036 -0.002 0.014 0.024 0.025 -0.008 0.014 -0.029 0.102 90 11/08/2011 0.034 0.028 0.011 0.047 -0.008 0.019 -0.018 0.033 -0.028 0.020 -0.001 0.170 3-43

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 16 AQUATIC FLORA - FUCUS (pCi/g wet wt.)

COLLECTION LOCATION DATE ..... Ag-1iOM. . Sb-125 -- 1-131. ..... Cs-. 34 .. Cs-i.37 -----I Th-232 decay chain*

(+/-) (+/-) (+/-) (+/-) (+1-) (+1-)

29 03/23/2011 -0.001 0.003 0.003 0.008 0.049 0.020 0.000 0.003 0.002 0.003 0.052 0.027 29 06/07/2011 0.000 0.002 0.002 0.006 0.017 0.031 0.000 0.002 0.002 0.002 0.045 0.034 29 09/27/2011 -0.002 0.002 0.001 0.004 0.043 0.026 0.000 0.002 0.002 0.002 0.076 0.010 29 12/14/2011 -0.001 0.010 -0.008 0.032 0.016 0.019 0.003 0.013 0.001 0.012 0.105 0.071 32 03/23/2011 0.005 0.004 -0.001 0.009 0.072 0.024 0.000 0.004 -0.003 0.004 0.063 0.029 32 05/25/2011 0.003 0.002 -0.002 0.005 0.032 0.032 0.000 0.002 0.001 0.002 0.058 0.035 32 08/10/2011 0.006 0.008 0.005 0.022 0.024 0.015 -0.006 0.009 -0.013 0.010 0.058 0.057 32 11/07/2011 0.005 0.017 0.003 0.038 -0.013 0.027 -0.005 0.016 0.007 0.017 0.042 0.036 33 02/14/2011 0.005 0.008 -0.005 0.020 0.017 0.017 0.002 0.008 -0.004 0.009 0.076 0.060 33 05/25/2011 0.000 0.002 0.001 0.005 0.003 0.031 0.001 0.002 0.003 0.002 0.034 0.025 33 08/20/2011 0.002 0.015 0.006 0.030 0.023 0.028 -0.005 0.016 -0.008 0.016 0.110 0.082 33 11/08/2011 -0.004 0.013 0.007 0.036 -0.036 0.025 -0.013 0.016 0.001 0.014 0.110 0.068 35 03/19/2011 0.001 0.006 0.003 0.015 0.000 0.033 0.009 0.006 0.012 0.006 0.083 0.027 35 05/25/2011 -0.002 0.002 0.005 0.006 0.006 0.035 0.001 0.002 -0.001 0.002 0.029 0.016 35 08/20/2011 -0.003 0.010 0.005 0.024 0.008 0.022 -0.021 0.011 -0.001 0.011 0.024 0.063 35 11/08/2011 -0.011 0.015 -0.007 0.047 0.015 0.027 -0.001 0.018 0.008 0.018 0.078 0.112 36 03/19/2011 -0.004 0.005 0.001 0.012 0.042 0.028 -0.003 0.005 0.003 0.005 0.043 0.037 36 06/07/2011 0.001 0.002 -0.003 0.005 0.017 0.030 0.000 0.002 0.002 0.002 0.031 0.026 36 09/28/2011 -0.004 0.010 -0.010 0.025 0.015 0.033 -0.009 0.011 0.002 0.010 0.005 0.021 36 11/08/2011 -0.008 0.017 -0.014 0.040 0.013 0.028 -0.018 0.018 -0.006 0.018 0.045 0.071 90 02/14/2011 -0.004 0.005 0.006 0.014 0.020 0.014 -0.010 0.005 0.001 0.005 0.053 0.030 90 05/25/2011 -0.002 0.002 0.001 0.005 0.038 0.033 -0.002 0.002 0.002 0.002 0.048 0.026 90 08/20/2011 -0.005 0.012 0.021 0.035 0.041 0.032 -0.010 0.012 0.005 0.013 0.038 0.060 90 11/08/2011 0.001 0.020 0.008 0.045 -0.010 0.031 -0.031 0.018 -0.006 0.022 0.079 0.096

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-44

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 17A FISH - FLOUNDER (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

(+/-) (+/-) (+1-) (+--)

(+0-) (+1-)

32 05/10/2011 0.024 0.040 4.46 0.33 0.026 0.054 0.001 0.004 0.002 0.004 0.009 0.010 0.000 0.005 -0.005 0.005 0.003 0.015 32 10/11/2011 0.000 0.053 4.84 0.41 -0.008 0.068 35 05/10/2011 -0.001 0.054 4.20 0.34 0.018 0.071 0.003 0.005 0.000 0.006 0.008 0.016 35 10/11/2011 -0.013 0.073 3.72 0.22 0.023 0.094 0.003 0.007 0.000 0.007 -0.002 0.017 COLLECTION LOCATION DATE Co-60 Zn-65(+/-) Nb-95(+/-) Zr-95(+/-) Ru-103 Ru-106

(+/-) (+/-)

(+/-)

32 05/10/2011 -0.002 0.004 -0.004 0.009 0.001 0.005 0.001 0.008 0.003 0.006 0.012 0.031 32 10/11/2011 -0.002 0.005 0.000 0.012 -0.001 0.006 -0.001 0.011 0.000 0.007 0.012 0.044

-0.005 0.006 -0.005 0.011 -0.001 0.007 0.013 0.040 35 05/10/2011 0.002 0.006 -0.002 0.009 35 10/11/2011 0.000 0.007 -0.030 0.016 -0.020 0.015 -0.003 0.013 0.002 0.009 -0.012 0.062 COLLECTION LOCATION DATE Ag-110M Sb-1i25 1-131 Cs-134 Cs- 137 Th-232 decay chain*

(+/-) (+1-) (+/-) (+/-)

(+3-) (+--)

32 05/10/2011 0.000 0.003 0.006 0.010 -0.004 0.038 -0.001 0.004 0.000 0.004 0.011 0.057 32 10/11/2011 0.000 0.005 -0.003 0.013 -0.006 0.049 0.000 0.005 0.000 0.006 0.039 0.032 35 05/10/2011 0.002 0.005 0.000 0.012 -0.048 0.049 -0.002 0.005 0.005 0.005 -0.044 0.013 35 10/11/2011 -0.010 0.006 0.006 0.018 0.031 0.052 -0.002 0.008 0.006 0.007 0.005 0.014 The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-45

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 17B FISH - OTHER (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

(+/-) (+/-) (+/-) (+/-) (+1-) (+1-)

32 05/10/2011 0.008 0.050 3.94 0.39 -0.003 0.063 0.002 0.005 0.002 0.005 -0.010 0.013 32 07/21/2011 0.083 0.162 3.32 0.47 0.141 0.189 -0.001 0.015 0.006 0.018 -0.012 0.034 32 10/20/2011 -0.096 0.124 3.39 0.47 -0.131 0.137 0.014 0.015 0.004 0.016 0.032 0.035 35 06/21/2011 0.047 0.157 4.56 0.60 0.054 0.180 0.012 0.019 0.011 0.021 0.023 0.042 35 09/12/2011 0.029 0.157 4.01 0.56 0.021 0.188 -0.003 0.016 -0.009 0.019 0.019 0.040 35 10/11/2011 -0.025 0.060 3.75 0.19 0.005 0.082 -0.007 0.006 0.000 0.007 -0.006 0.016 COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-1 06 32 05/10/2011 0.001 0.005 0.000 0.011 0.006 0.006 0.007 0.011 -0.002 0.007 0.011 0.043 32 07/21/2011 0.012 0.017 0.026 0.039 -0.008 0.016 0.008 0.030 0.009 0.021 0.011 0.151 32 10/20/2011 -0.004 0.016 0.026 0.041 0.020 0.016 0.025 0.028 -0.001 0.015 0.005 0.125 35 06/21/2011 -0.007 0.022 -0.079 0.047 0.020 0.021 0.020 0.034 -0.015 0.022 -0.032 0.171 35 09/12/2011 0.014 0.019 0.020 0.034 -0.012 0.021 -0.014 0.036 0.011 0.019 -0.074 0.165 35 10/11/2011 0.002 0.006 0.001 0.015 -0.006 0.013 0.002 0.012 -0.004 0.008 0.022 0.052 COLLECTION LOCATION DATE Ag-i M.. Sb-125 1-131 Cs-i 34 Cs-i 37 Th-232 decay chain*

32 05/10/2011 0.001 0.004 0.001 0.013 -0.017 0.045 0.000 0.005 -0.008 0.009 0.034 0.024 32 07/21/2011 -0.017 0.017 -0.015 0.047 0.019 0.054 -0.005 0.017 0.007 0.018 0.024 0.081 32 10/20/2011 -0.006 0.014 0.009 0.036 -0.029 0.045 -0.001 0.015 0.007 0.015 -0.023 0.025 35 06/21/2011 0.004 0.019 0.037 0.051 -0.003 0.041 0.010 0.023 0.001 0.022 0.101 0.060 35 09/12/2011 0.010 0.017 -0.062 0.049 0.026 0.051 -0.004 0.016 0.000 0.019 0.032 0.050 35 10/11/2011 -0.005 0.005 -0.001 0.015 0.006 0.056 -0.003 0.007 0.003 0.006 0.016 0.011 The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-46

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 18 MUSSELS (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7(+--) K-40(+--) Cr-51(+--) Mn-54(+--) Co-58(+--) Fe-59 (+--)

30 03/30/2011 0.027 0.095 2.33 0.25 -0.077 0.116 0.002 0.009 -0.002 0.009 -0.014 0.021 30 05/10/2011 0.000 0.054 2.45 0.27 -0.064 0.083 -0.003 0.005 -0.002 0.005 -0.006 0.012 30 11/30/2011 0.082 0.235 0.63 0.65 0.187 0.199 0.018 0.019 0.003 0.017 -0.013 0.041 31 09/13/2011 0.107 0.303 0.20 0.63 0.004 0.301 0.006 0.035 0.020 0.032 -0.024 0.063 COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

(+/-) (+/-) (+/-) (+/-) (+/-) (+7-)

30 03/30/2011 0.000 0.009 -0.016 0.019 0.010 0.010 0.008 0.017 0.006 0.012 -0.019 0.081 30 05/10/2011 -0.004 0.004 0.013 0.010 -0.002 0.006 -0.003 0.010 -0.002 0.006 -0.016 0.042 30 11/30/2011 0.004 0.025 0.002 0.038 0.005 0.020 0.026 0.047 -0.021 0.024 0.035 0.204 31 09/13/2011 0.024 0.028 0.005 0.067 0.012 0.031 -0.012 0.051 0.014 0.040 0.014 0.240 COLLECTION

-LOCATION - .....-DATE ..... ....- Ag-Ib0M ------ Sb-125 ------......--1-131 ....... ......-Cs-134 ------ Cs-1.37 . Th-232 decay chain*

30 03/30/2011 -0.002 0.009 0.000 0.024 -0.020 0.053 -0.042 0.010 -0.005 0.009 0.056 0.055 30 05/10/2011 -0.002 0.004 0.000 0.012 -0.006 0.047 0.000 0.005 0.001 0.005 -0.020 0.012 30 11/30/2011 -0.017 0.019 0.038 0.057 0.002 0.038 0.001 0.019 -0.001 0.023 0.042 0.107 31 09/13/2011 0.013 0.022 0.035 0.108 -0.057 0.066 0.003 0.033 0.006 0.033 0.005 0.069

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-47

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 19 OYSTERS (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 31 02/23/2011 -0.007 0.168 1.98 0.42 -0.114 0.181 0.005 0.016 0.001 0.018 0.013 0.038 31 06/15/2011 0.083 0.168 2.23 0.49 -0.090 0.164 -0.010 0.017 0.011 0.017 -0.022 0.034 31 08/24/2011 0.052 0.251 2.01 0.73 -0.145 0.243 0.009 0.029 -0.004 0.024 0.012 0.047 31 12/28/2011 0.049 0.174 1.84 0.42 0.004 0.018 0.000 0.019 0.002 0.040 32 02/16/2011 -0.026 0.145 2.21 0.44 -0.103 0.152 -0.006 0.016 0.002 0.018 0.011 0.036 32 06/15/2011 0.029 0.170 1.31 0.43 -0.035 0.186 0.005 0.016 0.000 0.016 -0.012 0.036 32 07/07/2011 0.205 0.211 1.95 0.56 0.108 0.221 0.011 0.021 0.006 0.021 -0.011 0.041 32 11/15/2011 0.008 0.066 1.14 0.27 -0.072 0.074 0.002 0.006 0.003 0.007 -0.004 0.015 32 12/28/2011 -0.089 0.163 2.23 0.40 0.006 0.017 0.008 0.018 -0.003 0.039 34 02114/2011 -0.014 0.158 1.84 0.44 0.195 0.188 0.012 0.017 -0.009 0.017 -0.005 0.040 34 06/15/2011 -0.154 0.141 2.05 0.44 -0.003 0.173 0.003 0.017 -0.001 0.016 -0.018 0.037 34 09/20/2011 -0.023 0.113 1.43 0.34 -0.104 0.123 -0.011 0.013 -0.017 0.014 -0.023 0.027 34 11/21/2011 0.012 0.096 1.82 0.45 0.012 0.128 -0.004 0.010 -0.002 0.011 -0.007 0.022 36 02/16/2011 -0.029 0.171 1.54 0.46 0.028 0.192 -0.010 0.019 -0.012 0.019 -0.001 0.041 37 02/16/2011 0.106 0.168 1.58 0.48 -0.030 0.188 -0.003 0.021 -0.006 0.019 0.000 0.044 37 06/07/2011 0.023 0.061 1.52 0.24 -0.068 0.084 0.003 0.005 0.000 0.005 0.010 0.013 37 09/30/2011 -0.137 0.181 1.56 0.49 -0.193 0.194 0.004 0.020 -0.014 0.021 -0.012 0.041 37 11/22/2011 0.062 0.154 1.29 0.40 0.072 0.194 -0.008 0.016 -0.012 0.017 -0.019 0.038 68 02/16/2011 0.156 0.187 1.30 0.52 0.032 0.199 0.006 0.022 0.007 0.023 0.023 0.045 68 06/28/2011 0.047 0.078 2.07 0.30 0.007 0.092 0.006 0.009 0.002 0.009 0.000 0.018 68 08/24/2011 -0.016 0.222 2.70 0.78 -0.045 0.274 -0.013 0.025 -0.021 0.025 0.046 0.053 68 11/30/2011 0.075 0.094 2.12 0.54 0.103 0.101 0.008 0.011 0.007 0.010 -0.008 0.020 88 06/15/2011 -0.019 0.158 1.76 0.44 -0.025 0.181 -0.005 0.017 -0.011 0.018 -0.022 0.036 88 09/19/2011 -0.078 0.128 1.26 0.29 0.079 0.141 0.000 0.013 -0.008 0.014 0.001 0.028 88 11/15/2011 0.050 0.061 1.63 0.20 0.003 0.070 0.000 0.007 -0.007 0.007 -0.018 0.016 3-48

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 19 OYSTERS (pCi/g wet wt.)

COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 31 02/23/2011 0.020 0.019 -0.013 0.046 0.006 0.021 0.009 0.034 0.006 0.023 0.070 0.154 31 06/15/2011 0.005 0.017 -0.044 0.045 0.007 0.019 0.021 0.030 0.021 0.019 -0.026 0.143 31 08/24/2011 -0.005 0.027 -0.083 0.067 -0.014 0.032 -0.018 0.054 -0.002 0.029 0.011 0.279 31 12/28/2011 -0.005 0.019 0.007 0.044 0.010 0.020 -0.006 0.037 0.014 0.020 -0.110 0.175 32 02/16/2011 0.013 0.020 -0.047 0.045 0.027 0.020 -0.010 0.032 0.008 0.019 0.006 0.159 32 06/15/2011 -0.007 0.017 -0.090 0.042 0.012 0.020 -0.010 0.032 0.005 0.021 0.021 0.158 32 07/07/2011 0.004 0.020 -0.010 0.041 0.029 0.025 0.018 0.043 0.002 0.026 0.059 0.187 32 11/15/2011 0.002 0.007 0.006 0.013 0.007 0.008 0.005 0.013 -0.001 0.008 0.017 0.061 32 12/28/2011 0.009 0.019 -0.073 0.041 0.024 0.019 0.030 0.033 -0.002 0.021 -0.076 0.157 34 02/14/2011 -0.001 0.019 -0.022 0.045 0.015 0.020 -0.001 0.031 0.000 0.019 -0.081 0.149 34 06/15/2011 -0.004 0.018 -0.012 0.042 0.000 0.017 0.007 0.031 -0.003 0.019 0.087 0.133 34 09/20/2011 -0.008 0.014 0.012 0.032 0.034 0.016 0.002 0.023 0.008 0.014 0.033 0.108 34 11/21/2011 -0.003 0.013 0.009 0.019 0.012 0.012 0.005 0.022 -0.003 0.013 0.010 0.095 36 02/16/2011 -0.008 0.021 -0.019 0.041 0.036 0.021 -0.001 0.036 -0.001 0.023 0.012 0.170 37 02/16/2011 0.004 0.022 -0.082 0.048 -0.004 0.021 0.010 0.033 -0.006 0.022 0.057 0.171 37 06/07/2011 0.002 0.005 -0.003 0.010 -0.001 0.006 -0.003 0.010 0.003 0.008 -0.020 0.041 37 09/30/2011 0.008 0.022 -0.001 0.050 0.009 0.022 0.025 0.038 0.004 0.024 -0.093 0.187 37 11/22/2011 0.011 0.017 -0.062 0.038 -0.001 0.018 0.023 0.029 0.002 0.023 -0.022 0.153 68 02/16/2011 -0.001 0.020 -0.043 0.057 0.014 0.023 0.016 0.038 -0.004 0.023 -0.015 0.191 68 06/28/2011 0.009 0.009 -0.002 0.015 0.000 0.009 -0.009 0.017 -0.007 0.010 0.018 0.071 68 08/24/2011 -0.005 0.028 -0.023 0.064 -0.021 0.029 0.021 0.046 0.005 0.031 -0.014 0.263 68 11/30/2011 0.000 0.013 0.018 0.026 0.004 0.012 -0.017 0.020 0.000 0.014 -0.045 0.089 88 06/15/2011 0.008 0.015 0.022 0.043 0.017 0.020 0.002 0.035 0.001 0.021 0.030 0.154 88 09/19/2011 0.003 0.014 0.004 0.032 0.009 0.018 -0.030 0.025 -0.004 0.015 -0.002 0.129 88 11/15/2011 0.002 0.007 0.000 0.015 0.004 0.008 0.005 0.013 -0.002 0.008 -0.006 0.057 3-49

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 19 OYSTERS (pCi/g wet wt.)

COLLECTION LOCATION DATE Ag-IVM Sb-125 1-131 Cs-134 Cs-137 Th-232 decay chain*

(+/-) (+1-) (+1-) (+1-) (+1-) (+1-)

31 02/23/2011 -0.007 0.015 -0.033 0.047 0.031 0.056 -0.017 0.020 0.005 0.017 0.019 0.044 31 06/15/2011 -0.014 0.017 -0.009 0.044 0.030 0.054 0.001 0.019 0.020 0.017 0.004 0.030 31 08/24/2011 0.018 0.025 0.033 0.075 -0.011 0.046 -0.013 0.030 -0.038 0.028 0.012 0.049 31 12/28/2011 -0.005 0.016 0.014 0.050 0.006 0.020 0.006 0.019 -0.027 0.033 32 02/16/2011 0.056 0.017 0.022 0.045 0.013 0.045 -0.009 0.018 0.013 0.018 0.012 0.041 32 06/15/2011 0.070 0.029 -0.051 0.046 -0.013 0.059 0.015 0.020 -0.021 0.021 0.006 0.034 32 07/07/2011 0.092 0.037 0.045 0.062 0.024 0.058 -0.004 0.024 0.009 0.029 0.066 0.081 32 11/15/2011 0.112 0.016 0.012 0.018 0.007 0.026 0.000 0.007 0.004 0.007 0.027 0.024 32 12/28/2011 0.001 0.017 0.024 0.052 -0.025 0.021 -0.016 0.019 0.135 0.062 34 02/14/2011 0.005 0.017 0.014 0.050 -0.012 0.061 0.008 0.020 -0.003 0.017 0.005 0.032 34 06/15/2011 -0.003 0.015 0.007 0.040 -0.025 0.055 -0.011 0.019 0.003 0.016 0.018 0.060 34 09/20/2011 0.009 0.012 0.016 0.037 0.010 0.028 -0.012 0.015 -0.011 0.014 0.071 0.026 34 11/21/2011 0.002 0.008 0.008 0.031 -0.009 0.045 -0.004 0.009 0.001 0.010 -0.007 0.021 36 02/16/2011 -0.009 0.018 0.001 0.051 0.006 0.054 -0.001 0.022 0.005 0.021 0.090 0.042 37 02/16/2011 -0.009 0.017 0.019 0.048 -0.035 0.055 0.011 0.019 0.021 0.020 0.035 0.044 37 06/07/2011 0.001 0.004 -0.006 0.014 -0.035 0.069 0.006 0.005 0.003 0.005 0.021 0.021 37 09/30/2011 -0.009 0.019 -0.043 0.053 0.024 0.057 0.008 0.024 0.008 0.022 0.012 0.052 37 11/22/2011 0.005 0.016 -0.009 0.046 0.005 0.057 -0.062 0.020 -0.012 0.018 -0.004 0.068 68 02/16/2011 -0.007 0.019 -0.008 0.058 -0.041 0.058 0.009 0.025 0.004 0.021 0.015 0.040 68 06/28/2011 0.002 0.008 0.013 0.020 0.012 0.043 -0.004 0.008 0.004 0.008 -0.013 0.049 68 08/24/2011 0.000 0.025 0.049 0.072 0.008 0.048 0.000 0.030 -0.005 0.026 -0.016 0.052 68 11/30/2011 -0.002 0.009 -0.006 0.028 -0.006 0.023 -0.003 0.010 0.009 0.012 0.002 0.027 88 06/15/2011 -0.006 0.016 -0.005 0.045 0.023 0.058 0.010 0.019 -0.017 0.019 0.060 0.039 88 09/19/2011 0.003 0.013 0.008 0.039 0.010 0.031 0.008 0.016 -0.012 0.015 0.030 0.026 88 11/15/2011 0.001 0.006 0.002 0.018 -0.001 0.024 0.003 0.007 0.001 0.007 0.017 0.014 The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-50

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 20 CLAMS (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Co-58

(+1-) -0.003--Mn-54 0 )0

-- -0.002---Fe-590.

29 03/23/2011 0.044 0.046 2.030 0.156 0.026 0.053 -0.003 0.005 0.001 0.005 -0.002 0.011 29 06/08/2011 0.013 0.048 2.120 0.235 0.048 0.063 0.002 0.004 0.001 0.005 0.000 0.011 29 09/12/2011 -0.066 0.163 1.370 0.527 0.012 0.199 0.012 0.017 -0.002 0.016 -0.016 0.029 29 11/08/2011 0.002 0.205 2.760 0.677 -0.009 0.230 -0.011 0.025 0.005 0.021 0.001 0.053 35 03/23/2011 0.004 0.066 1.850 0.226 0.004 0.080 -0.009 0.007 -0.006 0.008 -0.009 0.016 35 06/16/2011 -0.107 0.139 1.920 0.483 -0.060 0.180 -0.012 0.016 -0.006 0.017 -0.007 0.036 35 09/12/2011 0.160 0.174 1.490 0.421 0.017 0.199 0.016 0.021 -0.005 0.021 -0.027 0.045 35 11/04/2011 -0.022 0.157 1.380 0.422 -0.033 0.185 0.025 0.019 -0.010 0.019 -0.005 0.042 38 03/23/2011 0.018 0.064 1.780 0.199 0.029 0.077 -0.003 0.007 0.003 0.007 -0.023 0.016 38 06/16/2011 -0.022 0.134 1.960 0.398 0.159 0.163 -0.004 0.013 -0.007 0.014 0.020 0.032 38 09/12/2011 0.012 0.224 2.760 0.651 0.035 0.233 0.009 0.024 -0.003 0.026 0.040 0.049 38 11/04/2011 0.154 0.185 1.850 0.633 0.133 0.230 0.005 0.021 0.019 0.025 0.051 0.045 39 03/23/2011 0.037 0.062 2.080 0.189 -0.029 0.072 -0.002 0.006 0.002 0.006 0.000 0.014 39 06/16/2011 0.100 0.151 1.970 0.411 0.027 0.162 0.013 0.015 -0.009 0.015 0.014 0.035 39 09/28/2011 0.093 0.148 2.010 0.392 -0.013 0.188 0.009 0.016 -0.008 0.018 -0.008 0.038 39 12/02/2011 0.003 0.082 2.440 0.247 -0.047 0.113 0.006 0.008 0.001 0.009 0.012 0.019 3-51

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 20 CLAMS (pCi/g wet wt.)

COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-1 06

(+/-) (+/-) (+/-) (+/-) (+/-) (+/-)

29 03/23/2011 -0.001 0.005 -0.013 0.011 0.004 0.006 -0.002 0.010 0.002 0.006 -0.007 0.045 29 06/08/2011 0.002 0.004 0.004 0.010 0.004 0.006 -0.002 0.010 -0.008 0.006 -0.003 0.039 29 09/12/2011 0.016 0.018 0.008 0.034 0.000 0.020 -0.027 0.036 -0.008 0.020 -0.012 0.162 29 11/08/2011 0.018 0.028 -0.032 0.055 0.004 0.024 0.025 0.045 -0.003 0.028 0.207 0.249 35 03/23/2011 0.006 0.008 0.016 0.018 0.006 0.008 0.003 0.014 0.002 0.008 0.004 0.065 35 06/16/2011 0.017 0.017 -0.012 0.036 0.021 0.017 0.009 0.030 -0.011 0.019 0.039 0.150 35 09/12/2011 0.011 0.022 0.008 0.045 -0.013 0.022 0.020 0.039 -0.015 0.022 -0.185 0.180 35 11/04/2011 0.017 0.018 -0.013 0.043 0.009 0.019 -0.021 0.034 -0.006 0.019 -0.054 0.164 38 03/23/2011 -0.001 0.007 0.000 0.017 0.002 0.008 0.003 0.013 0.000 0.008 -0.045 0.060 38 06/16/2011 0.000 0.015 -0.061 0.032 -0.007 0.016 -0.031 0.027 -0.001 0.017 -0.125 0.135 38 09/12/2011 0.019 0.031 -0.015 0.055 -0.021 0.030 0.021 0.045 -0.001 0.027 0.023 0.261 38 11/04/2011 0.003 0.023 -0.040 0.049 0.013 0.024 -0.003 0.040 0.008 0.025 0.113 0.210 39 03/23/2011 0.004 0.007 -0.006 0.014 -0.001 0.007 0.007 0.012 0.003 0.008 0.025 0.055 39 06/16/2011 0.003 0.017 -0.019 0.038 0.002 0.018 0.001 0.029 -0.011 0.018 0.087 0.140 39 09/28/2011 0.003 0.016 -0.035 0.037 0.014 0.018 -0.001 0.031 -0.004 0.021 0.043 0.149 39 12/02/2011 0.006 0.010 -0.029 0.020 0.003 0.010 -0.002 0.017 -0.012 0.011 0.034 0.075 3-52

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 20 CLAMS (pCi/g wet wt.)

COLLECTION LOCATION DATE Ag-110M Sb-125 1-131 Cs-134 Cs-137 Th-232 decay chain*

(+/-) (+/-) (+/-) (+/-) (+1-) (+/-)

29 03/23/2011 -0.003 0.005 0.019 0.013 0.000 0.019 -0.006 0.006 -0.004 0.005 0.029 0.019 29 06/08/2011 0.001 0.004 0.004 0.010 0.026 0.053 -0.001 0.004 -0.002 0.005 0.014 0.016 29 09/12/2011 0.001 0.016 -0.016 0.049 -0.052 0.055 0.001 0.017 -0.014 0.019 0.018 0.077 29 11/08/2011 -0.011 0.021 0.006 0.060 0.013 0.038 -0.003 0.024 0.001 0.025 0.080 0.096 35 03/23/2011 -0.001 0.007 -0.009 0.018 -0.020 0.028 -0.002 0.008 0.005 0.007 0.022 0.018 35 06/16/2011 0.004 0.015 -0.001 0.046 -0.019 0.055 -0.009 0.020 -0.008 0.016 0.052 0.078 35 09/12/2011 -0.021 0.020 0.047 0.048 -0.031 0.056 0.013 0.019 0.018 0.021 0.016 0.080 35 11/04/2011 -0.008 0.018 0.027 0.048 -0.007 0.045 -0.022 0.020 0.010 0.020 0.020 0.043 38 03/23/2011 -0.007 0.006 0.009 0.018 0.000 0.026 -0.001 0.008 0.007 0.007 0.037 0.034 38 06/16/2011 -0.008 0.013 -0.033 0.038 0.042 0.050 0.009 0.015 0.004 0.015 -0.012 0.028 38 09/12/2011 0.010 0.022 -0.006 0.058 0.015 0.051 -0.025 0.031 -0.004 0.024 -0.008 0.111 38 11/04/2011 -0.003 0.021 0.023 0.057 -0.018 0.058 -0.005 0.026 0.006 0.023 0.015 0.087 39 03/23/2011 -0.007 0.006 -0.001 0.017 0.002 0.025 -0.001 0.007 -0.001 0.006 0.016 0.016 39 06/16/2011 0.001 0.015 0.018 0.040 0.020 0.054 -0.007 0.018 0.007 0.016 0.026 0.036 39 09/28/2011 -0.010 0.016 -0.004 0.043 -0.006 0.058 -0.046 0.020 -0.004 0.017 -0.003 0.032 39 12/02/2011 0.003 0.008 0.000 0.024 -0.003 0.042 -0.014 0.010 -0.001 0.009 0.040 0.063

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-53

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 21 SCALLOPS Scallops were not sampled in 2011. See discussion in Section 4.21.

3-54

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 22 LOBSTERS (pCi/g wet wt.)

COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

(+1-) (+/-) (+/-) (+/-) (+/-) (+/-)

32 03/18/2011 -0.051 0.067 1.97 0.22 -0.044 0.083 0.002 0.006 0.000 0.008 0.001 0.017 32 05/04/2011 -0.021 0.059 2.63 0.28 -0.009 0.071 0.001 0.006 0.003 0.007 -0.008 0.015 32 08/08/2011 0.009 0.078 2.82 0.26 0.022 0.099 0.009 0.009 0.002 0.010 -0.001 0.021 32 11/08/2011 0.255 0.280 2.78 0.94 -0.060 0.368 -0.011 0.041 0.010 0.043 0.055 0.082 35 03/30/2011 0.043 0.086 2.64 0.38 0.052 0.099 0.003 0.009 0.001 0.009 0.018 0.021 35 05/04/2011 -0.021 0.041 2.41 0.24 0.025 0.063 0.002 0.004 0.003 0.004 -0.006 0.010 35 08/08/2011 0.054 0.103 1.36 0.37 -0.132 0.135 0.002 0.010 -0.001 0.010 0.014 0.024 35 11/08/2011 0.033 0.264 2.37 0.92 -0.024 0.295 0.013 0.030 0.009 0.035 0.103 0.070 37 02/23/2011 0.079 0.156 1.82 0.52 -0.260 0.155 0.002 0.017 0.000 0.017 0.011 0.035 37 06/27/2011 0.072 0.087 2.87 0.40 0.015 0.121 0.011 0.011 -0.004 0.012 0.001 0.026 37 11/22/2011 0.008 0.077 3.02 0.27 0.042 0.097 -0.002 0.008 0.002 0.009 -0.004 0.021 COLLECTION LOCATION DATE 303121 0.1Co-6000 -015Zn-65 .7 00-1Nb-950 -0.5-) Zr-95 Ru-1 03 0.009-)-/ 00 Ru-10601--

32 03/18/2011 0.001 0.007 -0.015 0.017 0.001 0.008 -0.001 0.014 -0.005 0.009 0.000 0.061 32 05/04/2011 0.000 0.006 -0.004 0.013 0.003 0.007 0.000 0.012 -0.008 0.008 0.009 0.052 32 08/08/2011 -0.001 0.009 0.021 0.021 0.004 0.010 -0.003 0.017 0.002 0.010 0.027 0.080 32 11/08/2011 0.016 0.034 -0.051 0.079 0.004 0.037 0.025 0.060 0.000 0.038 -0.282 0.358 35 03/30/2011 0.000 0.010 -0.001 0.018 0.003 0.010 -0.004 0.018 0.005 0.011 -0.014 0.076 35 05/04/2011 0.001 0.004 -0.003 0.010 -0.003 0.005 0.002 0.008 0.000 0.006 0.011 0.035 35 08/08/2011 -0.013 0.011 -0.019 0.022 0.001 0.013 -0.009 0.022 -0.002 0.013 0.026 0.100 35 11/08/2011 -0.034 0.032 -0.046 0.081 -0.008 0.032 -0.044 0.049 -0.013 0.038 -0.234 0.291 37 02/23/2011 -0.004 0.020 -0.010 0.036 0.016 0.022 0.028 0.031 -0.005 0.017 0.035 0.148 37 06/27/2011 0.001 0.012 0.014 0.019 0.000 0.013 0.012 0.018 0.001 0.012 -0.012 0.089 37 11/2212011 -0.009 0.011 0.003 0.019 -0.005 0.009 0.011 0.016 -0.002 0.010 -0.020 0.067 3-55

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 22 LOBSTERS (pCi/g wet wt.)

COLLECTION LO.CATION -----DATE _A_-_Ag-ilOM Sb-i25 ------ 1-131 ............. Cs-i_34 ----- Cs-i 37 Th-232 decay chain*

(+/-) (+/-) (+/-) (+/-) (+/-) (+1-)

32 03/1812011 -0.008 0.007 0.002 0.017 0.013 0.040 -0.003 0.008 -0.002 0.007 0.025 0.016 32 05/04/2011 0.000 0.005 -0.001 0.015 0.022 0.041 0.003 0.006 0.003 0.006 0.044 0.022 32 08/08/2011 0.001 0.008 -0.001 0.023 0.009 0.028 0.005 0.009 0.004 0.009 0.037 0.085 32 11/0812011 -0.008 0.036 -0.025 0.101 -0.026 0.062 -0.073 0.039 -0.005 0.043 0.012 0.060 35 03/30/2011 0.004 0.008 -0.004 0.022 -0.002 0.046 0.000 0.009 0.004 0.008 0.005 0.028 35 05/04/2011 -0.002 0.004 0.005 0.011 -0.003 0.030 -0.003 0.004 0.003 0.004 0.019 0.017 35 08/08/2011 0.002 0.011 0.006 0.032 0.015 0.039 -0.001 0.011 0.001 0.012 0.021 0.106 35 11/08/2011 -0.034 0.032 -0.016 0.082 -0.045 0.061 0.008 0.036 0.031 0.033 -0.017 0.058 37 02/23/2011 0.010 0.015 -0.035 0.043 0.025 0.049 -0.013 0.019 -0.023 0.018 0.003 0.034 37 06/27/2011 0.004 0.010 -0.001 0.023 -0.002 0.056 0.005 0.009 0.011 0.010 -0.034 0.026 37 11/22/2011 -0.002 0.007 0.002 0.020 0.017 0.051 -0.049 0.008 -0.003 0.008 -0.003 0.039

• The highest result for Th-232 and it's two daughters, Th-228 and Act-228, is reported.

3-56

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station NOTES FOR DATA TABLES the A Third quarter TLD for Location #7 was lost during a storm. It was replaced for fourth quarter.

Fourth quarter TLD for Location #12 was lost when the utility pole on which it was mounted was replaced.

Collection Dates for Air Particulates and Iodine are listed as Monday through Sunday, however the typical change-out days are on Tuesdays.

Air Particulates and lodines had loss of power at Location #4 during September D due to a storm. Temporary power was used starting in October and permanent power was restored later in the year.

The REMODCM requires quarterly analyses for Sr-89 and Sr-90 on goat milk from two separate locations. Normally the sample for these analyses are composited from monthly or semi-monthly samples taken each quarter. Because E of unavailability, only three milk samples were collected from Location #21 and only two milk samples were collected from Location #24 during year. Except for the second quarter at Location #24, the samples were consumed during gamma analyses and there was insufficient volume left to perform the quarterly Sr-89 and I Sr-90 analyses.

3-57

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station

4. DISCUSSION OF RESULTS This section summarizes the results of the analyses on the REMP samples. DNC has carefully examined the data throughout the year and has presented in this section all cases where station related radioactivity could be detected. The results are compared with previous environmental surveillance data.

Few impacts of the station operation on the environment were observed. Sub-sections contain a description of each particular media or potential exposure pathway. Naturally occurring nuclides such as Be-7, K-40, and Th-232 (and it's daughters Th-228 and Ac-228) were detected in numerous samples.- Be-7, which is produced by cosmic processes, was observed predominantly in airborne and vegetation samples. Th-232 and daughter results were variable and are generally at levels higher than plant related radionuclides.

Cs-1 37 and Sr-90 were observed at levels similar to those of past years. The levels of Cs-1 37 and Sr-90 detected were the result of atmospheric nuclear weapons testing in the 1960's.

Some REMP samples during 2011 identified detectable concentrations of isotopes that could be credibly attributed to the trans-Pacific transport of airborne releases from Fukushima, Japan following the March 11, 2011 Tohoku earthquake.

4.1 Gamma Exposure Rate (Table 1)

Gamma exposure rate is determined from the integrated exposure measured over a calendar quarter using TLDs. Prior to 1990, Victoreen CaF 2(Mn) glass bulb dosimeters were used for these measurements. In 1990, these were replaced by Harshaw CaF 2 (Mn) chips. In 2000, the CaF 2 (Mn) TLDs, were replaced with the CaSO4 (Tm) Panasonic model UD-804 ASx TLDs.

The dosimeters are strategically placed at a number of on-site locations, as well as at inner and outer off-site locations. Starting in 2001, the collection of TLDs was changed from monthly to quarterly and additional measurement locations were incorporated into the REMP requirements listed in the REMODCM (Reference 8). Three more locations were added in mid-2003 to prepare for monitoring the potential effect from the ISFSI. Two Dry Cask Containers were loaded in the first quarter 2005. Three containers were loaded in mid 2006, three in October 2007, three in April 2009, and three in October 2010. None were loaded in 2008 or in 2011. The exposure rate measurements at the three additional TLD locations remain basically unchanged from the background measurements performed prior to any cask loading (six quarter background average mid 2003 - 2004: 9.1 uR/hour at location 73X, 7.4 uR/hour at location 74X and 6.7 uR/hour at location 75X). The unit uR stands for 'micro (u)-

roentgen' with a 'micro' being one-millionth of a roentgen. A roentgen is the quantity of radiation equal to 87.6 ergs of energy per gram of air.

4-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station Table 1 lists the exposure rate measurements for all 44 monitored locations. Trends similar to those of past years are apparent. These measurements demonstrate the general variations in background radiation between the various on-site and off-site locations and include gamma exposure from all sources of radioactivity. For example, the Weather Shack (location 02), MPS3 Discharge (location 05), Environmental Laboratory (location 08), Bay Point Beach (location 09), Pleasure Beach (location 10), Corey Road (location 48), and Site Switchyard Fence (location 73) experience higher exposure rates due to their proximity to granite beds and stonewalls. In addition, the Mystic (location 13C) and Ledyard (location 14C) control locations experience relatively higher background exposure rate than the other control locations at Fisher's Island, Norwich and Old Lyme (locations 12C, 15C and 16C).

The only appreciable effect seen in the recent TLD data is that attributable to the variation in the background radiation that is consistent with previous years. Figure 4.1-1 shows a historical trend of TLD exposure rate measurements, comparing an annual average of all indicator TLDs, an annual average of all control TLDs, and the annual average of the two most critical indicator locations which are used to represent the two closest site boundary residences in the North-northwest and Northeast directions. Examination of the average measurements since 1990, shows interesting site changes and site characteristics. For example, the average of all indicator locations for the period when MPS1 was still in operation (through 1995) exhibit the effects of N-16 BWR turbine building sky-shine to immediate areas onsite. As discussed in previous annual reports, the effects of sky-shine at onsite monitoring stations were increased exposure rates as high as 6 uR/hr at certain onsite locations. The elevated exposure rates from sky-shine decreased rapidly with distance to levels indistinguishable from normal background measurements at even the nearest offsite monitoring stations. Also apparent in Figure 4.1-1 is the replacement of the historical Victoreen TLD monitoring system with the Panasonic system in year 2000. The difference in response between the two systems is very apparent, with the new Panasonic TLDs reading 15% to 20% lower. This lower response is consistent for all locations, including both indicator and control locations.

Figure 4.1-1 also relates the difference in critical indicator locations 1 and 3 and the annual average of all indicator TLDs to the annual average of the control TLDs collected and measured during coincident periods throughout the year. As discussed earlier, the exposure measurements of many indicator locations onsite (and two of the control locations) are influenced by natural background exposure differences caused by the many granite out-croppings typical of the local area. Figure 4.1-1 shows the annual average at indicator location 1 is slightly higher in gamma exposure rate than the average control gamma exposure rate. An opposite trend is shown for location 3. These differences are the result of the differences in granite at these locations. Location 3 was moved in the second quarter 2009 to minimize the effect of tree covering for the air sampler also located at this location.

The 2009 to 2011 data for location 3 shows an increase likely attributable to the being closer to granite at the new location.

In 2005 and 2006, there was a small increase noted at locations 5 and 8 caused by storage of the MPS2 replaced reactor head. As expected, this increase exhibited a decreasing trend because of radioactive decay. The head was shipped offsite for disposal in the fourth quarter 2006; the measured levels at these two locations have returned to the background levels measured prior to the head being placed in the storage area. Although not measurable, any resulting site boundary doses are bounded by dose rates from the radwaste storage areas and are discussed in Section 5.

4-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station Figure 4.1-:1 uRit Anrual Ganwu Exposure Rate - 20Year Hitory Oinucaw Loc 1 in~caw LMc 3 10 4.2 Air Particulate Gross Beta Radioactivity (Table 2)

Air is continuously sampled at seven inner ring (0 to 2 miles) locations and one control location (14 miles N) by passing it through glass fiber particulate filters. These samples are collected weekly and analyzed for gross beta radioactivity. Results are shown on Figure 4.2-1 and Table 2. Gross beta activity remained at levels similar to that seen over the last decade. Inner and control monitoring locations continue to show no significant variation in measured activities (see Figure 4.2-2). This indicates that any station contribution is not measurable.

There was a noticable increase in periods ending March 29, April 5 and April 12 at all locations including the control location #15. Although the detectable radioactivity could be attributed to operation of MPS, they are not a result of station operation given the following facts:

(1) The quantities of radioactive airborne effluents from MPS during other weeks in 2011 did not increase significantly compared to this three week period.

(2) The quantities of radioactive airborne effluents from MPS during 2011 did not increase significantly compared to the year 2010.

(3) The radioactivity detected in the indicator samples was also identified in the control sample.

(4) The periods of increased radioactivity coincide with that of 1-131 (see next section).

As such, the atypical detection of radioactivity in both indicator and control samples is credibly attributed to the trans-Pacific transport of airborne releases from Fukushima, Japan following the March 11, 2011 Tohoku earthquake and is not related to the operations of MPS.

4-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station Figure 4.2-1 Air Particulate Gross Beta Activity pCi/m3 Monthly Averages - 2011 0.02 1 Idiaors 0.0181 0.016-1 0.014-0.012 0.01 Veý Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 4.2-2 Indicato Air Particulate Gross Beta Activity pCi/m3 Control j Monthly Averages -5 Year Trend 0.03 0.025 0.02 0.015 WN 0.01 LV MW 9 9

ý 9 9 W Z W Z 0, Z 4.3 Airborne Iodine (Table 3)

Charcoal cartridges are included at all of the air particulate monitoring stations for the collection of atmospheric iodine. These cartridges are analyzed on a weekly basis for 1-131.

The only detectable levels of 1-131 seen in 2011 were for the periods ending March 29, April 5 and April 12. Although the detectable concentrations of 1-131 could be related to operation of MPS, they are not a result of station operation given the following facts:

(1) The quantities of radioactive airborne effluents from MPS during other weeks in 2011 did not increase significantly compared to this three week period.

(2) The quantities of radioactive airborne effluents from MPS during 2011 did not increase significantly compared to the year 2010.

(3) The radioactivity detected in the indicator samples was also identified in the control sample at Location #15.

4-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station (4) The periods of increased 1-131 coincide with that of beta radioactivity (see previous section).

As such, the atypical detection of these radionuclides in both indicator and control samples is credibly attributed to the trans-Pacific transport of airborne releases from Fukushima, Japan following the March 11, 2011 Tohoku earthquake and is not related to the operations of MPS.

4.4 Air Particulate Gamma (Table 4A-D)

The air particulate samples that are utilized for the weekly gross beta analyses are composited quarterly and analyzed for gamma emitting isotopes. The first two quarters were divided to see if there were any detectable activity due to the accident at Fukushima as was seen in gross beta radioactivity and 1-131 (see Sections 4.2 and 4.3). There was no noticable increase in the March or April/May results, the same period when there was an increased in gross beta radioactivity and 1-131. This suggests that the increased radioactivity from Fukushima was from 1-131. The results, as shown in Tables 4A - 4D, indicate the presence of naturally occurring Be-7, which is produced by cosmic radiation. No other positive results are seen. These analyses indicate the lack of station effects.

4.5 Air Particulate Strontium (Table 5)

Prior to 1989 Table 5 was used for listing the data for measurements of Sr-89 and Sr-90 in quarterly composite air particulate filters. The historical data indicated the lack of any detectable station related activity. Since these analyses are not listed in NUREG-1301 (Reference 15), these measurements were discontinued. In the event of widespread station related contamination or other unusual events, these measurements could be made.

Historically, when world events created conditions that caused detectable measurements of these nuclides, there was no difference noted between indicator and control locations. This further confirms that any of the detectable levels for these nuclides were not plant related.

4.6 Soil (Table 6)

MPS resumed collection of soil as a required media type in 2001. Prior to 2001, it had not been sampled for over fifteen years. These samples were discontinued due to the fact that, previous sample results never indicated any station related detectable activity. Similarly, since 2001, no station detectable activity has been seen in these samples. The results of these samples, allows for the determination of baseline activity levels in soil. This is particularly important for Cs-137, since significant levels from past weapons testing fallout remain in the soil. Baseline levels should be useful in the future, when site characterization and decommissioning of the station become the focus during preparations for License termination. This media is collected annually from one control and two indicator locations.

4.7 Cow Milk (Table 7)

Typically, the most sensitive indicator of fission product existence in the terrestrial environment is the radiological analysis of milk samples. Milk is a widely consumed food, therefore it is usually one of the most critical exposure pathways. Since 1996 all dairy (cow) farms close enough to MPS to be considered an indicator location (i.e. conservatively within 10 miles, reference 15 specifies within 5 miles) have ceased operation. One cow milk location at 10.4 miles from the plant is sampled as an extra (i.e.; not required) sample and results are shown in Table 7. Sr-89 and Sr-90 results in the June 30 sample and the 1-131 result in the April 7 sample may be an indication of positive radioactivity but the results are not statistically significant enough to warrant that judgement. Any positive results could be attributed to Fukushima (see discussions in Sections 4.3 and 4.4).

4-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 4.8 Goat Milk (Table 8)

When available, these samples are collected twice per month during grazing season and once per month during the rest of the year. Because of limited availability of goat milk only five samples were collected during 2011. Per requirements, pasture grass or feed is collected as a substitute when milk is not available (see 4.9. Pasture Grass and Feed). Each sample is analyzed for 1-131 and gamma emitting nuclides. Although not required by the REMODCM, samples from each location are composited quarterly and analyzed for strontium. Only one strontium analysis was performed in 2011 because of limited availability of sample.

Goat milk samples are typically a more sensitive indicator of fission products in the terrestrial environment than cow milk samples. It should be noted that the uptake of radionuclides in milk is dependent on a number of parameters. These include: metabolism of these animals, feeding habits, farming practices and feed type. Unlike previous years, Cs-137 and Sr-90 were not observed in goat milk. During past weapons testing periods, samples taken at certain milk locations indicated higher uptake of fallout than others. This was especially apparent in past samples collected in the immediate area around MPS (see previous Annual Operating Reports). One of these sites, located at 5.2 Mi. NNE of MPS (previous location 22, sampled from 1994 through 2004), exhibited a trend of showing higher Sr-90 and Cs-1 37 concentrations than at some of the other locations (including ones located closer to MPS).

MPS and regulatory authorities (e.g., see Reference 17) have carefully reviewed past and present data. The presence of the Sr-90 and Cs-137 is the result of residual radioactivity deposited into the environment from the fallout of past nuclear weapons testing. The facts that lead to this conclusion are presented in Section 6.0. These facts include: effluent release totals for these isotopes show insufficient quantities to account for such measurements; Sr-89 and Cs-134 which are chemically similar and generally released in comparable quantities were not detected, and a trend since the early 1960's that shows a consistent declining presence of Cs-1 37 and Sr-90 in milk from Connecticut.

The 2011 results indicate no detectable 1-131 in this media. The sample taken July 28 at Location #21 suggests a positive 1-131 but the MDC for the analysis of this sample was higher than the sample result (0.70 pCi/I vs. 0.52 pCi/I). In the 1970's and 1980's low levels of plant related 1-131 were seen in some of these samples. However, for over 19 years, no plant related detectable levels of 1-131 have been seen in goat milk samples. The only other occasions where 1-131 was detected were fallout episodes from the Chinese Weapons Tests of the mid to late 1970's and Chernobyl Accident in 1986. There was no detectable 1-131 from the Fukushima event; but, samples were not available in late March and early April when radioactivity from Fukushima was detected in other environmental samples (see discussions in Sections 4.2 and 4.3).

4-6

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 4.9 Pasture Grass and Feed (Table 9)

When the routine milk samples are unavailable, samples of pasture grass are required as a replacement. These samples may also be taken to further investigate the levels of radioactivity in milk. During the winter months and early spring, insufficient growth often prohibits sampling of pasture grass. Feed (e.g., hay or grain) is typically sampled whenever pasture grass is not available.

No station effects are noted in these samples. Cosmic produced Be-7 was observed in the majority of the pasture grass samples and many of the hay samples. Due to its relatively short half-life (52 days), it was not detected in the several of the "older" hay samples.

Naturally occurring K-40 was approximately two times higher in hay compared to pasture grass samples.

4.10 Well Water (Table 10)

These samples were discontinued in 1985, because no detectable station activity was ever observed in these samples. However, based upon lessons learned at other nuclear plants, including several undergoing decommissioning, sampling was resumed at several locations starting in the fourth quarter 2003. Three additional locations were added in 2005 to monitor potential leakage from the ISFSI. Due to the heightened sensitivity on this potential pathway, three more locations were added in 2006, five more in the summer of 2008 and two more in the Fall of 2010. One of the newer wells, location 86 (GPI 6 - inside the MPS3 RCA between the Boron and Waste Test Tank berm and the Fuel Building) indicated a positive tritium (H-3) result (2310 +/- 250 pCi/liter) on August 28, 2008. This was the first sample from this new well. The temporary well located nearby also indicated positive levels (see 2008 Annual Radiological Environmental Operating Report and the 2008 Radiological Effluent Report) due to penetrations in the berm and a leaky pressure gauge for one of the Boron Recovery Tanks. The penetrations have been sealed and the pressure gauge repaired. The H-3 levels have since become undetectable at this location.

The H-3 result at Location 81 on June 13 (992 +/- 670 pCi/I) was below it's MDC of 1020 pCi/I. Consistent with the data of previous years, there were no incidents of any station activity detected in these samples.

4.11 Reservoir Water or Deer Meat (Table 11)

Reservoir water samples are special samples not required by the REMP. Previous data has shown the lack of detectable station activity in this media. This fact and the extremely unlikely possibility of observing routine station effluents in this media have resulted in discontinuing these samples. In the event of widespread station related contamination, these samples may be collected.

Deer meat was a new sample type initiated at the end of 2010 but has been discontinued.

4.12 Fruits and Vegetables (Table 12)

Consistent with past years, this media did not show any station effects. Naturally occurring Be-7 was detected in some samples and K-40 in all samples.

4-7

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 4.13 Broad Leaf Vegetation (Table 13)

Consistent with past years, this media did not show any station effects. All samples had detectable levels of cosmic produced Be-7 and naturally occurring K-40 at levels consistent with previous years. Occasionally these samples indicate positive levels of Cs-137. This can be attributed to fallout from weapons testing which has been widespread in terrestrial samples for many years.

This media can be an early and sensitive indicator of releases from the station for both unplanned releases and normal operations. Therefore, to enhance program-monitoring effectiveness, samples of broadleaf vegetation are collected monthly during the growing season, May - October, even though requirements are to collect this media twice a year.

4.14 Seawater (Table 14)

The guidance in Reference 15 specifies one sample upstream (control - beyond significant influence of the discharge) and one sample downstream (indicator - beyond but near the mixing zone) for surface water samples. Historically the downstream sample for MPS has been located in the vicinity of discharge (location 32 - see Reference 8) which is prior to the mixing zone. This location was chosen since it was readily accessible and not affected by cold weather conditions. Operation of an automatic sampler at the indicator location is necessary for providing a representative sample. Although samples obtained at this location actually monitor the undiluted discharge activity, it provides for an excellent check on the radioactive effluent monitoring program. Any dose consequences can be assessed by use of the appropriate dilution factors. It's not as necessary to have a continuous sampler at the control location due to the historical relative consistency noted in seawater background activity near the MPS.

A technician collects an aliquot from the automatic sampler at Location 32 on a weekly frequency. These samples are composited for monthly analyses. In September 1999, MPS increased the required analysis frequency for this composite sample to monthly to increase monitoring effectiveness. For the Control Location, Giant's Neck (Location 37C), six weekly grab samples are obtained for quarterly compositing. In 2003, the LLD for H-3 (tritium) at the indicator location (32) was lowered by approximately a factor of four to further enhance monitoring effectiveness. This lower LLD was continued through 2011.

Naturally occurring K-40 was the only detectable gamma activity seen in several of these samples. Results for Co-58 on Aug 30 and for Co-60 on March 29, although greater than the 2a error, were less than their MDC. Measured plant related levels of H-3 inseawater from the immediate vicinity of discharge (location 32) were observed in all samples except in December. Both MPS2, in April, and MPS3, in October had refueling outages. Tritium releases are typically higher near these outages due to the need for increased liquid processing during these times. As mentioned above, these samples are taken directly from liquid effluent flow prior to dilution into the Long Island Sound. Dilution studies performed for this discharge have determined that a dilution factor of 3 is appropriate to estimate concentrations immediately outside the quarry within a near-field area.

Tritium builds up in the reactor coolant during each fuel cycle. It is generated during plant operation from fission and neutron reactions. Between 1992 and 2002, H-3 was not typically detected. However, due to the enhanced detection sensitivity, H-3 levels are now often detected at the indicator location. Figure 4.14-1 shows an eighteen-year trend of H-3 releases in the MPS liquid effluents versus the measured environmental concentrations from the vicinity of discharge location.

4-8

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station Figure 4.14-1 H-3 Curies Released versus Seawater Concentration 18 Year Trend 1700 1600 - Curies discharged 1500o 1400 - REMP pCiiliter 1300 1200 1100-10009 900-800 700 T 600-500-300 . f !1--I I~ Ill 4 MIIM II 400Ao"I I I I lk 300 2!00 100 0

4.14 Bottom Sediment (Table 15)

There was no plant related radioactivity detected in bottom sediment samples in 2011.

Naturally occurring K-40 is seen in all samples Some results are greater than their 2a error but all are less than the MDC.

Bottom sediment is not a significant dose pathway to man, especially at areas not typically used by the public. Examinations of other aquatic media, including seafood, sampled from near these locations (discussions that follow) do not show any detectable Co-60 or Cs-1 37.

4.15 Aquatic Flora (Table 16)

Although sampling of this media is not required, it provides useful information since it a very sensitive indicator of radioactivity in the environment. Naturally occurring Be-7 and Th-232 decay chain appears in some samples and K-40 in all samples. Low levels of man-made radioactivity (e.g., Mn-54, Co-58, Co-60, Zn-65, 1-131 and Ag-1 1Om) have been detected in the past. Since 2000, levels have decreased to undetectable for all nuclides except for 1-131.

Some results are greater than their 2a error but less than the MDC. The results for Co-58 on May 25 for Location #32 (Vicinity of Discharge) was greater than the MDC but further analyses determined that it was a false positive identification.

Seaweed has a significant bioaccumulation factor for iodine which makes it an extremely sensitive indicator of iodine in the environment. Three positive, plant-related 1-131 measurements were noted in 2011, one on March 23 at Location #32 which is Vicinity of Discharge and two on March 23 and September 27 at Location #29 which is in Jordon Cove just downstream of discharge. The measurements are consistent with 1-131 seen in liquid effluents reported for the first three quarters of 2011. Release of 1-131 in liquid effluents were well below regulatory limits and environment concentrations are comparable to some prior years at the same locations.

4-9

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 4.16 Fish (Tables 17A and 17B) 4.16.1 Flounder (Table 17A)

The activity in Flounder is the same as that seen for the past decade. No activity was observed except for the naturally occurring K-40.

4.16.2 Fish - Other (Table 17B)

The activity in other fish is the same as that seen for the past decade. No activity was observed in this media except for naturally occurring K-40.

4.17 Mussels (Table 18)

Similar to the last several years, this sampling media showed no activity except for the naturally occurring K-40.

4.18 Oysters (Table 19)

All locations utilize oysters stocked in trays. The oysters used for stocking these trays have been obtained from Ram Island for the last several years. To confirm that the stocked oysters are not initially contaminated, the oysters from Ram Island are also analyzed. The stocked trays are kept at most of the sampling areas to guarantee samples and facilitate sample collection. Historically, native oysters were sampled at the quarry (location 40X),

which was an extra location. Due to safety concerns about diving operations, sampling at location 40X was suspended after the 2 nd quarter 2007 samples. Similarly, due to other safety concerns, location 32 was moved to a more accessible area in the middle of the quarry. Although it is labeled as vicinity of the discharge, it was previously located at the end of the quarry.

MPS related Ag-1 10m was detected in samples from location 32. This has been an historical occurrence (see discussion below).

For several previous years, high levels of Zn-65 were observed in oysters. This was caused by their high capacity for accumulating zinc. Studies have shown that oysters can accumulate as much as 50 times or more the amount of zinc compared to most other seafood (Wolfe, 1979). A remarkable correlation existed between the Zn-65 concentration measured in the native quarry oysters and the amount of Zn-65 discharged into the environment. However, since the permanent shutdown of MPS1 in 1996, the amount of Zn-65 in liquid effluents has decreased significantly. Starting in 2001, no Zn-65 has been detected in either the liquid effluents or in oysters. Figure 4.19-1, shows a historical trend that existed between Zn-65 releases and measured concentrations in quarry oysters. The decreasing trend in effluent radioactive releases is apparent in both the curies released and the measured concentrations in oysters.

4-10

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station Figure 4.19-2 shows the trend of Ag- 1O1m concentration in quarry oysters compared to the liquid effluents discharged. Similar to Zn-65, the correlation between Ag-1 1Om discharged and the Ag-1 1Om concentration measured in the native quarry oysters is apparent. Section 5 provides for a comparison of doses based upon effluent measurements (method 1) to doses based upon environmental measurements (method 2). Per regulatory guidance (reference 7), the bioaccumulation factors for both Zn and Ag were adjusted based upon several years of historical data to account for the higher measured uptakes. These adjustments have typically shown good agreement between the two methods, with method 1 usually being conservative. The 2006 and 2007 data indicate an unusual trend (see Section 5, Table 5-2).

Method 2 (REMP dose assessment) indicates higher doses than method 1 (effluent dose assessment). Due to significant effluent reductions over the last several years, the low resulting doses (less than 0.01 mrem) make this comparison difficult and subject to significant error. Trending of these comparisons is routinely performed and adjustments are made, if appropriate.

The location of the quarry is on-site and not available for public use. No MPS activity was observed at locations beyond the MPS discharge area. Therefore, the actual concentration of the nuclides in oysters available for public consumption is much less than the levels found inside the quarry. The near-field dilution factor for liquid discharges from the Millstone Quarry discharge is a factor of 3.

Figure 4.19-1 Zn-65 COMPARISON Curies Curies Discharged vs. Native Oyster Concentration pCilgram 0.1 100

- Curies Discharged 0.01 Oyster Conc.

0.01 -10 0.001 1 0.0001 0.1 0.00001 0.01 0.000001 -0.001 Quarter 4-11

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station Figure 4.19-2 Ag-110m COMPARISON Curms Curies Discharged vs. Native* Oyster Concentration pCigram 0.1 100 W~ YW -- Curies Discharged 0.01 Oyster Conc. 10 0.001 1 0.0001 0.1 0.00001 -0.01 0.000001 0.001 Quarter

• Native oysters until 3Q 2007; because of diver safety issues now the only oysters sampled in the Quarry are stocked in trays similar to what has historically been performed at all the other locations.

4.20 Clams (Table 20)

Occasionally this media indicates the presence of station related radioactivity. No activity was observed except for the naturally occurring K-40.

4.21 Scallops (Table 21)

Scallops are not required by the REMP. However, attempts are made to sample this media to confirm station effects because scallops could be available for public consumption. No scallop samples have been available for several years.

4.22 Lobsters (Table 22)

No activity was observed except for the naturally occurring K-40.

4-12

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

5. OFFSITE DOSE EQUIVALENT COMMITMENTS The off-site dose consequences (dose equivalent commitments) of the station's radioactive liquid and airborne effluents have been evaluated using two methods.

The first method utilizes calculations of direct dose from sources onsite and the station's measured radioactive discharges as input parameters into conservative models to simulate the transport mechanism through the environment to man. This results in the calculation of the maximum dose consequences to individuals. The results of these computations have been submitted to the NRC in the RERR written in accordance with the REMODCM. This method, which is usually conservative (i.e., computes higher doses than that which actually occur), has the advantage of approximating an upper bound to the dose consequences. This is important in those cases where the actual dose consequence cannot be measured because they are so small as to be well below the capabilities of conventional monitoring techniques.

The second method utilizes the actual measurements of the concentrations of radioactivity in various environmental media (e.g., fish, shellfish) and then computes the dose consequences resulting from the consumption of these foods.

The results of both methods are compared in Table 5.1 for those pathways where a potential dose consequence exists and a comparison is possible. The doses presented in this table are calculated at the location of maximum effect from the MPS effluents for that pathway and for the critical age group. For example, the external gamma dose from gaseous effluents is calculated for the site boundary location which is not only the nearest but also has the greatest directional wind frequency and fish and shellfish doses are calculated assuming they are from an area within 500 feet of the station discharge.

The majority of the whole body dose is due to a conservative determination of dose (=0.22 mrem) to the nearest resident as a result of direct radiation from on-site radioactive waste operation/storage facilities and continuous occupancy. Since the maximum dose consequence to an individual is at the location of highest dose consequence, doses will be less for all other locations. The average whole body dose to an individual within 50 miles historically is on the order of 1000 times less than the maximum individual whole body dose.

In order to provide perspective on the doses in Table 5.1, the standards on the allowable maximum dose to an individual of the general public are given in 40 CFR 190 as 25 mrem whole body, 75 mrem thyroid, and 25 mrem to any other organ. These standards are a fraction of the normal background radiation dose of approximately 311 mrem per year and are designed to be inconsequential in regard to public health and safety. Since station related doses are even a smaller fraction of natural background, they have insignificant public health consequences. In fact, the station related doses to the maximum individual are less than 10% of the variation in natural background.

5-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 5.1 COMPARISON OF DOSE CALCULATION METHODS Millstone Power Station 2011 Annual Dose (mrem)

Method 1 (1) Method 2(1)

Pathway Individual Organ MPS1 MPS2 MPS3 Station Station (BWR) (PWR) (PWR) Total Airborne Effluents

1. External Gamma Dose Max(2) Whole Body 0.00000 0.00121 0.00016 0.00137 ND(3)

(gamma air) (8)

2. Whole Body Dose Max(2) Whole Body 0.005 0.140 0.125 0.270 ND (internal and external)

3. Inhalation, vegetables, meat Max~2) Thyroid 0.005 0.148 0.126 0.279 ND and milk

4. Inhalation, vegetables, meat Max(2) Max Organ 0.005 0.692 0.588 1.285 ND and milk Direct Dose Nearest Residence Max(2) Whole Body N/A N/A N/A -0.22(4) <0.4(5,8) 5-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE 5.1 (Cont.)

COMPARISON OF DOSE CALCULATION METHODS Millstone Power Station 2011 Annual Dose (mrem)

Max Method 1(1) Method 2(1)

Pathway Individual Organ MPSI MPS2 MPS3 Station Station (BWR) (PWR) (PWR) Total Liquid Effluents

1. Fish

• Adult Whole Body 0.00000 0.00050 0.00048 0.00098 ND(3)

Teen 0.00000 0.00046 0.00043 0.00089 Child 0.00000 0.00052 0.00044 0.00096

" Adult G1(LL)(6) 0.00000 0.00253 0.00317 0.00570 ND Teen 0.00000 0.00185 0.00158 0.00343 Child 0.00000 0.00073 0.00068 0.00141 Adult Bone 0.00000 0.00295 0.00126 0.00421 ND Teen 0.00000 0.00308 0.00132 0.00440

" Child 0.00000 0.00403 0.00172 0.00575

2. Shellfish Adult Whole Body 0.00000 0.00051 0.00039 0.00090 0.00002(7)

Teen 0.00000 0.00053 0.00039 0.00092 0.00002

• Child 0.00000 0.00069 0.00047 0.00116 0.00002

• Adult GI(LLI) 0.00000 0.00430 0.00322 0.00752 0.0110 Teen 0.00000 0.00308 0.00229 0.00537 0.0077 Child 0.00000 0.00117 0.00088 0.00205 0.0028 Adult Bone 0.00000 0.00334 0.00151 0.00485 0.00003 Teen 0.00000 0.00348 0.00158 0.00506 0.00003

" Child 0.00000 0.00473 0.00214 0.00687 0.00003 5-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Notes:

1. Except for direct dose, method 1 uses measured station discharges and meteorological data as input parameters to transport-to-man models that conservatively calculate dose to people; method 2 uses actual measured concentrations in environmental media to estimate the dose.

2. Maximum individual - The maximum individual dose is the dose to the most critical age group at the location of maximum concentration of MPS related activity. The dose to the average individual is much less than the maximum individual dose.

3. ND - Not Detectable - No MPS related activity could be detected above natural background or above the minimum detectable level (MDL).

4. The dominant source of direct dose from the MPS is from storage and movement of radioactive waste. Each facility is monitored onsite by the Radiation Protection Department using TLDs. The exposure measured for each facility TLD was corrected for distance to the nearest site boundary residence. The resultant exposure was conservatively multiplied by 1.5 to account for sky-shine. These maximum estimated doses from each facility were summed for a cumulative site commitment of approximately 0.22 mrem.

5. Measured dose was derived from monthly TLD readings. There are two residences that qualify as the closest residence; each has a TLD near enough to use as an estimate to each residence. The one with the highest average dose rate was used to estimate the direct dose to the closest residence. A background dose rate was subtracted. This background was derived from the average of the five control TLD locations. This method is very conservative assuming natural exposure influences, such as granite, are actually plant related exposure. This method provides a bounding high value. The exposure measurements of the select indicator locations are influenced by natural background exposure differences caused by the many granite out-croppings typical of the MPS area.

Historical data has shown that TLD sample locations in the vicinity of granite can be dramatically influenced by natural radioactivity contained within the granite.

6. GI - Gastrointestinal Tract.

7. Based on measured levels of Ag-11Om in the native quarry oysters. A measured near field dilution factor of 3 was used to adjust for the fact that these oysters are on-site and inaccessible to the public. This factor adjusts the measured on-site concentration to that which could occur to a public accessible off-site location after dilution of the effluent by the Long Island Sound. The measured levels in the stocked oysters within the quarry were about one-half the native quarry oysters. For conservatism, it was assumed the maximum individual consumed primarily oysters (activity in clams was much lower than in the oysters).

8. Based upon the conservatively assuming no correction for building shielding and occupancy.

5-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

6. DISCUSSION The evaluation of the effects of MPS operation on the environment requires the careful consideration of many factors. Those factors depend upon the media being affected. They include MPS release rates, effluent dispersion, occurrence of nuclear weapons tests, seasonal variability of fallout, local environment, and locational variability of fallout.

Additional factors affecting the uptake of radionuclides in milk include soil conditions (mineral content, pH, etc.), quality of fertilization, quality of land management (e.g., irrigation),

pasturing habits of animals, and type of pasturage. Any of these factors could cause significant variations in the measured radioactivity. A failure to consider these factors could cause erroneous conclusions.

Consider, for example, the problem of deciphering the effect of MPS releases on the radioactivity measured in milk samples. Some of these fission products, such as 1-131 and Sr-89 are relatively short-lived. Therefore they can result from MPS effluents, nuclear weapons tests or nuclear incidents (e.g. Chernobyl, Fukushima). Sr-89's lifetime is longer than 1-131's, therefore it will remain around for much longer periods of time. The even longer-lived fission products, Sr-90 and Cs-137, cause more of a concern. These isotopes are still remaining from the weapons testing era of the 1960's. This results in measurable amounts of Sr-90 and Cs-137 appearing in past milk samples. Distinguishing between this "background" of fallout activity and MPS effects is of prime interest for a REMP.

In reviewing the historical Sr-90 and Cs-137 measured in cow and goat milk in the areas around MPS, a casual observer could notice that in some cases the levels of these isotopes are higher at farms closer to the MPS than at those further away from the MPS. The MPS's effluents might at first appear to be responsible. However, the investigation of the following facts proves this conclusion wrong.

(1) Nuclear power stations measure many fission products, including Sr-90 and Cs-137 in their releases. Based on these measurements and proven models developed by the NRC, concentrations in the environment can be calculated. These calculations (generally conservative, see Section 5.0) show that insufficient quantities of Sr-90 and Cs-137 have been released from the plants to yield the measured concentrations in milk.

(2) Over the many years of MPS operation, Sr-89 has often been released in comparable quantity to Sr-90. Since they are chemically similar, comparable levels should have been detected in milk if the Sr-90 was MPS related. No MPS related Sr-89 has ever been detected in milk samples.

(3) Similar to Sr-89, Cs-1 34 can be used as an indication of MPS related Cs-137. Although not as conclusive as Sr-89, the lack of any measurable Cs-1 34 in any of the milk samples suggests that the Cs-1 37 is not MPS related. This is further confirmed by the evaluation of the air particulate data. The only occurrences of detectable Cs-134 in milk resulted from the Chernobyl incident.

(4) Dairy milk sampling in Connecticut began in the 1960's, several years prior to MPS operation. The highest levels of weapons fallout related Sr-90 and Cs-137 (see Figures 6-1 and 6-2), were measured in the years prior to MPS operation. Samples taken in the immediate areas have always shown higher levels of weapons related fallout than samples taken from the Central Connecticut Region (CT Pooled Milk). Radioactivity levels of fallout related Sr-90 and Cs-137 have decreased significantly since the 1964 Nuclear Test Ban Treaty due to decay.

6-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 (5) Local variability of Sr-90 and Cs-137 in milk is common throughout the United States.

Due to the variability in soil conditions, pasturing methods, rainfall, etc., it is the rule rather than the exception. Therefore, it is not surprising that certain farms have higher levels of radioactivity than other farms. In fact, in the past there are some cases where the farms further from the MPS have higher Sr-90 and Cs-1 37 values than the farms that are closer to the MPS.

(6) In the past when a goat farm operated near MPS (2.0 Mi - ENE), the highest levels of Sr-90 and Cs-137 were typically indicated. This same farm also experienced the highest levels of short-lived activity from the 1976 and 1977 Chinese Tests and the 1986 Chernobyl accident. This indicates that for some unknown reason this farm had the ability for higher reconcentration. Special studies performed at this and other farms failed to find any link to the MPS.

Based on these facts, the observation that the MPS effluents are responsible is evidently false. The cause must be one or more of the other variables.

Dominion has carefully examined the data throughout the years and has presented in this report all cases where MPS related radioactivity could be detected. An analysis of the potential exposure to the maximum individual from any MPS related activity has been performed and shows that in all cases the exposure is insignificant.

The Connecticut Department of Energy and Environmental Protection (DEEP) performs an independent check on certain environmental program analyses. The results of their analyses are comparable to the results from this program's analyses. These comparisons can be used as a cross-reference to verify measured MPS activity. DEEP performed a comprehensive review of all the historical MPS data in 2006 (reference 17). It concluded that "the collective sampling in and around Millstone Power Station show expected levels of residual fallout from weapons testing and the Chernobyl event and are unrelated to the operation of the Millstone Power Station."

Figure 6-1 Strontium-90 in Milk pCi/liter 25

---

CT Pooled 20 - Haddam ar 15 MPS area I 15 10 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 Year 6-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 Figure 6-2 Cesium-137 in Milk pCi/liter 160 -

140 120 100 80 60 40 20 0

61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 Year Dairy milk is no longer available in the MPS area, Haddam Neck no longer collects milk, and CT Pooled milk has not been collected by the State of CT since 1994. Graphs provided to show historical trends.

CY Start-up occurred: July 24,1967 MPS2 Start-up occurred: December, 1975 MPS1 Start-up occurred: October 26,1970 MPS3 Start-up occurred: January 23,1986 6-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011

7. REFERENCES

1) United States of America, Code of Federal Regulations, Title 10, Part 50, Appendix A Criteria 64.

2) Donald T. Oakley, "Natural Radiation Exposure in the United States." U. S.

Environmental Protection Agency, ORP/SID 72-1, June 1972.

3) National Council on Radiation Protection and Measurements, Report No. 160, "Ionizing Radiation Exposures of the Population of the United States," March 2009.

4) National Council on Radiation Protection and Measurements, Report No. 94, "Exposure of the Population of the United States and Canada from Natural Background Radiation,"

December 1987.

5) United States Nuclear Regulatory Commission, Regulatory Guide 8.29, "Instructions Concerning Risks from Occupational Radiation Exposure," Revision 0, July 1981.

6) Millstone Training Brochure.

7) United States Nuclear Regulatory Commission, Regulatory Guide 1.109, "Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I," Revision 1, October 1977.

8) Millstone Power Station Radiological Effluent Monitoring and Offsite Dose Calculation Manual, Revision 026-02, March 15, 2011.

9) United States of America, Code of Federal Regulations, Title 10, Part 20.1301.

10) United States of America, Code of Federal Regulations, Title 10, Part 50, Appendix I.

11) United States of America, Code of Federal Regulations, Title 40, Part 190.

12) United States Nuclear Regulatory Commission, Regulatory Guide 4.1, "Program for Monitoring Radioactivity in the Environs of Nuclear Power Plants," Revision 1, April 1975.

13) ICN/TracerLab, "Millstone Nuclear Power Station Pre-operational Environmental Radiation Survey Program, Quarterly Reports," April 1967 to June 1970.

14) International Commission of Radiological Protection, Publication No. 43, "Principles of Monitoring for the Radiation Protection of the Population," May 1984.

15) United States Nuclear Regulatory Commission, NUREG-1301, "Offsite Dose Calculation Manual Guidance: Standard Radiological Effluent Controls for Pressurized Water Reactors," April 1991.

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

17) Reassessment of Millstone Power Station's Environmental Monitoring Data, Connecticut Department of Environmental Protection, Division of Radiation, March 2006.

18) Nuclear Regulatory Commission Regulatory Guide 4.1, Radiological Environmental Monitoring for Nuclear Power Plants, Revision 2, June 2009.

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 APPENDIX A LAND USE CENSUS FOR 2011 A-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 INTRODUCTION The annual land use census in the vicinity of MPS was conducted as required by the MPS REMODCM. Typically the cow milk locations are identified by a review of the annual registration information obtained from the State of Connecticut Department of Agriculture.

Gardens are located by a drive-by during the harvest season. Although broadleaf sampling was performed and may be used in lieu of a garden census, gardens were included in the 2011 census. Only vegetable gardens having an area of more than 500 square feet need to be identified. In order to reduce some of the conservatism of the dose modeling, a more detailed census was initiated in 2010 to identify locations of fruits. Due to the difficulty of measuring individual gardens, the nearest garden within each directional sector identified by a drive-by survey is listed. Goat locations are more difficult to determine, but best efforts are made to consult goat association records, contact previous owners and or drive-bys, if necessary.

RESULTS Tables A-1 through A-3 indicate information from the latest land use census. No new dairy animals within 10 miles of the MPS were located during the census. Several changes were identified, these include:

• Several locations changed since the distances were more accurately determined

" ten new cow dairy locations were identified, all beyond 20 miles (only locations within 20 miles are identified in Table A-I)

" several new gardens were identified These changes indicate that no changes were required in the current sampling locations.

The dose modeling incorporates the above listed changes.

A-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE A-1 Dairy Cows Within 20 miles of Millstone Power Station - 2011 Direction Distance (Miles) Location N 14.9 Norwich N 18.0 Bozrah N 18.5 Franklin N 19.2 Norwich N 19.4 North Franklin N 19.4 Franklin N 19.6 North Franklin NNE 15.1 Preston NNE 15.8 Preston NNE 16.2 Preston NNE 16.3 Norwich NNE 17.5 Preston NNE 17.8 Preston NE 13.5 Ledyard NE 13.6 Ledyard NE 14.4 Ledyard NE 14.4 North Stonington NE 14.4 Preston NE 19.2 North Stonington NE 19.2 North Stonington ENE 17.9 North Stonington WNW 10.5 Lyme NW 10.4 Lyme NW 12.6 Salem NNW 12.2 Salem NNW 19.5 Lebanon NNW 19.6 Lebanon Note: None of these cow farms are used for sampling since all farms are greater than ten miles from plant (NUREG 1301, Reference 15, uses a cutoff distance of 5 miles)

A-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE A-2 Dairy Goats Within 20* miles of Millstone Power Station - 2011 Direction Distance (Miles) Location (Sample Location)

N 2.1 Waterford (LOCATION 21)**

N 11.1 Oakdale NE 2.8 Waterford (LOCATION 22)***

ENE 11.8 Stonington ENE 12.8 Stonington WNW 17.6 Haddam NW 16.9 East Haddam NNW 12.2 Salem NNW 18.1 Colchester NNW 20.8 Colchester NNW 28.6 Hebron (LOCATION 24)

• plus one control location at 28.6 miles

• • primarily for cheese, occasionally milk for drinking not milking, raised for meat only, pigs also at this location A-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TABLE A-3 2011 Resident/Garden Survey Downwind Resident +

Garden Fruit Direction miles meters miles meters miles meters N 0.97 1,570 0.98

• 1,580 1.9 2,980 NNE 0.53 850 0.55 890 12 19,750 NE 0.46 740 0.50 800 12 19,830 ENE 0.97 1,570 0.97

• 1,570 9.6 15,510 E 0.90 1,450 0.95

• 1,530 ESE 1.1 1,700 1.2 1,970 SE N/A N/A N/A N/A N/A N/A SSE N/A N/A N/A N/A N/A N/A S N/A N/A N/A N/A N/A N/A SSW N/A N/A N/A N/A N/A N/A SW 2.3 3,680 2.5* 3,950 WSW 2.0 3,190 2.0* 3,190 W 1.8 2,850 1.9 3,090 11 17,830 WNW 1.6 2,500 1.7 2,740 5.3 8,450 NW 0.52 840 1.5" 2,390 5.5 8,770 NNW 0.51 820 0.76 1,220

• new locations A-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 APPENDIX B

SUMMARY

OF INTERLABORATORY COMPARISONS

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 INTRODUCTION This appendix covers the Intercomparison Program of the Teledyne Brown Engineering Laboratory as required by technical specifications for each MPS unit. Teledyne uses QA/QC samples provided by Eckert & Ziegler Analytics, by the Environmental Resource Associates (ERA) Proficiency Test (PT)

Program and by the Department of Energy (DOE) Mixed Analyte Performance Evaluation Program (MAPEP) to monitor the quality of analytical processing associated with the REMP. The suite of samples are comparable with the pre-1996 US EPA Interlaboratory Cross-Check Program in terms of sample number, matrices, and nuclides. It includes:

• milk for gamma (9 nuclides) analyses once per quarter

" milk for low level Iodine-1 31 analyses once per quarter

• milk for Sr-89 and Sr-90 analyses once per quarter

• water for gamma (9 nuclides) once per quarter

" water for low level Iodine-1 31 analyses twice per year

• water for tritium analyses once per quarter

• water for Sr-90 analyses once per quarter

• water for gamma Sr-89 analyses twice per year

• air filter for gamma (9 nuclides) analyses once per quarter

" air filter for gross beta analysis twice per year

• charcoal filter for 1-131 once per quarter

• air filter for Sr-90 analyses twice per year

• soil for gamma (10 nuclides) analyses twice per year

" vegetation for gamma (6 nuclides) analyses twice per year

• vegetation for Sr-90 analyses twice per year RESULTS Intercomparison program results are evaluated using the laboratory's internal bias acceptance criterion.

Teledyne Brown's acceptance criterion is defined as within 20% of the known value. Sample results which are less or greater than 20% of the known value but within 30% is acceptable with warning.

Samples results outside 30% of the known value are not acceptable. All sample analyses which are not acceptable are investigated. Teledyne Brown Engineering Intercomparison Program results are included on pages B-3 through B-6 for 2011.

A total of 180 analysis results were obtained by Teledyne Brown Engineering with 173 within acceptable criteria, a 96% success rate. Results of investigations are noted at the end of the following tables.

B-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TELEDYNE BROWN ENGINEERING, INC. ENVIRONMENTAL LABORATORY 2011 ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM Identification Reported Known Ratio (c)

Month/Year Number Matrix Nuclide Units Value (a) Value (b) TBE/Analvtics Evaluation (d)

March 2011 E7460-396 Milk Sr-89 pCi/L 98.8 97.4 1.01 A Sr-90 pCi/L 15.2 15.8 0.96 A E7461-396 Milk 1-131 pCi/L 92.9 96.9 0.96 A Cr-51 pCi/L 398 298 1.34 N (1)

Cs-1 34 pCi/L. 130 130 1.00 A Cs-137 pCi/L 232 205 1.13 A Co-58 pCi/L 121 113 1.07 A Mn-54 pCi/L 289 266 1.09 A Fe-59 pCi/L 201 175 1.15 A Zn-65 pCi/L 287 261 1.10 A Co-60 pCi/L 186 172 1.08 A E7463-396 AP Cr-51 pCi 243 215 1.13 A Cs-1 34 pCi 85.0 94.2 0.90 A Cs-1 37 pCi 168 148 1.14 A Co-58 pCi 89.2 81.8 1.09 A Mn-54 pCi 171 192 0.89 A Fe-59 pCi 129 126 1.02 A Zn-65 pCi 159 189 0.84 A Co-60 pCi 132 124 1.06 A E7462-396 Charcoal 1-131 pCi 96.5 96.3 1.00 A June 2011 E7851-396 Milk Sr-89 pCi/L 96.7 103 0.94 A Sr-90 pCi/L 13.8 15.6 0.88 A E7852-396 Milk 1-131 pCi/L 110 103.0 1.07 A Ce-141 pCi/L 68.1 79.9 0.85 A Cr-51 pCi/L 186 206 0.90 A Cs-134 pCi/L 164 190 0.86 A Cs-137 pCi/L 140 138 1.01 A Co-58 pCi/L 141 152 0.93 A Mn-54 pCi/L 136 138 0.99 A Fe-59 pCi/L 128 123 1.04 A Zn-65 pCi/L 263 261 1.01 A Co-60 pCi/L 189 195 0.97 A E7854-396 AP Ce-141 pCi 49.9 42.9 1.16 A Cr-51 pCi 95.6 110 0.87 A Cs- 134 pCi 104 102 1.02 A Cs-1 37 pCi 83.8 74.0 1.13 A Co-58 pCi 90.7 81.3 1.12 A Mn-54 pCi 74.5 73.9 1.01 A Fe-59 pCi 62.0 66.1 0.94 A Zn-65 pCi 140 140 1.00 A Co-60 pCi 119 104 1.14 A E7853-396 Charcoal 1-131 pCi 76.2 86.1 0.89 A (1) Sample appearsto be biased high. CorrectiveAction evaluated after the 2nd QuarterAnalytics PE sample; no action required. NCR 11-13 (a) Teledyne Brown Engineeringreportedresult.

(b) The Analytics known value is equal to 100% of the parameterpresent in the standardas determined by gravimetric and/or volumetric measurements made duringstandardpreparation.

(c) Ratio of Teledyne Brown Engineering to Analytics results.

(d) Analytics evaluation based on TBE intemal QC limits: A= Acceptable. Reported resultfalls within ratio limits of 0. 80-1.20.

W-Acceptable with waming. Reported result falls within 0.70-0.80 or 1.20-1.30. N = Not Acceptable. Reported resultfalls outside the ratio limits of < 0. 70 and > 1.30.

B-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Milstone Power Station 2011 TELEDYNE BROWN ENGINEERING, INC. ENVIRONMENTAL LABORATORY 2011 ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM Identification Reported Known Ratio (c)

MonthlYear Number Matrix Nuclide Units Value (a) Value (b) TBE/Analytics Evaluation (d)

September 2011 E8070-396 Milk Sr-89 pCi/L 102 90.8 1.12 A Sr-90 pCi/L 13.2 14.7 0.90 A E8071-396 Milk 1-131 pCi/L 74.2 89.2 0.83 Ce-141 pCi/L 66.9 66.7 1.00 Cr-51 pCi/L 249 226 1.10 Cs-134 pCi/L 116 128 0.91 Cs-137 pCi/L 106 114 0.93 Co-58 pCi/L 95.4 97.5 0.98 Mn-54 pCi/L 147 151 0.97 Fe-59 pCi/L 53.1 54.8 0.97 Zn-65 pCi/L 175 180 0.97 Co-60 pCi/L 150 157 0.96 E8073-396 AP Ce-141 pCi 66.6 67.5 0.99 Cr-51 pCi 263 229 1.15 Cs-134 pCi 139 130 1.07 Cs-137 pCi 110 115 0.96 Co-58 pCi 108 98.6 1.10 Mn-54 pCi 152 153 0.99 Fe-59 pCi 57.5 55.5 1.04 Zn-65 pCi 190 183 1.04 Co-60 pCi 156 159 0.98 E8072-396 Charcoal 1-131 pCi 77.6 80.6 0.96 December, 2011 E8230-396 Milk Sr-89 pCi/L 93.3 93.1 1.00 Sr-90 pCi/L 12.7 15.4 0.82 E8231-396 Milk 1-131 pCi/L 82.5 90.2 0.91 Cr-51 pCi/L 465 566 0.82 Cs-134 pCi/L 142 171 0.83 Cs-137 pCi/L 185 210 0.88 Co-58 pCi/L 177 221 0.80 Mn-54 pCi/L 208 241 0.86 Fe-59 pCi/L 164 183 0.90 Zn-65 pCi/L 259 291 0.89 Co-60 pCi/L 224 270 0.83 E8233-396 AP Cr-51 pCi 344 368 0.93 Cs-134 pCi 105 ill 0.95 Cs-137 pCi 129 137 0.94 Co-58 pCi 145 144 1.01 Mn-54 pCi 137 157 0.87 Fe-59 pCi 119 119 1.00 Zn-65 pCi 145 190 0.76 Co-60 pCi 168 176 0.95 December 2011 E8232-396 Charcoal 1-131 pCi 100 89.5 1.12 (a) Teledyne Brown Engineeringreportedresult.

(b) The Analytics known value is equal to 100% of the parameterpresent in the standard as determinedby gravimetric and/or volumetric measurements made during standardpreparation.

(c) Ratio of Teledyne Brown Engineering to Analytics results.

(d) Analytics evaluation based on TBE internalQC limits: A= Acceptable. Reported result falls within ratio limits of 0.80-1.20.

W-Acceptable with warning. Reported result falls within 0.70-0.80 or 1.20-1.30. N =Not Acceptable. Reported result falls outside the ratio limits of < 0. 70 and > 1.30.

B-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TELEDYNE BROWN ENGINEERING, INC. ENVIRONMENTAL LABORATORY 2011 ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM Identification Reported Known Month/Year Number Media Nuclide Units Value (a) Value (b) Control Limits Evaluation (c)

May 2011 RAD-85 Water Sr-89 pCi/L 59.8 63.2 51.1 -71.2 A Sr-90 pCi/L 42.5 42.5 31.3 -48.8 A Ba-133 pCi/L 73.3 75.3 63.0 - 82.8 A Cs-134 pCi/L 64.9 72.9 59.5 - 80.2 A Cs-137 pCi/L 74.6 77.0 69.3 - 87.4 A Co-60 pCi/L 87.8 88.8 79.9- 100 A Zn-65 pCi/L 103 98.9 89.0-118 A Gr-A pCi/L 64.1 50.1 26.1 -62.9 N (1)

Gr-B pCi/L 51.8 49.8 33.8-56.9 A 1-131 pCi/L 27.4 27.5 22.9 - 32.3 A U-Nat pCi/L 38.5 39.8 32.2 -44.4 A H-3 pCi/L 10057 10200 8870-11200 A MRAD-14 Filter Gr-A pCi/filter 79.7 74.3 38.5-112 A November 2011 RAD-87 Water Sr-89 pCi/L 81.0 69.7 56.9 - 77.9 N (2)

Sr-90 pCi/L 35.5 41.4 30.2 - 47.2 A Ba-1 33 pCi/L 90.7 96.9 81.8-106 A Cs-134 pCi/L 36.6 33.4 26.3- 36.7 A Cs-137 pCi/L 44.7 44.3 39.4-51.7 A Co-60 pCi/L 118.7 119 107- 133 A Zn-65 pCi/L 80.2 76.8 68.9 - 92.5 A Gr-A pCi/L 34.2 53.2 27.8 - 66.6 A Gr-B pCi/L 39.3 45.9 30.9 - 53.1 A 1-131 pCi/L 22.9 27.5 22.9 - 32.3 A U-Nat pCi/L 46.8 48.6 39.4 - 54.0 A H-3 pCi/L 15733 17400 15200 - 19100 A MRAD-15 Filter Gr-A pCi/filter 44.6 58.4 30.3 - 87.8 A March 2011 11-MaW24 Water Cs-134 Bq/L 19.1 21.5 15.1 -28.0 A Cs-137 Bq/L 29.0 29.4 20.6 - 38.2 A Co-57 Bq/L 0.139 (1) A Co-60 Bq/L 23.9 24.6 17.2 - 32.0 A H-3 Bq/L 265 243 170-316 A Mn-54 Bq/L 31.8 31.6 22.1 -41.1 A K-40 Bq/L 94.8 91 64- 118 A Sr-90 Bq/L 9.64 8.72 6.10- 11.34 A Zn-65 Bq/L -0.142 (1) A 11-GrW24 Water Gr-A Bq/L 0.767 1.136 0.341 -1.931 A Gr-B Bq/L 3.43 2.96 1.48 -4.44 A 11-MaS24 Soil Cs-134 Bq/kg 612 680 476-884 A Cs-137 Bq/kg 772 758 531 -985 A Co-57 Bq/kg 910 927 649- 1205 A Co-60 Bq/kg 500 482 337 - 627 A Mn-54 Bq/kg 0.607 (1) A K-40 Bq/kg 569 540 378 - 702 A Sr-90 Bq/kg NR 160 112 - 208 N (2)

Zn-65 Bq/kg 1497 1359 951 -1767 A (1) The solids on the planchet exceeded 100 mg, which was beyond the rangeof the efficiency curve. NCR 11-08 (2) Sr-89 TBE to known ratio of 1.16 fell within acceptablerange of +/- 20%. No action required. NCR 11-16 (a) Teledyne Brown Engineering reportedresult.

(b) The ERA known value is equal to 100% of the parameterpresent in the standard as determinedby gravimetric and/or volumetric measurements made during standardpreparation.

(c) ERA evaluation:A=acceptable. Reported result falls within the Warning Limits. NA=not acceptable. Reported result falls outside of the Control Limits. CE=checkfor Error. Reportedresult falls within the Control Limits and outside of the Warning Limit.

B-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2011 TELEDYNE BROWN ENGINEERING, INC. ENVIRONMENTAL LABORATORY 2011 ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM Identification Reported Known Acceptance Month/Year Number Media Nuclide Units Value (a) Value (b) Range Evaluation (c)

Mar-2011 11-RdF24 AP Cs-134 Bq/samph 3.26 3.49 2.44-4.54 A Cs-137 Bq/samph 2.36 2.28 1.60-2.96 A Co-57 Bq/samph 3.30 3.33 2.33-4.33 A Co-60 Bq/samph 0.0765 (1) A Mn-54 Bq/sampl 2.84 2.64 1.85-3.43 A Sr-90 Bq/sampli NR 1.36 0.95- 1.77 N (2)

Zn-65 Bq/sampl 3.30 3.18 2.23-4.13 A 11-GrF24 AP Gr-B Bq/sampli 1.23 1.323 0.662 - 1.985 A 11-RdV24 Vegetation Cs-134 Bq/samph 4.97 5.50 3.85-7.15 A Cs-137 Bq/samph 0.0356 (1) A Co-57 Bq/samph 10.8 9.94 6.96- 12.92 A Co-60 Bq/samph 4.89 4.91 3.44 - 6.38 A Mn-54 Bq/samph 6.42 6.40 4.48-8.32 A Sr-90 Bq/samph NR 2.46 1.72 - 3.20 N (2)

Zn-65 Bq/samph 3.07 2.99 2.09- 3.89 A September2011 11-MaW25 Water Cs-134 Bq/L 16.0 19.1 13.4-24.8 A Cs-137 Bq/L 0.0043 (1) A Co-57 Bq/L 33.1 36.6 25.6-47.6 A Co-60 Bq/L 26.9 29.3 20.5- 38.1 A H-3 Bq/L 1011 1014 710- 1318 A Mn-54 Bq/L 23.2 25.0 17.5-32.5 A K-40 Bq/L 147 156 109 - 203 A Sr-90 Bq/L 15.8 14.2 9.9-18.5 A Zn-65 Bq/L 27.3 28.5 20.0- 37.1 A September 2011 11-GrW25 Water Gr-B Bq/L 5.87 4.81 2.41 -7.22 A 11-MaS25 Soil Cs-134 Bq/kg -0.213 (1) A Cs-137 Bq/kg 1110 979 685- 1273 A Co-57 Bq/kg 1290 1180 826 - 1534 A Co-60 Bq/kg 731 644 451 - 837 A Mn-54 Bq/kg 987 848 594 - 1102 A K-40 Bq/kg 753 625 438-813 W Sr-90 Bq/kg 276 320 224-416 A Zn-65 Bq/kg 1870 1560 1092-2028 A September2011 11-RdF25 AP Cs-134 Bq/sampl -0.043 (1) A Cs-137 Bq/sampl 3.09 2.60 1.82-3.38 A Co-57 Bq/sampl 5.36 5.09 3.56 - 6.62 A Co-60 Bq/sampl 3.41 3.20 2.24-4.16 A Mn-54 Bq/samph 0.067 (1) A Sr-90 Bq/sampl 1.84 1.67 1.17-2.17 A Zn-65 Bq/sampl 5.17 4.11 2.88- 5.34 W 11-GrF25 AP Gr-B Bq/samph -0.01 (1) A 11-RdV25 Vegetation Cs-134 Bq/sampl 0.0081 (1) A Cs-137 Bq/samph 4.94 4.71 3.30 -6.12 A

Co-57 Bq/samph 0.0639 (1) A Co-60 Bq/samplh 3.36 3.38 2.37-4.39 A Mn-54 Bq/sampl 5.89 5.71 4.00- 7.42 A Sr-90 Bq/sampl 1.31 1.26 0.88- 1.64 A Zn-65 Bq/samplh 6.54 6.39 4.47- 8.31 A (I) False positive test.

(2) Evaluatedas failed due to not reporting a previously reportedanalyte. NCR 11-11 (3) The filter for Gross Alpha was counted on the wrong side. Recounted on the correct side resulted in acceptable results. NCR 1I- 11 (a) Teledyne Brown Engineeringreportedresult.

(b) The MAPEP known value is equal to 100% of the parameterpresent in the standardas determined by gravimetric and/or volumetric measurements made during standardpreparation.

(c) DOEOMAPEP evaluation:A=acceptable, W=acceptable with warning,N=not acceptable.

B-6