Text

Annual Radiological Environmental Operating Report for 2015
	ML16153A300
Person / Time
Site:	Millstone
Issue date:	04/28/2016
From:	Stanley B; Dominion Nuclear Connecticut
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	Download: ML16153A300 (88)
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{{#Wiki_filter:Dominion Nuclear Connecticut, Inc. Rope Ferry Rd., Waterford, CT 06385 Mailing Address: P.O. Box 128 Waterford, CT 06385 dam.com APR 2 8 2016 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 DOMINION NUCLEAR CONNECTICUT, INC. MILLSTONE POWER STATION UNITS 1, 2, AND 3 Serial No. MPS Lic/AVM Docket Nos. License Nos. 2015 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT 16-166 RO 50-245 50-336 50-423 DPR-21 DPR-65 NPF-49 This letter transmits the Annual Radiological Environmental Operating Report for the Millstone Power Station, for the period January 2015 through December 2015. This satisfies the provisions of Section 5.7.2 of Millstone Power Station Unit 1 Permanently Defueled Technical Specifications (POTS), 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. Mr. Thomas G. Cleary at (860) 444-4377. Sincerely, ws-+/-;; Brandford L. Stanley Director, Nuclear Station Safety and Licensing

Attachments: 1 Commitments made in this letter:

1. None.

cc: U. S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 S. J. Giebel NRC Project Manager Millstone Unit 1 U.S. Nuclear Regulatory Commission Two White Flint Nort,h, Mail Stop T-8 F5 11545 Rockville Pike Rockville, MD 20852-2738 L. A. Kauffman NRC Inspector U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 H. W Anagnostopoulos NRC Inspector U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 R. V. Guzman Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 2of4 NRC Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission -- One White Flint North, Mail Stop 08 C2 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

(2copies) Director Bureau of Air Management Monitoring & Radiation Division Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 3of4 Department of Energy and Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Regional Radiation Representative (EPA Region 1, Boston) U. S. Environmental Protection Agency (Region 1) 5 Post Office Square Suite 100 Boston, MA 02109 Regional Representative 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 Chairman Waterford-East Lyme Shellfish Commission Waterford Town Hall Waterford, CT 06385 S. Brietmaier American Nuclear Insurers 95 Glastonbury Blvd. Glastonbury, CT 06033 D. Carey Connecticut Department of Agriculture Aquaculture Division P. 0. Box 97 Millford, CT 06460

D. Steward First Selectman Town of Waterford Waterford Town Hall Waterford, CT 06385 M. C. Nickerson First Selectman Town of East Lyme PO Box 519 Niantic, CT 06357 University Of Connecticut Library Serials Department Storrs, CT 06268 Mrs. John Mingo 69 Spithead Road Waterford, CT 06385 Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 4 of 4

ATTACHMENT 1 Serial No. 16-166 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 2015 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT MILLSTONE POWER STATION UNITS 1, 2, AND 3 DOMINION NUCLEAR CONNECTICUT, INC. (DNC)

Millstone Power Station 2015 Radiological Environmental Operating Report January 1, 2015 - December 31, 2015 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 2015 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. Millstone Power Station Annual Radiological Environmental Operating Report 2015 ,...., TABLE OF CONTENTS,...., EXECUTIVE

SUMMARY

.................................................................................................. i

1.

INTRODUCTION........................................................................................ 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 Operations............................................................. 1-3 1.5 Radioactive Effluent Control............................................................. 1-8 1.6 Radiological Impact on Humans.............................. :...................... 1-10

2.

PROGRAM DESCRIPTION........................................................................... 2.1 2.1 Sampling Schedule And Locations................................................... 2.1 2.2 Samples Collected During Report Period......................................... 2-7 2.3 Required Samples Not Collected During the Report Period........... 2-8

3.

RADIOCHEMICAL RESUL TS........................................................................ 3-1 3.1 Summary Table................................................................................ 3-1 3.2 Data Tables....................................................................................... 3-5

4.

DISCUSSION OF RESULTS..........................................................................4-1 4.1 Gamma Exposure Rate (Table 1)....................................................4-1 4.2 Air Particulate Gross Beta Radioactivity (Table 2)...........................4-4 4.3 Air Iodine (Table 3)...............................................................4-5 4.4 Air Particulate Gamma (Table 4)...................................................... 4-5 4.5 Soil (Table 5)........................................ *........................................... 4-5 4.6 Cow Milk (Table 6)........................................................................... 4-6 4.7 Well Water (Table 7)........................................................................ 4-6 4.8 Fruits and Vegetables (Table 8)........................ ~......................,.......4-6 4.'9 Broad Leaf Vegetation (Table 9)................................................ :......4-6 4.10 Seawater (Table 10)........................................................................4-7 4.11 Bottom Sediment (Table 11 )................,........................................... 4-8 4.12 Aquatic Flora (Table 12)................................. ~................................ 4-8 4.13 Fish (Tables 13)............................................................................... 4-8 4.14 Oysters (Table 14)........................................................................... 4-9 4.15 Clams (Table 15)............................................................................... 4-9 4.16 Lobsters (Table 16).........................................................................4-9

5.

REFERENCES............................................................................ 5-1 APPENDIX A - LAND USE CENSUS FOR 2015................................................. A-1 APPENDIX B -

SUMMARY

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

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015

Dominion Nuclear Connecticut, Inc. Millstone Power Station INTRODUCTION Annual Radiological Environmental Operating Report 2015 EXECUTIVE

SUMMARY

This report summarizes the results of the Radiological Environmental Monitoring Program (REMP) conducted in the vicinity of the Millstone Nuclear Power Station (Millstone) during the period from January 1 to December 31, 2015. This document has been prepared in accordance with the requirements of the separate Technical Specifications for Millstone Units 1, 2 and 3. The REMP has been established to monitor the radiation and radioactivity released to the environment as a result of Millstone's operation. This program, initiated in April 1967, includes the collection, analysis, and evaiuation of radiological data in order to assess* the impact of Millstone on the environment and on the general public. SAMPLING AND ANALYSIS The environmental sampling media collected in the vicinity of Millstone and at distant locations included terrestrial samples in the form of air particulate filters, charcoal cartridges, soil, cow milk, well water, broadleaf vegetation, fruits and vegetables; and aquatic samples.in the form of seawater, bottom sediment, aquatic flora, fish, oysters, clams and lobster. During 2015, there were 721 samples collected from the atmospheric, aquatic, and terrestrial environments. In addition, 176 exposure measurements were obtained using environmental thermoluminescent dosimeters (TLDs). A discussion of all discrepancies from the sample collection requirements in the Millstone Radiological Effluent Monitoring and Offsite Dose Calculation Manual (REMO DCM) is given in Section 2.3 of this report. Teledyne Brown Engineering, Inc. of Knoxville, Tennessee performed the sample analyses and Environmental Dosimetry Company of Sterling, Massachusetts performed the TLD analyses. LAND USE CENSUS The annual land use census in the vicinity of Millstone was conducted as required by the Millstone REMO DCM. 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 2015 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. However, for dose calculation, garden distances are based on nearest resident assuming that a resident may plant a new garden. This gives a more conservative dose result. Goat locations are more difficult to determine, but best efforts are made by reviewing membership list of the American Dairy Goat Association records, contacting previous owners and, if necessary, performing visual drive-by inspections. RADIOLOGICAL IMPACT TO THE ENVIRONMENT The radioactivity detected in some samples was from non-station related sources, such as fallout from past nuclear weapons tests and naturally occurring radionuclides. All terrestrial samples collected as part of the Millstone REMP did not show any station related radioactivity.

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Monitoring of seawater in the area of the discharge indicated the presence of tritium, a station related radionuclide. Tritium was only found in seawater onsite jnside the mixing zone of the quarry discharge at levels that were expected from routine station operation. Offsite ambient radiation measurements using environmental TLDs beyond the site boundary ranged between 45 and 95 milliRoentgens per year. The range of ambient radiation levels observed with the TLDs is consistent with natural background radiation levels for Connecticut. RADIOLOGICAL IMPACT TO THE GENERAL PUBLIC During 2015, radiation doses to the general public as a result of Millstone'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 (whole body) dose to the maximally exposed member of the general public from radioactive effluents and ambient radiation resulting from Millstone operations for 2015 was approximately 0.25 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. CONCLUSIONS The 2015 REMP for Millstone resulted in the collection and analysis of 897 environmental samples and measurements. The data obtained were used to determine the impact of Millstone's operation oil 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 Millstone's operation.

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 acronym 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 acronym for radiation absorbed dose. One rad is equal to the absorption of 100 ergs of energy per gram of tissue. ii

Dominion Nuclear Connecticut, Inc. Millstone Power Station

1.

INTRODUCTION Annual Radiological Environmental Operating Report 2015 This section provides an overview of the Millstone 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 2015 performed by Dominion Nuclear Connecticut (DNC) for Millstone is discussed in this report. Since the operation of a nuclear power station results in the release of small amounts of radioactivity and low levels of radiation, the Nuclear Regulatory Commission (NRC) requires by regulations and technical specifications that a program be established to monitor radiation and radioactivity in the environment (References 1, 6, 9, 10 & 11). This report, published annually per Millstone's Technical Specifications (section 5.7.2 for Millstqne Unit 1, section 6.9.1.6A for Millstone Unit 2 and Section 6.9.1.3 for Millstone Unit 3), summarizes the,results of measurements of radiation and radioactivity in the environment in the vicinity of Millstone and at distant locations during the period January 1 to December 31,2015. 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 milk, well water, broadleaf vegetation, fruits, vegetables, seawater, bottom sediment, aquatic flora, fish, 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 Millstone operation and other natural and man-made sources. These results are reviewed by Millstone'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 station 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 Millstone. 1.2 Radiation and Radioactivity All matter is made of atoms. Nuclear radiation is energy or particles that are 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 fallout from nuclear weapons testing. Examples of radioactive fallout that could be present in environmental samples are cesium-137 and strontium-90. Some examples of radioactive materials released from a nuclear power station are hydrogen-3 (tritium), cesium-137, iodine-131, strontium-90, and cobalt-60. 1-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 acronym 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 acronym 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 & 5). The per capita dose has increased since the early 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 one-trillionth of a Curie and 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 Corresponding Approximate Doses (1) NATURAL Radiation Dose Source (mrem/vear) Internal, inhalation<2l 228 External, space 33 Internal, ingestion 29 External, terrestrial 21 Approximate Total 311 {1) information from References 3 and 4 (2) from radon and thoron MAN-MADE Radiation Dose Source (mrem/year) Medica1(3l 300 Consumer(4l 13 Industrial, security, 0.3 educational, research Occupational 0.5 Weapons Fallout < 1 Nuclear Power Stations < 1 Approximate Total 314 (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) 1-2

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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-? and carbon-14 are formed in this way. Exposure to cosmic and cosmogenic sources of radioactivity results in about 33 mrem of radiation dose per year. Additionally, natural radioactivity is in our body and. in the food we eat (about 29 mrem/year), the ground we walk on (about 21 mrem/year) and the air we breathe (about 228 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 311 mrem per year. In addition to natural 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 as cigarettes, building materials and commercial air travel contribute about 13 mrem/year. Much smaller doses result from weapons fallout (less than 1 mrem/year) and nuclear power stations (less than 1 mrem/year). Typically, the average person in the United States receives approximately 314 mrem per year from man-made sources. 1.4 Nuclear Reactor Operations Millstone generates about 2100 megawatts of electricity at full power, which provides approximately one-third of the power consumed in the State of Connecticut. Millstone Unit 2 and Millstone Unit 3 are pressurized water reactors (Millstone Unit 1, 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, Connecticut. Commercial operation of Millstone Unit 2 began in December 1975 and Millstone Unit 3 in May 1986. Millstone was operational during most of 2015, with the exception of a refueling outage at Millstone Unit 2 in October. The annual capacity factor for Millstone Unit 2 was 88.7% and for Millstone Unit 3 was 100.5%. 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 (see Figure 1.4-1 ). The cooling water source for Millstone is the Niantic Bay. 1-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 The key difference between nuclear power and conventional power is the source of heat used to boil the water. Conventional stations burn fossil fuels in a boiler, while nuclear stations 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, 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). SIMPLIFIED DIAGRAM OF A PRESSURIZED WATER REACTOR Pressuri:z:ed water reactor-a common type of Light Water Reactor Figure 1.4-1 1-4 (LWR)

~----------.....,*coNOENSER COO UNG WATER

-.;;...;,;;;,,;;,;,,;;;;,;;i;iiii0ii __ ,TA.KiNC WASTE HEAT TOTHE ENViRONMEN't

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 (see Figure 1.4-2). Neutron *

Uranium Fission Products Figure 1.4-2 Uranium

~ WlllJJ Uranium Radioactive Fission Product Formation 1-5 1.,....... Neutrons Fission Products

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Radioactive activation products (see Figure 1.4-3), 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). 0

col.ii~icm
with stable

co6alt Nucleus Figure 1.4-3

- ~

Radioactive Activation Product Formation Co-60 Radioactive.

cci*balt::Ntic1eus At Millstone there are five independent protective barriers that confine these radioactive materials. These five barriers are:

fuel pellets; fuel cladding; reactor vessel and associated piping and equipment; primary containment and, secondary containment (enclosure building). 1-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Entjronmental Operating Report 2015 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. Radioactivity can also escape into coolant water through cladding defects and failures. 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. During operation the containment is closed but small amounts of radioactivity may be released from primary containment by venting during operation to maintain proper containment pressure. During maintenance and refueling outages containment is open and small amounts of radioactivity is released during this time when the fuel has been moved out of the reactor cavity in containment. 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 Millstone'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 mech~nical 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. The control of radioactive effluents at Millstone will be discussed in more detail in the next section. 1-7

Dominion Nuclear Connecticut, Inc. Millstone Power Station 1.5 Radioactive Effluent Control Annual Radiological Environmental Operating Report 2015 The small amounts of radioactive liquids arid gases that might escape the first two barriers are processed in the liquid and gaseous 1 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 radioactivity in liquids discharged into Niantic Bay. Wastes processed through liquid radwaste treatment can be purified and, in some cases, re-used in station systems. Prior to release, the radioactivity in any 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 will 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 environment 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 environment. 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. 1-8

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 The preceding discussion illustrates that many controls exist to reduce the radioactive liquid effluents released to the environment 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 Millstone Unit 3) ventilation system; Millstone station stack and units' vent effluent radioactivity monitors; sampling and analysis of Millstone station stack and units' 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 station process computer aids in tracking the monitor readings. To supplement the information continuously provided by the detector, air samples are taken periodically from the units' containments, Millstone station stack and units' vents. These samples are analyzed to quantify the total amount of radioactive gases, radioactive iodines, radioactive particulate and tritium released in gaseous effluents. Gases from the primary coolant are held up in waste gas decay tanks for decay at Millstone Unit 2. Gaseous waste at Millstone Unit 3 is purified through a process gas system, consisting of high-efficiency particulate air filters and charcoal adsorber beds. Gases from periodic venting of the Millstone Unit 2 containment are released through a similar process system (Enclosure Building Filtration System) while gases from the Millstone Unit 3 containment vacuum pumps are released without treatment. If necessary, Millstone Unit 3 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 Millstone Unit 2 are filtered by high-efficiency particulate filters while at Millstone Unit 3 these are not normally filtered. If necessary, particulate and charcoal filters can be used for these purges. Normally, for Unit 2, the air released from the unit vent is from the ventilation of the auxiliary (which includes the fuel pool), service and enclosure buildings. For Unit 2, fuel pool and enclosure building ventilation can be redirected to the Millstone Site Stack. Normally, for Unit 3, the air released from the unit vent is from the ventilation of the auxiliary, fuel, service, waste disposal and enclosure buildings. For Unit 3, enclosure building ventilation can be redirected to the Millstone Site Stack. 1-9

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 are closed to stop the release and ensure that federal regulatory limits are always met. 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. 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 calculation of the dose impact to the general public from Millstone's radioactive effluents. The purpose of this calculation is to periodically assess the dose to the general public resulting from radioactive effluents to ensure that the dose is being maintained as far below the federal dose limit 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 Millstone during each 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. The liquid and gaseous effluents were well below the federal release limits and were a small percentage of the Millstone REMO DCM 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, 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 Millstone to its effect on man. The movement of radioactivity through the environment and its transport to humans is portrayed in Figure 1.6. 1-10

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 EXAMPLES OF Millstone's RADIATION EXPOSURE PATHWAYS LIQUID EFFLUENTS

1. SHORELINE DIRECT RADIATION (FISHING, PICNICJNG) ~

2. DIRECT RADIATION (IMMERSION IN OCEAN, BOATING, SWIMMING)

INGESTION

3. CONSUMPTION (FISH, SHELLFISH)

3. DIRECT RADIATION (STATIO~ 2. AIR INHALATION ef /V"" /

1. DIRECT RADIATION

. *e LY e;sMERs10NJ ~ 4.- Figure 1.6

5. CONSUMPTION (VEGETATION) t DEPOSITION

(/ &B:m; ~ DEPOSITION Radiation Exposure Pathways 1-11

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 There are four pathways in which liquid effluents affect humans: external radiation from liquid effluents that deposit and accumulate on the shoreline; external radiation during boating from radioactivity in ocean water; external radiation from immersion in ocean water containing radioactivity; and, internal radiation from consumption of fish and shellfish containing radioactivity absorbed from the liquid effluents. There are five major ways in which gaseous effluents affect humans: external radiation from immersion in an airborne plume of radioactivity; internal radiation from inhalation of airborne radioactivity; external radiation from deposition of radioactive effluents on the ground; 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. Ambient (direct) radiation emitted from sources of radioactivity at Millstone comes 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 a small amount 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. However, the operation of Millstone 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 NRG-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 specified in the Millstone'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. 1-12

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 After dose calculations are performed, the results are compared to the dose limits for the public as specified in NRC':s technical specifications for Millstone (References 9-11 ). The technical specifications limits for the dose to a member of the general public from radioactive material in liquid effluents released to unrestricted areas are: 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 technical specifications limits for dose due to release of radioactivity in gaseous effluents is restricted to: less than or equal to 10 mrad per year for gamma radiation from noble gases, less than or equal to 20 mrad per year for beta radiation from noble gases and less than or equal to 15 mrem per year to any organ from iodine-131, iodine-133, tritium, and all particulate radionuclides with half-lives greater than 8 days. The technical specifications limits for total dose from all three Millstone units due to release of radioactivity in gaseous and liquid effluents and direct radiation is restricted 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. 1-13

Dominion Nuclear Connecticut, Inc. Millstone Power Station

2. PROGRAM DESCRIPTION 2.1 Sampling Schedule and Locations Annual Radiological Environmental Operating Report 2015 The sample locations and the sample types and frequency of analysis are given in Tables 2-1 and 2-2 and shown in Figures 2.1 and 2.2. The program as described on Table 2-2 only lists the required samples as specified in the REMO DCM. However, in order to identify the locations of the extra samples, all locations (both required and extra) are listed in Table 2-1.

2-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table 2-1 Environmental Monitoring Program Sampling Types and Locations

.:;::.;::::::;:,:c::;: Onsite - Old Millstone Rd.

Onsite - Weather Shack Onsite - Bird Sanctuary Onsite - Albacore Drive Onsite - MP3 Discharge Onsite - Quarry Discharge Onsite - Env. Lab Dock Onsite-Env. Lab Onsite - Bay Point Beach ..,.. *.:***'"*****""' Pleasure Beach Great Neck Country Club Fisher's Island, NY Mystic, CT Ledyard, CT Norwich, CT Old Lyme, CT Site Boundary Cow Within 10 Miles Within 10 Miles Beyond 10 Miles .......... ~"*"""*** Beyond 10 Miles Niantic Two Tree Island West Jordan Cove West Jordan Cove '*'"'""*"'***.<**>.*'"** Niantic Shoals Vicinity of Discharge Vicinity of Discharge Seaside Point Niantic Bay Niantic Bay Black Point ,.,;.;;:,;,,;;;:*>:":.:*, Giant's Neck Waterford Shellfish Bed #1 Myrock Avenue Billow Road Black Point Onsite - Schoolhouse Onsite - Access Road .........,..........,."'". Old Lyme - Hillcrest Ave. East L me - W. Main St. 0.6 Mi, NNW 0.3 Mi, S 0.3 Mi, NE 1.0 Mi, N 0.1 Mi, SSE 0.3 Mi, SSE 0.3 Mi, SE 0.3 Mi, SE 0.4 Mi, W 1.2 Mi, E 1.6 Mi, ENE 8.0 Mi, ESE 11.5 Mi, ENE 12.0 Mi, NE 14.0 Mi, N 8.8Mi,W 0.5 Mi, NE 10.5 Mi, WNW < 10 Miles < 10 Miles > 10 Miles > 10 Miles 1.?Mi, WNW 0.8Mi, SSE 0.4 Mi, ENE-ESE 0.4 Mi, NNE 1.8 Mi, NW < 0.1 Mi < 0.1 Mi 1.8 Mi, ESE <0.5 Mi, SSW-W 0.3 Mi, WNW 3.0Mi,WSW 3.5 Mi, WSW 1.0 Ml, NW 3.2 Mi, ENE 2.4 Mi, WSW 2.6 Mi, SW 0.1 Mi, NNE 0.5 Mi, NNW 4.6Mi,WSW 4.5Mi,W 2-2 TLD, Air Particulate, Iodine, Vegetation TLD, Air Particulate, Iodine TLD, Air Particulate, Iodine, Soil TLD, Air Particulate, Iodine, Soil TLD TLD TLD TLD TLD TLD, Air Particulate, Iodine, Vegetation TLD, Air Particulate, Iodine TLD TLD TLD, Soil TLD, Air Particulate, Iodine TLD Vegetation Milk Vegetation Fruits and/or Vegetables3 Vegetation Fruits and/or Vegetables3 TLD, Air Particulate, Iodine Fish 4 Clams, Fish4 Fucus Bottom Sediment, Oysters Bottom Sediment, Oysters, Fish4, Seawater Fucus Bottom Sediment Lobster, Fish4 Fucus Fucus Bottom Sediment, Oysters, Seawater Clams TLD TLD TLD TLD TLD TLD TLD

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 .:~3~~~::::.:1£~:~~(1'~~~~;~~,ffi~;~*;i":"~~.>;:~1::;:i:*;~-;;ti1([!;:*~;,~[.).~:/ij~i~~~1~~:6}cg:~~:ir:s~~:;~~~->,1~~N~:~<~~~*Jr~~lt:;*~~~*i*:;.. ~;:C:~/:,:i~r '~i~ East Lyme - Corey Rd. 3.4 Mi, WNW TLD East Lyme - Society Rd. 3.6 Mi, NW TLD East Lyme - Manwaring Rd. 2.. 1 Mi,W TLD East Lyme - Smith Ave. 1.5 Mi, NW TLD Waterford - River Rd. 1.1 Mi, NNW TLD Waterford - Gardiners Wood Rd 1.4 Mi, NNE TLD Waterford - Magonk Point 1.8 Mi, ESE TLD New London - Mott Ave. 3.7 Mi, E TLD New London - Ocean Ave. 3.6Mi, ENE TLD Waterford -Miner Ave. 3.4 Mi, NNE TLD Waterford - Parkway South 4.0 Mi, N TLD Waterford - Boston Post Rd. 4.3 Mi, NNW TLD East Lyme - Columbus Ave. 1.9 Mi, WNW TLD Waterford - Jordon Cove Rd. 0.8 Mi, NE TLD Waterford - Shore Rd. 1.1 Mi, ENE TLD Waterford - Bank St. 3.2 Mi, NE TLD NAP Parking Lot - Fit Center 0.4 Mi, NW TLD 1-MW-XFMR-03 5 Onsite Well Water MW-GPl-1 5 Onsite Well Water Site Switchyard Fence 0.3 Mi, N TLD Ball Field Foul Pole 0.6 Mi, N TLD Waterford -Windward Way & 0.5 Mi, NE TLD Shotgun ISFSl-1 Up-gradient of ISFSI Well Water ISFSl-2 Down-gradient of ISFSI Well Water ISFSl-3 Down-gradient of ISFSI Well Water M3-MW-1 5 Onsite Well Water S2-MW-1 5 On site Well Water MW-6B 5 On site Well Water S3-MW-2 5 Onsite Well Water DEEP Dock 0.2 Mi, WNW Oysters Aquatic background >4 Mi of discharge Lobster Thames River 4Mi, E Fucus Footnotes:

1. Key:

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

2. Release points are the Millstone station stack for terrestrial locations and the quarry cut for aquatic locations.

3. A fruit or vegetable sample may count as a required vegetation sample.

4. Fish required to be sampled at Location #35 and from one of three other locations (#28, #29 or #32).

5. Any onsite well may be substituted.

2-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table 2-2 Required Sampling Frequency & Type of Analysis

>(:*.

- E?(pq*s.ii_i"~.Pa~fiway*:** * *.::.J:Jo,)'?f **.

>S~roi:>lil'l~f &.G911~C;:tioh Fr~<1u.ei:i¢Y. *

-.:~.

. *ti'P,~.~~t~~~'.Y~.i~

T-~:*i:!;l.

.:/::>:: >.:a;~~,i~i*8~wil_1~ :: f. '" L.~c:a!i~~s. : *:**: * *:*::*-..* :.. _.:::.*:.~***.:r;:=:r*!*\\:_.::_:*.**:-~ ***=.*:*.*,._*::*::' ::*;. c: :**. *:,.:* }:( />. ::*:*"<.<**;: :./

1.

Gamma Dose-391 Quarterly Gamma Dose - Quarterly Environmental TLD

2.

Airborne Particulate 8 Continuous sampler - filter change Gross Beta - Every two weeks every two weeks 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 - canister 1-131 - Every two weeks change every two weeks

4.

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

5.

Sea Water 2 Continuous sampler with a monthly Gamma Isotopic and Tritium on collection at indicator location. each sample. Quarterly at control location - Composite of 6 weekly grab samples.

6.

Well Water 6 Semiannual Gamma Isotopic and Tritium on each sample

7.

Bottom Sediment 5 Semiannual Gamma Isotopic on each sample

8.

Soil 3 Annually Gamma Isotopic on each sample

9.

Fin Fish 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) Footnotes

1. Two or more TLDs or TLD with two or more elements per location.

2-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Figure 2.1, "Inner TLD, Air, Grass, Soil, and Aquatic Locations" 2-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 2-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 2.2 Samples Collected During Report Period The following table summarizes the number of samples of each type collected and analyzed during 2015: Gamma Exposure 156 156 20 (Environmental TLD} Air Particulates 208 208 0 Air Iodine 208 208 0 Soil 3 3 0 Cow Milk 0 0 18 Well Water 12 12 15 Fruits & Vegetables 4 4 5 Broadleaf vegetation 8 8 0 Sea Water 16 16 0 Bottom Sediment 10 10 0 Aquatic Flora 0 0 20 Fish 8 ?1 0 Oysters 16 16 0 Clams 8 71 0 Lobster 8 8 0 Total All Types 665 663 78 1 Due to sample unavailability, not all required fish and clam samples could be obtained. 2-7

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 2.3 Required Samples Not Collected During the Report Period During 2015 there were two required samples not collected - one fish and one clam sample. Also, one oyster sample was collected late with less than a full sample period of collection. During the first quarter of 2015 repeated attempts to collect fish in Niantic Bay and clams in Waterford Shellfish Bed were unsuccessful. The fourth quarter oyster sample at Giant's Neck (Location #37), the control location, was collected late on January 15, 2016. Oysters are stocked in trays and the trays are placed at sampling areas for 30 to 50 days before sample collection. At the normal sample date in mid-December it was discovered that the oysters at Giant's Neck had been stolen. The oysters were replaced and they remained in location for the procedurally required minimum of 30 days. Thus, the 4th quarter sample result actually represents a sample period of the end of December and the beginning of January. \\

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015

3.

RADIOCHEMICAL RES UL TS 3.1 Summar¥ Table In accordance with the REMODCM, Section l.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. 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 replace samples from required locations when they are.not available. Medium or Pathway Sampled (Units) Direct Radiation TLD (uR!hr) Air Iodine (pCi!m 3 ) Air Particulate (pCilm 3 } Soil (pCi/g dry) Milk (pCill) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Indicator Analysis Total LLD Locations Location with HiQhest Mean Type Number Note 1 Mean Number I Distance I Mean (Range\\ Direction (Range) Gamma 176 NA 7.6 8 0.3Mi. 10.8 Dose (4.4-11.9) SE (9.6-11:6) 1-131 208 0.07 <LLD NA NA <LLD GR-B 208 0.01 0.0137 0.6Mi. 0.0145 (0.0042 - 0.023) NNW (0.0069 - 0.0226) GAMMA 32 BE-7 NA 0.0142 2 0.3Mi. 0.281 (0.084 - 0.820) s (0.096 - 0.820) Other Note2 <LLD NA NA <LLD Gammas GAMMA 3 K-40 NA 14.0 4 1.0Mi. 15.1 (13.1 -15.1) N One sample CS-137 0.18 0.34 4 1.0Mi. 0.52 (0.17 - 0.52) N One sample Other Note3 <LLD NA NA <LLD Gammas SR-89 4 10 <LLD NA NA <LLD SR-90 4 2 <LLD NA NA <LLD, GAMMA 18 K-40 NA 1261 22 10.3Mi. 1261 (1102-1379) WNW (1102 - 1379) Other Note4 <LLD NA NA <LLD Gammas 3-1 Control Locations Mean (Range) 7.5 (5.9-9.4) <LLD 0.0139 (0.0067 - 0.021) 0.117 (0.072 - 0.143) <LLD 13.8 One sample 0.34 One sample <LLD NA NA NA NA

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Medium or Pathway Sampled llUnitsl Well Water (pCi//) Fruits & Vegetables (pCilgwet) Broad Leaf Vegetation (pCi!g wet) Sea Water (pCil/) Bottom Sediment (pCi/g dry} Aquatic Flora - Note 13 (pCi!g wet) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Indicator Analysis Total LLD Locations Location with Highest Mean Type Numbe1 Note1 Mean Number I Distance I Mean (Ranael Direction (Ranael H-3 27 2000 <LLD NA NA <LLD GAMMA 27 K-40 NA 103-Note 5 78 Down-gradient 127 (91 -127) of ISFSI One sample Other Note6 <LLD NA NA <LLD Gammas GAMMA 9 K-40 NA 1.629 26 Beyond 1 O miles 1.747 (0.809 - 2.069) (0.803-3.199) Other Note? <LLD NA NA <LLD Gammas GAMMA 8 BE-7 NA 0.719 0.6Mi. 0.884 (0.485 - 0.959) NNW (0.808 - 0.959) K-40 NA 4.275 10 1.2 Mi. 5.596 (2.840 - 7.607) E (3.584 - 7.607) Other Note9 <LLD NA NA <LLD Gammas H-3 16 NA 530 - Note 10 32 On site 530 - Note 10 (205-1190) (205-1190) GAMMA 16 K-40 NA 317-Note11 32 Onsite 317-Note11 (238 -448) (238 -448) Other Note6 <LLD NA NA <LLD Gammas GAMMA 10 K-40 NA 15.5 34 4.0Mi. 17.08 (13.06 -19.94) ENE 14.22-19.94 Ac-228 NA 1.25-Note 12 31 1.8Mi. 1.24 (0.61 -2.16) NW (0.31 -2.16) Other Note3 <LLD NA NA <LLD Gammas GAMMA 20 BE-7 NA 0.203 - Note 14 29 <0.5Mi. 0.267 - Note15 (0.139 - 0.267) ENE to ESE (0.197 - 0.267) K-40 NA 6.98 32 On site 7.82 (6.02 - 9.45) (6.30 - 9.45) Ac-228 NA 0.113 - Note 16 29 <0.5 Mi. 0.123 - Note 17 (0.072 - 0.142) ENE to ESE (0.098 - 0.142) Other Note? <LLD NA NA <LLD Gammas 3-2 Control Locations Mean (Ranae) NA NA NA 1.747 (0.803 - 3.199) <LLD 1.032-Note 8 (1.021 -1.42) 3.533 (3.261 - 3.805) <LLD <LLD 282 (203-370) <LLD 15.25 (12.45 - 18.05) <LLD <LLD <LLD 6.60 (6.02 -7.11) 0.090 - Note 18 <LLD

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Medium or Pathway Sampled (Units) Fish (pCi/gwet) Oysters (pCi!g wet) Clams (pCi!g wet) Lobster (pCi/g wet) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Indicator Analysis Total LLD Locations Location with Highest Mean Type Number Note 1 Mean Number I Distance I Mean (Range) Direction (Range) GAMMA 7 K-40 NA 4.41 32 <0.5Mi. 5.16 (3.78-5.31) (5.00 - 5.31) other Note 19 <LLD NA NA <LLD Gammas GAMMA 16 K-40 NA 2.18 31 1.8 Mi. 2.33 (1.54 -2.78) NW (2.23 - 2.52) Other Note 19 <LLD NA NA <LLD Gammas GAMMA 7 K-40 NA 2.22 29 <0.5Mi. 2.30 (1.77 -2.78) ENE to ESE (1.77 - 2.78) Other Nole 19 <LLD NA NA <LLD Gammas GAMMA 8 K-40 NA 2.83 35 <0.5Mi. 2.83 (2.36 - 3.12) SSWtoW (2.36 - 3.12) other Note 19 <LLD NA NA <LLD Gammas NOTES FOR

SUMMARY

TABLE Control Locations Mean (Rangel NA NA 2.34 (2.20 - 2.58) <LLD NA NA 2.92 (2.54 - 2.69) NA 1 - The required LLD. LLD is the smallest concentration *of radioactivity that will be detected with 95% confidence that the activity is real. See detailed discussion below. 2 - LLDs for air particulate other gamma are 0.05 pCi/M3 for Cs-134 and 0.06 pCi/M3 for Cs-137. 3 - LLD for soil and sediment other gamma is 0.15 pCi/g for Cs-134. 4 - LLDs for milk other gamma are 1 pCi/I for 1-131, 15 pCi/I for Cs-134, 18 pCi/I for Cs-137, 70 pCi/I for Ba-140 and 25 pCi/I for La-140. 5 - Mean and range for three well sample results with positive K-40. All other sample results were less than LLD. 6 - LLDs for water other gamma are 15 pCi/I for Mn-54, Co-58, Co-60, Nb-95, 1-131, Cs-134 and La-140; 30 pCi/I for Fe-59, Zn-65 and Zr-95; 18 pCi/I for Cs-137 and 60 pCi/I for Ba-140. 7 - LLDs for fruits & vegetables, broadleaf vegetation and aquatic flora for other gamma are 0.06 pCi/M3 for 1-131, 0.06 pCi/M3 for Cs-134 and 0.08 pCi/M3 for Cs-137. 8 - Mean and range for two vegetation sample results with positive Be-7. Other two sample results were less than LLD. 9 - LLDs for other gamma are 0.06 pCi/g for Cs-134 and 1-131. 10 - Mean and range for nine seawater sample results with positive H-3. Other seven sample results were less than LLD. 11 - Mean and range for eleven seawater sample results with positive K-40. Other five sample results were less than LLD. 3-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station NOTES FOR

SUMMARY

TABLE (Continued} Annual Radiological Environmental Operating Report 2015 12.J Mean and range for four sediment sample results with positive Ac-228. Other six sample results were less than LLD. 13 - All aquatic flora locations are extra, non-required samples with Locations 29, 32 and 35 treated as indicators and Location 36 as a control. Location 90 is a special location which is downstream from the New London water treatment plant. Although it is not influenced by any Millstone releases, at times it will detect radioactivity released from the water treatment plant. Results from Location 90 are in Table 16 but not included here. 14 - Mean and range for six aquatic flora sample results with positive Be-7. Other ten sample results were less than LLD. 15 - Mean and range for two aquatic flora sample results with positive Be-7. Other two sample results . were less than LLD. 16 - Mean and range for six aquatic flora sample results with positive Ac-228. other six sample results were less than LLD. 17 - Mean and range for three aquatic flora sample results with positive Ac-228. One other sample result was less than LLD. 18 - Value for one aquatic flora sample result with positive Ac-228. Other three sample results were less than LLD. 19 - LLDs for fish and shellfish for gammas are 0.13 pCi/g for Mn-54, Co-58, Co-60 ana Cs-134; 0.26 pCi/g for Fe-59 and Zn-65; and 0.15 pCi/g for Cs-137. Discussion of LLD 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 (-AL~.t)

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) is the radioactive decay constant for the particular radionuclide A.t 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 were 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. 3-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station 3.2 Data Tables Annual Radiological Environmental Operating Report 2015 The data reported in this section are results of analyes on all samples. Positive results are shown as bolded type. Results are considered positive when the measured value exceeds 1.5 times the listed 2cr error (i.e., the measured value exceeds 3cr). The reported error is two times the _standard deviation (2cr) 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. 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). Data are given according to sample type as indicated below.

1. Gamma Exposure Rate

2. Air Particulates, Gross Beta Radioactivity

3. Air Particulates, Airborne 1-131

4. Air Particulates, Gamma Spectra

5. Soil

6. Milk

7. WellWater

8. Fruits & Vegetables

9. Broad Leaf Vegetation

10. Seawater

11. Bottom Sediment

12. Aquatic Flora (Fucus)

13. Fin Fish

14. Oysters

15. Clams

16. Lobster 3-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station PERIOD 1Q 2Q 3Q 4Q PERIOD 1Q 2Q 3Q 4Q PERIOD 1Q 2Q 3Q 4Q PERIOD 1Q 2Q 3Q 4Q 1 (+/~) 7.2 0.6 7.8 0.5 8.0 0.6 8.1 0.6 12X (+/-) 6.6 0.7 7.0 0.4. 7.2 0.8 7.3 0.6 46 (+/-) 6.5 0.8 8.7 0.6 7.7 0.7 8.7 0.8 59 (+/-) 6.7 0.6 7.9 0.5 7.7 0.7 7.9 0.6 2 (+/-) 9.2 0.8 9.9 0.5 9.4 0.9 9.9 0.7 13C (+/-) 7.0 0.6 8.5 0.7 8.2 0.7 9.4 0.9 47 (+/-) 6.8 0.8 7.5 0.7 7.4 0.7 8.1 0.6 60 (+/-) 5.9 0.6 6.9 0.4 6.7 0.5 6.5 0.5 Annual Radiological Environmental Operating Report 2015 TABLE 1 QUARTERLY GAMMA EXPOSURE RATE (uR/hr)* LOCATIONS (C =control, background locations; X =extra locations not required by REMODCM) 3 (+/-) 6.6 0.5 6.8 0.6 7.4 0.6 8.2 0.6 14C (+/-) 7.3 0.5 9.1 0.5 8.6 0.6 9.2 0.7 48 (+/-) 8.2 0.8 9.4 0.6 9.1 0.7 9.8 0.8 61 (+/-) 6.0 0.4 7.0 0.8 7.3 0.8 7.3 0.5 4 (+/-) 6.9 0.7 7.4 0.5 7.0 0.8 8.0 0.6 15C (+/-) 6.7 0.7 7.4 0.4 7.4 0.6 8.5 0.5 49 (+/-) 6.0 0.6 6.8 0.5 6.6 0.6 6.9 0.5 62 (+/-) 6.6 0.7 7.9 0.5 7.9 0.6 8.0 0.8 5 (+/-) 8.2 0.8 9.3 6.6 9.4 0.9 9.6 0.9 16C (+/-) 5.7 0.6 6.1 0.5 5.9 0.4 6.5 0.6 50 (+/-) 6.6 0.7 7.3 0.5 7.2 0.5 7.8 0.8 63 (+/-) 7.5 0.8 8.2 0.5 8.4 0.9 8.3 1.2 6 (+/-) 8.3 0.7 8.7 0.4 8.4 0.6 9.1 0.6 27 (+/-) 8.6 1.2 7.1 0.5 7.1 0.8 8.0 0.6 51 (+/-) 5.6 0.4 6.0 0.6 5.9 0.4 6.4 0.5 64 (+/-) 6.6 0.7 7.3 0.7 7.5 0.6 7.2 0.6 7 (+/-) 6.1 0.5 4.9 0.3 4.4 0.4 5.1 0.4 41 (+/-) 6.3 0.5 6.3 0.3 6.2 0.6 6.7 0.8 52 (+/-) 6.2 0.7 7.1 0.6 6.8 0.8 7.5 0.6 65 (+/-) 6.8 0.6 8.0 0.8 7.8 0.5 8.0 0.7 8 (+/-) 9.6 0.8 11.3 0.7 10.9 0.8 11.6 0.9 42 (+/-) 5.8 0.6 7.1 0.4 7.0 0.7 7.7 0.6 53 (+/-) 6.3 0.6 7.1 0.5 6.9 0.5 7.6 0.6 66X (+/-) 7.0 0.6 7.1 0.4 7.2 0.6 7.5 0.6

READINGS ARE THE AVERAGE OF MUL Tl CaSo4(Tm) PHOSPHOR ELEMENTS WITHIN ONE PANASONIC TLD BADGE ERRORS ARE TWO SIGMA AND INCLUDE COUNTING, TRANSIT, READER AND FADE UNCERTAINTIES 3-8 9

(+/-) 9.1 1.0 11.3 0.9 11.0 0.8 11.9 0.9 43 (+/-) ~.5 0.5 7.3 0.8 6.9 0.6 7.4 0.5 55 (+/-) 7.2 0.6 7.2 0.6 6.9 0.6 7.4 0.5 73X (+/-) 7.3 1.0 7.6 0.6 7.8 0.7 8.2 0.7 10 (+/-) 9.4 0.7 9.1 0.5 8.1 0.8 9.2 0.6 44 (+/-) 7.8 0.6 7.9 0.5 7.4 0.9 8.6 0.7 56 (+/-) 6.5 0.5 6.9 1.2 6.6 0.6 7.2 0.6 74X (+/-) 6.6 0.6 7.6 0.5 7.5 0.6 7.7 0.6 11 (+/-) 6.1 0.8 7.0 0.5 6.4 0.5 7.3 0.6 45 (+/-) 6.6 0.7 7.1 0.5 7.1 0.7 7.7 0.7 57 (+/-) 6.0 0.6 7.2 0.5 7.2 0.7 7.1 0.6 75X (+/-) 6.2 0.5 6.6 0.4 6.7 0.6 6.9 0.5

Dominion Nuclear Connecticut, Inc. Millstone Power Station PERIOD ENDING 01/13/15 01/26/15 02/10/15 02/24/15 03/10/15 03/24/15 04/07/15 04/21/15 05/05/15 05/19/15 06/02115 06/16/15 06/30/15 07/14/15 07/28/15 08/11/15 08/25/15 09/08/15 09/22/15 10/06/15 10/20/15 11/03/15 11/17/15 12/01/15 12/15/15 12/29/15 01

----------r+t:;--*

0.016 0.002 0.014 0.002 0.016 0.002 0.018 0.002 0.018 0.002 0.010 0.002 0.013 0.002 0.019 0.002 0.007 0.002 0.021 0.002 0.012 0.002 0.010 0.002 0.010 0.002 0.010 0.002 0.013 0.002 0.013 0.002 0.016 0.002 0.022 0.002 0.019 0.002 0.010 0.002 0.012 0.002 0.015 0.002 0.018 0.002 0.012 0.002 0.023 0.002 0.011 0.002 02

f+i'..r-*

0.015 0.002 0.013 0.002 0.015 0.002 0.018 0.002 0.018 0.002 0.011 0.002 0.012 0.002 0;011 0.002 0.006 0.002 0.015 0.002 0.010 0.002 0.006 0.001 0.006 0.001 0.010 0.002 0.010 0.002 0.014 0.002 0.013 0.002 0.020 0.002 0.017 0.002 0.010 0.002 0.012 0.002 0.012 0.002 0.017 0.002 0.015 0.002 0.021 0.002 0.010 0.002 Annual Radiological Environmental Operating Report 2015 TABLE 2 AIR PARTICULATES GROSS BETA RADIOACTIVITY (pCi/m3) LOCATIONS (C =control, background location) 03

r+1.r--

o.014 0.002 0.012 0.002 0.014 0.002 0.021 0.002 O.Q18 0.002 0.012 0.002 0.014 0.002 0.010 0.002 0.005 0.002 0.016 0.002 0.011 0.002 0.006 0.002 0.007 0.002 0.013 0.002 0.012 0.002 0.014 0.002 0.012 0.002 0.021 0.003 O.Q18 0.002 0.009 0.002 0.013 0.002 0.016 0.002 0.018 0.002 0.011 0.002 0.021 0.002 0.008 0.002 04

----------(+i:;--*

0.014 0.002 0.012 0.002 0.015 0.002 0.019 0.002 0.021 0.003 0.011 0.002 0.016 0.002 0.010 0.002 0.005 0.001 0.017 0.002 0.010 0.002 0.008 0.002 0.007 0.002 0.014 0.002 0.011 0.002 0.015 0.002 0.015 0.002 0.023 0.003 0.019 0.002 0.010 0.002 0.012 0.002 0.013 0.002 0.019 0.002 0.012 o.qo2 0.021 0.002 0.010 0.002 3-9 10

f+i'..r-*

0.015 0.002 0.013 0.002 0.015 0.002 0.020 0.002 0.020 0.002 0.012 0.002 0.014 0.002 0.009 0.002 0.008 0.002 0.015 0.002 0.011 0.002 0.009 0.002 0.007 0.002 0.012 0.002 0.011 0.002 0.015 0.002 0.012 0.002 0.019 0.002 0.017 0.002 0.008 0.002 0.011 0.002 0.012 0.002 0.017 0.002 0.013 0.002 0.021 0.002 0.010 0.002 11

(+1.;---

0.015 0.002 0.014 0.002 0.015 0.002 0.018 0.002 0.021 0.002 0.011 0.002 0.015 0.002 0.010 0.002 0.007 0.002 0.018 0.002 0.014 0.002 0.008 0.002 0.008 0.002 0.012 0.002 0.013 0.002 0.013 0.002 0.016 0.002 0.020 0.002 0.019 0.002 0.010 0.002 0.011 0.002 0.013 0.002 0.017 0.002 0.012 0.002 0.023 0.002 0.010 0.002 27

---------(+i~}--*

0.014 0.002 0.015 0.002 0.016 0.002 0.017 0.002 0.020 0.002 0.012 0.002 0.015 0.002 0.011 0.002 0.004 0.001 O.Q18 0.002 0.014 0.002 0,.007 0.001 0.008 0.002 0.012 0.002 0.011 0.002 0.012 0.002 0.015 0.002 0.021 0.002 0.017 0.002 0.009 0.002 0.011 0.002 0.014 0.002 0.019 0.002 0.012 0.002 0.023 0.002 0.013 0.002 15C

,+,:r-*

0.014 0.002 0.013 0.002 0.013 0.002 0.020 0.002 0.019 0.002 0.013 0.002 0.014 0.002 0.009 0.002 0.007 0.002 0.019 0.002 0.011 0.002 0.008 0.002 0.011 0.002 0.012 0.002 0.013 0.002 0.014 0.002 0.014 0.002 0.021 0.003 0.017 0.002 0.012 0.002 0.012 0.002 0.015 0.002 0.017 0.002 0.014 0.002 0.020 0.002 0.011 0.002

Dominion Nuclear Connecticut, Inc. Millstone Power Station PERIOD ENDING 01/13/15 01/26/15 02/10/15 02/24/15 03/10/15 03/24/15 04/07/15 04/21/15 05/05/15 05/19/15 06/02/15 06/16/15 06/30/15 07/14/15 07/28/15 08/11/15 08/25/15 09/08/15 09/22/15 10/06/15 10/20/15 11/03/15 11/17/15 12/01/15 12/15/15 12/29/15 01

i~i~l----

0.006 0.007 0.000 O.Q15 -0.011 -0.001 -0.006 -0.022 0.006 0.004 -0.005 0.000 -0.003 0.021 0.002 0.003 -0.004 0.005 0.008 -0.001 -0.003 -0.002 0.002 -0.007 -0.014 0.011 -0.010 0.007 0.028 0.006 0.030 0.020 0.017 0.011 0.014 0.017 0.010 0.029 0.011 0.007 0.006 0.023 0.025 0.010 0.019 0.011 0.024 0.034 0.028 0.022 0.023 0.030 02

----------~i=i*--

0.007 0.008 0.000 O.Q18 -0.014 -0.001 -0.006 -0.025 0.007 0.011 -0.006 0.000 -0.003 0.021 0.002 0.003 -0.004 0.005 0.008 -0.001 -0.003 -0.002 0.002 -0.007 -O.Q15 0.011 -0.010 0.007 0.036 0.007 0.035 0.022 0.019 0.032 0.016 0.017 0.010 0.029 0.011 0.008 0.006 0.023 0.026 0.009 0.019 O.Q11 0.024 0.035 0.028 0.022 0.024 0.030 Annual Radiological Environmental Operating Report 2015 TABLE 3 AIRBORNE IODINE (1-131) (pCi/m3) LOCATIONS (C =control, background location) 03

----------i;i-i __ _

0.006 0.007 0.000 0.015 -0.012 0.030 -0.001 0.006 -0.006 0.030 -0.022 0.020 0.006 0.017 0.009 0.028 -0.005 O.Q15 -0.001 0.019 -0.003 0.012 0.023 0.032 0.002 0.013 0.004 0.009 -0.005 0.007 0.006 0.027 0.009 0.030 -0.001 0.011 -0.004 0.022 -0.002 0.012 0.002 0.029 -0.009 0.041 -0.016 0.031 0.011 0.023 -0.011 0.025 0.007 0.032 04

(.;:ff*-*

0.007 0.008 0.000 0.018 -0.015 -0.001 -0.007 -0.026 0.007 0.010 -0.005 -0.001 -0.003 0.022 0.002 0.004 -0.005 0.006 0.009 -0.001 -0.003 -0.002 0.002 -0.008 -0.016 0.012 -0.011 -0.010 0.036 0.007 0.036 0.024 0.020 0.030 0.014 0.018 0.011 0.031 0.012 0.008 0.006 0.026 0.028 0.010 0.021 0.012 0.027 O.Q38 0.031 0.024 0.026 0.031 3-10 10

(.;:i_r--*

-0.004 0.008 0.010 0.016 0.003 0.003 0.003 -0.002 0.007 0.010 0.007 -0.011 0.014 0.002 0.001 0.010 0.002 -0.019 0.016 0.000 -0.010 0.001 -O.D18 -0.012 -0.001 0.001 -0.018 -0.009 0.033 0.006 0.033 0.Q18 0.010 0.028 0.015 O.Q18 0.019 0.034 0.005 0.008 0.007 0.039 0.028 0.003 0.019 0.010 0.029 0.034 0.027 0.032 0.036 0.027 11

(;ff*-*

-0.003 0.008 0.009 O.Q15 0.003 0.030 0.003 0.005 0.002 0.029 -0.002 0.016 0.006 0.009 0.004 0.025 0.006 0.014 -0.010 0.017 0.013 0.017 0.002 0.030 -0.002 0.010 0.009 0.008 0.002 0.006 -0.017 0.033 O.Q18 0.031 -0.002 0.011 -0.011 0.021 0.001 0.011 -0.020 0.032 -0.013 0.038 -0.002 0.029 0.001 0.035 -0.020 0.039 -0.009 0.029 27

i~i~,----

-0.004 0.009 0.011 0.018 0.004 0.003 0.003 -0.003 0.008 0.005 0.006 -0.010 0.015 0.002 -0.002 0.009 0.002 -0.017 .0.018 -0.002 -0.011 0.001 -0.021 -0.013 -0.002 0.001 -0.019 -0.005 0.040 0.006 0.037 0.020 0.011 0.033 O.Q15 O.Q18 0.020 0.027 0.010 0.008 0.006 0.034 0.032 0.011 0.021 0.011 0.033 0.038 0.029 0.036 0.038 O.Q16 15C

----------r.. iT--

-0.004 0.008 0.010 0.016 0.003 0.034 0.003 0.006 0.003 0.035 -0.003 0.020 0.007 0.011 0.004 0.028 0.006 0.014 -0.010 0.017 0.013 0.017 0.002 0.029 -0.002 0.011 0.009 0.008 0.002 0.006 -O.Q18 0.035 0.018 0.033 -0.002 0.012 -0.012 0.022 0.001 0.011 -0.021 0.033 -0.014 0.040 -0.002 0.030 0.001 0.036 -0.020 0.040 -0.010 0.031

Dominion Nuclear Connecticut, Inc. Millstone Power Station LOCATION Be-7

(+7:,-----

01 0.0966 0.0297 02 0.1600 0.0575 03 0.1307 0.0433 04 0.0875 0.0735 10 0.1176 0.0531 11 0.1253 0.0420 27 0.1907 0.0667 15C 0.1265 0.0409 LOCATION Ru-103

(+7:,-----

01 0.0007 0.0041 02 0.0407 0.0531 03 -0.0034 0.0057 04 0.0002 0.0093 10 0.0004 0.0061 11 -0.0059 0.0059 27 -0.0048 0.0088 15C -0.0017 0.0040 LOCATION Be-7

(+7:,-----

01 0.1016 0.0428 02 0.1069 0.0277 03 0.1275 0.0537 04 0.1406 0.0476 10 0.1192 0.0507 11 0.1099 0.0413 27 0.1061 0.0382 15C 0.1433 0.0394 LOCATION Ru-103

(+1:,*---*

01 0.0022 0.0037 02

0.0013 0.0049 03 0.0065 0.0074 04

-0.0023 0.0055 10 0.0042 0.0080 11 . *0.0006 0.0035 27

0.0012 0.0041 15C

-0.0057 0.0055 Annual Radiological Environmental Operating Report 2015 TABLE4 AIR PARTICULATES (pCi/m3) (15C =control, background location) GAMMA SPECTRA-QTR 1 (12/30/14 - 04/07/15) Mn-54 Co-58 Co-60 Zn-65

-----------r+r.r---*

(+i:j ____

-----------c:;:i-r---* ------------r+1:;-*--

0.0005 0.0011 0.0010 0.0019 0.0008 0.0008 0.0028 0.0029 0.0019 0.0104 -0.0077 0.0267 -0.0019 0.0098 0.0141 0.0240 0.0000 0.0017 0.0014 0.0036 0.0010 0.0012 -0.0010 0.0036 ~0.0014 0.0028 -0.0002 0.0039 -0.0016 0.0019 0.0058 0.0066 0.0007 0.0017 0.0020 0.0024 0.0013 0.0018 -0.0005 0.0041 -0.0002 0.0014 -0.0008 0.0022 -0.0005 0.0012 0.0000 0.0029 -0.0014 0.0023 -0.0035 0.0053 0.0002 0.0031 0.0009 0.0046 0.0003 0.0014 -0.0022 0.0022 0.0000 0.0009 0.0005 0.0031 Ru-106 Cs-134 Cs-137 Ba-140

-----------r;:r.r---* ------------Fr---
-----------c:;:1-r---* *-----------r+,:r*--

-0.0139 0.0131 -0.0001 0.0012 0.0003 0.0010 -0.0020 0.4906 0.0571 0.1124 0.0050 0.0103 -0.0058 0.0106 -0.9744 5.8260 0.0042 0.0133 0.0002 0.0013 0.0003 0.0015 -0.2647 0.7735 -0.0115 0.0213. 0.0028 0.0021 0.0016 0.0019 -0.1101 1.0220 0.0031 0.0145 -0.0001 0.0018 -0.0004 0.0015 0.1637 0.7549 -0.0085 0.0110 -0.0003 0.0011 -0.0003 0.0010 -0.2590 0.5423 0.0057 0.0250 0.0026 0.0024 0.0007 0.0022 -0.2331 1.1510 -0.0065 0.0100 0.0004 0.0011 -0.0011 0.0010 -0.0005 0.5666 GAMMA SPECTRA-QTR 2 (04/07/15 -06/30/15) Mn-54 Co-58 Co-60 Zn-65

-----------r+r.r---*

(+i=j ____ *-----------Fi-r---* ------------r+1:;-*--

0.0002 0.0011 -0.0018 0.0023 -0.0002 0.0013 -0.0001 0.0028 0.0001 0.0010 -0.0010 0.0026 0.0007 0.0012 0.0011 0.0036 0.0001 0.0023 0.0005 0.0050 0.0007 0.0024 0.0038 0.0065 0.0003 0.0017 0.0009 0.0032 -0.0012 0.0014 0.0015 0.0037 0.0007 0.0021 0.0011 0.0034 0.0004 0.0019 0.0036 0.0041 0.0001 0.0012 0.0006 0.0015 0.0007 0.0009 0.0003 0.0023 -0.0011 0.0015 0.0002 0.0024 0.0005 0.0011 0.0002 0.0035 0.0002 0.0016 0.0000 0.0026 0.0005 0.0016 0.0009 0.0039 Ru-106 Cs-134 Cs-137 Ba-140

----------*r+1:r*--* -----------*Fr**-
-----------<+1-r*--* ------------f+,:r*--

0.0033

0.0090 0.0007 0.0011 0.0006 0.0013 0.0007 0.3877
0.0058 0.0113 0.0008 0.0013 0.0012 0.0009
0.1350 0.4362
0.0100 0.0225 0.0020 0.0020

-0.0007 0.0020 0.0380 0.8127 0.0089 0.0105

0.0006 0.0013

-0.0003 0.0014 -0.1254 0.5343 0.0110 0.0145 0.0009 0.0017 0.0002 0.0017 0.2946 0.6238 0.0012 0.0088 0.0003 0.0011

0.0003 0.0009 0.2200 0.3246

-0.0017 0.0104 0.0019 0.0013

0.0004 0.0010
0.1183 0.4492 0.0163 0.0143 0.0015 0.0015
0.0003 0.0012 0.4738 0.4849 3-11 Nb-95 Zr-95

1+i=-,-----

-----------r+i-r*--*

-0.0001 0.0023 0.0031 0.0040 0.0175 0.0274 -0.0384 0.0464 0.0030 0.0037 -0.0035 0.0063 0.0032 0.0054 -0.0018 0.0091 0.0014 0.0035 -0.0014 0.0060 -0.0021 0.0029 0.0005 0.0049 -0.0024 0.0060 -0.0030 0.0114 0.0007 0.0027 0.0026 0.0042 Ce-141 Ce-14.4

(+i'.y----

-----------Fi-r---*

0.0023 0.0078 -0.0003 0.0057 -0.0245 0.0802 0.0383 0.0535 0.0013 0.0098 -0.0017 0.0066 -0.0053 0.0174 -0.0012 0.0127 0.0025 0.0090 -0.0071 0.0069 0.0033 0.0087 -0.0035 0.0064 0.0009 0.0124 0.0015 0.0086 0.0038 0.0082 0.0015 0.0060 Nb-95 Zr-95

1+1=-i-----

-----------Fi-r---*

-0.0004 0.0023 -0.0011 0.0037 0.0018 0.0028 -0.0073 0.0050 0.0035 0.0049 -0.0032 0.0082 0.0006 0.0035 0.0015 0.0056 -0.0004 0.0036

0.0010 0.0068

-0.0018 0.0025 0.0036 0.0039 0.0019 0.0028 0.0017 0.0049 -0.0012 0.0031 0.0013 0.0054 Ce-141 Ce-144

1+1:-i--*--

-----------Fi-r**-*

0.0083. 0.0071 0.0026 0.0054

0.0010 0.0070 0.0023 0.0057 0.0083 0.0097

-0.0028 0.0061 0.0004 0.0088 0.0023 0.0073

0.0023 0.0109 0.0003 0.0090

-0.0009 0.0066

0.0032 0.0054 0.0025 0.0072 0.0029 0.0065 0.0018 0.0096 0.0042 0.0077

Dominion Nuclear Connecticut, Inc. Millstone Power Station LOCATION Be-7

(+i~-----

01 0.1339 0.0457 02 0.0960 0.0348 03 0.1214 0.0318 04 0.1185 0.0426 10 0.1136 0.0321 11 0.0862 0.0288 27 0.1839 0.0422 15C 0.1264 0.0549 LOCATION Ru-103

(+i~-----

01 -0.0027 0.0069 02 0.0012 0.0041 03 0.0009 0.0042 04 -0.0005 0.0041 10 0.0043 0.0042 11 0.0000 0.0051 27 -0.0069 0.0039 15C 0.0004 0.0077 LOCATION Be-7

(+i~-----

01 0.0940 0.0301 02 0.1001 0.0361 03 0.0843 0.0381 04 0.0961 0.0422 10 0.1010 0.0352 11 0.1020 0.0298 27 0.1090 0.0338 15C 0.0717 0.0312 LOCATION Ru-103

(+i=,-----

01 -0.0002 0.0037 02 -0.0032 0.0070 03 0.0019 0.0043 04 0.0003 0.0042 10 -0.0019 0.0048 11 -0.0014 0.0039 27 -0.0013 0.0034 15C 0.0004 0.0032 Annual Radiological Environmental Operating Report 2015 TABLE4 AIR PARTICULATES (pCi/m3) GAMMA SPECTRA-QTR 3 (06/30/15 - 10/06/15) Mn-54 Co-58 Co-60 Zn-65

-----------r+i-r---*

(+i:r---

-----------Fi~-----

r+q----

-0.0006 0.0018 -0.0013 0.0035 -0.0004 0.0014 0.0027 0.0037 0.0004 0.0011 -0.0010 0.0022 0.0002 0.0009 0.0029 0.0030 -0.0002 0.0010 0.0015 0.0024 0.0007 0.0010 0.0019 0.0040 -0.0011 0.0009 -0.0004 0.0022 -0.0010 0.0010 -0.0017 0.0030 -0.0007 0.0010 -0.0004 0.0026. 0.0011 0.0012 0.0017 0.0033 -0.0005 0.0012 -0.0013 0.0025 -0.0001 0.0013 0.0038 0.0032 -0.0002 0.0011 0.0002 0.0025 -0.0006 0.0008 -0.0012 0.0027 -0.0008 0.0019 -0.00'20 0.0031 0.0014 0.0016 0.0015 0.0045 Ru-106 Cs-134 Cs-137 Ba-140

-----------r+i-r---*

(+i:i ____ *-----------Fi-r---* ------------r+1:j ____

0.0040 0.0140 0.0025 0.0020 -0.0003 0.0015 -0.0247 0.8042 0.0081 0.0094 0.0008 0.0012 -0.0001 0.0010 -0.0282 0.3596 0.0035 0.0101 0.0035 0.0014 0.0010 0.0010 -0.1019 0.5216 -0.0010 0.0105 -0.0010 0.0012 0.0010 0.0011 -0.0016 0.4223 -0.0062 0.0114 0.0013 0.0012 -0.0004 0.0010 0.0965 0.5611 -0.0017 0.0107 0.0008 0.0011 0.0000 0.0008 0.0875 0.6066 -0.0028 0.0115 -0.0003 0.0011 0.0008 0.0012 -0.1457 0.5858 -0.0051 0.0147 0.0005 0.0018 -0.0010 0.0018 0.0188 0.8558 GAMMA SPECTRA-QTR 4 (10/06/15 - 12/29/15) Mn-54 Co-58 Co-60 Zn-65

-----------f+i-r---*

(+i:i ____ *-----------Fi-r---* ------------r+q----

0.0004 0.0014 0.0017 0.0019 0.0005 0.0011 0.0022 0.0030 -0.0004 0.0020 0.0006 0.0033 -0.0008 0.0023 0.0062 0.0057 0.0003 0.0011 -0.0028 0.0027 0.0022 0.0016 -0.0033 0.0036 0.0000 0.0014 -0.0014 0.0029 -0.0012 0.0013 0.0017 0.0033 0.0004 0.0018 0.0010 0.0031 0.0004 0.0013 0.0021 0.0045 -0.0001 0.0012 -0.0006 0.0026 -0.0002 0.0013 -0.0007 0.0030 0.0005 0.0012 -0.0008 0.0014 0.0004 0.0005 -0.0004 0.0026 0.0001 0.0011 -0.0016 0.0020 -0.0002 0.0009 0.0034 0.0029 Ru-106 Cs-134 Cs-137 Ba-140

-----------f+i-r---*

(+i:r---

-----------Fi-r---* ------------r+,:r---

0.0032 0.0119 0.0014 0.0012 0.0002 0.0010 0.0238 0.2170 0.0035 0.0201 0.0015 0.0019 0.0007 0.0020 -0.2509 0.3692 0.0052 0.0115 -0.0001 0.0014 -0.0005 0.0013 -0.0790 0.2377 -0.0101 0.0128 0.0013 0.0013 0.0002 0.0012 0.1546 0.2243 -0.0045 0.0145 0.0006 0.0019 0.0006 0.0014 -0.1319 0.3111 -0.0110 0.0116 0.0005 0.0011 0.0009 0.0011 -0.0540 0.2216 0.0009 0.0087 -0.0005 0.0010 0.0002 0.0008 0.0260 0.2191 0.0084 0.0086 -0.0005 0.0009 0.0007 0.0009 0.1427 0.1942 3-12 Nb-95 Zr-95

(+j:,-----

-----------Fi-r---*

-0.0011 0.0036 -0.0036 0.0063 0.0018 0.0021 0.0009 0.0040 0.0017 0.0026 -0.0021 0.0046 0.0012 0.0028 -0.0010 0.0044 0.0020 0.0028 -0.0017 0.0052 0.0002 0.0029 0.0003 0.0051 -0.0006 0.0026 -0.0028 0.0051 0.0022 0.0045 -0.0024 0.0077 Ce-141 Ce-144

(+i=,-----

-----------,+i-r---*

-0.0034 0.0098 0.0013 0.0074 -0.0006 0.0071 -0.0011 0.0047 -0.0050 0.0082 0.0010 0.0059 -0.0040 0.0082 -0.0049 0.0054 -0.0002 0.0080 0.0017 0.0055 0.0007 0.0086 0.0000 0.0062 -0.0028 0.0077 -0.0031 0.0056 -0.0035 0.0105 0.0038 0.0076 Nb-95 Zr-95

(+i=,-----

-----------(+i-i ____,

-0.0010 0.0021 0.0015 0.0036 -0.0009 0.0035 -0.0002 0.0067 -0.0015 0.0031 0.0039 0.0042 0.0006 0.0026 0.0004 0.0048 -0.0004 0.0032 -0.0019 0.0057 -0.0001 0.0023 0.0044 0.0044 -0.0007 0.0018 -0.0006 0.0029 0.0005 0.0021 -0.0010 0.0040 Ce-141 Ce-144

(+i~-----

-----------,+i-r---*

0.0031 0.0065 -0.0031 0.0068 0.0104 0.0081 -0.0075 0.0085 -0.0076 0.0075 0.0051 0.0074 -0.0018 0.0063 -0.0029 0.0059 -0.0020 0.0077 -0.0008 0.0081 -0.0025. 0.0064 -0.0032 0.0071 0.0010 0.0053 -0.0013 0.0054 0.0028 0.0055 0.0011 0.0052

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Be-7 (+/-) 03 11/03/15 0.120 0.534 04 11/03/15 0.084 0.777 14C 11/03/15 0.323 0.820 (14C =control, background location) COLLECTION LOCATION DATE Co-60 (+/-) 03 11/03/15 -0.027 0.051 04 11/03/15 -0.042 0.084 14C 11/03/15 -0.061 0.076 COLLECTION LOCATION DATE Sb-125 (+/-) 03 11/03/15 0.030 0.130 04 11/03/15 0.127 0.172 14C 11/03/15 .0.140 0.248 Annual Radiological Environmental Operating Report 2015 TABLE 5 SOIL (pCi/g dry wt.) K-40 Cr-51 Mn-54 (+/-) (+/-) (+/-) 13.100 1.587 -0.122 0.599 0.008 0.054 15.110 3.027 -1.040 0.932 0.031 0.098 13.750 2.354 0.038 0.999 0.009 0.080 Zn-65 Nb-95 Zr-95 (+/-) (+/-) (+/-) 0.022 0.130 0.030 0.058 0.144 0.099 -0.325 0.195 0.048 0.107 -0.074 0.211 -0.096 0.215 0.111 0.096 -0.030 0.164 .cs-134 Cs-137 Ce-141 (+/-) (+/-) (+/-) -0.023 0.057 0.167 0.080 0.001 0.116 -0.029 0.092 0.517 0.155 0.072 0.167 -0.073 0.096 0.338 0.185 -0.121 0.178 Co-58 Fe-59 (+/-) (+/-) -0.016 0.051 -0.040 0.124 -0.036 0.099 0.037 0.208 0.046 0.087 0.077 0.183 Ru-103 Ru-106 (+/-) (+/-) 0.019 0.061 0.028 0.442 0.030 0.112 -0.112 0.711 -0.024 0.096 -0.042 0.708 Ce-144 Ac-228 (+/-) (+/-) -0.551 0.388 1.076 0.370 -0.464 0.544 0.720 0.832 0.187 0.608 0.347 0.642 Note: Extra counts detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. 3-13 Note

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE 1-131

*-----------* *----------Fi-r--*

22 01/21/15 -0.132 0.083 02/18/15 -0.211 0.148 03/11/15 0.133 0.223 04/15/15 -0.526 0.347 05/13/15 -0.208 0.322 05/27/15 -0.441 0.206 06/10/15 -0.171 0.345 06/22/15 -0.303 0.199 07/08/15 0.006 0.211 07/23/15 -0.179 0.139 08/12/15 -0.119 0.190 08/26/15 . -0.571 0.499 09/16/15 -0.298 0.349 09/28/15 -0.157 0.458 10/13/15 -0.069 0.196 10/27/15 -0.638 0.224 11/18/15 0.092 0.415 12/08/15 -0.220 0.248 Annual Radiological Environmental Operating Report 2015 TABLE 6 COW MILK (pCi/I) Sr-89 Sr-90 K-40 Cs-134 Cs-137

(+i-)" --------f+t=i* *---------r;-,:j--

,+!~)----- -----------T+tT ___

1226 120 0.711 3.973 2.946 3.538 1295 205 -6.748 6.098 4.754 6.112 4.9 2.7 0.7 1.3 1352 178 2.921 4.703 -2.471 4.336 1203 112 0.668 2.987 1.238 2.898 1249 186 5.351 7.164 2.682 6.240 1224 170 -0.256 4.364 3.123 4.349 1254 192 0.177 4.933 1.279 5.281 3.1 4.0 0.0 0.9 1186 185 -5.860 5.091 0.312 5.231 1360 148 -1.967 3.710 -0.162 3.364 1212 153 -2.154 5.144 2.243 4.211 1217 188 -3.266 6.888 -0.891 7.155 1373 237 -1.491 6.586 -0.996 5.847 1379 250 -10.330 6.599 0.381 6.839 7.4 5.9 0.5 0.4 1102 174 -3.461 4.465 0.011 4.768 1314 214 4.950 5.419 -1.614 5.318 1251 201 -3.238 4.829 0.986 5.200 1211 213 -3.238 7.696 0.168 7.672 4.7 3.2 0.7 0.7 1284 127 -0.693 2.780 -0.967 3.165 3-14 Ba-140 La-140

-----------,+i-r---- *-----------f +r-r---

-10.800 15.650 1.426 5.418 21.580 29.690 -2.854 9.028 -3.004 24.780 2.192 5.964 -1.231 14.630 2.791 5.011 28.800 28.500 6.665 9.012 3.913 22.070 -0.041 4.513 -7.014 24.410 4.429 6.763 -5.341 21.110 -0.136 6.032 11.170 15.530 -0.486 3.898 1.566 20.320 1.918 6.529 -10.020 29.930 -2.299 7.536 -8.&77 28.100 4.742 9.184 -1.172 31.820 0.275 7.201 -2.659 23.600 5.516 8.152 8.551 22.390 -1.510 6.276 -3.325 23.210 3.736 5.861 20.710 24.980 4.292 7.229 11.850 12.990 -2.151 4.244

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE H-3

F-i-Y-71 06/23/15 246 513 09/22/15

-184 502 12/10/15 -83 556 72 06/22/15 534 523 09/21/15 13 518 12/09/15 476 595 76 06/18/15 83 491 09/15/15 368 593 12/07/15 -586 590 77 06/18/15 573 530 09/15/15 165 579 12/07/15 45 565 78 06/18/15 438 514 09/15/15 -32 563 12/07/15 488 740 79 06/22/15 523 529 09/21/15 438 551 12/09/15 548 602 81 06/22/15 749 546 09/21/15 89 524 12/10/15 388 591 82 06/22/15 677 540 09/22/15 -419 481 12/10/15 216 577 83 06/22/15 544 528 09/21/15 -362 486 12/10/15 13 561 Annual Radiological Environmental Operating Report 2015 TABLE 7 WELL WATER (pCi/I} Be-7 K-40 Cr-51 Mn-54 Co-58

r+i-r-

---------Ft:;--*

F-i-Y-

Fr*

---------(+7:y-*

-31.2 32.7 -44.3 53.8 -39.3 32.5 3.9 3.3 -0.5 4.3 22.9 33.1 37.8 41.3 -9.7 35.3 -2.2 4.0 -3.4 3.4 13.0 28.6 54.7 47.1 -36.7 31.3 0.2 2.7 0.3 3.3 -7.9 29.4 6.4 38.7 -14.8 33.1 -1.8 3.4 -1.1 3.4 23.8 42.0 -7.3 67.5 6.0 52.3 -1.6 5.0 -0.1 4.7 19.1 23.9 11.6 49.9 -2.8 28.2 -2.6 2.7 0.9 2.6 12.8 31.4 -8.25 49.48 -49.3 36.5 -0.8 3.48 -0.46 3.68 -30.9 48.6 48.2 104.6 39.6 49.5 -3.3 6.2 0.0 6.0 -20.6 44.3 -5.1 80.9 2.1 53.8 -5.0 6.9 -0.8 5.4 -17.2 33.2 -5.7 53.8 5.3 37.3 1.1 4.4 0.9 4.0 -46.0 41.1 29.2 71.4 0.3 53.8 4.0 4.9 -0.2 5.0 16.6 48.8 56.9 92.3 29.9 50.2 -6.4 6.0 -6.5 6.8 1.38 27.2 127 61.56 -10.5 32.1 -0.23 2.94 2.23 3.31 7.0 34.8 48.6 82.0 -10.5 36.6 -0.1 4.6 -3.6 4.1 -33.2 54.3 -10.0 78.7 -40.5 53.4 -6.2 6.6 2.0 5.8 -2.2 34.4 34.9 70.2 -2.2 33.9 -0.6 3.4 -0.4 3.7 -15.2 35.1 -29.7 60.0 -31.7 42.5 -1.8 3.5 -1.0 4.2 -11.6 24.9 12.6 35.8 11.5 32.7 -1.0 2.2 -2.3 2.4 4.4 34.8 -33.9 65.2 -11.4 40.0 -1.2 3.2 -0.4 4.3 10.2 46.9 64.6 82.4 23.8 55.1 0.2 4.7 0.6 5.3 -6.5 23.7 18.9 52.5 -29.0 29.9 0.7 2.7 -1.3 2.6 -33.7 38.9 4.6 75.8 25.1 44.5 -4.5 4.3 -3.2 4.3 -54.7 47.5 21.1 72.1 28.4 52.0 -3.3 6.2 1.6 6.9 20.4 25.1 93.2 41.7 3.6 30.1 -1.3 2.5 -2.5 3.0 17.0 35.2 -9.0 65.3 2.9 44.2 -1.3 3.7 -0.3 3.4 46.1 44.0 -78.0 65.8 -20.8 40.2 -5.4 4.8 0.4 4.7 -0.5 25.0 90.6 55.8 -0.1 29.7 0.0 2.7 -3.5 2.6 3-15 Fe-59 Co-60

--------F-ir

r+i-r*

0.5 8.2 -1.1 3.3 1.3 6.5 -0.8 3.7 0.0 6.2 0.9 2.5 -4.7 7.8 2.5 4.1 3.0 9.9 1.4 4.2 -2.3 6.8 2.2 2.7 1.12 6.33 -0.57 3.47 -5.3 12.8 -4.5 6.2 12.2 9.6 1.1 5.8 -3.9 6.8 0.8 4.1 0.9 9.9 3.0 4.3 1.2 11.1 -4.6 5.8 4.05 5.11 -0.02 2.79 -0.1 9.2 -4.7 5.4 -2.3 12.0 3.7 5.3 1.4 7.4 3.0 4.1 5.6 8.0 2.6 3.6 -0.2 3.8 -0.7 1.5 2.9 7.3 -1.0 4.5 4.4 9.0 2.4 4.0 -2.6 5.1 -0.2 2.8 2.7 7.8 0.3 3.6 -2.7 11.3 -0.2 6.7 -1.1 6.0 2.7 2.8 2.2 6.9 -2.7 4.3 3.0 9.8 3.9 4.9 4.8 5.3 1.2 2.3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 TABLE 7 WELL WATER (pCi/I) COLLECTION LOCATION DATE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

------------* ---------Fi-r

Fi-T-

---------(i-i:y--

r+i-r*

--------T+tT.

71 06/23/15 1.9 4.9 -4.5 4.1 0.4 6.7 -4.5 4.5 14.6 41.4 09/22/15 5.6 8.7 4.2 4.4 3.7 6.4 -3.8 4.2 -0.5 34.7 12/10/15 2.4 6.1 3.7 3.1 -2.7 4.8 -3.3 3.7 2.8 27.9 72 06/22/15 -0.4 8.6 -3.0 3.7 -3.6 5.2 1.3 3.4 2.0 34.0 09/21/15 -1.8 11.5 1.0 4.9 -3.9 8.1 -4.2 5.8 -26.2 49.3 12/09/15 -2.1 4.8 0.5 2.9 1.5 4.3 -4.5 3.0 -1.4 20.5 76 06/18/15 -1.5 7.9 -0.7 4.0 -1.4 6.7 1.3 4.2 15.5 34.5 09/15/15 4.5 13.1 1.6 6.0 2.5 10.2 0.0 5.4 -7.1 43.0 12/07/15 9.2 15.2 4.1 5.8 1.0 8.3 -3.3 6.6 -24.2 56.7 77 06/18/15 -0.6 8.9 -1.8 5.0 -0.5 6.4 -0.1 4.1 -10.1 35.9 09/15/15 5.1 10.4 4.9 5.8 5.8 8.6 -4.3 6.2 -3.3 45.0 12/07/15 25.2 15.4 Note 1 9.1 8.7 -7.8 10.4 -1.0 6.1 39.6 53.7 Note 1: Zn-65 was not identified in sample. Counts in Zn-65 peak area were from naturally occuring Bi-214. 78 06/18/15 12.1 6.5 Note2 4.1 3.7 1.6 5.8 -1.7 3.6 10.9 29.2 09/15/15 -16.2 12.8 3.5 4.6 1.2 8.7 3.1 4.4 -28.8 41.0 12/07/15 -9.5 18.1 4.6 5.8 -0.9 9.7 2.3 6.6 8.5 55.9 Note 2: Result for Zn-65 was less thant the minimum detectable activity (MDA). 79 06/22/15 1.9 8.4 2.7 3.6 6.2 6.4 -4.3 3.7 -24.8 34.1 09/21/15 -17.1 11.7 4.0 4.9 -0.8 7.4 1.0 4.5 -10.1 44.2 12/09/15 -6.4 4.5 0.5 2.3 -2.5 4.3 4.2 3.2 -6.9 22.1 81 06/22/15 2.6 8.5 0.8 4.0 -3.8 6.4 -0.1 4.6 4.4 35.4 09/21/15 8.5 10.9 6.4 5.8 -4.3 8.3 -1.8 6.2 -11.6 42.3 12/10/15 2.7 5.6 2.7 2.7 -0.9 4.7 0.7 3.1 -12.5 23.9 82 06/22/15 -4.9 9.2 10.5 4.9 Note3 6.9 7.3 1.1 4.5 19.8 34.6 09/22/15 -0.1 15.9 7.7 7.2 -3.8 10.2 -2.3 5.9 -1.9 50.5 12/10/15 0.0 6.3 6.9 3.7 Note3 -2.2 5.2 -3.7 3.2 3.2 22.1 83 06/22/15 -6.3 8.7 4.3 4.5 -1.1 7.3 -2.0 4.6 15.1 35.4 09/21/15 2.7 12.4 6.7 6.3 0.5 8.3 -0.8 5.1 -23.7 42.0 12/10/15 -4.0 5.4 1.5 2.7 -1.5 5.0 -1.4 3.2 16.6 22.4 Note 3: Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. 3-16 Sb-125 1-131 Cs-134

(+i~--* ---------r+i-r-

---------c-tt:r*

-4.3 11.0 2.9 6.5 -3.3 4.7 -0.7 10.7 -5.0 5.4 0.3 3.9 -4.7 8.3 6.2 8.6 -1.2 3.2 -7.1 10.1 -0.2 5.9 1.9 3.0 0.5 13.4 6.4 7.6 -4.7 5.8 -4.4 7.0 3.9 8.0 0.1 3.5 6.0 10.6 -1.3 6.3 -1.2 3.7 -9.3 13.9 -0.9 8.1 2.3 5.0 -9.5 17.6 0.2 7.4 -0.8 7.0 -11.8 10.3 -1.3 7.1 -1.3 4.3 -5.8 13.9 -3.5 8.6 -1.0 5.8 -10.8 18.2 -5.3 7.3 -1.6 6.4 -12.4 9.3 2.9 5.9 2.5 5.4 4.5 11.6 0.2 7.1 -1.2 4.8 0.7 15.4 -5.9 7.8 4.7 5.9 4.1 ' 9.9 3.2 6.7 2.3 3.6 -8.5 13.9 1.4 6.3 3.9 5.0 -1.8 7.4 2.0 9.7 -0.6 3.0 0.1 11.3 0.6 6.6 -0.1 4.1 2.9 14.5 -3.5 8.2 3.1 5.7 2.5 7.4 3.6 7.5 0.3 2.9 -1.5 12.7 3.0 7.8 1.6 4.5 -3.4 17.2 7.2 7.9 1.0 6.5 -0.4 7.3 2.8 7.9 0.3 2.7 -5.6 11.6 -3.9 7.9 2.4 4.7 -2.0 13.8 0.3 6.6 0.1 5.6 4.1 6.9 4.3 7.9 0.9 2.8

Dominion Nuclear Connecticut, Inc. Millstone Power Station LOCATION 71 72 76 77 78 79 81 82 83 Annual Radiological Environmental Operating Report 2015 TABLE 7 WELL WATER (pCi/I) COLLECTION DATE Cs-137 Ba-140 La-140

Fi~--

Fr.r-

,+r.r-*

06/23/15 -0.5 4.1 4.6 16.5 -3.7 7.0 09/22/15 -0.9 4.2 6.1 15.8 -0.2 4.8 12/10/15 2.8 2.9 16.1 20.1 5.3 6.4 06/22/15 -1.5 3.6 -18.2 16.3 3.1 5.7 09/21/15 -4.8 5.4 -1.3 23.3 3.2 8.1 12/09/15 0.4 2.9 -0.5 16.8 -0.5. 6.0 06/18/15 -0.4 3.7 -4.5 17.0 -1.1 5.5 09/15/15 -6.0 6.4 -25.5 26.0 0.6 8.4 12/07/15 -0.3 6.9 8.4 26.0 -1.1 4.4 06/18/15 -1.4 4.1 -7.8 18.2 1.7 5.9 09/15/15 -3.0 5.6 0.2 26.5 -4.0 7.0 12/07/15 2.3 7.3 0.0 24.9 1.6 8.6 06/18/15 0.2 3.2 -4.9 16.0 -2.6 4.4 09/15/15 3.1 5.1 -3.7 19.5 -6.0 7.5 12/07/15 0.8 6.3 1.3 26.1 2.9 7.7 06/22/15 3.0 3.9 4.5 18.9 2.2 6.5 09/21/15 -2.5 4.3 0.4 19.6 3.2 5.1 12/09/15 1.3 2.4 -1.0 17.5 0.6 3.4 06/22/15 0.9 4.2 7.1 18.7 -1.7 6.9 09/21/15 -4.2 6.3 25.7 23.6 9.3 6.3 12/10/15 -0.7 2.6 0.3 17.4 4.3 5.1 06/22/15 0.3 4.7 -17.5 20.2 -0.8 6.2 09/22/15 -1.5 5.9 3.1 22.1 -0.8 8.1 12/10/15 -2.8 2.9 1.1 18.3 4.7 6.6 06/22/15 -4.6 4.7 11.5 21.1 5.6 7.4 09/21/15 -1.0 4.7 -15.9 19.5 -1.3 6.6 12/10/15 0.1 2.6 0.2 19.1 -2.7 4.6 3-17 Ac-228

--------(+i=-i-*

1.9 14.6 8.2 14.7 6.0 11.2 0.0 14.8 13.6 19.2 13.2 10.2 -9.2 14.2 11.7 21.5 -7.1 21.2 11.1 13.5 12.2 19.2 22.0 23.8 10.9 11.2 1.8 15.3 -11.4 19.7 7.8 14.2 5.6 16.7 -10.8 8.5 -2.1 14.3 '1.0 19.3 -1.8 9.5 4.2 15.4 -15.4 24.2 -2.6 10.0 -4.4 15.2 2.9 18.4 3.3 9.9

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 07/27/15 07/27/15 08/10/15 10/20/15 10/20/15 COLLECTION DATE 07/27/15 07/27/15 08/10/15 10/20/15 10/20/15 COLLECTION DATE 07/27/15 07/27/15 08/10/15 10/20/15 10/20/15 , ____ J.Y.£!: ____ _ Greens Blueberries Tomatoes Eggplant Apples , ____ J.Y.£!: ____ _ Greens Blueberries Tomatoes Eggplant Apples _____ J.Y.£!: ____ _ Greens Blueberries Tomatoes Eggplant Apples Be-7 (+/-) 0.025 0.097 0.046 0.092 0.009 0.072 0.024* 0.063 -0.005 0.062 Zn-65 (+/-) -0.029 0.029 -0.013 0.022 -0.021 0.022 0.002 O.D18 -0.004 0.016 Cs-134 (+/-) -0.002 0.013 -0.019 0.011 -0.009 0.009 -0.014 0.008 -0.017 0.008 Annual Radiological Environmental Operating Report 2015 TABLE 8 FRUITS & VEGETABLES (pCi/g wet wt.) LOCATION 25 (fruit are extra samples not required by the REMODCM) K-40 (+/-) 1.954 0.355 0.809 0.251 2.069. 0.280 2.048*

0.256 1.265 0.226 Nb-95

(+/-) 0.004 0.012 -0.007 0.011 0.008 0.010 0.006 0.008 0.003 0.007 Cs-137 (+/-) -0.004 0.011 -0.003 0.009 0.003 0.008 0.002 0.007 0.003 0.008 Cr-51 (+/-) 0.021 0.109 0.040 0.107 -0.037 0.082 0.034 0.069 0.035 0.069 Zr-95

(+i:;---

-0.006 0.019 -0.001 0.019 0.003 0.016 0.006 0.013 0.008 0.012 Ba-140 ( +/-) -0.014 0.075 -0.035 0.066 0.002 0.047 0.003 0.035 0.030 0.032 3-18 Mn-54 Co-58 (+I-) ( +/-) 0.009 0.011 -0.009 0.012 -0.003 0.009 -0.004 0.010 0.006 0.008 0.002 0.009 0.002 0.007 -0.003 0.009 0.004 0.007 -0.006 0.007 Ru-103 Ru-106 ( +/-)

----------r+i.r--

-0.007 0.013 0.086 0.090 -0.003 0.011 -0.047 0.084 -0.003 0.009 -0.053 0.080 -0.004 0.007 -0.036 0.075 -0.003 0.007 -0.007 0.059 La-140 Ce-141 ( +/-) (+I-) 0.031 0.025 0.017 0.020 -0.011 0.023 -0.023 0.018 -0.003 0.015 0.002 0.014 -0.011 0.009 -0.002 0.012 0.002 0.010 0.001 0.012 Fe-59 Co-60 (+/-) (+/-) -0.008 0.027 -0.007 0.010 0.010 0.022 0.003 0.009 0.018 0.020 -0.002 0.009 -0.014 0.019 -0.006 0.009 -0.005 0.014 0.006 0.008 Sb-125 1-131

Fi-r--*

(~i~---*

0.003 0.029 0.011 0.034 -0.024 0.027 0.009 0.034 0.013 0.023 0.011 0.018 -0.007 0.022 0.015 0.012 -0.007 0.01 ~ -0.001 0.012 Ce-144 Ac-228 (+/-) (+/-) -0.010 0.066 0.012 0.036 0.002 0.058 0.007 0.041 -0.043 0.058 0.009 0.034 0.002 0.049 -0.004 0.030 0.008 0.046 -0.007 0.027

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 TABLE 8 FRUITS & VEGETABLES (pCi/g wet wt.) LOCATION 26 (control, background location; fruit are extra samples not required by the REMODCM) COLLECTION DATE , ____ }_YE~----- Be-7 K-40 Cr-51 Mn-54 Co-58 (+/-) (+/-) (+/-) (+/-) (+/-) 07/27/15 Greens 0.009 0.100 2.168 0.314 -0.036 0.113 0.003 0.011 -0.006 0.011 07/27/15 Blueberries 0.043 0.056 0.803 0.174 0.021 0.078 0.001 0.006 0.006 0.006 10/20/15 Eggplant 0.020 0.071 3.199 0.370 CJ.001 0.073 0.006 0.008 0.001 0.008 10/20/15 Apples 0.051 0.088 0.820 0.243 -0.061 0.081 0.001 0.010 -0.003 0.009 COLLECTION DATE _____ ])~~~----- Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 (+/-) (+/-) (+/-) (+/-) (+/-) 07/27/15 Greens -0.007 0.025 -0.003 0.013 0.022 0.021 -0.004 0.014 -0.011 0.094 07/27/15 Blueberries -0.018 0.017 0.005. 0.007 0.010 0.014 -0.002 0.008 0.027 0.060 10/20/15 Eggplant -0.002 0.020 0.003* 0.008 0.000 0.015 0.002 0.008 -0.032 0.073 10/20/15 Apples -0.006 0.023 0.003 0.010 0.005 0.017 -0.006 0.011 0.014 0.088 COLLECTION DATE , ____ }YE~----- Cs-134 Cs-137 Ba-140 La-140 Ce-141 (+/-) (+/-) (+/-) (+/-) (+/-) 07/27/15 Greens -0.001 0.012 -0.002 0.011 -0.021 0.071 0.022 0.022 0.015 0.021 07/27/15 Blueberries -0.009 0.007 -0.002 0.006 0.013 0.049 -0.014 0.016 -0.005 0.011 10/20/15 Eggplant -0.005 0.008 -0.002 0.009 0.020 0.036 0.007 0.012 0.001 0.015 10/20/15 Apples -0.002 0.011 0.004 0.010 0.047 0.044 0.000 0.013 0.016 0.015 3-19 Fe-59 Co-60 (+/-) (+/-) -0.022 0.027 -0.002 0.009 -0.005 0.015 -0.001 0.007 0.000 0.016 -0.005 0.008 -0.003 0.021 0.002 0.007 Sb-125 1-131 (+/-) (+/-) 0.012 0.028 -0.003 0.034 -0.014 0.020 0.000 0.023 0.004 0.021 -0.007 O.o15 0.006 0.027 -0.012 0.018 Ce-144 Ac-228 (+/-) (+/-) -0.039 0.076 -0.001 0.037 -0.031 0.039 0.015 0.028 0.023 0.056 -0.005 0.032 0.067 0.062 0.027 0.042

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 Be-7

-------T+i-r--

0.808 0.207 0.959 0.311 Zn-65

----------r+i-i ___

-0.026 0.031 0.001 0.059 Cs-134

----------r+,:y---

0.002 0.011 0.014 0.026 Be-7

----------r+i-r--

o.485 o.183 0.634 0.449 Zn-65

----------r+i-r--

-0.045 0.027 0.011 0.047 Cs-134

----------r+i:r--

0.000 0.012 -0.001 0.022 Annual Radiological Environmental Operating Report 2015 K-40

Fi-r-*

4.064 0.410 4.127 0.698 Nb-95

z.i7-r--*

-0.003 0.013 0.019 0.025 Cs-137

Fi-r--*

0.010 0.013 0.010 0.024 K-40

Fi-r--*

3.584 0.374 7.607 1.042 Nb-95

Fi-r--*

-0.005 0.012 -0.007 0.020 Cs-137

Fi-r--*

0.008 0.012 0.004 0.019 TABLE 9 BROADLEAF VEGETATION (pCi/g wet wt.) LOCATION 1 Cr-51

Fi:,---*

-0.019 0.126 -0.153 0.211 Zr-95

(+i:,---*

-0.021 0.022 0.015 0.036 Ba-140

(+i:,---*

-0.031 0.077 0.056 0.115 Mn-54

(+i:;--*

-0.004 0.012 0.021 0.020 Ru-103

**1+i=r-*

0.000 0.014 -0.008 0.023 La-140

(+i=r-*

0.003 0.019 -0.019 0.028 LOCATION 10 Cr-51

(+i=i---*

-0.009 0.115 -0.165 0.194 Zr-95

Fi:,---*

-0.005 0.020 -0.011 0.039 Ba-140

Fi:,---*

0.043 0.077 -0.046 0.080 Mn-54

(+i:;--*

0.015 0.011 0.002 0.018 Ru-103

(+i=r--

0.001 0.013 0.007 0.020 La-140

(+i=r--

0.007 0.016 -0.002 0.021 3-20 Co-58

----------Fi:r--

-0.003 0.011 -0.005 0.024 Ru-106

cn:r--

0.004 0.108 -0.005 0.217 Ce-141

----------c+t:r--

0.025 0.022 -0.018 0.039 Co-58

----------r+i:r--

-0.008 0.011 -0.011 0.017 Ru-106

----------cn:r--

-0.016 0.101 0.005 0.181 Ce-141

----------cn:r--

-0.015 0.022 0.022 0.038 Fe-59 Co*60

----------r+i-i __ _ *----------z.i7-r-0.019 0.026 o.01 o 0.012

-0.004 0.047 0.000 0.022 Sb-125 1-131

----------r+,:r--
----------z.i7-r--*

0.006 0.033 0.027 0.032 0.063 0.069 -0.031 0.039 Ce-144 Ac-228

----------r+,:r--
----------r+i-r--

-0.055 0.072 0.057 0.050 -0.018 0.174 0.145 0.134 Fe-59 Co-60

----------Fi-r--
----------Fi-) __ _

-0.006 0.024 -0.004 0.009 0.011 0.045 0.001 0.016 Sb-125 1-131

----------r+,:r--
----------r+i-r--

0.006 0.031 0.016 0.032 -0.044 0.057 -0.003 0.035 Ce-144 Ac-228

----------r+i-r--
----------F-r--

0.028 0.082 0.107 0.051 -0.010 0.146 -0.020 0.080

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 Be-7

--------Fr.r*-

0.604 0.258 0.826 0.288 Zn-65

----------r+r.r*-

-0.048 0.031 0.022 0.040 Cs-134

----------r+r.r*-

-0.008 0.016 -0.007 0.022 Be-7

----------r+r.r*-

1.021 0.193 1.042 0.290 Zn-65

----------wr--

-0.025 0.026 -0.040 0.038 Cs-134

----------r+r.r*-

-0.010 0.011 -0.032 0.022 Annual Radiological Environmental Operating Report 2015 K-40

Fi-r--*

2.840 0.398 3.430 0.699 Nb-95

z.i7-r--*

0.006 0.013 0.000 0.021 Cs-137

Fi-r--*

0.013 0.013 0.003 0.020 K-40

(-i7-r--*

3.805 0.372 3.261 0.598 Nb-95

Fi-r--*

-0.007 0.010 0.006 0.019 Cs-137

Fi-r--*

0.009 0.010 0.021 0.020 TABLE 9 BROADLEAF VEGETATION (pCi/g wet wt.) LOCATION 17 Cr-51 Mn-54

Fi:,---* ----------Ti*rr**

-0.055 0.140 -0.002 0.013 -0.068 0.196 -0.011 0.017 Zr-95 Ru-103

(+iT-* ----------,+ri*--

-0.002 0.023 -0.007 0.013 0.000 0.033 0.010 0.020 Ba-140 La-140

(+i:,---*

(+7y---

-0:042 0.083 -0.008 0.023 -0.052 0.096 0.009 0.033 LOCATION 26 (control, background location) Cr-51

(+i:,---*

-0.004 0.100 0.061 0.177 Zr-95

FiT-*

-0.003 0.017 0.002 0.035 Ba-140

Fi:,---*

0.020 0.061 -0.019 0.085 Mn-54

(+i=r--*

-0.009 0.010 -0.001 0.018 Ru-103

,+i=r*--

0.008 0.011 0.000 0.019 La-140

(+i=-r-*

0.005 0.017 -0.007 0.026 3-21 Co-58

----------(+t:r--

-0.009 0.014 -0.005 0.015 Ru-106

----------(+t:r--

-0.027 0.111 0.026 0.143 Ce-141

----------(+t:r--

0.010 0.023 -0.013 0.033 Co-58

---------T+i=;---

0.007 0.010 -0.008 0.016 Ru-106

----------(+t=r--

-0.033 0.087 -0.053 0.157 Ce-141

----------Ft:r--

-0.016 0.019 0.008 0.032 Fe-59

----------,+,:r--

0.000 0.029 0.034 0.048 Sb-125

----------[+1:r*-

0.008 0.037 -0.059 0.052 Ce-144

----------r+q*--

-0.047 0.086 -0.074 0.130 Fe-59

----------r;r.r--

0.011 0.023 -0.020 0.040 Sb-125

----------r+1:r*-

0.013 0.027 0.023 0.046 Ce-144

----------r+rr*--

0.015 0.063 0.009 0.127 Co-60

----------z.;r.r*-*

0.009 0.012 -0.006 0.024 1-131

----------(+i-r--

-0.017 0.038 0.008 0.034 Ac-228

----------r+r.r*-

0.026 0.049 0.063 0.076 Co-60

----------r+r.r--

0.004 0.011 0.010 0.019 1-131

----------z.;r.r*-

0.001 0.028 -0.025 0.033 Ac-228

----------r+r.r*-

0.022 0.040 0.007 0.093

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION

- .. !?~!~----*

01/26/15 02/24/15 03/31/15 04/28115 05/26/15 06130/15 07128115 08/25115 09/29/15 10/27115 11/24115 12/29/15 COLLECTION .**. !?~!~----* 01126/15 02/24115 03131115 04/28115 05126/15 06130/15 07/28/15 08125115 09/29115 10127/15 11124/15 12129/15 COLLECTION DATE 01/26115 02124115 03/31/15 04/28115 05126115 06130/15 07/28115 08125/15 09129115 10127/15 11124/15 12129/15 H-3

**r+r.r**--

375 135 92 117 319 134 176 121 645 154 622 156 437 188 546 136 433 243 1190 323 205 123 157 125 Co-60

**r+r.r**--

-1.4 3.2 1.4 4.2 -0.5 1.6 -1.1 3.7 0.6 3.9 1.7 3.2 -2.3 3.3 -0.1 4.2 0.1 4.1 4.0 4.9 3.5 3.3 3.2 3.9 1-131

**r+r.r**--

-2.8 4.6 5.8 6.6 4.7 8.3 4.5 6.9 -0.6 8.3 2.5 7.1 0.2 5.7 -1.3 6.1 0.9 7.9 -2.7 7.2 -0.9 5.4 -0.1 7.9 Be-7

-----------(+ri*---

-7.2 22.1 8.5 32.3 5.0 15.1 0.5 29.3 23.8 36.8 17.3 29.8 -0.9 26.8 -7.1 32.2 0.6 39:6 -28.5 42.0 -1.1 26.1 11.4 39.8 Zn-65

-----------Fi ___ _

-5.8 5.6 -3.7 10.4 -5.1 3.5 2.6 7.0 0.9 8.2 0.1 7.7 8.0 8.3 -11.3 9.8 -9.4 10.9 -10.5 12.5 4.6 8.4 -0.8 9.9 Cs-134

-----------(+i~i""""

-1.1 2.6 -4.8 3.7 -0.1 1.7 0.0 3.4 -5.4 4.4 1.4 3.5 3.7 3.4 -1.3 4.3 -4.4 5.2 0.3 4.7 -2.0 3.7 -4.6 4.6 Annual Radiological Environmental Operating Report 2015 K-40

**r+,:;-**-*

245 67 329 92 277 46 448 225 181 123 273 79 311 77 273 93 308 110 238 115 371 102 411 110 Nb-95

**r.;,:j*---*

0.9 2.5 -0.1 4.6 -0.3 1.7 TABLE 10 SEAWATER (pCi/I) LOCATION 32 Cr-51

-----------(+i~-----

-18.0 23.7 -5.1 31.9 8.0 21.1 28.1 32.5 -18.6 42.6 4.4 31.0 18.2 27.9 5.7 33.6 -7.6 41.4 -10.6 46.5 -30.1 31.0 -1.1 45.5 Zr-95

-----------(+i~-----

5.7 3.7 Note 2.4 4.7 -2.6 7.3 3.0 3.4 -4.5 6.2 -1.0 4.7 0.5 3.4 17.2 4.2 Note -0.6 3.8 1.9 3.5 -3.8 4.8 -1.3 3.4 3.1 4.5 -4.6 7.2 -0.8 6.0 1.5 5.2 3.8 7.6 0.3 7.5 -2.1 8.1 -2.1 5.1 1.6 8.3 Mn-54

**r+,:;*---*

0.4 2.3 -0.9 4.4 0.1 1.7 0.2 3.3 1.5 4.4 -0.5 3.2 -1.5 3.0 -0.1 3.2 1.5 4.8 -0.2 4.8 1.7 2.8 -5.2 4.1 Ru-103

**r+,:;**--*

-1.0 2.8 1.8 4.3 -0.9 2.4 1.9 3.6 -2.2 5.1 3.8 3.8 1.1 3.2 -0.3 3.7 -0.2 5.2 1.4 4.8 -0.9 3.8 -0.6 4.8 Co-58

(+i-i"""""

0.4 2.7 -3.1 3.9 -1.0 1.8 -1.4 3.5 -2.9 4.2 -0.5 3.2 -3.0 3.5 1.6 3.9 -2.5 5.1 1.2 4.9 -3.8 3.7 -1.2 4.4 Ru-106

(+i-i"""""

0.0 23.8 -12:7 38.6 -7.1 14.2 19.0 31.5 -2.9 38.3 10.7 28.4 -0.3 25.3 -7.6 33.9 -20.6 44.2 10.2 40.7 -0.2 35.9 9.6 43.4 Fe-59

----------*-c+i:;**--*

2.5 5.4 5.8 9.5 -0.8 4.0 0.6 6.8 -1.4 8.5 -3.6 6.3 -1.7 6.4 -0.9 9.2 -2.6 11.0 3.0 9.1 -4.9 6.8 -1.3 10.3 Sb-125

-----------*c+i:;**--*

-1.8 6.8 -3.3 9.6 0.3 4.7 4.0 9.3 -3.9 11.8 4.2 8.6 5.0 8.7 -1.6 11.4 -11.5 13.5 4.8 13.3 11.0 10.1 8.6 10.5 Note: Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. Cs-137

**r+,:i*---*

-0.9 2.8 -0.6 3.8 0.1 1.6

o.7 3.9 0.9 4.7 0.5 3.5 0.1 3.6 3.0 3.8 0.7 4.6

-0.1 4.7 -3.0 3.6 -2.8 5.0 Ba-140

-----------(+i~-----

-7.1 12.0 3.0 20.1 -8.5 14.3 13.2 19.9 3.6 23.0 -20.1 19.5 -0.9 16.0 2.5 14.7 3.0 22.1 -4.3 19.5 5.7 16.6 20.6 22.6 3-22 La-140

**c-:;,:;*---*

3.1 3.9 2.3 7.6 -1.9 4.3 -2.3 4.8 2.0 5.2 1.6 5.9 4.8 5.2 0.1 5.1 2.5 6.4 3.2 7.4 2.0 5.7 1.6 7.3 Ac-228

Fi-i" ___ _

-4.3 9.7 -5.0 15.9 -2.8 6.5 -79.5 30.5 2.9 15.7 4.0 12.2 1.6 12.4 -13.5 14.4 0.1 14.9 10.3 17.4 10.7 12.3 -2.2 16.3

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 03/16/15 06/09/15 09/15/15 12/08/15 COLLECTION DATE 03/16/15 06/09/15 09/15/15 12/08/15 COLLECTION DATE 03/16/15 06/09/15 09/15/15 12/08/15 H-3 (+/-) -62 107 45 118 54 159 91 118 Co-60

------------r;i-r---*

1.3 3.6 2.7 3.1 1.1 4.9 3.9 4.2 1-131

(+i-) _____

7.3 7.8 -3.3 7.2 -5.6 8.6 0.1 8.4 Be-7

-----------(+i:y----

4.7 30.1 1.8 27.5 -2.6 40.5 11.3 46.2 Zn-65

-----------(+i:,-----

-8.5 7.6 0.1 6.8 -12.6 10.3 1.7 11.2 Cs-134

-----------(+iT ____

-1.0 3.3 -2.6 2.9 -7.5 5.8 -0.7 5.4 Annual Radiological Environmental Operating Report 2015 TABLE 10 SEAWATER (pCi/I) LOCATION 37 (control, background location) K-40 Cr-51

[+1:)----*

-----------(+i:,-----

203 98 30.95 35.23 314 80 -3.13 31.22 242 120 27.20 46.87 370 118 38.93 47.98 Nb-95 Zr-95

(+,:) _____

-----------(+i:,-----

-1.4 3.8 2.9 6.7 -0.6 3.2 -3.5 5.6 1.3 5.0 1.0 8.5 2.6 4.5 -2.8 7.7 Cs-137 Ba-140

[+1:i----*

-----------(+i:,-----

2.4 3.6 -2.2 17.9 -1.1 3.0 3.5 18.3 -0.9 5.3 -28.8 20.9 0.7 5.5 8.4 22.0 3-23 Mn-54 (+/-) 0.5 3.5 -0.8 2.9 0.0 4.5 1.1 5.6 Ru-103 (+/-) -4.3 4.5 -2.4 3.6 -1.8 5.1 -0.1 5.0 La-140

r+1T ____

1.6 6.8 1.3 5.0 -4.4 6.6 -5.4 10.2 Co-58 Fe-59

-----------(:;:i_r----
-----------T+i:;----*

-2.6 3.3 2.3 8.4 1.1 3.0 0.2 6.1 0.9 4.7 6.0 8.2 -2.5 5.2 -5.9 9.4 Ru-106 Sb-125

-----------(:;:i_r----
-----------T+i:;----*

17.2 32.5 -5.9 10.2 -20.0 27.0 -1.3 7.6 -6.3 39.6 -7.3 13.4 -25.1 42.1 -6.5 12.7 Ac-228

-----------(:;:i-i _____

5.8 14.4 -4.1 11.2 -20.2 19.5 -12.1 19.4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 11 BOTIOM SEDIMENT (pCi/g dry wt.) COLLECTION .k9..gAILQt!. ____ !?A!S..... Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

T+r.r--*

'[+1:;---*

.. (+1:)*--*

(+1:)"'"

(+i-)""

T+1:r--*

31 01/16/15 0.095 0.235 14.16 0.98 0.087 0.283 0.011 0.027. 0.010 0.025 0.001 0.048 31 11/20/15 -0.231 0.308 14.17 1.34 -0.102 0.329 0.007 0.038 -0.013 0.034 -0.113 0.073 32 06/24/15 0.090 0.327 15.79 1.42 -0.177 0.360 0.025 0.040 0.030 0.039 -0.117 0.093 32 12/10/15 -0.131 0.340 13.06 1.84 0.113 0.369 0.003 0.033 0.007 0.029 -0.027 0.053 33 05/13/15 0.248 0.364 16.55 1.34 0.115 0.456 0.011 0.042 -0.013 0.043 0.075 0.083 33 07/23/15 0.320 0.324 16.14 1.15 -0.031 0.394 0.010 0.030 0.012 0.035 0.037 0.084 34 03/12/15 -0.115 0.144 14.22 0.71 0.019 0.146 -0.002 0.016 0.000 0.016 -0.029 0.041 34 07/23/15 -0.105 0.214 19.94 1.24 -0.179 0.246 -0.010 0.024 0.011 0.026 -0.019 0.069 37 01/16/15 0.009 0.141 12.45 0.92 -0.213 0.165 -0.004 0.016 -0.001 O.Q18 0.002 0.049 37 11/20/15 0.021 0.217 18.05 1.25 -0.054 0.216 0.018 0.025 -0.008 0.025 0.016 0.067 (37 is control, background location) COLLECTION .k9..gAILQt-J..

- .* !?A!L..

Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

<'+,:r*..

(-.;:,:;-*--

{+,:;----

(+,:)" -----------F,:r*..

*T+i:i*--*

31 01/16/15 -0.001 0.022 -0.067 0.053 0.011 0.028 0.007 0.052 -0.004 0.030 0.210 0.236 31 11/20/15 0.028 0.036 0.026 0.084 -0.032 0.042 0.034 0.076 0.034 0.041 -0.037 0.336 32 06/24/15 0.001 0.034 -0.062 0.117 0.068 0.046 -0.028 0.074 0.015 0.043 0.077 0.306 32 12/10/15 -0.007 0.034 -0.004 0.070 -0.013 0.034 0.019 0.068 0.015 0.036 0.010 0.256 33 05/13/15 -0.007 0.038 -0.130 0.108 0.035 0.043 0.043 0.075 -0.021 0.046 -0.346 0.369 33 07/23/15 0.022 0.031 -0.085 0.080 -0.009 0.041 0.010 0.065 o.o:i2 0.041 0.022 0.278 34 03/12/15 -0.001 0.016 -0.049 0.046 O.o18 0.017 0.008 0.029 0.006 O.Q18 -0.026 0.143 34 07/23/15 -0.014 0.025 -0.062 0.075 -0.011 0.026 -0.028 0.045 0.017 0.025 0.121 0.205 37 01/16/15 0.004 0.019 -0.010 0.052 -0.006 0.020 0.004 0.036 0.002 0.020 -0.073 0.152 37 11/20/15 -0.002 0.029 -0.036 0.071 0.013 0.029 0.007 0.049 -0.019 0.027 -0.209 0.231 COLLECTION .k9..gAILQt!. DATE

~..'!:J.1..'!.~L...

Sb-125 1-131 Cs-134 Cs-137 Ac-228 (+/-)

(+,:;---*

(+,:;--..

c+,:r*..

'(+1:)" -----------F,:r*--

31 01/16/15 0.000 0.026 -0.020 0.071 -0.016 0.077 0.028 0.027 0.017 0.027 0.311 0.392 31 11/20/15 0.009 0.038 -0.024 0.092 0.062 0.096 -0.003 0.040 -0.026 0.042 2.164 0.381 Note 32 06/24/15 -0.054 0.036 -0.004 0.090 0.057 0.104 0.002 0.039 0.010 0.041 1.211 0.300 Note 32 12/10/15 0.016 0.025 -0.016 0.086 0.009 0.100 -0.018 0.031 0.025 0.040 1.010 0.379 Note 33 05/13/15 -0.045 0.039 -0.003 0.112 -0.042 0.118 0.011 0.042 -0.018 0.044 0.130 0.366 33 07/23/15 0.002 0.030 0.022 0.087 -0.013 0.165 0.045 0.035 -0.042 0.033 0.605 0.215 Note 'Note: Extra counts detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. 34 03/12/15 0.000 0.016 -0.003 0.041 -0.009 0.047 -0.008 0.017 0.002 O.Q18 0.181 0.126 34 07/23/15 -0.005 0.022 -0.024 0.051 -0.057 0.101 -0.008 0.022 -0.020 0.025 0.012 0.162 37 01/16/15 -0.019 O.D15 -0.041 0.038 0.038 0.042 -0.003 0.019 0.016 0.017 0.027 0.127 37 11/20/15 0.000 0.021 0.007 0.064 -0.036 0.055 O.D15 0.023 0.006 0.022 0.146 0.134 3-24

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 COLLECTION LOCATION DATE 29 01/15/15 29 29 29 32 32 32 32 35 35 35 35 36 36 36 36 90 90 90 90 05/12/15 07/22/15 10/05/15 01/15/15 05/12/15 07/22/15 11/20/15 01/15/15 05/12/15 07/22/15 10/05/15 01/16/15 06/12/15 09/10/15 11/20/15 03/12/15 05/13/15 07/23/15 12/04/15 TABLE 12 AQUATIC FLORA-FUCUS (pCi/g wet wt.) (all samples are extra, not required by the REMODCM) Be-7 (+/-) 0.2670 0.1124 K-40 (+/-) 6.0720 0.4164 0.1966 0.0612 6.0290 0.2142 0.0643 0.0905 6.8460 0.4335 0.0667 0.0875 6.0680 0.6264 0.1980 0.1* 178 8.3540 0.3809 0.0234 0.0858 7.1700 0.4172 0.0881 0.0621 6.3020 0.3398 0.0319 0.1159 9.4520 0.6652 0.2375 0.1582 7.7990 0.5258 0.1387 0.0832 Note 1 6.5640 0.3650 0.0942 0.0954 6.8390 0.3896 0.0709 0.1506 7.8080 0.8566 Cr-51 (+/-) -0.0073 0.0936 0.0115 0.0494 -0.0694 0.1072 0.0064 0.1127 -0.0712 0.0793 -0.0224 0.0892 -0.0053 0.0705 0.0407 0.1118 -0.0154 0.0387 -0.0562 0.0915 -0.0368 0.0912 0.0654 0.1500 Note 1: Result is less than minimum detectable activity (MDA) of 0.149 pCi/g. 0.1634 0.1287 6.1650 0.5130 0.0931 0.1153 0.0651 0.0896 6.0150 0.4647 -0.0282 0.0964 0.0623 0.0851 7.1020 0.4150 0.0014 0.0939 0.1802 0.1193 Note 2 7.1070 0.6037 -0.0017 0.1067 Note 2: Result is less than minimum detectable activity (MDA) of 0.224 pCi/g. 0.2663 0.1021 6.1880 0.2976 -0.0020 0.0665 0.1291 0.0993 -0.0139 0.0526 0.0713 0.1144 6.6930 0.3477 7.0070 0.3016 8.6210 0.5996 0.0049 0.0830 -0.0286 0.0583 0.0834 0.1103 3-25 Mn-54 (+/-) -0.0048 0.0098 -0.0003 0.0044 -0.0046 0.0093 0.0010 0.0122 0.0010 0.0078 -0.0039 0.0093 -0.0033 0.0069 0.0052 0.0124 0.0005 0.0038 0.0002 0.0087 0.0087 0.0091 0.0062 0.0147 -0.0057 0.0129 0.0033 0.0100 0.0014 0.0086 0.0020 0.0131 0.0021 0.0058 0.0079 0.0081 -0.0006 0.0060 -0.0009 0.0115 Co-58 (+/-) -0.0088 0.0103 0.0006 0.0047 0.0003 0.0102 0.0014 0.0123 -0.0029 0.0079 0.0056 0.0095 0.0023 0.0075 0.0024 0.0124 -0.0002 0.0036 -0.0082 0.0089 -0.0040 0.0101 -0.0089 0.0178 0.0069 0.0136 -0.0042 0.0108 -0.0011 0.0089 -0.0002 0.0135 -0.0035 0.0061 0.0016 0.0092 0.0032 0.0065 0.0149 0.0126 Fe-59 (+/-) 0.0042 0.0250 -0.0024 0.0115 0.0038 0.0258 0.0000 0.0351 -0.0020 0.0202 0.0084 0.0215 0.0017 0.0183 -0.0053 0.0332 -0.0025 0.0112 0.0033 0.0215 0.0129 0.0228 -0.0002 0.0399 -0.0111 0.0338 -0.0257 0.0262 0.0126 0.0230 0.0086 0.0340 0.0174 0.0155 -0.0016 0.0199 -0.0029 0.0167 -0.0197 0.0288

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 12 AQUATIC FLORA-FUCUS (pCi/g wet wt.) (all samples are extra, not required by the REMODCM) COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 29 01/15/15 0.0064 0.0083 -0.0107 0.0251 0.0007 0.0102 -0.0161 0.0186 -0.0021 0.0104 -0.0836 0.0847 29 05/12/15 0.0017 0.0049 -0.0162 0.0120 0.0037 0.0050 0.0090 0.0089 0.0025 0.0051 -0.0059 0.0410 29 07/22/15 0.0085 0.0103 -0.0294 0.0259 0.0065 0.0105 0.0229 0.0195 0.0044 0.0107 -0.0424 0.0891 29 10/05/15 0.0051 0.0141 -0.0206 0.0348 -0.0027 0.0127 -0.0018 0.0231 0.0014 0.0133 -0.0307 0.1233 32 01/15/15 0.0010 0.0094 -0.0137 0.0183 0.0047 0.0084 0.0144 0.0144 -0.0090 0.0083 -0.0340 0.0702 32 05/12/15 -0.0014 0.0090 -0.0032 0.0234 -0.0002 0.0096 0.0030 0.0165 -0.0004 0.0096 0.0250 0.0756 32 07/22/15 0.0026 0.0076 -0.0145 0.0186 0.0035 0.0067 -0.0123 0.0112 -0.0019 0.0079 0.0387 0.0565 32 11/20/15 -0.0025 0.0143 -0.0249 0.0299 0.0132 0.0120 0.0153 0.0191 0.0007 0.0128 0.0693 0.1101 35 01/15/15 -0.0078 0.0054 0.0107 0.0100 0.0018 0.0046 0.0025 0.0092 0.0020 0.0044 0.0051 0.0326 35 05/12/15 0.0039 0.0082 -0.0114 0.0207 0.0034 0.0098 0.0011 0.0165 0.0030 0.0099 0.0029 0.0782 35 07/22/15 0.0071 0.0098 -0.0260 0.0206 0.0090 0.0098 0.0024 0.0166 0.0038 0.0096 0.0289 0.0764 35 10/05/15 0.0107 0.0191 -0.0275 0.0482 0.0084 0.0172 0.0190 0.0328 0.0079 0.0166 0.0488 0.1298 36 01/16/15 -0.0024 0.0118 -0.0463 0.0316 -0.0008 0.0136 0.0051 0.0238 -0.0013 0.0130 -0.0150 0.1086 36 06/12/15 0.0018 0.0104 -0.0285 0.0240 0.0051 0.0108 -0.0013 0.0193 0.0061 0.0112 0.0024 0.0824 36 09/10/15 -0.0014 0.0088 -0.0004 0.0272 0.0024 0.0106 -0.0175 0.0169 0.0028 0.0095 -0.0184 0.0732 36 11/20/15 0.0104 0.0140 -0.0316 0.0285 0.0037 0.0149 -0.0316 0.0266 -0.0056 0.0140 -0.0437 0.1158 90 03/12/15 0.0054 0.0057 -0.0215 0.0160 -0.0014 0.0068 -0.0011 0.0118 -0.0017 0.0067 0.0431 0.0564 90 05/13/15 -0.0030 0.0084 0.0066 0.0209 0.0004 0.0087 0.0131 0.0151 -0.0031 0.0085 0.0314 0.0708 90 07/23/15 0.0031 0.0061 -0.0264 0.0162 -0.0062 0.0066 -0.0023 0.0115 0.0027 0.0066 0.0494 0.0526 90 12/04/15 0.0079 0.0137 -0.0276 0.0289 -0.0044 0.0130 0.0104 0.0249 -0.0089 0.0131 -0.0258 0.0986 3-26

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Ag-110M (+/-) 29 01/15/15 -0.0030 0.0085 29 05/12/15 0.0013 0.0045 29 07/22/15 -0.0038 0.0095 29 10/05/15 0.0025 0.0135 32 01/15/15 0.0115 0.0080 32 05/12/15 -0.0034 0.0077 32 07/22/15 -0.0075 0.0063 32 11/20/15 0.0004 0.0113 35 01/15/15 -0.0028 0.0042 35 05/12/15 -0.0026 0.0090 35 07/22/15 -0.0015 0.0082 35 10/05/15 -0.0100 0.0160 36 01/16/15 0.0001 0.0109 36 06/12/15 -0.0006 0.0095 36 09/10/15 -0.0046 0.0082 36 11/20/15 -0.0007 0.0138 90 03/12/15 -0.0077 0.0057 90 05/13/15 -0.0017 0.0078 90 07/23/15 0.0024 0.0054 90 12/04/15 -0.0082 0.0107 Annual Radiological Environmental Operating Report 2015 TABLE 12 AQUATIC FLORA-FUCUS (pCi/g wet wt.) (all samples are extra, not required by the REMODCM) Sb-125 1-131 Cs-134 (+/-) (+/-) (+/-) 0.0015 0.0215 0.0237 0.0283 -0.0036 0.0099 0.0004 0.0120 0.0047 0.0134 -0.0113 0.0047 0.0342 0.0236 0.0032 0.0332 -0.0193 0.0105 -0.0030 0.0322 -0.0214 0.0229 0.0016 0.0160 -0.0054 0.0215 0.0257 0.0228 -0.0092 0.0075 0.0010 0.0233 0.0070 0.0279 -0.0007 O.Q093 0.0017 0.0167 -0.0089 0.0218 -0.0065 0.0069 -0.0209 0.0344 0.0196 0.0343 -0.0100 0.0122 0.0051 0.0110 -0.0001 0.0119 -0.0003 0.0031 -0.0076 0.0232 0.0014 0.0271 0.0028 0.0089 0.0026 0.0233 -0.0034 0.0281 -0.0188 0.0088 0.0034 0.0432 -0.0096 0.0260 -0.0186 0.0194 -0.0028. 0.0301 0.0173 0.0308 -0.0058 0.0133 0.0044 0.0208 0.0189 0.0341 -0.0104 0.0107 -0.0023 0.0252 -0.0043 0.0205 0.0071 0.0084 -0.0041 0.0324 0.0273 0.0275 0.0017 0.0107 0.0071 0.0165 0.0109 0.0195 -0.0025 0.0063 -0.0193 0.0202 0.0044 0.0212 -0.0034 0.0090 0.0027 0.0148 0.0222 0.0186 0.0011 0.0063 -0.0158 0.0269 0.0055 0.0286 0.0049 0.0137 Cs-137 Ac-228 (+/-) (+/-) 0.0015 0.0093 0.0387 0.0683 0.0026 0.0048 0.0978 0.0242 0.0043 0.0099 0.1282 0.0574 -0.0126 0.0151 0.1416 0.0633 -0.0154 0.0085 0.0751 0.0549 0.0016 0.0084 0.0719 0.0391 Note 1 0.0025 0.0065 0.0326 0.0424 0.0004 0.0129 0.0797 0.0800 0.0003 0.0044 0.1261 0.0750 Note2 0.0035 0.0094 0.0078 0.0816 0.0094 0.0087 0.1151 0.0623 0.0052 0.0160 -0.0186 0.0695 -0.0054 0.0125 0.0802 0.0665 -0.0016 0.0100 0.0989 0.0483 0.0075 0.0092 0.0185 0.0383 -0.0030 0.0140 0.0898 0.0573 Note 1 0.0048 0.0060 0.0552 0.0379 0.0020 0.0083 0.0615 0.0472 0.0007 0.0059 0.0902 0.0479 0.0096 0.0118 0.0840 0.0768 Note 1: Result for Ac-228 was less than Minimum Detectable Activity (MDA) Note 2: Extra counts detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. 3-27

Dominion Nuclear Connecticut, Inc. Millstone Powet Station COLLECTION LOCATION DATE 29 07/28/15 29 32 32 35 35 35 10/06/15 03/23/15 04/07/15 05/20/15 07/14/15 10/06/15 COLLECTION Be-7

(+iT*-*

-0.057 0.106 -0.093 0.276 -0.064 0.075 -0.011 0.108 -0.155 0.171 0.000 0.027 0.022 0.281 LOCATION DATE Co-60 (+I-) 29 07/28/15 -0.005 0.012 29 32 32 35 35 _35 10/06/15 03/23/15 04/07/15 05/20/15 07/14/15 10/06/15 COLLECTION LOCATION DATE 29 07/28/15 29 10/06/15 32 03/23/15 32 04/07/15 35 05/20/15 35 07/14/15 35 10/06/15 0.000 0.025 0.004 0.009 0.000 0.012 -0.009 0.020 0.002 0.002 -0.013 0.030 Ag-110M

,+ir-*

-0.002 0.011 -0.021 0.032 0.005 0.008 -0.001 0.011 0.009 O.Q18 0.001 0.002 -0.039 0.030 Annual Radiological Environmental Operating Report 2015 K-40

r;,:r**

4.512 0.378 3.792 0.946 5.314 0.325 5.002 0.406 4.466 0.573 4.020 0.151 3.775 0.759 Zn-65 (+I-) -0.042 0.028 -0.018 0.069 -0.027 0.018 -0.057 0.028 0.020 0.044 0.001 0.006 -0.001 0.082 Sb-125

f0=i __ _

0.020

0.031 0.012 0.079 0.012 0.019

-0.012 0.033 -0.017 0.054 0.003 0.006 0.053 0.100 TABLE 13 FISH (pCi/g wet wt) Cr-51

----------Fi-r***

-0.042 0.133 0.046 0.239 -0.108 0.095 -0.026 0.114 0.006 0.187 -0.014 0.039 -0.082 0.312 Nb-95 (+/-) 0.001 0.013 -0.001 0.033 0.002 0.009 0.017 0.012 0.010 0.020 0.002 0.003 0.043 0.033 1-131 (+/-) 0.010 0.045 0.021 0.045 0.013 0.052 0.007 0.025 0.004 0.039 -0.047 0.034 -0.009 0.053 3-28 Mn-54

c+t:i*--

0.003 0.011 0.002 0.029 0.002 0.008 -0.004 0.011 -0.002 0.021 0.000 0.002 -0.009 0.034 Zr-95

c+iT--

-0.015 0.022 -0.019 0.059 0.010 0.016 0.007 0.021 0.001 0.035 -0.001 0.005 -0.023 0.057 Cs-134

c+iT--

0.000 0.014 -0.004 0.036 -0.004 0.008 -0.043 0.012 0.007 0.024 -0.001 0.002 0.013 0.038 Co-58

----------Fi-r*-*

-0.010 0.012 0.000 0.032 0.001 0.009 -0.011 0.012 -0.014 0.021 -0.001 0.003 0.006 0.030 Ru-103 (+/-) -0.004 0.014 -0.012 0.032 -0.002 0.010 0.003 0.012 0.008 0.022 0.001 0.004 -0.030 0.035 Cs-137 (+/-) 0.007 0.012 0.001 0.033 0.000 0.008 0.002 0.012 -0.007 0.021 0.002 0.003 0.028 0.034 Fe-59

(+i'.:')""-

-0.020 0.028 0.021 0.070 0.005 0.021 -0.018 0.025 -0.011 0.042 0.001 0.007 -0.006 0.067 Ru-106 (+I-) -0.099 0.104 -0.. 154 0.256 -0.004 0.070 0.007 0.106 0.028 0.192 -0.017 0.022 0.186 0.289 Ac-228

(+i:-i---

-0. 050 0.047 -0.116 0.130 -0.033 0.047 0.008 0.061 0.035 0.080 -0.035 0.020 -0.014 0.115

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 14 OYSTERS (pCi/g wet wt.) COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

('.;.i~)---

,'.H~)---

(+/-) (+/-) (+/-) (+/-) 31 03/12/15 -0.087 0.199 2.310 0.607 0.000 0.224 0.006 0.027 -0.006 0.021 0.011 0.049 31 05/21/15 -0.090 0.114 2.515 0.493 -0.045 0.122 -0.002 0.015 0.008 0.016 0.018 0.033 31 08/10/15 0.167 0.480 2.269 0.983 -0.126 0.478 -0.027 0.051 0.010 0.053 0.049 0.112 31 12/07/15 0.045 0.190 2.226 0.841 0.001 0.186 -0.001 0.039 0.006 0.027 -0.036 0.060 32 03/04/15 -0.062 0.244 2.149 0.620 0.150 0.291 -0.012 0.027 0.031 0.027 -0.054 0.066 32 05/19/15 -0.385 0.431 2.034 0.840 -0.294 0.451 0.031 0.041 -0.015 0.044 -0.020 0.079 32 07/10/15 -0.090 0.142 2.406 0.441 -0.088 0.148 -0.003 0.017 -0.008 0.019 -0.029 0.032 32 12/09/15 -0.030 0.219 2.112 0.839 0.198 0.318 -0.060 0.046 -0.010 0.037 0.027 0.081 88 03/05/15 0.069 0.261 1.539 0.793 0.021 0.343 -0.002 0.029 -0.019 0.028 0.003 0.066 88 05/20/15 -0.048 0.154 1.891 0.470 -0.057 0.174 0.003 0.019 0.002 0.018 0.027 0.038 88 08/19/15 0.081 0.396 2.784 1.209 -0.277 0.320 -0.006 0.039 0.005 0.047 0.046 0.099 88 12/07/15 0.138 0.357 1.822 1.105 0.236 0.346 0.049 0.048 -0.030 0.042 0.008 0.081 37 03/10/15 0.029 0.194 2.583 0.612 0.166 0.242 -0.012 0.022 0.020 0.027 -0.015 0.055 37 05/29/15 0.023 0.292 2.247 0.917 0.030 0.378 -0.019 0.036 -0.011 0.041 -0.016 0.079 37 08/31/15 0.162 0.302 2.195 1.031 -0.326 0.311 0.033 0.043 -0.016 0.032 -0.063 0.072 37 01/15/16 0.095 0.215 1.025 0.656 -0.020 0.222 0.025 0.026 -0.017 0.026 -0.020 0.053 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-29

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Co-60 (+/-) 31 03/12/15 0.018 0.025 31 05/21/15 0.017 0.018 31 08/10/15 -0.016 0.056 31 12/07/15 0.020 0.046 32 03/04/15 0.020 0.029 32 05/19/15 0.004 0.042 32 07/10/15 0.002 0.016 32 12/09/15 -0.006 0.029 88 03/05/15 0.003 0.028 88 05/20/15 0.000 0.017 88 08/19/15 0.019 0.047 88 12/07/15 -0.002 0.043 37 03/10/15 -0.008 0.020 37 05/29/15 0.009 0.038 37 08/31/15 0.026 0.036 37 01/15/16 -0.006 0.024 Annual Radiological Environmental Operating Report 2015 TABLE 14 OYSTERS (pCi/g wet wt.) Zn-65 Nb-95 Zr-95 (+/-) (+/-) (+/-) -0.033 0.054 0.008 0.028 0.001 0.046 -0.039 0.037 -0.010 0.016 -0.011 0.026 -0.125 0.112 -0.007 0.050 -0.028 0.096 -0.061 0.065 0.012 0.036 -0.017 0.055 -0.030 0.054 0.020 0.035 0.036 0.055 -0.048 0.099 -0.003 0.044 -0.030 0.074 -0.031 0.042 0.015 0.019 -0.017 0.033 -0.027 0.071 0.022 0.047 -0.030 0.063 -0.061 0.062 -0.024 0.030 0.000 0.054 -0.073 0.043 0.004 0.019 0.019 0.034 -0.043 0.106 -0.031 0.039 -0.054 0.092 -0.026 0.097 -0.012 0.053 -0.003 0.098 -0.060 0.061 -0.008 0.023 0.043 0.050 -0.103 0.082 0.023 0.034 0.013 0.065 -0.133 0.094 0.005 0.036 -0.032 0.066 -0.062 0.059 0.035 0.024 0.007 0.045 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-30 Ru-103 Ru-106

,+i~r---

(+/-) 0.012 0.027 0.073 0.201 0.000 0.015 0.008 0.124 0.007 0.065 0.075 0.484 -0.024 0.034 0.022 0.287 -0.009 0.035 0.024 0.248 -0.019 0.049 0.149 0.467 -0.004 0.020 -0.216 0.158 -0.016 0.039 0.051 0.347 0.025 0.037 -0.153 0.287 0.008 0.020 -0.082 0.173 0.030 0.045 -0.370 0.321 -0.028 0.047 -0.290 0.410 -0.023 0.027 0.166 0.186 0.004 0.041 -0.144 0.294 0.016 0.041 -0.172 0.337 0.004 0.027 0.195 0.231

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Ag-110M

(+i:) ___

31 03/12/15 0.011 0.023 31 05/21/15 0.000 0.015 31 08/10/15 -0.001 0.048 31 12/07/15 0.014 0.031 32 03/04/15 -0.013 0.026 32 05/19/15 -0.005 0.048 32 07/10/15 0.017 0.017 32 12/09/15 -0.019 0.041 88 03/05/15 0.000 0.029 88 05/20/15 0.009 0.016 88 08/19/15 0.026 0.038 88 12/07/15 -0.016 0.042 37 03/10/15 -0.001 0.021 37 05/29/15 -0.023 0;029 37 08/31/15 0.012 0.037 37 01/15/16 -0.028 0.025 Annual Radiological Environmental Operating Report 2015 TABLE 14 OYSTERS (pCi/g wet wt.) Sb-125 1-131 Cs-134 (+/-) (+/-) (+/-) -0.016 0.053 0.023 0.080 -0.015 0.025 -0.009 0.038 -0.007 0.026 0.001 0.017 0.005 0.135 0.106 0.119 -0.002 0.069 0.000 0.079 -0.020 0.041 0.001 0.032 -0.028 0.073 -0.143 0.111 0.017 0.029 -0.071 0.121 -0.030 0.098 -0.073 0.050 0.011 0.044 0.004 0.042 0.014 0.019 -0.012 0.104 -0.002 0.068 0.027 0.042 0.048 0.077 0.063 0.120 0.004 0.032 0.039 0.050 0.000 0.034 0.005 0.021 0.025 0.134 0.021 0.070 -0.029 0.052 0.080 0.124 -0.096 0.085 -0.058 0.049 Cs-137 Ac-228

(+i:) ___

(+/-) 0.010 0.028 0.010 0.090 -0.002 0.017 0.023 0.067 0.038 0.055 0.149 0.178 -0.030 0.033 -0.185 0.162 0.011 0.027 0.101 0.103 -0.014 0.051 -0.067 0.187 -0.009 0.018 0.016 0.071 0.013 0.043 -0.043 0.148 -0.017 0.033 0.055 0.134 -0.005 0.019 0.097 0.091 -0.005 0.046 0.254 0.169 Note 0.005 0.045 0.036 0.153 Note: Ac-228 was not identified in sample. Counts in Ac-228 peak area were from naturally occuring Pb-214. 0.021 0.063 0.002 0.066 -0.031 0.026 . -0.014 0.024 -0.041 0.094 0.003 0.088 -0.054 0.103 -0.003 0.036 0.000 0.032 -0.092 0.139 0.040 0.101 0.027 0.074 -0.002 0.041 -0.008 0.040 0.031 0.139 0.055 0.064 0.007 0.053 0.008 0.028 0.015 0.025 -0.026 0.108 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-31

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE 29 03/12/15 29 06/09/15 29 07/24/15 29 10/07/15 38 38 38 06/11/15 08/04/15 10/27/15 COLLECTION LOCATION DATE 29 03/12/15 29 06/09/15 29 07/24/15 29 10/07/15 38 38 38 06/11/15 08/04/15 10/27/15 COLLECTION LOCATION DATE 29 03/12/15 29 06/09/15 29 07/24/15 29 10/07/15 38 38 38 06/11/15 08/04/15 10/27/15 Be-7 (+/-) 0.077 0.350 0.032 0.204 0.265 0.348 0.314 0.243 0.126 0.055 0.096 0.268 0.358 0.406 Co-60

-----------f+1:r*--

-o.01 o 0.036 0.009 0.027 0.005 0.031 -0.010 0.027 -0.002 0.011 0.009 0.027 0.043 0.055 ______ e-JJ:].~~1~1_ ____ _ (+/-) 0.003 0.037 0.027 0.023 0.010 0.034 -0.008 0.027 -0.001 -0.009 -0.010 0.028 0.043 0.054 Annual Radiological Environmental Operating Report 2015 K-40

-----------,+i-r*--

1.769 0.717 2.379 0.726 2.275 0.772 2.775 0.819 TABLE 15 CLAMS (pCi/g wet wt.) Cr-51 (+/-) -0.455 0.425 -0.033 0.229 0.021 0.380 0.173 0.245 2.144 2.205 1.992 0.604 0.058 0.297 0.431 0.544 0.951 -0.343 1.251 Note -0.088 Mn-54

(+i~----*

0.015 0.041 0.000 0.021 0.003 O.Q35 0.012 0.024 0.005 -0.002 -0.009 0.028 0.037 0.056 Note: Results is less than minimum detectable activity (MDA) of 2.67 pCi/g. Zn-65

-----------Fi-r*--

-o.034 0.066 0.000 0.056 -0.022 0.091 0.021 0.061 -0.052 0.072 -0.048 0.059 0.099 0.151 Sb-125 ( +/-) 0.063 0.100 -0.013 0.063 -0.050 0.084 -0.016 0.087 0.024 -O.Q38 -0.051 0.073 0.107 0.171 Nb-95

(:;:.i_y---*

0.041 0.039 0.021 0.025 0.028 0.042 O.Q15 0.031 0.001 -0.028 -0.013 0.029 0.044 0.053 1-131 (+/-) -0.048 0.121 -0.023 0.042 0.037 0.143 -0.083 0.050 0.144 0.042 0.015 3-32 0.120 0.152 0.100 Zr-95

(+i~----*

-0.001 0.063 -0.009 0.046 -0.049 0.066 0.016 0.052 0.007 -0.016 0.085 0.050 0.067 0.096 Cs-134 (+/-) -0.044 0.040 0.007 0.032 0.007 0.037 0.006 0.031 -0.023 -0.035 -0.043 0.030 0.043 0.065 Co-58

(+i~)----

0.025 0.035 -0.019 0.026 -0.023 0.034 -0.005 0.026 -0.001 0.015 0.001 Ru-103 0.033 0.051 0.059

(+i~f----

0.001 0.045 -0.017 0.025 0.004 0.045 -0.009 0.029 0.031 0.008 -0.010 0.033 0.051 0.055 Cs-137 ( +/-) -0.028 0.042 -0.010 0.026 0.036 0.036 -0.016 0.032 0.029 0.007 -0.001 0.028 0.039 0.056 Fe-59 (+/-) 0.016 0.065 0.005 0.054 0.012 0.070 -0.008 0.042 0.007 -0.045 -0.087 Ru-106 0.062 0.090 0.085

----------7+,:) ___ _

0.025 0.351 0.064 0.189 -0.070 0.344 -0.126 0.222 -0.085 -0.123 0.091 Ac-228 0.261 0.415 0.460 (+/-) 0.128 0.141 0.028 0.111 0.084 0.155 -0.046 0.117 0.079

0.018 0.144 0.109 0.159 0.220

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 COLLECTION LOCATION DATE 35 03/24/15 35 35 35 89 89 89 89 05/26/15 07/30/15 10/22/15 03/20/15 06/19/15 08/18/15 12/08/15 Be-7 (+/-) 0.228 0.320 -0.150 0.203 -0.046 -0.023 -0.341 -0.167 0.064 0.201 0.412 0.384 0.528 0.321 0.258 0.486 K-40 (+/-) 2.355 0.738 3.004 0.691 3.122 1.043 3.083 1.586 2.549 0.968 2.687 0.964 2.544 0.731 3.880 1.618 (89 is control, background location) COLLECTION LOCATION DATE 35 03/24/15 35 35 35 89 89 89 89 05/26/15 07/30/15 10/22/15 03/20/15 06/19/15 08/18/15 12/08/15 COLLECTION LOCATION DATE 35 03/24/15 35 35 35 89 89 89 89 05/26/15 07/30/15 10/22/15 03/20/15 06/19/15 08/18/15 12/08/15 Co-60 Zn-65

,+,:5*--* ------------r+i-r--*

0.008 0.032 -0.032 0.070 0.012 0.002 0.010 0.023 -0.010 -0.010 0.028 0.025 0.039 0.056 0.049 0.033 0.028 0.040 -0.050 -0.083 -0.067 -0.038 0.002 -0.056 -0.090 0.058 0.098 0.131 0.100 0.084 0.073 0.152 Ag-110M Sb-125

(+i-r--* ------------Fi-i*--*

-0.008 0.028 -0.010 0.075 0.009 0.029 -0.035 -0.021 0.000 -0.003 0.016 0.020 0.041 0.044 0.042 0.033 0.027 0.060 -0.014 0.044 0.001 -0.096 0.001 0.013 0.109 0.061 0.150 0.131 0.121 0.085 0.074 0.166 TABLE 16 LOBSTERS (pCi/g wet wt.) Cr-51 Mn-54 Co-58 Fe-59

r+i-r--* ------------1+,:r*-* ------------i+i-r--* ------------,+,:r*-*

-0.151 0.387 -0.004 0.032 -0.011 0.033 -0.009 0.075 -0.087 -0.235 0.089 0.149 0.005 -0.007 0.258 0.196 0.527 0.401 0.725 0.282 0.260 0.491 Nb-95 (+/-) 0.008 0.037 0.002 0.010 0.026 -0.041 0.003 0.004 0.044 1-131 0.025 0.045 0.052 0.046 0.042 0.029 0.061 (+/-) 0.254 0.203 0.027 -0.016 -0.020 -0.238 -0.025 0.014 0.039 3-33 0.052 0.160 0.067 0.481 0.083 0.049 0.091 0.018 -0.013 -0.026 0.000 0.009 0.003 0.013 0.021 O.D38 0.044 0.038 0.033 0.030 0:073 Zr-95 (+/-) 0.024 0.068 -0.028 .-0.022 0.073 -0.012 -0.002 0.007 0.099 0.048 0.091 0.073 0.079 0.068 0.050 0.130 Cs-134

,+,:r--*

-0.058 0.036 -0.009 -0.068 0.018 -0.032 0.007 -0.003 -0.006 0.030 0.056 0.049 0.045 0.032 0.035 0.070 -0.015 -0.022 -0.057 0.008 -0.022 -0.004 -0.007 0.029 0.051 0.051 0.044 0.037 0.029 0.059 Ru-103 (+/-) -0.003 0.042 0.012 0.027 0.027 -0.051 -0.001 0.011 -0.034 0.023 0.056 0.049 0.065 0.036 0.027 0.060 Cs-137 (+/-) 0.010 0.028 0.009 -0.039 -0.014 0.030 0.027 0.000 0.009 0.024 0.042 0.049 0.043 0.039 0.029 0.064 -0.015 0.089 0.013 0.090 -0.038 -0.004 0.023 0.054 0.100 0.080 0.106 0.088 0.055 0.149 Ru-106

,+i-r--*

0.152 0.290 -0.035 -0.030 0.068 -0.058 0.088 -0.141 -0.339 0.215 0.380 0.415 0.433 0.316 0.255 0.571 Ac-228

,.tt:r*-*

-0.015 0.112 -0.003 -0.162 0.042 -0.005 0.037 -0.159 0.019 0.096 0.211 0.251 0.142 0.124 0.094 0.233

Dominion Nuclear Connecticut, Inc. Millstone Power Station

4.

DISCUSSION OF RESULTS Annual Radiological Environmental Operating Report 2015 This section summarizes the results ofthe analyses on the REMP samples. The only case where station related radioactivity was detected was tritium (H-3) in seawater collected at the quarry discharge point. This was within the station boundary. The naturally occurring nuclides of Be-7, K-40, and Ac-228 were detected in numerous samples. Be-7 is from cosmic radiation. It was observed in air and broadleaf vegetation and in some fruits,, vegetable and fucus samples. K-40 and Ac-228 are two common terrestrial isotopes. K-40 was observed in almost every type of sample. Ac-228 results were variable; it was observed in some sediment and fucus samples. Cs-1.37 and Sr-90 from atmospheric nuclear weapons testing in the 1960's have been observed in the past. During 2015, Cs-137 was detected in soil samples. Sr-90 was not detected in 2015. 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 CaF2(Mn) glass bulb dosimeters were used for these measurements. In 1990, these were replaced by Harshaw CaF2(Mn) chips. In 2000, the CaF2(Mn) TLDs, were replaced with the CaS04(Tm) Panasonic model UD-804 ASx TLDs. Readings are recorded as uR/hr. The unit uR stands for 'micro-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. For gamma exposure a micro-roentgen is equivalent to a micro-rem, a measure of dose to man. The dosimeters are strategically placed at a number of onsite locations, as well as at inner and outer offsite 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 (73-75) 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 2006, three in 2007, three in 2009, three in 2010 and seven in 2015. None were loaded in 2008 or from 2011 to 2014. The exposure rate measurements at two of 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 73, 7.4 uR/hour at Location 74 and 6.7 uR/hour at Location 75). At Location 73 the readings have been lower since the fourth quarter of 2012, averaging 7.6 uR/hour. 4-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table 1 in Section 3.2 lists the exposure rate r:neasurements for all 44 monitored locations. These measurements demonstrate the general variations in background radiation between the various onsite and offsite locations and include gamma exposure from all sources of radioactivity. For example, the Weather Shack (Location 2), Millstone Unit 3 Discharge (Location 5), Environmental Laboratory (Location 8), Bay Point Beach (Location 9), 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 Norwich and Old Lyme (Locations 15C and 16C). Figure 4.1-1 shows a historical trend of TLD exposure rate measurements, comparing an annual average of all indicator TLDs, an annual average bf 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. The average indicator and control readings were both 7.6 uR/hour. This is equivalent to an annual dose of about 67 mrem. Given the error in measurement results this is in agreement with the estimated dose from Millstone of about 0.25 mrem for 2015. The averages of all indicator locations for the period when Millstone Unit 1 was still in operation (1996 to 1999) exhibit the effects of N-16 BWR turbine building skyshine to immediate areas onsite. Skyshine increased exposure rates as high as 6 uR/hr at onsite monitoring stations. The elevated exposure rates from skyshine decreased rapidly with distance to levels indistinguishable from normal background measurements at the nearest offsite monitoring stations. Also apparent in Figure 4.1-1 is a change of the type of TLD dosimeter in the year 2000. The difference in response between the two types. of TLD dosimeters is apparent, with the new type 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 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. Locations 1 and 3 are important because they are onsite and located between the plant and nearby populated areas. 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 that 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 2015 data for Location 3 shows an increase likely attributable to the being closer to granite at the new location. 4-2

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Figiue 4.1-1 uR/hr Aiun1al l~e,u1una Exiiostrre Rate-20Year Histo1y 10 8 6 CD Q) m (j) (j) m a a 0 N 0 0 N N a 0 N (T') 0 0 N -.:i-0 0 N LO D 0 N 4-3 r-... 0 0 N IAll Indicators 1All Controls I I ndicator Loe 1 cl ndicator Loe 3 CD 8 N Q) 0 0 N 0..- 0 N 0 N N..- 0 N (T) 0 N '<:t 0 N L[') 0 N

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 every two weeks 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. pCi/m' pCi/m3 Figure 4.2-1 Air Particulate Gross Beta Activity Monthly Averages - 2015 0.019 ~----------------------------- -+-Indicators -...control 0.007 +------.---~-----.---~-----.---~-----.---~-----.---~--.,.-----, Jan Feb Mar Apr May Jun Jul Aug Sep Figure 4.2-2 Air Particulate Gross Beta Activity Monthly Averages - 5 Year Trend Oct Nov Dec 0.021 +--------------ti'-------------------- -+-Indicators..... Control 0.009 +-------- ---i- --------------------'1---- 0.007 N N N N N N rn rn rn rn rn rn <t <t <t <t <t <t "' "' "' "' "' "' ~.... ~.... ~.... ~.... c > ~ a. > i:. .._ > ~ a. > i:. > ~ c_ > c > ~ a. > i:. > ~ a. > .!!? 0 .!!? 0 .!!? 0 .!!? 0 .!!? 0 Vl z Vl z Vl z Vl z Vl z 4-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 4.4 Airborne Iodine (Table 3) Charcoal cartridges are included at all of the air particulate monitoring stations for the collection of atmospheric iodine. These cartridges were analyzed for 1-131 every two weeks. No detectable levels of 1-131 were seen in the 2015 charcoal samples. 4.4 Air Particulate Gamma (Table 4) The air particulate samples that are utilized for the gross beta analyses are composited quarterly and analyzed for gamma emitting isotopes. The results, as shown in Table 4, 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 any station radioactivity. 4.5 Soil (Table 5) This media is collected annually from one control and two indicator locations. Millstone has collected and analyzed soil since 2001. Prior to 2001, soil had not been sampled for over fifteen years because station related detectable activity had not been detected. Since 2001 no station detectable activity has been seen in these samples. Naturally occurring K-40 is detected in soil. In the Location 3 sample extra counts were detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. Cs-137 from nuclear weapons testing was detected in all three 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. Figure 4.6-1 shows the trend of Cs-137 in soil samples. Except for Location 4, the trend appears to be declining with time. Baseline levels should be useful in the future, when site characterization and decommissioning of the station become the focus during preparations for license termination. E u a. Figure 4.6-1 Cs-137 in Soil 1.8..,--------------------------- Loe 3

Loe 4
*...
Loe 14 1.6 +-

111,__ 1.4 +---*_,,**----r~ ..*~ ... ~ 1.2 0.8 I 0.6 ~ --~ ~, \\ I

- .,Al'........ *~

...._. *~ - - -L I.

*~

'** -** '" \\..... o.2 r-----------------------1---....-.,:,--------, ~ I 0 4,....:..._ II 0 +-------,-------.------r----,..-----,------r------, 2001 2003 2005 2007 2009 2011 2013 2015 Year 4-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station 4.6 Cow Milk (Table 6) Annual Radiological Environmental Operating Report 2015 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 Millstone to be considered an indicator location (i.e. within 10 miles) have ceased operation. One cow milk location, about ten and half miles from the station, was sampled as an extra, not required sample and results are shown in Table 6. Naturally occurring K-40 is the only positive result seen in cow milk. The Sr-89 sample result for the first quarter was larger than the sample error but was less than the minimum detectable concentration (MDC) of 4.87 pCi/I. Each year the Land Use Census is used to identify locations of milk animals that should be included in the monitoring program. It is performed annually and is maintained by observations, door-to-door surveys and consulting with local agriculture authorities. The 2015 census is listed in Appendix A. If a new dairy farm is identified close enough to Millstone to be considered an indicator location, the collection of cow milk at that location would be added. 4.7 Well Water (Table 7) There were no station related radioactivity detected in the samples collected as part of the REMP. Zn-65 in Well #77 sample of December 7 has a reported value which is greater than 1.5 times the 2a error. This value is a result of counts from the natural nuclide Bi-214 in the 1121 Kev peak spilling into the Zn-65 peak at 1116 Kev. Nb-95 in Well #82 samples of June 22 and December 10 had a reported value which are greater than 1.5 times the 2a error. Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. Additional samples from this well, and other wells, were obtained as part of the Groundwater Protection Program (GWPP). Results from the GWPP are reported in the Millstone annual "Radioactive Effluent Release Report" for 2015. 4.8 Fruits and Vegetables (Table 8) Consistent with past years, this media did not show any station effects. Naturally occurring K-40 was detected in all samples. 4.9 Broad Leaf Vegetation (Table 9) Consistent with past years, this media did not show any station effects. Most 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 in the past. This can be attributed to fallout from weapons testing which has been widespread in terrestrial samples for many years. 4-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station 4.10 Seawater (Table 10) Annual Radiological Environmental Operating Report 2015 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 Millstone has been located in the vicinity of discharge (Location 32) 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. Any dose consequences can be assessed by use of the appropriate dilution factors. It's not necessary to have a continuous sampler at the control location due to the historical relative consistency noted in seawater background activity near the Millstone. A technician collects an aliquot from the automatic sampler at Location 32 on a weekly frequency. These samples are composited for monthly analyses. For the Control Location, Giant's Neck (Location 37C), six weekly grab samples are obtained for quarterly compositing. Naturally occurring K-40 was the only detectable gamma activity seen in these samples. Nb-95 in the samples of April 28 and July 28 at Location 32 have a reported value which are greater than 1.5 times the 2cr error. In both cases, extra counts were detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. Measured station related levels of H-3 in seawater from the vicinity of discharge (Location 32) were observed in most samples. Tritium releases are typically higher near 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. Tritium builds up in the reactor coolant during each fuel cycle. It is generated during station 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 Millstone liquid effluents versus the measured environmental concentrations from the vicinity of discharge location. 4-7

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Figure 4.14-1 H-3 Curies Released versus Seawater Concentration 18 Year Trend 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 I\\ Iii I .... *"I' -11 ~ .JI ~ - ~ I * } I l'i... I. '\\ 71 I I.Dl\\ -- \\ f.,. IDL~ I u \\I * "I 0 I .~ ' ~ rl lo ~ 4.11 Bottom Sediment (Table 11) I... "'1 I I I I.. 4t \\ ~ Cmies discba[ged -- REMP pl!i!liter I ~ I I I 1 ~

n.

I\\ ,J

I I It

"-\\ """' I ~ r-f ,., \\ J 'ii \\ ll I \\ ' !(

\\.A

' II...... *o I' * "'1.l I There was no station related radioactivity detected in bottom sediment samples in 2015. Naturally occurring K-40 is seen in all samples and naturally occurring Ac-228 in some samples. Bottom sediment is not a significant dose pathway to man, especially at areas not typically used by the public. 4.12 Aquatic Flora (Table 12) 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 Ac-228 appear 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-11 Om) have been detected in the past but not in 2015. 4.13 Fish (Table 13) The activity in fish is the same as that seen in the past. No activity was observed except for the naturally occurring K-40. 4-8

Dominion Nuclear Connecticut, Inc. Millstone Power Station 4.14 Oysters (Table 14) Annual Radiological Environmental Operating Report 2015 All locations utilize oysters stocked in trays. The stocked trays are kept at sampling areas and represent conditions in those areas. The 4th quarter sample for Location #37, the control location, was collected late on January 15, 2016. At the normal sample date in mid-December it was discovered that the oysters in the stocked tray had been stolen. The oysters were replaced and they remained in location for the procedurally required minimum of 30 days. Thus, the 4th quarter sample result actually represents a sample period of the end of December and the beginning of January. Due to safety concerns Location #32 was moved over eight years ago 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. For 2015, no Millstone activity was observed in oysters both in the quarry and beyond the Millstone discharge area. The near-field dilution factor for liquid discharges from the Millstone Quarry discharge is a factor of 3. Naturally occurring K-40 is seen in all samples. Ac-228 was reported at Location 88 has a value greater than 1.5 times the 2a error. Counts in the Ac-228 peak area were from naturally occurring Pb-214; there was no positive identification for Ac-228. Millstone related Ag-110m and Zn-65 in oysters collected at Location #32 have been seen historically. Oysters have a high capacity for accumulating silver and zinc. Studies have shown that oysters can accumulate as much as 50 times or more the amount of zinc compared to most other seafood. However, in 2015 no plant related radioactivity was detected in oysters. 4.15 Clams (Table 15) Occasionally this media indicates the presence of station related radioactivity. In 2015 no activity was observed except for the naturally occurring K-40. 4.16 Lobsters (Table 16) In 2015 no activity was observed except for the naturally occurring K-40. 4-9

Dominion Nuclear Connecticut, Inc. Millstone Power Station

5.

REFERENCES Annual Radiological Environmental Operating Report 2015

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)

United States of America, Code of Federal Regulations, Title 10, Part 20.1302.

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 027-00, March 13, 2015.

9)

Millstone Nuclear Power Station Unit 1 Defueled Technical Specifications.

10) Millstone Nuclear Power Station Unit 2 Technical Specifications, License No. DPR-65.

11) Millstone Nuclear Power Station Unit 3 Technical Specifications, License No. NPF-49.

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

5-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 APPENDIX A LAND USE CENSUS FOR 2015 A-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 The annual land use census in the vicinity of Millstone was conducted as required by the Millstone 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 licensing website at https://www.elicense.ct.gov/Lookup/GenerateRoster.aspx. 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 2015 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 resident within each directional sector identified by a drive-by survey is assumed to have a garden. If a garden closer than the nearest resident in a sector is identified, that garden is listed as the closest garden in that sector. Goat locations are more difficult to determine, but best efforts are made to consult goat association records including the American Goat Owners Association (http://adga.org/), contact previous owners or perform drive-bys, if necessary. A search of food sources other than milk and local gardens was conducted using the search route on "Local Food Guide to Connecticut" at http://www.farmfresh.org/. Results of the land use census are given in Tables A-1 through A-5. No new dairy animals within 10 miles of the Millstone were located during the census. The dose modeling incorporates the distances listed in Tables A-1, A-2 and A-3. TABLE A-1 Active Dairy Cows Within 20 Miles of Millstone Point - 2015 Direction Distance Miles Meters Location WNW 10.3 16573 Lyme NW 10.5 16895 Old Lyme NE 15.0 24135 Preston NNE 15.3 24618 Preston NNE 16.3 26227 Preston NNE 17.7 28479 Preston NNE 17.8 28640 Preston ENE 17.9 28801 North Stonington N 18.0 28962 Bozrah N 18.5 29767 North Franklin N 18.9 30410 Lebanon NE 19.3 31054 North Stonington N 19.4 31215 North Franklin NNW 19.5 31376 Lebanon N 19.5 31376 North Franklin A-2

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 TABLE A-2 Dairy Goats Within 20 Miles of Millstone Point - 2015 Direction Distance Location Miles Meters WNW 7.3 11746 Old Lyme N 11.2 18021 Oakdale NNW 11.9 19147 Salem ENE 12.0 19308 Mystic ENE 13.2 21239 Mystic NNW 13.2 21239 Salem NW 14.6 23491 East Haddam WNW 14.6 23550 Hadlyme N 15.9 25583 Salem NNE 17.1 27514 Preston N 17.3 27846 Lebanon ENE 17.7 28479 North Stonington NW 17.9 28801 East Haddam NE 17.9 28801 North Stonington WNW 18.4 29606 Haddam ENE 18.5 29767 Westerly, RI N 19.2 30893 Lebanon A-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 TABLE A-3 2015 Resident and Garden Survey Closest Distance For: Downwind Resident Garden Direction miles meters miles meters N 0.96 1552 0.96 1552 NNE 0.54 861 0.54 861 NE 0.48 771 0.48 771 ENE 0.97 1562 0.97 1562 E 0.92 1480 0.92 1480 ESE 1.07 1725 1.07 1725 SE N/A N/A N/A N/A SSE N/A N/A N/A N/A s N/A N/A N/A N/A SSW N/A N/A N/A N/A SW 2.29 3685 2.29 3685 WSW 1.99 3199 1.99 3199 w 1.73 2788 1.73 2788 WNW 1.51 2423 1.48 2381 NW 1.36 2193 1.36 2193 NNW 0.49 787 0.49 787 N/ A - not applicable (over water sectors) A-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table A-4 Poultry and Livestock Breeders or Dealers - 2015 Miles BUSINESS CITY 11.3 TRACTOR SUPPLY COMPANY# 1769 OLD SAYBROOK Poultry 14.7 FLEMINGS FEED AND HARDWARE STONINGTON Poultry 14.9 YANKEE CHICKS NORWICH Poultry 14.9 WYCHWOOD FARM STONINGTON Poultry 16.9 NORWICH AGWAY NORWICH Poultry 17.7 TRACTOR SUPPLY COMPANY #1485 PAWCATUCK Poultry 17.7 SELIGMAN DAIRY CATILE PRESTON Livestock 17.8 SHAGBARK LUMBER & FARM SUPPLIES EAST HADDAM Poultry 17.9 FLEMINGS FEED PRESTON Poultry 17.9 BERIAH LEWIS FARM NORTH STONINGTON Livestock 18.4 CHARLES RIVER NORTH FRANKLIN Poultry 18.9 TRACTOR SUPPLY COMPANY #1731 COLCHESTER Poultry A-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table A-5 Other Foods within 20 miles of Millstone - 2015 Sector Miles Business Location Comments NNW 1.0 Smith's Acres Niantic Fruits and vegetables ENE 3.0 Secchiaroli Farms Waterford Has pigs but feed sources not local WNW 4.9 Four Mile River Farm Old Lyme Eggs, beef, pork NW 5.2 Scott's Yankee Farmer East Lyme Fruits and vegetables, cider NNW 5.4 White Gate Farm East Lyme Vegetables, eggs, chicken, turkey ENE 5.5 Groton Family Farm Groton Vegetables, maple syrup, eggs NNE 6.3 Milaras Piggery Quaker Hill Pork; may get goats later N 7.3 F.R.E.S.H. Farm Waterford Watermelon, vegetables NNW 7.5 Hunts Brook Farm Quaker Hill Garlic, honey NE 8.5 Red Fence Farm Groton Fruits, eggs, chicken, fowl, turkey NNW 8.5 Cranbery Meadow Farm East Lyme Beef N 9.3 Valchris Farm Oakdale Fruit 9.4 Noank Aquaculture Cooperative Noank Clams, oysters ENE 10.2 Willow Spring Farm Mystic Apples, pumpkins Cheese (cow&sheep), ice cream, milk (cow&sheep). NW 10.5 Beaver Brook Farm Old Lyme yougurt (cow&sheep), lamb NNE 10.9 Holmberg Orchards and Winery Gales Ferry Fruits and vegetables, cider, wine 11.5 Bomster Scallops Stonington Scallops, shrimp NE 11.7 Hidden Brook Gardens Ledyard Fruits and vegetables, apple butter and sauce NNW 11.9 Soeltl Farm Salem Eggs, beef, chicken, fowl, pork, turkey, veal NE 12.1 Allyn's Red Barn Ledyard Apples, cidar w 12.1 Hay House Old Saybrook Fruits and vegetables, honey, eggs, feed WNW 12.3 Three Sisters Farm Essex Grapes, honey ENE 12.5 The Funny Farm Ledyard Fruits and vegetables NE 12.5 Cedar Meadows Farm Ledyard Eggs, chicken, lamb, pork, turkey NW 12.6 Provider Farm Salem Vegetables, beef, veal ENE 12.6 Starry Night Farm Stonington Vegetables, eggs NE 12.7 Maugle Sierra Vineyards Ledyard Wine ENE 12.9 Footsteps Farm Stonington Eggs, chicken, pork, turkey NE 13.1 Town Farm LLC Ledyard Vegetables NE 13.6 Aiki Farm Ledyard Vegetables ENE 13.9 JW Beef, LLC Stonington Beef ENE 14.3 Stonington Beef Stonington Beef ENE 14.4 Terra Firma Farm Stonington Vegetables, eggs, beef, chicken, lamb, pork, turkey ENE 14.5 Saltwater Farm Vineyard Stonington Grapes, wine NE 14.8 Wychwood Turkey Farm Stonington Turkey ENE 15.2 Stonington Vineyards Stonington Wine NE 15.5 Roseledge Country Inn and Farm Shoppe Preston Honey, maple syrup ENE 15.8 Tar Barrel Hill Farm Stonington Eggs, chicken ENE 16.8 Davis Farm Pawcatuck, RI Vegetables, corn meal, feed NE 16.9 LoPresti Farm Preston Vegetables NNW 17.0 Common Ground GSA Colchester Fruits and vegetables, eggs, feed NW 17.0 Staehly Farms East Haddam Fruits and vegetables, eggs ENE 17.1 Hubbard's Honey North Stonington Honey NW 17.3 Smith Farm/AVP Haddam Vegetables ENE 17.3 GYOCT Pawcatuck,CT Vegetables, strawberri es, herbs 17.8 Watch Hill Farms Watch Hill, RI Vegetables, honey, eggs N 17.9 Kofkoff Egg Farm Bozrah Eggs N 18.0 Brush Hill Dairy Bozrah Eggs 18.0 Watch Hill Oysters Watch Hill, RI Oysters, quahogs, scallops NE 18.2 Jonathan Edwards Winery North Stonington Wine ENE 18.S Keena Farm Westerly, RI Vegetables, herbs, eggs, ducks, goats N 18.7 Full Bloom Apiary North Franklin Honey N 18.9 M&K Dairy Ladies of Lebanon Lebanon Cheese N 19.3 Blue Slope Farm Franklin Meat (chevon), maple syrup NE 19.3 Maple Lane Farms Preston Fruits and vegetables NE 19.4 Morning Star Meadows Farm North Stonington Vegetables, eggs, lamb, mutton NNW 19.5 Beltane Farm Lebanon Cheese (cow&goat), milk (cow), yougurt (goat) NNW 19.6 Four Winds Farm Lebanon Beef 19.8 Beltane Farm Lebanon Cheese N 19.9 Red and White Orchard Franklin Apples, turkey A-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 APPENDIX B

SUMMARY

OF INTERLABORATORY COMPARISONS B-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station INTRODUCTION Annual Radiological Environmental Operating Report 2015 This appendix summarizes the lntercomparison Program of the Teledyne Brown Engineering (TBE) Laboratory as required by technical specifications for each Millstone unit. Teledyne uses QNQC 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 lnterlaboratory 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 lodine-131 analyses once per quarter milk for Sr-89 and Sr-90 analyses once per quarter water for gamma (6 to 8 nuclides) once per quarter water for tritium analyses once per quarter water for Sr-90 analyses three of four quarters 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 (7 or 9 nuclides) analyses twice per year vegetation for gamma (6 nuclides) analyses twice per year vegetation for Sr-90 analyses twice per year lntercomparison 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. RESULTS For the TBE laboratory, 131 out of 139 analyses performed met the specified acceptance criteria. Eight analyses (AP - Cr-51, U-234/233, Gr A, Sr-90; Soil Sr-90; Water - Ni-3 and U natural; Vegetation Sr-90 samples) did not meet the specified acceptance criteria for the following reasons:

1. Teledyne Brown Engineering's Analytics' June 2015 air particulate Cr-51 result of 323 +/- 45.5 pCi was higher than the known value of 233 pCi with a ratio of 1.39. The upper ratio of 1.20 was exceeded. The air particulate sample is counted on a shelf (above the detector), which is the ideal geometry for this sample. But due to the fact that Cr-51 has the shortest half-life and the weakest gamma energy of the mixed nuclide sample, this geometry produces a larger error for the Cr-51.

Taking into consideration the uncertainty, the activity of Cr-51 overlaps with the known value at a ratio of 1.19, which would be considered acceptable. NCR 15-18

2. Teledyne Brown Engineering's MAPEP March 2015 soil Sr-90 result of 286 Total Bq.kg was lower than the known value of 653 Bq/kg, exceeding the lower acceptance range of 487 Bq/kg. The failure was due to incomplete digestion of the sample. NCR 15-13

3. Teledyne Brown Engineering's MAPEP March 2015 air particulate U-234/233 result of 0.0211 Sq/sample was higher than the known value of 0.0155 Sq/sample, exceeding the upper acceptance range of 0.0202 Sq/sample. Due to the extremely low activity, it was difficult to quantify the U-234/233. Taking into consideration the uncertainty, the activity of U-234/233 overlaps with the known value, which is statistically considered the same value. NCR 15-13 B-2

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015

4. Teledyne Brown Engineering's MAPEP March 2015 air particulate gross alpha result of 0.448 Sq/sample was lower than the known value of 1. 77 Bq/sample, exceeding the lower acceptance range of 0.53 Sq/sample. The efficiency used for gross alpha is made from a non-attenuated alpha standard. The MAPEP filter has the alphas embedded in the filter, requiring an attenuated efficiency. In order to correct the low bias, TBE will create an attenuated efficiency for MAPEP air particulate filters. NCR 15-13

5. Teledyne Brown Engineering's MAPEP September water Ni-63 result of 11.8 +/- 10.8 Bq/l was higher than the known value of 8.55 Bq/l, exceeding the upper acceptance range of 11.12 Bq/l.

The original sample was run with a 10 ml aliquot which was not sufficient for the low level of Ni-63 in the sample. The rerun aliquot of 30 ml produced an acceptable result of 8.81 Bq/l. NCR 15-21

6. Teledyne Brown Engineering's MAPEP September air particulate Sr-90 result of 1.48 Sq/sample was lower than the known value of 2.18 Bq/sample, exceeding the lower acceptance range of 1.53 Bq/sample. In the past, MAPEP has added substances (unusual compounds found in DOE complexes) to various matrices that have resulted in incomplete removal of the isotope of interest for the laboratories analyzing the cross checks. We feel that this is possibly the case with this sample. NCR 15-21

7. Teledyne Brown Engineering's MAPEP September vegetation Sr-90 result of 0.386 Bq/sample was lower than the known value of 1.30 Bq/sample, exceeding the lower acceptance range of 0.91 Bq/sample. In the past, MAPEP has added substances (unusual compounds found in DOE complexes) to various matrices that have resulted in incomplete removal of the isotope of interest for the laboratories analyzing the cross checks. We feel that this is possibly the case with this sample. NCR 15-21

8. Teledyne Brown Engineering's ERA November water Uranium natural result of 146.9 pCi/l was higher than the known value of 56.2 pCi/l, exceeding the upper acceptance limit of 62.4 pCi/L. The technician failed to dilute the original sample, but used the entire 12 ml sample. When recalculated using the 12 ml aliquot, the result of 57.16 agreed with the assigned value of 56.2. NCR 15-19 ANALYTICS ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM TELEDYNE BROWN ENGINEERING ENVIRONMENTAL SERVICES Ide ntifica ti o n Rep o rte d Known R a tio (c)

M o nth/Year Number M a trix Nuc lide Units V a lue (a) Value (b) TBE/An a l:i:;tics E v a lua tio n (d ) M a rc h 2015 E 111 8 1 Milk S r-89 pCi/L 88.9 97.2 0.9 1 A S r-90 pCi/L 1 2.2 1 7.4 0.70 w E 111 82 Milk 1-1 3 1 p C i/L 6 1.3

65. 1 0.94 A

Ce-1 4 1 pCi/ L 104 11 3 0.92 A C r-5 1 p C i/ L 265 276 0.96 A Cs-1 34 p C i/ L 1 38 1 54 0.90 A Cs-1 37 pCi/L 2 0 5 207 0.99 A Co-58 pCi/ L 178 183 0.97 A Mn-54 p C i/ L 1 8 7 1 88 0.99 A Fe-59 p C i/ L 1 82 1 7 7 1.03 A Z n -65 pCi/ L 345 35 1 0.98 A Co-60 pCi/L 379 405 0.94 A E 111 84 A P Ce-1 4 1 p C i 107 85.0 1.26 w C r-5 1 p C i 26 1 224 1.1 7 A Cs-1 34 p C i 7 4.6 77.0 0.97 A Cs-1 37 p C i 99.6 102 0.98 A Co-58 pCi 99.8 11 0 0.9 1 A Mn-54 p C i 99.2 96.9 1.02 A F e-59 p C i 109 11 9 0.92 A Z n -65 p C i 1 88 183 1.03 A C o -60 p C i 200 20 1 1.00 A E 111 83 C h a rcoal 1-1 3 1 p C i 82.9 85.4 0.97 A E 111 85 W ater Fe-55 pCi/ L 1950 1 900 1.03 A B-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 A N ALYTICS E NVIRONMENT A L RADIOAC TIV ITY C ROSS CHECK P ROGRAM TELED Y N E BRO W N ENGINE ERING E NVIRONM E NTAL SERVICES Identification Reported Known Ratio (c) Month/Year Number Matrix Nuclide U nits Value(a) Value (b) TBE/Anal~ics Evaluation (d) June 2015 E11234 Milk Sr-89 pCi/L 94.9 92.6 1.02 A S r-90 pCi/L 14.3 12.7 1.13 A E11238 Milk 1-131 pCi/L 93.2 95.9 0.97 A Ce-141 pCi/L Not provided for this study Cr-51 pCi/L 349 276 1.26 w Cs-134 pCi/ L 165 163 1.01 A Cs-137 pCi/L 143.0 125 1.14 A Co-58 pC i/L 82.0 68.4 1.20 A Mn-54 pCi/L 113 101 1.12 A Fe-59 pCi/L 184 151 1.22 w Zn-65 pC i/L 269 248 1.08 A Co-60 pCi/L 208 193 1.08 A E11237 AP Ce-141 pCi Not provided for this study Cr-51 pCi 323 233 1.39 N (1) Cs-134 pCi 139 138 1.01 A Cs-137 pCi 111 106 1.05 A Co-58 pCi 54.0 57.8 0.93 A Mn-54 pCi 96.8 84.9 1.14 A Fe-59 pCi 162 128 1.27 w Zn-65 pCi 198 210 0.94 A Co-60 pCi 178 163 1.09 A E11236 Charcoal 1-131 pCi 93.9 80 1.17 A June 2015 E11238 Water Fe-55 pCi/L 1890 1790 1.06 A December 2015 E11354 Milk Sr-89 pCi/L 96.2 86.8 1.11 A Sr-90 pCi/L 14.8 12.5 1.18 A E11355 Milk 1-131 pCi/L 95.1 91.2 1.04 A Ce-141 pCi/L 117 129 0.91 A Cr-51 pCi/L 265 281 0.94 A Cs-134 pCi/L 153 160 0.96 A Cs-137 pCi/L 119 115 1.03 A Co-58 pCi/L 107 110 0.97 A Mn-54 pCi/L 153 145 1.06 A Fe-59 pCi/L 117 108 1.08 A Zn-65 pCi/L 261 248 1.05 A Co-60 pCi/L 212 213 1.00 A E11357 AP Ce-141 pCi 89.9 84.0 1.07 A Cr-51 pCi 215 184 1.17 A Cs-134 pCi 103 105 0.98 A Cs-137 pCi 76.6 74.8 1.02 A Co-58 pCi 76.2 71.9 1.06 A Mn-54 pCi 91.4 94.4 0.97 A Fe-59 pCi 78.6 70.3 1.12 A Zn-65 pCi 173 162 1.07 A Co-60 pCi 138 139 0.99 A E11422 AP S r-89 pCi 98.0 96.9 1.01 A Sr-90 pCi 10.0 14.0 0.71 w E11356 Charcoal 1-131 pCi 74.9 75.2 1.00 A E11358 Water Fe-55 pCi/L 2160 1710 1.26 w E11353 Soil Ce-141 pCi/kg 252 222 1.14 A C r-51 pCi/kg 485 485 1.00 A Cs-134 pCi/kg 319 277 1.15 A Cs-137 pCi/kg 292 276 1.06 A Co-58 pCi/kg 193 190 1.02 A Mn-54 pCi/kg 258 250 1.03 A Fe-59 pCi/kg 218 186 1.17 A Zn-65 pCi/kg 457 429 1.07 A Co-60 pCi/kg 381 368 1.04 A March 2015 15-MaW32 Water Am-241 Bq/L 0.632 0.654 0.458 - 0.850 A N i-63 Bq/L 2.5 (1) A P u-238 Bq/L 0.0204 0.0089 (2 ) A Pu-239/240 Bq/L 0.9 0.8 0.582 - 1.082 A B-4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 ANALYTICS ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM TELEDYNE BROWN ENGINEERING ENVIRONMENTAL SERVICES Identification Reported Known Ratio (c) Month/Year Number Matrix Nuclide Units Value(a) Value (b) TSE/Anal;aics Evaluation (d) 15-MaS32 Soil Ni-63 Sq/kg 392 448.0 314 - 582 A Sr-90 Sq/kg 286 653 487 - 849 N (3) 15-RdF32 AP Sr-90 Sq/sample -0.0991 (1) A U-234/233 Sq/sample 0.0211 0.0155 0.0109 - 0.0202 N (3) U-238 Sq/sample 0.095 0.099 0.069- 0.129 A 15-GrF32 AP Gr-A Sq/sample 0.448 1.77 0.53 - 3.01 N (3) Gr-S Sq/sample 0.7580 0.75 0.38-1.13 A 15-RdV32 Vegetation Cs-134 Sq/sample 8.08 7.32 5.12 - 9.52 A Cs-137 Sq/sample 11.6 9.18 6.43-11.93 w Co-57 Sq/sample -0.0096 (1) A Co-60 Sq/sample 6.53 5.55 3.89 - 7.22 A Mn-54 Sq/sample 0.0058 (1) A Sr-90 Sq/sample 0.999 1.08 0.76 - 1.40 A Zn-65 Sq/sample -0. 108 (1) A September 2015 15-MaW33 Water Am-241 Sq/L 1.012 1.055 0.739 - 1.372 A Ni-63 Sq/L 11.8 8.55 5.99-11.12 N (4) Pu-238 Sq/L 0.727 0.681 0.477 - 0.885 A Pu-239/240 Sq/l 0.830 0.900 0.630 - 1.170 A 15-MaS33 Soil Ni-63 Sq/kg 635 682 477-887 A Sr-90 Sq/kg 429 425 298 - 553 A 15-RdF33 AP Sr-90 Sq/sample 1.48 2.18 1.53 - 2.83 N (4) U-234/233 Sq/sample 0.143 0.143 0.100 -0.186 A U-238 Sq/sample 0.149 0.148 0.104-0.192 A 15-GrF33 AP Gr-A Sq/sample 0.497 0.90 0.27 - 1.53 A Gr-S Sq/sample 1.34 1.56 0.78 - 2.34 A 15-RdV33 V egetation Cs-134 Sq/sample 6.10 5.80 4.06 - 7.54 A Cs-137 Sq/sample 0.0002 (1) A Co-57 Sq/sample 8.01 6.62 4.63 - 8.61 w Co-60 Sq/sample 4.97 4.56 3.19 - 5.93 A Mn-54 Sq/sample 8.33 7.68 5.38 - 9.98 A Sr-90 Sq/sample 0.386 1.30 0.91 - 1.69 N (4) (1) False positive test. Zn-65 Sq/sample 6.07 5.46 3.82-7. 10 A May 20 15 RAD-101 Water Sr-89 pCi/L 45.2 63.2 5 1.1 -71.2 N (1) Sr-90 pCi/L 28.0 41.9 30.8 - 48.1 N(1 ) Sa-133 pCi/L 80.6 82.5 63.9 - 90.8 A Cs-134 pCi/L 71.7 75.7 61.8 - 83.3 A Cs-137 pCi/L 187 189 170-210 A Co-60 pCi/L 85.7 84.5 76.0 - 95.3 A Zn-65 pCi/L 197 203 183 - 238 A Gr-A pC i/L

26. 1 42.6 22.1 - 54.0 A

Gr-S pCi/L 28.8 32.9 21.3 - 40.6 A 1-13 1 pCi/L 23.5 23.8 19.7 - 28.3 A U-Nat pCi/L 6.19 6.59 4.99 - 7.83 A H-3 pCi/L 3 145 3280 2770 - 3620 A MRAD-22 Filter Gr-A pCi/filter 28.3 62.2 20.8-96.6 A 011/01/2015 RAD-103 Water Sr-89 pCi/L 40.9 35.7 26.7 - 42.5 A Sr-90 pCi/L 29.3

31. 1 22.7 - 36.1 A

Sa-133 pCi/L 3 1.5 32.5 25.9 - 36.7 A Cs-134 pCi/L 59.65 62.3 50.6 -68.5 A Cs-137 pCi/L 156 157 141 - 175 A Co-60 pCi/L 70.6 71.1 64.0 - 80.7 A Zn-65 pCi/L 145 126 113-149 A Gr-A pCi/L 38.2 51.6 26.9 - 64.7 A Gr-S pCi/L 42.0 36.6 24.1 - 44.2 A 1-1 31 pCi/L 24.8 26.3 21.9-31.0 A U-Nat pCi/L 146.90 56.2 45.7 - 62.4 N (2) H-3 pCi/L 21 100 21300 18700 - 23400 A B-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 ANALYTICS ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM TELEDYNE BROWN ENGINEERING ENVIRONMENTAL SERVICES Identification Reported Known Ratio(c) Month/Year Number Matrix Nuclide Units Value (a) Value (b) TB E/ Anal:i:;!ics Evaluation (d) March 2015 E11181 Milk Sr-89 pCi/L 88.9 97.2 0.91 A Sr-90 pCi/L 12.2 17.4 0.70 w E11182 Milk 1-131 pCi/L 61.3 65.1 0.94 A Ce-141 pCi/L 104 113 0.92 A Cr-51 pCi/L 265 276 0.96 A Cs-1 34 pCi/L 138 154 0.90 A Cs-1 37 pCi/L 205 207 0.99 A Co-58 pCi/L 178 183 0.97 A Mn-54 pCi/L 187 188 0.99 A Fe-59 pCi/L 182 177 1.03 A Zn-65 pCi/L 345 351 0.98 A Co-60 pCi/L 379 405 0.94 A E11184 AP Ce-141 pCi 107 85.0 1.26 w Cr-51 pCi 261 224 1.17 A Cs-134 pCi 74.6 77.0 0.97 A Cs-137 pCi 99.6 102 0.98 A Co-58 pCi 99.8 110 0.91 A Mn-54 pCi 99.2 96.9 1.02 A Fe-59 pCi 109 119 0.92 A Zn-65 pCi 188 183 1.03 A Co-60 pCi 200 201 1.00 A E11183 Charcoal 1-131 pCi 82.9 85.4 0.97 A E11185 Water Fe-55 pCi/L 1950 1900 1.03 A June 2015 E11234 Milk Sr-89 pCi/L 94.9 92.6 1.02 A Sr-90 pCi/L 14.3 12.7 1.13 A E11238 Milk 1-131 pCi/L 93.2 95.9 0.97 A Ce-141 pCi/L Not provided for this study Cr-51 pCi/L 349 276 1.26 w Cs-134 pCi/L 165 163 1.01 A Cs-137 pCi/L 143.0 125 1.14 A Co-58 pCi/L 82.0 68.4 1.20 A Mn-54 pCi/L 113 101 1.12 A Fe-59 pCi/L 184 151 1.22 w Zn-65 pCi/L 269 248 1.08. A Co-60 pCi/L 208 193 1.08 A E11237 AP Ce-141 pCi Not provided for this study Cr-51 pCi 323 233 1.39 N (1) Cs-134 pCi 139 138 1.01 A Cs-137 pCi 111 106 1.05 A Co-58 pCi 54.0 57.8 0.93 A Mn-54 pCi 96.8 84.9 1.14 A Fe-59 pCi 162 128 1.27 w Zn-65 pCi 198 210 0.94 A Co-60 pCi 178 163 1.09 A E11236 Charcoal 1-131 pCi 93.9 80 1.17 A B-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 ANALYTICS ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM TELEDYNE BROWN ENGINEERING ENVIRONMENTAL SERVICES Identification Reported Known Ratio (c) Month/Year Number Matrix Nuclide Units Value (a) Value (b) TBE/Anal~ics Evaluation (d) June 2015 E11238 Water Fe-55 pCi/L 1890 1790 1.06 A December 2015 E11354 Milk Sr-89 pCi/L 96.2 86.8 1.11 A Sr-90 pCi/L 14.8 12.5 1.18 A E11355 Milk 1-131 pCi/L

95. 1 91.2 1.04 A

Ce-141 pCi/L 117 129 0.91 A Cr-51 pCi/L 265 281 0.94 A Cs-134 pCi/L 153 160 0.96 A Cs-137 pCi/L 119 115 1.03 A Co-58 pCi/L 107 110 0.97 A Mn-54 pCi/L 153 145 1.06 A Fe-59 pCi/L 117 108 1.08 A Zn-65 pCi/L 261 248 1.05 A Co-60 pCi/L 212 213 1.00 A E11357 AP Ce-141 pCi 89.9 84.0 1.07 A Cr-51 pCi 215 184 1.17 A Cs-134 pCi 103 105 0.98 A Cs-137 pCi 76.6 74.8 1.02 A Co-58 pCi 76.2 71.9 1.06 A Mn-54 pCi 91.4 94.4 0.97 A Fe-59 pCi 78.6 70.3 1.12 A Zn-65 pCi 173 162 1.07 A Co-60 pCi 138 139 0.99 A E11422 AP Sr-89 pCi 98.0 96.9 1.01 A Sr-90 pCi 10.0 14.0 0.71 w E11356 Charcoal 1-131 pCi 74.9 75.2 1.00 A E11358 Water Fe-55 pCi/L 2160 1710 1.26 w E11353 Soil Ce-141 pCi/kg 252 222 1.14 A Cr-51 pCi/kg 485 485 1.00 A Cs-134 pCi/kg 319 277 1.15 A Cs-137 pCi/kg 292 276 1.06 A Co-58 pCi/kg 193 190 1.02 A Mn-54 pCi/kg 258 250 1.03 A Fe-59 pCi/kg 218 186 1.17 A Zn-65 pCi/kg 457 429 1.07 A Co-60 pCi/kg 381 368 1.04 A (1) AP Cr Cr-51 has the shortest half-life and the weakest gamma energy of the mixed nuclide sample, which produces a large error. Taking into account the error, the lowest value would be 119% of the reference value, which would be considered acceptable. NCR 15-18 (a) Teledyne Brown Engineering reported result. (b) The Analytics known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation. (c) Ratio of Teledyne Brown Engineering to Analytics results. (d) Analytics evaluation based on TBE internal QC limits: A= Acceptable, reported result falls within ratio limits of 0. 80-1. 20. W-Acceptable with warning, reported result falls within 0. 70-0. 80 or 1. 20-1. 30. N = Not Acceptable, reported result falls outside the ratio limits of< 0. 70 and> 1.30. B-7

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 I DOE's MIXED ANAL YTE PERFORMANCE EVALUATION PROGRAM (MAPEP) TELEDYNE BROWN ENGINEERING ENVIRONMENTAL SERVICES Identification Reported Known Acceptance Month/Year Number Media Nuclide* Units Value (a) Value (b) Ran~e Evaluation (c) March 2015 15-MaW32 Water Am-241 Sq/L 0.632 0.654 0.458 - 0.850 A Ni-63 Sq/L 2.5 (1) A Pu-238 Sq/L 0.0204 0.0089 (2) A Pu-239/240 Sq/L 0.9 0.8 0.582 - 1.082 A 15-MaS32 Soil Ni-63 Sq/kg 392 448.0 314 - 582 A Sr-90 Sq/kg 286 653 487 - 849 N (3) 15-RdF32 AP Sr-90 Sq/sample -0.0991 (1) A U-234/233 Sq/sample 0.0211 0.0155 0.0109 - 0.0202 N (3) U-238 Sq/sample 0.095 0.099 0.069- 0.129 A 15-GrF32 AP Gr-A Sq/sample 0.448 1.77 0.53 - 3.01 N (3) Gr-S Sq/sample 0.7580 0.75 0.38-1.13 A 15-RdV32 Vegetation Cs-134 Sq/sample 8.08 7.32 5.12-9.52 A Cs-137 Sq/sample 11.6 9.18 6.43 - 11.93 w Co-57 Sq/sample -0.0096 (1) A Co-60 Sq/sample 6.53 5.55 3.89-7.22 A Mn-54 Sq/sample 0.0058 (1) A Sr-90 Sq/sample 0.999 1.08 0.76 - 1.40 A Zn-65 Sq/sample -0.108 (1) A September 2015 15-MaW33 Water Am-241 Sq/L 1.012 1.055 0.739 - 1.372 A Ni-63 Sq/L 11.8 8.55 5.99 -1 1.12 N (4) Pu-238 Sq/L 0.727 0.681 0.477 - 0.885 A Pu-239/240 Sq/L 0.830 0.900 0.630 -1.170 A 15-MaS33 Soil Ni-63 Sq/kg 635 682 477 - 887 A Sr-90 Sq/kg 429 425 298-553 A 15-RdF33 AP Sr-90 Sq/sample 1.48 2.18 1.53 - 2.83 N (4) U-234/233 Sq/sample 0.143 0.143 0.100 - 0.186 A U-238 Sq/sample 0.149 0.148 0.104 - 0.192 A 15-GrF33 AP Gr-A Sq/sample 0.497 0.90 0.27 - 1.53 A Gr-S Sq/sample 1.34 1.56 0.78-2.34 A 15-RdV33 Vegetation Cs-134 Sq/sample 6.10 5.80 4.06 - 7.54 A Cs-137 Sq/sample 0.0002 (1) A Co-57 Sq/sample 8.01 6.62 4.63 - 8.61 w Co-60 Sq/sample 4.97 4.56 3.19-5.93 A Mn-54 Sq/sample 8.33 7.68 5.38 - 9.98 A Sr-90 Sq/sample 0.386 1.30 0.91 - 1.69 N (4) (1) False positive test. Zn-65 Sq/sample 6.07 5.46 3.82-7.10 A (2) Sensitivity evaluation. (3) Soil Sr incomplete digestion of the sample resulted in low results; AP U-2341233 - extremely low activity was difficult to quantify AP Gr-A - the MAPEP filter has the activity embedded in the filter. To corrected the low bias, TBE will create an attenuated efficiency for MAPEP samples. NCR 15-13 (4) Water Ni-63 extremely low activity was difficult to quantify; AP & Vegetation Sr-90 was lost during separation, possible from substance added by MAPEP NCR 15-21. (a) Teledyne Brown Engineering reported result. (b) The MAPEP known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation. (c) DOE/MAPEP evaluation: A=acceptable, W=acceptable with warning, N=not acceptable. B-8

Dominion Nuclear Connecticut, Inc. Millstone P wer Station ~ Annual Radiological Environmental Operating Report 2015 ERA ENVIRONMENTAL RADIOACTIVITY CROSS CHECK PROGRAM TELEDYNE BROWN ENGINEERING ENVIRONMENTAL SERVICES Identification Reported Known Acceptance Month/Year Number Media Nuclide Units Value (a) Value (b) Limits Evaluation (c) May 2015 RAD-101 Water Sr-89 pCi/L 45.2 63.2 51.1 - 71.2 N(1) Sr-90 pCi/L 28.0 41.9 30.8-48.1 N(1) Ba-133 pCi/L 80.6 82.5 63.9-90.8 A Cs-134 pCi/L 71.7 75.7 61.8 - 83.3 A Cs-137 pCi/L 187 189 170- 210 A Co-60 pCi/L 85.7 84.5 76.0 - 95.3 A Zn-65 pCi/L 197 203 183 - 238 A Gr-A pCi/L 26.1 42.6 22.1 - 54.0 A Gr-B pCi/L 28.8 32.9 21.3 - 40.6 A 1-131 pCi/L 23.5 23.8 19.7 - 28.3 A U-Nat pCi/L 6.19 6.59 4.99 - 7.83 A H-3 pCi/L 3145 3280 2770 - 3620 A MRAD-22 Filter Gr-A pCi/filter 28.3 62.2 20.8-96.6 A 011/01/2015 RAD-103 Water Sr-89 pCi/L 40.9 35.7 26.7 - 42.5 A Sr-90 pCi/L 29.3 31.1 22.7 - 36.1 A Ba-133 pCi/L 31.5 32.5 25.9 - 36.7 A Cs-134 pCi/L 59.65 62.3 50.6 - 68.5 A Cs-137 pCi/L 156 157 141 - 175 A Co-60 pCi/L 70.6 71.1 64.0 - 80.7 A Zn-65 pCi/L 145 126 113 - 149 A Gr-A pCi/L 38.2 51.6 26.9 - 64.7 A Gr-B pCi/L 42.0 36.6 24.1 - 44.2 A 1-131 pCi/L 24.8 26.3 21.9-31.0 A U-Nat pCi/L 146.90 56.2 45.7 - 62.4 N (2) H-3 pCi/L 21100 21300 18700 - 23400 A (2) NCR 15-19 has been initiated to address the failure. MRAD-23 Filter Gr-A pCi/filter Lost during processing (1) Yield on the high side of our acceptance range indicates possibility of calcium interference. NCR 15-09 (2) Technician failed to dilute original sample. If dilulted, the result would have been 57.1, which fell within the acceptance limits. NCR 15-19 (a) Teledyne Brown Engineering reported result. (b) The ERA known value is equal to 100% of the parameter present in the standard as determined by gravimetric and/or volumetric measurements made during standard preparation. (c) ERA evaluation: A=acceptable. Reported result falls within the Warning Limits. NA=not acceptable. Reported result falls outside of the Control Limits. CE=check for Error. Reported result falls within the Control Limits and outside of the Warning Limit. B-9

Dominion Nuclear Connecticut, Inc. Rope Ferry Rd., Waterford, CT 06385 Mailing Address: P.O. Box 128 Waterford, CT 06385 dam.com APR 2 8 2016 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 DOMINION NUCLEAR CONNECTICUT, INC. MILLSTONE POWER STATION UNITS 1, 2, AND 3 Serial No. MPS Lic/AVM Docket Nos. License Nos. 2015 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT 16-166 RO 50-245 50-336 50-423 DPR-21 DPR-65 NPF-49 This letter transmits the Annual Radiological Environmental Operating Report for the Millstone Power Station, for the period January 2015 through December 2015. This satisfies the provisions of Section 5.7.2 of Millstone Power Station Unit 1 Permanently Defueled Technical Specifications (POTS), 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. Mr. Thomas G. Cleary at (860) 444-4377. Sincerely, ws-+/-;; Brandford L. Stanley Director, Nuclear Station Safety and Licensing

Attachments: 1 Commitments made in this letter:

1. None.

cc: U. S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 S. J. Giebel NRC Project Manager Millstone Unit 1 U.S. Nuclear Regulatory Commission Two White Flint Nort,h, Mail Stop T-8 F5 11545 Rockville Pike Rockville, MD 20852-2738 L. A. Kauffman NRC Inspector U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 H. W Anagnostopoulos NRC Inspector U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 R. V. Guzman Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 2of4 NRC Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission -- One White Flint North, Mail Stop 08 C2 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

(2copies) Director Bureau of Air Management Monitoring & Radiation Division Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 3of4 Department of Energy and Environmental Protection 79 Elm Street Hartford, CT 06106-5127 Regional Radiation Representative (EPA Region 1, Boston) U. S. Environmental Protection Agency (Region 1) 5 Post Office Square Suite 100 Boston, MA 02109 Regional Representative 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 Chairman Waterford-East Lyme Shellfish Commission Waterford Town Hall Waterford, CT 06385 S. Brietmaier American Nuclear Insurers 95 Glastonbury Blvd. Glastonbury, CT 06033 D. Carey Connecticut Department of Agriculture Aquaculture Division P. 0. Box 97 Millford, CT 06460

D. Steward First Selectman Town of Waterford Waterford Town Hall Waterford, CT 06385 M. C. Nickerson First Selectman Town of East Lyme PO Box 519 Niantic, CT 06357 University Of Connecticut Library Serials Department Storrs, CT 06268 Mrs. John Mingo 69 Spithead Road Waterford, CT 06385 Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 4 of 4

ATTACHMENT 1 Serial No. 16-166 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 2015 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT MILLSTONE POWER STATION UNITS 1, 2, AND 3 DOMINION NUCLEAR CONNECTICUT, INC. (DNC)

Millstone Power Station 2015 Radiological Environmental Operating Report January 1, 2015 - December 31, 2015 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 2015 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. Millstone Power Station Annual Radiological Environmental Operating Report 2015 ,...., TABLE OF CONTENTS,...., EXECUTIVE

SUMMARY

.................................................................................................. i

1.

INTRODUCTION........................................................................................ 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 Operations............................................................. 1-3 1.5 Radioactive Effluent Control............................................................. 1-8 1.6 Radiological Impact on Humans.............................. :...................... 1-10

2.

PROGRAM DESCRIPTION........................................................................... 2.1 2.1 Sampling Schedule And Locations................................................... 2.1 2.2 Samples Collected During Report Period......................................... 2-7 2.3 Required Samples Not Collected During the Report Period........... 2-8

3.

RADIOCHEMICAL RESUL TS........................................................................ 3-1 3.1 Summary Table................................................................................ 3-1 3.2 Data Tables....................................................................................... 3-5

4.

DISCUSSION OF RESULTS..........................................................................4-1 4.1 Gamma Exposure Rate (Table 1)....................................................4-1 4.2 Air Particulate Gross Beta Radioactivity (Table 2)...........................4-4 4.3 Air Iodine (Table 3)...............................................................4-5 4.4 Air Particulate Gamma (Table 4)...................................................... 4-5 4.5 Soil (Table 5)........................................ *........................................... 4-5 4.6 Cow Milk (Table 6)........................................................................... 4-6 4.7 Well Water (Table 7)........................................................................ 4-6 4.8 Fruits and Vegetables (Table 8)........................ ~......................,.......4-6 4.'9 Broad Leaf Vegetation (Table 9)................................................ :......4-6 4.10 Seawater (Table 10)........................................................................4-7 4.11 Bottom Sediment (Table 11 )................,........................................... 4-8 4.12 Aquatic Flora (Table 12)................................. ~................................ 4-8 4.13 Fish (Tables 13)............................................................................... 4-8 4.14 Oysters (Table 14)........................................................................... 4-9 4.15 Clams (Table 15)............................................................................... 4-9 4.16 Lobsters (Table 16).........................................................................4-9

5.

REFERENCES............................................................................ 5-1 APPENDIX A - LAND USE CENSUS FOR 2015................................................. A-1 APPENDIX B -

SUMMARY

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

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015

Dominion Nuclear Connecticut, Inc. Millstone Power Station INTRODUCTION Annual Radiological Environmental Operating Report 2015 EXECUTIVE

SUMMARY

This report summarizes the results of the Radiological Environmental Monitoring Program (REMP) conducted in the vicinity of the Millstone Nuclear Power Station (Millstone) during the period from January 1 to December 31, 2015. This document has been prepared in accordance with the requirements of the separate Technical Specifications for Millstone Units 1, 2 and 3. The REMP has been established to monitor the radiation and radioactivity released to the environment as a result of Millstone's operation. This program, initiated in April 1967, includes the collection, analysis, and evaiuation of radiological data in order to assess* the impact of Millstone on the environment and on the general public. SAMPLING AND ANALYSIS The environmental sampling media collected in the vicinity of Millstone and at distant locations included terrestrial samples in the form of air particulate filters, charcoal cartridges, soil, cow milk, well water, broadleaf vegetation, fruits and vegetables; and aquatic samples.in the form of seawater, bottom sediment, aquatic flora, fish, oysters, clams and lobster. During 2015, there were 721 samples collected from the atmospheric, aquatic, and terrestrial environments. In addition, 176 exposure measurements were obtained using environmental thermoluminescent dosimeters (TLDs). A discussion of all discrepancies from the sample collection requirements in the Millstone Radiological Effluent Monitoring and Offsite Dose Calculation Manual (REMO DCM) is given in Section 2.3 of this report. Teledyne Brown Engineering, Inc. of Knoxville, Tennessee performed the sample analyses and Environmental Dosimetry Company of Sterling, Massachusetts performed the TLD analyses. LAND USE CENSUS The annual land use census in the vicinity of Millstone was conducted as required by the Millstone REMO DCM. 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 2015 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. However, for dose calculation, garden distances are based on nearest resident assuming that a resident may plant a new garden. This gives a more conservative dose result. Goat locations are more difficult to determine, but best efforts are made by reviewing membership list of the American Dairy Goat Association records, contacting previous owners and, if necessary, performing visual drive-by inspections. RADIOLOGICAL IMPACT TO THE ENVIRONMENT The radioactivity detected in some samples was from non-station related sources, such as fallout from past nuclear weapons tests and naturally occurring radionuclides. All terrestrial samples collected as part of the Millstone REMP did not show any station related radioactivity.

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Monitoring of seawater in the area of the discharge indicated the presence of tritium, a station related radionuclide. Tritium was only found in seawater onsite jnside the mixing zone of the quarry discharge at levels that were expected from routine station operation. Offsite ambient radiation measurements using environmental TLDs beyond the site boundary ranged between 45 and 95 milliRoentgens per year. The range of ambient radiation levels observed with the TLDs is consistent with natural background radiation levels for Connecticut. RADIOLOGICAL IMPACT TO THE GENERAL PUBLIC During 2015, radiation doses to the general public as a result of Millstone'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 (whole body) dose to the maximally exposed member of the general public from radioactive effluents and ambient radiation resulting from Millstone operations for 2015 was approximately 0.25 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. CONCLUSIONS The 2015 REMP for Millstone resulted in the collection and analysis of 897 environmental samples and measurements. The data obtained were used to determine the impact of Millstone's operation oil 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 Millstone's operation.

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 acronym 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 acronym for radiation absorbed dose. One rad is equal to the absorption of 100 ergs of energy per gram of tissue. ii

Dominion Nuclear Connecticut, Inc. Millstone Power Station

1.

INTRODUCTION Annual Radiological Environmental Operating Report 2015 This section provides an overview of the Millstone 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 2015 performed by Dominion Nuclear Connecticut (DNC) for Millstone is discussed in this report. Since the operation of a nuclear power station results in the release of small amounts of radioactivity and low levels of radiation, the Nuclear Regulatory Commission (NRC) requires by regulations and technical specifications that a program be established to monitor radiation and radioactivity in the environment (References 1, 6, 9, 10 & 11). This report, published annually per Millstone's Technical Specifications (section 5.7.2 for Millstqne Unit 1, section 6.9.1.6A for Millstone Unit 2 and Section 6.9.1.3 for Millstone Unit 3), summarizes the,results of measurements of radiation and radioactivity in the environment in the vicinity of Millstone and at distant locations during the period January 1 to December 31,2015. 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 milk, well water, broadleaf vegetation, fruits, vegetables, seawater, bottom sediment, aquatic flora, fish, 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 Millstone operation and other natural and man-made sources. These results are reviewed by Millstone'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 station 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 Millstone. 1.2 Radiation and Radioactivity All matter is made of atoms. Nuclear radiation is energy or particles that are 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 fallout from nuclear weapons testing. Examples of radioactive fallout that could be present in environmental samples are cesium-137 and strontium-90. Some examples of radioactive materials released from a nuclear power station are hydrogen-3 (tritium), cesium-137, iodine-131, strontium-90, and cobalt-60. 1-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 acronym 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 acronym 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 & 5). The per capita dose has increased since the early 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 one-trillionth of a Curie and 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 Corresponding Approximate Doses (1) NATURAL Radiation Dose Source (mrem/vear) Internal, inhalation<2l 228 External, space 33 Internal, ingestion 29 External, terrestrial 21 Approximate Total 311 {1) information from References 3 and 4 (2) from radon and thoron MAN-MADE Radiation Dose Source (mrem/year) Medica1(3l 300 Consumer(4l 13 Industrial, security, 0.3 educational, research Occupational 0.5 Weapons Fallout < 1 Nuclear Power Stations < 1 Approximate Total 314 (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) 1-2

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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-? and carbon-14 are formed in this way. Exposure to cosmic and cosmogenic sources of radioactivity results in about 33 mrem of radiation dose per year. Additionally, natural radioactivity is in our body and. in the food we eat (about 29 mrem/year), the ground we walk on (about 21 mrem/year) and the air we breathe (about 228 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 311 mrem per year. In addition to natural 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 as cigarettes, building materials and commercial air travel contribute about 13 mrem/year. Much smaller doses result from weapons fallout (less than 1 mrem/year) and nuclear power stations (less than 1 mrem/year). Typically, the average person in the United States receives approximately 314 mrem per year from man-made sources. 1.4 Nuclear Reactor Operations Millstone generates about 2100 megawatts of electricity at full power, which provides approximately one-third of the power consumed in the State of Connecticut. Millstone Unit 2 and Millstone Unit 3 are pressurized water reactors (Millstone Unit 1, 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, Connecticut. Commercial operation of Millstone Unit 2 began in December 1975 and Millstone Unit 3 in May 1986. Millstone was operational during most of 2015, with the exception of a refueling outage at Millstone Unit 2 in October. The annual capacity factor for Millstone Unit 2 was 88.7% and for Millstone Unit 3 was 100.5%. 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 (see Figure 1.4-1 ). The cooling water source for Millstone is the Niantic Bay. 1-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 The key difference between nuclear power and conventional power is the source of heat used to boil the water. Conventional stations burn fossil fuels in a boiler, while nuclear stations 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, 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). SIMPLIFIED DIAGRAM OF A PRESSURIZED WATER REACTOR Pressuri:z:ed water reactor-a common type of Light Water Reactor Figure 1.4-1 1-4 (LWR)

~----------.....,*coNOENSER COO UNG WATER

-.;;...;,;;;,,;;,;,,;;;;,;;i;iiii0ii __ ,TA.KiNC WASTE HEAT TOTHE ENViRONMEN't

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 (see Figure 1.4-2). Neutron *

Uranium Fission Products Figure 1.4-2 Uranium

~ WlllJJ Uranium Radioactive Fission Product Formation 1-5 1.,....... Neutrons Fission Products

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Radioactive activation products (see Figure 1.4-3), 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). 0

col.ii~icm
with stable

co6alt Nucleus Figure 1.4-3

- ~

Radioactive Activation Product Formation Co-60 Radioactive.

cci*balt::Ntic1eus At Millstone there are five independent protective barriers that confine these radioactive materials. These five barriers are:

fuel pellets; fuel cladding; reactor vessel and associated piping and equipment; primary containment and, secondary containment (enclosure building). 1-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Entjronmental Operating Report 2015 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. Radioactivity can also escape into coolant water through cladding defects and failures. 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. During operation the containment is closed but small amounts of radioactivity may be released from primary containment by venting during operation to maintain proper containment pressure. During maintenance and refueling outages containment is open and small amounts of radioactivity is released during this time when the fuel has been moved out of the reactor cavity in containment. 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 Millstone'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 mech~nical 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. The control of radioactive effluents at Millstone will be discussed in more detail in the next section. 1-7

Dominion Nuclear Connecticut, Inc. Millstone Power Station 1.5 Radioactive Effluent Control Annual Radiological Environmental Operating Report 2015 The small amounts of radioactive liquids arid gases that might escape the first two barriers are processed in the liquid and gaseous 1 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 radioactivity in liquids discharged into Niantic Bay. Wastes processed through liquid radwaste treatment can be purified and, in some cases, re-used in station systems. Prior to release, the radioactivity in any 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 will 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 environment 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 environment. 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. 1-8

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 The preceding discussion illustrates that many controls exist to reduce the radioactive liquid effluents released to the environment 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 Millstone Unit 3) ventilation system; Millstone station stack and units' vent effluent radioactivity monitors; sampling and analysis of Millstone station stack and units' 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 station process computer aids in tracking the monitor readings. To supplement the information continuously provided by the detector, air samples are taken periodically from the units' containments, Millstone station stack and units' vents. These samples are analyzed to quantify the total amount of radioactive gases, radioactive iodines, radioactive particulate and tritium released in gaseous effluents. Gases from the primary coolant are held up in waste gas decay tanks for decay at Millstone Unit 2. Gaseous waste at Millstone Unit 3 is purified through a process gas system, consisting of high-efficiency particulate air filters and charcoal adsorber beds. Gases from periodic venting of the Millstone Unit 2 containment are released through a similar process system (Enclosure Building Filtration System) while gases from the Millstone Unit 3 containment vacuum pumps are released without treatment. If necessary, Millstone Unit 3 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 Millstone Unit 2 are filtered by high-efficiency particulate filters while at Millstone Unit 3 these are not normally filtered. If necessary, particulate and charcoal filters can be used for these purges. Normally, for Unit 2, the air released from the unit vent is from the ventilation of the auxiliary (which includes the fuel pool), service and enclosure buildings. For Unit 2, fuel pool and enclosure building ventilation can be redirected to the Millstone Site Stack. Normally, for Unit 3, the air released from the unit vent is from the ventilation of the auxiliary, fuel, service, waste disposal and enclosure buildings. For Unit 3, enclosure building ventilation can be redirected to the Millstone Site Stack. 1-9

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 are closed to stop the release and ensure that federal regulatory limits are always met. 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. 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 calculation of the dose impact to the general public from Millstone's radioactive effluents. The purpose of this calculation is to periodically assess the dose to the general public resulting from radioactive effluents to ensure that the dose is being maintained as far below the federal dose limit 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 Millstone during each 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. The liquid and gaseous effluents were well below the federal release limits and were a small percentage of the Millstone REMO DCM 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, 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 Millstone to its effect on man. The movement of radioactivity through the environment and its transport to humans is portrayed in Figure 1.6. 1-10

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 EXAMPLES OF Millstone's RADIATION EXPOSURE PATHWAYS LIQUID EFFLUENTS

1. SHORELINE DIRECT RADIATION (FISHING, PICNICJNG) ~

2. DIRECT RADIATION (IMMERSION IN OCEAN, BOATING, SWIMMING)

INGESTION

3. CONSUMPTION (FISH, SHELLFISH)

3. DIRECT RADIATION (STATIO~ 2. AIR INHALATION ef /V"" /

1. DIRECT RADIATION

. *e LY e;sMERs10NJ ~ 4.- Figure 1.6

5. CONSUMPTION (VEGETATION) t DEPOSITION

(/ &B:m; ~ DEPOSITION Radiation Exposure Pathways 1-11

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 There are four pathways in which liquid effluents affect humans: external radiation from liquid effluents that deposit and accumulate on the shoreline; external radiation during boating from radioactivity in ocean water; external radiation from immersion in ocean water containing radioactivity; and, internal radiation from consumption of fish and shellfish containing radioactivity absorbed from the liquid effluents. There are five major ways in which gaseous effluents affect humans: external radiation from immersion in an airborne plume of radioactivity; internal radiation from inhalation of airborne radioactivity; external radiation from deposition of radioactive effluents on the ground; 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. Ambient (direct) radiation emitted from sources of radioactivity at Millstone comes 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 a small amount 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. However, the operation of Millstone 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 NRG-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 specified in the Millstone'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. 1-12

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 After dose calculations are performed, the results are compared to the dose limits for the public as specified in NRC':s technical specifications for Millstone (References 9-11 ). The technical specifications limits for the dose to a member of the general public from radioactive material in liquid effluents released to unrestricted areas are: 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 technical specifications limits for dose due to release of radioactivity in gaseous effluents is restricted to: less than or equal to 10 mrad per year for gamma radiation from noble gases, less than or equal to 20 mrad per year for beta radiation from noble gases and less than or equal to 15 mrem per year to any organ from iodine-131, iodine-133, tritium, and all particulate radionuclides with half-lives greater than 8 days. The technical specifications limits for total dose from all three Millstone units due to release of radioactivity in gaseous and liquid effluents and direct radiation is restricted 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. 1-13

Dominion Nuclear Connecticut, Inc. Millstone Power Station

2. PROGRAM DESCRIPTION 2.1 Sampling Schedule and Locations Annual Radiological Environmental Operating Report 2015 The sample locations and the sample types and frequency of analysis are given in Tables 2-1 and 2-2 and shown in Figures 2.1 and 2.2. The program as described on Table 2-2 only lists the required samples as specified in the REMO DCM. However, in order to identify the locations of the extra samples, all locations (both required and extra) are listed in Table 2-1.

2-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table 2-1 Environmental Monitoring Program Sampling Types and Locations

.:;::.;::::::;:,:c::;: Onsite - Old Millstone Rd.

Onsite - Weather Shack Onsite - Bird Sanctuary Onsite - Albacore Drive Onsite - MP3 Discharge Onsite - Quarry Discharge Onsite - Env. Lab Dock Onsite-Env. Lab Onsite - Bay Point Beach ..,.. *.:***'"*****""' Pleasure Beach Great Neck Country Club Fisher's Island, NY Mystic, CT Ledyard, CT Norwich, CT Old Lyme, CT Site Boundary Cow Within 10 Miles Within 10 Miles Beyond 10 Miles .......... ~"*"""*** Beyond 10 Miles Niantic Two Tree Island West Jordan Cove West Jordan Cove '*'"'""*"'***.<**>.*'"** Niantic Shoals Vicinity of Discharge Vicinity of Discharge Seaside Point Niantic Bay Niantic Bay Black Point ,.,;.;;:,;,,;;;:*>:":.:*, Giant's Neck Waterford Shellfish Bed #1 Myrock Avenue Billow Road Black Point Onsite - Schoolhouse Onsite - Access Road .........,..........,."'". Old Lyme - Hillcrest Ave. East L me - W. Main St. 0.6 Mi, NNW 0.3 Mi, S 0.3 Mi, NE 1.0 Mi, N 0.1 Mi, SSE 0.3 Mi, SSE 0.3 Mi, SE 0.3 Mi, SE 0.4 Mi, W 1.2 Mi, E 1.6 Mi, ENE 8.0 Mi, ESE 11.5 Mi, ENE 12.0 Mi, NE 14.0 Mi, N 8.8Mi,W 0.5 Mi, NE 10.5 Mi, WNW < 10 Miles < 10 Miles > 10 Miles > 10 Miles 1.?Mi, WNW 0.8Mi, SSE 0.4 Mi, ENE-ESE 0.4 Mi, NNE 1.8 Mi, NW < 0.1 Mi < 0.1 Mi 1.8 Mi, ESE <0.5 Mi, SSW-W 0.3 Mi, WNW 3.0Mi,WSW 3.5 Mi, WSW 1.0 Ml, NW 3.2 Mi, ENE 2.4 Mi, WSW 2.6 Mi, SW 0.1 Mi, NNE 0.5 Mi, NNW 4.6Mi,WSW 4.5Mi,W 2-2 TLD, Air Particulate, Iodine, Vegetation TLD, Air Particulate, Iodine TLD, Air Particulate, Iodine, Soil TLD, Air Particulate, Iodine, Soil TLD TLD TLD TLD TLD TLD, Air Particulate, Iodine, Vegetation TLD, Air Particulate, Iodine TLD TLD TLD, Soil TLD, Air Particulate, Iodine TLD Vegetation Milk Vegetation Fruits and/or Vegetables3 Vegetation Fruits and/or Vegetables3 TLD, Air Particulate, Iodine Fish 4 Clams, Fish4 Fucus Bottom Sediment, Oysters Bottom Sediment, Oysters, Fish4, Seawater Fucus Bottom Sediment Lobster, Fish4 Fucus Fucus Bottom Sediment, Oysters, Seawater Clams TLD TLD TLD TLD TLD TLD TLD

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 .:~3~~~::::.:1£~:~~(1'~~~~;~~,ffi~;~*;i":"~~.>;:~1::;:i:*;~-;;ti1([!;:*~;,~[.).~:/ij~i~~~1~~:6}cg:~~:ir:s~~:;~~~->,1~~N~:~<~~~*Jr~~lt:;*~~~*i*:;.. ~;:C:~/:,:i~r '~i~ East Lyme - Corey Rd. 3.4 Mi, WNW TLD East Lyme - Society Rd. 3.6 Mi, NW TLD East Lyme - Manwaring Rd. 2.. 1 Mi,W TLD East Lyme - Smith Ave. 1.5 Mi, NW TLD Waterford - River Rd. 1.1 Mi, NNW TLD Waterford - Gardiners Wood Rd 1.4 Mi, NNE TLD Waterford - Magonk Point 1.8 Mi, ESE TLD New London - Mott Ave. 3.7 Mi, E TLD New London - Ocean Ave. 3.6Mi, ENE TLD Waterford -Miner Ave. 3.4 Mi, NNE TLD Waterford - Parkway South 4.0 Mi, N TLD Waterford - Boston Post Rd. 4.3 Mi, NNW TLD East Lyme - Columbus Ave. 1.9 Mi, WNW TLD Waterford - Jordon Cove Rd. 0.8 Mi, NE TLD Waterford - Shore Rd. 1.1 Mi, ENE TLD Waterford - Bank St. 3.2 Mi, NE TLD NAP Parking Lot - Fit Center 0.4 Mi, NW TLD 1-MW-XFMR-03 5 Onsite Well Water MW-GPl-1 5 Onsite Well Water Site Switchyard Fence 0.3 Mi, N TLD Ball Field Foul Pole 0.6 Mi, N TLD Waterford -Windward Way & 0.5 Mi, NE TLD Shotgun ISFSl-1 Up-gradient of ISFSI Well Water ISFSl-2 Down-gradient of ISFSI Well Water ISFSl-3 Down-gradient of ISFSI Well Water M3-MW-1 5 Onsite Well Water S2-MW-1 5 On site Well Water MW-6B 5 On site Well Water S3-MW-2 5 Onsite Well Water DEEP Dock 0.2 Mi, WNW Oysters Aquatic background >4 Mi of discharge Lobster Thames River 4Mi, E Fucus Footnotes:

1. Key:

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

2. Release points are the Millstone station stack for terrestrial locations and the quarry cut for aquatic locations.

3. A fruit or vegetable sample may count as a required vegetation sample.

4. Fish required to be sampled at Location #35 and from one of three other locations (#28, #29 or #32).

5. Any onsite well may be substituted.

2-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table 2-2 Required Sampling Frequency & Type of Analysis

>(:*.

- E?(pq*s.ii_i"~.Pa~fiway*:** * *.::.J:Jo,)'?f **.

>S~roi:>lil'l~f &.G911~C;:tioh Fr~<1u.ei:i¢Y. *

-.:~.

. *ti'P,~.~~t~~~'.Y~.i~

T-~:*i:!;l.

.:/::>:: >.:a;~~,i~i*8~wil_1~ :: f. '" L.~c:a!i~~s. : *:**: * *:*::*-..* :.. _.:::.*:.~***.:r;:=:r*!*\\:_.::_:*.**:-~ ***=.*:*.*,._*::*::' ::*;. c: :**. *:,.:* }:( />. ::*:*"<.<**;: :./

1.

Gamma Dose-391 Quarterly Gamma Dose - Quarterly Environmental TLD

2.

Airborne Particulate 8 Continuous sampler - filter change Gross Beta - Every two weeks every two weeks 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 - canister 1-131 - Every two weeks change every two weeks

4.

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

5.

Sea Water 2 Continuous sampler with a monthly Gamma Isotopic and Tritium on collection at indicator location. each sample. Quarterly at control location - Composite of 6 weekly grab samples.

6.

Well Water 6 Semiannual Gamma Isotopic and Tritium on each sample

7.

Bottom Sediment 5 Semiannual Gamma Isotopic on each sample

8.

Soil 3 Annually Gamma Isotopic on each sample

9.

Fin Fish 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) Footnotes

1. Two or more TLDs or TLD with two or more elements per location.

2-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Figure 2.1, "Inner TLD, Air, Grass, Soil, and Aquatic Locations" 2-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 2-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 2.2 Samples Collected During Report Period The following table summarizes the number of samples of each type collected and analyzed during 2015: Gamma Exposure 156 156 20 (Environmental TLD} Air Particulates 208 208 0 Air Iodine 208 208 0 Soil 3 3 0 Cow Milk 0 0 18 Well Water 12 12 15 Fruits & Vegetables 4 4 5 Broadleaf vegetation 8 8 0 Sea Water 16 16 0 Bottom Sediment 10 10 0 Aquatic Flora 0 0 20 Fish 8 ?1 0 Oysters 16 16 0 Clams 8 71 0 Lobster 8 8 0 Total All Types 665 663 78 1 Due to sample unavailability, not all required fish and clam samples could be obtained. 2-7

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 2.3 Required Samples Not Collected During the Report Period During 2015 there were two required samples not collected - one fish and one clam sample. Also, one oyster sample was collected late with less than a full sample period of collection. During the first quarter of 2015 repeated attempts to collect fish in Niantic Bay and clams in Waterford Shellfish Bed were unsuccessful. The fourth quarter oyster sample at Giant's Neck (Location #37), the control location, was collected late on January 15, 2016. Oysters are stocked in trays and the trays are placed at sampling areas for 30 to 50 days before sample collection. At the normal sample date in mid-December it was discovered that the oysters at Giant's Neck had been stolen. The oysters were replaced and they remained in location for the procedurally required minimum of 30 days. Thus, the 4th quarter sample result actually represents a sample period of the end of December and the beginning of January. \\

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015

3.

RADIOCHEMICAL RES UL TS 3.1 Summar¥ Table In accordance with the REMODCM, Section l.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. 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 replace samples from required locations when they are.not available. Medium or Pathway Sampled (Units) Direct Radiation TLD (uR!hr) Air Iodine (pCi!m 3 ) Air Particulate (pCilm 3 } Soil (pCi/g dry) Milk (pCill) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Indicator Analysis Total LLD Locations Location with HiQhest Mean Type Number Note 1 Mean Number I Distance I Mean (Range\\ Direction (Range) Gamma 176 NA 7.6 8 0.3Mi. 10.8 Dose (4.4-11.9) SE (9.6-11:6) 1-131 208 0.07 <LLD NA NA <LLD GR-B 208 0.01 0.0137 0.6Mi. 0.0145 (0.0042 - 0.023) NNW (0.0069 - 0.0226) GAMMA 32 BE-7 NA 0.0142 2 0.3Mi. 0.281 (0.084 - 0.820) s (0.096 - 0.820) Other Note2 <LLD NA NA <LLD Gammas GAMMA 3 K-40 NA 14.0 4 1.0Mi. 15.1 (13.1 -15.1) N One sample CS-137 0.18 0.34 4 1.0Mi. 0.52 (0.17 - 0.52) N One sample Other Note3 <LLD NA NA <LLD Gammas SR-89 4 10 <LLD NA NA <LLD SR-90 4 2 <LLD NA NA <LLD, GAMMA 18 K-40 NA 1261 22 10.3Mi. 1261 (1102-1379) WNW (1102 - 1379) Other Note4 <LLD NA NA <LLD Gammas 3-1 Control Locations Mean (Range) 7.5 (5.9-9.4) <LLD 0.0139 (0.0067 - 0.021) 0.117 (0.072 - 0.143) <LLD 13.8 One sample 0.34 One sample <LLD NA NA NA NA

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Medium or Pathway Sampled llUnitsl Well Water (pCi//) Fruits & Vegetables (pCilgwet) Broad Leaf Vegetation (pCi!g wet) Sea Water (pCil/) Bottom Sediment (pCi/g dry} Aquatic Flora - Note 13 (pCi!g wet) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Indicator Analysis Total LLD Locations Location with Highest Mean Type Numbe1 Note1 Mean Number I Distance I Mean (Ranael Direction (Ranael H-3 27 2000 <LLD NA NA <LLD GAMMA 27 K-40 NA 103-Note 5 78 Down-gradient 127 (91 -127) of ISFSI One sample Other Note6 <LLD NA NA <LLD Gammas GAMMA 9 K-40 NA 1.629 26 Beyond 1 O miles 1.747 (0.809 - 2.069) (0.803-3.199) Other Note? <LLD NA NA <LLD Gammas GAMMA 8 BE-7 NA 0.719 0.6Mi. 0.884 (0.485 - 0.959) NNW (0.808 - 0.959) K-40 NA 4.275 10 1.2 Mi. 5.596 (2.840 - 7.607) E (3.584 - 7.607) Other Note9 <LLD NA NA <LLD Gammas H-3 16 NA 530 - Note 10 32 On site 530 - Note 10 (205-1190) (205-1190) GAMMA 16 K-40 NA 317-Note11 32 Onsite 317-Note11 (238 -448) (238 -448) Other Note6 <LLD NA NA <LLD Gammas GAMMA 10 K-40 NA 15.5 34 4.0Mi. 17.08 (13.06 -19.94) ENE 14.22-19.94 Ac-228 NA 1.25-Note 12 31 1.8Mi. 1.24 (0.61 -2.16) NW (0.31 -2.16) Other Note3 <LLD NA NA <LLD Gammas GAMMA 20 BE-7 NA 0.203 - Note 14 29 <0.5Mi. 0.267 - Note15 (0.139 - 0.267) ENE to ESE (0.197 - 0.267) K-40 NA 6.98 32 On site 7.82 (6.02 - 9.45) (6.30 - 9.45) Ac-228 NA 0.113 - Note 16 29 <0.5 Mi. 0.123 - Note 17 (0.072 - 0.142) ENE to ESE (0.098 - 0.142) Other Note? <LLD NA NA <LLD Gammas 3-2 Control Locations Mean (Ranae) NA NA NA 1.747 (0.803 - 3.199) <LLD 1.032-Note 8 (1.021 -1.42) 3.533 (3.261 - 3.805) <LLD <LLD 282 (203-370) <LLD 15.25 (12.45 - 18.05) <LLD <LLD <LLD 6.60 (6.02 -7.11) 0.090 - Note 18 <LLD

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Medium or Pathway Sampled (Units) Fish (pCi/gwet) Oysters (pCi!g wet) Clams (pCi!g wet) Lobster (pCi/g wet) RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Indicator Analysis Total LLD Locations Location with Highest Mean Type Number Note 1 Mean Number I Distance I Mean (Range) Direction (Range) GAMMA 7 K-40 NA 4.41 32 <0.5Mi. 5.16 (3.78-5.31) (5.00 - 5.31) other Note 19 <LLD NA NA <LLD Gammas GAMMA 16 K-40 NA 2.18 31 1.8 Mi. 2.33 (1.54 -2.78) NW (2.23 - 2.52) Other Note 19 <LLD NA NA <LLD Gammas GAMMA 7 K-40 NA 2.22 29 <0.5Mi. 2.30 (1.77 -2.78) ENE to ESE (1.77 - 2.78) Other Nole 19 <LLD NA NA <LLD Gammas GAMMA 8 K-40 NA 2.83 35 <0.5Mi. 2.83 (2.36 - 3.12) SSWtoW (2.36 - 3.12) other Note 19 <LLD NA NA <LLD Gammas NOTES FOR

SUMMARY

TABLE Control Locations Mean (Rangel NA NA 2.34 (2.20 - 2.58) <LLD NA NA 2.92 (2.54 - 2.69) NA 1 - The required LLD. LLD is the smallest concentration *of radioactivity that will be detected with 95% confidence that the activity is real. See detailed discussion below. 2 - LLDs for air particulate other gamma are 0.05 pCi/M3 for Cs-134 and 0.06 pCi/M3 for Cs-137. 3 - LLD for soil and sediment other gamma is 0.15 pCi/g for Cs-134. 4 - LLDs for milk other gamma are 1 pCi/I for 1-131, 15 pCi/I for Cs-134, 18 pCi/I for Cs-137, 70 pCi/I for Ba-140 and 25 pCi/I for La-140. 5 - Mean and range for three well sample results with positive K-40. All other sample results were less than LLD. 6 - LLDs for water other gamma are 15 pCi/I for Mn-54, Co-58, Co-60, Nb-95, 1-131, Cs-134 and La-140; 30 pCi/I for Fe-59, Zn-65 and Zr-95; 18 pCi/I for Cs-137 and 60 pCi/I for Ba-140. 7 - LLDs for fruits & vegetables, broadleaf vegetation and aquatic flora for other gamma are 0.06 pCi/M3 for 1-131, 0.06 pCi/M3 for Cs-134 and 0.08 pCi/M3 for Cs-137. 8 - Mean and range for two vegetation sample results with positive Be-7. Other two sample results were less than LLD. 9 - LLDs for other gamma are 0.06 pCi/g for Cs-134 and 1-131. 10 - Mean and range for nine seawater sample results with positive H-3. Other seven sample results were less than LLD. 11 - Mean and range for eleven seawater sample results with positive K-40. Other five sample results were less than LLD. 3-3

Dominion Nuclear Connecticut, Inc. Millstone Power Station NOTES FOR

SUMMARY

TABLE (Continued} Annual Radiological Environmental Operating Report 2015 12.J Mean and range for four sediment sample results with positive Ac-228. Other six sample results were less than LLD. 13 - All aquatic flora locations are extra, non-required samples with Locations 29, 32 and 35 treated as indicators and Location 36 as a control. Location 90 is a special location which is downstream from the New London water treatment plant. Although it is not influenced by any Millstone releases, at times it will detect radioactivity released from the water treatment plant. Results from Location 90 are in Table 16 but not included here. 14 - Mean and range for six aquatic flora sample results with positive Be-7. Other ten sample results were less than LLD. 15 - Mean and range for two aquatic flora sample results with positive Be-7. Other two sample results . were less than LLD. 16 - Mean and range for six aquatic flora sample results with positive Ac-228. other six sample results were less than LLD. 17 - Mean and range for three aquatic flora sample results with positive Ac-228. One other sample result was less than LLD. 18 - Value for one aquatic flora sample result with positive Ac-228. Other three sample results were less than LLD. 19 - LLDs for fish and shellfish for gammas are 0.13 pCi/g for Mn-54, Co-58, Co-60 ana Cs-134; 0.26 pCi/g for Fe-59 and Zn-65; and 0.15 pCi/g for Cs-137. Discussion of LLD 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 (-AL~.t)

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) is the radioactive decay constant for the particular radionuclide A.t 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 were 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. 3-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station 3.2 Data Tables Annual Radiological Environmental Operating Report 2015 The data reported in this section are results of analyes on all samples. Positive results are shown as bolded type. Results are considered positive when the measured value exceeds 1.5 times the listed 2cr error (i.e., the measured value exceeds 3cr). The reported error is two times the _standard deviation (2cr) 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. 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). Data are given according to sample type as indicated below.

1. Gamma Exposure Rate

2. Air Particulates, Gross Beta Radioactivity

3. Air Particulates, Airborne 1-131

4. Air Particulates, Gamma Spectra

5. Soil

6. Milk

7. WellWater

8. Fruits & Vegetables

9. Broad Leaf Vegetation

10. Seawater

11. Bottom Sediment

12. Aquatic Flora (Fucus)

13. Fin Fish

14. Oysters

15. Clams

16. Lobster 3-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station PERIOD 1Q 2Q 3Q 4Q PERIOD 1Q 2Q 3Q 4Q PERIOD 1Q 2Q 3Q 4Q PERIOD 1Q 2Q 3Q 4Q 1 (+/~) 7.2 0.6 7.8 0.5 8.0 0.6 8.1 0.6 12X (+/-) 6.6 0.7 7.0 0.4. 7.2 0.8 7.3 0.6 46 (+/-) 6.5 0.8 8.7 0.6 7.7 0.7 8.7 0.8 59 (+/-) 6.7 0.6 7.9 0.5 7.7 0.7 7.9 0.6 2 (+/-) 9.2 0.8 9.9 0.5 9.4 0.9 9.9 0.7 13C (+/-) 7.0 0.6 8.5 0.7 8.2 0.7 9.4 0.9 47 (+/-) 6.8 0.8 7.5 0.7 7.4 0.7 8.1 0.6 60 (+/-) 5.9 0.6 6.9 0.4 6.7 0.5 6.5 0.5 Annual Radiological Environmental Operating Report 2015 TABLE 1 QUARTERLY GAMMA EXPOSURE RATE (uR/hr)* LOCATIONS (C =control, background locations; X =extra locations not required by REMODCM) 3 (+/-) 6.6 0.5 6.8 0.6 7.4 0.6 8.2 0.6 14C (+/-) 7.3 0.5 9.1 0.5 8.6 0.6 9.2 0.7 48 (+/-) 8.2 0.8 9.4 0.6 9.1 0.7 9.8 0.8 61 (+/-) 6.0 0.4 7.0 0.8 7.3 0.8 7.3 0.5 4 (+/-) 6.9 0.7 7.4 0.5 7.0 0.8 8.0 0.6 15C (+/-) 6.7 0.7 7.4 0.4 7.4 0.6 8.5 0.5 49 (+/-) 6.0 0.6 6.8 0.5 6.6 0.6 6.9 0.5 62 (+/-) 6.6 0.7 7.9 0.5 7.9 0.6 8.0 0.8 5 (+/-) 8.2 0.8 9.3 6.6 9.4 0.9 9.6 0.9 16C (+/-) 5.7 0.6 6.1 0.5 5.9 0.4 6.5 0.6 50 (+/-) 6.6 0.7 7.3 0.5 7.2 0.5 7.8 0.8 63 (+/-) 7.5 0.8 8.2 0.5 8.4 0.9 8.3 1.2 6 (+/-) 8.3 0.7 8.7 0.4 8.4 0.6 9.1 0.6 27 (+/-) 8.6 1.2 7.1 0.5 7.1 0.8 8.0 0.6 51 (+/-) 5.6 0.4 6.0 0.6 5.9 0.4 6.4 0.5 64 (+/-) 6.6 0.7 7.3 0.7 7.5 0.6 7.2 0.6 7 (+/-) 6.1 0.5 4.9 0.3 4.4 0.4 5.1 0.4 41 (+/-) 6.3 0.5 6.3 0.3 6.2 0.6 6.7 0.8 52 (+/-) 6.2 0.7 7.1 0.6 6.8 0.8 7.5 0.6 65 (+/-) 6.8 0.6 8.0 0.8 7.8 0.5 8.0 0.7 8 (+/-) 9.6 0.8 11.3 0.7 10.9 0.8 11.6 0.9 42 (+/-) 5.8 0.6 7.1 0.4 7.0 0.7 7.7 0.6 53 (+/-) 6.3 0.6 7.1 0.5 6.9 0.5 7.6 0.6 66X (+/-) 7.0 0.6 7.1 0.4 7.2 0.6 7.5 0.6

READINGS ARE THE AVERAGE OF MUL Tl CaSo4(Tm) PHOSPHOR ELEMENTS WITHIN ONE PANASONIC TLD BADGE ERRORS ARE TWO SIGMA AND INCLUDE COUNTING, TRANSIT, READER AND FADE UNCERTAINTIES 3-8 9

(+/-) 9.1 1.0 11.3 0.9 11.0 0.8 11.9 0.9 43 (+/-) ~.5 0.5 7.3 0.8 6.9 0.6 7.4 0.5 55 (+/-) 7.2 0.6 7.2 0.6 6.9 0.6 7.4 0.5 73X (+/-) 7.3 1.0 7.6 0.6 7.8 0.7 8.2 0.7 10 (+/-) 9.4 0.7 9.1 0.5 8.1 0.8 9.2 0.6 44 (+/-) 7.8 0.6 7.9 0.5 7.4 0.9 8.6 0.7 56 (+/-) 6.5 0.5 6.9 1.2 6.6 0.6 7.2 0.6 74X (+/-) 6.6 0.6 7.6 0.5 7.5 0.6 7.7 0.6 11 (+/-) 6.1 0.8 7.0 0.5 6.4 0.5 7.3 0.6 45 (+/-) 6.6 0.7 7.1 0.5 7.1 0.7 7.7 0.7 57 (+/-) 6.0 0.6 7.2 0.5 7.2 0.7 7.1 0.6 75X (+/-) 6.2 0.5 6.6 0.4 6.7 0.6 6.9 0.5

Dominion Nuclear Connecticut, Inc. Millstone Power Station PERIOD ENDING 01/13/15 01/26/15 02/10/15 02/24/15 03/10/15 03/24/15 04/07/15 04/21/15 05/05/15 05/19/15 06/02115 06/16/15 06/30/15 07/14/15 07/28/15 08/11/15 08/25/15 09/08/15 09/22/15 10/06/15 10/20/15 11/03/15 11/17/15 12/01/15 12/15/15 12/29/15 01

----------r+t:;--*

0.016 0.002 0.014 0.002 0.016 0.002 0.018 0.002 0.018 0.002 0.010 0.002 0.013 0.002 0.019 0.002 0.007 0.002 0.021 0.002 0.012 0.002 0.010 0.002 0.010 0.002 0.010 0.002 0.013 0.002 0.013 0.002 0.016 0.002 0.022 0.002 0.019 0.002 0.010 0.002 0.012 0.002 0.015 0.002 0.018 0.002 0.012 0.002 0.023 0.002 0.011 0.002 02

f+i'..r-*

0.015 0.002 0.013 0.002 0.015 0.002 0.018 0.002 0.018 0.002 0.011 0.002 0.012 0.002 0;011 0.002 0.006 0.002 0.015 0.002 0.010 0.002 0.006 0.001 0.006 0.001 0.010 0.002 0.010 0.002 0.014 0.002 0.013 0.002 0.020 0.002 0.017 0.002 0.010 0.002 0.012 0.002 0.012 0.002 0.017 0.002 0.015 0.002 0.021 0.002 0.010 0.002 Annual Radiological Environmental Operating Report 2015 TABLE 2 AIR PARTICULATES GROSS BETA RADIOACTIVITY (pCi/m3) LOCATIONS (C =control, background location) 03

r+1.r--

o.014 0.002 0.012 0.002 0.014 0.002 0.021 0.002 O.Q18 0.002 0.012 0.002 0.014 0.002 0.010 0.002 0.005 0.002 0.016 0.002 0.011 0.002 0.006 0.002 0.007 0.002 0.013 0.002 0.012 0.002 0.014 0.002 0.012 0.002 0.021 0.003 O.Q18 0.002 0.009 0.002 0.013 0.002 0.016 0.002 0.018 0.002 0.011 0.002 0.021 0.002 0.008 0.002 04

----------(+i:;--*

0.014 0.002 0.012 0.002 0.015 0.002 0.019 0.002 0.021 0.003 0.011 0.002 0.016 0.002 0.010 0.002 0.005 0.001 0.017 0.002 0.010 0.002 0.008 0.002 0.007 0.002 0.014 0.002 0.011 0.002 0.015 0.002 0.015 0.002 0.023 0.003 0.019 0.002 0.010 0.002 0.012 0.002 0.013 0.002 0.019 0.002 0.012 o.qo2 0.021 0.002 0.010 0.002 3-9 10

f+i'..r-*

0.015 0.002 0.013 0.002 0.015 0.002 0.020 0.002 0.020 0.002 0.012 0.002 0.014 0.002 0.009 0.002 0.008 0.002 0.015 0.002 0.011 0.002 0.009 0.002 0.007 0.002 0.012 0.002 0.011 0.002 0.015 0.002 0.012 0.002 0.019 0.002 0.017 0.002 0.008 0.002 0.011 0.002 0.012 0.002 0.017 0.002 0.013 0.002 0.021 0.002 0.010 0.002 11

(+1.;---

0.015 0.002 0.014 0.002 0.015 0.002 0.018 0.002 0.021 0.002 0.011 0.002 0.015 0.002 0.010 0.002 0.007 0.002 0.018 0.002 0.014 0.002 0.008 0.002 0.008 0.002 0.012 0.002 0.013 0.002 0.013 0.002 0.016 0.002 0.020 0.002 0.019 0.002 0.010 0.002 0.011 0.002 0.013 0.002 0.017 0.002 0.012 0.002 0.023 0.002 0.010 0.002 27

---------(+i~}--*

0.014 0.002 0.015 0.002 0.016 0.002 0.017 0.002 0.020 0.002 0.012 0.002 0.015 0.002 0.011 0.002 0.004 0.001 O.Q18 0.002 0.014 0.002 0,.007 0.001 0.008 0.002 0.012 0.002 0.011 0.002 0.012 0.002 0.015 0.002 0.021 0.002 0.017 0.002 0.009 0.002 0.011 0.002 0.014 0.002 0.019 0.002 0.012 0.002 0.023 0.002 0.013 0.002 15C

,+,:r-*

0.014 0.002 0.013 0.002 0.013 0.002 0.020 0.002 0.019 0.002 0.013 0.002 0.014 0.002 0.009 0.002 0.007 0.002 0.019 0.002 0.011 0.002 0.008 0.002 0.011 0.002 0.012 0.002 0.013 0.002 0.014 0.002 0.014 0.002 0.021 0.003 0.017 0.002 0.012 0.002 0.012 0.002 0.015 0.002 0.017 0.002 0.014 0.002 0.020 0.002 0.011 0.002

Dominion Nuclear Connecticut, Inc. Millstone Power Station PERIOD ENDING 01/13/15 01/26/15 02/10/15 02/24/15 03/10/15 03/24/15 04/07/15 04/21/15 05/05/15 05/19/15 06/02/15 06/16/15 06/30/15 07/14/15 07/28/15 08/11/15 08/25/15 09/08/15 09/22/15 10/06/15 10/20/15 11/03/15 11/17/15 12/01/15 12/15/15 12/29/15 01

i~i~l----

0.006 0.007 0.000 O.Q15 -0.011 -0.001 -0.006 -0.022 0.006 0.004 -0.005 0.000 -0.003 0.021 0.002 0.003 -0.004 0.005 0.008 -0.001 -0.003 -0.002 0.002 -0.007 -0.014 0.011 -0.010 0.007 0.028 0.006 0.030 0.020 0.017 0.011 0.014 0.017 0.010 0.029 0.011 0.007 0.006 0.023 0.025 0.010 0.019 0.011 0.024 0.034 0.028 0.022 0.023 0.030 02

----------~i=i*--

0.007 0.008 0.000 O.Q18 -0.014 -0.001 -0.006 -0.025 0.007 0.011 -0.006 0.000 -0.003 0.021 0.002 0.003 -0.004 0.005 0.008 -0.001 -0.003 -0.002 0.002 -0.007 -O.Q15 0.011 -0.010 0.007 0.036 0.007 0.035 0.022 0.019 0.032 0.016 0.017 0.010 0.029 0.011 0.008 0.006 0.023 0.026 0.009 0.019 O.Q11 0.024 0.035 0.028 0.022 0.024 0.030 Annual Radiological Environmental Operating Report 2015 TABLE 3 AIRBORNE IODINE (1-131) (pCi/m3) LOCATIONS (C =control, background location) 03

----------i;i-i __ _

0.006 0.007 0.000 0.015 -0.012 0.030 -0.001 0.006 -0.006 0.030 -0.022 0.020 0.006 0.017 0.009 0.028 -0.005 O.Q15 -0.001 0.019 -0.003 0.012 0.023 0.032 0.002 0.013 0.004 0.009 -0.005 0.007 0.006 0.027 0.009 0.030 -0.001 0.011 -0.004 0.022 -0.002 0.012 0.002 0.029 -0.009 0.041 -0.016 0.031 0.011 0.023 -0.011 0.025 0.007 0.032 04

(.;:ff*-*

0.007 0.008 0.000 0.018 -0.015 -0.001 -0.007 -0.026 0.007 0.010 -0.005 -0.001 -0.003 0.022 0.002 0.004 -0.005 0.006 0.009 -0.001 -0.003 -0.002 0.002 -0.008 -0.016 0.012 -0.011 -0.010 0.036 0.007 0.036 0.024 0.020 0.030 0.014 0.018 0.011 0.031 0.012 0.008 0.006 0.026 0.028 0.010 0.021 0.012 0.027 O.Q38 0.031 0.024 0.026 0.031 3-10 10

(.;:i_r--*

-0.004 0.008 0.010 0.016 0.003 0.003 0.003 -0.002 0.007 0.010 0.007 -0.011 0.014 0.002 0.001 0.010 0.002 -0.019 0.016 0.000 -0.010 0.001 -O.D18 -0.012 -0.001 0.001 -0.018 -0.009 0.033 0.006 0.033 0.Q18 0.010 0.028 0.015 O.Q18 0.019 0.034 0.005 0.008 0.007 0.039 0.028 0.003 0.019 0.010 0.029 0.034 0.027 0.032 0.036 0.027 11

(;ff*-*

-0.003 0.008 0.009 O.Q15 0.003 0.030 0.003 0.005 0.002 0.029 -0.002 0.016 0.006 0.009 0.004 0.025 0.006 0.014 -0.010 0.017 0.013 0.017 0.002 0.030 -0.002 0.010 0.009 0.008 0.002 0.006 -0.017 0.033 O.Q18 0.031 -0.002 0.011 -0.011 0.021 0.001 0.011 -0.020 0.032 -0.013 0.038 -0.002 0.029 0.001 0.035 -0.020 0.039 -0.009 0.029 27

i~i~,----

-0.004 0.009 0.011 0.018 0.004 0.003 0.003 -0.003 0.008 0.005 0.006 -0.010 0.015 0.002 -0.002 0.009 0.002 -0.017 .0.018 -0.002 -0.011 0.001 -0.021 -0.013 -0.002 0.001 -0.019 -0.005 0.040 0.006 0.037 0.020 0.011 0.033 O.Q15 O.Q18 0.020 0.027 0.010 0.008 0.006 0.034 0.032 0.011 0.021 0.011 0.033 0.038 0.029 0.036 0.038 O.Q16 15C

----------r.. iT--

-0.004 0.008 0.010 0.016 0.003 0.034 0.003 0.006 0.003 0.035 -0.003 0.020 0.007 0.011 0.004 0.028 0.006 0.014 -0.010 0.017 0.013 0.017 0.002 0.029 -0.002 0.011 0.009 0.008 0.002 0.006 -O.Q18 0.035 0.018 0.033 -0.002 0.012 -0.012 0.022 0.001 0.011 -0.021 0.033 -0.014 0.040 -0.002 0.030 0.001 0.036 -0.020 0.040 -0.010 0.031

Dominion Nuclear Connecticut, Inc. Millstone Power Station LOCATION Be-7

(+7:,-----

01 0.0966 0.0297 02 0.1600 0.0575 03 0.1307 0.0433 04 0.0875 0.0735 10 0.1176 0.0531 11 0.1253 0.0420 27 0.1907 0.0667 15C 0.1265 0.0409 LOCATION Ru-103

(+7:,-----

01 0.0007 0.0041 02 0.0407 0.0531 03 -0.0034 0.0057 04 0.0002 0.0093 10 0.0004 0.0061 11 -0.0059 0.0059 27 -0.0048 0.0088 15C -0.0017 0.0040 LOCATION Be-7

(+7:,-----

01 0.1016 0.0428 02 0.1069 0.0277 03 0.1275 0.0537 04 0.1406 0.0476 10 0.1192 0.0507 11 0.1099 0.0413 27 0.1061 0.0382 15C 0.1433 0.0394 LOCATION Ru-103

(+1:,*---*

01 0.0022 0.0037 02

0.0013 0.0049 03 0.0065 0.0074 04

-0.0023 0.0055 10 0.0042 0.0080 11 . *0.0006 0.0035 27

0.0012 0.0041 15C

-0.0057 0.0055 Annual Radiological Environmental Operating Report 2015 TABLE4 AIR PARTICULATES (pCi/m3) (15C =control, background location) GAMMA SPECTRA-QTR 1 (12/30/14 - 04/07/15) Mn-54 Co-58 Co-60 Zn-65

-----------r+r.r---*

(+i:j ____

-----------c:;:i-r---* ------------r+1:;-*--

0.0005 0.0011 0.0010 0.0019 0.0008 0.0008 0.0028 0.0029 0.0019 0.0104 -0.0077 0.0267 -0.0019 0.0098 0.0141 0.0240 0.0000 0.0017 0.0014 0.0036 0.0010 0.0012 -0.0010 0.0036 ~0.0014 0.0028 -0.0002 0.0039 -0.0016 0.0019 0.0058 0.0066 0.0007 0.0017 0.0020 0.0024 0.0013 0.0018 -0.0005 0.0041 -0.0002 0.0014 -0.0008 0.0022 -0.0005 0.0012 0.0000 0.0029 -0.0014 0.0023 -0.0035 0.0053 0.0002 0.0031 0.0009 0.0046 0.0003 0.0014 -0.0022 0.0022 0.0000 0.0009 0.0005 0.0031 Ru-106 Cs-134 Cs-137 Ba-140

-----------r;:r.r---* ------------Fr---
-----------c:;:1-r---* *-----------r+,:r*--

-0.0139 0.0131 -0.0001 0.0012 0.0003 0.0010 -0.0020 0.4906 0.0571 0.1124 0.0050 0.0103 -0.0058 0.0106 -0.9744 5.8260 0.0042 0.0133 0.0002 0.0013 0.0003 0.0015 -0.2647 0.7735 -0.0115 0.0213. 0.0028 0.0021 0.0016 0.0019 -0.1101 1.0220 0.0031 0.0145 -0.0001 0.0018 -0.0004 0.0015 0.1637 0.7549 -0.0085 0.0110 -0.0003 0.0011 -0.0003 0.0010 -0.2590 0.5423 0.0057 0.0250 0.0026 0.0024 0.0007 0.0022 -0.2331 1.1510 -0.0065 0.0100 0.0004 0.0011 -0.0011 0.0010 -0.0005 0.5666 GAMMA SPECTRA-QTR 2 (04/07/15 -06/30/15) Mn-54 Co-58 Co-60 Zn-65

-----------r+r.r---*

(+i=j ____ *-----------Fi-r---* ------------r+1:;-*--

0.0002 0.0011 -0.0018 0.0023 -0.0002 0.0013 -0.0001 0.0028 0.0001 0.0010 -0.0010 0.0026 0.0007 0.0012 0.0011 0.0036 0.0001 0.0023 0.0005 0.0050 0.0007 0.0024 0.0038 0.0065 0.0003 0.0017 0.0009 0.0032 -0.0012 0.0014 0.0015 0.0037 0.0007 0.0021 0.0011 0.0034 0.0004 0.0019 0.0036 0.0041 0.0001 0.0012 0.0006 0.0015 0.0007 0.0009 0.0003 0.0023 -0.0011 0.0015 0.0002 0.0024 0.0005 0.0011 0.0002 0.0035 0.0002 0.0016 0.0000 0.0026 0.0005 0.0016 0.0009 0.0039 Ru-106 Cs-134 Cs-137 Ba-140

----------*r+1:r*--* -----------*Fr**-
-----------<+1-r*--* ------------f+,:r*--

0.0033

0.0090 0.0007 0.0011 0.0006 0.0013 0.0007 0.3877
0.0058 0.0113 0.0008 0.0013 0.0012 0.0009
0.1350 0.4362
0.0100 0.0225 0.0020 0.0020

-0.0007 0.0020 0.0380 0.8127 0.0089 0.0105

0.0006 0.0013

-0.0003 0.0014 -0.1254 0.5343 0.0110 0.0145 0.0009 0.0017 0.0002 0.0017 0.2946 0.6238 0.0012 0.0088 0.0003 0.0011

0.0003 0.0009 0.2200 0.3246

-0.0017 0.0104 0.0019 0.0013

0.0004 0.0010
0.1183 0.4492 0.0163 0.0143 0.0015 0.0015
0.0003 0.0012 0.4738 0.4849 3-11 Nb-95 Zr-95

1+i=-,-----

-----------r+i-r*--*

-0.0001 0.0023 0.0031 0.0040 0.0175 0.0274 -0.0384 0.0464 0.0030 0.0037 -0.0035 0.0063 0.0032 0.0054 -0.0018 0.0091 0.0014 0.0035 -0.0014 0.0060 -0.0021 0.0029 0.0005 0.0049 -0.0024 0.0060 -0.0030 0.0114 0.0007 0.0027 0.0026 0.0042 Ce-141 Ce-14.4

(+i'.y----

-----------Fi-r---*

0.0023 0.0078 -0.0003 0.0057 -0.0245 0.0802 0.0383 0.0535 0.0013 0.0098 -0.0017 0.0066 -0.0053 0.0174 -0.0012 0.0127 0.0025 0.0090 -0.0071 0.0069 0.0033 0.0087 -0.0035 0.0064 0.0009 0.0124 0.0015 0.0086 0.0038 0.0082 0.0015 0.0060 Nb-95 Zr-95

1+1=-i-----

-----------Fi-r---*

-0.0004 0.0023 -0.0011 0.0037 0.0018 0.0028 -0.0073 0.0050 0.0035 0.0049 -0.0032 0.0082 0.0006 0.0035 0.0015 0.0056 -0.0004 0.0036

0.0010 0.0068

-0.0018 0.0025 0.0036 0.0039 0.0019 0.0028 0.0017 0.0049 -0.0012 0.0031 0.0013 0.0054 Ce-141 Ce-144

1+1:-i--*--

-----------Fi-r**-*

0.0083. 0.0071 0.0026 0.0054

0.0010 0.0070 0.0023 0.0057 0.0083 0.0097

-0.0028 0.0061 0.0004 0.0088 0.0023 0.0073

0.0023 0.0109 0.0003 0.0090

-0.0009 0.0066

0.0032 0.0054 0.0025 0.0072 0.0029 0.0065 0.0018 0.0096 0.0042 0.0077

Dominion Nuclear Connecticut, Inc. Millstone Power Station LOCATION Be-7

(+i~-----

01 0.1339 0.0457 02 0.0960 0.0348 03 0.1214 0.0318 04 0.1185 0.0426 10 0.1136 0.0321 11 0.0862 0.0288 27 0.1839 0.0422 15C 0.1264 0.0549 LOCATION Ru-103

(+i~-----

01 -0.0027 0.0069 02 0.0012 0.0041 03 0.0009 0.0042 04 -0.0005 0.0041 10 0.0043 0.0042 11 0.0000 0.0051 27 -0.0069 0.0039 15C 0.0004 0.0077 LOCATION Be-7

(+i~-----

01 0.0940 0.0301 02 0.1001 0.0361 03 0.0843 0.0381 04 0.0961 0.0422 10 0.1010 0.0352 11 0.1020 0.0298 27 0.1090 0.0338 15C 0.0717 0.0312 LOCATION Ru-103

(+i=,-----

01 -0.0002 0.0037 02 -0.0032 0.0070 03 0.0019 0.0043 04 0.0003 0.0042 10 -0.0019 0.0048 11 -0.0014 0.0039 27 -0.0013 0.0034 15C 0.0004 0.0032 Annual Radiological Environmental Operating Report 2015 TABLE4 AIR PARTICULATES (pCi/m3) GAMMA SPECTRA-QTR 3 (06/30/15 - 10/06/15) Mn-54 Co-58 Co-60 Zn-65

-----------r+i-r---*

(+i:r---

-----------Fi~-----

r+q----

-0.0006 0.0018 -0.0013 0.0035 -0.0004 0.0014 0.0027 0.0037 0.0004 0.0011 -0.0010 0.0022 0.0002 0.0009 0.0029 0.0030 -0.0002 0.0010 0.0015 0.0024 0.0007 0.0010 0.0019 0.0040 -0.0011 0.0009 -0.0004 0.0022 -0.0010 0.0010 -0.0017 0.0030 -0.0007 0.0010 -0.0004 0.0026. 0.0011 0.0012 0.0017 0.0033 -0.0005 0.0012 -0.0013 0.0025 -0.0001 0.0013 0.0038 0.0032 -0.0002 0.0011 0.0002 0.0025 -0.0006 0.0008 -0.0012 0.0027 -0.0008 0.0019 -0.00'20 0.0031 0.0014 0.0016 0.0015 0.0045 Ru-106 Cs-134 Cs-137 Ba-140

-----------r+i-r---*

(+i:i ____ *-----------Fi-r---* ------------r+1:j ____

0.0040 0.0140 0.0025 0.0020 -0.0003 0.0015 -0.0247 0.8042 0.0081 0.0094 0.0008 0.0012 -0.0001 0.0010 -0.0282 0.3596 0.0035 0.0101 0.0035 0.0014 0.0010 0.0010 -0.1019 0.5216 -0.0010 0.0105 -0.0010 0.0012 0.0010 0.0011 -0.0016 0.4223 -0.0062 0.0114 0.0013 0.0012 -0.0004 0.0010 0.0965 0.5611 -0.0017 0.0107 0.0008 0.0011 0.0000 0.0008 0.0875 0.6066 -0.0028 0.0115 -0.0003 0.0011 0.0008 0.0012 -0.1457 0.5858 -0.0051 0.0147 0.0005 0.0018 -0.0010 0.0018 0.0188 0.8558 GAMMA SPECTRA-QTR 4 (10/06/15 - 12/29/15) Mn-54 Co-58 Co-60 Zn-65

-----------f+i-r---*

(+i:i ____ *-----------Fi-r---* ------------r+q----

0.0004 0.0014 0.0017 0.0019 0.0005 0.0011 0.0022 0.0030 -0.0004 0.0020 0.0006 0.0033 -0.0008 0.0023 0.0062 0.0057 0.0003 0.0011 -0.0028 0.0027 0.0022 0.0016 -0.0033 0.0036 0.0000 0.0014 -0.0014 0.0029 -0.0012 0.0013 0.0017 0.0033 0.0004 0.0018 0.0010 0.0031 0.0004 0.0013 0.0021 0.0045 -0.0001 0.0012 -0.0006 0.0026 -0.0002 0.0013 -0.0007 0.0030 0.0005 0.0012 -0.0008 0.0014 0.0004 0.0005 -0.0004 0.0026 0.0001 0.0011 -0.0016 0.0020 -0.0002 0.0009 0.0034 0.0029 Ru-106 Cs-134 Cs-137 Ba-140

-----------f+i-r---*

(+i:r---

-----------Fi-r---* ------------r+,:r---

0.0032 0.0119 0.0014 0.0012 0.0002 0.0010 0.0238 0.2170 0.0035 0.0201 0.0015 0.0019 0.0007 0.0020 -0.2509 0.3692 0.0052 0.0115 -0.0001 0.0014 -0.0005 0.0013 -0.0790 0.2377 -0.0101 0.0128 0.0013 0.0013 0.0002 0.0012 0.1546 0.2243 -0.0045 0.0145 0.0006 0.0019 0.0006 0.0014 -0.1319 0.3111 -0.0110 0.0116 0.0005 0.0011 0.0009 0.0011 -0.0540 0.2216 0.0009 0.0087 -0.0005 0.0010 0.0002 0.0008 0.0260 0.2191 0.0084 0.0086 -0.0005 0.0009 0.0007 0.0009 0.1427 0.1942 3-12 Nb-95 Zr-95

(+j:,-----

-----------Fi-r---*

-0.0011 0.0036 -0.0036 0.0063 0.0018 0.0021 0.0009 0.0040 0.0017 0.0026 -0.0021 0.0046 0.0012 0.0028 -0.0010 0.0044 0.0020 0.0028 -0.0017 0.0052 0.0002 0.0029 0.0003 0.0051 -0.0006 0.0026 -0.0028 0.0051 0.0022 0.0045 -0.0024 0.0077 Ce-141 Ce-144

(+i=,-----

-----------,+i-r---*

-0.0034 0.0098 0.0013 0.0074 -0.0006 0.0071 -0.0011 0.0047 -0.0050 0.0082 0.0010 0.0059 -0.0040 0.0082 -0.0049 0.0054 -0.0002 0.0080 0.0017 0.0055 0.0007 0.0086 0.0000 0.0062 -0.0028 0.0077 -0.0031 0.0056 -0.0035 0.0105 0.0038 0.0076 Nb-95 Zr-95

(+i=,-----

-----------(+i-i ____,

-0.0010 0.0021 0.0015 0.0036 -0.0009 0.0035 -0.0002 0.0067 -0.0015 0.0031 0.0039 0.0042 0.0006 0.0026 0.0004 0.0048 -0.0004 0.0032 -0.0019 0.0057 -0.0001 0.0023 0.0044 0.0044 -0.0007 0.0018 -0.0006 0.0029 0.0005 0.0021 -0.0010 0.0040 Ce-141 Ce-144

(+i~-----

-----------,+i-r---*

0.0031 0.0065 -0.0031 0.0068 0.0104 0.0081 -0.0075 0.0085 -0.0076 0.0075 0.0051 0.0074 -0.0018 0.0063 -0.0029 0.0059 -0.0020 0.0077 -0.0008 0.0081 -0.0025. 0.0064 -0.0032 0.0071 0.0010 0.0053 -0.0013 0.0054 0.0028 0.0055 0.0011 0.0052

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Be-7 (+/-) 03 11/03/15 0.120 0.534 04 11/03/15 0.084 0.777 14C 11/03/15 0.323 0.820 (14C =control, background location) COLLECTION LOCATION DATE Co-60 (+/-) 03 11/03/15 -0.027 0.051 04 11/03/15 -0.042 0.084 14C 11/03/15 -0.061 0.076 COLLECTION LOCATION DATE Sb-125 (+/-) 03 11/03/15 0.030 0.130 04 11/03/15 0.127 0.172 14C 11/03/15 .0.140 0.248 Annual Radiological Environmental Operating Report 2015 TABLE 5 SOIL (pCi/g dry wt.) K-40 Cr-51 Mn-54 (+/-) (+/-) (+/-) 13.100 1.587 -0.122 0.599 0.008 0.054 15.110 3.027 -1.040 0.932 0.031 0.098 13.750 2.354 0.038 0.999 0.009 0.080 Zn-65 Nb-95 Zr-95 (+/-) (+/-) (+/-) 0.022 0.130 0.030 0.058 0.144 0.099 -0.325 0.195 0.048 0.107 -0.074 0.211 -0.096 0.215 0.111 0.096 -0.030 0.164 .cs-134 Cs-137 Ce-141 (+/-) (+/-) (+/-) -0.023 0.057 0.167 0.080 0.001 0.116 -0.029 0.092 0.517 0.155 0.072 0.167 -0.073 0.096 0.338 0.185 -0.121 0.178 Co-58 Fe-59 (+/-) (+/-) -0.016 0.051 -0.040 0.124 -0.036 0.099 0.037 0.208 0.046 0.087 0.077 0.183 Ru-103 Ru-106 (+/-) (+/-) 0.019 0.061 0.028 0.442 0.030 0.112 -0.112 0.711 -0.024 0.096 -0.042 0.708 Ce-144 Ac-228 (+/-) (+/-) -0.551 0.388 1.076 0.370 -0.464 0.544 0.720 0.832 0.187 0.608 0.347 0.642 Note: Extra counts detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. 3-13 Note

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE 1-131

*-----------* *----------Fi-r--*

22 01/21/15 -0.132 0.083 02/18/15 -0.211 0.148 03/11/15 0.133 0.223 04/15/15 -0.526 0.347 05/13/15 -0.208 0.322 05/27/15 -0.441 0.206 06/10/15 -0.171 0.345 06/22/15 -0.303 0.199 07/08/15 0.006 0.211 07/23/15 -0.179 0.139 08/12/15 -0.119 0.190 08/26/15 . -0.571 0.499 09/16/15 -0.298 0.349 09/28/15 -0.157 0.458 10/13/15 -0.069 0.196 10/27/15 -0.638 0.224 11/18/15 0.092 0.415 12/08/15 -0.220 0.248 Annual Radiological Environmental Operating Report 2015 TABLE 6 COW MILK (pCi/I) Sr-89 Sr-90 K-40 Cs-134 Cs-137

(+i-)" --------f+t=i* *---------r;-,:j--

,+!~)----- -----------T+tT ___

1226 120 0.711 3.973 2.946 3.538 1295 205 -6.748 6.098 4.754 6.112 4.9 2.7 0.7 1.3 1352 178 2.921 4.703 -2.471 4.336 1203 112 0.668 2.987 1.238 2.898 1249 186 5.351 7.164 2.682 6.240 1224 170 -0.256 4.364 3.123 4.349 1254 192 0.177 4.933 1.279 5.281 3.1 4.0 0.0 0.9 1186 185 -5.860 5.091 0.312 5.231 1360 148 -1.967 3.710 -0.162 3.364 1212 153 -2.154 5.144 2.243 4.211 1217 188 -3.266 6.888 -0.891 7.155 1373 237 -1.491 6.586 -0.996 5.847 1379 250 -10.330 6.599 0.381 6.839 7.4 5.9 0.5 0.4 1102 174 -3.461 4.465 0.011 4.768 1314 214 4.950 5.419 -1.614 5.318 1251 201 -3.238 4.829 0.986 5.200 1211 213 -3.238 7.696 0.168 7.672 4.7 3.2 0.7 0.7 1284 127 -0.693 2.780 -0.967 3.165 3-14 Ba-140 La-140

-----------,+i-r---- *-----------f +r-r---

-10.800 15.650 1.426 5.418 21.580 29.690 -2.854 9.028 -3.004 24.780 2.192 5.964 -1.231 14.630 2.791 5.011 28.800 28.500 6.665 9.012 3.913 22.070 -0.041 4.513 -7.014 24.410 4.429 6.763 -5.341 21.110 -0.136 6.032 11.170 15.530 -0.486 3.898 1.566 20.320 1.918 6.529 -10.020 29.930 -2.299 7.536 -8.&77 28.100 4.742 9.184 -1.172 31.820 0.275 7.201 -2.659 23.600 5.516 8.152 8.551 22.390 -1.510 6.276 -3.325 23.210 3.736 5.861 20.710 24.980 4.292 7.229 11.850 12.990 -2.151 4.244

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE H-3

F-i-Y-71 06/23/15 246 513 09/22/15

-184 502 12/10/15 -83 556 72 06/22/15 534 523 09/21/15 13 518 12/09/15 476 595 76 06/18/15 83 491 09/15/15 368 593 12/07/15 -586 590 77 06/18/15 573 530 09/15/15 165 579 12/07/15 45 565 78 06/18/15 438 514 09/15/15 -32 563 12/07/15 488 740 79 06/22/15 523 529 09/21/15 438 551 12/09/15 548 602 81 06/22/15 749 546 09/21/15 89 524 12/10/15 388 591 82 06/22/15 677 540 09/22/15 -419 481 12/10/15 216 577 83 06/22/15 544 528 09/21/15 -362 486 12/10/15 13 561 Annual Radiological Environmental Operating Report 2015 TABLE 7 WELL WATER (pCi/I} Be-7 K-40 Cr-51 Mn-54 Co-58

r+i-r-

---------Ft:;--*

F-i-Y-

Fr*

---------(+7:y-*

-31.2 32.7 -44.3 53.8 -39.3 32.5 3.9 3.3 -0.5 4.3 22.9 33.1 37.8 41.3 -9.7 35.3 -2.2 4.0 -3.4 3.4 13.0 28.6 54.7 47.1 -36.7 31.3 0.2 2.7 0.3 3.3 -7.9 29.4 6.4 38.7 -14.8 33.1 -1.8 3.4 -1.1 3.4 23.8 42.0 -7.3 67.5 6.0 52.3 -1.6 5.0 -0.1 4.7 19.1 23.9 11.6 49.9 -2.8 28.2 -2.6 2.7 0.9 2.6 12.8 31.4 -8.25 49.48 -49.3 36.5 -0.8 3.48 -0.46 3.68 -30.9 48.6 48.2 104.6 39.6 49.5 -3.3 6.2 0.0 6.0 -20.6 44.3 -5.1 80.9 2.1 53.8 -5.0 6.9 -0.8 5.4 -17.2 33.2 -5.7 53.8 5.3 37.3 1.1 4.4 0.9 4.0 -46.0 41.1 29.2 71.4 0.3 53.8 4.0 4.9 -0.2 5.0 16.6 48.8 56.9 92.3 29.9 50.2 -6.4 6.0 -6.5 6.8 1.38 27.2 127 61.56 -10.5 32.1 -0.23 2.94 2.23 3.31 7.0 34.8 48.6 82.0 -10.5 36.6 -0.1 4.6 -3.6 4.1 -33.2 54.3 -10.0 78.7 -40.5 53.4 -6.2 6.6 2.0 5.8 -2.2 34.4 34.9 70.2 -2.2 33.9 -0.6 3.4 -0.4 3.7 -15.2 35.1 -29.7 60.0 -31.7 42.5 -1.8 3.5 -1.0 4.2 -11.6 24.9 12.6 35.8 11.5 32.7 -1.0 2.2 -2.3 2.4 4.4 34.8 -33.9 65.2 -11.4 40.0 -1.2 3.2 -0.4 4.3 10.2 46.9 64.6 82.4 23.8 55.1 0.2 4.7 0.6 5.3 -6.5 23.7 18.9 52.5 -29.0 29.9 0.7 2.7 -1.3 2.6 -33.7 38.9 4.6 75.8 25.1 44.5 -4.5 4.3 -3.2 4.3 -54.7 47.5 21.1 72.1 28.4 52.0 -3.3 6.2 1.6 6.9 20.4 25.1 93.2 41.7 3.6 30.1 -1.3 2.5 -2.5 3.0 17.0 35.2 -9.0 65.3 2.9 44.2 -1.3 3.7 -0.3 3.4 46.1 44.0 -78.0 65.8 -20.8 40.2 -5.4 4.8 0.4 4.7 -0.5 25.0 90.6 55.8 -0.1 29.7 0.0 2.7 -3.5 2.6 3-15 Fe-59 Co-60

--------F-ir

r+i-r*

0.5 8.2 -1.1 3.3 1.3 6.5 -0.8 3.7 0.0 6.2 0.9 2.5 -4.7 7.8 2.5 4.1 3.0 9.9 1.4 4.2 -2.3 6.8 2.2 2.7 1.12 6.33 -0.57 3.47 -5.3 12.8 -4.5 6.2 12.2 9.6 1.1 5.8 -3.9 6.8 0.8 4.1 0.9 9.9 3.0 4.3 1.2 11.1 -4.6 5.8 4.05 5.11 -0.02 2.79 -0.1 9.2 -4.7 5.4 -2.3 12.0 3.7 5.3 1.4 7.4 3.0 4.1 5.6 8.0 2.6 3.6 -0.2 3.8 -0.7 1.5 2.9 7.3 -1.0 4.5 4.4 9.0 2.4 4.0 -2.6 5.1 -0.2 2.8 2.7 7.8 0.3 3.6 -2.7 11.3 -0.2 6.7 -1.1 6.0 2.7 2.8 2.2 6.9 -2.7 4.3 3.0 9.8 3.9 4.9 4.8 5.3 1.2 2.3

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 TABLE 7 WELL WATER (pCi/I) COLLECTION LOCATION DATE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

------------* ---------Fi-r

Fi-T-

---------(i-i:y--

r+i-r*

--------T+tT.

71 06/23/15 1.9 4.9 -4.5 4.1 0.4 6.7 -4.5 4.5 14.6 41.4 09/22/15 5.6 8.7 4.2 4.4 3.7 6.4 -3.8 4.2 -0.5 34.7 12/10/15 2.4 6.1 3.7 3.1 -2.7 4.8 -3.3 3.7 2.8 27.9 72 06/22/15 -0.4 8.6 -3.0 3.7 -3.6 5.2 1.3 3.4 2.0 34.0 09/21/15 -1.8 11.5 1.0 4.9 -3.9 8.1 -4.2 5.8 -26.2 49.3 12/09/15 -2.1 4.8 0.5 2.9 1.5 4.3 -4.5 3.0 -1.4 20.5 76 06/18/15 -1.5 7.9 -0.7 4.0 -1.4 6.7 1.3 4.2 15.5 34.5 09/15/15 4.5 13.1 1.6 6.0 2.5 10.2 0.0 5.4 -7.1 43.0 12/07/15 9.2 15.2 4.1 5.8 1.0 8.3 -3.3 6.6 -24.2 56.7 77 06/18/15 -0.6 8.9 -1.8 5.0 -0.5 6.4 -0.1 4.1 -10.1 35.9 09/15/15 5.1 10.4 4.9 5.8 5.8 8.6 -4.3 6.2 -3.3 45.0 12/07/15 25.2 15.4 Note 1 9.1 8.7 -7.8 10.4 -1.0 6.1 39.6 53.7 Note 1: Zn-65 was not identified in sample. Counts in Zn-65 peak area were from naturally occuring Bi-214. 78 06/18/15 12.1 6.5 Note2 4.1 3.7 1.6 5.8 -1.7 3.6 10.9 29.2 09/15/15 -16.2 12.8 3.5 4.6 1.2 8.7 3.1 4.4 -28.8 41.0 12/07/15 -9.5 18.1 4.6 5.8 -0.9 9.7 2.3 6.6 8.5 55.9 Note 2: Result for Zn-65 was less thant the minimum detectable activity (MDA). 79 06/22/15 1.9 8.4 2.7 3.6 6.2 6.4 -4.3 3.7 -24.8 34.1 09/21/15 -17.1 11.7 4.0 4.9 -0.8 7.4 1.0 4.5 -10.1 44.2 12/09/15 -6.4 4.5 0.5 2.3 -2.5 4.3 4.2 3.2 -6.9 22.1 81 06/22/15 2.6 8.5 0.8 4.0 -3.8 6.4 -0.1 4.6 4.4 35.4 09/21/15 8.5 10.9 6.4 5.8 -4.3 8.3 -1.8 6.2 -11.6 42.3 12/10/15 2.7 5.6 2.7 2.7 -0.9 4.7 0.7 3.1 -12.5 23.9 82 06/22/15 -4.9 9.2 10.5 4.9 Note3 6.9 7.3 1.1 4.5 19.8 34.6 09/22/15 -0.1 15.9 7.7 7.2 -3.8 10.2 -2.3 5.9 -1.9 50.5 12/10/15 0.0 6.3 6.9 3.7 Note3 -2.2 5.2 -3.7 3.2 3.2 22.1 83 06/22/15 -6.3 8.7 4.3 4.5 -1.1 7.3 -2.0 4.6 15.1 35.4 09/21/15 2.7 12.4 6.7 6.3 0.5 8.3 -0.8 5.1 -23.7 42.0 12/10/15 -4.0 5.4 1.5 2.7 -1.5 5.0 -1.4 3.2 16.6 22.4 Note 3: Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. 3-16 Sb-125 1-131 Cs-134

(+i~--* ---------r+i-r-

---------c-tt:r*

-4.3 11.0 2.9 6.5 -3.3 4.7 -0.7 10.7 -5.0 5.4 0.3 3.9 -4.7 8.3 6.2 8.6 -1.2 3.2 -7.1 10.1 -0.2 5.9 1.9 3.0 0.5 13.4 6.4 7.6 -4.7 5.8 -4.4 7.0 3.9 8.0 0.1 3.5 6.0 10.6 -1.3 6.3 -1.2 3.7 -9.3 13.9 -0.9 8.1 2.3 5.0 -9.5 17.6 0.2 7.4 -0.8 7.0 -11.8 10.3 -1.3 7.1 -1.3 4.3 -5.8 13.9 -3.5 8.6 -1.0 5.8 -10.8 18.2 -5.3 7.3 -1.6 6.4 -12.4 9.3 2.9 5.9 2.5 5.4 4.5 11.6 0.2 7.1 -1.2 4.8 0.7 15.4 -5.9 7.8 4.7 5.9 4.1 ' 9.9 3.2 6.7 2.3 3.6 -8.5 13.9 1.4 6.3 3.9 5.0 -1.8 7.4 2.0 9.7 -0.6 3.0 0.1 11.3 0.6 6.6 -0.1 4.1 2.9 14.5 -3.5 8.2 3.1 5.7 2.5 7.4 3.6 7.5 0.3 2.9 -1.5 12.7 3.0 7.8 1.6 4.5 -3.4 17.2 7.2 7.9 1.0 6.5 -0.4 7.3 2.8 7.9 0.3 2.7 -5.6 11.6 -3.9 7.9 2.4 4.7 -2.0 13.8 0.3 6.6 0.1 5.6 4.1 6.9 4.3 7.9 0.9 2.8

Dominion Nuclear Connecticut, Inc. Millstone Power Station LOCATION 71 72 76 77 78 79 81 82 83 Annual Radiological Environmental Operating Report 2015 TABLE 7 WELL WATER (pCi/I) COLLECTION DATE Cs-137 Ba-140 La-140

Fi~--

Fr.r-

,+r.r-*

06/23/15 -0.5 4.1 4.6 16.5 -3.7 7.0 09/22/15 -0.9 4.2 6.1 15.8 -0.2 4.8 12/10/15 2.8 2.9 16.1 20.1 5.3 6.4 06/22/15 -1.5 3.6 -18.2 16.3 3.1 5.7 09/21/15 -4.8 5.4 -1.3 23.3 3.2 8.1 12/09/15 0.4 2.9 -0.5 16.8 -0.5. 6.0 06/18/15 -0.4 3.7 -4.5 17.0 -1.1 5.5 09/15/15 -6.0 6.4 -25.5 26.0 0.6 8.4 12/07/15 -0.3 6.9 8.4 26.0 -1.1 4.4 06/18/15 -1.4 4.1 -7.8 18.2 1.7 5.9 09/15/15 -3.0 5.6 0.2 26.5 -4.0 7.0 12/07/15 2.3 7.3 0.0 24.9 1.6 8.6 06/18/15 0.2 3.2 -4.9 16.0 -2.6 4.4 09/15/15 3.1 5.1 -3.7 19.5 -6.0 7.5 12/07/15 0.8 6.3 1.3 26.1 2.9 7.7 06/22/15 3.0 3.9 4.5 18.9 2.2 6.5 09/21/15 -2.5 4.3 0.4 19.6 3.2 5.1 12/09/15 1.3 2.4 -1.0 17.5 0.6 3.4 06/22/15 0.9 4.2 7.1 18.7 -1.7 6.9 09/21/15 -4.2 6.3 25.7 23.6 9.3 6.3 12/10/15 -0.7 2.6 0.3 17.4 4.3 5.1 06/22/15 0.3 4.7 -17.5 20.2 -0.8 6.2 09/22/15 -1.5 5.9 3.1 22.1 -0.8 8.1 12/10/15 -2.8 2.9 1.1 18.3 4.7 6.6 06/22/15 -4.6 4.7 11.5 21.1 5.6 7.4 09/21/15 -1.0 4.7 -15.9 19.5 -1.3 6.6 12/10/15 0.1 2.6 0.2 19.1 -2.7 4.6 3-17 Ac-228

--------(+i=-i-*

1.9 14.6 8.2 14.7 6.0 11.2 0.0 14.8 13.6 19.2 13.2 10.2 -9.2 14.2 11.7 21.5 -7.1 21.2 11.1 13.5 12.2 19.2 22.0 23.8 10.9 11.2 1.8 15.3 -11.4 19.7 7.8 14.2 5.6 16.7 -10.8 8.5 -2.1 14.3 '1.0 19.3 -1.8 9.5 4.2 15.4 -15.4 24.2 -2.6 10.0 -4.4 15.2 2.9 18.4 3.3 9.9

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 07/27/15 07/27/15 08/10/15 10/20/15 10/20/15 COLLECTION DATE 07/27/15 07/27/15 08/10/15 10/20/15 10/20/15 COLLECTION DATE 07/27/15 07/27/15 08/10/15 10/20/15 10/20/15 , ____ J.Y.£!: ____ _ Greens Blueberries Tomatoes Eggplant Apples , ____ J.Y.£!: ____ _ Greens Blueberries Tomatoes Eggplant Apples _____ J.Y.£!: ____ _ Greens Blueberries Tomatoes Eggplant Apples Be-7 (+/-) 0.025 0.097 0.046 0.092 0.009 0.072 0.024* 0.063 -0.005 0.062 Zn-65 (+/-) -0.029 0.029 -0.013 0.022 -0.021 0.022 0.002 O.D18 -0.004 0.016 Cs-134 (+/-) -0.002 0.013 -0.019 0.011 -0.009 0.009 -0.014 0.008 -0.017 0.008 Annual Radiological Environmental Operating Report 2015 TABLE 8 FRUITS & VEGETABLES (pCi/g wet wt.) LOCATION 25 (fruit are extra samples not required by the REMODCM) K-40 (+/-) 1.954 0.355 0.809 0.251 2.069. 0.280 2.048*

0.256 1.265 0.226 Nb-95

(+/-) 0.004 0.012 -0.007 0.011 0.008 0.010 0.006 0.008 0.003 0.007 Cs-137 (+/-) -0.004 0.011 -0.003 0.009 0.003 0.008 0.002 0.007 0.003 0.008 Cr-51 (+/-) 0.021 0.109 0.040 0.107 -0.037 0.082 0.034 0.069 0.035 0.069 Zr-95

(+i:;---

-0.006 0.019 -0.001 0.019 0.003 0.016 0.006 0.013 0.008 0.012 Ba-140 ( +/-) -0.014 0.075 -0.035 0.066 0.002 0.047 0.003 0.035 0.030 0.032 3-18 Mn-54 Co-58 (+I-) ( +/-) 0.009 0.011 -0.009 0.012 -0.003 0.009 -0.004 0.010 0.006 0.008 0.002 0.009 0.002 0.007 -0.003 0.009 0.004 0.007 -0.006 0.007 Ru-103 Ru-106 ( +/-)

----------r+i.r--

-0.007 0.013 0.086 0.090 -0.003 0.011 -0.047 0.084 -0.003 0.009 -0.053 0.080 -0.004 0.007 -0.036 0.075 -0.003 0.007 -0.007 0.059 La-140 Ce-141 ( +/-) (+I-) 0.031 0.025 0.017 0.020 -0.011 0.023 -0.023 0.018 -0.003 0.015 0.002 0.014 -0.011 0.009 -0.002 0.012 0.002 0.010 0.001 0.012 Fe-59 Co-60 (+/-) (+/-) -0.008 0.027 -0.007 0.010 0.010 0.022 0.003 0.009 0.018 0.020 -0.002 0.009 -0.014 0.019 -0.006 0.009 -0.005 0.014 0.006 0.008 Sb-125 1-131

Fi-r--*

(~i~---*

0.003 0.029 0.011 0.034 -0.024 0.027 0.009 0.034 0.013 0.023 0.011 0.018 -0.007 0.022 0.015 0.012 -0.007 0.01 ~ -0.001 0.012 Ce-144 Ac-228 (+/-) (+/-) -0.010 0.066 0.012 0.036 0.002 0.058 0.007 0.041 -0.043 0.058 0.009 0.034 0.002 0.049 -0.004 0.030 0.008 0.046 -0.007 0.027

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 TABLE 8 FRUITS & VEGETABLES (pCi/g wet wt.) LOCATION 26 (control, background location; fruit are extra samples not required by the REMODCM) COLLECTION DATE , ____ }_YE~----- Be-7 K-40 Cr-51 Mn-54 Co-58 (+/-) (+/-) (+/-) (+/-) (+/-) 07/27/15 Greens 0.009 0.100 2.168 0.314 -0.036 0.113 0.003 0.011 -0.006 0.011 07/27/15 Blueberries 0.043 0.056 0.803 0.174 0.021 0.078 0.001 0.006 0.006 0.006 10/20/15 Eggplant 0.020 0.071 3.199 0.370 CJ.001 0.073 0.006 0.008 0.001 0.008 10/20/15 Apples 0.051 0.088 0.820 0.243 -0.061 0.081 0.001 0.010 -0.003 0.009 COLLECTION DATE _____ ])~~~----- Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 (+/-) (+/-) (+/-) (+/-) (+/-) 07/27/15 Greens -0.007 0.025 -0.003 0.013 0.022 0.021 -0.004 0.014 -0.011 0.094 07/27/15 Blueberries -0.018 0.017 0.005. 0.007 0.010 0.014 -0.002 0.008 0.027 0.060 10/20/15 Eggplant -0.002 0.020 0.003* 0.008 0.000 0.015 0.002 0.008 -0.032 0.073 10/20/15 Apples -0.006 0.023 0.003 0.010 0.005 0.017 -0.006 0.011 0.014 0.088 COLLECTION DATE , ____ }YE~----- Cs-134 Cs-137 Ba-140 La-140 Ce-141 (+/-) (+/-) (+/-) (+/-) (+/-) 07/27/15 Greens -0.001 0.012 -0.002 0.011 -0.021 0.071 0.022 0.022 0.015 0.021 07/27/15 Blueberries -0.009 0.007 -0.002 0.006 0.013 0.049 -0.014 0.016 -0.005 0.011 10/20/15 Eggplant -0.005 0.008 -0.002 0.009 0.020 0.036 0.007 0.012 0.001 0.015 10/20/15 Apples -0.002 0.011 0.004 0.010 0.047 0.044 0.000 0.013 0.016 0.015 3-19 Fe-59 Co-60 (+/-) (+/-) -0.022 0.027 -0.002 0.009 -0.005 0.015 -0.001 0.007 0.000 0.016 -0.005 0.008 -0.003 0.021 0.002 0.007 Sb-125 1-131 (+/-) (+/-) 0.012 0.028 -0.003 0.034 -0.014 0.020 0.000 0.023 0.004 0.021 -0.007 O.o15 0.006 0.027 -0.012 0.018 Ce-144 Ac-228 (+/-) (+/-) -0.039 0.076 -0.001 0.037 -0.031 0.039 0.015 0.028 0.023 0.056 -0.005 0.032 0.067 0.062 0.027 0.042

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 Be-7

-------T+i-r--

0.808 0.207 0.959 0.311 Zn-65

----------r+i-i ___

-0.026 0.031 0.001 0.059 Cs-134

----------r+,:y---

0.002 0.011 0.014 0.026 Be-7

----------r+i-r--

o.485 o.183 0.634 0.449 Zn-65

----------r+i-r--

-0.045 0.027 0.011 0.047 Cs-134

----------r+i:r--

0.000 0.012 -0.001 0.022 Annual Radiological Environmental Operating Report 2015 K-40

Fi-r-*

4.064 0.410 4.127 0.698 Nb-95

z.i7-r--*

-0.003 0.013 0.019 0.025 Cs-137

Fi-r--*

0.010 0.013 0.010 0.024 K-40

Fi-r--*

3.584 0.374 7.607 1.042 Nb-95

Fi-r--*

-0.005 0.012 -0.007 0.020 Cs-137

Fi-r--*

0.008 0.012 0.004 0.019 TABLE 9 BROADLEAF VEGETATION (pCi/g wet wt.) LOCATION 1 Cr-51

Fi:,---*

-0.019 0.126 -0.153 0.211 Zr-95

(+i:,---*

-0.021 0.022 0.015 0.036 Ba-140

(+i:,---*

-0.031 0.077 0.056 0.115 Mn-54

(+i:;--*

-0.004 0.012 0.021 0.020 Ru-103

**1+i=r-*

0.000 0.014 -0.008 0.023 La-140

(+i=r-*

0.003 0.019 -0.019 0.028 LOCATION 10 Cr-51

(+i=i---*

-0.009 0.115 -0.165 0.194 Zr-95

Fi:,---*

-0.005 0.020 -0.011 0.039 Ba-140

Fi:,---*

0.043 0.077 -0.046 0.080 Mn-54

(+i:;--*

0.015 0.011 0.002 0.018 Ru-103

(+i=r--

0.001 0.013 0.007 0.020 La-140

(+i=r--

0.007 0.016 -0.002 0.021 3-20 Co-58

----------Fi:r--

-0.003 0.011 -0.005 0.024 Ru-106

cn:r--

0.004 0.108 -0.005 0.217 Ce-141

----------c+t:r--

0.025 0.022 -0.018 0.039 Co-58

----------r+i:r--

-0.008 0.011 -0.011 0.017 Ru-106

----------cn:r--

-0.016 0.101 0.005 0.181 Ce-141

----------cn:r--

-0.015 0.022 0.022 0.038 Fe-59 Co*60

----------r+i-i __ _ *----------z.i7-r-0.019 0.026 o.01 o 0.012

-0.004 0.047 0.000 0.022 Sb-125 1-131

----------r+,:r--
----------z.i7-r--*

0.006 0.033 0.027 0.032 0.063 0.069 -0.031 0.039 Ce-144 Ac-228

----------r+,:r--
----------r+i-r--

-0.055 0.072 0.057 0.050 -0.018 0.174 0.145 0.134 Fe-59 Co-60

----------Fi-r--
----------Fi-) __ _

-0.006 0.024 -0.004 0.009 0.011 0.045 0.001 0.016 Sb-125 1-131

----------r+,:r--
----------r+i-r--

0.006 0.031 0.016 0.032 -0.044 0.057 -0.003 0.035 Ce-144 Ac-228

----------r+i-r--
----------F-r--

0.028 0.082 0.107 0.051 -0.010 0.146 -0.020 0.080

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 COLLECTION DATE 07/16/15 10/06/15 Be-7

--------Fr.r*-

0.604 0.258 0.826 0.288 Zn-65

----------r+r.r*-

-0.048 0.031 0.022 0.040 Cs-134

----------r+r.r*-

-0.008 0.016 -0.007 0.022 Be-7

----------r+r.r*-

1.021 0.193 1.042 0.290 Zn-65

----------wr--

-0.025 0.026 -0.040 0.038 Cs-134

----------r+r.r*-

-0.010 0.011 -0.032 0.022 Annual Radiological Environmental Operating Report 2015 K-40

Fi-r--*

2.840 0.398 3.430 0.699 Nb-95

z.i7-r--*

0.006 0.013 0.000 0.021 Cs-137

Fi-r--*

0.013 0.013 0.003 0.020 K-40

(-i7-r--*

3.805 0.372 3.261 0.598 Nb-95

Fi-r--*

-0.007 0.010 0.006 0.019 Cs-137

Fi-r--*

0.009 0.010 0.021 0.020 TABLE 9 BROADLEAF VEGETATION (pCi/g wet wt.) LOCATION 17 Cr-51 Mn-54

Fi:,---* ----------Ti*rr**

-0.055 0.140 -0.002 0.013 -0.068 0.196 -0.011 0.017 Zr-95 Ru-103

(+iT-* ----------,+ri*--

-0.002 0.023 -0.007 0.013 0.000 0.033 0.010 0.020 Ba-140 La-140

(+i:,---*

(+7y---

-0:042 0.083 -0.008 0.023 -0.052 0.096 0.009 0.033 LOCATION 26 (control, background location) Cr-51

(+i:,---*

-0.004 0.100 0.061 0.177 Zr-95

FiT-*

-0.003 0.017 0.002 0.035 Ba-140

Fi:,---*

0.020 0.061 -0.019 0.085 Mn-54

(+i=r--*

-0.009 0.010 -0.001 0.018 Ru-103

,+i=r*--

0.008 0.011 0.000 0.019 La-140

(+i=-r-*

0.005 0.017 -0.007 0.026 3-21 Co-58

----------(+t:r--

-0.009 0.014 -0.005 0.015 Ru-106

----------(+t:r--

-0.027 0.111 0.026 0.143 Ce-141

----------(+t:r--

0.010 0.023 -0.013 0.033 Co-58

---------T+i=;---

0.007 0.010 -0.008 0.016 Ru-106

----------(+t=r--

-0.033 0.087 -0.053 0.157 Ce-141

----------Ft:r--

-0.016 0.019 0.008 0.032 Fe-59

----------,+,:r--

0.000 0.029 0.034 0.048 Sb-125

----------[+1:r*-

0.008 0.037 -0.059 0.052 Ce-144

----------r+q*--

-0.047 0.086 -0.074 0.130 Fe-59

----------r;r.r--

0.011 0.023 -0.020 0.040 Sb-125

----------r+1:r*-

0.013 0.027 0.023 0.046 Ce-144

----------r+rr*--

0.015 0.063 0.009 0.127 Co-60

----------z.;r.r*-*

0.009 0.012 -0.006 0.024 1-131

----------(+i-r--

-0.017 0.038 0.008 0.034 Ac-228

----------r+r.r*-

0.026 0.049 0.063 0.076 Co-60

----------r+r.r--

0.004 0.011 0.010 0.019 1-131

----------z.;r.r*-

0.001 0.028 -0.025 0.033 Ac-228

----------r+r.r*-

0.022 0.040 0.007 0.093

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION

- .. !?~!~----*

01/26/15 02/24/15 03/31/15 04/28115 05/26/15 06130/15 07128115 08/25115 09/29/15 10/27115 11/24115 12/29/15 COLLECTION .**. !?~!~----* 01126/15 02/24115 03131115 04/28115 05126/15 06130/15 07/28/15 08125115 09/29115 10127/15 11124/15 12129/15 COLLECTION DATE 01/26115 02124115 03/31/15 04/28115 05126115 06130/15 07/28115 08125/15 09129115 10127/15 11124/15 12129/15 H-3

**r+r.r**--

375 135 92 117 319 134 176 121 645 154 622 156 437 188 546 136 433 243 1190 323 205 123 157 125 Co-60

**r+r.r**--

-1.4 3.2 1.4 4.2 -0.5 1.6 -1.1 3.7 0.6 3.9 1.7 3.2 -2.3 3.3 -0.1 4.2 0.1 4.1 4.0 4.9 3.5 3.3 3.2 3.9 1-131

**r+r.r**--

-2.8 4.6 5.8 6.6 4.7 8.3 4.5 6.9 -0.6 8.3 2.5 7.1 0.2 5.7 -1.3 6.1 0.9 7.9 -2.7 7.2 -0.9 5.4 -0.1 7.9 Be-7

-----------(+ri*---

-7.2 22.1 8.5 32.3 5.0 15.1 0.5 29.3 23.8 36.8 17.3 29.8 -0.9 26.8 -7.1 32.2 0.6 39:6 -28.5 42.0 -1.1 26.1 11.4 39.8 Zn-65

-----------Fi ___ _

-5.8 5.6 -3.7 10.4 -5.1 3.5 2.6 7.0 0.9 8.2 0.1 7.7 8.0 8.3 -11.3 9.8 -9.4 10.9 -10.5 12.5 4.6 8.4 -0.8 9.9 Cs-134

-----------(+i~i""""

-1.1 2.6 -4.8 3.7 -0.1 1.7 0.0 3.4 -5.4 4.4 1.4 3.5 3.7 3.4 -1.3 4.3 -4.4 5.2 0.3 4.7 -2.0 3.7 -4.6 4.6 Annual Radiological Environmental Operating Report 2015 K-40

**r+,:;-**-*

245 67 329 92 277 46 448 225 181 123 273 79 311 77 273 93 308 110 238 115 371 102 411 110 Nb-95

**r.;,:j*---*

0.9 2.5 -0.1 4.6 -0.3 1.7 TABLE 10 SEAWATER (pCi/I) LOCATION 32 Cr-51

-----------(+i~-----

-18.0 23.7 -5.1 31.9 8.0 21.1 28.1 32.5 -18.6 42.6 4.4 31.0 18.2 27.9 5.7 33.6 -7.6 41.4 -10.6 46.5 -30.1 31.0 -1.1 45.5 Zr-95

-----------(+i~-----

5.7 3.7 Note 2.4 4.7 -2.6 7.3 3.0 3.4 -4.5 6.2 -1.0 4.7 0.5 3.4 17.2 4.2 Note -0.6 3.8 1.9 3.5 -3.8 4.8 -1.3 3.4 3.1 4.5 -4.6 7.2 -0.8 6.0 1.5 5.2 3.8 7.6 0.3 7.5 -2.1 8.1 -2.1 5.1 1.6 8.3 Mn-54

**r+,:;*---*

0.4 2.3 -0.9 4.4 0.1 1.7 0.2 3.3 1.5 4.4 -0.5 3.2 -1.5 3.0 -0.1 3.2 1.5 4.8 -0.2 4.8 1.7 2.8 -5.2 4.1 Ru-103

**r+,:;**--*

-1.0 2.8 1.8 4.3 -0.9 2.4 1.9 3.6 -2.2 5.1 3.8 3.8 1.1 3.2 -0.3 3.7 -0.2 5.2 1.4 4.8 -0.9 3.8 -0.6 4.8 Co-58

(+i-i"""""

0.4 2.7 -3.1 3.9 -1.0 1.8 -1.4 3.5 -2.9 4.2 -0.5 3.2 -3.0 3.5 1.6 3.9 -2.5 5.1 1.2 4.9 -3.8 3.7 -1.2 4.4 Ru-106

(+i-i"""""

0.0 23.8 -12:7 38.6 -7.1 14.2 19.0 31.5 -2.9 38.3 10.7 28.4 -0.3 25.3 -7.6 33.9 -20.6 44.2 10.2 40.7 -0.2 35.9 9.6 43.4 Fe-59

----------*-c+i:;**--*

2.5 5.4 5.8 9.5 -0.8 4.0 0.6 6.8 -1.4 8.5 -3.6 6.3 -1.7 6.4 -0.9 9.2 -2.6 11.0 3.0 9.1 -4.9 6.8 -1.3 10.3 Sb-125

-----------*c+i:;**--*

-1.8 6.8 -3.3 9.6 0.3 4.7 4.0 9.3 -3.9 11.8 4.2 8.6 5.0 8.7 -1.6 11.4 -11.5 13.5 4.8 13.3 11.0 10.1 8.6 10.5 Note: Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. Cs-137

**r+,:i*---*

-0.9 2.8 -0.6 3.8 0.1 1.6

o.7 3.9 0.9 4.7 0.5 3.5 0.1 3.6 3.0 3.8 0.7 4.6

-0.1 4.7 -3.0 3.6 -2.8 5.0 Ba-140

-----------(+i~-----

-7.1 12.0 3.0 20.1 -8.5 14.3 13.2 19.9 3.6 23.0 -20.1 19.5 -0.9 16.0 2.5 14.7 3.0 22.1 -4.3 19.5 5.7 16.6 20.6 22.6 3-22 La-140

**c-:;,:;*---*

3.1 3.9 2.3 7.6 -1.9 4.3 -2.3 4.8 2.0 5.2 1.6 5.9 4.8 5.2 0.1 5.1 2.5 6.4 3.2 7.4 2.0 5.7 1.6 7.3 Ac-228

Fi-i" ___ _

-4.3 9.7 -5.0 15.9 -2.8 6.5 -79.5 30.5 2.9 15.7 4.0 12.2 1.6 12.4 -13.5 14.4 0.1 14.9 10.3 17.4 10.7 12.3 -2.2 16.3

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION DATE 03/16/15 06/09/15 09/15/15 12/08/15 COLLECTION DATE 03/16/15 06/09/15 09/15/15 12/08/15 COLLECTION DATE 03/16/15 06/09/15 09/15/15 12/08/15 H-3 (+/-) -62 107 45 118 54 159 91 118 Co-60

------------r;i-r---*

1.3 3.6 2.7 3.1 1.1 4.9 3.9 4.2 1-131

(+i-) _____

7.3 7.8 -3.3 7.2 -5.6 8.6 0.1 8.4 Be-7

-----------(+i:y----

4.7 30.1 1.8 27.5 -2.6 40.5 11.3 46.2 Zn-65

-----------(+i:,-----

-8.5 7.6 0.1 6.8 -12.6 10.3 1.7 11.2 Cs-134

-----------(+iT ____

-1.0 3.3 -2.6 2.9 -7.5 5.8 -0.7 5.4 Annual Radiological Environmental Operating Report 2015 TABLE 10 SEAWATER (pCi/I) LOCATION 37 (control, background location) K-40 Cr-51

[+1:)----*

-----------(+i:,-----

203 98 30.95 35.23 314 80 -3.13 31.22 242 120 27.20 46.87 370 118 38.93 47.98 Nb-95 Zr-95

(+,:) _____

-----------(+i:,-----

-1.4 3.8 2.9 6.7 -0.6 3.2 -3.5 5.6 1.3 5.0 1.0 8.5 2.6 4.5 -2.8 7.7 Cs-137 Ba-140

[+1:i----*

-----------(+i:,-----

2.4 3.6 -2.2 17.9 -1.1 3.0 3.5 18.3 -0.9 5.3 -28.8 20.9 0.7 5.5 8.4 22.0 3-23 Mn-54 (+/-) 0.5 3.5 -0.8 2.9 0.0 4.5 1.1 5.6 Ru-103 (+/-) -4.3 4.5 -2.4 3.6 -1.8 5.1 -0.1 5.0 La-140

r+1T ____

1.6 6.8 1.3 5.0 -4.4 6.6 -5.4 10.2 Co-58 Fe-59

-----------(:;:i_r----
-----------T+i:;----*

-2.6 3.3 2.3 8.4 1.1 3.0 0.2 6.1 0.9 4.7 6.0 8.2 -2.5 5.2 -5.9 9.4 Ru-106 Sb-125

-----------(:;:i_r----
-----------T+i:;----*

17.2 32.5 -5.9 10.2 -20.0 27.0 -1.3 7.6 -6.3 39.6 -7.3 13.4 -25.1 42.1 -6.5 12.7 Ac-228

-----------(:;:i-i _____

5.8 14.4 -4.1 11.2 -20.2 19.5 -12.1 19.4

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 11 BOTIOM SEDIMENT (pCi/g dry wt.) COLLECTION .k9..gAILQt!. ____ !?A!S..... Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

T+r.r--*

'[+1:;---*

.. (+1:)*--*

(+1:)"'"

(+i-)""

T+1:r--*

31 01/16/15 0.095 0.235 14.16 0.98 0.087 0.283 0.011 0.027. 0.010 0.025 0.001 0.048 31 11/20/15 -0.231 0.308 14.17 1.34 -0.102 0.329 0.007 0.038 -0.013 0.034 -0.113 0.073 32 06/24/15 0.090 0.327 15.79 1.42 -0.177 0.360 0.025 0.040 0.030 0.039 -0.117 0.093 32 12/10/15 -0.131 0.340 13.06 1.84 0.113 0.369 0.003 0.033 0.007 0.029 -0.027 0.053 33 05/13/15 0.248 0.364 16.55 1.34 0.115 0.456 0.011 0.042 -0.013 0.043 0.075 0.083 33 07/23/15 0.320 0.324 16.14 1.15 -0.031 0.394 0.010 0.030 0.012 0.035 0.037 0.084 34 03/12/15 -0.115 0.144 14.22 0.71 0.019 0.146 -0.002 0.016 0.000 0.016 -0.029 0.041 34 07/23/15 -0.105 0.214 19.94 1.24 -0.179 0.246 -0.010 0.024 0.011 0.026 -0.019 0.069 37 01/16/15 0.009 0.141 12.45 0.92 -0.213 0.165 -0.004 0.016 -0.001 O.Q18 0.002 0.049 37 11/20/15 0.021 0.217 18.05 1.25 -0.054 0.216 0.018 0.025 -0.008 0.025 0.016 0.067 (37 is control, background location) COLLECTION .k9..gAILQt-J..

- .* !?A!L..

Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

<'+,:r*..

(-.;:,:;-*--

{+,:;----

(+,:)" -----------F,:r*..

*T+i:i*--*

31 01/16/15 -0.001 0.022 -0.067 0.053 0.011 0.028 0.007 0.052 -0.004 0.030 0.210 0.236 31 11/20/15 0.028 0.036 0.026 0.084 -0.032 0.042 0.034 0.076 0.034 0.041 -0.037 0.336 32 06/24/15 0.001 0.034 -0.062 0.117 0.068 0.046 -0.028 0.074 0.015 0.043 0.077 0.306 32 12/10/15 -0.007 0.034 -0.004 0.070 -0.013 0.034 0.019 0.068 0.015 0.036 0.010 0.256 33 05/13/15 -0.007 0.038 -0.130 0.108 0.035 0.043 0.043 0.075 -0.021 0.046 -0.346 0.369 33 07/23/15 0.022 0.031 -0.085 0.080 -0.009 0.041 0.010 0.065 o.o:i2 0.041 0.022 0.278 34 03/12/15 -0.001 0.016 -0.049 0.046 O.o18 0.017 0.008 0.029 0.006 O.Q18 -0.026 0.143 34 07/23/15 -0.014 0.025 -0.062 0.075 -0.011 0.026 -0.028 0.045 0.017 0.025 0.121 0.205 37 01/16/15 0.004 0.019 -0.010 0.052 -0.006 0.020 0.004 0.036 0.002 0.020 -0.073 0.152 37 11/20/15 -0.002 0.029 -0.036 0.071 0.013 0.029 0.007 0.049 -0.019 0.027 -0.209 0.231 COLLECTION .k9..gAILQt!. DATE

~..'!:J.1..'!.~L...

Sb-125 1-131 Cs-134 Cs-137 Ac-228 (+/-)

(+,:;---*

(+,:;--..

c+,:r*..

'(+1:)" -----------F,:r*--

31 01/16/15 0.000 0.026 -0.020 0.071 -0.016 0.077 0.028 0.027 0.017 0.027 0.311 0.392 31 11/20/15 0.009 0.038 -0.024 0.092 0.062 0.096 -0.003 0.040 -0.026 0.042 2.164 0.381 Note 32 06/24/15 -0.054 0.036 -0.004 0.090 0.057 0.104 0.002 0.039 0.010 0.041 1.211 0.300 Note 32 12/10/15 0.016 0.025 -0.016 0.086 0.009 0.100 -0.018 0.031 0.025 0.040 1.010 0.379 Note 33 05/13/15 -0.045 0.039 -0.003 0.112 -0.042 0.118 0.011 0.042 -0.018 0.044 0.130 0.366 33 07/23/15 0.002 0.030 0.022 0.087 -0.013 0.165 0.045 0.035 -0.042 0.033 0.605 0.215 Note 'Note: Extra counts detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. 34 03/12/15 0.000 0.016 -0.003 0.041 -0.009 0.047 -0.008 0.017 0.002 O.Q18 0.181 0.126 34 07/23/15 -0.005 0.022 -0.024 0.051 -0.057 0.101 -0.008 0.022 -0.020 0.025 0.012 0.162 37 01/16/15 -0.019 O.D15 -0.041 0.038 0.038 0.042 -0.003 0.019 0.016 0.017 0.027 0.127 37 11/20/15 0.000 0.021 0.007 0.064 -0.036 0.055 O.D15 0.023 0.006 0.022 0.146 0.134 3-24

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 COLLECTION LOCATION DATE 29 01/15/15 29 29 29 32 32 32 32 35 35 35 35 36 36 36 36 90 90 90 90 05/12/15 07/22/15 10/05/15 01/15/15 05/12/15 07/22/15 11/20/15 01/15/15 05/12/15 07/22/15 10/05/15 01/16/15 06/12/15 09/10/15 11/20/15 03/12/15 05/13/15 07/23/15 12/04/15 TABLE 12 AQUATIC FLORA-FUCUS (pCi/g wet wt.) (all samples are extra, not required by the REMODCM) Be-7 (+/-) 0.2670 0.1124 K-40 (+/-) 6.0720 0.4164 0.1966 0.0612 6.0290 0.2142 0.0643 0.0905 6.8460 0.4335 0.0667 0.0875 6.0680 0.6264 0.1980 0.1* 178 8.3540 0.3809 0.0234 0.0858 7.1700 0.4172 0.0881 0.0621 6.3020 0.3398 0.0319 0.1159 9.4520 0.6652 0.2375 0.1582 7.7990 0.5258 0.1387 0.0832 Note 1 6.5640 0.3650 0.0942 0.0954 6.8390 0.3896 0.0709 0.1506 7.8080 0.8566 Cr-51 (+/-) -0.0073 0.0936 0.0115 0.0494 -0.0694 0.1072 0.0064 0.1127 -0.0712 0.0793 -0.0224 0.0892 -0.0053 0.0705 0.0407 0.1118 -0.0154 0.0387 -0.0562 0.0915 -0.0368 0.0912 0.0654 0.1500 Note 1: Result is less than minimum detectable activity (MDA) of 0.149 pCi/g. 0.1634 0.1287 6.1650 0.5130 0.0931 0.1153 0.0651 0.0896 6.0150 0.4647 -0.0282 0.0964 0.0623 0.0851 7.1020 0.4150 0.0014 0.0939 0.1802 0.1193 Note 2 7.1070 0.6037 -0.0017 0.1067 Note 2: Result is less than minimum detectable activity (MDA) of 0.224 pCi/g. 0.2663 0.1021 6.1880 0.2976 -0.0020 0.0665 0.1291 0.0993 -0.0139 0.0526 0.0713 0.1144 6.6930 0.3477 7.0070 0.3016 8.6210 0.5996 0.0049 0.0830 -0.0286 0.0583 0.0834 0.1103 3-25 Mn-54 (+/-) -0.0048 0.0098 -0.0003 0.0044 -0.0046 0.0093 0.0010 0.0122 0.0010 0.0078 -0.0039 0.0093 -0.0033 0.0069 0.0052 0.0124 0.0005 0.0038 0.0002 0.0087 0.0087 0.0091 0.0062 0.0147 -0.0057 0.0129 0.0033 0.0100 0.0014 0.0086 0.0020 0.0131 0.0021 0.0058 0.0079 0.0081 -0.0006 0.0060 -0.0009 0.0115 Co-58 (+/-) -0.0088 0.0103 0.0006 0.0047 0.0003 0.0102 0.0014 0.0123 -0.0029 0.0079 0.0056 0.0095 0.0023 0.0075 0.0024 0.0124 -0.0002 0.0036 -0.0082 0.0089 -0.0040 0.0101 -0.0089 0.0178 0.0069 0.0136 -0.0042 0.0108 -0.0011 0.0089 -0.0002 0.0135 -0.0035 0.0061 0.0016 0.0092 0.0032 0.0065 0.0149 0.0126 Fe-59 (+/-) 0.0042 0.0250 -0.0024 0.0115 0.0038 0.0258 0.0000 0.0351 -0.0020 0.0202 0.0084 0.0215 0.0017 0.0183 -0.0053 0.0332 -0.0025 0.0112 0.0033 0.0215 0.0129 0.0228 -0.0002 0.0399 -0.0111 0.0338 -0.0257 0.0262 0.0126 0.0230 0.0086 0.0340 0.0174 0.0155 -0.0016 0.0199 -0.0029 0.0167 -0.0197 0.0288

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 12 AQUATIC FLORA-FUCUS (pCi/g wet wt.) (all samples are extra, not required by the REMODCM) COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 29 01/15/15 0.0064 0.0083 -0.0107 0.0251 0.0007 0.0102 -0.0161 0.0186 -0.0021 0.0104 -0.0836 0.0847 29 05/12/15 0.0017 0.0049 -0.0162 0.0120 0.0037 0.0050 0.0090 0.0089 0.0025 0.0051 -0.0059 0.0410 29 07/22/15 0.0085 0.0103 -0.0294 0.0259 0.0065 0.0105 0.0229 0.0195 0.0044 0.0107 -0.0424 0.0891 29 10/05/15 0.0051 0.0141 -0.0206 0.0348 -0.0027 0.0127 -0.0018 0.0231 0.0014 0.0133 -0.0307 0.1233 32 01/15/15 0.0010 0.0094 -0.0137 0.0183 0.0047 0.0084 0.0144 0.0144 -0.0090 0.0083 -0.0340 0.0702 32 05/12/15 -0.0014 0.0090 -0.0032 0.0234 -0.0002 0.0096 0.0030 0.0165 -0.0004 0.0096 0.0250 0.0756 32 07/22/15 0.0026 0.0076 -0.0145 0.0186 0.0035 0.0067 -0.0123 0.0112 -0.0019 0.0079 0.0387 0.0565 32 11/20/15 -0.0025 0.0143 -0.0249 0.0299 0.0132 0.0120 0.0153 0.0191 0.0007 0.0128 0.0693 0.1101 35 01/15/15 -0.0078 0.0054 0.0107 0.0100 0.0018 0.0046 0.0025 0.0092 0.0020 0.0044 0.0051 0.0326 35 05/12/15 0.0039 0.0082 -0.0114 0.0207 0.0034 0.0098 0.0011 0.0165 0.0030 0.0099 0.0029 0.0782 35 07/22/15 0.0071 0.0098 -0.0260 0.0206 0.0090 0.0098 0.0024 0.0166 0.0038 0.0096 0.0289 0.0764 35 10/05/15 0.0107 0.0191 -0.0275 0.0482 0.0084 0.0172 0.0190 0.0328 0.0079 0.0166 0.0488 0.1298 36 01/16/15 -0.0024 0.0118 -0.0463 0.0316 -0.0008 0.0136 0.0051 0.0238 -0.0013 0.0130 -0.0150 0.1086 36 06/12/15 0.0018 0.0104 -0.0285 0.0240 0.0051 0.0108 -0.0013 0.0193 0.0061 0.0112 0.0024 0.0824 36 09/10/15 -0.0014 0.0088 -0.0004 0.0272 0.0024 0.0106 -0.0175 0.0169 0.0028 0.0095 -0.0184 0.0732 36 11/20/15 0.0104 0.0140 -0.0316 0.0285 0.0037 0.0149 -0.0316 0.0266 -0.0056 0.0140 -0.0437 0.1158 90 03/12/15 0.0054 0.0057 -0.0215 0.0160 -0.0014 0.0068 -0.0011 0.0118 -0.0017 0.0067 0.0431 0.0564 90 05/13/15 -0.0030 0.0084 0.0066 0.0209 0.0004 0.0087 0.0131 0.0151 -0.0031 0.0085 0.0314 0.0708 90 07/23/15 0.0031 0.0061 -0.0264 0.0162 -0.0062 0.0066 -0.0023 0.0115 0.0027 0.0066 0.0494 0.0526 90 12/04/15 0.0079 0.0137 -0.0276 0.0289 -0.0044 0.0130 0.0104 0.0249 -0.0089 0.0131 -0.0258 0.0986 3-26

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Ag-110M (+/-) 29 01/15/15 -0.0030 0.0085 29 05/12/15 0.0013 0.0045 29 07/22/15 -0.0038 0.0095 29 10/05/15 0.0025 0.0135 32 01/15/15 0.0115 0.0080 32 05/12/15 -0.0034 0.0077 32 07/22/15 -0.0075 0.0063 32 11/20/15 0.0004 0.0113 35 01/15/15 -0.0028 0.0042 35 05/12/15 -0.0026 0.0090 35 07/22/15 -0.0015 0.0082 35 10/05/15 -0.0100 0.0160 36 01/16/15 0.0001 0.0109 36 06/12/15 -0.0006 0.0095 36 09/10/15 -0.0046 0.0082 36 11/20/15 -0.0007 0.0138 90 03/12/15 -0.0077 0.0057 90 05/13/15 -0.0017 0.0078 90 07/23/15 0.0024 0.0054 90 12/04/15 -0.0082 0.0107 Annual Radiological Environmental Operating Report 2015 TABLE 12 AQUATIC FLORA-FUCUS (pCi/g wet wt.) (all samples are extra, not required by the REMODCM) Sb-125 1-131 Cs-134 (+/-) (+/-) (+/-) 0.0015 0.0215 0.0237 0.0283 -0.0036 0.0099 0.0004 0.0120 0.0047 0.0134 -0.0113 0.0047 0.0342 0.0236 0.0032 0.0332 -0.0193 0.0105 -0.0030 0.0322 -0.0214 0.0229 0.0016 0.0160 -0.0054 0.0215 0.0257 0.0228 -0.0092 0.0075 0.0010 0.0233 0.0070 0.0279 -0.0007 O.Q093 0.0017 0.0167 -0.0089 0.0218 -0.0065 0.0069 -0.0209 0.0344 0.0196 0.0343 -0.0100 0.0122 0.0051 0.0110 -0.0001 0.0119 -0.0003 0.0031 -0.0076 0.0232 0.0014 0.0271 0.0028 0.0089 0.0026 0.0233 -0.0034 0.0281 -0.0188 0.0088 0.0034 0.0432 -0.0096 0.0260 -0.0186 0.0194 -0.0028. 0.0301 0.0173 0.0308 -0.0058 0.0133 0.0044 0.0208 0.0189 0.0341 -0.0104 0.0107 -0.0023 0.0252 -0.0043 0.0205 0.0071 0.0084 -0.0041 0.0324 0.0273 0.0275 0.0017 0.0107 0.0071 0.0165 0.0109 0.0195 -0.0025 0.0063 -0.0193 0.0202 0.0044 0.0212 -0.0034 0.0090 0.0027 0.0148 0.0222 0.0186 0.0011 0.0063 -0.0158 0.0269 0.0055 0.0286 0.0049 0.0137 Cs-137 Ac-228 (+/-) (+/-) 0.0015 0.0093 0.0387 0.0683 0.0026 0.0048 0.0978 0.0242 0.0043 0.0099 0.1282 0.0574 -0.0126 0.0151 0.1416 0.0633 -0.0154 0.0085 0.0751 0.0549 0.0016 0.0084 0.0719 0.0391 Note 1 0.0025 0.0065 0.0326 0.0424 0.0004 0.0129 0.0797 0.0800 0.0003 0.0044 0.1261 0.0750 Note2 0.0035 0.0094 0.0078 0.0816 0.0094 0.0087 0.1151 0.0623 0.0052 0.0160 -0.0186 0.0695 -0.0054 0.0125 0.0802 0.0665 -0.0016 0.0100 0.0989 0.0483 0.0075 0.0092 0.0185 0.0383 -0.0030 0.0140 0.0898 0.0573 Note 1 0.0048 0.0060 0.0552 0.0379 0.0020 0.0083 0.0615 0.0472 0.0007 0.0059 0.0902 0.0479 0.0096 0.0118 0.0840 0.0768 Note 1: Result for Ac-228 was less than Minimum Detectable Activity (MDA) Note 2: Extra counts detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. 3-27

Dominion Nuclear Connecticut, Inc. Millstone Powet Station COLLECTION LOCATION DATE 29 07/28/15 29 32 32 35 35 35 10/06/15 03/23/15 04/07/15 05/20/15 07/14/15 10/06/15 COLLECTION Be-7

(+iT*-*

-0.057 0.106 -0.093 0.276 -0.064 0.075 -0.011 0.108 -0.155 0.171 0.000 0.027 0.022 0.281 LOCATION DATE Co-60 (+I-) 29 07/28/15 -0.005 0.012 29 32 32 35 35 _35 10/06/15 03/23/15 04/07/15 05/20/15 07/14/15 10/06/15 COLLECTION LOCATION DATE 29 07/28/15 29 10/06/15 32 03/23/15 32 04/07/15 35 05/20/15 35 07/14/15 35 10/06/15 0.000 0.025 0.004 0.009 0.000 0.012 -0.009 0.020 0.002 0.002 -0.013 0.030 Ag-110M

,+ir-*

-0.002 0.011 -0.021 0.032 0.005 0.008 -0.001 0.011 0.009 O.Q18 0.001 0.002 -0.039 0.030 Annual Radiological Environmental Operating Report 2015 K-40

r;,:r**

4.512 0.378 3.792 0.946 5.314 0.325 5.002 0.406 4.466 0.573 4.020 0.151 3.775 0.759 Zn-65 (+I-) -0.042 0.028 -0.018 0.069 -0.027 0.018 -0.057 0.028 0.020 0.044 0.001 0.006 -0.001 0.082 Sb-125

f0=i __ _

0.020

0.031 0.012 0.079 0.012 0.019

-0.012 0.033 -0.017 0.054 0.003 0.006 0.053 0.100 TABLE 13 FISH (pCi/g wet wt) Cr-51

----------Fi-r***

-0.042 0.133 0.046 0.239 -0.108 0.095 -0.026 0.114 0.006 0.187 -0.014 0.039 -0.082 0.312 Nb-95 (+/-) 0.001 0.013 -0.001 0.033 0.002 0.009 0.017 0.012 0.010 0.020 0.002 0.003 0.043 0.033 1-131 (+/-) 0.010 0.045 0.021 0.045 0.013 0.052 0.007 0.025 0.004 0.039 -0.047 0.034 -0.009 0.053 3-28 Mn-54

c+t:i*--

0.003 0.011 0.002 0.029 0.002 0.008 -0.004 0.011 -0.002 0.021 0.000 0.002 -0.009 0.034 Zr-95

c+iT--

-0.015 0.022 -0.019 0.059 0.010 0.016 0.007 0.021 0.001 0.035 -0.001 0.005 -0.023 0.057 Cs-134

c+iT--

0.000 0.014 -0.004 0.036 -0.004 0.008 -0.043 0.012 0.007 0.024 -0.001 0.002 0.013 0.038 Co-58

----------Fi-r*-*

-0.010 0.012 0.000 0.032 0.001 0.009 -0.011 0.012 -0.014 0.021 -0.001 0.003 0.006 0.030 Ru-103 (+/-) -0.004 0.014 -0.012 0.032 -0.002 0.010 0.003 0.012 0.008 0.022 0.001 0.004 -0.030 0.035 Cs-137 (+/-) 0.007 0.012 0.001 0.033 0.000 0.008 0.002 0.012 -0.007 0.021 0.002 0.003 0.028 0.034 Fe-59

(+i'.:')""-

-0.020 0.028 0.021 0.070 0.005 0.021 -0.018 0.025 -0.011 0.042 0.001 0.007 -0.006 0.067 Ru-106 (+I-) -0.099 0.104 -0.. 154 0.256 -0.004 0.070 0.007 0.106 0.028 0.192 -0.017 0.022 0.186 0.289 Ac-228

(+i:-i---

-0. 050 0.047 -0.116 0.130 -0.033 0.047 0.008 0.061 0.035 0.080 -0.035 0.020 -0.014 0.115

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 14 OYSTERS (pCi/g wet wt.) COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59

('.;.i~)---

,'.H~)---

(+/-) (+/-) (+/-) (+/-) 31 03/12/15 -0.087 0.199 2.310 0.607 0.000 0.224 0.006 0.027 -0.006 0.021 0.011 0.049 31 05/21/15 -0.090 0.114 2.515 0.493 -0.045 0.122 -0.002 0.015 0.008 0.016 0.018 0.033 31 08/10/15 0.167 0.480 2.269 0.983 -0.126 0.478 -0.027 0.051 0.010 0.053 0.049 0.112 31 12/07/15 0.045 0.190 2.226 0.841 0.001 0.186 -0.001 0.039 0.006 0.027 -0.036 0.060 32 03/04/15 -0.062 0.244 2.149 0.620 0.150 0.291 -0.012 0.027 0.031 0.027 -0.054 0.066 32 05/19/15 -0.385 0.431 2.034 0.840 -0.294 0.451 0.031 0.041 -0.015 0.044 -0.020 0.079 32 07/10/15 -0.090 0.142 2.406 0.441 -0.088 0.148 -0.003 0.017 -0.008 0.019 -0.029 0.032 32 12/09/15 -0.030 0.219 2.112 0.839 0.198 0.318 -0.060 0.046 -0.010 0.037 0.027 0.081 88 03/05/15 0.069 0.261 1.539 0.793 0.021 0.343 -0.002 0.029 -0.019 0.028 0.003 0.066 88 05/20/15 -0.048 0.154 1.891 0.470 -0.057 0.174 0.003 0.019 0.002 0.018 0.027 0.038 88 08/19/15 0.081 0.396 2.784 1.209 -0.277 0.320 -0.006 0.039 0.005 0.047 0.046 0.099 88 12/07/15 0.138 0.357 1.822 1.105 0.236 0.346 0.049 0.048 -0.030 0.042 0.008 0.081 37 03/10/15 0.029 0.194 2.583 0.612 0.166 0.242 -0.012 0.022 0.020 0.027 -0.015 0.055 37 05/29/15 0.023 0.292 2.247 0.917 0.030 0.378 -0.019 0.036 -0.011 0.041 -0.016 0.079 37 08/31/15 0.162 0.302 2.195 1.031 -0.326 0.311 0.033 0.043 -0.016 0.032 -0.063 0.072 37 01/15/16 0.095 0.215 1.025 0.656 -0.020 0.222 0.025 0.026 -0.017 0.026 -0.020 0.053 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-29

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Co-60 (+/-) 31 03/12/15 0.018 0.025 31 05/21/15 0.017 0.018 31 08/10/15 -0.016 0.056 31 12/07/15 0.020 0.046 32 03/04/15 0.020 0.029 32 05/19/15 0.004 0.042 32 07/10/15 0.002 0.016 32 12/09/15 -0.006 0.029 88 03/05/15 0.003 0.028 88 05/20/15 0.000 0.017 88 08/19/15 0.019 0.047 88 12/07/15 -0.002 0.043 37 03/10/15 -0.008 0.020 37 05/29/15 0.009 0.038 37 08/31/15 0.026 0.036 37 01/15/16 -0.006 0.024 Annual Radiological Environmental Operating Report 2015 TABLE 14 OYSTERS (pCi/g wet wt.) Zn-65 Nb-95 Zr-95 (+/-) (+/-) (+/-) -0.033 0.054 0.008 0.028 0.001 0.046 -0.039 0.037 -0.010 0.016 -0.011 0.026 -0.125 0.112 -0.007 0.050 -0.028 0.096 -0.061 0.065 0.012 0.036 -0.017 0.055 -0.030 0.054 0.020 0.035 0.036 0.055 -0.048 0.099 -0.003 0.044 -0.030 0.074 -0.031 0.042 0.015 0.019 -0.017 0.033 -0.027 0.071 0.022 0.047 -0.030 0.063 -0.061 0.062 -0.024 0.030 0.000 0.054 -0.073 0.043 0.004 0.019 0.019 0.034 -0.043 0.106 -0.031 0.039 -0.054 0.092 -0.026 0.097 -0.012 0.053 -0.003 0.098 -0.060 0.061 -0.008 0.023 0.043 0.050 -0.103 0.082 0.023 0.034 0.013 0.065 -0.133 0.094 0.005 0.036 -0.032 0.066 -0.062 0.059 0.035 0.024 0.007 0.045 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-30 Ru-103 Ru-106

,+i~r---

(+/-) 0.012 0.027 0.073 0.201 0.000 0.015 0.008 0.124 0.007 0.065 0.075 0.484 -0.024 0.034 0.022 0.287 -0.009 0.035 0.024 0.248 -0.019 0.049 0.149 0.467 -0.004 0.020 -0.216 0.158 -0.016 0.039 0.051 0.347 0.025 0.037 -0.153 0.287 0.008 0.020 -0.082 0.173 0.030 0.045 -0.370 0.321 -0.028 0.047 -0.290 0.410 -0.023 0.027 0.166 0.186 0.004 0.041 -0.144 0.294 0.016 0.041 -0.172 0.337 0.004 0.027 0.195 0.231

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE Ag-110M

(+i:) ___

31 03/12/15 0.011 0.023 31 05/21/15 0.000 0.015 31 08/10/15 -0.001 0.048 31 12/07/15 0.014 0.031 32 03/04/15 -0.013 0.026 32 05/19/15 -0.005 0.048 32 07/10/15 0.017 0.017 32 12/09/15 -0.019 0.041 88 03/05/15 0.000 0.029 88 05/20/15 0.009 0.016 88 08/19/15 0.026 0.038 88 12/07/15 -0.016 0.042 37 03/10/15 -0.001 0.021 37 05/29/15 -0.023 0;029 37 08/31/15 0.012 0.037 37 01/15/16 -0.028 0.025 Annual Radiological Environmental Operating Report 2015 TABLE 14 OYSTERS (pCi/g wet wt.) Sb-125 1-131 Cs-134 (+/-) (+/-) (+/-) -0.016 0.053 0.023 0.080 -0.015 0.025 -0.009 0.038 -0.007 0.026 0.001 0.017 0.005 0.135 0.106 0.119 -0.002 0.069 0.000 0.079 -0.020 0.041 0.001 0.032 -0.028 0.073 -0.143 0.111 0.017 0.029 -0.071 0.121 -0.030 0.098 -0.073 0.050 0.011 0.044 0.004 0.042 0.014 0.019 -0.012 0.104 -0.002 0.068 0.027 0.042 0.048 0.077 0.063 0.120 0.004 0.032 0.039 0.050 0.000 0.034 0.005 0.021 0.025 0.134 0.021 0.070 -0.029 0.052 0.080 0.124 -0.096 0.085 -0.058 0.049 Cs-137 Ac-228

(+i:) ___

(+/-) 0.010 0.028 0.010 0.090 -0.002 0.017 0.023 0.067 0.038 0.055 0.149 0.178 -0.030 0.033 -0.185 0.162 0.011 0.027 0.101 0.103 -0.014 0.051 -0.067 0.187 -0.009 0.018 0.016 0.071 0.013 0.043 -0.043 0.148 -0.017 0.033 0.055 0.134 -0.005 0.019 0.097 0.091 -0.005 0.046 0.254 0.169 Note 0.005 0.045 0.036 0.153 Note: Ac-228 was not identified in sample. Counts in Ac-228 peak area were from naturally occuring Pb-214. 0.021 0.063 0.002 0.066 -0.031 0.026 . -0.014 0.024 -0.041 0.094 0.003 0.088 -0.054 0.103 -0.003 0.036 0.000 0.032 -0.092 0.139 0.040 0.101 0.027 0.074 -0.002 0.041 -0.008 0.040 0.031 0.139 0.055 0.064 0.007 0.053 0.008 0.028 0.015 0.025 -0.026 0.108 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-31

Dominion Nuclear Connecticut, Inc. Millstone Power Station COLLECTION LOCATION DATE 29 03/12/15 29 06/09/15 29 07/24/15 29 10/07/15 38 38 38 06/11/15 08/04/15 10/27/15 COLLECTION LOCATION DATE 29 03/12/15 29 06/09/15 29 07/24/15 29 10/07/15 38 38 38 06/11/15 08/04/15 10/27/15 COLLECTION LOCATION DATE 29 03/12/15 29 06/09/15 29 07/24/15 29 10/07/15 38 38 38 06/11/15 08/04/15 10/27/15 Be-7 (+/-) 0.077 0.350 0.032 0.204 0.265 0.348 0.314 0.243 0.126 0.055 0.096 0.268 0.358 0.406 Co-60

-----------f+1:r*--

-o.01 o 0.036 0.009 0.027 0.005 0.031 -0.010 0.027 -0.002 0.011 0.009 0.027 0.043 0.055 ______ e-JJ:].~~1~1_ ____ _ (+/-) 0.003 0.037 0.027 0.023 0.010 0.034 -0.008 0.027 -0.001 -0.009 -0.010 0.028 0.043 0.054 Annual Radiological Environmental Operating Report 2015 K-40

-----------,+i-r*--

1.769 0.717 2.379 0.726 2.275 0.772 2.775 0.819 TABLE 15 CLAMS (pCi/g wet wt.) Cr-51 (+/-) -0.455 0.425 -0.033 0.229 0.021 0.380 0.173 0.245 2.144 2.205 1.992 0.604 0.058 0.297 0.431 0.544 0.951 -0.343 1.251 Note -0.088 Mn-54

(+i~----*

0.015 0.041 0.000 0.021 0.003 O.Q35 0.012 0.024 0.005 -0.002 -0.009 0.028 0.037 0.056 Note: Results is less than minimum detectable activity (MDA) of 2.67 pCi/g. Zn-65

-----------Fi-r*--

-o.034 0.066 0.000 0.056 -0.022 0.091 0.021 0.061 -0.052 0.072 -0.048 0.059 0.099 0.151 Sb-125 ( +/-) 0.063 0.100 -0.013 0.063 -0.050 0.084 -0.016 0.087 0.024 -O.Q38 -0.051 0.073 0.107 0.171 Nb-95

(:;:.i_y---*

0.041 0.039 0.021 0.025 0.028 0.042 O.Q15 0.031 0.001 -0.028 -0.013 0.029 0.044 0.053 1-131 (+/-) -0.048 0.121 -0.023 0.042 0.037 0.143 -0.083 0.050 0.144 0.042 0.015 3-32 0.120 0.152 0.100 Zr-95

(+i~----*

-0.001 0.063 -0.009 0.046 -0.049 0.066 0.016 0.052 0.007 -0.016 0.085 0.050 0.067 0.096 Cs-134 (+/-) -0.044 0.040 0.007 0.032 0.007 0.037 0.006 0.031 -0.023 -0.035 -0.043 0.030 0.043 0.065 Co-58

(+i~)----

0.025 0.035 -0.019 0.026 -0.023 0.034 -0.005 0.026 -0.001 0.015 0.001 Ru-103 0.033 0.051 0.059

(+i~f----

0.001 0.045 -0.017 0.025 0.004 0.045 -0.009 0.029 0.031 0.008 -0.010 0.033 0.051 0.055 Cs-137 ( +/-) -0.028 0.042 -0.010 0.026 0.036 0.036 -0.016 0.032 0.029 0.007 -0.001 0.028 0.039 0.056 Fe-59 (+/-) 0.016 0.065 0.005 0.054 0.012 0.070 -0.008 0.042 0.007 -0.045 -0.087 Ru-106 0.062 0.090 0.085

----------7+,:) ___ _

0.025 0.351 0.064 0.189 -0.070 0.344 -0.126 0.222 -0.085 -0.123 0.091 Ac-228 0.261 0.415 0.460 (+/-) 0.128 0.141 0.028 0.111 0.084 0.155 -0.046 0.117 0.079

0.018 0.144 0.109 0.159 0.220

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 COLLECTION LOCATION DATE 35 03/24/15 35 35 35 89 89 89 89 05/26/15 07/30/15 10/22/15 03/20/15 06/19/15 08/18/15 12/08/15 Be-7 (+/-) 0.228 0.320 -0.150 0.203 -0.046 -0.023 -0.341 -0.167 0.064 0.201 0.412 0.384 0.528 0.321 0.258 0.486 K-40 (+/-) 2.355 0.738 3.004 0.691 3.122 1.043 3.083 1.586 2.549 0.968 2.687 0.964 2.544 0.731 3.880 1.618 (89 is control, background location) COLLECTION LOCATION DATE 35 03/24/15 35 35 35 89 89 89 89 05/26/15 07/30/15 10/22/15 03/20/15 06/19/15 08/18/15 12/08/15 COLLECTION LOCATION DATE 35 03/24/15 35 35 35 89 89 89 89 05/26/15 07/30/15 10/22/15 03/20/15 06/19/15 08/18/15 12/08/15 Co-60 Zn-65

,+,:5*--* ------------r+i-r--*

0.008 0.032 -0.032 0.070 0.012 0.002 0.010 0.023 -0.010 -0.010 0.028 0.025 0.039 0.056 0.049 0.033 0.028 0.040 -0.050 -0.083 -0.067 -0.038 0.002 -0.056 -0.090 0.058 0.098 0.131 0.100 0.084 0.073 0.152 Ag-110M Sb-125

(+i-r--* ------------Fi-i*--*

-0.008 0.028 -0.010 0.075 0.009 0.029 -0.035 -0.021 0.000 -0.003 0.016 0.020 0.041 0.044 0.042 0.033 0.027 0.060 -0.014 0.044 0.001 -0.096 0.001 0.013 0.109 0.061 0.150 0.131 0.121 0.085 0.074 0.166 TABLE 16 LOBSTERS (pCi/g wet wt.) Cr-51 Mn-54 Co-58 Fe-59

r+i-r--* ------------1+,:r*-* ------------i+i-r--* ------------,+,:r*-*

-0.151 0.387 -0.004 0.032 -0.011 0.033 -0.009 0.075 -0.087 -0.235 0.089 0.149 0.005 -0.007 0.258 0.196 0.527 0.401 0.725 0.282 0.260 0.491 Nb-95 (+/-) 0.008 0.037 0.002 0.010 0.026 -0.041 0.003 0.004 0.044 1-131 0.025 0.045 0.052 0.046 0.042 0.029 0.061 (+/-) 0.254 0.203 0.027 -0.016 -0.020 -0.238 -0.025 0.014 0.039 3-33 0.052 0.160 0.067 0.481 0.083 0.049 0.091 0.018 -0.013 -0.026 0.000 0.009 0.003 0.013 0.021 O.D38 0.044 0.038 0.033 0.030 0:073 Zr-95 (+/-) 0.024 0.068 -0.028 .-0.022 0.073 -0.012 -0.002 0.007 0.099 0.048 0.091 0.073 0.079 0.068 0.050 0.130 Cs-134

,+,:r--*

-0.058 0.036 -0.009 -0.068 0.018 -0.032 0.007 -0.003 -0.006 0.030 0.056 0.049 0.045 0.032 0.035 0.070 -0.015 -0.022 -0.057 0.008 -0.022 -0.004 -0.007 0.029 0.051 0.051 0.044 0.037 0.029 0.059 Ru-103 (+/-) -0.003 0.042 0.012 0.027 0.027 -0.051 -0.001 0.011 -0.034 0.023 0.056 0.049 0.065 0.036 0.027 0.060 Cs-137 (+/-) 0.010 0.028 0.009 -0.039 -0.014 0.030 0.027 0.000 0.009 0.024 0.042 0.049 0.043 0.039 0.029 0.064 -0.015 0.089 0.013 0.090 -0.038 -0.004 0.023 0.054 0.100 0.080 0.106 0.088 0.055 0.149 Ru-106

,+i-r--*

0.152 0.290 -0.035 -0.030 0.068 -0.058 0.088 -0.141 -0.339 0.215 0.380 0.415 0.433 0.316 0.255 0.571 Ac-228

,.tt:r*-*

-0.015 0.112 -0.003 -0.162 0.042 -0.005 0.037 -0.159 0.019 0.096 0.211 0.251 0.142 0.124 0.094 0.233

Dominion Nuclear Connecticut, Inc. Millstone Power Station

4.

DISCUSSION OF RESULTS Annual Radiological Environmental Operating Report 2015 This section summarizes the results ofthe analyses on the REMP samples. The only case where station related radioactivity was detected was tritium (H-3) in seawater collected at the quarry discharge point. This was within the station boundary. The naturally occurring nuclides of Be-7, K-40, and Ac-228 were detected in numerous samples. Be-7 is from cosmic radiation. It was observed in air and broadleaf vegetation and in some fruits,, vegetable and fucus samples. K-40 and Ac-228 are two common terrestrial isotopes. K-40 was observed in almost every type of sample. Ac-228 results were variable; it was observed in some sediment and fucus samples. Cs-1.37 and Sr-90 from atmospheric nuclear weapons testing in the 1960's have been observed in the past. During 2015, Cs-137 was detected in soil samples. Sr-90 was not detected in 2015. 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 CaF2(Mn) glass bulb dosimeters were used for these measurements. In 1990, these were replaced by Harshaw CaF2(Mn) chips. In 2000, the CaF2(Mn) TLDs, were replaced with the CaS04(Tm) Panasonic model UD-804 ASx TLDs. Readings are recorded as uR/hr. The unit uR stands for 'micro-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. For gamma exposure a micro-roentgen is equivalent to a micro-rem, a measure of dose to man. The dosimeters are strategically placed at a number of onsite locations, as well as at inner and outer offsite 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 (73-75) 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 2006, three in 2007, three in 2009, three in 2010 and seven in 2015. None were loaded in 2008 or from 2011 to 2014. The exposure rate measurements at two of 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 73, 7.4 uR/hour at Location 74 and 6.7 uR/hour at Location 75). At Location 73 the readings have been lower since the fourth quarter of 2012, averaging 7.6 uR/hour. 4-1

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Table 1 in Section 3.2 lists the exposure rate r:neasurements for all 44 monitored locations. These measurements demonstrate the general variations in background radiation between the various onsite and offsite locations and include gamma exposure from all sources of radioactivity. For example, the Weather Shack (Location 2), Millstone Unit 3 Discharge (Location 5), Environmental Laboratory (Location 8), Bay Point Beach (Location 9), 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 Norwich and Old Lyme (Locations 15C and 16C). Figure 4.1-1 shows a historical trend of TLD exposure rate measurements, comparing an annual average of all indicator TLDs, an annual average bf 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. The average indicator and control readings were both 7.6 uR/hour. This is equivalent to an annual dose of about 67 mrem. Given the error in measurement results this is in agreement with the estimated dose from Millstone of about 0.25 mrem for 2015. The averages of all indicator locations for the period when Millstone Unit 1 was still in operation (1996 to 1999) exhibit the effects of N-16 BWR turbine building skyshine to immediate areas onsite. Skyshine increased exposure rates as high as 6 uR/hr at onsite monitoring stations. The elevated exposure rates from skyshine decreased rapidly with distance to levels indistinguishable from normal background measurements at the nearest offsite monitoring stations. Also apparent in Figure 4.1-1 is a change of the type of TLD dosimeter in the year 2000. The difference in response between the two types. of TLD dosimeters is apparent, with the new type 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 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. Locations 1 and 3 are important because they are onsite and located between the plant and nearby populated areas. 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 that 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 2015 data for Location 3 shows an increase likely attributable to the being closer to granite at the new location. 4-2

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Figiue 4.1-1 uR/hr Aiun1al l~e,u1una Exiiostrre Rate-20Year Histo1y 10 8 6 CD Q) m (j) (j) m a a 0 N 0 0 N N a 0 N (T') 0 0 N -.:i-0 0 N LO D 0 N 4-3 r-... 0 0 N IAll Indicators 1All Controls I I ndicator Loe 1 cl ndicator Loe 3 CD 8 N Q) 0 0 N 0..- 0 N 0 N N..- 0 N (T) 0 N '<:t 0 N L[') 0 N

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 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 every two weeks 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. pCi/m' pCi/m3 Figure 4.2-1 Air Particulate Gross Beta Activity Monthly Averages - 2015 0.019 ~----------------------------- -+-Indicators -...control 0.007 +------.---~-----.---~-----.---~-----.---~-----.---~--.,.-----, Jan Feb Mar Apr May Jun Jul Aug Sep Figure 4.2-2 Air Particulate Gross Beta Activity Monthly Averages - 5 Year Trend Oct Nov Dec 0.021 +--------------ti'-------------------- -+-Indicators..... Control 0.009 +-------- ---i- --------------------'1---- 0.007 N N N N N N rn rn rn rn rn rn <t <t <t <t <t <t "' "' "' "' "' "' ~.... ~.... ~.... ~.... c > ~ a. > i:. .._ > ~ a. > i:. > ~ c_ > c > ~ a. > i:. > ~ a. > .!!? 0 .!!? 0 .!!? 0 .!!? 0 .!!? 0 Vl z Vl z Vl z Vl z Vl z 4-4

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 4.4 Airborne Iodine (Table 3) Charcoal cartridges are included at all of the air particulate monitoring stations for the collection of atmospheric iodine. These cartridges were analyzed for 1-131 every two weeks. No detectable levels of 1-131 were seen in the 2015 charcoal samples. 4.4 Air Particulate Gamma (Table 4) The air particulate samples that are utilized for the gross beta analyses are composited quarterly and analyzed for gamma emitting isotopes. The results, as shown in Table 4, 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 any station radioactivity. 4.5 Soil (Table 5) This media is collected annually from one control and two indicator locations. Millstone has collected and analyzed soil since 2001. Prior to 2001, soil had not been sampled for over fifteen years because station related detectable activity had not been detected. Since 2001 no station detectable activity has been seen in these samples. Naturally occurring K-40 is detected in soil. In the Location 3 sample extra counts were detected in the Ac-228 peak area but there was no peak for positive identification of Ac-228. Cs-137 from nuclear weapons testing was detected in all three 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. Figure 4.6-1 shows the trend of Cs-137 in soil samples. Except for Location 4, the trend appears to be declining with time. Baseline levels should be useful in the future, when site characterization and decommissioning of the station become the focus during preparations for license termination. E u a. Figure 4.6-1 Cs-137 in Soil 1.8..,--------------------------- Loe 3

Loe 4
*...
Loe 14 1.6 +-

111,__ 1.4 +---*_,,**----r~ ..*~ ... ~ 1.2 0.8 I 0.6 ~ --~ ~, \\ I

- .,Al'........ *~

...._. *~ - - -L I.

*~

'** -** '" \\..... o.2 r-----------------------1---....-.,:,--------, ~ I 0 4,....:..._ II 0 +-------,-------.------r----,..-----,------r------, 2001 2003 2005 2007 2009 2011 2013 2015 Year 4-5

Dominion Nuclear Connecticut, Inc. Millstone Power Station 4.6 Cow Milk (Table 6) Annual Radiological Environmental Operating Report 2015 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 Millstone to be considered an indicator location (i.e. within 10 miles) have ceased operation. One cow milk location, about ten and half miles from the station, was sampled as an extra, not required sample and results are shown in Table 6. Naturally occurring K-40 is the only positive result seen in cow milk. The Sr-89 sample result for the first quarter was larger than the sample error but was less than the minimum detectable concentration (MDC) of 4.87 pCi/I. Each year the Land Use Census is used to identify locations of milk animals that should be included in the monitoring program. It is performed annually and is maintained by observations, door-to-door surveys and consulting with local agriculture authorities. The 2015 census is listed in Appendix A. If a new dairy farm is identified close enough to Millstone to be considered an indicator location, the collection of cow milk at that location would be added. 4.7 Well Water (Table 7) There were no station related radioactivity detected in the samples collected as part of the REMP. Zn-65 in Well #77 sample of December 7 has a reported value which is greater than 1.5 times the 2a error. This value is a result of counts from the natural nuclide Bi-214 in the 1121 Kev peak spilling into the Zn-65 peak at 1116 Kev. Nb-95 in Well #82 samples of June 22 and December 10 had a reported value which are greater than 1.5 times the 2a error. Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. Additional samples from this well, and other wells, were obtained as part of the Groundwater Protection Program (GWPP). Results from the GWPP are reported in the Millstone annual "Radioactive Effluent Release Report" for 2015. 4.8 Fruits and Vegetables (Table 8) Consistent with past years, this media did not show any station effects. Naturally occurring K-40 was detected in all samples. 4.9 Broad Leaf Vegetation (Table 9) Consistent with past years, this media did not show any station effects. Most 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 in the past. This can be attributed to fallout from weapons testing which has been widespread in terrestrial samples for many years. 4-6

Dominion Nuclear Connecticut, Inc. Millstone Power Station 4.10 Seawater (Table 10) Annual Radiological Environmental Operating Report 2015 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 Millstone has been located in the vicinity of discharge (Location 32) 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. Any dose consequences can be assessed by use of the appropriate dilution factors. It's not necessary to have a continuous sampler at the control location due to the historical relative consistency noted in seawater background activity near the Millstone. A technician collects an aliquot from the automatic sampler at Location 32 on a weekly frequency. These samples are composited for monthly analyses. For the Control Location, Giant's Neck (Location 37C), six weekly grab samples are obtained for quarterly compositing. Naturally occurring K-40 was the only detectable gamma activity seen in these samples. Nb-95 in the samples of April 28 and July 28 at Location 32 have a reported value which are greater than 1.5 times the 2cr error. In both cases, extra counts were detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. Measured station related levels of H-3 in seawater from the vicinity of discharge (Location 32) were observed in most samples. Tritium releases are typically higher near 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. Tritium builds up in the reactor coolant during each fuel cycle. It is generated during station 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 Millstone liquid effluents versus the measured environmental concentrations from the vicinity of discharge location. 4-7

Dominion Nuclear Connecticut, Inc. Millstone Power Station Annual Radiological Environmental Operating Report 2015 Figure 4.14-1 H-3 Curies Released versus Seawater Concentration 18 Year Trend 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 I\\ Iii I .... *"I' -11 ~ .JI ~ - ~ I * } I l'i... I. '\\ 71 I I.Dl\\ -- \\ f.,. IDL~ I u \\I * "I 0 I .~ ' ~ rl lo ~ 4.11 Bottom Sediment (Table 11) I... "'1 I I I I.. 4t \\ ~ Cmies discba[ged -- REMP pl!i!liter I ~ I I I 1 ~

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