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 Serial No. 16-166 Attention: Document Control Desk MPS Lic/AVM RO Washington, DC 20555-0001 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 DOMINION NUCLEAR CONNECTICUT, INC. MILLSTONE POWER STATION UNITS 1, 2, AND 3 2015 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT 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

Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 2of4 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 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

Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 3of4 (2copies) Director Bureau of Air Management Monitoring & Radiation Division 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

Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 4 of 4 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 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 ATTACHMENT 1 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015

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

SUMMARY

INTRODUCTION 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015

1. INTRODUCTION 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. Annual Radiological Environmental Operating Report Millstone Power Station 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 MAN-MADE Radiation Dose Radiation Dose Source (mrem/vear) Source (mrem/year) Internal, inhalation<2l 228 Medica1(3l 300 External, space 33 Consumer(4l 13 Internal, ingestion 29 Industrial, security, 0.3 educational, research External, terrestrial 21 Occupational 0.5 Weapons Fallout < 1 Nuclear Power Stations < 1 Approximate Total 311 Approximate Total 314 {1) information from References 3 and 4 (2) from radon and thoron (3) includes computerized tomography (147 mrem), nuclear medicine (77 mrem), interventional fluoroscopy (43 mrem) and conventional radiography and fluoroscopy (33 mrem) (4) primarily from cigarette smoking (4.6 mrem), commercial air travel (3.4 mrem), building materials (3.5 mrem) and mining and agriculture (0.8 mrem) 1-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annu al Radiological Environmental Operating Report Millstone Power Station 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 Lig ht Water Reactor (LWR)

                                                             * ~----------.....,* co NO ENSER COO UNG WATER
                                                             -.;;...;,;;;,,;;,;,,;;;;,;;i;iiii0ii_ _,TA.KiNC WASTE HEAT TOTHE ENViRONMEN't Figure 1.4-1 1-4

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

Uranium 1.,... Neutrons WlllJJ Neutron Uranium Fission Products Uranium Fission Products Figure 1.4-2 Radioactive Fission Product Formation 1-5

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

                          *col.ii~icm

with 0

                      .                                                  **~

Co-60 stable Radioactive.

co6alt Nucleus *cci*balt::Ntic1eus Figure 1.4-3 Radioactive Activation Product Formation 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. Annual Radiological Entjronmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 1.5 Radioactive Effluent Control The small amounts of radioactive liquids arid gases that might escape the first two barriers 1 are processed in the liquid and gaseous waste treatment systems, then monitored for radioactivity, and released only if the radioactivity levels are below the federal release limits. Radioactivity released from the liquid effluent system to the environment is limited, controlled, and monitored by a variety of systems and procedures which include:

reactor water cleanup system;
liquid radwaste treatment system;
sampling and analysis of the liquid radwaste tanks; and,
liquid waste effluent discharge radioactivity monitor.

The purpose of the reactor water cleanup system is to continuously purify the reactor cooling water by removing radioactive atoms and non-radioactive impurities that may become activated by neutron bombardment. A portion of the reactor coolant water is diverted from the primary coolant system and is directed through ion exchange resins where radioactive elements, dissolved and suspended in the water, are removed through chemical processes. The net effect is a substantial reduction of the radioactive material that is present in the primary coolant water and consequently the amount of radioactive material that might escape from the system. Reactor cooling water that might escape the primary cooling system and other radioactive water sources are collected in floor and equipment drains. These drains direct this radioactive liquid waste to large holdup tanks. The liquid waste collected in the tanks is purified again using the liquid radwaste treatment system, which consists of a filter and ion exchange resins. Processing of liquid radioactive waste results in large reductions of 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 EXAMPLES OF Millstone's RADIATION EXPOSURE PATHWAYS LIQUID EFFLUENTS

3. DIRECT RADIATION (STATIO~ 2. AIR INHALATION ef /V"" / 1. DIRECT RADIATION

                                                 . *e        LY                e;sMERs10NJ
                                                ~

1. SHORELINE DIRECT RADIATION (FISHING, PICNICJNG) ~

4.-

5. CONSUMPTION (VEGETATION) t DEPOSITION

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

(/

                                                                 &B:m; ~

DEPOSITION INGESTION

3. CONSUMPTION (FISH, SHELLFISH)

Figure 1.6 Radiation Exposure Pathways 1-11

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

2. PROGRAM DESCRIPTION 2.1 Sampling Schedule and Locations 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 Table 2-1 Environmental Monitoring Program Sampling Types and Locations

.:;::.;::::::;:,:c::;: Onsite - Old Millstone Rd. 0.6 Mi, NNW TLD, Air Particulate, Iodine, Vegetation Onsite - Weather Shack 0.3 Mi, S TLD, Air Particulate, Iodine Onsite - Bird Sanctuary 0.3 Mi, NE TLD, Air Particulate, Iodine, Soil Onsite - Albacore Drive 1.0 Mi, N TLD, Air Particulate, Iodine, Soil Onsite - MP3 Discharge 0.1 Mi, SSE TLD Onsite - Quarry Discharge 0.3 Mi, SSE TLD Onsite - Env. Lab Dock 0.3 Mi, SE TLD Onsite- Env. Lab 0.3 Mi, SE TLD Onsite - Bay Point Beach 0.4 Mi, W TLD

 ..,. *.:***'"*****""' Pleasure Beach                    1.2 Mi, E          TLD, Air Particulate, Iodine, Vegetation Great Neck Country Club    1.6 Mi, ENE        TLD, Air Particulate, Iodine Fisher's Island, NY        8.0 Mi, ESE        TLD Mystic, CT                 11.5 Mi, ENE       TLD Ledyard, CT                12.0 Mi, NE        TLD, Soil Norwich, CT                14.0 Mi, N         TLD, Air Particulate, Iodine
 '*""'""""""'           Old Lyme, CT               8.8Mi,W            TLD Site Boundary              0.5 Mi, NE         Vegetation Cow                        10.5 Mi, WNW        Milk Within 10 Miles            < 10 Miles         Vegetation 3

Within 10 Miles < 10 Miles Fruits and/or Vegetables Beyond 10 Miles > 10 Miles Vegetation . 3

  ..........~"*"""***         Beyond 10 Miles            > 10 Miles          Fruits and/or Vegetables Niantic                    1.?Mi, WNW         TLD, Air Particulate, Iodine 4

Two Tree Island 0.8Mi, SSE Fish West Jordan Cove 0.4 Mi, ENE-ESE Clams, Fish4 West Jordan Cove 0.4 Mi, NNE Fucus '*'"'""*"'***.<**>.*'"** Niantic Shoals 1.8 Mi, NW Bottom Sediment, Oysters 4 Vicinity of Discharge < 0.1 Mi Bottom Sediment, Oysters, Fish , Seawater Vicinity of Discharge < 0.1 Mi Fucus Seaside Point 1.8 Mi, ESE Bottom Sediment Niantic Bay <0.5 Mi, SSW-W Lobster, Fish 4 Niantic Bay 0.3 Mi, WNW Fucus Black Point 3.0Mi,WSW Fucus

 ,.,;.;;:,;,,;;;:*>:":.:*,    Giant's Neck               3.5 Mi, WSW         Bottom Sediment, Oysters, Seawater Waterford Shellfish Bed #1 1.0 Ml, NW         Clams Myrock Avenue              3.2 Mi, ENE        TLD Billow Road                2.4 Mi, WSW        TLD Black Point                2.6 Mi, SW         TLD Onsite - Schoolhouse       0.1 Mi, NNE        TLD Onsite - Access Road       0.5 Mi, NNW        TLD
   ....... .,..........,."'". Old Lyme - Hillcrest Ave. 4.6Mi,WSW          TLD East L me - W. Main St. 4.5Mi,W            TLD 2-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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 5 MW-GPl-1 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. Annual Radiological Environmental Operating Report Millstone Power Station 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- 39 1 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 Figure 2.1, "Inner TLD, Air, Grass, Soil, and Aquatic Locations" 2-5

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

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

3. RADIOCHEMICAL RES ULTS 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. RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

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

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Medium or Indicator Control Pathway Analysis Total LLD Locations Location with Highest Mean Locations Sampled Type Numbe1 Note1 Distance Mean Mean llUnitsl Well Water H-3 27 2000 Mean (Ranael

                                                          <LLD Number NA I   Direction NA I       (Ranael
                                                                                                         <LLD (Ranae)

NA (pCi//) GAMMA 27 K-40 NA 103- Note 5 78 Down-gradient 127 NA (91 -127) of ISFSI One sample Other Note6 <LLD NA NA <LLD NA Gammas Fruits & Vegetables GAMMA 9 (pCilgwet) K-40 NA 1.629 26 Beyond 1Omiles 1.747 1.747 (0.809 - 2.069) (0.803-3.199) (0.803 - 3.199) Other Note? <LLD NA NA <LLD <LLD Gammas Broad Leaf Vegetation GAMMA 8 (pCi!g wet) BE-7 NA 0.719 0.6Mi. 0.884 1.032- Note 8 (0.485 - 0.959) NNW (0.808 - 0.959) (1.021 -1.42) K-40 NA 4.275 10 1.2 Mi. 5.596 3.533 (2.840 - 7.607) E (3.584 - 7 .607) (3.261 - 3.805) Other Note9 <LLD NA NA <LLD <LLD Gammas Sea Water H-3 16 NA 530 - Note 10 32 On site 530 - Note 10 <LLD (pCil/) (205-1190) (205-1190) GAMMA 16 K-40 NA 317-Note11 32 Onsite 317-Note11 282 (238 -448) (238 -448) (203-370) Other Note6 <LLD NA NA <LLD <LLD Gammas Bottom Sediment GAMMA 10 (pCi/g dry} K-40 NA 15.5 34 4.0Mi. 17.08 15.25 (13.06 -19.94) ENE 14.22-19.94 (12.45 - 18.05) Ac-228 NA 1.25- Note 12 31 1.8Mi. 1.24 <LLD (0.61 -2.16) NW (0.31 -2.16) Other Note3 <LLD NA NA <LLD <LLD Gammas Aquatic Flora - Note 13 GAMMA 20 (pCi!g wet) BE-7 NA 0.203 - Note 14 29 <0.5Mi. 0.267 - Note15 <LLD (0.139 - 0.267) ENE to ESE (0.197 - 0.267) K-40 NA 6.98 32 On site 7.82 6.60 (6.02 - 9.45) (6.30 - 9.45) (6.02 -7.11) Ac-228 NA 0.113 - Note 16 29 <0.5 Mi. 0.123 - Note 17 0.090 - Note 18 (0.072 - 0.142) ENE to ESE (0.098 - 0.142) Other Note? <LLD NA NA <LLD <LLD Gammas 3-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 RADIOLOCIAL ENVIRONMENT MONITORING PROGRAM

SUMMARY

MILLSTONE POWER STATION Dockets 50-245, 50-336 & 50-423 2015 Medium or Indicator Control Pathway Analysis Total LLD Locations Location with Highest Mean Locations Sampled (Units) Fish Type GAMMA Number Note 1 7 Mean (Range) Number I Distance Direction I Mean (Range) Mean (Rangel (pCi/gwet) K-40 NA 4.41 32 <0.5Mi. 5.16 NA (3.78-5.31) (5.00 - 5.31) other Note 19 <LLD NA NA <LLD NA Gammas Oysters GAMMA 16 (pCi!g wet) K-40 NA 2.18 31 1.8 Mi. 2.33 2.34 (1.54 -2.78) NW (2.23 - 2.52) (2.20 - 2.58) Other Note 19 <LLD NA NA <LLD <LLD Gammas Clams GAMMA 7 (pCi!g wet) K-40 NA 2.22 29 <0.5Mi. 2.30 NA (1.77 -2.78) ENE to ESE (1.77 - 2.78) Other Nole 19 <LLD NA NA <LLD NA Gammas Lobster GAMMA 8 (pCi/g wet) K-40 NA 2.83 35 <0.5Mi. 2.83 2.92 (2.36 - 3.12) SSWtoW (2.36 - 3.12) (2.54 - 2.69) other Note 19 <LLD NA NA <LLD NA Gammas NOTES FOR

SUMMARY

TABLE 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. 3 3 2 - LLDs for air particulate other gamma are 0.05 pCi/M for Cs-134 and 0.06 pCi/M 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. 3 7 - LLDs for fruits & vegetables, broadleaf vegetation and aquatic flora for other gamma are 0.06 pCi/M 3 3 for 1-131, 0.06 pCi/M for Cs-134 and 0.08 pCi/M 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 NOTES FOR

SUMMARY

TABLE (Continued} 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 3.2 Data Tables 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 1 QUARTERLY GAMMA EXPOSURE RATE (uR/hr)* LOCATIONS (C =control, background locations; X =extra locations not required by REMODCM) PERIOD 1 4 8 (+/~) 2 (+/-) 3 (+/-) (+/-) 5 (+/-) 6 (+/-) 7 (+/-) (+/-) 9 (+/-) 10 (+/-) 11 (+/-) 1Q 7.2 0.6 9.2 0.8 6.6 0.5 6.9 0.7 8.2 0.8 8.3 0.7 6.1 0.5 9.6 0.8 9.1 1.0 9.4 0.7 6.1 0.8 2Q 7.8 0.5 9.9 0.5 6.8 0.6 7.4 0.5 9.3 6.6 8.7 0.4 4.9 0.3 11.3 0.7 11.3 0.9 9.1 0.5 7.0 0.5 3Q 8.0 0.6 9.4 0.9 7.4 0.6 7.0 0.8 9.4 0.9 8.4 0.6 4.4 0.4 10.9 0.8 11.0 0.8 8.1 0.8 6.4 0.5 4Q 8.1 0.6 9.9 0.7 8.2 0.6 8.0 0.6 9.6 0.9 9.1 0.6 5.1 0.4 11.6 0.9 11.9 0.9 9.2 0.6 7.3 0.6 PERIOD 12X 13C 15C 16C 27 42 44 (+/-) (+/-) 14C (+/-) (+/-) (+/-) (+/-) 41 (+/-) (+/-) 43 (+/-) (+/-) 45 (+/-) 1Q 6.6 0.7 7.0 0.6 7.3 0.5 6.7 0.7 5.7 0.6 8.6 1.2 6.3 0.5 5.8 0.6 ~.5 0.5 7.8 0.6 6.6 0.7 2Q 7.0 0.4 . 8.5 0.7 9.1 0.5 7.4 0.4 6.1 0.5 7.1 0.5 6.3 0.3 7.1 0.4 7.3 0.8 7.9 0.5 7.1 0.5 3Q 7.2 0.8 8.2 0.7 8.6 0.6 7.4 0.6 5.9 0.4 7.1 0.8 6.2 0.6 7.0 0.7 6.9 0.6 7.4 0.9 7.1 0.7 4Q 7.3 0.6 9.4 0.9 9.2 0.7 8.5 0.5 6.5 0.6 8.0 0.6 6.7 0.8 7.7 0.6 7.4 0.5 8.6 0.7 7.7 0.7 PERIOD 46 47 48 51 52 53 55 (+/-) (+/-) (+/-) 49 (+/-) 50 (+/-) (+/-) (+/-) (+/-) (+/-) 56 (+/-) 57 (+/-) 1Q 6.5 0.8 6.8 0.8 8.2 0.8 6.0 0.6 6.6 0.7 5.6 0.4 6.2 0.7 6.3 0.6 7.2 0.6 6.5 0.5 6.0 0.6 2Q 8.7 0.6 7.5 0.7 9.4 0.6 6.8 0.5 7.3 0.5 6.0 0.6 7.1 0.6 7.1 0.5 7.2 0.6 6.9 1.2 7.2 0.5 3Q 7.7 0.7 7.4 0.7 9.1 0.7 6.6 0.6 7.2 0.5 5.9 0.4 6.8 0.8 6.9 0.5 6.9 0.6 6.6 0.6 7.2 0.7 4Q 8.7 0.8 8.1 0.6 9.8 0.8 6.9 0.5 7.8 0.8 6.4 0.5 7.5 0.6 7.6 0.6 7.4 0.5 7.2 0.6 7.1 0.6 PERIOD 59 60 61 62 63 64 65 73X 74X (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 66X (+/-) (+/-) (+/-) 75X (+/-) 1Q 6.7 0.6 5.9 0.6 6.0 0.4 6.6 0.7 7.5 0.8 6.6 0.7 6.8 0.6 7.0 0.6 7.3 1.0 6.6 0.6 6.2 0.5 2Q 7.9 0.5 6.9 0.4 7.0 0.8 7.9 0.5 8.2 0.5 7.3 0.7 8.0 0.8 7.1 0.4 7.6 0.6 7.6 0.5 6.6 0.4 3Q 7.7 0.7 6.7 0.5 7.3 0.8 7.9 0.6 8.4 0.9 7.5 0.6 7.8 0.5 7.2 0.6 7.8 0.7 7.5 0.6 6.7 0.6 4Q 7.9 0.6 6.5 0.5 7.3 0.5 8.0 0.8 8.3 1.2 7.2 0.6 8.0 0.7 7.5 0.6 8.2 0.7 7.7 0.6 6.9 0.5

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

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 2 AIR PARTICULATES GROSS BETA RADIOACTIVITY 3 (pCi/m ) LOCATIONS (C =control, background location) PERIOD ENDING 01

                     *----------r+t:;--*         02                  03                 04                  10                 11
                                         ----------f+i'..r-* ----------r+1.r-- *----------(+i:;--* ----------f+i'..r-* ----------(+1.;---

27

                                                                                                                                          *---------(+i~}--* ----------,+,:r-*

15C 01/13/15 0.016 0.002 0.015 0.002 o.014 0.002 0.014 0.002 0.015 0.002 0.015 0.002 0.014 0.002 0.014 0.002 01/26/15 0.014 0.002 0.013 0.002 0.012 0.002 0.012 0.002 0.013 0.002 0.014 0.002 0.015 0.002 0.013 0.002 02/10/15 0.016 0.002 0.015 0.002 0.014 0.002 0.015 0.002 0.015 0.002 0.015 0.002 0.016 0.002 0.013 0.002 02/24/15 0.018 0.002 0.018 0.002 0.021 0.002 0.019 0.002 0.020 0.002 0.018 0.002 0.017 0.002 0.020 0.002 03/10/15 0.018 0.002 0.018 0.002 O.Q18 0.002 0.021 0.003 0.020 0.002 0.021 0.002 0.020 0.002 0.019 0.002 03/24/15 0.010 0.002 0.011 0.002 0.012 0.002 0.011 0.002 0.012 0.002 0.011 0.002 0.012 0.002 0.013 0.002 04/07/15 0.013 0.002 0.012 0.002 0.014 0.002 0.016 0.002 0.014 0.002 0.015 0.002 0.015 0.002 0.014 0.002 04/21/15 0.019 0.002 0;011 0.002 0.010 0.002 0.010 0.002 0.009 0.002 0.010 0.002 0.011 0.002 0.009 0.002 05/05/15 0.007 0.002 0.006 0.002 0.005 0.002 0.005 0.001 0.008 0.002 0.007 0.002 0.004 0.001 0.007 0.002 05/19/15 0.021 0.002 0.015 0.002 0.016 0.002 0.017 0.002 0.015 0.002 0.018 0.002 O.Q18 0.002 0.019 0.002 06/02115 0.012 0.002 0.010 0.002 0.011 0.002 0.010 0.002 0.011 0.002 0.014 0.002 0.014 0.002 0.011 0.002 06/16/15 0.010 0.002 0.006 0.001 0.006 0.002 0.008 0.002 0.009 0.002 0.008 0.002 0,.007 0.001 0.008 0.002 06/30/15 0.010 0.002 0.006 0.001 0.007 0.002 0.007 0.002 0.007 0.002 0.008 0.002 0.008 0.002 0.011 0.002 07/14/15 0.010 0.002 0.010 0.002 0.013 0.002 0.014 0.002 0.012 0.002 0.012 0.002 0.012 0.002 0.012 0.002 07/28/15 0.013 0.002 0.010 0.002 0.012 0.002 0.011 0.002 0.011 0.002 0.013 0.002 0.011 0.002 0.013 0.002 08/11/15 0.013 0.002 0.014 0.002 0.014 0.002 0.015 0.002 0.015 0.002 0.013 0.002 0.012 0.002 0.014 0.002 08/25/15 0.016 0.002 0.013 0.002 0.012 0.002 0.015 0.002 0.012 0.002 0.016 0.002 0.015 0.002 0.014 0.002 09/08/15 0.022 0.002 0.020 0.002 0.021 0.003 0.023 0.003 0.019 0.002 0.020 0.002 0.021 0.002 0.021 0.003 09/22/15 0.019 0.002 0.017 0.002 O.Q18 0.002 0.019 0.002 0.017 0.002 0.019 0.002 0.017 0.002 0.017 0.002 10/06/15 0.010 0.002 0.010 0.002 0.009 0.002 0.010 0.002 0.008 0.002 0.010 0.002 0.009 0.002 0.012 0.002 10/20/15 0.012 0.002 0.012 0.002 0.013 0.002 0.012 0.002 0.011 0.002 0.011 0.002 0.011 0.002 0.012 0.002 11/03/15 0.015 0.002 0.012 0.002 0.016 0.002 0.013 0.002 0.012 0.002 0.013 0.002 0.014 0.002 0.015 0.002 11/17/15 0.018 0.002 0.017 0.002 0.018 0.002 0.019 0.002 0.017 0.002 0.017 0.002 0.019 0.002 0.017 0.002 12/01/15 0.012 0.002 0.015 0.002 0.011 0.002 0.012 o.qo2 0.013 0.002 0.012 0.002 0.012 0.002 0.014 0.002 12/15/15 0.023 0.002 0.021 0.002 0.021 0.002 0.021 0.002 0.021 0.002 0.023 0.002 0.023 0.002 0.020 0.002 12/29/15 0.011 0.002 0.010 0.002 0.008 0.002 0.010 0.002 0.010 0.002 0.010 0.002 0.013 0.002 0.011 0.002 3-9

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 3 AIRBORNE IODINE (1-131) 3 (pCi/m ) LOCATIONS (C =control, background location) PERIOD 01 02 03 15C ENDING

                   ----------i~i~l---- *----------~i=i*-- *----------i;i-i             04

__ _ ----------(.;:ff*-* 10

                                                                                                    -----------(.;:i_r--*         11
                                                                                                                          ----------(;ff*-*         27
                                                                                                                                            ----------i~i~,---- *----------r.iT--

01/13/15 0.006 0.007 0.007 0.008 0.006 0.007 0.007 0.008 -0.004 0.008 -0.003 0.008 -0.004 0.009 -0.004 0.008 01/26/15 0.000 O.Q15 0.000 O.Q18 0.000 0.015 0.000 0.018 0.010 0.016 0.009 O.Q15 0.011 0.018 0.010 0.016 02/10/15 -0.011 0.028 -0.014 0.036 -0.012 0.030 -0.015 0.036 0.003 0.033 0.003 0.030 0.004 0.040 0.003 0.034 02/24/15 -0.001 0.006 -0.001 0.007 -0.001 0.006 -0.001 0.007 0.003 0.006 0.003 0.005 0.003 0.006 0.003 0.006 03/10/15 -0.006 0.030 -0.006 0.035 -0.006 0.030 -0.007 0.036 0.003 0.033 0.002 0.029 0.003 0.037 0.003 0.035 03/24/15 -0.022 0.020 -0.025 0.022 -0.022 0.020 -0.026 0.024 -0.002 0.Q18 -0.002 0.016 -0.003 0.020 -0.003 0.020 04/07/15 0.006 0.017 0.007 0.019 0.006 0.017 0.007 0.020 0.007 0.010 0.006 0.009 0.008 0.011 0.007 0.011 04/21/15 0.004 0.011 0.011 0.032 0.009 0.028 0.010 0.030 0.010 0.028 0.004 0.025 0.005 0.033 0.004 0.028 05/05/15 -0.005 0.014 -0.006 0.016 -0.005 O.Q15 -0.005 0.014 0.007 0.015 0.006 0.014 0.006 O.Q15 0.006 0.014 05/19/15 0.000 0.017 0.000 0.017 -0.001 0.019 -0.001 0.018 -0.011 O.Q18 -0.010 0.017 -0.010 O.Q18 -0.010 0.017 06/02/15 -0.003 0.010 -0.003 0.010 -0.003 0.012 -0.003 0.011 0.014 0.019 0.013 0.017 0.015 0.020 0.013 0.017 06/16/15 0.021 0.029 0.021 0.029 0.023 0.032 0.022 0.031 0.002 0.034 0.002 0.030 0.002 0.027 0.002 0.029 06/30/15 0.002 0.011 0.002 0.011 0.002 0.013 0.002 0.012 0.001 0.005 -0.002 0.010 -0.002 0.010 -0.002 0.011 07/14/15 0.003 0.007 0.003 0.008 0.004 0.009 0.004 0.008 0.010 0.008 0.009 0.008 0.009 0.008 0.009 0.008 07/28/15 -0.004 0.006 -0.004 0.006 -0.005 0.007 -0.005 0.006 0.002 0.007 0.002 0.006 0.002 0.006 0.002 0.006 08/11/15 0.005 0.023 0.005 0.023 0.006 0.027 0.006 0.026 -0.019 0.039 -0.017 0.033 -0.017 0.034 -O.Q18 0.035 08/25/15 0.008 0.025 0.008 0.026 0.009 0.030 0.009 0.028 0.016 0.028 O.Q18 0.031 .0.018 0.032 0.018 0.033 09/08/15 -0.001 0.010 -0.001 0.009 -0.001 0.011 -0.001 0.010 0.000 0.003 -0.002 0.011 -0.002 0.011 -0.002 0.012 09/22/15 -0.003 0.019 -0.003 0.019 -0.004 0.022 -0.003 0.021 -0.010 0.019 -0.011 0.021 -0.011 0.021 -0.012 0.022 10/06/15 -0.002 0.011 -0.002 O.Q11 -0.002 0.012 -0.002 0.012 0.001 0.010 0.001 0.011 0.001 0.011 0.001 0.011 10/20/15 0.002 0.024 0.002 0.024 0.002 0.029 0.002 0.027 -O.D18 0.029 -0.020 0.032 -0.021 0.033 -0.021 0.033 11/03/15 -0.007 0.034 -0.007 0.035 -0.009 0.041 -0.008 O.Q38 -0.012 0.034 -0.013 0.038 -0.013 0.038 -0.014 0.040 11/17/15 -0.014 0.028 -O.Q15 0.028 -0.016 0.031 -0.016 0.031 -0.001 0.027 -0.002 0.029 -0.002 0.029 -0.002 0.030 12/01/15 0.011 0.022 0.011 0.022 0.011 0.023 0.012 0.024 0.001 0.032 0.001 0.035 0.001 0.036 0.001 0.036 12/15/15 -0.010 0.023 -0.010 0.024 -0.011 0.025 -0.011 0.026 -0.018 0.036 -0.020 0.039 -0.019 0.038 -0.020 0.040 12/29/15 0.007 0.030 0.007 0.030 0.007 0.032 -0.010 0.031 -0.009 0.027 -0.009 0.029 -0.005 O.Q16 -0.010 0.031 3-10

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE4 AIR PARTICULATES (pCi/m 3 ) (15C =control, background location) GAMMA SPECTRA- QTR 1 (12/30/14 - 04/07/15) LOCATION Be-7 Mn-54 Co-58 Co-60 Zn-65 Nb-95 Zr-95

           ------------- -----------(+7:,----- *-----------r+r.r---*  ------------(+i:j   ____   *-----------c:;:i-r---* ------------r+1:;-*-- -----------1+i=-,----- *-----------r+i-r*--*

01 0.0966 0.0297 0.0005 0.0011 0.0010 0.0019 0.0008 0.0008 0.0028 0.0029 -0.0001 0.0023 0.0031 0.0040 02 0.1600 0.0575 0.0019 0.0104 -0.0077 0.0267 -0.0019 0.0098 0.0141 0.0240 0.0175 0.0274 -0.0384 0.0464 03 0.1307 0.0433 0.0000 0.0017 0.0014 0.0036 0.0010 0.0012 -0.0010 0.0036 0.0030 0.0037 -0.0035 0.0063 04 0.0875 0.0735 ~0.0014 0.0028 -0.0002 0.0039 -0.0016 0.0019 0.0058 0.0066 0.0032 0.0054 -0.0018 0.0091 10 0.1176 0.0531 0.0007 0.0017 0.0020 0.0024 0.0013 0.0018 -0.0005 0.0041 0.0014 0.0035 -0.0014 0.0060 11 0.1253 0.0420 -0.0002 0.0014 -0.0008 0.0022 -0.0005 0.0012 0.0000 0.0029 -0.0021 0.0029 0.0005 0.0049 27 0.1907 0.0667 -0.0014 0.0023 -0.0035 0.0053 0.0002 0.0031 0.0009 0.0046 -0.0024 0.0060 -0.0030 0.0114 15C 0.1265 0.0409 0.0003 0.0014 -0.0022 0.0022 0.0000 0.0009 0.0005 0.0031 0.0007 0.0027 0.0026 0.0042 LOCATION Ru-103 Ru-106 Cs-134 Cs-137 Ba-140 Ce-141 Ce-14.4

           ------------- -----------(+7:,----- *-----------r;:r.r---* ------------Fr---          *-----------c:;:1-r---*  *-----------r+,:r*-- -----------(+i'.y----  *-----------Fi-r---*

01 0.0007 0.0041 -0.0139 0.0131 -0.0001 0.0012 0.0003 0.0010 -0.0020 0.4906 0.0023 0.0078 -0.0003 0.0057 02 0.0407 0.0531 0.0571 0.1124 0.0050 0.0103 -0.0058 0.0106 -0.9744 5.8260 -0.0245 0.0802 0.0383 0.0535 03 -0.0034 0.0057 0.0042 0.0133 0.0002 0.0013 0.0003 0.0015 -0.2647 0.7735 0.0013 0.0098 -0.0017 0.0066 04 0.0002 0.0093 -0.0115 0.0213. 0.0028 0.0021 0.0016 0.0019 -0.1101 1.0220 -0.0053 0.0174 -0.0012 0.0127 10 0.0004 0.0061 0.0031 0.0145 -0.0001 0.0018 -0.0004 0.0015 0.1637 0.7549 0.0025 0.0090 -0.0071 0.0069 11 -0.0059 0.0059 -0.0085 0.0110 -0.0003 0.0011 -0.0003 0.0010 -0.2590 0.5423 0.0033 0.0087 -0.0035 0.0064 27 -0.0048 0.0088 0.0057 0.0250 0.0026 0.0024 0.0007 0.0022 -0.2331 1.1510 0.0009 0.0124 0.0015 0.0086 15C -0.0017 0.0040 -0.0065 0.0100 0.0004 0.0011 -0.0011 0.0010 -0.0005 0.5666 0.0038 0.0082 0.0015 0.0060 GAMMA SPECTRA- QTR 2 (04/07/15 -06/30/15) Be-7 Mn-54 Co-58 Co-60 Zn-65 Nb-95 Zr-95 LOCATION

                         -----------(+7:,----- *-----------r+r.r---*  ------------(+i=j   ____   *-----------Fi-r---* ------------r+1:;-*--    -----------1+1=-i----- *-----------Fi-r---*

01 0.1016 0.0428 0.0002 0.0011 -0.0018 0.0023 -0.0002 0.0013 -0.0001 0.0028 -0.0004 0.0023 -0.0011 0.0037 02 0.1069 0.0277 0.0001 0.0010 -0.0010 0.0026 0.0007 0.0012 0.0011 0.0036 0.0018 0.0028 -0.0073 0.0050 03 0.1275 0.0537 0.0001 0.0023 0.0005 0.0050 0.0007 0.0024 0.0038 0.0065 0.0035 0.0049 -0.0032 0.0082 04 0.1406 0.0476 0.0003 0.0017 0.0009 0.0032 -0.0012 0.0014 0.0015 0.0037 0.0006 0.0035 0.0015 0.0056 10 0.1192 0.0507 0.0007 0.0021 0.0011 0.0034 0.0004 0.0019 0.0036 0.0041 -0.0004 0.0036 *0.0010 0.0068 11 0.1099 0.0413 0.0001 0.0012 0.0006 0.0015 0.0007 0.0009 0.0003 0.0023 -0.0018 0.0025 0.0036 0.0039 27 0.1061 0.0382 -0.0011 0.0015 0.0002 0.0024 0.0005 0.0011 0.0002 0.0035 0.0019 0.0028 0.0017 0.0049 15C 0.1433 0.0394 0.0002 0.0016 0.0000 0.0026 0.0005 0.0016 0.0009 0.0039 -0.0012 0.0031 0.0013 0.0054 Ru-103 Ru-106 Cs-134 Cs-137 Ba-140 Ce-141 Ce-144 LOCATION

                         -----------(+1:,*---* *----------*r+1:r*--*  -----------*Fr**-          *-----------<+1-r*--*    ------------f+,:r*-- -----------1+1:-i--*-- *-----------Fi-r**-*

01 0.0022 0.0037 0.0033 *0.0090 0.0007 0.0011 0.0006 0.0013 0.0007 0.3877 0.0083 . 0.0071 0.0026 0.0054 02 *0.0013 0.0049 *0.0058 0.0113 0.0008 0.0013 0.0012 0.0009 *0.1350 0.4362 *0.0010 0.0070 0.0023 0.0057 03 0.0065 0.0074 *0.0100 0.0225 0.0020 0.0020 -0.0007 0.0020 0.0380 0.8127 0.0083 0.0097 -0.0028 0.0061 04 -0.0023 0.0055 0.0089 0.0105 *0.0006 0.0013 -0.0003 0.0014 -0.1254 0.5343 0.0004 0.0088 0.0023 0.0073 10 0.0042 0.0080 0.0110 0.0145 0.0009 0.0017 0.0002 0.0017 0.2946 0.6238 *0.0023 0.0109 0.0003 0.0090 11 . *0.0006 0.0035 0.0012 0.0088 0.0003 0.0011 *0.0003 0.0009 0.2200 0.3246 -0.0009 0.0066 *0.0032 0.0054 27 *0.0012 0.0041 -0.0017 0.0104 0.0019 0.0013 *0.0004 0.0010 *0.1183 0.4492 0.0025 0.0072 0.0029 0.0065 15C -0.0057 0.0055 0.0163 0.0143 0.0015 0.0015 *0.0003 0.0012 0.4738 0.4849 0.0018 0.0096 0.0042 0.0077 3-11

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE4 AIR PARTICULATES (pCi/m 3 ) GAMMA SPECTRA- QTR 3 (06/30/15 - 10/06/15) LOCATION Be-7

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

Mn-54

                                              *-----------r+i-r---*         Co-58
                                                                    ------------(+i:r---              Co-60
                                                                                             *-----------Fi~-----

Zn-65

                                                                                                                  ------------r+q----            Nb-95
                                                                                                                                         -----------(+j:,-----          Zr-95
                                                                                                                                                               *-----------Fi-r---*

01 0.1339 0.0457 -0.0006 0.0018 -0.0013 0.0035 -0.0004 0.0014 0.0027 0.0037 -0.0011 0.0036 -0.0036 0.0063 02 0.0960 0.0348 0.0004 0.0011 -0.0010 0.0022 0.0002 0.0009 0.0029 0.0030 0.0018 0.0021 0.0009 0.0040 03 0.1214 0.0318 -0.0002 0.0010 0.0015 0.0024 0.0007 0.0010 0.0019 0.0040 0.0017 0.0026 -0.0021 0.0046 04 0.1185 0.0426 -0.0011 0.0009 -0.0004 0.0022 -0.0010 0.0010 -0.0017 0.0030 0.0012 0.0028 -0.0010 0.0044 10 0.1136 0.0321 -0.0007 0.0010 -0.0004 0.0026. 0.0011 0.0012 0.0017 0.0033 0.0020 0.0028 -0.0017 0.0052 11 0.0862 0.0288 -0.0005 0.0012 -0.0013 0.0025 -0.0001 0.0013 0.0038 0.0032 0.0002 0.0029 0.0003 0.0051 27 0.1839 0.0422 -0.0002 0.0011 0.0002 0.0025 -0.0006 0.0008 -0.0012 0.0027 -0.0006 0.0026 -0.0028 0.0051 15C 0.1264 0.0549 -0.0008 0.0019 -0.00'20 0.0031 0.0014 0.0016 0.0015 0.0045 0.0022 0.0045 -0.0024 0.0077 LOCATION Ru-103

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

Ru-106

                                              *-----------r+i-r---*         Cs-134
                                                                    -----------(+i:i ____             Cs-137
                                                                                             *-----------Fi-r---* ------------r+1:j Ba-140

____ Ce-141

                                                                                                                                         -----------(+i=,-----         Ce-144
                                                                                                                                                               *-----------,+i-r---*

01 -0.0027 0.0069 0.0040 0.0140 0.0025 0.0020 -0.0003 0.0015 -0.0247 0.8042 -0.0034 0.0098 0.0013 0.0074 02 0.0012 0.0041 0.0081 0.0094 0.0008 0.0012 -0.0001 0.0010 -0.0282 0.3596 -0.0006 0.0071 -0.0011 0.0047 03 0.0009 0.0042 0.0035 0.0101 0.0035 0.0014 0.0010 0.0010 -0.1019 0.5216 -0.0050 0.0082 0.0010 0.0059 04 -0.0005 0.0041 -0.0010 0.0105 -0.0010 0.0012 0.0010 0.0011 -0.0016 0.4223 -0.0040 0.0082 -0.0049 0.0054 10 0.0043 0.0042 -0.0062 0.0114 0.0013 0.0012 -0.0004 0.0010 0.0965 0.5611 -0.0002 0.0080 0.0017 0.0055 11 0.0000 0.0051 -0.0017 0.0107 0.0008 0.0011 0.0000 0.0008 0.0875 0.6066 0.0007 0.0086 0.0000 0.0062 27 -0.0069 0.0039 -0.0028 0.0115 -0.0003 0.0011 0.0008 0.0012 -0.1457 0.5858 -0.0028 0.0077 -0.0031 0.0056 15C 0.0004 0.0077 -0.0051 0.0147 0.0005 0.0018 -0.0010 0.0018 0.0188 0.8558 -0.0035 0.0105 0.0038 0.0076 GAMMA SPECTRA- QTR 4 (10/06/15 - 12/29/15) LOCATION Be-7

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

Mn-54

                                              *-----------f+i-r---*         Co-58
                                                                    -----------(+i:i____              Co-60               Zn-65
                                                                                             *-----------Fi-r---* ------------r+q----            Nb-95
                                                                                                                                         -----------(+i=,----- *-----------(+i-i Zr-95 01        0.0940     0.0301      0.0004    0.0014     0.0017    0.0019          0.0005    0.0011    0.0022     0.0030     -0.0010    0.0021       0.0015    0.0036 02        0.1001     0.0361     -0.0004    0.0020     0.0006    0.0033        -0.0008     0.0023    0.0062     0.0057     -0.0009    0.0035      -0.0002    0.0067 03        0.0843     0.0381      0.0003    0.0011    -0.0028    0.0027          0.0022     0.0016  -0.0033     0.0036     -0.0015    0.0031       0.0039    0.0042 04        0.0961     0.0422      0.0000    0.0014    -0.0014    0.0029        -0.0012     0.0013    0.0017     0.0033      0.0006    0.0026       0.0004    0.0048 10        0.1010     0.0352      0.0004    0.0018     0.0010    0.0031          0.0004    0.0013    0.0021     0.0045     -0.0004    0.0032      -0.0019    0.0057 11        0.1020     0.0298     -0.0001    0.0012    -0.0006    0.0026        -0.0002     0.0013   -0.0007     0.0030     -0.0001    0.0023       0.0044    0.0044 27        0.1090     0.0338      0.0005    0.0012    -0.0008    0.0014          0.0004    0.0005   -0.0004     0.0026     -0.0007    0.0018      -0.0006    0.0029 15C        0.0717     0.0312      0.0001    0.0011    -0.0016    0.0020        -0.0002      0.0009   0.0034     0.0029      0.0005    0.0021      -0.0010    0.0040 LOCATION            Ru-103
                        -----------(+i=,-----         Ru-106
                                              *-----------f+i-r---*         Cs-134
                                                                    -----------(+i:r---               Cs-137
                                                                                             *-----------Fi-r---*         Ba-140
                                                                                                                  ------------r+,:r---          Ce-141
                                                                                                                                         -----------(+i~-----

Ce-144

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

01 -0.0002 0.0037 0.0032 0.0119 0.0014 0.0012 0.0002 0.0010 0.0238 0.2170 0.0031 0.0065 -0.0031 0.0068 02 -0.0032 0.0070 0.0035 0.0201 0.0015 0.0019 0.0007 0.0020 -0.2509 0.3692 0.0104 0.0081 -0.0075 0.0085 03 0.0019 0.0043 0.0052 0.0115 -0.0001 0.0014 -0.0005 0.0013 -0.0790 0.2377 -0.0076 0.0075 0.0051 0.0074 04 0.0003 0.0042 -0.0101 0.0128 0.0013 0.0013 0.0002 0.0012 0.1546 0.2243 -0.0018 0.0063 -0.0029 0.0059 10 -0.0019 0.0048 -0.0045 0.0145 0.0006 0.0019 0.0006 0.0014 -0.1319 0.3111 -0.0020 0.0077 -0.0008 0.0081 11 -0.0014 0.0039 -0.0110 0.0116 0.0005 0.0011 0.0009 0.0011 -0.0540 0.2216 -0.0025. 0.0064 -0.0032 0.0071 27 -0.0013 0.0034 0.0009 0.0087 -0.0005 0.0010 0.0002 0.0008 0.0260 0.2191 0.0010 0.0053 -0.0013 0.0054 15C 0.0004 0.0032 0.0084 0.0086 -0.0005 0.0009 0.0007 0.0009 0.1427 0.1942 0.0028 0.0055 0.0011 0.0052 3-12

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 5 SOIL (pCi/g dry wt.) COLLECTION LOCATION DATE Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 03 11/03/15 0.120 0.534 13.100 1.587 -0.122 0.599 0.008 0.054 -0.016 0.051 -0.040 0.124 04 11/03/15 0.084 0.777 15.110 3.027 -1.040 0.932 0.031 0.098 -0.036 0.099 0.037 0.208 14C 11/03/15 0.323 0.820 13.750 2.354 0.038 0.999 0.009 0.080 0.046 0.087 0.077 0.183 (14C =control, background location) COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 03 11/03/15 -0.027 0.051 0.022 0.130 0.030 0.058 0.144 0.099 0.019 0.061 0.028 0.442 04 11/03/15 -0.042 0.084 -0.325 0.195 0.048 0.107 -0.074 0.211 0.030 0.112 -0.112 0.711 14C 11/03/15 -0.061 0.076 -0.096 0.215 0.111 0.096 -0.030 0.164 -0.024 0.096 -0.042 0.708 COLLECTION LOCATION DATE Sb-125 .cs-134 Cs-137 Ce-141 Ce-144 Ac-228 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 03 11/03/15 0.030 0.130 -0.023 0.057 0.167 0.080 0.001 0.116 -0.551 0.388 1.076 0.370 Note 04 11/03/15 0.127 0.172 -0.029 0.092 0.517 0.155 0.072 0.167 -0.464 0.544 0.720 0.832 14C 11/03/15 .0.140 0.248 -0.073 0.096 0.338 0.185 -0.121 0.178 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

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station . 2015 TABLE 6 COW MILK (pCi/I) COLLECTION Cs-134 Cs-137 Ba-140 La-140 LOCATION

   -----------     DATE
               *-----------*         1-131           Sr-89         Sr-90            K-40
                             *----------Fi-r--* --------(+i-)" --------f+t=i* *---------r;-,:j--  -----------,+!~)----- -----------T+tT    ___ *-----------,+i-r---- *-----------f+r-r---

22 01/21/15 -0.132 0.083 1226 120 0.711 3.973 2.946 3.538 -10.800 15.650 1.426 5.418 02/18/15 -0.211 0.148 1295 205 -6.748 6.098 4.754 6.112 21.580 29.690 -2.854 9.028 03/11/15 0.133 0.223 4.9 2.7 0.7 1.3 1352 178 2.921 4.703 -2.471 4.336 -3.004 24.780 2.192 5.964 04/15/15 -0.526 0.347 1203 112 0.668 2.987 1.238 2.898 -1.231 14.630 2.791 5.011 05/13/15 -0.208 0.322 1249 186 5.351 7.164 2.682 6.240 28.800 28.500 6.665 9.012 05/27/15 -0.441 0.206 1224 170 -0.256 4.364 3.123 4.349 3.913 22.070 -0.041 4.513 06/10/15 -0.171 0.345 1254 192 0.177 4.933 1.279 5.281 -7.014 24.410 4.429 6.763 06/22/15 -0.303 0.199 3.1 4.0 0.0 0.9 1186 185 -5.860 5.091 0.312 5.231 -5.341 21.110 -0.136 6.032 07/08/15 0.006 0.211 1360 148 -1.967 3.710 -0.162 3.364 11.170 15.530 -0.486 3.898 07/23/15 -0.179 0.139 1212 153 -2.154 5.144 2.243 4.211 1.566 20.320 1.918 6.529 08/12/15 -0.119 0.190 1217 188 -3.266 6.888 -0.891 7.155 -10.020 29.930 -2.299 7.536 08/26/15 . -0.571 0.499 1373 237 -1.491 6.586 -0.996 5.847 -8.&77 28.100 4.742 9.184 09/16/15 -0.298 0.349 1379 250 -10.330 6.599 0.381 6.839 -1.172 31.820 0.275 7.201 09/28/15 -0.157 0.458 7.4 5.9 0.5 0.4 1102 174 -3.461 4.465 0.011 4.768 -2.659 23.600 5.516 8.152 10/13/15 -0.069 0.196 1314 214 4.950 5.419 -1.614 5.318 8.551 22.390 -1.510 6.276 10/27/15 -0.638 0.224 1251 201 -3.238 4.829 0.986 5.200 -3.325 23.210 3.736 5.861 11/18/15 0.092 0.415 1211 213 -3.238 7.696 0.168 7.672 20.710 24.980 4.292 7.229 12/08/15 -0.220 0.248 4.7 3.2 0.7 0.7 1284 127 -0.693 2.780 -0.967 3.165 11.850 12.990 -2.151 4.244 3-14

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 7 WELL WATER (pCi/I} COLLECTION Mn-54 Co-58 Fe-59 Co-60 LOCATION DATE H-3

                          ---------F-i-Y-Be-7
                                          ---------r+i-r-         K-40                  Cr-51
                                                           *---------Ft:;--* ---------F-i-Y- ---------Fr* *---------(+7:y-* *--------F-ir ---------r+i-r*

71 06/23/15 246 513 -31.2 32.7 -44.3 53.8 -39.3 32.5 3.9 3.3 -0.5 4.3 0.5 8.2 -1.1 3.3 09/22/15 -184 502 22.9 33.1 37.8 41.3 -9.7 35.3 -2.2 4.0 -3.4 3.4 1.3 6.5 -0.8 3.7 12/10/15 -83 556 13.0 28.6 54.7 47.1 -36.7 31.3 0.2 2.7 0.3 3.3 0.0 6.2 0.9 2.5 72 06/22/15 534 523 -7.9 29.4 6.4 38.7 -14.8 33.1 -1.8 3.4 -1.1 3.4 -4.7 7.8 2.5 4.1 09/21/15 13 518 23.8 42.0 -7.3 67.5 6.0 52.3 -1.6 5.0 -0.1 4.7 3.0 9.9 1.4 4.2 12/09/15 476 595 19.1 23.9 11.6 49.9 -2.8 28.2 -2.6 2.7 0.9 2.6 -2.3 6.8 2.2 2.7 76 06/18/15 83 491 12.8 31.4 -8.25 49.48 -49.3 36.5 -0.8 3.48 -0.46 3.68 1.12 6.33 -0.57 3.47 09/15/15 368 593 -30.9 48.6 48.2 104.6 39.6 49.5 -3.3 6.2 0.0 6.0 -5.3 12.8 -4.5 6.2 12/07/15 -586 590 -20.6 44.3 -5.1 80.9 2.1 53.8 -5.0 6.9 -0.8 5.4 12.2 9.6 1.1 5.8 77 06/18/15 573 530 -17.2 33.2 -5.7 53.8 5.3 37.3 1.1 4.4 0.9 4.0 -3.9 6.8 0.8 4.1 09/15/15 165 579 -46.0 41.1 29.2 71.4 0.3 53.8 4.0 4.9 -0.2 5.0 0.9 9.9 3.0 4.3 12/07/15 45 565 16.6 48.8 56.9 92.3 29.9 50.2 -6.4 6.0 -6.5 6.8 1.2 11.1 -4.6 5.8 78 06/18/15 438 514 1.38 27.2 127 61.56 -10.5 32.1 -0.23 2.94 2.23 3.31 4.05 5.11 -0.02 2.79 09/15/15 -32 563 7.0 34.8 48.6 82.0 -10.5 36.6 -0.1 4.6 -3.6 4.1 -0.1 9.2 -4.7 5.4 12/07/15 488 740 -33.2 54.3 -10.0 78.7 -40.5 53.4 -6.2 6.6 2.0 5.8 -2.3 12.0 3.7 5.3 79 06/22/15 523 529 -2.2 34.4 34.9 70.2 -2.2 33.9 -0.6 3.4 -0.4 3.7 1.4 7.4 3.0 4.1 09/21/15 438 551 -15.2 35.1 -29.7 60.0 -31.7 42.5 -1.8 3.5 -1.0 4.2 5.6 8.0 2.6 3.6 12/09/15 548 602 -11.6 24.9 12.6 35.8 11.5 32.7 -1.0 2.2 -2.3 2.4 -0.2 3.8 -0.7 1.5 81 06/22/15 749 546 4.4 34.8 -33.9 65.2 -11.4 40.0 -1.2 3.2 -0.4 4.3 2.9 7.3 -1.0 4.5 09/21/15 89 524 10.2 46.9 64.6 82.4 23.8 55.1 0.2 4.7 0.6 5.3 4.4 9.0 2.4 4.0 12/10/15 388 591 -6.5 23.7 18.9 52.5 -29.0 29.9 0.7 2.7 -1.3 2.6 -2.6 5.1 -0.2 2.8 82 06/22/15 677 540 -33.7 38.9 4.6 75.8 25.1 44.5 -4.5 4.3 -3.2 4.3 2.7 7.8 0.3 3.6 09/22/15 -419 481 -54.7 47.5 21.1 72.1 28.4 52.0 -3.3 6.2 1.6 6.9 -2.7 11.3 -0.2 6.7 12/10/15 216 577 20.4 25.1 93.2 41.7 3.6 30.1 -1.3 2.5 -2.5 3.0 -1.1 6.0 2.7 2.8 83 06/22/15 544 528 17.0 35.2 -9.0 65.3 2.9 44.2 -1.3 3.7 -0.3 3.4 2.2 6.9 -2.7 4.3 09/21/15 -362 486 46.1 44.0 -78.0 65.8 -20.8 40.2 -5.4 4.8 0.4 4.7 3.0 9.8 3.9 4.9 12/10/15 13 561 -0.5 25.0 90.6 55.8 -0.1 29.7 0.0 2.7 -3.5 2.6 4.8 5.3 1.2 2.3 3-15

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 7 WELL WATER (pCi/I) COLLECTION

*------------* ---------Fi-r LOCATION DATE Zn-65 Nb-95

                                                  ---------Fi-T-Zr-95
                                                                           *---------(i-i:y--

Ru-103

                                                                                                   ---------r+i-r*            Ru-106
                                                                                                                        *--------T+tT.

Sb-125

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

1-131

                                                                                                                                                                ---------r+i-r-       Cs-134
                                                                                                                                                                                *---------c-tt:r*

71 06/23/15 1.9 4.9 -4.5 4.1 0.4 6.7 -4.5 4.5 14.6 41.4 -4.3 11.0 2.9 6.5 -3.3 4.7 09/22/15 5.6 8.7 4.2 4.4 3.7 6.4 -3.8 4.2 -0.5 34.7 -0.7 10.7 -5.0 5.4 0.3 3.9 12/10/15 2.4 6.1 3.7 3.1 -2.7 4.8 -3.3 3.7 2.8 27.9 -4.7 8.3 6.2 8.6 -1.2 3.2 72 06/22/15 -0.4 8.6 -3.0 3.7 -3.6 5.2 1.3 3.4 2.0 34.0 -7.1 10.1 -0.2 5.9 1.9 3.0 09/21/15 -1.8 11.5 1.0 4.9 -3.9 8.1 -4.2 5.8 -26.2 49.3 0.5 13.4 6.4 7.6 -4.7 5.8 12/09/15 -2.1 4.8 0.5 2.9 1.5 4.3 -4.5 3.0 -1.4 20.5 -4.4 7.0 3.9 8.0 0.1 3.5 76 06/18/15 -1.5 7.9 -0.7 4.0 -1.4 6.7 1.3 4.2 15.5 34.5 6.0 10.6 -1.3 6.3 -1.2 3.7 09/15/15 4.5 13.1 1.6 6.0 2.5 10.2 0.0 5.4 -7.1 43.0 -9.3 13.9 -0.9 8.1 2.3 5.0 12/07/15 9.2 15.2 4.1 5.8 1.0 8.3 -3.3 6.6 -24.2 56.7 -9.5 17.6 0.2 7.4 -0.8 7.0 77 06/18/15 -0.6 8.9 -1.8 5.0 -0.5 6.4 -0.1 4.1 -10.1 35.9 -11.8 10.3 -1.3 7.1 -1.3 4.3 09/15/15 5.1 10.4 4.9 5.8 5.8 8.6 -4.3 6.2 -3.3 45.0 -5.8 13.9 -3.5 8.6 -1.0 5.8 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 -10.8 18.2 -5.3 7.3 -1.6 6.4 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 -12.4 9.3 2.9 5.9 2.5 5.4 09/15/15 -16.2 12.8 3.5 4.6 1.2 8.7 3.1 4.4 -28.8 41.0 4.5 11.6 0.2 7.1 -1.2 4.8 12/07/15 -9.5 18.1 4.6 5.8 -0.9 9.7 2.3 6.6 8.5 55.9 0.7 15.4 -5.9 7.8 4.7 5.9 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 4.1 ' 9.9 3.2 6.7 2.3 3.6 09/21/15 -17.1 11.7 4.0 4.9 -0.8 7.4 1.0 4.5 -10.1 44.2 -8.5 13.9 1.4 6.3 3.9 5.0 12/09/15 -6.4 4.5 0.5 2.3 -2.5 4.3 4.2 3.2 -6.9 22.1 -1.8 7.4 2.0 9.7 -0.6 3.0 81 06/22/15 2.6 8.5 0.8 4.0 -3.8 6.4 -0.1 4.6 4.4 35.4 0.1 11.3 0.6 6.6 -0.1 4.1 09/21/15 8.5 10.9 6.4 5.8 -4.3 8.3 -1.8 6.2 -11.6 42.3 2.9 14.5 -3.5 8.2 3.1 5.7 12/10/15 2.7 5.6 2.7 2.7 -0.9 4.7 0.7 3.1 -12.5 23.9 2.5 7.4 3.6 7.5 0.3 2.9 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 -1.5 12.7 3.0 7.8 1.6 4.5 09/22/15 -0.1 15.9 7.7 7.2 -3.8 10.2 -2.3 5.9 -1.9 50.5 -3.4 17.2 7.2 7.9 1.0 6.5 12/10/15 0.0 6.3 6.9 3.7 Note3 -2.2 5.2 -3.7 3.2 3.2 22.1 -0.4 7.3 2.8 7.9 0.3 2.7 83 06/22/15 -6.3 8.7 4.3 4.5 -1.1 7.3 -2.0 4.6 15.1 35.4 -5.6 11.6 -3.9 7.9 2.4 4.7 09/21/15 2.7 12.4 6.7 6.3 0.5 8.3 -0.8 5.1 -23.7 42.0 -2.0 13.8 0.3 6.6 0.1 5.6 12/10/15 -4.0 5.4 1.5 2.7 -1.5 5.0 -1.4 3.2 16.6 22.4 4.1 6.9 4.3 7.9 0.9 2.8 Note 3: Extra counts detected in the Nb-95 peak area but there was no peak for positive identification of Nb-95. 3-16

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 7 WELL WATER (pCi/I) COLLECTION Cs-137 Ba-140 La-140 Ac-228 LOCATION DATE

                                                      ---------Fi~--     ---------Fr.r-  ---------,+r.r-* *--------(+i=-i-*

71 06/23/15 -0.5 4.1 4.6 16.5 -3.7 7.0 1.9 14.6 09/22/15 -0.9 4.2 6.1 15.8 -0.2 4.8 8.2 14.7 12/10/15 2.8 2.9 16.1 20.1 5.3 6.4 6.0 11.2 72 06/22/15 -1.5 3.6 -18.2 16.3 3.1 5.7 0.0 14.8 09/21/15 -4.8 5.4 -1.3 23.3 3.2 8.1 13.6 19.2 12/09/15 0.4 2.9 -0.5 16.8 -0.5 . 6.0 13.2 10.2 76 06/18/15 -0.4 3.7 -4.5 17.0 -1.1 5.5 -9.2 14.2 09/15/15 -6.0 6.4 -25.5 26.0 0.6 8.4 11.7 21.5 12/07/15 -0.3 6.9 8.4 26.0 -1.1 4.4 -7.1 21.2 77 06/18/15 -1.4 4.1 -7.8 18.2 1.7 5.9 11.1 13.5 09/15/15 -3.0 5.6 0.2 26.5 -4.0 7.0 12.2 19.2 12/07/15 2.3 7.3 0.0 24.9 1.6 8.6 22.0 23.8 78 06/18/15 0.2 3.2 -4.9 16.0 -2.6 4.4 10.9 11.2 09/15/15 3.1 5.1 -3.7 19.5 -6.0 7.5 1.8 15.3 12/07/15 0.8 6.3 1.3 26.1 2.9 7.7 -11.4 19.7 79 06/22/15 3.0 3.9 4.5 18.9 2.2 6.5 7.8 14.2 09/21/15 -2.5 4.3 0.4 19.6 3.2 5.1 5.6 16.7 12/09/15 1.3 2.4 -1.0 17.5 0.6 3.4 -10.8 8.5 81 06/22/15 0.9 4.2 7.1 18.7 -1.7 6.9 -2.1 14.3 09/21/15 -4.2 6.3 25.7 23.6 9.3 6.3 '1.0 19.3 12/10/15 -0.7 2.6 0.3 17.4 4.3 5.1 -1.8 9.5 82 06/22/15 0.3 4.7 -17.5 20.2 -0.8 6.2 4.2 15.4 09/22/15 -1.5 5.9 3.1 22.1 -0.8 8.1 -15.4 24.2 12/10/15 -2.8 2.9 1.1 18.3 4.7 6.6 -2.6 10.0 83 06/22/15 -4.6 4.7 11.5 21.1 5.6 7.4 -4.4 15.2 09/21/15 -1.0 4.7 -15.9 19.5 -1.3 6.6 2.9 18.4 12/10/15 0.1 2.6 0.2 19.1 -2.7 4.6 3.3 9.9 3-17

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 8 FRUITS & VEGETABLES (pCi/g wet wt.) LOCATION 25 (fruit are extra samples not required by the REMODCM) COLLECTION

              ,____ J.Y.£!:____ _

DATE Be-7 (+/-) K-40 (+/-) Cr-51 (+/-) Mn-54 (+I-) Co-58 (+/-) Fe-59 (+/-) Co-60 (+/-) 07/27/15 Greens 0.025 0.097 1.954 0.355 0.021 0.109 0.009 0.011 -0.009 0.012 -0.008 0.027 -0.007 0.010 07/27/15 Blueberries 0.046 0.092 0.809 0.251 0.040 0.107 -0.003 0.009 -0.004 0.010 0.010 0.022 0.003 0.009 08/10/15 Tomatoes 0.009 0.072 2.069 . 0.280 -0.037 0.082 0.006 0.008 0.002 0.009 0.018 0.020 -0.002 0.009 10/20/15 Eggplant 0.024* 0.063 2.048* *0.256 0.034 0.069 0.002 0.007 -0.003 0.009 -0.014 0.019 -0.006 0.009 10/20/15 Apples -0.005 0.062 1.265 0.226 0.035 0.069 0.004 0.007 -0.006 0.007 -0.005 0.014 0.006 0.008 COLLECTION

              ,____ J.Y.£!: ____ _        Zn-65                                          Zr-95                          Ru-103             Ru-106             Sb-125              1-131 DATE

(+/-) -----------------* Nb-95 (+/-) -----------(+i:;--- *----------------- (+/-) *----------r+i.r-- ----------Fi-r--* ----------(~i~---* 07/27/15 Greens -0.029 0.029 0.004 0.012 -0.006 0.019 -0.007 0.013 0.086 0.090 0.003 0.029 0.011 0.034 07/27/15 Blueberries -0.013 0.022 -0.007 0.011 -0.001 0.019 -0.003 0.011 -0.047 0.084 -0.024 0.027 0.009 0.034 08/10/15 Tomatoes -0.021 0.022 0.008 0.010 0.003 0.016 -0.003 0.009 -0.053 0.080 0.013 0.023 0.011 0.018 10/20/15 Eggplant 0.002 O.D18 0.006 0.008 0.006 0.013 -0.004 0.007 -0.036 0.075 -0.007 0.022 0.015 0.012 10/20/15 Apples -0.004 0.016 0.003 0.007 0.008 0.012 -0.003 0.007 -0.007 0.059 -0.007 0.01 ~ -0.001 0.012 COLLECTION _____ J.Y.£!:____ _ DATE Cs-134 (+/-) Cs-137 (+/-) Ba-140 (+/-) La-140 (+/-) Ce-141 (+I-) Ce-144 (+/-) Ac-228 (+/-) 07/27/15 Greens -0.002 0.013 -0.004 0.011 -0.014 0.075 0.031 0.025 0.017 0.020 -0.010 0.066 0.012 0.036 07/27/15 Blueberries -0.019 0.011 -0.003 0.009 -0.035 0.066 -0.011 0.023 -0.023 0.018 0.002 0.058 0.007 0.041 08/10/15 Tomatoes -0.009 0.009 0.003 0.008 0.002 0.047 -0.003 0.015 0.002 0.014 -0.043 0.058 0.009 0.034 10/20/15 Eggplant -0.014 0.008 0.002 0.007 0.003 0.035 -0.011 0.009 -0.002 0.012 0.002 0.049 -0.004 0.030 10/20/15 Apples -0.017 0.008 0.003 0.008 0.030 0.032 0.002 0.010 0.001 0.012 0.008 0.046 -0.007 0.027 3-18

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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 (+/-) Fe-59 (+/-) Co-60 (+/-) 07/27/15 Greens 0.009 0.100 2.168 0.314 -0.036 0.113 0.003 0.011 -0.006 0.011 -0.022 0.027 -0.002 0.009 07/27/15 Blueberries 0.043 0.056 0.803 0.174 0.021 0.078 0.001 0.006 0.006 0.006 -0.005 0.015 -0.001 0.007 10/20/15 Eggplant 0.020 0.071 3.199 0.370 CJ.001 0.073 0.006 0.008 0.001 0.008 0.000 0.016 -0.005 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 -0.003 0.021 0.002 0.007 COLLECTION Ru-103 Sb-125 1-131 DATE _____ ])~~~----- Zn-65 (+/-) Nb-95 (+/-) Zr-95 (+/-) (+/-) 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 0.012 0.028 -0.003 0.034 07/27/15 Blueberries -0.018 0.017 0.005 . 0.007 0.010 0.014 -0.002 0.008 0.027 0.060 -0.014 0.020 0.000 0.023 10/20/15 Eggplant -0.002 0.020 0.003* 0.008 0.000 0.015 0.002 0.008 -0.032 0.073 0.004 0.021 -0.007 O.o15 10/20/15 Apples -0.006 0.023 0.003 0.010 0.005 0.017 -0.006 0.011 0.014 0.088 0.006 0.027 -0.012 0.018 COLLECTION DATE ,____ }YE~----- Cs-134 (+/-) Cs-137 (+/-) Ba-140 (+/-) La-140 (+/-) Ce-141 (+/-) Ce-144 (+/-) Ac-228 (+/-) 07/27/15 Greens -0.001 0.012 -0.002 0.011 -0.021 0.071 0.022 0.022 0.015 0.021 -0.039 0.076 -0.001 0.037 07/27/15 Blueberries -0.009 0.007 -0.002 0.006 0.013 0.049 -0.014 0.016 -0.005 0.011 -0.031 0.039 0.015 0.028 10/20/15 Eggplant -0.005 0.008 -0.002 0.009 0.020 0.036 0.007 0.012 0.001 0.015 0.023 0.056 -0.005 0.032 10/20/15 Apples -0.002 0.011 0.004 0.010 0.047 0.044 0.000 0.013 0.016 0.015 0.067 0.062 0.027 0.042 3-19

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 9 BROADLEAF VEGETATION (pCi/g wet wt.) LOCATION 1 COLLECTION DATE Be-7

                    *-------T+i-r--             K-40                 Cr-51                  Mn-54
                                         ----------Fi-r-* ----------Fi:,---* -----------(+i:;--*

Co-58

                                                                                                         *----------Fi:r--   *----------r+i-i Fe-59

___ *----------z.i7-r-Co*60 07/16/15 0.808 0.207 4.064 0.410 -0.019 0.126 -0.004 0.012 -0.003 0.011 0.019 0.026 o.01 o 0.012 10/06/15 0.959 0.311 4.127 0.698 -0.153 0.211 0.021 0.020 -0.005 0.024 -0.004 0.047 0.000 0.022 COLLECTION DATE

                    *----------r+i-i Zn-65

___ ----------z.i7-r--* Nb-95 Zr-95

                                                              ----------(+i:,---*          Ru-103
                                                                                     --------**1+i=r-*

Ru-106

                                                                                                         -----------cn:r--         Sb-125
                                                                                                                             *----------r+,:r--            1-131
                                                                                                                                                  *----------z.i7-r--*

07/16/15 -0.026 0.031 -0.003 0.013 -0.021 0.022 0.000 0.014 0.004 0.108 0.006 0.033 0.027 0.032 10/06/15 0.001 0.059 0.019 0.025 0.015 0.036 -0.008 0.023 -0.005 0.217 0.063 0.069 -0.031 0.039 COLLECTION DATE

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

Cs-134 Cs-137

                                         ----------Fi-r--*          Ba-140
                                                              ----------(+i:,---*          La-140
                                                                                     ----------(+i=r-*

Ce-141

                                                                                                         *----------c+t:r--           Ce-144
                                                                                                                             *----------r+,:r--          Ac-228
                                                                                                                                                  *----------r+i-r--

07/16/15 0.002 0.011 0.010 0.013 -0.031 0.077 0.003 0.019 0.025 0.022 -0.055 0.072 0.057 0.050 10/06/15 0.014 0.026 0.010 0.024 0.056 0.115 -0.019 0.028 -0.018 0.039 -0.018 0.174 0.145 0.134 LOCATION 10 COLLECTION DATE Be-7 K-40 Cr-51 Mn-54 Fe-59

                    *----------r+i-r--   ----------Fi-r--*    ----------(+i=i---*    -----------(+i:;--* *----------r+i:r--

Co-58

                                                                                                                             *----------Fi-r--            Co-60
                                                                                                                                                  *----------Fi-)   __ _

07/16/15 o.485 o.183 3.584 0.374 -0.009 0.115 0.015 0.011 -0.008 0.011 -0.006 0.024 -0.004 0.009 10/06/15 0.634 0.449 7.607 1.042 -0.165 0.194 0.002 0.018 -0.011 0.017 0.011 0.045 0.001 0.016 COLLECTION DATE Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 Sb-125 1-131

                    *----------r+i-r--   ----------Fi-r--*    ----------Fi:,---*     ----------(+i=r--   *----------cn:r--   *----------r+,:r--   *----------r+i-r--

07/16/15 -0.045 0.027 -0.005 0.012 -0.005 0.020 0.001 0.013 -0.016 0.101 0.006 0.031 0.016 0.032 10/06/15 0.011 0.047 -0.007 0.020 -0.011 0.039 0.007 0.020 0.005 0.181 -0.044 0.057 -0.003 0.035 COLLECTION DATE Cs-134 Cs-137 Ba-140 La-140 Ce-141 Ce-144 Ac-228

                    *----------r+i:r--   ----------Fi-r--*    ----------Fi:,---*     ----------(+i=r--   *----------cn:r--   *----------r+i-r--   *----------F-r--

07/16/15 0.000 0.012 0.008 0.012 0.043 0.077 0.007 0.016 -0.015 0.022 0.028 0.082 0.107 0.051 10/06/15 -0.001 0.022 0.004 0.019 -0.046 0.080 -0.002 0.021 0.022 0.038 -0.010 0.146 -0.020 0.080 3-20

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 9 BROADLEAF VEGETATION (pCi/g wet wt.) LOCATION 17 COLLECTION DATE Be-7 K-40

                     *--------Fr.r*-   ----------Fi-r--*           Cr-51
                                                            ----------Fi:,---*

Mn-54

                                                                                   ----------Ti*rr**          Co-58
                                                                                                       *----------(+t:r--  *----------,+,:r--

Fe-59 Co-60

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

07/16/15 0.604 0.258 2.840 0.398 -0.055 0.140 -0.002 0.013 -0.009 0.014 0.000 0.029 0.009 0.012 10/06/15 0.826 0.288 3.430 0.699 -0.068 0.196 -0.011 0.017 -0.005 0.015 0.034 0.048 -0.006 0.024 COLLECTION DATE Zn-65 Nb-95

                    *----------r+r.r*- ----------z.i7-r--*         Zr-95
                                                            ----------(+iT-*

Ru-103

                                                                                   ----------,+ri*--          Ru-106
                                                                                                       *----------(+t:r--         Sb-125              1-131
                                                                                                                           *----------[+1:r*- *----------(+i-r--

07/16/15 -0.048 0.031 0.006 0.013 -0.002 0.023 -0.007 0.013 -0.027 0.111 0.008 0.037 -0.017 0.038 10/06/15 0.022 0.040 0.000 0.021 0.000 0.033 0.010 0.020 0.026 0.143 -0.059 0.052 0.008 0.034 COLLECTION DATE Cs-134 Cs-137

                    *----------r+r.r*- ----------Fi-r--*          Ba-140
                                                            ----------(+i:,---*

La-140

                                                                                   -----------(+7y---

Ce-141

                                                                                                       *----------(+t:r--  *----------r+q*--

Ce-144 Ac-228

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

07/16/15 -0.008 0.016 0.013 0.013 -0:042 0.083 -0.008 0.023 0.010 0.023 -0.047 0.086 0.026 0.049 10/06/15 -0.007 0.022 0.003 0.020 -0.052 0.096 0.009 0.033 -0.013 0.033 -0.074 0.130 0.063 0.076 LOCATION 26 (control, background location) COLLECTION DATE Be-7 K-40 Cr-51 Mn-54

                    *----------r+r.r*- ----------(-i7-r--*  ----------(+i:,---*    -----------(+i=r--*        Co-58
                                                                                                       *---------T+i=;---  *----------r;r.r--

Fe-59 Co-60

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

07/16/15 1.021 0.193 3.805 0.372 -0.004 0.100 -0.009 0.010 0.007 0.010 0.011 0.023 0.004 0.011 10/06/15 1.042 0.290 3.261 0.598 0.061 0.177 -0.001 0.018 -0.008 0.016 -0.020 0.040 0.010 0.019 COLLECTION DATE

                    *----------wr--

Zn-65 Nb-95

                                       ----------Fi-r--*           Zr-95
                                                            ----------FiT-*              Ru-103
                                                                                   ----------,+i=r*--         Ru-106
                                                                                                       *----------(+t=r--         Sb-125
                                                                                                                           *----------r+1:r*-         1-131
                                                                                                                                              *----------z.;r.r*-

07/16/15 -0.025 0.026 -0.007 0.010 -0.003 0.017 0.008 0.011 -0.033 0.087 0.013 0.027 0.001 0.028 10/06/15 -0.040 0.038 0.006 0.019 0.002 0.035 0.000 0.019 -0.053 0.157 0.023 0.046 -0.025 0.033 COLLECTION DATE Cs-134 Cs-137 Ba-140 La-140

                    *----------r+r.r*- ----------Fi-r--*    ----------Fi:,---*     -----------(+i=-r-*        Ce-141
                                                                                                       *----------Ft:r--             Ce-144
                                                                                                                           *----------r+rr*--        Ac-228
                                                                                                                                              *----------r+r.r*-

07/16/15 -0.010 0.011 0.009 0.010 0.020 0.061 0.005 0.017 -0.016 0.019 0.015 0.063 0.022 0.040 10/06/15 -0.032 0.022 0.021 0.020 -0.019 0.085 -0.007 0.026 0.008 0.032 0.009 0.127 0.007 0.093 3-21

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 10 SEAWATER (pCi/I) LOCATION 32 COLLECTION

         **.. !?~!~----*                      H-3                    Be-7
                                    ----------**r+r.r**-- *-----------(+ri*---                K-40
                                                                                   ----------**r+,:;-**-*                    Cr-51
                                                                                                                 *-----------(+i~-----

Mn-54

                                                                                                                                        ----------**r+,:;*---*                Co-58                     Fe-59
                                                                                                                                                                   ------------(+i-i""""" *----------*-c+i:;**--*

01/26/15 375 135 -7 .2 22.1 245 67 -18.0 23.7 0.4 2.3 0.4 2.7 2.5 5.4 02/24/15 92 117 8.5 32.3 329 92 -5.1 31.9 -0.9 4.4 -3.1 3.9 5.8 9.5 03/31/15 319 134 5.0 15.1 277 46 8.0 21.1 0.1 1.7 -1.0 1.8 -0.8 4.0 04/28115 176 121 0.5 29.3 448 225 28.1 32.5 0.2 3.3 -1.4 3.5 0.6 6.8 05/26/15 645 154 23.8 36.8 181 123 -18.6 42.6 1.5 4.4 -2.9 4.2 -1.4 8.5 06130/15 622 156 17.3 29.8 273 79 4.4 31.0 -0.5 3.2 -0.5 3.2 -3.6 6.3 07128115 437 188 -0.9 26.8 311 77 18.2 27.9 -1.5 3.0 -3.0 3.5 -1.7 6.4 08/25115 546 136 -7.1 32.2 273 93 5.7 33.6 -0.1 3.2 1.6 3.9 -0.9 9.2 09/29/15 433 243 0.6 39:6 308 110 -7.6 41.4 1.5 4.8 -2.5 5.1 -2.6 11.0 10/27115 1190 323 -28.5 42.0 238 115 -10.6 46.5 -0.2 4.8 1.2 4.9 3.0 9.1 11/24115 205 123 -1.1 26.1 371 102 -30.1 31.0 1.7 2.8 -3.8 3.7 -4.9 6.8 12/29/15 157 125 11.4 39.8 411 110 -1.1 45.5 -5.2 4.1 -1.2 4.4 -1.3 10.3 COLLECTION Zn-65 Nb-95 Zr-95

         .**.!?~!~----*                     Co-60
                                    ----------**r+r.r**-- *-----------Fi      ____ ----------**r.;,:j*---*       *-----------(+i~-----

Ru-103

                                                                                                                                        ----------**r+,:;**--*               Ru-106                    Sb-125
                                                                                                                                                                   ------------(+i-i""""" *-----------*c+i:;**--*

01126/15 -1.4 3.2 -5.8 5.6 0.9 2.5 2.4 4.7 -1.0 2.8 0.0 23.8 -1.8 6.8 02/24115 1.4 4.2 -3.7 10.4 -0.1 4.6 -2.6 7.3 1.8 4.3 -12:7 38.6 -3.3 9.6 03131115 -0.5 1.6 -5.1 3.5 -0.3 1.7 3.0 3.4 -0.9 2.4 -7.1 14.2 0.3 4.7 04/28115 -1.1 3.7 2.6 7.0 5.7 3.7 Note -4.5 6.2 1.9 3.6 19.0 31.5 4.0 9.3 05126/15 0.6 3.9 0.9 8.2 -1.0 4.7 -4.6 7.2 -2.2 5.1 -2.9 38.3 -3.9 11.8 06130/15 1.7 3.2 0.1 7.7 0.5 3.4 -0.8 6.0 3.8 3.8 10.7 28.4 4.2 8.6 07/28/15 -2.3 3.3 8.0 8.3 17.2 4.2 Note 1.5 5.2 1.1 3.2 -0.3 25.3 5.0 8.7 08125115 -0.1 4.2 -11.3 9.8 -0.6 3.8 3.8 7.6 -0.3 3.7 -7.6 33.9 -1.6 11.4 09/29115 0.1 4.1 -9.4 10.9 1.9 3.5 0.3 7.5 -0.2 5.2 -20.6 44.2 -11.5 13.5 10127/15 4.0 4.9 -10.5 12.5 -3.8 4.8 -2.1 8.1 1.4 4.8 10.2 40.7 4.8 13.3 11124/15 3.5 3.3 4.6 8.4 -1.3 3.4 -2.1 5.1 -0.9 3.8 -0.2 35.9 11.0 10.1 12129/15 3.2 3.9 -0.8 9.9 3.1 4.5 1.6 8.3 -0.6 4.8 9.6 43.4 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. COLLECTION

         ---   DATE
             .................... .          1-131
                                    ----------**r+r.r**--          Cs-134
                                                          *-----------(+i~i""""

Cs-137

                                                                                   ----------**r+,:i*---*                   Ba-140
                                                                                                                 *-----------(+i~-----

La-140

                                                                                                                                        ----------**c-:;,:;*---*             Ac-228
                                                                                                                                                                   ------------Fi-i"    ___ _

01/26115 -2.8 4.6 -1.1 2.6 -0.9 2.8 -7.1 12.0 3.1 3.9 -4.3 9.7 02124115 5.8 6.6 -4.8 3.7 -0.6 3.8 3.0 20.1 2.3 7.6 -5.0 15.9 03/31/15 4.7 8.3 -0.1 1.7 0.1 1.6 -8.5 14.3 -1.9 4.3 -2.8 6.5 04/28115 4.5 6.9 0.0 3.4 *o.7 3.9 13.2 19.9 -2.3 4.8 -79.5 30.5 05126115 -0.6 8.3 -5.4 4.4 0.9 4.7 3.6 23.0 2.0 5.2 2.9 15.7 06130/15 2.5 7.1 1.4 3.5 0.5 3.5 -20.1 19.5 1.6 5.9 4.0 12.2 07/28115 0.2 5.7 3.7 3.4 0.1 3.6 -0.9 16.0 4.8 5.2 1.6 12.4 08125/15 -1.3 6.1 -1.3 4.3 3.0 3.8 2.5 14.7 0.1 5.1 -13.5 14.4 09129115 0.9 7.9 -4.4 5.2 0.7 4.6 3.0 22.1 2.5 6.4 0.1 14.9 10127/15 -2.7 7.2 0.3 4.7 -0.1 4.7 -4.3 19.5 3.2 7.4 10.3 17.4 11124/15 -0.9 5.4 -2.0 3.7 -3.0 3.6 5.7 16.6 2.0 5.7 10.7 12.3 12129/15 -0.1 7.9 -4.6 4.6 -2.8 5.0 20.6 22.6 1.6 7.3 -2.2 16.3 3-22

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 10 SEAWATER (pCi/I) LOCATION 37 (control, background location) COLLECTION DATE H-3 (+/-) Be-7

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

K-40

                                                                   ------------[+1:)----*                 Cr-51
                                                                                                *-----------(+i:,----- --------------------*

Mn-54 (+/-) Co-58

                                                                                                                                               *-----------(:;:i_r----            Fe-59
                                                                                                                                                                         *-----------T+i:;----*

03/16/15 -62 107 4.7 30.1 203 98 30.95 35.23 0.5 3.5 -2.6 3.3 2.3 8.4 06/09/15 45 118 1.8 27.5 314 80 -3.13 31.22 -0.8 2.9 1.1 3.0 0.2 6.1 09/15/15 54 159 -2.6 40.5 242 120 27.20 46.87 0.0 4.5 0.9 4.7 6.0 8.2 12/08/15 91 118 11.3 46.2 370 118 38.93 47.98 1.1 5.6 -2.5 5.2 -5.9 9.4 COLLECTION DATE Co-60 Zn-65

              *------------r;i-r---* *-----------(+i:,-----        ------------(+,:)

Nb-95 _____ Zr-95

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

Ru-103 (+/-) Ru-106

                                                                                                                                               *-----------(:;:i_r----           Sb-125
                                                                                                                                                                         *-----------T+i:;----*

03/16/15 1.3 3.6 -8.5 7.6 -1.4 3.8 2.9 6.7 -4.3 4.5 17.2 32.5 -5.9 10.2 06/09/15 2.7 3.1 0.1 6.8 -0.6 3.2 -3.5 5.6 -2.4 3.6 -20.0 27.0 -1.3 7.6 09/15/15 1.1 4.9 -12.6 10.3 1.3 5.0 1.0 8.5 -1.8 5.1 -6.3 39.6 -7.3 13.4 12/08/15 3.9 4.2 1.7 11.2 2.6 4.5 -2.8 7.7 -0.1 5.0 -25.1 42.1 -6.5 12.7 COLLECTION DATE 1-131 Cs-134 Cs-137 Ba-140 La-140 Ac-228

* ------------(+i-) _____ *-----------(+iT ____ ------------[+1:i----* *-----------(+i:,----- ------------r+1T ____ *-----------(:;:i-i _____

03/16/15 7.3 7.8 -1.0 3.3 2.4 3.6 -2.2 17.9 1.6 6.8 5.8 14.4 06/09/15 -3.3 7.2 -2.6 2.9 -1.1 3.0 3.5 18.3 1.3 5.0 -4.1 11.2 09/15/15 -5.6 8.6 -7.5 5.8 -0.9 5.3 -28.8 20.9 -4.4 6.6 -20.2 19.5 12/08/15 0.1 8.4 -0.7 5.4 0.7 5.5 8.4 22.0 -5.4 10.2 -12.1 19.4 3-23

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
                                                      ----------T+r.r--*                 K-40                     Cr-51                 Mn-54                   Co-58
                                                                                ----------'[+1:;---* ----------..(+1:)*--* -----------(+1:)"'" -----------(+i-)"" ----------T+1:r--*

Fe-59 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
                                                      -----------<'+,:r*.. -----------(-.;:,:;-*--                Nb-95
                                                                                                          -----------{+,:;----           Zr-95
                                                                                                                                 -----------(+,:)"            Ru-103
                                                                                                                                                        -----------F,:r*               Ru-106
                                                                                                                                                                           .. ---------*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
                                                                                                                                 -----------c+,:r*             Cs-137
                                                                                                                                                    .. ----------'(+1:)"             Ac-228
                                                                                                                                                                                -----------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. 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 Be-7 K-40 Cr-51 Mn-54 Co-58 Fe-59 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 29 01/15/15 0.2670 0.1124 6.0720 0.4164 -0.0073 0.0936 -0.0048 0.0098 -0.0088 0.0103 0.0042 0.0250 29 05/12/15 0.1966 0.0612 6.0290 0.2142 0.0115 0.0494 -0.0003 0.0044 0.0006 0.0047 -0.0024 0.0115 29 07/22/15 0.0643 0.0905 6.8460 0.4335 -0.0694 0.1072 -0.0046 0.0093 0.0003 0.0102 0.0038 0.0258 29 10/05/15 0.0667 0.0875 6.0680 0.6264 0.0064 0.1127 0.0010 0.0122 0.0014 0.0123 0.0000 0.0351 32 01/15/15 0.1980 0.1* 178 8.3540 0.3809 -0.0712 0.0793 0.0010 0.0078 -0.0029 0.0079 -0.0020 0.0202 32 05/12/15 0.0234 0.0858 7.1700 0.4172 -0.0224 0.0892 -0.0039 0.0093 0.0056 0.0095 0.0084 0.0215 32 07/22/15 0.0881 0.0621 6.3020 0.3398 -0.0053 0.0705 -0.0033 0.0069 0.0023 0.0075 0.0017 0.0183 32 11/20/15 0.0319 0.1159 9.4520 0.6652 0.0407 0.1118 0.0052 0.0124 0.0024 0.0124 -0.0053 0.0332 35 01/15/15 0.2375 0.1582 7.7990 0.5258 -0.0154 0.0387 0.0005 0.0038 -0.0002 0.0036 -0.0025 0.0112 35 05/12/15 0.1387 0.0832 Note 1 6.5640 0.3650 -0.0562 0.0915 0.0002 0.0087 -0.0082 0.0089 0.0033 0.0215 35 07/22/15 0.0942 0.0954 6.8390 0.3896 -0.0368 0.0912 0.0087 0.0091 -0.0040 0.0101 0.0129 0.0228 35 10/05/15 0.0709 0.1506 7.8080 0.8566 0.0654 0.1500 0.0062 0.0147 -0.0089 0.0178 -0.0002 0.0399 Note 1: Result is less than minimum detectable activity (MDA) of 0.149 pCi/g. 36 01/16/15 0.1634 0.1287 6.1650 0.5130 0.0931 0.1153 -0.0057 0.0129 0.0069 0.0136 -0.0111 0.0338 36 06/12/15 0.0651 0.0896 6.0150 0.4647 -0.0282 0.0964 0.0033 0.0100 -0.0042 0.0108 -0.0257 0.0262 36 09/10/15 0.0623 0.0851 7.1020 0.4150 0.0014 0.0939 0.0014 0.0086 -0.0011 0.0089 0.0126 0.0230 36 11/20/15 0.1802 0.1193 Note 2 7.1070 0.6037 -0.0017 0.1067 0.0020 0.0131 -0.0002 0.0135 0.0086 0.0340 Note 2: Result is less than minimum detectable activity (MDA) of 0.224 pCi/g. 90 03/12/15 0.2663 0.1021 6.1880 0.2976 -0.0020 0.0665 0.0021 0.0058 -0.0035 0.0061 0.0174 0.0155 90 05/13/15 0.1291 0.0993 6.6930 0.3477 0.0049 0.0830 0.0079 0.0081 0.0016 0.0092 -0.0016 0.0199 90 07/23/15 -0.0139 0.0526 7.0070 0.3016 -0.0286 0.0583 -0.0006 0.0060 0.0032 0.0065 -0.0029 0.0167 90 12/04/15 0.0713 0.1144 8.6210 0.5996 0.0834 0.1103 -0.0009 0.0115 0.0149 0.0126 -0.0197 0.0288 3-25

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. 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 Ag-110M Sb-125 1-131 Cs-134 Cs-137 Ac-228 (+/-) (+/-) (+/-) (+/-) (+/-) (+/-) 29 01/15/15 -0.0030 0.0085 0.0015 0.0215 0.0237 0.0283 -0.0036 0.0099 0.0015 0.0093 0.0387 0.0683 29 05/12/15 0.0013 0.0045 0.0004 0.0120 0.0047 0.0134 -0.0113 0.0047 0.0026 0.0048 0.0978 0.0242 29 07/22/15 -0.0038 0.0095 0.0342 0.0236 0.0032 0.0332 -0.0193 0.0105 0.0043 0.0099 0.1282 0.0574 29 10/05/15 0.0025 0.0135 -0.0030 0.0322 -0.0214 0.0229 0.0016 0.0160 -0.0126 0.0151 0.1416 0.0633 32 01/15/15 0.0115 0.0080 -0.0054 0.0215 0.0257 0.0228 -0.0092 0.0075 -0.0154 0.0085 0.0751 0.0549 32 05/12/15 -0.0034 0.0077 0.0010 0.0233 0.0070 0.0279 -0.0007 O.Q093 0.0016 0.0084 0.0719 0.0391 Note 1 32 07/22/15 -0.0075 0.0063 0.0017 0.0167 -0.0089 0.0218 -0.0065 0.0069 0.0025 0.0065 0.0326 0.0424 32 11/20/15 0.0004 0.0113 -0.0209 0.0344 0.0196 0.0343 -0.0100 0.0122 0.0004 0.0129 0.0797 0.0800 35 01/15/15 -0.0028 0.0042 0.0051 0.0110 -0.0001 0.0119 -0.0003 0.0031 0.0003 0.0044 0.1261 0.0750 Note2 35 05/12/15 -0.0026 0.0090 -0.0076 0.0232 0.0014 0.0271 0.0028 0.0089 0.0035 0.0094 0.0078 0.0816 35 07/22/15 -0.0015 0.0082 0.0026 0.0233 -0.0034 0.0281 -0.0188 0.0088 0.0094 0.0087 0.1151 0.0623 35 10/05/15 -0.0100 0.0160 0.0034 0.0432 -0.0096 0.0260 -0.0186 0.0194 0.0052 0.0160 -0.0186 0.0695 36 01/16/15 0.0001 0.0109 -0.0028 . 0.0301 0.0173 0.0308 -0.0058 0.0133 -0.0054 0.0125 0.0802 0.0665 36 06/12/15 -0.0006 0.0095 0.0044 0.0208 0.0189 0.0341 -0.0104 0.0107 -0.0016 0.0100 0.0989 0.0483 36 09/10/15 -0.0046 0.0082 -0.0023 0.0252 -0.0043 0.0205 0.0071 0.0084 0.0075 0.0092 0.0185 0.0383 36 11/20/15 -0.0007 0.0138 -0.0041 0.0324 0.0273 0.0275 0.0017 0.0107 -0.0030 0.0140 0.0898 0.0573 Note 1 90 03/12/15 -0.0077 0.0057 0.0071 0.0165 0.0109 0.0195 -0.0025 0.0063 0.0048 0.0060 0.0552 0.0379 90 05/13/15 -0.0017 0.0078 -0.0193 0.0202 0.0044 0.0212 -0.0034 0.0090 0.0020 0.0083 0.0615 0.0472 90 07/23/15 0.0024 0.0054 0.0027 0.0148 0.0222 0.0186 0.0011 0.0063 0.0007 0.0059 0.0902 0.0479 90 12/04/15 -0.0082 0.0107 -0.0158 0.0269 0.0055 0.0286 0.0049 0.0137 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. Annual Radiological Environmental Operating Report Millstone Powet Station 2015 TABLE 13 FISH (pCi/g wet wt) COLLECTION LOCATION DATE Be-7

                                        ----------(+iT*-*  -----------r;,:r**

K-40 Cr-51

                                                                                   *----------Fi-r***         Mn-54
                                                                                                       -----------c+t:i*--           Co-58
                                                                                                                              *----------Fi-r*-*          Fe-59
                                                                                                                                                  ----------(+i'.:')""-

29 07/28/15 -0.057 0.106 4.512 0.378 -0.042 0.133 0.003 0.011 -0.010 0.012 -0.020 0.028 29 10/06/15 -0.093 0.276 3.792 0.946 0.046 0.239 0.002 0.029 0.000 0.032 0.021 0.070 32 03/23/15 -0.064 0.075 5.314 0.325 -0.108 0.095 0.002 0.008 0.001 0.009 0.005 0.021 32 04/07/15 -0.011 0.108 5.002 0.406 -0.026 0.114 -0.004 0.011 -0.011 0.012 -0.018 0.025 35 05/20/15 -0.155 0.171 4.466 0.573 0.006 0.187 -0.002 0.021 -0.014 0.021 -0.011 0.042 35 07/14/15 0.000 0.027 4.020 0.151 -0.014 0.039 0.000 0.002 -0.001 0.003 0.001 0.007 35 10/06/15 0.022 0.281 3.775 0.759 -0.082 0.312 -0.009 0.034 0.006 0.030 -0.006 0.067 COLLECTION

     .....LOCATION DATE        ------------------

Co-60 (+I-) Zn-65 (+I-) Nb-95 (+/-) Zr-95

                                                                                                       -----------c+iT--             Ru-103

(+/-) Ru-106 (+I-) 29 07/28/15 -0.005 0.012 -0.042 0.028 0.001 0.013 -0.015 0.022 -0.004 0.014 -0.099 0.104 29 10/06/15 0.000 0.025 -0.018 0.069 -0.001 0.033 -0.019 0.059 -0.012 0.032 -0 ..154 0.256 32 03/23/15 0.004 0.009 -0.027 0.018 0.002 0.009 0.010 0.016 -0.002 0.010 -0.004 0.070 32 04/07/15 0.000 0.012 -0.057 0.028 0.017 0.012 0.007 0.021 0.003 0.012 0.007 0.106 35 05/20/15 -0.009 0.020 0.020 0.044 0.010 0.020 0.001 0.035 0.008 0.022 0.028 0.192 35 07/14/15 0.002 0.002 0.001 0.006 0.002 0.003 -0.001 0.005 0.001 0.004 -0.017 0.022 _35 10/06/15 -0.013 0.030 -0.001 0.082 0.043 0.033 -0.023 0.057 -0.030 0.035 0.186 0.289 COLLECTION LOCATION DATE Ag-110M Sb-125 1-131 Cs-134 Cs-137 Ac-228

                                        ----------,+ir-*   -----------f0=i   __ _  *-----------------*

(+/-) -----------c+iT-- *-----------------* (+/-) ----------(+i:-i--- 29 07/28/15 -0.002 0.011 0.020 *0.031 0.010 0.045 0.000 0.014 0.007 0.012 -0. 050 0.047 29 10/06/15 -0.021 0.032 0.012 0.079 0.021 0.045 -0.004 0.036 0.001 0.033 -0.116 0.130 32 03/23/15 0.005 0.008 0.012 0.019 0.013 0.052 -0.004 0.008 0.000 0.008 -0.033 0.047 32 04/07/15 -0.001 0.011 -0.012 0.033 0.007 0.025 -0.043 0.012 0.002 0.012 0.008 0.061 35 05/20/15 0.009 O.Q18 -0.017 0.054 0.004 0.039 0.007 0.024 -0.007 0.021 0.035 0.080 35 07/14/15 0.001 0.002 0.003 0.006 -0.047 0.034 -0.001 0.002 0.002 0.003 -0.035 0.020 35 10/06/15 -0.039 0.030 0.053 0.100 -0.009 0.053 0.013 0.038 0.028 0.034 -0.014 0.115 3-28

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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 14 OYSTERS (pCi/g wet wt.) COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106 (+/-) ------------------ (+/-) ------------------ (+/-) ------------------ (+/-) ------------------ (+/-) ----------,+i~r--- 31 03/12/15 0.018 0.025 -0.033 0.054 0.008 0.028 0.001 0.046 0.012 0.027 0.073 0.201 31 05/21/15 0.017 0.018 -0.039 0.037 -0.010 0.016 -0.011 0.026 0.000 0.015 0.008 0.124 31 08/10/15 -0.016 0.056 -0.125 0.112 -0.007 0.050 -0.028 0.096 0.007 0.065 0.075 0.484 31 12/07/15 0.020 0.046 -0.061 0.065 0.012 0.036 -0.017 0.055 -0.024 0.034 0.022 0.287 32 03/04/15 0.020 0.029 -0.030 0.054 0.020 0.035 0.036 0.055 -0.009 0.035 0.024 0.248 32 05/19/15 0.004 0.042 -0.048 0.099 -0.003 0.044 -0.030 0.074 -0.019 0.049 0.149 0.467 32 07/10/15 0.002 0.016 -0.031 0.042 0.015 0.019 -0.017 0.033 -0.004 0.020 -0.216 0.158 32 12/09/15 -0.006 0.029 -0.027 0.071 0.022 0.047 -0.030 0.063 -0.016 0.039 0.051 0.347 88 03/05/15 0.003 0.028 -0.061 0.062 -0.024 0.030 0.000 0.054 0.025 0.037 -0.153 0.287 88 05/20/15 0.000 0.017 -0.073 0.043 0.004 0.019 0.019 0.034 0.008 0.020 -0.082 0.173 88 08/19/15 0.019 0.047 -0.043 0.106 -0.031 0.039 -0.054 0.092 0.030 0.045 -0.370 0.321 88 12/07/15 -0.002 0.043 -0.026 0.097 -0.012 0.053 -0.003 0.098 -0.028 0.047 -0.290 0.410 37 03/10/15 -0.008 0.020 -0.060 0.061 -0.008 0.023 0.043 0.050 -0.023 0.027 0.166 0.186 37 05/29/15 0.009 0.038 -0.103 0.082 0.023 0.034 0.013 0.065 0.004 0.041 -0.144 0.294 37 08/31/15 0.026 0.036 -0.133 0.094 0.005 0.036 -0.032 0.066 0.016 0.041 -0.172 0.337 37 01/15/16 -0.006 0.024 -0.062 0.059 0.035 0.024 0.007 0.045 0.004 0.027 0.195 0.231 37 is control, background location. Sample on 1/15/16, a 4th quarter 2015 sample was collected late. See discussion. 3-30

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 14 OYSTERS (pCi/g wet wt.) COLLECTION LOCATION DATE Ag-110M Sb-125 1-131 Cs-134 Cs-137 Ac-228

* ------------ ----------(+i:) ___ ------------------

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

                                                                                                                                                        ----------(+i:)  ___

31 03/12/15 0.011 0.023 -0.016 0.053 0.023 0.080 -0.015 0.025 0.010 0.028 0.010 0.090 31 05/21/15 0.000 0.015 -0.009 0.038 -0.007 0.026 0.001 0.017 -0.002 0.017 0.023 0.067 31 08/10/15 -0.001 0.048 0.005 0.135 0.106 0.119 -0.002 0.069 0.038 0.055 0.149 0.178 31 12/07/15 0.014 0.031 0.000 0.079 -0.020 0.041 0.001 0.032 -0.030 0.033 -0.185 0.162 32 03/04/15 -0.013 0.026 -0.028 0.073 -0.143 0.111 0.017 0.029 0.011 0.027 0.101 0.103 32 05/19/15 -0.005 0.048 -0.071 0.121 -0.030 0.098 -0.073 0.050 -0.014 0.051 -0.067 0.187 32 07/10/15 0.017 0.017 0.011 0.044 0.004 0.042 0.014 0.019 -0.009 0.018 0.016 0.071 32 12/09/15 -0.019 0.041 -0.012 0.104 -0.002 0.068 0.027 0.042 0.013 0.043 -0.043 0.148 88 03/05/15 0.000 0.029 0.048 0.077 0.063 0.120 0.004 0.032 -0.017 0.033 0.055 0.134 88 05/20/15 0.009 0.016 0.039 0.050 0.000 0.034 0.005 0.021 -0.005 0.019 0.097 0.091 88 08/19/15 0.026 0.038 0.025 0.134 0.021 0.070 -0.029 0.052 -0.005 0.046 0.254 0.169 Note 88 12/07/15 -0.016 0.042 0.080 0.124 -0.096 0.085 -0.058 0.049 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. 37 03/10/15 -0.001 0.021 0.021 0.063 0.002 0.066 -0.031 0.026 . -0.014 0.024 -0.041 0.094 37 05/29/15 -0.023 0;029 0.003 0.088 -0.054 0.103 -0.003 0.036 0.000 0.032 -0.092 0.139 37 08/31/15 0.012 0.037 0.040 0.101 0.027 0.074 -0.002 0.041 -0.008 0.040 0.031 0.139 37 01/15/16 -0.028 0.025 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 15 CLAMS (pCi/g wet wt.) COLLECTION LOCATION DATE Be-7 (+/-) K-40

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

Cr-51 (+/-) Mn-54

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

Co-58

                                                                                                                                      ------------(+i~)---- *-------------------

Fe-59 (+/-) 29 03/12/15 0.077 0.350 1.769 0.717 -0.455 0.425 0.015 0.041 0.025 0.035 0.016 0.065 29 06/09/15 0.032 0.204 2.379 0.726 -0.033 0.229 0.000 0.021 -0.019 0.026 0.005 0.054 29 07/24/15 0.265 0.348 2.275 0.772 0.021 0.380 0.003 O.Q35 -0.023 0.034 0.012 0.070 29 10/07/15 0.314 0.243 2.775 0.819 0.173 0.245 0.012 0.024 -0.005 0.026 -0.008 0.042 38 06/11/15 0.126 0.268 2.144 0.604 0.058 0.297 0.005 0.028 -0.001 0.033 0.007 0.062 38 08/04/15 0.055 0.358 2.205 0.951 -0.343 0.431 -0.002 0.037 0.015 0.051 -0.045 0.090 38 10/27/15 0.096 0.406 1.992 1.251 Note -0.088 0.544 -0.009 0.056 0.001 0.059 -0.087 0.085 Note: Results is less than minimum detectable activity (MDA) of 2.67 pCi/g. COLLECTION LOCATION DATE Co-60 Zn-65 Nb-95 Zr-95 Ru-103 Ru-106

                              *-----------f+1:r*--       *-----------Fi-r*--         -----------(:;:.i_y---* -----------(+i~----*     ------------(+i~f---- *----------7+,:)   ___ _

29 03/12/15 -o.01 o 0.036 -o .034 0.066 0.041 0.039 -0.001 0.063 0.001 0.045 0.025 0.351 29 06/09/15 0.009 0.027 0.000 0.056 0.021 0.025 -0.009 0.046 -0.017 0.025 0.064 0.189 29 07/24/15 0.005 0.031 -0.022 0.091 0.028 0.042 -0.049 0.066 0.004 0.045 -0.070 0.344 29 10/07/15 -0.010 0.027 0.021 0.061 O.Q15 0.031 0.016 0.052 -0.009 0.029 -0.126 0.222 38 06/11/15 -0.002 0.027 -0.052 0.059 0.001 0.029 0.007 0.050 0.031 0.033 -0.085 0.261 38 08/04/15 0.011 0.043 0.072 0.099 -0.028 0.044 -0.016 0.067 0.008 0.051 -0.123 0.415 38 10/27/15 0.009 0.055 -0.048 0.151 -0.013 0.053 0.085 0.096 -0.010 0.055 0.091 0.460 COLLECTION ______e-JJ:].~~1~1_ ____ _ LOCATION DATE (+/-) Sb-125 (+/-) 1-131 (+/-) -------------------* Cs-134 (+/-) Cs-137 (+/-) Ac-228 (+/-) 29 03/12/15 0.003 0.037 0.063 0.100 -0.048 0.121 -0.044 0.040 -0.028 0.042 0.128 0.141 29 06/09/15 0.027 0.023 -0.013 0.063 -0.023 0.042 0.007 0.032 -0.010 0.026 0.028 0.111 29 07/24/15 0.010 0.034 -0.050 0.084 0.037 0.143 0.007 0.037 0.036 0.036 0.084 0.155 29 10/07/15 -0.008 0.027 -0.016 0.087 -0.083 0.050 0.006 0.031 -0.016 0.032 -0.046 0.117 38 06/11/15 -0.001 0.028 0.024 0.073 0.144 0.120 -0.023 0.030 0.029 0.028 0.079 0.109 38 08/04/15 -0.009 0.043 -O.Q38 0.107 0.042 0.152 -0.035 0.043 0.007 0.039 *0.018 0.159 38 10/27/15 -0.010 0.054 -0.051 0.171 0.015 0.100 -0.043 0.065 -0.001 0.056 0.144 0.220 3-32

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 TABLE 16 LOBSTERS (pCi/g wet wt.) COLLECTION LOCATION DATE Be-7 (+/-) -------------------* K-40 (+/-) Cr-51

                                                                                       ------------r+i-r--*         Mn-54
                                                                                                            ------------1+,:r*-*            Co-58
                                                                                                                                    ------------i+i-r--*         Fe-59
                                                                                                                                                         ------------,+,:r*-*

35 03/24/15 0.228 0.320 2.355 0.738 -0.151 0.387 -0.004 0.032 -0.011 0.033 -0.009 0.075 35 05/26/15 -0.150 0.201 3.004 0.691 -0.087 0.196 0.018 0.021 -0.015 0.029 -0.015 0.054 35 07/30/15 0.203 0.412 3.122 1.043 -0.235 0.527 -0.013 O.D38 -0.022 0.051 0.089 0.100 35 10/22/15 -0.046 0.384 3.083 1.586 0.089 0.401 -0.026 0.044 -0.057 0.051 0.013 0.080 89 03/20/15 -0.023 0.528 2.549 0.968 0.149 0.725 0.000 0.038 0.008 0.044 0.090 0.106 89 06/19/15 -0.341 0.321 2.687 0.964 0.005 0.282 0.009 0.033 -0.022 0.037 -0.038 0.088 89 08/18/15 -0.167 0.258 2.544 0.731 -0.007 0.260 0.003 0.030 -0.004 0.029 -0.004 0.055 89 12/08/15 0.064 0.486 3.880 1.618 0.258 0.491 0.013 0:073 -0.007 0.059 0.023 0.149 (89 is control, background location) COLLECTION LOCATION DATE Co-60 Zn-65

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

Nb-95 (+/-) Zr-95 (+/-) -------------------* Ru-103 (+/-) ------------,+i-r--* Ru-106 35 03/24/15 0.008 0.032 -0.032 0.070 0.008 0.037 0.024 0.068 -0.003 0.042 0.152 0.290 35 05/26/15 0.012 0.025 -0.050 0.058 0.002 0.025 -0.028 0.048 0.012 0.023 -0.035 0.215 35 07/30/15 0.002 0.039 -0.083 0.098 0.010 0.045 .-0.022 0.091 0.027 0.056 -0.030 0.380 35 10/22/15 0.010 0.056 -0.067 0.131 0.026 0.052 0.073 0.073 0.027 0.049 0.068 0.415 89 03/20/15 0.023 0.049 -0.038 0.100 -0.041 0.046 -0.012 0.079 -0.051 0.065 -0.058 0.433 89 06/19/15 -0.010 0.033 0.002 0.084 0.003 0.042 -0.002 0.068 -0.001 0.036 0.088 0.316 89 08/18/15 -0.010 0.028 -0.056 0.073 0.004 0.029 0.007 0.050 0.011 0.027 -0.141 0.255 89 12/08/15 0.028 0.040 -0.090 0.152 0.044 0.061 0.099 0.130 -0.034 0.060 -0.339 0.571 COLLECTION LOCATION DATE Ag-110M

                                          ------------(+i-r--*         Sb-125
                                                                ------------Fi-i*--*   -------------------*

1-131 (+/-) Cs-134

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

Cs-137 (+/-) Ac-228

                                                                                                                                                         ------------,.tt:r*-*

35 03/24/15 -0.008 0.028 -0.010 0.075 0.254 0.203 -0.058 0.036 0.010 0.028 -0.015 0.112 35 05/26/15 0.009 0.020 -0.014 0.061 0.027 0.052 -0.009 0.030 0.009 0.024 -0.003 0.096 35 07/30/15 0.029 0.041 0.044 0.150 -0.016 0.160 -0.068 0.056 -0.039 0.042 -0.162 0.211 35 10/22/15 -0.035 0.044 0.001 0.131 -0.020 0.067 0.018 0.049 -0.014 0.049 0.042 0.251 89 03/20/15 -0.021 0.042 -0.096 0.121 -0.238 0.481 -0.032 0.045 0.030 0.043 -0.005 0.142 89 06/19/15 0.000 0.033 0.001 0.085 -0.025 0.083 0.007 0.032 0.027 0.039 0.037 0.124 89 08/18/15 -0.003 0.027 0.013 0.074 0.014 0.049 -0.003 0.035 0.000 0.029 -0.159 0.094 89 12/08/15 0.016 0.060 0.109 0.166 0.039 0.091 -0.006 0.070 0.009 0.064 0.019 0.233 3-33

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

4. DISCUSSION OF RESULTS 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 Figiue 4.1-1 uR/hr Aiun1al l~e,u1una Exiiostrre Rate-20Year Histo1y IAll Indicators 10 1All Controls I Indicator Loe 1 cl ndicator Loe 3 8 6 ..- .... CD (j) a N (T') -.:i- LO r-... CD Q) 0

                                                                                                      .... N   (T) '<:t   L[')

Q) (j) a 0 a 0 0 D 0 0 ..- ..- ..- ...... .- m m 0 N 0 N 0 N 0 N 0 N 0 N 0 N 8N 0 N 0 N 0 N 0 N 0 N 0 N 0 N 4-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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. Figure 4.2-1 Air Particulate Gross Beta Activity pCi/m 3 Monthly Averages - 2015 0.019 ~-----------------------------

                                  -+- Indicators            -...control 0.007      +------.---~-----.---~-----.---~-----.---~-----.---~--.,.-----,

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 4.2-2 Air Particulate Gross Beta Activity pCi/m' Monthly Averages - 5 Year Trend 0.021 + - - - - - - - - - - - - --ti'-- - - - - - - - - - - - - - - - - - -

                                                                                                                         -+- Indicators           ..... Control 0.009 + - - - - - - -- ---i- - - - - - - - - - - - - - - - - - ---'1-- - -

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Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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. Figure 4.6-1 Cs-137 in Soil 1.8 ..,--- - - - - - - -- - - - - - - - - - - - - - - --

                                                                        -  -   Loe 3      -

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Loe 14 1.6 +-

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0 + - - - - - - - ,- -- - - - - . - - - - - - r - - - - , . . - - - - - , - - - - - - r - - - - - - , 2001 2003 2005 2007 2009 2011 2013 2015 Year 4-5

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 4.6 Cow Milk (Table 6) 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 4.10 Seawater (Table 10) 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 Figure 4.14-1 H-3 Curies Released versus Seawater Concentration 18 Year Trend 1700 1600 1500 - Cmies discba[ged 1400 - - REMP pl!i!liter 1300 1200 1100 ~ I 1000 900

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0 -

4.11 Bottom Sediment (Table 11) 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. Annu al Radiological Environmental Operating Report Millstone Power Station 2015 4.14 Oysters (Table 14) 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015

5. REFERENCES

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

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

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

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

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

December 1987.

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

6) 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 APPENDIX A LAND USE CENSUS FOR 2015 A-1

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 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 Beave r Brook Farm Old Lyme yougurt (cow&sheep), lamb NNE 10.9 Ho lmberg 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 vegeta bles, apple butter and sauce NNW 11.9 Soeltl Farm Salem Eggs, beef, chicken, fowl, pork, turkey, vea l 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 Th e Funny Farm Ledyard Fruits and vegetabl es NE 12.5 Cedar Meadows Farm Ledyard Eggs, chicken, lamb, pork, t urkey NW 12.6 Provider Farm Salem Vegetables, beef, veal ENE 12.6 Starry Night Farm Stonington Vegetables, eggs NE 12.7 Maugle Sierra Vineyard s Ledyard Win e 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 Vin eyard Stonington Grapes, wine NE 14.8 Wychwood Turkey Farm Stonington Turkey ENE 15.2 Stonington Vineyards Stonington Wine NE 15.5 Ro se ledge 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 m ea l, feed NE 16.9 LoPresti Farm Preston Vegetabl es 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 Vegetabl es ENE 17.3 GYOCT Pawcatuck,CT Vegetabl es, strawb erri 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 M eadows 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 APPENDIX B

SUMMARY

OF INTERLABORATORY COMPARISONS B-1

Dominion Nuclear Connecticut, Inc. Annual Radiolog ical Environmental Operating Report Millstone Power Station 2015 INTRODUCTION 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. Annual Radiological Environmental Operating Report Millstone Power Station 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 Id e ntifica ti o n Re p o rte d Kn o wn R a t io (c)

M o nth/Yea r Nu mbe r M a tri x Nu c lide Units V a lu e (a ) Va lue (b) TBE /An a l:i:;t ics E v a lu a ti o n (d ) M a r c h 2015 E 111 8 1 Mil k S r-89 pCi/L 88.9 97.2 0.9 1 A S r-90 pC i/L 1 2 .2 1 7.4 0.70 w E 111 82 Mil k 1- 1 3 1 p C i/L 6 1 .3 65. 1 0.94 A Ce- 1 4 1 pC i/ L 1 04 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 pC i/L 205 207 0.99 A Co-58 pC i/ L 178 1 83 0.97 A Mn-54 p C i/ L 18 7 1 88 0.99 A Fe-59 p C i/ L 1 82 17 7 1 .03 A Z n -65 pC i/ 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 pC i 107 85.0 1.26 w C r-5 1 pC i 26 1 224 1 .1 7 A Cs- 1 34 pC i 7 4 .6 77.0 0.97 A Cs- 1 37 pC i 99.6 1 02 0.98 A Co-58 pC i 99.8 11 0 0.9 1 A Mn-54 pC i 99 . 2 96.9 1 .02 A F e-59 pC i 109 11 9 0.92 A Z n -65 pC i 1 88 1 83 1 .03 A C o -60 pC i 200 20 1 1 .00 A E 111 83 C h a r coa l 1- 1 3 1 pC i 82 . 9 85.4 0.97 A E 111 85 W ater Fe-55 pCi/ L 1 950 1 900 1 .03 A B-3

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 2015 A N ALYTICS E NVI RO NMENT A L RADIOAC TIV ITY C ROSS CH ECK P RO GRAM TELE D Y N E BRO W N ENGIN E ERIN G E NVIRONM E NTAL SERVICES Identification Reported Known Ratio (c) Month/Year Number Matrix Nuclide U nits Va lue(a) Va lue (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 pC i Not prov ided 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 Mi lk 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 F e-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 Soi l 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 Ma rch 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 RAD IOACTIVITY 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 Eva luation (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 .7 7 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/sa mple -0.0096 (1) A Co-60 Sq/s ample 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 20 15 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 .68 1 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/sa mple 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 .6 1 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 .9 1 - 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 p C 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-N at 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 ANALYTICS ENVIRONMENTAL RADIOACTIVITY CROS S CHECK PROGRAM T ELEDYNE BROWN ENGINEERIN G 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 Charcoa l 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-5 1 - 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 P ower Station 2015 I DOE's MIXED ANALYTE 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/sa mple 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. Annual Radiological Environmental Operating Report Millstone P wer Station 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 Serial No. 16-166 Attention: Document Control Desk MPS Lic/AVM RO Washington, DC 20555-0001 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 DOMINION NUCLEAR CONNECTICUT, INC. MILLSTONE POWER STATION UNITS 1, 2, AND 3 2015 ANNUAL RADIOLOGICAL ENVIRONMENTAL OPERATING REPORT 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

Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 2of4 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 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

Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 3of4 (2copies) Director Bureau of Air Management Monitoring & Radiation Division 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

Serial No. 16-166 2015 Annual Radiological Environmental Operating Report Page 4 of 4 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 Docket Nos. 50-245 50-336 50-423 License Nos. DPR-21 DPR-65 NPF-49 ATTACHMENT 1 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015

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

SUMMARY

INTRODUCTION 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015

1. INTRODUCTION 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. Annual Radiological Environmental Operating Report Millstone Power Station 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 MAN-MADE Radiation Dose Radiation Dose Source (mrem/vear) Source (mrem/year) Internal, inhalation<2l 228 Medica1(3l 300 External, space 33 Consumer(4l 13 Internal, ingestion 29 Industrial, security, 0.3 educational, research External, terrestrial 21 Occupational 0.5 Weapons Fallout < 1 Nuclear Power Stations < 1 Approximate Total 311 Approximate Total 314 {1) information from References 3 and 4 (2) from radon and thoron (3) includes computerized tomography (147 mrem), nuclear medicine (77 mrem), interventional fluoroscopy (43 mrem) and conventional radiography and fluoroscopy (33 mrem) (4) primarily from cigarette smoking (4.6 mrem), commercial air travel (3.4 mrem), building materials (3.5 mrem) and mining and agriculture (0.8 mrem) 1-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annu al Radiological Environmental Operating Report Millstone Power Station 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 Lig ht Water Reactor (LWR)

                                                             * ~----------.....,* co NO ENSER COO UNG WATER
                                                             -.;;...;,;;;,,;;,;,,;;;;,;;i;iiii0ii_ _,TA.KiNC WASTE HEAT TOTHE ENViRONMEN't Figure 1.4-1 1-4

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

Uranium 1.,... Neutrons WlllJJ Neutron Uranium Fission Products Uranium Fission Products Figure 1.4-2 Radioactive Fission Product Formation 1-5

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

                          *col.ii~icm

with 0

                      .                                                  **~

Co-60 stable Radioactive.

co6alt Nucleus *cci*balt::Ntic1eus Figure 1.4-3 Radioactive Activation Product Formation 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. Annual Radiological Entjronmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 1.5 Radioactive Effluent Control The small amounts of radioactive liquids arid gases that might escape the first two barriers 1 are processed in the liquid and gaseous waste treatment systems, then monitored for radioactivity, and released only if the radioactivity levels are below the federal release limits. Radioactivity released from the liquid effluent system to the environment is limited, controlled, and monitored by a variety of systems and procedures which include:

reactor water cleanup system;
liquid radwaste treatment system;
sampling and analysis of the liquid radwaste tanks; and,
liquid waste effluent discharge radioactivity monitor.

The purpose of the reactor water cleanup system is to continuously purify the reactor cooling water by removing radioactive atoms and non-radioactive impurities that may become activated by neutron bombardment. A portion of the reactor coolant water is diverted from the primary coolant system and is directed through ion exchange resins where radioactive elements, dissolved and suspended in the water, are removed through chemical processes. The net effect is a substantial reduction of the radioactive material that is present in the primary coolant water and consequently the amount of radioactive material that might escape from the system. Reactor cooling water that might escape the primary cooling system and other radioactive water sources are collected in floor and equipment drains. These drains direct this radioactive liquid waste to large holdup tanks. The liquid waste collected in the tanks is purified again using the liquid radwaste treatment system, which consists of a filter and ion exchange resins. Processing of liquid radioactive waste results in large reductions of 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 EXAMPLES OF Millstone's RADIATION EXPOSURE PATHWAYS LIQUID EFFLUENTS

3. DIRECT RADIATION (STATIO~ 2. AIR INHALATION ef /V"" / 1. DIRECT RADIATION

                                                 . *e        LY                e;sMERs10NJ
                                                ~

1. SHORELINE DIRECT RADIATION (FISHING, PICNICJNG) ~

4.-

5. CONSUMPTION (VEGETATION) t DEPOSITION

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

(/

                                                                 &B:m; ~

DEPOSITION INGESTION

3. CONSUMPTION (FISH, SHELLFISH)

Figure 1.6 Radiation Exposure Pathways 1-11

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

2. PROGRAM DESCRIPTION 2.1 Sampling Schedule and Locations 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 Table 2-1 Environmental Monitoring Program Sampling Types and Locations

.:;::.;::::::;:,:c::;: Onsite - Old Millstone Rd. 0.6 Mi, NNW TLD, Air Particulate, Iodine, Vegetation Onsite - Weather Shack 0.3 Mi, S TLD, Air Particulate, Iodine Onsite - Bird Sanctuary 0.3 Mi, NE TLD, Air Particulate, Iodine, Soil Onsite - Albacore Drive 1.0 Mi, N TLD, Air Particulate, Iodine, Soil Onsite - MP3 Discharge 0.1 Mi, SSE TLD Onsite - Quarry Discharge 0.3 Mi, SSE TLD Onsite - Env. Lab Dock 0.3 Mi, SE TLD Onsite- Env. Lab 0.3 Mi, SE TLD Onsite - Bay Point Beach 0.4 Mi, W TLD

 ..,. *.:***'"*****""' Pleasure Beach                    1.2 Mi, E          TLD, Air Particulate, Iodine, Vegetation Great Neck Country Club    1.6 Mi, ENE        TLD, Air Particulate, Iodine Fisher's Island, NY        8.0 Mi, ESE        TLD Mystic, CT                 11.5 Mi, ENE       TLD Ledyard, CT                12.0 Mi, NE        TLD, Soil Norwich, CT                14.0 Mi, N         TLD, Air Particulate, Iodine
 '*""'""""""'           Old Lyme, CT               8.8Mi,W            TLD Site Boundary              0.5 Mi, NE         Vegetation Cow                        10.5 Mi, WNW        Milk Within 10 Miles            < 10 Miles         Vegetation 3

Within 10 Miles < 10 Miles Fruits and/or Vegetables Beyond 10 Miles > 10 Miles Vegetation . 3

  ..........~"*"""***         Beyond 10 Miles            > 10 Miles          Fruits and/or Vegetables Niantic                    1.?Mi, WNW         TLD, Air Particulate, Iodine 4

Two Tree Island 0.8Mi, SSE Fish West Jordan Cove 0.4 Mi, ENE-ESE Clams, Fish4 West Jordan Cove 0.4 Mi, NNE Fucus '*'"'""*"'***.<**>.*'"** Niantic Shoals 1.8 Mi, NW Bottom Sediment, Oysters 4 Vicinity of Discharge < 0.1 Mi Bottom Sediment, Oysters, Fish , Seawater Vicinity of Discharge < 0.1 Mi Fucus Seaside Point 1.8 Mi, ESE Bottom Sediment Niantic Bay <0.5 Mi, SSW-W Lobster, Fish 4 Niantic Bay 0.3 Mi, WNW Fucus Black Point 3.0Mi,WSW Fucus

 ,.,;.;;:,;,,;;;:*>:":.:*,    Giant's Neck               3.5 Mi, WSW         Bottom Sediment, Oysters, Seawater Waterford Shellfish Bed #1 1.0 Ml, NW         Clams Myrock Avenue              3.2 Mi, ENE        TLD Billow Road                2.4 Mi, WSW        TLD Black Point                2.6 Mi, SW         TLD Onsite - Schoolhouse       0.1 Mi, NNE        TLD Onsite - Access Road       0.5 Mi, NNW        TLD
   ....... .,..........,."'". Old Lyme - Hillcrest Ave. 4.6Mi,WSW          TLD East L me - W. Main St. 4.5Mi,W            TLD 2-2

Dominion Nuclear Connecticut, Inc. Annual Radiological Environmental Operating Report Millstone Power Station 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 5 MW-GPl-1 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. Annual Radiological Environmental Operating Report Millstone Power Station 2015 Table 2-2 Required Sampling Frequency & Type of Analysis

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