ML11213A203

NUREG-1437 Supp 46 Dfc (2 of 2) Generic Environmental Impact Statement for License Renewal of Nuclear Plants: Regarding Seabrook Station (Draft for Comment)

ML11213A203
Person / Time
Site:	Seabrook
Issue date:	07/31/2011
From:	Michael Wentzel Office of Nuclear Reactor Regulation
To:
Beltz, G
References
NUREG-1437 Supp 46 DFC
Download: ML11213A203 (309)

Text

APPENDIX D CONSULTATION CORRESPONDENCE

Appendix D 1 D CONSULTATION CORRESPONDENCE 2 The Endangered Species Act of 1973, as amended; the Magnuson-Stevens Fisheries 3 Management Act of 1996, as amended; and the National Historic Preservation Act of 1966 4 require that Federal Agencies consult with applicable State and Federal agencies and groups 5 prior to taking action that may affect threatened or endangered species, essential fish habitat, or 6 historic and archaeological resources, respectively. This appendix contains consultation 7 documentation.

8 Table D-1 provides a list of the consultation documents sent between the U.S. Nuclear 9 Regulatory Commission (NRC) and other agencies. The NRC staff is required to consult with 10 these agencies based on the National Environmental Policy Act of 1969 (NEPA) requirements.

11 Table D-1. Consultation Correspondence Author Recipient Date of Letter/Email Simon, B., Massachusetts Historical Holian B., NRC March 3, 2010 Commission (ML100880129)

Pham, B., NRC Nelson, R., Advisory Council on Historic July 16, 2010 Preservation (ML101760128)

Pham, B., NRC Kurkul, P., National Marine Fisheries Service July 16, 2010 (NMFS), Northeast Region (ML101760221)

Pham, B., NRC Muzzey, E., New Hampshire Division of July 16, 2010 Historical Resources (ML101790273)

Pham, B., NRC Moriarty, M., U.S. Fish and Wildlife Service July 16, 2010 (USFWS), Northeast Region (ML101790278)

Feighner, E., New Hampshire Division Pham, B., NRC July 27, 2010 of Historical Resources (ML102160299)

Kurkul, P., NMFS, Northeast Region Pham, B., NRC August 5, 2010 (ML102240108)

Pham, B., NRC Coppola, M., New Hampshire Natural August 26, 2010 Heritage Bureau (ML102290417)

Chapman, T., USFWS, Northeast Pham, B., NRC September 1, 2010 Region (ML102630180)

Coppola, M., New Hampshire Natural Susco, J., NRC September 7, 2010 Heritage Bureau (ML102520087)

Coppola, M., New Hampshire Natural Susco, J., NRC September 13, 2010 Heritage Bureau (ML102600341)

D-1

Appendix D 1 D.1 Consultation Correspondence 2 The following pages contain copies of the letters listed in Table D-1.

D-2

Appendix D D-3

Appendix D D-4

Appendix D D-5

Appendix D D-6

Appendix D D-7

Appendix D D-8

Appendix D D-9

Appendix D D-10

Appendix D D-11

Appendix D D-12

Appendix D D-13

Appendix D D-14

Appendix D D-15

Appendix D D-16

Appendix D D-17

Appendix D D-18

Appendix D D-19

Appendix D D-20

Appendix D D-21

Appendix D D-22

Appendix D D-23

Appendix D D-24

Appendix D D-25

Appendix D D-26

Appendix D D-27

Appendix D D-28

Appendix D D-29

Appendix D D-30

Appendix D D-31

Appendix D D-32

Appendix D D-33

Appendix D D-34

Appendix D D-35

Appendix D D-36

Appendix D D-37

Appendix D D-38

Appendix D D-39

Appendix D D-40

Appendix D D-41

Appendix D D-42

Appendix D D-43

Appendix D D-44

Appendix D D-45

Appendix D D-46

Appendix D D-47

Appendix D D-48

Appendix D D-49

Appendix D D-50

Appendix D D-51

Appendix D D-52

Appendix D D-53

Appendix D D-54

Appendix D D-55

Appendix D D-56

Appendix D D-57

Appendix D D-58

Appendix D D-59

Appendix D D-60

Appendix D D-61

Appendix D D-62

Appendix D D-63

Appendix D D-64

Appendix D D-65

Appendix D D-66

Appendix D D-67

Appendix D D-68

Appendix D D-69

Appendix D D-70

Appendix D D-71

Appendix D D-72

Appendix D D-73

Appendix D D-74

Appendix D D-75

Appendix D D-76

Appendix D D-77

Appendix D D-78

Appendix D D-79

Appendix D D-80

Appendix D D-81

Appendix D D-82

Appendix D D-83

Appendix D D-84

Appendix D D-85

Appendix D D-86

Appendix D D-87

Appendix D D-88

Appendix D D-89

Appendix D D-90

Appendix D D-91

Appendix D D-92

Appendix D D-93

Appendix D D-94

Appendix D D-95

Appendix D D-96

Appendix D D-97

Appendix D D-98

Appendix D D-99

Appendix D D-100

Appendix D D-101

Appendix D D-102

Appendix D D-103

Appendix D D-104

Appendix D D-105

Appendix D D-106

Appendix D D-107

Appendix D D-108

Appendix D D-109

Appendix D D-110

Appendix D D-111

Appendix D D-112

Appendix D D-113

Appendix D D-114

Appendix D D-115

Appendix D D-116

Appendix D D-117

Appendix D D-118

Appendix D D-119

Appendix D D-120

Appendix D D-121

Appendix D D-122

Appendix D D-123

Appendix D D-124

Appendix D D-125

Appendix D D-126

Appendix D D-127

Appendix D D-128

Appendix D D-129

Appendix D D-130

Appendix D D-131

Appendix D D-132

Appendix D D-133

Appendix D D-134

Appendix D D-135

Appendix D D-136

Appendix D D-137

Appendix D D-138

Appendix D D-139

Appendix D D-140

APPENDIX D-1 ESSENTIAL FISH HABITAT ASSESSMENT

Essential Fish Habitat Assessment Seabrook Station, Unit 1 License Renewal May 2011 Docket Number 50-443 U.S. Nuclear Regulatory Commission Rockville, Maryland

TABLE OF CONTENTS D-1.1 Introduction ................................................................................................................ D-1-1 D-1.2 Description of the Proposed Action ............................................................................ D-1-1 D-1.2.1 Site Location and Description .......................................................... D-1-2 D-1.2.1.1 Cooling and Auxiliary Water Systems ............................................ D-1-2 D-1.3 Essential Fish Habitat Species Near the Site and Potential Adverse Effects ............................................................................................................. D-8 D-1.3.1 Essential Fish Habitat Species Identified for Analysis ..................... D-1-8 D-1.3.2 Potential Adverse Effects to Essential Fish Habitat ....................... D-1-10 D-1.3.2.1 Information Related to Potential Adverse Impact on All Essential Fish Habitat Species ................................................................... D-1-13 D-1.3.2.2 Combined Impacts (Monitoring Data) .......................................... D-1-24 D-1.3.3 Adverse Effects on Essential Fish Habitat by Species .................. D-1-32 D-1.3.3.1 American Plaice (Hippoglossoides platessoides) (Juvenile and Adult) ................................................................................... D-1-32 D-1.3.3.2 Atlantic butterfish (Peprilus triacanthus) (All Life Stages) ............ D-1-34 D-1.3.3.3 Atlantic cod (Gadus morhua) (All Life Stages)............................. D-1-36 D-1.3.3.4 tlantic herring (Clupea harengus) (Juvenile and Adult) ................ D-1-39 D-1.3.3.5 Atlantic mackerel (Scomber scombrus) (All Life Stages)............. D-1-41 D-1.3.3.6 tlantic sea scallop (Placopecten magellanicus) (All Life Stages)................................................................................. D-1-44 D-1.3.3.7 Atlantic Surfclam (Spisula solidissima) (Juveniles and Adults) .... D-1-46 D-1.3.3.8 Haddock (Melanogrammus aeglefinus) (Juvenile) ....................... D-1-47 D-1.3.3.9 Monkfish/Goosefish (Lophius americanus) (All Life Stages) ....... D-1-49 D-1.3.3.10 Ocean pout (Macrozoarces americanus) (All Life Stages)................................................................................. D-1-51 D-1.3.3.11 Pollock (Pollachius virens) (Juvenile)......................................... D-1-53 D-1.3.3.12 Red hake (Urophycis chuss) (All Life Stages) ........................... D-1-55 D-1.3.3.13 Scup (Stenotomus chrysops) (Juvenile and Adult) .................... D-1-57 D-1.3.3.14 Summer flounder (Paralicthys dentatus) (Adult) ........................ D-1-59 D-1.3.3.15 Whiting/Silver hake (Merluccius bilinearis)

(All life stages) ............................................................................ D-1-60 D-1.3.3.16 Windowpane flounder (Scopthalmus aquosus) (Juveniles and Adults) ................................................................................. D-1-63 D-1.3.3.17 Winter flounder (Pleuronectes americanus) (All Life Stages) .... D-1-65 D-1.3.3.18 Yellowtail flounder (Pleuronectes ferruginea) (Juveniles and Adults) ................................................................................. D-1-67 D-1.3.3.19 Essential Fish Habitat Species Not Likely to Regularly Occur Near Seabrook ................................................................................. D-1-69 D-1.4 Cumulative Effects to Essential Fish Habitat ........................................................... D-1-70 D-1.5 Essential Fish Habitat Conservation Measures ....................................................... D-1-73 D-1.6 Conclusion ............................................................................................................... D-1-73 D-1.7 References ............................................................................................................... D-1-75 D-1-i

Figures Figure D-1-1. Location of Seabrook Station, 6-mi (10-km) region ........................................ D-1-3 Figure D-1-2. Location of Seabrook Station, 50-mi (80-km) region ...................................... D-1-4 Figure D-1-3. Seabrook Station site boundary and facility layout ......................................... D-1-5 Figure D-1-4. Intake shafts and caps at Seabrook Station ................................................... D-1-6 Figure D-1-5. Profile of intake tunnel and shafts at Seabrook Station .................................. D-1-7 Figure D-1-6. Circulating water pumphouse at Seabrook Station ......................................... D-1-8 Figure D-1-7. Sampling Stations for Seabrook Station aquatic monitoring ......................... D-1-25 Tables Table D-1-1. Species of fish with designated EFH in the vicinity of Seabrook ..................... D-1-9 Table D-1-2. Relative commonness of EFH species in Seabrook monitoring, entrainment, and impingement studies ...................................................................................... D-1-11 Table D-1-3. Aquatic resource issues identified in the GEIS .............................................. D-1-13 Table D-1-4. Number of fish eggs entrained (in millions) for most common egg taxa entrained and for EFH species ...................................................................................... D-1-15 Table D-1-5. Number of fish larvae entrained (in millions) for the most common larval taxa entrained and for EFH species ...................................................................... D-1-17 Table D-1-6. Number of impinged fish for the most common taxa impinged and for EFH species .................................................................................................. D-1-19 Table D-1-7. Number of bivalve larvae entrained (x 109) .................................................... D-1-21 Table D-1-8. Mean density (No./1000m3) and upper and lower 95% confidence limits (CL) of the most common fish eggs and larvae from 1982-2009 monitoring data at Seabrook ....................................................................................................... D-1-26 Table D-1-9. Geometric mean catch per unit effort (CPUE) (No. per 10-minute tow) and upper and lower 95% CL during preoperational and operational monitoring years for the most abundant species .................................................................................. D-1-27 Table D-1-10. Geometric mean CPUE (No. per 24-hr surface and bottom gill net set) and coefficient of variation (CV) during preoperational (1976-1989) and operational monitoring years (1990-1996) ....................................................................... D-1-28 Table D-1-11. Geometric mean CPUE (No. per seine haul) and upper and lower 95% CL during preoperational and operational monitoring years .......................................... D-1-30 Table D-1-12. Kelp density (No. per 100 m2) and upper and lower 95% CL during preoperational and operational monitoring years .......................................... D-1-31 Table D-1-13. Summary of NRC conclusions Regarding the Effect on Habitat by Species and Life Stages ..................................................................................................... D-1-73 D-1-ii

ABBREVIATIONS, ACRONYMS, AND SYMBOLS ac acre ADAMS Agencywide Documents Access and Management System BACI before-after control-impact CFR U.S. Code of Federal Regulations cfs cubic feet per second CL confidence limit cm centimeter CO2 carbon dioxide CPUE catch per unit effort CV coefficient of variation CWA Clean Water Act DFO Fisheries and Oceans Canada EEP Estuary Enhancement Program EFH Essential Fish Habitat EPA U.S. Environmental Protection Agency ER environmental report FPLE Flordia Power Light Energy Seabrook fps feet per second FR Federal Register ft foot FMP fishery management plan GEIS Generic Environmental Impact Statement gpm gallons per minute ha hectare in. inch kg kilogram km kilometer lb pound m meter m/s meters per second m3 cubic meters m3/day cubic meters per day m3/s cubic meters per second m3/yr cubic meters per year MAFMC Mid-Atlantic Fishery Management Council MARMAC Marine Resources Monitoring, Assessment, and Prediction MDS multi-dimensional scaling mgd million gallons per day mi mile D-1-iii

mm millimeter MSA Magnuson-Stevens Fishery and Conservation Management Act MSL mean sea level MT metric tons NAI Normandeau Associates, Inc.

NEFMC New England Fishery Management Council NEFSC Northeast Fishery Science Center NEPA U.S. National Environmental Policy Act of 1969 NextEra NextEra Energy Seabrook, LLC NPDES National Pollutant Discharge Elimination System NMFS National Marine Fisheries Service NOAA National Oceanic and Atmospheric Administration NRC U.S. Nuclear Regulatory Commission PIC proposal for information collection ppt parts per thousand Seabrook Seabrook Station, Unit 1 SEIS Supplemental Environmental Impact Statement USGCRP U.S. Global Change Research Program D-1-iv

Appendix D-1 1 D-1 ESSENTIAL FISH HABITAT ASSESSMENT FOR THE PROPOSED 2 LICENSE RENEWAL OF SEABROOK STATION 3 D-1.1 Introduction 4 In compliance with Section 305(b)(2) of the Magnuson-Stevens Fishery Conservation and 5 Management Act (MSA), as amended by the Sustainable Fisheries Act of 1996 (Public 6 Law 104-267), the U.S. Nuclear Regulatory Commission (NRC) prepared this Essential Fish 7 Habitat (EFH) Assessment for the proposed Federal action: NRCs decision whether or not to 8 renew the operating license for Seabrook Station (Seabrook), Unit 1. Seabrook is located in 9 Rockingham County, NH, on the shore of the Hampton-Seabrook Estuary and the Gulf of 10 Maine.

11 Pursuant to the MSA, NRC staff requested, via letter dated July 16, 2010 (NRC, 2010), that the 12 National Marine Fisheries Service (NMFS) provide information on EFH near the Seabrook site.

13 In their response to NRC, NMFS (2010) indicated that marine waters off Seabrook and the 14 Hampton-Seabrook Estuary have been designated as EFH for 23 Federally-managed species 15 and directed the NRC to prepare an EFH Assessment as part of the EFH consultation process.

16 Accordingly, this EFH Assessment does the following:

17

• describes the proposed action 18

• identifies relevant commercial, Federally managed species within the vicinity of the 19 proposed site 20

• assesses if the proposed action may adversely affect any designated EFH 21

• describes potential measures to avoid, minimize, or offset potential adverse impacts to 22 EFH as a result of the proposed action 23 D-1.2 Description of the Proposed Action 24 The proposed Federal action is NRCs decision of whether or not to renew the operating license 25 for Seabrook for an additional 20 years beyond the original 40-year term of operation.

26 NextEra Energy Seabrook, LLC (NextEra) initiated the proposed Federal action by submitting 27 an application for license renewal of Seabrook, for which the existing license, NPF-86, expires 28 on March 15, 2030. If NRC issues a renewed license for Seabrook, NextEra could continue to 29 operate until the 20-year terms of the renewed license expire in 2050. If the operating license is 30 not renewed, then the facility must shut down on or before the expiration date of the current 31 operating license (March 15, 2030).

32 Pursuant to the NRCs environmental protection regulations in Title 10 of the U.S. Code of 33 Federal Regulations (CFR) Part 51, which implement the U.S. National Environmental Policy 34 Act of 1969 (NEPA), the NRC is publishing a draft supplemental environmental impact 35 statement (SEIS) for Seabrook concurrent with this EFH Assessment. The SEIS is a 36 site-specific supplement to the Generic Environmental Impact Statement [GEIS] for License 37 Renewal of Nuclear Plants, NUREG-1437 (NRC, 1996).

38 NextEra (2010) has proposed no major construction, refurbishment, or replacement activities 39 associated with the proposed Federal action. During the proposed license renewal term, D-1-1

Appendix D-1 1 NextEra would continue to perform site maintenance activities as well as vegetation 2 management on the transmission line right-of-ways that connect Seabrook to the electric grid.

3 D-1.2.1 Site Location and Description 4 Seabrook is located in the Town of Seabrook, Rockingham County, NH, 2 miles (mi) 5 (3.2 kilometers (km)) west of the Atlantic Ocean. Seabrook is approximately 2 mi (3.2 km) north 6 of the Massachusetts state line, 15 mi (24 km) south of the Maine state line, and 10 mi (16 km) 7 south of Portsmouth, NH. Two metropolitan areas lie within 50 mi (80 km) of the site:

8 Manchester, NH (31 mi (50 km) west-northwest) and Boston, MA (41 mi (66 km) 9 south-southwest). Figure D-1-1 and Figure D-1-2 present the 6-mi (10-km) and 50-mi (80-km) 10 area surrounding Seabrook, respectively.

11 The Seabrook site spans 889 acres (ac) (360 hectare (ha)) on a peninsula of land bordered by 12 Browns River on the north, Hunts Island Creek on the south, and estuarine marshlands on the 13 east. Two lots divide the site. The joint owners of Seabrook own Lot 1, which encompasses 14 approximately 109 ac (44 ha). The majority of the operating facility is located on this mostly-15 developed lot. Site structures include the Unit 1 containment building, primary auxiliary building, 16 fuel storage building, waste processing building, control and diesel generator building, turbine 17 building, administration and service building, ocean intake and discharge structures, circulating 18 water pump house, and service water pump house (NextEra, 2010). NextEra originally planned 19 to construct two identical units at the Seabrook site but halted construction on Unit 2 prior to 20 completion and uses the remaining Unit 2 buildings primarily for storage.

21 NextEra owns Lot 2, which is approximately 780 ac (316 ha). Lot 2 is mainly an open tidal 22 marsh area with fabricated linear drainage ditches and tidal creeks, and it is available habitat for 23 wildlife resources (NextEra, 2010). The site boundary is also the exclusion area. Figure D-1-3 24 provides a general layout of the Seabrook site.

25 The Seabrook cooling water comes from an intake structure located 60 feet (ft) (18.3 meters 26 (m)) below mean lower low water in the Gulf of Maine (see Section D-1.2.1.1). The seafloor in 27 this area is relatively flat, with bedrock covered by sand, algae, or sessile invertebrates (NAI, 28 2010). The immediate vicinity surrounding the Seabrook plant is the Hampton-Seabrook 29 Estuary. No intake or discharge structures are located in the estuary. From construction until 30 1994, Seabrook discharged to an onsite settling basin into the Browns River.

31 The Gulf of Maine and Hampton-Seabrook Estuary are complex waterbodies with many 32 individual species performing different roles in the system, and, often, species perform several 33 ecological roles throughout their lifecycles. Major assemblages of organisms within the marine 34 and estuarine communities include plankton, fish, benthic invertebrates, and algae.

35 Section 2.2.6 in the SEIS describes these assemblages and typical habitat types in the 36 nearshore of the Gulf of Maine and within Hampton-Seabrook Estuary.

37 D-1.2.1.1 Cooling and Auxiliary Water Systems 38 Seabrook uses a once-through cooling system that withdraws water from the Gulf of Maine and 39 discharges to the Gulf of Maine through a system of tunnels that have been drilled through 40 ocean bedrock. Unless otherwise cited, the NRC staff drew information about Seabrook's 41 cooling and auxiliary water systems from the National Pollution Discharge Elimination System 42 (NPDES) Permit (EPA, 2002a) and the applicant's environmental report (ER) (NextEra, 2010).

D-1-2

Appendix D-1 Figure D-1-1. Location of Seabrook, 6-mi (10-km) region Source: (NextEra, 2010)

D-1-3

Appendix D-1 Figure D-1-2. Location of Seabrook, 50-mi (80-km) region Source: (NextEra, 2010)

D-1-4

Appendix D-1 Figure D-1-3. Seabrook site boundary and facility layout Source: (NextEra, 2010)

D-1-5

Appendix D-1 1 Water is drawn from the Gulf of Maine through three concrete intake structures that are located 2 at the end of an intake tunnel in approximately 60 ft (18.3 m) of water depth. Each intake shaft 3 extends up from the intake tunnel to above the bedrock, and a velocity cap sits on top 4 (Figure D-1-4). NextEra implemented this structural design to reduce the intake velocity, 5 thereby minimizing fish entrapment. In 1999, NextEra modified the intakes with additional 6 vertical bars to help prevent seals from getting trapped (NMFS, 2002). The NPDES permit 7 limits the intake velocity to 1.0 feet per second (fps) (0.3 meters per second (m/s)) (EPA, 8 2002a).

Figure D-1-4. Intake shafts and caps at Seabrook Source: (ARCADIS et al., 2008) 9 Water flows from the intake structures through a 17,000-ft (5,182-m) intake tunnel that was 10 drilled through the ocean bedrock. The beginning of the intake tunnel is 7,000 ft (2,134 m) from 11 the Hampton beach shoreline. The tunnel descends at a 0.5 percent grade from the bottom of 12 the intake shaft, which is 160 ft (49 m) below the Gulf of Maine, to 240 ft (73 m) below mean sea 13 level (MSL) at Seabrook (Figure D-1-5). Concrete lines the 19-ft (5.8-m) diameter tunnel.

D-1-6

Appendix D-1 Figure D-1-5. Profile of intake tunnel and shafts at Seabrook Source: (ARCADIS et al., 2008) 1 An intake transition structure, which includes three circulating water pumps that transport the 2 water, is located beneath Seabrook (Figure D-1-6). Butterfly valves, 11-ft (3.4-m) in diameter, 3 direct the water flow from the transition structure to the circulating water pump house. The 4 water then passes through three traveling screens with a 3/8-inch (0.95 centimeters (cm)) square 5 mesh (NextEra, 2010a). The traveling screens remove fish, invertebrates, seaweed, and other 6 debris before the water is pumped to the main condensers and the service water system. The 7 ocean debris is disposed as waste; therefore, none is discharged to the Gulf of Maine. The 8 water passes to the condensers to remove heat that is rejected by the turbine cycle and 9 auxiliary system. During normal operations, the circulating water system provides a continuous 10 flow of approximately 390,000 gallons per minute (gpm) (869 cubic feet per second (cfs) or 11 24.6 cubic meters (m3) per second (m3/s)) to the main condenser and 21,000 gpm (47 cfs or 12 1.3 m3/s) to the service water system.

13 Water that has passed through Seabrook discharges to the Gulf of Maine through a 16,500-ft 14 (5,029-m) long discharge tunnel, which has the same diameter, lining, depth, and percent grade 15 as the intake tunnel. The end of the discharge tunnel is 5,000 ft (1,524 m) from the Seabrook 16 beach shoreline. Eleven 70-ft (21-m) deep concrete shafts about 100 ft (30 m) apart discharge 17 the effluent. Each shaft terminates in a pair of nozzles that are pointed up at an angle of about 18 22.5 degrees (NAI, 2001). The nozzles are located 6.5-10 ft (2-3 m) above the seafloor in 19 depths of approximately 49-59 ft (15-18 m) of water (NAI, 2001). To increase the discharge 20 velocity and more quickly diffuse the heated effluent, a double-nozzle fixture tops each shaft.

21 The NPDES permit limits this discharge flow to 720 million gallons per day (mgd) (2.7 million 22 m3/day), and the monthly mean temperature rise may not exceed 5 degrees Fahrenheit (2.6 23 degrees Celsius) at the surface of the receiving water (EPA, 2002a).

24 Barnacles, mussels, and other subtidal fouling organisms can attach to concrete structures and 25 potentially limit water flow through the tunnels. To minimize biofouling within the intake and 26 discharge tunnels, NextEra uses a combination of physical scrubbing and a chlorination system 27 (NextEra, 2010a). Divers physically scrub the intake structures biannually to remove biofouling 28 organismssuch as barnacles, mussels, or other organismsthat attach to hard surfaces to 29 grow. During outages, the inside of the intake structures are physically scrubbed up until the 30 point that chlorine is injected into the tunnels, approximately 6 ft (1.8 m) into the intake shaft. In D-1-7

Appendix D-1 1 addition, NextEra inspects the discharge diffusers during outages. The circulating water pump 2 house, pipes, and condensers are dewatered, inspected, and cleaned as needed 3 (Seabrook, 2008). NextEra injects chlorine and other water treatment chemicals in accordance 4 with NPDES permit limits (EPA, 2002a).

Figure D-1-6. Circulating water pumphouse at Seabrook Source: (ARCADIS et al., 2008) 5 As described above, the Gulf of Maine provides water for both the circulating water system and 6 the service water system. Water flows from the intake structures to the service water pump 7 house, which is separated from the circulating water system portion of the building by a seismic 8 reinforced concrete wall. In the event that the regular supply of cooling water from the service 9 water pump house is unavailable, NextEra would use a standby mechanical draft evaporative 10 cooling tower (service water tower) and 7-day makeup water reservoir. This makeup water 11 reservoir is from the Gulf of Maine and stored in the service water tower. If this makeup 12 reservoir is unavailable, or additional water is required, NextEra would access emergency 13 makeup water from the domestic water supply system or from the Browns River via a portable 14 pump (FPLE, 2008).

15 Sections 2.1.1-2.1.5 of the SEIS provide additional information regarding the reactor and 16 containment systems, other systems at Seabrook, and plant operations. Sections 2.1.7 and 17 2.2.5 provide additional information on Seabrooks surface water use and a description of the 18 NDPES permit.

19 D-1.3 Essential Fish Habitat Species Near the Site and Potential Adverse Effects 20 D-1.3.1 Essential Fish Habitat Species Identified for Analysis 21 The waters and substrate necessary for spawning, breeding, feeding, or growth to maturity are 22 considered EFH (16 U.S.C. 1802(10)). The portion of the Gulf of Maine and Hampton-Seabrook D-1-8

Appendix D-1 1 Estuary adjacent to Seabrook, and its intake and discharge structures, contains designated EFH 2 for several fish species and life stages.

3 In its Guide to Essential Fish Habitat Designations in the Northeastern United States, NMFS 4 (2011a) identifies EFH by 10-minute squares of latitude and longitude as well as by major 5 estuary, bay, or river for estuarine waters outside of the 10-minute square grid. The waters near 6 Seabrook are within the Gulf of Maine EFH Designation that extends from Salisbury, MA, north 7 to Rye, NH and includes Hampton Harbor, Hampton beach, and Seabrook beach. The 23 8 species with designated EFH in this area appear in Table D-1-1.

9 Table D-1-1. Species of fish with designated EFH in the vicinity of Seabrook Species Eggs Larvae Juveniles Adults American plaice (Hippoglossoides platessoides) x x Atlantic butterfish (Peprilus triacanthus) x x x x Atlantic cod (Gadus morhua) x x x x Atlantic halibut (Hippoglossus hippoglossus) x x x x Atlantic herring (Clupea harengus) x x Atlantic mackerel (Scomber scombrus) x x x x Atlantic sea scallop (Placopecten magellanicus) x x x x Bluefin tuna (Thunnus thynnus) x Haddock (Melanogrammus aeglefinus) x Longfin inshore squid (Loligo pealei) x x Monkfish/Goosefish (Lophius americanus) x x x x Northern shortfin squid (Illex illecebrosus) x x Ocean pout (Macrozoarces americanus) x x x x Pollock (Pollachius virens) x Redfish (Sebastes fasciatus) x x x Red hake (Urophycis chuss) x x x x Scup (Stenotomus chrysops) x x Summer flounder (Paralicthys dentatus) x Surf clam (Spisula solidissima) x x Whiting/Silver hake (Merluccius bilinearis) x x x x Windowpane flounder (Scopthalmus aquosus) x x Winter flounder (Pleuronectes americanus) x x x x Yellowtail flounder (Pleuronectes ferruginea) x x Source: (NMFS, 2011b) 10 Seabrook has monitored fish and shellfish eggs, larvae, juveniles, and adults since the 11 mid-1970s. In addition, Seabrook regularly records annual estimates of entrainment and D-1-9

Appendix D-1 1 impingement. Table D-1-2 presents a summary of the occurrence of EFH species within 2 Seabrooks monitoring, entrainment, and impingement studies.

3 The NRC staff compared monitoring, entrainment, and impingement data with each of the EFH 4 species listed in Table D-1-2. Seabrook regularly observed most EFH species within 5 monitoring, entrainment, or impingement studies. However, Atlantic halibut, redfish, bluefin 6 tuna, northern shortfin squid, and longfin inshore squid were rarely or occasionally identified 7 during monitoring studies and were not entrained or impinged from 1990-2009. These fives 8 species are analyzed in Section D-1.3.3.19 of this assessment. All other EFH species are 9 analyzed in detail in Sections D-1.3.3.1-D-1.3.3.18 of this assessment.

10 D-1.3.2 Potential Adverse Effects to Essential Fish Habitat 11 The provisions of the regulations implementing the MSA define an adverse effect to EFH as 12 the following (50 CFR 600.810):

13 Adverse effect means any impact that reduces quality and/or quantity of EFH.

14 Adverse effects may include direct or indirect physical, chemical, or biological 15 alterations of the waters or substrate and loss of, or injury to, benthic organisms, 16 prey species and their habitat, and other ecosystem components, if such 17 modifications reduce the quality and/or quantity of EFH. Adverse effects to EFH 18 may result from actions occurring within EFH or outside of EFH and may include 19 site-specific or habitat-wide impacts, including individual, cumulative, or 20 synergistic consequences of actions.

21 For purposes of conducting NEPA reviews, the NRC staff published the GEIS (NRC, 1996),

22 which identifies 13 impacts to aquatic resources as either Category 1 or Category 2.

23 Category 1 issues are generic in that they are similar at all nuclear plants and have one impact 24 level (SMALL, MODERATE, or LARGE) for all nuclear plants. Mitigation measures for 25 Category 1 issues are not likely to be sufficiently beneficial to warrant implementation.

26 Category 2 issues vary from site to site and must be evaluated on a site-specific basis.

27 Table D-1-3 lists the aquatic resource issues as identified in the GEIS.

28 The GEIS classifies all impact levels for aquatic resources as SMALL except impingement, 29 entrainment, and heat shock. NRC defines SMALL as having environmental effects are not 30 detectable or are so minor that they will neither destabilize nor noticeably alter any important 31 attribute of the resource (10 CFR 51, App. B, Table B-1). The NRC staff believes that stressors 32 with SMALL levels of impact for the purposes of implementing NEPA would likely not 33 adversely affect EFH. Therefore, this EFH Assessment will focus on the potential adverse 34 effects of impingement, entrainment, and heat shock on EFH. Impingement occurs when 35 aquatic organisms are pinned against intake screens or other parts of the cooling water system 36 intake structure. Entrainment occurs when aquatic organisms (usually eggs, larvae, and other 37 small organisms) are drawn into the cooling water system and are subjected the thermal, 38 physical, and chemical stress. Heat shock is acute thermal stress caused by exposure to a 39 sudden elevation of water temperature that adversely affects the metabolism and behavior of 40 fish and other aquatic organisms. In addition to heat shock, increased water temperatures at 41 the discharge can also reduce the available habitat for fish species if the discharged water is 42 higher than the environmental preferences of a particular species. This issue will be discussed 43 together with heat shock.

44 D-1-10

Appendix D-1 1

2 Table D-1-2. Relative commonness of EFH species in Seabrook monitoring, entrainment, and impingement studies Eggs Larvae Juveniles and Adults Species Plankton Entrainment Plankton Entrainment Trawl Gill net Seine Impingement monitoring studies monitoring studies monitoring monitoring monitoring studies American plaice Common(a) Occasional Common Occasional(b) Occasional Rare(c)

Atlantic butterfish Occasional Rare Occasional Rare Rare Occasional Rare Rare (e)

Atlantic cod Common Common Common Rare Common Occasional Rare Rare Atlantic halibut Rare Atlantic herring Common Occasional Occasional Abundant Occasional Common Atlantic mackerel Abundant(d) Abundant Abundant Rare Rare Common Rare Rare Atlantic sea scallop Rare Atlantic surf clam Rare D-1-11 Bluefin tuna Haddock (e) Common Rare Occasional Rare Common Rare Rare Monkfish/Goosefish Rare Rare Occasional Rare Occasional Rare Rare Ocean pout Occasional Rare Common Rare Rare Pollock Common Rare Common Rare Common Common Occasional Common (e)

Redfish Occasional Red hake (e) Common Common Common Occasional Abundant Occasional Common Common Scup Rare Occasional Rare Rare Summer flounder Rare Rare Rare Rare Whiting/Silver hake Common Common Common Occasional Common Common Rare Rare Windowpane flounder Common Occasional Common Rare Common Rare Occasional Common Winter flounder Rare Common Occasional Common Occasional Common Common D-1-11

Appendix D-1 Eggs Larvae Juveniles and Adults Species Plankton Entrainment Plankton Entrainment Trawl Gill net Seine Impingement monitoring studies monitoring studies monitoring monitoring monitoring studies (e)

Yellowtail flounder Abundant Occasional Common Rare Abundant Rare Rare Common (a)

Common: Occurring in >10% of samples but <10% of total catch; 5-10% of entrainment samples averaged over all years (b)

Occasional: Occurring in <10%-1% of samples; 1-5% of entrainment samples averaged over all years (c)

Rare: Occurring in <1% of samples; <1% of entrainment samples averaged over all years (d)

Abundant: >10% of total catch or entrainment over all years (e)

During monitoring surveys, NAI (2010) combined certain groups of species if eggs were morphologically similar and spawning periods overlapped during the sampling period. In such cases, the estimate for the entire group of species appears in the table above. Groups of species include Atlantic cod/ haddock/witch flounder, cunner/yellowtail founder, red hake/white hake/spotted hake, and golden redfish/deepwater redfish/and Acadian redfish. For egg entrainment estimates of these groups of species, NextEra (2010b) estimated single species entrainment rates by applying the ratio of larval species to the egg species groups Blank cells indicate the NAI (2010) did not identify the species within monitoring or entrainment studies.

Sources: (NAI, 2010; NextEra, 2010a) 1 D-1-12 D-1-12

Appendix D-1 1 Table D-1-3. Aquatic resource issues identified in the GEIS Issues Category Impact level For all plants Accumulation of contaminants in sediments or biota 1 SMALL Entrainment of phytoplankton & zooplankton 1 SMALL Cold shock 1 SMALL Thermal plume barrier to migrating fish 1 SMALL Distribution of aquatic organisms 1 SMALL Premature emergence of aquatic insects 1 SMALL Gas supersaturation (gas bubble disease) 1 SMALL Low dissolved oxygen in the discharge 1 SMALL Losses from parasitism, predation, & disease among 1 SMALL organisms exposed to sublethal stresses Stimulation of nuisance organisms 1 SMALL For plants with once-through heat dissipation systems Impingement of fish & shellfish 2 SMALL, MODERATE, or LARGE Entrainment of fish & shellfish in early life stages 2 SMALL, MODERATE, or LARGE Heat shock 2 SMALL, MODERATE, or LARGE Source: (NRC, 1996) 2 In addition to impingement, entrainment, and heat shock (or thermal impacts), the NRC staff will 3 assess the impacts to EFH species food (forage species) and loss of habitat-forming species 4 (such as sessile invertebrates and algae). Information on these areas that is relevant to all EFH 5 species is in Section D-1.3.2.1. In addition, Section D-1.3.2.2 presents NextEra monitoring data 6 of selected groups prior to and during operations at sampling sites near the intake and 7 discharge structures (nearfield sampling sites) and at sampling sites 3-4 mi (5-8 km) away 8 (farfield sampling sites). Monitoring data may indicate whether the combined impacts (or 9 cumulative impacts) from Seabrook operation has resulted in the decline of forage species, 10 habitat-forming species, or EFH species due to a decline in habitat quantity or quality. The NRC 11 staff's conclusions and information specific to each EFH species is in Sections D-1.3.3.1-12 D-1.3.3.19. Section D-1.4 provides an analysis of cumulative impacts to EFH species or their 13 habitat resulting from the past, present, and reasonably foreseeable future projects in the 14 vicinity of Seabrook.

15 D-1.3.2.1 Information Related to Potential Adverse Impact on All Essential Fish 16 Habitat Species 17 The section below provides information regarding potential adverse impacts to EFH that is 18 relevant for the assessment of all 23 EFH species that may occur within the vicinity of 19 Seabrook.

20 Entrainment and Impingement. Entrainment and impingement study results illustrate one type 21 of operational impact on each species habitat. Because the intake water is EFH, the ratio of D-1-13

Appendix D-1 1 specimens from a species impinged or entrained at Seabrook to the total number of impinged or 2 entrained organisms provides some indication of how great the impact from the cooling system 3 will be on the corresponding EFH. The NRC staff obtained data on fish entrainment and 4 impingement from Seabrooks Annual Biological Monitoring Reports, which summarize 5 entrainment data from 1990-2009 and impingement data from 1994-2009 (NAI, 2010).

6 NextEra conducted entrainment studies four times per month (NAI, 2010). For fish eggs and 7 larvae prior to 1998, NextEra collected three replicate samples using 0.02-in. (0.505-mm) mesh 8 nets. Since 1998, NextEra collected samples using 0.01-in. (0.333-mm) mesh sizes throughout 9 a 24-hour period. NextEra estimated entrainment rates by multiplying the density of entrained 10 eggs or larvae within a sample by the volume of water pumped through the plant within the 11 sample period (FPLE, 2008; NAI, 2010). Entrainment rates for commonly entrained species, 12 EFH species, and common forage species are presented in Table D-1-4 for egg entrainment 13 and Table D-1-5 for larvae entrainment.

14 NextEra conducted impingement monitoring once or twice per week by cleaning traveling 15 screens and sorting fish and other debris (NAI, 2010). Prior to 1998, NextEra did not sort some 16 collections, and impingement estimates are based on the volume of debris (NAI, 2010).

17 Beginning in 1998, Seabrook staff sorted all collections and identified all impinged fish by 18 species. Beginning in April 2002, NextEra collected 2 standardized 24-hour samples per week 19 and multiplied by 7 to estimate weekly impingement. Table D-1-6 shows impingement rates for 20 commonly impinged species, EFH species, and common forage species.

21 NAI (2010) reported impingement estimates from 1994-2009. Prior to October 1994, NextEra 22 determined that some small, impinged fish had been overlooked during separation procedures.

23 NextEra enhanced the Impingement Monitoring Program in the end of 1994 to remedy this issue 24 (NextEra, 2010a).

25 NextEra also conducted entrainment studies for bivalve larvae (NAI, 2010). In these studies, 26 NextEra collected three replicates per sampling date using a 0.003-in. (0.076-mm) mesh.

27 Table D-1-7 describes entrainment rates for bivalve larvae.

28 Thermal Impacts. Heat shock can injure or kill fish. In addition, aquatic species, including EFH 29 species or prey of EFH species, may largely avoid effluents due to high velocities, elevated 30 temperatures, and turbulence. Seabrooks discharge to the Gulf of Maine is permitted under its 31 NPDES permit (EPA, 2002a), issued April 1, 2002. The permit allows discharge of 720 mgd 32 (2.7 million m3/day) on both an average monthly and maximum daily basis. The permit also 33 limits the rise in monthly mean temperature to 5 degrees Fahrenheit in the near field jet mixing 34 region, or within waters less than 3.3 ft (1 m) from the surface. An EPA online database 35 indicated that Seabrook has had no Clean Water Act (CWA) formal enforcement actions or 36 violations related to discharge temperature in the last 5 years (EPA, 2010). EPAs Regional 37 Administrator determined that NextEras NPDES permit provides a Section 316(a) variance that 38 satisfies thermal requirements and that will ensure the protection and propagation of a 39 balanced indigenous community of fish, shellfish, and wildlife in and on Hampton Harbor and 40 the near shore Atlantic Ocean (EPA, 2002a).

41 D-1-14

Appendix D-1 1 Table D-1-4. Number of fish eggs entrained (in millions) for most common egg taxa entrained and for EFH species Taxon(a) 1990(b) 1991(c) 1992(d) 1993(d) 1994(e) 1995(f) 1996 1997 1998 1999 2000 2001 American plaice 2.6 21.0 52.3 19.5 0.4 14.8 78.2 15.6 13.7 24.8 16.7 26.8 Atlantic cod 20.8 74.5 32.0 50.3 0.2 37.0 22.4 6.4 84.3 48.6 30.7 32.1 Atlantic mackerel 518.8 673.1 456.3 112.9 0.0 74.5 305.1 23.1 39.3 44.6 266.9 330.4 Butterfish 0 0 0 0 0 0 0.1 0 0 <0.1 0 0 Cunner 489.3 147.2 0 58.4 0 18.2 93.9 221.5 63.6 220.3 1,206.7 239.6 Fourbeard rockling 108.8 39.5 51.4 32.7 0.2 27.5 38.7 46.6 33.9 27.4 63.6 47.1 Haddock 0.0 0.0 7.4 0.0 <0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Hake 50.1 2.6 0 1.6 0.6 29.3 213.2 71.8 7.5 6.2 295.2 4.4 Monkfish/Goosefish 0 0 0 0 0 0 0 0 0.9 0 0.9 0 Pollock 0 1.0 0.4 0.2 0.1 0.4 0.4 0.2 2.9 0.2 <0.1 0.3 Whiting/Silver hake 11.4 0.0 0.1 0.4 0.4 22.5 73.6 271.1 18.6 139.9 90.4 48.9 D-1-15 Windowpane 36.4 19.9 22.5 29.1 0.1 17.4 44.2 28.5 17.9 43.2 95.1 33.4 Winter flounder 0 0 0 0 0 0 0 0 0 0 0.3 0 Yellowtail flounder 1.2 569.2 198.6 0 0 0.6 17.9 0.5 1.9 33.8 2.8 8.4 Total (All Species) 1,247.7 1,551.3 822.6 315.6 4.8 255.9 926.4 692.7 286.7 593.9 2,104.4 775.1 (a)

Normandeau Associates, Inc. (NAI) (2010) combined certain groups of species if eggs were morphologically similar and spawning periods overlapped during the sampling period. Groups of species include Atlantic cod/haddock, cunner/yellowtail founder, and hake/fourbeard rockling. NextEra (2010a) estimated entrainment rates for each species by applying the ratio of larval species to the egg species groups.

(b)

NextEra sampled three months, August-October.

(c)

NextEra sampled eight months, January-July, December.

(d)

NextEra sampled eight months, January-August.

(e)

NextEra sampled seven months, January-March, September-December.

(f)

NextEra sampled 12 months per year.

Source: (NAI, 2010; NextEra, 2010a) 2 D-1-15

Appendix D-1 1 Table D-1-4. Number of fish eggs entrained (in millions) for most common egg taxa entrained and for EFH species (cont.)

Taxon 2002 2003 2004 2005 2006 2007 2008 2009 Average Percentage American plaice 22.4 37.8 33.4 11.7 5.3 35.8 48.0 36.7 25.9 2.9%

Atlantic cod 77.8 15.5 9.3 16.0 15.7 15.1 48.0 15.4 32.6 3.6%

Atlantic mackerel 56.7 26.4 70.1 37.7 475.6 153.6 82.4 83.5 191.5 21.3%

Butterfish 0 0 0 0.4 0 0 0 0 <0.1 <0.1%

Cunner 1,395.7 143.9 518.1 251.2 489.4 295.0 444.5 1,451.2 387.4 43.0%

Fourbeard rockling 61.4 44.1 38.2 68.8 36.6 78.2 61.7 123.8 51.5 5.7%

Haddock 0 0 0 0.7 0 0 0 0 0.4 <0.1%

Hake 79.7 5.2 5.7 2.8 8.1 15.6 21.7 92.1 45.7 5.1%

Monkfish/Goosefish 0 0 0.1 0.1 0.1 0 0 0 0.1 <0.1%

Pollock 0.6 1.0 0.9 1.0 4.1 8.5 5.0 0.2 1.4 0.2%

Whiting/Silver hake 341.4 235.6 19.8 30.7 9.4 60.8 50.9 196.2 81.1 9.0%

Windowpane 39.1 15.5 18.2 26.2 24.7 34.7 25.9 61.8 31.7 3.5%

D-1-16 Winter flounder 0 0.3 0 0 0 0.2 1.1 <0.1 <0.1 <0.1%

Yellowtail flounder 3.9 0 0.1 5.0 1.1 7.8 0 4.1 42.8 4.8%

Total (All Species) 2,086.8 529.4 723.7 454.4 1,075.4 714.7 790.6 2,072.5 901.2 100%

(a)

Normandeau Associates, Inc. (NAI) (2010) combined certain groups of species if eggs were morphologically similar and spawning periods overlapped during the sampling period. Groups of species include Atlantic cod/haddock, cunner/yellowtail founder, and hake/fourbeard rockling. NextEra (2010a) estimated entrainment rates for each species by applying the ratio of larval species to the egg species groups.

(b)

NextEra sampled three months, August-October.

(c)

NextEra sampled eight months, January-July, December.

(d)

NextEra sampled eight months, January-August.

(e)

NextEra sampled seven months, January-March, September-December.

(f)

In 1995-2009, NextEra sampled 12 months per year.

Source: (NAI, 2010; NextEra, 2010a) 2 D-1-16

Appendix D-1 1 Table D-1-5. Number of fish larvae entrained (in millions) for the most common larval taxa entrained and for EFH species Taxon 1990(a) 1991(b) 1992(c) 1993(d) 1994(e) 1995 1996 1997 1998 1999 2000 2001 American plaice 0.4 1.0 0.8 0.7 0 7.9 8.1 7.0 2.9 4.9 1.6 8.7 American sand lance 0 37.3 18.1 12.0 8.3 9.5 14.0 10.1 10.7 7.8 1.0 5.3 Atlantic butterfish 0 0 0 0 0 0 0 0.1 0 0 0 0 Atlantic cod 0.7 1.5 0.4 0.1 0 2.3 0.3 0.7 2.2 1.0 0.4 2.5 Atlantic herring 0.7 0.5 4.9 9.6 0.1 11.2 4.3 2.1 9.5 8.6 0.2 15.2 Atlantic mackerel 0.2 4.7 0 0 0 0 0.1 0.4 0 0.1 0.3 0.1 Cunner 42.7 <0.1 0 4.7 0.1 4.4 9.2 203.8 8.4 4.7 111.0 13.6 Fourbeard rockling 37.9 0.5 0.1 2.2 0.0 3.9 11.7 22.4 13.1 21.0 8.2 19.6 Grubby 0 22.4 18.9 13.8 4.9 17.4 18.6 12.8 17.3 6.4 2.2 12.4 Haddock 0 0 0.1 0 0 0 0 0 0 0 0 0 Hake 4.8 0 0 0.1 0 0.7 12.3 1.7 <0.1 0.1 29.8 0 Monkfish/Goosefish 0.1 0 0 0 0 0 0 0 0 0 2 0 Ocean pout 0 0 0 0 0 0 0 0 0 0 0 0 Pollock 0.2 0 0.1 0 0 0 0 0 <0.1 0 0 0 Summer flounder 0 0 0 0 0 0 0 0 <0.1 0 0 0 D-1-17 Whiting/Silver hake 7.7 0 0 0.1 0 0.9 16.9 69.0 0.2 0.4 33.2 0.6 Windowpane 3.8 <0.1 0.1 0.1 <0.1 2.0 2.0 5.6 1.4 3.7 2.3 1.3 Winter flounder 3.2 9.0 6.2 2.9 0 8.0 10.3 2.2 4.7 7.4 14.3 14.3 Yellowtail flounder 0.1 0.3 0.1 0 0 0.1 1.6 0.5 0.3 0.8 0.3 0.5 Total (All Species) 121.5 153.8 133.1 126.1 31.2 145.3 215.7 373.4 134.1 171.8 261.2 124.3 (a)

NextEra sampled June-October.

(b)

NextEra sampled the last week in April through the first week in August.

(c)

NextEra sampled the third week in April through the third week in June.

(d)

Unless otherwise denoted, NextEra sampled the third week in April through the fourth week in October.

(e)

NextEra did not conduct bivalve larvae entrainment studies.

(f)

NextEra sampled the fourth week in April through the fourth week in October.

(g)

NextEra sampled the fourth week in April through the fourth week in September.

Source: (NAI, 2010) 2 D-1-17

Appendix D-1 1 Table D-1-5. Number of fish larvae entrained (in millions) for the most common larval taxa entrained and for EFH species 2 (cont.)

Taxon 2002 2003 2004 2005(f) 2006(g) 2007 2008 2009 Average Percentage American plaice 11.3 9.1 2.6 1.4 0.6 2.6 3.5 11.5 4.3 1.6%

American sand lance 10.5 27.1 107.1 28.3 14.1 36.6 71.2 128.6 27.9 10.3%

Atlantic butterfish 0 0 0 0 0 0 0 0 <0.1 <0.1%

Atlantic cod 34.6 2.5 0.5 1.6 0.3 1.6 1.4 1.4 3.0 1.0%

Atlantic herring 11.7 15.3 8.8 9.7 12.8 11.5 28.2 27.7 9.6 3.6%

Atlantic mackerel 0.4 0 20.2 0.1 0.5 0 <0.1 25.7 2.6 1.0%

Cunner 391.1 22.5 451.2 2.5 8.8 97.7 86.2 105.7 78.4 29.1%

Fourbeard rockling 176.4 19.3 61.4 2.0 4.9 16.4 11.9 20.3 22.7 8.4%

Grubby 6.6 27.5 51.8 7.8 9.3 15.4 8.3 31.6 15.3 5.7%

Haddock 0 0 0 0.1 0 0 0 0 <0.1 <0.1%

Hake 0.3 0.1 1.0 0 0.2 0 0.2 4.0 2.8 1.0%

Monkfish/Goosefish 0 0 0.1 0 0 0 0 <0.1 0.1 <0.1%

Ocean pout 0 <0.1 0 0 0 0 0 0 <0.1 <0.1%

Pollock <0.1 0.6 0.1 0.1 0.8 0.8 0.3 0.3 0.2 0.1%

Summer flounder 0 <0.1 0 0 0 <0.1 0 0 <0.1 <0.1%

D-1-18 Whiting/Silver hake 5.9 0.5 0.2 0 0.1 0 17.9 8.2 8.1 3.0%

Windowpane 6.5 0.5 0.4 0.5 0.5 2.6 11.4 1.9 2.3 0.9%

Winter flounder 4.5 20.0 34.8 4.9 7.2 15.8 0.1 15.2 9.2 3.4%

Yellowtail flounder 0.9 0 0.1 <0.1 <0.1 2.7 0 0.3 0.4 0.2%

Total (All Species) 724.4 268.5 958.5 167.0 123.2 297.2 333.7 523.2 269.4 100%

(a)

NextEra sampled June-October.

(b)

NextEra sampled the last week in April through the first week in August.

(c)

NextEra sampled the third week in April through the third week in June.

(d)

Unless otherwise denoted, NextEra sampled the third week in April through the fourth week in October.

(e)

NextEra did not conduct bivalve larvae entrainment studies.

(f)

NextEra sampled the fourth week in April through the fourth week in October.

(g)

NextEra sampled the fourth week in April through the fourth week in September.

Source: (NAI, 2010) 3 D-1-18

Appendix D-1 1 Table D-1-6. Number of impinged fish for the most common taxa impinged and for EFH species Species 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Alewife 0 8 1,753 2,797 14 16 4 35 1 9 212 87 American plaice 0 0 0 0 0 2 0 0 0 0 0 3 American sand lance 1,215 1,324 823 182 708 234 423 114 245 3,396 665 1,029 Atlantic butterfish 3 14 3 223 9 5 1 28 1,170 4 35 54 Atlantic herring 0 0 485 350 582 20 5 11 159 198 118 93 Atlantic mackerel 0 0 1 0 0 0 0 1 0 0 4 4 Atlantic menhaden 0 7 97 0 1 957 142 19 1,022 7 361 7,226 Atlantic silverside 5,348 1,621 1,119 210 834 1,335 31 282 1,410 20,507 877 2,717 Atlantic cod 58 119 94 69 38 66 29 30 199 3,091 467 454 Cunner 32 342 1,121 233 309 255 324 341 291 554 625 893 Grubby 2,678 2,415 1,457 430 3,269 3,953 1,174 549 1,089 2,523 676 531 Haddock 0 1 397 0 1 3 2 1 0 0 0 7 Hakes 2,822 2,188 156 122 4 68 113 523 1,813 166 35 11 Monkfish/Goosefish 3 13 0 0 7 17 15 59 18 10 0 8 Northern pipefish 188 579 1,200 243 268 748 370 714 936 2,716 1,413 1,724 Ocean pout 0 6 1 0 7 3 2 21 1 13 3 3 D-1-19 Pollock 1,681 899 1,835 379 536 11,392 534 405 719 499 80 218 Rainbow smelt 545 213 4,489 365 535 100 8 65 323 3,531 2,085 3,314 Red hake 1 16 1,478 371 903 1,120 112 155 52 271 892 821 Rock gunnel 494 1,298 1,122 459 2,929 2,308 1,514 2,251 2,066 6,274 4,137 1,752 Sea raven 78 125 1,015 223 137 132 206 271 166 217 129 221 Scup 0 14 9 0 3 1 0 3 11 11 0 21 Shorthorn sculpin 14 156 282 123 190 296 923 621 642 7,450 876 2,214 Snailfishes 180 165 1,013 351 856 2,356 690 334 616 451 185 442 Summer flounder 3 0 0 0 0 0 0 0 0 0 0 0 Threespine stickleback 67 155 320 174 773 506 10 280 34 1,549 130 307 Whiting/Silver hake 0 49 58 108 13 100 41 5 1,177 22 212 306 Windowpane 980 943 1,164 1,688 772 692 251 161 2,242 4,749 936 2,034 Winter flounder 1,435 1,171 3,231 468 1,143 3,642 102 777 897 10,491 783 1,875 Yellowtail flounder 0 1,149 4 23 11 97 0 8 5 0 0 0 Total (All taxa) 19,212 15,940 26,825 10,648 15,198 31,241 7,281 8,577 18,413 71,946 16,696 29,368 Source: (NAI, 2010) 2 D-1-19

Appendix D-1 1 Table D-1-6. Number of impinged fish for the most common taxa impinged and for EFH species (cont.)

Species 2006 2007 2008 2009 Total Percent of Total Annual Average Alewife 255 244 41 0 5,476 1.6% 342 American plaice 0 0 7 0 12 0.0% 0.75 American sand lance 213 2,073 758 796 14,198 4.3% 887 Atlantic Butterfish 44 199 7 29 1,828 0.5% 114 Atlantic herring 189 260 27 490 2,987 0.9% 187 Atlantic mackerel 0 0 0 0 10 0.003% 1 Atlantic menhaden 94 160 67 39 10,199 3.1% 637 Atlantic silverside 788 639 247 525 38,490 11.5% 2,406 Atlantic cod 113 178 73 147 5,225 1.6% 327 Cunner 687 922 731 837 8,497 2.5% 531 Grubby 235 869 3,919 521 26,288 7.9% 1,643 Haddock 3 25 0 15 455 0.1% 28 Hakes 6 1,184 3,216 1,427 13,854 4.1% 866 Monkfish/Goosefish 0 11 0 0 161 0.0% 10 Northern pipefish 1,288 2,374 1,082 698 16,541 5.0% 1,034 Ocean pout 6 3 0 0 69 0.0% 4 Pollock 73 340 123 657 20,370 6.1% 1,273 D-1-20 Rainbow smelt 878 572 421 43 17,487 5.2% 1,093 Red hake 546 1,389 14 0 8,141 2.4% 509 Rock gunnel 3,782 3,174 937 701 35,198 10.5% 2,200 Sea raven 138 164 138 79 3,439 1.0% 215 Scup 4 8 13 15 113 0.0% 7 Shorthorn sculpin 1,258 465 1,515 266 17,291 5.2% 1,081 Snailfishes 330 76 233 85 8,363 2.5% 523 Summer flounder 4 0 0 0 7 0.0% 0 Threespine stickleback 139 193 80 118 4,835 1.4% 302 Whiting/Silver hake 31 21 204 325 2,672 0.8% 167 Windowpane 572 1,502 1,640 427 20,753 6.2% 1,297 Winter flounder 767 3,949 1,920 655 33,306 10.0% 2,082 Yellowtail flounder 10 11 3 0 1,321 0.4% 83 Total (All taxa) 12,955 22,472 17,935 9,304 334,011 100.0% 20,876 Source: (NAI, 2010) 2 D-1-20

Appendix D-1 1 Table D-1-7. Number of bivalve larvae entrained (x 109)

Taxon 1990(a) 1991(b) 1992(c) 1993(d) 1995 1996 1997 1998 1999 2000 2001 2002 2003 Prickly jingle 1,691 250.8 6.9 3,923 8,906 23,522 2,883 3,827 36,495 7542 4,129 8,204 3,218.1 Bivalvia mussles 181.7 38.1 14.5 334.5 797.1 671.4 71.1 64.5 651.3 228.6 483 194.2 73.7 Rock borer 876.6 421.3 189.8 2,406 2,598 4,670 923.7 609.7 4,417 1,921 1,575 567.3 1,203.9 Northern horsemussel 909.7 160.2 0.3 1,284 546.4 5,145 614.7 241.7 2,376 2,521 251.6 776.4 240.8 Soft shell clam 8.1 0.6 0.2 22.5 4.3 33.2 53.7 11.4 45.7 23.9 26.4 60.2 5.1 Truncate softshell clam 249.2 6.5 1.1 2.1 27.6 123 0.8 8.3 66 34.9 26.3 1.9 13.8 Blue mussels 3,991 1,688 121.9 10,051 13,231 17,932 1745 1,493 22,374 10,255 9621 3,318 2,199 Atlantic Sea scallop 0.7 0.7 0.1 16.9 6.2 31 0.8 0.8 11.5 9.9 8.5 0.8 0 Solenidae clams 61.1 0 75.7 102.5 1092 241.9 49.5 20.9 773.2 150.4 922.9 150.8 85.5 Atlantic Surf clam 69 4.4 0 48.5 112.5 171.1 22.5 14.8 175.5 33.6 50.8 44.2 3.1 Shipworm 0.01 15.9 0 0 4.8 7.4 1.7 0.8 29.9 1.5 0.3 2.3 0.1 Total (All taxon) 8,039 2,586 410 18,190 27,327 52,547 6,366 6,293 67,415 22,721 17,095 13,320 7,043 (a)

D-1-21 NextEra sampled June-October.

(b)

NextEra sampled the last week in April through the first week in August.

(c)

NextEra sampled the third week in April through the third week in June.

(d)

In 1994, NextEra did not conduct bivalve larvae entrainment studies. Unless otherwise denoted for all other years,, NextEra sampled the third week in April through the fourth week in October.

(e)

NextEra sampled the fourth week in April through the fourth week in October.

(f)

NextEra sampled the fourth week in April through the fourth week in September.Source: (NAI, 2010) 2 D-1-21

Appendix D-1 1 Table D-1-7. Number of bivalve larvae entrained (x 109) (cont.)

Taxon 2004 2005(e) 2006(f) 2007 2008 2009 Average Prickly jingle 2,595 1,217 3,966 3,950 18,452 27,733 8,553.2 Bivalvia mussles 89.6 40.4 73.9 46.2 411.8 74.3 238.94 Rock borer 1,024 352.9 604.6 650.7 3,137 2,548 1,615.5 Northern horsemussel 843.2 292.9 715.1 172.5 2,270 1421 1,093.8 Soft shell clam 15.1 9.2 11.1 4.7 45.8 31.8 21.737 Truncate softshell clam 5.2 2.3 0.6 3 6.4 4.8 30.726 Blue mussels 1,526 921.5 1,351 834.4 2,700 3,974 5,754 Atlantic Sea scallop 0.7 0.1 0 0.1 0.3 1.2 4.7526 Solenidae clams 113.4 57.9 65.2 156.1 85.1 162.4 229.83 Atlantic Surf clam 10 14.5 20 2.8 100.7 31.5 48.921 Shipworm 0.6 0.3 0.8 0 1.8 2.3 3.7111 Total (All taxon) 6,223 2,909 6,809 5,820 27,211 35,983 17,595 (a)

NextEra sampled June-October.

D-1-22 (b)

NextEra sampled the last week in April through the first week in August.

(c)

NextEra sampled the third week in April through the third week in June.

(d)

In 1994, NextEra did not conduct bivalve larvae entrainment studies. In all other years, NextEra sampled the third week in April through the fourth week in October.

(e)

NextEra sampled the fourth week in April through the fourth week in October.

(f)

NextEra sampled the fourth week in April through the fourth week in September.

Source: (NAI, 2010) 2 D-1-22

Appendix D-1 1 Padmanabhan and Hecker (1991) conducted a thermal plume modeling and field verification 2 study. This study estimated a temperature rise of approximately 36 to 39 degrees Fahrenheit 3 (20 to 22 degrees Celsius) at the diffusers (Padmanabhan and Hecker, 1991). Field and 4 modeling data indicated that the water rose relatively straight to the surface and spread out 5 within 10-16 ft (3-5 m) of the ocean surface. At the surface, Padmanabhan and Hecker (1991) 6 observed a temperature rise of 3 degrees Fahrenheit (1.7 degrees Celsius) or more in a 32-ac 7 (12.9-ha) area surrounding the discharge. Padmanabhan and Hecker (1991) did not observe 8 significant increases in surface temperature 1,640 ft (500 m) to the northwest of the discharge 9 structure.

10 NextEra has conducted monitoring of water temperature at bottom and surface waters near the 11 discharge structure during operations (NAI, 2001; NAI, 2010). NextEra monitored bottom water 12 temperature at a site 656 ft (200 m) from the discharge and at a site 3-4 nautical mi (5-8 km) 13 from the discharge from 1989-1999 (NAI, 2001). NextEra observed a significant difference in 14 the monthly mean bottom water temperature between the two sites. The mean difference was 15 less than 0.9 degrees Fahrenheit (0.5 degrees Celsius) (NAI, 2001). As required by Seabrooks 16 NPDES permit, NextEra conducts continuous surface water monitoring. The mean difference in 17 temperature between a sampling station within 328 ft (100 m) of the discharge and a sampling 18 station 1.5 mi (2.5 km) to the north has not exceed 5 degrees Fahrenheit (2.8 degrees Celsius) 19 since operations began, which is the limit identified in the NPDES permit (EPA, 2002a; NAI, 20 2001; NAI, 2010). For the majority of months between August 1990 and December 2009, the 21 monthly mean increase in the surface water temperature was less than 3.6 degrees Fahrenheit 22 (2.0 degrees Celsius).

23 Based on Seabrooks water quality monitoring and Padmanabhan and Heckers (1991) study, 24 the habitat most likely affected by the thermal plume would be the upper water column (10-16 ft 25 (3 to 5 m) of the ocean surface) in the immediate vicinity of the discharge (less than 328 ft 26 (100 m)). Fish may avoid this area, but the thermal plume would not likely block fish movement 27 because fish could swim around the thermal plume. Pelagic fish species that may avoid this 28 area are discussed, as appropriate, in the species analysis below (Sections D-1.3.3.1-29 D-1.3.3.19). Benthic species, or species that primarily reside at the seafloor, may also avoid the 30 immediate area surrounding the discharge structures due to higher temperature, velocities, and 31 turbulence. This area should be considerably smaller than the area of increased temperature at 32 the surface.

33 To examine the potential thermal impacts from plant operations on sessile species (and as an 34 indicator of thermal impacts to other biological groups), NAI (2010) compared the abundance of 35 cold water and warm water macroalgae species prior to and during operations at sites near the 36 discharge structure (the nearfield site) and at sites approximately 3-4 nautical mi (5-8 km) from 37 the intake and discharge structures (the farfield site). Benthic perennial algae are sensitive to 38 changes in water temperature because they are immobile and live more than 2 years. Prior to 39 operations, NAI (2010) collected six uncommon species not collected during operations, 40 including the brown macroalga Petalonia fascia, which is associated with cold-water habitat.

41 During operations, NAI (2010) collected some typically warm-water taxa for the first time (e.g.,

42 the red macroalga Neosiphonia harveyi), collected other warm-water taxa less frequently, and 43 collected some cold-water taxa more frequently. NAI (2010) observed 10 species that only 44 occurred during operations, and NAI (2010) reported that these species were within their 45 geographic ranges. NAI (2010) concluded that the changes in community composition among 46 cold and warm water species were relatively small, although NAI (2010) did not report the 47 results of any statistical tests to examine the significance in such changes.

D-1-23

Appendix D-1 1 The NRC staff concluded in the SEIS that thermal impacts from Seabrook operations were 2 SMALL, and operations have not noticeably altered aquatic communities near Seabrook. This 3 conclusion was based on the findings that the thermal plume would not block fish passage and 4 is within the limits of Seabrooks NPDES permit and that there were no clear patterns of 5 emergent warm-water species or changes in the abundance of cold-water species.

6 Loss of Forage Species. Prey for the 23 EFH species includes phytoplankton, zooplankton 7 (including fish and invertebrate eggs and larvae), juvenile and adult fish, and juvenile and adult 8 invertebrates. Seabrook operations can adversely affect plankton prey if they are entrained in 9 the cooling system or the thermal discharge significantly decreases the quality of the pelagic 10 water habitat. Juvenile and adult fish prey could be affected by Seabrook operations if they are 11 impinged in the cooling water system, if they avoid the area near the discharge because of the 12 heated thermal effluent, or if bottom habitat (e.g., mussel beds or kelp forests) are adversely 13 affected by Seabrook operations. Invertebrate prey could be affected by Seabrook operations if 14 any of the following occurs:

15

• They are entrained in the Seabrook cooling system.

16

• They are mobile and impinged in the Seabrook cooling system.

17

• They are mobile and avoid the area near the discharge structures due to the discharge 18 of heated thermal effluent.

19

• They are sessile, and growth is limited near the discharge structures due to the heated 20 thermal effluent.

21 Loss of Habitat-Forming Species. In the Gulf of Maine, and the area in the vicinity of 22 Seabrooks intake and discharge structures, rocky subtidal habitats are among the most 23 productive habitats (Mann, 1973; Ojeda and

Dearborn,

1989). Algae, mussels, oysters, and 24 other sessile invertebrates attach to the bedrock on the seafloor and form the basis of a 25 complex, multi-dimensional habitat for other fish and invertebrates to use for feeding and hiding 26 from predators (Thompson, 2010; Witman and Dayton, 2001). Spawning fish, such as herring, 27 shield eggs from currents and predators within rock crevices or sessile organisms attached to 28 the bedrock (Thompson, 2010). In soft sediment habitats, shellfish beds form the main biogenic 29 habitats.

30 Kelp seaweeds, brown seaweeds with long blades, attach to hard substrates and can form the 31 basis of undersea forests, commonly referred to as kelp beds. The long blades of kelpsuch 32 as A. clathratum, L. digitata, and sea beltprovide the canopy layer of the undersea forest, 33 while shorter foliose and filamentous algae, such as Irish moss, grow in between or at the 34 bottom of kelp similar to the understory layer in a terrestrial forest (NAI, 2010; Thompson, 2010).

35 The multiple layers of seaweeds provide additional habitat complexity for other fish and 36 invertebrates to find refuge from predators and harsh environmental conditions, such as strong 37 currents or ultraviolet light (Thompson, 2010). Seabrooks heated effluent may affect growth of 38 algae and sessile invertebrates. These groups may be particularly sensitive to changes in water 39 quality because they are sessile and cannot move to avoid the area, sufficient light must reach 40 the algae for the plant to photosynthesize, and particulars in the water can clog the feeding 41 structures of sessile invertebrates that filter seawater for food.

42 D-1.3.2.2 Combined Impacts (Monitoring Data) 43 This section presents NextEra monitoring data of selected groups prior to and during operations 44 at sampling sites near the intake and discharge structures (nearfield sampling sites) and at D-1-24

Appendix D-1 1 sampling sites 3-4 mi (5-8 km) away (farfield sampling sites) (Figure D-1-7). Monitoring data 2 may indicate if the combined impacts (or cumulative impacts) from Seabrook operation have 3 resulted in the decline of a species or biological group due to a decline in habitat quantity or 4 quality.

Figure D-1-7. Sampling Stations for Seabrook Station aquatic monitoring D-1-25

Appendix D-1 1 NAI (2010) used a before-after control-impact (BACI) design to test for potential impacts from 2 operation of Seabrook. This monitoring design was used to test for the statistical significance of 3 differences in community structure, species abundance, or species diversity between the 4 pre-operational and operational period at the nearfield and farfield sites. Statistically significant 5 differences could result from entrainment, impingement, thermal impacts, loss of forage species, 6 loss of habitat-forming species, or any combination of these effects of Seabrook operations.

7 Working with NAI and Public Service of New Hampshire staff, NextEra selected farfield 8 sampling sites that would likely be outside the influence of Seabrook operations (NextEra, 9 2010a). The farfield sampling stations were between 3-4 nautical mi (5-8 km) north of the 10 intake and discharge structures. NextEra selected a northern farfield location because the 11 primary currents run north to south. NextEra selected specific farfield sampling sites based on 12 similarities with the nearfield sampling sites regarding depth, substrate type, algal composition, 13 wave energy, and other relevant factors (NextEra, 2010a).

14 Sections 2.2.6.3 and 4.5.5 of the SEIS describe the sampling methods, statistical methods, and 15 monitoring results. Below is a brief summary of the monitoring results for phytoplankton, 16 zooplankton, fish, invertebrates, and macroalgae.

17 Phytoplankton. NAI (1998) found no significant differences in phytoplankton abundance or 18 chlorophyll a concentrations between the nearfield and farfield sites or between before and 19 during plant operation. NAI (1998) observed minimal changes in species composition prior to 20 and during operations. These results suggest that Seabrook operations have not adversely 21 affected phytoplankton abundance near Seabrook.

22 Zooplankton. NAI (2010) did not find a significant difference in the density of holoplankton or 23 meroplankton taxa prior to and during operations or between the nearfield and farfield sampling 24 sites. The average density of all hyperbenthos species at the nearfield site was generally an 25 order of magnitude larger than the abundances found at the farfield site both prior to and during 26 operations (NAI, 2010).

27 When examining total bivalve larvae density, NAI (2010) did not find a significant difference 28 between sampling sites prior to and during operations. For fish eggs and larvae, NAI (2010) 29 observed no significant difference between sampling sites, but the study reported a significant 30 difference prior to and during operations in the density of fish eggs and larval species 31 (Table D-1-8).

32 Table D-1-8. Mean density (No./1000m3) and upper and lower 95% confidence limits (CL) 33 of the most common fish eggs and larvae from 1982-2009 monitoring data at Seabrook Group 1(a) Group 2 (a)

Taxon Lower 95% Upper 95% Lower 95% Upper 95%

Mean Mean CL CL CL CL Eggs(b)

Atlantic mackerel 650 1,009 1,369 1,344 1,941 2,538 Cunner/Yellowtail flounder 2,764 5,003 7,243 6,577 7,239 8,081 Hakes 235 1,226 2,217 332 488 643 Hake/ Fourbeard rockling 45 215 386 503 626 749 Atlantic cod/ haddock 79 153 226 63 92 120 D-1-26

Appendix D-1 Group 1(a) Group 2 (a)

Taxon Lower 95% Upper 95% Lower 95% Upper 95%

Mean Mean CL CL CL CL Windowpane 73 147 221 160 232 304 Fourbeard rockling 168 248 328 34 49 65 Silver hake 45 77 109 149 322 494 Larvae(c)

Cunner 143 425 707 828 1,386 1,945 American sand lance 57 182 307 160 234 308 Atlantic mackerel 28 179 330 65 121 176 Fourbeard rockling 40 68 96 56 78 99 Atlantic herring 37 68 99 23 29 35 Rock gunnel 14 31 49 32 42 52 Winter flounder 18 44 70 8 11 14 Silver hake 14 23 32 35 67 100 Radiated shanny 15 26 36 3 27 50 Witch flounder 9 18 28 3 5 6 (a)

NAI (2010) determined groups using a cluster analysis (numerical classification) and non-metric multi-dimensional scaling (MDS) of the annual means (log (x+1)) of each taxon at each station.

(b)

Egg Group 1 years = 1983, 1984, 1986, 1987; Group 2 years = 1988-2008 (c)

Larvae Group 2 years = 1982-1984, 1986-1989; Group 2 years = 1989-1991, 1993-2009 Source: NAI (2010) 1 Because changes in community structure occurred at nearfield and farfield sampling sites, these 2 results suggest that Seabrook operations have not adversely affected zooplankton near 3 Seabrook.

4 Juvenile and Adult Fish. NextEra monitored the abundance of juvenile and adult fish prior to 5 and during operations at nearfield and farfield sites using benthic trawls (Table D-1-9), gill nets 6 (Table D-1-10), and seine pulls in the Hampton-Seabrook Estuary (Table D-1-10). For the 7 majority of fish species, the abundance was higher prior to operations than during operations at 8 both the nearfield and farfield sites. The abundance of a few fish species increased during 9 operations at both nearfield and farfield sites.

10 Table D-1-9. Geometric mean catch per unit effort (CPUE) (No. per 10-minute tow) and 11 upper and lower 95% CL during preoperational and operational monitoring years for the 12 most abundant species Preoperational monitoring Operational monitoring Species Sample site Upper Lower 95% Upper Lower 95% CL Mean Mean 95% CL CL 95% CL Yellowtail flounder Nearfield (T2) 2.7 3.7 5.0 0.1 0.2 0.3 Farfield (T1) 15.7 20.6 26.9 1.8 2.4 3.1 Farfield (T3) 6.6 9.2 12.8 1.4 2.1 3.0 D-1-27

Appendix D-1 Preoperational monitoring Operational monitoring Species Sample site Upper Lower 95% Upper Lower 95% CL Mean Mean 95% CL CL 95% CL Longhorn sculpin Nearfield (T2) 0.6 1.0 1.5 0.4 0.6 0.8 Farfield (T1) 2.3 3.2 4.5 2.3 3.1 4.1 Farfield (T3) 4.2 6.1 8.5 4.8 6.4 8.4 Winter flounder Nearfield (T2) 3.7 5.5 8.0 1.6 2.3 3.1 Farfield (T1) 2.1 2.8 3.6 3.0 4.0 5.4 Farfield (T3) 1.1 1.4 1.9 2.7 3.6 4.8 Hake Nearfield (T2) 0.6 0.9 1.2 0.3 0.4 0.5 Farfield (T1) 1.3 1.7 2.0 0.4 0.6 0.8 Farfield (T3) 0.8 1.1 1.4 0.4 0.9 1.4 Atlantic cod Nearfield (T2) 0.5 0.8 1.2 0.1 0.2 0.4 Farfield (T1) 1.7 2.6 3.7 0.2 0.3 0.5 Farfield (T3) 2.6 4.1 6.2 0.8 1.1 1.5 Raja sp. Nearfield (T2) 0.4 0.6 0.7 0.4 0.7 0.9 Farfield (T1) 0.8 1.4 2.3 1.6 2.2 2.9 Farfield (T3) 2.0 2.6 3.2 2.6 3.5 4.7 Windowpane Nearfield (T2) 0.8 1.2 1.6 0.7 1.0 1.3 Farfield (T1) 1.1 1.6 2.3 1.4 1.8 2.2 Farfield (T3) 0.6 0.9 1.4 1.0 1.7 2.6 Rainbow smelt Nearfield (T2) 2.2 3.2 4.3 0.3 0.5 0.8 Farfield (T1) 1.6 2.3 3.1 0.4 0.6 0.9 Farfield (T3) 0.9 1.6 2.5 0.4 0.6 0.8 Ocean pout Nearfield (T2) 0.6 0.8 1.0 0.2 0.2 0.3 Farfield (T1) 0.6 0.7 1.0 0.1 0.1 0.2 Farfield (T3) 1.4 1.8 2.3 0.1 0.2 0.3 Silver hake Nearfield (T2) 0.0 0.1 0.1 0.0 0.0 0.1 Farfield (T1) 0.1 0.2 0.4 0.3 0.6 0.9 Farfield (T3) 0.1 0.2 0.3 0.1 0.3 0.6 Source: (NAI, 2010) 1 Table D-1-10. Geometric mean CPUE (No. per 24-hr surface and bottom gill net set) and 2 coefficient of variation (CV) during preoperational (1976-1989) and operational 3 monitoring years (1990-1996)

Preoperational monitoring Operational monitoring Species Sample site Mean CV Mean CV Atlantic herring Nearfield (G2) 1.1 20 0.2 33 Farfield (G1) 1.0 18 0.3 22 D-1-28

Appendix D-1 Farfield (G3) 1.2 21 0.4 25 Atlantic mackerel Nearfield (G2) 0.2 15 0.3 29 Farfield (G1) 0.2 16 0.3 17 Farfield (G3) 0.3 16 0.3 15 Pollock Nearfield (G2) 0.3 10 0.3 16 Farfield (G1) 0.2 17 0.2 18 Farfield (G3) 0.3 13 0.2 13 Spiny dogfish Nearfield (G2) <0.1 35 0.1 41 Farfield (G1) <0.1 45 0.1 69 Farfield (G3) <0.1 27 0.2 47 Silver hake Nearfield (G2) 0.2 35 0.1 60 Farfield (G1) 0.2 34 0.1 40 Farfield (G3) 0.3 31 0.1 31 Blueback herring Nearfield (G2) 0.3 18 0.2 26 Farfield (G1) 0.2 17 0.2 50 Farfield (G3) 0.3 24 0.2 32 Alewife Nearfield (G2) 0.1 14 0.1 21 Farfield (G1) 0.1 17 0.1 34 Farfield (G3) 0.1 21 0.1 35 Rainbow smelt Nearfield (G2) 0.1 21 0.1 29 Farfield (G1) <0.1 26 0.1 40 Farfield (G3) 0.1 21 0.1 39 Atlantic cod Nearfield (G2) <0.1 22 <0.1 63 Farfield (G1) 0.1 18 <0.1 53 Farfield (G3) 0.1 13 <0.1 63 Source: (NAI, 1998) 1 NAI (2010) reported different trends at farfield and nearfield sites for winter flounder, silver hake, 2 and rainbow smelt during trawling surveys (Table D-1-9). At the nearfield site (T2), the 3 abundance of winter flounder significantly decreased over time from a mean CPUE of 5.5 prior 4 to operations to 2.3 during operations. However, at both farfield sampling sites (T1 and T3), the 5 mean CPUE increased from 2.8 and 1.4 prior to operations, respectively, to 4.0 and 3.6 during 6 operations. This increase was statistically significant at one of the farfield sites (T3). Silver 7 hake abundance also increased at farfield sampling sites and decreased at the nearfield 8 sampling site. NAI (2010) did not report if these trends were statistically significant. Rainbow 9 smelt abundance decreased at all sampling sites, but the decrease was significantly greater at 10 the nearfield site compared to the farfield sites (NAI, 2010).

11 NAI (2010) reported different trends at farfield and nearfield sites for American sand lance 12 abundances during seine pulls in the Hampton-Seabrook Estuary (Table D-1-11). At the 13 nearfield sampling station (S2), the abundance of American sand lance decreased over time 14 from a mean CPUE of 0.2 prior to operations to 0.1 during operations. At both farfield sampling 15 sites (S1 and S3), the mean CPUE increased from 0.1 prior to operations, to 0.2 and 0.6, D-1-29

Appendix D-1 1 respectively, during operations. NAI (2010) did not report if these trends were statistically 2 significant.

3 Table D-1-11. Geometric mean CPUE (No. per seine haul) and upper and lower 95% CL 4 during preoperational and operational monitoring years Preoperational monitoring Operational monitoring Species Sample site Lower Upper Lower Upper Mean Mean 95% CL 95% CL 95% CL 95% CL Atlantic silverside Nearfield (S2) 5.1 6.8 9.1 2.4 3.1 4.1 Farfield (S1) 5.1 7.2 10.2 3.6 4.8 6.2 Farfield (S3) 4.0 6.7 10.7 2.1 2.9 3.9 Winter flounder Nearfield (S2) 0.6 1.0 1.5 0.1 0.2 0.3 Farfield (S1) 0.6 0.9 1.2 0.2 0.4 0.5 Farfield (S3) 2.2 3.2 4.4 0.3 0.5 0.7 Killifishes Nearfield (S2) 0.6 1.2 2.0 0.1 0.2 0.3 Farfield (S1) 0.8 1.1 1.5 0.5 0.9 1.3 Farfield (S3) <0.1 <0.1 0.1 0.1 <0.1 0.1 Ninespine stickleback Nearfield (S2) 0.3 0.8 1.6 <0.1 0.1 0.1 Farfield (S1) 0.4 0.7 1.2 0.1 0.2 0.3 Farfield (S3) 0.3 0.8 1.4 0.1 0.2 0.3 Rainbow smelt Nearfield (S2) <0.1 0.2 0.3 0.1 0.1 0.2 Farfield (S1) <0.1 0.1 0.2 <0.1 0.1 0.2 Farfield (S3) 0.3 0.7 1.2 0.1 0.2 0.4 American sand lance Nearfield (S2) 0.0 0.2 0.5 0.0 0.1 0.1 Farfield (S1) <0.1 0.1 0.2 0.1 0.2 0.3 Farfield (S3) <0.1 0.1 0.2 0.3 0.6 0.9 Pollock Nearfield (S2) <0.1 0.2 0.3 0.0 <0.1 <0.1 Farfield (S1) <0.1 0.1 0.2 <0.1 <0.1 <0.1 Farfield (S3) 0.1 0.4 0.8 <0.1 0.1 0.1 Blueback herring Nearfield (S2) <0.1 0.1 0.1 <0.1 0.1 0.1 Farfield (S1) 0.1 0.2 0.3 0.1 0.3 0.4 Farfield (S3) <0.1 0.1 0.3 <0.1 <0.1 0.1 Atlantic herring Nearfield (S2) 0.1 0.3 0.5 <0.1 <0.1 0.1 Farfield (S1) 0.0 0.1 0.5 0.1 0.2 0.3 Farfield (S3) 0.1 0.1 0.2 <0.1 0.1 0.2 Alewife Nearfield (S2) 0.0 0.1 0.2 <0.1 <0.1 <0.1 Farfield (S1) <0.1 0.1 0.2 0.1 0.2 0.4 Farfield (S3) <0.1 0.1 0.1 0.0 0.1 0.2 Source: (NAI, 2010)

D-1-30

Appendix D-1 1 NextEra monitoring results suggest that Seabrook operations have not likely affected most fish 2 species near Seabrook. However, the abundance of winter flounder and rainbow smelt has 3 decreased to a greater and observable extent near Seabrooks intake and discharge structures 4 compared to 3-4 mi (5-8 km) away. The local decrease suggests that, to the extent local 5 subpopulations exist within 3-4 mi (5-8 km) of Seabrook, they have been adversely affected 6 through operation of Seabrooks cooling water system.

7 Invertebrates. NAI (2010) reported similar trends of total invertebrate density and species 8 diversity at the nearfield and farfield sampling sites before and during operations. Likewise, NAI 9 (2010) reported similar trends at the nearfield and farfield sampling sites prior to and during 10 operations for mytilid (mussel) spat, rock crabs, Jonah crabs, northern horse mussels, sea 11 stars, green sea urchin, lobsters, and soft shell clams.

12 Macroaglae. NAI (2010) observed significant changes in kelp density prior to and during 13 operations (Table D-1-12). NAI (2010) reported significantly higher Laminaria digitata density 14 prior to than during operations. In the shallow and the mid-depth subtidal, the decline at the 15 nearfield sampling site was significantly greater than the decline at the farfield station. In the 16 nearfield mid-depth sampling site (B19), NAI (2010) did not identify L. digitata in 2008 or 2009.

17 The density of Agarum clathratum, which competes with L. digitata, significantly increased over 18 time in the mid-depth sampling stations, and density was significantly higher at the nearfield site 19 (NAI, 2010).

20 Table D-1-12. Kelp density (No. per 100 m2) and upper and lower 95% CL during 21 preoperational and operational monitoring years Preoperational monitoring Operational monitoring Kelp Sample site Lower Upper Lower Upper Mean Mean 95% CL 95% CL 95% CL 95% CL L. digitata Nearfield Shallow (B17) 140.6 213.9 287.3 5.3 15.2 25.2 Farfield Shallow (B35) 96.5 155.8 215.1 52.3 73.9 95.6 Nearfield Mid-depth (B19) 81.5 139.9 198.3 3.1 7.5 11.9 Farfield Mid-depth (B31) 401.6 500.2 598.7 106.0 157.7 209.5 Sea belt Nearfield Shallow (B17) 270.7 415.1 559.4 66.1 137.9 209.7 Farfield Shallow (B35) 210.9 325.7 440.5 247.8 326.0 404.2 Nearfield Mid-depth (B19) 2.0 59.1 116.3 1.5 10.1 18.7 Farfield Mid-depth (B31) 59.6 95.5 131.5 29.3 48.2 68.2 A. esculenta Nearfield Mid-depth (B19) 0.0 2.4 7.2 0.3 2.3 4.2 Farfield Mid-depth (B31) 19.9 75.2 130.5 20.3 40.0 59.6 A. clathratum Nearfield Mid-depth (B19) 613.5 786.6 959.6 792.2 955.2 1,118.1 Farfield Mid-depth (B31) 280.2 366.4 452.6 407.3 503.6 599.9 Source: (NAI, 2010) 22 In the shallow subtidal, sea belt (Saccharina latissima) density was significantly lower during 23 operations at the nearfield site, but there was no significant change at the farfield site 24 (NAI, 2010). In the mid-depth subtidal, sea belt density significantly decreased at both sampling 25 sites (NAI, 2010). In the mid-depth subtidal, Alaria esulenta significantly declined during 26 operations at the farfield site and remained at a low density at the nearfield site prior to and D-1-31

Appendix D-1 1 during operations (NAI, 2010). NAI (2010) did not identify A. esulenta at the nearfield sampling 2 station over the past 4 years.

3 The decrease in L. digitata density was significantly greater at the nearfield sites, and sea belt 4 density was lower during operations at the nearfield site but not at the farfield site in the shallow 5 subtidal. These results suggest that the local population of L. digitata and sea belt has been 6 adversely affected through operation of Seabrooks cooling water system.

7 D-1.3.3 Adverse Effects on Essential Fish Habitat by Species 8 D-1.3.3.1 American Plaice (Hippoglossoides platessoides) (Juvenile and Adult) 9 Designated EFH in the Vicinity of Seabrook. The NMFS has designated American plaice 10 juvenile and adult EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 11 American plaice juveniles and adults or both in 110 percent of trawling samples from the 12 1970s-2009 (Table D-1-2).

13 Species Description. American plaice are arctic-boreal pleuronectid flatfish (Johnson, 1995).

14 American plaice inhabit both sides of the Atlantic Ocean. In the western Atlantic, American 15 plaice are common from Newfoundland, Canada to Montauk Point, NY (Bigelow and Schroeder, 16 1953; Johnson, 2005). EFH for American plaice juveniles and adults includes bottom habitats 17 with fine-grained, sandy, or gravel substrates in the Gulf of Maine (NMFS, 2011c). American 18 plaice are relatively sedentary, and tagging studies have indicated that few migrate long 19 distances. Fisheries and Oceans Canada (DFO) (1989 in Johnson 2005) recaptured the 20 majority of tagged fish within 30 mi (48 km) of the tagging site after 7-8 years.

21 American plaice consume a wide-variety of prey and are opportunistic feeders, in that they will 22 consume what is most available (Johnson, 2005). Prior to settling on the ocean floor, juveniles 23 feed on small crustaceanssuch as cumaceansand polychaetes (Bigelow and Schroeder, 24 1953). Adults are primarily benthic but, at night, may migrate up into pelagic waters to prey on 25 non-benthic species (DFO, 1989 in Johnson, 2005). During monitoring surveys, NAI (2010) did 26 not observe American plaice in pelagic waters. Prey for adults include mostly echinoderms 27 (e.g., sand dollars, sea urchins, and brittle stars) and crustaceans, cnidarians, and polychaetes 28 (Johnson, 2005). Redfish eat American plaice larvae, and goosefish, halibut, cod, and other 29 bottom feeders prey on the adults (Johnson, 2005).

30 Status of the Fishery. NMFS, the New England Fishery Management Council (NEFMC), and 31 the Mid-Atlantic Fishery Management Council (MAFMC) currently manage the northeast 32 multispecies fisheries management plan (FMP). The U.S. fishery for American plaice started to 33 develop around 1975 in the Gulf of Maine, when other commercially desirable flatfish (e.g.,

34 yellowtail flounder, winter flounder, and summer flounder) began to decrease in abundance 35 (Sullivan, 1981 in Johnson, 2005). American plaice populations in the western North Atlantic 36 have declined dramatically since the early 1980s (Johnson, 2005). Contributing factors to the 37 decline are likely overfishing, changes in water temperature, and water pollution (Johnson, 38 2005). American plaice is also bycatch for other fisheries. In New England, the mortality of 39 American plaice bycatch was positively correlated with ondeck sorting time (Johnson, 2005). In 40 2009, NEFMC considered American plaice overfished (NMFS, 2010b).

41 Entrainment and Impingement at Seabrook. Although NMFS has not designated EFH for 42 American plaice eggs and larvae, entrainment and impingement can adversely affect 43 recruitment of juveniles and adults. Entrainment of American plaice eggs varied from 0.4 million D-1-32

Appendix D-1 1 in 1994 to 52.3 million in 1992 (NAI, 2010). Annual average entrainment of American plaice 2 eggs was 25.9 million per year (Table D-1-4). American plaice eggs comprised approximately 3 3 percent of the total fish eggs entrained at Seabrook.

4 Entrainment of American plaice larvae varied from 0 in 1994 to 11.5 million in 2009 (NAI, 2010).

5 Annual average entrainment of American plaice larvae was 4.3 million per year (Table D-1-5).

6 American plaice larvae comprised approximately 1.5 percent of the total fish larvae entrained at 7 Seabrook.

8 Impingement of American plaice varied from zero in several years to seven in 2008 (NAI, 2010).

9 Annual average impingement was less than one fish per year (Table D-1-6). American plaice 10 comprised less than 1 percent of all impinged fish at Seabrook.

11 Because entrainment and impingement were relatively low for American plaice compared to 12 other species at Seabrook, the NRC staff concludes that entrainment and impingement are not 13 likely to adversely affect EFH for juvenile and adult American plaice during the remainder of the 14 facilitys operating license or during the proposed license renewal term.

15 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 16 available habitat to juvenile or adult American plaice. American plaice are primarily benthic 17 (Johnson, 2005). A relatively small area near the discharge structure in deep water experiences 18 increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant 19 thermal plume at the discharge points quickly rises toward the surface, the NRC staff concludes 20 that the heated effluent from Seabrook is not likely to adversely affect EFH for juvenile and adult 21 American plaice during the remainder of the facilitys operating license or during the proposed 22 license renewal term.

23 Loss of Forage Species. Juvenile and adult American plaice are opportunistic feeds that 24 primarily consume invertebrates, including green sea urchins (Strongylocentrotus 25 droebachiensis) (Johnson, 2005). NextEra monitoring data show relatively similar trends of 26 benthic invertebrate abundance, density, and species diversityincluding the abundance of 27 green sea urchinsprior to and during operations at sampling sites near the intake and 28 discharge structures and 3-4 mi (5-8 km) away (NAI, 2010). Therefore, the NRC staff 29 concludes that the potential loss of forage species at Seabrook is not likely to adversely affect 30 EFH for juvenile and adult American plaice during the remainder of the facilitys operating 31 license or during the proposed license renewal term.

32 Loss of Habitat-Forming Species. American plaice inhabit soft bottom areas, including soft 33 bottom areas that border bedrock (Johnson, 2005). Keats (1991) hypothesized that American 34 plaice inhabited areas boarded by bedrock because bedrock is the preferred habitat for green 35 sea urchins, an important prey species for American plaice. Because preferred habitat for 36 American plaice are soft bottom substrates, such as fine sand or gravel, the NRC concludes 37 that the potential loss of habitat-forming species is not likely to adversely affect EFH for juvenile 38 and adult American plaice during the remainder of the facilitys operating license or during the 39 proposed license renewal term.

40 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 41 the abundance of juvenile and adult American plaice prior to and during operations (NAI, 2010).

42 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 43 are not likely to adversely affect EFH for American plaice juveniles or adults for the following 44 reasons:

D-1-33

Appendix D-1 1

• Impingement and entrainment are relatively low.

2

• The thermal plume rises quickly to the surface.

3

• Invertebrate forage species are not likely adversely affected by Seabrook operations.

4

• Preferred habitat does not include shellfish or kelp beds.

5 D-1.3.3.2 Atlantic butterfish (Peprilus triacanthus) (All Life Stages) 6 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 7 and adult Atlantic butterfish EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) 8 observed Atlantic butterfish eggs and larvae in 110 percent of ichthyoplankton tows, juveniles 9 and adults in 1-10 percent of gill net samples, juveniles and adults in less than 1 percent of 10 trawling samples, and juveniles and adults in less than 1 percent of seine pull samples 11 (Table D-1-2).

12 Species Description. Adult Atlantic butterfish are pelagic schooling fish that are ecologically 13 important as a forage fish for many larger fishes, marine mammals, and birds. Atlantic 14 butterfish inhabit the Atlantic coast from Newfoundland to Florida, but it is most abundant from 15 the Gulf of Maine to Cape Hatteras (Cross et al., 1999; Overholtz, 2006). Adult butterfish 16 migrate seasonally. In the summer, they migrate inshore into bays, estuaries, and coastal 17 waters of southern New England and the Gulf of Maine. In winter, they migrate to the edge of 18 the continental shelf in the Mid-Atlantic Bight (Cross et al., 1999). Adults generally stay within 19 200 mi (322 km) of the shore.

20 Butterfish reach sexual maturity between ages 1-2 years and rarely live more than 3 years 21 (Overholtz, 2006). Adults are 5.9-9.1 in. (15-23 cm) long on average and can reach a weight of 22 up to 1.1 pounds (lb) (0.5 kilograms (kg)). Females are broadcast spawners and spawn in large 23 bays and estuaries from June-August. Females generally release eggs at night in the upper 24 part of the water column in water of 59 degrees Fahrenheit (15 degrees Celsius) or more. Eggs 25 are pelagic and buoyant (Cross et al., 1999). Butterfish eggs and larvae are found in water with 26 depths ranging from the shore to 6,000 ft (1,828 m) and at temperatures between 53.6-73.4 27 degrees Fahrenheit (12-23 degrees Celsius) for eggs and between 39.2-82.4 degrees 28 Fahrenheit (4-28 degrees Celsius) for larvae (Cross et al., 1999). Juvenile and adult butterfish 29 are found in waters from 33-1,200 ft (10-366 m) deep and at temperatures ranging from 37-82 30 degrees Fahrenheit (3-28 degrees Celsius) (Cross et al., 1999). In summer, juvenile and adult 31 butterfish can be found over the entire continental shelf, including sheltered bays and estuaries, 32 to a depth of 656 ft (200 m) over substrates of sand, rock, or mud (Cross et al., 1999).

33 Butterfish prey mainly on urochordates and mollusks, with minor food sources including squid; 34 crustaceans, such as amphipods and shrimp; annelid worms; and small fishes (Bigelow and 35 Schroeder, 2002; Cross et al., 1999). In turn, many speciesincluding haddock, silver hake, 36 goosefish, bluefish, swordfish (Xiphias gladuis), sharks, and longfin inshore squideat adult 37 butterfish (Cross et al., 1999).

38 Status of the Fishery. The Atlantic butterfish has been commercially fished since the late 1800s 39 (Cross et al., 1999). By the mid-1900s, fishing fleets from Japan, Poland, the USSR, and other 40 countries began to target the butterfish and caused a drastic increase in landings (Cross et al.,

41 1999; Overholtz, 2006). Landings peaked in 1973 at 75.6 million lb (34,300 metric tons (MT))

42 (Overholtz, 2006). U.S. commercial landings averaged 7.1 million lb (3,200 MT) from 43 19652002 but have steadily decreased since 1985 (Overholtz, 2006). In 2009, NOAA reported 44 a cumulative landing of 0.95 million lb (430 MT), and, as of November 27, 2010, the reported 45 landings for 2010 were 1.2 million lb (550 MT) (NOAA, 2009; NOAA, 2010). Butterfish are also D-1-34

Appendix D-1 1 caught as bycatch in other fisheries. Bycatch landings averaged 9.3 million lb (4,200 MT) per 2 year from 1996-2002 (Overholtz, 2006).

3 The MAFMC manages the Atlantic butterfish under an FMP that includes the Atlantic mackerel, 4 squid, and butterfish. The Atlantic butterfish fishery is capped by an annual coast-wide quota.

5 A directed fishery for butterfish is open from January-August; however, most butterfish are 6 harvested as bycatch in squid fisheries (NOAA, 2010a). In 2009, NEFMC reported butterfish to 7 be overfished (NMFS, 2010b).

8 Entrainment and Impingement. Entrainment of Atlantic butterfish eggs varied from 0 in several 9 years to 400,000 in 2005 (NAI, 2010). Annual average entrainment of Atlantic butterfish eggs 10 was 25,500 per year from 1990-2009 (Table D-1-4). Entrainment of Atlantic butterfish larvae 11 varied from 0 in several years to 1.19 million in 2007 (NAI, 2010). Annual average entrainment 12 of Atlantic butterfish larvae was 90,000 per year from 1990-2009 (Table D-1-5). Atlantic 13 butterfish eggs and larvae comprised less than 0.05 percent of the total fish eggs and larvae 14 entrained at Seabrook from 1990-2009.

15 Impingement of Atlantic butterfish varied from 1 in 2000 to 1,170 in 2002 (NAI, 2010). Annual 16 average impingement was 114 fish per year from 1994-2009 (Table D-1-6). Atlantic butterfish 17 comprised less than 1 percent of all impinged fish at Seabrook from 1994-2009.

18 Because entrainment and impingement were relatively low for Atlantic butterfish compared to 19 other species at Seabrook, the NRC staff concludes that entrainment and impingement are not 20 likely to adversely affect EFH for all life stages of Atlantic butterfish during the remainder of the 21 facilitys operating license or during the proposed license renewal term.

22 Thermal Impacts. The NRC staff does not expect Seabrooks thermal discharges to reduce 23 available habitat to butterfish eggs, larvae, juveniles, or adults. As described above, the habitat 24 most likely affected by the thermal plume would be the upper water column (within 10-16 ft (3-25 5 m)) of the ocean surface) in the immediate vicinity of the discharge. At the surface, 26 Padmanabhan and Hecker (1991) observed a temperature rise of 3 degrees Fahrenheit 27 (1.7 degrees Celsius) or more in a 32-ac (12.9-ha) area surrounding the discharge. Seabrooks 28 NPDES permit limits the rise in monthly mean temperature to 5 degrees Fahrenheit 29 (2.8 degrees Celsius) in the near field jet mixing region, or within waters less than 3.3 ft (1 m) 30 from the surface. Butterfish are most common near Seabrook from August-November, when 31 the surface temperature near Seabrook ranges from 46.4-65.8 degrees Fahrenheit (8-18.8 32 degrees Celsius) (NAI, 2001). Butterfish eggs and larvae are found in water at temperatures 33 between 53.6-73.4 degrees Fahrenheit (12-23 degrees Celsius) for eggs and between 39.2-34 82.4 degrees Fahrenheit (4-28 degrees Celsius) for larvae (Cross et al., 1999). Juvenile and 35 adult butterfish are found in waters at temperatures ranging from 37-82 degrees Fahrenheit (3-36 28 degrees Celsius) (Cross et al., 1999). With a temperature rise of 3-5 degrees Fahrenheit 37 (1.72.8 degrees Celsius) at the surface near Seabrook, the thermal plume near the surface 38 from August-November would be within the range of temperature that butterfish eggs, larvae, 39 juveniles, and adults typically inhabit. Therefore, the NRC staff concludes that the increased 40 temperatures of Seabrooks effluent are not likely to adversely affect EFH for all stages of 41 Atlantic butterfish during the remainder of the facilitys operating license or during the proposed 42 license renewal term.

43 Loss of Forage Species. Atlantic butterfish primarily prey on invertebrates (Bigelow and 44 Schroeder, 2002; Cross et al., 1999). NextEra monitoring data show relatively similar trends of 45 benthic invertebrate density and species diversity prior to and during operations at sampling 46 sites near the intake and discharge structures and 3-4 mi (5-8 km) away (NAI, 2010).

D-1-35

Appendix D-1 1 Therefore, the NRC staff concludes that the potential loss of forage species at Seabrook is not 2 likely to adversely affect EFH for Atlantic butterfish during the remainder of the facilitys 3 operating license or during the proposed license renewal term.

4 Loss of Habitat-forming Species. All life stages of Atlantic butterfish are primarily pelagic (Cross 5 et al., 1999), suggesting that they rarely use benthic habitats such as shellfish and kelp beds.

6 Therefore, the NRC staff concludes that the potential loss of habitat-forming species is not likely 7 to adversely affect EFH for all life stages of Atlantic butterfish during the remainder of the 8 facilitys operating license or during the proposed license renewal term.

9 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 10 the abundance of Atlantic butterfish eggs, larvae, juveniles, or adults prior to and during 11 operations (NAI, 2010).

12 Conclusion 13 Based on the above analysis, the NRC staff concludes that Seabrook operations are not likely 14 to adversely affect EFH for all life stages of Atlantic butterfish for the following reasons:

15

• Impingement and entrainment are relatively low for Atlantic butterfish.

16

• The increased temperature within the thermal plume at the surface would be with the 17 range of temperatures that Atlantic butterfish inhabit.

18

• Invertebrate forage species are not likely to be adversely affected by Seabrook 19 operations.

20

• Their preferred habitat does not include shellfish or kelp beds.

21 D-1.3.3.3 Atlantic cod (Gadus morhua) (All Life Stages) 22 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 23 and adult Atlantic cod EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 24 Atlantic cod eggs and larvae in greater than 10 percent of ichthyoplankton tows, juveniles and 25 adults in greater than 10 percent of trawling samples, juveniles and adults in 1-10 percent of gill 26 net samples, and juveniles and adults in less than 1 percent of seine pull samples 27 (Table D-1-2).

28 Species Description. Atlantic cod are demersal and highly-targeted commercially. Atlantic cod 29 inhabit the northwestern Atlantic Ocean, from Greenland to Cape Hatteras, NC. In the U.S., the 30 highest densities of Atlantic cod are on Georges Bank and the western Gulf of Maine, in waters 31 between 33-492 ft (10-150 m) with rough bottoms and at temperatures between 3250 32 degrees Fahrenheit (0-10 degrees Celsius) (Lough, 2004). Offshore New England, juvenile 33 and adult Atlantic cod move seasonally in response to temperature changes, whereby Atlantic 34 cod typically move into coastal waters during the fall and deeper waters during spring. At the 35 extremes of their range, including Labrador and south of the Chesapeake, Atlantic cod migrate 36 annually (Lough, 2004).

37 In Gulf of Maine, Atlantic cod reach sexual maturity at 2.1-2.9 years at lengths between 13-17 38 in. (32-44 cm) (Lough, 2004). Females spawn during winter and early spring in bottom waters 39 generally between 41-44.6 degrees Fahrenheit (5-7 degrees Celsius). A large female may 40 produce as many as 3-9 million eggs (Lough, 2004). Eggs and larvae for the first 3 months are 41 pelagic (Lough, 2004). Once larvae reach 1.6-2.4 in. (4-6 cm), they begin to descend towards D-1-36

Appendix D-1 1 the seafloor. As Atlantic cod develop into juveniles and adults, they are able to withstand 2 deeper, colder, and more saline water, and they become more widely distributed (Lough, 2004).

3 Complex substrate and vegetation provides refuge from predators for juvenile cod (Lough, 4 2004).

5 Forage species tend to vary by life stage and location (Lough, 2004). Juveniles and younger 6 adults tend to consume pelagic and benthic invertebrates, while adult cod feed on both 7 crustaceans and other fish, including cancer crabs, brittle stars, American sand lance, Atlantic 8 herring, and American plaice (Johnson, 2005; Lough, 2004; Witman and Sebens, 1992).

9 Atlantic herring and Atlantic mackerel can be important predators of Atlantic cod larvae 10 (Lough, 2004). Silver hake, sclupin, larger cod, and other fish consume juvenile Atlantic cod 11 (Edwards and Bowman, 1979 in Lough, 2004). Winter skate, silver hake, sea raven, longfin 12 inshore squid, Atlantic halibut, fourspot flounder, and large adult cod consume smaller adult cod 13 (Lough, 2004).

14 Status of the Fishery. Atlantic cod has been a highly targeted species since the 1700s. As a 15 likely result of harvesting older and larger fish or due to intense exploitation in stock biomass, 16 the size and age at maturity for Atlantic cod has declined in recent decades (Lough, 2004).

17 Currently, Atlantic cod is managed as two stocks within U.S. waters: (1) the Gulf of Maine and 18 (2) Georges Bank and southward (Mayo, 1995). In 2009, NEFMC reported Atlantic cod to be 19 subject to overfishing (NMFS, 2010b).

20 Entrainment and Impingement. Entrainment of Atlantic cod eggs varied from 0.2 million in 1994 21 to 77.8 million in 2002 (NextEra, 2010a). Annual average entrainment of Atlantic cod eggs was 22 32.6 million per year from 1990-2009 (Table D-1-4). Atlantic cod eggs comprised 3.6 percent of 23 the total fish eggs entrained at Seabrook from 1990-2009. Entrainment of Atlantic cod larvae 24 varied from 0 in 1994 to 34.6 million in 2002 (NAI, 2010). Annual average entrainment of 25 Atlantic cod larvae was 2.8 million per year from 1990-2009 (Table D-1-5). Atlantic cod larvae 26 comprised approximately 1 percent of the total fish larvae entrained at Seabrook from 27 19902009.

28 Impingement of Atlantic cod varied from 29 in 2000 to 3,091 in 2003 (NAI, 2010). Annual 29 average impingement was 327 fish per year from 1994-2009 (Table D-1-6). Atlantic cod 30 comprised less than 2 percent of all impinged fish at Seabrook from 1994-2009.

31 Because entrainment and impingement were relatively low for Atlantic cod compared to other 32 species at Seabrook, the NRC staff concludes that entrainment and impingement are not likely 33 to adversely affect EFH for Atlantic cod during the remainder of the facilitys operating license or 34 during the proposed license renewal term.

35 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 36 available habitat to Atlantic cod eggs, juveniles, or adults. Seabrooks thermal discharge may 37 reduce available habitat to Atlantic cod larvae.

38 Atlantic cod eggs and larvae are pelagic (Lough, 2004). NEFSC MARMAP ichthyoplankton 39 surveys collected most eggs at temperatures ranging from 39-57 degrees Fahrenheit (4-40 14 degrees Celsius), but collected eggs as high as 72 degrees Fahrenheit (22 degrees Celsius) 41 (Lough, 2004). NEFSC MARMAP ichthyoplankton surveys collected most larvae from 39-52 42 degrees Fahrenheit (4-11 degrees Celsius), but collected larvae as high as 66 degrees 43 Fahrenheit (19 degrees Celsius) (Lough, 2004). Surface waters near the thermal plume 44 typically range as high as 65.8 degrees Fahrenheit (18.8 degrees Celsius) (NAI, 2001). With a 45 temperature rise of 3-5 degrees Fahrenheit (1.7-2.8 degrees Celsius), the thermal plume near D-1-37

Appendix D-1 1 the surface could exceed the typical range of temperatures that Atlantic cod larvae inhabit. The 2 habitat affected at the surface would likely be 32 ac (12.9 ha) or less (Padmanabhan and 3 Hecker, 1991). Juvenile and adult Atlantic cod are primarily benthic (Lough, 2004), meaning 4 that they spend most of the time residing near the seafloor. A relatively small area near the 5 discharge structure in deep water experiences increased temperatures (NAI, 2001; 6 Padmanabhan and Hecker, 1991). Because the buoyant thermal plume at the discharge points 7 quickly rises toward the surface and the temperature range of the thermal plume near the 8 surface would be within the typical range for Atlantic cod eggs, the NRC staff concludes that the 9 heated effluent from Seabrook is not likely to adversely affect EFH for Atlantic cod eggs, 10 juveniles, or adults during the remainder of the facilitys operating license or during the proposed 11 license renewal term. Because the thermal plume could exceed the typical range of 12 temperatures that larvae inhabit, the NRC staff concludes that the heated thermal effluent may 13 have minimal adverse effects on Atlantic cod larvae.

14 Loss of Forage Species. Juveniles and younger adults consume pelagic and benthic 15 invertebrates, while adult cod feed on both crustaceans and other fish (Lough, 2004). In the 16 Gulf of Maine, Bowman (1975 in Lough, 2004) found Atlantic herring to be a primary prey item 17 for Atlantic cod. Link and Garrison (2002) determined that preferred prey in the Gulf of Maine 18 include American sand lance, cancer crabs, and Atlantic herring. NextEra monitoring data show 19 relatively similar trends in the abundance and density of benthic invertebrates (including cancer 20 crabs) and most fish species prior to and during operations at sampling sites near the intake 21 and discharge structures and 34 mi (5-8 km) away (NAI, 2010). Atlantic herring, a primary 22 prey item for Atlantic cod in the Gulf of Maine, was the fifth most commonly entrained larval 23 species, comprising 3.6 percent of all entrained larvae (NAI, 2010) (Table D-1-5). Atlantic 24 herring comprised less than 1 percent of all impinged fish (NAI, 2010) (Table D-1-6). American 25 sand lance, a preferred prey item for Atlantic cod, was the second most commonly entrained 26 larval species, comprising 10 percent of all entrained larvae (NAI, 2010) (Table D-1-5).

27 American sand lance was the 10th most commonly impinged fish species, comprising 28 4.3 percent of all impinged fish (NAI, 2010) (Table D-1-6).

29 Because some of the primary and preferred forage fishsuch as Atlantic herring and American 30 sand lanceare regularly entrained and impinged at Seabrook, operations at Seabrook may 31 have a minimal adverse effect on prey abundance for Atlantic cod. Effects would likely be 32 minimal since Atlantic cod consume a variety of species, many of which are not regularly 33 entrained or impinged at Seabrook.

34 Loss of Habitat-forming Species. Complex substrate and vegetation provide refuge from 35 predators for juvenile cod (Lough, 2004). Therefore, juvenile cod likely use macroalgae and 36 shellfish beds near Seabrook. Monitoring studies suggest that Seabrook operations have 37 adversely affected the density of several kelp species near Seabrook. Therefore, Seabrook 38 operations may have a minimal adverse effect on juvenile Atlantic cod habitat. Effects would 39 likely be minimal since juvenile Atlantic cod inhabit a variety of substrates and vegetation to find 40 refuge from predators.

41 Combined Impacts (Monitoring Data). NextEra monitored the abundance of eggs, larvae, 42 juvenile and adult Atlantic cod prior to and during operations at sampling sites near the intake 43 and discharge structures and at sites 3-4 mi (5-8 km) away. Ichthyoplankton studies indicated 44 that the density of Atlantic cod larvae decreased significantly at both nearfield and farfield 45 sampling sites (NAI, 2010) (Table D-1-8). Monitoring data from trawl studies and gill net studies 46 indicate that the abundance of juvenile and adult Atlantic cod also significantly decreased at 47 both nearfield and farfield sampling sites (Tables D-1-9 and D-1-10). The decreased D-1-38

Appendix D-1 1 abundance at both nearfield and farfield sampling sites suggest that Seabrook operations have 2 not adversely affected EFH for Atlantic cod within 3-4 mi (5-8 km) of Seabrook.

3 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 4 may have minimal adverse effects on EFH for Atlantic cod larvae, juveniles, and adults, 5 because Seabrooks cooling system regularly entrains and impinges preferred forage fish for 6 Atlantic cod, the thermal plume could exceed the typical range of temperatures that larvae 7 inhabit, and because juveniles may use algal habitats that have declined near Seabrook since 8 operations began. Impacts would likely be minimal since Atlantic cod are not commonly 9 entrained or impinged in the Seabrook cooling system, the thermal plume rises quickly to the 10 surface, invertebrate forage species are not likely adversely affected by Seabrook operations, 11 and monitoring data show similar trends at nearfield and farfield stations prior to and during 12 operations.

13 D-1.3.3.4 Atlantic herring (Clupea harengus) (Juvenile and Adult) 14 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile and adult 15 Atlantic herring EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed Atlantic 16 herring in 1-10 percent of trawling samples, greater than 10 percent of gill net samples, and in 17 1-10 percent of seine pull samples (Table D-1-2).

18 Species Description. Adult Atlantic herring are pelagic, schooling fish that inhabit both the 19 eastern and western Atlantic Ocean (Stevenson and Scott, 2005). Juveniles migrate nearshore 20 to further offshore seasonally, whereas adult Atlantic herring migrate north-south along the U.S.

21 and Canadian coasts for feeding, spawning, and overwintering.

22 Larvae develop into juveniles in the spring, at approximately 1.6-2.2 in. (40-55 millimeters 23 (mm)) length (Stevenson and Scott, 2005). Schooling behavior begins once Atlantic herring 24 develop into juveniles (Gallego and Heath, 1994). NOAAs Northeast Fishery Science Center 25 (NEFSC) captured juveniles in waters from 35-54 degrees Fahrenheit (2-12 degrees Celsius) 26 in the spring and from 41-63 degrees Fahrenheit (5-17 degrees Celsius) in the fall, during 27 bottom trawl surveys from the Gulf of Maine to Cape Hatteras (Stevenson and Scott, 2005).

28 Adults occurred in waters from 35-55 degrees Fahrenheit (2-13 degrees Celsius) in the spring 29 and from 39-61 degrees Fahrenheit (4-16 degrees Celsius) in the fall (Stevenson and Scott, 30 2005).

31 Juvenile and adult Atlantic herring are opportunistic feeders and prey on zooplankton. The most 32 common prey items for juveniles include copepods, decapods larvae, barnacle larvae, 33 cladocerans, and molluscan larvae (Sherman and Perkins, 1971 in Stevenson and Scott 2005).

34 Common prey items for adults include euphausiids, chaetognaths, and copepods (Bigelow and 35 Schroeder, 1953; Maurer and Bowman, 1975 in Stevenson and Scott 2005). Adults also prey 36 upon fish eggs and larvae, including larval Atlantic cod, herring, sand lance, and silversides 37 (Munroe, 2002; Stevenson and Scott, 2005).

38 Atlantic herring are an important component of the Gulf of Maine food web and are preyed upon 39 throughout their life cycle (Stevenson and Scott, 2005). Predators include a variety of fish (such 40 as Atlantic cod, silver hake, thorny skate, bluefish, goosefish, weakfish, summer flounder, white 41 hake, Atlantic halibut, red hake, and northern shortfin squid), marine mammals, and sea birds 42 (Stevenson and Scott, 2005).

D-1-39

Appendix D-1 1 Status of the Fishery. In U.S. waters, NEFMC manage Atlantic herring as a single stock 2 (Stevenson and Scott, 2005). In 2009, NEFMC did not consider Atlantic herring overfished 3 (NMFS, 2010b).

4 Entrainment and Impingement. Although NMFS has not designated EFH for Atlantic herring 5 eggs and larvae, entrainment and impingement can adversely affect recruitment of juveniles 6 and adults. NAI (2010) did not observe entrainment of Atlantic herring eggs from 1990-2009.

7 Entrainment of Atlantic herring larvae varied from 0.1 million in 1994 to 28.2 million in 2008 8 (NAI, 2010). Annual average entrainment of Atlantic herring larvae was 9.6 million per year 9 from 1990-2009 (Table D-1-5). Atlantic herring larvae comprised approximately 3.6 percent of 10 the total fish larvae entrained at Seabrook from 1990-2009.

11 Impingement of Atlantic herring varied from 0 in 1994-1995 to 582 in 1998 (NAI, 2010). Annual 12 average impingement was 187 fish per year from 1994-2009 (Table D-1-6). Atlantic herring 13 comprised less than 1 percent of all impinged fish at Seabrook from 1994-2009.

14 Because entrainment and impingement were relatively low for Atlantic herring compared to 15 other species at Seabrook, the NRC staff concludes that entrainment and impingement are not 16 likely to adversely affect EFH for juvenile and adult Atlantic herring during the remainder of the 17 facilitys operating license or during the proposed license renewal term.

18 Thermal Effects. Seabrooks thermal discharges may reduce available habitat to juvenile and 19 adult Atlantic herring. The habitat most likely affected by the thermal plume would be the upper 20 water column (within 10-16 ft (3-5 m) of the ocean surface) in the immediate vicinity of the 21 discharge. At the surface, Padmanabhan and Hecker (1991) observed a temperature rise of 3 22 degrees Fahrenheit (1.7 degrees Celsius) or more in a 32-ac (12.9-ha) area surrounding the 23 discharge. Seabrooks NPDES permit limits the rise in monthly mean temperature to 5 degrees 24 Fahrenheit in the near field jet mixing region, or within waters less than 3.3 ft (1 m) from the 25 surface. Adult and juvenile Atlantic herring are most common near Seabrook from April-May, 26 when the surface temperature near Seabrook ranges from 41-51 degrees Fahrenheit (5-10.7 27 degrees Celsius) and from October-December, when the surface temperature ranges from 42-28 57.7 degrees Fahrenheit (5.6-14.3 degrees Celsius) (NAI, 2001). NEFSC trawl surveys 29 captured juveniles in waters up to 54 degrees Fahrenheit (12 degrees Celsius) in the spring and 30 63 degrees Fahrenheit (17 degrees Celsius) in the fall and adults up to 55 degrees Fahrenheit 31 (13 degrees Celsius) in the spring and up to 61 degrees Fahrenheit (16 degrees Celsius) in the 32 fall (Stevenson and Scott, 2005). With a temperature rise of 3-5 degrees Fahrenheit (1.7-2.8 33 degrees Celsius), the thermal plume near the surface could slightly exceed the typical range of 34 temperature that Atlantic herring juveniles and adults inhabit. The habitat affected at the 35 surface would likely be 32 ac (12.9 ha) or less (Padmanabhan and Hecker, 1991). Therefore, 36 the NRC staff concludes that the increased temperatures at Seabrook may have a minimal 37 adverse effect on EFH for adult and juvenile Atlantic herring during the remainder of the facilitys 38 operating license or during the proposed license renewal term.

39 Loss of Forage Species. Juvenile and adult Atlantic herring are opportunistic feeders and prey 40 on a wide variety of zooplankton. Adults prey upon fish eggs and larvae, including larval 41 Atlantic cod, herring, sand lance, and silversides (Munroe, 2002; Stevenson and Scott, 2005).

42 NextEras monitoring studies show relatively similar trends prior to and during operations at 43 nearfield and farfield sampling sites for the zooplankton (NAI, 2010). American sand lance 44 larvae, a common prey item for Atlantic herring, were the second most commonly entrained 45 larval species, comprising 10 percent of all entrained larvae (NAI, 2010) (Table D-1-5). Other 46 common larval prey, such as Atlantic herring and Atlantic cod larvae, comprised approximately D-1-40

Appendix D-1 1 1 percent or less of the total fish larvae entrained at Seabrook. The NRC staff concludes that 2 the potential loss of forage species at Seabrook is not likely to adversely affect EFH for adult 3 and juvenile Atlantic herring during the remainder of the facilitys operating license or during the 4 proposed license renewal term. This conclusion is based on the fact that Atlantic herring prey 5 upon a wide variety of fish larvae, and monitoring studies suggest that zooplankton abundance 6 has not been adversely affected by Seabrook operations.

7 Loss of Habitat-forming Species. Adult and juvenile Atlantic herring are primarily pelagic 8 (Stevenson and Scott, 2005), suggesting that they rarely use benthic habitats such as kelp and 9 shellfish beds. Therefore, the NRC staff concludes that the potential loss of habitat-forming 10 species is not likely to adversely affect Atlantic herring during the remainder of the facilitys 11 operating license or during the proposed license renewal term.

12 Combined Impacts (Monitoring Data). NextEra monitored the abundance of juvenile and adult 13 Atlantic herring prior to and during operations at sampling sites in Hampton-Seabrook Estuary 14 near a previous discharge location and at sites further away. Monitoring data indicate that the 15 abundance of juvenile and adult Atlantic herring decreased at both nearfield and farfield 16 sampling sites (Table D-1-11). Because NAI (2010) observed similar trends at all sampling 17 sites, these monitoring results suggest that Seabrook operations have not adversely affected 18 EFH for adult and juvenile Atlantic herring.

19 Conclusion. Because of the observations above, and because the thermal plume could 20 increase the temperature near the surface to above the temperature range that Atlantic herring 21 typically inhabit, the NRC staff concludes that Seabrook operations may have a minimal 22 adverse effect on EFH for adult and juvenile Atlantic herring.

23 D-1.3.3.5 Atlantic mackerel (Scomber scombrus) (All Life Stages) 24 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 25 and adult Atlantic mackerel EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) 26 observed Atlantic mackerel eggs and larvae in greater than 10 percent of ichthyoplankton tows, 27 juveniles and adults in less than 1 percent of trawling samples, juveniles and adults in greater 28 than 10 percent of gill net samples, and juveniles and adults in less than 1 percent of seine pull 29 samples (Table D-1-2).

30 Species Description. Atlantic mackerel are pelagic, schooling fish that inhabit the western 31 Atlantic Ocean from the Gulf of St. Lawrence to North Carolina (Studholme et al., 1999). Adults 32 are highly mobile.

33 In reviewing multiple studies, Studholme et al. (1999) indicated that the age of maturation varies 34 from 1.7-3 years of age, depending on the location, size of the year class, and size of the adult 35 stock. In the Gulf of Maine, females spawn from mid-April-June as they migrate from the south 36 (Berrien, 1982 in Studholme et al. 1999). The Gulf of Maine is not one of the more important 37 spawning grounds (Sette, 1950 in Studholme et al. 1999). Eggs are pelagic and float in the 38 upper 33-49 ft (10-15 m) of surface waters (Studholme et al., 1999). NEFSC collected eggs 39 near the surface at temperatures ranging from 41-73 degrees Fahrenheit (5-23 degrees 40 Celsius) and larvae from 43-72 degrees Fahrenheit (6-22 degrees Celsius) as part of the 41 Marine Resources Monitoring, Assessment, and Prediction (MARMAP) offshore ichthyoplankton 42 survey.

43 Juveniles exhibit schooling behavior at about 1.2-2 in. (30-50 mm) (Sette, 1943 in Studholme 44 et al. 1999). NEFSC captured juveniles from 39-72 degrees Fahrenheit (4-22 degrees Celsius)

D-1-41

Appendix D-1 1 and adults from 39-61 degrees Fahrenheit (4-16 degrees Celsius) during 1963-1997 bottom 2 trawl surveys. Overholtz and Anderson (1976 in Studholme et al. 1999) conducted field studies 3 that indicated that adult Atlantic mackerel are intolerant of temperatures greater than 4 61 degrees Fahrenheit (16 degrees Celsius).

5 Atlantic mackerel are opportunistic and filter feed or ingest prey. Larvae feed on copepod 6 nauplii, copepods, and fish larvae (Studholme et al., 1999). Both juveniles and adults prey on a 7 variety of crustaceans, although adults consume a wider variety of prey sizes and items, 8 including fish. Peterson and Ausubel (1984) determined that fish greater than 0.2 in. (5 mm) 9 feed on copepodites of Acartia and Temora, and fish greater than 0.24 in. (6 mm) feed on adult 10 copepods.

11 Atlantic mackerel is prey to a wide variety of fish, sharks, squid, whales, dolphins, seals, 12 porpoises. Common fish predators include other mackerel, dogfish, tunas, bonito, striped bass, 13 Atlantic cod, swordfish, silver hake, red hake, bluefish, pollock, white hake, goosefish, and 14 weakfish (Studholme et al., 1999).

15 Status of the Fishery. In U.S. waters, MAFMC and NFMS manage Atlantic mackerel as a single 16 stock (Studholme et al., 1999). In 2009, MAFMC did not consider Atlantic mackerel overfished 17 (NMFS, 2010b).

18 Entrainment and Impingement. Entrainment of Atlantic mackerel eggs varied from 0 in 1994 to 19 673.1 million in 1991 (NAI, 2010). Annual average entrainment of Atlantic mackerel eggs was 20 191.5 million per year from 1990-2009 (Table D-1-4). Atlantic mackerel eggs comprised 21 approximately 21.3 percent of the total fish eggs entrained at Seabrook from 1990-2009.

22 Entrainment of Atlantic mackerel larvae varied from 0 in several years to 25.7 million in 2009 23 (NAI, 2010). Annual average entrainment of Atlantic mackerel larvae was 2.6 million per year 24 from 1990-2009 (Table D-1-5). Atlantic mackerel larvae comprised approximately 1 percent of 25 the total fish larvae entrained at Seabrook from 1990-2009.

26 Impingement of Atlantic mackerel varied from 0 in several years to 4 in 2004-2005 (NAI, 2010).

27 Annual average impingement was less than 3 fish per year from 1994-2009 (Table D-1-6).

28 Atlantic mackerel comprised less than 1 percent of all impinged fish at Seabrook from 1994-29 2009.

30 Entrainment of Atlantic mackerel larvae and impingement of Atlantic mackerel is small 31 compared to other species impinged at Seabrook. However, Atlantic mackerel is the second 32 most entrained egg species, comprising 21.3 percent of the total fish eggs entrained at 33 Seabrook. Therefore, the NRC staff concludes that entrainment of Atlantic mackerel eggs may 34 have minimal adverse effects on EFH for Atlantic mackerel during the remainder of the facilitys 35 operating license or during the proposed license renewal term. Effects would likely be minimal 36 since the amount of water (or habitat) entrained in the Seabrook cooling system would be a very 37 small proportion of available habitat for Atlantic mackerel eggs.

38 Thermal Effects. Seabrooks thermal discharges may reduce available habitat to adult Atlantic 39 mackerel. The habitat most likely affected by the thermal plume would be the upper water 40 column (within 10-16 ft (3-5 m) of the ocean surface) in the immediate vicinity of the discharge.

41 At the surface, Padmanabhan and Hecker (1991) observed a temperature rise of 3 degrees 42 Fahrenheit (1.7 degrees Celsius) or more in a 32-ac (12.9-ha) area surrounding the discharge.

43 Seabrooks NPDES permit limits the rise in monthly mean temperature to 5 degrees Fahrenheit 44 in the near field jet mixing region, or within waters less than 3.3 ft (1 m) from the surface.

45 Atlantic mackerel are most common near Seabrook from June-November, when the surface D-1-42

Appendix D-1 1 temperature near Seabrook ranges from 46-66 degrees Fahrenheit (8-18.8 degrees Celsius) 2 (NAI, 2001). During ichthyoplankton and trawling surveys, NEFSC captured eggs, larvae, and 3 juveniles in waters up to 72 degrees Fahrenheit (22 degrees Celsius) and adults in waters up to 4 61 degrees Fahrenheit (16 degrees Celsius) (Studholme et al., 1999). With a temperature rise 5 of 3-5 degrees Fahrenheit (1.7-2.8 degrees Celsius), the thermal plume near the surface could 6 exceed the typical temperature range that adult Atlantic mackerel inhabit. The habitat affected 7 at the surface would likely be 32 ac (12.9 ha) or less (Padmanabhan and Hecker, 1991).

8 Therefore, the NRC staff concludes that the increased temperatures at Seabrook may have a 9 minimal adverse effect on EFH for adult Atlantic mackerel during the remainder of the facilitys 10 operating license or during the proposed license renewal term.

11 Loss of Forage Species. Atlantic mackerel are opportunistic feeders and prey includes 12 plankton, small crustaceans (including copepods), and some fish for larger Atlantic mackerel 13 (Studholme et al., 1999). NextEras monitoring studies show similar trends prior to and during 14 operations at nearfield and farfield sampling sites for changes in abundance, density, and 15 species composition for phytoplankton, zooplankton (including copepods and fish larvae),

16 invertebrates, and most fish species (NAI, 2010). Therefore, the NRC staff concludes that the 17 potential loss of forage species at Seabrook is not likely to adversely affect EFH for Atlantic 18 mackerel during the remainder of the facilitys operating license or during the proposed license 19 renewal term.

20 Loss of Habitat-forming Species. Adult and juvenile Atlantic herring are primarily pelagic 21 (Studholme et al., 1999), which suggests that they rarely use benthic habitats such as kelp and 22 shellfish beds. Therefore, the NRC staff concludes that the potential loss of habitat-forming 23 species is not likely to adversely affect EFH for Atlantic herring during the remainder of the 24 facilitys operating license or during the proposed license renewal term.

25 Combined Impacts (Monitoring Data). NextEra monitored the abundance of Atlantic mackerel 26 eggs, larvae, juveniles, and adults prior to and during operations at sampling sites near the 27 intake and discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). Monitoring data 28 indicate that the density of eggs and abundance of juveniles and adults increased or remained 29 the same at both nearfield and farfield sampling sites (Tables D-1-8 and D-1-10). Larval density 30 decreased at both nearfield and farfield sampling sites (Table D-1-8). Because NAI (2010) 31 found similar trends at both the nearfield and farfield sites, these monitoring results suggest that 32 Seabrook operations have not adversely affected EFH for Atlantic mackerel.

33 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 34 may have minimal adverse effects on EFH for Atlantic mackerel eggs and adults for the 35 following reasons:

36

• The thermal plume could increase the temperature near the surface to above the 37 temperature range that adult Atlantic mackerel typically inhabit.

38

• Atlantic mackerel is the second most entrained egg species, comprising 21.3 percent of 39 the total fish eggs entrained at Seabrook.

40 The NRC staff concludes that Seabrook operations are not likely to adversely affect Atlantic 41 mackerel larvae and juvenile for the following reasons:

42

• These life stages are not commonly entrained or impinged in the Seabrook cooling 43 system.

D-1-43

Appendix D-1 1

• The thermal plume would not exceed the typical temperature range that juveniles 2 inhabit.

3

• Forage species are not likely adversely affected by Seabrook operations.

4

• Monitoring data show similar trends at nearfield and farfield stations prior to and during 5 operations.

6 D-1.3.3.6 Atlantic sea scallop (Placopecten magellanicus) (All Life Stages) 7 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 8 and adult Atlantic sea scallop EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) 9 observed a relatively low density of Atlantic sea scallop larvae in zooplankton tows (geometric 10 mean density was approximately 3-4 scallops per 1,000 m3 prior to 2001 and less than 1 11 scallop per 1,000 m3 after 2001). Seabrook monitoring does not include juvenile and adult 12 Atlantic sea scallops. Seabrook observations near the intake and discharge structures suggest 13 that sea scallops are not common in this area (NAI, 2001).

14 Species Description. Atlantic sea scallops are bivalve mollusks that occur along the Canadian 15 and U.S. coasts from the Gulf of St. Lawrence south to Cape Hatteras, NC (Hart and Chute, 16 2004).

17 Sea scallops produce gametes within the first or second year and are among the most fecund of 18 bivalves (Langton et al., 1987). Spawning in Maine occurs from September-October. Eggs 19 remain demersal until they develop into larvae. The first two larval stages are pelagic and drift 20 with water currents (Hart and Chute, 2004). Larvae settle on the sea floor as spat and remain 21 there throughout adult life. Spat that land on sedentary branching plants, animals, or on any 22 other hard surface may have a higher survival rate than those that land in sandy bottom habitats 23 subject to burial (Larsen and Lee, 1978).

24 Juvenile scallops move from the original substrate on which they have settled and attach to 25 shells or bottom debris (Dow and Baird, 1960 in Hart and Chute 2004). Juveniles also swim to 26 avoid predators and other natural or human-induced disturbances. Tagging studies suggest 27 that adults remain sedentary once an aggregation has formed (Hart and Chute, 2004).

28 Sea scallops are filter feeders. Food particles filtered from water include phytoplankton, 29 microzooplankton (such as ciliated protozoa), and particles of detritus, especially during periods 30 of low phytoplankton concentrations (Shumway et al., 1987). Both fish and invertebrates prey 31 upon Atlantic sea scallops (Hart and Chute, 2004).

32 Status of the Fishery. The Atlantic sea scallop is one of the most economically important 33 species in the northeast U.S. (Hart and Chute, 2004). NEFMC manages the sea scallop fishery 34 under the Sea Scallop Management Plan. In 2009, NEFMC did not consider the sea scallop 35 fishery overfished (NMFS, 2010b).

36 Entrainment and Impingement. NAI (2010) did not monitor entrainment of invertebrate eggs 37 from 1990-2009. Entrainment of Atlantic sea scallop larvae varied from 0 in 2003 and 2006 to 38 31 million in 1996 (Table D-1-7) (NAI, 2010). Annual average entrainment of Atlantic sea 39 scallop larvae was 4.8 million per year from 1990-2009 (NAI, 2010). Atlantic sea scallop larvae 40 comprised less than 1 percent of the total invertebrate larvae entrained at Seabrook from 1990-41 2009.

D-1-44

Appendix D-1 1 Because adult Atlantic sea scallops are sessile benthic organisms, impingement is not likely, 2 and NextEra did not monitor impingement of Atlantic sea scallops.

3 Because entrainment was relatively low for Atlantic sea scallops compared to other invertebrate 4 species at Seabrook, and because impingement is not likely, the NRC staff concludes that 5 entrainment and impingement are not likely to adversely affect EFH for Atlantic sea scallops 6 during the remainder of the facilitys operating license or during the proposed license renewal 7 term.

8 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 9 available habitat to Atlantic sea scallop. Atlantic sea scallops are primarily benthic (Chute and 10 Hart, 2004), meaning that they spend most of the time residing near the seafloor. A relatively 11 small area near the discharge structure in deep water experiences increased temperatures 12 (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant thermal plume at the 13 discharge points quickly rises toward the surface, the NRC staff concludes that the heated 14 effluent from Seabrook is not likely to adversely affect EFH for Atlantic sea scallops during the 15 remainder of the facilitys operating license or during the proposed license renewal term.

16 Loss of Forage Species. Atlantic sea scallops are filter feeders, and prey includes 17 phytoplankton, microzooplankton (such as ciliated protozoa), and particles of detritus.

18 NextEras monitoring studies show relatively similar trends prior to and during operations at 19 nearfield and farfield sampling sites for plankton (NAI, 2010). Therefore, the NRC staff 20 concludes that the potential loss of forage species at Seabrook is not likely to adversely affect 21 EFH for Atlantic sea scallops during the remainder of the facilitys operating license or during 22 the proposed license renewal term.

23 Loss of Habitat-forming Species. Survival of newly settled Atlantic sea scallop appears to be 24 higher in complex habitats that include sedentary branching animals, plants, and other hard 25 surfaces (Larsen and Lee, 1978). Seabrook monitoring data indicate that the density of several 26 species of kelp has decreased at nearfield sampling stations since operations began, but 27 NextEra observed relatively similar trends for the density of benthic invertebrates at the 28 nearfield and farfield sites prior to and during operations (NAI, 2010). Because the density of 29 kelp is lower since operations began at Seabrook but Atlantic sea scallops use complex habitats 30 other than kelp, the NRC staff concludes that Seabrook operations may have minimal adverse 31 effects on habitat for newly settled Atlantic sea scallops.

32 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 33 the abundance of Atlantic sea scallop eggs, larvae, juveniles, or adults prior to and during 34 operations. However, NextEra monitoring data show relatively similar trends of benthic 35 invertebrate density prior to and during operations at sampling sites near the intake and 36 discharge structures and 3-4 mi (5-8 km) away (NAI, 2010).

37 Conclusion. Because spat appear to have higher survival rates in complex habitats, such as 38 kelp forests, and because Seabrook monitoring data suggests that operations have adversely 39 affected the density of several species of kelp, the NRC staff concludes that Seabrook 40 operations may have minimal adverse effects on juvenile sea scallops. Based on the above 41 analysis, the NRC staff concludes that Seabrook operations are not likely to adversely affect 42 EFH for eggs, larvae, and adult sea scallops for the following reasons:

43

• Entrainment and impingement are relatively low compared to other species at Seabrook.

44

• The thermal plume rises quickly to surface waters.

D-1-45

Appendix D-1 1

• Forage species are not likely to be adversely affected.

2

• Monitoring data show relatively similar trends of benthic invertebrate density prior to and 3 during operations at sampling sites near the intake and discharge structures and 3-4 mi 4 (5-8 km) away.

5 D-1.3.3.7 Atlantic Surfclam (Spisula solidissima) (Juveniles and Adults) 6 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile and adult 7 Atlantic surf clam EFH in the vicinity of Seabrook (NMFS, 2011b). Seabrook monitoring does 8 not include juvenile and adult Atlantic surf clams (NAI, 2010). NAI (2010) observed surface 9 larvae near Seabrook and the geometric mean density was approximately 350-590 clams per 10 1,000 m3 prior to 2001 and 120 clams per 1,000 m3 after 2001.

11 Species Description. Atlantic surfclams are bivalve mollusks that inhabit sandy habitats from 12 the southern Gulf of St. Lawrence to Cape Hatteras, NC (Merrill and Ropes 1969 in Cargnelli et 13 al., 1999a). Clams feed by sucking in plankton, such as diatoms and ciliates, through their 14 siphons (Cargnelli et al., 1999a). Predators include invertebrates (e.g., naticid snails, sea stars 15 (Asterias forbesi), lady crabs (Ovalipes ocellatus), Jonah crabs (Cancer borealis), and 16 horseshoe crabs (Limulus polyphemus)) and fish (e.g., haddock and Atlantic cod) (see review in 17 Cargnelli et al., 1999a).

18 Status of the Fishery. MAFMC manages the Atlantic surfclam under the Atlantic surfclam and 19 ocean quahog FMP. In 2009, MAFMC did not consider the Atlantic surfclam fishery overfished 20 (NMFS, 2010b).

21 Entrainment and Impingement. NAI (2010) did not monitor entrainment of invertebrate eggs 22 from 1990-2009. Entrainment of surf clam larvae varied from 0 in 1992 and 2006 to 175.5 23 million in 1999 (NAI, 2010). Annual average entrainment of Atlantic surf clam larvae was 48.9 24 million per year from 1990-2009 (Table D-1-7). Atlantic surf clam larvae comprised less than 25 1 percent of the total invertebrate larvae entrained at Seabrook from 1990-2009.

26 Because adult Atlantic surf clams are sessile benthic organisms, impingement is not likely, and 27 NextEra did not monitor impingement of Atlantic surf clams.

28 Because entrainment was relatively low for Atlantic surf clams compared to other invertebrate 29 species at Seabrook, and because impingement is not likely, the NRC staff concludes that 30 entrainment and impingement are not likely to adversely affect EFH for Atlantic surf clams 31 during the remainder of the facilitys operating license or during the proposed license renewal 32 term.

33 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 34 available habitat to Atlantic surfclams. Juvenile and adult Atlantic surfclams are benthic 35 (Cargnelli et al., 1999a), meaning that they spend most of the time residing near the seafloor. A 36 relatively small area near the discharge structure in deep water experiences increased 37 temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant thermal 38 plume at the discharge points quickly rises toward the surface, the NRC staff concludes that the 39 heated effluent from Seabrook is not likely to adversely affect EFH for Atlantic surfclam during 40 the remainder of the facilitys operating license or during the proposed license renewal term.

41 Loss of Forage Species. Atlantic surfclams feed on plankton, such as diatoms and ciliates.

42 NextEras monitoring studies show relatively similar trends prior to and during operations at 43 nearfield and farfield sampling sites for plankton (NAI, 2010). Therefore, the NRC staff D-1-46

Appendix D-1 1 concludes that the potential loss of forage species at Seabrook is not likely to adversely affect 2 Atlantic surfclam EFH during the remainder of the facilitys operating license or during the 3 proposed license renewal term.

4 Loss of Habitat-forming Species. Preferred habitat includes sandy bottom areas. Surfclams are 5 not dependent on kelp forests. Therefore, the NRC staff concludes that loss of kelp at 6 Seabrook is not likely to adversely affect EFH for juvenile and adult Atlantic surfclams during the 7 remainder of the facilitys operating license or during the proposed license renewal term.

8 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 9 the abundance of Atlantic surfclams prior to and during operations. However, NextEra 10 monitoring data show relatively similar trends of benthic invertebrate density prior to and during 11 operations at sampling sites near the intake and discharge structures and 3-4 mi (5-8 km) 12 away (NAI, 2010).

13 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 14 are not likely to adversely affect juvenile and adult Atlantic surfclams for the following reasons:

15

• Entrainment and impingement are relatively low compared to other species at Seabrook.

16

• The thermal plume rises quickly to surface waters.

17

• Forage species are not likely to be adversely affected.

18

• Monitoring data show relatively similar trends of benthic invertebrate density prior to and 19 during operations at sampling sites near the intake and discharge structures and 3-4 mi 20 (5-8 km) away.

21 D-1.3.3.8 Haddock (Melanogrammus aeglefinus) (Juvenile) 22 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile haddock EFH 23 in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed haddock in greater than 24 10 percent of trawling samples and less than 1 percent of gill net samples (Table D-1-2).

25 Species Description. Haddock are demersal gadids that inhabit both sides of the North Atlantic 26 Ocean (Brodziak, 2005). In the northwest Atlantic, haddock can be found from Cape May, NJ to 27 the Strait of Belle Isle, Newfoundland (Klein-MacPhee, 2002). In the U.S., two stocks of 28 haddock occurone in the Gulf of Maine and one in Georges Bank (Brodziak, 2005).

29 Larvae metamorphose into juveniles once they reach 0.8-1.2 in. (2-3 cm) (Fahay, 1983). For 30 the first 3-5 months, small juveniles live and feed in the upper part of the water column.

31 Juveniles visit the seafloor in search of prey and remain on the ocean bottom once suitable 32 habitat is located (Brodziak, 2005; Klein-MacPhee, 2002). Preferred benthic habitat includes 33 include gravel, pebbles, clay, and smooth hard sand (Klein-MacPhee, 2002), which is more 34 abundant in Georges Bank than in the Gulf of Maine (Broziak, 2005).

35 While inhabiting the upper part of the water column, small juveniles feed on phytoplankton, 36 small crustaceans (primarily copepods and euphausiids), and invertebrate eggs 37 (Brodziak, 2005; Kane, 1984). Benthic prey for larger juveniles include polychaetes, 38 echinoderms, small decapods, and small fishes (Bowman et al., 1987; Broziak, 2005).

39 Status of the Fishery. By the early 1990s, haddock experienced several decades of declining 40 spawning biomass and recruitment (Brodziak, 2005). Some considered the stock to be near D-1-47

Appendix D-1 1 collapse (Brodziak, 2005). Since 1994, fishery management measures have helped to reduce 2 fishing mortality (Brodziak, 2005). NEFMC currently manages haddock under the northeast 3 multispecies FMP. In 2009, NEFMC considered haddock overfished (NMFS, 2010b).

4 Entrainment and Impingement. Although NMFS has not designated EFH for haddock eggs and 5 larvae, entrainment and impingement can adversely affect recruitment of juveniles. Entrainment 6 of haddock eggs varied from 0 in several years to 7.4 million in 1992 (NAI, 2010). Annual 7 average entrainment of haddock eggs was 0.4 million per year from 1990-2009 (Table D-1-4).

8 Entrainment of 100,000 haddock larvae occurred in 1992 and 2005. NAI (2010) did not observe 9 entrainment of haddock larvae in any other year from 1990-2009 (Table D-1-5). Haddock eggs 10 and larvae comprised less than 1 percent of the total fish eggs and larvae entrained at 11 Seabrook from 1990-2009.

12 Impingement of haddock varied from 0 in several years to 397 in 1996 (NAI, 2010). Annual 13 average impingement was 28 fish per year from 1994-2009 (Table D-1-6). Haddock comprised 14 less than 1 percent of all impinged fish at Seabrook from 1994-2009.

15 Because entrainment and impingement were relatively low for haddock compared to other 16 species at Seabrook, the NRC staff concludes that entrainment and impingement are not likely 17 to adversely affect EFH for haddock during the remainder of the facilitys operating license or 18 during the proposed license renewal term.

19 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 20 available habitat to juvenile haddock. Young juvenile haddock remain pelagic for 3-5 months, 21 at which point they travel to the seafloor in search of food and remain within this benthic habitat.

22 A relatively small area near the discharge structure in deep water experiences increased 23 temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant thermal 24 plume at the discharge points quickly rises toward the surface, the NRC staff concludes that the 25 heated effluent from Seabrook is not likely to adversely affect EFH for juvenile haddock during 26 the remainder of the facilitys operating license or during the proposed license renewal term.

27 Loss of Forage Species. Juvenile haddock feed on a variety of organisms, including 28 phytoplankton, copepods, euphausiids, invertebrate eggs, polychaetes, echinoderms, small 29 decapods, and small fishes (Bowman et al., 1987; Broziak, 2005; Kane, 1984). NextEras 30 monitoring studies show relatively similar trends prior to and during operations at nearfield and 31 farfield sampling sites for the abundance, density, and species composition of phytoplankton, 32 zooplankton (including copepods), invertebrates, and most fish species (NAI, 2010). Therefore, 33 the NRC staff concludes that the potential loss of forage species at Seabrook is not likely to 34 adversely affect EFH for juvenile haddock during the remainder of the facilitys operating license 35 or during the proposed license renewal term.

36 Loss of Habitat-forming Species. Juvenile haddock do not use kelp habitats (Broziak, 2005).

37 Therefore, loss of kelp due to Seabrook operations are not likely to adversely affect EFH for 38 juvenile haddock.

39 Combined Impacts (Monitoring Data). Seabrook monitoring data does not provide data specific 40 to the abundance of juvenile haddock prior to and during operations (NAI, 2010).

41 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 42 are not likely to adversely affect juvenile haddock or its habitat for the following reasons:

43

• Impingement and entrainment are relatively low for haddock.

D-1-48

Appendix D-1 1

• The thermal plume rises quickly to surface waters 2

• Forage species are not likely to be adversely affected by Seabrook operations.

3

• Preferred habitat does not include kelp or shellfish beds.

4 D-1.3.3.9 Monkfish/Goosefish (Lophius americanus) (All Life Stages) 5 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 6 and adult goosefish EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 7 goosefish eggs in less than 1 percent of ichthyoplankton tows, goosefish larvae in 1-10 percent 8 of ichthyoplankton tows, juveniles and adults in 1-10 percent of trawling samples, and juveniles 9 and adults in less than 1 percent of gill net samples (Table D-1-2).

10 Species Description. Goosefish are large, slow-growing benthic fish (Steimle et al., 1999a). In 11 the Gulf of Maine, goosefish larger than 7.9 in. (20 cm) move offshore in the winter and spring to 12 avoid cold coastal conditions, whereas smaller goosefish migrate offshore in the fall (Hartley, 13 1995 in Steimle et al. 1999a).

14 Adults mature at approximately 4 years for males and 5 years for females (Almeida et al., 1995).

15 Spawning occurs from May-June in the Gulf of Maine (Hartley, 1995 in Steimle et al. 1999a).

16 Females shed relatively large eggs (0.6-0.7 in. (1.6-1.8 mm)) within buoyant, ribbon-like, 17 non-adhesive, mucoid veils or rafts (Martin and Drewry, 1978 in Steimle et al. 1999a). Egg veils 18 float on the surface (Steimle et al., 1999a). Larvae are also pelagic. Juveniles settle to the 19 bottom of the ocean and remain demersal as adults. Young juveniles often hide from predators 20 within algae covered rocks. Adults prefer open sandy bottoms where they can partially bury 21 themselves and then ambush prey (Steimle et al., 1999a).

22 Prey varies depending on lifestage. Larval prey includes zooplankton, such as copepods, 23 crustacean larvae, and chaetognaths (Bigelow and Schroeder, 1953). Small juveniles eat 24 pelagic fish but switch to invertebrates, especially crustaceans, once settling on the seafloor 25 (Steimle et al., 1999a). Larger juveniles and adults consume more fish than invertebrates 26 (Armstrong et al., 1996). NEFSC analyzed the stomach contents of goosefish and primary prey 27 included crustaceans, squid, and fish. Common fish prey include spiny dogfish (Squalus 28 acanthias), skates (Raja spp.), eels, sand lance, herring, Atlantic menhaden (Brevoortia 29 tyrannus), smelt (Osmeridae), mackerel (Scomber spp.), weakfish (Cynoscion regalis), cunner, 30 tautog (Tautoga onitis), black sea bass (Centropristis striata), butterfish, pufferfish, sculpins, sea 31 raven (Hemitripterus americanus), searobins (Prionotus spp.), silver hake (Merluccius 32 bilinearis), Atlantic tomcod (Microgadus tomcod), cod, haddock, hake (Urophycis spp.), witch 33 and other flounders, and other goosefish (Bigelow and Schroeder, 1953; Steimle et al., 1999a).

34 Status of the Fishery. In U.S. waters, NEFMC manages goosefish under the northeast 35 multispecies FMP. In 2009, NMFS (2010b) reported that goosefish was not overfished.

36 Entrainment and Impingement. Entrainment of goosefish eggs varied from 0 in most years to 37 0.9 million in 1998 and 2000 (NAI, 2010). Annual average entrainment of goosefish eggs was 38 0.1 million per year from 1990-2009 (Table D-1-4). Entrainment of goosefish larvae varied from 39 0 in most years to 2 million in 2000 (NAI, 2010). Annual average entrainment of goosefish 40 larvae was 0.1 million per year from 1990-2009 (Table D-1-5). Goosefish eggs and larvae 41 comprised less than 1 percent of the total fish eggs and larvae entrained at Seabrook from 42 1990-2009.

D-1-49

Appendix D-1 1 Impingement of goosefish varied from 0 in several years to 59 in 2001 (NAI, 2010). Annual 2 average impingement was 10 fish per year from 1994-2009 (Table D-1-6). Goosefish 3 comprised less than 1 percent of all impinged fish at Seabrook from 1994-2009.

4 Because entrainment and impingement were relatively low for goosefish compared to other 5 species at Seabrook, the NRC staff concludes that entrainment and impingement are not likely 6 to adversely affect EFH for goosefish during the remainder of the facilitys operating license or 7 during the proposed license renewal term.

8 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 9 available habitat to juvenile or adult goosefish. Seabrooks thermal discharge may slightly 10 reduce available habitat to goosefish eggs and larvae.

11 Goosefish eggs and larvae are pelagic (Steimle et al., 1999a). Scott and Scott (1988 in Steimle 12 et al., 1999a) reported 63-64 degrees Fahrenheit (17-18 degrees Celsius) as the upper 13 temperature limit for normal egg hatching. NEFSC MARMAP ichthyoplankton surveys collected 14 most larvae from 52-59 degrees Fahrenheit (11-15 degrees Celsius), but as high as 68 15 degrees Fahrenheit (20 degrees Celsius) (Steimle et al., 1999a). Surface waters near the 16 thermal plume typically range as high as 65.8 degrees Fahrenheit (18.8 degrees Celsius) (NAI, 17 2001). With a temperature rise of 3-5 degrees Fahrenheit (1.7-2.8 degrees Celsius), the 18 thermal plume near the surface could exceed the typical range of temperatures that goosefish 19 eggs and larvae inhabit. The habitat affected at the surface would likely be 32 ac (12.9 ha) or 20 less (Padmanabhan and Hecker, 1991).

21 Adult and juvenile goosefish are primarily benthic, meaning that they spend most of the time 22 residing near the seafloor (Steimle et al. 1999a). A relatively small area near the discharge 23 structure in deep water experiences increased temperatures (NAI, 2001; Padmanabhan and 24 Hecker, 1991).

25 Because the thermal plume could exceed the typical range of temperatures that larvae inhabit, 26 the NRC staff concludes that the heated thermal effluent may have minimal adverse effects on 27 Atlantic cod larvae. Because the buoyant thermal plume at the discharge points quickly rises 28 toward the surface, the NRC staff concludes that the heated effluent from Seabrook is not likely 29 to adversely affect EFH for goosefish during the remainder of the facilitys operating license or 30 during the proposed license renewal term.

31 Loss of Forage Species. Goosefish feed on a variety of organisms, including zooplankton, 32 invertebrates, and several fish species (Bigelow and Schroeder, 1953; Steimle et al., 1999a).

33 NextEras monitoring studies show relatively similar trends prior to and during operations at 34 nearfield and farfield sampling sites for the abundance, density, and species composition of 35 zooplankton, invertebrates, and most fish species (NAI, 2010). Therefore, the NRC staff 36 concludes that the potential loss of forage species at Seabrook is not likely to adversely affect 37 EFH for goosefish during the remainder of the facilitys operating license or during the proposed 38 license renewal term.

39 Loss of Habitat-forming Species. Newly settled juveniles may hide within algae covered rocks 40 (Steimle et al., 1999a). Seabrook monitoring data indicate that the density of several species of 41 kelp has decreased at nearfield sampling stations since operations began (NAI, 2010).

42 Therefore, Seabrook operations may have minimal adverse effects on juvenile goosefish 43 habitat. Effects would likely be minimal because juvenile goosefish would likely inhabit algae 44 (other than kelp) that have not declined near Seabrook (NAI, 2001).

D-1-50

Appendix D-1 1 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 2 the density or abundance of goosefish eggs, larvae, juveniles, or adults prior to and during 3 operations (NAI, 2010).

4 Conclusion. Because the thermal plume could exceed the typical range of temperatures that 5 eggs and larvae inhabit, and because juveniles may use algal habitats that have declined near 6 Seabrook since operations began, the NRC staff concludes that Seabrook may have minimal 7 adverse effects on EFH for goosefish eggs, larvae, and juveniles near Seabrook. Based on the 8 above analysis, Seabrook is not likely to affect goosefish adults or its habitat because 9 entrainment and impingement are relatively low compared to other species at Seabrook, the 10 thermal plume rises quickly to surface waters, and forage species are not likely to be adversely 11 affected.

12 D-1.3.3.10 Ocean pout (Macrozoarces americanus) (All Life Stages) 13 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 14 and adult ocean pout EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 15 ocean pout larvae in 1-10 percent of ichthyoplankton tows, juveniles and adults in greater than 16 10 percent of trawling samples, and juveniles and adults in less than 1 percent of gill net 17 samples (Table D-1-2).

18 Species Description. Ocean pout inhabit the Atlantic continental shelf of North America and are 19 common off the coast of southern New England (Chang, 1990). Ocean pout are benthic and 20 use both open and rough habitats (Steimle et al., 1999b).

21 In the fall, ocean pout spawn in rock crevices, man-made artifacts, or other protected areas 22 where they lay eggs in nests (Steimle et al., 1999b). Eggs remain demersal, and nests are 23 guarded by one or both parents (Bigelow and Schroeder, 1953). Once hatched, larvae 24 generally remain near or at the bottom of the seafloor (Bigelow and Schroeder, 1953).

25 Juveniles and adults are also demersal. Bigelow and Schroeder (1953) reported that juveniles 26 occur in shallow coastal waters around rocks and attached algae and in rivers with saline 27 bottom waters in the Gulf of Maine. Juveniles may also use scallop or quahog shells for cover.

28 Adults use a variety of habitats including rocky crevices, soft bottom habitats, gravel covered 29 areas, and shellfish beds (Steimle et al., 1999b).

30 Ocean pout prey on benthic organisms in soft sandy bottom habitats either by sorting mouthfuls 31 of sediments for infaunal species (MacDonald, 1983) or by ambushing prey (Auster et al.,

32 1995). Sedberry (1983 in Steimle et al. 1999b) found that juveniles feed on gammarid 33 amphipods and polychaetes. Adults prey on a variety of benthic invertebrates, such as 34 polychaetes, mollusks, crustaceans, and echinoderms (see review in Steimle et al., 1999b).

35 Langton and Watling (1990 in Steimle et al. 1999b) reported that ocean pout primarily eat 36 bivalve mollusks off the coast of southern Maine. Ocean pout and American plaice may 37 compete for prey in the Gulf of Maine (MacDonald and Green, 1986). Predators of juvenile 38 ocean pout include squid, spiny dogfish, sea raven, cod, barndoor skate (Raja laevis), harbor 39 seals, and cormorants (Steimle et al., 1999).

40 Status of the Fishery. NEFMC currently manages ocean pout as two stocks, one in northern 41 Gulf of Maine and one south of this area (Wigley, 1998). In 2009, NEFMC reported that ocean 42 pout was not overfished (NMFS, 2010b).

43 Entrainment and Impingement. NAI (2010) did not observe entrainment of ocean pout eggs 44 from 1990-2009 (Table D-1-4). Seabrook entrained less than 10,000 ocean pout larvae in 2003 D-1-51

Appendix D-1 1 (NAI, 2010). NAI (2010) did not observe entrainment of ocean pout larvae during any other year 2 from 1990-2009 (Table D-1-5).

3 Impingement of ocean pout varied from 0 in several years to 21 in 2001 (NAI, 2010). Annual 4 average impingement was 4 fish per year from 1994-2009 (Table D-1-6). Ocean pout 5 comprised less than 1 percent of all impinged fish at Seabrook from 1994-2009.

6 Because entrainment and impingement were relatively low for ocean pout compared to other 7 species at Seabrook, the NRC staff concludes that entrainment and impingement are not likely 8 to adversely affect EFH for ocean pout during the remainder of the facilitys operating license or 9 during the proposed license renewal term.

10 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 11 available habitat to eggs, larvae, juvenile, or adult ocean pout. Ocean pout are primarily benthic 12 (Steimle et al., 1999b), meaning that they spend most of the time residing near the seafloor. A 13 relatively small area near the discharge structure in deep water experiences increased 14 temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant thermal 15 plume at the discharge points quickly rises toward the surface, the NRC staff concludes that the 16 heated effluent from Seabrook is not likely to adversely affect EFH for all life stages of ocean 17 pout during the remainder of the facilitys operating license or during the proposed license 18 renewal term.

19 Loss of Forage Species. Ocean pout feed on a variety of invertebrates, including gammarid 20 amphipods, polychaetes, mollusks, echinoderms, and other crustaceans (Langton and Watling, 21 1990 in Steimle et al. 1999b; Steimle et al., 1999b). NextEras monitoring studies show 22 relatively similar trends prior to and during operations at nearfield and farfield sampling sites for 23 the abundance, density, and species composition of zooplankton and benthic invertebrates 24 (NAI, 2010). Therefore, the NRC staff concludes that the potential loss of forage species at 25 Seabrook is not likely to adversely affect EFH for ocean pout during the remainder of the 26 facilitys operating license or during the proposed license renewal term.

27 Loss of Habitat-forming Species. Juveniles may use habitats with algae, and both juveniles and 28 adults may use shellfish beds (Bigelow and Schroeder, 1953; Steimle et al., 1999b). Seabrook 29 monitoring data indicate that the density of several species of kelp has decreased at nearfield 30 sampling stations since operations began, but Seabrook observed similar trends in the density 31 of benthic invertebrates at the nearfield and farfield sites prior to and during operations (NAI, 32 2010). Because the density of kelp is lower since operations began at Seabrook, but juvenile 33 ocean pout use complex habitats other than kelp, the NRC staff concludes that Seabrook 34 operations may have minimal adverse effects on juvenile ocean pout and its habitat. Because 35 Seabrook operations have not adversely affected the density or species diversity of benthic 36 invertebrates, including shellfish beds, Seabrook operations are not likely to adversely affect 37 adult ocean pout habitat.

38 Combined Impacts (Monitoring Data). NextEra monitored the abundance of ocean pout eggs, 39 larvae, juveniles, and adults prior to and during operations at sampling sites near the intake and 40 discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). Icthoplankton trawls did 41 not capture ocean pout eggs and captured larvae in less than 10 percent of all samples 42 (Table D-1-2). Monitoring data indicate that the abundance of juveniles and adult increased or 43 remained the same at both nearfield and farfield sampling sites (Table D-1-9). Because NAI 44 (2010) found similar trends at both the nearfield and farfield sites, these monitoring results 45 suggest that Seabrook operations have not adversely affected EFH for ocean pout.

D-1-52

Appendix D-1 1 Conclusion. Because juveniles may use algal habitats and other complex habitats, and 2 because the density of several kelp species has declined near Seabrook since operations 3 began, NRC staff concludes that Seabrook may have minimal adverse effects on juvenile ocean 4 pout and its habitat near Seabrook. Based on the above analysis, Seabrook is not likely to 5 affect EFH for ocean pout eggs, larvae, or adults for the following reasons:

6

• Entrainment and impingement are relatively low compared to other species at Seabrook.

7

• The thermal plume rises quickly to surface waters.

8

• Forage species and shellfish beds are not likely to be adversely affected by Seabrook 9 operations.

10

• Monitoring data indicate that the abundance trends for ocean pout were similar at 11 nearfield and farfield sties.

12 D-1.3.3.11 Pollock (Pollachius virens) (Juvenile) 13 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile pollock EFH in 14 the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed pollock in greater than 15 10 percent of trawling samples, in greater than 10 percent of gill net samples, and in 1-16 10 percent of seine pull samples (Table D-1-2) (NAI, 2010).

17 Species Description. Pollock are gadoids that occur on both sides of the North Atlantic 18 (Cargnelli et al., 1999). Within the western Atlantic, pollock are relatively common within the 19 Gulf of Maine (Cargnelli et al., 1999).

20 Juveniles migrate to and from offshore waters to nearshore habitats, such as the rocky subtidal 21 and intertidal, until they remain offshore as adults (Cargnelli et al., 1999). Juveniles use a wide 22 variety of habitats, including sand, mud, or rocky bottom and vegetation (Hardy, 1978 in 23 Cargnelli et al. 1999). NEFSC trawl surveys captured juveniles at temperatures ranging from 24 34-64 degrees Fahrenheit (1-18 degrees Celsius).

25 Juveniles consume crustaceans, such as euphausiids and mollusks, and fish (Bowman and 26 Michaels, 1984). Ojeda and

Dearborn (1991) determined that fish,

such as young Atlantic 27 herring, dominated the diet of subtidal juveniles in the Gulf of Maine.

28 Status of the Fishery. NEFMC manages pollock as a single unit under the northeast 29 multispecies FMP. In 2009, NEFMC determined that pollock was not overfished (NMFS, 30 2010b).

31 Entrainment and Impingement. Although NMFS has not designated EFH for pollock eggs and 32 larvae, entrainment and impingement can adversely affect recruitment of juveniles. Entrainment 33 of pollock eggs varied from 0 in 1990 to 8.5 million in 2007 (NAI, 2010). Annual average 34 entrainment of pollock eggs was 1.4 million per year from 1990-2009 (Table D-1-4).

35 Entrainment of pollock larvae varied from 0 in most years to 0.8 million in 2007 (NAI, 2010).

36 Annual average entrainment of pollock larvae was 0.2 million per year from 1990-2009 37 (Table D-1-5). Pollock eggs and larvae comprised less than 1 percent of the total fish eggs and 38 larvae entrained at Seabrook from 1990-2009.

39 Impingement of pollock varied from 72 in 2006 to 11,392 in 1999 (NAI, 2010). Annual average 40 impingement was 1,273 fish per year from 1994-2009 (Table D-1-6). Pollock was the sixth D-1-53

Appendix D-1 1 most commonly impinged fish species and comprised 6.1 percent of all impinged fish at 2 Seabrook from 1994-2009.

3 Entrainment of pollock is small compared to other species entrained at Seabrook. However, 4 pollock is the sixth most impinged fish species, comprising 6.1 percent of the total fish impinged 5 at Seabrook. Therefore, the NRC staff concludes that impingement may have minimal adverse 6 effects on EFH for pollock during the remainder of the facilitys operating license or during the 7 proposed license renewal term. Effects would likely be minimal since the amount of water (or 8 habitat) captures in the Seabrook cooling system would be a very small proportion of available 9 habitat for pollock juveniles and adults.

10 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 11 available habitat to juvenile pollock. Juvenile pollock use primarily benthic habitats in the 12 nearshore, such as rocky subtidal or intertidal area, although some may also travel throughout 13 the water column (Cargnelli et al., 1999). A relatively small area near the discharge structure in 14 deep water experiences increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991).

15 From May-June and October-December, when pollock density was highest in Seabrook 16 monitoring studies, the surface temperature reached 57.7 degrees Fahrenheit (14.3 degrees 17 Celsius) near Seabrook (NAI, 2010). NEFSC trawl surveys captured juveniles at temperatures 18 ranging from 34-64 degrees Fahrenheit (1-18 degrees Celsius). With a temperature rise of 3-5 19 degrees Fahrenheit (1.7-2.8 degrees Celsius), the thermal plume near the surface would be 20 within the typical range of temperatures that juvenile pollock inhabit. The NRC staff concludes 21 that the increased temperatures at Seabrook are not likely to adversely affect EFH for juvenile 22 pollock during the remainder of the facilitys operating license or during the proposed license 23 renewal term. This conclusion is based on the findings that the buoyant thermal plume at the 24 discharge points quickly rises toward the surface, and the temperature range within the thermal 25 plume at the surface would be within the typical range for juvenile pollock.

26 Loss of Forage Species. Juveniles consume crustaceans, such as euphausiids and mollusks, 27 and fish, such as Atlantic herring (Bowman and Michaels, 1984; Ojeda and

Dearborn,

1991).

28 NextEras monitoring studies show relatively similar trends prior to and during operations at 29 nearfield and farfield sampling sites for the abundance and density of zooplankton, benthic 30 invertebrates, and most fish species (NAI, 2010). Entrainment and impingement were relatively 31 low for Atlantic herring, primary fish prey for juvenile pollock, compared to other species at 32 Seabrook. Therefore, the NRC staff concludes that the potential loss of forage species at 33 Seabrook is not likely to adversely affect pollock during the remainder of the facilitys operating 34 license or during the proposed license renewal term.

35 Loss of Habitat-forming Species. Juveniles use a wide variety of habitats, including sand, mud, 36 or rocky bottom and vegetation (Hardy, 1978 in Cargnelli et al. 1999). Seabrook monitoring 37 data indicate that the density of several species of kelp has decreased at nearfield sampling 38 stations since operations began, but NextEra observed similar trends for the density of benthic 39 invertebrates at the nearfield and farfield sampling sites prior to and during operations (NAI, 40 2010). Because the density of kelp is lower since operations began at Seabrook, but juvenile 41 pollock use complex habitats other than kelp, the NRC staff concludes that Seabrook operations 42 may have minimal adverse effects on juvenile pollock habitat.

43 Combined Impacts (Monitoring Data). NextEra monitored the abundance of juvenile pollock 44 prior to and during operations at sampling sites near the intake and discharge structures and at 45 sites 3-4 mi (5-8 km) away and within Hampton-Seabrook Estuary (NAI, 2010). Monitoring 46 data indicate that the abundance of juvenile pollock decreased or remained the same at both D-1-54

Appendix D-1 1 nearfield and farfield sampling sites (Tables D-1-10 and D-1-11). Because NAI (2010) found 2 similar trends at both the nearfield and farfield sites, these monitoring results suggest that 3 Seabrook operations have not adversely affected EFH for juvenile pollock.

4 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook may have 5 minimal adverse effects on EFH for juvenile pollock because juveniles may use algal habitats 6 that have declined near Seabrook since operations began, and pollock is the sixth most 7 impinged fish species, comprising 6.1 percent of the total fish impinged at Seabrook. Impacts 8 would likely be minimal for the following reasons:

9

• Pollock are not commonly entrained in the Seabrook cooling system.

10

• The thermal plume rises quickly to the surface.

11

• The temperature range within the thermal plume at the surface would be within the 12 typical range for juvenile pollock.

13

• Forage species are not likely adversely affected by Seabrook operations.

14

• Monitoring data show similar trends at nearfield and farfield stations prior to and during 15 operations.

16 D-1.3.3.12 Red hake (Urophycis chuss) (All Life Stages) 17 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 18 and adult red hake EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 19 Urophycis spp. (mostly red and white (U. tenuis) hake and to a lesser extent spotted hake (U.

20 regia)) egg and larvae in greater than 10 percent of ichthyoplankton tows, juveniles and adults 21 in greater than 10 percent of trawling samples, in 1-10 percent of gill net samples, and in more 22 than 10 percent of seine pull samples (Table D-1-2).

23 Species Description. Red hake are demersal fish that occur along the U.S. and Canadian costs 24 from North Carolina to Southern Newfoundland (Sosebee, 1998). Red hake migrate seasonally 25 to various depths to inhabit waters with relatively consistent temperaturesthey migrate to 26 waters deeper than 328 ft (100 m) in the fall and waters less than 328 ft (100 m) in warmer 27 months (Steimle et al., 1999c).

28 Southern Gulf of Maine is not a common spawning ground for red hake (Steimle et al., 1999c).

29 Eggs are buoyant and float near the surface (Steimle et al., 1999c). Larvae are also pelagic 30 and inhabit the upper water column. NEFSC MARMAP ichthyoplankton surveys collected 31 larvae at temperatures ranging from 46-73 degrees Fahrenheit (8-23 degrees Celsius)(Steimle 32 et al., 1999c). Surveys indicate that larvae are more abundant in the Middle Atlantic Bight than 33 the Gulf of Maine (Steimle et al., 1999c). Juveniles remain pelagic for approximately 2 months 34 before they settle to the sea floor. Bottom trawl surveys captured juveniles in waters up to 72 35 degrees Fahrenheit (22 degrees Celsius) (Steimle et al., 1999c). Benthic habitat structure for 36 sheltersuch as sea scallop shells, Atlantic surf clams, seabed depressions, or other 37 structureis important habitat for juveniles (Steiner et al., 1982). Adult red hake commonly 38 inhabit areas with soft sediments bottoms that contain shellfish beds or depressions as well as 39 natural and artificial reefs (Steimle et al., 1999c).

40 Prey varies by life stage. Larvae consume mainly copepods and other microcrustaceans 41 (Steimle et al., 1999c). Juvenile red hake consume small benthic and pelagic crustaceans, 42 such as larval and small decapod shrimp and crabs, mysids, euphausiids, and amphipods D-1-55

Appendix D-1 1 (Steimle et al., 1999c). Similar to juveniles, adults consume crustaceans but also prey on a 2 variety of demersal and pelagic fish and squid.

3 Status of the Fishery. NEFMC manages the red hake fishery under the northeast multispecies 4 FMP. In 2009, NEFMC did not consider the red hake fishery overfished (NMFS, 2010b).

5 Entrainment and Impingement. Entrainment of red, white, and spotted hake at Seabrook was 6 recorded under a single category for Urophycis spp. (NAI, 2010). Entrainment of hake eggs 7 varied from 0.6 million in 1994 to 213.2 million in 1996 (NextEra, 2010a). Annual average 8 entrainment of hake eggs was 45.7 million per year from 1990-2009 (Table D-1-4). Hake was 9 the fourth most commonly entrained taxa, comprising 5.1 percent of all entrained fish eggs at 10 Seabrook from 1990-2009.

11 Entrainment of hake larvae varied from 0 in most years to 29.8 million in 2000 (NAI, 2010).

12 Annual average entrainment of hake larvae was 2.8 million per year from 1990-2009 13 (Table D-1-5). Hake larvae comprised 1 percent of the total fish larvae entrained at Seabrook 14 from 1990-2009.

15 Impingement of red hake varied from 1 in 1994 to 1,478 in 1996 (NAI, 2010). Annual average 16 impingement was 509 fish per year from 1994-2009 (Table D-1-6). For hakes, which included 17 red hake, white hake, and spotted hake, impingement varied from 4 in 1998 to 3,216 in 2008 18 (NAI, 2010). Annual average impingement was 866 fish per year from 1994-2009 19 (Table D-1-6). The red hake and hake categories comprised 6.5 percent of all impinged fish at 20 Seabrook from 1994-2009.

21 Because entrainment and impingement of hake were relatively common at Seabrook, the NRC 22 staff concludes that entrainment and impingement may minimal adverse effects on EFH for red 23 hake during the remainder of the facilitys operating license or during the proposed license 24 renewal term. Effects would likely be minimal since the amount of water (or habitat) captured in 25 the Seabrook cooling system would be a very small proportion of available habitat for all life 26 stages of red hake.

27 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 28 available habitat to red hake. Larvae and young juveniles inhabit pelagic waters up to 72-73 29 degrees Fahrenheit (22-23 degrees Celsius) (Steimle et al., 1999c). Surface waters near the 30 thermal plume typically range as high as 65.8 degrees Fahrenheit (18.8 degrees Celsius) (NAI, 31 2001). With a temperature rise of 3-5 degrees Fahrenheit (1.7-2.8 degrees Celsius), the 32 thermal plume near the surface would be within the typical range of temperatures that larvae 33 and young juveniles inhabit. Older juvenile and adult red hake are benthic (Steimle et al.,

34 1999c). A relatively small area near the discharge structure in deep water experiences 35 increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). The NRC staff 36 concludes that the heated effluent from Seabrook is not likely to adversely affect EFH for red 37 hake during the remainder of the facilitys operating license or during the proposed license 38 renewal term. This conclusion is based on the fact that the buoyant thermal plume at the 39 discharge points quickly rises toward the surface, and the temperature range within the thermal 40 plume at the surface would be within the typical range for larvae and young juvenile red hake.

41 Loss of Forage Species. Red hake consume a variety of prey items, including copepods, 42 shrimp, crabs, euphausiids, amphipods, and other crustaceans, and a variety of demersal and 43 pelagic fish and squid (Steimle et al., 1999c). NextEras monitoring studies show relatively 44 similar trends in abundance prior to and during operations at nearfield and farfield sampling 45 sites for zooplankton, benthic invertebrates, and most fish species (NAI, 2010). Therefore, the D-1-56

Appendix D-1 1 NRC staff concludes that the potential loss of forage species at Seabrook is not likely to 2 adversely affect EFH for red hake during the remainder of the facilitys operating license or 3 during the proposed license renewal term.

4 Loss of Habitat-forming Species. Juvenile and adult red hake commonly use shellfish bed for 5 shelter, as well as other natural and artificial structures. Seabrook observed similar trends in 6 the density of benthic invertebrates at the nearfield and farfield sites prior to and during 7 operations (NAI, 2010). Therefore, the NRC staff concludes that the potential loss of 8 habitat-forming species at Seabrook is not likely to adversely affect EFH for red hake during the 9 remainder of the facilitys operating license or during the proposed license renewal term.

10 Combined Impacts (Monitoring Data). NextEra monitored the abundance of hake eggs, 11 juveniles, and adults prior to and during operations at sampling sites near the intake and 12 discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). This category included 13 Urophycis spp. (mostly red and white hake) and to a lesser extent spotted hake (NAI, 2010).

14 Monitoring data indicate that the abundance of hake eggs, juveniles, and adults decreased at 15 both nearfield and farfield sampling sites (Tables D-1-8 and D-1-9). Because NAI (2010) found 16 similar trends at both the nearfield and farfield sites, these monitoring results suggest that 17 Seabrook operations have not adversely affected EFH for hake.

18 Conclusion. Based on the above analysis, the NRC staff concludes that entrainment and 19 impingement may have minimal adverse effects on EFH for red hake eggs, larvae, juvenile, and 20 adults during the remainder of the facilitys operating license or during the proposed license 21 renewal term because entrainment and impingement of hake were relatively common at 22 Seabrook. Impacts would likely be minimal for the following reasons:

23

• Thermal plume rises quickly to surface waters and is within the typical range of surface 24 temperatures for larvae and young juveniles.

25

• Forage species and shellfish beds are not likely to be adversely affected.

26

• Monitoring data show similar trends in the abundance of red hake at nearfield and 27 farfield sties prior to and during operations.

28 D-1.3.3.13 Scup (Stenotomus chrysops) (Juvenile and Adult) 29 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile and adult scup 30 EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed scup in 1-10 percent of 31 trawling samples and less than 1 percent of gill net samples (Table D-1-2).

32 Species Description. Scup are demersal fish that primarily occur primarily along the U.S. coast 33 from Massachusetts to South Carolina, and have been observed as far north as the Bay of 34 Fundy (Steimle et al., 1999d). Scup migrate south of New Jersey during the winter.

35 During the summer and early fall, juveniles and adults inhabit larger estuaries and coastal 36 areas. Baird (1873 in Steimle et al. 1999d) reported habitat for juveniles to include sand, 37 silty-sand, shell, mud, mussel beds, and eelgrass (Zosteria marina). Adults exhibit schooling 38 behavior and also use a variety of habitats, including open sandy bottom and structured habitats 39 such as mussel beds, reefs, or rough bottom (Steimle et al., 1999d).

40 Juveniles prey on small crustaceans, such as amphipods, polychaetes, and copepods (Steimle 41 et al., 1999d). Adults consume a variety of prey, including small zooplankton, polychaetes, 42 mollusks, other crustaceans, small squid, vegetable detritus, insect larvae, hydroids, sand D-1-57

Appendix D-1 1 dollars, and small fish (Bigelow and Schroeder, 1953; Steimle et al., 1999d). Predators of scup 2 include a variety of fish and sharks, such as bluefish (Pomatomus saltatrix), Atlantic halibut, 3 cod, striped bass (Morone saxitilus), weakfish, goosefish, silver hake, and other coastal fish 4 predators (see review in Steimle et al., 1999d).

5 Status of the Fishery. MAFMC manages the scup fishery under the summer flounder, scup, and 6 black sea bass FMP. In 2009, MAFMC did not consider the scup fishery overfished (NMFS, 7 2010b).

8 Entrainment and Impingement. Although NMFS has not designated EFH for scup eggs and 9 larvae, entrainment and impingement can adversely affect recruitment of juveniles and adults.

10 NAI (2010) did not observe scup eggs or larvae in entrainment studies from 1990-2009.

11 Impingement of scup varied from 0 in multiple years to 21 in 2005 (NAI, 2010). Annual average 12 impingement was 7 fish per year from 1994-2009 (Table D-1-6). Scup comprised less than 13 1 percent of all impinged fish at Seabrook from 1994-2009.

14 Because NAI (2010) did not observe scup entrainment, and because impingement is small 15 compared to other species entrained at Seabrook, the NRC staff concludes that entrainment 16 and impingement are not likely to adversely affect EFH for scup during the remainder of the 17 facilitys operating license or during the proposed license renewal term.

18 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 19 available habitat to juvenile or adult scup. Juvenile and adult scup are primarily benthic (Steimle 20 et al., 1999d). A relatively small area near the discharge structure in deep water experiences 21 increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant 22 thermal plume at the discharge points quickly rises toward the surface, the NRC staff concludes 23 that the heated effluent from Seabrook is not likely to adversely affect EFH for scup during the 24 remainder of the facilitys operating license or during the proposed license renewal term.

25 Loss of Forage Species. Scup consume a variety of prey including zooplankton, amphipods, 26 polychaetes, copepods, mollusks, other crustaceans, small squid, vegetable detritus, insect 27 larvae, hydroids, sand dollars, and small fish (Bigelow and Schroeder, 1953; Steimle et al.,

28 1999d). NextEras monitoring studies show relatively similar trends prior to and during 29 operations at nearfield and farfield sampling sites for the abundance, density, and species 30 composition of zooplankton, benthic invertebrates, and most fish species (NAI, 2010).

31 Therefore, the NRC staff concludes that the potential loss of forage species at Seabrook is not 32 likely to adversely affect EFH for scup during the remainder of the facilitys operating license or 33 during the proposed license renewal term.

34 Loss of Habitat-forming Species. Juvenile and adult scup use a variety of habitats, including 35 open areas and areas with structure such as mussel beds and eelgrass (Zosteria marina) 36 (Steimle et al., 1999d). Seabrook monitoring data indicate that the density of several species of 37 kelp has decreased at nearfield sampling stations since operations began, but Seabrook 38 observed similar trends in the density of benthic invertebrates at the nearfield and farfield sites 39 prior to and during operations (NAI, 2010). Because scup inhabit a wide variety of habitats and 40 kelp are not a primary or preferred habitat, the NRC staff concludes that the potential loss of 41 habitat-forming species at Seabrook is not likely to adversely affect EFH for scup during the 42 remainder of the facilitys operating license or during the proposed license renewal term.

43 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 44 the abundance of juvenile or adult scup prior to and during operations (NAI, 2010).

D-1-58

Appendix D-1 1 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 2 are not likely to adversely affect EFH for juvenile or adult scup for the following reasons:

3

• Impingement and entrainment are relatively low for scup.

4

• The thermal plume quickly rises to the surface.

5

• Forage species and shellfish beds are not likely to be adversely affected by Seabrook 6 operations.

7

• Scup use a wide variety of habitats other than kelp.

8 D-1.3.3.14 Summer flounder (Paralicthys dentatus) (Adult) 9 Designated EFH in the Vicinity of Seabrook. The NMFS has designated adult summer flounder 10 EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed summer flounder in less 11 than 1 percent of trawling samples (Table D-1-2).

12 Species Description. Summer flounder are benthic fish that occurs from Nova Scotia to Florida 13 (Packer et al., 1999). Adult summer flounder migrate seasonally, whereby summer flounder 14 normally inhabit shallow coastal and estuarine waters during summer and remain offshore 15 during the fall and winter (Lux and Nichy, 1981 in Packer et al., 1999; Packer et al., 1999).

16 Adults prefer sandy habitats. Lascara (1981 in Packer et al., 1999) showed that adults remain 17 along the vegetative perimeter of eelgrass patches and capture prey that move from within the 18 grass. Adult summer flounder are opportunistic feeders and prey upon a variety of fish and 19 crustaceans (Bigelow and Schroeder, 1953; Packer et al., 1999). Common prey items include 20 windowpane, winter flounder, northern pipefish, Atlantic menhaden, bay anchovy, red hake, 21 silver hake, scup, Atlantic silverside, American sand lance, bluefish, weakfish, mummichog, rock 22 crabs, squids, shrimps, small bivalve and gastropod mollusks, small crustaceans, marine 23 worms, and sand dollars (Packer et al., 1999). Predators of summer flounder include large 24 sharks, rays, and goosefish.

25 Status of the Fishery. MAFMC manages the summer flounder fishery under the summer 26 flounder, scup, and black sea bass FMP. In 2009, MAFMC did not consider the summer 27 flounder fishery overfished (NMFS, 2010b).

28 Entrainment and Impingement. Although NMFS has not designated EFH for summer flounder 29 eggs and larvae, entrainment and impingement can adversely affect recruitment of adults. NAI 30 (2010) did not observe summer flounder eggs in entrainment studies from 1990-2009. NAI 31 (2010) observed entrainment of less than 100,000 summer flounder larvae during 3 years from 32 1990-2009 (Table D-1-5). NAI (2010) observed three impinged fish in 1994 and four impinged 33 fish in 2006 (Table D-1-6).

34 Because entrainment and impingement of summer flounder were relatively rare at Seabrook, 35 the NRC staff concludes that entrainment and impingement are not likely to adversely affect 36 EFH for summer flounder during the remainder of the facilitys operating license or during the 37 proposed license renewal term.

38 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 39 available habitat to adult summer flounder. Summer flounder are primarily benthic (Packer et 40 al., 1999). A relatively small area near the discharge structure in deep water experiences 41 increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because the buoyant D-1-59

Appendix D-1 1 thermal plume at the discharge points quickly rises toward the surface, the NRC staff concludes 2 that the heated effluent from Seabrook is not likely to adversely affect EFH for summer flounder 3 during the remainder of the facilitys operating license or during the proposed license renewal 4 term.

5 Loss of Forage Species. Adult summer flounder are opportunistic feeders and prey upon a 6 variety of fish and crustaceans (Bigelow and Schroeder, 1953; Packer et al., 1999). NextEras 7 monitoring studies show relatively similar trends prior to and during operations at nearfield and 8 farfield sampling sites for the abundance, density, and species composition of benthic 9 invertebrates and most fish species (NAI, 2010). Therefore, the NRC staff concludes that the 10 potential loss of forage species at Seabrook is not likely to adversely affect summer flounder 11 EFH during the remainder of the facilitys operating license or during the proposed license 12 renewal term.

13 Loss of Habitat-forming Species. Adult summer flounder use open sandy areas and patches of 14 eelgrass for feeding (Packer et al., 1999). Near the intake and discharge structures, it is 15 reasonable to assume that patches of kelp may play a similar ecological role as eelgrass for 16 summer flounder to ambush predators. Seabrook monitoring data indicate that the density of 17 several species of kelp has decreased at nearfield sampling stations because operations began 18 (NAI, 2010). Because summer flounder use patches of vegetation to ambush predators, the 19 NRC staff concludes that the potential loss of habitat-forming species at Seabrook may have 20 minimal adverse effects on EFH for adult summer flounder during the remainder of the facilitys 21 operating license or during the proposed license renewal term. Effects would likely be minimal 22 since adult summer flounder inhabit a variety of habitats and vegetation other than kelp.

23 Combined Impacts (Monitoring Data). Seabrook monitoring data do not provide data specific to 24 the abundance of adult summer flounder prior to and during operations (NAI, 2010).

25 Conclusion. Because summer flounder may use algal habitats that have declined near 26 Seabrook since operations began, the NRC staff concludes that Seabrook may have minimal 27 adverse effects on EFH for summer flounder near Seabrook. Impacts would likely be minimal 28 because impingement and entrainment are relatively rare for summer flounder, the thermal 29 plume quickly rises to the surface, and forage species and shellfish beds are not likely to be 30 adversely affected by Seabrook operations.

31 D-1.3.3.15 Whiting/Silver hake (Merluccius bilinearis) (All life stages) 32 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 33 and adult silver hake EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 34 silver hake egg and larvae in greater than 10 percent of ichthyoplankton tows, juveniles and 35 adults in greater than 10 percent of trawling samples, in greater than 10 percent of gill net 36 samples, and in less than 1 percent of seine pull samples (Table D-1-2).

37 Species Description. Silver hake are schooling gadids (Lock and Packer, 2004). Two stocks 38 occur in the western Atlantic Oceanone stock ranges from the Gulf of Maine to northern 39 Georges Bank and the other stock ranges from southern Georges Bank to Cape Hatteras.

40 Coastal Gulf of Maine is a major spawning area for silver hake. Brodziak (2001) reported peak 41 spawning from July-August in the northern stock of silver hake. Eggs and newly hatched larvae 42 are pelagic (Lock and Packer, 2004). After 3-5 months, larvae descend towards benthic 43 habitats (Jeffrey and Taggart, 2000). NEFSC MARMAP ichthyoplankton surveys captured eggs D-1-60

Appendix D-1 1 at temperatures ranging from 41-73 degrees Fahrenheit (5-23 degrees Celsius) and larvae 2 from 41-66 degrees Fahrenheit (5-19 degrees Celsius) (Lock and Packer, 2004).

3 Juvenile and adult silver hake make seasonal migrations, moving offshore as water 4 temperatures decline in the fall and returning to shallow waters in spring and summer to spawn.

5 Juvenile and adult silver hake are primarily benthic but will move up into the water column for 6 feeding (Koeller et al., 1989; Lock and Packer, 2004). Lock and Packer (2004) consider silver 7 hake use and preference of various bottom habitats a future research need. NEFSC bottom 8 trawl surveys captured juveniles at temperatures ranging from 36-70 degrees Fahrenheit (2-21 9 degrees Celsius) and adults from 36-63 degrees Fahrenheit (2-17 degrees Celsius) (Lock and 10 Packer, 2004).

11 Silver hake are an important predator species due to their dominant biomass and high prey 12 consumption (Bowman, 1984; Garrison and Link, 2000). Silver hake diet varies with life stage, 13 size, sex, season, migration, spawning, and age. Larvae prey on plankton such as copepod 14 larvae and younger copepodites (Lock and Packer, 2004). Juveniles generally consume 15 euphausiids, shrimp, amphipods, and decapods (Bowman, 1984). Adults and older juveniles 16 mainly prey on schooling fish, such as young herring, mackerel, menhaden, alewives, sand 17 lance, or silversides, although crustaceans and squids are also consumed (Bowman, 1984; 18 Garrison and Link, 2000; Lock and Packer, 2004). Predators include offshore, silver, white, red, 19 and spotted hakes and to a lesser extent demersal gadids, pelagic fish species, and squids 20 (Lock and Packer, 2004).

21 Status of the Fishery. NEFMC manages the silver hake fishery. In 2009, NEFMC did not 22 consider the silver hake fishery overfished (NMFS, 2010b).

23 Entrainment and Impingement. Entrainment of silver hake eggs varied from 0.6 million in 1991 24 to 341.4 million in 2002 (NAI, 2010). Annual average entrainment of silver hake eggs was 25 81.1 million per year from 1990-2009 (Table D-1-4). Silver hake was the third most commonly 26 entrained egg species, comprising 9 percent of all entrained fish eggs at Seabrook from 27 19902009.

28 Entrainment of silver hake larvae varied from 0 in several years to 69 million in 1997 29 (NAI, 2010). Annual average entrainment of silver hake larvae was 8.1 million per year from 30 1990-2009 (Table D-1-5). Silver hake larvae was the ninth most commonly entrained larval 31 species, comprising 3 percent of the total fish larvae entrained at Seabrook from 1990-2009.

32 Impingement of silver hake varied from 0 in 1994 to 1,177 in 2002 (NAI, 2010). Annual average 33 impingement was 167 fish per year from 1994-2009 (Table D-1-6). Silver hake comprised less 34 than 1 percent of all impinged fish at Seabrook from 1994-2009.

35 Because entrainment of silver hake was relatively common at Seabrook, the NRC staff 36 concludes that entrainment may have minimal adverse effects on EFH for silver hake during the 37 remainder of the facilitys operating license or during the proposed license renewal term.

38 Effects would likely be minimal since the amount of water (or habitat) entrained in the Seabrook 39 cooling system would be a very small proportion of available habitat for silver hake eggs and 40 larvae.

41 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 42 available habitat to silver hake. NEFSC MARMAP ichthyoplankton surveys captured eggs at 43 temperatures ranging from 41-73 degrees Fahrenheit (5-23 degrees Celsius) and larvae from 44 41-66 degrees Fahrenheit (5-19 degrees Celsius) (Lock and Packer, 2004). Juveniles and D-1-61

Appendix D-1 1 adults are primarily benthic but may move into the water column for feeding (Lock and Packer, 2 2004). NEFSC bottom trawl surveys captured juveniles at temperatures ranging from 36-70 3 degrees Fahrenheit (2-21 degrees Celsius) and adults from 36-63 degrees Fahrenheit (2-17 4 degrees Celsius) (Lock and Packer, 2004). Surface waters near the thermal plume typically 5 range as high as 65.8 degrees Fahrenheit (18.8 degrees Celsius) (NAI, 2001). With a 6 temperature rise of 3-5 degrees Fahrenheit (1.7-2.8 degrees Celsius), the thermal plume near 7 the surface would be within the typical range of temperatures that eggs and juveniles inhabit.

8 However, the thermal plume may exceed the typical range of temperatures that larvae and 9 adults inhabit. A relatively small area near the discharge structure in deep water experiences 10 increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). The NRC staff 11 concludes that the heated thermal effluent from Seabrook is not likely to adversely affect EFH 12 for eggs and juveniles during the remainder of the facilitys operating license or during the 13 proposed license renewal term. This conclusion is based on the fact that the buoyant thermal 14 plume at the discharge points quickly rises toward the surface, and the temperature range within 15 the thermal plume at the surface would be within the typical range for eggs and juvenile silver 16 hake. Because the thermal plume could exceed the typical range of temperatures that larvae 17 and adults inhabit, the NRC staff concludes that the heated thermal effluent may adversely 18 affect EFH for silver hake larvae and adults.

19 Loss of Forage Species. Silver hake consume a variety of prey, including copepod larvae, 20 copepodites, euphausiids, shrimp, amphipods, decapods, and other crustaceans and schooling 21 fish (e.g., young herring, mackerel, menhaden, alewives, sand lance, and silversides) and 22 squids (Bowman, 1984; Garrison and Link, 2000; Lock and Packer, 2004). NextEras 23 monitoring studies show relatively similar trends in abundance prior to and during operations at 24 nearfield and farfield sampling sites for zooplankton, benthic invertebrates, and most fish 25 species (NAI, 2010). Therefore, the NRC staff concludes that the potential loss of forage 26 species at Seabrook is not likely to adversely affect silver hake EFH during the remainder of the 27 facilitys operating license or during the proposed license renewal term.

28 Loss of Habitat-forming Species. Lock and Packer (2004) consider silver hake use and 29 preference of various bottom habitats a future research need. A recent literature search by 30 NRC staff did not indicate that silver hake prefer or heavily rely on shellfish beds or algae 31 covered areas.

32 Combined Impacts (Monitoring Data). NextEra monitored the abundance of silver hake eggs, 33 larvae juveniles, and adults prior to and during operations at sampling sites near the intake and 34 discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). Monitoring data indicate 35 that the abundance of silver hake eggs and larvae increased at both nearfield and farfield 36 sampling sites (Table D-1-8). Gill net surveys indicate that abundance of silver hake within the 37 water column decreased at both nearfield and farfield sites (Table D-1-10). Trawling surveys 38 indicate that silver hake abundance near the sea floor decreased at the nearfield site but 39 increased at the farfield sites (Table D-1-9). NAI (2010) did not report the statistical significance 40 of this relationship. Because adult and juvenile silver hake decreased at nearfield trawling sites 41 but increased at farfield trawling sites, these monitoring results suggest that Seabrook operation 42 may adversely affect bottom habitat for adult and juvenile silver hake.

43 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 44 may adversely affect EFH for silver hake eggs, larvae, juveniles, and adults for the following 45 reasons:

46

• Entrainment of silver hake eggs was relatively common at Seabrook.

D-1-62

Appendix D-1 1

• The thermal plume could exceed the typical range of temperatures that larvae and adults 2 inhabit.

3

• Adult and juvenile silver hake decreased at nearfield trawling sites but increased at 4 farfield trawling sites in NextEra monitoring studies.

5 D-1.3.3.16 Windowpane flounder (Scopthalmus aquosus) (Juveniles and Adults) 6 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile and adult 7 windowpane flounder EFH near Seabrook (NMFS, 2011b). NAI (2010) observed windowpane 8 flounder in greater than 10 percent of trawling samples, less than 1 percent of gill net samples, 9 and 1-10 percent of seine pull samples (Table D-1-2).

10 Species Description. Windowpane flounder inhabit estuaries, coastal waters, and oceans over 11 the continental shelf along the Atlantic coast from the Gulf of Saint Lawrence to Florida. This 12 species is most abundant from Georges Bank to Chesapeake Bay (Chang et al., 1999). North 13 of Cape Cod Bay, windowpane flounder inhabit nearshore waters, and distribution patterns 14 within estuaries is not well documented (Chang et al., 1999).

15 Windowpane flounder spawn in estuaries. Juveniles migrate from estuaries to coastal waters 16 during autumn, and they overwinter offshore in deeper waters. Adults remain offshore 17 throughout the year but inhabit nearshore waters in spring and autumn (Chang et al., 1999).

18 Langton et al. (1994) reported that adult windowpane occur primarily on sandy or muddy 19 substrates in the Gulf of Maine.

20 Juvenile and adult windowpane flounder have similar food sources, including small crustaceans 21 (especially shrimp) and fish larvae of hakes and tomcod. Predators include spiny dogfish, 22 thorny skate (Amblyraja radiata), goosefish, Atlantic cod, black sea bass (Centropristis striata),

23 weakfish (Cynoscion regalis), and summer flounder (Chang et al., 1999).

24 Status of the Fishery. The NEFMC manages windowpane flounder under the northeast 25 multispecies FMP. Windowpane flounder have never been widely directly targeted as a 26 commercial species but have been harvested in mixed-species fisheries since the 1900s. In the 27 1950s, landings were estimated to be as high as 2.04 million lb (924 MT) per year (Hendrickson, 28 2006). Landings ranged from 1.1-2.0 million lb (500-900 MT) per year from 1975-1981, 29 increased to a record high of 4.6 million lb (2,100 MT) in 1985, and they have since steadily 30 declined (Hendrickson, 2006). The windowpane stock structure has never been formally 31 quantified, and windowpane bycatch and discards from other fisheries are unknown and may 32 account for a significant portion of annual windowpane catch. Currently, NEFMC consider the 33 New England and Mid-Atlantic stock overfished (NMFS, 2010b).

34 Entrainment and Impingement. Although NMFS has not designated EFH for windowpane eggs 35 and larvae, entrainment and impingement can adversely affect recruitment of juveniles and 36 adults. Entrainment of windowpane eggs varied from 0.1 million in 1994 to 61.8 million in 2009 37 (NAI, 2010). Annual average entrainment of windowpane eggs was 31.7 million per year from 38 1990-2009 (Table D-1-4). Windowpane was the eighth most commonly entrained egg species, 39 comprising 3.5 percent of all entrained fish eggs at Seabrook.

40 Entrainment of windowpane larvae varied from 0.05 in 1991 to 6.5 million in 2002 (NAI, 2010).

41 Annual average entrainment of windowpane larvae was 2.3 million per year from 1990-2009 42 (Table D-1-5). Windowpane larvae comprised less than 1 percent of the total fish larvae 43 entrained at Seabrook from 1990-2009.

D-1-63

Appendix D-1 1 Impingement of windowpane varied from 161 in 2001 to 4,749 in 2003 (NAI, 2010). Annual 2 average impingement was 1,297 fish per year from 1994-2009 (Table D-1-6). Windowpane 3 was the fifth most commonly impinged fish species, comprising 6.2 percent of all impinged fish 4 at Seabrook from 1994-2009.

5 Because entrainment of windowpane eggs and impingement of juveniles and adults was 6 relatively common at Seabrook, the NRC staff concludes that entrainment and impingement 7 may have minimal adverse effects on EFH for windowpane during the remainder of the facilitys 8 operating license or during the proposed license renewal term. Effects would likely be minimal 9 since the amount of water (or habitat) captured in the Seabrook cooling system would be a very 10 small proportion of available habitat for all stages of windowpane.

11 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 12 available habitat to juvenile or adult windowpane. Juvenile and adult windowpane are primarily 13 benthic (Chang et al., 1999). A relatively small area near the discharge structure in deep water 14 experiences increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because 15 the buoyant thermal plume at the discharge points quickly rises toward the surface, the NRC 16 staff concludes that the heated effluent from Seabrook is not likely to adversely affect EFH for 17 juvenile or adult windowpane during the remainder of the facilitys operating license or during 18 the proposed license renewal term.

19 Loss of Forage Species. Juvenile and adult windowpane flounder prey on small crustaceans 20 (especially shrimp) and fish larvae of hakes and tomcod. NextEras monitoring studies show 21 relatively similar trends in abundance prior to and during operations at nearfield and farfield 22 sampling sites for zooplankton and invertebrates (NAI, 2010). Therefore, the NRC staff 23 concludes that the potential loss of forage species at Seabrook is not likely to adversely affect 24 EFH for windowpane flounder during the remainder of the facilitys operating license or during 25 the proposed license renewal term.

26 Loss of Habitat-forming Species. Juvenile and adult windowpane flounder do not appear to use 27 shellfish bed or algae for habitat. Therefore, the NRC staff concludes that the potential loss of 28 habitat-forming species at Seabrook is not likely to adversely affect windowpane EFH during the 29 remainder of the facilitys operating license or during the proposed license renewal term.

30 Combined Impacts (Monitoring Data). NextEra monitored the abundance of windowpane 31 juveniles and adults prior to and during operations at sampling sites near the intake and 32 discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). Trawling surveys indicate 33 that windowpane flounder decreased at the nearfield site but increased at the farfield sites 34 (Table D-1-9). However, the confidence intervals overlapped, suggesting that this relationship 35 would not be statistically significant. NAI (2010) did not report whether or not the relationship 36 was statistical significant. These monitoring results suggest that Seabrook operation is not 37 likely to adversely affect EFH of adult and juvenile windowpane.

38 Conclusion. Because entrainment of windowpane eggs and impingement of juveniles and 39 adults were relatively common at Seabrook, the NRC staff concludes that Seabrook operation 40 may have minimal adverse effects on EFH for windowpane during the remainder of the facilitys 41 operating license or during the proposed license renewal term. Impact would be minimal 42 because the thermal plume quickly rises to the surface, forage species and shellfish beds are 43 not likely to be adversely affected by Seabrook operations, and monitoring data shows similar 44 trends at nearfield and farfield sites.

D-1-64

Appendix D-1 1 D-1.3.3.17 Winter flounder (Pleuronectes americanus) (All Life Stages) 2 Designated EFH in the Vicinity of Seabrook. The NMFS has designated eggs, larvae, juvenile, 3 and adult winter flounder EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 4 winter flounder larvae in greater than 10 percent of ichthyoplankton tows, juveniles and adults in 5 greater than 10 percent of trawling samples, in 1-10 percent of gill net samples, and in more 6 than 10 percent of seine pull samples (Table D-1-2).

7 Species Description. There are three stocks of winter flounder in the Atlanticthe Gulf of 8 Maine, southern New England and the Middle Atlantic, and Georges Bank (Pereira et al., 1999).

9 In New England, winter flounder are common in inshore and nearshore waters (Pereira et al.,

10 1999). Adult winter flounder are a small-mouthed, right-eyed flounder that grow to 23 in. (58 11 cm) in total length and live up to 15 years (Pereira et al., 1999).

12 Adult winter flounder migrate inshore to bays and estuaries in the fall and early winter to spawn 13 and may remain inshore year-round in areas where temperatures are 59 degrees Fahrenheit 14 (15 degrees Celsius) or lower and enough food is available (Pereira et al., 1999). Studies vary 15 widely on the age of maturity of winter flounder. Generally, sexual maturity is dependent on size 16 rather than age, and southern individuals reach spawning size more rapidly than northern fish.

17 North of Cape Cod, OBrien et al. (1993) determined that the median age of maturity was 18 11.7 in. (29.7 cm) for females and 10.9 in. (27.6 cm) for males. In the Hampton-Seabrook area, 19 winter flounder spawn in coastal waters from February-April. Females spawn at depths of 7-60 20 ft (2-79 m) over sandy substrates in inshore coves and inlets at salinities of 31-32.5 parts per 21 thousand (ppt) (Buckley, 1989; Pereira et al., 1999). Eggs are demersal, stick to the substrate 22 (such as gravel or algal fronds), and are most often found at salinities between 10-30 ppt 23 (Buckley, 1989; Crawford and Cary, 1985). Larvae initially are planktonic but become 24 increasingly benthic as they develop (Pereira et al., 1999). Juveniles and adults are completely 25 benthic. Able et al. (1989 in Pereira et al., 1999) reported that juveniles use macroalgae.

26 Juveniles move seaward as they grow, remaining in estuaries for the first year (Buckley, 1989; 27 Grimes et al., 1989). Adult winter flounder tolerate salinities of 5-35 ppt and prefer waters 28 temperatures of 32-77 degrees Fahrenheit (0-25 degrees Celsius).

29 Winter flounder larvae feed on small invertebrates, invertebrate eggs, and phytoplankton 30 (Buckley, 1989; Pereira et al., 1999). Adults feed on benthic invertebrates such as polychaetes, 31 cnidarians, mollusks, and hydrozoans. Adults and juveniles are an important food source for 32 predatory fish such as the striped bass (Morone saxatilis), bluefish, goosefish, spiny dogfish, 33 and other flounders, and birds such as the great cormorant (Phalacrocorax carbo), great blue 34 heron (Ardea herodias), and osprey (Pandion haliaetus) (Buckley, 1989).

35 Status of the Fishery. Winter flounder are highly abundant in estuarine and coastal waters and, 36 therefore, are one of the most important species for commercial and recreational fisheries on 37 the Atlantic coast (Buckley, 1989). Winter flounder are, generally, commercially harvested using 38 otter trawl, but the species is also a popular recreational fish. Commercial landings of winter 39 flounder peaked in the 1980s throughout its range and declined through the early 2000s (Brown 40 and Gabriel, 1998; Pereira et al., 1999). Commercial landings reached a record low in 2005 at 41 2.98 million lb (1,350 MT) but have increased slightly since, with landings at 3.58 million lb 42 (1,622 MT) in 2007 (NEFSC, 2008).

43 The NEFMC manages the winter flounder in Federal waters under the northeast multispecies 44 FMP. As of 2009, the NEFMC reported that the Gulf of Maine winter flounder stock is 45 overfished (NOAA, 2010).

D-1-65

Appendix D-1 1 Entrainment and Impingement. Entrainment of winter flounder eggs varied from 0 in most years 2 to 1.05 million in 2008 (NAI, 2010). Annual average entrainment of winter flounder eggs was 3 96,500 per year from 1990-2009 (Table D-1-4). Winter flounder eggs comprised less than 4 1 percent of the total fish eggs entrained at Seabrook from 1990-2009.

5 Entrainment of winter flounder larvae varied from 0 in 1994 to 34.8 million in 2004 (NAI, 2010).

6 Annual average entrainment of winter flounder larvae was 9.2 million per year from 1990-2009 7 (Table D-1-5). Winter flounder larvae was the eighth most commonly entrained species, 8 comprising 3.4 percent of the total fish larvae entrained at Seabrook from 1990-2009.

9 Impingement of winter flounder varied from 102 in 2000 to 10,491 in 2003 (NAI, 2010). Annual 10 average impingement was 2,082 fish per year from 1994-2009 (Table D-1-6). Winter flounder 11 was the third most commonly impinged fish species, comprising 10 percent of all impinged fish 12 at Seabrook from 1994-2009.

13 Because entrainment of winter flounder larvae and impingement of juveniles and adults were 14 relatively common at Seabrook, the NRC staff concludes that entrainment and impingement 15 may have minimal adverse effects on EFH for winter flounder during the remainder of the 16 facilitys operating license or during the proposed license renewal term. Effects would likely be 17 minimal since the amount of water (or habitat) captured in the Seabrook cooling system would 18 be a very small proportion of available habitat for all stages of winter flounder.

19 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 20 available habitat to eggs, larvae, juvenile, or adult winter flounder. Winter flounder are primarily 21 benthic (Pereira et al., 1999.) A relatively small area near the discharge structure in deep water 22 experiences increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991). Because 23 the buoyant thermal plume at the discharge points quickly rises toward the surface, the NRC 24 staff concludes that the heated effluent from Seabrook is not likely to adversely affect EFH for 25 winter flounder during the remainder of the facilitys operating license or during the proposed 26 license renewal term.

27 Loss of Forage Species. Winter flounder feed on phytoplankton, small invertebrates, 28 invertebrate eggs, and benthic invertebrates such as polychaetes, cnidarians, mollusks, and 29 hydrozoans. NextEras monitoring studies show relatively similar trends prior to and during 30 operations at nearfield and farfield sampling sites for the abundance, density, and species 31 composition of zooplankton and invertebrates (NAI, 2010). Therefore, the NRC staff concludes 32 that the potential loss of forage species at Seabrook is not likely to adversely affect winter 33 flounder EFH during the remainder of the facilitys operating license or during the proposed 34 license renewal term.

35 Loss of Habitat-forming Species. Window flounder eggs may be deposited on macroalgae 36 (Crawford and Carey, 1985), but spawning occurs in estuaries and NAI (2010) did not observe 37 winter flounder eggs in monitoring studies near Seabrook, likely due to its offshore location.

38 Able et al. (1989 in Pereira et al., 1999) reported that juveniles use macroalgae habitat, along 39 with other types of habitats. Seabrook monitoring data indicate that the density of several 40 species of kelp has decreased at nearfield sampling stations since operations began (NAI, 41 2010). Because juvenile winter flounder may utilize macroalgae habitat, along with other types 42 of aquatic vegetation, the NRC staff concludes that the potential loss of habitat-forming species 43 at Seabrook may have minimal adverse effects on juvenile winter flounder EFH during the 44 remainder of the facilitys operating license or during the proposed license renewal term.

D-1-66

Appendix D-1 1 Combined Impacts (Monitoring Data). NextEra monitored the abundance of winter flounder 2 larvae, juveniles, and adults prior to and during operations at sampling sites near the intake and 3 discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). Monitoring data indicate 4 that the abundance of larvae decreased at both nearfield and farfield sampling sites 5 (Table D-1-8). Trawling data for juveniles and adults indicated different trends at the nearfield 6 and farfield sites (NAI, 2010). At the nearfield site, the abundance of winter flounder 7 significantly decreased over time from a mean CPUE of 5.5 prior to operations to 2.3 during 8 operations (Table D-1-9). However, at both farfield sampling sites, the mean CPUE increased 9 from 2.8 and 1.4 prior to operations, respectively, to 4.0 and 3.6 during operations. This 10 increase was statistically significant at one of the farfield sites. Based on monitoring data, NRC 11 concludes that Seabrook operation has adversely affected EFH for winter flounder because the 12 abundance of winter flounder has decreased to a greater and observable extent near 13 Seabrooks intake and discharge structures compared to 3-4 mi (5-8 km) away.

14 Conclusion. Based on the above analysis, the NRC staff concludes that Seabrook operations 15 may adversely affect EFH for winter flounder larvae, juveniles, and adults for the following 16 reasons:

17

• Entrainment of winter flounder larvae and impingement of juveniles and adults were 18 relatively common at Seabrook.

19

• Juveniles may use algal habitats that have declined near Seabrook since operations 20 began.

21

• Ault and juvenile winter flounder abundance decreased at nearfield trawling sites but 22 increased at farfield trawling sites in NextEra monitoring studies.

23 D-1.3.3.18 Yellowtail flounder (Pleuronectes ferruginea) (Juveniles and Adults) 24 Designated EFH in the Vicinity of Seabrook. The NMFS has designated juvenile and adult 25 yellowtail flounder EFH in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) observed 26 yellowtail flounder in greater than 10 percent of trawling samples, in less than 1 percent of gill 27 net samples, and in less than 1 percent of seine pull samples (Table D-1-2).

28 Species Description. Yellowtail flounder occur along the U.S. and Canadian coasts from the 29 Gulf of St. Lawrence, Labrador, and Newfoundland to the Chesapeake Bay (Bigelow and 30 Schroeder, 1953; Johnson et al., 1999). Juveniles and adults are asymmetrical benthic flatfish 31 (Johnson et al., 1999). Preferred habitat includes areas covered in sand or sand-mud 32 sediments where demersal prey inhabits (Bowering and Brodie, 1991; Johnson et al., 1999).

33 Juvenile yellowtail flounder consume primarily polychaetes while adult yellowtail flounder 34 consume primarily crustaceans, such as amphipods and sand dollars (Echinarachius parma) 35 (Johnson et al., 1999). Predators include spiny dogfish, winter skate, Atlantic cod, Atlantic 36 halibut, fourspot flounder, goosefish, little skate, smooth skate, silver hake, bluefish, and sea 37 raven (Johnson et al., 1999).

38 Status of the Fishery. Yellowtail first became commercial desirable in the 1930s and is currently 39 a highly targeted fish (Johnson et al., 1999). In 2009, NEFMC considered yellowtail overfished 40 (NMFS, 2010b).

41 Entrainment and Impingement. Although NMFS has not designated EFH for yellowtail flounder 42 eggs and larvae, entrainment and impingement can adversely affect recruitment of juveniles D-1-67

Appendix D-1 1 and adults. Entrainment of yellowtail flounder eggs varied from 0 in multiple years to 569.2 2 million in 1991 (NextEra, 2010a). Annual average entrainment of yellowtail flounder eggs was 3 42.8 million per year from 1990-2009 (Table D-1-4). Yellowtail flounder eggs was the sixth 4 most commonly entrained fish egg species, comprising 4.8 percent of the total fish eggs 5 entrained at Seabrook from 1990-2009.

6 Entrainment of yellowtail flounder larvae varied from 0 in 1994 to 2.7 million in 2007 (NAI, 2010).

7 Annual average entrainment of winter flounder larvae was 0.4 million per year from 1990-2009 8 (Table D-1-5). Yellowtail flounder larvae comprised less than 1 percent of the total fish larvae 9 entrained at Seabrook from 1990-2009.

10 Impingement of yellowtail flounder varied from 0 in several years to 1,149 in 1995 (NAI, 2010).

11 Annual average impingement was 83 fish per year from 1994-2009 (Table D-1-6). Yellowtail 12 flounder comprised less than 1 percent of all impinged fish at Seabrook from 1994-2009.

13 Because entrainment of yellowtail flounder eggs was relatively common at Seabrook, the NRC 14 staff concludes that entrainment may have minimal adverse effects on EFH for yellowtail 15 flounder during the remainder of the facilitys operating license or during the proposed license 16 renewal term. Effects would likely be minimal since the amount of weather (or habitat) 17 entrained in the Seabrook cooling system would be a very small proportion of available habitat 18 for yellowtail flounder eggs.

19 Thermal Effects. The NRC staff does not expect Seabrooks thermal discharges to reduce 20 available habitat to juvenile or adult yellowtail flounder. Juvenile and adult yellowtail flounder 21 are benthic flatfish (Johnson et al., 1999). A relatively small area near the discharge structure in 22 deep water experiences increased temperatures (NAI, 2001; Padmanabhan and Hecker, 1991).

23 Because the buoyant thermal plume at the discharge points quickly rises toward the surface, the 24 NRC staff concludes that the heated effluent from Seabrook is not likely to adversely affect EFH 25 for yellowtail flounder during the remainder of the facilitys operating license or during the 26 proposed license renewal term.

27 Loss of Forage Species. Juvenile yellowtail flounder consume primarily polychaetes while adult 28 yellowtail flounder consume primarily crustaceans, such as amphipods and sand dollars 29 (Johnson et al., 1999). NextEras monitoring studies show relatively similar trends in 30 abundance prior to and during operations at nearfield and farfield sampling sites for 31 invertebrates (NAI, 2010). Therefore, the NRC staff concludes that the potential loss of forage 32 species at Seabrook is not likely to adversely affect yellowtail flounder EFH during the 33 remainder of the facilitys operating license or during the proposed license renewal term.

34 Loss of Habitat-forming Species. Juvenile and adult yellowtail flounder do not commonly use 35 kelp or shellfish beds. Therefore, the NRC staff concludes that the potential loss of 36 habitat-forming species at Seabrook is not likely to adversely affect yellowtail flounder EFH 37 during the remainder of the facilitys operating license or during the proposed license renewal 38 term.

39 Combined Impacts (Monitoring Data). NextEra monitored the abundance of yellowtail flounder 40 juveniles and adults prior to and during operations at sampling sites near the intake and 41 discharge structures and at sites 3-4 mi (5-8 km) away (NAI, 2010). Monitoring data indicate 42 that the abundance of juveniles and adults decreased at both nearfield and farfield sampling 43 sites (Table D-1-9). Because NAI (2010) found similar trends at both the nearfield and farfield 44 sites, these monitoring results suggest that Seabrook operations have not adversely affected 45 EFH for juvenile or adult yellowtail.

D-1-68

Appendix D-1 1 Conclusion. Because entrainment of yellowtail flounder eggs was relatively common at 2 Seabrook, Seabrook operation may have minimal adverse effects on EFH for juvenile and adult 3 yellowtail flounder during the remainder of the facilitys operating license or during the proposed 4 license renewal term. Impacts would be minimal for the following reasons:

5

• Impingement and entrainment are relatively low for yellowtail flounder.

6

• The thermal plume quickly rises to the surface.

7

• Forage species and shellfish beds are not likely to be adversely affected by Seabrook 8 operations.

9

• Monitoring data show similar trends at nearfield and farfield sites.

10 D-1.3.3.19 Essential Fish Habitat Species Not Likely to Regularly Occur Near 11 Seabrook 12 The NMFS has designated EFH for eggs, larvae, juvenile and adult Atlantic halibut; adult bluefin 13 tuna; larvae, juvenile, and adult redfish; and juvenile and adult longfin inshore squid and 14 northern shortfin squid in the vicinity of Seabrook (NMFS, 2011b). NAI (2010) never, rarely, or 15 occasionally observed Atlantic halibut, bluefin tuna, redfish, northern shortfin squid, and longfin 16 inshore squid during monitoring, entrainment, and impingement studies from the 1970s-2009.

17 For example, NAI (2010) rarely identified Atlantic halibut in trawling surveys and did not report 18 Atlantic halibut in any other monitoring surveys or any impingement or entrainment studies. NAI 19 (2010) occasionally identified redfish in trawling surveys and did not report redfish in other 20 monitoring surveys or any impingement or entrainment studies. Bluefin tuna were not reported 21 in any monitoring, entrainment, or impingement studies. Seabrook did not explicitly include 22 longfin inshore squid and northern shortfin squid in its entrainment and impingement studies.

23 However, field technicians did not recall any time that squid have been impinged at Seabrook 24 (NRC, 2011). Longfin inshore squid lay eggs on the seafloor and larvae are often found near 25 the surface, whereas the intake structure is located in deeper water (Jacobson, 1995). Northern 26 shortfin squid eggs and larvae are pelagic, but primarily occur within the Gulf Stream 27 (Hendrickson and Holmes, 2004).

28 Bluefin tuna, longfin inshore squid, and northern shortfin squid are pelagic and, therefore, could 29 encounter the thermal plume when passing by Seabrook. Surface waters near the thermal 30 plume typically range as high as 65.8 degrees Fahrenheit (18.8 degrees Celsius) (NAI, 2001).

31 NEFSC trawl data indicate that northern shortfin squid inhabit waters up to as 66 degrees 32 Fahrenheit (19 degrees Celsius), and longfin inshore squid inhabit waters up to as 79 degrees 33 Fahrenheit (26 degrees Celsius) (NAI, 2001). With a temperature rise of 3-5 degrees 34 Fahrenheit (1.7-2.8 degrees Celsius), the thermal plume near the surface could exceed the 35 typical temperature range for northern shortfin squid but would be within the typical temperature 36 range for longfin inshore squid. Bluefin tuna have never been captured in any of NextEras 37 monitoring study; therefore, the relatively small size of the thermal plume is not likely to 38 adversely affect large amounts of EFH for bluefin tuna if any happen to pass by Seabrook. The 39 thermal plume is not likely to adversely affect EFH for Atlantic halibut or redfish because both of 40 these species are pelagic and the thermal plume rises quickly to the surface.

41 Bluefin tuna, longfin inshore squid, and northern shortfin squid are pelagic and, therefore, not 42 likely to regularly inhabit benthic habitats such as kelp forest or shellfish beds. Redfish and 43 Atlantic halibut may use kelp near Seabrook, along with other habitats that provide structure.

44 Seabrook monitoring data indicate that the density of several species of kelp has decreased at D-1-69

Appendix D-1 1 nearfield sampling sites since operations began (NAI, 2010). Because the density of kelp is 2 lower since operations began at Seabrook, but Atlantic halibut and redfish rarely or occasionally 3 use habitat near Seabrook, the NRC staff concludes that Seabrook operations may have 4 minimal adverse effects on Atlantic halibut and redfish.

5 Forage species for Atlantic halibut, bluefin tuna, redfish, longfin inshore squid, and northern 6 shortfin squid are not likely to be adversely affected near Seabrook. Typical prey includes 7 copepods, euphausiids, crabs, polychaetes, shrimp, and fish. NextEras monitoring studies 8 show relatively similar trends in abundance prior to and during operations at nearfield and 9 farfield sampling sites for zooplankton, benthic invertebrates, and most fish species (NAI, 2010).

10 Therefore, the NRC staff concludes that the potential loss of forage species at Seabrook is not 11 likely to adversely affect EFH for Atlantic halibut, bluefin tuna, redfish, longfin inshore squid, or 12 northern shortfin squid during the remainder of the facilitys operating license or during the 13 proposed license renewal term.

14 Based on the above analysis, the NRC staff concludes that Seabrook operations may have 15 minimal adverse effects on EFH for northern shortfin squid because the thermal plume near the 16 surface could exceed the typical temperature range for northern shortfin squid. Seabrook 17 operations may have minimal adverse effects on EFH for redfish and Atlantic halibut because 18 both species may use kelp beds near Seabrook. Seabrook operations are not likely to affect 19 EFH for longfin inshore squid or bluefin tuna.

20 D-1.4 Cumulative Effects to Essential Fish Habitat 21 This section addresses the direct and indirect effects of license renewal on EFH when added to 22 the aggregate effects of other past, present, and reasonably foreseeable future actions. The 23 geographic area considered in the cumulative aquatic resources analysis includes the vicinity of 24 Seabrook, the offshore intake and discharge structures, the Hampton-Seabrook Estuary, and 25 the rivers that drain into the Hampton-Seabrook Estuary.

26 Section 2.2.6.2 of the SEIS summarizes the condition of the Gulf of Maine and the 27 Hampton-Seabrook Estuary and the history and factors that led to its current condition. The 28 direct and indirect impacts from fishing are some of the most influential human activities on the 29 Gulf of Maine ecosystem (Sosebee et al., 2006). Fishing has caused wide-scale changes in fish 30 populations and food web dynamics within the Gulf of Maine (Sosebee et al., 2006; Steneck et 31 al., 1994). In the Hampton-Seabrook Estuary, wetland habitat and water flow has been affected 32 by human uses such as those listed below (Eberhardt and Burdick, 2009):

33

• harvesting salt marsh hay (Spartina patens) as feed for livestock in the 1700 and 1800s 34

• digging ditches in an attempt to control mosquito populations in the early 1900s 35

• building roads, jetties, commercial buildings, and residential areas in the 1900s and 36 2000s 37 The increased urbanization in the past 100 years has caused increased runoff and levels of 38 pollutants within the Hampton-Seabrook Estuary (NHDES, 2004). In the rivers connected to 39 Hampton-Seabrook Estuary, dams block fish migrations and have resulted in the precipitous 40 decline of anadromous fish that move to freshwater to spawn and to marine waters to grow and 41 feed (Eberhardt and Burdick, 2009).

D-1-70

Appendix D-1 1 Many natural and anthropogenic activities can influence the current and future EFH in the area 2 surrounding Seabrook. Potential biological stressors include continued entrainment, 3 impingement, and potential heat shock from Seabrook (if the license renewal is granted), and 4 fishing mortality, climate change, energy development, and urbanization, as described below.

5 Fishing. Fishing has been a major influence on the population levels of commercially-sought 6 fish species in the Gulf of Maine (Sosebee et al., 2006). The Hampton-Seabrook Estuary and 7 the Gulf of Maine support significant commercial and recreational fisheries for many of the fish 8 and invertebrate species also affected by Seabrook operations. EPA (2002b) determined that 9 69 percent of all entrained and impinged fish species at Seabrook are commercially or 10 recreationally fished. From 1990-2000, Atlantic cod comprised 33 percent of the catch in New 11 Hampshire and 25 percent of the revenue. Other commercially important and EFH species in 12 New Hampshire include spiny dogfish shark, pollock, Atlantic herring, bluefin tuna, American 13 plaice, white hake, yellowtail flounder, and shrimp. Recreationally fished species include 14 American lobster, striped bass, summer flounder, Atlantic cod, scup, and bluefish (EPA, 2002b).

15 Federal, regional, and State agencies manage many of these fisheries, although the biomass of 16 many fish stocks have not rebounded to pre-1960s levels (Sosebee, 2006). Indirect impacts 17 from fishing include habitat alteration as well as indirect effects that propagate throughout the 18 food web.

19 For these reasons, the NRC staff concludes that fishing pressure has the potential to continue 20 to influence the aquatic ecosystem, especially food webs, and may continue to contribute to 21 cumulative impacts on EFH.

22 Climate Change. The potential cumulative effects of climate change on the Gulf of Maine and 23 Hampton-Seabrook Estuary could result in a variety of changes that would affect EFH. The 24 environmental factors of significance identified by the U.S. Global Change Research Program 25 (USGCRP) (2009) include temperature increases and sea level rise. Warming sea 26 temperatures may influence the abundance and distribution of species, as well as earlier 27 spawning times. For example, USGCRP (2009) projects that lobster populations will continue to 28 shift northward in response to warming sea temperatures. Atlantic cod, which were subject to 29 intense fishing pressure and other biological stressors, are likely to be adversely affected by the 30 warmer temperatures because this species inhabits cold waters (USGCRP, 2009). USGCRP 31 (2009) projects that the Georges Bank Atlantic cod fishery will likely diminish by 2100. NMFS 32 (2009) analyzed fish abundance data from 1968-2007 and determined that the range of several 33 species of fish is moving northward or deeper, likely in response to warming sea temperatures.

34 Warmer temperatures can also lead to earlier spawning because spawning time is often 35 correlated with a distinct temperature ranges. Seabrook monitoring studies showed a shift in 36 blue mussel spawning times (NAI, 2010). From 1996-2002, and select years from 2002-2009, 37 the greatest blue mussel larval density occurred in mid-April, whereas the greatest blue mussel 38 larval density occurred in late April in the 1970s, 1980s, and early 1990s.

39 Sea level rise could result in dramatic effects to nearshore communities and EFH, including the 40 reduction or redistribution of kelp, eelgrass, and wetland communities. Aquatic vegetation is 41 particularly susceptible to sea level rise because it is immobile and cannot move to shallower 42 areas. In addition, most species grow within a relatively small range of water depth in order to 43 receive sufficient light to photosynthesize.

44 The ocean absorbs nearly one-third of the carbon dioxide (CO2) released into the atmosphere 45 (NMFS, 2011d). As atmospheric CO2 increases, there is a concurrent increase in CO2 levels in 46 the ocean (NMFS, 2011d). Ocean acidification is the process by which CO2 is absorbed by the D-1-71

Appendix D-1 1 ocean, forming carbonic and carbolic acids that increase the acidity of ocean water. More acidic 2 water can lead to a decrease in calcification (or a softening) of shells for bivalves (e.g., Atlantic 3 sea scallops and Atlantic surf clams), decreases in growth, and increases in mortality in marine 4 species (Nye, 2010).

5 The extent and magnitude of climate change impacts to the aquatic resources of the Gulf of 6 Maine and the Hampton-Seabrook Estuary are an important component of the cumulative 7 assessment analyses and could be substantial.

8 Energy Development. As part of a technical workshop held by NOAA, Johnson et al. (2008) 9 categorized the largest non-fishing impacts to coastal fishery habitats. Johnson et al. (2008) 10 determined that the largest known and potential future impacts to marine habitats are primarily 11 from the development of energy infrastructure, including petroleum exploration, production, and 12 transportation; liquefied natural gas development; offshore wind development; and cables and 13 pipelines in aquatic ecosystems.

14 Petroleum explorations and offshore wind development can result in habitat conversion and a 15 loss of benthic habitat as developers dig, blast, or fill biologically productive areas. Petroleum 16 and liquefied natural gas development can adversely affect water quality if there are oil spills or 17 discharges of other contaminants during exploration or transportation related activities.

18 Underwater cables and pipelines may block fish and other aquatic organisms from migrating to 19 various habitats (Johnson et al., 2008). Thus, energy development may contribute to future 20 cumulative impacts in a variety of ways.

21 Urbanization. The area surrounding the Hampton-Seabrook Estuary experienced increased 22 residential and commercial development in the 1900s, as the seaside town became a popular 23 tourist destination (Eberhardt and Burdick, 2009). At the beginning of the 21st century, 24 moderate commercial and residential development surrounded the Hampton-Seabrook Estuary 25 (NHNHB, 2009). The town of Hamptons Master Plan calls for continued growth in the area to 26 sustain its attractiveness for tourists (Hampton, 2001).

27 Increased urbanization has led, and will likely continue to lead, to additional stressors on the 28 Hampton-Seabrook Estuary. Run-off from developed and agricultural areas has increased the 29 concentration of nutrients, bacteria, and other pollutants to the estuary. Sections of the 30 Hampton-Seabrook Estuary are listed on New Hampshires 303(d) list as being impaired due to 31 high concentrations of bacteria (NHDES, 2004). NHDES (2004) also lists the estuary as 32 impaired for fish and shellfish consumption due to polychlorinated biphenyl, dioxin, and mercury 33 concentrations in fish tissue and lobster tomalley. Other activities that may affect marine 34 aquatic resources in Hampton-Seabrook Estuary include periodic maintenance dredging, 35 continued urbanization and development, and construction of new overwater or near-water 36 structures (e.g., docks), and shoreline stabilization measures (e.g., sheet pile walls, rip-rap, or 37 other hard structures).

38 Future threats to salt marshes in the Hampton-Seabrook Estuary include developmental 39 activities that further hydrological alterations from filling wetlands or other physical changes that 40 alter the flow of tidal waters (Johnson et al., 2008; NHNHB, 2009). Increased nutrients and 41 pollutants in storm runoff are also current threats to the health of this ecosystem 42 (NHNHB, 2009). The NRC staff concludes that the direct and indirect impacts from future 43 urbanization are likely to contribute to cumulative impacts in the Hampton-Seabrook Estuary.

44 Conclusion. The direct impacts to fish populations, from fishing pressure and alterations of 45 aquatic habitat within the Hampton-Seabrook watershed from past activities, have had a D-1-72

Appendix D-1 1 significant effect on aquatic resources in the geographic area near Seabrook. These aquatic 2 ecosystems have been adversely affected, as evidenced by the low population numbers for 3 several commercially-sought fisheries, the change in food web dynamics, habitat alterations, 4 and the blockage of fish passage within the Hampton-Seabrook watershed. The cumulative 5 stress from the activities described above, spread across the geographic area of interest, 6 depends on many factors that NRC staff cannot quantify but are likely to adversely affect EFH 7 when all stresses on the aquatic communities are assessed cumulatively. Therefore, the NRC 8 staff concludes that the cumulative impacts from the proposed license renewal and other past, 9 present, and reasonably foreseeable projects may adversely affect the EFH of most species, 10 especially Atlantic cod due to climate change.

11 D-1.5 Essential Fish Habitat Conservation Measures 12 NextEra prepared a proposal for information collection (PIC) as a first step to comply with EPAs 13 2004 proposed Phase II rule of Section 316(b) of CWA (NAI and ARCADIS, 2008). In this 14 document, NextEra identified three types of mitigation that are now in place and reduce 15 entrainment and impingement (NAI and ARCADIS, 2008). First, the location of the intake 16 structures is offshore in an area of reduced biological activity as compared to an inshore 17 location. Second, the design of the intake structures includes velocity caps, which fish tend to 18 avoid due to the changes in horizontal flow of water created by the velocity cap. Third, less 19 water is pumped from the Gulf of Maine to Seabrook due to the offshore location, which 20 provides cooler water than an inshore location (NAI and ARCADIS, 2008).

21 NextEra identified other intake technologies that might mitigate adverse intake effects, such as 22 physical barriers, collection systems, diversion systems, and behavioral deterrent systems.

23 Velocity caps that are installed on Seabrooks intake structures are considered behavioral 24 deterrents. In addition, NextEra installed a seal deterrent system by adding vertical bars on 25 intake structures to prevent seals from being trapped and drowning (NextEra, 2010a). NextEra 26 did not consider any additional physical barriers, collection, or diversion systems to be practical 27 for Seabrook due to the additional costs associated with designing and constructing these 28 technologies in an open water environment as compared to an inshore environment.

29 D-1.6 Conclusion 30 Table D-1-13 summarizes NRC conclusions on the effect of Seabrook operation on habitat for 31 the 23 EFH species that may occur within the vicinity of Seabrook.

32 Table D-1-13. Summary of NRC conclusions Regarding the Effect on Habitat by Species 33 and Life Stages Species Eggs Larvae Juveniles Adults Rational for adverse impact American plaice NL(a) NL Atlantic butterfish NL NL NL NL (b)

Atlantic cod NL MIN MIN MIN Some of the primary and preferred forage fish, such as Atlantic herring and American sand lance, are regularly entrained and impinged at Seabrook; the thermal plume near the surface could slightly exceed the typical range of temperatures that Atlantic cod inhabit; juvenile cod likely use kelp beds near Seabrook.

Atlantic halibut NL NL MIN MIN Atlantic halibut may use algal habitats that have D-1-73

Appendix D-1 Species Eggs Larvae Juveniles Adults Rational for adverse impact declined near Seabrook since operations began.

Atlantic herring MIN MIN The thermal plume near the surface could slightly exceed the typical range of temperatures that Atlantic herring juveniles and adults inhabit.

Atlantic mackerel MIN NL NL MIN Atlantic mackerel is the second most entrained egg species, comprising 21.3 percent of the total fish eggs entrained at Seabrook. The thermal plume near the surface could exceed the typical temperature range that adult Atlantic mackerel inhabit.

Atlantic sea scallop NL NL MIN NL Newly settled Atlantic sea scallops may use algal habitats that have declined near Seabrook since operations began.

Atlantic surf clam NL NL Bluefin tuna NL Haddock NL Longfin inshore NL NL squid Monkfish/Goosefish MIN MIN MIN NL The thermal plume near the surface could slightly exceed the typical range of temperatures that goosefish eggs and larvae inhabit; juveniles may use algal habitats that have declined near Seabrook since operations began.

Northern shortfin MIN MIN The thermal plume near the surface could exceed squid the typical temperature range for northern shortfin squid.

Ocean pout NL NL MIN NL Juveniles may use algal habitats that have declined near Seabrook since operations began.

Pollock MIN Pollock is the sixth most impinged fish species, comprising 6.1 percent of the total fish impinged at Seabrook. Juveniles may use algal habitats that have declined near Seabrook since operations began.

Redfish NL MIN MIN Redfish may use algal habitats that have declined near Seabrook since operations began.

Red hake MIN MIN MIN MIN The hake (which includes red, white, and spotted hake) comprised 6.2 percent of all entrained fish eggs and 6.5 percent of all impinged fish at Seabrook.

Scup NL NL Summer flounder MIN Summer flounder may use algal habitats that have declined near Seabrook since operations began.

Whiting/Silver hake ADV(c) ADV ADV ADV Silver hake was the third most commonly entrained egg species, comprising 9 percent of all entrained fish eggs at Seabrook. The thermal plume could exceed the typical range of temperatures that larvae and adults inhabit, and adult and juveniles decreased at nearfield trawling sites but increased at farfield trawling sites in NextEra monitoring studies.

Windowpane MIN MIN Windowpane comprised 3.5 percent of all entrained eggs and 6.2 percent of all impinged fish at D-1-74

Appendix D-1 Species Eggs Larvae Juveniles Adults Rational for adverse impact flounder Seabrook Winter flounder NL ADV ADV ADV Winter flounder was the third most commonly impinged fish species, comprising 10 percent of all impinged fish. Winter flounder larvae was the eighth most commonly entrained species, comprising 3.4 percent of the total fish larvae entrained. Winter flounder may use algal habitats that have declined near Seabrook since operations began. Adult and juvenile winter flounder abundance decreased at nearfield trawling sites but increased at farfield trawling sites in NextEra monitoring studies.

Yellowtail flounder MIN MIN Yellowtail flounder eggs was the sixth most commonly entrained fish egg species, comprising 4.8 percent of the total fish eggs entrained at Seabrook.

(a)

NL= Seabrook operation is not likely to affect EFH.

(b)

MIN= Seabrook operation may have minimal adverse effects on EFH.

(c)

ADV= Seabrook operation may adversely affect EFH.

1 D-1.7 References 2 Able, K.W., K.A. Wilson and K.L. Heck, Jr., 1989, Fishes of the Vegetated Habitats in New 3 Jersey Estuaries: Composition, Distribution and Abundance, Based on Quantitative Sampling, 4 Center for Coastal and Environmental Studies, Rutgers University, New Brunswick, NJ, 5 Publication No. 1041, 39 p. in Pereira et al., 1999 6 Almeida, F.P., D.L. Hartley and J. Burnett, 1995, Lengthweight Relationships and Sexual 7 Maturity of Goosefish off the Northeast Coast of the United States, North American Journal of 8 Fisheries Management, 15: 14-25.

9 ARCADIS et al., 2008, "Cooling Water Intake Structure Information Document," Prepared for 10 Florida Power and Light (FPL) Energy Seabrook, LLC (FPLE), Appendix A, July 2008.

11 Armstrong, M. P., J. A. Musick and J. A. Colvocoresses, 1996, Food and Ontogenetic Shifts in 12 Feeding of the Goosefish, Lophius americanus, Journal of Northwest Atlantic Fishery Science, 13 18: 99-103.

14 Auster, P.J., R.J. Malatesta and S.C. LaRosa, 1995, Patterns of Microhabitat Utilization by 15 Mobile Megafauna on the Southern New England (USA) Continental Shelf and Slope, Mar.

16 Ecol. Prog. Ser., 127: 77-85.

17 Baird, S.F., 1873, Natural History of Some of the More Important Food-Fishes of the South 18 Shore of New England, Report on the Condition of the Sea Fisheries of the South Coast of 19 New England in 1871 and 1872, Rep. Commissioner U.S. Comm. Fish. Fisheries, Pt. I, p. 228-20 235, in Steimle et al., 1999d.

21 Berrien, P., 1982, Atlantic mackerel, Scomber scombrus, MESA New York Bight Atlas 22 Monograph 15, Sea Grant Institute, Albany, NY, p.99-102, in Studholme et al., 1999.

23 Bigelow, H.B. and W.C. Schroeder, 1953, Fishes of the Gulf of Maine, USFWS Bulletin 53, 24 577 p.

D-1-75

Appendix D-1 1 Bigelow, H.B. and W.C. Schroeder, 2002, Butterfish, Porontus triacanthus (Peck) 1800: in 2 Fishes of the Gulf of Maine, Fishery Bulletin of the Fish and Wildlife Service, No. 74, Vol. 53.

3 Revision 1.1, originally published in 1953, Available URL:

4 http://www.gma.org/fogm/Poronotus_triacanthus.htm (accessed December 14, 2010).

5 Bowering, W.R. and W.B. Brodie, 1991, Distribution of Commercial Flatfishes in the 6 Newfoundland-Labrador Region of the Canadian Northwest Atlantic and Changes in Certain 7 Biological Parameters since Exploitation, Neth. J. Sea Res., 27: 407-422.

8 Bowman, R.E., 1975, Food habits of Atlantic cod, haddock, and silver hake in the northwest 9 Atlantic, 1969-1972, U.S. Natl. Mar. Fish. Serv., Northeast Fish. Cent. Lab. Ref., 75-1; 53 p. in 10 Lough, 2004.

11 Bowman, R.E., 1984, Food of Silver Hake, Merluccius bilinearis, Fish. Bull. (U.S.), 82: 21-35.

12 Bowman, R.E. and W.L. Michaels, 1984, Food of Seventeen Species of Northwest Atlantic 13 Fish, NOAA Tech. Mem. NMFS-F/NEC-28, 183 p.

14 Bowman, R.E., et al., 1987, Food and Distribution of Juveniles of Seventeen Northwest Atlantic 15 Fish Species, 1973-1976, NOAA Tech. Mem. NMFS-F/NEC-45, 57 p.

16 Brodziak, J., 2001, Silver Hake, Available URL:

17 http://www.nefsc.nmfs.gov/sos/spsyn/pg/silverhake/silverhake.pdf (accessed October 15, 2001),

18 in Lock and Packer, 2004.

19 Brodziak, J., 2005, Essential Fish Habitat Source Document: Haddock, Melanogrammus 20 aeglefinus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 2nd Edition, 21 196; 64 p.

22 Brown, R. and W. Gabriel, 1998, Winter Flounder, Status of the Fishery Resources off the 23 Northeastern United States for 1998, NOAA Tech. Mem. NMFS-NE-115, p. 81-84.

24 Buckley, J., 1989, Species Profiles: Life Histories and Environmental Requirements of Coastal 25 Fishes and Invertebrates (North Atlantic)Winter Flounder, U.S. Fish and Wildlife Service 26 Biological Report, 82(11.87), U.S. Army Corps of Engineers, TR EL 82 4. Available URL:

27 http://www.nwrc.usgs.gov/wdb/pub/species_profiles/82_11-087.pdf (accessed September 7, 28 2010).

29 Cargnelli, L.M., et al., 1999, Essential Fish Habitat Source Document: Pollock, Pollachius 30 Virens, Life History and Habitat Characteristics, NOAA Tech Memo, 131; 30 p.

31 Cargnelli, L.M., et al., 1999a, Essential Fish Habitat Source Document: Atlantic Surfclam, 32 Spisula solidissima, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 33 142; 13 p.

34 Chang, S., 1990, Seasonal Distribution Patterns of Commercial Landings of 45 Species off the 35 Northeast United States during 1977-88, NOAA Tech. Mem. NMFS-F/NEC-78, 130 p.

36 Chang, S., 1999, Essential Fish Habitat Source Document: Windowpane, Scophthalmus 37 aquosus, Life History and Habitat Characteristics, NOAA Technical Memorandum 38 NMFS-NE-137, Available URL:

D-1-76

Appendix D-1 1 http://www.nefsc.noaa.gov/nefsc/publications/tm/tm137/tm137.pdf (accessed December 7, 2 2010).

3 Cross, J.N., et al., 1999, Essential Fish Habitat Source Document: Butterfish, Peprilus 4 triacanthus, Life History and Habitat Characteristics, NOAA Technical Memorandum 5 NMFS-NE-145, Available URL:

6 http://www.nefsc.noaa.gov/nefsc/publications/tm/tm145/tm145.pdf (accessed December 7, 7 2010).

8 Crawford, R.E. and C.G. Carey, 1985, Retention of Winter Flounder Larvae within a Rhode 9 Island Salt Pond, Estuaries, 8: 217-227.

10 Dow, R.L. and F.T. Baird, Jr., 1960, Scallop Resources of the United States Passamaquoddy 11 Area, U.S. Fish. Wildl. Serv. Spec. Sci. Rep., Fish. No. 367., 9 p. in Hart and Chute, 2004.

12 Edwards, R.L. and R.E. Bowman, 1979, Food Consumed by Continental Shelf Fishes, 13 Predator-prey Systems in Fish Communities and their Role in Fisheries Management, Sport 14 Fishing Institute, Washington, D.C., pp. 387-406, in Lough, 2004.

15 Fahay, M.P., 1983, Guide to the Early Stages of Marine Fishes Occurring in the Western North 16 Atlantic Ocean, Cape Hatteras to the Southern Scotian Shelf, J. Northwest Atl. Sci., 4: 1-423.

17 Fisheries and Oceans Canada (DFO), 1989, Communications Directorate, Ottawa, Ontario, 18 Available URL: http://www.mi.mun.ca/mi%2Dnet/fishdeve/plaice.htm (accessed February 25, 19 2004), in Johnson, 2004.

20 FPLE, 2008, "Seabrook Station Updated Final Safety Analysis Report," Revision 12, August 1, 21 2008.

22 Gallego, A. and M.R. Heath, 1994, The Development of Schooling Behaviour in Atlantic 23 Herring, Clupea harengus, J. Fish. Biol., 45: 569-588.

24 Garrison, L.P. and J.S. Link, 2000, Diets of Five Hake Species in the Northeast United States 25 Continental Shelf Ecosystem, Mar. Ecol. Prog. Ser., 204: 243-255.

26 Hardy, J.D., Jr., 1978, Development of Fishes of the Mid-Atlantic Bight: An Atlas of Egg, Larval 27 and Juvenile Stages, Vol. 2 Anguillidae through Syngnathidae, U.S. Fish Wildl. Serv. Biol. Serv.

28 Prog., FWS/OBS-78/12, 458 p. in Cargnelli, et al., 1999.

29 Hart D.R. and A.S. Chute, 2004, Essential Fish Habitat Source Document: Sea Scallop, 30 Placopecten magellanicus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS 31 NE, 2nd Edition, 189; 21 p.

32 Hartley, D.L., 1995, The Population Biology of the Goosefish, Lophius americanus, in the Gulf 33 of Maine, M.S. Thesis, University of Massachusetts, Amherst, MA, 142 p., in Steimle et al.,

34 1999a.

35 Hendrickson, L., 2006. Status of Fishery Resources off the Northeastern U.S.: Windowpane 36 Flounder (Scophthalmus aquosus), December 2006. Available URL:

37 http://www.nefsc.noaa.gov/sos/spsyn/fldrs/window/ (accessed December 10, 2010).

D-1-77

Appendix D-1 1 Hendrickson LC, Holmes EM, 2004, "Essential Fish Habitat Source Document: Northern shortfin 2 squid, Illex illecebrosus, Life History and Habitat Characteristics (2nd edition), NOAA Tech 3 Memo NMFS NE 191; 36 p.

4 Jacobson LD, 2005, "Essential Fish Habitat Source Document: Longfin inshore squid, Loligo 5 pealeii, Life History and Habitat Characteristics (2nd edition), NOAA Tech Memo NMFS NE 193; 6 42 p.

7 Jeffrey, J.A. and C.T. Taggart, 2000, Growth Variation and Water Mass Associations of Larval 8 Silver Hake (Merluccius bilinearis) on the Scotian Shelf, Can. J. Fish. Aquat. Sci.,

9 57: 17281738.

10 Johnson, D.L., 2005, Essential Fish Habitat Source Document: American plaice, 11 Hippoglossoides platessoides, Life History And Habitat Characteristics, NOAA Tech Memo 12 NMFS NE, 2nd Edition, 187; 72 p.

13 Johnson D.L., et al., 1999, Essential Fish Habitat Source Document: Yellowtail flounder, 14 Limanda ferruginea, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 15 140; 29 p.

16 Johnson, M.R., et al., 2008, Impacts to Marine Fisheries Habitat from Nonfishing Activities in 17 the Northeastern United States, NOAA Technical Memorandum NMFS-NE-209, NMFS, 18 Northeast Regional Office, Gloucester, MA.

19 Kane, J., 1984, The Feeding Habits of Co-occurring Cod and Haddock Larvae from Georges 20 Bank, Mar. Ecol. Prog. Ser., 16: 9-20.

21 Keats, D.W., 1991, American Plaice, Hippoglossoides platessoides (Fabricius), Predation on 22 Green Sea Urchins, Strongylocentrotus droebachiensis (O.F. Muller) in eastern Newfoundland, 23 J. Fish Biol., 38: 67-72.

24 Klein-MacPhee, G., 2002, Haddock/ Melanogrammus aeglefinus Linnaeus 1758, Bigelow and 25 Schroeders fishes of the Gulf of Maine, Smithsonian Institution Press, Washington D.C., 3rd 26 Edition, pp. 235-242.

27 Koeller, P.A., L..Coates-Markle, and J.D. Neilson, 1989, Feeding Ecology of Juvenile (Age-0) 28 Silver Hake (Merluccius bilinearis) on the Scotian Shelf, Can. J. Fish. Aquat. Sci., 46:

29 17621768.

30 Langton, R.W., J.B. Pearce, and J.A. Gibson, eds., 1994, Selected Living Resources, Habitat 31 Conditions, and Human Perturbations of the Gulf of Maine: Environmental and Ecological 32 Considerations for Fishery Management, NOAA Tech. Mem., NMFS-NE-106, 70 p.

33 Langton, R.W., W.E. Robinson, and D. Schick, 1987, Fecundity and Reproductive Effort of Sea 34 Scallops Placopecten magellanicus from the Gulf of Maine, Mar. Ecol. Prog. Ser., 37: 19-25.

35 Langton, R.W. and L. Watling, 1990, The Fish-Benthos Connection: A Definition of Prey 36 Groups in the Gulf of Maine, Trophic Relationships in the Marine Environment: Proceedings 37 24th European Marine Biology Symposium, Aberdeen University Press, Aberdeen, Scotland, 38 pp. 424-438, in Steimle et al., 1999b.

D-1-78

Appendix D-1 1 Larsen, P.F. and R.M. Lee, 1978, Observations on the Abundance, Distribution and Growth of 2 Post-Larval Sea Scallops, Placopecten magellanicus, on Georges Bank, Nautilus, 92:

3 112116.

4 Lascara, J., 1981, "Fish Predator-prey Interactions in Areas of Eelgrass (Zostera marina), M.S.

5 thesis, Coll. William and Mary, Williamsburg, VA. 81 p., in Packer et al. 1999.

6 Link, J.S. and L.P. Garrison, 2002, Trophic Ecology of Atlantic cod Gadus morhua on the 7 Northeast US Continental Shelf, Mar. Ecol. Prog. Ser., 227: 109-123.

8 Lock M.C. and P.B. Packer, 2004, Essential Fish Habitat Source Document: Silver Hake, 9 Merluccius bilinearis, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 10 2nd Edition, 186; 68 p.

11 Lough, R.G., 2004, Essential Fish Habitat Source Documents: Atlantic Cod, Gadus morhua, 12 Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 2nd Edition, 190; 94 p.

13 Lux, F.E. and F.E. Nichy, 1981, Movements of Tagged Summer Flounder, Paralichthys 14 dentatus, off Southern New England, NOAA Tech. Rep. NMFS SSRF-752, 16 p., in Packer et 15 al., 1999.

16 MacDonald, J.S., 1983., Laboratory Observations of Feeding Behavior of the Ocean Pout 17 (Macrozoarces americanus) and Winter Flounder (Pseudopleuronectes americanus) with 18 Reference to Niche Overlap of Natural Populations, Can. J. Zool., 61: 539-546.

19 MacDonald, J.S. and R.H. Green, 1986, Food Resource Utilization by Five Species of Benthic 20 Feeding Fish in Passamaquoddy Bay, New Brunswick, Can. J. Fish. Aquat. Sci., 43:

21 15341546.

22 Martin, F.D. and G.E. Drewry, 1978, Development of Fishes of the Mid-Atlantic Bight: An Atlas 23 of Egg, Larval and Juvenile Stages, Vol. 6: Stromateidae through Ogcocephalidae, U.S. Fish 24 Wildl. Serv. Biol. Serv. Prog., FWS/OBS 78/12, 416 p. in Steimle, et al., 1999a.

25 Maurer, R. and R.E. Bowman, 1975, Food Habits of Marine Fishes of the Northwest Atlantic 26 Data Report, U.S. Natl. Mar. Fish. Serv. Northeast Fish. Cent. Woods Hole Lab. Ref. Doc.,

27 75-3, 90 p. in Stevenson and Scott, 2005.

28 Mayo, R., 1995, Atlantic Cod, Status of the Fishery Resources off the Northeastern United 29 States for 1994, NOAA Tech. Mem. NMFS-NE, 108: 44-47.

30 Merrill, A.S. and Ropes, J.W., 1969, The General Distribution of the Surf clam and Ocean 31 quahog, Proc. Nat. Shellfish, Assoc. 59: 40-45, in Cargnelli et al., 1999a.

32 Munroe, T.A., 2002, Atlantic herring/Clupea harengus Linnaeus 1758, Bigelow and 33 Schroeders Fishes of the Gulf of Maine, Smithsonian Institution Press, Washington D.C., 3rd 34 Edition, pp. 141-156.

35 National Marine Fisheries Service (NMFS), July 30, 2002, Small Takes of Marine Mammals 36 Incidental to Specified Activities; Taking of Marine Mammals Incidental to Power Plant 37 Operations, Federal Register, Vol. 67, No., 146, pp. 49292-49293.

D-1-79

Appendix D-1 1 NMFS, 2009, Ecosystem Assessment Report for the Northeast U.S. Continental Shelf Large 2 Marine Ecosystem, Northeast Fisheries Science Center Reference Document 09 11, Northeast 3 Fisheries Science Center, Ecosystem Assessment Program.

4 NMFS, 2010a, Letter from P. Kurkul, Regional Administrator, to B. Pham, Branch Chief, NRC.

5

Subject:

Re: Renewal Application for Seabrook Station, Seabrook, NH, Agencywide Documents 6 Access and Management System (ADAMS) Accession No. ML102240108.

7 NMFS, 2010b, 2009 Status of U.S. Fisheries: Message from Eric Schwaab NOAAs Assistant 8 Administrator for Fisheries, Status Determination by Region, Changes in Stock Status for 2009, 9 Office of Sustainable Fisheries.

10 NMFS, 2011a, Guide to Essential Fish Habitat Designations in the Northeastern Unites States, 11 Available URL: http://www.nero.noaa.gov/hcd/webintro.html (accessed March 8, 2011).

12 NMFS, 2011b, Summary of Essential Fish Habitat (EFH) Designation, Available URL:

13 http://www.nero.noaa.gov/hcd/STATES4/Gulf_of_Marine_3_western_part/42507040.html 14 (accessed March 8, 2011).

15 NMFS, 2011c, Guide to Essential Fish Habitat Descriptions, Available URL:

16 http://www.nero.noaa.gov/hcd/list.htm (accessed March 22, 2011).

17 NMFS, 2011d, Ocean Acidification: The Other Carbon Dioxide Problem, Available URL:

18 http://www.pmel.noaa.gov/co2/story/Ocean+Acidification (accessed February 22, 2011).

19 National Oceanic and Atmospheric Administration (NOAA), 2009, NOAA Fisheries Weekly 20 Quota Management Report for Butterfish, Week Ending December 26, 2009. Available URL:

21 http://www.nero.noaa.gov/ro/fso/reports/reports_frame.htm (accessed December 9, 2010).

22 NOAA, 2010, Butterfish Coastwide Weekly Landings Report. Available URL:

23 http://www.nero.noaa.gov/ro/fso/reports/reports_frame.htm (accessed December 9, 2010).

24 NextEra, 2010 Applicant's Environmental ReportOperating License Renewal Stage, 25 Appendix E, Docket No. 050-443, ADAMS Accession Nos. ML101590092 and ML101590089.

26 NextEra Energy Seabrook, LLC (NextEra), 2010a, letter to U.S. NRC Document Control Desk, 27 Seabrook Station Response to Request for NextEra Energy Seabrook License Renewal 28 Environmental Report, SBK-L-10185, Docket No. 50-443, ADAMS Accession 29 No. ML103350639.

30 Normandeau Associates Inc. (NAI), 1998, Seabrook Station 1996 Environmental Monitoring in 31 the Hampton-Seabrook Area: A Characterization of Environmental Conditions, Prepared for 32 Northeast Utilities Service Company.

33 NAI, 2001, Seabrook Station Essential Fish Habitat Assessment, R-18900.009, Prepared for 34 North Atlantic Energy Service Corporation.

35 NAI, 2010, Seabrook Station 2009 Environmental Monitoring in the Hampton-Seabrook Area: A 36 Characterization of Environmental Conditions, Prepared for NextEra.

37 NAI and ARCADIS (NAI and ARCADIS), 2008, Seabrook Nuclear Power Station EPA 316(b) 38 Phase II Rule Project, Revised Proposal for Information Collection, Prepared for FPLE, 39 Section 7.0, June 2008.

D-1-80

Appendix D-1 1 New Hampshire Department of Environmental Services (NHDES), 2004, Total Maximum Daily 2 Load (TMDL) Study for Bacteria in Hampton/Seabrook Harbor, State of New Hampshire, 3 Department of Environmental Services, Water Division, Watershed Management Bureau, May 4 2004.

5 New Hampshire Natural Heritage Bureau (NHNHB), 2009, Memo from M. Coppola to S.

6 Barnum, Normandeau Associates.

Subject:

Database Search for Rare Species and Exemplary 7 Natural Communities Along Seabrook Station Transmission Corridors, NHB File ID: NHB09-8 0508, March 18, 2009, ADAMS Accession No. ML101590089.

9 Nye, J., 2010, Climate Change and Its Effect on Ecosystems, Habitats, and Biota: State of the 10 Gulf of Maine Report, Gulf of Maine Council on the Marine Environment and NOAA, June 2010.

11 OBrien, L., J. Burnett, and R.K. Mayo, 1993, Maturation of Nineteen Species of Finfish off the 12 Northeast Coast of the United States, 1985-1990, NOAA Tech. Rep. NMFS, 113; 66 p.

13 Ojeda, F.P. and J.B.

Dearborn,

1989, Community Structure of Macroinvertebrates Inhabiting 14 the Rocky Subtidal Zone in the Gulf of Maine: Seasonal and Bathymetric Distribution, Marine 15 Ecology Progress Series, 57:147-161.

16 Ojeda, F.P. and J.H.

Dearborn,

1991, Feeding Ecology of Benthic Mobile Predators:

17 Experimental Analyses of their Influence in Rocky Subtidal Communities of the Gulf of Maine, 18 J. Exp. Mar. Biol. Ecol., 149: 13-44.

19 Overholtz, W., 2006, Status of Fishery Resources off the Northeastern U.S.: Butterfish 20 (Peprilus triacanthus), Available URL: http://www.nefsc.noaa.gov/sos/spsyn/op/butter/#tab241 21 (accessed December 9, 2010).

22 Overholtz, W.J. and E.D. Anderson, 1976, Relationship Between Mackerel Catches, Water 23 Temperature, and Vessel Velocity during USA Spring Bottom Trawl Surveys in SA 5-6, Int.

24 Comm. Northwest Atl. Fish. (ICNAF) Res., Doc. 76/XIII/170; 7 p., in Studholme et al., 1999.

25 Packer D.B., et al., 1999, Essential Fish Habitat Source Document: Summer Flounder, 26 Paralichthys dentatus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 27 151; 88 p.

28 Padmanabhan M. and G.E. Hecker, 1991, Comparative Evaluation of Hydraulic Model and Field 29 Thermal Plume Data, Seabrook Nuclear Power Station, Alden Research Laboratory, Inc.

30 Pereira, J.J., et al., 1999, Essential Fish Habitat Source Document: Winter Flounder, 31 Pseudopleuronectes americanus, Life History and Habitat Characteristics, NOAA Technical 32 Memorandum NMFS-NE-138, Available URL:

33 http://www.nefsc.noaa.gov/nefsc/publications/tm/tm138/tm138.pdf (accessed December 7, 34 2010).

35 Peterson, W.T. and S.J. Ausubel, 1984, Diets and Selective Feeding by Larvae of Atlantic 36 mackerel Scomber scombrus on Zooplankton, Mar. Ecol. Prog. Ser., 17: 65-75.

37 Scott, W.B. and M.G. Scott, 1988, "Atlantic Fishes of Canada," Can. Bull. Fish. Aquat. Sci. 219, 38 731p., in Steimle et al., 1999a.

D-1-81

Appendix D-1 1 Sedberry, G.R., 1983, Food Habits and Trophic Relationships of a Community of Fishes on the 2 Outer Continental Shelf, NOAA Tech. Rep. NMFS SSRF, 773; 56 p. in Steimle et al., 1999b.

3 Sette, O.E., 1943, Biology of Atlantic Mackerel (Scomber scombrus) of North America. Part I:

4 Early Life History Including Growth, Drift, and Mortality of the Egg and Larval Populations, U.S.

5 Fish Wildl. Serv. Fish. Bull., 50: 149-237, in Studhome et al., 1999.

6 Sette, O.E., 1950, Biology of Atlantic Mackerel (Scomber scombrus) of North America. Part II.

7 Migrations and Habits, U.S. Fish Wildl. Serv. Fish. Bull., 51: 251-358 in Studholme et al., 1999.

8 Sherman, K. and H.C. Perkins, 1971, Seasonal Variation in the Food of Juvenile Herring in 9 Coastal Waters of Maine, Trans. Am. Fish. Soc., 100: 121-124.

10 Shumway, S.E., R. Selvin, and D.F. Schick, 1987, Food Resources Related to Habitat in the 11 Scallop Placopecten magellanicus (Gmelin, 1791): A Qualitative Study, J. Shellfish Res., 6:

12 8995.

13 Sosebee, K., 1998, Red hake, Status of the Fishery Resources off the Northeastern United 14 States for 1998, NOAA Tech. Mem. NMFS-NE, 115: 64-66.

15 Sosebee, K. M. Traver and R. Mayo. 2006, Aggregate Resource and Landings Trends, 16 Available URL: http://www.nefsc.noaa.gov/sos/agtt/archives/AggregateResources_2006.pdf 17 (accessed January 25, 2011).

18 Steimle F.W., et al., 1999a, Essential Fish Habitat Source Document: Goosefish, Lophius 19 americanus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 127; 31 p.

20 Steimle, F.W., et al., 1999b, Essential Fish Habitat Source Document: Ocean Pout, 21 Macrozoarces Americanus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS 22 NE, 129; 26 p.

23 Steimle, F.W., et al., 1999c, Essential Fish Habitat Source Document: Red Hake, Urophycis 24 Chuss, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 133; 34 p.

25 Steimle F.W., et al., 1999d, Essential Fish Habitat Source Document: Scup, Stenotomus 26 Chrysops, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 149; 39 p.

27 Steimle F.W., W.W. Morse, and D.L. Johnson, 1999a, Essential Fish Habitat Source 28 Document: Goosefish, Lophius Americanus, Life History and Habitat Characteristics, NOAA 29 Tech Memo NMFS NE, 127; 31 p.

30 Steiner, W.W., J.J. Luczkovich, and B.L. Olla, 1982, Activity, Shelter Usage, Growth and 31 Recruitment of Juvenile Red Hake, Urophycis chuss, Mar. Ecol. Prog. Ser., 7: 125-135.

32 Stevenson, D.K and M.L. Scott, 2005, Essential Fish Habitat Source Document: Atlantic 33 Herring, Clupea harengus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS 34 NE, 2nd Edition, 192; 84 p.

35 Studholme, A.L., et al., 1999, Essential Fish Habitat Source Document: Atlantic Mackerel, 36 Scomber Scombrus, Life History and Habitat Characteristics, NOAA Tech Memo NMFS NE, 37 141; 35 p.

D-1-82

Appendix D-1 1 Sullivan, L.F., 1981, American plaice, Hippoglossoides platessoides in the Gulf of Maine: I. The 2 Fishery, II. Age and Growth, III. Spawning and Larval Distribution, M.S. Thesis, University of 3 Rhode Island, Kingston, RI, 132 p. in Johnson 2004.

4 Thompson, C., 2010, The Gulf of Maine in Context, State of the Gulf of Maine Report, Gulf of 5 Maine Council on the Marine Environment, Fisheries, and Oceans, Canada, June 2010.

6 The Town of Hampton (Hampton), 2001, Hampton Beach Area Master Plan, The Town of 7 Hampton, NH, NH Department of Resources and Economic Development, Division of Parks and 8 Recreation, November 7, 2001, Available URL:

9 http://www.hampton.lib.nh.us/hampton/town/masterplan/index.htm (accessed September 30, 10 2010).

11 United States Code (U.S.C.), Definitions, Part 1802, Title 10, Conservation, Chapter 38, 12 Fishery Conversation and Management.

13 U.S. Code of Federal Regulations (CFR), Magnuson-Stevens Act Provisions, Part 600, Title 14 50, Wildlife and Fisheries.

15 U.S. Environmental Protection Agency (EPA), 2002, Authorization to Discharge Under the 16 National Pollutant Discharge Elimination System (NPDES) Permit No. NH0020338, transferred 17 to FPL Energy Seabrook, LLC., December 24, 2002.

18 EPA, 2002b, "Case Study Analysis for the Proposed Section 316(b) Phase II Existing Facilities 19 Rule, EPA 821 R 02 002, Office of Water, Washington, DC.

20 EPA, 2010, Enforcement & Compliance History Online (ECHO), Detailed Facility Report, 2010, 21 Available URL:

22 http://www.epa-echo.gov/cgi-bin/get1cReport.cgi?tool=echo&IDNumber=110001123061 23 (accessed October 1, 2010).

24 U.S. Global Change Research Program (USGCRP), 2009, Global Climate Change Impacts in 25 the United States, Cambridge University Press, Cambridge, MA, Available URL:

26 http://downloads.globalchange.gov/usimpacts/pdfs/climate impacts report.pdf (accessed 27 January 20, 2011).

28 U.S. Nuclear Regulatory Commission (NRC), 1996, Generic Environmental Impact Statement 29 for License Renewal of Nuclear Plants, NUREG-1437, Washington, D.C., Volumes 1 and 2, 30 ADAMS Accession Nos. ML040690705 and ML040690738.

31 NRC, 2010, Letter from B. Pham, Branch Chief, to P. Kurkul, Regional Administrator, NMFS, 32

Subject:

Request for List of Protected Species and Essential Fish Habitat Within the Area Under 33 Evaluation for the Seabrook Station License Renewal Application Review, ADAMS Accession 34 No. ML101760221.

35 NRC, 2011, Summary of telephone conference calls held on February 3, 2011, between the 36 NRC and NextEra to Clarify information pertaining to the review of the Seabrook Station license 37 renewal application (TAC NO. ME3959), ADAMS Accession No. ML110560362.

38 Wigley, S., 1998, Ocean Pout, Status of the Fishery Resources off the Northeastern United 39 States for 1998, NOAA Tech. Mem. NMFS-NE-115, pp. 94-95.

D-1-83

Appendix D-1 1 Witman, J.D. and K.P. Sebens, 1992, Regional Variation in Fish Predation Intensity: a 2 Historical Perspective in the Gulf of Maine, Oecologia, 90: 305-315.

3 Witman, J.D. and P.K. Dayton, 2001, Chapter 13: Rocky Subtidal Communities, Marine 4 Community Ecology, Sinauer Associates, Inc., Sunderland, MA, 2001.

D-1-84

APPENDIX E CHRONOLOGY OF ENVIRONMENTAL REVIEW

Appendix E 1 E CHRONOLOGY OF ENVIRONMENTAL REVIEW 2 CORRESPONDENCE 3 This appendix contains a chronological listing of correspondence between the U.S. Nuclear 4 Regulatory Commission (NRC) and external parties as part of its environmental review for 5 Seabrook Station (Seabrook). All documents, with the exception of those containing proprietary 6 information, are available electronically from the NRCs Public Electronic Reading Room, found 7 on the Internet at the following Web address: http://www.nrc.gov/reading-rm.html. From this 8 site, the public can gain access to the NRCs Agencywide Documents Access and Management 9 System (ADAMS), which provides text and image files of NRCs public documents. The 10 ADAMS accession number for each document is included below.

11 E.1 Environmental Review Correspondence March 3, 2010 Letter from Ms. Brona Simon, State Historic Preservation Officer, Commonwealth of Massachusetts, Massachusetts Historical Commission, indicating that the Massachusetts Historical Commission had completed its review of the proposed Seabrook license renewal and had no concerns (ADAMS Accession No. ML100880129)

May 25, 2010 Letter from NextEra Energy Seabrook, LLC (NextEra) forwarding the application for renewal of the operating license for Seabrook, requesting an extension of the operating license for an additional 20 years (ADAMS Accession No. ML101590099)

May 25, 2010 Applicants Environmental Report (ER), cover through page B-90 (ADAMS Accession No. ML101590092)

May 25, 2010 Applicants ER page C-1 through page F.A-5 (ADAMS Accession No. ML101590089)

May 28, 2010 Letter from NextEra to the State of New Hampshire Department of Environmental Services, Seabrook, Federal Coastal Zone Consistency Certification for License Renewal (ADAMS Accession No. ML101550353)

May 31, 2010 Report submitted by Mr. Brian Valimont, New England Archaeology Co, LLC, Enclosure, Cultural Resources Management Plan Seabrook Nuclear Power Plant Seabrook and Hampton Falls, New Hampshire (ADAMS Accession No. ML103280393)

June 1, 2010 Letter to Ms. Ann Robinson, Town of Seabrook, NH, Maintenance of Reference Materials at the Seabrook Library in Regards to the Review of the Seabrook Station License Renewal Application (ADAMS Accession No. ML101180134)

June 1, 2010 Letter to Ms. Patricia DeTullio, Town of Amesbury, MA, Maintenance of Reference Materials at the Amesbury Public Library in Regards to the Review of the Seabrook Station License Renewal Application (ADAMS Accession No. ML101260102)

June 10, 2010 Letter from NRC to NextEra, Receipt and Availability of the License Renewal Application for the Seabrook Station Nuclear Power Plant (ADAMS Accession No. ML101320273)

June 10, 2010 Federal Register Notice, Notice of Receipt and Availability for Seabrook Station License Renewal Application (ADAMS Accession No. ML101330049)

July 13, 2010 Letter from NRC to NextEra, Notice of Intent to Prepare an Environmental Impact Statement and Conduct the Scoping Process for License Renewal for Seabrook Station (ADAMS Accession No. ML101680410)

July 13, 2010 Federal Register Notice, Notice of Intent to Prepare an Environmental Impact Statement and Conduct the Scoping Process for License Renewal for Seabrook Station (ADAMS Accession No. ML101680427)

July 13, 2010 Letter from NRC to NextEra, Determination of Acceptability and Sufficiency for Docketing, Proposed Review Schedule, and Opportunity for a Hearing Regarding the Application from NextEra Energy Seabrook, LLC, for Renewal of the Operating License for Seabrook Station, Unit 1 (ADAMS Accession No. ML101690417)

E-1

Appendix E July 13, 2010 Federal Register Notice, Notice of Acceptance for Docketing of the Application and Notice of Opportunity for Hearing Regarding Renewal of Facility Operating License No. NPF-086 for an Additional 20-year Period (ADAMS Accession No. ML101690449)

July 16, 2010 Letter from NRC to Mr. Reid Nelson, Director, Office of Federal Agency Programs, Advisory Council On Historic Preservation, regarding the Seabrook License Renewal (ADAMS Accession No. ML101760128)

July 16, 2010 Letter from NRC to Ms. Patricia Kurkul, Regional Administrator, Northeast Region, National Marine Fisheries Service (NMFS), Request for List of Protected Species and Essential Fish Habitat Within the Area Under Evaluation for the Seabrook Station License Renewal Application Review (ADAMS Accession No. ML101760221)

July 16, 2010 Letter from NRC to Ms. Elizabeth Muzzey, State Historic Preservation Officer, State of New Hampshire, Division of Historical Resources, Seabrook Station License Renewal Application Review (ADAMS Accession No. ML101790273)

July 16, 2010 Letter from NRC to Mr. Marvin Moriarty, U.S. Fish and Wildlife Service (USFWS), Request for List of Protected Species Within the Area Under Evaluation for the Seabrook Station License Renewal Application Review (ADAMS Accession No. ML101790278)

July 16, 2010 Summary of telephone conference call held between NRC and NextEra concerning the review of acceptability of docketing of the Seabrook license renewal application (LRA) (ADAMS Accession No. ML101800207)

July 16, 2010 Letter from NRC to Mr. Thomas Burack, Commissioner, State of New Hampshire, Department of Environmental Services, Seabrook Station License Renewal Application Review (ADAMS Accession No. ML101900093)

July 20, 2010 Federal Register Notice, Forthcoming Meeting to Discuss the License Renewal Process and Environmental Scoping for Seabrook Station License Renewal Application Review (ADAMS Accession No. ML101900013)

July 20, 2010 NRC press release announcing an opportunity for a hearing on the application to renew the operating license for Seabrook (ADAMS Accession No. ML102010170)

July 27, 2010 Letter from Edna Feighner, State of New Hampshire, Division of Historical Resources, regarding the Seabrook license renewal (ADAMS Accession No. ML102160299)

August 4, 2010 NRC Press Release announcing the public meetings to discuss the process for the review of the Seabrook LRA at to seek input on the environmental review (ADAMS Accession No. ML102160633)

August 5, 2010 Letter from Ms. Patricia Kurkul, Regional Administrator, Northeast Region, NMFS, Scoping Letter Response From NMFS Regarding the Seabrook License Renewal Application (ADAMS Accession No. ML102240108)

August 12, 2010 Email from NRC to Ms. Emily Holt, Commonwealth of Massachusetts, Division of Fisheries and Wildlife (DFW), Email to [Massachusetts] DFW re State-Listed Rare Species Near Seabrook Station (ADAMS Accession No. ML102240484)

August 18, 2010 Email from Ms. Emily Holt, Commonwealth of Massachusetts, Division of Fisheries and Wildlife, E-mail from MA DFW re State-Listed Species Near Seabrook Station (ADAMS Accession No. ML102360545)

August 19, 2010 Letter from Ms. Maggie Hassan, Senator, State of New Hampshire, regarding the Seabrook license renewal (ADAMS Accession No. ML102420037)

August 19, 2010 Transcript of the Seabrook license renewal public meetingafternoon session, August 19, 2010 (ADAMS Accession No. ML102520183)

August 19, 2010 Transcript of the Seabrook license renewal public meetingevening session, August 19, 2010 (ADAMS Accession No. ML102520207)

August 23, 2010 Letter from Mr. William Harris regarding the Seabrook license renewal (ADAMS Accession No. ML102500271)

August 25, 2010 Letter from Mr. William Harris regarding the Seabrook license renewal (ADAMS Accession No. ML102420043)

E-2

Appendix E August 26, 2010 Letter from NRC to Ms. Melissa Coppola, State of New Hampshire, New Hampshire Natural Heritage Bureau, Seabrook Station License Renewal Application Review (ADAMS Accession No. ML102290417)

September 1, 2010 Letter from Mr. Geordie Vining regarding the Seabrook license renewal (ADAMS Accession No. ML102450525)

September 1, 2010 Letter from Mr. Thomas Chapman, USFWS, Scoping Letter from USFWS Regarding the Seabrook [license renewal application] LRA [supplemental environmental impact statement]

SEIS (ADAMS Accession No. ML102630180)

September 7, 2010 Letter from NRC to NextEra, Environmental Site Audit Regarding Seabrook Station License Renewal Application (ADAMS Accession No. ML102390177)

September 7, 2010 Memoranda from Ms. Melissa Coppola, State of New Hampshire, New Hampshire Natural Heritage Bureau, NH NHB State-Listed Species and Communities [in support of] Seabrook LRA SEIS (ADAMS Accession No. ML102520087)

September 13, 2010 Memoranda from Ms. Melissa Coppola, State of New Hampshire, New Hampshire Natural Heritage Bureau, NH NHB State-Listed Species in T-Lines[in support of] Seabrook LRA SEIS (ADAMS Accession No. ML102600341)

September 20, 2010 Summary of Seabrook License Renewal Overview and Environmental Scoping Meetings held on August 19, 2010 (ADAMS Accession No. ML102520222)

September 20, 2010 Letter from Ms. Joyce Kemp regarding the Seabrook license renewal (ADAMS Accession No. ML102640371)

September 20, 2010 Letter from Mr. Joseph Fahey, Director, Office of Community and Economic Development, Town of Amesbury, Massachusetts, regarding the Seabrook license renewal (ADAMS Accession No. ML102650486)

September 20, 2010 Letter from Mr. Andrew Port, Director of Planning and Development, City of Newburyport, MA, regarding the Seabrook license renewal (ADAMS Accession No. ML102660331)

September 21, 2010 Letter from Mr. Doug Bogen, Executive Director, Seacoast Anti-Pollution League, regarding the Seabrook license renewal (ADAMS Accession No. ML102670048)

October 15, 2010 Letter from NRC to the Abenaki Nation of New Hampshire, Cowasuck Band of Pennacook-Abenaki People, Abenaki Nation of Missisquoi, and Wampanoag Tribe of Gay Head-Aquinnah, Request for Scoping Comments Concerning the Seabrook Station License Renewal Application Review (ADAMS Accession No. ML102730657)

October 29, 2010 Letter from NRC to NextEra, Request for Additional Information for the Review of the Seabrook Station License Renewal Application Environmental Review (TAC NO. ME3959) (ADAMS Accession No. ML102861217)

November 4, 2010 Letter from Mr. Christian Williams, State of New Hampshire, Department of Environmental Services, to NextEra, regarding the Seabrook Coastal Zone Management Act Certification (ADAMS Accession No. ML103080880)

November 8, 2010 Letter from NRC to NextEra, Environmental Project Manager Change for the License Renewal of Seabrook Station, Unit 1 (TAC ME3959) (ADAMS Accession No. ML103070056)

November 10, 2010 Summary of the site audit related to the review of the Seabrook LRA, October 5-7, 2010 (ADAMS Accession No. ML102950271)

November 16, 2010 Letter from NRC to NextEra, Request for Additional Information for the Review of the Seabrook Station License Renewal Application-[Severe Accident Mitigation Alternative] SAMA Review (TAC ME3959) (ADAMS Accession No. ML103090215)

November 23, 2010 Letter from NextEra, Seabrook StationResponse to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report (ADAMS Accession No. ML103350639)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 5, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML103360298)

E-3

Appendix E November 23, 2010 Letter from NextEra, Attachment 2, Vol. 7, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML103360300)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 4, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML103360306)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 2, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit, Continued (ADAMS Accession No. ML103360311)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 6, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML103360326)

November 23, 2010 Letter from NextEra Attachment 2, Vol. 3, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML103370092)

November 23, 2010 Letter from NextEra, Attachment 3 to SBK-L-10185, Seabrook Station Response to Request for Additional Information, NextEra Energy Seabrook License Renewal Environmental Report (ADAMS Accession No. ML103370167)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 2, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML103370169)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 1, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML110100311)

November 23, 2010 Letter from NextEra, Attachment 2, Vol. 1, to SBK-L-10185, Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report, References Requested for Docketing at the Seabrook Station Environmental Site Audit (ADAMS Accession No. ML110100312)

November 23, 2010 Letter from NextEra, Attachment 1 to SBK-L-10185, "Seabrook Station Response to Request for Additional Information NextEra Energy Seabrook License Renewal Environmental Report (ADAMS Accession No. ML110100315)

December 3, 2010 Summary of the telephone conference between NRC and NextEra concerning the draft request for information pertaining to the Seabrook SAMAs review, November 8 and 10, 2010 (ADAMS Accession No. ML103260521)

December 21, 2010 Summary of the telephone conference call between NRC and NextEra concerning the draft request for additional information pertaining to the Seabrook LRA, October 21, 2010 (ADAMS Accession No. ML102980693)

January 3, 2011 Summary of the telephone conference call between NRC and NextEra concerning the draft request for additional information pertaining to the Seabrook LRA, December 21, 2010 (ADAMS Accession No. ML103570401)

January 13, 2011 Letter from NextEra, SeabrookResponse to Request for Additional Information, NextEra Energy License Renewal Application (ADAMS Accession No. ML110140810)

February 18, 2011 Letter from NextEra, Seabrook Station Environmental Permit Renewals, NextEra Energy Seabrook License Renewal Environmental Report (ADAMS Accession No. ML110550161)

February 28, 2011 Summary of telephone conference calls held between NRC and NextEra concerning the responses to the SAMA RAIs, February 15, 2011 (ADAMS Accession No. ML110490165)

E-4

Appendix E March 1, 2011 Summary of telephone conference call held between NRC and NextEra concerning the essential fish habitat in the vicinity of Seabrook, February 3, 2011 (ADAMS Accession No.

ML1105603625)

March 1, 2011 Letter from NRC to NextEra, Issuance of Environmental Scoping Summary Report Associated with the Staff's Review of the Application by NextEra Energy Seabrook, LLC for Renewal of the Operating License for Seabrook Station (TAC Number ME3959) (ADAMS Accession No. ML110100113)

March 4, 2011 Letter from NRC to NextEra, Schedule Revision and Request for Additional Information for the Review of the Seabrook Station License Renewal Application Environmental Review (TAC ME3959) (ADAMS Accession No. ML110590638)

March 16, 2011 Letter from NextEra to NRC, Seabrook StationResponse to Request for Additional Information, NextEra Energy Seabrook License Renewal Environmental Report (ADAMS Accession No. ML110820121)

April 8, 2011 Summary of telephone conference call held between NRC and NextEra to clarify responses to RAIs, March 21, 2011 (ADAMS Accession No. ML110811326)

April 18, 2011 Letter from NextEra, SeabrookResponse to Request for Additional Information, NextEra Energy Seabrook License Renewal Application (ADAMS Accession No. ML11122A075)

May 12, 2011 Letter from NRC to NextEra, Schedule Revision for the Environmental Review of the Seabrook Station License Renewal Application (TAC Number ME3959) (ADAMS Accession No. ML110890319)

June 10, 2011 Letter from NextEra, SeabrookSupplement to Response to Request for Additional Information, NextEra Energy Seabrook License Renewal Application (ADAMS Accession No. ML11166A255) 1 E-5

APPENDIX F U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION OF SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR SEABROOK STATION UNIT 1 IN SUPPORT OF LICENSE RENEWAL APPLICATION REVIEW

Appendix F 1 F U.S. NUCLEAR REGULATORY COMMISSION STAFF 2 EVALUATION OF SEVERE ACCIDENT MITIGATION 3 ALTERNATIVES FOR SEABROOK STATION UNIT 1 IN SUPPORT 4 OF LICENSE RENEWAL APPLICATION REVIEW 5 F.1 Introduction 6 NextEra Energy Seabrook, LLC (NextEra), submitted an assessment of severe accident 7 mitigation alternatives (SAMAs) for the Seabrook Station (Seabrook) Unit 1 as part of its 8 environmental report (ER) (NextEra, 2010). This assessment was based on the most recent 9 Seabrook probabilistic risk assessment (PRA) available at that time, a plant-specific offsite 10 consequence analysis performed using the Methods for Estimation of Leakages and 11 Consequences of Releases (MELCOR) Accident Consequence Code System 2 (MACCS2) 12 computer code (NRC, 1998a), and insights from the Seabrook individual plant examination 13 (IPE) (NHY, 1991) and individual plant examination of external events (IPEEE) (NAESC, 1992).

14 In identifying and evaluating potential SAMAs, NextEra considered SAMA candidates that 15 addressed the major contributors to core damage frequency (CDF) and large early release 16 frequency (LERF) at Seabrook, as well as a generic list of SAMA candidates for pressurized 17 water reactor (PWR) plants identified from other industry studies. NextEra identified 191 18 potential SAMA candidates. This list was reduced to 74 SAMA candidates by eliminating 19 SAMAs for the following reasons:

20

• Seabrook having a different design 21

• the SAMA having already been implemented at Seabrook 22

• having already met the intent of the SAMA at Seabrook 23

• combining the SAMA with another SAMA candidate that is similar in nature 24

• having estimated implementation costs that would exceed the dollar value associated 25 with eliminating all severe accident risk at Seabrook 26

• being related to a non-risk significant system and therefore the SAMA is of very low 27 benefit 28 NextEra assessed the costs and benefits associated with each of these 74 potential SAMAs and 29 concluded in the ER that several of the candidate SAMAs evaluated are potentially cost 30 beneficial.

31 Based on a review of the SAMA assessment, the U.S. Nuclear Regulatory Commission (NRC) 32 issued requests for additional information (RAIs) to NextEra by letters dated November 16, 2010 33 (NRC, 2010a), and March 4, 2011 (NRC, 2011b). Key questions in these RAIs concerned the 34 following:

35

• additional details regarding the plant-specific PRA model and changes to internal and 36 external event CDF and LERF since the IPE F-1

Appendix F 1

• the process used to map Level 1 PRA results into the Level 2 analysis and group 2 containment event tree (CET) end states into release categories1 3

• the process for selecting the representative Modular Accident Analysis Program (MAAP) 4 case for each release category and the release characteristics of each representative 5 case 6

• changes to the fire and seismic PRA models since the IPEEE 7

• the impact of updated seismic hazard curves 8

• the sensitivity of the SAMA results to assumptions used in the Level 3 analysis 9

• the use of Level 2 importance analysis and industry SAMA analyses in identifying 10 plant-specific SAMAs 11

• further information on the cost-benefit analysis of several specific candidate SAMAs and 12 low-cost alternatives 13 NextEra submitted additional information to the NRC by letters dated January 13, 2011 14 (NextEra, 2011a), and April 18, 2011 (NextEra, 2011b). NextEra provided additional information 15 in a telephone conference call with the NRC staff on February 15, 2011 (NRC, 2011a). In 16 response to the RAIs, NextEra provided the following:

17

• the internal and external event contribution to CDF and LERF for each version of the 18 Seabrook PRA model and model changes that most impacted CDF and LERF 19

• a description of the CET and the process for determining the frequency of each release 20 category 21

• a description of the process for selecting representative MAAP cases for each release 22 category and the characteristics of each plume in each release category 23

• changes to the fire and seismic PRA models since the IPEEE 24

• a sensitivity analysis of the impact on the SAMA analysis from updated seismic hazard 25 curves 26

• the results of the sensitivity analyses performed on the assumptions used in the Level 3 27 analysis 28

• listings of the important basic events for the most risk-significant release categories 29

• the SAMA candidates that mitigate each important basic event 30

• a review of the applicability of industry cost-effective SAMA candidates to Seabrook 31

• additional information regarding several specific SAMAs 32 NextEras responses addressed the NRC staffs concerns and resulted in the identification of 33 additional potentially cost-beneficial SAMAs.

1 The NRC uses Probabilistic Risk Assessment (PRA) to estimate risk by computing real numbers to determine what can go wrong, how likely is it, and what are its consequences. Thus, PRA provides insights into the strengths and weaknesses of the design and operation of a nuclear power plant. For the type of nuclear plant currently operating in the United States, a PRA can estimate three levels of risk. A Level 1 PRA estimates the frequency of accidents that cause damage to the nuclear reactor core. This is commonly called core damage frequency (CDF). A Level 2 PRA, which starts with the Level 1 core damage accidents, estimates the frequency of accidents that release radioactivity from the nuclear power plant. A Level 3 PRA, which starts with the Level 2 radioactivity release accidents, estimates the consequences in terms of injury to the public and damage to the environment.

(http://www.nrc.gov/about-nrc/regulatory/risk-informed/pra.html)

F-2

Appendix F 1 An assessment of SAMAs for Seabrook is presented below.

2 F.2 Estimate of Risk for Seabrook 3 NextEras estimates of offsite risk at Seabrook are summarized in Section F.2.1. The summary 4 is followed by the NRC staffs review of NextEras risk estimates in Section F.2.2.

5 F.2.1 NextEras Risk Estimates 6 Two distinct analyses are combined to form the basis for the risk estimates used in the SAMA 7 analysis: (1) the Seabrook Level 1 and 2 PRA model, which is an updated version of the IPE 8 (NHY, 1991), and (2) a supplemental analysis of offsite consequences and economic impacts 9 (essentially a Level 3 PRA model) developed specifically for the SAMA analysis. The SAMA 10 analysis is based on the most recent Seabrook Level 1 and Level 2 PRA models available at the 11 time of the ER, referred to as SSPSS-2006 (the model-of-record used to support SAMA 12 evaluation). The scope of this Seabrook PRA includes both internal and external events.

13 The Seabrook CDF is approximately 1.5x10-5 per year for both internal and external events as 14 determined from quantification of the Level 1 PRA model. A truncation level of 1x10-14 per year 15 was used when quantifying event tees, and a truncation value of 1x10-12 per year was used 16 when quantifying fault tees, except for the service water system (SWS) (NextEra, 2011a). The 17 SWS was divided into two trains, which were each solved at a truncation level of 1x10-12 per 18 year. The CDF is based on the risk assessment for internally-initiated events, which include 19 internal flooding, and external events, which include fire and seismic events. The internal 20 events CDF is approximately 1.1x10-5 per year, and the external events CDF (i.e., fire and 21 seismic events) is approximately 4.5x10-6 per year (NextEra, 2011a).

22 The breakdown of CDF by initiating event is provided in Table F-1 and includes internal, fire, 23 and seismic initiating events. As shown in Table F-1, the largest single contributor to the total 24 CDF is loss of offsite power (LOOP) due to weather. NextEra identified that station blackout 25 (SBO) contributes approximately 5.3x10-6 per year, or 35 percent, and anticipated transients 26 without scram (ATWS) contribute approximately 4.6x10-7 per year, or 3 percent, to the total 27 internal and external events CDF.

28 The Level 2 Seabrook PRA model that forms the basis for the SAMA evaluation is an updated 29 version of the Level 2 IPE model (NHY, 1991) and IPEEE model (NAESC, 1992). The current 30 Level 2 model uses a single CET that is used to address internal, fire, and seismic events. The 31 CET addresses both phenomenological and systemic events. The Level 1 core damage 32 sequences are linked directly with the CET, so all Level 1 sequences are evaluated by the CET 33 (NRC, 2011a). The CET probabilistically evaluates the progression of the damaged core with 34 respect to release to the environment. CET nodes are evaluated using supporting fault trees 35 and logic rules. The CET end states then are examined for considerations of timing and 36 magnitude of release and assigned to release categories.

F-3

Appendix F 1

2 Table F-1. Seabrook CDF for internal and external events Internal initiating event CDF  % contribution to (per year) total CDF (a)

LOOP due to weather 1.5x10-6 10 Loss of essential alternating current (AC) power 4 kilovolt (kV) bus 9.5x10-7 6

-7 Reactor tripcondenser available 9.3x10 6 LOOP due to grid related events 9.0x10-7 6 LOOP due to hardware or maintenance 8.1x10-7 5

-7 Flood in turbine building 7.3x10 5 Steam generator tube rupture (SGTR) 5.9x10-7 4

-7 Loss of primary component cooling system (CS) train 5.3x10 4 Loss of essential direct current (DC) power 125V DC bus 3.9x10-7 3 Reactor tripduring shutdown 3.5x10-7 2

-7 Interfacing systems loss-of-coolant accident (ISLOCA) 3.4x10 2 Large loss-of-coolant accident (LOCA) 3.4x10-7 2 Medium LOCA 3.3x10-7 2 Excessive LOCA 2.5x10-7 2 Inadvertent safety injection (SI) 2.5x10-7 2

-7 Small LOCA 1.9x10 1

-7 Reactor trip with no condenser cooling 1.7x10 1 (b)

Other internal events 1.0x10-6 7 (c) -5 Total internal events CDF 1.1x10 70 Fire initiating event Fire switchgear (SWGR) room Bloss of bus E6 3.7x10-7 2

-7 Fire SWGR room Aloss of bus E5 3.7x10 2

-7 Fire control roomAC power loss 2.1x10 1

-7 Fire control roompower-operated relief valve (PORV) LOCA 1.4x10 1 (d)

Other fire events 2.3x10-7 2 (e)

Total fire events CDF 1.3x10-6 9 Seismic initiating event Seismic 0.7 g transient event 9.2x10-7 6 Seismic 1.0 g transient event 8.7x10-7 6

-7 Seismic 1.4 g transient event 3.6x10 2 Seismic 1.0 g ATWS 1.1x10-7 1 F-4

Appendix F Internal initiating event CDF  % contribution to (per year) total CDF (a)

Seismic 1.4 g large LOCA 1.1x10-7 1 Seismic 0.7 g ATWS 1.0x10-7 1

-8 Seismic 1.0 g large LOCA 8.9x10 1 Other seismic events(f) 4.9x10-7 3 (e)

Total seismic events CDF 3.1x10-6 21 (g) -5 Total CDF (internal and external events) 1.5x10 100 (a)

May not total to 100 percent due to round off (b)

Obtained by subtracting the sum of the internal initiating event contributors to internal event CDF from the total internal events CDF (c)

Obtained from percentage contribution of internal events provided in response to RAI 1.b.1 (NextEra, 2011a) times the total internal and external events CDF (d)

Obtained by subtracting the sum of the fire initiating event contributors to fire event CDF from the total fire events CDF (e)

Provided in response to conference call clarification #2 (NRC, 2011a)

(f)

Obtained by subtracting the sum of the seismic initiating event contributors to seismic event CDF from the total seismic events CDF (g)

Provided in response to RAI 1.b.1 (NextEra, 2011a) 1 The quantified CET sequences are binned into a set of 14 release categories, which are 2 subsequently grouped into 10 source term categories that provide the input to the Level 3 3 consequence analysis (NextEra, 2011a). The frequency of each source term category was 4 obtained by summing the frequency of the individual accident progression CET endpoints, or 5 release categories, assigned to each source term category. Source terms were developed for 5 6 of the 10 release categories using the results of MAAP Version 4.0.5 computer code 7 calculations. Source terms for the other five release categories were taken from original 8 analyses to support the Seabrook PRA. The results for Seabrook are provided in 9 Table F.3.4.3-2 to the ER (NextEra, 2010).

10 The offsite consequences and economic impact analyses use the MACCS2 code to determine 11 the offsite risk impacts on the surrounding environment and public. Inputs for these analyses 12 include plant-specific and site-specific input values for core radionuclide inventory, source term 13 and release characteristics, site meteorological data, projected population distribution within an 14 80-kilometer (km) (50-mile (mi)) radius for the year 2050, emergency response evacuation 15 planning, and economic parameters. The core radionuclide inventory corresponds to the 16 end-of-cycle values for Seabrook operating at 3,659 megawatts thermal (MWt), which is slightly 17 above the current licensed power level of 3,648 MWt. The magnitude of the onsite impacts (in 18 terms of clean-up and decontamination costs and occupational dose) is based on information 19 provided in NUREG/BR-0184 (NRC, 1997a).

20 In the ER, NextEra estimated the dose to the population within 80 km (50 mi) of the Seabrook 21 site to be approximately 0.107 person-Sievert (Sv) (10.7 person-rem) per year. The breakdown 22 of the total population dose by containment release mode is summarized in Table F-2 (NextEra, 23 2011a). Small early and large late releases are the dominant contributors to population dose 24 risk at Seabrook.

F-5

Appendix F 1 Table F-2. Breakdown of population dose by containment release mode Containment release mode Population dose (person-rem(a) per year) Percent contribution Small early releases 5.3 49 Large early releases 1.6 15 Large late releases 3.8 36 Intact containment negligible negligible Total 10.7 100 (a)

One person-rem = 0.01 person-Sv 2 F.2.2 Review of NextEras Risk Estimates 3 NextEras determination of offsite risk at Seabrook is based on the following major elements of 4 analysis:

5

• the Level 1 and 2 risk models that form the bases for the 1991 IPE submittal 6 (NHY, 1991) and the external event analyses of the 1992 IPEEE submittal 7 (NAESC, 1992), and the major modifications to the IPE and IPEEE models that have 8 been incorporated in the Seabrook PRA, including a complete revision of the Level 2 risk 9 model 10

• the MACCS2 analyses performed to translate fission product source terms and release 11 frequencies from the Level 2 PRA model into offsite consequence measures (essentially 12 this equates to a Level 3 PRA) 13 Each of these analyses was reviewed to determine the acceptability of the Seabrook risk 14 estimates for the SAMA analysis, as summarized below.

15 The first Seabrook PRA was completed in December 1983, its purpose being to provide a 16 baseline risk assessment and an integrated plant and site model for use as a risk management 17 tool. This model was subsequently updated in 1986, 1989, and 1990, with the last update used 18 to support the IPE.

19 The NRC staffs review of the Seabrook IPE is described in an NRC report dated March 1, 1992 20 (NRC, 1992). Based on a review of the original IPE submittal and responses to RAIs, the NRC 21 staff concluded that the IPE submittal met the intent of Generic Letter (GL) 88-20 (NRC, 1988).

22 That is, the licensee demonstrated an overall appreciation of severe accidents, had an 23 understanding of the most likely severe accident sequences that could occur at Seabrook, and 24 had gained a quantitative understanding of core damage and fission product release. Although 25 no severe accident vulnerabilities were identified in the Seabrook IPE, 14 potential plant 26 improvements were identified. Four of the improvements have been implemented. Each of the 27 10 improvements not implemented is addressed by a SAMA in the current evaluation and is 28 discussed further in Section F.3.2.

29 The internal events CDF value from the 1991 Seabrook IPE (6.1x10-5 per year) is near the 30 average of the range of the CDF values reported in the IPEs for Westinghouse four-loop plants.

31 Figure 11.6 of NUREG-1560 shows that the IPE-based internal events CDF for these plants 32 range from about 3x10-6 per year to 2x10-4 per year, with an average CDF for the group of 33 6x10-5 per year (NRC, 1997b). It is recognized that plants have updated the values for CDF F-6

Appendix F 1 subsequent to the IPE submittals to reflect modeling and hardware changes. Based on CDF 2 values reported in the SAMA analyses for license renewal applications (LRAs), the internal 3 events CDF result for Seabrook used for the SAMA analysis (1.1x10-5 per year, including 4 internal flooding) is somewhat lower than that for most other plants of similar vintage and 5 characteristics.

6 There have been 10 revisions to the IPE model since the 1991 IPE submittal, and 3 revisions to 7 the PRA model, as discussed previously, from the original 1983 PRA model to the 1990 update 8 used to support the IPE submittal. The SSPSA-2006 model was used for the SAMA analysis (a 9 subsequent revision, SSPSA-2009, resulted in a reduction in CDF, but the SAMA analysis was 10 not revised to reflect this revision). A listing of the major changes in each revision of the PRA, 11 and the associated change in internal and external event CDF, was provided in the ER 12 (NextEra, 2010) and in response to an NRC staff RAI (NextEra, 2011a) and is summarized in 13 Table F-3. A comparison of the internal events CDF between the 1991 IPE and the 2006 PRA 14 model used for the SAMA evaluation indicates a decrease of approximately 82 percent (from 15 6.1x10-5 per year to 1.1x10-5 per year). This decrease results from the significant changes 16 shown, while the external events CDF has increased by approximately 25 percent since the 17 1993 IPEEE (from 3.6x10-5 per year to 4.5x10-5 per year).

18 Table F-3. Seabrook PRA historical summary External Internal events PRA Total CDF Summary of significant changes from prior model(a) events CDF CDF version (per year)

(per year)(b) (per year)(b)

-4 SSPSA- Original modelincludes internal, fire, and seismic events 2.3x10-4 1.8x10 4.6x10-5 PLG-0300 (1983)

SSPSS-

• Updated allowed outage times to reflect current 2.9x10-4 Not provided Not 1986 technical specifications provided

• Revised models of the inservice test pump test frequency; turbine driven emergency feedwater (EFW) pump atmospheric relief valves (ARVs); boron injection tank, pump, and lines; enclosure building air handling system; reactor trip breakers; & reactor cooling pump (RCP) thermal barrier CS

• Improved quantification traceability & documentation

• Updated seismic fragilities

• Expanded common cause treatment

-5 SSPSS-

• Updated initiating event frequencies 1.4x10

-4 9.5x10 4.5x10-5 1989

• Updated common cause & maintenance distributions

• Revised electric power recovery model using current data

• Added recovery actions into event model

-4 SSPSS- IPE submittal 1.1x10 6.1x10-5 5.0x10-5 1990

• Added modeling of ATWS mitigation system

• Updated electric power recovery model F-7

Appendix F External Internal events PRA Total CDF Summary of significant changes from prior model(a) events CDF CDF version (per year)

(per year)(b) (per year)(b)

• Updated RCP seal LOCA analysis

• Added new recovery actions

• Revised CET to explicitly model induced SGTR & direct containment heating

-5 SSPSS- IPEEE submittal 8.0x10 4.4x10-5 3.6x10-5 1993

• Added plant-specific data for main safety pumps &

diesel generators (DGs)

• Improved fire event modeling, including modeling operator actions & addition of new fire hazard initiating events

• Revised startup feed pump (SUFP) model to conservatively require manual startup

• Improved modeling of high-pressure injection (HPI) and event tree logic

-5 SSPSS-

• Improved common cause modeling of primary closed 4.3x10 2.1x10-5 2.2x10-5 1996 cooling (PCC) with opposite PCC train failure

• Updated ATWS model to account for change from an 18-month to 24-month fuel cycle

• Increased use of plant-specific data

• Changed definition of LERF to include steam leak from SGTR

• Increased failure likelihood for small containment penetrations in seismic sequences

• Added credit for manual operator action to close RCP seal return line motor-operated valve (MOV)

SSPSS-

• Updated LOCA initiator frequencies 4.6x10-5 2.7x10-5 1.9x10-5 1999

• Updated ATWS model to account for change from a 24-month to an 18-month fuel cycle and to use more current failure rates

• Updated event tree to explicitly incorporate RCP seal LOCA model & related power recovery models

• Changed emergency diesel generator (EDG) mission time from 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for weather-related LOOP

& similar initiators

• Moved LOOP & internal flooding models from external to internal events model

• Modified common cause factors & mission times for PCC system & SWS

• Updated human error probability (HEP) event tree rules

& quantification SSPSS-

• Transitioned PRA software from DOS-based 4.6x10-5 2.7x10-5 1.9x10-5 2000 RISKMAN 9.2 to Windows-based RISKMAN 3.0 F-8

Appendix F External Internal events PRA Total CDF Summary of significant changes from prior model(a) events CDF CDF version (per year)

(per year)(b) (per year)(b)

SSPSS-

• Changed system initiator models 4.8x10-5 2.8x10-5 2.0x10-5 2001 SSPSS-

• Integrated shutdown & low power risk models into all- 4.8x10-5 2.5x10-5 2.0x10-5 2002 modes model SSPSS-

• Updated the human reliability analysis (HRA) 3.0x10-5 1.7x10-5 1.3x10-5 2004

• Added credit for the supplemental electric power system (SEPS) DG

• Updated the LERF model to include consequential SGTR SSPSS-

• Revised success criteria & operator timing 1.4x10-5 9.5x10-6 4.5x10-6 2005

• Updated the seismic PRA

• Updated DG failure rate & unavailability data

• Updated the Level 2 analysis including modeling of severe accident management guideline (SAMG) actions SSPSS-

• Updated the Mode 4, 5, & 6 shutdown model 1.5x10-5 1.1x10-5 4.5x10-6 2006(c)

• Revised modeling of PCC & SWS initiators

-5 SSPSS-

• Updated plant-specific data & generic data distributions 1.2x10 7.1x10-6 4.9x10-6 2009

• Incorporated electric power convolution model

• Expanded the steam generator model to include condenser cooling, circulating water, & condenser steam dump

• Revised operator action modeling (a)

Summarized from information provided in the ER and in response to an NRC staff RAI (NextEra, 2011a)

(b)

Estimated from percent contribution to total CDF provided in response to an NRC staff RAI (NextEra, 2011a)

(c)

PRA model revision used in the SAMA analysis 1 The NRC staff considered the peer reviews performed for the Seabrook PRA and the potential 2 impact of the review findings on the SAMA evaluation. In the ER (NextEra, 2010), NextEra 3 identifies two peer reviews that have been performed on the PRAa 1999 Westinghouse 4 Owners Group (WOG) certification peer review and a 2005 focused peer review against the 5 American Society of Mechanical Engineers (ASME) PRA standard (ASME, 2003). In response 6 to an NRC staff RAI, NextEra clarified the scope of these peer reviews with the 1999 peer 7 review. It provided a full review of the technical elements of the Level 1 and 2 LERF internal 8 events models, including internal flooding and the 2005 peer review providing a focused scope 9 examination of Level 1 internal events accident sequences, success criteria, post-initiating event 10 HRA, and configuration control (NextEra, 2011a). Neither the 1999 nor the 2005 peer review 11 included examination of external flooding, fire, or seismic hazards. The 1999 certification peer 12 review identified 30 Category A and B facts and observations (F&O), and the 2005 focused peer F-9

Appendix F 1 review identified 4 Category A and B F&Os.2 The applicant provides the resolution of each of 2 the 34 F&Os in the ER and states that all have been dispositioned and implemented in the PRA 3 model.

4 The NRC staff requested that NextEra clarify how the resolution to F&O 3aggressive load 5 shedding and the available cross tie can extend battery life from 8-12 hoursaddresses the 6 F&O. The NRC asked NextEra to assess the ability of the operators to successfully cool the 7 core using the EFW pump without underfeeding the steam generators (NRC, 2010a). In 8 response to the RAI, NextEra clarified that during an extended SBO condition, the normal 9 control instrumentation and procedures for which operators are trained and with which they are 10 familiar would be used to maintain long-term control of steam generator water level (NextEra, 11 2011a).

12 The NRC staff asked NextEra to summarize the scope and unresolved findings from any other 13 reviews performed on the Seabrook PRA (NRC, 2010a). In response to the RAI, NextEra 14 explained that many other internal reviewsincluding vendor-assisted reviewshave been 15 performed on specific model updates, and comments from these reviewsalong with plant 16 changes and potential model enhancementsare tracked through a model change database to 17 assure that the comments are addressed in the periodic update process (NextEra, 2011a).

18 NextEra also noted that a peer review was conducted in late 2009, after the SAMA evaluation, 19 focusing exclusively on internal flooding. NextEra stated that unresolved comments from these 20 reviews primarily reflect model completeness and documentation issues, and they are not 21 significant to the results and conclusions of the PRA and were judged not to have a significant 22 impact on the SAMA evaluation.

23 The NRC staff asked NextEra to identify any changes to the plant, including physical and 24 procedural modifications, since the SSPSA-2006 PRA model that could have a significant 25 impact on the results of the SAMA analysis (NRC, 2010a). In response to the RAI, NextEra 26 stated that there have been no major plant changes since PRA model SSPSS-2006 was issued 27 that could significantly impact the SAMA analysis. NextEra further identified the specific plant 28 and model changes made to the PRA model that resulted in the 2009 periodic update of the 29 model, referred to as PRA model SPSS-2009 (NextEra, 2011a). NextEra explained that the 30 model changes resulted in a total CDF decrease of about 19 percent (i.e., from 1.5x10-5 per 31 year for SSPSS-2006 to 1.2x10-5 per year for SPSS-2009) and resulted in no significant shift in 32 the relative importance of initiating events or components. Based on these results, NextEra 33 judged that changes incorporated into the SSPSA-2009 model would not have a significant 34 impact on the overall SAMA results. NextEra also explained that the SSPSS-2010 model 35 scheduled to be issued in 2011 is being upgraded to meet the internal flooding requirements in 36 the ASME PRA standard (ASME, 2009), and insights from this upgrade indicate that control 37 building flooding scenarios will dominate the risk of internal flooding. Based on this, NextEra 38 identified a SAMA, install a globe valve or flow limiting orifice upstream in the fire protection 39 system, to mitigate the risk of control building flooding, which is discussed further in 40 Section F.6.2. Based on the reduction in the total CDF since revision SSPSS-2006 of the 41 Seabrook PRA model used for the SAMA analysis and that revision SSPSS-2009 of the PRA 42 model does not change the relative importance of initiating events and plant components, the 43 NRC staff concludes that PRA model and plant changes made since SSPSA-2006, other than 2 Now termed a "Finding," a Category A or B F&Os is an "observation (an issue or discrepancy) that is necessary to address to ensure: [1] the technical adequacy of the PRA ... [2] the capability/robustness of the PRA update process, or [3] the process for evaluating the necessary capability of the PRA technical elements (to support applications)." (NEI 05-04, "Process for Performing Internal Events PRA Peer Reviews Using the ASME/ANS PRA Standard, " Rev. 2, 2008)

F-10

Appendix F 1 changes made to the internal flooding model, are not likely to impact the results of the SAMA 2 analysis.

3 The NRC staff asked NextEra to describe the PRA quality control process used at Seabrook 4 (NRC, 2010a). NextEra responded that an existing administrative procedure defines the quality 5 control process for updates to the Seabrook PRA, and the process is consistent with 6 requirements of the ASME 2009 PRA standard (ASME, 2009) and ensures that the PRA model 7 accurately reflects the current Seabrook plant design, operation, and performance 8 (NextEra, 2011a). The quality control process includes monitoring PRA inputs for new 9 information, recording new applicable information, assessing the significance of new 10 information, performing PRA revisions, and controlling computer codes and models. NextEra 11 also stated that the PRA training qualification is performed as part of the Engineering Support 12 Personnel Training Program.

13 Given that the Seabrook internal events PRA model has been peer-reviewed and the peer 14 review findings were all addressed, and that NextEra has satisfactorily addressed NRC staff 15 questions regarding the PRA, the NRC staff concludes that the internal events Level 1 PRA 16 model is of sufficient quality to support the SAMA evaluation.

17 The Seabrook PRA model is an integrated internal and external events model in that it includes 18 seismic-initiated, fire-initiated, and external flooding-initiated events as well as internal initiating 19 events. The external events models have been integrated with the internal events model since 20 the initial 1983 PRA (NextEra, 2011a). The external events models used in the SAMA 21 evaluation are essentially those used in the IPEEE, with the exception of the seismic PRA 22 model, which underwent a major update for the SSPSA-2005 model. The updated external 23 events CDF results are described in a response to an NRC staff RAI (NextEra, 2011a) and are 24 included in Table F-3 along with the internal events results.

25 The Seabrook IPEEE was submitted October 2, 1992 (NAESC 1992), in response to 26 Supplement 4 of GL 88-20 (NRC, 1991). The submittal used the same PRA as was used for 27 the IPE (i.e., SSPSA-1990) except for updates to the external events. No fundamental 28 weaknesses or vulnerabilities to severe accident risk in regard to the external events were 29 identified. Improvements that have already been realized as a result of the IPEEE process 30 minimized the likelihood of there being cost-beneficial enhancements as a result of the SAMA 31 analysis, especially with the inclusion of a multiplier to account for the additional risk of seismic 32 events. In a letter dated May 2, 2001, the NRC staff concluded that the submittal met the intent 33 of Supplement 4 to GL 88-20 and the licensees IPEEE process is capable of identifying the 34 most likely severe accidents and severe accident vulnerabilities (NRC, 2001).

35 The Seabrook IPEEE seismic analysis used a seismic PRA following NRC guidance 36 (NRC, 1991a). The seismic PRA included a seismic hazard analysis, a seismic fragility 37 assessment, seismic quantification to yield initiating event frequencies and conditional system 38 failure probabilities, and plant model assembly to integrate seismic initiators and 39 seismic-initiated component failures with random hardware failures and maintenance 40 unavailabilities.

41 The seismic hazard analysis estimated the annual frequency of exceeding different levels of 42 ground motion. Seabrook seismic CDFs were determined for site-specific, Electric Power 43 Research Institute (EPRI) EPRI (EPRI, 1989) and Lawrence Livermore National Laboratory 44 (LLNL) (NRC, 1994) hazard curves. The seismic fragility assessment was performed by 45 walkdowns that were conducted at the time of the original seismic PRA in 1982-1983, 46 walkdowns performed for a revised fragility analysis in 1986, and supplemental walkdowns F-11

Appendix F 1 performed in 1991 for the IPEEE, using procedures and screening caveats in EPRIs seismic 2 margin assessment methodology (EPRI, 1988). Fragility calculations were made for about 3 82 components using a screening criterion of median peak ground acceleration (PGA) of 2.0 g, 4 which corresponds to a high confidence (95 percent) low probability (5 percent) of failure 5 (HCLPF) capacity. A total of 15 components and 2 sets of relay groups were further assessed.

6 Fragility calculations were also made for eight buildings and structures and HCLPF values 7 determined. The seismic systems analysis defined the potential seismic induced structure and 8 equipment failure scenarios that could occur after a seismic event and lead to core damage.

9 The Seabrook IPE event tree and fault tree models were used as the starting point for the 10 seismic analysis. Quantification of the seismic models consisted of convoluting the seismic 11 hazard curve with the appropriate structural and equipment seismic fragility curves to obtain the 12 frequency of the seismic damage state. The conditional probability of core damage, given each 13 seismic damage state, was then obtained from the IPE models with appropriate changes to 14 reflect the seismic damage state. The CDF was given based on the product of the seismic 15 damage state probability and the conditional core damage probability.

16 Quantification of the seismic CDF for Seabrook was performed in nine discrete ground 17 acceleration ranges between 0.1-2.0 g. The seismic CDF resulting from the Seabrook IPEEE 18 was calculated to be 1.2x10-5 per year using a site-specific seismic hazard curve, with sensitivity 19 analyses yielding 1.3x10-4 per year using the LLNL seismic hazard curve and 6.1x10-6 per year 20 using the EPRI seismic hazard curve. The Seabrook IPEEE did not identify any vulnerability 21 due to seismic events but did identify two plant improvements to reduce seismic risk. Neither of 22 the two improvements has been implemented. Each of the two improvements is addressed by 23 a SAMA in the current evaluation and is discussed further in Section F.3.2.

24 Subsequent to the IPEEE, NextEra updated the seismic PRA analysis. The NRC staff asked 25 NextEra to describe the changes to the seismic analysis incorporated in the PRA model 26 SSPSA-2005 update and to explain the reasons for any significant changes to the seismic CDF 27 (NRC, 2011a). In response to the RAI, NextEra stated that the most significant changes to the 28 IPEEE seismic model made in the SSPSA-2005 update of the Seabrook PRA were as follows 29 (NextEra, 2011a):

30

• The fragility analysis was updated to extend the fragility screening of equipment from 31 greater than 2.0 g to the range from 2.0-2.5 g and greater than 2.5 g to better capture 32 seismic risk.

33

• The EPRI hazard curve was adopted and used to update the equipment fragilities. The 34 site-specific hazard curve was replaced with the EPRI hazard curve because the EPRl 35 uniform hazard spectrum (UHS) developed for the Seabrook site is more current and 36 realistic than that used in the original 1983 and the IPEEE PRA. In response to a 37 followup NRC staff RAI, NextEra further clarified that the EPRI UHS was judged to be 38 more realistic and representative of the best estimate hazard because of overall general 39 improvement in seismic technology from the early 1980s to 1989, when the EPRI hazard 40 curve was developed (NextEra, 2011b). The probabilistic estimates of seismic capacity 41 of structures and components were updated to reflect component-specific fragility 42 information and the EPRI UHS.

43

• Several new component fragilities were added to the seismic PRA model, including 44 seismic fragilities for the SEPS DGs, which had been added to the plant since the 45 IPEEE.

F-12

Appendix F 1

• Modeling and documentation of operator actions credited in the seismic PRA were 2 improved.

3 NextEra also compared the dominant contributors to the seismic CDF from the IPEEE PRA 4 model and to the dominant contributors from the current seismic PRA analysis or SSPSA-2009 5 model, which is presented in Table F-4. NextEra clarified in a conference call that the seismic 6 CDF for the SSPSA-2009 model is essentially the same as that for the SSPSA-2006 PRA 7 model used in the SAMA evaluation (NRC, 2011a).

8 Table F-4. Dominant contributors to seismic CDF

% Contribution to seismic CDF Seismic initiating event group IPEEE SSPSA-2009(a)

Seismic transient total 78 65 Seismic ATWS total 11 24 Seismic LLOCA total 10 11 Other seismic groups 1 1

-5 Total seismic CDF 1.2x10 3.1x10-6 (a) -6 The seismic CDF for PRA model SSPSA-2009 (3.1x10 per year) is essentially unchanged from the seismic CDF for PRA

-6 model SSPSA-2006 model (3.1x10 per year) used in the SAMA evaluation.

9 NextEra stated that the most recognizable conservatism in the seismic model is the use of 10 complete correlation of the fragility between identical components, such as both EDGs are 11 assumed to fail at the same seismic hazard level (NextEra, 2011a). NextEra further stated that 12 extensive internal technical reviews of the seismic PRA analysis were performed for the original 13 1983 PRA, when the seismic analysis was revised for the IPEEE, and when the seismic 14 analysis was revised for the SSPSA-2005 PRA model update. No significant comments were 15 documented from these reviews, and no formal peer reviews have been conducted on the 16 seismic PRA model (NextEra, 2011a).

17 The NRC staff noted that, in the attachments to NRC Information Notice 2010-18, Generic Issue 18 199 (NRC 2010b), the NRC staff estimated a seismic CDF for Seabrook of between 5.9x10-6 19 per year and 2.2x10-5 per year using updated seismic hazard curves developed by the U.S.

20 Geological Survey (USGS) in 2008 (USGS, 2008). The NRC staff asked that NextEra provide 21 an assessment of the impact of the updated USGS seismic hazard curves on the SAMA 22 evaluation (NRC, 2010a). In response to the RAI, NextEra provided a revised SAMA evaluation 23 using multipliers of 2.1 and 2.6 to account for the maximum GI-199 seismic CDF of 2.2x10-5 per 24 year, which is discussed further below (NextEra, 2011a; NextEra, 2011b).

25 Considering the following points, the NRC staff concludes that the seismic PRA model, in 26 combination with the use of a seismic events multiplier, provides an acceptable basis for 27 identifying and evaluating the benefits of SAMAs:

28

• The Seabrook seismic PRA model is integrated with the internal events PRA.

29

• The seismic PRA has been updated to include additional components and to extend the 30 fragility-screening threshold.

F-13

Appendix F 1

• The SAMA evaluation was updated using a multiplier to account for a potentially higher 2 seismic CDF.

3

• NextEra has satisfactorily addressed NRC staff RAIs regarding the seismic PRA.

4 The Seabrook IPEEE fire analysis, which was significantly updated from the original fire 5 analysis completed in 1983, employed EPRIs fire-induced vulnerability evaluation (FIVE) 6 methodology (EPRI, 1992) to calculate area fire frequencies, quantitatively screen areas, and 7 provide hazards analysis for resulting critical areas. The quantification of CDF was obtained by 8 propagating fire-induced initiating events through the PRA used for the IPE.

9 The IPEEE fire areas were based on definitions of Appendix R fire areas for Seabrook.

10 Qualitative screening was performed using a spatial database specifically developed for the 11 IPEEE fire analysis that identified equipment important in initiating or mitigating an accident. Of 12 the 73 fire areas, 13 were determined to contain important equipment (pumps, valves, and 13 cabling, etc.) and were further assessed. Quantitative screening used industry fire data and the 14 assumption that a fire in a compartment damaged all equipment and cables in the compartment.

15 The resulting fire-initiating events are propagated through the appropriate event tree models.

16 Using fire frequencies and conditional core damage probabilities from the internal events PRA, 17 all but eight fire areas were screened as contributing less than 1x10-6 per year to the CDF.

18 Based on the FIVE fire methodology analysis, the unscreened areas were assessed by 19 considering possible targets, fire sources and combustibles, possible fire scenarios (e.g.,

20 target-in-plume), and detection and suppression systems to determine the probability of damage 21 given a fire. Credit was explicitly taken for automatic and manual fire suppression. Calculation 22 of automatic fire suppression unavailability was supported by fault tree modeling. Calculation of 23 manual suppression unavailability was supported by HRA. Consideration of fires on 24 containment performance was also addressed. Final quantification used the Seabrook IPE PRA 25 model to determine plant responses and CDFs. The resulting fire-induced CDF was calculated 26 to be 1.2x10-5 per year. While no physical plant changes were found to be necessary as a 27 result of the IPEEE fire analysis, fire potential plant improvements to improve fire risk were 28 identified. Four of the plant improvements have been implemented. The one improvement not 29 implemented is addressed by a SAMA in the current evaluation and is discussed further in 30 Section F.3.2.

31 NextEra updated the fire PRA subsequent to the IPEEE. The NRC staff asked NextEra to 32 describe the changes to the fire analysis since the IPEEE and to explain the reasons for any 33 significant changes to the fire CDF (NRC, 2011a). In response to the RAI, NextEra explained 34 that the most recent update of the fire PRA was in support of the SSPSA-2004 PRA update, and 35 the fire analysis methodology used is essentially the same, with some variations, as that 36 described previously for the IPEEE fire analysis (NextEra, 2011a). Specific changes made to 37 the Seabrook fire PRA since the IPEEE are listed below:

38

• including current plant data and procedures 39

• performing detailed walkdowns to verify locations of the major fire sources and important 40 targets 41

• updating data to the EPRI fire database that includes fire records through December 42 2000 43

• developing updated severity factors for cabinets, pumps, control room panels, and 44 transients F-14

Appendix F 1

• revisiting the quantitative screening results 2

• using new data on cabinet heat release rates 3

• quantitatively evaluating the total area heat-up rate 4 NextEra also compared the dominant contributors to the fire CDF from the IPEEE PRA model to 5 the dominant contributors from the current fire PRA analysis or SSPSA-2009 model. This 6 comparison is presented in Table F-5. NextEra clarified in a conference call that the fire CDF 7 for the SSPSA-2009 model is somewhat higher than the SSPSA-2006 PRA model fire CDF of 8 1.3x10-6 per year used in the SAMA evaluation (NRC, 2011a). As discussed earlier, NextEra 9 stated that there was no significant shift in the relative importance of initiating events or 10 components between the SSPSA-2006 and SSPSA-2009 PRA models. The dominant fire zone 11 areas in these fire analyses are the control room, essential switchgear rooms, turbine building, 12 and primary auxiliary building.

13 Table F-5. Dominant contributors to fire CDF

% Contribution to fire CDF Fire location IPEEE SSPSA-2009(a)

Control room 34 52 Essential switchgear rooms 18 41 Turbine building 13 5 Primary auxiliary building 26 2 Ocean service water (SW) pumphouse 9 1 Electrical tunnels <1 <1 Total fire CDF (all fire areas) 1.2x10-5 1.7x10-6 (a) -6 The fire CDF for PRA model SSPSA-2009 (1.7x10 per year) is somewhat higher than the fire CDF for PRA model SSPSA-

-6 2006 model (1.3x10 per year) used in the SAMA evaluation. However, the total CDF for the SSPSS-2009 PRA model (1.2 x

-5 -6 10 per year), which includes the increased fire CDF of 1.7 x 10 per year, is lower than the total CDF from the SSPSS-2006

-5 PRA model (1.5 x 10 per year) used in the SAMA analysis. Since the benefits are based on the total potential risk reduction, not just from fire events, the higher, more conservative total value from the SSPSS-2006 PRA model was deemed appropriate for the SAMA analysis, even though it incorporated the somewhat lower total fire CDF. Additional justification for using the SSPSS-2006 value is provided in the text.

14 NextEra stated that the most significant conservatism in the fire analysis is the assumption that 15 small fires, typical of the generic fire events database, are assumed to grow to cause the 16 maximum damage. However, because these fire sequences have such low frequencies and 17 large uncertainties, NextEra claimed the impact of this conservatism on the overall fire CDF is 18 difficult to determine (NextEra, 2011a). NextEra further stated that extensive internal technical 19 reviews of the fire PRA analysis were performed for the original 1983 PRA, when the fire 20 analysis was revised for the IPEEE, and when the fire analysis was revised for the SSPSA-2005 21 PRA model update. No significant comments were documented from these reviews, and no 22 formal peer reviews have been conducted on the fire PRA model (NextEra, 2011a).

23 In a followup RAI, the NRC staff asked NextEra to clarify if fire-induced failures of components 24 and human actions credited with mitigating the initiator were assessed and to describe how hot 25 short probabilities were considered in the fire analysis (NRC, 2011b). In response to the RAI, 26 NextEra clarified that, for fire initiators that are not screened and are evaluated in detail, the F-15

Appendix F 1 probability of fire damage to components due to the fire is included in the analysis and that this 2 probability is dependent upon the presence of combustible material and the success of 3 suppression (NextEra, 2011b). NextEra also stated that the probability of additional failures 4 needed for core damage was also evaluated, including unavailability of redundant systems and 5 components and failure of operator actions, and component failures not impacted by the fire are 6 modeled as random. Regarding the hot short probability question, NextEra explained that a hot 7 short probability of 0.1 was used in the screening evaluation for important valves and 8 components. NextEra also described the results of an evaluation to assess the sensitivity of the 9 SAMA results to using a hot short probability of 0.6. This evaluation determined that the fire 10 event screening evaluation is insensitive to this increase in the potential for hot shorts and that, 11 while the contribution to CDF does increase due to the higher probability, the contribution 12 compared to the CDF contribution of similarly modeled internal events remains relatively low.

13 Specifically, NextEra evaluated 18 fire events and determined that 3 of the events contributed in 14 the range of 10-20 percent of the corresponding internal events CDF, and the remaining 15 fire 15 events contributed less than 10 percent. Based on this result, NextEra determined that the 16 increase in hot short potential does not have a significant effect on the SAMA analysis 17 (NextEra, 2011b).

18 The NRC staff noted that the fire ignition frequencies for a fire in Switchgear Room BLoss of 19 Bus E6 and Switchgear Room ALoss of Bus E5, which were reported to be about 1.0x10-3 per 20 year each, appeared to be low unless the fire only involved the associated buses. The NRC 21 staff asked that NextEra justify these values (NRC, 2010a). NextEra responded that the ignition 22 frequency for Switchgear Room BLoss of Bus E6 includes the cumulative fire ignition 23 frequencies for 21 Bus E6 cabinets and 170 other electrical cabinets. Switchgear Room A 24 Loss of Bus E5 similarly includes the cumulative fire ignition frequencies for 21 Bus E5 cabinets 25 and 86 other electrical cabinets (NextEra, 2011a). NextEra explained that the cited value of 26 1.0x10-3 per year was more than just frequency, i.e., it included not only fire ignition frequency 27 of 4.6x10-5 per year per cabinet but also a severity factor of 0.2 and a manual non-suppression 28 probability of 0.1 for fires in the other electrical cabinets. Therefore, the calculated total fire 29 ignition frequency for each of the two switchgear rooms is the same as that reported in the ER.

30 The NRC staff considers NextEras assumptions reasonable.

31 Considering that the Seabrook fire PRA model is integrated with the internal events PRA, that 32 the fire PRA has been updated to include more current data, and that NextEra has satisfactorily 33 addressed NRC staff RAIs regarding the fire PRA, the NRC staff concludes that the fire PRA 34 model provides an acceptable basis for identifying and evaluating the benefits of SAMAs.

35 The Seabrook IPEEE analysis of high winds, tornadoes, external floods, and other (HFO) 36 external events followed the screening and evaluation approaches specified in Supplement 4 to 37 GL 88-20 (NRC, 1991) and concluded that Seabrook meets the 1975 Standard Review Plan 38 (SRP) criteria (NRC, 1975). Two external event frequencies exceeded the 1.0x10-6 per year 39 screening criterion (NAESC, 1992). One of these events is flooding resulting from a storm 40 surge caused by a hurricane, which is modeled in the PRA and described in the ER 41 (NextEra, 2010) as event EXFLSW in which the SW pumps are flooded. This sequence was 42 reported in the ER to contribute just 2x10-8 per year to the total Seabrook CDF. The second 43 event is an external initiating event involving a truck crash into the SF6 transmission lines. In 44 response to an NRC staff RAI, NextEra explained that this event has been mitigated by the 45 installation of jersey barriers and guard rails that further limit the possibility of a truck crash 46 impacting the transmission lines and that, as a result, this initiating event has been screened 47 from the PRA model (NextEra, 2011a).

F-16

Appendix F 1 While no physical plant changes were found to be necessary as a result of the IPEEE HFO 2 analysis, one plant improvement based on HFO analysis was recommendedmodify several 3 exterior doors so that they will be able to withstand the design pressure differential resulting 4 from high winds. NextEra clarified in response to an NRC staff RAI that this suggested 5 improvement has been implemented (NextEra, 2011a).

6 The NRC staff noted that while the risk of flooding resulting from a storm surge caused by a 7 hurricane is included in the PRA, the impact of hurricane-force winds does not appear to be 8 addressed, and the staff requested that NextEra provide an assessment of the risk of this event 9 on the Seabrook site (NRC, 2010a). In response to the RAI, NextEra explained that the high 10 winds associated with a hurricane that might accompany a storm surge are screened from 11 consideration because the site design basis criteria for high winds and tornadoes meets the 12 1975 SRP criteria (NextEra, 2011a). The NRC staff considered this explanation acceptable.

13 The Seabrook IPEEE submittal also stated that as a result of the Seabrook IPE, cost-benefit 14 analyses are being performed for many potential plant improvements, which may also reduce 15 external event risk because they address functional failures. Five potential plant improvements 16 to improve internal event risk that may also reduce external event risk were identified. Four of 17 the plant improvements have been implemented. The one improvement not implemented is 18 addressed by a SAMA in the current evaluation and is discussed further in Section F.3.2.

19 NextEra estimated the benefits for both internal and external events using the integrated 20 Seabrook PRA model. However, as discussed previously, an NRC staff assessment of the 21 USGS 2008 seismic hazard curves yielded an upper bound seismic CDF for Seabrook of 22 2.2x10-5 per year, which is substantially greater than the 3.1x10-6 per year seismic CDF used in 23 the SAMA evaluation. The NRC staff requested that NextEra provide an assessment of the 24 impact of this higher seismic CDF on the SAMA evaluation (NRC, 2010a; NRC, 2011b). In 25 response to the RAIs, NextEra noted that the NRC staffs estimate of the seismic CDF using the 26 USGS 2008 seismic hazard curves did not include credit for the SEPS DGs installed at 27 Seabrook in 2004, which have a median seismic fragility of 1.23 g (NextEra, 2011b). NextEra 28 stated that the SEPS DGs were modeled in the Seabrook seismic PRA in 2005 and reduced the 29 seismic CDF by approximately 26 percent by avoiding SBO sequences, and a corresponding 30 reduction in the NRC staff estimate of the seismic CDF using the USGS 2008 seismic hazard 31 curves to 1.6x10-5 per year would be expected. NextEra also provided a sensitivity analysis 32 using a multiplier of 2.1 to account for the revised higher seismic CDF. This multiplier is based 33 on an increased seismic CDF of 1.3x10-5 per year (upper bound seismic CDF of 1.6x10-5 per 34 year minus seismic CDF of 3.1x10-6 per year used in the SAMA evaluation) and a total 35 estimated CDF of 1.2x10-5 per year for PRA model SSPSA-2009 (NextEra, 2011b). The NRC 36 staff concurs that a seismic CDF of 1.6x10-5 per year for Seabrook is reasonable and agrees 37 that the licensees use of a multiplier of 2.1 to account for the additional risk from seismic events 38 is reasonable for the purposes of the SAMA evaluation. This is discussed further in 39 Section F.6.2.

40 The NRC staff reviewed the general process used by NextEra to translate the results of the 41 Level 1 PRA into containment releases, as well as the results of the Level 2 analysis, as 42 described in the ER and in response to NRC staff RAIs (NextEra, 2011a). The Level 2 model 43 was significantly revised in the 2005 PRA update (i.e., PRA model SSPSA-2005) from that used 44 in the IPE and reflects the Seabrook plant as designed and operated as of 2006. In response to 45 an NRC staff RAI, NextEra identified the following major changes to the PRA that most 46 impacted the LERF (NextEra, 2011a):

F-17

Appendix F 1

• change in definition of LERF to include steam leak from a SGTR 2

• higher failure likelihood for small containment penetrations in seismic sequences 3

• update to credit manual operator action to close the RCP seal return line MOV 4

• expansion of the LERF model by adding a steam line break to SGTR and consideration 5 of ATWS sequences 6

• updates to the Level 2 analysis to reflect current state of knowledge including SAMGs 7

• revisions to incorporate plant-specific data 8

• update of data distributions 9

• revisions to operator action modeling 10 In response to an NRC staff RAI, NextEra explained that the quantification of the Level 1 and 11 Level 2 models is done using a linked event tree method approach and does not employ plant 12 damage states (NextEra, 2011a). Therefore, all Level 1 sequences are evaluated by the CET, 13 making it unnecessary to summarize and group similar sequences into Level 1 plant damage 14 states before they are input to the CET. The Level 2 model is a single CET and evaluates the 15 phenomenological progression of all the Level 1 sequences including internal, fire, and 16 seismically-initiated events. In response to another NRC staff RAI, NextEra clarified that the 17 CET has 37 branching events, which include 10 hardware-related, 13 human action-related, and 18 13 phenomena-related events, along with a single mapping event (NextEra, 2011a). CET 19 branch point split fraction numerical values are determined based on the type of event. The 20 CET event success criterion is defined, and split fraction logic rules are used to apply the 21 correct event split fraction values during CET quantification. Included in the response to the 22 NRC staff RAI, NextEra provided a description of each of the 37 CET branching events. End 23 states resulting from the combinations of the branches are then assigned to one of 16 release 24 categories based on characteristics that determine the timing and magnitude of the release, 25 whether or not the containment remains intact, and isotopic composition of the released 26 material. In response to another NRC staff RAI, NextEra clarified that the frequency of each 27 release category was obtained by summing the frequency of the individual accident progression 28 CET end states binned into the release category (NextEra, 2011a).

29 The quantified CET sequences binned into the 16 release categories are subsequently grouped 30 into 10 source term categories that provide the input to the Level 3 consequence analysis. In 31 response to an NRC staff RAI, NextEra explained that the 16 release categories were reduced 32 to 10 source term categories by grouping release categories that occur due to different 33 phenomena, but the consequence is essentially the same (e.g., thermally-induced SGTR and 34 pressure-induced SGTR) (NextEra, 2011a). For two of the source term categories, two release 35 categories were binned together to form the combined source term category, and the source 36 term for the release category having the highest release frequency was used as the source term 37 for the combined category. In each of these cases, the release frequency for the selected 38 representative release category is 4-5 orders of magnitude larger than the release frequency for 39 the other release category (e.g., approximately 1x10-7 per year compared to approximately 40 1x10-11 per year). One source term category was created from the binning of three release 41 categories. For this source term category, the release category having the highest 42 consequence source term was selected as the representative release category, i.e., the choice 43 was not based on the relative release frequencies but rather on the most conservative 44 consequence. For the one source term category representing intact containment, two release F-18

Appendix F 1 categories are analyzed separately, and the results are combined for reporting purposes. One 2 release category was eliminated because it was not a credible scenario at Seabrook.

3 Source terms were developed for each of the source term categories. In response to an NRC 4 staff RAI, NextEra clarified that the release fractions and timing for 5 of the 10 source term 5 categories are based on the results of plant-specific calculations using the MAAP Version 4.0.5.

6 The release fractions and timing for the other five source term categories are based on analyses 7 performed for the original 1983 Seabrook PRA (NextEra, 2011a). NextEra generally selected 8 the representative MAAP case based on that which resulted in the most realistic timing and 9 source term release. In response to another NRC staff RAI, NextEra further clarified that the 10 release fractions and timing for the five original release categories are based on WASH-1400 11 (NRC, 1975), the Industry Degraded Core Rule-Making (IDCOR) Program MAAP analysis for 12 the Zion plant, and Seabrook-specific MAAP runs (NextEra, 2011a). The source term 13 categories and their frequencies and release characteristics are presented in Tables F.3.2.1-1 14 and F.3.4.3-2 of Appendix F to the ER (NextEra, 2010) and in response to an NRC staff RAI 15 (NextEra, 2011a).

16 As indicated above, the current Seabrook Level 2 PRA model is an update of that used in the 17 IPE. The IPE did not identify any severe accident vulnerabilities associated with containment 18 performance. Risk-related insights and improvements discussed in the IPE submittal were 19 discussed previously. The NRC staff review of the IPE back-end (i.e., Level 2) model concluded 20 that it appeared to have addressed the severe accident phenomena normally associated with 21 large dry containments, it met the IPE requirements, and there were no obvious or significant 22 problems or errors.

23 The LERF model was included in the 1999 industry peer review discussed previously. Seven of 24 the F&Os from this review addressed the LERF analysis. The applicant provides in the ER the 25 resolution of each of the seven F&Os and states that all have been dispositioned and 26 implemented in the PRA model.

27 The NRC staff noted that the LERF reported for Seabrook is less than one percent of the CDF 28 and asked NextEra to explain this apparently very low LERF (NRC, 2010a). In response to the 29 RAI, NextEra explained that Seabrook has a very large-volume and strong containment building 30 in comparison to most other nuclear power plant containment designs (NextEra, 2011a). As a 31 result of the containment design median failure pressure of 187 pounds per square inch (psia) 32 (dry) and 210 psia (wet), there are no conceivable severe accident progression scenarios that 33 result in catastrophic failure early in the accident sequence. The NRC staff considers NextEras 34 explanation reasonable.

35 The NRC staff requested that NextEra explain how fire-induced ISLOCAs and fire-induced 36 containment impacts are addressed in the fire analysis (NRC, 2010a; NRC, 2011b). In 37 response to the RAIs, NextEra explained that containment performance was evaluated in three 38 areas: (1) containment structure, (2) containment response to a core damage event, and 39 (3) containment isolation failure (NextEra, 2011a). Fires were determined to have no impact on 40 containment structure integrity. Fire-initiated core damage events were determined to have the 41 same impact on containment response as internal-initiated events; thus, they are handled 42 through the CET. The potential for containment isolation failure was assessed by evaluating the 43 potential for fire-induced failure of important isolation valves, as follows:

44

• Because the containment isolation valves (CIVs) are located both inside and outside 45 containment, NextEra concluded that only a fire in the control room or cable spreading F-19

Appendix F 1 room could affect CIVs both inside and outside containment and that, in this event, 2 important CIVs could be controlled locally at the valve or from the remote shutdown 3 panel (RSP). CIVs located outside containment could be controlled both locally at the 4 valve and from the RSP, that CIVs located inside containment could be controlled from 5 the RSP, and that no credit is taken for local control of valves inside containment 6 (NextEra, 2011b).

7

• Because the letdown system has three normally open, air-operated valves (AOVs) in 8 series, NextEra concluded that hot shorting in all three valves is not credible. NextEra 9 clarified that failure to isolate the letdown system for an extended period of time is 10 judged to not be credible for the following reasons (NextEra, 2011b):

11 - There are three AOVs inside containment and one AOV outside containment.

12 - All four AOVs fail to the closed position upon loss of air or control power.

13 - Shorts to ground in the control cables for these AOVs will also result in the AOVs 14 failing to the closed position.

15 - There are two MOVs inside containment that are available to provide isolation.

16

• The potential for fire-induced failures of several other potential isolation pathways was 17 also evaluated (e.g., large residual heat removal (RHR) suction line MOVs, RCP seal 18 return line isolation valves, and containment on-line purge valves) and determined to not 19 be credible.

20 Based on the above, NextEra concluded that the only credible impact of fires on containment 21 performance is to fail a single train of isolation. For isolation failure of one or more valves in a 22 single train, either redundant isolation would be available or the ability to remove power from fail 23 closed valves to provide isolation is available (NextEra, 2011a). NextEra further clarified that, 24 since Seabrook is designed with divisional cable separation, power to the fail closed valves can 25 be removed, if necessary, by removing its divisional power supply, thus ensuring that the valves 26 fail closed and are prevented from being failed opened due to hot shorting (NextEra, 2011b).

27 NextEra further concluded that the frequency of fires that could cause this level of damage is 28 sufficiently low compared to hardware failures that this scenario does not contribute significantly 29 to containment isolation failure and that, as a result, no fire impacts on containment isolation 30 components are included in the PRA (NextEra, 2011a).

31 Based on the NRC staffs review of the Level 2 methodology, the NRC staff concludes that 32 NextEra has adequately addressed NRC staff RAIs, that the LERF model was reviewed in more 33 detail as part of the 1999 WOG certification peer review, and that all F&Os have been resolved.

34 Therefore, the NRC staff concludes that the Level 2 PRA provides an acceptable basis for 35 evaluating the benefits associated with various SAMAs.

36 As indicated in the ER, the reactor core radionuclide inventory used in the consequence 37 analysis corresponds to the end-of-cycle values for Seabrook operating at 3,659 MWt. This 38 bounds the current Seabrook rated power of 3,648 MWt. The core radionuclide inventory is 39 provided in Table F.3.4.3-1 of Appendix F of the ER (NextEra, 2010). In response to an NRC 40 staff RAI, NextEra clarified that a Seabrook-specific core inventory was calculated using 41 ORIGEN2.1 except for Cobalt-58 and Cobalt-60 (NextEra, 2011a). NextEra noted that the 42 ORIGEN calculations did not provide isotopic inventories for Cobalt-58 and Cobalt-60.

43 Therefore, these isotope inventories were estimated using the MACCS2 sample problem 44 inventory corrected by the ratio of Seabrook's power level to the MACCS2 sample problem A 45 power level (i.e., 3,659 MWt/3,412 MWt). Based on this clarification, the NRC staff concludes F-20

Appendix F 1 that the reactor core radionuclide inventory assumptions for estimating consequences are 2 reasonable and acceptable for purposes of the SAMA evaluation.

3 The NRC staff reviewed the process used by NextEra to extend the containment performance 4 (Level 2) portion of the PRA to an assessment of offsite consequences (essentially a Level 3 5 PRA). This included consideration of the source terms used to characterize fission product 6 releases for the applicable containment release categories and the major input assumptions 7 used in the offsite consequence analyses. Version 1.13.1 of the MACCS2 code was used to 8 estimate offsite consequences (NRC, 1998). Plant-specific input to the code includes the 9 source terms for each release category and the reactor core radionuclide inventory (both 10 discussed above), site-specific meteorological data, projected population distribution within an 11 80-km (50-mi) radius for the year 2050, emergency evacuation planning, and economic 12 parameters including agricultural production. This information is provided in Section F3.4 of 13 Attachment F to the ER (NextEra, 2010).

14 All releases were modeled as occurring at the top height of the containment building. Sensitivity 15 cases were run assuming ground level release, as well as releases at 25 percent, 50 percent, 16 and 75 percent of the containment building height. In response to an NRC staff RAI, NextEra 17 reported that decreasing the release height from the top of the reactor building to ground level 18 decreased the population dose risk and offsite economic cost risk by up to 3 percent and 19 4 percent, respectively (NextEra, 2011a). The thermal content of each of the releases was 20 assumed to be the same as ambient (that is a non-buoyant plume). A sensitivity analysis was 21 performed assuming a 1 MW and 10 MW heat release plume. In response to an NRC staff RAI, 22 NextEra reported that increasing the release heat decreased the population dose risk by 23 2 percent and 12 percent, and the offsite economic cost risk decreased by 1 percent and 24 9 percent for the 1 MW and 10 MW heat release, respectively (NextEra, 2011a). Wake effects 25 for the containment building were included in the model. A sensitivity analysis was performed 26 assuming the wake size was one-half and double the baseline wake size. In response to an 27 NRC staff RAI, NextEra reported that decreasing the wake size by one-half decreased the 28 population dose risk by 1 percent and did not change the offsite economic cost risk, while 29 doubling the wake size increased both the population dose risk and offsite economic cost risk by 30 1 percent (NextEra, 2011a). The NRC staff notes that these results are consistent with previous 31 SAMA analyses that have shown only minor sensitivities to release height, buoyancy, and 32 building wake effects. Based on the information provided, the staff concludes that the release 33 parameters used are acceptable for the purposes of the SAMA evaluation.

34 NextEra used site-specific meteorological data for the year 2005 as input to the MACCS2 code.

35 The development of the meteorological data is discussed in Section F.3.4.5 of the ER 36 (NextEra, 2010). Data from 2004-2008 were also considered, but the 2005 data were chosen 37 because the results of a MACCS2 sensitivity analysis indicated that the 2005 data produced 38 more conservative results (i.e., the 2005 data set was found to result in the largest population 39 dose risk and offsite economic cost risk). In response to an NRC staff RAI, NextEra reported 40 that the results of the meteorological data sensitivity analysis, which was performed for each of 41 the years 2004-2008, showed a decrease in population dose risk in the range of 5-13 percent 42 and a range of 3-12 percent decrease in offsite economic cost risk (NextEra, 2011a). Missing 43 data were estimated using data substitution methods. These methods include substitution of 44 missing data with corresponding data from another level on the meteorological tower, 45 interpolation between data from the same level, or data from the same hour and a nearby day of 46 a previous year. Hourly stability was classified according to the system used by the NRC 47 (NRC, 1983). The baseline analysis assumes perpetual rainfall in the 40-50 mi segment 48 surrounding the site. A sensitivity analysis was performed assuming measured rainfall rather F-21

Appendix F 1 than perpetual rainfall in the 40-50 mi spatial segment. This resulted in a decrease in 2 population dose risk of 14 percent and a decrease in offsite economic cost risk of 17 percent.

3 The NRC staff notes that these results are consistent with previous SAMA analyses that have 4 shown little sensitivity to year-to-year differences in meteorological data. Based on the 5 information provided, the NRC staff concludes that the use of the 2005 meteorological data in 6 the SAMA analysis is reasonable.

7 The population distribution the licensee used as input to the MACCS2 analysis was estimated 8 for the year 2050 using year 2000 census data as accessed by SECPOP2000 (NRC, 2003).

9 The baseline population was determined for each of 160 sectors, consisting of the 16 directions 10 for each of 10 concentric distance rings with outer radii at 1, 2, 3, 4, 5, 10, 20, 30, 40, and 50 mi 11 surrounding the site. County population growth estimates were applied to year 2000 census 12 data to develop year 2050 population distribution. The distribution of the population is given for 13 the 10-mi radius from Seabrook and for the 50-mi radius from Seabrook in the ER 14 (NextEra, 2010). In response to an NRC staff RAI, NextEra clarified that the year 2000 15 population was exponentially extrapolated to year 2050. The NRC staff noted that the total 16 population of 4,157,215 identified in Section 2.6.1 of the ER was different than the 4,232,394 17 reported in ER Table F.3.4.1 (NRC, 2010a). In response to the NRC staff RAI, this difference 18 was attributed to the following factors (NextEra, 2011a):

19

• choice of distribution centroids between the two references 20

• including transient population in the population extrapolation for ER Table F.3.4.1-1 but 21 not in ER Section 2.6.1 22

• where the 50-mile radius bisects the census block groups, the population fraction is 23 assumed equal to the land area fraction 24 The NRC staff also requested clarification of why some sectors showed zero or (small) negative 25 population growth (NRC, 2010a). NextEra clarified that this was attributed to the geographic 26 information system (GIS) land layers not being detailed enough to account for the existence of 27 some small islands, and the GIS water sectors were projected as zero populations 28 (NRC, 2011a). Also, the direction distribution used in the 2050 projection was slightly offset 29 from the existing population, resulting in some sectors being considered all water, and thus zero 30 population. In fact, a portion of those sectors include the coastline and, therefore, have a 31 population. The population projections were refined to account for the above and to include the 32 most recent county population growth rates (the sensitivity case above). A sensitivity analysis 33 was performed using the refined population projections and the population distribution centroid 34 for ER Table F.3.4.1-1. This resulted in an overall population decrease of about 4 percent, 35 resulting in a corresponding decrease in population dose risk and economic cost risk of 36 5 percent and 6 percent, respectively. The NRC staff considers the methods and assumptions 37 for estimating population reasonable and acceptable for purposes of the SAMA evaluation.

38 The emergency evacuation model was modeled as a single evacuation zone extending out 39 16 km (10 mi) from the plant. NextEra assumed that 95 percent of the population would 40 evacuate. This assumption is conservative relative to the NUREG-1150 study (NRC, 1990),

41 which assumed evacuation of 99.5 percent of the population within the emergency planning 42 zone (EPZ). The evacuated population was assumed to move at an average speed of 43 approximately 0.4 meters per second (0.9 miles per hour (mph)) with a delayed start time of 44 120 minutes after declaration of a general emergency. The evacuation speed was derived from 45 the projected time to evacuate the entire EPZ under adverse weather conditions during the year 46 2000 (NextEra, 2010) and then adjusted by the ratio of the year 2000 EPZ population to the F-22

Appendix F 1 projected year 2050 EPZ population. NextEra performed sensitivity analyses in which the 2 evacuation speed, the delayed start time or preparation time for evacuation of the EPZ, and the 3 emergency declaration time were each individually decreased by 50 percent and also doubled 4 relative to the base case. In response to an NRC staff RAI, NextEra reported that the decrease 5 in evacuation speed increased the population dose risk by 3 percent, and the increase in 6 evacuation speed decreased the population dose risk by 4 percent. Additionally, the decrease 7 in delay time decreased the population dose risk by 9 percent, the increase in delay time 8 decreased the population dose risk by 2 percent, the decrease in emergency declaration time 9 decreased the population dose risk by 6 percent, and the increase in emergency declaration 10 time decreased the population dose risk by 3 percent (NextEra, 2011a). For all three 11 parameters, both the increase and decrease in the base values resulted in no change to the 12 offsite economic cost risk. In the ER, NextEra explained that an increase in delay time or 13 emergency declaration time could decrease population dose risk if the evacuation and plume 14 release are simultaneous. NextEra also performed a sensitivity analysis assuming that the 15 population does not evacuate for a severe accident resulting in a small, early containment 16 penetration failure with no source term scrubbing, representative of a seismically-induced 17 severe accident event. In response to an NRC staff RAI, NextEra reported that this resulted in 18 increasing the population dose risk by 4 percent with no change in offsite economic cost risk.

19 The NRC staff concludes that the evacuation assumptions and analysis are reasonable and 20 acceptable for the purposes of the SAMA evaluation.

21 In an NRC staff RAI, NextEra clarified that sea-breeze circulation was included in the SAMA 22 evaluation only to the extent that this is included in the onsite meteorological data 23 (NextEra, 2011a). NextEra further explained that there are two major mechanisms associated 24 with sea-breezes, a mixing front and thermal internal boundary layer (TIBL). A mixing front 25 results in increased plume mixing and dispersion, resulting in a potential decrease in population 26 dose. This was conservatively ignored in the SAMA evaluation. However, TIBL could decrease 27 dispersion and increase population dose. Given this, NextEra performed a sensitivity study 28 assuming 25 percent of the year with TIBL formation (data for year 2005 identified a TIBL was 29 present 7 percent of the year). The increase in TIBL formation increased the population dose 30 risk and offsite economic cost risk by 4 percent and 7 percent, respectively. In addition, 31 sensitivity of the TIBL lid height was investigated by changing the lid height from 110 meters (m) 32 to 100 m. The decrease in TIBL lid height resulted in an increase in population dose risk and 33 offsite economic cost of less than 1 percent each. The NRC staff concludes that sea-breeze 34 affects have a minor impact on the SAMA analysis results.

35 Much of the site-specific economic and agricultural data were provided from SECPOP2000 36 (NRC, 2003) by specifying the data for each of the 13 counties surrounding Seabrook, to a 37 distance of 80 km (50 mi). SECPOP2000 uses county economic and agriculture data from the 38 2000 National Census of Agriculture. This included the fraction of land devoted to farming, 39 annual farm sales, the fraction of farm sales resulting from dairy production, and the value of 40 non-farm land. In response to an NRC staff RAI, NextEra identified that the recent, three known 41 errors in SECPOP2000 were corrected for the SAMA evaluation (NextEra, 2011a).

42 The NRC staff concludes that the methodology used by NextEra to estimate the offsite 43 consequences for Seabrook provides an acceptable basis from which to proceed with an 44 assessment of risk reduction potential for candidate SAMAs. Accordingly, the NRC staff based 45 its assessment of offsite risk on the CDF and offsite doses reported by NextEra.

F-23

Appendix F 1 F.3 Potential Plant Improvements 2 The process for identifying potential plant improvements, an evaluation of that process, and the 3 improvements evaluated in detail by NextEra are discussed in this section.

4 F.3.1 Process for Identifying Potential Plant Improvements 5 NextEras process for identifying potential plant improvements (SAMAs) consisted of the 6 following elements:

7

• review of the most significant basic events from the 2006 plant-specific PRA, which was 8 the most current PRA model at the time the SAMA evaluation 9

• review of potential plant improvements identified in the Seabrook IPE and IPEEE 10

• review of other industry documentation discussing potential plant improvements 11

• insights from Seabrook personnel 12 Based on this process, an initial set of 191 candidate SAMAs, referred to as Phase I SAMAs, 13 was identified. In Phase I of the evaluation, NextEra performed a qualitative screening of the 14 initial list of SAMAs and eliminated SAMAs from further consideration using the following 15 criteria:

16

• The SAMA is not applicable to Seabrook due to design differences (19 SAMAs 17 screened).

18

• The SAMA has already been implemented at Seabrook or Seabrook meets the intent of 19 the SAMA (87 SAMAs screened).

20

• The SAMA is similar to another SAMA under consideration (11 SAMAs screened).

21

• The SAMA has estimated implementation costs that would exceed the dollar value 22 associated with eliminating all severe accident risk at Seabrook (no SAMA screened).

23

• The SAMA was determined to provide very low benefit (no SAMA screened).

24 Based on this screening, 117 SAMAs were eliminated, leaving 74 for further evaluation. The 25 remaining SAMAs, referred to as Phase II SAMAs, are listed in Table F.7-1 of the ER 26 (NextEra, 2010). In Phase II, NextEra performed an additional qualitative screening of the 27 Phase II SAMAs and eliminated 13 SAMAs that had estimated implementation costs that would 28 exceed the dollar value associated with eliminating all severe accident risk at Seabrook. Also in 29 Phase II, a detailed evaluation was performed for each of the remaining 61 SAMA candidates, 30 as discussed in Sections F.4 and F.6 below. The estimated benefits for these SAMAs included 31 the risk reduction from both internal and external events.

32 As previously discussed, NextEra accounted for the potential risk reduction benefits associated 33 with each SAMA by quantifying the benefits using the integrated internal and external events 34 PRA model. In response to NRC staff RAIs, NextEra performed a sensitivity analysis to account 35 for the potential additional risk reduction benefits associated with the additional risk from seismic 36 events. NextEra multiplied the estimated benefits for internal and external events by a factor of 37 2.6 for those Phase II SAMAs that were qualitatively screened on high implementation costs 38 and by a factor of 2.1 for all other Phase II SAMAs for which a detailed evaluation was 39 performed (NextEra, 2011a; NextEra, 2011b).

F-24

Appendix F 1 F.3.2 Review of NextEras Process 2 NextEras efforts to identify potential SAMAs focused primarily on areas associated with internal 3 initiating events but also included explicit consideration of potential SAMAs for fire and seismic 4 events. The initial list of SAMAs generally addressed the accident sequences considered to be 5 important to CDF from functional, initiating event, and risk reduction worth (RRW) perspectives 6 at Seabrook.

7 NextEras SAMA identification process began with a review of the list of potential PWR 8 enhancements in Table 14 of NEI 05-01 (NEI, 2005). As a result of this review, 153 SAMAs 9 were identified. In response to an NRC staff RAI, NextEra clarified that as a result of a general 10 solicitation of Seabrook staff for possible SAMA candidates and a review of both industry and 11 plant-specific SAMA candidates by an expert panel, 13 additional SAMAs were identified 12 (NextEra, 2011a).

13 NextEra provided tabular listings of both the Level 1 and LERF PRA internal, fire, and seismic 14 basic events sorted according to their RRW (NextEra, 2010). SAMAs impacting these basic 15 events would have the greatest potential for reducing risk. NextEra used an RRW cutoff of 16 1.005, which corresponds to about a 0.5 percent decrease in CDF given 100-percent reliability 17 of the equipment or human actions associated with the SAMA. In response to an NRC staff 18 RAI, NextEra determined that this equates to a benefit of approximately $2,500 based on 19 eliminating the entire risk from basic event HH.RDGL2Q.FL, operator fails to locally reset 20 breakers and start pumps, which has an RRW of 1.0057 (NextEra, 2011a). Or, it equates to 21 approximately $5,300 after the benefits have been multiplied by a factor of 2.1 to account for the 22 additional risk from seismic events (NextEra, 2011b). NextEra correlated all 70 Level 1 and 23 48 LERF basic events in the listings with SAMA categories evaluated in Phase I or Phase II and 24 showed that all of the basic events are either addressed by a SAMA category or a specific 25 SAMA, or were operator actions for which no plant-specific procedure improvements were 26 identified.

27 The NRC staff asked NextEra to clarify how the RRW importance analysis was used to develop 28 plant-specific SAMAs (NRC, 2010a). NextEra responded that the SAMA identification process 29 specifically included a review of the most risk-significant basic events, and all systems and 30 components having an RRW greater than 1.005 were reviewed to ensure that each was 31 covered by an existing generic or plant-specific SAMA candidate based on a functional category 32 such as feedwater and condensate (NextEra, 2011a).

33 In a separate RAI, the NRC staff noted that it was not always clear which SAMA in a functional 34 category addressed the specific basic events. The staff asked NextEra to identify the specific 35 SAMAs that address each basic event in the importance list (NRC, 2010a). In response to the 36 RAI, NextEra provided a listing of the top 15 Level 1 basic events, having an RRW down to 37 1.0223, and correlated at least 1 SAMA to each basic event (NextEra, 2011a). An RRW of 38 1.0223 was determined to equate to a benefit of approximately $32,000 based on eliminating 39 the entire risk from basic event HH.ORWMZ1.FA, operator minimizes emergency core cooling 40 system (ECCS) flow with recirculation failure. Or, it equates to a benefit of approximately 41 $67,000 after the benefits have been multiplied by a factor of 2.1 by the NRC staff to account for 42 the additional risk from seismic events, which is less than the minimum implementation cost of 43 $100,000 associated with a hardware change. As a result of this review the following, new 44 SAMAs were identified and evaluated and are discussed further in Section F.6.2:

45

• SAMA improve Bus E6 reliability, eliminate/reduce potential for bus fault F-25

Appendix F 1

• SAMA improve Bus E5 reliability, eliminate/reduce potential for bus fault 2

• SAMA improve Supplemental Electrical Power System (SEPS) diesel generator (DG) 3 reliability, eliminate potential for SEPS failure 4

• SAMA improve reliability of power operated relief valve (PORV) reseat function, 5 eliminate PORV reseat failures 6 NextEra states in the ER that no SAMAs were identified to address the operator actions in the 7 Level 1 and LERF basic events importance lists because the current plant procedures and 8 training meet current industry standards, and no plant-specific procedure improvements were 9 identified that would affect the results of the HEP calculations. The NRC staff asked NextEra to 10 consider the feasibility of non-procedural and training SAMAs for the human error basic events 11 (NRC, 2011a). In response to this RAI and the previously discussed RAI, NextEra identified 12 and evaluated the following SAMAs to automate the 3 operator actions included in the top 15 13 Level 1 basic events and to automate or install additional alarm indication for the operator action 14 having the highest LERF-related RRW (NextEra, 2011a):

15

• SAMA provide auto-start and load for SEPS DG 16

• SAMA provide hardware change for automatic ECCS flow control 17 For each of these SAMAs, NextEra showed that the benefit from eliminating the risk of each of 18 these basic events is less than the minimum implementation cost of $100,000 associated with a 19 hardware change. This is discussed further in Section F.6.2. NextEra concluded that lower 20 risk-significant operator actions on the Level 1 and 2 importance lists would correspondingly not 21 be cost-beneficial since their potential benefit would be less than their minimum cost, as 22 represented by a hardware change. Based on this result, no SAMAs were identified for 23 operator actions having a lower RRW. Based on NextEras statement that procedure and 24 training improvements have been considered but that no improvements were identified that 25 would reduce plant risk, the NRC staff concludes that it is unlikely that additional cost-beneficial 26 SAMAs would be found from a further review of operator actions having lower RRWs.

27 The NRC staff asked NextEra to provide a listing of the Level 2 non-LERF basic events that 28 contribute 90 percent of the population dose-risk and to review these basic events for potential 29 SAMAs (NRC, 2010a). In response to the RAI, NextEra provided a listing of the top 15 basic 30 events each for release categories SE3, LL3, LEI, SEI, and LL4, which contribute approximately 31 91 percent of the population dose-risk, and correlated at least one SAMA to each basic event 32 (NextEra, 2011a). The top 15 basic events correspond to a review of basic events down to 33 release category-specific RRWs of 1.007 for SE3, 1.031 for LL3, 1.033 for LEI, 1.019 for SEI, 34 and 1.030 for LL4. As a result of this review, the following additional SAMAs were identified and 35 evaluated and are discussed further in Section F.6.2:

36

• SAMA hardware or procedural change to eliminate or reduce likelihood of small 37 pre-existing unidentified leakage 38

• SAMA hardware change for auto closure of SEPS breaker to eliminate operator action 39

• SAMA hardware change to eliminate motor operated valve (MOV) AC power 40 dependencies 41

• SAMA provide a hardware modification (additional signals or remote capability) to 42 automatically close containment isolation valve V-167 43

• SAMA provide hardware modification to improve lube oil pump reliability F-26

Appendix F 1

• SAMA improve primary closed cooling (PCC) temperature element (TE) reliability, 2 eliminate potential for temperature element failure 3

• SAMA provide a hardware modification for auto-control, eliminate operator action to 4 align sump after core melt 5

• SAMA improve PCC heat exchanger reliability, eliminate potential for heat exchanger 6 leakage 7

• SAMA improve service water secondary isolation MOV SWV-5 reliability, eliminate 8 valve failure 9

• SAMA hardware for automatic feed flow, eliminate potential for operator failure to feed 10 steam generator 11

• SAMA improve reliability of startup feed pump (SUFP), eliminate potential for SUFP 12 failure 13

• SAMA hardware change to eliminate or reduce mechanical failures of motor-driven 14 (MD) EFW pump 15

• SAMA implement hardware change to improve reliability of SGTR control, eliminate or 16 reduce operator failure to terminate safety injection 17

• SAMA provide automatic control, eliminate or reduce operator failure to terminate safety 18 injection 19

• SAMA hardware change to provide auto-makeup to reactor water storage tank (RWST),

20 eliminate operator action 21

• SAMA hardware change for automatic control or eliminate operator action to maintain 22 stable conditions 23

• SAMA improve hardware/procedures to reduce or eliminate basic event exposure 24 probability, improve control rod insertion (CRI) availability 25

• SAMA provide auto-start of SUFP, eliminate potential for operator failure to start SUFP 26

• SAMA implement hardware change to improve reliability of SGTR control, eliminate 27 operator action to depressurize 28

• SAMA hardware change to eliminate operator action to depressurize in SGTR events 29

• SAMA hardware change for automatic control or eliminate operator action to cooldown 30 [reactor cooling system] RCS in SGTR events 31

• SAMA implement hardware change to improve reliability, eliminate operator action to 32 cooldown/depressurize 33

• SAMA hardware change for automatic control or eliminate operator actions to cooldown 34 the RCS for residual heat removal (RHR) shutdown cooling in SGTR events 35

• SAMA hardware change to improve valve reliability, eliminate Containment Building 36 spray (CBS) discharge MOV failures 37

• SAMA hardware change for automatic venting control, eliminate need to perform late 38 containment venting 39

• SAMA hardware change for automatic initiation of containment injection gravity drain, 40 eliminate operator action F-27

Appendix F 1 The NRC staff estimated that a risk reduction of 3.3 percent, corresponding to the highest RRW 2 review level of the five release categories reviewed, equates to a maximum benefit of 3 approximately $27,000. Or, it equates to approximately $57,000 after the benefits have been 4 multiplied by a factor of 2.1 by the NRC staff to account for the additional risk from seismic 5 events, which is less than the minimum implementation cost of $100,000 associated with a 6 hardware change. Based on this, and NextEras statement discussed previously that procedure 7 and training improvements have been considered but that no improvements were identified that 8 would reduce plant risk, the NRC staff concludes that it is unlikely that additional cost-beneficial 9 SAMAs would be found from a further review of release category basic events having lower 10 RRWs.

11 In response to this same RAI, NextEra stated that all of the top ranked basic events related to 12 LERF, as identified in Table F.3.2.1-2 of the ER, were addressed by the Level 1 and Level 2 13 basic events reviews described above. The NRC staff reviewed the LERF basic events and 14 determined that all but 17 basic events were addressed by at least 1 SAMA. All but one of 15 these events had an RRW of less than 1.031, which was estimated by the NRC staff to have a 16 maximum benefit less than the minimum implementation cost of $100,000 associated with a 17 hardware change. Basic event FWP161.FS, startup pre-lube oil pump FY-P-161 fails to start 18 on demand, has a LERF RRW of 1.0886. The NRC staff asked NextEra to provide an 19 evaluation of a SAMA to address this basic event (NRC, 2011b). In response to the followup 20 RAI, NextEra identified and evaluated SAMA improve the reliability of the pre-lube pump via 21 installation of a redundant pump to address basic event FWP161.FS (NextEra, 2011b). This is 22 discussed further in Section F.6.2. Based on the results of the NRC staffs review of the LERF 23 basic events, NextEras evaluation of a SAMA for basic event FWP161.FS, and NextEras 24 statement discussed previously that procedure and training improvements have been 25 considered but that no improvements were identified that would reduce plant risk, the NRC staff 26 concludes that it is unlikely that additional cost-beneficial SAMAs would be found from a further 27 review of release category basic events having lower RRWs.

28 The NRC staff noted that neither the Level 1 nor LERF importance analyses specifically 29 identified any initiating events and asked NextEra to clarify why this is the case (NRC, 2010a).

30 In response to the RAI, NextEra stated that the importance analyses did include consideration 31 of initiating events because failure of the support system relied upon to mitigate the initiating 32 event is included in the importance analysis (NextEra, 2011a). NextEra further noted that 33 several SAMA candidates were evaluated assuming complete elimination of certain initiating 34 events. In response to a followup RAI, NextEra identified the SAMA candidates that address 35 each of the top 10 most risk-significant initiating events, which correspond to all initiating events 36 that contribute at least 2.6 percent to the total CDF (NextEra, 2011b). As a result of this review, 37 the following additional SAMAs were identified and evaluated and are discussed further in 38 Section F.6.2:

39

• SAMA improve overall Seabrook reliability; reduce potential for plant trip initiating event 40 frequency or reliability of mitigation systems to plant trip 41

• SAMA reduce/elimination impact of 0.7 g seismic event 42

• SAMA protect relay room from potential impact from high energy line break (HELB) 43

• SAMA improve/reduce the core damage frequency contribution of Switchgear Room B 44 fire events 45 The NRC staff estimated that a risk reduction of 2.6 percent, corresponding to the least risk 46 significant of the initiating events reviewed by NextEra, equates to a maximum benefit of F-28

Appendix F 1 approximately $21,000. Or, it equates to approximately $44,000 after the benefits have been 2 multiplied by a factor of 2.1 by the NRC staff to account for the additional risk from seismic 3 events, which is less than the minimum implementation cost of $100,000 associated with a 4 hardware change. Based on this, and NextEras statement discussed previously that procedure 5 and training improvements have been considered but that no improvements were identified that 6 would reduce plant risk, the NRC staff concludes that it is unlikely that additional cost-beneficial 7 SAMAs would be found from a further review of initiating events having lower contribution to 8 CDF.

9 In response to an NRC staff RAI, NextEra reviewed the cost-beneficial SAMAs from prior SAMA 10 analyses for five Westinghouse four-loop PWR sites (NextEra, 2011a). NextEras review 11 determined that all but two of these cost-beneficial SAMAs were already represented by a 12 SAMA, have intent that was already met at Seabrook, have low potential for risk reduction at 13 Seabrook (e.g., do not address risk-important basic events), or were not applicable to Seabrook.

14 Two SAMAs were identified and evaluated further as a result of this review and are further 15 discussed in Section F.6.2. The two SAMAs are procedure change to ensure that the RCS 16 cold leg water seals are not cleared and installation of redundant parallel service water valves 17 to the emergency diesel generators (EDGs).

18 The NRC staff noted that both SAMA 173, identified from the IPEEE review, and SAMA 185 are 19 described as improve procedural guidance for directing depressurization of RCS, and 20 requested NextEra to clarify the difference between these two SAMAs (NRC, 2010a). In 21 response to the RAI, NextEra clarified that SAMA 173 was to improve procedural guidance 22 directing operators to depressurize the RCS before core damage, while SAMA 185 was to 23 improve procedural guidance directing operators to depressurize the RCS after core damage.

24 The NRC staff considers NextEras clarification reasonable.

25 Although the IPE did not identify any fundamental vulnerabilities or weaknesses related to 26 internal events, 14 potential plant improvements were identified. NextEra reviewed these 27 potential improvements for consideration as plant-specific candidate SAMAs. In response to an 28 NRC staff RAI, NextEra clarified that the following 13 SAMAs were identified from the review of 29 the potential plant improvements identified in the IPE (NextEra, 2011a):

30

• Phase II SAMA 167, install independent seal injection pump (low volume pump) with 31 automatic start 32

• Phase II SAMA 168, install independent seal injection pump (low volume pump) with 33 manual start 34

• Phase II SAMA 169, install independent charging pump (low volume pump) with manual 35 start 36

• Phase I SAMA 155, install alternate emergency AC power source (e.g., swing diesel) 37

• Phase II SAMA 156, install alternate off-site power source that bypasses switchyard, for 38 example, use campus power source to energize Bus E5 or E6 39

• Phase II SAMA 174, provide alternate scram button to remove power from MG sets to 40 CR drives 41

• Phase II SAMA 157, provide independent AC source for battery chargers, for example, 42 provide portable generator to charge station battery F-29

Appendix F 1

• Phase I SAMA 158, provide enhanced procedural direction for cross-tie of batteries 2 within each train 3

• Phase II SAMA 159, install additional batteries 4

• Phase II SAMA 184, control/reduce time that the containment purge valves are in open 5 position 6

• Phase I SAMA 185, improve procedural guidance to directing depressurization of RCS 7

• Phase II SAMA 186, install containment leakage monitoring system 8

• Phase II SAMA 187, install RHR isolation valve leakage monitoring system 9 In addition, the improvement identified in the IPE for alternate, independent EFW pump (e.g.,

10 diesel firewater pump hard piped to discharge of startup feed pump), is already addressed by 11 Phase I SAMA 29, provide capability for alternate injection via diesel-driven fire pump, and 12 Phase II SAMA 163, install third EFW pump (steam-driven). Phase I SAMA 29 and Phase II 13 SAMA 163 were previously identified from the review of the list of potential PWR enhancements 14 in Table 14 of NEI 05-01 (NEI, 2005). Phase I SAMAs 29, 155, 158, and 185 were screened in 15 the Phase I evaluation as having already been implemented.

16 Based on this information, the NRC staff concludes that the set of SAMAs evaluated in the ER, 17 together with those identified in response to NRC staff RAIs, addresses the major contributors 18 to internal event CDF.

19 As described previously, NextEras importance analysis considered both fire and seismic basic 20 events from the internal and external event integrated Level 1 and Level 2 PRA model. The 21 NRC staff noted that since the importance analyses did not separately consider the importance 22 of internal, fire, and seismic events, SAMAs identified to address the important basic events 23 may not address the more important initiator (e.g., fire) and requested NextEra to explain how 24 the identified SAMAs address this issue (NRC, 2010a). In response to the RAI, NextEra 25 explained that the importance analysis considers the contribution from all hazards, and the 26 contribution from the individual hazards will be a subset of the total risk contribution.

27 Additionally, based on evaluations provided in response to the NRC staff RAIs discussed above 28 in which SAMAs were identified to address each of the important Level 1 and 2 basic events, 29 hardware changes to address the individual hazard contributors would not, in NextEras 30 judgement, be cost-beneficial based on a conservative minimum cost for a hardware change of 31 $100,000 (NextEra, 2011a). Based on the NRC staff conclusions above regarding NextEras 32 systematic process for identifying SAMAs for each important Level 1 and 2 basic event and 33 NextEras statement that procedure/training improvements have been considered but that no 34 improvements were identified that would reduce plant risk, the NRC staff agrees that it is 35 unlikely that additional cost-beneficial SAMAs would be found from a further review of basic 36 events.

37 Although the IPEEE did not identify any fundamental vulnerabilities or weaknesses related to 38 external events, two potential plant improvements were identified to improve seismic CDF, and 39 five potential plant improvements were identified to improve fire CDF. Additionally, five potential 40 plant improvements were identified that were being evaluated to improve internal event risk but 41 which may also reduce external event risk because they address functional failures. In 42 response to an NRC staff RAI, NextEra clarified that the following 12 SAMAs were identified 43 from the review of the potential plant improvements identified in the IPEEE (NextEra, 2011a):

44

• SAMAs to improve seismic CDF F-30

Appendix F 1 - Phase II SAMA 181, improve relay chatter fragility 2 - Phase II SAMA 182, improve seismic capacity of EDGs and steam-driven EFW 3 pump 4

• SAMAs to improve fire CDF 5 - Phase II SAMA 175, install fire detection in turbine building relay room 6 - Phase I SAMA 176, install additional suppression at west wall of turbine 7 building 8 - Phase I SAMA 177, improve fire response procedure to indicate that [primary 9 component cooling water] PCCW can be impacted by [primary auxiliary building]

10 PAB fire event 11 - Phase I SAMA 178, improve the response procedure to indicate important fire 12 areas including control room, PCCW pump area, and cable spreading room 13 - Phase I SAMA 180, modify SW pump house roof to allow scuppers to function 14 properly 15

• Other SAMAs identified from the IPEEE review 16 - Phase I SAMA 160, enhancements to address loss of SF6-type sequences 17 - Phase I SAMA 171, install high temperature O-rings in RCPs 18 - Phase I SAMA 173, improve procedural guidance for directing depressurization 19 of RCS 20 - Phase II SAMA 179, fire-induced LOCA response procedure from Alternate 21 Shutdown Panel 22 - Phase I SAMA 183, Turbine Building internal flooding improvements 23 Phase I SAMAs 160, 171, 173, 176, 177, 178, 180, and 183 were screened in the Phase I 24 evaluation as having already been implemented.

25 The NRC staff questioned whether SAMA 162, increase the capacity margin of the condensate 26 storage tank (CST) addressed basic event COTK25.RT, condensate storage tank CO-TK-25 27 ruptures/excessive leakage (NRC, 2010a). In response to the RAI, NextEra explained that the 28 CST has a median seismic fragility of 1.65 g and a HCLPF of 0.65, without crediting the 29 concrete shield structure surrounding the CST (NextEra, 2011a). Therefore, NextEra identified 30 and evaluated a SAMA to make seismic upgrades to the CST. This is discussed further in 31 Section F.6.2.

32 The NRC staff asked NextEra to clarify how additional fire barriers for fire areas were 33 considered since SAMA 143, upgrade fire compartment barriers, was screened in the Phase I 34 evaluation based on the Seabrook plant design including 3-hour rated fire barriers 35 (NRC, 2010a). NextEra responded with a review of the fire risk by plant location and explained 36 that it is not physically possible to install additional fire barriers in the control room, which 37 contribute 52 percent of the fire CDF, and that additional fire barriers in the essential switchgear 38 rooms, which contribute 41 percent of the fire CDF, would have no impact on the fire risk since 39 these rooms are already separated (NextEra, 2011a). Other lower risk fire areas were also 40 similarly evaluated with similar conclusions. In a response to a followup NRC staff RAI, NextEra 41 further clarified that additional fire barriers were not considered for the essential switchgear 42 rooms because a review of fire scenarios in these rooms did not identify impacts to any F-31

Appendix F 1 redundant safety train cables (NextEra, 2011b). The NRC staff concludes that the applicants 2 rationale for eliminating fire barrier enhancements from further consideration is reasonable.

3 Based on the licensees IPEEE, the review of the results of the Seabrook PRA, which includes 4 seismic and fire events, and the expected cost associated with further risk analysis and potential 5 plant modifications, the NRC staff concludes that the opportunity for seismic and fire-related 6 SAMAs has been adequately explored and that it is unlikely that there are any additional 7 cost-beneficial seismic or fire-related SAMA candidates.

8 As stated earlier, other external hazards (i.e., high winds, external floods, transportation and 9 nearby facility accidents, and chemical releases) are below the IPEEE threshold screening 10 frequency, or met the 1975 SRP design criteria, and are not expected to represent opportunities 11 for cost-beneficial SAMA candidates. Nevertheless, NextEra reviewed the IPEEE results and 12 identified no additional Phase I SAMAs to reduce HFO risk (NextEra, 2010).

13 For many of the Phase II SAMAs listed in the ER, the information provided did not sufficiently 14 describe the proposed modification. Therefore, the NRC staff asked the applicant to provide 15 more detailed descriptions of the modifications for several of the Phase II SAMA candidates 16 (NRC, 2010a). In response to the RAI, NextEra provided the requested information on the 17 modifications for SAMAs 44, 59, 94, 112, 114, 163, 186, and 187 (NextEra, 2011a).

18 The NRC staff questioned NextEra about lower cost alternatives to some of the SAMAs 19 evaluated (NRC, 2010a), including the following:

20

• use a portable generator to extend the coping time in loss of AC power events (to power 21 selected instrumentation and DC power to the turbine-driven auxiliary feedwater pump 22 provide alternate DC feeds (using a portable generator) to panels supplied only by DC 23 bus 24

• purchase or manufacture of a gagging device that could be used to close a stuck-open 25 steam generator safety valve for a SGTR event prior to core damage 26 In response to the RAIs, NextEra addressed the suggested lower cost alternatives 27 (NextEra, 20011). This is discussed further in Section F.6.2.

28 The NRC staff requested NextEra to clarify the Phase I screening criteria, which was described 29 in the ER as including the following two criteria that appear to not have been used:

30 (1) excessive implementation cost and (2) very low benefit (NRC, 2010a). NextEra responded 31 that these criterion, while they could have been used in the Phase I evaluation, were not used in 32 the Phase I screening evaluation in order to force evaluation of more SAMA candidates into the 33 Phase II evaluation so that the merit of each could be judged based on associated costs and 34 benefits (NextEra, 2011a).

35 The NRC staff asked NextEra to provide justification for the screening of SAMA 29, provide 36 capability for alternate injection via diesel-driven fire pump, in the Phase I evaluation on the 37 basis that it has already been implemented through an existing alternate mitigation strategy 38 (NRC, 2010a). In response to the RAI, NextEra responded that Seabrook has the capability to 39 use its diesel-driven fire pump to provide injection to the steam generators through 40 implementation of existing SAMGs (NextEra, 2011a). NextEra also stated that two portable 41 diesel-driven pumps are also available to provide injection using suction from the fire protection 42 system, the cooling tower basin, and the Browns River. Based on this clarification, the NRC 43 staff considers NextEras basis for screening SAMA 29 reasonable.

F-32

Appendix F 1 The NRC staff noted that SAMA 64, implement procedure and hardware modification for a 2 component cooling water header cross-tie, was screened in the Phase I evaluation because a 3 cross-tie already exists to support a maintenance activity. The staff asked NextEra to clarify if 4 the cross-tie between divisions A and B of the PCCW system is already provided for in existing 5 plant procedures (NRC, 2010a). In response to the RAI, NextEra clarified that the Seabrook 6 operating procedures do provide explicit instructions for alignment of the PCCW division A and 7 B cross-tie. Additionally, while the cross-tie is primarily used during maintenance activities, it 8 could be used during an off-normal event involving a failure of heat sink in one division with 9 failure of frontline components in the opposite division, provided that adequate time is available 10 (NextEra, 2011a).

11 The NRC staff questioned why SAMA 79, install bigger pilot operated relief valve so only one is 12 required, was screened in the Phase I evaluation based on the intent of the SAMA having 13 already been implemented when the success criterion is 2-of-2 PORVs needed for intermediate 14 head SI (NRC, 2010a). NextEra responded that the context of SAMA 79 was to increase the 15 capacity of the pressurizer PORVs such that opening of only one PORV would satisfy the feed 16 and bleed success criteria for all loss of feedwater-type sequences, which is all that is needed at 17 Seabrook if feed and bleed is provided by one of two high head charging pumps (NextEra, 18 2010). However, since opening of two PORVs is needed if feed is provided by one of two SI 19 pumps, NextEra provided a Phase II evaluation of this SAMA, the results of which are further 20 discussed in Section F.6.2.

21 The NRC staff asked NextEra to provide justification for the screening of SAMA 82, stage 22 backup fans in switchgear rooms, and SAMA 84, switch for emergency feedwater room fan 23 power supply to station batteries, in the Phase I evaluation on the basis that they are not 24 applicable to Seabrook (NRC, 2010a). In response to the RAI, NextEra explained that the 25 context of SAMA 82 was to enhance the availability and reliability of ventilation to the essential 26 switchgear rooms in the event of a loss of switchgear room ventilation. Additionally, this SAMA 27 is more accurately screened as its intent having been already implemented at Seabrook since 28 procedures already exist for maintaining acceptable switchgear room temperatures when 29 ventilation becomes unavailable, which includes opening doors and setting up portable fans 30 (NextEra, 2011a). The NRC staff considers NextEras clarification for SAMA 82 reasonable.

31 Regarding SAMA 84, NextEra explained that the context of this SAMA was to enhance the 32 availability and reliability of ventilation to the EFW pump house, in the event of a loss of pump 33 house ventilation, by switching the pump house ventilation fan(s) power supply to station 34 batteries. NextEra further stated that the initial screening of not applicable is incorrect 35 (NextEra, 2011a). NextEra further explained that since procedures already exist for maintaining 36 acceptable EFW pump house room temperatures when ventilation becomes unavailable, failure 37 of the already reliable ventilation system is not a significant contributor to CDF. Nevertheless, 38 NextEra provided a Phase II evaluation of this SAMA, the results of which are further discussed 39 in Section F.6.2.

40 The NRC staff noted that SAMA 92, use a fire water system as a backup source for the 41 containment spray system, was screened in the Phase I evaluation because the containment 42 spray function is not important early, yet basic events RCPCV456A.FC and RCPCV456B.FC, 43 spray valves fail to open on demand, appear on the LERF importance list (NRC, 2010a). In 44 response to the RAI, NextEra explained that these two basic events refer to modeling of the 45 PORVs and not the containment spray valves, that descriptions of these two events in the ER 46 inadvertently referred to the PORVs as PORV spray valves, that the PORV function is unrelated F-33

Appendix F 1 to the containment spray function, and that, therefore, no SAMA is necessary. The NRC staff 2 considers NextEras clarification reasonable.

3 The NRC staff also asked NextEra to provide justification for the screening of SAMA 105, delay 4 containment spray actuation after a large LOCA, and SAMA 191, remove the 135°F 5 temperature trip of the PCCW pumps, in the Phase I evaluation on the basis that they would 6 violate the current licensing basis (CLB) for Seabrook (NRC, 2010a). In response to the RAI, 7 NextEra provided a Phase II evaluation of these SAMAs, the results of which are further 8 discussed in Section F.6.2 (NextEra, 2011a).

9 The NRC staff requested that NextEra clarify the basis for screening SAMA 127, revise 10 emergency operating procedures (EOPs) to direct isolation of a faulted steam generator, in the 11 Phase I evaluation on the basis that it is already implemented (NRC, 2010a). NextEra 12 responded that the context of SAMA 127 was to have specific EOPs for isolation of the steam 13 generator for the purpose of reducing the consequences of a SGTR, and existing EOPs direct 14 specific operator actions to diagnose a SGTR and to perform its isolation. Additionally, existing 15 plant EOPs also specifically provide actions for the identification and isolation of a faulted steam 16 generator (NextEra, 2011a). The NRC staff considers NextEras clarification reasonable.

17 The NRC staff asked NextEra to clarify the screening of SAMA 188, containment flooding -

18 modify the containment integrated leak rate test (ILRT) 10-inch test flange to include a 5-inch 19 adapter with isolation valve based on the statement that flange and procedures exist 20 (NRC, 2010a). NextEra responded that the 10-inch flange with fire hose adapter has been 21 pre-fabricated, is stored in a designated and controlled area, and is available for attaching to the 22 10-inch ILRT flange to provide containment flooding via Severe Accident Guideline instructions 23 (NextEra, 2011a). NextEra further explained that pre-installation of the flange adapter will 24 provide no significant time savings in light of the containment flooding scenario evolution via the 25 fire hose connection which takes several days. The NRC staff considers NextEras clarification 26 reasonable.

27 The NRC staff notes that the set of SAMAs submitted is not all-inclusive since additional, 28 possibly even less expensive, design alternatives can always be postulated. However, the NRC 29 staff concludes that the benefits of any additional modifications are unlikely to exceed the 30 benefits of the modifications evaluated and that the alternative improvements would not likely 31 cost less than the least expensive alternatives evaluated, when the subsidiary costs associated 32 with maintenance, procedures, and training are considered.

33 The NRC staff concludes that NextEra used a systematic and comprehensive process for 34 identifying potential plant improvements for Seabrook, and the set of SAMAs evaluated in the 35 ER, together with those evaluated in response to NRC staff inquiries, is reasonably 36 comprehensive and, therefore, acceptable. This search included reviewing insights from the 37 plant-specific risk studies and reviewing plant improvements considered in previous SAMA 38 analyses. While explicit treatment of external events in the SAMA identification process was 39 limited, it is recognized that the prior implementation of plant modifications for fire risks and the 40 absence of external event vulnerabilities constituted reasonable justification for examining 41 primarily the internal events risk results for this purpose.

42 F.4 Risk Reduction Potential of Plant Improvements 43 NextEra evaluated the risk-reduction potential of the 61 SAMAs retained for the Phase II 44 evaluation in the ER and not screened for excessive cost. The majority of the SAMA F-34

Appendix F 1 evaluations were performed in a bounding fashion in that the SAMA was assumed to eliminate 2 the risk associated with the proposed enhancement. On balance, such calculations 3 overestimate the benefit and are conservative.

4 NextEra used model re-quantification to determine the potential benefits. The CDF, population 5 dose, and offsite economic cost reductions were estimated using the SSPSS-2006 PRA model 6 with a truncation level of 1x10-14 per year. The changes made to the model to quantify the 7 impact of SAMAs are detailed in Appendix F.A and Table F.7-1 of Attachment F to the ER 8 (NextEra, 2010). Tables F-6 and F-7 list the assumptions considered to estimate the risk 9 reduction for each of the evaluated analysis cases, the estimated risk reduction in terms 10 of percent reduction in CDF and population dose, the estimated total benefit (present value) of 11 the averted risk, and the Phase II SAMAs evaluated for each analysis case. The estimated 12 benefits reported in Tables F-6 and F-7 reflect the combined benefit in both internal and external 13 events. The Phase II SAMAs included in Tables F-6 and F-7 are the 61 Phase II SAMAs 14 evaluated in the ER and the additional SAMAs determined to be cost-beneficial in response to 15 NRC staff RAIs. The determination of the benefits for the various SAMAs is further discussed in 16 Section F.6.

17 The NRC staff questioned the assumptions used in evaluating the benefits or risk reduction 18 estimates of certain SAMAs provided in the ER (NRC, 2010a). For example, several SAMAs 19 (i.e., SAMA 179, SAMAs involving model case NOSGTR, and SAMAs involving model case 20 LOCA06) were reported to have a reduction in CDF used in the benefit calculation that was 21 somewhat different from the contribution to CDF reported in Table F.3.1.1.1-1 of the ER, and 22 the NRC asked NextEra to clarify these discrepancies. In response to the NRC staff RAI, 23 NextEra stated that each of the differences identified in the RAI were reviewed, and it was 24 determined that in each case the difference was due to rounding (NextEra, 2011a). NextEra 25 also clarified that the CDF contribution reported in Table F.3.1.1.1-1 was developed from PRA 26 documentation and that the CDF reduction used in the calculation of SAMA benefits is judged to 27 be more precise. The NRC staff considers NextEras explanation reasonable.

28 As discussed in Section F.2.2, NextEra provided the results of a sensitivity analysis that applied 29 a multiplier of 2.1 to account for the additional risk reduction from seismic events 30 (NextEra, 2011b). In this analysis, NextEra revised the modeling assumptions for several 31 SAMAs that were determined to have been modeled incorrectly (i.e., assigned to the wrong 32 analysis case) or were determined to be overly conservative. The revised modeling 33 assumptions are provided in Tables F-6 and F-7. The determination of the benefits in the 34 sensitivity analysis for the various SAMAs is discussed further in Section F.6.

35 The NRC staff has reviewed NextEras bases for calculating the risk reduction for the various 36 plant improvements and concludes that the rationale and assumptions for estimating risk 37 reduction are reasonable and generally conservative (i.e., the estimated risk reduction is higher 38 than what would actually be realized). Accordingly, the NRC staff based its estimates of averted 39 risk for the various SAMAs on NextEras risk reduction estimates.

F-35

Appendix F 1 Table F-6. SAMA cost and benefit screening analysis for Seabrook(a)

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty NOSBO Eliminate failure of 27 12 160K 300K >1M the EDGs (330K) (620K) 2Replace lead-acid batteries with fuel cells 14(m)Install a gas >1M turbine generator 16(m)Improve >1M uninterruptable power supplies 20Add a new backup >1M source of diesel cooling 161Modify EDG jacket >1M(l) heat exchanger SW supply & return to allow timely alignment of alternate cooling water source (supply & drain) from firewater, reactor makeup water (RMW),

dewatering (DW), etc.

190Add >1M synchronization on capability to SEPS diesel NOLOSP Eliminate LOOP 42 36 340K 640K >2.4M(l) events (700K) (1.3M) 13Install an additional buried offsite power source 24Bury offsite power >3M(l) lines 156Install alternate >7M(l) offsite power source that bypasses the switchyard; for example, use campus power source to energize Bus E5 or E6 (n)

BREAKER Eliminate failure of 1 <1 8K 15K Screened the 4 KV bus (17K) (32K) 21Develop procedures infeed breakers to repair or replace failed 4 kV breakers LOCA02 Eliminate failure of 68 52 470K 890K >5M(l) the high pressure (980K) (1.9M) 25Install an injection system independent active or passive high pressure injection system F-36

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty 26Provide an >5M(l) additional high pressure injection pump with independent diesel 39Replace two of the >5M(l) four electric SI pumps with diesel-powered pumps LOCA03 Eliminate failure of 11 29 160K 300K >1M the low pressure (340K) (640K) 28Add a diverse low injection system pressure injection system LOCA04 Eliminate RWST 28 12 160K 300K >1M(l) running out of (330K) (630K) 35Throttle low water pressure injection pumps either in medium or large-break LOCAs to maintain RWST inventory 106Install automatic >1M(l) containment spray pump header throttle valves LOCA01 Eliminate all small 7 2 33K 63K >1M LOCA events (70K) (130K) 41Create a reactor coolant depressurization system SW01 Eliminate the 1 1 10K 19K >100K dependency of the (21K) (40K) 43Add redundant DC SW pumps on DC control power for SW power pumps CCW01 Eliminate failure of 25 23 180K 350K >4M(l) the component (380K) (730K) 44Replace ECCS cooling water pump motors with air- (CCW) pumps cooled motors 59Install a digital feed >1M(l) water upgrade RCPLOCA Eliminate all RCP 11 12 92K 180K >1M seal LOCA events (170K) (370K) 55Install an independent RCP seal injection system with dedicated diesel 56(b)Install an >3M independent RCP seal injection system without dedicated diesel F-37

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty 167Install independent >1M seal injection pump (low volume pump) with automatic start 168Install independent >1M seal injection pump (low volume pump) with manual start 169Install independent >500K charging pump (high volume pump) with manual start 170Replace the >500K positive displacement pump (PDP) with a 3rd centrifugal pump; consider low volume and cooling water independence 172Evaluate >1M installation of a shutdown seal in the RCPs being developed by Westinghouse (l)

FW01 Eliminate all loss of 12 7 73K 140K >1M feedwater events (150K) (290K) 79(d)Install bigger pilot operated relief valve so only one is required HVAC2 Eliminate the 8 1 32K 61K >500K dependency of the (67K) (130K) 80Provide a redundant CS, SI, RHR, and train or means of CBS pumps on ventilation heating, ventilation, and air conditioning (HVAC)

OEFWVS Eliminate loss of <1 <1 <1K <1K >250K (e) EFW ventilation (<1K) (<2K) 84 Switch for EFW room fan power supply to station batteries CONT01 Eliminate all 0 36 160K 310K >3-6M (b) containment (340K) (650K) 91 Install a passive failures due to containment spray overpressurization system 93(b)Install an unfiltered >3M hardened containment vent F-38

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty 94Install a filtered >5M(l) containment vent to remove decay heat; Option 1: Gravel Bed Filter; Option 2: Multiple Venturi Scrubber 99(b)Strengthen >10M primary & secondary containment (e.g., add ribbing to containment shell) 102(b)Construct a >10M building to be connected to primary & secondary containment &

maintained at a vacuum 107(b)Install a >3-4M redundant containment spray system (g)

H2Burn Eliminate all 0 0 <1K <1K >100K hydrogen ignition & (<1K) (<1K) 96Provide post- burns accident containment inerting capability 108Install an >100K independent power supply to the hydrogen control system using either new batteries, a nonsafety grade portable generator, existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel 109Install a passive >100K hydrogen control system OLRPS Eliminate the 2 <1 7.2K 14K >100K (f) human failure to (15K) (29K) 105 Delay complete & ensure containment spray the RHR & low actuation after a large head safety LOCA injection (LHSI) transfer to long-term recirculation during large LOCA events F-39

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty CONT02p Contributes 50 0 19 100K 200K >500K percent of the risk (220K) (420K) 112Add redundant and reduction from diverse limit switches to eliminating failure each CIV of all CIVs 114Install self- >500K actuating CIVs LOCA06(p) Contributes 50 1 3 14K 27K >100K percent of the risk (30K) (60K) 113Increase leak reduction from testing of valves in eliminating all ISLOCA paths ISLOCA events LOCA06 Eliminate all 2 7 28K 53K >1M ISLOCA events (60K) (110K) 115Locate RHR inside containment 187Install RHR >190K isolation valve leakage monitoring system NOSGTR Eliminate all SGTR 3 17 86K 160K >500K events (180K) (345K) 119Institute a maintenance practice to perform a 100%

inspection of steam generator tubes during each refueling outage 121Increase the >500K pressure capacity of the secondary side so that a SGTR would not cause the relief valves to lift 125Route the >500K discharge from the main steam safety valves through a structure where a water spray would condense the steam & remove most of the fission products 126Install a highly >500K reliable (closed loop) steam generator shell-side heat removal system that relies on natural circulation & stored water sources 129Vent main steam >500K safety valves in containment F-40

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty NOATWS Eliminate all ATWS 3 11 70K 130K >500K events (150K) (280K) 130Add an independent boron injection system 131Add a system of >500K relief valves to prevent equipment damage from pressure spikes during an ATWS 133Install an ATWS >500K sized filtered containment vent to remove decay heat 174Provide alternate >500K scram button to remove power from motor generator (MG) sets to control rod (CR) drives LOCA05 Eliminate all piping 10 12 100K 200K >500K failure LOCAs (220K) (410K) 147Install digital large break LOCA protection system NOSLB Eliminate all steam 0 <1 3K 6K >500K line break events (7K) (13K) 153Install secondary side guard pipes up to the main steam isolation valves OSEPALL Eliminate failure of Not Not 33K 62K >750K (k) all operator actions Provided Provided (68K) (130K) 154 Modify SEPS to align & load the design to accommodate SEPS DGs automatic bus loading &

automatic bus alignment Case INDEPAC Eliminate failure 4 2 23K 45K 30K of operator action (48K) (95K) 157Provide to shed DC loads independent AC power to extend source for battery batteries to 12 chargers; for example, hours. Also, provide portable eliminate failure generator to charge to recover offsite station battery power for plant-related, grid-related, and weather-related LOOP events.(h) 159Install additional >1M batteries F-41

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty CST01 Eliminate CST 1 1 9K 16K >100K running out of (18K) (34K) 162Increase the water capacity margin of the CST 164Modify 10 >40K condensate filter flange to have a 21/2-inch female fire hose adapter with isolation valve (l)

Turbine-driven auxiliary Eliminate failure of 19 9 100K 190K >2M feedwater (TDAFW) the TDAFW train (210K) (400K) 163Install third EFW pump (steam-driven)

NORMW Guaranteed 10 8 75K 120K 50K success of RWST (160K) (300K) 165RWST fill from makeup for long-firewater during term sequences containment injection where modify 6 RWST flush recirculation is flange to have a 21/2- not available inch female fire hose adapter with isolation valve FIRE2 This SAMA has been implemented (NextEra, 2011b).

175Improve fire detection in turbine building relay room FIRE1 Eliminate control 1 <1 4K 7K >20K(l) room fire causing (8K) (15K) 179Fire induced LOCA opening of the response procedure from PORV and a LOCA alternate shutdown panel SEISMIC01 Eliminate all 9 12 100K 200K >600K(l) seismic relay (210K) (410K) 181Improve relay chatter failures chatter fragility SEISMIC02 Eliminate all 0 0 <1K <1K >500K seismic failures of (<1K) (<1K) 182Improve seismic EDGs or turbine-capacity of EDGs and driven EFW steam-driven EFW pump PURGE Eliminate 0 0 <1K <1K >20K possibility of (<1K) (<1K) 184Control & reduce containment purge time that the containment valves being open purge valves are in open at the time of an position event F-42

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty CISPRE Eliminate all CDF Not Not 11K 20K >500K (o) contribution from Provided Provided (23K) (43K) 186 Install pre-existing containment leakage containment monitoring system leakage IOF2SEPS Modify fault tree so 7 1 30K 60K >300K that one of two (60K) (120K) 189Modify or analyze SEPS DGs are SEPS capability; 1 of 2 required rather SEPS for LOOP non-SI than both SEPS loads, 2 of 2 for LOOP SI DGs being required loads PCTES Eliminate <1 <1 <1K <1K >100K (f) inadvertent failure (<1K) (<1K) 191 Remove the of the redundant 135°F temperature trip of TE/logic of the the PCCW pumps associated PCC division for both loss of PCCW initiating events &

loss of PCCW mitigative function NOCBFLD Eliminate control 25 6 160K 310K 200K building fire (340K) (640K) 192(i)Install a globe protection valve or flow limiting flooding initiators orifice upstream in the fire protection system V167AC Eliminate MOV 0 35 190K 365K 300K AC power (400K) (770K) 193(c)Hardware dependency by change to eliminate replacing the MOV AC power MOV with a fail-dependency closed AOV (a)

SAMAs in bold are potentially cost-beneficial.

(b)

This is retained as a quantitatively-evaluated Phase II SAMA in response to NRC staff RAI 3.g (NextEra, 20011).

(c)

This is a new SAMA identified in response to NRC staff RAI 2.f (NextEra, 2011a) and conference call clarification #7 (NRC, 2011a).

(d)

Evaluation of this SAMA is provided in response to NRC staff RAIs 5.g (NextEra, 2011a) and conference call clarification #14 (NRC, 2011a).

(e)

Evaluation of this SAMA is provided in response to NRC staff RAI 5.j (NextEra, 2011a).

(f)

Evaluation of these SAMAs is provided in response to NRC staff RAI 5.n (NextEra, 2011a) and conference call clarification #15 (NRC, 2011a).

(g)

Reduction in population dose is provided in response to NRC staff RAI 6.g (NextEra, 2011a).

(h)

Information is provided in response to NRC staff RAI 6.h (NextEra, 2011a).

(i)

This is a new SAMA identified and evaluated in response to NRC staff RAI 1.a (NextEra, 2011a) and conference call clarification #1 (NRC, 2011a).

(j)

Values in parenthesis are the results of the sensitivity analysis applying a multiplier of 2.1 to account for the additional risk of seismic events (NextEra, 2011b).

F-43

Appendix F

% Risk reduction Total benefit ($)(j)

Analysis case & Modeling Baseline Baseline Population Cost ($)

applicable SAMAs assumptions CDF (internal + with dose external) uncertainty (k)

The analysis case for SAMA 154 changed from NOSBO to OSEPALL in response to followup NRC staff RAI 4 (NextEra 2011b).

(l)

Cost updated in supplement to response to followup NRC staff RAI 4 (NextEra 2011c).

(m)

The analysis case for SAMAs 14 and 16 changed from NOLOSP to NOSBO in response to followup NRC staff RAI 4 (NextEra, 2011b).

(n)

In response to followup NRC staff RAI 4, NextEra determined that detailed procedures already exist for inspection and repair of the Seabrook 4 kV breakers, and this SAMA was, therefore, screened from further consideration (NextEra, 2011b).

(o)

The analysis case for SAMA 186 changed from CONT01 to CISPRE in response to followup NRC staff RAI 4 (NextEra, 2011b).

(p)

Modeling assumptions, risk reduction, and benefit results changed in response to followup NRC staff RAI 4 (NextEra, 2011b).

The revised risk reduction and benefits were estimated by the NRC staff based on the benefits estimated by NextEra for the sensitivity analysis.

1 F.5 Cost Impacts of Candidate Plant Improvements 2 NextEra developed plant-specific costs of implementing the 61 Phase II candidate SAMAs. An 3 expert panelcomposed of senior plant staff from the PRA group, the design group, operations, 4 and license renewaldeveloped the cost estimates based on their experience with developing 5 and implementing modifications at Seabrook. The NRC staff requested that NextEra describe 6 the level of detail used to develop the cost estimates (NRC, 2010a). In response to the RAI, 7 NextEra explained that the cost estimates were based on the experience and judgment of the 8 plant staff serving on the expert panel and that, in most cases, detailed cost estimates were not 9 developed because of the large margin between the estimated SAMA benefits and the 10 estimated implementation costs (NextEra, 2011a). The cost estimates conservatively did not 11 specifically account for inflation, contingencies, implementation obstacles, or replacement power 12 costs (RPC).

13 The NRC staff reviewed the bases for the applicants cost estimates (presented in Section F.7.2 14 and Table F.7-1 of Attachment F to the ER). For certain improvements, the NRC staff also 15 compared the cost estimates to estimates developed elsewhere for similar improvements, 16 including estimates developed as part of other licensees analyses of SAMAs for operating 17 reactors and advanced light-water reactors. In response to an RAI requesting a more detailed 18 description of the changes associated with Phase II SAMAs 44, 59, 94, 112, 114, 163, 186, and 19 187, NextEra provided additional information detailing the analysis and plant modifications 20 included in the cost estimate of each improvement (NextEra, 2011a). The staff reviewed the 21 costs and found them to be reasonable and generally consistent with estimates provided in 22 support of other plants analyses.

23 The NRC staff requested additional clarification on the estimated cost of more than $100,000 for 24 implementation of Phase II SAMA 113, increase leak testing of valves in ISLOCA paths, which 25 is high for what does not appear to be a hardware modification (NRC, 2010a). In response to 26 the RAI, NextEra explained that most of the ISLOCA valves that are candidates for this 27 enhancement are located inside containment, and leak testing of these ISLOCA valves is 28 typically done during plant refueling outages or cold shutdown when the valves are accessible.

29 Additionally, increased leak testing on a more frequent basis would require a costly plant 30 shutdown (NextEra, 2011a). Based on this additional information, the NRC staff considers this 31 estimated cost to be reasonable and acceptable for purposes of the SAMA evaluation.

F-44

Appendix F 1 The NRC staff noted that Phase I SAMA 65, install a digital feed water upgrade, has an 2 estimated implementation cost of $30 million, which is much larger than the estimated 3 implementation cost of more than $500,000 for Phase II SAMA 147, install digital large break 4 LOCA protection system. The NRC staff asked NextEra to explain the reason for this 5 difference between what appear to be similar modifications (NRC, 2010a). NextEra responded 6 that the estimated implementation cost of $30 million for Phase I SAMA 65 was based on a 7 detailed assessment of the costs associated with the Seabrook long-range plan for a digital 8 upgrade of the feedwater control system, while the estimated cost of more than $500,000 for 9 SAMA 147 was based on the judgment of the expert panel (NextEra, 2011a). NextEra also 10 noted that since the conservatively estimated benefit for SAMA 147 was much less than the 11 estimated implementation cost, developing a more detailed cost estimate for this SAMA was not 12 necessary. The NRC staff considers NextEras clarification reasonable.

13 The NRC staff requested additional clarification on the estimated cost of $30,000 for 14 implementation of Phase II SAMA 157, provide independent AC power source for battery 15 chargers, which seems low for what is described as a hardware change (NRC, 2010a). In 16 response to the RAI, NextEra explained that the cost estimate is based on expert panel 17 judgment and includes procurement of a small portable, nonsafety-related 480V generator and 18 associated connection cables, operation guideline development, and storage onsite in a 19 convenient location for ease in moving into position/connected if ever needed during an 20 extended SBO event (NextEra, 2011a). The NRC staff considers NextEras clarification 21 reasonable.

22 As discussed in Section F.2.2, NextEra provided the results of a sensitivity analysis that applied 23 a multiplier of 2.1 to account for the additional risk reduction from seismic events 24 (NextEra, 2011b). In this analysis, NextEra revised the implementation costs for several 25 SAMAs in which the estimated costs were determined to be overly conservative. The revised 26 implementation costs are provided in Tables F-6 and F-7. The staff reviewed the basis for each 27 of the revised costs and found them to be reasonable and, generally, consistent with estimates 28 provided in support of other plants analyses.

29 The NRC staff concludes that the cost estimates provided by NextEra are sufficient and 30 appropriate for use in the SAMA evaluation.

31 F.6 Cost-Benefit Comparison 32 NextEras cost-benefit analysis and the NRC staffs review are described in the following 33 sections.

34 F.6.1 NextEras Evaluation 35 The methodology used by NextEra was based primarily on NRCs guidance for performing 36 cost-benefit analysis, i.e., NUREG/BR-0184, Regulatory Analysis Technical Evaluation 37 Handbook (NRC, 1997a). The guidance involves determining the net value for each SAMA 38 according to the following formula:

39 Net Value = (APE + AOC + AOE + AOSC) - COE where, 40 APE = present value of averted public exposure ($)

41 AOC = present value of averted offsite property damage costs ($)

42 AOE = present value of averted occupational exposure costs ($)

F-45

Appendix F 1 AOSC = present value of averted onsite costs ($)

2 COE = cost of enhancement ($)

3 If the net value of a SAMA is negative, the cost of implementing the SAMA is larger than the 4 benefit associated with the SAMA, and it is not considered cost-beneficial. NextEras derivation 5 of each of the associated costs is summarized below.

6 NUREG/BR-0058 has recently been revised to reflect the NRCs policy on discount rates.

7 Revision 4 of NUREG/BR-0058 states that two sets of estimates should be developed, one at 8 3 percent and one at 7 percent (NRC, 2004). NextEra provided a base set of results using the 9 7 percent discount rate and a sensitivity study using the 3 percent discount rate 10 (NextEra, 2010).

11 Averted Public Exposure (APE) Costs 12 The APE costs were calculated using the following formula:

13 APE = Annual reduction in public exposure (person-rem/year) 14 x monetary equivalent of unit dose ($2,000 per person-rem) 15 x present value conversion factor (10.76 based on a 20-year period with a 16 7 percent discount rate) 17 As stated in NUREG/BR-0184 (NRC, 1997a), the monetary value of the public health risk after 18 discounting does not represent the expected reduction in public health risk due to a single 19 accident. Rather, it is the present value of a stream of potential losses extending over the 20 remaining lifetime (in this case, the renewal period) of the facility. Thus, it reflects the expected 21 annual loss due to a single accident, the possibility that such an accident could occur at any 22 time over the renewal period, and the effect of discounting these potential future losses to 23 present value. For the purposes of initial screening, which assumes elimination of all severe 24 accidents caused by internal and external events, NextEra calculated an APE of approximately 25 $230,400 for the 20-year license renewal period (NextEra, 2010).

26 Averted Offsite Property Damage Costs (AOC) 27 The AOCs were calculated using the following formula:

28 AOC = Annual CDF reduction 29 x offsite economic costs associated with a severe accident (on a per-30 event basis) 31 x present value conversion factor 32 This term represents the sum of the frequency-weighted offsite economic costs for each release 33 category, as obtained for the Level 3 risk analysis. For the purposes of initial screening, which 34 assumes elimination of all severe accidents caused by internal events, NextEra calculated an 35 annual offsite economic cost of about $23,500 based on the Level 3 risk analysis 36 (NextEra, 2011a). This results in a 7 percent-discounted value of approximately $253,300 for 37 the 20-year license renewal period.

F-46

Appendix F 1 Averted Occupational Exposure (AOE) Costs 2 The AOE costs were calculated using the following formula:

3 AOE = Annual CDF reduction 4 x occupational exposure per core damage event 5 x monetary equivalent of unit dose 6 x present value conversion factor 7 NextEra derived the values for AOE from information provided in Section 5.7.3 of the Regulatory 8 Analysis Technical Evaluation Handbook (NRC, 1997a). Best estimate values provided for 9 immediate occupational dose (3,300 person-rem) and long-term occupational dose (20,000 10 person-rem over a 10-year cleanup period) were used. The present value of these doses was 11 calculated using the equations provided in the handbook in conjunction with a monetary 12 equivalent of unit dose of $2,000 per person-rem, a real discount rate of 7 percent, and a time 13 period of 20 years to represent the license renewal period. For the purposes of initial screening, 14 which assumes elimination of all severe accidents caused by internal events, NextEra 15 calculated an AOE of approximately $5,500 for the 20-year license renewal period (NextEra, 16 2010).

17 Averted Onsite Costs 18 AOSC include averted cleanup and decontamination costs (ACC) and averted power 19 replacement costs. Repair and refurbishment costs are considered for recoverable accidents 20 only and not for severe accidents. NextEra derived the values for AOSC based on information 21 provided in Section 5.7.6 of NUREG/BR-0184, the Regulatory Analysis Technical Evaluation 22 Handbook (NRC, 1997a).

23 NextEra divided this cost element into two partsthe onsite cleanup and decontamination cost, 24 also commonly referred to as ACC, and the RPC.

25 ACC were calculated using the following formula:

26 ACC = Annual CDF reduction 27 x present value of cleanup costs per core damage event 28 x present value conversion factor 29 The total cost of cleanup and decontamination subsequent to a severe accident is estimated in 30 NUREG/BR-0184 to be $1.5x109 (undiscounted). This value was converted to present costs 31 over a 10-year cleanup period and integrated over the term of the proposed license extension.

32 For the purposes of initial screening, which assumes elimination of all severe accidents caused 33 by internal events, NextEra calculated an ACC of approximately $167,200 for the 20-year 34 license renewal period.

35 Long-term RPC were calculated using the following formula:

36 RPC = Annual CDF reduction 37 x present value of replacement power for a single event F-47

Appendix F 1 x factor to account for remaining service years for which replacement 2 power is required 3 x reactor power scaling factor 4 NextEra based its calculations on the rated Seabrook gross electric output of 1,290 megawatt 5 electric (MWe) and scaled up from the 910 MWe reference plant in NUREG/BR-0184 6 (NRC, 1997a). Therefore, NextEra applied a power scaling factor of 1,290/910 to determine the 7 RPC. For the purposes of initial screening, which assumes elimination of all severe accidents 8 caused by internal events, NextEra calculated an RPC of approximately $162,300 and an 9 AOSC of approximately $329,500 (sum of ACC of $167,200 and RPC of $162,300) for the 10 20-year license renewal period.

11 Using the above equations, NextEra estimated the total present dollar value equivalent 12 associated with eliminating severe accidents from internal and external events at Seabrook to 13 be about $819,000 (sum of APE of $230,400, AOC of $253,300, AOE of $5,500, and AOSC of 14 $329,500), also referred to as the maximum averted cost risk (MACR). Use of a multiplier of 2.1 15 to account for the additional risk from seismic events in the sensitivity analysis increases the 16 MACR, as estimated by the NRC staff, to $1.7 million.

17 NextEras Results 18 If the implementation costs for a candidate SAMA exceeded the calculated benefit, the SAMA 19 was considered not to be cost-beneficial. In the baseline analysis contained in the ER (using a 20 7 percent discount rate), NextEra identified one potentially cost-beneficial SAMA (SAMA 165).

21 Based on the consideration of analysis uncertainties, NextEra identified one additional 22 potentially cost-beneficial SAMA (SAMA 157). In response to NRC staff RAIs regarding the 23 SAMA identification process and updates to the PRA model, two additional potentially 24 cost-beneficial SAMAs were identified (SAMAs 192 and 193). In addition, in response to NRC 25 staff RAIs, NextEra provided the results of sensitivity analysis applying a multiplier of 2.1 to 26 account for additional SAMA benefits in external events due to a potentially larger seismic CDF 27 (NextEra, 2011; NextEra, 2011b). No additional potentially cost-beneficial SAMAs were 28 identified from this sensitivity analysis, which was performed for both the baseline and 29 uncertainty analyses.

30 The potentially cost-beneficial SAMAs for Seabrook are listed below:

31

• SAMA 157Provide independent AC power source for battery chargers 32

• SAMA 165RWST fill from firewater during containment injectionModify 6 inch RWST 33 flush flange to have a 21/2-inch female fire hose adapter with isolation valve 34

• SAMA 192Install a globe valve or flow limiting orifice upstream in the fire protection 35 system 36

• SAMA 193Hardware change to eliminate MOV AC power dependency 37 The potentially cost-beneficial SAMAs, and NextEras plans for further evaluation of these 38 SAMAs, are discussed in more detail in Section F.6.2.

39 F.6.2 Review of NextEras Cost-Benefit Evaluation 40 The cost-benefit analysis performed by NextEra was based primarily on NUREG/BR-0184 41 (NRC, 1997a) and discount rate guidelines in NUREG/BR-0058 (NRC, 2004), and it was F-48

Appendix F 1 executed consistent with this guidance. One SAMA was determined to be cost-beneficial in 2 NextEras baseline analysis in the ER (SAMA 165, as described above). NextEra stated that 3 this SAMA would be entered into the Seabrook long-range plan development process for further 4 implementation consideration (NextEra, 2010).

5 NextEra considered the impact that possible increases in benefits from analysis uncertainties 6 would have on the results of the SAMA assessment. In the ER, NextEra presents the results of 7 an uncertainty analysis of the internal and external events CDF for Seabrook, which indicates 8 that the 95th percentile value is a factor of 1.9 greater than the point estimate CDF for 9 Seabrook. Since none of the Phase I SAMAs were screened based on excessive cost or very 10 low benefit, a re-examination of the Phase I SAMAs based on the upper bound benefits was not 11 necessary. NextEra reexamined the Phase II SAMAs to determine if any would be potentially 12 cost-beneficial if the baseline benefits were increased by a factor of 1.9. One SAMA became 13 cost-beneficial in NextEras analysis (SAMA 157, as described above). Although not 14 cost-beneficial in the baseline analysis, NextEra stated that this SAMA would be entered into 15 the Seabrook long-range plan development process for further implementation consideration 16 (NextEra, 2010).

17 The NRC staff asked NextEra to describe how the uncertainty distribution was developed to 18 derive the 95th percentile CDF value and how the distribution is different for internal, fire, and 19 seismic CDF (NRC, 2010a). In response to the RAI, NextEra explained that the uncertainty 20 distribution was developed using a Monte Carlo sample size of 10,000 and a sequence bin 21 cutoff of 1x10-9, that the distribution included the integrated contribution from both internal and 22 external events, and that individual contributions for internal, fire, and seismic events were not 23 developed (NextEra, 2011a). In response to a followup RAI, NextEra further clarified that the 24 uncertainty analysis included uncertainty distributions for fire-initiating events, seismic-initiating 25 events, component seismic fragilities, operator actions, and component random failures 26 (NRC, 2011b). NextEra also noted that, while uncertainty distributions were not specifically 27 considered for hot short probabilities and non-suppression probabilities, numerous sensitivity 28 studies were performed to support the fire events and seismic events models to ensure the 29 reasonableness of key input parameters. The results of these sensitivity studies indicate that 30 the baseline fire and seismic results are relatively insensitive to reasonable variations in key 31 input parameters. Based on the results of these studies and the level of uncertainty applied in 32 the fire and seismic events analyses, NextEra concluded that the uncertainty distribution used 33 for the SAMA evaluation adequately reflects the uncertainty for both internal and external 34 events.

35 NextEra provided the results of additional sensitivity analyses in the ER, including the use of 36 3 percent and 8.5 percent discount rates, variations in MACCS2 input parameters (as discussed 37 in Section F.2.2), and a 41-year analysis period representing the remaining operating life of the 38 plant accounting for the expected 20-year period of extended operation. These analyses did not 39 identify any additional potentially cost-beneficial SAMAs.

40 SAMAs identified primarily on the basis of the internal events analysis could provide benefits in 41 certain external events, in addition to their benefits in internal events. Since the SSPSS-2006 42 PRA model is an integrated internal and external events model, NextEras evaluation accounted 43 for the potential risk reduction benefits associated with both internal and external events. The 44 NRC staff asked NextEra to assess the impact of updated 2008 seismic hazard curves by the 45 USGS on the Seabrook SAMA analysis (NRC, 2010a). As indicated in Section F.2.2, NextEra 46 responded with a sensitivity analysis in which a multiplier was applied to the estimated benefits 47 for internal events to account for the higher seismic CDF developed from the 2008 USGS F-49

Appendix F 1 seismic hazard curves (NextEra, 2011a). Since no SAMAs were screened in the Phase I 2 analysis on very low benefit or excessive implementation cost, NextEra did not reexamine the 3 Phase I SAMAs. NextEra did reexamine the Phase II SAMAs that were qualitatively screened 4 on high cost or very low benefit to determine if any of these SAMAs would be retained for further 5 analysis if the benefits (or MMACR) were increased by a factor of 2.1. As a result of this 6 analysis, the following SAMAs were further evaluated in the quantitative Phase II evaluation:

7

• SAMA 56Install an independent RCP seal injection system, without dedicated diesel 8

• SAMA 91Install a passive containment spray system 9

• SAMA 93Install an unfiltered, hardened containment vent 10 NextEra also provided a sensitivity analysis that reexamined the Phase II SAMAs to determine if 11 any would be potentially cost-beneficial if the baseline and uncertainty benefits were increased 12 by a factor of 2.1 (NextEra, 2011b). The baseline sensitivity analysis of the Phase II SAMAs 13 (using a multiplier of 2.1 and a 7 percent real discount rate) did not identify any additional 14 potentially cost-beneficial SAMAs. NextEra also reexamined the Phase II SAMAs to determine 15 if any would be potentially cost-beneficial if the baseline sensitivity analysis benefits were 16 increased by an additional factor of 1.9 (in addition to the multiplier of 2.1 for external events) to 17 account for uncertainties. The uncertainty sensitivity analysis did not identify any additional 18 potentially cost-beneficial SAMAs. The results of the sensitivity analysis for the baseline and 19 uncertainty evaluations are provided in Table F-6.

20 As indicated in Section F.2.2, in response to an NRC staff RAI, NextEra identified and evaluated 21 SAMA 192, install a globe valve or flow limiting orifice upstream in the fire protection system, 22 based on insights from the upgraded internal flooding PRA model (NextEra, 2011a). The 23 results of the evaluation of this SAMA are provided in Table F-6. This SAMA was determined 24 not to be cost-beneficial in the baseline analysis, but it was determined to be potentially 25 cost-beneficial in the uncertainty analysis. In response to a conference call clarification, 26 NextEra stated that this SAMA would be entered into the Seabrook long-range plan 27 development process for further implementation consideration (NRC, 2011a).

28 As indicated in Section F.3.2, in response to NRC staff RAIs and followup RAIs, NextEra 29 identified several additional SAMAs based on its review of the Level 1 and Level 2 basic events 30 importance lists, its review of initiating events, and its assessment of the feasibility of 31 non-procedural and training SAMAs for human error basic events. The additional SAMAs and 32 NextEras evaluation of each is summarized in Table F-7 (NextEra, 2011a; NextEra, 2011b).

33 This table also provides the results of the sensitivity analysis applying the multiplier of 2.1 to 34 account for the additional risk of seismic events (NextEra, 2011b). None of the SAMAs 35 identified in Table F-7 were determined to be cost-beneficial in either the baseline or uncertainty 36 analysis or in the sensitivity analysis.

F-50

Appendix F 1 Table F-7. Non-cost-beneficial SAMAs identified and evaluated in response to NRC staff 2 RAIs Total benefit ($)(i)

Analysis case & applicable SAMAs Modeling assumptions Baseline Baseline Cost ($)

(internal + with external) uncertainty E6S Eliminate all risk 39K 74K >500K(f) associated with Bus fault (82K) (160K)

Improve Bus E6 reliability, eliminate/reduce potential for bus fault Improve Bus E5 reliability, eliminate/reduce >500K(f) potential for bus fault Improve Bus E11B reliability, eliminate bus >500K(f) failure Improve Bus E11A reliability, eliminate bus >500K(f) failure SEPES Eliminate all SEPS 40K 76K >300K(f) hardware failures (84K) (159K)

Eliminate potential for SEPS failure; improve (NextEra, 2011b)

SEPS DG reliability PORVRS Eliminate all PORV 23K 43K >100K reclosure failures (48K) (91K)

Improve reliability of PORV reseat function, eliminate PORV reseat failures ORWS Eliminate failure of the 32K 61K >300K(f) human action to provide (67K) (130K)

Provide hardware change for automatic ECCS RWST makeup flow control Hardware change to provide auto-makeup to >300K(f)

RWST, eliminate operator action Hardware change for automatic control or >300K(f) eliminate operator action to maintain stable conditions CISPRE Eliminate all CDF 11K 20K >50-100K contribution from pre- (23K) (43K)

Hardware or procedural change to eliminate or existing containment reduce likelihood of small pre-existing leakage unidentified leakage OSEPALL Eliminate failure of all 33K 62K >750K(f) operator actions to align & (68K) (130K)

Hardware change for auto closure of SEPS load the SEPS DGs breaker to eliminate operator action Provide auto-start & load for SEPS DG(e) >750K(f)

OC12S Eliminate failure of the 3K 5K SAMA operator action to close (6K) (11K) 193(g)

Provide a hardware modification (additional valve V-167 signals or remote capability) to automatically close CIV V-167 F-51

Appendix F Total benefit ($)(i)

Analysis case & applicable SAMAs Modeling assumptions Baseline Baseline Cost ($)

(internal + with external) uncertainty DGP115A/B Eliminate the risk 9K 17K >100K contribution from release (19K) (36K)

Provide hardware modification to improve lube categories SE3, LL3, oil pump reliability SE1, & LL4 due to failure of the DG-1A engine driven lube oil pump to run on demand PCCTS Eliminate all failures of 29K 55K >250K(f) temperature elements (61K) (120K)

Improve PCC TE reliability, eliminate potential (TEs) TE-2171 & TE-2172 for TE failure XOSMPS Eliminate failure of the 21K 40K >100K human action to align (44K) (83K)

Provide a hardware modification for auto- containment sump control, eliminate operator action to align recirculation after core sump after core melt melt PCCLS Eliminate all risk 22K 42K >100K associated with heat (46K) (87K)

Improve PCC heat exchanger reliability, exchanger E17A & E17B eliminate potential for heat exchanger leakage leakage SWV5 Eliminate the risk 8K 16K >100K contribution from release (17K) (34K)

Improve SW secondary isolation MOV SWV-5 categories LL3, LL4, &

reliability, eliminate valve failure SE1 due to failure of SWV-5 XOEFW Eliminate failure of the 4K 8K >100K operator action to provide (9K) (16K)

Hardware for automatic feed flow, eliminate feed to the faulted steam potential for operator failure to feed steam generator generator SUFPS Two cases evaluated: 10K 19K >100K (21K) (39K)

Improve reliability of SUFP, eliminate potential Eliminate failure of MOV for SUFP failures(h) FW-V-163 to open on demand, which contributes approximately 23% of the risk associated with failure of the entire startup feedwater system (Analysis Case SUFPS)

Eliminate failure of MOV 10K 19K >100K FW-V-156 to open on (21K) (39K) demand, which contributes approximately 23% of the risk associated with failure of the entire startup feedwater system (Analysis Case SUFPS)

F-52

Appendix F Total benefit ($)(i)

Analysis case & applicable SAMAs Modeling assumptions Baseline Baseline Cost ($)

(internal + with external) uncertainty Improve reliability of SUFP, eliminate potential Eliminate all risk 6K 12K >100K for SUFP mechanical failures(h) associated with the (13K) (26K) startup feedwater pump FWP-113, which contributes approximately 15% of the risk associated with Analysis Case SUFPS Hardware change to improve SUFP reliability, Eliminate failure of 4K 7K >100K eliminate potential for SUFP/valve failure(h) recirculation valve FW- (8K) (15K)

PCV-4326 to open, which contributes approximately 9% of the risk associated with Analysis Case SUFPS Improve the reliability of the pre-lube pump via Eliminate failure of the 7K 14K >100K (c) installation of a redundant pump pre-lube oil pump, which (16K) (30K) contributes approximately 17.5% of the risk associated with Analysis Case SUFPS MEFWS Eliminate all risk 39K 73K >200K(f) associated with MD EFW (81K) (150K)

Hardware change to eliminate or reduce pump failures mechanical failures of MD EFW pump (installation of additional MD pump)

Hardware change to improve reliability, Eliminate failure of MOV 4K 7K >200K(f) eliminate or reduce mechanical failures of MD FW-V-347 to open, which (8K) (15K)

EFW pump/valves(h) contributes approximately 8.5% of the risk associated with Analysis Case MEFWS (f)

OTSIS Eliminate failure of the 28K 54K >300K human action to terminate (59K) (110K)

Implement hardware change to improve SI following successful reliability of SGTR control, eliminate or reduce cooldown &

operator failure to terminate SI depressurization of the SGTR Provide automatic control, eliminate or reduce >300K(f) operator failure to terminate SI UET Eliminate the risk 3K 6K >100K contribution from release (6K) (13K)

Improve hardware/procedures to reduce or categories LE1 & LL4 due eliminate basic event exposure probability, to basic event improve CRI availability ZZ.2PORV.NOCRI, ATWSunfavorable exposure time (UET) probability given 2 PORVs

& 3 safety valves (SVs) available, without CRI F-53

Appendix F Total benefit ($)(i)

Analysis case & applicable SAMAs Modeling assumptions Baseline Baseline Cost ($)

(internal + with external) uncertainty OSUFPS Eliminate failure of the 7K 13K >100K human action to start the (14K) (27K)

Provide auto-start of SUFP, eliminate potential SUFP for operator failure to start SUFP OSGRDS Eliminate failure of the 5K 9K >100K human action to (10K) (18K)

Implement hardware change to improve depressurize the RCS &

reliability of SGTR control, eliminate operator terminate flow to the action to depressurize ruptured steam generator Hardware change to eliminate operator action >300K(f) to depressurize in SGTR events (f)

Hardware change for automatic control or >300K eliminate operator action to cooldown RCS in SGTR events ORWCDS Eliminate failure of the 4K 8K >100K human action to cooldown (9K) (18K)

Implement hardware change to improve & depressurize the RCS reliability, eliminate operator action to to minimize leakage with cooldown/depressurize recirculation failure ORHCDS Eliminate failure of all 12K 24K >100K human actions related to (26K) (49K)

Hardware change for automatic control or cooldown/depressurizatio eliminate operator action to cooldown the RCS n of the RCS to support for RHR shutdown cooling in SGTR events RHR shutdown cooling during SGTR events CBSDVS Eliminate failure of MOVs <1K <1K >100K CBS-V-11 & CBS-V-17 (<2K) (<2K)

Hardware change to improve valve reliability, eliminate CBS discharge MOV failures XOVNTS Eliminate failure of the 30K 58K >300K(f) human action to vent (64K) (120K)

Hardware change for automatic venting containment control, eliminate need to perform late containment venting XOINES Eliminate all operator 4K 8K >100K actions to initiate (9K) (16K)

Hardware change for automatic initiation of containment injection containment injection gravity drain, eliminate operator action RXT1(b) Eliminate all reactor trip 41K 77K >250K events with the condenser (86K) (160K)

Improve overall Seabrook reliability; reduce available potential for plant trip initiating event frequency or reliability of mitigation systems to plant trip E7T(b) Eliminate all failures due 31K 59K >500K to 0.7 g seismic events (66K) (125K)

Reduce/eliminate impact of 0.7 g seismic event F-54

Appendix F Total benefit ($)(i)

Analysis case & applicable SAMAs Modeling assumptions Baseline Baseline Cost ($)

(internal + with external) uncertainty F4TREL(b) Eliminate all failures due 22K 42K >100K to a flood in the turbine (46K) (88K)

Protect relay room from potential impact from building resulting in a HELB LOOP FSGBE6(b) Eliminate failure of 14 28K >500K electrical Bus E6 due to a (30K) (60K)

Improve/reduce the CDF contribution of fire in switchgear room B switchgear room B fire events LOCA04 Eliminate RWST running 160K 300K >1M out of water (330K) (630K)

Provide hardware change for automatic alignment of recirculation, eliminate operator action(d)

(a)

Information in this table is generally from the RAI responses dated January 13, 2011 (NextEra, 2011a). Information that is supplemented or updated by the April 18, 2011, responses to NRC staff followup RAIs (NextEra, 2011b) is specifically noted.

(b)

Information on Analysis Cases RXT1, E7T, F4TREL, and FSGBE6 and associated SAMA candidates was provided in response to followup NRC staff RAI 1 (NextEra, 2011b). The results for the sensitivity analysis were estimated by the NRC staff using the multiplier of 2.1.

(c)

Information on this SAMA was provided in response to followup NRC staff RAI 5 (NextEra, 2011b). The results for the sensitivity analysis were estimated by the NRC staff using the multiplier of 2.1.

(d)

Information on this SAMA was provided in response to followup NRC staff RAI 4 and 6 (NextEra, 2011b). This SAMA was modeled using Analysis Case LOCA04, the benefits for which are taken from Table F-6 of this appendix.

(e)

The analysis case for this SAMA changed from OSPE1 to OSEPALL in response to followup NRC staff RAI 4 (NextEra, 2011b).

(f)

Cost was updated in response to followup NRC staff RAI 4 (NextEra, 2011b).

(g)

This SAMA is supplanted by SAMA 193, which replaces the MOV with a fail-closed AOV, and which has been determined to be cost-beneficial (NextEra, 2011b).

(h)

Modeling assumptions, risk reduction, and benefit results changed in response to followup NRC staff RAI 4 (NextEra, 2011b). The revised risk reduction and benefits were estimated by the NRC staff based on the benefits estimated by NextEra for the sensitivity analysis.

(i)

Values in parenthesis are the results of the sensitivity analysis applying a multiplier of 2.1 to account for the additional risk of seismic events (NextEra, 2011b).

1 In addition to the SAMAs identified in Table F-7, NextEra identified and evaluated SAMA 193, 2 hardware change to eliminate MOV AC power dependencies. The results of the evaluation of 3 this SAMA are provided in Table F-6. This SAMA was determined to not be cost-beneficial in 4 the baseline analysis, but it was determined to be potentially cost-beneficial in the uncertainty 5 analysis. In response to a conference call clarification, NextEra stated that this SAMA would be 6 entered into the Seabrook long-range plan development process for further implementation 7 consideration (NRC, 2011a).

8 As indicated in Section F.3.2, in response to an NRC staff RAI, NextEra identified and evaluated 9 a SAMA to make seismic upgrades to the CST (NextEra, 2011a). This SAMA was estimated 10 to have an implementation cost of more than $100,000. NextEra performed a bounding 11 analysis of the benefit of this SAMA by assuming that it eliminated structural failures of the CST 12 during all seismic-initiating events. The total baseline benefit (using a 7 percent real discount 13 rate) was estimated to be $1,000 and, after accounting for uncertainties, to be $2,000. Based 14 on this result, NextEra concluded that this SAMA was not cost-beneficial in either the baseline 15 or the uncertainty analysis. The NRC staff also concludes that this SAMA would not be F-55

Appendix F 1 cost-beneficial after applying the multiplier of 2.1 to account for the additional risk from seismic 2 events.

3 As indicated in Section F.3.2, in response to an NRC staff RAI, NextEra provided a Phase II 4 evaluation of the following SAMAs, which were originally screened in the Phase I evaluation 5 (NextEra, 2011a; NextEra, 2011b):

6

• SAMA 79Install bigger pilot operated relief valve so only one is required 7

• SAMA 84Switch for EFW room fan power supply to station batteries 8

• SAMA 105Delay containment spray actuation after a large LOCA 9

• SAMA 191Remove the 135°F temperature trip of the PCCW pumps 10 The results of the cost-benefit evaluation for these SAMAs are provided in Table F-6, which was 11 determined by NextEra to not be cost-beneficial in either the baseline or uncertainty analysis or 12 in the sensitivity analysis applying the 2.1 multiplier.

13 As indicated in Section F.3.2, in response to an NRC staff RAI, NextEra provided an evaluation 14 of the following two SAMAs identified as a result of its review of the cost-beneficial SAMAs from 15 prior SAMA analyses for five Westinghouse four-loop PWR sites (NextEra, 2011a):

16

• SAMA procedure change to ensure that the RCS cold leg water seals are not cleared 17 has an estimated implementation cost of $15-20,000. NextEra performed a bounding 18 analysis of the benefit of this SAMA by assuming that it eliminated all thermally-induced 19 SGTR events (Analysis Case XSGTIS). The total baseline benefit (using a 7 percent 20 real discount rate) was estimated to be less than $1,000 and, after accounting for 21 uncertainties, to be less than $1,000. Based on this result, NextEra concluded that this 22 SAMA was not cost-beneficial in either the baseline or the uncertainty analysis. NextEra 23 also concluded that this SAMA would not be cost-beneficial after applying the multiplier 24 of 2.1 to account for the additional risk from seismic events (NextEra, 2011b).

25

• SAMA installation of redundant parallel service water valves to the EDGs has an 26 estimated implementation cost of greater than $1 million (NextEra, 2011b). NextEra 27 performed a bounding analysis of the benefit of this SAMA by assuming that it eliminated 28 all SBO events. The total baseline benefit (using a 7 percent real discount rate) was 29 estimated to be $160,000 and, after accounting for uncertainties, to be $300,000. Based 30 on this result, NextEra concluded that this SAMA was not cost-beneficial in either the 31 baseline or the uncertainty analysis. NextEra also concluded that this SAMA would not 32 be cost-beneficial after applying the multiplier of 2.1 to account for the additional risk 33 from seismic events (NextEra, 2011b).

34 As indicated in Section F.3.2, for certain SAMAs considered in the ER, there may be 35 alternatives that could achieve much of the risk reduction at a lower cost (NRC, 2010a). The 36 NRC staff asked the applicant to evaluate additional lower cost alternatives to the SAMAs 37 considered in the ER, as summarized below:

38

• Use a portable generator to extend the coping time in loss of AC power events (to power 39 selected instrumentation and DC power to the turbine-driven AFW pump and provide 40 alternate DC feeds (using a portable generator) to panels supplied only by DC busIn 41 response to the NRC staff RAI, NextEra stated that these two alternatives are already 42 represented by SAMA 157, provide independent AC power source for battery chargers; 43 for example, provide portable generator to charge station battery, which was F-56

Appendix F 1 determined to be cost-beneficial (NextEra, 2011a). The NRC staff agrees with this 2 conclusion.

3

• Purchase or manufacture of a gagging device that could be used to close a stuck-open 4 steam generator safety valve for a SGTR event prior to core damageIn response to 5 the NRC staff RAI, NextEra provided a Phase II evaluation of this proposed alternative 6 (NextEra, 2011a). NextEra performed a bounding analysis of the benefit of this 7 alternative by assuming that it eliminated failure of the main steam safety valve to 8 re-close during a SGTR event, provided that operators were successful at controlling 9 EFW flow, SI, and RCS depressurization. The total baseline benefit (using a 7 percent 10 real discount rate) was estimated to be less than $1,000 and, after accounting for 11 uncertainties, to be less than $1,000. Based on this result, NextEra concluded that this 12 SAMA was not cost-beneficial in either the baseline or the uncertainty analysis for either 13 hardware or procedure changes. The NRC staff concludes that this alternative has been 14 adequately addressed. NextEra also concluded that this SAMA would not be 15 cost-beneficial after applying the multiplier of 2.1 to account for the additional risk from 16 seismic events (NextEra, 2011b).

17 The NRC staff noted that the evaluation of SAMA 80, provide a redundant train or means of 18 ventilation, assumes removal of HVAC dependence for CS, SI, RHR, and CBS pumps and 19 asked NextEra to provide an evaluation of a SAMA to remove the HVAC dependency for just 20 the highest risk system (NRC, 2010a). In response to the RAI, NextEra explained that, while 21 the estimated implementation cost to install a redundant HVAC train to all of these ECCS 22 pumps and systems was assumed to be greater than $500,000, installation of a redundant 23 HVAC train to any single ECCS pump or system is judged to be greater than $500,000 as well 24 (NextEra, 2011a). NextEra concluded the proposed SAMA would not be cost-beneficial given 25 that the maximum benefit of SAMA 80 was conservatively estimated to be $32,000 (using a 26 7 percent real discount rate) and to be $61,000 after accounting for uncertainties and that this 27 benefit would only decrease with an evaluation of fewer ECCS pumps and systems.

28 The NRC staff notes that all of the potentially cost-beneficial SAMAs (SAMAs 157, 165, 192, 29 and 193) identified in NextEras original or revised baseline and uncertainty analyses, and in 30 response to NRC staff RAIs, are included within the set of SAMAs that NextEra plans to enter 31 into the Seabrook long-range plan development process for further implementation 32 consideration. The NRC staff concludes that, with the exception of the potentially 33 cost-beneficial SAMAs discussed above, the costs of the other SAMAs evaluated would be 34 higher than the associated benefits.

35 F.7 Conclusions 36 NextEra compiled a list of 191 SAMAs based on a review of the most significant basic events 37 from the plant-specific PRA, insights from the plant-specific IPE and IPEEE, review of other 38 industry documentation, and insights from Seabrook personnel. A qualitative screening 39 removed SAMA candidates that had modified features not applicable to Seabrook due to design 40 differences, that were determined to have already been implemented at Seabrook or Seabrook 41 meets the intent of the SAMA, or that could be combined with another similar SAMA under 42 consideration. Based on this screening, 117 SAMAs were eliminated, leaving 74 candidate 43 SAMAs for evaluation.

44 An additional 13 SAMAs were eliminated due to having estimated implementation costs that 45 would exceed the dollar value associated with eliminating all severe accident risk at Seabrook, 46 leaving 61 candidate SAMAs for evaluation. For the remaining SAMA candidates, a more F-57

Appendix F 1 detailed design and cost estimate were developed, as shown in Table F-6. The cost-benefit 2 analyses showed that two of the SAMA candidates were potentially cost-beneficial in the 3 baseline analysis (SAMAs 157 and 165). NextEra performed additional analyses to evaluate 4 the impact of parameter choices and uncertainties on the results of the SAMA assessment. As 5 a result, no additional SAMAs were identified as potentially cost-beneficial in the ER. In 6 response to NRC staff RAIs, NextEra further identified two additional SAMAs (SAMAs 192 and 7 193) as being potentially cost-beneficial. NextEra has indicated that all four potentially 8 cost-beneficial SAMAs would be entered into the Seabrook long-range plan development 9 process for further implementation consideration 10 The NRC staff reviewed the NextEra analysis and concludes that the methods used and their 11 implementation were sound. The treatment of SAMA benefits and costs support the general 12 conclusion that the SAMA evaluations performed by NextEra are reasonable and sufficient for 13 the license renewal submittal. Although the treatment of SAMAs for external events was 14 somewhat limited, the likelihood of there being cost beneficial enhancements in this area was 15 minimized by improvements that have been realized as a result of the IPEEE process and 16 inclusion of a multiplier to account for the additional risk of seismic events.

17 The NRC staff concurs with NextEras identification of potentially cost-beneficial SAMAs. Given 18 the potential for cost beneficial risk reduction, the NRC staff agrees that further evaluation of 19 SAMAs 157, 165, 192, and 193 by NextEra through its long-range planning process is 20 appropriate. As stated by the applicant, the four potentially cost-beneficial SAMAs are not 21 aging-related. The staff reviewed SAMAs 157, 165, 192, and 193. These mitigative alternatives 22 do not involve aging management of passive, long-lived systems, structures, and components 23 during the period of extended operation. Therefore, they need not be implemented as part of 24 license renewal pursuant to Title 10 of the Code of Federal regulations (CFR), Part 54.

25 F.8 References 26 American Society of Mechanical Engineers (ASME), 2003, Addenda to ASME RA-S-2002, 27 Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications, ASME 28 RA-Sa-2003, December 5, 2003.

29 ASME, 2009, Addenda to ASME RA-S-2008, Standard for Level 1/Large Early Release 30 Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications, ASME 31 RA-Sa-2009, February 2, 2009.

32 Electric Power Research Institute (EPRI), 1988, A Methodology for Assessment of Nuclear 33 Power Plant Seismic Margin, EPRI NP-6041, Revision 0, Palo Alto, CA, August 1988.

34 EPRI, 1992, Fire-Induced Vulnerability Evaluation (FIVE), EPRI TR-100370, Revision 0, Palo 35 Alto, CA, April 1992.

36 New Hampshire Yankee (NHY), 1991, Individual Plant Examination Report for Seabrook 37 Station, March 1, 1991.

38 NextEra Energy Seabrook, LLC. (NextEra), 2010, Seabrook Station-License Renewal 39 Application, Applicants Environmental Report, Operating License Renewal Stage, 40 May 25, 2010, Agencywide Documents Access and Management System (ADAMS) Accession 41 Nos. ML101590092 and ML101590089.

F-58

Appendix F 1 NextEra, 2011a, Letter from Paul O. Freeman, NextEra, to U.S. NRC Document Control Desk.

2

Subject:

Seabrook Station, Response to Request for Additional Information, NextEra Energy 3 Seabrook License Renewal Application, Seabrook, NH, January 13, 2011, ADAMS Accession 4 No. ML110140810.

5 NextEra, 2011b, Letter from Paul O. Freeman, NextEra, to U.S. NRC Document Control Desk.

6

Subject:

Seabrook Station, Response to Request for Additional Information, NextEra Energy 7 Seabrook License Renewal Application, Seabrook, NH, April 18, 2011, ADAMS Accession 8 No. ML11122A075.

9 NextEra, 2011c, Letter from Paul O. Freeman, NextEra, to U.S. NRC Document Control Desk.

10

Subject:

Seabrook Station, Supplement to Response to Request for Additional Information, 11 NextEra Energy Seabrook License Renewal Application, Seabrook, NH, June 10, 2011, 12 ADAMS Accession No. ML11166A255.

13 North Atlantic Energy Service Corp. (NAESC), 1992, Individual Plant Examination External 14 Events Report for Seabrook Station, October 2, 1992, ADAMS Accession No. ML080100029.

15 Nuclear Energy Institute (NEI), 2005, Severe Accident Mitigation Alternative (SAMA) Analysis 16 Guidance Document, NEI 05-01 (Revision A), Washington, D.C., November 2005.

17 Pickard, Lowe, and Garrick, Inc. (PLG), 1983, Seabrook Station Probabilistic Safety 18 Assessment, prepared for the Public Service Company of New Hampshire and Yankee Atomic 19 Electric Company, PLG-0300, December 1982.

20 U. S. Geologic Survey (USGS), 2008, 2008 NSHM Gridded Data, Peak Ground Acceleration, 21 Available URL: http://earthquake.usgs.gov/hazards/products/conterminous/2008/data/.

22 U.S. Nuclear Regulatory Commission (NRC), 1975, Standard Review Plan for the Review of 23 Safety Analysis Report for Nuclear Power Plants, NUREG-0800, Washington, D.C.,

24 November 1975.

25 NRC, 1983, PRA Procedure Guide, NUREG/CR-2300, Washington, D.C., January 1983.

26 NRC, 1988, GL 88-20, Individual Plant Examination for Severe Accident Vulnerabilities, 27 November 23, 1988.

28 NRC, 1990, Severe Accident Risks: An Assessment for Five U.S. Nuclear Power Plants, 29 NUREG-1150, Washington, D.C., December 1990.

30 NRC, 1991, GL No. 88-20, Individual Plant Examination of External Events for Severe Accident 31 Vulnerabilities, NUREG-1407, Washington, D.C., Supplement 4, June 28, 1991.

32 NRC, 1992, Letter from Gordon E. Edison, U.S. NRC, to Ted C. Feigenbaum, NHY,

Subject:

33 Staff Evaluation of Seabrook Individual Plant Examination (IPE)Internal Events, GL 88-20 34 (TAC No. M74466), Washington, D.C., February 28, 1992.

35 NRC, 1997a, Regulatory Analysis Technical Evaluation Handbook, NUREG/BR-0184, 36 Washington, D.C., January 1997.

37 NRC, 1997b, Individual Plant Examination Program: Perspectives on Reactor Safety and Plant 38 Performance, NUREG-1560, Washington, D.C., December 1997.

F-59

Appendix F 1 NRC, 1998, Code Manual for MACCS2: Volume 1, Users Guide, NUREG/CR-6613, 2 Washington, D.C., May 1998.

3 NRC, 2001, Letter from Victor Nerses, U.S. NRC, to Ted C. Feigenbaum, NAESC.

Subject:

4 Seabrook Station, Unit No. 1Individual Plant Examination of External Events (IPEEE) (TAC 5 No. M83673), Washington, D.C., May 2, 2001, ADAMS Accession No. ML010320252.

6 NRC, 2003, Sector Population, Land Fraction, and Economic Estimation Program, 7 SECPOP: NUREG/CR-6525, Washington D.C., April 2003 8 NRC, 2004, Regulatory Analysis Guidelines of the U.S. Nuclear Regulatory Commission, 9 NUREG/BR-0058, Washington, D.C., Revision 4, September 2004.

10 NRC, 2010a, Letter from Michael Wentzel, U.S. NRC, to Paul Freeman, NextEra.

Subject:

11 Request for Additional Information for the Review of the Seabrook Station License Renewal 12 Application-SAMA Review (TAC No. ME3959), Washington, D.C., November 16, 2010, 13 ADAMS Accession No. ML103090215.

14 NRC, 2010b, NRC Information Notice 2010-18: Generic Issue 199 (GI-199), Implications of 15 Updated Probabilistic Seismic Hazard Estimates in Central and Eastern United States on 16 Existing Plants, Washington, D.C., September 2, 2010, ADAMS Accession No. ML101970221.

17 NRC, 2011a, Memorandum to NextEra from Michael J. Wentzel, U.S. NRC.

Subject:

Summary 18 of Telephone Conference Calls held on February 15, 2011, between the U.S. Nuclear 19 Regulatory Commission and NextEra Energy Seabrook, LLC, to Clarify the Responses to the 20 Requests for Additional Information Pertaining to the Severe Accident Mitigation Alternatives 21 Review of the Seabrook Station License Renewal Application (TAC No. ME3959),

22 Washington, D.C., February 28, 2011, ADAMS Accession No. ML110490165.

23 NRC, 2011b, Letter from Bo Pham, U.S. NRC, to Paul Freeman, NextEra.

Subject:

Schedule 24 Revision and Request for Additional Information for the Review of the Seabrook Station License 25 Renewal Application Environmental Review (TAC Number ME3959), Washington, D.C.,

26 March 4, 2011, ADAMS Accession No. ML110590638.

F-60

NRC FORM 335 U.S. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER (12-2010) (Assigned by NRC, Add Vol., Supp., Rev.,

NRCMD 3.7 and Addendum Numbers, if any.)

BIBLIOGRAPHIC DATA SHEET (See instructions on the reverse) NUREG-1437, Supplement 46

2. TITLE AND SUBTITLE 3. DATE REPORT PUBLISHED Generic Environemental Impact Statement for License Renewal of Nuclear Plants (GEIS) MONTH YEAR Supplement 46 Regarding Seabrook Station Draft Report July 2011

4. FIN OR GRANT NUMBER

5. AUTHOR(S) 6. TYPE OF REPORT See Chapter 10 Technical

7. PERIOD COVERED (Inclusive Dates)

8. PERFORMING ORGANIZATION - NAME AND ADDRESS (If NRC, provide Division, Office or Region, U.S. Nuclear Regulatory Commission, and mailing address; if contractor, provide name and mailing address.)

Division of License Renewal Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 2055-0001

9. SPONSORING ORGANIZATION - NAME AND ADDRESS (If NRC, type "Same as above"; if contractor, provide NRC Division, Office or Region, U.S. Nuclear Regulatory Commission, and mailing address.)

Same as above

10. SUPPLEMENTARY NOTES Docket No. 50-443

11. ABSTRACT (200 words or less)

This draft supplemental impact statement (SEIS) has been prepared in response to an application submitted by NextEra Energy Seabrook, LLC to renew the operating license for Seabrook Station (Seabrook) for an additional 20 years.

This draft SEIS includes the preliminary analysis that evaluates the environmental impacts of the proposed action and alternatives to the proposed action. Alternatives considered include replacement power from new natural-gas-fired combined-cycle generation; new nuclear generation; a combination alternative that includes some natural-gas-fired capacity, and a wind-power component; and the no-action alternative, not renewing the license.

The NRC's preliminary recommendation is that the adverse environmental impacts of license renewal for Seabrook are not great enough to deny the option of license renewal for energy-planning decision makers.

12. KEY WORDS/DESCRIPTORS (List words or phrases that will assist researchers in locating the report.) 13. AVAILABILITY STATEMENT Seabrook Station Unlimited

14. SECURITY CLASSIFICATION Seabrook NextEra Energy Seabrook, LLC (This Page)

Supplement to the Generic Environmental Impact Statement Unclassified SEIS (This Report)

GEIS Unclassified National Environmental Policy Act NEPA 15. NUMBER OF PAGES License Renewal NUREG-1437, Supplement 46 16. PRICE NRC FORM 335 (12-2010)

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, DC 20555-0001

---

OFFICIAL BUSINESS

NUREG-1437, Generic Environmental Impact Statement for License Renewal July 2011 Supplement 46 of Nuclear Plants Regarding Seabrook Station Draft