ML101590089

Seabrook Station - Applicant'S Environment Report Operating License Renewal Stage, Page C-1 Through Page F.A-5

ML101590089
Person / Time
Site:	Seabrook
Issue date:	05/25/2010
From:	NextEra Energy Seabrook
To:	Office of Nuclear Reactor Regulation
References
SBK-L-10077
Download: ML101590089 (315)

Text

Appendix E -Environmental Report Attachment C Special Status Species Correspondence ATTACHMENT C SPECIAL STATUS SPECIES CORRESPONDENCE Letter Page Michael O'Keefe (FPL Energy Seabrook) to Anthony Tur (U.S. Fish and W ild life S e rvice) ...................................................................................

..C -2 Eric Derleth (U.S. Fish and Wildlife Service) to Michael O'Keefe (FPL Energy Seabrook)

..............................................................................

C -9 Michael O'Keefe (FPL Energy Seabrook) to Mary Colligan (National M arine Fisheries S erv ice) ..............................................................................

C -12 Michael O'Keefe (FPL Energy Seabrook) to Melissa Coppola (New Hampshire Natural Heritage Bureau) ...................................................

C-19 Melissa Coppola (New Hampshire Natural Heritage Bureau) to M ichael O'Keefe (FPL Energy Seabrook)

.......................................................

C-26 Michael O'Keefe (FPL Energy Seabrook) to Emily Holt (Massachusetts D ivision of Fisheries and W ildlife) ..................................................................

C -59 Thomas W. French (Massachusetts Division of Fisheries and Wildlife) to M ichael O'Keefe (FPL Energy Seabrook)

.......................................................

C-65 Seabrook Station Unit 1 Page C-1 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence 0 FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7050 April 13, 2009 SBK-L-09049 U.S. Fish and Wildlife Service New Hampshire Field Office Endangered Species Program 70 Commercial Street, Suite 300 Concord, NH 03301 Attn: Anthony Tur Seabrook Station Request for Information on Threatened or Endangered Species FPL Energy Seabrook, LLC (FPL Energy Seabrook), the owner of a controlling interest in and the operator of Seabrook Station plans to apply to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the Operating License for 20 years beyond the current expiration date.The current NRC Operating License for Seabrook Station expires at midnight on March 15, 2030. FPL Energy Seabrook plans to submit its application to the NRC in the second quarter of 2010.FPL Energy Seabrook is contacting the U.S. Fish and Wildlife Service in order to obtain input regarding issues that may need to be addressed in the Seabrook Station license renewal environmental reports, and to help identify any information that would be helpful to expedite consultation with the NRC in the future, if necessary.

The NRC requires that the license renewal application for Seabrook Station include environmental reports describing potential environmental impacts from refurbishment necessary for license renewal and from continued operations of the site and its associated transmission corridors during the renewal term. Transmission corridors from Seabrook Station extend into Massachusetts.

One of these potential environmental impacts would be the potential effect caused by activities specifically related to license renewal on threatened or endangered species located on the Seabrook Station site and its immediate environs, regardless of ownership or control of the land. Accordingly, the NRC requires that the environmental report for each an FPL Group company Seabrook Station Unit 1 Page C-2 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence U.S. Fish and Wildlife Service Page 2 license renewal application assess such a potential effect in accordance with the Endangered Species Act (10 CFR 51.53). Later, during its review of the proposed license renewals pursuant to the National Environmental Policy Act (NEPA), the NRC will use that assessment to evaluate whether a basis exists to request consultation with your office under Section 7 of the Endangered Species Act.Seabrook Station is located in the town of Seabrook, New Hampshire on the western shore of Hampton Harbor, approximately two miles west of the Atlantic Ocean (Figure 1). The site is bounded on the north, east and south by estuarine marshlands, veined with man-made ditches and tidal creeks. Over 400 acres of the site property are marshland and the majority of the remaining upland has been developed as part of the station. The upland component is generally low quality for wildlife and is not an important natural resource area.Three transmission lines operating at 345 kV were constructed to deliver Seabrook Station's electrical output to the New England 345 kV transmission grid (Figure 2). These lines run through a variety of common natural and man-influenced habitats in New Hampshire and Massachusetts.

These transmission corridors are considered by the NRC to be within the scope of its environmental reviews for the Seabrook license renewal. These transmission corridors are owned and maintained by Public Service Company of New Hampshire (PSNH) and National Grid (NGRID). The first line runs north 17 miles (27.4 kin) from Seabrook Station to Newington Station, located in Newington, NH. Immediately north of Seabrook Station, this line crosses the salt marsh on a previously existing rail bed, generally following the 1-95 corridor thereafter.

A second line runs east then south for approximately 30 miles (47.9 kin) to the Scobie Pond Substation in Londonderry, NH. A third line extends approximately 39 miles (63.2 kin) south and southwest from Seabrook Station to the Tewksbury Substation, in Tewksbury, MA.Based on a review of information available on the New Hampshire Natural Heritage Program website (town records of rare species and natural communities), information provided by the Massachusetts Natural heritage, and Endangered Species Program, and previous on-site surveys, FPL Energy Seabrook believes that no federal or state-listed threatened or endangered plant or animal species resides on the Seabrook Station site. However, some state-listed threatened terrestrial animal species have potential to occur within Rockingham County and the counties crossed by the transmission corridors (see Table 1), and these species may occasionally migrate through the sites. Also, Atlantic Sturgeon, Shortnose Sturgeon and five species of federally-listed sea turtles may occur offshore in the Atlantic Ocean near the Seabrook Station site. FPL Energy Seabrook is contacting the National Oceanic and Atmospheric Administration

-National Marine Fisheries Service regarding these marine species.Seabrook Station has a once-through heat dissipation system that withdraws water from the western Gulf of Maine through three offshore, submerged intake structures located approximately

1.3 miles

(2.1 kin) offshore in about 60 feet (18.3 m) of water (Figure 3). The three intake structures are approximately 110 feet (33.5 m) apart and each has a 9-10 foot (2.7-3.0 m) inside diameter vertical intake shaft. A submerged concrete structure is mounted on the top of each structure to minimize fish entrapment by reducing the intake velocity to 0.5 ft per second. These intakes were modified in 1999 with additional vertical bars to prevent the intake of Marine Mammals.Seabrook Station Unit 1 Page C-3 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence U.S. Fish and Wildlife Service Page 3 A single Atlantic sturgeon was captured near Seabrook prior to 1987, during site gill-net monitoring.

Although five sea turtle species could occur in this portion of the Atlantic, none have been reported near Seabrook or its intake/discharge structures nor are they likely to be entrapped at the intakes given the low intake and the presence of vertical bars on the intake structure.

FPL Energy Seabrook does not expect Seabrook Station operation during the license renewal term (an additional 20 years) to adversely affect threatened or endangered species at the station site, the immediate environs, or the transmission line corridors because license renewal will not alter existing operations.

No expansion of existing facilities is planned, and no structural modifications or other refurbishments have been identified that are necessary to support license renewal. Public Service Company of New Hampshire and National Grid have established management procedures for transmission lines that involve minimal disturbance of land, wetlands, and streams and are unlikely to adversely affect any threatened or endangered species.After review of the information provided in this letter, FPL Energy Seabrook would appreciate a letter detailing any concerns the U.S. Fish and Wildlife Service may have about any listed species or critical habitat in the area of the Seabrook Station site and the associated transmission corridors, or alternatively, confirming our conclusion that operation of Seabrook over the license renewal terms would have no effect on any threatened or endangered species. FPL Energy Seabrook will include copies of this letter and your response in the environmental reports that will be submitted to the NRC as part of the Seabrook Station license renewal application.

Letters detailing any concerns would be appreciated by June 30, 2009 to support the current submittal schedule.If you have any questions regarding this information, please contact me, at (603) 773-7745.Thank you in advance for your assistance.

Sincerely yours, Michael O'Keefe Licensing Manager

Enclosure:

Figure I -Location of Seabrook Station Figure 2 -Transmission lines associated with Seabrook Figure 3 -Diagram of Intake and Discharge Systems Table I -Endangered and Threatened Species Recorded in Rockingham County and Counties Crossed by Transmission Lines Seabrook Station Unit 1 Page C-4 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence Legend B.M#. O.di-= Prhooy Road~ tt ond.r Seabrook Statin Propotty Boonry-UranAs..N S0 05 1 2Mie Figure 1 General Location of Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-5 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Legend A Substation

--m 345 kV Transmlssion Une ,- iInterstate

= Primary Road mSeabrook Station~State Boundary I MjCounty Boundary Wfter SUrban Area Crane Pond WMA FiRsh and Wildifte Service N t0 1 2 4 5 I ies Figure 2 Transmission Lines Associated with the Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-6 Appendix E -Environmental Report Attachment C Special Status Species Correspondence DISCHARGE TUNNEL AND SHAFTS Seabrook Plant Site Figure 3 Cooling Water Intake/Discharge Structures for Seabrook Station Nuclear Power Plant Drawings not to scale Seabrook Station Unit 1 License Renewal Application Page C-7 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Table 1. Endangered and Threatened Species Recorded in Rockingham County and Counties*

Crossed by Transmission Lines.Federal State Species Common Name Status** Status**Birds Charadrius melodus Falco peregrinus Haliaeetus leucocephalus Sterna dougallii Vermivora chrysoptera Fish Acipenser brevirostrum Acipenser oxyrynchus Mammals Sylvilagus transitionalis Plants Aristida purpurascens Carex bullata Carex striata var. brevis Carex trichocarpa Celtis occidentalis Cyperus engelmannhi Gaylussacia dumosa Gentianopsis crinita Hottonia inflata Houstonia Iongifolia Hypoxis hirsuta Iris prismatica Isotria meleoloides Lespedeza virginica Liatris scariosa var. novae-angliae Prunus americana Platanthera flava var. herbiola Sparganium eutycarpum Sporobolus cryptandrus Triosteum aurantiacum Viola pedata Reptiles Caretta caretta Chelonia mydas Clemmys guttata Coluber constrictor Dermochelys coriacea Emydoidea blandingni Eretmochelys imbricata Heterodon platyhinos Lepidochelys kempli Piping plover Peregrine falcon Bald eagle Roseate tern Golden-winged warbler Shortnose sturgeon Atlantic sturgeon New England cottontail Purple needlegrass Inflated sedge Walter's sedge Hairy-fruited edge Hackberry Engelmann's Umbrella-sedge Dwarf huckleberry Fringed gentian Featherfoil Long-leaved bluets Hairy stargrass Slender blue flag Small-whorled pogonia Slender bush-clover Northern blazing star American plum Pale green orchid Large bur-reed Sand dropseed Orange horse-gentian Bird's-foot violet Loggerhead sea turtle Green sea turtle Spotted turtle Black racer Leatherback sea turtle Blanding's turtle Hawksbill sea turtle Eastern hognose snake Kemp's ridley sea turtle NHE, NHT NHT NHE, MAE MAE NHE, MAE MAE NHE MAT NHE NHE NHE NHT MAT NHT NHT NHE NHE NHE NHT NHE NHE NHE NHT NHT NHT NHE NHT MAT MAT NHT NHT MAE NHE, MAE MAE NHE MAE*Essex and Middlesex Counties in Massachusetts.

• • Status:

E=federal endangered, T=federal threatened, C=federal candidate, MAE-Massachusetts endangered, MAT=Massachusetts threatened, NHE=New Hampshire endangered, NHT=New Hampshire threatened, and Not listed.Seabrook Station Unit 1 License Renewal Application Page C-8 Appendix E -Environmental Report Attachment C Special Status Species Correspondence United States Department of the Interior FISH AND WILDLIFE SERVICE New England Field Office 70 Commercial Street, Suite 300 Concord, New Hampshire 03301-5087 RECEIVED http://www.fws.gov/northeast/newenglandfieldoffice MAY 19 2009 0 .I ClIt.k-q M.D. O'Keefe May 15, 2009 Michael O'Keefe FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874

Dear Mr. O'Keefe:

This responds to your recent correspondence requesting information on the presence of federally-listed and/or proposed endangered or threatened species in relation to the Seabrook Station (Station)in Seabrook, New Hampshire.

FPL Energy Seabrook Station plans to apply to the Nuclear Regulatory Commission for renewal of the Operating License for 20 years beyond the current expiration date of March 15, 2030.No federally-listed or proposed, threatened or endangered species or critical habitat under the jurisdiction of the U.S. Fish and Wildlife Service are known to occur in the project areas. However, the federally-threatened piping plover (Charadrius melodus) is known to nest on the coastal beaches located approximately

1.8 miles

east of the Station. This office is not aware of any impacts to the piping plover that could be attributed to the operation of the Station. In addition, the federally-endangered roseate tern (Sterna dougallii) is known to occur in the coastal waters of New Hampshire and is likely to be found in the vicinity of the cooling water intake and discharge structures.

Because these structures are located approximately

1.3 miles

offshore in about 60 feet of water, no effects to the roseate tern or its habitat are known or anticipated.

Preparation of a Biological Assessment or further consultation with us under Section 7 of the Endangered Species Act is not required.While there are no occurrences of federally-listed species in the project area, the New England cottontail (Sylvilagus transitionalis) is known to occur in the Towns of Derry and Londonderry, New Hampshire.

Furthermore, our records indicate that the New England cottontail has been recorded at a site just east of the Scobie Pond substation in Derry, New Hampshire.

The U.S; Fish and Wildlife Service announced the New England cottontail as a Candidate Species for listing on September 12, 2006 in the Federal Register (50 CFR part 17). While the New England cottontail remains an official candidate species, there is currently no legal federal obligation to avoid affecting the habitat of the species. However, the New England cottontail is state-listed as an endangered species by the New Hampshire Department of Fish and Game (NHDF&G), and we suggest that you contact the NHDF&G for further guidance.Seabrook Station Unit 1 Page C-9 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence Michael O'Keefe 2 May 15, 2009 New England cottontails are considered habitat specialists, insofar as they are dependent on early-successional habitats typically described as thickets.

In addition to New England cottontails demonstrating a strong affinity for heavy cover, they are also reluctant to stray from it (>5 m).Habitats of this type are typically associated with beaver flowage wetlands, idle agricultural lands, power line corridors, railroad right-of-ways, and patches of regenerating forests. In contrast, eastern cottontails (which can often be found living with New England cottontails) appear to have relatively generalized habitat requirements and can often be found in residential-type habitats, such as private lawns, golf courses, and active agriculture areas.Vegetation management along utility right-of-ways has a significant impact on the New England cottontail.

In fact, there is strong evidence that take of New England cottontails has occurred as a result of powerline right-of-way management.

Long-term management that converts scrub-shrub corridors into herbaceous covers serves to eliminate habitat and hinder dispersal, while short-term management of shrubs serves as a temporary impact to habitat. These short-term impacts to shrub vegetation are necessary to ensure that successional forces do not proceed to the point where habitat is no longer suitable for the New England cottontail.

Given the conservation status of this species, a full federal listing in the future is probable.

As such, it may be beneficial to begin a discussion about how your company could manage habitat for this species.This concludes our review of listed species and critical habitat in the project locations and environs referenced above. No further Endangered Species Act coordination of this type is necessary for a period of one year from the date of this letter, unless additional information on listed or proposed species becomes available.

In order to curtail the need to contact this office in the future for updated lists of federally-listed or proposed threatened or endangered species and critical habitats, please visit the Endangered Species Consultation page on the New England Field Office's website: , www.fws.gov/northeast/newenglandfieldoffice/EndangeredSpec-Consiltation.htm In addition, there is a link to procedures that may allow you to conclude if habitat for a listed species is present in the project area. If no habitat exists, then no federally-listed species are present in the project area and there is no need to contact us for further consultation.

If the above conclusion cannot be reached, further consultation with this office is advised. Information describing the nature and location of the proposed activity that should be provided to us for further informal consultation can be found at the above-referenced site.Seabrook Station Unit 1 Page C-10 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence Michael O'Keefe May 15, 2009 3 Thank you for your coordination.

Please contact Anthony Tur at 603-223-2541 to discuss management of the.transmission corridors and their impacts to the New England cottontail, or if we can be of further assistance.

Sincerely yours, Eric L. Derleth Acting Supervisor New England Field Office Seabrook Station Unit 1 License Renewal Application Page C-11 Appendix E -Environmental Report Attachment C Special Status, Species Correspondence FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-70M0 April 14, 2009 SBK-L-09048 National Marine Fisheries Service Protected Resources Division One Blackburn Drive Gloucester, MA 01930 Attn: Mary Colligan Assistant Regional Administrator Seabrook Station Request for Information on Threatened or Endangered Species FPL Energy Seabrook, LLC (FPL Energy Seabrook), the owner of a controlling interest in and the operator of Seabrook Station plans to apply to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the Operating License for 20 years beyond the current expiration date.The current NRC Operating License for Seabrook Station expires at midnight on March 15, 2030. FPL Energy Seabrook plans to submit its application to the NRC in the second quarter of 2010.FPL Energy Seabrook is contacting the New National Marine Fisheries Service in order to obtain input regarding issues that may need to be addressed in the Seabrook Station license renewal environmental reports, and to help identify any information that would be helpful to expedite consultation with the NRC in the future, if necessary.

The NRC requires that the license renewal application for Seabrook Station include environmental reports describing potential environmental impacts from refurbishment necessary for license renewal and from continued operations of the site and its associated transmission corridors during the renewal term. Transmission corridors from Seabrook extend into Massachusetts.

One of these potential environmental impacts would be the potential effect caused by activities specifically related to license renewal on threatened or endangered species located on the Seabrook Station site and its immediate environs, regardless of ownership or control of the land. Accordingly, the NRC requires that the environmental report for each license renewal application assess such a potential effect in accordance with the Endangered Species Act (10 CFR 51.53). Later, during its review of the proposed license renewals pursuant an FPL Group company Seabrook Station Unit 1 License Renewal Application Page C-12 Appendix E -Environmental Report Attachment C Special Status Species Correspondence National Marine Fisheries Service Page 2 to the National Environmental Policy Act (NEPA), the NRC will use that assessment to evaluate whether a basis exists to request consultation with your office under Section 7 of the Endangered Species Act.Seabrook Station is located within Rockingham County, in the town of Seabrook, New Hampshire on the western shore of Hampton Harbor, approximately two miles west of the Atlantic Ocean (Figure 1). The site is bounded on the north, east and south by estuarine marshlands, veined with man-made ditches and tidal creeks. Over 400 acres of the site property are marshland and the majority of the remaining upland has been developed as part of the station.The upland component is generally low quality for wildlife and is not an important natural resource area.Three transmission lines operating at 345 kV were constructed to deliver Seabrook Station's electrical output to the New England 345 kV transmission grid (Figure 2). These lines run through a variety of common natural and man-influenced habitats in New Hampshire and Massachusetts.

These transmission corridors are considered by the NRC to be within the scope of its environmental reviews for the Seabrook license renewal. These transmission corridors are owned and maintained by Public Service Company of New Hampshire (PSNH) and National Grid (NGRID). The first line runs north 17 miles (27.4 km) from Seabrook Station to Newington Station, located in Newington, NH. Immediately north of Seabrook Station, this line crosses the salt marsh on a previously existing rail bed, generally following the 1-95 corridor thereafter.

A second line runs west then south for approximately 30 miles (47.9 km) to the Scobie Pond Substation in Londonderry, NH. A third line extends approximately 39 miles (63.2 km) south and southwest from Seabrook Station to the Tewksbury Substation, in Tewksbury, MA.Based on a review of information available on the New Hampshire Natural Heritage Program website (town records of rare species and natural communities), information provided by the Massachusetts Natural heritage and Endangered Species Program, and previous on-site surveys, FPL Energy Seabrook believes that no federal or state-listed threatened or endangered plant or animal species resides on the Seabrook Station site. However, some state-listed threatened terrestrial animal species have potential to occur within Rockingham County and the counties crossed by the transmission corridors (see Table 1), and these species may occasionally migrate through the sites. Also, Atlantic Sturgeon, Shortnose Sturgeon and five species of federally-listed sea turtles may occur offshore in the Atlantic Ocean near the Seabrook Station site.Seabrook Station has a once-through heat dissipation system that withdraws water from the western Gulf of Maine through three offshore, submerged intake structures located approximately

1.3 miles

(2.1 kin) offshore in about 60 feet (18.3 m) of water (Figure 3)..The three intake structures are approximately 110 feet (33.5 m) apart and each has a 9-10 foot (2.7-3.0 m) inside diameter vertical intake shaft. A submerged concrete structure is mounted on the top of each structure to minimize fish entrapment by reducing the intake velocity to 0.5 ft per second. These intakes were modified in 1999 with additional vertical bars to prevent the intake of marine mammals.A single Atlantic sturgeon was captured near Seabrook prior to 1987, during site gill-net monitoring, Seabrook Station Unit 1 Page C-13 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence National Marine Fisheries Service Page 3 Although five sea turtle species could occur in this portion of the Atlantic, none have been reported near Seabrook or its intake/discharge structures nor are they likely to be entrapped at the intakes given the low intake rates and the presence of vertical bars on the intake structure.

FPL Energy Seabrook does not expect Seabrook Station operation during the license renewal term (an additional 20 years) to adversely affect threatened or endangered species at the station site, the immediate environs, or the transmission line corridors because license renewal will not alter existing operations.

No expansion of existing facilities is planned, and no structural modifications or other refurbishments have been identified that are necessary to support license renewal. Public Service Company of New Hampshire and National Grid have established management procedures for transmission lines that involve minimal disturbance of land, wetlands, and streams and are unlikely to adversely affect any threatened or endangered species.After review of the information provided in this letter, FPL Energy Seabrook would appreciate a letter detailing any concerns the National Marine Fisheries Service may have about any listed species or critical habitat in the area of the Seabrook Station site and the associated transmission corridors, or alternatively, confirming our conclusion that operation of Seabrook over the license renewal terms would have no effect on any threatened or endangered species. FPL Energy Seabrook will include copies of this letter and your response in the environmental reports that will be submitted to the NRC as part of the Seabrook Station license renewal application.

Letters detailing any concerns would be appreciated by June 30, 2009 to support the current submittal schedule.If you have any questions regarding this information, please contact me, at (603) 773-7745.Thank you in advance for your assistance.

Sincerely yours, Michael O'Keefe Licensing Manager

Enclosure:

Figure 1 -Location of Seabrook Station Figure 2 -Transmission lines associated with Seabrook Figure 3 -Diagram of Intake and Discharge Systems Table I -Endangered and Threatened Species Recorded in Rockingham County and Counties Crossed by Transmission Lines Seabrook Station Unit 1 Page C-14 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence Seabrook Station Unit 1 License Renewal Application Page C-15 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Legend A Substation

--c 345 kW Transmission Une maInterstate

= Primary Road Seabr'ook Station~Staft Bouindary () County Boundary Water m Urban Are Crane Pond WMA Fish and Wildlife Service N 4+Figure 2 Transmission Lines Associated with the Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-16 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Intake Shafts adStructuzres DISCHARGE TUNNEL AND SHAFTS Seabrook Plant Site Figure 3 Cooling Water Intake/Discharge Structures for Seabrook Station Nuclear Power Plant Drawings not to scale Seabrook Station Unit 1 License Renewal Application Page C-17 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Table 1. Endangered and Threatened Species Recorded in Rockingham County and Counties*

Crossed by Transmission Lines.Federal State Species Common Name Status** Status**Birds Charadrius melodus Falco peregrinus Haliaeetus leucocephalus Sterna dougallii Verrivora chrysoptera Fish Acipenser brevirostrum Acipenser oxyrynchus Mammals Sylvilagus transitionalis Plants Aristida purpurascens Carex bullata Carex striata var. brevis Carex trichocarpa Celtis occidentalis Cyperus engelmannii Gaylussacia dumosa Gentianopsis crinita Hottonia inflata Houstonia Iongifolia Hypoxis hirsuta Iris prismatica Isotria meleoloides Lespedeza virginica Liatris scariosa var. novae-angliae Prunus americana Platanthera flava var. herbiola Sparganium eurycarpum Sporobolus cryptandrus Triosteum aurantiacum Viola pedata Reptiles Caretta caretta Chelonia mydas Clemmys guttata Coluber constrictor Dermochelys coriacea Emydoidea blandingii Eretmochelys imbricata Heterodon platyhinos Lepidochelys kempii Piping plover Peregrine falcon Bald eagle Roseate tern Golden-winged warbler Shortnose sturgeon Atlantic sturgeon New England cottontail Purple needlegrass Inflated sedge Walter's sedge Hairy-fruited edge Hackberry Engelmann's Umbrella-sedge Dwarf huckleberry Fringed gentian Featherfoil Long-leaved bluets Hairy stargrass Slender blue flag Small-whorled pogonia Slender bush-clover Northern blazing star American plum Pale green orchid Large bur-reed Sand dropseed Orange horse-gentian Bird's-foot violet Loggerhead sea turtle Green sea turtle Spotted turtle Black racer Leatherback sea turtle Blanding's turtle Hawksbill sea turtle Eastern hognose snake Kemp's ridley sea turtle NHE, NHT NHT NHE, MAE MAE NHE, MAE MAE NHE MAT NHE NHE NHE NHT MAT NHT NHT NHE NHE NHE NHT NHE NHE NHE NHT NHT NHT NHE NHT MAT MAT NHT NHT MAE NHE, MAE MAE NHE MAE*Essex and Middlesex Counties in Massachusetts.

• • Status:

E=federal endangered, T=federal threatened, C=federal candidate, MAE=Massachusetts endangered, MAT=Massachusetts threatened, NHE=New Hampshire endangered, NHT=New Hampshire threatened, and Not listed.Seabrook Station Unit 1 License Renewal Application Page C-18 Appendix E -Environmental Report Attachment C Special Status Species Correspondence 0 FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7000 April 13,2009 SBK-L-09047 New Hampshire Department of Resources and Economic Development Division of Forests and Lands New Hampshire Natural Heritage Bureau 172 Pembroke Road P.O. Box 1856 Concord, NH 03301-1856 Attn: Melissa Coppola Environmental Information Specialist Seabrook Station Request for Information on Threatened or Endangered Species FPL Energy Seabrook, LLC (FPL Energy Seabrook), the owner of a controlling interest in and the operator of Seabrook Station plans to apply to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the Operating License for 20 years beyond the current expiration date.The current NRC Operating License for Seabrook Station expires at midnight on March 15, 2030. FPL Energy Seabrook plans to submit its application to the NRC in the second quarter of 2010.FPL Energy Seabrook is contacting the New Hampshire Natural Heritage Bureau in order to obtain input regarding issues that may need to be addressed in the Seabrook Station license renewal environmental reports, and to help identify any information that would be helpful to expedite consultation with the NRC in the future, if necessary.

The NRC requires that the license renewal application for Seabrook Station include environmental reports describing potential environmental impacts from refurbishment necessary for license renewal and from continued operations of the site and its associated transmission corridors during the renewal term. One of these potential environmental impacts would be the potential effect caused by activities specifically related to license renewal on threatened or endangered species located on the Seabrook Station site and its immediate environs, regardless an FPL Group company Seabrook Station Unit 1 License Renewal Application Page C-19 Appendix E -Environmental Report Attachment C Special Status Species Correspondence N.H. Department of Resources and Economic Development Page 2 of ownership or control of the land. Accordingly, the NRC requires that the environmental report for each license renewal application assess such a potential effect in accordance with the Endangered Species Act (10 CFR 51.53). Later, during its review of the proposed license renewals pursuant to the National Environmental Policy Act (NEPA), the NRC will use that assessment to evaluate whether a basis exists to request consultation with your office under Section 7 of the Endangered Species Act.Seabrook Station is located in the town of Seabrook, New Hampshire on the western shore of Hampton Harbor, approximately two miles west of the Atlantic Ocean (Figure 1). The site is bounded on the north, east and south by estuarine marshlands, veined with man-made ditches and tidal creeks. Over 400 acres of the site property are marshland and the majority of the remaining upland has been developed as part of the station. The upland component is generally low quality for wildlife and is not an important natural resource area.Three transmission lines operating at 345 kV were constructed to deliver Seabrook Station's electrical output to the New England 345 kV transmission grid (Figure 2). These lines run through a variety of common natural and man-influenced habitats in New Hampshire and Massachusetts.

These transmission corridors are considered by the NRC to be within the scope of its environmental reviews for the Seabrook license renewal. These transmission corridors are owned and maintained by Public Service Company of New Hampshire (PSNH) and National Grid (NGRID). The first line runs north 17 miles (27.4 kin) from Seabrook Station to Newington Station, located in Newington, NH. Immediately north of Seabrook Station, this line crosses the salt marsh on a previously existing rail bed, generally following the 1-95 corridor thereafter.

A second line runs west then south for approximately 30 miles (47.9 krn) to the Scobie Pond Substation in Londonderry, NH. A third line extends approximately 39 miles (63.2 kin) south and southwest from Seabrook Station to the Tewksbury Substation, in Tewksbury, MA.Based on a review of information available on the New Hampshire Natural Heritage Program website (town records of rare species and natural communities), FPL Energy Seabrook believes there are four possible federally-protected terrestrial species within Rockingham County, which contains the Seabrook Station site and the New Hampshire component of transmission corridors:

New England Cottontail, Piping Plover, Roseate Tern, and Small Whorled Pogonia. Habitat for these species is not thought to occur at the site or along the transmission corridors, although it is possible that New England Cottontails may occur along portions of the corridors.

Some state-listed terrestrial animal species also have potential to occur in this county (see Table 1). Also, Atlantic Sturgeon, Shortnose Sturgeon, marine mammals and five species of federally-listed sea turtles may occur offshore in the Atlantic Ocean near the Seabrook Station site. FPL Energy Seabrook is contacting the National Oceanic and Atmospheric Administration

-National Marine Fisheries Service regarding these marine species.Seabrook Station has a once-through heat dissipation system that withdraws water from the western, Gulf of Maine through three offshore, submerged intake structures located approximately

1.3 miles

(2.1 kim) offshore in about 60 feet (18.3 m) of water (Figure 3). The three intake structures are approximately 110 feet (33.5 in) apart and each has a 9-10 foot (2.7-3.0 m) inside diameter vertical intake shaft. A submerged concrete structure is mounted on the top of each structure to minimize fish entrapment by reducing the intake velocity to 0.5 ft per Seabrook Station Unit 1 Page C-20 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence N.H. Department of Resources and Economic Development Page 3 second. These intakes were modified in 1999 with additional vertical bars to prevent the intake of marine mammals.A single Atlantic Sturgeon was captured near Seabrook prior to 1987, during site gill-net monitoring.

Although five sea turtle species could occur in this portion of the Atlantic, none have been reported near Seabrook or its intake/discharge structures nor are they likely to be entrapped at the intakes given the low intake rates given the low intake rates and the presence of vertical bars on the intake structure.

FPL Energy Seabrook does not expect Seabrook Station operation during the license renewal term (an additional 20 years) to adversely affect threatened or endangered species at the station site, the immediate environs, or the transmission line corridors because license renewal will not alter existing operations.

No expansion of existing facilities is planned, and no structural modifications or other refurbishments.have been identified that are necessary to support license renewal. Public Service Company of New Hampshire has established management procedures for transmission lines within New Hampshire that involve minimal disturbance of land, wetlands, and streams and are unlikely to adversely affect any threatened or endangered species.After review of the information provided in this letter, FPL Energy Seabrook would appreciate a letter detailing any concerns the New Hampshire Natural Heritage Bureau may have about any listed species or critical habitat in the area of the Seabrook Station site and the associated transmission corridors, or alternatively, confirming our conclusion that operation of Seabrook over the license renewal terms would have no effect on any threatened or endangered species.FPL Energy Seabrook will include copies of this letter and your response in the environmental reports that will be submitted to the NRC as part of the Seabrook license renewal application.

Letters detailing any concerns would be appreciated by June 30, 2009 to support the current submittal schedule.If you have any questions regarding this information, please contact me, at (603) 773-7745.Thank you in advance for your assistance.

Sincerely yours, Michael O'Keefe Licensing Manager

Enclosure:

Figure 1 -Location of Seabrook Station Figure 2 -Transmission lines associated with Seabrook Figure 3- Diagram of Intake and Discharge Systems Table I -Endangered and Threatened Species Recorded in Rockingham County and Counties Crossed by Transmission Lines Seabrook Station Unit 1 Page C-21 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence Legend 6 S.MO1d C1b1s 6-MI. Rachm.-__ Prno.y Road-Seoond.,y

.. COO...c60 Road u n.Bndo..S..abwok S~taton loparolty Boundary-Urban Am..N 0 0.5 1 2 Figure 1 General Location of Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-22 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Legend A Substation 345 kV Trnsmlsslon Line m interstate

= Primary Road Seabrook Station SState Bounidary 1 County Boundary m Urban Area Crane Pond WMA Fish and Wildlife Service N+0 1 2 4 6 Figure 2 Transmission Lines Associated with the Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-23 Appendix E -Environmental Report Attachment C Special Status Species Correspondence DISCHARGE TUNNEL AND SHAFTS Seabrook Plant Site Figure 3 Cooling Water Intake/Discharge Structures for Seabrook Station Nuclear Power Plant Drawings not to scale Seabrook Station Unit 1 License Renewal Application Page C-24 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Table 1. Endangered and Threatened Species Recorded in Rockingham County and Counties*

Crossed by Transmission Lines.Federal State Species Common Name Status** Status**Birds Charadrius melodus Falco peregrinus Haliaeetus leucocephalus Sterna dougallii Vermivora chrysoptera Fish Acipenser brevirostrum Acipenser oxyrynchus Mammals Sylvilagus transitionalis Plants Aristida purpurascens Carex bullata Carex striata var. brevis Carex trichocarpa Celtis occidentalis Cyperus engelmannii Gaylussacia dumosa Gentianopsis crinita Hottonia inflata Houstonia Iongifolia Hypoxis hirsuta Iris prismatica Isotria meleoloides Lespedeza virginica Liatris scariosa var. novae-angliae Prunus americana Platanthera flava var. herbiola Sparganium eurycarpum Sporobolus cryptandrus Triosteum aurantiacum Viola pedata Reptiles Caretta caretta Chelonia mydas Clemmys guttata Coluber constrictor Dermochelys coriacea Emydoidea blandingii Eretmochelys imbricata Heterodon platyhinos Lepidochelys kempii Piping plover Peregrine falcon Bald eagle Roseate tern Golden-winged warbler Shortnose sturgeon Atlantic sturgeon New England cottontail Purple needlegrass Inflated sedge Walter's sedge Hairy-fruited edge Hackberry Engelmann's Umbrella-sedge Dwarf huckleberry Fringed gentian Featherfoil Long-leaved bluets Hairy stargrass Slender blue flag Small-whorled pogonia Slender bush-clover Northern blazing star American plum Pale green orchid Large bur-reed Sand dropseed Orange horse-gentian Bird's-foot violet Loggerhead sea turtle Green sea turtle Spotted turtle Black racer Leatherback sea turtle Blanding's turtle Hawksbill sea turtle Eastern hognose snake Kemp's ridley sea turtle NHE, NHT NHT NHE, MAE MAE NHE, MAE MAE NHE MAT NHE NHE NHE NHT MAT NHT NHT NHE NHE NHE NHT NHE NHE NHE NHT NHT NHT NHE NHT MAT MAT NHT NHT MAE NHE, MAE MAE NHE MAE T T E E E*Essex and Middlesex Counties in Massachusetts.

• • Status:

E=federal endangered, T=federal threatened, C=federal candidate, MAE=Massachusetts endangered, MAT=Massachusetts threatened, NHE=New Hampshire endangered, NHT=New Hampshire threatened, and Not listed.Seabrook Station Unit 1 License Renewal Application Page C-25 I"cl r- CD CD W Cn 0 CD00 CD C,.D Memo NH NATURAL HERrrAGE BUREAU"> To: Michael O'Keefe"5 NextEra Energy Seabrook, LLC S-. PO Box 300 Seabrook, NH 03874 -0 From: Melissa Coppola, NH jNatural Heritage Bureau Y,-'. -Date: 3/18/2009 (valid for one year from this date)Re: Review by NH Natural Heritage Bureau -.NHB File ID: NHB09-0508

-- -' -Town Seabrook, Hamrpton, North Hampton, Greenland Project type: --Railroads, Transmission

lines, Location.

powerim R OW-Seabrook.Station cc: Kim Tuttle :Tasisoln

~ ~ti As requested, I have searched our database for records dfrare specses and exemplary natural with the following results. 3 CD Comments:

NHB will need to be contacted when projects occur within the R-O-W. This nemo i for licenase renewal only. ý, 'i Natural Community

.-S tate' Fede ral Notes .' , '-.Atlantic white cedar -yello, birch -peppethush C-h -a nChages to the hydrologyo wetland are the greatest lffreat facing the cedar U/)swamp ---swamp. Damming which cie pooling for extended peiods can flood and drown "0 Brackish marsh s -existingtries, and drainage thai rsults in lower water levels can lead to invasion by ">High salt marsh -.-otherseies that can out compete -and eventually eli ate -Atlantic white cedar o-Low salt marsh --tesiIreed nutrient inputifrnm stormwater runoff could also deleteriously 7 CD CD impact this acidic, low-nutrientplant community.

Poor level fen/bog system -Level fens are stagnant, and as such are characteriied by low nutrient levels, -rlatývely high acidity levels, and accumulations ofpeat. The primary threats to this m, X community are changes to its hydrology (especially that which causes pooling), (n r increcsed nutrient input from storrmwater rmioff, and sedimentation from nearby CD Re ape-sestiefrnsam*-disturance.

0.-.-Red maple -sensitive fern swamp* Theaeswamps are influenced by groundwater seepage and springs which moderate (n-water fluctuations and maintainýconditions favorable for the accumulation of organic 0 '-matter., The primary,threits-'are changes to the hydrology of the wetland complex, --,-paeicularly~raisingr-lowering the water levels, and increased nutrient and pollutant CD CD input carried in by stormwater runoff. ( "-3 0)0 C Department of Resources and Economic Development DRED/NHB V "0 Division of Forests and Lands PO Box 1856 0 0 (603)271-2214 fax: 271-6488 Concord NH 03302-1856 CD -I CD CD 0 CD (1 0NH HE'RI'AOE BUREAU> Saline/brackish intertidal flat --Threats to these conmumties, are primarily alterations to the hydrology of the wetland" Saline/brackish subtidal channel/bay bottom -- -(such as ditching or tidal restrictions that might affect the sheet flow of tidal waters across the intertidal flat) and increýaed.input of nutrients and pollutants in storm' runoff.0Swamp white oak floodplain forest --Threats are primarily-changes to te hydrology of the river, land conversion and Temperate minor river floodplain systman -- -fragmentation, introduction of invasive speciesand increased input of nutrients and pollutants.

3 , l2ýTidal creek bottom .Threatsto tese co iesare primarily alterations to water level or flow regimes, and icreased input of ntrients iian pollutants in storm runoff Plant apecies *-State `Feder'al.

ANote,53 Dwarf Glasswort (Salicornia bigelovii)* .E'-Thregtaýeprimari.altertionsto the hydrology of the'%etland, such as ditching or Woody Glasswort (Sarcocoriaperennis)

E tidirstiiosthai' tafctese ofl tdal wters across the intertidal flat, ac.ivit. that"eliminae pl ant and i a injiut of nutrients and pollutants in 0 storm runlm (e .2 Tall Wormwood (Artemuslacampestris ssp. ' T -T M This spcies grows in-dry dune systems and is sensitive to°disturbances that eliminate CD caudata) it.s habitat or disturb the naturldynamics of the dune area., Vertebrate species State Federal

-Common Tern (Sterna hirnaido)*

T -'Contact the NH Fish & Ganie Dept (see below) 01c Golden-winged Warbler (Venmivora chrysoptera)*

--Contact the NH Fish & Ganre'D ept (see below). CD Osprey (Pandion hahaetua) 4, C thactle NH Fish & Gamen1ept (see below).Redfin Pickerel (Esox amenrcanus ameicanuas)

L- Contact te NH Fish & G 'te l .Spotted Turtle (Clemmys g .tata) ,T -Contactthe NH Fish & Game Dept (see below)Vesper~ Sppro (seeete below).s .....Vesper Sparrow (Pooecete gramines)

-Contact the NH Fish & Game Dept (see below)._-,`

'Codes: "E" = Endangered, "T = Threatenied,."-

.an eemplaiy natural community, or a rare species tracked by NH Natural Heritagethat has not yet been added to the official cn m state list An asterisk (*) indicates that the most recent report for that occurrence was morý than 20 years ago. V" CD Contact for all aninal reviews: Kim Tuttle, A'/HF&G, (603) 271-65 44. 0 " A negative result (no record in our database) does iot'mean that a sensitive sp *ie is not present Our data can only tell you of known occurrences, based on 0 information gathered by qualified biologists and reportedto our office. However, many areas have neveibeen surveyed, or have only been surveyed for certain --: species. For some purposes, including legal requirements for statew nd.perL sthe-fact that no'species ofconcem are known to be present is sufficient.

C 2 However, an on-site survey would provide better information on what i co-unIties are indeed present- @ D oni of what and Lands PO Boe p856 o .n CDX Department of Resources and Economic Development DRED/NHB -- V0 Division ofForests and Lands PO-Box 1856 0 0 4(603) 271-2214 fax: 271-6488 Concord NH 03302-1856 CD ;I

ow CD a)CD 00 0>__ C NH NATURAL HERITAGE BUREAU Known locations of rare species and exemplary natural communities" "- Note: Mapped locatlons are not always exact. Occurrences that are not In the vicinity of the project are not. shown, 0 SPotted'Tultle 0 2 (D Golden-wingd Warble rl-F-CD 02>S-0 UI CD n-.CDC h()0) 015 ) 0.5 10Me Histoical record a.oCD CD S-0 00 Ot300Valid for one year-from this dale: 18 Mar 2009 0D 0 0 S0~(n-CD 0 0 (DO 0)(0 NH NATURAL HERITAGEi BUREAU*Known locations of rar~e species and exemplary natura.I cqmmunities Note: Mapped locations are not:always exact. Occurrences that are not In the vicinity of the project are not shown.03 (D Cl)CD 0 >CD (0-.C)00 CD CD 0 0 CD I 1:2.=000 Vai.foono,yeariro~m.this date: *lBMar2009 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CP00000166"0051NH New Hampshire Natural Heritage Bureau -Community Record Atlantic white cedar -yellow birch -pepperbush swamp Legal Status Conservation Status Federal: Not listed Global: Not ranked (need more information)

State: Not listed State: Imperiled due to rarity or vulnerability Description at this Location Conservation Rank: Good quality, condition and lanscape context ('B' on a scale of A-D).Comments on Rank: Detailed

Description:

1996: No details. 1989: Has a healthy population of Chamaecyparis thyoides (Atlantic white cedar) plus Picea mariana (black spruce), Tsuga canadensis (hemlock), and Larix (larch).Excellent variety of bog plants.General Area: 1972: Bordered by two roads, forest land, and a railroad bed.General Comments:

Swamp logged in the past, but has since regained a natural quality. NH Natural Area #3. 335 acres total wetlands at Packer Bog.Management Comments: Location Survey Site Name: Packer Bog Managed By: Packer Bog County: Rockingham USGS quad(s): Portsmouth (4307017)Town(s): Greenland Lat, Long: 430149N, 0704851W Size: 359.6 acres Elevation:

30 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Greenland at Packer Bog.Dates documented First reported:

1972 Last reported:

1996-07-16 Nichols, Bill. 1996. Field survey to Packer Bog, Greenland on July 16.Nichols, B. & D. Sperduto.

1996. Ecological inventories of 1996 project areas on the White Mountain National Forest in New Hampshire.

New Hampshire Natural Heritage Program, Concord, NH. 83 pp.Seabrook Station Unit 1 Page C-30 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CE00000005

-012*NH New Hampshire Natural Heritage Bureau -Community Record Brackish marsh Legal Stat tus Federal: Not listed State: Not-listed Conservation Status Global: Not ranked (need more information)

State: Imperiled due to rarity or vulnerability Description at this Location Conservation Rank. Good quality, condition and lanscape context (B' on a scale of A-D).Comments on Rank: Rank is for largest area visited (Taylor River). Others were B- (three sites) or C (Seabrook Salt Marsh).Detailed

Description:

1997: A characteristic mix ofgraminoids includes Agrostisstalanifera var. palustris (marsh creeping bent-grass), Spartina patens (salt-meadow cord-grass), Juncus gerardii (salt marsh rush), Solidago sempervirens (seaside goldenrod), Distichlis spicata (spike-grass), Juncus arcticus var. littoralis (shore rush), Elytrigia repens (quack-grass), Spartinapectinata (fresh-water cord-grass, slough-grass), Carexpaleacea (chaffy salt sedge), Hierochloe odorata (sweet grass), Aster novi-belgii (New York aster), Scirpuspungens (three-square rush), and several other less frequent species. At the Seabrook School area, ephemeral runoff channel/stream entering from west; area dominated by Lythrum salicaria (purple loosestrife).

Small elevated knoll in middle with Quercus bicolor (swamp white oak), Toxicodendron radicans (climbing poison ivy), and Rosa virginiana (Virginia rose).General Area: 1997: The Blackwater

-Hampton River Estuary contains the majority of the estimated 6200 acres of salt marsh in the state. The Blackwater River portion of the estuary continues south into Salisbury, MA. The estuarine system extends seaward to an imaginary line drawn across Hampton Harbor Inlet and upstream and landward to where ocean-derived salts are less than or equal to 0.5 parts per thousand during the period of average annual low freshwater flow (Cowardin et al. 1979). This estuary is surrounded by moderate levels of residential and commercial development.

Several exemplary subtidal and intertidal communities occur in this estuary. Exemplary subtidal communities are tidal creek bottom and undifferentiated sallne'bracldsh subhtdal channel/bay bottom. Exemplary intertidal communities are brackish marsh, coastal shoreline strand/swale, sallne/brackdsh intertidal flat, and high and low salt marsh. Exemplary dry Appalachian oak-hickory forest occurs at the site as "salt marsh islands", forested uplands surrounded by salt marsh. Most of the estuary is unaffected by restricted tidal flow. Other areas are described as having an adequate tidal inlet by the USDA Soil Conservation Service (1994). The largest portions of the estuary determined to have inadequate tidal inlets include the Meadow Pond area, the Taylor River -Drakes River area west of the rail road track, and the Browns River west of the rail road track (USDA Soil Conservation Service 1994). In the last four years, several salt marsh restoration projects have begun in this estuary (Ammann, A.P. pers. comm., 1997).General Comments:

1997: Tidally flooded by salt water only during spring tides and storm surges. Supports a greater diversity of plants and generally flooded less frequently than the robust forb brackish marsh. Elevationally higher, received more freshwater input, and experienced less frequent tidal flooding than the high salt marsh. Occasionally occurs along the upper margins of the high salt marsh where sufficient fresh water runoffor groundwater discharge flows onto the marsh surface. This hydrologic regime supports brackish marsh species and other species most often found in fresh or salt marshes but tolerant of brackish conditions and able to successflhlly compete in this environment.

Management Comments: Location Survey Site Name: Hampton Harbor Managed By: ASNH to Properties, Inc. -Pelton County: Rocklngham USGS quad(s): Hampton (4207087)Seabrook Station Unit 1 License Renewal Application Page C-31 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NtOM9-0509 EOCODE: CE00000005*012*NH Town(s): Hampton Lat, Long: 425407N, 0704957W Size: 3448.9 acres Elevation:

5 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Large area more or less framed by Rte. I to the west, Rte. 101 to the north, Rte. IA to the east, and the Massachusetts state line to the south. 1997: Five areas visited. Wrights Island (park at Seabrook Sewage Treatment Plant), Farm Brook (drive to east end of Depot Road and park in lot), two areas at Seabrook School Salt Marsh (park behind the Seabrook Elementary/Middle School off of Walton Road), and Taylor River (along the northern portions of the Taylor River Estuary from Drakes Creek to Tide Mill Creek).Dates documented First reported:

1997-07-05 Last reported:

1997-10-06 Nichols, Bill. 1997. Field survey to Blackwater River Salt Marsh on July 5.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphire's Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-32 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHBO9.0508 EOCODE: CE0000004*34*NH New Hampshire Natural Heritage Bureau -Community Record High salt marsh Legal Status Conservation Status Federal: Not listed Global: Not ranked (need more information)

Slate: Not listed State: Rare or uncommon Description at this Location Conservation Rank: Excellent quality, condition and lanscape context CA! on a scale of A-D).Comments on Rank: These ranks are for the entire estuary.Detailed

Description:

2006: Community observed and photographed.

1997: In addition to Spartina patens (salt-meadow cord-grass) and Juncus gerardii (salt marsh rush), other common plants on the high marsh included smooth cord-grass (short form) and Distichlis spicata (spike-grass).

D.spicata formed pure stands in wetter, more poorly drained areas, or mixed with S. patens, growing at similar elevations on the high marsh. J. gerardil dominated landward of salt meadow-grass in narrow vegetative zones with decreased tidal flooding and soil water salinity, beginning at about mean spring high water. This zone had the highest species richness within the high marsh and included Solidago sempervirens (seaside goldenrod), Panicum virgatum (switch-grass), Hierochloe odorata (sweet grass), Carex hormathodes (necklace sedge), Festuca rubra (red fescue), Aster novl-belgil (New York aster), Elytrigia repens (quack-grass), Spartina pectinata (fresh-water cord-grass), and Potentilla anserina (silverweed).

General Area: 1997: At Hampton Harbor, the mean tidal range is 8.3 feet with spring tides averaging 9.5 feet. Here, the high marsh rises from ca. 4 feet above mean sea level at its lower end to 5 feet above mean sea level at the landward limit of the salt marsh rush zone. The Blackwater

-Hampton River Estuary contains the majority of the estimated 6200 acres of salt marsh in the state. The Blackwater River portion of the estuary continues south into Salisbury, MA. The estuarine system extends seaward to an imaginary line drawn across Hampton Harbor Inlet and upstream and landward to where ocean-derived salts are less than or equal to 0.5 parts per thousand during the period of average annual low freshwater flow (Cowardin et al.1979). This estuary is surrounded by moderate levels of residential and commercial development.

Several exemplary subtidal and intertidal communities occur in this estuary.Subtidal communities include the undifferentiated saline/brackish subtidal channel/bay bottom and tidal creek bottom. Other intertidal communities are brackish marsh, coastal shoreline strand/swale, saline/brackish intertldajflat, and low salt marsh. Exemplary dry Appalachian oak-hickory forest occurs at the site as "salt marsh islands", forested uplands sunrounded by salt marsh. Most of the estuary is unaffected by restricted tidal flow. Other areas are described as having an adequate tidal inlet by the USDA Soil Conservation Service (1994). The largest portions of the estuary determined to have inadequate tidal inlets include the Meadow Pond area, the Taylor River -Drakes River area west of the rail road track, and the Browns River west of the rail road track (USDA Soil Conservation Service 1994). In the last four years, several salt marsh restoration projects have begun in this estuary (Ammann, A.P. pers. comm., 1997).General Comments: Management 1997: Marsh ditched heavily; greenhead boxes present Comments: Location Survey Site Name: Hampton Harbor Managed By: ASNH to Properties, Inc. -Pelton County. Rockingham USGS quad(s): Hampton (4207087)Town(s): Hampton Lat, Long: 425407N, 0704957W Size: 3448.9 acres Elevation:

4 feet Seabrook Station Unit 1 Page C-33 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CE00000OD4'034*NH Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Large area more or less framed by Rte. I to the west, Rte. 101 to the north, Rte. IA to the east, and the Massachusetts state line to the south. Occurs behind barrier beaches, along inland bays, and other areas protected from high-energy wave action.Dates documented First reported:

1997-07-05 Last reported:

2006-08-17 Kimball, Ben and Pete Bowman. 2006. Field survey to The Sands on August 17.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphire's Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-34 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CEODODO003*035*NH New Hampshire Natural Heritage Bureau -Community Record Low salt marsh Legal Status Federal: Not listed State: Not listed Conservation Status Global: Not ranked (need more information)

State: Rare or uncommon Description at this Location Conservation Ranki Excellent quality, condition and lanscape context CA' on a scale of A-D).Comments on Rank: These ranks are for the entire estuary.Detailed

Description:

General Area: General Comments: Management Comments: 1997: No details.1997: The Blackwater

-Hampton River Estuary contains the majority of the estimated 6200 acres of salt marsh in the state. The Blackwater River portion of the estuary continues south into Salisbury, MA. The estuarine system extends seaward to an imaginary line drawn across Hampton Harbor Inlet and upstream and landward to where ocean-derived salts are less than or equal to 0.5 parts per thousand during the period of average annual low freshwater flow (Cowardin et al. 1979). This estuary is surrounded by moderate levels ofresidential and commercial development Several exemplary subtidal and intertidal communities occur in this estuary. Subtidal communities include the undifferentiated saline/brackish subtdal channel/bay bottom and tidal creek bottom. Other intertidal communities are brackish marsh, coastal shoreline strandLswale, saline/brackish intertidal flat, and high salt marsh.Exemplary dry Appalachian oak-hickory forest occurs at the site as "salt marsh islands", forested uplands surrounded by salt marsh. Most of the estuary is unaffected by restricted tidal flow. Other areas are described as having an adequate tidal inlet by the USDA Soil Conservation Service (1994). The largest portions of the estuary determined to have inadequate tidal inlets include the Meadow Pond area, the Taylor River -Drakes River area west of the rail road track, and the Browns River west of the rail road track (USDA Soil Conservation Service 1994). In the last four years, several salt marsh restoration projects have begun in this estuary (Ammann, A.P. pers. comm., 1997).Location Survey Site Name: Hampton Harbor Managed By: ASNH to Properties, Inc. -Pelton County: Rockingham Town(s): Hampton Size: 3448.9 acres USGS quad(s): Hampton (4207087)Lat, Long: 425407N, 0704957W Elevation:

4 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Large area more or less framed by Rte. I to the west, Rte. 101 to the north, Rte. IA to the east, and the Massachusetts state line to the south. Occurs behind barrier beaches, along inland bays, and other areas protected from high-energy wave action.Dates documented First reported:

1997-07-05 Last reported:

1997-10-08 Nichols, Bill. 1997. Field survey to Blackwater River Salt Marsh on July 5.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphire's Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-35 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: EPO0000002*028*NH New Hampshire Natural Heritage Bureau -System Record Poor level fen/bog system Legal Status Conservation Status Federal: Not listed Global: Not ranked (need more information)

State: Not listed State: Rare or uncommon Description at this Location Conservation Rank: Fair quality, condition and/or lanscape context ('C on a scale of A-D).Comments on Rank: Detailed

Description:

1992: Population of Gaylussacia dumosa var bigeloviana was found in the fen community.

General Area: he classic fen sequence of floating mat, open peat, low heath, tall heath, dwarf spruce and larch, and shrub swamp is found in this wetland complex. The lag varies from 20 to over 200 feet wide, although the low and high heath zones are not always well developed.

The dominant plant in the low heath where the dwarf huckleberry was found was leatherleaf.

Dwarf black spruce and larch are scattered throughout this zone. The shrub swamp further back from the pond is dominated by mountain holly, winterberry holly, and high bush blueberry.

General Comments: Management Comments: Location Survey Site Name: Lower Shields Pond Managed By: County: Rockingham Town(s): Derry Size: 41.8 acres USGS quad(s): Derry (4207183)Lat, Long: 425503N, 0711927W Elevation:

380 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Take Rte 28BYP north from Derry Village traffic circle ca 2 miles to Shields Pond Road on the right. Go ca. 0.5 mile to culverted creek. There is a path beyond the powerlines that you hike to from the west side of the stream.Dates docume First reported: nted 1992-09-11 Last reported:

1992-09-11 Royte, Josh and John Lortie. 1992. Field survey to Lower Shields Pond on September 11.Seabrook Station Unit 1 License Renewal Application Page C-36 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CP00000094014-KH New Hampshire Natural Heritage Bureau -Community Record Red maple -sensitive fern swamp Legal Status Conservation Status Federal: Not listed Global: Not ranked (need more information).

State: Not listed State: Imperiled due to rarity or vulnerability Description at this Location Conservation Rank: Historical records only -current condition unknown.Comments on Rank: Detailed

Description:

1987: Large swamp with mature characteristic vegetation.

Acer rubrum (red maple)dominates with a nearly uniform Lindera benzoin (northern spicebush) shrub layer. A variety of plants occur in pools (Callapalustrir (wild calla), Carex lacustris (lake sedge)) and on hummocks (Rsbuspubescens (dwarf raspberry), Copris trifolia var. groenlandica (goldthread)).

General Area: 1987: A seepage swamp at headwaters of small drainage with well-defined and mature vegetation structure.

General Comments:

1987: Powerline crosses swamp. Some cutting has been done.Management Comments: Location Survey Site Name: Powwow Pond, SE of Managed By: County: Rockingham USGS quad(s): Kingston (4207181)Town(s): East Kingston Lat, Long: 425357N, 0710114W Size: 39.2 acres Elevation:

120 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Seepage swamp southeast of Powwow Pond. At powerline right-of-wayjust south ofjunction of Rte.107A and Rte. 108.Dates documented First reported:

1987 Last reported: Korpi, John. 1987. Field survey to Powwow Pond Swamp of 22 July.1987-07-22 Seabrook Station Unit 1 License Renewal Application Page C-37 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CEOOOOOI1 036*NH New Hampshire Natural Heritage Bureau -Community Record Saline/brackish intertidal flat Legal Status Federal: Not listed State: Not listed Conservation Status Global: Not ranked (need more information)

State: Rare or uncommon Description at this Location Conservation Rank. Excellent quality, condition and lanscape context CA! on a scale of A-D).Comments on Rank: Ranks are for an area at Seabrook School Salt Marsh.Detailed

Description:

General Area: General Comments: Management Comments: 1997: No details.1997: The Blackwater

-Hampton River Estuary contains the majority of the estimated 6200 acres of salt marsh in the state. The Blackwater River portion of the estuary continues south into Salisbury, MA. The estuarine system extends seaward to an imaginary line drawn across Hampton Harbor Inlet and upstream and landward to where ocean-derived salts are less than or equal to 0.5 parts per thousand during the period of average annual low freshwater flow (Cowardin et al. 1979). This estuary is surrounded by moderate levels ofresidential and commercial development Several exemplary subtidal and intertidal communities occur in this estuary. Subtidal communities include the undifferentiated saline/brackish subtidal channel/bay bottom and tidal creek bottom. Other intertidal communities are brackish marsh, coastal shoreline strand/swale, and high and low salt marsh. Exemplary dry Appalachian oak-hickory forest occurs at the site as "salt marsh islands", forested uplands surrounded by salt marsh. Most of the estuaryis unaffected by restricted tidal flow. Other areas are described as having an adequate tidal inlet by the USDA Soil Conservation Service (1994). The largest portions of the estuary determined to have inadequate tidal inlets include the Meadow Pond area, the Taylor River -Drakes River area west of the rail road track, and the Browns River west of the rail road track (USDA Soil Conservation Service 1994). In the last four years, several salt marsh restoration projects have begun in this estuary (Ammann, A.P. pers. comm., 1997).1997: Extensive areas of this community type were found within the Blackwater

-Hampton River Estuary. Intertidal sand and mud flats are gently sloping, sparsely vegetated, habitats.The substrate, exposed completely at extra low spring tide, ranges in composition from sands to muds and silts. Benthic diatoms and other microalgae occurring in this environment are important contributors to the primary productivity of the total estuarine system (Sickiey 1989). Macroalgae is typically uncommon across the exposed substrate.

Characteristic invertebrates found in New Hampshire's intertidal mudflats include polychacte worms (including Nereis virens, Nephtys caeca, Clymenella tortquata, and Scoloplos spp.) and mollusks (including soft-shelled clam [Mya arenaria], Baltic Macoma [Macoma balthica], gem shell [Gemma gemma], and swamp Hydrobia [Hydrobia minuta]) (NAI 1973).Arthropods are also well represented and include green crabs (Carcinus maenus), rock crabs (Cancer irroratus), flat-clawed hermit crabs (Pagurus pollicaris), and horseshoe crabs (Limulus polyphemis).

During the diurnal (twice daily) tidal flooding several species of fish and other aquatic species feed on the benthos and epibenthic algae. This community also provides important foraging habitat for shorebirds and other animals when the intertidal flat is exposed. The diverse variety of primary foods (microalgae, phytoplankton, and detritus)available to consumers supports the high productivity found on intertidal flats. The substrate is composed of sand or silt and clay rich in organic matter. Vascular plants are sparse to more typically absent.Location Survey Site Name: Managed By: Hampton Harbor Hampton Beach State Park Seabrook Station Unit 1 License Renewal Application Page C-38 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NB059-0508 EOCODE: CEOOOOII0 1*36*NH County: Rockingham USGS quad(s): Hampton (4207087)Town(s): Hampton Lat, Long: 425405N, 0704917W Size: 1183.7 acres Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Large areamore or less framed by Rte. I to the west, Rte. 101 to the north, Rte. IA to the east, and the Massachusetts state line to the south. Occurs between estuarine marshes or other coastal communities landward and subtidal communities seaward and includes tidal creek channels exposed at low tide.Dates documented First reported:

1997-07-05 Last reported.

1997-10-08 Nichols, Bill. 1997. Field survey to Blackwater River Salt Marsh on July 5.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphire's Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-39 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 BOCODE: CE00000012-038*NH New Hampshire Natural Heritage Bureau -Community Record Saline/brackish subtldal channel/bay bottom Legal Status Federal: Not listed State: Not listed Conservation Status Global: Not ranked (need more information)

State: Rare or uncommon Description at this Location Conservation Rank: Excellent quality, condition and lanscape context CA! on a scale of A-D).Comments on Rank: Ranks are for an area at Seabrook School Salt Marsh.Detailed

Description:

General Area: General Comments: Management Comments: 1997: No details.1997: The Blackwater

-Hampton River Estuary contains the majority of the estimated 6200 acres of salt marsh in the state. The Blackwater River portion of the estuary continues south into Salisbury, MA. The estuarine system extends seaward to an imaginary line drawn across Hampton Harbor Inlet and upstream and landward to where ocean-derived salts are less than or equal to 0.5 parts per thousand during the period of average annual low freshwater flow (Cowardin et al. 1979). This estuary is surrounded by moderate levels of residential and commercial developmenm Several exemplary subtidal and intertidal communities occur in this estuary. Another subtidal community is tida creek bottom. Intertidal communities are brackish marsh, coastal shoreline strand'swale, salinelbrackish intertidaiflat, and high and low salt marsh. Exemplary dry Appalachian oak-hickory forest occurs at the site as "salt marsh islands", forested uplands surrounded by salt marsh. Most of the estuary is unaffected by restricted tidal flow. Other areas are described as having an adequate tidal inlet by the USDA Soil Conservation Service (1994). The largest portions of the estuary determined to have inadequate tidal inlets include the Meadow Pond area, the Taylor River -Drakes River area west of the rail road track, and the Browns River west of the rail road track (USDA Soil Conservation Service 1994). In the last four years, several salt marsh restoration projects have begun in this estuary (Ahimann, A.P. pers. comm., 1997).1997: These communities perform important ecological functions including supporting fish populations, providing refuge for fish and invertebrates that retreat from intertidal flats and estuarine marshes at low tide, and serving as a spawning and nursery area for numerous species of aquatic animals (Short 1992). Salinities in coastal areas remain close to 30 ppt year-round (Short 1992). Substrates varied at different locations and included mud, sand, gravel, cobble, or rock. Vascular plants were typically absent or sparse. Seaweeds are an important component of this habitat and the surrounding environment.

Location Survey Site Name: Hampton Harbor Managed By: Hampton Beach State Park County: Rockingham Town(s): Hampton Size: 1183.7 acres USGS quad(s): Hampton (4207087)Lat, Long: 425405N, 0704917W Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Large area more or less framed by Rte. 1 to the west, Rte. 101 to the north, Rte. IA to the east, and the Massachusetts state line to the south. Occurs in permanently flooded saline tidal channels and bays.Dates docume First reported: nted mted 1997-07-05 Last reported:

1997-10-08 Seabrook Station Unit 1 License Renewal Application Page C-40 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE:' CE00000012-038-NH Nichols, Bill. 1997. Field survey to Blackwater River Salt Marsh on July 5.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphire's Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-41 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CT00500226-001NH New Hampshire Natural Heritage Bureau -Community Record Swamp white oak floodplain forest Legal Status Federal: Not listed State: Not listed Conservation Status Global: Not ranked (need more information)

State: Critically imperiled due to rarity or vulnerability Description at this Location Conservation Rank. Excellent quality, condition and lanscape context CA' on a scale of A-D).Comments on Rank: Detailed

Description:

1998: The low terrace floodplain forest is dominated by Quercus bicolor (swamp white oak),.Acer rubrum (red maple), and Carya ovata (shagbark hickory), with Fraxinus americana (white ash) and L77mus americana (American elm) in the understory.

Onoclea sensibilis (sensitive fern) and Osmunda cinnamomea (cinnamon fern) are dominant in the herb layer.The terrace sits distinctly lower than the surrounding landscape (by 2-4 meters) and buffers the meandering river course. Vines and shrub species (e.g. Toxicodendron radicans (climbing poison ivy), Viburnum lentago (nannyberry), and Viburnum dentatum var. lucidum (northern arrowwood))

fill in natural gaps and edges. Soils are not particularly enriched (pH=5.2), but they are dark, very fine sandy lnams that may have some coastal influence (i.e.silt from marine sedimentation).

A fair amount of dead wood was scattered throughout the floodplain, with a large recent blowdown oak adjacent to the observation plot River is entrenched by 1-2 meters within a steep silty bank, yet flooding and depositional processes appear to be active, with some meanders cutting more deeply, and others about to be cut off.Microtopographic variation is slight on this mostly fiat terrace.General Area: 1998: Housing and other development appear to encroach from all sides, but not actually into the low terrace. The wetland complex seems to be fairly large and wide, but above the flooded zone, there appears to be considerable human disturbance and fragmentation.

Just downstream of the surveyed area, the Richard Sargent Management area provides a buffer along and upslope of the floodplain.

General Comments:

1998: From aerial photographs, the low terrace floodplain forest appears to extend well beyond the surveyed property.

This is an excellent example of swamp white oak floodplain, but landowner patterns and development may threaten its integrity over the long term.Management 1998: Monitor landowner patterns and adjacent fragmentation Comments: Location Survey Site Name: Powwow River Managed By:. Welch Parcel County: Rockingham Town(s): East Kingston Size: 193.3 acres USGS quad(s): Kingston (4207181)Lat, Long: 425357N, 0710038W Elevation:

80 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

From Kingston, take Rte. 107A south to Rte. 108 south in East Kingston.

Turn left into CWR Timber Management and Realty dirt driveway/timber yard. Park and hike east on logging roads to floodplain terrace. An alternate route is to access the natural community directly from Chase Rd. at Smith Comer.Dates documented First reported:

1998-09-02 Last reported:

1998-09-02 Bechtel, Doug. 1998. Field survey to Powwow River on September 2.Seabrook Station Unit 1 License Renewal Application Page C-42 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NM09-0508 EOCODE: CT00000226*001*NH Nichols, William F., Daniel D. Sperduto, Douglas A. Bechtel, and Katherine F. Crowley. 2000. Floodplain Forest Natural Communities along Minor Rivers and Large Streams in New Hampshire.

Prepared by NH Natural Heritage.Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-43 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 ECOODE: EROO000003*026*NH New Hampshire Natural Heritage Bureau -System Record Temperate minor river floodplain system Legal Status Conservation Status Federal: Not listed Global: Not ranked (need more information)

State: Not listed State:' Not ranked (need more information)

Description at this Location Conservation Rank: Historical records only -current condition unknown.Comments on Rank. Unique coastal plain river with large exemplary wetland.Detailed

Description:

1986: Dominated by Acer rubrum and Quercus bicolor (dominant only on coastal plain in NH) w/some Carya ovata (shagbark hickory).

Vines abound; Toxicodendron radicans (poison ivy), Smilax rotundifolia (bullbrier), Vitis spp. (grape). Dense vegetation, swamp extends to regularly inundated alluvial areas.General Area: 1986: Narrow river that drains large area in flat coastal plain area; seems to result in frequent flooding of narrow, swampy floodplain.

General Comments:

1986: Historic station for Lygodium palmatum (climbing fern); swamp has very dense physiognomy, natural & undisturbed.

Management Comments: Location Survey Site Name: Pow Wow River Managed By: Welch Parcel County: Rockingham USGS quad(s): Exeter (4207088)Town(s): East Kingston Lat, Long: 425357N, 0710038W Size: 191.7 acres Elevation:

95 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Pow Wow River. SW comer of Exeter quad. Along river west of Chase Road.Dates documented First reported:

1986 Last reported:

1986-06-23 Korpi, J. and F. Brackley.

1986. Field survey to Chase Hill on August 4.Seabrook Station Unit 1 License Renewal Application Page C-44 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: CE00000014"037"NH New Hampshire Natural Heritage Bureau -Community Record Tidal creek bottom Legal Status Conservation Status Federal: Not listed Global: Not ranked (need more information)

State: Not listed State: Rare or uncommon Description at this Location Conservation Rank: Excellent quality, condition and lanscape context CA' on a scale of A-D).Comments on Rank: Ranks are for an area at Seabrook School Salt Marsh.Detailed

Description:

1997: The substrate was composed of mud rich in organic matter. Vascular plants were sparse but included Ruppia maritima (widgeon-grass).

General Area: 1997: The Blackwater

-Hampton River Estuary contains the majority of the estimated 6200 acres of salt marsh in the state. The Blackwater River portion of the estuary continues south into Salisbury, MA. The estuarine system extends seaward to an imaginary line drawn across Hampton Harbor Inlet and upstream and landward to where ocean-derived salts are less than or equal to 0.5 parts per thousand during the period of average annual low freshwater flow (Cowardin et al 1979). This estuary is surrounded by moderate levels of residential and commercial development Several exemplary subtidal and intertidal communities occur in this estuary. Another subtidal community is the undifferentiated saline/bracklsh subtidal channet/bay bottom. Intertidal communities are brackish marsh, coastal shoreline strand/swale, saline'brackish intertidalflat, and high and low salt marsh. Exemplary dry Appalachian oak-hickory forest occurs at the site as "salt marsh islands", forested uplands surrounded by salt marsh. Most of the estuary is unaffected by restricted tidal flow. Other areas are described as having an adequate tidal inlet by the USDA Soil Conservation Service (1994). The largest portions of the estuary determined to have inadequate tidal inlets include the Meadow Pond area, the Taylor River -Drakes River area west of the rail road track, and the Browns River west of the rail road track (USDA Soil Conservation Service 1994). In the last four years, several salt marsh restoration projects have begun in this estuary (Ammann, A.P. pers. comm., 1997).General Comments:

1997: Tidal creeks provide habitat for stickleback (Pungitius pungitius, Gasterosteuas aculeatus, and Apeltes quadracuns), mummichog (Fundulus heteroclitus), and several other species offish (Short 1992) and foraging ground for migratory and year round bird species and other animals. As the salt marsh replaces acereting intertidal flats seaward, tidal creeks develop along former intertidal flat drainage channels.

Landward, as the high salt marsh develops above mean high water, tidal flooding frequency decreases, reducing drainage flow in the creeks. This tends to cause the upstream end of the tidal creek to fill in as sediment deposition occurs at a greater rate than erosion (Redfield 1972). The banks of tidal creeks were nearly vertical and often slump, supporting a narrow band of Spartina alterniflora (smooth cord-grass) (see low salt marsh description).

Management Comments: Location Survey Site Name: Hampton Harbor Managed By: Hampton Beach State Park County: Rockingham Town(s): Hampton Size: 1183.7 acres USGS quad(s): Hampton (4207087)Lat, Long: 425405N, 0704917W Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Large area more or less framed by Rte. I to the west, Rte. 101 to the north, Rte. IA to the east, and the Massachusetts state line to the south. Occurs in permanently flooded creek-bottoms draining Seabrook Station Unit 1 License Renewal Application Page C-45 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NMB09-0508 EOCODE: CE50550014*037*NH water from the high and low salt marsh into the main channel or bay.Dates documented First reported:

1997-07-05 Last reported:

1997-10-08 Nichols, Bill. 1997. Field survey to Blackwater River Salt Marsh on July 5.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphires Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-46 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE* PDCHEOJ040*002NH New Hampshire Natural Heritage Bureau -Plant Record Dwarf Glasswort (Salicornia bigelovis)

Legal Status Conservation Status Federal: Not listed Global: Demonstrably widespread, abundant, and secure State: Listed Endangered State: Critically imperiled due to rarity or vulnerability Description at this Location Conservation Rank: Historical records only -current condition unknown.Comments on Rank: Sub-population of a large "A-" population.

Detailed

Description:

1982:25 or more plants in 5x2 area directly east ofSalicornia virginica.

Plants just starting to flower.General Area: Flat, full sun, damp but above main area of inundated marsh with Salicornia virgiica.General Comments: Management Comments: Location Survey Site Name: RR Tracks Managed By: Landing + Vicinity Marsh County: Rockingham USGS quad(s): Hampton (4207087)Town(s): Hampton Falls Lat, Long: 425437N, 0705110W Size: 2.8 acres Elevation:

10 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Hampton Falls. RR tracks site.drive to east end of Depot Rd. Go south along RR tracks to Hampton Falls River. Site on west side of RR tracks just north of Hampton Falls River.Dates documented First reported:

1982 Last reported.

1982-08-17 Dunlop, Deb. New England College, Botany Department, Box 30, Henniker, NH 03242. 603/428-2233.

Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphires Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-47 Appendix E -Environmental Report Attachment C Special Status Species Correspondence N5B09-0508 EOCODE: PDASTOSOD7*007-NH New Hampshire Natural Heritage Bureau -Plant Record Tail Wormwood (Artemisla campestris ssp. caudata)Legal Status Conservation Status Federal: Not listed Global: Demonstrably widespread, abundant, and secure State: Listed Threatened State: Imperiled due to rarity or vulnerability Description at this Location Conservation Rank: Not ranked Comments on Rank: Detailed

Description:

1997: Common (11-50 plants) on railroad tracks leading down to salt marsh to east. 1982: Numerous plants scattered along railroad bed on both sides. Specimens at NHA, NEBC (1916, 1982).General Area: 1997: Open habitat on railroad banks.General Comments: Management Comments: Location Survey Site Name: Hampton Falls River Managed By: ASNH Hampton Falls Saltmarsh

-Swain County: Rockingham USGS quad(s): Hampton (4207087)Town(s): Hampton Falls Lat, Long: 425449N, 0705102W Size: 2.8 acres Elevation:

10 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Railroad tracks, north of Hampton Falls River in Hampton Harbor salt marsh.Dates documented First reported:

1916 Last reported:

1997-09-19 Nichols, Bill. 1997. Field survey to Hampton Falls River Salt Marsh on September 19.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphire's Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NIL Seabrook Station Unit 1 Page C-48 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: PDCHEOM030*O04*NH New Hampshire Natural Heritage Bureau -Plant Record Woody Glasswort (Sarcocornia perennis)Legal Status Conservation Status Federal: Not listed Global: Demonstrably widespread, abundant, and secure State: Listed Endangered State: Not ranked (need more information)

Description at this Location Conservation Rank. Fair quality, condition and/or lanscape context ('C' on a scale of A-D).Comments on Rank: Detailed

Description:

1997: At least two large mats in a 5-10 square-meter area. 1982: 50 or more stalks in 15x10 foot area, plants just starting to flower. Plants appear vigorous.General Area: 1997: Gulf of Maine Salt Marsh. 1982: Flat, wet; full sun, with Spartinapatens (salt-meadow cord-grass).

Salt Marsh.General Comments: Management Comments: Location Survey Site Name: Hampton Falls River Managed By: Landing + Vicinity Marsh County: Rockingham USGS quad(s): Hampton (4207087)Town(s): Hampton Falls Lat, Long: 425437N, 0705110W Size: 2.8 acres Elevation:

10 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Hampton Falls. "Birmins" [Brimers?]

Salt Marsh. Take Depot Ave to railroad tracks, go south on tracks 1/8 mile. Plants on west side of tracks at base of banking in salt marsh.Dates documented First reported:

1982-08-17 Last reported:

1997-09-19 Nichols, Bill. 1997. Field survey to Hampton Falls River Salt Marsh on September 19.Nichols, William F. 2000. Ecological Assessment of Selected Towns in New Hamphires Coastal Zone. Prepared by NH Natural Heritage Inventory.

Concord, NH.Seabrook Station Unit 1 License Renewal Application Page C-49 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: ABNNMO070-005-NH New Hampshire Natural Heritage Bureau -Animal Record Common Tern (Sterna hirundo)Legal Status Conservation Status Federal: Not listed Global: Demonstrably widespread, abundant, and secure State: Listed Threatened State: Critically imperiled due to rarity or vulnerability Description at this Location Conservation Rank. Historical records only -current condition unknown.Comments on Rank: 2007: No records from this site since 1978.Detailed

Description:

1978: At least 2 nests. 1969: 10 adults, I chick observed.

1966: Ca. 10 birds present, I nest with 2 eggs.1964:

10 birds nesting.General Area.General Comments: Management Comments: Location Survey Site Name: Hampton Fails RR Station Managed By: Former Dodge Marsh County: Rockingham USGS quad(s): Hampton (4207087)Town(s): Hampton Falls Lat, Long: 425444N, 0705105W Size: 2.8 acres Elevation:

5 feet Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Hampton Falls Railroad station, Route I, then East on Depot Ave.Dates documented First reported:

1964 Last reported:

1978 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at 11 Hazen Drive, Concord, NH 03301 or at (603) 271-2461.Seabrook Station Unit 1 License Renewal Application Page C-50 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: ABPBX01030*001*NH New Hampshire Natural Heritage Bureau -Animal Record Golden-winged Warbler (Vermivora chrysoptera)

Legal Status Conservation Status Federal: Not listed Global: Apparently secure but with cause for concern State: Not listed State: Not ranked (need more information)

Description at this Location Conservation Rank: Historical records only -current condition unknown.Comments on Rank: Detailed

Description:

1986: 1 adult female seen (Obs id 1634).General Aream 1986: Terrestrial

-Scrub / shrubland (Obs id 1634).General Comments:

1986: Female observed carrying food to undisclosed nest location in old clear cut (Obs-id 1634).Management Comments: Location Survey Site Name: Chair Hill Managed By: Brookside Wildlife Sanctuary County: Rockingham USGS quad(s): Exeter (4207088)Town(s): South Hampton Lat, Long: 425329N, 0705641W Size: 30.8 acres Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

1986: South of Peak Road at south side of Brookside Wildlife Sanctuary (ASNH). [Off of Woodman Rd., north of Chair Hill.] (Obs id 1634).Dates documented First reported:

1986-06-04 Last reported:

1986-06-04 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at II Hazen Drive, Concord, NH 03301 or at (603) 271-2461.Seabrook Station Unit 1 License Renewal Application Page C-51 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB309-0508 EOCODE: ABPBX01030*003*NH New Hampshire Natural Heritage Bureau -Animal Record Golden-winged Warbler (Vermivora chrysoptera)

Legal Status Federal: Not listed State: Not listed Conservation Status Global: Apparently secure but with cause for concern State: Not ranked (need more information)

Description at this Location Conservation Rank: Historical records only -current condition unknown.Comments on Rank: Detailed

Description:

1994: 1 adult male (Ohs id 1944). 1984: 1 male, I female (Obsid 1944). 1982: 1 male (Obs.id 1944). 1981: 1 male (Ohs id 1944). 1980: 1 male (Obs id 1944).General Area. 1994: Terrestrial

-Scrub / shrubland (Obs-id 1944).General Comments: Management Comments: Location Survey Site Name: Horse Hill, SW of Managed By: County: Rockingham USGS quad(s): Exeter (4207088)Town(s): Kensington Lat, Long: 425427N, 0705618W Size: 6.4 acres Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

1994: South Road (Rt 107) residence (Obs id 1944).Dates documented First reported:

1984-07-01 Last reported:

1984-07-01 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at I I Hazen Drive, Concord, NH 03301 or at (603) 271-2461.Seabrook Station Unit 1 License Renewal Application Page C-52 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-0508 EOCODE: ABNKCOIOIO154*NH New Hampshire Natural Heritage Bureau -Animal Record Osprey (Pandion haliaetus)

Legal Status Conservation Status Federal: Not listed Global: Demonstrably widespread, abundant, and secure State: Not listed State: Not ranked (need more information)

Description at this Location Conservation Rank: Not ranked Comments on Rank: Detailed

Description:

2006: Brookside Sanctuary.

1 fledged.General Area.General Comments: Management Comments: Location Survey SiteName:

Brookside Sanctuary Managed By: Crosby County- Rockingham Town(s): South Hampton Size: .4 acres USGS quad(s): Exeter (4207088)Lat, Long: 425348N, 0705648W Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

From Towles Comer, go W on Highland Rd. ca. 0.6 miles and turn left onto Woodman Rd. Follow ca. 0.3 miles to the crossing of the Back River. Nest is ca. 0.3 miles NE along the Back River.Dates docunme First reported: nted ented 2006 Last reported:

2006 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at 11 Hazen Drive, Concord, NH 03301 or at (603) 271-246 1.Seabrook Station Unit 1 License Renewal Application Page C-53 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHBB9-0508 EOCODE: AFCHDB1011001NH New Hampshire Natural Heritage Bureau -Animal Record Redfin Pickerel (Esax americanus americanus)

Legal Status Federal: Not listed State: Not listed Conservation Status Global: Demonstrably widespread, abundant, and secure State: Apparently secure but with cause for concern Description at this Location Conservation Rankc Not ranked Comments on Rank: Detailed

Description:

2006: Area 11491: 2 adults, sex unknown caught in bag seine.2004:

Area 4563: 7+ adult, sex unknown, 3+ immature, sex unknown.General Area: 2006: Area 11491: Freshwater stream. Very shallow water upstream of long unpaved driveway.

Small wetland/stream flows under driveway through small culvert 2004: Area 4563: Freshwater stream.General Comments:

2006: Area 11491: NHFGD fish survey. 2004: Area 4563: They are a common species here--in wetlands in & adjacent to the TNC designated Horse Hill Seepage Swamp-Registered Natural Area. (Obs.id 1906).Management Comments: Location Survey Site Name: Horse Hill Swamp Managed By: KLC County: Rockingham Town(s): Kensington Size: 4.3 acres USGS quad(s): Exeter (4207088)Lat, Long: 425433N, 0705623W Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

2006: Area 11491: Intermittent steam crossing long driveway (mailbox #217), north of Rte. 107 and directly aeross from Highland Road. 2004: Area 4563: Winkley Brook & associated ponds, marshes, swamps. Gavutis (residence) property.

Rte. 107 (231 South Rd.) ca. 0.7mi. west of the junction with Rte. 150. South of Cottage Hill and west of Horse Hill.Dat es documented First reported: 2004-03-05 Last reported:

2006-06-26 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at I Hazen Drive, Concord, NH 03301 or at (603) 271-2461.Seabrook Station Unit 1 License Renewal Application Page C-54 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHBD9-0508 EOCODE: ABPBX95010*007*NH New Hampshire Natural Heritage Bureau -Animal Record Vesper Sparrow (Pooecetes gramineus) us Conservation Status Legal Stat Federal: Not listed State: Not listed Global: Demonstrably widespread, abundant, and secure State: Not ranked (need more information)

Description at this Location Conservation Rank: Not ranked Comments on Rank: Detailed

Description:

2001:10 seen, age and sex unknowns (Obs-id 1190).General Area: 2001: Habitat not clear -birds in powerline corridor so probably a mix of open areas and shrubs (Obs id 1190).General Comments:

2001: Total of 10 birds includes some presumed to be juveniles, but exact breakdown of adults and young was not made by the observer (Obs-id 1190).Management Comments: Location Survey Site Name: Cobum Hill, Powerlines West of Managed By- Danville Town Forest County: Rockingham Town(s): Danville Size: 84.1 acres USGS quad(s): Sandown (4207182)Lat, Long: 425624N, 0710810W Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

2001: Powerlines near Ticker Town Road (class 6). [From intersection of Sandown Rd. travel the powerlines southwest to junction of 2 more powerlines.

Go southwest, past wetland area about 1.1 miles.] (Obs id 1190).Dates docume First reported: nted 2001-07-24 Last reported:

2001-07-24 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at II Hazen Drive, Concord, NH 03301 or at (603) 271-2461.Seabrook Station Unit 1 License Renewal Application Page C-55 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHB09-.0508 EOCODE: ABPBX9501001 I'NH New Hampshire Natural Heritage Bureau -Animal Record Vesper Sparrow (Pooecetes gramineus)

Legal Status Conservation Status Federal: Not listed Global: Demonstrably widespread, abundant, and secure State: Not listed State: Not ranked (need more information)

Description at this Location Conservation Rank: Historical records only -current condition unknown.Comments on Rank: Detailed Deseription:

1983: 2 adult males, I adult, sex unknown, seen and beard (Obs id 1235).General Area: 1983: Terrestrial

-grasatand

/ field (Obs id 1235).General Comments:

1983: One bird carrying food, indicating dependant young in vicinity.

Species also present in this location in 1981 and 1982 (Obs-id 1235).Management

-Comments: Location Survey Site Name: Hog Hill, north of Managed By: County: Rockingham USGS quad(s): Exeter (4207088)Town(s): Kensington Lat, Long: 425436N, 0705819W Size: 84.1 acres Elevation:

Precision:

Within (but not necessarily restricted to) the area indicated on the map.Directions:

Hog Hill, west end of Bartlett Road. [Off of Rte. 107 near the Kensington/East Kingston town line.](Obshid 1235).Dates docume First reported: nted nted 1983-06-14 Last reported:

1983-06-14 The New Hampshire Fish & Game Department has jurisdiction over rare wildlife in New Hampshire.

Please contact them at I I Hazen Drive, Concord, NH 03301 or at (603) 271-2461.Seabrook Station Unit 1 License Renewal Application Page C-56 Appendix E -Environmental Report Attachment C Special Status Species Correspondence EOCODE: Legal Status Conservation Status Federal: Global: State: State: Description at this Location Conservation Rank: Comments on Rank: Detailed

Description:

General Area: General Comments: Management Comments: Location Survey Site Name: Managed By: County- USGS quad(s): Town(s): Lat, Long: Size: Elevation:

Precision:

Directions:

Dates documented First reported:

Last reported: Seabrook Station Unit 1 License Renewal Application Page C-57 Appendix E -Environmental Report Attachment C Special Status Species Correspondence EOCODE: Legal Status Conservation Status Federal: Global: State: State: Description at this Location Conservation Rank: Comments on Rank.Detailed

Description:

General Area: General Comments: Management Comments: Location Survey Site Name: Managed By: County: USGS quad(s): Town(s): Lat, Long: Size: Elevation:

Precision:

Directions:

Dates documented First reported:

Last reported: Seabrook Station Unit 1 License Renewal Application Page C-58 Attachment C Appendix E -Environmental Report Special Status Species Correspondence 0 FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7000 April 13, 2009 SBK-L-09046 Natural Heritage and Endangered Species Program Attn: Regulatory Review Massachusetts Division of Fisheries

& Wildlife North Drive Westborough, MA 01581 Attn: Emily Holt Endangered Species Review Assistant Seabrook Station Transmission Corridors Request for Information on Threatened or Endangered Species FPL Energy Seabrook, LLC (FPL Energy Seabrook), the owner of a controlling interest in and the operator of Seabrook Station plans to apply to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the Operating License for 20 years beyond the current expiration date.The current NRC Operating License for Seabrook Station expires at midnight on March 15, 2030. FPLE Seabrook plans to submit its application to the NRC in the second quarter of 2010.FPL Energy Seabrook is contacting the Massachusetts Division of Fisheries and Wildlife in order to obtain input regarding issues that may need to be addressed in the Seabrook Station license renewal environmental reports, and to help identify any information that would be helpful to expedite consultation with the NRC in the future, if necessary.

The NRC requires that the license renewal application for Seabrook Station include environmental reports describing potential environmental impacts from refurbishment necessary for license renewal and from continued operations of the site and its associated transmission corridors during the renewal term. Transmission corridors from Seabrook extend into Massachusetts.

One of these potential environmental impacts would be the potential effect caused by activities specifically related to license renewal on threatened or endangered species located on the Seabrook Station site and its immediate environs, regardless of ownership or an FPL Group company Seabrook Station Unit 1 License Renewal Application Page C-59 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Natural Heritage and Endangered Species Program Page 2 control of the land. Accordingly, the NRC requires that the environmental report for each license renewal application assess such a potential effect in accordance with the Endangered Species Act (10 CFR 51.53). Later, during its review of the proposed license renewals pursuant to the National Environmental Policy Act (NEPA), the NRC will use that assessment to evaluate whether a basis exists to request consultation with your office under Section 7 of the Endangered Species Act.Seabrook Station is located within an 889-acre parcel of property in the town of Seabrook, New Hampshire owned by FPLE Seabrook.

The existing operating license for Seabrook Station Unit I was initially issued for a 40-year term that expires in 2030. License renewal would extend the operating period for the reactor by 20 years beyond the expiration of its existing license.Seabrook Station is on the western shore of Hampton Harbor, approximately two miles west of the Atlantic Ocean (Figure 1). Three transmission lines operating at 345 kV were constructed to deliver Seabrook Station's electrical output to the New England 345 kV transmission grid (Figure 2). These lines run through a variety of common natural and man-influenced habitats in New Hampshire and Massachusetts.

These transmission corridors are considered by the NRC to be within the scope of its environmental reviews for the Seabrook license renewal. These transmission corridors are owned and maintained by Public Service Company of New Hampshire (PSNH) and National Grid (NGR!D). The first line runs north 17 miles (27.4 km) from Seabrook Station to Newington Station, located in Newington, NH. Immediately north of Seabrook Station, this line crosses the salt marsh on a previously existing rail bed, generally following the 1-95 corridor thereafter.

A second line runs west then south for approximately 30 miles (47.9 kim)to the Scobie Pond Substation in Londonderry, NH. A third line extends approximately 39 miles (63.2 kIn) south and southwest from Seabrook Station to the Tewksbury Substation, in Tewksbury, MA.Based on a review of information available on the Massachusetts Natural Heritage Program website, FPL Energy Seabrook believes there are four possible federally-protected terrestrial species within Essex and Middlesex Counties, which contain the Massachusetts component of transmission corridors:

New England Cottontail, Piping Plover, Roseate Tern, and Small Whorled Pogonia. Habitat for these species is not thought to occur along the transmission corridors, although it is possible that NE cottontails may occur along portions of the corridors.

Some state-listed terrestrial animal species also have potential to occur within these counties (see Table 1). Also, Atlantic Sturgeon, Shortnose Sturgeon, marine mammals and five species of federally-listed sea turtles may occur offshore in the Atlantic Ocean near the Seabrook site. FPL Energy Seabrook is contacting the National Oceanic and Atmospheric Administration

-National Marine Fisheries Service regarding these marine species.FPL Energy Seabrook does not expect Seabrook Station operation during the license renewal term (an additional 20 years) to adversely affect threatened or endangered species at the station site, the immediate environs, or the transmission line corridors because license renewal will not alter existing operations.

No expansion of existing facilities is planned, and no structural modifications or other refurbishments have been identified that are necessary to support license Seabrook Station Unit 1 Page C-60 License Renewal Application Appendix E -Environmental Report Attachment C Special Status Species Correspondence Natural Heritage and Endangered Species Program Page 3 renewal. Public Service Company of New Hampshire and National Grid have established management procedures for transmission lines that involve minimal disturbance of land, wetlands, and streams and are unlikely to adversely affect any threatened or endangered species.After review of the information provided in this letter, FPL Energy Seabrook would appreciate a letter detailing any concerns the Division of Fisheries and Wildlife may have about any listed species or critical habitat in the area of the transmission corridors, or alternatively, confirming our conclusion that operation of Seabrook Station over the license renewal term would have no effect on any threatened or endangered species. FPL Energy Seabrook will include copies of this letter and your response in the environmental reports that will be submitted to the NRC as part of the Seabrook Station license renewal application.

Letters detailing any concerns would be appreciated by June 30, 2009 to support the current submittal schedule.If you have any questions regarding this information, please contact me, at (603) 773-7745.Thank you in advance for your assistance.

Sincerely yours, Licensing Manager

Enclosure:

Figure 1 -Location of Seabrook Station Figure 2 -Transmission lines associated with Seabrook Table I -Endangered and Threatened Species Recorded in Rockingham County and Counties Crossed by Transmission Lines Seabrook Station Unit 1 License Renewal Application Page C-61 Attachment C Appendix E -Environmental Report Special Status Species Correspondence D6-MI* Radio.-Pd-r.y Road 8Seabrook S~.bon Pr~opery Boundary U rban A-.Figure 1 General Location of Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-62 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Legend A Substation-lr 345 kV Transmission ULn Interstate Primary Road iSeabrook Station~State Bounidary 1M County Boundary Water-Urban Area Crane Pond WMA Fish and Wildlife Service N 0 1 2 4 6 Fm -,:;m l!ý -IMe Figure 2 Transmission Lines Associated with the Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page C-63 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Table 1. Endangered and Threatened Species Recorded in Rockingham County and Counties*

Crossed by Transmission Lines.Federal State Species Common Name Status"* Status**Birds Charadrius melodus Falco peregnnus Haliaeetus leucocephalus Sterna dougallii Vermivora chrysoptera Fish Acipenser brevirostrum Acipenser oxyrynchus Mammals Sylvilagus transitionalis Plants Aristida purpurascens Carex bullata Carex striata var. brevis Carex trichocarpa Celtis occidentalis Cyperus engelmannii Gaylussacia dumosa Gentianopsis crinita Hottonia inflata Houstonia Iongifolia Hypoxis hirsuta Iris prismatica Isotria meleoloides Lespedeza virginica Liatris scariosa var. novae-angliae Prunus americana Platanthera flava var. herbiola Sparganium eurycarpum Sporobolus cryptandrus Triosteum aurantiacum Viola pedata Reptiles Caretta caretta Chelonia mydas Clemmys guttata Coluber constrictor Dermochelys coriacea Emydoidea blandingii Eretmochelys imbricata Heterodon platyhinos Lepidochelys kempii Piping plover Peregrine falcon Bald eagle Roseate tern Golden-winged warbler Shortnose sturgeon Atlantic sturgeon New England cottontail Purple needlegrass Inflated sedge Walter's sedge Hairy-fruited edge Hackberry Engelmann's Umbrella-sedge Dwarf huckleberry Fringed gentian Featherfoil Long-leaved bluets Hairy stargrass Slender blue flag Small-whorled pogonia Slender bush-clover Northern blazing star American plum Pale green orchid Large bur-reed Sand dropseed Orange horse-gentian Bird's-foot violet Loggerhead sea turtle Green sea turtle Spotted turtle Black racer Leatherback sea turtle Blanding's turtle Hawksbill sea turtle Eastern hognose snake Kemp's ridley sea turtle T E E C C NHE, NHT NHT NHE, MAE MAE NHE, MAE MAE NHE MAT NHE NHE NHE NHT MAT NHT NHT NHE NHE NHE NHT NHE NHE NHE NHT NHT NHT NHE NHT MAT MAT NHT NHT MAE NHE, MAE MAE NHE MAE*Essex and Middlesex Counties in Massachusetts.

• • Status:

E=federal endangered, T=federal threatened, C=federal candidate, MAE=Massachusetts endangered, MAT=Massachusetts threatened, NHE=New Hampshire endangered, NHT=New Hampshire threatened, and Not listed.Seabrook Station Unit 1 License Renewal Application Page C-64 Appendix E -Environmental Report Attachment C Special Status Species Correspondence Co,,monweahlh of Maachusetu Division of TIMA Fisheries

& Wildlife IasWildiife Michael O'Keefe FPL Energy Seabrook Station PO Box 300 Seabrook NH 03874 RE: Project Location: Town: NHESP Tracking No.: RECEIVED JUN 15 2009 M.D. O'Keefe Wayne F. MacCallum, Director 6/11/2009 Transmission Lines associated with the Seabrook Station Nuclear Power Plant TEWKSBURY, AMESBURY, MERRIMAC, WEST NEWBURY, GROVELAND, GEORGETOWN, BOXFORD, HAVERHILL, METHUEN, DRACUT, ANDOVER 09-26515 To Whom It May Concern: Thank you for contacting the Natural Heritage and Endangered Species Program ("NHESP".)

of the MA Division of Fisheries

& Wildlife for information regarding state-listed rare species in the vicinity of the above referenced site. Please note that I have returned the check submitted by Normandeau Associates because we received two requests and two fees for this site.Based on the information provided, portions of the transmission lines are located within Priority Habitat and Estimated Habitat as indicated in the Massachusetts Natural Heritage Atlas (13th Edition).

Our database indicates that the following state-listed rare species have been found in the vicinity of the site: Amesbury Priority Habitat 967 (PH 967) and Estimated Habitat 798 (EH 798)Scientific name Common Name Taxonomic Group Ligumia nasuta Eastern Pondmussel Mussel Merrimac Priority Habitat 1321 (PH 1321) and Estimated Habitat 65 (EH 65)Scientific name Common Name Taxonomic Group Haliaeetus leucocephalus Bald Eagle Bird Acipenser brevirostrum Shortnose Sturgeon Fish West Newbury Priority Habitat 1321 (PH 1321) and Estimated Habitat 65 (EH 65)Scientific name Common Name Taxonomic Group Haliaeetus leucocephalus Bald Eagle Bird Acipenser brevirostrum Shortnose Sturgeon Fish West Newbury Priority Habitat 875 (PH 875) and Estimated Habitat 698 (EH 698)Scientific name Common Name Taxonomic Group Somatochlora georgiana Coppery Emerald Dragonfly State Status Special Concern State Status Endangered Endangered State Status Endangered Endangered State Status Endangeredma rvWilhflifo nr Division of Fisheries and Wildlife Field Headquarters, North Drive, Westborough, MA 01581 (508) 389-6300 Fax (508) 389-7891 An Agency of the Departmet of Fish and Came Seabrook Station Unit 1 License Renewal Application Page C-65 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHESP No. 09-26515, page 2 of 3 West Newbury Priority Habitat 1440 (PH 1440) and Estimated Habitat 46 (EH 46)Scientific name Common Name Taxonomic Group Emydaidea blandingii Blanding's Turtle Reptile Groveland Priority Habitat 1440 (PH 1440) and Estimated Habitat 46 (EH 46)Scientific name Common Name Taxonomic Group Emydoidea blandingii Blanding's Turtle Reptile Ambystoma laterale Blue-Spotted Salamander Amphibian Georgetown Priority Habitat 1440 (PH 1440) and Estimated Habitat 46 (EI 46)Scientific name Common Name Taxonomic Group Emydoidea blandingii Blanding's Turtle Reptile Glyptemys insculpta Wood Turtle Reptile Ambystoma laterale Blue-Spotted Salamander Amphibian Enallagma laterale New England Bluet Damselfly Boxford Priority Habitat 1440 (PH 46) and Estimated Habitat 1440 (Eli 46)Scientific name Common Name Taxonomic Group Emydoidea blandingii Blanding's Turtle Reptile Glyptemys insculpta Wood Turtle Reptile Ambystoma laterale Blue-Spotted Salamander Amphibian Haverhill Priority Habitat 1321 (PH 1321) and Estimated Habitat 65 (EH 65)Scientific name Common Name Taxonomic Group Haliseetus leucocephalus Bald Eagle Bird Neurocordulia obsoleta Umber Shadowdragon Dragonfly Stylurus spiniceps A Clubtail Dragonfly Dragonfly Gomphus vastus Cobra Clubtail Dragonfly Methuen Priority Habitat 1321 (PH 1321) and Estimated Habitat 65 (EH 65)Scientific name Common Name Taxonomic Group Haliaeetus leucocephalus Bald Eagle Bird Neurocordutia obsoleta Umber Shadowdragon Dragonfly Stylurus spiniceps A Clubtail Dragonfly Dragonfly Gomphus vastus Cobra Clubtail Dragonfly Glyptemys insculpta Wood Turtle Reptile Amb-jstoma laterale Blue-Spotted Salamander Amphibian Methuen Priority Habitat 249 (PH 249) and Estimated Habitat 135 (EH 135)Scientific name Common Name Taxonomic Group Emydoidea blandingii Blanding's Turtle Reptile State Status Threatened State Status Threatened Special Concern State Status Threatened Special Concern Special Concern Special Concern State Status Threatened Special Concern Special Concern State Status Endangered Special Concern Threatened Special Concern State Status Endangered Special Concern Threatened Special Concern Special Concern Special Concern State Status Threatened Seabrook Station Unit 1 License Renewal Application Page C-66 Appendix E -Environmental Report Attachment C Special Status Species Correspondence NHESP No, 09-26515, page 3 of 3 Methuen Priority Habitat 374 (PH 374) and Estimated Habitat 263 (EH 263)Scientific name Common Name Taxonomic Group Glyptemys insculpta Wood Turtle Reptile Emydoidea blandingii Blanding's Turtle Reptile Dracut Priority Habitat 374 (PH 374) and Estimated Habitat 263 (EH 263)Scientific name Common Name Taxonomic Group Glyptemys insculpta Wood Turtle Reptile Emydoidea blandingii Blanding's Turtle Reptile Dracut Priority Habitat 678 (PH 678) and Estimated Habitat 636 (EH 636)Scientific name Common Name Taxonomic Group Glyptemys insculpta Wood Turtle Reptile Ambystoma laterale Blue-Spotted Salamander Amphibian Dracut Priori ty Habitat 1321 (PH 1321) and Estimated Habitat 65 (EH 65)Scientific name Common Name Taxonomic Group Haliaeetus leucocephalus Bald Eagle Bird Neurocordulia obsoleta Umber Shadowdragon Dragonfly Andover Priority Habitat 1322 (PH 1321) and Estimated Habitat 65 (EH 65)Scientific name Common Name Taxonomic Group Hatiaeetus trucocephalus Bald Eagle Bird Neurocordulia obsoleta Umber Shadowdragon Dragonfly State Status Special Concern Threatened State Status Special Concern Threatened State Status Special Concern Special Concern State Status Endangered Special Concern State Status Endangered Special Concern The species listed above are protected under the Massachusetts Endangered Species Act (MESA) (M.G.L. c.131A) and its implementing regulations (321 CMR 10.00). State-listed wildlife are also protected under the state's Wetlands Protection Act (WPA) (M.G.L. c. 131, s. 40) and its implementing regulations (310 CMR 10.00).Fact sheets for most state-listed rare species can be found on our website (www.nhesp.org).

This evaluation is based on the most recent information available in the NHESP database, which is constantly being expanded and updated through ongoing research and inventory.

If you have any questions regarding this letter please contact Emily Holt, Endangered Species Review Assistant, at (508) 389-6361.Sincerely, Thomas W. French, Ph.D.Assistant Director.;,KýL cc: Sarah Barnum, Normandeau Associates, Inc.Seabrook Station Unit 1 License Renewal Application Page C-67 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence ATTACHMENT D STATE HISTORIC PRESERVATION OFFICE CORRESPONDENCE Letter Page Michael O'Keefe (FPL Energy Seabrook) to New Hampshire Division of H isto rica l R e so urces ........................................................................................

D -2 New Hampshire Division of Historical Resources to Michael O'Keefe (F P L E nergy S eabrook) ..................................................................................

D -15 Michael O'Keefe (FPL Energy Seabrook) to W. F. Galvin (Massachusetts H istorical C om m ission ...................................................................................

D -17 Brona Simon (Massachusetts Historical Commission) to Michael O'Keefe (F P L E nergy S eabrook) ..................................................................................

D -28 Seabrook Station Unit 1 License Renewal Application Page D-1 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence 0 FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7000 April 13, 2009 SBK-L-09050 New Hampshire Division of Historical Resources State Historic Preservation Office 19 Pillsbury Street Concord, NH 03301-3570 Attention:

Review & Compliance Seabrook Station Request for Project Review by the New Hampshire Division of Historical Resources FPL Energy Seabrook, LLC (FPL Energy Seabrook) is enclosing a Request for Project Review by the New Hampshire Division of Historical Resources.

FPL Energy Seabrook, the owner of a controlling interest in and the operator of Seabrook Station plans to apply to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the Operating License for 20 years beyond the current expiration date. The NRC Operating License for Seabrook Station expires at midnight on March 15, 2030. FPL Energy Seabrook plans to submit its application to the NRC in the second quarter of 2010.If you have any questions regarding this information, please contact me, at (603) 773-7745, Thank you in advance for your assistance.

Sincerely yours, Michael O'Keefe Licensing Manager Enclosure an FPL Group company Seabrook Station Unit 1 License Renewal Application Page D-2 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Please mail the completed form and required material to: New Hampshire Division of Historical Resources State Historic Preservation Office Attention:

Review & Compliance 19 Pillsbury Street, Concord, NH 03301-3570 DER Use Only R&C#LogInDate I__ I Response Date -I Sent Date / I Request for Project Review by the New Hampshire Division of Historical Resources[This is a new submittal"]This is additional information relating to DHR Review #: GENERAL PROJECT INFORMATION Project Title License Renewal for the Seabrook Station Nuclear Power Plant Project Location Seabrook, New Hampshire NH State Plane Geographic Coordinates:

Easting 1202708 Northing 146127 Lead Federal Agency Nuclear Regulatory Commission (Agency providing funds, licenses, or permits)Permit or Job Reference

1. n/a State Agency and Contact (if applicable)

Permit or Job Reference

1. APPLICANT INFORMATION Applicant Name FPL Energy Seabrook, LLC Street Address Seabrook Station, P.O. Box 300, Lafayette Road Phone Number 6037737000 City Seabrook State NH Zip 03874 Email CONTACT PERSON TO RECEIVE RESPONSE Name/Company Mr. Richard Clich6 I FPL Energy Seabrook, LLC Street Address Seabrook Station, P.O. Box 300, Lafayette Road Phone Number 6037737003 City Seabrook State NH Zip 03874 Email richard~cliche@fpl.com Please refer to the Request for Project Review manual for direction on completing this form. Submit one copy of this project review form for each project for which review is requested.

Include a self-addressed stamped envelope to expedite review response.

Project submissions will not be accepted via facsimile or e-mail. This form is required.Review request form must be complete for review to begin. Incomplete forms will be sent back to the applicant without comment. Please be aware that this form may only initiate consultation.

For some projects, the Division of Historical Resources (DHR) may require additional information to complete our review. All items and supporting documentation submitted with a review request, including photographs and publications, must be retained by the DHR as part of its review records. Items to be kept confidential should be dearly identified.

For questions regarding the DHR review process, please visit our website at: http://www.nh.gov/nbdhr/review or contact the R&C Specialist at 603.271.3558.

Seabrook Station Unit 1 License Renewal Application Page D-3 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence PROJECT BOUNDARIES AND DESCRIPTION PROJECTS CANNOToBE PROCESSED WITHOUT TIHS INFORMATION REQUIRED[ Attach the relevant portion of a 7.5' USGS Map (photocopied or computer-generated) indicating the defined project boundary.[ Attach a detailed written description of the proposed project. Include: (1) a narrative description of the proposed project; (2) site plan; (3) photos and description of the proposed work if the project involves rehabilitation, demolition, additions, or alterations to existing buildings or structures; and (4) a photocopy of the relevant portion of a soils map (if accessible) for ground-disturbing projects.Architecture Are there any buildings or structures within the project area? Dl Yes Z No If yes, submit all of the following information:

Approximate age(s): El Photographs of each building located within the project area along with a photo key. Include streetscape images if applicable. (Digital photographs are accepted.

All photographs must be clear, crisp and focused)Please note that as part of the review process, the DHR may request an architectural survey or other additional information.

Archaeoloev Does the proposed undertaking involve ground-disturbing activity?

E] Yes 0 No If yes, submit all of the following information:

E] Project specific map and/or preliminary site plan that fully describes the project boundaries and areas of proposed excavation.

El Description of current and previous land use and disturbances.

El Any available information concerning known or suspected archaeological resources within the project area.Please note that as part of the review process, the DHR may request an archaeological survey or other additional information.

DHR COMMENT ThisSpace for Resources Use Only"l No Potential to cause Effects El Additional information is needed in order to complete our review E" No Adverse Effect El No Historic Properties Affected El Adverse Effect Comments: If plans change or resources are discovered in the course of this project, you must contact the Division of Historical Resources as required by federal law and regulation.

Authorized Signature:

Date: Seabrook Station Unit 1 Page D-4 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence FPLE Seabrook, LLC Request for Project Review Seabrook Station Nuclear Power Plant Additional Information Description of the Proposed Undertaking The proposed undertaking to be considered by the Nuclear Regulatory Commission (NRC) is whether to renew the license for continued operation and maintenance of the existing Seabrook Station Nuclear Power Plant (Seabrook Station).

The license term would be an additional 20 years. Continued operation and maintenance of Seabrook Station and its associated infrastructure would not involve any license-related construction, demolition, or refurbishment activities.

Routine operation and maintenance activities would continue to occur as they have since the plant started operations in 1986. All such activities would occur in areas previously disturbed through construction activities.

Description of the Seabrook Station and Associated Infrastructure Seabrook Station is situated on approximately 889 acres east of Seabrook, New Hampshire (Figures 1 and 2). It is located along Route 1, two miles north of the Massachusetts border. The station received a construction license from the Atomic Energy Commission in 1976 and an operating license in 1986. The station layout can be seen in Figure 3.Existing infrastructure associated with the operation of Seabrook Station includes transmission lines and intake/discharge systems. There are three transmission lines serving the Seabrook Station (Figure 4):+ Scobie Pond 345 kV Line -this is a single circuit line that runs west from Seabrook Station in a 245 to 255-foot wide corridor shared with the Tewksbury Line for approximately five miles. After the Tewksbury Line splits off, the corridor becomes 170 feet wide and continues west approximately 25 miles to termination at the Scobie Pond Substation in Denry, New Hampshire.

• Tewksbury 345 kV Line -this is a single circuit line that runs west from Seabrook Station in a 245 to 255-foot wide corridor shared with the Scobie Pond Line for approximately five miles. After the Scobie Pond Line splits off, the corridor becomes 170 feet wide and continues south and west approximately 20 miles to termination at the Ward Hill Substation in Ward Hill, Massachusetts.

• Newington 345 kV Line -this is a single circuit line that runs north from Seabrook Station in a 170-foot wide corridor for approximately

4.5 miles

to termination at the Timber Swamp Substation in Hampton Falls, New Hampshire.

It then continues approximately 13.5 miles north to the Newington Generating Station.Seabrook Station Unit 1 Page D-5 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence The cooling system for Seabrook Station uses water from the Atlantic Ocean (Figure 5). Water is brought to the plant through a 17,000-foot long intake tunnel imbedded in the underlying bedrock. Water is returned to the ocean through a 16,500-foot long discharge tunnel also imbedded in the underlying bedrock. The tunnels begin below Seabrook Station at 240 feet below mean sea level and gradually ascend to approximately 160 feet below the ocean surface, where they connect to the intake and discharge shafts offshore.Previous Cultural Resource Studies and Compliance In October and November 1973, an archaeological survey was conducted for the planned Seabrook Station site by Charles Bolian of the University of New Hampshire, a consultant to the applicant (Bolian, 1974). This survey was conducted in support of development of the Environmental Report for the construction license application.

The consultant conducted a surface reconnaissance and performed selected test excavations in areas that appeared to have archaeological deposits.

The survey identified five archaeological sites on the Seabrook Station plant site. All five had prehistoric components, and one also had a European Contact Period component.

Two of the sites were determined to be outside of the area proposed for construction activities and no further work was conducted on them. Three of the sites (NH47-20, -21, and -22) were determined to be within the area of proposed construction and were excavated in 1974 and 1975 by Charles Bolian of the University of New Hampshire, with the assistance of avocational archaeologists and volunteers (Robinson and Bolian, 1987). These three sites together comprise the Rocks Road Site. The Rocks Road Site was a prehistoric habitation area that was occupied intermittently from the Late Archaic through Historic Periods (a span of over 4,000 years), with major occupations in the Middle Woodland and Contact Period. Four prehistoric burials were identified and excavated from the site. Two separate studies were conducted of the burials. The first was conducted in 1981 by Howard M. Hecker of the University of New Hampshire (Hecker, 1981). The second study was conducted in 1994 by Marcella H. Sorg of Sorg Associates for the New Hampshire Division of Historical Resources, and was likely conducted to meet the inventory requirements promulgated by the Native American Graves Protection and Repatriation Act (NAGPRA) (Sorg, 1994).The remains of all four individuals were transferred to the NH Division of Historical Resources for curation in 1999. In compliance with NAGPRA, the Notice of Inventory Completion for the human remains from the Rocks Road Site was published in the Federal Register in 2002 (Federal Register, 2002). The Notice reports that this portion (Seabrook Station region) of New Hampshire is within the aboriginal and historic homeland of the Western Abenaki, Eastern Abenaki, and the Wampanoag native groups. The Notice states the determination of the NH Division of Historical Resources that there is a relationship of shared group identity between the human remains and the Abenaki Nation of Missisquoi.

A Notice of Intent to Repatriate Cultural Items was published in the Federal Register in 2008 (Federal Register, 2008). This Notice reports that the Rocks Road Site human remains were repatriated to the Abenaki Nation of Missisquoi following the Notice published in 2002. While the 2002 Notice stated that no associated funerary objects were present with the four burials, the 2008 Notice states that after repatriation, cultural items associated with the burials were discovered by the University of New Hampshire among its collections.

The 2008 Notice states Seabrook Station Unit 1 Page D-6 License Renewal Application Appendix E -Environmental Report Attachment D , State Historic Preservation Office Correspondence the determination by the University of New Hampshire that that there is a shared group identity between the funerary objects and the Abenaki Nation of New Hampshire and the Cowasuck Band of Pennacook-Abenaki People, and that unless another group contacts them, disposition of the funerary objects to these groups would occur after June 30, 2008.In 1982, the NRC consulted with the Advisory Council on Historic Preservation regarding the potential effect of operation of the Seabrook Station on historic properties for the NRC's Environmental Statement (NRC 1982). The NRC determined that there would be no effect to properties included in or eligible for the National Register of Historic Places, and the Advisory Council concurred.

FPL Energy Seabrook knows of two archaeological resources on the plant site. Both sites are prehistoric and, at the time of the 1973 survey, one was reported as being impacted by vehicular traffic resulting in compaction, erosion, and mixing. FPL Energy Seabrook is not aware of any historic or archaeological resources that have been affected to date by Seabrook Station operations, including operation and maintenance of transmission lines. Because FPL Energy Seabrook is aware of the potential for discovery of cultural resources during land-disturbing activities at Seabrook Station, it has developed procedures that protect archaeological resources on the Seabrook Station site.Designated Resources Near the Seabrook Station As of January 2009, the National Register of Historic Places listed 111 properties in Rockingham County, New Hampshire (National Park Service 2009a). Of these, 10 properties in Rockingham County are located within 6 miles of the Seabrook Station. Table I lists the 10 properties within 6 miles of the station. There are no National Historic Landmarks in Rockingham County within 6 miles of the Seabrook Station (National Park Service 2009b).Seabrook Station Unit 1 License Renewal Application Page D-7 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Table 1. New Hampshire properties listed in the National Register of Historic Places that fall within a 6-mile radius of Seabrook Station Property Location Benjamin James house 186 Towle Farm Road, Hampton Reuben Lamprey homestead 416 Winnacunnet Road, Hampton Unitarian Church Exeter Road, Hampton Falls Gov. Meshech Weare house Exeter Road, Hampton Falls Captain Jonathan Currier house, part of Hilidale Avenu6, South Hampton South Hampton MRA Highland Road Historic District, part of Highland and Woodman Roads, South South Hampton MRA Hampton Jewell Town District, part of South W. Whitehall Road and Jewell Street, South Hampton MRA Hampton Smith's Comer Historic District, part of Chase Road, South Hampton South Hampton MRA Town Center Historic District, part of Main and Hilldale Avenues and Jewel Street, South Hampton MRA South Hampton Woodman Road Historic District, part of Woodman Road, South Hampton South Hampton MRA MRA = multiple resource area The New Hampshire Division of Historical Resources maintains the State Register of Historic Places. There is one listed property within the 6-mile radius of the Seabrook Station, Marelli's Market at Lafayette Road in Hampton, NH. (NH DHR 2009).None of the designated national or state properties discussed above are located within or adjacent to the Seabrook Station property.Assessment of Effect The undertaking involves renewal of the operating license for Seabrook Station for 20 years and continued operation and maintenance activities during the term of the license. No license-related construction, demolition, or refurbishment activities would be conducted.

Routine operation and maintenance activities would continue in areas previously disturbed by construction activities.

Seabrook Station has procedures in place to ensure protection of historic and archaeological resources during operation and maintenance activities therefore, FPL Energy Seabrook concludes that there would be no effect to historic properties from license renewal and associated operation and maintenance activities.

Seabrook Station Unit 1 License Renewal Application Page D-8 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence References Cited Bolian, Charles E. 1974. Report: An Archaeological Survey of the Seabrook Site. University of New Hampshire, Durham.Federal Register.

2002. Notice of Inventory Completion for Native American Human Remains and Associated Funerary Objects in the Control of Franklin Pierce College, Rindge, NH;Manchester Historical Association, Manchester, NH; NH Division of Historical Resources, Concord, NH; and University of New Hampshire, Durham, NH; and in the Possession of the New Hampshire Division of Historical Resources, Concord, NH. U.S. Department of the Interior, National Park Service. Federal Register 67(131):45536

-45539. July 9, 2002.Federal Register.

2008. Notice of Intent to Repatriate Cultural Items: University of New Hampshire, Durham, NH. U.S. Department of the Interior, National Park Service. Federal Register 73(104):30967

-30968. May 29,2008.Hecker, Howard M. 1981. Preliminary Physical Anthropological Report on the 650 Year Old Skeleton from Seabrook, New Hampshire.

Man in the Northeast 21: 37 -60.National Park Service. 2009a. Properties in Rockingham County, NH, Listed on the National Register of Historic Places. -National Register Information System, accessed on January 2, 2009. httR://www.nr.nps.zov/iwisapi/explorer.dll/x2 3anr4 3aNRISl/script/report.iws.

National Park Service. 2009b. National Historic Landmarks within the 6-mile Radius of Seabrook Station. National Historic Landmarks Program database, accessed on January 2, 2009.http://tps.cr.nps.gov/nhl.

NH DHR (New Hampshire Division of Historical Resources).

2009. NH State Register of Historic Places, Listed Properties by Town. Accessed on January 2, 2009.http://www.nh.gov/nhdhr/programs/StateRegisterListingsByTown.htm.

NRC (Nuclear Regulatory Commission).

1982. Final Environmental Statement related to the operation of Seabrook Station, Units I and 2. Office of Nuclear Reactor Regulation, Docket Nos. 50-443 and 50-444, NUREG-0895.

December 1982.Robinson, Brian S., and Charles E. Bolian. 1987. A Preliminary Report on the Rocks Road Site (Seabrook Station):

Late Archaic to Contact Period Occupation in Seabrook, New Hampshire.

The New Hampshire Archeologist 28(1): 19 -48.Sorg, Marcella.

1994. Osteology and Odontology of Human Remains from Seabrook, New Hampshire (NH47-21).

Prepared for the NH Division of Historical Resources.

Sorg Associates, Orono, Maine.Seabrook Station Unit 1 Page D-9 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Seabrook Station Unit 1 License Renewal Application Page D-1O Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Seabrook Station Unit 1 License Renewal Application Page D-11 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence 0 000 00~ ow FM.Legend m Shie Boundary Figure 3 Site Plan of the Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page D-12 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Seabrook Station Unit 1 License Renewal Application Page D-13 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Intake Shafts ,t'and Structures Discharge Shafts.andý d r Nozzlea DISCHARGE TUNNEL AND SHAFTS Seabrook Plant Sitell11 11 I I I Intake Shaft Discharge Shaft Figure 5 Cooling Water Intake/Discharge Structures for Seabrook Station Nuclear Power Plant Drawings not to scale Seabrook Station Unit 1 License Renewal Application Page D-14 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Please mail the completed form and required material to: New Hampshire Division of Historical Resources State Historic Preservation Office Attention:

Review & Compliance 19 Pillsbury Street, Concord, NH 08301-3570 DHR Use Only R&C#Log.nDate Y./k/A Response Date 1_00?Sent Date 13.Co LU tUJ Request for Project Review by the New Hampshire Division of Historical Resources ZThis is a new submittal EJfhis is additional information relating to DHR Review #: GENERAL PROJECT INFORMATION Project Title License Renewal for the Seabrook Station Nuclear Power Plant Project Location Seabrook New Hampshire NH State Plane Geographic Coordinates:

Basting 1202708 Northing 146127 Lead Federal Agency Nuclear Regulatory Commission (Agency providing funds, licenses, or permits)Permit or Job Reference

1. n/a State Agency and Contact (if applicable)

Permit or Job Reference

1. APPLICANT INFORMATION Applicant Name FPL Energy Seabrook, LLC Street Address Seabrook Station, P.O. Box 300, Lafayette Road Phone Number 6037737000 City Seabrook State NHI Zip 03874 Email CONTACT PERSON TO RECEIVE RESPONSE Name/Company Mr. Richard Clich6 I FPL Energy Seabrook, LLC Street Address Seabrook Station, P.O. Box 300. Lafayette Road Phone Number 6037737003 City Seabrook State NH Zip 03874 Email richard-cliche@fpl.com Please refer to the Request for Project Review manual for direction on completingthis form. Submit one copy of this poject review form for each project for which review is requested. "lawaik-twifafire" Project submissions will not be accepted via facsimile or e-mail. This form is required.Review request form must be complete for review to begin. Incomplete forms will be sent back to the applicant without comment. Please be aware that this form may only initiate consultation.

For some projects, the Division of Historical Resources (DHR) may require additional information to complete our review. All items and supporting documentation submitted with a review request, including photographs and publications, must be retained by the DHR as part of its review records. Items to be kept confidential should be clearly identified.

For questions regarding the DHR review process, please visit our website at: http://www.nh.govlnhdlnx/review or contact the R&C Specialist at 603.271.3558.

Seabrook Station Unit 1 License Renewal Application Page D-15 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence REQUIRED[ Attach the relevant portion of a 7.5' USGS Map (photocopied or computer-gene.ated) indicating the defined project boundary.[ Attach a detailed witten description of the proposed project. Include: (1) a narrative description of the proposed project; (2) site plan; (3) photos and description of the proposed work if the project involves rehabilitation, demolition, additions, or alterations to existing buildings or structures; and (4) a photocopy of the relevant portion of a soils map (if accessible) for ground-disturbing projects.Are there any buildings or structures within the project area? O Yes 0] No If yes, submit all of the following information:

Approximate age(s): C] Photographs of each building located within the project area along with a photo key. Include atreetacape images if applicable. (Digital photographs are accepted.

All photographs must be clear, crisp and focused)Please note that as part of the review process, the DHR may request an architectural survey or other additional information.

Archaeoloov Does the proposed undertaking involve ground-dieturbing activity?

El Yes 0 No If yes, submit all of the following information:

[1 Project specific map and/or preliminary site plan that fully describes the project boundaries and areas of proposed excavation.

[] Description of current and previous land use and disturbances.

E] Any available information concerning known or suspected archaeological resources within the project area.Please note that as part of the review process, the DHR may request an archaeological survey or other additional information, 14.i o .otential to cauise ,ffec ;aEl ,cdtotlif, tto is needed iný' ore to coi p ou le'new 0 N Avo~eEfec M No.Historic P'roperte fetd I]AvreEfc 4. Val.If plans change or iesources are. discovered in the course of this project you must contact the Division of Hiiatocedl Resoureep As re~quire by seee La nd gulatin A&uthorise Sinature:.-

6 ..ae L~2~~'Seabrook Station Unit 1 Page D-16 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence NEXTera ENEFR~February 19, 2010 SBK-L- 10031 Mr. W. F. Galvin Secretary of the Commonwealth Massachusetts Historical Commission 220 Morrissey Blvd.Boston, Ma. 02125 -3314 Seabrook Station Tewksbury Transmission Line Proiect Notification NextEra Energy Seabrook, LLC (NextEra Energy Seabrook) is enclosing a Project Notification Form to the Massachusetts Historical Commission.

NextEra Energy Seabrook, the owner of a controlling interest and the operator of Seabrook Station, plans to apply to the U.S. Nuclear Regulatory Commission (NRC) for renewal of the NextEra Energy Seabrook Facility Operating License for 20 years beyond the ciurrent expiration date. The Facility Operating License for Seabrook Station expires at midnight on March 15, 2030. NextEra Energy Seabrook plans to submit its application to the NRC in the second quarter of 2010.NRC requires that a license renewal application include an environmental report, and that impacts of the proposed action (license renewal) on transmission lines be considered.

One transmission line from Seabrook Station, the Tewksbury line, extends approximately 20 miles into Massachusetts, to the Ward Hill Substation.

It is that component of the project that we are seeking Massachusetts Historical Commission review.Included with the Project Notification Form is an attachment that describes the project and historic resources in the Commonwealth of Massachusetts within 6 miles of the project. Table 1 of the attachment lists sites on the National Historic Register within 6 miles of the project. Table 2 lists properties within 2 miles of the transmission line. Figure 3 of the attachment is a USGS quadrangle map with the transmission corridor marked.Should you have any questions regarding this letter please contact Mr. Richard Cliche, Seabrook Station License Renewal Project Manager, (603) 773-7003.

Thank you in advance for your assistance.

Sincerely, NextEra Energy Seabrook, LLC Michael O'Keefe Licensing Manager NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874 Seabrook Station Unit 1 Page D-17 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence 950 CMR: OFFICE OF THE SECRETARY OF THE COMMONWEALTH APPENDIX A MASSACHUSETTS HISTORICAL COMMISSION 220 MORRISSEY BOULEVARD BOSTON, MASS. 02125 617-727-8470, FAX: 617-727-5128 PROJECT NOTIFICATION FORM Projeci Name: License Renewal for Seabrook Station Nuclear Power Plant Location / Address: State Plane Geographic Coordinates:

Easting 1202708 Northing 146127 City / Town: Seabrook, NH Project Proponent Name: NextEra Energy Seabrook, LLC Address: Seabrook Station, P.O. Box 300, Lafayette Road City/rown/Zip/Telephone:

Seabrook NH, 03874 /(603) 773 7000 Agency license or funding for the project (list all licenses, permits, approvals, grants or other entitlements being sought from state and federal agencies).

Ana Name Tvne of License or fundin (snecify U.S. Nuclear Regulatory Commission Facility Operating License Renewal Project Description (narrative):

see attached narrative

-specifically see information regarding Tewksbury 345 kV transmission line which runs for approximately 20 miles from the MA line to the Ward Hill substation Does the project include demolition?

Ifso, specify nature of demolition and describe the building(s) which are proposed for demolition.

No Does the project include rehabilitation of any existing buildings?

If so, specify nature of rehabilitation and describe the building(s) which are proposed for rehabilitation.

No Does the project include new construction?

If so, describe (attach plans and elevations if necessary).

No 5/31/96 (Effective 7/1/93) -corrected 950 CMR -275 Seabrook Station Unit 1 Page D-18 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence 950 CMR: OFFICE OF THE SECRETARY OF THE COMMONWEALTH APPENDIX A (continued)

To the best of your knowledge, are any historic or archaeological properties known to exist within the project's area of potential Impact? If so, specify. NextEra Energy Seabrook is not aware of any sites within the transmission line right-of-way.

Twenty historic properties occur within a 2-mile radius of the ROW.What is the total acreage of the project area? approximately 618 acres (20 miles of 245' -255-wide ROW)Woodland _mes Wetland acres Floodplain aces Open space ams Developed

_ ares Productive Resources:

Agriculture aces Forestry acres Mining/Extraction

_ aes Total Project Acreage acres What Is the acreage Of the proposed new construction?

0 acres What Is the present land use of the project area? transmission line right of way Please attach a copy of the section of the USGS quadrangle map which clearly marks the project location.See Figure 3 of the attachment This Project Notification Form has been submitted to the MHC in comipliance with 950 CMR 71.00.Signature of Person submitting this form: Date: ' 10 Name: Richard Cliche , License Renewal Project Manager Address: Seabrook Station, P.O. Box 300 City/town/Zip:

Seabrook, NH 03874 Telephone:

603 773 7003 REGULATORY AUTHORITY 950 CMR 71.00. M.G.L. c. 9, §26-27C as amended by St. 1988, c. 254.7/1/93 950 CMR -276 Seabrook Station Unit 1 License Renewal Application Page D-19 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence NextEra Energy Seabrook, LLC Request for Project Review Seabrook Station Nuclear Power Plant Additional Information Description of the Proposed Undertaking The proposed undertaking to be considered by the Nuclear Regulatory Commission (NRC) is whether to renew the license for continued operation and maintenance of the existing Seabrook Station Nuclear Power Plant (Seabrook Station).

The license term would be an additional 20 years. Continued operation and maintenance of the Seabrook Station and its associated infrastructure would not involve any license-related construction, demolition, or refurbishment activities.

Routine operation and maintenance activities would continue to occur as they have since the plant started operations in 1990. All such activities would occur in areas previously disturbed through construction activities.

Description of the Seabrook Station and Associated Infrastructure The Seabrook Station is situated on approximately 889 acres east of Seabrook, New Hampshire (Figures 1). It is located along Route 1, two miles north of the Massachusetts border. The station received a construction license from the Atomic Energy Commission in 1976 and an operating license in 1990.Existing infrastructure associated with the operation of Seabrook Station includes transmission lines and intake/discharge systems. There are three transmission lines serving Seabrook Station (Figure 2 and 3): " Scobie Pond 345 kV Line -this is a single circuit line that runs west from Seabrook Station in a 245 to 255-foot wide corridor shared with the Tewksbury Line for approximately five miles. After the Tewksbury Line splits off, the corridor becomes 170 feet wide and continues west approximately 25 miles to termination at the Scobie Pond Substation in Denry, New Hampshire." Tewksbury 345 kV Line -this is a single circuit line that runs west from Seabrook Station in a 245 to 255-foot wide corridor shared with the Scobie Pond Line for approximately 5 miles. After the Scobie Pond Line splits ofl the corridor becomes 170 feet wide and continues south and west approximately 20 miles to termination at the Ward Hill Substation in War Hill, Massachusetts." Newington 345 kV Line -this is a single circuit line that runs north from Seabrook Station in a 170-foot wide corridor for approximately

4.5 miles

to termination at the Timber Swamp Substation in Hampton Falls, New Hampshire.

It then continues approximately 13.5 miles north to the Newington Generating Station.Seabrook Station Unit 1 Page 0-20 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence The cooling system for Seabrook Station uses water from the Atlantic Ocean. Water is brought to the plant through a 17,000-foot long intake tunnel imbedded in the underlying bedrock. Water is returned to the ocean through a 16,500-foot long discharge tunnel also imbedded in the underlying bedrock. The tunnels begin below the Seabrook Station plant at 240 feet below mean sea level and gradually ascend to approximately 160 feet below the ocean surface, where they connect to the intake and discharge shafts offshore.Previous Cultural Resource Studies and Compliance In October and November 1973, an archaeological survey was conducted for the planned Seabrook Station site by Charles Bolian of the University of New Hampshire, a consultant to the applicant (Bolian, 1974). This survey was conducted in support of development of the Environmental Report for the construction license application.

The consultant conducted a surface reconnaissance and performed selected test excavations in areas that appeared to have archaeological deposits.

The survey identified five archaeological sites on the Seabrook Station plant site. All five had prehistoric components, and one also had, a European Contact Period component.

Two of the sites were determined to be outside of the area proposed for construction activities and no further work was conducted on them. Three of the sites (1, 3, and 4 [NH47-20])

were determined to be within the area of proposed construction and were excavated in 1974 and 1975 by Charles Bolian of the University of New Hampshire, with the assistance of avocational archaeologists and volunteers (Robinson and Bolian, 1987). These three sites together comprise the Rocks Road Site. The Rocks Road Site was a prehistoric habitation area that was occupied intermittently from the Late Archaic through Historic Periods (a span of over 4,000 years), with major occupations in the Middle Woodland and Contact Period. Four prehistoric burials were identified and excavated from the site. Two separate studies were conducted of the burials. The first was conducted in 1981 by Howard M. Hecker of the University of New Hampshire (Hecker, 1981). The second study was conducted in 1994 by Marcella H. Sorg of Sorg Associates for the New Hampshire Division of Historical Resources, and was likely conducted to meet the inventory requirements promulgated by the Native American Graves Protection and Repatriation Act (NAGPRA) (Sorg, 1994).The remains of all four individuals were transferred to the NH Division of Historical Resources for curation in 1999. In compliance with NAGPRA, the Notice of Inventory Completion for the human remains from the Rocks Road Site was published in the Federal Register in 2002 (Federal Register, 2002). The Notice reports that this portion (Seabrook Station region) of New Hampshire is within the aboriginal and historic homeland of the Western Abenaki, Eastern Abenaki, and the Wampanoag native groups. The Notice states the determination of the NH Division of Historical Resources that there is a relationship of shared group identity between the human remains and the Abenaki Nation of Missisquoi.

A Notice of Intent to Repatriate Cultural Items was published in the Federal Register in 2008 (Federal Register, 2008). This Notice reports that the Rocks Road Site human remains were repatriated to the Abenaki Nation of Missisquoi following the Notice published in 2002. While the 2002 Notice stated that no associated finerary objects were present with the four burials, the 2008 Notice states that after repatriation, cultural items associated with the burials were 2 Seabrook Station Unit 1 Page D-21 License Renewal Application Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence discovered by the University of New Hampshire among its collections.

The 2008 Notice states the determination of the University of New Hampshire that that there is a shared group identity between the funerary objects and the Abenaki Nation of New Hampshire and the Cowasuck Band of Pennacook-Abenaki People, and that unless another group contacts them, disposition of the fbnerary objects to these groups would occur after June 30, 2008.In 1982, the NRC consulted with the Advisory Council on Historic Preservation regarding the potential effect of operation of the Seabrook Station on historic properties for the NRC's Environmental Statement (NRC 1982). The NRC determined that there would be no effect to properties included in or eligible for the National Register of Historic Places, and the Advisory Council concurred.

NextEra Energy Seabrook knows of two archaeological resources on the plant site. Both sites are prehistoric and, at the time of the 1973 survey, one was reported as being impacted by vehicular traffic resulting in compaction, erosion, and mixing. NextEra Energy Seabrook is not aware of any historic or archaeological resources that have been affected to date by Seabrook Station operations, including operation and maintenance of transmission lines. Because NextEra Seabrook is aware of the potential for discovery of cultural resources during land-disturbing activities at Seabrook Station, is developing procedures that will protect archaeological resources on the Seabrook Station site.Designated Resources Near the Seabrook Station As of January 2009, the National Register of Historic Places listed 444 properties in Essex County, Massachusetts (National Park Service 2009a). Of these, 9 properties are within 6 miles of the Seabrook Station and 20 are within 2 miles of the transmission line. Table 1 lists the nine properties within 6 miles of the station. Table 2 lists the 20 properties within 2 miles of the transmission line.Table 1. Massachusetts properties listed in the National Register of Historic Places within a 6-mile radius of Seabrook Station Property Location Amesbury and Salisbury Mills Village Historic Boardman, Water, Main, and Pond Streets, District Amesbury Amesbury Friends Meetinghouse 120 Friend Street, Amesbury Lowell's Boat Shop 459 Main Street, Amesbury Rocky Hill Meetinghouse and Parsonage Portsmouth Road and Elm Street, Amesbury Walker Body Company Factory Oak Street at River Court, Amesbury John Greenleaf Whittier house 86 Friends Street, Amesbury Newburyport Harbor Front Range Light Station, Newburyport Newburyport Historic District Plummer, State, and High Streets, Newburyport Ann's Diner 11 Bridge Road, Salisbury National Park Service 2009a Seabrook Station Unit 1 License Renewal Application Page D-22 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence, Table 2. Massachusetts properties listed In the National Register of Historic Places within a 2-mile radius of the Tewksbnry transmission line Property Adams-Clarke House Amesbury and Salisbury Mills Village Historic District Amesbury Friends Meeting House Samuel Chase House Ephraim Davis House Georgetown Central School Joseph Hardy House George Hopkinson House House at 922 Dale Street Intervale Factory Capt. Timothy Johnson House George Kunhardt Estate Samuel Marsh House Timothy Morse House Newell Farm Osgood Hill Col. John Osgood House Rocks Village Historic District Rev. John Tufts House John Greenleaf Whittier House National Park Service 2009a Location 93 W. Main Street, Georgetown Market Square, roughly bounded by Boardman, Water, Main and Pond Streets, Amesbury 120 Friend Street, Amesbury 154 Main Street, West Newbury Merrimack Road, Haverhill I Library, Street, Georgetown 93 King Street, Grovetown 362 Main Street, Groveland 922 Dale Street, Andover 402 River Street, Haverhill 18 -20 Stevens Street, Essex 1518 Great Pond Road, North Andover 444 Main Street, West Newbury 628 Main Street, West Newbury 243 Main Street, West Newbury 709 and 723 Osgood Street, Andover 547 Osgood Street, Andover NE of Haverhill at Merrimack River, Haverhill 750 Main Street, West Newbury 86 Friend Street, Amesbury Assessment of Effect The undertaking involves renewal of the operating license for Seabrook Station for 20 years and continued operation and maintenance activities during the term of the license. No license-related construction, demolition, or refurbishment activities would be conducted.

Routine operation and maintenance activities would continue in areas previously disturbed by construction activities.

Therefbre, NextEra Energy concludes that there would be no effect to historic properties from license renewal and associated operation and maintenance activities.

Seabrook Station Unit 1 License Renewal Application Page D-23 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence REFERENCES CITED Bolian, Charles E. 1974. Report: An Archaeological Survey of the Seabrook Site. University of New Hampshire, Durham.Federal Register.

2002. Notice of Inventory Completion for Native American Human Remains and Associated Funerary Objects in the Control of Franklin Pierce College, Rindge, NH;Manchester Historical Association, Manchester, NH; NH Division of Historical Resources, Concord, NH; and University of New Hampshire, Durham, NH; and in the Possession of the New Hampshire Division of Historical Resources, Concord, NH. U.S. Department of the Interior, National Park Service. Federal Register 67(131):45536

-45539. July 9, 2002.Federal Register.

2008. Notice of Intent to Repatriate Cultural Items: University of New Hampshire, Durham, NH. U.S. Department of the Interior, National Park Service. Federal Register 73(104):30967

-30968. May 29, 2008.Hecker, Howard M. 1981. Preliminary Physical Anthropological Report on the 650 Year Old Skeleton from Seabrook, New Hampshire.

Man in the Northeast 21: 37 -60.MHC (Massachusetts Historical Commission).

2009. State and Local Archaeological and Historical Landmarks in Amesbury, Salisbury, and Newburyport, Massachusetts.

Massachusetts Cultural Resource Information System Database.

Accessed January 2, 2009 at http://mhc-macris.net National Park Service. 2009a. Properties in Essex County, MA, Listed on the National Register of Historic Places. -National Register Information System, accessed on January 2, 2009.http://www.nr.nps.gov/iwisaoi/exolorer.dll/x2 3anr4 3aNRIS I/script/report.iws.

NRC (Nuclear Regulatory Commission).

1982. Final Environmental Statement related to the operation of Seabrook Station, Units I and 2. Office of Nuclear Reactor Regulation, Docket Nos. 50-443 and 50-444, NUREG-0895.

December 1982.Robinson, Brian S., and Charles E. Bolian. 1987. A Preliminary Report on the Rocks Road Site (Seabrook Station):

Late Archaic to Contact Period Occupation in Seabrook, New Hampshire.

The New Hampshire Archeologist 28(1): 19 -48.Sorg, Marcella.

1994. Osteology and Odontology of Human Remains from Seabrook, New Hampshire (NH47-21).

Prepared for the NH Division of Historical Resources.

Sorg Associates, Orono, Maine.Seabrook Station Unit 1 License Renewal Application Page D-24 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Seabrook Station Unit 1 License Renewal Application Page D-25 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence Legend A Substation-mr 345 WI Transmlsslon ULn m Interstate Prinary Road Seabrook Station!State Boundary County Boundary Water i Urban Area Crane Pond WMA Fish and Wildlife Service N I 0 1 2 4 6 Figure 2 Transmission Lines Associated with the Seabrook Station Nuclear Power Plant Seabrook Station Unit 1 License Renewal Application Page D-26 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence 0 050 1 2 Mides Legend Figure 3 A Substation Transmission Lines Associated with the Seabrook Station---- 345 kV Tsins.,o.

Line Nuclear Power Plant, 7.5 Minute Topographic Quandrangle Seabrook Station Unit 1 License Renewal Application Page D-27 Appendix E -Environmental Report Attachment D State Historic Preservation Office Correspondence The Commonwealth of Massachusetts William Francis Galvin, Secretary of the Commonwealth Massachusetts Historical Commission March 3, 2010 Brian Holian Director Division of License Renewal Office of Nuclear Reactor Regulation Nuclear Regulatory Commission Washington, D.C. 20555-0001 RE: Seabrook Nuclear Power Station License Renewal Application.

Tewksbury 345 kV Transmission Line to Ward Hill Substation, Amesbury, Merrimac, West Newbury, Groveland, Georgetown, Boxford, Haverhill, MA. MHC #RC.48153.

Dear Mr. Holian:

Staffofthe Massachusetts Historical Commission (MHC), office of the Massachusetts State Historic Preservation Officer (SHPO), haver'riewed a Project Notification Form (PNF) and additional informalion.

for the proposed project referenced above and have the following comments.MHC understands that the proposed license renewal for the Seabrook, New Hampshire Nuclear Power Plant, including existing 345 kV transmission lines in Massachusetts, proposes no new construction.

demolition or refurbishment activities.

Because no new construction is proposed, the MHC has no concerns.These comments are offered to assist in compliance with Section 106 of the National Historic Preservation Act of 1966, as amended (36 CFR 800). Ifyou have any'questions please contact Jonathan K. Patton at this office.Sincerely, Brona Simon State Historic Preservation Officer Executive Director Massachusetts Historical Commission xc: R ichard Cliche, NextEra Energy Seabrook, LLC Dennis L. Egan, NRC Region 1.New Hampshire Division of Historical Resources

.220 Morrissey Boulevard, Boston, Massachusetts 02125 (617) 727-8470 -Fax: (617) 727-5128 www.sec.state.ma.us/nlhc Seabrook Station Unit 1 License Renewal Application Page D-28 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification ATTACHMENT E COASTAL ZONE CONSISTENCY CERTIFICATION Seabrook Station Unit 1 License Renewal Application Page E-1 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification COASTAL ZONE CONSISTENCY CERTIFICATION Federal Consistency Certification for Federal Permit and License Applications NextEra Energy Seabrook, LLC (NextEra Energy Seabrook) certifies to the U.S. Nuclear Regulatory Commission (NRC) that renewal of the Seabrook Station operating license is consistent with enforceable policies of the federally-approved coastal zone management program for the State of New Hampshire.

The Consistency Certification is set forth below, and is followed by the information and data necessary to satisfy Coastal Zone Management Act (CMZA) requirements.

CONSISTENCY CERTIFICATION The proposed activity, NRC's renewal of the Seabrook Station operating license, complies with the enforceable policies of New Hampshire's approved coastal management program and will be conducted in a manner consistent with such program.NECESSARY DATA AND INFORMATION Statutory and Regulatory

Background

The CZMA (16 USC 1451 et seq.) imposes certification requirements on applicants for a federal license to conduct an activity that could affect a state's coastal zone. The act requires the applicant to certify in the application to the licensing agency that the proposed activity would be consistent with the state's federally approved coastal management program. The Act also requires the applicant to provide to the state a copy of the certification, with all necessary information and data, and requires the state to notify the federal agency and the applicant at the earliest practicable time whether the state concurs with, or objects to, the consistency certification.

If the state objects, the federal agency cannot issue the license unless the Secretary of Commerce determines that the activity is consistent with the objectives of the CZMA or is otherwise necessary in the interest of national security.

See 16 USC 1456(c)(3)(A).

The Secretary of Commerce has delegated federal CZMA responsibilities to the National Oceanic and Atmospheric Administration (NOAA). NOAA has promulgated regulations implementing the CZMA (15 CFR 930 et seq.) that indicate that consistency requirements apply to license renewals under certain circumstances, including renewals of federal licenses not previously reviewed by the state agency. NOAA approved the New Hampshire coastal management program in 1982 (Ref. E-5).The New Hampshire Department of Environmental Services, Water Division, Watershed Management Bureau administers the New Hampshire Coastal Program and maintains a website on the program in general (Ref. E-1). The Seabrook Station Unit 1 Page E-2 License Renewal Application Appendix E -Environmental Report Attachment E *Coastal Zone Consistency Certification website provides a link to a state coastal zone map that shows that the towns of Seabrook, Hampton and Hampton Falls are included in the coastal zone (Ref. E-2). The website also provides a link to information on federal consistency (Ref. E-3). The state has published a guide to federal consistency that lists NRC licensing and U. S. Environmental Protection Agency (EPA) permitting under the National Pollutant Discharge Elimination System (NPDES) as federal licensing activities that the state presumes have reasonably foreseeable coastal effects and thus require CZMA certification (Ref. E-4,Section IV and Appendix C.11).EPA administers the NPDES program in New Hampshire.

In 1985, the State of New Hampshire concurred with Seabrook Station's certification that EPA's issuance of the Station's NPDES permit and subsequent renewals were consistent with the New Hampshire coastal zone management program (e.g., Ref. E-9). However, the State of New Hampshire has not previously performed a CZMA review of the NRC operating license.Proposed Action The NRC license for Seabrook Station will expire in 2030. The NRC regulations provide for license renewal, and NextEra Energy Seabrook is applying for renewal of the Seabrook Station operating license. Renewal would extend the Seabrook Station operating license term to 2050.Seabrook Station is an electric generating plant located within the New Hampshire coastal zone, in the Town of Seabrook, Rockingham County, on the western shore of Hampton Harbor, two miles west of the Atlantic Ocean (Figures E-1 and E-2). The location is approximately two miles north of the Massachusetts state line. The site consists of 889 acres and is bounded on the north, east, and south by estuarine marshlands (Figure E-3).Approximately two thirds of the site area is characterized by broad open areas of level tidal marsh veined with man-made linear drainage ditches and tidal creeks. Wooded islands and peninsulas rise from the marsh to elevations of 20 to 30 feet above sea level. The developed portion of the site encompasses slightly more than 100 acres. Three transmission lines connect Seabrook Station to the New England electric grid, as shown on Figure E-4.Seabrook Station has been in commercial operation since 1990. The station is a single-unit pressurized water reactor with a net electric output of 1,245 megawatts.

The station has a once-through heat dissipation system that withdraws cooling water from, and discharges heated effluent to, the Atlantic Ocean via offshore intake and discharge structures.

During normal operations, the cooling system withdraws and discharges approximately 600 million gallons per day (gpd). The station uses approximately 115,000 gpd of fresh water from the Seabrook, New Hampshire municipal water system and normally discharges a maximum of approximately 20,000 gpd to the municipal wastewater system (discharge increases by approximately 29,000 gpd during refueling outages).

There are no major Seabrook Station Unit 1 Page E-3 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification aquifers in the site vicinity and the station's use of groundwater is limited to approximately 35,000 gpd from dewatering that discharges to the site storm water drainage system. Stormwater from the site is discharged through the cooling water system.Seabrook Station employs approximately 1,100 full-time workers and an additional 800 temporary (30-day) workers every 18 months for refueling outages.NextEra Energy Seabrook has identified no need for environmentally significant new aging management programs or major modifications to existing programs and has no plans to add outage or non-outage employees to support Seabrook Station operations during the license renewal term. As such, renewal would result in a continuation of environmental impacts currently regulated by the state. Table E-1 lists state and federal environmental licenses, permits, and other authorizations for current Seabrook Station operations and Table E-2 identifies compliance activities associated specifically with NRC license renewal.Environmental Impacts Discussion of Seabrook Station environmental impacts can be found in the following three documents:

NRC generic environmental impact statement (GELS) for license renewal NextEra Energy Seabrook environmental report for Seabrook Station license renewal Exhibit E-1 to this coastal consistency certification The following paragraphs discuss each of these documents in more detail.Prior to renewing the Seabrook Station license, the NRC will issue a site-specific supplement to the GELS. This document will also discuss the environmental impacts to the proposed action.Generic Environmental Impact Statement for License Renewal The NRC has prepared a GElS (Ref. E-6) to assess the environmental impacts that could be associated with nuclear power plant license renewal and an additional 20 years of operation of individual plants and has codified its findings (10 CFR 51, Subpart A, Appendix B, Table B-i). The codification identified 92 potential environmental issues, 69 of which the NRC identified as having small impacts and termed "Category 1 issues." The NRC defines"small" as: Small -For the issue, environmental effects are not detectable or are so minor that they will neither destabilize nor noticeably alter any important attribute of the resource.

For the purpose of assessing radiological impacts, the Commission has concluded that those impacts that do not exceed Seabrook Station Unit I Page E-4 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification permissible levels in the Commission's regulations are considered small as the term is used in this table (10 CFR 51, Subpart A, Appendix B, Table B-I)The NRC codification and the GElS discuss the following types of Category 1 environmental issues: Surface water quality, hydrology, and use Aquatic ecology Groundwater use and quality Terrestrial resources Air quality Land use Human health Postulated accidents Socioeconomics Uranium fuel cycle and waste management Decommissioning In its decision-making for plant-specific license renewal applications, absent new and significant information to the contrary, the NRC relies on its codified findings, as amplified by supporting information in the GELS, for assessment of environmental impacts from Category 1 issues [10 CFR 51.95(c)(40)].

For plants, such as Seabrook Station, that are located in the coastal zone, many of these issues involve impacts to the coastal zone. NextEra Energy Seabrook has adopted by reference the NRC findings and GElS analyses for 471 applicable Category 1 issues.Environmental Report for Seabrook Station License Renewal 2 The NRC regulation identified 21 issues as "Category 2," for which license renewal applicants must submit additional site-specific information.

3 Of these, The remaining Category 1 issues do not apply to Seabrook Station either because they are associated with design or operational features the Seabrook Station does not have (e.g., circulating water cooling towers) or to an activity, refurbishment, that Seabrook Station will not undertake.

2 This consistency certification is provided as Attachment E to the environmental report.3 10 CFR 51, Subpart A, Appendix B, Table B-1 also identifies 2 issues as "NA" for which NRC could not come to a conclusion regarding categorization.

NextEra Energy Seabrook believes that these issues, chronic effects of electromagnetic fields and environmental justice, do not affect the"coastal zone" as that phrase is defined by the Coastal Zone Management Act [16 USC 1453(1)].Seabrook Station Unit 1 Page E-5 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification 11 apply to Seabrook Station 4 and, like the Category 1 issues, could involve impacts to the coastal zone. The following paragraphs list the applicable Category 2 issues, summarize NextEra Energy Seabrook's conclusions on impacts, and identify the location of more detailed discussion in the NextEra Energy Seabrook environmental report for Seabrook Station license renewal.Entrainment of fish and shellfish in early life stages -This issue addresses mortality of organisms small enough to pass through the plant's cooling water system. Seabrook Station conducts an entrainment monitoring program approved by EPA and New Hampshire Department of Environmental Services (NHDES). The estimated number, by species, of entrained organisms and their adult equivalency are reported annually.

Future proposed changes to the entrainment monitoring program would be subject to approval by EPA and NHDES. EPA determined that the plant's intake structure was Best Available Technology to minimize impact. Section 4.2 contains additional information about this issue. NextEra Energy Seabrook concludes that these impacts are small during current operations and has no plans that would change this conclusion for the license renewal term.Impingement of fish and shellfish

-This issue addresses mortality of organisms large enough to be impinged on the intake screens, precluding passage into the plant equipment.

The studies and permit discussed above also address impingement and Section 4.3 contains additional information about this issue. NextEra Energy Seabrook concludes that these impacts are small during current operations and has no plans that would change this conclusion for the license renewal term.Heat shock -This issue addresses mortality of aquatic organisms by exposure to heated plant effluent.

The Station's NPDES permit provides a Section 316(a) variance based on past and ongoing studies showing no significant impact on the local biological community.

Section 4.4 contains additional information about this issue. NextEra Energy Seabrook concludes that impacts to fish and shellfish from heat shock are small during current operations and has no plans that would change this conclusion for the license renewal term.Threatened or endangered species -This issue addresses effects that Seabrook Station operations could have on species that are listed under federal law as threatened or endangered.

NextEra Energy Seabrook has also addressed state-protected species. Six federally-listed aquatic species, the shortnose sturgeon, the loggerhead turtle, the green turtle, the hawksbill turtle, the Kemp's ridley turtle, and the leatherback turtle, potentially could be 4 The remaining Category 2 issues do not apply to Seabrook Station either because they are associated with design or operational features the Seabrook Station does not have (e.g., circulating water cooling towers) or to an activity, refurbishment, that Seabrook Station will not undertake.

Seabrook Station Unit I Page E-6 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification present in the vicinity of the Station. Station impingement monitoring has never encountered these species and the ecology of these species is unlikely to bring them into contact with the intakes. The habitat on the site and along its transmission corridors is unlikely to be suitable for any of the three federally-listed species known to be present in the four counties included in the project area. Based on the habitat types, a total of 8 vertebrate, 23 plant, and 2 invertebrate species with state threatened or endangered status were identified as potentially present. NextEra Energy Seabrook is unaware of any Station impacts to listed terrestrial species. Agency correspondence indicates that license renewal is unlikely to affect any listed species on the transmission corridors as long as current vegetation management practices and policies are followed.

For these reasons, NextEra Energy Seabrook concludes that impacts to threatened or endangered species are small.NextEra Energy Seabrook has no plans that would change this conclusion for the license renewal term. See Section 4.10 for additional information.

Electromagnetic fields, acute effects (electric shock) -This issue addresses the potential for shock from induced currents, similar to static electricity effects, in the vicinity of'transmission lines (see Section 13). Because this strictly human-health issue does not directly or indirectly affect natural resources of concern within the Coastal Zone Management Act definition of"coastal zone" (16 USC 1453[1]), NextEra Energy Seabrook concludes that the issue is not subject to the certification requirement.

Housing -This issue addresses impacts that additional NextEra Energy Seabrook employees required to support license renewal and the additional concomitant indirect jobs could have on local housing availability (Section 4.14). NextEra Energy Seabrook estimates that no additional workers would be needed to support Seabrook Station operations during the license renewal term. NextEra Energy Seabrook concludes that because there is no increase in staffing, no additional housing would be required and, therefore, the appropriate characterization of Seabrook Station license renewal housing impacts is "small." Public services:

public utilities

-This issue addresses impacts that adding license renewal workers could have on public water supply systems (Section 4.15). NextEra Energy Seabrook estimates that no additional workers would be needed to support Seabrook Station operations during the license renewal term. NextEra Energy Seabrook concludes that because there is no increase in staffing, no additional demands on the public water supply system would be experienced and, therefore, the appropriate characterization of Seabrook Station license renewal impacts is "small." Offsite land use -This issue addresses impacts to land use that could result from a larger worker population and from local government spending of Station property tax dollars in ways that can alter land use patterns.

NextEra Energy Seabrook estimates that no additional workers would be needed to Seabrook Station Unit 1 Page E-7 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification support Seabrook Station operations during the license renewal term, so there would be no offsite land use impacts due to an increased worker population.

Generally, Seabrook Station property taxes comprise too small a percentage of revenues of local governments to cause offsite land use impacts to be other than small, with the possible exception of the Town of Seabrook.

Seabrook Station's property taxes have represented between approximately 30 to 40 percent of the Town of Seabrook's net tax commitment.

However, the annual rate of change of Town of Seabrook land use has been small and is half that of the county, as a whole. NextEra Energy Seabrook concludes that impacts during the Seabrook Station license renewal term would be small. Section 4.17 contains additional information about this issue.Public services:

transportation

-This issue addresses impacts that additional license renewal workers could have on local traffic pattern (Section 4.18).NextEra Energy Seabrook estimates that no additional workers would be needed to support Seabrook Station operations during the license renewal term. NextEra Energy Seabrook concludes that because there is no increase in staffing, no transportation impacts would be experienced and, therefore, the appropriate characterization of Seabrook Station license renewal impacts is "small." Historic and archaeological resources

-This issue addresses impacts that license renewal activities could have on resources of historic or archaeological significance.

NextEra Energy Seabrook is not aware of any historic or archaeological resources that have been affected, to date, by Seabrook Station operations, including operation and maintenance of transmission lines. NextEra Energy Seabrook is aware of the potential for discovery of cultural resources during land-disturbing activities based on the results of pre-operational archaeological exploration.

NextEra is developing procedures to protect any archaeological resources, if discovered, on the Seabrook Station site. NextEra Energy Seabrook has no plans for land-disturbing activities due to license renewal and no other plans due to license renewal that would disturb such resources.

Therefore, NextEra Energy Seabrook concludes that license renewal would not affect historic and archaeological resources.

NextEra Energy Seabrook also has consulted with the New Hampshire State Historic Preservation Officer (SHPO) and the Massachusetts Historical Commission (MHC) SHPO regarding this conclusion for the station and the transmission corridors and the SHPOs in both states have concurred that license renewal and associated operation and maintenance activities would have no effect on historic or archaeological resources.

Severe accidents

-The NRC determined that the license renewal impacts from severe accidents would be small but that applicants who have not previously done so should perform site-specific analyses of ways to further Seabrook Station Unit 1 Page E-8 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification mitigate impacts. NextEra Energy Seabrook used a NRC-approved methodology to conduct a severe accident mitigation alternatives (SAMAs)analysis and found two SAMAs that are potentially cost beneficial for Seabrook Station. Section 4.20 contains additional information about this issue. Because these SAMAs are not age-related, they need not be implemented as part of license renewal. They will be addressed in the Station's Long Range Plan.Coastal Consistency Certification for Seabrook Station License Renewal Previous sections of this certification discussed the environmental impacts of Seabrook Station license renewal. This section addresses how these impacts, and other Seabrook Station activities, comply with New Hampshire Coastal Program requirements.

The New Hampshire Coastal Program website lists 16 coastal zone enforceable policies (Ref. E-7). For each policy, NextEra Energy Seabrook has included in Exhibit E-1 the text of the policy and a discussion of how Seabrook Station license renewal is consistent with the policy. NOAA has published an environmental impact statement (EIS) in conjunction with its approval of the New Hampshire coastal program (Ref. E-8).Findings In summary, the information provided with this certification supports the following findings: New Hampshire has concurred for the original NPDES permit for station operations and for subsequent renewals that Seabrook Station operation is consistent with the federally approved New Hampshire coastal zone management program.The NRC has found that the impacts of certain license renewal environmental issues (i.e., Category 1 issues) are small. NextEra Energy Seabrook has adopted by reference the NRC findings for these issues as they are applicable to Seabrook Station.For other license renewal issues (i.e., Category 2) that are applicable to Seabrook Station, NextEra Energy Seabrook has determined that the environmental impacts are small. Impacts to coastal zone resources, therefore, would also be small.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station and its associated transmission lines and corridors are in compliance with New Hampshire's licensing and permitting requirements and are in compliance with its state-issued licenses and permits.NextEra Energy Seabrook's license renewal and continued operation of Seabrook Station would be consistent with the enforceable policies of the New Hampshire coastal zone management program.Seabrook Station Unit 1 Page E-9 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification STATE NOTIFICATION Upon receipt of a complete consistency certification that Seabrook Station license renewal is consistent with New Hampshire's coastal zone management program, federal regulation gives the State six months in which to concur with or object to the certification

[15 CFR 930.62(a)].

If the State has not issued a decision within three months following the commencement of state agency review, it shall notify the contacts listed below of the status of the matter and the basis for further delay [15 CFR 930.62(b)].

Correspondence concerning the State of New Hampshire's review of this coastal consistency certification should be sent to: Mr. Richard R. Cliche NextEra Energy Seabrook LLC License Renewal Project Manager PO Box 300 Seabrook, NH 03874 Mr. Michael D. O'Keefe NextEra Energy Seabrook LLC Licensing Manager PO Box 300 Seabrook, NH 03874 Seabrook Station Unit 1 License Renewal Application Page E-10 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification REFERENCES E-1 New Hampshire Department of Environmental Services, Water Division, Coastal Program. Website available at http://des.nh.gov/organization/

divisions/water/wmb/coastal/index.htm.

Accessed September 25, 2008.E-2 New Hampshire Coastal Zone. Available at http://des.nh.gov/organization/

divisions/water/wmb/coastal/documents/nhcoastalzonemap.

pdf.Accessed September 25, 2008.E-3 New Hampshire Department of Environmental Services, Water Division, Coastal Program, Federal Consistency.

Website available at http://des.nh.gov/organization/divisions/water/wmb/coastal/federalconsiste ncy.htm. Accessed September 25, 2008.E-4 New Hampshire Coastal Program Guide to Federal Consistency; Coastal Zone Management Act §307. Available online at http://des.nh.gov/

organization/commissioner/pip/publications/wd/documents/wd-05-21 .pdf.Accessed September 25, 2008.E-5 Ocean and Coastal Management in New Hampshire.

Website of National Oceanographic and Atmospheric Administration.

Available online at http://coastalmanagement.noaa.gov/mystate/nh.html.

Accessed September 18, 2008.E-6 Generic Environmental Impact Statement for License Renewal of Nuclear Plants, U. S. Nuclear Regulatory Commission.

NUREG-1437, May 1996.Available online at http:/lwww.nrc.gov/reading-rm/doc-collections/nuregs/

staff/sr1437/.

Accessed September 23, 2008.E-7 Coastal Program Policies.

New Hampshire Department of Environmental Services, Water Division.

Available on http://des.nh.gov/organization/

divisions/water/wmb/coastal/documents/enforceablepolicies.

pdf.Accessed September 25, 2008.E-8 New Hampshire Coastal Program and Final Environmental Impact Statement, U. S. Department of Commerce, National Oceanic and Atmospheric Administration Office of Ocean and Coastal Resource Management, July 1982. Available online at http://des.nh.gov/organization/

divisions/water/wmb/coastal/feis.

htm. Accessed October 3, 2008.E-9 Letter, Piattoni (State of New Hampshire Coastal Program Manager), to DeVincentis (Public Service Company of New Hampshire), July 23, 1985.Seabrook Station Unit 1 License Renewal Application Page E-11 CD a)Cl 0~CD U~0 0) =0 0)CD T Table E-1 Environmental Authorizations for Current Seabrook Station Operation Issue or Expiration Agency Authority Requirement Number Date Activity Covered Federal and State Requirements U.S. Nuclear Regulatory Commission U.S. Environmental Protection Agency, Region 1 U.S. Environmental Protection Agency, Region 1 U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration Town of Seabrook Atomic Energy Act (42 USC 2011, et seq.), 10 CFR 50.10 Clean Water Act (33 USC Section 1251 et seq.)Clean Water Act (33 USC Section 1251 et seq.)49 USC 5108, Transportation registration; 49 CFR 107, Subpart G, Hazardous material shipper/carrier registration Article IV of Municipal Sewer System Ordinance License to operate NPDES Permit NPDES Storm Water Multi-Sector General Permit for Industrial Activities Hazardous Materials Certificate of Registration Permit to Discharge NPF-86 (NRC 2008)NH0020338 (EPA 2002a and Seabrook 2006b)Notice of Intent#NHR05A729 (EPA 2002b)061109 003 01 3RT (USDOT 2009)SEA1 003 (Town of Seabrook 2007b and Town of Seabrook 2010)Issued: 03/15/1990 Expires: 03/15/2030 Issued: 04/01/2002 Expired: 04/01/2007 Renewal application submitted:

09/25/2006 Issued: 9129/2008 Expires: 9/29/2013 Issued: 6/15/2009 Expires: 6/30/2012 Issued: 03/21/2007 Expires: 03/20/2010 Renewal application submitted:

01/18/2010 Operation of Seabrook Station Discharges to Atlantic Ocean from cooling tunnel Storm water Transportation of hazardous materials.

Industrial wastewater discharge to Town's Publically Owned Treatment Works (POTW)0)CD m 0-0 0 =CD X 0'M CD 1 U0)C) CD 00 6' CD CD 0 0;0 CDW~0 0 CD T Cl)Table E-1 Environmental Authorizations for Currenta Seabrook Station Operations (Continued)

Issue or Expiration Agency Authority Requirement Number Date Activity Covered Federal and State Requirements New Hampshire Department of Environmental Services, Waste Management Division New Hampshire Department Environmental Services, Air Resources Division New Hampshire Department Environmental Services, Air Resources Division New Hampshire Department of Environmental Services, Waste Management Division New Hampshire Department of Environmental Services, Waste Management Division New Hampshire Code of Administrative Rules Env-A 1205 Federal Clean Air Act (42 USC 7401), 40 CFR 70, and New Hampshire Code of Administrative Rules, ENV-A 610 Federal Clean Air Act (42 USC 7401), 40 CFR 70, and New Hampshire RSA 125-C New Hampshire Code of Administrative Rules, ENV-WM 300 New Hampshire Code of Administrative Rules, ENV-WM-1400 Certificate of Compliance 021207930308A (NHDES 2008d)Issued: 03/20/2008 Expires:12/11/2010 Stage 1/11 Gasoline Vapor Recovery System Title V General Permit Title V Operating Permit Hazardous Waste Limited Permit Aboveground Storage Tank Registration GSP-EG-225 (NHDES 2008e)TP-OV-01 7 (NHDES 2006)DES-HW-LP 09 (NHDES 2005a)Facility ID#930908A (NHDES 2008f)Issued: 7/2/2008 Expires:04/30/2013 Issued: 06/05/2006 Expires:06/30/2011 Issued: 10/09/2008 Expires: 10/09/2013 Issued: 12/24/2007 Expires: None Air Emissions from Internal Combustion Emergency Generator (EG#1)Air emissions from auxiliary boilers and emergency generators Treatment of hazardous wastewater streams Aboveground tanks 0 CD m C)0 NCDX 0'D CD X CD-I 00 0 r- CO CD a CD 0 CD a)~0 0 CD m Table E-1 Environmental Authorizations for Currenta Seabrook Station Operations (Continued)

Issue or Expiration Agency Authority Requirement Number Date Activity Covered Federal and State Requirements New Hampshire New Hampshire RSA Permit to Display MFD 0801 Issued: 01/04/2010 Display of finfish and Fish and Game 214:29 Finfish and (NHDFG 2010) Expires:12/31/2010 invertebrates at the Department Invertebrates Science and Nature Center Virginia Department Title 44, Code of Registration to FP-S-103110 Issued: 09/17/2008 Registration for of Emergency Virginia, Chapter 3.3, transport radioactive (Virginia 2008) Expires:10/31/2010 transporting Management Section 44-146.30 material radioactive material in Virginia Tennessee Tennessee Code License to deliver T-NH001-L10 Issued: 1/1/2010 License to deliver Department of Annotated 68-202-206 radioactive material (TNDEC 2009) Expires:12/31/2010 radioactive material Environment and to processing facility Conservation in Tennessee Utah Department of Utah Rule 313-26 Permit to deliver 0111000045 Issued: 4/28/2009 Permit to deliver Environmental radioactive material (UTDEQ 2009) Expires:4/28/201 0 radioactive material Quality to disposal facility in Utah NPDES -National Pollutant Discharge Elimination System a Current through March 1, 2010.0 CD 0 03 >NCDX CD X 00 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification Table E-2 Environmental Authorizations for Seabrook Station License Renewal Agency U.S. Nuclear Regulatory Commission U.S. Fish and Wildlife Service Authority Atomic Energy Act (42 USC 2011 et seq.)Endangered Species Act Section 7 (16 USC 1536)Requirement Remarks License renewal Consultation National Marine Fisheries Service New Hampshire Department of Resources and Economic Development New Hampshire Division of Historical Resources Endangered Species Act Section 7 (16 USC 1536)Clean Water Act Section 401 (33 USC 1341)National Historic Preservation Act Section 106 (16 USC 470f)National Historic Preservation Act Section 106 (16 USC 470f)The Federal Coastal Zone Management Act (16 USC 1451)Consultation Certification Consultation Environmental Report submitted in support of license renewal application Requires federal agency issuing a license to consult with the FWS (Attachment C)Requires federal agency issuing a license to consult with the NMFS(Attachment C)Requires State certification that proposed action would comply with Clean Water Act standards (Attachment B)Requires federal agency issuing a license to consider cultural impacts and consult with State Historic Preservation Officer (Attachment D)Requires federal agency issuing a license to consider cultural impacts and consult with State Historic Preservation Officer (Attachment D)Requires the'federal agency issuing the license (NRC) to verify that the State of New Hampshire has determined that renewal of the Seabrook Station operating license would be consistent with the federally approved State Coastal Zone Management program. The applicant (NextEra Energy Seabrook) must request the consistency determination from the NHDES by submitting a certification of consistency for review. (Attachment E)Massachusetts Historical Commission New Hampshire Department of Environmental Services Consultation Coastal Zone Consistency Certification Seabrook Station Unit 1 License Renewal Application Page E-15 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification Seabrook Station Unit 1 License Renewal Application Page E-16 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification Seabrook Station Unit 1 License Renewal Application Page E-17 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification 0 500 1,000 2,000 Feet Legend=1 Site Boundary I Figure E-3 Seabrook Station Site Boundary Seabrook Station Unit 1 License Renewal Application Page E-18 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification Legend A Substation

-30 345 kV Transmission Line-Interstate

= Primary Road SSeabrook Station State Boundary County Boundary Water Urban Area Crane Pond WMA Fsh and Wildlife Service N 0 1 2 4 6 I Mles I Figure E-4 Transmission Line Map I Seabrook Station Unit 1 License Renewal Application Page E-19 Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification EXHIBIT E-1 NEW HAMPSHIRE COASTAL PROGRAM ENFORCEABLE POLICIES PROTECTION OF COASTAL RESOURCES Policy 1. Protect and preserve and, where appropriate, restore the water and related land resources of the coastal and estuarine environments.

The resources of primary concern are coastal and estuarine waters, tidal and freshwater wetlands, beaches, sand dunes, and rocky shores.NextEra Energy Seabrook Response -Applicable.

The Seabrook Station site is composed of a developed area of uplands surrounded by tidal wetlands.

There are no beaches, sand dunes, or rocky shores on the Seabrook Station site. NextEra Energy is not aware of any freshwater wetlands on the site.Seabrook Station withdraws water from and discharges wastewater to the western Gulf of Maine (Atlantic Ocean) and discharges wastewater to the Town of Seabrook municipal wastewater system. The U. S. Environmental Protection Agency (EPA) regulates Station non-radiological discharges to the ocean by means of National Pollutant Discharge Elimination System (NPDES) discharge permits. Stormwater is discharged under an NPDES Multi-Sector General Stormwater Permit. Operation of the Station in accordance with its permits ensures compliance with state water quality standards.

The Town of Seabrook regulates the Station's non-radiological discharges to town's publically-owned treatment works, which also discharges to the Atlantic Ocean, by way of an NPDES permit. The NRC regulates the Station's radiological discharges.

The Station reports discharge water quality to EPA and the State monthly and annually and to the Town biannually, reports water use to the state quarterly, and reports radiological releases annually to the NRC.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with its permits and with Policy 1. NextEra Energy Seabrook has no plans that would alter this status due to license renewal.Transmission lines connecting Seabrook Station to the grid are owned by FPL New England Division, Public Service of New Hampshire and National Grid.To the best of NextEra Energy Seabrook's knowledge these corridors are maintained in accordance with all state (New Hampshire and Massachusetts) requirements.

Policy 2. Manage, conserve and, where appropriate, undertake measures to maintain, restore, and enhance the fish and wildlife resources of the state.NextEra Energy Seabrook Response -Applicable.

EPA regulates Station impacts to fish resources by means of the Station's NPDES permit. EPA, in issuing the permit, concluded that the Station's cooling water intake structure employs the best technology available for minimizing adverse environmental Seabrook Station Unit 1 Page E-20 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification impact and that biological monitoring will continue to assure the EPA and the State that the continued operations of Seabrook Station do not significantly impact the local biological community.

The fish and shellfish communities in the vicinity of Seabrook Station have been studied extensively since 1969. Monitoring for most communities or species began in the late 1970s or early 1980s and provides approximately 10 years of preoperational data and, as of 2008, 18 years of operational data including impingement and entrainment data. The station provides annual reports on these studies to EPA, NOAA, and the State.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with its permit and with Policy 2. NextEra Energy Seabrook has no plans that would alter this status due to license renewal.Policy 3. Regulate the mining of sand and gravel resources in offshore and onshore locations so as to ensure protection of submerged lands, and marine and estuarine life. Ensure adherence to minimum standards for restoring natural resources impacted from onshore sand and gravel removal operations.

NextEra Energy Seabrook Response -Not applicable.

Seabrook Station has no plans to engage in mining of sand or gravel due to license renewal.Other than excavations associated with plant construction, there are no onsite locations of previous sand or gravel mining operations.

Seabrook Station has plans to remove, from an onsite upland area, spoils material deposited during the excavation of the intake and discharge tunnels. Seabrook Station is requiring the contractor to conduct the removal in accordance with state wetlands protection regulations, obtain appropriate permits, and control runoff so as to protect state waters and wetlands.Policy 4. Undertake oil spill prevention measures, safe oil handling procedures and, when necessary, expedite the cleanup of oil spillage that will contaminate public waters. Institute legal action to collect damages from liable parties in accordance with state law.NextEra Energy Seabrook Response -Applicable, in part. Seabrook Station maintains a Spill Prevention, Control, and Countermeasures Plan that documents Station response to spillage as required by EPA regulation 40 CFR 112. NextEra Energy Seabrook concludes that the Policy 4 provision regarding instituting legal action is applicable to the State and not to NextEra Energy Seabrook.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 4 and NextEra Energy Seabrook has no plans that would alter this status due to license renewal.Seabrook Station Unit 1 Page E-21 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification Policy 5. Encourage investigations of the distribution, habitat needs, and limiting factors of rare and endangered animal species and undertake conservation programs to ensure their continued perpetuation.

NextEra Energy Seabrook Response -Not applicable.

NextEra Energy Seabrook concludes that this policy is applicable to state agencies.

See below regarding onsite species.Policy 6. Identify, designate, and preserve unique and rare plant and animal species and geologic formations which constitute the natural heritage of the state. Encourage measures, including acquisition strategies, to ensure their protection.

NextEra Energy Seabrook Response -Applicable.

NextEra Energy Seabrook reports annually on Station monitoring of aquatic marine animals in the vicinity.

One listed aquatic species, the shortnose sturgeon, has the potential to exist in the vicinity of the Seabrook Station but 18 years of operational monitoring have found no occurrence of this species. Seabrook Station has made design modifications to eliminate takes of seals.NextEra Energy Seabrook has no records of Federal- or state-listed plant or animal species resident on the Seabrook Station site. Review of site habitats and the habitat requirements of species known to exist in the county has shown that such residency is unlikely.

The site could be used for foraging by non-resident bird species but station operations are unlikely to affect adversely this behavior and NextEra Energy Seabrook has no record of this occurring.

NextEra Energy Seabrook is not aware of unique or rare geologic formation on the Seabrook Station site.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 6. NextEra Energy Seabrook has no plans that would alter this status due to license renewal.As indicated in response to Policy 1, NextEra Energy Seabrook does not own the transmission lines that connect the station to the grid. To the best of NextEra Energy Seabrook's knowledge these corridors are maintained in accordance with all state requirements.

RECREATION AND PUBLIC ACCESS Policy 7. Provide a wide range of outdoor recreational opportunities including public access in the seacoast through the maintenance and improvement of the existing public facilities and the acquisition and development of new recreational areas and public access.NextEra Energy Seabrook Response -Applicable, in part. There are no public facilities onsite except for the Seabrook Station Science and Nature Center, which is open to the public (security considerations may preclude public access). The center offers more than 30 interactive educational Seabrook Station Unit I Page E-22 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification exhibits, most of which are hands-on and focus on nuclear energy and the ecosystem surrounding the plant. Two of the exhibits feature live marine life.The visitor's center is surrounded by the Owascoag Nature Trail, a nearly one-mile boardwalk and trail for viewing the marsh and woodland habitats.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 7. NextEra Energy Seabrook has no plans that would alter this status due to license renewal.MANAGING COASTAL DEVELOPMENT Policy 8. Preserve the rural character and scenic beauty of the Great Bay estuary by limiting public investment in infrastructure within the coastal zone in order to limit development to a mixture of low and moderate density.NextEra Energy Seabrook Response -Not applicable.

NextEra Energy Seabrook concludes that this policy is applicable to state agencies'management of development in the Great Bay Estuary. Seabrook Station operates with current established infrastructure.

License renewal would not alter this status.Policy 9. Reduce the risk of flood loss, to minimize the impact of floods on human safety, health and welfare, and to preserve the natural and beneficial value of floodplains, through the implementation of the National Flood Insurance Program and applicable state laws and regulations, and local building codes and zoning ordinances.

NextEra Energy Seabrook Response -Applicable.

Approximately 600 acres of the 889-acre site are undeveloped salt marsh which provide buffer for flood events. The developed portion of the site is located above the 0.2 percent annual chance floodplain (500-year flood). The station was constructed in the late '70s and early '80's in accordance with applicable state laws and regulations and remains in compliance with local building codes and zoning ordinances.

To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 9 and NextEra Energy Seabrook has no plans that would alter this status due to license renewal.Policy 10. Maintain the air resources in the coastal area by ensuring that the ambient air pollution level, established by the New Hampshire State Implementation Plan pursuant to the Clean Air Act, as amended, is not exceeded.NextEra Energy Seabrook Response -Applicable.

As shown in Table E-1, Seabrook Station has several small air emission sources subject to a Clean Air Act Title V Permit issued by NHDES. The station maintains records and provides annual reports to the State in accordance with the permit.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations will be in conformance with its permits and Policy 10 and any Seabrook Station Unit 1 Page E-23 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification instance of non-compliance will be corrected in a timely manner. NextEra Energy Seabrook has no plans that would alter this status due to license renewal and has no plans for additional site development due to license renewal.Policy 11. Protect and preserve the chemical, physical, and biological integrity of coastal water resources, both surface and groundwater.

NextEra Energy Seabrook Response -Applicable.

See response to Policies 1 and 2 regarding Seabrook Station impacts to surface water and aquatic resources.

Other than limited dewatering of groundwater leakage into buildings, Seabrook Station does not withdraw from or discharge to groundwater.

To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with its permits and Policy 11. NextEra Energy Seabrook has no plans that would alter this status due to license renewal and has no plans for additional site development due to license renewal.Policy 12. Ensure that the siting of any proposed energy facility in the coast will consider the national interest and will not unduly interfere with the orderly development of the region and will not have an unreasonable adverse impact on aesthetics, historic sites, coastal and estuarine waters, air and water quality, the natural environment and the public health and safety.NextEra Energy Seabrook Response -Not applicable.

Seabrook Station is an existing, not a proposed, energy facility.

The New Hampshire programmatic coastal documentation acknowledges Seabrook Station existence and the processes that were available to the State to evaluate the siting of the Station. Seabrook Station has operated consistent with this policy for 20 years. The license renewal and continued operation will not alter this status.COASTAL DEPENDENT USES Policy 13. Allow only water dependent uses and structures on state properties in Portsmouth-Little Harbor, Rye Harbor, and Hampton-Seabrook Harbor, at state port and fish pier facilities and state beaches (except those uses or structures which directly support the public recreation purpose).

For new development, allow only water dependent uses and structures over waters and wetlands of the state. Allow repair of existing over-water structures within guidelines.

Encourage the siting of water dependent uses adjacent to public waters.NextEra Energy Seabrook Response -Applicability assumed. While Seabrook Station is not located on state property, its intake and discharge pipelines pass beneath Hampton Harbor and its submerged intake and discharge structures are present in offshore waters of the state.Documentation for the New Hampshire Coastal Program indicates that water Seabrook Station Unit 1 Page E-24 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification pipelines for electric generating plants located back from the shoreline are water dependent uses. Other than a publicly accessible interpretive nature trail, Seabrook Station has no over-water structures.

To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 13. NextEra Energy Seabrook has no plans that would alter this status due to license renewal and has no plans for additional site development due to license renewal.Policy 14. Preserve and protect coastal and tidal waters and fish and wildlife resources from adverse effects of dredging and dredge disposal, while ensuring the availability of navigable waters to coastal-dependent uses.Encourage beach renourishment and wildlife habitat restoration as a means of dredge disposal whenever compatible.

NextEra Energy Seabrook Response -Not applicable.

Seabrook Station does not foresee a need to perform dredging or dredge disposal and NextEra Energy Seabrook has no plans that would alter this status due to license renewal.PRESERVATION OF HISTORIC AND CULTURAL RESOURCES Policy 15. Support the preservation, management, and interpretation of historic and culturally significant structures, sites and districts along the Atlantic coast and in the Great Bay area.NextEra Energy Seabrook Response -Applicable.

There are national, state, and locally-designated historic resources located within 6 miles of the Station, however, none are adjacent to or within the Station property.NextEra Energy Seabrook knows of two archaeological resources on the site but is not aware of any historic or archaeological resources that have been affected by Seabrook Station operations, including operation and maintenance of transmission lines. Because NextEra Energy Seabrook is aware of the potential for discovery of cultural resources during land-disturbing activities at its facilities, it is developing procedures that would protect archaeological resources and that address discovery of cultural resources on the Seabrook Station site. The New Hampshire and Massachusetts SHPOs have concurred that license renewal and associated operation and maintenance activities would have no effect on historic or archaeological resources.

To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 15. NextEra Energy Seabrook has no plans that would alter this status due to license renewal and has no plans for additional site development due to license renewal.As indicated in response to Policy 1, NextEra Energy Seabrook does not own the transmission lines that connect the station to the grid. To the best of NextEra Energy Seabrook's knowledge these corridors are maintained in Seabrook Station Unit I Page E-25 License Renewal Application Appendix E -Environmental Report Attachment E Coastal Zone Consistency Certification accordance with all state requirements.

The transmission lines are critical to the ISO-NE system and would remain, regardless of license renewal.MARINE AND ESTUARINE RESEARCH AND EDUCATION Policy 16. Promote and support marine and estuarine research and education that will directly benefit coastal resource management.

NextEra Energy Seabrook Response -Applicable.

The fish and shellfish communities in the vicinity of Seabrook Station have been monitored extensively since 1969. Monitoring for most communities or species began in the late 1970s or early 1980s and provides approximately 10 years of preoperational data and, as of 2008, 18 years of operational data including impingement and entrainment data. The station provides annual reports on these studies to EPA and the State. The Seabrook Station Science and Nature Center is open to the public. The center offers more than 30 interactive educational exhibits, most of which are hands on and focus on nuclear energy and the ecosystem surrounding the plant. Two of the exhibits feature live marine life. The visitor's center is surrounded by the Owascoag Nature Trail, a nearly one-mile boardwalk and trail for viewing the marsh and woodland habitats.To the best of NextEra Energy Seabrook's knowledge, Seabrook Station operations are in conformance with Policy 16. NextEra Energy Seabrook has no plans that would alter this status due to license renewal.Seabrook Station Unit 1 License Renewal Application Page E-26 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives ATTACHMENT F SEVERE ACCIDENT MITIGATION ALTERNATIVES Seabrook Station Unit 1 License Renewal Application Page F-1 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives SEABROOK STATION SAMA ANALYSIS EXECUTIVE

SUMMARY

This attachment provides an analysis of the Severe Accident Mitigation Alternatives (SAMAs) that were identified for consideration by Seabrook Station. The analysis was conducted on a cost-benefit basis. The benefit results are in Section F.4 of this report. Candidate SAMAs that do not have benefit evaluations have been eliminated from further consideration for any of the following reasons: " The cost is considered excessive compared with benefits..The improvement is not applicable to Seabrook Station." The improvement has already been implemented at Seabrook Station or the intent of the improvement has been met at Seabrook Station.After eliminating the SAMAs that met one of the preceding reasons, the remaining SAMAs are evaluated from a cost-benefit perspective.

In general, the SAMA analyses use a bounding approach to determine whether the expected cost would exceed a conservative approximation of the expected benefit. In most cases, therefore, a detailed risk evaluation of a specific modification or procedure change would indicate a smaller benefit than calculated in this bounding analysis.Major insights from this benefit evaluation process include the following:

.If all core-damage risk is eliminated, then the benefit in dollars over 20 years is $818,721.The largest contributors to the total benefit estimate are offsite dose savings and offsite property costs.Many of the SAMAs had already been addressed by existing plant features, modifications to improve the plant or existing procedures, or procedure changes to enhance human performance.

Two SAMAs were identified as potentially cost-beneficial and are described in the following table.Seabrook SAMA Number Potential Improvement Discussion 157 Provide independent AC power source for Reduce core-damage frequency of long-term battery chargers -example: provide portable station blackout sequences; extend battery generator to charge station battery. life to allow additional time for recovery of offsite power.165 Reactor water storage tank fill from firewater Could enhance long term containment during containment injection

-modify 6" injection sequences that would benefit from Reactor water storage tank flush flange to reactor water storage tank makeup.have a 21/2-inch female fire hose adapter with Installing permanent valve connection would isolation valve improve alignment efficiency.

Seabrook Station Unit 1 Page F-2 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives TABLE OF CONTENTS Section Page EXEC UTIV E SUM M A RY ...................................................................................

F-2 A C R O N Y M S ......................................................................................................

F-6 F.1 IN T R O D U C T IO N ................................................................................

F-9 F .1.1 P U R P O S E ....................................................................................

F-9 F.1.2 R EQ U IR EM ENTS .........................................................................

F-9 F .2 M E T H O D ............................................................................................

F-9 F.3 SEVERE ACCIDENT RISK ..........................................................

F-11 F.3.1 LEVEL 1 PRA M O DEL ...............................................................

F-12 F.3.1.1 INTERNAL EVENTS ...........................................................

F-12 F.3.1.2 EXTERNAL EVENTS ..........................................................

F-28 F.3.2 LEVEL 2 PLANT SPECIFIC MODEL ...........................................

F-30 F.3.

2.1 DESCRIPTION

OF LEVEL 2 PRA MODEL .........................

F-31 F.3.2.2 LEVEL 2 PRA MODEL CHANGES SINCE IPE S U B M ITT A L .......................................................................

F-36 F.3.3 MODEL REVIEW

SUMMARY

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F-36 F.3.4 LEVEL 3 PRA M O DEL ...............................................................

F-52 F.3.4.1 POPULATION DISTRIBUTION

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F-52 F.3.4.2 ECO NO M IC DATA ..............................................................

F-58 F.3.4.3 NUCLIDE RELEASE ...........................................................

F-58 F.3.4.4 EMERGENCY RESPONSE ................................................

F-64 F.3.4.5 METEOROLOGICAL DATA ................................................

F-64 F.4 COST OF SEVERE ACCIDENT RISK / MAXIMUM BENEFIT .........

F-65 F.4.1 OFF.SITE EXPOSURE COST ...................................................

F-66 F.4.2 OFF.SITE ECONOMIC COST ....................................................

F-66 F.4.3 ON-SITE EXPOSURE COST .....................................................

F-67 F.4.4 ON-SITE ECONOMIC COST .....................................................

F-68 F.4.5 TOTAL COST OF SEVERE ACCIDENT RISK / MAXIMUM B E N E F IT ....................................................................................

F-7 1 F.5 SAM A IDENTIFICATIO N ..................................................................

F-71 F.5.1 PRA IM PO RTA NCE ...................................................................

F-71 F.5.2 P LA N T IP E .................................................................................

F-72 F.5.3 P LA NT IP E E E ............................................................................

F-72 F.5.4 INDUSTRY SAMA CANDIDATES

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F-72 F.5.5 PLANT STAFF INPUT TO SAMA CANDIDATES

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F-72 F.5.6 LIST OF PHASE I SAMA CANDIDATES

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F-73 F.6 PHASE I A NA LYS IS .........................................................................

F-96 F.7 PHASE II SAMA ANALYSIS ...........................................................

F-125 F.7.1 SA M A BEN EFIT .......................................................................

F-125 Seabrook Station Unit 1 Page F-3 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives TABLE OF CONTENTS (CONTINUED)

Section Paqe F.7.1.1 SEVERE ACCIDENT RISK WITH SAMA IM PLEM ENTED ...............................................................

F-125 F.7.1.2 COST OF SEVERE ACCIDENT RISK WITH SAMA IM PLEM ENTED ...............................................................

F-126 F.7.1.3 SAMA BENEFIT CALCULATION

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F-126 F.7.2 COST OF SAMA IMPLEMENTATION

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F-126 F.8 SENSITIVITY ANALYSES ..............................................................

F-1 58 F.8.1 PLANT MODIFICATIONS

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F-158 F.8.2 U NC ERTA INTY ........................................................................

F-158 F.8.3 PEER REVIEW FACTS/OBSERVATIONS

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F-158 F.8.4 SENSITIVITY TO LEVEL 3 OFFSITE PARAMETERS

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F-158 F.8.5 REAL DISCOUNT RATE ..........................................................

F-160 F.8.6 A NALYSIS PERIO D .................................................................

F-161 F.9 C O N C LU S IO N S ..............................................................................

F-186 F.10 R E FE R E N C ES ...............................................................................

F-188 APPENDIX F.A PRA CASE DESCRIPTIONS FOR SELECTED SA M A C A S ES ...................................................................

F-A -1 Seabrook Station Unit 1 License Renewal Application Page F-4 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives TABLE OF CONTENTS (CONTINUED)

LIST OF TABLES Table F.3.1.1.1.-1 F.3.11.1-2 F. 3.2.1-1 F.3.2.1-2 F.3.4.1-1 F.3.4.3-1 F.3.4.3-2 F.5.6-1 F.6-1 F.7-1 F.8-1 F.9-1 PaQe Dominant Initiating Event Contribution to Core Damage ...........

F-14 Top Basic Events by Risk Reduction Worth ..............................

F-16 Release Category Bin Definition

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F-33 Basic Event Importances for Total Plant LERF by Risk R eduction W orth ........................................................................

F-34 Population Projections Used in SAMA Analysis ........................

F-53 C ore Inventory

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F-60 Accident Category Frequencies and Release Fractions

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F-63 List of SAMA Candidates

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F-74 Seabrook Station Phase 1 SAMA Analysis ...............................

F-97 Seabrook Station 1 Phase II SAMA Analysis ..........................

F-128 Seabrook Station Sensitivity Evaluation

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F-1 62 Seabrook Station Potentially Cost Beneficial SAMAs ..............

F-187 Seabrook Station Unit 1 License Renewal Application Page F-5 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives ACRONYMS AFW Auxiliary Feedwater ALT Alternate Cooling Modification AMSAC ATWS Mitigation System Actuation Circuitry AOT Allowed Outage Time AOV Air Operated Valve ATWS Anticipated Transient Without Scram CCF Common Cause Failure CCW Component Cooling Water CDF Core Damage Frequency CET Containment Event Tree Cl Containment Isolation CR Control Rod CST Condensate Storage Tank CT Cooling Tower DCH Direct Containment Heating ECCS Emergency Core Cooling System EDG Emergency Diesel Generator EPRI Electric Power Research Institute EFW Emergency Feedwater System EOP Emergency Operating Procedure EPZ Emergency Planning Zone FB Feed and Bleed F-V Fussel-Vesely Importance FSAR Final Safety Analysis Report GDC General Design Criterion HEP Human Error Probability HPI High Pressure Injection HPCI High Pressure Coolant Injection HRA Human Reliability Analysis IPE Individual Plant Examination IPEEE Individual Plant Examination External Events ISGTR Induced Steam Generator tube Rupture , ISLOCA Interfacing System Loss of Coolant Accident IST In-Service Test LERF Large Early Release Frequency LOCA Loss of Coolant Accident LOSP Loss of Offsite Power LPCI Low Pressure Coolant Injection Seabrook Station Unit 1 Page F-6 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives ACRONYMS (CONTINUED)

MAAP Modular Accident Analysis Progression MG Motor Generator MLOCA Medium Loss of Coolant Accident MOV Motor Operated Valve MSIV Main Steam Isolation Valve NOP Normal Operating Pressure NOT Normal Operating Temperature NRC Nuclear Regulatory Commission PCC Primary Closed Cooling PCCW Primary Component Cooling Water PDP Positive Displacement Pump PDS Plant Damage State PORV Power Operated Relief Valve PRA Probabilistic Risk Analysis PSNH Public Service of New Hampshire PSF Performance Shaping Factor PWR Pressurized Water Reactor RAT Reserve Auxiliary Transformer RAW Risk Achievement Worth RCP Reactor Coolant Pump RCS Reactor Coolant System RHR Residual Heat Removal RNO Response Not Obtained RRW Risk Reduction Worth RWST Reactor Water Storage Tank SAMA Severe Accident Mitigation Alternatives SBO Station Blackout SCC Secondary Component Cooling SEPS Supplemental Electric Power System SER Safety Evaluation Report SG Steam Generator SGTR Steam Generator Tube Rupture SI Safety Injection SLOCA Small Loss of Coolant Accident SRP Standard Review Plan SSPSS Seabrook Station Probabilistic Safety Study STCP Source Term Code Package SUFP Startup Feed Pump Seabrook Station Unit 1 Page F-7 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives ACRONYMS (CONTINUED)

Sv Seivert SW Service Water SWGR Switchgear SWS Service Water System TCA Time Critical Activity TDAFW Turbine-driven Auxiliary Feedwater UAT Unit Auxiliary Transformer UB Upper bound UFSAR Updated Final Safety Analysis Report Seabrook Station Unit 1 License Renewal Application Page F-8 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives FA INTRODUCTION FA1.1 PURPOSE The purpose of the analysis is to identify Severe Accident Mitigation Alternative (SAMA) candidates at Seabrook Station that have the potential to reduce severe accident risks and to determine whether implementation of the individual SAMA candidate would be cost-beneficial.

NRC license renewal environmental regulations require a SAMA evaluation.

F.1.2 REQUIREMENTS 10 CFR 51.53(c)(3)(ii)(L)

The environmental report must contain a consideration of alternatives to mitigate severe accidents

"...if the staff has not previously considered severe accident mitigation alternatives for the applicant's plant in an environmental impact statement or related supplement or in an environment assessment..." 10 CFR 51, Subpart A, Appendix B, Table B-I, Issue 76"...The probability weighted consequences of atmospheric releases, fallout onto open bodies of water, releases to ground water, and societal and economic impacts from severe accidents are small for all plants. However, alternatives to mitigate severe accidents must be considered for all plants that have not considered such alternatives...." F.2 METHOD The SAMA analysis approach applied in the Seabrook Station assessment consists of the following steps: Determine Severe Accident Risk Level I and 2 Probabilistic Risk Assessment (PRA) Model The Seabrook Station PRA model (Section 3.1 -3.2) was used as input to the Seabrook Station Level 3 PRA analysis (Section F.3.4).The PRA results include the risk from internal and external events. The external hazards evaluated are internal fires, external floods, and seismic events only. High winds and tornadoes, and transportation and nearby facility accidents are not included in the results because they were screened from the IPEEE submittal because their individual CDF fell below the cutoff criterion of 1.OE-06 per year.Level 3 PRA Analysis The Level 1 and 2 PRA output and site-specific meteorological, demographic, land use, and emergency response data were used as input for the Seabrook Station Level 3 PRA (Section F.3). This combined model was used to estimate the severe accident risk (i.e., off-site dose and economic impacts of Seabrook Station Unit 1 Page F-9 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives a severe accident).

The NRC regulatory analysis techniques to estimate the cost of severe accident risks were used throughout this analysis.Determine Cost of Severe Accident Risk I Maximum Benefit In this step the NRC regulatory analysis techniques were used to estimate the maximum benefit that a SAMA could achieve if it eliminated all risk (i.e., the maximum benefit) (Section F.4).SAMA Identification In this step potential SAMA candidates (plant enhancements that reduce the likelihood of core damage and/or reduce releases from containment) were identified by Seabrook Station plant staff, from the PRA model, Individual Plant Examination (IPE) and IPE -External Events (IPEEE)recommendations, and industry documentation (Section F.5). The process included consideration of the PRA importance analysis because it has been demonstrated by past SAMA analyses that SAMA candidates are not likely to prove cost-beneficial if they only mitigate the consequences of events that present a low risk to the plant.Preliminary Screening (Phase I SAMA Analysis)Because many of the SAMA candidates identified in the previous step are from the industry, it was necessary to screen out SAMA candidates that were not applicable to the Seabrook design, that had already been implemented or whose benefits had been achieved at the plant using other means, and whose roughly estimated cost exceeded the maximum benefit. Additionally, PRA importance measures were used directly to screen SAMA candidates that did not address significant contributors to risk in this phase (Section F.6).Final Screening (Phase II SAMA Analysis)In this step of the analysis, the benefit of severe accident risk reduction was estimated for each of the remaining SAMA candidates and compared to an implementation cost estimate to determine net cost-benefit (Section F.7). The benefit associated with each SAMA was determined as the reduction in severe accident risk from the baseline and was derived by modifying the plant model to represent the plant after implementing the candidate.

In general, the approach was to first determine a bounding value of the benefit. If the bounding value of the benefit was determined to be smaller than the expected cost, no further modeling was necessary.

If the bounding value of the benefit was greater than the estimated cost, the conservatism in the model was removed and a less conservative benefit was determined for comparison with the estimated cost.Seabrook Station Unit 1 Page F-10 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives The initial cost estimate used in this analysis was determined with input from an expert panel (plant staff familiar with design, construction, operation, training and maintenance).

All costs associated with a SAMA were considered, including design, engineering, safety analysis, installation and long-term maintenance, calibration, training, etc. If the estimated cost was close to the estimated benefit, the benefit evaluation was refined to remove conservatism, and if the estimated cost and benefit were still close, then the cost estimate was refined to assure that both the benefit calculation and the cost estimate were sufficiently accurate to justify further decision-making using the estimates.

Sensitivity Analysis The sensitivity analysis evaluated the impact on the cost-benefit analysis of changes in SAMA analysis assumptions and uncertainties (Section F.8).Identify Conclusions The final step involved summarizing the results and conclusions (Section F.9).F.3 SEVERE ACCIDENT RISK The Seabrook Station PRA models describe the results of the first two levels of the Seabrook probabilistic risk assessment.

Level 1 determines core damage frequency (CDF) based on system analyses and human reliability assessments.

Level 2 evaluates the impact of severe accident phenomena on radiological releases and quantifies the condition of the containment and the characteristics of.the release of fission products to the environment.

The Seabrook Station models use PRA techniques to: " Understand severe accident behavior;" Understand the most likely severe accident consequences;" Understand quantitatively the overall probabilities of core damage and fission product releases; and" Evaluate hardware and procedure changes to assess the overall probabilities of core damage and fission product releases.The PRA was initiated in response to Generic Letter 88-20, which resulted in an IPE and IPEEE analysis.

The current model includes both internal and external initiating events (i.e., it consolidates IPE and IPEEE studies into a single PRA model) for power operation.

This means that severe accident sequences have been developed from internally-and externally-initiated events, including internal floods, internal fires, external floods, and seismic events.Seabrook Station Unit 1 Page F-11 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives The PRA models are described in the following section. The Level 1 PRA model (internal and external), the Level 2 PRA model, PRA model review history, and the Level 3 PRA model, are described in Sections F.3.1, F.3.2 and F.3.4.F.3.1 LEVEL I PRA MODEL F.3.1.1 INTERNAL EVENTS F.3.1.1.1 Description of Level 1 Internal Events PRA Model The NRC issued Generic Letter No. 88-20, in December 1988, which requested each plant to perform an IPE of internal events to identify any vulnerabilities.

In response, New Hampshire Yankee submitted an IPE report (Reference

1) using a probabilistic risk assessment (PRA) approach for Seabrook Station in March 1991 that examined risk from internal events, including internal flooding.The 2006 updated PRA model is the base model used to support the SAMA analysis.

The Level 1 PRA models internal and external initiating events.The software used to quantify the PRA model is RISKMAN. The Level 1 PRA presents the risk associated with core damage. Core damage is defined as the uncovering and heatup of the reactor core to the point where prolonged cladding oxidation and severe fuel damage is anticipated.

This condition is defined as the maximum fuel clad temperature exceeding 1100'F for an extended period of time, e.g. > 10 minutes.The Seabrook Station internal and external events baseline, at power CDF, is calculated to be 1.44E-05 per year. The fault tree method of quantification is binary decision diagram quantification, which provides an exact solution for split fraction values. The event tree quantification was calculated using a truncation cut-off frequency of 1.OE-14, or more than 8 orders of magnitude below the baseline CDF. The results of the CDF quantification of risk from internal and external events is summarized in Table F.3.1.1.1-1 (Dominant Initiating Event Contribution to Core Damage) and Table F.3.1.1.1-2 (Top Basic Events by Risk Reduction Worth). The approximate CDF contributions from Anticipated Transients Without Scram (ATWS) and Station Blackout (SBO) events are presented below for information purposes.Contribution to Internal CDF (per year)ATWS -4.6E-07 SBO -5.3E-06 The Seabrook Station PRA was initially developed in 1983 to provide a Level 3 baseline risk assessment to help support establishment of the station's EPZ. Since 1983 the PRA model has undergone periodic update and was used to support the IPE and IPEEE. The PRA model underwent certification peer review in 1999. A focused peer review of the PRA was performed in Seabrook Station Unit 1 License Renewal Application Page F-12 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives 2005. PRA model SSPSS-2006 is the model-of record used to support the SAMA evaluation.

A summary of the entire PRA update history is provided in Section F.3.1.1.2, Level 1 and 2 PRA Model Changes. The peer review summary is provided in Section F.3.3, Model Review Summary.Seabrook Station Unit 1 License Renewal Application Page F-13 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.1.1.1-1 Dominant Initiating Event Contribution to Core Damage Initiating Cumulative Event Contribution Percent Percent of Initiator Description Frequency to CDF of CDF CDF LOSPW Loss of Off-Site Power due to Weather 6.70E-03 1.45E-06 10.00% 10.00%-Modes 1, 2, 3 RXT1 Reactor Trip -Condenser Available 1.17E+00 9.27E-07 6.40% 16.40%E7T Seismic 0.7g Transient Event 9.30E-06 9.22E-07 6.30% 22.70%LOSPG Loss of Off-Site Power due to Grid- 1.00E-02 8.95E-07 6.20% 28.90%Related Events -Modes 1, 2, 3 E10T Seismic 1.0g Transient Event 1.77E-06 8.65E-07 5.90% 34.80%LOSPIP Loss of Off-Site Power due to Hardware .07E-02 8.11 E-07 5.60% 40.40%or Maintenance

-Modes 1, 2, 3 FLLP Flood in Turbine Building -LOSP 8.71 E-04 6.17E-07 4.20% 44.60%LACPB Loss of Train B Essential AC Power 4.97E-03 6.02E-07 4.10% 48.70%(4kV Bus E6)SGTR Steam Generator Tube Rupture 3.69E-03 5.88E-07 4.00% 52.70%FSGBE6 Fire SWGR Room B -Loss of Bus E6 1.OOE-03 3.72E-07 2.60% 55.30%FSGAE5 Fire in SWGR Room A -Loss of E5 1.10E-03 3.66E-07 2.50% 57.80%E14T Seismic 1.4g Transient Event 6.OOE-07 3.61E-07 2.50% 60.30%LACPA Loss of Train A Essential AC Power 4.96E-03 3.51 E-07 2.40% 62.70%(4kV Bus E5)LOC1VS Interfacing Systems LOCA, RHR 3.28E-06 3.40E-07 2.30% 65.00%Suction Valves Failure -Modes 1, 2, 3 LOC1LG Large LOCA -at NOT/NOP 7.20E-06 3.38E-07 2.30% 67.30%LOClMD Medium LOCA- at NOT/NOP 6.13E-05 3.32E-07 2.30% 69.60%LPCCA Loss of Train A Primary Component 1.31 E-02 2.67E-07 1.80% 71.40%Cooling System -Modes 1, 2, 3 LPCCB Loss of Train B Primary Component 1.31 E-02 2.66E-07 1.80% 73.20%Cooling System -Modes 1, 2, 3 LOCI EX Excessive LOCA -at NOT/NOP 2.66E-07 2.50E-07 1.70% 74.90%ISI Inadvertent Safety Injection 2.81E-02 2.47E-07 1.70% 76.60%LDCPB Loss of Train B Essential DC Power 4.41 E-03 2.47E-07 1.70% 78.30%(125Vdc Bus 11B)RXT2SD Reactor Trip -During Shutdown from 7.83E+01 2.13E-07 1.50% 79.80%20% to 0% (Manual Secondary Control)FCRAC Fire in Control Room -AC Power Loss 9.11 E-07 2.12E-07 1.50% 81.30%LOClSM Small LOCA- above 300 psig 1.62E-03 1.86E-07 1.30% 82.60%RXT1 NC Reactor Trip with No Condenser 1.48E-01 1.72E-07 1.20% 83.80%Cooling LDCPA Loss of Train A Essential DC Power 4.41E-03 1.41E-07 1.00% 84.80%(125Vdc Bus 11 A)FCRPL Fire in Control Room -PORV/LOCA 4.51E-05 1.41E-07 1.00% 85.80%Seabrook Station Unit 1 License Renewal Application Page F-14 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.1.1.1-1 Dominant Initiating Event Contribution to Core Damage (Continued)

Initiating Cumulative Event Contribution Percent Percent of Initiator Description Frequency to CDF of CDF CDF RXT1SD Reactor Trip -During Shutdown from 8.03E+01 1.40E-07 1.00% 86.80%70% to 20% (Auto Secondary Control)E10A Seismic 1.0g ATWS 1.77E-06 1.14E-07 0.80% 87.60%FL2SG Flood in Turbine Building -LOSP and 1.20E-07 1.13E-07 0.80% 88.40%Loss of Both Vital Switchgear Rooms E14L Seismic 1.4g Large LOCA 6.00E-07 1.11E-07 0.80% 89.20%E7A Seismic 0.7g ATWS 9.30E-06 1.04E-07 0.70% 89.90%E10L Seismic 1.0g Large LOCA 1.77E-06 8.91E-08 0.60% 90.50%Seabrook Station Unit 1 License Renewal Application Page F-15 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.1.1.1-2 Top Basic Events by Risk Reduction Worth Associated Basic Event Basic Event Description RRW SAMA Feedwater

&FWP37A.FR Turbine Driven PUMP FW-P-37A fails to run 1.1713 Condensate SAMAs AC Power DGDG1A.FR3 DG-1A fails to run for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.0774 A MP s SAMAs AC Power DGDG1B.FR3 DG-1B fails to run for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.0694 A MP s SAMAs AC Power EDESWG6.FX 4KV BUS E6 fault 1.0442 A oe SAMAs AC Power ZZ.SY1 .FX Loss of Offsite Power subsequent to plant trip 1.0391 A oe SAMAs ZZ.SY2.FX Loss of Offsite Power subsequent to LOCA initiator 1.0387 AMP s SAMAs Feedwater

&FWP37A.FS1 Turbine Driven Pump TURBINE FW-P-37A fails to 1.0376 Condensate start on demand SAMAs AC Power SEPSDG2A.FR3 1-SEPS-DG-2-B fails to run within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.0324 AMP s SAMAs AC Power SEPSDG2B.FR3 1-SEPS-DG-2-B fails to run within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.0324 AMP s SAMAs See text HH.OSEP1.FA OPERATOR fails to close SEPS breaker from MCB 1.0323 Section F.5.1 HH.OHPR3.FA OPERATOR fails to close SEPS breaker from MCB, 1.0307 See text given SI signal Section F.5.1 RCPCV456B.RS PORV RC-PCV-456B fails to reseat 1.0300 ECCS SAMAs AC Power EDESWG5.FX 4KV BUS E5 fault 1.0279 AMP s SAMAs RCPCV456A.RS PORV RC-PCV-456A fails to reseat 1.0265 ECCS SAMAs See text HH.ORWMZ1.FA OPERATOR minimizes ECCS flow w/recirc failure 1.0223 Sectixt Section F.5.1 DC Power EDESWG11B.FX DC Power Panel 111 B fails to operate 1.0217 D AMos SAMAs CCTE2271 .FZ PCC Train B Temperature ELEMENT CC-TE-2271 1.0194 Cooling Water transmits false low SAMAs CCTE2171.FZ PCC Train A Temperature ELEMENT CC-TE-2171 1.0192 Cooling Water transmits false low SAMAs HH.OLPR2.FA OPERATOR fails switchover to sump recirc, given 1.0180 See text MLOCA Section F.5.1 HH.OSEP2Q.FA OPERATOR fails to close SEPS breaker from MCB, 1.0178 See text given SI signal Section F.5.1 HH.OLPRI.FA OPERATOR fails switchover to sump recirc, given 1.0178 See text LLOCA Section F.5.1 Seabrook Station Unit 1 License Renewal Application Page F-16 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.1.1.1-2 Top Basic Events by Risk Reduction Worth (Continued)

Associated Basic Event Basic Event Description RRW SAMA HH.OTSI3.FA OPERATOR fails to terminate SI from E-3, given 1.0166 See text SGTR Section F.5.1 HH.ORHPI2.FA OPERATOR restores HPI, given recovery w/Sl 1.0152 See text Section F.5.1 See text HH.OSUFPI.FA OPERATOR fails to start SUFP 1.0151 SetiFt Section F.5.1 Feedwater

&FWV156.FC SUFP to EFIW Header MOV FW-V-156 fails to open 1.0144 Condensate on demand SAMn s SAMAs SUFP to EFW Header MOV FW-V-163 fails to open 14 deate FWV163.FC odead1.0144 Condensate on demandSA s SAMAs See text HH.OFB1C.FA OPERATOR fails to establish feed & bleed cooling 1.0143 See text Section F.5.1 SWV5.FO SW Secondary Isolation MOV SW-V-5 fails to close 1.0142 Cooling Water on demand SAMAs EDESWG11A.FX DC Power Panel 111A fails to operate 1.0142 DC Power SAMAs HH.OFCR5.FL OPERATOR fails to restore AC Power from RSS, 1.0141 See text before RCP Seal LOCA Section F.5.1 AC Power DGP115A.FS DG-1A Engine Driven LUBE OIL PUMP fails to run 1.0136 AMP s SAMAs DGDG1A.FS DG-1A fails to start on demand 1.0132 AC Power SAMAs CCE17B.GL Train B HX E-17B Excessive Leakage During 1.0119 Cooling Water Operation SAMAs DC Power EDEB1B.FP Battery EDE-B-1B failure on demand 1.0119 DAMAe SAMAs DGDG1A.FR2 DG-1A fails to run for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 1.0116 AC Power SAMAs CCE17A.GL Train A HX E-17A Excessive Leakage During 1.0115 Cooling Water Operation SAMAs DGDG1A.FR1 DG-1A fails to run for first hour 1.0113 AC Power SAMAs DGP115B.FS DG-1B Engine Driven Lube Oil Pump fails to start on .1.0111 AC Power demand SAMAs Feedwater

&FWP161.FS Startup Prelube Oil Pump FW-P-161 fails to start on 11 Cdeate FP6.Sdemand 1.0110 Condensate SAMAs HH.ORHPI1.FA OPERATOR restores normal charging, given 1.0107 See text recovery w/o SI Section F.5.1 DGDG1B.FS DG-1B fails to start on demand 1.0107 AC Power SAMAs Seabrook Station Unit 1 License Renewal Application Page F-17 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.1.1.1-2 Top Basic Events by Risk Reduction Worth (Continued)

Associated Basic Event Basic Event Description RRW SAMA See text HH.OSEP1Q.FA OPERATOR fails to close SEPS breaker from MCB 1.0095 SetiFt Section F.5.1 AC Power DGDGIB.FR1 DG-1B fails to run for first hour 1.0091 AMP s SAMAs AC Power SEPSDG2A.FS SEPS DG1 fails to start on demand 1.0089 AMP s SAMAs AC Power SEPSDG2B.FS SEPS DG2 fails to start on demand 1.0089 AMP s SAMVAs HH.OSGLT1.FA OPERATOR maintains long term control of SG 1.0088 See text cooling, given TRANS Section F.5.1 Feedwater

&FWP37B.FS Motor Driven PUMP FW-P-37B fails to start on 1.0088 Condensate demand SAMAs AC Power DGDG1B.FR2 DG-1B fails to run for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 1.0080 AMP s SAMAs DGP38A.FS DG Fuel Oil Transfer Pump DG-P-38A fails to start 1.0079 AC Power on demand SAMAs HH.OCSTM2.FL OPERATOR establishes makeup to CST using CT 1.0076 See text Port. Pump Section F.5.1 SWV4.FO SW Secondary Isolation MOV SW-V-4 fails to close 1.0073 Cooling Water on demand SAMAs HH.OCSTMI.FA OPERATOR establishes makeup to CST for Long 1.0069 See text Term SG Cooling Section F.5.1 CBSV8.FC RHR Train A Suction from CRS MOV CBS-V-8 fails 1.0068 ECCS SAMAs to open on demand ZZ.RCCA.FP Control Rod Assembly fail to insert due to 1.0068 ATWS SAMAs mechanical binding RCPCV456A.FC PORV RC-PCV-456A fails to open on demand 1.0066 ECCS SAMAs Feedwater

&FWP113.FS Startup Feed PUMP FW-P113 fails to start on 1.0066 Condensate demand SAMAs OPERATOR fails to shed DC loads to extend See text battery lifetime Section F.5.1 HH.ORHCD7.FA OPERATOR cools/dep.

RCS for RHR S/D cooling, 1.0065 See text for SGTR w/ OSGRD Section F.5.1 HH.OSGLT7.FL OPERATOR fails long term control of RCS 1.0064 See text inventory

& SG cooling Section F.5.1 DGP38B.FS DG Fuel Oil Transfer Pump DG-P-38B fails to start 1.0064 AC Power on demand SAMAs ZZ.EDEACBA54.FO DG-1A Output Breaker to Bus E5 fails to close on 1.0062 AC Power demand SAMAs HH.RDGL2Q.FL OPERATOR fails to locally reset breakers & start 1.0057 See text R pumps Section F.5.1 Seabrook Station Unit 1 License Renewal Application Page F-18 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.1.1.1-2 Top Basic Events by Risk Reduction Worth (Continued)

Associated Basic Event Basic Event Description RRW SAMA ZZ.EDELOADBBK.FC 4KV Load Supply BREAKER fails to open on AC Power demand 1.0057 SAMAs AC Power ZZ.EDE4KLOADB.FX 4KV Load faults (3 normally operating pumps) 1.0057 AMP s SAMAs RCPCV456B.FC PORV RC-PCV-456B fails to open on demand 1.0054 ECCS SAMAs ZZ.2PORV.NOCRI PROB(UET), given 2 PORVs & 3 SVs available, 1.0051 ATWS SAMAs w/o Control rod insertion EPSE6PRI.FX EPS Train B Relay PR1 (auto DG start) fails to 1.0051 AC Power close SAMAs EPSE6PRlX.FX EPS Train B Relay PRI (auto DG start) fails to 1.0051 AC Power close SAMAs ZZ.EDEACBA74.FO DG-1 B Output Breaker to Bus E6 fails to close on 1.0050 AC Power demand SAMAs Feedwater

&1-FW-PCV-4326 SUFP Recirc fails to open on 1.0050 Condensate FWPCV4326.FC demand SAMAs Seabrook Station Unit 1 License Renewal Application Page F-19 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.3.1.1.2 Level 1 and 2 PRA Model Changes The major Level 1 and 2 changes incorporated into each revision of the Seabrook PRA model are discussed below. Seabrook Station maintains and updates a combined Level 1 and Level 2 model. A Level 3 model was developed to support the SAMA analysis.

The Level 3 model is discussed in Section F.3.4.Seabrook PRA Model History Internal & External Events PRA Model Full Power Results Comments Update CDF LERF 1983 2.3E-04 Original SSPSA model 1986 2.9E-04 First update to model 1989 1.4E-04 Update to IE and CCF modeling 1990 1.1E-04 2.2E-07 Updated to support IPE 1993 8.0E-05 1.6E-08 Updated to support IPEEE, data 1996 4.3E-05 3.7E-08 Updated initiating event models, data 1999 4.6E-05 5.1E-08 Updated top event modeling and incorporated plant changes, data 2000 4.6E-05 5.1E-08 Restructure modeling of train-related top events 2001 4.8E-05 5.1E-08 Updated initiating event models 2002 4.5E-05 6.8E-08 Updated to address peer review comments, data 2004 3.0E-05 1.OE-07 Updated to incorporate plant changes and improve event sequence models/diagrams 2005 1.4E-05 1.1E-07 Updates to improve PRA quality for success criteria, HRA, Seismic, and Level 2 PRA 2006 1.44E-05 1.2E-07 Updated modeling of initiating events, split fractions.

Also updated shutdown PRA model.Seabrook Station 1983 Update (SSPSA -PLG-0300)In December 1983, a full scope Level 3 PSA was completed for Seabrook Station. The purpose of the Seabrook Station Probabilistic Safety Assessment (SSPSA) was to provide a base line risk assessment and an integrated plant and site model for use as a risk management tool. The study was provided to the NRC and the public for information in January 1984.The key findings of the SSPSA were:* The mean severe core damage frequency was 2.3E-04 events per reactor year.Seabrook Station Unit 1 License Renewal Application Page F-20 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives" Both the societal and individual risk provisions of the NRC safety goals were met by wide margins; therefore, the risk to public health and safety was estimated to be extremely small." Different risk factors were found to have different key contributors.

Interfacing systems Loss of Coolant Accident (LOCA) events and, to a lesser extent, seismically-induced transient events with failure of containment isolation were the principal contributors to early risk. The contributors to core melt frequency and latent risk comprised a large group of initiators, including loss of off-site power, transient events, fires, and seismic events. A common event in many dominant sequences and in more than two thirds of the total severe core damage frequency was the reactor coolant pump seal LOCA." The dominant contributors to severe core damage frequency were support system faults, external events, and internal hazards that affected both the core cooling and containment heat removal systems.As a result, a major fraction of the severe core damage frequency, about 73 percent, was associated with sequences in which long- term containment over-pressurization was indicated." Only about 1 percent of the core melt frequency was associated with early containment failure or bypass. This percentage is more than 30 times less than that assumed in the Reactor Safety Study for PWR plants. Its low value is the result of the high strength of the Seabrook Station containment as determined by more detailed analysis.* In contrast with previous PSA containment analyses, the time of containment over-pressurization due to failure to remove decay heat was found to be very long (several days instead of several hours).Seabrook 1986 Update (SSPSS-1986)

This update was the first effort to update the entire PSA to reflect the plant configuration as of mid-1 986. A number of changes had been made from the SSPSA to this study to reflect changes in the plant design from 1983 to 1986 and to accommodate model changes and enhancements in documentation.

Significant changes are listed below: Plant Chanqes:.Technical Specifications

-The allowed outage times were changed for a number of systems, including Service Water System and Primary Component Cooling Water System (the standby pumps are now in the Technical Specifications), ECCS (AOT extended from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days), Emergency Feedwater System (startup feed pump was included along with 2 EFW pumps), containment on line purge valves (allowed open time changed from 1,000 hr per year to unlimited duration but open only within guidelines).

Seabrook Station Unit 1 License Renewal Application Page F-21 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives IST Pump Test Frequency

-For all safety pumps except EFW pumps, the test frequency was extended from monthly to quarterly." Startup Feed Pump -The startup feed pump became self-cooled, rather than cooled by Secondary Component Cooling Water (SCC);tested monthly with other EFW pumps." Turbine Driven EFW Pump -New AOVs were added to the steam admission lines to the turbine driver." Atmospheric Relief Valves -ARVs were modified to be powered by instrument air with gas accumulator backup rather than electro-hydraulic." Boron Injection Tank and Associated Recirculation Pump and Bypass Line -These components were removed." Enclosure Building Air Handling System -New one out of two standby fans were added in the RHR vault return flow path.Reactor Trip Breakers -Shunt trip coil became actuated by the automatic trip signal as well as the UV device.RCP Thermal Barrier Cooling System -The design was finalized, including several manual valves not in the SSPSA model.Model Chanqes: " Event Tree Qualification

-The documentation and traceability of the event tree split fractions back to systems and operator action were enhanced by the use of unique split fraction identifiers.

Also, the method for binning event tree quantification was better documented." Seismic Analysis -The seismic fragilities of important components to the seismic risk were reanalyzed based on actual seismic qualification reports." Systems Analysis -Quantification was done using RISKMAN 3 software.

This enhances the traceability of the systems analysis back to the data as well as improves transcription errors." Systems Analysis -Common cause treatment was expanded in this study to include more than two components failing together in common cause.Other parts of the risk model -'data, human action, containment, and consequence analyses -were unchanged from the original SSPSA model.Seabrook Station1989 Update (SSPSS-1 989)This update revised the 1986 update with plant changes made through July of 1989. This update also included enhanced system modeling, advanced PC based software, and the containment failure/source term enhancements.

Seabrook Station Unit 1 Page F-22 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives The results of this study indicated a reduction in the core damage frequency by a factor of approximately two from the original SSPSA results due to the changes listed below. However, the importance of the RCP seal LOCA remains the same -contributing 70 percent of the core damage frequency total. The estimate of early containment failure was decreased by a factor of 5 to 0.2 percent of the core damage frequency.

This change was due to the incorporation of containment failure and source term enhancements.

This update included the following significant changes from the 1986 update: No significant plant design changes that impacted the risk model were found.Model Changes:* Initiating event frequencies were updated with data through 1987." Common cause and maintenance distributions were updated based on additional industry data." RISKMAN Release 2 software was used for system and plant models.* Electric power recovery model was updated with current power recovery data.* Recovery actions were integrated into the event tree model via a recovery tree at the end of the plant model.Seabrook Station 1990 Update (SSPSS-1990)

This update replaced the 1989 update, and included plant changes through July 1990. The results were summarized in the IPE Report. The significant changes are described below: Plant Changes:* An ATWS Mitigation System was implemented which provides a diverse turbine trip and EFW actuation signal. This hardware update and an update of the ATWS analysis based on WCAP 11993 were included in this update.Model Changes: " Electric power recovery model was updated based on more current PSNH-specific data for recovery of 345 kV grid, update of off-site power data, battery lifetime analysis update, and an update of the RCP seal LOCA analysis.* RISKMAN Release 2 software was used to create a fully-integrated plant containment model from initiating event to release category.* New recovery actions were added (OS, Signal Failure Recovery and RM, RWST makeup).* Present recovery actions were moved in plant model -EFW recovery and SWS recovery were added to the event trees.Seabrook Station Unit 1 License Renewal Application Page F-23 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Containment event tree was updated to explicitly model Induced Steam Generator Tube Rupture and Direct Containment Heating.Seabrook Station 1993 Update (SSPSS-1993)

-IPEEE This update replaced the 1990 update, with plant changes through the end of the second cycle, November 1992. A number of changes were made to the model. A summary of changes is given below.No significant plant design changes that impacted the risk model were made.Model Changes:* Seabrook Station-specific data were included for the main safety pumps and the diesel generators." Control Room Fire -operator actions were modeled in more detail, as part of the IPEEE analysis.* New fire hazard Initiating Events were added to the plant model." Event Tree Modeling -the event tree logic was streamlined, corrected in some cases, and placed almost exclusively in the logic rules." StartUp Feed Pump was modeled conservatively to always require manual start.* Modeling of High Pressure Injection (HPI) was expanded to include separate top events for all four HPI pumps.Seabrook Station 1996 Update (SSPSS-1996)

This update replaced the 1993 update, with plant changes through the end of the fourth cycle, January 1996. A number of changes were made in the model. A summary of changes is given below.Plant Changes:* The ATWS Mitigation System modification was completed during this update period. A component level fault tree model of AMS was added." Revised the ATWS model to account for 24-month fuel cycle.Model Changes:* Seabrook Station-specific data were included for the main safety pumps and the diesel generators." Upgraded the RISKMAN software to Release 8.0.° Expanded the system fault trees to more accurately model systems (additional components and more realistic alignments for normally operating systems).° Additional and expanded initiating event models based on loss of trains of support systems.Seabrook Station Unit 1 License Renewal Application Page F-24 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives" Expanded several initiating event models from a single value to a fault tree." Combined transient initiators into two." More accurate modeling of ventilation.

Seabrook Station 1999 Update (SSPSS-1999)

This update replaced the 1996 update, with plant changes through the end of the sixth cycle, March 1999.Plant Changes: " Alternate cooling modification (ALT) to provide charging pump cooling in the event of loss of PCCW, was completed during this update period. A component level fault tree model of ALT was added.* Revised ATWS model to account for 18-month fuel cycle.Model Changes: " Added an explicit top event (SEAL) in the General Transient tree to model the sizes of RCP seal LOCAs and the impact on sequence timing." Added new top event in the General Transient tree to model recovery of PCCW, EDGs, and off-site power. These series of top events replace the off-line electric power recovery model.* Component failure rates associated with reactor trip breaker model were updated to a more current generic data source.* Initiating event frequencies were updated with plant-specific data and updated to a more current generic data source." Plant specific data were gathered and used to update generic distributions for major pumps and SWS motor-operated valves." The mission time for EFW was changed from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> to be consistent with UFSAR analysis." Air handling dampers in the charging pump cubicles were moved from the air- handling model to the charging-pump A/B model because they impact a single pump.° Changes were made to operator action quantification and to event tree rules to more carefully model operator dependencies.

• The common cause failure (CCF) modeling for SWS and PCCW system initiators was revised to change the mission time for CCF terms to 1 year and by generating new CCF parameters.

Seabrook Station Unit 1 Page F-25 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Seabrook Station 2000 Update (SSPSS-2000)

This update replaced the 1999 update. This minor update to SSPSS-1999 was based on conversion of the RISKMAN model from Version 9.2 (DOS-based) to Version 3.0 (Windows-based).

The change in software allowed lower truncation limits in solving fault trees, which resulted in some slight increases in the results for SWS and PCCW systems. Also, the system-model structure in RISKMAN was modified to support migrating the model to the Safety Monitor for on-line maintenance evaluations.

No significant plant design changes that impacted the risk model were made.Model Changes: The structure for two train top events was revised so that only the system top event contains the fault tree, common cause modeling, and alignment definitions.

Train-level top events were redefined as conditional split fractions, based on system level split fractions.

This did not change the system results, but supported the migration of the model to the Safety Monitor.Seabrook Station 2001 Update (SSPSS-2001)

This update replaced the 2000 update. This minor update to the SSPSS-2000 was made to incorporate changes to support export to the Safety Monitor. No significant plant design changes that impacted the risk model were made.Model Changes: Minor changes were made to the system initiator models.Seabrook Station 2002 Update (SSPSS-2002)

This updatereplaced the 2001 update, with plant changes through the end of the eighth cycle, June 2002. No significant plant design changes that impacted the risk model were made.Model Changes: Modeling and documentation changes were made, many to close out Peer Review comments.

These included operator action analysis (e.g., adding a dependency matrix for actions), systems analysis (e.g., expanding the SWS alignment model to include one train on ocean, one train on cooling tower), and event tree analysis (e.g., added steam line break initiators and event tree logic).Seabrook Station 2004 Update (SSPSS-2004)

This update replaced the 2002 update, with plant changes through the end of the ninth cycle, December 2004.Seabrook Station Unit 1 License Renewal Application Page F-26 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Plant Changes: " Addition of Supplemental Electric Power System (third emergency diesel generator).

• Startup Feedwater Pump normal alignment changed from Bus 4 to Bus E5.Model Changes: Modeling and documentation changes were made to improve the quality and usefulness of the PRA. The following were the most significant changes: " Event sequence diagrams for all Mode 1 -3 sequences were completely redone, with references added to related Emergency Operating Procedure steps and modeled operator action top events." The entire human action analysis was revised, using the new event sequence diagrams and the EPRI HRA tool." The SGTR event sequence model was entirely revised based on the latest Westinghouse analysis." The loss of off-site power model was revised by adding a new initiator to account for grid-related events and updating the off-site power recovery analysis to the latest EPRI report.Seabrook Station 2005 Update (SSPSS-2005)

This update replaced the 2004 update, with plant changes through the end of cycle 10, April 2005.Plant Changes: " SEPS main control board switch and related modifications.

.Power uprate related changes to operator timing from MAAP runs* DC Battery lifetime was updated to design analysis" Diesel Generator failure rate and unavailability data Model Changes: Modeling and documentation changes were made to improve the quality and usefulness of the PRA. The following were the most significant changes: " Success criteria update based on a series of MAAP runs" HRA update with revised sequence timing and other changes" Revision to operator dependency analysis* Revision to Plant Operating States for shutdown model" Major update to seismic PRA" Major update to Level 2 analysis Seabrook Station Unit 1 Page F-27 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Seabrook Station 2006 Update This update replaced the 2005 update. The 2006 update incorporated changes in the shutdown PRA model based on insights from outage risk management during the Cycle 11 refueling outage. It also made a few minor clean-up changes to the full-power model.No significant plant design changes that impacted the risk model were made.Model Changes: Modeling and documentation changes were made to improve the quality and usefulness of the PRA. The following were the most significant changes:* Major update to shutdown PRA" Revision to modeling of PCC and SWS initiators

• Renamed several initiators for clarity in reviewing models* Revision to SEPS split fraction definitions to account for dependencies with EDGs.F.3.1.2 EXTERNAL EVENTS F.3.1.2.1 Internal Fires and Seismic Events Internal fires and seismic events are explicitly modeled and included in the Seabrook Station PRA model discussed in the previous section.F.3.1.2.2 Other External Events NUREG 1407 recommends a screening type approach, as shown in Figure F.3.1.2.3-1 (taken from Figure 5-1 of NUREG-1407).

The general methodology used at Seabrook Station follows the approach recommended by NUREG-1407 and consists of the following steps: " Establishing a list of plant-specific other external events" Progressive Screening" Walkdown" Documentation Seabrook Station Unit 1 Page F-28 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives FIGURE F.3.1.2.3-1 NUREG-1407 SCREENING APPROACH RECOMMENDED IPEEE APPROACH FOR WINDS, FLOODS, AND OTHERS (1) Review Plant-Specific Hazard Data and Licensing Bases (FSAR)(2) Identify Significant Changes, if Any, Since OL Issuance No (3) Does Plant/Facilities Design Meet 1975 SRP Criteria? (Quick Screening I` and Walkdown)Or Or (4) Is the Hazard Frequency Acceptably Low?1-2" NoI Or (5) Bounding Analysis (Response/Consequence)

No Yes No4 Or I 01 (6)Probabilistic Risk Assessment I I (7)Documentation (including Identified Reportable Items and Proposed Improvements)

K-Note: Steps 4 through 6 are optional.Seabrook Station Unit 1 License Renewal Application Page F-29 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Based on the results of the Seabrook Station IPEEE, it was concluded that the plant structures at the site are well designed to withstand the hazards associated with high wind and that no potential vulnerability was identified.

With respect to external flooding, the Seabrook Station plant design meets the 1975 SRP criteria and no plant vulnerabilities were identified.

However, the PRA model includes a conservative quantitative assessment of external flooding.

The current model considers a storm-related external flood initiating event EXFLSW occurring at a frequency of 1.6E-06/yr.

The external flood initiator is assumed to cause failure of the ocean SW pumps. However, the cooling tower SW pumps, which are located in the cooling tower structure and at an elevation higher than the ocean SW pumphouse, remain available following the initiating event. The core damage frequency from this event is-2E-08/yr.

This quantitative assessment supports the conclusion that there are no design vulnerabilities from an external flooding perspective.

The NRC staff concluded, in the Seabrook Station IPEEE SER, that, according to GDC 4, GDC 19, and SRP Section 2.2.3, the Seabrook Station is adequately protected and with acceptable risks with respect to transportation and nearby facility hazards.Based on a review of the lightning strikes at the site, it was concluded that the impacts of lightning strikes were less severe to Seabrook Station than a complete loss of off-site power. Also, according to Section 2.6 of NUREG-1407, the probability of a severe accident caused by lightning is relatively low.Therefore, lightning is not a significant contributor to core damage frequency for Seabrook Station.The contribution to the Seabrook Station total CDF from the other external events is less than 1.OE-06 per year, and as concluded in the Seabrook Station IPEEE, there are no vulnerabilities to other external events at Seabrook.F.3.1.2.3 External Event Severe Accident Risk An external event severe accident risk assessment is integrated with the internal events risk; the PRA includes both internal and external event risks.This assessment approach provides the means to evaluate SAMAs for both internal and external events simultaneously without the need to separately estimate the impact of the potential improvements on external events.F.3.2 LEVEL 2 PLANT-SPECIFIC PRA MODEL The Level 2 PRA model determines release frequency, severity, and timing based on the Level 1 PRA, containment performance, and accident progression analyses.Seabrook Station Unit I Page F-30 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.3.

2.1 DESCRIPTION

OF LEVEL 2 PRA MODEL The accident sequence analysis defines the manner in which the expected plant response to each identified initiating event or initiating event category is represented and quantified.

The analysis considers successes and failures of safety functions and related systems, and human actions to determine whether or not core damage occurs. The result of the Level 1 accident sequence analysis is a set of event trees that represent and quantify the accident sequences.

The Level 2 analysis extends the Level 1 analysis to the release category potential for the Level 1 core damage end states. A containment event tree represents and quantifies the release category potential when evaluated with the Level 1 event trees.The containment model was significantly revised in the 2005 update to reflect current state-of-the-art understanding of containment phenomena and operator actions directed by Severe Accident Management Guidelines (SAMGs). The basis for this updated model is documented in WCAP-16600, Seabrook Station Probabilistic Risk Assessment:

Level 2 PRA Update, Volume 1 and 2, Revision 0, June 2006 (Reference 2). The following is a summary of the Level 2 model from that reference.

The containment model (Level 2) analysis provides the interface between the Plant (Level 1) analysis and the site / consequence (Level 3) analysis by assigning core damage sequences to various release categories.

The model defines the various phenomena which potentially could cause containment structural failure and then quantifies the magnitude of the challenge and the resulting probability of containment failure. If failure is predicted, the analysis also determines the mode of failure and the magnitude and timing of the radiological release from the failed containment.

The inputs to the Level 2 analysis are core damage sequences.

These sequences are considered in groups of accident sequences that exhibit similar thermal-hydraulic behavior.

It is expected that sequences with similar thermal-hydraulic responses would impose similar stresses on the containment.

Grouping this way allows the analyst to focus on a limited number of representative sequences instead of the large number of possible Level 1 sequences.

The output of the Level 2 analysis is the frequency of Release Categories which define the magnitude and timing of radiological releases from the failed containment.

The mapping of sequences between the Level 1 model and release categories is governed by the CET. The CET top events question the occurrence of certain physical processes and, depending on these occurrences, determine the containment failure or bypass probability from that mechanism.

The CET also includes containment-related hardware (spray, isolation) and operator actions, both early and late in the event.Seabrook Station Unit 1 Page F-31 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives The CET evaluates containment performance.

The inputs to the CET are core damage sequences from the Level 1 model. The CET contains the logic regarding the response of the containment to pressure challenges from the various sequences.

The CET top event logic primarily represents the occurrence of physical processes, associated containment mitigation systems and operator actions. The containment analysis covers all conceivable failure modes of the containment, including pre-existing leaks, containment bypass sequences, external hazards impacting the structure, and internal loads that have the potential to fail the containment early (shortly after the core melt) or late (many hours after the melt). The Level 2 analysis considers the combined response of the reactor coolant system, containment structure, and engineered safeguards systems. Representative Level 1 sequences are used to evaluate the thermal-hydraulic response of the core and containment in order to determine whether certain phenomena would be expected to occur. The MAAP 4.0.5 severe accident simulation code was used to investigate the severe accident progression for the updated Seabrook Level 2.The CET is linked directly with the Level 1 event trees to generate the frequencies of each release category bin. These release category bins are defined based on containment failure modes, and distinguish between the size of the release (large vs small) and the timing of the release (early vs late). For reporting purposes, Table F.3.2.1-1 defines the release categories by release type (size, timing) and by containment failure mode. Basic Event Importance for Level 2 basic events that contribute to a large early release frequency (LERF) is provided for information in Table F.3.2.1-2.

Seabrook Station Unit 1 Page F-32 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.2.1-1 Release Category Bin Definition Release Category Frequency Bin (per yr) Bin Description INTACT -Containment intact with less than Tech. Spec. -allowed leakage INTACT 9.13E-06 (nominal leakage).

Includes containment intact with great than Tec. Spec.leakage but less leakage than failure of small containment penetration.

LL3 2.95E-06 LL3 -LARGE, LATE -Vented containment.

SE3 -SMALL, EARLY -Small containment penetration leak that may progress SE3 1.04E-06 to large late failure. Includes contribution of large containment penetration failure to isolate with spray injection/scrubbed release.SEl 4.67E1-07 SE1 -SMALL, EARLY -Early SGTR-initiated core melt with feed to the faulted steam generator.

SE2 -SMALL, EARLY -Interfacing LOCA through RHR pump seals (submerged SE2 3.33E-07 reas)release).LL5 3.32E-07 LL5 -LARGE, LATE -Basemat melt-through.

LE1 -LARGE, EARLY -SGTR-initiated (or pressure-induced tube ruptures) core LE1 1.10E-07 melt with NO feed to faulted steam generator (failure of EFW/SUFP or operator does not restore flow). Includes contribution from thermally-induced SGTR.LL4 7.47E-08 LL4 -LARGE, LATE -Long-term containment overpressure failure. Includes contribution of small, late containment failure.LE2 4.01 E-09 LE2 -LARGE, EARLY -Interfacing LOCA with RHR pipe rupture (V-sequence)

LE3 9.71E-10 LE3 -LARGE, EARLY -Failure of large containment penetration to isolate (COP valves) or large pre-existing leakage.Total 1.44E-05 Core Damage Frequency (CDF)Seabrook Station Unit 1 License Renewal Application Page F-33 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.2.1-2 Basic Event Importances for Total Plant LERF by Risk Reduction Worth BE Risk Basic Event Description Reduction Associated SAMA CBSV11 .FC CBS Pump P-9A Discharge MOV CBS-V-11 1.0215 Containment SAMAs fails to open on demand CBSV17.FC CBS Pump P-9B Discharge MOV CBS-V-17 1.0210 Containment SAMAs fails to open on demand DGDG1A.FR2 DG-1A fails to run for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 1.0086 AC Power SAMAs DGDG1A.FR3 DG-1A fails to run for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.0103 AC Power SAMAs DGDG1A.FS DG-1A fails to start on demand 1.0052 AC Power SAMAs DGDG1B.FR2 DG-1B fails to run for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 1.0087 AC Power SAMAs DGDG1B.FR3 DG-1B fails to run for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 1.0083 AC Power SAMAs DGDG1B.FS DG-1B fails to start on demand 1.0051 AC Power SAMAs Turbine Driven Pump FW-P-37A fails to start on Feedwater

&demand Condensate SAMAs Motor Driven Pump FW-P-37B fails to start on Feedwater

&demand Condensate SAMAs FWV7O.FC MDP Discharge Check Valve FW-V-70 fails to 1.0075 Feedwater

&open on demand Condensate SAMAs PORV Train A Spray Valve fails to open on Depressurization RCPCV456A.

FC dead1.0055SMs demand SAMAs PORV Spray Valve Train B fails to open on Depressurization RCPCV456B.FC demand 1.0054 SAMAs COTK25.RT Condensate Storage Tank CO-TK-25 1.0189 SAMA 162 ruptures/excessive leakage dur DGP115A.FS DG-1A Engine Driven Lube Oil Pump fails to 1.0054 AC Power SAMAs start on demand DGP115B. FS DG-1 B Engine Driven Lube Oil Pump fails to 1.0052 AC Power SAMAs start on demand Feedwater

&FWP1 13.FR Startup Feed Pump FW-P1 13 fails to run 1.0190 Condeate A Condensate SAMAs Startup Feed Pump FW-P113 fails to start on Feedwater

&FWP113.FS demand 1.0510 Condensate SAMAs Startup Prelube Oil Pump FW-P-161 fails to Feedwater

&FWP161.FS start on demand 1.0886 Condensate SAMAs Feedwater

&FWP37A.FR Turbine Driven Pump FW-P-37A fails to run 1.4231 Condeate A Condensate SAMAs Seabrook Station Unit 1 License Renewal Application Page F-34 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.2.1-2 Basic Event Importances for Total Plant LERF by Risk Reduction Worth (Continued)

BE Risk Associated Basic Event Description Reduction SAMA Feedwater

&FWP37A.FS1 Turbine Driven Pump Turbine FW-P-37A fails to 1.0796 Condensate start on demand SAMAs Feedwater

&FWP37B.FR Motor Driven Pump FW-P-37B fails to run 1.0426 Condensate SAMAs Feedwater

&1-FW-PCV-4326 SUFP Recirc fails to open on 1.0387 Condensate FWPCV4326.FC demand SAMAs Feedwater

&FWV127.CL Manual Valve FW-V-127 transfers closed 1.0142 Condensate SAMAs Feedwater

&SUFP to EFW Header MOV FW-V-156 fails to 18 Cdeate FWV156.FC opno ead1.1186 Condensate open on demand SAMAs Feedwater

&SUFP to EFW Header MOV FW-V-163 fails to 18 Cdeate FWV163.FC opno ead1.1186 Condensate open on demand SAMAs Feedwater

&MDP Recirc MOV FW-V-347 transfers open 1.0317 Condensate FWV347.OP (flow diversion)

SAMAs Feedwater

&FWV71.CL MoP Discharge VALVE FW-V-71 transfers 1.0142 Condensate closed SAMAs HH.ODDSG1.FA OPERATOR Fails to Diagnose SG Rupture 1.0291 See text Event Section F.5.1 HH.OIMSV1.FA OPERATOR fails to isolate MS valves from 1.0113 See text ruptured SG Section F.5.1 HH.ORHCD7.FA OPERATOR cools/dep.

RCS for RHR S/D 1.0310 See text cooling; for SGTR w/ OSGRD Section F.5.1 HH.ORWCDI.FA OPERATOR depressurizes RCS to minimize 1.0099 See text leakage w/ recirc failure Section F.5.1 HH.ORWIN1.FA OPERATOR initiates makeup to RWST; given 1.0075 See text LOCA w/ recirc failure Section F.5.1 HH.ORWLT1.FA OPERATOR maintains stable plant conditions 1.0057 See text w/ long term makeup Section F.5.1 HH.ORWMZ1.FA OPERATOR minimizes ECCS flow w/ recirc 1.0621 See text failure Section F.5.1 HH.OSEP2.FA OPERATOR fails to close SEPS breaker from 1.0102 See text MCB; given SI signal Section F.5.1 HH.OSGRC1.FA OPERATOR fails to cool down RCS (SGTR) 1.0060 See text Section F.5.1 HH.OSGRD1.FA OPERATOR fails to Depressurize RCS to Stop 1.0156 See text Break Flow from Rupture Section F.5.1 HH.OSlG3.FA OPERATOR fails to manually actuate HPI 1.0276 See text pumps; given SLOCA w/ ES Section F.5.1 Seabrook Station Unit 1 License Renewal Application Page F-35 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.2.1-2 Basic Event Importances for Total Plant LERF by Risk Reduction Worth (Continued)

BE Risk Associated Basic Event Description Reduction SAMA HH.OSIG7.FA OPERATOR fails to manually initiate SI signal; 1.0053 See text given SLB w/ SSP Section F.5.1 HH.OSIG8.FA OPERATOR fails to manually close MSIV & 1.0266 See text start HPI pumps Section F.5.1 HH.OSUFP2.FA OPERATOR fails to start on demand SUFP; 1.0517 See text given SI initiator Section F.5.1 HH.OTEFW3.FA OPERATOR Fails to Terminate EFW Feedflow 1.0071 See text to isolate ruptured SG Section F.5.1 HH.OTS13.FA OPERATOR fails to terminate SI from E-3; 1.0861 See text given SGTR Section F.5.1 HH.XOEFW1.FA Operator establishes feed flow to faulted SG 1.1873 See text Section F.5.1 MSV395.FC Steam Admission Valve MS-V-395 fails to open 1.0056 See text on demand Section F.5.1 ZZ.RCCA.FP Control Rod Assembly fail to insert due to 1.0184 ATWS SAMAs mechanical binding ZZ.SY2.FX Loss of Offsite Power subsequent to LOCA 1.1777 AC Power initiator SAMAs F.3 F.3.2.2 LEVEL 2 PRA MODEL CHANGES SINCE IPE SUBMITTAL The major Level 2 changes incorporated into each revision of the Seabrook Station PRA model are provided in Section F.3.1.1.2.

3.3 MODEL

REVIEW

SUMMARY

Regulatory Guide (RG) 1.174 (Reference 24), Section 2.2.3, states that the quality of a PRA analysis used to support an application is measured in terms of its appropriateness with respect to scope, level of detail, and technical acceptability, and that these are to be commensurate with the application for which it is intended.The PRA technical acceptability of the model used in the development of this SAMA application has been demonstrated by a peer review process. The initial certification peer review was conducted in 1999 under the direction of the [former] Westinghouse Owner's Group. An additional focused peer review was conducted in 2005, which assessed the Seabrook PRA against the ASME Standard.The overall conclusions of the peer review were:* All of the technical elements were sufficient to support applications requiring the capabilities defined for grade 2. The Seabrook Station PRA provides an appropriate and robust tool to support such activities Seabrook Station Unit 1 License Renewal Application Page F-36 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives as Maintenance Rule implementation, supported as necessary by deterministic insights and plant expert panel input.All of the elements were determined sufficient to support applications requiring the capabilities defined for grade 3, e.g., risk-informed applications supported by deterministic insights, but in some cases this is contingent upon implementation of recommended enhancements.

After the peer review, the preliminary Category A and B facts and observations that potentially impacted the model were dispositioned and incorporated into the updated PRA model. All Category A and B facts and observations (F&O) were implemented.

The PRA model has since undergone additional revision, but the incorporated resolution of Category A and B F&O has been maintained.

The Seabrook Station Category A and B F&O and resolutions are summarized below.F&Os from the 1999 Certification Peer Review F&O 1 Summary: The frequencies of initiators L2CCA and L2CCB are under estimated due to the common cause model. The common cause term should include T=1 year (rather than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />).Resolution:

Changes were made to the CCF models in PCC and SWS initiators to use 1 year as the mission time.F&O 2 Summary: The existing analyses for ISLOCA should be reviewed for consistency with a methodology for identification and quantification of ISLOCA pathways such as that provided in NUREG/CR-5744, and updated if appropriate.

Resolution:

Reviewed NUREG/CR-5744 for ISLOCA methodology and revised the ISLOCA assessment.

F&O 3 Summary: Within the SBO sequence, operation of turbine-driven EFW pump beyond the 8-hour battery life has been modeled. This implies considerable reliance on the turbine-driven EFW pump operating in manual control without benefit of SG level instrumentation.

This is not consistent with industry practice unless operators practice and are comfortable with the associated procedures.

The ability of the operators to successfully cool the core using this pump without underfeeding the SG, resulting in undercooling of the core and eventual core damage, or overfeeding the SG, resulting in water carry-over to the EFW pump turbine, and its subsequent failure, should be addressed.

Seabrook Station Unit 1 Page F-37 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Resolution:

Battery lifetime was recalculated, going back to the electrical calculations.

The 4-hour value is well established; aggressive load shedding and cross tie can provide battery power out beyond 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.The time to core uncovering at 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> was calculated.

The total time (battery + TCU) was used as the maximum available time.F&O 4 Summary: The emergency diesel generator recovery failure probability seems optimistic for the medium RCP seal LOCA event. The data for recovery of an EDG is based on data taken from LERs based on EDG failures.

This data is used to develop a recovery curve. However, this recovery is applied in conditions very different than the conditions in the LER -common cause failure of both EDGs resulting in SBO conditions.

The EDG recovery is based on generic data composed of EDG single failures during normal operation.

This data needs to be reviewed to ensure applicability to CCF events, particularly events during more adverse SBO conditions (i.e., where stress, crew availability, and so forth, are more limiting).

In addition, plant-specific evidence should be used to support this recovery probability.

Resolution:

Evaluated Seabrook Station EDG failure data. Of the four failures, two could easily be recovered within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The other two failures were considered long-term failures.

Based on SB data, a non-recovery probability of 0.5 was used for DG recovery.F&O 5 Summary: The small LOCA event sequence includes credit for refilling the RWST to allow continued high pressure injection if the RHR pumps fail and AC power and secondary side cooling are available.

The credit appears to be considerable, with an operator failure probability of approximately of 0.01. If the action is successful, the sequence is considered successful.

There is little detail regarding the time available to perform this action. Few PSAs take credit for this. The scenario implies an indefinite (or at least undefined) period of operation in this mode, and might require additional refilling or other mitigative actions later on. These actions may be expected and realistic (although it appeared to the reviewers that this contradicts the operator action description provided in the HRA section);

however, such credit may not be appropriate without extending the entire PRA model to include severe accident management issues, procedures, and guidance, and/or adjusting the mission times for functions such as secondary side cooling to match the required mission time (if it can be defined) for injection.

Evaluate the impact of credit for RWST refill in the PRA model. Consider either revising the model to not credit this action (or to properly account for the potential ramifications noted above), or including a sensitivity case Seabrook Station Unit 1 Page F-38 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives with each PRA update to identify the effects of this credit. If retained, provide additional documentation as to the feasibility of this action, based on thermal hydraulic analysis and procedural compliance.

Resolution:

The event tree top event for reactor water makeup-long term (RMLT) was deleted from the event tree because of the concern for operator dependencies.

For event tree top event reactor makeup (RM), a detailed dependency analysis was performed, including RM, to assure that multiple operator actions were not included inappropriately.

F&O 6 Summary: Following a large break LOCA, the operator action and hardware required to isolate the RWST-to-RHR-pump suction valves is not modeled. (Opening of the sump-to-RWST suction on low-low RWST level is automatic but closure of the RWST valves is not.) Justification was not provided for this assumption.

Resolution:

Reviewed design basis information to understand when the operator action is required.

Evaluated a new operator action for sump recirculation switchover for a large LOCA using the EPRI HRA Tool.Added new rule to the LOCA event tree to require this action for successful large LOCA sequences.

F&O 7 Summary: The EFW mission time is defined as 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />, but no justification is provided to "stop" the scenario at a successful end state prior to the traditional 24-hour mission time. No calculation was found to justify availability of EFW supply for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and there is no modeling (or evaluation of the adequacy) of alternative decay heat removal beyond 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />. Ensure that the accident sequences adequately address 24-hour mission time, preferably either using thermal hydraulic calculations or explicit PRA modeling.Resolution:

The EFW mission time basis was reviewed and additional documentation was added to the PRA to support the use of 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> for the mission time.F&O 8 Summary: Continued operation of the RCPs is credited for the small LOCA scenario.

The EOP directs the operators to trip RCPs if RCS subcooling is less than 40 0 F. Is there a calculation for the PRA that determines the subcooling?

If not, then it is possible that the RCPs would need to be tripped during this scenario, with the need to be re-started if credited later in scenario; however, RCP hardware failures are not modeled. Re-evaluate the success criteria for and modeling of continued RCP operation in this scenario, and add RCP hardware failures to the analysis if appropriate.

Seabrook Station Unit 1 Page F-39 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Resolution:

The only impact of RCPs in the small LOCA model is on top event OLR -RHR shutdown cooling. Failure of OLR leads to sump recirculation.

RCPs may need to be tripped depending on the size of the small LOCA (based on the 40°F subcooling criterion).

However, if the operator successfully depressurizes and cools down the primary system (OLR), subcooling should be restored.

The EOPs instruct the operator to restart the RCPs given subcooling is restored.

The RCPs are modeled through top event OG, offsite power available, since they are powered from Bus 1 & 2 (non-emergency powered).

Only one of four RCPs is needed for adequate flow. Thus, as long as power is available, the hardware failure is insignificant in comparison to the operator failure rate in OLR.F&O 9 Summary: The model includes credit for "automatic bleed and feed" cooling following a loss of secondary side heat removal, as long as both charging pumps are available.

The basis for its usage in the Seabrook Station PRA is a calculation which has relatively simplistic T&H analysis, which does not address potential factors such as eventually filling the RCS via the charging pumps, leading to water relief from the PORVs (thereby significantly reducing heat removal capability via latent heat); increasing containment back-pressure (thereby affecting the flow rate through the PORVs); or the potential for resultant high containment humidity and temperatures to affect the automatic control features that are being relied upon in this scenario.

If credit for automatic bleed and feed is to be taken in the models, a more thorough analysis should be done, addressing potential environmental, control system, thermal-hydraulic, and other factors that could affect the decay heat removal capability being credited.Resolution:

Credit for auto feed and bleed was removed from the PRA model.F&O 10 Summary: Room cooling -the assumption of a greater-than-5-hour heat-up as acceptable should have a clearer basis. This appears to be potentially important in at least one set of cases (switchgear, battery room, electrical tunnels), where the exclusion of room cooling is on the basis of an hour heat-up time.Consider tying any screening value to a more physical basis, such as timing of operator (NSO) rounds. Consider investigating the relative importance of room cooling for cases in which the estimated timing is close to the screening value.Resolution:

Evaluated the background for 6-hour room heatup.Regarding the NSO rounds/actions, multiple MCB alarms would have to Seabrook Station Unit 1 Page F-40 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives fail for this event to go undetected.

Once detected the MCB Dpoint alarm procedure directs action.F&O 11 Summary: The values for BETA2, GAMMA2, and DELTA2 are not derived as recommended in NUREG/CR-5485 as stated in the text. That document (p.76) recommends that "the values of 2, 3, and 4 in Table 5-11 be reduced by a factor of 2 when applied to frequency of failure during operation." The effect of reducing theses values (and adding the difference to *1) is to reduce only the Beta factor -the gamma factors and delta factors are unchanged since the factor of one-half factors out.Contrary to this guidance, the MGL factors corresponding to the alpha factors in Table 5-11 were calculated, then the Beta factors were reduced by a factor of 2. Note these values were used in the PCC system and initiating event analyses, resulting in some factors being under-estimated by a factor of 4. The discussion in 6.3.3 regarding variable BETA1 is in error -5 CCFs and 100 independent failures provides a beta factor of 5/105 if staggered testing is used, not the .05 indicated.

A lognormal distribution is not appropriate for the GAMMA1 and DELTA1 -they should be modeled using beta distributions.

Resolution:

The values for GAMMA2 and DELTA2 were recalculated using the correct equations.

Also beta distributions were developed for these generic distributions.

With regard to the comment that BETA1 should be 5/105 rather than 0.05, these are essentially the same number.F&O 12 Summary: Examine dependencies of HEPs embedded within recovery models with other human actions included in the plant model. Examine most recent component failure data to ensure recoverable failure fraction remains valid. Develop appropriate procedures for identifying and evaluating dependencies.

Resolution:

Operator dependencies were examined, resulting in changes made to the logic rules and HEP quantification.

F&O 13 Summary: The updated Seabrook Station Probabilistic Safety Assessment (SSPSA) uses several Human Reliability Analysis (HRA)methods (HCR, THERP and ASEP) for evaluating HEPs. In some cases the original SSPSA HEPs are referenced.

No guidance is provided which clearly identifies the rationale for selecting one particular methodology over another when evaluating particular operator actions.Develop an approach and guidance for appropriately and consistently selecting the HRA methodology to be applied.Seabrook Station Unit 1 License Renewal Application Page F-41 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Resolution:

Developed a methodology for when to apply various HRA methods. Evaluated all operator actions for proper application of the methodology.

F&O 14 Summary: The plant model includes operator actions which are not evaluated in the current HRA analysis.

These include potentially important actions for SG isolation and RCS depressurization (including SL, 04, 05 and OD, as well as failure to transfer SW from cooling towers to ocean and vice versa).The HEPs for these actions are derived from the 1983 SSPSA. While that analysis provides extensive discussions of the actions in question, the HEPs themselves appear to be based on judgment only, rather than the application of any formal HRA technique.

Thus, specific event timings and procedural guidance are not explicitly reflected in the HEPs. There are also other examples of time-available windows used without referenced supporting thermal-hydraulic analysis (e.g., manual transfer to cooling tower pumps, provide makeup to RWST following extended bleed and feed).The HRA analyses of the events in question should be updated to account for current HRA techniques and should be supported by appropriate T/H analysis.

Appropriate T/H references should be added to the existing (new) HRA analysis.

It may be possible to prioritize the actions to be updated by comparing the existing HEPs with those for similar actions in other plant PRAs and evaluating the relative potential for impact on the Seabrook PRA results.Resolution:

Reviewed all human actions modeled to look for HEPs that are inconsistent and/or not well documented.

Operator actions were considered together to evaluate the self-.consistency of the HEPs. As a result of this review, several action HEPs were revised.F&O 15 Summary: While operator and simulator experience has clearly been included in the evaluation of some of the actions modeled using the HCR model, there has been no formal and documented process for obtaining operations review and input into the base case HEP and update process.Have operations/

training review base case HEP analysis and updates on a periodic basis.Resolution:

Reviewed all human actions modeled to look for HEPs that are inconsistent and/or not well documented.

Operator actions were considered together to evaluate the self-consistency of the HEPs. As a result of this review, several action HEPs were revised. Operations review of HEPs completed.

Seabrook Station Unit 1 License Renewal Application Page F-42 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F&O 16 Summary: There is no formal approach for identifying and evaluating dependencies of operator actions within accident sequences.

There are many sequences in which multiple redundant operator actions appear with no justification of rationale for de-coupling.

Of particular concern are SGTR sequences (failure of early and late depressurization) and transient sequences with failure to initiate ESFAS, recover TD EFW pump, align start up feed pump, and initiate feed and bleed. It is recognized that some dependencies have been addressed via the split fraction logic (e.g., failure to initiate reactor trip given preceding failure to initiate SSPS). While no specific cases where such operator action dependencies might significantly impact CDF were identified during the review, no conclusive position is possible without the implementation and description of a formal process to address this issue. Develop and implement an appropriate process for identifying and evaluating dependencies.

Resolution:

Evaluated operator action dependencies to determine whether multiple actions in the same sequence are justifiable.

Changes were made to the event tree logic rules and HEP quantification to account for dependent events.F&O 17 Summary: Consider adding an HEP-sensitivity to the set of analyses normally performed to evaluate quantification results. In such a sensitivity, all HEPs should be set to 0.1 (including those embedded within equipment recovery events) and the accident sequence quantification repeated.Appropriate insights should be deciphered and acted upon.Resolution:

A sensitivity case was run where all operator action split fractions with value less than 0.1 were set to 0.1. This also included recovery actions with values less than 0.1. This sensitivity was limited to post-initiator actions. The conclusion was the only multiple operator action sequences that were significant contributors with all actions set to 0.1 were actions where the dependencies had already been addressed.

F&O 18 Summary: Recovery actions were included in the sequences but not treated within the HRA analysis.

Examples are the recovery of the turbine-driven AFW pump and the recovery of an EDG. The reviewer concern is that it is important to understand whether or not there are human action dependencies within the modeled recoveries, and, if so, to ensure that dependencies are tracked and correctly treated. Ensure all modeled recovery actions are consistent with the HRA so that potential dependencies are addressed.

Resolution:

Operator dependencies were examined, resulting in changes made to logic rules and the HEP quantification.

Seabrook Station Unit 1 License Renewal Application Page F-43 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F&O 19 Summary: A discussion of the limitations of using the saved sequences as a PRA model of the plant was not located. Although a very low cutoff is used to generate saved sequences, it is important that all analysts understand where limitations may exist so that they can be evaluated for specific applications Resolution:

This issue of truncation has been addressed in the PRA documentation along with general guidance for setting the truncation level.Practically, this issue must be evaluated for each analysis.

It is not possible to give general guidance that addresses every application.

F&O 20 Summary: Following a reactor trip, loss of all DC, and success of off-site power, RCP seal integrity questions are asked without determining the probability of failure of the operating charging and PCCW pumps. Include hardware faults of the running pumps as part of the necessary logic for RCP seal LOCA. This appears to lead to overestimating reactor trip contribution to CDF.Resolution:

In the 2002 model, the sequence "reactor trip -and- loss of all DC power" leads to core melt because EFW and SUFP require at least one train of DC power. Also, the PORVs are failed given loss of DC power. Thus, this sequence goes to core melt because both AFW and feed and bleed cooling are unavailable (not the seal LOCA sequence).

While there is opportunity for recovery of an AFW pump (by locally starting either pump), the probability of loss of both DC buses is extremely small (3E-7). Also, this may cause other plant conditions that would confuse the operator.

Thus, no operator recovery credit is taken.F&O 21 Summary: There are split fractions defined in the master frequency file that include operator recovery actions. Instances of sequences that have multiple operator actions were identified with products in the 1 E-05 range.Without documentation regarding operator dependencies, this may lead to underestimating operator contribution.

Resolution:

Operator dependencies were examined.

This resulted in changes made to logic rules and HEP quantification.

F&O 22 Summary: At present no parametric uncertainty analysis exists based on the current plant model. While such studies were performed for earlier versions of the SSPSA, the results have significantly changed (internals are far less dominant) and the uncertainty distribution may no longer be valid.Seabrook Station Unit 1 License Renewal Application Page F-44 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives At present there is no formal analysis which addresses plant specific uncertainty or sensitivity issues. For example, cases where thermal hydraulic analyses predict only small margins for success in terms of the number of trains required, or the time available for operator actions, are prime candidates.

Other examples might be cases where unique success criteria or modeling have been applied such as for feed and bleed and for RWST make up following LOCA. Perform a set of sensitivity runs and a qualitative or quantitative uncertainty analysis for the model. Risk achievement analyses may be used to focus the search for potentially significant cases.Resolution:

Performed an uncertainty analysis to address this F&O.Ensured that all split fractions have an uncertainty distribution associated with them and quantified all event tree top events with Monte Carlo. Also quantified all system initiating events with Monte Carlo. Quantified uncertainty for dominant sequences for CDF and LERF.F&O 23 Summary: The PRA assessment of Level 2 phenomena is based on pre-1990 knowledge and methodologies.

This leads to several important phenomena not being explicitly addressed in the PSA (e.g., transition to detonation for hydrogen burns) and conservative treatment of other phenomena (e.g., alpha mode steam explosion containment failure, DCH containment failure, etc.). All of these can impact the LERF calculated in the PRA. Since the LERF is dominated by interfacing system LOCA and SG tube rupture, it is not expected to make a significant numerical difference, but the study needs to be updated for completeness and accuracy.

Upgrading the analysis from MAAP 3.Ob to 4.0 would be helpful in this regard.Resolution:

Addressed in the MAAP Phase 2 project and PRA 2005 Update.F&O 24 Summary: The Level 2 analyses are based primarily on MAAP 3.Ob analyses performed in the 1980's. There have been significant changes to code models, particularly MAAP 3b, Version 15 to MAAP 4.0, dealing with, among other items, in-vessel recovery and induced SG creep rupture damage.(a) A change in the modeling of in-vessel recovery could impact the PSA results, because the newer code/models mechanistically predict additional hydrogen generation during recovery (which was seen at TMI-2). This could lead to a hydrogen challenge to the containment integrity and, in turn, the LERF.(b) A change in modeling the potential for creep failure of the SG tubes (induced tube rupture) could impact the PSA results because the Seabrook Station Unit 1 License Renewal Application Page F-45 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives newer code models mechanistically predict creep failure of SG tubes. Also, significant information is now available on creep failure with SG tube degradation.

This could lead to a change in the predicted occurrence of creep failure bypass and, in turn, the LERF.(c) The latest expert opinion on direct containment heating (DCH) has changed since the early 1990's and Seabrook Station should NOT be susceptible to DCH. The PSA is still based on the "old" DCH viewpoint reflected in NUREG/CR-4551.

The high level issue here is PSA maintenance

-whether there is a process inplace for assessing changes to PSA models, updating applicable PSA models to reflect current knowledge, and the frequency this is done.Resolution:

Addressed in the MAAP Phase 2 project and PRA 2005 Update.F&O 25 Summary: The PRA includes some post-core damage operator actions (e.g., RCS depressurization and in-vessel recovery for a station blackout)that are generally not modeled in the Level 2 PSA for other plants.While this is a plus, the Level 2 analyses do not include all severe accident management guidance (SAMG) activities.

While SAMG is generally viewed as something new, it is really just a formalized structure of considering what to do if the core melts and the EOPs are no longer valid. Previously, PSA considered that no actions would be taken under the premise that this was conservative.

The real problem was the lack of procedures for the HRA model to consider.

Now with SAMG we can quantify the change from a passive operator status and could find that LERF increases while small late release frequency decreases.

The reason for the increase in LERF is the chance of wrong operator actions.Assess SAMG impact and update Level 2 analysis at next scheduled update.Resolution:

Addressed in the MAAP Phase 2 project and PRA 2005 Update.F&O 26 Summary: Many of the CET top event probabilities cannot be traced to the quoted references of the PRA.Resolution:

Reviewed and revised CET split fraction values.F&O 27 Summary: In many cases, release categorization (release magnitudes and timings) were based on IDCOR analyses for Zion core-melt Seabrook Station Unit 1 Page F-46 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives sequences and the results were adjusted for Seabrook Station. In other cases, the release magnitudes and timings were based on WASH-1400.

For example: (a) For release category S3-A-R, MAAP results based on IDCOR analysis for Zion were adjusted and used for Seabrook Station.See also, for release category S6-R where a Zion case for SBO with a single puff release were adjusted and applied to Seabrook Station SBO sequence with a three puff release.(b) For release category S& A, the release fractions and timing were taken directly from WASH-1400.

Similarly, release category SlW was based on WASH-1400 results.(c) For release category S6B, IDCOR Zion's MAAP results for a containment bypass sequence "V-Sequence" were applied to Seabrook Station's containment failure to isolate sequence after adjusting the release magnitudes.

Note that the results of WASH-1400 study and the results of IDCOR analyses (which used earlier versions of the MAAP code, possibly 2.0 or 1.0) do not represent the state of the art or current state of knowledge in severe accident phenomenology.

Update the thermal hydraulic simulation of the dominant accident sequences using the most recent version of MAAP 4.0 Resolution:

Addressed in the MAAP Phase 2 project and Level 2 PRA upgrade (Westinghouse).

Seabrook Station MAAP deck updated to 4.0.5.A significant MAAP library has been populated, Level 2 success criteria defined and the containment event tree revised. Event timing and impacts have been revised.F&O 28 Summary: For release category S4V, the source term release magnitudes of a basemat melt-through SBO sequence was modeled as a long-term over-pressurization failure of the containment at the time of basemat melt-through.

Use MAAP code to run the SBO sequence that leads to basemat melt-though.

MAAP code will calculate the basemat ablation rate and the depth of basemat ablation as a function of time.When the fission products are filtered through the soil, only the noble gases could potentially be released to the environment.

Resolution:

Addressed in the MAAP Phase 2 project and Level 2 PRA upgrade (Westinghouse).

Seabrook Station MAAP deck updated to 4.0.5.A significant MAAP library has been populated, Level 2 success criteria defined and the containment event tree revised. Event timing and impacts have been revised.Seabrook Station Unit 1 Page F-47 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F&O 29 Summary: Based on the literature, volatile and nonvolatile releases above 10% mass fraction are considered large in severity.

Volatile and nonvolatile releases below 1 % mass fraction are considered small in severity.

The moderate releases correspond to a mass fraction ranging from 1% to 10% for both volatiles and non-volatiles.

As can be seen in the Seabrook Source Terms, a more conservative approach was used to calculate the LERF than the above described methodology.

Update the source term categorization as described above.Resolution:

Addressed in the MAAP Phase 2 project and Level 2 PRA upgrade (Westinghouse).

Seabrook Station MAAP deck updated to 4.0.5.A significant MAAP library has been populated, Level 2 success criteria defined and the containment event tree revised. Event timing and impacts have been revised.F&O 30 Summary: During a review of plant design changes incorporated into the 1999 PRA models, it appeared that Design Change Request (DCR)89-061 had not been incorporated into the service water fault tree. This DCR deleted the cooling tower fan auto-start feature. Therefore, a human error basic event was to be added to the service water fault tree. The service water fault tree did not appear to have been modified.

Also, the PRA documentation still includes the cooling tower fans being actuated by a TA signal. It is believed that this is an isolated occurrence.

However, the host utility should check for any others. Incorporate this DCR into the system fault tree / notebook.Resolution:

A review of the PRA documentation (Service Water Notebook) indicated that this DCR had indeed been incorporated in the PRA model. In fact, the system notebook describes the modeling of the cooling tower and indicates that the operator must manually initiate CT operation and provides a justification for why this action is not modeled.The Service Water notebook was updated to ensure completeness.

Also, a review of DCRs for the 1999 update was performed to ensure that all DCRs that impact the PRA model were addressed.

F&Os from the 2005 Focused Peer Review F&O 31 Summary: The ASME Category II capability for this SR requires the use of realistic, applicable T/H analyses for accident sequence parameters.

Category Ill requires use of realistic, plant specific T/H analyses.

Although most of the SSPSS parameters have supporting calculations that are plant specific, it appears that some would benefit from more realistic analyses.In at least one case (i.e., CST depletion) more realistic analyses may impact sequence development (and are dependent on whether the EFW Seabrook Station Unit 1 Page F-48 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives pump or SUFP is running).

Expectation for future applications is more extensive use of realistic codes (e.g., MAAP), as applicable.

Resolution:

The SSPSS-2005 update effort used MAAP to provide substantial additional plant-specific, realistic support. In some cases such as the CST example noted above, hand calculations were considered to be appropriate and were reviewed to assure adequate realism. The actions below were taken to address realistic/plant-specific success criteria: (1) Listed all current Level 1 success criteria, including impact of power uprate, RCPs, IA, etc.(2) Identified current basis for success criteria.(3) Ran series of MAAP runs where needed to provide basis.F&O 32 Summary: While simulator exercises were observed, there is no evidence of specific talk-throughs with Operations/Training.

Interaction with Operations and/or Training is important regarding the assumptions used in the HRA, especially response times and performance shaping factors (PSFs), to confirm that the interpretation and implementation of the procedures are consistent with plant training and expected responses.

Resolution:

Walkthroughs

/ talk-throughs with Operations and/or Training were used to confirm modeling of operator actions and accident sequences.

F&O 33 Summary: In general, the time available to complete actions is based on either generic T/H analyses for similar Westinghouse 4-loop plants or plant-specific analyses.

Several issues were identified that may point to the need for establishing a more thorough and realistic basis. For example: The write-up for the operator action ODEP1 for SBO events states that 8.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> are available to perform this action, which is based on 9.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to core damage from WCAP-16141, less one hour to restore equipment.

However, WCAP-1 6141 states that without depressurization, core damage can occur as early as 2.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />.Therefore, the time available to perform this action should not exceed the time to core damage without credit for the action. It should be noted that WCAP-16141 does not specifically mention when depressurization must begin, but it seems to be assumed that depressurization will typically begin within 30 -45 minutes. Since this action has a low F-V and RAW importance, SR HR-G4 is judged to be satisfied.

Seabrook Station Unit 1 Page F-49 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives" WCAP-16141, which is used as a basis, assumes that the turbine-driven AFW pump supplies 1145 gpm, which seems to exceed the capacity of the Seabrook Station TD AFWP." The basis of the time available for operator action ODEP3 does not appear to be realistic.

SSPSS-2004 credits post-LOCA cooldown and depressurization for MLOCA with high head injection (HHI) success.Operator Action timing (3.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) is based on a small LOCA, not MLOCA. The success criteria indicates that only 42.8 minutes are available before reaching low-low level for MLOCA. While it is true that MLOCAs at the high end of the spectrum should not require this action and MLOCAs on the low end of the spectrum behave more like a small LOCA, the majority of MLOCAs will be in between. Using the average timing between the high end (42.8 minutes) and low end (3.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />)would not leave enough time to successfully establish low pressure recirculation prior to reaching the RWST low-low level switchover setpoint." The time assumed to be available for feed and bleed using the Safety Injection (SI) pumps, which is based on the time until SG dryout, may not be realistic.

It would seem that establishing feed and bleed with the charging pumps would have different timing than establishing feed and bleed with the SI pumps due to the lower shutoff head of the SI pumps. In particular, while waiting until SG dryout could allow successful feed and bleed cooling using the charging pumps, it isn't clear that waiting until SG dryout would allow successful feed and bleed cooling using the SI pumps." The time available for operator action HH.ORSGC2.FL is 2.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, which is based on time to core damage. However, restoring secondary cooling at the time of core damage will not prevent core damage. In order to prevent core damage, secondary cooling must be completed earlier (e.g., core uncovery)With respect to the items identified:

(1) Re-evaluate the time available to perform RCS cooldown and depressurization following an SBO. Also evaluate the applicability of WCAP-14161 assumptions regarding flow from the turbine-driven AFW pump.(2) Re-evaluate the time available used to quantify operator actions for depressurization and feed and bleed by performing sequence-specific MAAP (or other) thermal-hydraulic runs. In the case of operator action to perform depressurization for MLOCA sequences, T/H runs may need to be performed for an "average" MLOCA break size.Seabrook Station Unit 1 Page F-50 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives (3) Use MAAP or some other calculations to determine the latest time at which secondary cooling can be restored and still prevent core damage.More generally, complete the ongoing effort to establish appropriate timeframes using realistic codes (e.g. MAAP).Resolution:

Revised the HRA Calculator quantification using time windows from Seabrook Station-specific MAAP runs.F&O 34 Summary: Dependency between multiple human actions was considered, and the process for quantifying dependencies is described in SSPSS-2002.

This appears to be a good approach.

However, there is no guidance as to how to identify sequences with multiple operator actions for inclusion in the dependency analysis.

Also, while the matrix showing dependency between two operator actions is good, it does not include new actions since the 2002 update. The review discovered at least two examples where dependencies appear to be inadequately addressed:

(1) The dependency between operator actions ORSGC and OFB does not appear to be modeled, other than time consumed associated with responding to feed and bleed criteria.

There is also some dependency in diagnosing the loss of secondary heat sink for these two actions.(2) The procedural guidance in Functional Restoration Procedure FR-H.1 for aligning fire water is contained in the RNO column of Step 14, which is predicated on not being able to open the PORVs.However, if the PORVs are opened too late, the procedure will not direct the operator to establish fire water to the SGs. This dependency is not modeled.Although significant progress has been made in this area since the 1999 peer review, it appears that there remains a need to develop an overall process for identifying multiple operator actions that need to be addressed in the dependency analysis.Resolution:

The following actions were taken during the PRA update: 1. Identified all dynamic actions embedded in hardware top events.2. Created new Operator Action top events, separate from hardware where appropriate.

3. For PCCW, redefined System split fractions to be conditional on Operator Action OPCC and added house events.4. Added new top events to event trees 5. Modified logic rules to account for operator action dependency to system.Seabrook Station Unit 1 Page F-51 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.3.4 LEVEL 3 PRA MODEL The Seabrook Station Level 3 PRA model, "Calculation of Severe Accident Risks for Seabrook Station License Renewal," Revision 0, May 2009 (Reference

4) determines off-site dose and economic impacts of severe accidents based on the Level 1 PRA results, the Level 2 PRA results, atmospheric transport, mitigating actions, dose accumulation, and economic analyses.The MELCOR Accident Consequence Code System (MACCS2) Version 1.13.1 was used to perform the calculations of the off-site consequences of a severe accident.

This code is documented in NUREG/CR-6613, "Code Manual for MACCS2: Volumes 1 and 2" (Reference 23).Plant-specific release data included the time-dependent nuclide distribution of releases and release frequencies.

The behavior of the population during a release (evacuation parameters) was based on plant- and site-specific set points. These data were used in combination with site-specific meteorology to simulate the probability distribution of impact risks (both exposures and economic effects) to the surrounding 50-mile radius population as a result of the release accident sequences at Seabrook Station.The following sections describe input data for the MACCS2 analysis tool.F.3.4.1 POPULATION DISTRIBUTION The population in the 50-mile radius surrounding the Seabrook Station site was estimated based on the 2000 United States census data, as accessed by SECPOP2000, NUREG/CR-6525, Revision 1 (Reference 25). The population distribution was estimated in 10 concentric bands at 0 to 1 mile, 1 to 2 miles, 2 to 3 miles, 3 to 4 miles, 4 to 5 miles, 5 to 10 miles, 10 to 20 miles, 20 to 30 miles, 30 to 40 miles, and 40 to 50 miles distant from the site, and 16 directional sectors with each sector consisting of 22.5 degrees. The population was projected to the year 2050 by calculating an annual growth rate derived from state and national population projections for each county that fell entirely or partially in the 50-mile radius. The peak transient population within 10 miles of the site was added to the resident population.

The population distribution used in this analysis is provided in Table F.3.4.1-1.

Seabrook Station Unit 1 Page F-52 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.1-1 Population Projections Used in SAMVA Analysis 2000 2050 From Radius To Radius Direction Code Population Population 0 N 1 24 37 0 NNE 2 0 0 0 NE 3 29 44 o0 ENE 4 0 0 o0 E 5 0 0 o0 ESE 6 0 0 0 SE 7 163 249 o 1 SSE 8 68 104 0 1i 9 139 213 0 1 SSW 10 65 99 o 1 SW 11 10 15 0 1 WSW 12 234 358 0 1 W 13 0 0 0 1 WNW 14 144 220 0 1 NW 15 0 0 0 1 NNW 16 12 18 1 2 N 17 48 73 1 2 NNE 18 36 55 1 2 NE 19 143 219 1 2 ENE .20 12889 19720 1 2 E 21 4241 6489 1 2 ESE 22 5178 7922 1 2 SE 23 180 275 1 2 SSE 24 160 245 1 2 5 25 852 1304 1 2 SSW 26 1177 1789 1 2 SW 27 1372 2085 1 2 WSW 28 463 708 1 2 W 29 546 835 1 2 WNW 30 410 627 1 2 NW 31 385 589 1 2 NNW 32 232 355 2 3 N 33 462 707 2 3 NNE 34 1876 2870 2 3 NE 35 2385 3649 2 3 ENE 36 1530 2341 Seabrook Station Unit 1 License Renewal Application Page F-53 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.1-1 Population Projections Used in SAMVA Analysis (Continued) 2000 2050 From Radius To Radius Direction Code Population Population 2 3 E 37 83 127 2 3 ESE 38 0 0 2 3 SE 39 1084 1480 2 3 SSE 40 563 746 2 3 5 41 890 1174 2 3 SSW 42 1149 1417 2 3 SW 43 469 586 2 3 WSW 44 843 1199 2 3 W 45 5180 7925 2 3 WNW 46 122 187 2 3 NW 47 283 433 2 3 NNW 48 247 378 3 4 N 49 1477 2260 3 4 NNE 50 3075 4705 3 4 NE 51 3744 5728 3 4 ENE 52 788 0 3 4 E 53 0 0 3 4 ESE 54 0 0 3 4 SE 55 475 584 3 4 SSE 56 17035 20953 3 4 5 57 677 833 3 4 SSW 58 772 950 3 4 SW 59 412 507 3 4 WSW 60 512 677 3 4 W 61 398 609 3 4 WNW 62 165 252 3 4 NW 63 265 405 3 4 NNW 64 584 894 4 5 N 65 1290 1974 4 5 NNE 66 946 1447 4 5 NE 67 1967 3010 4 5 ENE 68 0 0 4 5 E 69 0 0 4 5 ESE 70 0 0 4 5 SE 71 907 0 Seabrook Station Unit 1 License Renewal Application Page F-54 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.1-1 Population Projections Used in SAMVA Analysis (Continued) 2000 2050 From Radius To Radius Direction Code Population Population 4 5 SSE 72 570 701 4 5 5 73 1727 2124 4 5 SSW 74 481 592 4 5 SW 75 3965 4877 4 5 WSW 76 2720 3627 4 5 W 77 383 586 4 5 WNW 78 460 704 4 5 NW 79 195 298 4 5 NNW 80 640 979 5 10 N 81 4740 7252 5 10 NNE 82 12234 18718 5 10 NE 83 1824 2791 5 10 ENE 84 0 0 5 10 E 85 0 0 5 10 ESE 86 0 0 5 10 SE 87 0 0 5 10 SSE 88 8149 10023 5 10 5 89 8579 10552 5 10 SSW 90 13747 16909 5 10 SW 91 9131 11231 5 10 WSW 92 10967 15048 5 10 W 93 3420 5233 5 10 WNW 94 2917 4463 5 10 NW 95 12776 19547 5 10 NNW 96 6103 9338 10 20 N 97 18631 30655 10 20 NNE 98 35979 64058 10 20 NE 99 1257 0 10 20 ENE 100 0 0 10 20 E 101 0 0 10 20 ESE 102 0 0 10 20 SE 103 2645 3253 10 20 SSE 104 6834 8406 10 20 5 105 24275 29858 10 20 SSW 106 25776 31704 Seabrook Station Unit 1 License Renewal Application Page F-55 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.1-1 Population Projections Used in SAMA Analysis (Continued) 2000 2050 From Radius To Radius Direction Code Population Population 10 20 SW 107 83246 102583 10 20 WSW 108 57428 83797 10 20 W 109 23379 35770 10 20 WNW 110 17121 26195 10 20 NW ill 9286 14219 10 20 NNW 112 26180 40239 10 20 N 113 48853 87821 20 30 NNE 114 13515 25408 20 30 NE 115 404 0 20 30 ENE 116 0 0 20 30 E .170 0 20 30 ESE 118 0 0 20 30 SE 119 3723 4579 20 30 SSE 120 28230 34723 20 30 5 121 194637 239404 20 30 SSW 122 131825 148885 20 30 SW 123 243606 274789 20 30 WSW 124 67459 101033 20 30 W 125 66566 101297 20 30 WNW 126 21229 32729 20 30 NW 127 8059 12347 20 30 NNW 128 26311 40534 30 40 N 129 29456 55377 30 40 NNE 130 24528 46113 30 40 NE 131 1 0 30 40 ENE 132 0 0 30 40 E 133 0 0 30 40 ESE 134 0 0 30 40 SE 135 0 0 30 40 SSE 136 0 0 30 40 5 137 55193 72028 30 40 SSW 138 854916 880481 30 40 SW 139 164382 166026 30 40 WSW 140 146505 195879 30 40 W 141 104996 154390: Seabrook Station Unit 1 License Renewal Application Page F-56 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.1-1 Population Projections Used in SAMA Analysis (Continued) 2000 2050 From Radius To Radius Direction Code Population Population 30 40 WNW 142 95248 156828 30 40 NW 143 18505 30158 30 40 NNW 144 16317 26107 40 50 N 145 11669 21936 40 50 NNE 146 54518 102494 40 50 NE 147 158 0 40 50 ENE 148 0 0 40 50 E 149 0 0 40 50 ESE 150 0 0 40 50 SE 151 0 0 40 50 SSE 152 0 0 40 50 S 153 189524 213707 40 50 SSW 154 818677 869864 40 50 SW 155 121411 133277 40 50 WSW 156 52404 65728 40 50 W 157 27385 40263 40 50 WNW 158 37532 61054 40 50 NW 159 24473 40248 40 50 NNW 160 10559 17711 Total 4232394 5185206 Seabrook Station Unit 1 License Renewal Application Page F-57 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.3.4.2 ECONOMIC DATA The agricultural and economic data for the Seabrook offsite evaluations were derived from the SECPOP2000 program, NUREG/CR-6525, Revision 1 (Reference 25). This code utilized county economic factors derived from the 2000 census. For the Seabrook model, the county data files were updated with circa 2000 data for the 13 counties within 50 miles of the plant. The following specific economic parameters are used in the Seabrook Station SAMA.Variable Description Seabrook Value DPRATE(1) Property depreciation rate (per yr) 0.20 DSRATE" 1' Investment rate of return (per yr) 0.12 EVACST Daily cost for a person who has been evacuated

$52 EVACST_____

($/person-day)

POPCST Population relocation cost ($/person)

$9632 RELCST Daily cost for a person who is relocated

($/person-day)

$52 ODERM Cost of farm decontamination for various levels of $1,084 & $2,408 decontamination

($/hectare)

(2)CDNFRM Cost of non-farm decontamination per resident person for $5,779 & $15,412 various levels of decontamination

($/person)

DLBCST Average cost of decontamination labor ($/man-year)

$67,427 VALWF Value of farm wealth ($/hectare)

(2) $22,880 VALWNF Value of non-farm wealth average in US ($/person)

$193,003 DPRATE and DSRATE are based on MACCS2 Users Manual (Reference 23)(2) 1 hectare = 10,000 m 2 = 2.47 acres F.3.4.3 NUCLIDE RELEASE The core inventory corresponds to the end-off-cycle values for projected future 3,659 MWt Seabrook Station operations, as determined by the ORIGEN2.1 code.Table F.3.4.3-1 provides the estimated inventory of the core at shutdown used in this analysis.

Cobalt inventory (Co-58 and Co-60) are based on the PWR inventory in MACCS2 sample problem A multiplied by 3659/3412 (the ratio of the Seabrook power level to the power level in sample problem A).Table F.3.4.3-2, Accident Category Frequencies and Release Fractions, provides a description of the release characteristics evaluated in the SAMA analysis.

Table F.3.4.3-2 provides the release frequencies, nuclide release fractions of the core inventory, and the time distribution of the release (for noble gases and Cs) analyzed to determine the sum of the exposure (50-mile Seabrook Station Unit 1 License Renewal Application Page F-58 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives dose) and economic (50-mile economic costs) risks from the Seabrook Level 2 accident release category bins. Release fractions and associated times for accident categories LE-2, LE-3, SE-2, SE-3, and LL-5 were taken from Seabrook original analyses of releases for these accident categories.

All other category release fractions and times are from Seabrook MAAP simulations.

Seabrook Station Unit 1 License Renewal Application Page F-59 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.3-1 Core Inventory Nuclide Core Inventory (Curies)Co-58 9.34E+05 Co-60 7.14E+05 Kr-83m 1.19E+07 Kr-85 1.26E+06 Kr-85m 2.49E+07 Kr-87 4.77E+07 Kr-88 6.70E+07 Rb-86 3.03E+05 Sr-89 9.25E+07 Sr-90 1.OOE+07 Sr-91 1.13E+08 Sr-92 1.23E+08 Y-90 1.05E+07 Y-91 1.20E+08 Y-92 1.24E+08 Y-93 1.43E+08 Zr-95 1.64E+08 Zr-97 1.61 E+08 Nb-95 1.66E+08 Mo-99 1.89E+08 Tc-99m 1.66E+08 Ru-103 1.88E+08 Ru-105 1.51E+08 Ru-106 1.OOE+08 Rh-105 1.34E+08 Sb-127 1.39E+07 Sb-129 3.78E+07 Te-127 1.38E+07 Te-127m 1.87E+06 Te-129 3.72E+07 Te-129m 5.52E+06 Te-131m 1.60E+07 Te-132 1.46E+08 1-131 1.05E+08 1-132 1.49E+08 1-133 1.99E+08 1-134 2.15E+08 Seabrook Station Unit 1 License Renewal Application Page F-60 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.3-1 Core Inventory (Continued)

Nuclide Core Inventory (Curies)1-135 1.87E+08 Xe-131m 1.18E+06 Xe-133 1.99E+08 Xe-133m 6.45E+06 Xe-135 5.01E+07 Xe-135m 4.22E+07 Xe-138 1.61E+08 Cs-134 3.26E+07 Cs-136 8.35E+06 Cs-137 1.37E+07 Ba-139 1.75E+08 Ba-140 1.68E+08 La-140 1.75E+08 La-141 1.59E+08 La-142 1.54E+08 Ce-141 1.62E+08 Ce-143 1.48E+08 Ce-144 1.34E+08 Pr-143 1.46E+08 Nd-147 6.39E+07 Np-239 2.92E+09 Pu-238 5.15E+05 Pu-239 3.99E+04 Pu-240 7.07E+04 Pu-241 1.87E+07 Am-241 1.85E+04 Cm-242 8.77E+06 Cm-244 2.60E+06 Br-82 8.71 E+05 Br-83 1.18E+07 Br-84 2.04E+07 Rb-88 6.82E+07 Rb-89 8.73E+07 Y-94 1.45E+08 Y-95 1.56E+08 Nb-95m 1.18E+06 Tc-101 1.76E+08 Seabrook Station Unit 1 License Renewal Application Page F-61 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.3.4.3-1 Core Inventory (Continued)

Nuclide Core Inventory (Curies)Pd-109 6.30E+07 Sb-124 3.73E+05 Sb-125 2.41E+06 Sb-126 2.11E+05 Te-125m 5.26E+05 Te-133 1.18E+08 Te-133m 7.13E+07 Te-134 1.61 E+08 1-130 7.59E+06 Cs-134m 8.44E+06 Cs-138 1.79E+08 Ba-141 1.59E+08 La-143 1.47E+08 Pm-147 1.38E+07 Pm-148 2.97E+07 Pm-148m 3.43E+06 Pm-149 6.83E+07 Pm-151 2.41E+07 Sm-153 7.82E+07 Eu-154 2.OOE+06 Eu-155 1.39E+06 Eu-156 4.77E+07 Np-238 7.06E+07 Pu-243 1.27E+08 Am-242 1.29E+07 Seabrook Station Unit 1 License Renewal Application Page F-62 I-CD C'CD X CD CD 0 9V 0.(D 0)0-0 Table F.3.4.3-2 Accident Category Frequencies and Release Fractions Accident Category LE-1 LE-2 LE-3 SE-1 SE-2 SE-3 LL-3 LL-4 LL-5 Intact Frequency 1.10E-07 4.01E-09 9.71 E-10 4.67E-07 3.33E-07 1.04E-06 2.95E-06 7.47E-08 3.32E-07 9.13E-06 Release Fraction by Release Category Xe/Kr 6.99E-01 9.OOE-01 1.OOE+00 4.04E-02 9.OOE-01 1.OOE+00 6.89E-01 1.OOE+00 1.00E+00 3.46E-03 I 2.99E-02 7.00E-01 1.00E-02 4.70E-03 7.00E-04 1.30E-02 2.82E-03 3.51E-01 1.00E-03 1.02E-07 Cs 2.67E-02 5.00E-01 1.OOE-02 4.58E-03 5.00E-04 1.30E-02 1.37E-03 2.21E-01 1.00E-03 6.83E-08 Te 2.54E-02 3.00E-01 2.80E-04 1.44E-03 3.OOE-04 3.50E-03 4.41E-04 2.04E-01 2.00E-03 8.32E-08 Sr 6.90E-05 6.OOE-02 6.20E-04 7.68E-06 6.OOE-05 1.50E-03 4.61E-06 3.63E-05 1.OOE-05 1.47E-10 Ru 1.03E-02 2.OOE-02 6.OOE-05 3.29E-04 2.OOE-05 9.OOE-04 3.06E-06 4.07E-05 1.OOE-05 1.06E-08 La 1.64E-05 4.00E-03 6.OOE-05 6.29E-07 4.00E-06 1.40E-04 1.79E-07 3.37E-05 1.OOE-05 3.21E-11 Ce 2.92E-05 4.00E-03 6.00E-05 2.49E-06 4.00E-06 1.40E-04 3.56E-06 4.42E-05 1.00E-05 7.02E-11 Ba 1.18E-03 6.OOE-02 6.20E-04 9.23E-05 6.00E-05 1.50E-03 4.67E-06 5.73E-05 1.00E-05 3.74E-09 Sb 7.35E-02 3.00E-01 2.80E-04 2.42E-03 3.00E-04 3.50E-03 1.92E-03 4.03E-02 2.OOE-03 5.23E-08 Release time (hr from scram) of bulk of noble gas/Cs release 2.7-4.7 / 2.5-3/ 4-20 / 2.7-5.6/ 8.5-15.5/

22-66 / 34-58/ 36-60/ 89-90 / 3.4-33/2.7-4.7 2.5-3 4-20 2.7-5.6 8.5-15.5 22-66 34-58 36-60 89-90 2.6-8.9 0 CD Cf, CD CD >-0> CD o0~CL x CD )~CD CD 0 Co CD 0)

Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.3.4.4 EMERGENCY RESPONSE A reactor scram signal begins each evaluated accident sequence.

A General Emergency is declared when plant conditions degrade to the point where they are judged to be a credible risk to the public. Therefore, the timing of the General Emergency declaration is sequence-specific and declarations generally range from 1 to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for the release sequences evaluated.

The MACCS2 User's Guide input parameters of 95 percent of the population within 10 miles of the plant [Emergency Planning Zone (EPZ)] evacuating and 5 percent not evacuating were employed.

These values have been used in similar studies (e.g., Hatch, Calvert Cliffs, [SNOC 2000] and [BGE 1998]) and are conservative relative to the NUREG-1 150 study, which assumed evacuation of 99.5 percent of the population within the EPZ.The evacuees are assumed to begin evacuation 120 minutes (MACCS2 Sample Problem A) after a General Emergency has been declared, at a radial speed of 0.58 m/sec. This speed is derived from the projected time to evacuate the entire Seabrook EPZ under adverse weather conditions during the year 2000, the year of the evacuation study, Seabrook Station Radiological Emergency Plan, SSREP, (Reference 26). The evacuation speed was projected to year 2050 conditions by conservatively assuming that all of the roads in 2000 transported traffic at their maximum throughput and that no new roads would be constructed (although the roads would be maintained at 2000 conditions).

The 2050 evacuation speed was then the 2000 speed multiplied by the ratio of 2000 to projected 2050 EPZ (10-mile)populations.

That estimated 2050 evacuation speed, 0.41 m/sec, was used in the risk analysis.

Both the evacuation speed and the time from emergency declaration to the start of evacuation was considered further in the sensitivity analyses presented in Section F.8.F.3.4.5 METEOROLOGICAL DATA Each year of meteorological data consists of 8,760 weather data sets of hourly recordings of wind direction, wind speed, atmospheric stability, and accumulated precipitation.

The data were from the Seabrook Station site weather facility for the years 2004 through 2008. MACCS2 does not permit missing data, so bad or missing data were filled in by (in order of preference):

using corresponding data from meteorological tower instruments at another level (taking the relationship between the levels as determined from immediately preceding hours), interpolation (if the data gap was less than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />), or using data from the same hour and a nearby day of a previous year.The 2005 data set was found to result in the maximum economic cost and dose risks (see subsequent discussion of sensitivity analysis).

Therefore, the 2005 sequential-hourly meteorology was used to create the one-year Seabrook Station Unit 1 Page F-64 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives sequential-hourly data set used in the baseline MACCS2 runs. Ten-meter wind speed (adjusted from the data facility 43-foot measurements) and 10-meter wind direction (taken equivalent to the 43-foot measurements) were combined with precipitation and atmospheric stability (specified according to the vertical temperature gradient as measured between the 209- and 43-foot levels) to create the hourly data. Hourly stability was classified according to the scheme used by the NRC.F.4 COST OF SEVERE ACCIDENT RISK / MAXIMUM BENEFIT Cost/benefit evaluations of SAMAs are based on the cost of implementing a SAMA compared to the averted onsite and offsite costs resulting from the implementation of that SAMA. The methodology was based on the NRC's guidance for the performance of cost-benefit analyses (Reference 16). This guidance involves determining the net value for each SAMA according to the following formula: Net Value = (APE + AOC + AOE + AOSC) -COE Where: APE = present value of averted public exposure ($), AOC = present value of averted offsite property damage costs ($), AOE = present value of averted occupational exposure ($), AOSC = present value of averted onsite costs ($)COE = cost of enhancement

($).If the net value of a SAMA is negative, the cost of implementing the SAMA is larger than the benefit associated with the SAMA and is not considered beneficial.

The derivation of each of these costs is described in below.The following specific values were used for various terms in the analyses: Present Worth The present worth was determined by: PW- e r Where: r is the discount rate = 7% (assumed throughout these analyses)t is the duration of the license renewal = 20 years PW is the present worth of a string of annual payments = 10.76 Dollars per REM The conversion factor used for assigning a monetary value to on-site and off-site exposures was $2,000/person-rem averted. This is consistent with the NRC's regulatory analysis guidelines presented in and used throughout NUREG/BR-0184 (Reference 16).On-site Person REM per Accident The occupational exposure associated with severe accidents was assumed to be 23,300 person-rem/accident.

This value includes a short-term component of 3,300 person-rem/accident and a long-term component of Seabrook Station Unit 1 Page F-65 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives 20,000 person-rem/accident.

These estimates are consistent with the "best estimate" values presented in Section 5.7.3 of Reference

16. In the cost/benefit analyses, the accident-related on-site exposures were calculated using the best estimate exposure components applied over the on-site cleanup period.On-site Cleanup Period In the cost/benefit analyses, the accident-related on-site exposures were calculated over a 10-year cleanup period.Present Worth On-site Cleanup Cost per Accident The estimated cleanup cost for severe accidents was assumed to be$1.5E+09/accident (undiscounted).

This value was derived by the NRC in Reference 16, Section 5.7.6.1, Cleanup and Decontamination.

This cost is the sum of equal annual costs over a 10-year cleanup period. At a 7%discount rate, the present value of this stream of costs is approximately

$1.1E+09.F.4.1 OFF-SITE EXPOSURE COST Accident-Related Off-Site Dose Costs Off-site doses were determined using the MACCS2 model developed for Seabrook Station. Costs associated with these doses were calculated using the following equation: APE = (FDp -FAD,)R (1)Where: APE = monetary value of accident risk avoided due to population doses, after discounting R = monetary equivalent of unit dose, ($/person-rem)

F = accident frequency (events/yr)

Dp = population dose factor (person-rems/event)

S = status quo (current conditions)

A = after implementation of proposed action r = real discount rate tf = analysis period (years).Using the values for r, tf, and R given above, the present worth of accident-related off-site dose costs is: WP = ($2.15E + 04)(F, Dp, -FAD PA)F.4.2 OFF-SITE ECONOMIC COST Accident-Related Off-site Property Damage Costs Off-site damage was determined using the MACCS2 model developed for Seabrook Station. Costs associated with accident-related off-site property damages were calculated using the following equation: Seabrook Station Unit 1 Page F-66 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives AOC = (FSPs -FAPD )I r Where: AOC = monetary value of accident risk avoided due to offsite property damage, after discounting F = accident frequency (events/yr)

PD = offsite property loss factor (dollars/event) r = real discount rate tf = analysis period (years).F.4.3 ON-SITE EXPOSURE COST Methods for Calculating Averted Costs Associated with Onsite Accident Dose Costs a) Immediate Doses (at time of accident and for immediate management of emergency)

For the case where the plant is in operation, the equations in Reference 16 can be expressed as: W'= -F F-1 )R 1 Where: Wio = monetary value of accident-risk avoided due doses, after discounting R = monetary equivalent of unit dose, ($/person-rem)

F = accident frequency (events/yr)

D1o = immediate occupational dose (person-remis/event)

S = status quo (current conditions)

A,= after implementation of proposed action r = real discount rate tf = analysis period (years).(1)to immediate The values used are: R = $2000/person rem r = 0.07 Djo = 3,300 person-rems

/accident (best estimate)The license extension time of 20 years is used for tf.For the basis discount rate, assuming FA is zero, the best estimate of the limiting savings is: r= (FSD]Q-)R-.-7"2o

= 3300

• F *$2000 e-e.07= F * $6,600,000

• 10. 763= F * $0. 71E + 08, ($).Seabrook Station Unit 1 License Renewal Application Page F-67 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives b) Long-Term Doses (process of cleanup and refurbishment or decontamination)

For the case where the plant is in operation, the equations in Reference 16 can be expressed as: WLTO = (FsDLTOS -FADLTO *1e ,r 1 1-e (2)r rm Where: Wio = monetary value.of accident risk avoided long-term doses, after discounting, $M = years over which long-term doses accrue.The values used are: R = $2000/person rem r = 0.07 DLTO = 20,000 person-rem

/accident (best estimate)m = "as long as 10 years" The license extension period of 20 years is used for tf.For the discount rate of 7%, assuming FA is zero, the best estimate of the limiting savings is: WLTo = (FsDLo R, ert e-1 LTOSLT~r~

r rm= (Fs20000)$2000 , l-e- 0720 ° I -e- °*.07 .07*10= Fs * $40, 000, 000 *10. 763 *0. 719= Fs* $3.1 OE + 08, ($).c) Total Accident-Related Occupational (On-site)

Exposures Combining equations (1) and (2) above, using delta (A) to signify the difference in accident frequency resulting from the proposed actions, and using the above numerical values, the long term accident related on-site (occupational) exposure avoided (AOE) is: Best Estimate: AOE= W 1 o+ WLTo= F*$(0.71+3.1)E+08=

F*$3.81E+08($)

F.4.4 ON-SITE ECONOMIC COST Methods for Calculation of Averted Costs Associated with Accident-Related On-Site Property Damage a) Clean up/Decontamination Reference 16 assumes a total cleanup/decontamination cost of $1.5E+09 as a reasonable estimate and this same value was adopted for these analyses.Considering a 10-year cleanup period, the present value of this cost is: Seabrook Station Unit 1 Page F-68 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives PVCD ~CcD {e -rn, ~kMj r Where: PVCD = Present value of the cost of cleanup/decontamination.

COD = Total cost of the cleanup/decontamination effort.m = Cleanup period.r = Discount rate.Based upon the values previously assumed: P J/C = $1.5E +o 9 -oe07*10 .07)PVcD = $1.079E + 09 This cost is integrated over the term of the proposed license extension as follows: UCD = PVCD l-e-r Based upon the values previously assumed: UCD = $1.079E + 09 [10.763]UcD = $1.161E +10 b) Replacement Power Costs Replacement power costs, URP, are an additional contributor to onsite costs.These are calculated in accordance with NUREG/BR-0184, Section 5.6.7.2.(1)

Since replacement power will be needed for the remainder of the anticipated generating plant life following a severe accident, long-term power replacement calculations have been used. The calculations are based on the 910 MWe reference plant, and are appropriately scaled for the 1,290 MWe Seabrook Station. The calculation conservatively used the gross electrical output of 1,290 MWe rather than the net electrical output of 1,245 MWe. The present value of replacement power is calculated as follows: ($1.2E + 08 (Ratepwr)-VP (91OMWe)( erf-r (1) The section number for Section 5.6.7.2 apparently contains a typographical error. This section is a subsection of 5.7.6 and follows 5.7.6.1. However, the section number as it appears in the NUREG will be used in this document.Seabrook Station Unit 1 Page F-69 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Where: PVRP = Present value of the cost of replacement power for a single event.tf = Analysis period (years).R = Discount rate.Ratepwr -Rated power of the unit The $1.2E+08 value has no intrinsic meaning but is a substitute for a string of non-constant replacement power costs that occur over the lifetime of a"generic" reactor after an event (from Reference 16). This equation was developed per NUREG/BR-0184 for discount rates between 5% and 10%only.For discount rates between 1% and 5%, Reference 16 indicates that a linear interpolation is appropriate between present values of $1.2E+09 at 5% and$1.6E+09 at 1%. So for discount rates in this range the following equation was used to perform this linear interpolation.

PVR= ($1.6E +09)-[($1.6E

+09)-($1.2E

+ 09)] [ 1% Ratepwr Where: r, = Discount rate (small), between 1% and 5%.Ratepwr = Rated power of the unit To account for the entire lifetime of the facility, URP was then calculated from PVRP, as follows: U (PV(1 -e-r'f)2 r Where: URP = Present value of the cost of replacement power over the life of the facility.Again, this equation is only applicable in the range of discount rates from 5%to 10%. NUREG/BR-0184 states that for lower discount rates, linear interpolations for URP are recommended between $1.9E+10 at 1% and$1.2E+10 at 5%. The following equation was used to perform these linear interpolations:

Where: r. = Discount rate (small), between 1% and 5%.Ratepwr = Rated power of the unit c) Repair and Refurbishment It is assumed that the plant would not be repaired or refurbished; therefore, there is no contribution to averted onsite costs from this source.Seabrook Station Unit 1 Page F-70 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives d) Total Onsite Property Damage Costs The net present value of averted onsite damage costs is, therefore:

AOSC = F * (UCD + UPP)Where: F = Annual frequency of the event.UCD = Present value cost of clean up/decontamination URP = Present value cost of replacement power F.4.5 TOTAL COST OF SEVERE ACCIDENT RISK / MAXIMUM BENEFIT Cost/benefit evaluation of the maximum benefit is baseline risk of the plant converted dollars by summing the contributors to cost.Maximum Benefit Value = (APE + AOC + ACE + AOSC)Where: APE = present value of averted public exposure ($), AOC = present value of averted offsite property damage costs ($), ACE = present value of averted occupational exposure ($), AOSC = present value of averted onsite costs ($)For Seabrook Station, this value is $818,721 as shown below.Parameter Present Dollar Value ($)Averted Public Exposure $230,433 Averted Offsite Costs $253,299 Averted Occupational Exposure $5498 Averted Onsite Costs $329,492 Total $818,721 The costs are dominated by the late large release category.

The dominant accident sequences that result in these release categories are largely the result of loss of off-site power, fire, and seismic-initiating events. These initiating events are explicitly modeled in the PRA.F.5 SAMA IDENTIFICATION A list of SAMA candidates was developed by reviewing the major contributors to CDF and population dose based on the plant-specific risk assessment and the standard PWR list of enhancements from NEI 05-01, "Severe Accident Mitigation Alternatives (SAMA) Analysis Guidance Document," November 2005 (Reference 20). This section discusses the SAMA selection process and its results.F.5.1 PRA IMPORTANCE The top core damage sequences and the components/systems having the greatest potential for risk reduction were examined to determine whether additional SAMAs could be identified from these sources.Seabrook Station Unit 1 Page F-71 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives The current plant procedures and training meet current industry standards.

There were no additional specific procedure improvements identified that would affect the result of the HEP calculations.

Therefore, no SAMA items were added to the plant-specific list of SAMAs as a result of the human actions with risk reduction worth (RRW) greater than 1.005. The human actions shown on Tables F.3.1.1.1-2 and F.3.2.1-2 are, therefore, not identified as potential SAMA candidates.

Use of Importance Measures Risk reduction worth (RRW) of the components in the baseline model was used to identify the basic events that could have a significant potential for reducing risk. Components with RRW >1.005 were identified as the most important components.

A similar review was performed on a systems basis.The components and systems were reviewed to ensure that each component and system is covered by an existing SAMA item or was added to the list if not covered by an existing SAMA.Use of the Top Sequences The top sequences leading to core melt were reviewed.

A key result is that no single PRA sequence makes up a large fraction of the core damage frequency.

The sequences were reviewed to ensure that initiators and failures identified in the sequences were either covered by existing SAMAs or were added to the list of plant- specific SAMAs.F.5.2 PLANT IPE The Seabrook Station IPE concluded that there are no fundamental weaknesses or vulnerabilities with regard to severe accidents at Seabrook Station. Several potential improvements were identified that could reduce overall risk. These items are included in the list of SAMA candidates.

F.5.3 PLANT IPEEE The IPEEE concluded that there are no vulnerabilities to severe accident risk from external events. Several potential improvements were identified that could reduce overall risk. These items are included in the list of SAMA candidates.

F.5.4 INDUSTRY SAMA CANDIDATES The generic PWR enhancement list from Table 14 of Reference 20 was included in the list of Phase I SAMA candidates to ensure adequate consideration of potential enhancements identified by other industry studies.F.5.5 PLANT STAFF INPUT TO SAMA CANDIDATES The plant staff provided plant-specific items that were included in the evaluation.

The process used to identify plant-specific SAMA candidates included a detailed review of the IPE and IPEEE reports and associated potential plant enhancements to reduce severe accident risk, presentation of Seabrook Station Unit 1 Page F-72 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives the license renewal and SAMA processes to plant engineering and plant management personnel and general solicitation of possible SAMA candidates, convening expert panel to review/discuss both industry-generic and plant-specific SAMA candidates.

Plant-specific SAMA candidates are identified in the list of SAMA candidates by their source reference.

F.5.6 LIST OF PHASE I SAMA CANDIDATES Table F.5.6-1 provides the combined list of potential SAMA candidates considered in the Seabrook Station SAMA analysis.

One hundred-ninety SAMA candidates were identified for consideration.

Seabrook Station Unit 1 License Renewal Application Page F-73 3' CD CD M CD 0 0 CDcn-CD 0 0 0, CD 7'_01 Table F.5.6-1 List of SAMA Candidates Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)1 Provide additional DC battery capacity.

Extended DC power 1, 3, 6, 10, availability during an SBO. AC/DC 11, 12, 17 2 Replace lead-acid batteries with fuel cells. Extended DC power AC/DC 6,10 2_ Relc edaiatre ihfeelavailability during an SBO.3 Add additional battery charger or portable, diesel-driven battery charger to Improved availability of DC AC/DC 5 existing DC system. power system.4 Improve DC bus load shedding.

Extended DC power AC/DC 1,7 availability during an SBO.5 Provide DC bus cross-ties.

Improved availability of DC AC/DC 6 power system.6 Provide additional DC power to the 120/240V vital AC system. Increased availability of the AC/DC 3 120 V vital AC bus.7 Add an automatic feature to transfer the 120V vital AC bus from normal to Increased availability of the AC/DC 5 standby power. 120 V vital AC bus.Increase training on response to loss of two 120V AC buses which causes Improved chances of 8 inadvertent actuation signals. successful response to loss of AC/DC 5 two 120V AC buses.9 Provide an additional diesel generator.

Increased availability of on- AC/DC 1,6, 10, 11, site emergency AC power. 12 10 Revise procedure to allow bypass of diesel generator trips. Extended diesel generator AC/DC 15 operation.

11 Improve 4.16-kV bus cross-tie ability. Increased availability of on- AC/DC 1,6, 11, 12 site AC power.12 Create AC power cross-tie capability with other unit (multi-unit site). Increased availability of on- AC/DC 1,7,13 site AC power._____________

13 Install an additional, buried off-site power source. Reduced probability of loss of AC/DC 1 ofF.site power.14 Install a gas turbine generator.

Increased availability of on- AC/DC 1,6 site AC power.CD CD>CD CL X>CD r CD 0)...CD CD 0 CD 0 CD a)n-D CD 0 CD R'0 01 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)15 Install tornado protection on gas turbine generator.

Increased availability of on- AC/DC 18 site AC power.Increased availability of power 16 Improve uninterruptible power supplies.

supplies supporting front-line AC/DC 6 equipment.

17 Create a cross-tie for diesel fuel oil (multi-unit site). Increased diesel generator AC/DC 1 availability.

18 Develop procedures for replenishing diesel fuel oil. Increased diesel generator AC/DC 1 availability.

19 Use fire water system as a backup source for diesel cooling. Increased diesel generator AC/DC 1 availability.

20 Add a new backup source of diesel cooling. Increased diesel generator AC/DC 1 availability.

Increased probability of recovery from failure of 21 Develop procedures to repair or replace failed 4 KV breakers, breakers that transfer 4.16 kV AC/DC 1 non-emergency buses from unit station service transformers.

Reduced human error 22 In training, emphasize steps in recovery of off-site power after an SBO. probability during off-site AC/DC 1 power recovery.Improved ofF.site power 23 Develop a severe weather conditions procedure.

recovery following external.

AC/DC 1, 3,17 weather-related events.Improved off-site power 24 Bury off-site power lines. reliability during severe AC/DC 1 weather.25 Install an independent active or passive high pressure injection system. Improved prevention of core Core Cooling 5, 6 melt sequences.

C)S CD-n, C', CD CD >> CD Q. L CL X CD M CnM OCD CD 0)CD 0 CD00 CD C)M 0.0)>03 Mo CD-4 a)Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Reduced frequency of core 26 Provide an additional high pressure injection pump with independent diesel. melt from small LOCA and Core Cooling 5 SBO sequences.

27 Revise procedure to allow operators to inhibit automatic vessel Extended HPCI and RCIC Core Cooling 5 depressurization in non-ATWS scenarios, operation.

28 Add a diverse low pressure injection system. Improved injection capability.

Core Cooling 5, 6 29 Provide capability for alternate injection via diesel-driven fire pump. Improved injection capability.

Core Cooling 5 30 Improve ECCS suction strainers.

Enhanced reliability of ECCS Core Cooling 22 suction.31 Add the ability to manually align emergency core cooling system Enhanced reliability of ECCS Core Cooling 5 recirculation.

suction.32 Add the ability to automatically align emergency core cooling system to Enhanced reliability of ECCS Core Cooling 5 recirculation mode upon refueling water storage tank depletion.

suction.Extended reactor water Provide hardware and procedure to refill the reactor water storage tank once storage tank capacity in the 33 it reaches a specified low level, event of a steam generator Core Cooling 5, 10 tube rupture (or other LOCAs challenging RWST capacity).

Continuous source of water to the safety injection pumps during a LOCA event, since water released from a breach of the primary system collects 34 Provide an in-containment reactor water storage tank. in the in-containment reactor Core Cooling 10 water storage tank, and thereby eliminates the need to realign the safety injection pumps for long-term post-LOCA recirculation.

Throttle low pressure injection pumps earlier in medium or large-break Extended reactor water Core Cooling 5 LOCAs to maintain reactor water storage tank inventory, storage tank capacity.0)CD Ci)CD CD '0>CD~5' M 0CL.CDm CD 0 3'CD CD 0)U) -0 CDc,* 0> C 0 CD'1 4-4 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Reduced human error 36 Emphasize timely recirculation alignment in operator training, probability associated with Core Cooling 5 recirculation failure.For a plant like the Westinghouse AP600, where the chemical and volume 37 Upgrade the chemical and volume control system to mitigate small LOCAs. control system cannot mitigate Core Cooling 5 a small LOCA, an upgrade would decrease the frequency of core damage.38 Change the in-containment reactor water storage tank suction from four Reduced common mode Core Cooling 5 check valves to two check and two air-operated valves, failure of injection paths.Reduced common cause failure of the safety injection system. This SAMA was originally intended for the 3 Replace two of the four electric safety injection pumps with diesel-powered Westinghouse-CE System pumps. 80+, which has four trains of Core Cooling 5, 10 safety injection.

However, the intent of this SAMA is to provide diversity within the high- and low-pressure safety injections systems.Improved chance of successful operation during Provide capability for remote, manual operation of secondary side pilot- station blackout events in 40 operated relief valves in a station blackout.

which high area temperatures Core Cooling 5 may be encountered (no ventilation to main steam areas).0 CD CD>>CD> CD~CL CDOM w;M CD00 CD0)(0 CD 7'-4 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Allows low pressure emergency core cooling 41 Create a reactor coolant depressurization system. system injection in the event Core Cooling 5,10 of small LOCA and high-pressure safety injection failure.Allows low pressure emergency core cooling 42 Make procedure changes for reactor coolant system depressurization.

system injection in the event Core Cooling 5 of small LOCA and high-pressure safety injection failure.43 Add redundant DC control power for SW pumps. Increased availability of SW. Cooling Water 3 Elimination of ECCS 44 Replace ECCS pump motors with air-cooled motors. dependency on component Cooling Water 1 cooling system.Enhance procedural guidance for use of cross-tied component cooling or Reduced frequency of loss of 45 service water pumpsi component cooling water and Cooling Water 1 service water.46 Add a service water pump. Increased availability of Cooling Water 6 cooling water.Reduced potential for loss of 47 Enhance the screen wash system. SW due to clogging of Cooling Water 23 screens.Reduced frequency of loss of component cooling water Cap downstream piping of normally closed component cooling water drain initiating events, some of 48 and vent valves, which can be attributed to Cooling Water 5 catastrophic failure of one of the many single isolation valves.Enhance loss of component cooling water (or loss of service water) Reduced potential for reactor 49 coolant pump seal damage Cooling Water 5 procedures to facilitate stopping the reactor coolant pumps. due to pump bearing failure.0)3 CD-n CD CD >> CD o0~~CD 00 3I~

CDD CD 0 0 CD 0 CD Q*0 01 0)TO CD (o Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)50 Enhance loss of component cooling water procedure to underscore the Reduced probability of reactor Cooling Water 5 desirability of cooling down the reactor coolant system prior to seal LOCA. coolant pump seal failure.Improved success of operator 51 Additional training on loss of component cooling water. actions after a loss of Cooling Water 5 component cooling water.Reduced effect of loss of component cooling water by 52 Provide hardware connections to allow another essential raw cooling water providing a means to maintain Cooling Water 5 system to cool charging pump seals. the charging pump seal injection following a loss of normal cooling water.Increased time before loss of On loss of essential raw cooling water, proceduralize shedding component component cooling water (and 53 reactor coolant pump seal Cooling Water 5 3 cooling water loads to extend the component cooling water heat-up time, failure) during loss of essential raw cooling water sequences.

Increased time before 54 Increase charging pump lube oil capacity.

charging pump failure due to Co lube oil overheating in loss of oling Water cooling water sequences.

Reduced frequency of core Install an independent reactor coolant pump seal injection system, with damage from loss of dedicated diesel. component cooling water, Cooling Water 5, 10 service water, or station blackout.Reduced frequency of core Install an independent reactor coolant pump seal injection system, without damage from loss of 56 dedicated diesel, component cooling water or Cooling Water 5, 10 service water, but not a station blackout.0)CD C', CD>CD>0> CD CL X CD m ,.CD CD 0 M~

r- C, 6' C CD 0)C',-CD 0;0 CD 0)0)CD'1 00 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Reduced frequency of core damage from loss of 57 Use existing hydro test pump for reactor coolant pump seal injection, component cooling water or Cooling Water service water, but not a station blackout, unless an alternate power source is used.58 Install improved reactor coolant pump seals. Reduced likelihood of reactor Cooling Water 5 coolant pump seal LOCA.Reduced likelihood of loss of 59 Install an additional component cooling water pump. component cooling water leading to a reactor coolant Cooling Water 5 pump seal LOCA.Reduced frequency of loss of reactor coolant pump seal cooling if spurious high 60 Prevent makeup pump flow diversion through the relief valves. pressure injection relief valve Cooling Water 5 opening creates a flow diversion large enough to prevent reactor coolant pump seal injection.

Change procedures to isolate reactor coolant pump seal return flow on loss Reduced frequency of core 61 of component cooling water, and provide (or enhance) guidance on loss of damage due to loss of seal Cooling Water 5 injection during seal LOCA. cooling.Extended high pressure 62 Implement procedures to stagger high pressure safety injection pump use injection prior to overheating Cooling Water 5 after a loss of service water. following a loss of service water.63 Use fire prevention system pumps as a backup seal injection and high Reduced frequency of reactor Cooling Water 5 pressure makeup source, coolant pump seal LOCA.Implement procedure and hardware modifications to allow manual alignment Improved ability to cool 64 of the fire water system to the component cooling water system, or install a residual heat removal heat Cooling Water 5 component cooling water header cross-tie, exchangers.

0)CD C/, CD CD >> CD o0.CL X-CD MD M~

5CD CD 0 0 CD 0 CD 9n 020 02 CD 7'Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Reduced chance of loss of Feedwater/

65 Install a digital feed water upgrade. main feed water following a 1 plant trip. Condensate 66 Create ability for emergency connection of existing or new water sources to Increased availability of Feedwater/

5 feedwater and condensate systems. feedwater.

Condensate 67 Install an independent diesel for the condensate storage tank makeup Extended inventory in CST Feedwater/

5 pumps. during an SBO. Condensate 68 Adda motor-driven feedwater pump. Increased availability of Feedwater/

1,3 feedwater.

Condensate 69 Install manual isolation valves around auxiliary feedwater turbine-driven Reduced dual turbine-driven Feedwater/

steam admission valves. pump maintenance Condensate unavailability.

Eliminates the need for local 70 Install accumulators for turbine-driven auxiliary feedwater pump flow control manual action to align nitrogen Feedwater/

5 valves. bottles for control air following Condensate a loss of off-site power.71 Install a new condensate storage tank (auxiliary feedwater storage tank). Increased availability of the Feedwater/

auxiliary feedwater system. Condensate 5,10 72 Modify the turbine-driven auxiliary feedwater pump to be self-cooled.

Improved success probability Feedwater/

5 during a station blackout.

Condensate Extended auxiliary feedwater availability during a station Proceduralize local manual operation of auxiliary feedwater system when blackout.

Also provides a Feedwater/

73 control power is lost. success path should auxiliary Condensate feedwater control power be lost in non-station blackout sequences.

74 Provide hookup for portable generators to power the turbine-driven auxiliary Extended auxiliary feedwater Feedwater/

5, 10 feedwater pump after station batteries are depleted.

availability.

Condensate 75 Increased availability of steam Feedwater/

5 Use fire water system as a backup for steam generator inventory, generator water supply. Condensate CD-n, CD)CD>CD>> CD o0.C02> CD;00 3*CD CDD CD 0 0 CD 0 9D5'0 CD T1 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Allows greater inventory for Change failure position of condenser makeup valve if the condenser makeup the auxiliary feedwater pumps Feedwater/

76 Change failuroen posion lossof cirondenser.

makepvlveifhby preventing condensate 5 valve fails open on loss of air or power. storage tank flow diversion to Condensate the condenser.

Provide a passive, secondary-side heat-rejection loop consisting of a Reduced potential for core Feedwater/

77 condenser and heat sink. damage due to loss-of- 5 feedwater events. Condensate 78 Modify the startup feedwater pump so that it can be used as a backup to the Increased reliability of decay Feedwater/

10 emergency feedwater system, including during a station blackout scenario, heat removal. Condensate 79 Replace existing pilot-operated relief valves with larger ones, such that only Increased probability of Feedwater/

one is required for successful feed and bleed. successful feed and bleed. Condensate Increased availability of 80 Provide a redundant train or means of ventilation, components dependent on HVAC 1 room cooling.81 Add a diesel building high temperature alarm or redundant louver and Improved diagnosis of a loss HVAC 1 thermostat, of diesel building HVAC.Increased availability of 82 Stage backup fans in switchgear rooms. ventilation in the event of a HVAC 5 loss of switchgear ventilation.

83 Add a switchgear room high temperature alarm. Improved diagnosis of a loss HVAC 5 of switchgear HVAC.84 Create ability to switch emergency feedwater room fan power supply to Continued fan operation in a HVAC 5 station batteries in a station blackout.

station blackout.Increased ability to vent 85 Provide cross-unit connection of uninterruptible compressed air supply. containment using the IA/Nitrogen 3 hardened vent.86 Modify procedure to provide ability to align diesel power to more air Increased availability of I compressors.

instrument air after a LOOP. A/Nitrogen 18 87 Replace service and instrument air compressors with more reliable Elimination of instrument air compressors which have self-contained air cooling by shaft driven fans. system dependence on IA/Nitrogen 5 service water cooling.0 CID C')CD CD >>CD o0.-ý X~CD CDO CID~ Q)

CD CD XD CD CD a, 0.W, CD C,, 0)0 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)88 Install nitrogen bottles as backup gas supply for safety relief valves. Extended SRV operation time. IA/Nitrogen 18 89 Improve SRV and MSIV pneumatic components.

Improved availability of SRVs lA/Nitrogen 6 and MSIVs.Enhanced debris cool ability, 90 Create a reactor cavity flooding system. reduced core concrete Containment 1,7,11,12 interaction, and increased Phenomena fission product scrubbing.

91 Install a passive containment spray system. Improved containment spray Containment 6,14 capability.

Phenomena 92 Use the fire water system as a backup source for the containment spray Improved containment spray Containment 4,6 system. capability.

Phenomena Increased decay heat removal 93 Install an unfiltered, hardened containment vent. capability for non-ATWS Containment 6, 8, 9 events, without scrubbing Phenomena released fission products.Increased decay heat removal 94 Install a filtered containment vent to remove decay heat. Option 1: Gravel capability for non-ATWS Containment Bed Filter; Option 2: Multiple Venturi Scrubber events, with scrubbing of Phenomena 6, 8, 9,14 released fission products.95 Enhance fire protection system and standby gas treatment system hardware Improved fission product Containment 9 and procedures.

scrubbing in severe accidents.

Phenomena Reduced likelihood of Containment 96 Provide post-accident containment inserting capability, hydrogen and carbon Phenomena 6, 7, 12 monoxide gas combustion.

Increased cooling and containment of molten core debris. Molten core debris Create a large concrete crucible with heat removal potential to contain escaping from the vessel is Containment 97 molten core debris, contained within the crucible Phenomena 6,8,9 and a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.=)3 CD-n, W, CD (D >> CD C)0 CL. XýCD M L- CD CDO CD 0~0)cc CD"OD Wr c&

0 CD CD:3 CD 0)0 CD 0*0 X,, 0)Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Increased cooling and containment of molten core debris. Refractory material would be placed underneath the reactor vessel such that a molten core falling on the Containment 13 98 Create a core melt source reduction system. material would melt and Phenomena combine with the material.Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.99 Strengthen primary/secondary containment (e.g., add ribbing to containment Reduced probability of Containment 5,6,10,14 sel.containment over- Pheontimena

,6 1,1 shell). !pressurization.

Phenomena 100 Increase depth of the concrete base mat or use an alternate concrete Reduced probability of base Containment 10 material to ensure melt-through does not occur. mat melt-through.

Phenomena Increased potential to cool a 101 Provide a reactor vessel exterior cooling system. molten core before it causes Containment 10 vessel failure, by submerging Phenomena the lower head in water.102 Construct a building to be connected to primary/secondary containment and Reduced probability of Containment maintained at a vacuum. containment over- Phenomena 6,10 pressurization.

Improved arrest of core melt Containment 103 Institute simulator training for severe accident scenarios, progress and prevention of Phenomena containment failure.Increased piping surveillance to identify leaks prior to Containment 104 Improve leak detection procedures.

complete failure. Improved Phenomena6 leak detection would reduce LOCA frequency.

0)3 CD-n1 U)CD CD>CD>CD o0.-CD CDO CD 0_0 CD-n, CD a)CD 0 0 CD 0 0 CD 00 01 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)105 Delay containment spray actuation after a large LOCA. Extended reactor water Containment storage tank availability.

Phenomena Extended time over which water remains in the reactor 106 Install automatic containment spray pump header throttle valves, water storage tank, when full Coment containment spray flow is not needed.107 Install a redundant containment spray system. Increased containment heat Containment 5, 10 removal ability. Phenomena Install an independent power supply to the hydrogen control system using 108 either new batteries, a non-safety grade portable generator, existing station Reduced hydrogen detonation Containment 5,10 batteries, or existing AC/DC independent power supplies, such as the potential.

Phenomena security system diesel.109 Install a passive hydrogen control system. Reduced hydrogen detonation Containment 5, 10 potential.

Phenomena Erect a barrier that would provide enhanced protection of the containment Reduced probability of Containment 110 walls (shell) from ejected core debris following a core melt scenario at high containment failure. Phenomena pressure.Install additional pressure or leak monitoring instruments for detection of Reduced ISLOCA frequency.

Containment 4,7, 11,12, ISLOCAs. Bypass 15 Add redundant and diverse limit switches to each containment isolation Reduced frequency of Containment 112 valve. containment isolation failure Bypass 1 and ISLOCAs.113 Increase leak testing of valves in ISLOCA paths. Reduced ISLOCA frequency.

Containment 1 Bypass 114 Install selF.actuating containment isolation valves. Reduced frequency of Containment isolation failure. Bypass 115 Locate residual heat removal (RHR) inside containment Reduced frequency of Containment 14 ISLOCA outside containment.

Bypass 116 Ensure ISLOCA releases are scrubbed.

One method is to plug drains in Scrubbed ISLOCA releases.

Containment 1 potential break areas so that break point will be covered with water. Bypass CD-n, C', CD CD >>CD o0.-L X CD M L>CD CDO Cn ;.

CD CD CD CD 0 W, CD a)0 0 C')0 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Increased likelihood that LOCAs outside containment are identified as such. A plant had a scenario in which an Containment 117 Revise EOPs to improve ISLOCA identification.

RHR ISLOCA could direct Bypass initial leakage back to the pressurizer relief tank, giving indication that the LOCA was inside containment.

118 Improve operator training on ISLOCA coping. Decreased ISLOCA Containment consequences.

Bypass 119 Institute a maintenance practice to perform a 100% inspection of steam Reduced frequency of steam Containment 5,10 119_ generator tubes during each refueling outage. generator tube ruptures.

Bypass 120 Replace steam generators with a new design. Reduced frequency of steam Containment 5 generator tube ruptures.

Bypass Increase the pressure capacity of the secondary side so that a steam Eliminates release pathway to Containment 121 generator tube rupture would not cause the relief valves to lift. the environment following a Bypass 5, 10 steam generator tube rupture.Install a redundant spray system to depressurize the primary system during a Enhanced depressurization Containment 5,10 122 steam generator tube rupture. capabilities during steam Bypass generator tube rupture.Backup method to using Proceduralize use of pressurizer vent valves during steam generator tube pressurizer sprays to reduce Containment 123 primary system pressure 5 rupture sequences.

following a steam generator Bypass tube rupture.124 Provide improved instrumentation to detect steam generator tube ruptures, Improved mitigation of steam Containment 5 10 such as Nitrogen-16 monitors.

generator tube ruptures.

Bypass Route the discharge from the main steam safety valves through a structure Reduced consequences of a Containment 125 where a water spray would condense the steam and remove most of the steam generator tube rupture. Bypass10 fission products.126 Install a highly reliable (closed loop) steam generator shell-side heat removal Reduced consequences of a Containment 5 ,system that relies on natural circulation and stored water sources steam generator tube rupture. Bypass 0)-n, Cln CD CD >>CD 0 =3 CL x~CD L>CD CD 0)CD 00 CDW CD 0)Ch)CD00;0 x 0 0)CD 71 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)127 Revise emergency operating procedures to direct isolation of a faulted steam Reduced consequences of a Containment 5 generator.

steam generator tube rupture. Bypass Improved scrubbing of steam Containment 128 Direct steam generator flooding after a steam generator tube rupture, prior to generator tube rupture Bpass5 core damage. releases.

Bypass 129 Vent main steam safety valves in containment.

Reduced consequences of a Containment 5, 10 steam generator tube rupture. Bypass 130 Add an independent boron injection system. Improved availability of boron ATWS 18__-____ injection during ATWS.13, 1 Add a system of relief valves to prevent equipment damage from pressure Improved equipment ATWS 19 spikes during an ATWS. availability after an ATWS.132 Provide an additional control system for rod insertion (e.g., AMSAC). Improved redundancy and ATWS 18 reduced ATWS frequency.

Increased ability to remove 133 Install an ATWS sized filtered containment vent to remove decay heat. reactor heat from ATWS ATWS 6 events.Affords operators more time to perform actions. Discharge of a substantial fraction of steam to the main condenser (i.e., as opposed to into the primary containment) affords the 134 Revise procedure to bypass MSIV isolation in turbine trip ATWS scenarios, operator more time to perform ATWS 1,20 actions (e.g., SLC injection, lower water level, depressurize RPV) than if the main condenser was unavailable, resulting in lower human error probabilities.

0)CD C,, CD CD >-I CD _0> CD CD M 6' CD CDo CD 0 0 CD 0 0 0)00 00 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Allows immediate control of low pressure core injection.

On failure of high pressure 135 Revise procedure to allow override of low pressure core injection during an core injection and condensate, ATWS 16 ATWS event. some plants direct reactor depressurization followed by five minutes of automatic low pressure core injection.

136 Install motor generator set trip breakers in control room. Reduced frequency of core ATWS 5 136______

Irdamage due to an ATWS.Decreased time required to insert control rods if the 137 Provide capability to remove power from the bus powering the control rods. reactor trip breakers fail (during a loss of feedwater ATWS ATWS which has rapid pressure excursion).

Reduced frequency of internal 138 Improve inspection of rubber expansion joints on main condenser.

flooding due to failure of Internal Flooding circulating water system expansion joints.139 Modify swing direction of doors separating turbine building basement from Prevents flood propagation.

Internal Flooding 5 areas containing safeguards equipment.

Increased availability of 140 Increase seismic ruggedness of plant components.

necessary plant equipment Seismic Risk 3,10 during and after seismic events.Increased availability of fire 141 Provide additional restraints for C02 tanks. protection given a seismic Seismic Risk 17 event.Decreased probability of 142 Replace mercury switches in fire protection system. spurious fire suppression Fire Risk 7 system actuation.

143 Upgrade fire compartment barriers.

Decreased consequences of a Fire Risk 7________fire.I 0 CD-n, C0, CD CD >>CD C)0-CD r CDO CD 0 r- U)39* (D CD W CD 0 0 CD 0=CD~0~0 CD 7'(0 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)144 Install additional transfer and isolation switches.

Reduced number of spurious Fire Risk 18 actuations during a fire.145 Enhance fire brigade awareness.

Decreased consequences of a Fire Risk 7 fi re.146 Enhance control of combustibles and ignition sources. Decreased fire frequency and Fire Risk 7 consequences.

Reduced probability of a large 147 Install digital large break LOCA protection system. break LOCA (a leak before Other 5 break).148 Enhance procedures to mitigate large break LOCA. Reduced consequences of a Other 7 large break LOCA.Install computer aided instrumentation system to assist the operator in Improved prevention of core 149 Isalcmueaieintuettosytmtasitteoeaoin melt sequences by making Other 6 assessing post-accident plant status. melt actions more Otherle operator actions more reliable.Improved prevention of core 150 Improve maintenance procedures.

melt sequences by increasing Other 6 reliability of important equipment.

Improved likelihood of success 151 Increase training and operating experience feedback to improve operator of operator actions taken in Other 6 response.

response to abnormal conditions.

Reduced consequences of 152 Develop procedures for transportation and nearby facility accidents, transportation and nearby Other 7 facility accidents.

CD-n, Ci, CD CD '> CD o0.CD CD M L- CD CDO cn ;:.

3' CD CD 0)CD 0 0 0 CDC, (0 0 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA I Source (1)Prevents secondary side depressurization should a steam line break occur upstream of the main steam 153 Install secondary side guard pipes up to the main steam isolation valves, isolation valves. Also guards Other 5, 10 against or prevents consequential multiple steam generator tube ruptures following a main steam line break event.Improve reliability of onsite Modify SEPS d to accommodate: (a) automatic bu ldi b) power; reduce SBO CDF 154 design o automatic bus oag, contribution; remove AC/DC A automatic bus alignment.

dependence on operator action.SEPS DG installed and 155 Install alternate emergency AC power source (e.g., swing diesel). credited in PRA to power Bus AC/DC A E5 or Bus E6.Improve offsite power Install alternate offsite power source that bypasses the switchyard.

For reliability and independence of example, use campus power source to energize Bus E5 or E6. switchyard and SF6 bus duct; AC/DC A allow restoration of offsite power within a few hours.Reduce CDF of long term 157 Provide independent AC power source for battery chargers.

For example, SBO sequences; extend AC/DC A provide portable generator to charge station battery. battery life to allow additional time for recovery.Reduce CDF of long term 158 Provide enhanced procedural direction for cross-tie of batteries within each SBO sequences; extend AC/DC A train. battery life to allow additional time for recovery.Reduce CDF of long term 159 Install additional batteries.

SBO sequences; extend AC/DC A battery life to allow additional time for recovery.0)=r 3 CD-n, 0, CD CD >-0> CD~0=>0~CD r 00 3~

CD-CD 0 0;0 CD CDD 0)0 CD Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)160 Enhancements to address loss of SF6-type sequences.

SF6 enhancements improve AC/DC A offsite power reliability.

Alternate cooling to both EDGs would reduce CDF long Modify EDG jacket heat exchanger service water supply and return to allow term sequences involving 161 timely alignment of alternate cooling water source (supply & drain) from LOOP and loss of SW /cooling AC/DC A firewater, RMW, DW, etc. tower. A loss of service water f cooling tower with a LOOP could result in EDG failure and non-recovery.

Extend long term operation of EFW without operator action for CST makeup for 162 Increase the capacity margin of the CST. sequences that do not go to Core Cooling A cold shutdown.

Enhance CST margin for design-basis seismic event with cooldown via SG and transition to RHR.Reduce CDF of SBO sequences by improving overall reliability of EFW system independent of AC power. An additional pump 163 Install third EFW pump (steam-driven).

might also have a Level 2 Core Cooling A benefit by maintaining coverage of SG tubes thus reducing the release potential for induced SGTR given high pressure core melt sequence.Modify 10" Condensate Filter Flange to have a 21/2-inch female fire hose Possible enhancement of long 164 adapter with isolation valve. term core damage sequences Core Cooling A that credit CST makeup.0 CD-n, Cl)CD CD >>CD .> CD C 0 021 r- ,, 6. CD)CD W=0-CD 0 0 CD', (0 CD 7'Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Could enhance long term 165 RWST fill from firewater during containment injection

-Modify 6" RWST containment injection Core/Containmen A Flush Flange to have a 21/22-inch female fire hose adapter with isolation valve, sequences that would benefit t Cooling from RWST makeup.Could enhance long term 166 Fabricate attachment to fill the RWST via the Silica skid; mod would include containment injection Core/Containmen A a 2%-inch to 2-inch adapter. sequences that would benefit t Cooling from RWST makeup.Reduce CDF contribution from 167 Install independent seal injection pump (low volume pump) with automatic RCP seal LOCA events driven IE Freq A start. by seal cooling hardware failures.Reduce CDF contribution from 168 Install independent seal injection pump (low volume pump) with manual start. RCP seal LOCA events driven IE Freq A by seal cooling hardware failures.Reduce CDF contribution from RCP seal LOCA events driven 169 Install independent charging pump (high volume pump) with manual start by seal cooling hardware IE Freq A failures; improve decay heat removal using feed & bleed.Reduce CDF contribution from 170 Replace the Positive Displacement Pump (PDP) with a 3rd centrifugal RCP seal LOCA events driven IE Freq A charging pump. Consider low volume and cooling water independence, by seal cooling hardware failures.Complete.

High temperature 171 Install high temperature O-rings in RCPs. o-rings installed and credited IE Freq A in PRA as applicable.

Reduce CDF contribution from 172 Evaluate installation of a "shutdown seal" in the RCPs being developed by transients with seal cooling IE Freq A Westinghouse.

hardware failures resulting in RCP seal LOCA events.0 CD-n, Cn CD CD >CD "a> CD CD M Cjn r- Cln oCD CD0 CD 0 0 03 CD Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Complete.

RCS depressurization procedures complete and credited in PRA 173 Improve procedural guidance for directing depressurization of RCS. as applicable.

This reduces IE Freq A CDF contribution from RCP seal LOCA during SBO-type sequences.

Improve reliability of reactor scram by providing remote-174 Provide alternate scram button to remove power from MG sets to CR drives, manual capability to remove IE Freq A rod drive power should the reactor trip breakers fail;reduce ATWS contribution.

175 Install fire detection in turbine building relay room. Improve fire detection and Fire Risk A manual suppression actions.Complete.

Combustible 176 Install additional suppression at west wall of turbine building.

materials control improved Fire Risk A and credited in PRA as applicable.

Improve fire response procedure to indicate that PCCW can be impacted by Complete.

Addressed in Fire 177 Imp fire rvesns Protection Maintenance Fire Risk A PAB fire event. Manual.178 Improve fire response procedure to indicate important fire areas including Complete.

Addressed in Fire Fire Risk A control room, PCCW pump area and cable spreading room. Protection Manual.Possible reduction in CDF if mitigating fire-induced LOCA.Judged marginal benefit due to existing design and 179 Fire induced LOCA response procedure from Alternate Shutdown Panel. guidance to minimize potential Fire Risk A for inadvertent PORV interaction.

Thus, likelihood of LOCA with control room uninhabitable for a long period of time is judged low.03 CD-n Cl)CD CD >>CD o0 D 0CL CL X.CD CD W Z.0 CD)CD Xi CD CD CD 0)0:3 W'CD a)0-0 X', af)0 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Proper scupper openings 180 Modify SW pump house roof to allow scuppers to function properly.

provided to limit accumulation Other Ext A of precipitation on roof.Relay chatter fragility judged low contributor to CDF.Significant uncertainty in 181 Improve relay chatter fragility.

hazard and fragility not easily Other Ext A removed and beyond state-of-the-art as stated in IPEEE. No further actions needed.Improve component fragility 182 Improve seismic capacity of EDGs and steam-driven EFW pump. and reduce seismic event Other Ext A contribution to CDF.Reduce CDF impact as a result of postulated CW break 183 Turbine Building internal flooding improvements, resulting in loss of offsite Other Ext A power and loss of vital switchgear.

Purge path is large opening.Reduce exposure time of open 184 Control/reduce time that the containment purge valves are in open position.

path, improve Containment A reliability/availability of Cl, Phenomena A reduce Cl failure contribution to large release.Improvements to depressurization to reduce Containment 185 Improve procedural guidance for directing depressurization of RCS. potential for high pressure Phenomena A core melt ejection and DCH challenge.

Improve containment reliability 186 Install containment leakage monitoring system. by reducing the potential for Containment A pre-existing containment Phenomena leakage.0 CD C', CD CD >-0> CD 0. =0CD 0- I sCD r CDO CD'1-I1 3'CD CD 0)Cn-CD 0 0 CDW 0,-0 0, CD TI (0 01 Table F.5.6-1 List of SAMA Candidates (Continued)

Seabrook SAMA Number Potential Improvement Discussion Focus of SAMA Source (1)Reduce ISLOCA challenge to Containment 187 Install RHR isolation valve leakage monitoring system. RHR by identification of Phenomena A upstream valve failure.Containment flooding -Modify the containment ILRT10-inch test flange to Improve the time to align to Containment A 188 include a 5-inch adapter with isolation valve. Fire Protection system to flood Phenomena containment.

Allow all equipment to be run 189 Modify or analyze SEPS capability; 1 of 2 SEPS for LOSP non-SI loads, 2 of following LOSP with EDG Other A 2 for LOSP SI loads. failure but successful start and load of SEPS.Eliminate current requirement 190 Add synchronization capability to SEPS Diesel. for dead bus transfer from Other A SEPS to normal power.Potential for some 191 Remove the 135F temperature trip of the PCCW pumps. improvement in PCCW Other A reliability by eliminating consideration of spurious trip.Note 1: Source reference numbers are from NEI 05-01 (Reference 20)A -Plant-specific SAMA candidates based on review of IPE, IPEEE, presentation and solicitation of plant personnel and expert panel.CD CD CD >> CD 0 =-. X CD IDO CD,~

Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.6 PHASE I ANALYSIS A preliminary screening of the complete list of SAMA candidates was performed to limit the number of SAMAs for which detailed analysis in Phase II was necessary.

The screening criteria used in the Phase I analysis are described below." Screening Criterion A -Not Applicable:

If a SAMA candidate did not apply to the Seabrook Unit 1 plant design, it was not retained." Screening Criterion B -Already Implemented or Intent Met: If a SAMA candidate had already been implemented at the Seabrook Station or the intent of the candidate is met, it was not retained." Screening Criterion C -Combined:

If a SAMA candidate was similar in nature to and could be combined with another SAMA candidate to develop a more comprehensive or plant-specific SAMA candidate, only the combined SAMA candidate was retained." Screening Criterion D -Excessive Implementation Cost: If a SAMA required extensive changes that would obviously exceed the maximum benefit (Section F.4.5), even without an implementation cost estimate, it was not retained." Screening Criterion E -Very Low Benefit: If a SAMA from an industry document was related to a non-risk significant system for which change in reliability is known to have negligible impact on the risk profile, it was not retained. (No SAMAs were screened using this criterion.)

Table F.6-1 presents the list of Phase I SAMA candidates and provides the disposition of each candidate, and any applicable screening criterion.

Those candidates that were not screened out by these criteria are evaluated further in the Phase II analysis (Section F.7). One hundred-seventeen SAMAs were screened from the analysis during Phase I and 74 SAMAs passed into the next phase of the analysis.Seabrook Station Unit 1 License Renewal Application Page F-96 oCD CD Q CD 0)CD a 0 CD (0 40 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 2 Replace lead-acid batteries with Extended DC power availability during No Retain for Phase II.fuel cells, an SBO.13 Install an additional, buried off- site Reduced probability of loss of off-site No Retain for Phase I1.power source. power.14 Install a gas turbine generator.

Increased availability of on-site AC No Retain for Phase II.power.16 Improve uninterruptible power Increased availability of power supplies No Retain for Phase I1.supplies.

supporting front-line equipment.

20 Add a new backup source of Increased diesel generator availability.

No Note that supplemental diesel diesel cooling. (SEPS) is air cooled. Retain for Phase II.21 Develop procedures to repair or Increased probability of recovery from No Revisit as part of Phase II replace failed 4 KV breakers, failure of breakers that transfer 4.16 kV screening.

Trip test every 3 non-emergency buses from unit station years, inspections every 6 service transformers.

years, refurbish every 12 years. Each bus has two in feeds. Emergency buses have three in feeds. Spare breaker for ECCS. Fast transfer.24 Bury off-site power lines. Improved off-site power reliability during No Retain for Phase I1.severe weather.25 Install an independent active or Improved prevention of core melt No Retain for Phase II.passive high pressure injection sequences.

system.26 Provide an additional high Reduced frequency of core melt from No Retain for Phase II.pressure injection pump with small LOCA and SBO sequences.

independent diesel.28 Add a diverse low pressure Improved injection capability.

No Retain for Phase II.injection system.0)=)CD-n, CD CD>> CD o0.CL X CD M~0 CD CD CD 0 cn ;:

OCD CD 0 CD 0 0 CD M.0 0)0 CD CD CO Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 35 Throttle low pressure injection Extended reactor water storage tank No Retain for Phase II.pumps earlier in medium or large- capacity.break LOCAs to maintain reactor water storage tank inventory.

39 Replace two of the four electric Reduced common cause failure of the No Retain for Phase II.safety injection pumps with diesel- safety injection system. This SAMA was powered pumps. originally intended for the Westinghouse-CE System 80+, which has four trains of safety injection.

However, the intent of this SAMA is to provide diversity within the high- and low-pressure safety injections systems.41 Create a reactor coolant Allows low pressure emergency core No Retain for Phase II.depressurization system. cooling system injection in the event of small LOCA and high-pressure safety injection failure.43 Add redundant DC control power Increased availability of SW. No Retain for Phase II.for SW pumps.44 Replace ECCS pump motors with Elimination of ECCS dependency on No ECCS pump motors are air-cooled motors. component cooling system. currently air-cooled.

ECCS pumps require component cooling. Elimination of component cooling dependency is evaluated in Phase I1.55 Install an independent reactor Reduced frequency of core damage No Retain for Phase I1.coolant pump seal injection from loss of component cooling water, system, with dedicated diesel, service water, or station blackout.59 Install an additional component Reduced likelihood of loss of component No Currently have 2, 100%cooling water pump. cooling water leading to a reactor capacity pumps in each coolant pump seal LOCA. division of PCCW. Retain for Phase II.0)CD-n, Cl)CD CD >> CD o0.CD> CD CD CD 0 U) ;.

3'CD D00 0 CD~f CD Q'0> c--0 0)CD CD Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 65 Install a digital feed water Reduced chance of loss of main feed No Plant upgrade to incorporate upgrade. water following a plant trip. digital feedwater control system is in progress.77 Provide a passive, secondary-side Reduced potential for core damage due No Retain for Phase I1.heat-rejection loop consisting of a to loss-of-feedwater events.condenser and heat sink.80 Provide a redundant train or Increased availability of components No Except for RHR, charging, means of ventilation.

dependent on room cooling, and diesels there are proceduralized compensatory ventilation actions (open doors/dampers/fans).

Retain for Phase II evaluation.

90 Create a reactor cavity flooding Enhanced debris cool ability, reduced No Retain for Phase II.system. core concrete interaction, and increased fission product scrubbing.

91 Install a passive containment Improved containment spray capability.

No Retain for Phase II.spray system.93 Install an unfiltered, hardened Increased decay heat removal capability No Retain for Phase II.containment vent. for non-ATWS events, without scrubbing released fission products.94 Install a filtered containment vent Increased decay heat removal capability No Retain for Phase II.to remove decay heat. Option 1: for non-ATWS events, with scrubbing of Gravel Bed Filter; Option 2: released fission products.Multiple Venturi Scrubber 96 Provide post-accident containment Reduced likelihood of hydrogen and No Retain for Phase II.inserting capability, carbon monoxide gas combustion.

97 Create a large concrete crucible Increased cooling and containment of No Retain for Phase II.with heat removal potential to molten core debris. Molten core debris contain molten core debris, escaping from the vessel is contained within the crucible and a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.0)=)CD-ni CD CD >>0=0. X CD~0>CD CD CD 0 cn :ý.

I- C/)F CD CD M M0'CD 0 0;0X CD 0 0 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 98 Create a core melt source Increased cooling and containment of No Retain for Phase II.reduction system. molten core debris. Refractory material would be placed underneath the reactor vessel such that a molten core falling on the material would melt and combine with the material.

Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.99 Strengthen primary/secondary Reduced probability of containment No Retain for Phase II.containment (e.g., add ribbing to over-pressurization.

containment shell).100 Increase depth of the concrete Reduced probability of base mat melt- No Retain for Phase IL.base mat or use an alternate through.concrete material to ensure melt-through does not occur.101 Provide a reactor vessel exterior Increased potential to cool a molten core No Retain for Phase I1.cooling system. before it causes vessel failure, by submerging the lower head in water.102 Construct a building to be Reduced probability of containment No Retain for Phase II.connected to primary/secondary over-pressurization.

containment and maintained at a vacuum.106 Install automatic containment Extended time over which water remains No Retain for Phase II.spray pump header throttle valves, in the reactor water storage tank, when full containment spray flow is not needed.107 Install a redundant containment Increased containment heat removal No Retain for Phase II.spray system. ability.0,=r 3 CD-n W/CD CD >>CD o =~0. CL E X~0> CD~CD a CDO CD 0 I-CD CD XD CD 0)0 C,, CD a-0~0 0 Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 108 Install an independent power Reduced hydrogen detonation potential.

No Retain for Phase II.supply to the hydrogen control system using either new batteries, a non-safety grade portable generator, existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel.109 Install a passive hydrogen control Reduced hydrogen detonation potential.

No Retain for Phase II.system.110 Erect a barrier that would provide Reduced probability of containment No Retain for Phase I1.enhanced protection of the failure.containment walls (shell) from ejected core debris following a core melt scenario at high pressure.112 Add redundant and diverse limit Reduced frequency of containment No Retain for Phase II.switches to each containment isolation failure and ISLOCAs.isolation valve.113 Increase leak testing of valves in Reduced ISLOCA frequency.

No Retain for Phase II.ISLOCA paths.114 Install self-actuating containment Reduced frequency of isolation failure. No Retain for Phase II.isolation valves.115 Locate residual heat removal Reduced frequency of ISLOCA outside No Retain for Phase II.(RHR) inside containment containment.

119 Institute a maintenance practice to Reduced frequency of steam generator No All four steam generators are perform a 100% inspection of tube ruptures.

currently planned for steam generator tubes during inspection every other outage.each refueling outage. Foreign object search and retrieval is performed on generators that are open for inspection.

Retain for Phase II.0)0r 3 CD-n, CD CD >-V CD 'a> CD 0 0.0. X CD> CD CDO CD 0_0 CD 71 0ý 0 CD CD XD CD M, 0 U), CD 0)CY 0 0 0'D Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 121 Increase the pressure capacity of Eliminates release pathway to the No Retain for Phase I1.the secondary side so that a environment following a steam generator steam generator tube rupture tube rupture.would not cause the relief valves to lift.125 Route the discharge from the main Reduced consequences of a steam No Retain for Phase II.steam safety valves through a generator tube rupture.structure where a water spray would condense the steam and remove most of the fission products.126 Install a highly reliable (closed Reduced consequences of a steam No Retain for Phase II.loop) steam generator shell-side generator tube rupture.heat removal system that relies on natural circulation and stored water sources 129 Vent main steam safety valves in Reduced consequences of a steam No Retain for Phase II.containment, generator tube rupture.130 Add an independent boron Improved availability of boron injection No Currently have a boron injection system. during ATWS. injection system, but do not have one that is independent.

Review as part of Phase II screening.

131 Add a system of relief valves to Improved equipment availability after an No Retain for Phase I11 prevent equipment damage from ATWS.pressure spikes during an ATWS.133 Install an ATWS sized filtered Increased ability to remove reactor heat No Retain for Phase II.containment vent to remove decay from ATWS events.heat.147 Install digital large break LOCA Reduced probability of a large break No Retain for Phase II.protection system. LOCA (a leak before break).0 CD CO)CD CD >CD "> CD o M ax CD>CD CD 0 CDO a,-CD 71 0 N)

CD CD XD CD 0D 0)Cn CD M 0)0 0 0 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 153 Install secondary side guard pipes Prevents secondary side No Retain for Phase II.up to the main steam isolation depressurization should a steam line valves, break occur upstream of the main steam isolation valves. Also guards against or prevents consequential multiple steam generator tube ruptures following a main steam line break event.154 Modify SEPS design to Improve reliability of onsite power; No Retain for Phase II.accommodate: (a) automatic bus reduce SBO CDF contribution; remove loading, (b) automatic bus dependence on operator action.alignment.

156 Install alternate offsite power Improve offsite power reliability and No Retain for Phase II.source that bypasses the independence of switchyard and SF6 switchyard.

For example, use bus duct; allow restoration of offsite campus power source to energize power within a few hours.Bus E5 or E6.157 Provide independent AC power Reduce CDF of long term SBO No Retain for Phase II.source for battery chargers.

For sequences; extend battery life to allow example, provide portable additional time for recovery.generator to charge station battery.159 Install additional batteries.

Reduce CDF of long term SBO No Retain for Phase II.sequences; extend battery life to allow additional time for recovery.161 Modify EDG jacket heat exchanger Alternate cooling to both EDGs Would No Review as part of Phase II service water supply and return to reduce CDF long term sequences screening.

This SAMA allow timely alignment of alternate involving LOOP and loss of SW /cooling includes consideration of cooling water source (supply & tower. A loss of service water / cooling SAMA 19.drain) from firewater, RMW, DW, tower with a LOOP could result in EDG etc. failure and non-recovery.

0)CD-n, W, CD CD >-V CD '> CD 0CL CD r> CD CDO (n ;: cc CD 6OCD CD o)CD 0 0 CD W CDO CD 0 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 162 Increase the capacity margin of Extend long term operation of EFW No Review as part of Phase II the CST. without operator action for CST makeup screening.

This SAMA for sequences that do not go to cold includes consideration of shutdown.

Enhance CST margin for SAMA 71.design-basis seismic event with cooldown via SG and transition to RHR.163 Install third EFW pump (steam- Reduce CDF of SBO sequences by No Retain for Phase II.driven), improving overall reliability of EFW system independent of AC power. An additional pump might also have a Level 2 benefit by maintaining coverage of SG tubes thus reducing the release potential for induced SGTR given high pressure core melt sequence.164 Modify 10" Condensate Filter Possible enhancement of long term core No Retain for Phase I1.Flange to have a 2%-inch female damage sequences that credit CST fire hose adapter with isolation makeup.valve.165 RWST fill from firewater during Could enhance long term containment No Retain for Phase I1.containment injection

-Modify 6" injection sequences that would benefit RWST Flush Flange to have a 2Y- from RWST makeup.inch female fire hose adapter with isolation valve.167 Install independent seal injection Reduce CDF contribution from RCP seal No Retain for Phase II.pump (low volume pump) with LOCA events driven by seal cooling automatic start, hardware failures.168 Install independent seal injection Reduce CDF contribution from RCP seal No Retain for Phase I1.pump (low volume pump) with LOCA events driven by seal cooling manual start. hardware failures.169 Install independent charging pump Reduce CDF contribution from RCP seal No Retain for Phase II.(high volume pump) with manual LOCA events driven by seal cooling start hardware failures; improve decay heat removal using feed & bleed.0 CD'1 CD CD >CD> CD o =CL X CD M rn>CD-CDW CDO r- cn FVCD CD M CD 0 0 CD C/)M -(0 CD 7'0)01 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 170 Replace the Positive Displacement Reduce CDF contribution from RCP seal No Currently have to Pump (PDP) with a 3rd centrifugal LOCA events driven by seal cooling administrative control PDP.charging pump. Consider low hardware failures.

Used in emergencies (as a volume and cooling water back-up).independence.

Retain for Phase II.172 Evaluate installation of a Reduce CDF contribution from transients No RCP shutdown seal not yet"shutdown seal" in the RCPs being with seal cooling hardware failures available.

developed by Westinghouse.

resulting in RCP seal LOCA events.174 Provide alternate scram button to Improve reliability of reactor scram by No Retain for Phase II. This remove power from MG sets to CR providing remote-manual capability to SAMA considers assessment drives, remove rod drive power should the of SAMA 136.reactor trip breakers fail; reduce ATWS contribution.

175 Install fire detection in turbine Improve fire detection and manual No Retain for Phase II.building relay room. suppression actions.179 Fire induced LOCA response Possible reduction in CDF if mitigating No Addressed in App. R (limit).procedure from Alternate fire-induced LOCA. Judged marginal Would not increase the risk Shutdown Panel. benefit due to existing design and probability.

guidance to minimize potential for inadvertent PORV interaction.

Thus, Retain for Phase II.likelihood of LOCA with control room uninhabitable for a long period of time is judged low.181 Improve relay chatter fragility.

Relay chatter fragility judged low No Low contributor.

Retain for contributor to CDF. Significant Phase I1.uncertainty in hazard and fragility not easily removed and beyond state-of-the-art as stated in IPEEE. No further actions needed.182 Improve seismic capacity of EDGs Improve component fragility and reduce No Retain for Phase I1.and steam-driven EFW pump. seismic event contribution to CDF.0 CD-n C', CE)CD >CE)>CDv>0M 0. xL-CD CDO CD 0 F CD CD 0 0 CD 0)>C: 0 0)Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 184 Control/reduce time that the Purge path is large opening. Reduce No Retain for Phase II.containment purge valves are in exposure time of open path, improve open position.

reliability/availability of Cl, reduce Cl failure contribution to large release.186 Install containment leakage Improve containment reliability by No Retain for Phase II.monitoring system. reducing the potential for pre-existing containment leakage.187 Install RHR isolation valve leakage Reduce ISLOCA challenge to RHRby No Retain for Phase II.monitoring system. identification of upstream valve failure.189 Modify or analyze SEPS Allow all equipment to be run following No Retain for Phase I1.capability; 1 of 2 SEPS for LOSP LOSP with EDG failure but successful non-SI loads, 2 of 2 for LOSP SI start and load of SEPS.loads.190 Add synchronization capability to Eliminate current requirement for dead No Retain for Phase II.SEPS Diesel. bus transfer from SEPS to normal power.8 Increase training on response to Improved chances of successful Yes A -Not Loss of any one 120 V Vital loss of two 120V AC buses which response to loss of two 120V AC buses. Applicable bus will result in plant trip.causes inadvertent actuation AOPs exist for loss of power signals. supplies.12 Create AC power cross-tie Increased availability of on-site AC Yes A -Not Single unit site.capability with other unit (multi-unit power. Applicable site).15 Install tornado protection on gas Increased availability of on-site AC Yes A -Not No gas turbine.turbine generator.

power. Applicable 27 Revise procedure to allow Extended HPCI and RCIC operation.

Yes A -Not BWR Item.operators to inhibit automatic Applicable vessel depressurization in non-ATWS scenarios.

CD CD CD >CD -a> CD o0~CL X~0>CD CD a)-ý CD CD 0 3'CD CD 0)CT0 CD 0 0 CD Cl CDD> C: '0-a_0-4 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 34 Provide an in-containment reactor Continuous source of water to the safety Yes A -Not Item for new construction plant water storage tank. injection pumps during a LOCA event, Applicable only.since water released from a breach of the primary system collects in the in-containment reactor water storage tank, and thereby eliminates the need to realign the safety injection pumps for long-term post-LOCA recirculation.

38 Change the in-containment reactor Reduced common mode failure of Yes A -Not Advanced reactor item.water storage tank suction from injection paths. Applicable four check valves to two check and two air-operated valves.63 Use fire prevention system pumps Reduced frequency of reactor coolant Yes A -Not Discharge pressure is too low.as a backup seal injection and pump seal LOCA. Applicable high pressure makeup source.69 Install manual isolation valves Reduced dual turbine-driven pump Yes A -Not Not a dual turbine design.around auxiliary feedwater turbine- maintenance unavailability.

Applicable driven steam admission valves.82 Stage backup fans in switchgear Increased availability of ventilation in the Yes A -Not There is no requirement for rooms. event of a loss of switchgear ventilation.

Applicable backup fans. Compensatory ventilation procedures are used to ensure adequate ventilation.

84 Create ability to switch emergency Continued fan operation in a station Yes A -Not EFW turbine driven pump is feedwater room fan power supply blackout.

Applicable self-cooled and remains to station batteries in a station functional during SBO blackout.

conditions.

Compensatory ventilation procedures are used during SBO to ensure adequate ventilation.

85 Provide cross-unit connection of Increased ability to vent containment Yes A -Not No second unit.uninterruptible compressed air using the hardened vent. Applicable supply.0 CD-n, C/)CD CD >CD> CD o0. C E. X CD~0>CD~CDW CDO oCD CD 0 0 CDO 0 (D)CD OD Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 95 Enhance fire protection system Improved fission product scrubbing in Yes A -Not BWR item.and standby gas treatment system severe accidents.

Applicable hardware and procedures.

105 Delay containment spray actuation Extended reactor water storage tank Yes A -Not A delay of containment spray after a large LOCA. availability.

Applicable would violate Seabrook's licensing basis. Therefore, this generic SAMA not pursued and is screened in Phase 1.134 Revise procedure to bypass MSIV Affords operators more time to perform Yes A -Not BWR item.isolation in turbine trip ATWS actions. Discharge of a substantial Applicable scenarios, fraction of steam to the main condenser (i.e., as opposed to into the primary containment) affords the operator more time to perform actions (e.g., SLC injection, lower water level, depressurize RPV) than if the main condenser was unavailable, resulting in lower human error probabilities.

135 Revise procedure to allow override Allows immediate control of low pressure Yes A -Not BWR item.of low pressure core injection core injection.

On failure of high Applicable during an ATWS event, pressure core injection and condensate, some plants direct reactor depressurization followed by five minutes of automatic low pressure core injection.

141 Provide additional restraints for Increased availability of fire protection Yes A -Not Currently have no C02 C02 tanks, given a seismic event. Applicable systems. Halon systems are used and are installed to industry codes and standards.

All Halon systems are located in non-safety related areas (e.g., main plant computer room).CD-n, C,)CD CD >CD> CD o0. C E~ X CD> CD CDO CD 0 O)*CD CD W CD 0 0 CDC CDO 0-0 CD (0 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 142 Replace mercury switches in fire Decreased probability of spurious fire Yes A -Not Currently do not have any protection system. suppression system actuation.

Applicable mercury switches in the fire protection system.143 Upgrade fire compartment Decreased consequences of a fire. Yes A -Not Seabrook plant design barriers.

Applicable includes 3-hour rated fire barriers.191 Remove the 135F temperature trip Potential for some improvement in Yes A -Not Removal of the PCCW high of the PCCW pumps. PCCW reliability by eliminating Applicable temperature trip would violate consideration of spurious trip. the current licensing basis for the plant.3 Add additional battery charger or Improved availability of DC power Yes B -Intent Each vital DC battery division portable, diesel-driven battery system. Met has a spare (portable) battery charger to existing DC system. charger that can be connected in place of a main battery charger.Refer to SAMA 157 for evaluation of portable battery charger.4 Improve DC bus load shedding.

Extended DC power availability during Yes B -Intent Load shedding is an SBO. Met proceduralized.

6 Provide additional DC power to the Increased availability of the 120 V vital Yes B -Intent Intent met due to the 120/240V vital AC system. AC bus. Met configuration of the existing station vital battery divisions.

Each division has two batteries, A/C and B/D.7 Add an automatic feature to Increased availability of the 120 V vital Yes B -Intent 120 V Inverters have AC and transfer the 120V vital AC bus AC bus. Met DC inputs, which provide from normal to standby power. uninterrupted power to the associated vital buses.9 Provide an additional diesel Increased availability of on-site Yes B -Intent Currently have 2 safety related generator.

emergency AC power. Met diesels (EDGs) and 1 supplemental diesel (SEPS)that can be tied to either train.0)CD'1 CD CD >-0 CD -> CD)0.-3 CD 0 CD-0 CD 0 wn P, 3'CD CD a)= 0" CD 0 0 CDW 02'0 02 CD CD, Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 10 Revise procedure to allow bypass Extended diesel generator operation.

Yes B -Intent Non-essential trips bypassed of diesel generator trips. Met during emergency starts.11 Improve 4.16-kV bus cross-tie Increased availability of on-site AC Yes B -Intent Currently have two AC ability, power. Met divisions, each with an emergency diesel generator.

In addition a backup swing diesel, is available and can supply power to either electrical division.17 Create a cross-tie for diesel fuel oil Increased diesel generator availability.

Yes B -Intent Currently able to cross-tie (multi-unit site). Met diesel storage tanks, but not from Unit 2 storage tanks.18 Develop procedures for Increased diesel generator availability.

Yes B -Intent Currently have 7 days of replenishing diesel fuel oil. Met supply at full load. Sufficient time to order and replenish.

22 In training, emphasize steps in Reduced human error probability during Yes B -Intent Included in operator training.recovery of off-site power after an off-site power recovery.

Met SBO.23 Develop a severe weather Improved off-site power recovery Yes B -Intent Procedures for station severe conditions procedure.

following external weather-related Met weather conditions exist.events.29 Provide capability for alternate Improved injection capability.

Yes B -Intent Implemented through alternate injection via diesel-driven fire Met mitigation strategy.pump.30 Improve ECCS suction strainers.

Enhanced reliability of ECCS suction. Yes B -Intent New and improved strainers Met installed.

31 Add the ability to manually align Enhanced reliability of ECCS suction. Yes B -Intent Suction valves open emergency core cooling system Met automatically and the pumps recirculation.

have to be aligned manually (w/time restraints).

02 CD-n Ci)CD CD >-V CD v> CD Crn (0 CD-CD0<V;:

C-CD CD'0 0)CD 0)0 0 0 C Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 32 Add the ability to automatically Enhanced reliability of ECCS suction. Yes B -Intent Suction valves open align emergency core cooling Met automatically and the pumps system to recirculation mode upon have to be aligned manually refueling water storage tank (w/time restraints).

depletion.

33 Provide hardware and procedure Extended reactor water storage tank Yes B -Intent Implemented through SAMG to refill the reactor water storage capacity in the event of a steam Met and alternate mitigation tank once it reaches a specified generator tube rupture (or other LOCAs strategy.low level, challenging RWST capacity).

36 Emphasize timely recirculation Reduced human error probability Yes B -Intent Suction valves open alignment in operator training, associated with recirculation failure. Met automatically and the pumps have to be aligned manually (with time restraints).

Training and procedures include timing requirements.

37 Upgrade the chemical and volume For a plant like the Westinghouse Yes B -Intent Charging pumps are the high control system to mitigate small AP600, where the chemical and volume Met head safety injection pumps.LOCAs. control system cannot mitigate a small LOCA, an upgrade would decrease the frequency of core damage.40 Provide capability for remote, Improved chance of successful Yes B -Intent Local and remote capability is manual operation of secondary operation during station blackout events Met provided and is identified in side pilot-operated relief valves in in which high area temperatures may be plant procedures.

a station blackout, encountered (no ventilation to main steam areas).42 Make procedure changes for Allows low pressure emergency core Yes B -Intent Current EOPs provide reactor coolant system cooling system injection in the event of Met guidance for RCS depressurization.

small LOCA and high-pressure safety depressurization.

injection failure.45 Enhance procedural guidance for Reduced frequency of loss of Yes B -Intent PCCW procedures currently use of cross-tied component component cooling water and service Met provide a maintenance cross-cooling or service water pumps. water. tie capability.

0 CD-n CD CD >> CD oL a CD (0>CD-CD CD 0 cn ;:.CD 71 C-CD W CD CD 03 U/)CD a)0 0 Ul)Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 46 Add a service water pump. Increased availability of cooling water. Yes B -Intent Currently have 2 trains, with 3 Met pumps per train (2 ocean water cooling pumps and 1 cooling tower).47 Enhance the screen wash system. Reduced potential for loss of SW due to Yes B -Intent SBK currently has two clogging of screens. Met separate heat sinks. Ocean SW (two divisions) and the Cooling Tower SW system (two divisions).

The Ocean SW divisions are equipped with suction bay screens and screen wash systems. The Cooling Tower SW divisions are independent of Ocean SW and do not require screens/screen wash.48 Cap downstream piping of Reduced frequency of loss of Yes B -Intent PCCW drawings show vents normally closed component component cooling water initiating Met and drains to be capped. Also cooling water drain and vent events, some of which can be attributed procedure OS-1012.01, PCCW valves, to catastrophic failure of one of the many Fill and Vent, refers to single isolation valves. uncapping and capping of vent and drain valves.49 Enhance loss of component Reduced potential for reactor coolant Yes B -Intent Included in plant procedure.

cooling water (or loss of service pump seal damage due to pump bearing Met water) procedures to facilitate failure.stopping the reactor coolant pumps.50 Enhance loss of component Reduced probability of reactor coolant Yes B -Intent Included in procedure.

cooling water procedure to pump seal failure. Met underscore the desirability of cooling down the reactor coolant system prior to seal LOCA.51 Additional training on loss of Improved success of operator actions Yes B -Intent Loss of CCW is included in the component cooling water, after a loss of component cooling water. Met operator training program.03 CD-n C,)CD CD >CD -> CD o a3 E x (0 03 CD-CD (n ;.,-D CD 71 i"3 CD CD X CD CD a)0 U): CD 0)0r 0 0 X,, U)C: Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 52 Provide hardware connections to Reduced effect of loss of component Yes B -Intent Currently have two alternate allow another essential raw cooling water by providing a means to Met cooling methods for charging cooling water system to cool maintain the charging pump seal pump cooling. These methods charging pump seals. injection following a loss of normal include cooling from Fire cooling water. Water or Demineralized Water.53 On loss of essential raw cooling Increased time before loss of component Yes B -Intent PCCW Abnormal Procedure water, proceduralize shedding cooling water (and reactor coolant pump Met OS1212.01 provides guidance component cooling water loads to seal failure) during loss of essential raw actions depending on the extend the component cooling cooling water sequences.

abnormal condition.

Guidance water heat-up time. exists for isolating CVCS letdown, transferring charging pump cooling to alternate cooling, and tripping of RCPs.The procedure includes monitoring of equipment cooled by PCCW.54 Increase charging pump lube oil Increased time before charging pump Yes B -Intent The charging pump lube oil capacity, failure due to lube oil overheating in loss Met coolers at Seabrook Station of cooling water sequences.

have alternate cooling capability manually aligned from Demineralized Water system or from the Fire Water system.57 Use existing hydro test pump for Reduced frequency of core damage Yes B -Intent EOPs provide guidance to reactor coolant pump seal from loss of component cooling water or Met align PDP for RCP seal injection, service water, but not a station blackout, injection.

Use of the PDP unless an alternate power source is should not degrade seal used. integrity in the short term.0)C)CD'1 Cl)CD CD >CDv> (D 0~CD CD mD<V CDO-0 CD CD 71 0 3*CD CD 0 a 0 CDC: 00)0 CD Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 60 Prevent makeup pump flow Reduced frequency of loss of reactor Yes B -Intent There are no relief valves on diversion through the relief valves, coolant pump seal cooling if spurious Met the "supply" side of seal high pressure injection relief valve injection (only on return side).opening creates a flow diversion large In addition, there are no relief enough to prevent reactor coolant pump valves in high pressure seal injection.

injection or charging system piping that would create a potential for flow diversion of seal injection.

61 Change procedures to isolate Reduced frequency of core damage due Yes B -Intent Operator guidance is provided reactor coolant pump seal return to loss of seal cooling. Met in existing plant procedures.

flow on loss of component cooling water, and provide (or enhance)guidance on loss of injection during seal LOCA.62 Implement procedures to stagger Extended high pressure injection prior to Yes B -Intent At Seabrook, the charging high pressure safety injection overheating following a loss of service Met pumps provide the high pump use after a loss of service water. pressure safety injection water. function.

The charging pumps are cooled by PCCW, which is in-turn cooled by SW. Should SW or PCC fail, alternate cooling alignment to the charging pumps is available via hard piped connection from DM water and/or fire protection.

Procedural guidance is provided for the realignment.

0 CD-n CD CD >~'0>CD>CD o0.>CD CD W Z.0>CD0&n CD 5OCD CD 0)CD CI)~0'0 CD 71 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 64 Implement procedure and Improved ability to cool residual heat Yes B -Intent The PCCW system is hardware modifications to allow removal heat exchangers.

Met designed with a header cross-manual alignment of the fire water tie between divisions A and B.system to the component cooling Although the primary function water system, or install a of the cross-tie is to support a component cooling water header maintenance activity, it is cross-tie.

recognized that the cross-tie could be aligned to provide a plant heat sink in the unlikely event that only one SW train is available at the same time that only the opposite division PCCW is available.

66 Create ability for emergency Increased availability of feedwater.

Yes B -Intent Included in SAMG and connection of existing or new Met alternate mitigation strategies.

water sources to feedwater and condensate systems.67 Install an independent diesel for Extended inventory in CST during an Yes B -Intent Included in SAMG and the condensate storage tank SBO. Met alternate mitigation strategies.

makeup pumps.68 Add a motor-driven feedwater Increased availability of feedwater.

Yes B -Intent Currently have two steam pump. Met driven main feedwater pumps and one motor-driven startup feedwater pump, powered from Emergency Bus 5 or non-emergency bus 4. EFW consists of one steam driven pump and one motor-driven pump powered from Emergency Bus 6.70 Install accumulators for turbine- Eliminates the need for local manual Yes B -Intent Flow control valves are all AC driven auxiliary feedwater pump action to align nitrogen bottles for control Met MOVs (aligned as open).flow control valves, air following a loss of off-site power.CD UI)CD CD >> CD K 0.CD~0-CD 2!0 (DO Cj)0 C-CD CD CD CD 0 (n, CD 0)0 0 X,, Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 72 Modify the turbine-driven auxiliary Improved success probability during a Yes B -Intent EFW turbine driven pump is feedwater pump to be self-cooled, station blackout.

Met self-cooled and remains functional during SBO conditions.

Compensatory ventilation procedures are used during SBO to ensure adequate ventilation.

73 Proceduralize local manual Extended auxiliary feedwater availability Yes B -Intent Included in SAMG and operation of auxiliary feedwater during a station blackout.

Also provides Met alternate mitigation strategies.

system when control power is lost. a success path should auxiliary feedwater control power be lost in non-station blackout sequences.

74 Provide hookup for portable Extended auxiliary feedwater availability.

Yes B -Intent Intent met through alternate generators to power the turbine- Met mitigation strategy for use of driven auxiliary feedwater pump fire water to feed SGs.after station batteries are depleted.75 Use fire water system as a backup Increased availability of steam generator Yes B -Intent Steam generator emergency for steam generator inventory, water supply. Met feed from fire water system available from fire pumps via plant procedures.

76 Change failure position of Allows greater inventory for the auxiliary Yes B -Intent Valve fails closed.condenser makeup valve if the feedwater pumps by preventing Met condenser makeup valve fails condensate storage tank flow diversion open on loss of air or power. to the condenser.

78 Modify the startup feedwater pump Increased reliability of decay heat Yes B -Intent Start-up feedwater pump fills so that it can be used as a backup removal. Met this function.

The startup to the emergency feedwater feedwater pump is normally system, including during a station powered from Emergency Bus blackout scenario.

5. The EFW steam-driven feedwater pump provided feedwater during SBO conditions.

03 CD-n, CD CD >CDv> CD o =~CL X CD M 0-> CD~CDW CDO c, 0) 0 5 CD CD M CD 0 0 CDc CD 0 0)0)CD 7'-.1 Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 79 Replace existing pilot-operated Increased probability of successful feed Yes B -Intent The current Seabrook design relief valves with larger ones, such and bleed. Met meets the intent of this SAMA.that only one is required for Seabrook has two PORVs successful feed and bleed. consistent with other PWR designs. In current PRA, the feed and bleed decay heat removal success criteria-applies the following combinations of PORVs and injection pumps: 1-of-2 PORVs with 1-of-2 charging pumps (high head SI)with eventual containment long term recirc.2-of-2 PORVs with 1-of-2 SI pumps (intermediate head SI)with eventual containment long term recirc.Loss of feedwater sequences contribute about 29% to the internal events CDF.81 Add a diesel building high Improved diagnosis of a loss of diesel Yes B -Intent High temperature alarm is temperature alarm or redundant building HVAC. Met currently provided in each louver and thermostat.

diesel room.83 Add a switchgear room high Improved diagnosis of a loss of Yes B -Intent High temperature alarm is temperature alarm. switchgear HVAC. Met currently provided in each essential switchgear room.86 Modify procedure to provide ability Increased availability of instrument air Yes B -Intent Air compressors powered from to align diesel power to more air after a LOOP. Met diesel-backed emergency compressors.

buses. In addition, Seabrook design includes a diesel-powered air compressor if needed.0)CD-n, C,, CD CD >CDv> CD~0> CD-CDW CDO I--cI OCD CD Q)*=- Cr n-1 C,-n CD 0 0 CDCI (D 0 cc CD OD Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 87 Replace service and instrument air Elimination of instrument air system Yes B -Intent Air compressors have been compressors with more reliable dependence on service water cooling. Met updated to be centrifugals.

compressors which have self-contained air cooling by shaft driven fans.88 Install nitrogen bottles as backup Extended SRV operation time. Yes B -Intent ASDVs have nitrogen bottle gas supply for safety relief valves. Met backup. PORVs are electrically operated and their design does not rely on a pneumatic supply.89 Improve SRV and MSIV Improved availability of SRVs and Yes B -Intent Currently have no issues with pneumatic components.

MSIVs. Met component performance (currently the MSIVs are replaced every 6 years).92 Use the fire water system as a Improved containment spray capability.

Yes B -Intent Seabrook has a relatively large backup source for the containment Met containment and as a result, spray system. the containment spray function is not important early.103 Institute simulator training for Improved arrest of core melt progress Yes B -Intent Classroom training is provided severe accident scenarios, and prevention of containment failure. Met on severe accident management guidelines.

Plant simulator used for accident scenario support during emergency plan training.104 Improve leak detection Increased piping surveillance to identify Yes B -Intent Current leak detection procedures.

leaks prior to complete failure. Improved Met capability is continuous leak detection would reduce LOCA monitoring.

Alarms provided frequency.

for identified and unidentified leak rates.111 Install additional pressure or leak Reduced ISLOCA frequency.

Yes B -Intent Current RCS leak detection monitoring instruments for Met capability is continuous detection of ISLOCAs. monitoring.

Alarms provided for identified and unidentified leak rates.0 3 CD-n C'CD CD>CD - oL X CD> CD CDO C._<.Z .

CD CD CD CD 0 Wi: CD a)07 0 0 X,)0)C: Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 116 Ensure ISLOCA releases are Scrubbed ISLOCA releases.

Yes B -Intent The only ISLOCA path of scrubbed.

One method is to plug Met concern is into the RHR drains in potential break areas so equipment vaults. For these that break point will be covered ISLOCA scenarios the RHR with water. equipment vaults flood and provides scrubbing of potential releases.117 Revise EOPs to improve ISLOCA Increased likelihood that LOCAs outside Yes B -Intent Guidance in EOPs.identification.

containment are identified as such. A Met plant had a scenario in which an RHR ISLOCA could direct initial leakage back to the pressurizer relief tank, giving indication that the LOCA was inside containment.

118 Improve operator training on Decreased ISLOCA consequences.

Yes B -Intent Included in EOP procedures ISLOCA coping. Met and operator training program.120 Replace steam generators with a Reduced frequency of steam generator Yes B -Intent Currently have less than 1% of new design. tube ruptures.

Met tubes plugged and good steam generator performance.

122 Install a redundant spray system Enhanced depressurization capabilities Yes B -Intent There are currently three to depressurize the primary during steam generator tube rupture. Met methods to perform system during a steam generator depressurization including use tube rupture. of PORVs, Pressurizer Spray, or Pressurizer Auxiliary Spray.123 Proceduralize use of pressurizer Backup method to using pressurizer Yes B,- Intent Existing process to vent valves during steam sprays to reduce primary system Met depressurize via PORVs, but generator tube rupture sequences.

pressure following a steam generator backup is use of sprays and tube rupture. aux sprays.There are currently three methods to perform depressurization including use of PORVs, Pressurizer Spray, or Pressurizer Auxiliary Spray.0)CD CD CD >CDv> CD CD>CD ,-CD CD 0 0)tto ,-D'.1 CD Cd, CD XD CD D 0)Cl, CD CU 0 0 0 C: Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 124 Provide improved instrumentation Improved mitigation of steam generator Yes B -Intent Steam lines are equipped with to detect steam generator tube tube ruptures.

Met radiation monitors.ruptures, such as Nitrogen-16 monitors.127 Revise emergency operating Reduced consequences of a steam Yes B -Intent Faulted SG refers to steam procedures to direct isolation of a generator tube rupture. Met line break faulted steam generator.

Ruptured SG refers to SG tube rupture 128 Direct steam generator flooding Improved scrubbing of steam generator Yes B -Intent EOPs direct maintaining level after a steam generator tube tube rupture releases.

Met in a ruptured steam generator.

rupture, prior to core damage.132 Provide an additional control Improved redundancy and reduced Yes B -Intent Currently have AMSAC.system for rod insertion (e.g., ATWS frequency.

Met AMSAC).138 Improve inspection of rubber Reduced frequency of internal flooding Yes B -Intent Circulating Water inlet/outlet expansion joints on main due to failure of circulating water system Met expansion joints in the Turbine condenser, expansion joints. Building are internally inspected each refueling outage when the condenser is opened for maintenance.

Also, the exterior of the Turbine Building CW expansion joints (and others)is inspected semi-annually during plant walkdowns.

144 Install additional transfer and Reduced number of spurious actuations Yes B -Intent Transfer switches installed at isolation switches.

during a fire. Met Remote Shutdown Panel.145 Enhance fire brigade awareness.

Decreased consequences of a fire. Yes B -Intent Captured in Met operator/personnel requals (for fire brigade) -combination of fight fire and preserve water.146 Enhance control of combustibles Decreased fire frequency and Yes B -Intent Currently contained in the Fire and ignition sources. consequences.

Met Protection Manual.0 CD U/)CD CD >CD> CD o0.CD-I L- CD CDO Cn.O CD ,-r 0 F2 0 0 CD:3 CD)0)> c Table F.6-1 Seabrook Station Phase I SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 148 Enhance procedures to mitigate Reduced consequences of a large break Yes B -Intent EOPs currently meet WOG large break LOCA. LOCA. Met recommendations.

149 Install computer aided Improved prevention of core melt Yes B -Intent Currently have a Safety instrumentation system to assist sequences by making operator actions Met Parameter Display System the operator in assessing post- more reliable. (SDS).accident plant status.150 Improve maintenance procedures.

Improved prevention of core melt Yes B -Intent Procedures exist and reflect sequences by increasing reliability of Met industry standards and important equipment.

practices.

151 Increase training and operating Improved likelihood of success of Yes B -Intent Time Critical Action (TCA)experience feedback to improve operator actions taken in response to Met Policy provides the training operator response.

abnormal conditions, requirements and feedback process for improving operator response.152 Develop procedures for Reduced consequences of Yes B -Intent The Seabrook UFSAR and transportation and nearby facility transportation and nearby facility Met IPEEE do not identify any plant accidents, accidents.

vulnerability from transportation or nearby facility accidents.

In addition, Seabrook Station performs a periodic review and assessment (every 3 years) of off-site chemical hazards associated with transportation and nearby facilities.

155 Install alternate emergency AC SEPS DG installed and credited in PRA Yes B -Intent SEPS diesel generator power source (e.g., swing diesel). to power Bus E5 or Bus E6. Met installed and incorporated into plant procedures.

=r CD-n, CD CD >CD> CD o0.CL X-0> CD-CD<D0 (n P CD',N)

I-" CD CD CD CD a)0 U)CD 0~0 0 C: Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 158 Provide enhanced procedural Reduce CDF of long term SBO Yes B -Intent Enhancement complete.direction for cross-tie of batteries sequences; extend battery life to allow Met Procedures exist to delineate within each train, additional time for recovery, the necessary steps for connecting each DC bus to its alternate (cross-tie) battery supply. This SAMA includes consideration of SAMA 1 and 5.160 Enhancements to address loss of SF6 enhancements improve offsite Yes B -Intent Complete.

SF6 enhancements SF6-type sequences.

power reliability.

Met are credited in PRA as applicable.

171 Install high temperature O-rings in Complete.

High temperature o-rings Yes B -Intent Complete.

High temp O-rings RCPs. installed and credited in PRA as Met are installed.

applicable.

173 Improve procedural guidance for Complete.

RCS depressurization Yes B -Intent Complete.directing depressurization of RCS. procedures complete and credited in Met PRA as applicable.

This reduces CDF contribution from RCP seal LOCA during SBO-type sequences.

176 Install additional suppression at Complete.

Combustible materials control Yes B -Intent Complete.

Controlling west wall of turbine building.

improved and credited in PRA as Met combustibles in the area via applicable, the Fire Protection Manual.177 Improve fire response procedure Complete.

Addressed in Fire Protection Yes B -Intent Complete.

Addressed in Fire to indicate that PCCW can be Maintenance Manual. Met Protection Maintenance impacted by PAB fire event. Manual.178 Improve fire response procedure Complete.

Addressed in Fire Protection Yes B -Intent Complete.

Addressed in Fire to indicate important fire areas Manual. Met Protection Maintenance including control room, PCCW Manual.pump area and cable spreading room.180 Modify SW pump house roof to Proper scupper openings provided to Yes B -Intent Enhancement complete, allow scuppers to function limit accumulation of precipitation on Met scuppers installed.

properly, roof.0 3 O0 CDCD CD >CD> CD 0 CL CD r K rn (0>CD CD Q CDO CD 0 CD T1 CDO CD 0)CD 0 0 CDc/CDD*0)03 0)CD Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 183 Turbine Building internal flooding Reduce CDF impact as a result of Yes B -Intent Turbine building flood improvements, postulated CW break resulting in loss of Met improvements have been offsite power and loss of vital implemented.

switchgear.

185 Improve procedural guidance for Improvements to depressurization to Yes B -Intent Complete.

RCS directing depressurization of RCS. reduce potential for high pressure core Met depressurization methods are melt ejection and DCH challenge.

proceduralized.

188 Containment flooding -Modify the Improve the time to align to Fire Yes B -Intent Flange and procedures exist.containment ILRT10-inch test Protection system to flood containment.

Met flange to include a 5-inch adapter with isolation valve.1 Provide additional DC battery Extended DC power availability during Yes C -Combined with SAMA 158.capacity.

an SBO. Combined 5 Provide DC bus cross-ties.

Improved availability of DC power Yes C -Combined with SAMA 158.system. Combined 19 Use fire water system as a backup Increased diesel generator availability.

Yes C -Combine with SAMA 161.source for diesel cooling. Combined 56 Install an independent reactor Reduced frequency of core damage No C -Combine with SAMA 167 and coolant pump seal injection from loss of component cooling water or Combined 168.system, without dedicated diesel, service water, but not a station blackout.58 Install improved reactor coolant Reduced likelihood of reactor coolant Yes C -Combine with SAMA 172.pump seals. pump seal LOCA. Combined 71 Install a new condensate storage Increased availability of the auxiliary Yes C -Combine with SAMA 162.tank (auxiliary feedwater storage feedwater system. Combined tank).136 Install motor generator set trip Reduced frequency of core damage due Yes C -Combine with SAMA 174.breakers in control room. to an ATWS. Combined 137 Provide capability to remove Decreased time required to insert control Yes C -Combine with SAMA 174.power from the bus powering the rods if the reactor trip breakers fail Combined control rods. (during a loss of feedwater ATWS which has rapid pressure excursion).

CD CD CD)CD>CD>>CD>0 C- X CD>0> ~CD CDO CD -

3 CD CD 0)CD 0 0 CD, 0>CD~0 CD CD-n Table F.6-1 Seabrook Station Phase 1 SAMA Analysis (Continued)

Seabrook Screened SAMA Out Screening Number Potential Improvement Discussion Phase 1? Criterion Phase I Disposition 139 Modify swing direction of doors Prevents flood propagation.

Yes C -Swing direction of TB door to separating turbine building Combined essential switchgear room not basement from areas containing an issue. Plant specific safeguards equipment.

flooding items are addressed in the plant specific SAMA 183.140 Increase seismic ruggedness of Increased availability of necessary plant Yes C -Refer to plant specific seismic plant components.

equipment during and after seismic Combined SAMAs 181 and 182.events.166 Fabricate attachment to fill the Could enhance long term containment Yes C -Combine with SAMA 165.RWST via the Silica skid; mod injection sequences that would benefit Combined would include a 21/2-inch to 2-inch from RWST makeup.adapter. I I III 02=r 3 CD-n Cl)CD CD >-0 CD _> CD o0.9 CL x CD> ~CD CD 0 cn ;:.

Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.7 PHASE II SAMA ANALYSIS A cost-benefit analysis was performed on each of the SAMA candidates remaining after the Phase I screening.

The benefit of a SAMA candidate is the difference between the baseline cost of severe accident risk (maximum benefit from Section F.4.5) and the cost of severe accident risk with the SAMA implemented (Section F.7.1). The cost used is the estimated cost to implement the specific SAMA. If the estimated cost of implementation exceeds the benefit of implementation, the SAMA is not cost-beneficial.

F.7.1 SAMA BENEFIT F.7.1.1 SEVERE ACCIDENT RISK WITH SAMA IMPLEMENTED Bounding analyses were used to determine the change in risk following implementation of SAMA candidates or groups of similar SAMA candidates.

For each analysis case, the Level 1 internal events or Level 2 PRA models were altered to conservatively consider implementation of the SAMA candidate(s).

Then, severe accident risk measures were calculated using the same procedure used for the baseline case described in Section F.3. The changes made to the PRA models for each analysis case are described in Appendix F.A.Two example cases of a "bounding analysis" are provided below: LBLOCA This analysis case example evaluates the change in plant risk profile that would be achieved if a proposed digital large break LOCA protection system was installed.

Although the proposed change would not completely eliminate the potential for a large break LOCA, a bounding benefit is estimated by removing the entire large break LOCA initiating event, thus eliminating its contribution to core damage and to containment release DCPWR This analysis case example evaluates plant modifications proposed to increase the availability of Class 1E DC power (e.g., increased battery capacity or the installation of a diesel-powered generator that would effectively increase battery capacity).

Although the proposed SAMAs would not completely eliminate the potential failure, a bounding benefit is estimated by removing the entire battery discharge and failure events, thus eliminating their contribution to core damage and to containment release.The severe accident risk measures were obtained for each analysis case by modifying the baseline model in a simple manner to capture the effect of implementation of the SAMA in a bounding manner. Bounding analyses are very conservative and result in overestimation of the benefit of the candidate analyzed.

If this bounding assessment yields a benefit that is smaller than the cost of implementation, then refining the PRA modeling approach for the Seabrook Station Unit 1 Page F-125 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives SAMA would be unnecessary because it would only yield a lower benefit result. If the benefit is greater than the cost when modeled in this bounding approach, it is necessary to refine the PRA model of the SAMA to remove conservatism.

As a result of this modeling approach, models representing the Phase II SAMAs will not all be at the same level of detail and if any are implemented, the PRA result after implementation of the final installed design will differ from the screening analyses done to support this evaluation.

F.7.1.2 COST OF SEVERE ACCIDENT RISK WITH SAMA IMPLEMENTED Using the risk measures determined as described in Section F.7.1.1, severe accident impacts in four areas (off-site exposure cost, off-site economic cost, on-site exposure cost, and on-site economic cost) were calculated using the same procedure used for the baseline case described in Section F.4. As in Section F.4.5, the severe accident impacts were summed to estimate the total cost of severe accident risk with the SAMA implemented.

F.7.1.3 SAMA BENEFIT CALCULATION The respective SAMA benefit was calculated by subtracting the total cost of severe accident risk with the SAMA implemented from the baseline cost of severe accident risk (maximum benefit from Section F.4.5). The estimated benefit for each SAMA candidate is listed in Table F.7-1. The calculation of the benefit is done in an Excel spreadsheet.

F.7.2 COST OF SAMA IMPLEMENTATION The final step in the evaluation of the SAMAs is estimating the cost of implementation for comparison with the benefit. For the purpose of this analysis the Seabrook Station staff has estimated that the cost of making a change to a procedure and for conducting the necessary training on a procedure change is expected to exceed $15,000 depending upon the scope of change. Similarly, the minimum cost associated with development and implementation of an integrated hardware modification package (including post-implementation costs, e.g. training) is expected to exceed $100,000.These values were used for initial comparison with the benefit of SAMAs.The benefits resulting from the bounding estimates presented in the benefit analysis are in some cases rather low. In those cases for which the benefits are so low that it is obvious that the implementation costs would exceed the benefit, a detailed cost estimate was not warranted.

Plant staff judgment is applied in assessing whether the benefit approaches the expected implementation costs in many cases.Plant staff judgment was obtained from an independent, expert panel consisting of senior staff members from the PRA group, the design group, operations and license renewal. This panel reviewed the benefit calculation Seabrook Station Unit 1 License Renewal Application Page F-126 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives results and, based on their experience with developing and implementing modifications at the plant, judged if a modification would be cost beneficial in comparison with the calculated benefit. The purpose of this approach was to minimize the effort expended on detailed cost estimation.

The cost estimations provided by the expert panel are included in Table F.7-1 along with the conclusions reached for each SAMA evaluated for cost/benefit.

The results of the sensitivities of Section F.8 influenced the decisions of whether a SAMA was considered to be potentially cost beneficial.

If the benefits calculated in the sensitivity analyses exceeded the estimated cost of the SAMA, it was considered potentially cost beneficial.

Seabrook Station Unit 1 License Renewal Application Page F-127 r- C/)OCD CD 0 0 CD 0 CD C/)0)0 CD-n Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 2 Replace lead- Extended DC 27.08% 12.19% NOSBO This case is used $155K >$1M Expert Not Cost- Cost will acid batteries power to determine the Panel Beneficial exceed with fuel cells, availability benefit of benefit.during an SBO. eliminating all Station Blackout events. This allows evaluation of possible improvements related to SBO sequences.

For the purpose of the analysis, a single bounding analysis is performed that assumes the Diesel Generators do not fail.CD-n, CD)CD>CD>> CD C) D-CL CL~0>CD CD M CDO w-.

I-CD CD CD=__CD 0 R')0" M-Wl CD 0)0 0 X,)0 C: Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 13 Install an Reduced 42.08% 36.20% NOLOSP This case was used to $335K >$1M Expert Not Cost- Cost will additional, probability of determine the benefit Panel Beneficial exceed buried off-site loss of off-site of eliminating all loss of benefit.power power. offsite power events, source. both as the initiating event and subsequent to a different initiating event. This allows evaluation of various possible improvements that could reduce the risk associated with loss of offsite power events. For the purposes of the analysis, a single bounding analysis was performed which assumed that loss of offsite power events do not occur, both as an initiating event and subsequent to a different initiating event.0=r 3 CD)CD CD>CD> CD"0"1 0) C-C X CDm-IM S0.>CD-CDW CDO CD 0.CD (.0 cD-0 CD Ci0 0)0 Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 14 Install a gas Increased 42.08% 36.20% NOLOSP This case was used to $335K $>1M Expert Not Cost- Cost will turbine availability of determine the benefit Panel Beneficial exceed generator.

on-site AC of eliminating all loss of benefit.power. offsite power events, both as the initiating event and subsequent to a different initiating event. This allows evaluation of various possible improvements that could reduce the risk associated with loss of offsite power events. For the purposes of the analysis, a single bounding analysis was performed which assumed that loss of offsite power events do not occur, both as an initiating event and subsequent to a different initiating event.=r 3"3)CD-n, C', CD CD>>CD> CD 0 M-CD CDm w;_.0s CD CD CD C)0 W)CD 0)0" 0 0'0 C: Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 16 Improve Increased 42.08% 36.20% NOLOSP This case was used to $335K >$1M Expert Not Cost- Cost will uninterruptibl availability of determine the benefit Panel Beneficial exceed e power power of eliminating all loss of benefit.supplies, supplies offsite power events, supporting both as the initiating front-line event and subsequent equipment.

to a different initiating event. This allows evaluation of various possible improvements that could reduce the risk associated with loss of offsite power events. For the purposes of the analysis, a single bounding analysis was performed which assumed that loss of offsite power events do not occur, both as an initiating event and subsequent to a different initiating event.20 Add a new Increased 27.08% 12.19% NOSBO This case is used to $155K >$1M Expert Not Cost- Cost will backup diesel determine the benefit Panel Beneficial exceed source of generator of eliminating all benefit.diesel availability.

Station Blackout cooling, events. This allows evaluation of possible improvements related to SBO sequences.

For the purpose of the analysis, a single bounding analysis is performed that assumes the Diesel Generators do not fail.0 3 CD-n CD (0 >>CD>CD 0 D 0.C1 0)->CD~CD CDO CD 0 CD-nl 3'CD CD 0)CD 0 0 MCA-CD 0 0 o'0 0 CD PQ, Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 21 Develop Increased 1.39% 0.42% BREAKER Assume no failures of $8K >$25K Expert Not Cost- Cost will procedures probability of 4KV bus infeed Panel Beneficial exceed to repair or recovery from breakers benefit.replace failed failure of 4 KV breakers that breakers.

transfer 4.16 kV non-emergency buses from unit station service transformers.

24 Bury off-site Improved off- 42.08% 36.20% NOLOSP This case was used to $335K >$1M Expert Not Cost- Cost will power lines, site power determine the benefit Panel Beneficial exceed reliability of eliminating all loss of benefit.during severe offsite power events, weather. both as the initiating event and subsequent to a different initiating event. This allows evaluation of various possible improvements that could reduce the risk associated with loss of offsite power events. For the purposes of the analysis, a single bounding analysis was performed which assumed that loss of offsite power events do not occur, both as an initiating event and subsequent to a -different initiating event.0=r CD CD>>CD c0 M 0 IL CD~0 3'> CD~CDW CD 0

~.CD CDCD2 CD 0 0 CD CD 0)0 0 CD 7', Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 25 Install an Improved 67.71% 51.61% LOCA02 Assume High Pressure $470K >$1M Expert Not Cost- Cost will independent prevention of Injection system does Panel Beneficial exceed active or core melt not fail. benefit.passive high sequences.

pressure injection system.26 Provide an Reduced 67.71% 51.61% LOCA02 Assume High Pressure $470K >$1M Expert Not Cost- Cost will additional frequency of Injection system does Panel Beneficial exceed high pressure core melt from not fail. benefit.injection small LOCA pump with and SBO independent sequences.

diesel.28 Add a Improved 11.11% 28.63% LOCA03 Assume Low Pressure $160K >$1M Expert Not Cost- Cost will diverse low injection injection system does Panel Beneficial exceed pressure capability, not fail. benefit.injection system.35 Throttle low Extended 28.47% 12.47% LOCA04 Assume RWST does $158K >$500K Expert Not Cost- Cost will pressure reactor water not run out of water. Panel Beneficial exceed injection storage tank benefit.pumps earlier capacity.

Current valve in medium or & controls do large-break not allow LOCAs to throttling.

maintain Modification reactor water required.storage tank inventory.

0 CD:'n C,)CD CD >>CD 0 : 0CL a R,~0 5'> CD CD ()~CD CD 0 (n ;.

3'CD CD M M0"=CD 0 CD 9ý*0,-0 0)(0 CD TI Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 39 Replace two Reduced 67.71% 51.61% LOCA02 Assume High Pressure $470K >$1M Expert Not Cost- Cost will of the four common cause Injection system does Panel Beneficial exceed electric failure of the not fail. benefit.safety safety injection injection system. This pumps with SAMA was diesel- originally powered intended for the pumps. Westinghouse-CE System 80+, which has four trains of safety injection.

However, the intent of this SAMA is to provide diversity within the high-and low-pressure safety injections systems.41 Create a Allows low 6.94% 1.82% LOCA01 Eliminate all small $33.3K >$1M Expert Not Cost- Cost will reactor pressure LOCA events. Panel Beneficial exceed coolant emergency benefit.depressurizat core cooling ion system. system injection in the event of small LOCA and high-pressure safety injection failure.0)0r 3 CD-n C', CD CD >>CD>2 CD 0 CL CD m~0 3>CD CD CD 0 wP ;.

3' CD)CD 0)CD 0 0 CD*0 03 0)Ro CD-n, CA)Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 43 Add Increased 0.69% 1.45% SWO1 Remove the $9.8K >$100K Expert Not Cost- Cost will redundant availability of dependency of the Panel Beneficial exceed DC control SW. Service Water pumps benefit.power for SW on DC power. This pumps. case is used to determine the benefit of enhancing the DC control power to the service water pumps.44 Replace Elimination of 25.00% 22.56% CCW01 Assume the CCW $183K >$500K Expert Not Cost- Cost will ECCS pump ECCS pumps do not fail. This Panel Beneficial exceed motors with dependency case was used to benefit.air-cooled on component determine the benefit motors. cooling of improvements to the system. CCW system.55 Install an Reduced 11.81% 12.28% RCPLOCA This case was used to $82.2K >$1M Expert Not Cost- Cost will independent frequency of determine the benefit Panel Beneficial exceed reactor core damage of eliminating all RCP benefit.coolant pump from loss of seal LOCA events.seal injection component This allows evaluation system, with cooling water, of various possible dedicated service water, improvements that diesel. or station could reduce the risk blackout.

associated with RCP seal LOCA and other small LOCA events.56 Install an Reduced >$3M Expert Not Cost- Cost will independent frequency of Panel Beneficial exceed reactor core damage benefit.coolant pump from loss of Note (1)seal injection component system, cooling water without or service dedicated water, but not diesel. a station blackout.0)CD-n C,)CD CD >-0I (0~0D 0 CD CDOM CD CD X CD MD CD U)CD 0 0 A*0 Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 59 Install an Reduced 25.00% 22.56% CCWO1 Assume the CCW $183K >$500K Expert Not Cost- Cost will additional likelihood of pumps do not fail. This Panel Beneficial exceed component loss of case was used to benefit.cooling water component determine the benefit pump. cooling water of improvements to the leading to a CCW system.reactor coolant pump seal LOCA.65 Install a Reduced $30M Current Not Cost- Cost is digital feed chance of loss estimate for Beneficial greater than water. of main feed cost of MAB upgrade. water installation Note (1)following a plant trip.77 Provide a Reduced >$3M Expert Not Cost- Cost will passive, potential for Panel Beneficial exceed secondary-core damage benefit.side heat- due to loss-of- Note (1)rejection loop feedwater consisting of events.a condenser and heat sink.80 Provide a Increased 7.64% 0.98% HVAC2 Remove HVAC $32K >$500K Expert Not Cost- Cost will redundant availability of dependency for CS, SI, Panel Beneficial exceed train or components RH and CBSpray benefit.means of dependent on pumps.ventilation, room cooling.90 Create a Enhanced >$3M Expert Not Cost- Cost will reactor cavity debris cool Panel Beneficial exceed flooding ability, benefit.system. reduced core Note (1)concrete interaction, and increased fission product scrubbing.

0)CD-n Cf CD CD >> CD_ X 0C E )<0)0-CD CD W CDO CD 0 CD ,-n 1CD 5'DCW CD 0 0;0X CDO 0)-0 C)CD-n4 Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 91 Install a Improved >$3M Expert Not Cost- Cost will passive containment Panel Beneficial exceed containment spray benefit.spray capability.

Note (1)system.93 Install an Increased

>$3M Expert Not Cost- Cost will unfiltered, decay heat Panel Beneficial exceed hardened removal benefit.containment capability for Note (1)vent. non-ATWS events, without scrubbing released fission products.94 Install a Increased 0.00% 35.92% CONT01 Eliminate all $163K >$500K Expert Not Cost- Cost will filtered decay heat containment failures Panel Beneficial exceed containment removal due to benefit.vent to capability for overpressurization remove non-ATWS from all causes.decay heat. events, with Option 1: scrubbing of Gravel Bed released Filter; Option fission 2: Multiple products.Venturi Scrubber 96 Provide post- Reduced 0.00% -0.05% H2BURN Eliminate all hydrogen $<1K >$100K Expert Not Cost- Cost will accident likelihood of ignition/burns.

Panel Beneficial exceed containment hydrogen and benefit.inserting carbon capability, monoxide gas combustion.

0)CD Cl)CD CD >> CD o =~a. X CD~0>CD-CDW CDO CD 0 0 C-CID CD:3 CD 0=3 U), CD 0~0 0 C Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMVIA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 97 Create a Increased

>$3M Expert Not Cost- Cost wilt large cooling and Panel Beneficial exceed concrete containment benefit.crucible with of molten core Note (1)heat removal debris.potential to Molten core contain debris molten core escaping from debris, the vessel is contained within the crucible and a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.0 CD-n, C,, CD CD >>CD 0 0 0~CLD CID>CDO 5; ýCD ,'

CD V)CD Xd CD CD 0 C', CD a)0 0 0 Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 98 Create a core Increased

>$3M Expert Not Cost- Cost will melt source cooling and Panel Beneficial exceed reduction containment benefit.system. of molten core Note (1)debris.Refractory material would be placed underneath the reactor vessel such that a molten core falling on the material would melt and combine with the material.Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.99 Strengthen Reduced >$3M Expert Not Cost- Cost will primary/seco probability of Panel Beneficial exceed ndary containment benefit.containment over- Note (1)(e.g., add pressurization.

ribbing to containment shell).0)C)3 CD-n, U)CD CD >>CD CD m (0>CD CDW W CD CD 0 CD-n F CD CD W CD 0 0 CD U CDO 0> C: '0 CD-n, C)Table F.7-1 Seabrook Station I Phase It SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 100 Increase Reduced >$3M Expert Not Cost- -Cost will depth of the probability of Panel Beneficial exceed concrete base mat benefit.base mat or melt-through.

Note (1)use an alternate concrete material to ensure melt-through does not occur.101 Provide a Increased

>$3M Expert Not Cost- Cost will reactor potential to Panel Beneficial exceed vessel cool a molten benefit.exterior core before it Note (1)cooling causes vessel system. failure, by submerging the lower head in water.102 Construct a Reduced >$3M Expert Not Cost- Cost will building to be probability of Panel Beneficial exceed connected to containment benefit.primary/ over- Note (1)secondary pressurization.

containment and maintained at a vacuum.106 Install Extended time 28.47% 12.47% LOCA04 Assume RWST does $158K >$500K Expert Not Cost- Cost will automatic over which not run out of water. Panel Beneficial exceed containment water remains benefit.spray pump in the reactor header water storage throttle tank, when full valves, containment spray flow is not needed.CD CD>>CD C. =0 CL CDO CnM CD CD)CD MD CD 0)a, C/)CD 0, 0 0 0 4 Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 107 Install a Increased

>$3M Expert Not Cost- Cost will redundant containment Panel Beneficial exceed containment heat removal benefit.spray ability. Note (1)system.108 Install an Reduced 0.00% -0.05% H2BURN Eliminate all hydrogen $<1K >$100K Expert Not Cost- Cost will independent hydrogen ignition/burns.

Panel Beneficial exceed power supply detonation benefit.to the potential.

hydrogen control system using either new batteries, a non-safety grade portable generator, existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel.109 Install a Reduced 0.00% -0.05% H2BURN Eliminate all hydrogen $<1K >$100K Expert Not Cost- Cost will passive hydrogen ignition/burns.

Panel Beneficial exceed hydrogen detonation benefit.control potential.

system.0 CD Cl)CD CD >>CD 'o0~0~ =CD C0>CD-CDW CD 0 Cn ;.CD 4.r~

I--CD CD CD CD 0 Ul)CD a-0~0 0 U,)0 C Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 110 Erect a Reduced >$3M Expert Not Cost- Cost will barrier that probability of Panel Beneficial exceed would containment benefit.provide failure. Note (1)enhanced protection of the containment walls (shell)from ejected core debris following a core melt scenario at high pressure.112 Add Reduced 0.00% 37.41% CONT02 Eliminate all $209K >$500K Expert Not Cost- Cost will redundant frequency of containment isolation Panel Beneficial exceed and diverse containment failures.

benefit.limit switches isolation to each failure and containment ISLOCAs.isolation valve.113 Increase leak Reduced 2.08% 6.96% LOCA06 Eliminate all ISLOCA $28.OK >$100K Expert Not Cost- Cost will testing of ISLOCA events. Panel Beneficial exceed valves in frequency.

benefit.ISLOCA paths.114 Install self- Reduced 0.00% 37.41% CONT02 Eliminate all $209K >$500K Expert Not Cost- Cost will actuating frequency of containment isolation Panel Beneficial exceed containment isolation failures.

benefit.isolation failure.valves.115 Locate Reduced 2.08% 6.96% LOCA06 Eliminate all ISLOCA $28.OK >$1M Expert Not Cost- Cost will residual heat frequency of events. Panel Beneficial exceed removal ISLOCA benefit.(RHR) inside outside containment containment.

CD C,)CD CD>> CD~0>CL CDO CO CD 3*CD CD 0)CD 0 0 C> cl 0 9V 0)G CA)Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 119 Institute a Reduced 3.47% 16.72% NOSGTR This case was used to $86.1K >$500K Expert Not Cost- Cost maintenance frequency of determine the benefit Panel Beneficial exceeds practice to steam of eliminating all SGTR benefit.perform a generator tube events. This allows 100% ruptures.

evaluation of various inspection of possible improvements steam that could reduce the generator risk associated with tubes during SGTR events. For the each purposes of the refueling analysis, a single outage. bounding analysis was performed which assumed that SGTR events do not occur.121 Increase the Eliminates 3.47% 16.72% NOSGTR This case was used to $86.1K >$500K Expert Not Cost- Cost will pressure release determine the benefit Panel Beneficial exceed capacity of pathway to the of eliminating all SGTR benefit.the environment events. This allows secondary following a evaluation of various side so that a steam possible improvements steam generator tube that could reduce the generator rupture. risk associated with tube rupture SGTR events. For the would not purposes of the cause the analysis, a single relief valves bounding analysis was to lift. performed which assumed that SGTR events do not occur.0 3 CD C)CD CD >-V CD "> CD 0 0.0..X CD~0> CDCD FC* C CD 0)CD 0 0 CD~f 0'0 CD I-In Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 125 Route the Reduced 3.47% 16.72% NOSGTR This case was used to $86.1K >$500K Expert Not Cost- Cost will discharge consequences determine the benefit Panel Beneficial exceed from the of a steam of eliminating all SGTR benefit.main steam generator tube events. This allows safety valves rupture. evaluation of various through a possible improvements structure that could reduce the where a risk associated with water spray SGTR events. For the would purposes of the condense the analysis, a single steam and bounding analysis was remove most performed which of the fission assumed that SGTR products, events do not occur.126 Install a Reduced 3.47% 16.72% NOSGTR This case was used to $86.1K >$500K Expert Not Cost- Cost will highly consequences determine the benefit Panel Beneficial exceed reliable of a steam of eliminating all SGTR benefit.(closed loop) generator tube events. This allows steam rupture. evaluation of various generator possible improvements shell-side that could reduce the heat removal risk associated with system that SGTR events. For the relies on purposes of the natural analysis, a single circulation bounding analysis was and stored performed which water assumed that SGTR sources events do not occur.0 3 CD-n, C,, CD CD >CD> CD o M.Q. X~0 CD..CD CD 0 (n;:1, CD CD XD CD CD CD C')CD 0)a-0 0 0'Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 129 Vent main Reduced 3.47% 16.72% NOSGTR This case was used to $86.1K >$500K Expert Not Cost- Cost will steam safety consequences determine the benefit Panel Beneficial exceed valves in of a steam of eliminating all SGTR benefit.containment, generator tube events. This allows rupture. evaluation of various possible improvements that could reduce the risk associated with SGTR events. For the purposes of the analysis, a single bounding analysis was performed which assumed that SGTR events do not occur.130 Add an Improved 2.78% 10.98% NOATWS This case was used to $70.2K >$500K Expert Not Cost- Cost will independent availability of determine the benefit Panel Beneficial exceed boron boron injection of eliminating all ATWS benefit.injection during ATWS. events. For the system. purposes of the analysis, a single bounding analysis was performed which assumed that ATWS events do not occur.131 Add a system Improved 2.78% 10.98% NOATWS This case was used to $70.2K >$500K Expert Not Cost- Cost will of relief equipment determine the benefit Panel Beneficial exceed valves to availability of eliminating all ATWS benefit.prevent after an events. For the equipment ATWS. purposes of the damage from analysis, a single pressure bounding analysis was spikes during performed which an ATWS. assumed that ATWS events do not occur.0>3 CD_n"13 C,)CD CD >>CD>CD 0.-CL 0 CDm>CD CDO CD 0 0)CD-n, 4h.

F9 CD CDC0O CDW 0 0) M (0 CD-n, Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 133 Install an Increased 2.78% 10.98% NOATWS This case was used to $70.2K >$500K Expert Not Cost- Cost will ATWS sized ability to determine the benefit Panel Beneficial exceed filtered remove of eliminating all ATWS benefit.containment reactor heat events. For the vent to from ATWS purposes of the remove events. analysis, a single decay heat. bounding analysis was performed which assumed that ATWS events do not occur.147 Install digital Reduced 9.72% 12.38% LOCA05 Eliminate all piping $103K >$500K Expert Not Cost- Cost will large break probability of a failure LOCAs. No Panel Beneficial exceed LOCA large break change to non-piping benefit.protection LOCA (a leak failure LOCAs, such as system. before break). SGTR, RCP seal LOCA, stuck open SRV/PORV, or ISLOCA.153 Install Prevents 0.00% 0.42% NOSLB This case was used to $3.1K >$500K Expert Not Cost- Cost will secondary secondary determine the benefit Panel Beneficial exceed side guard side of installing secondary benefit.pipes up to depressurizati side guard pipes up to the main on should a the MSIVs. This would steam steam line prevent secondary side isolation break occur depressurization valves, upstream of should a steam line the main break occur upstream steam of the MSIVs. For the isolation purposes of the valves. Also analysis, a single guards bounding analysis was against or performed which prevents assumed that no consequential steam line break multiple steam events occur.generator tube ruptures following a main steam line break event.0 CD-n Cl)CD CD >>CD o0.CL CD> CD CDO

>cj r-CDW CD 0 0 C,-CD.0 0 0 CD'1 4r~Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 154 Modify SEPS Improve 27.08% 12.19% NOSBO This case is used to $155K >$750k Expert Not Cost- Cost will design to reliability of determine the benefit Panel Beneficial exceed accommodat onsite power; of eliminating all benefit.e: (a) reduce SBO Station Blackout automatic CDF events. This allows bus loading, contribution; evaluation of possible (b) automatic remove improvements related bus dependence to SBO sequences.

alignment, on operator For the purpose of the action. analysis, a single bounding analysis is performed that assumes the Diesel Generators do not fail.156 Install Improve offsite 42.08% 36.20% NOLOSP This case was used to $335K ->$1M Expert Not Cost- Cost will alternate power reliability determine the benefit Panel Beneficial exceed offsite power and of eliminating all loss of benefit.source that independence o offsite power events, bypasses the switchyard and both as the initiating switchyard.

SF6 bus duct; event and subsequent For example, allow restoratio to a different initiating use campus of offsite power event. This allows power source within a few evaluation of various to energize hours. possible improvements Bus E5 or that could reduce the E6. risk associated with loss of offsite power events. For the purposes of the analysis, a single bounding analysis was performed which assumed that loss of offsite power events do not occur, both as an initiating event and subsequent to a different initiating event.0=r 3 CD ClO CD CD>-. -CD --> CD 0' =0C-L X>CDm> ~CD CDO CD 0.

CD CD CD)CD 0)0)M CD 0)0 0 Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAIVMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 157 Provide Reduce CDF 4.17% 1.91% INDEPAC benefit of independent

$23K $30K Cost for 480V Potentially Case benefit independent of long term AC power to battery generator, Cost- for uncertaint AC power SBO chargers, applicable to cables, Beneficial sensitivity cas source for sequences; SAMA 157 procedure for is $45K.battery extend battery use, and Independent chargers.

For life to allow training.

AC power example, additional time source for provide for recovery, battery portable chargers is a generator to plant-specific charge item identified station via the IPE.battery.159 Install Reduce CDF 4.17% 1.91% INDEPAC benefit of independent

$23K >$1M Batteries, Not Cost- Cost will additional of long term AC power to battery charger, Beneficial exceed batteries.

SBO chargers, applicable to cabling, new benefit.sequences; SAMA 157 building to extend battery house batterie, life to allow ongoing additional time maintenance for recovery, costs.161 Modify EDG Alternate 27.08% 12.19% NOSBO This case is used to $155K >$500K Expert Not Cost- Cost will jacket heat cooling to both determine the benefit Panel Beneficial exceed exchanger EDGs would of eliminating all benefit.service water reduce CDF Station Blackout supply and long term events. This allows return to sequences evaluation of possible allow timely involving improvements related alignment of LOOP and to SBO sequences.

alternate loss of SW For the purpose of the cooling water /cooling tower. analysis, a single source A loss of bounding analysis is (supply & service water / performed that drain) from cooling tower assumes the Diesel firewater, with a LOOP Generators do not fail.RMW, DW, could result in etc. EDG failure and non-recovery.0 C)3 CD-n, U')CD CD >>CD C'_0.>CD CL X>CDm> CD CDO CD-T

~*CD CD 0 CD00 CD Cn M W 0, 0 0, CD-In Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 162 Increase the Extend long 1.39% 0.51% CST01 Assume the CST does $8.6K >$100K Expert Not Cost- Cost will capacity term operation not run out of water Panel Beneficial exceed margin of the of EFW and thus does not benefit.CST. without need to be refilled.operator This case is used to action for CST evaluate methods of makeup for CST refill.sequences that do not go to cold shutdown.Enhance CST margin for design-basis seismic event with cooldown via SG and transition to RHR.0, CD-n, C,, CD CD >CD> CD o o1 0 CL CD 0<30> CD~CD CD 0 cn;l.

CD CD XD CD 0)0 n 0)CD 0 0 0 Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 163 Install third Reduce CDF 18.75% 8.64% TDAFW Assume TDAFW train $100K >$250K Expert Not Cost- Cost will EFW pump of SBO does not fail Panel Beneficial exceed (steam- sequences by benefit.driven), improving overall reliability of EFW system independent of AC power.An additional pump might also have a Level 2 benefit by maintaining coverage of SG tubes thus reducing the release potential for induced SGTR given high pressure core melt sequence.164 Modify 10" Possible 1.39% 0.51% CST01 Assume the CST does $8.6K $40k Expert Not Cost- Cost will Condensate enhancement not run out of water Panel Beneficial exceed Filter Flange of long term and thus does not benefit.to have a core damage need to be refilled.2,-inch sequences that This case is used to female fire credit CST evaluate methods of hose adapter makeup. CST refill.with isolation valve.0 CD C,)CD CD >>CD o0. C E X CD (0> CD-CD CD 0 (n ;:.CD 711 Cn C) 0 CD V')CD XD CD C)0)0 W, CD 0)a'0 0 C Table F.7-1 Seabrook Station I Phase U SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 165 RWST fill Could 10.42% 7.52% NORMW PRA case assumes $75K $50K Expert Potentially from enhance long that RWST makeup for Panel Cost-firewater term long term sequences Beneficial during containment without recirculation containment injection are guaranteed injection

-sequences success.Modify 6" that would RWST Flush benefit from Flange to RWST have a 21/2- makeup.inch female fire hose adapter with isolation valve.167 Install Reduce CDF 11.81% 12.28% RCPLOCA This case was used to $82.2K >$1M Expert Not Cost- Cost will independent contribution determine the benefit Panel Beneficial exceed seal injection from RCP seal of eliminating all RCP benefit.pump (low LOCA events seal LOCA events.volume driven by seal This allows evaluation pump) with cooling of various possible automatic hardware improvements that start, failures.

could reduce the risk associated with RCP seal LOCA and other small LOCA events.168 Install Reduce CDF 11.81% 12.28% RCPLOCA This case was used to $82.2K >$1M Expert Not Cost- Cost will independent contribution determine the benefit Panel Beneficial exceed seal injection from RCP seal of eliminating all RCP benefit.pump (low LOCA events seal LOCA events.volume driven by seal This allows evaluation pump) with cooling of various possible manual start, hardware improvements that failures.

could reduce the risk associated with RCP seal LOCA and other small LOCA events.0)=r 3 CD-n C')CD CD >>CD> CD~CL CD M.cn CD-n 01 0 U)C CD 0 0 CDcI CDO 0>0 0)0 CD TI Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SALVIA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 169 Install Reduce CDF 11.81% 12.28% RCPLOCA This case was used to $82.2K >$500K Expert Not Cost- Cost will independent contribution determine the benefit Panel Beneficial exceed charging from RCP seal of eliminating all RCP benefit.pump (high LOCA events seal LOCA events.volume driven by seal This allows evaluation pump) with cooling of various possible manual start hardware improvements that failures; could reduce the risk improve decay associated with RCP heat removal seal LOCA and other using feed & small LOCA events.bleed.170 Replace the Reduce CDF 11.81% 12.28% RCPLOCA This case was used to $82.2K >$500K Expert Not Cost- Cost will Positive contribution determine the benefit Panel Beneficial exceed Displacement from RCP seal of eliminating all RCP benefit.Pump (PDP) LOCA events seal LOCA events.with a 3rd driven by seal This allows evaluation centrifugal cooling of various possible charging pump hardware improvements that Consider low failures.

could reduce the risk volume and associated with RCP cooling water seal LOCA and other independence, small LOCA events.0)CD:3 CD, CD>CD>> M.0- X.CD'0 CDO CD 0 6 CD MCOO CD00 CDO 0)0 0)CD-n Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 172 Evaluate Reduce CDF 11.81% 12.28% RCPLOCA This case was used to $82.2K >$1M Expert Not Cost- PRA case installation of a contribution determine the benefit Panel Beneficial RCPLOCA"shutdown from of eliminating all RCP which has a seal" in the transients with seal LOCA events, best RCPs being seal cooling This allows evaluation estimate developed by hardware of various possible benefit of Westinghouse.

failures improvements that $92K and resulting in could reduce the risk an upper RCP seal associated with RCP bound LOCA events, seal LOCA and other benefit of small LOCA events. $176K.This will not be cost beneficial, but Seabrook can take credit for following shutdown seal developme nts and industry initiatives to lower risk of RCP seal LOCA events.The budgetary estimated cost to replace 4 RCP seals with new shutdown seal when available is>$1M.CD)-n, C', CD CD >>CD>CD~0M 0 CL-CD>COD CDl~

0 I-CD CD XD CD 0)0 M C')CD a)C-0 0 0, M)Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 174 Provide Improve 2.78% 10.98% NOATWS This case was used to $70.2K >$500K Expert Not Cost- Cost will alternate reliability of determine the benefit Panel Beneficial exceed scram button reactor scram of eliminating all ATWS benefit.to remove by providing events. For the power from remote- purposes of the MG sets to manual analysis, a single CR drives, capability to bounding analysis was remove rod performed which drive power assumed that ATWS should the events do not occur.reactor trip breakers fail;reduce ATWS contribution.

175 Install fire Improve fire 0.00% 0.14% FIRE2 SAMA#175-This case $3K >$10K Expert Not Cost- Cost will detection in detection and eliminates initiator Panel Beneficial exceed turbine manual FTBLP, turbine benefit.building relay suppression building fire at west room. actions. wall or relay room causing opening of UAT/RAT breakers and loss of power to emergency buses, to conservatively assess the benefit of installing fire detection in the Relay Room.0)3"1"1 C')CD CD >> CD 0 X 0CD-L X CDr> CD-CD CD CD Cn-1 ,-rl 0 CD Cn)CD X)CD CD 0)M.C')CD 0)0 0 C')0)Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 179 Fire induced Possible 0.69% 0.14% FIRE1 SAMA#179 -This case $4K >$10K Expert Not Cost- Cost will LOCA reduction in eliminates initiator Panel Beneficial exceed response CDF if FCRPL, control room benefit.procedure mitigating fire- fire-induced LOCA from induced (PORV), to assess Alternate LOCA. possible benefit of Shutdown Judged procedure Panel. marginal enhancement for benefit due to handling LOCA at RSS existing Panel.design and guidance to minimize potential for inadvertent PORV interaction.

Thus, likelihood of LOCA with control room uninhabitable for a long period of time is judged low.181 Improve relay Closed. Relay 9.03% 12.19% SEISMIC01 Assume no seismic $102K >$300K Expert Not Cost- Cost will chatter chatter fragility relay chatter failures Panel Beneficial exceed fragility.

judged low occur, split fraction QK. benefit.contributor to This case is used to CDF. evaluate the impact of Significant improvements that uncertainty in would eliminate hazard and seismic relay chatter fragility not events.easily removed and beyond state-of-the-art as stated in IPEEE. No further actions needed.0)CD CD CD>CD>CD X>CD> CD~CD CDO U);:1."0)CD ,-n 01 CDD (n~CD0 CD 0 0 0)CD-Ir (.11 Table F.7-1 Seabrook Station I Phase II SAMA Analysis (Continued)

Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 182 Improve Improve 0.00% 0.00% SEISMIC02 Assume no seismic $<1K >$500K Expert Not Cost- Cost will seismic component failures of diesel Panel Beneficial exceed capacity of fragility and generators or turbine benefit.EDGs and reduce driven EFW (split steam-driven seismic event fractions QDG and EFW pump. contribution to QCST).CDF.184 Control/reduc Purge path is 0.00% 0.05% PURGE Eliminate possibility of $<1K $20K Cost of Not Cost- Cost will e time that large opening. containment purge Procedure Beneficial exceed the Reduce valves being open at Change benefit.containment exposure time the time of an event purge valves of open path, (assume purge valves are in open improve always closed).position, reliability/avail ability of Cl, reduce Cl failure contribution to large release.186 Install Improve 0.00% 35.92% CONT01 Eliminate all $163K >$500K Expert Not Cost- Cost will containment containment containment failures Panel Beneficial exceed leakage reliability by due to benefit.monitoring reducing the overpressurization system. potential for from all causes.pre-existing containment leakage.187 Install RHR Reduce 2.08% 6.96% LOCA06 Eliminate all ISLOCA $28.OK >$100K Expert Not Cost- Cost will isolation ISLOCA events. Panel Beneficial exceed valve challenge to benefit.leakage RHR by monitoring identification system. of upstream valve failure.0)C)3 CD C,)CD CD >>CD> CD-. CD E X CID m Table F.7-1 Seabrook Station 1 Phase II SAMA Analysis (Continued)

CD CD X'CD CD CD 0)n)Co CD 0)0*0 0 X'0 Benefit at Seabrook % Red. 7%SAMA Potential

% Red. In OS SAMA SAMA Case Discount Basis for Number Improvement Discussion In CDF Dose Case Description Rate Cost Cost Basis Evaluation Evaluation 189 Modify or Allow all 6.94% 0.98% lof2SEPS benefit of SEPS $30K >$300K Expert Not Cost- Cost will analyze equipment to success criteria Panel Beneficial exceed SEPS be run change, from 2 of 2 benefit.capability; 1 following SEPS DGs to 1 of 2 of 2 SEPS for LOSP with SEPS DGs, applicable LOSP non-SI EDG failure to SAMA 192 loads, 2 of 2 but successful for LOSP SI start and load loads, of SEPS.190 Add Eliminate 27.08% 12.19% NOSBO This case is used to $155K $1M Expert Not Cost- Cost will synchronizati current determine the benefit Panel Beneficial exceed on capability requirement of eliminating all benefit.to SEPS for dead bus Station Blackout Diesel. transfer from events. This allows SEPS to evaluation of possible normal power. improvements related to SBO sequences.

For the purpose of the analysis, a single bounding analysis is performed that assumes the Diesel Generators do not fail.Note (1): Risk reduction not specifically evaluated because estimated cost exceeds the possible maximum averted cost-risk.

0 C)CD-n Co"110 oU)CD ->CD>>) CD 0. X 0CL CL 0)n CD '> CD CD 0 cn :1"o CD"-r, 71 (TI-4 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.8 SENSITIVITY ANALYSES Sensitivity analyses examine the impact of analysis assumptions on the results of the SAMA evaluation.

This section identifies several sensitivities that can be performed during SAMA (Reference 20, NEI 05-01) and discusses the sensitivity as it applies to Seabrook Station and the impact of the sensitivity on the results of the Phase II SAMA analysis at Seabrook Station.Unless it was otherwise noted, it is assumed in these sensitivity analyses that sufficient margin existed in the maximum benefit estimation that the Phase I screening would not have to be repeated in the sensitivity analyses.F.8.1 PLANT MODIFICATIONS There are no plant modifications currently pending that would be expected to impact the results of this SAMA evaluation.

F.8.2 UNCERTAINTY Because the inputs to PRA cannot be known with complete certainty, there is the possibility that the actual plant risk is greater than the mean values used in the evaluation of the SAMA described in the previous sections.

To consider this uncertainty, a sensitivity analysis was performed in which an uncertainty factor was applied to the frequencies calculated by the PRA and the subsequent upper bound (UB) benefits were calculated based upon the mean risk values multiplied by this uncertainty factor. The uncertainty factor applied is the ratio of the 95th percentile value of the CDF from the PRA uncertainty analysis to the mean value of the CDF. For Seabrook Station, the 95th percentile value of the CDF is 2.75E-05/yr; therefore, the uncertainty factor is 1.90. Table F.8-1 provides the benefit results from each of the sensitivities for each of the SAMA cases evaluated.

F.8.3 PEER REVIEW FACTS/OBSERVATIONS The model used in this SAMA analysis includes the resolution of the Facts-and-Observations (F&Os) identified during the PRA Peer Review. Therefore, no specific sensitivities were performed related to this issue.F.8.4 SENSITIVITY TO LEVEL 3 OFFSITE PARAMETERS Sensitivity to some of the Level 3 MACCS2 inputs was investigated to determine their effects on annual risk. The parameters analyzed in the sensitivity investigation included those identified below.Annual Met Data Set -Five years of site meteorological data was evaluated, 2004 through 2008. Meteorological data from year 2005 resulted in the maximum dose and cost risk compared to other years. The 2005 data was used as the baseline case input for meteorology data. Insight gained: Other meteorological data in years 2004, 2006, 2007 and 2008 resulted in Seabrook Station Unit 1 Page F-158 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives decreases to dose and economic risks when compared to the 2005 baseline case.Release Heigqht -Baseline case release was considered at the top height of the containment building.

Sensitivity cases considered releases at ground height and at 25%, 50% and 75% of containment height. Insight gained: Decrease in release height increases close-in deposition of nuclides released.With the decrease in release height, the larger population located downwind would be affected by a depleted plume relative to the baseline case release height. Risks are minimum at ground level; risk increases as release height increases to top of containment.

Release Heat -Baseline case assumed ambient release conditions.

Investigated release heat of 1 and 10 MW released with each of 4 plume segments for each accident category.

Insight gained: Buoyancy associated with increasing heat results in less ground level consequences near release.Risk from some accident categories is relatively more important near the release point.Wake Effects -The effect of building wake on the risk was analyzed because the proximity of other buildings to the Seabrook containment introduces uncertainty as to local air flow around these buildings.

Baseline case wake effects were determined based on the large containment building structure.

The wake size was assumed at one-half the baseline and at double the baseline to address uncertainty of impact from other buildings.

Insight gained: Risk is not sensitive to building wake effects.Evacuation Speed -Baseline case evacuation speed is based on the Seabrook Station Radiological Emergency Plan evaluation considering adverse weather conditions, projected to 2050. Two evacuation sensitivity cases were performed to determine the impact of evacuation speed assumptions.

One sensitivity case used one-half the base case evacuation speed and the second sensitivity case doubled the base case evacuation speed. Insight gained: Dose risk increases as evacuation speed decreases.

Change in dose risk not significant.

Evacuation Preparation Time -Baseline case preparation time is 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> based on the MACCS2 sample problem A. Sensitivity cases considered one-half the baseline time to prepare for evacuation and a doubling of the baseline time. Insight gained: Changing the preparation time had a minor effect on most accident category risks; a slightly larger effect was noted on late containment release categories with risk concentrated near the release.Evacuation Warninq Time -Baseline case emergency declaration time is dependent on the accident progression.

Sensitivity cases considered one-half the baseline time to warn to evacuate (declaration of general emergency) and a doubling of the baseline time. Insight gained: Similar behavior as changes in evacuation preparation time.Seabrook Station Unit 1 Page F-159 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Fraction of Population Evacuating

-The baseline case for population evacuation considers 95% percent of the population within 10 miles of the plant evacuating and 5 percent not evacuating.

This is judged conservative relative to the NUREG 1150 study, which assumed evacuation of 99.5 percent of the population within the emergency planning zone. Release category SE-3 is identified as a risk-dominant release category.

An important contributor to SE-3 is a seismically-induced severe accident event. A sensitivity case was performed which conservatively assumed that the population does not evacuate for the SE-3 release category.

Insight gained: Assumed no evacuation for release category SE-3 results in a small increase to the overall total accident dose-risk, no change to economic risk.Meteorology in Last S.atial Ring Segment -The baseline case considers rain fall imposed within the 40 to 50 mile ring segment from release for all cases to force conservative population exposure, that is, to ensure that a conservatively large quantity of nuclides released in each scenario were deposited via wet deposition.

The sensitivity case allows the meteorology within the 40 to 50 mile ring segment to temporally follow the site meteorology.

Insight gained: Decrease in risk due to removing assumed perpetual rainfall and its resulting wet deposition and instead assumed measured meteorology.

Level 3 Input Sensitivity Investigation Conclusions With the baseline case conservative assumption for meteorology (the maximum risk year 2005 was chosen for the Level-3 analysis), the risks to severe accidents can increase up to approximately 4% as a result of any of the considered parameter changes. The conservatism in the baseline case of specifying perpetual rainfall in the spatial ring from 40 to 50 miles is judged to more than balance any risk increases that might result from alternate release parameters.

Based on the baseline case assumptions and the sensitivity investigations performed, it is concluded that the offsite dose and economic risks are adequately accounted for and are relatively insensitive to reasonable variations in the individual input parameters.

No changes to the evaluation of SAMA candidates are judged necessary based on the Level 3 input sensitivity investigation.

F.8.5 REAL DISCOUNT RATE Calculation of severe accident impacts in the Seabrook SAMA analysis was performed using a "real discount rate" of 7% (0.07/year) as recommended in NUREG/BR-0184 (Reference 16). Use of both a 7% and 3% real discount rate in regulatory analysis is specified in Office of Management Budget (OMB)guidance (Reference

21) and in NUREG/BR-0058 (Reference 22).Therefore, a sensitivity analysis was performed using a 3% real discount rate.In this sensitivity analysis, the real discount rate in the Level 3 PRA model was changed to 3% from 7% and the Phase II analysis was repeated with the lower interest rate.Seabrook Station Unit 1 License Renewal Application Page F-160 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives A sensitivity analysis was also performed using the "best estimate" (BE)discount rate of 8.5%. This represents the discount rate that could be expected for Seabrook Station.The results of the sensitivity analyses are presented in Table F.8-1. The sensitivity results do not challenge any decisions made regarding the SAMAs.F.8.6 ANALYSIS PERIOD As described in Section F.4, calculation of severe accident impacts involves an analysis period term, tf, which could have been defined as either the period of extended operation (20 years), or the years remaining until the end of facility life (from the time of the SAMA analysis to the end of the period of extended operation is 41 years).The value used for this term was the period of extended operation (20 years).This sensitivity analysis was performed using the period from the time of the SAMA analysis to the end of the period of extended operation to determine if SAMAs would be potentially cost-beneficial if performed immediately.

In this sensitivity analysis, the analysis period in the calculation of severe accident risk was modified to 41 years and the Phase II analysis was repeated with the revised analysis period. The cost of additional years of maintenance, surveillance, calibrations, and training were included appropriately in the cost estimates for SAMAs in this Phase II analysis.The results of this sensitivity analysis are presented in Table F.8-1. This sensitivity analysis does not challenge any decisions made regarding the SAMAs.Seabrook Station Unit 1 License Renewal Application Page F-161 CD CD CD 0, 5.C,)CD 0)0r 0 0 C', C: Table F.8-1 Seabrook Station Sensitivity Evaluationa Benefit at Benefit Benefit at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Cost Basis Evaluation Evaluation 2 Replace lead- Extended DC NOSBO $155K $255K $138K $247K $295K >$1M Expert Not Cost- Cost will acid batteries power Panel Beneficial exceed with fuel cells, availability benefit.during an SBO.13 Install an Reduced NOLOSP $335K $527K $298K $502K $638K >$1M Expert Not Cost- Cost will additional, probability of Panel Beneficial exceed buried off-site loss of off-site benefit.power source. power.14 Install a gas Increased NOLOSP $335K $527K $298K $502K $638K $>1M Expert Not Cost- Cost will turbine availability of Panel Beneficial exceed generator, on-site AC benefit.power.16 Improve Increased NOLOSP $335K $527K $298K $502K $638K >$1M Expert Not Cost- Cost will uninterruptible availability of Panel Beneficial exceed power power benefit.supplies, supplies supporting front-line equipment.

20 Add a new Increased NOSBO $155K $255K $138K $247K $295K >$1M Expert Not Cost- Cost will backup source diesel Panel Beneficial exceed of diesel generator benefit.cooling, availability.

0)CD)CD CD >CD>CD>0 M>CD-I> CD CDO Zn...-D a)ON) 3'CD M C-CD00;U;z CD_113 Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 21 Develop Increased BREAKER $8K $13K $7K $13K $15 >$25K Expert Not Cost- Cost will procedures to probability of Panel Beneficial exceed repair or recovery from benefit.replace failed failure of 4 KV breakers that breakers.

transfer 4.16 kV non-emergency buses from unit station service transformers.

24 Bury off-site Improved off- NOLOSP $335K $527K $298K $502K $638K >$1M Expert Not Cost- Cost will power lines. site power Panel Beneficial exceed reliability benefit.during severe weather.25 Install an Improved LOCA02 $470K $751K $418K $720K $894K >$1M Expert Not Cost- Cost will independent prevention of Panel Beneficial exceed active or core melt benefit.passive high sequences.

pressure injection system.26 Provide an Reduced LOCA02 $470K $751K $418K $720K $894K >$1M Expert Not Cost- Cost will additional high frequency of Panel Beneficial exceed pressure core melt from benefit.injection pump small LOCA with and SBO independent sequences.

diesel.28 Add a diverse Improved LOCAO3 $160K $240K $142K $222K $304K >$1M Expert Not Cost- Cost will low pressure injection Panel Beneficial exceed injection capability, benefit.system.CD)-n CD >"- I CD -~0M 52. CL<CD CD 0)SC-CD0 CD Cj CD 0)0>t 0, CD-n, Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 35 Throttle low Extended LOCA04 $158K $260K $140K $253K $300K >$500K Expert Not Cost- Cost will pressure reactor water Panel Beneficial exceed injection storage tank benefit.pumps earlier capacity.

Current in medium or valve &large-break controls do LOCAs to not allow maintain throttling.

reactor water Modification storage tank required.inventory.

39 Replace two Reduced LOCA02 $470K $751K $418K $720K $894K >$1M Expert Not Cost- Cost will of the four common Panel Beneficial exceed electric safety cause failure benefit.injection of the safety pumps with injection diesel- system. This powered SAMA was pumps. originally intended for the Westinghouse-CE System 80+, which has four trains of safety injection.

However, the intent of this SAMA is to provide diversity within the high- and low-pressure safety injections systems.0)CD CD CD >CD -> CD-L X~CD> CD CDO I-cn'CD DO)CD 0)c , -CD 0 0o0-CD-I Cy)Co Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 41 Create a Allows low LOCA01 $33.3K $57K $30K $56K $63K >$1M Expert Not Cost- Cost will reactor pressure Panel Beneficial exceed coolant emergency benefit.depressurizati core cooling on system. system injection in the event of small LOCA and high-pressure safety injection failure.43 Add redundant Increased SWO1 $9.8K $15K $9K $14K $19K >$1OOK Expert Not Cost- Cost will DC control availability of Panel Beneficial exceed power for SW SW. benefit.pumps.44 Replace Elimination of CCWO1 $183K $290K $163K $277K $348K >$500K Expert Not Cost- Cost will ECCS pump ECCS Panel Beneficial exceed motors with dependency benefit.air-cooled on component motors. cooling system.55 Install an Reduced RCPLOCA $82.2K $145K $82K $138K $176K >$1M Expert Not Cost- Cost will independent frequency of Panel Beneficial exceed reactor core damage benefit.coolant pump from loss of seal injection component system, with cooling water, dedicated service water, diesel. or station blackout.0 31 Cnl ( CD CD>> CD CL X CD O;:; ;:3.

3*CD CD Q)CD 0-CD 0 CDO 0)D CY)0)Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 56 Install an Reduced >$3M Expert Not Cost- Cost will independent frequency of Panel Beneficial exceed reactor core damage benefit.coolant pump from loss of Note (1)seal injection component system, cooling water without or service dedicated water, but not diesel. a station blackout.59 Install an Reduced CCWO1 $183K $290K $163K $277K $348K >$500K Expert Not Cost- Cost will additional likelihood of Panel Beneficial exceed component loss of benefit.cooling water component pump. cooling water leading to a reactor coolant pump seal LOCA.65 Install a digital Reduced $30M Current Not Cost- Cost is feed water chance of loss estimate Beneficial greater than upgrade, of main feed for cost of MAB water installation Note (1)following a plant trip.77 Provide a Reduced >$3M Expert Not Cost- Cost will passive, potential for Panel Beneficial exceed secondary-core damage benefit.side heat- due to loss-of- Note (1)rejection loop feedwater consisting of a events.condenser and heat sink.80 Provide a Increased HVAC2 $32K $56K $29K $56K $61K >$500k Expert Not Cost- Cost will redundant availability of Panel Beneficial exceed train or means components benefit.of ventilation, dependent on room cooling.0)CD-n, C,, CD CD >CD '> CD o0.0 CL CD~0 L>CD-CD CDO Cn ;.

I- Ct)F5'CD CD 2)CD 0 0 CD 0 01>CD CDD-n 0T)(0 Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 90 Create a Enhanced >$3M Expert Not Cost- Cost will reactor cavity debris cool Panel Beneficial exceed flooding ability, benefit.system. reduced core Note (1)concrete interaction, and increased fission product scrubbing.

91 Install a Improved >$3M Expert Not Cost- Cost will passive containment Panel Beneficial exceed containment spray benefit.spray system, capability.

93 Install an Increased

>$3M Expert Not Cost- Cost will unfiltered, decay heat Panel Beneficial exceed hardened removal benefit.containment capability for Note (1)vent. non-ATWS events, without scrubbing released fission products.94 Install a Increased CONT01 $163K $227K $145K $204K $310K >$500K Expert Not Cost- Cost will filtered decay heat Panel Beneficial exceed containment removal benefit.vent to capability for remove decay non-ATWS heat. Option 1: events, with Gravel Bed scrubbing of Filter; Option released 2: Multiple fission Venturi products.Scrubber 0)CD CD CD >CDv> CD~0~CLD~CD CDO:Z- -0 CD CD XD CD CD 0)Z CD 0 0-X,, W.:3 Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 96 Provide post- Reduced H2BURN $<1K $<1K $<1K $<1K $<1K >$100K Expert Not Cost- Cost will accident likelihood of Panel Beneficial exceed containment hydrogen and benefit.inserting carbon capability, monoxide gas combustion.

97 Create a large Increased

>$3M Expert Not Cost- Cost will concrete cooling and Panel Beneficial exceed crucible with containment benefit.heat removal of molten core Note (1)potential to debris.contain molten Molten core core debris, debris escaping from the vessel is contained within the crucible and a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.0=r"3 CD CD CD>CD>CD>*0=C.X CD 0)-o> CD-CD 0 CDO CD'<.cn;3 CD ,-1 0)I I-0 C5'CD CD CD 0)0)(n CD a)07 0 0 C Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 98 Create a core Increased

>$3M Expert Not Cost- Cost will melt source cooling and Panel Beneficial exceed reduction containment benefit system. of molten core Note (1)debris.Refractory material would be placed underneath the reactor vessel such that a molten core falling on the material would melt and combine with the material.Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.99 Strengthen Reduced >$3M Expert Not Cost- Cost will primary/secon probability of Panel Beneficial exceed dary containment benefit.containment over- Note (1)(e.g., add pressurization ribbing to containment shell).3 CD-n, (n CD CD>CD '0>CD 0 =-0 CL E RI CD> _CD CD W."o CD ,-n o'1 a) r- (/)FV CD CD 0)CD 0 CD U M CD 0,=3>CD CD Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 100 Increase Reduced >$3M Expert Not Cost- Cost will depth of the probability of Panel Beneficial exceed concrete base base mat benefit.mat or use an melt-through.

Note (1)alternate concrete material to ensure melt-through does not occur.101 Provide a Increased

>$3M Expert Not Cost- Cost will reactor vessel potential to Panel Beneficial exceed exterior cool a molten benefit.cooling core before it Note (1)system. causes vessel failure, by submerging the lower head in water.102 Construct a Reduced >$3M Expert Not Cost- Cost will building to be probability of Panel Beneficial exceed connected to containment benefit.primary/secon over- Note (1)dary pressurization containment and maintained at a vacuum.106 Install Extended time LOCA04 $158K $260K $140K $253K $300K >$500K Expert Not Cost- Cost will automatic over which Panel Beneficial exceed containment water remains benefit.spray pump in the reactor header throttle water storage valves, tank, when full containment spray flow is not needed.0,=r{3:3-nr O')CD:rn'1 CD >CD> CD o a3 0 xL C- X CD O CnM CD a CD 0 0 CDD 0 CD-n Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 107 Install a Increased

>$3M Expert Not Cost- Cost will redundant containment Panel Beneficial exceed containment heat removal benefit.spray system. ability. Note (1)108 Install an Reduced H2BURN $<1K $<1K $<1K $<1K $<1K >$100K Expert Not Cost- Cost will independent hydrogen Panel Beneficial exceed power supply detonation benefit.to the potential.

hydrogen control system using either new batteries, a non-safety grade portable generator, existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel.109 Install a Reduced H2BURN $<1K $<1K $<1K $<1K $<1K >$100K Expert Not Cost- Cost will passive hydrogen Panel Beneficial exceed hydrogen detonation benefit.control potential.

system.0, CD CD CD >CDv> CD o M 0 CL CD~0> CD CDO CD 0 3' C CD 0)"o (n-CD 0 0 ,0-r= _cn CD)0)9.0)CD-n Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8;5% 41 yrs at UB Cost Basis Evaluation Evaluation 110 Erect a barrier Reduced >$3M Expert Not Cost- Cost will that would probability of Panel Beneficial exceed provide containment benefit.enhanced failure. Note (1)protection of the containment walls (shell)from ejected core debris following a core melt scenario at high pressure.112 Add redundant Reduced CONT02 $209K $292K $186K $261K $397K >$500K Expert Not Cost, Cost will and diverse frequency of Panel Beneficial exceed limit switches containment benefit.to each isolation containment failure and isolation valve. ISLOCAs.113 Increase leak Reduced LOCA06 $28.OK $43K $25K $40K $53K >$100K Expert Not Cost- Cost will testing of ISLOCA Panel Beneficial exceed valves in frequency.

benefit.ISLOCA paths.114 Install self- Reduced CONT02 $209K $292K $186K $261K $397K >$500K Expert Not Cost- Cost will actuating frequency of Panel Beneficial exceed containment isolation benefit.isolation failure.valves.115 Locate Reduced LOCA06 $28.OK $43K $25K $40K $53K >$1M Expert Not Cost- Cost will residual heat frequency of Panel Beneficial exceed removal ISLOCA benefit.(RHR) inside outside containment containment.

3>C)CD CD I~03>'"O CD1.

I-c,?5'CD CD 0 0 CD 0= 0.CD 0*0 a:)CD ,-n"W Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 119 Institute a Reduced NOSGTR $86.1K $126K $77K $116K $164K >$500K Expert Not Cost- Cost maintenance frequency of Panel Beneficial exceeds practice to steam benefit.perform a generator 100% tube ruptures.inspection of steam generator tubes during each refueling outage.121 Increase the Eliminates NOSGTR $86.1K $126K $77K $116K $164K >$500K Expert Not Cost- Cost will pressure release Panel Beneficial exceed capacity of the pathway to benefit.secondary the side so that a environment steam following a generator tube steam rupture would generator not cause the tube rupture.relief valves to lift.125 Route the Reduced NOSGTR $86.1K $126K $77K $116K $164K >$500K Expert Not Cost- Cost will discharge consequences Panel Beneficial exceed from the main of a steam benefit.steam safety generator valves through tube rupture.a structure where a water spray would condense the steam and remove most of the fission products.0=r 3 CD-n CD >~00 CD> CD_ =0 CL C1 X CD L> CD CDO (j,rn CDm

'CD CD a)CD 03 CDO ,-rn-4 5.Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 126 Install a highly Reduced NOSGTR $86.1K $126K $77K $116K $164K >$500K Expert Not Cost- Cost will reliable consequences Panel Beneficial exceed (closed loop) of a steam benefit.steam generator generator tube rupture.shell-side heat removal system that relies on natural circulation and stored water sources 129 Vent main Reduced NOSGTR $86.1K $126K $77K $116K $164K >$500K Expert Not Cost- Cost will steam safety consequences Panel Beneficial exceed valves in of a steam benefit.containment, generator tube rupture.130 Add an Improved NOATWS $70.2K $103K $63K $94K $134K >$500K Expert Not Cost- Cost will independent availability of Panel Beneficial exceed boron injection boron benefit.system. injection during ATWS.131 Add a system Improved NOATWS $70.2K $103K $63K $94K $134K >$500K Expert Not Cost- Cost will of relief valves equipment Panel Beneficial exceed to prevent availability benefit.equipment after an damage from ATWS.pressure spikes during an ATWS.133 Install an Increased NOATWS $70.2K $103K $63K $94K $134K >$500K Expert Not Cost- Cost will ATWS sized ability to Panel Beneficial exceed filtered remove benefit.containment reactor heat vent to from ATWS remove decay events.heat.=)C3 CD C"n CD CD >CD CL CD"3> CD CDO FD " un ;:13.

0 OCD CD W CD 0 0 CD W CD 0~-4 U1 Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMVIA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 147 Install digital Reduced LOCA05 $103K $158K $92K $148K $196K >$500K Expert Not Cost- Cost will large break probability of Panel Beneficial exceed LOCA a large break benefit.protection LOCA (a leak system. before break).153 Install Prevents NOSLB $3.1K $5K $3K $5K $6K >$500K Expert Not Cost- Cost will secondary secondary Panel Beneficial exceed side guard side benefit.pipes up to the depressurizati main steam on should a isolation steam line valves, break occur upstream of the main steam isolation valves. Also guards against or prevents consequential multiple steam generator tube ruptures following a main steam line break event.154 Modify SEPS Improve NOSBO $155K $255K $138K $247K $295K >$750k Expert Not Cost- Cost will design to reliability of Panel Beneficial exceed accommodate:

onsite power; benefit.(a) automatic reduce SBO bus loading, CDF (b) automatic contribution; bus alignment, remove dependence on operator action.0)CD-n, CD CD >CD> CD E X~0>CD CD W.CDO CD 0 0 C-CD X2 CD CD CD 0)9V 0)D C,, CD 0)a'0 0)Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 156 Install Improve NOLOSP $335K $527K $298K $502K $638K >$1 M Expert Not Cost- Cost will alternate offsite power Panel Beneficial exceed offsite power reliability and benefit.source that independence bypasses the of switchyard switchyard.

and SF6 bus For example, duct; allow use campus restoration of power source offsite power to energize within a few Bus E5 or E6. hours.157 Provide Reduce CDF INDEPAC $23K $39K $21K $38K $45K $30K Cost for Potentially Case benefit independent of long term 480V Cost- for AC power SBO generator, Beneficial uncertainty source for sequences; cables, sensitivity battery extend battery procedure case is chargers.

For life to allow for use, $45K.example, additional time and Independent provide for recovery, training.

AC power portable source for generator to battery charge station chargers is a battery. plant-specific item identified via the IPE.159 Install Reduce CDF INDEPAC $23K $39K $21K $38K $45K >$1M Batteries, Not Cost- Cost will additional of long term charger, Beneficial exceed batteries.

SBO cabling, benefit.sequences; new extend battery building to life to allow house additional time batteries, for recovery.

ongoing maintenan ce costs.0)CD CD CD >CD -> CD o0~CL X CD> CD CD 0 (n ;I. CD ,--4 0 C-CD CD CD 01 02 C', CD 0)0 0 Xi, W)Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 161 Modify EDG Alternate NOSBO $155K $255K $138K $247K $295K >$500K Expert Not Cost- Cost will jacket heat cooling to Panel Beneficial exceed exchanger both EDGs benefit.service water would reduce supply and CDF long return to allow term timely sequences alignment of involving alternate LOOP and cooling water loss of SW source (supply /cooling tower.& drain) from A loss of firewater, service water/RMW, DW, cooling tower etc. with a LOOP could result in EDG failure and non-recovery.162 Increase the Extend long CST01 $8.6K $15K $8K $14K $16K >$100K Expert Not Cost- Cost will capacity term operation Panel Beneficial exceed margin of the of EFW benefit.CST. without operator action for CST makeup for sequences that do not go to cold shutdown.Enhance CST margin for design-basis seismic event with cooldown via SG and transition to RHR.0)3 CD-n, CD, CD>CD>>CD ->CD> CD>CDW.-CD< U CD 0 cn ;.CD-4l CD 0)n C-CD0 CD Cl)CD 0)(0 CD-n, Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 163 Install third Reduce CDF TDAFW $100K $166K $89K $162K $190K >$250K Expert Not Cost- Cost will EFW pump of SBO Panel Beneficial exceed (steam- sequences by benefit.driven), improving overall reliability of EFW system independent of AC power.An additional pump might also have a Level 2 benefit by maintaining coverage of SG tubes thus reducing the release potential for induced SGTR given high pressure core melt sequence.164 Modify 10" Possible CST01 $8.6K $15K $8K $14K $16K $40k Expert Not Cost- Cost will Condensate enhancement Panel Beneficial exceed Filter Flange of long term benefit.to have a 2V- core damage inch female sequences fire hose that credit adapter with CST makeup.isolation valve.0)3 CD-n, C,)CD CD >CDv> CD o0.CL X CD I (0> CD~CDW CDO (n ;l.

CD CD XD CD CD 0)Cr, CD 0)U~0 0 X,, Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Seabrook SAMA Number Benefit at 7%Discount Rate Benefit at 3%Discount Rate Benefit at BE Discount Rate of 8.5%Potential Improvement Discussion SAMA Case Benefit at 41 yrs Benefit at UB Cost Cost Basis Evaluation Basis for Evaluation 165 RWST fill from Could NORMW $75 $120K $66K $115K $142K $50K Expert Potentially firewater enhance long Panel Cost-during term Beneficial containment containment injection

-injection Modify 6" sequences RWST Flush that would Flange to benefit from have a 2Y- RWST inch female makeup.fire hose adapter with isolation valve.167 Install ReduceCDF RCPLOCA $82.2K $145K $82K $138K $176K >$1M Expert Not Cost- Cost will independent contribution Panel Beneficial exceed seal injection from RCP benefit.pump (low seal LOCA volume pump) events driven with automatic by seal start, cooling hardware failures.168 Install Reduce CDF RCPLOCA $82.2K $145K $82K $138K $176K >$1M Expert Not Cost- Cost will independent contribution Panel Beneficial exceed seal injection from RCP benefit.pump (low seal LOCA volume pump) events driven with manual by seal start, cooling hardware failures.0)3>o0(n CD CD >CD>CD>0 =0 CL CL a CD>CD CD)-)CD CD 0 w;I1.0)CU CD-4, CO CD CD Xl CD CD a, 0 C', CD 0)a-0 0 Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 169 Install Reduce CDF RCPLOCA $82.2K $145K $82K $138K $176K >$500K Expert Not Cost- Cost will independent contribution Panel Beneficial exceed charging from RCP benefit.pump (high seal LOCA volume pump) events driven with manual by seal start cooling hardware failures;improve decay heat removal using feed & bleed.170 Replace the Reduce CDF RCPLOCA $82.2K $145K $82K $138K $176K >$500K Expert Not Cost- Cost will Positive contribution Panel Beneficial exceed Displacement from RCP benefit.Pump (PDP) seal LOCA with a 3rd events driven centrifugal by seal charging cooling pump. hardware Consider low failures.volume and cooling water independence.

a)3 CD"13-n CD CD >> CD o M~EL CL.>CD-CD CDO-0 ,-n 0 r- c 5'CD CD 0)n"O CD 0 0 CD C/CDO'0 0)M-n 0)Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 172 Evaluate Reduce CDF RCPLOCA $82.2K $145K $82K $138K $176K >$1M Expert Not Cost- PRA case installation of contribution Panel Beneficial RCPLOCA a "shutdown from which has a seal" in the transients with best RCPs being seal cooling estimate developed by hardware benefit of Westinghouse.

failures $92K and an resulting in upper bound RCP seal benefit of LOCA events. $176K. This will not be cost beneficial, but Seabrook can take credit for following shutdown seal development s and industry initiatives to lower risk of RCP seal LOCA events. The budgetary estimated cost to replace 4 RCP seals with new shutdown seal when available is>$1M.3 CD-n, C/)CD CD>> CD o D~CL X CD(0~0>CD-CD 0 CDO CD 0 3 CD CD 0)MCD 0 C D 00 CD a, CD )0'a (0 CD-n Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 174 Provide Improve NOATWS $70.2K $103K $63K $94K $134K >$500K Expert Not Cost- Cost will alternate reliability of Panel Beneficial exceed scram button reactor scram benefit.to remove by providing power from remote-MG sets to CR manual drives, capability to remove rod drive power should the reactor trip breakers fail;reduce ATWS contribution.

175 Install fire Improve fire FIRE2 $3K $5K $2K $5K $5K >$10K Expert Not Cost- Cost will detection in detection and Panel Beneficial exceed turbine manual benefit.building relay suppression room. actions.=r CD-n, CD CD >CD> CD o M~0 C CLD-D M (0 03> CD.CD CD 0 (n;1.

5'CD CD Q)MCD 0 C D 0 0 CDD-0 0)-IO CD-n Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 179 Fire induced Possible FIRE1 $4K $7K $3K $7K $7K >$10K Expert Not Cost- Cost will LOCA reduction in Panel Beneficial exceed response CDF if benefit.procedure mitigating fire-from Alternate induced Shutdown LOCA.Panel. Judged marginal benefit due to existing design and guidance to minimize potential for inadvertent PORV interaction.

Thus, likelihood of LOCA with control room uninhabitable for a long period of time is judged low.3 0f)CD T11 CD CD>CD> CD CL X CD~0 3> CD-CD CD 0 cn ):.

3'CD CD 0)CD 0 0 M -CD 0 0 CD 0)VP Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 181 Improve relay Closed. SEISMIC01

$102K $156K $91K $146K $195K >$300K Expert Not Cost- Cost will chatter Relay chatter Panel Beneficial exceed fragility, fragility judged benefit.low contributor to CDF.Significant uncertainty in hazard and fragility not easily removed and beyond state-of-the-art as stated in IPEEE. No further actions needed.182 Improve Improve SEISMIC02

$<1K $<1K $<1K $<1K $<1K >$500K Expert Not Cost- Cost will seismic component Panel Beneficial exceed capacity of fragility and benefit.EDGs and reduce steam-driven seismic event EFW pump. contribution to CDF.184 Control/reduce Purge path is PURGE $<1K $<1K $<1K $<1K $<1K $20K Cost of Not Cost- Cost will time that the large opening. Procedure Beneficial exceed containment Reduce Change benefit.purge valves exposure time are in open of open path, position, improve reliability/avail ability of Cl, reduce Cl failure contribution to large release.0)CD-n, C,, CD CD >CD 'a> CD o0~CLD C 0 CD 0 CDW CI 0 0 CD)* a.01:> C 0 (0 CD 00 Table F.8-1 Seabrook Station Sensitivity Evaluation (Continued)

Benefit Benefit Benefit at at BE Seabrook at 7% 3% Discount Benefit SAMA Potential SAMA Discount Discount Rate of at Benefit Cost Basis for Number Improvement Discussion Case Rate Rate 8.5% 41 yrs at UB Cost Basis Evaluation Evaluation 186 Install Improve CONT01 $163K $227K $145K $204K $310K >$500K Expert Not Cost- Cost will containment containment Panel Beneficial exceed leakage reliability by benefit.monitoring reducing the system. potential for pre-existing containment leakage.187 Install RHR Reduce LOCA06 $28.OK $43K $25K $40K $53K >$100K Expert Not Cost- Cost will isolation valve ISLOCA Panel Beneficial exceed leakage challenge to benefit.monitoring RHR by system. identification of upstream valve failure.189 Modify or Allow all lof2SEPS $30K $52K $27K $52K $57K >$300K Expert Not Cost- Cost will analyze SEPS equipment to Panel Beneficial exceed capability; 1 of be run benefit.2 SEPS for following LOSP non-SI LOSP with loads, 2 of 2 EDG failure for LOSP SI but successful loads, start and load of SEPS.190 Add Eliminate NOSBO $155K $255K $138K $247K $295K $1M Expert Not Cost- Cost will synchronizatio current Panel Beneficial exceed n capability to requirement benefit.SEPS Diesel. for dead bus transfer from SEPS to normal power.'The benefits in this table are provided for 5 cases: (1) Benefit at 7% discount rate -baseline benefit calculated using nominal values for all parameters; (2) Benefit at 3% discount rate -benefit calculated using 3% discount rate rather than the nominal 7%; (3) Benefit at BE discount rate of 8.5% -benefit calculated using the best estimate discount rate provided by Seabrook Station rather than the nominal 7%; (4) Benefit at 41 yrs -benefit using a 41-year calculation period rather than the nominal 20 years; and (5) Benefit at UB -benefit calculated using the upper bound of CDF as defined by Seabrook Station rather than the point estimate for CDF.Note (1): Risk reduction not specifically evaluated because estimated cost exceeds the possible maximum averted cost-risk.

0 CD-n, CD CD >CD -> CD o =~E X (0> CD ,-CD< -CD 0 (n ;:.

Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.9 CONCLUSIONS As a result of this analysis, two SAMAs have been identified in Table F.9-1 as potentially cost beneficial (SAMAs 157 and 165), either directly or as a result of the sensitivity analyses.

These SAMA are not aging-related and are therefore not required to be resolved as part of the License Renewal effort.However, because these potential improvements could result in a reduction in public risk, these SAMAs will be entered into the Seabrook Station long-range plan development process for further consideration.

Implementation of SAMA 157 would involve the purchase of a portable 480V AC generator, installation of connections to allow use of the generator, development of a procedure for use, and training for personnel.

Implementation of SAMA 165 involves installation of a permanent hose connection on the flush flange for the RWST, development of procedures for use, and training of personnel.

None of the SAMAs identified in Table F.9-1 are aging-related.

Seabrook Station Unit 1 License Renewal Application Page F-186 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Table F.9-1: Seabrook Station Potentially Cost Beneficial SAMAs Seabrook SAMA Number Potential Improvement Discussion 157 Provide independent AC power Reduce CDF of long term SBO sequences; source for battery chargers -extend battery life to allow additional time for example: provide portable generator recovery of offsite power.to charge station battery.165 RWST fill from firewater during Could enhance long term containment containment injection

-Modify 6" injection sequences that would benefit from RWST Flush Flange to have a 21/2- RWST makeup. Installing permanent valve inch female fire hose adapter with connection would improve alignment isolation valve, efficiency.

Seabrook Station Unit 1 License Renewal Application Page F-187 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives F.10 REFERENCES

1. New Hampshire Yankee, "Individual Plant Examination Report for Seabrook Station," March 1991.2. WCAP-1 6600, Seabrook Station Probabilistic Risk Assessment:

Level 2 PRA Update, Volume 1 and 2, Revision 0, June 2006.3. New Hampshire Yankee, "Individual Plant Examination External Events Report for Seabrook Station," September 1992.4. Tetra Tech, "Calculation of Severe Accident Risks for Seabrook Station License Renewal," Revision 0, May 2009.5. Electric Power Research Institute TR-105396, "PSA Applications Guide", August 1995.6. Westinghouse WCAP-1 5603, 'WOG2000 Reactor Coolant Pump Seal Leakage Model for Westinghouse PWRs", Revision 1-A, June 2003.7. U. S. NRC NUREG/CR-5496, "Evaluation of Loss of Offsite Power Events at Nuclear Power Plants: 1980-1996", November 1998.8. U. S. NRC NUREG/CR-INEEL/EXT-04-02326, "Evaluation of Loss of Offsite Power Events at Nuclear Power Plants: 1986 -2003 (Draft)", Draft.9. U. S. NRC NUREG-1407, "Procedural and submittal Guidance for the Individual Plant Examination of external Events (IPEEE) for Severe Accident Vulnerabilities", June 1991.10. U. S. NRC Title 10 Code of Federal Regulations Part 50, Appendix R, "Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979".11. U. S. NRC NUREG/CR-2300, "PRA Procedures Guide", January 1983.12. U. S. NRC NUREG-1465, "Accident Source Terms for Light-Water Nuclear Power Plants".13. U. S. NRC NUREG/CR-6109, "The Probability of Containment Failure by Direct Containment Heating In Surry", May 1995.14. U. S. NRC NUREG/CR-6338, "Resolution of Direct Containment Heating Issue for All Westinghouse Plants with Large Dry Containments or Subatmospheric Containments", February 1996.Seabrook Station Unit 1 Page F-188 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives

15. Westinghouse WCAP-1 5955, "Steam Generator Tube Rupture PSA Notebook", December 2002.16. U. S. NRC NUREG/BR-0184, "Regulatory Analysis Technical Evaluation Handbook," 1997.17. Westinghouse WCAP-1 5603, "WOG2000 Reactor Coolant Pump Seal Leakage Model for Westinghouse PWRs", Revision 0, December 2000.18. INEEL, "Reliability Study: Westinghouse Reactor Protection System, 1984-1995," NUREG/CR-5500, Vol. 2, INEEL/EXT-97-00740, April 1999.19. U. S. NRC NUREG-1715, Volume 4, "Component Performance Study-Motor Operated Valves, 1987 -1998", September 2001.20. Nuclear Energy Institute NEI 05-01, "Severe Accident Mitigation Alternatives (SAMA) Analysis Guidance Document," November 2005.21. Office of Management and Budget, "Regulator Analysis," Circular No. A-4, September 17, 2003.22. U. S. NRC NUREG/BR-0058, Revision 4, "Regulatory Analysis Guidelines of the U. S. Nuclear Regulatory Commission," September 2004.23. U. S. NRC NUREG/CR-6613, "Code Manual for MACCS2, User's Guide," May 1998.24. U. S. NRC, Regulatory Guide 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis," Revision 1, November 2002.25. U.S. NRC NUREG/CR-6525, Revision 1, SECPOP2000:

Sector Population, Land Fraction, and Economic Estimation Program, Sandia National Laboratories, August 2003.26. Seabrook Station Radiological Emergency Plan, SSREP, Revision 56, July 2008.Seabrook Station Unit 1 Page F-189 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives APPENDIX F.A PRA CASE DESCRIPTIONS FOR SELECTED SAMA CASES Seabrook Station Unit 1 License Renewal Application Page F.A-1 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives PRA CASE DESCRIPTIONS FOR SELECTED SAMA CASES Explanation of Appendix F.A Contents This appendix describes each of the SAMA evaluation cases. An evaluation case is an evaluation of plant risk using a plant PRA model that considers implementation of the evaluated SAMA. The case-specific plant configuration is defined as the plant in its baseline configuration with the model modified to represent the plant after the implementation of a particular SAMA. As indicated in the main report, these model changes were performed in a manner expected to bound the change in risk that would actually be expected if the SAMA were implemented.

This approach was taken because the actual designs for the SAMAs have not been developed.

Each analysis case is described.

Each case includes a description of the physical change that the case represents and a description of the SAMAs that are being evaluated by this specific case.Case INSTAIR1

Description:

This case is used to determine the benefit of replacing the air compressors.

For the purposes of the analysis, a single bounding condition was performed, which assumed the station and containment instrument air systems do not fail.Case NOATWS

Description:

This case is used to determine the benefit of eliminating all Anticipated Transient without Scram (ATWS) events. For the purposes of the analysis, a single bounding analysis was performed which assumed that ATWS events do not occur.Case NOSGTR

Description:

This case is used to determine the benefit of eliminating all Steam Generator Tube Rupture (SGTR) events. This allows evaluation of various possible improvements that could reduce the risk associated with SGTR events. For the purposes of this analysis, a single bounding analysis was performed which assumed that SGTR events do not occur.Case RCPLOCA

Description:

This case is used to determine the benefit of eliminating all Reactor Coolant Pump (RCP) seal loss of coolant accident (LOCA) events.This allows evaluation of various possible improvements that could reduce the risk associated with RCP seal LOCA and other small LOCA events.Case NOLOSP

Description:

This case is used to determine the benefit of eliminating all Loss of Off-Site Power (LOSP) events, both as the initiating event and subsequent to a different initiating event. This allows evaluation of various possible improvements that could reduce the risk associated with LOSP events. For Seabrook Station Unit 1 Page F.A-2 License Renewal Application Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives the purposes of the analysis, a single bounding analysis was performed which assumed that LOSP events do not occur, both as an initiating event and subsequent to a different initiating event.Case NOSBO

Description:

This case is used to determine the benefit of eliminating all Station Blackout (SBO) events. This allows evaluation of possible improvements related to SBO sequences.

For the purpose of the analysis, a single bounding analysis is performed that assumes the emergency AC power supplies do not fail.Case NOSLB

Description:

This case is used to determine the benefit of installing secondary side guard pipes to the Main Steam Isolation Valves (MSIVs).This would prevent secondary side depressurization should a Steam Line Break (SLB) occur upstream of the MSIVs. For the purposes of the analysis, a single bounding analysis was performed which assumed that no SLB events occur (inside or outside of containment).

Case CHGO1

Description:

Assumes the charging pumps are not dependent on cooling water. This case is used to determine the benefit of removing the charging pumps dependency on cooling water.Case SWO1

Description:

Assumes the service water pumps are not dependent on DC power. This case is used to determine the benefit of enhancing the DC control power to the service water pumps.Case CCW01

Description:

This case is used to determine the benefit of improvement to the CCW system by assuming that CCW pumps do not fail.Case FW01

Description:

Eliminates loss of feedwater initiating events. This case is used to determine the benefit of improvements to the feedwater and feedwater control systems.Case LOCA01

Description:

Assumes small LOCA events do not occur. This case is used to determine the benefit of eliminating all small LOCA events.Case LOCA02

Description:

Assumes the high pressure injection system does not fail. This case is used to determine the benefit of improvements to the High Pressure Injection Systems.Seabrook Station Unit 1 License Renewal Application Page F.A-3 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Case LOCA03

Description:

Assumes failures of the low pressure injection system do not occur. This case is used to determine the benefit of improving the Low Pressure Injection Systems.Case LOCA04

Description:

This case assumes that the RWST cannot be depleted and is used to determine the impact of refilling or backup of the water supply for the RWST.Case LOCA05

Description:

Assumes that piping system LOCAs do not occur. This case is used to determine the benefit of eliminating all LOCA events related to piping failure (no change to non-piping failure is considered).

Case LOCA06

Description:

Assumes ISLOCA events do not occur. This case is used to determine the benefit of eliminating all ISLOCA events.Case CONT01

Description:

Assumes that the containment does not fail due to overpressurization.

This case is used to determine the benefit of eliminating all containment failures due to overpressurization.

Case H2BURN

Description:

Assumes hydrogen burns and detonations do not occur. This case is used to determine the benefit of eliminating all hydrogen ignition and burns.Case CONT02

Description:

Assumes there are no failures of containment isolation.

This case is used to determine the benefit of eliminating all containment isolation failures.Case CCW02

Description:

Eliminates the dependence of cooling water on the CCW heat exchangers.

This case is used to determine the benefit of alternate cooling methods to the CCW heat exchangers.

Case CST01

Description:

Assumes the CST does not run out of water and thus does not need to be refilled.

This case is used to evaluate methods of CST refill.Seabrook Station Unit 1 License Renewal Application Page F.A-4 Appendix E -Environmental Report Attachment F Severe Accident Mitigation Alternatives Case SEISMIC1

Description:

Assumes no seismic relay chatter failures occur. This case is used to evaluate the impact of improvements that would eliminate seismic relay chatter events.Case SEISMIC2

Description:

Assumes no seismic failures of diesel generators or turbine driven EFW.Case PURGE

Description:

Eliminates possibility of containment purge valves being open at the time of an event (assume purge valves always closed).Case HVAC2

Description:

Removes HVAC dependency for CS, SI, RH and CB Spray pumps.Case TDAFW

Description:

Assumes TDAFW train does not fail.Case BREAKER

Description:

Assumes no failures of 4KV bus infeed breakers.Case FIRE1

Description:

This case eliminates initiator FCRPL, control room fire-induced LOCA (PORV), to assess possible benefit of procedure enhancement for handling LOCA at RSS Panel.Case FIRE2

Description:

This case eliminates initiator FTBLP, turbine building fire at west wall or relay room, causing opening of UAT/RAT breakers and loss of power to emergency buses, to conservatively assess the benefit of installing fire detection in the Relay Room.Case INDEPAC

Description:

Benefits of independent AC power to battery chargers, applicable to SAMA 157.Case 1 of2SEPS

Description:

Benefits of SEPS success criteria change, from 2 of 2 SEPS DGs to 1 of 2 SEPS DGs, applicable to SAMA 189.Case NORMW

Description:

This PRA case assumes that RWST makeup for long term sequences without recirculation are guaranteed success.Seabrook Station Unit 1 Page F.A-5 License Renewal Application