ML041000405

Response to Request for Additional Information Regarding License Amendment Request 03-01.

ML041000405
Person / Time
Site:	Seabrook
Issue date:	03/25/2004
From:	Warner M Florida Power & Light Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NYN-04027
Download: ML041000405 (5)

Text

FPLEnergy FPL Energy Seabrook Station Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7000 MAR 2 5 2004 Docket No. 50-443 NYN-04027 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001

Reference:

1. FPLE Seabrook Letter NYN-03069, Seabrook Station License Amendment Request 03-0l,"Changes to Electrical Power Systems - A.C. Sources Technical Specifications - Inclusion of the Supplemental Emergency Power System," dated August 25, 2003.

2. FPLE Seabrook Letter NYN-04005, "Response to Request for Additional Information Regarding License Amendment Request 03-01," dated February 9, 2004.

Seabrook Station "Response to Request for Additional Information Regarding License Amendment Request 03-01 "

FPL Energy Seabrook, LLC (FPLE Seabrook) has enclosed herein its response to a request for additional information associated with License Amendment Request (LAR) 03-01. The additional information requested by the NRC is associated with FPLE Seabrook's planned installation of a permanent non safety-related supplemental emergency power system (SEPS).

Should you have any questions concerning this response, please contact Mr. James M. Peschel, Regulatory Programs Manager, at (603) 773-7194.

Very truly yours, FPL ENERGY SEABROOK, LLC Mark E. Warner Site Vice President PRO (

U. S. Nuclear Regulatory Commission NYN-04027IPage 2 Cc: H. J. Miller, NRC Region I Administrator V. Nerses, NRC Project Manager, Project Directorate I-2 G. T. Dentel, NRC Senior Resident Inspector Mr. Bruce Cheney, Director New Hampshire Office of Emergency Management State Office Park South 107 Pleasant Street Concord, NH 03301 OATH AND AFFIRMATION I, Mark E. Warner, Site Vice President of FPL Energy Seabrook, LLC, hereby affirm that the information and statements contained within this response to the Request for Additional Information to License Amendment Request 03-01 are based on facts and circumstances which are true and accurate to the best of my knowledge and belief Sworn and Subscribed before me this

,9Sday of Al ,2004 F. teY41a

&~Z~ Notir Public Mark E. Warner Site Vice President

Enclosure to NYN-04027 Response to Request for Additional Information Seabrook Station, Unit No. 1 (TAC NO. MC0635) 1 What is the "at power, 14 day Allowed Outage Time" Incremental Conditional Core Damage Probability and Incremental Conditional Large Early Release Probability for the configuration of two Emergency Diesel Generators (EDGs) and one Supplemental Emergency Power Supply diesel, and then having one of the EDGs become inoperable?

Response

The at power, internal events Incremental Conditional Core Damage Probability (ICCDP) for the 14 day AOT case (One EDG and SEPS diesels available, one EDG unavailable) is 5.76 e-7. The at power, internal events Incremental Conditional Large Early Release Probability (ICLERP) for the 14-day AOT case is 1.29e-9. These results were produced using a le-14 truncation level.

The small increase in ICCDP is generally offset by an approximate 3.2 e-7 decrease in ICCDP at shutdown since routine EDG maintenance will not be performed during refueling outages if a 14 day AOT is granted. The very low ICLERP is expected since Large Early Release Fraction (LERF) at Seabrook is dominated by containment bypass events, and not strongly influenced by AC power availability.

The addition of the Supplemental Emergency Power Supply (SEPS) diesels results in an approximate 30% overall decrease in core damage frequency.

2 Specifically list all external events included in the Probability Risk Assessment (PRA).

Response

The full power portion of the Seabrook Station integrated PRA model is a full scope level 2 model. External events are evaluated through the probabilistic modeling (i.e. fire PRA, seismic PRA, etc). There are a total of 32 specific external initiating events included in the Seabrook PRA model. These individual initiating events are grouped into the following categories:

• Internal Fires

• Seismic Events

• External Flooding

• Transportation / Chemical

• Aircraft Crash (Screened out)

• High Winds/Tornado (Screened out)

• Turbine Missile Impacts (Screened out)

Note: Weather related loss of offsite power is grouped w/ Internal Initiating events.

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3 How do you plan to resolve the 5 remaining PRA significant comments from the October 1999 Peer review.

Response

FPLE Seabrook plans to resolve these comments, as suggested by the peer reviewers, by 2007.

None of the peer review comment resolutions are expected to affect the results of the SEPS license amendment since any modeling changes would equally affect both the base model and the AOT change case.

4 What in this license amendment request does the Maximum Ice Loading of 1-inch radial reference?

Response

This condition was included in the specification for the SEPS equipment. It applies to overhead electrical distribution wiring. However, based on the final design of SEPS it is not applicable since there is no overhead wiring.

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