ML20209D286

Forwards Site Analysis Branch Comments on Probabilistic Safety Assessment (PLG-0300) Sections 9.3 Re Aircraft Crash Analysis & 9.7 Re Hazardous Chemicals & Transportation Events.Sections Acceptable

ML20209D286
Person / Time
Site:	Seabrook
Issue date:	08/30/1984
From:	Vollmer R Office of Nuclear Reactor Regulation
To:	Speis T Office of Nuclear Reactor Regulation
Shared Package
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References
FOIA-87-6 NUDOCS 8409050138
Download: ML20209D286 (2)

Text

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UNITED STATES cM "'%

NUCLEAR HEGULATORY COMMisslON

'g WASHINGTON, D.C. 20555

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% ,,,,,+ AUS 3 01984 Docket Nos.: 50-443/444 -

MEMORAND P FOR: Themis P. Speis, Dire'ctor Division of Safety Technology FROM:

Richard H. Vollmer, Director Division of Engineering

SUBJECT:

EXTERNAL EVENTS PROBABILISTIC SAFETY ASSESSMENT (PSA)

REVIEW FOR SEABROOK UNITS 1 AND 2 Plant Name: Seabrook Units 1 and 2 Licensing Stage: OL ,

Docket Nos.: 50-443/444 Responsible Branch: Geosciences Branch: P. Sobel Site Analysis Branch Reviewer: C. Ferrell Requested Completion Date: August 15, 1984 Review Status: PRA Review Complete Attached, as requested, are the Site Analysis Branch comments on Sections 9.3, Aircraft Crash Analysis and 9.7, Hazardous Chemicals and Transportation Events of the Seabrook Station Probabilistic Safety Assessment, Main Report No. PLG-0300, dated December 1983.

These sections were evaluated by C. Ferrell, Site Analyst, Site Analysis Branch.

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Richard H. Vollmer, Director Division of Fagineering

Attachment:

As stated Fo1 A c M Bjg 24hk5f/3fle2p] f M _

SAB Comments on Seabrook Units 1 and 2 PSA Section 9.3 Aircraft Crash Analysis This analysis is similar to the applicant's previous risk analysis evaluation presented in the FSAR and evaluated by the NRC staff in Section 2.2 of the Seabrook SER (NUREG-08%). Both of these analyses conclude that aircraft crash risk as the result of activities in the vicinity of the Seabrook site is acceptably low and does not pose a threat to the safe operation of the plant.

We have reviewed Section 9.3 of the PSA and find it acceptable.

Section 9.7 Hazardous Chemicals and Transportation Events In Section 9.7 the applicant noted that the probability of a nonrecoverable loss of offsite power due to a truck accident (i.e., a truck penetrattmNi bridge guard rail and damaging the buses for all offsite power) s 2.76 X 10~4 er yer .

We have reviewed the applicant's analysis of the postulate uc accidents and find it to be acceptable.

According to the applicant's analysis of loss of onsite power, the unavailabilit "

of all onsite AC buses is 7.7 X 10~3 Hence the estimated probability of nonrecoverable loss of all AC power (offsite and onsite) is about 2 X 10-6 per year. )

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