ML071840387

MCR and ESGR Chilled Water Piping Replacement (Risk Assessment RAI)

ML071840387
Person / Time
Site:	Surry
Issue date:	07/03/2007
From:	Siva Lingam NRC/NRR/ADRO/DORL/LPLII-1
To:	Geoffrey Miller Dominion
Lingam, Siva NRR/DORL 415-1564
References
TAC MD4622, TAC MD4623
Download: ML071840387 (2)

Text

From:

Siva Lingam To:

gary.D.Miller@Dom.com Date:

7/3/2007 1:45:17 PM

Subject:

Re: SURRY RAI RESPONSE Attached please find additional RAIs Andrew wants to discuss with a conference call. Please give me a call.

Siva P. Lingam Project Manager (NRR/DORL/LPL2-1)

Surry Nuclear Station Location: O8-D5 Mail Stop: O8-G9 Telephone: 301-415-1564 Fax: 301-415-1222 E-mail address: spl@nrc.gov

>>> Andrew Howe 7/3/2007 1:37 PM >>>

I have reviewed Surry's 6/28 response to APLA's RAI. Some additional clarifications are still required, and perhaps a phone call might be appropriate:

6/5/07 RAI a - Is control room abandonment for high temperature conditions proceduralized and trained, and what is the cue(s) for abandonment? Is the control room equipment qualified up to the temperature at which abandonment occurs, or are equipment failures possible due to high temperatures prior to abandonment?

b - Why is RCP seal integrity not a requirement for a remote safe shutdown?

c - Is a long term AFW supply available to maintain hot standby conditions without transition to cold shutdown and RHR cooling?

d - What is changed in the ESGRs such that less cooling is required depending upon the control staff location?

e - What probability is used for successful transfer to the ASP, and what is the basis for that probability?

f - Would the nonsafety chillers in fact be available and used rather than control room abandonment (i.e., is this a conservative assumption, or does it reflect actual plant limitations)?

Andrew J Howe USNRC - Office of Nuclear Reactor Regulation Division of Risk Assessment 301-415-3078 CC:

Andrew Howe

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Re: SURRY RAI RESPONSE Creation Date 7/3/2007 1:45:17 PM From:

Siva Lingam Created By:

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