ML071940128
| ML071940128 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/12/2007 |
| From: | Howe A NRC/NRR/ADES/DRA/PRALB |
| To: | Geoffrey Miller Dominion |
| Lingam, Siva NRR/DORL 415-1564 | |
| References | |
| TAC MD4622, TAC MD4623 | |
| Download: ML071940128 (4) | |
Text
From:
Andrew Howe To:
gary.D.Miller@Dom.com Date: 7/12/2007 2:36:52 PM
Subject:
Re: SURRY RAI RESPONSE Gary - I am only asking for a response to the one (latest) question, which effectively combines a and f. Given what was said in the call regarding conservatisms in the control room evacuation assumptions, I do not need details about the methods of shutting down the plant remotely.
Questions b, c, d, and e are therefore not needed for my safety evaluation. Hopefully, this simplifies things.
Andrew J Howe USNRC - Office of Nuclear Reactor Regulation Division of Risk Assessment 301-415-3078
>>> <Gary.D.Miller@dom.com> 7/12/2007 1:46 PM >>>
At the risk of beating a dead horse (and in licensing there is no horse so dead that you can't beat it some more), I was a little bit confused by Andrew's comment below. Is it Andrew's expectation that we respond to previously provided questions a and f and the additional RAI question (three responses)? The reason I ask is that Andrew mentions "b through e" as not needing to be answered and then states that questions "a through e" can be replaced by the new question, thus requiring a response to only the new question and the previous question f (two responses)? Also, it appears that the new question would effectively address all of the previous a-f questions.
I realize that I am probably overthinking this; however, three us have read the email and each of us has come to a different conclusion as to what should be included in our RAI response. Just want to make sure that we are providing the right information to Andrew.
PLEASE NOTE NEW EMAIL ADDRESS: Gary.D.Miller@dom.com Gary D. Miller Nuclear Licensing and Operations Support Dominion Resources Services, Inc.
(804) 273-2771 or tie-line 730-2771 fax 804-273-3715 "Siva Lingam"
<SPL@nrc.gov>
To 07/12/2007 11:29 <gary.D.Miller@Dom.com>
AM cc "Andrew Howe" <AJH1@nrc.gov>
Subject Re: SURRY RAI RESPONSE Please note the Andrew's comments/suggestions when you are providing responses.
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 7/12/2007 10:45 AM >>>
Considering what was said in the call, I think a limited response may be more appropriate. If the licensee responded to questions a and f, on why the PRA model is conservative by assuming control room abandonment (i.e., actual expected temperatures and equipment qualification, procedures for use of alternate cooling at lower temperatures, availability of backup chillers not credited in the PRA), then responses to b - e would not be necessary to support the SE. I would propose the formal additional RAI to replace questions a - e:
The licensee's PRA model assumes that for a loss of MCR cooling, the MCR would be abandonned and the plant would be shut down from the ASP.
The licensee should describe why this PRA assumption is conservative, addressing the anticipated temperature transient in the control room, equipment qualification of the MCR components, and the availability and procedural controls for alternate cooling capabilities not assumed to be used in the PRA.
Andrew J Howe USNRC - Office of Nuclear Reactor Regulation Division of Risk Assessment 301-415-3078
>>> Siva Lingam 7/3/2007 1:45 PM >>>
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 CONFIDENTIALITY NOTICE: This electronic message contains information which may be legally confidential and/or privileged and does not in any case represent a firm ENERGY COMMODITY bid or offer relating thereto which binds the sender without an additional express written confirmation to that effect. The information is intended solely for the individual or entity named above and access by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you.
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Re: SURRY RAI RESPONSE Creation Date 7/12/2007 2:36:44 PM From:
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