ML20027B965
| ML20027B965 | |
| Person / Time | |
|---|---|
| Issue date: | 09/23/1982 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| Shared Package | |
| ML20027B966 | List: |
| References | |
| NUDOCS 8210120049 | |
| Download: ML20027B965 (4) | |
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M~ 3 ofb September 23, 1982 MEMORAfiDUM FOR: Victor Stello, Jr.
Deputy Executive Director Regional Operations and Generic Requirenents FROM:
Harold R. Denton Directer Office of f;uclear Reactor Regulation
SUBJECT:
STAfiDBY SHUTDOWN FACILITIES (SSF)
A neeting was held on August 31, 1982 between nenbers of our staffs to discuss the concerns in your August 19, 1982 memorandum to ne that the staff appears to be changing the design requirements for the Oconee SSF with regard to Appendix R.
He have enclosed specific NRR staff connents to the issues raised in your neno-randun.
It was aareed that a CRGR briefing nay not be necessary to resolve your concerns, pendiig your review of the response.
The Oconee SSF was reviewed for confomance to Appendix R; and for conformance to Duke Power Company's safe shutdown criteria for the SSF. A postulated safe shutdown earthquake at Oconee could cause failure of the condenser circulating water system, flooding the Turbine Building and the energency feedwater systen.
Duke Power's seismic criteria for the SSF was to pernit the auxiliary service water systen in the SSF to backup the existing energency feedwater systen for the postulated seismic event.
We expect that the licensee's response due in mid-September 1982 will also reflect the licensee's views regarding sone of the information requested.
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MEMORANDU!i FOR: Victor Stello, Jr.
Deputy Executive Director Regional Operations and Generic Requirenents FROM:
Harold R. Denton, Director Office of Nuclear Reactor Regulation SUSJECT:
STANDBY SHUTDOWN FACILITIES (SSF)
A neeting was held on Auqust 31, 1982 between nenbers of our staffs to discuss the concerns in your August 19, 1982 menorandun to me that the staff appears to be changing the design requirements for the Oconee SSF with regard to Appendix R.
We have enclosed specific NRR staff connents to the issues raised in your neno-randun.
It was agreed that a CRGR briefing nay not be necessary to resolve your concerns, pending your review of the response.
The Oconee SSF was reviewed for confomance to Appendix R; and for confomance to Duke Power Company's safe shutdown criteria for the SSF. A posuloted safe shut 10wn earthquake at Oconee could cause failure of the condenser circulating water systen, flooding the Turbine Building and the energency feedwater systen.
Duke Power's seismic criteria for the SSF was to pemit the auxiliary service water system in the SSF to backup the existing energency feedwater systen far the postulated seisnic event.
We expect that the licensee's response due in nid-September 1982 will also reflect the licensee's views regardinq sone of the infomation requested. We will be happy to neet with you at a CRGR briefing to provide any additional clarification you may require.
Haroid R. Denton, Director Office of Nuclear Reactor Ret;ulation
Enclosure:
Specific Conmnts DISTRIBUTION LRubenstein Docket File w/inc. PWagner w/inc.
SHanauer Glainas NRC PDR RIngram RMattson Program Support Br. NRR-82-350 L PDR MStine w/ ticket RVollmer Yellow ticket file w/inc. Rm 416 DEisenhut Gray File HThompson RPurple ECase PCheck JHeltemes HDenton BSnyder
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l-SPECIFIC COMMENTS OF STELLO'S LETTER OF AUGUST 19, 1982 i
Comment'1 The staff appears to be interpreting Appendix R in a way that will require l
i tne Oconee Plant to be upgraded to cope with excessive cooldown events from I
secondary system depressurization and with events involving excess loss of coolant from the primary system.
Response
The staff is' applying theire'quirements of Appendlic R in' reviewing the I
adequacy of the Oconee SSF with regard to fire events. Appendix R provides l
t for separation and isolation requirements for circuits (including associated circuits) that could prevent operation or cause maloperation due to fire j
induced hot shorts, open circuits or shorts to ground. This review by the i
licensee and the staff is designed to assure.that spurious operation of valves l
and other components will not jeopardize the ability to achieve and maintain hot shutdown.
l In the case of Oconee's SSF our intent is to assure that spurious valve opera-
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tions which could lead to excessive cooldown or heatup of the primary system j
are prevented. It is unfortunate that the wording of our concern as expressed i
in Reference 1 was not clear. We are not attempting to influence the licensee l
I into putting in a large make-up pump, but instead trying to assure that spurious valve operation would not create a demand for a larger primary system makeup than that which could be supplied by the. installed make-up pump.
i Comment 2 Reference 1 also poses additional requirements for SSF instrumentation and h
requiremants for coping with other potential safety challenges such as sabotage, earthquake and f1oods.
Response
The licensee's conceptual design submittal letter dated February 1,1978 states that "...the Safe Shutdown Systems will augment e.tisting station capabilities relative to mitigating postulated occurrences such as fires, security incidents l
and Turbine Building flooding."
i The design to account for the challenges you cite stein from the licensee's The need design basis for the facility and not an NRC add-on requirement.
l to consider earthquake effects is mandated by Turbine Building flooding considerations since the failure of a condenser circulating water system l
which is not seismically designed, could jeopardize plant safety.
By letter 28, 1980, Duke Power Company submitted a final design package dated March entitled, " Duke Power Company, Oconee Nuclear Station, Information in Support of Standby Shutdown Facility." This document provides for the SSF to meet the Safe Shutdown Earthquake. The add-on instrumentation requested in Reference 1 is to provide a facility meeting the requirements of Appendix R.
The same instrumentation is being requested of all licensed facilities.
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2 Comment 3 Add-on feature of the right kind could result in safety benefits by covering a spectrum of safety threats; however, the cost of such add-on SSF features can be very large if the staff does not settle on' design and performance criteria prior to their design and installation.
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Response
We agree that add-on features of the right kind could result in additional i
safety benefits covering a spectrum of safety threats and that use of the results of ongoing studies such as the work under USI A-45 Task Action Plan could be useful in establishing performance criteria for add-on featurr:.
However, until this work is complete we will cuntinue to apply Appendix R as the base criteria for dedicated shutdown facilities with supplementary criteria proposed by the licensee to account for plant specific threats such as Turbine Building flooding.
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