ML20132B642

Discusses Clarification of AP600 Dser Open Item 19.1.3.1-9. W Should Verify That PRA Models Are Representative of AP600 Design

ML20132B642
Person / Time
Site:	05200003
Issue date:	12/16/1996
From:	Joseph Sebrosky NRC (Affiliation Not Assigned)
To:	Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
References
NUDOCS 9612170324
Download: ML20132B642 (2)

Text

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4 December 16, 1996

Mr. Nicholas J. Liparulo, Manager e Nuclear Safety and Regulatory Analysis-j Nuclear and Advanced Technology Division Westinghouse Electric Corporation  ;

i P.O.-Box 355 ,

! Pittsburgh, Pennsylvania 15230 l l

4 l

SUBJECT:

CLARIFICATION OF AP600 DRAFT SAFETY EVALUATION REPORT (DSER) OPEN

} ITEM 19.1.3.1-9, WESTINGHOUSE SHOULD VERIFY THAT THE PROBABILISTIC

RISK ASSESSMENT (PRA) MODELS ARE REPRESENTATIVE OF THE AP600 DESIGN

Dear Mr. Liparulo:

l- During recent discussions concerning DSER Open Item 19.1.3.1-9 there has been

{ confusion between the staff's position and the position of Westinghouse..

t To avoid further confusion the staff wants to clarify that DSER Open i j Item'19.1.3.1-9 applies to all AP600 PRA areas (i.e., full power internal and external events and shutdown internal and external events). The staff's i review of the AP600 PRA indicated that the shutdown PRA was not updated to ,

i include risk significant design changes such as the In-containment Refueling

! Water Storage Tank squib valves. Thus, the dominant shutdown cutsets and

, shutdown importance analyses, which are necessary to derive risk results, are

outdated.

l Therefore, in order to close DSER Open Item 19.1.3.1-9 and finish the AP600 i Final Safety Evaluation Report, the staff requests Westinghouse to provide, as

! appropriate: a revised list of cutsets, a revised list of accident sequences,

revised importance analyses, and documentation clarifying other PRA informa-

, tion that has been impacted by risk significant design changes (e.g., fault

! tree data summaries). If you have any questions regarding this matter, you

] may contact me at (301) 415-1132.

1 Sincerely, original . signed b Joseph M. Sebrosky,y: Project Manager Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation Docket No.52-003 cc: See next page DISTRIBUTION:

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TKenyon BHuffman JSebrosky I DJackson JMoore, 0-15 B18 WDean, 0-17 G21 i ACRS (11) JFlack, 0-10 E4 d3  !

l 170077 DOCUMENT NAME: A:DSER PRA.CLR l Ts seceive a sepy of thle alesusnesst, na in the ben: *C* = Copy without attachrnen)4nctosure "E* = Copy w6th ettschment/ enclosure *N* = No copy )

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TR$ day 157 DATE 12/[y/96 \ 12//ff96' 12/gj/96f ae AFFICIAL RECORD COPY 9612170024 961216-

'" 8J M RE N WY

! Mr. Nicholas J. Liparulo Docket No. 52 003 Westinghouse Electric Corporation AP600 i

cc

Mr. B. A. McIntyre Mr. Ronald Simard, Director i Advanced Plant Safety & i.! censing ,

Advanced Reactor Programs  :

Westinghouse Electric Corr. oration Nuclear Energy Institute Energy Systems Business bnit 1776 Eye Street, N.W.

i P.O. Box 355 Suite 300 l Pittsburgh, PA 15230 Washington,:DC 20006-3706 1

i Mr. John C. Butler Ms. Lynn Connor Advanced Plant Safety & Licensing Doc-Search Associates Westinghouse Electric Corporation Post Office Box 34

! Energy Systems Business Unit Cabin John, MD 20818 4

Box 355

, Pittsburgh, PA 15230 Mr. James E. Quinn, Projects Manager LMR and SBWR Programs

Mr. M. D. Beaumont GE Nuclear Energy i Nuclear and Advanced Technology Division 175 Curtner Avenue, M/C 16F

Westinghouse Electric Corporation San Jose, CA 95125 4

One Montrose Metro 11921 Rockville Pike Mr. Robert H. Buchholz

, Suite 350 GE Nuclear Energy j Rockville, MD 20852 175 Curtner Avenue, MC-781 San Jose, CA 95125 i Mr. Sterling Franks U.S. Department of Energy Barton Z. Cowan, Esq.

! NE-50 Eckert Seamans Cherin & Mellott 19901 Germantown Road 600 Grant Street 42nd Floor j Germantown, MD 20874 Pittsburgh, PA 15219 l Mr. S. M. Modro Mr. Ed Rodwell, Manager '

Nuclear Systems Analysis Technologies PWR Design Certification Lockheed Idaho Technologies Company Electric Power Research Institute Post Office Box 1625 3412 Hillview Avenue Idaho Falls, ID 83415 Palo Alto, CA 94303 i Mr. Frank A. Ross Mr. Charles Thompson, Nuclear Engineer l U.S. Department of Energy, NE-42 AP600 Certification Office of LWR Safety and Technology NE-50 19901 Germantown Road 19901 Germantown Road Germantown, MD 20874 Germantown, MD 20874