ML20148H150

Forwards Technical Position Re Capability of Current Design of AP600 to Achieve Safe Shutdown Following Fire in Any One Fire Area

ML20148H150
Person / Time
Site:	05200003
Issue date:	06/06/1997
From:	Slosson M NRC (Affiliation Not Assigned)
To:	Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
References
SECY-94-084-C, SECY-94-84-C, NUDOCS 9706090249
Download: ML20148H150 (4)

Text

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. June 6, 1997 Mr. Nicholas J. Liparulo, Manager Nuclear Safety and Regulatory Analysis Nuclear and Advanced Technology Division Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230

SUBJECT:

FIRE PROTECTION POSITIONS RELATED TO THE AP600 REACTOR DESIGN

Dear Mr. Liparulo:

In a letter dated December 6,1996, the Nuclear Regulatory Commission (NRC) sent you a list of potential critical path issues in the design certification process for the AP600. One of the issues, Key Issue #12, involves the ecceptability of the Westinghouse approach for fire protection. On the basis of its review of the standard safety analysis report, the staff has developed its technical position regarding the capability of the current design of the AP600 to achieve safe shutdown following a fire in any one fire area. In a letter dated May 9, 1997, Westinghouse, the applicant, provided its interpre-tation of the post-fire safe shutdown conditions that are applicable to the AP600. Inthisinterpretation,whichisbasedprimarilyonSECY-94-084,the applicant states that the safe stable condition of 420 F is equivalent to cold shutdown for the purpose of compliance with 10 CFR 50.48, Fire Protec-tion. As described below, and in the enclosed technical position, this Westinghouse interpretation is not consistent with the staff position for post-fire safe shutdown capability. Specifically, the staff position, is that j safe shutdown for fire incidents applies to both hot and cold shatdown i functions consistent with the definition prescribed in Appendix !! to 10 CFR Part 50.

The staff discussed this position with the applicant during the meeting on May 19, 1997. If the staff develops additional fire protection issues, it will discuss them with the applicant and will prepare additional technical positions, as needed. If you have any questions regarding this matter, you may contact Diane Jackson at (301) 415-8548.

Sincerely, original signed by:

Marylee M. Slosson, Director Docket No.52-003 Division of Reactor Program Management Office of Nuclear Reactor Regulation g) lo

Enclosure:

As stated t cc w/ enclosure: See next page I

!S1!00 NRC FRE CENTEfi COPY DOCUMENT NAME: A: KEY #12 2.LET *See previous concurrence T. em. e copy of thle document,Indicateln the box: *C" ^C ^y i^utQt24 attachment / enclosure *E" = Copy with attachment / enclosure "N" = No copy OFFICE PM:PDST:DRPM D:PDST:DRPM (A):DRPM l l NAME DTJackson:sg* TRQuay* MMSlosson H DATE 06/03/97 06/03/97 06/r/97 0FFICIAL RECORD COPY 9706090249 970606 d ff PDR ADOCK 05200003 E PDR (1l V

• -, i l -DJ11RIBUTION: Letter to Mr. Nicholas J. Liparulo. Dated: ;1ono 6. 1997 l Docket File i PUBLIC-l PDST R/F' l MSlosson SWeiss TQuay 1

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'JHolmes, 0-8 D1 HWalker, 0-8 D1 CLi, 0-8 D1 BThomas, 0-8 D1 l

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s l Mr. Nicholas J. Liparulo Docket No.52-003 Westinghouse Electric Corporation l AP600  ;

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cc: Mr. B. A. McIqtyre Mr. Ronald Simard, Director j

Advanced Pltat' Safety & Licensing  !

Advanced Reactor Programs Westinghouse Electric Corporation Nuclear Energy Institute Energy Systems Business Unit 1776 Eye Street, N.W.

l P.O. Box 355 Suite 300 Pittsburgh, PA 15230 Washington, DC 20006-3706 l i Mr. Cindy L. Haag Ms. Lynn Connor Advanced Plant Safety & Licensing j Doc-Search Associates Westinghouse Electric Corporation Post Office Box 34 Energy Systems Business Unit  !

i Cabin John, MD 20818 l l Box 355 i

l Pittsburgh, PA 15230 Mr. James E. Quinn, Projects Manager LMR and SBWR Programs i Mr. S. M. Modro GE Nuclear Energy  !

Nuclear Systems Analysis Technologies 175 Curtner Avenue, M/C 165 l l Lockheed Idaho Technologies Company San Jose, CA 95125 i Post Office Box 1625 Idaho Falls, ID 83415 Mr. Robert H. Buchholz '

GE Nuclear Energy Mr. Sterling Franks 175 Curtner Avenue, MC-781 U.S. Department of Energy San Jose, CA 95125 NE-50 19901 Germantown Road Barton Z. Cowan, Esq.

Germantown, MD 20874 Eckert Seamans Cherin & Mellott 600 Grant Street 42nd Floor Mr. Frank A. Ross Pittsburgh, PA 15219 i U.S. Department of Energy, NE-42 i Office of LWR Safety and Technology Mr. Ed Rodwell, Manager 19901 Germantown Road PWR Design Certification Germantown, MD 20874 Electric Power Research Institute <

3412 Hillview Avenue i Mr. Charles Thompson, Nuclear Engineer Palo Alto, CA 94303 1 AP600 Certification NE-50 19901 Germantown Road .

Germantown, MD 20874 I

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TECHNICAL POSITION 3 BY THE OFFICE OF NUCLEAR REACTOR REGULATION  !

PLANT SYSTEMS BRANCH l' DIVISION OF SYSTEMS SAFETY AND ANALYSIS FIRE PROTECTION ISSUES RELATED TO THE DESIGN OF THE WESTINGHOUSE AP500 ADVANCED LIGHT WATER REACTOR The fire protection review criteria provided-in SECY-90-016, dated January 12, ,

1990, and approved by the Cone,ission in a staff requirements memorandum (SRM) i dated June 26, 1990, specifies that advanced light water reactors (ALWR) shall >

provide an enhanced level of fire protection over existing reactors, to ensure ,

that safe shutdown can be achieved assuming that all equipment in any one fire i area-is rendered inoperative due to fire damage, and that re-entry into the fire area by plant personnel for repairs or operator actions is not possible.

SECY-90-016 does not define the term safe shutdown. Appendix R to 10 CFR Part 50 defines safe shutdown as applying to both hot and cold shutdown )

functions. t SECY-94-084, dated March 28, 1994, and approved by the Commission in an SRM dated June 30, 1994, allowed the 420 'F criteria, proposed by the Electric -

' Power Research Institute, rather than cold shutdown, specified in Regulatory Guide 1.139, " Guidance for Residual Heat Removal," as a safe stable condition, which the passive decay heat removal systems must be capable of. achieving and maintaining following non-LOCA events. Fire incidents are not classified as '

design basis-events, such that the single failure criteria specified in j Appendix A to 10 CFR Part 50 would apply. SECY-94-084 mentions that the term 3 safe shutdown is used throughout Appendix R to 10 CFR Part 50, and that it '

applies to both hot and cold shutdown. However, this information, based on i discussions with the authors of the SECY, was intended as historical informa- I tion only, to demonstrate that NRC regulations have several definitions for safe shutdown. This discussion was not intended to permit the 420 *F safe

' stable condition for meeting the safe shutdown criteria specified in SECY-90-016 for fire incidents.

The current design of the AP600 relies solely on the passive safety related systems to achieve safe shutdown following a fire'in any one fire area. These safety related systems are not capable of achieving cold shutdown conditions.

The non-safety systems are required to achieve cold shutdown. However, the non-safety related systems have not been provided with adequate fire protec-tion such that the criteria specified in SECY-90-016, for fire incidents has been achieved. Therefore, the current design of the AP600 does not meet the fire protection criteria for safe shutdown as prescribed in SECY-90-016.

Enclosure  !

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