ML19209B592

Forwards Evaluation of Potentially Adverse Environ Effects on Nonsafety-Grade Control Sys, in Response to NRC 790917 Request

ML19209B592
Person / Time
Site:	Davis Besse
Issue date:	10/05/1979
From:	Roe L TOLEDO EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML19209B593	List: ML19209B592 ML19209B606
References
542, NUDOCS 7910100201
Download: ML19209B592 (2)

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. TOLEDO EDISON LOWELL E. ROE Vice Pres.cer,t 5.c.w.. o...<or.m Docket No. 50-346 '*"" 2585888 Operating Licensc No. NPF-3 Serial No. 542 october 5, 1979

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Mr. liarold R. Denton, Director

, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Denton:

This letter is in response to your September 17, 1979 letter on the

" Potential Unreviewed Safety Question on Interaction Between Non-Safety Grade Systems and Safety Grade Systems" for the Davis-Besse Nuclear Power Station, Unit No. 1 (DB-1). 'unis subject was further addressed in IE Information Notice 79-22, issued September 14, 1979.

Within the time frame allowed by your letter, our efforts have been focused on developing an understanding of the issue and making a preliminary assess-ment of the impact of this issue on the conclusions of the accident analyses presented in the DB-1 Final Safety Analysis Report. These are identified in Table II. In review of each accident analysis case, no adverse interaction was identified that would have extended the consequences beyond those already evaluated. The report of this evaluation is attached.

Arcas dealing with non-safety grade instrumentation and facility operator interfaces are not addressed due to the time constraints of the request.

These areas are not directly involved in the mitigation of the DB-1 licensi>g basis accidents. We, the re fo re , intend to evaluate these related' areas in more comprehensive programs already underway as a result of activities related to the NUREG 0578, "TMI-2 Lessons Learned Task Force Status Report and Short-Term Recommendations."

We believe the attached report is adequate for your agaff to determine that the DB-1 operating license, NPF-3, need not be m'odified, suspended or revoked.

Ve ry ruly yours,

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Enclosure .

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THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OH:0 43652

SUBMITTAL IN RESPONSE TO A 10 CFR 50.54(f)

REQUEST OF SEPTEMBER 17, 1979 FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 FACILITY OPERATING LICENSE NO. NPF-3 This letter is aubmitted in conformance with 10 CFR 50.54(f) relating to :1r. II. Denton's letter of September 17, 1979. This deals with

" Potential Unreviewed Safety Question on Interaction Between Non-Safety Grade Systems and Safety Grade Systems."

r' Vice President, Facilitics Development s

Sworn to and subscribed before me the fif th day of October,1979.

u,n k :u 4fA~ f ANNA MAE FERGG'ON

, Notary Public - State of Ohio My Commission Empires Oct. 7.1981 1

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