ML20212D575

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Requests Addl Info Re Confirmatory Issue 32, Control Sys Failure Caused by Malfunction of Common Power Source on Instrument Line. Lack of Accident Analysis for Events W/One or Three Valves Malfunctioning Noted.Response Requested
ML20212D575
Person / Time
Site: Beaver Valley
Issue date: 02/27/1987
From: Tam P
Office of Nuclear Reactor Regulation
To: Carey J
DUQUESNE LIGHT CO.
References
TAC-62915, NUDOCS 8703040149
Download: ML20212D575 (2)


Text

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E $7 W Docket No. 50-412 DISTRIBUTION

_6jmN. Thompson NRC PDR P. Tam Local PDR D. Miller Mr. J. J. Carey, Senior Vice President PAD #2 Rda. ACRS (10)

Duquesne Light Company T. Novak Gray File Nuclear Group OGC-Rethesda Post Office Box 4 E. Jordan Shippingport, PA 15077 R. Grimes J. Partlow

Dear Mr. Carey:

Subject:

Beaver Valley Unit 2 - Request for Additional Information on Confirmatory Issue 3? (TAC 62915)

Ry letter dated May 28, 1986, you provided information to address the subject confirmatory issue, " Control System Failure Caused By Malfunction of Common Power Source on Instrument Line." The specific event is feedwater control valve malfunction. We were not certain if the event with one valve malfunctioning is more limiting than the event with three valves malfunctioning.

In your letter, you addressed this concern with additional information which pointed out the conservativeness of the assumed malfunction of one valve. The discussion explained that, in theory, the more uniform the cooldown caused by the inadvertent opening of the feedwater t.ontrol valves, the less the amount of reactivity inserted. The assumed failure for only one valve would cause less uniformity; therefore more reactivity is conservatively assumed to be inserted.

However, the results of the accident analysis for both cases, or similar supporting evidence, were not provided in your letter. The anticipated effects of the event on reactivity is credible, but more concrete evidence is needed to verify that the assumptions made are in fact most limiting. If this assumption has previously been found acceptable by the staff, then this information should be readily accessible to Westinghouse for use in this review. We request your response to this issue within 45 days of receipt of this letter. (Note that the nuclear plant modeled for analysis of the malfunction of all valves should also be the plant modeled for the malfunction of a single valve).

l This information request affects fewer than 10 respondents; therefore, OMB clearance is not required under PL 96-511.

Sincerely, h

A

[ Peter S. Tam, Project Manager PWR Project Directorate #2 Division of PWR Licensing-A cc: See next page

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l L . PM: PAD - P D#2 l er PTam:h I LRu enstein l 2 87 2/S/8 A 2/Q/87

, Mr. J. J. Carey Duquesne Licht Company Reaver Valley ? Power Station ec:

Gerald Charnoff, Esq. Mr. R. E. Martin, Manaaer Jay E. Silberg, Esc. Regulatory Affairs Shaw, Pittman, Potts & Trowbridae Duquesne Light Company 2300 N Street, N.W. Reaver Valley Two Project Washington, DC 20037 P. O. Rox 328 Shippingport, Pennsylvania 15077 Mr. C. W. Ewing, Ouality Assurance Zori Ferkin Manager Assistant Counsel Quality Assurance Department Governor Energy Council Duquesne Light Company 1625 N. Front Street P. O. Box 186 Harrisburg, PA 15105 Shippingport, Pennsylvania 15077 John D. Burrows, P.E.

Director, Pennsylvania Emergency Director of Utilities Managerent Agency State of Ohio Room B-151 Public Utilities Commission Transportation & Safety Building 180 East Broad Street Harrisburg, Pennsylvania 17120 Columbus, Ohio 43266-0573 Mr. T. J. Lex Rureau of Radiation Protection Westinghouse Electric Corporation PA Department of Environmental Power Systems Pesources P.-0. Box 355 ATTN: R. Janati Pittsburgh, Pennsylvania 15230 P.O. Box 2063 Harrisburo, Pennsylvania 17120 Mr. P. RaySircar Stone & Webster Engineering Corporation RYPS-2 Records Management Supervisor P. O. Rox 2325 Duquesne Light Company Boston, Massachusetts 02107 Post Office Box 4 Shippingport, Pennsylvania 15077 Mr. J. Beall tr- "S --<~wU.-S. NRC -

John A. Lee, Esq.

P. O. 181 Duquesne light Company Shippingport, Pennsylvania 15077 1 0xford Centre 301 Grant Street Mr. Thomas E. Murley, Regional Admin. Pittsburgh, Pennsylvania 15279 U. S. NRC, Region I 631 Park Avenue King of Prussia, Pennsylvania 15229

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