ML20069E691

Responds to NRC Requesting Response to Questions Re Pratt Butterfly Valves Used to Purge or Vent Containment. Mechanical Restrictions Installed to Limit Valve Opening to 55 Degrees in One Train & 65 Degrees in Second Train

ML20069E691
Person / Time
Site:	Davis Besse
Issue date:	03/16/1983
From:	Crouse R TOLEDO EDISON CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
920, NUDOCS 8303220155
Download: ML20069E691 (3)

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TOLEDD

%mer EDISON Rm R cm Docket No. 50-346 va p,s.on sama

<4tm asa s221 License No. NPF-3 Serial No. 920 March 16, 1983 Director of Nuclect Reactor Regulation Attention: Mr. John F. Stolz Operating Reactor Branch No. 4 Division of Operating Reactors United States Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Stolz:

This is in response to your letter dated February 16, 1983 (Log No.

1217). In that letter you requested that Toledo Edison provide a response to two questions pertaining to Pratt butterfly valves used to purge or vent the Davis-Besse Nuclear Power Station Unit No. 1 containment. Toledo Edison's response is as follows:

1. Your assessment of the operability of your large-diameter Pratt purge and vent valves in light of the concerns outlined in Enclosure 1.

RESPONSE: Toledo Edison has installed mechnical restrictions to limit valve opening to 55' in one train of our containment purge and vent system and 65* in the second train. The discrepancy is a result of the uncertainty that exists as to the ability of the valves to close under certain LOCA conditions. Toledo Edison will continue attempts to resolve this uncertainty but in the interim, we will continue to keep these valves closed with control power off.

2. Whether or not you intend tc maintain the purge and vent valves sealed closed in accordance with Standard Review Plan Section 6.2.4, II.6.f and to veriff them to be closed every 31 days whenever the reactor is not in the cold shutdown or refueling mode until such time as you submit acceptable information that demonstrates that your large-diameter Pratt purge / vent valves will operate in the event of a DBA-LOCA.

Dl 8303220155 830316 PDR ADOCK 05000346 P PDR THE TOLEDO EDISON COMPANY EDISON PLAZA 303 MADISON AVENUE TOLEDO, OHIO 43652

Dockst Ns. 50-346 Lictnsa Ns. NPF-3 Serial No. 920 March 16, 1983 Page 2 RESPONSE: The purge and vent valves at Davis-Besse (CV 5005, CV 5006, CV 5007 CV 5008) are currently closed and with control power off. Their position is verified once per each shift.

Very truly yours, RPC:RFP:lah ac: DB-) NRC Resident Inspector l

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S 10 CFR 50.54(f)

SUBMITTAL IN RESPONSE FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT NO. 1 FACILITY OPERATING LICENSE NO. NPF-3 This letter is submitted in conformance with 10 CFR 50.54(f) in response to Mr. John F. Stolz'c letter of February 16, 1983 (Log No. 1217). This deals with completing of valve operability reviews for large Pratt Butter-fly valves used for purge or vent of containment -- Davis-Besse, Unit 1.

By / -

Vice President, Nuclear Sworn to and subscribed before me this 17th day of March, 1983.

/ { (A M2w Notpty Public NORA LYNN FLOOD Notary PuWic, State of Ohio My Commission Empires Sept.1,1987

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