ML19270G916

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Forwards Rept on Reanalysis of Safety-Related Piping Sys. Requests Mod of 790313 Order for Shutdown to Permit Operation Until Refueling.Certificate of Svc Encl
ML19270G916
Person / Time
Site: Beaver Valley
Issue date: 06/19/1979
From: Dunn C
DUQUESNE LIGHT CO.
To: Harold Denton, Schwencer A
Office of Nuclear Reactor Regulation
Shared Package
ML19270G917 List:
References
NUDOCS 7906210131
Download: ML19270G916 (3)


Text

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435 Sixth Avenue Fittsburgh, Pennsylvania 15219 June 19, 1979 Mr. liarold R. Denton Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Attention: A. Schwencer, Chief Operating Reactors Branch No.1 Division of Operating Reactors Washington, D.C. 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334 Request to Modify the Commission's March 13, 1979

" Order to Show Cause" Gentlemen:

Enclosed are three (3) signed originals and thirty-seven (37) copies of a " Report on the Reanalysis of Safety Related Piping Systems for Beaver Valley No. 1 Unit". Included with this report are the responses to the staff's formal requests for additional information as well as the responses to the questions raised during the staff's review of the reanalysis conducted at the offices of the Stone & Webster Engineering Corporation during the week of June 4, 1979.

The report updates the status of the analysis ef fort as reported to you in Mr. Woolever's letter of Jane 11, 1979, and provides a summary of the results of the reanalysis of safety related piping at Beaver Valley that have _bcen performed to date.

Within the next two weeks, as described in the report, a total of six piping supports will be modified and two new supports, consisting of a total of three snubbers, will be installed. The completion of these modifi-cations will assure that the occurrence of the safe shutdown earthquake for Beaver Valley Unit 1 will not result in seismic loads on piping systems which will impair the functional capability of engineered safety features or the emergency core cooling systems, or prevent the maintenance of safe shutdown conditions or result in irreparable damage to systems required to bring the plant to a cold shutdown condition.

We therefore request that so much of the Commission's March 13, 1979 Order which requires the plant to remain in a shutdown condition be modified at this time to permit interim operation of the unit until the time for refueling. We estimate that the reactor will be ready for refueling af ter operation for a period of six to seven weeks following startup.

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Beaver Valley Power Station, Unit No. 1 Docket No. 50-334 Request to Modify the Commission's March 13, 1979

" Order to Show Cause" Page During the first refueling outage, additional modifications will be made to approximately two dozen pipe supports for the component cooling water system, as well as to any other pipe supports that might require modification to prevent the occurrence of stress conditions on some supports that could necessitate a plant shutdown subsequent to the occurrence of a seismic event of a severity less than the magnitude of the Operational Basis Earthquake for which the plant is presently licensed.

The balance of the current reanalysis effort will continue during this interim operation in order to identify required modifications for the remaining piping systems analyzed with Shock II--i.e. , those piping systems which are not required for safe shutdown capability or not associated with the engineered safety features or the emergency core cooling systems--

and any additional modifications will be completed during the second refueling period.

Very truly yours, C. N. Dunn Vice President, Operations Enclosure 2246 152 0

(CORPORATE SEAL)

Attest:

l WQ H.W. Staas Secretary COMMONWEALTH OF PENNSYLVANIA)

) SS:

COUNTY OF ALLEGENY )

On this /9'* day of E'di , 1979, before me, LONAT.D W. SHANNON , a Notary Public in and for said Common-wealth and County, personally appeared C. N. Dunn, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.

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n' T:! IIEm DONALD W. SHANNCN. NOTARY PUEll?

PITTSBURCH, ALLEGHENY COUNTY MY COMMISSION EXPIRES JUNE 7,1983 Member, Pennsylvania Associaten of Nyarts 2246 153