ML20090K291

Informs That Final Repts Re BWR Owners Group Evaluation of MSIV Leakage & Preventive Maint Program Addressing SEP Topic XV-19 Re Consequences of Design Basis LOCAs Will Be Transmitted to NRC by End of 1984

ML20090K291
Person / Time
Site:	Oyster Creek
Issue date:	05/18/1984
From:	Fiedler P GENERAL PUBLIC UTILITIES CORP.
To:	Crutchfield D Office of Nuclear Reactor Regulation
References
TASK-15-19, TASK-RR NUDOCS 8405240132
Download: ML20090K291 (2)

Text

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g GPU Nuclear Corporation UCgME 100 lnterpace Parkway Parsippany. New Jersey 07054-1149 (201)263-6500 TELEX 136-482 Writer's Direct Dial Number:

May 18, 1984 Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch #5 U.S. Nuclear Regulatory Commission Washington, D. C.

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Subject:

Oyster Creek Nuclear Generating Station Docket No. 50-219 SEP Topic No. XV-19 LOCA Resulting From Spectrum of Postulated Piping Breaks Within the Reactor Coolant Pressure Boundary During the review of the subject SEP topic, the NRC staff performed an independent analysis on the radiological consequences of a design-basis loss-of-coolant accident. The analysis resulted in excessive thyroid doses for the 30 day low population zone boundary (341 rems).

In view of the small difference between the calculated offsite dose and the acceptance criteria (10CFR100.ll) and the conservatisms in the staff's calculational techniques, the NRC staff concluded that further analysis of this event is not warranted.

However, a significant contribution to the calculated offsite dose was from the main steam line isolation valve (MSIV) leakage. On the basis of previous experience of MSIV leakage at Oyster Creek Nuclear Generating Station, the NRC staff concluded that GPU Nuclear should develop and implement a preventive maintenance progrdm aimed at maintaining the MSIV leakage within the existing limit, or justify why the existing maintenance program is adequate.

In September, 1982 BWR Owners Group formed a subcommittee to address the MSIV-leakage issue with investigation in the following areas:

(1) Development of a technique for evaluation of BWR MSIV leakage contribution to radiological dose rate.

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j 1 1 (2) Collection of MSIV leakage data to establish clear cause for local leak rate test failure.

(3) Development of potential operator-action guidelines for preventing MSIV leakage or mitigating its effects.

GPU Nuclear has been an active participant in the Subcommittee. The investigation has recently been completed and the final reports addressing the areas of concern listed above have been issued to the member utilities of the Subcommittee. GPU Nuclear will shortly be evaluating the reports for plant specific applications. The results of this evaluation and identification of any related specific actions to be taken for Oyster Creek will be transmitted to you by the end of 1984.

Very truly yours, Ash

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edler Vice President and Director Oyster Creek 1r/0235e cc: Administrator RegionI U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pa.

19406 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, N.d.

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