ML20128D941

Informs That Preliminary Review of Engineering Drawings for Proposed Design & Installation of Prompt Relief Trip Sys in Plant Revealed That Design Criterion,Re No More than One safety-relief Valve Will Be Inadvertently Actuated,Not Met

ML20128D941
Person / Time
Site:	Monticello
Issue date:	04/01/1974
From:	Stello V US ATOMIC ENERGY COMMISSION (AEC)
To:	Skovholt D US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9212070428
Download: ML20128D941 (2)

Text

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4 APR 1 1974 Docket No. 50-263 _

Donald .). Skovholt. Assistant Director for Operating Reactors. L NORTHER'1 STATES POWER COMPANY, MONTICELLO NUCLEAR GENERATING STATION, PROMPTRELIEFTRIPSYSTEM(PRT)

Our preliminary revicu of the engineering drawings for the proposed desion and installation of the FRT systen in the Monticello plant has revealed tnat the design critorion that no more than one safety-

' relief valve will be inadvertently actuated is not met. A single event in the PRT cabinet can inadvertently actuate nore than one safety-relief valve.

Unless this concern is satisfactorily resolved, installation of the PRT is not rectrriended, even though we can concluded that mere installation, but not actuation, of the PRT system can be made not to degrade e;isting safety systent considerably below their present design implenentation.

In addition, the following points reauire careful consideration in detemining but certainlyacceptability before actuation. of the PRT preferably before installation,

1. Inadvertent PRT actuation during a DBA. With this possibility in rind, it rey be necessary to incorporate pemissives similar to those of ADS.

2.

Unnecessary PRT actuation on lossoof RPS scram voltage.

3. Single Failure Criterion.

4. Environnental and seisnic qualification of components.

5.

The on-line testability provisions proposed by G.E. represent nerely a continuity test and are not acceptable. Since PRT is a new system and, as such, it will be incorporated in all BWRs. the Regulatory Guide 1.22 recommendations should be incorporated in its design.

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bPE I 1974 Donald J. Skovholt Our review for final acceptance of PRT is not complete, it will address the above concerns and will be performed within the schedule established for TAR-863.

Orictnnl s!Rnni by Yletor htcIlo Victor Stc110, Jr., Assistant Director for Reactor Safety Directorate of Licensinq cc: S. llanauer, DRTA A. Giambusso. L:RP J. llendrie L:TR V. Ste11n, L:RS W. Mcdonald, L:0PS D. 71cnann, L:0RP-2 J. Shea, L:0RD-2 T. Ippolito, L:EICS D. Tondi, L:EICS D. Basdekas, L:EICS DISTRIBUTION:

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