ML20063N595

Forwards Questions for Applicant Re Frequency of Simultaneous Loss of Three Main Cooling Loops,Discussed During 820715 Meeting

ML20063N595
Person / Time
Site:	Clinch River
Issue date:	07/16/1982
From:	Atefi B, Liner R SCIENCE APPLICATIONS INTERNATIONAL CORP. (FORMERLY
To:	Swift J NRC
Shared Package
ML20063N588	List: ML20063N590 ML20063N592 ML20063N593 ML20063N594 ML20063N595
References
CON-NRC-03-82-096, CON-NRC-3-82-96, FOIA-82-342 NUDOCS 8210040355
Download: ML20063N595 (2)

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United States Nuclear Regulatory Commission 1710 Goodridge Drive ,

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SAI Project 1-186-03-020-XX NRC Contract NRC-03-82-096 SAI Task Ed'd -d ,' /-/f 6 0 3 -T '/ 2.,c; t_

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i Question for the CRBR applicant regarding frequency of simultaneous loss of three main cooling loops.

Please provide your estimate of the total frequency (events per year) of all three main heat transport loops being disabled at the same ,

, time. The interest here is on cases where no heat can be removed by the three main heat transport loops and the only means of heat removal is the Direct Heat Removal Service (DHRS), Please indicate the contri-butions of various initiators, such as common-cause failure of the rupture disks at the sodium inlet of the superheater, or sodium o'utlet of the evaporators in all three loops, to the above frequency. In addition, please indicate the uncertainties in your estimates. Pl ease identify your soure.es of information and data and describe the rationale for your estimation process. ,

What fraction of operating time would you expect the plant to operate.(at a substantial power level) with one of the main heat trans-port loops out of service? Under such circumstances, what would be the probability or frequency of losing the remaining two loops simul-taneously such that DHRS would be needed?

Can the plant operate with only one main cooling loop in service?

If so, what fraction of time would you expect it to do so?

Atefi/ Liner July 16, 1982 l

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