ML19317G997
| ML19317G997 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 12/15/1976 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| Shared Package | |
| ML19317G998 | List: |
| References | |
| NUDOCS 8004020656 | |
| Download: ML19317G997 (3) | |
Text
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Docket File December 15, 1976 NRC PDR L PDR ORB #4 Rdg Docket'No.: 50-312 VStello KRGoller TJCarter Attorney, OELD OI&E (K3)
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Sacramento Municipal Utility District RReid ATTH: Mr. J. J. Mattimoe VRooney (2)
Assistant General Manager RIngran.
and Chief Engineer DElliott 6201 S Street DEisenhut P. O. Box 15830 TBAbernathy Sacramento, California 95813 JRBuchanan ACRS (16)
Gentlemen:
Gray File During the course of our review of emergency core cooling system (ECCS) evaluation models, it has come to our attention that the iz Babcock and Wilcox (B&W) ECCS evaluation model, which was used
'T for your facility, uses a nucleate boiling heat transfer correlation during blowdown after critical heat flux (CHF) is first predicted.
This may not conform to the requirements of Appendix K to 10 CFR
- 50. The criteria for compliance with Appendix K have been established by the NRC staff and discussed with B&W representa-tives. Enclosed is a copy of our letter to B&W requesting that a corrected ECCS model be submitted for our evaluation as soon as possiLle.
This natter is similar to one identified with respect to another nuclear steam system supplier's evaluation model; and, based on our experience in connection with developing a correction for that model, we have concluded that there are acceptable correlations which can be used and which have a small effect on the calculated s
peak clad temperature.
It is expected that the effect on calculated peak clad temperature would be small enough so that modification of your Technical Specifications will not be required; however, j
o this must be verified for your facility by reevaluation of the ECCS cooling performance using a corrected model.
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==e Acc'ordingly, submit as soon as possible, a reevaluation of your m.su-ECCS cooling performance using an NRC staff approved model that se does not use a nucleate boiling heat transfer correlation during
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blowdown after CHF has been predicted by the approved CHF correlation.
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Sincerely,
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Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors cc: See next page as=
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Sacramento Municipal Utility District
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cc: Davia S. Kaplan, Secretary and General Counsel
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6201 S Street 1..
Post Office Box 15830
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Sacramento, California 95813
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Business and Municipal Department Sacramento City-County Library E
828 I Street Sacramento, California 95814 t
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