ML20245B596

Forwards Inadequate NPSH in HPSI Sys in Pwrs, Engineering Evaluation Rept.Issue Similar to AEOD Rept on NPSH Problems in Low Head Safety Sys

ML20245B596
Person / Time
Site:	Oconee, Turkey Point, 05000000
Issue date:	08/09/1988
From:	Novak T NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
To:	Rossi C Office of Nuclear Reactor Regulation
Shared Package
ML20245B599	List: ML20245B596 ML20245B606
References
AEOD-E803, NUDOCS 8904260169
Download: ML20245B596 (1)

Text

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AUG 0 91988

... c.

MEMORANDUM FOR: Charles E. Rossi, Director Division of Operational Events Assessment Office of Nuclear Reactor Regulation FROM: Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation of Operational Data

SUBJECT:

INADEQUATE NPSH FOR HIGH PRESSURE SAFETY INJECTION SYSTEMS IN PWRs Enclosed is an Engineering Evaluation report on inadequate NPSH for high pressure safety injection systems in PWRs. This issue is similar to an earlier AE0D report on NPSH problems in low head safety systems. In this case, it appears that the problem is limited to those PWRs that " piggyback" the HPSI pumps off the low head pumps in the recirculation phase following a LOCA. This issue is important because the HPSI is needed to mitigate small LOCAs and in some plants it is used for hot leg recirculation even for large LOCAs.

We have also enclosed a draft supplement to the information notice (87-63) on the low pressure safety system NPSH problem. We recommend that this supplement be sent to all PWR licensees and construction permittees to alert them to this potential problem. Preoperational and postoperational testing are not likely to detect this problem. For further information regarding this study, please contact S. Israel (X24437) of my staff. We shall be pleased to meet with you or your staff to discuss this report.

Ortenut stus By Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation of Operational Data

Enclosure:

As stated Distribution:

PDR WLanning EJordan JPartlow JHeltemes MTaylor r ya JRosenthal l Plam l

SIsrael KBlack MWilliams

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