ML20161A161

Final ASP Analysis - Turkey Point 3 (LER 250-82-008)

ML20161A161
Person / Time
Site:	Turkey Point
Issue date:	06/09/2020
From:	Christopher Hunter NRC/RES/DRA/PRB
To:
Littlejohn J (301) 415-0428
References
LER 1982-008-00
Download: ML20161A161 (1)

Text

LER 250/82-008 Event

Description:

Failure of High-Head Safety Injection Pump Date of Event: June 9, 1982 Plant: Turkey Point 3 Summary On June 9, 1982 during power operation, the 3A high-head safety injection (HHSI) pump failed to start when the normal Unit 3 control switch was manually operated. The three remaining HHSI pumps were available. The breaker control panel fuses were replaced and the breaker was racked out and then back in. The 3A pump was then successfully started. No cause for the failure could be determined. The event was analyzed as a HHSI pump failure with a loss of feedwater (LOFW) transient.

A trip and apparent LOFW occurred on June 1, 1982. If a test interval of one month is assumed for the HHSI pumps and if HHSI pump 3A is assumed to have been unavailable for half of an interval, this event can be modeled as an HHSI pump failure in conjunction with an LOFW transient. One HHSI pump was assumed to be failed for both high-pressure injection (HPI) and feed-and-bleed functions. Since the cause of the failure was not identified, it was assumed that the remaining HHSI pumps were vulnerable to a similar failure. The conditional core damage probability estimated for this event is 3.3x10-6. The dominant core damage sequence involves the observed transient, successful reactor trip, loss of auxiliary and main feedwater, and failure of feed and bleed.