Part 21 Report - 1995-027
PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION I JANUARY 25,
1995
Licensee/Facility: Notification:
Public Service Electric & Gas Co. MR Number: 1-95-0009
Hope Creek 1 Date: 01/25/95
Hancocks Bridge,New Jersey SRI PC
Dockets: 50-354
BWR/GE-4
Subject: ANCHOR-DARLING SWING CHECK VALVES
Reportable Event Number: N/A
Discussion:
On November 16, 1994, during a core spray system inservice test, a pump
discharge check valve stuck open allowing reverse flow through the
associated pump and causing it to spin in reverse at approximately 1500
rpm before the flow was stopped. An internal inspection of the valve
following the event identified deformation in the valve body casting
caused by contact with the disk hinge arm. The licensee surmised that
this was an indication of excessive disk travel that was allowing the
valve to "stick open."
On January 19, 1995, during an internal valve inspection resulting from a
generic review following the November 16 event, PSE&G technicians noted
deformation in the body of a safety auxiliaries cooling system (SACS)
pump discharge check valve. Previously this system had experienced
pressure/flow oscillations which may be attributed to check valve
anomalies.
The valves in question are Anchor-Darling swing check valves. The
licensee has identified a population of 32 of these valves (of various
dimensions - 12", 16", 20") in safety related plant systems. The licensee
intends to continue to open and inspect the remainder of these valves
during upcoming scheduled system outages. The root cause of the failure
mechanism has not been established, in part because the internals are
suspended from the cover which must be removed in order to conduct the
inspection. Consequently, the actual "as found" condition is difficult to
observe and assess. The licensee is considering notification in
accordance with 10 CFR 21.
Regional Action:
Resident inspectors will continue to monitor the licensee's review of
this issue and will report any further indications of its generic nature
and/or significance as it pertains to the operability of safety-related
systems.
Contact: John White (610)337-5114
Robert Summers (610)337-5189
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