On July 5, 2011, a licensee-identified violation of Unit 2
TS 3.4.3 was discovered.
TS section 3.4.3 requires 10 of 11
safety relief valves (
SRVs) to be
operable during Mode 1, 2, and 3. Contrary to this requirement it was identified during
bench testing that eight
safety relief valves failed to lift at the required technical specification setpoint, and therefore where
inoperable when Unit 2 was in Mode 1, 2, and 3. The cause for the
SRVs failing to lift within the required setpoint was due to corrosion induced bonding between the pilot disc and seating surface. This condition was documented in CR 334250. Analysis showed that with the
SRVs lifting at the as-found
bench test setpoints the
SRVs still would have maintained
reactor coolant system pressure below the TS safety limit requirements. Therefore, this finding was determined to be of very low safety significance
