On November 14, 2013, both the 2-220-58B Feed Water Inboard
Check Valve and the 2-220-62B Feed Water Outboard
Check Valve failed
Local Leak Rate Testing (
LLRT) acceptance criteria. These valves are considered
primary containment isolation valves and, as such, are required to ensure that an adequate
primary containment boundary is maintained.
Technical Specification (TS) 5.5.12, 'Primary Containment Leakage Rate Testing Program,' establishes limits for Primary Containment leakage. Based upon the results of the LLRT, Dresden, Unit 2, may not have met the limits for primary containment leakage during the last operating cycle as specified in TS 5.5.12.c.
Dresden Unit 2 is currently in Mode 5 for a refueling outage and per Dresden TS 3.6.1.1, 'Primary Containment,' Primary Containment is not required in the current mode of operation (i.e., Mode 5). However, in accordance with 10 CFR 50.72(b)(3)(ii)(A), this event is reportable as a condition that resulted in a principal safety barrier being seriously degraded.
The NRC Resident Inspector has been notified [by the licensee].
