Approximately five hours after Beaver Valley Power Station Unit No. 1 was shutdown at
0011 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> [EDT] to enter a scheduled refueling outage, an approximate 5 drops per minute leak was identified from a drain valve on the
Residual Heat Removal (
RHR) System inside containment. This leak is downstream of the two series
RHR isolation valves on a pipe which connects to both trains of
RHR. The actual location of the leak on the valve was not immediately evident. An evaluation was requested. At
1011 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.846855e-4 months <br />, the evaluation reported a 270 degree circumferential crack in the socket
weld on the
RHR side of the valve. Without reasonable assurance of
RHR System operability, both trains of
RHR were declared
inoperable. Both trains of the
RHR System are currently in service, along with three
steam generators/condenser remaining available for
decay heat removal. Actions to address this condition are being pursued.
This is being reported as a condition that at the time of discovery could have prevented the fulfillment of the safety function of systems needed to remove decay heat pursuant to 10 CFR 50.72(b)(3)(v)(B) since both trains of RHR were declared inoperable.
Beaver Valley Power Station Unit No. 2 is unaffected by this event and remains at 100 percent power.
The NRC Resident Inspector has been notified.
T.S. Action 3.4.7 requires that efforts be immediately initiated to restore
RHR as soon as possible.