UNUSUAL EVENT DUE TO LOSS OF OFFSITE POWER
At 0329 EDT, Oyster Creek experienced a loss of offsite power. As a result of the loss of offsite power, the unit automatically scrammed from 100% with all control rods fully inserting and all safety systems functioning as required. Both Emergency Diesel Generators automatically started and are carrying loads on the safety buses.
At 0341 EDT, Oyster Creek declared an Unusual Event based on a loss of offsite power for greater than 15 minutes. The unit is stable in Hot Shutdown with decay heat removal via the Isolation Condenser. The cause of the loss of offsite power is currently under investigation by JCP&L.
The licensee notified the State and local agencies, as well as the NRC Resident Inspector. The licensee will be making a press release.
* * * UPDATE ON 7/23/12 AT 0625 EDT FROM ROBERT SALES TO DONG PARK * * *
"Oyster Creek has terminated from the loss of offsite power Unusual Event [at 0538 EDT]. All safety systems functioned as expected for this event."
The licensee has notified the NRC Resident Inspector.
Notified R1DO (Dimitriadis), NRR EO (Nieh), IRD (Gott), DHS SWO, FEMA, and DHS NICC.
* * * UPDATE ON 7/23/12 AT 1205 EDT FROM ANDREW ZUCHOWSKI TO VINCE KLCO * * *
"As a result of the loss of offsite power, both Emergency Diesel Generators automatically started and carried loads on the safety buses, as required. Offsite power was returned to service at 0457 EDT and both Emergency Diesel Generators were secured at 0520 EDT.
"Per 50.72(b)(3)(iv)(A), Oyster Creek is reporting any event or condition that results in valid actuation of an Emergency AC electrical power system.
"Additionally, the Reactor Building (Secondary Containment) differential pressure indicated positive 0.25 inches W.G. at approximately 0357 EDT. Reactor Building differential pressure indication returned to normal at 0434 EDT. Oyster Creek is currently investigating the cause of the positive Reactor Building pressure indication.
"Per 50.72(b)(3)(v)(C), Oyster Creek is reporting an event that could have prevented the fulfillment of the safety function of a system needed to control the release of radioactive material."
The licensee notified the NRC Resident Inspector.
Notified R1DO (Gray). |