Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 85 Power Operation 85 Power Operation
UNUSUAL EVENT AND PLANT SHUTDOWN DUE TO DRYWELL UNIDENTIFIED LEAKAGE GREATER THAN 10 GPM
“At 0152 [EDT], Nine Mile Point Unit 2 received red alarms for containment monitoring cabinets 10A and 10B along with a rise in drywell floor drain leakage and drywell pressure.
“At 0205 [EDT], Nine Mile Point Unit 2 entered technical specification action statement (TS 3.4.5 B) due to unidentified leakage rise of greater than 2 gpm within 24 hours.
“At 0217 EDT, the control room commenced power reduction to mitigate the rise in drywell leakage and drywell pressure.
“At 0322 EDT, Nine Mile Point Unit 2 declared an Unusual Event (EAL 2.1.1) due to unidentified drywell leakage greater than 10 gpm. Actual drywell floor drain leakage reached 11.3 gpm.
“The cause of the rise in unidentified leakage is unknown at this time.
“At 0345 EDT, Nine Mile Point Unit 2 has commenced a plant shutdown.”
The licensee has notified State and local authorities. The NRC Resident Inspector has been notified.
* * * UPDATE ON 08/06/2011 AT 1140 EDT FROM JULIAN THOMPSON TO DAN LIVERMORE * * *
The licensee terminated Notice of Unusual Event at 1127 EDT because leakage rates, drywell level, drywell pressure, rad levels, and all other parameters on the licensee checklist were normal and stable.
The licensee is continuing to power down in order to perform inspections in the drywell area.
The licensee notified State and local authorities and the NRC Resident Inspector.
Notified: IRD MOC (Gott), R1RA (Dean), R1DO (Bellamy), NRR (Leeds), NRR EO (Cheok), DHS (Inzer) and FEMA (O’Connel) .