|Power Reactor||Event Number: 47523|
Region: 3 State: MI
Unit:  [ ] [ ]
RX Type:  CE
NRC Notified By: MIKE LEE
HQ OPS Officer: VINCE KLCO
|Notification Date: 12/14/2011
Notification Time: 16:40 [ET]
Event Date: 12/14/2011
Event Time: 15:10 [EST]
Last Update Date: 12/14/2011
|Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) – RPS ACTUATION – CRITICAL
50.72(b)(3)(iv)(A) – VALID SPECIF SYS ACTUATION
OTHER UNSPEC REQMNT
HIRONORI PETERSON (R3DO)
|Unit||SCRAM Code||RX CRIT||Initial PWR||Initial RX Mode||Current PWR||Current RX Mode|
|1||M/R||Y||100||Power Operation||0||Hot Standby|
|MANUAL REACTOR TRIP DUE TO LOSS OF BOTH MAIN FEEDPUMPS
“The reactor was manually tripped at 1510 EST on 12/14/11 due to loss of both main feedpumps. Both feedpumps tripped on low suction pressure due to an apparent unplanned opening of the ‘A’ main feedpump recirculation valve. The cause of the main feedpump recirculation valve opening has not been determined. All full length control rods fully inserted. Auxiliary feed pump P-8A automatically started at 1511 EST on steam generator level as designed (10CFR50.72(b)(3)(iv)(A)). The turbine bypass valve is in service maintaining reactor coolant system temperature [by directing steam flow to the main condenser]. The plant is stable in mode 3 [and the reactor trip was considered uncomplicated].
“The Van Buren County Sherriff was notified [per other plant requirements] concerning use of the atmospheric steam dump causing excessive noise in the vicinity of the plant [immediately following the plant trip].”
The plant electric power is in the normal shutdown configuration. There was no primary to secondary leakage.
A press release is planned for the local media.
The licensee notified the NRC Resident Inspector.
Source: NRC Event Notifications