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Event Notification Report for February 22, 2001

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
02/21/2001 - 02/22/2001

EVENT NUMBERS
37772

Power Reactor
Event Number: 37772
Facility: MONTICELLO
Region: 3     State: MN
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: B. WELLER
HQ OPS Officer: JOHN MacKINNON
Notification Date: 02/22/2001
Notification Time: 21:34 [ET]
Event Date: 02/22/2001
Event Time: 18:30 [CST]
Last Update Date: 02/22/2001
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(B) - POT RHR INOP
Person (Organization):
MARK RING (R3)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 100 Power Operation
Event Text
"EVEN" TRAIN CORE SPRAY, RHR OR RHRSW PUMPS OPERATION FROM THE ALTERNATE SHUTDOWN SYSTEM COULD BE LOST DUE TO A POSTULATED HOT SHORT.

An Alternate Shutdown System design deficiency resulting in a vulnerability to a single hot short during a Control Room Cable Spreading Room fire has been identified. The effect of the postulated hot short would be to actuate the Bus 16 load shed logic while the bus is powered from the emergency diesel generator. This could result in the inability to operate the even train Core Spray, Residual Heat Removal (RHR) or RHR Service Water pumps. No means are in place to circumvent the postulated hot short. A one hour fire watch patrol in the cable spreading room and control room has been established with Alternate Shutdown System inoperable. All other Emergency Core Cooling Systems are fully operable.

The NRC Resident Inspector will be notified of this event by the licensee.