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Event Notification Report for November 30, 2019

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
11/29/2019 - 11/30/2019

EVENT NUMBERS
54417

Power Reactor
Event Number: 54417
Facility: DIABLO CANYON
Region: 4     State: CA
Unit: [] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ERIC THOMAS
HQ OPS Officer: ANDREW WAUGH
Notification Date: 11/30/2019
Notification Time: 19:48 [ET]
Event Date: 11/30/2019
Event Time: 11:00 [PST]
Last Update Date: 11/30/2019
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
Person (Organization):
GREG PICK (R4DO)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N N 0 Hot Shutdown 0 Hot Shutdown
Event Text
BOTH TRAINS OF CONTAINMENT SPRAY REMOVED FROM SERVICE

"On November 30, 2019, at 1100 PST, with Unit 2 in Mode 4, Operations identified that both trains of containment spray had been removed from service earlier at approximately 0217 hours as part of preparations for a planned Mode 5 entry. The containment spray pumps are required to be operable (along with the containment fan cooler units) in Modes 1 through 4 in accordance with Technical Specification 3.6.6. With both containment spray pumps inoperable, TS 3.6.6 Action F requires the Unit to be shut down in accordance with TS 3.0.3. At 1125 hours, both trains of containment spray were returned to operable and the required actions of TS 3.6.6 and TS 3.0.3 were exited.

"The five containment fan cooler units remained operable for the duration of the occurrence.

"This notification is being made in accordance with the requirement of 10 CFR 50.72(b)(3)(v) as an event or condition that could have prevented fulfillment of a safety function, and 10 CFR 50.72(b)(3)(ii) as an event or condition that may have resulted in the plant being in an unanalyzed condition.

"The NRC Senior Resident Inspector has been notified."