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Home NRC Library Document Collections Events, Reports Associated with Event Notification Reports 2021

Event Notification Report for November 16, 2021

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
11/15/2021 - 11/16/2021

EVENT NUMBERS
55575 55576 55580
Power Reactor
Event Number: 55575
Facility: Peach Bottom
Region: 1     State: PA
Unit: [2] [] []
RX Type: [2] GE-4,[3] GE-4
NRC Notified By: Chris Wainaina
HQ OPS Officer: Karen Cotton
Notification Date: 11/14/2021
Notification Time: 08:50 [ET]
Event Date: 11/14/2021
Event Time: 05:25 [EST]
Last Update Date: 11/14/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical
Person (Organization):
Henrion, Mark (R1)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 M/R Y 100 Power Operation 0 Hot Standby
Event Text
EN Revision Imported Date: 11/16/2021

EN Revision Text: MANUAL TRIP DUE TO LOWERING MAIN CONDENSER VACUUM
At 0525 EST, November 14, 2021, "Unit 2 was manually scammed by operations due to lowering main condenser vacuum. This resulted in PCIS (process control and instrumentation system) Group II/III isolation signals. All control rods inserted, and all systems operated as designed."

Unit 3 is unaffected and remains at 100 percent power in Mode 1.

The Resident Inspector was notified.


Power Reactor
Event Number: 55576
Facility: Millstone
Region: 1     State: CT
Unit: [2] [] []
RX Type: [1] GE-3,[2] CE,[3] W-4-LP
NRC Notified By: Sunyoung Kwon
HQ OPS Officer: Donald Norwood
Notification Date: 11/14/2021
Notification Time: 17:06 [ET]
Event Date: 11/14/2021
Event Time: 11:50 [EST]
Last Update Date: 11/14/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(ii)(B) - Unanalyzed Condition
Person (Organization):
Henrion, Mark (R1)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 100 Power Operation 100 Power Operation
Event Text
EN Revision Imported Date: 11/16/2021

EN Revision Text: NON-FUNCTIONAL STEAM SUPPLY CHECK VALVE TO TURBINE DRIVEN AUXILIARY FEEDWATER PUMP

"On November 14, 2021, at 1150 EST, while operating in Mode 1 at 100 percent power, the supply check valve from the Number 2 steam generator to the turbine driven auxiliary feedwater pump was determined during troubleshooting that it is not able to perform its isolation function. This failure would have resulted in the blowdown of both steam generators during a main steam line break in the Number 2 steam generator main steam line upstream of the main steam isolation valves until the operators could isolate the faulted steam generator. Previous evaluation has determined that this condition constituted an unanalyzed condition that could impact containment pressure.

"There has been no radioactive release to the environment. The steam lines from the steam generators to the turbine driven auxiliary feedwater pump have been isolated by use of a motor operated valve in the discharge line of the Number 2 steam generator. There has been no impact to Unit 3 which remains at 100 percent power.

"The NRC Senior Resident has been notified.

"This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety."


Power Reactor
Event Number: 55580
Facility: Summer
Region: 2     State: SC
Unit: [1] [] []
RX Type: [1] W-3-LP,[2] W-AP1000,[3] W-AP1000
NRC Notified By: Leon Smith
HQ OPS Officer: Donald Norwood
Notification Date: 11/15/2021
Notification Time: 21:00 [ET]
Event Date: 11/15/2021
Event Time: 17:28 [EST]
Last Update Date: 11/15/2021
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
Person (Organization):
Miller, Mark (R2)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
1 M/R Y 47 Power Operation 0 Hot Standby
Event Text
MANUAL REACTOR TRIP DUE TO MAIN TRANSFORMER FAULT

"At 1728 EST on 11/15/2021, with Unit 1 in Mode 1 at 47 percent power, the reactor was manually tripped due to a main transformer fault. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being removed by the emergency feedwater system through the main condenser.

"Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B).

"Additionally, due to the valid actuation of the emergency feedwater system, this event is being reported as a non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A).

"There was no impact on the health and safety of the public or plant personnel. The NRC Senior Resident Inspector has been notified."