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Event Notification Report for October 18, 2020

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
10/17/2020 - 10/18/2020

EVENT NUMBERS
54954

!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 54954
Facility: Arkansas Nuclear
Region: 4     State: AR
Unit: [1] [2] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: Shane Hendrix
HQ OPS Officer: Andrew Waugh
Notification Date: 10/19/2020
Notification Time: 07:20 [ET]
Event Date: 10/18/2020
Event Time: 23:13 [CDT]
Last Update Date: 10/24/2020
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(D) - Accident Mitigation
Person (Organization):
RYAN ALEXANDER (R4DO)
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
2 N Y 100 Power Operation 100 Power Operation
Event Text
EN Revision Imported Date: 10/26/2020

EN Revision Text: CONTROL ROOM ENVELOPE INOPERABLE

"On October 18, 2020 at 2313 CDT, Arkansas Nuclear One (ANO) discovered that 2VRA-1B (2VSF-9 outside air damper reserve bottle) was below 600 psig. This condition caused the control room envelope to be inoperable in accordance with OP-2104.007 Attachment L. ANO Unit 1 entered TS 3.7.9 Condition B for inoperable control room boundary. ANO Unit 2 entered TS 3.7.6.1 Action D for inoperable control room boundary. A procedurally controlled temporary modification was implemented to install a blank flange on the 2VSF-9 outside air damper. Both Units declared the control room boundary operable at 2358 CDT. The associated control room emergency recirculation fan remains inoperable with the blank flange installed. This is a 7-day shutdown-LCO for both units.

"The licensee informed the NRC Resident Inspector."

* * * RETRACTION FROM AARON TOSCH TO HOWIE CROUCH ON 10/24/2020 AT 1657 EDT * * *..

"Previously, Entergy notified the NRC that ANO control room envelope was inoperable due to 2VRA-1B (2VSF-9 outside air damper reserve bottle) was below required pressure of 600 psig. After additional engineering evaluation, it was determined the control room boundary remained intact for this condition.

"As documented in version 2 operability determination for condition report ANO-C-2020-2818, the control room ventilation boundary remained intact for the condition identified and was able to fulfill its function for the required 30-day mission time.

"In accordance with NUREG-1022, 'Event Report Guidelines 10 CFR 50.72 and 50.73,' a report may be retracted based on a revised operability determination. The CRE remained operable; therefore, this report may be retracted.

"The NRC Resident Inspector has been informed."

Notified R4DO (Pick).