Event Notification Report for July 25, 2021
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
07/24/2021 - 07/25/2021
EVENT NUMBERS
55379
55379
Power Reactor
Event Number: 55379
Facility: Sequoyah
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Ben Hammargren
HQ OPS Officer: Brian P. Smith
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Ben Hammargren
HQ OPS Officer: Brian P. Smith
Notification Date: 07/25/2021
Notification Time: 16:00 [ET]
Event Date: 07/25/2021
Event Time: 12:38 [EDT]
Last Update Date: 07/25/2021
Notification Time: 16:00 [ET]
Event Date: 07/25/2021
Event Time: 12:38 [EDT]
Last Update Date: 07/25/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(C) - Pot Uncntrl Rad Rel 50.72(b)(3)(v)(D) - Accident Mitigation
10 CFR Section:
50.72(b)(3)(v)(C) - Pot Uncntrl Rad Rel 50.72(b)(3)(v)(D) - Accident Mitigation
Person (Organization):
MILLER, MARK (R2)
MILLER, MARK (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
EN Revision Imported Date: 8/25/2021
EN Revision Text: SURVEILLENCE FREQUENCY EXCEEDED FOR ICE CONDENSER TEMPERATURE
"At 1238 EDT on July 25, 2021, the Unit 2 Ice Bed became INOPERABLE due to SR [Surveillance Requirement] 3.6.12.1 exceeding its surveillance interval. LCO [Limiting Condition for Operation] 3.6.12 was declared not met as required by SR 3.0.1.
"SR 3.6.12.1 to verify maximum ice bed temperature is less than or equal to 27 degrees F could not be completed due to a failed temperature recorder. The results of the backup method of temperature verification were verified satisfactory at 1258 EDT and the LCO condition was then exited.
"The ice bed is a single train system which functions to control radiation release and mitigate the consequences of an accident by scrubbing radioactive iodine and providing a heat sink to limit containment pressure within design limits, therefore the requirements of 10 CFR 50.72 (b) (3) (v) (C) and (D) were met.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
EN Revision Text: SURVEILLENCE FREQUENCY EXCEEDED FOR ICE CONDENSER TEMPERATURE
"At 1238 EDT on July 25, 2021, the Unit 2 Ice Bed became INOPERABLE due to SR [Surveillance Requirement] 3.6.12.1 exceeding its surveillance interval. LCO [Limiting Condition for Operation] 3.6.12 was declared not met as required by SR 3.0.1.
"SR 3.6.12.1 to verify maximum ice bed temperature is less than or equal to 27 degrees F could not be completed due to a failed temperature recorder. The results of the backup method of temperature verification were verified satisfactory at 1258 EDT and the LCO condition was then exited.
"The ice bed is a single train system which functions to control radiation release and mitigate the consequences of an accident by scrubbing radioactive iodine and providing a heat sink to limit containment pressure within design limits, therefore the requirements of 10 CFR 50.72 (b) (3) (v) (C) and (D) were met.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."