09:29 Aug 22, 2021
HPCI Declared Inoperable
At 0529 EDT on August 22, 2021, HPCI [(High Pressure Coolant Injection System)] was declared inoperable due to receiving the HPCI Inverter Circuit Failure annunciator. The cause of the annunciator was a fuse failure. The cause of the fuse failure is unknown at this time and is under investigation. Concurrent with the HPCI fuse failure was a similar fuse failure within the Division 2 EDG [(emergency diesel generators)] Load Sequencer which renders the Division 2 EDGs inoperable. Relation to the HPCI issue is unknown and is part of the investigation.
The RCIC [(Reactor Core Isolation Cooling System)] was verified operable per Tech Spec 3.5.1 E.1. In addition, offsite circuits were verified operable per Tech Spec 3.8.1.B. Division 1 EDGs remain operable.
There was no impact on the health and safety of the public or plant personnel.The Senior NRC Resident Inspector has been notified.
Michigan (NRC Region 3)
|10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident|
|Time - Person (Reporting Time:+2.68 h0.112 days <br />0.016 weeks <br />0.00367 months <br />)|
12:10 Aug 22, 2021
|NRC Officer:||Thomas Kendzia|
|Last Updated:||Aug 22, 2021|
|55423 - NRC Website|