ENS 58036
ENS Event | |
|---|---|
17:50 Nov 12, 2025 | |
| Title | |
| Event Description | The following information was provided by the licensee via phone and email:
On November 12, 2025, at approximately 1250 EST, during surveillance testing of the high-pressure coolant injection (HPCI) system the HPCI minimum flow valve (E4150F012) would not open during stroke testing. HPCI had been removed from service for quarterly surveillance testing at 0957, November 12, 2025. The unplanned inoperability condition began at 1250 when a stroke time test was attempted, and the valve did not reposition. Since HPCI is a single-train safety system, this meets the criterion for event notification per 10CFR50.72(b)(3)(v)(D) as a condition that, at the time of discovery, could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident, based on loss of a single train safety system. Reactor core isolation cooling was and has remained operable. The Senior NRC Resident Inspector has been notified. The failure is currently under investigation. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Limiting conditions for operation 3.5.1 and 3.6.1.3 were entered to address HPCI inoperable. The site remains on normal offsite power, and all emergency diesel generators remain available.
The following information was provided by the licensee via phone and email: Following the initial [event notification] EN, further analysis of the condition identified that the HPCI system would have been able to perform its safety function with the minimum flow valve failed closed. Therefore, HPCI is considered operable. No other concerns were noted during the event. HPCI remained operable and there was no loss of safety function. The event did not involve a condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident under 10 CFR 50.72(b)(3)(v)(D). Therefore, the NRC non-emergency 10CFR50.72(b)(3)(v)(D) report was not required and the NRC report 58036 can be retracted and no Licensee Event Report under 10 CFR 50.73(a)(2)(v)(D) is required to be submitted. The NRC Resident Inspector was notified. Notified R3DO (Sanchez Santiago) |
| Where | |
|---|---|
Fermi  Michigan (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+1.4 h0.0583 days <br />0.00833 weeks <br />0.00192 months <br />) | |
| Opened: | Jeffrey Myers 19:14 Nov 12, 2025 |
| NRC Officer: | Ian Howard |
| Last Updated: | Dec 30, 2025 |
| 58036 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |