ENS Event | |
|---|---|
15:13 Oct 6, 2025 | |
| Title | 60-DAY Optional Telephonic Notification of Invalid Specified System Actuation |
| Event Description | The following information was provided by the licensee via phone and email:
At 0913 CDT, on October 6, 2025, a partial actuation of the division 1 emergency diesel generator (DG1) occurred during the performance of the 4160-volt bus 1F undervoltage relay channel functional test. The DG1 automatic start in the emergency mode was the result of the inadvertent contact between a jumper and another component. However, due to the test configuration, the output breaker for DG 1 did not close and pick up the load of the 4160-volt bus 1F since no actual undervoltage condition was present. DG1 components functioned as expected in response. Following the actuation, DG1 was restored to a standby lineup in accordance with plant procedures. This event is considered an invalid system actuation reportable under 10 CFR 50.73(a)(2)(iv)(A). The actuation was not initiated in response to actual plant conditions or parameters and was not a manual initiation. Therefore, in accordance with 10 CFR 50.73(a)(1), this telephone notification is provided within 60 days after discovery of the event instead of submitting a written licensee event report. The NRC Resident lnspector has been notified. |
| Where | |
|---|---|
Cooper  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1368.7 h57.029 days <br />8.147 weeks <br />1.875 months <br />) | |
| Opened: | Brian Stander 16:55 Dec 2, 2025 |
| NRC Officer: | Kerby Scales |
| Last Updated: | Dec 2, 2025 |
| 58068 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 580682025-10-06T15:13:0006 October 2025 15:13:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification of Invalid Specified System Actuation ENS 537762018-10-13T05:00:00013 October 2018 05:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Specified System Actuation ENS 524362016-10-28T07:39:00028 October 2016 07:39:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 463672010-08-31T22:37:00031 August 2010 22:37:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation Due to a Voltage Transient ENS 430972006-11-20T02:28:00020 November 2006 02:28:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Primary Containment Isolation System ENS 406972004-03-09T18:42:0009 March 2004 18:42:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation Due to Momentary Power Interruption 2025-10-06T15:13:00 | |