ENS 58109
ENS Event | |
|---|---|
13:48 Nov 12, 2025 | |
| Title | Invalid Specified System Actuation |
| Event Description | The following information was provided by the licensee via phone and email:
This report is being made in accordance with 10 CFR 50.73(a)(2)(iv)(A), using the telephone option in 10 CFR 50.73(a)(1) in lieu of a written licensee event report, concerning an event in which Callaway experienced an automatic actuation of the auxiliary feedwater (AFW) system in response to invalid AFW actuation signals. The reactor protection system was not involved. A low suction pressure signal was also received which aligned the AFW pumps to essential service water. An unknown amount of water from the ultimate heat sink entered the steam generators, necessitating a plant shutdown after secondary water chemistry program action levels were exceeded. This AFW actuation was complete and the AFW system started and functioned successfully in accordance with the initiating actuation signals. This actuation occurred at 0748 CST on November 12, 2025, and was reported (and later retracted) as event notification 58035. The most probable cause of the actuations was the intermittent failure of a 15V DC logic power supply within engineered safety features actuation system logic cabinet SA036D. The power supply was replaced. |
| Where | |
|---|---|
| Callaway Missouri (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1323.4 h55.142 days <br />7.877 weeks <br />1.813 months <br />) | |
| Opened: | Trevor Gladback 17:12 Jan 6, 2026 |
| NRC Officer: | Ernest West |
| Last Updated: | Jan 6, 2026 |
| 58109 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 581092025-11-12T13:48:00012 November 2025 13:48:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 570912024-03-25T01:56:00025 March 2024 01:56:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Automatic Turbine Driven Auxiliary Feedwater Pump ENS 559722022-05-02T04:05:0002 May 2022 04:05:00 Other Unspec Reqmnt, 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 491412013-04-24T09:04:00024 April 2013 09:04:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephone Notification for an Invalid Specified System Actuation ENS 491032013-04-11T06:28:00011 April 2013 06:28:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephone Notification for an Invalid Specified System Actuation 2025-11-12T13:48:00 | |