ENS 57618
ENS Event | |
|---|---|
16:36 Mar 19, 2025 | |
| Title | Automatic Reactor Scram |
| Event Description | The following information was provided by the licensee via phone and email:
At approximately 1136 CDT on March 19, 2025, with Unit 1 in mode 1 at 97 percent power, a reactor water level transient occurred which resulted in an automatic reactor scram on low reactor pressure vessel water level. The scram was uncomplicated with all systems responding as expected. The cause of the event is under investigation. Containment isolation valves actuated and closed on a valid group 2 signal. Operations responded and stabilized the plant in mode 3. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. This event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B) due to the reactor protection system actuation while critical, and an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) for the Group 2 isolation signal. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The state of Minnesota as well as Wright and Sherburne counties will be notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: At the time of the event, condensate flushing evolutions were ongoing. It should be noted that prior to the reactor scram, a single feedwater pump tripped which would lower reactor water level. |
| Where | |
|---|---|
Monticello  Minnesota (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+-0.4 h-0.0167 days <br />-0.00238 weeks <br />-5.4792e-4 months <br />) | |
| Opened: | Tom Johnson 16:12 Mar 19, 2025 |
| NRC Officer: | Ernest West |
| Last Updated: | Mar 19, 2025 |
| 57618 - NRC Website
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