ENS 55963
ENS Event | |
|---|---|
01:12 Jun 25, 2022 | |
| Title | Automatic Reactor Trip Due to Main Steam Isolation Valve Closure |
| Event Description | The following information was provided by the licensee via email:
At 2012 CDT, Waterford 3 Steam Electric Station, Unit 3 was operating at 100 percent power when an automatic reactor trip occurred due to Main Steam Isolation Valve MS-124B going closed unexpectedly. Subsequently, both main feedwater isolation valves shut. Emergency Feedwater (EFW) was automatically actuated. Preliminary evaluation indicates that all plant systems functioned normally after the reactor trip. The unit is currently stable in Mode 3. All control rods fully inserted as expected and all other plant equipment functioned as expected. This was an uncomplicated scram. This event is being reported as a 4-hour non-emergency notification in accordance with 10 CFR 50.72(b)(2)(iv)(B) as an actuation of the reactor protection system (RPS) when the reactor is critical and as an 8-hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as valid actuation of the EFW system. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Waterford  Louisiana (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| LER: | 05000382/LER-2022-005 Engineered Safety Features Actuation System Relay Failure Results in Reactor Trip and Emergency Feedwater Actuation |
| Time - Person (Reporting Time:+-0.47 h-0.0196 days <br />-0.0028 weeks <br />-6.43806e-4 months <br />) | |
| Opened: | William Crowley 00:44 Jun 25, 2022 |
| NRC Officer: | Michael Bloodgood |
| Last Updated: | Jun 25, 2022 |
| 55963 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | A/R |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |