05000458/LER-2021-001, Manual Reactor Scram Due to Loss of Main Condenser Vacuum
| ML21141A193 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 05/20/2021 |
| From: | Vercelli S Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RBG-48094 LER 2021-01-00 | |
| Download: ML21141A193 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| 4582021001R00 - NRC Website | |
text
Abstract
On March 25, 2021 at 09:01 CDT, River Bend Station was operating at 93% reactor power when Main Condenser vacuum began to lower. Reactor power was lowered in an attempt to maintain Main Condenser vacuum. At 09:18 a manual reactor scram was initiated from approximately 80% reactor power due to Main Condenser vacuum continuing to lower. All control rods fully inserted and there were no complications. All systems responded as designed.
The loss of vacuum was caused by the in-service Steam Air Ejector Suction Valve closing due to faults within the valves control components. The Steam Air Ejector Suction Valve function was restored by replacing the faulted components.
River Bend Station will establish a program to test the fail-as-is function of the Steam Air Ejector Suction Valves every outage.