15:35 Oct 24, 2019
Automatic Depressurization System Inoperable
At 1035 CDT the Automatic Depressurization System (ADS) was rendered inoperable due to the failure of the 'A' Safety Vent Valve (SVV) Compressor (SVV-C4A) to manually start with SVV-C4B tagged out. System pressure slowly dropped below 131 psig (normal pressure is 165 psig). This caused the ADS safety relief valves to be declared inoperable. The station entered Technical Specification 3.5.1 Condition G. The Required Action was to be in Mode 3 in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. As a result, the station was in a condition that could have prevented the fulfillment of a safety function.
The breaker for SVV-C4B was reset and the clearance for SVV-V4B was released. System pressure was restored to greater than 131 psig at 1116 CDT which allowed exit of the action statement to be in Mode 3 in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. System parameters are currently stable in the normal pressure range. Investigation for the cause of the system failure is ongoing.
No radiological releases have occurred due to this event from the unit.The licensee notified the NRC Resident Inspector.
|River Bend |
Louisiana (NRC Region 4)
|10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor|
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
|LER:||look for an ler...|
|Time - Person (Reporting Time:+0.83 h0.0346 days <br />0.00494 weeks <br />0.00114 months <br />)|
16:25 Oct 24, 2019
|NRC Officer:||Donald Norwood|
|Last Updated:||Oct 24, 2019|
|54348 - NRC Website|