19:28 Sep 12, 2017
Secondary Containment Pressure Momentarily Above Technical Specification Limit
On September 12, 2017, at 1228 PDT, Reactor Building (Secondary Containment) pressure momentarily rose above the Technical Specification (TS) limit. Secondary Containment was declared inoperable and TS Action Statement 220.127.116.11.A was entered. The pressure rise was due to unexpected isolation of the supply and exhaust valves in the Reactor Building ventilation system due to an electrical transient on the power panel feeding the valve operators' solenoid pilot valves during maintenance. The cause of the electrical transient is under investigation.
The Reactor Building differential pressure controller restored the building pressure to within limits. The Control Room operators reopened the Reactor Building ventilation supply and exhaust valves. Secondary Containment was declared operable at 1228 PDT and TS Action Statement 18.104.22.168.A was exited.
This condition is being reported under 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72(b)(3)(v)(D) for an event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material and accident mitigation.The licensee notified the NRC Resident Inspector.
|Columbia Generating Station |
Washington (NRC Region 4)
|10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material|
10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident
|Time - Person (Reporting Time:+-0.28 h-0.0117 days <br />-0.00167 weeks <br />-3.83544e-4 months <br />)|
19:11 Sep 12, 2017
|NRC Officer:||Mark Abramovitz|
|Last Updated:||Sep 12, 2017|
|52966 - NRC Website|