Semantic search
| Entered date | Event description | |
|---|---|---|
| ENS 53068 | 13 November 2017 17:26:00 | A licensed supervisor had a confirmed positive test for alcohol. The employee was escorted offsite and their plant access has been terminated and a five year denial placed in Personnel Access Data System (PADS). This is being reported per 10 CFR 26.719(b)(2)(ii). The NRC Resident Inspector has been notified. |
| ENS 52999 | 3 October 2017 16:58:00 | On October 3, 2017, at 0800 PDT, Reactor Building (Secondary Containment) pressure momentarily rose above the Technical Specification (TS) limit. Secondary Containment was declared inoperable and TS Action Statement 3.6.4.1.A was entered. The pressure rise was due to unexpected isolation of an exhaust valve in the Reactor Building ventilation system during electrical switchgear inspections. The cause of the closure is still under investigation. The Control Room operators reopened the Reactor Building exhaust valve and pressure returned to within limits automatically. Secondary Containment was declared operable at 0802 PDT and TS Action Statement 3.6.4.1.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 NRC Resident Inspector has been notified. |
| ENS 49120 | 15 June 2013 18:38:00 | Columbia Generating Station is shutdown for a refueling outage and is currently in Mode 4. At 1222 PDT June 15, 2013, the 115 kV offsite power to the backup transformer relayed off and then came back on. Both Division 1 and Division 2 4.16 kV critical switchgear buses were powered from the backup transformer at the time of the loss of backup power. Upon detection of under voltage conditions, Emergency Diesel Generators 1 and 2 started and powered the Division 1 and Division 2 4.16 kV critical switchgear buses after approximately 5 seconds. The temporary loss of power to the Division 1 and Division 2 4.16 kV critical switchgear buses also resulted in the closure of containment isolation valves in the Reactor Water Cleanup System, Equipment Drain System and the Floor Drain System. Shutdown cooling had previously been secured in preparation of performing the reactor pressure vessel hydro test. Investigation into the cause of the temporary loss of the 115 kV offsite power is on-going. The Division 1 and Division 2 4.16 kV critical switchgear buses are currently being powered from the 230 kV offsite power through the startup transformer. There were no radiological releases as a result of this event." The licensee notified the NRC Resident Inspector. |
| ENS 45111 | 2 June 2009 00:54:00 | On 5/20/09, the Technical Support Center (TSC) air conditioning unit compressor failed to restart following refueling outage electrical bus maintenance. On 5/31/09, the compressor was discovered to be shorted to ground. The short renders the air conditioning unit nonfunctional and at 1650 on 6/1/09 the nonfunctional air conditioner was determined to adversely affect TSC habitability based on meteorological conditions. TSC filtration capabilities are not affected by this problem. The nonfunctional air conditioner leaves the TSC in a degraded state; however, the TSC is currently habitable and available for service. Should the TSC need to be activated, habitability of the TSC will be monitored per existing plant procedures. Relocation of the TSC to an alternate location would be performed in accordance with station procedures as necessary to ensure continued TSC functionality. The control room and all other emergency response facilities are unaffected by the TSC chiller outage. Work instructions to repair the chiller are in review and work is expected to commence on June 2nd and proceed with high priority. A follow-up notification will be made when the TSC chiller has been restored. This event is being reported as a loss of emergency preparedness capabilities in accordance with 10 CFR 50.72(b)(3)(xiii). The NRC resident has been notified.
Repairs to the TSC air conditioning unit have been completed and it has been placed in service. There is no longer any challenge to TSC habitability. The NRC Resident Inspector has been notified. R4DO (Cain) notified. |
| ENS 40959 | 15 August 2004 19:24:00 | With a reactor startup in progress at 1303 PDT, operators at Columbia Generating Station inserted a manual reactor scram when the running Reactor Feedwater (RFW-P-1A) pump tripped. Reactor power was approximately 18% at the time of RFW-P-1A trip. The cause of the RFW-P-1A trip was a high RFW Turbine Drain Tank (MD-TK-1) level; the cause of the MD-TK-1 high level is under investigation. The Reactor Core Isolation Cooling (RCIC) was used (manually started) to maintain reactor vessel water level until reactor pressure was reduced to within the capacity of the condensate booster pumps; the RCIC system has been returned to a standby lineup. The reactor is in mode 3 with both reactor recirculation pumps running at minimum speed (15 Hertz). Decay heat is being rejected to the main condenser via auxiliary steam loads. One control rod that indicated full-in immediately after the scram lost full-in indication eleven seconds after the scram. This control rod indicated full-in again 84 seconds after the scram. This ENS notification is made pursuant to 10 CFR 50.72(b)(2)(iv)(B). The licensee has notified the NRC Resident Inspector. |