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| Entered date | Event description | |
|---|---|---|
| ENS 45739 | 2 March 2010 18:48:00 | Wolf Creek experienced a reactor trip at 1458 CST. The first out annunciator was Steam Generator Level Lo Lo Reactor Trip. The trip was caused by the loss of the 'A' Main Feed Pump. The cause of the loss of the feed pump was due to the loss of 120 VAC non-safety instrument inverter PN09. PN09 supplies the Main Feed Pump Speed Control Circuitry. The loss of the PN09 also resulted in the loss of the ability to dump steam to the main condenser. Initial post trip decay heat was being removed with the Steam Generator Atmospheric Relief Valves and Auxiliary Feed Water. The Atmospheric Relief Valves cycled from approximately 1458 CST until approximately 1504 CST. Primary to Secondary leakage is less than 2.68 gallons per day. PN09 was re-energized at 1554 CST. All systems functioned as designed with the exception of the instrumentation powered by PN09. At the time of the trip the 'A' Emergency Diesel Generator and the 'A' Class IE Air Conditioning Unit were out of service for maintenance. The plant is being maintained at normal Mode 3 pressure and temperature. The reactor trip was uncomplicated and decay heat is currently being removed by steam dumps to the main condensers. The licensee has notified the NRC Senior Resident Inspector. |
| ENS 43396 | 31 May 2007 10:43:00 | At 02:10 am CDT Wolf Creek's surrounding area experienced a power loss when a fault occurred in the 69KV distribution system. Power was lost in the cities of Burlington, New Strawn and the surrounding area. Wolf Creek's emergency plan sirens are powered from substations fed from the 69 KV distribution system. Associated with this power loss, Wolf Creek initially lost power to seven (of 11 total) Emergency Sirens. Four of the sirens had power restored in approximately 5 minutes, the remaining three Emergency Sirens remained without power for greater than 2 hours. Power was restored to the area surrounding Wolf Creek at approximately 04:30 am CDT. The Coffey County Sheriff's office was kept informed of siren status in the event that they would need to make local notifications. Wolf Creek remained connected to the electrical grid through all three 345 KV lines during the loss of the 69 KV system. Coffey County, Kansas Department of Health and Environment, Kansas Department of Emergency Management and the Federal Emergency Management Agency Region 7 have been notified of the loss of sirens. The Wolf Creek Communications Group has physically verified that all sirens have been returned to service. The licensee notified the NRC Resident Inspector. |
| ENS 43394 | 29 May 2007 10:09:00 | On 05/29/2007 at 08:08 am CDT, the Wolf Creek Nuclear Plant Information System (NPIS) was removed from service for a planned computer system upgrade. The system upgrade will result in the SPDS and Emergency Response Data System (ERDS) being inoperable for approximately three weeks. Wolf Creek Nuclear Operating Corporation is making this ENS notification pursuant to the criteria of 10 CFR 50.72(b)(3)(xiii). There is no other loss of emergency assessment capability concurrent with the removal of the NPIS from service. Plant personnel entered the appropriate Off-Normal procedure and will obtain local readings for the equipment that is normally monitored by SPDS and NPIS during the plant computer upgrade. The Senior NRC Resident has been briefed on this evolution and the planned return to service of the system. * * * UPDATE FROM LANE TO SNYDER AT 1802 EDT ON 6/11/07 * * * On 06/09/07 at 18:46 CDT, the Wolf Creek Nuclear Plant Information System (NPIS) was returned to service following the computer upgrade. This restored the Safety Parameter Display System (SPDS) to OPERABLE and made the Emergency Response Data System (ERDS) available for use. The ERDS system will not be considered OPERABLE until testing has been performed with the NRC to confirm proper data transmissions. Some data points and processes are still being tested prior to being returned to service. The licensee notified the NRC Resident Inspector. Notified R4DO (M. Hay).
On 6/13/07 at 14:57 CDT (ERDS) testing with the NRC completed satisfactory to confirm proper data transmission. The licensee notified the NRC Resident Inspector. Notified R4DO(Hay). |
| ENS 43119 | 25 January 2007 15:38:00 | On 01/25/07 at 05:42am CT, the Wolf Creek Generating Station Nuclear Plant Information System (NPIS) computer 'C' primary and all backup MUX's failed. Subsequent troubleshooting failed to restore all primary MUX's to operation in a short period of time. The failure to restore the NPIS computer has resulted in a loss of functionality of the SPDS. Due to SPDS being lost for longer than a short period of time, Wolf Creek Nuclear Operating Corporation is making this ENS notification pursuant to the criteria of 10 CFR 50.72(b)(3)(xiii). There was no other loss of emergency assessment capability concurrent with the ongoing loss of SPDS. Plant personnel entered the appropriate Off-Normal procedure and obtained local readings for the equipment that is normally monitored by SPDS and NPIS during the loss of the plant computer. NPIS was restored to service and declared operable on the primary plant computer at 13:57 CT. The return of the NPIS computer to an operable condition restored the SPDS assessment capability function. The licensee notified the NRC Resident Inspector |
| ENS 41831 | 10 July 2005 01:20:00 | At 2154 hours on July 9, 2005, power was lost to the #11, Otter Creek and #12, Jacob's Creek Emergency Plan Sirens. At 2254 hours on July 9, 2005, the #11 and #12 sirens are still without power. Siren #4, WC Lake South, was previously determined to be inoperable at 1210 hours on July 6, 2005, due to being struck by lightning. With 3 of the 11 Emergency Plan sirens out of service for greater than 1 hour a major loss of emergency assessment capability exists. Lyon Coffey Electric is currently working to restore power to the #11 and #12 Emergency Plan sirens. The NRC Senior Resident Inspector has been notified. At 2359 hours power has been restored to the #11 and #12 sirens restoring emergency assessment capability. The licensee contacted the dispatcher at the LLEO as an informational call. |
| ENS 41327 | 12 January 2005 22:26:00 | The following information was received via facsimile from the licensee: Based upon information provided by Callaway on 1/12/05, it was determined that the manual pneumatic actuators on the Halon suppression systems are piped incorrectly which may result in the inability to actuate the Halon suppression systems manually or automatically. Each manual pneumatic actuator has clearly marked "A" and "B" ports. Per the M-658 vendor manual series & drawing M-658-00025, the "A" port shall be connected to the actuation pilot manifold or top of cylinder valve and the "B" port shall be connected to the solenoid valve. A field walk down was performed and in all but one case, the manual pneumatic actuator has been piped in the opposite configuration. This effects the Halon suppression system protecting the ESF switchgear rooms, the Rod Drive MG Set room, the North Electrical Penetration room, the South Electrical Penetration Room, the Switchgear & Switchboard rooms, and the Control Room cable trenches & chases. Based upon preliminary evaluation, it appears that the Halon suppression systems are inoperable. Fire watches were implemented for the affected areas. The licensee notified the NRC resident inspector.
This event report is retracted based on the following information provided from Wolf Creek by facsimile: Investigation - Informational tests conducted by the Vendor (Chemetron) and witnessed by Wolf Creek, Callaway, and NRC personnel on January 26, 2005 determined that the Halon systems would have properly actuated in the as-found incorrect configuration (port 'A' and 'B' connections reversed). The only identified difference in the actuation sequence between the tests conducted in the incorrect configuration versus the correct configuration is a delay of less than 2 seconds from the time the solenoid received the discharge signal until the first cylinder actuated. There is no regulatory or National Fire Protection Association standard or guideline that places a time requirement on this interval. This very slight time delay would have had no effect on the designed function of the Halon suppression system to extinguish a fire. Additional details are provided in the Chemetron report, "Report on Actuation Arrangements for Halon Extinguishing System Units," (Wolf Creek correspondence 05-00072) that includes the test procedure and results. Regulatory Evaluation - Guidance for reporting to the criterion of 10 CFR 50.73(a)(2)(ii) is provided in section 3.2.4 of NUREG 1022, "Event Reporting Guidelines 10 CFR50.72 and 50.73." This guidance states that an LER is required for a seriously degraded principal safety barrier or an unanalyzed condition that significantly degrades plant safety. Operating License Condition 2.C(5)(a) states the following: The Operating Corporation shall maintain in effect all provisions of the approved fire protection program as described in the SNUPPS Final Safety Analysis Report for the facility through Revision 17, the Wolf Creek site addendum through Revision 15, and as approved in the SER through Supplement 5, subject to provisions b & c below. Conclusion: - Based upon the information provided, the Halon suppression system would have operated to extinguish a fire. This condition is not considered reportable to the requirements of 10 CFR 50.72(b)(3)(ii)(B), 10 CFR 50.73(a)(2)(ii), nor is it a violation of the Operating License Condition 2.C(5)(a). Consistent with this conclusion, ENS notification number 41327 for this event is to be retracted. Notified R4DO (Whitten). NRC Resident Inspector will be notified. |