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| Entered date | Event description | |
|---|---|---|
| ENS 48649 | 3 January 2013 17:32:00 | On 01/03/13 at 0604 CST, the Wolf Creek Generating Station Nuclear Plant Information System (NPIS) computer was removed from service for scheduled maintenance. The NPIS computer being removed from service results 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. When the equipment was removed from service, 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 computer was restored to service and declared functional at 1541 CST. The return of the NPIS computer to a functional condition restored the SPDS assessment capability function. The licensee notified the NRC Resident Inspector. |
| ENS 42603 | 24 May 2006 16:46:00 | While performing a post-fire safe shutdown area review for fire area C-35, it was discovered that a design basis fire in this area could prevent operation of both Class 1E Electrical Equipment air-conditioning units (SGK05A and SGK05B). The Class 1E Electrical Equipment air conditioning units provide temperature control for equipment required for safe shutdown in the Class 1E switchgear rooms (ESF switchgear rooms, DC switchgear rooms, and NK battery rooms). A fire in fire area C-35 could impact fire protection panel KC230 and cables associated with the automatic shutdown feature for the air conditioning units. The automatic shutdown feature normally operates whenever a fire occurs in any of the Class 1E switchgear rooms prior to Halon fire suppression operation. A fire in fire area C-35 could result in the inability to operate the air conditioning units and provide the necessary temperature control for equipment required for safe shutdown. Compensatory measures: a continuous fire watch was established for fire area C-35, a temporary procedure change will be completed to allow use of a jumper to restore Class 1E air conditioning unit (SGK05A) to service, if required, at which time the continuous fire watch will be changed to an hourly watch. The licensee notified the NRC Resident Inspector. |
| ENS 42146 | 16 November 2005 18:56:00 | After a timed walk down of an Off Normal Operations procedure for shut down outside the Control Room, it appears that required response times were not met. This is due to a new assumption that all actions would not function due to plant configuration. Some valve circuits are not protected with a second fuse that is isolated from the control room portion of the circuitry. The only fuse in the circuit may blow during the early part of the event, prior to manipulating the isolation switch on the breaker. Since the fuse could blow, there would be no control power to electrically manipulate the valve and that would cause the operator to go to the 'Response not Obtained' column adding time to the actions taken. This issue was previously identified at Wolf Creek in 1985 in IE INFORMATION NOTICE NO. 85-09. However, additional research needs to be accomplished as to why some circuits have only one fuse. Compensatory actions include: 1) A change to the procedure to direct additional actions. 2) An hourly fire watch has been added to the control room. The licensee notified the NRC Resident Inspector. |
| ENS 41509 | 21 March 2005 18:25:00 | The following information was provided by the licensee On 3-21-05 the Plant Computer system was removed from service at 0753 for scheduled maintenance. The system was not verified restored until 1558. This is in excess of the eight hours allowed by 10CFR50.72(b)(3)(xiii). The Plant Computer system supplies the Safety Parameter Display System (SPDS) function, which is required for Emergency Assessment Capability. The Plant Computer is currently operable. This event did not effect the plant operations. The unit is stable in Mode 1 at 100% power. The NRC Resident inspector has been informed. |