05000397/LER-2013-006
| Columbia Generating Station | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat |
| 3972013006R00 - NRC Website | |
PLANT CONDITIONS
The event occurred on June 27, 2013 at 17:58 hours when the plant was in Mode 1 at 62 percent power following a refueling outage.
EVENT DESCRIPTION
On June 27, 2013 at 17:58 hours a laborer was exiting the Diesel Generator [DG] 3 Room when he inadvertently brushed against the control switch [JS] for the Diesel Mixed Air fan [FAN] causing it to turn to the OFF position. In response to an annunciator in the main control room, an operations supervisor proceeded to the Diesel Generator 3 Room. After ascertaining what had happened by questioning the laborer, the operator turned the fan control switch back to the ON position. The Diesel Mixed Air fan was back in service at 18:19 hours, so the fan was inoperable for approximately 21 minutes. Technical Specifications were entered for the following equipment supported by the fan and declared inoperable: High Pressure Core Spray (HPCS) [BJ], Diesel Generator (DG-3) [DG], Division 3 125 VDC battery charger [BYC], Division 3 125 VDC battery [BTRY], and the Division 3 AC electrical power distribution system [JX]. The Diesel Mixed Air fan and its supported equipment and systems were declared operable at 18:19 hours and returned to service.
The event affected the safety function for a single train system, the High Pressure Core Spray (HPCS) system; therefore, this Licensee Event report is filed in accordance with 10 CFR 50.73(a)(2)(v)(B) and 50.73(a)(2)(v)(D). There were no radiological releases because of this event, and there were no system actuations or isolations as a result of the event.
IMMEDIATE CORRECTIVE ACTION
The proper control switch position was restored and the fan (DMA-FN-32) was placed back into service by Operations personnel.
CAUSE
The Cause Evaluation identified the apparent cause of this event as ineffective implementation of error prevention tools.
A contributing cause was identified as the station not having adequately addressed poor human factor designs In some cases for components susceptible to inadvertent contact due to their location and proximity in the plant.
FURTHER CORRECTIVE ACTION
Conduct a briefing with Site Support Contractor craft workers focusing on procedure PPM 1.3.81 (Maintaining Plant Component Status Control) requirements and supporting behaviors.
Perform plant walk-downs and compile a list of components that are susceptible to bumping and provide recommendations for additional actions to prevent bump incidents.
ASSESSMENT OF SAFETY CONSEQUENCES
The Diesel Mixed Air fan DMA-FN-32 functions as part of the DG-3 Engine Room ventilation supplying air flow to the room's air handling unit, and supports maintaining room air temperatures for diesel generator operation and for protection of electrical equipment. The fan serves the electrical equipment and generator area which are normally in standby. This HVAC component is required to ensure long-term emergency diesel generator and HPCS system operations. The HPCS system and Diesel Generator 3 were still available to respond to an accident condition. This event had no impact to the health and safety of the public.
26158 R5
SIMILAR EVENTS
There have not been similar event reports at the station in the last ten years.
ENERGY INDUSTRY IDENTIFICATION SYSTEM (eiis) INFORMATION CODES 26158 R5