05000219/LER-2013-003
| Oyster Creek, Unit 1 | |
| Event date: | 11-17-2013 |
|---|---|
| Report date: | 1-16-2014 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(C), Loss of Safety Function - Release of Radioactive Material |
| 2192013003R00 - NRC Website | |
Plant Conditions Prior To Event
Event Date: November 17, 2013 Event Time: 1725 EST Unit 1 Mode: Cold Shutdown Power Level: 0%
Description of Event
On 11/17/13 at 1725 EST station personnel simultaneously opened the inner and outer air lock doors from the Reactor Building to the reactor control enclosure (Reactor Building 23 foot elevation North West airlock). Reactor Building secondary containment integrity was momentarily declared inoperable per Technical Specification (TS) 3.5.B.2 due to both containment airlock doors being simultaneously open at the same time. Reactor Building D/P (differential pressure) remained less than negative 0.25 inches water column. The doors were immediately closed within 10 seconds and the Technical Specification condition was exited.
This event is being reported in accordance with 10 CFR 50.73(a)(2)(v)(C), any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.
Analysis of Event
The secondary containment interlock doors were open for less than ten seconds. Based upon the short duration of the secondary containment doors being opened simultaneously, individuals present in the airlock to close the doors and that the Reactor Building D/P remained less than negative 0.25 inches water column during the course of this event, the safety function was met and this event is of low safety significance.
Cause of Event
The primary causes for this event are ineffective use of visual aids provided by windows on airlock doors and a degraded airlock door interlock. Additionally, the door latch mechanism was found to have a worn lock solenoid.
Corrective Actions
Maintenance was performed to repair the degraded containment door interlock. An extent of condition walk down was performed to examine all other airlock doors. Site wide communications were made and signs are being added to provide additional instructions for airlock door operation.
Previous Occurrences
There have been no similar Licensee Event Reports associated with this component failure submitted at OCNGS in the last two years.
Component Data Components IEEE 805 System ID IEEE 803A Function Reactor Building NG IMEC