ENS 50744
ENS Event | |
|---|---|
17:00 Jan 19, 2015 | |
| Title | Missile Door Misaligned Results in a Reduction in Accident Mitigation |
| Event Description | The missile door (door 33012) protecting Class 1E Engineered Safety Features (ESF) buses NB01/NB02 switchgear rooms was discovered misaligned on its hinge and stuck partially open and not capable of being closed. The missile door has since been repaired and closed. Technical Specification (TS) 3.8.9, 'Distribution Systems- Operating,' was declared not met and Condition F entered when the immediate operability determination identified that buses NB01 and NB02 were inoperable. Condition F of TS 3.8.9 requires immediate entry into Limiting Condition for Operation (LCO) 3.0.3. LCO 3.0.3 was entered at 1100 CST and subsequently exited when the missile door was repaired at 1118 CST. The unit was in and still is in MODE 1 at 100% power. No actions were initiated to commence a unit shut down. The NRC resident inspector was contacted regarding this event. All systems functioned as expected.
The licensee is retracting this event based on the following: An engineering evaluation concluded that the weather conditions during the period of the event did not result in the threat of a tornado. Given that the weather during the event would not have presented a valid threat of a tornado, the stuck open missile door would not have prevented the ESF busses and the DGs [Diesel Generators] from performing their specified safety function. The ESF busses and the DGs were considered OPERABLE but degraded. This is analogous to Example 4 in RIS 2001-09, 'Control of Hazard Barriers', with the exception that this event did not occur as a result of planned maintenance or a plant modification. As such, this event has been determined to not be reportable per 10 CFR 50.72(b)(3)(v)(D). The licensee has notified the NRC Resident Inspector. Notified R4DO (Gepford). |
| Where | |
|---|---|
Wolf Creek  Kansas (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-2.6 h-0.108 days <br />-0.0155 weeks <br />-0.00356 months <br />) | |
| Opened: | Pierce C. Moore 14:24 Jan 19, 2015 |
| NRC Officer: | Vince Klco |
| Last Updated: | Mar 16, 2015 |
| 50744 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |