ENS 43823
ENS Event | |
|---|---|
02:51 Dec 4, 2007 | |
| Title | Accident Mitigation - Crefs Inoperable |
| Event Description | On 03 DEC 07 at 2051, following a review of notification CR-CNS-2007-08237 [written for a degraded condition on the field wiring on the motor for HV-FAN-BF-C-1B - the control room HVAC exhaust booster fan, and a physical inspection of the motor itself], it was determined that reasonable assurance that CREFS would fulfill its safety function could not be established.
The CREFS system was inoperable at the time for the purpose of planned maintenance and the condition was discovered during the performance of that planned maintenance. HV-FAN-BF-C-1B is normally in operation at all times and was operating prior to being secured for the planned CREFS maintenance window. This fan is a required support feature for the control room emergency filtration system (CREFS) at CNS. This is a single train system and per 10CFR50.72(b)(3)(v)(D) an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> report is required due to the fact that at the time of discovery this condition could have prevented the fulfillment of the safety function of an SSC that is required to mitigate the consequences of an accident. The licensee is in a 7 day shutdown LCO 3.7.4 Condition A. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Cooper  Nebraska (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:+-3.33 h-0.139 days <br />-0.0198 weeks <br />-0.00456 months <br />) | |
| Opened: | Fred Schizas 23:31 Dec 3, 2007 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Dec 3, 2007 |
| 43823 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |