ENS 53476
ENS Event | |
|---|---|
05:00 Jun 26, 2018 | |
| Title | En Revision Imported Date 8/14/2018 |
| Event Description | EN Revision Text: CONTROL ROOM EMERGENCY FILTRATION SYSTEM DECLARED INOPERABLE
On June 26, 2018, at 1630 CDT, the Control Room Emergency Filtration System (CREFS) was declared inoperable when Main Control Room Supply Fan SF-C-1B was discovered to have elevated vibrations that brought into question the ability to meet its mission time. CREFS is a single train safety system. Per 10 CFR 50.72(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 a safety function of an SSC [System Structure or Component] that is required to mitigate the consequences of an accident. The licensee has notified the NRC Senior Resident Inspector.
The following retraction was received from Cooper Nuclear Station (CNS) via facsimile and phone call: CNS is retracting the 8-hour non-emergency notification made on June 26, 2018 at 1630 CDT (EN# 53476). Subsequent evaluation concluded that overall vibration levels were not at a level that would impact the ability of the Main Control Room Supply Fan SF-C-18 to perform its safety function for its required mission time and the CREFS therefore, was operable. The NRC Senior Resident Inspector has been notified. Notified the R4DO (Deese). |
| 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:+18.48 h0.77 days <br />0.11 weeks <br />0.0253 months <br />) | |
| Opened: | Randy Kouba 23:29 Jun 26, 2018 |
| NRC Officer: | Andrew Waugh |
| Last Updated: | Aug 13, 2018 |
| 53476 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |