ENS 40950
ENS Event | |
|---|---|
15:30 Aug 13, 2004 | |
| Title | Control Room Emergency Zone Boundary Outside Design Basis |
| Event Description | On 08/13/2004 at 1030 CDT the Kewaunee Shift Manager was notified the control room emergency zone (CREZ) boundary was outside assumed design basis for an unknown amount of time. This is an eight hour non-emergency reportable under 10 CFR 50.72(b)(3)(v)(D), Accident Mitigation.
On 08/12/2004 at 1915 [CDT], the local operator reported to the control room that he found a control room emergency zone (CREZ) boundary door in the unlatched open position. The local operator immediately ensured the door was secured in the latched closed position. Per Kewaunee's barrier control procedure the Shift Manager requested an evaluation be performed to determine the impact of potential air in leakage on the control room post accident dose consequences. On 08/13/2004 at 1030 CDT, the engineering staff reported that based on engineering judgment the unfiltered in leakage that could have entered the CREZ would likely exceed that assumed in the post accident dose analysis. Based on this judgment, the in leakage would have prevented the Control Room Post Accident Recirculation System from mitigating the dose consequences to the control room staff to values less than those determined in accident analysis. At the time of discovery the local operator immediately secured the boundary door rendering the CREZ boundary operable. This event has been entered in the Kewaunee corrective action process to investigate the cause of the door being in the open position. No other safety related equipment was out of service at the time of discovery. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Kewaunee  Wisconsin (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-0.12 h-0.005 days <br />-7.142857e-4 weeks <br />-1.64376e-4 months <br />) | |
| Opened: | Bradly J Mcmahon 15:23 Aug 13, 2004 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Aug 13, 2004 |
| 40950 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |