ENS 43633
ENS Event | |
|---|---|
19:39 Sep 11, 2007 | |
| Title | Auxiliary Building Special Ventilation and Shield Building Ventilation Systems Inoperable |
| Event Description | At 1439 the Control Room received a Condition Report that identified an unanalyzed condition associated with the Auxiliary Building Special Ventilation and Shield Building Ventilation Systems which resulted in declaring this equipment inoperable. The issue was recirculation flow from Auxiliary Building Special Ventilation back to the Auxiliary Building added additional area heat gain resulting in exceeding the design capacity for the area fan coil units. Technical Specification LCO was entered per TS 3.6.c requiring a reactor shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. At 1654 Engineering provided information that if the control switch for Auxiliary Building Special Ventilation Train A was maintained in the off position, the area heat load was within the capacity of area fan coil units. This was completed and both trains of Shield Building Ventilation and Auxiliary Building Special Ventilation Train B was returned to operable. Technical Specification requirements to shutdown were exited. The plant remains in a 7 day Action Statement per TS 3.6.c with Auxiliary Building Special Ventilation Train A inoperable.
This event is reportable under 10CFR50.72(b)(3)(v)(C), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The licensee notified the NRC Resident Inspector.
On September 11, 2007 Kewaunee Power Station reported an unanalyzed condition associated with the Auxiliary Building Special Ventilation and Shield Building Ventilation Systems, which resulted in declaring the equipment inoperable. The issue involved recirculation flow from the Auxiliary Building Special Ventilation System back into the Auxiliary Building causing additional area heat gain resulting in exceeding the design capacity for the area fan coil units. A subsequent engineering review concluded that required equipment in the Auxiliary Building Fan Floor area would have remained functional during a design basis accident provided service water temperature does not exceed 78.14 degrees Fahrenheit. A review of service water temperatures over the past three years did not identify any occurrences exceeding this value. Therefore, the safety function of the systems would have been met. Based on the analysis performed, Event Notification EN 43633 is hereby retracted. The Auxiliary Building Special Ventilation and Shield Building Ventilation Systems remain in a non-conforming condition because the maximum service water design temperature is 80 degrees Fahrenheit. Service water temperature is being administratively limited to 71 degrees Fahrenheit pending final corrective action. The licensee has notified the Point Beach NRC Senior Resident Inspector. Notified R3DO (Madera). |
| Where | |
|---|---|
Kewaunee  Wisconsin (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | |
| Time - Person (Reporting Time:+0.9 h0.0375 days <br />0.00536 weeks <br />0.00123 months <br />) | |
| Opened: | Tim Bunkelman 20:33 Sep 11, 2007 |
| NRC Officer: | Jason Kozal |
| Last Updated: | Oct 30, 2007 |
| 43633 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |