ENS 46680
ENS Event | |
|---|---|
05:45 Mar 18, 2011 | |
| Title | Control Room Boundary Rendered Inoperable |
| Event Description | On March 17, 2011 during a control room walk-down, it was discovered that a halon bottle located in the control room was removed from its associated piping for scheduled work. The open piping penetrates the control room boundary rendering it inoperable.
Technical Specification 3.7.6.1 'Control Room Emergency Ventilation System' is applicable in Modes 1, 2, 3, 4, 5 and 6 was entered. Since control room boundary was rendered inoperable, Dominion is reporting that this condition could have prevented the fulfillment of the safety function to mitigate the consequences of an accident. Upon discovery the piping was capped re-establishing the control room boundary. Further engineering review will be conducted to more fully evaluate the impact on the control room boundary. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). Offsite power is normal and all emergency diesel generators are operable. There was no increase in plant risk. The NRC Senior Resident Inspector has been notified.
The Licensee is retracting this report based on the following: On March 17, 2011 during a control room walk down at Millstone Power Station Unit 2, it was discovered that a halon bottle located in the control room was removed from its associated piping for scheduled work. Since the associated piping penetrates the control room boundary, operators declared the control room boundary inoperable. Upon discovery, the piping was capped re-establishing the control room boundary. Operators made a report in accordance with 10CFR50.72(b)(3)(v)(D). Subsequently, an engineering evaluation has been completed that concludes that the piping opening created by the removal of the halon bottle would not have prevented the fulfillment of the safety function to mitigate the consequences of an accident. Therefore, the condition reported in event report 46680 is being retracted. The NRC Resident Inspector has been notified. Notified R1DO (Powell). |
| Where | |
|---|---|
Millstone  Connecticut (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-0.22 h-0.00917 days <br />-0.00131 weeks <br />-3.01356e-4 months <br />) | |
| Opened: | Wayne Harrelson 05:32 Mar 18, 2011 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Mar 30, 2011 |
| 46680 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |