ENS 45013
ENS Event | |
|---|---|
09:00 Apr 22, 2009 | |
| Title | Discovery of After-The-Fact Emergency Condition - Alert - Due to Fire Damage to Safety-Related Breaker |
| Event Description | At 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br /> on April 23, 2009, it was identified that an ALERT classification had not been declared on April 22, 2009 as required by EPIP-1.01. North Anna Emergency Plan, Emergency Action Level H2.1 requires the declaration of an ALERT for a fire or explosion in any safe shutdown area and either plant personnel report visible damage to any safety-related structure, system or component within the area or affected system parameter indications show degraded performance. A description of the event is provided below.
On April 22, 2009, at approximately 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, Operations personnel identified a strong odor in the North Anna Unit 1 Cable Vault area. Subsequent investigation identified that the odor was coming from circuit breaker 01-EE-BKR-1J1-2S-J1 associated with the "D" Control Rod Drive Mechanism (CRDM) Fan (1-HV-F-37D). Operations personnel locally opened the circuit breaker to place it in a safe condition. 1-HV-F-37D had tripped approximately 30 minutes prior to the event. 1-HV-F-37D is not safety-related and not required for safe shutdown however; the supply breaker is safety-related since it is located on an emergency bus. Operation personnel then opened the circuit breaker cabinet and a small (6-inch) flame was observed. Operations personnel used a CO2 extinguisher on the internals of the circuit breaker to quickly extinguish the small fire. Appropriate levels of management were informed. The breaker has been quarantined. The cause of the circuit breaker failure has not been identified. A Root Cause Evaluation is in progress. There were no injuries. The plant continues to operate at full power. As a result of identifying that the criterion for the EAL was exceeded and no longer exists, a notification is being made to the NRC Operations Center in accordance with 10CFR50.72(a)(1)(i). The NRC Resident Inspector has been notified and the State and local governments will be notified.
On April 22, 2009, at approximately 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, operations personnel identified a strong odor in the North Anna Unit 1 Cable Vault area. Subsequent investigation identified that the odor was coming from circuit breaker 01-EE-BKR-1J1-2S-J1 associated with the 'D' Control Rod Drive Mechanism (CRDM) Fan (1-HV-F-37D). Operations personnel locally opened the circuit breaker to place it in a safe condition. 1-HV-F-37D had tripped approximately 30 minutes prior to the event. 1-HV-F-37D is not safety-related and not required for safe shutdown however; the supply breaker is safety-related since it is located on an emergency bus. Operation personnel then opened the circuit breaker cabinet and a small (6-inch) flame was observed. Operations personnel used a C02 extinguisher on the internals of the circuit breaker to quickly extinguish the small fire. A root cause evaluation is in progress. At 1447 hours0.0167 days <br />0.402 hours <br />0.00239 weeks <br />5.505835e-4 months <br /> on April 23, 2009, a one hour notification was made to the NRC Operations Center in accordance with 10CFR50.72(a)(1)(i), which identified that the criterion for a ALERT EAL was exceeded due to the small fire in the circuit breaker and subsequent damage to the breaker internals. The notification also stated that the condition no longer exists. Subsequent reviews have determined that the 'Initiating Condition' for the Emergency Action Level was not met and the event was not required to be classified as an ALERT. The initiating condition states -Fire or explosion affecting the operability of plant safety-related structures, systems or components required to establish or maintain safe shutdown. The 'D' Control Rod Drive Mechanism is not required to establish or maintain safe shutdown and the emergency bus remained operable during the event. The notification made to the NRC on April 23, 2009 is being retracted. The NRC Resident Inspector has been notified. Notified the R2DO (Nease). |
| Where | |
|---|---|
North Anna  Virginia (NRC Region 2) | |
| Reporting | |
| Other Unspec Reqmnt | |
| Time - Person (Reporting Time:+29.78 h1.241 days <br />0.177 weeks <br />0.0408 months <br />) | |
| Opened: | Page Kemp 14:47 Apr 23, 2009 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Jul 9, 2009 |
| 45013 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 474972011-12-05T13:47:0005 December 2011 13:47:00
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