ENS 51808
ENS Event | |
|---|---|
22:10 Mar 19, 2016 | |
| Title | Unanalyzed Condition That Could Challenge Rhr Equipment During Flood Conditions |
| Event Description | Two (2) potentially degraded flood barriers at penetrations 0073-01-0034 and 0073-01-0063 were identified in the area between the Unit 1 Turbine Building and Auxiliary Building. The deficient barriers are a 'blockout section' of the floor designed to house multiple penetrations that transition from the Turbine Building to the Auxiliary Building. Attempts have been made to investigate the status of the flood barrier with no definitive results. Investigations and additional evaluations are continuing, however, it is currently unknown if the aggregate of these two flood barriers could potentially overwhelm and flood the Auxiliary Building which would challenge equipment necessary to remove residual heat and constitute an unanalyzed condition.
Based on current conditions (i.e., no forecast flooding conditions), this condition does not present an immediate safety concern. This condition has been determined to be reportable per 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(v)(B). This condition is a non-emergency condition. This condition has been entered into the Corrective Action Program. Compensatory measures have been prepared to allow placement of a seal over the identified deficient barriers. If required these seals can be installed well in advance of forecast flood conditions. Permanent repairs are currently being designed for installation. The NRC Resident Inspector has been notified.
This is an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> non-emergency supplemental notification to previously issued Event Notification 51808. In EN 51808, two non-functional barriers were identified and reported, and during an extent of condition review, a third barrier has been identified that does not conform to expected flood barrier standards A potentially degraded flood barrier at 'blockout' penetration 0073-01-9018 was identified in the area between the Unit 1 Turbine Building and Auxiliary Building. The deficient barrier is a 'blockout section' of the floor designed to house multiple penetrations that transition from the Turbine Building to the Auxiliary Building. Attempts have been made to investigate the status of the flood barrier with no definitive results. Investigations and additional evaluations are continuing; however, it is currently unknown if this flood barrier could potentially be overwhelmed and flood the Auxiliary Building which would challenge equipment necessary to remove residual heat and constitute an unanalyzed condition. Based on current conditions (i.e., no forecast flooding conditions), this condition does not present an immediate safety concern. This condition has been determined to be reportable per 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(v)(B). This condition is a non-emergency condition. This condition has been entered into the Corrective Action Program. Compensatory measures have been prepared to allow placement of a seal over the identified deficient barrier. If required this seal can be installed well in advance of forecast flood conditions. Permanent repairs are currently being designed for installation. The NRC Resident Inspector was notified earlier in the evening that this event would be updated. Notified the R4DO (Haire). |
| Where | |
|---|---|
Arkansas Nuclear  Arkansas (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat | |
| Time - Person (Reporting Time:+0.68 h0.0283 days <br />0.00405 weeks <br />9.31464e-4 months <br />) | |
| Opened: | Rodrick Johnson 22:51 Mar 19, 2016 |
| NRC Officer: | Steven Vitto |
| Last Updated: | Mar 22, 2016 |
| 51808 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |