ENS 47905
ENS Event | |
|---|---|
04:57 May 8, 2012 | |
| Title | |
| Event Description | On May 7, 2012, at 2357 CDT, with the plant in MODE 3 at normal operating temperature and pressure, leakage from a transmitter manifold test valve diaphragm seal was determined to be pressure boundary leakage per TS 3.4.13. The manifold test valve is associated with pressurizer pressure transmitter PT-430. It has been determined that the most likely cause of the leakage is a cracked manifold diaphragm and that this is classified as part of the Reactor Coolant System Pressure Boundary per 10 CFR 50.2.
This condition is being reported under 10 CFR 50.72(b)(3)(ii)(A) because the defect is associated with the Reactor Coolant Pressure Boundary. Isolation and repair of the leakage is being pursued. The licensee has notified the NRC Resident Inspector. The licensee closed the root isolation valves for the pressure transmitter to allow repair of the diaphragm, however there is still leakage past these valve. This leakage is quantified as a few drops per minute.
On May 8, 2012, EN #47905 provided notification of leakage from a pressurizer manifold valve that was potentially pressure boundary leakage. Since the leak could not quickly be determined to be otherwise, it was conservatively reported as pressure boundary leakage. Subsequent investigation and evaluation determined that the identified leakage originated from the mechanical components of the valve and not the pressure boundary. The leak has been isolated and the affected manifold valve is being repaired. Therefore, the leakage did not constitute pressure boundary leakage and this condition did not meet the reportability criteria identified in 10CFR50.72. As a result, the notification made on May 8, 2012 is hereby retracted. The NRC Resident Inspector has been notified. Notified R3DO (Giessner). |
| Where | |
|---|---|
Kewaunee  Wisconsin (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+3.32 h0.138 days <br />0.0198 weeks <br />0.00455 months <br />) | |
| Opened: | Mike Terry 08:16 May 8, 2012 |
| NRC Officer: | John Shoemaker |
| Last Updated: | May 8, 2012 |
| 47905 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Standby (0 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 479052012-05-08T04:57:0008 May 2012 04:57:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Pressure Boundary Leakage ENS 425342006-04-28T00:29:00028 April 2006 00:29:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Two Trains of Shield Building Ventilation Inoperable 2012-05-08T04:57:00 | |