ENS 48924
ENS Event | |
|---|---|
02:16 Apr 15, 2013 | |
| Title | Primary Containment Air Lock Failed Integrated Leak Rate Test |
| Event Description | On Sunday, April 14, 2013 at 2216 hours0.0256 days <br />0.616 hours <br />0.00366 weeks <br />8.43188e-4 months <br />, with the Pilgrim Nuclear Power Station (PNPS) Reactor Mode Select Switch (RMSS) in Start-up, the turbine generator previously removed from service, and the reactor sub-critical on Intermediate Range Monitors Range 2 and lowering, the PNPS Containment Personnel Air Lock failed integrated air lock testing as required by TS 4.7.A.2.
10CFR50 Appendix J requires that primary reactor containment meet certain leakage rate testing requirements. These test requirements ensure that 1) Leakage through the containment or systems and components penetrating the containment do not exceed allowable leakage rates specified in Technical Specifications and 2) The integrity of the containment structure is maintained during its service life. The test requirements include local leakage rate testing of containment air locks. The test criteria establishes a limit of less than or equal to 10.525 SLM, actual leakage was 16.7 SLM. PNPS was in the process of shutting down for a scheduled Refueling Outage during the scheduled testing. This event had no impact on the health and/or safety of the public. The USNRC Resident Inspector will be notified. This 8-hour notification is being made in accordance with 10CFR50.72(b)(3)(v)(c).
Subsequent investigation of the test failure determined that an o-ring in the Airlock Inner Pressure Equalizing Device (PED) was not properly seated resulting in exceeding the established leakage rate limit. Leakage was not observed on the Airlock Outer Boundary Surface. Thus, with the Airlock Outer Boundary Surface intact, the Airlock was capable of performing the safety function to control the release of radioactive material. In addition, even with the Airlock leakage of 16.7 standard liters per minute (SLM), the Technical Specification Primary Containment As-Found Minimum Pathway Leakage Limit of 0.6 La for all Type B and C leakage tests was not exceeded. Therefore, the initial 50.72(b)(3)(v)(C) report is being retracted. The licensee will notify the NRC Resident Inspector. Notified R1DO (Dentel). |
| Where | |
|---|---|
| Pilgrim Massachusetts (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | |
| Time - Person (Reporting Time:+3.8 h0.158 days <br />0.0226 weeks <br />0.00521 months <br />) | |
| Opened: | Michael Mcdonnell 06:04 Apr 15, 2013 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Jun 13, 2013 |
| 48924 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Shutdown (0 %) |
| After | Hot Shutdown (0 %) |