ENS Event | |
|---|---|
19:31 Nov 3, 2021 | |
| Title | Incorrect Local Leak Rate |
| Event Description | On 11/03/2021 Columbia Generating Station concluded the results for refueling outage 24 (R24) and 25 (R25) Local Leak Rate Testing as-found data was incorrect.
At 1231 PDT on November 3rd, 2021 Columbia Generating Station determined the local leak rate tests (LLRT) for the X- 25B containment penetration did not meet Technical Specification requirements for LLRT acceptance criteria. The incorrect LLRT data identified for residual heat removal (RHR) B Suppression Pool Spray containment isolation valve (RHR-V-27B) was from the previous two refueling outages (R24 on 5/22/2019 & R25 on 6/512021) at which time primary containment was not required to be operable. The corrected leakage assigned to the X-25 penetration also resulted in total Type B and C leakage summation exceeding the maximum allowable leakage rate for the primary containment (1.0 La) for R24 and exceeding 0.6La in R25. The valve was flushed and retested satisfactory prior to entering the mode of applicability. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Columbia  Washington (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| LER: | 05000397/LER-2021-002 Integrated Leak Rate Test 05000397/LER-2021-002-01 Integrated Leak Rate Test |
| Time - Person (Reporting Time:+-1.43 h-0.0596 days <br />-0.00851 weeks <br />-0.00196 months <br />) | |
| Opened: | Quoc Vo 18:05 Nov 3, 2021 |
| NRC Officer: | Thomas Kendzia |
| Last Updated: | Nov 3, 2021 |
| 55560 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 576632025-04-12T09:23:00012 April 2025 09:23:00
[Table view]10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Shutdown Required by Technical Specifications ENS 555602021-11-03T19:31:0003 November 2021 19:31:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Incorrect Local Leak Rate ENS 524432016-12-19T07:20:00019 December 2016 07:20:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Unisolable Leak on High Pressure Core Spray ENS 451312009-06-13T18:30:00013 June 2009 18:30:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Reactor Coolant Pressure Boundary Leak 2025-04-12T09:23:00 | |