ENS Event | |
|---|---|
17:25 Nov 1, 2017 | |
| Title | Unit 2 Failed Llrt Surveillance Test Due to Excessive Leakage |
| Event Description | On November 1, 2017 at 1225 CDT, both the 2-220-58A Feed Water Inboard Check Valve and the 2-220-62A Feed Water Outboard Check Valve failed Local Leak Rate Testing (LLRT) acceptance criteria due to excessive leakage. These valves are considered primary containment isolation valves, and as such, are required to ensure that an adequate primary containment boundary is maintained.
Technical Specification (TS) 5.5.12, 'Primary Containment Leakage Rate Testing Program,' establishes limits for Primary Containment leakage. Based upon the results of the LLRT, Dresden, Unit 2, may not have met the limits for primary containment leakage during the last operating cycle as specified in TS 5.5.12.C. Dresden Unit 2 is currently in Mode 5 for a refueling outage and per Dresden TS 3.6.1.1, 'Primary Containment,' Primary Containment is not required in the current mode of operation (i.e., Mode 5). However, in accordance with 10 CFR 50.72(b)(3)(ii)(A), this event is reportable as a condition that resulted in a principal safety barrier being seriously degraded. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Dresden  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+-0.87 h-0.0363 days <br />-0.00518 weeks <br />-0.00119 months <br />) | |
| Opened: | Michael Csermak 16:33 Nov 1, 2017 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Nov 1, 2017 |
| 53048 - NRC Website
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WEEKMONTHYEARENS 530482017-11-01T17:25:0001 November 2017 17:25:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Unit 2 Failed Llrt Surveillance Test Due to Excessive Leakage ENS 495852013-11-26T20:00:00026 November 2013 20:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Leakage Discovered on Electromatic Relief Valve During Hydrostatic Testing ENS 495352013-11-14T09:00:00014 November 2013 09:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Primary Containment Isolation Valve Leak Test Failure ENS 454752009-11-03T11:09:0003 November 2009 11:09:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Weld Issue ENS 455612009-11-03T06:00:0003 November 2009 06:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Instrument Line Determined to Have Inadequate Structural Support 2017-11-01T17:25:00 | |