ENS 52750
ENS Event | |
|---|---|
05:45 May 12, 2017 | |
| Title | Main Steam Isolation Valves Exceeded Primary Containment Local Leak Rate Acceptance Criteria |
| Event Description | At 0045 [CDT] on May 12, 2017, it was discovered that a Primary Containment local leak rate test performed on Main Steam Isolation Valves (MSIV) exceeded its acceptance criteria.
During Modes 1, 2, and 3, Technical Specification Surveillance Requirement 3.6.1.3.9 requires MSIV leakage for a single MSIV line to be less than or equal to 100 standard cubic feet per hour (scfh) (47,195 sccm) and requires the combined leakage rate for all MSIV leakage paths to be less than or equal to 200 scfh (94,390 sccm) when tested at 9 psig. As-found for the 'D' MSIV line leakage is 53,921.61 standard cubic centimeter per minute (sccm) for the 'D' Inboard MSIV 1B21F022D and 59,698.8 sccm for the 'D' Outboard MSIV 1B21F028D. As-found combined MSIV min-path leakage is 102,463 sccm. This event is being reported as a condition of the nuclear power plant, including its principal safety barriers, being seriously degraded per 10 CFR 50.72(b)(3)(ii)(A) since the Primary Containment Isolation Valves leakage limits for MSIVs were exceeded. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Clinton  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+2.58 h0.108 days <br />0.0154 weeks <br />0.00353 months <br />) | |
| Opened: | Robert Rush 08:20 May 12, 2017 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | May 12, 2017 |
| 52750 - NRC Website
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WEEKMONTHYEARENS 533032018-03-30T18:05:00030 March 2018 18:05:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Primary Containment Declared Inoperable Due to Both Airlock Doors Open Simultaneously ENS 527502017-05-12T05:45:00012 May 2017 05:45:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Main Steam Isolation Valves Exceeded Primary Containment Local Leak Rate Acceptance Criteria ENS 519392016-05-17T14:45:00017 May 2016 14:45:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Reactor Coolant Leakage with the Reactor in Cold Shutdown ENS 456762010-02-03T17:00:0003 February 2010 17:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Feedwater Check Valve Leak Rate Exceeded Technical Specification Requirement ENS 434302007-06-19T11:35:00019 June 2007 11:35:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Tech Spec Required Shutdown Due to Instrument Line Steam Leak 2018-03-30T18:05:00 | |