ENS 53646
ENS Event | |
|---|---|
05:00 Oct 5, 2018 | |
| Title | En Revision Imported Date 10/25/2018 |
| Event Description | EN Revision Text: MAIN STEAM ISOLATION VALVES EXCEEDED PRIMARY CONTAINMENT LOCAL LEAK RATE ACCEPTANCE CRITERIA
At 0520 (CDT), on October 05, 2018, it was discovered that a Primary Containment local leak rate test performed on Main Steam Isolation Valves (MSIV) exceeded its acceptance criteria. During Mode 1, 2, and 3, Surveillance Requirement 3.6.1.3.10 requires MSIV leakage for a single MSIV line to be less than or equal to 106 standard cubic feet per hour (scfh) when tested at 29 psig and Surveillance Requirement 3.6.1.3.12 requires the combined leakage rate for all MSIV leakage paths to be less than or equal to 212 scfh when tested at 29 psig. As-found for the 'C' MSIV line leakage results were unquantifiable and gave a [minimum] path value greeter than 160 scfh. This leakage rate lead to Surveillance Requirement 3.6.1.3.10 and 3.6.1.3.12 limits to be exceeded. 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.
CNS [Cooper Nuclear Station] is retracting the 8-hour non-emergency notification made on October 5, 2018 at 0520 CDT (EN# 53646). Subsequent evaluation concluded that overall as-found 'C' MSIV leakage rate was not at a level that exceeded the surveillance requirement 3.6.1.3.10 and 3.6.1.3.12 limits and thus the Primary Containment Isolation Valve leakage rate limits for the MSIVs were not exceeded. The NRC Senior Resident Inspector has been notified. Notified the R4DO (Drake). |
| Where | |
|---|---|
Cooper  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+4.87 h0.203 days <br />0.029 weeks <br />0.00667 months <br />) | |
| Opened: | Terrell Higgins 09:52 Oct 5, 2018 |
| NRC Officer: | Vince Klco |
| Last Updated: | Oct 24, 2018 |
| 53646 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 53646\u003C/a\u003E - \u003Ca href=\"/Cooper\" title=\"Cooper\"\u003ECooper\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EEn Revision Imported Date 10/25/2018\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 53646 - Cooper\n","link":"","lat":40.359658333333336,"lon":-95.65465277777778,"icon":"/w/images/7/79/Entergy_icon.png"}],"imageoverlays":null} | |
WEEKMONTHYEARENS 536462018-10-05T05:00:0005 October 2018 05:00:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded En Revision Imported Date 10/25/2018 ENS 429392006-10-27T08:37:00027 October 2006 08:37:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Containment Pathway Declared Inoperable Following Local Leak Rate Testing 2018-10-05T05:00:00 | |