ENS 51149
ENS Event | |
|---|---|
20:54 Jun 11, 2015 | |
| Title | Degraded Containment Spray Flow Check Valve |
| Event Description | During containment spray pump inservice testing the minimum flow recirculation line recorded negative flow indicating reverse flow in the line. After the troubleshooting, it was determined that a degraded minimum flow check valve was allowing a path to the refueling water storage tank (RWST) for certain post loss of coolant accident (LOCA) conditions. The minimum flow isolation has been closed to eliminate the path. No actuation occurred during this time.
The NRC Resident Inspector, Connecticut Department of Energy and Environmental Protection (DEEP) Hartford, and Watertown Dispatch have been notified.
The purpose of this call is to correct the record for the 10 CFR 50.72(b)(3)(v)(C) event report provided on June 11, 2015. Event report number 51149 states: 'During containment spray pump inservice testing ...' The condition of the degraded containment spray flow check valve was identified: 'During high pressure safety injection pump inservice testing...'." Notified R1DO (Bickett)
The purpose of this call is to update the record for the 10 CFR 50.72(b)(3)(v)(C) event report provided on June 11, 2015. During subsequent investigation, it has been determined that a second release path may have existed through ECCS system relief valves under certain post LOCA conditions as a result of the degraded check valve described in the original report. The licensee has informed the NRC Resident Inspector. Notified R1DO (Cahill). |
| Where | |
|---|---|
Millstone  Connecticut (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | |
| Time - Person (Reporting Time:+1.57 h0.0654 days <br />0.00935 weeks <br />0.00215 months <br />) | |
| Opened: | Angelo Leone 22:28 Jun 11, 2015 |
| NRC Officer: | Steven Vitto |
| Last Updated: | Jul 10, 2015 |
| 51149 - 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 51149\u003C/a\u003E - \u003Ca href=\"/Millstone\" title=\"Millstone\"\u003EMillstone\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EDegraded Containment Spray Flow Check Valve\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 51149 - Millstone\n","link":"","lat":41.310722222222225,"lon":-72.16767777777778,"icon":"/w/images/b/b0/Dominion_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |