ENS 50874
ENS Event | |
|---|---|
19:21 Mar 9, 2015 | |
| Title | Tech Spec Required Shutdown Due to Swing Bus Automatic Throwover Failure |
| Event Description | While performing a Technical Specification surveillance functional test of the [Low Pressure Coolant Injection] LPCI swing bus automatic throwover scheme, the throwover function failed, rendering LPCI Loop Select inoperable. Time of [the] event was 1521 [EDT]. Inoperable LPCI Loop Select results in entry into Tech Spec 3.0.3. Power reduction activities were briefed and power reduction commenced at 1615. Maintenance is currently implementing a contingency work order to correct the auto throwover failure.
This report is made pursuant to 10 CFR 50.72(b)(2)(i), initiation of plant shutdown required by the plant's Technical Specifications; and 10 CFR 50.72(b)(3)(v)(D), an event or condition that could have prevented the fulfillment of the safety function of systems needed to mitigate the consequences of an accident. Offsite and Emergency power remain available. The NRC Resident Inspector was notified.
On March 9, 2015, at approximately 1521 [EDT], while performing a functional test of the LPCI swing bus automatic throwover scheme, the throwover function failed, rendering LPCI Loop Select inoperable. Tech Spec 3.0.3 was entered and power reduction commenced at 1615 [EDT]. Power was lowered to approximately 80%. Maintenance led a troubleshooting process that found and corrected the equipment problem. At approximately 2311 [EDT], the limiting condition for operating was cleared and LPCI Loop Select was declared operable. Tech Spec 3.0.3 was exited at that time. The licensee notified the NRC Resident Inspector. The plant has returned to 100% power. Notified R3DO (Orth).
The LCO and LPCI operability declared was at 2211 EDT NOT 2311 EDT. Notified R3DO (Orth). |
| Where | |
|---|---|
Fermi  Michigan (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-1.72 h-0.0717 days <br />-0.0102 weeks <br />-0.00236 months <br />) | |
| Opened: | S. Reith 17:38 Mar 9, 2015 |
| NRC Officer: | Jeff Herrera |
| Last Updated: | Mar 10, 2015 |
| 50874 - 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 50874\u003C/a\u003E - \u003Ca href=\"/Fermi\" title=\"Fermi\"\u003EFermi\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003ETech Spec Required Shutdown Due to Swing Bus Automatic Throwover Failure\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 50874 - Fermi\n","link":"","lat":41.96295277777778,"lon":-83.25779444444444,"icon":"/w/images/5/5b/DTE_Energy_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (83 %) |