ENS 49807
ENS Event | |
|---|---|
03:11 Dec 12, 2013 | |
| Title | 60 Day Report for an Invalid Main Steam Line Actuation |
| Event Description | The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10 CFR 50.73.
This telephone notification is being made pursuant to the reporting requirements of 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation of the Palo Verde Nuclear Generating Station Unit 2 'A' train Main Steam and Feedwater Isolation System (MSFIS) logic. On December 11, 2013, at approximately 2011, Mountain Standard Time, Unit 2 was shut down in Mode 4 with Reactor Coolant System (RCS) temperature at approximately 425 degrees Fahrenheit and 1900 pounds per square inch absolute. While starting up the plant following completion of repairs to the 1A reactor coolant pump, an invalid actuation of the 'A' train MSFIS fast close logic occurred due to a random electrical failure in the 'A' train MSFIS logic cabinet. This resulted in the closure of all four Main Steam Isolation Valves and the two 'A' train Economizer Feed Water Isolation Valves. No other engineered safety feature actuations occurred and none were required. The invalid actuation was initiated by a ground fault in a 30-volt direct current power supply in the 'A' train MSFIS Logic cabinet. Repairs were completed on December 12, 2013. This was a complete actuation of 'A' train MSFIS equipment and all the affected equipment responded as designed. RCS temperature and pressure were maintained stable using atmospheric dump valves. Feed water to the steam generators was being provided by Auxiliary Feed Water and was not affected by the event. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Palo Verde  Arizona (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1381.33 h57.555 days <br />8.222 weeks <br />1.892 months <br />) | |
| Opened: | Sean Dornseif 16:31 Feb 7, 2014 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Feb 7, 2014 |
| 49807 - 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 49807\u003C/a\u003E - \u003Ca href=\"/Palo_Verde\" title=\"Palo Verde\"\u003EPalo Verde\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E60 Day Report for an Invalid Main Steam Line Actuation\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 49807 - Palo Verde\n","link":"","lat":33.386894444444444,"lon":-112.86263333333333,"icon":"/w/images/9/93/Arizona_Public_Service_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Shutdown (0 %) |
| After | Hot Shutdown (0 %) |
WEEKMONTHYEARENS 559262022-04-12T03:45:00012 April 2022 03:45:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation ENS 550322020-12-11T07:00:00011 December 2020 07:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Option Telephonic Notification of an Invalid Specified System Actuation ENS 547012020-03-14T19:44:00014 March 2020 19:44:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Spray Pond Pump System - 60 Day Reports ENS 524132016-10-17T22:19:00017 October 2016 22:19:00 10 CFR 50.73(a)(1), Submit an LER Invalid Engineered Safety Features Actuation System (Esfas) Signal ENS 522282016-07-12T12:50:00012 July 2016 12:50:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Both Trains Essential Spray Pond System ENS 498072013-12-12T03:11:00012 December 2013 03:11:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Report for an Invalid Main Steam Line Actuation ENS 486152012-10-26T04:08:00026 October 2012 04:08:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Actuation of the Essential Spray Pond System ENS 468982011-04-03T21:44:0003 April 2011 21:44:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Notification of Invalid Start of the 'A' Emergency Diesel Generator ENS 427342006-06-06T01:44:0006 June 2006 01:44:00 10 CFR 50.73(a)(1), Submit an LER Invalid Emergency Diesel Generator Start ENS 418042005-04-29T07:43:00029 April 2005 07:43:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation 2022-04-12T03:45:00 | |