ENS 52413
ENS Event | |
|---|---|
22:19 Oct 17, 2016 | |
| Title | Invalid Engineered Safety Features Actuation System (Esfas) Signal |
| 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 10CFR50.73.
This telephone notification is being made pursuant to the reporting requirements of 10 CFR 50.73(a)(2)(iv)(A) and 50.73(a)(1) to describe an invalid actuation of the Palo Verde Nuclear Generating Station (PVNGS) Unit 1 train A emergency diesel generator (EDG), train A high pressure safety injection (HPSI) pump, and train A essential spray pond (SP) pump. These components are portions of the emergency ac electrical power system, the emergency core cooling system, and the emergency service water system, respectively, as described in 10 CFR 50.73(a)(2)(iv)(B). On October 17, 2016 at approximately 1519, Mountain Standard Time, a portion of the Unit 1 train A engineered safety features equipment was automatically started by the balance-of-plant (BOP) engineered safety features actuation system (ESFAS) while the plant was at steady state conditions. Initiation of the train A ESFAS actuation signal was momentary, and the ESFAS actuation signal cleared 0.2 seconds after being initiated. The invalid ESFAS signal initiated a test-mode start signal for the train A EDG and started the train A HPSI pump. The train A essential SP pump started in support of the train A EDG. All actuated components started and functioned successfully. No systems started in response to actual plant conditions, and no actuation was required to mitigate the consequences of an event. The invalid HPSI actuation neither resulted in an emergency core cooling system discharge, nor should it have. The invalid actuation was the consequence of a spurious momentary signal into the BOP-ESFAS control panel due to an intermittent high resistance electrical connection. The event was entered into the PVNGS corrective action program. There were no adverse impacts to public health and safety nor to plant employees. The NRC Resident Inspectors have been informed. |
| Where | |
|---|---|
Palo Verde  Arizona (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1217.67 h50.736 days <br />7.248 weeks <br />1.668 months <br />) | |
| Opened: | Robert Chu 16:59 Dec 7, 2016 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Dec 7, 2016 |
| 52413 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
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 | |