ENS 49179
ENS Event | |
|---|---|
05:41 May 10, 2013 | |
| Title | 60 Day Optional Telephonic Notification of Invalid Actuation of an Emergency Diesel Generator |
| Event Description | This 60-day telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report an invalid actuation of the Emergency Diesel Generators (EDGs) reportable under 10 CFR 50.73(a)(2)(iv)(A).
On the morning of May 10th, 2013, at approximately 0141 EDT the B Emergency Diesel Generator (EDG) subsystem was inoperable for a planned maintenance work window on the B EDG only (there are two EDGs per subsystem). The work was completed to the point that protective tagging removal and testing of the B EDG were the only activities left. During the process of removing protective tagging, an operator incorrectly opened a switch-gear cubicle door that contained the potential transformer fuses for the B division emergency electrical bus (10600 bus); the system is designed such that opening the cubicle door disconnects the fuses from the circuit. The potential transformers reduce the associated bus voltage (in this case the 10600 bus), nominally 4160V, to 120V for the monitoring and control circuits. These circuits monitor the 10600 bus voltage and initiate a start signal for the EDGs should voltage be degraded or lost. After a time delay of less than or equal to 2.5 seconds, if voltage is not restored, the normal supply breaker for the 10600 bus will open and the EDG output breakers will close re-powering the bus from its emergency source. The response of the 10600 bus control and monitoring circuits functioned as designed. An initiation signal was sent to the D EDG control system when the monitoring circuit sensed no bus voltage (potential transformer fuses removed; door open). With the immediate closure of the cubicle door, the monitoring circuit was restored and 10600 bus voltage was sensed. This resulted in the under voltage logic returning to normal hence, the 10600 bus did not disconnect from its normal station power source and the D EDG output breaker did not close to power the 10600 bus. Subsequently the D EDG was secured (0146 EDT on May 10th) and protective tagging removal and testing of B EDG continued. The B EDG subsystem was declared operable on May 12, 2013 at 0315 EDT. This event did not result in any adverse impact to the health and safety of the public. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Fitzpatrick  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1424.5 h59.354 days <br />8.479 weeks <br />1.951 months <br />) | |
| Opened: | Chris Adner 14:11 Jul 8, 2013 |
| NRC Officer: | Daniel Mills |
| Last Updated: | Jul 8, 2013 |
| 49179 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 526452017-01-31T19:25:00031 January 2017 19:25:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-Day Report Due to Invalid Eccs Actuation Signal ENS 514802015-08-23T16:42:00023 August 2015 16:42:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification of Invalid Primary Containment Isolation Signal ENS 491792013-05-10T05:41:00010 May 2013 05:41:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Telephonic Notification of Invalid Actuation of an Emergency Diesel Generator ENS 485812012-10-13T07:18:00013 October 2012 07:18:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Report- Invalid Specified System Actuation ENS 485522012-10-02T14:37:0002 October 2012 14:37:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation Signal of the Primary Containment Isolation Level Transmitter ENS 446742008-10-14T16:06:00014 October 2008 16:06:00 10 CFR 50.73(a)(1), Submit an LER Faulty Voltage Regulator Causes Half Scram ENS 446732008-09-25T07:41:00025 September 2008 07:41:00 10 CFR 50.73(a)(1), Submit an LER Loose Connection Causes Half Scram While Shutdown ENS 442962008-05-31T16:06:00031 May 2008 16:06:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Report Involving an Invalid Group II Primary Containment Isolation ENS 433322007-04-12T10:20:00012 April 2007 10:20:00 10 CFR 50.73(a)(1), Submit an LER Primary Containment Isolation Due to Loss of Rps Power Supply ENS 429672006-09-08T23:28:0008 September 2006 23:28:00 10 CFR 50.73(a)(1), Submit an LER Half Scram Signal Due to Equipment Failure ENS 418782005-06-03T21:05:0003 June 2005 21:05:00 10 CFR 50.73(a)(1), Submit an LER Half Scram on Voltage Regulator Failure ENS 415552005-02-14T12:18:00014 February 2005 12:18:00 10 CFR 50.73(a)(1), Submit an LER Inadvertant Safety System Actuation During Maintenance ENS 412142004-10-08T01:55:0008 October 2004 01:55:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Report Due to an Invalid Actuation of Eccs and Edgs During Surveillance Activities ENS 411842004-10-07T07:44:0007 October 2004 07:44:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation 2017-01-31T19:25:00 | |