ENS 48552
ENS Event | |
|---|---|
14:37 Oct 2, 2012 | |
| Title | Invalid Actuation Signal of the Primary Containment Isolation Level Transmitter |
| Event Description | This 60-day telephone notification is being made in accordance with the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) to describe an invalid actuation signal of the primary containment isolation level transmitter (02-3LT-101A).
Status of SSC's that were inoperable and contributed to the event: The B Reactor Protection System (RPS) was inoperable due to performance of Emergency Diesel Generator (EDG) B & D Load Sequencing test and 4KV Emergency Power System voltage relay instrument functional test. Therefore, the B RPS was deenergized and associated B RPS channels were tripped. Narrative: On 10/2/2012 at 09:37 hours, James A. Fitzpatrick Nuclear Station received a full reactor scram actuation from reactor vessel level transmitter 02-3LT-101A, containment Isolation. The full scram was due to an equipment malfunction, no low level condition was actually present at the time. It was determined that the replacement of refueling water level transmitter 02-3LT-61 on 09/30/12 was incorrectly performed by not properly venting the sensing line after installation. The common sensing line contains a local high point inside the drywell. The mechanism is air displaces the water in the line causing pressure to momentarily drop which causes the instrument to trip as if reactor water level had actually dropped. Air propagation in one sensing line can have an impact on all of the instruments attached to the common sensing line. Corrective Actions: A back flush was performed for instrument rack 25-5. Applicable I&C Post maintenance testing procedures will be updated to include a back flush or forward flush to ensure that instrument lines are properly vented prior to returning the instrument lines to service. The following additional information is provided: On 10/2/2012 at 09:45 hours, shift performed OP-18 to reset the scram that occurred at 0937 EST. The procedure provided guidance to install jumpers to allow the scram discharge instrument volume (SDIV) high level scram signal to be bypassed. The jumpers were required since one channel of the RPS was inoperable due to performance of EDG B & D Load Sequencing test and 4KV Emergency Power System voltage relay instrument functional test. On 10/2/2012 at 10:07 hours, James A. Fitzpatrick Nuclear Station received another full reactor SCRAM actuation of the SDIV B hi-level trip. The safety function of the actuation had already been completed as a result of the previous scram due to the RPS B bus being de-energized, the SDIV B could not be drained. The SDIV A was also not yet drained, and the high level signal was still technically a valid signal that was present. AOP-1 contained steps to verify that the SDIV A or B 'not drained' annunciators are clear before placing the SDIV by-pass switch to normal position. This step was not performed. It was therefore determined to be an invalid signal based on NUREG-1022 guidance: 'actuations initiated for reasons other than to mitigate an event need not be reported.' The signal was actuated during an attempt to reset the previous SCRAM per OP-18, the occurrence of the signal was due to inadequate work planning, and a procedural deficiency which caused the jumpers to be removed prior to draining the SDIV A. Therefore this event did not meet the criteria for being a valid actuation. Additional Corrective Actions: Revise OP-18 to provide adequate guidance how to reset a SCRAM with one RPS bus de-energized. The licensee informed 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:+1483.68 h61.82 days <br />8.831 weeks <br />2.032 months <br />) | |
| Opened: | Jorge O'Farrill 11:18 Dec 3, 2012 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Dec 3, 2012 |
| 48552 - NRC Website
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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 | |