ENS 40198
ENS Event | |
|---|---|
04:00 Sep 25, 2003 | |
| Title | Initiation of a Technical Specification Required Shutdown at Peach Bottom 2 |
| Event Description | On 09/25/03 @ 2210, while restoring reactor vessel instrumentation to service on Unit 3, an invalid ECCS actuation, (reactor vessel lo-lo-lo) occurred which caused all four (4) EDG to automatically start. All eight (8) 4 KV buses remained supplied from offsite sources. The Unit 3 ECCS pump auto starts were previously defeated per plant procedure and were not required to be operable per Tech Specs. The invalid ECCS initiation signal caused the offsite power Loss-of-Power instrumentation setpoints to transfer to the degraded voltage LOCA setpoints. With the degraded voltage LOCA setpoints initiated, the 4 KV E-bus fast transfer capability on a degraded voltage-NON-LOCA condition is defeated. With the inability to fast transfer the 4 KV E-buses on a degraded voltage NON-LOCA condition, both offsite sources are inoperable. Prior to restoring the reactor vessel level instrumentation, the E-2 diesel generator was inoperable. With both offsite source.; and one EDG inoperable, LCO 3.8.1 Required Action H.1 requires an entry into LCO 3.0.3 for Unit 2.
With Unit 3 in MODE 5, LCO 3.0.3 is not applicable. After one (1) hour, actions were taken to initiate a plant shutdown per LCO 3.0.3. No negative reactivity was added as the preparations were administrative in nature. At 09/26/03 @ 0006, the invalid ECCS initiation was removed. And all offsite Loss-of-Power instrumentation has been returned to OPERABLE status. Following the automatic start of all four (4) EDGs, E-1, E-3, and E-4 were successfully shutdown per plant procedures. E-2 could not be shutdown per plant procedures and was shutdown locally. The cause of the inability to shutdown E-2 per plant procedures is under investigation. E-2 EDG remains inoperable. The NRC Resident Inspector was notified by the licensee.
This 60-day optional report, as allowed by 10 CFR 50.73(a)(1), is being made under the reporting requirement in 10CFR50.73(a)(2)(iv)(A) to describe an unplanned, invalid actuation of a specified system, specifically the Units 2 and 3 Emergency Diesel Generators (EDGs).' 'On 9/25/03 at 2210 while restoring reactor vessel instrumentation to service on Unit 3, an invalid EDG start actuation signal on Reactor Vessel Lo-Lo-Lo level occurred which caused all four Emergency Diesel Generators to automatically start. Investigation into the cause of the event identified that the sequence of operating instrument valves associated with the instrument rack for level transmitters LT 72A and LT 72C resulted in the invalid reactor vessel lo-lo-lo reactor water level signal and subsequent EDG logic actuation. The EDGs initiated as expected for the given conditions. Off-site power was not affected and continued to supply power to the emergency busses. Once the reason for the EDG initiation was determined, the E-1, E-3, and E-4 EDGs were shut down per plant procedures from the Main Control Room by approximately 2255 hours0.0261 days <br />0.626 hours <br />0.00373 weeks <br />8.580275e-4 months <br />. The E-2 EDG could not be shut down normally from the Main Control Room control switch. It was later shut down at the local control panel in the E-2 EDG bay at about 0030 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> on 9/26/03. Repairs to the E-2 EDG control switch were completed in accordance with the Corrective Action Program (CR 177605).' 'Notification of the event to the NRC was initially made at 0125 on 9/26/03 (EN 40198). Since the initial report, it was determined that a Technical Specification LCO 3.0.3 condition did not exist since the off-site sources were operable. This event has been entered into the site-specific corrective action program for resolution (CR 1776 10). The licensee has informed the NRC Resident Inspector. |
| Where | |
|---|---|
Peach Bottom  Pennsylvania (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown 10 CFR 50.72(b)(3)(iv)(A), System Actuation 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+21.42 h0.893 days <br />0.127 weeks <br />0.0293 months <br />) | |
| Opened: | Todd Strayer 01:25 Sep 26, 2003 |
| NRC Officer: | Rich Laura |
| Last Updated: | Nov 10, 2003 |
| 40198 - NRC Website
Loading map... | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Peach Bottom with 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.73(a)(1), Submit an LER | |
WEEKMONTHYEARENS 572212024-07-10T11:28:00010 July 2024 11:28:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Manual Turbine Trip ENS 569362024-01-29T17:02:00029 January 2024 17:02:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram ENS 562802022-11-12T04:33:00012 November 2022 04:33:00 10 CFR 50.73(a)(1), Submit an LER 60-DAY Telephonic Notification ENS 558992022-05-16T19:52:00016 May 2022 19:52:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram Due to Electrical Transients ENS 548202020-06-08T08:24:0008 June 2020 08:24:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 536302018-09-30T04:00:00030 September 2018 04:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Automatic Scram Due to a Loss of Two Condensate Pumps ENS 536172018-09-21T04:00:00021 September 2018 04:00:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded High Pressure Coolant Injection System Inoperable ENS 529612017-07-14T18:53:00014 July 2017 18:53:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 519622016-03-28T17:20:00028 March 2016 17:20:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 500892014-03-09T21:13:0009 March 2014 21:13:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephonic Notification for an Invalid Actuation of an Emergency Service Water System ENS 479072012-03-13T20:04:00013 March 2012 20:04:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Report - Invalid Primary Containment Isolation System Actuation ENS 472862011-09-21T14:20:00021 September 2011 14:20:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Relay Malfunction Resulted in a Valid Undervoltage Signal ENS 449402009-03-02T15:55:0002 March 2009 15:55:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation Signal Due to Maintenance Error ENS 444652008-07-24T03:25:00024 July 2008 03:25:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation Due to Loss of One Offsite Power Circuit to Safety Buses ENS 439102007-12-11T21:45:00011 December 2007 21:45:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Notification of an Invalid Actuation of Units 2 and 3 Primary Containment Isolation Systems ENS 428892006-10-07T21:50:0007 October 2006 21:50:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Technical Specification Required Shutdown Due to Loss of Primary Containment Integrity ENS 418322005-07-10T07:18:00010 July 2005 07:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Turbine Trip Resulting in Rps Actuation and Automatic Reactor Scram ENS 412772004-12-22T09:55:00022 December 2004 09:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Reactor Scram and Eccs Injection Following Opening of Turbine Bypass Valves ENS 411932004-09-28T06:00:00028 September 2004 06:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation Due to Bus Voltage Dip During Recirc Mg Start ENS 411922004-09-18T08:57:00018 September 2004 08:57:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation Due to Off Site Power Source Fast Transfer ENS 408192004-04-25T05:05:00025 April 2004 05:05:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation ENS 405372004-02-22T20:10:00022 February 2004 20:10:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Scram at Peach Bottom 2 Due to Decreasing Condenser Vacuum ENS 401982003-09-25T04:00:00025 September 2003 04:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.73(a)(1), Submit an LER Initiation of a Technical Specification Required Shutdown at Peach Bottom 2 ENS 401042003-07-27T22:39:00027 July 2003 22:39:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Report 2024-07-10T11:28:00 | |