ENS 41193: Difference between revisions
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StriderTol (talk | contribs) (Created page by program invented by Mark Hawes) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
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| event date = 09/28/2004 01:00 EST | | event date = 09/28/2004 01:00 EST | ||
| last update date = 11/12/2004 | | last update date = 11/12/2004 | ||
| title = Invalid Specified System Actuation Due | | title = Invalid Specified System Actuation Due to Bus Voltage Dip During Recirc Mg Start | ||
| event text = 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 specified systems, specifically the Unit 2 Primary Containment Isolation System (PCIS). | | event text = 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 specified systems, specifically the Unit 2 Primary Containment Isolation System (PCIS). | ||
On 9/28/04, at approximately 0100 hours [EDT], a Group III Outboard PCIS isolation occurred during the start of the 2B Recirculation Motor / Generator (M/G) Set. The Recirculation M/G Set was being started to perform post-maintenance testing during the refueling outage subsequent to work involving the Recirculation M/G Set. This outboard isolation resulted in the closure of various valves associated with the Reactor Building / Refueling Floor Ventilation Systems and the start of the 'B' Standby Gas Treatment Fan. All equipment operated as designed. The isolation occurred as a result of a voltage dip on the 2B Reactor Protection System (RPS) / PCIS power supply while on its alternate feed at the time that the 2B Recirculation M/G Set was started. The 2B RPS / PCIS power supply was on the alternate feed in preparation for planned testing of the Emergency Diesel Generators (LOCA-LOOP testing). This RPS / PCIS power supply alternate feed was fed from the same startup transformer that the 2B Recirculation MG Set is fed from. The voltage dip from the start of the large Recirculation M/G Set was sufficient to cause the protective relaying on the 2B RPS /PCIS alternate feed power supply to shed the power supply from the 2B RPS / PCIS bus. Deenergization of the bus caused the Group III Outboard PCIS isolation. A � RPS scram signal was also generated. Just prior to the start of the 2B Recirculation M/G set, Operations personnel were briefed on the probability of the isolation and were prepared to take prompt action to reset the isolation and � Scram. The 2B RPS / PCIS power supply was returned to its normal power supply (i.e. 2B RPS M/G Set) and the Group III PCIS and the � Scram was promptly reset by 0105 hours. This issue has been entered into the Corrective Action Program (CR 257503). | On 9/28/04, at approximately 0100 hours [EDT], a Group III Outboard PCIS isolation occurred during the start of the 2B Recirculation Motor / Generator (M/G) Set. The Recirculation M/G Set was being started to perform post-maintenance testing during the refueling outage subsequent to work involving the Recirculation M/G Set. This outboard isolation resulted in the closure of various valves associated with the Reactor Building / Refueling Floor Ventilation Systems and the start of the 'B' Standby Gas Treatment Fan. All equipment operated as designed. The isolation occurred as a result of a voltage dip on the 2B Reactor Protection System (RPS) / PCIS power supply while on its alternate feed at the time that the 2B Recirculation M/G Set was started. The 2B RPS / PCIS power supply was on the alternate feed in preparation for planned testing of the Emergency Diesel Generators (LOCA-LOOP testing). This RPS / PCIS power supply alternate feed was fed from the same startup transformer that the 2B Recirculation MG Set is fed from. The voltage dip from the start of the large Recirculation M/G Set was sufficient to cause the protective relaying on the 2B RPS /PCIS alternate feed power supply to shed the power supply from the 2B RPS / PCIS bus. Deenergization of the bus caused the Group III Outboard PCIS isolation. A � RPS scram signal was also generated. Just prior to the start of the 2B Recirculation M/G set, Operations personnel were briefed on the probability of the isolation and were prepared to take prompt action to reset the isolation and � Scram. The 2B RPS / PCIS power supply was returned to its normal power supply (i.e. 2B RPS M/G Set) and the Group III PCIS and the � Scram was promptly reset by 0105 hours. This issue has been entered into the Corrective Action Program (CR 257503). | ||
Latest revision as of 21:22, 1 March 2018
| Where | |
|---|---|
Peach Bottom  Pennsylvania (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1083.97 h45.165 days <br />6.452 weeks <br />1.485 months <br />) | |
| Opened: | David Foss 10:58 Nov 12, 2004 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Nov 12, 2004 |
| 41193 - NRC Website
| |