|
|
| Line 1: |
Line 1: |
| {{Adams
| | #REDIRECT [[05000387/LER-2017-004, Regarding Secondary Containment Breach Due to Simultaneous Opening of Airlock Doors]] |
| | number = ML17216A286
| |
| | issue date = 08/04/2017
| |
| | title = Regarding Secondary Containment Declared Inoperable Due to Failure of an Exhaust Fan Breaker
| |
| | author name = Berryman B
| |
| | author affiliation = Susquehanna Nuclear, LLC, Talen Energy
| |
| | addressee name =
| |
| | addressee affiliation = NRC/Document Control Desk, NRC/NRR
| |
| | docket = 05000387, 05000388
| |
| | license number = NPF-014, NPF-022
| |
| | contact person =
| |
| | case reference number = PLA-7628
| |
| | document report number = LER 17-004-00
| |
| | document type = Letter, Licensee Event Report (LER)
| |
| | page count = 4
| |
| }}
| |
| {{LER
| |
| | Title = Regarding Secondary Containment Declared Inoperable Due to Failure of an Exhaust Fan Breaker
| |
| | Plant =
| |
| | Reporting criterion = 10 CFR 50.73(a)(2)(v)
| |
| | Power level =
| |
| | Mode =
| |
| | Docket = 05000387
| |
| | LER year = 1917
| |
| | LER number = 4
| |
| | LER revision = 0
| |
| | Event date =
| |
| | Report date =
| |
| | ENS =
| |
| | abstract =
| |
| }}
| |
| | |
| =text=
| |
| {{#Wiki_filter:AUGO 4 2017 Brad Berryman Site Vice President U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Susquehanna Nuclear, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.2904 Fax 570.542.1504 Brad.Berryman@TalenEnergy.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387(388)/2017-004-00 UNIT 1 LICENSE NO. NPF-14 UNIT 2 LICENSE NO. NPF-22 PLA-7628 TALEN~
| |
| ENERGY 10 CFR 50.73 Docket No. 50-387 50-388 Attached is Licensee Event Report (LER) 50-387(388)/2017-004-00. The LER reports an event involving a failure of an exhaust fan breaker which resulted in a loss of Secondary Containment Zone 3 differential pressure. This event was determined to be reportable in accordance with 10 CFR 50.73(a)(2)(v)(C) as a condition that could have prevented fulfilment of a safety function.
| |
| There were no actual consequences to the health and safety of the public as a result of this event.
| |
| This letter contains no new regulatory commitments.
| |
| /
| |
| B. BelTyman Attachment: LER 50-387(388)/2017-004-00 Copy:
| |
| NRC Region I Ms. T. E. Hood, NRC Project Manager Ms. L. H. Micewski, NRC Sr. Resident Inspector Mr. M. Shields, PA DEP/BRP
| |
| | |
| NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2017)
| |
| , the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
| |
| : 2. DOCKET NUMBER YEAR 05000387 2017
| |
| : 3. LER NUMBER SEQUENTIAL NUMBER
| |
| :- 004 REV NO.
| |
| :- 00 Unit 1 - Mode 3, approximately 0 percent Rated Thermal Power Unit 2 - Mode 1, approximately 100 percent Rated Thermal Power Unit 1 was in the process of starting up following a Scram on 6/8/17, however, this did not contribute to the event. There were no structures, systems, or components that were inoperable on Unit 2 that contributed to this event.
| |
| | |
| ==EVENT DESCRIPTION==
| |
| On June 8, 2017 at approximately 2206, at the start of restoration of the Reactor Building HVAC [EllS Code:
| |
| NG] Unit 1 Zone 3 ventilation post Unit 1 SCRAM, Operations placed the 'A' Reactor Building Zone 3 Filtered Exhaust Fan [EllS Code: FAN] in service. The 'A' Reactor Building Zone 3 Supply Fan [EllS Code:
| |
| FAN] started but the 'A' Reactor Building Zone 3 Exhaust Fan [EllS Code: FAN] did not. With the Filtered Exhaust Fan in service, the supply air was greater than the exhaust air which resulted in a loss of differential pressure.
| |
| 6/9/17 0441: Operations entered Technical Specification (TS) 3.6.4.1 due to Secondary Containment being inoperable during the start of the Zone 3 fan.
| |
| 6/9/17 0449: Operations cleared TS 3.6.4.1.
| |
| 6/9/17 0509: Secondary Containment Zone 3 differential pressure lowered to 0" WG as a result of the Reactor Building HVAC fans tripping and restarting several times. The required differential pressure per Surveillance Requirement 3.6.4.1.1 could not be maintained. Operations placed Unit 1 Zone 3 Filtered Exhaust in the STOP position.
| |
| 6/9/17 0941: Operations entered LCO 3.6.4.1 due to Secondary Containment being inoperable while restoring Unit 1 Zone 3 HVAC.
| |
| 6/9/17 1010: While restoring Unit 1 Zone 3 HVAC, a bell alarm for the Reactor Building Zone 3 Exhaust Fan supply breaker could not be reset.
| |
| 6/9/17 1015: Operations placed the Unit 1 Zone 3 system in service using the 'B' Unit 1 Zone 3 fans. The 'A' Reactor Building Supply Fan and 'A' Reactor Building Filtered Exhaust Fans were placed in STANDBY.
| |
| The 'A' Reactor Building Exhaust Fan was left in STOP.
| |
| 6/9/17 11 :11 The Maintenance investigation revealed that the terminal connection was broken in the supply breaker [EllS Code: BKR] for the 'A' Reactor Building Zone 3 Exhaust Fan.
| |
| Maintenance replaced the ring terminal and re-terminated the wire. The exhaust fan was successfully placed in service. Zone 3 differential pressure was recovered to> 0.25"WG following the restart of Unit 2 Zone 3 Secondary Containment fans. Zones 1 and 2 were not affected. This event is being reported under 10 CFR 50. 73(a)(2)(v)(C) as a condition that oculd have prevented the fulfillment of a safety function.
| |
| NRC FORM 3668 (04-2017)
| |
| Page 2 of 3 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 3/31/2020 (04-2017)
| |
| LICENSEE EVENT REPORT (LER)
| |
| CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://WMN. nrc.qov/readi nq-rm/doc-collections/nuregs/staff/sr1 022/r3/)
| |
| : 1. FACILITY NAME Susquehanna Steam Electric Station Unit 1
| |
| | |
| ==CAUSE OF EVENT==
| |
| , the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
| |
| : 2. DOCKET NUMBER YEAR 05000387 2017
| |
| : 3. LER NUMBER SEQUENTIAL NUMBER
| |
| :- 004 REV NO.
| |
| :- 00 The cause was determined to be a broken ring terminal on the breaker [EllS Code: BKR] which prevented the fan from starting.
| |
| | |
| ==ANALYSIS/SAFETY SIGNIFICANCE==
| |
| An engineering evaluation was performed and concluded that secondary containment could have performed its safety function of isolating as assumed in the accident analysis and also of re-establishing 0.25 inches vacuum (drawdown) within the assumed accident analysis time (1 0 minutes). Therefore, the subject event did not cause a loss of safety function. This event will not be counted as a safety system functional failure (SSFF) for the NRC performance indicator based on the engineering analysis that shows there was no loss of ability to fulfill the safety function.
| |
| | |
| ==CORRECTIVE ACTIONS==
| |
| Maintenance replaced the ring terminal and re-terminated the wire and the exhaust fan was placed back in service.
| |
| | |
| ==PREVIOUS SIMILAR EVENTS==
| |
| The following are recent LERs involving loss of secondary containment due to component failures:
| |
| LER 50-387(388)/2016-003-00, "Unit 2 Zone 3 HVAC Unable to Maintain Differential Pressure," dated May 6, 2016.
| |
| LER 50-387(388)/2016-012-00, "Unit 2 HVAC Unable to Maintain Differential Pressure," dated May 26, 2016.
| |
| LER 50-387(388)/2015-003-00, "Inoperable Secondary Containment Due to Fan Trips During Wind Gusts," dated June 22, 2015.
| |
| LER 50-387(388)/2015-005-00, "Loss of Secondary Containment Due to Unit 2 Damper Alignment," dated June 25,2015.
| |
| LER 50-387(388)/2015-01 0-00, "Loss of Zone 2 During Unit 1 Reactor SCRAM," dated January 8, 2016.
| |
| LER 50-387(388)/2015-012-00, "Loss of Secondary Containment Differential Pressure Due to Icing of the Intake Supply Plenum Screens," dated February 2, 2016.
| |
| LER 50-387(388)/2015-013-00, "Loss of Secondary Containment Due to Failure of Fans," dated February 2, 2016.
| |
| NRC FORM 3666 (04-2017)
| |
| }}
| |
| | |
| {{LER-Nav}}
| |