05000266/FIN-2010003-05
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Unit 2 Battery Inverter Transfers to Nonsafety-Related Power During Unit 1 Testing |
| Description | The inspectors identified an URI related to a potentially adverse trend associated with testing on one Units equipment inadvertently causing the inoperability of equipment on the opposite Unit. Through a review of related historical CAP documents, the inspectors identified a potential adverse trend associated with repeat occurrences of this issue. The inspectors are awaiting the licensees response to questions regarding this unintended cross-unit phenomenon as it pertains to the design basis of the facility.
The inspectors identified a potentially adverse trend associated with Unit 1 testing of electrical equipment that affected Unit 2s battery inverters and instrument bus. Specifically, during the spring 2010 Unit RFO, while operators performed Unit 1 ORT 3A step 5.8.3.c, load shedding of 4160-Volt safety bus 1A-05 and 480-Volt safety bus 1B03, Unit 2s white instrument inverter 2DY-03 transferred from its safety-related power source to its nonsafety-related alternate power source, rendering the inverter inoperable. The inspectors noted that facility design information indicated that the site was analyzed for an initiating event on one unit and that the non-affected unit would trip and be brought to a safe shutdown condition. The inspectors noted that the ORT 3A testing, which frequently produced the noted interaction between the units during recent iterations, could also occur during various accident/transient response scenarios. Because of this cross-unit interaction, the inspectors were unsure how a transient on one unit causing an unplanned inverter loss on the opposite unit was within the design and licensing basis of the facility. The licensee was evaluating the design basis related to the observed transients at the completion of the inspection period. The transient interaction between Units 1 and 2 related to DC busses and instrument inverters was considered unresolved pending the licensees evaluation of the related design basis aspect (URI 05000266/2010003-05; 05000301/2010003-05, Unit 2 Battery Inverter Transfers to Nonsafety-Related Power During Unit 1 Testing). |
| Site: | Point Beach  |
|---|---|
| Report | IR 05000266/2010003 Section 4OA2 |
| Date counted | Jun 30, 2010 (2010Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71152 |
| Inspectors (proximate) | M Kunowski M Phalen M Thorpe-Kavanaugh P Cardona-Morales R Ruiz R Winter S Burton T Bilik A Dahbur J Bozga J Jandovitz K Carringtonk Barclaym Kunowski M Thorpe Kavanaugh N Feliz Adomo P Cardona Morales R Ruiz S Burton |
| INPO aspect | |
| ' | |
Finding - Point Beach - IR 05000266/2010003 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Point Beach) @ 2010Q2
Self-Identified List (Point Beach)
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||