ML042960506
| ML042960506 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 10/18/2004 |
| From: | NRC Region 4 |
| To: | |
| References | |
| FOIA/PA-2004-0307 | |
| Download: ML042960506 (15) | |
Text
Nuclear Regulatory Commission Augmented Inspection Team Exit Meeting with Palo Verde Nuclear Generation Station
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Inspection Charter
- Basis of Augmented Inspection
- Develop a complete sequence of events
- Assess performance of plant systems
- . Assess adequacy of plant procedures
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I MF*.Wfm Inspection Charter
- Assess facility response to event
- Assess facilities determination of apparent cause
+.* Assess maintenance related contributions
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Inspection Charter
- . Assess facility coordination of offsite activities
- Overall risk assessment of event
I-s SEQUENCE OF EVENTS
- Fault Initiation
- . Electrical Transmission and Grid
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- s SEQUENCE OF EVENTS
- . Plant Transients and Challenges
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Other Challenges
A-N PERFORMANCE OF PLANT SYSTEMS
- .* Transmission system protection
- .* All three reactors were safely shut down
- Each unit was stabilized by operators
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PERFORMANCE OF PLANT SYSTEMS
- + Unit 2 Emergency Diesel Generator failure
- .+.Other minor equipment problems noted during shutdown
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Plant Procedures
- . Procedures used during event were generally acceptable
- Some issues noted
MMW Facility Response
- Conduct of operations generally good
- . Emergency response organization challenges
- Some other problems noted by the team
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j7:;ji Apparent Causes
-. Electrical fault isolation failure
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Transmission lines between Hassayampa and Palo Verde switchyard
- . Unit 2 Emergency Diesel Generator failure
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Technical Support Center Emergency Diesel Generator failure
- Others
Maintenance Related Aspects
- Maintenance of switchyard and substation equipment good
- . Implementation of facility maintenance processes
SUEDAMINOs A.C Off-Site Coordination
- . Good coordination of actions following event
- t Unrecognized design issue with Hassayampa to Palo Verde transmission line protection
Overall Risk Assessment
- Given the loss of approximately 5,500 MWe of electrical generation, the grid performed well
- Electrical power was restored in a timely*
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Overall Risk Assessment
- All three units were stabilized and placed in a safe shutdown mode of operation