ML042960319
| ML042960319 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 06/17/2004 |
| From: | David Loveless NRC Region 4 |
| To: | |
| References | |
| FOIA/PA-2004-0307 | |
| Download: ML042960319 (2) | |
Text
javia Loveiess - LUUr inTO Neeas.wpa rage 1 Information Needed for Risk Analysis of Loss of Offsite Power Events June 17, 2004
- 1.
Obtain copies of EOPs, AOPs, and SOP relating to the following events that were in effect at the time of the event
- a.
Reactor trip and post trip
- b.
- c.
Station blackout
- d.
Recovery of power to the switchyard
- e.
Recovery of power to the safety buses
- f.
Battery life extension (load shedding)
- g.
Operation of alternate power sources, including blackstart sources
- 2.
Obtain electrical distribution drawings showing:
- a.
- b.
Safety buses and loads
- c.
BOP buses and loads
- 3.
List of operator actions (inside and outside the control room) and time estimates needed to recover:
- a.
Offsite power to the safety buses
- b.
Start alternate power sources
- c.
Failed equipment
- d.
Unavailable equipment in test and maintenance
- 4.
Plant configuration prior to the initiating event:
- a.
List of equipment out-of-service for test and maintenance
- b.
Electrical power lineups
- c.
Battery lifetimes with proceduralized life extension (load shedding)
- d.
Reactor coolant pump seal type
- e.
Backup/alternate power sources, including blackstart capability
- 5.
Post trip conditions:
- a.
Failed equipment
- b.
Operator performance issues
- c.
Equipment performance issues (degradations)
- d.
Status of MFW and PCS (e.g., did the loss of power effect BOP buses?)
- e.
Lifting of PORV/SRV(s)
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- 6.
Offsite power recovery
- a.
Actual time when offsite power was stable (voltage and frequency) to carry loads to mitigate RCP seal and stuck open SRV LOCAs and to bring the plant to cold shutdown.
- b.
How and when would the control room know at the earliest time that offsite power was stable to carry these loads.
- c.
Actual time when offsite power was restored to the first safety bus.
- d.
Estimate of the earliest time when offsite power could have been restored to the first safety bus given a postulated station blackout or core damage sequence, such as the loss of one bus and the failure of a key component powered from the remaining bus. NOTE: This time will be confirmed by electrical and human reliability experts based on information provided above.