ML042960319
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| 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. LOOP
- 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. Switchyard
- 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)
- 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.