ML053220456

Table Titled Palo Verde Unit 2 - June 14, 2004 Loss of Offsite Power Event - June 24, 2004 (8:04am)

ML053220456
Person / Time
Site:	Palo Verde
Issue date:	11/15/2005
From:	- No Known Affiliation
To:	Office of Nuclear Reactor Regulation
References
FOIA/PA-2004-0307
Download: ML053220456 (2)

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7.

1 EDG "A" failed to srte ot recoverable due to circuitry failure in

• EPS-DGN-FS-DGA = True N. Must set FTR event to true the exciter circuit

• EPS-DGN-FS-DGA = True to calculate CCF 2 Charging pump 'E" failed to-stat C v_

Not recoverable due to air binding -

operator have to bleed pump CVC-MDP-FS-CHE = True CVC-MDP-FR-CHE = True 5:j -t-,

3 Power restored to Unit 2 in Mission times for EDG and TDAFW pump

• EPS-DGN-FR-FTRM N. EDG FTR-medium basic 2 hrs 15 mins 2.5 hrs mission time = 2.0 event applies to the time

. AFW-TDP-FR-A mission range of 0.5 to 14 hrs time = 2.5 hrs 4 Offsite power available Recovery of power to first vital bus possible See below Q. Can power to vital bus be from Dever line shortly within one hour following a postulated SBO recovered within 60 min?

after event initiation Q. What are the steps/actions needed for recovery?

S. Do sensitivity analysis for offsite power recovery within 30 minutes for all three basic

.event below Recovery, of power during a postulated OEP-XHE-NOREC-ST = 0.1 S. Do sensitivity analysis for SBO and AFW failure: offsite power recovery within

• Time available = time required (time to (10 x 5 x 2 x le-3 = 0.1) 30 minutes (P = 0.01 with

_r Time Available = nominal or

.*Stress = extreme (core unoey 5 xi)

NV Eimminent if operator fails) t

\,5&S F* Comp exi y = mo erate (communications and coordination required outside control room)

• All other performance shaping factors are nominal

,f -'T 4 J.

5 RCP seals are the KSB SPAR uses the CE RCP seal LOCA model, None S. Do sensitivity analysis type where the licensee which is under review by NRC using conservative seal LOCA claims not to fail during model loss of seal cooling/injection (about 17 gpm leak) 6 No EDG recovery credited SPAR does not credit nominal EDG None S. Does not affect dominate recovery sequences Draft Preliminary Results -June 25, 2004 (9:49AM)

Run cases 5 %tile Mean&\e: 95 %tile Unit 2:

1. Best estimate: EDG WA" FTS, CVC OEF FTS, power recoverable w/i 1 hr 4E-5 2E 6Er-

2. Sensitivity Al: Offsite power recovery to first vital bus w-i 30 mi + extreme stress 1E-4

3. Sensitivity A2: Offsite power recovery to first vital bus w/i 30 min + high stress I E-4

4. Sensitivity BI: No RCP seal LOCA possible (P=0.0) + r-4 2in

5. Sensitivity B2: Assume Rhodes RCP seal LOCA possible (P=0.2) 7E-4

6. Sensitivity C: Credit nominal AFW pump recovery (from NUREG/CR-5500, Vol 1) 2E-2

7. Sensitivity D: Offsite power recovery to first vital bus w/i 1 hr + high stress 2E-4 Unit 1:

8. Best estimate: Offsite power recoverable w/i 1 hr + no complications 5E-6 3E-5 8E-5 Unit 3:

9. Best estimate: Offsite power recoverable w/i 1 hr + no complications 5E-6 3E-5 8E-5