ML053220524

E-mail from Don Marksberry to David Loveless & Troy Pruett Re Palo Verdes Assumptions - the New Tabled Added

ML053220524
Person / Time
Site:	Palo Verde
Issue date:	06/24/2004
From:	Marksberry D NRC/RES/DRAA
To:	David Loveless, Troy Pruett NRC Region 4
References
FOIA/PA-2004-0307
Download: ML053220524 (1)

Text

Paae 1ii David - assumptions - The Verde assumpUons Palo Verde David Loveless - Palo -

The new tabled added new tabled added Pacie 1 1- NL3 From: Don Marksberry To: David Loveless; Troy Pruett Date: Thu, Jun 24, 2004 7:36 AM

Subject:

Palo Verde assumptions - The new tabled added David, Here is the revised table. I fixed some typos and hi-lited new items I am checking out a potential modeling enhancement for sequence LOOP 18 concerning the 50-50 probability term (GTG-TO-BUSA and -BUSB). We may want to credit recovery (swapping GTG to the other bus for some cutsets that don't have a human error event already in the cutset---meaning no complete dependency). More to come.

Also, the sensitivity analysis is used to show modeling uncertainties. In ASP, if each sensitivity (one sensitivity analysis at a time) is within the parameter uncertainty bounds of the best estimate, then we go with the best estimate. If they don't, then we investigate the failure probability further.

Unit 2 CCDP Mean = 2E-4 95% = 6E-4 5%= 4E-5 CC: Gary Demoss; internet: buelrf inel.gov; Joseph Minarick; Michael Cheok; Richard Rasmussen; Russell Gibbs