ML083231034
| ML083231034 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 05/05/2008 |
| From: | Lund A Office of Nuclear Reactor Regulation |
| To: | Ronald Bellamy, Conte R, Marjorie Mclaughlin, Neil Sheehan NRC Region 1 |
| References | |
| FOIA/PA-2008-0306 | |
| Download: ML083231034 (2) | |
Text
L7uiL Louise Lund From:
Sent:
To:
Cc:
Subject:
Attachments:
Louise Lund Monday, May 05, 2008 11:46 AM Neil Sheehan; Richard Conte; Marjorie McLaughlin; Ronald Bellamy Donnie Ashley; Samson Lee; Tom Blount; Brian Holian summary bullets on 0C fatigue response RAI response fatigue.doc The attached is what I promised Neil and Diane. I summarized the response frdm Amergen on their fatigue reanalysis into easy-to-digest bullets.
I
May 5, 2008 Amergen's response to Staff's question on the use of Green's function simplification for their fatigue analysis:
Received response from Amergen dated May 1, 2008, responding to RAI on fatigue calculation dated April 29, 2008.
Cumulative usage factor (CUF) was reanalyzed for reactor pressure vessel recirculation outlet nozzle, with an acceptance criteria of <1.
Cumulative usage factor was reduced in reanalysis from the original value of 0.9781 to 0.1366.
Original analysis made use of Green's function simplification. New analysis is standard ASME Code Section III NB-3200 fatigue analysis.
New analysis uses essentially the same input parameters and assumptions, except for the following: (1) used six components of stress, instead of one; (2) stainless.steel cladding was'neglected, and fatigue calculation was performed solely for the carbon steel base metal; (3) included a hold time to ensure that peak stress was captured in analysis; and (4) used recalculated environmental fatigue factors.
Largest impact to calculation is neglecting stainless steel cladding.
" Reactor recirculation nozzle was only location where Green's function had been used for calculating fatigue usage.
Staff will be reviewing the RAI response to see if it is acceptable, and will be issuing a safety evaluation supplement.