ML030860344
| ML030860344 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/25/2002 |
| From: | Long S Office of Nuclear Reactor Regulation |
| To: | Pickett D Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2003-0018 | |
| Download: ML030860344 (3) | |
Text
Page 1 teven Long - Re. Fwd: FENOC Response to RAI Question 1.d From:
Steven Long
~
i To:
Douglas Pickett "
Date:
7/25/02 5.19PM
Subject:
Re: Fwd: FENOC Response to RAI Question 1 d Doug, As for me, any time next week except Friday and between 10"30 and 11:39 on Tuesday. Do we want to get anybody from RES involved? Steve
>>> Douglas Pickett 07/25/02 05"15PM >>>
Steve FENOC is ready to talk. I'll be out of the office tomorrow but give me your preferences for next week Doug
, [ Steven Long - Re: Fwd: FENOC Response to RAI Question 1.d From:
<mriemer@firstenergycorp.com>
To:
"Douglas Pickett" <DVP1 @nrc.gov>
Date:
7/25/02 3 17PM
Subject:
Re: Fwd. FENOC Response to RAI Question 1.d
- Doug, I spoke with our responsible individuals and they are pretty open to support a conference call Since the consultants who performed the analysis are on the west coast, calls after 11:00 am are desired If you suggest a time, we should be able to support it.
Mark V
"Douglas Pickett" To:
<mriemer@firstenergycorp.com>
<DVP1@nrc gov>
cc:
<Dale_r._wuokko@firstenergycorp.com>, <Michael.k.
leisure@firstenergycorp.com>, "Steven Long" <SML@nrc gov>
07/25/02 11:29 Subject Fwd FENOC Response to RAI Question 1.d AM Mark The attached email from the NRR tech staff has a question concerning the July 20, 2002 submittal on the Safety Significance Assessment We would like to schedule a conference call with the appropriate people to discuss the concern Please let me know what can be worked out I would prefer to handle this as a simple background information type call as opposed to a formal RAI at this time Thanks - Doug Message from "Steven Long" <SML@nrc gov> on Thu, 25 Jul2002 11:14:09
-0400 To: "Douglas Pickett"
<DVP1 @nrc.gov>
Subject. FENOC Response to RAI Question 1.d
- Doug, Ppag I
Page21 Ste ogRe: Fwd: FENOC Response to RAI Question 1.d I read the FENOC response dated 7/20/02 and found that is was not actually responsive to the most important part of our question We asked what the size the cavity would have to reach before its failure pressure would decrease to the plant's normal operating pressure. We specified consideration of two cladding thicknesses, the minimum allowed (0.125") and the average value actually found in the cavity (0.297"). They did provide an answer for the 0.125" case. However, they terminated their enlargement study at a cavity size with 4 times the as-found area, with the best estimate for the failure pressure with the as-found clad thickness still at 4172 psi They did make a linear extrapolation for that clad thickness case to failure at 102.5 square inches of exposed clad. But the appearance of figures 6 and 7 indicate that extrapolation is highly unreliable because the failure pressure is not a linear function of exposed area So it is not feasible even to say if that estimate is an over-prediction or an under-prediction..
The criterion for stopping the expansion calculations at 82 square inches is stated on page 4: "The decision to limit the cavity growth value to 4A for this evaluation is to ensure that Tube 11 is not fully exposed."
However, no reason is provided for selecting that criterion.
Please ask the licensee to provide an explanation of the engineering considerations that caused them to stop the evaluation short of fully encompassing nozzle 11. It would be helpful if the explanation includes some discussion as to whether those engineering considerations would tend to make the cavity fail at a smaller or larger size than would estimates that exclude those considerations An e-mail response will be sufficient for my purposes Steve