ML083231033

E-mail from L. Lund, NRR to D. Ashley, NRR on Sexton and Smith Letter

ML083231033
Person / Time
Site:	Oyster Creek
Issue date:	05/02/2008
From:	Lund A Office of Nuclear Reactor Regulation
To:	Ashley D Office of Nuclear Reactor Regulation
References
FOIA/PA-2008-0306
Download: ML083231033 (2)

Text

Louise Lund From: Louise Lund Sent: Friday, May 02, 2008 2:46 PM To: Donnie Ashley

Subject:

saxton and smith letter Attachments: Saxton and Smithl.doc is attached ... could you please prepare a package with EDO signing it out. We need Region I, OCA, and OGC on concurrence.

thanks!!

BL3 1.

I am writing in response to your letter, dated April 17, 2008, stating your concern about the methodologies used in calculating risk assessments for metal fatigue of recirculation nozzles, and the timeliness of dissemination of information.

Your letter indicates that the NRC stated that Oyster Creek "did not employ conservative enough methodologies in calculating risk assessments for metal fatigue of recirculation nozzles at Oyster Creek." However, this is not an accurate description of the NRC's concern. The actual concern was that a simplified analysis strategy was used (use of one stress component to represent six stress components), and~that the staff wanted to ensure that this simplified strategy was sufficiently conservative. The NRC asked the applicant for a reanalysis using the six stress components, and until we review the reanalysis, we can't make the finding that the methodology is not "conservative enough".

It is also important to recognize that the analysis is not a "risk assessment" calculation but a deterministic fatigue calculation consistent with ASME Section III analysis rules.

The ASME Code contains acceptance criteria, but doesn't specify the analysis methods to be used. Standard practice for engineers using the Code is to make simplifications to the analysis when appropriately justified. The reason that we asked Oyster Creek to perform a detailed analysis was to ensure that they made the appropriate simplification in their analysis.

To document our review of the reanalysis, we plan to document (in a publicly available supplement to the safety evaluation report) a thorough evaluation of the fatigue analysis consistent with what we wrote in the Vermont Yankee safety evaluation report. We have requested the necessary details of the analysis sufficient for our staff to evaluate whether the approach is sufficiently conservative. We will include details of the analysis to the extent that this information is not proprietary. NRC staff is prohibited from disclosing information to the public that is legitimately held and submitted by the licensees as proprietary pursuant to 10 CFR 2.390(b)(3).

The schedule for a final decision on this issue has not yet been determined. The April 20, 2008 you mention in your letter was for an affirmation session (which has been postponed) on two other matters, and not for a final decision on Oyster Creek re-licensing. When a date for re-licensing decision has been set, the NRC will ensure that you are notified promptly.

As to your concern over timely dissemination of critical information, the NRC places a high priority on keeping Congress fully and currently informed, and we will be sure to notify you as soon as possible of all further developments on the Oyster Creek license renewal process. We assume that your concern in this area relates to the Regulatory Issue Summary (RIS) that inadvertently was released around April 14, 2008. We regret that this summary was prematurely released as publicly available in our document management system, and was not meant to be in the public domain at that point.

Though we recognize your concern that you were not informed of its issuance, the RIS had not been officially issued and it would have been inappropriate to provide information or comment on a document that was mistakenly put in the public domain.

The RIS was formally issued for a 45-day public comment period on April 23, 2008, and is available through the NRC's Agencywide Documents Access and Management System (ADAMS) under accession number ML081080562.