ML20203E198
| ML20203E198 | |
| Person / Time | |
|---|---|
| Issue date: | 02/08/1999 |
| From: | Wessman R NRC (Affiliation Not Assigned) |
| To: | NRC (Affiliation Not Assigned) |
| References | |
| NUDOCS 9902170119 | |
| Download: ML20203E198 (2) | |
Text
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February 8,1999 MEMORANDUM TO: File FROM:
. H. Wessman, Deputy Director i
Division of Engineering
SUBJECT:
DISCUSSION WITH REPRESENTATIVES OF NEl i
On January 28,1999, several members of the staff held a conversation with representatives of Nuclear Energy Institute (NEI) regarding spent fuel cask issues. This conversation was held between NEl and members of a panel considering a differing professional opinion (DPO) regarding spent fuel cask closure welds.
NEl has been actively involved in spent fuel cask technical issues and recent public workshops held July 1-2 and August 26,1998. NEl has sponsored an " issues task force" which is comprised of vendors, manufacturers and utilities to bring industry focus to cask matters and industry coordir:ation with NRC. On October 20,1998, NEl submitted an Industry Spent Fuel Dry Cask Weld Crack Position Paper, dated October 9,1998, to NRC. The DPO Panel j
discussion with NEl was to develop a better understar. ding of NEl activities in this area and clarify certain aspects of the Industry Position Paper.
NEl reaffirmed material presented to NRC as part of the 1998 workshops and the conclusions presented in the October 9,1998 Position Paper. In the Position Paper, NEl states, on behalf of industry, that the cask closure welds in stainless steel casks can tolerate large fabrication i
defects and that the likelihood of producing such large flaws is negligible. Unstable crack growth is resisted in stainless steel closure welds even when assuming unrealistic postulated defects and that substantial margins against unstable flaw growth are available even for more realistic weld defects. NEl states the postulated flaws in stainless steel closure welds could be readily detected by conventional UT examination procedures and by either root / final or multiple-pass PT examination methods. - NEl also provides a recommended weld efficiency factor and flaw size acceptance criteria.
NEl representatives stated that NEl continues to interact with EPRI and ASME and supports the development of long-term criteria. in the interim, and in recognition of near-term licensing activity, NEl stated their agreement with the provisions of ISG-4 (Cask Closure Weld Inspections), dated October 2,1998, regarding allowing either UT or PT closure weld NDE methods, with the appropriate controls. NEl stated they are continuing to interact with NRC sta and are participants in a meeting scheduled for March 2-3,1999 on cask issues between industry and the Spent Fuel Project Office (SFPO). The NEl representatives did not believe j'
there was a near-term safety issue with allowing PT examination of stainless steel cask closure
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l NEl and the DPO Panel briefly considered the concept of a performance-based approach for i
stainless steel cask closure welds and whether any risk informed analysis of cask failures had been accomplished. NEl did not have substantive recommendations regarding performance j
- based concepts for examining cask closure welds and recognized it would be difficult to establish
- j a process to qualify techniques and individuals for a performance demonstration process.. NEl i
was not aware of any risk-informed analyses, other than a preliminary study being undertaken by i
the staff.
The discussion was for informational purposes only and no decisions were made as part of this discussion.
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CC:
L. Hendricks, NEl W. Hodges, SFPO.
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.l Distnbution':
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E. Hackett 1 i
M. Modes R.' Parkhill PDR'[
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