ML20044B492
| ML20044B492 | |
| Person / Time | |
|---|---|
| Issue date: | 02/24/1992 |
| From: | Hermann R Office of Nuclear Reactor Regulation |
| To: | Taylor J BABCOCK & WILCOX OPERATING PLANTS OWNERS GROUP |
| References | |
| NUDOCS 9203030363 | |
| Download: ML20044B492 (2) | |
Text
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'o UNITED STATES g
j NUCLEAR REGULATORY COMMISSION o
j WASHINGTON, D. C. 20555 k..../
(f,B <31 $92.
+
Mr. J. H. Taylor, Manager
)
Licensing Services i
The B&W Owners Grouop
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Suite 525
-l 1700 Rockville Pike Rockville, MD 20852
SUBJECT:
PROPOSED MEETING WITH B&W OWNERS GROUP REGARDING ALLOY 600 ACTIVITIES
Dear Mr. Taylor:
We would like to thank you for your letter dated January 27, 1992, which summarized all Alloy 600 activities sponsored by B&W Owners Group (B&WOG).
Althougn your letter has reported that B&W Owners Group is actively pursuing the investigation of the potential cracking of Alloy 600 components at your plants; however, the programs described in your summary lacks details and the discussions of the results. Therefore, to improve our understanding of your Alloy 600 activities, we propose to have a meeting with the B&W Owners Group Materials Committee, preferably in the near future, to discuss details regarding your Alloy 600 programs and plans. We believe that the proposed meeting would provide an opportunity to exchange our views on the actions that should be taken for mitigating the potential of primary water stress corrosion cracking (PWSCC) of Alloy 600 in B&W plants. We also propose that the agenda of the meeting would incluce the discussions of the following questions:
(1) Please rrovide details of the 1990 scoping study performed by the B&WOG on the target plant Crystal River Unit 3 and the results of a review of the.
3 nickel-base alloys applications performed by B&W Nuclear Service Company T
(SWNS) on Three Mile Island Unit 1.
(2) The B&WOG sponsored 1990 scoping study concluded that essentially all Alloy 600 componenets were expected to be relatively stress resistant to PWSCC. It appears that this conclusion may nut be valid considering the reported Alloy 600 nozzle cracking in ANO-1. Whet are the root causes for the reported cracking of pressurizer instrumentation nozzle in the Arkansas Nuclear One Unit 1 (ANO-1) in December 1990, and the long term fix for the cracked nozzle?
(3) It appears that, for a large part, B&WOG's decision for not pursuing a j
detailed inspection program of Alloy 600 components is based on the.
conclusion of 1990 scoping study.
However, as stated in item. (2) the i
scoping study conclusion may be questionable.
In view of the increased
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experiences of Alloy 600 cracking in both foreign and domestic plants, we would encourage B&WOG to initiate an inspection program for the early detection of Alloy 600 cracking. This pro-active inspection program is
-l consistent with the staff's defense-in-depth philosophy to ensure safe E70020 R 2.0 5 05 0 5(,5 XA
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plant: operation and is a subject for discussion at the meeting.
(4) Please provide the schedules for the on-going programs.and proposed plans relative to Alloy 600 FWSCC and be prepared to discuss, the other completed programs.
(5) What is the relevance of recent Alloy 600 cracking experience in French reactor vessels to B&W plants?
If the B&WOG Materials Committee agrees to meet with NRC staff at Rockville,.
Maryland, please let me know regarding the date for the meeting so that lP ease do not hesitate to drrangements for a Conference roDm Can be made.
call me at (301)504-2768 for additional information.
t Sincerely,
'g S%ntd DU c g.Hermann Robert A; Hermann, Chief l
Chemical Engineering & Metallurgy Section-Hattrials and Chemical. Engineering Branch Division of Engineering Technology l
Office of Nuclear reactor Regulation i
cc: B. D. Liaw, J. Richardson DISTRIBUTION-Central Files EMCB WKoo RHermann JWiggins
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