ML20213E104
| ML20213E104 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 03/30/1982 |
| From: | Rubenstein L Office of Nuclear Reactor Regulation |
| To: | Berlinger C Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0503, CON-WNP-503 NUDOCS 8204070125 | |
| Download: ML20213E104 (2) | |
Text
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g LRubens e MEf10RAtlDU:1 FOR:
C. Berlinger, Chief, Core Perfomance Branch, D P OSn L. S. Rubenstein, A/D for Core & Plant Systems, {I #lg?![ ~4 ty FROM:
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SUBJECT:
WPPS-2 REVIEW ITEM ON WATERSIDE CORROSION 4,
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The WPPS-2 SER originally contained a licensing condition requiring t thW applicant provide a commitment for a procedure to control water chemistry o prevent waterside corrosion. This was clearly a new requirement, beyond those described in SRP Section 5.4.8, and one which is the responsibility of CMEB to develop and which would require NRR management and CRGR approval to implement. The SER as submitted to me lists waterside corrosion as an open item pending submittal by the applicant of its plans for preventive This memorandum provides the guidance for dealing with this issue measures.
and in it I conclude that the item should be considered closed for UPPS-2 and subsequent BWR plant reviews. The following is the basis for this guidance.
Waterside corrosion can occur in B'#Rs with copper-containing feedwater tubing.
If erosion of the tubing results in a buildup of copper above a certain amount in the primary system coolant, it can result in crud. The copper-bearing crud when preferentially deposited on gadolinia containing poison rods which are clad with zircaloy with a within-specification material variability has in the past led to localized corrosion failures of about 120 gadolinia poison rods out of about 45,000 gadolinia rods, in about 9,000 fuel bundles (5 gadolinia rods per bundle).
Thus, I believe this issue to be of little safety significance and not requiring regulation at this tine.
In general, I am comfortable with this decision because the staff has appropriately identified this as a matter of concern and has had a number of conversations meetings with the fuel manufacturer, the BWR owners. group, and discussed this with individual licensees, as well as reporting on it in prior BWR SERs.
As a result of the staff's pursuing the matter, the fuel manufacturer has told us that they have taken specific steps to deal with the material variability problem and further informed their customers about the importance of maintaining proper water chemistry to guard against this problem through an information letter.
In particular, I am closing this issue for WPPS-2 because (a) the staff has made the applicant aware of the potential for such fuel failurcs, (b) the aoplicant has expressed a sensitivity to the issue and will take special precautions to operate with attention to water chemistry, (c) the applicant has a surveillance program that would detect such failures should they occur, and (d) the applicant has strong economic incentive to prevent failed fuel (the approximate cost of a 3WR-fuel-assembly is on the order of 3/4 of a million).
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s C. Carlinger M J0 W In summary, there is currently no staff regulatory requirement to deal with this issue; nor do I believe one is necessary at this time.
However, I will continue to monitor the situation and encourage the Fuels Section to call to my attention any new infomation dealing with this matter.
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L. S. Rubenstein, Assistant Director for Core and Plant Systems Divisio:. of Systems Integration cc:
R. Mattson D. Eisenhut R. Tedesco T. flovak R. O. Meyer M. Tokar c mcn >
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