ML20023C538
| ML20023C538 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 04/26/1983 |
| From: | Rajan NRC |
| To: | |
| Shared Package | |
| ML19301C276 | List: |
| References | |
| NUDOCS 8305170413 | |
| Download: ML20023C538 (3) | |
Text
{{#Wiki_filter:4en .. - - _ b. g a 55 .5
- l MR. GOLDBERG:
Dr. Rajan wanted to say something. . p,', h i l ,a exv .7 A. (Witness Rajan) I'd like to point out that the wear E T.di.
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rate is dependent on the tube rubbing against the support plate hk;f*k a n3E j L. ~..:p fj.g# and as the gap between the tube and the support plate increases m.u the rubbing and the impacting force increases and, consequently ) d4 pY V the wear rate increases, and that's essentially what the differ-gp-DjM ence is; however, I would like to point out that after the fQ* kb tubes have been expanded in the support plate, the gap would p, reduce substantially, and this impacting and rubbing force will pe then consequently go down dramatically. 4 G And at that time when the tubes are expanded, they'l l be expanded in the D-4 as well as the D-5 at Byron? A. Yes. _.~e.p 4..,.. O And the D-4 has, though, carbon steel support plates f N so you're going to reduce the crevice area between the tube and tbc support plate, in fact, are you not? 3 c. l A. They will be-- Yes, they will be reduced to-- 9,- ,., M [ l 0 Well-- 7 4 MR. GOLDBERG: Can he finish his answer, please? g e t, C'p,U)% 1 l MS. CHAVEZ: Sure. 4.%;f l ' t :. uk 1 4.t.m$- BY MS. CHAVEZ: h- ( G Have you finished? ' " ' f2 t l w ^ A. The gap between the nornial support plate is, I }L.e 1 .x k5~' believe, of the order of 20 mills. It would be reduced co-- 4 .f c l .+ 5 '- I l at the closest point, it would be like "i' g.' ' p 8305170413 830426 L PDR ADOCK 00000454 i T Pop i
Ikg. l 4692 24 1 G That's right. So that opens the possibility for f: 2 corrosion products to collect on the support plate in that gap ff_ Yi 3 you know, as happens in other typical types of corrosion. So, y; "i in other words, if the tube is not carefully monitored, doesn' t og 5 that result in a possibility of increased corrosion? }[e. MR. GOLDBERG: I object to the form of the question 4 I'm not sure whether that's a statement or a cuestion, but { there's--maybe there's a witness on the panel that can give a .[ f responsive answer, but-- 2 A (Witness Frank) Let me try to respond. At the g-{ last presentation ten days ago, or two weeks ago, this concern 33 which people had, I guess, expressed previously--there was a [ presentation by which Westinghouse showed that they took tubes .3- '::su and support plates, expanded them by the process that was to Tt(i . +. E be done. There was a gap. They took other tubes 4'a., c with the preventional gap. They filled :this gap with what we
- . s now know are denting constituents, copper chloride, copper f
. j.s e oxide, magnetite, the types of things that would form should j5G Y. there be the corrosion which would lead to support-plate n)gg denting. 5M W Nbi' They ran these temperatures which they would see in f h.j,Q. .w the hot leg. Now, this is a very critical ooint. Denting-- . }[ h{; in and the question was: Would we experience any denting? You py.pe j zy.:;*. would have to get these corrosion plates, but the results of hv af these tests showed that there war no more extreme dentin,g with g[ k n .-e-M m
~ 'r 4699 obtaining results to s6a whit would be the effects of f 1 2 expanding those tubes at Byron?
- x 3
A That essentially was the idea. But it was not / E 4 part of the fix for Krsko. { 0 5 G Okay. / Yi 6 A Krsko is relying on the 30-70 split as the sole t-j 7 modification for relieving the excessive vibrations, f n 8 g Okay. Is that tube that was expanded at Krsko 9 representative of all the 100 tubes which will be expanded j! 10 at Byron? [ -k 11 A Essentially. There might be a difference in the 12 location, but the technique for expansion would be the 4 13 same. + 14 Do you know what that technique is' 15 A My understanding is that it is hydraulic 16 expansion of the tube just within the support plate--not the i 17 support plate; excuse me--the baffle B location, and it will t is be a controlled expansion, which would expand the tube t i- + ig from the 20-mill original gap to gap, thus 4, C allowing the tube to move within the tube. sg 20
- d A
(Witness Frank) I might have to add something ,2 21 . gin to that, because the hydraulic expansion, as I understand pl. 22 g it, is similar to the expansion they do in the tube. (9 23 t;' G Isn't it in fact the same? $.~ 24 l IS^ MR. GOLDBERG: I'm not sure we had a complete 25 4% 6 -h m -}}