ML20196E038
| ML20196E038 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/07/1988 |
| From: | Hairston W GEORGIA POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| IEB-88-009, IEB-88-9, X7GJ17-V110, NUDOCS 8812090261 | |
| Download: ML20196E038 (2) | |
Text
Georgfa F%er Company.
333 Piedmont Avenue ~
~4 Atlanta. Geor0ia 30308 blephone 404 526-3195 Mailing Add <ess-t O f ce 95 Birmogham, Alabama 35201 Telephone 205 868-5581 1*e scwevn ecc!nc systevn W. G. Hairston, til gggc,'Sj"'
December 7, 1988 X7GJ17 V110 ELV-00063 08320 U. S. Nuclear Regulatory Connission ATTN:
Document Control Desk Washington, D. C.
20555 l
PLANT YOGTLE - UNIT 1 NRC DOCKET 50-424 OPERATING LICENSE NPF-69 RESPONSE TO NRC BULLETIN 88-09 l
Gentlemen:
NRC Bulletin 88-09 requires submittal of a written response that a) confirms that an inspection program consistent with that requested in Action Item 1 of a
the Bulletin has been established and b) confirms that inspections of the thimble tubes have been performed and that appropriate corrective actions were taken. The Bulletin requests this response within 30 days of completion of the thin:' ale tube inspections.
Thimble tube inspections as required by Bulletin 88-09 were completed for Vogtle Unit 1 on November 10, 1983. The inspections were performed by the Westinghouse Nuclear Service Division and consisted of eddy :urrent testing for each of the flux thimble tubes.
Inspection results revealed wall loss indications on twenty (20) of the fif ty-eight (58) thimble tubes due to external wear at suppcrt locations.
The indicated wall loss ranged from a minimum of 16% for one thimble to a maximum of 40% for one thimb.e.
Westinghouse states that the accuracy of their eddy current testing is + 10%.
In addition, Westinghouse states that the allowaile wall loss criteria Ts 60%
of wall thickness.
The Westinghouse evaluation of our data concluded that all thimble tubes were found to be acceptable for continued operation provided proper corrective action was taken.
Predictions were made by Westinghouse regarding the anticipated wall loss which could exist by the end of the next 18 month operating cycle if no corrective actier, was taken. These predictions were based on the understanding that the observed wall losses occurred within the first 18 -) nth operating cycle.
Based on the Westinghouse predictions, twelve (12) of %e l
f thimble tubes could have exceeded the 60% maximum wall loss acceptance criteria before the end of the next 18 month cycle. To preclude this possibility, Westinghouse recommencea corrective actiun to repositiar.
(withdraw) these twelve (12) thimble tubes approximately two (2) inches before returning Unit 1 to power. Repositicling of these twelve (12) thimble tubes was completed November 12, 1988.
4 f
GG12090261 881207
\\
PDR ADOCK 05000424 g
Q PDC
4 GeorgiaPower A U. S. Nuclear Regulatory Commission December 7, 1988 Page Two Since thimble tube thinning was indicated by this inspection, GPC will reinspect the Unit 1 thimble tubes during the next refueling outage. Once this second inspection is performed, it will be possible to refine the wall loss predictions for the future cycles and therefore determine whether r
inspection during each future refueling outage will be warranted.
Unit 2 thimble tubes will be inspected during the first Unit 2 refueling outage as required by the Bulletin.
Mr. W. G. Hairston, III states that he is a Senior Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company and that, to the best of his knowledge and belief, the facts set forth in this letter are true.
GEORGIA POWER COMPANY By: it/ /bM m W. G. Hairston, III Sw n to and su scribed before me this 7th day of December, 1988.
Cl, '
j/ Notary PubG fc t.4y.tg HMAJORS/1jb c: Georgia Power Company Mr. C. K. McCoy Mr. G. Beckhold, Jr.
Mr. W. B. Shipman Mr. R. J. Florian U. S. Nuclear Regulatory Commission Mr. M. L. Ernst Acting Regional Administrator Mr. J. B. Hopkins, Licensing Project Manager, NRR (2 copies)
Mr. J. F. Rogge Senior Resident Inspector - Operations, Vogtle.
F t
_ _ _. _