ML19323F276
| ML19323F276 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/19/1980 |
| From: | Counsil W NORTHEAST NUCLEAR ENERGY CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19323F277 | List: |
| References | |
| IEB-79-13, NUDOCS 8005280720 | |
| Download: ML19323F276 (2) | |
Text
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NORTHEAST UTil.ITIES
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HARTFORD COH4ECTICUT 04101 bb hb '$l kl L, J May 19, 1980 Docket No. 50-336 Director of Nuclear Reactor Regulation Attn:
Mr. Robert A. Clark, Chief Operating Reactors Branch #4 U. S. Nuclear Regulatory Commissinn Washington, D.C.
20555
References:
(1)
B.11. Grier letter to W. G. Counsil dated June 25, 1979, transmitting I&E Bulletin No. 79-13.
(2)
B.11. Grier letter to W. G. Counsil dated October 17, 1979, transmitting I&E Bulletin No. 79-13, Revision 2.
(3)
W. G. Counsil letter to R. Reid dated December 7, 1979.
(4)
- 11. R. Denton letter to W. G. Counsil dated April 4, l930.
Gentlemen:
Millstone Nuclear Power Station, Unit No. 2 Fec4 water Piping System Reference (1), as supplemented by Reference (2), requested that Northeast Nuclear Energy Company (NNECO) inspect portions of the feedwater piping s, stem at Millstone Unit No. 2.
As a result of these inspections, circumferential cracking was detected on both sides of the steam generator safe-end to pipe welds and the adjacent pipe to elbow welds in both feedwater loops.
NNECO proceeded with a repair program which was described in Reference (3).
The repair program yielded limited metallurgical specimens; however, metallurgical specimens containing cracks from the elbow side of the elbow to pipe weld (BC-G-2) and elbow base material from feedwater loop #2 were obtained and examined. The results of these examinations are contained in the attached report
" Millstone Unit No. 2, Steam Generator No. 2 Feedwater Pipe Failure Analysis".
Contrary to the information presented by the NRC Staff in Reference (4),
the attached report provides metallographic results which document that actual crack depths were indeed " bounded" by the crack depth measurements ob.ained by NNECO through the ultrasonic examinations.
7 THIS DOCUMENT CONTAINS 8005280 7 10 POOR QUAUTY PAGES3
.* a NNECO is providing'this report to the NRC Staff for informational purposes.
In this fashion, the Staff may factor the results obtained from Millstone Unit No. 2 into the overall data base on the subject concern.
We trust you will find this information of benefit in your determination of the phenomena associated with cracking in the feedwater piping systems.
Very truly yours, t
NORTHEAST NUCLEAR ENERGY COMPANY j'
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W'. G. Counsil l
Vice President Attachment i
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