ML20236E463
| ML20236E463 | |
| Person / Time | |
|---|---|
| Issue date: | 02/26/1986 |
| From: | Vollmer D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | Taboada A NRC |
| Shared Package | |
| ML20236E258 | List: |
| References | |
| FOIA-87-666 NUDOCS 8710290232 | |
| Download: ML20236E463 (2) | |
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,p***%'*g UNITED STATES NUCLEAR REGULATORY COMMISSION
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.I WASHINGTON, D.C. 20555 2/26/86 DIRECTOR'S OF FICE OFFICE OF INSPECTION AND ENFORCEMENT Alfred Taboada For your information.
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- The Ohio State University Department of -
i Metallu,gical Engineenng 141 A Fontana Laboratories 116 West 19th Avenue Columbus, Ohio 43210-1179 t
Phone 614-422 2491 February 16, 1986
.Mr. Jack Guillaimin Monroe Power Plant POB 731 Monroe Mich 48161
Dear Jack,
Herewith is the report I wrote for the ACRS after my informative h
-visit to the Monroe Plant.
If you feel I have made any mistakes in the.,e d l
facts I report, I wou.1d appreciate hearing about it.
j, i A" '
I don't know what your metallurgists have found, but I was struck fcd by the similarities between the failure morphology at Monroe and that reported for a steam pipe in 'IVA's Colbert 5 plant (F.V. Ellis, S.O.
Hilton, J.F. Henry, J.E. Bynum, ' Influence of Service Exposure on Base and Weld Metal of 0.5Cr-0.5MD-0.25V High-Pressure Steam Inlet Piping,"
Trans. A!ME JNL PRES VESSEL TBCH 191 (1982) 120-129.) They conclude the failure is caused by creep-rupture but in a narrow region between the HAZ and the base metal. W is is consistent with what I have in my memo except that I believe that stean corrosion may play a role in the accelerated localized cracking. %e local decarburization expected from this corrosion mechanism may also be shown in the paper.
As a research metallurgist I find it a very interesting fracture.
As an advisor to a regulatory agency I find it troubling that the failure occurred under conditions far from what either FAA or the ASME Code would i
predict. It makes me wonder how many more we will see before we learn i
what really caused the failures and how to predict them.
Many of us connnected with the NIC look forward to learning more about what you find as your investigation procedes.
Sincerely, Paul Shewnon Professor Lc6: R. Vollmer 1
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