ML19329E438
| ML19329E438 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 03/31/1976 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8006160240 | |
| Download: ML19329E438 (1) | |
Text
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m UNITED STATES NUCLEAR REGULATORY COMMISSION REGION lli 799 ROOSEVELT RO AD CLEN ELLYN. ILLINOIS 60137 l
March 31, 1976 Corsumers Power Company Docket No. 50-329 ATIN: Mr. Stephen H. Howell Docket No. 50-330 Vice President 1945 West Parnall Road Jackson, Michigan 49201 Gentlemen:
Enclosed is IE Bulletin No. 76-04 which is forwarded to you for information. No action is required of you if you do not have a boiling water reactor with operating license.
Should you have gtiestions regarding this Bulletin, please contact this office.
Sincerely yours, James G. Kappler Regional Director Enclosura IE Bulletin No. 76-04 e
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THIS DOCUMENT CONTAINS bec w/ enc 1:
IE Central Files POOR QUALITY PAGES IE Files PDR Local PDR OGC, Beth, P-506A Ronald Callen, Michigan Public Service Commission Dr. Wayr.e E. North Myron M. Cherry, Chicago 8006160N4/O
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March 31, 1976 IE Bulletin No. 76-04 CRAC,,3 IN COI.D WORKED PIPING AT BWR'S DESCRIPTION OF CIRCUMSTANCES:
On' March 22, 1976, at the Nine Mile Point 1 facility, a leak was found in a reactor. water clean-up system six-inch stainless steel pipe located outside of the drywell..The leak resulted i
from a throughwall crack in the base material at a pipe bend.
Similar leaks had been experienced in this system on November 28, 1975 and March 19, 1976. The cracks do not appear to have any preferred orientation. The-facility was shutdown on March 22 to permit nondestructive examination of the base material at
-similar-pipe bends.
The' piping involved is schedule 80, ASTM A-376, Type 304 stainless steel which had undergone cold bending during fabrication without subsequent solution annealing.
Examination
.of the pipe section which leaked on November 28, 1975, revealed that the crack initiated in the transgranular mode at the inside surface and changed to the intergranular mode after it had I
propagated through.the cold' worked surface.
Significant carbide j
precipitation around grain boundaries was observed although
-the reason for this precipitation is not known at this time.
The cracking mechanism was categorized as stress corrosion.
.The stress field is believed to be caused by cold forming.
1 ACTION TO BE TAKEN BY LICENSEES:
1
~All licensees of BWR power reactor facilities are to take the following. action:
l.
Develop the following information for those systems located within, or connected to, the reactor coolant pressure boundary and which are exposed to reactor coolant system pressure during operation:
a.
A specific listing of installed austenitic stain-less steel piping or fittings made from pipe, greater than two inches nominal size, which may
-have been cold worked without solution annealing following forming.
(Verification that cold worked material received full solution annealing following the forming operation'must be based on acceptable time-temperature heat treating records, metallurgical analyses, or equivalent and may be on a sampling i
basis for each lot number.)
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IE Bulletin No. 76-04 2-March 31, 1976 b.
A_ description of the program and procedures, including inspection criteria and schedules, for the nondestructive volumetric examination of the items identified in (a) above.
L2, A' report of the above applications, descriptions, plans and schedules should be submitted withi.n 60 days after receipt of this Bulletin.
3.
The NRC Regional Office should be promptly informed, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, of any adverse findings resulting
'during nondestructive evaluation of identified piping or fittings.
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A-report of.the performance, the results, and the evaluation of any nondestructive evaluation conducted on cold worked scainless steel piping or fittings should be submitted within 60 days following completion of the examination.
Reports should be submitted to the Director of the NRC Regional Office and a' copy should be forwarded to the NRC Office of Inspection and Enforcement, Division of Reactor Inspection Programs, Washington, D. C.
20555.
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Approval of NRC requirements for reports concerning possible generic problems has been obtained under 44 U.S.C. 3152 1
from the U. S. General Accounting Office.
(GAO~ Approval B-180255(R0072), expires 7/31/77).
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