ML19256E697
| ML19256E697 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 10/29/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| NUDOCS 7911150031 | |
| Download: ML19256E697 (1) | |
Text
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Docket No. 50-213 OCT 2 9149 Connecticut Yankee Atcmic Power Company ATTN:
Mr. W. G. Counsil Vice President - Nuclear Engineering and Operations P. O. Box 270 Hartford, Connecticut 06101 Gentlemen:
The enclosed IE Bulletin 79-17, Revision 1 is forwarded to you for action.
A written response is required. If you desire additional information regarding this matter, please contact this office.
Sincerely, m
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Boyce
. Grier Director
Enclosures:
1.
IE Bulletin No. 79-17, Revision 1 w/ Attachment 2.
List of IE Bulletins Issued in the Last Six Months CONTACT:
L. E. Tripp 215-337-5282 cc w/encls:
R. Graves, Plant Superintendent D. G. Diedrick, Manager of Quality Assurance J. R. Himmelwright, Licensing Safeguards Engineer 1337 282 791115003!
ENCLOSURE 1 UNITED STATES SSINS No.:
6820 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 7908220157 WASHINGTON, D.C.
20555 3
IE Bulletin No. 79-17 Revision 1 Date:
October 29, 1979 Page 1 of 5 PIPE CRACKS IN STAGNANT BORATED WATER SYSTEMS AT PWR PLANTS Description of Circumstances:
IE Bulletin No. 79-17, issued July 26, 1979, provided information on the R1 cracking experienced to date in safety-related stainless steel piping R1 systems at PWR plants.
Certain actions were required of all PWR R1 facilities with an operating license within a specified 90-day time R1 frame.
After several discussions with licensee owne group representatives and R1 inspection agencies it has been determined that the requirements af Item 2, R1 particularly the ultrasonic examination, may be impractical because of un-R1 availability of qualified personnel in certain cases to complete the in-R1 spections within the time specified by the Bulletin. To alleviate this R1 situation and allow licensees the resourc'.?s of improved ultrasonic inspec-R1 tion capabilities, a time extension and clarifications to the bulletin have R1 been made.
These are referenced to the affected items of the original R1 bulletin.
During the period of November 1974 to February 1977 a number of cracking incidents have been experienced in safety-related stainless steel piping systems and por-tions of systems which contain oxygenated, stagnant or essentially stagnant bor-ated water.
Metallurgical investigations revealed these cracks occurred in the weld heat affected zone of 8-inch to 10-inch type 304 material (schedule 10 and 40), initiating on the piping I.D. surface and propagating in either an inter-granular or transgranular mode typical of Stress Corrosior. Cracking.
Analysis indicated the probable corrodents to be chloride and oxygen contamination in the affected systems.
Plants affected up to this time were Arkansas Nuclear Unit 1, R. E. Ginna, H. B. Robinson Unit 2, Crystal River Unit 3, San Onofre Unit 1, and Surry Units 1 and 2.
The NRC issued Circular No. 76-06 (copy attached) in view of the apparent generic nature of the problem.
During the refueling outage of Three Mila Tel=ad HM+ '
'3-'
2-of this year, visual inspections disc 1 in the spent fuel cooling system pipin removal system.
These cracks were fou and later confirmed by liquid penetran DUPLICATE DOCUMENT cracking was reported to the NRC in a 1979.
A preliminary metallurgical ana Entire document previously section of cracked and 1 g weld jo entered into system under:
ANO R1 - Identifies those additions or rev No. of pa es: