ML19256E698
| ML19256E698 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/29/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 7911150032 | |
| Download: ML19256E698 (1) | |
Text
{{#Wiki_filter:N [pa ntauq(o, UNITED STATES ',g NUCLEAR REGULATORY COMMISSION y 'e 3." - j REGION I 0, g 631 PARK AVENUE %,'%#*,o# KING OF PRUSSIA, PENNSY LV ANI A 19406 Docket No. 50-334 OCT 2 9 jg73 Duquesne Light Company ATTN: Mr. C. N. Dunn Vice President Operations Division 435 Sixth f. venue Pittsburgh, Pennsylvania 15219 Gentlemen: The enclosed IE Bulletin 79-17, Revision 1 is forwarded to you.cr action. .\\ written response is required. If you desire additional information regarding this matter, p ase contact this office. Sincerely, m p / f n Boyce H. 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: F. Bissert, Technical Assistant Nuclear R. Washabaugh, QA Manager J. Werling, Station Superintendent G. Moore, General Superintendent, Power Stations Department J. J. Carey, Nuclear Technical Assistant R. Martin, Nuclear Engineer 1337 284 7 911 15 0 G3 2.
ENCLOSURE 1 UNITED STATES SSINS No.: 6820 NUCLEAR REGULATORY COMMISSION Accession No.: 0FFICE 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 80 RATED 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 ai, PWR R1 facilities with an operating license within a specified 90-day time R1 frame. After several discussions with licensee owner group representatives and R1 inspection agencies it has been determined that the requirements of 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 resources of improved ultrasonic inspec-R1 tion capabilities, a time extension and clarifications to the bulletin have R1 been made. These are referenced to the affer.ted items of the original R1 bulletin. During the period of November 1974 to February 1977 a number cf cracking incidents have been experienced in safety-related stainless steel piping systems and par-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 Corrosion 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 Mile Isl of this year, visual inspections disc 1 in the spent fuel cooling system pipin removal system. These cracks were fou DUPLICATE DOCUMENT and later confirmed by liquid penetran cracking was reported to the NRC in a Entire acument previously 1979. A preliminary metallurgical anal entered into s stem under-section of cracked and leaking weld joi $Y ANO N o. of pages: R1 - Identifies those additiors or revi =}}