ML19256E692
| ML19256E692 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/29/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7911150024 | |
| Download: ML19256E692 (1) | |
Text
a ato 74
,{pa oq%
=
UNITED STATES y ))
(( j NUCLEAR REGULATORY COMMISSION 34
/;- y REGION I 0, 'f.
g 631 PARK AVER 4UE o
KING OF PRUSSIA, PENNSYLVANIA 19406 Docket Nos. 50-317 50-318 GCT 2 91919 Baltimore Gas and Electric Company ATTN:
Mr. A. E. Lundvall, Jr.
Vice President, Supply P. O. Box 1475 Baltimore, Maryland 21203 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, g ~~
oyce
. Grier Director
Enclosures:
1.
IE Bulletin No. 79-T.7, Revision 1 w/ Attachment 2.
List of IE Bulletin Issued in the Last Six Months CONTACT:
L. E. Tripp 215-337-5282 cc w/encls:
R. M. Douglass, Manager, Quality Assurance L. B. Russell, Chief Engineer W. Gibson, General Supervisor, Operational QA R. C. L. Olson, Senior Engineer K. H. Sebra, Principal Engineer 1337 237 7 911150 O L4
ENCLOSURE 1 UNITED STATES SSINS No.:
6820 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 7908220187 WASHINGTON, D.C.
20555 J
IE Bulletin No. /5-17 Revision 1 Date:
October 29, 1979 Page 1 of 5 PIPE CRACKS IN STAGNANT BORATED WATER SYSTEMS AT PWR PLANTS Description of Circumstances:
IE BC letin 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 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 avaihbility of qualified personnel in certain cases to complete the in-R1 spections within the tilna specified by tiie Bulletin. To alleviate this R1 situation and allow lictasees 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 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-irch 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 viu of the apparent ~ generic nature of the problem.
During the refueling outage of Three M of this year, visual inspections disci in the spent fuel cooling system pipin removal system.
These cracks were fou DUPLICATE LOCUMENT and later confirmed by liquid penetran cracking was reported to the NRC in a Entire document Previously 1979.
A preliminary metallurgical ana entered into system under:
section of cracked and leaking weld o ff R1 - Identifies those additions or rev No. of Pages: