ML19256E875
| ML19256E875 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 10/29/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 7911150466 | |
| Download: ML19256E875 (1) | |
Text
p alcoq'c (jD UNITED STATES j y :,.c.: c *( 7.
NUCLEAR REGULATORY COMMISSION
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1990 N. C AL FORP I BOULEVAHD 0,
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WALNUT CHEEK, CALIFORNI A 94596 October 29, 1979 Docket flo. 50-344 Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Attentior.:
Mr. Chsries Goodvlin Assistant Vice President Gentlemen:
The enclosed Bulletin fio. 79-17, Revision 1 is forwarded to you for action. A written response is required.
If you desire additional information regarding this natter, please contact this office.
Sinc *ely, Ll2 -c<) macd w-R. H. Engelken Director
Enclosure:
IE Bulletin flo. 79-17, Revision 1 cc w/ enclosure:
C. P. Yundt, PGE F. C. Gaidos, PGE 1339 045 7911150
UNITED STATES SSINS tio.:
6820 NUCLEAR REGULATORY COMISSIOil Accession No.:
0FFICE OF INSPECTION AtlD ENFORCEMENT 79082201l7 WASHINGTON, D.C.
20555 October 29, 1979 IE Bulletin No. 79-17 Revision 1 PIPE CRACKS IN STAGNANT B0 RATED WATER SYSTEMS AT PWR PLANTS Description of Circumstances:
IE Bulletin No. 79-17, issued July 26, 1979, provided information on the cracking R1 experienced to date in safety-related stainless steel piping systems at PWR R1 plants.
Certain actions were required of all PWR facilities with an operating R1
. license within a specified 90-day time frame.
R1 After several discussions with licensee owner group representatives and inspection R1 agencies it has been determined that the requirements of Item 2, particularly R1 the ultrasonic examination, may be impractical because of unavailability of R1 qualified personnel in certain cases to complete the inspections within the time R1 specified by the Bulletin.
To alleviate this situation and allow licensees the R1 resources of improved ultrasonic inspection capabilities, a time extension and R1 clarifications to the bulletin have been made. These are referenced to the R1 affected items of the original bulletin.
R1 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 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 enclosed) in view of the apparent generic nature of the problem.
During the refueling outage of Three Mile Island Unit I which began in February of this year, visual inspections disclosed five (5) through-wall cracks at welds in the spent fuel cooling system piping and one (1) at a weld in the decay heat removal system. These cracks were found as a result of local boric acid buildup and later confirmed by liquid penetrant tests.
This initial identification of cracking was reported to the NRC in a Lic dated Ma 16, 1979. A preliminary metallurgical analys section of cracked and leaking weld joint DUPLICATE DOCUMENT Entire document previously R1 - Iden;ifics Jme additions or revisi entered into systam und
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