ML19254F080
| ML19254F080 | |
| Person / Time | |
|---|---|
| Site: | Marble Hill |
| Issue date: | 10/29/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Shields S PSI ENERGY, INC. A/K/A PUBLIC SERVICE CO. OF INDIANA |
| References | |
| NUDOCS 7911060138 | |
| Download: ML19254F080 (1) | |
Text
p= **o E[y,' 7m]o, UNITED STATES j
NUCLEAR REGULATORY COMMISSION
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REGION 111 o,.f f
799 ROOSEVELT ROAD
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GLEN ELLYN ILLINOIS 60137 "IT9 Docket No. 50-546 Docket No. 50-547 Public Service of Indiana ATTN:
Mr. S. W. Shields Vice President - Electric System 1000 East Main Street Plainfield, IN 46168 Gentlemen:
The enclosed IE Bulletin No. 79-17, Revision 1 is forwarded to you for information. No written response is required.
However, the potential corro-sion behavior of safety related systems as it regards your plant over the long term should be taken into consideration.
If you desire additional information concerning this matter, please contact this office.
Sincerely,
. _ h k = Oa_ _
ames [ Kepp Mr Director
Enclosure:
IE Bulletin No. 79-17, Revision I cc w/ encl:
Mr. R. M. Brown, Construction Project Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC LeBoeuf, Lamb Leiby & MacRae kt t r$ a rne l}gl
] 7911060136
UNITED STATES 551N5 No. "6820 NUCLEAR REGULATORY COMMISSION Atcession No. OFFICE OF INSPECTION AND ENFORCEMENT 79082201$7 WASHINGTON, D.C. 20555 3 October 29, 1979 IE Bul1etin Nv. 79-17 Revision 1 PIPE CRACKS IN STAGNANT BORATED WATER SYSTEMS AT PWR PLANTS Description of Circumstances: IE Bulletin No. 79-17, issued July 26, 1979, experienced to date in safety-related stainless steel piping systems at PWRprovi plants. license within a specified 90-day time frame.Certain actions were required o R1 R1 R1 After several discussions with licensee owner group representatives and inspection R1 agencies it has been determined that the requirements of item 2, particularly 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. R1 To alleviate this situation and allow licensees the R1 clarifications to the bulletin have been made. resources of improved ultrason R1 affected items of the original bulletin. These are referenced to the R1 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 tnese 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 1.D. surface and propagating in either an inter-granular or transg" anular mode typical of Stress Corrosion Cracking. indicated the probable corrodents to be chloride and oxygen contamination in the Analysis 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. of the apparent generic nature of the problem.The NRC issued Circular No. 76 During the refueling outage of Three Mile Island Unit 1 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 tne decay heat removal system. and later confirmed by liquid penetrant tests.These cracks were found as a res This initial identification of cracking was reported to the NRC in a Licensee Event Report (LER) dated May 16, 1979. A preliminary metallurgical analysis was performed by the licensee on a section of cracked and leaking weld joi R1 - Identifies those additions or revi DUPLICATE DOCUMENT Entire document previously entered into system under: 1291 153 MM226/X 7 oO No. of pages:
D D D ~T 3 A a v f\\ a A. . S M = Nove2ber 26, 1976 II Circular No. 76-06 STRESS CORROSION CMCKS IN STACNANI,14W PRISSURI STAIh*1J.SS PIP 1NG CONTAINING BORIC ACID SOLUTION AT PWR's DESCRIPTION OF CIP.CD1 STANCES: During the period November 7, 2 974 to November 1,1975, ceveral incidents of through-wall cracking have occurred in the lO-inch, schedule 10 type 304 stainless steel piping of the Reactor Building Spray and Decay Eeat Re= ova) Systa=s at Arkansas Nuclear Plant No.1. On October 7,1976, Virginia Electric and Power also reported through-vall cracking in the 10-inch schedule 40 type 304 stainless dischar e piping of the "A" recirculation spray heat exchanger at Surry Unit No. 2. A recent inspection of Unit 1 Containnent Recirculation Spray Piping revealed cracking zinilar to Unit 2. On Cetober 8,1976, another incident of similar cracking in 8-inth schedule 10 type 304 stainless piping of the 5:fety injection Punp Suction 1.ine se the Cinna facility was reported by the licensee. Infor:.ation received on the natallurgical analysis conducted to date indicates that the failures were the result of intergicnular stress corrosion cracking that initiated on the inside of the piping. A co==:nnlity of facters observed associated vitit the corrosion ce:hr..ist were: 1. The cracks were adjacent to and propagated along weld zones of the thin-valled low pressure piping, not part of the reactor coolant syster. 2. Cracking occurred in piping containing relatively stagnant boric acid solution cet required for normal operating cenditions. 3. Analysis of surface products at this time indicate a chloride ion interaction with oxide formation in the relatively stagnant borie acid solution as the probable corrodant, with the stata of stress probably due to velding and/or fabrication, The source of the chloride ion is not dafinitely known. Bovaver,,at ANO-1 the chlorides and sulfide level observed in the surface tarnish film near velds is bal.ieved to have been introduced into the piping during testing of the sodiu:n thiosulfate discharge valves, er valve leakage. Si=ilarly, at Cinna the chlorides and potential oxygen -1291 154 ouet1 cars ooconsNr Entire documee previously entered into system under: ANO h7 b I No. of pages: /o / i { .}}