ML19256E766
| ML19256E766 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/29/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Stewart W FLORIDA POWER CORP. |
| Shared Package | |
| ML19256E767 | List: |
| References | |
| NUDOCS 7911150170 | |
| Download: ML19256E766 (2) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION o
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101 MARIETTA ST., N.W., tulTE 3100 g
o ATLANTA, G EORCIA 30303 OCT 2 91979 In Reply Refer To:
RII:JPO 50-302 Florida Power Corporation Attn:
W. P. Stewart, Manager Nuclear Operations P. O. Fox 14042, Mail Stop C-4 St. Petersburg, Florida 33733 Gentlemen:
The enclosed Bulletin No. 79-17, Revision 1 is forwarded to you for action. A written rerponse 1r required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
% ~
James P. O'Reilly Director
Enclosure:
IE Bulletin No. 79-17, Revision I w/encls.
1338 279 7911150 /7 0
OCT 91979 Florida Power Corporation,
cc w/ encl:
G. P. Beatty, Jr.
Nuclear Plant Superintendent Post Office Box 1240 Crystal River, Florida 32629 1338 280
UNITED STATES SSINS No.: 6820 NUCLEAR REGULATORY COMMISSION Accession No.:
NTICE OF INSPECTION AND ENFORCEMENT 7908220157 WASHINGTON, D.C.
20555 3
October 29, 1979 IE Bulletin Na. 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, provided information on the cracking R1 experienced to date in safety-related stainless steel piping syctems 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, particulariy 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 Licensee Event Report (LER) dated May 16, 1979. A preliminary metallurgical analysis was performed by the licennaa =-
section of cracked and leaking weld joi
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