ML19353A200
| ML19353A200 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/02/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NCR-SQN-NEB-802, NRC-SQN-NEB-802, NUDOCS 8101070429 | |
| Download: ML19353A200 (2) | |
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400 Chestnut Street Tower II January 2, 1981 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Comission Region II - Suite 3100 101 Marietta Street Atlanta, Georgia 30303
Dear Mr. O'Reilly:
SEQUOYAH NUCLEAR PLANT - STRESS CORROSION CRACKING IN TUBING CN THE REACTCH COOLANT PUMP OIL COOLERS - NCR SQN UEB 8028 - FIRST INTERIM REPORT The subject deficiency was initially reported to NRC-OIE Inspector R. W. Wright on December 2, 1980, in accordance with 10 CFR 50.55(e). Enclosed is our first interim report. We expect to submit our next report by February 3, 1981. We consider 10 CFR 21 applicable to this deficiency.
If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure cc:
Mr. Victor Stello, Jr., Director (Enclosure)
Office of Inspection and Enforcement j
U.S. Nuclear Regulatory Comission Washington, DC 20555
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4 ENCLOSURE SEOUOYAH NUCLEAR PLANT UNIT 2 j
STRESS CORROSION CRACKING IN TUBING ON THE REACTOR COOLANT PUMP OIL COOLERS NCR SONNEB8028 10CFR50.55 (e) i FIRST INTERIM REPORT Description of Deficiency Some reactor coolant pump lubricating oil coolers have developed excessive tube leakage due to stress corrosion cracking (SCC) in the tube material. Examination of the tube material removed from one such heat exchanger revealed that the tubes were of admirality i
brass rather than the specified 90-10 copper-nickel. Admirality brass has been found to be susceptible to stress corrssion cracking in this application due to the p'resence of ammonia, which in conjunction with residual and operating stresses, causes the stress corrosion cracking.
l The ammonia present is apparently a product of the decomposition of.
hydrazine from the component cooling system water treatment.
Interim Progress TVA has requested a quotation from Westinghouse to replace the unit 2 reactor coolant pump lubrication oil cooler tubing with 90-10 copper-nickel.
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