ML20010H886
| ML20010H886 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/18/1981 |
| 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, NUDOCS 8109290386 | |
| Download: ML20010H886 (2) | |
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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 400 Chestnut Street 7bwer II a b 3s
,,,,, j. 7 September 18, 1981 Sg10-50-328/81-30 My O,y s
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S Mr. James P. O'Reilly, Director
'(dh Office of Inspection and Enforcement ce ' d
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Q<p@,f, U.S. Nuclear Tegulatory Commission Region II - Suite 3100 f/
101 Marietta Street
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Atlanta, Georgia 30303
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Dear Mr. O'Reilly:
FBQUOYAH NLCLEAR PIANT UNIT 2 - EDAM SEALS IN MBCHANICAL PIPE SLEENES -
SQRD-50-328/81 THIRD INfERIM REPORP The subject deficiency was initially reported to NBC-OIE Inspector R. V. Crlenjak on April 16, 1981, in accordance with 10 CFR 50.55(e) as ?CR CEB 8108. Interim reports were submitted on April 23 and June 30, 1981. Enclosed is our third interim report. We expect to submit our next report by November 19, 1981.
If you have any questions, please get in touch with D. L. Lambert at PPS 857-2581.
Very truly yours, TENNESSEE VALLEY AITIHORITY N
L. M. Mills.iManager Nuclear Ibgulation and Safety Enclosure cc: Mr. Victor Stello, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Cmmission Washington, DC 20555 YY s
ih 8109290386 810918" PDR ADOCK 05000328 s
PDR:
An Eqt,al opportunity Employer
9
...* e DCIDSURE SEQUOYAH NUCLFAR PL*"f UNIT 2 FOAM SEALS IN MIDIANICAL PIPE SLEENES SQRD-50-328/81-30 10 CFR 50.55(e)
THIRD INTERIM REPORT Description of Deficiency Some wall penetration piping sleeves shown on TVA drawing series 47N470 and 47W471 have rigorously analyzed safety-relatal piping routed through them.
Silicone sealants are provided between the pipe and sleeve at certain locations as shown on TVA drawing series 47W472. Wese seals have not been considered by the piping analyst for most cases and thereby could result in increases in pipe stresses and support loads for some situations. We maximum pipe movements at the sleeves may cause failure of the sealant to perform its intended design function as a pressure, water, radiation, and/or fire protection seal.
Interim Progress TVA has conducted tests which show that the silicone foam is flexible in tension, compression, and shear. Test results and vendor physical data indicate the silicone foam will not tear or rupture for anticipated pipe movements.
In cases where the pipe is not centered, the movement of the pipe could tear the seal locally; however, a complete loss of a seal through a penetration is not likely.
TVA is currently evaluating the effects of the silicone foam seals on the pipe and on the seal itself. Pipe novement data has been compiled for the evaluation.
From the test, conducted by TVA, on silicone foam seal, spring rates for the foam seal in tension, compression, and shear have been established for use in the analysis to represent the resistance offered by the seal in the sleeve for pipe novements.
Six analysis problems have been selected that have seal.s that penetrate the i
shield building at critical elevations and have large pipe movements at the sleeve. %us far analysis on three problems har been completed, and the results indicate no significant increase in the pipe stresses or support loads. Analysis on the remaining three problems is in progress.
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