ML20081M521
| ML20081M521 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 11/07/1983 |
| 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-2424, NUDOCS 8311170291 | |
| Download: ML20081M521 (2) | |
Text
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TENNESSEE VALLEY AUTHORITY CH ATTANOOGA, TENNESSEE 374ot 400 Chestnut Street T8glp A
f *. Jg November 7,1983 BLRD-50-438/83-48 BLRD-50-439/83-40 U.S. Nuclear Regulatory Comission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 - HEAT TRACING TAPE LEFT ON PIPING VIOLATES G-29M - BLRD-50-438/83-48, BLRD-50-439/83 FINAL REPORT The subject deficiency was initially reported to NRC-OIE Inspector Linda Watson on July 29, 1983 in accordance with 10 CFR 50.55(e) as
'NCR 2424. This was followed by our interim report dated August 29, 1983 Enclosed is our final report.
Please note that TVA does not now consider the subject nonconforming condition adverse to the safe operation of the plant. Therefore, we will amend our records to delete the subject nonconformance as a 10 CFR 50.55(e) item.
If you have any questions, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Licensing Enclosure cc (Enclosure):
Mr. Richard C. DeYoung, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Comission Washington, D.C.
20555 Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500
. #9 Atlanta, Georgia 30339 ggLCM.Y.%
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DR TVA SOrH ANNIVERSARY t
An Equal Opportunity Employe
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b ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 HEAT TRACING TAPE LEFT ON PIPING VIOLATES G-29M NCR 2424 BLRD-50-438/83-48, BLRD-50-439/83-40 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Four types of adhesive tape have been used to permanently attach heat tracing to ' stainless steel instrument tubing. In the past, General Construction Specification G-29 has required the removal of all adhesive tapes prior to system operation due to the oossibility of stress corrosion cracking caused by leachable halogens. However, vendor drawings have shown that the heat tracing tape may be left on permanently.
Safety Imolications The four types of adhesive tape, procured from four different sources, have been shown by TVA testing to meet stringent requirements similar to those required of thermal insulation per Regulatory Guide 1 36. There fore,
the tapes can be left on stainless steel tubing or piping. The requirements these tapes have met are that they have total halogen contents less than 1,000 ppm and leachable halogen contents less than 100 ppm.
Also, they have been qualified via a modified Dana Wicking Test. In the modified Dana Wicking Test, tapes are applied to U-bend stainless steel stress corrosion cracking samples that have been heavily sensitized. These samples are then exposed to boric acid solutions at 205 F +50F in a wicking environment of purified glass wool for 28 days. Since no cracking of the U-bends was observed, the tape qualified.
General Construction Specification G-29M has been revised to allow the permanent application of pressure sensitive adhesive tapes for attaching heat tracing when they meet the above required chemistry tests and qualification via the modified Dana Wicking Test.
Inasmuch as the subject tapes can be left on stainless steel tubing or piping without any subsequent stress corrosion cracking due to leachable halides in the tapes, there are no adverse conditions that would adversely affect the safe operation of the plant. Therefore, we no longer consider 10 CFR 50.55(e) applicable.
P,
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