ML19350A287
| ML19350A287 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/05/1981 |
| 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-CEB-803, NUDOCS 8103130405 | |
| Download: ML19350A287 (2) | |
Text
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TENNESSEE VALLEY AUTHOP!TY CH A T ThNOOG A. TENNESSEE 37401 400 Chestnut Street Tower II March 5, 1981 Mr. James P.
eilly, Director Office of Insp on and Enforceaant U.S. Nuclear Regu tory Commission '*-
Regica II - Suite 3 101 Marietta Street Atlanta, Georgia 30303
Dear Mr. O'Reilly:
SEQUDYAH NUCuilAR PLANT UNIT 2 - THERIOT HEAT TRANSFER GMENT - NCR
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SQN GB 8036 - FINAL REPORT The subject deficiency was initially reported to NRC-OIE Inspector M. Thomas on November 26, 1980, in accordance with 10 CFR 50.55(e).
An interia report was submitted on December 29, 1980. Enclosed is our final report.
If you have any questions, please get in touch with D. L. Lambert at FTS 857-2581.
l Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Eagulation and
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ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 THERMON HEAT TRANSFER CEMENT NCR SQN CEB 8036 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency
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During an inspection required by" IE Eulletin 79-14, it was noted that heat transfer cement was installed over the heat tracing and piping in the area of all pipe hangers for process piping containing borated water (i.e., Safety Injection System, Chemical and Volume Control 4
System, and the Waste Disposal System). A subsequent evaluation of the use of heat transfer cement at all TVA nuclear plants determined that the problem exists at Sequoyah and Watts Bar. This was reported on Watts Bar as NCR WBN CEB 8103.,The cement was manufactured by Thermen Manufacturing Company but was installed by TVA. The cement is pliable when installed and fills all hanger and pipe clearances specified by the TVA construction specification. When the cement dries, it is very hard and restricts any relative movement between the pipe and hanger. This condition was not accounted for in the original piping analysis, and it is unacceptable.
Safety Implications
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This condition jeopardizes the overall qualification (seismic,
- thermal, etc.) of the piping on which the cement is used. Thermal facigue or a seismic event could have led to overstressing of this safety-related piping and could have thereby adversely affected the safety of the plant.
Corrective Action The hea't transfer cement will be removed from all areas which restrict specified capabilities for pipe movement. To alleviate the problem, TVA will revise the support design to accommodate the heat tracing and cement or will provide a bridge to carry the heat tracing and cement over or around the supports such that the specified movement capabilities are unaffected. Installation of the appropriate fix will be completed before fuel loading in unit 2.
TVA will implement procedures to ensure that our system designers have given proper consideration to heat tracing, cement, and insulation in their design. These procedures will be effected on or before March 13, 1981.
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