ML19344B522
| ML19344B522 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/16/1980 |
| 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-SWP-801, NUDOCS 8010210405 | |
| Download: ML19344B522 (2) | |
Text
53-327 j.
400 Chectnut Street Tct;er II October 16, 1980 Mr. dames P.
'Railly, Director
' Office of Insp. tien and Enforcement U.S. Nuclear Re:;;u -tery Commission Region II - Suite 3 0-101 Haraetta Street Atlanta, Cecrgia 3030;,
Lear Mr. O'Reilly:
SEQUOYAli NUCLEAR PLANT UNIT 2 - EVALUATION OF SE!; SING lit.E COUUEC* IONS IO PLCCESS PIPI:iG NCR SQf4 SWP'8010 - FINAL REPORT The cubject deficiency 'ms initially reported to IiRC-0II Incpector C.- R. licFarland on July 9,1980, in accordance tiith 10 CFR 50.53(c).
. An interim report ma cubmitted en August 7,1S60. Enclosed is cur final report.
If you have any questions, please get in touch with D. L. Lc=bert at FTS 357-2581.
Very truly yours, TEENESSEE VALLEY AUThCRITY L. M. Mills, Manager Nucicar Regulation en:: Screty Enclosure ea:
Mr. Victor Stello, Director (Enclosure)
Office.of Inspection snd Er.forcement U.S. Nuclear. Regulatory Cceniccien Washir4 ten, OC 20555
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ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 EVALUATION OF SENSING LINE CONNECTIONS TO PROCESS PIPE NCR SQN SWP 8010 10 CFR 50.55(e)
FINAL REPORT Descriotion of Deficiency During a review of the seismic analyses of several safety-related piping systems, it was found that all the instrument sensing lines taken off 2-1/2 inch diameter or under process lines were not included in the process line analysis.. The sensing lines were assumed to be flexible, light weight tubing lines but were actually rigid, relatively heavy piping lines. The stress imposed on the process piping due to less flexible sensing lines and the ~ inertial effects of the increased weight of the sensing line pipes and connections were not included in the seismic analysis; therefore, supporting hardware may prove to be, inadequate to carry the design loads.
Safety Implications This nonconformance. pertains to the main system piping of several safety-related systems which are two inches in diameter or smaller. Some of these systems, such as the component cooling system, are required to operate during all phases of plant operation and shutdown. Loads on.the process piping system caused by heavier, more rigid sending lines could cause such systems as the component cooling system to fail. This could adversely 4
affect the plant's ability to go to cold shutdown and, therefore, could result in degradation in the safety or operation of the plant.
Corrective Action 4
TVA has reanalyzed the affected process piping and has found that no hardware changes will have to be made 'to carry the additional loads. The component cooling system and the chemical valume control system were the only two systems involved. TVA has notif'.ed ~ the appropriate design groups to ' ensure that there are no recurrences. TVA has found no generic implicaticns at other plants at this time.