ML19347D967

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Final Deficiency Rept Re Steel Containment Penetration Assembly,Initially Reported on 801219.No Mods Required Per Reanalysis
ML19347D967
Person / Time
Site: Sequoyah Tennessee Valley Authority icon.png
Issue date: 04/07/1981
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, SQRD-50-328-81, NUDOCS 8104140539
Download: ML19347D967 (1)


Text

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TENNE 35EE VALLEY AUTHCo '

c . - a sec n T nessc 27, 400 Chestnut Street Tower II April 7, 1981

?QRD-50-328/81-09 Mr. James . O'Reilly, Director Office of I tepeation and Enforcement U.S. Nuclear % gulatory Cosmiission Region II - Sui 3100 101 Marietta St t Atlanta, Georgia 303

Dear Mr. O'Reilly:

SEQUOYAH NUCLEAR PLANT UNIT 2 - STEEL CONTAINME;NT PENETRATION ASSEMBLY -

SQRD-50-328/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector F. Cantrell en December 19, 1980, in accordance with 10 CFR $0.55(e) as NCR SQN CEB 8041.

An interim report was submitted on January 19, 1981.

Enclosed is our final mport.

If you have any questions, please get in touch with D. L. Lambert at FTS 857-2581.

Very truly yours, TENNESSEE VALLEY AIT!HORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosurw cc: Mr. Victor Stello, Director (Enclosure),v/

Office of Inspection and Enforcement l l U.S. Nuclear Regulatory Constissian washir.gton, DC 20555 30/7

.5 I(

i 0104140539 5-

,a k ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 STEEL CONTAINMENT PENETRATION ASSEMBLY SQRD-50-328/81-09 10CFR50.55(e)

FINAL REPORT Description of Deficiency The residual heat removal (RHR), main steam, and main feedwater pipes penetrate the steel containment vessel.(SCV) by means of a free-floating bellows penetration assembly. Maximum internal pressure inside the SCV after a loss-of-coolant accident (LOCA) is 12 lbs/in2 . The axial load due to high containment pressure on the effective area of the SCV penetration opening was not considered in the RHR, main steam, and main feedwater piping analysis.

Safety Implications The results of TVA's reanalysis of the affected piping revealed that no design modifications are required and that the present design configuration is adequate to carry all loads. Therefore, this conditions could not have adversely affected the safety of the plant.

Corrective Action TVA reanalyzed the affected piping in order to determine if the present design of the penetration assemblies and pipe rupture restraints was adequate to carry all loads. Resulting piping stresses and support design loads were evaluated and found to be acceptable. Therefore, no design modifications are mquired.

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