ML20147E901

Provides Supplemental Response to Integrated Design Insp Item D4.2-1,per Insp Repts 50-327/87-48 & 50-328/87-48

ML20147E901
Person / Time
Site:	Sequoyah
Issue date:	03/02/1988
From:	Michael Ray TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20147E908	List: ML20147E901 ML20147F058
References
NUDOCS 8803070182
Download: ML20147E901 (3)

Text

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g A l' TENNESSEE VALLEY AUTHORITY.

CHATTANOOGA.' TENNESSEE 37401 SN 105B Lookout Place MAR 21988 U.S. Nuclear Regulatory Commission.

ATTN:. Document' Control' Desk Washington, D.C. 20555

. Centlemen:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - INTEGRATED DESIGN INSPECTION (IDI) - NRC INSPECTION REPORT 50-327/87-48 AND 50-328/87-48

- Enclosed is TVA's supplemental response to IDI item D4.2-1. It is our understanding that the revised response provided herein completes TVA's

' actions on this item for unit 2 restart.

If you have any questions, please telephone D. L. Williams at (615) 632-7170.

- Very truly yours, TENNESSEE VALLEY AUTHORITY

\M M. J. R y, Deputy D rector

! Nuclear icensing and Regulatory Affairs

! Enclosures I' ' ec: See page 2 l

8803070182 Og%$27 PDR ADOCK O PDR 3

M1 I I An Equal Opportunity Employer

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U.S.' Nuclear Regulatory Commission h blI N Enclosure cc (Enclosure):-

Mr. K.,P. Barr, Acting Assistant Director Lfor' Inspection Programs TVA Projects Division ,

U.S. Nuclear' Regulatory Commission Region II- ~

101 Marietta Street, NW, Sulte 2900 Atlanta,-Oeorgia 30323 Mr. G.'G. Zech, Assistant Director i

. for Projects TVA Projects Division U.S. Nuclear Regulatory Commission One White Flint, North

.11555 Rockville Pike Rockville, Maryland 20852 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 i-t

ENCLOSURE SEQUOYAH NUCLEAR PLANT SUPPLEMENTAL RESPONSE TO IDI' ITEM D4.2-1 ITEM NUMBER: D4.2-1 TITLE: E3CW Access cell Design

SUMMARY

OF ITEM:

ERCW access cells were analyzed as a monolitic structure. However, the concrete shrinks away resulting in its behavior as individual cells.

This item documents the concern that the original analysis of the ERCW access cells may be based upon an unconservative assumption. The seismic analysis may need to consider each cell as acting independently.

CLASSIFICATION: No Deficiency SUPPLEMENTAL RESPONSE:

During the NRC inspection conducted February 15 through 19, 1988, the NRC reviewer who had originally indicated a coucern about the ERCW. cell seismic analysis raised another concern about the concrete modulus used in the original analysis by Bechtel. To resolve this additional concern, Bechtel performed further analyses with a modulus agreed to by the NRC.

The attached seismic analysis report presents the results of analyses performed to demonstrate the upper bound deflection and lower bound stability of the ERCW access cells. These cells have been investigated as freestanding bodies subjected to a seismic base excitation. These analyses demonstrate the

, stability of the cells and indicate that even though the cells are postulated to act individually, the maximum deflection at the elevation of the ERCW pipes is 0.89 leches. The ERCW pipes are surrounded by three inches of crushable material, i.nd this calculated deflection is well within this three-inch maximLM.

Therefore, there is no impact on the safety of the ERCW piping system because of excessive deflection of the access ec11s. Calculations supporting these analyses are contained in CEB calculation B41 880201 008.

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