ML20106D710
| ML20106D710 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/05/1992 |
| From: | Joshua Wilson TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-R00419, TAC-R00420, TAC-R419, TAC-R420, NUDOCS 9210130301 | |
| Download: ML20106D710 (3) | |
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) l. //dNOh w e ne ww o - aur o.aw n e October 5, 1992 U.S. Nuclear Regulatory Commission AT1N:
Document Control Desk.
Washington, D.C. 20555 Gentlement
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In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQboYAll NUCLEAR PLANT (SQN) - SEISMIC QUALIFICATION OF CABLE TRAYS AND CONDUlT (PHASE II, DESIGN BASELINE AND VERIFICATION, TAC NOS. R00419/R00420)
References:
1.
TVA letter to NRC dated March 26, 1991 2.
NRC letter to-TVA dated January 18, 1991 " Seismic Qualification of Cable Trays and Conduit (Phase II.-
~ Design Baseline and Verification. TAC Nos. R00419/R00420)
- Sequoyah Nuclear Plant Units 1 and 2" The purpose of this letter is to confirm TVA's telephone conference on September 3, 1992, with NRC in which TVA,covided additional information to what was supplied in Reference 1.
Both of these submittels fully respond to the information requested in Reference 2.
In that conversation, SQN stated that we would no longer be using ductility factors in spectral reductions as in the current design of cable trays.
Although TVA believes our current methods are acceptable, we agreed to
-the more conservative inelastic acismic_ analysis approach.
The U. dated Final Safety ~ Analysis Report (UFSAR) was reviewed and.found i
to ne consistent with the present-Watts Bar Nuclear Plant (WBN) UFSAR.
Based upon this, a revision to the SQN UFSAR will not be required. SQN will no longer allow the use of ductility' factors for spectral reduction in the design of cable trays. Design criteria SQN-DC,V-1.3.4 has been revised to delete the use of ductility factors for_ spectral reduction.
Additionally, SQN will be reevaluating the safety-related cable trays L
using ' this more conservative WBN criteria. - If any modifications tre p
required, they will be designed and implemented by the end of each unit's-p Cycle 7 refueling outage.
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'U.S. Nucicar Regulatory Commission Page 2 i
October 5, 1992 A summary statement of the commitments is contained in the enclosure.
Please direct questions concerning this issue to W. C. Ludwig at (615) 843-7460.
Sincerely, h
.d k JI L. Wilson Enclosure cc (Enclosure):
Mr. D. E. LaBarge, Project Mar.ager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 NRC Resident Innpector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 L
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ENCLOSURE List of Commitments 1.
SQN will reevaluate s.afety-related cable trays for Uni.t 1 and redesign and modify any cable trays if required by the end of the Unit 1 Cycle 7 refueling outage.
2.
SQN will reevaluate safety-related cable trays for Unit 2 and common, and redesign and modify any cable trays if required by the end of the Unit 2 Cycle 7 refueling outage.
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