ML20083B874
| ML20083B874 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/03/1995 |
| From: | Shell R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TVA-SQN-TS-93, TVA-SQN-TS-93-0, NUDOCS 9505120256 | |
| Download: ML20083B874 (4) | |
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Hl4 Tenressee Valley Autrey,tf Post Othce Bos 2(XA 9xidy Day Terressee 37379 May 3,1995 TVA-SON-TS-93-09 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:
In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT (SON) - REVISED AMENDMENT IMPLEMENTATION DATE FOR TECHNICAL SPECIFICATION (TS)
CHANGE 93-09
References:
- 1. NRC letter to TVA dated October 17,1994, " Issuance of Amendments (TAC Nos. M90197 and M90198) (TS 93-09)"
- 2. TVA letter to NRC dated August 19,1994, "Sequoyah Nuclear ,
Plant (SON) - Revised Amendment implementation Date for Technical Specification (TS) Change 93-09 (TAC Nos. M87872 and M87873)"
By the Reference 1 letter, NRC issued License Amendment Nos.188 and 180 for SON Units 1 and 2, respectively. These amendments revised the required implementation date for the revised setpoints and time delays for the auxiliary feedwater loss-of-power and 6.9-kilovolt (kV) shutdown board loss-of-voltage and degraded-voltage instrumentation. The revised implementation date was requested by TVA in Reference 2. These amendments delayed the implementation of Amendments 182 and 174 until acceptable plant conditions and modification activities / procedures are established in 1995.
9505120256 950503 PDR 'ADOCK 05000327 P PDR g
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.- t Nuclear Regulatory Commission Page 2 May 3,1995 The purpose of this revised amendment implementation date request is to defer implementation of the revised loss-of-power instrumentation requirements, for SON Units 1 and 2, until the related plant modifications and TSs can be revised and executed. The exact timing will be dependent upon the development of a revised modification package and NRC approval of the resulting TS setpoints and timedelays.
TVA indicated in Reference 2 that additional evaluations would be performed for the modification activities prior to implementation. These evaluations resulted in the conclusion that the implementation of the proposed design change could involve a significant risk to nuclear safety. These risks were the result of placing various plant components in temporary configurations, performance of numerous wire manipulations, and the need to extend the diesel generator allowed outage time by a factor of four. TVA concluded that the implementation of this modification was not in the best interest of safety.
TVA is pursuing a new design that will allow use of the alternate feeder breaker to the 6.9-kV shutdown boards and implements the same level of voltage protection that was proposed in the original TS change request. The revised modification package is being developed with the implementation requirements being considered on the front end to ensure a design that can be reasonably achieved. The required revisions to the presently approved TS Amendments 182 and 174 are scheduled to be submitted to NRC in August 1995, to support the new design.
Therefore, TVA requests that the implementation requirements of SQN Amendments 182 and 174 for Units 1 and 2, respectively, be amended as follows:
This licenso amendment is effective as of its date of issuance, to be implemented with the related plant modifications.
TVA has reviewed this request against the previous submittals. No changes to the TSs themselves are proposed at this time. The existing degraded-voltage and loss-of-voltage instrumentation at SON provides acceptable voltage protection to ensure sufficient voltage to operate required safety-related loads for postulated accidents. Administrative controls to prever.t the use of the alternate 6.9-kV shutdown board feeder breakers will remain in place until the modifications are complete. Therefore, TVA has determined that the significant hazards evaluation remains valid and that the proposed changes do not constitute a significant hazard.
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'I Nuclear Regulatory Commission ll
- Page 3 l May 3,~ 1995 l l
l There are no comittments contained in this submittal. i i
Please direct questions concerning this issue to Keith Weller at (615) 843-7527. ,
Sincerely, kulk.
R. H. Shell !
Manager SON Site Licensing l
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U.S. Nuclear Regulatory Commission Page 4 May 3,1995 cc: Mr. D. E. LaBarge, Project Manager Nuclear Regulatory Commission One White Flint, North ,
11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Michael H. Mobley, Director Division of Radiological Health 3rd Floor L & C Annex 401 Church Street -
Nashville, Tennessee 37243-1532 l NRC Resident inspector i Sequoyah Nuclear Plant l 2600 Igou Ferry Road l Soddy-Daisy, Tennessee 37379-3624 )
Regional Administrator !
U.S. Nuclear Regulatory Commission Region ll j 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-2711