ML20072J093
| ML20072J093 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 08/19/1994 |
| From: | Shell R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M87872, NUDOCS 9408260194 | |
| Download: ML20072J093 (3) | |
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d August 19, 1994 TVA-S ON-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
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQUOYAH NUCLEAR PLANT (SON) - REVISED AMENDMENT IMPLEMENTATION DATE FOR TECHNICAL SPECIFICATION (TS) CHANGE 93-09 (TAC NOS. M87872 AND M87873)
References:
1.
TVA letter to NRC dated March 29,1994, "Sequoyah Nuclear Plant (SON) - Supplemental Information for Technical Specification (TS)
Change Request 93-09" 2.
NRC letter to TVA dated May 24,1994, " Issuance of Amendments (TAC Nos. M87872 and M87873)(TS 93-09)"
3.
TVA letter to NRC dated October 1,1993, "Sequoyah Nuclear Plant (SON) - Technical Specification (TS) Change 93-09,' Revised Setpoints and Time Delays for the Loss-of-Power Instrumentation'"
By the Reference 2 letter, NRC issued License Amendment Nos.182 and 174 for SON Units 1 and 2, respectively. These amendments revise the setpoints and time delays for the auxiliary fem' water loss-of-power and 6.9 kilovolt (kV) shutdown board lons-of-voltage ar, ug<aded-voltage instrumentation. These changes were requested by TVA in Referer me-i and 3. These amendments were effective as of the date of issuance and were tu be imple nented upon completion of the related plant modifications during the Unit 2 Cycle 6 refueling outage. The purpose of this revised
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Nuclear Regulatory Commission Page 2 i
August 19, 1994 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 are being executed. T he present plans are to implement the plant modifications within fiscal year 1995. The exact timing will be dependent upon preparing appropriate staging and detailed evaluations of the modification activities as well as processing regulatory approvals that may be required.
During the present Unit 2 Cycle 6 refueling outage, the implementation of the loss-of-voltage modifications was to bo accomplished in two stages to provide completion durations within the TS 3.8.1.1 action limits associated with Unit 1 that is in power operation. The additional number of temporary wire terminations and jumpers for the staged process were determined to increase the risk of exceeding the TS action limit of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. These' concerns, along with additional testing and partial modification configurations for the operators to contend'with, caused TVA to reevaluate the best conditions for implementation of these changes. This evaluation resulted in a decision to move this modification outside the refueling outage and into -
the period where both units would be in power operation.
Performance of this modification during power operation will not initiate reactor trips.
There is a potential for inadvertent diesel generator start signals or 6.9 kV shutdnwn l
board load shedding that would be considered an engineered safety feature actuation.
Overall, the modification performance during power operation is considered acceptable because of the minimization of coordinated activities associated with a refueling outage. The additional time for imp lementation will also provide better planning M the staged modification approach to meet TS action times or ample time to request a one-l time TS change, should the optimum modification plan require more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Therefore, TVA requests that the implementation requirements of SON Amendments 182 and.174 for Units 1 and 2, respectively, be amended as follows:
l This license amendment is effective as of its date of issuance, to be l
implemented with the related plant modifications.
l TVA has reviewed this request against the previous submittals. No changes to the TSs themselves are proposed herein. The existing degraded-voltage and loss-of-voltage instrumentation at SGN provides acceptable voltage protection to ensure sufficient voltage to operate required safety-related loads for postulated accidents.
Administrative controls to prevent 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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U.S. Nuclear Regulatory Commission l
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August 19, 1994 There are no comittments contained in this submittal.
Please direct questions concerning this issue to Keith Weller at (615) 843-7527.
Sincerely, pY, R. H. Shell l
Manager SON Site Licensing Sworn to and suba ribed before me i
this day of
>_ul-1994
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Notary Public My Commission Expires 8-Y-9(o 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 l
Division of Radiological Health 3rd Floor L & C Annex 401 Church Street Nashville, Tennessee 37243-1532 NRC Resident inspector l
Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tenna,see 37379-3624 Regional Administrator U.S. Nuclear Regulatory Commission Region ll 101 Marietta Street, NW, Suite 2900 I
Atlanta, Georgia 3'J323-2711