ML20065S203
| ML20065S203 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/10/1990 |
| From: | Donohew J Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20065S187 | List: |
| References | |
| NUDOCS 9012200144 | |
| Download: ML20065S203 (3) | |
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1 ENCLOSURE 2 SAFETY TVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMEN 0 MENT NO.136 TO FACILITY OPERATING LICENSE NO. OPR-79
, TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-328
1.0 INTRODUCTION
By letter dated May 21, 1990, as supplemented by the letter dated November 13, 1990, the Tennessee Valley Authority (TVA) proposed to modify the Sequoyah Nuclear-Plant, Unit 2,TechnicalSpecifications(TSs). The proposed changes would revise valve nomenclature in TS Table-3.6-2, Containment Isolated Valves. The nomenclature of nine sampling valves in the TS table would be changed from flow control valve (FCV) to flow solenoid valva (FSV). The maximum allowed valve closure times for these valves are not being changed. The Unit 2 valves 1
were changed in the recently completed Unit 2 Cycle 4 refueling outage. This is TVA Change Request 90-14 This application also included similar proposed changes for Table 3.6-2 of Unit 1 TSs. The Unit i valves were replaced in the Unit 1 Cycle 4 refueling outage. The. changes to the Unit 1 TSs were issued as Amendment 145 in the staff's letter dated September 20, 1990 In the supplementary letter dated November 13, 1990, TVA reduced the number of valves to be changed to FSVs from 14 to nine.
Five of the valves listed in the May 21, 1990 letter that were planned to be changed to FSVs will remain FCVs because these valves are-located in the Reactor Building annulus and can accommodate.a limit switch that is environmentally qualified. Therefore,
these five valves do not have to be changed to FSYs. The remaining nine valves to be changed are valves listed in the May 21,1990 letter. Therefore, this reduction in the number of valves to.be changed does not affect the substance of the proposed action and no significant hazards consideration finding pub -
lished in the Federal Register Notice (55 FR 26296) on June 27, 1990, and does not change the staff's initiaT determination of no-significant hazards consider-ation in that notice.
2.0 EVALUATION In its letters, TVA stated that nine air-operated FCVs were replaced at Unit 2 4
with FSVs because the FCVs have limited switches that are not environmentally qualifiable. The FSVs are totally enclosed and have reed switches internal to the valve, and are environmentally qualified. This replacement was t2 quired as part of TVA's commitment for complying with RG 1.97 (i.e., Condition 2.C.(24) of the Unit 1 Facility Operating License DPR-77 and License Condition 2.C.(14) oftheUnit2FacilityOperatingLicenseDPR-79).
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, The nine containment isolation valves are on sampling lines for the reactor coolant system (RCS), cold leg injection accumulator, and steam generator blowdown (SGBD). TVA stated that the change in valve nomenclature for these j
valves from FCV lo FsV does not affect the containment isolation function for these valves. TVA explained that closure times for the new FSVs was evaluated to ensure that these valves will meet the 5-and 10-second maximum isolation time requirements in TS Table 3.6-2.
The new FSVs are designed to close against a pressure drop of 2,485 pounds per square inch gauge with a temperature of 640 degrees fahrenheit.
These valves are compatible with the RCS and capable of closing against RCS pressure. With the exception of the four SGBD sampling valves, local leak-rate testing was conducted as a premodification test to determine the "as-found" leak-rate end again following installation of the new valve to determine the "as-left" leak rate, in accordance with Appendix J of 10 CFR 50.
This is done to demonstrate an acceptable leak-rate for containment integ ri ty, i
TVA explained that the SGBD sampling valves are a part of the steam generator secondary side piping and are located outside containment.
By design, the SGB0 piping employs the following two barriers to prevent fission product release from containment following a loss of coolant accident:
(1) the secondary side is a closed system inside containment and (2) SG water level provides a water seal.
These containment isolation barriers exempt the SGBD valves from the Appendix J leak-rate test program.
This is discussed in the Final Safety Analysis Report, Table 6.2.4-1, notes for Containment Penetrations X-14A, B, C, and D.
TVA has replaced nine containment isolation valves on sampling lines from FCVs to FSVs so that the new valves will meet the requirements in RG 1.97 TVA is proposing to change the valve nomenclature in Table 3.6-2 to reflect the fact that these valves are now FSVs.
Nothing else is being changed by the proposed changes. The existing requirements on the leak-rate testing and the maximum valve closure time of these valves are not being changed.
The existing requirements on containment integrity are also not being changed. The new valves are qualified for their function as containment isolation valves.
Based on this, the staff concludes that the proposed changes are acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff has determ6d that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement nor environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The Commission made a proposed determination that the amendment involves no significant hazards consideration which was published in the Federal Register (55 FR 26296) on June 27, 1990 and consulted with the State of Tennessee.
No public comments were received and the State of Tennessee did not have any comments.
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security nor to the health and safety of the public.
Principal Contributor:
J. Donohew Dated:
December 10, 1990
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