ML20012E077
| ML20012E077 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/19/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20012E076 | List: |
| References | |
| NUDOCS 9003300037 | |
| Download: ML20012E077 (3) | |
Text
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ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 132TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO.119 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY-
_SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
In its letter dated January 5,1990, the Tennessee Valley Authority (TVA) requested a change to Action Statement "a" of the Limiting Condition for Operation (LCO) 3.8.1.1, Alternating Current (AC) Sources, Operating), of Sequoyah Nuclear Plant,. Units 1 and 2. Technical Specifications (TSs. The proposed change is to replace " diesel generator set" by " diesel generator set (s) 1A-A and/or 2A-A or 1B-B and/or 2B-B" to allow the units to continue operating for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, before shutting down, with only one train of diesel generator sets inoperable.
A diesel generator set is diesel generator 1A-A, 2A-A, 1B-B or 2B-B.
In the letter dated January 5,1990, TVA also requested that the staff review this TS application on an exigent basis in accordance with 10 CFR 50.91(a)(6).
This was requested to allow the work on the Unit 1 essential raw cooling water (ERCW) system strainers to begin es scheduled in January 1990.
The staff responded to this request in its letter dated January 18, 1990.- In that letter, the staff stated that Action Statement "d" allowed TVA to have one L
train of. diesel generator sets (i.e., IA-A and/or 2A-A or IB-B and/or 28-B) inoperable for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before the units must begin shuttirg down.
Because Action Statement "a" is confusing regarding the loss of a single train of diesel. generators, the staff stated that it would review TVA's application i
dated. January 5, 1990.
Because Action Statement "d" allowed TVA to have one diesel generator train inoperable for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before the units must begin i
shutting down, the staff evaluated tMs application _on a non-exigency basis.
1 2.0 EVALUATION In its application, TVA stated that the Action Statements "a" and "d" of LC0 3.8.1.1 are inconsistent in that Action "a" allows continued operation for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with a single diesel generator set inoperable, whereas Action "d" allows operation to continue for the same period of time with two diesel generator sets inoperable provided both diesel generator sets are on the same l
train (i.e., IA-A and 2A-A or IB-B and 2B-B).
This fact was the basis for the staff's letter dated January 18, 1990 that TVA could begin work of the Unit 1 ERCW strainers before the proposed TS changes in the application dated January 5, 1990 were approved.
9003300037 900319
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-! L TVA stated that the requested change to Action Statement "a" of LCO 3.8.1.1 provides consistency within the LC0 as well as consistency with similar LCOs
.that have actions written with regard to " equipment train" availability.
TVA also stated that the requirements of General Design Criterion 17 of Appendix A to 10 CFR 50, which specify the minimum independent and redundant AC power sources, continue to be met with the proposed change to Action Statement "a."
The requirements in the TSs on the operability of the AC power sources during power operation ensures that sufficient power will be available to supply the safety-related equipment required for the safe shutdown of the facility and the mitigation and control of accident conditions within the facility.
To meet single failure criteria the safety-related equipment including the diesel generators are nonnally organized into two 100% separate trains.
The proposed TS change will allow the units to continue operating for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before shutting down as long as only one train of diesel generator sets is inoperable.
If two trains are inoperable. Action Statement "d" requires one train to be made operable within two hours or have the units in Hot Standby within the next six hours and in the Cold Shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Action Statement "d" is not being revised by the proposed TS changes.
The proposed TS changes are consistent with (1) requirements in the NRC Stand-ard Technical Specifications for Westinghouse Pressurized Water Reactors (STSWPWR), NUREG-0452, Revision 4A, September 1987 and (2) similar requirements in the TSs for one train of safety-related equipment being inoperable, as for example the ERCW system which is the ultimate heat sink for the units.
In addition, as stated above, Action Statement "d" allows continued operation of the units for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with only one train of diesel generator sets inoperable.
The problem is that Action Statement "a" is confusing about the situation for one train of diesel generator sets being inoperable.
Therefore, based on the above, the staff concludes that the proposed TS changes in the application dated January 5, 1990 are acceptable. Action Statement "a" will clearly state that with only one train of diesel generator sets being inoperable the units may continue operating for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
3.0 ENVIRONMENTAL _ CONSIDERATION These amendments involve a change to a requirement with respect to the instal-lation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendments involve 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 cumulatin occupational radiation expo-sure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public comment on such finding.
Accordingly, the amendments meet the eligibil-ity 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 environmen-tal assessment need be prepared in connection with the issuance of these amendments, t
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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 2447) on January 24, 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:
will not be endangered by operation in the proposed manner, and (2) public (1) there is reasonable assurance that the health and safety of the such activities will be conducted in compliance with the Commission's regulations, and 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: March-19, 1990 1
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