ML20092H081
| ML20092H081 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/15/1995 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20092H076 | List: |
| References | |
| NUDOCS 9509200251 | |
| Download: ML20092H081 (4) | |
Text
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UNITED STATES l
,3 NUCLEAR REGULATORY COMMISSION I
WASHINGTON, DN. 20885
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SAFETY EVALUATION BY THE OFFICE OF HUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 911 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 201 TO FACILITY OPERATING LICENSE NO. DPR '
TENNESSEE VALLEY AUTHORITY SE000YAH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328
1.0 INTRODUCTION
By letter dated August 7, 1995, Tennessee Valley Authority (TVA) requested changes to the Sequoyah Nuclear Plant (SQN) Units 1 and 2 Technical Specifications (TS) to revise the numerical value for the time constant 7 4
found in the overtemperature delta temperature (OTAT) and overpower delta temperature (0 PAT) trip equations of TS Table 2.2-1.
The 7 value would be 4
changed from 12 seconds to 5 seconds.
In addition, the equality signs for the 7 and K constant numerical values would be changed to either a "less than or equal to" or a " greater than or equal to" function, as applicable.
This application superseded a similar TS amendment that was proposed by letter dated April 6,.1095, to move these constants to the Core Operating Limits Report.
SQN has experienced OPAT turbine runback alarms on individual channels resulting in partial runback signals. These occurrences could result in turbine runbacks or reactor trips during functional testing at power. The proposed changes to the 7 constant numerical values result from a reanalysis 4
to provide additional margin to the trip setpoints and minimize the potential for turbine runback and reactor trip signals.
In the interim, SQN Unit 2 is presently operating at a maximum power of 99.5 percent of rated thermal power i
in order to reduce the potential for inadvertent turbine runback and reactor
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trip signals because of the spurious OPAT channel actuations.
j 2.0 EVALUATION The SQN safety analyses that rely on the OPAT and OTAT trips for primary i
protection are the uacontrolled rod cluster assembly bank (RCCA) withdrawal at power, loss of external load and/or turbine trip, uncontrolled boron dilution, accidental depressurization of the reactor coolant system, steamline break i
with coincident rod withdrawal at power, and steamline break mass / energy 4
outside containment. These transients were reanalyzed or evaluated.by Westinghouse Electric Corporation (W) with the proposed changes and found to' adhere.to all of the safety analysis acceptance criteria described in the t
plant's Final Safety Analysis Report (FSAR).
Therefore, the staff concludes l-that the proposed revision of the 7 constant numerical value is acceptable.
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.The revision of the equality signs for the constant numerical values of the j
OTAT and OPAT equations will provide the flexibility to set these values more l
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a 4 conservatively than the limits utilized in the safety analysis.
These changes, which are consistent with the M improved Standard TS, NUREG-1431, do not change these functions. Therefore, the staff finds the proposed changes-to the equality signs acceptable.
Based on the review described above, the staff finds the proposed modifications to the SQN Units 1 and 2 TS to revise the OTAT and OPAT equation constant numerical value 7 from 12 seconds to 5 seconds, and the change of 4
the equality signs for the 7 and K constant numerical values to either a "less than or equal to" or a " greater than or equal to" function, acceptable.
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3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The' amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined 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 the amendment involves no significant hazards consideration, and there has been no public comment on such finding (60.FR 42187). 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 or environmental assessment need be prepared in connection with the issuance of the amendment.
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5.0 CONCLUSION
The Commission 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 amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
Laurence Kopp Dated:
September 15, 1995 i
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i Mr. Oliver D. Kingsleyc Jr.
Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT cc:
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Mr. O. J. Zeringue, Sr. Vice President Nuclear Operations TVA Representative Tennessee Valley Authority Tennessee Valley Authority 3B Lookout Place 11921 Rockville Pike 1101 Market Street Suite 402 Rockville, MD 20852 Chattanooga, TN 37402-2801 Dr. Mark 0. Medford, Vice President Regional Administrator Engineering & Technical Services U.S. Nuclear Regulatory Commission Tennessee Valley Authority Region 11 3B Lookout Place 101 Marietta Street, NW., Suite 2900 1101 Market Street Atlanta, GA 30323 Chattanooga, TN 37402-2801 Mr. William E. Holland Mr. D. E. Nunn, Vice President Senior Resident Inspector New Plant Completion Sequoyah Nuclear Plant Tennessee Valley Authority U.S. Nuclear Regulatory Commission 3B Lookout Place 2600 Igou Ferry Road 1101 Market Street Soddy Daisy, TN 37379 Chattanooga, TN 37402-2801 Mr. Michael H. Mobley, Director Mr. R. J. Adney, Site Vice President Division of Radiological Health Sequoyah Nuclear Plant 3rd Floor, L and C Annex Tennessee Valley Authority 401 Church Street P.O. Box 2000 Nashville, TN 37243-1532 Soddy Daisy, TN 37379 County Judge General Counsel Hamilton County Courthouse Tennessee Valley Authority Chattanooga, TN 37402-2801 ET 11H 400 West Summit Hill Drive Knoxville, TN 37902 Mr. P. P. Carter, Manager Corporate Licensing Tennessee Valley Authority 4G Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Ralph H. Shell Site Licensing Manager Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 '
Soddy Daisy, TN 37379
AMENDMENT NO. 211 FOR SEQUOYAH UNIT NO.1 - DOCKET NO. 50-327 and AMENDMENT NO. 201 FOR SEQUOYAH UNIT NO. 2 - DOCKET NO. 50-328 DATED: September 15, 1995 DISTRIBUTION W/ ENCLOSURE
' Docket-Files:
PUBLIC SQN Reading File S. Varga 0-14-E-4 G. Hill T-5-C-3(2 per docket)
C. Grimes 0-Il-E-22 L. Kopp ACRS(4)
E. Merschoff RII H. Lesser RII
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