ML19341C418
| ML19341C418 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 02/13/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19341C415 | List: |
| References | |
| NUDOCS 8103030387 | |
| Download: ML19341C418 (2) | |
Text
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SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATIDH RELATED TO Af'ENDMENT NO. 3 TO FACILITY OPERATING LICENSE DPR-77 TENNESSEE VALLEY AUTHORITY During pre-operational testing, vibration problems were encountered in the Residual Heat Removal heat exchangers - the tubes tended to vibrate resulting in the tube wear. Other heat exchangers were examined and similar problems were encountered.
Component Cooling Water System (CCWS) heat exchangers A and B were modified by staking the tubes. However, modifications to CCWS heat exchanger C could not he completed without a change to Technical Specifi-cation 3.7.4.1.
With CCWS heat exchanger C out-of-service, a redundant heat exchanger would not be available to Unit 1 during operation.
In order to provide a redundant and qualified CCWS water supply to the heat exchanger, the licensee proposed to substitute the CCWS heat exchanger C, which acts as " standby" for CCWS beat exchanger A, with CCWS heat exchanger B and tying the ERCW header 18 to ERCW header 2A. The licensee requested that this modified arrangement be allowed for a period of eight weeks while performino modifications to CCW3 heat exchanger C.
With CCWS heat exchanger C temporarily out of service. heat exchanger A and heat exchanger B are available for Unit 1 operation and thus all safety requirements are met. Sufficient isolation capability exists for heat exchanger A to be isolated from ERCW header 18 in the event that train A power is lost.
Upon loss of train B power, a train A valve automatically closes to isolate ERCW header 2A from ERCW header 10.
We have reviewed the proposed temporary (eight weeks) ERCW supply header modifi-cation and conclude that the proposed mcdification does not violate the require-ments of General Design Criteria 44 of Appendix A to 10 CFR Part 50 or the position of Regulatory Guide 1.29, " Seismic Design Qualification," and is, therefore, acceptable.
Environmental Consideration We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4),
that an environmental impact statement or negative declaration and environmen-tal impact appraisal need not be prepared in connection with tM issuance of this amendment.
81030303 $ 7
. Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be con-ducted in complicance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Date:
February 1 1 1961
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