ML20002A495
| ML20002A495 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 08/18/1977 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20002A492 | List: |
| References | |
| NUDOCS 8011170365 | |
| Download: ML20002A495 (2) | |
Text
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NUCLEAR REGULATORY COMMISslON
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WASHING TON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION==
SUPPORTING AMENDMENT NO. 41 TO FACILITY OPERATING LICENSE NO. OPR
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YANKEE ATOMIC ELECTRIC COMPANY YANKEE NUCLEAR POWER STATION (YANKEE-ROWE)
-DOCKET NO. 50-29
_ Introduction By application dated July 5,1977, Yankee Atomic Electric Compar.y (the licensee) requested an amendment to its Facility Operating LLense No.
DPR-3 for the Yankee-Rowe reactor.
The amendment would modify the facility Technical Speef fications relating to shock suppressors (snubbers).
Discussion and Evaluation Yankee-Rowe has eight hydraulic shock suppressors (snubbers) located on the pressurizer relief lines. The purpose of those snubbers is to restrain pipe motion under dynamic loads as might ' occur during severe transients while allowing normal thermal movement of the pressurizer relief lines during startup and shutdown of the reacter.
Presently, the Technical Specifications include surveillance requirements in Section 3.4.7.9 " Shock Suppressors (Snubbers)" which were specifically developed for hydraulic snubbers.
issuance of Amendment No. 29 to DPR-3, dated JulyOur safety evaluation supp 22, 1976, discusses past experience with degradation of seal naterials in hydraulic snubbers, and presents an evaluation of acceptability of the present Technical Specifications with respect to providing additional assurance of satisfactory performance and reliability of hydraulic snubbers at Yankee-Rowe.
During the present outage for refueling with Core XIII the licensee proposes to replace the hydraulic snubbers with Pacific Scientific PSA-3 type mechanical snubbers.
Due to the desir;n (no sealing materials and no hydraulic actuating system) the mechanical sNbbers are more reliable since they are not subject to potential degradation of seal material, loss of fluid and other factors affecting functional perfonnances, as are the hydraulic snubbers.
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-2 To accoanodate the proposed changeover from hydraulic snubbers to mechanical snubbers at this time requires changes to the Te':hnical Specifications in Section 3.4.7.9 prior to startup of Yankee-Rowe with Core XIII.
Accordingly for these mechanical snubbers, the licensee has proposed in its July 5,1977, application, to delete the surveillance requirements that are solely applicable to hydraulic snubbers, and to include instead requirements for periodic visual inspections to verify proper snubber orientation and proper attachment of linkage connections to the piping and anchors. The limiting conditions for snubber operability and the surveillance frequency would remain unchanged.
We have concluded that the proposed change from hydraulic to mechanical snubbers and the associa'.ed acconnodating changes in the Technical Specifications, do not decrease the degree of confidence in the con-tinued successful performance of these snubbers and we therefore, find these changes to be 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 detennination, 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 state-ment or negative d2claration and environmental impact appraisal need not be prepared in cranection with the issuance of this amendment.
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 conducted in compliance 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:
August 18, 1977 l
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