ML20004E704
| ML20004E704 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 05/06/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20004E703 | List: |
| References | |
| NUDOCS 8106150083 | |
| Download: ML20004E704 (2) | |
Text
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g O C'Cg tD UNITED STATES y,
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NUCLEAR REGULATORY COMMISS!ON o
WASHINGTON, D. C. 20$55 SAFET( EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 60 TO PROVISIONAL OPERATING LICENSE NO. D i
COMMONWEALTH EDISON COMPANY DRESDEN 2 DOCKET N0. 50-237_
1.0 INTRODUCTION
27, 1981, Commonwealth Edison Company (Ceco) informed By letter dated March NRC that they had reanalyzed the seismic design of safety related piping, at Dresden L' nit 2, in response to IE Bulletin 79-14. The reanalysis identi-fled piping locations where existing safety related hydraulic snubbers had to be removed to prevent the occurrence of stresses in excess of the original In addition, CECO also replaced the remaining hydraulic FSAR requirements.
snubbers located in inaccessible areas with mechanical snubbers.
Because the hydraulic snubbers were identified in the Technical Specifica-tions, CECO has proposed an amendment to the Technical Specifications which would reflect the removal of~ the hydraulic snubbers and the replacement of some of them by mechanical snubbe.rs.
2.0 DISCUSSION AND EVALUATION The CECO analyses completed in response to IE Bulletin 79-14, using as-built f
piping configurations, identified nine (9) piping locations where the stress l
CECO corrected was calculated to be in excess of the allowable stresses.
these overstress conditions by relocating and removing a number of hydraulic l
l shock suppressors that were contributing to the stresses on the piping.
We have reviewed Ceco's new snubber configurations and concur with their determination that they have acceptably eliminated the overstressed points The reconfigured piping stresses no
(
by reteving and relocating snubbers.
longer violate the allowable scress limits and are therefore acceptable l
l to the staff.
l In addition, CECO has replaced all remaining inaccessible hydraulic snubbers l
These mechanical snubbers on safety related piping with mechanical snubbers.
will proviae an equivale1t level of safety and restraint as was previously provided by the hydraulic sn'ubbers and their use is acceptable to the NRC l
staff.
8106150OD
Based on the. above, we conclude that the Technical Specifications should be changed to delete the hydraulic snubbers which have been replaced by mechanical snubbers and to add the mechanical snubbers to the list of
' snubbers required for Dresden 2 operation.
1 3.0 ENVIRONMENTA'L CONSIDERATION We have determined that the 'nendment 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 statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
A. '-
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that: (1) because the amendment does not involve a significant increhse in the pro-bability 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 Fy operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety af the public.
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Date:
May 6,1981 l
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