ML20038C328
| ML20038C328 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 11/27/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20038C326 | List: |
| References | |
| TAC-47351, TAC-47352, TAC-47353, NUDOCS 8112100434 | |
| Download: ML20038C328 (4) | |
Text
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UNITED STATES y
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING ABIENDt1ENT NO. 45 TO FACILITY OPERATIllG LICENSE fl0. DPR-72 FLORIDA POWER CORPORATION, ET AL CRYSTAL RIVER UNIT NO. 3 NUCLEAR GENERATING PLANT DOCKET NO. 50-302 Introduction By a'pplications dated Noverber 17, 1981, Florida Power Corporation (FPC or the licensee) requested changes to the Technical Specifications (TSs) of Facility Operating License No. DPR-72 for operation of the Crystal River Unit No. 3 Nuclear Generating Plant.
These changes would delete four hydraulic shock suppressors (snubbers) from TS Table 3.7-3, " Safety Related Hydraulic Snubbers",
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and would add a definition of " operable" for hydraulic snubbers in locations outside the. reactor building during Cycle 4 operation.
Discussion FPC is completing a refueling and maintenance outage at CR-3.
Part of the maintenance is visual inspection and functional testing of hydraulic snubbers.
During the snubber inspection, FPC discovered cracks in many of the aluminum reducer bushings that connect the fluid line from a valve body to a snubber cylinder. Because of this, FPC has removed and rebuilt all hydraulic snubbers in the CR-3 reactor building except for four snubbers as discussed below.
Except for these four snubbers, all of the aluminum bushings for snubbers in the reactor building have been replaced with stainless steel and the snubbers functionally tested before installation.
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CR-3 Snubbers outside the reactor building are also being rebuilt with aluminum 1
bushings replaced and functional tests performed before installation.
No cracked bushings have been discovered on the snubbers outside the reactor building to date, however, with a 100% visual inspection. The schedule for rebuilding these snubbers is evaluated below.
Evaluation Deletion of Four Snubbers from Surveillance Requirements l
FPC has removed and rebuilt all hydraulic snubbers in the CR-3 reactor building during the current refueling outage except for four snubbers located in the letdown cooler roo.n where a strong radiation field exists.
To maintain personnel radiation exposure as low as reasonably achievable, FPC decided to leave these four snubbers in place.
For these four snubbers, FPC has made stress analyses that assume a fully locked-up or a totally loosened snubber for the thermal cycling or Design Basis Earthquake (DBE) loadings, respectively.
These analyses of the two limiting cases indicate that design limits will not be violated and functional integrity of the letdown cooler will be maintained during those loading events.
Therefore, improper performance of these four hydraulic snubbers will not affect the operability of the letdown cooler.
The deletion of these four snubbers, MUH-86, MUH-87, MUH-88, and MUH-89, from Table 3.7-3 of the CR-3 TSs is therefore acceptable.
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Operability of Snubbers Outside Reactor Building As discussed above, FPC has removed and rebuilt hydraulic snubbers inside the reactor building.
Since the same generic degradation nay also effect the snubbers outsidu the reactor building, FPC has decided to recondition all of these J
snubbers during the Cycle 4 operations period. To assure safe operation of CR-3 during this process, FPC has evaluated each snubber location outside the
CR-3 reactor building to determine which snubbers could cause an unacceptable stress if they locked-up during thermal cycling of the plant. These snubbers will be rebuilt as required and determined to be operable prior to return of the reactor to power operations following this refueling. All of the remaining 4
snubbers outside containment will be rebuilt as expeditiously as possible during Cycle 4 as parts becore available. To allow this flexibility for rebuilding the snubbers outside the reactor bui;'ing, FPC has proposed the following footnote to Paragraph 4.7.9.1 of the TSs:
"For the duration of Cycle 4, hydraulic snubbers in locations outside the reactor building shall be considered 0FERABLE if analysis has shown that unacceptable stresses will not result from snubber lock-up during operation."
The proposed change is acceptable because these snubbers will be determined operable only if they have been rebuilt or if satisfactory results are ob-tained from stress analysis.
l 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 4
result in any significant environmental impact. Having made this determination, we have further concluded that the amendment involves an action which is in-significant from the standpoint of environmental impact and, pursuant to 10 i
CFR 851.5(d)(4), that an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
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CR-3 Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the anendment 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 regulaticas 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.
Dated: November 27, 1981
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