ML18052A813
| ML18052A813 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/19/1986 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML18052A812 | List: |
| References | |
| NUDOCS 8612240027 | |
| Download: ML18052A813 (2) | |
Text
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ATTACHMENT
- consumers Power Company Palisades Plant Docket 50-255 SPENT FUEL STORAGE.MODIFICATION SAFETY ANALYSIS REPORT AMENDED PAGE 4-11 December 19, 1986
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4.6.4 FUEL ASSEMBLY DROP ACCIDENT ANALYSIS In the unlikely event of dropping a fuel assembly, accidental deformation of the rack will not cause the criticality acceptance criterion to be violated.
For the an~lysis of a dropped fuel assembly, three accident conditions were postulated.
The first accident condition conservatively assumed that the weight of a fuel assembly and its handling tool of 1,500 pounds impacted the top of the fuel rack from a drop height of 3 feet.
Calculations showed that the impact energy is absorbed by the dropped fuel assembly, the cells and rack base plate assembly.
Under these faulted conditions, credit was taken for dissolved boron in the water, and the criticality acceptance criterion is not violated.
The second accident condition was an inclined drop on top of the rack.
Results were the same as for the first condition.
The third accident condition assumed that the dropped assembly (1,500 lbs) fell straight through an empty cell and impacted the rack base plate from a drop height of 183 inches.
The results of this analysis showed that the impact energy is absorbed by the fuel assembly and the rack base plate, the criticality acceptance criterion is not violated, and the spent fuel pool liner is not perforated.
Criticality calculations show that keff ~ 0.95 and the acceptance criterion is not violated.
4.6.5 FUEL RACK SLIDING AND OVERTURNING ANALYSIS I
Consistent with the criteria of the NRC "OT Position for Review and Acceptance of Spent Fuel Storage and Handling Applications," the racks were evaluated I
for overturning and sliding displacement due to earthquake conditions under the various conditions of full, partially filled, and empty fuel assembly loadings.
The nonlinear model described in Section 4.5 was used in this evaluation to I
accoun~ for fuel-to-rack impact loading, hydrodynamic forces, and the nonlinearity of sliding friction interfaces.
The horizontaT resistive force at the interface between the rack module and pool floor is produced by friction.
A range of friction coefficients (µ = 0.2 and 0.8) were used in this analysis.
A low coefficient of friction (µ = 0.2) produces maximum rack base horizontal displacement or sliding while a high value (µ = 0.8) produces maximtim rack horizontal overturning force.
The fuel rack nonlinear time-history analysis shows that the fuel rack slides a minimal distance.
This distance -combined with the rack structural-
- deflection and thermal growth is less than rack-t_o-rack or rack-to-wall clearances.
Thus, impact between adjacent rack modules or between a rack module and the pool is prevented.
The factor of safety against overturning was well within the values permitted by Section 3.8.5.II.5 of the Standard Review Plan.
PALSFP-4-NL04 4-11 Rev 1 As Revised 10/16/86 As Amended 12/19/86 I
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