ML19294A561
| ML19294A561 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 12/06/1978 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Burstein S WISCONSIN ELECTRIC POWER CO. |
| References | |
| NUDOCS 7812210320 | |
| Download: ML19294A561 (5) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION 3
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WASHINGTON, D. C. 20555 k idh[jf December 6,1978 v
y Docket Nos. 50-266 and 50-301 Mr. Sol Burstein, Executive Vice President Wisconsin Electric Power Co pany 231 West Michigan Street Milwaukee, Wisconsin 53201
Dear Mr. Burstein:
In conducting our review of your March 21, 1978 request (as supplemented and amended) relating to an expansion of spent fuel storage capacity at the Point Beach Nuclear Plant Unit No. I and 2, we have detennined that we will need the additional infor-mation identified in the enclosure to continue the review.
In order for us to maintain our review schedule, your response is requested as soon as possible. Three signed originals and forty copies are required.
Please contact us if you have any questions concerning this request.
Sincerely,Y I
- yudads A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors
Enclosure:
Request for Additional Information cc w/ enclosure:
See next page r'
f-71/.z2/ osa
Wisconsin Electric Power Company 2-December 6, 1978 cc:
Mr. Bruce Churchill, Esquire Mary Lou Jacobi Shaw, Pittman, Potts & Trowbridge Vice Chairperson 1800 M Street, NW Lakeshore Citizens for Washington, D. C.
20036 Safe Energy 932 N. 5th Street Document Department Manitowoc, Wisconsin 54220 University of Wisconsin -
Stevens Point Library Atomic Safety and Licensing Stevens Point, Wisconsin 54481 Board Panel U. S. Nuclear Regulatory Wisconsin Electric Power Company Commission ATTN:
Mr. Glen Reed, Manager Washington, D. C.
20555 Nuclear Power Division Point Beach Nuclear Plant Atomic Safety and Licensing 221 West Michigan Street Appeal Board Milwaukee, Wisconsin 53201 U. S. Nuclear Regulatory Comnission Marshall E. Miller, Esq., Chairman Washington, D. C.
20555 Atomic Safety and Licensing Board U. S. Nuclear Regulatory Cornission Dosxeting and Service Section Washington, D. C.
20555 Office of the Secretary U. S. Nuclear Regulatory Dr. Emmeth A. Luebke Commission Atomic Safety and Licensing Board Washington, D. C.
20555 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Dr. Paul W. Pardom 245 Gulph Hills Road Radnor, PA 19087 Patrick W. Walsh, Esq.
Assistant Attorney General The State of Wisconsin Department of Justice 114 East, State Capitol Madison, Wisconsin 53702 George F. Trowbridge, Esq.
Bruce W. Churchill, Esc.
Shat, Pittman, Potts, &
Trowbridge 1800 M Street, NW Washington, D. C.
20036
E REQUEST FOR ADDITIONAL INFORMATION POIriT BEACH UtlIT 1 AND 2 SPENT FUEL PCOL EXPANSION 1.
The October 10, 1978, response to request C-13, regarding the dropped fuel assembly analysis, indicates a kinetic energy of 4,275 ft-lbs based on the 1425 lb weight of a fuel assembly.
Since in the event of a crane failure the fuel handling tool would be dropped along with the fuel assembly its weight should be included in calculating the impact energy.
State the impact energy of the fuel bundle and fuel handling tool together and provide the results of the drop analysis based on this impact.
2.
The response to request C-13 was incomplete. We asked if a fuel assembly would develop the highest kinetic eaergy of all objects that could possibly be dropped into the spent fuel pools.
Please list all heavy loads which traverse the spent fuel pools and indicate their weight and potential drop height.
It is our understanding that during handling of new fuel it is carried over the spent fuel pools.
Discuss the potential impact load on the racks resulting from a drop of a new fuel bundle from an elevated position or describe the procedures for excluding such a postulated drop.
3.
The October 10, 1978, response to request C-13 regardin g the straignt drop of a fuel bundle on top of a rack indicates that the energy absorbtion capability of a box section is approximately 730 f t-lbs per 0.9 inches of deformation. This value was used to predict a total local deformation of approximately 5.25 inches due to the impact of a dropped fuel assembly. The compression test used to establish the energy absorbtion capacity was limited to a defor~ation of 0.911 inches.
Since the load deformation curve was not generated beyond 0.911 inches and tnere is no reason to believe that the curve will repeat itself for additional increments of deformation, provide additional justification for the 5.25 inches value.
4.
The October 10, 1978, response to request C-13 regarding drop of a fuel bundle directly into a storage position assumes that the maximum load which can be transferred to the bottom plate is equal to the Euler Buckling load of the fuel bundle. This approach is incorrect in that a buckled column can continue to transmit load in its deflected shape. Furthermore, the buckling load of the fuel bundle has been incorrectly calculated since the bundle treated as a whole will have a higher buckling Icad than the sum of the individaul rod's buckling loads.
The integrity of the bottom plate should be re-analyzed using a correct approach such as an energy transfer mechanism.
. 5.
Provide sketches and describe the welds joining the individual fuel cells together.
Discuss the welding procedures that will be used in fabrication of the racks and describe the quality assurance procedures.
6.
The October 10, 1978, response to request C-13 indicates that the kinetic energy of one fourth the weight of the spent fuel assemblies was considered to be absorbed by the rack assembly.
Provide justification for the assumption that only one fourth of the fuel assemblies weight should be considered as opposed to the usual factor of one half.
7.
The imp ct forces of the fuel assemblies on the rack structure should be ccmbined with the seismic loads in the rack. Although the phasing may not be known the resultant stresses can be combined by SRSS.
Provide results of the analysis combining the impact and seismic loads.
8.
Demonstrate that the fuel assemblies themselves will retain their integrity and will not suffer cladding damage as a result of impacting the storage can during a seismic event.
9.
Discuss the potential for rocking and uplift of the racks during seismic events.
Is impacting at the tcp of the racks possible?
If rocking of the racks can occur provide the calculations to demonstrate the integ,'ity of the spent fuel pool floor under the additional impact loads.
10.
Section 2.5, " Cask Energy Absorbing Frame" of Revision 2 to the Jne 1: sutmittal states that the kinetic energy of the cask during SSE was calculated based on SCT average acceleration. Explain the term "5Ct average acceleration", and describe the failure criteria used for evaluating the f rame.
11.
Discuss how the walls and floor of the spent fuel pool were enalyzed for the loads imparted by the storage racks and the cask energy absorbing frame.
Include a description of the modeling techniques used.
12.
Describe the extent to which interaction between storage racks was analyzed including the modeling techniques and boundary conditions.
13.
Describe how seismic forces will be transmjtted across the tool storage area in the spent fuel pool.
14 Quantify the maximum stress levels in the feet of the rack bases including the stresses in the threads of the leveling screws.
. 15.
The worst postulated thermal transient in the spent fuel pool corresponds to a maximum surface temperature of 212 F resulting from boiling of the spent fuel pool water.
Are all the required load combinations satisfied assuming appropriate temperatures in the boiling condition?
- 16. Quantify the damping values used in the analysis of the racks.
- 17. Describe the load path through the seismic restraints into the racks and describe the analysis performed to ensure that the racks are capable of handling the high localized stresses at the juction of the restraints to the racks.
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