ML20214W696

Request for Addl Info Re High Density Rack Spent Fuel Pool Expansion,Including Discussion of Existing Variations Among Three Load Combinations.Variation Used for Rack Design Should Be Identified

ML20214W696
Person / Time
Site:	Vermont Yankee
Issue date:	07/24/1986
From:	NRC
To:
Shared Package
ML20214W686	List: IA-86-803, Request for Addl Info Re High Density Rack Spent Fuel Pool Expansion,Including Discussion of Existing Variations Among Three Load Combinations.Variation Used for Rack Design Should Be Identified ML20214W683 ML20214W696
References
FOIA-86-803 NUDOCS 8612100372
Download: ML20214W696 (3)

Text

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ENCLOSURE i

REQUEST FOR ADDITIONAL INFORMATION FOR VERMONT YANKEE

. ~ RELATING TO HIGH DENSITY RACK - 5 PENT ' FUEL POOL EXPANSION DOCKET N0. 50-271

Reference:

" Vermont Yankee Spent Fuel Storage Rack Replacement Report"-

• April, 1986. ,

1) There are three load combinations provided in the report; pages 20, 71 and 88. Please discuss why there exist variations among three combinations and state which one was used for the rack design . Currently, the staff review is based on 1979 NRC position paper together with ASME Section III, subsection NF, 1980 for stress limits. -

2) It appears that there are errors in stress limits associated with the load combination in page 72. Sy is not allowed for levels A and 8 stress limits. Please clarify. ,

3) Definition of 5 (section strength) is not clear. Provide an example and a justification for using S as a stress limit. (page 72)

4) It is stated that "the nonlinear three-dimensional model adequately represent the effects of impacting, friction and hydrodynamic coupling" (p. 74). Provide mathematical expressions for each component and discuss how such expressions are coded into the computer program. Provide experimental evidence that such mathematical expression together with numerical solution employed in the program indeed represent physical behaviors.

5) Provide a stability analysis for the nonlinear equation that governs rack dynamic response (p. 75-76). One should demonstrate that small changes in input parameters do not result into large changes in resultant values such as sliding and uplif t of the rack. Parameters one should consider are damping, friction or any other major input such as forces and forcing frequencies. Some examples of stability analysis are demonstrated in i

, " Nonlinear Vibration" by J.J. Stoker, Interscience Publishers and "

Analysis of Numerical Methods" by Isaacson and Keller, John Wiley.

8612100372 861205 PDR FOIA PDR GRADEH86-803

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It is~ stated in the report (p. 90) that " Euler bucklin'g load for one

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6) storage cell is 105.7k". Provide a calculation for the buckling load ,

together with a schematic drawing of the mathematical model. Demonstrate that a dynamic effect of dropped fuel assembly is considered in'the buckling calculation.

7) In the report (p. 75), it is stated that "three conditions of fuel storage were analyzed; full, half full and empty. Consider a case where only two or three extreme outer cells are loaded while rest of the cells are empty. Demonstrate that the rack does not tip over considering the fact that the rack support pads are recessed from the outer edge of,the rack.

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Mr. R. W. Capstick Vemont Yankee Nuclear Power Corporation Vermont Yankee Nuclear Power Station -

CC:

Mr. J. G. Weigand W. P. Murphy, Vice President f.

President & Chief Executive Officer Manager of Operations Vermont Yankee Nuclear Power Corp. Yemont Yankee Nuclear Power Corp.

R. D. 5, Box 169 R. D. 5, Box 169 Ferry Road Ferry Road Brattleboro, Vemont 05301 Brattleboro, Vernont 05301 Mr. Donald Munter, Vice President Mr. Gerald Tarrant . Comissioner Vermont Yankee Nuclear Power Corp. Vermont Department of Public Service 1671 Worcester Road 120 State Street Framingham, Massachusetts 01701 Montpelier, Vermont 05602 New England Coalition en Nuclear Pollution Hill ar.d Dale Farm Public Service Board R. D. 2 Box 223 State of Vemont Putney, Vement 05346 120 State Street Mr. Walter Zaluzny Chairman, Board of Selectnan Vemont Yankee Decommissionirg Post Of' ice Box 116 Alliance Vernon, Vemont 05345 Box 53 Montpelier, Verront 05602-0053 J. P. Pelletier, Plant Manager Vermont Yankee fluclear Power Corp.

Post Office Box 157 Resident Inspector Vernon, Vemont 05354 U. S. Nuclear Regulatory Corrission Post Office Box 176 Raymond N. McCandless Vernon, Verront 05354 Vemont Division of Occupatienti A Radiological h alth Yemont Public Interest Administration Butic"ag Research Group, Inc.

10 Baldwin Street 43 State Street Montpelier, Yemont 05602 Montpelier, Vermont 05E02 Honorable lohn J. Easton Thomas A. Murley Attorney General Regional Adninistrator State of Vermont Region ! Office 109 State Street U. S. Iuclear Regulatory Cerrission Montpelier Vermont 05602 631 Park Avenue King of Prussia, Pennsylvania 19406 John A. P.itscher, Esquire Ropes & Gray 225 Franklin Street .

Boston, Massachusetts 02110}