Critical Flow Velocities for Collapse of Reactor Parallel-Plate Fuel Assemblies

Theoretical formulas are presented for prediction of the flow velocity at which collapse occurs in long parallelplate assemblies Beyond the critical velocity the pressure-unbalance forces developed as a consequence of a small deflection exceed the corresponding elastic restraining forces, and the plates collapse. Both flat- and curvedplate assemblies are considered, and the applicability of the formulas to design of reactor fuel-plate assemblies is discussed. (auth)