ANALYSIS OF THE TRANSIENT CONDUCTION OF HEAT IN LONG SOLID CYLINDRICAL FUEL ELEMENTS FOR NUCLEAR REACTORS

摘要

A mathematical procedure using the finite Hankel transform is .employed to obtain a solution for the transient heat flux and radial tempera-ture distribution in a long solid cylindrical nuclear, reactor fuel element. The conditions assumed are: axial symmetry;constant material properties, sink temperature, and boundary conductance;and a heat generation rate which varies radially in accordance with thermal neutron diffusion theory and is any arbitrary function of time.nThe equations are used to compute numerical examples for com¬parison with the results of more approximate methods. An attempt is made to show by numerical evaluation the effect on the accuracy of the com¬puted results of changes in material properties and heat transfer coefficients over the range experienced in one of the Hanford reactors.nIn order to provide a means of attack on reactor transient problems involving large changes in the coolant temperature, an adaptation of the analytic solution appropriate for use in a step-wise calculation procedure is developed.nThe results obtained are applicable in general to the problems of transient cooling of heterogeneous reactors employing long solid cylindrical fuel elements.