A Simple Method of Calculating the Radial Temperature Distribution in a Mixed-Oxide Fuel Element

Approximate solutions in analytic form are presented for the heat-flow equation that yields temperature as a function of radial position in mixed-oxide fuel irradiated in a fast-neutron flux. These equations are applied to fuel with density that varies due to restructuring. In addition, the necessary thermal conductivity data are discussed. Results, which do not require the use of a computer, are compared with a computer-generated numerical solution and the agreement is shown to be within a few percent.