Method of Introducing Discrete Irradiation Data into Simulation of In-pile Service Behavior in Plate-type Nuclear Fuel Element

The irradiation conditions for the nuclear fuel elements are generally given as a bunch of discrete data. It is a critical issue to introduce the discrete irradiation data into the numerical simulation of the thermo-mechanical in-pile behavior in fuel elements. In this study, taking the plate-type dispersion nuclear element as the research object, a set of approaches were established to process the discrete data into the specific data format. A searching algorithm was built to locate the data-element and its irradiation conditions according to the integral point coordinates, and the irradiation conditions for each integral point were obtained by the interpolation algorithm. The algorithms were programmed in FORTRAN language and involved into the user subroutines to define the thermo-mechanical constitutive relations for the nuclear materials and heat generation for the equivalent fuel meat. Hence, the discrete-type heterogeneous irradiation conditions can be introduced into finite element calculation. The correctness and effectiveness of the method are validated with the output of discrete irradiation data.