在板型核燃料元件服役行为模拟中引入离散辐照数据的方法

核燃料元件的辐照工况条件一般只能以离散数据的形式给出,如何将其引入元件堆内热力耦合行为的计算模拟中成为一个关键性的问题。本文针对板型弥散核燃料元件,建立了一系列的方法,可将大量的离散辐照数据处理为所需要的数据格式,从文件中精确搜索到所需要的数据点和辐照数据,并插值到元件热力耦合分析单元的积分点。通过编制FORTRAN程序,将离散辐照数据成功地引入定义等效芯体和包壳材料热-力学本构关系的用户材料子程序、定义等效芯体产热率的子程序,从而将离散辐照工况数据引入了元件热力耦合服役行为的有限元计算。通过输出元件堆内行为有限元计算中所实际使用的工况数据,验证了离散辐照数据引入方法的正确性和高效性。

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 condi-tions can be introduced into finite element calculation .The correctness and effectiveness of the method are validated with the output of discrete irradiation data .