COMPUTATIONAL SIMULATION OF RADIATION-INDUCED SHAPE CHANGE IN FUEL ASSEMBLIES OF THE BN-TYPE REACTORS

Abstract

A computational analysis problem of deformation of a hexagonal wrapper tube in a fuel assembly (FA) of sodium-cooled fast reactors (the BN-type reactors), accounting for radiation-induced swelling and radiation-induced creep is solved. Determining equations for calculating the radiation-induced shape changes in FA's using the finite-element method are presented. The material parameters of the radiation-induced shape changes in FA's in are obtained based on the experimental data. The results of computational-and-experimental analysis of the shape changes in the wrapper tube of the BT-type reactor FA accounting for the radiation-induced swelling and radiation-induced creep are given. Results of the studies done showed that blocks developed to take account of the radiation-induced swelling and radiation-induced creep make it possible to analyze the FA shape changes in the core.

Keywords: radiation-induced swelling, radiation-induced creep, fuel assembly, post-irradiation examination, analysis.