Design Improvements and a Preliminary Thermal Analysis of an Irradiation Capsule using Lead Bismuth Eutectic Alloy(LBE)

From the study for the design improvements and a preliminary thermal analysis of an LBE capsule, the following results have been obtained: 1. From the neutron radiography for the LBE capsule mockup used for the heat transfer experiments, the expansion of the LBE container was found in the regions of 200∼700mm from the bottom of the mockup. Some parts showed the contact between the internal and external tube due to the phase transformation of LBE during solidification or cooling. 2. Design modifications for reducing the expansion problem and enhancing the safety of a capsule were carried out. Under the current HANARO capsule design practice, a preliminary thermal analysis using a finite element analysis program, ANSYS was carried out to understand the thermal behavior of a newly designed capsule with three heat sources. From the analysis results, it was concluded that an LBE capsule can provide a more favorable environment for a high temperature test, and in addition, the temperature distribution of an LBE capsule in the longitudinal direction is relatively uniform as compared with the data of a single heat source