Behavior of metallic precipitate in an irradiated simulated fuel

A simulated fuel specimen which was irradiated at the HANARO research reactor up to 3300 MWd/tU of a burn-up at the condition of 36 kW/m of a maximum linear power was studied by a shielded EPMA (Electron Probe Micro-Analyzer). In order to obtain an accurate analysis results, chemical and EPMA analyses were also performed on un-irradiated fresh simulated fuel, the results of which were compared with those of the irradiated simulated fuel. This study concentrated on the metallic precipitates of the irradiated simulated fuel specimen which contained lots of fission products. Among the several properties of the metallic precipitate, its size and composition were investigated. A large metallic inclusion was also observed in the irradiated simulated fuel, from which X-ray photographs were taken to analyze its properties.