Development of a Shielded Ion Microprobe Analyzer (SIMA) and Its Application to Fast Reactor Fuel Elements

A shielded ion microprobe analyzer for elemental and isotopic analyses of irradiated fast reactor fuel and fuel component has been developed and installed in an alpha-gamma hot cell. Radiation shielding of the equipment ensures the radiation dose of <2 mR/h (5.16 × 10⁻⁷ C/kg) for 5 Ci (1.85 × 10¹¹ Bq) of a ⁶⁰Co source. Hot samples can be automatically transferred from the cell to the sample chamber of the analyzer. Contamination inside the equipment through sputtering of the radioactive materials can be reduced with a special device. Distribution and migration of fission products, such as ¹³⁷Cs, ¹³⁸Ba, and ⁹⁰Sr, and of fissile materials, such as ²³⁵U and ²³⁹Pu in irradiated mixed-oxide fuel, and isotopic ratios of the elements can be obtained very precisely and quickly.