Fundamental Researches on Radiochemistry of Nuclear Fuel Cycle/Part III. Research on the solid chemical characteristics and behavior of irradiated fuels

This first stage report describes "Research on the solid chemical characteristics and behavior of irradiated fuels"(2017. 03 ~ 2018. 12) under national "Nuclear R&D program "Nuclear Technology Development Project". The purpose of this study is to secure the nuclide distribution measurement technology that is essential for the long-term safety assessment of the spent nuclear fuel management, and to study the chemical behavior of major nuclides in the spent fuel and the changes in physicochemical characteristics of the nuclear fuels. This work can be divided by three tasks as establishment and optimization of precision measurement system for local nuclide distribution, establishment of high temperature analysis system and development of analytical measurement and interpretation techniques for chemical behaviors of metallic fuels, and chemical behaviors of the fuel interface depending on the concentration of solid solution elements. The results of this study are high-radioactive handling technologies required for fuel research, which are the core technologies for the fuel cycle. These technologies are expected to be used in the nuclear industry in the future. In the next step, we will acquire local nuclide distribution characteristics data, high-temperature behavior, and interface behavior of the fuels to cope with the data requirements for permits related to recycling, transportation, intermediate storage, and disposal of the spent nuclear fuel. By evaluating the reliability of the developed analytical method, it is expected to secure standardized analytical technology and to provide related technology in response to the chemical measurement needs of the entire nuclear industry.