Nuclear energy is one of the most important energy resources of our modern society, therefore, it is strongly demanded to make nuclear fuel cycle more reliable. Also, decommissioning of the severely damaged reactors by Fukushima NPP accident in 2011 and recovery of the contaminated environment, are urgent issues in Japan. To respond these demands, our group investigates chemistry of nuclear fuel debris and leaching behavior of actinides in it by synthesizing simulated fuel debris with actinide tracers. Furthermore, we develop novel and unique nuclear waste solidification processes using functional aluminum silicate minerals as fixation agent.