Research on alpha particles in the stagnant water of Fukushima Daiichi Nuclear Power Station

Yomogida, Takumi   

As one of decommissioning process of Fukushima Daiichi Nuclear Power Station, treatment of stagnant water in the reactor building is now in progress. Our group investigated the particle size and chemical form of particulate -nuclides in the stagnant water in the torus room of Unit 2 to understand the morphology of -nuclides for the safe treatment of the stagnant water. The analysis of particles with -nuclides by SEM-EDX and alpha-track detection revealed that U was in the form of particles ranging from several hundred nm to several m, while other -nuclides (Pu, Am, Cm) were distributed on iron oxide particles. The information of morphology of the -nuclides was used in the design of a purification system to remove particles containing -nuclides from the stagnant water.