Colophon

The cover is intended to symbolize a hopeful future shining in the sky. The sky is clear blue, similar to the color of the JAEA logo. The white hexagons are arranged in a pattern similar to that in a tortoise shell, which symbolizes the wish of the people for long lives since ancient times in Japan. Coincidentally, this shape is the same as that of core fuel assemblies in both the prototype fast breeder reactor “MONJU” and the high temperature engineering test reactor “HTTR”.

The images on the cover show decontamination of pavement using shot blasting (top left) and decontamination of soil using a poly-ion complex (bottom right).

Shot blasting uses small iron balls (typically, around 1 mm in diameter) to remove a thin layer from a flat surface. We applied this process, which has been used in nuclear facilities, to pavement at Okuma town, and found that it could reduce the surface contaminant density by more than 90% (Topic 1-8, p.19).

Soil decontamination using a poly-ion complex was tested on a 1500 m² recreation ground at a community center in Oguni, Ryozen, Date-city, Fukushima. The test removed 85∼90% of radioactive cesium by stripping 2 cm of surface soil from the ground (July, 2011) (Topic 1-10, p.21).