Colophon

The cover is designed to envisage a hopeful future shining in the sky which is a clear blue like the color of the JAEA logo. This is accompanied with white colored hexagons similar to the pattern in a tortoise shell which symbolizes the wish of people for longer lives from ancient times in Japan. Coincidentally, this shape is the same as that of core fuel assemblies for both the prototype fast breeder reactor “MONJU”, and the high temperature engineering test reactor “HTTR”.

The images on the cover show the analytical results of air dose rate obtained by using WSPEEDI (top left), and view up inside the Main Shaft from GL -400 m (400 m below ground level) at Mizunami (bottom right).

The former shows the estimated results of the behavior of radioactive nuclides discharged from the Fukushima Daiichi NPS during the period from March 15 to 16, 2011. The high air dose rate in the northwest direction from the plant can be explained by this analysis (Topic chapter 7 introduction).

The latter shows the Main Shaft at the Mizunami Underground Research Laboratory. Its diameter is 6.5 m. As of March 2011, the excavation of the Main Shaft had reached GL -481.3 m. The image is view up inside the Main Shaft from GL -400 m (Topic 12-11).