Whole body counter surveys of Miharu-town school children for four consecutive years after the Fukushima NPP accident

Comprehensive whole-body counter surveys of Miharu town school children have been conducted for four consecutive years, in 2011-2014. This represents the only long-term sampling-bias-free study of its type conducted after the Fukushima Dai-ichi accident. For the first time in 2014, a new device called the Babyscan, which has a low $^{134/137}$Cs MDA of $< 50$ Bq/body, was used to screen the children shorter than 130 cm. No child in this group was found to have detectable level of radiocesium. Using the MDAs, upper limits of daily intake of radiocesium were estimated for each child. For those screened with the Babyscan, the upper intake limits were found to be <1 Bq/day for $^{137}$Cs. Analysis of a questionnaire filled out by the children's parents regarding their food and water consumption shows that the majority of Miharu children regularly consume local and/or home-grown rice and vegetables. This however does not increase the body burden.Comment: 11 pages, 10 figure

Low Activation V-Ti-Cr-Si Type Alloys for Fusion Applications

V-Ti-Cr-Si type alloys containing Al and Y were prepared for structural materials application of fusion reactors. The condition of heat treatment, tensile properties and deformation microstructures were examined for two type alloys referred as V-25Ti-15Cr and V-5Ti-5Cr. The neutron irradiation behavior was also studied. Tensile test were conducted using miniature-type specimens at temperatures from 300 to 1273K. The alloy V-25Ti-15Cr showed the strength twice as high as V-5Ti-5Cr at temperatures from 300 to 873 K. Ductility of V-5Ti-5Cr alloy was larger than that of V-25Ti-15Cr at lower temperatures. The amount of void swelling after neutron irradiation of the two alloys was very low level compared with that of various vanadium alloys