Distribution of the Cs/Cs ratio around the Fukushima Daiichi Nuclear Power Plant using an unmanned helicopter radiation monitoring system

Nishizawa, Yukiyasu; Yoshida, Mami; Sanada, Yukihisa; Torii, Tatsuo

Journal of Nuclear Science and Technology, 53(4), p.468 - 474, 2016/04

https://doi.org/10.1080/00223131.2015.1071721

Report for "FY 2013 Evaluation of Decontamination Technology Demonstrations Projects for the environmental remediation with radioactive materials discharged from the Fukushima Daiichi Nuclear Power Plant Accident" (Contract research)

Watanabe, Masahisa; Tagawa, Akihiro; Umemiya, Noriko; Maruyama, Noboru; Yoshida, Mami; Kawase, Keiichi; Noguchi, Shinichi; Sakazume, Yoshinori; Watanabe, Masanori; Hiraga, Hayato; et al.

JAEA-Review 2014-028, 184 Pages, 2014/10

JAEA-Review-2014-028.pdf:37.79MB

JAEA received technical proposals from private enterprise about techniques that can be used for decontamination work, and "Decontamination Technology Demonstrations Projects" was commissioned from the Ministry of the Environment to verifies the decontamination effect, economy feasibility, safety, and other factors. By the "FY 2013 Decontamination Technology Demonstrations Projects" JAEA carried out technical advice of demonstration test and evaluation of 11 technologies (e.g., decontamination of soils and green space and wastes and washing of fly ash).

Analysis of each radionuclides discharged by the Fukushima Daiichi Nuclear Power Station accident measured by airborne surveys

Nishizawa, Yukiyasu; Yoshida, Mami; Sanada, Yukihisa; Torii, Tatsuo

no journal, , 

Many radioactive substances were released by the Fukushima Daiichi Nuclear Power Plant accident occurred on March 11, 2011 in the atmosphere. A lot of short half-life nuclides which are I, Te, etc., in addition to longer half- lived nuclides such as Cs and Cs. The estimated release amount of these nuclides from the reactor 1st to 3rd unit is reported, but it's found to be quite different in the short half-lived nuclides by the reactor units. Because the radioactivity ratio of Cs and Cs was slight different between the reactor units, it can be considered that the valuable source is obtained by the measurement of Cs/Cs ratio in the environment around the Fukushima Daiichi Nuclear Power Station at the present stage when the nuclides with short half-lives had already decayed. We have measured high-resolution -ray spectrum using an unmanned helicopter equipped with LaBr(Ce) detector in a 3-km range from the power station which was near to the release source of the radioactive cesium. Because the LaBr(Ce) detector has high resolution of rays, the discrimination of many nuclides is possible. In addition, there is extremely much number of the data provided by the distribution measurement with the unmanned helicopter. Because a new map was illustrated by the analysis of the Cs/Cs ratio, we report the outline.

The Current situations and issues of the airborne radiation monitoring, 3; Distribution of the Cs-134/Cs-137 ratio around the Fukushima Daiichi Nuclear Power Plant using an unmanned helicopter radiation monitoring system

Nishizawa, Yukiyasu; Yoshida, Mami*; Sanada, Yukihisa; Torii, Tatsuo

no journal, , 

no abstracts in English