[en] As well as differences in the season, there is a difference in the concentration of each year. In addition we consider that crops have different absorption rates of radioactive material depending on the time of the growth status. That will have an impact on how much crops contaminated by radioactive material. That's why we choice the rice plant. And we applied absorbed rate factor to calculate absorbed material density in the rice. The purpose of this study is to compare the results between the ground concentration of radioactive material and absorbed material density in the rice in each season. Lastly we calculate the annual effective dose on the assumption that people eat the contaminated rice in each season from 2008 to 2010. Calculated Effective dose around the 1,3,5 km less than Effective dose limits that 1mSv. It is not give a major impact to public. The different results could be expected, however, if the accident emitting more radioactivity was assumed. We expect that results obtained can be revised after the repeating simulation of MACCS2 with more weather data

[en] To reuse fissile materials through fuel cycle in future nuclear energy system development and achieve safety, economics, optimization of spent fuel management, an information of isotopic fissile content(U235, Pu239, Pu241, MA) is required to be provided basically. LSDS technology development was done to assay isotopic fissile contents. LSDS system consists of spectrometer, source neutron, measurement, data process. In 1st phase (2012-2013), key measurement technology, neutron source technology, conceptual design of detection system and shielding design were done. In the spectrometer, neutron spectrum and resolution analysis, detector design and response, detection model were performed. The optimum shielding model was proposed by shielding dose simulation. In 2nd phase (2014-2016), key parameters were determined in optimized spectrometer, fission detection sensitivity, accelerator and beam dump design, target design and neutron yield analysis, cooling system, material activation, optimized shielding model were done, and finally, mathematical assay model was proposed with software development to isotopic fissile content. Additionally, correction methodology was established by fission signal analysis. Using real U235(4.8%) and Pu239(47g, 91g), fission data was obtained. In fissile assay using various fissile materials, the content of uranium and plutonium was assay with 1-3% error. In the unknown sample, the content of plutonium was analyzed in 1-2% uncertainty. The isotopic fissile content assay technology is required in the reuse by fuel cycle for success of future nuclear energy system development. Moreover, such an advanced new fissile assay technology will lead the international nuclear area and contribute to technology export.