10. Health Physics and Waste Management

概要

INTRODUCTION: Important aspects of the study can be found in the following keywords, such as safety, secu- rity, hygiene and disaster prevention. Nuclear research reactor is one of representative facilities together with these keywords under their operation. It is effective to investigate the latest status on practical measures on these keywords in various facilities including nuclear research reactors, to compare each other among facilities, and to discuss more optimized ones for our positive safety management. Through this process, it is also essential to investigate the latest international and/or national regula- tions and the movement of revision of them. In addition, development of human resource and public literacy on nuclear science and technology is also within the scope of the research. The total discussion contents and their fruits are directly useful for all relating laboratories.

INTRODUCTION: Among organochlorine and bromine compounds, persistent organic pollutants (POPs) are subject to international regulation, but the number of POPs is increasing year by year, so extractable organo- chlorine (EOCl) and extractable organobromine (EOBr) have attracted attention as a comprehensive risk assess- ment including related and alternative substances [1]. However, from a safety perspective, it is necessary to volatilize the liquid content of volatile liquid samples and measure them as solid samples [2]. However, the large chlorine and bromine content of filter paper, which is used as a medium to attach components to, has limited the quantification of EOCl and EOBr. Therefore, the ob- jective of this study was to investigate alternative materi- als to the filter paper used in sample preparation. Empty samples were prepared using various materials to deter- mine the amount of chlorine and bromine as background, and the ability of those to attach components was com- pared using extracts of sediment samples.

INTRODUCTION: Decontamination of forests con- taminated by the Fukushima Daiichi Nuclear Power Plant accident in March 2011 is required. In this study, we con- sidered decontamination using the reverse tillage method as a method to reduce the radiation dose in the air without generating soil to be removed. In this method, the upper layer of soil with a high concentration of radioactive Cs is replaced with the lower layer with a low concentration to decrease the radiation dose in the air. Therefore, we develop a calculation method using QAD-CGGP2R, a direct ray calculation code based on the point-kernel in- tegration method, and G33-GP2R, a sky shine calculation code, as a method for evaluating air dose that also takes land use classification and forest topography conditions into account. Using the developed calculation method and data obtained in actual forests in Fukushima Prefec- ture for the implementation of our KURNS Collaboration Research, we evaluate the reduction effect of air dose when the reverse tillage is implemented in those forests.

INTRODUCTION: KURAMA (Kyoto University RAdi- ation MApping system)-II is a radiation measurement sys- tem characterized by its compactness, autonomous opera- tion, and acquisition of pulse-height spectrum data (Fig. 1) [1]. KURAMA-II measures ambient dose equivalent rate (hereafter referred to as air dose rate) and GPS position and automatically transmits them to a dedicated cloud server. We evaluated the effectiveness of a backpack style KURAMA-II (Fig. 2) for the radiation monitoring of pub- lic facilities in Fukushima prefecture by comparing it with a NaI(Tl) scintillation survey meter conventionally used in radiation monitoring.

INTRODUCTION: In order to contribute to the eluci- dation of the mechanism of radioactive contamination, which is one of the issues of NDF6, penetration and elu- tion tests of Cs were conducted on concrete as a structur- al material in the containment vessel of a nuclear reactor. INAA, PIXE, and ICP-MS were used for quantitative analysis of Cs in these experiments.

この論文で使われている画像