希土類資源開発と自然放射線源の放射線防護

抄録

There is growing demand for rare earth elements as raw materials for industrial goods such as high performance magnet. Thus, rare earth resources attract a lot of strategic attention internationally. The rare earth ore often contains uranium and thorium, that are Naturally Occurring Radioactive Material (NORM). Usually, such radioactive substances almost remain in the waste yielded in the extraction process for rare earth elements. Therefore, radiation protection is required in all of operation phases from mining and refining to waste disposal, and it is appropriate to the purpose to use the reference level of intervention in the ICRP recommendation. To ensure resource development, it is important that sites where wastes were disposed of are reused under monitored natural attenuation of the chemical conditions of the wastes after early physical stabilization of the land. This paper illustrates current status of rare earth development along with related radiation protection issue.