Development of radiation protection on TENORM

Some of technologically enhanced naturally occurring radioactive material (TENORM), such as radon and monazite sand, gradually became a target for radiological protection. In order to regulate TENORM safely and economically, it is essential to consider the characteristics of TENORM such as ubiquity, huge volume, and very low activity levels. In this paper, radiation protection principles and standards for NORM/TENORM are summarized based on the reports published by the international organizations (e.g. ICRP and IAEA) to assist the development of national regulatory framework. The survey results on the present Japanese situations on industries related to NORM/TENORM are provided, and the categorization for NORM/TENORM, which is established by the Radiation Council of Japan, is explained how to control NORM/TENORM based on their exposure doses instead of their activity levels. Finally, basic processes to solve the problems related to NORM/TENORM are discussed. (author)