The Concept of dose system for radiological protection

Hirayama, Hideo*; Nakashima, Hiroshi; Sanami, Toshiya*; Yamaguchi, Yasuhiro; Sato, Osamu*; Takagi, Shunji*; Suzuki, Toshikazu*; Iwai, Satoshi*

Since the accident at the Fukushima Daiichi Power Plant, units of radiation doses such as Sv have been frequently reported by newspapers. However, it is not exactly understood even by experts on nuclear engineering that there are two different concepts which are the protection quantity such as the effective dose related to a radiation health risk and the practical quantity such as ambient dose equivalents related to measurements. In this special issue, Radiological Protection Quantity, and Operational Quantity and Radiological Protection Quantity, explain the radiation protection dose system including the protection and practical quantities established by ICRP and ICRU. Relation between Dosimeters used at Fukushima etc. and Radiological Protection Quantity describes a method and its problems to measure radiations from Cs on surface and underground using survey meters and personal dosimeters, and convert the measured values to effective doses.