放射性廃棄物の現状と課題

抄録

This paper is a review of the present status of medical radioactive waste management. The primary sources of radioactive waste arise from medical utilization involving in in vivo tests, in-- vivo treatments, in vitro tests, and activated materials. Radioactive wastes contaminated by 19clinically applied radioisotopes (RI) are classified as " Medical" by The Japanese Radioisotope Association (JRA). Medical solid and liquid wastes are routinely collected and disposed of by The JRA at their Takizawa Institute. Medical radioactive wastes amount to about 44% of all collected radioactive refuse in Japan with the exception of power plants.
The half-lives of these RI are relatively short. Pos i tron emitters, for example, used for PET tests have very short half-lives ranging from about a few minutes to an hour. Materials contaminated by these RI are legally disposed of as radioactive wastes. In contrast, radioactive contamination found in the underware of 131 I in -vivo treated patients is not legally controlled. Activated parts of cyclotrons; target foils, electrodes etc., are also not legally controlled and are voluntarily isolated at each facility.