Development of elemental components in NDA systems for certifying radioactive wastes with the clearance level

Tsutsumi, Masahiro; Oishi, Tetsuya*; Yamasoto, Kotaro; Yoshida, Makoto

JAERI-Research 2004-021, 43 Pages, 2004/12

JAERI-Research-2004-021.pdf:8.55MB

We have designed and developed a measurement system to certify radioactive wastes below the clearance level. By advancing non-destructive -ray assay technology, it aims at quantitative determination of radionuclides contained in 200 litter drum/container wastes. Unlike the waste from a nuclear power plant, you have to assume that the waste originating from radioisotope usage and nuclear research laboratory have a variety of contents and a complex mixture of radionuclides, and furthermore the uniformity of activity concentration is unknown. To cope with the problems, we have developed the -ray measuring instruments (units) with effective improvement of capability against each problem. They are (1) germanium spectrometry unit for enhanced peak identification, (2) positioning detection unit for positioning of interactions and (3)high-efficiency detection unit for separation of low-energy component. This report summarizes the direction of the clearance level measuring system and the three developed measuring units with their performances.