Measurement of gamma spectrum of radioactive waste and working environment by portable germanium detector

Practical application of portable Ge detector was examined in radiation control at the reprocessing plant. Main purposes of the examination are, (1) estimation of radionuclides inventory by in-situ object counting system (ISOCS), and (2) acquisition of the gamma ray energy information which is necessary for dose estimation. At first waste box, analytical jug, filter and lead container were measured. Then gamma spectrum was measured around glove box in Pu conversion development facility (PCDF). As a result, some aspects concerned about detection limit, distribution of point source and self-absorption by low energy gamma ray were clarified. Information on the gamma ray energy were obtained. Radiation control will become advanced by measuring a gamma ray spectrum by portable germanium detector. (author)