RADIOISOTOPES

Decontamination wastes contaminated with radioactive caesium (¹³⁴Cs, ¹³⁷Cs) are housed in the flexible container bags. Flexible container concentration measurement car has been developed for the radioactivity measurement of decontamination waste by Canberra Industries, Inc. For reduction of background, the flexible container bag is mounted to the frame, and measured from the lower side. In the flexible container bag, if there is uneven distribution of the source, the quantification error increases. We proposed the method quantifying the shielding situation of γ rays. As a result, the possibility of quantification accuracy of radioactivity was confirmed.