Determination of Iodine-129 in Low Level Radioactive Wastes - 13334

For the radioactivity determination of 129I in the radioactive wastes, alkali fusion and anion-exchange resin separation methods, which are sample pretreatment methods, have been investigated in this study. To separate and quantify the 129I radionuclide in an evaporator bottom and spent resin, the radionuclide was chemically leached from the wastes and adsorbed on an anion exchange resin at pH 4, 7, 9. In the case of dry active waste and another solid type, the alkali fusion method was applied. KNO3 was added as a KOH and oxidizer to the wastes. It was then fused at 450 deg. C for 1 hour. The radioactivity of the separated iodine was measured with a low energy gamma spectrometer after the sample pretreatment. Finally, it was confirmed that the recovery rate of the iodine for the alkali fusion method was 83.6±3.8%, and 86.4±1.6% for the anionic exchange separation method. (authors)