Separation of 3H, 14C, 32P, 35S, 125I, and 131I in radioisotope waste

Measurement of 3H, 14C, 32P, 35S, 125I, and 131I in radioisotope (RI) waste materials such as the vials, pipette tips, tubes, syringes, and paper generated from the industrial, medical, educational, and research organizations were conducted by a wet oxidation method. Counts were obtained by a liquid scintillation counter for 3H, 14C, and 32P; a gas proportional counter for 35S; a low energy photon spectroscopy for 125I; and an HPGe detector for 131I. After the treatment of approximately 20 g of the sample, the counting value was determined to obtain a minimum detectable activity (MDA) of approximately 1 x 10-3 ∼ 5 x 10-2 Bq/g. The specific activities of short-half-life RIs (32P, 35S, 125I, and 131I) were not detectable and/or resulted in a low value (<1 Bq/g). The waste containing 3H and 14C was observed to have the specific activities in the range of 10-2-105 and 10-2-104 Bq/g, respectively. (author)