Simple cation-exchange separation for ICP-MS measurement of Se in spent nuclear fuel sample

Asai, Shiho; Hanzawa, Yukiko  ; Suzuki, Hideya; Toshimitsu, Masaaki; Okumura, Keisuke ; Shinohara, Nobuo ; Kimura, Takaumi ; Inagawa, Jun; Suzuki, Kensuke*; Kaneko, Satoru*

Inventory estimation of Se in HLW is important for long-term safety assessment of a geological repository. In this study, a simple separation method using a single cation-exchange column has been investigated. An irradiated UO pellet was dissolved and diluted with 1M nitric acid. A known amount of Se was added to the sample for isotope dilution mass spectrometry. The Se -spiked and non-spiked samples were fed to each cation-exchange resin-packed column, followed by washing with 1M nitric acid. The first 3 mL of the effluent was directly injected to the ICP-MS. The recovery of Se was 92%, while no leakage of Gd, which causes major isobaric interference on Se detection, was observed. The coexisting components with high activity were retained on the column, leading to decrease in the surface dose rate to a background level. The amounts of Se and Se in the sample solution were 2.4 0.7 and 13.3 4.6 ng, respectively.