Development of sodium determination in high active liquid waste using ion selective electrode

Aoya, Juri; Kono, Soma  ; Yamamoto, Masahiko   ; Inada, Satoshi; Kuno, Takehiko 

Vitrification of high active liquid waste (HALW) is a top priority toward the decommissioning of Tokai Reprocessing Plant. Concentration of Sodium (Na) in HALW is required to be analyzed accurately and quickly for the vitrification process control, because it affects viscosity of molten glass and element leaching rate from the vitrified waste. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is modified for remote operation by manipulator in the hot cell, is used for determination of Na in HALW. However, the trouble of the ICP-OES generally requires long recovery time and causes possibility of the vitrification process delay. Therefore, for alternative determination method to prevent the vitrification process delay, Na determination method in HALW using Na-ion selective electrode, which measures electromotive force generated in accordance with ion concentration in solution sample is developed. In this study, influences by hydrogen ion (H) and the other coexistent elements on analytical performance, and measurement results of Na in HALW by the ion selective electrode are reported.