Selective separation of heat-generating nuclide by silica gels loaded with ammonium molybdophosphate; Adv.-ORIENT cycle development

Endo, Yusuke*; Wu, Y.*; Mimura, Hitoshi*; Niibori, Yuichi*; Koyama, Shinichi  ; Onishi, Takashi  ; Obayashi, Hiroshi ; Yamagishi, Isao ; Ozawa, Masaki

The separation of heat-generating nuclide (Cs) from high-level liquid wastes is important in relation to the waste volume reduction. The present paper deals with the preparation of Cs-selective ion-exchangers (silica gels loaded with ammonium molybdophosphate, AMP-SG), uptake properties and characterization. The AMP-SG exhibited large distribution coefficient above 10 cm/g for Cs even in the 2-3 M HNO solution. The uptake isotherm of Cs followed a Langmuir-type equation, and the maximum Cs capacity was 0.24 mmol/g. The breakthrough curves of Cs had S-shaped profile, and the 94% of Cs adsorbed on the AMP-SG column was eluted with 5 M NHNO - 1 M HNO solution. The eluent containing ammonium salt is suitable for both the recovery of Cs and the regeneration of AMP-SG. The precise chromatographic separation of Cs and Rb was also accomplished by using mixed solutions of NHNO and HNO.