Radiolytic degradation of an extractant for actinides; HONTA a comparative study of direct and indirect radiolysis processes

Kumagai, Yuta   ; Toigawa, Tomohiro   ; Yamashita, Shinichi*; Matsumura, Tatsuro  

Ionizing radiation induces degradation of organic molecules. This action of ionizing radiation needs to be incorporated in designing and safety evaluation of solvent extraction processes for separation of radioactive elements. A reliable estimation of the effect of radiolysis requires understanding of the degradation mechanism as well as basic data regarding the extractant degradation and its radiolytic products. This study focuses on a promising extractant for separation of actinides from lanthanides, ,,',','',''- hexaoctyl- nitrilotriacetamide (HONTA). We have investigated the radiolysis of HONTA by LC-MS/MS analysis of radiolytic products of HONTA and by UV-visible spectroscopy of its radical transient using pulse radiolysis technique. In these experiments, radiolysis of neat HONTA and that of HONTA in dodecane solvent are compared in order to understand the degradation mechanism.