Development of Pd separation technique based on laser-induced particle formation for determination of Pd in HLW with ICP-MS

Yomogida, Takumi   ; Asai, Shiho; Saeki, Morihisa; Hanzawa, Yukiko  ; Esaka, Fumitaka  ; Oba, Hironori  ; Magara, Masaaki  

Inventory estimation of long-lived fission products (LLFPs) in high-level radioactive waste (HLW) is indispensable for the long-term safety assessment of geological repository. Reliability of the estimated inventory is verified with actual measurement values which are drawn from proven analytical techniques. There has been increasing interest in the development of new determination methods of Pd-107 which is one of the LLFPs with a half-life of 6.510 y because little measured data has been reported. Major difficulty in determination of Pd-107 involves the poor recovery of Pd in separation step required prior to measurement. In this study, a highly selective separation technique based on laser-induced microparticle formation has been applied to Pd separation. The recovery percentage of Pd from a simulated HLW solution were affected by irradiation time and laser pulse energy. The maximum recovery percentage of 60% was achieved by 20-min irradiation at the energy of 100 mJ.