Palladium-107 can be found in high-level radioactive liquid wastes (HLLW). Owing to its long half-life (6.5 million years), determining the 107Pd contents in HLLW is essential to evaluate the long-term safety of HLLW repositories. However, the 107Pd contents in HLLW have not been reported because of difficulties in a pretreatment for the measurement. Treating highly radioactive samples, such as HLLW, may cause radioactive contamination and radiation exposure to workers. Therefore, a simple and non-contact separation procedure is desirable. In this study, we applied a simple and non-contact separation technique based on laser-induced photoreduction to a simulated HLLW solution. The solution, which consisted of 14 major elements (Rb, Sr, Zr, Mo, Ru, Rh, Pd, Cs, Ba, La, Ce, Pr, Nd, Sm) in a 3 mol L−1 HNO3 solution, was used to evaluate the separation performance. The results showed that the recovery of Pd from a simulated HLLW solution depended on the solvent, concentration of ethanol, concentrations of Pd ion, irradiation time and pulse energy. The results indicate that the coexisting elements in a sample hampered the photoreduction of Pd ions or the formation of a Pd precipitate and the loss of a Pd precipitate at centrifugation caused a decrease of the Pd recovery. By considering the conditions at laser irradiation, the results showed that the Pd recovery reached 59 %, while about 99 % of the other 13 elements was removed. This indicates that the non-contact and high-selective separation of Pd is achievable with the proposed separation technique under a suitable separation condition.
