Recovery and determination of Pd in nuclear fuel used for electricity generation

Asai, Shiho; Yomogida, Takumi   

Palladium found in spent nuclear fuel is characterized by having radiopalladium Pd (Half-life: 6.510 y). With its long half-life, accurate determination of the amount of Pd in spent nuclear fuel is essential for estimating the radiation effects. However, no experimentally determined concentration has been reported due to the difficulties in obtaining pure palladium form spent nuclear fuel with conventional separation techniques. In this study, Pd in spent nuclear fuel solution was separated by precipitation triggered by photoreduction of Pd(II) with pulsed laser irradiation. About 20 min of the irradiation to the spent nuclear fuel solution provides high Pd recovery of more than 90%. The prepared Pd precipitate was dissolved with aqua regia and measured with ICP-MS. Almost no impurities were detected in the Pd precipitate, resulting in the accurate determination of Pd.