Magnetic separation - Advanced nanotechnology for future nuclear fuel recycle

The United States and other countries around the world looking to nuclear power for their energy needs must consider how spent fuel will be handled as they construct new nuclear plants and examine existing ones, especially in light of the recent crisis in Japan. With long term storage of used nuclear fuel, there is potential for contaminating ground water due to the performance of interim and long term geologic storage containers. Without the recycle of the minor actinides (Np, Am, Cm), no significant reduction in the radiological hazard of the waste is obtained. The unique properties of magnetic nanoparticles (MNPs), such as their extremely small size and high surface area to volume ratio, provide better kinetics for the adsorption of metal ions from aqueous solutions. In this work, we demonstrated the separation of minor actinides using complex conjugates of MNPs with diethylenetriamine-pentaacetic acid (DTPA) chelator. The sorption results show the strong affinity of DTPA towards Am (III) and Pu (IV) by extracting 97% and 80% of actinides, respectively. If these long-term heat generating actinides can be efficiently removed from the used fuel raffinates, the volume of material that can be placed in a given amount of repository space can be significantly increased.