Disposition of nuclear waste using sub-critical accelerator driven systems

development of accelerator-driven transmutation of waste (ATW) to provide an alternative technological option to the disposition of nuclear waste. Although the concept of accelerator-driven systems has been proposed before under different circumstances,1,2,3 it has only become technically feasible in recent years due to the advent of high-current, high-power accelerators. We arrived at the current concept of ATW after assessing the US national need for an alternative solution to the disposition of nuclear waste, and critically evaluating the state of accelerator, nuclear and processing technologies. Current US policy for disposition of high level nuclear waste (mostly spent fuel) is to store unreprocessed spent fuel in a geologic repository. By 2015, there will be over 70 00 tonnes of spent fuel with 600 tonnes of tra suranic elements, of which over 500 tonnes will be plutonium. Studies have shown4,5 that the long-term radiological risk associated with the repository is from the long-lived transuranic elements (TRUs) and the fission products Tc-99 and I-129; thermal loading concerns arise mainly from the short-lived fissio