The safe and efficient management of spent fuel from the operation of commercial nuclear power plants is an important issue. Worldwide, more than 250 000 tons of spent fuel from currently operating reactors will require disposal. These numbers account for only high-level radioactive waste generated by present-day power reactors.
Nearly all issues related to risks to future generations arising from the long-term disposal of such spent nuclear fuel is attributable to only about 1% of its content. This 1% is made up primarily of plutonium, neptunium, americium and curium (called transuranic elements) and the long-lived isotopes of iodine and technetium.When transuranics are removed from discharged fuel destined for disposal, the toxic nature of the spent fuel drops below that of natural uranium ore (that which was originally mined for the nuclear fuel) within a period of several hundred to a thousand years. This significantly reduces the burden on geological repositories and the problem of addressing the remaining long-term residues can thus de done in controlled environments having timescales of centuries rather than millennia stretching beyond 10 000 years.
Transmutation is one of the means being explored to address the disposal of transuranic elements. To achieve this, advanced reactors systems, appropriate fuels, separation techniques and associated fuel cycle strategies are required.
This status report begins by providing a clear definition of partitioning and transmutation (P&T), and then describes the state of the art concerning the challenges facing the implementation of P&T, scenario studies and specific issues related to accelerator-driven systems (ADS) dynamics and safety, long-lived fission product transmutation and the impact of nuclear data uncertainty on transmuation system design. The report will be of particular interest to nuclear scientists working on P&T issues as well as advanced fuel cycles in general.