The proliferation of plutonium and the threat from terrorism in modern society is a major driver towards a closed fuel cycle. Another driver is to develop a process for effective management of spent fuel and waste. Advanced reactor concepts provide a solution to these requirements.

For many years fast reactors have offered the attraction of a sustainable fuel supply based on a uranium-plutonium fuel cycle. Uranium resources will last for at least 60 years; so from this perspective there is no immediate need for fast breeder reactors, which (in addition) are about 50 times more efficient than current thermal reactors. There is now a current interest in exploring particular advantages of the fast reactor to consume plutonium, and reduce the stockpile of weapons fuel. Also the fast reactor can be used to irradiate minor actinides (MA) and fission products to reduce the toxicity of long-term wastes.

There are a number of international programmes at the present time that aim to develop the above technology. There are EC initiatives in this area; e. g. a review of gas cooled fast reactor concepts (Mitchell et al., 2001) was carried out within the Fifth Framework programme. The review partners concluded that the gas-cooled fast reactor (GCFR) has a number of potential advantages to offer.

The EC CAPRA (Consummation Accrue de Plutonium dans les reacteurs Rapides) project originally focused on technologies to consume existing plutonium stocks arising from the operation of commercial reactors (IAEA-TECDOC-1083, 1999). Work is currently underway in the EC CAPRA/CADRA project to evaluate the potential for the transmutation of plutonium and MA from waste. A wide variety of reactor concepts of metal cooled fast reactors (Smith et al., 2003; Hesketh, 2003; Vasile et al., 2001) are being considered. The aim is to transmute these actinide species to species with much shorter half-lives.

There are also various international activities on the application of proton particle accelerators in connection with subcritical reactor systems as a means of separating and eliminating actinides via transmutation.

Reactor systems for plutonium burning and the partitioning and transmutation of nuclear waste are among those selected for development within the Generation IV initiative.