Fuel cycle strategies should satisfy a range of criteria for optimising performance (Ion and Bonser, 1997). Clearly they should aim to utilise the available fissile material in full. This might be achieved by recycling of uranium and plutonium from already irradiated fuel or through other sources. The total fuel cycle costs must also be optimised in order to maximise the utilities’ performance from an economic perspective. There is increasing tightening of regulations from national governments and international bodies such as the EC on environmental releases. The impacts of fuel cycle operations on the environment should be minimised by optimised waste and spent fuel management planning. Since fuel cycle activities inevitably involve the handling of fissile material through reprocessing or other means; the political and proliferation issues must also be adequately managed.

The notion of a holistic fuel cycle has been put forward by BNFL; the main elements are summarised in Table 5.1. The holistic approach recognises that different systems and fuel cycle policies can exist in various countries but it is sufficiently flexible to accommodate

such differences. The approach has been adopted for current fuel cycles, e. g. for the AGR fuel cycle in the UK, for MOX fuel cycles in LWRs (light water reactors) and for LWR fuel in CANDUs. The approach is also being adopted for advanced fuel designs.