Fast reactor fuel development

The components of the established fast reactor fuel cycle are illustrated. The reactor operates as part of the cycle. It is explained why this is so and why fuel cannot be left in a fast reactor indefinately but has to be removed, dismantled, dissolved and fabricated to make use of the plutonium in subsequent operating cycles of the reactor. The relatively high costs of this cycle are offset by good performance characteristics of the reactor type. Mixed uranium/plutonium fuel in the form of ceramic oxides, is used in most current and planned fast reactors. The fuel parameters for existing fast reactors are given. The fuel pellets and their manufacture are described. The pellets are packed into metal tubes (cladding) (fuel pins), bundles (200-300) of which are incorporated into sub-assemblies, several hundred of which constitute the core. The PFR sub-assembly is illustrated. Re-processing stages are indicated. (UK)