Miscellaneous small reactors are needed for many different applications including materials testing and irradiation, isotope production, and reactor and nuclear physics training. Further applications include neutron detector calibration, neutron activation trace element analysis and delayed neutron counting for evaluating fissile content and basic research applications.

A matter of growing concern is the reducing numbers of such reactors that remain in service. However, many of these reactors are ageing and are approaching 50 years of life. They are, therefore, reaching the end of their operational lives. In particular, the EC is currently evaluating the future needs of material test reactors in Europe (Parrat et al., 2003) which provide valuable services within Europe and worldwide. Materials testing facilities are likely to be needed for the development of some of the advanced Generation IV concepts that will include corrosive materials resulting in chemically and physically demanding environments.

Most of the therapeutic isotopes required by industry are currently produced using neutron irradiation in research and small reactors. However, with a potential 10-fold intensity increase in compact cyclotrons, some charged particle reactions are becoming accessible for producing some of the newer isotopes. Reliance on research reactors may diminish as accelerator-based techniques are developed and able to provide adequate technical capability at prices industry can support (Lewis).

There are many novel applications of nuclear energy in medicine at various stages of development. Examples include boron neutron capture therapy (BNCT), a technique being pioneered at Birmingham University for the treatment of cancer. This involves injecting boron into the patient, which concentrates in the affected organ and which is then irradiated. Another example involved a technique that has recently been applied in Italy, where a patient with liver cancer, had the organ removed, irradiated and replaced with successful remission of the tumour.

There are fewer nuclear engineering degree courses now available at the Universities and fewer small reactors available for teaching purposes. In the UK, collaborative research programmes between academia and industry are being undertaken by the University of Birmingham. Current projects in the Nuclear Physics Group relate to modelling of nuclear materials assay equipment and the study on nuclear waste transmutation (http://www. np. ph. bham. ac. uk/research/npt. htm). Academic research is conducted at the Imperial College research reactor, situated in Silwood Park (http://www. imperial. ac. uk/publication/pbb/ env_sci/intro. htm).

Other interesting applications of nuclear energy concern topics such as food irradiation. This is a growing international business (www. sercoassurance. com/answers). The process involves the use of high-energy gamma radiation, produced by a source, to kill bacteria in food and preserve it. Other possible applications include sterilisation of materials and implements for the medical industry.

Small reactors operate with different fuel cycles compared with large power reactors. There are research reactors of diverse design in a number of countries, including Australia (heavy water), India (pool type) and Japan (fast reactor) (http://www. world-nuclear. org/ info/inf61.htm).