ABSTRACT
Although, at the beginning of nuclear energy deployment, many different reactor systems were proposed and more or less tested, only a few of them became standard in the Western hemisphere: light-water reactors like the PWR (pressurized water reactor) or BWR (boiling water reactor), heavywater reactors of the CANDU (Canadian deuterium uranium) type and, finally, the sodium cooled fast-neutron reactors (LMR: liquid metal reactor). It was clear from the beginning that breeder reactors like the LMR were necessary for a sustainable development of nuclear power. However, the experience with the LMR is far from conclusive, especially since the universally used sodium coolant seems to lead to too strong safety constraints on the building and operation of the reactors. Furthermore, light-water reactors are plagued by the problem of radioactive waste which, to date, has not found a consensual solution. The waste problem added to the fear of catastrophic accidents (Chernobyl syndrome) explains the large societal opposition to nuclear power observed in many countries. To some extent one may think that nuclear energy will come to a dead end. This is an unfortunate situation when the rising concern about the greenhouse effect pleads for a severe reduction in the use of fossil fuels. The development of safer and less polluting means of producing energy from nuclear fission is, thus, of great relevance.
