Power reactors

The principles and main practical features of the important types of power reactors for central power generation are described. The prerequisites for a reactor such as choice of moderator and characteristic neutron spectrum and the method of reactor control are considered. The main power reactor types -thermal and fast (neutron energy spectrum) are described, including water cooled and moderated PWR and BWR and the older Magnox and CANDU types based on natural uranium. The PWR type reactors account for 60% of the world's commercial power production and are given special attention. Gas cooled, Magnox and AGR type reactors are still of considerable importance in the U.K. Fast reactors and liquid - metal cooled breeder reactors were conceived as the successors to present day reactors when uranium supplies became scarce. Future perspectives include reactor types which can burn as additional fuel unwanted stockpiles of plutonium mixed oxide (MOX) assemblies. Future designs which encompass built-in passive safety e.g. the Safe Integral Reactor (SIR) are considered. (UK)