Nuclear reactor, types

Hydrogen production process Nuclear reactor type Product flexibility ... 

There are a number of different nuclear reactor types. The most widely used is the light-water reactor, but graphitemoderated types, which are cooled with light-water or gas, are in operation, also heavy-water reactors. The graphitemoderated high temperature reactor is in a state of halted development, as are gas-cooled reactors and fast breeder reactors. 

Abstract The chapter is devoted to the practical application of the fission process, mainly in nuclear reactors. After a historical discussion covering the natural reactors at Oklo and the first attempts to build artificial reactors, the fimdamental principles of chain reactions are discussed. In this context chain reactions with fast and thermal neutrons are covered as well as the process of neutron moderation. Criticality concepts (fission factor 77, criticality factor k) are discussed as well as reactor kinetics and the role of delayed neutrons. Examples of specific nuclear reactor types are presented briefly research reactors (TRIGA and ILL High Flux Reactor), and some reactor types used to drive nuclear power stations (pressurized water reactor [PWR], boiling water reactor [BWR], Reaktor Bolshoi Moshchnosti Kanalny [RBMK], fast breeder reactor [FBR]). The new concept of the accelerator-driven systems (ADS) is presented. The principle of fission weapons is outlined. Finally, the nuclear fuel cycle is briefly covered from mining, chemical isolation of the fuel and preparation of the fuel elements to reprocessing the spent fuel and conditioning for deposit in a final repository. 

There are several different kinds of nuclear reactors that use diverse types of fuel (uranium compounds) that are placed in different sorts of fuel elements and these in turn are arranged in varions fuel assemblies. A detailed survey of these is beyond the scope of this book however an elementary understanding of nuclear fuel and its characterization is highly relevant. Figure 1.14 depicts the main nuclear reactor, types of fuel, moderator, and coolants in service. 

Nuclear reactor types can be classified by power output and by the peak temperatures of their coolants (Fig. XXVI-4). Light water reactors (LWRs), such as the General Electric Economic Simplified Boiling Water Reactor (ESBWR), are low temperature, high pressure reactors. 

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