The Present Status of High Temperature Reactors

The potential of the HTR lies in the facts that: - the majority of the technical advances and expertise gained in the development and operation of Magnox and AGR power stations is directly applicable to the construction and operation of an HTR station. - the inherent characteristics of the core and fission product barriers provide safety margins which exceed those of any other system. - the present state of technology provides assurance that a station can be built to a programme, built to a budget and operated satisfactorily with the required degree f flexibility. Three reactors, the OECD Dragon Reactor Experiment, the Peach Bottom Reactor and the AVR Pebble Bed Reactor, have been designed, built and operated as test reactors in the process of exploiting the HTR concept and each has the necessary supporting programmes of research and development. There exist, therefore, three independent assemblies of data, interpretation and proof which is a unique situation for any thermal reactor system. This circumstance is particularly important in the extrapolation of behaviour to power reactor sizes and conditions because the models for prediction are cross-checked and key data is measured independently. The result has been that each of these assemblies of information has been scrutinised separately in the process of design, safety assessments and funding of a power reactor in each country. In two of these procedures, the technology and the economic arguments have supported a decision to construct a power station.