Prospects of Heavy-Water Reactor Development in Czechoslovakia

The advantages of the heavy-water reactor for the Czechoslovak nuclear power programme are briefly discussed in the introduction. The results of comparative studies of three heavy-water reactor types of 500 MW(e) are given: (a) gas-cooled reactor fueled with natural metallic uranium; (b) gas-cooled reactor fueled with natural UO2; and (c) organic-cooled reactor fueled with natural UC (DOR). These types are evaluated from the point of view of technical parameters, utilization of accumulated technical and operational experiences, further requirements for development, needs and possibilities of import, etc. It is concluded that there are serious doubts about the future prospects of the DOR type under Czechoslovak conditions; future development should work towards improvement of the gas-cooled reactors. The economic realization of the gas-cooled reactor fueled with natural UO2 currently depends on suitable fuel element cladding material which has not been developed yet. In the first stage of development it is therefore supposed to improve the reactor with metallic natural fuel. The prototype of this reactor of 150 MW(e) is under construction in Slovakia. A power reactor project of 300 MW net of the same type has been worked up. It includes a number of technical improvements leading to better economical parameters. The reactor design of 500 MW net of the same type is being worked up in two alternatives, namely: the current conception in the steel pressure vessel, and the integral conception in the concrete pressure vessel. The comparison of technical parameters of the above-mentioned output stages is discussed. (author)