A medium temperature heat pipe cooled reactor

Abstract

Heat pipe cooled reactor is a potential candidate for special purpose energy supply. The use of high temperature heat pipe results in a high thermal efficiency and a high passive safety. However, its development has been limited by several shortcomings in engineering, such as the restriction of low nuclear power and the material choosing in high temperature, etc. In this work, a Medium temperature Heat pipe cooled Reactor (MHR) with very high inherent safety is proposed. Mercury heat pipes are used to cool the solid reactor with uranium zirconium hydride fuel pins, which results in a limited temperature in reactor core and a low requirement to high temperature materials. The fission heat is transferred to electricity by a superheat steam/water cycle with an efficiency of approximately 33%. The unique merits of the MHR include low requirements to materials, low enrichment, transient negative temperature coefficient, excellent startup characteristics and so on. The control rod worth, neutron energy spectrum, neutron flux distribution, temperature coefficient and core lifetime were analyzed. It was found that the MHR includes a large transient negative temperature coefficient, which means that a sharp reactivity increase in the core could be controlled immediately. Finally, a very high inherent safety is achieved.