Current status and prospects of research reactors

Full text: The first nuclear research reactors (RR) appeared in the 1940s. Their initial purpose was to provide knowledge of the main processes associated with neutron-induced nuclear reactions. Later, the range of problems addressed expanded substantially. Besides fundamental research in the properties of matter, such reactors are successfully used for dealing with problems in the fields of materials science, nuclear engineering, medicine, isotope production, education, etc. Over the whole period of RR fleet growth, more than six hundred nuclear research facilities were built in 70 countries of the world. As of the end of 2008, the number of Russian research reactors in service was about 20% of the globally operating RR fleet. This paper discusses the current status of the world's RR fleet and describes the capabilities of the experimental reactor facilities existing in Russia. In the 21st century, research reactors will remain in demand to solve scientific and technological problems for innovative development of society. The emerging renaissance of nuclear power, the expanding RR uses for production of isotopes and other applications, the increase in the number of countries willing to use nuclear technologies in energy production, industry and science - all contribute to a rebirth of interest in research reactors. One of the ways to improve the experimental capabilities lies in radical upgrading of the reactor facilities with qualitative changes in the main neutronic characteristics of the core. The associated design approaches are illustrated with the example of the IBR-2M reactor at the JNRI in Dubna. The imperative need for restricting the spread of nuclear threat leads us to give up using highly enriched uranium in most research reactors. Development of RR fuel with reduced enrichment in uranium has been one of the priority objectives of NIKIET for many years. This paper presents the latest results obtained along these lines, as applied to pool-type research reactors. An effort of the recent years is to develop a research reactor which will have a broad range of experimental capabilities while being of as simple and economical design as possible. NIKIET specialists prepared a technical proposal for a reactor complex RUTA-IT, which combines various irradiation options with a capacity to make the best possible use of the emitted thermal energy. The characteristics and capabilities of this complex are described in the paper. The requirements for research reactors of a new generation are largely implemented in the MBIR reactor design that has been under development at NIKIET since 2008. This is going to be a fundamentally new fast-neutron research reactor with uranium-plutonium fuel, liquid-metal sodium coolant, and a set of loop devices for testing of experimental products. The key reactor design features are presented in the paper. The paper ends with a conclusion that the scientific community is coming to realize that research reactors are indispensable tools for innovative development of science, power engineering, technologies, and education. (authors)