Analysis of system characteristics of a reactor with supercritical coolant parameters

Abstract

For 60 years of its existence, nuclear energy has passed the first stage of its development and has proven that it can become a powerful industry, going beyond the 10% level in the global balance of energy production. Despite this, modern nuclear industry is capable of producing economically acceptable energy only from uranium-235 or plutonium, obtained as a by-product of the use of low enriched uranium for energy production or surplus weapons-grade plutonium. In this case, nuclear energy cannot claim to be a technology that can solve the problems of energy security and sustainable development, since it meets the same economic and ‘geological’ problems as other technologies do, based on the use of exhaustible organic resources. The solution to this problem will require a new generation of reactors to drastically improve fuel-use characteristics. In particular, reactors based on the use of water cooling technology should significantly increase the efficiency of using U-238 in order to reduce the need for natural uranium in a nuclear energy system. To achieve this goal, it will be necessary to transit to a closed nuclear fuel cycle and, therefore, to improve the performance of a light-water reactor system. The paper considers the possibility of using a reactor with a fast-resonance neutron spectrum cooled by supercritical water (SCWR). The SCWR can be effectively used in a closed nuclear fuel cycle, since it makes it possible to use spent fuel and discharge uranium with a small amount of plutonium added. The authors discuss the selected layout of the core with a change in its size as well as the size of the breeding regions (blankets). MOX fuel with an isotopic plutonium content corresponding to that discharged from the VVER-1000 reactor is considered as fuel. For the selected layout, a study was made of the reactor system features. Compared with existing light-water reactors, this reactor type has increased fuel consumption due to its improved efficiency and nuclear fuel breeding rate up to 1 and above.