In recent years, small power modular reactors (SMRs) have begun to be developed in many countries around the world. At the last IAEA meeting of Technical Working Group on Fast SMRs (September, 2019), several concepts for SMRs with different coolants were presented. Interest in such reactors is due to a number of their inherent features: reducing the construction term, a higher level of safety, a longer campaign without refueling etc.).
The main difficulty to be overcome is the increase in specific capital costs while reducing the capacity of the reactor module. This limits the market niche of such reactors to regions with a high cost of fossil fuel. The noted difficulty increases with the use of SMRs and for heat supply, which requires the placement of such NPPs at a short distance from heat consumers and necessitates an increase in NPP safety. The safety level of a reactor is largely determined by the potential energy accumulated in the reactor coolant. The release of this energy in case of violation of normal operating conditions can lead to a large release of radioactivity, the localization of which requires an increase in the number of protective barriers and their effectiveness. This causes an increase in the cost of the NPP and a decrease of competitiveness.
The report analyzes the properties of various coolants and their effect on the internal self-protection of the reactor, its safety and economy, their advantages and disadvantages. Therefore, the choice of a coolant is always a compromise solution.
Taking into account the results of the analysis performed, the choice of chemically inert heavy liquid-metal coolants with a very high boiling point the lead-bismuth eutectic (LBE) and lead - was substantiated for fast SMRs, and among them, in favor of the LBE, taking into account its mastering in the operating conditions of ship reactors, a practical solution to the problem of ensuring radiation safety associated with the formation of polonium, a significantly lower melting point, which simplifies operation, and the possibility of "freezing-defreezing" of the coolant in the reactor. It permits to realize of the SVBR-100 reactor, which is being developed within the framework of a state-private partnership, with minimal investment risk.
|Country/Int. organization||Russian Federation|
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