Thermal Energetic Reactor with High Reproduction of Fission Materials

Existing thermal reactors are energy production scale limited because of low portion of raw uranium usage. Fast reactors are limited by reprocessing need of huge mass of raw uranium at the initial stage of development. The possibility of development of thermal reactors with high fission materials reproduction, which solves the problem, is discussed here. Neutron losses are decreased, uranium-thorium fuel with artificial fission materials equilibrium regime is used, additional in-core and out-core neutron sources are used for supplying of high fission materials reproduction. Liquid salt reactors can use dynamic loading regime for this purpose. Preferable construction is channel type reactor with heavy water moderator. Good materials for fuel element shells and channel walls are zirconium alloys enriched by 90Zr. Water cooled reactors with usage 12% of raw uranium and liquid metal cooled reactors with usage 25% of raw uranium are discussed. Reactors with additional neutron sources obtain full usage of raw uranium with small additional energy expenses. On the base of thermal reactors with high fission materials reproduction world atomic power engineering development supplying higher power and requiring smaller speed of raw uranium mining, than in the variant with fast reactors, is possible. 1. Introduction According to the forecast for the end of XXI century, NPP can produce not more than 30% of total energy [1]. It is considered that the main role will be played fast reactors, which have high reproduction of fission materials and, correspondingly, less raw uranium requirement. Fast reactors need huge start expenses for fuel producing. Thermal reactors with enrichment plants will play the role of the producer of initial fission material for fast reactors [2]. These prognoses are based on characteristics of modern light water reactors, which have base niche in nuclear energy production. Advantages of these reactors are based on high-level burn-up possibilities by means of 235U enrichment increasing in fuel. But simultaneously, fission materials reproduction is decreasing. There are thermal reactors with higher fission materials reproduction [3, 4]. Works at IAE NNC RK are devoted to possibilities of its development. Features of “dynamic loading” technology, in which fuel periodically works strictly defined time (e.g., 5 hours) and after that is replaced with another fuel portion and is sustained out of core (50 hours, e.g.), were researched [5]. This technology decreases neutron losses in 135Xe due to its decay during sustaining and can be easily applied in