Abstract :
The “Mobile fuel reactor (MFR) concept” [Slessarev, I., Stukalov,V., Subbotin, S., 1984. Problems of development of fast reactors self-fuel-provision without fuel reprocessing. Atomkernenergie, 45, N1; Slessarev, I., et al., 2004. WISE: a new fuel cycle concept based on a mobile fuel reactor. Nuclear Technol., 146 (N3), 230–243] and re-organization of the fuel cycle may allow to build the “actinide waste free” nuclear power (NP) and to improve radically its proliferation resistance. These goals can be achieved on the base of an “intrinsic approach” respecting long-lived wastes, safety and non-proliferation aspects simultaneously. It implies elimination of feed fuel enrichment, irradiated fuel reprocessing as well as the need for a long-lived, radiotoxic actinide repository. The key concept is: the application of “mobile” (liquid or gaseous) reactor fuels allowing for a simple mixing of fresh and already irradiated fuel components without “forced” FP separation.
The neutronics of the innovative nuclear reactor concept, -MFR- with mobile fuels is discussed in details. Elimination of fuel enrichment implies “natural fuel” feed with relatively low neutron balance potential, however, the neutronics has to be capable of supporting critical or near-critical regimes to be economically acceptable. Sufficient capability is achieved by utilizing a favorable, hard neutron spectrum (e.g. fast neutron spectrum of SPX-type), in addition to elongation of the fuel in-core residence time and by use of an appropriate core composition with enhanced fissile breeding. No dedicated actinide transmutation (by targets for example) is required in this system.
It is concluded that the mobile fuel reactor neutronics in the case of the once-through fuel cycle is almost acceptable to be used for future NP to be protected intrinsically against long-lived actinide wastes, weapons proliferation menace and heavy accidents.
