Analysis of attractiveness of nuclear materials as applied to the on-site fuel cycle of naturally safe BR-1200 fast reactors
By now, a fairly stable concept of «attractiveness of nuclear materials» has been formed in scientific literature. This term implies that nuclear materials which are in the civil fuel cycle may be used for making primitive nuclear explosive devices or even nuclear weapon. This concept serves as a comparative analysis of various nuclear materials for their possible unauthorized application. Attractiveness of nuclear materials is primarily defined by their nuclear physical properties, i.e., properties inherent in these materials. First of all, these properties include the capability of the considered material to produce a self-sustaining chain reaction. Otherwise, this material will be absolutely unattractive for the above-mentioned purposes. Besides this main property, important characteristics of nuclear materials influencing their attractiveness are the neutron background and heat emission. This paper presents an analysis of fuel compositions in the fuel cycle of naturally safe BR-1200 fast reactors (BREST-1200) with an on-site NFC infrastructure in terms of their attractiveness. The objects of research are the elementary systems in the form of spheres containing nuclear materials of the BR-1200 fast reactor fuel cycle without neutron reflectors and surrounded with such reflectors made from various materials. At the same time, for each system its critical state is defined and the main properties characterizing the attractiveness of nuclear materials are calculated, taking into account materials and thicknesses of the neutron reflectors.