Minimization of reactivity margin in equilibrium cores of liquid metal cooled fast reactors

In the framework of ''Proryv'' project, not only the problem of minimization of potential nuclear accident consequences was set up, but also that of minimization of its initial cause, i.e. core reactivity margin. Minimization of the core reactivity margin is possible within the framework of so called concept of ^equilibrium reactor core (reduction of reactivity margin provided for the fuel burn-up), and also with the use of liquid metal bond high conductivity fuel elements (temperature-power effect). In the paper, ^equilibrium reactor core concept is specified and possibilities of its implementation are analyzed. Studies were made on dependence of scenarios, key design characteristics and accident consequences on the added total reactivity margin value. Advantages of low reactivity margin of about 1-2 β_eff are quantitatively demonstrated from the standpoint of nuclear safety assurance and decrease of accident consequences down to the level excluding public local evacuation and resettlement. (author)