On Self-Adjustable Neutron-Nuclear Modes in Fast Critical and Hybrid Reactors

The opportunities of use in a fast reactor of such a mode, at which Pu²³⁹ formation and its burning out compensate each other are investigated. Thus the reactor comes to a self-adjustable neutron-nuclear mode (SANN) and is automatically supported in a condition close to critical. For the process analysis the direct study of SANN without control is necessary. In real reactor SANN should be used together with control and together with processes ensuring a transition in subcriticality at overheating. Control proves to be much less, than in usual reactor. In result there is a number of advantages: the operating time is determined by deterioration of shells of fuel elements, the control failure does not result in failures, the mechanisms of protection work more reliably. In the variant of hybrid reactor control is possible at the expense of insignificant change the neutron source power. In reactor at SANN actually burns cheap U²³⁸. It allows to lower energy release density and to raise reactor safety. The organization of the closed fuel cycle and ensuring of non-proliferation of the nuclear weapon are possible. (author)