[en] A nuclear reactor design with intrinsic safety, employing the principle of accumulation with automatically maintained critical state, is proposed. The absence of control rods, a homogeneous active zone and low neutron escape create most favourable conditions for neutron balance and allow high values of the conversion factor and degree of burnup to be attained. The design ensures that critical state is not exceeded even in an emergency situation (loss of heat carrier, destruction of reactor building, etc). (Author)