85results about "Subcritical reactors" patented technology

A process incinerate transuranic chemical elements and nuclear reactor implement this process. In order to incinerate transuranic chemical elements, such as long-lived nuclear waste and plutonium, a nuclear reactor is used in which the core operates at a low level of sub-criticality. This level is chosen substantially equal to the difference βs between a desired fraction βt of delayed neutrons in the core and the real fraction β. An external source of spallation neutrons includes a proton accelerator in which one adjusts the power, in real time, on the neutron flux measured in the core. A supplementary fraction of delayed neutrons equal to the difference βs is thus injected into the reactor core. The reactor then behaves and controls itself like a classical critical reactor.

A combinatorial heterogeneous-homogeneous reactor configuration in which an array or groups of homogeneous fuel assemblies are interlinked together in a heterogeneous lattice. The present invention removes the limitation of a homogeneous reactor by providing a reactor concept that utilizes the inherent advantages of homogeneous fuel elements but in a heterogeneous fuel lattice arrangement that limits the power density of any one homogeneous fuel element and yet forms a reactor arrangement that is capable of producing any product demand of interest. The present invention provides a method for producing medical isotopes by the use of a modular reactor core comprised of homogeneous fuel assemblies arranged in a regular rectangular or triangular pitch lattice. The aqueous fuel solution is contained within individual fuel assemblies that are right circular cylinders clad in corrosion-resistant alloys such as stainless steel, zircalloy, zircalloy alloys, or other metal alloys that are resistant to corrosive fissile environments but preserve neutron economy. The fuel assemblies are supported below by a core plate that is tied directly to the lower reactor support structure. The bottom of each assembly opens into a common plenum area which provides a hydrodynamic communication / coupling path between the individual assemblies in the lattice. The fuel assemblies are supported above by an upper plate that is welded to each assembly tube. The top of each assembly opens to a common upper plenum which provides a means of thermodynamic pressure equalization among the four assemblies in the reactor core lattice.