The invention relates to a method for eliminating neutrons from fission, fusion or aneutronic nuclear reactions in a reactor, in particular in a laser-driven nuclear fusion reactor which operates with hydrogen and the boron-11 isotope, in which method at least some moderated neutrons are made to undergo a nuclear reaction with tin. As a result of the nuclear reactions with tin, the neutrons convert the tin nuclei into stable nuclei having a higher atomic weight resulting from neutron capture. The invention also relates to a reactor which is designed for energy conversion by means of fission, fusion or aneutronic nuclear reactions and for generating electric energy, wherein the reactor contains a neutron elimination device which contains tin and is arranged such that at least some moderated neutrons are made to undergo a nuclear reaction with the tin.

A neutron moderator includes a porous metal hydride with channels within the porous metal hydride. Further, a method of regenerating a neutron moderator includes providing an at least partially depleted metal hydride article and introducing a hydrogen-containing gas into the at least partially depleted metal hydride article. The at least partially depleted metal hydride article includes channels. A nuclear reactor includes one or more neutron moderator regions in a core of a reactor, one or more fuel regions adjacent to the one or more neutron moderator regions, one or more heat transfer regions adjacent to the one or more fuel regions, control drums adjacent to the core, and a control rod adjacent to the core. One or more of the neutron moderator regions include a neutron moderator comprising a porous metal hydride article that has channels.

A neutron moderator includes a porous metal hydride with channels within the porous metal hydride. Further, a method of regenerating a neutron moderator includes providing an at least partially depleted metal hydride article and introducing a hydrogen-containing gas into the at least partially depleted metal hydride article. The at least partially depleted metal hydride article includes channels. A nuclear reactor includes one or more neutron moderator regions in a core of a reactor, one or more fuel regions adjacent to the one or more neutron moderator regions, one or more heat transfer regions adjacent to the one or more fuel regions, control drums adjacent to the core, and a control rod adjacent to the core. One or more of the neutron moderator regions include a neutron moderator comprising a porous metal hydride article that has channels.

A passive nuclear reactor control device. The passive nuclear reactor control device comprises a sealed chamber, which comprises a reservoir and a tube in fluid communication with the reservoir. A molten salt is within the sealed chamber, the molten salt being a eutectic mixture of a monovalent metal halide, and a fluoride or chloride of one or more lanthanides and/or a luoride or chloride of hafnium. A gas is within the sealed chamber, and the gas does not react with the molten salt.

A method for dynamic pressure control during a multiphase injection is described wherein the pressures of fluids in the various reservoirs of a fluid delivery system are controlled to provide desired fluid delivery parameters. The methods include advancing the first drive member to expel the first fluid from the first reservoir into a conduit, wherein the fluid is pressurized to a first fluid pressure; measuring the first fluid pressure to provide a target value; while the second reservoir is in fluid isolation from the conduit, advancing or retracting the second drive member to increase or decrease the fluid pressure of the second fluid in the second reservoir to the target value; placing the second reservoir in fluid communication with the conduit; and advancing the second drive member to expel the second fluid from the second reservoir into the conduit.

A method for dynamic pressure control during a multiphase injection is described wherein the pressures of fluids in the various reservoirs of a fluid delivery system are controlled to provide desired fluid delivery parameters. The methods include advancing the first drive member to expel the first fluid from the first reservoir into a conduit, wherein the fluid is pressurized to a first fluid pressure; measuring the first fluid pressure to provide a target value; while the second reservoir is in fluid isolation from the conduit, advancing or retracting the second drive member to increase or decrease the fluid pressure of the second fluid in the second reservoir to the target value; placing the second reservoir in fluid communication with the conduit; and advancing the second drive member to expel the second fluid from the second reservoir into the conduit.

A stationary control rod that controls overall nuclear reactivity and axial reactivity distribution of a fuel assembly, such that power level and axial power distribution within the fuel assembly is controlled without the need for movable control rods and associated hardware. The device uses magnetic fields to control the concentration and distribution of a magneto-rheological fluid containing a material with a very high neutron capture cross section, contained in one or more enclosed thimbles placed within existing thimbles in a fuel assembly. The magnetic fields are generated from electricity produced from interactions of the radiation particles within the core, or supplied using electrical cables that attach to fuel assembly top nozzles. The electricity drives a device that encloses associated wire coil assemblies that surround different axial regions of a tube that contains the magneto-rheological fluid.

A stationary control rod that controls overall nuclear reactivity and axial reactivity distribution of a fuel assembly, such that power level and axial power distribution within the fuel assembly is controlled without the need for movable control rods and associated hardware. The device uses magnetic fields to control the concentration and distribution of a magneto-rheological fluid containing a material with a very high neutron capture cross section, contained in one or more enclosed thimbles placed within existing thimbles in a fuel assembly. The magnetic fields are generated from electricity produced from interactions of the radiation particles within the core, or supplied using electrical cables that attach to fuel assembly top nozzles. The electricity drives a device that encloses associated wire coil assemblies that surround different axial regions of a tube that contains the magneto-rheological fluid.

A nuclear power system includes a reactor vessel that includes a reactor core mounted within a volume of the reactor vessel. The reactor core includes one or more nuclear fuel assemblies configured to generate a nuclear fission reaction. The nuclear power system further includes a containment vessel sized to enclose the reactor vessel such that an open volume is defined between the containment vessel and the reactor vessel. A boron injection system is positioned in the open volume of the containment vessel and includes an amount of boron sufficient to stop the nuclear fission reaction or maintain the nuclear fission reaction at a sub-critical state. The boron injection system is positioned to deliver the amount of boron into the open volume.

A nuclear reactor system includes a nuclear reactor core disposed in a pressure vessel. Nuclear reactor system further includes control drums disposed longitudinally within the pressure vessel and laterally surrounding fuel elements and at least one moderator element of the nuclear reactor core to control reactivity. Each of the control drums includes a reflector material and an absorber material. Nuclear reactor system further includes an automatic shutdown controller and an electrical drive mechanism coupled to rotatably control the control drum. Automatic shutdown controller includes a counterweight to impart a bias and an actuator. To automatically shut down the nuclear reactor core during a loss or interruption of electrical power from a power source to the electrical drive mechanism, the actuator is coupled to the counterweight and responsive to the bias to align the absorber material of one or more control drums to face inwards towards the nuclear reactor core.