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.
G21C 3/54 - Fused salt, oxide, or hydroxide compositions
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/14 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor
G21C 7/02 - Control of nuclear reaction by using self-regulating properties of reactor materials
G21C 7/04 - Control of nuclear reaction by using self-regulating properties of reactor materials of burnable poisons
G21C 7/22 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of a fluid or fluent neutron-absorbing material
G21C 7/24 - Selection of substances for use as neutron-absorbing material
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
G21C 19/31 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products specially adapted for liquids for molten metals
A heat exchanger. The heat exchanger comprises a plurality of primary fluid tubes configured to carry a primary fluid, a plurality of secondary fluid tubes configured to carry a secondary fluid, and a plurality of intervening layers, each intervening layer being thermally conductive and impermeable to both the primary and secondary fluids. Each intervening layer has one or more of the primary fluid tubes on a first side, and one or more of the secondary fluid tubes on a second side opposite the first side, such that the region between each pair of neighbouring intervening layers contains either primary fluid tubes or secondary fluid tubes, but not both primary and secondary fluid tubes.
F22B 1/06 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being moltenUse of molten metal, e.g. zinc, as heat transfer medium
Use of a molten salt comprising aluminium trifluoride and sodium fluoride as a primary coolant for a fission reactor, wherein the molten salt is in contact with graphite and with aluminium metal during operation of the fission reactor.
G21C 1/22 - Heterogeneous reactors, i.e. in which fuel and moderator are separated using liquid or gaseous fuel
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/16 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor moderator and coolant being different or separated, e.g. sodium-graphite reactor
G21C 3/54 - Fused salt, oxide, or hydroxide compositions
4.
CONTROL OF NOBLE GAS BUBBLE FORMATION IN A MOLTEN SALT REACTOR
A molten salt fission reactor. The reactor comprises a reactor core, which comprises a plurality of fuel tubes. Each fuel tube contains a fuel salt and a gas interface. The fuel salt is a molten salt of one or more fissile isotopes. The gas interface is a surface of the fuel salt in contact with a gas space during operation of the reactor. The reactor also comprises a fuel salt cooling system, which is configured to cool the fuel salt. The cooling system comprises a heat exchanger and a coolant tank. The coolant tank contains a coolant liquid in which the fuel tubes are at least partially immersed. The heat exchanger is for extracting heat from the coolant liquid. The fuel salt cooling system is configured such that during operation of the reactor, for all points within the fuel salt within each fuel tube except at the respective gas interface: (I)
A method of reprocessing spent nuclear fuel. The spent nuclear fuel is added to an electro-reduction cell, wherein the electro-reduction cell comprises a halide salt electrolyte, and anode, and a cathode comprising an alloy of uranium and a first metal forming a low melting point alloy with uranium, the first metal being one or more of: iron; chromium; nickel; manganese; and cobalt. The spent nuclear fuel is electrochemically reduced at a potential sufficient to reduce plutonium and lanthanides in the spent nuclear fuel, in order to form a molten alloy of the first metal, uranium and higher actinides present in the spent nuclear fuel. The alloy is extracted from the electro-reduction cell while uranium oxide is still present in the electro-reduction cell. The spent nuclear fuel comprises uranium oxide and at least 1 mol of lanthanides per tonne of uranium in the spent nuclear fuel, and the electro- reduction cell is operated at a temperature above the melting point of the alloy.
There is described a method of reprocessing spent nuclear fuel. The spent nuclear fuel is added to an electro-reduction cell containing a halide salt electrolyte at a temperature above the melting point of the metallic form of uranium and higher actinides present in the spent nuclear fuel. The cell is operated so as to electrochemically reduce the spent nuclear fuel to form an alloy of uranium and higher actinides present in the spent nuclear fuel, wherein electrochemical reduction is continued until a concentration of unreduced components of the spent nuclear fuel is sufficiently low for the alloy to agglomerate.
Methods of controlling the reactivity of a molten salt fission reactor. The molten salt fission reactor comprises a core and a coolant tank, the core comprising fuel tubes containing a molten salt fissile fuel, and the coolant tank containing a molten salt coolant, wherein the fuel tubes are immersed in the coolant tank. The methods comprise dissolving a neutron absorbing compound in the molten salt coolant, the neutron absorbing compound comprising a halogen and a neutron absorbing element. The methods further comprise reducing the neutron absorbing compound to a salt of the halogen and an insoluble substance comprising the neutron absorbing element, the halogen being fluorine or chlorine, wherein the insoluble substance is not volatile at a temperature of the coolant during operation of the reactor. The reduction may be by addition of a reducing compound, or by electrochemical reduction. Apparatus for implementing the methods are also provided.
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/14 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor
G21C 7/04 - Control of nuclear reaction by using self-regulating properties of reactor materials of burnable poisons
G21C 19/31 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products specially adapted for liquids for molten metals
Use in a nuclear fission reactor of a sacrificial metal in a molten salt fuel containing actinide halides in order to maintain a predefined ratio of actinide trihalide to actinide tetrahalide without reducing actinide trihalide to actinide metal. A method of maintaining oxidation state of a molten salt containing actinide halides. The method comprises contacting the molten salt continuously with a sacrificial metal, the sacrificial metal being selected in order to maintain a predefmed ratio of actinide trihalide to actincide tetrahalide without reducing actinide trihalide to actinide metal. A fuel tube containing a sacrificial metal is also described
G21C 3/54 - Fused salt, oxide, or hydroxide compositions
G21C 3/16 - Details of the construction within the casing
G21C 19/28 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core
G21C 19/31 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products specially adapted for liquids for molten metals
A nuclear fission reactor comprising a core, a pool of coolant liquid, and a heat exchanger. The core comprises an array of hollow tubes which contain molten salts of fissile isotopes. The tube array is at least partly immersed in the pool of coolant liquid. The tube array comprises a critical region, where the density of the fissile isotopes during operation of the reactor is sufficient to cause a self-sustaining fission reaction. Heat transfer from the molten salts of fissile isotopes to the tubes is achieved by any one or more of natural convection of the molten salts, mechanical stirring of the molten salts, and oscillating fuel salt flow within the tubes. The molten salts of fissile isotopes are contained entirely within the tubes during operation of the reactor.
patents