25results about "Fast fission reactors" patented technology

Fuel bundle has plurality of twisted ribbon fuel rodlets in hexagonal packing or circle packing arrangement in a core region encased in a multilayer casing. Arrangement of twisted ribbon fuel rodlets is facilitated by rodlet seating fixture with seating surface having a plurality of protrusions that form a receiving space for ends of the twisted ribbon fuel rodlets. Manufacture of the fuel bundle incorporates fiber manufacturing technologies and, optionally, infiltration of void spaces in core region by infiltrant. Twisted ribbon fuel rodlet manufacturing system has sub-systems that impart twist periodicity to extruded ribbons, inspect twisted extruded ribbons, and cut twisted extruded ribbons to length. Inspection sorts twisted ribbon fuel rodlets as well as provides feedback to adjust operation of sub-systems. The fuel bundle (and optional fuel bundle support) can be incorporated into a fuel assembly of a nuclear propulsion fission reactor structure of, for example, a nuclear thermal propulsion engine.

Heat pipe fuel element includes an evaporation section, a condensing section, a capillary section connecting the evaporation section to the condensing section, and a primary coolant. In a cross-section in a plane perpendicular to a longitudinal axis of the evaporation section, the heat pipe fuel element includes a cladding layer enclosing an interior area including a fuel body formed of a fissionable fuel composition and that has an outer surface oriented toward the cladding layer and an inner surface defining a periphery of a vaporization space of the evaporation section. The fuel body has a structure with a shape corresponding to a mathematically-based periodic solid, such as a triply periodic minimal surface (TPMS), and the evaporation sections of a plurality of heat pipe fuel elements are arranged in a phyllotaxis pattern (as seen in a cross-section in a plane perpendicular to a longitudinal axis of the active core region).

A fuel assembly for use in a nuclear reactor comprising a fuel bundle, a plenum header connection positioned on the fuel bundle, a mast extending from the fuel bundle, and a common fission gas plenum extending from the mast is disclosed. The reactor includes a vessel and coolant situated within the vessel. The fuel bundle comprises a plurality of fuel elements including nuclear fuel material positioned therein. The plenum header connection comprises a plurality of passageways defined therein that are in fluid communication with the nuclear fuel material. The elongate mast comprises an internal passage connecting the common fission gas plenum to the plurality of passageways of the plenum header connection such that the common fission gas plenum is configured to receive an amount of fission gas generated by the nuclear fuel material during operation. The common fission gas plenum is positioned in an otherwise unused portion of the vessel.

The invention relates to a fast-neutron nuclear reactor (1), which comprises: - a reactor vessel (10) filled with a heat-transfer fluid, - a reactor core (11) consisting of fuel assemblies (13), - a reactivity control system (2), at the periphery of the core, in a cold plenum zone or in the hot plenum, between the reactor vessel and the separation step between the hot and cold plenums, such that the cold heat-transfer fluid passes through the assemblies or monolithic reactivity control rods.

A fast neutron nuclear reactor, in particular liquid-metal cooled, with a reactivity control system arranged on the periphery of the nuclear core. The invention relates to a fast neutron nuclear reactor (1) comprising: - a reactor vessel (10) filled with a coolant, - a reactor core (11) consisting of fuel assemblies (13), - a reactivity control system (2), on the periphery of the core, in a cold manifold zone, between the reactor vessel and the separation step between the hot and cold manifolds, such that the reactivity control assemblies or monoblock rods are traversed by the cold coolant. Figure for the abstract: Fig. 2

The present invention is directed to a fission product extraction system operable to capture and extract fission products from a flow of irradiated fueled molten salt of a molten salt reactor. The example extraction systems described herein utilize electroless deposition to chemically plate fission products onto a metallic structure. The metallic structure may be partially coated with a reducing agent, such as beryllium to provide an electron source for the fission products. The metallic structure may be a component of an extraction system designed to facilitate submersion of the metallic structure into the flow of molten salt. The extraction system may also be designed to facilitate removal of the metallic structure without requiring a shut down or slowdown of the reactor system.

The embodiment of the application relates to the technical field of the layout of a nuclear power plant, and particularly relates to a layout structure for a lead-bismuth subcritical fast reactor reactor plant, which comprises a reactor body module, a primary loop auxiliary system module, a secondary loop system module, a tertiary loop system module, an accident residual heat removal module, an electrical and instrumentation equipment module, a fuel processing module, and an auxiliary supporting facility, and specific arrangement modes of the modules are given. According to the layout structure provided by the embodiment of the application, the compact layout of the lead-bismuth subcritical fast reactor reactor plant is realized, the rationality and economy of the layout of the lead-bismuth subcritical fast reactor reactor plant are improved, and the production construction cost is reduced.

Disclosed herein is a nuclear reactor system comprising a vessel encompassing a reactor core. An external loop line is connected to top and bottom portions of the vessel. A pump can circulate molten fuel through the reactor core and the external loop line. An external neutron reflector encompasses the vessel. External heaters heat the loop line and the reflector. The loop line, the reactor, or both, may be covered with insulation.

Reactivity control system for a rotating non-fuel assembly nuclear reactor, at the periphery of the core. The invention relates to a reactivity control system (2) for a fast neutron nuclear reactor comprising at least one subassembly including: - a non-fuel assembly (200) of generally cylindrical shape, comprising a plurality of needles or rods (201) of neutron-absorbing material, and a plurality of needles or rods (202) of neutron-reflecting material, arranged parallel to the needles or rods of neutron-absorbing material, - a system (22) for rotating the non-fuel assembly about its axis. Figure for the abstract: Fig. 3

Fuel bundle has plurality of twisted ribbon fuel rodlets in hexagonal packing or circle packing arrangement in a core region encased in a multilayer casing. Arrangement of twisted ribbon fuel rodlets is facilitated by rodlet seating fixture with seating surface having a plurality of protrusions that form a receiving space for ends of the twisted ribbon fuel rodlets. Manufacture of the fuel bundle incorporates fiber manufacturing technologies and, optionally, infiltration of void spaces in core region by infiltrant. Twisted ribbon fuel rodlet manufacturing system has sub-systems that impart twist periodicity to extruded ribbons, inspect twisted extruded ribbons, and cut twisted extruded ribbons to length. Inspection sorts twisted ribbon fuel rodlets as well as provides feedback to adjust operation of sub-systems. The fuel bundle (and optional fuel bundle support) can be incorporated into a fuel assembly of a nuclear propulsion fission reactor structure of, for example, a nuclear thermal propulsion engine.

This description relates to a method (300) for determining, by a computing device, a fuel salt composition of a molten salt nuclear reactor, the method comprising: - the determination of neutron fluxes (ϕ(E)) of several energies and a multiplication factor by a step of solving (302) a neutron transport equation; - the determination, for each of the nuclides, of condensed microscopic cross sections from the neutron fluxes (ϕ(E)); - the determination (303) of the weights of the nuclides on the multiplication factor from the condensed microscopic cross sections; and - the determination (304), from the weights of the nuclides, of a fuel salt inventory including at least one calculation of the evolution of the nuclides, by a step of solving (306) evolution equations, such that the evolution inventory complies with at least one operating condition.

To provide a reactor core of a fast reactor, which flattens an output distribution and increases an outlet temperature of coolant while suppressing the deterioration in reactor performance, so as to be able to achieve a sodium-cooled metal fuel fast reactor with high compatibility with a molten salt thermal storage system.SOLUTION: A reactor core 1 of a fast reactor is such a fuel assembly that fuel rods each formed by storing hollow fuels with a predetermined enrichment degree within a range of 11 to 13 wt.% in cladding tubes are densely arranged in a wrapper tube. A first fuel assembly 2 having the fuel rods with the hollow fuels of a large hollow diameter is loaded at the center of the core and a second fuel assembly 3 having the fuel rods with the hollow fuels having a hollow diameter smaller than that of the hollow fuels of the first fuel assembly 2 is loaded at a periphery of the core.SELECTED DRAWING: Figure 1

An anti-proliferation technique is disclosed to reduce the likelihood of nuclear proliferation due to the use fissionable fuel salts. The technique includes doping the fuel salt with one or more elements (referred to herein as activation dopants) that, upon exposure to neutrons such as would occur in the fuel salt when a reactor is in operation, undergo a nuclear reaction to, directly or indirectly, form highly active “protecting isotopes” (of the same element as the activation dopant or a different element). A sufficient mass of activation dopants is used so that the Figure of Merit (FOM) of the fuel salt is decreased to below 1.0 within some target number of days of fission. This allows the FOM of the fuel salt to be controlled so that the fuel becomes too dangerous to handle before to the creation of a significant amount of weaponizable isotopes.

Fuel assembly for a nuclear reactor, of the Na-NFR type, without a casing, comprising a bundle of fuel needles held laterally by perforated grids and longitudinally by stiffening rods passing through the grids. The invention essentially consists of a fuel assembly (1) of hexagonal or parallelepiped cross-section without a hexagonal tube casing, preferably intended for low-power-volume liquid sodium-cooled fast reactors (Na-NFRs). Figure for the abstract: Fig. 5

This installation method is a method for installing a reactor structure of a fast reactor (S100), the fast reactor (S100) comprising: a large rotation plug (14); a small rotation plug (15); an upper core mechanism (30) provided with a plurality of control rod drive mechanisms (40); a strongback (17); and a plurality of control rod assemblies (27) arranged among a group of core components inserted into a diagrid (18), the plurality of control rod drive mechanisms (40) being provided in an arrangement corresponding to the plurality of control rod assemblies (27) and moving the control rods (27 a) of the control rod assemblies (27) up and down individually, and includes an adjustment step of rotating the large rotation plug (14), the small rotation plug (15), and the upper core mechanism (30) to move the control rod drive mechanisms (40) so that each control rod drive mechanism (40) is positioned above the control rod assembly (27) corresponding to the control rod drive mechanism (40).

Nuclear reactor systems and associated devices and methods are described herein. A representative nuclear reactor system includes a heat pipe network having an evaporator region, an adiabatic region, and a condenser region. The heat pipe network can define a plurality of flow paths having an increasing cross-sectional flow area in a direction from the evaporator region toward the condenser region. The system can further include nuclear fuel thermally coupled to at least a portion of the evaporator region. The heat pipe network is positioned to transfer heat received from the fuel at the evaporator region, to the condenser region. The system can further include one or more heat exchangers thermally coupled to the evaporator region for transporting the heat out of the system for use in one or more processes, such as generating electricity.

The invention relates to a nuclear reactor (1) having solid fuel assemblies (2) that are sealed and cooled individually in nominal operation by heat pipes (23). The invention substantially consists of a nuclear reactor (1) that operates in the fast neutron spectrum and is cooled by an array of one or more heat pipes (23). At least part of the evaporator (231) of one or more heat pipe(s) (23) is held and partially housed with one or more rods (22) of solid fuel pellets which are enclosed in a sheath in a sealed assembly which is partially filled with a liquid metal bath (21), which can be defined as a thermal seal between the rod sheaths and the heat pipes (23). The core (11) of the reactor (1) consists of an array of these sealed assemblies (2) (fuel rod(s) and heat pipe(s) immersed in a liquid metal bath) arranged within a tank (10) surrounded by a neutron reflector (12).

A thermal energy storage system is provided that is connected to both the nuclear reactor and the generator. [Solution] The integrated energy system includes a nuclear heat plant located on the reactor site. The nuclear heat plant produces thermal energy that is transported to a thermal energy storage system located outside the reactor site. The thermal storage system is thermally coupled to a power generation system that is also remote from the reactor site. This arrangement isolates and decouples the nuclear heat plant from the power generation system. The nuclear heat plant can provide thermal energy above 800°C that is stored in the thermal energy storage system until needed, such as for industrial heat, the power generation system, or other uses. The thermal storage system is source-forgiving, allowing one or more additional thermal energy generators, such as additional nuclear reactors, solar thermal plants, or other thermal energy generators, to be coupled to the common thermal storage system and power generation system.

An integral molten salt nuclear reactor includes a drain tank section configured to hold a volume of fuel salt. The integral molten salt nuclear reactor further includes a reactor section configured to receive the volume of fuel salt from the drain tank and cause fission reactions that heats the molten salt. The integral molten salt nuclear reactor further includes a heat exchange section configured to receive a flow of the heated fuel salt from the reactor section and remove heat therefrom.

A molten salt nuclear reactor of the fast neutron type, with a vessel filled with inert liquid salts surrounding the reactor vessel as a residual heat removal (RHR) system. The invention essentially consists of constructing a molten salt nuclear reactor of the fast neutron type, the architecture of which includes a reactor vessel free of a moderator, or at least lacking a moderator that would allow the reactor to be classified as a thermal neutron reactor. This vessel is axisymmetric in shape and surrounded by another vessel at the periphery of the reactor vessel, which defines an inter-vessel space filled with an inert liquid salt that serves as a heat transfer fluid for the removal of the reactor's residual heat by conduction through the reactor vessel. Figure for the abstract: Fig. 3

The invention consists essentially of a fuel assembly (1) of hexagonal or parallelepiped cross-section, without a hexagonal duct, preferably intended for low-power-density sodium-cooled fast neutron reactors (SFR).

A nuclear reactor includes a vessel (2) internally defining a pool (3), a cooling fluid (CF) in the pool (3), and a core (6) housed in the vessel (2) and comprising a plurality of fuel elements (8) at least partially immersed in the cooling fluid (CF) and extending along respective longitudinal axes (A). For each fuel element (8), the nuclear reactor is provided with respective reversible locking members (17), configured to axially constrain adjacent fuel elements (8) to one another and to axially constrain the outermost fuel elements directly or indirectly to the vessel (2), so as to prevent the extraction of the constrained fuel elements (8). The nuclear reactor is further provided with axial adjustment devices (30, 40) configured to adjust an axial distance between respective fuel elements (8) and the respective locking members (17).

A containment system for an integral molten salt reactor includes a sealed containment structure defining a containment volume. The containment structure includes a fission product adsorbing / absorbing material. The containment system further includes an integral molten salt reactor housed fully within the containment volume of the sealed containment structure. The integral molten salt reactor may permit circulation of a fuel salt therein being heated by fission reactions, and allow for the export of heat from said fuel salt.