199results about "Fast fission reactors" patented technology

The invention relates to the technical field of lead-based stacks, in particular to a nuclear storage integrated lead-based stack with a load autonomous following function. The nuclear storage integrated lead-based reactor with the automatic load following function comprises a reactor core, a phase change energy storage device and a heat energy utilization device, the reactor core is used for heating a coolant; the heat energy utilization device is used for absorbing heat in the coolant; the phase change energy storage device is arranged on the inlet side of the reactor core, the phase change energy storage device is used for carrying out heat interaction with a coolant, and the phase change temperature of the phase change energy storage device is consistent with the preset inlet temperature of the reactor core. According to the nuclear storage integrated lead-based reactor with the automatic load following function, natural circulation flow is not prone to oscillation and diffusion, the risk of overheating melting of the fuel assembly is not prone to occurring, thermal fatigue of the structural assembly is not prone to occurring, and high safety performance is achieved.

A mixed-spectrum molten-salt reactor has a primary containment vessel. A reactor core is housed in the primary containment vessel, the reactor core has an atypical geometry that holds a fuel salt. A blanket region is formed within the primary containment vessel and surrounding the reactor core, the blanket region comprises a blanket salt.

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.

A fast neutron nuclear reactor contains a nuclear reactor core having an array of device locations. Some device locations in the nuclear reactor core contain fissile and fertile nuclear fuel assembly devices. One or more other device locations in the nuclear reactor core contain Doppler reactivity augmentation devices that amplify the negativity of the Doppler reactivity coefficient within the nuclear reactor core. In some implementations, a Doppler reactivity augmentation device can also reduce the coolant temperature coefficient within the nuclear reactor core. Accordingly, a Doppler reactivity augmentation device contributes to a more stable nuclear reactor core.

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.

The present invention relates to a reactor construction comprising an upper compartment above a reactor compartment, said reactor compartment being separated from the upper compartment by a radiation shield, wherein a molten salt reactor (MSR) is situated in the reactor compartment, the MSR comprising a reactor vessel with a reactor vessel lid assembly comprising a reactor vessel lid shield and a reactor vessel lid wherein a lifting element is situated in the reactor construction, the lifting element comprising: at least one bar being substantially vertical and axially adjustable along its longitudinal axis by a drive mechanism situated in the upper compartment, and wherein at least one through-hole for the at least one bar is provided in the radiation shield and wherein the reactor vessel lid shield has at least one receiving structure configured to engage with and lock to the at least one bar. The invention also relates to a method of performing a maintenance operation in the reactor compartment and a power barge comprising at least one reactor construction.

An extraction system includes an absorbent framework configured to withstand the harsh environment of a molten salt reactor system and capture fission products found in the molten salt of such systems. The extraction system further includes means for removing the absorbent framework from the flow of molten salt, such that the absorbent framework may be processed to harvest the fission products. The absorbent framework may include a temperature resistant cartridge configured to house an absorbent composition. The present invention contemplates multiple absorbent compositions including metal-organic frameworks with unique structures to provide thermal stability, carbon nanotubes, and absorbent microspheres. The metal-organic frameworks may be synthesized by a variety of techniques to impart particular characteristics advantageous for use in a molten salt reactor system.

To remove decay heat, and to prevent air and liquid metal from coming into contact with each other also in the event of double breakdown of a nuclear reactor vessel and a reactor containment vessel, and prevent occurrence of a fire disaster.SOLUTION: A nuclear reactor cooling system includes: a reactor core installed in a nuclear reactor vessel; a nuclear reactor cooling material filled in the nuclear reactor vessel; a reactor containment vessel containing the nuclear reactor vessel; a concrete silo housing the reactor containment vessel; a collector cylinder forming an air upflow passage and an air downflow passage in a space between the reactor containment vessel and the concrete silo, wherein air for cooling the reactor containment vessel, whose temperature has risen to a high temperature due to heat from the reactor containment vessel, flows upward and passes through the air upflow passage, and wherein ambient air descends, passes and is led to the air upflow passage in the air downflow passage communicating with the air upflow passage; a thermal insulation material installed so as to be in contact with an exterior side of the collector cylinder in a radial direction; and a liquid nitrogen supply system which is installed at an upper part of the concrete silo in order to supply liquid nitrogen to the air upflow passage and the air downflow passage.SELECTED DRAWING: Figure 2

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.

Molten salt nuclear fission reactor comprising a core through which a fuel salt flows, means (30, 31) for circulating the fuel salt, a primary heat exchanger through which a heat-transfer salt flows, a primary enclosure which is impermeable to liquid salts and contains the reactor core, and a shelter. The reactor comprises a parallelepiped matrix (10) comprising alternating layers (11) of fuel salt channels, and layers (12) of heat-transfer salt channels. The matrix forms both the reactor core, in which the fission occurs, and the primary heat exchanger of the reactor. The means for circulating the fuel salt are entirely located within the primary enclosure and are configured to extract the fuel salt from one portion of the fuel salt channels on one side of the matrix and to propel the fuel salt into the other portion of the channels on the same side of the matrix.

A masking element with an opening is disposed on the side of a core support structure. A flow stack wall defines a plurality of inlets. At least one inlet aligns with the masking element opening when the flow stack is mated with the masking element. A flow control assembly within the flow stack is configured to restrict flow of fluid within the flow stack.

A nuclear reactor (1) comprises: a vessel (2) closed at the top by a cap (3) and containing a core (4) comprising a bundle of fuel elements (5) and immersed in a primary fluid (F) for cooling the core (4); and a heat exchanger (40) for removing heat from the primary fluid (F) by means of a secondary fluid circulating in the heat exchanger (40); the core (4) is supported by a lower support (90) supporting a lower portion of the core (4) below the active zone of the fuel elements (5) and an upper support (80) supporting an upper portion of the core (4) above the active zone of the fuel elements (5); the upper support (80) is joined to the top cover (3) by a support structure (6) extending from the top cover (3) and has an end element (16) which is open centrally and internally provided with a plurality of clamping elements (14) for vertically supporting and resiliently radially constraining the fuel element (5).

A nuclear reactor is designed to couple the load path of the control elements with the reactor core, thus reducing the opportunity for differential movement between the control elements and the reactor core. A cartridge core barrel can be fabricated in a manufacturing facility to include the reactor core, control element supports, and control element drive system. The cartridge core barrel can be mounted to a reactor vessel head. Thus, any movement, such as through seismic forces, transmits an equal direction and magnitude to the control elements and the reactor core. This arrangement reduces the opportunity for differential movement between the control elements and the reactor core.

A liquid metal cooled nuclear reactor includes a passive decay heat removal system having thermal insulation attached to a wall of a cold source reservoir that holds a phase change material, where the insulation is arranged to automatically fall by gravity from the wall in response to the wall reaching a predetermined temperature. The nuclear reactor may be a fast neutron reactor that incorporates an integral system having a final cold source with a reservoir incorporating an integral exchanger divided into a plurality of parallel tubes between which a phase change material is inserted, the reservoir being surrounded by a thermal insulating layer that can be detached in a passive manner in the event of reaching a predetermined threshold temperature.

A molten salt reactor system includes a fluid level control system configured to circulate a molten salt through a molten salt loop including an experimental tank, a sump tank, and a drain tank. The fluid level control system further includes a plurality of level sensors, pressure transducers, and electronic pressure regulators fluidically coupled with the fuel salt system. The fluid level control system is configured to receive cover gas pressures in the headspaces of the tanks and calculate target fluid height setpoints for each of the tanks. The fluid level control system further invokes the electronic pressure regulator to iteratively adjust the cover gas pressures of the tanks to achieve and maintain a target fluid level in the experimental tank.

A curvilinear electromagnetic pump is configured to follow a curve, such as by joining together multiple linear pump segments offset at an angle relative to one another. A curvilinear electromagnetic pump can be curved in two dimensions or in three dimensions. A curvilinear electromagnetic pump allows for more efficient placement of components and systems within a reactor vessel, significantly reducing the height of the reactor vessel compared to vertically positioned linear pumps. A curvilinear electromagnetic pump can follow the curvature of the reactor vessel wall and can be positioned generally near the bottom of the reactor vessel.

The reactor is designed to couple the load paths of the control elements with the core, thereby reducing the possibility of differential motion between the control elements and the core. A cartridge core barrel may be manufactured at a manufacturing facility to include the core, control element supports, and control element drive systems. The cartridge core barrel may be attached to the reactor vessel head so that any motion (e.g., via seismic forces) is transmitted to the control elements and the core with equal direction and magnitude, thereby reducing the possibility of differential motion.

The invention particularly relates to a fast reactor core, which belongs to the technical field of fast reactor cores, and comprises a reactor body container and a reactor core accommodated and supported in the reactor body container, the reactor core comprises fuel assemblies, a reflecting layer assembly, a first shielding assembly, a storage trap assembly and a second shielding assembly which are radially arranged in sequence from inside to outside, and a control rod assembly arranged between the fuel assemblies; the fuel assembly is composed of depleted uranium fuel element rods and uranium-plutonium mixed fuel element rods, and the quantity ratio of the depleted uranium fuel element rods to the uranium-plutonium mixed fuel element rods is determined by the proliferation ratio in the reactor core; and the proliferation ratio in the reactor core is 0.99-1.01. According to the fast reactor core disclosed by the invention, the burnup reactive damage in the subsequent reactor operation period is balanced by utilizing the increased reactivity of the newly proliferated fissile nuclide in the reactor core, so that the instantaneous supercritical safety risk caused by overhigh backup reactivity is fundamentally eliminated.

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.

A nuclear fuel cladding tube for a fast reactor, an assembly thereof, and a method for manufacturing the same are provided. The nuclear fuel cladding tube includes a substrate, a first layer, and a second layer. The substrate has a tubular shape. The first layer is deposited on an outer surface of the substrate. The first layer includes a corrosion-resistant composition. The second layer is disposed on the first layer. The second layer includes silicon carbide fibers infiltrated with silicon carbide. The second layer is configured to inhibit outward creep of the substrate.

Regarding molten salts used in contact with graphite in nuclear reactors, there is a need for them to be easily maintained under strong reducing conditions without causing graphite degradation. [Solution] Use of a molten salt containing aluminum trifluoride and sodium fluoride as a primary coolant for a nuclear fission reactor, wherein the molten salt comes into contact with graphite and aluminum metals during the operation of the nuclear fission reactor.

A mobile heat pipe cooled fast nuclear reactor may be configured for transportation to remote locations and may be able to provide 0.5 to 2 megawatts of power. The mobile heat pipe cooled fast reactor may contain a plurality of heat pipes that are proximate to a plurality of fuel pins inside the reactor. The plurality of heat pipes may extend out of the reactor. The reactor may be configured to be placed in a standard shipping container, and may further be configured to be contained within a cask and attached to a skid for easier transportation.

Molten salt nuclear reactor, of the fast neutron type with a safety vessel around the reactor vessel and a drain tank below the vessels. The invention relates to a nuclear reactor (1) comprising: - at least one nuclear reactor vessel (2) (1) filled with a molten salt fuel bath and provided with at least one outlet in its bottom; - another vessel (8), called the safety vessel, arranged around the reactor vessel by defining an inter-vessel space (E) with the reactor vessel; - a tank (10), called the drain tank, arranged below the vessels, and connected to the inter-vessel space by at least one pipe (11) and to the outlet of the reactor vessel by at least one pipe (12); - a selective closure device (13) for the outlet of the reactor vessel, in the closed position during normal reactor operation and in the open position to carry out the emptying of the reactor vessel.Figure for the abridged version: fig.3.

The present invention relates to a method of operating an MSR, said MSR comprising a reactor core, a fuel loop for molten fuel salt providing a flow path of molten fuel salt into the reactor core through a reactor core inlet and out of the reactor core through a reactor core outlet, said method comprising the steps of: providing at least one location mi on the fuel loop at a distance Li measured along the flow path from the reactor core outlet, wherein the one or more locations mi is outside the reactor core, and the one or more locations mi is shielded from the reactor core measuring the neutron source strength at the one or more locations mi obtaining one or more calculated operating parameters by calculation with input of the value of the measured neutron source strength at one or more locations mi.

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 method is used to design a nuclear reactor using design variables and metric variables. A user specifies ranges for the design variables and target values ​​for the metric variables. A set of design parameter samples is selected. For each sample, the method performs three processes to calculate metric variables for thermal-hydraulic, neutron, and stress. The method applies a cost function to each sample to calculate the ensemble residuals of the metric variables compared to the target values. The method trains a machine learning model using the samples and the calculated ensemble residuals. The method reduces the range of each design variable according to the correlation of the residuals estimated using each design variable and the machine learning model. These steps are repeated until the sample with the smallest residual remains constant over multiple iterations. The method then uses the final machine learning model to evaluate the relative importance of each design variable.

The present invention relates to a nuclear reactor, comprising a reactor vessel, a heat exchange device, a drive device, and a water supply device. The reactor vessel contains liquid coolant and an air cavity. The heat exchange device is disposed within the reactor vessel, wherein the inner wall forms a first cavity for accommodating a core, and the outer and inner walls together define a second cavity. One end of the drive device is connected to the air cavity, and the other end is disposed near the core. The water supply device is in communication with the second cavity. When the nuclear reactor is operating normally, the drive device causes the average density of the liquid coolant above the top of the core to be lower than the average density of the lower cavity below the core, thereby generating a gravity difference that drives the liquid coolant to circulate within the reactor vessel, transferring heat generated by the core. When the nuclear reactor malfunctions, the circulating cold source water in the water supply device circulates in the second cavity, continuously exchanging heat with the core to remove excess heat from the core. The present invention eliminates the need for a large main pump, reduces costs, and improves the safety and reliability of the nuclear reactor.

The invention relates to a nuclear power plant comprising: - a reactor building (10); - at least two reactor pits implanted inside the reactor building, - at least two reactor vessels (2) of molten salt fast neutron nuclear reactors (1), the reactor vessels exhibiting axial symmetry about a central axis, internally delimiting a primary circuit for a fuel in liquid form in which at least one salt is melted, the interior of the vessel being devoid of moderator material; each of the reactor vessels being housed in one of the two reactor pits; and - means for transferring the molten salt fuel from inside one of the two reactor vessels into the other of the two reactor vessels.

A barrier material is used in a structural component of a nuclear reactor (10), the barrier material comprising molybdenum or a molybdenum-based alloy, wherein the barrier material has a molybdenum content of at least 90 wt.%, based on the total weight of the barrier material.

A molten salt reactor system includes a fuel salt system and a coolant salt system. The fuel salt system is configured to circulate a molten fuel salt through a molten salt loop. The coolant salt system is configured to circulate a coolant salt through a coolant loop. The molten salt reactor system further includes a heat exchanger arranged along the molten salt loop and the coolant loop. The heat exchanger is configured to transfer heat from the molten fuel salt of the molten salt loop to the coolant salt of the coolant loop. The heat exchanger is configured to permit gravitational draining of at least one of the molten fuel salt or the coolant salt upon a shutdown event.