9 results about "Fast-neutron reactor" patented technology

The invention relates to the technical field of nuclear reactor design, in particular to a safety assembly, a lead-cooled fast neutron reactor and a passive negative reactivity feedback method. The safety assembly comprises a first positioning piece, a second positioning piece and a containing piece. The first positioning piece and the second positioning piece are respectively connected with the accommodating piece so as to position the two ends of the accommodating piece in the linear direction, the accommodating piece is provided with an accommodating cavity for accommodating a coolant, and one end of the accommodating cavity in the length direction is communicated with the outside of the accommodating piece. The safety assembly is applied to the lead-cooled fast neutron reactor to serve as a safety barrier on the periphery of the reactor core, passive negative reactivity can be rapidly introduced, the structure is simple, implementation is convenient and fast, the nuclear reactor design specification and related technical requirements can be better met, and safety and reliability are further improved.

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.

Fuel, intended to be irradiated in a fast neutron nuclear reactor, comprising grains of at least one metal selected from U, Pu or Th, the grains being compressed in a volume, the fuel being porous, the fuel being characterized in that it comprises open intergranular pores, forming an interconnected porosity, the volume fraction of porosity preferably being between 3% and 30%, more than 50% or 80% of the porosity being an open intergranular porosity,

The invention belongs to the technical field of fourth-generation advanced fast neutron reactors, and particularly relates to an activity monitoring and coating testing method and device in a Po-210 aerosol migration loop. The device comprises an aerosol migration loop and a Po-210 in-situ monitoring device, and the aerosol migration loop is used for carrying out in-situ monitoring on mCi-magnitude Po-210 released at high temperature in a lead-bismuth alloy sample; the gaseous Po-210 moving in the sealed environment is in contact with the surfaces of four functional coating materials of antifouling, protection, sealing and decontamination and generates electrostatic adsorption, chemical adsorption or particle elastic collision effects, and the Po-210 in-situ monitoring device is used for monitoring the activity concentration level of Po-210 aerosol circularly moving in an aerosol migration loop in the whole test process. According to the invention, the adsorption performance test of the Po-210 aerosol on the surfaces of special coatings with four functions of antifouling, decontamination, sealing and protection and the like and transported can be safely and efficiently completed, and the activity level of the Po-210 aerosol transported in the gas space of a sealing system can be accurately monitored.

A compact, liquid-metal cooled, loop-type, fast neutron reactor. The invention relates to a primary / secondary heat exchanger with identical loops, each consisting of a heat transfer module arranged axisymmetrically around the reactor block. Each module comprises an expansion tank (20), a heat exchanger (21), and an electromagnetic pump (22), which alone forms a heat exchange loop between the liquid sodium primary circuit and the gaseous secondary circuit, such as nitrogen, which is a closed Brayton cycle. Figure for the abstract: Fig. 11

This invention relates to the field of nuclear reactors, specifically to a lead-based fast neutron reactor exhaust device and a fission gas collection device. The exhaust device includes fuel rods and a one-way exhaust device. The fuel rods include nuclear fuel pellets and cladding tubes. The one-way exhaust device connects the gas chamber to the outside of the cladding tubes in one direction. A metal coolant is provided inside the pressure vessel to submerge the fuel rods and the one-way exhaust device. In use, the fission gas generated by the nuclear fuel pellets passes through the one-way exhaust device and enters the metal coolant in one direction. The fission gas collection device includes a lead-based fast neutron reactor exhaust device, a temporary storage tank, a multi-stage purification device, and a circulation pump. This invention achieves the purpose of one-way exhaust by connecting a one-way exhaust device to the cladding tube of the fuel rods, so that the fission gas inside the fuel rods is discharged into the primary coolant when the pressure exceeds a certain level. The fission gas collection device collects gaseous fission products in the upper chamber of the reactor pressure vessel.

A nuclear power plant with a nuclear building housing at least one molten salt fast neutron reactor and a fission gas management system for the accumulated gases in the reactor pile headspace. The invention relates to a nuclear power plant comprising: a reactor building (10); at least one reactor vessel shaft (9), located inside the reactor building; at least one reactor vessel (2) (1) filled with a molten salt fuel bath and defining within it a gas space above the free level of the bath, called the pile headspace; another vessel (8), arranged around the reactor vessel and inside the reactor vessel shaft, defining an inter-vessel space (E) with the reactor vessel; at least one fission gas management system (gaseous PF) for the gases accumulated in the reactor vessel pile headspace during normal reactor operation. Figure for the abstract: Fig. 2

This invention belongs to the field of nuclear reactor core design, specifically relating to a method for constructing an equivalent model of the non-fuel region of a fast neutron reactor with complex geometry. First, the core of the three-dimensional fast neutron reactor to be simulated is geometrically divided into several layers along the axial direction. For each layer, a fine-group embedding self-screen resonance model is established. Then, the material of all fuel regions in the core is homogenized and used as average fuel. This average fuel is constructed outside the cylindrical model of the non-fuel region, ensuring that the non-fuel nuclides calculated by the cylindrical model are consistent. n The escape cross section is conserved with the escape cross section calculated by resonance, and an equivalent model of the outermost fuel radius is iteratively searched. Its advantages are: this method can quickly and online obtain the equivalent model of each non-fuel zone in the reactor core; it offers excellent geometric flexibility for complex reactor cores, fully considers environmental effects, and has higher computational accuracy; it can be used for rapid simulation calculations of numerical reactors and engineering applications.

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).