162 results about "Light-water reactor" patented technology

A light water reactor to safely convert depleted uranium into a fuel source that could be used as a sustainable source of energy for centuries. The reactor is a type of breed-burn reactor uniquely combined with a proliferation-resistant fuel cycle with no uranium enrichment and no plutonium isolation. It is comprised of a compact factory-produced fast region and a thermal region that produces about 95% of the core power and contains the passageways for transports of delayed-neutron emitters to the fast region, where they can provide additional neutrons (source-based mode) or all the necessary excitation without an external neutron source (self-regulating mode). A second embodiment of the invention is a small unit driven by a neutron source with beam recycling for propulsion, electrical power or radioisotope production. It could also serve as a demonstration facility for the transmutation reactor with fission-fusion fuel.

An integral pressurized light water reactor having most of the components of a primary side of a pressurized water reactor nuclear steam supply system housed in a single pressure vessel with a pressurizer separated from the remaining reactor system by a surge separator having multiple layers of separated steel plates with a number of concentric baffles extending therebetween. A circuitous flow path is provided through and between the plates and concentric baffles and a relatively stagnant pool of coolant is maintained within an innermost zone between the plates to provide thermal isolation.

A high Fe-containing zirconium composition having excellent corrosion resistance and a preparation method thereof. Specifically, disclosed are a high Fe-containing zirconium composition having excellent corrosion resistance and a preparation method thereof, the composition comprising: 0.5-1.0 wt % iron; 0.25-0.5 wt % chromium; 0.06-0.18 wt % oxygen; at least one element selected from the group consisting of 0.2-0.5 wt % tin, 0.1-0.3 wt % niobium and 0.05-0.3 wt % copper; and the balance of zirconium. The zirconium alloy has excellent corrosion resistance, and thus can be used as a material for nuclear fuel claddings, spacer grids and nuclear reactor core structures in light water reactor and heavy water reactor nuclear power plants.

A hydraulic drive type partial inter-tube lancing system for cleaning a steam generator in a nuclear power plant, which removes foreign matter, such as sludge, deposited around heat transfer tubes in the steam generator, is disclosed. More particularly, a hydraulic drive type partial inter-tube lancing system, which serves to clean a steam generator of a light-water reactor in a nuclear power plant by removing sludge, attached inside the steam generator, using high-pressure water, is disclosed.

The invention concerns a method of producing and treating a sheet suited to be used as a component or as a part of a component in a fuel assembly for a nuclear light water reactor, which method comprises: a) producing a sheet of a Zr-based alloy by forging, hot rolling and cold rolling in a suitable number of steps, b) carrying out an α+β quenching or a β quenching of the sheet when the sheet has been produced to a thickness which is equal to or almost equal to the final thickness of the finished sheet, c) heat treating the sheet in the α-phase temperature range of said alloy, wherein the sheet is stretched during the heat treatment according to step c). The invention also concerns a use of a sheet that is produced and treated according to this method, and to methods and fuel assemblies of which said sheet forms a part.

A method and apparatus for a fret resistant fuel rod for a Boiling Water Reactor (BWR) nuclear fuel bundle. An applied material entrained with fret resistant particles is melted or otherwise fused to a melted, thin layer of the fuel rod cladding. The applied material is made of a material that is chemically compatible with the fuel rod cladding, allowing the fret resistant particles to be captured in the thin layer of re-solidified cladding material to produce an effective and resilient fret resistant layer on an outer layer of the cladding.

The invention refers to a nuclear fuel, a fuel element, a fuel assembly and a method of manufacturing a nuclear fuel. The nuclear fuel is adapted for use in a water cooled nuclear reactor, including light water reactors LWR, such as Boiling Water Reactors BWR and Pressure Water Reactors PWR. The nuclear fuel comprises an uranium-containing compound consisting of UN. The uranium content of the uranium-containing compound comprises less than 10% by weight of the isotope ²³⁵U. The nuclear fuel comprises an additive substantially consisting of at least one element, in elementary form or as a compound, selected from the group consisting of Zr, Mo, Si, Al, Nb and U.

The invention provides a lower pipe seat of a light-water reactor nuclear fuel assembly. The lower pipe seat comprises a frame body, a plurality of first main ribs, a plurality of second main ribs, and a plurality of pipe fitting installation parts, wherein the first main ribs are arranged in the frame body in parallel at intervals, the second main ribs are arranged in the frame body in parallel at intervals, the frame body comprises a first diagonal line and a second diagonal line which is intersected with the first diagonal line, a plurality of first main ribs and/or a plurality of second main ribs are parallel to the first diagonal line and/or the second diagonal line, a plurality of first main ribs and a plurality of second main ribs are intersected to divide the interior of the frame body into a plurality of through drain holes; and a plurality of pipe fitting installation parts are respectively arranged at positions where a plurality of first main ribs and a plurality of second main ribs are intersected. The invention further provides a bottom device of the light-water reactor nuclear fuel assembly. According to the lower pipe seat, a plurality of first main ribs and/or a plurality of second main ribs are parallel to the first diagonal line and/or the second diagonal line respectively, so that the performance of the lower pipe seat can be effectively prompted.

A 17×17 jacketless fuel assembly for a PWR-type light-water reactor uses thorium as the fuel. The fuel assembly has a square shape in the plan view, a seed region, a blanket region that encircles it, an upper nozzle, and a lower nozzle. The fuel elements of the seed region re arranged in the rows and columns of a square coordinate grid and have a four-lobed profile that forms spiral spacer ribs along the length of a fuel element. The blanket region contains a frame structure within which a bundle of fuel elements made from thorium with the addition of enriched uranium is positioned. The blanket region fuel elements are arranged in the two or three rows and columns of a square coordinate grid.

An emergency core cooling system directly injects emergency core cooling water, which is supplied from a high-pressure safety injection pump or a safety injection tank for a pressurized light water reactor, into a reactor vessel downcomer. A pipe connector is completely removed from between each direct vessel injection nozzle and each injection extension duct installed on an outer surface of the core barrel, which are opposite to each other. An emergency core cooling water intake port, through which the water is injected from each direct vessel injection nozzle, is formed on the surface of each injection extension duct facing an axis of each direct vessel injection nozzle. Thereby, a structure in which a jet of the emergency core cooling water flows into the injection extension ducts is adopted in a hydraulic connection fashion.

The invention provides an anti-foreign matter plate of a light water reactor nuclear fuel component. The anti-foreign matter plate comprises an edge part, a plurality of pipe orifice units and a plurality of filtering hole units, wherein the plurality of the pipe orifice units are arranged on the inner side of the edge part like an independent array, and the plurality of the filtering hole units are flatly laid and arranged between the edge part and the plurality of the pipe orifice units. The invention further provides a bottom device of the light water reactor nuclear fuel component. The bottom device comprises the anti-foreign matter plate. Compared with the prior art, as the pipe orifice units of the anti-foreign matter plate disclosed by the invention are arranged like the independent array and the filtering hole units are flatly laid and arranged, the number of the filtering hole units on the anti-foreign matter plate can be maximized under the same situations, the circulation area of cooling water can be further increased, the resistance of the cooling water when the cooling water passes through the anti-foreign matter plate, and the loss of pressure drop can be also reduced.

Disclosed herein are a zirconium alloy composition, which exhibits excellent corrosion resistance by varying the kinds of metal oxides and controlling the size of precipitates of the composition, including: 1.05˜1.45 wt % of Nb; one or more selected from the group consisting of 0.1˜0.7 wt % of Fe and 0.05˜0.6 wt % of Cr; and residual Zr, and a method of preparing the same. The zirconium alloy composition exhibits excellent corrosion resistance by controlling the kinds and amounts of the elements included in the zirconium alloy composition and the heat-treatment temperature and thus varying the kinds of metal oxides formed during an oxidation process and controlling the size of precipitates of the zirconium alloy, so that it can be usefully used as a raw material for nuclear fuel cladding tubes, spacer grids, nuclear reactor internals and the like of a light-water reactor or a heavy-water reactor in a nuclear power plant.

A zirconium alloy suitable for forming reactor components that exhibit reduced irradiation growth and improved corrosion resistance during operation of a light water reactor (LWR), for example, a boiling water reactor (BWR). During operation of the reactor, the reactor components will be exposed to a strong, and frequently asymmetrical, radiation fields sufficient to induce or accelerate corrosion of the irradiated alloy surfaces within the reactor core. Reactor components fabricated from the disclosed zirconium alloy will also tend to exhibit an improved tolerance for cold-working during fabrication of the component, thereby simplifying the fabrication of such components by reducing or eliminating subsequent thermal processing, for example, anneals, without unduly degrading the performance of the finished component.

A fully ceramic micro-encapsulated fuel assembly for a light water nuclear reactor includes a set of FCM fuel rods bundled in a square matrix arrangement. Fully ceramic micro-encapsulated fuel assemblies replace standard reference solid fuel assemblies with smaller number of FCM fuel rods that have a larger diameter than the diameter of the solid standard reference fuel rods, while keeping similar amounts of fissile material in the fuel assembly and maintaining comparable rates of burnup and number of EFPDs, and compatible power production, heat transfer and thermo-hydraulic features. A fully ceramic micro-encapsulated fuel rod includes multiple fully ceramic micro-encapsulated fuel pellets, which are comprised of tristructural-isotropic particles. In order to obtain compatible burnup rates with the standard reference fuel, the tristructural-isotropic particles have preferentially large diameter and packing fraction. Furthermore, Erbium oxide is included in the sintered mix of the SiC compact to serve as a burnable poison.

A core of a light water reactor having a plurality of fuel assemblies, which are loaded in said core, having nuclear fuel material containing a plurality of isotopes of transuranium nuclides, an upper blanket zone, a lower blanket zone, and a fissile zone, in which the transuranium nuclides are contained, disposed between the upper blanket zone and the lower blanket zone;

• • wherein a ratio of Pu-239 in all the transuranium nuclides contained in the loaded fuel assembly is in a range of 40 to 60% when burnup of the fuel assembly is 0;
  • sum of a height of the lower blanket zone and a height of the upper blanket zone is in a range of 250 to 600 mm; and
  • the height of said lower blanket zone is in a range of 1.6 to 12 times the height of the upper blanket zone.

The invention relates to a telescoping guide tube used for a light-water reactor nuclear power station fuel assembly. The telescoping guide tube comprises an inner sleeve and an outer sleeve which is closely sleeved around the inner sleeve; the inner sleeve comprises a large-diameter part, a small-diameter part and a buffering part connecting the large-diameter part with the small-diameter part; inner walls of the large-diameter part, the small-diameter part and the buffering part transit and are connected smoothly; the outer sleeve comprises a sleeve part and a connection part; the sleeve part is closely sleeved around the small-diameter part, and the connection part is in fixed connection with the buffering part. According to the invention, the outer sleeve is closely sleeved around the inner sleeve, which enables the sleeve part and the connection part to be respectively sleeved around the small-diameter part and the buffering part, thereby strengthening the strength of the whole guide tube and further strengthening the strength of the light-water reactor nuclear power station fuel assembly; meanwhile, the buffering part is reinforced, and therefore, control rods are easier to absorb energy when falling, thereby improving bending resistance; fabrication and assembly of the inner sleeve and the outer sleeve are convenient and are easy to realize.

The present invention is directed to a plutonium-based nuclear fuel that is suitable for burning weapon-grade and reactor-grade plutonium in a light water reactor, thereby reducing the amount of such material that could potentially be used to manufacture a weapon. In one embodiment, the fuel is comprised of plutonium, zirconium hydride, and thorium, with the zirconium hydride comprising more than about 20% by weight of the fuel.

The invention belongs to a combustible toxic fuel, in particular to a B and Gd-containing overall composite combustible toxic fuel and a preparation method. The fuel aims to control excess reactivity and meets the requirements of long-period reactivity control and moderator negative temperature coefficient control on the composite combustible toxic fuel. The composite combustible toxic fuel consists of a ZrB2 coating and a UO2-Gd2O3, wherein the UO2-Gd2O3 comprises 2 to 12 mass percent of Gd2O3; and the linear density of concentrated <10>B is 0.1 to 1.0 mg/cm. By using the overall composite combustible toxic fuel, the requirements of the long-period reactivity control and the moderator negative temperature coefficient control on the composite combustible toxic fuel can be met; moreover, the cost of the composite combustible toxic fuel is lower than that of an Er-containing combustible toxic fuel. Simultaneously the service life of a reactor core is prolonged, the refueling period is prolonged and the nuclear power operation cost is reduced, so that the refueling period of a light-water reactor nuclear power station fuel can reach 24 to 48 months.

A 12×12 fully ceramic micro-encapsulated fuel assembly for a light water nuclear reactor includes a set of FCM fuel rods bundled in a square matrix arrangement. The fully ceramic micro-encapsulated fuel is comprised of tristructural-isotropic particles. Each tristructural-isotropic particle has a kernel that is comprised uranium nitride. The kernel diameter is 400 or more micrometers. The fully ceramic micro-encapsulated fuel is further mixed with a burnable poison material.

A method for reprocessing spent nuclear fuel from a light water reactor includes the step of reacting spent nuclear fuel in a voloxidation vessel with an oxidizing gas having nitrogen dioxide and oxygen for a period sufficient to generate a solid oxidation product of the spent nuclear fuel. The reacting step includes the step of reacting, in a first zone of the voloxidation vessel, spent nuclear fuel with the oxidizing gas at a temperature ranging from 200-450° C. to form an oxidized reaction product, and regenerating nitrogen dioxide, in a second zone of the voloxidation vessel, by reacting oxidizing gas comprising nitrogen monoxide and oxygen at a temperature ranging from 0-80° C. The first zone and the second zone can be separate. A voloxidation system is also disclosed.

The invention discloses a multilayer protective coating with high-temperature steam oxidation resistance and hot water corrosion resistance. The multilayer protective coating comprises the following components: a Cr layer and a CrAlSiN layer which are periodically and alternately deposited, wherein the most surface layer of the coating is the Cr layer; the cycle number of the alternate depositionis 1-20; the thickness of the Cr layer and the CrAlSiN layer in the unit period is 0.5-10 microns, and the thickness ratio is 2: 3-3: 2. The multilayer protective coating is formed by alternately depositing theCr layer and the CrAlSiN layer on the surface of a zirconium alloy substrate by adopting a magnetron sputtering method. The invention also provides a zirconium alloy covering housing manufactured by the abovementioned method. The multilayer protective coating has the advantages of hot water corrosion resistance under the normal working condition (600-650 DEG C) and high-temperature steamoxidation resistance under the accident fault-tolerant working condition (1000-1200 DEG C), and effectively meets the protection requirements under two working conditions of a light water reactor.

A nuclear reactor is surrounded by a reactor radiological containment structure. Depressurization lines running from the reactor automatically vent the reactor to the containment structure or to a compartment in the containment structure when a low pressure condition exists in the reactor. The depressurization lines include biased-open passive valves and actively actuated isolation valves arranged in series.