256 results about "Neutron irradiation" patented technology

A present invention provides an internal circulating irradiation capsule available for the production of iodine-125 and a related production method. The irradiation capsule filled with xenon gas has a lower irradiation part, an upper irradiation part, and a neutron control member. The lower irradiation part is inserted into an irradiation hole of a reactor core and irradiated with a large quantity of neutron directly. When neutron is radiated to the xenon gas, iodine-125 is produced from xenon gas. The upper irradiation part protrudes from the irradiation hole, and iodine-125 is transferred to the upper irradiation part by convection and solidified in the upper part. The neutron control member reduces neutron in the upper part to produce iodine-125 of high purity and radioactivity in a large quantity.

The present invention relates to a method for preparing a radioactive film for local radioactive treatment. More particularly, the present invention relates to a method for preparing a radioactive film comprising the steps of; dissolving 0.1˜14.5 weight % of a stable nuclide and 13˜32.5 weight % of a film-forming base for the total amount of a solvent in the solvent; applying a stable nuclide solution on a release paper by a coater and drying; and irradiating a stable nuclide film with neutrons in a nuclear reactor. A method for preparing a radioactive film according to the present invention provides a radioactive film having a uniform distribution of radionuclides and an even thickness. Therefore, the therapeutic efficacy of the radioactive film for selective treatment of a lesion may be maximized by attaching the radioactive film on a patient's skin or a mucous membrane and by direct radioactive radiation.

A method for detecting an explosive in an object under investigation involves the initial X-ray irradiation of the object under investigation, e.g. a piece of luggage or mailing, and forming its X-ray images; using the X-ray images to detect areas with a high density of organic materials and identifying articles therein; determining the location, dimensions and supposed mass of an unidentified article; determining and forming a directional pattern of the neutron radiator corresponding to the dimensions of the unidentified article. The method further includes subsequent thermal neutron irradiation of the area with the unidentified article; recording gamma-ray quanta having the energy of 10.8 MeV and cascade gamma-ray quanta with energies of 5.534 and 5.266 MeV by at least two gamma-ray detectors; counting of simultaneously recorded pairs of cascade gamma-ray quanta; determination of the overall gamma-ray intensity, taking into account weight factors in readings of the detectors; determination of the threshold value for the overall gamma-ray intensity basing on the supposed mass of explosive being detected; and making a decision in the event the threshold value of overall gamma-ray intensity is exceeded. When checking small-size objects, the neutron irradiation step is preceded by replacing the ambient air by a gaseous medium not containing nitrogen.

The invention discloses an oxide dispersion strengthened low-activation martensitic steel. A substrate is a CLAM steel and contains 0.2 to 0.5 percent of Y2O3 and 0.10 to 0.50 percent of Ti. The method comprises the following steps that: CLAM steel powder, Y2O3 powder and Ti powder are evenly mixed and put in a sealed container for degassing, subjected to mechanical alloying, hot isostatic pressing or hot-pressing sintering and densification molding under the protection of high-purity argon gas, then subjected to hot squeezing or forging and rolling and other machining and molding processes, and the needed section material is prepared; and finally, the section material is subjected to the treatment of quenching and tempering to prepare the oxide dispersion strengthened low-activation martensitic steel ODS-CLAM. The oxide dispersion strengthened low-activation martensitic steel has the advantages that: the low-activation martensitic steel realizes a martensite-based alloy with oxide strengthening phases evenly dispersed and distributed and crystal grains of a reasonable size, can be used as a structural steel material, has the characteristics of strong neutron irradiation resistance, good high-temperature performance, low activation, etc. and is suitable for a fusion reactor and other environments with strong neutron irradiation and high-temperature.

A neutron beam irradiation system that irradiates an irradiation object with a neutron beam includes: a neutron beam generating section that generates a neutron beam by being irradiated with a charged particle beam; a housing section that includes at least a moderator and that houses the neutron beam generating section; a neutron beam converging section that converges the neutron beam with which the irradiation object is irradiated; a mounting stage on which the irradiation object is mounted; and a relative movement means that relatively moves the mounting stage closer to and away from the neutron beam generating section, the housing section, and the neutron beam converging section.

A neutron elastic scattering detector device for non-invasively detecting the presence of at least one predetermined element of an object of interest. The detector device comprises a neutron source that simultaneously outputs, at a creation time, a neutron in a first direction and an associated baseline particle in a second direction. The first direction is opposite of the second direction. The neutron can impinge upon the predetermined element of the object of interest and scatter therefrom in a third direction. A baseline particle detector system detects the baseline particle and outputs a baseline signal characteristic thereof. A neutron detector system detects the neutron and outputs a scattering signal in characteristic thereof. The processing unit analyzes the baseline signal and the scattering signal to determine the presence of the predetermined element.

The invention aims at providing oxide-dispersion-strengthened low-activation steel applicable to fusion reactor and a preparation method thereof. The technical scheme is characterized in that the low-activation steel comprises the following alloy elements in percent by mass, Fe as the matrix, 0.08%<=C<=0.15%, 8.0%<=Cr<=10.0%, 1.1%<=W<=1.55%, 0.1%<=V<=0.3%, 0.03%<=Ta<=0.2%, 0.1<=Mn<=0.6%, 0.05%<=Y2O3<=0.5%, and a little amount of impurities inevitably mixed during manufacture. The easily-activated elements and impurity elements all capable of generating radionuclides after being subjected to neutron irradiation are strictly controlled according to the following content requirements: N<0.010%, Al<0.010%, Ni<0.005%, Mo<0.005%, Nb<0.010%, Cu<0.010%, P<0.005%, and S<0.005%. The oxide-dispersion-strengthened low-activation steel is uniform in microstructure and excellent in mechanical properties.

This invention relates to a method of manufacturing an improved ferritic or martensitic alloy based on iron and chromium strengthened by a dispersion of oxides, commonly called an Oxide Dispersion Strengthened or ODS alloy, and, more particularly to a method of manufacturing a ferritic or martensitic ODS alloy with large grains based on iron and chromium which has a single phase ferritic or martensitic matrix having an isotropic microstructure and a grain size that is sufficient to guarantee mechanical strength compatible with a use of this alloy at high temperature and/or under neutron irradiation. According to the invention, the method comprises slow cooling of an austenite at a cooling rate less than or equal to the critical cooling rate for transformation of this austenite into ferrite.

The invention belongs to the field of composite material, and in particular relates to a composite structural material and a process for manufacturing a pipeline component using the same. The composite structural material is characterized by adopting a double-layer structure, wherein one layer is made of vanadium alloy material, and the other layer is made of low-activity martensite steel material. In practical application, the side in contact with liquid alkali metal is made of vanadium alloy, and the side in contact with the environment gas or other cooling agents is made of low-activity martensite steel. In the composite structural material provided by the invention, respective advantages of the vanadium alloy and low-activity martensite steel in the application to the sodium cooled fast reactor and fusion reactor liquid metal are sufficiently used, and the problems of neutron irradiation resistance and liquid metal corrosion resistance can be effectively solved. Through the manufacturing process provided by the invention, the utilization rate of material can be obviously improved, and the processing cycle can be remarkably shortened.

The invention relates to the field of fuel cladding tubes with relatively high neutron irradiation resistance, corrosion resistance and high temperature resistance in a nuclear reactor, in particularto a FeCrAl alloy and T91 ferrite/martensite heat-resistant steel composite tube for nuclear reactor nuclear fuel cladding and a manufacturing method for the FeCrAl alloy and T91 ferrite/martensite heat-resistant steel composite tube. The inner layer is a ferrite/martensite heat-resistant steel material, the outer layer is a FeCrAl alloy material, and an iron-based material auxiliary layer is arranged between the inner layer and the outer layer. The manufacturing method for the FeCrAl alloy and T91 ferrite/martensite heat-resistant steel composite tube comprises the following steps: surface polishing of seamless composite tube blank, degassing, assembling and packaging of seamless composite tube blank, thermal deformation processing metallurgical compounding, annealing thermal treatment, cold-rolled cold-drawing and intermediate annealing, final thermal treatment, straightening, cleaning and finished product inspecting. The method is characterized in that the outer layer, an intermediate transition layer and an inner-layer tube are assembled, are assembled and packaged into seamless composite tube blank after gas exhaustion, and are sealed by a welding end head; after being heated,the metallurgical compounded seamless composite tube blank formed by thermal deformation processing is finally subjected to cold-deformation processing to form a finished product of a needed specification.

This invention relates to a cement multi-element analysis device. The neutron multi-element analysis device uses the neutron generator in the D-D reaction as neutron source and emits rapid neutrons of 2.5 Mev. The neutron reacts with the cement element to generate multi-nuclear reaction with different energy radiation gamma rays. The gamma ray detector is to detect the r rays generated by the elements in the cements. The r signals are through main amplifier and are transmitted to the micro machine for monitoring. It uses multi-path gamma spectrum device to test the area of the characteristics gamma ray peak and gives the relative nucleus content through test formula.

In a neutron moderator, a neutron irradiation method, and a hazardous substance detection apparatus, an inspection chamber (21) where an inspection target (A) can be inserted and removed is provided. Around this inspection chamber (21), a thermal neutron absorbing material (15) is provided. A neutron generator(11) is arranged facing the inspection target (A) in the inspection chamber (21), and a neutron moderating material (12) is arranged at an opposing side of the inspection target (A) with respect to the neutron generator (11). The external surface of the neutron moderating material (12) is covered with gamma ray shielding materials (13, 14), and a Ge detector (24) and a BGO detector (25) are provided to detect gamma ray emitted from the inspection target (A). With this configuration, necessary fast neutron and thermal neutron can be taken out, while suppressing generated secondary gamma ray. Accordingly, a hazardous substance can be detected accurately regardless of a constituent element thereof.

The invention discloses a reinforcement method for the single event latchup resistance of a CMOS device. Neutron irradiation is carried out on the CMOS device; a displacement damage is introduced in the neutron irradiation; and a current gain of a parasitical bipolar transistor in an inverter of the CMOS device is reduced, so that P-N-P-N latchup is not generated. The reinforcement method is an external reinforcement method; processing steps to produce the device will not be increased; there is no need to redesign a device layout for the single event latchup effect; and complexity of an original system will not be increased. Thus, the fixed size of the device will not be changed, and a peripheral circuit will not be increased either.

The invention relates to a temperature measurement method taking carborundum crystals irradiated by neutrons as a sensor. The temperature measurement method comprises the following steps that: a plurality of 6H-SiC crystals which are small blocks, are in the same batch and are doped with nitrogen are used as temperature measurement crystals, annealing treatment of different temperatures T is respectively carried out after neutron irradiation is carried out, then the half high width F of the X-optical diffraction peak of each temperature measurement crystal after annealing is respectively tested, the F is used as longitudinal coordinate, the T is used as horizontal coordinate, and an F-T standard curve is mapped; and the temperature measurement crystals irradiated by the neutron in the previous step are embedded into the surface layer or the surface of an article to be tested and high-temperature running is carried out along with a work system containing the article to be tested, then the temperature measurement crystals are taken out, the half full width of the temperature measurement crystals is tested, the half width is compared with the F-T standard curve to find out a temperature value corresponding to the half full width value, and the temperature is just the maximum working temperature of the article to be tested. The method has obvious non-incursion type characteristic, does not need site interpretation, can be used for the temperature test of the high-temperature work system with more than 1200 DEG C and has high testing precision and simple and convenient operation.

The present invention relates generally to an apparatus of assembling a capsule for neutron-irradiation experiments. The capsule may contain test specimens to develop nuclear fuel, and may comprise a capsule main body and protection tube that may be assembled and disassembled using separate joining means. The present invention provides a capsule assembling apparatus that may enable safe and easy assembly/disassembly of the capsule placed at a given depth in a working pool through remote working. The capsule assembling apparatus may comprise a base structure loading the capsule main body, a guiding pipe of a given length extending from the base structure to provide a pathway through which the capsule main body is loaded on the base structure, a damper fixing the capsule main body to the guiding pipe, and a coupler coupling the capsule main body with the protection tube.

The present invention discloses a fusion reactor tungsten divertor structure design based on high temperature fused salt cooling. The fusion reactor tungsten divertor structure design comprises a tungsten surface pair plasma material and tungsten and lanthanum alloy heat sinks. The tungsten and lanthanum alloy heat sinks comprises a tungsten and lanthanum alloy heat sink 1 and a tungsten and lanthanum alloy heat sink 2. The tungsten and lanthanum alloy heat sink 1 is a half pipe with a C-shaped cross section, and the tungsten and lanthanum alloy heat sink 2 is a half pipe with a round angle and a semi-rectangle-shaped cross section. The tungsten surface pair plasma material is connected to the tungsten and lanthanum alloy heat sink 1, and the tungsten and lanthanum alloy heat sink 1 is connected to the tungsten and lanthanum alloy heat sink 2 to form a whole pipe. through the effective combination of tungsten and lanthanum alloy materials and a high-temperature fused salt cooling agent, the fusion reactor tungsten divertor structure design based on high temperature fused salt cooling is provided to adapt to a fusion reactor high-flux neutron irradiation environment, the heat bearing capacity can reach a 10-20MW/m2 steady-state thermal load, the structural material neutron activation is low, the , nuclear waste processing after component retirement is relatively easy, and the improvement of fusion reactor power generation economical efficiency is facilitated.

The invention relates to a preparation method of anti-irradiation low activation steel strengthened by a nano-precipitation phase, and belongs to the technical field of nuclear power steel. The methodcomprises the following steps of: firstly preparing a FeTaC intermediate alloy, and then preparing and obtaining the steel by a smelting process, a forging process, a rolling process and a heat treatment process sequentially. In the invention, a pure metal Ta is replaced by preparing the FeTaC intermediate alloy so as to avoid the burning loss of the steel caused by the high oxidation activity ofthe Ta metal during the smelting process; the burning loss of the Ta element is suppressed by the high temperature carbon deoxidation technology during the smelting process, and the Ta yield and reach more than 90%; the ultra-fine martensitic steel with excellent high-temperature creep performance and anti-neutron irradiation performance is obtained by optimizing the rolling process and promotingthe high-density uniform dispersion of the nano-precipitation phase to produce strengthening and refining grain action. The creep duration of the anti-irradiation low activation steel under the loading condition of 550 DEG C and 195MPa exceeds 5,000h.

The invention discloses a small high-yield and deuterium-deuterium neutron generator. Modular distributed high-frequency ion sources are adopted and evenly distributed on the outer surface of a ceramic cylinder with the spherical end, and deuterium ion beams distributed evenly are output, wherein the flow intensity of the deuterium ion beams is larger than 1 A, and the single atom proportion is larger than 80%; the deuterium ion beams are accelerated in a cylindrical accelerating electric field with the spherical end and bombard a cylindrical metal or ceramic self-forming target to cause a deuterium/deuterium reaction and then generate neutrons of 2.45 MeV, and the self-forming target is located at the high-potential end and provided with the spherical end. The number of the modular distributed high-frequency ion sources and the area of the self-forming target are not limited, the yield of the neutrons of the deuterium/deuterium reaction is larger than 1011 n/s, and no radioactive pollutants are discharged. The neutron generator is suitable for commercialized application such as the fields of boron neutron capture treatment, neutron radiography, on-line material component neutron detection, neutron irradiation modification and californium neutron source substitute products.

The invention relates to a method for preparing a boron, lead and aluminum composite board preventing X rays, gamma rays and neutron irradiation to overcome the defect that a nuclear radiation and ray shielding material is single in shielding property. According to the method, aluminum powder, boron carbide powder and lead powder serve as raw materials, ball grinding, powder processing, material mixing, microwave heating, vacuum hot pressing blank stamping, and heating rolling forming are carried out, and then the boron, lead and aluminum composite board is prepared. The preparing method is advanced in technology, data are accurate and detailed, the prepared boron, lead and aluminum composite board has a good ray and neutron irradiation shielding effect, the X-ray shielding rate is larger than or equal to 95 percent, the gamma-ray shielding rate is larger than or equal to 40 percent, the neutron absorptivity is larger than or equal to 90 percent, boron carbide is evenly distributed, particles and a base body are combined tightly, high mechanical strength is achieved, the surface microhardness reaches 186.3 HV, the bending angle is larger than or equal to 15 degrees, the tensile strength is 305 MPa, the elongation after fracture is larger than or equal to 6 percent, the mechanical property and the shielding property of the boron, lead and aluminum composite board are improved, and the boron, lead and aluminum composite board can be used for single irradiation protection and can also be used for various types of radiation protection.

The invention discloses a metallic fast reactor fuel element irradiation test device. The device can be used for carrying out neutron irradiation test on metallic fast reactor fuel in a thermal spectrum research reactor and has the functions of neutron spectrum hardening, metallic fuel irradiation temperature control, fuel element heat release power measurement and the like. The device comprises aprotection tube, a cadmium tube, an irradiation test piece, a related gas pipeline, a thermocouple and the like. According to the device, a cadmium metal layer is adopted to absorb thermal neutrons to reduce the thermal neutron flux rate in the device, so that the neutron energy spectrum of a test fuel element is close to that of a fast neutron reactor; and the temperature difference is established between air gaps and a liquid metal layer outside a fuel rod, and the gas components in the air gaps in each irradiation part are independently adjusted, so that the temperature of fuel core bodiesin different irradiation parts are controlled within a required temperature range.