36 results about "Neutron multiplication" patented technology

An apparatus for generating medical isotopes provides an annular fissile solution vessel surrounding a neutron generator. The annular fissile solution vessel provides for good capture of the emitted neutrons and a geometry that provides enhanced stability in an aqueous reactor. A neutron multiplier and/or a neutron moderator may be used to improve the efficiency and control the criticality of the reaction in the annular fissile solution vessel.

The invention belongs to the field of cladding designs of a fusion and fission hybrid reactor, and particularly relates to a Th-U self-sustaining circulating full fused salt fuel hybrid reactor system and an operation method thereof. The Th-U self-sustaining circulating full fused salt fuel hybrid reactor system is characterized in that a fast fission breeder reactor provides an initial easily fission fuel required by starting of a thermal fission reactor, a cladding design of the thermal fission reactor utilizes an arrangement strategy of a seed-cladding to improve the entirety neutron economy of the system, and the purposes of a high energy enlargement factor of the system, tritium breeding and thorium-uranium self-sustaining circulating of the system are realized; <233>U is loaded in an energy generating region, so that the energy generating region has a good neutronics property and is mainly used for realizing the purposes of energy amplification of the system, neutron multiplication and most <233>U breeding of the system; superfluous neutrons enter a tritium producing region and are used for tritium breeding and part of <233>U breeding of the system. According to the hybrid reactor, due to self-sustaining circulating of thorium and uranium, a thorium fuel is converted into <233>U and is gradually burn up in an operation process, and the Th-U self-sustaining circulating full fused salt fuel hybrid reactor system can effectively and stably operate for a long time just by gradually adding the thorium fuel and removing the generated fission product.

The invention relates to a novel test blanket testing device for tritium breeding and heat rejection. The novel test blanket testing device comprises sub-modules; each sub-module comprises a first U-shaped wall, an upper cover plate, a lower cover plate and a sub-module backboard system so as to act as an outer boundary; a middle plate is arranged in each sub-module; two sides of the middle plate are provided with two groups of double-layer U-shaped helium cooling plates; the internal part of the sub-module is divided into neutron multiplication regions and tritium breeding regions by the double-layer U-shaped helium cooling plates and the middle plate; and the sub-module backboard system is provided with a helium cooling pipeline communicated with the double-layer U-shaped helium cooling plates, the cover plates and the middle plate and a tritium extraction pipeline communicated with the tritium breeding regions and the neutron multiplication regions. According to the novel test blanket testing device, a modularized structure is adopted; the double-layer U-shaped cooling plates are adopted in the sub-modules, and structural arrangement, which is conducive to tritium breeding, of the neutron multiplication regions and the tritium breeding regions, is formed; and a bypass is adopted, and therefore, control on the flow rate of a cooling agent can be benefitted, and realization of tritium breeding and efficient energy extraction under the premise of stable and safe operation of an ITER test window can be ensured.

The invention belongs to the field of fusion and fission hybrid energy reactors and cladding design, and particularly relates to a hybrid reactor system arranged by means of water-cooling thorium fuel modules and water-cooling uranium fuel modules in a staggered mode and an operating method. Natural thorium fuel reaction modules and natural uranium fuel reaction modules are annularly and alternately arranged in an optimized mode, a seed-cladding strategy is made full use of to improve overall neutron economy of the system, the aim of making the best of thorium fuel under high-energy magnification is achieved, namely good neutron performance of the water-cooling natural uranium modules is used for compensating for defects of natural thorium neutron multiplication and energy amplification, achievement of energy amplification and neutron multiplication of the system mainly depends on natural uranium, and redundant neutrons generated from the natural uranium are used for driving natural thorium to operate and multiplying 233U. When 233U in the natural thorium is accumulated to a certain quantity, the natural uranium can be extracted step by step and replaced by new natural thorium, a hybrid reactor can be filled with thorium fuel ultimately, and cycle operations of thorium and uranium are achieved.

The invention relates to a neutron detection technology, and discloses a neutron detection cathode, a neutron detector and a neutron detection method. The neutron detection cathode converts neutrons and releases electrons after the incidence of neutrons, and then detects neutron signals indirectly by detecting the electrons. The neutron detection cathode includes a support substrate, an electrodelayer and a neutron capture layer. The electrode layer is arranged on the support substrate. The neutron capture layer is arranged on the other side, opposite to the support substrate, of the electrode layer. The neutron capture layer contains a neutron capture material, and the neutron capture material captures neutrons and then releases electrons. A neutron multiplication detection device further includes a vacuum vessel, a dynode and an anode. The vacuum vessel has an incident window. The electrode layer covers the inner surface of the incident window of the vacuum vessel. The neutron capture layer covers the inner surface of the electrode layer. Thus, accurate multiplication detection or direct detection can be carried out on electrons converted from neutrons through the capture layer,and thermal neutrons can be sensitively detected.

A novel cladding structure for a fusion reactor comprises a U-shaped first wall, cover plates, a front back plate, a rear back plate and a proliferation unit, the U-shaped first wall and the upper andlower cover plates are internally provided with slots, and the upper and lower cover plate and the U-shaped first wall are welded to the front and rear back plates, thereby forming a sealed outer box. The proliferation unit is inserted in the front and rear back plates to be fixedly connected, an internal tritium proliferation agent is wrapped by a cooling plate in the form of a pebble bed, and the pebble bed and the cooling plate are sealed in a neutron multiplication agent. The front and rear back plates and the upper and lower cover plate and the U-shaped first wall form a six-layer platelike gas header which is used for collecting and reallocating coolants and purge gas. According to the novel cladding structure for a fusion reactor, on the premise of ensuring a module proliferation effect, a central area adopts an M-shaped cooling channel, thus a cooling effect can be better improved, and installation procedures are reduced, thereby facilitating replacement and maintenance.

The invention discloses a neutron energy spectrum measurement device and a measurement method thereof. A neutron gamma ray information conversion device of the neutron energy spectrum measurement device comprises a thermal neutron capture material, a fast neutron moderator, a fast neutron inelastic scattering material and a high-energy neutron multiplication material which are of a concentric sphere structure, wherein the central gamma detector is arranged in the center of the concentric sphere, the multilayer thermal neutron capture material, the single-layer fast neutron moderator, the multilayer fast neutron inelastic scattering material and the single-layer high-energy neutron multiplication material sequentially wrap the central gamma detector from inside to outside, and the data acquisition and processing system is electrically connected with the central gamma detector. The device is advantaged in that instantaneous gamma rays generated by reaction of neutrons and various nuclides with different neutron reaction sections are detected through the central gamma detector, and a neutron energy spectrum is reversely deduced through the data acquisition and processing system by utilizing the energy and intensity of characteristic gamma rays and information of various nuclide materials, so detection efficiency of the system is effectively improved; and on-line measurement of theneutron energy spectrum in the wide energy region is realized.

The invention provides a pebble-bed high-temperature gas cooled reactor high neutron multiplication performance fuel element. The element comprises a graphite cladding and a graphite matrix from outside to inside, wherein a plurality of coated fuel particles are uniformly distributed in the graphite matrix according to spherical coordinates, each coated fuel particle comprises a uranium dioxide core particle and a coating layer from inside to outside in the radial direction, each coating layer sequentially comprises a loose pyrolytic carbon layer, an inner compact pyrolytic carbon layer, a silicon carbide layer and an outer compact pyrolytic carbon layer from inside to outside, and the thickness of each layer of the coating layer is obtained by multi-objective optimization under the condition that the diameter and the enrichment degree of the uranium dioxide core particles are fixed. According to the invention, the neutron multiplication performance is improved from the perspective ofoptimizing the thickness of each layer of the coating layer, the purpose of improving the neutron performance by simply increasing the diameter or the enrichment degree of the core particles in the past is avoided, and experiments prove that the neutron performance is improved, and the pebble-bed high-temperature gas cooled reactor high neutron multiplication performance fuel element has very strong economic advantages.

The invention relates to monitoring and testing of a nuclear reactor, specifically to a structure combination of a reactor core for measuring radioactivity and a sensitive instrument, and specificallyprovides a method for measuring reactivity. The reactivity of the reactor core can be evaluated without the need of putting a disturbance neutron source into the reactor core; experimental results and calculation results show that the method can evaluate the critical degree (reactivity) of the reactor by measurement of the neutron multiplication factor of an external neutron source, and providesa novel idea for measuring the reactivity of the reactor core under special working conditions.

The invention provides an efficient neutron conversion screen, and relates to the technical field of neutron photography; an efficient neutron conversion screen is composed of a neutron multiplication layer, a fluorescent layer and a high-purity duralumin plate; wherein the high-purity duralumin plate is coated with the fluorescent layer in a uniform smearing mode, and the fluorescent layer is coated with the neutron multiplication layer in a uniform smearing mode; a neutron multiplication material is placed in the neutron multiplication layer, wherein neutron multiplication is carried out through fission or (n, 2n) or (n, 3n) and other reactions, the number of neutrons reaching the fluorescent layer is increased, and then light emitted after passing through the neutron conversion screen is enhanced. The neutron signal reaching the conversion screen can be amplified, and formation of a clear image and shortening of imaging time are facilitated even under the condition of a weak source or a thick sample to be detected.

The invention provides a <99>Mo subcritical production device based on a Th-U self-sustaining cycle. The <99>Mo subcritical production device comprises an accelerator system, a <99>Mo production system and a separation and purification unit; the accelerator system is used for accelerating and transporting ion beams and generating neutrons; the <99>Mo production system sequentially comprises a neutron multiplication layer, a <232>Th-<233>U salt solution, a neutron reflection layer and a shielding layer from inside to outside; the neutron multiplication layer is used for generating high neutron flux; the <232>Th-< 233>U salt solution is used for <233>U(n, f)<99>Mo reaction to produce < 99>Mo, and meanwhile, neutrons react with <232>Th to be converted into <233>U, so that the self-sustaining cycle of the <232>Th-<233>U is achieved; and the separation and purification unit is used for separation and purification of <99>Mo. The invention further provides a <99>Mo subcritical production method. The device and the method are simple in structure and process, low in cost and high in <99> Mo yield, the Th-U self-sustaining cycle is met, and no extra fuel needs to be added within 15 years.

The invention discloses a fusion reactor solid water cooled blanket tritium proliferating-neutron multiplying agent. A composite core-shell spherical structure is adopted, the core is a beryllium sphere, the shell is ceramic state lithium titanate, and the ceramic state lithium titanate wraps the beryllium sphere. In order to increase the filling factor, the tritium yield of the water cooled blanket is increased, and a two-component sphere bed form with an optimized diameter ratio is adopted. A water cooled blanket filled by the novel proliferating-multiplying agent can overcome the problem that beryllium taken as a neutron multiplying agent may contact with water in an accident, and hydrogen is generated; and thus the safety of the water cooled blanket is effectively improved. Furthermore, multiplied neutrons generated by the beryllium core of the proliferating-multiplying agent spheres must go through the proliferation layer that wraps the core during the releasing process, in a macroscopic view, the happening rate of reactions between neutrons and the proliferating agent is increased, and thus the total tritium yield of the blanket is increased.