The invention relates to nuclear engineering, and more particularly to ensuring the safety of nuclear reactors, primarily reactors with a heavy liquid metal coolant based on lead or on alloys based on lead and bismuth. The claimed nuclear reactor has, at the inlet to the core, a filter (5) with openings (11, 12), arranged at different heights on the filter (5), for allowing the passage of a coolant and catching particulate impurities. The size of openings (11) does not exceed the typical size of the minimum flow cross section in the core, and openings (11, 12) are spaced apart heightwise on the filter (5) so that none of the particulate impurities can simultaneously block openings at different heights. The technical result consists in more thoroughly purifying coolant of particulate impurities, with a negligible decrease in the level of natural circulation of the coolant.
G21C 19/30 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products
2.
Nuclear reactor using natural and artificial circulation methods
Embodiments of the present disclosure include an integral nuclear reactor having a core fluidly coupled to an inlet chamber and to an outlet chamber. In some instances, the nuclear reactor may include a hub to house the core, the chambers, and the protective plug. The hub may include a window allowing a heat transfer fluid to flow from the outlet chamber, through the hub, and enter an annular space between the hub and a separation shell. The heat transfer fluid may flow into an inlet of a heat exchanger. The heat transfer fluid may flow through the heat exchanger before exiting at a heat exchanger outlet. The heat transfer fluid may enter an annular delay tank before flowing down an annular downcomer duct formed by the separation shell being housed in a reactor vessel. The heat transfer fluid may flow from the annular downcomer duct and into the inlet chamber.
G21C 1/32 - Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
G21C 15/02 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements
G21C 15/14 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from ducts conducting a hot fluidArrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from ducts comprising auxiliary apparatus, e.g. pumps, cameras
G21C 15/243 - Promoting flow of the coolant for liquids
The claimed embodiments of a nuclear reactor of the integral type relate to nuclear engineering and can be used in reactor systems having different types of liquid coolants with a high boiling point such as, for example, liquid metals, molten salts, etc. Structural features of the claimed embodiments of the invention, in which a spiral heat exchanger sectioned along a secondary coolant circuit is used, provide an increase in cost-performance indicators by reducing the metal consumption of the reactor; efficiently use the inner volume of the reactor; increase safety in the event of leaks in tubes of the heat exchanger; and provide the possibility of removing residual heat in the period after the shield plug is extracted before fuel is discharged.
G21C 15/02 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements
G21C 9/00 - Emergency protection arrangements structurally associated with the reactor
4.
METHOD FOR THE LONG-TERM STORAGE OF SPENT NUCLEAR FUEL AND COOLING AND STORAGE TANK FOR THE IMPLEMENTATION THEREOF
The group of inventions relates to the nuclear power industry. A method for the long-term storage of spent nuclear fuel consists in unloading fuel whole within a removable assembly without dismantling the reactor core, and placing it in a cooling and storage tank disposed in a pit having a cooling system and being filled with a liquid lead-bismuth eutectic alloy, in which conditions are provided for maintaining the liquid state of the lead-bismuth alloy and for monitoring the temperature thereof for decay heat removal; removing the tank and placing same in an on-site cask without exceeding the permissible temperature of the lead-bismuth alloy, with heat decay removal taking place until the lead-bismuth alloy hardens in the tank; transferring the tank to a transport cask without the implementation of further decay heat removal measures. A cooling and storage tank is also claimed. The group of inventions makes it possible to simplify and reduce the length of the refueling process in the case of nuclear fuel with a high level of decay heat.
A method for preparing to reload a fast nuclear reactor with heavy liquid metal coolant includes extracting a reactor plug and extracting a removable reactor block. The method includes installing handling equipment to form an unloading path under radiation safety conditions. The reactor plug is extracted from the reactor monoblock housing and transported to a plug shaft. The removable reactor block is extracted from the reactor monoblock housing and transported to a block shaft for later disassembly.
G21C 19/105 - Lifting devices or pulling devices adapted for co-operation with fuel elements or with control elements with grasping or spreading coupling elements
G21C 19/10 - Lifting devices or pulling devices adapted for co-operation with fuel elements or with control elements
G21C 19/19 - Reactor parts specifically adapted to facilitate handling, e.g. to facilitate charging or discharging of fuel elements
G21C 19/20 - Arrangements for introducing objects into the pressure vesselArrangements for handling objects within the pressure vesselArrangements for removing objects from the pressure vessel
G21C 1/02 - Fast fission reactors, i.e. reactors not using a moderator
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
The invention relates to nuclear engineering and more particularly to controlled reactor start-up. The invention addresses a secondary startup neutron source by creating additional safety barriers between the coolant and the source active part materials. The secondary startup neutron source is designed as a steel enclosure housing an ampule containing antimony in the central enclosure made of a niobium-based alloy unreactive with antimony, with a beryllium powder bed located between the antimony enclosure and the ampule enclosure. An upper gas collector, located above the ampule serves as a compensation volume collecting gaseous fission products. The ampule is supported by a reflector and a bottom gas collector. The gas collectors, reflector, ampule enclosure and washers are made of martensite-ferrite grade steel.
Molten metal transfer pump, in which a shaft (4) with the impeller (5) mounted on the shaft (4) is installed on the upper bearing (2) and the lower journal plain bearing (3). The lower journal plain bearing (3) has rotor (15) and stator (16) parts. The rotor part (15) is made in the form of two split bushings (17) mounted on the shaft (4), and the stator part (16) is made in the form of two split bushings (18) fixed in the cage (19) in axial alignment with the shaft (4). Bushings (17) (18) are fixed correspondingly with flat rings (24) (33) and composed of cylinder segments (20), (28) equidistantly placed in a circumferential direction, located correspondingly in the cylindrical groove (21) on the shaft and cylindrical groove (29) of the cage (19) and fixed with cone hold-down rings (22), (30) radially, and with spring rings (23), (31) axially.
F04D 7/06 - Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metal
A hydrogen detector for gas and fluid media is disclosed. The detector includes a selective membrane and a housing. Within the housing is a potential measuring unit and a ceramic sensing element made of a solid electrolyte. A standard electrode is located within a cavity of the ceramic sensing element and a porous platinum electrode is applied to an external layer of the ceramic sensing element. A potential measuring unit passes through a sealed lead-in at the upper end of the housing and is brought out to the standard electrode. The selective membrane, which is attached to a hole in the end of the lower bushing, is closed with a plug. The cavity limited by the inner surface of the lower bushing, the external part of the bottom of the ceramic sensing element and the inner surfaces of the selective membrane and the plug is leak-tight.
Heat exchangers for use in heavy liquid metal coolant mediums that ensure reliable fixation and spacing of heat exchanger tubes. A first embodiment includes one supporting spacer grid having a cylindrical shell and two or more tiers of plates spaced apart at a preset gap, while the width of each plate is parallel to the shell axis. Ends of all plates are fixed to the shell such that plates of any tier are parallel to each other and located at the preset gap. Plates of different tiers are criss-crossed at an angle of 60 degrees along the shell axles and fastened together at the crossing points. Another embodiment includes three dividers which run through the cylinder axis; their ends are connected to the shell and are spaced at an angle of 60 degrees.
F28F 9/22 - Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
F28D 7/16 - Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
G21C 3/32 - Bundles of parallel pin-, rod-, or tube-shaped fuel elements
F16L 3/23 - Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets specially adapted for supporting a number of parallel pipes at intervals for a bundle of pipes or a plurality of pipes placed side by side in contact with each other
F16L 3/22 - Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets specially adapted for supporting a number of parallel pipes at intervals
G21C 3/352 - Spacer grids formed of assembled intersecting strips
10.
Method and control system for gas injection into coolant and nuclear reactor plant
A nuclear reactor plant including a reactor; a coolant in the reactor; a gas system connected to the reactor and adapted to provide a gas supply to and gas removal from a space above the coolant; and a device for injection of gas into the coolant. The device is installed partially in the coolant and partially in the space above the coolant, and is adapted to supply gas from the space above the coolant to the coolant. The gas system and device are configured to carry out steps including: supplying gas to be injected into the coolant from the gas system to the space above the coolant space; injecting gas into the coolant by maintaining the gas pressure higher than coolant pressure in the device; and injecting gas into the gas system from the space above the coolant.
G21C 15/00 - Cooling arrangements within the pressure vessel containing the coreSelection of specific coolants
C23F 11/02 - Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in air or gases by adding vapour phase inhibitors
C23F 11/00 - Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
G21C 17/022 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators
G21C 19/28 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core
G21C 19/303 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products specially adapted for gases
11.
Control rod drive includes an electric drive and a toothed rack
Systems for controlling and protesting nuclear reactors. A drive of an emergency safety rod of a nuclear reactor includes an electric drive, a reduction gear, and a rack-and-pinion gear. The electric drive contains a contactless electric motor based on permanent magnets, which is installed in the housing of the electric drive with a motor rotor position sensor, and a reduction gear for changing the rate of rotation of the electric drive. A toothed rack is installed along the axis of the rack-and-pinion gear in order to provide for the reciprocating motion of a system absorber rod connected thereto. A toothed electromagnetic clutch having a contactless current supply is installed on an inner shaft of the rack-and-pinion gear, enabling the rigid and simultaneous mechanical coupling of half-couplings, and the drive contains a reverse-motion coupling, a rack-separation spring and toothed rack position sensors.
The method and system for control of oxygen concentration in the coolant of a reactor plant including a reactor, coolant in the reactor, gas system, mass-exchange apparatus, disperser and an oxygen sensor in the coolant have been disclosed. The method includes the following steps implemented by the system: estimation of the oxygen concentration; comparison of the oxygen concentration with the permissible value; if the oxygen concentration is reduced, comparison of the reduction value and\or rate with the corresponding threshold value; if the reduction value and\or rate of oxygen concentration is below the threshold value, activation of the mass-exchange apparatus; if the reduction value and/or rate of oxygen concentration is above the corresponding threshold value, supply of oxygen-containing gas from the gas system to the near-coolant space and/or activation of the disperser. Technical result: improvement of controllability of oxygen concentration in coolant, enhancement of safety and extension of reactor plant operating life.
G21C 15/02 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements
G21C 17/025 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators for monitoring liquid metal coolants
G21C 19/303 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products specially adapted for gases
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
13.
Method for inner-contour passivation of steel surfaces of nuclear reactor
A method for the inner-contour passivation of steel surfaces of a nuclear reactor consists in filling a first contour of a nuclear reactor with a liquid metal coolant, introducing a reagent into the liquid metal coolant, said reagent interacting with the material of elements of the first contour, forming a protective film, and heating the liquid metal coolant, having the reagent introduced therein, to a temperature allowing for conditions for forming the protective film. The liquid metal coolant having the reagent introduced therein is kept at said temperature until a continuous protective film is formed on the surface of the material of the elements of the first contour. The liquid metal coolant having reagent introduced therein is heated by means of the friction thereof against rotating vanes of a vane pump, which is submerged in the liquid metal coolant. The present invention thus provides for a simpler passivation process, a more reliable passivation mode, an increase in the safety thereof and a simpler control over the process of passivation of steel surfaces.
C23C 22/73 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
G21C 17/022 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators
The invention relates to the field of nuclear technology, and specifically to a method for the in situ passivation of steel surfaces. The method consists in installing, in a position intended for a regular core, a core simulator in the form of a model of the core, which models the shape thereof, the relative position of the core components, and also the mass characteristics thereof; next, the reactor is filled with a heavy liquid metal heat transfer medium, the heat transfer medium is heated to a temperature which provides for the conditions of passivation, and in situ passivation is carried out in two stages, the first of which includes an isothermal passivation mode in conformity with the conditions determined for this stage, and the second mode includes non-isothermal passivation, which is carried out under different conditions, after which the core simulator is removed and the regular core is installed in the place thereof. The method provides for the corrosion-resistance of steel elements in a heavy liquid metal heat transfer medium environment and permits a decrease in the maximum rate of oxygen consumption during the initial period of operation of a nuclear actor.
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 13/08 - Vessels characterised by the materialSelection of materials for pressure vessels
G21C 21/00 - Apparatus or processes specially adapted to the manufacture of reactors or parts thereof
C23C 22/72 - Treatment of iron or alloys based thereon
C23C 22/73 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
G21C 17/022 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators
15.
Nuclear fuel pellet having enhanced thermal conductivity, and preparation method thereof
The invention relates to nuclear physics, and specifically to reactor fuel elements and units thereof, and particularly to the composition of solid ceramic fuel elements based on uranium dioxide, intended for and exhibiting characteristics for being used in variously-purposed nuclear reactors. The result consists in a more reliable, special structure and a simple composition of uranium dioxide without heterogeneous fuel pellet additives, approaching the characteristics of a monocrystal having enhanced, and specifically exceeding reference data, thermal conductivity as temperature increases, and a simple production method thereof. The result is achieved in that pores of between 1 and 5 microns in size are distributed along the perimeters of grains in the micro-structure of each metal cluster in a nuclear fuel pellet, and in that located within the grains are pores which are predominantly nano-sized. In addition, the metal clusters comprise between 0.01 and 1.0 percent by mass. The invention provides for a method of preparing a nuclear fuel pellet, including precipitating metal hydroxides, in two stages, having different pH levels. Uranium metal is melted at a temperature exceeding 1150 DEG C., sintering is carried out in an insignificant amount of liquid phase at a temperature ranging between 1600 and 2200 DEG C. in a hydrogen medium until forming uranium dioxide, the structure of which includes metal clusters dispersed therein. An X-ray photon spectroscope is used for identifying the new structure of the UO2 pellet and the additional U—U chemical bond.
A method for guaranteeing fast reactor core subcriticality under conditions of uncertainty involves, after assembling the reactor core, conducting physical measurements of reactor core subcriticality and comparing the obtained characteristics with design values; then, if there is a discrepancy between the values of the obtained characteristics and the design values, installing adjustable reactivity rods in the reactor at the level of a fuel portion of the reactor core, wherein the level of boron-B10 isotope enrichment of the adjustable reactivity rods is selected to be higher than the level of boron-B10 isotope enrichment of compensating rods of the reactor core. The technical result consists in improving the operating conditions of absorbing elements of a compensating group of rods, eliminating the need for increasing the movement thereof, simplifying monitoring technologies used during production, and simplifying the algorithm for safe reactor control.
G21C 7/06 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section
G21C 7/08 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
G21C 9/02 - Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse
G21C 11/06 - Reflecting shields, i.e. for minimising loss of neutrons
G21C 21/18 - Manufacture of control elements covered by group
G21C 11/00 - Shielding structurally associated with the reactor
The invention relates to energy mechanical engineering and can be used in power installations involving a liquid-metal heat carrier. A mass transfer apparatus including a housing and, provided therein, a flow reaction chamber filled with a solid-phase granulated oxidation agent, and an electric heater positioned in the reaction chamber. The housing of the apparatus is equipped with a repository for reserves of the solid-state granulated oxidation agent, said repository being located below the reaction chamber and being made in the form of a cup having a bottom, said cup being connected to the re-action chamber. The technical result consists in extending the operational duration of the mass transfer apparatus.
B01J 8/02 - Chemical or physical processes in general, conducted in the presence of fluids and solid particlesApparatus for such processes with stationary particles, e.g. in fixed beds
B01J 8/00 - Chemical or physical processes in general, conducted in the presence of fluids and solid particlesApparatus for such processes
The invention relates to nuclear power, and the implementation of the invention increases the safety of the operation of nuclear reactors (NR). The invention can be successfully used in NR with a liquid-metal coolant (LMC), particularly in fast neutron reactors with heavy liquid-metal coolants (HLMC), for example, a eutectic alloy of lead-bismuth or lead. The method is characterised in that the value of the damaging dose of fast neutrons (dpa number) that causes an unacceptable reduction in the plastic properties of steel is determined. Then, when a corresponding value of the reactor energy yield is reached, the direction of the motion of the coolant is changed from the operating direction to the opposite direction. Next, the time period in which the annealing of the core elements is to be carried out is selected, whereupon a temperature, which is no lower than the temperature which provides for the recovery of the plastic properties of the steel in the lower portion of the core over the selected time period, is selected and provided in an annealing mode by means of regulation of the power level. After the selected time period has elapsed, the annealing mode is ended and the direction of the motion of the coolant is changed from the opposite direction back to the operating direction. A nuclear reactor enabling the implementation of the proposed method is also claimed.
Heat exchangers for use in heavy liquid metal coolant mediums that ensure reliable fixation and spacing of heat exchanger tubes. A first embodiment includes one supporting spacer grid having a cylindrical shell and two or more tiers of plates spaced apart at a preset gap, while the width of each plate is parallel to the shell axis. Ends of all plates are fixed to the shell such that plates of any tier are parallel to each other and located at the preset gap. Plates of different tiers are criss-crossed at an angle of 60 degrees along the shell axles and fastened together at the crossing points. Another embodiment includes three dividers which run through the cylinder axis; their ends are connected to the shell and are spaced at an angle of 60 degrees.
The present invention relates to variants of a device for spacing pipes of a heat-exchange apparatus, primarily intended for operating in a heavy liquid metal coolant medium. The utilization thereof provides for a more-reliable fastening of the pipes of a heat-exchange apparatus while simultaneously spacing same. According to a first variant, the device contains at least one support/spacing grid (1), each of which consists of a cylindrical housing (2) and two, three or more tiers of slats (3, 4) which are distanced from one another by a predetermined amount, wherein the width of each slat lies in a plane which is parallel to the axis of the housing, and the ends of all slats are affixed to the housing in such a way that the slats of any tier are spaced, with a preset gap, parallel to one another, wherein the slats of two tiers are crossed at an angle of 60 degrees when viewed along the axis of the housing, and are connected to one another at the location of this crossing. According to a second variant, the device has three section-forming dividers which pass through the axis of the cylinder and are connected by the ends thereof to the housing with a 60-degree shift relative to one another.
A hydrogen detector for gas and fluid media is disclosed. The detector includes a selective membrane and a housing. Within the housing is a potential measuring unit and a ceramic sensing element made of a solid electrolyte. A standard electrode is located within a cavity of the ceramic sensing element and a porous platinum electrode is applied to an external layer of the ceramic sensing element. A potential measuring unit passes through a sealed lead-in at the upper end of the housing and is brought out to the standard electrode. The selective membrane, which is attached to a hole in the end of the lower bushing, is closed with a plug. The cavity limited by the inner surface of the lower bushing, the external part of the bottom of the ceramic sensing element and the inner surfaces of the selective membrane and the plug is leak-tight.
The invention relates to nuclear technology and is intended to provide for controlled reactor startup by bringing a reactor to working capacity after scheduled and unscheduled shutdown. The invention solves the problem of increasing the reliability of a working neutron source by creating additional safety barriers between a coolant and the materials of the active part of the source. The present working neutron source is in the form of a steel casing having disposed therein a capsule containing active elements, namely antimony and beryllium, with a coaxial arrangement of separate antimony and beryllium chambers. The antimony is enclosed in a central casing made of a niobium-based alloy which does not react with antimony during filling and use. The beryllium, in the form of a powder filling, is disposed between the casing of the antimony and the casing of the capsule. The capsule casing is made of ferritic-martensitic grade steel, which is weakly reactive with beryllium. An upper gas reservoir is situated above the capsule and serves as a compensating reservoir space for gaseous fission products. The lower end of the capsule rests on a reflector and a lower gas reservoir. The gas reservoirs, reflector and washers are made of ferritic-martensitic grade steel.
A sensor for sensing hydrogen in liquid and gaseous media comprises a selective membrane and a housing, a ceramic sensor element, a reference electrode, a porous platinum electrode, a sealed inlet and a potential measuring device. The ceramic sensor element is configured in the form of a cylinder with a bottom. The outer cylindrical surface of the ceramic sensor element is hermetically connected to the inner side surface of the housing. The reference electrode is situated inside an inner cavity of the ceramic sensor element. The outer part of the bottom of the ceramic sensor element is coated with a porous platinum electrode layer. The end of the central core of the potential measuring device extends into the body of the reference electrode. A lower bushing is provided in the form of a tube, which is connected to the lower part of the housing. To the lower end of said bushing there is attached a selective membrane, the free end of which is hermetically sealed with a plug, wherein a cavity delimited by the inner surface of the lower bushing, the outer part of the bottom of the ceramic sensor element and the inner surfaces of the selective membrane and the plug is hermetic. An upper bushing is mounted at the top of the potential measuring device, and an annular cavity between the inner surface of the wall of the upper bushing and the outer surface of the potential measuring device is filled with a glass ceramic.
The invention relates to the field of mechanical engineering, and more particularly to methods, applicable in the nuclear power industry, for diagnosing fast neutron reactors. The aim of the invention is to create an effective method and system for diagnosing a lead-bismuth fast reactor coolant. This aim is achieved and the technical problem is solved in that a method for diagnosing a lead-bismuth fast reactor coolant includes a process of measuring coolant parameters, wherein a monitoring and control procedure includes measuring oxygen activity in a lead-bismuth coolant in the central buffer tank of a reactor unit; measuring oxygen activity in the lead-bismuth coolant in a peripheral buffer tank of the reactor unit; taking a control measurement of oxygen activity in the lead-bismuth coolant in a "cold" phase using a standby sensor which, most of the time, maintains its parameters outside of the coolant and is immersed in the lead-bismuth coolant only during the measuring time; controlling a mass transfer apparatus for introducing dissolved oxygen into the coolant in order to provide for given oxygen conditions therein; and controlling post-combustion and a gas disperser for purifying the coolant of hydrogen.
G21C 17/025 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators for monitoring liquid metal coolants
G21C 19/30 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products
The invention relates to nuclear technology and is intended to provide for controlled reactor startup by bringing a reactor to working capacity after scheduled and unscheduled shutdown. The invention solves the problem of increasing the reliability of a working neutron source by creating additional safety barriers between a coolant and the materials of the active part of the source. The present working neutron source is in the form of a steel casing having disposed therein a capsule containing active elements, namely antimony and beryllium, with a coaxial arrangement of separate antimony and beryllium chambers. The antimony is enclosed in a central casing made of a niobium-based alloy which does not react with antimony during filling and use. The beryllium, in the form of a powder filling, is disposed between the casing of the antimony and the casing of the capsule. The capsule casing is made of ferritic-martensitic grade steel, which is weakly reactive with beryllium. An upper gas reservoir is situated above the capsule and serves as a compensating reservoir space for gaseous fission products. The lower end of the capsule rests on a reflector and a lower gas reservoir. The gas reservoirs, reflector and washers are made of ferritic-martensitic grade steel.
The present device relates to measuring technology and can be used in the energy industry, metallurgy and the chemical industry for determining the concentration of hydrogen in gaseous media over a wide range of temperatures and pressures. A sensor for sensing hydrogen in gaseous media comprises a working element which, by means of a seal, fits snugly against the upper part of a housing of the sensor. Additional hermeticity is provided by a nut. The lower part of the housing of the sensor is delimited by insulation, which provides close contact with a heater that provides the temperature conditions of a working medium supplied to a hydrogen-permeable membrane of a water-steam chamber. Via a platinum measuring electrode, which lies snugly against the lower part of a ceramic sensor element that is hermetically connected by means of a glass ceramic to a metallic housing of the sensor element, the disturbance caused by a measurement flow is transmitted to a central core of a potential measuring device. A reference electrode is situated inside an inner cavity of the ceramic sensor element. The outer part of the bottom of the ceramic sensor element is coated with a porous platinum electrode layer. The end of the central core of the potential measuring device extends into the body of the reference electrode. The invention achieves the technical result of increasing the service life and operating reliability of a hydrogen sensor over a wide range of parameters of a working medium by providing for the hermeticity of the inner cavity of the ceramic sensor element and the stability of the temperature conditions of the working medium at the inlet to the sensor.
The invention relates to the field of nuclear power and can be used for ridding a liquid metal medium, for example a eutectic lead-bismuth alloy (45% Pb, 55% Bi), of suspended impurities. The proposed device comprises a housing (1) with an inlet fitting (2) and outlet fittings (3). Inside the housing there is a core with a casing (4) and with grilles (5) and (6) at the ends. An inside cavity of the core is filled with a filtering material. The filtering material is in the form of coarse purification sections (7) and fine purification sections (8), arranged in the direction of flow. The sections are separated from one another by sleeves (10). Each of the sections consists of one or more closely packed layers of a filtering material (9). Furthermore, the coarse purification sections (7) have a high porosity, the fibres of the filtering material having a size of from 40 to 60 μm. The fine purification sections (8) have a lower porosity and a fibre size of from 10 to 40 μm. The ratio of the number of fine and coarse purification sections in the device is selected within a range of from 3:1 to 10:1, taking into consideration the ratio in the liquid metal medium of the mass concentrations of micron or submicron particles and relatively large particles with a diameter greater than or equal to 10 μm. The thickness of one layer in both the coarse and fine purification sections is from 3.0 to 7.0 mm. The technical result of the device is that of more effectively purifying a liquid metal medium of suspended impurities, and of increasing the service life.
The method for the long-term storage of waste nuclear fuel of a nuclear reactor consists in that, first, prior to the waste fuel assembly of the nuclear reactor being disposed in a steel case and the latter being hermetically sealed with a cover, a material which is chemically inert in relation to the material of the casing of the fuel elements of the waste fuel assemblies, to the material of the body of the case, to air and to water, is arranged in the steel case, the steel case is mounted in a heating device, the steel case is heated along with the material arranged in said steel case until said material passes into a liquid state, and then the waste fuel assembly which has been extracted from the nuclear reactor is arranged in the steel case in such a way that the fuel part of the fuel elements of the waste fuel assemblies is lower than the level of the liquid material in the steel case, the waste fuel assembly is fixed in this position, and the case is hermetically sealed by the cover, whereupon the hermetically sealed steel case is extracted from the heating device and mounted in a storage facility which is cooled by atmospheric air. This technical solution makes it possible to ensure long-term safe storage of waste fuel assemblies of a nuclear reactor in storage facilities with cooling using atmospheric air, in particular with natural circulation of atmospheric air, and also to transport the waste fuel assemblies to a factory for processing so as to ensure an increased level of safety.
?A pump for pumping smelt comprises a body (1) in which a shaft (4) which is connectable to a drive is mounted on an upper plain bearing (2) and on a lower radial plain bearing (3), with a working wheel (5) secured on the shaft (4). The lower radial plain bearing (3) comprises a rotor part (15) and a stator part (16). The rotor part (15) is in the form of two slit bushings (17) which are secured on the shaft (4), and the stator part (16) is in the form of two slit bushings (18) which are secured in a band (19) coaxially with respect to the shaft (4). The bushings (17) and (18) are respectively secured by flat rings (24) and (33) and comprise cylinder segments (20), (28) which are arranged equidistantly around the circumference and are respectively disposed in a cylindrical depression (21) of the shaft and in a cylindrical depression (29) of the band (19) and are secured in the radial direction by conical clamping rings (22), (30) and in the axial direction by spring-loaded rings (23), (31). The pump has a design of the lower radial bearing that is simpler to manufacture, and scratches are prevented in the bearing, and this in turn provides for increased reliability of the pump during operation.
F04D 7/06 - Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metal
A pump for pumping smelt comprises a body (1) in which a shaft (4) which is connectable to a drive is mounted on an upper plain bearing (2) and on a lower radial plain bearing (3), with a working wheel (5) secured on the shaft (4). The lower radial plain bearing (3) comprises a rotor part (15) and a stator part (16). The rotor part (15) is in the form of two slit bushings (17) which are secured on the shaft (4), and the stator part (16) is in the form of two slit bushings (18) which are secured in a band (19) coaxially with respect to the shaft (4). The bushings (17) and (18) are respectively secured by flat rings (24) and (33) and comprise cylinder segments (20), (28) which are arranged equidistantly around the circumference and are respectively disposed in a cylindrical depression (21) of the shaft and in a cylindrical depression (29) of the band (19) and are secured in the radial direction by conical clamping rings (22), (30) and in the axial direction by spring-loaded rings (23), (31). The pump has a design of the lower radial bearing that is simpler to manufacture, and scratches are prevented in the bearing, and this in turn provides for increased reliability of the pump during operation.
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
F04D 7/06 - Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metal
The patent discloses method and control system for gas injection into the coolant of a nuclear reactor plant. The method includes the following steps: gas to be injected into the coolant is supplied from the gas system to the above-coolant space; gas is injected into the gas system from the above-coolant space. Technical result: prevention of reuse of contaminated gas.=
Disclosed are a method and a system for controlling a gas system. The method contains the following steps: checking, prior to the supply of oxygen, whether hydrogen is being supplied to a reactor and/or ceasing the supply of hydrogen; supplying oxygen if hydrogen is not being supplied to the reactor; checking, prior to the supply of hydrogen, whether oxygen is being supplied to the reactor and/or ceasing the supply of oxygen; supplying hydrogen if oxygen is not being supplied to the reactor. Technical result: preventing the simultaneous supply of hydrogen and oxygen to a reactor, preventing the formation of oxyhydrogen, and increasing the safety and service life of a reactor facility.
Disclosed are a method and system for controlling the introduction of gas into a coolant of a nuclear reactor installation. The method includes the following steps: feeding gas, intended for being introduced into a coolant, from a gas system into a space above a coolant; introducing the gas into the coolant; removing gas from the space above the coolant into the gas system. Technical result: preventing the reuse of contaminated gas.
Disclosed are a method and a system for regulating the concentration of oxygen and hydrogen in a coolant of a reactor facility comprising a reactor, a coolant located in said reactor, a gas system, a mass transfer apparatus, a disperser and a sensor for sensing the oxygen concentration in the coolant. The method includes the following steps, carried out by the system: evaluating the oxygen concentration; comparing the oxygen concentration with upper and lower permissible values; in the event that the oxygen concentration is greater than the upper permissible value, checking whether the mass transfer apparatus is active and/or deactivating same and/or transmitting a signal about the need to deactivate same, and supplying a hydrogen-containing gas from the gas system to the reactor and/or activating the disperser; in the event that the oxygen concentration is less than the lower permissible value, checking whether the disperser is deactivated and/or the supply of a hydrogen-containing gas to the reactor has ceased, and/or deactivating the disperser and/or ceasing the supply of hydrogen-containing gas, and/or transmitting a signal about the need to deactivate the disperser and/or cease the supply of hydrogen-containing gas, and/or supplying a gas which does not contain hydrogen, and activating the mass transfer apparatus. Technical result: preventing the simultaneous supply of hydrogen and oxygen to a coolant, and increasing the safety and service life of a reactor facility.
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
G21C 19/307 - Arrangements for introducing fluent material into the reactor coreArrangements for removing fluent material from the reactor core with continuous purification of circulating fluent material, e.g. by extraction of fission products specially adapted for liquids
35.
PROCÉDÉ POUR AUGMENTER LA RÉSISTANCE D'ARTICLES À LA CORROSION
Un procédé pour augmenter la résistance d'acier à la corrosion dans un circuit à agent caloporteur en métal lourd en fusion consiste à nettoyer l'article des salissures extérieures et à effectuer un traitement mécanique des surfaces en contact avec l'agent caloporteur. La surface de l'article est polie jusqu'à atteindre une granularité de Ra<0,2 et une profondeur d'au moins 15 micromètres. La couche de surface de grains est principalement orientée dans une direction et suivant une ligne en tangente à la surface, la valeur moyenne des grains orientés de la couche de surface étant d'au moins 50% de leur quantité globale. Après le polissage on effectue la passivation de la surface jusqu'à obtenir une épaisseur du film d'oxyde d'au moins 1,5 micromètre. En outre, la passivation du circuit s'effectue dans un milieu d'agent caloporteur en métal lourd en fusion à activité thermodynamique de l'oxygène comprise entre 10-6 et 10-5; hors circuit, elle s'effectue par de la vapeur d'eau haute température pendant quelques dizaines de minutes ou heures à une température supérieure à 400° C.
C23C 22/00 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
C21D 7/06 - Modifying the physical properties of iron or steel by deformation by cold working of the surface by shot-peening or the like
36.
METHOD AND DEVICE FOR CONTROL OF OXYGEN CONCENTRATION IN THE REACTOR PLANT AND NUCLEAR REACTOR PLANT
The method and system for control of oxygen concentration in the coolant of a reactor plant including a reactor, coolant in the reactor, gas system, rnass-exchange apparatus, disperser and an oxygen sensor in the coolant have been disclosed. The method includes the following steps implemented by the system: estimation of the oxygen concentration; comparison of the oxygen concentration with the permissible value; if the oxygen concentration is reduced, comparison of the reduction value anthor rate with the corresponding threshold value; if the reduction value and\or rate of oxygen concentration is below the threshold value, activation of the mass-exchange apparatus; if the reduction value and/or rate of oxygen concentration is above the corresponding threshold value, supply of oxygen-containing gas from the gas system to the near-coolant space and/or activation of the disperser. Technical result: improvement of controllability of oxygen concentration in coolant, enhancement of safety and extension of reactor plant operating life.
G21C 17/025 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators for monitoring liquid metal coolants
37.
NUCLEAR POWER PLANT AND DEVICE FOR FEEDING A COVER GAS INTO THE PLANT
The invention relates to nuclear power engineering and can be used in power plants with lead-containing liquid metal coolants, and particularly in fast neutron reactors. The invention makes it possible to increase the operating safety of a nuclear power plant. For this purpose, a nuclear power plant is proposed which is characterized in that it includes: a reactor vessel with a core and a peripheral part; a shaft with an active region, said shaft being situated in the core of the vessel; a liquid metal coolant, at least one circulation pump for enabling the circulation of said liquid metal coolant, and at least one steam generator, situated in the peripheral part of the vessel; a cavity with a cover gas, said cavity being situated above the coolant; and at least one cover gas feed device, situated in the peripheral part of the vessel above the top edge of the steam generator in the intake region of the circulation pump, comprising an intake part and a working part, wherein the intake part is situated in the aforementioned cover gas cavity and has openings in its top part, and the working part is situated below the surface level of the liquid metal coolant.
The invention relates to nuclear power engineering and can be used in power plants with lead-containing liquid metal coolants, and particularly in fast neutron reactors. The invention makes it possible to increase the operating safety of a nuclear power plant. For this purpose, a nuclear power plant is proposed which is characterized in that it includes: a reactor vessel with a core and a peripheral part; a shaft with an active region, said shaft being situated in the core of the vessel; a liquid metal coolant, at least one circulation pump for enabling the circulation of said liquid metal coolant, and at least one steam generator, situated in the peripheral part of the vessel; a cavity with a cover gas, said cavity being situated above the coolant; and at least one cover gas feed device, situated in the peripheral part of the vessel above the top edge of the steam generator in the intake region of the circulation pump, comprising an intake part and a working part, wherein the intake part is situated in the aforementioned cover gas cavity and has openings in its top part, and the working part is situated below the surface level of the liquid metal coolant.
Disclosed are a method and a system for regulating the concentration of oxygen in a coolant of a reactor facility comprising a reactor, a coolant located in said reactor, a gas system, a mass transfer apparatus, a disperser and a sensor for sensing the oxygen concentration in the coolant. The method includes the following steps, carried out by the system: evaluating the oxygen concentration; comparing the oxygen concentration with a permissible value; evaluating the change in oxygen concentration; comparing, in the event of a decrease in concentration, the size and/or rate of the decrease against corresponding threshold values; activating a mass transfer apparatus in the event that the size and/or rate of the decrease in oxygen concentration is greater than the threshold value; feeding an oxygen-containing gas from a gas system into the space around the coolant and/or activating a disperser in the event that the size and/or rate of the decrease in oxygen concentration is less than the threshold value. Technical result: rendering regulation of the concentration of oxygen in a coolant more controllable, and increasing the safety and service life of a reactor facility.
G21C 17/025 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators for monitoring liquid metal coolants
40.
METHOD OF EXTRACTING PLUG AND REMOVABLE UNIT WHEN REFUELING NUCLEAR REACTOR
?The invention relates to atomic technology, and specifically to a method for extracting a plug and a removable unit of a fast neutron reactor having a heavy liquid-metal coolant. The technical result consists in extracting, from a nuclear reactor, a plug and a removable unit, without fuel assemblies, with the help of a set of refueling instruments in radiationally-safe conditions. The method for extracting a plug and a removable unit when refueling a nuclear reactor consists in first installing the refueling instruments, then removing the plug from a reactor monoblock, transporting and positioning the plug in a shaft for the plug, removing the removable unit, and transporting and positioning same in a shaft for disassembling the removable unit.
G21C 19/00 - Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
41.
METHOD OF EXTRACTING PLUG AND REMOVABLE UNIT WHEN REFUELING NUCLEAR REACTOR
The invention relates to atomic technology, and specifically to a method for extracting a plug and a removable unit of a fast neutron reactor having a heavy liquid-metal coolant. The technical result consists in extracting, from a nuclear reactor, a plug and a removable unit, without fuel assemblies, with the help of a set of refueling instruments in radiationally-safe conditions. The method for extracting a plug and a removable unit when refueling a nuclear reactor consists in first installing the refueling instruments, then removing the plug from a reactor monoblock, transporting and positioning the plug in a shaft for the plug, removing the removable unit, and transporting and positioning same in a shaft for disassembling the removable unit.
G21C 19/00 - Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
A nuclear reactor with a liquid metal coolant includes a housing having a separating shell disposed therein. In the annular space between the housing and the separating shell are disposed at least one steam generator and at least one pump. Inside the separating shell there is an active region, above which a heat collector is disposed. The heat collector is in communication with the vertically central portion of the steam generator in order to separate a stream of liquid metal coolant into ascending and descending flows. Alternatively, the heat collector is in communication with the upper portion of the steam generator in order to create a counter-flow heat exchange regime. Below the reactor head is an upper horizontal cold collector with an unfilled level of coolant, and below the steam generator is a lower accumulating collector in communication with the upper cold collector.
?A method for the inner-contour passivation of steel surfaces of a nuclear reactor consists in filling a first contour of a nuclear reactor with a liquid metal coolant, introducing a reagent into the liquid metal coolant, said reagent interacting with the material of elements of the first contour, forming a protective film, and heating the liquid metal coolant, having the reagent introduced therein, to a temperature allowing for conditions for forming the protective film. The liquid metal coolant having the reagent introduced therein is kept at said temperature until a continuous protective film is formed on the surface of the material of the elements of the first contour. The liquid metal coolant having reagent introduced therein is heated by means of the friction thereof against rotating vanes of a vane pump, which is submerged in the liquid metal coolant. The present invention thus provides for a simpler passivation process, a more reliable passivation mode, an increase in the safety thereof and a simpler control over the process of passivation of steel surfaces.
C23C 22/00 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
C23F 11/00 - Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
44.
METHOD FOR INNER-CONTOUR PASSIVATION OF STEEL SURFACES OF NUCLEAR REACTOR
A method for the inner-contour passivation of steel surfaces of a nuclear reactor consists in filling a first contour of a nuclear reactor with a liquid metal coolant, introducing a reagent into the liquid metal coolant, said reagent interacting with the material of elements of the first contour, forming a protective film, and heating the liquid metal coolant, having the reagent introduced therein, to a temperature allowing for conditions for forming the protective film. The liquid metal coolant having the reagent introduced therein is kept at said temperature until a continuous protective film is formed on the surface of the material of the elements of the first contour. The liquid metal coolant having reagent introduced therein is heated by means of the friction thereof against rotating vanes of a vane pump, which is submerged in the liquid metal coolant. The present invention thus provides for a simpler passivation process, a more reliable passivation mode, an increase in the safety thereof and a simpler control over the process of passivation of steel surfaces.
C23C 22/00 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
C23F 11/00 - Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
45.
FAST NEUTRON REACTOR AND NEUTRON REFLECTOR BLOCK OF A FAST NEUTRON REACTOR
The invention relates to the field of nuclear engineering, and more particularly to designs for removable neutron reflector blocks for heavy liquid metal-cooled fast neutron reactors. The present fast neutron reactor contains a core consisting of heavy liquid metal-cooled fuel rods, and neutron reflector blocks, disposed around the core, which comprise a steel casing with at least one inlet opening in the side walls thereof above the core boundary, said inlet opening being intended for diverting part of the coolant flow from the space between the blocks into the casing, and at least one vertical pipe mounted in the casing, through which the diverted coolant flow, which has passed through the upper and lower boundaries of the core, enters the bottom part of the casing; also, on the outer side of the casing, above the inlet opening, there is mounted a throttling device for creating hydraulic resistance to the coolant flow in the space between the blocks. The technical result is an increase in the operating safety and the performance of a fast neutron reactor and a reduction in the heat exchange surface of the steam generator.
G21C 11/06 - Reflecting shields, i.e. for minimising loss of neutrons
G21C 15/10 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from reflector or thermal shield
46.
FAST NEUTRON REACTOR AND NEUTRON REFLECTOR BLOCK OF A FAST NEUTRON REACTOR
The invention relates to the field of nuclear engineering, and more particularly to designs for removable neutron reflector blocks for heavy liquid metal-cooled fast neutron reactors. The present fast neutron reactor contains a core consisting of heavy liquid metal-cooled fuel rods, and neutron reflector blocks, disposed around the core, which comprise a steel casing with at least one inlet opening in the side walls thereof above the core boundary, said inlet opening being intended for diverting part of the coolant flow from the space between the blocks into the casing, and at least one vertical pipe mounted in the casing, through which the diverted coolant flow, which has passed through the upper and lower boundaries of the core, enters the bottom part of the casing; also, on the outer side of the casing, above the inlet opening, there is mounted a throttling device for creating hydraulic resistance to the coolant flow in the space between the blocks. The technical result is an increase in the operating safety and the performance of a fast neutron reactor and a reduction in the heat exchange surface of the steam generator.
G21C 11/06 - Reflecting shields, i.e. for minimising loss of neutrons
G21C 15/10 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from reflector or thermal shield
47.
NUCLEAR FUEL PELLET HAVING ENHANCED THERMAL CONDUCTIVITY, AND PREPARATION METHOD THEREOF
The invention relates to nuclear physics, and specifically to reactor fuel elements and units thereof, and particularly to the composition of solid ceramic fuel elements based on uranium dioxide, intended for and exhibiting characteristics for being used in variously-purposed nuclear reactors. The result consists in a more reliable, special structure and a simple composition of uranium dioxide without heterogeneous fuel pellet additives, approaching the characteristics of a monocrystal having enhanced, and specifically exceeding reference data, thermal conductivity as temperature increases, and a simple production method thereof. The result is achieved in that pores of between 1 and 5 microns in size are distributed along the perimeters of grains in the micro-structure of each metal cluster in a nuclear fuel pellet, and in that located within the grains are pores which are predominantly nano-sized. In addition, the metal clusters comprise between 0.01 and 1.0 percent by mass. The invention provides for a method of preparing a nuclear fuel pellet, including precipitating metal hydroxides, in two stages, having different pH levels. Uranium metal is melted at a temperature exceeding 1150°C, sintering is carried out in an insignificant amount of liquid phase at a temperature ranging between 1600 and 2200°C in a hydrogen medium until forming uranium dioxide, the structure of which includes metal clusters dispersed therein. An X-ray photon spectroscope is used for identifying the new structure of the UO2 pellet and the additional U-U chemical bond.
Disclosed is a hydrogen igniter for igniting hydrogen contained in a gaseous medium, said hydrogen igniter comprising a housing with openings for the supply and discharge of a gaseous medium, and a filler in the form of bismuth oxide and/or lead oxide, disposed inside the housing. Also disclosed are a system for purifying a gaseous medium of hydrogen having such a hydrogen igniter, and a method for the repeated use of such a system. The igniter and the system can be used in a nuclear reactor facility.
A nuclear fuel pellet with enhanced thermal conductivity is provided. The nuclear fuel pellet has a pellet structure of a pressed and sintered uranium dioxide powder, wherein the pellet structure is made up of evenly distributed pores along grain boundaries and inside grains of the pressed and sintered powder, and where the grains include nanopores and metal clusters of chemical compounds of uranium with a valence of 0 and 2+.
Disclosed is a catalytic chamber for igniting hydrogen contained in a gaseous medium, said catalytic chamber comprising a housing with openings for the supply and discharge of a gaseous medium, and a filler in the form of bismuth oxide and/or lead oxide, disposed inside the housing. Also disclosed are a system for dehydrogenating a gaseous medium having such a catalytic chamber, and a method for the repeated use of such a system. The catalytic chamber and the system can be used in a nuclear reactor facility.
An improvement in the performance characteristics of fuel rods and assemblies as a result of the long-term resistance of the cladding in the environment of a heavy liquid metal coolant such as lead or a eutectic of lead and bismuth is disclosed. The fuel rod cladding for a heavy liquid metal cooled reactor is in the form of a weldless tubular element with helically-coiled fins disposed on the outer surface of said element, which is made from a ferritic-martensitic chromium-silicon steel with a minimum ferrite grain size of 7 on the GOST 5639 scale, wherein each fin has an opening angle of from 22 degrees to 40 degrees and the cross-section of the fin is in the shape of a trapezoid with rounded corners at the top of the trapezoid and smooth corners at the base of the trapezoid. Also disclosed are a fuel rod comprising the above cladding, and a fuel assembly.
The invention relates to the field of nuclear engineering and can be used in the manufacture of fuel rods and fuel assemblies for heavy liquid metal cooled reactors, and also in the manufacture of fuel rod simulators for use in irradiation devices designed to test the operability of real fuel assemblies. The present cladding of a fuel rod for a heavy liquid metal cooled reactor is in the form of a weldless tubular element with helically-coiled fins disposed on the outer surface of said element, which is made from a ferritic-martensitic chromium-silicon steel with a minimum ferrite grain size of 7 on the GOST 5639 scale, wherein each fin has an opening angle of from 22 to 40º (preferably from 30 to 40º) and the cross-section of the fin is in the shape of a trapezoid with rounded corners at the top of the trapezoid and smooth corners at the base of the trapezoid. Also disclosed are a fuel rod comprising the above cladding, and a fuel assembly. The technical result of the invention is an improvement in the performance characteristics of fuel rods and assemblies as a result of the long-term resistance of the cladding in the environment of a heavy liquid metal coolant such as lead or a eutectic of lead and bismuth.
G21C 3/08 - CasingsJackets provided with external means to promote heat-transfer, e.g. fins, baffles, corrugations
G21C 3/30 - Assemblies of a number of fuel elements in the form of a rigid unit
53.
LIQUID METAL COOLED NUCLEAR REACTOR, SYSTEM FOR MONITORING OXYGEN THERMODYNAMIC ACTIVITY IN SUCH REACTORS AND METHOD OF MONITORING OXYGEN THERMODYNAMIC ACTIVITY
The invention relates to nuclear power engineering and can be used in power plants with lead-containing liquid metal coolants, and particularly in fast neutron reactors. The proposed nuclear reactor and the method and system for monitoring the thermodynamic activity of oxygen in a coolant with continuously operational oxygen thermodynamic activity sensors located in the "hot" and "cold" zones of the reactor vessel and an additional intermittently operational sensor make it possible to carry out continuous monitoring in order to maintain set oxygen thermodynamic activity values in a liquid metal coolant under any prescribed operating regime.
G21C 17/025 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators for monitoring liquid metal coolants
54.
LIQUID METAL COOLED NUCLEAR REACTOR, SYSTEM FOR MONITORING OXYGEN THERMODYNAMIC ACTIVITY IN SUCH REACTORS AND METHOD FOR MONITORING OXYGEN THERMODYNAMIC ACTIVITY
The invention relates to nuclear power engineering and can be used in power plants with lead-containing liquid metal coolants, and particularly in fast neutron reactors. The proposed nuclear reactor and the method and system for monitoring the thermodynamic activity of oxygen in a coolant with continuously operational oxygen thermodynamic activity sensors located in the "hot" and "cold" zones of the reactor vessel and an additional intermittently operational sensor make it possible to carry out continuous monitoring in order to maintain set oxygen thermodynamic activity values in a liquid metal coolant under any prescribed operating regime.
G21C 17/025 - Devices or arrangements for monitoring coolant or moderator for monitoring liquid coolants or moderators for monitoring liquid metal coolants
Systems for controlling and protecting nuclear reactors are disclosed. A drive of an emergency safety rod of a nuclear reactor includes an electric drive, a reduction gear, and a rack-and-pinion gear. The electric drive contains a contactless electric motor based on permanent magnets, which is installed in its housing with a motor rotor position sensor, and a reduction gear. A toothed rack is installed along the axis of the rack-and-pinion gear in order to provide for the reciprocating motion of a system absorber rod connected thereto. A toothed electromagnetic clutch having a contactless current supply is installed on an inner shaft of the rack-and-pinion gear, enabling the rigid and simultaneous mechanical coupling of half-couplings, and the drive contains a reverse-motion coupling, a rack-separation spring and toothed rack position sensors. The invention makes it possible to reduce the time necessary for adding negative reactivity to a nuclear reactor core.
?A method for guaranteeing fast reactor core subcriticality under conditions of uncertainty involves, after assembling the reactor core, conducting physical measurements of reactor core subcriticality and comparing the obtained characteristics with design values; then, if there is a discrepancy between the values of the obtained characteristics and the design values, installing adjustable reactivity rods in the reactor at the level of a fuel portion of the reactor core, wherein the level of boron-B10 isotope enrichment of the adjustable reactivity rods is selected to be higher than the level of boron-B10 isotope enrichment of compensating rods of the reactor core. The technical result consists in improving the operating conditions of absorbing elements of a compensating group of rods, eliminating the need for increasing the movement thereof, simplifying monitoring technologies used during production, and simplifying the algorithm for safe reactor control.
G21C 7/08 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
57.
METHOD FOR GUARANTEEING FAST REACTOR CORE SUBCRITICALITY UNDER CONDITIONS OF UNCERTAINTY REGARDING THE NEUTRON-PHYSICAL CHARACTERISTICS THEREOF
A method for guaranteeing fast reactor core subcriticality under conditions of uncertainty involves, after assembling the reactor core, conducting physical measurements of reactor core subcriticality and comparing the obtained characteristics with design values; then, if there is a discrepancy between the values of the obtained characteristics and the design values, installing adjustable reactivity rods in the reactor at the level of a fuel portion of the reactor core, wherein the level of boron-B10 isotope enrichment of the adjustable reactivity rods is selected to be higher than the level of boron-B10 isotope enrichment of compensating rods of the reactor core. The technical result consists in improving the operating conditions of absorbing elements of a compensating group of rods, eliminating the need for increasing the movement thereof, simplifying monitoring technologies used during production, and simplifying the algorithm for safe reactor control.
G21C 7/08 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
The invention relates to nuclear technology, and specifically to systems for controlling and protecting nuclear reactors. A drive of an emergency safety rod of a nuclear reactor includes an electric drive, a reduction gear, and a rack-and-pinion gear. The electric drive contains a contactless electric motor based on permanent magnets, which is installed in the housing of the electric drive with a motor rotor position sensor, and a reduction gear for changing the rate of rotation of the electric drive. A toothed rack is installed along the axis of the rack-and-pinion gear in order to provide for the reciprocating motion of a system absorber rod connected thereto. A toothed electromagnetic clutch having a contactless current supply is installed on an inner shaft of the rack-and-pinion gear, enabling the rigid and simultaneous mechanical coupling of half-couplings, and the drive contains a reverse-motion coupling, a rack-separation spring and toothed rack position sensors. The invention makes it possible to reduce the time necessary for adding negative reactivity to a nuclear reactor core.
The invention relates to a method for the in situ passivation of steel surfaces. The method consists that a protective film is formed on the surface of the nuclear reactor primary circuit elements by introduction a substance interacting with the material of the primary circuit elements into the coolant, thus forming a protective film, wherein, during installation of the nuclear reactor prior to its filling with the reactor coolant, a core simulator is installed in the place of the standard core, the reactor is filled with a coolant that is heated to temperatures ensuring passivation conditions and then the core simulator is removed and replaced with the standard core. The method provides for the corrosion-resistance of steel elements in a heavy liquid metal heat transfer medium environment and permits a decrease in the maximum rate of oxygen consumption during the initial period of operation of a nuclear reactor.
The invention relates to the field of nuclear technology, and specifically to a method for the in situ passivation of steel surfaces. The method consists in installing, in a position intended for a regular core, a core simulator in the form of a model of the core, which models the shape thereof, the relative position of the core components, and also the mass characteristics thereof; next, the reactor is filled with a heavy liquid metal heat transfer medium, the heat transfer medium is heated to a temperature which provides for the conditions of passivation, and in situ passivation is carried out in two stages, the first of which includes an isothermal passivation mode in conformity with the conditions determined for this stage, and the second mode includes non-isothermal passivation, which is carried out under different conditions, after which the core simulator is removed and the regular core is installed in the place thereof. The method provides for the corrosion-resistance of steel elements in a heavy liquid metal heat transfer medium environment and permits a decrease in the maximum rate of oxygen consumption during the initial period of operation of a nuclear reactor.
The invention relates to energy mechanical engineering and can be used in power installations involving a liquid-metal heat carrier. A mass transfer apparatus including a housing and, provided therein, a flow reaction chamber filled with a solid-phase granulated oxidation agent, and an electric heater positioned in the reaction chamber. The housing of the apparatus is equipped with a repository for reserves of the solid-state granulated oxidation agent, said repository being located below the reaction chamber and being made in the form of a cup having a bottom, said cup being connected to the re-action chamber. The technical result consists in extending the operational dura-tion of the mass transfer apparatus.
The invention relates to energy mechanical engineering and can be used in power installations involving a liquid-metal heat carrier. A mass transfer apparatus including a housing and, provided therein, a flow reaction chamber filled with a solid-phase granulated oxidation agent, and an electric heater positioned in the reaction chamber. The housing of the apparatus is equipped with a repository for reserves of the solid-state granulated oxidation agent, said repository being located below the reaction chamber and being made in the form of a cup having a bottom, said cup being connected to the reaction chamber. The technical result consists in extending the operational duration of the mass transfer apparatus.
The method for the long-term storage of waste nuclear fuel of a nuclear reactor consists in that, first, prior to the waste fuel assembly of the nuclear reactor being disposed in a steel case and the latter being hermetically sealed with a cover, a material which is chemically inert in relation to the material of the casing of the fuel elements of the waste fuel assemblies, to the material of the body of the case, to air and to water, is arranged in the steel case, the steel case is mounted in a heating device, the steel case is heated along with the material arranged in said steel case until said material passes into a liquid state, and then the waste fuel assembly which has been extracted from the nuclear reactor is arranged in the steel case in such a way that the fuel part of the fuel elements of the waste fuel assemblies is lower than the level of the liquid material in the steel case, the waste fuel assembly is fixed in this position, and the case is hermetically sealed by the cover, whereupon the hermetically sealed steel case is extracted from the heating device and mounted in a storage facility which is cooled by atmospheric air. This technical solution makes it possible to ensure long-term safe storage of waste fuel assemblies of a nuclear reactor in storage facilities with cooling using atmospheric air, in particular with natural circulation of atmospheric air, and also to transport the waste fuel assemblies to a factory for processing so as to ensure an increased level of safety.
The method for the long-term storage of waste nuclear fuel of a nuclear reactor consists in that, first, prior to the waste fuel assembly of the nuclear reactor being disposed in a steel case and the latter being hermetically sealed with a cover, a material which is chemically inert in relation to the material of the casing of the fuel elements of the waste fuel assemblies, to the material of the body of the case, to air and to water, is arranged in the steel case, the steel case is mounted in a heating device, the steel case is heated along with the material arranged in said steel case until said material passes into a liquid state, and then the waste fuel assembly which has been extracted from the nuclear reactor is arranged in the steel case in such a way that the fuel part of the fuel elements of the waste fuel assemblies is lower than the level of the liquid material in the steel case, the waste fuel assembly is fixed in this position, and the case is hermetically sealed by the cover, whereupon the hermetically sealed steel case is extracted from the heating device and mounted in a storage facility which is cooled by atmospheric air. This technical solution makes it possible to ensure long-term safe storage of waste fuel assemblies of a nuclear reactor in storage facilities with cooling using atmospheric air, in particular with natural circulation of atmospheric air, and also to transport the waste fuel assemblies to a factory for processing so as to ensure an increased level of safety.
A nuclear reactor with a liquid metal coolant includes a housing having a separating shell disposed therein. In the annular space between the housing and the separating shell are disposed at least one steam generator and at least one pump. Inside the separating shell there is an active region, above which a heat collector is disposed. The heat collector is in communication with the vertically central portion of the steam generator in order to separate a stream of liquid metal coolant into ascending and descending flows. Alternatively, the heat collector is in communication with the upper portion of the steam generator in order to create a counter-flow heat exchange regime. Below the reactor head is an upper horizontal cold collector with an unfilled level of coolant, and below the steam generator is a lower accumulating collector in communication with the upper cold collector.
The present nuclear reactor with a liquid metal coolant comprises a housing (1) having a separating shell (6) disposed therein. In the annular space (5) between the housing and the separating shell are disposed at least one steam generator (3) and at least one pump (4). Inside the separating shell (6) there is an active region (2), above which a heat collector (8) is disposed which is in communication with the vertically central portion of the steam generator (3) in order to separate a stream of liquid metal coolant into ascending and descending flows, or the heat collector (8) is in communication with the upper portion of the steam generator in order to create a counter-flow heat exchange regime. Below the reactor head is an upper horizontal cold collector (10) with an unfilled level of coolant, and below the steam generator (3) is a lower accumulating collector (11) in communication with the upper cold collector (10). The inlet of the pump (4) is connected to the upper cold collector (10), and the outlet of the pump (4) is connected to a lower annular pressure collector (12), wherein collectors (11) and (12) are separated by a horizontal partition (13), and collector (12) is in communication with a distributing collector (15) of the active region.
A nuclear reactor comprising a housing having disposed therein an active region that contains a bundle of rod-type fuel elements enclosed in a tubular shell and submerged in a primary coolant that circulates between the active region and at least one heat exchanger. In order to reduce the level of pressure of gaseous fission fragments accumulating below the fuel element shell and to enable the most uniform possible distribution of the velocity field of the primary coolant at the inlet to the active part of the fuel elements, said fuel elements are provided in their upper parts with active portions, which are filled with fuel, and hollow working portions, which are situated below said active portions.
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