Case superheating channel boiling water-to-water nuclear reactor
Usage: in nuclear engineering. Case superheating channel boiling water-to-water nuclear reactor designed in the form of power tubes, which are installed in the shell. Between the pipe and the ring formed by the annular gap, which contains a heat insulating porous layer made of a material with low absorption cross section for neutrons and is sealed on the ends. Effect: reduce the flow of thermal energy from the steam inside the power tubes to the water surrounding the hull from the outside, due to the increase in thermal resistance, i.e., improving the insulating properties of the hull superheating channel. 7 C.p. f-crystals, 1 Il.The invention relates to nuclear engineering, and more specifically to the buildings superheating channels boiling water-to-water nuclear reactor.The closest to the essential features of the invention is the body superheating channel boiling water-to-water nuclear reactor, made in the form of power tubes (G. N. Ushakov. Technological channels and fuel elements of nuclear reactors. M: Energoizdat, 1981, S. 109, Fig.2.16).A disadvantage of the known case europeregio coolant, surrounding the outer wall of the power tubes, when the steam temperature exceeds the saturation temperature of water outside the pipe. The presence of the vapor phase in the ambient water will cause deterioration of the neutron-physical environment near the canal, and the boiling of water on the outer surface of the power tubes, which will take place in intermittent water and steam volumes moderator will lead to neutron-physical instability, violation of the terms of maintaining the neutron balance and to the deterioration of nuclear reactor regulation in General.The present invention is to create superheating channel, the use of which will eliminate the possibility of boiling water (moderator) and, as consequence, increase of neutron-physical stability of boiling water-to-water nuclear reactor.The technical result of the present invention is to reduce the flow of thermal energy from the steam inside the power tubes to the water surrounding the hull from the outside, due to the increase in thermal resistance, i.e., improving the insulating properties of the hull superheating channel.This technical result is achieved by the fact that in the case of paroa pipe installed in the shell, between the pipe and the sides formed by the annular gap, which contains a heat insulating porous layer made of a material with low absorption cross section for neutrons and is sealed on the ends.In addition, as a material of the heat insulating layer used zirconium oxide or aluminum oxide containing not more than 0.3% of impurity oxide of hafnium.In addition, the insulating layer is made in the form of a coating deposited on the outer surface of the power tube or on the inner surface of the shell by plasma spraying.In addition, the porosity of the heat insulating layer is 12-18% of the volume of the layer.In addition, the ends of the shell are connected with the power pipe welds made TIG welding.The invention is illustrated in the drawing, which shows a longitudinal section of the housing superheating channel.Case superheating channel is made in the form of a power tube 1, which is installed in the shell 2 so that between them is formed the annular gap 3, in which is placed a heat insulating porous layer 4 of a material with a low absorption cross section of neutrons, which is due to its porous structure reduces heat flow from the coolant, but the physical characteristics of a nuclear reactor. The annular gap 3 on the ends sealed, for example, by means of a weld obtained electron-beam welding of the ends of the shell 2 with the power pipe 1. The sealing shell and power tubes eliminates the ingress of water into the annular gap 3 and the porous layer 4, which leads to preservation of the integrity of the insulating layer 4 and the shell 2, as otherwise in the presence of water in the annular gap 3 porous layer 4 can crack and crumble, and if water on the hot surface of the power tubes 1 may be boiling and evaporation of water, which will result in a limited volume to a sharp increase in pressure and bulging and rupture of the shell 2. Performing a weld electron beam welding will further reduce heat flow from the fluid inside the power tube 1, the surface of the water due to the formation of the annular gap 3 vacuum because technology electron beam welding provides for its implementation under vacuum. Heat insulating layer 4 may be deposited on the outer surface of the power tube 1 or the inner surface of the shell 2 by means of plasma spraying with a given porosity within 12-18% of the volume of the layer. As a researcher is 0.3% of impurity oxide of hafnium. Shell 2 made of a material identical or similar to power metal pipe 1.When working superheating channel the coolant is water vapor (steam-water mixture) is fed into the cavity of the housing, i.e. in the cavity power pipe 1. The steam passes by the fuel elements, selects allocated in warm and hot. The output from the power tubes 1 steam has a higher temperature than when it entered it. The outside of the shell 2 flowing water with a temperature below the saturation temperature. The differences of temperature of steam flowing inside the power tube 1, and the waters surrounding the outer wall of the shell 2, is the flow of heat from the steam to the water. The total thermal resistance of the package is composed of the power tube 1, the porous insulating layer 4 and the shell 2, allows to significantly reduce the flow of heat, which completely eliminates the possibility of boiling water (vapor phase), and thus preserves the neutron-physical stability of boiling water-to-water nuclear reactor and ensures the regulation of the reactor as a whole.
Claims1. Case superheating channel boiling water-to-water nuclear reacted pipe and shell formed annular gap, which contains a heat insulating porous layer made of a material with low absorption cross section for neutrons and is sealed on the ends.2. The case under item 1, characterized in that the material of the heat insulating layer used zirconium oxide or aluminum oxide containing not more than 0.3 % of impurity oxide of hafnium.3. The case under item 1 or 2, characterized in that the insulating layer is made in the form of a coating deposited on the outer surface of the power tubes.4. The case under item 1 or 2, characterized in that the insulating layer is made in the form of a coating deposited on the inner surface of the shell.5. Building on PP.1, or 2 and 3 or 2 and 4, characterized in that the porosity of the heat insulating layer is 12-18% of the volume of the layer.6. The case under item 3 or 4, characterized in that the coating is performed by plasma spraying.7. Building on PP.1, or 2, or 2 and 3 or 2 and 4 or 3 and 5 or 4 and 5 or 3, 5 and 6, or 4, 5 and 6, characterized in that the ends of the shell are connected with the power pipe welded seam.8. The case under item 7, characterized in that the welded seam is made of electron-beam welding.
FIELD: nuclear power engineering; fuel rods for water-moderated water-cooled reactors.
SUBSTANCE: proposed fuel rod designed for use in water-cooled water-moderated power reactors such as type VVER-1000 reactor has fuel core disposed in cylindrical can. Outer diameter of fuel rod is chosen between 7.00 . 10-3 and 8.79 . 10-3m and fuel core diameter is between 5.82 . 10-3 and 7.32 . 10-3m and mass, between 0.93 and 1.52 kg, fuel core to fuel rod length ratio being between 0.9145 and 0.9483.
EFFECT: reduced linear heat loads and fuel rod depressurization probability, enlarged variation range of reactor power, optimal fuel utilization.
7 cl, 3 dwg
FIELD: nuclear power engineering; manufacture of fuel elements and their claddings.
SUBSTANCE: each weld of cladding and its plug are tested in facility equipped with units for clamping and revolving the claddings, scanning with carriage using weld inspection piezoelectric transducer and piezoelectric transducer for measuring wall thickness in measurement region, immersion bath, ultrasonic pulse generator, ultrasonic pulse receiver, microprocessor, analog-to-digital converter switch, and random-access memory.
EFFECT: enhanced quality of fuel elements and their operating reliability in reactor core.
1 cl, 1 dwg
FIELD: nuclear engineering, in particular, engineering of micro heat-exhausting elements for nuclear reactors.
SUBSTANCE: first layer of micro heat-exhausting element with four-layer protective cover is made of SiC-PyC composition with content of 1,0-10,0 % of mass of silicon carbide with thickness of layer equal to 0,02-0,2 of diameter of fuel micro-sphere, second layer is made of SiC-PyC composition with content of 20,0-45,0 % of mass of silicon carbide with thickness of layer equal to 0,03-0,40 diameter of fuel micro-sphere, third layer is made of silicon carbide, while fourth layer is made of titanium nitride with thickness equal to 0,01-0,08 of diameter of fuel micro-sphere.
EFFECT: increased exploitation resource of nuclear reactor due to increased corrosion resistance and radiation stability.
3 dwg, 1 tbl
FIELD: nuclear power engineering; nuclear reactor fuel microelements covered with four-layer shielding coating.
SUBSTANCE: proposed method involves sequential fluid-bed deposition of coating layers onto fuel microspheres. First low-density pyrocarbon layer is deposited by pyrolysis of acetylene and argon mixture of 50 volume percent concentration at temperature of 1450 °C. 85 - 95 % of second layer is deposited from high-density pyrocarbon by pyrolysis of acetylene and argon mixture of 40.0 - 43,0 volume percent concentration, and of propylene and argon mixture of 30.0 - 27.0 volume percent concentration at temperature of 1300 °C; 5 - 15 % of coating is deposited by pyrolysis of propylene and argon mixture of 5.0 - 10.0 volume percent concentration doped with 0.5 - 1. 5 volume percent of methyl trichlorosilane. Third layer of silicon carbide is deposited by pyrolysis of methyl trichlorosilane and argon mixture of 2.5 - 3.0 volume percent concentration in hydrogen-argon mixture at temperature of 1500 °C. Upon deposition this layer is treated with hydrogen at temperature of 1750 -1800 °C for 20 - 30 minutes. 90 - 95 % of fourth layer is deposited by pyrolysis of acetylene and argon mixture of 40.0 - 43.0 volume percent concentration and of argon and propylene mixture of 30.0 - 27.0 volume percent concentration at temperature of 1300 °C. Upon deposition of 90 - 95 % of fourth-layer pyrocarbon coating thickness 5 - 10 % of coating is deposited by pyrolysis of propylene and hydrogen mixture of 3.0 - 5.0 volume percent concentration.
EFFECT: enhanced service life of fuel microelements due to reduced damage probability during their manufacture and in service.
1 cl, 6 dwg, 1 tbl
SUBSTANCE: invention is designed for increasing operation parametres and life cycle of active zone of a reactor due to the maximum fuel burnup, improved reliability and operation safety of maintenance of nuclear power stations. Fuel element can of a fast reactor with liquid metal heat carrier includes a metal tube of vanadium alloy with titanium, chrome and unavoidable impurities. External and internal tube surfaces are coated with stainless ferrite steel. Vanadium alloy components are taken at a given ratio. In particular, titanium to chrome ratio lies within 2.2 to 1.8 range. Between vanadium alloy and stainless ferrite steel a 6-8 mcm thick transition layer of solid solution of vanadium alloy with stainless ferrite steel is formed.
EFFECT: improved radiation, corrosion and heat resistance and mechanical properties of fuel element can in a fast reactor with liquid metal heat carrier.
3 cl, 5 dwg
FIELD: physics, nuclear.
SUBSTANCE: invention relates to nuclear power engineering and specifically to methods of making cermet rods of fuel cores of fuel elements of nuclear reactors for different purposes. A workpiece is put into a container. Working medium in form of solid glass is put into the container and the container with the workpiece and the working medium is heated to pressing temperature. The container is put into a press mould and moulding force is applied by increasing pressure of the working medium while moving the moulding die. In the proposed method the working medium is in form of a briquette. The briquette is placed at the bottom of the container. The workpiece is put on top of the briquette. The container with the workpiece and the working medium is heated outside the press mould until the workpiece is immersed in the working medium.
EFFECT: reduced probability of formation of voids, transfer of pressure onto the moulded workpiece becomes more uniform, increased output of the suitable products.
FIELD: machine building.
SUBSTANCE: procedure consists in immersion of tubular casing of fuel rod into water electrolytic medium containing particles of iron oxide and in covering it at least partially with layer of iron oxide. Also, particles of iron oxide are produced by anode oxidising iron containing working electrode.
EFFECT: increased corrosion resistance of treated rod and its increased service life.
7 cl, 1 dwg
FIELD: physics, atomic power.
SUBSTANCE: invention relates to nuclear reactor fuel rods. Fuel rod cladding has an elliptical cross-section. Each nuclear fuel pellet along the longer axis of the cladding has a truncated elliptical shape, and the shorter axis of the pellet has the same length as the shorter axis of the cladding, minus the fitting gap j, wherein the difference in length of the longer axis of the cladding and the truncated longer axis of the pellet is much greater than said fitting gap j. The invention also relates to a method of making nuclear fuel pellets and a method of packing said pellets, which enables to form a fuel rod.
EFFECT: lower probability of deformation of fuel rod cladding and release of fission products into the coolant.
9 cl, 3 dwg
SUBSTANCE: invention relates to methods of determining compatibility of various types of nuclear fuel and structural materials. Method of testing for compatibility of nuclear fuel powder with fuel rod cladding material comprises diffusion annealing of nuclear fuel powder and fuel rod cladding pair. From material of fuel rod cladding is made crucible with a polished inner surface and lid, after which it is moulded into a powder with test fuel and fission products simulators and sealing crucible in an inert gas atmosphere, followed by annealing in temperature range of 600-1,000 °C. Testing is carried out using uranium alloy powders or uranium mononitride with particle size of 10-20 mcm. To produce crucible and cover method uses corrosion-resistant steel or zirconium alloys, and as imitators of chemically active fission products, iodine and/or caesium and/or tellurium.
EFFECT: technical result is reliable contact (adhesion) of fuel and structural materials, which increases reliability and information value of diffusion tests.
8 cl, 3 dwg
SUBSTANCE: welded assembly of fuel element comprises a jacket and a plug with collar made of high-chromium steel, connected by weld seam obtained by argon-arc welding.
EFFECT: increased reliability of sealing of the nuclear fuel elements due to obtaining of the high-quality welded joint of the jacket with plug without subsequent heat treatment of the weld seam, is achieved by forming of the ferritic phase in the weld metal by changing the design of the jacket-plug connection made of steel of ferritic-martensitic and ferritic classes in various combinations in accordance with required sizes of the assembly and weld seam elements.
4 cl, 4 dwg, 1 tbl, 4 ex