Abstract: Actuator of a nuclear reactor control and protection system comprises: a linear step motor comprising an armature; a rod being coaxial with and connected to the armature to enable joint vertical movement and rotation about a common vertical axis, which rod can form an L-shaped bayonet connection with a working member; and a lock to prevent spontaneous rotation of the rod. The lock comprises a guiding inside the armature and provided with a flange and longitudinal through slot; a cross-member connected to the armature, mounted in the slot and capable of vertical movement therein; a fixed ring, on which the inner surface of the flange rests; and a vertical pin. Through slots are arranged equidistantly in the outside rim of the flange, the vertical pin being mounted in one of several openings arranged equidistantly about the circumference of the fixed ring to pass through one of the through slots.

Abstract: The application relates to nuclear technology for preparing fuel rods and fuel assemblies for the cores of fast-neutron reactors utilizing a liquid-metal coolant to reduce the amount of metal consumed per fuel rod. A fast-neutron reactor fuel rod having nuclear fuel disposed is in a sealed housing having a thin-walled tubular steel shell. A spacer element is wound in a coil with a large pitch on the outside surface of the shell and fastened to ends of the fuel rod on an end part of the housing. The spacer element is in the form of a metallic band twisted around its longitudinal axis, the width of the band being approximately equal to the minimum distance between adjacent fuel rods in a fuel assembly of the nuclear reactor, the cross-sectional area of the band within a range from 0.1 to 0.5 times the area of a circle described around the section.

Abstract: The invention relates to means for protecting the environment from the consequences of fires complicated by a radiation factor. A composition for dust suppression and containment of radioactive products of combustion after a fire with a radiation factor has been extinguished comprises, as a surfactant, a mixture of an anionic, a non-ionic and an amphoteric surfactant, and has the following ratio of components: 3.0-7.0% by weight of an aqueous solution of polyvinyl alcohol (in terms of a mass fraction of dry product); 0.1-0.3% by weight of plasticizer; 11.0-29.0% by weight of surfactant; with water making up the remainder. The invention makes it possible to carry out dust suppression and containment of radioactive products of combustion which are formed on surfaces, including at elevated temperatures, after a fire has been extinguished.

Abstract: The invention relates to the field of nuclear engineering and can be used to organize the natural circulation of liquid metal coolant in the heat sink of a fast neutron nuclear reactor.

Abstract: A method for searching for and detecting gamma radiation sources in conditions of nonuniform radioactive contamination is provided. Stages in which a source of maximally active radiation is determined, the radiation power is measured with a collimated detector and at the same time the distance to the source is determined with the aid of a laser detector rangefinder. Readings of the laser rangefinder and the value of a dose rate are established by the detector are recorded. The dose rate of the radiation of the actual source is calculated, after which, to verify the distance measured to the radiation source, the aiming axis of the rangefinder is moved for a distance horizontally. The measurement is repeated and the distance recorded. The results of successive measurements of the distance are compared. If there is a divergence in the measurements within the laser rangefinder error limits, the information is acknowledged as reliable.

Abstract: The invention relates to the field of thermonuclear fusion and can be used in devices for fastening a blanket module to the vacuum vessel of a fusion reactor. A device for fastening a blanket module to a fusion reactor vacuum vessel includes a support comprising flexible rod elements arranged in the form of a bundle between two flanges, in the central portion of the flanges. The support is connected by one flange to the blanket module and is mounted via the other flange in a threaded mounting seat in the vacuum vessel, wherein the support is connected to the seat by a threaded connection via a resilient clamping sleeve. The resilient clamping sleeve is mounted on the support such as to provide contact with the inner surface of the support flange facing the vacuum vessel. The diameter of the support flange facing the vacuum vessel and the diameter of the mounting seat are selected such that a radial expansion gap is formed between the flange and the mounting seat during mounting.

Abstract: The invention relates to the field of environmental protection, more specifically to the field of processing radioactive waste, and can he used for the safe and effective handling of a large quantity of liquid radioactive waste of various activity levels that has been formed as the result of decontaminating protective equipment of boxes and chambers, and makes it possible to decrease the volume of stored waste by solidifying same and incorporating same into a ceramic matrix. For this purpose, radioactive solutions after decontamination of surfaces of protective equipment are evaporated as alkaline and acidic solutions containing sodium hydroxide, potassium permanganate, oxalic acid, and nitric acid until a solid residue forms, and are calcined, and the calcinate is mixed with components of a fusion mixture containing oxides of titanium, calcium, iron (III), zirconium, and manganese (IV) and aluminum in a specified ratio, and fused.

Abstract: A method and apparatus for neutron radiography is provided for the examination of elongate radioactive items, primarily nuclear fuel elements, and also for the non-destructive testing of irradiated and non-irradiated objects in order to determine the internal structure and material composition thereof. The method and apparatus include placing an object under examination into a protective container. A detection system includes a rotatable limb with a mounting seat for securing neutron detectors in a diametric groove. The limb being mounted to be rotatable by a set angle about an axis parallel to the axis of the object under examination and having a semi-circular recess therein for the passage of an elongate object as the limb rotates by an angle ±?i relative to the direction of a neutron beam.

Abstract: A fuel assembly design for nuclear reactors that is used in fast neutron reactor cores to provide more reliable spacing of a fuel element bundle in a fuel assembly and reduced local stress in the cladding of the fuel elements in the region where the elements are in contact with spacing elements. The fuel assembly has a top nozzle and a bottom nozzle which are connected to one another by a jacket. A bundle of rod-type fuel is elements arranged in the fuel assembly with the aid of a grid and spiral spacer elements wrapped around the cladding of each fuel element. At least the peripheral fuel elements in the bundle are provided with spacer elements in the form of thin-walled tubes with longitudinal through slots, wherein the elements have a substantially oval cross section in the regions where they are in contact with the jacket.

Abstract: A thermonuclear reactor is provided having a vacuum casing and blanket modules connected thereto with flexible supports. The flexible supports are formed from a material with high electrical conductivity. Each flexible support is secured at one end on the vacuum casing and at the other end on a blanket module, the two secured ends of each flexible support face the blanket module. The flexible support is formed from two hollow cylindrical elements placed one in the other and perforated by longitudinal slots in a part free from mountings. The ends of the hollow cylindrical elements opposite the secured ends are connected electrically and mechanically. The technical result consists in diverting eddy currents away from a blanket module of a thermonuclear reactor and simultaneously eliminating electrical connectors from the composition of a blanket and reducing bunching on a blanket module side facing the vacuum casing.

Abstract: A device for electrically connecting components situated inside a nuclear fusion reactor chamber to the vacuum vessel of the reactor has two identical stacks of electrically conductive plates. The electrically conductive plates are in the shape of a symmetrical wave having at least one full period. The plates in a stack are nested one inside another and are connected to flanges for attachment to a component situated inside the chamber and to the vacuum vessel. The stacks of electrically conductive plates are mounted with mirror symmetry about a line that passes through the centers of symmetry of the flanges. The device ensures a substantially identical skin effect on all of the electrically conductive plates. In addition, the force of attraction between the outermost and center plates (the force of attraction between conductors carrying unidirectional currents) is reduced and a uniform current density distribution in each electrically conductive plate is provided.

Abstract: A device for determining the parameters of strip-type superconductors includes a generator, a generator frequency-setting element, an inductance coil connected to the generator, a receiver, a receiver frequency-setting element, and an inductance coil connected to the receiver. The generator and receiver frequency-setting elements are same type narrow-band elements. The pass bands of the generator and receiver frequency-setting elements coincide through at least half of the bandwidth of the frequency-setting element having a narrower band pass width. The generator and receiver inductance coils are arranged with a gap between the same, making it possible for a strip-type superconductor to be placed between the inductance coils. The device is provided with a temperature sensor comprising a thermistor in contact with the superconductor. The device enables highly accurate and reproducible measurement results.

Abstract: An active zone includes a homogeneous uranium-plutonium nitride fuel, the mass fraction of which is a minimum 0.305, and consists of central, intermediate and peripheral parts which form fuel assemblies comprising fuel elements with geometrically identical shells but differing heights. The radial distribution of the fuel across the volume of the active zone has a stepped shape. The radius of the central part is from 0.4 to 0.5 of the effective active zone radius, while the height of the fuel column in the fuel elements in the central part is from 0.5 to 0.8 of the height of the fuel column in the peripheral part. The heights of the fuel columns forming a stepped intermediate part for diameters ranging from 0.5 to 0.85 of the effective active zone diameter are within the range from 0.55 to 0.9 of the height of the fuel column in the peripheral part.

Abstract: Steam generators are in the form of tubular heat exchangers in which molten lead coolant flows within the pipes, while the water-steam flows in a space between the pipes, the steam generators are arranged in separate boxes and communicate with the reactor cavity by means of circulation conduits for raising and discharging the lead coolant, the steam generators and most of the circulation conduits and are arranged higher than the level of the lead coolant within the reactor cavity, and the circulation pumps are arranged within the reactor cavity on the circulation conduits and for raising the “hot” lead coolant, and a technical means is provided for ensuring natural circulation of the lead coolant through the reactor core when the circulation pumps are switched off. The specific volume of lead coolant per unit of power of the reactor is reduced and the safety of the reactor is increased.