Atomic reactor core

FIELD: physics.

SUBSTANCE: device can be applied in atomic reactors in the first circuit of lead-bismuth liquid metal heat carrier. Reactor core includes fuel assemblies with pipes for installation of control and safety rod canisters, and fuel assemblies without these pipes. Baskets between upper and lower grids are wrapped in profiled shell and fixed rigidly at the lower grid. Upper grids of fuel assemblies without rod pipes are supplied with cylindrical lobes. Upper grid of the core has respective holes.

EFFECT: achievement of initial primary position of each fuel assembly with preservation of open flow areas in all standard and non-standard core cells during core operation.

2 dwg

 

The invention relates to an active zone of a nuclear reactor with a predominant use in the primary circuit liquid metal coolant lead-bismuth.

Known reactor core (Hofbrau "Nuclear ship propulsion", gosatomizdat, Moscow, 1960, pg.107), in which a fuel Assembly (FA) is circular in shape and is enclosed in a hexagonal case made of zirconium. The space between the FA and the case filled with graphite, which is a retarder. Around the active part of the zone are graphite blocks hexagonal shape, lined with zirconium, which is also a moderator. FA and blocks retarder installed in the basket surrounding the active area outside. Naturally, the peripheral row of blocks has a shape of a partial hexagon. Regulating rods are located in the Central part of the active zone in the nodes of the connections between the three neighboring blocks with FA.

Currently widely used design is the hex bassejnovoj fuel assemblies with a Central boring - pipe for the installation of the rod control system and protection system (CPS) or without it. (see: Dramanon, Mahabadi and other Marine vapour generating nuclear installation", 83, publishing house "Sudostroenie, Leningrad, 1967, Amelogenin, V.A. Kuznetsov and other Marine nuclear power plants", Tr, Atomizdat, Moscow, 1976)

Rod fuel elements (cartridges) contain within the fuel and moderator - beryllium, therefore, the active area consists of working aschehoug assemblies, which include above the fuel rods, arranged in a triangular grid with an angle of 60°forming a hexagonal shape FA. FA, located in the Central part of the active zone, have the pipes for the installation of the covers of the control rods. All fuel assemblies are placed between the upper and lower bars of the active zone. The fastening of all fuel assemblies is rigidly to the lower grille and the top bars are only TVs with pipes under the covers of the control rods. Outside FA limited curly sides of the basket of the active zone, which profile is in terms identical to the arrangement of the fuel rods of the peripheral fuel assemblies. Constructive estimated gap between the curly sides and a peripheral fuel rods up to 1.5 mm.

In the cross section of the active zone offers standard and custom cells. Standard cells are formed by the fuel rods in each fuel Assembly and are mitalee the flow area constant value. Custom cell formed peripheral fuel rods and braces the sides of the basket, and the fuel rods and a pipe passing through the fuel Assembly and which has a plastic rod cor.

Standard and non-standard cells are taken into account when deployable Eskom the calculation of the active zone. Temperature of the fuel cladding is an important condition affecting the safe operation of the active zone. The temperature of the fuel cladding above the permissible may lead to depressurization of the shell and the release of gaseous radioactive fission products fuel in the first circuit. Therefore, the provision of the necessary coolant flow through each cell is mandatory. From this point of view, the standard cells due to the constant flow area provided the desired flow and temperature of the fuel rods. In a non-standard cell flow will be different, because of the pipe section they differ from the standard cell, and, consequently, temperature adjacent to the curly side of the basket rods will be different. Thus, the temperature of the fuel rods in the core will have a radial distortion. The situation is aggravated by the fact that the peripheral fuel assemblies that are not recorded in the upper grille, under the action of hydrodynamic efforts of the coolant flow and temperature factors will be its upper part to deviate to the periphery until it stops in the profile sides of the basket, changing uncertain way the flow cross-section of abnormal cells in the upper part of the active zone with changing hydraulic and thermal modes Rets is s, what is unacceptable.

In addition, the above-described deviation of the peripheral fuel assemblies out within the existing gaps transforms standard cells on the border of the penultimate and last rows of fuel assemblies in a standard cell with increased wall sections and consumption by reducing consumption of other standard cells, which is also invalid.

Ad hoc changes during operation of the active zone of the original passage sections number of non-standard and standard cell associated eventually with a violation of the estimated temperature regime of the fuel rods, is a major drawback mentioned structure of the active zone, which is the closest technical solution and therefore adopted for the prototype.

The objective of the present invention is the preservation of the original passage sections in standard and custom cells during operation.

The technical result is providing clearing and the temperature regime of the fuel rods and improving the reliability of the active zone.

The achievement of the technical result is ensured by the fact that all of the peripheral fuel assemblies, available from pipes under the covers of the control rods are fixed to its upper part in the original mounting position in the upper grid of the active zone that does not allow them to deviate the flow of coolant, thus providing the scarfing stability of standard cells at the junction with the adjacent fuel assemblies and are provided with constant calculated flow areas peripheral abnormal cells on the border with the profile sides of the basket. This upper grille peripheral fuel assemblies provided with a cylindrical boss that you are installing FA enters the corresponding hole in the upper grid of the active zone, thereby captures FA from radial movement when working.

The invention is illustrated by drawings:

figure 1 is a longitudinal section of a fuel Assembly of the core;

figure 2 - cross section of a fuel Assembly and curly shell basket.

Figure 1 shows the peripheral fuel assemblies 1 with the fuel rods 2, the upper grid 3 FA with a cylindrical boss 4, the opening 5 of the upper grid 6 of the active zone, curly shell 7 of the basket and lower grille 8 active zone with attachment 9.

Figure 2 shows the peripheral fuel assemblies 1, the fuel rods 2, the upper lattice fuel Assembly 3, a cylindrical boss 4, figure shell 7.

In the Assembly of active zone of the fuel assemblies, each of which is set so that the sides of the hexagonal fuel assemblies in contact with the corresponding sides of adjacent hexagonal fuel assemblies, and the peripheral fuel assemblies having the form of incomplete hexagon fit is identical to the profile shape shell basket, with a cylindrical boss of each FA is included in the corresponding hole in the upper grid of the active zone, providing longitudinal thermal expansion of FA. The final fixed mount all TVs are made to the lower active grille is the first zone using the attachment.

The active area of a nuclear reactor containing the fuel assemblies with pipes for the installation of covers of rods system control and protection, and fuel assemblies, in which there are no mentioned pipe, placed in curly cowling basket between the upper and lower grilles and mounted stationary in said lower grid, characterized in that the upper lattice fuel assemblies, in which there are no pipes for the installation of covers of rods system control and protection, provided with a cylindrical base, and the upper bars of the active zone provided with corresponding holes, as a result, the Assembly of the active zone all fuel assemblies are restated in its upper part allowing longitudinal thermal expansion and prohibiting the radial movement of each fuel Assembly that provides the original initial position of each fuel Assembly with preservation of flow sections for all standard and non-standard cells of the active zone in its operation.



 

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SUBSTANCE: proposed nuclear reactor core has fuel assemblies, control and protection system cans with absorbing rods secured in supporting plate by means of collet devices; collet grip of control and protection system can is secured in supporting plate and is arranged so that fuel assembly collet-type bottom nozzle encloses lugs of can collet grip and locks them in working position.

EFFECT: enhanced safety in nuclear reactor operation.

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FIELD: pressurized-water reactor equipment.

SUBSTANCE: proposed device for securing pressurized-water reactor core with coolant flowing over it has supporting cylinder and flexible member. Supporting cylinder is mounted on pressurized tank flange. Flexible member has a number of adjacent circular segments disposed between and engageable with supporting cylinder flange and pressurized tank cover flange. Each circular segment of flexible member has segmental supporting plate. The latter mounts hold-down devices secured thereon by means of locking devices. Each hold-down device has supporting sleeve accommodating working element of precompressed thermally expanded graphite which is locked therein by means of locking device, as well as hold-down bushing. The latter is in contact with working element or with locking device.

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SUBSTANCE: proposed nuclear reactor core has fuel assemblies, control and protection system cans with absorbing rods secured in supporting plate by means of collet devices; collet grip of control and protection system can is secured in supporting plate and is arranged so that fuel assembly collet-type bottom nozzle encloses lugs of can collet grip and locks them in working position.

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Atomic reactor core // 2328042

FIELD: physics.

SUBSTANCE: device can be applied in atomic reactors in the first circuit of lead-bismuth liquid metal heat carrier. Reactor core includes fuel assemblies with pipes for installation of control and safety rod canisters, and fuel assemblies without these pipes. Baskets between upper and lower grids are wrapped in profiled shell and fixed rigidly at the lower grid. Upper grids of fuel assemblies without rod pipes are supplied with cylindrical lobes. Upper grid of the core has respective holes.

EFFECT: achievement of initial primary position of each fuel assembly with preservation of open flow areas in all standard and non-standard core cells during core operation.

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