Conduit

 

The invention relates to devices of nuclear energy, in particular to the structural elements of fuel assemblies from power reactors VVER-1000. Conduit consists of a tube and tip. The pipe is made from a material with a low coefficient of growth. On the tube in increments of step placement grid spacers, at least by their upper end is installed restrictive bushing. The technical result - improving the reliability of fuel assemblies. 1 Il.

The invention relates to devices of nuclear energy, in particular to the structural elements of fuel assemblies from power reactors VVER-1000.

Known guide channels (see U.S. patent No. 4687619, MKI G 21 19/20, 1987, evidence of the Russian Federation No. 6937, MKI G 21 3/04, 1995, testimony of the Russian Federation No. 8514, MKI G 21 3/04, 1998), consisting of the pipe, the gripping sleeve and tip.

A disadvantage of the known solutions is the lack of devices preventing displacement and deformation during operation under the action of loads, the spacer grids of the fuel Assembly.

The closest in technical essence and the achieved achiev the pipe, the gripping sleeve, the tip, the lack of which is the lack of devices preventing displacement and deformation during operation under the action of loads, the spacer grids of the fuel Assembly.

An object of the invention is to improve the operational reliability of the fuel assemblies.

The problem is solved in that in the guide channel, consisting of a tube and tip according to the invention, the pipe made of a material with a low coefficient of radiation-induced growth increments step placement grid spacers, at least from their upper set of restrictive sleeve.

This set of features is new and involves an inventive step because the execution pipe channel from a material with a low coefficient of radiation growth, eliminate unacceptable lengthening during operation and improves the reliability of fuel assemblies, due to the reduction of their bending, in addition, eliminates the offset grid spacers under the action of loads during operation of the fuel assemblies.

The drawing shows the guide channel. The guide channel socioeconomica 2, used to connect the guide channel with the lower part of the fuel Assembly, the pipe 1 is placed in a restrictive bushing 3, the number of which is at least equal to the number of grid spacers. Mount bushing 3 to the pipe 1 is carried out, for example pin-point welding. On the sleeve 3 to simplify its Assembly and welding of the guiding channel in the zone of weld seams can be performed longitudinal section 4.

Conduit is an integral part of the fuel Assembly and is intended for the perception of the mechanical loads acting on the Assembly in the course of its operation, place the rod control system and protection. Increasing the length of the guide channel under the action of radiation exposure leads to its curvature. In the worse conditions of safe operation of fuel assemblies.

The presence of restrictive bushing 3 eliminates the displacement and deformation of the grid spacers under the action of loads encountered during operation of fuel assemblies, which increases the operational reliability of the fuel assemblies. To reduce the specific pressure in the contact zone of restrictive sleeves with distantsionno the resistance to the flow of fluid, restrictive sleeve in the zone of contact with the spacer bars may have a thickness greater than the area of the weld seams. Specific parameter values restrictive bushings are determined experimentally depending on the design characteristics of the channel (material, diameter, wall thickness), grid spacers, and the minimum hydraulic resistance of the fluid.

Claims

Conduit containing tube to the handpiece, wherein the pipe is made from a material with a low coefficient of radiation-induced growth increments step placement grid spacers, at least by their upper end is installed restrictive bushing.

 

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