KR101535480B1 - Plate type nuclear fuel assembly and nuclear power plant having the same - Google Patents

Abstract

The present invention provides a plate type nuclear fuel assembly which includes a plurality of nuclear fuel parts which are separately arranged with a plate type, a coating part which covers the outer side of each nuclear fuel part for protecting the nuclear fuel part, and a flow path channel part which is arranged between the nuclear fuel parts, includes a plurality of fine flow paths for a coolant flowing around the nuclear fuel part, and supports at least part of the coating part to prevent the deformation of the structure of the coating part due to a reaction between the nuclear fuel part and the coating part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a planar fuel assembly,

FIELD OF THE INVENTION The present invention relates to a plate fuel assembly composed of a plurality of plate-shaped fuel assemblies and a nuclear power plant having the same.

There are two types of nuclear fuel that are mainly used in the nuclear industry, uranium dioxide and uranium metal. Prior to commercial use, uranium dioxide was mainly formed into pellets, which were then packed into cladding to form a nuclear fuel assembly. Uranium dioxide has a high melting point and no phase transformation to the melting point, so it can be used at high output density and is being used as fuel for many commercial nuclear power plants. The fuel of uranium dioxide is processed in the form of pellets, and a plurality of pellets are stacked and inserted into the cladding of zirconium alloy or stainless steel to form fuel rods. The fuel rods are placed in a lattice of various shapes (square lattice, hexagonal lattice, And assembled into a nuclear fuel assembly.

In the research or material testing, thin film, thin plate, plate or plate type fuel using uranium metal (alloy) fuel is used in addition to nuclear fuel of commercial nuclear power plant. The metal fuel has a very good thermal conductivity, but has a low melting point and a phase change at a relatively low temperature, so that the output density can not be increased. In order to overcome this disadvantage, the metal fuel is processed into a thin film, thin plate, plate or plate shape which can greatly improve the heat transfer performance. In general, an aluminum alloy which is easy to form is used as the covering material.

However, in general, in a plate fuel, the reaction between the nuclear fuel particles and the coating material composed of aluminum increases at high temperatures, causing a swelling phenomenon, which may result in a significant deterioration of heat transfer performance and damage of the coating material .

Korean Patent Registration No. 10-1286033 (Jul. 19, 2013)

The present invention is to provide a plate fuel assembly and a nuclear power plant having the same, which can prevent the deformation of the flow path structure without deteriorating the heat transfer performance even when deformation occurs due to the fission reaction of the plate fuel.

According to an aspect of the present invention, there is provided a planar fuel assembly according to an embodiment of the present invention, comprising: a plurality of nuclear fuel assemblies spaced apart from each other in a plate form; And a plurality of micro flow paths for the coolant flowing between the fuel part and the coolant flowing around the fuel part, wherein the structure of the cover part is deformed by the reaction between the fuel part and the cover part And a channel channel portion formed to support at least a part of the cover portion to prevent the cover portion.

According to one example of the present invention, the plate-like fuel assembly includes a plurality of plate-like fuel assemblies, each of which contains the fuel particles between the nuclear fuel section and the covering section to prevent the structure of the cover section from being deformed by the fuel particles generated in the nuclear fuel section And a hollow portion formed so as to be movable.

The plate fuel assembly includes a plurality of through holes arranged in the hollow portion to maintain a gap between the fuel portion and the covering portion and increase a heat transfer amount between the fuel portion and the covering portion And may further include a grid portion.

According to another embodiment of the present invention, the flow path channel part may extend from the covering part and be integrally formed.

According to another embodiment of the present invention, each of the fuel parts may include a plurality of accommodating spaces formed by the covering parts and extending in one direction, and the accommodating space may be formed to receive the fuel.

According to another embodiment of the present invention, each of the fuel parts may include a plurality of accommodation spaces formed in a grid shape by the covering part, and the accommodation space may be formed to receive the fuel.

According to another embodiment of the present invention, the plurality of microchannels provided in the channel channel portion may be formed to extend in one direction so as to reduce the flow path resistance generated in the microchannel.

The plurality of micro flow paths may have curved portions forming curved flow paths to increase a heat transfer amount due to the flow of the coolant.

According to another embodiment of the present invention, the plurality of micro flow paths provided in the flow channel portion may be formed in such a manner that the flow path of the coolant is entirely opened so as to smooth the flow of coolant between the fuel portions.

The plurality of micro flow paths may have curved portions forming curved flow paths to increase a heat transfer amount due to the flow of the coolant.

The plurality of micro flow paths may include a plurality of streamlined portions for forming a streamlined flow path so as to reduce a flow path resistance generated in the micro flow path.

According to another aspect of the present invention, there is provided a fuel cell system including an absorber made of a material capable of absorbing neutrons and controlling the reactivity of nuclear fuel, wherein the absorber includes at least one of the nuclear fuel cell, Or may be integrally formed.

The absorber may have a cover portion formed to cover the outer periphery of the absorber for protection from the external environment.

According to another embodiment of the present invention, the control rod guide pipe further comprises a control rod guide pipe for controlling the degree of reaction of the nuclear fuel by adjusting the degree of insertion of the control rod inserted between the nuclear fuel units, And may be integrally formed with at least one of the channel portions.

According to another embodiment of the present invention, the covering portion and the channel channel portion may be integrally formed by diffusion bonding.

Further, in order to realize the above-mentioned problem, the present invention proposes a nuclear power plant having a plate fuel assembly.

The nuclear fuel assembly includes a reactor vessel and a plate-like fuel assembly composed of a nuclear fuel which is disposed to be accommodated in the reactor vessel and generates fission. The plate-like nuclear fuel assembly includes a plurality of nuclear fuel assemblies A cover portion formed to cover the outer periphery of each of the fuel portions for protecting the fuel portion, and a plurality of micro flow paths for a coolant disposed between the fuel portions and flowing around the fuel portion, And a channel channel portion formed to support at least a part of the covering portion to prevent the structure of the covering portion from being deformed by the reaction of the covering portion.

The planar fuel assemblies according to the present invention and the effects of nuclear power plants having the same will be described as follows.

According to at least one of the embodiments of the present invention, the flow path channel portion includes a micro flow path for the coolant disposed between the fuel portions and flowing around the fuel portion, and includes a deformation of the fuel portion, the cover portion, The heat transfer performance can be maintained, and the fuel part can be stably supported.

FIGS. 1A to 1G are conceptual views illustrating a planar fuel assembly according to an embodiment of the present invention.
1 (h) is a conceptual view showing an enlargement of a portion A shown in FIG.
FIGS. 2A to 2D are conceptual diagrams showing embodiments of the fuel unit shown in FIG. 1A; FIG.
FIG. 3A is a conceptual diagram illustrating embodiments in which a plurality of micro channels provided in the channel channel unit shown in FIG. 1A are closed channels. FIG.
FIG. 3B is a conceptual diagram showing embodiments in which a plurality of micro flow paths provided in the flow channel portion shown in FIG.
FIG. 4 is a conceptual diagram illustrating a planar fuel assembly according to an embodiment of the present invention and a nuclear power plant having the same. FIG.
5 is a conceptual view showing a general configuration of a nuclear fuel assembly provided in a reactor core;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a planar nuclear fuel assembly of the present invention and a nuclear power plant having the same will be described in detail with reference to the accompanying drawings.

In the present specification, the same or similar reference numerals are given to different embodiments in the same or similar configurations. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

In the present invention, the material constituting the nuclear fuel and the covering material is not limited to any particular material but may be made of any material capable of performing the functions of the nuclear fuel and the covering material. In the present invention, the plate type refers to a thin film, a thin plate, a plate or a plate.

FIGS. 1A to 1G are conceptual diagrams showing a planar fuel assembly 100 according to an embodiment of the present invention.

Referring to FIGS. 1A to 1G, the plate-shaped fuel assembly is formed of, for example, a metal fuel that is formed in a plate shape and is formed so as to suppress the deformation due to fission and to maintain the heat transfer performance. To this end, the plate fuel assembly includes a fuel portion, a covering portion and a flow channel portion.

The nuclear fuel part 110 is composed of a nuclear fuel generating chain, and has a plate shape and is spaced apart from each other at regular intervals. Here, the fuel may be made of fuel material such as uranium.

The covering portion 120 is formed to cover the outer periphery of each of the fuel parts 110 for protecting the fuel part 110. For example, the covering portion 120 may be made of a metal material, preventing the corrosion and abrasion of the fuel by the cooling material circulating the reactor, and preventing the material generated by the fissioning from contaminating the cooling material. In addition, the covering portion 120 may be formed of an aluminum alloy to facilitate molding. In addition, the covering portion 120 may be made of zirconium or an aluminum material.

The flow channel unit 130 is disposed between the fuel units 110 to maintain the fuel unit 110 structurally and stably. More specifically, the channel channel unit 130 is disposed between the nuclear fuel units 110 so that heat generated from each of the plurality of nuclear fuel units 110 can be transferred by the coolant, and flows around the nuclear fuel unit 110 And a plurality of micro flow paths F for the coolant.

Here, a swelling phenomenon may occur due to reaction of the nuclear fuel part 110 with the covering part 120. The swelling phenomenon means a phenomenon in which the volume increases due to a substance generated by fission. At this time, in order to prevent the structure of the covering part 120 from being deformed by reacting the nuclear fuel part 110 and the covering part 120 with each other, at least a part of the covering part 120 .

According to the structure of the present invention described above, the covering portion 120 and the flow path channel portion 130, which accommodate the fuel portion 110 in the form of a plate, are integrally joined to each other through diffusion bonding or the like, The flow channel unit 130 that stably supports each of the fuel units 110 between the nuclear fuel units 110 even when the fuel cell unit 110 reacts with the cover unit 120 to cause deformation of the fuel cell unit 110 The deformation of the nuclear fuel part 110, the covering part 120 and the microchannel can be suppressed and the heat transfer in the microchannel can be smoothly performed. In addition, deformation of the flow channel part 130 is prevented, the coolant flow smoothly, and the arrangement of the fuel part 110 and the covering part 120 can be stably maintained. As a result, there is an advantage that the nuclear fuel assembly 100 having the stabilized performance and structural stiffness can be implemented, contributing to the safety improvement of the nuclear power plant.

Meanwhile, the channel channel portion 130 may extend from the covering portion 120 and be integrally formed, as shown in FIG. 1H, (c). At this time, the covering portion 120 and the channel channel portion 130 may be made of the same material or different materials. For this purpose, the covering section 120 and the channel channel section 130 are processed simultaneously and the nuclear fuel section 110 is disposed between the different covering sections 120, And the cover 130 and the covering portion 120 are coupled to each other.

The flow channel unit 130 is formed by separately processing the fuel unit 110 and the covering unit 120 and the flow channel unit 130 integrally formed as shown in FIGS. 1 (a) and 1 (b) And the step of joining the covering section 120 and the channel channel section 130 by welding or diffusion bonding. The flow channel unit 130 may be formed to have a plurality of fine flow paths F between the fuel unit 110 and the covering unit 120 integrally formed as shown in FIG. And may be formed so as to have a micro flow path F in one row between the fuel part 110 and the covering parts 120 integrally formed as shown in FIG. 1A.

The plate fuel assembly 100 may further include an absorber 140.

The absorber 140 is made of a material that absorbs neutrons and is made to compensate for the change in response due to the change in concentration due to the operation of the nuclear fuel. Specifically, the absorber 140 may be integrally formed with at least one of the nuclear fuel part 110, the covering part 120, and the channel channel part 130 in various forms as shown in FIGS. 1A to 1G . The absorber 140 is an absorbing rod installed in a general nuclear fuel assembly. The absorber 140 is installed to reduce the difference in core reactivity between the driving cycle of the core and the end of the driving cycle, and absorbs neutrons to suppress the reactivity. For example, the absorber 140 suppresses the reactivity of the absorber 140 because the uranium concentration of the fuel is high at the beginning of the operation period of the nuclear reactor, and the neutron absorber of the absorber 140 is used at the end of the operation period. The deterrent is reduced.

In addition, the absorber 140 may have a cover portion (not shown) formed to cover the outer periphery of the absorber 140 to prevent the absorber 140 from being damaged from the external environment.

The plate-like nuclear fuel assembly 100 may further include a control rod guide pipe 150.

The control rod guide pipe 150 is configured to control the degree of reaction of the nuclear fuel by adjusting the degree of insertion of the control rod inserted between the nuclear fuel parts. Here, the control rod guide pipe 150 may be formed in a plate shape as shown in FIGS. 1A to 1G, and may be integrally formed with at least one of the covering portion 120 and the channel channel portion 130. Here, the control rod is generally made of a material that absorbs thermal neutrons well.

The plate-like fuel assembly 100 may further include a measuring unit 160.

The measuring unit 160 is installed to measure the temperature or the reaction degree of the reactor core. Here, the measuring unit 160 may be disposed at the center of the plate fuel assembly 100 as shown in FIGS. 1A to 1G. At this time, the measuring unit 160 is not necessarily limited to the illustrated position, and may be disposed at a position other than the central portion of the plate-shaped fuel assembly 100 according to the characteristics of the nuclear power plant.

Hereinafter, the fuel unit 110 of the plate-like fuel assembly 100 will be described with reference to FIGS. 2A to 2D.

FIGS. 2A to 2D are conceptual diagrams showing embodiments of the fuel unit 110 shown in FIG. 1A.

First, as shown in FIGS. 2A and 2B, one surface of the fuel part 110 and the covering part 120 may be formed to face each other in the plate-shaped fuel assembly 100. FIG. 2A and 2B, each of the nuclear fuel units 110 includes a plurality of accommodating spaces S formed by a covering portion 120 extending in one direction, And the fuel space for generating nuclear fission may be accommodated in the accommodation space S. In addition, as shown in FIG. 2A, each of the fuel units 110 may be formed as a unit space S in which the nuclear fuel is contained, without being partitioned by the covering unit 120.

2B, a plurality of accommodating spaces are formed in a lattice shape by the covering portion 120, and each of the fuel portions 110 is formed in a receiving space (not shown) formed in the lattice shape S may be formed to accommodate the nuclear fuel generating fission.

Meanwhile, as shown in FIGS. 2C and 2D, the plate fuel assembly may further include a hollow portion H.

The hollow portion H is formed in the fuel portion 110 so as to prevent the nuclear fuel particles (not shown) generated due to the fission reaction in the fuel portion of the nuclear fuel portion 110 from increasing to deform the structure of the covering portion 120 And the covering portion 120. The fuel particles can be received by the cover portion 120 and the cover portion 120, respectively. Accordingly, even when the amount of the fuel particles generated by the reaction of the fuel increases, the structure of the covered portion can be stably maintained by the hollow portion H that receives the fuel particles.

For example, the plate-like fuel assembly 110 may further include a grid portion 170 to form the hollow portion H.

The grid portion 170 is disposed on the hollow portion H to maintain a gap between the nuclear fuel portion 110 and the covering portion 120 and is provided with a nuclear fuel portion 110 and a covering portion 120, A plurality of through holes 173 may be provided as shown in FIGS. 2C and 2D to increase the heat transfer amount between the through holes 173. Here, the grid portion 170 may be disposed between the fuel portion 110 and the covering portion 120 having a single fuel accommodation space, as shown in FIG. 2C (a). As shown in FIGS. 2 (b) and 2 (d), a nuclear fuel unit 110 having a plurality of nuclear fuel receiving spaces S formed by a covering portion 120 extending in one direction And the covering portion 120. [0050] 2 (b), there is a gap between the nuclear fuel part 110 having a plurality of nuclear fuel receiving spaces S formed in a lattice shape by the covering part 120 and the covering part 120 . Meanwhile, the grid portion 170 and the covering portion 120 can be integrally formed.

The structure of the grid unit 170 selectively adopts various types of gaps and a structure for forming the gaps between the fuel unit 110 and the covering unit 120 to facilitate the application of the diffusion bonding technology And the heat transfer performance between the nuclear fuel part 110 and the covering part 120 is achieved at a designed level or higher while the swollen part of the nuclear fuel part 110 is accommodated by receiving the nuclear fuel particles generated in the nuclear fuel part 110, So that the structure of the plate-shaped fuel assembly 100 can be more stably maintained.

Hereinafter, the flow channel portion 130 of the plate-like fuel assembly 100 will be described with reference to FIGS. 3A and 3B.

FIG. 3A is a conceptual view illustrating embodiments in which a plurality of microfluidic channels F provided in the channel channel unit 130 shown in FIG. 1A are closed channels. FIG. 3B is a cross-sectional view of the channel channel unit 130 And a plurality of microfluidetic channels F provided in the open channel.

3A, a plurality of microfluidic channels F provided in the channel channel unit 130 are formed in order to reduce the flow channel resistance caused by the flow of the coolant in the microfluidic channel F And may extend in one direction.

3A, the plurality of micro-flow paths F provided in the flow channel unit 130 are formed in a curved line shape that forms a curved flow path so as to increase the heat transfer amount due to the flow of the coolant, (131) to change the flow shape and increase the heat transfer area so that heat exchange in the micro flow path (F) can occur well.

3B, a plurality of microfluidic channels F provided in the channel channel unit 130 are formed so that the flow path of the coolant is opened as a whole so as to smoothly flow the coolant between the fuel units 110. [ .

3B, the micro flow path F is formed in a curved shape so as to increase the amount of heat transfer by changing the flow shape and increasing the heat transfer area so that heat exchange is likely to occur in the flow of the coolant. And a curved portion 133 that forms a flow path of the fluid.

As shown in FIG. 3B, the microfluidic channel F includes a plurality of microfluidic channels F for forming a streamlined channel so as to reduce the resistance of the microfluidic channels F, (135). Accordingly, there is an advantage that the heat transfer amount of the coolant can be increased and the resistance of the flow path generated in the micro flow path F can be reduced.

Hereinafter, a planar fuel assembly 100 according to an embodiment of the present invention and a nuclear power plant 10 having the same will be described with reference to FIGS. 4 and 5. FIG.

FIG. 4 is a conceptual diagram showing a planar fuel assembly according to an embodiment of the present invention and a nuclear power plant having the same. FIG. 5 is a conceptual diagram illustrating a general configuration of a nuclear fuel assembly 100 provided in a reactor core 100.

Referring to FIGS. 4 and 5, the reactor, that is, the reactor coolant system, is a system that transports heat energy generated by the nuclear fission of nuclear fuel in the core. The core 100 is installed inside the reactor.

The reactor vessel 100a is a main structure surrounding the core 100. The reactor vessel 100a may include a core 100 of the reactor and a steel container having a finish coated with a stainless steel coating member for receiving the reflector.

Hereinafter, the operation of the nuclear power plant 10 including the planar fuel assembly 100 of the present invention will be described with reference to FIG. In the following description, the planar fuel assembly 100 and the core 100 are used in a similar meaning.

First, a fluid, that is, a coolant, is supplied from a lower portion of the core 100 to a lower portion (inlet) of the plate fuel assembly 100. At this time, the coolant supplied to the lower portion of the plate-shaped fuel assembly 100 rises along the flow path of the flow path channel portion 130 and the temperature increases. The coolant heated while rising along the flow path is discharged to the top (outlet) of the plate fuel assembly 100.

The coolant discharged to the outlet of the core 100 through the upper part of the plate-like fuel assembly 100 is supplied to the primary side flow path of the steam generator 12 to be cooled. At this time, And is supplied to the lower portion of the nuclear fuel assembly 100. Here, in the pressurized light water reactor, the reactor coolant system is pressurized to keep the coolant in a single phase (water), and in the forced circulation reactor (commercial nuclear power plant), the reactor coolant pump 14 circulates the coolant.

At this time, water is supplied to the secondary side of the steam generator 12 through the water supply system W, and steam of high temperature and high pressure is produced by using the heat transferred from the reactor coolant system. The generated steam is supplied to the turbine system T, So as to produce electricity.

5 shows a general configuration of a nuclear fuel assembly 20 provided in a nuclear reactor core 100. The nuclear fuel assembly 20 includes a planar fuel portion 110 (described in the embodiments of the present invention) A fuel rod 22, an absorbing rod 24, a control rod guide pipe 26, and a measuring pipe 28, which perform the same functions as the absorber 140, the control rod guide pipe 150 and the measurement unit 160, Respectively. Here, the fuel rod 22 means that the uranium oxide or plutonium oxide powder used for the reactor is formed into a cylindrical shape and is baked at a high temperature to seal the fuel pellet with a helium gas to a cladding tube (not shown).

However, the scope of the present invention is not limited to the configuration and method of the embodiments described above, and all or some of the embodiments may be selectively combined so that various modifications may be made to the embodiments. In addition, the present invention can be applied to all equivalents of inventions, such as inventions that can be modified, added, deleted, or replaced at the level of those skilled in the art, It belongs to the scope is self-evident.

100: plate-shaped fuel assembly 110: nuclear fuel assembly
120: covering portion 130: flow channel portion
140: absorber 150: control rod guide tube
160: Measuring section 170: Grid section

Claims (16)

A plurality of fuel parts spaced apart from each other in a plate form;
A covering part formed to cover an outer periphery of each of the fuel parts for protecting the fuel part; And
And a plurality of micro flow paths for the coolant flowing around the nuclear fuel part and disposed between the plurality of facing nuclear fuel parts to prevent the structure of the cover part from being deformed by the reaction between the nuclear fuel part and the cover part And a flow path channel part dispersed to a plurality of points of support formed corresponding to the plurality of micro flow paths to support the cover part. The method according to claim 1,
Further comprising a hollow portion formed between the nuclear fuel portion and the covering portion so as to be able to receive the fuel particles in order to prevent the structure of the cover portion from being deformed by the nuclear fuel particles generated in the nuclear fuel portion, Nuclear fuel assembly. 3. The method of claim 2,
And a grid portion disposed in the hollow portion and having a plurality of through holes to maintain a gap between the nuclear fuel portion and the covering portion and increase a heat transfer amount between the nuclear fuel portion and the covering portion Of the fuel assembly. The method according to claim 1,
Wherein the flow channel portion extends from the covering portion and is integrally formed. The method according to claim 1,
Wherein each of the fuel parts has a plurality of accommodating spaces formed by the covering parts and extending in one direction, and the accommodating space is formed to accommodate the nuclear fuel. The method according to claim 1,
Wherein each of the nuclear fuel compartments has a plurality of accommodating spaces formed in a lattice shape by the covering portion, and the accommodating space is formed to accommodate the nuclear fuel. The method according to claim 1,
Wherein the plurality of micro flow paths provided in the flow channel portion are formed to extend in one direction so as to reduce the flow path resistance generated in the micro flow path. 8. The method of claim 7,
Wherein the plurality of micro flow paths are provided with curved portions forming curved flow paths so as to increase a heat transfer amount due to the flow of the coolant. The method according to claim 1,
Wherein the plurality of micro flow paths provided in the flow path channel portion are formed in such a manner that the flow path of the coolant is entirely opened so as to smooth the flow of the coolant between the fuel portions. 10. The method of claim 9,
Wherein the plurality of micro flow paths are provided with curved portions forming curved flow paths so as to increase a heat transfer amount due to the flow of the coolant. 11. The method of claim 10,
Wherein the plurality of micro flow paths are provided with a plurality of streamlined portions for forming streamlined flow paths so as to reduce the flow path resistance generated in the micro flow paths. The method according to claim 1,
Further comprising an absorber made of a material capable of absorbing neutrons and controlling the reactivity of the nuclear fuel,
Wherein the absorber is formed integrally with at least one of the fuel part, the covering part, and the channel channel part. 13. The method of claim 12,
Wherein the absorber has a cover portion formed to cover an outer periphery of the absorber for protection from an external environment. The method according to claim 1,
And a control rod guide pipe for controlling the degree of reaction of the nuclear fuel by adjusting the insertion degree of the control rod inserted between the nuclear fuel units,
Wherein the control rod guide tube is formed integrally with at least one of the covering portion and the channel channel portion. The method according to claim 1,
Wherein the covering portion and the channel channel portion are integrally formed by diffusion bonding. Reactor vessel; And
A nuclear fuel assembly disposed within the reactor vessel to generate nuclear fission;
The plate fuel assembly,
A plurality of fuel parts spaced apart from each other in a plate form;
A covering part formed to cover an outer periphery of each of the fuel parts for protecting the fuel part; And
And a plurality of micro flow paths for the coolant flowing around the nuclear fuel part and disposed between the plurality of facing nuclear fuel parts to prevent the structure of the cover part from being deformed by the reaction between the nuclear fuel part and the cover part And a flow channel part dispersed to a plurality of points of support formed corresponding to the plurality of micro flow paths to support the cover part.

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