Core structure and liquid metal cooled fast reactor

Abstract

The embodiment of the present application relates to the technical field of nuclear reactors, in particular to a core structure and a liquid metal cooled fast reactor. The core structure comprises a grid assembly, a fuel assembly, a function assembly, a stainless steel assembly and a production assembly, a plurality of channels adjacent to each other are formed in the grid assembly; the fuel assembly is arranged in the channels near the middle part; the function assembly is used for adjusting the performance of the reactor, and is arranged outside the channels where the fuel assembly is arranged; the stainless steel assembly is arranged in the outermost channels of the plurality of channels, and the remaining channels of the plurality of channels are used for arranging the production assembly to be irradiated in the core structure, so that the required substance is produced, wherein the fuel in the fuel assembly comprises nitride fuel, and the fuel assembly is arranged such that the total neutron fluence rate of the core structure is not less than a predetermined value. The core structure and the liquid metal cooled fast reactor provided by the embodiment of the present application can provide a higher neutron fluence rate, and belong to a high-flux reactor.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of nuclear reactors, and in particular, to a core structure and a liquid metal cooled fast reactor. BACKGROUND

[0002] The statements herein are merely provided to give a background of the present application and are not necessarily prior art.

[0003] For a reactor with a neutron flux close to or greater than 5×10 15 n / (cm 2 ·s), it can be called a high flux reactor. The high flux reactor plays an important role in advanced fuel research, production of special isotopes, and exploration of nuclear basic technologies. However, China currently lacks service application performance data of high flux reactors, which leads to slow progress in related research. SUMMARY

[0004] The following presents a simplified summary of the present application in order to provide a basic understanding of some aspects of the present application. This summary is not an extensive overview of the present application. It is not intended to identify key or critical elements of the present application or to delineate the scope of the present application. Its sole purpose is to present some concepts of the present application in a simplified form as a prelude to the more detailed description that is presented later.

[0005] A first aspect of embodiments of the present application provides a core structure of a reactor, which includes a grid assembly, a fuel assembly, a functional assembly, a stainless steel assembly, and a production assembly, a plurality of channels adjacent to each other are formed in the grid assembly; the fuel assembly is arranged in a channel located near the middle of the plurality of channels; the functional assembly is used to adjust the performance of the reactor and is arranged outside the channel in which the fuel assembly is arranged; the stainless steel assembly is arranged in a channel located at the outermost periphery of the plurality of channels, and the remaining channels of the plurality of channels are used to arrange the production assembly to be irradiated in the core structure, so as to produce the required substance, wherein the fuel in the fuel assembly includes nitride fuel, and the fuel assembly is arranged such that the total neutron flux of the core structure is not less than a predetermined value.

[0006] A second aspect of embodiments of the present application provides a liquid metal cooled fast reactor, which includes the core structure provided by the first aspect of embodiments of the present application.

[0007] The core structure and the liquid metal cooled fast reactor provided by embodiments of the present application can provide a higher neutron flux and belong to a high flux reactor. BRIEF DESCRIPTION OF DRAWINGS

[0008] To further clarify the above and other advantages and features of the present application, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. The drawings are not intended to be detailed to limit the application, which can be embodied in various forms. Identical reference numerals in the figures designate the same elements. It should be noted that the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the application.

[0009] Figure 1 is a structural schematic diagram of a core structure according to an embodiment of the present application;

[0010] Figure 2 is a BOC maximum neutron fluence rate distribution map of a reactor provided according to an embodiment of the present application.

[0011] It should be noted that the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the application.

[0012] BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0013] In the following, exemplary embodiments of the present application will be described with reference to the drawings. In the description, not all of the features of the actual implementation are described in order to make the description clear and brief. It should be appreciated, however, that many implementation-specific decisions can have to be made in order to develop any such actual implementation, to achieve the developer's specific goals, such as compliance with system- and business-related constraints, which can vary from one implementation to another. Moreover, it should be appreciated that depending on the

[0014] It should also be noted that, in the drawings, the illustrations of the devices and / or processes are merely schematic and the dimensions of the various features can have been exaggerated for the sake of clarity and simplicity of presentation. Additionally, it should be understood that the drawings are not necessarily drawn to scale.

[0015] The following disclosure provides various different embodiments or examples for implementing the present application. In order to simplify the present disclosure, the components and methods of the specific examples are described below. Of course, they are merely examples and the purpose is not to limit the present application. In the description of the embodiments of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0016] Referring to Figure 1 , a first aspect of embodiments of the present application provides a core structure of a reactor, which includes a grid assembly, a fuel assembly, a function assembly, a stainless steel assembly 4, and a production assembly, a plurality of channels adjacent to each other are formed in the grid assembly; the fuel assembly is disposed in a channel of the plurality of channels near the middle; the function assembly is used to adjust the performance of the reactor, which is disposed outside the channel in which the fuel assembly is disposed; the stainless steel assembly is disposed in a channel of the plurality of channels at the outermost periphery, and the remaining channels of the plurality of channels are used to dispose the production assembly to be irradiated in the core structure, so as to produce the required substance, wherein the fuel in the fuel assembly includes nitride fuel, and the fuel assembly is disposed such that the total neutron fluence rate of the core structure is not less than a predetermined value.

[0017] The predetermined value herein may, for example, be 5×10 15 n / (cm 2 ·s), and the core structure provided by the embodiments of the present application can provide a neutron fluence rate greater than 1.5×10 16 n / (cm 2 ·s), which belongs to a high-flux reactor.

[0018] Referring to Figure 1 , in the embodiments of the present application, the production assembly is disposed in Figure 1 the channel of the yellow part in the middle. The fuel assembly can use UN-PuN as the fuel pellet. The cladding outer diameter of the fuel assembly can be 4.0 mm, and the active zone length is 60 cm. The spacing between adjacent grids of the grid assembly can be 7.32 mm.

[0019] In some embodiments, the fuel assembly can include a first fuel assembly 1, a second fuel assembly 2, and a third fuel assembly 3, the enrichment of the second fuel assembly 2 is greater than the enrichment of the first fuel assembly 1, and the enrichment of the second fuel assembly 2 is equal to the enrichment of the third fuel assembly 3; the first fuel assembly 1 is disposed in the channel at the center of the plurality of channels, and the second fuel assembly 2 and the third fuel assembly 3 are disposed in the channels outside the channel of the first fuel assembly 1.

[0020] The power peak of the reactor locally limits the total power output of the entire reactor, so the reactor needs to be power flattened to improve the total output power of the reactor. Therefore, the fuel assemblies can be divided into first fuel assemblies 1, second fuel assemblies 2 and third fuel assemblies 3, and the first fuel assemblies 1 arranged in the most central channel of the plurality of channels have a relatively lower enrichment, which can play a role in power flattening. In the embodiment of the present application, the U-235 enrichment of the first fuel assemblies is 18.6%, and the U-235 enrichment of the second fuel assemblies 2 and the third fuel assemblies 3 is 30.1%, and in addition, the PuN enrichment of the first fuel assemblies 1, the second fuel assemblies 2 and the third fuel assemblies 3 is 30%.

[0021] In some embodiments, the first fuel assemblies have a plurality, and the positions of the channels in which they are arranged are sequentially arranged from the center to the outside, and the positions of the channels in which the second fuel assemblies 2 and the third fuel assemblies 3 are arranged are outside the outermost channels of the first fuel assemblies 1.

[0022] In some embodiments, the channels in which the second fuel assemblies 2 and the third fuel assemblies 3 are arranged are arranged adjacent to each other, and the channels arranged between each second fuel assembly 2 and a third fuel assembly 3 and the next second fuel assembly 2 and the next third fuel assembly 3 are used to arrange production assemblies.

[0023] The production assemblies are arranged in the channels between the second fuel assemblies 2 and the third fuel assemblies 3, and the neutron fluence is relatively high.

[0024] In some embodiments, the functional assemblies include a supplementary rod assembly SH (including SH and SH2 in Figure 1 , a safety rod assembly SA (including SA and SA2 in Figure 1 , and an absorption rod assembly PEP, and the channels in which the supplementary rod assembly SH, the safety rod assembly SA and the absorption rod assembly PEP are arranged are arranged outside the second fuel assemblies 2 and the third fuel assemblies 3.

[0025] In some embodiments, the channels in which the supplementary rod assembly SH, the safety rod assembly SA and the absorption rod assembly PEP are arranged are arranged apart from each other along the circumferential direction, and channels for arranging production assemblies are arranged therebetween.

[0026] In some embodiments, the functional assemblies further include a regulation assembly RE (including RE and RE2 in Figure 1 , and the outside of the channels in which the supplementary rod assembly SH, the safety rod assembly SA and the absorption rod assembly PEP are arranged are provided with a plurality of channels in which production assemblies are arranged and channels in which regulation assemblies RE are arranged.

[0027] In some embodiments, the outermost hole is also provided with a hole for setting a production assembly, and the hole and the hole provided with the stainless steel assembly 4 constitute the outermost hole of the core structure.

[0028] Still referring to Figure 1 , Figure 1 The yellow hole in the upper right corner can also be used to set a production assembly. The plurality of production assemblies set in the hole can form an irradiation loop. The irradiation loop can select a suitable cooling mode according to needs, such as lead-bismuth cooling, sodium cooling, air cooling, etc.

[0029] In some embodiments, the positions where the holes provided with different production assemblies are located have different maximum neutron fluxes.

[0030] Referring to Figure 2 , Figure 2 is a BOC maximum neutron flux rate distribution diagram of a reactor according to an embodiment of the present application, Figure 2 The unit of the number is 1E15cm -2 s -1 It can be seen that the core structure provided by the embodiment of the present application has a full-core maximum neutron flux rate at the center of the core, and the farther the assembly is from the center of the core, the lower the neutron flux rate. Therefore, a suitable setting position can be selected according to the irradiation dose required by the irradiation assembly. For example, Figure 1 The blue part in the figure is a hollow hole, and a production assembly can also be set in the hollow hole to receive irradiation. In the embodiment of the present application, the maximum linear power of the fuel rod is 95.2kW / m, and the flux at the periphery of the core is very high, which can provide more than 2000DPA / L of irradiation capacity per year.

[0031] The embodiment of the present application also provides a liquid metal cooled fast reactor, which comprises the core structure provided by any one of the embodiments of the present application.

[0032] For the embodiments of the present application, it also needs to be explained that the embodiments and the features in the embodiments of the present application can be combined with each other to obtain new embodiments without conflict.

[0033] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A core structure of a reactor, the reactor being a liquid metal cooled fast reactor, characterized in that, The core structure comprises: a lattice assembly in which a plurality of channels adjacent to each other are formed; a fuel assembly disposed in the channels near the middle of the plurality of channels; a functional assembly for adjusting the performance of the reactor, which is disposed outside the channels in which the fuel assembly is disposed; a stainless steel assembly disposed in the outermost channels of the plurality of channels, the remaining channels of the plurality of channels are used to dispose production assemblies to be irradiated in the core structure, thereby producing the desired substance, wherein the fuel in the fuel assembly comprises nitride fuel, and the fuel assembly is disposed such that the total neutron fluence rate of the core structure is not less than a predetermined value; the fuel assembly comprises a first fuel assembly, a second fuel assembly, and a third fuel assembly, the enrichment of the second fuel assembly is greater than the enrichment of the first fuel assembly, and the enrichment of the second fuel assembly is equal to the enrichment of the third fuel assembly; the first fuel assembly is disposed in the most central channel of the plurality of channels, and the second fuel assembly and the third fuel assembly are disposed in the channels outside the channels of the first fuel assembly; the first fuel assembly has a plurality of channels disposed therein, and the positions of the channels are sequentially arranged from the center to the outside, the positions of the channels in which the second fuel assembly and the third fuel assembly are disposed are outside the outermost channels of the first fuel assembly; the channels in which the second fuel assembly and the third fuel assembly are disposed are arranged adjacent to each other, and the channels disposed between each second fuel assembly and the next second fuel assembly and each third fuel assembly and the next third fuel assembly are used to dispose the production assemblies; wherein the U-235 enrichment of the first fuel assembly is 18.6%, the U-235 enrichment of the second fuel assembly and the third fuel assembly is 30.1%, and the mass content of PuN of the first fuel assembly, the second fuel assembly, and the third fuel assembly is 30%; wherein the predetermined value is 5 x 10 15 n / (cm 2 •s).

2. The core structure according to claim 1, wherein the functional assembly comprises a supplementary rod assembly, a safety rod assembly, and an absorption rod assembly, and the channels in which the supplementary rod assembly, the safety rod assembly, and the absorption rod assembly are disposed are disposed outside the channels in which the second fuel assembly and the third fuel assembly are disposed.

3. The core structure according to claim 2, wherein the channels in which the supplementary rod assembly, the safety rod assembly, and the absorption rod assembly are disposed are arranged at intervals along the circumferential direction, and the channels for disposing production assemblies are disposed therebetween.

4. The core structure according to claim 3, wherein the functional assembly further comprises an adjustment assembly, the outside of the channels in which the supplementary rod assembly, the safety rod assembly, and the absorption rod assembly are disposed is provided with a plurality of rings of channels in which production assemblies are disposed and channels in which adjustment assemblies are disposed.

5. The core structure according to claim 1, wherein The outermost hole is also provided with a hole for setting a production assembly, and the hole for setting the stainless steel assembly constitutes the outermost hole of the core structure.

6. The core structure according to any one of claims 1-5, characterized in that, The maximum neutron fluence obtained at the position where the different holes for setting the production assemblies are arranged is different.

7. A liquid metal cooled fast reactor, characterized in that, It comprises the core structure according to any one of claims 1-6.

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