Matrix, control rod, reactor control assembly and reactor control system

Abstract

The invention relates to a substrate, a control rod, and a reactor control assembly and system. The base body (120) is matched with an absorption core (110) and a cladding (130) of the control rod (10), a core groove (121) is formed in the base body (110), the core groove (121) is used for containing the absorption core (110), and in the using process, the absorption core (110) is located in the core groove (121), and the base body (120) is located in the cladding (130).

Description

Matrix, control rods, reactor control components and systems Technical Field

[0001] The present application relates to the field of nuclear energy, and in particular to a substrate, a control rod, a reactor control assembly and a system. Background Art

[0002] At present, the active area of ​​the reactor control assembly is mainly designed in the form of a control rod bundle, in which the control rod is mainly a "cladding-core block" structure, and the absorption core is located in the cladding. On the cross section of the control rod, from the inside to the outside are the absorption core and the cladding, and the cladding and the absorption core are directly separated. The cladding is generally a thin stainless steel round tube structure.

[0003] Taking boron carbide as an absorber core material, for example, during irradiation, boron carbide swells and can fragment due to factors such as thermal stress and helium retention. This swelling and fragmentation can affect the life of control rods and, in turn, the life of reactor control assemblies. The primary mechanism is the interaction (ACMI) between the absorber core or its fragments and the cladding material, which can cause cladding damage and compromise control rod integrity. Furthermore, the redistribution of small absorber core fragments within the control rod can lead to geometric changes such as reduced absorber length and increased diameter, affecting the axial alignment and reactivity distribution of the control rods, and thus compromising absorber element function. Furthermore, free carbon generated by boron carbide irradiation can penetrate the stainless steel cladding, causing embrittlement of the cladding material and threatening control rod integrity.

[0004] Therefore, the control rods in the current reactor control assembly have a problem of short lifespan.

[0005] Summary of the Invention

[0006] Based on this, an embodiment of the present application provides a control rod substrate.

[0007] A control rod base is provided, which is adapted to the absorbent core and cladding of the control rod. A core groove is provided on the base for accommodating the absorbent core. When in use, the absorbent core is located in the core groove and the base is located in the cladding.

[0008] In one embodiment, the material of the substrate includes solid metal.

[0009] In one embodiment, the material of the matrix includes one or more of a neutron absorbing material and a moderating material.

[0010] In one embodiment, the moderator material includes one or more of zirconium hydride, yttrium hydride, graphite, beryllium and beryllium oxide.

[0011] In one embodiment, a cooling channel is further provided on the base, and the cooling channel is used to cool the absorbent core.

[0012] In one embodiment, the base is cylindrical, and the cooling channel is located in the axial direction of the base.

[0013] In one embodiment, an air vent is provided on the base, and the air vent is communicated with the core groove.

[0014] In one embodiment, the base includes a top and a main body, the core groove is a groove opened on the main body and open at one end, the opening of the groove faces the main body, and the air duct is located on the top.

[0015] In one embodiment, the base body is provided with a plurality of core grooves, the plurality of core grooves are arranged at intervals, and the absorbent core is located in each of the core grooves.

[0016] In one embodiment, the base body is provided with a plurality of cooling channels, and the plurality of cooling channels are arranged at intervals.

[0017] In one embodiment, the absorbent core is in a rod shape, and the peripheral surface of the absorbent core is in direct contact with the core groove.

[0018] In one embodiment, the base further includes a connecting portion, and the connecting portion is used to be fixedly connected to the cladding.

[0019] In addition, an embodiment of the present application further provides a control rod, including:

[0020] absorbent core;

[0021] The substrate of any of the above embodiments, wherein the absorbent core is located in the core groove of the substrate; and

[0022] The substrate is located in the shell.

[0023] In one embodiment, the control rod includes a plurality of absorbent cores, the base is provided with a plurality of core grooves, and each of the core grooves contains one absorbent core.

[0024] In one embodiment, the control rod further comprises a support member, wherein the support member is located in the core groove, and the support member is used to support the absorbent core and provide axial positioning for the absorbent core.

[0025] In addition, an embodiment of the present application further provides a reactor control assembly, including:

[0026] brackets; and

[0027] The control rod in any of the above embodiments is fixed on the bracket.

[0028] In addition, an embodiment of the present application further provides a reactor control system, comprising the reactor control assembly and a driving member according to any of the above embodiments, wherein the driving member is used to drive the reactor control assembly.

[0029] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below, and other features, objects, and advantages of the present application will be apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without any creative work.

[0031] FIG1 is a control rod according to an embodiment;

[0032] FIG2 is an exploded view of the control rod shown in FIG1 ;

[0033] FIG3 is a cross-sectional view of the control rod shown in FIG1;

[0034] FIG4 is a cross-sectional view of the control rod shown in FIG1 taken from another angle.

[0035] Reference numerals:

[0036] 10. Control rod; 110. Absorbent core; 120. Base; 121. Core groove; 122. Air duct; 123. Connecting part; 130. Enclosure; 131. Bottom shell; 132. Middle section; 133. Top shell; 140. Fixing part. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] It should be noted that when an element is described as being "fixed to" another element, it may be directly on the other element, or one or more centered elements may be present therebetween. When an element is described as being "connected to" another element, it may be directly connected to the other element, or one or more centered elements may be present therebetween. The terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating positions or positional relationships based on those shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two elements, or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0040] It should be noted that, in this article, unless otherwise specified, "fixed connection" is an abbreviation of "fixed connection", and the method of fixed connection is not particularly limited. It can also be a detachable fixed connection, such as screw connection, clip connection, etc., or a non-detachable fixed connection, such as bonding, welding, and riveting. In addition, when two elements are described as being in a connection relationship, they can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of the two elements or the interaction relationship between the two elements. The term "approximately" used in this article refers to ±10% of the value; further, "approximately" refers to ±5% of the value; and further, "approximately" refers to ±3% of the value.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0042] An embodiment of the present application provides a reactor control assembly that can be used in a fast neutron reactor. The reactor control assembly includes a bracket and a control rod 10 . The control rod 10 is fixed to the bracket.

[0043] 1 to 3 , the control rod 10 includes an absorbent core 110 , a base 120 and a shell 130 . The base 120 is provided with a core groove 121 . The absorbent core 110 is located in the core groove 121 , and the base 120 is located in the shell 130 .

[0044] The absorption core 110 serves as a component that mainly absorbs fast neutrons. In some embodiments, the material of the absorption core 110 includes one or more of boron carbide, hafnium (Hf), silver indium cadmium (Ag-In-Cd) and dysprosium titanate. In an optional specific example, the material of the absorption core 110 is boron carbide, hafnium, silver indium cadmium or dysprosium titanate. It is understood that in other embodiments, the material of the absorption core 110 is not limited to the above, and can also be other materials. In addition, it is understood that there is no special restriction on the shape of the absorption core 110, and it can be adapted to the core groove 121. In an optional specific example, the absorption core 110 is rod-shaped or block-shaped.

[0045] In some embodiments, the circumference of the absorbent core 110 is in direct contact with the core groove 121. In other embodiments, there is a gap between the circumference of the absorbent core 110 and the core groove 121. In some embodiments, the absorbent core 110 does not completely fill the core groove 121, that is, there is residual space between the absorbent core 110 and the core groove 121. This arrangement allows room for the absorbent core 110 to expand after irradiation.

[0046] In some embodiments, the absorbent core 110 is rod-shaped, with a diameter of about 3 mm to 15 mm and a length of about 100 mm to 900 mm. It is understood that the diameter and length of the absorbent core 110 are not limited thereto and can be adjusted according to specific needs.

[0047] Referring to Figures 3 and 4, in some embodiments, the control rod 10 includes multiple absorbent cores 110. When there are multiple absorbent cores 110, the number of core slots 121 can be equal to or less than the number of absorbent cores 110 (for example, there are multiple absorbent cores 110 and one core slot 121). In an alternative specific example, there are multiple absorbent cores 110, and the number of core slots 121 is equal to the number of absorbent cores 110, i.e., there are also multiple absorbent cores 110, with each core slot 121 containing an absorbent core 110. In the illustrated embodiment, the absorbent cores 110 are round rods, with seven absorbent cores 110. It is understood that in other embodiments, the number of absorbent cores 110 is not limited to this and can be other numbers, for example, one, two, three, five, eight, or ten. It is also understood that in other embodiments, the shape of the absorbent cores 110 is not limited to a rod and can be other shapes. In the illustrated embodiment, the cross-section of the absorbent cores 110 is circular. It is understood that in other embodiments, the cross-sectional shape of the absorbent core 110 is not limited thereto, and may be other shapes, such as square, oval, etc. Compared with a control rod 10 having a single absorbent core 110, a control rod 10 having multiple absorbent cores 110 has a simpler manufacturing process and better performance.

[0048] Referring to Figure 4 , in the illustrated embodiment, one absorbent core 110 is located at the center of the base 120, and the remaining six absorbent cores 110 are arranged at equal intervals around the centrally located absorbent core 110. It is understood that in other embodiments, the arrangement of the absorbent cores 110 is not limited to the above, and other arrangements are possible, such as a square matrix arrangement. Of course, the core slots 121 must be provided accordingly.

[0049] The matrix 120 is located between the absorbent core 110 and the cladding 130. By arranging the matrix 120 between the absorbent core 110 and the cladding 130, the radial gap between the cladding 130 and the absorbent core 110 is partially or completely filled by the matrix 120, thereby reducing the risk of rupture of the cladding 130 caused by the interaction between the absorbent core 110 and the cladding 130, and improving the integrity of the absorbent body section of the absorbent core 110 in a fast neutron environment. This can better contain the swelling and fragments generated by the breakage of the absorbent core 110 during operation, thereby extending the life of the control rods 10 and thereby improving the life of the reactor control assembly.

[0050] In some embodiments, the material of the substrate 120 comprises solid metal. In one embodiment, the material of the substrate 120 is solid metal. In an alternative specific example, the material of the substrate 120 comprises stainless steel. The solid metal material of the substrate 120 can provide the substrate 120 with greater strength. Solid metal has excellent heat transfer efficiency, enabling rapid radial heat conduction, thereby minimizing thermal stress on the absorbent core 110. This makes the substrate 120 more resistant to debris generated by expansion and breakage of the absorbent core 110, thereby increasing the lifespan of the control rod 10.

[0051] In some embodiments, the material of the matrix 120 includes one or more of a neutron absorbing material and a moderator material. The inclusion of the neutron absorbing material and the moderator material in the matrix 120 enables the matrix 120 to absorb fast neutrons, further improving the absorption efficiency of the control rod 10. In one embodiment, the neutron absorbing material includes one or more of boron, boron carbide, cadmium, and silver indium cadmium. In an alternative specific example, the neutron absorbing material is boron, boron carbide, cadmium, or silver indium cadmium. In one embodiment, the moderator material includes one or more of zirconium hydride (ZrH2), yttrium hydride (YH2), graphite (C), beryllium (Be), and beryllium oxide (BeO). In an alternative specific example, the moderator material is zirconium hydride, yttrium hydride, graphite, beryllium, or beryllium oxide. It will be appreciated that the neutron absorbing material and the moderator material are not limited to the above and may also be other substances.

[0052] In some embodiments, the base 120 is generally cylindrical with a plurality of spaced grooves (core grooves 121). In the illustrated embodiment, the base 120 is generally honeycomb-shaped. It is understood that in other embodiments, the shape of the base 120 is not limited to the above and may also be other structures with grooves (core grooves 121), such as a quadrangular prism with through holes and blind holes.

[0053] In some embodiments, the base 120 includes a top portion and a main body portion. The core groove 121 is a groove formed on the main body portion and open at one end, with the groove opening facing the top portion. It is understood that the top portion and the main body portion are detachably fixedly connected (e.g., screwed, snap-fitted, etc.). During assembly, the absorbent core 110 is placed in the core groove 121 of the main body portion, and the top portion and the main body portion are fixedly connected to form the control rod 10.

[0054] In some embodiments, the base 120 is cylindrical, with a diameter of about 35 mm to 50 mm and a length of about 200 mm to 1000 mm. It is understood that the diameter and length of the base 120 are not limited thereto and can be adjusted according to specific needs.

[0055] Furthermore, a cooling channel (not shown) is provided on the base 120, and the cooling channel is used to cool the absorbent core 110. The cooling channel is used for the circulation of coolant. When in use, the coolant flows from the end of the main body away from the top to the top through the cooling channel. It is understandable that the type of coolant is not limited and can be a coolant commonly used in the art. In some embodiments, the base 120 is columnar, and the cooling channel is located in the axial direction of the base 120. In one embodiment, the cooling channel is spirally arranged along the axial direction of the base 120. In another embodiment, the cooling channel is parallel to the axial direction of the base 120. In some embodiments, the cooling channel is connected to the core groove 121. In other embodiments, the cooling channel is not connected to the core groove 121. In some embodiments, there are multiple cooling channels, and the multiple cooling channels are spaced apart. In other embodiments, there are multiple cooling channels, some of which are connected to the core groove 121, and some of which are spaced apart from the core groove 121.

[0056] Please refer to Figure 4. In some embodiments, the cooling channels are arranged around the center of the substrate 120 for two cycles. The spacing between the cooling channels in the cycle close to the center of the substrate 120 is equal, and the spacing between the cooling channels in the cycle farther from the center of the substrate 120 is also equal.

[0057] Furthermore, an air duct 122 is provided on the base 120, and the air duct 122 is connected to the core groove 121. By providing the air duct 122, the gas generated by the absorbent core 110 due to irradiation can be discharged in time, reducing the effect of the gas generated after the absorbent core 110 is irradiated on the base 120, and reducing the effect of the gas generated after the absorbent core 110 is irradiated on the shell 130. In some embodiments, the air duct 122 is provided on the top. In the illustrated embodiment, the air duct 122 is located on the axis of the protrusion at the top and passes through the protrusion. Of course, the air duct 122 can also be provided at other positions on the top, so as to release the gas generated by the absorbent core 110 in the core groove 121. It is understandable that the air duct 122 can also be connected to the cooling channel. For example, the liquid outlet end of the cooling channel is connected to the core groove 121, and the core groove 121 is connected to the air duct. At this time, the coolant flowing in from the cooling flow channel may flow from the cooling flow channel into the core groove 121 , then flow into the air passage 122 through the flow groove, and then flow out from the air passage 122 .

[0058] In some embodiments, the base 120 further includes a connecting portion 123, which is located at an end of the main body away from the top and is used to be fixedly connected to the enclosure 130. In the illustrated embodiment, the connecting portion 123 is a protruding structure located at an end of the main body away from the top.

[0059] The cladding 130 is used to house the base 120. It will be understood that the cladding 130 is adapted to the base 120 so that the absorbent core 110, base 120, and cladding 130 can be assembled to form the control rod 10. In the illustrated embodiment, it comprises a bottom shell 131, a middle section 132, and a top shell 133. The top shell 133 is located near the top, while the bottom shell 131 is located near the connection portion 123. There is also a gap between the top shell 133 and the base 120. If a cooling channel is provided in the base 120, a through hole is provided in the top shell 133 to communicate with the cooling channel, and a channel for the flow of coolant is provided in the bottom shell 131. If an air duct 122 is provided in the base 120, a through hole is provided in the bottom shell 131 to communicate with the air duct 122. In some embodiments, the top shell 133 and the middle section 132 are integrally formed.

[0060] In some embodiments, the material of the cladding 130 includes zirconium alloy and stainless steel. In one embodiment, the material of the cladding 130 is stainless steel.

[0061] In some embodiments, the control rod 10 further includes a support member (not shown), which is located in the core groove 121 and is used to support the absorbent core 110 and provide axial positioning to the absorbent core 110 to form an absorption section in the axial direction. In an optional specific example, the support member is a support tube, a spring, or an isolation block (for example, an isolation block made of foam ceramic material, which can also prevent fragments of the absorbent core 110 from escaping or foreign matter from entering the matrix 120). In some embodiments, the support member is located at one end of the core groove 121 close to the top. In other embodiments, the support member is located at one end of the core groove 121 away from the top.

[0062] In some embodiments, the control rod 10 further includes a fixing member 140. Fixing member 140 is used to secure the base 120 within the cladding 130. In the illustrated embodiment, fixing member 140 is a circular, pancake-shaped structure with multiple through-holes. The central through-hole is securely connected to the connecting portion 123 to secure the base 120 within the cladding 130, while the remaining through-holes allow coolant to flow into the cooling channel. It will be appreciated that in other embodiments, the shape of fixing member 140 is not limited to that described above, and the method of fixing member 140 and connecting portion 123 is not limited to that described above and may also be other methods. In some embodiments, fixing member 140 is made of zirconium alloy or stainless steel.

[0063] In some embodiments, the absorbent core 110 is rod-shaped, the diameter of the absorbent core 110 is 3mm to 15mm, and the length of the absorbent core 110 is 100mm to 900mm; the base 120 is cylindrical, the diameter of the base 120 is 35mm to 50mm, and the length of the base 120 is 200mm to 1000mm.

[0064] In some embodiments, when assembling the control rod 10, the absorbent core 110 is placed in the core groove 121 of the main body, and then the main body is fixedly connected to the top to form a base 120 equipped with the absorbent core 110; the top shell 133 and the middle section 132 are fixedly connected to form a shell that can accommodate the base 120; after the base 120 equipped with the absorbent core 110 is placed in the shell, the fixing part 140 is placed on the connecting part 123 of the base 120 equipped with the absorbent core 110 and covered with the bottom shell 131, and the bottom shell 131, the fixing part 140 and the shell are fixedly connected to accommodate the base 120 equipped with the absorbent core 110 in the shell 130 including the bottom shell 131, the middle section 132 and the top shell 133, and assembled to form the control rod 10.

[0065] In some embodiments, the reactor control assembly includes multiple control rods 10. Multiple control rods 10 are fixed to a bracket at intervals, forming a bundle of control rods 10. It is understood that the shape of the bracket is not particularly limited and can be configured based on the number of control rods 10 and the specific scenario. For example, the bracket can have four, five, six, or eight claws, with one control rod 10 fixed to each claw, or multiple control rods 10 fixed to each claw at intervals. It is understood that the number of control rods 10 on each claw can be equal or unequal. For another example, the bracket can be disc-shaped, with the control rods 10 arranged at equal or unequal intervals along the center of the disc.

[0066] The above reactor control assembly has at least the following advantages:

[0067] (1) A matrix 120 is provided between the cladding 130 and the absorbent core 110. The matrix 120 wraps the absorbent core 110 and at least partially fills the gap between the cladding 130 and the absorbent core 110, thereby making the integrity of the absorbent core 110 (for example, the absorbent core 110 using boron carbide as the absorbent material) less likely to be destroyed in a fast neutron environment and extending the life of the reactor control assembly.

[0068] (2) The matrix 120 can have a greater thickness and higher strength, which can significantly reduce the risk of damage to the cladding 130 caused by the interaction between the absorbent core 110 and the cladding 130, better accommodate the swelling of the absorbent core 110 during operation and the fragments generated by the breakage, thereby increasing the life of the control rod 10 and extending the life of the reactor control assembly.

[0069] (3) The material of the substrate 120 can be solid metal, so that the thermal conductivity of the substrate 120 is good, and the thermal stress on the absorption core 110 can be further reduced to increase the life of the control rod 10 and extend the life of the reactor control assembly.

[0070] In addition, one embodiment of the present application further provides a reactor control system, comprising a driving member and a reactor control assembly according to any of the above embodiments, wherein the driving member is configured to drive the reactor control assembly. The driving member drives the reactor control assembly to a predetermined position, thereby achieving its reaction control function.

[0071] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A control rod substrate, adapted to the absorbent core and cladding of the control rod, wherein a core groove is provided on the substrate for accommodating the absorbent core. When in use, the absorbent core is located in the core groove, and the substrate is located in the cladding.

2. The substrate according to claim 1, wherein The material of the substrate includes solid metal.

3. The substrate according to claim 1, wherein The material of the matrix includes one or more of a neutron absorbing material and a moderating material.

4. The substrate according to claim 3, characterized in that The moderator material includes one or more of zirconium hydride, yttrium hydride, graphite, beryllium and beryllium oxide.

5. The substrate according to any one of claims 1 to 4, characterized in that A cooling channel is also provided on the base, and the cooling channel is used to cool the absorbent core.

6. The substrate according to claim 5, characterized in that The base is columnar, and the cooling channel is located in the axial direction of the base.

7. The substrate according to any one of claims 1 to 6, characterized in that An air vent is provided on the base body and is communicated with the core groove.

8. The substrate according to claim 7, characterized in that The base includes a top and a main body. The core groove is a groove opened on the main body and open at one end. The opening of the groove faces the top. The air duct is located on the top.

9. The substrate according to any one of claims 1 to 8, characterized in that The base body is provided with a plurality of core grooves, the plurality of core grooves are arranged at intervals, and the absorbent core is located in each of the core grooves.

10. The substrate according to any one of claims 1 to 9, characterized in that The base body is provided with a plurality of cooling channels, and the plurality of cooling channels are arranged at intervals.

11. The substrate according to any one of claims 1 to 10, characterized in that The absorbent core is in a rod shape, and the peripheral surface of the absorbent core is in direct contact with the core groove.

12. The substrate according to any one of claims 1 to 10, characterized in that The base body further includes a connecting portion, and the connecting portion is used for fixed connection with the cladding.

13. A control rod comprising: absorbent core; The substrate according to any one of claims 1 to 11, wherein the absorbent core is located in the core groove of the substrate; and The substrate is located in the shell.

14. The control rod according to claim 13, wherein: The control rod includes a plurality of absorbent cores. The base body is provided with a plurality of core grooves, and each of the core grooves contains one absorbent core.

15. The control rod according to claim 13 or 14, characterized in that The control rod further comprises a support member, which is located in the core groove and is used to support the absorbent core and provide axial positioning for the absorbent core.

16. A reactor control assembly comprising: Bracket; and The control rod according to any one of claims 13 to 15, wherein the control rod is fixed to the bracket.

17. A reactor control system, characterized in that: It comprises the reactor control assembly according to claim 16 and a driving member, wherein the driving member is used to drive the reactor control assembly.

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