A nuclear reactor control rod assembly

Abstract

The present application relates to a nuclear reactor control rod assembly, comprising a control rod and a starting neutron source. The control rod is inserted into a nuclear reactor core to shut down the nuclear reactor, and the starting neutron source is disposed on the control rod, which is used to control the startup of the nuclear reactor. Thus, inserting the control rod with the starting neutron source into the nuclear reactor core can start the nuclear reactor. After the nuclear reactor is started, i.e., when the nuclear reactor is in an operating state, the control rod with the starting neutron source is pulled out of the nuclear reactor core so that the control rod is located above the nuclear reactor core. At this time, when the nuclear reactor is in an operating state, the control rod is located above the nuclear reactor core, preventing the starting neutron source from reacting with neutrons in the nuclear reactor core, thereby reducing the consumption of the starting neutron source and extending the service life of the starting neutron source, thereby meeting the startup and monitoring requirements of long-life advanced nuclear reactors.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear reactor startup neutron sources, and in particular to a nuclear reactor control rod assembly. Background Art

[0002] Before the initial operation of a nuclear reactor or after a long shutdown, the reactor core contains very few neutrons during the loading and startup process, making it difficult for neutron detectors to detect the neutron fluence rate within the reactor core. To enable neutron detectors to detect the neutron fluence rate within the reactor core, conventional techniques employ a fixed startup neutron source positioned within the reactor core. This source generates neutrons that, after undergoing critical multiplication, produce a sufficient number of neutrons for the neutron detectors to detect the neutron fluence rate within the reactor core. However, conventional techniques suffer from the significant consumption of the startup neutron source. Summary of the Invention

[0003] Based on this, it is necessary to provide a nuclear reactor control rod assembly to address the problem of huge consumption of starting neutron sources in traditional technologies.

[0004] In order to achieve the above-mentioned objectives, the present application provides a nuclear reactor control rod assembly, the nuclear reactor control rod assembly comprising:

[0005] control rods, the control rods being inserted into the core of a nuclear reactor to shut down the nuclear reactor;

[0006] A starting neutron source is provided on the control rod and is used to control the starting of the nuclear reactor.

[0007] In one embodiment, the control rod comprises:

[0008] A rod body, wherein the rod body is provided with a through hole extending along the axial direction of the rod body;

[0009] The neutron absorber is arranged in the through hole.

[0010] In one embodiment, the startup neutron source is disposed in the through hole.

[0011] In one embodiment, the neutron absorber includes a first sub-absorber and a second sub-absorber, and the first sub-absorber, the starting neutron source, and the second sub-absorber are arranged in sequence along the axial direction of the rod.

[0012] In one embodiment, the startup neutron source is coated on the outside of the neutron absorber.

[0013] In one embodiment, the starting neutron source is disposed outside the rod.

[0014] In one embodiment, the control rod assembly further includes a fixing ring, which is arranged around the outside of the rod body, and the starting neutron source is arranged on the fixing ring.

[0015] In one embodiment, the fixing ring is detachably connected to the rod body.

[0016] In one embodiment, the control rod assembly further includes a protective layer, which is coated on the outside of the startup neutron source.

[0017] In one embodiment, the material of the protective layer includes cadmium;

[0018] And / or, the material of the neutron absorber includes boron carbide and hafnium boride;

[0019] And / or, the material of the starting neutron source includes californium and antimony beryllium.

[0020] The nuclear reactor control rod assembly comprises a control rod and a starting neutron source. The control rod is inserted into the nuclear reactor core to shut down the nuclear reactor, and the starting neutron source is mounted on the control rod and used to control the startup of the nuclear reactor. Inserting the control rod with the starting neutron source into the nuclear reactor core enables startup of the nuclear reactor. After startup, i.e., when the nuclear reactor is in operation, the control rod with the starting neutron source is removed from the nuclear reactor core, positioned above the nuclear reactor core. When the nuclear reactor is in operation, the control rod is positioned above the nuclear reactor core, preventing the starting neutron source from reacting with neutrons in the nuclear reactor core. This reduces consumption of the starting neutron source and extends its service life, enabling the nuclear reactor to meet the startup and monitoring requirements of long-life advanced nuclear reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of a nuclear reactor control rod assembly provided in one embodiment of the present application;

[0022] Figure 2 for Figure 1 A top view of

[0023] Figure 3 A schematic structural diagram of another nuclear reactor control rod assembly provided in one embodiment of the present application;

[0024] Figure 4 for Figure 3 A top view of

[0025] Figure 5 A schematic structural diagram of another nuclear reactor control rod assembly provided in one embodiment of the present application;

[0026] Figure 6 for Figure 5 Top view of .

[0027] Description of reference numerals:

[0028] 100 - nuclear reactor control rod assembly; 110 - control rod; 111 - rod body; 1111 - through hole; 1112 - upper end; 1113 - lower end; 112 - neutron absorber; 1121 - first sub-absorber; 1122 - second sub-absorber; 120 - starting neutron source. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0030] In the description of the present application, it should be understood that 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application 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 a limitation on the present application.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0032] 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 or 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.

[0033] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, the first and second features may be directly connected, or the first and second features may be indirectly connected through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0035] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0036] As described in the background, conventional technologies suffer from significant neutron source consumption. This significant neutron source consumption is caused by the following: the startup neutron source is fixedly located within the nuclear reactor core. When the nuclear reactor is operating, the startup neutron source cannot be removed from the core, causing it to react with neutrons within the core, leading to significant consumption of the startup neutron source. When the nuclear reactor is shut down, this significant consumption of the startup neutron source can lead to a low activity level, preventing the reactor from starting, or preventing neutron detectors from detecting the neutron fluence level within the core.

[0037] It should be noted that during the process of loading and critical startup of the nuclear reactor, the startup neutron source can provide an effective response signal for the neutron detector, thereby realizing the functions of criticality monitoring and nuclear reactor protection.

[0038] The present application embodiment provides a nuclear reactor control rod assembly, see Figures 1-6 The nuclear reactor control rod assembly 100 includes a control rod 110 and a starting neutron source 120, wherein the control rod 110 is used to be inserted into the nuclear reactor core to shut down the nuclear reactor, and the starting neutron source 120 is set on the control rod 110, and the starting neutron source 120 is used to control the startup of the nuclear reactor.

[0039] Specifically, the nuclear reactor core refers to the area within a nuclear reactor where nuclear reactions occur and energy is generated. Control rods 110 equipped with a starting neutron source 120 are inserted into the nuclear reactor core to start the reactor. Once the reactor is started, i.e., when the reactor is in operation, control rods 110 equipped with a starting neutron source 120 are removed from the reactor core, positioning them at the top of the reactor core.

[0040] It should be noted that the startup neutron source 120 generally includes a primary neutron source and a secondary neutron source. The primary neutron source is typically used only during the first cycle of a nuclear reactor, while the secondary neutron source can only be activated as a neutron source after being irradiated within the reactor. Therefore, the secondary neutron source is placed in the first cycle to serve as the startup neutron source 120 for subsequent cycles. Simultaneously, the secondary neutron source in the subsequent cycle, after irradiation, continues to serve as the startup neutron source 120 for the next cycle, and so on. Conventional technology, which fixedly arranges the primary and secondary neutron sources within the nuclear reactor core, results in significant consumption of the startup neutron source 120 and cannot meet the requirements for restarting advanced nuclear reactors after shutdown. In addition, americium-beryllium sources and plutonium-beryllium sources, as common starting neutron sources 120, are prone to react with neutrons in the nuclear reactor core. If traditional technology is used to fix the americium-beryllium sources and plutonium-beryllium sources in the nuclear reactor core, there will be a problem of greater consumption of the starting neutron source 120. Therefore, in traditional technology, americium-beryllium sources and plutonium-beryllium sources cannot be used in fission nuclear reactors.

[0041] In the nuclear reactor control rod assembly 100 provided in an embodiment of the present application, when the nuclear reactor is in operation, the control rods 110 are located above the nuclear reactor core, preventing the startup neutron source 120 from reacting with neutrons in the nuclear reactor core. This reduces the consumption of the startup neutron source 120, thereby extending the service life of the startup neutron source 120 and enabling the nuclear reactor to meet the startup and monitoring requirements of long-life advanced nuclear reactors. Furthermore, by reducing the consumption of neutrons in the nuclear reactor core and the startup neutron source 120, the startup neutron source 120, which is easily reactive with neutrons, can be used in fission nuclear reactors, such as americium-beryllium sources and plutonium-beryllium sources. Furthermore, this increases the variety of startup neutron sources 120 available for use in fission nuclear reactors.

[0042] In one embodiment, see Figures 1-6 The control rod 110 includes a rod body 111 and a neutron absorber 112 , wherein the rod body 111 is provided with a through hole 1111 extending along its own axial direction, and the neutron absorber 112 is arranged in the through hole 1111 .

[0043] Specifically, control rod 110 includes a neutron absorber 112, which is disposed within a through hole 1111, which can be a cylindrical hole. When control rod 110 is inserted into the nuclear reactor core, neutron absorber 112 absorbs a large number of neutrons, preventing the fission chain reaction and thus shutting down the reactor. When control rod 110 is removed from the reactor core, the fission chain reaction is accelerated.

[0044] It should be noted that when the nuclear reactor control rod assembly 100 is inserted into an operating nuclear reactor, the number of neutrons generated by the startup neutron source 120 is relatively small, and the neutron absorber 112 can absorb a relatively large number of neutrons. Therefore, when the control rod 110 equipped with the startup neutron source 120 is inserted into the nuclear reactor core, the neutron absorber 112 can absorb neutrons in the nuclear reactor core to shut down the nuclear reactor, while the neutrons generated by the startup neutron source 120 do not affect the shutdown of the nuclear reactor. When the nuclear reactor control rod assembly 100 is inserted into a nuclear reactor to be started, the startup neutron source 120 emits neutrons in all directions, and only the neutrons that enter the neutron absorber 112 are absorbed. The remaining neutrons are sufficient to start the nuclear reactor. Therefore, when the control rod 110 equipped with the startup neutron source 120 is inserted into the nuclear reactor core, the startup neutron source 120 can control the startup of the nuclear reactor, while the neutron absorber 112 does not affect the startup of the nuclear reactor.

[0045] It is understood that the rod 111 is provided with a through hole 1111 extending along its axial direction, so that the rod 111 can accommodate the neutron absorber 112. By providing the neutron absorber 112, the neutron absorber 112 can absorb neutrons in the nuclear reactor core, thereby controlling the shutdown of the nuclear reactor.

[0046] In one embodiment, see Figure 1 、 Figure 2 、 Figure 5 and Figure 6 , the starting neutron source 120 is set in the through hole 1111.

[0047] It can be understood that by disposing the starting neutron source 120 within the through-hole 1111, the starting neutron source 120 and the control rod 110 are integrated. Consequently, after the nuclear reactor is started, the control rod 110, equipped with the starting neutron source 120, can be lifted out of the nuclear reactor core, positioning the control rod 110 above the nuclear reactor core. This reduces the risk of reactions between the starting neutron source 120 and neutrons in the nuclear reactor core, thereby reducing the consumption of the starting neutron source 120 and extending the service life of the starting neutron source 120, thus meeting the startup and monitoring requirements of long-life advanced nuclear reactors.

[0048] In one embodiment, see Figure 1 and Figure 2 The neutron absorber 112 includes a first sub-absorber 1121 and a second sub-absorber 1122 . The first sub-absorber 1121 , the starting neutron source 120 , and the second sub-absorber 1122 are arranged in sequence along the axial direction of the rod 111 .

[0049] In one example, the first sub-absorber 1121, the starting neutron source 120, and the second sub-absorber 1122 are arranged in sequence along the axial direction, and the first sub-absorber 1121 is set on one side of the starting neutron source 120 and is in contact with one end of the starting neutron source 120, and the second sub-absorber 1122 is set on the side of the starting neutron source 120 away from the first sub-absorber 1121 and is in contact with the other end of the starting neutron source 120.

[0050] It is understood that, in another example, the first sub-absorber 1121, the starting neutron source 120, and the second sub-absorber 1122 may be arranged sequentially along the axial direction such that the first sub-absorber 1121 is disposed on one side of the starting neutron source 120 and is spaced apart from one end of the starting neutron source 120, and the second sub-absorber 1122 is disposed on a side of the starting neutron source 120 away from the first sub-absorber 1121 and is also spaced apart from the other end of the starting neutron source 120. This embodiment of the present application does not limit the arrangement of the first sub-absorber 1121, the starting neutron source 120, and the second sub-absorber 1122 sequentially along the axial direction.

[0051] Specifically, the rod body 111 further includes an upper end 1112 and a lower end 1113, wherein the upper end 1112 is located on a side of the first sub-absorber 1121 away from the starting neutron source 120, and the lower end 1113 is located on a side of the second sub-absorber 1122 away from the starting neutron source 120. The first sub-absorber 1121, the starting neutron source 120, and the second sub-absorber 1122 are disposed within the through hole 1111, and the sizes of the first sub-absorber 1121, the starting neutron source 120, and the second sub-absorber 1122 can be adjusted according to the preset axial power of the nuclear reactor core.

[0052] It should be noted that the axial power distribution of a nuclear reactor significantly impacts its operation. Uneven axial power distribution can even jeopardize the safety of the entire reactor. In particular, the axial power distribution of a nuclear reactor varies with operating conditions, which has a particularly significant impact on the safety of an operating nuclear reactor. The axial power distribution is strongly affected by power level, burnup, transient toxicity distribution, and, in particular, the lifting and insertion of the control rod 110. The control rod 110 in the embodiment of the present application includes a first sub-absorber 1121, a starting neutron source 120, and a second sub-absorber 1122. Therefore, by adjusting the dimensions of the first sub-absorber 1121, the starting neutron source 120, and the second sub-absorber 1122, the axial power of the nuclear reactor core can be controlled.

[0053] It can be understood that the first sub-absorber 1121 and the second sub-absorber 1122 can absorb neutrons in the nuclear reactor core. When the nuclear reactor is operating, the control rod 110 equipped with the first sub-absorber 1121 and the second sub-absorber 1122 is inserted into the nuclear reactor core. The first sub-absorber 1121 and the second sub-absorber 1122 react with the neutrons in the nuclear reactor core, thereby shutting down the nuclear reactor.

[0054] In one embodiment, the startup neutron source 120 is wrapped around the outside of the neutron absorber 112 .

[0055] Specifically, the neutron absorber 112 and the starting neutron source 120 are both located between the upper end 1112 and the lower end 1113 of the rod body 111. The neutron absorber 112 is arranged in the through hole 1111 of the rod body 111, and the starting neutron source 120 is also arranged in the through hole 1111 of the rod body 111, and the starting neutron source 120 is covered on the outside of the neutron absorber 112. The sizes of the starting neutron source 120 and the neutron absorber 112 can be adjusted according to the preset axial power of the nuclear reactor core.

[0056] It should be noted that neutrons have strong penetrating power, and starting the neutron source 120 to cover the outside of the neutron absorber 112 does not affect the ability of the neutron absorber 112 to absorb neutrons.

[0057] It will be understood that the starting neutron source 120 is coated on the outside of the neutron absorber 112. The control rod 110 equipped with the starting neutron source 120 is inserted into the nuclear reactor core. The starting neutron source 120 can start the nuclear reactor. After the nuclear reactor is started, the control rod 110 equipped with the starting neutron source 120 is removed from the nuclear reactor core, and the nuclear reactor is now in operation. When the nuclear reactor needs to be shut down, the control rod 110 equipped with the neutron absorber 112 is inserted into the nuclear reactor core. The neutron absorber 112 can absorb neutrons in the nuclear reactor core, thereby shutting down the nuclear reactor.

[0058] In one embodiment, see Figure 3 and Figure 4 The starting neutron source 120 is disposed around the outside of the rod body 111 .

[0059] Specifically, the starting neutron source 120 is disposed around the outside of the rod 111. A neutron absorber 112 is disposed within a through hole 1111 on the rod 111. The neutron absorber 112 is located between an upper end 1112 and a lower end 1113 of the rod 111. The dimensions of the starting neutron source 120 and the neutron absorber 112 can be adjusted according to the preset axial power of the nuclear reactor core.

[0060] It is understood that by surrounding the starting neutron source 120 outside the rod body 111, the starting neutron source 120 and the control rod 110 are integrated. Consequently, after the nuclear reactor is started, the control rod 110, equipped with the starting neutron source 120, can be lifted out of the nuclear reactor core, positioning the control rod 110 above the nuclear reactor core. This reduces the risk of reactions between the starting neutron source 120 and neutrons in the nuclear reactor core, thereby reducing the consumption of the starting neutron source 120 and extending the service life of the starting neutron source 120, thus meeting the startup and monitoring requirements of long-life advanced nuclear reactors.

[0061] In one embodiment, see Figure 3 The control rod 110 assembly further includes a fixing ring (not shown), which is disposed around the outside of the rod body 111 , and the starting neutron source 120 is disposed on the fixing ring.

[0062] It can be understood that by providing a fixing ring, the starting neutron source 120 is disposed on the fixing ring, and the fixing ring is used to fix the starting neutron source 120 , thereby improving the stability of the starting neutron source 120 .

[0063] In one embodiment, see Figure 3 The fixing ring is detachably connected to the rod body 111.

[0064] For example, a buckle is provided on the fixing ring, and a slot is provided on the rod 111. By locking the buckle in the slot, the fixing ring and the rod 111 are connected together. It is understood that the fixing ring and the rod 111 can also be fastened by screws, and the embodiment of the present application does not limit the connection method of the fixing ring and the rod 111.

[0065] It is understandable that the fixing ring is detachably connected to the rod body 111 , which is easy to operate and can save time.

[0066] In one embodiment, the control rod 110 assembly further includes a protective layer, which covers the outer side of the startup neutron source 120 .

[0067] For example, in a thermal neutron reactor, some starting neutron sources 120 react significantly with thermal neutrons, such as americium-beryllium sources and plutonium-beryllium sources, but do not react much with fast neutrons. When a layer of material that absorbs thermal neutrons but not fast neutrons is coated on the outside of the starting neutron source 120, the consumption of the starting neutron source 120 can be reduced to a certain extent.

[0068] It is understandable that by providing a protective layer, the consumption of the startup neutron source 120 can be reduced to a certain extent, thereby extending the service life of the startup neutron source 120 and meeting the startup and supervision requirements of long-life advanced nuclear reactors.

[0069] In one embodiment, the material of the protection layer includes metal cadmium.

[0070] For example, when the protective layer is a cadmium coating, the cadmium coating can absorb thermal neutrons but not fast neutrons. When the nuclear reactor is a thermal neutron reactor, some starting neutron sources 120 react significantly with thermal neutrons. In this case, if a cadmium coating is applied to the outside of the starting neutron source 120, the consumption of the starting neutron source 120 can be reduced to a certain extent.

[0071] It is understandable that the choice of material for the protective layer may affect the degree of reaction between the protective layer and the startup neutron source 120 to a certain extent. Selecting a suitable material may reduce the consumption of the startup neutron source 120 to a greater extent.

[0072] In one embodiment, the material of the neutron absorber 112 includes boron carbide and hafnium boride.

[0073] For example, when the neutron absorber 112 is made of boron carbide, boron carbide has advantages such as a large neutron absorption cross section and good irradiation stability, and is a commonly used neutron absorption control material in nuclear reactors. It is understood that the material of the neutron absorber 112 can be high-boron steel, silver-indium-cadmium alloy, zirconium diboride, titanium diboride, hafnium diboride, gadolinium titanate, or dysprosium titanate, etc. This embodiment of the present application does not limit the type of neutron absorber 112.

[0074] It is understandable that the material of the neutron absorber 112 has a certain degree of influence on the ability of the neutron absorber 112 to absorb neutrons. Selecting a suitable material can make the neutron absorber 112 have better absorption ability, thereby making the control rod 110 have better control effect.

[0075] In one embodiment, the starting neutron source 120 is made of californium and antimony-beryllium.

[0076] Specifically, the material of the starting neutron source 120 can be californium, antimony beryllium, americium beryllium and plutonium beryllium, among which the starting neutron source 120 made of californium, antimony beryllium, americium beryllium and plutonium beryllium can be respectively called californium source, antimony beryllium source, americium beryllium source and plutonium beryllium source. Californium source is a primary neutron source, which is expensive and has a long half-life (the half-life of Cf-252 in californium source is about 2.6 years), and is usually used in the first cycle of nuclear reactors; antimony beryllium source is a secondary neutron source, which is cheap and has a short half-life (the half-life of Sb-124 in antimony beryllium source is 60.2d), and needs to be irradiated and activated in a nuclear reactor in advance for subsequent cycle use. Americium beryllium source has a long half-life (Am-241, Be-9, the half-life of Am-241 is 433 years), and plutonium beryllium source has a long half-life (Pu-238, Pu-239, Be-9, the half-life of Pu-238 is 87 years, and the half-life of Pu-239 is 24110 years). However, americium beryllium source and plutonium beryllium source easily react with neutrons in the nuclear reactor core.

[0077] It can be understood that by selecting the starting neutron source 120 made of appropriate material, the start-up of the nuclear reactor can be controlled.

[0078] 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.

[0079] 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 nuclear reactor control rod assembly, characterized in that: The nuclear reactor control rod assembly comprises: control rods, the control rods being inserted into the core of a nuclear reactor to shut down the nuclear reactor; a starting neutron source, the starting neutron source being disposed on the control rods and being used to control the startup of the nuclear reactor; The control rod includes a rod body and a neutron absorber; the rod body is provided with a through hole extending along its axial direction; the neutron absorber is arranged in the through hole; The starting neutron source is arranged in the through hole; The startup neutron source is coated on the outside of the neutron absorber.

2. The nuclear reactor control rod assembly according to claim 1, wherein: The neutron absorber includes a first sub-absorber and a second sub-absorber. The first sub-absorber, the startup neutron source, and the second sub-absorber are arranged in sequence along the axial direction of the rod.

3. The nuclear reactor control rod assembly according to claim 1, wherein: The starting neutron source is arranged around the outer side of the rod.

4. The nuclear reactor control rod assembly according to claim 3, wherein: The control rod assembly further includes a fixing ring, which is arranged around the outer side of the rod body, and the starting neutron source is arranged on the fixing ring.

5. The nuclear reactor control rod assembly according to claim 4, characterized in that: The fixing ring is detachably connected to the rod body.

6. The nuclear reactor control rod assembly according to any one of claims 1 to 5, characterized in that: The control rod assembly further includes a protective layer, which covers the outer side of the startup neutron source.

7. The nuclear reactor control rod assembly according to claim 6, characterized in that: The material of the protective layer includes cadmium; And / or, the material of the neutron absorber includes boron carbide and hafnium boride; And / or, the material of the starting neutron source includes californium and antimony beryllium.

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