阅读说明：本技术 一种核反应堆安全棒及核反应堆 (Nuclear reactor safety rod and nuclear reactor ) 是由 安伟健 葛攀和 郭键 胡古 薛慧哲 丁明哲 于 2021-08-27 设计创作，主要内容包括：本申请实施例公开了一种核反应堆安全棒及核反应堆,涉及核能技术领域,保证反应堆在发射掉落事故工况下的安全性,解决了安全棒抽离出堆芯后,核反应堆产生反应性不足的问题。该核反应堆安全棒包括控制反应段和跟随可燃段,其中,控制反应段,用于放置在核反应堆的堆芯内,使堆芯维持次临界状态；跟随可燃段,与控制反应段径向外轮廓和延伸方向一致,跟随可燃段的一端和控制反应段的一端固定,跟随可燃段具有与堆芯相同的燃料；当控制反应段从堆芯内抽离后,跟随可燃段位于堆芯内。本申请的核反应堆安全棒用于实现抽离后安全棒部分位于堆芯内提供燃料。(The embodiment of the application discloses nuclear reactor safety stick and nuclear reactor relates to nuclear energy technical field, guarantees the security of reactor under the accident operating mode that drops in the transmission, has solved the safety stick and has taken out the reactor core after, and nuclear reactor produces the not enough problem of reactivity. The nuclear reactor safety rod comprises a control reaction section and a following combustible section, wherein the control reaction section is used for being placed in a core of a nuclear reactor to enable the core to maintain a subcritical state; the following combustible section is consistent with the radial outer contour and the extension direction of the control reaction section, one end of the following combustible section and one end of the control reaction section are fixed, and the following combustible section has the same fuel as the reactor core; after the control reaction section is withdrawn from the core, the following combustible section is located in the core. The nuclear reactor safety rod is used for supplying fuel after the safety rod is partially positioned in a reactor core after the safety rod is drawn out.)

1. A nuclear reactor safety rod, comprising:

a control reaction section for placement within a core of a nuclear reactor to maintain the core in a subcritical state;

the follow-up combustible section is consistent with the radial outer contour and the extension direction of the control reaction section, one end of the follow-up combustible section and one end of the control reaction section are fixed, and the follow-up combustible section has the same fuel as the reactor core;

the following burnable segment is located within the core after the control reaction segment is withdrawn from the core.

2. The nuclear reactor safety rod of claim 1, wherein at least a portion of the outer surface of the following combustible section is coated with a layer of combustible toxins.

3. The nuclear reactor safety rod of claim 2, wherein a portion of an outer surface of the following burnable segment is coated with the burnable poison layer, the burnable poison layer corresponding to a central region of the core when the control reaction segment is withdrawn from the core and the following burnable segment is positioned within the core.

4. The nuclear reactor safety rod of claim 3, wherein the burnable poison layer completely coats an outer surface of the corresponding location of the trailing burnable segment.

5. The nuclear reactor safety rod of claim 3, wherein the control center region of the following burnable segment has a recess where the burnable poison layer is correspondingly coated, and an outer surface of the burnable poison layer is flush with an outer surface of a non-center region of the following burnable segment.

6. The nuclear reactor safety rod of claim 1, comprising an envelope made of a high temperature resistant material, the control reaction section and the follow-up burnable section being located within the envelope.

7. A nuclear reactor safety rod according to any one of claims 1 to 6, wherein the control reaction section and the follow-up flammable section are both cylindrical structures.

8. A nuclear reactor structure, comprising:

the reactor core is provided with a through hole in the center;

the nuclear reactor safety rod of any one of claims 1 to 7, being disposed through the through bore.

9. The nuclear reactor structure of claim 8, comprising a shield, wherein the shield is located at one end of the through hole of the core, the shield is provided with a avoiding hole corresponding to the through hole, an extending direction of the avoiding hole is consistent with an extending direction of the through hole, when the control reaction section of the nuclear reactor safety rod is extracted from the through hole, the control reaction section of the nuclear reactor safety rod extends into the avoiding hole, and the following combustible section of the nuclear reactor safety rod is located in the through hole.

10. The nuclear reactor structure of claim 8, wherein the core includes fuel assemblies and a reflective layer disposed about the periphery of the fuel assemblies.

Technical Field

The application relates to the technical field of nuclear energy, in particular to a nuclear reactor safety rod and a nuclear reactor.

Background

The reactor core of the nuclear reactor is also called as a reactor active area and consists of fuel assemblies arranged in a reactor core grid with a certain grid, control rods are arranged in the reactor core design schemes of a plurality of space nuclear reactors, and the safety rods are one of the control rods and are used for ensuring the safety of the reactor under the working condition of launching and dropping accidents, so that the reactor can still maintain a subcritical state even if water, wet sand and the like enter the reactor.

At present, the safety rods in the related art generally adopt two operation modes, one mode is that the safety rods are pulled out of the reactor core backwards and enter a shield body to become a part of shielding materials, and the other mode is that the safety rods are pulled out of the reactor core forwards to enable the reactor core to leave a reactor system and enter outer space.

Although the safety rod in the related art can ensure the safety of the reactor under the working condition of the accident of emission and drop, the problem of insufficient reactivity of the reactor after the safety rod is pulled out of the reactor core cannot be solved.

Disclosure of Invention

The embodiment of the application provides a nuclear reactor safety rod level nuclear reactor, guarantees the security of reactor under the transmission accident operating mode that drops, has solved the safety rod and has taken out the reactor core after, the nuclear reactor produces the not enough problem of reactivity.

In order to achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

the embodiment of the application provides a nuclear reactor safety rod, which comprises a control reaction section and a following combustible section, wherein the control reaction section is used for being placed in a core of a nuclear reactor to enable the core to maintain a subcritical state; the following combustible section and the control reaction section are consistent in radial outer contour and extension direction, one end of the following combustible section and one end of the control reaction section are fixed, and meanwhile the following combustible section has the same fuel as the reactor core; the following combustible segment is located within the core after the control reaction segment is withdrawn from the core.

In a first aspect, the present application provides a reactor safety rod, in which a control reaction section and a following combustible section are disposed on the reactor safety rod, when a nuclear reactor is not reacted, the control reaction section of the safety rod is located in a core of the nuclear reactor, so that the core is maintained in a subcritical state, and one end of the following combustible section is fixed to one end of the control reaction section, and has a radial outer contour and an extension direction. The safety rods adopted in the related art have two situations, one is that the safety rods directly enter the shielding body after being pulled out, and the other is that the safety rods directly enter the outer space after being pulled out, so that fuel cannot be provided for the reactor core after the safety rods are pulled out. Therefore, the reactor safety rod that this application provided makes control reaction section take out from the back through setting up control reaction section and following combustible section, follows combustible section and provides fuel for the reactor core in the reactor core, guarantees the security of reactor under the accident operating mode that drops in the transmission, has solved the safety rod and has taken out the reactor core after, the nuclear reactor produces the not enough problem of reactivity.

Furthermore, at least one part of the outer surface of the following combustible section is coated with the combustible poison layer, when the reaction section is controlled to be drawn out of the reactor core and then enters the reactor core along with the combustible section, the combustible poison layer coated on the periphery can reduce the power density of the central area of the reactor core and reduce the power non-uniform factor of the reactor, and the reactivity released when the combustible poison layer is consumed can also prolong the period of the reactor.

Further, a part of the outer surface of the following combustible section is coated with a combustible poison layer, and when the control reaction section is extracted from the reactor core and the following combustible section is positioned in the reactor core, the combustible poison layer corresponds to the central region of the reactor core. The combustible poison layer is arranged in the central area corresponding to the reactor core, so that the reactor core can be irradiated in a larger area due to the reactivity released when the combustible poison layer helps to teach consumption.

Furthermore, the burnable poison layer completely covers the outer surface of the corresponding position of the following burnable segment, so that after the burnable poison layer is consumed, the following burnable segment can provide the same fuel as the reactor core for the nuclear reactor, and the reaction time of the nuclear reactor is prolonged.

Furthermore, the control center area of the following combustible section is provided with a concave part, the combustible poison layer is correspondingly coated at the concave part, the outer surface of the combustible poison layer is flush with the outer surface of the non-center area of the following combustible section, the control reaction section is conveniently and rapidly drawn out of the reactor core, and the following combustible section can smoothly enter the reactor core.

Further, the nuclear reaction safety rod comprises a cladding made of high-temperature resistant materials, and the control reaction section and the following combustible section are located in the cladding.

Further, the control reaction section and the following combustible section are both cylindrical structures.

In a second aspect, embodiments of the present application provide a nuclear reactor structure, which includes a core, a through hole is provided at a central position of the core, and the nuclear reactor safety rod provided in the embodiments of the first aspect, wherein the nuclear reactor safety rod is inserted into the through hole of the core.

The nuclear reactor structure that this application embodiment provided, owing to included the nuclear reactor safety stick of any embodiment of the first aspect, consequently have same technological effect, promptly, guarantee the security of reactor under the accident operating mode is dropped in the transmission, solved the safety stick and taken out the reactor core after, the nuclear reactor produces the not enough problem of reactivity.

Further, nuclear reactor includes the shield, and the shield is located the one end of the through-hole of reactor core, and the shield corresponds the through-hole and is equipped with dodges the hole, and the extending direction who dodges the hole is unanimous with the extending direction of through-hole, and after the control reaction section of nuclear reactor safety stick was taken out from the through-hole, the control reaction section of nuclear reactor safety stick stretched into dodge downtheholely, and the following combustible section of nuclear reactor safety stick is located the through-hole. The shield is provided with the avoidance hole which is consistent with the extension direction of the reactor core through hole, so that the reaction section can be controlled to enter the avoidance hole, the reaction section becomes a part of the shield, and the shielding function is provided.

Further, the core includes fuel assemblies and a reflective layer disposed at a periphery of the fuel assemblies.

Drawings

FIG. 1 is a diagram of a related art 1 st mode of operation safety rod in a core;

FIG. 2 is a diagram illustrating a state where a safety rod is withdrawn from a core and enters a shield in the 1 st operation mode of the related art;

FIG. 3 is a diagram of a related art 2 nd mode of operation safety rod in a core;

FIG. 4 is a diagram of a related art 2 nd mode of operation with the safety rods withdrawn from the core;

FIG. 5 is a schematic illustration of a nuclear reactor safety rod according to the present application;

FIG. 6 is a cross-sectional view of a nuclear reactor safety rod of the present application;

FIG. 7 is a cross-sectional view of one embodiment of a nuclear reactor safety rod of the present application;

FIG. 8 is a cross-sectional view of a nuclear reactor safety rod of the present application;

FIG. 9 is a view of a nuclear reactor safety rod of the present application in position within a core;

FIG. 10 is a state diagram of a nuclear reactor safety rod of the present application being withdrawn from a core;

description of reference numerals:

1-a safety bar; 11-controlling the reaction section; 12-following the combustible section; 121-a recess; 1211-a combustible poison layer; 13-cladding; 2, a reactor core; 21-a fuel assembly; 211-a central region; 212-a via; 22-a reflective layer; 3-a shield; 31-relief holes.

Detailed Description

It should be noted that, in the present application, technical features in examples and embodiments may be combined with each other without conflict, and the detailed description in the specific embodiment should be understood as an explanation of the gist of the present application and should not be construed as an improper limitation to the present application.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, specific technical solutions of the present application will be described in further detail below with reference to the accompanying drawings in the embodiments of the present application. The following examples are intended to illustrate the present application but are not intended to limit the scope of the present application.

In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present application, "a plurality" means two or more unless otherwise specified.

In addition, in the embodiments of the present application, directional terms such as "upper", "lower", "left", and "right" are defined with respect to the schematically-placed orientation of components in the drawings, and it is to be understood that these directional terms are relative concepts, which are used for descriptive and clarifying purposes, and may be changed accordingly according to changes in the orientation in which the components are placed in the drawings.

In the embodiments of the present application, unless otherwise explicitly specified or limited, the term "connected" is to be understood broadly, for example, "connected" may be a fixed connection, a detachable connection, or an integral body; may be directly connected or indirectly connected through an intermediate.

In the embodiments of the present application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

Nuclear reactors, also known as nuclear reactors, are devices that can sustain a controlled, self-sustaining nuclear fission reaction to harness nuclear energy. Nuclear reactors, known as the hearts of nuclear power plants, are designed to allow the self-sustaining fission chain fission process to occur without the need for supplemental neutron sources by properly arranging the nuclear fuel.

The core of a nuclear reactor, also called a reactor active region, is composed of fuel assemblies arranged in a core grid having a certain grid, and includes a structure, control rods, a shield, and the like, in addition to the core, wherein the structure includes a fuel cladding, the core grid for arranging the core, a reactor vessel, and the like, and the shield attenuates various rays generated from the reactor core, so that neutrons generated from the core during a reactor reaction can be decelerated and absorbed by the shield. The control rods play the roles of compensating and adjusting the neutron reactivity and emergently stopping the reactor. The control rod can be divided into a compensation rod, an adjusting rod and a safety rod according to the action, and the safety rod is mainly used for ensuring the safety of the reactor under the accident working condition of launching and dropping, so that the reactor can still maintain the subcritical state even if entering water, wet sand and the like.

The nuclear reactor safety rod 1 provided by the embodiment of the application, as shown in fig. 5 and 9, comprises a control reaction section 11 and a following combustible section 12, wherein the control reaction section 11 is used for being placed in a core 2 of a nuclear reactor to maintain the core 2 in a subcritical state; the following combustible section 12 and the control reaction section 11 have the same radial outer contour and the same extension direction, one end of the following combustible section 12 and one end of the control reaction section 11 are fixed, and the following combustible section 12 has the same fuel as the reactor core 2; when the control reaction section 11 is withdrawn from the core 2, the following combustible section 12 is located within the core 2.

In the related art, the safety rod 1 is located in the core 2 when the space nuclear reactor is launched, and when the space nuclear reactor is successfully launched and ready to be started, the safety rod 1 is drawn out of the core 2, and the reactor starts to operate under the action of a control mechanism. At the present stage, there are two operation modes of the safety rod 1, one of which is shown in fig. 1 and 2, the safety rod 1 is located in the core 2 during the launching, and when the reactor is ready to start after the successful launching, the safety rod 1 is drawn out of the core 2 and enters the shield 3 to become a part of the shielding material to provide a partial shielding function. In another mode of operation, as shown in figures 3 and 4, the safety rods 1 are located within the core 2 during launch, and when the reactor is ready to be started after successful launch, the safety rods 1 are drawn forward out of the core 2 and out of the reactor system into outer space. In the technical solution provided by the present application, as shown in fig. 9 and 10, a control reaction section 11 and a following combustible section 12 are disposed on a reactor safety rod 1, when a nuclear reactor is not reacted, the control reaction section 11 of the safety rod 1 is located in a core 2 of the nuclear reactor, so that the core 2 maintains a subcritical state, one end of the following combustible section 12 is fixed to one end of the control reaction section 11, and has a radial outer contour and an extending direction, when the nuclear reactor is ready to react, the control reaction section 11 is extracted from the core 2, the following combustible section 12 falls in the core 2, and the following combustible section 12 has the same fuel as that of the core 2, so that the control reaction section 11 is extracted from the core 2 and then the following combustible section 12 can further continuously provide fuel for the core 2 of the nuclear reactor. After the control reaction section 11 is pulled out, the following combustible section 12 falls into the reactor core 2 to provide fuel for the reactor core 2, the safety of the reactor under the accident condition of falling during launching is ensured, and the problem of insufficient reactivity of the reactor after the safety rod 1 is pulled out of the reactor core 2 is solved.

In some embodiments, as shown in fig. 7 and 10, in the nuclear reactor, burnable poison has the advantages of compensating the reactivity of the nuclear reactor, prolonging the life of the core 2, reducing the number of movable control rods and reducing the power density of the central region 211 of the core 2, and reducing the power distribution of the reactor, so that, preferably, in the technical solution of the nuclear reactor safety rod 1 of the present application, at least a part of the outer surface-clad burnable poison layer 1211 is disposed in the following burnable segment 12, and when the control reaction segment 11 is withdrawn from the core 2 and then falls into the core 2 along with the burnable segment 12, the outer-clad burnable poison layer 1211 can not only reduce the power density of the central region 211 of the core 2, reduce the power non-uniformity factor of the reactor, but also prolong the period of the reactor due to the reactivity released when the burnable poison layer 1211 is consumed.

For example, as shown in fig. 9 and 10, when the following burnable segment 12 has the same material as the fuel, the burnable poison may reduce the power density of the central region 211 of the core 2, reduce the power non-uniformity factor of the reactor, and prevent the following burnable segment 12 from providing fuel to the core 2 if the outer surface of the following burnable segment 12 is entirely coated with the burnable poison layer 1211. If the burnable poison layer 1211 is coated on the outer surface of the portion, which is arranged along with the burnable segment 12, so that the combination of the two effects is optimized, the following burnable segment 12 can be used for providing fuel for the reactor core 2, the fuel loading capacity is reduced, the weight and the volume of the reactor are reduced, and the burnable poison layer 1211 can be used for reducing the power non-uniformity factor of the reactor, therefore, the technical scheme provided by the application is that the burnable poison layer 1211 is coated on a portion of the outer surface of the following burnable segment 12, when the control reaction segment 11 is withdrawn from the reactor core 2 and the following burnable segment 12 is located in the reactor core 2, the burnable poison layer 1211 corresponds to the central region 211 of the reactor core 2, and the burnable poison layer 1211 is arranged in the central region 211 of the corresponding to the reactor core 2. The reactivity, which is advantageous to be released when the burnable poison layer 1211 is consumed, may radiate the core 2 in a wider and wider area, and meanwhile, both ends of the following burnable segment 12 are not covered by the burnable poison layer 1211, and when the burnable poison layer 1211 is consumed, both ends of the following burnable segment 12 may also provide fuel for the core 2, thereby maximizing the effect and function.

In other embodiments, as shown in fig. 7 and 10, the burnable poison layer 1211 may cover a part of the following burnable segment 12 and may cover a whole part of the following burnable segment 12, if the outer surface of the corresponding position of the following burnable segment 12 is not completely covered, there is a phenomenon of partial covering and partial uncovering, which results in that the outer surface of the corresponding position of the burnable poison layer 1211 cannot form a continuous covering, which is not favorable for uniform consumption of the burnable poison layer 1211, and if the burnable poison layer 1211 is completely covered on the outer surface of the corresponding position of the following burnable segment 12, the outer surface of the burnable poison 1211 forms a complete covering, when the control reaction segment 11 is withdrawn from the core 2, the following burnable segment 12 enters the core 2, the outer surface of the burnable poison layer 1211 forms a complete covering, the burnable poison layer 1211 is in uniform contact with the core 2, which is favorable for uniform consumption of the burnable poison 1211, and the following burnable segment 12 is completely exposed after the uniform consumption is completed, the same fuel as the core 2 is supplied to the nuclear reactor, and the reaction time of the nuclear reactor is prolonged.

It should be noted that, as shown in fig. 7 and 10, if the combustible toxin layer 1211 wraps the whole section of the following combustible section 12, it is ensured that the outer contour of the following combustible section 12 is consistent with that of the reaction control section. In order to maximize the effect, the present application coats a portion of the outer surface of the following burnable segment 12 with the burnable poison layer 1211, and when the control reaction segment 11 is withdrawn from the core 2 and the following burnable segment 12 is located in the core 2, the burnable poison layer 1211 corresponds to the central region 211 of the core 2, and the burnable poison layer 1211 is disposed corresponding to the central region 211 of the core 2. If the combustible poison layer 1211 is wrapped around the control center region 211 of the following combustible segment 12, the outer contour of the control center region 211 wrapped around the combustible poison layer 1211 is larger than the non-center region 211 of the following combustible segment 12, and the control reaction segment 11 is drawn out of the core 2, the two sections of the control center region 211 of the following combustible segment 12 are provided with bosses, so that resistance is provided for the following combustible segment 12 to enter the core 2. In order to solve the problem, the application provides a technical scheme that a concave part 121 is arranged in a control area of a following combustible section 12, a combustible poison layer 1211 is correspondingly coated at the corresponding concave part 121, the outer surface of the combustible poison layer 1211 is flush with the outer surface of a non-central area 211 of the following combustible section 12, the whole section of the following combustible section 12 is consistent with the outer contour of a reflection control section, after a control reaction section 11 is drawn out of a reactor core 2, the following combustible section 12 can smoothly and quickly enter the reactor core 2, and resistance generated by coating the combustible poison layer 1211 in the control central area 211 of the following combustible section 12 to form a boss does not need to be overcome.

Specifically, as shown in fig. 8, a cladding 13 should be disposed on the periphery of the safety rod 1, and the control reaction section 11 and the following combustible section 12 should be located in the cladding 13, so as to avoid the reaction with the outside during the manufacturing and using processes, thereby generating impurities which are not beneficial to the reaction of the nuclear reactor. It should be added that the material of the cladding 13 may be selected according to the operating temperature of the reactor, so as to avoid melting the cladding 13 due to the excessive reaction temperature of the nuclear reactor, and the cladding 13 is generally made of high temperature resistant stainless steel or refractory metal alloy.

For example, as shown in fig. 6 and 7, when the nuclear reactor is ready to react, it is necessary to withdraw the control reaction section 11 from the core 2, to make the following combustible section 12 enter the core 2, the friction between the core 2 and the core 2 needs to be overcome during the withdrawal, the magnitude of which depends in part on the shape of the control reaction section 11 and the following combustible section 12, if the control reaction section 11 and the following combustible section 12 are shaped as a square, the outer surface of the square has edges and corners, when the core 2 is drawn out, the friction force of the edges and corners needs to be overcome, if the control reaction section 11 and the follow-up combustible section 12 are shaped as spheres, although the outer surface of the ball body is smooth and has no edges and corners, the friction force of the edges and corners does not need to be overcome additionally, however, the contact surface between the spherical outer surface and the core 2 is small, and the function of following the combustible segment 12 in the core 2 cannot be realized. If the control reaction section 11 and the following combustible section 12 are designed to be cylindrical structures, there is no corner similar to a tetragonal structure, and there is no need to additionally overcome the friction force of the corner, and there is no small contact surface between the outer surface of the sphere and the core 2, preferably, the technical solution proposed in the present application is to set both the control reaction section 11 and the following combustible section 12 to be cylindrical structures.

Further, as shown in fig. 9 and 10, the present application also provides a reactor structure, which includes a core 2 and a nuclear reactor safety rod 1, and a through hole 212 is provided at a central position of the core 2, and the nuclear reactor safety rod 1 is inserted into the through hole 212 of the core 2, because the safety rod 1 has the safety of ensuring that the reactor falls under the working condition when being launched, the problem of insufficient reactivity of the nuclear reactor after the safety rod 1 is pulled out of the core 2 is solved. Generally, the safety rods 1 are prepared before the core 2 is prepared, and the safety rods 1 are directly placed in the core 2 when the core 2 is prepared, so that the nuclear reactor manufacturing time is long, and the friction force to be overcome when the safety rods 1 are pulled out is large. If the through hole 212 is formed in the central region 211 of the core 2, the core 2 and the nuclear reactor safety rod 1 are simultaneously fabricated, and finally the nuclear reactor safety rod 1 is inserted into the through hole 212 of the core 2. Saving the manufacturing time of the nuclear reactor.

It should be noted that, as shown in fig. 10, the nuclear reactor includes a shield 3 in addition to the core 2 and the nuclear reactor safety rod 1, the shield 3 is disposed at one end of the through hole 212 of the core 2, the shielding 3 is disposed with the avoiding hole 31 at a position corresponding to the through hole 212, an extending direction of the avoiding hole 31 is identical to an extending direction of the through hole 212, when the control reaction section 11 of the nuclear reactor is withdrawn from the through hole 212, the control reaction section 11 of the nuclear reactor safety rod 1 extends into the avoiding hole 31, and the following combustible section 12 of the nuclear reactor safety rod 1 is disposed in the through hole 212. The shield 3 is provided with the avoiding hole 31 which is consistent with the extending direction of the through hole 212 of the reactor core 2, thereby being beneficial to controlling the reaction section 11 to enter the avoiding hole 31, becoming a part of the shield 3 and providing a shielding function.

Further, as shown in fig. 10, the fuel assemblies 21 in the core 2 may leak neutron substances during the nuclear reactor reaction, which may waste energy of the nuclear reactor reaction and may not meet the required nuclear energy requirement. Therefore, in the present invention, the reflecting layer 22 is provided on the periphery of the fuel assemblies 21 in the reactor core 2, and the material for reflecting neutrons leaked from the inside of the fuel assemblies 21 is surrounded on the outside of the reactor core 2, so that the leakage of neutrons in the fuel assemblies 21 can be reduced, the fuel can be reduced, the average output power of the reactor can be improved, and the operating life of the nuclear reactor can be prolonged.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.