Reactor and its shielding components

Abstract

A reactor (1) and a shielding assembly (10) thereof. The reactor (1) comprises a reactor container (20) and a core (30) arranged in the reactor container (20), and the shielding assembly (10) comprises: a first mounting plate (121) mounted in the reactor container (20); a second mounting plate (122) mounted in the reactor container (20), and a portion between the first mounting plate (121) and the second mounting plate (122) is used to accommodate a portion of a shielding device (125), and the shielding device (125) is used to shield neutrons generated by the core (30); and a fixing member (126) fixedly connected to the first mounting plate (121) and the second mounting plate (122). The shielding assembly (10) and the reactor (1) are fixedly connected to the first mounting plate (121) and the second mounting plate (122) by the fixing member (126), so that the overall structure is stable, the anti-seismic effect is good, and the safety of the reactor can be ensured.

Description

Technical Field

[0001] The present application relates to the field of reactor technology, and in particular to a reactor and a shielding component thereof. Background Art

[0002] A reactor, also known as an atomic reactor or a nuclear reactor, is a device that can maintain a controllable self-sustaining chain nuclear fission reaction to achieve nuclear energy utilization. The core of the reactor will produce neutrons during the nuclear reaction. The reactor in the related art has a shielding component for shielding neutrons. However, the stability of this shielding component is not strong, so the safety of the reactor cannot be guaranteed. Summary of the invention

[0003] On the one hand, the present application provides a shielding assembly for a reactor, wherein the reactor includes a reactor container and a core arranged in the reactor container, and the shielding assembly includes: a first mounting plate installed in the reactor container; a second mounting plate installed in the reactor container, and the first mounting plate and the second mounting plate are used to accommodate a part of a shielding device, and the shielding device is used to shield neutrons generated by the core; a fixing member fixedly connecting the first mounting plate and the second mounting plate.

[0004] On the other hand, the present application provides a reactor, comprising: a reactor container; a core, arranged in the reactor container; a shielding assembly, a first mounting plate and a second mounting plate of the shielding assembly are installed in the reactor container, and a shielding device of the shielding assembly is used to shield neutrons generated by the core. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Other objects and advantages of the present invention will become apparent from the following description of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.

[0006] Figure 1 is a schematic structural diagram of a reactor according to an embodiment of the present application;

[0007] Figure 2 is an assembly diagram of a first mounting plate, a second mounting plate, and a fixing member according to an embodiment of the present application;

[0008] Figure 3 is an assembly diagram of a first mounting plate and a connecting member according to an embodiment of the present application;

[0009] Figure 4 is an assembly diagram of a first mounting plate, a first fastener, and an outer cylinder according to an embodiment of the present application;

[0010] Figure 5 is an assembly diagram of a second mounting plate, a second fastener, and an inner cylinder according to an embodiment of the present application;

[0011] Figure 6 It is an assembly diagram of a first mounting plate, a third fastener, and a filling piece according to an embodiment of the present application.

[0012] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding.

[0013] Description of reference numerals:

[0014] 1. Reactor; 10. Shielding assembly; 101. Radial outer shield; 102. Radial inner shield; 103. Middle shield; 104. Upper shield; 105. Lower shield; 20. Reactor vessel; 30. Reactor core; 40. Intermediate heat exchanger; 50. Grid header; 60. Drive unit; 70. In-core support; 71. Support upper plate; 72. Support plate; 73. Support bottom plate; 121. First mounting plate; 122. Second mounting plate; 123. Third mounting plate; 124. Fourth mounting plate; 125. Shielding device; 126. Fixing member; 127. Connecting member; 107. Outer cylinder; 106. Inner cylinder; 181. First fastener; 182. Second fastener; 183. Third fastener; 184. Filling member. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiment is one embodiment of the present invention, not all embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0017] The embodiment of the present application first provides a shielding assembly 10 of a reactor 1. Figure 1 is a schematic structural diagram of a reactor 1 according to an embodiment of the present application; Figure 2 is an assembly diagram of a first mounting plate 121, a second mounting plate 122, and a fixing member 126 according to an embodiment of the present application; Figure 3 is an assembly diagram of a first mounting plate 121 and a connecting member 127 according to an embodiment of the present application; Figure 4 is an assembly diagram of the first mounting plate 121, the first fastener 181 and the outer cylinder 107 according to one embodiment of the present application; Figure 5 is an assembly diagram of the second mounting plate 122, the second fastener 182, and the inner cylinder 106 according to one embodiment of the present application; Figure 6 1 is an assembly diagram of a first mounting plate 121 , a third fastener 183 , and a filler 184 according to an embodiment of the present application.

[0018] The reactor 1 includes a reactor container 20 and a reactor core 30 disposed in the reactor container 20 . The shielding assembly 10 includes a first mounting plate 121 , a second mounting plate 122 and a fixing member 126 .

[0019] A first mounting plate 121 is installed in the stack container 20; a second mounting plate 122 is installed in the stack container 20, and a portion of a shielding device 125 is accommodated between the first mounting plate 121 and the second mounting plate 122, and the shielding device 125 is used to shield neutrons generated by the core 30; a fixing member 126 is fixedly connected to the first mounting plate 121 and the second mounting plate 122.

[0020] The shielding device 125 can shield the neutrons generated by the core 30 by reflecting and / or moderating the neutrons. For example, the shielding device 125 can be composed of a plurality of shielding members, and the plurality of shielding members form a multi-ring structure. The shielding device 125 can include stainless steel shielding members and / or graphite shielding members, and each circle of stainless steel shielding members is composed of a plurality of stainless steel rods in a circle. The outer side of each stainless steel rod is covered with a steel pipe, and each circle of graphite shielding members is composed of a plurality of graphite rods in a circle. The outer side of each graphite rod is covered with a steel pipe. The main function of the stainless steel rod is to reflect neutrons (the collision between the stainless steel rod and the neutron, if it is an elastic collision, the neutron is reflected macroscopically; if it is an inelastic collision, the neutron will lose some energy and slow down). The function of the graphite rod is to moderate the neutron; that is, it will make the neutron energy lower and the speed slower. The smaller the neutron energy, the easier it is to have the required and monitorable reaction, so the presence of the graphite rod is more conducive to neutron monitoring. Moreover, the smaller the neutron energy, the less likely it is to escape, which can reduce neutron leakage and thus improve the efficiency of neutron utilization in the core. The graphite rods can be boron-containing graphite shielding rods, and these boron-containing graphite shielding rods and stainless steel rods can be arranged in an equilateral triangle to form a closed radiation protection structure to enhance the shielding effect. That is, three adjacent boron-containing graphite shielding rods and stainless steel rods are arranged in an equilateral triangle. The fixing of these shielding rods in the reactor is safe and reliable.

[0021] In some embodiments, the first mounting plate 121 is formed by splicing a plurality of sub-mounting plates, and the shielding assembly 10 includes a connector 127, which connects the plurality of sub-mounting plates so that the first mounting plate 121 formed by splicing the plurality of sub-mounting plates closes the upper end of the accommodating space. In this way, not only the shielding effect is ensured, but also the structural strength of the first mounting plate 121 can be improved. The connector 127 (which can be a bolt) is used to connect the divided first mounting plates 121 and fix the sub-mounting plates on the first mounting plate 121. The direct fit between the shielding rod and the sub-mounting plate can be a clearance fit. During an earthquake, the horizontal force is transmitted to the shielding rod, and the connector 127 is not subjected to force; during the earthquake condition SL-2, the vertical direction is subjected to the upward pulling force of the sub-mounting plate.

[0022] In the related art, the first mounting plate and the second mounting plate are directly connected to the stack container, and there is a lack of connection between the first mounting plate and the second mounting plate, so that the structure is unstable. However, the shielding assembly 10 provided in the embodiment of the present application is fixedly connected to the first mounting plate 121 and the second mounting plate 122 by the fixing member 126, so that the overall structure is stable and has good earthquake resistance, which can ensure the safety of the reactor. Under earthquake conditions, the horizontal earthquake force is transmitted to the fixing member 126 (which can be a stud) through the first mounting plate 121 and the second mounting plate 122, and the fixing member 126 is subjected to bending stress; under the earthquake condition SL-1, the fixing member 126 is not subjected to force in the vertical direction; under the earthquake condition SL-2, the fixing member 126 is subjected to tension in the vertical direction.

[0023] The reactor 1 may be a fast reactor, for example, a sodium-cooled fast reactor. The sodium-cooled fast reactor may include a reactor vessel 20, a reactor core 30 disposed in the reactor vessel 20, an intermediate heat exchanger 40, a grid header 50, and a driving unit 60 for driving the flow of liquid sodium.

[0024] In some embodiments, the second mounting plate 122 is disposed below the first mounting plate 121, and the shielding assembly 10 further includes a third mounting plate 123 and a fourth mounting plate 124. The third mounting plate 123 is mounted in the stack container 20 and is located below the second mounting plate 122; the fourth mounting plate 124 is mounted in the stack container 20 and is located below the third mounting plate 123; and the space between the second mounting plate 122 and the third mounting plate 123 and between the third mounting plate 123 and the fourth mounting plate 124 is used to accommodate another partial shielding device 125, and the first mounting plate 121, the second mounting plate 122, the third mounting plate 123, the fourth mounting plate 124, the partial shielding device 125 and the other partial shielding device 125 form an accommodating space for accommodating the core 30. As a result, the shielding assembly 10 has a better shielding effect, and the reactor 1 has a higher space utilization rate.

[0025] That is, the shielding assembly 10 may include: a radial outer shield 101 (composed of a third mounting plate 123, a fourth mounting plate 124, and a shielding device 125 disposed between the third mounting plate 123 and the fourth mounting plate 124) disposed at the radial periphery of the core 30 and extending in the axial direction. In some embodiments, the shielding assembly 10 may also include a radial inner shield 102, which is disposed between the core 30 and the radial outer shield 101 and is used to reflect neutrons. The radial inner shield 102 is the first radial shield located outside the core shroud. The radial inner shield 102 may be made of stainless steel. In the embodiment shown in the figure, the radial inner shield 102 is formed by rolling and welding multiple layers of stainless steel plates into a concentric sleeve. The lower portion of the radial inner shield 102 is provided with a plurality of through holes for fluid flow.

[0026] The radial outer shield 101 and the radial inner shield 102 together form a shield to block radiation in the radial direction, and play the role of ensuring the maximum neutron injection rate in the intermediate heat exchanger 40. According to the requirements of the in-pile ionization chamber and the out-pile detector for neutron detection, it is necessary to open a hole in the radial inner shield 102, and the radial outer shield 101 is set to a structure with an opening. On the radial outer side of the radial outer shield 101 facing the side wall of the drive unit 60, a stainless steel shielding layer is provided to reduce the radiation of neutrons to the drive unit 60.

[0027] The lower end of the radial inner shield 102 is substantially flush with the lower end of the radial outer shield 101 , and both are lower than the lower end of the core 30 ; the upper end of the radial inner shield 102 is higher than the upper end of the core 30 ; the upper end of the radial inner shield 102 is higher than the upper end of the radial outer shield 101 .

[0028] The shielding assembly 10 further includes: a middle shield 103 (composed of a second mounting plate 122, a third mounting plate 123, and a shielding device 125 disposed between the second mounting plate 122 and the third mounting plate 123) disposed above the radial outer shield 101, and the upper end of the middle shield 103 is higher than the upper end of the radial inner shield 102. The middle shield 103 may have the same structure as the radial outer shield 101. It can be understood by those skilled in the art that the radial outer shield 101 and the middle shield 103 may be provided as one body in theory, and the middle shield 103 is an extension of the radial outer shield 101, but due to the limitation of the processing technology, the radial outer shield 101 and the middle shield 103 are provided separately. The number of turns of the shielding devices of the radial outer shield 101 and the middle shield 103 may be 3 to 6 turns, such as 4 or 5 turns. It is easy for those skilled in the art to understand that the structures of the radial outer shield 101 and the middle shield 103 are similar or the same, but the heights may be different.

[0029] The shielding assembly 10 may also include an upper shield 104 (composed of a first mounting plate 121, a second mounting plate 122, and a shielding device 125 disposed between the first mounting plate 121 and the second mounting plate 122) disposed above the middle shield 103, which is used to prevent neutrons from leaking from the upper oblique direction into the intermediate heat exchanger 40 and the upper part of the independent heat exchanger, thereby reducing the secondary sodium activity.

[0030] In some embodiments, the upper shield 104 may include multiple circles of stainless steel shields (the shielding device may include stainless steel shields and / or graphite shields), each circle of stainless steel shields is composed of multiple stainless steel rods arranged in a circle, and each stainless steel rod is covered with a steel pipe.

[0031] The shielding assembly 10 may further include an outer cylinder 107, which is disposed in the stack container 20 and outside the accommodation space, and the outer cylinder 107 is connected to the first mounting plate 121 via a first fastener 181. The first fastener 181 may be a bolt, thereby stabilizing the overall structure. The first fastener 181 is used to fix the first mounting plate 121 to the outer cylinder 107. During an earthquake, the horizontal seismic force acts on the first mounting plate 121 and is then transferred to the first fastener 181, and the first fastener 181 is subjected to a horizontal shear force; during the earthquake condition SL-2, the first fastener 181 is subjected to an upward pulling force from the first mounting plate 121 in the vertical direction.

[0032] In some embodiments, the outer cylinder 107 may be an outer steel cylinder disposed radially outside the upper shield 104 , and is used to fix the middle shield 103 and the upper shield 104 .

[0033] The shielding assembly 10 may further include an inner cylinder 106, the inner cylinder 106 being disposed in the accommodating space, a bracket being formed on the outer surface of the inner cylinder 106, and the bracket being connected to the second mounting plate 122 and / or the third mounting plate 123 via a second fastener 182. The second fastener 182 may be a bolt, thereby stabilizing the overall structure. The second fastener 182 is used to fix the second and third mounting plates. During an earthquake, the horizontal seismic force exerted on the shielding rod is transmitted to the second and third mounting plates through the shielding rod, and the second fastener 182 is subjected to a horizontal shear force exerted on it by the second and third mounting plates; in the earthquake condition SL-2, the second fastener 182 is subjected to an upward pulling force exerted on it by the second and third mounting plates in the vertical direction.

[0034] In some embodiments, the inner cylinder 106 may be an inner steel cylinder disposed between the radial outer shield 101 and the radial inner shield 102 , and is used to fix and install the radial outer shield 101 , the radial inner shield 102 and the middle shield 103 .

[0035] The upper end of the inner steel cylinder is substantially flush with the upper end of the middle shield 103, and the lower end is substantially flush with the lower end of the radial outer shield 101. A plurality of through holes for fluid flow are provided on the side wall of the inner steel cylinder that is higher than the radial inner shield 102. The upper end of the outer steel cylinder is substantially flush with the upper end of the upper shield, and the lower end is lower than the upper end of the radial inner shield.

[0036] The first mounting plate 121 can be mounted on the upper edge of the outer steel cylinder. The radial inner side of the second mounting plate 122 is mounted on the upper edge of the inner steel cylinder, and the radial outer side of the second mounting plate 122 is mounted on the middle and lower part of the outer steel cylinder. The radial inner side of the third mounting plate 123 is mounted on the middle part of the inner steel cylinder. The radial inner side of the fourth mounting plate 124 is mounted on the lower end of the inner steel cylinder.

[0037] It can be understood that the above embodiments are described with the inner steel cylinder and the outer steel cylinder as corresponding supporting components, but in other embodiments, each mounting plate may also be supported by the steel cylinder of other internal components of the stack.

[0038] The first mounting plate 121, the second mounting plate 122, the third mounting plate 123 and the fourth mounting plate 124 are provided with mounting holes for mounting the corresponding shielding devices 125. Thus, the shielding devices 125 can be easily mounted and the fixing effect can be ensured.

[0039] In some embodiments, the mounting holes and the corresponding shielding devices 125 form a clearance fit to provide space for thermal expansion. When the internal components of the reactor expand thermally, these shielding rods will not deform incoherently, thereby preventing thermal stress from being generated.

[0040] A filling piece 184 is provided between the mounting hole of the first mounting plate 121 and the corresponding shielding device 125, and the filling piece 184 is connected to the corresponding shielding device 125 through a third fastener 183. Thus, the stability of the overall structure is improved. The filling piece may be a steel ring. During an earthquake, the horizontal earthquake force acts on the filling piece, and the filling piece and the third fastener 183 (which may be a bolt) are deformed together, and are not subjected to force in the horizontal direction during an earthquake; during an earthquake, the third fastener 183 in the vertical direction is deformed together with the shielding rod and is not subjected to force.

[0041] The mounting holes provided in the second mounting plate 122 and / or the third mounting plate 123 are used to simultaneously install two shielding devices 125 arranged in the up-down direction. Thus, the space utilization rate can be effectively improved. One of the two shielding devices 125 is provided with a boss, and the other of the two shielding devices 125 is provided with a groove, and the boss and the groove are clearance-matched, thereby providing space for thermal expansion.

[0042] The following takes the middle shield 103 and the upper shield 104 as examples to briefly explain the installation method of the upper and lower shielding structures. A receiving groove is provided at one end of the steel pipe, and a steel ring fixed with bolts is provided in the receiving groove. A protruding structure is provided at the other end, and a threaded hole is provided on the protruding structure. The receiving groove at the lower end of the upper steel pipe extends downward into the mounting hole, and the protruding structure at the upper end of the lower steel pipe extends into the receiving groove. The upper steel pipe and the lower steel pipe are installed on the same mounting hole through the cooperation of bolts and threads. The mounting plate is used for load bearing, and it is fixed to the inner steel cylinder by a bracket. Specifically, the bracket is welded to the inner steel cylinder, and the mounting plate is fixed by slotted screws. The slotted screws and bolts are reinforced by anti-loosening spot welding. The assembly method of each layer of the shielding structure is similar to this, which will not be repeated here.

[0043] In some embodiments, the shielding assembly 10 may further include a lower shield 105 (composed of a fourth mounting plate 124, a fifth mounting plate disposed below the fourth mounting plate 124, and a shielding device between the fourth mounting plate 124 and the fifth mounting plate) disposed on the radial periphery of the grid header 50 below the radial outer shield 101, which is used to shield neutrons from entering the grid header 50. In the lower shield 105, the number of turns of the shielding member may be 2 to 3 turns.

[0044] A plurality of channels are provided on the lower shield 105 for allowing the pressure tube of the sodium-cooled fast reactor to pass through. In order to facilitate the opening of the channels, the lower shield is not provided with a stainless steel rod or a graphite shielding rod at the position where the channels are provided, but a shielding steel plate is provided. The lower shield 105 can be provided in the lower support body of the in-core support 70. The shield around the core 30 passes through the in-core ionization chamber channel, the sodium level gauge and the thermocouple. The in-core ionization chamber cooling channel, the sodium level gauge channel and the thermocouple channel can be provided on the corresponding shield structure as needed.

[0045] The reactor 1 may further include an in-core support 70, which includes an upper support plate 71 located at the top, a support plate 72 located in the middle, and a support bottom plate 73 located at the bottom. The upper support plate 71 is used to support the drive unit 60 and the intermediate heat exchanger 40; the support plate 72 is arranged in the stack container 20, and is used to support the fourth mounting plate 124 and the core 30, thereby ensuring the overall structural strength and stability; the support bottom plate 73 is used to support the grid header 50. The fourth mounting plate 124 can be mounted on the support plate 72; the fifth mounting plate can be mounted on the support bottom plate 73; the lower end of the radial inner shield 102 can be mounted on the support plate 72; and the lower end of the inner steel cylinder can be mounted on the support plate 72.

[0046] The embodiment of the present application further provides a reactor 1, which includes: a reactor container 20, a core 30, and any of the above-mentioned shielding assemblies 10. The core 30 is disposed in the reactor container 20; the first mounting plate 121 and the second mounting plate 122 of the shielding assembly 10 are installed in the reactor container 20, and the shielding device 125 of the shielding assembly 10 is used to shield neutrons generated by the core 30.

[0047] The shielding assembly 10 provided in the embodiment of the present application can be used as a connection structure for the primary shielding of a fast reactor. The shielding rods of the shielding assembly 10 are safely and reliably fixed in the reactor (a large number of shielding rods in the reactor are constrained and fixed radially and axially, and these constraints are safe and reliable under various working conditions). It can also prevent deformation and incoordination when the components in the reactor expand thermally, thereby generating thermal stress. In some embodiments, the shielding device can have a total of 3 layers (rings), including 2 layers of boron-containing graphite shielding rods and 1 layer of steel shielding rods. These shielding rods are stacked on the support in the reactor through 4 layers of mounting plates, wherein the mounting plates can be grid plates. After force analysis, the bolts and studs connecting the grid plates can maintain the initial connection relationship and structural integrity. In the embodiment of the present application, a bracket can be welded on the outer cylinder and / or the inner cylinder, and the mounting plate is fixed to the bracket by bolts. For a steel cylinder without support around it, the upper and lower mounting plates can be connected by long studs. Mounting holes are opened on the mounting plate, and the shielding rods pass through these mounting holes through matching dimensions. The setting of matching dimensions can facilitate installation. The upper layer of shielding rods can be supported on the lower layer of shielding rods, and the support connection part can be matched with the shaft hole clearance. The upper end of the graphite rod can be threaded with a round nut, and the outer diameter of the nut is matched with the clearance of the mounting hole of the upper mounting plate to radially fix the shielding rod. A matching steel ring can be fixed on the end of the uppermost shielding rod by bolts, and the matching steel ring passes through the mounting hole on the uppermost mounting plate through a clearance fit. The lower end of the graphite rod is placed on the lower support plate in the pile with a clearance fit with the mounting hole of the lower mounting plate. Since the temperature of the inner steel cylinder is lower than that of the outer steel cylinder during normal operation, there is enough gap between the head of the shielding rod and the mounting plate for deformation coordination during thermal expansion. The bolts and studs used to connect the mounting plate can maintain the initial connection relationship under seismic loads to maintain structural integrity.

[0048] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0049] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A shielding assembly (10) of a reactor (1), the reactor (1) comprising a reactor vessel (20) and a reactor core (30) arranged in the reactor vessel (20), the shielding assembly (10) comprising: A first mounting plate (121) mounted in the stack container (20); A second mounting plate (122) is mounted in the reactor container (20), and a portion of a shielding device (125) is accommodated between the first mounting plate (121) and the second mounting plate (122), wherein the shielding device (125) is used to shield neutrons generated by the reactor core (30); a fixing member (126) fixedly connecting the first mounting plate (121) and the second mounting plate (122), The second mounting plate (122) is arranged below the first mounting plate (121); A third mounting plate (123) is installed in the stack container (20) and is located below the second mounting plate (122); a fourth mounting plate (124), mounted in the stack container (20) and located below the third mounting plate (123); Another portion of the shielding device (125) is accommodated between the second mounting plate (122) and the third mounting plate (123) and between the third mounting plate (123) and the fourth mounting plate (124); the first mounting plate (121), the second mounting plate (122), the third mounting plate (123), the fourth mounting plate (124), the portion of the shielding device (125) and the other portion of the shielding device (125) form an accommodation space for accommodating the core (30); The first mounting plate (121), the second mounting plate (122), the third mounting plate (123) and the fourth mounting plate (124) are provided with mounting holes for mounting the corresponding shielding devices (125); The mounting holes provided in the second mounting plate (122) and / or the third mounting plate (123) are used for simultaneously mounting two shielding devices (125) arranged in an up-and-down direction; One of the two shielding devices (125) is provided with a boss, and the other of the two shielding devices (125) is provided with a groove, and the boss is loosely matched with the groove, thereby providing space for thermal expansion.

2. The shielding assembly (10) according to claim 1, wherein: The first mounting plate (121) is formed by splicing a plurality of sub-mounting plates, and the shielding assembly (10) comprises: A connecting member (127) connects the plurality of sub-mounting plates so that the first mounting plate (121) formed by splicing the plurality of sub-mounting plates closes the upper end of the accommodating space.

3. The shielding assembly (10) according to claim 1, wherein: Also includes: The outer cylinder (107) is arranged in the stack container (20), and the outer cylinder (107) is arranged outside the accommodation space. The outer cylinder (107) is connected to the first mounting plate (121) via a first fastener (181).

4. The shielding assembly (10) according to claim 1, wherein: Also includes: The inner cylinder (106) is arranged in the accommodating space, and a bracket is formed on the outer surface of the inner cylinder (106). The bracket is connected to the second mounting plate (122) and / or the third mounting plate (123) via a second fastener (182).

5. The shielding assembly (10) according to claim 1, wherein: The mounting hole forms a clearance fit with the corresponding shielding device (125).

6. The shielding assembly (10) according to claim 1, wherein: A filling piece (184) is provided between the mounting hole opened in the first mounting plate (121) and the corresponding shielding device (125), and the filling piece (184) is connected to the corresponding shielding device (125) via a third fastener (183).

7. The shielding assembly (10) according to claim 1, wherein: Also includes: A support plate (72) is disposed in the stack container (20) and is used to support the fourth mounting plate (124) and the stack core (30).

8. The shielding assembly (10) according to claim 1, wherein: The shielding device (125) shields the neutrons generated by the core (30) by reflecting and / or moderating the neutrons.

9. A reactor (1), comprising: Stack container (20); A core (30) disposed in the stack container (20); The shielding assembly (10) according to any one of claims 1 to 8, wherein the first mounting plate (121) and the second mounting plate (122) of the shielding assembly (10) are installed in the reactor container (20), and the shielding device (125) of the shielding assembly (10) is used to shield neutrons generated by the core (30).

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