Shielding protection device of nuclear power station spent fuel transportation container

Abstract

The utility model relates to a nuclear power station spent fuel transportation container shielding protection device. The device comprises a container body; the neutron shielding layer is arranged on the outer side of the container body in a surrounding mode, a filling cavity is defined by the neutron shielding layer and the outer side wall of the container body, and the filling cavity is filled with neutron shielding materials. By arranging the neutron shielding layer surrounding the outer side of the container body and the neutron shielding material filled in the neutron shielding layer, the neutron radiation shielding problem in the spent fuel transportation and assembly loading process is solved, the neutron radiation dose on the outer surface of the transportation container can be effectively reduced, a stable shielding structure is formed, and safe transportation of spent fuel is guaranteed.

Description

Shielding and protective devices for spent fuel transport containers at nuclear power plants Technical Field

[0001] This application relates to the field of nuclear fuel protection technology, and in particular to a shielding and protection device for a spent fuel transport container of a nuclear power plant. Background Technology

[0002] In the operation of a nuclear power plant, nuclear fuel replacement is a critical and necessary operation. Over time, nuclear fuel becomes spent fuel after being exposed to radiation and must be removed from the reactor. To ensure the continuous and stable operation of the nuclear power plant, spent fuel needs to be loaded into specialized transport containers for transport to long-term storage sites or fuel reprocessing plants.

[0003] However, spent fuel is highly radioactive, posing a serious threat to personnel and the environment during transport. Furthermore, spent fuel continuously generates decay heat. If this heat cannot be dissipated effectively and promptly, the internal temperature of the transport container will continue to rise. On the one hand, high temperatures may degrade the performance of the container's structural materials, reducing its safety and stability and increasing the risk of accidents during transport; on the other hand, excessively high temperatures can also pose safety hazards such as burns to operators.

[0004] Existing spent fuel transport containers have inadequate shielding, failing to fully meet increasingly stringent radiation protection standards. Their heat transfer systems are inefficient, unable to quickly and effectively dissipate decay heat, leading to unstable container temperature control. Furthermore, the loading process for spent fuel assemblies is complex, requiring close-range manual operation in some steps. This not only increases the risk of radiation exposure for operators but also increases the risk of burns due to high temperatures, posing a significant threat to their safety. Summary of the Invention

[0005] Based on this, a shielding and protection device for spent fuel transport containers in nuclear power plants is provided to solve the problem that the shielding effect of existing spent fuel transport containers is not ideal.

[0006] This application provides a shielding and protection device for a spent fuel transport container of a nuclear power plant, comprising: a container body; a neutron shielding layer disposed around the outside of the container body, wherein the neutron shielding layer and the outer wall of the container body form a filling cavity, and the filling cavity is filled with neutron shielding material.

[0007] According to one embodiment of this application, the neutron shielding layer includes an outer shell, a first end plate, a second end plate, and a plurality of heat sinks; the outer shell is sleeved on the outside of the container body, the first end plate connects one end of the outer shell to the side wall of the container body, the second end plate connects the other end of the outer shell to the side wall of the container body, and the outer shell, the first end plate, the second end plate, and the side wall of the container body form the filling cavity; the plurality of heat sinks are located in the filling cavity and connect the outer shell and the container body; wherein, the filling cavity includes a plurality of sub-cavities separated by the plurality of heat sinks, and the plurality of sub-cavities are respectively filled with the neutron shielding material.

[0008] According to one embodiment of this application, the neutron shielding layer includes a plurality of heat dissipation tubes arranged circumferentially along the container body, with adjacent heat dissipation tubes fixedly connected. Each heat dissipation tube includes a first side plate, a second side plate, a third side plate, and a fourth side plate. The first side plate and the third side plate are disposed opposite to each other and are fixedly connected to the container body. The second side plate and the fourth side plate are disposed opposite to each other and are both fixedly connected to the first side plate and the third side plate. The third side plates of the plurality of heat dissipation tubes are spliced ​​to form the outer shell. The second side plate and the fourth side plate of the heat dissipation tube constitute the heat sink. The inner cavity of the heat dissipation tube constitutes the sub-chamber. Alternatively, the outer shell includes a sleeve fitted onto the outside of the container body. One side of the heat sink is fixedly connected to the inner wall of the sleeve, and the other side is fixedly connected to the outer wall of the container body.

[0009] According to one embodiment of this application, the heat sink extends along the axial direction of the container body, and the angle between the sectional surface of the container body at the connection position with the heat sink and the plane where the heat sink is located is greater than 0° and less than 90°.

[0010] According to one embodiment of this application, the first end plate and / or the second end plate are provided with a pressure relief valve.

[0011] According to one embodiment of this application, the container body includes a first cylinder, a second cylinder, a third cylinder, a first end cap, a second end cap, a support ring, and a lifting trunnion. The first cylinder, the second cylinder, and the third cylinder are connected in sequence. The second cylinder is located inside the neutron shielding layer and is fixedly connected to the neutron shielding layer. The first end cap is detachably embedded in one end of the first cylinder away from the second cylinder. The second end cap is connected to the third cylinder. The support ring is fixedly disposed on the outside of the first cylinder. The lifting trunnion is fixedly connected to the support ring.

[0012] According to one embodiment of this application, the first cylinder is provided with a first stepped surface and a second stepped surface, and the first end cover includes: an inner cover, the first end of which is provided with a third stepped surface that overlaps with the first stepped surface and a first sealing ring located on the third stepped surface; and a clamping cover, which is bolted to the first cylinder, the clamping cover being provided with a fourth stepped surface that overlaps with the second stepped surface and a second sealing ring located on the fourth stepped surface.

[0013] According to one embodiment of this application, the first cylinder is provided with at least one positioning groove, and the inner cover is provided with at least one positioning protrusion on its periphery, the positioning protrusion being located within the positioning groove.

[0014] According to one embodiment of this application, the second end of the inner cover is provided with an external connection hole, and the first end cover further includes: a connector, installed on the inner cover, one end of the connector being located in the external connection hole, and the other end extending to the first end of the inner cover; a first hole cover, located at the opening position of the external connection hole, and detachably connected to the inner cover; and a pressing cover is provided with a through hole, the through hole being opposite to the first hole cover.

[0015] According to one embodiment of this application, multiple second sealing rings are concentrically arranged; the pressing cover is provided with a detection hole, one end of the detection hole extends to one end of the pressing cover away from the fourth stepped surface, the other end of the detection hole extends to the fourth stepped surface, and is located between two adjacent second sealing rings.

[0016] According to one embodiment of this application, the third cylinder is provided with an inflation and drainage hole and a sealing structure for sealing the inflation and drainage hole; the inflation and drainage hole includes a first section, a second section, and a third section, the diameters of the first section, the second section, and the third section increasing sequentially and connected sequentially, the first section connecting to the inner cavity of the container body, and the third section extending to the outer wall of the third cylinder; the sealing structure includes a rotary plug, a lead plug, and a second hole cover, the rotary plug being located in the first section and threadedly connected to the third cylinder, the lead plug being located in the second section, and the second hole cover being located in the third section and detachably connected to the third cylinder.

[0017] According to one embodiment of this application, at least one anti-rotation part is provided on the outer side of the neutron shielding layer, and the anti-rotation part is provided with a positioning groove for cooperating with an external positioning structure.

[0018] According to one embodiment of this application, the neutron shielding layer is provided with a pipe connection structure suitable for external cooling pipes, and the filling cavity is reused for filling coolant.

[0019] The aforementioned shielding and protection device for spent fuel transport containers in nuclear power plants solves the problem of neutron radiation shielding during spent fuel transport and component loading by setting up a neutron shielding layer around the outside of the container body and filling it with neutron shielding material. It can effectively reduce the neutron radiation dose on the outer surface of the transport container and form a stable shielding structure, thus providing a guarantee for the safe transport of spent fuel. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the overall structure of a shielding and protection device for a nuclear power plant spent fuel transport container provided in an embodiment of this application.

[0021] Figure 2 is a schematic diagram of the neutron shielding layer installation structure in a shielding and protection device for spent fuel transport containers in a nuclear power plant provided in an embodiment of this application.

[0022] Figure 3 is a schematic diagram of a partial structure of the neutron shielding layer in a shielding and protection device for a spent fuel transport container of a nuclear power plant provided in an embodiment of this application.

[0023] Figure 4 is a schematic diagram of the heat dissipation pipe structure in the shielding and protection device for spent fuel transport containers in nuclear power plants provided in an embodiment of this application.

[0024] Figure 5 is a schematic diagram of a partial structure of the neutron shielding layer in a shielding and protection device for a spent fuel transport container of a nuclear power plant provided in another embodiment of this application.

[0025] Figure 6 is a schematic diagram of a pressure relief valve in a shielding and protection device for a spent fuel transport container in a nuclear power plant, provided in an embodiment of this application.

[0026] Figure 7 is a schematic diagram of the inner cover structure in the shielding and protection device for the spent fuel transport container of a nuclear power plant provided in an embodiment of this application.

[0027] Figure 8 is a partial cross-sectional view of the inner cover of a shielding and protective device for a spent fuel transport container in a nuclear power plant, according to an embodiment of this application.

[0028] Figure 9 is a schematic diagram of the clamping cover installation structure in a shielding and protection device for a spent fuel transport container in a nuclear power plant according to an embodiment of this application.

[0029] Figure 10 is a partial cross-sectional view of the compression cover in a shielding and protective device for a spent fuel transport container in a nuclear power plant according to an embodiment of this application.

[0030] Figure 11 is a schematic diagram of the bottom structure of a shielding and protection device for a spent fuel transport container in a nuclear power plant, provided in an embodiment of this application.

[0031] Figure 12 is a schematic diagram of the air-filling and drainage holes and the sealing structure in a shielding and protection device for a spent fuel transport container of a nuclear power plant provided in an embodiment of this application.

[0032] Figure label:

[0033] 100. Container body; 110. First cylinder; 111. Positioning groove; 120. Second cylinder; 130. Third cylinder; 131. Inflation / drainage hole; 132. Rotary screw plug; 133. Lead plug; 134. Second hole cover; 140. First end cover; 141. Inner cover; 1411. First sealing ring; 1412. External connection hole; 1413. Positioning protrusion; 142. Connector; 143. First hole cover; 144. Pressing cover; 1441. Inspection hole; 1442. Through hole; 1443. Second sealing ring; 150. Second end cover; 160. Support ring; 170. Lifting trunnion;

[0034] 200, Neutron shielding layer; 210, Outer shell; 220, First end plate; 221, Pressure relief valve; 230, Second end plate; 240, Heat sink; 250, Heat dissipation pipe; 251, First side plate; 252, Second side plate; 253, Third side plate; 254, Fourth side plate; 260, Anti-rotation part; 261, Positioning groove; 270, Filling cavity. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0036] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0037] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0041] Referring to Figures 1 and 2, an embodiment of this application provides a shielding and protection device for a spent fuel transport container in a nuclear power plant, comprising a container body 100 and a neutron shielding layer 200. The neutron shielding layer 200 is arranged around the outside of the container body 100, and the neutron shielding layer 200 and the outer wall of the container body 100 form a filling cavity 270, which is filled with neutron shielding material.

[0042] In the shielding and protection device for spent fuel transport containers of nuclear power plants in this embodiment, the container body 100 is used to load spent fuel and provide a space for it. A neutron shielding layer 200 is arranged around the outside of the container body 100, forming a filling cavity 270 with the outer wall of the container body 100. The neutron shielding material filled in the filling cavity 270 effectively blocks and weakens neutron radiation emitted from the spent fuel inside the container body 100 through its neutron absorption characteristics. Its mechanism is such that when neutrons generated by the spent fuel radiate outwards from the container, the neutrons are continuously absorbed and attenuated by the shielding material as they pass through the filling cavity 270, thereby significantly reducing the neutron radiation dose on the outer surface of the shielding and protection device for spent fuel transport containers of nuclear power plants, ensuring the safety of personnel and the environment during transport.

[0043] The neutron shielding material in this embodiment can be boron-containing, hydrogen-containing, or heavy metal materials, such as silicon-based shielding materials mixed with boron; no specific limitation is made here. Furthermore, the container body 100 and the neutron shielding layer 200 can be made of metals, such as stainless steel, which has good structural strength, corrosion resistance, and high-temperature resistance, and can block and reduce neutron radiation emitted from spent fuel inside the container body 100.

[0044] In some embodiments, the neutron shielding layer 200 is provided with a pipe connection structure suitable for external cooling pipes, and the filling cavity 270 is reused for filling coolant. For example, the neutron shielding layer 200 is provided with a threaded pipe connection port, which is connected to a cooling pipe with a matching thread, and a rubber sealing gasket is added at the connection to prevent leakage. A water pump is installed on the cooling pipe for driving. Water or a special coolant is selected as the coolant, and the coolant is circulated and dissipated by the water pump. Pressure and temperature sensors are installed on the cooling pipe or the neutron shielding layer 200 for monitoring. The operation of the water pump is controlled based on the pressure and temperature detection results. When overheating is detected, water is circulated through the cooling pipe to remove heat from the outer surface of the spent fuel transport container shielding device of the nuclear power plant, thereby preventing the spent fuel transport container shielding device of the nuclear power plant from overheating.

[0045] The flow of coolant in the filling cavity 270 can be achieved by providing a pipe or gap for coolant to flow through in the filling cavity 270, or by allowing the coolant to pass through the neutron shielding material, etc., without specific limitations here.

[0046] In the above embodiments, the neutron shielding layer 200 simultaneously meets the requirements of radiation shielding and cooling, which can further improve the safety during transportation and ensure the safety of personnel and the environment during transportation.

[0047] Referring to Figure 2, in some embodiments, the neutron shielding layer 200 includes an outer shell 210, a first end plate 220, a second end plate 230, and a plurality of heat sinks 240.

[0048] Specifically, the container body 100 is an approximately cylindrical container. An outer shell 210 is fitted over the outside of the container body 100. The first end plate 220 and the second end plate 230 are annular plates fitted over the outside of the container body 100. The outer side of the first end plate 220 is connected to one end of the outer shell 210, and the inner side of the first end plate 220 is connected to the side wall of the container body 100. The outer side of the second end plate 230 is connected to the other end of the outer shell 210, and the inner side of the second end plate 230 is connected to the side wall of the container body 100. The outer shell 210, the first end plate 220, the second end plate 230, and the side wall of the container body 100 together form a filling cavity 270. Multiple heat sinks 240 are located within the filling cavity 270. One side of each heat sink 240 is connected to the outer shell 210, and the other side is connected to the container body 100. The filling cavity 270 includes multiple sub-chambers separated by the multiple heat sinks 240, and each sub-chamber is filled with neutron shielding material.

[0049] In this embodiment, the heat sink 240 connects the outer shell 210 and the container body 100, enabling it to promptly transfer the decay heat generated by spent fuel inside the container body 100 to the outer shell 210. The outer shell 210 then dissipates heat to the outside, ensuring that the internal and external surface temperatures of the transport container remain within a reasonable and controllable range, thus preventing transport accidents caused by high temperatures. Furthermore, the interconnected components form a stable overall structure that not only securely houses and protects the neutron shielding material but also withstands certain external forces during transport, ensuring the safety and reliability of the transport container.

[0050] Referring to Figures 3 and 4, as an optional configuration, the neutron shielding layer 200 includes multiple heat dissipation pipes 250 arranged circumferentially along the container body 100. Adjacent heat dissipation pipes 250 are fixedly connected. Each heat dissipation pipe 250 includes a first side plate 251, a second side plate 252, a third side plate 253, and a fourth side plate 254. The first side plate 251 and the third side plate 253 are positioned opposite each other and are fixedly connected to the container body 100. The second side plate 252 and the fourth side plate 254 are positioned opposite each other and are both fixedly connected to the first side plate 251 and the third side plate 253. The third side plates 253 of the multiple heat dissipation pipes 250 are spliced ​​together to form an outer shell 210. The second side plates 252 and the fourth side plates 254 of the heat dissipation pipes 250 constitute heat sinks 240, and the inner cavity of the heat dissipation pipes 250 constitutes a sub-chamber.

[0051] For example, the first side plate 251 and the third side plate 253 of the heat dissipation pipe 250 are arc-shaped plates, which allows the heat dissipation pipe 250 to fit and be fixed better with the container body 100, and allows multiple third side plates 253 to be assembled to form a continuous outer shell 210 structure.

[0052] Of course, the heat dissipation pipe 250 may not have the first side plate 251. Instead, the side wall of the container body 100 can be used as the side wall of the heat dissipation pipe 250, which can also achieve the function of forming multiple sub-chambers.

[0053] The neutron shielding layer 200 is formed by combining heat dissipation pipes 250. While realizing the function of the neutron shielding layer 200, it can be modularized, effectively reducing the difficulty of production, and is conducive to improving the structural strength, shielding effect and heat conduction capacity of the shielding and protection device for spent fuel transport containers in nuclear power plants.

[0054] Referring to Figure 5, as an alternative embodiment, the outer casing 210 includes a sleeve fitted over the outer side of the container body 100. One side of the heat sink 240 is fixedly connected to the inner wall of the sleeve, and the other side is fixedly connected to the outer wall of the container body 100. The sleeve and the container body 100 are supported by the heat sink 240 to maintain their relative position, forming a filling cavity 270 between them. The heat sink 240 also increases heat conduction between the container body 100 and the sleeve and divides the filling cavity 270 into multiple sub-chambers.

[0055] In some embodiments, the heat sink 240 extends along the axial direction of the container body 100, and the included angle α between the sectional surface A of the container body 100 at the connection position with the heat sink 240 and the plane containing the heat sink 240 is greater than 0° and less than 90°. For example, the included angle α between the sectional surface A of the container body 100 at the connection position with the heat sink 240 and the plane containing the heat sink 240 is 30°, 45°, or 60°.

[0056] In this embodiment, the heat sink 240 extends along the axial direction of the container body 100 and is inclined. On the one hand, this makes the extension direction of the sub-chamber parallel to the axial direction of the container body 100, making it easier for the neutron shielding material to fill the sub-chamber and form a more comprehensive protection for the periphery of the container body 100. On the other hand, the heat sink 240 itself can also play a shielding role, which can further improve the protection effect.

[0057] Referring to Figure 6, in some embodiments, at least one of the first end plate 220 and the second end plate 230 is provided with a pressure relief valve 221. By providing a pressure relief valve 221 in at least one of the first end plate 220 and the second end plate 230, the pressure generated by the thermal expansion of the neutron shielding material can be released in a timely manner, effectively preventing damage to the shielding protection device structure of the spent fuel transport container of the nuclear power plant due to excessive pressure, ensuring the stability of the container structure, ensuring the normal functioning of the shielding protection function during transportation, reducing transportation risks, and improving the safety of spent fuel transportation.

[0058] Referring to Figure 2, in some embodiments, the container body 100 includes a first cylinder 110, a second cylinder 120, a third cylinder 130, a first end cap 140, a second end cap 150, a support ring 160, and a lifting trunnion 170.

[0059] The first cylindrical body 110, the second cylindrical body 120, and the third cylindrical body 130 are coaxially arranged and connected sequentially along the axial direction. The second cylindrical body 120 is located inside the neutron shielding layer 200 and is fixedly connected to the neutron shielding layer 200. At least a portion of the second cylindrical body 120 and at least a portion of the third cylindrical body 130 extend outside the neutron shielding layer 200. The first cylindrical body 110, the second cylindrical body 120, and the third cylindrical body 130 are formed separately and fixed by welding, or the first cylindrical body 110, the second cylindrical body 120, and the third cylindrical body 130 are formed integrally.

[0060] The first end cap 140 is detachably embedded in the end of the first cylinder 110 away from the second cylinder 120. The second end cap 150 is connected to the third cylinder 130. The first end cap 140 and the second end cap 150 can seal both ends of the cylinder structure formed by the first cylinder 110, the second cylinder 120 and the third cylinder 130 to prevent leakage, and can work together with the first cylinder 110 and the second cylinder 120 to provide shielding protection.

[0061] A support ring 160 is fixedly disposed on the outer side of the first cylinder 110. An installation groove is provided on the outer side of the support ring 160. One end of the lifting trunnion 170 is located within the installation groove and is fixedly connected to the support ring 160 by means such as welding. Optionally, multiple lifting trunnions 170 are provided, arranged at equal angles around the circumference of the support ring 160. For example, two lifting trunnions 170 are provided, positioned on opposite sides of the support ring 160. The support ring 160 and lifting trunnions 170 facilitate the hoisting and transportation of the shielding and protective device for spent fuel transport containers in nuclear power plants, effectively reducing the difficulty of loading operations, decreasing the workload of personnel, and thus reducing radiation and high-temperature burn risks.

[0062] Referring to Figures 2 and 7, in some embodiments, the first cylindrical body 110 is provided with a first stepped surface and a second stepped surface. Both the first and second stepped surfaces are annular surfaces, with the first stepped surface located at one end of the second stepped surface near the center of the first cylindrical body 110, and the positioning groove 111 located on the inner wall of the first cylindrical body 110.

[0063] The first end cap 140 includes an inner cap 141, which has a disc structure. The first end of the inner cap 141 has a third stepped surface that overlaps with the first stepped surface, and a first sealing ring 1411 located on the third stepped surface. The third stepped surface is an annular surface. When the first end cap 140 is embedded in the open end of the first cylinder 110, the third stepped surface overlaps with the first stepped surface, and the first sealing ring 1411 contacts and engages with the first stepped surface. Two or more first sealing rings 1411 can be provided as needed to further enhance the sealing effect.

[0064] Referring to Figures 7 and 8, in some embodiments, the first cylindrical body 110 is provided with at least one positioning groove 111, and the inner cover 141 is provided with at least one positioning protrusion 1413 on its circumferential side. The positioning protrusion 1413 extends axially along the inner cover 141 and is located within the positioning groove 111. Through the cooperation between the positioning protrusion 1413 and the positioning groove 111, circumferential rotation limitation between the inner cover 141 and the first cylindrical body 110 can be achieved, preventing relative rotation between the inner cover 141 and the first cylindrical body 110, and making the inner cover 141 easy to install.

[0065] Optionally, the inner cover 141 is provided with a plurality of positioning protrusions 1413, which are arranged sequentially along the circumference of the inner cover 141. The inner wall of the first cylinder 110 is provided with a plurality of positioning grooves 111, and the plurality of positioning protrusions 1413 are respectively matched with a positioning groove 111.

[0066] In some embodiments, the second end of the inner cover 141 is provided with an external connection hole 1412, and the external connection hole 1412 forms an open structure on the end face of the second end of the inner cover 141. The first end cover 140 also includes a connector 142 and a first hole cover 143.

[0067] The connector 142 is installed on the inner cover 141. One end of the connector 142 is located in the outer hole 1412, and the other end extends to the first end of the inner cover 141. The connector 142 can be a quick connector 142, which can be connected to the outside pipeline, so that the gas filling and drainage operations of the shielding protection device of the spent fuel transport container of the nuclear power plant can be performed through the connector 142.

[0068] The first cover 143 is located at the opening of the external connection hole 1412 and is detachably connected to the inner cover 141. The opening of the external connection hole 1412 can be opened and closed through the first cover 143. Thus, the external connection hole 1412 can be opened to connect the pipe to the connector 142 when it is necessary to perform gas filling and drainage operations on the shielding and protective device of the spent fuel transport container of the nuclear power plant. When it is not necessary to perform gas filling and drainage operations, the external connection hole 1412 can be closed to prevent leakage of internal materials of the shielding and protective device of the spent fuel transport container of the nuclear power plant or external debris from entering the external connection hole 1412 or the connector 142.

[0069] Optionally, the opening position of the external hole 1412 is provided with a fifth stepped surface, the first end cap 140 is embedded in the opening position of the external hole 1412, abuts against the fifth stepped surface, and is detachably and fixedly connected to the inner cover 141 by a threaded component (such as a bolt or screw).

[0070] Referring to Figures 9 and 10, optionally, the first end cap 140 further includes a clamping cap 144, which is embedded in the open end of the first cylindrical body 110 and located on the side of the inner cap 141 opposite to the center of the first cylindrical body 110. The clamping cap 144 is bolted to the first cylindrical body 110. The clamping cap 144 can limit the inner cap 141, ensuring that the inner cap 141 is stably installed at the end of the first cylindrical body 110.

[0071] For example, the compression cap 144 is provided with a fourth stepped surface that overlaps with the second stepped surface and at least two second sealing rings 1443. The at least two second sealing rings 1443 are concentrically arranged on the fourth stepped surface. When the fourth stepped surface overlaps with the second stepped surface, the two second sealing rings 1443 respectively contact the second stepped surface to increase the sealing between the compression cap 144 and the first cylinder 110.

[0072] To ensure the structural strength and shielding effect of the first end cover 140, a thicker size is required, which makes the operation more difficult when opening and closing the shielding protection device of the spent fuel transport container of the nuclear power plant. In this embodiment, the first end cover 140 can be adopted as a separate form of the clamping cover 144 and the inner cover 141, thereby reducing the difficulty of hoisting the first end cover 140 and making the shielding protection device of the spent fuel transport container of the nuclear power plant more convenient to use.

[0073] Of course, in some other embodiments, the clamping cap 144 and the inner cap 141 can also be integrally formed, which can also meet the usage requirements of the first end cap 140.

[0074] Optionally, the compression cap 144 is provided with a detection hole 1441. One end of the detection hole 1441 extends to the end of the compression cap 144 away from the fourth stepped surface, and the other end of the detection hole 1441 extends to the fourth stepped surface and is located between two adjacent second sealing rings 1443. The detection hole 1441 can be used for leakage testing of the second sealing rings 1443.

[0075] Optionally, the clamping cover 144 is provided with a through hole 1442, which is opposite to the first cover 143. For example, the area of ​​the through hole 1442 is greater than or equal to the area of ​​the first cover 143, and the through hole 1442 is opposite to the first cover 143 along the axial direction of the clamping cover 144. The through hole 1442 allows the first cover 143 to be opened and closed without removing the clamping cover 144, making the shielding protection device for spent fuel transport containers in nuclear power plants more convenient to use.

[0076] Referring to Figures 11 and 12, in some embodiments, the third cylinder 130 is provided with an inflation / drainage hole 131 and a sealing structure for sealing the inflation / drainage hole 131. The inflation / drainage hole 131 includes a first section, a second section, and a third section, with the diameters of the first, second, and third sections increasing sequentially and connected sequentially. The first section connects to the inner cavity of the container body 100, and the third section extends to the outer wall of the third cylinder 130. The sealing structure includes a rotary plug 132, a lead plug 133, and a second hole cover 134. The rotary plug 132 is located within the first section and is threadedly connected to the third cylinder 130. The lead plug 133 is located within the second section, and the second hole cover 134 is located within the third section and is detachably connected to the third cylinder 130.

[0077] For example, the outer surface of the rotary plug 132 is threaded, which matches the inner wall thread of the first bore section of the third cylinder 130. Through this threaded connection, the rotary plug 132 is tightly fixed to the third cylinder 130. During installation, aligning the rotary plug 132 with the first bore section and rotating it in the direction of the thread allows it to gradually screw into the bore until a suitable tightness is achieved. For disassembly, simply rotating it in the opposite direction allows for easy removal. This threaded connection method is simple to operate and ensures connection stability and sealing. To prevent leakage from the inflation / drainage hole 131, the rotary plug 132 has a sealing structure at the contact point with the first bore section. For example, an annular groove is provided on the outer periphery of the rotary plug 132, near the front or rear end, and a rubber sealing ring is placed within the groove. When the rotary plug 132 is tightened, the rubber sealing ring is compressed and undergoes elastic deformation, filling the tiny gap between the rotary plug 132 and the bore wall, thereby effectively preventing gas or liquid leakage and ensuring the container's sealing.

[0078] For example, the lead plug 133 is columnar or adapted to the shape of the second orifice. The size of the lead plug 133 matches the second orifice and can tightly fill the second orifice. The lead plug 133 is made of high-purity lead and utilizes the strong attenuation properties of lead to effectively block neutrons and gamma rays, reducing the risk of radiation leakage.

[0079] Optionally, the lead plug 133 has a smooth surface to ensure a tight fit with the bore wall and reduce the possibility of leakage. During installation, the lead plug 133 can be directly inserted into the second bore section, achieving a sealing and shielding function through its own weight and the plasticity of lead, and is easy to disassemble and replace.

[0080] For example, the end of the third hole section is provided with a threaded hole, and the second hole cover 134 is provided with a through hole 1442. The second hole cover 134 is detachably installed on the third cylinder 130 by a bolt that passes through the through hole 1442 and is threadedly engaged with the threaded hole.

[0081] In this embodiment, the inflation / drainage hole 131 provides an inflation / drainage channel for the shielding and protection device of the spent fuel transport container in a nuclear power plant. This hole allows accumulated water to drain, preventing corrosion of the container or impact on the stability of its internal structure. The cooperation of the rotating plug 132 and the second hole cover 134 makes the sealing operation of the inflation / drainage hole 131 convenient and reliable. The threaded connection of the rotating plug 132 facilitates installation and disassembly. The lead plug 133, as part of the sealing structure, utilizes the radiation shielding properties of lead to enhance the shielding effect against radiation from the spent fuel inside the container, reducing the risk of radiation leakage. The detachable connection of the second hole cover 134 allows for quick opening or closing of the passage when needed, ensuring the safety and functionality of the container in different usage scenarios.

[0082] In some embodiments, at least one anti-rotation portion 260 is provided on the outer side of the neutron shielding layer 200, and the anti-rotation portion 260 is provided with a positioning groove 261 for cooperating with an external positioning structure.

[0083] For example, the anti-rotation portion 260 extends axially along the neutron shielding layer 200, and the positioning groove 261 is provided on the side of the anti-rotation portion 260 opposite to the neutron shielding layer 200, and the positioning groove 261 extends axially along the neutron shielding layer 200. Multiple anti-rotation portions 260 are provided circumferentially along the neutron shielding layer 200; for example, two anti-rotation portions 260 are provided, and the two anti-rotation portions 260 are symmetrical about a plane passing through the axis of the neutron shielding layer 200.

[0084] By incorporating the anti-rotation section 260, the shielding and protective device for the spent fuel transport container of the nuclear power plant can be transported more easily, increasing its stability during transport. Specifically, when transporting the shielding and protective device, the device is placed horizontally, i.e., its axis is horizontal. At this time, the anti-rotation section 260 is located on both sides of the shielding and protective device, and the external positioning structure cooperates with the positioning groove 261 to prevent axial rotation of the shielding and protective device.

[0085] For example, the external positioning structure is a positioning pin that matches the positioning groove 261 and is installed on the transport equipment or fixed bracket. When the shielding device of the spent fuel transport container of the nuclear power plant is placed horizontally, the positioning pin is inserted into the positioning groove 261 to prevent the container from rotating axially. The diameter and length of the positioning pin should be determined according to the size of the positioning groove 261 to ensure a tight fit. This positioning method is simple in structure, accurate in positioning, and can effectively limit the rotation of the container. Alternatively, the external positioning structure is a clamp for fixing the shielding device of the spent fuel transport container of the nuclear power plant. The clamp has clamping components corresponding to the anti-rotation part 260, which achieve the anti-rotation function by clamping the positioning groove 261. The clamp can be a mechanical clamp, which clamps with bolts, nuts, or other fastening devices; or it can be a hydraulic or pneumatic clamp, which uses hydraulic or pneumatic power to achieve rapid clamping and loosening. The clamp device can provide a strong clamping force to ensure the stability of the container during transportation.

[0086] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0087] The embodiments described above are merely illustrative of several implementation methods of this application, and 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 those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A shielding and protective device for a spent fuel transport container in a nuclear power plant, characterized in that, include: The container body; a neutron shielding layer is arranged around the outside of the container body, the neutron shielding layer and the outer wall of the container body form a filling cavity, and the filling cavity is filled with neutron shielding material.

2. The shielding and protection device for spent nuclear fuel transport containers according to claim 1, characterized in that, The neutron shielding layer includes an outer shell, a first end plate, a second end plate, and multiple heat sinks. The outer shell is fitted onto the outside of the container body. The first end plate connects one end of the outer shell to the side wall of the container body, and the second end plate connects the other end of the outer shell to the side wall of the container body. The outer shell, the first end plate, and the second end plate, together with the side wall of the container body, form the filling cavity. The heat sinks are located within the filling cavity and connect the outer shell and the container body. The filling cavity includes multiple sub-cavities separated by the multiple heat sinks, and each of the multiple sub-cavities is filled with the neutron shielding material.

3. The shielding and protection device for spent nuclear fuel transport containers according to claim 2, characterized in that, The neutron shielding layer includes multiple heat dissipation tubes arranged circumferentially along the container body. Adjacent heat dissipation tubes are fixedly connected. Each heat dissipation tube includes a first side plate, a second side plate, a third side plate, and a fourth side plate. The first side plate and the third side plate are opposite to each other and are fixedly connected to the container body. The second side plate and the fourth side plate are opposite to each other and are both fixedly connected to the first side plate and the third side plate. The third side plates of the multiple heat dissipation tubes are spliced ​​to form the outer shell. The second side plate and the fourth side plate of the heat dissipation tubes constitute the heat sink. The inner cavity of the heat dissipation tubes constitutes the sub-chamber. Alternatively, the outer shell includes a sleeve fitted onto the outside of the container body. One side of the heat sink is fixedly connected to the inner wall of the sleeve, and the other side is fixedly connected to the outer wall of the container body.

4. The shielding and protection device for spent fuel transport containers in nuclear power plants according to claim 2 or 3, characterized in that, The heat sink extends along the axial direction of the container body, and the angle between the sectional surface of the container body at the connection position with the heat sink and the plane where the heat sink is located is greater than 0° and less than 90°.

5. The shielding and protection device for spent nuclear fuel transport containers according to claim 2 or 3, characterized in that, The first end plate and / or the second end plate are provided with pressure relief valves.

6. The shielding and protection device for spent nuclear fuel transport containers according to claim 1, characterized in that, The container body includes a first cylinder, a second cylinder, a third cylinder, a first end cap, a second end cap, a support ring, and a lifting trunnion. The first cylinder, the second cylinder, and the third cylinder are connected in sequence. The second cylinder is located inside the neutron shielding layer and is fixedly connected to the neutron shielding layer. The first end cap is detachably embedded in the end of the first cylinder opposite to the second cylinder. The second end cap is connected to the third cylinder. The support ring is fixedly disposed on the outside of the first cylinder. The lifting trunnion is fixedly connected to the support ring.

7. The shielding and protection device for spent fuel transport containers in nuclear power plants according to claim 6, characterized in that, The first cylinder is provided with a first stepped surface and a second stepped surface. The first end cap includes: an inner cap, the first end of which is provided with a third stepped surface that overlaps with the first stepped surface and a first sealing ring located on the third stepped surface; and a clamping cap, which is bolted to the first cylinder, the clamping cap being provided with a fourth stepped surface that overlaps with the second stepped surface and a second sealing ring located on the fourth stepped surface.

8. The shielding and protection device for spent fuel transport containers in nuclear power plants according to claim 7, characterized in that, The first cylinder is provided with at least one positioning groove, and the inner cover is provided with at least one positioning protrusion on its periphery, the positioning protrusion being located within the positioning groove.

9. The shielding and protection device for spent fuel transport containers in nuclear power plants according to claim 7 or 8, characterized in that, The second end of the inner cover is provided with an external connection hole. The first end cover further includes: a connector, which is installed on the inner cover, with one end of the connector located in the external connection hole and the other end extending to the first end of the inner cover; a first hole cover, which is located at the opening of the external connection hole and is detachably connected to the inner cover; and a pressing cover is provided with a through hole, which is opposite to the first hole cover.

10. The shielding and protection device for spent fuel transport containers in nuclear power plants according to claim 7 or 8, characterized in that, Multiple second sealing rings are concentrically arranged; the pressing cover is provided with a detection hole, one end of which extends to the end of the pressing cover away from the fourth stepped surface, and the other end of which extends to the fourth stepped surface and is located between two adjacent second sealing rings.

11. The shielding and protection device for spent fuel transport containers in nuclear power plants according to claim 6 or 7, characterized in that, The third cylinder is provided with an inflation and drainage hole and a sealing structure for sealing the inflation and drainage hole; the inflation and drainage hole includes a first section, a second section, and a third section, the diameters of the first section, the second section, and the third section increasing sequentially and connected sequentially, the first section connecting to the inner cavity of the container body, and the third section extending to the outer wall of the third cylinder; the sealing structure includes a rotating screw plug, a lead plug, and a second hole cover, the rotating screw plug being located in the first section and threadedly connected to the third cylinder, the lead plug being located in the second section, and the second hole cover being located in the third section and detachably connected to the third cylinder.

12. The shielding and protection device for spent fuel transport containers in nuclear power plants according to any one of claims 1 to 3, characterized in that, At least one anti-rotation part is provided on the outer side of the neutron shielding layer, and the anti-rotation part is provided with a positioning groove for cooperating with an external positioning structure.

13. The shielding and protection device for spent fuel transport containers in nuclear power plants according to any one of claims 1 to 3, characterized in that, The neutron shielding layer is provided with a pipe connection structure suitable for external cooling pipes, and the filling cavity is reused for filling coolant.

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