Outer containment shell of new fuel assembly transport container and new fuel assembly transport container

Abstract

A novel fuel assembly transport container is provided, consisting of an outer shell and the transport container itself. The outer shell includes an outer body, energy-absorbing components, and fasteners. The energy-absorbing components include a support ring, a support frame, an energy-absorbing ring, and an energy-absorbing shroud. The support ring is fitted onto the outer body, the support frame has a U-shaped structure, and all joints between the support ring, the support frame, and the outer body are fixedly connected. The energy-absorbing ring is a hollow conical annular cavity structure fitted onto the outer body. The energy-absorbing shroud is a conical hollow shroud structure located on the outer sides of both ends of the outer body. Thus, in the event of a transport incident / accident of the same or equivalent level as the mechanical test listed in GB11806 during transport, the deformation of the energy-absorbing components can mitigate the axial and radial impacts on the outer shell, ensuring its structural integrity and sealing. This effectively reduces the energy consumption of the new fuel assembly, mitigating its damage and preventing the release of radioactive materials into the external environment.

Description

Technical Field

[0001] This application relates to the field of transportation, and more specifically to an outer shell and a new fuel assembly transport container. Background Technology

[0002] A new fuel assembly transport container is a container specifically designed for transporting nuclear fuel assemblies (new fuel assemblies) that have just been produced from a nuclear fuel plant, ensuring their critical safety. According to the Chinese national standard GB11806-2019, in the event of a transport event / accident of the same or equivalent level as a mechanical performance verification test, the new fuel assembly transport container must prevent the release of radioactive materials due to impact, thus preventing nuclear events / accidents. Therefore, the design of the pressure-bearing and sealing structure of the outer shell is essential and crucial to ensure that the new fuel assembly transport container can withstand mechanical transport events / accidents such as a 9m drop / dynamic crushing and a 1m puncture.

[0003] However, there is currently a lack of pressure-bearing sealing structures suitable for the outer enclosure of new fuel assembly transport containers in cryogenic reactors. Existing pressure-bearing sealing structures typically employ rigid structures and materials to ensure high strength and stiffness at the pressure-bearing boundaries of the new fuel assembly transport container, thereby ensuring structural integrity and sealing after mechanical transport events / accidents. However, existing rigid outer enclosure pressure-bearing sealing structures cannot effectively dissipate mechanical impact energy to reduce the energy consumption of the new fuel assemblies, thus making the new fuel assemblies more susceptible to damage. Summary of the Invention

[0004] This application is made in view of the state of the prior art described above. The object of this application is to provide an outer enclosure for a novel fuel assembly transport container and a novel fuel assembly transport container, which can overcome or mitigate at least one of the disadvantages described in the background art above.

[0005] To achieve the above objectives, this application adopts the following technical solution.

[0006] This application provides an outer enclosure for a novel fuel assembly transport container, comprising: an outer shell for sealingly accommodating a novel fuel assembly; and an energy-absorbing assembly including a support ring, a support, an energy-absorbing ring, and an energy-absorbing shroud. The support ring has a thickness in the axial direction and a height in the radial direction of the outer enclosure, the support ring being fitted onto the outer shell. The support is at least partially formed into a U-shape, the two tops of the U-shape being fixedly connected to the outer peripheral surface of the outer shell, and the bottom of the U-shape protruding radially outward from the outer shell. The energy-absorbing ring defines an annular hollow cavity, the energy-absorbing ring being fitted onto the outer shell. The energy-absorbing shroud is conical and defines a conical hollow shroud cavity, the energy-absorbing shroud being disposed at an end of the outer shell and tapering axially away from the outer shell. The support ring, the support, and the energy-absorbing ring are capable of deforming radially to absorb energy, thereby cushioning impacts on the outer enclosure in the radial direction, and the energy-absorbing shroud is capable of deforming axially to absorb energy, thereby cushioning impacts on the outer enclosure in the axial direction.

[0007] In one alternative embodiment, the outer casing includes an outer cylinder, a bottom plate, and an end cap. The outer cylinder is fitted onto the new fuel assembly. The bottom plate is located at one axial end of the outer cylinder and is fixedly connected to the outer cylinder. The end cap is located at the other axial end of the outer cylinder and is detachably connected to the outer cylinder.

[0008] In another alternative embodiment, the bracket and the reinforcing ring are fixedly connected to the outer cylinder. The two tops of the U-shaped structure of the bracket are connected to the outer circumferential surface of the outer cylinder. The two tops are arranged circumferentially along the outer shell. The reinforcing ring is sleeved on the outer cylinder. The inner circumferential portion of the reinforcing ring is connected to the outer circumferential surface of the outer cylinder. The reinforcing ring passes through the two tops circumferentially.

[0009] In another alternative embodiment, the energy-absorbing ring includes an inner peripheral wall, an outer peripheral wall, and an end wall. The inner peripheral wall is coaxially disposed radially inside the outer peripheral wall. The end wall is annular and has a thickness in the axial direction, which gradually decreases from the radially inner side to the radially outer side. The two end walls are spaced apart in the axial direction. The inner peripheral wall, the outer peripheral wall, and the two end walls together enclose the hollow annular cavity. One of the two energy-absorbing rings is fitted onto the bottom plate of the outer shell, and the inner peripheral wall and the end wall of the first ring are integrally formed with the bottom plate of the outer shell. The other of the two energy-absorbing rings is fitted onto the end cap, and the inner peripheral wall and the end wall of the second ring are integrally formed with the end cap.

[0010] In another alternative embodiment, one of the two energy-absorbing hoods is fixedly connected to one axial end face of the bottom plate of the outer casing and tapers towards that axial side, while the other of the two energy-absorbing hoods is fixedly connected to the other axial end face of the end cap and tapers towards that axial side.

[0011] In another alternative embodiment, the bottom of the support is radially higher than the outer periphery of the energy-absorbing ring, and the outer periphery of the energy-absorbing ring is radially higher than the outer periphery of the support ring.

[0012] In another alternative embodiment, the energy-absorbing shroud includes a deformation hole and a drainage hole. The deformation hole extends through the small-diameter end of the energy-absorbing shroud along the axial direction, and the hollow shroud cavity is connected to the outside of the energy-absorbing shroud via the deformation hole. The drainage hole extends through the large-diameter end of the energy-absorbing shroud along the radial direction, and liquid in the hollow shroud cavity is discharged from the hollow shroud cavity via the drainage hole.

[0013] In another alternative embodiment, the bracket includes a first mounting hole and a second mounting hole. The bottom of the U-shaped structure of the bracket includes a first mounting portion and a second mounting portion. The first mounting portion and the second mounting portion are arranged perpendicularly to each other and are formed in an L-shape. The first mounting hole penetrates the first mounting portion in the thickness direction, and the second mounting hole penetrates the second mounting portion in the thickness direction. A plurality of new fuel assembly transport containers can be arranged horizontally, and the first mounting portions of adjacent left and right new fuel assembly transport containers can abut against each other. A positioning member can pass through the first mounting hole to fix the adjacent left and right new fuel assembly transport containers to each other. Furthermore, a plurality of new fuel assembly transport containers can be arranged vertically, and the second mounting portions of adjacent upper and lower new fuel assembly transport containers can abut against each other. A positioning member can pass through the second mounting hole to fix the adjacent upper and lower new fuel assembly transport containers to each other.

[0014] In another alternative embodiment, the outer casing includes a rupture hole, and the outer casing further includes a self-melting rupture assembly. The self-melting rupture assembly includes a rupture disc, a clamping screw, a first rupture gasket, and a second rupture gasket. The rupture disc closes the rupture hole, and the first and second rupture gaskets clamp the rupture disc. The clamping screw is screwed into the outer casing and is rotatable to apply pressure to the rupture disc through the first rupture gasket, causing the first and second rupture gaskets to clamp the rupture disc. The rupture disc is configured to melt at a predetermined temperature value or temperature range, such that the inner side of the outer casing communicates with the outer side of the outer casing via the rupture hole.

[0015] This application also provides a novel fuel assembly transport container, comprising: the aforementioned outer enclosure; an inner enclosure for accommodating the novel fuel assembly, wherein the outer enclosure accommodates the inner enclosure; and a thermal insulation structure comprising thermal insulation material, wherein the thermal insulation structure is disposed between the inner enclosure and the outer enclosure.

[0016] By employing the above technical solution, energy-absorbing components are installed on the outer shell. These components absorb the axial and radial impact energy of the new fuel assembly transport container through deformation, thereby effectively reducing the pressure boundary of the outer shell and the energy consumption of the new fuel assembly. In the event of a transport incident / accident of the same or equivalent level as the mechanical test listed in GB11806 during the transport of the new fuel assembly, the new fuel assembly transport container can ensure the structural integrity and sealing of the outer shell, mitigating the degree of damage to the new fuel assembly and thus preventing the release of radioactive materials into the external environment. Attached Figure Description

[0017] Figure 1 A schematic diagram of a novel fuel assembly transport container according to an embodiment of this application is shown.

[0018] Figure 2 It shows Figure 1 End view of the new fuel assembly transport container.

[0019] Figure 3 It shows Figure 1 Exploded view of the transport container for the new fuel assembly.

[0020] Figure 4 It shows Figure 3 A schematic diagram of the inner enclosure of the new fuel assembly transport container.

[0021] Figure 5 It shows Figure 3 A schematic diagram of the insulation structure of the new fuel assembly transport container.

[0022] Figure 6 It shows Figure 1 A cross-sectional view of the outer shell and bottom plate of the new fuel assembly transport container.

[0023] Figure 7 It shows Figure 1 A cross-sectional view of the end cap of the outer enclosure of the new fuel assembly transport container.

[0024] Figure 8 It shows Figure 7 A partial cross-sectional view of the self-melting explosive assembly of the outer enclosure.

[0025] Explanation of reference numerals in the attached figures

[0026] 1. Inner shell; 11. Inner cylinder; 12. Inner shell bottom plate; 13. Inner shell cover plate;

[0027] 2. Outer enclosure;

[0028] 21 Outer shell; 211 Outer cylinder; 212 Outer shell base plate; 213 End cap; 21a Burst hole;

[0029] 22 Energy-absorbing component; 221 Support ring; 222 Bracket; 223 Energy-absorbing ring; 224 Energy-absorbing cover; 225 First mounting part; 226 Second mounting part; 227 Inner peripheral wall; 228 Outer peripheral wall; 229 End wall; 22a Lifting hole; 22b First mounting hole; 22c Second mounting hole; 22d Hollow annular cavity; 22e Hollow cover cavity; 22f Deformation hole;

[0030] 23 Self-melting rupture assembly; 231 Rupture disc; 232 Clamping screw; 233 First rupture gasket; 234 Second rupture gasket;

[0031] 24 Valve core;

[0032] 25. End cap handle;

[0033] 3. Thermal insulation structure; 31. Thermal insulation cylinder; 32. Thermal insulation base; 33. Thermal insulation cover;

[0034] A represents the axial direction; R represents the radial direction; C represents the circumferential direction. Detailed Implementation

[0035] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0036] In this application, unless otherwise specified, "vibration damping material" refers to a material with vibration damping function, and "one being threaded into another" means that one is threadedly connected to another. "One being higher than the other in a certain direction" means that, viewed from that direction, the minimum distance between one and the central axis is greater than the minimum distance between the other and the central axis.

[0037] Figures 1 to 8 A novel fuel assembly transport container according to an embodiment of this application is shown, particularly a novel fuel assembly transport container suitable for boxed nuclear fuel assemblies in cryogenic reactors.

[0038] Reference Figures 1 to 3 The new fuel assembly transport container may include an inner enclosure 1, an outer enclosure 2, and a heat insulation structure 3. The inner enclosure 1 can accommodate the new fuel assembly, the outer enclosure 2 can accommodate the inner enclosure 1, and the heat insulation structure 3 can be disposed between the inner enclosure 1 and the outer enclosure 2.

[0039] Reference Figure 3 and Figure 4 The inner enclosure 1 may include an inner housing and an accelerometer mounting component.

[0040] The inner shell may include an inner cylinder 11, an inner shell bottom plate 12, and an inner shell cover plate 13. Specifically, the inner shell may be made of stainless steel, for example, austenitic stainless steel. The inner shell bottom plate 12 may be disposed at one axial end of the inner cylinder 11 and screwed onto the inner cylinder 11. The inner shell cover plate 13 may be disposed at the other axial end of the inner cylinder 11 and screwed onto the inner cylinder 11. The inner cylinder 11 may be fitted onto a new fuel assembly, thereby limiting the new fuel assembly in the radial direction R. The inner shell bottom plate 12 may be disposed on one axial side of the new fuel assembly, and the inner shell cover plate 13 may be disposed on the other axial side of the new fuel assembly, thereby limiting the new fuel assembly in the axial direction A.

[0041] Accelerometers are used to measure the vibration acceleration during the transport of new fuel assemblies. Specifically, the accelerometers can be fixedly mounted on top of the fuel assembly using accelerometer mounting components. Multiple accelerometers can be used, each measuring acceleration in multiple different directions, such as orthogonal directions. The accelerometers can have a settable overload threshold, for example, 4g or 6g. During transport, once the vibration acceleration characterizing the new fuel assembly reaches this overload threshold, the accelerometers can be triggered, and the overload event is recorded.

[0042] Reference Figures 1 to 3 as well as Figures 6 to 8 The outer casing 2 may include an outer casing 21, an energy-absorbing component 22, a self-melting explosion component 23, a valve core 24, and an end cap handle 25.

[0043] The outer casing 21 may include an outer cylinder 211, a bottom plate 212, and an end cap 213. Specifically, the outer casing 21 may be made of stainless steel, for example, austenitic stainless steel. The bottom plate 212 may be disposed at one axial end of the outer cylinder 211. Figure 6 The end cap 213 can be disposed at the right end of the outer cylinder 211 and welded to the outer cylinder 211. Figure 6The outer casing 211 is detachably and sealingly connected to the outer shell 211, for example, by providing a sealing ring and bolted fasteners between the end cap 213 and the outer shell 211, making the outer shell 21 a pressure-sealed structure. The end cap 213 may have a rupture hole 21a, which may be a stepped through-hole with internal threads. When a new fuel assembly needs to be loaded or unloaded, the outer casing 211 is in an upright position, allowing the new fuel assembly to be inserted or removed. The outer shell 211 and the end cap 213 may have corresponding lead-sealed holes. Lead seals may be installed on the outer shell 211 and the end cap 213, giving the outer casing nuclear safety functionality.

[0044] The energy-absorbing component 22 may include a support ring 221, a bracket 222, an energy-absorbing ring 223, and an energy-absorbing cover 224.

[0045] The support ring 221 can be fixedly connected to the outer cylinder 211. Specifically, the support ring 221 can be made of stainless steel, such as austenitic stainless steel, and can have a thickness in the axial direction A and a height in the radial direction R. The support ring 221 can be sleeved on the outer cylinder 211, and the inner circumference of the support ring 221 is fixedly connected to the outer circumferential surface of the outer cylinder 211, for example, it can be welded to the outer cylinder 211. Multiple support rings 221 can be arranged spaced apart in the axial direction A, for example, two support rings 221 can be respectively set at the two ends of the outer cylinder 211 in the axial direction. The support ring 221 can be provided with lifting holes 22a, and multiple lifting holes 22a can be evenly arranged in the circumferential direction C. The lifting holes 22a can pass through the support ring 221 in the axial direction A, and the shaft or lifting rope of the special lifting tool used for lifting the new fuel assembly transport container can pass through the lifting holes 22a.

[0046] The support 222 can be fixedly connected to the outer cylinder 211 and the reinforcing ring 221. Specifically, the support 222 can be made of stainless steel, for example, austenitic stainless steel. The support 222 can be formed into a U-shaped structure, with the two tops of the U-shaped structure fixedly connected to the outer circumferential surface of the outer cylinder 211, for example, by welding to the outer cylinder 211, and the bottom of the U-shaped structure can protrude radially outward from the outer cylinder 211. A slot can be cut at the center of the two tops of the U-shaped structure, with the slot width equal to the thickness of the reinforcing ring 221, and the two tops can be arranged circumferentially C. The reinforcing ring 221 can pass through the two tops circumferentially C and be fixedly connected to the support 222, for example, by welding to the support 222. The energy-absorbing assembly 22 can include multiple sets of supports 222 spaced apart in the axial direction A, and each set of supports 222 can include multiple supports 222 evenly spaced in the circumferential direction C. For example, in this embodiment, the energy absorption component 22 may include two sets of supports 222, the two sets of supports 222 are aligned in the circumferential C direction, each set of supports 222 may include four supports 222, the four supports 222 may be evenly arranged at 90° offset.

[0047] The bottom of the U-shaped structure may include a first mounting portion 225 and a second mounting portion 226. Specifically, the first mounting portion 225 and the second mounting portion 226 may be arranged perpendicularly to each other and formed in an L-shape. The two tops of the U-shaped structure may be respectively connected to the two ends of the L-shape. The first mounting portion 225 may be provided with a first mounting hole 22b, which penetrates the first mounting portion 225 in the thickness direction. The second mounting portion 226 may be provided with a second mounting hole 22c, which penetrates the second mounting portion 226 in the thickness direction. During transportation, the first mounting portion 225 may be arranged vertically, and the second mounting portion 226 may be arranged horizontally. Multiple new fuel assembly transport containers may be arranged horizontally, and the first mounting portions 225 of adjacent new fuel assembly transport containers may abut against each other. Bolts or locating pins (examples of locating members) may pass through the first mounting holes 22b to fix adjacent new fuel assembly transport containers to each other. Multiple new fuel assembly transport containers can be arranged vertically, with the second mounting portions 226 of adjacent new fuel assembly transport containers abutting against each other. Bolts or locating pins (examples of locating members) can pass through the second mounting holes 22c to secure the adjacent new fuel assembly transport containers to each other.

[0048] The energy-absorbing ring 223 may include an inner peripheral wall 227, an outer peripheral wall 228, and an end wall 229. Specifically, the energy-absorbing ring 223 may be made of stainless steel, such as austenitic stainless steel. The inner peripheral wall 227 and the outer peripheral wall 228 may be arranged coaxially, with the inner peripheral wall 227 located radially inside the outer peripheral wall 228. The end wall 229 may be annular, having a thickness in the axial direction A and a height in the radial direction R. The thickness of the end wall 229 may gradually decrease from the radially inner side to the radially outer side, such that the cross-section of the end wall 229 is trapezoidal, thereby enabling the energy-absorbing ring 223 to have variable stiffness in the radial direction R. The inner peripheral portion of the end wall 229 may be connected to the inner peripheral wall 227, and the outer peripheral portion of the end wall 229 may be connected to the outer peripheral wall 228. The two end walls 229 can be spaced apart axially A, such that the inner peripheral wall 227, the outer peripheral wall 228, and the two end walls 229 together enclose an annular hollow cavity 22d. Two energy-absorbing rings 223 can be respectively disposed on the outer casing base plate 212 and the end cap 213. The outer periphery of the outer casing base plate 212 and the end cap 213 can integrally form the inner peripheral wall 227 and the end wall 229, and the outer peripheral wall 228 can be welded to the outer casing base plate 212 and the end cap 213. For example, in this embodiment, an annular groove can be machined on the outer periphery of the outer casing base plate 212 and the end cap 213 to form the inner peripheral wall 227 and the end wall 229, making the energy-absorbing ring 223 easy to machine.

[0049] The energy-absorbing cover 224 can define a hollow cavity 22e. Specifically, the energy-absorbing cover 224 can be made of stainless steel, for example, austenitic stainless steel. The energy-absorbing cover 224 can be conical and define a conical hollow cavity 22e. A deformation hole 22f can be provided at the small-diameter end of the energy-absorbing cover 224. The deformation hole 22f can penetrate the energy-absorbing cover 224 along the axial direction A, so that the small-diameter end of the energy-absorbing cover 224 forms an annular end wall. For example, in this embodiment, the end wall of the energy-absorbing cover 224 can be an annular plate that can be welded to the peripheral wall of the energy-absorbing cover 224. The hollow cavity 22e can communicate with the outside of the energy-absorbing cover 224 through the deformation hole 22f, thereby facilitating the operation of the self-melting explosion assembly 23, the valve core 24, and the end cap handle 25. A drain hole can be provided at the large-diameter end of the energy-absorbing cover 224. The drain hole can penetrate the energy-absorbing cover 224 radially R. For example, the drain hole can be an irregularly shaped hole with a length in the circumferential direction C. Rainwater entering the hollow cover cavity 22e can be discharged from the hollow cover cavity 22e through the drain hole to prevent rainwater from accumulating in the hollow cover cavity 22e. Two energy-absorbing covers 224 can be respectively provided on the bottom plate 212 of the outer shell and the end cap 213. One energy-absorbing cover 224 can be welded to one axial side of the bottom plate 212 of the outer shell. Figure 6 (to the right of the middle), and to one side of the axis ( Figure 6 (Right side) tapers. Another energy-absorbing shield 224 can be welded to the other axial side of the end cap 213 ( Figure 7 (on the upper side), and gradually tapering towards the other side of the axis ( Figure 7 (The upper side of the middle).

[0050] The support ring 221, bracket 222, and energy-absorbing ring 223 can buffer radial impact loads. Specifically, the bottom of the U-shaped structure of the bracket 222 can be higher than the outer periphery of the energy-absorbing ring 223 at any radial angle R, and the outer periphery of the energy-absorbing ring 223 can be higher than the outer periphery of the support ring 221 at any radial angle R. For example, in this embodiment, the support ring 221, bracket 222, and energy-absorbing ring 223 can... Figure 2The height requirements are met in both the horizontal direction and the direction offset by 45° on the paper. When the new fuel assembly transport container is subjected to an impact in the radial direction R, the support 222 can deform radially inward as a first-stage energy-absorbing section to dissipate the energy acting on the new fuel assembly transport container. As the deformation deepens radially inward, the portion of the support 222 above the outer periphery of the support ring 221 in the radial direction R, together with the energy-absorbing ring 223, can deform radially inward as a second-stage energy-absorbing section to dissipate the energy acting on the new fuel assembly transport container. Furthermore, the support 222, the energy-absorbing ring 223, and the support ring 221 can deform radially inward as a third-stage energy-absorbing section to dissipate the energy acting on the new fuel assembly transport container. By combining the support ring 221, the support 222, and the energy-absorbing ring 223, the stiffness of the first-stage, second-stage, and third-stage energy-absorbing sections can be increased sequentially, giving the energy-absorbing assembly 22 variable stiffness performance in the radial direction R.

[0051] The energy-absorbing shield 224 can buffer axial impact loads. Specifically, when the new fuel assembly transport container is subjected to an axial impact A, the energy-absorbing shield 224 can deform in the axial direction A to dissipate the energy acting on the new fuel assembly transport container. For example, in this embodiment, the energy-absorbing shield 224 disposed on the bottom plate 212 of the outer casing can deform to the other side in the axial direction ( Figure 6 (on the left side), the energy-absorbing shroud 224 disposed on the end cap 213 can be axially directed to one side ( Figure 7 (The lower side of the middle) is deformed.

[0052] Reference Figure 8 The self-melting explosive assembly 23 may include a rupture disc 231, a clamping screw 232, a first rupture pad 233, and a second rupture pad 234. Specifically, the first rupture pad 233 and the second rupture pad 234 may be annular. The rupture disc 231, the first rupture pad 233, and the second rupture pad 234 may be stacked in axial direction A, with the rupture disc 231 located between the first rupture pad 233 and the second rupture pad 234. The rupture disc 231, the first rupture pad 233, and the second rupture pad 234 may be located within the rupture hole 21a, with one axial end of the second rupture pad 234 ( Figure 8 The lower end of the screw 232 can abut against the shoulder of the rupture hole 21a. The clamping screw 232 can be cylindrical, and its outer circumferential surface can be provided with external threads corresponding to the rupture hole 21a. The clamping screw 232 can be screwed into the end cap 213, and the axial end of the clamping screw 232 ( Figure 8 The lower end of the first burst pad 233 can abut against the other axial end of the first burst pad 233. Figure 8The upper end of the first rupture pad 233 and the second rupture pad 234 clamp the rupture disc 231. The first rupture pad 233 and the second rupture pad 234 can be made of copper and can be used as sealing gaskets. The rupture disc 231 can be made of tin alloy and can seal the rupture hole 21a. In high-temperature conditions, such as a fire accident, the rupture disc 231 can melt within a predetermined temperature range, allowing gas inside the outer casing 21 to escape through the rupture hole 21a, thereby preventing the explosion of the new fuel assembly transport container.

[0053] Reference Figure 7 Valve core 24 and end cap handle 25 can be disposed on end cap 213. Specifically, housing 21 can contain a protective gas, such as nitrogen, to prevent oxidation of new fuel assemblies during transportation and temporary storage. Valve core 24 can be mounted on end cap 213, and protective gas can be introduced into housing 21 through valve core 24. End cap handle 25 can be disposed on the opposite axial end face of end cap 213 and welded to end cap 213. End cap handle 25 can be integrally located within hollow cavity 22e, and two end cap handles 25 can be radially spaced apart.

[0054] Reference Figure 3 and Figure 5 The heat insulation structure 3 may include a heat insulation cylinder 31, a heat insulation base 32, and a heat insulation cover 33. Specifically, the heat insulation cylinder 31 may be fitted onto the inner cylinder 11, the heat insulation base 32 may abut against one axial end of the inner shell, and the heat insulation cover 33 may abut against the other axial end of the inner shell. The heat insulation cylinder 31 may include heat insulation material, enabling the transport container to have good heat insulation performance in a fire accident, ensuring that the surface temperature of the new fuel assembly does not exceed the design limit, thereby ensuring that the radioactive material of the new fuel assembly will not leak into the external environment. The heat insulation base 32 and the heat insulation cover 33 may include heat insulation material and vibration damping material, which may be stacked in axial direction A. The heat insulation material may be composite fiber, such as aluminosilicate composite fiber. The vibration damping material may be wood, such as pine wood.

[0055] In this way, by setting up the energy-absorbing component 22, when a transportation event / accident of the same or equivalent level as the mechanical test listed in GB11806 occurs during the transportation of the new fuel assembly, it can mitigate the impact on the outer enclosure shell in the axial A and radial R directions to ensure the structural integrity of the outer enclosure shell and maintain its sealing performance. This can effectively reduce the energy consumption of the new fuel assembly to alleviate the degree of damage to the new fuel assembly, thereby preventing the release of radioactive materials into the external environment.

[0056] It should be understood that the above embodiments are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above embodiments under the teachings of this application without departing from the scope of this application.

[0057] It should be understood that the inner peripheral wall 227 and the end wall 229 are not limited to being integrally formed with the housing base plate 212 and the end cover 213. For example, the end wall 229 can be fixedly mounted to the housing base plate 212 and the end cover 213.

[0058] It should be understood that the rupture disc 231 is not limited to being made of an alloy; for example, it can be made of a pure metal, such that the rupture disc 231 can melt at a predetermined temperature (the melting point of the pure metal). The rupture disc 231 is not limited to being made of metal; for example, it can be made of plastic or nylon.

[0059] It should be understood that the protective gas is not limited to nitrogen; for example, it can be an inert gas.

Claims

1. An outer enclosure for a novel fuel assembly transport container, characterized in that, include: The outer casing (21) is used to hermetically house the new fuel assembly; as well as An energy-absorbing assembly (22) includes a support ring (221), a bracket (222), an energy-absorbing ring (223), and an energy-absorbing cover (224). The support ring (221) has a thickness in the axial direction (A) and a height in the radial direction (R) of the outer enclosure shell (2). The support ring (221) is fitted onto the outer shell (21). The bracket (222) is at least partially formed into a U-shaped structure. The two tops of the U-shaped structure are fixedly connected to the outer peripheral surface of the outer shell (21). The bottom of the U-shaped structure protrudes radially outward from the outer shell (21). The inner peripheral portion of the support ring (221) is connected to the outer peripheral surface of the outer cylinder (211) of the outer shell (21). The support ring (221) passes through the two tops of the U-shaped structure along the circumferential direction (C) of the outer enclosure shell (2). The energy-absorbing ring (223) defines an annular hollow cavity (22d). 23) Sleeved onto the outer shell (21), the energy-absorbing ring (223) includes an inner peripheral wall (227), an outer peripheral wall (228), and an end wall (229). The inner peripheral wall (227) is coaxially disposed on the radially inner side of the outer peripheral wall (228). The end wall (229) is annular, and the two end walls (229) are spaced apart in the axial direction (A). The inner peripheral wall (227), the outer peripheral wall (228), and the two end walls (229) together enclose the hollow annular cavity (22d), the end wall (229) has a thickness in the axial direction (A), the thickness gradually decreasing from the radially inner side to the radially outer side, the energy-absorbing shroud (224) is conical and defines a conical hollow shroud cavity (22e), the energy-absorbing shroud (224) is disposed at the end of the outer shell (21) and tapers away from the outer shell (21) in the axial direction (A), wherein The support ring (221), the bracket (222), and the energy-absorbing ring (223) can deform and absorb energy in the radial direction (R) to buffer the impact on the outer enclosure shell (2) in the radial direction (R), and The energy-absorbing shield (224) is capable of deforming and absorbing energy in the axial direction (A) to cushion the impact on the outer enclosure shell (2) in the axial direction (A). The bottom of the support (222) is higher than the outer periphery of the energy-absorbing ring (223) in the radial direction (R), and the outer periphery of the energy-absorbing ring (223) is higher than the outer periphery of the support ring (221) in the radial direction (R). The support (222) serves as the first-stage energy-absorbing segment on its own. The portion of the support (222) that is higher than the outer periphery of the support ring (221) in the radial direction (R) and the energy-absorbing ring (223) together serve as the second-stage energy-absorbing segment. The support (222), the energy-absorbing ring (223), and the support ring (221) together serve as the third-stage energy-absorbing segment. The stiffness of the first-stage, second-stage, and third-stage energy-absorbing segments increases sequentially. The bracket (222) includes a first mounting hole (22b) and a second mounting hole (22c). The bottom of the U-shaped structure of the bracket (222) includes a first mounting portion (225) and a second mounting portion (226). The first mounting portion (225) and the second mounting portion (226) are arranged perpendicularly to each other and are formed in an L-shape. The first mounting hole (22b) penetrates the first mounting portion (225) in the thickness direction, and the second mounting hole (22c) penetrates the second mounting portion (226) in the thickness direction. Multiple new fuel assembly transport containers can be arranged horizontally, with the first mounting portions (225) of adjacent new fuel assembly transport containers abutting against each other. A positioning member can pass through the first mounting hole (22b), thus fixing adjacent new fuel assembly transport containers to each other. Multiple new fuel assembly transport containers can be arranged vertically, and the second mounting portions (226) of adjacent new fuel assembly transport containers can abut against each other. The positioning member can pass through the second mounting hole (22c) so that the adjacent new fuel assembly transport containers are fixed to each other.

2. The outer enclosure according to claim 1, characterized in that, The outer casing (21) includes an outer cylinder (211), a bottom plate (212), and an end cap (213). The outer cylinder (211) is used to fit the new fuel assembly. The bottom plate (212) is located at one axial end of the outer cylinder (211) and is fixedly connected to the outer cylinder (211). The end cap (213) is located at the other axial end of the outer cylinder (211) and is detachably connected to the outer cylinder (211).

3. The outer enclosure according to claim 2, characterized in that, The bracket (222) and the reinforcing ring (221) are fixedly connected to the outer cylinder (211). The two tops of the U-shaped structure of the bracket (222) are connected to the outer circumferential surface of the outer cylinder (211). The two tops are arranged along the circumferential direction (C) of the outer enclosure shell (2). The reinforcing ring (221) is sleeved on the outer cylinder (211).

4. The outer enclosure according to claim 2, characterized in that, One of the two energy-absorbing rings (223) is fitted onto the bottom plate of the outer casing (212), and the inner peripheral wall (227) and the end wall (229) of the first ring are integrally formed with the bottom plate of the outer casing (212). The other of the two energy-absorbing rings (223) is fitted onto the end cap (213), and the inner peripheral wall (227) and the end wall (229) of the second ring are integrally formed with the end cap (213).

5. The outer enclosure according to claim 2, characterized in that, One of the two energy-absorbing covers (224) is fixedly connected to one axial end face of the bottom plate (212) of the outer shell and tapers towards one axial side, while the other of the two energy-absorbing covers (224) is fixedly connected to the other axial end face of the end cap (213) and tapers towards the other axial side.

6. The outer enclosure according to any one of claims 1 to 5, characterized in that, The energy-absorbing hood (224) includes a deformation hole (22f) and a drain hole. The deformation hole (22f) extends through the small-diameter end of the energy-absorbing hood (224) along the axial direction (A). The hollow hood cavity (22e) can communicate with the outside of the energy-absorbing hood (224) through the deformation hole (22f). The drain hole extends through the large-diameter end of the energy-absorbing hood (224) along the radial direction (R). Liquid in the hollow hood cavity (22e) can be discharged from the hollow hood cavity (22e) through the drain hole.

7. The outer enclosure according to any one of claims 1 to 5, characterized in that, The outer shell (21) includes a burst hole (21a), and the outer shell (2) also includes a self-melting burst assembly (23). The self-melting explosive assembly (23) includes a rupture disc (231), a clamping screw (232), a first rupture pad (233), and a second rupture pad (234). The rupture disc (231) closes the rupture hole (21a). The first rupture pad (233) and the second rupture pad (234) clamp the rupture disc (231). The clamping screw (232) is screwed into the outer casing (21). The clamping screw (232) is rotatable to apply pressure to the rupture disc (231) through the first rupture pad (233), so that the first rupture pad (233) and the second rupture pad (234) clamp the rupture disc (231). The rupture disc (231) is configured to melt at a predetermined temperature value or temperature range, such that the inner side of the outer casing (21) communicates with the outer side of the outer casing (21) via the rupture hole (21a).

8. A novel fuel assembly transport container, characterized in that, include: The outer enclosure shell (2) according to any one of claims 1 to 7; An inner enclosure (1) is used to house the new fuel assembly, and an outer enclosure (2) houses the inner enclosure (1). as well as A heat insulation structure (3) comprising heat insulation material is disposed between the inner enclosure shell (1) and the outer enclosure shell (2).

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