Spent fuel container transport plant and spent fuel container transport method

Abstract

The present application relates to a kind of spent fuel container transport plant and spent fuel container transport method, including sequentially arranged loading shaft, preparation shaft and hoisting mouth, the communication or isolation between the preparation shaft and hoisting mouth is realized by gate, shock attenuation layer is equipped below the hoisting mouth;The height difference of preparation shaft bottom surface and fuel operation hall is not more than 9m, the height difference of preparation shaft bottom surface and the container transport vehicle below the hoisting mouth is not more than 9m;Water pump and isolation valve are equipped on the water filling and draining pipeline in the preparation shaft.The present application ensures the containment of radioactive material in loading shaft and preparation shaft after the drop accident of spent fuel container occurs by setting temporary water filling and draining system, setting gate to form stepped hoisting to reduce hoisting height, setting shock attenuation layer and other measures, can ensure the integrity of spent fuel container sealing boundary in hoisting mouth, reduce the risk of large release of radioactive material to environment after the drop accident of spent fuel container occurs.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant layout technology, and in particular to a spent fuel container transport facility and a spent fuel container transport method. Background Technology

[0002] After the spent fuel assemblies unloaded from the nuclear power plant reactor have cooled and decayed in the spent fuel pool for a period of time, they need to be loaded into spent fuel containers for offloading to free up storage space for subsequent refueling cycles. Currently, nuclear power units use the "container immersion method" for loading spent fuel assemblies. This involves first using a crane to lift empty spent fuel containers into the loading well and immersing them in water, then loading the spent fuel assemblies underwater. Next, the fully loaded spent fuel containers are lifted into the preparation well for cleaning, sealing, and other preparatory operations before offloading. Finally, they are lifted from the fuel operation hall to spent fuel transport vehicles parked on the ground for offloading.

[0003] The current waste fuel transportation process has the following shortcomings:

[0004] (1) Based on feedback from the current operating experience of nuclear power plants, human error is an important factor leading to hoisting fall accidents, and this is a risk that cannot be completely eliminated no matter how reliable the equipment is.

[0005] (2) The loading well and the spent fuel pool are connected by a sluice gate. If an opening is set at the bottom of the loading well to dock with the container for loading spent fuel, it is not conducive to maintaining the integrity of the spent fuel pool boundary, increases the risk of spent fuel pool leakage, and does not significantly reduce the overall risk level of the nuclear power plant.

[0006] (3) Currently, not all large commercial nuclear power plant reactors in China adopt fully modular construction. The fuel operation hall is relatively high above the ground, and the cost of overall negative excavation to lower the elevation is very high. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a spent fuel container transportation plant and a spent fuel container transportation method.

[0008] The technical solution adopted by this invention to solve its technical problem is as follows: Constructing a spent fuel container transportation plant, including a loading well, a preparation well, and a hoisting port arranged in sequence. The preparation well and the hoisting port are connected or separated by a gate. A shock-absorbing layer is provided below the hoisting port. The height difference between the bottom surface of the preparation well and the fuel operation hall is no greater than 9m, and the height difference between the bottom surface of the preparation well and the container transport vehicle below the hoisting port is no greater than 9m. A filling and draining pipeline is provided in the preparation well, and a water pump and an isolation valve are provided on the filling and draining pipeline.

[0009] Preferably, the filling and draining pipeline connects the preparation well and the loading well.

[0010] Preferably, the side wall of the hoisting port is provided with a hanging bracket; the back of the gate is provided with a support for hanging on the hanging bracket, and the top of the gate is provided with a hoisting lug assembly for hoisting.

[0011] Preferably, the shock-absorbing layer is disposed on the mobile vehicle.

[0012] Preferably, the spent fuel container transport building is provided with a storage space for accommodating the shock-absorbing layer.

[0013] Preferably, the preparation well is provided with an upper platform that can be enclosed around the spent fuel container.

[0014] Preferably, the upper platform includes a first fixed part and a first movable part. The first fixed part is fixedly connected to the side wall of the preparation well, and the first movable part is disposed on the side near the gate. The first movable part and the first fixed part are detachably connected.

[0015] Preferably, the preparation well is provided with a lower platform that can be surrounded around the spent fuel container.

[0016] Preferably, the lower platform includes a second fixed part and a second movable part. The second fixed part is fixedly connected to the side wall of the preparation well, and the second movable part is disposed on the side near the gate. The second movable part and the second fixed part are detachably connected.

[0017] The present invention also provides a method for transporting spent fuel containers, which is carried out within the spent fuel container transport facility described in any of the above claims; the method for transporting spent fuel containers includes the following steps:

[0018] S1. Connect the hoisting equipment to the spent fuel container inside the loading well;

[0019] S2. Fill the prepared well with water through the filling and draining pipeline;

[0020] S3. Lift the spent fuel container from the loading well, move it away from the loading well and to the top of the preparation well, and lower the spent fuel container into the preparation well.

[0021] S4. Drain the water in the prepared well through the filling and draining pipeline;

[0022] S5. Place the shock-absorbing layer below the hoisting opening, open the gate, lift the spent fuel container and move it horizontally into the hoisting opening;

[0023] S6. After the spent fuel container is lowered to a safe height, remove the shock-absorbing layer, move the container transport vehicle to below the hoisting port, and place the spent fuel container on the container transport vehicle.

[0024] Implementing this invention has the following beneficial effects: by setting up a temporary filling and drainage system, setting up gates to form a "stepped" hoisting to reduce the hoisting height, and setting up a shock-absorbing layer, it is ensured that after a spent fuel container falls, the radioactive material can be contained in the loading well and the preparation well, and the integrity of the sealed boundary of the spent fuel container can be ensured in the hoisting port, thereby reducing the risk of a large amount of radioactive material being released into the environment after a spent fuel container falls. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the elevation structure of a spent fuel container transport plant in some embodiments of the present invention;

[0027] Figure 2 This is a top view of the upper platform 22 in some embodiments of the present invention;

[0028] Figure 3 This is a top view of the lower platform 23 in some embodiments of the present invention. Detailed Implementation

[0029] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0030] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" 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. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0031] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0032] Figure 1 The illustration shows a spent fuel container transport facility according to some embodiments of the present invention. This facility can be used to reduce the risk of a large release of radioactive materials into the environment after a spent fuel container fall accident. It may include a loading well 10, a preparation well 20, and a hoisting port 30 arranged sequentially. The spent fuel pool 100 is used for storing spent fuel during nuclear power plant operation; the loading well 10 is used for loading spent fuel into spent fuel containers 200; the preparation well 20 is used for cleaning and inspecting spent fuel containers 200; and the hoisting port 30 is used for the entry and exit of new fuel, spent fuel containers 200, and other PMC (Nuclear Fuel Loading and Unloading Storage System) equipment into and out of the facility.

[0033] In some embodiments, the preparation well 20 and the hoisting port 30 are connected or separated by a gate 21. Preferably, the hoisting port 30 has a bracket on its side wall, the gate 21 has a support on its back for attaching to the bracket, and the top of the gate 21 has a lifting lug assembly for hoisting. When the spent fuel container 200 is being transported, the gate 21 is removed and attached to the bracket on the side wall of the hoisting port 30, and then the spent fuel container 200 is moved horizontally, forming a stepped hoisting process. Preferably, a leakage collection pipeline can be installed at the bottom of the gate 21 to prevent water containing low doses of radioactivity from leaking into the hoisting port 30 when the preparation well 20 is being filled with water.

[0034] Alternatively, the gate 21 can be opened and closed by means of a pull-out method, a lifting method, or a folding method. For example, when it is necessary to connect the preparation well 20 and the hoisting port 30, the gate 21 is pulled upward, so that the original position of the gate 21 forms an opening, allowing the spent fuel container 200 to pass through and enter the hoisting port 30. After the transfer is completed, the gate 21 is lowered, separating the preparation well 20 and the hoisting port 30.

[0035] Alternatively, where it is necessary to connect the preparation well 20 and the hoisting port 30, the gate 21 is lowered so that it enters the interlayer of the lower wall, thus creating an opening in the original position of the gate 21 to allow the spent fuel container 200 to pass through into the hoisting port 30. After the transfer is completed, the gate 21 is raised to separate the preparation well 20 and the hoisting port 30.

[0036] Alternatively, gate 21 can be pulled into the side wall. When it is necessary to connect the preparation well 20 and the hoisting port 30, gate 21 can be moved into the side wall, thus creating an opening in the original position of gate 21 to allow the spent fuel container 200 to pass through into the hoisting port 30. After the transfer is completed, gate 21 can be pulled out from the side wall, separating the preparation well 20 and the hoisting port 30.

[0037] Alternatively, gate 21 can be implemented as a foldable gate. When it is necessary to connect the preparation well 20 and the hoisting port 30, gate 21 can be folded to one side, thus forming an opening in the original position of gate 21, allowing the spent fuel container 200 to pass through and enter the hoisting port 30. After the transfer is completed, gate 21 can be unfolded to separate the preparation well 20 and the hoisting port 30.

[0038] The opening and closing of gate 21 can all be achieved by using corresponding drive mechanisms, reducing manual operation.

[0039] In some embodiments, a shock-absorbing layer 300 is provided below the hoisting opening 30. Preferably, the shock-absorbing layer 300 is made of foamed aluminum or wood and covered with a thin metal sheet such as stainless steel. The shock-absorbing layer 300 can be installed on a mobile vehicle such as a flatbed truck, so that the shock-absorbing layer can be shared by multiple units in the same power plant. The spent fuel container transport building is provided with a housing space 11 for accommodating the shock-absorbing layer 300. Preferably, the housing space 11 can be located in the space below the loading shaft 10.

[0040] In some embodiments, the height difference between the bottom of the preparation well 20 and the fuel operation hall 40 is no greater than 9m, and the height difference between the bottom of the preparation well 20 and the container transport vehicle below the hoisting port 30 is no greater than 9m. Specifically, as... Figure 1 In the illustrated embodiment, the elevation of the fuel handling hall 40 is +17.50m, the elevation of the preparation well 20 is +9.50m, and the loading surface height of the container transport vehicle is approximately 1m. That is, the spent fuel container 200 can be lifted from the fuel handling hall 40 to a height of 8m from the preparation well 20, and from the preparation well 20 to a height of 8.5m from the container transport vehicle. It is understood that the elevation of the fuel handling hall 40 is not limited to 17.5m, and the elevation of the preparation well 20 is not limited to 9.5m, as long as the lifting height of the spent fuel container 200 is within the 9m drop resistance range.

[0041] In some embodiments, the preparation well 20 is provided with a filling / drainage pipeline 24, which is equipped with a water pump and an isolation valve for controlling the filling or draining of water into the preparation well 20. Preferably, the filling / drainage pipeline 24 connects the preparation well 20 and the loading well 10, or connects to other pools within the fuel plant for water exchange between different pools. Before the spent fuel container 200 is hoisted from the loading well into the preparation well, the preparation well is filled with water so that the spent fuel container 200 can be submerged after falling into the preparation well. Even if the spent fuel container 200 suffers integrity damage, the radioactive consequences will not exceed the limit. After the spent fuel container 200 is in place in the preparation well 20, the water in the preparation well 20 can be drained back to other pools without needing to be treated as wastewater. It is understood that the preparation well 20 may also be provided with an independent filling / drainage pipeline 24 for filling or draining water.

[0042] like Figure 2As shown, the preparation well 20 is equipped with an upper platform 22 that can be installed around the outer periphery of the spent fuel container 200, facilitating operations such as bolt tightening, gas filling and drainage, vacuum drying, helium filling, and sealing checks on the spent fuel container 200 by operators on the upper platform 22. The upper platform 22 includes a first fixed part 221 and a first movable part 222. The first fixed part 221 is fixedly connected to the side wall of the preparation well 20, and the first movable part 222 is located on the side near the gate 21. The first fixed part 221 and the first movable part 222 have an arc-shaped concave shape that matches the outer peripheral surface of the spent fuel container 200, so that the upper platform 22 approaches the spent fuel container 200 through the concave shape. Operators can perform operations such as bolt tightening, gas filling and drainage, vacuum drying, helium filling, and sealing checks on the spent fuel container 200 at the edge of the concave shape. The first movable part 222 is detachably connected to the first fixed part 221. Specifically, the first fixed part 221 is provided with a slot, and the first movable part 222 is provided with a pin that cooperates with the first fixed part 221. Before hoisting the spent fuel container 200 to the hoisting hole 30, the first movable part 222 is removed from the first fixed part 221 and hoisted away from the preparation well 20 to make room for the translation of the spent fuel container 200. After the spent fuel container 200 is moved away, the first movable part 222 can be hoisted back to its original position and installed with the first fixed part 221 to form a complete ring of steel platform.

[0043] like Figure 3 As shown, the preparation well 20 is equipped with a lower platform 23 that can be installed around the outer periphery of the spent fuel container 200, facilitating operations such as bolt tightening, gas filling and drainage, vacuum drying, helium filling, and seal testing of the spent fuel container 200 by operators on the lower platform 23. The lower platform 23 includes a second fixed part 231 and a second movable part 232. The second fixed part 231 is fixedly connected to the side wall of the preparation well 20, and the second movable part 232 is located on the side near the gate 21. The second fixed part 231 and the second movable part 232 have arc-shaped concave edges that conform to the outer peripheral surface of the spent fuel container 200, allowing the lower platform 23 to approach the spent fuel container 200 through these concave edges. Operators can perform operations such as bolt tightening, gas filling and drainage, vacuum drying, helium filling, and seal testing of the spent fuel container 200 on the edge of these concave edges. The second movable part 232 is detachably connected to the second fixed part 231. Specifically, the second fixed part 231 is provided with a slot, and the second movable part 232 is provided with a pin that cooperates with the second fixed part 231. Before hoisting the spent fuel container 200 to the hoisting hole 30, the second movable part 232 is removed from the second fixed part 231 and hoisted away from the preparation well 20 to make room for the translation of the spent fuel container 200; after the spent fuel container 200 is moved away, the second movable part 232 can be hoisted back to its original position and installed with the second fixed part 231 to form a complete ring of steel platform.

[0044] Preferably, the upper platform 22 and the lower platform 23 can both be made of steel. In addition, guardrails are also provided on the upper platform 22 and the lower platform 23 to provide a certain degree of protection for operators and prevent dangers such as falls.

[0045] refer to Figures 1 to 3 The spent fuel container transportation method implemented within the spent fuel container transportation facility of the present invention may include the following steps:

[0046] S1. Connect the hoisting equipment 400 to the spent fuel container 200 inside the loading well 10.

[0047] Before step S1, spent fuel is pre-loaded into spent fuel container 200. This loading operation is mainly carried out within loading well 10. After the spent fuel loading is completed, spent fuel container 200 is mainly placed on the bearing bottom surface within loading well 10.

[0048] S2. Water is filled into the preparation well 20 through the filling and draining pipeline 24, so that even if the spent fuel container 200 falls into the preparation well 20, it can still be submerged in water, and even if the integrity is damaged, the radioactive consequences will not exceed the limit.

[0049] S3. Lift the spent fuel container 200 from the loading well 10, move it away from the loading well 10 and move it above the preparation well 20, and lower the spent fuel container 200 into the preparation well 20.

[0050] S4. The water in the preparation well 20 is drained through the filling and draining pipeline 24. Preferably, after the spent fuel container 200 is in place in the preparation well 20, the water in the preparation well 20 can be drained back to other pools and wells without needing to be treated as wastewater.

[0051] S5. Place the shock-absorbing layer 300 below the lifting port 30, open the gate 21, and lift and move the spent fuel container 200 into the lifting port 30. If the spent fuel container 200 falls, the shock-absorbing layer 300 can provide a cushioning effect.

[0052] S6. After the spent fuel container 200 is lowered to a safe height, the shock-absorbing layer 300 is removed, the container transport vehicle is moved to below the lifting port 30, and the spent fuel container 200 is placed on the container transport vehicle. Preferably, this safe height can be set to 2m.

[0053] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A spent fuel container transport plant characterized by, The fuel container transport plant comprises a loading well (10), a preparation well (20) and a lifting port (30) arranged in sequence, the preparation well (20) and the lifting port (30) are communicated or blocked by a gate (21), and a shock-absorbing layer (300) is arranged below the lifting port (30); the height difference between the bottom surface of the preparation well (20) and a fuel operation hall (40) is not greater than 9 m, and the height difference between the bottom surface of the preparation well (20) and a container transport vehicle below the lifting port (30) is not greater than 9 m; a water filling and draining pipeline (24) is arranged in the preparation well (20), and a water pump and an isolation valve are arranged on the water filling and draining pipeline (24); The water filling and draining pipeline (24) communicates the preparation well (20) and the loading well (10); Before the spent fuel container (200) is lifted from the loading well (10) into the preparation well (20), the preparation well (20) is first filled with water, so that the spent fuel container (200) can be immersed in water after falling into the preparation well (20), and even if the spent fuel container (200) is damaged in integrity, the radioactive consequence is still within the limit value.

2. The spent fuel container transport plant of claim 1, wherein, A hanger is arranged on the side wall of the lifting port (30); a support for leaning on the hanger is arranged on the back of the gate (21), and a lifting lug assembly for lifting is arranged on the top of the gate (21).

3. The spent fuel container transport plant of claim 1, wherein, The shock-absorbing layer (300) is arranged on a mobile carrier.

4. The spent fuel container transport plant of claim 1, wherein, The spent fuel container transport plant is provided with an accommodation space (11) for accommodating the shock-absorbing layer (300).

5. The spent fuel container transport plant of claim 1, wherein, An upper platform (22) which can be arranged around the periphery of the spent fuel container (200) is arranged in the preparation well (20).

6. The spent fuel container transport plant of claim 5, wherein, The upper platform (22) comprises a first fixed part (221) and a first movable part (222), the first fixed part (221) is fixedly connected to the side wall of the preparation well (20), the first movable part (222) is arranged on the side close to the gate (21), and the first movable part (222) is detachably connected to the first fixed part (221).

7. The spent fuel container transport plant of claim 1, wherein, A lower platform (23) which can be arranged around the periphery of the spent fuel container (200) is arranged in the preparation well (20).

8. The spent fuel container transport plant of claim 7, wherein, The lower platform (23) comprises a second fixed part (231) and a second movable part (232), the second fixed part (231) is fixedly connected to the side wall of the preparation well (20), the second movable part (232) is arranged on the side close to the gate (21), and the second movable part (232) is detachably connected to the second fixed part (231).

9. A spent fuel container transportation method characterized by, The spent fuel container transport method is carried out in the spent fuel container transport plant of any one of claims 1-8 and comprises the following steps: S1, connecting a lifting device (400) to the spent fuel container (200) in the loading well (10); S2, filling water into the preparation well (20) through the water filling and draining pipeline (24); S3, lifting the spent fuel container (200) from the loading well (10), moving the spent fuel container (200) above the preparation well (20), and lowering the spent fuel container (200) into the preparation well (20). S4, draining water in the preparation well (20) through the water filling and draining pipeline (24); S5, placing the shock-absorbing layer (300) below the hoisting opening (30), after opening the gate (21), hoisting the spent fuel container (200) and translating it into the hoisting opening (30); S6, removing the shock-absorbing layer (300) after the spent fuel container (200) is lowered to a safe height, moving the container transport vehicle below the hoisting opening (30), and placing the spent fuel container (200) on the container transport vehicle.

Images