A heavy water reactor spent fuel rod bundle underwater disassembly device and method

Abstract

This invention relates to the field of nuclear fuel technology, specifically disclosing an underwater dismantling device and method for spent fuel rod bundles in heavy water reactors. The device includes a dismantling base plate, an element separation lever, a limiting baffle, a force adjusting block, and a support arm. The dismantling base plate has a plate-like structure, with a horizontal surface on the left end and a downward slope from the middle to the right end. The junction of the horizontal surface and the slope is a rod bundle positioning groove. A support arm is vertically mounted on the right end of the dismantling base plate, and a force adjusting block perpendicular to the support arm is also provided within the track. A limiting baffle is located at the top of the support arm, and the right end of the support arm is movably connected to the limiting baffle. The left end of the limiting baffle is connected to the element separation lever via a rotating plate. This device has a simple structure, reliable performance, and effectively solves the problem of non-destructive dismantling of rod bundle elements.

Description

Technical Field

[0001] This invention belongs to the field of nuclear fuel technology, specifically relating to an underwater dismantling device and method for spent fuel rod bundles in a heavy water reactor. Background Technology

[0002] The Qinshan Nuclear Power Plant has two heavy water reactor units, which are currently the only two heavy water reactor units in China, using natural uranium. Due to the damage to the rod bundles during reactor use, the rod bundles need to be disassembled and inspected. In order to make full use of the spent fuel recycling of pressurized water reactor units—that is, to recover uranium—after the recovered uranium is first put into the reactor, after the reactor has been used for one cycle, the recovered uranium rod bundles need to be disassembled, and the components need to be removed one by one for inspection. The current underwater disassembly method is relatively outdated, using a long rod tool connected to a modified flathead screwdriver to pry open the rod bundles, which can easily cause secondary damage or breakage of the rod bundle components. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing an underwater dismantling device and method for spent fuel rod bundles in heavy water reactors, thereby solving the problem of secondary damage to rod bundle components during the underwater dismantling process of spent fuel rod bundles in heavy water reactors.

[0004] To solve the above problems, the technical solution of the present invention is as follows: an underwater dismantling device for spent fuel rod bundles of heavy water reactors, the device comprising a dismantling base plate, a component separation lever plate, a limiting baffle plate, a force adjusting block, and a support arm. The dismantling base plate is generally plate-shaped, with the left end of the upper surface being horizontal and the middle to the right end being a downward slope, and the junction of the horizontal surface and the slope being a rod bundle positioning groove; a support arm is vertically provided at the right end of the dismantling base plate, and a force adjusting block perpendicular to the support arm is also provided in the track; a limiting baffle plate is provided at the top of the support arm, and the right end of the support arm is movably connected to the limiting baffle plate; the left end of the limiting baffle plate is connected to the component separation lever plate through a rotating plate.

[0005] The support arm has a track on its left side, and a sliding tooth is provided on the inner side of the track. The force adjustment block moves up and down along the track and is fixed at any height by the sliding tooth.

[0006] The support arm is connected to the limiting plate via a hinge pin.

[0007] The component has two separation levers.

[0008] The component separation lever is in the shape of a "Y" branch.

[0009] A method for underwater dismantling of spent fuel rod bundles in a heavy water reactor, comprising the following steps:

[0010] Step S1: Place the underwater dismantling device for the spent fuel rod bundles of the heavy water reactor underwater;

[0011] Step S2: Place the spent fuel rod bundle into the rod bundle positioning slot using the rod bundle gripping tool;

[0012] Step S3: Adjust the height of the force adjustment block;

[0013] Step S4: Insert one branch of the component separation lever vertically between the rod bundle components;

[0014] Step S5: Push the spent fuel rod bundle down the slope until the limit baffle contacts the force adjustment block 10. Under the action of inertia, the rod bundle element stops moving instantly under the action of the element separation lever. Under the reaction action of the element separation lever, the resistance weld of the rod bundle element and the rod bundle end plate is detached, realizing the separation of the rod bundle element from the spent fuel rod bundle.

[0015] In step S3, after adjusting the force adjustment block, the angle between the limit baffle and the support arm is 30 degrees.

[0016] It also includes step S0: placing the monitor underwater so that the underwater dismantling process can be observed on shore via a display connected to the monitor.

[0017] The significant advantage of this invention lies in the fact that the underwater dismantling device and method for spent fuel rod bundles in heavy water reactors, as described in this invention, utilizes the inertial rolling of the spent fuel rod bundles to detach the rod bundle elements from the resistance welds on the rod bundle end plates under the action of the element separation levers, thus achieving non-destructive dismantling of the rod bundle elements. This device has a simple structure, reliable performance, and effectively solves the problem of non-destructive removal of rod bundle elements. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the underwater dismantling device for spent fuel rod bundles in a heavy water reactor according to the present invention.

[0019] In the diagram: 1. Rod bundle positioning groove; 2. Rod bundle end plate; 3. Resistance welding point; 4. Disassembly base plate; 5. Rod bundle component; 6. Component separation lever; 7. Rotating plate; 8. Limiting plate; 9. Hinge pin; 10. Force adjustment block; 11. Support arm. Detailed Implementation

[0020] The technical solutions of the invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without creative effort are within the scope of the invention.

[0021] In the description of this invention, it should be noted that the use of terms such as "above" to indicate orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating and simplifying the description. It does 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 invention.

[0022] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection," "setting," "installation," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] like Figure 1 As shown, an underwater dismantling device for spent fuel rod bundles of heavy water reactors includes a dismantling base plate 4, a component separation lever 6, a limiting baffle 8, a force adjustment block 10, and a support arm 11.

[0025] The disassembly base plate 4 has a plate-like structure. The upper surface is horizontal on the left and slopes downward from the middle to the right. The junction of the horizontal surface and the slope is a rod bundle positioning groove 1, which is an arc-shaped groove for placing the rod bundle assembly. The right end of the disassembly base plate 4 is vertically provided with a support arm 11. A track is provided on the left side of the support arm 11, and sliding teeth are provided on the inner side of the track. A force adjustment block 10 perpendicular to the support arm 11 is also provided in the track. The force adjustment block 10 moves up and down along the track and is fixed at any height by the sliding teeth. The top of the support arm 11 is connected to the right end of the limiting plate 8 through a hinge pin 9, so that the limiting plate 8 can rotate around the support arm 11 along the direction of the hinge pin 9. The left end of the limiting plate 8 is connected to the component separation lever 6 through a rotating piece 7. The component separation lever 6 is Y-shaped and branched. In one embodiment, there are two component separation levers 6.

[0026] The rod bundle element 5 is connected to the rod bundle end plate 2 via resistance welding point 3. The rod bundle element 5 consists of several rods, which are circumferentially distributed on the rod bundle end plate 2. In one embodiment, the rod bundle element 5 is radially distributed on the rod bundle end plate 2.

[0027] A method for underwater dismantling of spent fuel rod bundles in a heavy water reactor, comprising the following steps:

[0028] Step S0: Place the monitor underwater so that the underwater dismantling process can be observed from the shore via a display connected to the monitor;

[0029] Step S1: Place the underwater dismantling device for spent fuel rod bundles of heavy water reactor underwater so that the monitor can capture the entire working process of the device.

[0030] Step S2: Place the spent fuel rod bundle into the rod bundle positioning groove 1 using the rod bundle grasping tool;

[0031] Step S3: Adjust the height of the force adjustment block 10 so that the angle between the limit baffle 8 and the support arm 11 is 30 degrees;

[0032] Step S4: Insert one branch of the element separation lever 6 vertically between the rod bundle elements 5;

[0033] Step S5: Push the spent fuel rod bundle so that it rolls down the slope until the limit baffle 8 contacts the force adjustment block 10. Under the action of inertia, the rod bundle element 5 stops moving instantly under the action of the element separation lever 6. Under the reaction action of the element separation lever 6, the resistance weld point 3 between the rod bundle element 5 and the rod bundle end plate 2 is detached, realizing the separation of the rod bundle element 5 from the spent fuel rod bundle.

[0034] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An underwater dismantling device for spent fuel rod bundles from a heavy water reactor, characterized in that: The device includes a disassembly base plate (4), a component separation lever plate (6), a limiting baffle (8), a force adjustment block (10), and a support arm (11). The disassembly base plate (4) is a plate-shaped structure with a horizontal surface on the left end and a downward slope from the middle to the right end on the upper surface. The junction of the horizontal surface and the slope is a rod bundle positioning groove (1). The right end of the disassembly base plate (4) is vertically provided with a support arm (11). A track is provided on the left side of the support arm (11), and a force adjustment block (10) perpendicular to the support arm (11) is also provided in the track. The top of the support arm (11) is provided with a limiting baffle (8), and the right end of the support arm (11) is movably connected to the limiting baffle (8). The left end of the limiting baffle (8) is connected to the component separation lever plate (6) through a rotating plate (7).

2. The underwater dismantling device for spent fuel rod bundles in a heavy water reactor according to claim 1, characterized in that: The inner side of the track is provided with sliding teeth, and the force adjustment block (10) moves up and down along the track direction and is fixed at any height by the sliding teeth.

3. The underwater dismantling device for spent fuel rod bundles in a heavy water reactor according to claim 1, characterized in that: The support arm (11) is connected to the limiting plate (8) via a hinge pin (9).

4. The underwater dismantling device for spent fuel rod bundles in a heavy water reactor according to claim 1, characterized in that: The number of the component separation levers (6) is two.

5. The underwater dismantling device for spent fuel rod bundles of a heavy water reactor according to claim 1, characterized in that: The element separating lever plate (6) is in the shape of a "Y" branch.

6. A method for underwater dismantling of spent fuel rod bundles from a heavy water reactor, characterized in that: This method is implemented using the underwater dismantling device for spent fuel rod bundles from heavy water reactors as described in any one of claims 1-5, and includes the following steps: Step S1: Place the underwater dismantling device for the spent fuel rod bundles of the heavy water reactor underwater; Step S2: Place the spent fuel rod bundle into the rod bundle positioning groove (1) using the rod bundle grasping tool; Step S3: Adjust the height of the force adjustment block (10); Step S4: Insert one branch of the element separation lever (6) vertically between the rod bundle elements (5); Step S5: Push the spent fuel rod bundle down the slope until the limit baffle (8) contacts the force adjustment block (10). Under the action of inertia, the rod bundle element (5) stops moving instantly under the action of the element separation lever (6). Under the reaction action of the element separation lever (6), the resistance weld (3) between the rod bundle element (5) and the rod bundle end plate (2) is detached, realizing the separation of the rod bundle element (5) from the spent fuel rod bundle.

7. A method for underwater dismantling of spent fuel rod bundles from a heavy water reactor according to claim 6, characterized in that: In step S3, after adjusting the force adjustment block (10), the angle between the limit baffle (8) and the support arm (11) is 30 degrees.

8. A method for underwater dismantling of spent fuel rod bundles from a heavy water reactor according to claim 6, characterized in that: It also includes step S0: placing the monitor underwater so that the underwater dismantling process can be observed on shore via a display connected to the monitor.

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