A double-layer storage well device for storing product cups containing radioactive substances

Abstract

The present invention belongs to the technical field of nuclear waste treatment, and particularly relates to a double-layer storage well device for storing product cups containing radioactive substances. The double-layer storage well device (18) has a straight cylindrical shape and is vertically arranged in a storage chamber for storing product cups (6). It includes an inner cylinder (1) for accommodating the product cups (6) and an outer cylinder (2) sleeved around the outer periphery of the inner cylinder (1). A spiral gas flow channel for heat dissipation is provided between the inner cylinder (1) and the outer cylinder (2). The product cup (6) is a vitrified body for storing radioactive substances. The present invention uses the means of continuously changing the direction of the fluid in the spiral gas flow channel, thereby causing secondary circulation in the cross-section to strengthen heat transfer. It can effectively dissipate the heat generated by the decay of the product cup (6) through convective heat transfer, and can effectively reduce the heat conducted to the concrete wall of the storage chamber through radiative heat transfer, so as to ensure that the concrete temperature meets the design requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear waste treatment, and in particular relates to a double-layer storage well device for storing radioactive material product cups. Background Art

[0002] In the post-processing process of nuclear waste, the radioactive material storage facilities of the post-processing plant usually adopt natural ventilation or forced ventilation. The development of its ventilation and cooling system is of great significance for the safe and reliable storage and subsequent disposal of radioactive materials. Vitrification is an effective way to seal radioactive materials. Since radioactive materials release heat during decay, the glass solidification body needs to rely on the ventilation system to continuously discharge the heat generated during the storage process, so as to implement efficient and sufficient cooling. The design of the ventilation and cooling system needs to focus on two aspects: first, it is necessary to ensure the integrity of the storage container to prevent damage caused by local overheating; at the same time, it is also necessary to avoid the structural strength of the concrete walls of the storage room being affected by excessive temperature.

[0003] The glass solidified body (product cup container) used to store radioactive materials in the radioactive material storage facility of the reprocessing plant transfers the heat generated by the decay of the radioactive materials to the concrete wall of the storage facility through natural convection, thermal radiation and other means. The usual storage well is set as a single-layer cylindrical tube without openings, or a single-layer cylindrical tube with rectangular holes. Due to the high surface temperature of the product cup container and the poor ventilation and cooling system, the temperature of the concrete structure exceeds the standard. Summary of the invention

[0004] The purpose of the present invention is to provide a storage well device for enhancing the ventilation and cooling effect of a radioactive material storage facility. The storage well device can effectively conduct heat generated by decay of a product cup through convection heat transfer. At the same time, it can effectively reduce the heat conducted to the concrete wall of the storage room through radiation heat transfer, thereby ensuring that the concrete temperature meets the design requirements.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is a double-layer storage well device for a product cup of radioactive material. The double-layer storage well device has a straight cylindrical shape and is vertically arranged in a storage chamber for storing the product cup. It includes an inner cylinder for accommodating the product cup and an outer cylinder arranged on the outer periphery of the inner cylinder. A spiral gas flow channel for heat dissipation is provided between the inner cylinder and the outer cylinder. The product cup is a glass solidified body for storing radioactive material.

[0006] Furthermore, a spiral guide plate is wound around the outer surface of the inner cylinder, the outer surface of the inner cylinder, the inner surface of the outer cylinder and the spiral guide plate together constitute the spiral gas flow channel, and the spiral guide plate is connected to the inner cylinder and the outer cylinder by welding.

[0007] Furthermore, a plurality of ventilation holes are arranged on the wall of the inner tube, and the number of the ventilation holes gradually increases from the bottom to the top of the inner tube; at the top of the inner tube, the ventilation holes are evenly arranged in a 360-degree circumferential direction.

[0008] Furthermore, the top end of the inner tube and the top end of the outer tube are sealed and connected together by a sealing plug made of heat-insulating material to form the top end of the double-layer storage well device. The opening at the top end of the inner tube serves as a top vent of the double-layer storage well device. A through hole corresponding to the top vent is provided on the concrete ceiling of the storage room. The top vent is arranged in the concrete ceiling of the storage room through the through hole. The top end of the inner tube and the top end of the outer tube are isolated from the concrete ceiling by the sealing plug made of heat-insulating material.

[0009] Furthermore, the bottom ends of the inner cylinder and the outer cylinder are arranged on a bottom support seat, and the bottom support seat is an annular structure provided with a support column, and the inner cylinder and the outer cylinder are fixed by the bottom support seat to constitute the bottom end of the double-layer storage well device, and the opening at the bottom end of the inner cylinder and the hollow part of the bottom support seat together serve as the bottom vent of the double-layer storage well device, and the bottom support seat is also used to support the product cup stored in the inner cylinder through the support column; the lower surface of the bottom support seat is arranged on the concrete floor of the storage room, and the concrete floor is provided with a through hole corresponding to the bottom vent for airflow to enter the interior of the inner cylinder.

[0010] Furthermore, a gap of 10 mm to 20 mm is maintained between the inner surface of the inner cylinder and the cup body of the product cup, and a gap of 100 mm to 200 mm is maintained between the inner surface of the inner cylinder and the cup body of the product cup.

[0011] Furthermore, the thermal insulation material sealing plug is made of expanded perlite products.

[0012] Furthermore, the inner cylinder, the outer cylinder, the spiral guide plate and the bottom support seat are made of stainless steel, the wall thickness of the inner cylinder is 5-10 mm, and the wall thickness of the outer cylinder is 2-5 mm.

[0013] The beneficial effects of the present invention are:

[0014] 1. Support operation under mechanical ventilation and natural ventilation conditions;

[0015] 2. The heat exchange is enhanced by using the means of continuously changing the direction of the fluid in the spiral gas flow channel formed by the inner tube 1, the outer tube 2 and the spiral guide plate 3, thereby causing secondary circulation on the cross section, and the heat generated by the decay of the product cup 6 can be effectively removed through convection heat transfer; at the same time, the heat conducted to the concrete wall of the storage room through radiation heat transfer can be effectively reduced, thereby ensuring that the concrete temperature meets the design requirements;

[0016] 3. The air flowing upward in the spiral gas flow channel enters the flow area between the product cup 6 and the inner tube 1 of the wellbore through the ventilation holes 4 on the inner tube 1, thereby increasing its turbulence. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a double-layer storage well device for a product cup of radioactive material according to a specific embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of the inner cylinder 1 described in a specific embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of the outer surface of the inner cylinder 1 described in a specific embodiment of the present invention;

[0020] Figure 4 is a schematic diagram of the outer cylinder 2 described in a specific embodiment of the present invention;

[0021] Figure 5 yes Figure 4 A-direction view (top view of the heat insulation material sealing plug 5);

[0022] Figure 6 is a schematic diagram of the bottom support seat 7 described in a specific embodiment of the present invention;

[0023] Figure 7 It is a schematic diagram of a double-layer storage well device for a product cup of radioactive material according to a specific embodiment of the present invention arranged in a storage chamber;

[0024] In the figure: 1-inner cylinder, 2-outer cylinder, 3-spiral guide vane, 4-ventilation hole, 5-insulation material sealing plug, 6-product cup, 7-bottom support seat, 8-top vent, 9-bottom vent, 10-concrete ceiling, 11-concrete floor, 12-support column, 13-storage room ventilation inlet, 14-storage room bottom air duct, 15-storage room top air duct, 16-storage room concrete side wall, 17-storage hall floor, 18-double-layer storage well device. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] The present invention provides a double-layer storage well device for a product cup of radioactive material (see Figure 1 ), wherein the double-layer storage well device 18 is in the shape of a straight cylinder, which is vertically arranged in a storage chamber for storing a product cup 6, and comprises an inner cylinder 1 for fixing and accommodating the product cup 6 and an outer cylinder 2 which is sleeved on the outer periphery of the inner cylinder 1, the outer cylinder 2 is used for air conduction and shielding heat radiation, and a spiral gas flow channel for heat dissipation is provided between the inner cylinder 1 and the outer cylinder 2, and the product cup 6 is a glass solid body for storing radioactive substances.

[0027] like Figure 2 , Figure 3 As shown, a spiral guide vane 3 is wound around the outer surface of the inner cylinder 1, and the outer surface of the inner cylinder 1, the inner surface of the outer cylinder 2 and the spiral guide vane 3 together constitute a spiral gas flow channel. The spiral guide vane 3 is connected to the inner cylinder 1 and the outer cylinder 2 by welding.

[0028] A plurality of ventilation holes 4 are arranged on the wall of the inner tube 1, and the number of the ventilation holes 4 gradually increases from the bottom end to the top end of the inner tube 1; at the top end of the inner tube 1, the ventilation holes 4 are evenly arranged in a 360-degree circumferential direction.

[0029] like Figure 4 , Figure 5 As shown, the top end of the inner tube 1 and the top end of the outer tube 2 are sealed together by a heat-insulating material sealing plug 5 to form the top end of a double-layer storage well device 18. The opening at the top end of the inner tube 1 serves as the top vent 8 of the double-layer storage well device 18. A through hole corresponding to the top vent 8 is provided on the concrete ceiling 10 of the storage room. The top vent 8 is arranged (fixed) in the concrete ceiling 10 of the storage room through the through hole; the top end of the inner tube 1 and the top end of the outer tube 2 are isolated from the concrete ceiling 10 by a heat-insulating material sealing plug 5.

[0030] The bottom ends of the inner tube 1 and the outer tube 2 are arranged on a bottom support seat 7. The bottom support seat 7 (see Figure 6 ) is an annular structure with support columns 12, the inner cylinder 1 and the outer cylinder 2 are fixed by a bottom support seat 7, forming the bottom end of a double-layer storage well device 18, the opening at the bottom end of the inner cylinder 1 and the hollow part of the bottom support seat 7 together serve as the bottom vent 9 of the double-layer storage well device 18, the bottom support seat 7 is also used to support the product cup 6 stored inside the inner cylinder 1 through the support columns 12; the lower surface of the bottom support seat 7 is set on the concrete floor 11 of the storage room, and the concrete floor 11 is provided with a through hole corresponding to the bottom vent 9 for airflow to enter the inner cylinder 1.

[0031] A gap of 10 mm to 20 mm is maintained between the inner surface of the inner cylinder 1 and the cup body of the product cup 6, and a gap of 100 mm to 200 mm is maintained between the inner cylinder 1 and the outer cylinder 2.

[0032] The insulating material sealing plug 5 is made of expanded perlite products; the allowable use temperature of the expanded perlite products is higher than the maximum temperature of the outer surface of the product cup 6, and the expanded perlite products have low density and low thermal conductivity, and can be well combined with concrete.

[0033] The inner tube 1, the outer tube 2, the spiral guide vane 3 and the bottom support seat 7 are made of stainless steel. The wall thickness of the inner tube 1 is 5-10 mm, and the wall thickness of the outer tube 2 is 2-5 mm.

[0034] Finally, the specific application of the present invention is described in further detail.

[0035] like Figure 7 As shown, the double-layer storage well device 18 (hereinafter referred to as "well") for the product cup of radioactive material provided by the present invention is arranged in the storage room, and the storage room is arranged below the floor 17 of the storage hall. The wind from the fan enters the storage room descending ventilation channel from the storage room ventilation inlet 13 and reaches the bottom air duct 14 of the storage room, and enters the bottom vent 9 of the well through the through hole on the storage room bottom plate 11 (concrete). A part of the cooling wind flows upward along the gap between the product cup 6 and the inner tube 1 of the well, taking away the heat generated by the product cup 6. At the same time, another part of the cooling wind flows upward through the spiral gas flow channel between the inner tube 1 and the outer tube 2 of the well. During the circulation process, the cooling wind generates secondary circulation under the action of the spiral guide vane 3 to enhance heat exchange. The air flowing upward from the gap between the product cup 6 and the inner tube 1 of the well flows directly from the top vent 8 at the top of the well to the top air duct 15 of the storage room. The air flowing upward from the spiral gas flow channel between the inner tube 1 and the outer tube 2 of the wellbore enters the flow area between the product cup 6 and the inner tube 1 of the wellbore through the ventilation holes 4 on the inner tube 1 while flowing upward, thereby increasing its turbulence. When the air flowing upward from the spiral gas flow channel between the inner tube 1 and the outer tube 2 of the wellbore reaches the top of the wellbore, it cannot flow directly to the air duct 15 at the top of the storage chamber due to the presence of the heat insulation material sealing plug 5, and needs to enter the air duct 15 at the top of the storage chamber through the large number of ventilation holes 4 arranged circumferentially at the top of the inner tube 1. The cooling air entering the air duct 15 at the top of the storage chamber enters the external environment through the exhaust fan room or the exhaust chimney.

[0036] The device described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. A double-layer storage well device for storing product cups containing radioactive substances, Characterized in that: The double-layer storage well device (18) has a straight cylindrical shape and is vertically arranged in a storage chamber for storing product cups (6). It includes an inner cylinder (1) for accommodating the product cups (6) and an outer cylinder (2) sleeved around the periphery of the inner cylinder (1). A spiral gas flow channel for heat dissipation is provided between the inner cylinder (1) and the outer cylinder (2). The product cups (6) are glass solidified bodies for storing radioactive substances; A spiral guide vane (3) is wound around the outer surface of the inner cylinder (1). The outer surface of the inner cylinder (1), the inner surface of the outer cylinder (2), and the spiral guide vane (3) together form the spiral gas flow channel. The spiral guide vane (3) is connected to the inner cylinder (1) and the outer cylinder (2) by welding; A number of ventilation holes (4) are provided on the wall of the inner cylinder (1). From the bottom end to the top end of the inner cylinder (1), the number of ventilation holes (4) gradually increases; at the top end of the inner cylinder (1), the ventilation holes (4) are evenly arranged circumferentially at 360 degrees; The top ends of the inner cylinder (1) and the outer cylinder (2) are hermetically connected together by a heat-insulating material sealing plug (5) to form the top end of the double-layer storage well device (18). The opening at the top end of the inner cylinder (1) serves as the top ventilation opening (8) of the double-layer storage well device (18). A through hole corresponding to the top ventilation opening (8) is provided on the concrete ceiling (10) of the storage chamber. The top ventilation opening (8) is arranged in the concrete ceiling (10) of the storage chamber through the through hole; the top ends of the inner cylinder (1) and the outer cylinder (2) are isolated from the concrete ceiling (10) by the heat-insulating material sealing plug (5); The bottom ends of the inner cylinder (1) and the outer cylinder (2) are arranged on a bottom support base (7). The bottom support base (7) is an annular structure provided with support columns (12). The inner cylinder (1) and the outer cylinder (2) are fixed by the bottom support base (7) to form the bottom end of the double-layer storage well device (18). The opening at the bottom end of the inner cylinder (1) and the hollow part of the bottom support base (7) together serve as the bottom ventilation opening (9) of the double-layer storage well device (18). The bottom support base (7) is also used to support the product cups (6) stored inside the inner cylinder (1) through the support columns (12); the lower surface of the bottom support base (7) is arranged on the concrete floor (11) of the storage chamber. A through hole corresponding to the bottom ventilation opening (9) is provided on the concrete floor (11) for air flow to enter the inside of the inner cylinder (1).

2. The double-layer storage well device for storing product cups containing radioactive substances according to claim 1, Characterized in that: A gap of 10 mm - 20 mm is maintained between the inner surface of the inner cylinder (1) and the cup body of the product cup (6), and the gap between the inner cylinder (1) and the outer cylinder (2) is 100 - 200 mm.

3. The double-layer storage well device for storing product cups of radioactive substances according to claim 1, characterized in that: the heat-insulating material sealing plug (5) is made of expanded perlite products.

4. The double-layer storage well device for storing product cups of radioactive substances according to claim 1, characterized in that: the inner cylinder (1), the outer cylinder (2), the spiral guide vane (3) and the bottom support seat (7) are made of stainless steel, the wall thickness of the inner cylinder (1) is 5-10 mm, and the wall thickness of the outer cylinder (2) is 2-5 mm.

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