A radiation shielding test device for hot chamber shielding doors

Abstract

A radiation shielding test device for a hot room shielding door belongs to the technical field of nuclear radiation shielding test. The device comprises a fixed shielding body, an array neutron source, a translation hydraulic pressure, a mobile shielding device, a lifting hydraulic pressure, a lifting platform, a lifting base, a door frame, a door leaf, a round-shaped single substance boron crystal layer, a square single substance boron crystal material layer, a diffuse reflection material frame, a photomultiplier plate, an industrial control computer and a mobile shielding body. The array neutron source is vertically distributed in the fixed shielding body space, the translation hydraulic pressure is connected to the mobile shielding device, the door frame and the door leaf are arranged on the lifting platform, the diffuse reflection material frame serves as a radiation channel, and its two ends are respectively connected to the door frame and the photomultiplier plate, and the photomultiplier plate and the thermocouple are connected to the industrial control computer through an optical fiber. The invention can meet the radiation shielding test requirements of a hot room shielding door within a certain width and height range, and can accurately detect the neutron flux and gamma ray intensity transmitted at the door seam and the door leaf of the hot room shielding door.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear radiation shielding test, and relates to a radiation shielding test device, in particular to a radiation shielding test device for a hot chamber shielding door. Background Art

[0002] A nuclear power plant is called an atomic power plant. It is a system and equipment that converts nuclear energy released by nuclear fission into electrical energy. It is a high-energy, low-consumption power plant. Under the increasingly serious energy and environmental crisis, the advantages of nuclear power as a clean energy are self-evident. However, the dangerous characteristics of nuclear power determine that the amount of nuclear leakage should meet the requirements of safety radiation indicators. Therefore, the design and research of the hot chamber shielding door shielding test device is a key link in testing whether the shielding device meets the requirements. Existing radiation shielding test devices, such as a miniature nuclear radiation dose measurement device disclosed in the invention patent of Chinese patent application No. 201811110561.1, include a detector and a mobile terminal. The detector includes a photoelectric conversion sensor, a pre-small signal amplifier and a signal shaper. The photoelectric conversion sensor, the pre-small signal amplifier and the signal shaper are connected in sequence. A pulse counter is provided in the inner cavity of the mobile terminal. The output signal of the detector passes through the pre-small signal amplifier and the signal shaper in sequence, and then connects to the pulse counter, which can realize the radiation signal detection of places with possible radiation. However, this device is only suitable for detecting gamma rays and x-rays, but cannot detect neutron flux with stronger penetration ability and greater harm to the human body.

[0003] Therefore, how to accurately test the neutron flux and gamma ray intensity behind radiation shielding to reduce unnecessary harm caused by people entering radiation sites is a problem that needs to be solved. Summary of the invention

[0004] The purpose of the present invention is to address the shortcomings of existing radiation shielding test devices, such as being only suitable for detecting gamma rays and x-rays, and being unable to detect neutron fluxes with stronger penetrating power and greater harm to the human body. A radiation shielding test device for a hot chamber shielding door is proposed, which can detect neutron flux and gamma ray intensity, and reduce unnecessary damage caused by people entering radiation sites.

[0005] The technical solution of the present invention is: a radiation shielding test device for a hot chamber shielding door, comprising an industrial control computer; characterized in that: the radiation shielding test device for the hot chamber shielding door is composed of a fixed shielding body, an array neutron source, a translation hydraulic pressure, a mobile shielding device, a lifting hydraulic pressure, a lifting platform, a lifting base, a door frame, a door leaf, and a photomultiplier plate; the array neutron source is vertically distributed inside the fixed shielding body, a mobile shielding device is provided at the outlet of the fixed shielding body, a translation hydraulic pressure is provided on the side of the mobile shielding device, the translation hydraulic pressure is connected to the mobile shielding device, a lifting base is provided at the bottom of the mobile shielding device, and a lifting base is provided on the lifting base Hydraulic, a lifting platform is connected to the top of the lifting hydraulic system, the door frame and the door leaf are arranged on the lifting platform, a square elemental boron crystal layer is arranged in the door leaf, a round elemental boron crystal layer is arranged between the door leaf and the door frame, thermocouples are arranged on the round elemental boron crystal layer and the square elemental boron crystal layer, a photomultiplier plate is arranged on the outside of the square elemental boron crystal layer, a diffuse reflection material frame with a radiation channel structure is arranged between the photomultiplier plate and the square elemental boron crystal layer, one side of the diffuse reflection material frame is connected to the door frame, and the other side is connected to the photomultiplier plate, the photomultiplier plate and the thermocouple are connected to the industrial control computer through optical fiber.

[0006] The array neutron sources are vertically and equidistantly distributed in the fixed shielding space, and the shapes, sizes and irradiation energies of the array neutron sources are all equal.

[0007] The mobile shielding device consists of a mobile shielding body and a roller arranged at the bottom of the mobile shielding body. Four guide rods are arranged on the translation hydraulics. The guide rods are spirally connected to the mobile shielding body. The hydraulic rods in the translation hydraulics are tightly fitted with the mobile shielding body. The rollers are rotationally connected to the mobile shielding body through rollers.

[0008] The door frame and the door leaf are matched in a stepped shape, and both the door frame and the door leaf are threadedly connected to the lifting platform.

[0009] The zigzag boron crystal layer and the square boron crystal layer are respectively glued to the door gap and the door leaf through the boron crystals at the corner positions, and the thermocouples are distributed on the zigzag boron crystal layer and the square boron crystal layer through an interference fit array.

[0010] The diffuse reflection material frame is a U-shaped structure used for the radiation channel, and its two ends are respectively fixedly connected to the door frame and the photomultiplier plate.

[0011] The photomultiplier plate is composed of a cathode plate, a photoelectric medium layer, a collecting plate, and a photomultiplier part from left to right. The photoelectric medium layer is symmetrically arranged at the left and right ends of the diffuse reflection material frame to form a closed cavity. The cathode plate and the photomultiplier part are fixedly connected to the upper and lower ends of the diffuse reflection material frame, and the collecting plate is fixedly connected to the upper end of the photomultiplier part.

[0012] The lifting platform is provided with lifting hydraulics distributed in three arrays, and spirally supported by upgraded hydraulics, and the lifting hydraulics are fixedly connected to the lifting base.

[0013] The beneficial effects of the present invention are as follows: a radiation shielding test device for a hot chamber shielding door proposed by the present invention has a novel structure and a clear working principle. The device is composed of a fixed shielding body, an array neutron source, a translation hydraulic pressure, a mobile shielding device, a lifting hydraulic pressure, a lifting platform, a lifting base, a door frame, a door leaf, and a photomultiplier plate. The neutron source is distributed in an array, which can avoid the local effect of neutron flux caused by linear irradiation of a single neutron source. On the other hand, the area of ​​the neutron irradiation region can be increased or decreased according to actual needs. The neutron shielding body adopts a structure in which one side can be moved and lifted, and the other sides are fixed, which can effectively adapt to the radiation shielding test of hot chamber shielding doors within a certain size range, improve the efficiency of radiation shielding test, and reduce the test cost. The circular single substance boron crystal layer and the square single substance boron crystal layer with array distributed thermocouples are respectively glued to the door seam and the door leaf of the hot chamber shielding door. By using the thermal analysis method, the neutron flux transmitted at the door seam and the door leaf of the hot chamber shielding door can be effectively measured by an industrial control computer. By using the photoelectric effect, the light signal is taken out as an electrical signal after being electron multiplied. In combination with the industrial control computer, the gamma ray intensity can be effectively measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the explosion structure of the device of the present invention.

[0015] Figure 2 It is an overall schematic diagram of the device of the present invention.

[0016] Figure 3 It is a schematic diagram of the structure of the door frame, door leaf and movable shielding body in the present invention.

[0017] Figure 4 It is a schematic diagram of the structure of the lifting device in the present invention.

[0018] Figure 5 It is a schematic diagram of the thermocouple distribution structure in the present invention.

[0019] Figure 6 Schematic diagram of the structure of the photomultiplier plate in the present invention.

[0020] In the figure: fixed shielding body 1, array neutron source 2, translation hydraulics 3, mobile shielding device 4, lifting hydraulics 5, lifting platform 6, lifting base 7, door frame 8, door leaf 9, circular elemental boron crystal layer 10, square elemental boron crystal layer 11, diffuse reflection material frame 12, photomultiplier plate 13, industrial control computer 14, thermocouple 15, mobile shielding body 41, roller 42, cathode plate 131, photoelectric medium layer 132, collecting plate 133, photomultiplier unit 134. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings:

[0022] like Figure 1 and Figure 2 As shown, the array neutron sources 2 are vertically and equidistantly distributed in the space of the fixed shielding body 1, and the shapes, sizes and irradiation energies of the array neutron sources 2 are equal. The purpose of this is to make the nuclear reactor source strength equivalent to the sum of the source strengths of the neutron sources in the array, which can avoid the local effect of neutron flux caused by linear irradiation of a single neutron source, and can also increase or decrease the area of ​​neutron irradiation according to actual needs. The diffuse reflection material frame 12 is used for the radiation channel, and its two ends are respectively fixed to the door frame 8 and the photomultiplier plate 13. The diffuse reflection material frame can prevent gamma rays from penetrating the radiation channel and improve the accuracy of gamma ray intensity detection.

[0023] like Figure 1 and Figure 3 As shown, the four guide rods in the translation hydraulic 3 are spirally connected to the mobile shielding body 41 in the mobile shielding device 4, the hydraulic rod in the translation hydraulic 3 is tightly fitted with the mobile shielding body 41 in the mobile shielding device 4, and the roller 42 in the mobile shielding device 4 is rotationally connected to the mobile shielding body 41 through a roller. When the width of the door frame 8 and the door leaf 9 is small when they are matched, the translation hydraulic 3 will cause the mobile shielding body 41 to shrink inward through the telescopic movement of the hydraulic rod and the rotation of the roller 42. When the width of the door frame 8 and the door leaf 9 is large when they are matched, the translation hydraulic 3 will cause the mobile shielding body 41 to expand outward through the telescopic movement of the hydraulic rod and the rotation of the roller 42, so that the radiation shielding test device can adapt to the radiation shielding test of hot chamber shielding doors within a certain width range.

[0024] like Figure 3 and Figure 4 As shown, the door frame 8 and the door leaf 9 that are matched in a stepped shape are threadedly connected to the lifting platform 6. The lifting platform 6 is spirally supported by three array-distributed lifting hydraulics 5. The lifting hydraulics 5 are fixedly connected to the lifting base 7. When the height of the door frame 8 and the door leaf 9 is relatively low when matched, the array-distributed lifting hydraulics 5 synchronously raise the lifting platform 6. When the height of the door frame 8 and the door leaf 9 is relatively high when matched, the array-distributed lifting hydraulics 5 synchronously lower the lifting platform 6. This enables the radiation shielding test device to adapt to the radiation shielding test of hot chamber shielding doors within a certain height range.

[0025] like Figure 5As shown, the zigzag boron crystal layer 10 and the square boron crystal material 11 are respectively glued to the door seam and the door leaf 9 through the corner position crystals, and the thermocouples 15 are distributed on the zigzag boron crystal layer 10 and the square boron crystal layer 11 through the interference fit array. The temperature of the boron crystal at the door seam and the door leaf before and after irradiation is calibrated by the thermocouples using the thermal analysis method. The heat calculation formula ΔQ=c·m·ΔT can be used to calculate the heat change of the boron crystal at the door seam and the door leaf before and after irradiation. In the formula, ΔQ is the heat difference of the boron crystal before and after irradiation, in J / g; c is the specific heat capacity of the boron crystal, in J / (g·℃); m is the mass of the boron crystal used, in g; ΔT is the temperature difference of the boron crystal before and after irradiation, in ℃; the relationship formula between the heat change value and the neutron flux is used. In combination with the industrial control computer 14, the neutron flux of the elemental boron crystal at the door gap and the door leaf before and after irradiation can be accurately calculated. In the formula, ΔQ is the heat difference of the elemental boron crystal before and after irradiation, in J / g; k is the proportionality coefficient; σ is the thermal neutron flux of the elemental boron crystal. 10 B is the differential cross section for nuclear reaction, in cm 2 ; is the neutron flux of the boron crystal per unit time per unit differential cross section, in units of n / (cm 2 ·s); t is the irradiation time, unit is s.

[0026] like Figure 6 As shown, the photomultiplier plate 13 is connected to the industrial control computer 14 through an optical fiber. The photomultiplier plate 13 is composed of a diffuse reflection material frame 12, a cathode plate 131, a photoelectric medium layer 132, a collecting plate 133 and a photomultiplier part 134. The diffuse reflection material frame 12 is in the shape of a U-shaped structure. The photoelectric medium layer 132 is symmetrically distributed at the left and right ends of the U-shaped structure to form a closed cavity. The cathode plate 131 and the photomultiplier part 134 are fixedly connected to the upper and lower ends of the diffuse reflection material frame 12. The collecting plate 133 is connected to the upper and lower ends of the diffuse reflection material frame 12. 33 is fixedly connected to the upper end of the photomultiplier section 134. When the gamma rays are incident on the photoelectric medium layer 132 through the diffuse reflection material frame 12, the electrons in the photoelectric medium layer 132 are excited, and the formed photoelectrons are released into the internal space of the vacuum (external photoelectric effect). Thereafter, under the action of the cathode plate 131 and the collecting plate 133, the photoelectrons are accelerated and focused to the collecting plate 133, and are multiplied by the electron multiplier section 134 and taken out from the collecting plate 133 as an electrical signal, so as to effectively measure the gamma ray radiation intensity.

Claims

1. A radiation shielding test device for a hot chamber shielding door, comprising an industrial control computer (14); characterized in that: The radiation shielding test device for the hot chamber shielding door comprises a fixed shielding body (1), an array neutron source (2), a translation hydraulic pressure (3), a mobile shielding device (4), a lifting hydraulic pressure (5), a lifting platform (6), a lifting base (7), a door frame (8), a door leaf (9), and a photomultiplier plate (13); the array neutron source (2) is vertically distributed inside the fixed shielding body (1); a mobile shielding device (4) is provided at the outlet of the fixed shielding body (1); a translation hydraulic pressure (3) is provided on the side of the mobile shielding device (4); the translation hydraulic pressure (3) is connected to the mobile shielding device (4); a lifting base (7) is provided at the bottom of the mobile shielding device (4); a lifting hydraulic pressure (5) is provided on the lifting base; a lifting platform (6) is connected to the top of the lifting hydraulic pressure (5); the door frame (8) is provided with a plurality of lifting devices; and ) and a door leaf (9) are arranged on a lifting platform (6), a square elemental boron crystal layer (11) is arranged inside the door leaf (9), a round elemental boron crystal layer (10) is arranged between the door leaf (9) and the door frame (8), thermocouples (15) are arranged on the round elemental boron crystal layer (10) and the square elemental boron crystal layer (11), a photomultiplier plate (13) is arranged outside the square elemental boron crystal layer (11), a diffuse reflection material frame (12) with a radiation channel structure is arranged between the photomultiplier plate (13) and the square elemental boron crystal layer (11), one side of the diffuse reflection material frame (12) is connected to the door frame (8), and the other side is connected to the photomultiplier plate (13), and the photomultiplier plate (13) and the thermocouple (15) are connected to the industrial control computer (14) through optical fibers; The array neutron sources (2) are vertically and equidistantly distributed in the space of the fixed shielding body (1), and the shapes, sizes and irradiation energies of the array neutron sources (2) are all equal; The meander-shaped elemental boron crystal layer (10) and the square elemental boron crystal layer (11) are respectively glued to the door gap and the door leaf (9) through elemental boron crystals at the corner positions, and the thermocouples (15) are distributed on the meander-shaped elemental boron crystal layer (10) and the square elemental boron crystal layer (11) through an interference fit array.

2. A thermal chamber shielding door radiation shielding test device according to claim 1, characterized in that: The mobile shielding device (4) is composed of a mobile shielding body (41) and a roller (42) arranged at the bottom of the mobile shielding body (41); four guide rods are arranged on the translation hydraulic system (3); the guide rods are spirally connected to the mobile shielding body (41); the hydraulic rods in the translation hydraulic system (3) are tightly fitted to the mobile shielding body (41); and the roller (42) is rotationally connected to the mobile shielding body (41) via a roller shaft.

3. A thermal chamber shielding door radiation shielding test device according to claim 1, characterized in that: The door frame (8) and the door leaf (9) are matched in a stepped manner, and both the door frame (8) and the door leaf (9) are threadedly connected to the lifting platform (6).

4. A thermal chamber shielding door radiation shielding test device according to claim 1, characterized in that: The diffuse reflection material frame (12) is a U-shaped structure used for a radiation channel, and its two ends are respectively fixedly connected to the door frame (8) and the photomultiplier plate (13).

5. The radiation shielding test device for a hot chamber shielding door according to claim 1, characterized in that: The photomultiplier plate (13) is composed of a cathode plate (131), a photoelectric medium layer (132), a collecting plate (133), and a photomultiplier part (134) from left to right. The photoelectric medium layer (132) is symmetrically arranged at the left and right ends of the diffuse reflection material frame (12) to form a closed cavity. The cathode plate (131) and the photomultiplier part (134) are fixedly connected to the upper and lower ends of the diffuse reflection material frame (12), and the collecting plate (133) is fixedly connected to the upper end of the photomultiplier part (134).

6. The radiation shielding test device for a thermal chamber shielding door according to claim 1, characterized in that: The lifting platform (6) is provided with lifting hydraulics (5) distributed in three arrays, and spirally supported by the lifting hydraulics (5), and the lifting hydraulics (5) are fixedly connected to the lifting base (7).

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