A wide range area gamma ionization chamber detector

Abstract

The utility model discloses a wide range area gamma ionization chamber detector, including on -the -spot processing box and detection appearance, through the cable connection between on -the -spot processing box and detection appearance, and detection appearance includes base and detection unit, and the outside of detection unit is provided with the shielding cylinder, and the incombustible gas filling area is enclosed between base and shielding cylinder, and detection unit includes support plate, detection body and collecting electrode, and the bottom of support plate is provided with the radioactive source source holder, and the bottom of support plate still is provided with the inflation pipe, and the top of inflation pipe and the inside of incombustible gas filling area are communicated, the utility model discloses through the incombustible gas filling area that encloses between base and shielding cylinder, fills incombustible gas and forms the inflation ionization chamber detector, makes the signal of stronger of the same dose field, improves equipment stability, and the present detector can convert gamma ray into current signal output without electronic device, thereby realizes the detection of gamma ray in the environment of high temperature, high humidity, high pressure and high radiation dose.

Description

Technical Field

[0001] This invention belongs to the field of nuclear radiation detection technology, and in particular relates to a wide-range gamma ionization chamber detector. Background Technology

[0002] Wide-range ionization chamber gamma monitors are primarily used for monitoring gamma dose rates in complex environments such as spent fuel pools in nuclear power plants. When the gamma dose rate at a monitored location exceeds a threshold, the instrument provides alarm signals and analog outputs, ensuring the normal operation of process equipment and the safety of personnel. However, current nuclear power plants have added requirements for accident and post-accident environments in the relevant passages of the spent fuel pool area. These requirements mandate that equipment can operate normally in high-temperature and high-humidity environments (108°C, 100% humidity) during and after an accident. Existing ordinary low-pressure ionization chamber detectors cannot meet these requirements. Furthermore, the accident and post-accident environment in the spent fuel pool area requires detectors to have radiation resistance (1×10⁵ Gy), which existing ordinary low-pressure ionization chamber detectors cannot meet. Additionally, the connecting cables used in existing ordinary low-pressure ionization chamber detectors are organic cables, which will pulverize under high radiation doses, failing to meet the requirements for accident and post-accident environments. Utility Model Content

[0003] The technical problem to be solved by this utility model is to address the shortcomings of the prior art by providing a wide-range gamma ionization chamber detector. By forming an inert gas-filled area between the base and the shielding cylinder, and filling this area with inert gas to form a gas-filled ionization chamber detector, a stronger signal is generated at the same dose field, improving the stability of the equipment. Gamma rays can be detected without electronic components. This detector can convert gamma rays into current signals for output, thereby enabling gamma ray detection in environments with high temperature, high humidity, high pressure, and high radiation dose.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a wide range gamma ionization chamber detector, including an on-site processing box and a detector mounted on a detector frame and connected to the on-site processing box; the on-site processing box and the detector are connected by a cable;

[0005] The detector includes a base mounted on a detector frame and a detector unit mounted on the base. A shielding cylinder is provided on the outside of the detector unit. The shielding cylinder and the base are welded together, and an inert gas filling area is formed between the base and the shielding cylinder.

[0006] The detection unit includes a support plate horizontally disposed within the base, a detector disposed above the support plate and arranged within the shielding cylinder, and a collecting electrode vertically disposed within the detector body;

[0007] The bottom of the support plate is provided with a radiation source holder, which is arranged on one side of the support plate; the bottom of the support plate is also provided with an inflation pipe, the top of which is connected to the interior of the inert gas filling area.

[0008] Furthermore, the detector frame is provided with a bottom cover, and the base is arranged on the bottom cover. The bottom cover and the base are connected by a plurality of first bolts. Insulating gaskets are provided at the connection points between the first bolts and the bottom cover and the base. O-rings are provided at the connection points between the bottom cover and the base.

[0009] Furthermore, a connector plug for connecting to a cable is provided on the outer side of the base.

[0010] Furthermore, an insulating seat is provided between the support plate and the detector, the insulating seat is located in the middle of the support plate, the bottom of the collecting electrode is inserted into the insulating seat, and the bottom of the collecting electrode is connected to the insulating seat by a first bolt.

[0011] Furthermore, the support plate and the base are welded together; the support plate and the detector are connected by a plurality of second bolts, which are evenly distributed along the circumferential direction of the support plate; and an isolation sleeve is provided on the segment between the support plate and the detector where the second bolts are located.

[0012] Furthermore, the detector includes an electrode holder horizontally positioned above the support plate and a high-voltage electrode connected to the electrode holder, with the electrode holder and the high-voltage electrode connected by a third bolt; the central axis of the high-voltage electrode coincides with the central axis of the shielding cylinder, and the high-voltage electrode is coaxially arranged inside the shielding cylinder; the second bolt is arranged between the support plate and the electrode holder, the isolation sleeve is arranged between the support plate and the electrode holder, and the insulating seat is arranged between the support plate and the electrode holder.

[0013] Furthermore, the collecting electrode is vertically disposed in the middle of the electrode holder, and an insertion part is provided at the bottom of the collecting electrode. The axis of the insertion part coincides with the axis of the collecting electrode, and the insertion part and the collecting electrode are integrally formed. The insertion part is inserted into the insulating base, and the bottom of the insertion part is connected to the insulating base by a first bolt.

[0014] Furthermore, both the insulating base and the insulating pad are ceramic components.

[0015] Furthermore, the on-site processing box is equipped with a circuit board, which integrates a controller, a memory connected to the controller, and an alarm. The alarm is mounted on the detection frame, which is equipped with a handle.

[0016] The beneficial effects of this invention are that an inert gas-filled area is formed between the base and the shielding cylinder, and an inert gas is filled in this area to form an ionization chamber detector, which generates a stronger signal in the same dose field and improves the stability of the equipment; gamma rays can be detected without electronic devices, and this detector can convert gamma rays into current signals for output, thereby realizing the detection of gamma rays in environments with high temperature, high humidity, high pressure and high radiation dose.

[0017] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 This is a schematic diagram showing the connection relationship between the detection frame and the detector of this utility model.

[0020] Figure 3 This is a diagram showing the usage state of this utility model.

[0021] Figure 4 This is a circuit block diagram of the present invention.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1—On-site treatment box; 2—Cable; 3—Detection frame;

[0024] 4—Bottom cover; 5—Base; 6—Shielding cylinder;

[0025] 7—First bolt; 8—Insulating gasket; 9—O-ring seal;

[0026] 10—Connector plug; 11—Support plate; 12—Detector;

[0027] 13—Collector; 14—Second bolt; 15—Radioactive source holder;

[0028] 16—Inflation tube; 17—Isolation sleeve; 18—Electric pole base;

[0029] 19—High-voltage electrode cylinder; 20—Alarm device; 21—Insertion part;

[0030] 22—Insulating base; 23—Controller; 24—Wall;

[0031] 25—Memory; 26—Handle. Detailed Implementation

[0032] like Figures 1 to 4As shown, this utility model includes an on-site treatment box 1 and a detector mounted on a detection frame 3 and connected to the on-site treatment box 1; the on-site treatment box 1 and the detector are connected by a cable 2.

[0033] The detector includes a base 5 mounted on a detector frame 3 and a detector unit mounted on the base 5. A shielding cylinder 6 is provided on the outside of the detector unit. The shielding cylinder 6 and the base 5 are welded together, and an inert gas filling area is formed between the base 5 and the shielding cylinder 6.

[0034] The detection unit includes a support plate 11 horizontally disposed within the base 5, a detector 12 disposed above the support plate 11 and arranged within the shielding cylinder 6, and a collecting electrode 13 vertically disposed within the detector 12.

[0035] The bottom of the support plate 11 is provided with a radiation source holder 15, which is arranged on one side of the support plate 11; the bottom of the support plate 11 is also provided with an inflation pipe 16, the top of which is connected to the interior of the inert gas filling area.

[0036] In actual use, an inert gas-filled area is formed between the base 5 and the shielding cylinder 6. Inert gas is filled in this area to form an ionization chamber detector, which generates a stronger signal in the same dose field and improves the stability of the equipment. It can detect gamma rays without electronic devices. This detector can convert gamma rays into current signals for output, thereby realizing the detection of gamma rays in environments with high temperature, high humidity, high pressure and high radiation dose.

[0037] It should be noted that this detector is mainly used for gamma dose rate monitoring in complex environments of nuclear power plants. When the gamma dose rate at the monitoring location exceeds the threshold, the alarm 20 will issue an alarm signal to ensure the normal operation of process equipment and the safety of personnel. Cable 2 is an armored mineral cable. The detector is designed using a combination of a basic ionization chamber and a special-environment ionization chamber. To adapt to the high radiation dose rate environment under containment accident conditions, the ionization chamber volume is designed to be 1 liter, filled with 8-10 atmospheres of inert gas. The ionization chamber body is made of pure aluminum, and the outer shell is made of stainless steel. Cable 2 is an armored cable. The connection between the ionization chamber and the armored cable uses a dedicated sealed connector, ensuring the entire ionization chamber detector is completely sealed and can withstand harsh environmental impacts and operate normally. The detector has no internal circuitry and is a purely mechanical structure. A high voltage is provided to it by the local processing box 1, enabling it to respond to external gamma radiation and output corresponding dose rate information. The signal is transmitted to the local processing box 1 via the armored mineral cable for amplification, greatly enhancing the detector's radiation resistance and environmental adaptability.

[0038] Specifically, this detector requires an inert gas pressure of 8-10 atmospheres to be filled inside, and the overall sealing of the detector must be ensured to prevent gas leakage. The detector has a volume of 1L and uses armored mineral cables, enabling long-term operation in the harsh accident environments of nuclear power plants, including high temperature, high humidity, high pressure, and high radiation. Placing a radioactive source within the source holder 15 ensures that the detector operates under a stable background environment; the internal radioactive source provides a stable signal to prevent detector failure.

[0039] When this utility model is working, such as Figure 3 As shown, the detector frame 3 is installed on the wall 24 to install the detector for convenient subsequent detection. Gamma photons can penetrate the shielding cylinder 6. When there is gamma radiation, when a negative high voltage is applied to the collecting electrode 13, the ionized indoor air will be ionized by the high voltage, generating induced charges. The induced charges accumulate on the collecting electrode 13 to form an induced current. The detector responds to radiation and outputs a micro-current signal. The signal is transmitted to the local processing box 1 via a low-noise cable for processing to obtain a measurement value related to radioactivity. After calculation, a measurement value in the unit of measurement of the monitor that conforms to statistical error is obtained. Based on the magnitude of the measurement value, it is compared with the alarm threshold stored in the memory 25 to determine whether the radioactivity is in a high value, warning, or failure alarm state. If the alarm conditions are met, the corresponding alarm signal is given.

[0040] In this embodiment, the detector frame 3 is provided with a bottom cover 4, and the base 5 is arranged on the bottom cover 4. The bottom cover 4 and the base 5 are connected by a plurality of first bolts 7. Insulating pads 8 are provided at the connection points of the first bolts 7 with the bottom cover 4 and the base 5. O-rings 9 are provided at the connection points of the bottom cover 4 and the base 5.

[0041] like Figure 2 As shown, the first bolt 7 connects the bottom cover 4 and the base 5 into one piece, and the first bolt 7 connects the bottom cover 4 and the base 5 to the detection frame 3.

[0042] In this embodiment, a connector plug 10 for connecting to the cable 2 is provided on the outer side of the base 5.

[0043] In this embodiment, an insulating seat 22 is provided between the support plate 11 and the detector 12. The insulating seat 22 is arranged in the middle of the support plate 11. The bottom of the collecting electrode 13 is inserted into the insulating seat 22. The bottom of the collecting electrode 13 is connected to the insulating seat 22 by a first bolt 7.

[0044] In this embodiment, the support plate 11 and the base 5 are welded together; the support plate 11 and the detector 12 are connected by a plurality of second bolts 14, and the plurality of second bolts 14 are evenly distributed along the circumferential direction of the support plate 11; an isolation sleeve 17 is provided on the segment of the second bolt 14 between the support plate 11 and the detector 12.

[0045] In this embodiment, the detector 12 includes an electrode holder 18 horizontally disposed above the support plate 11 and a high-voltage electrode 19 connected to the electrode holder 18. The electrode holder 18 and the high-voltage electrode 19 are connected by a third bolt. The central axis of the high-voltage electrode 19 coincides with the central axis of the shielding cylinder 6, and the high-voltage electrode 19 is coaxially arranged inside the shielding cylinder 6. The second bolt 14 is arranged between the support plate 11 and the electrode holder 18, the isolation sleeve 17 is arranged between the support plate 11 and the electrode holder 18, and the insulating seat 22 is arranged between the support plate 11 and the electrode holder 18.

[0046] In this embodiment, the collecting electrode 13 is vertically arranged in the middle of the electrode holder 18, and the bottom of the collecting electrode 13 is provided with an insertion part 21. The axis of the insertion part 21 coincides with the axis of the collecting electrode 13, and the insertion part 21 and the collecting electrode 13 are integrally formed. The insertion part 21 is inserted into the insulating seat 22, and the bottom of the insertion part 21 is connected to the insulating seat 22 by a first bolt 7.

[0047] In this embodiment, both the insulating base 22 and the insulating pad 8 are ceramic parts.

[0048] In actual use, the support plate 11, the air inlet pipe 16 and the pole base 18 are all made of stainless steel. Stainless steel is used as a structural component and high-insulation ceramic is used as an insulating material. Furthermore, the base 5 and the shielding cylinder 6 are connected by argon arc welding, which gives the detector good sealing and strength, so that the entire detector can withstand the high temperature, high pressure and high radiation dose of the accident environment.

[0049] In this embodiment, the on-site treatment box 1 is equipped with a circuit board, on which a controller 23 and a memory 25 connected to the controller 23 and an alarm 20 are integrated. The alarm 20 is installed on the detection frame 3. The detection frame 3 is equipped with a handle 26.

[0050] In actual use, the local processing box 1 is also equipped with a low-voltage power supply, a high-voltage power supply, and an amplifier circuit.

[0051] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A wide-range γ-ionization chamber detector, characterized in that: It includes an on-site treatment box (1) and a detector mounted on a detector rack (3) and connected to the on-site treatment box (1); the on-site treatment box (1) and the detector are connected by a cable (2); The detector includes a base (5) set on the detector frame (3) and a detector unit set on the base (5). A shielding cylinder (6) is provided on the outside of the detector unit. The shielding cylinder (6) and the base (5) are welded together. An inert gas filling area is formed between the base (5) and the shielding cylinder (6). The detection unit includes a support plate (11) horizontally disposed in the base (5), a detector (12) disposed above the support plate (11) and arranged in the shielding cylinder (6), and a collection electrode (13) vertically disposed in the detector (12). The bottom of the support plate (11) is provided with a radiation source holder (15), which is arranged on one side of the support plate (11); the bottom of the support plate (11) is also provided with an inflation pipe (16), the top of which is connected to the interior of the inert gas filling area.

2. The wide-range γ-ionization chamber detector according to claim 1, characterized in that: The detector frame (3) is provided with a bottom cover (4), and the base (5) is arranged on the bottom cover (4). The bottom cover (4) and the base (5) are connected by a plurality of first bolts (7). Insulating pads (8) are provided at the connection points of the first bolts (7) with the bottom cover (4) and the base (5). O-rings (9) are provided at the connection points of the bottom cover (4) and the base (5).

3. The wide-range γ-ionization chamber detector according to claim 1, characterized in that: The outer side of the base (5) is provided with a connector plug (10) for connecting to the cable (2).

4. A wide-range γ-ionization chamber detector according to claim 1, characterized in that: An insulating seat (22) is provided between the support plate (11) and the detector (12). The insulating seat (22) is located in the middle of the support plate (11). The bottom of the collecting electrode (13) is inserted into the insulating seat (22). The bottom of the collecting electrode (13) is connected to the insulating seat (22) by a first bolt (7).

5. A wide-range γ-ionization chamber detector according to claim 4, characterized in that: The support plate (11) and the base (5) are welded together; the support plate (11) and the detector (12) are connected by a plurality of second bolts (14), and the plurality of second bolts (14) are evenly distributed along the circumferential direction of the support plate (11); the second bolts (14) are provided with isolation sleeves (17) on the segment between the support plate (11) and the detector (12).

6. A wide-range γ-ionization chamber detector according to claim 5, characterized in that: The detector (12) includes an electrode holder (18) horizontally disposed above the support plate (11) and a high-voltage electrode (19) connected to the electrode holder (18). The electrode holder (18) and the high-voltage electrode (19) are connected by a third bolt. The central axis of the high-voltage electrode (19) coincides with the central axis of the shielding cylinder (6). The high-voltage electrode (19) is coaxially arranged inside the shielding cylinder (6). The second bolt (14) is arranged between the support plate (11) and the electrode holder (18). The isolation sleeve (17) is arranged between the support plate (11) and the electrode holder (18). The insulating seat (22) is arranged between the support plate (11) and the electrode holder (18).

7. A wide-range γ-ionization chamber detector according to claim 6, characterized in that: The collecting electrode (13) is vertically arranged in the middle of the electrode holder (18). The bottom of the collecting electrode (13) is provided with an insertion part (21). The axis of the insertion part (21) coincides with the axis of the collecting electrode (13). The insertion part (21) and the collecting electrode (13) are integrally formed. The insertion part (21) is inserted into the insulating seat (22). The bottom of the insertion part (21) is connected to the insulating seat (22) by a first bolt (7).

8. A wide-range γ-ionization chamber detector according to claim 7, characterized in that: Both the insulating base (22) and the insulating pad (8) are ceramic parts.

9. A wide-range γ-ionization chamber detector according to claim 1, characterized in that: The on-site treatment box (1) is equipped with a circuit board, on which a controller (23) and a memory (25) connected to the controller (23) and an alarm (20) are integrated. The alarm (20) is installed on the detection frame (3). The detection frame (3) is equipped with a handle (26).

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