Uranium mine surface radon exhalation rate ex-situ measurement device and measurement method

Abstract

The invention discloses a uranium mine surface radon exhalation rate ex-situ measurement device and a measurement method, the uranium mine surface radon exhalation rate ex-situ measurement device comprises a gas collection hood and a gas extraction piece, a closed-up gas collection channel is arranged above the gas collection hood, the surface of the gas collection channel is provided with two symmetrically arranged connecting pipes, the bottom of the gas extraction piece is provided with insertion holes corresponding to the connecting pipes, and the insertion holes are communicated with the gas collection hood. The air extracting piece is connected with the air collecting channel at the inserting hole through connecting pipes, an air pump is arranged at the end of one connecting pipe, an output pipe extending outwards is arranged on the surface of the air extracting piece, an annular clamping support is arranged in the air collecting channel, a steel wire cage frame is supported above the annular clamping support, and a drying agent is arranged in the steel wire cage frame; the uranium mine surface radon exhalation rate ex-situ measurement device can effectively collect, transfer and precipitate radon gas, is not limited by gas collection positions and environments during measurement, avoids radiation hidden dangers, can efficiently and accurately measure, provides technical support for ecological restoration, and is suitable for popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological restoration, and in particular to an ex-situ measuring device and method for measuring radon exhalation rate on the surface of a uranium mine. Background Art

[0002] Radon is a naturally occurring radioactive gas primarily derived from rocks or soil containing elements such as uranium and radium. During mining, rock formation damage can release radon into the air, soil, or water, causing radiation contamination. Therefore, monitoring radon emission rates is necessary during mine reclamation or remediation efforts. This helps assess the radiation risk level in the mining area, allowing for the evaluation of uranium mine decommissioning effectiveness and the implementation of other measures to ensure ecological restoration meets environmental standards.

[0003] Currently, uranium mine radon emission rates are typically measured using the accumulation method according to standard EJ / T979-95. After radon gas accumulates within a radon hood for a certain period of time, a radon detector is connected to measure the radon concentration within the hood. However, existing measurement devices are limited in use, and measurements are typically performed at the site of radon emission. The long wait times can cause discomfort, and the measurements are inefficient and can result in significant data errors.

[0004] Therefore, there is an urgent need for a measuring device and method that can efficiently collect gas for off-site measurement and has high measurement efficiency and small error. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and provide a uranium mine surface radon exhalation rate ex situ measurement device and method that can effectively collect and transfer precipitated radon gas, is not restricted by the gas collection location and environment during measurement, avoids radiation hazards, and provides technical support for ecological restoration.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is: an ex situ measurement device for the radon exhalation rate on the surface of a uranium mine, comprising a gas collecting hood and a gas extraction component, a gas collecting channel with a closed end is provided above the gas collecting hood, two symmetrically arranged connecting pipes are provided on the surface of the gas collecting channel, a socket corresponding to the connecting pipe is provided at the bottom of the gas extraction component, the gas extraction component is connected to the gas collecting channel at the socket through the connecting pipe, an air pump is provided at the end of one of the connecting pipes, and an output pipe extending outward is provided on the surface of the gas extraction component.

[0007] Preferably, an annular tray is provided inside the gas collecting channel, a wire cage is supported above the annular tray, and a desiccant is provided inside the wire cage.

[0008] Preferably, one end of the output tube is connected to the air extraction component, and the other end is connected to the radon detector, and a valve is further provided on the output tube.

[0009] Preferably, the connecting tube is fixed on the surface of the gas collecting channel and closed at the upper end. The inner wall of the socket on the bottom surface of the exhaust component is provided with a flexible silicone layer. Under normal circumstances, the socket is self-sealed by the flexible silicone layer. After the connecting tube is inserted into the flexible silicone layer, the gas collecting hood is connected to the exhaust component.

[0010] Preferably, a sealing ring is provided on the circumference of the bottom end of the gas collecting hood.

[0011] Preferably, a thermometer and hygrometer is provided on the outer wall of the gas collecting channel.

[0012] A method for measuring radon exhalation rate on the surface of a uranium mine using an ex situ measuring device comprises the following steps:

[0013] S1: After the surface area of ​​the uranium ore to be tested is smoothed, the gas collecting hoods are distributed at multiple points and buckled on the surface so that the sealing ring at the bottom of the gas collecting hood fits the surface of the medium. The volume inside the gas collecting hood is V1, and the bottom area of ​​the gas collecting hood is S.

[0014] S2: After T1 time, radon gas overflows, and the radon gas concentration inside the gas collection hood is C1. Then the gas extraction component is connected to the gas collection hood;

[0015] S3: Start the air pump at the bottom of the connecting pipe in the gas collection channel to mix the radon gas inside the gas collection cover with the gas inside the exhaust component. After the mixture is evenly mixed, the exhaust component is separated. At this time, the exhaust component forms a closed space with a volume of V2, and the radon gas concentration inside the exhaust component is C2.

[0016] S4: Connect the output tube on the surface of the exhaust component to the air inlet and return port of the radon detector and then turn on the radon detector. The measuring time is T2, the measured radon concentration is C3, and the volume of the radon detection chamber inside the radon detector is V3;

[0017] The formula for calculating radon exhalation rate is:

[0018] Where J is the radon exhalation rate of the surface of the gas collecting hood.

[0019] Preferably, in step S2, 30min≤T1≤3h.

[0020] Preferably, the air pump working time in step S3 is 1-2 minutes.

[0021] Preferably, the volume of the gas collecting hood is V1, the volume of the exhaust component is V2, and the volume of the radon measuring chamber is V3, and the relationship among the three is V1>V2>V3.

[0022] The present invention discloses an off-site measuring device and method for radon exhalation rate on the surface of a uranium mine, comprising a gas collecting hood and an exhaust member, wherein a closed gas collecting channel is provided above the gas collecting hood, and two symmetrically arranged connecting pipes are provided on the surface of the gas collecting channel, and a socket corresponding to the connecting pipe is provided at the bottom of the exhaust member, and the exhaust member is connected to the gas collecting channel at the socket through the connecting pipe, and an air pump is provided at the end of one of the connecting pipes, and an output pipe extending outward is provided on the surface of the exhaust member, and an annular clip is provided inside the gas collecting channel, and a wire cage is supported above the annular clip, and a desiccant is provided in the wire cage; compared with the prior art, the off-site measuring device for radon exhalation rate on the surface of a uranium mine has the technical effect of being able to effectively collect and transfer precipitated radon gas, not being restricted by the gas collecting position and environment during measurement, and avoiding radiation hazards, and the measurement method can measure efficiently and accurately, providing technical support for restoring the ecology of uranium mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of the ex situ measurement device for radon exhalation rate on the surface of a uranium mine in the present invention.

[0024] Figure 2 This is a schematic diagram of the internal structure of the ex situ measurement device for radon exhalation rate on the surface of a uranium mine in the present invention.

[0025] Figure 3 For the present invention Figure 2 Schematic diagram of the enlarged structure at point A in the middle.

[0026] Figure 4 For the present invention Figure 2 Schematic diagram of the enlarged structure at point B in the middle.

[0027] Figure 5 This is a schematic diagram of the connection between the air extraction component and the radon detector in the present invention.

[0028] In the figure: 1. Gas collecting hood; 2. Sealing ring; 3. Gas collecting channel; 31. Ring bracket; 32. Wire cage; 33. Desiccant; 4. Thermohygrometer; 5. Connecting pipe; 51. Closure; 52. Air pump; 6. Vacuum element; 61. Flexible silicone layer; 7. Output pipe; 71. Valve; 8. Radon detector. DETAILED DESCRIPTION

[0029] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner, and thus only show components related to the present invention.

[0030] Please refer to Figure 1-5A device for measuring the radon exhalation rate on the surface of a uranium mine in situ comprises a gas collecting hood 1 and a gas extraction member 6. A closed gas collecting channel 3 is provided above the gas collecting hood 1. Two symmetrically arranged connecting pipes 5 are provided on the surface of the gas collecting channel 3. A socket corresponding to the connecting pipe 5 is provided at the bottom of the gas extraction member 6. The gas extraction member 6 is connected to the gas collecting channel 3 at the socket through the connecting pipe 5. An air pump 52 is provided at the end of one of the connecting pipes 5. An output pipe 7 extending outward is provided on the surface of the gas extraction member 6.

[0031] Among them, an annular holder 31 is provided inside the gas collecting channel 3, and a wire cage 32 is supported above the annular holder 31. A desiccant 33 is provided inside the wire cage 32. In this embodiment, the desiccant 33 can be a silica gel desiccant, anhydrous calcium sulfate desiccant, anhydrous calcium chloride desiccant, Nafion tube, etc.; so that the precipitated radon gas is dried and mixed.

[0032] Of course, in order to replace the desiccant 33, the annular tray 31 can be interference fit with the gas collecting channel 3, that is, the annular tray 31 is stuck on the inner wall of the gas collecting channel 3. When the desiccant needs to be replaced, the annular tray 31 can be directly removed.

[0033] In order to prevent a large amount of radon gas from dispersing inside the gas collecting hood during gas collection, a sealing ring 2 is provided on the circumference of the bottom end thereof.

[0034] When in use, first buckle the gas collecting hood 1 on the smooth surface area of ​​uranium ore so that the sealing ring 2 contacts the ground. If a large amount of radon gas is dispersed, it can also be buried through the soil; after the gas collecting hood 1 is placed, the radon gas precipitated from the ground gradually enters the gas collecting hood 1, and the precipitation time is about one hour (preferably 40-80 minutes); then install the exhaust component 6 on the gas collecting channel 3 to connect the gas collecting hood 1 with the exhaust component 6.

[0035] Since an air pump is provided at the bottom end of one of the connecting pipes 5, when the air pump 52 is running, the radon gas precipitated (inside the gas collecting hood 1) will pass through the desiccant and eventually enter the exhaust component 6; after entering, the gas in the exhaust component 6 will enter the gas collecting hood 1 from the other connecting pipe; the two connecting pipes 5 are one in and one out, so that the gases in the gas collecting hood 1 and the exhaust component 6 are evenly mixed; after mixing, the exhaust component 6 is removed; and it is taken to a safe area to measure the radon gas concentration.

[0036] In this embodiment, one end of the output tube 7 is connected to the exhaust member 6, and the other end is connected to the radon detector 8. A valve 71 is also provided on the output tube 7; the valve 71 is always in a closed state before measuring the radon concentration.

[0037] In order to achieve quick disassembly and assembly of the gas collecting hood 1 and the exhaust component 6, the connecting tube 5 is fixed on the surface of the gas collecting channel 3 and has a conical closing end 51 at the upper end. The inner wall of the socket on the bottom surface of the exhaust component 6 is provided with a flexible silicone layer 61. Under normal circumstances, the socket is self-sealed by the flexible silicone layer 61. After the connecting tube 5 is inserted into the flexible silicone layer 61 through the closing end 51, the gas collecting hood 1 is connected to the exhaust component 5. Similarly, when the internal gas is mixed and needs to be separated from the measurement, it is only necessary to pull out the gas collecting hood 6 as a whole. After pulling it out, the flexible silicone layer 61 is self-sealed again through elastic deformation.

[0038] It is understandable that in order to achieve communication between the gas collecting hood 1 and the exhaust component 6, the connecting pipe 5 is made of hard material, which can be an aluminum alloy tube, a copper tube or a hard plastic tube, as long as it can be inserted into the flexible silicone layer 61 to cause it to deform.

[0039] As a preferred solution, in order to detect the temperature and humidity of the radon evolution environment, a thermometer and humidity meter 4 may be provided on the outer wall of the gas collecting channel 3 .

[0040] Based on the above embodiment, the air pump 52 is a battery air pump, and the radon detector is a RAD7 radon detector, an FD216 radon detector or others.

[0041] The gas collecting hood and the exhaust part can be used in multiple sets to collect gas at multiple sampling points and realize multi-point simultaneous measurement.

[0042] The present invention provides a method for measuring radon exhalation rate on the surface of a uranium mine using an ex situ measuring device, comprising the following steps: S1: after the surface area of ​​the uranium mine to be measured is smoothed, gas collecting hoods are distributed at multiple points and fastened to the surface, so that the sealing ring at the bottom of the gas collecting hood is in contact with the surface of the medium; and the volume inside the gas collecting hood is V1, and the bottom area of ​​the gas collecting hood is S;

[0043] S2: After T1 time, radon gas overflows, and the radon gas concentration inside the gas collection hood is C1; then the gas extraction component is connected to the gas collection hood, where 30min≤T1≤3h;

[0044] S3: Start the air pump at the bottom of the connecting pipe in the gas collection channel for 1-2 minutes to evenly mix the radon gas inside the gas collection cover with the gas inside the exhaust component. After even mixing, separate the exhaust component. At this time, the exhaust component forms a closed space with a volume of V2, and the radon gas concentration inside the exhaust component is C2.

[0045] S4: Connect the output tube on the surface of the exhaust component to the air inlet and return port of the radon detector and then turn on the radon detector. The measuring time is T2, the measured radon concentration is C3, and the volume of the radon detection chamber inside the radon detector is V3;

[0046] The formula for calculating radon exhalation rate is:

[0047] Where J is the radon exhalation rate of the surface of the gas collecting hood.

[0048] That is: J is the radon exhalation rate on the surface of the medium where the gas collector is buckled, Bq / (m 2 s);

[0049] S is the surface area of ​​the medium on which the gas collecting piece is buckled, m 2 ;

[0050] T1 is the time interval between two samplings, i.e., gas collection time, s;

[0051] C3 is the radon concentration measured by the measuring instrument in Bq / m 3 ;

[0052] V1 is the volume between the gas collecting part and the surface of the buckled medium, m 3 ;

[0053] V2 is the internal volume of the exhaust part, m 3 ;

[0054] V3 is the volume of the measuring chamber in the measuring instrument, m 3

[0055] The volume of the gas collecting hood is V1, the volume of the exhaust component is V2, and the volume of the radon measuring chamber is V3. The relationship among the three is V1>V2>V3.

[0056] Formula derivation instructions:

[0057] Ignoring factors such as leakage and back diffusion of radon concentration in the gas collecting unit during the gas collection process, the radon concentration in the gas collecting unit increases linearly with the accumulation time. The accumulation method calculation formula used in the present invention can be simplified to the calculation formula given in EJ / T979-95 "Accumulation Method for Determination of Surface Radon Exhalation Rate":

[0058]

[0059] Where: J is the radon exhalation rate of the medium surface on which the gas collecting piece is buckled, Bq / (m 2 ·s); S is the surface area of ​​the medium on which the gas collecting piece is buckled, m 2 ; C is the radon concentration in the gas collecting part Bq / m 3 ; C0 is the initial radon concentration on the surface of the medium to be measured, which can generally be ignored; V is the volume between the gas collecting part and the surface of the medium to be measured, m 3 ; △T is the time interval between two samplings, that is, the gas collection time, s.

[0060] After the gas is mixed between the exhaust element and the gas collecting hood in step S3:

[0061] C2×(V1+V2)=C1×V1 (2)

[0062] but

[0063] When the radon detector measures the radon concentration C3 in step S4:

[0064] C3×(V3+V2)=C2×V2 (4)

[0065] Substituting (3) into (4), we get:

[0066]

[0067] Substituting (5) into (1), the radon exhalation rate is:

[0068]

[0069] The derivation principle of the shape change of the gas hood structure:

[0070] When measuring the surface radon exhalation rate, if it is necessary to shorten the accumulation time T under the premise of a certain exhalation rate J, it is necessary to reasonably design the ratio of the volume V of the accumulation container and the measured surface area S, and ensure that the radon concentration change ΔC can be detected by the instrument, that is, reach the lower limit of the instrument's measurement.

[0071] Formula (1) ignores the initial radon concentration C0 on the surface of the medium to be measured, that is, C0 = 0. Then formula (1) is simplified to:

[0072]

[0073] When the shape and size of the gas collector are determined, V and S are fixed values. Under the same medium for a short time, the radon exhalation rate J can be considered unchanged. At this time, formula (1-1) can be transformed into:

[0074]

[0075] In (1-2), J is the radon exhalation rate of the medium, which can be considered as a fixed value; T is the gas collection time, and C is the radon concentration in the gas collection device; within a certain period of time, J and C are in a certain proportional relationship.

[0076] If the gas collection time T needs to be shortened, V can be reduced or S can be increased. This means the V / S ratio is reduced. Within the permitted range of the radon exhalation rate measurement site and operation, S should be increased as much as possible, while V should be appropriately increased. In this embodiment, the base area S of the gas collection hood is increased, and the volume V is also appropriately increased, but V / S is moderately reduced compared to the original gas collection hood.

[0077] Through the above measurement method, the radon gas precipitation rate (concentration) on the surface of the medium in the uranium mine decommissioning and treatment area can be effectively measured. The measurement efficiency is high and the data is accurate, providing technical support for the ecological restoration of uranium mine decommissioning and treatment.

[0078] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A device for measuring the ex-situ radon exhalation rate on the surface of a uranium mine, characterized in that: It includes an air collecting hood and an air extraction component. A closed air collecting channel is provided above the air collecting hood. Two symmetrically arranged connecting pipes are provided on the surface of the air collecting channel. A socket corresponding to the connecting pipe is provided at the bottom of the air extraction component. The air extraction component is connected to the air collecting channel at the socket through the connecting pipe. An air pump is provided at the end of one of the connecting pipes, and an output pipe extending outward is provided on the surface of the air extraction component.

2. The device for measuring radon exhalation rate on the surface of a uranium mine according to claim 1, characterized in that: An annular card holder is provided inside the gas collecting channel, a wire cage is supported above the annular card holder, and a desiccant is provided inside the wire cage.

3. The device for measuring the radon exhalation rate on the surface of a uranium mine according to claim 1 or 2, characterized in that: One end of the output pipe is connected to the air extraction component, and the other end is connected to the radon detector. A valve is also provided on the output pipe.

4. The device for measuring the ex situ radon exhalation rate on the surface of a uranium mine according to claim 1 or 2, characterized in that: The connecting tube is fixed on the surface of the gas collecting channel and closed at the upper end. The inner wall of the socket on the bottom surface of the exhaust component is provided with a flexible silicone layer. Under normal circumstances, the socket is self-sealed by the flexible silicone layer. After the connecting tube is inserted into the flexible silicone layer, the gas collecting hood is connected to the exhaust component.

5. The device for measuring radon exhalation rate on the surface of a uranium mine according to claim 1, characterized in that: A sealing ring is provided on the circumference of the bottom end of the gas collecting hood.

6. The device for measuring radon exhalation rate on the surface of a uranium mine according to claim 1, characterized in that: A thermometer and hygrometer is provided on the outer wall of the gas collecting channel.

7. A method for measuring radon exhalation rate on the surface of a uranium mine using an ex situ measuring device, characterized in that: The steps include: S1: After the surface area of ​​the uranium ore to be tested is smoothed, the gas collecting hoods are distributed at multiple points and buckled on the surface so that the sealing ring at the bottom of the gas collecting hood fits the surface of the medium. The volume inside the gas collecting hood is V1, and the bottom area of ​​the gas collecting hood is S. S2: After T1 time, radon gas overflows, and the radon gas concentration inside the gas collection hood is C1. Then the gas extraction component is connected to the gas collection hood; S3: Start the air pump at the bottom of the connecting pipe in the gas collection channel to mix the radon gas inside the gas collection cover with the gas inside the exhaust component. After the mixture is evenly mixed, the exhaust component is separated. At this time, the exhaust component forms a closed space with a volume of V2, and the radon gas concentration inside the exhaust component is C2. S4: Connect the output tube on the surface of the exhaust component to the air inlet and return port of the radon detector and then turn on the radon detector. The measuring time is T2, the measured radon concentration is C3, and the volume of the radon detection chamber inside the radon detector is V3; The formula for calculating radon exhalation rate is: Where J is the radon exhalation rate of the surface of the gas collecting hood.

8. The measuring method of the uranium mine surface radon exhalation rate ex situ measuring device according to claim 7, characterized in that: In the step S2, 30 min ≤ T1 ≤ 3 h.

9. The measuring method of the ex situ measuring device for measuring radon exhalation rate on the surface of a uranium mine according to claim 7, characterized in that: The air pump working time in step S3 is 1-2 minutes.

10. The measuring method of the ex situ measuring device for uranium mine surface radon exhalation rate according to claim 7, characterized in that: The volume of the gas collecting hood is V1, the volume of the exhaust component is V2, and the volume of the radon measuring chamber is V3. The relationship between the three is V1>V2>V3.

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