A method of simulating radioactive nuclides using rhenium 90 Sr- 90 Y. Methods for studying the efficiency of surface contamination wiping

Abstract

The present application belongs to the field of radiation environment measurement, and particularly relates to a method for simulating radionuclide surface contamination wiping efficiency by using rhenium element 90 Sr- 90 Y research surface contamination wiping efficiency method. Through the radioactive characteristics of rhenium element, combined with radiation counting device for quantitative analysis, the present application can accurately evaluate the removal effect of radioactive contamination on different surface materials, and the present application provides a method for simulating and researching radionuclide surface contamination wiping efficiency by using non-radioactive element rhenium element 90 Sr- 90 Y surface contamination wiping efficiency method, reduces the use of radionuclide, is simple and easy to operate, is friendly and safe to personnel and environment, reduces research cost, has various material applicability and operability; the present application can accurately evaluate the removal effect of radioactive contamination on different sample materials, has wide applicability, and can provide technical support for actual scientific decontamination and cleaning work.

Description

Technical Field

[0001] This invention belongs to the field of radiation environment measurement, and specifically relates to a method for simulating radioactive nuclides using rhenium. 90 Sr- 90 Y is a method for studying the efficiency of wiping surface contaminants. Background Technology

[0002] Strontium (Sr) and yttrium (Y) are common radioactive nuclides with long half-lives and strong radioactivity, posing a significant threat to the environment and human health. After radiation contamination occurs, these radioactive nuclides, such as... 90 Sr- 90 Y and other radioactive contaminants often adhere to the surfaces of objects made of various materials such as metal, plastic, glass, concrete, and ceramics. In order to control the transfer of these radioactive contaminants and assess whether the radioactivity per unit area exceeds the surface contamination control level, it is necessary to measure the surface contamination of the contaminated surface.

[0003] Direct measurement involves using surface contamination measuring instruments or monitoring instruments to determine the sum of contamination. However, when there are interfering radiation factors such as non-radioactive liquids or precipitates, or when there are spatial limitations, direct measurement may be particularly difficult or even impossible to implement.

[0004] Based on the aforementioned existing technologies, the applicant has conducted persistent and beneficial explorations and repeated experiments, found a solution to the aforementioned technical problems, and formed the technical solution to be introduced. Summary of the Invention

[0005] To address the problems of existing technologies, this invention proposes a method for simulating radioactive nuclides using the non-radioactive element rhenium. 90 Sr- 90 Y is a method for studying the wiping efficiency of surface contamination, which can achieve the goal of safely, environmentally friendly and low-cost research on the wiping efficiency F of contamination on the surfaces of different objects;

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method of simulating radioactive nuclides using rhenium 90 Sr- 90 Y studies the method for wiping surface contaminants, which includes the following steps:

[0008] 1) The experiment used multiple experimental material bodies with different materials and surface smoothness. The experimental material bodies were either flat or irregularly shaped.

[0009] The experimental materials include, but are not limited to, frosted PP boards, acrylic boards, silicone boards, stainless steel boards, aluminum boards, frosted aluminum boards, rubber flooring, floor tiles, wall tiles, wooden floors, beakers, Erlenmeyer flasks, and other materials with flat or irregular surfaces.

[0010] 2) Apply a certain amount of rhenium standard solution to the surface of the selected experimental material, let it stand and dry, and then wipe the contaminated parts of the experimental material surface with various wiping methods, both with and without clamps, using dry and uniformly wetted wiping materials.

[0011] In step 2), the specified amount of rhenium standard solution is selected from ammonium perrhenate standard solution with a concentration of 100–500 μg / mL, preferably 200 μg / mL. When using, take 0.1–1.0 mL of the solution, preferably 0.4 mL, and evenly coat it onto the selected experimental material surface, allowing it to stand and air dry. The coating involves using a dispensing gun or a graduated tube to draw up the solution and then evenly applying it to the object. The air-drying process involves placing the sample in a fume hood or a well-ventilated, clean place for 1–3 days to allow it to air dry naturally, resulting in the desired contaminated sample. The various wiping materials include dry filter paper, dry cotton cloth, and wet filter paper, wet cotton cloth, etc., cut to dimensions approximately similar to the size of the fixture or experimental material. The moisture content of the evenly wetted wiping material is 0.008 g / cm³. 2 —0.020g / cm 2 The preferred value is 0.012 g / cm³. 2 .

[0012] 3) Cut off the area where the bottom of the wiping material contacts the contaminated part of the experimental material, place it in a container, and extract rhenium by soaking it in nitric acid of a certain concentration and volume. In step 3), dilute nitric acid with a concentration of 3%–10% is used, preferably 5% concentration, and the soaking time is at least 2 hours. Further, the concentration range is 4.5%–5.5%, and the volume range is 20 ml–60 ml. Specifically, when using a clamp to hold the wiping material, use 20 mL of 5% nitric acid for soaking; when directly pressing the wiping material by hand, use 60 mL of 5% nitric acid for soaking. During the soaking process, shake the solution several times to ensure that the rhenium on the wiping material is completely dissolved in the solution.

[0013] 4) After leaching, the rhenium content in the leaching solution is determined using inductively coupled plasma atomic emission spectrometry (ICP-AES), and the rhenium wiping efficiency F of the wiping material is calculated. Re Step 4) Rhenium wiping efficiency F Re The calculation formula is: Rhenium wiping efficiency F Re =Measured rhenium content / Coated rhenium content × 100%.

[0014] 5) Verify the obtained rhenium wiping efficiency F Re The degree of simulation, verification method: a certain amount 90 Sr- 90A standard solution (Y) was applied to the surface of the selected experimental material. After drying, the total β count rate (n1) on the surface of the experimental material before wiping was measured using a surface contamination meter. The material was then wiped using various methods, both with and without clamps, with a fixed wiping technique, on the contaminated areas of the experimental material surface. The total β count rate (n2) on the wiped material was measured using a surface contamination meter. The value of the experimental material at the time of measurement by the surface contamination meter was calculated. 90 Sr- 90 Y wiping efficiency F Sr-Y The wiping efficiency F calculated using the non-radioactive element rhenium was compared with that of the experimental material. Re and the use of radioactive elements 90 Sr- 90 The wiping efficiency F is calculated by Y measurement. Sr-Y Verification using rhenium to simulate radioactive nuclei 90 Sr- 90 Y studies the feasibility and accuracy of methods for improving the efficiency of surface contamination wiping. Step 5) involves taking 0.1–1.0 mL of... 90 Sr- 90 Y standard solution (solution system: 0.1 mol / L HCl, 30 μg / g Sr + 30 μg / g Y carrier solution, 90 Sr- 90 A specific activity of γ (10⁷ Bq / g) was uniformly coated onto the experimental material. The material was then placed in a fume hood or a clean, well-ventilated area for 1-3 days to air dry. The radionuclide content of the object was then determined using a surface contamination analyzer. 90 Sr- 90 The total β count rate n1 of Y, and the radionuclides on the wiping material. 90 Sr- 90 The total count rate n2 of Y on β, 90 Sr- 90 Y wiping efficiency F Sr-Y The calculation formula is: F Sr-Y = n2 / n1 × 100%. The CoMo 170 portable surface contamination monitor was selected for surface contamination measurement. This method uses the CoMo 170 portable surface contamination monitor to measure β rays, representing the instrument's response count of β rays under these conditions.

[0015] The clamped wiping method further describes using clamps to hold the wiping material, maintaining constant pressure and wiping the surface of the experimental material slowly and uniformly; the clampless wiping method describes directly pressing the wiping material with your hand, maintaining constant pressure and wiping the surface of the experimental material slowly and uniformly. For irregularly shaped experimental materials, the clampless wiping method is preferred; the constant pressure is selected from 1 to 20 N, preferably 4 N; the uniform speed is selected from 0.4 to 1.5 cm / s, preferably 0.8 cm / s.

[0016] Furthermore, the main body of the clamp is a detachable river dam-shaped structure.

[0017] Compared with existing technologies, the beneficial effects of this invention are: This invention provides a method for simulating the study of radioactive nuclides using the non-radioactive element rhenium. 90 Sr- 90 This invention provides a method for improving the efficiency of surface contamination wiping, reducing the use of radioactive nuclides, and is simple and easy to operate. It is friendly and safe for personnel and the environment, reduces research costs, and is applicable to a variety of materials. This invention can accurately evaluate the removal effect of radioactive contamination on different sample materials, has wide applicability, and can provide technical support for practical scientific decontamination and cleaning work. Attached Figure Description

[0018] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0019] Figure 1 This is the standard curve diagram of rhenium in this invention;

[0020] Figure 2 This is a bar chart showing the wiping efficiency of different experimental materials in this invention;

[0021] Figure 3 This is a curve showing the effect of wiping humidity in this invention;

[0022] Figure 4 This is an experimental curve of wiping speed in this invention;

[0023] Figure 5 This is an experimental curve showing the selection of wiping stability time in this invention;

[0024] Figure 6 This is the rhodium background interference image in this invention.

[0025] Figure 7 This is the rhenium background interference diagram in this invention.

[0026] Figure 8 This is the indium background interference diagram in this invention.

[0027] Figure 9 This is a schematic diagram of the main structure of the clamp in this invention. Figure 1 ;

[0028] Figure 10 This is a schematic diagram of the main structure of the clamp in this invention. Figure 2 ;

[0029] Figure 11 This is a schematic diagram of the main structure of the clamp in this invention. Figure 3 .

[0030] Among them: 100, base; 200, trapezoidal groove; 300, pressure plate; 310, screw; 320, wing nut; 400, wiping material body; 210, bolt hole one; 311, bolt hole two. Detailed Implementation

[0031] The present invention will be further described in detail below through embodiments. These embodiments are only used to illustrate the present invention and do not limit the scope of the present invention.

[0032] Indirect wiping measurement is often used to measure removable contaminants. However, due to the different material characteristics and surface roughness of the contaminants, the degree and distribution of radioactive nuclide contaminants adsorbed on the object surface vary greatly. This results in a great deal of uncertainty in the wiping efficiency during wiping measurement, making it difficult to assess the degree of surface contamination and the decontamination effect effectively, and hindering the rapid provision of technical support for subsequent work decisions.

[0033] The indirect wiping measurement method largely depends on the wiping efficiency F of different object surfaces. Theoretically, this wiping efficiency can be experimentally determined by the method of "repeated wiping," that is, calculating the total wiping radioactivity A after multiple wipings. T Radioactivity A removed by wiping P With A T The method for calculating wiping efficiency F involves using a "repeated wiping" experiment to directly wipe a radioactively contaminated sample with a wiping material, and then measuring the radioactivity A on the wiping material using a handheld surface contamination measuring instrument or monitor. P This method of determining and calculating the wiping efficiency F using the "repeated wiping" experiment has some difficulties and shortcomings in practical work. For example, the experiment uses radioactive nuclides such as... 90 Sr- 90 Y, etc., easily cause environmental pollution and pose a certain radiation hazard to the human body during experiments, requiring radiation protection for experimental personnel; radioactive nuclides are strictly controlled, difficult to purchase, and expensive, and their waste disposal is also difficult and costly; these shortcomings greatly hinder the use of the wiping method to study the wiping efficiency F of surface contamination on different objects; therefore, if a method that can replace... 90 Sr- 90 Using radionuclides such as Y to study the wiping efficiency F of contamination on different object surfaces can provide a safe, environmentally friendly, low-cost method that can quickly assess the degree of radioactive surface contamination and the effectiveness of decontamination, which is beneficial to improving the quality of work on measuring radiation surface contamination.

[0034] Example 1: As Figure 1-6 The image shows a method of simulating radioactive nuclides using rhenium. 90 Sr- 90Y studies the method for wiping surface contaminants, which includes the following steps:

[0035] 1) Take 0.4 mL of ammonium perperureate solution (concentration of 200 μg / mL) and spread it evenly on the above sample material. Place it in a fume hood for 1-2 days to allow it to air dry naturally.

[0036] 2) Use scissors to cut the filter paper or cotton cloth into shapes suitable for wiping and sampling (matching the size of the clamp or the area to be wiped). Evenly wet the filter paper or cotton cloth with purified water until no water seeps out; the moisture content should be approximately 0.012 g / cm³. 2 .

[0037] 3) After standing for 2 minutes, press the wiping material firmly against the base 100 of the clamp, turning over any excess material into the trapezoidal groove 200. Press the wiping material firmly with the pressure plate 300, and tighten the base 100 and pressure plate 300 with screws 310 to secure the wiping material. Press the clamp body holding the wiping material onto the surface to be tested and wipe slowly and evenly, avoiding repeated wiping of the same position. The wiping area should be ≥100cm². 2 The wiping speed is 0.8 cm / s, the wiping pressure is 4 N, and the wiping frequency is 1.

[0038] 4) Remove the filter paper or cotton cloth and place it in a 100 ml plastic bottle. Use 5% nitric acid solution to make up to 20.00 ml and soak for 2 hours. Shake the extract several times during the soaking process.

[0039] 5) Power on the inductively coupled plasma atomic emission spectrometer according to the instruction manual, set the instrument operating conditions, and ignite the torch. The instrument operating conditions are as follows: rhenium measurement wavelength is 221.4 nm, power is 1150 W, peristaltic pump speed is 50 r / min, auxiliary gas flow rate is 1.0 L / min, nebulizing gas flow rate is 0.5 L / min (measured by a rotor flowmeter), rinsing time is 30 s, integration time is 30 s, and the measurement is performed using a horizontal observation method. The preparation of the rhenium standard curve includes the following steps: Transfer 5.0 mL of rhenium standard stock solution (1000 μg / mL) to a 100 mL volumetric flask, add 5.0 mL of hydrochloric acid, dilute with water to the mark, and mix. The mass concentration of this solution is 50 μg / mL. Then, take 0, 0.40, 1.00, 2.00, 4.00, and 5.00 mL of rhenium standard working solution (50 μg / mL) respectively, place them in a 100 mL volumetric flask, add 1.0 mL of hydrochloric acid, dilute with water to the mark, and mix. The prepared rhenium standard working solutions had mass concentrations of 0, 0.20, 0.50, 1.00, 2.00, and 2.50 μg / mL. Plotting the mass concentration ρ (μg / mL) of the rhenium standard solutions on the x-axis and the signal intensity I on the y-axis, the linear equation for the rhenium standard series was obtained as y = 9964.3x + 15.968, with a linear correlation coefficient of 0.9999. The rhenium content was determined, and the amount of ammonium perrhenate was calculated. The ratio of the measured ammonium perrhenate content in the solution to the ammonium perrhenate content sprayed on the experimental material was used to calculate the wiping efficiency F. Re Rhenium wiping efficiency F Re The calculation formula is: Rhenium wiping efficiency F Re =Measured rhenium content / Coated rhenium content × 100%.

[0040] 6) Take 0.4 ml 90 Sr- 90 Y standard solution (solution system: 0.1 mol / L HCl, 30 μg / g Sr + 30 μg / g Y carrier solution, 90 Sr- 90 A uniform coating of a radionuclide with a specific activity of 10⁷ Bq / g was applied to the same experimental material and placed in a fume hood for 1-2 days to allow it to air dry naturally. The radionuclide was then measured using a surface contamination analyzer. 90 Sr- 90 The total β count rate of Y, n1; Using scissors, cut the filter paper or cotton cloth into shapes suitable for wiping and sampling (matching the size of the clamp or the area to be wiped). Evenly wet the filter paper or cotton cloth with pure water until no water seeps out; the moisture content is approximately 0.012 g / cm³. 2 After letting it stand for 2 minutes, use a clamp to hold the wiping material and press it onto the surface to be tested. Wipe slowly and evenly, avoiding repeatedly wiping the same area. The wiping area should be ≥100cm².2 The wiping speed was 0.8 cm / s, the wiping pressure was 4 N, and the wiping was performed once. Radionuclides were measured using a surface contamination measuring instrument. 90 Sr- 90 β total count rate n2 of Y; calculate 90 Sr- 90 Y wiping efficiency F Sr-Y The calculation formula is: F Sr-Y = n2 / n1 × 100%. Evaluation F Re With F Sr-Y Verification using rhenium to simulate radioactive nuclides 90 Sr- 90 Y studies the feasibility and accuracy of methods for improving the efficiency of surface contamination wiping.

[0041] Example 2: Figure 1-6 The image shows a method of simulating radioactive nuclides using rhenium. 90 Sr- 90 Y studies the method for wiping surface contaminants, which includes the following steps:

[0042] 1) Take 0.4 ml of ammonium perperureate solution (concentration of 200 μg / ml) and spread it evenly on the above sample material. Place it in a fume hood for 1-2 days to allow it to air dry naturally.

[0043] 2) Use scissors to cut the filter paper or cotton cloth into shapes suitable for wiping and sampling (matching the size of the clamp or the area to be wiped). Evenly wet the filter paper or cotton cloth with purified water until no water seeps out; the moisture content should be approximately 0.012 g / cm³. 2 .

[0044] 3) After letting it stand for 2 minutes, hold the wiping material directly in your hand and press it onto the surface to be tested. Wipe slowly and evenly, avoiding repeatedly wiping the same area. The wiping area should be ≥100cm². 2 The wiping speed is 0.8 cm / s, the wiping pressure is 4 N, and the wiping frequency is 1.

[0045] 4) Remove the filter paper or cotton cloth and place it in a 100 ml plastic bottle. Use 5% nitric acid solution to make up to 60.00 ml and soak for 3 hours. Shake the extract several times during the soaking process.

[0046] 5) Power on the inductively coupled plasma atomic emission spectrometer according to the instruction manual, set the instrument operating conditions, and ignite the torch. The instrument operating conditions are as follows: rhenium measurement wavelength is 221.4 nm, power is 1150 W, peristaltic pump speed is 50 r / min, auxiliary gas flow rate is 1.0 L / min, nebulizing gas flow rate is 0.5 L / min (measured by a rotor flowmeter), rinsing time is 30 s, integration time is 30 s, and the measurement is performed using a horizontal observation method. The preparation of the rhenium standard curve includes the following steps: Transfer 5.0 mL of rhenium standard stock solution (1000 μg / mL) to a 100 mL volumetric flask, add 5.0 mL of hydrochloric acid, dilute with water to the mark, and mix. The mass concentration of this solution is 50 μg / mL. Then, take 0, 0.40, 1.00, 2.00, 4.00, and 5.00 mL of rhenium standard working solution (50 μg / mL) respectively, place them in a 100 mL volumetric flask, add 1.0 mL of hydrochloric acid, dilute with water to the mark, and mix. The prepared rhenium standard working solutions had mass concentrations of 0, 0.20, 0.50, 1.00, 2.00, and 2.50 μg / mL. Plotting the mass concentration ρ (μg / mL) of the rhenium standard solutions on the x-axis and the signal intensity I on the y-axis, the linear equation for the rhenium standard series was obtained as y = 9964.3x + 15.968, with a linear correlation coefficient of 0.9999. The rhenium content was determined, and the amount of ammonium perrhenate was calculated.

[0047] The wiping efficiency F was calculated by comparing the measured ammonium perrhenate content in the solution with the ammonium perrhenate content sprayed on the experimental material. Re Rhenium wiping efficiency F Re The calculation formula is: Rhenium wiping efficiency F Re =Measured rhenium content / Coated rhenium content × 100%.

[0048] 6) Take 0.4 ml 90 Sr- 90 Y standard solution (solution system: 0.1 mol / L HCl, 30 μg / g Sr + 30 μg / g Y carrier solution, 90 Sr- 90 A uniform coating of a radionuclide with a specific activity of 10⁷ Bq / g was applied to the same experimental material and placed in a fume hood for 1-2 days to allow it to air dry naturally. The radionuclide was then measured using a surface contamination analyzer. 90 Sr- 90 The total β count rate of Y, n1; Using scissors, cut the filter paper or cotton cloth into shapes suitable for wiping and sampling (matching the size of the clamp or the area to be wiped). Evenly wet the filter paper or cotton cloth with pure water until no water seeps out; the moisture content is approximately 0.012 g / cm³. 2After letting it stand for 2 minutes, use a clamp to hold the wiping material and press it onto the surface to be tested. Wipe slowly and evenly, avoiding repeatedly wiping the same area. The wiping area should be ≥100cm². 2 The wiping speed was 0.8 cm / s, the wiping pressure was 4 N, and the wiping was performed once. Radionuclides were measured using a surface contamination measuring instrument. 90 Sr- 90 β total count rate n2 of Y; calculate 90 Sr- 90 Y wiping efficiency F Sr-Y The calculation formula is: F Sr-Y = n2 / n1 × 100%. Evaluation F Re With F Sr-Y Verification using rhenium to simulate radioactive nuclides 90 Sr- 90 Y studies the feasibility and accuracy of methods for improving the efficiency of surface contamination wiping.

[0049] The main body of the clamp is a detachable river dam-shaped structure.

[0050] The main body of the clamp includes a base 100, which is a rectangular plate structure; the bottom surface of the base 100 is a flat surface.

[0051] The trapezoidal groove 200 has a cross-section in the shape of "︺" and is located in the middle of the upper part of the base 100. The trapezoidal groove 200 extends from one end of the base 100 to the other end.

[0052] The pressure plate 300 has a cross-section shaped like a "︺", which is matched and correspondingly set with the trapezoidal groove 200.

[0053] The wiping material body 400 is a sheet structure that wraps around the base 100. Both ends of the wiping material body 400 are located in the trapezoidal groove 200. The pressure plate 300 is fixed in the trapezoidal groove 200, and the bottom of the pressure plate 300 presses and fixes the wiping material body 400.

[0054] The specific pressure plate 300 is fixedly connected to the base 100 by screws 310 and wing nuts 320;

[0055] A bolt hole 210 is made through the middle of the trapezoidal groove 200;

[0056] Bolt hole 311 is made through the middle position of pressure plate 300;

[0057] When the pressure plate 300 is installed in the trapezoidal groove 200, bolt hole 210 and bolt hole 311 are set accordingly.

[0058] Screw 310 passes through bolt hole 210 and bolt hole 311, and then the pressure plate 300 is fixed to the base 100 by wing nut 320. In use, the wiping material body 400 is tightly attached to the bottom surface of the base 100, and the excess parts at both ends of the wiping material body 400 are flipped into the trapezoidal groove 200. The pressure plate 300 is used to press and fix the two ends of the wiping material body 400 to prevent it from falling off during wiping.

[0059] The bottom of bolt hole 210 is tapered, and the bottom of screw 310 can be matched and inserted into bolt hole 210. At this time, the bottom surface of screw 310 is flush with the bottom surface of base 100.

[0060] The principle of rhenium experiment: In order to avoid interference from elements in the environment, the experimental elements should be low in abundance on Earth, have good salt stability, be easily soluble, non-toxic and harmless, safe and easy to operate. Rhenium, rhodium and indium meet the requirements.

[0061] In comparison, common salts of rhodium include rhodium chloride and rhodium nitrate. Rhodium chloride is hygroscopic and insoluble in water, acids, and aqua regia, but soluble in methanol and cyanide solutions. Rhodium nitrate is insoluble in water, highly toxic, flammable, and classified as a prohibited hazardous material. Common salts of indium include indium sulfate, which, while readily soluble in water, is moderately toxic. Common salts of rhenium include ammonium perrhenate, which has wide industrial applications, is stable at room temperature, and is readily soluble in hot water. For these reasons, ammonium perrhenate, a common salt of rhenium, was chosen for the simulation experiment. Regarding instrument testing: indium has a low signal value; rhodium has significant background interference; while rhenium has a high signal strength, high sensitivity, and no interference, meeting the selection criteria for tracer elements. Table 1 shows the signal intensities of 0.5 μg / mL standard solutions of indium, rhenium, and rhodium measured using inductively coupled plasma atomic emission spectrometry (ICP-AES), and the signal-to-background ratios were calculated for each.

[0062]

[0063] Table 1

[0064] at the same time Figure 6 , 7 8 represents the background interference images of rhodium (Rh), rhenium (Re), and indium (In), derived from... Figure 6 , Figure 7 , Figure 8 It can be seen that, Figure 6 Rhodium exhibits significant background interference, resulting in spectral interference. Figure 8 Indium has low background interference but low signal strength and low sensitivity. Figure 7 Rhenium has low background interference and high signal intensity, which means that the sensitivity of element determination is also high. Therefore, rhenium is the best experimental element.

[0065] Experimental verification of the wiping efficiency of rhenium and radioactive elements strontium-90 and yttrium-90:

[0066] To illustrate the use of non-radioactive elements to simulate radioactive nuclides 90 Sr- 90 To study the feasibility and accuracy of surface contamination wiping efficiency, a conventional method using radioactive elements strontium-90 and yttrium-90 was employed. This involved directly coating a certain amount of strontium-90 and yttrium-90 onto the experimental material and then using a CoMo 170 portable surface contamination monitor to determine the radionuclides on the material. 90 Sr- 90 The total β count rate n1 of Y, and the radionuclides on the wiping material. 90 Sr- 90 The total count rate n2 of Y on β, 90 Sr- 90 Y wiping efficiency F Sr-Y The calculation formula is: F Sr-Y = n2 / n1 × 100%. Table 2 shows the wiping efficiency of rhenium and... 90 Sr- 90 Y wiping efficiency F Sr-Y Comparison table.

[0067]

[0068] Table 2

[0069] Choosing the right wiping humidity:

[0070] The humidity of the wiping material is a crucial factor affecting the wiping efficiency of radioactive surfaces. When the humidity of the wiping material is low, its ability to adsorb radioactive contaminants may be limited. Dry wiping material does not make sufficient contact with the contaminated surface, making it difficult to effectively capture and adsorb contaminant particles, resulting in reduced wiping efficiency. This may leave some contaminants on the surface, unable to be completely removed. As the humidity of the wiping material increases, its moist surface adheres better to the contaminated surface, enhancing its affinity and adsorption of contaminants. The presence of water molecules helps dissolve and loosen some tightly adhered contaminants, thereby improving the wiping material's ability to capture contaminants and thus increasing wiping efficiency. Experiments were conducted on cotton cloth with moisture levels of 0, 1.0, 2.0, and 3.0. Figure 3 As shown, the results indicate that the wiping moisture content is stable between 2.0 and 3.0.

[0071] Selection of stabilization time:

[0072] The stabilization time refers to the time it takes for the moisture in the wetted cotton cloth to be evenly dispersed. Ensuring uniform humidity in the cloth is crucial, and choosing an appropriate stabilization time is essential. If the stabilization time is too short, the moisture in the cloth may not be evenly dispersed, leading to low wiping efficiency, incomplete contaminant collection, underestimation of contamination levels, and affecting detection accuracy. Conversely, if the stabilization time is too long, the moisture in the wiping material may evaporate, altering its adsorption properties; it may also increase operation time and cost, reducing detection efficiency. This experiment tested the humidity stabilization time of the cotton cloth at 0, 1.0, 2.0, 3.0, 4.0, and 5.0 min. Figure 5 As shown, from Figure 5 It can be seen that the humidity of the cotton fabric stabilizes in 2-3 minutes.

[0073] Selection of wiping speed:

[0074] In the wiping operation for detecting radioactive contamination, a fast wiping speed may not allow the wiping material sufficient time to fully contact and adsorb contaminants onto the contaminated surface, resulting in reduced wiping efficiency, ineffective removal of radioactive contaminants, and impacting the accuracy of test results. An excessively slow wiping speed may increase operation time and reduce work efficiency. Furthermore, prolonged slow wiping of the same area may alter the physical or chemical state of contaminants due to frictional heat, or even cause contaminant diffusion. This experiment tested four speeds: 0.4 cm / s, 0.6 cm / s, 0.8 cm / s, and 1.5 cm / s. The results are shown below. Figure 4 ,from Figure 4 It can be seen that the results of rapid wiping are unstable and the wiping efficiency is low. Therefore, the experiment selected a wiping speed of 0.8 cm / s.

[0075] Selection of wiping pressure and number of wipes:

[0076] Since both parameters affect wiping efficiency, experiments were conducted. With a fixed number of wipes (1), the optimal wiping pressure was varied between 1-5 N. The results showed that the wiping efficiency was most stable at 4 N, with the RSD (Responsible Displacement) of wiping efficiency less than 5% for various types of materials. With a fixed wiping pressure of 4 N, the number of wipes varied between 1-5. For most smooth and flat materials, after one wipe, the results of 2-5 wipes were essentially zero. However, for materials with corrugated surfaces, such as textured aluminum sheets, multiple wipes were required to meet the requirements.

[0077] Choosing a wiping method:

[0078] With fixed wiping pressure and humidity, the contaminated boards are wiped using both clamps and hands. In practice, we can choose the appropriate wiping method according to the shape of the material. For example, clamps are more efficient and effective for wiping flat materials, while hand wiping is more effective for irregularly shaped materials.

[0079] Leaching experiment:

[0080] In this method, the leaching experiment involves soaking filter paper or cotton cloth in a 5% nitric acid solution for at least 2 hours. The leaching solution is shaken multiple times during the leaching process to improve leaching efficiency. To determine the leaching efficiency, a rhenium standard solution is quantitatively coated onto the filter paper and cotton cloth. Coats are 0.1, 0.2, 0.3, and 0.4 mL of an 80.00 μg / mL rhenium solution, respectively. After stabilizing for 10 minutes, 20.00 mL of 5% nitric acid solution is applied for leaching. After the required leaching time is reached, the rhenium content is determined using inductively coupled plasma atomic emission spectrometry (ICP-AES). The leaching efficiency is calculated, and the results are shown in Table 3. Table 3 presents the experimental data for the leaching efficiency of 5% nitric acid. The data shows that the leaching efficiency for the four types of contaminants on the filter paper and cotton cloth ranges from 100.02% to 101.63%. This demonstrates that 5% nitric acid solution is effective in removing contaminants of different concentrations. This method uses 5% nitric acid solution for leaching.

[0081]

[0082] Table 3

[0083] Experiment on the selection of wiping materials:

[0084] Different wiping materials have a significant impact on wiping efficiency. Filter paper, due to its dense fiber structure, has a strong adsorption capacity for small particles, but may not be efficient enough when wiping larger areas. Cotton cloth has good water absorption and can effectively remove liquid contaminants, but its removal effect on some highly viscous contaminants is limited. Seven wiping experiments were conducted on four types of boards using filter paper and cotton cloth, and the results are shown in Table 4. Table 4 shows the wiping data for the four types of boards using filter paper and cotton cloth.

[0085]

[0086] Table 4

[0087] Table 4 shows that the average wiping efficiencies of the bean-patterned aluminum sheet using filter paper and cotton cloth were 15.60% and 31.89%, respectively, with RSDs of 11.77% and 3.39%. For the plastic sheet, the average wiping efficiencies were 35.09% and 51.75%, respectively, with RSDs of 17.77% and 1.98%. For the stainless steel sheet, the average wiping efficiencies were 70.82% and 81.49%, respectively, with RSDs of 7.47% and 3.24%. For the soft silicone sheet, the average wiping efficiencies were 92.94% and 94.07%, respectively, with RSDs of 3.10% and 1.06%. The wiping efficiency of cotton cloth was higher than that of filter paper for all four types of sheets, and the wiping efficiency remained stable. For the soft silicone sheet, the wiping efficiencies of filter paper and cotton cloth were similar and stable. In practical applications, if a high and stable wiping efficiency is desired, cotton cloth should be used for wiping rough and uneven surfaces, while filter paper or cotton cloth can be used for smooth and flat surfaces, with cotton cloth offering better wiping efficiency.

[0088] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship of the device or equipment during normal use, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention in this respect.

[0089] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for simulating radioactive nuclides using rhenium. 90 Sr- 90 Y is a method for studying the efficiency of surface contamination wiping, characterized by... Includes the following steps: 1) The experiment used multiple experimental material bodies with different materials and surface smoothness; the experimental material bodies were either flat or irregularly shaped. 2) Apply a certain amount of rhenium standard solution to the surface of the selected experimental material, let it stand and dry, and then wipe the material body with various methods. In both the case of having a clamp and without a clamp, use a dry wiping material body and a uniformly wetted wiping material body to wipe the contaminated parts of the experimental material body surface. 3) Cut off the area where the bottom of the wiping material contacts the contaminated part of the experimental material, put it in a container, and extract rhenium by soaking it in nitric acid of a certain concentration and volume. Use dilute nitric acid with a concentration of 3% to 10%. When using 5% nitric acid, the soaking time should be more than 2 hours. 4) After leaching, the rhenium content in the leaching solution is determined using inductively coupled plasma atomic emission spectrometry (ICP-AES), and the rhenium wiping efficiency of the wiping material is calculated. F Re Step 4) Rhenium wiping efficiency F Re The calculation formula is: rhenium wiping efficiency F Re =Measured rhenium content / Coated rhenium content × 100%; 5) Verify the obtained rhenium wiping efficiency F Re The degree of simulation, verification method: a certain amount 90 Sr- 90 The Y standard solution was coated onto the surface of the selected experimental material. After being allowed to dry, the total β count rate of the experimental material surface before wiping was measured using a surface contamination measuring instrument. n 1. Using various wiping materials, with and without clamps, and fixing the wiping method, wipe the contaminated areas on the surface of the experimental materials; use a surface contamination measuring instrument to determine the total β count rate on the wiping materials. n 2; Calculate the experimental material when using a surface contamination measuring instrument. 90 Sr- 90 Y wiping efficiency F Sr-Y The wiping efficiency calculated using the non-radioactive element rhenium was compared with that of the experimental materials. F Re and the use of radioactive elements 90 Sr- 90 Wiping efficiency calculated by Y measurement F Sr-Y Verification using rhenium to simulate radioactive nuclei 90 Sr- 90 Y studies the feasibility and accuracy of methods for improving the efficiency of surface contamination wiping. The clamped wiping method involves clamping the wiping material with a clamp, maintaining constant pressure, and wiping the surface of the experimental material slowly and uniformly. The clampless wiping method involves directly pressing the wiping material with your hand, maintaining constant pressure, and wiping the surface of the experimental material slowly and uniformly. The clampless wiping method is used for irregularly shaped experimental materials. The constant pressure is selected from 1 to 20 N, and the uniform speed is selected from 0.4 to 1.5 cm / s. The verification method in step 5) is to take 0.1~1.0 mL 90 Sr- 90 The Y standard solution was evenly coated onto the experimental material and placed in a fume hood or a well-ventilated, clean place for 1-3 days to air dry. The radionuclide content of the experimental material was then determined using a surface contamination analyzer. 90 Sr- 90 β total count rate of Y n 1. and radioactive nuclides on the wiping material. 90 Sr- 90 The total count rate of Y on β n 2, 90 Sr- 90 Y wiping efficiency F Sr-Y The calculation formula is: F Sr-Y = n 2 / n 1 ×100%; In step 2), the specified amount of rhenium standard solution is selected from ammonium perrhenate standard solution with a concentration of 100~500 μg / mL. When using it, take 0.1~1.0 mL of the solution and coat it evenly on the surface of the selected experimental material and let it stand to dry. The coating is done by using a liquid dispenser or a graduated tube to draw up the solution and then evenly apply it to the object. The standing to dry means placing it in a fume hood or a well-ventilated and clean place for 1-3 days to air dry naturally, which is the required contaminated sample.

2. The method of simulating radioactive nuclides using rhenium as described in claim 1 90 Sr- 90 Y is a method for studying the efficiency of surface contamination wiping, characterized by... The various wiping materials include dry filter paper, dry cotton cloth, wet filter paper, and wet cotton cloth; the moisture content of the wiping materials is 0.008 g / cm³. 2 —0.020 g / cm 2 .

3. The method of simulating radioactive nuclides using rhenium as described in claim 2 90 Sr- 90 Y is a method for studying the efficiency of surface contamination wiping, characterized by... When wiping the material with a clamp, use 20 mL of 5% nitric acid for immersion. When wiping the material directly by hand, use 60 mL of 5% nitric acid for immersion. Shake the solution several times during the immersion period to ensure that the rhenium on the material is completely dissolved in the solution.

4. The method of simulating radioactive nuclides using rhenium as described in claim 3. 90 Sr- 90 Y is a method for studying the efficiency of surface contamination wiping, characterized by... The main body of the clamp is a detachable river dam-shaped structure.

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