Anti-nuclide durability evaluation method for coating special for nuclear power

Abstract

The invention relates to an anti-nuclide durability evaluation method for a coating special for nuclear power. The method comprises the following steps: carrying out experimental evaluation on contamination resistance of the coating; carrying out experimental evaluation on the anti-aging performance of the coating in the simulated nuclear power environment; carrying out experimental evaluation on the adhesive force between the coating and the matrix concrete; carrying out experimental evaluation on the nuclide penetration resistance of the coating, and measuring the invasion depth of nuclide in the coating; and based on the experimental evaluation results, establishing a comprehensive evaluation index system, distributing weights according to importance, and comprehensively scoring the durability of the coating. According to the method, the multi-dimensional performance data is acquired, the comprehensive evaluation index system is established based on the evaluation result, the weight is distributed according to the importance, and the durability of the coating is comprehensively scored, so that comprehensive and quantitative evaluation of the anti-nuclide durability of the coating is realized, the defect that the optimal coating cannot be scientifically compared and selected due to the lack of an evaluation method is overcome, and the reliability of the anti-nuclide durability of the coating is improved. The efficiency and the safety of the decontamination work in the decommissioning stage of the nuclear power station are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a method for evaluating the durability of a coating for nuclear power plants. BACKGROUND

[0002] With the advancement of the decommissioning process of nuclear power plants, decontamination of concrete structures becomes a key link. However, nuclides are easily attached to the surface of concrete or diffuse through material penetration, which not only threatens the safe and stable operation of nuclear power plants, but also increases the risk of radiation exposure to workers. Therefore, it is necessary to study the anti-pollution technology of concrete in the early stage to reduce the penetration depth of pollutants. As an effective means to block the migration of nuclides, the durability of the coating for nuclear power plants directly affects the long-term stability of the protection effect. However, at present, the research on the durability of the anti-nuclide coating for nuclear power plants is very limited, and there is still a lack of a comprehensive method for evaluating the durability of the anti-nuclide coating. This leads to the inability to scientifically select the optimal coating, thereby restricting the efficiency and safety of the decontamination work during the decommissioning stage of nuclear power plants. SUMMARY

[0003] Therefore, it is necessary to provide a method for evaluating the durability of the anti-nuclide coating for nuclear power plants to solve the problem that there is still a lack of a comprehensive method for evaluating the durability of the anti-nuclide coating.

[0004] The present application provides a method for evaluating the durability of the anti-nuclide coating for nuclear power plants, which comprises:

[0005] experimentally evaluating the stain resistance of the coating;

[0006] experimentally evaluating the aging resistance of the coating in a simulated nuclear power environment;

[0007] experimentally evaluating the adhesion of the coating to the base concrete;

[0008] experimentally evaluating the nuclide penetration resistance of the coating and measuring the penetration depth of the nuclide in the coating;

[0009] Based on the experimental evaluation results, a comprehensive evaluation index system is established, the weights are allocated according to the importance, and the durability of the coating is comprehensively scored.

[0010] In one embodiment, the experimentally evaluating the stain resistance of the coating comprises:

[0011] a suspension is prepared by mixing ash and water in a mass ratio of 1:1 according to the national standard;

[0012] After brushing the suspension on the surface of the test plate, the cycle of drying, curing and rinsing is carried out in sequence;

[0013] Measure the reflection coefficient of the test plate before and after treatment and calculate the rate of decrease in reflection coefficient.

[0014] In one embodiment, the experimental evaluation of the coating's aging resistance under simulated nuclear power environment includes:

[0015] The test panel was placed in a xenon lamp aging test chamber with an average irradiance of 50 W / m². 2 Artificial accelerated aging was carried out under the conditions of target temperature 65℃, test chamber temperature 38℃, and relative humidity 40%-60%, and humidity coupling was simulated by spray wetting method;

[0016] The color difference change level, gloss loss rate, and adhesion reduction rate of the test panels after aging were measured.

[0017] Record the degree of powdering and peeling on the test plate surface.

[0018] In one embodiment, in the aging resistance performance evaluation, the color difference change level is divided into 0-5 levels and corresponding scores: level 0 100 points, level 1 80 points, level 2 60 points, level 3 40 points, level 4 20 points, and level 5 0 points.

[0019] The light loss rate is divided into five levels from 0 to 5, with corresponding scores: Level 0: 100 points, Level 1: 80 points, Level 2: 60 points, Level 3: 40 points, Level 4: 20 points, and Level 5: 0 points.

[0020] The adhesion degradation rate is scored as follows: <2.5% corresponds to 100 points, 2.5%-5% corresponds to 75 points, 5%-10% corresponds to 50 points, 10%-20% corresponds to 25 points, and >20% corresponds to 0 points.

[0021] In one embodiment, the experimental evaluation of the adhesion between the coating and the substrate concrete includes:

[0022] Cylindrical test columns were bonded to the coating surface using 504 adhesive. After the adhesive cured, a vertical tensile stress was applied at a rate of 1 MPa / s using an adhesion tester.

[0023] Record the destructive strength value and calculate the adhesion force according to the formula, where the destructive strength calculation formula is the ratio of the destructive force to the bottom area of ​​the test column.

[0024] In one embodiment, the experimental evaluation of the nuclide penetration resistance of the coating includes:

[0025] After coating the surface of the concrete specimen, the target non-radioisotope ions are accelerated to diffuse from the exposed surface to the interior by electromigration.

[0026] The sample was ground along the axial direction using a layered grinding equipment with an accuracy of 0.5 mm / layer, for a total of 10 grinding layers;

[0027] The content of non-radioactive isotope ions of the target in each depth layer was determined by X-ray fluorescence analysis, and the depth of radionuclide invasion was determined when the ion content was zero.

[0028] In one embodiment, the electromigration method includes:

[0029] The coated specimen is placed in the source liquid pool, so that the target non-radioactive isotope ions can penetrate more rapidly under the action of an electric field.

[0030] In one embodiment, establishing a comprehensive evaluation index system includes:

[0031] The following weightings are set: stain resistance performance index (20%), aging resistance performance index (30%), adhesion performance index (25%), and radionuclide penetration depth performance index (25%). The aging resistance performance index includes three sub-items: color difference, gloss loss rate, and adhesion reduction rate, each accounting for 10% of the weight.

[0032] In one embodiment, the comprehensive scoring includes:

[0033] The stain resistance performance is divided into 5 levels according to the rate of decrease in reflectance: ≤5% corresponds to 100 points, ≤10% corresponds to 75 points, ≤15% corresponds to 50 points, ≤20% corresponds to 25 points, and >20% corresponds to 0 points;

[0034] Concrete adhesion is classified into 5 levels according to strength value: >8MPa corresponds to 100 points, 6-8MPa corresponds to 75 points, 4-6MPa corresponds to 50 points, 2-4MPa corresponds to 25 points, and <2MPa corresponds to 0 points;

[0035] The depth of stratified grinding is divided into 5 levels according to the penetration depth: <1mm corresponds to 100 points, 1-2mm corresponds to 75 points, 2-3mm corresponds to 50 points, 3-4mm corresponds to 25 points, and >4mm corresponds to 0 points.

[0036] In one embodiment, the experimental evaluation of the nuclide penetration resistance of the coating further includes:

[0037] Cut a Φ100mm×200mm concrete specimen into a Φ100mm×50mm disc-shaped specimen;

[0038] Grind the cut surfaces of the specimen;

[0039] Based on 1.5kg / m 2 The coating amount is applied to the surface of the specimen to form the coating to be tested.

[0040] The aforementioned method for evaluating the radionuclide resistance durability of nuclear power plant-specific coatings involves conducting experimental assessments of the coating's contamination resistance, aging resistance under simulated nuclear power environments, adhesion to the substrate concrete, and resistance to radionuclide penetration. It also measures the depth of radionuclide penetration within the coating to obtain multi-dimensional performance data. Based on these assessment results, a comprehensive evaluation index system is established, assigning weights according to importance and comprehensively scoring the coating's durability. This method achieves a comprehensive and quantitative evaluation of the coating's radionuclide resistance durability, overcoming the shortcomings of lacking a scientific method for selecting the optimal coating. It effectively improves the efficiency and safety of decontamination work during the decommissioning phase of nuclear power plants. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a flowchart of a method for evaluating the nuclide resistance durability of a nuclear power plant-specific coating, as an example. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this specification are for illustrative purposes only and do not represent the only possible implementation.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0048] The following is combined Figure 1 This invention describes a method for evaluating the nuclide resistance durability of a nuclear power-specific coating.

[0049] like Figure 1 As shown, in one embodiment, a method for evaluating the nuclide resistance durability of a nuclear power plant-specific coating includes the following steps:

[0050] Step S110: Conduct an experimental evaluation of the coating's stain resistance.

[0051] A suspension was prepared using ash and water at a 1:1 mass ratio, as specified by national standards. After applying the suspension to the surface of the test panels, a cycle of drying, curing, and rinsing was performed. The reflectance coefficients of the test panels before and after treatment were measured, and the rate of decrease in reflectance coefficient was calculated. Under standard experimental conditions (23℃, 50% RH), ash as specified by national standards was used as the pollution source, and a suspension was prepared with water at a 1:1 mass ratio. Cured test panels were taken, and their initial reflectance coefficients were measured. The pollution source suspension was then evenly applied to the test panels with a brush, placed in a 60℃ oven for 30 minutes, removed, and left at room temperature for 2 hours. The panels were then placed on a test panel rack in a rinsing device and rinsed. This process was repeated for 24 hours as one cycle. After two cycles, the reflectance coefficients of the test panels after treatment were measured, and the rate of decrease in reflectance coefficient (X) was calculated.

[0052]

[0053] Wherein, A and B are the initial and post-treatment reflectance coefficients of the test plate, respectively. This calculation assesses the coating's anti-fouling ability by quantifying the degree of surface contamination residue, as shown in Table 1. The reflectance reduction rate is scored according to a grading standard of ≤5% corresponding to 100 points, ≤10% corresponding to 75 points, ≤15% corresponding to 50 points, ≤20% corresponding to 25 points, and >20% corresponding to 0 points, effectively reducing the risk of nuclides adhering to the coating surface.

[0054] Table 1 Evaluation Index System for Antifouling Coatings of Nuclear Power Plant Concrete

[0055]

[0056] Step S120: Experimentally evaluate the aging resistance of the coating under simulated nuclear power environment.

[0057] The test panels were placed in a xenon lamp aging test chamber and artificially accelerated aging was performed under conditions of an average irradiance of 50 W / m², a target temperature of 65℃, a test chamber temperature of 38℃, and a relative humidity of 40%-60%. A spray wetting method was used to simulate humidity coupling. The color difference change level, gloss loss rate, and adhesion reduction rate of the test panels after aging were measured, and the degree of powdering and peeling on the test panel surface was recorded. The test panels were placed in the xenon lamp aging test chamber for a specified time. The aging chamber settings were: average irradiance 50 W / m². 2 The target temperature is 65℃, the test chamber temperature is 38℃, and the surface is moistened with water spray, with a relative humidity of 40%~60%RH. The test panels are then removed and compared with a reference panel for color difference testing. The color change level is recorded and assessed. For gloss loss testing, the gloss values ​​of the stone panels before and after aging are recorded, and the gloss loss rate is calculated using the following formula:

[0058]

[0059] Where A0 is the gloss measurement value before aging, and A1 is the gloss measurement value after aging. Referring to Table 1, in the aging resistance performance evaluation, color difference change levels are divided into 0-5 grades with corresponding scores: Grade 0 100 points, Grade 1 80 points, Grade 2 60 points, Grade 3 40 points, Grade 4 20 points, and Grade 5 0 points; gloss loss rate levels are also divided into 0-5 grades with corresponding scores: Grade 0 100 points, Grade 1 80 points, Grade 2 60 points, Grade 3 40 points, Grade 4 20 points, and Grade 5 0 points; adhesion degradation rate is scored as follows: <2.5% corresponds to 100 points, 2.5%-5% corresponds to 75 points, 5%-10% corresponds to 50 points, 10%-20% corresponds to 25 points, and >20% corresponds to 0 points. This process uses multi-environment coupling to accelerate aging and simulate real service conditions, accurately characterizing the degradation behavior of coating color, gloss, and bonding strength.

[0060] Step S130: Experimentally evaluate the adhesion between the coating and the substrate concrete.

[0061] Cylindrical test columns were bonded to the coating surface using 504 adhesive. After the adhesive cured, a vertical tensile stress of 1 MPa / s was applied using an adhesion tester. The breaking strength value was recorded, and the adhesion strength was calculated using the formula, where the breaking strength is the ratio of the breaking force to the base area of ​​the test column. Under standard experimental conditions, cylindrical test columns were bonded to the test plate surface using 504 adhesive. After the adhesive was completely cured, the test plate was immediately subjected to a pull-out test using an automatic adhesion tester. During the test, a tensile stress was applied in the direction perpendicular to the plane of the test plate, and the tensile force was steadily increased at a rate of 1 MPa / s. The test should be completed within 90 seconds. Basis for breaking strength calculation:

[0062]

[0063] Where F is the destructive force in N, and A is the area of ​​the test column in mm². 2 Referring to Table 1, the adhesion strength value is scored according to the following grading standard: >8MPa corresponds to 100 points, 6-8MPa corresponds to 75 points, 4-6MPa corresponds to 50 points, 2-4MPa corresponds to 25 points, and <2MPa corresponds to 0 points. This process quantifies the interfacial bonding strength through tensile failure testing to prevent nuclides from penetrating through coating peel gaps.

[0064] Step S140: Experimentally evaluate the nuclide penetration resistance of the coating and measure the penetration depth of the nuclide in the coating.

[0065] Before the experiment, a Φ100mm×200mm concrete specimen was cut into Φ100mm×50mm disc-shaped specimens, and the cut surfaces were ground. The coating to be tested was applied to the surface of the specimen at a rate of 1.5 kg / m². After the coating was applied to the surface of the concrete specimen, the target non-radioactive isotope ions were accelerated to diffuse from the exposed surface to the interior using an electromigration method. The specimen was ground axially with a layer grinding equipment at an accuracy of 0.5 mm / layer, for a total of 10 layers. The content of the target non-radioactive isotope ions in each depth layer was determined by X-ray fluorescence analysis. The depth of radionuclide penetration was determined when the ion content was zero. The electromigration method involved placing the coated specimen in a source liquid pool to accelerate the penetration of the target non-radioactive isotope ions under the action of an electric field. Specifically, concrete specimens with a diameter of 100mm × 200mm were molded according to the target concrete mix proportion. After standard curing for 28 days, the specimens were removed, and 100mm × 50mm circular specimens were cut from them and ground using a grinder. Antifouling material was applied to the sides and one cut surface of the ground specimens. The coating thickness was in accordance with GB 18445-2012, "Cement-based Penetrating Crystalline Waterproofing Materials," and the coating thickness was 1.5 kg / m². 2 The coating process involved: accelerating the diffusion of target non-radioactive isotope ions from the exposed concrete surface inwards via electromigration; using a high-precision profile grinding machine for hardened concrete, the concrete was ground in layers at 0.5 mm / layer along the axial direction, starting from the end of the specimen in contact with the source liquid pool, for a total of 10 layers; X-ray fluorescence analysis was performed to test the content of target non-radioactive isotope ions in the concrete at different depths, and to analyze the penetration of non-radioactive isotope ions. Referring to Table 1, the penetration depth was scored according to a grading standard: <1 mm = 100 points, 1-2 mm = 75 points, 2-3 mm = 50 points, 3-4 mm = 25 points, and >4 mm = 0 points. This process, through accelerated electromigration and layer analysis, accurately measured the nuclide migration limit, directly evaluating the long-term barrier performance of the coating.

[0066] Step S150: Based on the above experimental evaluation results, establish a comprehensive evaluation index system, assign weights according to importance, and give a comprehensive score to the coating durability performance.

[0067] The following weightings are set: stain resistance (20%), aging resistance (30%), adhesion (25%), and radionuclide penetration depth (25%). The aging resistance index includes three sub-items: color difference, gloss loss rate, and adhesion degradation rate, each with a 10% weighting. Each index is quantified and scored according to the above-mentioned grading standards, and a weighted average is used to obtain the comprehensive coating durability score.

[0068] The effectiveness of the above method is further illustrated in detail through specific embodiments of the present invention.

[0069] Example 1:

[0070] The durability of the waterborne fluorocarbon-epoxy coating system was evaluated.

[0071] (1) A stain resistance test was conducted on the waterborne fluorocarbon-epoxy coating system. The results showed that the reflectivity reduction coefficient of the waterborne fluorocarbon-epoxy coating system was 1%, and the stain resistance level was IV. According to Table 1, this indicator was scored out of 100.

[0072] (2) Artificial aging tests were conducted on the waterborne fluorocarbon-epoxy coating system under coupled environments of irradiation, temperature, and humidity. The results showed that after aging for 1000 hours, the waterborne fluorocarbon-epoxy coating system exhibited grade 0 discoloration, grade 1 gloss loss, and an adhesion reduction rate of 2.37%. According to Table 1, the score for this indicator was 93.3 points.

[0073] (3) An adhesion test was conducted between the waterborne fluorocarbon-epoxy coating and the substrate concrete. The results showed that the adhesion between the waterborne fluorocarbon-epoxy coating system and the concrete was 7.75 MPa. According to Table 1, this indicator was scored 75 points.

[0074] (4) A layered grinding experiment was conducted on the waterborne fluorocarbon-epoxy coating system, and the content of target non-radioactive isotope ions in the concrete at different depths was analyzed by X-ray fluorescence. The depth of layered grinding was defined as the point where the ion content was 0. Experimental results: The layered grinding depth of the waterborne fluorocarbon-epoxy coating system was 1.65 mm. According to Table 1, the score for this indicator was 75 points.

[0075] (5) Based on the scores and weights of each indicator, the overall score of the durability performance of the waterborne fluorocarbon-epoxy coating system is 85.5 points, as shown in Table 2.

[0076] Table 2. Overall Score of Waterborne Fluorocarbon-Epoxy Coating System

[0077]

[0078]

[0079] Example 2:

[0080] The durability of the polyurea coating system was evaluated.

[0081] (1) A stain resistance test was conducted on the polyurea coating system. The results showed that the reflectivity reduction coefficient of the polyurea coating system was 1%, and the stain resistance level was IV. According to Table 1, this indicator was scored out of 100.

[0082] (2) Artificial aging tests were conducted on the polyurea coating system under coupled environments of irradiation, temperature, and humidity. The results showed that after aging for 1000 hours, the polyurea coating system exhibited level 5 discoloration, level 3 gloss loss, and an adhesion reduction rate of 17.79%. According to Table 1, this indicator was scored as 21.7 points.

[0083] (3) An adhesion test was conducted between the polyurea coating and the concrete substrate. The results showed that the adhesion between the polyurea coating system and the concrete was 6.40 MPa. According to Table 1, this indicator was scored 75 points.

[0084] (4) A layered grinding experiment was conducted on the polyurea coating system, and the content of target non-radioactive isotope ions in the concrete at different depths was analyzed by X-ray fluorescence. The depth of layered grinding was defined as the point where the ion content was 0. Experimental results: The layered grinding depth of the polyurea coating system was 1.22 mm. According to Table 1, the score for this indicator was 75 points.

[0085] (5) Based on the scores and weights of each indicator, the overall score of the durability performance of the polyurea coating system is 64.0 points, as shown in Table 3.

[0086] Table 3. Overall Score of Polyurea Coating System

[0087]

[0088] Example 3:

[0089] The durability of the waterborne fluorocarbon-acrylic coating system was evaluated.

[0090] (1) A stain resistance test was conducted on the water-based fluorocarbon-acrylic coating system. The results showed that the reflectivity reduction coefficient of the water-based fluorocarbon-acrylic coating system was 7%, and the stain resistance level was III. According to Table 1, the score for this indicator was 75 points.

[0091] (2) Artificial aging tests were conducted on the waterborne fluorocarbon-acrylic coating system under coupled environments of irradiation, temperature, and humidity. The results showed that after aging for 1000 hours, the waterborne fluorocarbon-acrylic coating system exhibited grade 0 discoloration, grade 2 gloss loss, and an adhesion reduction rate of 2.21%. According to Table 1, the score for this indicator was 86.7 points.

[0092] (3) An adhesion test was conducted between the waterborne fluorocarbon-acrylic coating and the substrate concrete. The results showed that the adhesion between the waterborne fluorocarbon-acrylic coating system and the concrete was 4.14 MPa. According to Table 1, this indicator was scored out of 50 points.

[0093] (4) A layered grinding experiment was conducted on the waterborne fluorocarbon-acrylic coating system, and the content of target non-radioactive isotope ions in the concrete at different depths was analyzed by X-ray fluorescence. The depth of layered grinding was defined as the point where the ion content was 0. Experimental results: The layered grinding depth of the waterborne fluorocarbon-acrylic coating system exceeded 5 mm. According to Table 1, the score for this indicator was 0.

[0094] (5) Based on the scores and weights of each indicator, the overall score of the durability performance of the waterborne fluorocarbon-acrylic coating system is 53.5 points, as shown in Table 4.

[0095] Table 4. Overall Score of Waterborne Fluorocarbon-Acrylic Coating System

[0096]

[0097] According to the evaluation method for the durability performance of coatings against radionuclides, the comprehensive durability scores of waterborne fluorocarbon-epoxy coating system, polyurea coating system, and waterborne fluorocarbon-acrylic coating system are 85.5, 64.0, and 53.5, respectively. After comparison, the waterborne fluorocarbon-epoxy coating system has the best durability performance, while the waterborne fluorocarbon-acrylic coating system has the worst durability performance. Therefore, the waterborne fluorocarbon-epoxy coating system should be given priority when applying radionuclides to nuclear power plants.

[0098] The aforementioned method for evaluating the radionuclide resistance durability of nuclear power plant-specific coatings involves conducting experimental assessments of the coating's contamination resistance, aging resistance under simulated nuclear power environments, adhesion to the substrate concrete, and resistance to radionuclide penetration. It also measures the depth of radionuclide penetration within the coating to obtain multi-dimensional performance data. Based on these assessment results, a comprehensive evaluation index system is established, assigning weights according to importance and comprehensively scoring the coating's durability. This method achieves a comprehensive and quantitative evaluation of the coating's radionuclide resistance durability, overcoming the shortcomings of lacking a scientific method for selecting the optimal coating. It effectively improves the efficiency and safety of decontamination work during the decommissioning phase of nuclear power plants.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for evaluating the durability of a coating dedicated to nuclear power against nuclides, characterized in that, The method comprises: experimental evaluation of the stain resistance of the coating; experimental evaluation of the aging resistance of the coating in a simulated nuclear power environment; experimental evaluation of the adhesion of the coating to the base concrete; experimental evaluation of the nuclide penetration resistance of the coating, and measurement of the depth of nuclide penetration in the coating; based on the results of the above experimental evaluations, a comprehensive evaluation index system is established, weights are assigned according to importance, and the durability of the coating is comprehensively scored.

2. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 1, characterized by, The experimental evaluation of the stain resistance of the coating comprises: a suspension is prepared by mixing ash and water in a mass ratio of 1:1 according to national standards; after brushing the suspension on the surface of the test plate, the test plate is subjected to a cycle of drying, curing and rinsing; the reflectance of the test plate before and after treatment is measured and the reflectance reduction rate is calculated.

3. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 1, characterized by, The experimental evaluation of the aging resistance of the coating in a simulated nuclear power environment comprises: The test panel was placed in a xenon lamp aging test chamber, and artificial accelerated aging was carried out under the conditions of an average irradiance of 50 W / m 2 , a target temperature of 65°C, a test chamber temperature of 38°C, a relative humidity of 40%-60%, and a spray wetting mode was used to simulate humidity coupling. determination of the color difference change level, light loss rate and adhesion reduction rate of the test plate after aging; recording the degree of surface powdering and peeling of the test plate.

4. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 3, characterized by, In the aging resistance performance evaluation, the color difference change level is divided into 0-5 levels and corresponding scores: 0 level 100 points, 1 level 80 points, 2 level 60 points, 3 level 40 points, 4 level 20 points, 5 level 0 points; the light loss rate is divided into 0-5 levels and corresponding scores: 0 level 100 points, 1 level 80 points, 2 level 60 points, 3 level 40 points, 4 level 20 points, 5 level 0 points; the adhesion reduction rate is scored according to <2.5% corresponding to 100 points, 2.5%-5% corresponding to 75 points, 5%-10% corresponding to 50 points, 10%-20% corresponding to 25 points, >20% corresponding to 0 points.

5. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 1, characterized by, The experimental evaluation of the adhesion of the coating to the base concrete comprises: a cylindrical test column is adhered to the surface of the coating using 504 adhesive, and after the adhesive is cured, a vertical tensile stress is applied at a rate of 1 MPa / s using an adhesion tester; the breaking strength value is recorded and the adhesion is calculated according to the formula, wherein the breaking strength calculation formula is the ratio of the breaking force to the bottom area of the test column.

6. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 1, characterized by, The experimental evaluation of the nuclide penetration resistance of the coating comprises: after coating the test piece with the coating, the target non-radioactive isotope ions are accelerated to diffuse from the exposed surface to the inside by the electromigration method; a layered grinding device is used to grind the sample along the axial direction with a precision of 0.5 mm per layer, and the total number of grinding layers is 10; the content of target non-radioactive isotope ions in each depth layer is determined by X-ray fluorescence analysis, and the depth of nuclide penetration is determined as the point where the ion content is zero.

7. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 6, characterized by, The electromigration method comprises: placing the test piece coated with the coating in a source liquid pool, and accelerating the penetration of the target non-radioactive isotope ions under the action of an electric field.

8. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 1, characterized by, The establishment of the comprehensive evaluation index system comprises: setting the stain resistance performance index weight to 20%, the aging resistance performance index weight to 30%, the adhesion index weight to 25%, and the nuclide penetration depth index weight to 25%, wherein the aging resistance performance index includes color difference, light loss rate and adhesion reduction rate, each accounting for 10% of the weight.

9. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to claim 8, characterized by, The comprehensive scoring comprises: The contamination resistance is divided into 5 grades according to the decrease rate of reflection coefficient: 100 points for ≤5%, 75 points for ≤10%, 50 points for ≤15%, 25 points for ≤20%, and 0 point for >20%; The concrete adhesion is divided into 5 grades according to the strength value: 100 points for >8MPa, 75 points for 6-8MPa, 50 points for 4-6MPa, 25 points for 2-4MPa, and 0 point for <2MPa; The delamination grinding depth is divided into 5 grades according to the penetration depth: 100 points for <1mm, 75 points for 1-2mm, 50 points for 2-3mm, 25 points for 3-4mm, and 0 point for >4mm.

10. The method for evaluating the durability of a nuclear power plant special coating against nuclides according to any one of claims 1 to 9, characterized in that, The experimental evaluation of the nuclide penetration resistance of the coating also includes: Cutting the Φ100mm×200mm concrete test piece into a Φ100mm×50mm round pie-shaped test piece; Grinding the cutting surface of the test piece; 1.5 kg / m 2 The coating amount is the amount of the coating to be measured applied to the surface of the test piece.

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