Performance quantitative evaluation test method for foam detergent for pressurized water reactor

Abstract

The invention relates to the technical field of foam decontaminants for pressurized water reactors, in particular to a performance quantitative evaluation test method for a foam decontaminant for a pressurized water reactor, which comprises the following steps: adding a turbid liquid solution of metal oxide particles into a stainless steel water tank, and after the metal oxide particles in the turbid liquid are uniformly deposited at the bottom of the water tank, carrying out quantitative evaluation test on the performance of the foam decontaminant for the pressurized water reactor; slowly discharging clean water at the bottom of the water tank through a water outlet at the bottom of the water tank, and drying residual water at the bottom of the water tank by using a hot-air blower; wiping the delimited area at the bottom of the water tank by using wiping cloth, and obtaining the deposition amount of the metal oxide in the delimited area by weighing the mass change of the wiping cloth before and after wiping; spraying a foam detergent into the water tank deposited with the metal oxide particles, after reacting for a period of time, washing the water tank by adopting high-pressure water, and wiping a delimited area at the bottom of the water tank by adopting wiping cloth, so as to obtain the residual quantity of the metal oxide at the bottom of the water tank; and comparing with the deposition amount to quantitatively obtain the decontamination performance of the foam decontaminant.

Description

Technical Field

[0001] The present invention relates to the technical field of foam detergents for pressurized water reactors, and particularly to a method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor. Background Art

[0002] In order to increase the utilization hours of pressurized water reactor nuclear power units, nuclear power plants strive to optimize the overhaul time of the units. The decontamination work of the reactor pool is one of the main tasks of the overhaul. At present in China, high-pressure water flushing plus manual wiping are mostly used for pool decontamination, and the foam detergent technology is only used in Ningde Nuclear Power.

[0003] The main deposits at the bottom of the reactor pool of a pressurized water reactor nuclear power plant are activated corrosion products (metal oxides mainly composed of Fe, Co, and Ni). These substances exist in the form of loose deposits. The peeling of these loose metal oxides from the bottom of the pool mainly relies on the shearing and peeling action of high-pressure water. However, during the stage of only using high-pressure water flushing, these peeled metal oxides will be redeposited in the areas that have been flushed clean, affecting the flushing effect. The foam detergent has limited ability to improve the peeling effect of high-pressure water on the deposits, but it has a coating effect on the peeled deposits, preventing these deposits from being redeposited in other areas at the bottom of the pool during the high-pressure water flushing process, enabling these deposits peeled by high-pressure water to be carried into the drain trough with the water flow, and improving the efficiency of high-pressure water flushing.

[0004] Therefore, the ability of the foam detergent to prevent the redeposition of peeled deposits is particularly important in industrial applications. In the research and development of the foam detergent for the reactor pool, there is currently no relevant standard for reference in evaluating the ability of the foam detergent to prevent the redeposition of deposits peeled by high-pressure water, nor is there a relevant quantitative test evaluation method. Summary of the Invention

[0005] In view of the above problems that during the stage of only using high-pressure water flushing, these peeled metal oxides will be redeposited in the areas that have been flushed clean, affecting the flushing effect, and the foam detergent has limited ability to improve the peeling effect of high-pressure water on the deposits but has a coating effect on the peeled deposits, the present invention is proposed.

[0006] Therefore, the object of the present invention is to provide a method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor.

[0007] To solve the above technical problems, the present invention provides the following technical solution: A method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor, including,

[0008] Add a suspension solution of metal oxide particles to a stainless - steel sink. After the metal oxide particles in the suspension are evenly deposited on the bottom of the sink, slowly drain the clear water at the bottom of the sink through the drain outlet at the bottom of the sink, and then use a hot air blower to dry the residual water at the bottom of the sink; Wipe the designated area at the bottom of the sink with a wiping cloth, and obtain the deposition amount of metal oxide in the designated area by weighing the change in the mass of the wiping cloth before and after wiping; Spray a foam detergent into the sink where metal oxide particles are deposited. After reacting for a period of time, raise the end far from the drain outlet at the bottom of the sink, and use high - pressure water to wash the sink. After the washing is completed, wipe the designated area at the bottom of the sink with a wiping cloth to obtain the residual amount of metal oxide at the bottom of the sink; By comparing with the deposition amount, quantitatively obtain the decontamination performance of the foam detergent.

[0009] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: the metal oxide is one or a mixture of magnetite, cobalt oxide, and nickel oxide.

[0010] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: the suspension is prepared with demineralized water, and the volume ratio of demineralized water to the mass of the metal oxide is 100 ml:1 g.

[0011] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: the wiping cloth is made of polyester fiber, and the wiping cloth needs to be dried and weighed to a constant weight before weighing.

[0012] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: the foam detergent is sprayed using a spray gun that can quantitatively monitor the flow rates of compressed air and foam liquid.

[0013] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: after the foam is sprayed, the standing time is 5 - 10 minutes.

[0014] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: during the high - pressure water flushing process, raise the end of the sink far from the discharge outlet so that the inclination angle of the sink is about 10 degrees.

[0015] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor according to the present invention, wherein: during the high - pressure water flushing process, divide the bottom of the sink into two sides, A and B. After side A is flushed, wait for 1 - 5 minutes and then flush side B.

[0016] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor of the present invention, after the high-pressure water flushing is completed, wiping cloths are used to take samples from sides A and B respectively.

[0017] As a preferred embodiment of the method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor of the present invention, an electronic analytical balance with a precision of 0.1 mg is used to weigh the wiping cloths.

[0018] Advantages of the present invention: By weighing the mass change of the wiping cloth before and after wiping, the deposition amount and residual amount of metal oxides in the defined area at the bottom of the water tank can be accurately obtained, thereby providing a quantitative evaluation method for the performance of the foam decontaminant. This method is more scientific and accurate than traditional qualitative evaluations, and helps to more accurately evaluate the effect of the foam decontaminant; A stainless steel water tank is used to simulate the environment in a pressurized water reactor, and a suspension solution of metal oxide particles is added to simulate the deposition of pollutants, making the experimental conditions closer to the actual situation and improving the reliability and applicability of the test results; The entire testing process includes steps such as deposition, spraying, flushing, and weighing, with simple operations, easy implementation, no need for complex equipment or high-cost inputs, and is convenient for rapid testing in the laboratory or on-site;

[0019] Due to the adoption of standardized operation procedures and precise measurement means, this method has good repeatability and can ensure the comparability of test results obtained at different times and locations; This method is not only applicable to the evaluation of the decontamination performance of metal oxides such as iron oxide, cobalt oxide, and nickel oxide, but also the types and proportions of metal oxides in the suspension can be adjusted as needed, making it applicable to other types of pollutants and having high versatility; Demineralized water is used to prepare the suspension, reducing the potential harm to the environment and the human body. At the same time, the method of high-pressure water flushing is adopted to avoid the use of chemical reagents and improve the safety of the experiment;

[0020] In summary, the present invention provides a scientific, accurate, simple to operate, safe and reliable method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor, which is of great significance for improving the R & D efficiency and application effect of the foam decontaminant. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is the overall schematic diagram of a method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor of the present invention.

[0023] Figure 2 This is a simplified schematic diagram of a test method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor according to the present invention.

[0024] Figure 3 This is a comparison photo of high-pressure water flushing and a wiping cloth after foam - high-pressure water flushing according to the present invention. Among them, a) is high-pressure water flushing, and b) is foam - high-pressure water flushing.

[0025] Reference numerals: 100, water tank; 200, drain outlet; 300, drain pipe; 400, drain valve. Detailed implementation manners

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given in conjunction with the drawings in the specification.

[0027] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0028] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selectively exclusive embodiment from other embodiments.

[0029] Furthermore, the present invention is described in detail in conjunction with schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally out of the general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0030] Embodiment 1

[0031] Refer to Figure 1 - Figure 3 , which is the first embodiment of the present invention, provides a test method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor, including determining the original deposition amount of Fe 3 O 4 at the bottom of the water tank 100;

[0032] Step 1: Prepare and set up the water tank 100

[0033] S1. Process a stainless - steel sink 100 with a size of 1m×1m×0.5m and a material of 316L. Leave a drain opening 200 in the middle of one side of the sink 100. A drain pipe 300 is fixedly connected to the drain opening 200, and a drain valve 400 is rotatably connected to the drain pipe 300, which is used to drain the water in the sink 100.

[0034] S2. Add a suspension solution of metal oxide particles to the stainless - steel sink 100. The suspension is prepared with demineralized water. The volume ratio of demineralized water to the mass of metal oxide is 100ml:1g. Weigh 10g of Fe3O4 powder and place it in a beaker, then add 1L of demineralized water and stir evenly to form a Fe 3 O 4 slurry.

[0035] S3. Pour the Fe 3 O 4 slurry into the sink 100 to make it evenly distributed at the bottom of the sink 100. After natural sedimentation for 10 minutes, slowly drain the upper layer of water through the water - discharge opening, suck out the residual water with an ear - pipette, and dry it with a hair dryer, so that Fe 3 O 4 adheres to the bottom of the sink 100.

[0036] Step 2: Weigh the wiping cloth

[0037] S1. Weigh the initial mass of a commercially available wiping cloth made of polyester fiber (for example, 3.6382g). The wiping cloth needs to be dried and weighed to a constant weight before weighing.

[0038] S2. After wetting the wiping cloth, wipe off the deposited Fe 3 O 4 powder within the designated area (0.5m in length and 0.25m in width).

[0039] S3. After waiting for the wiping cloth to dry naturally, weigh the wiping cloth (for example, 4.7417g).

[0040] Step 3: Calculate the deposition amount

[0041] S1. According to the mass change of the wiping cloth before and after, calculate that the original deposition amount of Fe 3 O 4 is 1.1035g (4.7417g - 3.6382g).

[0042] Example 2

[0043] Refer to Figure 1 - Figure 3 , for the first embodiment of the present invention, a quantitative evaluation test method for the performance of a foam decontaminant for a pressurized water reactor is provided, including the evaluation of the high - pressure water flushing effect;

[0044] Step 1: High-pressure water flushing

[0045] S1. To be close to the actual on-site working conditions, one end of the water tank 100 far from the drain outlet is elevated so that the inclination angle of the water tank 100 is about 10 degrees, facilitating the water to flow from the drain port 200 into the drain pipe 300 and be discharged through the opening of the drain valve 400.

[0046] S2. During the high-pressure water flushing process, the bottom of the water tank 100 is evenly divided into sides A and B. After side A is flushed and waited for 1 - 5 minutes, then side B is flushed. Using a high-pressure water gun (the water outlet pressure is about 0.4 MPa), first conduct high-pressure water flushing on side A of the water tank 100, and then flush the water tank 100 with tap water.

[0047] Step 2: Wiping cloth sampling

[0048] S1. Weigh the initial mass of a commercially available wiping cloth made of polyester fiber (for example, 3.6635 g). The wiping cloth needs to be dried and have a constant weight before weighing.

[0049] S2. Wipe off the deposited Fe 3 O 4 powder in the designated area (0.5 m long and 0.25 m wide). After the wiping cloth dries naturally in the shade, weigh the mass (for example, 3.7010 g).

[0050] Step 3: Calculate the residual amount

[0051] S1. According to the mass change of the wiping cloth before and after, calculate that the residual amount of Fe 3 O 4 is 0.0375 g (3.7010 g - 3.6635 g).

[0052] Step 4: Evaluate the redeposition amount

[0053] S1. Then repeat the high-pressure water flushing and water flushing on side B of the water tank 100.

[0054] S2. Conduct wiping sampling again in the designated area on side A to obtain that the redeposition amount of Fe 3 O 4 in the area on side A is 0.0415 g.

[0055] Example 3

[0056] Reference Figure 1 - Figure 3 , for the first embodiment of the present invention, provides a method for quantitatively evaluating the performance of a foam decontaminant for a pressurized water reactor, including evaluating the foam decontamination effect;

[0057] Step 1: Foam spraying

[0058] S1. Since 10 g of Fe 3 O 4 powder was weighed and placed in a beaker, and 1 L of water was added and stirred evenly to form a Fe3O4 slurry.

[0059] S2. The Fe 3 O 4 slurry was poured into the water tank 100, and it was evenly distributed at the bottom of the water tank 100. After natural sedimentation for 10 minutes, the upper layer of water was slowly discharged through the water outlet, the residual water was sucked out with an ear syringe, and it was dried with a hair dryer, so that Fe 3 O 4 adhered to the bottom of the water tank 100.

[0060] S3. Then, a foam cleaning agent was sprayed into the stainless-steel water tank 100 with a foam spray gun, so that a layer of foam cleaning liquid was evenly sprayed on the entire bottom of the water tank 100. Among them, the spraying of the foam cleaning agent used a spray gun that could quantitatively monitor the flow rates of compressed air and foam liquid.

[0061] S4. After the foam was sprayed, it was left standing for 5 - 10 minutes.

[0062] Step 2: High-pressure water rinsing

[0063] S1. Using a high-pressure water gun (the water outlet pressure is about 0.4 MPa), first perform high-pressure water rinsing on the A side of the water tank 100; then use a wiping cloth (the initial mass is, for example, 3.6510 g) to wipe off the deposited Fe 3 O 4 powder in the designated area (0.5 m long and 0.25 m wide). After the wiping cloth was naturally air-dried, its mass was weighed (for example, 3.6669 g), and an electronic analytical balance with a precision of 0.1 mg was used to weigh the wiping cloth.

[0064] Step 3: Calculating the residual amount

[0065] S1. According to the mass change of the wiping cloth before and after, it was calculated that the residual amount of Fe 3 O 4 was 0.0159 g (3.6669 g - 3.6510 g).

[0066] Step 4: Re-deposition amount evaluation

[0067] S1. Then, the high-pressure water rinsing and water rinsing were repeated on the B side of the water tank 100.

[0068] S2. Wiping and sampling were performed again in the designated area on both sides of A, and the re-deposition amount of Fe 3 O 4 in the area on the A side was 0.0064 g.

[0069]

[0070] Table 1 Quality change of the wiping cloth during decontamination by water flushing and foam flushing

[0071] In summary, regarding the effect of using a high-pressure water gun and foam cleaning to decontaminate the Fe3O4 powder deposited at the bottom of the stainless-steel sink 100, first, the Fe 3 O 4 powder is mixed with water and allowed to naturally precipitate in the sink 100 to form a sediment layer. Then, a high-pressure water gun and a foam gun are respectively used to clean the sediment, and the cleaning effect is evaluated by measuring the quality change of the wiping cloth. The results show that after high-pressure water flushing, the residual amount of Fe 3 O 4 is 0.0375 g, and the redeposition amount is 0.0415 g; after foam cleaning, the residual amount of Fe 3 O 4 is 0.0159 g, and the redeposition amount is 0.0064 g. This indicates that the foam cleaning method is more effective in removing Fe 3 O 4 deposits and has a lower redeposition amount.

[0072] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who refer to this disclosure should easily understand that many modifications are possible (for example, changes in the dimensions, scales, structures, shapes, and proportions of various elements, as well as parameter values, installation arrangements, use of materials, colors, orientations, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature, number, or position of discrete elements may be altered or changed. Therefore, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures that perform the recited function herein, and not only structurally equivalent but also equivalent structures. Other substitutions, improvements, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the present invention is not limited to specific embodiments but extends to various modifications that still fall within the scope of the appended claims.

[0073] In addition, to provide a concise description of the exemplary embodiments, not all features of the actual embodiments may be described (i.e., those features that are not relevant to the currently contemplated best mode of carrying out the invention or those features that are not relevant to implementing the invention).

[0074] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A test method for quantitatively evaluating the performance of a foam detergent for a pressurized water reactor, characterized in that: A suspension solution of metal oxide particles is added to a stainless steel water tank. After the metal oxide particles in the suspension are uniformly deposited at the bottom of the water tank, the clean water at the bottom of the water tank is slowly discharged through the drain at the bottom of the water tank, and then the residual water at the bottom of the water tank is blown dry with a hot air blower; a designated area at the bottom of the water tank is wiped with a wiping cloth, and the amount of metal oxide deposited in the designated area is obtained by weighing the mass change of the wiping cloth before and after wiping; a foam detergent is sprayed into the water tank where the metal oxide particles are deposited, and after a period of reaction, the end away from the drain at the bottom of the water tank is raised, and the water tank is rinsed with high-pressure water. After the rinsing is completed, the designated area at the bottom of the water tank is wiped with a wiping cloth to obtain the residual amount of metal oxide at the bottom of the water tank; and the decontamination performance of the foam detergent is quantitatively obtained by comparing with the deposition amount.

2. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 1, characterized in that: The metal oxide is a mixture of one or more of ferroferric oxide, cobalt oxide and nickel oxide.

3. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 2, characterized in that: The suspension is prepared using deionized water, and the mass ratio of the volume of the deionized water to the metal oxide is 100 ml:1 g.

4. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 2 or 3, characterized in that: The wiping cloth is made of polyester fiber and needs to be dried and weighed constantly before weighing.

5. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 4, characterized in that: The foam detergent is sprayed using a spray gun that can quantitatively monitor the flow of compressed air and foam liquid.

6. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 5, characterized in that: After spraying the foam, let it sit for 5 to 10 minutes.

7. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 6, characterized in that: During the high-pressure water flushing process, the end of the water tank away from the discharge outlet is raised so that the inclination angle of the water tank is about 10 degrees.

8. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 7, characterized in that: During the high-pressure water flushing process, the bottom of the sink is evenly divided into two sides, A and B. After flushing side A, wait 1 to 5 minutes before flushing side B.

9. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 8, characterized in that: After high-pressure water washing, use a wiping cloth to sample the A and B sides respectively.

10. The test method for quantitative evaluation of performance of foam detergent for pressurized water reactor according to claim 5, characterized in that: The wipes were weighed using an electronic analytical balance with an accuracy of 0.1 mg.

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