Degradable chemical decontamination formula for radioactive waste liquid evaporator and use method

Abstract

The invention discloses a degradable chemical decontamination formula for a radioactive waste liquid evaporator and a use method, and particularly relates to the following steps: preparing a decontamination solution for decontamination of the radioactive waste liquid evaporator; a decontamination solution is injected into the radioactive waste liquid evaporator, and the interior of the radioactive waste liquid evaporator is decontaminated through the decontamination solution; the decontamination time of the radioactive waste liquid evaporator is obtained, when the decontamination time reaches a preset decontamination time threshold value, decontamination waste liquid in the radioactive waste liquid evaporator is discharged, and deionized water is used for flushing the interior of the radioactive waste liquid evaporator; and carrying out degradation treatment on the decontamination waste liquid by using an oxidizing agent. The decontamination solution suitable for the radioactive waste liquid evaporator is prepared, and the organic decontamination waste liquid after decontamination is subjected to inorganic treatment by using the oxidizing agent, so that the problem that a large amount of radioactive organic waste water generated after the implementation of the decontamination process of the radioactive waste liquid evaporator is difficult to treat is solved while sediments and corrosives in equipment are removed.

Description

Technical Field

[0001] The present application relates to the field of nuclear fuel technology, and in particular to a degradable chemical decontamination formula and a method of use for a radioactive waste liquid evaporator. Background Art

[0002] At present, evaporation technology is usually used to treat radioactive waste liquid, which mainly involves sending the radioactive waste liquid into a radioactive waste liquid evaporator. The radioactivity of the steam evaporated from the radioactive waste liquid in the radioactive waste liquid evaporator is reduced, and it can be directly discharged after cooling and condensation. The volume of the concentrated liquid remaining after the evaporation of the radioactive waste liquid will be greatly reduced, and it will be stored after solidification treatment, thereby reducing the storage volume of the radioactive waste liquid and facilitating subsequent transportation. However, after the radioactive waste liquid evaporator has been used for a period of time, a lot of dirt will accumulate inside, resulting in a decrease in the working efficiency of the radioactive waste liquid evaporator. Summary of the invention

[0003] In view of this, the present application provides a degradable chemical decontamination formula and method for use in a radioactive waste liquid evaporator. The main purpose is to solve the technical problem in the prior art that after a radioactive waste liquid evaporator has been used for a period of time, a lot of dirt will accumulate inside, resulting in a decrease in the working efficiency of the evaporator.

[0004] According to the first aspect of the present application, a degradable chemical decontamination formula and a method of use for a radioactive waste liquid evaporator are provided, the method comprising:

[0005] Prepare decontamination fluid for decontamination of radioactive waste evaporators;

[0006] injecting a decontamination liquid into the radioactive waste liquid evaporator, and using the decontamination liquid to decontaminate the inside of the radioactive waste liquid evaporator;

[0007] Obtaining the decontamination time of the radioactive waste liquid evaporator, and when the decontamination time reaches a preset decontamination time threshold, discharging the decontamination waste liquid in the radioactive waste liquid evaporator, and flushing the inside of the radioactive waste liquid evaporator with deionized water;

[0008] Use oxidants to degrade the decontamination waste liquid.

[0009] Optionally, the step of injecting the decontamination liquid into the radioactive waste liquid evaporator and using the decontamination liquid to decontaminate the inside of the radioactive waste liquid evaporator specifically includes:

[0010] injecting the decontamination liquid into the radioactive waste liquid evaporator;

[0011] The centrifugal pump in the radioactive waste liquid evaporator is started and controlled to run at a preset speed so that the decontamination liquid circulates inside the radioactive waste liquid evaporator to decontaminate the inside of the radioactive waste liquid evaporator.

[0012] Optionally, the step of using an oxidant to degrade the decontamination waste liquid specifically includes:

[0013] injecting an oxidant into the discharged decontamination waste liquid;

[0014] The decontamination waste liquid is heated according to a preset temperature and a preset time, and the organic matter in the decontamination waste liquid is degraded by an oxidant;

[0015] The degraded decontamination waste liquid is discharged into the wastewater treatment system.

[0016] Optionally, the raw materials of the decontamination liquid include, by weight: 19 to 37 parts of inorganic acid, 3 to 6 parts of complexing agent, 0.5 to 1.5 parts of sustained-release agent, 0 to 1.0 parts of surfactant, and the balance is deionized water.

[0017] Optionally, the inorganic acid comprises at least one of: hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid;

[0018] The complexing agent comprises at least one of the following: sodium ethylenediaminetetramethylenephosphate, diethylenetriaminepenta(methylenephosphonate), disodium ethylenediaminetetraacetate, tetrasodium iminodisuccinate and fatty alcohol polyoxyethylene ether;

[0019] The sustained-release agent comprises at least one of the following: citric acid, polyaspartic acid, triethanolamine, ferrous sulfate, ferrous nitrate, and ammonium thioacetate;

[0020] The surfactant includes at least one of cetyltrimethylammonium bromide, cetylpentyldimethylammonium bromide, polyacrylamide, sodium dodecylbenzene sulfonate and sodium dodecylbenzene sulfonate.

[0021] Optionally, the step of preparing a decontamination liquid for decontaminating a radioactive waste liquid evaporator specifically comprises:

[0022] Pour deionized water into the container;

[0023] Add a complexing agent, an inorganic acid, a slow-release agent and a surfactant into a container in sequence and stir to obtain a cleaning solution.

[0024] Optionally, the preset decontamination time threshold is 20 minutes to 40 minutes.

[0025] Optionally, the preset rotation speed of the centrifugal pump is 2 m / s to 5 m / s.

[0026] Optionally, the oxidant is hydrogen peroxide; the amount of the oxidant added is 0.5% to 1.5% of the decontamination waste liquid.

[0027] Optionally, the preset temperature of the degradation operation is 50 degrees Celsius to 70 degrees Celsius; the preset time of the degradation operation is 10 minutes to 40 minutes.

[0028] By means of the above technical scheme, the present application provides a degradable chemical decontamination formula and method of use for a radioactive waste liquid evaporator. Specifically, a decontamination liquid suitable for a radioactive waste liquid evaporator is prepared in advance. The prepared decontamination liquid can efficiently complete the chemical decontamination of the radioactive waste liquid evaporator, reduce the radioactive pollutants inside the equipment, reduce the radioactive hazards of operators and the environment, and remove the sediments and corrosive substances inside the equipment, maintain its operating efficiency and performance, reduce equipment failures, corrosion and wear caused by sediments inside the equipment, and extend the service life of the equipment. Afterwards, an oxidant is used to inorganically treat the decontaminated organic decontamination waste liquid, which solves the problem of a large amount of radioactive organic wastewater being difficult to treat after the decontamination process of the radioactive waste liquid evaporator is implemented, reduces the burden on the environment and subsequent treatment systems, and improves the overall waste treatment effect.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0031] Figure 1 A schematic diagram of a degradable chemical decontamination formula and a method of using the degradable chemical decontamination formula for a radioactive waste liquid evaporator provided in an embodiment of the present application is shown;

[0032] Figure 2 A schematic diagram of another degradable chemical decontamination formulation and use method for a radioactive waste liquid evaporator provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0034] The present application embodiment provides a degradable chemical decontamination formula and use method for a radioactive waste liquid evaporator, such as Figure 1 As shown, the method includes:

[0035] S101. Prepare decontamination liquid for decontamination of radioactive waste liquid evaporator.

[0036] The degradable chemical decontamination formula and method of use for the radioactive waste liquid evaporator provided in the embodiment of the present application are mainly used in the scenarios of in-service decontamination or decommissioning decontamination of the radioactive waste liquid evaporator. Among them, the radioactive waste liquid evaporator is used to concentrate nuclear power high-level radioactive waste liquid. After the radioactive waste liquid evaporator has been in operation for a period of time, its inner wall and corresponding components will be contaminated by radioactivity, and it is necessary to decontaminate them for equipment reuse, or when the equipment enters the decommissioning stage, the radioactive waste liquid evaporator needs to be decontaminated for subsequent effective disposal.

[0037] Before decontaminating the radioactive waste liquid evaporator, the concentration and composition of the decontamination liquid are determined based on the pollutants in the waste liquid in the radioactive waste liquid evaporator, so as to prepare the decontamination liquid so that it is more targeted and efficient for the pollutants in the radioactive waste liquid, and can effectively remove sediments and dirt, improve decontamination efficiency, control the decontamination process, reduce equipment damage, enhance safety, meet environmental protection requirements, and improve economic benefits.

[0038] S102, injecting the decontamination liquid into the radioactive waste liquid evaporator, and using the decontamination liquid to decontaminate the inside of the radioactive waste liquid evaporator.

[0039] S103, obtaining the decontamination time of the radioactive waste liquid evaporator, and when the decontamination time reaches a preset decontamination time threshold, discharging the decontamination waste liquid in the radioactive waste liquid evaporator, and flushing the inside of the radioactive waste liquid evaporator with deionized water.

[0040] In steps S102 and S103, the prepared decontamination liquid is injected into the radioactive waste liquid evaporator to ensure that the decontamination liquid can fully cover all areas in the equipment that need to be decontaminated. The action time of the decontamination liquid in the radioactive waste liquid evaporator is recorded. When the decontamination time reaches the preset decontamination time threshold, the decontamination is stopped, the decontamination waste liquid is discharged from the equipment, and the discharged decontamination waste liquid is collected in an appropriate container. Thereafter, a large amount of deionized water is injected into the radioactive waste liquid evaporator for flushing to remove the residual decontamination waste liquid and residues, and the flushing water is discharged and collected in a special container to ensure that all decontamination waste liquid and residues can be completely removed.

[0041] Optionally, a preset decontamination time threshold may be set according to the composition and concentration of the decontamination liquid and the material of the evaporator and its ability to resist acid and alkali corrosion.

[0042] S104, using an oxidant to degrade the decontamination waste liquid.

[0043] In this step, radioactive organic waste liquid will be produced after decontamination. The organic decontamination waste liquid after decontamination is degraded inorganically by using an oxidant, which can convert the organic matter in the organic waste liquid into stable inorganic matter, reduce the volatility and biodegradability of these substances, reduce the burden on the environment and subsequent treatment systems, and improve the overall waste treatment effect.

[0044] The degradable chemical decontamination formula and method of use for the radioactive waste liquid evaporator provided in the embodiment of the present application is to prepare a decontamination liquid suitable for the radioactive waste liquid evaporator in advance, and the prepared decontamination liquid can efficiently complete the chemical decontamination of the radioactive waste liquid evaporator, reduce the radioactive pollutants inside the equipment, reduce the radioactive hazards of operators and the environment, and remove the sediments and corrosive substances inside the equipment, maintain its operating efficiency and performance, reduce equipment failures, corrosion and wear caused by sediments inside the equipment, and extend the service life of the equipment. Afterwards, the organic decontamination waste liquid after decontamination is inorganically treated with an oxidant, which solves the problem of a large amount of radioactive organic wastewater being difficult to treat after the decontamination process of the radioactive waste liquid evaporator is implemented, reduces the burden on the environment and subsequent treatment systems, and improves the overall waste treatment effect.

[0045] The present application further provides another degradable chemical decontamination formula and method for use in a radioactive waste liquid evaporator as a refinement and expansion of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process of the present embodiment, such as Figure 2 As shown, the method includes:

[0046] S201. Prepare a decontamination solution for decontaminating a radioactive waste liquid evaporator.

[0047] This step and Figure 1 The method of step S101 shown is the same and will not be repeated here.

[0048] Optionally, the raw materials of the decontamination liquid include, by weight: 19 to 37 parts of inorganic acid, 3 to 6 parts of complexing agent, 0.5 to 1.5 parts of sustained-release agent, 0 to 1.0 parts of surfactant, and the balance is deionized water. The decontamination liquid is prepared using inorganic acid, complexing agent, sustained-release agent and surfactant as raw materials. The inorganic acid can effectively dissolve inorganic deposits (such as calcium deposits and rust, etc.) inside the radioactive waste liquid evaporator to prevent the deposits from affecting the performance of the equipment; the complexing agent can dissolve and remove metal ions from the surface to avoid the regeneration of deposits; the sustained-release agent can control the release rate of the decontamination liquid so that it can play a role in a long-term and stable manner during the decontamination process, avoid damage to the equipment caused by excessively fast chemical reactions, and ensure that the decontamination liquid works effectively for a long time; the surfactant can reduce the surface tension of the liquid, enhance the wettability and permeability of the decontamination liquid, and make the decontamination liquid more effectively penetrate into the dirt and sediments. The decontamination formula can effectively remove sediment and dirt, improve decontamination efficiency, control the decontamination process, reduce equipment damage, enhance safety, meet environmental protection requirements, and improve economic benefits.

[0049] Optionally, the inorganic acid includes at least one of the following: hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid; the complexing agent includes at least one of the following: sodium ethylenediaminetetramethylene phosphate (EDTMPS), diethylenetriaminepenta(methylene phosphonate) (DETPMPS), disodium ethylenediaminetetraacetate (EDTA), tetrasodium iminodisuccinate (IDS) and fatty alcohol polyoxyethylene ether (JFC); the sustained-release agent includes at least one of the following: citric acid, polyaspartic acid, triethanolamine, ferrous sulfate, ferrous nitrate and ammonium thioacetate; the surfactant includes at least one of the following: hexadecyltrimethylammonium bromide (CTAB), hexadecylpentyldimethylammonium bromide (DDAC), polyacrylamide, sodium dodecylbenzene sulfonate and sodium dodecylbenzene sulfonate (SDBS). The decontamination formula process has low toxicity, no odor, low corrosiveness, and low comprehensive decontamination cost. The reagents used are industrial products, which are cheap, easy to purchase, and generate less waste. The formula does not contain harmful ions that affect the wastewater treatment system and is compatible with the wastewater treatment system.

[0050] In an embodiment of the present application, optionally, in order to prepare an efficient decontamination liquid, in step S201, a decontamination liquid for decontamination of a radioactive waste liquid evaporator is prepared, specifically including: pouring deionized water into a container; adding a chelating agent, an inorganic acid, a sustained-release agent and a surfactant to the container in sequence and stirring to obtain a decontamination liquid.

[0051] In this embodiment, when preparing the decontamination liquid, first pour deionized water into the stainless steel container for preparing the decontamination liquid. Deionized water is the basic solvent of the decontamination liquid and can effectively dissolve the reagents added later. Thereafter, according to the formula requirements of the decontamination liquid, weigh appropriate amounts of complexing agent, inorganic acid, sustained-release agent and surfactant. Add the complexing agent, inorganic acid, sustained-release agent and surfactant in sequence. When adding each reagent, stir it thoroughly for 10 minutes before adding the next reagent to ensure that the reagent is evenly distributed and fully mixed with other ingredients.

[0052] By means of the above method, a decontamination liquid suitable for a radioactive waste liquid evaporator can be effectively prepared, and its effectiveness and safety in practical applications can be ensured.

[0053] S202. Inject the decontamination liquid into the radioactive waste liquid evaporator.

[0054] S203, starting the centrifugal pump in the radioactive waste liquid evaporator, and controlling the centrifugal pump to run at a preset speed, so that the decontamination liquid circulates inside the radioactive evaporator to decontaminate the inside of the radioactive waste liquid evaporator.

[0055] In steps S202 and S203, after the prepared decontamination liquid is injected into the radioactive waste liquid evaporator, the centrifugal pump is started and controlled to run at a preset speed so that the decontamination liquid can circulate inside the radioactive evaporator to ensure that the decontamination liquid evenly covers all parts inside the equipment, thereby achieving decontamination of the inside of the radioactive waste liquid evaporator.

[0056] Optionally, the preset speed of the centrifugal pump is 2 m / s to 5 m / s, such as 2 m / s, 3 m / s, etc. Setting an appropriate speed can increase the flow rate of the decontamination liquid, help to evenly distribute the decontamination liquid inside the equipment, ensure the effective circulation of the decontamination liquid inside the evaporator, so that the decontamination liquid can fully contact all contaminated areas, reduce the situation of local accumulation of liquid, and improve the decontamination effect.

[0057] S204, obtaining the decontamination time of the radioactive waste liquid evaporator, and when the decontamination time reaches a preset decontamination time threshold, discharging the decontamination waste liquid in the radioactive waste liquid evaporator, and flushing the inside of the radioactive waste liquid evaporator with deionized water.

[0058] In this step, the timing starts when the centrifugal pump is activated to obtain the decontamination time of the radioactive waste liquid evaporator. When the decontamination time reaches the set time, the centrifugal pump is stopped and the stop time is recorded. Thereafter, the decontamination waste liquid inside the evaporator is emptied into a stainless steel container, and the inside of the evaporator is rinsed clean with deionized water.

[0059] Optionally, the preset decontamination time threshold is 20 minutes to 40 minutes, such as 20 minutes, 25 minutes, 30 minutes, etc. Setting an appropriate decontamination time threshold can ensure that the reaction between the decontamination liquid and the sediment is fully carried out, and ensure that the radioactive or contaminated substances inside the device are effectively removed.

[0060] Optionally, the decontamination process has excellent decontamination performance, and the decontamination factor is as high as 80 or more. After the decontamination is completed, the decontamination factor is calculated and the decontamination effect is tested. If the decontamination effect is not ideal (such as the decontamination factor does not reach 80), the decontamination liquid ratio and decontamination time are adjusted, and the radioactive waste liquid evaporator is decontaminated again until the decontamination effect meets the standard.

[0061] Through the above method, chemical decontamination of the radioactive waste liquid evaporator is achieved, the radioactive pollutants inside the equipment are reduced, the radioactive risks to operators and the environment are reduced, and at the same time, the sediments and corrosive substances inside the equipment are removed, its operating efficiency and performance are maintained, and equipment failures, corrosion and wear caused by sediments inside the equipment are reduced, thereby extending the service life of the equipment.

[0062] S205. Inject an oxidant into the discharged decontamination waste liquid.

[0063] S206, heating the decontamination waste liquid at a preset temperature and a preset time, and degrading organic matter in the decontamination waste liquid by an oxidant.

[0064] S207, discharging the degraded decontamination waste liquid into the wastewater treatment system.

[0065] In steps S205 to S207, an appropriate amount of oxidant is injected into the decontamination waste liquid in the stainless steel container, and the decontamination waste liquid is heated to a preset temperature and continuously heated for a preset time, so that the oxidant degrades the organic matter in the decontamination waste liquid. When the reaction time reaches the preset time. The reaction is completed, the heating device is turned off, and the decontamination waste liquid is cooled to room temperature. Thereafter, the degraded decontamination waste liquid is discharged into the wastewater treatment system. Ensure that the waste liquid discharge complies with the regulations to avoid environmental pollution.

[0066] Optionally, the oxidant can be hydrogen peroxide, which is a strong oxidant that can effectively oxidize and decompose organic pollutants and complex compounds in waste liquid, and the main products after decomposition of hydrogen peroxide are water and oxygen, which are harmless to the environment and can reduce the environmental burden compared to other chemical oxidants. In addition, hydrogen peroxide is cheap and has low cost of use, which can effectively reduce the cost of waste liquid treatment. Furthermore, the amount of oxidant added is 0.5%-1.5% of the decontamination waste liquid. That is, when mixing the decontamination waste liquid and hydrogen peroxide, the mass of hydrogen peroxide should account for 0.5%-1.5% of the total mass of the decontamination waste liquid, such as 0.5%, 1%, 1.5%, etc. By selecting a suitable oxidant and controlling the amount added, the reaction rate can be controlled, the reaction efficiency can be improved, and the degradation effect can be effectively improved.

[0067] Optionally, the preset temperature of the degradation operation is 50 degrees Celsius to 70 degrees Celsius, such as 50 degrees Celsius, 55 degrees Celsius, 60 degrees Celsius, etc. By setting an appropriate reaction temperature, it is helpful to mix the waste liquid and the oxidant, making the reaction process more uniform, enhancing the degradation activity, and improving the removal efficiency of the oxidant for organic matter. Further, the preset time of the degradation operation is 10 minutes to 40 minutes, such as 10 minutes, 20 minutes, 30 minutes, etc. By setting an appropriate reaction time, it is ensured that there is enough time to complete the degradation of the organic matter, avoid insufficient reaction, prevent excessive treatment, and avoid excessive oxidation or other negative effects caused by too long reaction time.

[0068] Through the above method, inorganic treatment of the organic decontamination waste liquid after decontamination is achieved, solving the problem that a large amount of radioactive organic waste water will be generated and difficult to treat after the current radioactive waste liquid evaporator decontamination process is implemented, and the organic matter in the decontamination waste liquid can be efficiently degraded, and the degradation rate of organic matter in the decontamination waste liquid within 0.5 hours can reach more than 98%. In addition, the steps are simple, the conditions are mild, and the implementation conditions are easy to achieve, which is suitable for radioactive on-site implementation and is conducive to reducing the radioactive exposure dose of operators.

[0069] In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. The raw materials used in the embodiments and comparative examples are all commercially available.

[0070] Embodiment 1:

[0071] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 1:

[0072]

[0073] Table 1

[0074] Step 2: Chemical decontamination: Inject the decontamination liquid into the radioactive waste liquid evaporator without heating, and circulate the decontamination liquid using a centrifugal pump with a flow rate of 2.5m / s and a decontamination time of 20mins. After the decontamination is completed, drain the decontamination waste liquid, and then rinse the radioactive waste liquid evaporator with deionized water to complete the decontamination. Use a portable surface contamination meter to measure the surface dose of the radioactive waste liquid evaporator, and use an electronic balance to obtain its mass loss, and calculate the decontamination factor and corrosion depth.

[0075] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0076] Comparative Example 1:

[0077] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 2:

[0078]

[0079] Table 2

[0080] Step 2: Chemical decontamination: Inject the decontamination liquid into the radioactive waste liquid evaporator without heating, and circulate the decontamination liquid using a centrifugal pump with a flow rate of 2.5m / s and a decontamination time of 20mins. After the decontamination is completed, drain the decontamination waste liquid and rinse it with deionized water to complete the decontamination. Use a portable surface contamination meter to measure the surface dose of the radioactive waste liquid evaporator, and use an electronic balance to obtain its mass loss, and calculate the decontamination factor and corrosion depth.

[0081] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0082] Comparative Example 2:

[0083] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 3:

[0084]

[0085] Table 3

[0086] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump with a flow rate of 2.5m / s and a decontamination time of 20mins. After the decontamination is completed, the decontamination waste liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter, and its mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0087] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0088] Comparative Example 3:

[0089] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 4:

[0090]

[0091] Table 4

[0092] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0093] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0094] Comparative Example 4:

[0095] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 5:

[0096]

[0097] Table 5

[0098] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0099] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0100] Comparative Example 5:

[0101] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 6:

[0102]

[0103] Table 6

[0104] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0105] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0106] Comparative Example 6:

[0107] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 7:

[0108]

[0109] Table 7

[0110] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0111] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0112] Comparative Example 7:

[0113] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 8:

[0114]

[0115] Table 8

[0116] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0117] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0118] Comparative Example 8:

[0119] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 9:

[0120]

[0121] Table 9

[0122] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0123] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0124] Comparative Example 9:

[0125] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 10:

[0126]

[0127] Table 10

[0128] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0129] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0130] Comparative Example 10:

[0131] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 11:

[0132]

[0133] Table 11

[0134] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0135] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0136] Comparative Example 11:

[0137] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 12:

[0138]

[0139] Table 12

[0140] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0141] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0142] Comparative Example 12:

[0143] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 13:

[0144]

[0145] Table 13

[0146] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0147] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0148] Comparative Example 13:

[0149] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 14:

[0150]

[0151] Table 14

[0152] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0153] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0154] Comparative Example 14:

[0155] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 15:

[0156]

[0157] Table 15

[0158] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0159] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0160] Comparative Example 15:

[0161] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 16:

[0162]

[0163]

[0164] Table 16

[0165] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0166] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0167] Comparative Example 16:

[0168] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 17:

[0169]

[0170] Table 17

[0171] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 40mins. After the decontamination is completed, the decontamination liquid is emptied and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0172] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0173] Comparative Example 17:

[0174] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 18:

[0175]

[0176]

[0177] Table 18

[0178] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 10mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0179] Step 3: Degradation of decontamination waste liquid: Add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0180] Comparative Example 18:

[0181] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 19:

[0182]

[0183] Table 19

[0184] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0185] Step 3: Degradation of decontamination waste liquid: add hydrogen peroxide at a mass ratio of 2.0% to the decontamination waste liquid, heat the decontamination waste liquid to 65° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0186] Comparative Example 19:

[0187] Step 1: Prepare the cleaning solution: The selected formula ratio of the cleaning solution is as shown in Table 20:

[0188]

[0189]

[0190] Table 20

[0191] Step 2: Chemical decontamination: The decontamination liquid is injected into the radioactive waste liquid evaporator without heating. The decontamination liquid is circulated by a centrifugal pump at a flow rate of 2.5m / s and the decontamination time is 20mins. After the decontamination is completed, the decontamination liquid is drained and then rinsed with deionized water to complete the decontamination. The surface dose of the radioactive waste liquid evaporator is measured using a portable surface contamination meter. The mass loss is obtained using an electronic balance to calculate the decontamination factor and corrosion depth.

[0192] Step 3: Degradation of decontamination waste liquid: add hydrogen peroxide at a mass ratio of 1.0% to the decontamination waste liquid, heat the decontamination waste liquid to 40° C., react for 25 minutes, and then discharge the waste liquid into the three-waste system.

[0193] Based on the above tests, decontamination factor and corrosion depth test analysis were carried out, and the results are detailed in Table 21.

[0194]

[0195]

[0196] The degradable chemical decontamination formula and use method for radioactive waste liquid evaporator provided in the present application have good decontamination effect, low formula toxicity, low corrosion to waste liquid evaporator, safety and environmental protection, and simple use method. It can safely and efficiently complete the chemical decontamination of radioactive waste liquid evaporator, and the organic decontamination waste liquid after decontamination is inorganically treated, and the degradation rate of organic matter in the decontamination waste liquid within 0.5h exceeds 98%.

[0197] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present application.

[0198] The above application serial numbers are for description only and do not represent the advantages or disadvantages of the implementation scenarios.

[0199] The above disclosure only discloses several specific implementation scenarios of the present application. However, the present application is not limited thereto, and any changes that can be conceived by technicians in this field should fall within the scope of protection of the present application.

Claims

1. A degradable chemical decontamination formula and method of use for a radioactive waste liquid evaporator, characterized in that: include: Prepare decontamination fluid for decontamination of radioactive waste evaporators; injecting the decontamination liquid into the radioactive waste liquid evaporator, and using the decontamination liquid to decontaminate the interior of the radioactive waste liquid evaporator; acquiring a decontamination time of the radioactive waste liquid evaporator, and when the decontamination time reaches a preset decontamination time threshold, discharging the decontamination waste liquid in the radioactive waste liquid evaporator, and flushing the inside of the radioactive waste liquid evaporator with deionized water; The decontamination waste liquid is degraded by using an oxidant.

2. The method according to claim 1, characterized in that The step of injecting the decontamination liquid into the radioactive waste liquid evaporator and using the decontamination liquid to decontaminate the inside of the radioactive waste liquid evaporator specifically includes: injecting the decontamination liquid into the radioactive waste liquid evaporator; The centrifugal pump in the radioactive waste liquid evaporator is started, and the centrifugal pump is controlled to run at a preset speed so that the decontamination liquid circulates inside the radioactive waste liquid evaporator to decontaminate the inside of the radioactive waste liquid evaporator.

3. The method according to claim 1, characterized in that The step of using an oxidant to degrade the decontamination waste liquid specifically comprises: injecting an oxidant into the discharged decontamination waste liquid; The decontamination waste liquid is heated according to a preset temperature and a preset time, and the organic matter in the decontamination waste liquid is degraded by the oxidant; The degraded decontamination waste liquid is discharged into the wastewater treatment system.

4. The method according to any one of claims 1 to 3, characterized in that The raw materials of the decontamination liquid include, by weight: 19 to 37 parts of inorganic acid, 3 to 6 parts of complexing agent, 0.5 to 1.5 parts of sustained-release agent, 0 to 1.0 parts of surfactant, and the balance is deionized water.

5. The method according to claim 4, characterized in that The inorganic acid includes at least one of the following: hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid; The complexing agent comprises at least one of the following: sodium ethylenediaminetetramethylenephosphate, diethylenetriaminepenta(methylenephosphonate), disodium ethylenediaminetetraacetate, tetrasodium iminodisuccinate and fatty alcohol polyoxyethylene ether; The sustained-release agent comprises at least one of the following: citric acid, polyaspartic acid, triethanolamine, ferrous sulfate, ferrous nitrate, and ammonium thioacetate; The surfactant includes at least one of cetyltrimethylammonium bromide, cetylpentyldimethylammonium bromide, polyacrylamide, sodium dodecylbenzene sulfonate and sodium dodecylbenzene sulfonate.

6. The method according to claim 4, characterized in that The step of preparing a decontamination liquid for decontaminating a radioactive waste liquid evaporator specifically comprises: Pour deionized water into the container; The complexing agent, the inorganic acid, the sustained-release agent and the surfactant are sequentially added into the container and stirred to obtain the decontamination liquid.

7. The method according to any one of claims 1 to 3, characterized in that The preset decontamination time threshold is 20 minutes to 40 minutes.

8. The method according to any one of claims 1 to 3, characterized in that The preset speed of the centrifugal pump is 2m / s to 5m / s.

9. The method according to any one of claims 1 to 3, characterized in that The oxidant is hydrogen peroxide; The added amount of the oxidant is 0.5% to 1.5% of the decontamination waste liquid.

10. The method according to any one of claims 1 to 3, characterized in that The preset temperature for the degradation operation is 50 degrees Celsius to 70 degrees Celsius; The preset time for the degradation operation is 10 minutes to 40 minutes.

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