Ion exchange resin treatment system and ion exchange resin treatment method

Abstract

The present invention relates to an ion exchange resin treatment system (10) for treating radioactively contaminated ion exchange resin waste, in which a supercritical water oxidation reactor (12) is connected at its inlet side to an air supply device, a waste supply device, a fuel supply device and a water supply device (28), an ion exchange resin crushing system (24) is connected upstream of the waste supply device for crushing the ion exchange resin to be treated until the ion exchange resin to be crushed falls below a predetermined ion exchange resin particle size, and the crushed ion exchange resin is supplied to the waste supply device, the supercritical water oxidation reactor (12) is connected at its outlet side to a separation device (38), a mixture of gas and liquid obtained from the supercritical water oxidation reactor (12) is separated into respective phases by the separation device (38), the separated gas is supplied to a gas outlet element and the separated liquid is supplied to a liquid outlet element, and at least the supercritical water oxidation reactor (12), the air supply device, the waste supply device, the fuel supply device and the water supply device are controlled by a control device. The present invention also relates to a method for treating radioactively contaminated ion exchange resin waste.

Description

[Technical field]

[0001] The present invention relates to an ion exchange resin treatment system for treating radioactively contaminated ion exchange resin waste, in which a supercritical water oxidation reactor is connected at its inlet side to an air supply device, a waste supply device, a fuel supply device and a water supply device, and an ion exchange resin crushing system is connected upstream of the waste supply device, which crushes the ion exchange resin to be treated until the ion exchange resin to be crushed falls below a predetermined ion exchange resin particle size, the crushed ion exchange resin is supplied to the waste supply device, and the supercritical water oxidation reactor is connected at its outlet side to a separation device, the separation device separates a mixture of gas and liquid obtained from the supercritical water oxidation reactor into respective phases, the separated gas is supplied to a gas outlet element and the separated liquid is supplied to a liquid outlet element, and a control device controls at least the supercritical water oxidation reactor, the air supply device, the waste supply device, the fuel supply device and the water supply device, and a method therefor. [Background technology]

[0002] The use of ion exchange resins to purify water or wastewater in nuclear plants and nuclear power plants is commonly known. Particularly in the nuclear field, radioactively contaminated ion exchange resins may have to undergo complex treatment before disposal, often involving dehydration and / or drying followed by hardening in a polymer or asphalt matrix or a cement solidification process.

[0003] Before the disposal process, the spherical ion exchange resins can be directly treated or can be pretreated, for example crushed, i.e. ground, using a suitable grinder. In this case, the ion exchange resins are suspended in water and passed through a grinder to achieve the desired grinding. The grinding of the ion exchange resins is carried out in order to obtain better results in the subsequent disposal process, for example to reduce the tendency to float when the ground resin is incorporated in the disposal matrix, to improve the heat transfer due to an increased surface area during drying, and thus to reduce the drying time, or to improve the compression properties during high-pressure pressing. In order to improve the disposal process, for example from US Pat. No. 5,399,433, an ion exchange resin grinding device is known which provides particularly good grinding results in order to reduce the subsequent drying time or, as mentioned above, to improve the compression properties during high-pressure pressing.

[0004] The disadvantage of this prior art is that, although the disposal process of radioactive ion exchange resins itself is improved, the volume of ion exchange resins and radioactive material bound to the ion exchange resins that must be temporarily or finally stored in corresponding storage devices remains almost unchanged by pretreatment before the disposal process and relatively high. Even if the ion exchange resins are further pretreated, the volume of radioactive solid waste consisting of ion exchange resins and radioactive solids remains unchanged and high.

[0005] Furthermore, a method for treating radioactive waste and a system for carrying out said method are also known from patent document 2, in which contaminated ion exchange resin stored in a container at a nuclear power plant is removed from the container and fed to an oxidation reactor. It has become clear that ion exchange resins such as those removed from nuclear power plants do not give optimal results in treating the organic components of the ion exchange resin, and that residues of the ion exchange resin remain after the oxidation process or that the oxidation process cannot be carried out stably for long periods of time. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE 102012012828 A1 [Patent Document 2] DE 10140525 A1 Summary of the Invention [Problem to be solved by the invention]

[0007] Based on this prior art, the object of the present invention is to provide an improved ion exchange resin treatment system having a supercritical water oxidation system for treating a quantity of radioactive ion exchange resin, and also to disclose a method for reducing the volume of radioactive solids for intermediate or final storage. [Means for solving the problem]

[0008] The object is to provide an ion exchange resin treatment system for treating radioactively contaminated ion exchange resin waste, in which a supercritical water oxidation reactor is connected at its inlet side to an air supply device, a waste supply device, a fuel supply device and a water supply device, an ion exchange resin crushing system is connected upstream of the waste supply device for crushing the ion exchange resin to be treated until the particle size falls below a predetermined particle size of the ion exchange resin to be crushed, the crushed ion exchange resin is supplied to the waste supply device, the supercritical water oxidation reactor is connected at its outlet side to a separation device, a mixture of gas and liquid obtained from the supercritical water oxidation reactor is separated into respective phases by the separation device, the separated gas is supplied to a gas outlet element and the separated liquid is supplied to a liquid outlet element, and the supercritical water oxidation reactor, the air supply device, the waste supply device, the fuel supply device and the water supply device are controlled by a control device. The ion exchange resin treatment system is characterized in that the ion exchange resin grinding system has a container, from which a suspension of liquid and ion exchange resin is extracted using a circulation pump and supplied to an ion exchange resin grinding device, the suspension of crushed ion exchange resin and liquid is returned to the container through a conduit, the suspension is extracted from the container by an extraction pump and supplied to a classification device, the classification device separates ion exchange resin exceeding a predetermined ion exchange resin particle size from the suspension and at least the separated ion exchange resin particles are returned to the container, ion exchange resin in the remaining liquid component having a predetermined ion exchange resin particle size or less is supplied to an outlet element of the classification device as a classified suspension, the classified suspension supplied by the classification device is supplied to a concentration measuring device, the concentration measuring device determines a concentration value of ion exchange resin particles in the suspension, the classified suspension is supplied for removal by a second pump device only when the determined concentration value reaches or exceeds a specified concentration value compared to the specified concentration value, and when the determined concentration value falls below the specified concentration value, the classified suspension is returned to the container.

[0009] The basic idea of ​​the present invention is no longer to store radioactive ion exchange resin waste after immobilization by cementation or binding to other matrices as in the conventional case, but to first chemically / physically decompose the organic components, i.e. in particular the ion exchange resins, in a supercritical water oxidation reactor (oxidation reactor for short) for the supercritical water oxidation process. The supercritical water oxidation process is adjusted so that at the end of the process, i.e. at the outlet of the oxidation reactor, only carbon dioxide and air components are present as gases, and water and salts or ions dissolved in water as liquids. The supercritical water oxidation process is known to the person skilled in the art for other, especially dangerous, industrial wastes and has been modified as follows for the treatment of ion exchange resin wastes:

[0010] First, the ion exchange resin waste, fuel, water and air are fed into the inlet side oxidation reactor by corresponding feeding devices. At this time, the amount or mass flow rate of each substance introduced into the oxidation reactor is individually controlled by the control device in terms of amount, temperature and pressure so that the above-mentioned final substances are produced as starting materials. If necessary, caustic soda can be added to the water of the oxidation reactor to increase the pH value.

[0011] It has been found to be advantageous for the entire process if the ion exchange resin of the ion exchange resin waste is crushed before being fed to the oxidation reactor. The smaller the ion exchange resin is crushed, the shorter the processing time in the oxidation reactor until the ion exchange resin is completely decomposed, and the higher the efficiency of the oxidation reactor in decomposing the ion exchange resin. The entire process proceeds steadily and is improved overall. The typical particle size of the ion exchange resin is an ion exchange resin particle size of 0.6 mm to 1 mm, and ideally, the crushing process reduces the ion exchange resin particle size to less than 100 μm, preferably less than 50 μm. The crushing process advantageously allows a stable operation of the ion exchange resin processing system. It also avoids the possibility of clogging the ion exchange resin supply pipe to the oxidation reactor with excessively large ion exchange resin particles or their connections. Furthermore, the process time for the processing of the ion exchange resin in the oxidation reactor is shortened. This also ensures that the ion exchange resin is completely decomposed in the oxidation reactor.

[0012] After passing through the supercritical water oxidation in the oxidation reactor, the gaseous and liquid components are separated by a separator and are available at different outlets of the separator. It is further advantageous that all radioactive substances are present only as dissolved salts or ions in non-radioactive water. As a result, the original solids volume of the ion exchange resin waste is advantageously reduced in any case by the solids volume of the ion exchange resin. In the disposal process following the above-mentioned treatment of the ion exchange resin waste, the volume of the liquid can be further reduced by removing the water. In this way, the salts or ions contained in the liquid are concentrated.

[0013] Intermediate or final storage of the reduced radioactive waste in liquid form can be carried out, for example, by conventional cementation or other methods known to those skilled in the art.

[0014] To further improve the ion exchange resin treatment system, the ion exchange resin treatment system has further features, namely, the ion exchange resin grinding system has a container from which a suspension of liquid and ion exchange resin is taken by a circulation pump and fed to an ion exchange resin grinding device, and the suspension of ground ion exchange resin and liquid is returned to the container through a conduit. As proposed here, by continuously taking a part of the suspension from the container by a circulation pump and then grinding the ion exchange resin contained in the suspension, an ion exchange resin grinding system is obtained that is realized with relatively small components and nevertheless provides a predetermined grinding of the ion exchange resin. During the operation of the ion exchange resin grinding system, the circulation with grinding is always continued, and substantially all the particles of the ion exchange resin are ground to a certain ion exchange resin particle size determined to be optimal for the subsequent supercritical water oxidation process.

[0015] The ion exchange resin grinding system is further improved if the suspension is extracted from the vessel by an extraction pump and fed to a classifier, which separates ion exchange resin particles above a predetermined ion exchange resin particle size from the suspension and returns at least the separated ion exchange resin particles to the vessel. The extraction pump is started together with the ion exchange resin grinding system or only after a certain time has elapsed, for example 5 minutes after the ion exchange resin grinding device is started, in order to give the device a certain operating lead time.

[0016] The classifier then determines which ion exchange resin particles are larger than a predetermined ion exchange resin particle size. The excessively large ion exchange resin particles are returned to the vessel. Another part of the ion exchange resin particles, i.e. the remaining components in the suspension, whose ion exchange resin particle size is the same size as or smaller than the predefined ion exchange resin particle size, is fed to the oxidation reactor. The classifier can be, for example, a decanter centrifuge, which removes the excessively large ion exchange resin particles from the suspension, and the ion exchange resin particles are returned to the vessel without the liquid component. However, the classifier can also be, for example, configured as a liquid centrifuge, and the excessively large ion exchange resin particles are returned to the vessel together with the liquid component.

[0017] An additional improvement of the ion exchange resin grinding system is that the classified suspension provided by the classifying device is fed to a concentration measuring device, the concentration value of the ion exchange resin particles in the suspension is determined by the concentration measuring device, and only if the determined concentration value is reached or exceeded in comparison with a specified concentration value, the classified suspension is fed for removal by the second pumping device, and if it falls below the specified concentration value, the classified suspension is returned to the container. In other words, the concentration measuring device ensures according to the invention that only the optimal classified suspension prepared for the process is fed to the supercritical water oxidation process. The specified concentration value is correspondingly determined. For example, it has been found that an optimal result in the supercritical water oxidation process is obtained if the volume percentage of ground ion exchange resin in the classified suspension is 30%.

[0018] In order to obtain particularly reliable results for the composition values, the concentration measuring device is preferably configured as a density measuring device or a turbidity measuring device.

[0019] A further preferred embodiment of the ion exchange resin treatment system is characterized in that the vessel has a first stirring device with stirring elements that homogenize the distribution of the ion exchange resin particles in the liquid in the vessel. The first stirring device avoids settling of the ion exchange resin particles in the liquid and achieves as homogeneous a distribution of the ion exchange resin particles in the liquid as possible. With a homogeneous suspension of ion exchange resin particles and liquid, for example, the comminution of the ion exchange resin in an ion exchange resin comminution system is improved in that the homogeneous suspension increases the efficiency.

[0020] A further improvement of the ion exchange resin treatment system is that the vessel has a second stirring device with a grinding stirring element for grinding the ion exchange resin particles in the liquid in the vessel. That is, the second stirring device acts as a pre-grinding device for breaking up or grinding up possible agglomerations or solidification of the ion exchange resin particles, so that generally only individual ion exchange resin particles are present in the suspension. This is particularly advantageous when the ion exchange resin grinding device has an optimal efficiency for ion exchange resin particle size up to a certain size.

[0021] It is also advantageous if the ion exchange resin treatment system is characterized in that the ion exchange resin crushing device is also controlled by the control device. Typically, the ion exchange resin crushing device has a separate control device, which receives or exchanges necessary or desired information from the control device via a corresponding interface, as the case may be, and controls all open-loop and closed-loop control processes required for the crushing of the ion exchange resin. However, the open-loop and closed-loop control processes can also be taken over by the control device. In this case, a control device is advantageously not required.

[0022] In an alternative embodiment of the ion exchange resin treatment system, the separated gas is fed from the gas outlet element to a first condenser, and the separated liquid is fed from the liquid outlet element to an evaporator depending on the content of the separated liquid, from which water vapor is fed to a second condenser or to a drum dryer. In a variant of this embodiment, the amount of waste radioactive material is further reduced. Furthermore, the water produced in the condenser contains only small amounts of other substances or ions, so that further wastewater treatment is no longer necessary. For example, the condensate is collected in a condensate container and then returned to the water supply and can be used again in the supercritical water oxidation process, or, for safety reasons, can be introduced into the wastewater treatment system of the nuclear power plant in which the ion exchange resin treatment system is installed or discharged into an existing water network. In this way, the amount of waste is advantageously further reduced by the removal of water, and furthermore, the water originally contained in the liquid is supplied for further use.

[0023] The object of the present invention is also achieved by a method for treating radioactively contaminated ion exchange resin, the method comprising the steps of: - grinding the radioactively contaminated ion exchange resin until a predetermined ion exchange resin particle size is reached in the suspension of liquid and ion exchange resin in the container, providing a classified suspension; - taking off a further partial stream of the classified suspension and monitoring the concentration values ​​of the ion exchange resin particles in this further partial stream, - supplying the classified suspension for removal by the second pump device only if the determined concentration value is reached or exceeded in comparison with a prescribed concentration value, - feeding air and a suspension of fuel, water and pulverized ion exchange resin into a supercritical water oxidation reactor as a classified suspension having at least a certain concentration value; - controlling the amounts of air, fuel, water and pulverized ion exchange resin fed to the supercritical water oxidation reactor so that the supercritical water oxidation reactor decomposes all organic components in the suspension into a mixture of gas comprising carbon dioxide and water vapor, and liquid comprising water and dissolved or liberated non-organic ions; - Separating the gas from the mixture.

[0024] In other words, the method according to the invention provides that the radioactively contaminated ion exchange resin is first comminuted until the ion exchange resin particles are small enough that the subsequent supercritical water oxidation process proceeds relatively quickly and with particularly high efficiency, and the organic components in the suspension, in particular the ion exchange resin, are completely decomposed into inorganic components. After passing through the supercritical water oxidation, a mixture of gas and liquid remains, which consists only of inorganic substances. Any gases present, in particular carbon dioxide, possibly nitrogen oxides or air components, are separated from said mixture, which are not radioactive. The radioactivity remains in the liquid, which no longer contains solids and is therefore reduced at least by the volume of the ion exchange resin particles, and the overall volume of the solid waste, for example the volume supplied for intermediate or final storage in the waste process, is correspondingly reduced, even after the water is removed from the liquid. The method according to the invention is advantageously carried out using the ion exchange resin treatment system described in detail above.

[0025] Furthermore, it is advantageous for the method if the separated gas is discharged to the environment after being dried in the first condenser. The separated gas does not contain radioactive materials and can be discharged to the environment without problems. Advantageously, no further waste disposal occurs.

[0026] In a further process variant, the liquid is fed according to its content to an evaporator, which evaporates the water present in the liquid and feeds the wet residue to a drum dryer, after which the water vapor is condensed to water in a second condenser or the liquid is fed directly to a drum dryer, in which the water present is removed from the liquid until a residue remains. In this way, the amount of waste is reduced by the amount of water. The extracted water itself is not or only slightly radioactive and can therefore be fed to a water treatment system or, if this slight radioactivity is below the corresponding limit value, can be released into the environment.

[0027] The radioactivity remains completely or at least almost completely in the residue, which after removal of water or moisture has an advantageously small overall volume and can finally be transported to a final storage facility or prepared for intermediate or final storage throughout the disposal process. The decision whether to feed the liquid first to the evaporator or immediately to the drum dryer is made empirically, i.e. based on the ion exchange resin waste fed to the supercritical oxidation process, or a measuring and analyzing device installed for this purpose analyzes the substances contained in the liquid and the feeding of the liquid to the evaporator or to the drum dryer is decided by the control device on the basis of the analysis.

[0028] It is further advantageous if the method is characterized in that the water is sent from the first or / and second condenser to a condensate container and the water collected in the condensate container is selectively sent to a wastewater treatment system or to a water supply device. The water collected in the condensate container is free or only slightly radioactive and can therefore be particularly easily reused or, if necessary, released into the environment after further treatment.

[0029] An advantageous variant of the method is characterized in that the suspension of water and ion exchange resin particles in the vessel is homogenized before and during the grinding of the ion exchange resin, which advantageously increases the efficiency, for example, of the grinding of the ion exchange resin using the ion exchange resin grinding system according to the invention.

[0030] Further advantages of the present invention are obtained if the ion exchange resin in the suspension in the vessel is pre-comminuted by a second stirring device. By pre-comminuted, the solid components of the suspension, in particular those larger than the average particle size of the ion exchange resin (typically about 1 mm), are already comminuted. This is advantageous because ion exchange resin comminution systems generally have optimal efficiency when the particles to be comminuted have a certain maximum dimension. Therefore, overall, the effectiveness of the ion exchange resin comminution and therefore the effectiveness of the ion exchange resin treatment system are advantageously increased.

[0031] In an advantageous alternative of the method, the suspension in the vessel is transported by means of a circulation pump to an ion exchange resin grinding device, the ion exchange resin in the suspension is ground in the ion exchange resin grinding device, the ion exchange resin passes through the ion exchange resin grinding device and is returned to the vessel as ground ion exchange resin in suspension. Basically, a cycle is created in which the suspension is removed from the vessel, the ion exchange resin is ground in the ion exchange resin grinding device and the suspension is returned to the vessel again. It is thus possible to repeatedly pass the suspension through the ion exchange resin grinding device until the desired grinding of a certain percentage of the ion exchange resin is achieved. The ion exchange resin grinding device can be designed to be correspondingly small compared to grinders which are intended to pass the ion exchange resin only once and produce a certain percentage of ground ion exchange resin.

[0032] A further advantage arises if the ion exchange resin in the suspension is crushed by an ion exchange resin crushing device for a defined time before the extraction pump is activated, which feeds a partial flow of the suspension from the container to the classifier, and the classifier separates the ion exchange resin particles that exceed a defined ion exchange resin particle size from the suspension, sends the separated ion exchange resin particles back to the container together with the partial flow of the suspension, and feeds the remaining suspension to the outlet element of the classifier. By activating the extraction pump only after a defined time, a relatively large part of the ion exchange resin in the suspension is already reduced to the required ion exchange resin particle size by the ion exchange resin crushing device before the suspension is fed to the classifier. The classifier is a kind of control device that recognizes excessively large ion exchange resin particles, separates them and returns them to the container. Thus, only ion exchange resin particles in the suspension that are below the required size are fed as classified suspension for further processing in the method.

[0033] In a further advantageous variant of the method, the classified suspension provided by the classification device is fed to a concentration measuring device, which determines a concentration value of ion exchange resin particles in the classified suspension, and the classified suspension is fed for removal by the second pump device only if the determined concentration value is reached or exceeded compared to a specified concentration value, and if the specified concentration value is exceeded, the classified suspension is pumped back to the container. In this way, it is obtained that not only the particle size of the ion exchange resin particles has a size favorable for supercritical water oxidation, but also that the concentration of the ion exchange resin particles in the classified suspension has a concentration value optimal for supercritical water oxidation. This is the case, for example, when the volume concentration of ion exchange resin particles in the classified suspension is 30%.

[0034] Further advantageous embodiment possibilities result from the further dependent claims.

[0035] The invention, further embodiments and further advantages will be explained in more detail on the basis of examples shown in the drawings, in which: [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 illustrates an exemplary ion exchange resin treatment system. [Diagram 2] FIG. 1 illustrates an exemplary ion exchange resin comminution system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] FIG. 1 is a process diagram showing an embodiment of an ion exchange resin treatment system 10, in which an oxidation reactor 12 serves as a supercritical water oxidation reactor for subjecting various input materials to a water oxidation process using supercritical water for the destruction of organic waste, the so-called SCWO process (= supercritical water oxidation process). The SCWO process and various reactors for carrying it out are also known, for example, as the so-called iSCWO process and reactors. The reactors used there are capable of destroying the organic components of pesticides, dioxins, paints or explosives. To use supercritical water in the oxidation process, the water in the oxidation reactor is first brought to a temperature of 374° C. or higher at a pressure of at least 221 bar. Under these supercritical conditions, the water acquires the special properties required for the oxidation process. The preferred process temperature is between 400° C. and 650° C., and the preferred process pressure is between 225 bar and 250 bar.

[0038] In the following, the present example will explain in more detail how the supercritical water oxidation for the treatment of radioactively contaminated ion exchange resin waste is configured in the present invention. For this purpose, the air supply system has a compressor 14 which takes air from the environment and compresses it to at least about 225 bar. The compressed air is then fed to an air preheater 16, which heats the air stream to at least 650° C. The air thus heated is finally fed to the inlet oxidation reactor 12 through a piping system.

[0039] A first pumping device 20 takes diesel fuel from the first storage vessel 18 and pumps it through a conduit in the direction of the oxidation reactor 12. As an alternative to diesel fuel, other fuels are also contemplated, such as, for example, propane gas.

[0040] From the second storage vessel 22, the ion exchange resin waste (which is in the form of ion exchange resin particles, which typically have a particle size of about 1 mm) is fed to an ion exchange resin grinding system 24. The ion exchange resin grinding system 24 grinds the ion exchange resin waste so that the majority of the ion exchange resin particles are below a predetermined particle size of 100 μm, preferably 50 μm. A second pumping device 26 removes the ground ion exchange resin waste from the ion exchange resin grinding system 24 in the form of a water suspension and feeds the suspension into a diesel fuel conduit, where the diesel fuel is mixed with the suspension.

[0041] A certain water flow is also fed from a water supply 28, which can be for example a water network or a water tank, into the diesel fuel conduit where it is mixed with the diesel fuel and the suspension. Another water part stream is fed by a third pumping device 30, which increases the pressure of the water part stream and feeds it to the oxidation reactor 12. This water part stream is used for cooling purposes of the process in the oxidation reactor 12. From a third storage vessel 32, caustic soda is added to the water stream by means of a fourth pumping device 34, if necessary, in an amount sufficient to neutralize the sulfuric acid resulting from the decomposition of the ion exchange resin.

[0042] Finally, a fifth pumping device 36 feeds a mixture of diesel fuel, suspension and water to the air stream, and the resulting mixture of substances is introduced into the inlet side of the oxidation reactor 12. The oxidation reactor 12 itself decomposes the organic components of the mixture, in particular the ion exchange resin and possibly organic pollutants, into non-organic components by means of a supercritical water oxidation process. As a result, at the outlet side, gases, in particular water vapor, carbon dioxide (CO2) and possibly traces of sulfur oxides (SOx), nitrogen oxides (NOx), water and salts dissolved in water, i.e. a mixture of metal and non-metal ions, are fed for further processing. That is, at the end of the supercritical water oxidation process, all organic components have been decomposed into non-organic components, which can be further processed using other waste treatment methods and waste treatment systems for non-organic waste. Gases, in particular sulfur oxides (SOx) or nitrogen oxides (NOx), which are generated in relatively large amounts in other methods, for example in the incineration process of organic substances, are also not generated or are generated only in small amounts (trace amounts) and remain mostly in the liquid phase in ionic form.

[0043] A control device, not shown, controls all processes involved in the supercritical water oxidation, in particular the supply of air, diesel fuel, ion exchange resin waste, water and possibly caustic soda in an open or closed loop manner in relation to all relevant physical parameters, such as mass or volumetric flow rates, pressure or temperature, so that the supercritical water oxidation process runs optimally. Such process control is known to the skilled person and is carried out on the basis of the given conditions in the concrete application case. Advantageously, a significant reduction in the volume of the ion exchange resin waste is obtained due to the destruction of the organic molecular structure of the ion exchange resin. That is, the largest part of the ion exchange resin waste is the ion exchange resin, and the ions attached to the ion exchange resin, in particular the radioactively contaminated ions, only constitute a relatively small part of the waste amount. Nevertheless, radioactive materials are still present in the mixture, the disposal of which is subject to special legal rules and regulations, which are generally known. That is, the mixture can be fed, for example, to a cement solidification process or to a process for further reducing the volume of the mixture, for example, as described in more detail below.

[0044] At the outlet side of the oxidation reactor 12, the mixture is still under pressure above ambient pressure. The mixture is then fed to a separator 38, which separates the gaseous components from the liquid components of the mixture and feeds them to a gas or liquid outlet element, respectively.

[0045] The separated gases, mainly carbon dioxide and water vapor, are sent from the gas outlet element through a piping system to the first condenser 40, which removes water vapor from the gas stream to dry it. The dry gaseous carbon dioxide has no radioactive components and is released to the environment through the ventilation element 44. The condensed water is sent to the condensate container 42 and collected therein.

[0046] The liquid outlet element is located at a geodetic lower position of the separator 38. From there, a part of the liquid components of the mixture is sent by means of a sixth pump device 46 to an evaporator 48, where the water of the mixture is evaporated. In this case, the water vapor is sent to a second condenser 50, which condenses the water vapor again to liquid water, which is also discharged to and collected in the condensate container 42. The residual stream after passing through the evaporator 48 is fed to a drum dryer 52. In the drum dryer 52, which comprises, for example, a 200 liter drum or other container suitable for storage or final storage, and which uses a negative pressure generated by a water ring compressor for the removal of water, the remaining water is removed together with the residual stream. In this case, the drum has an electric heater at its bottom and in the almond-shaped cavity. As an alternative to the electric heater, the heat supply to the drum can also be carried out through a heated chamber in which the drum is housed and which is supplied with appropriately preheated air.

[0047] Another portion of the liquid components of the mixture is sent directly to drum dryer 52, where water is also removed from the liquid components. Only residues remain at drum dryer 52, i.e., salts and other solid components that are radioactive in themselves. These residues have an even smaller volume than the starting material, i.e., the mixture, which was already reduced in volume compared to the ion exchange resin waste. Thus, overall, the volume of the radioactive waste is advantageously reduced by ion exchange resin treatment system 10.

[0048] The water collected in the condensate container 42 can be selectively discharged to the environment using a corresponding discharge device 54 (possibly after further treatment) or supplied to the water supply device 28 using a transport pipe.

[0049] FIG. 2 shows a schematic representation of an advantageous embodiment of the ion exchange resin grinding system 24 with a vessel 56, into which a waste suspension consisting of ion exchange resin waste and water is introduced by a feeder 58 in a predetermined amount. The vessel 56 has a resin concentration monitor and a level measuring device for the level of the waste suspension, which are not shown for reasons of simplicity. After filling the vessel 56 with a predetermined amount of waste suspension and checking the liquid level in the vessel 56, a first agitator 60 is started, which drives an agitator located in the area in the vessel 56 that is covered by the suspension while the ion exchange resin grinding system 24 is operating. In this case, the vessel 56 is not pressurized, i.e. it is only under ambient pressure and has ambient temperature. The agitator has the task of moving the waste suspension in such a way that homogenization of the solids in the suspension takes place. Furthermore, the vessel 56 also has a second agitator 62, which is arranged in the lower third of the vessel 56 as viewed in the geodesic direction. The second mixer 62 is configured as a pre-crushing or pre-grinding device and starts up together with the first mixer 60. On the one hand, the second mixer 62 assists the homogenization process, and on the other hand, the ion exchange resin particles are already partially crushed or the ion exchange resin particles that are stuck to one another are separated from one another again.

[0050] When sufficient homogenization of the waste suspension has been obtained in the manner described above, a continuous flow of waste suspension is taken from the vessel 56 by means of a circulation pump 64 and fed to an ion-exchange resin grinding device 66. This may be configured similarly to the ion-exchange resin grinding device known, for example, from DE 10 20 03 133 A1, i.e. in particular may consist of two stages: a pre-grinding device, configured, for example, as a dispersing device, and a colloid mill, the rotor or stator crown of which may be conical. After passing through the ion-exchange resin grinding device 66, the waste suspension is returned to the vessel 56 through a conduit.

[0051] After a predetermined time has elapsed since the first agitator 60 and the second agitator 62 have been started, the extraction pump 68 is also started. At this time, the predetermined time is empirically determined and calculated so that it is expected that the ion exchange resin crushing device 66 has already crushed or pulverized at least 70% of the ion exchange resin particles in the ion exchange resin crushing system 24 to the desired particle size (in the selected example, a particle size smaller than 100 μm). At this time, the extraction pump 68 transports the suspension of crushed ion exchange resin particles, water, and salts or ions dissolved in the water to the classifier 70, which is configured to retain excessively large ion exchange resin particles, i.e., particles larger than 100 μm, and return them to the container 56 through a corresponding conduit. In the container 56, the first agitator 60 and the second agitator 62 are operating. Furthermore, the ion exchange resin crushing device 66 crushes the ion exchange resin particles contained in the suspension. The interaction of the ion exchange resin grinding system 24 and the classifier 70 advantageously allows for continuous operation of the ion exchange resin treatment system 10. For example, as soon as a large amount of suspension is removed from the ion exchange resin treatment system 10 and a certain liquid level in the container 56 is lowered, further ion exchange resin waste can be easily added to the container 56 by the feeder 58, and the continuous process of grinding the ion exchange resin particles and continuously extracting them by the extraction pump 68 continues. In this way, repeated start-ups and stop-ups of the ion exchange resin treatment system 10 that would otherwise be necessary are advantageously avoided, along with the additional energy consumption associated therewith. Furthermore, alternating stresses on the materials of the ion exchange resin treatment system 10 due to switching from ambient conditions to high operating pressures and temperatures during start-up and shutdown are also avoided.

[0052] The classifier 70 can in this case be particularly advantageously configured as a centrifuge, for example as a decanter centrifuge, which separates excessively large ion exchange resin particles, or for example as a liquid centrifuge, which also removes excessively large ion exchange resin particles from the suspension. After passing through the classifier 70, the classified suspension, which in particular comprises ion exchange resin particles below the desired particle size, is then fed to a concentration measuring device 72, which can preferably be configured as a density measuring device or, for example, as a turbidity measuring device. The concentration measuring device 72 can in this case be regarded as a kind of final check of the classified suspension, the task of which is to determine how high the proportion of ion exchange resin particles in the suspension is.

[0053] If the percentage of ion exchange resin particles in the suspension measured by the concentration measuring device 72 is at least equal to a predetermined percentage value, for example 30%, the supercritical water oxidation process is initiated and the suspension is fed to the process. If the measured percentage exceeds the predetermined percentage value, water is added to the suspension as necessary to obtain the predetermined value. Typically, the predetermined percentage value is not a single value, but rather a range of percentage values, for example between 30% and 35%.

[0054] If necessary for the operation of the ion exchange resin grinding system, the suspension present in the concentration measuring device 72 can be returned to the container 56 through a corresponding conduit. The suspension is again transported through the grinding circuit, i.e. by means of the circulation pump 64, to the ion exchange resin grinding device 66, which further grinds the ion exchange resin particles, for example, until the proportion in the concentration measuring device 72 reaches at least a predetermined proportion value. As already mentioned, as soon as the predetermined proportion value is reached, the process of supercritical wax hydroxide or a corresponding ion exchange resin treatment system is started and the suspension with sufficiently ground ion exchange resin and a corresponding high concentration in the classified suspension is transported through the feed pipe 74 to the suction side of the second pump device 26.

[0055] It should be noted that in the schematic depiction of the figure, for ease of illustration, the necessary valves or measuring points are not included. However, it is well known and within the expertise of a person skilled in the art to make supplements, if necessary. Furthermore, all events and processes are controlled by a controller, which is also not shown in the figure. The controller may be the control system of the supercritical water oxidation or may be part of the control system of the ion exchange resin treatment system. [Explanation of symbols]

[0056] 10. Ion exchange resin treatment system 12 Oxidation reactor 14 Compressor 16 Air preheater 18 First Storage Container 20 First pump device 22 Second storage container 24 Ion exchange resin grinding system 26 Second pump device 28 Water supply equipment 30 Third pump device 32 Third Storage Container 34 Fourth Pump Unit 36 Fifth Pump Unit 38 Separation device 40 First Condenser 42 Condensate container 44 Ventilation elements 46 6th Pump Unit 48 Evaporation Apparatus 50 Second Condenser 52 Drum Dryer 54 Discharge device 56 Container 58 Feeding device 60 First stirring device 62 Second mixing device 64 Circulation Pump 66 Ion exchange resin grinding device 68 Extraction Pump 70 Classifier 72 Concentration measuring device 74 Supply pipe

Claims

1. An ion exchange resin treatment system (10) for treating radioactively contaminated ion exchange resin waste, comprising a supercritical water oxidation reactor (12) connected at its inlet side to an air supply device, a waste supply device, a fuel supply device, and a water supply device (28), and an ion exchange resin crushing system (24) connected upstream of the waste supply device for crushing the ion exchange resin to be treated until the ion exchange resin to be crushed falls below a predetermined ion exchange resin particle size, the crushed ion exchange resin being supplied to the waste supply device, the supercritical water oxidation reactor (12) connected at its outlet side to a separation device (38), the separation device (38) separating a mixture of gas and liquid obtained from the supercritical water oxidation reactor (12) into respective phases, the separated gas being supplied to a gas outlet element, and the separated liquid being supplied to a liquid outlet element, and a control device controlling at least the supercritical water oxidation reactor (12), the air supply device, the waste supply device, the fuel supply device, and the water supply device; The ion exchange resin crushing system (24) includes a container (56), from which a suspension consisting of a liquid and an ion exchange resin is extracted using a circulation pump (64) and supplied to an ion exchange resin crushing device (66), and through a conduit, the suspension consisting of the crushed ion exchange resin and the liquid is returned to the container (56), and the suspension is extracted from the container (56) by an extraction pump (68) and supplied to a classifying device (70), and the classifying device (70) separates ion exchange resin particles exceeding a predetermined ion exchange resin particle size from the suspension, and at least the separated ion exchange resin particles are returned to the container (56), and the remaining 1. An ion exchange resin treatment system (10) comprising: ion exchange resin particles in a liquid component having a particle size equal to or smaller than a predetermined particle size of the ion exchange resin, the ion exchange resin particles being supplied as a classified suspension to an outlet element of the classifying device (70); the classified suspension supplied by the classifying device (70) being supplied to a concentration measuring device (72), the concentration measuring device (72) determining a concentration value of the ion exchange resin particles in the suspension; the classified suspension being supplied for removal by a second pumping device (26) only when the determined concentration value is reached or exceeded in comparison with a predetermined concentration value; and when the determined concentration value is lower than the predetermined concentration value, the classified suspension being returned to the container (56).

2. 2. The ion exchange resin treatment system (10) of claim 1, wherein the concentration measuring device (72) is a density measuring device or a turbidity measuring device.

3. 2. The ion exchange resin treatment system (10) of claim 1, wherein the control device also controls the ion exchange resin crusher (66).

4. 2. The ion exchange resin treatment system (10) of claim 1, wherein caustic soda is stored in a third storage vessel (32), and the caustic soda is introduced from the third storage vessel (32) to the water supply device (28) as needed using a fourth pump device (34).

5. 2. The ion exchange resin treatment system (10) according to claim 1, characterized in that the separated gas is supplied from the gas outlet element to a first condenser (40), and the separated liquid is supplied from the liquid outlet element to an evaporator (48) depending on the components of the separated liquid, and then the water vapor is supplied from the evaporator (48) to a second condenser (50) or a drum dryer (52).

6. 6. The ion exchange resin treatment system (10) of claim 5, wherein the condensed water from the first condenser (40) and the condensed water from the second condenser (50) are supplied to a condensate container (42).

7. 7. The ion exchange resin treatment system (10) of claim 6, wherein water is sent from the condensate container (42) to a water supply (28) as needed.

8. 2. The ion exchange resin treatment system (10) of claim 1, wherein the vessel (56) has a first stirring device (60) equipped with a stirring element for homogenizing the distribution of ion exchange resin particles in the liquid in the vessel (56).

9. 2. The ion exchange resin treatment system (10) of claim 1, wherein the vessel (56) has a second agitator (62) equipped with a grinding agitation element capable of grinding ion exchange resin particles in the liquid in the vessel (56).

10. 1. A method for treating radioactively contaminated ion exchange resin, comprising the steps of: - grinding the radioactively contaminated ion exchange resin until the ion exchange resin particles in the suspension of liquid and ion exchange resin in the container (56) are below a predetermined particle size and provided as a classified suspension; - taking off a further partial stream of the classified suspension and monitoring the concentration value of the ion exchange resin particles in the further partial stream, preparing the classified suspension for removal by the second pumping device (26) only if the determined concentration value is reached or exceeded in comparison with a specified concentration value; - feeding air and a suspension of fuel, water and pulverized ion exchange resin into a supercritical water oxidation reactor (12) as a classified suspension having at least a certain concentration value; - controlling the amounts of air, fuel, water and pulverized ion exchange resin fed to the supercritical water oxidation reactor (12), so that all organic components in the suspension are decomposed by the supercritical water oxidation reactor (12) into a mixture of gas containing carbon dioxide and water vapor and a liquid containing water and dissolved or liberated non-organic ions; - separating gas from said mixture; A method including:

11. 11. The method of claim 10, wherein caustic soda is optionally introduced into the water before the water is fed to the supercritical water oxidation reactor (12).

12. 11. The method according to claim 10, characterized in that the separated gas is dried in a first condenser (40) before being released into the environment.

13. 11. The method according to claim 10, characterized in that the liquid is fed to an evaporator (48) based on its content, which evaporates the water present in the liquid and feeds the moist residue to a drum dryer (52), after which the water vapor is condensed to water in a second condenser (50), or the liquid is fed directly to the drum dryer (52), in which the water present is removed from the liquid until a residue remains.

14. 11. The method according to claim 10, characterized in that water is sent from the first and / or second condenser (50) to a condensate container (42), and the water collected in the condensate container (42) is selectively sent to a wastewater treatment system or to a water supply device (28).

15. 11. The method according to claim 10, characterized in that the suspension of water and ion exchange resin particles in the vessel (56) is homogenized using a first stirring device (60).

16. 16. The method according to claim 15, characterized in that the ion exchange resin in suspension in the vessel (56) is pre-comminuted using a second stirring device (62).

17. 17. The method according to claim 15 or 16, characterized in that the homogenized suspension in the vessel (56) is transported to an ion exchange resin crusher (66) using a circulation pump (64), the ion exchange resin particles in the suspension are crushed in the ion exchange resin crusher (66), and the ion exchange resin particles, after passing through the ion exchange resin crusher (66), are returned to the vessel (56) as crushed ion exchange resin particles in the suspension.

18. 18. The method according to claim 17, characterized in that the suspension is transported from the container (56) to an ion exchange resin crushing device (66) and crushed in the ion exchange resin crushing device (66) for a predetermined time before an extraction pump (68) is activated, which supplies a partial flow of the suspension from the container (56) to a classifying device (70), the classifying device (70) separates ion exchange resin particles that exceed a predetermined ion exchange resin particle size from the suspension, the separated ion exchange resin particles are returned to the container (56) together with a portion of the suspension, and the remaining suspension having ion exchange resin particles with a size equal to or smaller than the predetermined ion exchange resin particle size is supplied to an outlet element of the classifying device (70).

19. 19. The method according to claim 18, characterized in that the remaining suspension is sent from the outlet element of the classifier (70) to a concentration measuring device (72), which determines the proportion of ion exchange resin particles in the suspension that are larger than a specified value for the ion exchange resin particle size, the suspension is returned to the container (56) when the specified value for said proportion is reached or exceeded, and the suspension is supplied for removal by the second pump device (26) when the specified value for said proportion is fallen below.

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