Method for manufacturing amorphous radioactive waste and apparatus directly used in its implementation, modified zeolite

Abstract

To enable the long-term detoxification of radioactive waste at low cost, amorphous materials related to radioactive waste are manufactured using modified zeolite derived from natural or synthetic zeolite. [Solution] The method comprises the steps of: producing a modified zeolite that has a crystalline structure by pre-treating a natural zeolite or synthetic zeolite having a crystalline structure with an acid treatment, or by performing an acid treatment and other treatment; adsorbing radioactive waste using the modified zeolite; sintering the modified zeolite that has adsorbed radioactive waste in a medium-to-low temperature furnace with a temperature controlled to be such that the temperature is such that the crystalline structure is destroyed and the temperature is such that the modified zeolite melts, to form an amorphous body; and cooling after sintering.

Description

[Technical Field]

[0001] This invention relates to a method for producing amorphous radioactive waste contained in contaminated water or air, or present in solid waste, as well as an apparatus directly used in carrying out the same, and modified zeolite. [Background technology]

[0002] Patent Document 1 discloses that the long-term storage of radioactive waste as a contaminant is supported by stabilizing the waste into a form that does not react or degrade over long periods of time, and that vitrification is a common accepted method for achieving this stabilization, in which nuclear waste is mixed with a glass-forming medium (e.g., soil or zeolite), heated to the melting point of the mixture, and as a result of cooling, the nuclear waste is effectively incorporated into the glass, reducing the possibility of leakage and exposure to the environment (paragraph 0005). It also discloses that this type of vitrification (amorphization) is known as ICV (trademark) (paragraph 0005).

[0003] Furthermore, Patent Document 2 discloses a method of incorporating radioactive waste as a hazardous substance into the pores of natural or synthetic zeolite, and then closing the pore openings by heating and calcining the zeolite surface while maintaining the crystalline structure. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-003341 [Patent Document 2] Patent No. 3379642 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, the mixture described in Patent Document 1 includes not only radioactive waste but also organic matter, PCBs, asbestos, etc., and since it is to be processed simultaneously (bulk processing of mixed waste), it is considered that the furnace temperature to reach the melting point of the mixture needs to reach 1500°C to 2000°C. In other words, ICV (trademark) heats and melts waste containing soil inside a container, but there is a similar technology called ISV (trademark) that heats and melts contaminated soil on-site (underground), and the Public Services and Procurement Canada fact sheet states that the aforementioned ISV technology heats and melts contaminants at temperatures between 1600°C and 2000°C. Here, high-temperature furnaces operating at 1500°C to 2000°C are expensive, costing 40 to 50 million yen per ton (in contrast, medium- and low-temperature furnaces operating at 900°C to 1100°C are inexpensive, costing 5 to 10 million yen per ton). Also, patent Reference 2 describes a method of sealing the pores of zeolite while preserving its crystalline structure without destroying it. As such, the crystalline framework (Al-O-Si) is maintained, and there is a possibility that the framework will gradually deteriorate over the long term, leading to leakage of PFAS. Furthermore, microcracks may form in the crystalline framework due to fire, geothermal energy, or chemical changes in the disposal environment, causing the sealed areas to reopen. Additionally, crushing and abrasion may expose new surfaces and pores, potentially leading to leakage of adsorbed radioactive waste.

[0006] This invention utilizes the duality of zeolite, which has two states for detoxifying radioactive waste: one in which the crystalline structure is maintained (adsorbing radioactive waste) and another in which the crystalline structure is destroyed (producing amorphous material). During sintering, the temperature is controlled in a region beyond the temperature range that maintains the crystalline structure (a region where the crystalline structure is destroyed and the zeolite does not melt).

[0007] The object of the present invention is to provide a method for producing amorphous radioactive waste, an apparatus for directly using this method, and a modified zeolite, which allows each of the following steps—adsorbing radioactive waste while the zeolite maintains its crystalline structure, and then amorphousizing the zeolite in a medium-to-low temperature furnace while destroying its crystalline structure—to be carried out at low cost. [Means for solving the problem]

[0008] To achieve the above objective, the method for producing amorphous radioactive waste according to the present invention involves a natural zeolite or synthetic zeolite having a crystalline structure, To improve the adsorption characteristics of radioactive waste As a pretreatment, at least Acid treatment of The process includes the steps of: producing a modified zeolite having the aforementioned crystalline structure; adsorbing radioactive waste using the modified zeolite; sintering the modified zeolite that has adsorbed the radioactive waste in a medium-to-low temperature furnace with controlled temperature so that the temperature is such that the crystalline structure is destroyed and the temperature is such that the modified zeolite melts, thereby forming an amorphous shape; and cooling after the sintering.

[0009] Preferably, the modified zeolite is a natural zeolite mainly composed of clinoptilolite that has undergone the aforementioned pretreatment, and the temperature-controlled temperature is lower than 1200°C, the temperature at which the modified zeolite melts. 900 The temperature range is ~1100℃.

[0010] Preferably, the modified zeolite is a natural zeolite mainly composed of clinoptilolite that has undergone the aforementioned pretreatment, and the temperature-controlled temperature is in the range of 1000 to 1100°C, which is lower than the 1200°C at which the modified zeolite melts.

[0011] Furthermore, preferably, as the pretreatment Furthermore Ion exchange treatment include.

[0012] Also, preferably, when the radioactive waste is cesium, the ion exchange treatment is sodium ion exchange treatment or ammonium ion exchange treatment.

[0013] Also, preferably, when the radioactive waste is strontium, the ion exchange treatment is calcium ion exchange treatment.

[0014] Also, preferably, when there are multiple types of the radioactive waste, as the pretreatment Furthermore ion exchange treatments different according to the types of the radioactive waste Includes.

[0015] Also, preferably, when the radioactive waste is cesium and strontium, the modified zeolite is, for cesium, as the pretreatment Furthermore sodium ion exchange treatment included and, for strontium, as the pretreatment Furthermore calcium ion exchange treatment Includes and there are two types.

[0016] Also, preferably, the acid treatment is a treatment using hydrochloric acid.

[0017] Also, preferably, when the radioactive waste is cesium, so that the gas generated by the desorption of the adsorbed cesium during the temperature rise process does not leak outside the furnace, the furnace is managed to be airtight and under negative pressure, and glass frit (SiO2—B2O3 system) is mixed with the modified zeolite and sintered in the furnace.

[0018] Also, preferably, the furnace is temperature-controlled to reach a constant temperature.

[0019] Also, preferably, the temperature of the furnace is detected using two-color thermometry.

[0020] Furthermore, preferably, when using the natural zeolite, the natural zeolite comprises clinoptilolite having a silica composition ratio of 4.5 to 5.5 with respect to alumina.

[0021] Furthermore, preferably, when using the natural zeolite, the natural zeolite comprises mordenite in addition to the clinoptilolite as the main component. Furthermore, preferably, when using the natural zeolite, the natural zeolite is cut into pieces of 3 mm to 5 mm in size to increase its specific surface area and supplied directly to the pretreatment. Furthermore, the present invention is an apparatus directly used for carrying out the method for manufacturing amorphous bodies related to the above-mentioned PFAS. The apparatus comprises a pre-processing unit for performing the pre-processing, and a furnace for sintering the modified zeolite produced by the pre-processing unit. Includes nothing. [Effects of the Invention]

[0022] According to the present invention, each of the following steps—adsorbing radioactive waste while the zeolite maintains its crystalline structure, and then amorphously reforming the zeolite in a medium-to-low temperature furnace while destroying its crystalline structure—can be performed at a low cost. [Brief explanation of the drawing]

[0023] [Figure 1] This is a flowchart illustrating the first treatment, acid treatment, performed as a pretreatment to produce modified zeolite from natural or synthetic zeolite. [Figure 2] This flowchart shows the process of producing modified zeolite from natural or synthetic zeolite, involving a first treatment (acid treatment) and a second treatment (ion exchange treatment). [Figure 3] This is a photograph showing natural zeolite (white-gray). [Modes for carrying out the invention]

[0024] Before describing each embodiment of the present invention with reference to the drawings, Figures 1 and 2 show the flow chart of the method for producing amorphous materials according to the present invention. Figure 1 shows the case where a first treatment, acid treatment, is performed as a pretreatment for producing modified zeolite from natural zeolite, while Figure 2 shows the case where a first treatment, acid treatment, and a second treatment, ion exchange treatment, are performed as pretreatments for producing modified zeolite from natural zeolite. (First embodiment) In the case where the target to be adsorbed and neutralized is cesium, the following will be explained in the following order: natural zeolite with a crystalline structure as the raw material, modified zeolite obtained by pre-treating the natural zeolite, sintering in a medium-to-low temperature furnace, and the formation of amorphous material.

[0025] (Natural zeolite with a crystalline structure) Natural zeolites have an Al-O-Si skeleton, and the presence of Al creates a negative charge in the skeleton, so Na is used to neutralize it. + , K + It holds cations such as Ca+, and cesium ions (Cs) exchange with these cations. + It can adsorb. The natural zeolite used in this embodiment has a silica composition ratio of 4.5 to 5.5 to alumina, and contains mordenite in addition to clinoptilolite as the main component. The mixing ratio of clinoptilolite to mordenite is 9:1. It is then cut into pieces of 3 mm to 5 mm in size to increase its specific surface area, and supplied directly to the pretreatment described below. Here, a photograph of the natural zeolite (white-gray) used in this embodiment is shown in Figure 3.

[0026] (Modified zeolite) In this embodiment, the natural zeolite described above is subjected to acid treatment, or in addition to acid treatment, sodium ion Na is used as another treatment. + Exchange treatment or ammonium ion NH4 + The zeolite undergoes a replacement process. Modified zeolite that has undergone this pretreatment can adsorb more cesium than natural zeolite itself is used for cesium adsorption.

[0027] In particular, as a pretreatment, in addition to acid treatment, sodium ions Na + exchange treatment or ammonium ions NH4 + When the exchange treatment is performed, compared with the case where only acid treatment is performed, for sodium ions Na + When the sodium ion exchange treatment is performed, Na + is more likely to be exchanged with Cs + and an improvement in the cesium adsorption amount can be expected. When the ammonium ion NH4 + exchange treatment is performed, an improvement in the cesium adsorption amount cannot be expected, but it can be expected that impurity ions can be removed without leaving any in the sintering process.

[0028] (Sintering in a medium- and low-temperature furnace) The modified zeolite adsorbed with radioactive waste is sintered in a medium- and low-temperature furnace with temperature control as described below. The modified zeolite adsorbed with radioactive waste has its crystal structure destroyed, but remains amorphous (non-crystalline) while still adsorbing radioactive waste.

[0029] Regarding temperature control, the temperature is detected using a two-color thermometer measurement method, and heating and non-heating are controlled so that the temperature is between a first temperature (the minimum temperature at which the crystal structure of the modified zeolite of the present embodiment is destroyed, i.e., the non-crystallization temperature) as the lower limit value and a second temperature (a temperature lower than 1200°C, which is the temperature at which the modified zeolite of the present embodiment melts) as the upper limit value.

[0030] In the present embodiment, for the modified zeolite using natural zeolite mainly composed of clinoptilolite described above, the second temperature as the upper limit value is set to 1100°C, and the first temperature as the lower limit value is further set to 900°C.

[0031] By controlling two points in this way—an upper limit (second temperature) and a lower limit (first temperature)—the temperature range can be controlled to 900-1100°C, and even further to 1000-1100°C. However, it is also possible to control the temperature to a single point within this temperature range, that is, a constant temperature in the temperature range between the first and second temperatures (for example, 1000°C or 1050°C). In the aforementioned Patent Document 1, not only radioactive waste but also organic matter, PCBs, asbestos, etc., were included and were to be processed simultaneously (bulk processing of mixed waste), requiring a high-temperature furnace (1500°C to 2000°C). However, in this embodiment, a low-cost, small furnace (temperature controlled to 900°C to 1100°C) is sufficient. (Generation of amorphous forms) The amorphous bodies produced by sintering in a medium-to-low temperature furnace can be cooled after sintering and collected as general waste (recyclable waste), or further disposed of at a dedicated treatment plant (e.g., buried underground). (Regarding furnaces and sintering, considering the possibility of desorption during the heating process) In this case, if the possibility of adsorbed cesium desorption during the heating process is considered, it is preferable that the furnace be sealed and controlled under negative pressure to prevent gases generated by desorption from leaking outside the furnace, and that glass frit (SiO2-B2O3 system) be mixed with the modified zeolite and sintered in the furnace. (Regarding the removal of amorphous objects, considering the possibility of detachment during the heating process) Furthermore, if there is a possibility that cesium desorbed from the modified zeolite during the heating process is present in the furnace, it is preferable to remove the sintered and amorphous modified zeolite from the furnace by remote operation.

[0032] In other words, if there is a possibility that cesium may desorb (vaporize or aerosolize) from the modified zeolite even when the reactor is under negative pressure, then, for safety reasons, the following measures for radioactive waste are preferable when removing the sintered modified zeolite from the reactor.

[0033] • Dual compartment transfer using airlock + hot cell (shielding cell) The material is transferred from the furnace (melting chamber) to an airlock (small chamber), and then to a hot cell, where it is operated remotely using a crane. This prevents direct exposure during manned work and reduces air escape.

[0034] • Cool and seal the molten material (crucible) in a sealed container. After melting, the crucible is placed inside the furnace into a sealed liner container (such as a stainless steel can) and cooled while maintaining airtightness inside and outside the furnace. Once sufficiently cooled, the container is permanently sealed by welding / flanging and gasket and removed. This suppresses secondary radiation during cooling.

[0035] • The transfer system maintains negative pressure + double filter (primary gas barrier). To prevent atmospheric leakage during transfer, transfer lines and airlocks are designed to maintain a negative pressure lower than that of the furnace at all times and to have double barriers (for example, the airlock is kept under constant negative pressure and exhausted to a separate room).

[0036] • Remote crane and robot operation, shielding overpack The removed sealed container is immediately placed in a shielded overpack (a transport container with shielding material such as lead or concrete), sealed in a hot cell, and then transported out after radiation measurement.

[0037] • Standby management during retrieval (local exhaust, HEPA) and continuous monitoring The area around the removal work site will be kept under negative pressure by local exhaust (hood), and waste will pass through an off-gas treatment system (HEPA, etc.). During removal, real-time radioactivity monitoring and air sampling will be performed continuously.

[0038] (Safety measures for off-gases vaporized in the furnace, considering the possibility of desorption during the heating process) The process involves off-gas treatment steps: suspended particles → condensation → capture and compression → final filtration. Typical configurations and purposes are shown below. • A hood (bonnet) is installed above the furnace to recover fuel under constant negative pressure. The hood around the furnace is made negatively pressurized to forcibly recover off-gases. This suppresses their diffusion from the area around the furnace. • Removal of coarse particles and droplets by primary dust removal (cyclone / demister) Particulate matter is collected first to reduce the load on subsequent equipment. • Condensation and collection of vaporized cesium using a cooling / cold trap (condenser). Cesium is not completely non-volatile and can volatilize or move as chlorides depending on the conditions. Therefore, the off-gas is rapidly cooled to condense the vapor and collect it in a cold trap. The cold trap uses water cooling or a low-temperature medium to recover the vapor components as a liquid or solid phase. • Wet scrubber (liquid phase absorption) / Dust scrubber After cooling, the gas is scrubbed with an acidic or alkaline cleaning solution to transfer soluble cesium compounds and fine particles into the solution. • Final filter Particulate matter remaining in the gas phase is collected by a HEPA filter. HEPA filters have extremely high removal efficiency for particulate cesium (aerosol). (Second embodiment) In the case where the target to be adsorbed and neutralized is strontium, the following will be explained in the following order: natural zeolite with a crystalline structure as the raw material, modified zeolite obtained by pre-treatment of the natural zeolite, sintering in a medium-to-low temperature furnace, and the formation of amorphous material. (Natural zeolite) The natural zeolite with a crystalline structure used as the raw material is the same as that described in the first embodiment. (Modified zeolite) In this embodiment, the natural zeolite described in the first embodiment is subjected to acid treatment, or in addition to acid treatment, calcium ion Ca is added as another treatment. ++ The zeolite undergoes a replacement process. Modified zeolite that has undergone this pretreatment can adsorb more strontium than natural zeolite itself is used for strontium adsorption.

[0039] In particular, as a pretreatment, in addition to acid treatment, calcium ion Ca ++ When replacement treatment is performed, more strontium can be adsorbed compared to when only acid treatment is performed. (Sintering in a medium-to-low temperature furnace) Unlike cesium, strontium does not desorb during the heating process. Therefore, it is not necessary to take the safety measures that assume desorption as described in the first embodiment. However, since it is radioactive waste, it is also possible to take safety measures that assume desorption. (Generation of amorphous forms) This is the same as described in the first embodiment. (Third embodiment) The present invention is also applicable when the target to be adsorbed and rendered harmless is multiple types of radioactive waste. Here, using the example of multiple types of radioactive waste being cesium and strontium, the following will be explained in the order of natural zeolite having a crystalline structure as a raw material, modified zeolite obtained by modifying natural zeolite through pretreatment, sintering in a medium-to-low temperature furnace, and the generation of amorphous bodies. In this embodiment, since the targets to be neutralized are cesium and strontium, it combines the matters described in the first embodiment relating to cesium and the second embodiment relating to strontium.

[0040] (Natural zeolite with a crystalline structure) The natural zeolite with a crystalline structure used as the raw material is the same as that described in the first embodiment. (Modified zeolite) In this embodiment, where the adsorbed substances are cesium and strontium, two types of modified zeolite can be used: one that has been pretreated with acid treatment and Na ion exchange treatment (or ammonium ion exchange treatment) for cesium, and one that has been pretreated with acid treatment and Ca ion exchange treatment for strontium.

[0041] Alternatively, one type of modified zeolite can be used, which has undergone pretreatment using acid treatment, sodium ion exchange treatment (or ammonium ion exchange treatment), and calcium ion exchange treatment.

[0042] Furthermore, modified zeolites that undergo only acid treatment as a pretreatment can also be used. (Sintering in a medium-to-low temperature furnace) The same principles described in the first embodiment relating to cesium will be used. (Generation of amorphous forms) This is the same as described in the first embodiment. (Fourth embodiment) In the first to third embodiments described above, modified zeolite obtained by pre-treating natural zeolite was used, but synthetic zeolite can be used instead of natural zeolite, and modified zeolite obtained by pre-treating synthetic zeolite can also be used. Synthetic zeolites, like natural zeolites, are crystalline materials with a three-dimensional aluminosilicate (Al-Si-O) framework. This framework contains regularly arranged pores, channels, and cages, and these structures give rise to ion exchange and adsorption properties. Natural zeolites have advantages such as low cost, easy mass supply, relatively high mechanical strength and durability, and low environmental impact due to natural fluctuations. However, they also have disadvantages such as non-uniform crystal structure and chemical composition, unoptimized Si / Al ratio and pore size, and the presence of impurities. Synthetic zeolites overcome these disadvantages. Specifically, synthetic zeolites allow for arbitrary design of Si / Al ratio, pore size, and crystal form, enabling them to exhibit performance optimized for specific pollutants. Furthermore, they have a larger surface area and higher adsorption capacity than natural zeolites, as well as higher ion exchange capacity. In addition, as industrial products, their quality and performance are uniform. Moreover, their performance can be enhanced according to the purpose through organic modification (amine modification), metal ion exchange, acid treatment, etc. In this embodiment, where synthetic zeolites are used instead of natural zeolites, representative synthetic zeolites that can be used include zeolite Y(FAU), zeolite X(FAU), and zeolite A(LTA). In this embodiment, modified zeolite derived from synthetic zeolite can be used to adsorb the radioactive waste portion described in the first to third embodiments, and then sintered in a medium-to-low temperature furnace with a temperature controlled in the range of 900 to 1100°C to produce amorphous bodies related to radioactive waste. (Equipment used directly in the implementation of methods for manufacturing amorphous radioactive waste) This apparatus may include at least a pretreatment unit for pretreatment of natural or synthetic zeolite, and may also include a medium-to-low temperature furnace. (modified version) Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. For example, the modified zeolite derived from natural zeolite described in the first embodiment and the modified zeolite derived from synthetic zeolite described in the second embodiment may be mixed and used together.

[0043] Furthermore, while cesium and strontium were described as radioactive waste in the embodiments described above, other radioactive materials such as plutonium, cobalt, and radium can also be targeted for detoxification. For example, in the case of plutonium, natural or synthetic zeolite is treated with acid, and then aluminum (Al) is used. +++ Ion exchange treatment or iron Fe +++ Modified zeolite that has undergone ion exchange treatment has a higher plutonium adsorption capacity. In the case of cobalt, natural or synthetic zeolite is acid-treated, and then sodium Na is used. + Modified zeolite that has undergone ion exchange treatment has a higher cobalt adsorption capacity. In the case of radium, natural or synthetic zeolite is treated with acid, and then calcium ions (Ca) are added. ++ Exchange treatment or barium ion Ba ++ Replacement process, or aluminum Al +++ Modified zeolite that has undergone ion exchange treatment has a higher radium adsorption capacity.

Claims

1. A step of producing a modified zeolite that has the crystalline structure by subjecting a natural or synthetic zeolite having a crystalline structure to at least an acid treatment as a pretreatment to improve the adsorption properties of radioactive waste, The steps include adsorbing the radioactive waste using the modified zeolite, The modified zeolite that has adsorbed the aforementioned radioactive waste is used to The steps include: sintering the modified zeolite in a medium-to-low temperature furnace, where the temperature is controlled to be such that the crystal structure is destroyed and the temperature is lower than the temperature at which the modified zeolite melts, to form an amorphous body; The steps include: cooling the amorphous body after the sintering, A method for manufacturing amorphous radioactive waste, characterized by having [a certain characteristic].

2. The method for producing amorphous radioactive waste according to claim 1, characterized in that the modified zeolite is a natural zeolite mainly composed of clinoptilolite that has undergone the aforementioned pretreatment, and the temperature-controlled temperature is in the range of 900 to 1100°C, which is lower than the 1200°C at which the modified zeolite melts.

3. The method for producing amorphous radioactive waste according to claim 1, characterized in that the modified zeolite is a natural zeolite mainly composed of clinoptilolite that has undergone the aforementioned pretreatment, and the temperature controlled is in the range of 1000 to 1100°C, which is lower than the 1200°C at which the modified zeolite melts.

4. A method for producing amorphous radioactive waste according to claim 1, further comprising ion exchange treatment as the aforementioned pretreatment.

5. The method for producing amorphous radioactive waste according to claim 4, characterized in that, when the radioactive waste is cesium, the ion exchange treatment is sodium ion exchange treatment or ammonium ion exchange treatment.

6. The method for producing amorphous radioactive waste according to claim 4, characterized in that, when the radioactive waste is strontium, the ion exchange treatment is a calcium ion exchange treatment.

7. The method for producing amorphous radioactive waste according to claim 4, characterized in that, if the radioactive waste consists of multiple types, the pretreatment further includes different ion exchange treatments depending on the type of radioactive waste.

8. The method for producing amorphous radioactive waste according to claim 7, characterized in that, when the radioactive waste consists of cesium and strontium, the modified zeolite is of two types: one that further includes sodium ion exchange treatment as a pretreatment for cesium, and one that further includes calcium ion exchange treatment as a pretreatment for strontium.

9. The method for producing amorphous radioactive waste according to claim 1, characterized in that the acid treatment is a treatment using hydrochloric acid.

10. The method for producing amorphous radioactive waste according to claim 5, characterized in that, when the radioactive waste is cesium, the furnace is sealed and controlled under negative pressure to prevent gas produced by the desorption of adsorbed cesium during the heating process from leaking to the outside of the furnace, and glass frit (SiO2-B2O3 system) is mixed with the modified zeolite and sintered in the furnace.

11. The method for manufacturing amorphous radioactive waste according to claim 1, characterized in that the furnace is temperature-controlled to maintain a constant temperature.

12. The method for manufacturing amorphous radioactive waste according to claim 1, characterized in that the temperature of the furnace is detected using a two-color thermometer.

13. The method for producing amorphous radioactive waste according to claim 1, characterized in that, when using the aforementioned natural zeolite, the aforementioned natural zeolite comprises clinoptilolite having a silica composition ratio of 4.5 to 5.5 with respect to alumina.

14. The method for producing amorphous radioactive waste according to claim 13, characterized in that, when using the aforementioned natural zeolite, the aforementioned natural zeolite comprises mordenite in addition to the aforementioned clinoptilolite as the main component.

15. The method for producing amorphous radioactive waste according to claim 1, characterized in that when the natural zeolite is used, the natural zeolite is fragmented into pieces of 3 mm to 5 mm in size to increase its specific surface area and supplied as is to the pretreatment.

16. An apparatus for direct use in carrying out a method for manufacturing amorphous radioactive waste according to any one of claims 1 to 15, A pre-processing unit that performs the aforementioned pre-processing, A furnace for sintering the modified zeolite produced by the preprocessing unit, An apparatus characterized by having the following features.

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