RU2719289C1 - Method and system for processing radioactive wastes - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: group of inventions relates to methods for processing radioactive waste contained in a matrix. Method for processing radioactive waste contained in a matrix by pyrolysis involves introducing radioactive wastes in a receiver into a reaction chamber in which a temperature atmosphere of T ≥ 200 °C containing water vapour is installed or is being installed, performing pyrolysis, removal of gases from reaction chamber, extraction of receivers from reaction chamber. Additionally, one stage is performed from the group: introduction of oxygen and/or CO₂ into the reaction chamber, adjustment of water vapour introduced into the reaction chamber, adjustment of oxygen introduced into reaction chamber, disconnection of pyrolysis depending on oxidised substance available in exhaust gas. There is also a system for processing radioactive waste contained in a matrix.

EFFECT: group of inventions increases efficiency of pyrohydrolysis.

16 cl, 8 dwg

Description

The invention relates to a method for processing radioactive waste contained in a matrix. The invention also relates to a system for processing radioactive waste contained in a matrix.

In nuclear technology, such as in nuclear power plants or other industrial facilities using radioactive materials, inorganic and organic radioactive contaminated wastes arise that must be disposed of. These include, for example, ion exchangers, evaporation concentrates, sludge, metal components, rubber, plastic or even clothing.

To dispose of the corresponding radioactive contaminated waste, they are usually placed in a container in which the radioactive waste is surrounded by a matrix, that is, enclosed in it. Moreover, in the past, it was assumed that when using bitumen as a matrix, a problem-free final burial can be carried out.

There is also the possibility of mixing waste and bitumen from the outside, for example using an extruder, and then loading it into barrels.

Bitumen is also used if the waste is not stored in barrels, but, for example, in containers or chambers, the so-called cells.

Repeated checks of the barrels have now shown that contrary to expectations, the waste decomposes due to radiolysis, so that the gas resulting from this leads to the fact that, due to increased pressure, the barrels can bulge and burst under certain circumstances. Thus, it is necessary that the radioactive waste contained in an appropriate manner is recycled. To do this, it is known to carry out processing by means of pyrolysis and water vapor, the so-called hydropyrolysis, as a result of which bitumen and organic components, as well as nitrates, are pyrolyzed, that is, in the reaction chamber, that is converted into gas, in order to subsequently supply waste afterburning gas.

However, the known methods reveal the disadvantage that the corresponding hydro-pyrolysis lasts a relatively long time in order to remove all the organic filling material, as well as the organic components of the radioactive waste.

DE 26 41 264 A1 relates to a method for the disposal of organic radioactive waste using pyrohydrolytic ashing. Products subjected to pyrohydrolysis are transported by ladles through the furnace. Water vapor recirculates in a closed pipe system. At the same time, in a closed furnace, water vapor treatment is carried out at a temperature between 600 and 1100 ° C.

The subject of DE 600 24 306 T2 is a method for treating radioactive graphite by reaction at temperatures above 350 ° C with gases containing superheated steam or water vapor.

From DE 28 19 059 A1 you can borrow a furnace for the ashing of the nuclear waste of fissile and reproducing substances. Superheated water vapor is used as the reaction gas for pyrohydrolysis.

From DE 26 28 169 A1 a method and apparatus for converting radioactive ion exchange resins into a storage form is known. For this, thermal decomposition is carried out below the temperature of evaporation or sublimation of bound harmful substances, and the temperature of 500 ° C is not exceeded.

The subject of US 2008/0039674 A1 is a method for processing hazardous waste stored in barrels. Pyrolysis is carried out to evaporate the organic substances present in the barrels, so that the resulting gases can be removed by means of a purge gas stream that passes through the pyrolysis chamber and fed to the steam reforming furnace.

US 6,280,691 B1 relates to a one-step process for the removal of nitric oxide compounds in particular from radioactive waste. For this, a reactor is used, which is divided into several zones, and according to an embodiment, oxidizing conditions prevail in the lowest zone due to the supply of superheated steam with oxygen, strongly reducing conditions in the middle zone and oxidizing conditions in the upper zone.

The subject of US 4,628,837 is a method for processing spent ion exchange resins, comprising a first step in which the spent ion exchange resin is pyrolyzed in an inert gas atmosphere and a decomposition gas created during the first pyrolysis is separated, and a second step in which the spent ion exchange resin, which passed the first step, undergoes pyrolysis in an oxidizing atmosphere, and the decomposition gas created during the second pyrolysis is separated.

DE 602 16 731 T2 discloses a waste treatment device with a distribution mixing chamber. In this case, the waste to be pyrolyzed is introduced directly into the reaction chamber, which expands to the bottom in the form of a truncated cone.

The technical solution according to DE 28 19 059 A1 is a furnace for transferring radioactive and reproduction nuclear materials into ash, which are introduced into the annular gap of the furnace using a conveying device for transferring them to ash using pyrohydrolysis.

For melting carbon-containing, radioactively contaminated materials, WO 94/22604 A1 provides that carbon-containing materials are introduced into the reaction chamber, and oxygen can be introduced directly into the slag formed during melting using an oxygen lance.

Based on this, the objective of the present invention is a method of processing prisoners in a matrix of radioactive waste using pyrolysis, which includes the steps of:

- the introduction of the radioactive waste located in the receiver into the reaction chamber in which the atmosphere containing water vapor temperature T with T≥200 ° C is installed or is installed,

- performing pyrolysis,

- the removal of gases (waste gas) from the reaction chamber,

- removing the receivers from the reaction chamber,

improve in such a way that highly effective pyrohydrolysis can be performed.

To solve the problem, it is proposed that at least one stage of the group is additionally performed:

- the introduction of oxygen and / or CO ₂ into the reaction chamber during pyrolysis, preferably in a sub-stoichiometric amount, if necessary in a maximum stoichiometric amount,

- adjustment of the water vapor introduced into the reaction chamber depending on the oxidizable substance in the waste gas,

- adjustment of oxygen and / or CO ₂ introduced into the reaction chamber depending on the substance to be oxidized in the waste gas,

- turning off the pyrolysis, depending on the oxidizable substance present in the waste gas,

- the targeted introduction of water vapor and / or oxygen and / or carbon dioxide into the radioactive waste or into their region,

- targeted conduct of water vapor and / or oxygen and / or carbon dioxide inside the reaction chamber.

According to the invention, one or more additional measures are provided during pyrohydrolysis in order to convert evaporating radioactive waste into gas, as well as organic filling material. In particular, it is contemplated that oxygen and / or CO ₂ is introduced into the reaction chamber during pyrolysis, the oxygen fraction being preferably sub-stoichiometric, if necessary to the maximum stoichiometric.

It is possible that the introduced water vapor, which must have a temperature that corresponds to the temperature in the reaction chamber, is regulated depending on the substance being oxidized in the off-gas (pyrolysis gas). The conditions for the adjustment process are created.

Appropriate adjustment can also be made for the input fraction of oxygen and / or CO ₂ .

In order to eliminate the danger of an explosion in particular, it can additionally or alternatively be provided that the pyrolysis is switched off depending on the oxidizable substance present in the waste gas.

In particular, it can be provided that superheated water vapor or superheated water vapor with O ₂ and / or CO _{2 is} purposely introduced in the region of the reaction chamber, that is, inside the furnace in which the radioactive waste is located. In particular, it is envisaged that if the waste is in a container, such as a standard barrel, water vapor is introduced directly into the container, namely, it is preferable through openings for perforating the containers made before introducing the containers into the reaction chamber or through another opening made in the vessel wall or, for example, through the opening of a container without a lid.

Further, water vapor can be purposefully recycled inside the reaction chamber, as a result of which a volume flow is created that corresponds to multiple supply.

The invention is also characterized in that the atmosphere in the reaction chamber is swirled by one or more fans. The fan or fans may be rotationally driven in the reaction chamber by an introduced gaseous fluid, such as water vapor and / or O ₂ and / or CO ₂ .

It should further be noted that the reaction chamber may be the interior of a simple chamber furnace.

In particular, it is contemplated that radioactive waste that is contained in an organic matrix such as bitumen, epoxy resin, amino-aldehyde resin is processed.

It is also possible to recycle waste in an inorganic matrix such as cement. And although complete pyrolysis is not carried out, that is, the transformation into a matrix gas. However, waste due to pyrolysis becomes inert.

The invention is naturally not limited to the fact that there was a homogeneous mixing of radioactive waste with bitumen. Also, heterogeneous conclusion in the matrix can be carried out. This applies in particular to metals, structural materials, animal carcasses or glass that are filled with matrix material such as bitumen.

If the radioactive material is poured in particular with a matrix in a container, such as a standard barrel, for example a 200 liter barrel, part of the large storage facilities, the so-called cells, which are located in the reaction chamber on suitable receiving elements, can also be pyrolyzed.

It is also possible to melt or remove, at first, before pyrolysis, at least a portion of the matrix, which is then burned separately.

Regardless of the fact that when using barrels, they are perforated before being introduced into the reaction chamber.

Containers with enclosed radioactive waste, as a rule, are first delivered to the shielded loading space, in order to remove the lid of the container and manipulate the perforation in the circumferential wall. For this, the containers are located on the carriers, by which the containers are fed through the loading space, the reaction chamber (furnace) following it, and then into the sorting space following it. Subsequently, the media can be reused.

At the same time, carriers that have the geometry of the bathtub are made with such dimensions that the entire contents of containers or barrels can be accommodated.

Inside the reaction chamber, a temperature is set in particular between 200 ° C and preferably 800 ° C. Superheated water vapor is then fed into the chamber.

According to the invention, additional oxygen and / or CO ₂ can be supplied to the reaction chamber. The oxygen content is in particular sub-stoichiometric, if necessary up to the maximum stoichiometric.

In order to carry out pyrolysis purposely in the field of radioactive waste, according to a particular proposal of the invention, it is provided that a gaseous fluid such as water vapor and / or O ₂ and / or CO ₂ is purposely carried out in the reaction chamber. For this, so-called steam mouthpieces can be used, which are made in the form of nozzles through which water vapor is introduced into the reaction chamber. The nozzles simultaneously aspirate the atmosphere from the reaction chamber, so that an internal circulation is created and thus a volume flow that corresponds to multiple flows.

Nozzles work like venturi nozzles.

Additionally or alternatively, it is possible to introduce water vapor or water vapor and O ₂ and / or CO ₂ through nozzles or spray heads directly into the containers, that is, where the radioactive waste is located. For this purpose, rod elements, such as spears, which at the end have a gaseous fluid-emitting nozzle or a spray head, which is introduced into it through the barrel opening, can be used.

It goes without saying that there are further possibilities in order to conduct, such as mixing, the atmosphere inside the reaction chamber. Fans that are driven by steam themselves could even be used.

A line of waste gas leaves the reaction chamber, which leads to afterburning. Before entering the waste gas into the afterburning, the proportion of oxidizable substances is determined. The higher this fraction, the higher the content of organic substances not yet subjected to pyrolysis. This can be established, for example, by determining the thermal effect of the reaction during oxidation of the waste gas. Depending on the content of organic substances, the steam supply or the temperature in the reaction chamber or the supply of oxygen or CO ₂ can then be controlled.

In the afterburn itself, the waste gas is mixed with air and burned. After exiting the afterburn, oxygen is measured. It should be kept at a constant value, such as from 5% to 7%, in particular by 6%. In order to establish a constant value of the oxygen content of the gas exiting the afterburning, the air supplied to the afterburning is adjusted accordingly. According to the invention, in this case, it is provided that, depending on the supplied air, the temperature and / or the supply of water vapor and / or the supply of oxygen or CO ₂ to the reaction chamber, i.e. inside the furnace, or even shutdown is controlled, in order to exclude, for example, explosion hazard.

The amount of air supplied for afterburning is a measure of the combustible component present in the pyrolysis gas, such as organics, H ₂ , CO.

According to a particular embodiment, the invention is therefore distinguished by the method of adjusting the water vapor and / or O ₂ and / or CO ₂ and / or CO ₂ supplied to the reaction chamber and / or the temperature in the reaction chamber by determining the air supplied for afterburning, the oxygen of the gas extracted from the afterburning being kept constant or almost constant.

Also, the invention is distinguished by a method of adjusting the water vapor and / or O ₂ and / or CO ₂ and / or the temperature in the reaction chamber supplied to the reaction chamber by determining the substance burned in the pyrolysis gas.

In particular, the invention differs according to a particular embodiment in that the adjustment of the fluid supplied to the reaction chamber is redundant and manifold, that is, on the one hand, depending on the air supplied for afterburning, and on the other hand, on the oxygen content in the pyrolysis gas.

In this case, the gaseous fluid includes water vapor and / or O ₂ and / or CO ₂ , and if necessary, CO ₂ can be used instead of water vapor.

The invention is also characterized in that it is processed enclosed in an organic matrix, such as bitumen, epoxy resin, amino-aldehyde resin, radioactive waste.

Alternatively, it is contemplated that prisoners in an inorganic matrix, such as cement, radioactive organic waste are recycled.

In particular, the invention provides that the radioactive waste is introduced into a container, such as a container, in particular a 200-liter standard barrel, open, in particular with a hole on the circumferential side, with a rod element passing through the hole, such as a spear, water vapor is injected directly into the area of radioactive waste.

A further possibility provides that a gaseous fluid, such as at least water vapor, is introduced into the reaction chamber through a suction nozzle from the reaction chamber, such as a Venturi nozzle.

Additionally or alternatively, it is contemplated that a gaseous fluid, such as at least water vapor, is conducted inside the reaction chamber in such a way that the radioactive waste or matrix is intentionally loaded with water vapor.

In particular, the invention is also characterized in that the waste gas is supplied for afterburning, and before the afterburning of the waste gas, its oxidizable component is determined, and depending on the oxidizable component, the supply of a gaseous fluid such as water vapor and / or the supply of oxygen and / or CO ₂ into the reaction chamber and / or the temperature in the reaction chamber, the pyrolysis being also turned off during adjustment.

Alternatively or additionally, in particular, it is provided that the afterburning is carried out in the afterburning chamber into which the waste gas as well as the air is supplied, and that depending on the oxygen contained in the exhaust gas leaving the afterburning chamber, the air supply is regulated and the water supply is regulated depending on the air supply steam and / or the supply of oxygen and / or CO ₂ to the reaction chamber and / or the temperature in the reaction chamber, and pyrolysis is also turned off during adjustment.

The invention is also characterized in particular by a system for processing radioactive waste contained in a matrix, including a reaction chamber for performing pyrolysis, wherein the atmosphere and temperature T can be set in the reaction chamber with T≥200 ° C, in particular T> 400 ° C, preferably 400 ° C <T <800 ° C, and wherein a loading space is located in front of the reaction chamber, and a sorting space is located behind the reaction chamber, wherein at least one device is provided in the reaction chamber by which the mososphere can be recycled inside the reaction chamber, or the atmosphere can be intentionally introduced into the radioactive waste.

The atmosphere is, in particular, a steam-water atmosphere into which, if necessary, oxygen and / or carbon dioxide are purposefully introduced.

However, alternatively there is also the possibility that the water vapor is replaced by CO ₂ .

For reasons of simplification, it is hereinafter referred to in principle water vapor, despite the fact that - as explained above - other gaseous fluids can also form an atmosphere.

The device may be a nozzle through which water vapor can be supplied externally to the reaction chamber while aspirating the steam-water atmosphere from the reaction chamber. The Venturi principle is used.

Alternatively, there is the possibility that the device is a rod body, such as a spear, with a nozzle and / or a spray head, through which or which radioactive waste is directionally loaded with water vapor.

Mixing or swirling the atmosphere in the reaction chamber with one or more fans is equally possible.

The invention is also characterized in that the reaction chamber has an input for oxygen and / or carbon dioxide fed into the reaction chamber in a preferably sub-stoichiometric, if necessary maximum stoichiometric amount. This input may be that input through which steam is supplied to the reaction chamber.

There is also the possibility that the reaction chamber is connected to a waste gas combustion chamber, in front of which there is a measuring device for determining the oxidizable components in the waste gas, and / or behind which there is a measuring device for determining the oxygen contained in the exhaust gas leaving the afterburning chamber, the measuring device controls the amount of air supplied to the afterburner, which, for its part, is the regulating quantity for the amount supplied to the reaction gaseous fluid chamber and / or for a set temperature in the reaction chamber.

Further details, advantages, and features of the invention result not only from the claims and the features borrowed from it — individually and / or in combination — but also from the following description of preferred embodiments taken from the drawing.

The drawing shows:

FIG. 1 is a schematic diagram of a system for processing radioactive waste;

FIG. 2 - the first embodiment of the supply of water vapor into the reaction chamber;

FIG. 3 - a second embodiment of the supply of water vapor into the reaction chamber;

FIG. 4 - a third embodiment of the supply of water vapor into the reaction chamber;

FIG. 5 is a fourth embodiment of the supply of water vapor into the reaction chamber:

FIG. 6 is a fifth embodiment of supplying water vapor to the reaction chamber;

FIG. 7 - the first control loop; and

FIG. 8 - the second control loop.

In FIG. 1, a plant or system 10 for the processing of the radioactive waste contained in a matrix by means of pyrolysis is depicted purely in principle. In this case, the invention is described on the basis of hydro-pyrolysis, i.e., steam pyrolysis. However, CO ₂ can also be used instead of water vapor. For reasons of simplification, it is said, however, in the future, water vapor, although in this regard, water vapor can also be understood as a synonym for CO ₂ .

The system 10 includes a reaction chamber 40 at the disposal of the furnace 12, in particular a simple chamber furnace in which hydropyrolysis is performed. The furnace 12 is heated to a temperature preferably between 400 ° C and 800 ° C. Through the supply lines described hereinafter, superheated water vapor is then introduced into the furnace 12, the water vapor having a temperature being introduced when entering, which must correspond to the temperature inside the furnace. In front of the pyrolysis furnace 12 is a loading space 14, followed by a sorting space 16, both of which are shielded.

In particular, the furnace 12 is designed in such a way that at least at least four barrels 18 can be hydrolyzed at least.

In an exemplary embodiment, the processed radioactive waste is enclosed in a matrix which is located in barrels 18, without thereby limiting the technical solution according to the invention. Other organic matrix materials or even inorganic matrix materials are equally taken into account. Correspondingly filled barrels 18 are positioned in the front space 20 on the bath-like carriers 22, so that the manipulators 24, 26 can then be perforated in the loading space. The top cover is also removed.

Accordingly, the opening and the perforated containers 28 are then transported by the conveyor through the loading space 14 into the interior of the furnace 12, that is, into the reaction chamber 40 in which the hydro-pyrolysis is carried out. The reaction chamber and the interior of the furnace are indicated at 40.

If necessary, it is also possible to melt the matrix in advance, in order to then move the container into the furnace 12. The molten matrix material is burned separately.

Above the furnace 12 is a steam supply line 30, from which lines 32, 34, 36, 38 extend, through which, if necessary, fans 33, 35, 37, 39 supply steam to the interior 40 of the furnace. Further, off-gas line 42 departs from the furnace 12, through which the pyrolysis gas is supplied for afterburning.

It is important that the water vapor comes close to the radioactive waste so that it can undergo pyrolysis, that is, turn into steam, organic components. In this case, we are talking about organic components, such as salts of organic acids, complexing substances, ion-exchange substances, etc. Inorganic constituents do not react, with the exception of nitrates. Inorganic inert materials include solid materials, for example, from salt concentrates, phosphates, sulfates or borates of sodium, calcium, etc.

In order for the water vapor to come sufficiently close to the waste converted into gas, in particular, measures are provided that can be taken from FIG. 2 to 4.

Thus, it is possible, through a spear 44 or a similarly acting element, which has a nozzle or a spray head 46 at its free end, to introduce water vapor directly into the container 28, that is, for example, by passing a perforation through the hole, as can be seen in FIG. 2.

According to the embodiment of FIG. 4, the corresponding spear is inserted through the opening of the container 28, which has been freed from the lid, into it, so that a direct release of water vapor takes place.

From FIG. 5, we can borrow a measure in which water vapor is introduced through openings 48, 49 into the interior 40 of the furnace 12 and is discharged in the furnace 12 by a nozzle 50, 51, which correspond approximately in function to a Venturi nozzle, i.e., water vapor flowing through the nozzle 50, 51 it draws in atmosphere from the interior 40 of the furnace 12, so that a circulation occurs, which is indicated by arrows 52. Thus, a large amount of water vapor enters the immediate area of the perforated and open containers 28, so that pyrolysis can be performed timally.

The invention does not leave, it goes without saying, also if water vapor is introduced in the usual way through the openings 54, 56 into the interior 40 of the furnace 12. To facilitate this, fans 33, 37 can be used (Fig. 3).

According to FIG. 6, the atmosphere present in the furnace 12 can be swirled by one or more fans 70. The fan or fans 70 are rotationally driven in the furnace 12 by introducing, for example, water vapor through the opening 72.

Further, it is possible to introduce oxygen or CO ₂ into the interior 40 (reaction chamber) of the furnace 12 through an unimaged input or through an input through which water vapor is introduced into the chamber 40, while the oxygen fraction is preferably sub-stoichiometric in order to prevent the risk of fire or the explosion.

Using FIG. 7 and 8, control loops are explained in order to set or control the amount of water vapor and / or oxygen and / or carbon dioxide supplied to the interior 40 or the temperature in the reaction chamber 40.

So in FIG. 8, the furnace 12 is purely illustrated in principle, which is connected to the afterburner chamber 74 via a waste gas line 42, into which air is supplied via line 76.

The oxygen content of the gas leaving the afterburning chamber 74 (line 78) is determined by the first measuring device 80, the air that is supplied via line 76 is set so that the oxygen content of the exhaust gas is constant or almost constant. The oxygen content should be approximately 6%. Depending on the amount of air supplied to the afterburning chamber 74, the quantity of gaseous fluid, that is, water vapor, which is supplied to the furnace 12, is regulated in turn, and the proportion of O ₂ and CO ₂ can also be controlled. This is indicated by compound 84.

There is a further measuring device 86 leading to the afterburning chamber 74 of the pyrolysis waste gas line 86 in order, for example, to determine the fraction of oxidizable components in the pyrolysis gas by measuring the thermal effect of the reaction during oxidation. This fraction can equally be used as a control value (compound 88) for the steam and / or oxygen and / or CO ₂ supplied to the furnace 12 and / or for setting the temperature in the furnace 12.

In particular, both the amount of air supplied to the afterburning chamber 74 and the proportion of oxidizable components contained in the pyrolysis gas are used as control quantities, so that excessive and varied adjustments are possible.

Corresponding installation or adjustment may also be carried out depending on the air supplied for afterburning.

After the pyrolysis has been performed, the furnace 12 is cooled in order to feed the barrels to the sorting space 16, in which the remaining inorganic components are sorted and the barrels are cut by the manipulators 60, 62. These components are transferred according to a certain radioactivity in the tank 64, 66, 68, which are then disposed of in accordance with the relevant regulations.

The bath-like carriers 22 are returned back by the feeding device 70 to the loading space 14 for receiving new barrels 18, as follows from the image.

The invention also covers the case where instead of water vapor, CO _{2 is used} for pyrolysis.

Claims (29)

1. A method of processing a prisoner in a matrix of radioactive waste using pyrolysis, which includes the steps of: - the introduction of the radioactive waste located in the receiver into the reaction chamber in which the atmosphere containing water vapor temperature T with T≥200 ° C is installed or is installed, - performing pyrolysis, - the removal of gases (waste gas) from the reaction chamber, - removing the receivers from the reaction chamber, and additionally perform at least one stage from the group: - the introduction of oxygen and / or CO ₂ into the reaction chamber during pyrolysis in a sub-stoichiometric or maximum stoichiometric amount, - adjustment of the water vapor introduced into the reaction chamber depending on the oxidizable substance in the waste gas, - adjustment of oxygen and / or CO ₂ introduced into the reaction chamber depending on the substance to be oxidized in the waste gas, - turning off the pyrolysis, depending on the oxidizable substance present in the waste gas, - the targeted introduction of water vapor, and / or oxygen, and / or CO ₂ into radioactive waste or into their region, - purposefully conducting water vapor and / or oxygen and / or CO ₂ inside the reaction chamber. 2. The method according to p. 1, characterized in that they process radioactive waste contained in an organic matrix, such as bitumen, epoxy resin, amino-aldehyde resin. 3. The method according to p. 1 or 2, characterized in that they process radioactive waste contained in an inorganic matrix, such as cement. 4. The method according to any one of paragraphs. 1-3, characterized in that the radioactive waste is introduced into the open, in particular with openings, containers, such as containers, in particular 200-liter standard barrel, and using a rod element passing through the opening having a spray head or nozzle, such as a spear, at least water vapor is introduced into the radioactive waste, optionally additional O ₂ and / or CO ₂ . 5. The method according to any one of paragraphs. 1-4, characterized in that water vapor is introduced into the reaction chamber through a suction nozzle from the reaction chamber, such as a Venturi nozzle. 6. The method according to any one of paragraphs. 1-5, characterized in that the atmosphere in the inner space is mixed with at least one fan, which is driven by the steam supplied to the inner space. 7. The method according to any one of paragraphs. 1-6, characterized in that the water vapor is conducted inside the reaction chamber in such a way that the radioactive waste or matrix is purposefully loaded with water vapor. 8. The method according to any one of paragraphs. 1-7, characterized in that the waste gas is supplied for afterburning, and before the afterburning of the waste gas, its oxidizable component is determined, and depending on the oxidized component, the supply of water vapor and / or the supply of oxygen and / or CO ₂ to the reaction chamber is controlled and / or temperature in the reaction chamber, wherein pyrolysis is turned off during adjustment. 9. The method according to any one of paragraphs. 1-8, characterized in that the afterburning is carried out in the afterburning chamber, into which waste gas is supplied, as well as air, and depending on the air supplied to the afterburning chamber, the steam supply and / or the oxygen and / or CO ₂ flow are regulated the reaction chamber and / or the temperature in the reaction chamber, wherein pyrolysis is also turned off during adjustment. 10. The method according to p. 8 or 9, characterized in that the adjustment of the water vapor supplied to the reaction chamber and / or the supply of O ₂ and / or CO ₂ and / or the temperature in the reaction chamber is redundant and manifold. 11. The method according to any one of paragraphs. 1-10, characterized in that the water vapor is replaced by CO ₂ . 12. A system for processing a radioactive waste contained in a matrix, including a reaction chamber, for performing pyrolysis, wherein the reaction chamber is configured to set an atmosphere and temperature T with T≥200 ° C, in particular T> 400 ° C, preferably 400 ° C <T <800 ° C, maximum 950 ° C, with a loading space located in front of the reaction chamber and a sorting space located behind the reaction chamber, characterized in that at least one device is provided in the reaction chamber by which it is possible to recirculate the atmosphere inside the reaction chamber and / or to allow the targeted introduction of a gaseous fluid such as water vapor and / or CO ₂ and / or O ₂ into the radioactive waste contained in the matrix and located in the receiver. 13. The system according to p. 12, characterized in that the device is a nozzle through which it is possible to supply gaseous fluid from the outside to the reaction chamber while simultaneously aspirating the atmosphere from the reaction chamber. 14. The system according to p. 12 or 13, characterized in that the device is a rod body, such as a spear, with a nozzle and / or spray head, through which or which provides the possibility of directional loading of radioactive waste with gaseous fluid. 15. The system according to any one of paragraphs. 12-14, characterized in that it is possible to supply a gaseous fluid, in particular superheated water vapor, through an inlet into the reaction chamber, and through this inlet or at least one additional inlet, it is possible to supply carbon dioxide and / or oxygen in an amount from sub-stoichiometric to the maximum stoichiometric. 16. The system according to any one of paragraphs. 12-15, characterized in that the reaction chamber is connected by a pyrolysis gas line to the afterburner, the pyrolysis gas line being connected to a first measuring device for determining oxidizable components in the pyrolysis gas, and / or a second line departing from the afterburning chamber, on which a second measuring device it is possible to measure the oxygen content discharged from the gas afterburner, and depending on the measured oxygen content, the amount of air supplied to the afterburner is controlled wherein the amount of air and / or the content of oxidizable constituents in the pyrolysis gas is or is a setting or regulatory value or setting or regulatory values for the gaseous fluid and / or oxygen and / or carbon dioxide supplied to the reaction chamber.

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