JP6170649B2 - Radioactive organic waste volume reduction device and method of use thereof - Google Patents

Description

The present invention provides a volume reduction treatment for a large amount of soil, debris, etc., which is suitable for use when a wide range of forests and organic waste are contaminated with radioactive substances such as radioactive cesium due to an accident at a nuclear power plant, etc. The present invention relates to a device for performing the above and a method for using the same.
The present invention also relates to a volume reducing device for radioactive organic waste suitable for use in volume reduction treatment of low-level radioactive contaminants generated in association with operation of a nuclear power plant, and a method for using the same.

  When radioactive materials are extensively contaminated by an accident at a nuclear power plant, a large amount of soil, rubble, etc. must be treated. There are various types of radioactive pollutants, but for example, cesium 137 and strontium 90 currently account for most of the sources of radioactivity occurring in the area surrounding the Chernobyl nuclear power plant accident. Cesium 137 has a long half-life of 30 years. When it enters the body, it rides on the blood stream and emits beta and gamma rays to the intestines and liver. Is done. Cesium 137 emits beta rays and gamma rays from 100 days to 200 days after being taken into the body and discharged outside the body, causing internal exposure. Therefore, there is a strong demand for efficiently decontaminating radioactive cesium from contaminated soil.

  However, it is important to reduce the volume and weight of the contaminated soil because it is a large amount. Currently, nearly two years have passed since the reactor steam explosion. Therefore, iodine 131 of the radioactive substance has a short half-life of about 8 days, so that most of it is beta-decayed and changed to xenon 131 which is a stabilizing element. On the other hand, cesium 137 undergoes beta decay and changes to barium 137, which is a stabilizing element. However, in the current field of physics, the half-life of radioactive materials is considered to be unchanged in an environment where ordinary people live, and there is no catalytic substance that dramatically shortens the half-life. It is considered. In addition, cesium is known to bind strongly to soil, and it is difficult to separate it effectively at low cost.

For example, Patent Document 1 proposes a method for extracting cesium. However, Patent Document 1 relates to a technique for separating rubidium from porcite (Cs (AlSi ₂ O ₆ )), which is an economically important cesium source mineral. Currently, the amount of cesium mined from the world mine is 5 to 10 tons per year, and the harvestable period is several thousand years. Therefore, even if cesium is purposely separated from radioactively contaminated soil, No success is expected.
On the other hand, improvement of radioactively contaminated soil is also proposed in Patent Documents 2 and 3. However, the radioactive substances to be treated in Patent Documents 2 and 3 are intended for heavy metals such as plutonium and uranium, and are not intended for alkali metals such as cesium.
Moreover, although the low temperature thermal decomposition apparatus of organic waste is proposed by patent document 4 concerning this inventor's proposal, there is no description regarding cesium. Therefore, even if organic waste containing cesium is pyrolyzed at low temperature, it only reduces the volume of organic waste. Cesium remains in ash as a residue or volatilizes and moves to liquid waste. Should do.

Therefore, in Non-Patent Document 1, a separation method by in-situ heating of soil containing cesium is studied. However, when separating cesium from the soil, the following effects (a) and (b) are present, so that a remarkable effect cannot be obtained.
(A) Cesium dissolved in water behaves as a monovalent cation in the soil, and is taken in between the thin layered structure, which is a clay layer on the surface of negatively charged soil particles. And cannot be easily replaced by other cations.
(B) Even when the soil adsorbed with cesium is heated to 685 ° C., which is the boiling point of cesium, or about 1300 ° C. in consideration of the melting point and boiling point of the cesium compound, no significant volatilization behavior of cesium is observed.
On the other hand, Non-Patent Document 2 discloses a decontamination demonstration technique characterized by a high-performance reaction accelerator characterized by soil to be decontaminated and heat treatment as a method. According to the results of the verification test in the decontamination target area near the Fukushima nuclear power plant, the decontamination rate of the decontamination verification technology is 99.9%, which is much higher than wet classification, but the processing cost is also 200,000. There is a problem that the cost is more than 10 times as much as yen / ton.

JP-A-5-5134 JP-A-6-51096 Japanese National Patent Publication No. 10-505903 Japanese Patent No. 3872083

Japan Atomic Energy Agency JAEA-Research 2011-026 Report on Decontamination Demonstration Work in Evacuation Zones Related to Fukushima Daiichi Nuclear Power Plant Accident Japan Atomic Energy Agency June 2012

The present invention solves the above-mentioned problems, and a volume reduction device for radioactive organic waste that can reduce the processing cost significantly while rapidly reducing the volume of cesium 137 contained in organic waste and soil, and a method of using the same. The purpose is to provide.
Another object of the present invention is to provide a radioactive organic waste volume reduction device suitable for treating low-level radioactive contaminants generated in connection with the operation of a nuclear power plant, and a method for using the same. .

The apparatus for reducing the volume of radioactive organic waste of the present invention that solves the above problems includes, as shown in FIG. 1, for example, a pyrolysis chamber 19 in which organic waste is pyrolyzed at a low temperature pyrolysis temperature, and organic waste. A low-temperature pyrolysis apparatus having a firebed holding unit 18 for holding a firebed for thermally decomposing an object at a low-temperature pyrolysis temperature, and an organic dry porous material for forming a firebed in the pyrolysis chamber 19 Means (91, 94) for supplying a pyrolysis temperature holding material 92 comprising the above, and means (98, 94) for supplying the pyrolysis chamber 19 to the pyrolysis chamber 19 in an autonomous pyrolysis state having a temperature equal to or higher than the pyrolysis temperature. 94) , the organic waste contains a radioactive substance, and the firebed holding unit 18 is placed with a predetermined thickness of zeolite ore, and circulates the exhaust gas from the pyrolysis chamber 19 to circulate the pyrolysis chamber 19. A gas circulation system 80 is provided.

According to the radioactive organic waste volume reducing device of the present invention, in the low temperature pyrolysis device 10, the organic waste is thermally decomposed at the low temperature pyrolysis temperature in the thermal decomposition chamber 19. The fire bed holding unit 18 holds a fire bed for thermally decomposing organic waste at a low temperature pyrolysis temperature. Zeolite ore is placed in the firebed holding part 18 with a predetermined thickness. The predetermined thickness may be a thickness suitable for maintaining a low temperature pyrolysis temperature of the organic waste, for example, a thickness of 1 mm to 20 cm. If the thickness of the zeolite ore is less than 1 mm, heat is leaked to the outside of the apparatus due to heat transfer in the fire bed holding unit 18, and it becomes difficult to maintain the organic waste at a low temperature pyrolysis temperature. The efficiency of volume reduction is reduced. When the thickness of the zeolite ore is larger than 20 cm, the amount of the zeolite ore is increased as compared with the organic waste, and the efficiency of reducing the volume of the organic waste is lowered.
The gas circulation system 80 circulates the exhaust gas from the pyrolysis chamber 19 and supplies it to the pyrolysis chamber 19 in order to maintain the inside of the pyrolysis chamber 19 at a low temperature pyrolysis temperature. By circulating the exhaust gas, a low-oxygen state gas is supplied to the thermal decomposition chamber 19, and the oxidation rate of the organic waste is appropriately controlled. Balance of heat dissipation makes it easy to maintain the low temperature pyrolysis temperature.
The pyrolysis temperature maintaining material 92 is an organic dry porous material used to form a fire bed required at the start of operation of the low temperature pyrolysis volume reducing device. The seed flame holding material 99 is in an autonomous pyrolysis state having a temperature at least equal to or higher than the pyrolysis temperature, and is put into the pyrolysis chamber 19 filled with the pyrolysis temperature holding material to operate the low temperature pyrolysis volume reducing device. It becomes a fire that forms the necessary fire bed at the start.

In the radioactive organic waste volume reducing device of the present invention, the pyrolysis chamber 19 preferably has a pyrolysis gas outlet 26 for discharging the pyrolyzed gas of the organic waste that has been pyrolyzed, and gas circulation. The system 80 may return the cleaned gas obtained by cleaning the pyrolysis gas with moisture, and the pyrolysis chamber 19 may further include a gas supply port 25 for sucking the cleaned gas into the pyrolysis chamber.
With this configuration, since the pyrolysis gas has been washed with moisture, moisture, hydrocarbon oil, and dust accompanying the pyrolysis of organic waste are removed, and oxygen content is suitable for pyrolysis of organic waste. A less cleaned gas is supplied. Therefore, radioactive materials contained in organic waste circulate in the volume reduction device and do not leak to the external space.

In the radioactive organic waste volume reducing device of the present invention, preferably, the low-temperature pyrolysis temperature is approximately in the range of 200 ° C. to 300 ° C. as the temperature of the organic waste thermally decomposed in the pyrolysis chamber 19. Good. If the temperature of the organic waste to be pyrolyzed in the pyrolysis chamber 19 is approximately 200 ° C. or less, it becomes easy to cool by heat dissipation, the pyrolysis reaction tends to become slow, the pyrolysis reaction stops, and the pyrolysis reaction becomes stable. Continuation is difficult. When the temperature of the organic waste to be pyrolyzed in the pyrolysis chamber 19 is approximately 300 ° C. or more, the pyrolysis reaction is likely to be accelerated rapidly, the low-temperature pyrolysis temperature rises, and it is difficult to stably continue the pyrolysis reaction. It becomes.

In the radioactive organic waste volume reducing device of the present invention, preferably, the magnetic generation means 85 for generating a magnetic field, and the magnetism generated by the magnetic generation means 85 for guiding the magnetism generated by the magnetic generation means 85 to the firebed holding unit 18 are further described. It is preferable to have a high permeability member 24 made of a material having ferromagnetism at a low temperature pyrolysis temperature. Preferably, the high magnetic permeability member 24 may also serve as a wall material for a gas ventilation part provided in the lower part of the firebed holding part 18.
With this configuration, the high permeability member 24 guides the magnetism generated by the magnetism generating means 85 to the firebed holding unit 18, so that the magnetic field formed in the pyrolysis chamber 19 including the firebed holding unit 18 is generated. It seems to be stronger and beneficial for the decay of radioactive materials in organic waste. Further, when the high magnetic permeability member 24 also serves as a wall material of the gas ventilation part provided at the lower part of the firebed holding part 18, the gas circulating in the thermal decomposition chamber 19 receives the magnetic action of the magnetic generation means 85, This has the effect of increasing the gas flow rate.

In the radioactive organic waste volume reducing device of the present invention, it is preferably provided between the stock yard 14 for temporarily storing the seed-fire holding material to be put into the pyrolysis chamber 19, and between the pyrolysis chamber 19 and the stock yard 14. In addition, the seed yard partition plate 17 is provided, and the seed fire holding material stored in the stock yard 14 may be configured to fall in small amounts with respect to the surface of the pyrolysis temperature holding material accommodated in the pyrolysis chamber 19. . If comprised in this way, since the stock yard 14 stores the seed-fire holding material temporarily, when the pyrolysis temperature holding material is accommodated in the pyrolysis chamber 19, the seed-fire holding material is put on the surface of the pyrolysis temperature holding material. On the other hand, by dropping every small amount, it becomes easy to deposit the seed fire holding material on the surface of the pyrolysis temperature holding material with a uniform thickness.
In the radioactive organic waste volume reducing device of the present invention, it is preferable that the radioactive substance contains at least one of cesium 134 and cesium 137.

The method of using the volume reducing device for radioactive organic waste according to the present invention that solves the above-described problems includes, for example, as shown in FIG. 4, a pyrolysis chamber 19 in which organic waste is pyrolyzed at a low temperature pyrolysis temperature, A method of using a low-temperature pyrolysis apparatus having a fire bed holding unit 18 for holding a fire bed for pyrolyzing organic waste at a low temperature pyrolysis temperature, for forming a fire bed in a pyrolysis chamber 19 A step (S104, S106) of supplying a pyrolysis temperature holding material 92 made of the organic dry porous material, and an autonomous pyrolysis seed fire holding material having a temperature at least equal to or higher than the pyrolysis temperature in the pyrolysis chamber 19 99 (S110, S114), a step (S118) of stably maintaining the thermal decomposition of the pyrolysis temperature holding material 92 by the seed fire holding material 99 in the pyrolysis chamber 19, and a pyrolysis temperature holding material. After 92 pyrolysis stabilization steps , Supplying organic waste to be subjected to low-temperature pyrolysis to the pyrolysis chamber 19 (S120, S124), and reducing the volume of the organic waste and radioactive contained in the organic waste A step (S119) of maintaining the thermal decomposition temperature until the amount of the substance decreases.

According to the volume reduction device for radioactive organic waste of the present invention, the ore holding part has zeolite ore placed at a predetermined thickness, and circulates the exhaust gas from the pyrolysis chamber and supplies it to the pyrolysis chamber. Since it has a gas circulation system, the pyrolysis chamber is stabilized at the low temperature pyrolysis temperature, and the environment where the zeolite ore and the low temperature pyrolysis temperature act is promoted, so the decay of radioactive materials contained in organic waste is promoted. It is considered that a radioactive substance such as cesium 137 is rendered harmless, and a safe state is achieved, and reduction of radiation in a human living environment is promoted.
In addition, the radioactive substance processing method of the present invention is a generalization of a volume reduction device for radioactive organic waste and a method for using the same, and it does not harm radioactive substances such as cesium 137 in the presence of a magnetic field or zeolite ore. Process.

It is a block diagram explaining the whole structure of the volume reduction apparatus of the radioactive organic waste which concerns on this invention. It is a figure explaining the time of an operation start of the radioactive organic waste volume reduction apparatus of this invention. It is a figure explaining the time of an operation start of the radioactive organic waste volume reduction apparatus of this invention. It is a flowchart explaining the usage method of the volume reduction apparatus of the radioactive organic waste of this invention. It is a figure explaining the distribution state of surrounding space gamma dose rate at the time of thermal decomposition apparatus operation. It is a figure explaining the magnetic field distribution state in the non-operating state of a thermal decomposition apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram illustrating the overall configuration of a radioactive organic waste volume reducing device according to the present invention. In the figure, a volume reduction device 1 for radioactive organic waste includes a low-temperature pyrolysis device 10, a gas cleaning device 2, and a water supply system 70 and a gas circulation system 80 as pipes connecting the two. A gas-liquid separator 30 is installed on the low temperature pyrolysis apparatus 10 side. Further, water spray towers 50a and 50b and a liquid storage tank 60 are provided on the gas cleaning device 2 side. Further, a crane 94 is provided, and the organic dry porous material 92 and the seed fire holding material 99 are put into the low-temperature pyrolysis apparatus 10.

  The low-temperature pyrolysis apparatus 10 is a cylindrical or box-like container having an inlet 11 into which organic waste is introduced, a side wall 12 made of a heat-resistant material, and a base 13 for installation on the ground. It has a volume corresponding to the unit time processing capacity. The input port 11 is provided at the lid portion of the low-temperature pyrolysis apparatus 10, thereby facilitating the operation of inputting organic waste into the stock yard 14. The stockyard 14 has a first layer opening / closing lid 15 provided on the inlet 11 side and a second layer opening / closing lid 16 provided on the pyrolysis chamber 19 side. The first layer opening / closing lid 15 and the second layer opening / closing lid 16 perform an opening / closing operation in the horizontal direction (arrows A and B directions). In the state where the second layer opening / closing lid 16 is closed, the second layer opening / closing lid 16 acts as the stockyard partition plate 17.

  The stockyard partition plate 17 is a partition plate accommodated in a horizontal state inside the low-temperature pyrolysis apparatus 10. The stockyard 14 is formed on the upper side, and the pyrolysis chamber 19 is formed on the lower side. The internal temperature during steady operation of the pyrolysis chamber 19 is about 200 ° C. to 300 ° C. at maximum, but it is charged so as not to be damaged even when the organic waste is ignited and burned in the state of an incinerator. A heat resistant material such as a heat resistant steel plate may be used for the mouth 11, the side wall 12, and the stockyard partition plate 17.

The firebed holding unit 18 is a partition plate accommodated in a horizontal state inside the low-temperature pyrolysis apparatus 10 and holds the heat-retaining material 20 and the in-furnace organic waste 21 during the pyrolysis, and on the lower side. A gas ventilation section 24 through which the cleaned gas is ventilated is formed. The firebed holding unit 18 is formed with a number of nets or openings having a certain shape so as to hold the heat-retaining material 20 and the in-furnace organic waste 21 so as not to fall into the gas ventilation unit 24. The firebed holding unit 18 is preferably made of a ferromagnetic material such as iron and having a Curie temperature higher than the low temperature pyrolysis temperature (200 ° C. to 300 ° C.). A magnetic material generated by the permanent magnet unit 85 acts on the entire pyrolysis chamber 19 by using a ferromagnetic material for the conduits forming the fire bed holding unit 18, the gas supply port 25, and the gas ventilation unit 24.
The heat retaining material 20 is maintained at a temperature of about a low temperature pyrolysis temperature (200 ° C. to 300 ° C.), and has a certain particle shape such as zeolite ore. As the zeolite ore, for example, a powder having a large specific surface area may be used.

  Ferromagnetic structural materials such as iron may be used for the wall material of the pyrolysis chamber 19, the partition plate and lattice member of the firebed holding unit 18, and the tube material of the gas ventilation unit 24. Since the maximum internal temperature during steady operation of the pyrolysis chamber 19 is about 200 ° C. to 300 ° C., iron materials having inferior heat resistance can be used as compared with nickel steel and cobalt steel such as structural steel plates. A heat-resistant structural material such as a nickel steel plate or a cobalt steel plate may be used. The Curie temperature of iron is 770 ° C, the Curie temperature of nickel is 354 ° C, and the Curie temperature of cobalt is 1115 ° C. During the steady operation of the pyrolysis chamber 19, the temperature is a low temperature pyrolysis temperature, and the inside of the tube material of the gas ventilation unit 24 is affected by the magnetic field of the permanent magnet units 75 and 85, for example, about 0.05 Tesla to 0.3 Tesla. It is considered that the magnetic flux density is as follows. In addition, since the magnetic resistance is large outside the tube material of the gas ventilation unit 24, the magnetic flux density is reduced to an environmental magnetic field.

The distribution of the magnetic flux density is affected by the magnetic resistance of the wall material of the pyrolysis chamber 19, the partition plate and lattice member of the firebed holding unit 18, and the tube material of the gas ventilation unit 24. Therefore, in order to investigate the distribution of the magnetic flux density in the thermal decomposition chamber 19, the theory of a magnetic circuit is preferably used. Here, the basic calculation formula of the magnetic circuit is substantially similar to Ohm's law regarding the electric circuit. That is, if the total magnetic flux of the magnetic circuit is phi, the magnetomotive force is F, and the magnetic resistance is R, the following relationship is established between the three.
[Total magnetic flux phi] = [magnetomotive force F] / [magnetoresistance R] (1)
The magnetic resistance R has the following relationship when the length of the magnetic path is L, the cross-sectional area of the magnetic path is A, and the magnetic permeability of the magnetic path is mu.
[Magnetic resistance R] = [Magnetic path length L] / {[Magnetic path cross-sectional area A] x [Permeability mu]} (2)
That is, the shorter the magnetic path length and the larger the magnetic path cross-sectional area and permeability, the smaller the magnetic resistance R. The relative permeability mu is based on the vacuum permeability. The normal permeability mu at room temperature is 250 for cobalt, 600 for nickel, and in the case of iron, depending on the type of steel. Between -7000.

  The pyrolysis chamber 19 is a space in which the organic waste supplied from the heat insulating material 20, the in-furnace organic waste 21 and the stock yard 14 is pyrolyzed at a low temperature pyrolysis temperature. It is formed in the middle of the partition plate 17. Since the supply of oxygen to the pyrolysis chamber 19 is limited to the cleaned gas supplied from the gas supply port 25, it is extremely less than the amount of oxygen required for the complete oxidation reaction of organic waste. Being hypoxic. Therefore, the organic waste is thermally decomposed into a lower hydrocarbon compound in which carbon monoxide and carbon chains are partially decomposed, and discharged from the pyrolysis gas outlet 26 as a pyrolysis gas of the organic waste.

  The residual deposited layer 22 is formed below the firebed holding unit 18, and the cleaned gas is passed through the gas ventilation unit 24 located between the residual deposited layer 22 and the firebed holding unit 18. In the residue deposition layer 22, the residue of the in-furnace organic waste 21 thermally decomposed in the thermal decomposition chamber 19 and the heat-retaining material 20 that has been atomized along with the thermal decomposition are deposited. Thermal analysis of the remaining components revealed that gypsum is the main component when the organic waste is wood or general household waste.

  The residue discharge port 23 is an opening through which the residue of the in-furnace organic waste 21 deposited on the residue deposition layer 22 and the heat-retaining material 20 that has been finely divided due to thermal decomposition are taken out. The gas supply port 25 is for supplying the cleaned gas supplied from the cleaning gas circulation pipe 84. The pyrolysis gas outlet 26 is provided on the side wall 12 located in the pyrolysis chamber 19 in the vicinity of the stockyard partition plate 17, and supplies pyrolysis gas of organic waste to the gas-liquid separator 30.

  The gas-liquid separator 30 is a cylindrical facility that gas-liquid separates the pyrolysis gas discharged from the pyrolysis gas outlet 26, and has a cone-shaped stop plate 31 that directly receives a flow of pyrolysis gas. . The thermal decomposition gas is separated into a gas component and a liquid / particulate component according to the specific gravity by the stopper plate 31. The separation gas discharge port 32 is provided at the top of the gas-liquid separator 30 and sends the separation gas from which the liquid and particulate components have been removed from the pyrolysis gas to the moisture spray tower 50a. In the gas-liquid separator bottom 33, liquid and fine particle components separated by specific gravity from the pyrolysis gas accumulate. The separation liquid discharge port 34 is provided at the bottom of the gas-liquid separator 30, and is connected to a separation liquid conduit 40 that sends liquid and particulate components separated from the pyrolysis gas by specific gravity to the liquid storage tank 60. Yes. The liquid is considered to be a mixture of condensed hydrocarbon oil and moisture, and includes a particulate component such as dust.

  The water spray towers 50a and 50b spray gas-treated water onto the separated gas separated by the gas-liquid separator 30. Here, the water spray towers having substantially the same shape are provided in two series in series. It is shown. In addition, it is good also as a structure which carries out the washing | cleaning of separation gas reliably by providing three or more series of water spray towers in series, and may add in parallel for the processing capacity according to the amount of separation gas. In the moisture spray towers 50a and 50b, gas treatment water is sprayed in the tower, and the internal temperature is 100 ° C., which is the vapor temperature, or lower. Therefore, a corrosion resistant plastic material such as vinyl chloride resin, glass fiber reinforced plastic, or dicyclopentadiene resin can be used as the structural material. When a corrosion-resistant plastic material is used, even if the separation gas contains a corrosive gas such as hydrogen chloride or sulfurous acid gas, it does not corrode and has high durability.

  First, in the upstream water spray tower 50a, the separation gas introduction path 51a has one end connected to the separation gas discharge port 32 and the other end opened to the upper side 53a side of the tower, and is supplied from the gas-liquid separator 30. The separated gas is introduced into the moisture spray tower 50a. The gas-treated water spray tower 52a has one end connected to the gas-treated water supply pipe 73 and the other end opened to the upper side 53a in the tower, and has a spray port for spraying the gas-treated water onto the separated gas. The spray port of the gas-treated water spray tower 52a sprays the gas-treated water in the form of a mist at the upper part 53a and the lower part 55a in the tower, efficiently performs gas-liquid exchange with the separated gas, and is included in the separated gas. The water-soluble component is dissolved in the gas-treated water. One end of the column outside discharge pipe 54a is connected to the column lower part 55a, and the other end is connected to the downstream separation gas introduction path 51b. The separated gas that has been gas-liquid exchanged with the gas treated water is sent to the downstream separated gas introduction path 51b via the out-to-column discharge pipe 54a. The gas treated water that has been gas-liquid exchanged with the separation gas is stored in the liquid storage tank 60 via the gas treated water discharge path 56a, the gas treated water conduit 41, and the like.

  In the downstream water spray tower 50b, the gas treated water spray tower 52b, the tower upper part 53b, the tower lower part 55b, and the gas treated water discharge path 56b are respectively the gas treated water spray tower 52a, the tower upper part 53a, and the tower lower part. 55a has the same structure and function as the gas treated water discharge passage 56a. The separation gas introduction path 51b has one end connected to the outer column discharge pipe 54a and the other end opened at the upper portion 53a in the tower, and guides the separation gas sent from the upstream water spray tower 50a to the inside of the water spray tower 50b. . One end of the tower discharge pipe 54 b is connected to the tower lower part 55 b, and the other end is connected to the cleaning gas circulation vertical pipe 82.

  The liquid storage tank 60 stores the separated liquid separated by the gas-liquid separator 30 and the gas treated water sprayed by the moisture spray towers 50a and 50b. The separation liquid line 40 and the gas treatment water line 41 are used to transport the separation liquid and the gas treatment water to the liquid storage tank 60. That is, the separation liquid conduit 40 is connected to the separation liquid outlet 34 and transports the separation liquid separated by the gas-liquid separator 30, and is connected to the gas processing water conduit 41. The separation liquid pipe 40 is further connected to the gas treated water discharge paths 56a and 56b inside the casing of the gas cleaning device 2, and transports the gas treated water sprayed by the moisture spray towers 50a and 50b. The gas processing water pipe 41 is a vertical pipe that connects the separation liquid pipe 40 and the liquid storage tank 60. The separation liquid conduit 40 is rarely used in a full water state, and usually has a structure in which the separation gas passes above the separation liquid or gas treated water.

  In the liquid storage tank 60, the liquid is separated into a heavy specific gravity liquid layer 61 mainly composed of water having a high specific gravity and a light specific gravity liquid layer 62 mainly composed of various hydrocarbon oils. The upper part of the liquid storage tank 60 is covered with a lid portion 64, and a gas retention chamber 63 is formed between the light specific gravity liquid layer 62 and the lid portion 64. In the gas retention chamber 63, the cleaned gas sent from the gas processing water pipe 41 to the heavy specific gravity liquid layer 61 is retained, and the other end of the cleaning gas circulation vertical pipe 81 is connected. The hydrocarbon oil discharge pipe 65 sends hydrocarbon oil having a light specific gravity of the light specific gravity liquid layer 62 to the waste oil tank 66. Since the mixed liquid of the separation liquid and the gas treated water stored in the liquid storage tank 60 contains moisture and hydrocarbon oil, the hydrocarbon oil is separated and stored in the waste oil tank 66.

  The liquid storage tank 60 is provided with a bubble generating device (67, 68), which promotes separation by specific gravity by performing a bubbling process in which bubbles are blown into the mixed liquid and gas-treated water mixed liquid. ing. That is, the bubble generating device has a blower pump 67 for blowing air and a bubbling pipe 68 having an outlet at the bottom of the liquid storage tank 60. The air sucked by the blower pump 67 is ejected from the ejection port by the bubbling pipe 68 and promotes the separation by specific gravity with respect to the mixed liquid of the separation liquid and the gas treated water.

  A water supply system 70 serving as a liquid circulation unit supplies water in the heavy specific gravity liquid layer 61 stored in the liquid storage tank 60 to the water spray towers 50a and 50b as gas treated water. Pipes 72 and 73 are provided. Of the liquid circulation section, the recovery pipes from the water spray towers 50a and 50b are a separation liquid pipe 40 and a gas treatment water pipe 41. The line pump 71 has a liquid suction port 74 at a position relatively close to the bottom of the liquid storage tank 60 so that moisture having a high specific gravity out of the liquid stored in the liquid storage tank 60 can be used as gas treated water. ing. In the liquid suction port 74, an appropriate filter is installed so that the dust and solids precipitated in the liquid storage tank 60 are not sucked.

  The cleaning gas circulation system 80 returns the cleaned gas (unreacted gas) sprayed with the gas treated water in the moisture spray towers 50a and 50b to the low-temperature pyrolysis apparatus 10, and includes a cleaning gas circulation vertical pipe 81, 82, a cleaning gas circulation horizontal pipe 83, and a cleaning gas circulation pipe 84. The cleaning gas circulation horizontal pipe 83 includes a cleaning gas circulation vertical pipe 82 provided in the vicinity of the moisture spray tower 50b located at the most downstream stage, and a cleaning gas circulation pipe 84 provided in the vicinity of the low temperature pyrolysis apparatus 10. It is a pipeline that connects the two, and is generally in the horizontal direction. The cleaning gas circulation horizontal pipe 83 can be appropriately arranged according to the installation state of the low-temperature pyrolysis device 10 and the gas cleaning device casing 2. The cleaning gas circulation vertical pipe 81 has one end connected to the gas retention chamber 63 and the other end connected to the end of the cleaning gas circulation vertical pipe 82. The outside discharge pipe 54b is connected to the connection part of the cleaning gas circulation vertical pipes 81 and 82.

  The filter 86 is attached to the cleaning gas circulation horizontal pipe 83, removes dust contained in the cleaned gas (unreacted gas) flowing through the cleaning gas circulation system 80, and the cleaning gas circulation system 80 is soaked and blocked. To prevent the situation. The blower 87 is a blower attached to the cleaning gas circulation horizontal pipe 83 and is necessary for the cleaned gas (unreacted gas) to flow from the cleaning gas circulation system 80 to the vicinity of the gas supply port 25 of the cleaning gas circulation pipe 84. Produces a good airflow. The mist trap 88 is attached to the cleaning gas circulation horizontal pipe 83, removes moisture contained in the cleaned gas (unreacted gas) flowing through the cleaning gas circulation system 80, and removes moisture in the cleaning gas circulation system 80. Prevents condensation. The filter 86, the blower 87, and the mist trap 88 may be attached to the cleaning gas circulation vertical pipe 82 instead of the cleaning gas circulation horizontal pipe 83.

  The permanent magnet unit 85 is installed in the ventilation passage, and the vicinity of the gas supply port 25 of the cleaning gas circulation pipe 84 is used as the ventilation passage. The permanent magnet unit 85 has at least a pair of permanent magnets arranged so as to face each other across the ventilation passage. It is empirically known that when the permanent magnet unit 85 is mounted, the amount of the cleaned gas suction from the gas supply port 25 increases by about 20 to 50%. The permanent magnet unit 75 is mounted on the gas-treated water supply pipe 72, and the pipe resistance of the gas-treated water supply pipe 72 is reduced by the mounting, so that the liquid circulation in the moisture spray towers 50a and 50b is efficient. Can be done.

  The strength of the magnetic field of the permanent magnet units 75 and 85 is a value normally used as a permanent magnet such as a ferrite magnet, a samarium cobalt magnet, or a neodymium magnet, and ranges from 0.1 Tesla to several Tesla, for example. The magnetization direction of the permanent magnet units 75 and 85 is preferably such that one of the N pole or the S pole faces each other with the ventilation passage or the water supply pipe 72 interposed therebetween. A north pole and a south pole may be magnetized along. An electromagnet or a superconducting magnet may be used in combination with the permanent magnet units 75 and 85 in order to increase the magnetic force.

  The organic dry porous material container 91 accommodates the organic dry porous material 92 as a thermal decomposition temperature maintaining material, and for example, a transport box that can be freely opened and closed by a cloth bag or a floor board is used. As the organic dry porous material 92, grain husks such as large sawdust, rice husk, buckwheat husk, and wheat husk may be used. The hanging strap 93 is used to transport the organic dry porous material container 91 from the vicinity of the low-temperature pyrolysis and volume reducing device to the charging port 11.

  The crane rail 94 is a horizontal member of a mechanical device intended to lift a load with power and transport the load horizontally, and defines a moving range. The trolley 95 travels along the crane rail 94. The crane rope 96 is used to move the organic dry porous material container 91 to a destination by suspending a hanging string 93 by a hook 97 provided at the tip. The crane can perform three operations: hoisting (direction of arrow V in the figure), traversing, and traveling (direction of arrow H in the figure). The crane may be self-propelled like a crane car, or may be fixed to the building like an overhead crane.

  The seed-fire holding material container 98 contains the seed-fire holding material 99. For example, a highly heat-resistant wire mesh bag or a metal box for transportation that can be opened and closed is used. As the seed fire holding material 99, it is preferable to use at least one kind of charcoal, molded charcoal, oga charcoal, bamboo charcoal, activated carbon, mangrove charcoal, and coconut charcoal charcoal in the seed fire state. For example, in the case of charcoal, the seed-fire holding material 99 is used after burning and igniting the charcoal. There are several methods for igniting charcoal, such as using a burner, using charcoal that has been ignited, and using a charcoal starter. By igniting the charcoal, the seed-fire holding material 99 becomes an autonomous pyrolysis state having a temperature equal to or higher than the pyrolysis temperature of the low-temperature pyrolysis volume reduction device, and enters the pyrolysis chamber 19 filled with the pyrolysis temperature holding material. It becomes a seed fire that forms the necessary fire bed when the low-temperature pyrolysis volume reduction device is started.

The operation of the radioactive organic waste volume reducing device configured as described above will be described. FIG. 2 and FIG. 3 are diagrams for explaining the start of operation of the radioactive organic waste volume reducing device of the present invention, each of which has been charged with an organic dry porous material and with a seed fire holding material. Indicates the state.
Here, based on the flowchart of FIG. 4, in the radioactive organic waste volume reducing device of the present invention, the operation process at the time of start-up and when stable will be described. First, an organic dry porous material as a thermal decomposition temperature maintaining material is charged into the stock yard 14 of the low temperature thermal decomposition apparatus 10 (S100). Since it is at the time of start-up, no pyrolysis gas is generated from the pyrolysis chamber 19, and the first layer open / close lid 15 may be opened. Moreover, although the heat insulating material 20 is spread | laid on the firebed holding | maintenance part 18, since it is at the time of starting, it is normal temperature and has not reached low temperature pyrolysis temperature. Next, when the stockyard partition plate 17 is opened (S102), the organic dry porous material 92 falls into the thermal decomposition chamber 19 (S104). Therefore, as shown in FIG. 2, the organic dry porous material 92 is sufficiently stored in the pyrolysis chamber 19 (S106), and the organic dry porous material so that the surface on the stock yard 14 side is flat. The material 92 is moved. In this case, the organic dry porous material 92 is made high enough not to block the pyrolysis gas outlet 26.

  Next, the stockyard partition plate 17 is closed in preparation for putting in the seed fire holding material (S108). And the seed-fire holding | maintenance material 99 is thrown into the stock yard 14 of the low-temperature pyrolysis apparatus 10 (S110). Next, when the stockyard partition plate 17 is opened (S112), the seed fire holding material 99 falls into the thermal decomposition chamber 19 and covers the organic dry porous material 92 (S114). Here, the seed fire holding material 99 is prevented from gathering near the inlet 11, and the seed fire holding material 99 covers the organic dry porous material 92 with a uniform thickness as shown in FIG. The falling state of the seed fire holding material 99 is adjusted in small portions so that

  Next, the stockyard partition plate 17 is closed (S116) so that the pyrolysis gas generated from the seed fire holding material 99 and the organic dry porous material 92 does not leak to the surroundings. In the pyrolysis chamber 19, the pyrolysis of the organic dry porous material 92 is stably maintained by the seed fire holding material 99 (S118). Then, the entire organic dry porous material 92 is in a pyrolysis state, a fire bed is formed, and the entire heat retaining material 20 reaches the low temperature pyrolysis temperature. When the state in which the entire heat-retaining material 20 reaches the low-temperature pyrolysis temperature is maintained for a predetermined period, for example, for 2 days to 1 month, the organic waste is reduced in volume and the organic waste is reduced to the organic waste. The amount of radioactive material contained decreases (S119).

In addition, a firebed is formed, and the entire heat-retaining material 20 reaches the low-temperature pyrolysis temperature, and the organic dry porous material 92 is gradually reduced in volume by low-temperature pyrolysis, so that the pyrolysis chamber 19 is reduced. A void is formed in order to put the organic waste into. At this stage, the organic waste subject to low temperature pyrolysis is supplied to the stockyard 14 (S120). Then, the organic waste is warmed and adjusted to an appropriate moisture content, for example, 5% to 25%, and the stockyard partition plate 17 is opened (S122). The appropriate moisture content varies depending on the calories of the organic waste, but the lower limit value of the moisture content is determined so as to prevent excessively high temperature from the low temperature pyrolysis temperature. The upper limit of the moisture content is determined so that the low temperature pyrolysis temperature can be maintained even if energy is consumed to evaporate the moisture.
Then, the organic waste subject to low-temperature pyrolysis falls from the stock yard 14 to the pyrolysis chamber 19 (S124). The dropped organic waste may be diffused to a uniform thickness on the fire bed. Then, the stockyard partition plate 17 is closed (S126) so that pyrolysis gas generated from the organic waste does not leak to the surroundings.

  The organic waste in the pyrolysis chamber 19 gradually decreases as the low-temperature pyrolysis and volume reduction progresses. For example, when about 3 to 21 days have passed, most of the waste remains and is used as a general incineration index. The volume is greatly reduced from 1 / 100th to 1 / 1,000th of 1/10. Therefore, it is determined whether there is an organic waste subject to low-temperature pyrolysis (S128). If Yes, the process returns to S120, and the organic waste is supplied to the stock yard 14. If it is No, a low-temperature pyrolysis volume reduction process will be complete | finished. In this case, if the fire bed does not disappear, the operation can be resumed from S120, but if the fire bed disappears, the process returns to S100 and starts from the beginning.

Since general waste and industrial waste contain carbon compounds such as wood, paper, plastic, rubber, etc., oxidation energy is generated along with oxidation by oxygen slightly contained in the cleaned gas. Further, it is considered that the cleaned gas is activated by the magnetic action when passing through the magnetic field generated by the permanent magnet unit 85. By this magnetic activation treatment, thermal decomposition of general waste and industrial waste in the low-temperature pyrolysis apparatus is promoted, and for example, the thermal decomposition rate is accelerated by several tens of percent. Regarding the decay of radioactive cesium, there is a possibility that it decays at a rate of 1000 to 10,000 times compared to the natural half-life.
Since the volume reduction device for radioactive organic waste according to the present invention is a closed system for gas and a closed system for liquid, a measurement result that radioactive cesium has disappeared for some reason is obtained. Yes. The present inventors consider that what accelerates the half-life of radioactive cesium from general physics common sense is due to the joint catalytic action of zeolite ore and low-temperature pyrolysis temperature, and the magnetic field of the permanent magnet unit 85. The possibility that is acting indirectly cannot be denied.

  In the low-temperature pyrolysis apparatus 10, the raw material is combusted at a low temperature of 200 ° C. to 300 ° C. at each stage as compared with combustion, and at the same time, the pyrolysis product and the cleaned gas are reacted to produce a single oxidation. Pyrolytic gas containing carbon and water vapor are generated. The generated pyrolysis gas and water vapor are sent to a water spray tower 50 as the gas cleaning device casing 2 to perform a showering process (spraying the gas-treated water on the separation gas). And in the liquid storage tank 60 as a specific gravity separator, the gas processing water sprayed with the moisture spray tower 50 is stored. In the specific gravity separator, gas treated water is subjected to bubbling treatment. The separation gas generated in the liquid storage tank 60 is returned to the low-temperature pyrolysis apparatus 10 and is subjected to magnetization processing by the permanent magnet unit 85 at that time. The cleaned gas sprayed with the gas treated water in the moisture spray towers 50a and 50b includes an unreacted gas containing unreacted components that have not been thermally decomposed by the low-temperature pyrolysis apparatus 10, and the cleaning gas circulation system 80 Returned to the low-temperature pyrolysis apparatus 10.

  The liquid separated by specific gravity in the liquid storage tank 60 is separated into oil and moisture. The water is returned to the water spray tower 50 as gas-treated water, but is magnetized by the permanent magnet unit 75 in the middle of the piping. It is thought that the magnetization process with respect to gas treated water also reduces the fluid resistance in piping which comprises a liquid circulation part. The water in the storage tank 60 has a high BOD (Biochemical Oxygen Demand) and requires wastewater treatment. In wastewater treatment, for example, activated sludge is used. The separated activated sludge can be put into the stock yard 14 as an organic waste and thermally decomposed, and the decay of the radioactive cesium is also promoted.

Next, a description will be given of the results of tests conducted by the present device in the sorting area of the Hirono Town Disaster Waste Temporary Storage Area located in the Kitashita area of Hirono Town, Futaba County, Fukushima Prefecture. The duration of the test is as follows. Here, the period of a test means the period which processed the organic waste containing a very low level radioactive cesium with the apparatus of this invention.
Period of Exam 1: March 18 to April 4, 2012 Period of Exam 2: May 6 to May 21, 2012 Period of Exam 3: July 9 to August 3, 2012 Day

また、本発明の装置には、表１に示すように、ストックヤード１４の廃棄物供給容量が小容量の０．７５ｍ^３と設備と、中容量の１０ｍ^３の設備の二種類がある。小容量設備は、回収槽としての廃油タンク６６の容量が１００リットル、循環水槽としての貯液タンク６０の容量が１００リットル、ゼオライト鉱石は３００ｋｇを用いている。中容量設備は、回収槽の容量が２００リットル、循環水槽の容量が２００リットル、ゼオライト鉱石は３０００ｋｇを用いている。小容量設備は、試験１の期間と試験２の期間について使用し、中容量設備は、試験３の期間について使用した。

In addition, as shown in Table 1, the apparatus of the present invention has two types of equipment, that is, a waste supply capacity of the stock yard 14 of 0.75 m ³ with a small capacity and an equipment with a medium capacity of 10 m ³ . In the small capacity facility, the capacity of the waste oil tank 66 as a recovery tank is 100 liters, the capacity of the liquid storage tank 60 as a circulating water tank is 100 liters, and the zeolite ore is 300 kg. The medium capacity facility uses a recovery tank capacity of 200 liters, a circulating water tank capacity of 200 liters, and a zeolite ore of 3000 kg. Small capacity equipment was used for the period of test 1 and test 2 and medium capacity equipment was used for the period of test 3.

有機性廃棄物をストックヤード１４に投入した重量は、試験１で１３３．６ｋｇ、試験２で１２９．８ｋｇ、試験３で３５３０ｋｇであり、稼働日数は其々１８日、１５日、２５日間である（表２参照）。また、試験の最終日に計量した残さ重量に関しては、試験１で０．０１ｋｇ、試験２で０．６ｋｇ、試験３で６ｋｇであり、減容化率として千分の１乃至千分の５程度が得られている（表３参照）。

The weight of the organic waste charged into the stockyard 14 is 133.6 kg in Test 1, 129.8 kg in Test 2, and 3530 kg in Test 3, and the working days are 18 days, 15 days, and 25 days, respectively. (See Table 2). The remaining weight measured on the last day of the test is 0.01 kg in Test 1, 0.6 kg in Test 2, and 6 kg in Test 3, and the volume reduction rate is about 1 / 1,000 to 5/1000. Is obtained (see Table 3).

By the way, the extremely low level radioactive cesium contained in the organic waste is transferred to cracked oil, circulating water and circulating gas, and is adsorbed by the zeolite ore, and the rest should be contained in the residue. The space γ dose rate on the surface of the zeolite ore after completion of the test is 0.549 μSV / h, which is about the background concentration of the place where the test was performed. The space γ dose rate is measured using an environmental radiation monitor (PA-1000, solid scintillator CsI (TI) detector) manufactured by Horiba.
In Test 1, the concentration of radioactive material in the residue and circulating water is measured. The concentration of the residual is 2930 Bq / kg, but since the amount of the residue is about 0.01 kg, it is considered that no concentration of the radioactive substance occurs in the residue (see Table 4). Circulating water is not detected, but the detection limit is 10 Bq / kg (see Table 5). In Table 5, the columns marked with “-” for cracked oil, furnace gas, etc. indicate that they have not been measured.

そこで、放射性物質の全体の物質バランスを検討すると、例えば試験１で投入された全量は約５３万Ｂｑであるのに対して、残さに含まれるのは２９Ｂｑである（表６参照）。従って、分解油、循環水、炉内ガス、ゼオライト鉱石に移行した量と、何らかの原因で減衰した量が５３万Ｂｑとなる。残さ基準での放射性物質の減少量は９９．９９％となる。

表７は、投入廃棄物の量と放射能量の関係を示したものである。試験１で投入された廃棄物全量は１３３．６ｋｇであり、投入放射能の全量は約５３万Ｂｑであるから、平均濃度は約４０００Ｂｑ／ｋｇとなる。試験２、３についても平均濃度は約４０００Ｂｑ／ｋｇと約１万Ｂｑ／ｋｇである。

Therefore, when the total substance balance of radioactive substances is examined, for example, the total amount introduced in Test 1 is about 530,000 Bq, whereas the remaining is 29 Bq (see Table 6). Therefore, the amount transferred to cracked oil, circulating water, furnace gas, and zeolite ore and the amount attenuated for some reason are 530,000 Bq. The reduction amount of radioactive material on the basis of the residue is 99.99%.

Table 7 shows the relationship between the amount of input waste and the amount of radioactivity. Since the total amount of waste input in Test 1 is 133.6 kg and the total amount of input radioactivity is about 530,000 Bq, the average concentration is about 4000 Bq / kg. For tests 2 and 3, the average concentrations are about 4000 Bq / kg and about 10,000 Bq / kg.

放射性セシウムの半減期が３０年のままであれば、投入廃棄物の熱分解に伴って放射性セシウムが濃縮され、低温熱分解装置１０内の放射性セシウムの全量は実質的に不変と考えられる。そこで、熱分解装置稼働時の周辺空間γ線量率を測定した。図５は、熱分解装置稼働時の周辺空間γ線量率の分布状態を説明する図である。表８で示すように、分解油タンクとしての廃油タンク６６と、循環水タンクとしての貯液タンク６０の周辺が、低温熱分解装置の近傍地点よりも低い値となっている。また、周辺空間γ線量率は熱分解装置から離れるほど高くなっている。

If the half-life of radioactive cesium remains 30 years, the radioactive cesium is concentrated with the pyrolysis of the input waste, and the total amount of radioactive cesium in the low-temperature pyrolysis apparatus 10 is considered to be substantially unchanged. Therefore, the peripheral space γ dose rate during operation of the thermal decomposition apparatus was measured. FIG. 5 is a diagram for explaining the distribution state of the peripheral space γ dose rate during operation of the thermal decomposition apparatus. As shown in Table 8, the surroundings of the waste oil tank 66 as the cracked oil tank and the liquid storage tank 60 as the circulating water tank are lower than the vicinity of the low temperature pyrolysis apparatus. Further, the peripheral space γ dose rate increases as the distance from the thermal decomposition apparatus increases.

広野町災害廃棄物仮置き場は、災害廃棄物の分別作業を行っている場所で、平成２４年１月〜３月の平均空間γ線量率は表９のようになっている。仮置き場に集積されている災害廃棄物には放射性物質が含まれており、その放射能濃度には高低があるが、一時的に放射性物質が集積されているストックヤード周辺が仮置き場内の平均値よりも高くなっている。しかし、熱分解装置稼働時の周辺空間γ線量率は、熱分解装置の近傍が仮置き場内の平均空間γ線量率よりも低くなっており、熱分解装置の稼働には放射能濃度を低める作用があることが実測された。
特別管理が必要な廃棄物を含めて、一般的な産業廃棄物を適正処理するには、減容化を行うことで最終処分量を少なくすることが適切である。減容化処理としては、焼却処理が一般的である。しかし、廃棄物に放射性物質が含まれる場合には、焼却の過程で放射性物質の消滅は起きず、燃え殻や煤塵に放射性物質が濃縮されて含まれる。そこで、放射性廃棄物の減容処理によって算出される中間処理廃棄物の処理が難しくなっている。

The Hirono Town Disaster Waste Temporary Storage Site is where disaster waste is sorted, and the average space gamma dose rate from January to March 2012 is as shown in Table 9. The disaster waste accumulated in the temporary storage area contains radioactive materials, and the radioactivity concentration is high or low, but the area around the stockyard where the radioactive materials are temporarily stored is the average in the temporary storage area. It is higher than the value. However, the ambient space γ dose rate during operation of the pyrolysis device is lower than the average space γ dose rate in the temporary storage area in the vicinity of the pyrolysis device, and the action of reducing the radioactivity concentration in the operation of the pyrolysis device It was actually measured.
In order to properly process general industrial waste, including waste that requires special management, it is appropriate to reduce the volume of final disposal by reducing the volume. An incineration process is common as a volume reduction process. However, when radioactive materials are included in the waste, the radioactive materials do not disappear during the incineration process, and the radioactive materials are concentrated and contained in the burning husks and dust. Therefore, it is difficult to process intermediate processing waste calculated by radioactive waste volume reduction processing.

次に、熱分解装置で算出された残さの性状を説明する。表１０に示すように、残さは、ケイ素、マグネシウム、カリウム、鉄、アルミニウムの五成分で４１重量％を含んでいる。この測定ではカルシウムを測定していないが、ゼオライト鉱石の成分であるため、相当量含まれていると考えられる。炭素分や熱杓減量の測定はないが、残さには炭素分はあまり含まれていないと考えられる。減容化の過程で、有機性廃棄物の炭素分は、分解されて分解油となると考えられる。

残さからの溶出試験結果は、表１１に示されている。塩化物イオンが０．５２％と多く溶出している。有害物質とされる重金属などに関しては、カドミウム以外検出されていない。

Next, the properties of the residue calculated by the thermal decomposition apparatus will be described. As shown in Table 10, the residue contains 41% by weight of five components of silicon, magnesium, potassium, iron, and aluminum. Although calcium is not measured in this measurement, it is considered to be contained in a considerable amount because it is a component of zeolite ore. There is no measurement of carbon or heat loss, but it is thought that the residue does not contain much carbon. In the process of volume reduction, the carbon content of organic waste is considered to be decomposed into cracked oil.

The dissolution test results from the residue are shown in Table 11. Chloride ions are eluted as much as 0.52%. No heavy metals other than cadmium have been detected as harmful metals.

有機性廃棄物が熱分解された後、ガス状となり、熱分解室１９から気液分離器３０に送られる。その後、分解液体は気液分離器３０で油分を含む状態で回収される。また、分解ガスは水分噴霧塔５０へて貯液タンク６０とで回収され、油分を含む液体状態で回収される。
そこで、貯液タンク６０や給水系統７０に含まれる循環水の性状を測定した。循環水の性状測定結果は、表１２に示すようになっている。水分は９７．８％であり、水分を除く成分としては、炭素が６８．２％となっている。油分は０．４９％が循環水に含まれており、熱灼減量が９５．７％となっている。

After the organic waste is thermally decomposed, it becomes gaseous and is sent from the thermal decomposition chamber 19 to the gas-liquid separator 30. Thereafter, the cracked liquid is recovered by the gas-liquid separator 30 in a state containing oil. The cracked gas is collected in the water spray tower 50 and the liquid storage tank 60, and is recovered in a liquid state containing oil.
Therefore, the properties of the circulating water contained in the liquid storage tank 60 and the water supply system 70 were measured. The results of measuring the properties of the circulating water are shown in Table 12. The moisture is 97.8%, and the component excluding moisture is 68.2% carbon. The oil content is 0.49% in the circulating water, and the heat loss is 95.7%.

表１３は循環水の溶解成分の測定結果である。循環水の溶解成分には、シアン化合物やフッ素化合物、鉛や極少量のカドミウムが含まれているが、その他に重金属類は検出されなかった。放射性セシウムは崩壊によりバリウムになるが、両者共に検出下限値以下であった。

Table 13 shows measurement results of dissolved components of circulating water. The dissolved components of the circulating water contained cyanide, fluorine compounds, lead and a very small amount of cadmium, but no other heavy metals were detected. Although radioactive cesium became barium by decay, both were below the lower limit of detection.

有機性廃棄物が熱分解された後に生成する液状物質（炭化油）については、試験３で測定しており、表１４に示す結果が得られた。ここで、分解油は貯液タンク６０の軽比重液体層６２のもので、ｎ−ヘキサン抽出物質は１．３ｇ／ｌとなっている。回収油分は廃油タンク６６に蓄えられた廃油分で、ｎ−ヘキサン抽出物質は１６ｇ／ｌとなっている。循環水は貯液タンク６０の重比重液体層６１のもので、ｎ−ヘキサン抽出物質は４ｍｇ／ｌとなっている。洗浄水は分離液管路４０とガス処理水管路４１のもので、ｎ−ヘキサン抽出物質は２．２ｇ／ｌとなっている。

The liquid substance (carbonized oil) produced after the organic waste was thermally decomposed was measured in Test 3, and the results shown in Table 14 were obtained. Here, the cracked oil is in the light specific gravity liquid layer 62 of the liquid storage tank 60, and the n-hexane extract substance is 1.3 g / l. The recovered oil is the waste oil stored in the waste oil tank 66, and the n-hexane extract substance is 16 g / l. The circulating water is in the heavy specific gravity liquid layer 61 of the liquid storage tank 60, and the n-hexane extract substance is 4 mg / l. The washing water is from the separation liquid line 40 and the gas treatment water line 41, and the amount of n-hexane extract is 2.2 g / l.

In the low-temperature pyrolysis apparatus of the present invention, it is considered that radioactive cesium contained in organic waste has decayed in 3 to 4 orders of magnitude shorter than the socially accepted half-life.
Then, organic waste was accommodated in a ceramic container or a steel container, covered and processed in the low-temperature pyrolysis apparatus of the present invention, and the concentration of radioactive cesium was measured. The duration of the test is 8 days for stainless steel containers and 14 days for ceramic containers. Since the thermal decomposition temperature is 200 ° C. to 300 ° C., regarding moisture and humus components among soil components, evaporation of moisture and volatilization of carbide volatile components are assumed. These moisture and volatile components are thought to have moved into the pyrolysis device from gaps and vents in the lids of ceramic and steel containers. Of the soil components, radioactive cesium is adsorbed to the clay component of the soil and is unlikely to have volatilized.

Table 15 shows the measured values of radioactive cesium when organic waste is stored in a ceramic container or a steel container, covered and processed in the low-temperature pyrolysis apparatus of the present invention. The soil was sieved with a sieve having a mesh size of about 100 μm and fine particles were used. The sieved soil before the test was 680 Bq / kg for cesium 134 and 1040 Bq / kg for cesium 137. In the ceramic container, radioactive cesium was approximately halved after the treatment, cesium 134 was 329 Bq / kg, and cesium 137 was 485 Bq / kg. Even in the stainless steel container, radioactive cesium was almost halved after the treatment, cesium 134 was 336 Bq / kg, and cesium 137 was 485 Bq / kg.

表１６には、表１５の試料における土壌の熱灼減量を示している。熱灼減量は一般廃棄物を焼却処理した後に生じる焼却灰に含まれる可燃性分の含有割合とされている。なお、熱灼減量は一般廃棄物処理事業に対する指導に伴う留意事項について（昭和５２年１１月４日環整９５号）に準拠するもので、電気炉内で６００℃±２５℃で三時間強熱した後、デシケータ内で放冷後、試料を精秤した数値である。熱灼減量は土壌に含まれる有機成分と考えられるが、試験前の土壌では６．１％であるのに対して、陶磁器容器とスチール容器については、試験後はそれぞれ０．８％と０．９％と減少している。従って、土壌に含まれる有機成分は殆どが熱分解されたと見做せる。

Table 16 shows the heat loss of the soil in the samples of Table 15. The amount of heat loss is the content of combustible matter contained in the incinerated ash generated after incineration of general waste. Note that the amount of heat loss is based on the precautions accompanying the guidance for the general waste disposal business (Environment No. 95, November 4, 1977). It is a little over 3 hours at 600 ° C ± 25 ° C in an electric furnace. It is a numerical value obtained by precisely weighing the sample after heating and after cooling in a desiccator. Heat loss is considered to be an organic component contained in the soil, but it is 6.1% in the soil before the test, whereas in the ceramic container and the steel container, 0.8% and 0.00%, respectively, after the test. It has decreased to 9%. Therefore, it can be considered that most of the organic components contained in the soil are thermally decomposed.

In the above tests 1 to 3, if the half-life of radioactive cesium is not changed according to common wisdom, the concentration of radioactive cesium should be caused by residue and circulating water in a simple pyrolysis treatment. However, in any of the test results, no concentration of radioactive cesium was observed, and the radioactive cesium decreased on the contrary. Therefore, if the amount of barium produced by decay of radioactive cesium is measured, the analysis proceeds further, but the amount of barium is extremely small. According to a report from the National Institute of Health Sciences, barium is dissolved at 15 mg / l or more in the surface water of the environment, and barium generated by decay of radioactive cesium is added to the existing barium in the environment. Even if this is the case, there is a high possibility of being below the detection error.
Therefore, in the low-temperature pyrolysis apparatus of the present invention, a comparative experiment for verifying whether or not there is an influence of a single magnetic field was performed on the true reason for the significant decrease in radioactive cesium.

[Comparative example]
In the comparative experiment, we examined changes in soil radioactivity when the pyrolysis furnace is not in operation, and verified whether decay of radioactive cesium contained in organic waste is promoted only by the magnetic field of the pyrolysis furnace. It was.
The experiment place is in the Hirono-cho temporary storage place like Tests 1-3. The experiment period is 8 days from November 20, 2012 to November 28, 2012. The experimental apparatus is a gas circulation system 80 including a pyrolysis chamber 19, a gas supply port 25, and a blower 87 that form a part of the low-temperature pyrolysis apparatus of the present invention. The pyrolysis chamber 19 was used in an empty state, did not use the heat-retaining material 20, and was maintained at room temperature instead of low-temperature pyrolysis temperature.
The experimental method is to put radioactive soil (cesium sum about 1600 Bq / kg) into a clay pot equivalent to a ceramic container shown in Table 15 and a steel pot equivalent to a stainless steel container, each with an attached lid. In an empty pyrolysis chamber 19, it was stored in a substantially sealed state. Then, air magnetically processed by the permanent magnet unit 85 is sent from the gas supply port 25 to the thermal decomposition chamber 19 and kept in that state for 8 days. About 1.4 kg of each soil is sampled and measured for radioactivity. Did. The radioactivity measuring machine is AT1320A / C manufactured by ATOMTEX.
During operation, the magnetic field in the vicinity of the heat treatment chamber (in the vicinity of 1 m in height and on the indoor wall side near the indoor floor) and in the vicinity of the permanent magnet unit 85 was measured.

FIG. 6 is a diagram for explaining a magnetic field distribution state in a non-operating state of the thermal decomposition apparatus.
The magnetic field measuring instrument is Teslameter TM-701 manufactured by Kanetech Co., Ltd., the resolution is 0.1 mT when the measuring range of the magnetic field measuring instrument is 200 mT, and the resolution is 200 mT to 3 T when the measuring range is 200 mT. 1 mT. The environmental magnetic field measured in Ono-cho, Tamura-gun, Fukushima Prefecture was about 0.3 mT. Although the environmental magnetic field in Japan is about 0.05 mT, it was considered as an allowable range depending on calibration.
In the vicinity of the permanent magnet unit 85, a magnetic field measurement value of about 139 to 146 mT was obtained. On the other hand, it was 0.32 mT inside the pyrolysis chamber 19, and about 0.3 mT at a position 1 m away from the wall surface around the outside of the pyrolysis chamber 19, a value close to the environmental magnetic field.

The results of the radioactivity experiment are as shown in Table 17. Before and after the comparative experiment, the soil radioactivity was almost unchanged and no decrease in radioactivity was observed.
From the results of the above comparative experiments, it has been found that radiation is not reduced simply by feeding air that has been subjected to magnetic treatment without heat treatment in an environment where the heat treatment chamber is at an environmental magnetic field.

  Thus, in the low-temperature pyrolysis apparatus of the present invention, the reason for the significant decrease in radioactive cesium is that the decay rate of radioactive cesium increases dramatically due to the catalytic action of zeolite ore and the low-temperature pyrolysis temperature. The result is considered. In addition, the circulating gas magnetically processed by the permanent magnet unit and the wall material of the pyrolysis chamber have ferromagnetism even at the low temperature pyrolysis temperature, which helps to greatly reduce radioactive cesium due to the additional effect of the magnetic field. There is also a possibility.

  In the above-described embodiment of the present invention, the present invention has been described using specific examples. However, the present invention is not limited to the above-described embodiment, and is obvious to those skilled in the art. The embodiment designed within the range is also included. For example, a permanent magnet unit has a limited magnetomotive force with a permanent magnet alone, and is about 0.5 Tesla even with a samarium cobalt magnet, a neodymium magnet, etc., but 10 Tesla, 20 Tesla, 50 Tesla using an electromagnet or a superconducting magnet. High magnetic field can be realized. Moreover, although the case where a ferromagnetic structural material such as iron is used for the wall surface material of the pyrolysis chamber 19 and the partition plate and the lattice member of the firebed holding unit 18 is shown, the ferromagnetism is maintained at a low temperature pyrolysis temperature. If it is a member, you may use members, such as cobalt steel and nickel steel.

The radioactive organic waste volume reducing device of the present invention and the method of using the same are used in a large amount of soil when a wide range of forests and organic waste are contaminated with radioactive materials such as radioactive cesium due to a nuclear disaster. It is suitable for performing volume reduction treatment for rubble and rubble.
Further, the volume reduction device for radioactive organic waste and the method of using the same of the present invention are suitable for volume reduction treatment of low-level radioactive contaminants generated accompanying the operation of nuclear power plants. Even when stored in a tunnel isolated from the natural environment, the volume of radioactive contaminants is reduced and the processing cost is greatly reduced.

1 Volume reduction device for radioactive organic waste 2 Gas cleaning device 10 Pyrolysis container (low temperature pyrolysis device)
11 Charging Port 18 Firebed Holding Unit 19 Pyrolysis Chamber 20 Heat Insulating Material (Zeolite Ore)
23 Residue outlet 24 Gas ventilation part (high permeability member)
25 Gas supply port 26 Pyrolysis gas outlet 30 Gas-liquid separator 50a, 50b Moisture spray tower 60 Storage tank 66 Waste oil tank 70 Water supply system 75, 85 Permanent magnet unit (magnetic generation means)
80 Cleaning gas circulation system 92 Pyrolysis temperature holding material 99

Claims (6)

Low-temperature pyrolysis having a pyrolysis chamber in which organic waste is pyrolyzed at a low-temperature pyrolysis temperature, and a fire bed holding unit for holding a fire bed for pyrolyzing the organic waste at the low-temperature pyrolysis temperature A device,
Means for supplying a pyrolysis temperature maintaining material composed of an organic dry porous material for forming the fire bed to the pyrolysis chamber;
Means for supplying the pyrolysis chamber with a seed fire holding material in an autonomous pyrolysis state having a temperature at least equal to or higher than the pyrolysis temperature;
The organic waste contains radioactive material;
The fire bed holding part is placed with a predetermined thickness of zeolite ore,
An apparatus for reducing the volume of radioactive organic waste, comprising a gas circulation system for circulating exhaust gas from the thermal decomposition chamber and supplying the exhaust gas to the thermal decomposition chamber. The pyrolysis chamber has a pyrolysis gas outlet for discharging pyrolysis gas of the organic waste that has been pyrolyzed,
The gas circulation system returns the cleaned gas obtained by cleaning the pyrolysis gas with moisture,
The apparatus for reducing the volume of radioactive organic waste according to claim 1, wherein the pyrolysis chamber has a gas supply port for sucking the cleaned gas into the pyrolysis chamber. 3. The radioactive organic waste according to claim 1, wherein the low-temperature pyrolysis temperature is approximately in a range of 200 ° C. to 300 ° C. as an organic waste temperature to be pyrolyzed in the pyrolysis chamber. Equipment for volume reduction . Furthermore, a magnetic generation means for generating a magnetic field,
A high-permeability member made of a material having ferromagnetism at the low-temperature pyrolysis temperature for guiding the magnetism generated by the magnetism generating means to the firebed holding unit;
The volume reduction device for radioactive organic waste according to any one of claims 1 to 3, characterized by comprising: A stock yard for temporarily storing the seed fire holding material to be put into the pyrolysis chamber;
A stockyard partition plate provided between the pyrolysis chamber and the stockyard;
Provided with a, the seed fire holding material stored in the stockyard is characterized by a structure that falls every small amount relative to the surface of the thermal decomposition temperature holding material contained in the pyrolysis chamber according The volume reduction device for radioactive organic waste according to any one of claims 1 to 4 . A method of using the volume reduction device for radioactive organic waste according to any one of claims 1 to 5 ,
Supplying a pyrolysis temperature maintaining material made of an organic dry porous material for forming the fire bed to the pyrolysis chamber;
Supplying the pyrolysis chamber with a seed fire holding material in an autonomous pyrolysis state having at least a temperature equal to or higher than the pyrolysis temperature;
Stably maintaining the thermal decomposition of the thermal decomposition temperature maintaining material by the seed flame holding material in the thermal decomposition chamber;
After the thermal decomposition stabilization step of the thermal decomposition temperature maintaining material, supplying organic waste containing a radioactive substance to be subjected to low temperature thermal decomposition to the thermal decomposition chamber;
Maintaining the pyrolysis temperature until the volume of radioactive waste contained in the organic waste is reduced while the volume of the organic waste is reduced;
A method of using a volume reduction device for radioactive organic waste comprising:

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