JP2018054341A - Treating device and treating method for waste matter contaminated with radioactive substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treating device and a treating method that permit recovery of waste matter contaminated with radioactive substance to recover the radioactive substance by heating, and steady manufacture of fired substance with reduced radioactive substance concentration.SOLUTION: A treating device 1 is equipped with a heating unit (rotary kiln) 7 that heats waste matter W contaminated with radioactive substance, a recovering unit (a first waste collector 10 or the like) that recovers radioactive substance volatilized by heating, a measuring unit 23 that is supplied with fired substance B2 discharged from the heating unit and measures the quantity of radioactive rays radiating from the fired substance, and a bypass route 25 via which the fired substance is discharged from the heating unit instead of supplying it to the measuring unit. It is desirable for the measuring unit to be equipped with a tank for accepting the fired substance discharged from the heating unit, a detector disposed in the tank to detect radioactive rays, and air purging means that blows into the tank air for blowing out of the tank the fired substance B2 remaining in the tank after the detection of radioactive rays.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus and method for treating waste contaminated with radioactive materials, and more particularly to an apparatus for firing the waste contaminated with radioactive materials to recover the radioactive material and effectively using the fired material. Regarding the method.

  Due to the nuclear accident caused by the earthquake disaster last year, the amount of waste contaminated with radioactive materials such as radioactive cesium has reached a huge amount in the disaster-stricken area, and the radioactive material must be recovered from a large amount of waste around the disaster-stricken area. Is required. On the other hand, since it takes a great deal of cost to recover radioactive material from a large amount of waste contaminated with radioactive material, in order to substantially reduce the cost required for such recovery, It was desirable to make effective use of waste.

  Therefore, in Patent Document 1, the waste contaminated with radioactive cesium is heated with a rotary kiln to volatilize the radioactive cesium in the waste, the gas generated by the heating is cooled, and the radioactive cesium is recovered and heated. It has been proposed that the obtained fired product is cooled with a cooler and effectively used for earthwork materials. This makes it possible to treat a large amount of waste contaminated with radioactive cesium, and to obtain a fired product that can be effectively used with a reduced concentration of radioactive cesium.

JP 2013-108782 A

  However, according to the method described in Patent Document 1, fluctuations in operating conditions due to growth or dropout of coaching in the rotary kiln, or fluctuations in physical properties such as fluidity, chemical composition, and radioactive cesium concentration of waste supplied to the rotary kiln. Therefore, there may be a case where a heating temperature and a heating time sufficient to volatilize radioactive cesium in the rotary kiln cannot be secured, and a fired product having a high radioactive cesium concentration may be discharged from the rotary kiln.

  Therefore, the present invention has been made in view of the above-described problems in the prior art, and heats waste contaminated with radioactive material to recover the radioactive material, and stabilizes the fired product having a low concentration of radioactive material. It aims to manufacture.

  To achieve the above object, the present invention provides a heating device for heating waste contaminated with radioactive materials, a recovery device for recovering radioactive materials volatilized by the heating, and a fired product discharged from the heating device. A measuring device that measures the amount of radiation supplied and emitted from the fired product, and a bypass route that discharges the fired product discharged from the heating device to the outside of the system without supplying the measuring device. To do.

  According to the present invention, the radioactive material is heated to recover the radioactive material and collect the radioactive material, and by using the bypass route, the calcined material having a high concentration of radioactive cesium is not supplied to the measuring device. The measurement accuracy of the cesium concentration can be maintained high, and a fired product having a low radioactive cesium concentration can be stably produced.

  In the waste treatment apparatus contaminated with the radioactive substance, the measurement device includes a tank that receives the fired product discharged from the heating device, a detector that is provided in the tank and detects radiation, and radiation detection. An air purging unit that blows air into the tank to discharge the fired product remaining in the tank later from the tank can be provided. As a result, the amount of radiation emitted from the empty tank can be reduced, and the measurement accuracy of the radioactive cesium concentration of the measuring apparatus can be further improved.

  The present invention also relates to a method for treating a waste contaminated with a radioactive substance, the waste contaminated with a radioactive substance is heated, and the radioactive substance volatilized by the heating is recovered and obtained by the heating. In the measurement of the amount of radiation emitted from the fired product by supplying the fired product to the measuring device, the fired product having a radioactive material concentration of the fired product obtained by heating is not supplied to the measuring device. It is characterized by being discharged outside the system.

  According to the present invention, as in the case of the above-described invention, the waste contaminated with the radioactive substance can be heated to recover the radioactive substance, and the baked product having a radioactive substance concentration of a predetermined value or more is discharged out of the system. Thus, the measurement accuracy of the radioactive cesium concentration of the measuring device can be maintained high, and a fired product having a low radioactive cesium concentration can be stably produced.

  In the method for treating waste contaminated with a radioactive substance, a fired product fired at a predetermined temperature or lower in the heating device, a fired product discharged from the heating device after being fired in the heating device, or a measuring device The calcined product having the radioactive substance concentration measured in the previous stage is not less than the predetermined value can be discharged out of the system without being supplied to the measuring device.

  As described above, according to the present invention, the waste contaminated with the radioactive substance can be heated to recover the radioactive substance, and a fired product with a low radioactive substance concentration can be stably produced.

1 is an overall configuration diagram showing an embodiment of a treatment apparatus for waste contaminated with a radioactive substance according to the present invention. It is sectional drawing of the tank in the measuring apparatus of the processing apparatus shown in FIG. 1, (a) is a figure which shows an empty tank, (b) is a figure which shows the tank which stored the baking products. In the measuring apparatus shown in FIG. 2, it is a graph which shows the relationship between the measured value of a radioactive cesium density | concentration, and the radioactive cesium density | concentration of an actual baked material for every radiation dose (background value) in the empty tank.

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings. In the following description, a case where waste contaminated with radioactive cesium is treated as an example of waste contaminated with radioactive material will be described. The radioactive cesium is cesium 134 and cesium 137, which are radioactive isotopes of cesium.

  FIG. 1 shows an embodiment of a treatment apparatus for waste contaminated with radioactive substances according to the present invention. The treatment apparatus 1 includes a storage tank 3 for storing waste W contaminated with radioactive cesium, a reaction tank A storage tank 4 for storing a calcium oxide source (hereinafter referred to as “CaO source”) as a promoter, a storage tank 5 for storing a chlorine source (hereinafter referred to as “Cl source”) as a reaction accelerator, and storage tanks 3 to 5 And a preparation device 6 for extracting and preparing the waste W, the CaO source, and the Cl source stored in the container.

  Further, the processing device 1 includes a rotary kiln 7 for firing the mixed raw material M discharged from the blending device 6, a cooling tower 8 for cooling the exhaust gas G of the rotary kiln 7, a cyclone 9 for classifying the exhaust gas G1 of the cooling tower 8, A first dust collector 10 that collects the exhaust gas G2 of the cyclone 9, a second dust collector 11 that collects the exhaust gas G3 of the first dust collector 10, a denitration device 12 that denitrates the exhaust gas G4 of the second dust collector 11, and a denitration device 12 And a chimney 13 for releasing the exhaust gas G5 to the atmosphere.

  Furthermore, the processing apparatus 1 includes a buffer tank 21 that stores the fired product B1 discharged from the rotary kiln 7, a switching device 22 that switches the supply route of the fired product B1 discharged from the buffer tank 21 as necessary, and a switching device. 22, a measuring device 23 for measuring the radioactive cesium concentration of the baked product B2 discharged from 22, a switching device 24 for switching a route for supplying the baked product B2 based on a measurement value in the measuring device 23, and a non-defective product from the switching device 24 And a cooler 26 for cooling P.

  Waste W stored in storage tank 3 includes soil contaminated with radioactive cesium, incinerated ash, felled trees, waste-derived molten slag, sewage sludge, sewage sludge dry powder, purified water sludge, construction sludge, sewage slag, shells, All wastes such as vegetation, debris, and the like containing radioactive cesium can be targeted, and one kind included in these groups can be used alone, or two or more kinds can be combined. Further, an intermediate treatment product enriched with radioactive cesium obtained by removing in advance a portion containing almost no radioactive cesium (sand or stone in the case of soil) is also a waste W contaminated with radioactive cesium in the present invention. include.

As a CaO source stored in the storage tank 4, what contains calcium carbonate, quicklime, slaked lime, limestone, dolomite, blast furnace slag, etc. can be used. Further, a magnesium oxide source (MgO source) can be supplied instead of or together with the CaO source. As the MgO source, one containing magnesium carbonate (MgCO ₃ ), magnesium hydroxide (Mg (OH) ₂ ), dolomite, serpentine, ferronickel alloy slag, or the like can be used.

As the Cl source is stored in the storage tank 5, calcium chloride (CaCl _2), potassium chloride (KCl), sodium chloride (NaCl), it can be used waste plastics having a chlorine, of CaCl ₂ is It is preferable because radioactive cesium can be effectively removed.

  The rotary kiln 7 includes a kiln main body 7a for firing the mixed raw material M, a kiln front part 7b provided with a burner, and a kiln bottom part 7c provided with an inlet for introducing the mixed raw material M. A heating device other than the rotary kiln 7 can also be used.

  The cooling tower 8 is provided for cooling the exhaust gas G of the rotary kiln 7 and recovering radioactive cesium and the like volatilized from the waste W in a solid state. The exhaust gas G is cooled by spraying water from a sprinkler 8 a installed at the lower end of the cooling tower 8. In addition, this watering apparatus 8a should just be equipped with the function of the grade which can cool and collect | recover until radioactive cesium, such as volatilized cesium chloride, becomes a solid state. Further, instead of cooling with water, cooling may be performed by introducing cooling air into the cooling tower 8, or water and cooling air may be used in combination.

  The cyclone 9 as a classifier is provided for recovering coarse powder C mainly composed of calcium components from the exhaust gas G1 of the cooling tower 8.

  The first dust collector 10 is provided to collect the dust D1 containing the cesium salt concentrated as described above from the exhaust gas G2 of the cyclone 9, and a bag filter or the like is used.

  The 2nd dust collector 11 is provided in order to remove the acidic gas etc. which are contained in exhaust gas G3 after removing cesium salt etc., and neutralizer N which contains a calcium ingredient is neutralizer addition device (not shown) The dust D2 adsorbed with acid gas and the like is recovered. A bag filter or the like is also used for the second dust collector 11.

The denitration device 12 is introduced with the exhaust gas G4 of the second dust collector 11 into which ammonia gas (NH ₃ ) supplied from an ammonia gas addition device (not shown) is injected, and NOx contained in the introduced exhaust gas G4 is converted into nitrogen. Provided to reduce and render harmless.

  The buffer tank 21 is provided to temporarily store the fired product B1 and to discharge a predetermined amount of the fired product B1 at regular time intervals.

  The switching device 22 is, for example, a fired product B1 fired from the rotary kiln 7 at a predetermined temperature, for example, 1250 ° C. or less, a fire stop in the rotary kiln 7 (fuel or combustion air is burned from a burner installed in the kiln front portion 7b) The supply of the fired product B1 having a high radioactive cesium concentration, for example, exceeding several hundred to several thousand Bq / kg, such as the fired product B1 discharged from the rotary kiln 7 later, through the bypass route 25 Provided to return to 3.

  The measuring device 23 is provided for measuring the radioactive cesium concentration of the supplied fired product B2 using the amount of radiation (gamma rays) emitted from the supplied fired product B2 and the weight of the fired product B2. As shown in FIG. 2, the measuring device 23 includes a tank 23a that receives the fired product B2 from the switching device 22, a detector 23b that is provided in the tank 23a and detects radiation. The measuring device 23 receives a certain amount of the fired product B2 in the tank 23a, measures the amount of radiation emitted from the accepted fired product B2, discharges all of the fired product B2 from the tank 23a after the measurement, and newly creates the tank 23a. A batch system that accepts the fired product B2 can be used. A NaI detector is used as the detector 23b.

  In addition, since the measuring device 23 discharges the fired product B2 from the tank 23a after discharging the fired product B2 from the tank 23a, the measurement device 23 discharges the powder of the fired product B2 remaining in the tank 23a from the tank 23a. An air purge means (not shown) for blowing the gas into the tank 23a is provided.

  As shown in FIG. 2, the switching device 24 is configured such that when the measurement value of the radioactive cesium concentration of the fired product B2 in the measurement device 23 is equal to or less than a predetermined value V [Bq / kg], the fired product B2 discharged from the measurement device 23. Is supplied to the cooler 26 as a non-defective product P, and when the measured value exceeds a predetermined value V [Bq / kg], the fired product B2 is returned to the storage tank 3 as a defective product I2 via the bypass route 25.

  The cooler 26 is provided to cool the non-defective product P, and discharges the fired product B3. As the cooler 26, a rotary cooler, an air quenching cooler, or the like can be used.

  Next, the operation of the processing apparatus 1 having the above configuration will be described with reference to FIGS.

In the blending device 6, the waste W contaminated with radioactive cesium, the CaO source and the Cl source as reaction accelerators are drawn from the storage tanks 3 to 5, and these are blended to obtain the blending raw material M. The blended raw material M is an earthwork material that does not generate C ₃ S (alite) when fired, or a cement mixed material, or a cement clinker containing C ₃ S.

When producing an earthwork material or a cement mixed material, the relationship between CaO, SiO ₂ and MgO in the mixed raw material M satisfies (CaO + 1.39 × MgO) / SiO ₂ = 1.0 to 2.7, It is preferable to mix the waste W and the CaO source after determining their types and blending ratios. In the above relational expression, the mass of 1 mol of CaO corresponds to the mass of 1.39 mol of MgO, so the mass of MgO is multiplied by 1.39.

  When the mass ratio is less than 1.0, a liquid phase is likely to be generated as the firing temperature is increased, and the volatilization amount of radioactive cesium may be reduced. If the mass ratio exceeds 2.7, the total amount of volatilization of potassium and sodium in the waste W and the preparation raw material M contaminated with radioactive cesium increases, the alkali component in the coarse powder C increases, There is a concern that the amount of dust obtained by cooling the exhaust gas G2 may increase.

On the other hand, when producing a cement clinker, the waste is so disposed that the relationship between CaO, SiO ₂ and MgO in the raw material M satisfies (CaO + 1.39 × MgO) / SiO ₂ = 2.7 to 3.7. It is preferable to blend W and CaO sources after determining their types and blending ratios.

  When the mass ratio is 2.7 or more, the blended raw material M is difficult to melt, and thus more radioactive cesium can be volatilized. On the other hand, if the mass ratio exceeds 3.7, free lime (free lime) contained in the cement clinker increases, so that the quality of the cement may be deteriorated. In order to prevent these more reliably, it is preferable that the mass ratio satisfies 2.8 to 3.5. Furthermore, the desired cement clinker is adjusted by adjusting the silicic acid ratio (SM) of the blended raw material M to 1.3 to 3.0 and the iron ratio (IM) to 1.3 to 2.8. Can be manufactured.

  In addition, the amount of the Cl source is preferably adjusted so as to be equal to or greater than the radioactive cesium contained in the waste W, when any of earthwork materials, cement mixed materials, and cement clinker is manufactured. . The upper limit of the amount of the Cl source is such that the molar ratio Cl / (Cs + K) between chlorine, cesium and potassium is preferably 1.5 or less, more preferably 1.0 or less. When this molar ratio is 1.0 or less, radioactive cesium volatilizes while suppressing the volatilization amount of potassium and sodium, so that the volume of radioactive cesium-containing waste can be reduced.

  In addition, when manufacturing an earthwork material or a cement mixed material from the good product P, it is preferable to perform the said preparation and the following baking so that the calcium oxide density | concentration of the good product P may be 50 mass% or more. Thereby, since sulfur content is hold | maintained in earthwork materials, or it collects as dust D1 of exhaust gas G2 as a sulfur compound in the 1st dust collector 10 mentioned later, the circulation of sulfur content can be suppressed and the load of exhaust gas treatment is reduced. Increase and increase in coaching can be reduced.

  Next, the blended raw material M is charged into the rotary kiln 7 through the charging port of the kiln butt portion 7c, fired at 1200 ° C. or higher and 1550 ° C. or lower, and the obtained fired product B1 is discharged from the rotary kiln 7. Here, the oxygen partial pressure in the rotary kiln 7 is 3% or more, preferably 5% or more. Thereby, decomposition | disassembly of the sulfur compound in the rotary kiln 7 is suppressed, and the circulation of the sulfur content is suppressed. Therefore, increase in the amount of the neutralizer N used and increase in the amount of coating on the rotary kiln 7 and the cooling tower 8 are increased. Can be suppressed.

  In the rotary kiln 7, the radioactive cesium contained in the waste W is reacted with a Cl source to generate cesium chloride, and the exhaust gas G of the rotary kiln 7 containing the generated and volatilized cesium chloride is introduced into the cooling tower 8. Water is sprayed onto the exhaust gas G from the water sprinkler 8a in the cooling tower 8 to rapidly cool the exhaust gas G, and the cesium chloride contained in the exhaust gas G is converted into a solid cesium salt. The dust contained in the exhaust gas G1 of the cooling tower 8 is classified by the cyclone 9, and the coarse powder C obtained by the classification is combined with the prepared raw material M and charged into the rotary kiln 7.

  On the other hand, the exhaust gas G2 of the cyclone 9 containing the cesium salt is introduced into the first dust collector 10, and the dust D1 containing the solid concentrated cesium salt is recovered. The recovered dust D1 can be stored in a sealed container such as concrete after being further reduced in volume by compression, washing, adsorption, etc. as necessary. Waste containing radioactive cesium can be stored outside. The volume can be reduced and stored without leakage.

  Since the exhaust gas G3 of the first dust collector 10 after collecting the concentrated cesium salt contains harmful gas such as acid gas, the neutralizer N is added to the exhaust gas G3 from the neutralizer addition device, and then the acidic gas is added. The dust D2 adsorbing gas or the like is recovered from the exhaust gas G3 by the second dust collector 11. Here, as the neutralizing agent N, one containing at least one selected from the group consisting of slaked lime, quicklime, dolomite, light-burned dolomite and hydroxylated dolomite can be used. Since the recovered dust D2 is mainly composed of slaked lime, gypsum, and calcium chloride, it can be returned to the storage tank 4 and the storage tank 5 as a CaO source or Cl source and added to the waste W for reuse.

  Ammonia gas is added from the ammonia addition device to the exhaust gas G4 of the second dust collector 11, and the exhaust gas G4 after the addition is denitrated by the denitration device 12. The exhaust gas G5 after denitration is discharged from the chimney 13 to the atmosphere.

  On the other hand, the fired product B <b> 1 discharged from the rotary kiln 7 is conveyed by a bucket conveyor or the like and supplied to the buffer tank 21. About 60 kg of the fired product B1 is discharged from the buffer tank 21 at regular intervals and supplied to the switching device 22. Here, radioactive cesium such as a fired product B1 fired at a predetermined temperature or less from a rotary kiln 7 whose radiation concentration is expected to exceed the standard empirically, a fired product B1 discharged from the rotary kiln 7 after being fired in the rotary kiln 7, etc. The fired product B1 having a high concentration, for example, exceeding several hundred to several thousand Bq / kg is returned to the storage tank 3 through the bypass route 25 as a defective product I1. In addition, the fired product B1 for a certain period after the measurement value with the radiation concentration exceeding the reference value can be handled as the defective product I1.

  In addition, the fired product B <b> 2 discharged from the switching device 22 is supplied to the measuring device 23. Here, the measurement apparatus 23 measures the radioactive cesium concentration in the fired product B2 as follows. First, as shown in FIG. 2A, the radiation dose (background value) in the empty tank 23a is measured in advance. Next, as shown in FIG. 2B, the fired product B2 is supplied to the tank 23a, and the amount of radiation emitted from the fired product B2 is measured in the tank 23a. Furthermore, these differences are made into the radiation dose emitted from the baked product B2, and the amount of radioactive cesium contained in the baked product B2 is calculated from this radiation dose. Further, the weight of the fired product B2 is measured, and the radioactive cesium concentration of the fired product B2 is calculated from the weight of the fired product B2 and the amount of radioactive cesium contained in the fired product B2.

  However, once a high-concentration baked product B2 having a radioactive cesium concentration exceeding several hundred to several thousand Bq / kg is once supplied to the measuring device 23, fine particles contained in the baked product B2 become the inner wall of the tank 23a. If it adheres or remains on the corner or the surface of the detector 23b, the measuring device 23 is contaminated and the background value becomes high. Since the detection limit value of the measuring device 23 increases as the background value increases, for example, it is unreliable to measure a value below a clearance level of 100 Bq / kg.

  Further, when the calcined product B2 is measured in a state in which the measuring device 23 is contaminated, if the radioactive cesium concentration of the calcined product B2 is low, this serves as a shielding material, and thus the radiation dose detected by the detector 23b. May become lower than the background value, and as a result, the radioactive cesium concentration measured by the measuring device 23 may be negative.

  FIG. 3 shows the measured value of the radioactive cesium concentration of the fired product B2 by the measuring device 23 when the radiation dose (background value) in the empty tank 23a is 21 cps, 23 cps and 25 cps, respectively, and the same firing. The relationship between the product B2 and the actual radioactive cesium concentration of the fired product B2 measured separately with a germanium semiconductor detector is shown (in the same figure, “BG21 cps graph”, “BG23 cps graph”, “BG25 cps Equivalent to “Graph”).

  Here, the “graph of BG 25 cps” is a measurement result in a state where the measuring device 23 is contaminated. There is a case where the radioactive cesium measurement value by the measuring device 23 becomes negative due to the influence of shielding by the fired product B2. In addition, it is greatly deviated from the actual radioactive cesium concentration.

  On the other hand, the “BG21 cps graph” and the “BG23 cps graph” are the measurement results when the contamination level of the measurement device 23 is low, and the radiocesium measurement value obtained by the measurement device 23 and the actual radiocesium concentration are so large. Rather, the actual radioactive cesium concentration can be ascertained from the measurement value obtained by the measurement device 23. At this time, the relationship between the measured value of the radioactive cesium concentration of the fired product B2 by the measuring device 23 and the radioactive cesium concentration of the fired product B2 in the Ge detector is graphed in advance, and the above graph is used from the measured value of the measuring device 23. The radioactive cesium concentration of the fired product B2 may be calculated.

  Therefore, a high radioactive cesium concentration in the fired product B1 is transferred from the switching device 22 to the storage tank 3 via the bypass route 25 as a defective product I1 so that the radiation dose in the empty tank 23a is about 24 cps or less. While returning, it is preferable that air is appropriately blown into the tank 23a by the air purge means provided in the measuring device 23, and the radioactive cesium in the tank 23a is discharged from the tank 23a.

  Further, when the calcined product B2 discharged from the measuring device 23 is supplied to the switching device 24, and the measured value of the radioactive cesium concentration of the calcined product B2 in the measuring device 23 is equal to or less than a predetermined value V [Bq / kg], the measuring device 23 When the measured value exceeds a predetermined value V [Bq / kg], the fired product B2 discharged from the product is returned to the storage tank 3 as a defective product I2 and a defective product I1. . Moreover, when the radiation dose in the empty tank 23a of the said example is 25 cps or more, the baked product B2 can also be handled as inferior goods I2 until it falls below this.

  The non-defective product P is cooled by the cooler 26 and is crushed and crushed as a fired product B3, and cement clinker, cement mixed material, earthwork material (aggregate (aggregate for concrete, aggregate for asphalt)), It can be used as building materials such as backfill materials, embankment materials and roadbed materials. In addition, the use of baked product B3 measures the radioactive cesium density | concentration of baked product B3, and changes it according to the reference value of quality determination.

  The criteria for the above pass / fail judgment is basically the clearance level (100Bq / kg) that can be used for building materials, but it is intended for radioactive cesium-containing waste such as soil and rubble in highly contaminated areas. If the purpose is to reduce the exposure dose of workers engaged in the area as much as possible, a standard exceeding this may be used. That is, the quality determination criteria can be arbitrarily changed according to the radioactive cesium concentration of the fired product B3 that is the target processed product and the use of the non-defective product P.

  As described above, according to the above embodiment, the waste W contaminated with radioactive cesium is heated to recover the radioactive cesium, and the defective product I1 having a high concentration of radioactive cesium is not supplied to the measuring device 23. The measurement accuracy of the radioactive cesium concentration of the measuring device 23 can be maintained high, and a non-defective product P having a low radioactive cesium concentration and a fired product B3 having a low radioactive cesium concentration can be stably produced.

  Moreover, in the said embodiment, although the baked product B1 discharged | emitted from the rotary kiln 7 was supplied to the measuring apparatus 23, and quality determination was performed, the baked product B3 discharged | emitted from the cooler 26 is good also as an object of quality determination. Both of the fired products B1 and B3 discharged from the rotary kiln 7 and the cooler 26 may be subject to quality determination. When the baked product B3 discharged from the cooler 26 is to be subjected to quality determination, the baked product whose radioactive substance concentration measured in the previous stage of the cooler 26 is equal to or higher than a predetermined value is previously taken out of the system via a bypass route. By discharging, it can be excluded from the quality judgment.

  Further, in the above embodiment, the switching device 22 is provided in the subsequent stage of the buffer tank 21, but the switching device 22 may be provided in the previous stage of the buffer tank 21.

DESCRIPTION OF SYMBOLS 1 Processing apparatus 3-5 of the waste contaminated with radioactive cesium Storage tank 6 Preparation apparatus 7 Rotary kiln 7a Kiln main body 7b Kiln front part 7c Kiln bottom part 8 Cooling tower 8a Sprinkler 9 Cyclone 10 1st dust collector 11 2nd dust collector 12 Denitration Device 13 Chimney 21 Buffer tank 22 Switching device 23 Measuring device 23a Tank 23b Detector 24 Switching device 25 Bypass route 26 Cooler B1 to B3 Burned product C Coarse powder D1, D2 Dust G, G1 to G5 Exhaust gas I1 to I3 Defective product M Preparation Raw material N Neutralizer P Non-defective product W (Contaminated with radioactive cesium) Waste

Claims (4)

A heating device for heating waste contaminated with radioactive materials;
A recovery device for recovering the radioactive material volatilized by the heating;
A calcined product discharged from the heating device is supplied, and a measuring device for measuring a radiation dose emitted from the calcined product,
An apparatus for treating waste contaminated with a radioactive substance, comprising: a bypass route for discharging the fired product discharged from the heating device to the outside of the system without supplying it to the measuring device. The measuring device is
A tank for receiving the fired product discharged from the heating device;
A detector provided in the tank for detecting radiation;
2. The treatment of waste contaminated with a radioactive substance according to claim 1, further comprising an air purge means for blowing air discharged from the tank into the tank after firing detected in the tank after radiation detection. apparatus. The waste contaminated with radioactive material is heated, the radioactive material volatilized by the heating is recovered, and the calcined product obtained by the heating is supplied to a measuring device to measure the amount of radiation emitted from the calcined product. Hits the,
A method for treating a waste contaminated with a radioactive material, wherein the fired product obtained by the heating has a radioactive material concentration of a predetermined value or more discharged to the outside of the system without being supplied to the measuring device.   A fired product fired at a predetermined temperature or lower in the heating device, a fired product discharged from the heating device after being fired in the heating device, or a fired material having a radioactive substance concentration measured in the previous stage of the measuring device above the predetermined value. 4. The method for treating waste contaminated with a radioactive substance according to claim 3, wherein the waste is discharged out of the system without being supplied to the measuring device.