JP2013104743A - Separating and volume reducing device for radioactive waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separating and volume reducing device for radioactive waste which selectively removes low-level waste from waste including radioactive material, and can reduce the volume of radioactive waste to be stored with its treatment being on hold.SOLUTION: A separating and volume reducing device for radioactive waste 1 selects and removes radioactive waste AW of its radiation level higher than a reference value, from waste to be treated W which has been supplied from a waste supply unit 2. The separating and volume reducing device for radioactive waste 1 comprises: a belt conveyor 20 on which the waste to be treated W is transported and discharged by a separation unit 10 placed inside a radiation shield vessel 3; a decontamination unit 30 which decontaminates the belt conveyor 20 after the conveyor's discharging the waste to be treated W; a radiation level sensor 50 which detects a radiation level value of the waste to be treated W being transported on the belt conveyor 20 and inputs the radiation level value to a control unit 40; an extrusion unit 60 which removes the radioactive waste AW of its radiation level higher than the reference value from the waste to be treated W; and a radioactive waste recovery unit 70 which accommodates the radioactive waste AW removed from the waste to be treated W.

Description

  The present invention relates to a radioactive waste separation and volume reduction device for reducing and reducing the volume of low-dose substances from waste containing radioactive substances.

When decontamination treatment or incineration treatment of an object with radioactive substances (Iodine 131, Cesium 137, etc.) scattered in the atmosphere is performed, for example, sewage sludge after sewage treatment or incineration ash after incineration treatment, Ultimately, waste containing radioactive materials is discharged. Such waste may detect a high radioactive dose that exceeds a reference value because radioactive substances are concentrated in the process of sewage treatment or incineration.
The total amount of waste in which radioactive dose exceeding the reference value is detected becomes radioactive waste. However, since this radioactive waste cannot be disposed of normally such as landfill, it is stored in a predetermined manner with the disposal suspended.

The following Patent Document 1 discloses a system for efficiently and economically removing soil pollutants such as hydrocarbons, organic compounds, metals and radioactive substances.
In addition, Patent Document 2 below measures the radioactivity of radioactively contaminated waste that may be generated in large quantities at the time of decommissioning quickly and accurately, and effectively uses waste with extremely low radioactivity levels. In order to identify, a technique is disclosed in which a radiation detector having low detection efficiency but high resolution and a radiation detector having high detection efficiency but low resolution are used in combination.

Japanese National Patent Publication No. 5-503663 JP-A-5-341046

If the above-described radioactive waste is continuously subjected to processing such as decontamination, the radioactive waste will continue to accumulate in the storage place in a disposal pending state.
On the other hand, radioactive waste that is pending disposal has a large concentration of radioactive material (high and low distribution of the detected value of radioactive dose), so the low-dose material is selectively removed from waste containing high-dose radioactive material and the volume is reduced. It is desirable.

In other words, radioactive waste stored in a disposal hold does not necessarily have a high radioactive dose that exceeds the standard value. Therefore, by selecting the portion that actually has a high radioactive dose, It is desirable to reduce the amount of radioactive waste stored as it is.
The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to reduce the amount of radioactive waste that is selected and removed from low-dose substances from wastes containing radioactive substances and stored in a suspended state. It is an object of the present invention to provide a radioactive waste separation and volume reduction device that makes it possible.

In order to solve the above problems, the present invention employs the following means.
The radioactive waste separation and volume reduction device according to the present invention is a radioactive waste that selects and separates radioactive waste in which a radioactive dose of a reference value or more is detected from the treated waste supplied from the waste supply unit. A separation volume reduction device, wherein a sorting unit for sorting and separating the radioactive waste from the treated waste is installed inside a radiation shielding container, and the sorting unit is supplied from the waste supply unit A transport unit that transports the processing waste and delivers the waste from the inside of the sorting unit to the outside of the sorting unit, a decontamination unit that decontaminates the transport unit after dispensing the processing waste, and the transport unit transports the waste A radioactive dose detection unit that detects the radioactive dose value of the processing waste and inputs it to the control unit, and receives the operation signal from the control unit for the radioactive waste that has been determined that the radioactive dose value is higher than a predetermined value. said processing being transported Te A fractionation section to separate from the waste, and is characterized in being configured anda high dose substance recovery unit for receiving said radioactive waste was separated from the treated waste.

  According to such a radioactive waste separation and volume reduction apparatus of the present invention, the processing waste supplied from the waste supply unit is installed inside the radiation shielding container and performs the selection and separation of the radioactive waste. , Waste is separated into radioactive waste (high-dose substance) in which a high radiation dose above the reference value is detected and waste (low-dose substance) in which a low radiation dose that does not meet the standard value is detected. The volume of radioactive waste that must be stored on hold can be reduced.

The sorting of the radioactive waste in the sorting section described above is performed according to the following procedure while the transport section transports the processing waste supplied from the waste supply section and pays it out of the sorting section to the outside of the sorting section. .
When the processing waste being transported by the transporting unit passes through the radioactive dose detection unit, the radioactive dose value is detected, and this detection value is input to the control unit to determine whether it is radioactive waste. As a result, when it is determined that it is radioactive waste, the control unit outputs an operation signal to the separation processing unit, and the portion determined to be radioactive waste is separated from the processing waste being transported, resulting in a high dose. Housed in the material recovery unit.

On the other hand, the processing waste remaining without being stored in the high-dose substance recovery unit is transferred as it is by the transfer unit, and is discharged to the outside of the selection unit and collected. Accordingly, the processing waste is separated into radioactive waste housed in the high-dose substance recovery unit and normally disposable waste that is discharged to the outside of the sorting unit and collected.
In addition, since the transport unit that transports the processing waste supplied from the waste supply unit and pays it out from the sorting unit to the outside of the sorting unit includes a decontamination unit that decontaminates after the processing waste is paid out, It is possible to prevent the influence of radioactive waste (high radiation dose value) on the detection of the radioactive dose value of the radioactive dose detection unit at the time of subsequent conveyance, and therefore, it is possible to carry it repeatedly.

  In the above radioactive waste separation and volume reduction device, a waste determination unit for determining the waste size from the weight and / or appearance of the treated waste is provided, and the reference value of the radiation dose for selecting the radioactive waste is set as the reference value. It is preferable to change according to the size of the waste, so that the reference value for selecting the radioactive waste is a value defined according to the unit weight of the treated waste. Even if they are different, radioactive waste can be sorted with high accuracy.

In the radioactive waste separation and volume reduction device described above, by adopting a position detection type sensor in the radiation dose detection unit, it becomes possible to perform measurement including the dose distribution in the measurement target region, and finely sort out radioactive waste. Thus, the separation rate can be improved.
A suitable position detection type sensor in this case is an array type such as a cadmium tellurium (CdTe) array detector, and the dose distribution can be measured also in the direction intersecting the conveyance direction. Waste sorting becomes possible. Further, if a two-dimensional detector (for example, multi-grid type MSGE) is used as the position detection type sensor, it becomes possible to measure the dose distribution in the two-dimensional direction, so that it becomes possible to further finely select radioactive waste. To improve the separation rate.

  In the above radioactive waste separation and volume reduction apparatus, the separation / separation unit including the radioactive dose detection unit, the separation processing unit, and the high-dose substance recovery unit is provided in a plurality of stages from the upstream side to the downstream side of the transport unit. It is preferable that the detection range of the radioactive dose detection unit is set wider toward the front side and then gradually narrowed toward the rear side, thereby increasing the volume reduction rate by selecting the radioactive waste step by step from the processing waste. It becomes possible. Specifically, a wide-area monitoring type sensor (for example, a NaI (Ti) scintillation detector, etc.) is employed in the upstream radiation dose detector disposed on the upstream side to increase the processing speed, and on the downstream side. It is desirable to increase the dose monitoring accuracy by employing a high-precision sensor (for example, a Ge detector or the like) in the radioactive dose detector on the rear stage side.

  In this case, by installing a radionuclide distinguishing sensor such as a Ge detector in the radioactive dose detection unit on the rear side of the sorting / separating unit, it is possible to sort the radiation wastes having different nuclides. Therefore, since the radioactive waste is subjected to different final treatments (such as vitrification and landfilling) depending on the nuclide, it is possible to efficiently separate and collect each radioactive waste that can be subjected to the same treatment.

  In the above radioactive waste separation and volume reduction device, the transport unit is preferably a belt conveyor that continuously or intermittently transports the treated waste, thereby receiving the treated waste and the radioactive waste. It becomes an apparatus that can continuously operate the processing steps up to sorting and sorting, and the disposal of normally disposable waste. In particular, since it has a decontamination unit that decontaminates the belt conveyor (conveying unit) after the waste has been dispensed, the waste is continuously supplied from the waste supply unit to sort and sort the radioactive waste. Even if the operation is performed, the radioactive waste transported earlier does not affect the dose detection when sorting the radioactive waste from the treated waste transported later.

In the above radioactive waste separation and volume reduction device, the belt conveyor preferably includes a waste storage container for storing and transporting the treated waste, thereby sorting the radioactive waste from the treated waste. At the time of dose detection, the influence received from the processing waste in the adjacent waste storage container can be reduced, and the accuracy of dose measurement can be improved.
In this case, it is preferable that the waste container is provided with a variable volume mechanism, whereby not only processing waste such as sludge and incineration ash but also processing of debris whose shape and size are not uniform. It can also handle waste.

  According to the radioactive waste separation and volume reduction apparatus of the present invention described above, the portion of the radioactive waste that actually has a high radioactive dose is treated with respect to the treated waste that does not necessarily have a high radioactive dose that exceeds the reference value. By selecting and separating waste with a low radioactive dose below the standard value that can be normally disposed of in landfills, etc., it is possible to reduce the volume of radioactive waste that needs to be stored with disposal suspended. Become.

It is a schematic block diagram which shows the radioactive waste separation volume reduction apparatus which concerns on 1st Embodiment of this invention. In the first embodiment shown in FIG. 1, it is a diagram showing a state in which the separation processing unit that separates radioactive waste from the processing waste being conveyed has been separated. In 1st Embodiment shown in FIG. 1, it is a figure which shows the 1st modification of the separation process part which isolate | separates radioactive waste from the process waste in conveyance. In the first embodiment shown in FIG. 1, it is a diagram showing a second modification of the separation processing unit for separating the radioactive waste from the processing waste being conveyed, (a) is a side view, (b) is a main part It is an expansion perspective view. It is a schematic block diagram which shows the radioactive waste separation volume reduction apparatus which concerns on 2nd Embodiment of this invention. In 2nd Embodiment shown in FIG. 5, it is a figure which shows the state which the separation process part which isolate | separates a radioactive waste from the process waste in conveyance has completed isolation | separation. In 2nd Embodiment shown in FIG. 5, it is a figure which shows the 1st modification of the separation process part which isolate | separates a radioactive waste from the process waste in conveyance. In 2nd Embodiment shown in FIG. 5, it is a figure which shows the 2nd modification of the separation process part which isolate | separates radioactive waste from the processing waste in conveyance. It is a figure which shows the relationship between a waste size (Kg) and a waste dose (Bq) as an example about the reference value (threshold value) for determining with radiation waste. It is a schematic block diagram which shows the structural example of the principal part about the radioactive waste separation volume reduction apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the structural example which multistaged the radioactive waste separation volume reduction apparatus as 4th Embodiment of this invention.

Hereinafter, an embodiment of a radioactive waste separation and volume reduction device according to the present invention will be described with reference to the drawings.
Radioactive waste separation and volume reduction equipment is a standard value due to adhesion of radioactive materials scattered in the atmosphere from processing waste normally disposed of by burial, such as sewage sludge, incineration ash, and debris. It is an apparatus for selecting and separating the radioactive waste that has detected the above high radiation dose. In other words, since radioactive waste cannot be disposed of normally, such as buried disposal, it is necessary to reduce the volume of radioactive waste contained in the treated waste and to store the radioactive waste with the disposal suspended. It is a device that enables space reduction.

<First Embodiment>
The radioactive waste separation and volume reduction device 1 of the embodiment shown in FIG. 1 includes a waste supply device (waste supply unit) 2 that supplies treated waste W such as sewage sludge, incineration ash, and debris, and this waste supply. The radioactive waste AW is sorted out from the processing waste W supplied from the apparatus 2 and separated into the normal waste SW that is a normal disposal waste and the radioactive waste AW that is stored with the disposal suspended. And a sorting device (sorting unit) 10.
The waste supply device 2 used here may adopt either a method of continuously supplying the processing waste W or a badge method, and it depends on a conveyance method of a belt conveyor (conveyance unit) 20 described later. What is necessary is just to select suitably.

The radioactive waste (high-dose substance) AW described above is defined by the relationship between the waste size (Kg) and the waste dose (Bq), for example, as shown in FIG. In the example shown in FIG. 9, the reference value (threshold value) for determining the radioactive waste AW is 8000 Bq / Kg. Therefore, if a high radiation dose exceeding this reference value is detected and enters a high-dose region, it is recognized as a radioactive waste (high-dose substance) AW, and a low radiation dose that does not meet the reference value is detected and low. When entering the dose area, it is recognized as a normal waste (low dose substance) SW that can be normally disposed of.
That is, the waste (part) where the radioactive dose per unit weight detected from the treated waste W is equal to or higher than a predetermined reference value is recognized as the radioactive waste AW, and other parts (regions) are identified. It is recognized as a normal waste SW that can be normally disposed of.

  The sorting of the radioactive waste AW in the sorting unit 10 will be described below while the transport unit 10 transports the processing waste W supplied from the waste supply unit 2 and pays it out from the sorting unit to the outside of the sorting unit. Implemented by the procedure. Hereinafter, the flow until the radioactive waste AW is sorted and separated together with the details of the components of the sorting unit 10 will be described.

Since the sorting unit 10 sorts and separates the radioactive waste AW from the processing waste W, it is installed inside the radiation shielding container 3 made of, for example, a lead plate. The radiation shielding container 3 includes an inlet opening 4 for supplying the treated waste W from the waste supply device 2, an outlet opening 5 for discharging the normal waste SW after sorting, and a radioactive substance recovery device (to be described later after sorting) ( A collection outlet (not shown) for taking out the radioactive waste AW stored in the high-dose substance collection unit 70 is provided.
In addition, about the opening parts, such as the entrance opening 4 and the exit opening 5, an appropriate radiation countermeasure is taken as needed.

  The sorting unit 10 installed inside the radiation shielding container 3 includes a belt conveyor (conveying unit) 20 that transports the processing waste W supplied from the waste supply unit 2 and delivers it from the inside of the sorting unit to the outside of the sorting unit. The decontamination device (decontamination unit) 30 for decontaminating the conveying surface of the belt conveyor 20 after the processing waste W (in this case, the normal waste SW) is dispensed, and the processing waste conveyed by the belt conveyor 20 Radiation dose sensor (radioactive dose detection unit) 50 that detects the radioactive dose value of the object W and inputs it to the control unit (waste determination unit) 40, and the radioactive waste that has been determined that the radioactive dose value is higher than a predetermined value An extruding device (separation processing unit) 60 that receives an operation signal from the control unit 40 and separates the AW from the processing waste W being transported, and a radioactive material recovery that contains the radioactive waste AW separated from the processing waste W apparatus Constituted by including the high-dose substance recovery unit) 70, a.

  The illustrated belt conveyor 20 is a general conveying device that rotates a wide conveying belt 21 in a ring shape by connecting both ends, and is supplied from the waste supply device 2 onto the conveying surface of the conveying belt 21. The treated waste W is placed and moved from the inlet opening 4 to the outlet opening 5 at a constant speed. In this case, the processing waste W is continuously supplied from the waste supply device 2 disposed above the transport surface of the transport belt 21.

In the conveyance direction of the belt conveyor 20, the radiation dose sensor 50 and the extrusion device 60 are sequentially arranged with a predetermined interval from the supply position of the processing waste W toward the downstream side in the conveyance direction.
The radiation dose sensor 50 detects the radioactive dose value of the processing waste W conveyed by the belt conveyor 20 and inputs it to the control unit 40. The radiation dose sensor 50 is a wide-area monitoring type sensor such as a NaI (Ti) scintillation detector, and is fixed above the conveyance surface of the conveyance belt 21 with a predetermined interval. The radioactive dose value detected by the radiation dose sensor 50 is input to the control unit 40 via the signal line 51.

In this case, the radiation dose sensor 50 detects the radioactive dose value within the range of the length L (hatched portion) in the transport direction for the processing waste W that is placed on the transport belt 21 and continuously transported. This length L varies depending on various conditions of the components constituting the sorting unit 10, such as the detection performance of the radiation dose sensor 50, the conveyance speed of the belt conveyor 20, the processing capability of the extrusion device 60, and the like. is there.
Further, the belt conveyor 20 is not limited to continuous conveyance. For example, the belt conveyor 20 can be intermittently operated to stop at the time of measurement, or detected by changing the conveyance speed at the time of conveyance and at the time of measurement. Accordingly, the processing waste supply of the waste supply device 2 is also adjusted accordingly.

The radioactive dose value thus detected is input to the control unit 40, and it is determined whether the radioactive dose is a radioactive waste AW or a normal waste SW.
That is, since the waste size can be estimated from the processing waste supply amount of the waste supply apparatus 2, the control unit 40 compares the detected radioactive dose value and the estimated waste size value with a threshold value, and detects the detection target. It is possible to determine whether or not the processing waste W is a radioactive waste AW of a high-dose substance. In other words, the control unit 40 changes the reference value of the radiation dose for selecting the radioactive waste AW according to the waste size of the processing waste W, and the detected radioactive dose as the waste size is larger. The criterion value for the value also increases.

  When the control unit 40 determines that the radioactive waste is AW, an operation signal is output to the extrusion device 60. However, the processing waste W that is determined not to be the radioactive waste AW passes through the extrusion device 60 without being operated. As a result, the processing waste W whose radioactive dose value is lower than the threshold value is discharged out of the sorting unit 10 from the outlet opening 5 as normal waste SW.

The illustrated extrusion device 60 includes a pressing plate 62 that is installed near the side surface of the belt conveyor 20 and that expands and contracts in a direction substantially perpendicular to the conveying direction (see the white arrow 61 in FIG. 2). The pressing plate 62 uses, for example, a hydraulic cylinder, a pneumatic cylinder, or the like as a drive source and moves so as to cross the conveyance surface from the vicinity of the side surface of the belt conveyor 20, thereby treating the radioactive waste AW on the conveyance surface with the processing waste W. It is a device that performs separation processing.
Note that the pressing plate 62 of the extrusion device 60 shown in FIG. 1 is in a standby position before receiving the operation signal, and the pressing plate 62 shown in FIG. 2 has completed the separation process of the radioactive waste AW upon receiving the operation signal. Indicates the state.

The radioactive waste AW separated by the extrusion device 60 is dropped and collected on the radioactive material recovery device 70 disposed below the side surface of the belt conveyor 20 on the side opposite to the extrusion device 60. This radioactive substance recovery device 70 is installed with the upper surface opened, and after a predetermined amount is recovered, it is sealed with a lid.
In addition, it is desirable that the radioactive substance recovery device 70 be made of a material or a structure that takes radiation countermeasures as necessary.

  As a result, the processing waste W supplied from the waste supply unit 2 is installed in the radiation shielding container 3 and is sorted and separated from the radioactive waste W. The screening unit 10 sorts and separates the radioactive waste W, and the radiation dose is higher than the reference value. Is separated into the radioactive waste AW in which the radioactive ray is detected and the normal waste SW in which the low radiation dose that does not satisfy the standard value is detected. It becomes possible to reduce the volume.

  In this way, the belt conveyor 20 after the normal waste SW has been paid out is turned back to be transported again. The belt transport surface 21 in such a folded state is decontaminated (decontamination unit) 30. The transport surface is decontaminated by water spray or the like. By performing this decontamination, the radioactive material adhering to the radioactive waste AW is removed. For this reason, when the radioactive dose is detected by the radiation dose sensor 50, there is no influence of the radioactive waste AW conveyed last time. Therefore, the radioactive dose value of the processing waste W is accurately determined at each conveyance. Therefore, it is possible to carry it repeatedly.

  As described above, in the sorting unit 10 of the present embodiment, the radioactive dose value is detected when the processing waste W being conveyed by the belt conveyor 20 passes the radiation dose sensor 50, and the detected value is input to the control unit 40. Then, it is determined whether or not the radioactive waste is AW. As a result, when it is determined that the waste is AW, the control unit 40 outputs an operation signal to the extrusion device 60, and only the portion determined as the radioactive waste AW from the processing waste W being transported is output. Separated and accommodated in the radioactive substance recovery device 70.

  On the other hand, the normal waste SW that has passed through the extrusion device 60 without being accommodated in the radioactive material recovery device 70 is conveyed as it is by the belt conveyor 20, and then is discharged to the outside of the sorting unit and collected in a predetermined container or the like. The Therefore, the radioactive waste that requires special measures, such as disposal waste W, must be stored in a disposal pending state due to separation and removal of ordinary waste SW that can be treated normally such as landfill. It is possible to reduce the storage space by reducing the volume AW.

By the way, a classification process part is not limited to the extrusion apparatus 60 of embodiment mentioned above, A various modification is possible.
The separation processing unit of the first modification shown in FIG. 3 has a conveying bottom plate 63 installed on the conveying surface with respect to the conveying belt 21A of the belt conveyor 20A, and is currently conveying the conveying bottom plate 63 so as to jump up. The radioactive waste AW is separated from the treatment waste W. That is, on the upper surface (outer peripheral surface) of the conveying surface of the conveying belt 21A, a large number of conveying bottom plates 63 that are divided in the conveying direction are arranged, and each of them is configured to be flipped up by a drive mechanism (not shown). ing.

The conveyance direction dimension (plate width) of the conveyance bottom plate 63 is determined so as to substantially coincide with the conveyance direction detection range of the radiation dose sensor 50. The bottom plate 63 for conveyance is supported on the belt conveyor 20A side through a swinging support member (not shown) such as a hinge on one side surface that intersects the conveyance direction.
With such a configuration, when the control unit 40 determines that the radioactive waste is AW and outputs an operation signal, the transport bottom plate 63 is operated by a drive mechanism using a hydraulic cylinder or the like as a drive source. The other side rises with fulcrum as the fulcrum. As a result, the transfer bottom plate 63 is inclined, so that the radioactive waste AW placed on the upper surface of the transfer bottom plate 63 and being transferred is slid down into the radioactive substance recovery device 70 and recovered.

The separation processing unit of the second modification shown in FIG. 4 is provided with a large number of openable and closable openings 64 penetrating the conveyance surface with respect to the conveyance belt 21B of the belt conveyor 20B. In this case, the inner peripheral surface side of the belt conveyor 20B becomes the conveying surface, and the processing waste W is supplied from a waste supply device (not shown) to the upper surface of the conveying belt 21B passing through the lower side.
In the configuration example shown in the figure, the door 65 is rotated 90 degrees downward and opened and closed by a driving mechanism (not shown) to form an opening 64 in the transport belt 21B. It is good also as a structure which opens and closes completely or inclines below.

Even if such a configuration is adopted, when the control unit 40 determines that the radioactive waste is AW and outputs an operation signal, the doors 65 formed on the conveyor belt 21B are moved downward to open the opening 64. Since it is opened, the radioactive waste AW that is placed at the part of the door door 65 and is being transported falls to the radioactive substance recovery device 70 of the high-dose substance recovery container and is recovered.
Further, in such a configuration, the normal waste SW that has passed without being stored in the radioactive substance recovery device 70 also falls into the low-dose substance recovery container 71 from the open / close-type opening 66 that is similarly configured. And recovered. Note that the opening 66 in this case is formed by detecting the position of the low-dose substance collection container 71 and the like so that the sound door 67 opens downward.

Second Embodiment
Next, a radioactive waste separation and volume reduction device according to a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above and a modification, and the detailed description is abbreviate | omitted.
The illustrated radioactive waste separation and volume reduction apparatus 1A includes a weight measuring device 80 for processing waste W and image processing, in addition to the belt conveyor 20C of the conveyance unit and the drive mechanism of the separation processing unit constituting the sorting device 10A. The difference is that a shape determination device 90 is provided.

  Specifically, the belt conveyor 20C of the sorting apparatus 10A includes a waste storage container 22 that divides and stores the supplied processing waste W on the transport surface of the transport belt 21C. The illustrated waste storage container 22 is a substantially rectangular parallelepiped container having an open upper surface, and many waste storage containers 22 are installed in the conveying direction of the belt conveyor 20C. When such a waste container 22 is used, it is possible to reduce the influence of the processing waste W transported forward and backward on the measurement of the radioactive dose value, which is effective in improving the dose measurement accuracy.

In addition, the waste container 22 described above is supported by a hinge 22a or the like so that one side surface of the bottom surface is swingable with respect to the conveyor belt 21C. Furthermore, since the waste container 22 includes a drive (reversing) mechanism 68 that operates in response to an operation signal from the control unit 40A when it is determined as radioactive waste AW, for example, as shown in FIG. The radioactive waste AW in the container can be dropped into the radioactive substance recovery device 70 by reversing 180 degrees.
The drive mechanism 68 shown in FIG. 6 moves up and down so as to lift the bottom of the opposite side of the waste container 22 supported swingably by the hinge 22a from below, but is limited to this. There is no.

Further, the belt conveyor 21D of the first modified example shown in FIG. 7 includes an extrusion device (not shown) for exchanging containers by extruding an empty waste storage container 22A. That is, in this modification, since the empty waste container 22A is pushed out in the direction intersecting the transport direction by the operation of the extrusion device, the radioactive waste AW is stored by adjusting the operation timing of the extrusion device. The waste container 22A being conveyed by the conveyance belt 21D is pushed out from the conveyance surface of the conveyance belt 21D to the side, and the container is exchanged.
Note that the waste storage container 22A pushed sideways from the transport surface of the transport belt 21D can be recovered by the radioactive material recovery device 70 by collecting the radioactive waste AW inside by opening the bottom surface or rotating the container. Good.

Further, the belt conveyor 21E of the second modified example shown in FIG. 8 is generally a system in which the belt conveyance surface 21E is intermittently operated, and a driving device (not shown) is temporarily stopped at the collection position of the radioactive waste AW. Operates to move the waste container 22B to above the radioactive substance recovery device 70. The waste container 22B that has reached the upper side of the radioactive substance recovery device 70 recovers the internal radioactive waste AW to the radioactive substance recovery device 70 by opening the bottom surface or rotating the container. Pulled back into position.
After separating and separating the radioactive waste AW in this way, the belt conveyor 21E may be operated again and conveyed. The belt conveyor 21E may be temporarily stopped only when the processing waste in the waste storage container 22B is radioactive waste AW.

  The weight measuring device 80 in FIG. 5 measures the weight of the processing waste W being conveyed by the waste storage container 22 for each container, and for example, a load cell is used. Weight data for each container measured by the weight measuring device 80 is input to the control unit 40A and used to determine whether or not the processing waste W is radioactive waste AW.

5 is a device for determining the shape and size of the processing waste W being conveyed (hereinafter referred to as “waste size”) by image processing, and a camera 91 for obtaining image data. And an image processing unit 92 that determines the waste size based on the image data input from the camera 91. The waste size data obtained by the image processing unit 92 is input to the control unit 40A and used to determine whether or not the processing waste W is radioactive waste AW.
In this case, only one of the weight measuring device 80 and the shape determining device 90 may be used, or both may be used together to improve measurement accuracy. In particular, when handling the processing waste W having a substantially constant specific gravity, if the shape (volume) is known, the weight can be estimated almost accurately, so only the state determination device 90 may be used.

In this way, when actual measurement data of the weight and waste size of the processing waste W is obtained for each transport container, the first estimation of the waste size from the processing waste supply amount and the like of the waste supply device 2 is performed. Compared to the embodiment, more accurate waste size data can be obtained.
As a result, as shown in FIG. 9 as an example, when determining whether or not the radioactive waste AW is based on the threshold value, the data accuracy regarding the waste size (Kg) serving as the denominator is improved, so that the more accurate Judgment becomes possible.

  That is, in the radioactive waste separation and volume reducing apparatus 1A, a control unit 40A for determining the waste size from the weight and / or appearance of the treated waste W is provided, and the reference value of the radiation dose for selecting the radioactive waste AW is discarded. Since the reference value for selecting the radioactive waste AW is a value defined according to the unit weight of the treated waste W, the shape and weight of the treated waste W are different. Even if it exists, the highly accurate sorting of the radioactive waste AW becomes possible.

<Third Embodiment>
Next, a radioactive waste sorting and volume reducing device according to a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above and a modification, and the detailed description is abbreviate | omitted.
In this embodiment, a position detection type sensor 50A is employed in place of the radiation dose sensor 50 of the radiation dose detection unit in the radioactive waste separation and volume reduction device 1, 1A described above. The position detection type sensor 50A can measure by dividing into a plurality of width directions (width direction of the conveyor belt 21) intersecting the conveyance direction. That is, it becomes possible to perform measurement including the dose distribution in the measurement target region, and it is possible to improve the separation rate by finely selecting the radioactive waste.
In the illustrated position detection type sensor 50 </ b> A, the width direction of the inspection region is divided into 6 by a to f, but is not limited thereto.

  Such a position detection type sensor 50A has an array type such as a cadmium tellurium (CdTe) array detector, and can measure the dose distribution in the direction intersecting the conveyance direction, so that fine radioactive waste is obtained. Can be selected. Therefore, if the opening 69 that penetrates the conveyance surface of the conveyance belt 21F is provided by dividing the width direction into six so as to correspond to the detection regions a to f of the position detection type sensor 50A, finer selection and separation are possible. It becomes possible.

In the illustrated configuration example, when the inspection region of the processing waste W is divided into six in the width direction, the portion corresponding to the inspection region c of the position detection type sensor 50A is the low-dose substance normal waste SW, and the other portions Are all high-dose radioactive waste AW. Therefore, if the dose distribution in the width direction can be measured by the position detection type sensor 50A, the opening / closing operation of the openings 69 divided into six rows is performed when passing over the radioactive substance recovery apparatus 70 for recovering the high dose substance. The radioactive waste AW is collected by opening five locations excluding the portion corresponding to the region c. Further, the remaining normal substance SW is collected by opening all the openings 69 when passing over the low-dose substance collection container 71 for collecting the low-dose substance.
As a result, the radioactive waste AW selected from the treatment waste W is reduced to a state where the ratio of the normal waste SW is low.

  Further, instead of the position detection type sensor 50A described above, for example, a two-dimensional detector such as a multigrid type MSGE may be adopted. By adopting such a two-dimensional detector, it becomes possible to measure a dose distribution in a two-dimensional direction, so that it becomes possible to select a more detailed radioactive waste AW and further improve the classification rate.

<Fourth embodiment>
Next, for the radioactive waste separation and volume reduction device according to the fourth embodiment of the present invention, as in the radioactive waste separation and volume reduction device 1B shown in FIG. A two-stage sorting / separating unit including a radioactive dose detection unit such as the radiation dose sensors 50 and 50A, a separation processing unit such as the extrusion device 60, and a high-dose substance recovery unit such as the radioactive substance recovery device 70 It is good also as a structure which provided S1, S2.
In this case, it is desirable to provide two or more stages (a plurality of stages) from the upstream side to the downstream side of the belt conveyor 20 and to set the detection range of the sensor serving as the radioactive dose detection unit wider toward the front side and gradually narrow it toward the rear side.

  Specifically, the sorting / separating unit S1 that is arranged upstream and performs the first-stage detection of the preceding stage employs a wide-area monitoring type sensor (for example, a NaI (Ti) scintillation detector) as the radioactive dose detection unit. In the sorting / separating unit S1 which increases the processing speed and is arranged downstream and performs high-accuracy detection on the downstream side, a high-accuracy sensor (for example, a Ge detector) is used as the radioactive dose detection unit to monitor the dose. The accuracy may be increased. In this way, if a sensor with high processing accuracy is adopted step by step in the multi-stage sorting / separating sections S1, S2, the radioactive waste AW is quickly and accurately sorted from the processing waste W and the volume reduction rate is reduced. Can be increased.

  In addition, if a nuclide distinguishing sensor such as a Ge detector is installed on the downstream side of the sorting / separating units S1 to Sn, particularly the radiation dose sensor in the final stage, it is possible to sort the radiation waste AW having different nuclides. Become. Since the final treatment after separation differs depending on the nuclide of the radioactive waste AW, for example, vitrification or landfilling, it is possible to efficiently separate and collect each radioactive waste AW that can be treated in the same way. Thus, a new separation process is not required until the final process.

As described above, according to the radioactive waste separation and volume reduction device of the present embodiment described above, the volume of the radioactive waste AW can be reduced, so that the space necessary for storing the radioactive waste AW can be reduced. In other words, since the total amount of the treated waste W is not necessarily a radioactive waste AW having a high radioactive dose that exceeds the reference value, the portion of the radioactive waste AW that actually has a high radioactive dose can be disposed of normally such as landfill. If you sort and sort from normal waste SW with low radioactive dose less than the standard value, you can reduce the volume and weight of the amount of radioactive waste AW that needs to be kept in disposal. Become.
In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary, it can change suitably.

1,1A radioactive waste separation and volume reduction equipment 2 Waste supply equipment (waste supply section)
3 Radiation shielding container 10, 10A Sorting device (sorting section)
20, 20A-20E Belt conveyor (conveyance unit)
21, 21A-21F Conveyor belt 22 Waste storage container 30 Decontamination equipment (decontamination part)
40, 40A control unit (waste determination unit)
50 Radiation dose sensor (radiation dose detector)
50A Position detection type sensor 60 Extruder (sorting processing unit)
62 Pressing plate 63 Bottom plate for conveyance 64, 66 Opening 68 Driving mechanism 70 Radioactive substance recovery device (high dose substance recovery part)
80 Weight measuring device 90 Shape determination device W Processing waste AW Radioactive waste (high-dose substance)
SW Normal waste (low-dose material)
S1, S2 sorting section

Claims (8)

A radioactive waste separation and volume reduction device that sorts and separates radioactive waste in which radioactive doses greater than the reference value are detected from the treated waste supplied from the waste supply unit,
A sorting section for sorting and separating the radioactive waste from the treated waste is installed inside the radiation shielding container,
The sorting unit conveys the processing waste supplied from the waste supply unit and delivers the processing waste from the inside of the sorting unit to the outside of the sorting unit, and decontaminates the conveying unit after discharging the processing waste A decontamination unit, a radioactive dose detection unit that detects a radioactive dose value of the processing waste conveyed by the conveyance unit and inputs it to the control unit, and the radioactive dose value is determined to be higher than a predetermined value. In addition, a separation processing unit that receives the operation signal from the control unit and separates the radioactive waste from the processing waste being transported, and a high-dose material recovery unit that stores the radioactive material separated from the processing waste And a radioactive waste separation and volume reduction device.   A waste determination unit for determining a waste size from the weight and / or appearance of the treated waste is provided, and a reference value of a radiation dose for selecting the radioactive waste is changed according to the waste size. The radioactive waste separation and volume reduction device according to claim 1.   The radioactive waste separation and volume reduction device according to claim 1, wherein the radiation dose detection unit is a position detection type sensor.   A plurality of separation / separation units including the radioactive dose detection unit, the separation processing unit, and the high-dose substance recovery unit are provided from the upstream side to the downstream side of the transport unit, and the detection range of the radioactive dose detection unit is set on the front side. The radioactive waste separation and volume reducing device according to any one of claims 1 to 3, wherein the device is set to be wider and is gradually narrowed toward the subsequent stage.   5. The radioactive waste separation and volume reducing device according to claim 4, wherein a nuclide distinguishing sensor is installed in the radioactive dose detection unit on the rear side of the sorting and separating unit.   The radioactive waste separation and volume reducing device according to claim 1, wherein the transport unit is a belt conveyor that transports the treatment waste continuously or intermittently.   The radioactive waste separation and volume reducing device according to claim 6, wherein the belt conveyor includes a waste storage container for storing and transporting the processing waste. The radioactive waste separation and volume reducing device according to claim 7, wherein the waste container includes a variable volume mechanism.

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