JP2002311191A - Decontamination equipment for radioactive decontamination - Google Patents

Abstract

(57) [Problem] To provide a series of cleaning and decontamination equipment for reducing the amount of waste of radioactive decontamination objects. An object to be decontaminated 5 is loaded on a belt conveyor 3 and carried into a shielding room 1, and is further washed by a cleaning device 7 in the process of being further transported by the belt conveyor 3 in the shielding room 1, and further transported. As the radiation progresses, the degree of radiation contamination of each part is grasped by the radiation dose measuring device 8, and when the radiation contamination measurement proceeds further, the portion having a high radiation contamination is decontaminated by jet water from the high-pressure jet nozzle 9 or polishing by the multi-axis processing machine 11. When proceeding, the entire surface of the radioactive decontamination target is subjected to decontamination processing by the wide-area decontamination device 14 such as an ultrasonic decontamination device, and when further proceeding, the decontamination treatment is performed again by the cleaning device 15 and the belt conveyor from the shielding room 1 It is conveyed at 3 and taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The technology of the present invention is used for decontamination equipment for radioactive decontamination objects.
It is suitable for decontamination technology of radioactive solid waste generated by radiation environment in nuclear facilities such as nuclear power plants.

[0002]

2. Description of the Related Art As a known example related to the present invention, there is a technique disclosed in Japanese Patent Application Laid-Open No. 2001-13292. In order to make it possible to recycle an iron shield, the technology protects the surface by applying a coating material to the iron surface via a release material in order to prevent the adhesion of radioactive substances.

[0003] With this, the surface is protected so that radioactive substances do not adhere to iron, and when recycling iron, the coating material is peeled off from the iron surface together with the radioactive material via a release material to recycle iron. It is easy to do.

[0004] Further, small articles such as tools and instruments used in work in nuclear facilities such as nuclear power plants are used by workers, so radioactive materials that are extremely hard in a working environment. There is no occurrence of adhesion, and it is carried out and reused by simple hand wiping decontamination using cloth or paper.

[0005]

Recycling of radioactive solid waste from nuclear facilities in an existing radiation environment has no such surface protection, and it is difficult to apply the coating after installation. For radioactive solid waste at nuclear facilities, it was necessary to take measures including removal of radioactive materials.

[0006] Further, for small articles such as tools and instruments used in operations in the nuclear facilities,
They are carried out and reused by simple decontamination by hand wiping. However, for radioactive solid waste whose surface condition (surface roughness, structure, etc.) is extremely deteriorated in the facilities at nuclear facilities, it is not possible to remove radioactive contaminants by decontamination such as by hand-wiping. In addition, when radioactive material adheres to an object whose surface is uneven due to damage or deterioration, it is difficult to remove the radioactive material that has entered the surface unevenness using conventional decontamination technology. Therefore, it is necessary to improve the decontamination method because the recycling / reproduction becomes difficult.

[0007] From the above situation, in the treatment of radioactive solid waste in nuclear facilities, the radiation dose of the product to be disposed and the degree of contamination by radioactive substances on the surface are clearly classified, and the waste is packed by drum cans and pallets. After being stored or stored in a storage building, it is buried in a radioactive waste treatment facility and stored for about 200 years before final disposal. Until buried, a waste storage building is built / expanded in a nuclear facility. And stores / manages radioactive solid waste. As a result, the cost of radioactive solid waste disposal at nuclear facilities was incurred.

[0008] Among the radioactive solid wastes, lead materials cannot be buried in a radioactive waste treatment facility due to the problem of lead harm and the like. While increasing, waste disposal costs were continuously incurred.

The radioactive solid waste treatment costs include shredding costs for radioactive solid waste for drum canning and palletizing, and transportation costs for storing or storing radioactive solid waste in a waste storage building. In addition, there is a cost to transfer radioactive solid waste from nuclear facilities to the radioactive waste disposal facility for burial disposal.

[0010] Therefore, it is necessary to implement measures for economically reducing the amount of radioactive solid waste. After confirming the radiation dose and the degree of contamination, decontamination is carried out, and the waste is carried out as general waste. There is scope for reusable methods. At the same time, in recent years, there has been a demand for improving the global environment worldwide, and it is urgently necessary to formulate a method for achieving reduction of radioactive solid waste.

However, the means and devices that can be decontaminated and carried out as municipal waste from the confirmation of the radiation dose and the degree of contamination are delayed in terms of economy and equipment layout, and are not installed. It is the current situation.

[0012] In particular, in the decontamination according to the prior art, radiation work is required, and exposure and economy in the work have been problems. For this reason, decontamination has not become a major trend to reduce radioactive solid waste, and a decontamination device that enables decontamination under non-radiation and reduces exposure is developed. I needed to.

Accordingly, it is an object of the present invention to provide a decontamination apparatus for reducing radioactive decontamination objects such as radioactive solid wastes originally intended for disposal.

[0014]

Means for solving the problems of the present invention are: a cleaning device for a radioactive decontamination object;
A radiation dose measuring device for the radioactive decontamination target, a decontamination device for the radioactive decontamination target, and sequentially transporting the radioactive decontamination target to the cleaning device, the radiation dose measuring device, and the decontamination device. The decontamination equipment for radioactive decontamination objects equipped with a transport line that reduces the radiation exposure of workers to the radioactive decontamination target sequentially in the middle of the transport line where the radioactive decontamination target moves In order to remove the radioactive material by washing, and then measure and confirm the radiation dose, then perform appropriate decontamination work with a decontamination device to reduce the radiation dose of the radioactive decontamination target. Reduced for easier handling.

Further, if another cleaning device for cleaning the radioactive decontamination object after decontamination by the decontamination device is provided along the transport line, the radioactive decontamination object after decontamination is cleaned again. And it becomes easier to handle without leaving the effect of decontamination,
By providing another radiation dose measuring device for the radioactive decontamination target after receiving the decontamination action in the decontamination device, the decontamination result can be confirmed by measurement by another radiation dose measuring device, the degree of decontamination Can be grasped and safety is improved.

Further, if means for receiving and dissolving the radioactive decontamination object after decontamination by the decontamination apparatus is provided along the transport line, a small radioactive decontamination object that does not dissolve and is bulky can be provided. It can be made easy to handle in blocks,
Or, it can contribute to the storage and management of a large amount even in a narrow site such as a nuclear power plant.

[0017] Further, a transport line for moving the radioactive decontamination target, a cleaning device for the radioactive decontamination target, a radiation dose measuring device for the radioactive decontamination target, and a decontamination for the radioactive decontamination target. If the dyeing apparatus is covered with a shielded room, radiation and radioactive substances are prevented from leaking out of the shielded room as much as possible, and safety is improved from the viewpoint of preventing radiation exposure accidents.

The decontamination device for the radioactive decontamination target may be a decontamination device for decontaminating a part of the radioactive decontamination target, and a decontamination device for a wide area beyond the part of the radioactive decontamination target. If the equipment is equipped with a wide-area decontamination device, the decontamination process should be performed multiple times, especially for parts where the decontamination process should be enhanced, By selecting an appropriate decontamination method suitable for the conditions such as the shape of the object to be decontaminated, thorough decontamination can be strengthened.

Further, the radiation dose measuring device for the radioactive decontamination object is a radiation measuring device for measuring a radiation dose for the radioactive decontamination object at a position on three-dimensional coordinates, and the partial decontamination device comprises: If the apparatus includes a control device that controls the partial decontamination apparatus so as to partially decontaminate the portion of the radioactive decontamination target specified based on the position on the three-dimensional coordinates, partial cleaning is performed. Location, for example, analyze the relationship between the measurement result of radiation dose and the measurement position in three dimensions, specify the measurement position in three dimensions of the part with large radiation dose, and place that specific part in need of partial cleaning By recognizing that, a partial cleaning device can be controlled at that location to reliably perform the partial cleaning.

Further, in the apparatus having a purifying means for purifying the liquid used in the cleaning apparatus or the decontamination apparatus, and a means for supplying the liquid purified by the purifying means to the cleaning apparatus, Since the waste liquid generated in the process can be purified and reused, the amount of waste liquid waste can be reduced.

Further, in the apparatus provided with an ion exchange resin for absorbing and separating radioactive nuclides contained in a liquid as a purifying means, the radioactive waste liquid having a reduced radionuclide content can be reused and the radioactive nuclide can be reused. The amount of waste liquid waste can be reduced.

Further, the transport line on which the radioactive decontamination object moves is a conveyor line for conveying the radioactive decontamination object, and the conveyor line and a horizontal transfer path are vertically overlapped at an end, so that the radioactive decontamination is performed. In the apparatus consisting of an elevating device that hangs and conveys the object, the conveying means of the conveyor line and the elevating device conveys the radioactive decontamination object along a three-dimensional route, and the decontamination device has a decontamination tank. Even if it is adopted, it can be handled by letting the object to be decontaminated into and out of the decontamination tank.

The transport line on which the radioactive decontamination object moves is a conveyor line that conveys the radioactive decontamination object, and the conveyor line and a horizontal transfer path are vertically overlapped at an end, so that the radioactive decontamination is performed. A lifting device for suspending and transporting the object, wherein the conveyor line is routed to the outside and inside of the shielded room; The operation of picking up radioactive decontamination objects from can be performed without being affected by the shielded room.

The decontamination apparatus includes a high-pressure jet water decontamination apparatus, a chemical decontamination apparatus, a blast decontamination apparatus, an electric decontamination apparatus,
In the case of an abrasive sliding decontamination device, a mechanical cutting and decontamination device, or an ultrasonic cleaning decontamination device or a combination of any of them, the decontamination device is used for radioactive decontamination An appropriate decontamination apparatus can be selected or used in accordance with the decontamination conditions and purposes such as the shape, the degree of contamination and the degree of decontamination, and the decontamination work can be performed reliably.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the embodiment of the present invention, a substance conventionally treated as a radioactive solid waste such as a radiation shield generated in a nuclear power plant or other nuclear power plant is decontaminated until it can be reused or treated as a general waste. The purpose is to give

In the following embodiments, objects treated as radioactive solid waste such as radiation shields generated in nuclear power plants and other nuclear power plants will be referred to as radioactive decontamination objects, and each embodiment will be described below. I do.

FIG. 1 is a schematic diagram showing the entire configuration of a decontamination apparatus for a radioactive decontamination object according to a first embodiment of the present invention. In FIG. 1, a building is constructed on a site in a radiation control area of a nuclear power plant. In the building, a shielded room 1 is installed on the floor of the building. The shielded room 1 is made of a material and a structure in which radiation and radioactive substances in the shielded room 1 are hard to leak out of the shielded room 1. A curtain 51 for shielding is hung down at an entrance 52 of the shielded room 1 so that the atmosphere in the shielded room 1, particularly radiation and radioactive substances, is prevented from leaking as much as possible when entering and exiting the shielded room 1. .

Reference numeral 2 denotes a gantry fixed to the floor for setting each apparatus of the decontamination apparatus for radioactive decontamination objects. Reference numeral 3 denotes a belt conveyor horizontally fixed to the gantry 2 for transporting the radioactive decontamination target 5. The conveyor line constituted by the belt conveyor 3 is provided inside and outside the shielding room 1, and the end of the conveyor line protrudes from the entrance 52 of the shielding room 1 to the outside of the shielding room 1. Reference numeral 4 denotes a table which is placed on the belt conveyor 3 and on which the radioactive decontamination object 5 is loaded.

In the middle of the conveyor line shown in FIG. 1, a decontamination tank 21 of the wide-area decontamination apparatus 14 described later is divided into right and left parts in FIG. 1, and separate left and right belt conveyors exist.
A guide rail 53 of an elevating device is installed on the ceiling side of the shielded room 1 in a transport line passing above and below the ends of the left and right belt conveyors and passing above the decontamination tank 21. The traveling drive mechanism of the elevating device 12 is movably combined with the guide rail 53, and the elevating drive mechanism of the elevating device 12 hangs the radioactive decontamination target 5 together with the traveling drive mechanism in FIG.
It is possible to travel along the guide rail 53 as indicated by a solid line from a solid line.

The elevating mechanism of the elevating device is provided with a mechanism 54 for gripping the object to be decontaminated so as to be movable up and down, and observes a lower scene projected on a camera provided in the traveling mechanism outside the shielded room 1. The operation of the operation panel 13 is controlled so that the elevating mechanism can hold the object to be decontaminated while performing the operation. The operation panel 13 controls the operation of the traveling mechanism and the elevating mechanism of the elevating device, and controls the traveling and elevating of the elevating device.

Reference numeral 6 denotes a water receiver for collecting waste liquid generated in a series of operations. The water receiver 6 has an appropriate area in the shielding chamber 1 so as to collect the cleaning liquid dropped from the conveyor line, the table 4 or the radioactive decontamination target 5 during the transfer operation or discharged into the shielding chamber 1. It is arranged with expanse.

In the shielded room, a cleaning device 7, a radiation dose measuring device 8, and a partial decontamination device are sequentially employed along a transport line for the radioactive decontamination target 5 and a thick arrow in FIG. High pressure jet nozzle 9 and multi-axis processing machine 1
1, a wide-area decontamination device 14 and a final cleaning device 15 are arranged.

The cleaning device 7 is provided with a cleaning nozzle directed to hit the object 5 to be decontaminated on the belt conveyor 3. The cleaning liquid is supplied to the cleaning nozzle via the pump 62, the pipe 63, and the valve, and the cleaning liquid can be jetted to the radioactive decontamination target 5. The washing nozzle is preferably provided along a plurality of conveyor lines so that the washing liquid is applied to the object 5 from all directions.

The radiation dose measuring device 8 has a configuration as shown in FIG. That is, there is a measurement box 56 that is guided by the rollers 65 so as to be able to move up and down freely without changing the posture. The measurement box 56 has an open lower surface and a closed other surface. The inner shape of the measurement box 56 is the target 5 for radioactive decontamination.
And has a size that can accommodate the radioactive decontamination target 5 with a slight gap therebetween.

A large number of measuring instruments 57 for measuring the radiation dose in a specific positional relationship are provided on the entire inner surface of the measuring box 56. As the measuring device 57 for measuring the radiation dose, any one of a scintillation detector system, a semiconductor detector system, and a GM tube system is adopted. In this way, the measuring devices 57 for measuring the radiation dose are arranged at three-dimensional positions on the entire inner surface of the measuring box 56.

The arrangement position of each measuring device 57 is stored in the control device 10 as unique position data of three-dimensional coordinates.
Furthermore, the measurement result of each measuring device 57 is
Each measuring instrument 57 is connected to the control device 10 so as to be stored in the control device 10 together with the unique position data of the measurement device 57.

The measuring box 56 is a cylinder device 58 from above.
It is suspended and supported so that it can move up and down freely. Cylinder device 5
The guide 8 and the guide 55 are installed on the ceiling of the shielded room 1 in a vertical position.

9 is a high-pressure jet nozzle device. The jet water ejected from the nozzle of this apparatus is arranged at a position where it reaches the radioactive decontamination target 5 on the belt conveyor 3 with a predetermined force, and is fixed to the shielding chamber 1. A configuration in which the direction of the nozzle of the device can be freely changed under the control of the control device 10 is adopted. The cleaning liquid sent via the pump 62, the pipe 63 and the valve can be supplied to the high-pressure jet nozzle device 9, and the supplied cleaning liquid is made high-pressure without the high-pressure jet nozzle device 9 and is supplied from the nozzle of the device. It is injected.

Reference numeral 11 denotes a multi-axis machine. This multi-axis machine 11 is employed together with the high-pressure jet nozzle device 9 as a partial cleaning device. A polishing desk is mounted on the processing head at the lower end of the multi-axis processing machine 11, and the polishing table is rotated to rotate the polishing desk.
The surface of the radioactive decontamination object 5 can be removed by cutting and polishing the surface of the radioactive decontamination object to remove the radioactive substance that cannot be removed by jet water or washing. Since the multi-axis processing machine 11 has a mechanism capable of moving the processing head, the processing head can be directed to the designated position of the radioactive decontamination target 5 on the belt conveyor 3.

The multi-axis processing machine 11 is designed so that the processing head can be positioned under the control of the control device 10 at the position specified by the position data of the three-dimensional coordinates selected by the control device 10. 11 and the control device 10 are connected.

Reference numeral 14 denotes a wide-area decontamination apparatus. As the wide-area decontamination apparatus 14, an ultrasonic decontamination apparatus, an ultrasonic decontamination and electric release decontamination apparatus, or an abrasive sliding decontamination apparatus can be adopted. The ultrasonic decontamination apparatus is as shown in FIG. 3 and described below. That is, the decontamination liquid 25 dedicated to the decontamination object is heated by passing through the heater 19 from the decontamination liquid tank 18, sucked by the decontamination liquid supply pump 20, and supplied to the 23 inner tanks. The radioactive decontamination target 5 is submerged in the decontamination liquid 25 supplied into the inner tank 23.

The inner tank 23 is set inside the decontamination tank 21 and the pure water 22 is put between the decontamination tank 21 and the inner tank 23 so that the ultrasonic transmitter 26 in the ultrasonic decontamination tank 21 is provided. The ultrasonic wave generated from is transmitted to the decontamination liquid 25 in the inner tank 23, and the radioactive substance adhering to the surface of the cleaning object 24 is separated by cavitation. The cleaning object 24 is the same as the radioactive decontamination object 5.

The radioactive substance peeled off from the surface of the radiological decontamination object 5 is sucked by the pump 29 via the decontamination liquid circulation pipe 61 together with the decontamination liquid 25 and passes through the filter 27. Here, the radioactive substance in the decontamination liquid 25
Is trapped and purified. The purified decontamination liquid 25 is supplied to the inner tank 23 again by the pump 29. During this supply, the valve 60 is closed.

As the decontamination liquid 25, the radioactive decontamination object 5
If there is no problem in dissolving the surface of the surface of the radioactive decontamination target 5 using a solution containing an organic acid or a mineral acid as a main component, use a surfactant or water. use. When the radioactive decontamination target 5 is an electric product, the use of an insulating liquid enables decontamination without damaging the electric circuit.

FIG. 4 shows a radioactive solid waste decontamination apparatus as an example of the wide area decontamination apparatus 14. The ultrasonic decontamination and electric decontamination apparatus shown in FIG. 4 inserts a metal net-shaped positive electrode 31 into the inner tank 23 of the ultrasonic decontamination apparatus shown in FIG. The negative electrode 32 is connected to the conductive radioactive decontamination target 5 in the electrolytic solution 32, and a DC voltage is applied between the negative electrode 31 and the negative electrode 32 by the DC power supply 30. In this way, an electric current flows from the positive electrode 31 to the surface of the conductive radioactive decontamination object 5 using the electrolytic solution 32 as a medium.

In such a decontamination apparatus, when a current flows through the conductive radioactive decontamination target 5, the radioactive substance adhering to the surface of the radioactive decontamination target 5 is dissolved or
By delamination, decontamination is enabled. FIG.
The decontamination device for radioactive solid waste is similar to the ultrasonic decontamination device shown in FIG. 3, and the radiation attached to the surface of the radioactive decontamination target 5 also occurs in the cavitation induced in the inner tank by ultrasonic vibration. The material is stripped off.

Other configurations and operations are the same as those of the ultrasonic decontamination apparatus shown in FIG. The ultrasonic decontamination and electric decontamination apparatus of FIG.
Since the decontamination process by the electrolytic action is performed also on the part where cavitation is not perfect, even if the radioactive decontamination target 5 has a complicated shape, the decontamination process can be spread over a complicated shape. Therefore, the ultrasonic decontamination / electro-decontamination apparatus shown in FIG. 4 is suitable for a decontamination target in which a dissolving solution cannot be used or a radioactive decontamination target 5 having a complicated shape.

FIG. 5 is a schematic view of an abrasive sliding decontamination apparatus (type 1) as an example of the wide area decontamination apparatus 14. As shown in FIG. This example is suitable for a pipe-shaped radioactive decontamination object 5. The abrasive sliding decontamination apparatus (type 1) shown in FIG. 5 is as described below. That is, the heater 35 is attached to the pipe-shaped radioactive decontamination target 5.
Attach and heat. Circulation pipes 70 are attached to both ends of the pipe-shaped radioactive decontamination object 5 in communication with each other. The compressed air pump 36 is connected in the middle of the circulation pipe 70 so that the circulating liquid becomes a gas-liquid mixture. An abrasive 37 and pure water are put into an abrasive mixing tank 33, and the mixed liquid is circulated by a pump 34 into the pipe-shaped radioactive decontamination target 5. At the same time, compressed air is supplied from the compressed air pump 36 to form a gas-liquid mixed liquid. The gas-liquid mixed liquid is supplied to the inner surface of the pipe-shaped radioactive decontamination target 5, and the abrasive 37 slides on the inner surface of the pipe-shaped radioactive decontamination target 5, thereby causing the pipe-shaped radioactive decontamination target 5 to move. The decontamination is enabled by peeling off the radioactive substance attached to the inner surface.

FIG. 6 is a schematic view of an abrasive sliding decontamination apparatus (type 2) as an example of the wide area decontamination apparatus 14. The abrasive sliding decontamination apparatus (type 2) shown in FIG. 6 includes the radioactive decontamination target 5, the abrasive 37, and the decontamination solvent inside the decontamination container 39, and rotates the decontamination container 39 with a rotating roller 38 or a heating roller. By deviating the radioactive substance adhering to the radioactive decontamination object 5 by vibrating or rotating by a shaker, decontamination is enabled.

Each of the above wide-area decontamination apparatuses 14 is selected depending on the decontamination conditions and the state of the radioactive decontamination object 5, and is installed in the middle of the belt conveyor line.

Reference numeral 15 denotes another cleaning device provided in the shielded room 1. The cleaning device 15 includes a cleaning nozzle supported from the ceiling of the shielded room 1. The direction of the cleaning nozzle is oriented so that the cleaning liquid is applied to the radioactive decontamination target 5 on the belt conveyor 3 on the right side of FIG. 1 in a wide range. A cleaning liquid is supplied to the cleaning nozzle via a pump 62, a pipe 63, and a valve, and the cleaning liquid is jetted from the cleaning nozzle toward the radioactive decontamination target 5 on the belt conveyor 3. A water receiver 6 is provided in a wide area covering below the belt conveyor 3 on the right side in FIG.

A suction side of a pump 62 is connected to a drain port of each water receiver 6 in FIG. Even if the decontamination solution of the wide-area decontamination device 14 is mixed with the cleaning solution, if the mixed solution can be reused as the cleaning solution or the decontamination solution, the drainage port of the decontamination solution of the wide-area decontamination device 14 is also pumped. The suction side of 62 is connected by a pipe 63. Although the drainage port of the decontamination liquid of the wide area decontamination apparatus 14 is not shown in FIGS.
A drain outlet may be made from the bottom of the pipe and the pipe 63 may be connected via a valve.

In the middle of the pipe 63, a purifying means is provided downstream of the pump 62. The purifying means is a pipe 6
3 is a filter 16 provided with an ion exchange resin for absorbing and separating radioactive nuclides contained in the liquid sent from the pump 62 side through 3 to purify. Downstream of the filter 16, a pipe 64 for discharging excess liquid is connected to the pipe 63 via a valve.

Hereinafter, a decontamination operation according to an embodiment of the present invention will be described. The radiological decontamination target 5 is assumed to be a radiation shield, piping, or other equipment used in a radiation environment in a nuclear power plant. In this embodiment, the radiation shield is described below as an example. I do.

Since the radiation shield is formed by wrapping an iron plate with a cloth, the cloth and the iron plate are separated. The cloth cannot be reused and must be disposed of as waste. Since the iron plate is separated for reuse, the iron plate is not treated as radioactive waste, but is merely treated as the radioactive decontamination target 5. Hereinafter, the iron plate is referred to as a radioactive decontamination target 5.

The object 5 to be decontaminated taken out of the radiation shield is placed on a table 4, and the table 4 is placed outside the shielding room 1 on the belt conveyor 3 on the left side in FIG. When the belt conveyor 3 is driven by remote control from a location outside the shielded room 1, the radioactive decontamination target 5 passes through the curtain 51 together with the table 4 and enters the shielded room 1.

The cleaning liquid ejected from the cleaning nozzle of the cleaning device 7 in the shielded room is applied to the object 5 to be decontaminated. The radioactive decontamination target 5 that has received the cleaning liquid is washed away of radioactive substances, dust and the like adhering to its surface. After such a cleaning process, the driving of the belt conveyor 3 is continued. Then, finally, the radioactive decontamination target 5 is transported below the radiation measuring device. Here, the driving of the belt conveyor 3 is stopped by remote control.

Thereafter, the cylinder 58 is extended downward by remote control from outside the shielded room, whereby the measuring box 56 is extended.
Descends along the guide 55, and the radioactive decontamination target 5
Cover. Thereafter, the radiation dose is measured by each measuring device 57 in the measuring box 56 by remote control from the control device 10. The measurement result is obtained by the measuring instrument 57 that performed the measurement.
Is stored in the control device 10 together with the position data.

The control device 10 analyzes the position data and the measurement results obtained by the measuring device, and determines the position of the radioactive decontamination object 5 at which position.
It is determined whether or not it is appropriate to add the partial cleaning in advance to the part.
In general, three-dimensional coordinate data of a measuring instrument that has issued a measurement result of a high dose in which the radiation dose exceeds a level that can be decontaminated by the wide area decontamination apparatus 14 is determined, and the position of the determined three-dimensional coordinate data is determined. The part of the radioactive decontamination object 5 close to is subject to partial cleaning.

The control device 10 stores the calculated three-dimensional coordinate data. Thereafter, the cylinder 58 is contracted by the remote control, and the measuring box 57 is returned to the original upper position.

Thereafter, the belt conveyor 3 is driven by remote control, and the radioactive decontamination object 5 reaches the vicinity of the multi-axis processing machine 11 and the high-pressure jet nozzle device 9, where the belt conveyor 3 is again controlled by remote control. Be stopped.

Next, the control device 10 sets the position and orientation of the nozzle of the high-pressure jet nozzle device 9 and the position and orientation of the processing head of the multi-axis processing machine 11 at a position corresponding to the previously determined three-dimensional coordinate data. Control. Thereafter, the portion of the radioactive decontamination target 5 facing the three-dimensional coordinate data is cleaned by remote control by the control device 10 by jet water from the high-pressure jet nozzle device 9 or cutting such as polishing by the multi-axis processing machine 11. Surface. The proper use of the high-pressure jet nozzle device 9 and the multi-axis processing machine 11 is determined by the high-pressure jet nozzle device 9 where the processing head is difficult to reach due to the shape of the radioactive decontamination target 5. This judgment is made by a human and manually switched to be used.

The high-pressure jet nozzle device 9 and the multi-axis processing machine 1
1, after the partial cleaning is completed, the belt conveyor 3 is driven by remote control to control the radioactive decontamination object 5.
Is reached below the left end of the guide rail 53 to stop the belt conveyor 3 by remote control. Next, the lifting device is moved to the left end of the guide rail and stopped by remote control using the operation panel 13. Thereafter, a mechanism 5 for controlling the elevating mechanism by remote control using the operation panel 13 and holding the radioactive decontamination target 5
4 is lowered, and the radiological decontamination target 5 on the table 4 is gripped by the mechanism 54 for gripping the radioactive decontamination target. Then, operation panel 1
The radiological decontamination target 5 is lifted by the remote control by 3 and controlled by the mechanism 54 for gripping the radioactive decontamination target while being separated from the table 4.

Thereafter, the traveling drive mechanism of the elevating device 12 is controlled by remote control using the operation panel 13 to position the radioactive decontamination object 5 above the wide-area decontamination device 14 and the elevating device 12 is stopped. . Next, the elevating mechanism of the elevating device 12 is controlled by remote control by the operation panel 13 to lower the radioactive decontamination target 5 and undergo decontamination processing in the wide area decontamination device 14.

In this embodiment, when the ultrasonic decontamination apparatus shown in FIG. 3 is used as the wide-area decontamination apparatus 14, the operation is as follows. That is, the radioactive decontamination object 5 suspended by the lifting device 12
Is suspended in the inner tank 23 shown in FIG. 3, and the mechanism 54 for once grasping is made to stand by outside the inner tank 23. Thereafter, the decontamination liquid is heated by the heater 19 and put into the inner tank 23 by the pump 20 from the decontamination liquid tank 18.

Thereafter, an ultrasonic wave is transmitted from the ultrasonic wave transmitter 26 into the inner tank 23 to generate cavitation in the decontamination liquid 25 in the inner tank 23 so that the radioactive material is removed from the surface of the radioactive decontamination object 5. And decontamination. Decontamination solution 2 after decontamination
5 is sucked by the pump 29, purified by the filter 27, returned to the inner tank 23 again, and reused.

If necessary, the used decontamination solution 25 in the inner tank 23 is discharged through a pipe 63 through a pipe 63 or is discharged through a filter 16 through a pipe line (not shown). Return to and reuse.

Similarly, when the ultrasonic decontamination and electric decontamination apparatus shown in FIG. 4 is used as the wide-area decontamination apparatus 14, the radioactive decontamination object 5 is placed in the inner tank 23, and the decontamination processing using ultrasonic waves is performed. A decontamination process using electrolysis is added to the radioactive decontamination target 5.

When the abrasive sliding decontamination apparatus shown in FIG. 5 is used as the wide-area decontamination apparatus 14, since the radioactive decontamination target 5 is a pipe, the pipe-shaped radioactive decontamination target 5 is used.
The circulation pipe 70 of FIG. 5 is connected to both ends to perform decontamination processing on the inner surface of the pipe-shaped radioactive decontamination object 5. In this case, since it is not necessary to put the radioactive decontamination target 5 in the decontamination tank, it is not necessary to introduce a lifting device.

When the abrasive sliding decontamination apparatus shown in FIG. 6 is used as the wide-area decontamination apparatus 14, the radioactive decontamination target 5 is placed in a decontamination container 39 containing a decontamination solvent or an abrasive 37. It is suspended using the lifting device 12. Thereafter, the mouth of the decontamination container 39 opened for hanging the container is closed with a lid or the like. Thereafter, the rotating roller 38 is driven to rotate by a motor or the like, and the decontamination container in contact with the rotating roller 38 is rotated. The rotation of the decontamination container 39 in this way causes the radioactive decontamination target 5 in the decontamination container 39 to turn the abrasive 37
5 and radioactive decontamination object 5
The radioactive substance is removed from the surface, and decontamination processing is performed on the radioactive decontamination target 5.

After the decontamination processing by the wide-area decontamination apparatus 14 is performed on the radioactive decontamination target 5, the radioactive decontamination target 5 is gripped and lifted by the gripping mechanism 54 controlled by the operation panel. Thereafter, the elevating device 12 is moved to the right side in FIG. 1 under the control of the operation panel, and is mounted on the belt conveyor 3 on the right side of the wide area decontamination device 14 via the table 4. here,
The radioactive decontamination target 5 is released from the gripping mechanism 54, and the belt conveyor 3 is driven rightward in FIG. 1 by remote control.

When the radiological decontamination target 5 enters the washable area of the cleaning device 15, the cleaning liquid is spouted from the cleaning nozzle of the cleaning device 15 toward the radioactive decontamination target 5 so that the radioactive decontamination target 5 is cleaned. Wash with. By this washing operation, the decontamination liquid, the abrasive and the like are washed away.

Further, the feeding direction of the belt conveyor 3 is shown in FIG.
When the radioactive decontamination object on the table is driven toward the right side of the table, the radioactive decontamination target goes under the curtain 51 and goes out of the shielded room 1.
After the radioactive decontamination target is taken out of the shielded room, the driving of the belt conveyor 3 is stopped, and a series of washing and decontamination operations are completed. The radioactive decontamination target 5 that has been taken out of the shielded room 1 is in a state where there is no radiation dose,
Is transported to the place where the work to rebuild the decontaminated material on the shield is performed.

When there is no radiation dose after the cleaning and decontamination of the radioactive decontamination object 5, since the radioactive decontamination object 5 has no radiation, it can no longer be treated as a general iron plate. Even if iron plates are discarded, they can be discarded as general iron waste materials. As a result, the amount of radioactive solid waste is reduced, and the amount of drum tubes for storing them and the amount of work are reduced.

Cleaning devices 7 and 15 and high-pressure jet nozzle 9
The liquid ejected to the radiological decontamination target 5 from the wastewater is collected in the water receiver 6, pumped to the filter 16 by the pump 62 for purification, and then cleaned through the pipe 63 through the cleaning devices 7 and 15 and the high-pressure jet nozzle 9. And re-use. The decontamination liquid of the wide area decontamination device 14 is similarly reused as needed. Such reuse reduces the amount of radioactive liquid waste.

In the above operation, the shielding room 1 is
Radiation leakage to the outside and leakage of radioactive substances are reduced as much as possible, and deterioration of the environment inside the building where the shielded room 1 is placed is suppressed to reduce radiation exposure. In the above operation, an image is captured by the video camera 75 in the shielded room 1 and visually monitored as an image on a monitor outside the shielded room 1. Video camera 7
Although only one unit 5 is shown in FIG. 1, a plurality of units 5 may be provided in a shielded room as needed to enhance monitoring accuracy.

In the embodiment shown in FIG. 8, the cleaning device 15 of the previous embodiment is deleted, a radiation dose measuring device 71 is provided at the position of the cleaning device 15, and the radiation dose measuring device 71 is provided in the control device 10.
It is connected so that the measurement result of can be displayed.

In the embodiment shown in FIG. 8, the radiation dose is measured by the radiation dosimeter 71 for the radioactive decontamination object 5 which has been decontaminated by the wide area decontamination apparatus 14, and the decontamination result is controlled by the control unit 10 After confirming the above, the radioactive decontamination target 5 can be taken out of the shielded room 1. Other configurations and operations are the same as those in the previous embodiment.

The embodiment of FIG. 2 is a modification of the embodiment of FIG. 1, and the contents of the modification are as follows. That is, FIG.
The cleaning device 15 of the embodiment is deleted, and the dissolution tank 17 is placed at the position of the cleaning device 15. On the other hand, a radiation dosimeter 71 is provided in place of the cleaning device 15 of FIG. 1, and is connected to the control device 10 so that the measurement result of the radiation dosimeter 71 can be displayed.

In such an embodiment, the wide-area decontamination device 14
, The radiation dose is measured by a radiation dosimeter 71 for the radioactive decontamination object 5, and the decontamination result is confirmed by the control device 10. As a result of the confirmation, when the radiation dose is equal to or higher than the target level, the radioactive decontamination target 5 is lifted again by the elevating device 12, and the dissolving tank 17 is positioned below the belt 5 by the reverse rotation of the belt conveyor 3. Thereafter, the object 5 to be decontaminated is suspended in the dissolving tank 17 and the dissolving tank 17 is moved to the right end of the shielding room by driving the belt conveyor 3.
The radioactive decontamination target 5 is dissolved in the dissolving tank 17 to form a block 73. The block is taken out of the shielded room 1 and is used and stored in the nuclear power plant where the shielded room 1 is installed. At the time of storage, the volume required for storage can be reduced because it is blocked. Other configurations and operations are the same as those of the embodiment of FIG. In FIG. 2, the cleaning device 15 may be used instead of the radiation measuring device 71 to enhance the cleaning.

Of course, the cleaning device 15, the radiation dosimeter 71, and the dissolving tank 17 may be arranged in the shielded chamber 1 in whole or in any combination. Further, in any of the embodiments, the transfer line by the belt conveyor 3 may be replaced by a transfer line formed by a combination of a rail and a carriage driven along the rail. In any of the embodiments, the high-pressure jet nozzle 9 and the multi-axis processing machine 11 are replaced with any one of the decontamination apparatuses shown in FIGS. Whether to adopt a staining device or to combine a plurality of decontamination devices may be determined in consideration of various conditions such as the degree of contamination and the shape of the radioactive decontamination target 5.

According to such a series of washing and decontamination work,
The following effects can be obtained. That is, the conventional man-made operation of radioactive solid waste treatment can be mechanically and remotely performed, and the work efficiency and the exposure of the engaged workers can be completely eliminated.

Furthermore, by enabling radioactive solid waste to be a non-radioactive decontamination object, each nuclear power plant can be used for the year reported in the annual nuclear power plant operation management annual report. Of drums containing radioactive solid waste generated and stored in the country
It is possible to greatly reduce the amount of stored radioactive solid waste at 0 plants / power plant.

By changing the specifications, arrangement, and structure of cleaning / dose measurement / processing, operations including decontamination can be performed.
It is possible to improve the decontamination efficiency.

Further, by synchronizing the shape and size with the dose and the contamination value of the radioactive waste, the decontamination based on the control data can be expected to greatly improve the work.

[0086]

According to the present invention, a series of operations from cleaning to decontamination can be made into a line to easily reduce the amount of radioactive solid waste.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a decontamination apparatus for a radioactive decontamination object.

FIG. 2 is an overall configuration diagram when a melting furnace is employed in the apparatus of FIG.

FIG. 3 is an overall configuration diagram of an ultrasonic cleaning apparatus adopted as the wide-area decontamination apparatus in FIG. 1;

FIG. 4 is an overall configuration diagram of an ultrasonic electro-release dyeing apparatus adopted as the wide-area decontamination apparatus in FIG. 1;

5 is an overall configuration diagram of an abrasive sliding decontamination apparatus (type 1) employed as the wide-area decontamination apparatus of FIG. 1;

6 is an overall configuration diagram of an abrasive sliding decontamination apparatus (type 2) employed as the wide-area decontamination apparatus of FIG. 1;

FIG. 7 is an overall configuration diagram of the radiation dose measuring device of FIG. 1;

FIG. 8 is an overall configuration diagram of an embodiment in which the cleaning device of FIG. 1 is replaced with a radiation measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Shield room, 3 ... Conveyor belt, 5 ... Radioactive decontamination object, 7, 15 ... Cleaning device, 8 ... Radiation dose measuring device, 9
... High-pressure jet nozzle, 10 ... Control device, 11 ... Multi-axis processing machine, 12 ... Elevating device, 13 ... Operation panel, 14 ... Wide area decontamination device, 16 ... Filter, 17 ... Dissolution tank.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Hiroshi Hoshi 3-2-2, Sachimachi, Hitachi, Ibaraki Prefecture Within Hitachi Engineering Services Co., Ltd. (72) Akira Mizuochi 3-2-2, Sachimachi, Hitachi, Ibaraki No. 2 Within Hitachi Engineering Services Co., Ltd. (72) Inventor Shoji Nagayama 3-2-2, Sachimachi, Hitachi City, Ibaraki Prefecture Within Hitachi Engineering Services Co., Ltd.

Claims (11)

[Claims] 1. A cleaning device for a radioactive decontamination target, a radiation dose measuring device for the radioactive decontamination target, a decontamination device for the radioactive decontamination target, and a cleaning device for the radioactive decontamination target Decontamination equipment for radioactive decontamination objects, comprising: a radiation line measuring device; 2. The decontamination function according to claim 1, wherein the decontamination device is subjected to decontamination by another cleaning device for cleaning the radioactive decontamination object after decontamination by the decontamination device along the transport line. A decontamination facility for a radioactive decontamination target, comprising at least one of other radiation dose measuring devices for the radioactive decontamination target later. 3. The radiological decontamination object according to claim 1, further comprising means for receiving and dissolving the radioactive decontamination object after decontamination by the decontamination device along the transport line. Decontamination equipment. 4. The radioactive decontamination target according to claim 1, wherein the radioactive decontamination target is moved, a transport line that moves the radioactive decontamination target, a cleaning device for the radioactive decontamination target, and a radiation for the radioactive decontamination target. A decontamination facility for a radioactive decontamination object in which a quantity measuring device and a decontamination device for the radioactive decontamination object are covered by a shielded room. 5. The decontamination apparatus according to claim 1, 2 or 3 or 4, wherein the decontamination apparatus for the radioactive decontamination object performs partial decontamination processing for performing decontamination processing on a part of the radioactive decontamination object. A decontamination facility for a radioactive decontamination object, comprising: a decontamination device; and a wide-area decontamination device for decontaminating a wide area beyond a part of the radioactive decontamination object. 6. The radiation measuring apparatus according to claim 5, wherein the radiation dose measuring device for the radioactive decontamination target is a radiation measuring device for measuring a radiation dose for the radioactive decontamination target at a position on three-dimensional coordinates. The decontamination device includes a control device that controls the partial decontamination device so as to partially decontaminate a part of the radioactive decontamination target specified based on the position on the three-dimensional coordinates. Equipment for decontamination of goods. 7. The cleaning device according to claim 1, wherein the cleaning device or the decontamination device purifies the liquid used in the cleaning device or the cleaning device. Decontamination equipment for radioactive decontamination objects, comprising: a supply means. 8. A facility for decontamination of a radioactive decontamination object according to claim 7, comprising an ion exchange resin for absorbing and separating radionuclides contained in the liquid as a purification means. 9. The transportation line according to claim 1, wherein the object to be decontaminated is moved,
A radioactive decontamination target comprising a conveyor line for transporting the radioactive decontamination target, and a lifting / lowering device for suspending and transporting the radioactive decontamination target, wherein the conveyor line and a horizontal transfer path are vertically overlapped at an end. Decontamination equipment. 10. The conveyor line according to claim 4, wherein the transport line on which the radioactive decontamination target moves is a conveyor line for conveying the radioactive decontamination target, and the conveyor line and a horizontal transfer path are vertically overlapped at an end. And a lifting device for suspending and transporting the radioactive decontamination object, and wherein the conveyor line is routed to outside and inside the shielded room. 11. The decontamination apparatus according to any one of claims 1 to 10, wherein the decontamination apparatus is a high-pressure jet water decontamination apparatus.
Radiation composed of chemical decontamination equipment, blast decontamination equipment, electro-decontamination equipment, abrasive sliding decontamination equipment, mechanical cutting and decontamination equipment, ultrasonic cleaning decontamination equipment or any combination of them Decontamination equipment for decontamination targets.