JPS59216100A - Decontamination device for equipment contaminated with radioactivity - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a decontamination device for various equipment, containers, or piping (hereinafter referred to simply as nuclear equipment) contaminated with radioactivity.

[Technical Background of the Invention] Nuclear power plants in operation and nuclear equipment such as experimental equipment are contaminated with radioactivity, and the level of contamination increases with frequency of use, so they must be decontaminated. Also,
Due to domestic laws and regulations specific to nuclear reactors, inspections (regular inspections) of these nuclear power equipment are also becoming stricter.

In line with these trends, there is a desire to develop a more reliable decontamination method for the atomic saw type equipment.

As one of the conventional decontamination methods for radioactive contamination, a surface treatment device using sand grains, ie, a sandblasting device, the basic configuration of which is shown in FIG. 1, is known.

That is, in FIG. 1, sand grains are injected from a honing gun 2 onto an object to be decontaminated 1 together with high-pressure air, thereby cleaning the contaminated surface of the object to be decontaminated. Here, the object to be decontaminated 1 and the honing gun 2 are arranged in a hood 3, and the hood 3 has a recovery pipe 3a connected to a blower 4, and a supply pipe 6a from a storage tank 6 connected to a sand particle production device 5. and a pressure air supply pipe 9 from a high pressure air source 7 are connected. Further, a bypass pipe 8a that connects to a waste treatment device 8 is connected to a pipe 4a that connects the blower 4 and the storage tank 6.

By the way, the sand grains are manufactured by adjusting the particle size etc. in the manufacturing device 5 and are transferred to the storage tank 6. High-pressure air sent from a high-pressure air source 7 flows below the storage tank 6, and the high-pressure air applies an ejection pressure horn to the sand grains, and the sand grains are guided to the honing gun 2 through the supply pipe 6a. Since high-pressure air is flowing through the honing gun 2 through the pipe 9, the sand grains are further energized with ejection pressure, and the honing gun 2
The sand grains are ejected directly onto the contaminated surface of the object 1 to be decontaminated at high speed, and the contaminated surface is purified and surface-treated by the impact force upon impact. The sand grains that have fallen after impacting the contaminated surface are collected in the hood 3 and transferred to the storage tank 6 via the floor 4 through the collection pipe 3a. Then, it is either reused or transferred to the waste treatment device 8 through the bypass piping 8a and disposed of.

"Problems with the Background Art" However, the above-mentioned surface treatment apparatus has a fairly sufficient effect on pre-treatment for painting or surface treatment for finishing the surface into a glossy surface.

However, when this device is used for nuclear power equipment, the abrasive power of the sand grains is large, causing damage to the equipment surface.
This results in polishing not only the deposited cladding but also the surface of the equipment.

Therefore, it has the drawback that it cannot necessarily be said to be an appropriate device when it comes to reusing nuclear reactor equipment and reducing secondary waste.

[Purpose of the Invention] The present invention has been made to eliminate the above-mentioned drawbacks, and it can be expected to have a sufficient decontamination effect when processing miscellaneous solid waste, decontaminating equipment and tools in use, and has a secondary The purpose of the present invention is to provide a device for removing equipment contaminated with radioactivity, which reduces waste, can be operated continuously, and can dispose of human waste in a short time.

[Approximate number of inventions] That is, the present invention applies ejection pressure to glass particles and injects them onto a contaminated surface to remove radioactive substances attached to nuclear equipment, such as metal surfaces, and uses the impact force when the glass particles collide. Decontamination of the contaminated surface 1- A device for decontaminating equipment contaminated with radioactivity, including a high-pressure air source that applies ejection pressure to glass particles, and glass particles to which ejection pressure is applied from this high-pressure air source. A honing gun ejects glass particles toward the contaminated surface of the object to be decontaminated, and glass particles ejected from the honing gun and impacting the surface of the object to be decontaminated are transferred to the decontamination cladding and the regenerating gas.
An electromagnetic separation device that separates the glass particles into glass particles, and a hole 1- that compresses the recycled glass particles separated by this electromagnetic separation device.
This is a decontamination device for equipment contaminated with radioactivity, which is characterized by consisting of a press device.

According to the present invention, since glass grains have a low density, only the cladding attached to the surface of nuclear equipment can be separated without polishing the metal surface, making it possible to reuse nuclear equipment. In addition, glass particles and cladding generated as secondary waste can be used to produce glass assimilates without mixing different materials, so secondary waste m can be reduced. Furthermore, the glass particles used as the decontamination material are soda lime glass, which is the most common and inexpensive, or borosilicate glass, which is chemically resistant. °C, borosilicate glass: 1
It is easy to produce glass assimilates in the form of pellets by heating at a temperature of 000°C to 1200°C and compressing at high pressure.

[Embodiment of the Invention] Hereinafter, an embodiment of the apparatus according to the present invention will be described with reference to FIG. Note that the same parts in FIG. 2 as in FIG. 1 are designated by the same reference numerals.

In FIG. 2, the object to be decontaminated 1 and the honing gun 2 are placed inside a hood 3. High-pressure air flows into the honing gun 2 from a high-pressure air source 7 through a high-pressure pipe 9, and glass particles 11 in a fluidized bed 10 are supplied through a supply pipe 12.

A dispersion plate 13 is disposed below the fluidized bed 10, and glass particles are supplied from a supply device 14 containing the glass particles onto the dispersion plate 13 in the fluidized bed 10 through a pipe 16.

Further, some of the glass particles in the supply device 14 are transferred to the branch pipe 15.
It is also supplied to the honing gun 2 from there. A discharge pipe 17 for discharging glass particles for regenerating glass particles is connected to the upper end of the fluidized bed 10, and the discharge pipe 17 is connected to a cyclone separator 18. The upper part of the dicyclone reparator 18 is connected to a gas processing device 20 via a pipe 19.

The downstream side of the gas treatment device 20 is connected to an air supply device 23 through a piping 21 . The air supply device 23 is connected to the fluidized bed 1
An air supply pipe 24 for flowing gas into the glass particles 11 and stirring the glass particles 11 is connected thereto.

On the other hand, the lower part of the cyclone roberator 18 is connected to the hollow 1 to the press device 25 by a pipe 22, and the cladding and fine powder of glass particles sent from the cyclone separator 18 are molded into an assimilated body by the hot press device 25. .

Also, a pipe 2 connected from the vicinity of the distribution plate 13 of the fluidized bed 10
6 is connected to an electromagnetic separation device 28 via a valve 27. The electromagnetic separator @28 is a device that separates glass particles and cladding using electromagnetic force, and below it is the pipe 1.
9 to the hot press device 25, the upper part of which is connected to the supply side of the fluidized bed 10 via piping 30, and the glass particles discharged from the hood 3 are supplied to the electromagnetic separation device 28 through piping 3a. A system has been established to do this. Furthermore, a radiation detector 31 is arranged on the side surface of the fluidized bed 10.

Here, the exhaust gas that has passed through the cyclone separator 18 is
It is treated in the exhaust gas treatment device 20 and returned to the air supply device 23 through the distribution @21.

On the other hand, the glass particles and cladding collected in hood 3 are
The glass particles are introduced into the electromagnetic separation device 28 through the pipe 3a, the glass particles are returned to the fluidized bed 10 through the pipe 30, and the cladding is introduced into the hot press device 25. The hot press device 25 is provided with a pipe 22 that introduces the cladding and fine glass particles discharged from the cyclone lever.

Next, the operation of the device having the above configuration will be explained. The glass particles sent from the supply device 14 are transferred from the pipe 16 to the fluidized bed 10.
A predetermined amount of air is supplied from the air supply device 23 to a predetermined amount to flow the glass particles. Next, the glass particles are supplied from the supply device 14 to the honing gun 2 via the piping 15, and a jetting pressure is applied from the high-pressure air source 7 through the piping 9, and the glass particles are jetted toward the decontamination surface 1, causing the glass particles to collide. The impact force at the time separates the crud adhering to the surface of the decontamination surface 1 and decontaminates it. The glass particles and cladding are collected in the hood 3 and transferred to the solenoid valve all device 28 through the piping 3a. In the electromagnetic force 1 ml device 28, electromagnetic action works to remove iron oxide (Fe z03/Fe30q), which is a component of the cladding.
) The α-hematite and magnetite with magnetic properties are attracted by the electromagnetic force + mi & the magnetic field created by the device 28,
The amorphous iron oxide, which is a non-magnetic material, passes through the electromagnetic separator 28 together with the glass particles without being attracted by the magnetic field, and is returned to the fluidized bed 10 via the piping 30. Since the cladding is mostly α-hematite and magnetite, a small amount of amorphous iron oxide is returned to the fluidized bed 10.

In the fluidized bed 1o, the glass particles supplied in advance are mixed with the glass particles that have passed through the electromagnetic separator 28, and the cladding attached to the glass particles collides with the glass particles. It is peeled off and removed. The peeled cladding has a glass particle density of 2.
．． Since the particle size is 7 to 8 (]/CI/ compared to 5 g/Li, the glass particles stay below the fluidized bed 10 while flowing above the fluidized bed 10. Decontamination of the metal surface is carried out continuously. Therefore, used glass particles are separated by electromagnetic separation device 2.
8 , the volume of glass particles in the fluidized bed 10 increases, overflows into the pipe 12 , and is introduced into the honing gun 2 . Here, the supply of glass particles from the supply device 14 to the honing gun 2 is stopped, and the used glass particles overflowing from the fluidized bed are
Decontaminate surface 1. The used glass particles are placed in a fluidized bed 10
Since the cladding is decontaminated inside, there is no need to worry about re-contamination of the decontaminated surface 1.

On the other hand, fine powder of glass and cladding accompanying the air rising in the fluidized bed 10 passes through a pipe 17 and is collected in a cyclone separator 18, and then passes through a pipe 22 to a hot press device 2.
Sent to 0. And exhaust gas is exhaust gas station 3! I! Attachment@2
0, and is returned to the air supply device 23 via the piping 21 and reused.

Since the decontamination of the decontamination surface 1 is performed in continuous operation, crud (amorphous iron oxide) that is not sucked into the electromagnetic separator 28 accumulates in the fluidized bed 10 . The accumulated amount of crud (amorphous iron oxide) is determined by measuring the radioactivity with a radiation detector 31 installed below the fluidized bed 10, and when the radioactivity exceeds a predetermined value, the valve 27 is intermittently turned on and the radioactivity is removed.
Piping 26 removes the cladding and glass particles accumulated below the
The liquid is discharged to an electromagnetic separator 28 via a radiator and introduced into a hot press device 25. Also, electromagnetic force I! 1, the Kamaishi cladding (α-hematite, magnetite) is also attracted to the device 28, and the electromagnetic force is attenuated. Then stop continuous operation,
The cladding and glass particles are removed from the electromagnetic separation device 28 and introduced into the hot press device 25.

The hot press device 25 contains glass particles of 80% to 50%.
%, the cladding was introduced at a rate of 20% to 50%, and the degree of dryness (soda lime glass: 800 ° C to 1
000℃, borosilicate lath: 1000℃~1200℃
) and compressed under high pressure to produce a pellet-like vitrified material.

On the other hand, since some of the glass particles in the fluidized bed 10 are introduced into the pot press device 25, the amount of glass particles in the fluidized bed 10 is reduced. Therefore, the amount of glass particles may be increased as needed by supplying it from the supply device 14 to the honing gun 2 via the pipe 15 or to the fluidized bed 10 via the pipe 16.

The gist of the present invention is to provide equipment contaminated with radioactivity that applies spray pressure to glass particles and injects them onto a surface to be decontaminated, and decontaminates the surface to be decontaminated using the impact force generated when the glass particles collide. A decontamination device for equipment contaminated with radioactivity, which is characterized by removing crud attached to used glass particles and converting the separated crud and contaminated glass particles into a glass assimilate. .

Further, embodiments of the present invention include (1) using a fluidized bed as a means for removing crud attached to used glass particles;
(2) Installing an electromagnetic fractionation device that uses electromagnetic force to separate used glass particles and cladding; (3)
) A pot press device was installed as a device for transferring the cladding and contaminated glass into a glass assimilate; (4) the fluidized bed was equipped with a glass grain supply device, a cyclone senogrator, an exhaust gas treatment device, an air supply device, (5) The fluidized bed has a glass grain supply port and an exhaust gas outlet at the upper end, a glass grain supply port, a supply port from the electromagnetic separation device, and a drain port at the lower end. It is equipped with a dispersion plate and an air supply port.

[Effects of the Invention] As explained above, according to the present invention, crud attached to used glass particles is removed using a fluidized bed and a solenoid valve M device.
1i, it can be reused as a decontamination method without causing recontamination of the decontaminated surface, and has the effect of reducing secondary waste. Furthermore, glass particles and cladding generated as waste can be used to produce a vitrified product that is extremely stable as an assimilate at a temperature below the melting temperature of glass by using a hot press device.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional device, and FIG. 2 is a system diagram showing an embodiment of the decontamination device for equipment contaminated with radioactivity according to the present invention. 1... Decontamination surface 2... Honing gun 3...
......Hood 7...High pressure air source 10...
......Fluidized bed 13...Dispersion plate 14...Feeding device 18...
・・・・・・Cyclone separator 20・・・・・・
...Exhaust gas treatment device 23...
... Air supply device 25 ...... Pot press device 28 ...... Electromagnetic separation device 31
......Radioactivity detector Figure 1 Figure O, 3-57:

Claims (1)

[Claims] (1) A high-pressure air source that applies ejection pressure to glass particles, a honing gun that ejects glass particles to which ejection pressure has been applied from the high-pressure air source toward the contaminated surface of the object to be decontaminated, and from this honing gun An electromagnetic separation device that separates the glass particles that have ejected and impacted the surface of the object to be decontaminated into decontaminated cladding and recycled glass particles, and a hot press device that compresses the recycled glass particles separated by this electromagnetic separation device. A decontamination device for equipment contaminated with radioactivity, characterized by comprising: