JP2014160065A - Decontamination system using high pressure cleaning, and decontamination method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decontamination system suitable for decontamination at a radioactive material contaminated site and purifying contaminated water after decontamination to produce reusable cleaning water, and a decontamination method.SOLUTION: A decontamination system force-feeds cleaning water from a tank 1 by a high-pressure cleaning machine 3 and jets the cleaning water from a nozzle via a water supply hose 5, recovers contaminated water after cleaning by the cleaning water jetted from the nozzle with a vacuum tank 7 as a negative pressure by a suction hose 9, and purifies and normalizes the recovered contaminated water by a turbid water treatment device 11 to reuse the resultant water. Pressure adjustment can be performed so that the dispersion of cleaning water jetted from the nozzle and contaminated water after cleaning in a closed space, to which a nozzle connection end and a suction port end of the water supply hose are connected, to the outside is intercepted and so that the discharge pressure of cleaning water jetted from the nozzle maintains predetermined pressure balancing such that predetermined cleaning force is not attenuated by the suction force of the negative pressure.

Description

  The present invention relates to a decontamination system and a decontamination method using high-pressure cleaning, and more specifically, a decontamination system and decontamination for cleaning a radioactively contaminated workpiece and a cleaning object such as a road using high-pressure cleaning. It is about the method.

  Conventionally, many decontamination devices and decontamination methods have been proposed for decontamination against radiation contamination in facilities and components in a nuclear power plant building. For example, a device for decontaminating a floor surface in a nuclear power plant building, as an alternative to the wiping of a worker's waste, a plurality of brushes that rotate to take contaminated water into the center line of the vehicle body, There has been proposed a floor surface decontamination device including a water discharge device that discharges water in the vicinity and a suction device that sucks sewage taken in by the brush (see Patent Document 1). According to this floor surface decontamination apparatus, not only cleaning but also collecting sewage makes it possible to prevent diffusion of contaminated parts.

In addition, multiple discharge nozzles that place decontamination objects in contact with the reactor water at the nuclear power plant and place radioactive substances on the surface of the parts on a stand in the washing tank, and perform bubbling and high-pressure water injection in the washing tank. As a high-pressure water discharged from the discharge nozzle, the radioactive material removed is settled at the bottom of the cleaning tank, separated by a filter incorporated in a shielded drum, and the outlet water is transferred by a pump. A decontamination apparatus having a supply valve has been proposed (see Patent Document 2). According to this decontamination apparatus, the contaminated water after washing can be filtered and reused as washing water, and the waste waste liquid can be greatly reduced.

  Furthermore, the floor surface decontamination device is composed of a device body and a washing machine that are connected by a flexible suction hose and a water absorption hose. And a floor surface decontamination apparatus provided with a cleaning water spray port, a cleaning brush or pad rotated by a motor, and a squeegee has been proposed (see Patent Document 3). According to this floor surface decontamination device, the floor surface can be decontaminated cleanly by a relatively simple operation, and even on a floor surface with unevenness or steps, it can be reliably washed and decontaminated, It was possible to prevent radioactive substances from being scattered by washing, to reduce the dose equivalent of decontamination work, and to filter the released air with a hepa filter effectively with reduced pressure loss.

  By the way, the TEPCO Fukushima Daiichi nuclear power plant is in operation due to the so-called Tohoku-Pacific Ocean Earthquake that occurred on March 11, 2011 (so-called Great East Japan Earthquake). Dose of radioactive contamination has occurred. There are many places where radioactive contamination occurs, and there are many situations where appropriate decontamination cannot be performed with decontamination equipment and decontamination methods specialized for decontamination of nuclear buildings as before.

Therefore, a decontamination apparatus that can cope with decontamination in a so-called urban area outside a nuclear power plant has been proposed. For example, spraying or spraying cleaning water containing surfactant, inorganic acid potassium salt or ammonium salt, and fulvic acid on the object to be decontaminated, and washing, spraying or watering the object to be decontaminated and cleaning A step of recovering the washed waste water, a step of coagulating and precipitating radioactive substances contained in the washing waste water, a step of separating the coagulated sediment, and a step of storing the separated coagulated sediment in a storage container. The decontamination apparatus which has is proposed (refer patent document 4). Furthermore, a water discharge unit having a water discharge nozzle for discharging the cleaning water to the decontamination target, a recovery unit having a recovery nozzle for recovering the wash water discharged to the decontamination target, and the recovered wash water Agglomeration and sedimentation part for agglomerating and precipitating radioactive substances contained in the liquid, solid-liquid separation part for solid-liquid separation of the agglomerated sediments of the radioactive substance, and dissolved radioactive substances contained in the solid-liquid separated washing wastewater are adsorbed to the adsorbent There has been proposed a decontamination apparatus having an adsorbing part (see Patent Document 5).

  The Ministry of the Environment stated, “Article 40 of the Special Measures Law concerning the treatment of environmental pollution caused by radioactive materials released by the accident at the nuclear power plant accompanying the Tohoku-Pacific Ocean Earthquake that occurred on March 11, 2013 “Part 2 Guidelines for Decontamination Measures” (hereinafter referred to as “Part 2 Decontamination Measures”) that specifically explains the Ordinance of the Ministry of the Environment regarding the standards for measures such as decontamination of soil, etc. "Guidelines") explains the decontamination method. According to the guidelines, for decontamination of pavement surfaces, etc., when performing high-pressure washing, wash from the periphery to the inside and from the high ground to the lower direction so that the water does not splash around, and the route through which the washing water flows is pre- In order to ensure that the drainage route is cleaned in advance and that smooth wastewater can be discharged, and to prevent scattering of soil, etc. due to water pressure, first wash at low pressure to check the flow and state of the wash water. While confirming, it is described that the pressure is gradually increased to perform cleaning (see Non-Patent Document 1).

JP-A 63-200731 JP 2002-31193 A JP 2002-31192 A Japanese Patent No. 5277481 Utility Model Registration No. 3187159

“Part 2 Guidelines for Decontamination Measures” December 2011, 1st edition, Ministry of the Environment, III Road decontamination measures, etc. Decontamination method (2) Decontamination of pavement surfaces (mainly cleaning), pages 2-46 to 2-48

  The inventions described in Patent Documents 1 to 3 are based on the premise of decontamination inside a nuclear power plant building, and are not necessarily suitable for decontamination of the decontamination target indicated in the guidelines. . For example, in the invention described in Patent Document 1, the cleaning water hole is formed at the center of a circular brush, but the suction port is provided at a position away from the cleaning water hole behind the brush. For this reason, there is a possibility that the scattering and outflow of contaminated water cannot be completely prevented.

  Also, unlike the case where the decontamination target area is in a narrow range, such as in a nuclear power plant building, decontamination in urban areas is not only wide, but also the supply of cleaning water to be used is not always sufficient. . Decontamination while carrying a large amount of washing water also causes cost problems. Therefore, it is conceivable to purify the collected contaminated water and reuse it. However, in the invention described in Patent Document 2, the waste liquid precipitated by putting the object to be contaminated into the wash water and performing bubbling and high-pressure water injection. In this configuration, the outlet water is separated by a filter and the outlet water is reused, which is not suitable for decontamination of urban areas.

  Further, in the invention described in Patent Document 3, a spray port for cleaning water and a suction port for contaminated water are provided in the vicinity, and a separation and recovery device for separating radioactive substances from the contaminated water is also provided. A sufficient effect can be obtained even if the radioactive material adhering to the earth and sand solidified in the small voids on the pavement surface is cleaned with a device for decontamination of the floor in the nuclear power plant building. It is not considered. That is, in order to suck these earth and sand, a suction force larger than that for sucking the contaminated water on the contaminated surface in the building is required. However, if the suction force is simply increased, the cleaning water is ejected from the nozzle. The discharge force is attenuated, and a sufficient cleaning effect cannot be obtained. On the other hand, if the discharge force is excessively increased, the road surface display paint or the like may be washed away and the pavement surface or the like may be damaged. In order to solve such problems, there may be a method of adjusting the traveling speed of the cleaning machine according to the condition of the object to be cleaned.However, work efficiency is reduced and traveling speed adjustment requires appropriate experience. Therefore, there is a disadvantage that the cleaning effect varies depending on the operator. In addition, the separation and recovery device specializes in gas-liquid separation and recovery, but as described above, in urban areas, it is necessary to purify contaminated water containing earth and sand to which radioactive substances are attached. You cannot get reusable water.

Furthermore, in the invention described in Patent Document 4, cleaning water containing fulvic acid, potassium salt or ammonium salt of inorganic acid and a surfactant is used, but these cleaning waters are compared with so-called normal natural water. In addition, the running cost is high, and the rinsing process after cleaning is indispensable in actual work, and the work efficiency is poor. In a general parking lot in an urban area with a dose equivalent of 0.35 μSv before decontamination, the above-mentioned patent is applied to a high-pressure washing machine with a discharge pressure of 15 MPa, a motor output of 3.6 kW, a vacuum pressure of 230 hPa, and a motor output of 1.3 kW. When the cleaning water according to the invention described in Document 4 is used, the dose equivalent after decontamination is 0.28 μSv (decontamination rate is about 20%). When natural water is used, the dose equivalent after decontamination is used. Was 0.31 μSv (decontamination rate was about 11.4%). Therefore, it was confirmed that the decontamination effect of the washing water was higher than that of natural water. However, after the decontamination in the case of using the washing water according to the invention described in Patent Document 4 with a high pressure washer having a discharge pressure of 15 Mpa, a motor output of 5.5 kW, and a vacuum unit of 50 kPa and a vacuum output of 6.3 kW, The dose equivalent and the dose equivalent when natural water was used were the same at 0.19 μSv (decontamination rate 45.7%). That is, it was clear that the decontamination effect was not different between cleaning water containing fulvic acid and natural water by increasing the vacuum pressure. In addition, when the motor output of the high pressure washer is 3.6 kW, continuous use for 2 hours or more at the maximum discharge pressure may cause overheating. After continuous operation within 2 hours, pause for about 1 hour. It was necessary to intervene. In addition, some local governments, including areas that were subject to decontamination in ordinary homes due to the Tohoku Pacific Ocean Earthquake, have set a vacuum maximum vacuum pressure of 4,500 mmAq or more in the decontamination specifications. It is said that there is. Therefore, in the future decontamination work, decontamination by high vacuum pressure is standardized, and under such conditions, a low-cost, high-efficiency decontamination system is required. In addition, although the structure of patent document 5 includes the structure which decontaminates with the washing water which does not contain the said washing | cleaning agent, the solution means with respect to the bad effect accompanying the increase of the said suction force and discharge force is not clarified. .

  Then, in view of the said problem, this invention is suitable for the decontamination in the urban area contaminated with the radioactive material, and it aims at providing the low-cost and highly efficient decontamination system and decontamination method.

  A decontamination system according to the present invention is a decontamination system by high-pressure cleaning for a radiation-contaminated workpiece and an object to be cleaned such as a road, and the cleaning water is stored at a high pressure from the storage means. A pressure feeding means, a discharge means for jetting the high pressure pumped wash water from a nozzle through a water supply hose, and a contamination after being washed by the wash water jetted from the discharge means with a vacuum tank in a negative pressure state Recovery means for recovering water via a suction hose, turbid water treatment means for purifying or conditioning the recovered contaminated water, drive means for driving the pressure feeding means and recovery means, and nozzle of the water supply hose The connection end and the suction port end of the suction hose are connected, and a closed space is formed between the cleaning surface of the object to be cleaned and the nozzle connection end and the suction port end. Shielding means for preventing the sprayed washing water and contaminated water after washing from splashing to the outside, and the discharge pressure of the washing water ejected from the nozzle in the shielding means is a negative pressure by the recovery means. The main feature is that a pressure adjusting means for maintaining a predetermined pressure balance is provided so that the predetermined cleaning force is not attenuated by the suction force.

According to this configuration, it is possible to perform decontamination while maintaining a predetermined pressure balance by adjusting a negative suction force that does not attenuate the discharge pressure of the wash water according to the state of the decontamination target. In the present invention, the cleaning water includes so-called natural water such as tap water in addition to a cleaning agent such as a surfactant. However, since it does not require a step such as rinsing after cleaning, and further, there is no difference in the cleaning effect depending on the presence or absence of the cleaning agent by the pressure adjusting means. Is preferred.

The predetermined pressure balance is composed of combination data of the discharge pressure and the suction force according to various conditions of the cleaning object, and the pressure adjusting unit is configured to combine the combination data according to the condition of the cleaning object. There may be selection means that can select the pressure balance data configured from the above, and the driving means may be driven by the selected pressure balance data.

The pressure adjusting unit may include a suction force switching unit capable of increasing a negative suction force constituting the predetermined pressure balance. For example, in order to suck soil that has entered a very narrow gap and has been consolidated and dried, it is better to first suck in the soil after washing it with washing water than to suck it with a large negative pressure from the beginning. It is effective. Therefore, it is possible to perform decontamination without difficulty by providing a switching means that can change the pressure balance stepwise. Further, it is possible to prevent the cleaning surface from being damaged by excessive discharge pressure or suction force.

In addition, it becomes possible to reuse contaminated water as washing water by providing a supply means that supplies water purified or conditioned by the turbid water treatment means and connected to the storage means.

Further, the decontamination method according to the present invention is a decontamination method by high-pressure cleaning for a workpiece contaminated with radiation and an object to be cleaned such as a road, and can be collected on the object to be cleaned without high-pressure cleaning. A high-pressure cleaning pretreatment step for sucking in various contaminants as necessary, a step of pumping cleaning water at a high pressure using a driving source, and the high-pressure pumped cleaning water, In order to prevent discharge from the nozzle to the outside through a water supply hose, a closed space is formed by shielding between the connection end of the nozzle of the water supply hose and the cleaning surface of the object to be cleaned from the outside. And a step of ejecting cleaning water from the nozzle in the closed space, and the cleaning water sprayed from the nozzle in the closed space becomes contaminated water after cleaning the object to be cleaned. The vacuum tank with a negative pressure source A step of sucking and collecting through the suction hose in the closed space, and a muddy water treatment step of purifying or conditioning the collected contaminated water, and ejecting the washing water and contaminating A pressure adjustment processing step of maintaining a predetermined pressure balance so that the discharge pressure of the cleaning water is not attenuated by the negative suction force when the water is sucked; The most important feature.

Further, the pressure adjustment processing step includes a first processing step for performing cleaning and suction while maintaining the predetermined pressure balance, and the same cleaning object processed by the first processing step. You may make it comprise from the 2nd process process which makes the suction force of the said negative pressure increase rather than a 1st process process, maintaining discharge pressure.

  The decontamination system and the decontamination method according to the present invention are the scattering and outflow of contaminated water, which is a problem in high-pressure washing, even in a general urban environment that is not specialized in a special environment such as a so-called nuclear power plant building. In addition, it is possible to prevent damage to the cleaning symmetry surface due to excessive pressure and perform effective high-pressure cleaning.

In addition, while cleaning with high pressure, the contaminated water can be purified and conditioned and reused as cleaning water, so that it is possible to continuously perform decontamination over a wide area such as in urban areas. .

Furthermore, since no detergent such as a surfactant is required, decontamination can be performed at a low cost, and a rinsing step for washing away the detergent is unnecessary, so that the decontamination work can be carried out with high efficiency. There is an effect that can be done.

FIG. 1 is a schematic configuration diagram of a decontamination system according to the present invention. FIG. 2 is a schematic configuration diagram of a decontamination system according to another embodiment capable of making the suction force variable. FIG. 3 is a conceptual diagram showing a mechanism for pulling out and storing the second to third casings constituting the muddy water treatment unit of the decontamination system according to the present invention. FIG. 4 is a conceptual diagram showing a winding mechanism in the case where a stainless steel mesh material is used for the second-layer filter medium constituting the muddy water treatment unit of the decontamination system according to the present invention. FIG. 5 is a conceptual diagram showing a supply mechanism for supplying a coagulating precipitant to the first layer constituting the turbid water treatment unit of the decontamination system according to the present invention. FIG. (B) is a figure which shows the state which is supplying the coagulating precipitation agent to a 1st layer from a supply mechanism. FIG. 6 is a view showing the inside of a shielding hood provided with a nozzle for ejecting cleaning water and a suction port for contaminated water. FIG. 7 is a top perspective view of the first layer of the muddy water treatment unit of the decontamination system according to the present invention. FIG. 8 is a top view showing a modification of the first layer of the muddy water treatment unit of the decontamination system according to the present invention. FIG. 9 is a view showing a flexible tube connected to a discharge port of a modified example of the first layer of the muddy water treatment unit. FIG. 10 is a diagram showing a processing flow of the decontamination method according to the present invention.

  FIG. 1 is a schematic configuration diagram of a decontamination system according to the present invention. Reference numeral 1 denotes a storage tank that stores cleaning water. Wash water in the storage tank 1 is connected to the high pressure washer 3 via the connection hose 2 and is pumped by the high pressure washer 3. The high-pressure washing machine 3 is connected to the drive power source 4 and enables pumping of washing water. For example, in the case of a concrete surface and a pavement (for example, water-permeable pavement, interlocking) in an urban area, the maximum discharge pressure of the high-pressure washing machine 3 may be about 15 MPa to 20 MPa. Further, the drive power source 4 is assumed to be decontaminated in an urban area, and may be, for example, a low noise type diesel generator. For example, a three-phase 220V, 60 Hz output of 5.5 kW to 6.3 kW is desirable.

The high pressure washer 3 is connected to the discharge attachment 6 via the water supply hose 5, and the cleaning water is jetted from the tip of the discharge attachment 6 toward the object to be cleaned by the nozzle. The discharge attachment 6 includes a long handle 61, a shielding hood 62 containing a nozzle (not shown) connected to the tip of the water supply hose 5, and the handle so that the operator can move it by hand. The caster 63 is configured to be able to move on the surface to be cleaned by transmitting the hand pushing force of the operator 61 to the shielding hood 62. The handle 61 is a bundle of two pipe-shaped rods, and the longitudinal end of the worker side is divided into two branches so that the worker can hold it with both hands. . Further, the other end of the handle 61 in the longitudinal direction is connected to the upper surface of the shielding hood 62 in the same manner as described above. The connection between the handle 61 and the upper surface of the shielding hood 62 is pivotally supported so that the handle 61 can be pivoted up and down so that the handle 61 can be gripped according to the height of the operator. As will be described later (see FIG. 6), the shielding hood 62 has a cylindrical shape having an open end with a flat bottom in the height direction, and has a hollow inside. It is the shape which can form a closed space between. A cleaning brush 64 is densely planted in the circumferential direction on the peripheral edge of the shielding hood 62 on the open end side. Three casters 63 are attached at equal intervals of 120 degrees in the circumferential direction of the shielding hood 62, but the number of casters and installation locations are not limited to this.

A blower-type vacuum recovery machine that collects contaminated water (including contaminants floating together with contaminated water) subjected to high-pressure washing with a nozzle in the shielding hood 62 and collects the contaminated water in a vacuum state of the vacuum tank. 7 is collected on the collecting drum 8. The vacuum recovery machine 7 may be, for example, one having a vacuum pressure of −50 kPa and a maximum air volume of about 8 m ³ / min. The operation of the vacuum recovery machine 7 may be connected to the drive power supply 4. In addition, since collection | recovery of the contaminated water in the shielding hood 62 is performed simultaneously with the washing | cleaning by the said nozzle, the ejection of washing water and the attraction | suction of contaminated water advance simultaneously. The vacuum recovery machine 7 is connected to a suction hose 9 via a recovery drum 8. The tip of the suction hose 9 is airtightly connected to a suction port (see FIG. 6) opened on the upper surface of the shielding hood 62, and contaminated water generated in the closed space of the shielding hood 62 is sucked from the suction port. Then, it is recovered from the suction hose 9 to the recovery drum 8. In the present embodiment, the collection drum 8 includes two collection drums 8a and 8b. However, the collection capacity may be freely determined according to the region to be decontaminated. It is not intended to be limited to.

The contaminated water recovered by the recovery drum 8 is connected to the turbid water treatment device 11 via the turbid water hose 10. The muddy water treatment apparatus 11 is configured by laminating a first layer 111, a second layer 112, a third layer 113, and a fourth layer 114. The stacking direction is such that the second layer 112 hangs down from the first layer 111, the third layer 113 hangs down from the second layer 112, and the fourth layer 114 hangs down from the third layer 113. ing. The contaminated water is sent from the muddy water hose 10 to the first layer 111. In addition, what is necessary is just to interpose a pumping pump (not shown), for example for the sending of the contaminated water from the collection | recovery drum 8 to the 1st layer 111 via the muddy water hose 10. FIG. In the first layer 111, as will be described later (see FIG. 7), a coagulating precipitant is added to the collected contaminated water, and after stirring with a stirrer, a solid substance coagulated with the coagulating precipitant (radiated and contaminated) The contaminated water containing the substance) is filtered. The coagulating precipitant is preferably an inorganic one having a natural mineral as a main component and having a low environmental load, and the floc diameter to be produced is preferably about 1 to 2 cm. Moreover, as a 1st filter material of a 1st layer, what has the filtration precision which does not let the said floc pass is sufficient, and a raw material is not limited. For example, it may be a polypropylene net or a so-called cloth bag.

Further, a fine solid substance having a particle size that cannot be filtered by the first filter medium is filtered by the second filter medium of the second layer 112 and the third filter medium of the third layer 113. The second filter medium is preferably a mesh material of about 50 mesh, and the third filter medium is preferably a nonwoven fabric having a filtration particle size of about 5 μm. The fourth layer 114 purifies the water by passing the water dropped through the third filter medium through an adsorbent such as activated carbon.

According to the embodiment, that is, the filtration particle size of the first to third filter media and the adsorbent of the fourth layer, for example, 10,000 to 40,000 bq (Becquerel) contaminated water is a standard for drinking water determined by the Ministry of Health, Labor and Welfare. Water can be purified to a value, that is, about 10 bq / kg.

As described above, the muddy water treatment apparatus 11 is sequentially suspended from the first layer 111 through the second layer 112 to the third layer, so that it can be dropped by gravity according to the order of filtering the contaminated water. Therefore, in the treatment of muddy water, it is possible to purify contaminated water smoothly and at low cost even in an environment where a sufficient power source cannot be secured such as decontamination of urban areas etc. Become. Depending on the application, the purified water may be conditioned by electrolysis or the like. The water purified by the turbid water treatment device 11 can generate cleaning water from the contaminated water by connecting the third layer 113 and the storage tank 1 with the water purification hose 12, and can be reused as cleaning water. Become. Therefore, even in an environment where cleaning water cannot be sufficiently supplied, such as decontamination of urban areas while moving, decontamination work can be performed efficiently by reusing contaminated water. In addition, what is necessary is just to use a pumping pump (not shown) for supply of the purified water to the storage tank 1 via the said purified water hose 12. FIG.

Since decontamination work in urban areas is decontaminated while moving in a wide range, equipment that is a component of the system in FIG. 1 can be loaded on a cargo bed such as a truck to ensure portability. is necessary. In the present embodiment, it is assumed that the components of the system described in FIG. 1 can be loaded on a 2t truck bed.

However, decontamination work in urban areas varies from a relatively small decontamination area such as a general house to a large scale such as a public facility, a school, a shopping center, and a large parking lot. In decontamination of general houses, it is important to have the above portability. However, in the case of a large-scale area, it is necessary to increase the size of the turbid water treatment device 11 itself and reduce the replacement frequency of filter media and improve work efficiency. On the other hand, in mobile decontamination work, portability must also be ensured. For example, considering the balance between the increase in size and portability of the turbid water treatment device 11, the turbid water treatment device 11 has an outer shape of about 3,000 mm × 3,000 mm × 2,000 mm, and the first layer 111 has a radius of 600 mm and a high height. It is preferable that the length is 1,000 mm and the capacity is about 1,000 L.

When the muddy water treatment apparatus 11 is enlarged, the replacement frequency of each filter medium can be reduced, while the work load at the time of replacement increases due to the weight of each layer and the filter medium, the wide area of the area, and the like. For example, the second filter medium, the third filter medium, and the adsorbent are housed in a casing constituting the second layer 112, the third layer 113, and the fourth layer 114, but with the progress of muddy water treatment Since the filtration accuracy and the adsorption accuracy are lowered, it is necessary to replace each filter medium and adsorbent appropriately during the work. However, as described above, due to the increase in the size of the turbid water treatment device 11, it takes time and effort to uniformly lay each filter medium and adsorbent on the casing. If each filter medium and adsorbent cannot be laid uniformly, the filtration accuracy is lowered, and as a result, there arises a problem that muddy water treatment with sufficient effects cannot be performed. Therefore, in order to easily pull out and store the casing, the configuration shown in FIG. 3 is adopted.

In FIG. 3, the case of the second layer 112 is shown as an example, but the third layer and the fourth layer have the same structure. The second layer 112 includes a grid-shaped casing 112a, and the upper surface and the bottom surface are open. On one side surface of the housing 112a, a rotating body 112c capable of rotating in the forward and reverse directions in the stacking direction, a lever 112d for rotating the rotating body 112c, and a straight line perpendicular to the rotating direction of the rotating body 112c. A slide body 112b for converting the movement direction is provided, and the housing 112a can be operated in a retractable direction and a retractable direction. That is, when the lever 112d is rotated in the pull-out direction, the rotating body 112c is also rotated in conjunction with the rotation, and this rotational motion is transmitted to the slide body 112b as a linear motion in the pull-out direction. On the other hand, if the lever 112d is rotated in the storage direction, the casing 112a can be moved in the linear motion in the direction opposite to that described above, that is, in the storage direction. The rotating body 112c and the slide body 112b are not particularly limited as long as the rotating motion can be converted into a linear motion, such as a configuration including a rack and a pinion and a configuration including a pulley and a wire. With such a configuration, it is possible to easily replace the filter medium in the housing 112a, and it is possible to improve work efficiency.

The filter medium laid on the casing 112a is preferably a metal (in particular, stainless steel) mesh material from the viewpoint of durability and the like. It is troublesome to stretch the metal mesh material on the enlarged casing 112a, and the working efficiency is lowered. FIG. 4 is a side view of a winding mechanism for efficiently performing such a tensioning operation. The housing 112a has a pair of mounting tables 112f for mounting a rectangular mesh material 112e in a direction orthogonal to the stacking direction. The mounting table 112f is formed so as to protrude toward the opposite side walls on the inner side of the opposite side wall of the casing 112a so as not to block the opened bottom surface side of the casing 112a. The mesh material 112e mounted on the mounting table 112f is locked by a pair of rotating rollers 112g and 112h at both ends on the side not mounted on the mounting table 112f. The rotating roller 112h on the pulling direction side described in FIG. 3 is connected to the winding drive source 112j via the transmission belt 112i. When the winding drive source 112j is driven, the rotating belt 112h is driven by the transmission belt 112j. The rotational force is transmitted to the opposing rotating roller 112g. The mesh material 112e is wound around the rotation roller 112g in advance for a predetermined number of rotations. When the mesh material 112e needs to be replaced, a new mesh material 112e is obtained by driving the winding drive source 112j. Laid. With such a winding mechanism, the mesh material 112e can be stretched on the mounting table 112f without causing a twist or the like.

The coagulating precipitating agent needs to be replenished as appropriate because the coagulating effect is reduced when the amount of contaminated water input exceeds a certain amount. The replenishment of the coagulating precipitant is performed from the upper direction of the first layer 111. As described above, when the muddy water treatment device 11 is enlarged and the height in the stacking direction is increased, the replenishment work from the upper direction becomes complicated. . Therefore, even in the turbid water treatment apparatus 11 having a height, a dispenser (supply mechanism) 115 may be installed in the vicinity of the upper portion of the first layer 111 as shown in FIG. .

FIG. 5 a shows a side view of the coagulating precipitant C in the dispenser 115 in a full state. The dispenser 115 includes a coagulation / sedimentation agent storage container 115a, and a supply hole 115h for supplying the coagulation / sedimentation agent C to the first layer 111 is opened on the bottom surface of the coagulation / sedimentation agent storage container 115a. The supply hole 115 is closed by an on-off valve 115i. The on-off valve 115i is connected to the handle lever 115j via a connecting member 115k. A hollow injection adjusting pipe 115b for introducing the coagulating precipitant in an external coagulating precipitant supply tank (not shown) is provided on the side wall of the coagulating precipitant storage container 115a. The injection adjusting pipe 115b has an introduction port 115c opened near the lower side of the side wall of the coagulation / precipitation agent storage container 115a, and is connected to the coagulation / precipitation agent supply tank. The injection adjusting pipe 115b is bent in an L shape from the introduction port 115c toward the upper surface of the coagulating / precipitating agent storage container 115a, bent again in an L shape near the tip, and the bent end portion is the outlet 115d. Is open. The bent portion in the upper surface direction of the injection adjusting pipe 115b is such that the hollow portion of the injection adjusting pipe 115d is slidable by the shut-off valve 115e that blocks the penetration between the inlet 115c and the outlet 115d. Is provided. The top end in the upper surface direction of the shutoff valve 115e protrudes beyond the end of the injection adjusting pipe 115d. A concave portion is provided at the protruding tip of the shutoff valve 115e, and a liquid level adjustment rod 115f is fitted into the concave portion. A float 115g is attached to the tip of the liquid level adjusting rod 115f opposite to the fitting side. The float 115g may be formed of a material that floats on the liquid level and does not come into contact with the liquid level, such as a foam material or the like that lowers its own weight.

FIG. 5B is a diagram showing a state in which the coagulating precipitant is supplied to the first layer 111. When the handle lever 115j is operated and the on-off valve 115i is lifted from the full water state, the coagulating sedimentation agent C is supplied from the supply hole 115h to the first layer, and the water flow generated near the supply hole 115h causes the on-off valve 115i. An open state is maintained. On the other hand, the float 115g is also lowered by its own weight due to the lowering of the liquid level in the coagulating sediment storage container 115a. As the float 115g descends, the liquid level adjustment rod 115f also operates in the descending direction, and by this operation, the shutoff valve 115e slides inside the injection regulator 115d and rises in the upward direction. As the shutoff valve 5e rises, the inlet 115c to the outlet 115d penetrate, and the aggregated precipitant is supplied into the aggregated precipitant storage container 115a from the aggregated precipitant supply tank.

When the liquid level reaches the vicinity of the on-off valve 115i, the water flow is weakened, the on-off valve 115i is lowered, the supply hole 115h is closed, and the supply of the coagulating precipitant into the coagulating precipitant storage container 115a is performed. The liquid level rises again. The float 115g is lifted as the liquid level rises, and the shutoff valve 115e is lowered by the liquid level adjusting rod 115f. When the water level is reached, the shutoff valve 115e shuts off the inlet 115c and the outlet 115d. The supply of the coagulating precipitant into the coagulating precipitant storage container 115a is stopped.

By installing the dispenser 115, it is possible to inject a predetermined amount from the top of the muddy water treatment device 11 by operating the handle lever 115j even if the operator does not inject the coagulating sediment into the first layer. When the apparatus is enlarged, the work efficiency is increased.

  By the way, as described above, since the ejection of the cleaning water and the suction of the contaminated water proceed simultaneously, the cleaning power is weakened when the discharge pressure of the cleaning water is attenuated by the negative suction force of the vacuum recovery machine 7. There is a risk that a sufficient decontamination effect cannot be obtained. On the other hand, if the suction force is reduced in order to enhance the cleaning power, sufficient recovery cannot be obtained, and there is a risk that radiation contamination will increase due to outflow of contaminated water. In addition, if the cleaning water is ejected by an excessive discharge pressure, the cleaning target may be damaged. For example, in the case of permeable paved roads, in order to infiltrate rainwater etc. into the ground, the gaps between the aggregates are made relatively large. There is a possibility of consolidation by repeating the state. Such earth and sand cannot be easily washed, and if only the discharge pressure is increased, the white lines and characters painted on the road will be erased, and in some cases the bond between aggregates will be destroyed, and the road It may damage the surface.

Therefore, the system according to the present invention includes a pressure adjusting device (not shown) in order to maintain a pressure balance between the discharge pressure and the suction force. The adjustment by the pressure adjustment device sets the combination that maintains the balance between the discharge pressure and the suction force according to the condition of the object to be cleaned, and after investigating the condition of the object to be cleaned before cleaning, What is necessary is just to enable it to select a combination. For this selection, a dial-type knob or the like capable of selecting a variation of the combination is provided on the handle portion of the discharge attachment 6 and the pressure adjustment of each of the high-pressure washing machine 3 and the vacuum recovery machine 7 is performed by adjusting the knob to a desired combination. The pressure may be adjusted by mechanically operating a pressure adjustment button or the like for performing the control, or the pressure selection of the high-pressure washing machine 3 and the vacuum recovery machine 7 may be controlled by a portable electronic computer. The content of the pressure selection includes, for example, an optimal combination of the state of the cleaning object, the discharge pressure and the suction force as a table. When the state of the cleaning object is selected, the discharge pressure data of the optimum pressure balance is automatically The suction force data may be transmitted to the high pressure washer 3 and the vacuum recovery unit 7 so that the suction force data can be automatically output at each pressure.

Here, the electronic computer has a central processing unit (CPU), a main memory, and an external storage device such as a hard disk, and an input unit for inputting a command from an input device such as a keyboard in order to perform the selection function, A display unit composed of a display or the like is connected. The table is input in advance from the input device. This table can be freely modified and added from the input device. Before starting the decontamination work, select a desired combination with the input device, and input a command to execute the process, the program or file for executing the process to the main memory is read, by the CPU, The process is executed. That is, the system according to the present invention is configured to execute a program for performing processing according to the specific usage purpose by hardware resources such as the CPU, main memory, and external storage device.

However, the selection mechanism is not limited to these examples, and the pressures of the high-pressure washing machine 3 and the vacuum recovery machine 7 may be set manually according to a predetermined manual.

  FIG. 2 is another embodiment of the decontamination system described in FIG. The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  If there is a relatively sparse void such as a water-permeable paved road or interlocking, as mentioned above, dirt and dust accumulate, the meshing becomes solid due to aging, and even with the pressure adjustment Effective decontamination may not be possible. Therefore, in the present embodiment, two vacuum recovery machines 7a and 7b are combined, and the pressure regulator adjusts the switch (see FIG. 5) so that the negative pressure constituting the pressure balance can be increased. Not shown). The suction hose 9 is branched through the collection drum 8 in front of the vacuum collection machines 7a and 7b. The branch point 91 may be connected to a branch joint or the like. The branched suction hose 9 is divided into 9a connected to the vacuum recovery machine 7a side and 9b connected to the vacuum recovery machine 7b side. The switch may be provided with, for example, a lever or the like that can operate or stop the vacuum recovery machine 7b on the handle of the discharge attachment 6 so that the operator can operate while looking at the state of the object to be cleaned.

  FIG. 6 is a view showing the closed space formed inside the shielding hood 62. In the closed space C, a suction port 66 opened on the upper surface of the nozzle 65 and the shielding hood 62 is provided. The nozzle 65 includes an arm 651 whose longitudinal direction is the inner diameter direction of the closed space C of the shielding hood 62, a washing water ejection portion 652 provided at both longitudinal ends of the arm 651, and the arm 651 is an upper surface of the shielding hood 62. A support body 653 that rotatably supports the center of gravity of the arm 651 at the center of the upper surface of the shielding hood 62 so as to rotate in the circumferential direction.

  The nozzle 65 ejects cleaning water from the ejection portions 652 provided at both ends of the arm 651 while the arm 651 rotates. By configuring in this way, the surface to be cleaned covered by the closed space C can be uniformly and uniformly supplied with cleaning water in a short time without impairing the cleaning effect due to the discharge pressure. Further, since the suction port 66 is only momentarily interrupted when the thin arm 651 rotates at high speed, at least the suction force is hardly physically interrupted by the presence of the nozzle 65.

  FIG. 7 is a partial perspective view seen from the upper surface side of the first layer 111 of the muddy water treatment apparatus 11. The 1st layer 111 supplies contaminated water from the muddy water hose 10 (refer FIG. 1, FIG. 2), and adds a coagulating precipitation agent to this. For the purpose of decontamination, as described above, an agglomerated precipitating agent is suitable because it is low in environmental burden and high in safety, and pays attention to the high adsorption property of cesium to the soil. After the contaminated water to which the coagulating precipitant has been added is stirred by the stirrer 111a in the first layer 111, after a while, the solid matter adsorbed with cesium precipitates and is separated from the water. The precipitated solid is collected in the first filter medium 111d from the drain port 111c, and only the separated water is filtered by the first filter medium 111d and dropped onto the second layer 112.

  The first layer has a cylindrical shape for uniformly adding the coagulating precipitation agent to the contaminated water by the stirrer 111a, and the stirrer 111a is installed on the substantially central axis of the bottom surface 111b of the first layer. To do. Further, the drooping direction at the installation position of the stirrer 111a is formed in a tapered shape so that the precipitated solid matter is concentrated at the drain port 111c, and the drain port 111c is formed at the bottom end. ing.

FIG. 8 is a modification of the first layer 111. As described above, when the muddy water treatment device 11 is enlarged, the area of the bottom surface 111b of the first layer 111 is also increased. The purpose of increasing the size is to increase work efficiency by filtering a large amount of contaminated water at a time. Therefore, when the size is increased, if filtration is performed with only one drain port 111c, not only the filtration speed is lowered, but also the replacement frequency of the first filter medium 111d is increased, and the work efficiency may be lowered. . Therefore, in the modification of FIG. 8, in addition to the discharge port 111 c described in FIG. 7, a plurality of discharge ports 111 e to 111 h are opened from the discharge port 111 c in the radial direction of the bottom surface 111 b, and the discharge ports 111 e to 111 h A first filter medium 111d is provided, and the plurality of discharge ports 111e to 111h are opened at equal intervals in the circumferential direction of the bottom surface 111b. In the present embodiment, the number of openings is four. However, the present invention is not limited to this, and may be changed to a discharge port 111c opened around the diameter of the discharge port. Note that the bottom surface 111b may be tapered or a horizontal surface without inclination.

FIG. 9 is a modification of the first layer 111 described in FIG. A flexible tube 111i that is hollow and expandable toward the second layer 112 is connected to each of the discharge ports 111c to 111h, and the first filter medium 111d is attached to the open end of the flexible tube 111i on the second layer 112 side. It is a cover. In FIG. 9, although the discharge port 111e is described, the other discharge ports have the same configuration. When the turbid water treatment device 11 is enlarged, the replacement work of the first filter medium 111d covered by the discharge ports 111c to 111h must be performed in the space between the first layer 111 and the second layer 112. Rather, it is a complicated task. Therefore, by interposing the flexible tube 111i, the filter medium 111d can be brought close to the operator side, and the work can be simplified. Furthermore, in order to increase working efficiency, the first layer 111 may be configured to be rotatable in the circumferential direction of the bottom surface 111b (not shown).

  FIG. 10 is a flowchart of the decontamination method according to the present invention. Hereinafter, a description will be given with reference to FIGS.

Before entering the decontamination work, the dose of the decontamination object is measured (S1). In the dose measurement, for example, the surface of 5 cm and the surface of 100 cm are measured 2 counts every 30 seconds, and the average value is used as the dose of the object to be decontaminated (decontamination site). (However, the measurement follows the agreement of the Ministry of the Environment at the time of decontamination.)

  A pretreatment is performed to remove the dust in the decontamination range including the place where the dose measurement has been performed, and the amount of radioactive material recovered during high-pressure cleaning is reduced (S2). This pretreatment can increase the time during which high-pressure cleaning can be performed efficiently and continuously. In addition, what is necessary is just to select this pre-processing according to the environment of a decontamination location etc., such as a diesel engine drive type sweeper, a vacuum cleaner, or an operator's manual work.

  When the pretreatment is completed, the pressure of the discharge pressure of the high-pressure washing machine 3 and the suction force of the vacuum recovery machine 7 is adjusted by looking at the situation of the decontamination target location (S3). There are various types of pressure adjustment, such as drainage pavement, water permeable pavement, concrete pavement, interlocking, etc. Different. In the case of structures with large voids and soil and sand that can easily enter over time (for example, water-permeable pavement), accurate decontamination (decontamination that reduces to the dose set by the Ministry of the Environment) is required unless cleaning is performed at a high pressure. I can't do it. On the other hand, if the discharge pressure is excessively increased, the surface may be damaged. Note that even if the suction force is excessively increased, the discharge pressure may be attenuated, so that sufficient decontamination may not be possible.

Therefore, in the decontamination method of the present embodiment, an optimum pressure adjustment value is determined according to the type of the cleaning portion and the pressure can be adjusted so that decontamination can be performed according to this value. I made it. The pressure adjustment may be performed by separately adjusting the pressures of both the high-pressure washing machine 3 and the vacuum recovery machine 7, but the electronic data of the discharge pressure and the suction force set in advance according to the type of the washing part is electronically stored. It is also possible to automatically set the discharge pressure and the suction force by holding it in a computer or the like and selecting it.

  In addition, when the mesh of sand or the like solidified in the gap is strong and cannot be sufficiently recovered by the pressure adjustment, the washing water is infiltrated into the solidified sand and sand mainly with washing water in the first decontamination. Then, the suction force may be increased for the second time for the same portion. In order to increase the suction force, the vacuum recovery device 7 may be added to synthesize a plurality of suction forces.

  After adjusting the pressure, high-pressure washing water is pumped by the high-pressure washing machine 3 (S4), and the washing water is ejected from the nozzle 65 of the discharge attachment 6 (S5). Simultaneously with the ejection of the cleaning water, the contaminated water generated by the cleaning water ejected in the shielding hood 62 decontaminating the surface to be decontaminated is collected in the closed space C of the shielding hood 62 (S6).

  The collected contaminated water is purified by adding a coagulating precipitant to the turbid water treatment device 11 and stirring it (S7). The dose of purified water generated by the muddy water treatment device is measured (S8), and if it is purified water that can be used as washing water, it is replenished to the high-pressure washing storage tank 1 for reuse as washing water (S9). ).

  In S8, the separated substance separated from water by the coagulating precipitant added to the turbid water treatment apparatus is naturally dried and then enclosed in a dedicated shielding container (S10).

  In addition, the dose of the said decontamination location measured in S1 is measured again after completion | finish of decontamination (S11), it confirms that it is below a predetermined dose, and decontamination is complete | finished.

Comparing the work efficiency of the high-pressure cleaning that has been conventionally performed and the decontamination system or decontamination method according to the present invention in terms of the decontamination area by the work of about 8 hours, the general high-pressure cleaning is 100-300 m ² contrast, in the case of the present invention was 600~1000m ^2. In this case, in general high-pressure washing, the amount of water used is 100 to 300 l / m ² , whereas the present invention is 4 to 8 l / m ² , which can realize considerable water saving. It was. Further, the decontamination rate was 10 to 50% in general high-pressure washing, whereas it was 40 to 90% in the present invention.

DESCRIPTION OF SYMBOLS 1 Storage tank 2 Connection hose 3 High pressure washing machine 4 Drive power supply 5 Water supply hose 6 Discharge attachment 7 Vacuum recovery machine 8 Recovery drum 9 Suction hose 10 Muddy water hose 11 Muddy water treatment apparatus 12 Water purification hose

The present invention relates to a decontamination system and a decontamination method by high-pressure cleaning, and more specifically, a decontamination system for cleaning a workpiece and a cleaning object such as a road contaminated with radioactive substances using high-pressure cleaning. And a decontamination method.

Conventionally, many decontamination apparatuses and decontamination methods have been proposed for decontamination with respect to contamination by radioactive substances in facilities and members in nuclear power plant buildings. For example, a device for decontaminating a floor surface in a nuclear power plant building, as an alternative to the wiping of a worker's waste, a plurality of brushes that rotate to take contaminated water into the center line of the vehicle body, There has been proposed a floor surface decontamination device including a water discharge device that discharges water in the vicinity and a suction device that sucks sewage taken in by the brush (see Patent Document 1). According to this floor surface decontamination apparatus, not only cleaning but also collecting sewage makes it possible to prevent diffusion of contaminated parts.

A decontamination system according to the present invention is a decontamination system by high-pressure washing for a workpiece and a washing object such as a road contaminated with radioactive substances, and is washed at high pressure from the washing water storage means and the storage means. The pressure-feeding means for pumping water, the discharge means for jetting the high-pressure pumped wash water from the nozzle through a water supply hose, and the wash water jetted from the discharge means with the vacuum tank in a negative pressure state. Recovery means for recovering the later contaminated water via a suction hose, turbid water treatment means for purifying or conditioning the recovered contaminated water, drive means for driving the pressure feeding means and recovery means, and the water supply A nozzle connection end of the hose and a suction port end of the suction hose are connected, and a closed space is formed between the cleaning surface of the object to be cleaned and the nozzle connection end and the suction port end. And a shielding means for preventing scattering of the serial nozzle to the outside of the contaminated water after washing water and cleaning ejected performs the recovery of the contaminated water by jetting and suction hose of the washing water by the nozzle on the fly Accordingly, the pressure adjusting means for maintaining a predetermined pressure balance so that the discharge pressure of the cleaning water ejected from the nozzle in the shielding means is not attenuated by the negative suction force by the recovery means. The main feature is that it has

Further, the decontamination method according to the present invention is a decontamination method by high-pressure washing for a workpiece contaminated with a radioactive substance and a washing object such as a road, and is on the washing object and not subjected to high-pressure washing. A high-pressure cleaning pre-treatment step for sucking contaminants that can be collected as needed, a step of pumping cleaning water at a high pressure using a drive source, and the high-pressure pumped cleaning In order to prevent water from being discharged from the nozzle through the water supply hose and to discharge the water, the gap between the nozzle connection end of the water supply hose and the cleaning surface of the object to be cleaned is shielded from the outside and closed. Forming a space and ejecting cleaning water from the nozzle in the closed space; and the cleaning water sprayed from the nozzle in the closed space becomes contaminated water after cleaning the object to be cleaned. Vacuum tank using the drive source A negative pressure state, a step of sucking and collecting the suctioned water through the suction hose in the closed space, and a muddy water treatment step of purifying or conditioning the recovered contaminated water, when performing suction simultaneous to contaminated water when jetted, the discharge pressure of the washing water, the by the suction force of the negative pressure so that a predetermined cleaning force is not attenuated, the pressure adjustment process to maintain a predetermined pressure balance It has the most important feature.

The contaminated water recovered by the recovery drum 8 is connected to the turbid water treatment device 11 via the turbid water hose 10. The muddy water treatment apparatus 11 is configured by laminating a first layer 111, a second layer 112, a third layer 113, and a fourth layer 114. The stacking direction is such that the second layer 112 hangs down from the first layer 111, the third layer 113 hangs down from the second layer 112, and the fourth layer 114 hangs down from the third layer 113. ing. The contaminated water is sent from the muddy water hose 10 to the first layer 111. In addition, what is necessary is just to interpose a pumping pump (not shown), for example for the sending of the contaminated water from the collection | recovery drum 8 to the 1st layer 111 via the muddy water hose 10. FIG. In the first layer 111, as will be described later (see FIG. 7), a coagulating precipitant is added to the collected contaminated water, and after stirring with a stirrer, solid substances aggregated by the coagulating precipitant (contaminated by radioactive substances) The contaminated water containing the material is filtered. The coagulating precipitant is preferably an inorganic one having a natural mineral as a main component and having a low environmental load, and the floc diameter to be produced is preferably about 1 to 2 cm. Moreover, as a 1st filter material of a 1st layer, what has the filtration precision which does not let the said floc pass is sufficient, and a raw material is not limited. For example, it may be a polypropylene net or a so-called cloth bag.

By the way, as described above, since the ejection of the cleaning water and the suction of the contaminated water proceed simultaneously, the cleaning power is weakened when the discharge pressure of the cleaning water is attenuated by the negative suction force of the vacuum recovery machine 7. There is a risk that a sufficient decontamination effect cannot be obtained. Meanwhile, in order to enhance the detergency and reduce the suction force, it can not be obtained sufficiently recovered, which may lead to spread of contamination by radioactive material I by the outflow of contaminated water. In addition, if the cleaning water is ejected by an excessive discharge pressure, the cleaning target may be damaged. For example, in the case of a water-permeable paved road, the gap between aggregates is made relatively large so that rainwater and the like can penetrate into the ground, and earth and sand enter the gap, which is dry and wet. There is a possibility of consolidation by repeating the state. Such earth and sand cannot be easily washed, and if only the discharge pressure is increased, the white lines and characters painted on the road will be erased, and in some cases the bond between aggregates will be destroyed, and the road It may damage the surface.

Claims (14)

A decontamination system by high-pressure cleaning for radiation-contaminated workpieces and roads and other objects to be cleaned,
Wash water storage means, pressure feed means for pumping wash water at a high pressure from the storage means, discharge means for ejecting the high pressure pumped wash water from a nozzle through a water supply hose, and vacuum tank with negative pressure Recovery means for recovering the contaminated water after being washed with the cleaning water ejected from the discharge means as a state via a suction hose, turbid water treatment means for purifying or conditioning the recovered contaminated water, Driving means for driving the pressure feeding means and the recovery means, the nozzle connection end of the water supply hose and the suction port end of the suction hose are connected, and between the cleaning surface of the object to be cleaned and the nozzle connection end and the suction port end A shielding means for forming a closed space, and preventing splashing of the cleaning water ejected from the nozzle in the closed space and the contaminated water after the cleaning,
Pressure adjusting means for maintaining a predetermined pressure balance so that the discharge pressure of the cleaning water ejected from the nozzle in the shielding means is not attenuated by the negative suction force by the recovery means. A decontamination system characterized by that.   The predetermined pressure balance is composed of combination data of the discharge pressure and the suction force according to various conditions of the cleaning object, and the pressure adjusting unit is configured to combine the combination data according to the condition of the cleaning object. 2. The decontamination system according to claim 1, further comprising a selection unit capable of selecting the pressure balance data configured by: and driving the driving unit according to the selected pressure balance data.   The decontamination system according to claim 1, wherein the pressure adjusting unit includes a suction force switching unit capable of increasing a suction force of a negative pressure constituting the predetermined pressure balance. .   The turbid water treatment means adds a coagulating precipitant to the recovered contaminated water, and is stirred by an agitating means to filter water from a radiation-contaminated solid substance coagulated by the coagulating precipitant. A first layer comprising: a second layer comprising a second filter medium for filtering a fine-grained substance contained in the water filtered in the first layer; and the second layer. A third layer for filtering a finer substance contained in water with a third filter medium made of a non-woven filter, and a fourth layer for allowing water filtered through the third layer to pass through the adsorbent. The first to the second layers are laminated downward so as to drop by gravity sequentially from the first layer to the fourth layer through the second layer and the third layer. 4. The decontamination system according to any one of up to 3.   The first layer has a cylindrical shape, the stirring unit is installed on a central axis in the stacking direction, and the first layer is formed in a taper shape whose bottom direction is the hanging direction of the installation position of the stirring unit. The decontamination system according to claim 4, wherein a discharge port provided with the first filter material is opened in the part.   The first layer has a cylindrical shape, the stirring means is installed on the central axis in the stacking direction, and a discharge port provided with the first filter medium is opened in a drooping direction of the installation position of the stirring means. In addition, a plurality of discharge ports are opened from the discharge port in the radial direction of the bottom surface of the first layer, and the first filter medium is disposed in each discharge port, and the plurality of discharge ports are the bottom surfaces of the first layer. The decontamination system according to claim 4 or 5, wherein the decontamination system is equidistant in the circumferential direction.   7. A hollow elastic flexible tube that is hollow in the direction of the second layer is connected to the plurality of discharge ports, and a first filter medium is provided at the open end on the second layer side. Decontamination system as described.   The decontamination system according to claim 6 or 7, wherein the first layer is rotatable in the circumferential direction.   At least one of the housing for storing the second layer and the third layer of the filter medium and the housing for storing the fourth layer of the adsorbent is a rotating means capable of rotating forward and reverse in the stacking direction, and the rotating means 9. A conversion means for converting the rotational motion by the linear motion direction perpendicular to the stacking direction, and enabling the housing to be pulled out and stored by the linear motion. The decontamination system according to any one of the preceding items.   The second filter medium is a rectangular metal mesh material having flexibility, and the casing of the second layer is a pair of placements in which the metal mesh material is laid in a direction orthogonal to the stacking direction. Means, a pair of rotating rollers that axially engage opposite ends of the metal mesh material, and one of the pair of rotating rollers is wound around the metal mesh material. Winding drive means for rotating in the direction, and when the metal mesh material is wound around the other rotating roller in advance among the pair of rotating rollers and the winding drive means is driven, The rotating drive of a rotating roller is transmitted to said other rotating roller, and the metal mesh material previously wound is newly laid, Any one of Claim 4-9 characterized by the above-mentioned. The decontamination system as described in the item.   A supply means is provided with a supply hole at a lower end of the storage container for the coagulating precipitant, and supplies the coagulating precipitant to the first layer from the supply hole, the supply means opening and closing to close and open the supply hole A float floated on the liquid level of the valve, the aggregated precipitant stored, and move up and down with the displacement of the liquid level, and inject the coagulant precipitant into the storage container as the float descends, An injection adjusting means for stopping the injection at a predetermined position when the float rises, and an opening lever for opening the opening / closing valve. When the opening / closing valve is opened by the opening lever, the first layer is formed through the supply hole. When the coagulating precipitant is supplied to the storage container and a new coagulating precipitant is simultaneously supplied into the storage container by the injection adjusting means, and the liquid level in the storage container is lowered to the open valve, the open valve is Close the supply hole The injection is stopped when the float rises to a predetermined position as the liquid level rises due to the supply of the new coagulating precipitant. The decontamination system as described in the item.   The removal according to any one of claims 1 to 11, further comprising a supply unit that supplies water purified or conditioned by the turbid water treatment unit and connected to the storage unit. Dyeing system. It is a decontamination method by high-pressure washing for radiation-contaminated works and objects to be washed such as roads,
A high-pressure cleaning pretreatment step for sucking, as necessary, contaminants that can be recovered without performing high-pressure cleaning on the object to be cleaned, and using a drive source for the object to be cleaned, And the discharge end of the water supply hose nozzle and the object to be cleaned are discharged through the water supply hose with the water supply hose interposed to prevent the nozzle from being scattered outside. A step of forming a closed space by shielding between the cleaning surface and the outside, and ejecting cleaning water from the nozzle in the closed space; and the cleaning water sprayed from the nozzle in the closed space The process of cleaning the object and becoming contaminated water is made by vacuuming the vacuum tank using the drive source and collecting it by suction through the suction hose in the closed space, and the recovered contamination Turbid water treatment process to purify or condition water , Has a,
Pressure adjustment to maintain a predetermined pressure balance so that the discharge pressure of the cleaning water is not attenuated by the negative suction force when the cleaning water is ejected and contaminated water is sucked A decontamination method comprising a treatment step.   In the pressure treatment step, a discharge pressure of the cleaning water is set for a first treatment step in which cleaning and suction are performed while maintaining the predetermined pressure balance, and the same cleaning object processed in the first treatment step. The decontamination method according to claim 10, wherein the decontamination method comprises a second treatment step that increases the suction force of the negative pressure more than the first treatment step while maintaining.

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