LT6682B - System and method for decontamination of contaminated metal tubes - Google Patents

Abstract

The present invention provides a system and method for deactivating inner and outer surfaces of tubular metal elements. The deactivation system includes a cutting line, flattening line, straightened element placement means and a washing line. The decontamination process includes the following steps: cutting a tubular metal member along one side of the member; straightening the tubular metal member to a metal plate; loading the metal plate into the means for holding; soaking of containers loaded with metal plates; removing contaminant particles from the metal plates during the washing step; management of canceled remains; flushing the remaining second solution from the means for containment; drying containers loaded with metal plates; determination of the radiation level of metal plates; repeating the deactivation process in case the security level has not been reached.

Description

TECHNICAL FIELD

The present invention relates to engineering solutions for providing industrial processes and technologies for the decontamination of contaminated metal pipes. Specifically, it is a high-throughput decontamination system and process for both internal and external surfaces of contaminated tubular metal elements dismantled from a nuclear power plant.

TECHNICAL LEVEL

The entire engineering solution, special technology and process have been developed taking into account the latest trends and tasks facing many countries. In particular, their respective radiation protection industries, which are addressing the issues of decommissioning the source of radioactive waste generation and how to manage the radioactive waste in a cost-effective manner without endangering human and environmental health.

Nuclear power plants generally use tube-type heat exchangers to transfer or store heat from / to the circulating water. The energy released during nuclear reactions is used to boil water. The steam generated generates energy for the steam turbine and the generator, and the steam leaving the steam turbine is condensed and collected. All this is done using tube-type heat exchangers, which are usually made of copper alloys such as CuNi, CuFeNi and the like, where copper accounts for more than 90% of the weight of the alloy.

And yet, over the years of operation, pipes in such systems absorb radiation to both internal and external surfaces. Radioactive particles are trapped in a thin layer of oxide film, which forms on the surface. Such contamination is extremely difficult to neutralize and clean up mechanically, and since decommissioning nuclear power plants is a relatively new task compared to their operation, the industry lacks efficient and completely safe technologies to carry out these processes.

Due to national and international regulations on radioactive waste management, regulatory practices and an increased safety culture, all components must be safely dismantled and disposed of in a way that will not endanger human health and the environment beyond the life of the plant. One inefficient way to manage radioactive waste is to dispose of all contaminated components in metal containers, which is expensive. In addition, components buried in the repository cannot be recycled for at least several decades.

Another sustainable and safe way to dispose of radioactive waste is to decontaminate radioactive materials, usually metals, to a safe level suitable for industrial reuse. A safe level is considered one that removes up to 100% of radioactive contaminants. One such method is described in Russian application no. RU2008107119 (A), published 10/9/2009. The present invention relates to the decontamination of metal surfaces containing radioactive sediment. These are elements such as the components of a nuclear reactor. The ultrasonic device for deactivating metal parts has an electrolytic bath. Underneath the electrolytic mirror is a contaminated component connected to the anode circuit, outer and inner cathodes, and power source wires. The tub has a removable cover fitted with an internal cylindrical cathode. The lid also has a resonator mounted on the same axis as the cathode. The outer cylindrical cathode is secured to the back of the tub bottom through an insulator. Ultrasonic emitters are firmly attached to the bath housing and resonator.

Japanese Application No. JP2005337778 (A), published 08-08-2005, describes an invention that is used to reduce the amount of sediment in the heat exchanger tube during finishing and to reduce the costs associated with waste storage and disposal by enabling simultaneous deactivation of both internal and external pipe surfaces and easy inspection. deactivation results with a suitable meter when the pipe is removed from the water heater. In order to solve the above problem, the present invention provides a method for implementing heat exchanger deactivation comprising dividing the heat exchanger tube into long and straight elements and deactivating radioactive materials adhering to the outer surface of the heat exchanger by cutting the pipes along. During the decomposition process, contaminated heat exchanger tubes are divided into two parts. The method further comprises decontamination of the radioactive materials and assessment of the safety level of the decontaminated materials.

Another Japanese application no. JP2007085796 (A), published April 5, 2007, discloses a method for detecting contamination of the inner surface of a pipe, deactivating said pipe, and recycling the pipe without a longitudinal section of the pipe. The heat exchanger tube, contaminated with radioactive particles, is divided into tubes of appropriate length. The cut pipes are flattened by a pressing machine.

The curved edges are then cut with a cutter. The remaining flat metal strips are decontaminated, their contamination is measurable and they are recyclable. The cut off folded parts are disposed of as radioactive waste.

All of these inventions are relevant to their purpose of providing a safe method of deactivating metal pipes. Invention no. RU2008107119 provides an electrolytic bath in which the tubes are washed by ultrasound. The main disadvantage of the present invention is the space and energy resources required to deactivate the pipes, since the pipes are washed in a tubular form. For this reason, high power ultrasonic processes and high concentrations of acid solutions are required for decontamination. Also, the cleanliness efficiency achieved by this solution is limited by the fact that the inner surfaces of the pipes are not effectively accessed and cleaned, thus either remaining contaminated or consuming a huge amount of time, energy and acid solution. In addition, the tubes remain tubular, which makes almost all types of radiation detection on the inner surface and the absorption of beta radiation on the outer surface almost impossible, since the measurement must be made very close to the surface, so accurate measurement can only be done on flat surfaces. Last but not least, the transportation and storage of tubular components is also inefficient.

Inventions no. JP2005337778 and ref. JP2007085796 discloses methods for flattening pipes by cutting or flattening them. However, these inventions generate significant yields of contaminated waste, usually in the form of metal shavings or cuttings. This contaminated waste must be disposed of in an appropriate manner in accordance with regulated methods, such as disposal or storage.

THE SUBSTANCE OF THE INVENTION

The purpose of the present invention is to effectively decontaminate metal tubular elements dismantled from heat exchangers of a nuclear power plant in an economical way. Another aim is to provide full control of radioactive contaminants by optimizing radioactive waste management. Finally, the third objective is to provide a sustainable way of recycling metals and their alloys. More specifically, a method for tubes made of fairly rigid copper alloys.

The main features of this complete engineering solution are:

1. High industrial power, versatility and durability;

2. Complete decontamination of contaminated metals or metal alloys;

3. 100% separation of contaminated sediment into a suitable compact container;

4. Enabling metal operation after 100% radiation control;

5. Compact packaging of the final output (metal plates and contaminants) for transportation or storage, enabling the recycling of metal plates in other industries;

6. The green method: the process is carried out without the use of untreated or uncontrolled waste such as chips, dust, etc .;

7. This method has been shown to be highly active and industrially tested.

The present invention provides specific and unique features as compared to similar technological solutions and techniques currently used in the world:

1. The complete engineering solution provides highly efficient up to 100% deactivated material (metal alloy) as well as automated machining and preparation of tubular metal elements.

2. Contamination control is implemented throughout the process. The most sophisticated beta radiation screening is 100% screened by a detector located at the shortest distance from the deactivated metal surface.

3. This is possible due to the machining of metal tubular elements into metal plates, which allow 100% verification of radioactive contamination and compact loading and transport at the end of the process for operation and finally recycling in other industries.

4. This technology ensures that contaminated product is cleaned without uncontrolled waste, such as contaminated metal shavings or dust, which endanger the health of workers involved in various types of decontamination processes in nuclear power plants.

The remaining contaminated sediment collected from the washing solution can be easily stored and stored for many years in dedicated compact containers that are integrated into the proposed engineering solution.

The present invention overcomes the aforementioned drawbacks of the prior art by providing a system and method for deactivating surfaces of contaminated heat exchanger pipes or other contaminated metal tubular members. The basic principle of this method is to expand and straighten the tube without generating radioactive residues such as filings or dust. The deactivation system includes a cutting line, a straightening line, a washing line and pipe holding means. All of these steps are arranged in a seamless industrial process optimized for the best yield.

This method involves the following steps: cutting the pipes along one side; pipe straightening; placing the straightened tubes in the holding means; soaking of containers filled with straightened metal plates; removal of radionuclides from metal plate surfaces by washing in acidic ultrasonic bath; treatment of removed residues; flushing the solution from the metal plates in the containers; determination of the radiation level of metal plates; repeating the deactivation steps until 100% security is achieved; drying of metal plates placed in storage media.

This process is unique in the way the metal tubular element is cut, which produces the incised elements without generating dust, debris, or other contaminated residues that would otherwise need to be treated by other radioactive waste management methods, such as burial or storage. Also, this process is unique in its way of slabing, in which the tubular member is gradually straightened to a metal plate. In addition, this method involves a novel washing step in which ultrasonic generators are positioned on the sides of straightened metal plates and all radioactive sediment is sucked out of the lower part of the washing container and then collected in a filtration device.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings in the drawings are provided by way of reference only and are not intended to limit the scope of the invention in any way. None of the drawings provided should be construed as limiting, but merely as an example of a possible embodiment of the invention. Sample line drawings for the decontamination process.

FIG. 1 illustrates, in a preferred embodiment, a schematic diagram of a cutting line of a metal tubular member in a deactivation system. The cutting line comprises pushing means (7) and tube cutting means (16), which are installed in the machine so that pushing means (7) push the tube along the cutting means, dividing the tube lengthwise. Axonometric projection image.

FIG. 2 illustrates, in a preferred embodiment, a schematic diagram of a cutting line with a plurality of rollers disposed along a sharp blade adapted for cutting. Axonometric projection image.

FIG. 3 illustrates a schematic diagram of a preferred pipe planing embodiment of a preferred embodiment. The flattening line (3) comprises flattening means (6) which are mounted in the machine so that the flattening means (6) gradually flatten the tube into the metal plate (5). Axonometric projection image.

FIG. 4 illustrates, in a preferred embodiment, a schematic diagram of a step of plating a metal tubular member. The flattening means (6) have roller-type center points which gradually increase in diameter for a smooth and efficient flattening process. Axonometric projection image.

FIG. 5 depicts a schematic diagram of the washing step of the preferred embodiment. The washing line (1) comprises first (8), second (9) and third (10) baths, vapor neutralizing means (11), drying means (12), lifting means (13). Axonometric projection image.

FIG. 6 shows a schematic diagram of the washing step of the preferred embodiment. Top view.

FIG. 7 depicts a schematic diagram of a preferred washing step of a preferred embodiment. Axonometric projection image.

FIG. 8 schematically illustrates a partially flattened metal plate (5) which is processed in the lamination line (3). Axonometric projection image.

FIG. 9 illustrates, in a preferred embodiment, a schematic diagram of means for holding metal plates (5). The metal plates (5) are arranged in the holding means (4) with spaces for effective washing. Axonometric projection image.

FIG. 10 illustrates the basic arrangement of a wash line comprising vapor collection devices.

PREFERRED {LIVING OPTIONS

Embodiments of the invention will hereinafter be described with reference to the drawings. However, the present invention is not limited to the embodiments disclosed herein and various modifications of the embodiments are possible.

In order that the embodiments of the invention may be illustrated in a clear and concise manner, elements not related to the embodiments of the invention will not be depicted in the drawings. In addition, identical or similar items have the same reference numbers wherever possible or practical. No less importantly, the dimensions of the elements are magnified or schematically illustrated, or some elements are not shown for clarity. The dimensions of each part may not reflect the true size of the elements.

The present invention provides a system and method for deactivating both internal and external metal tubular element surfaces. The purpose of the disclosed system and method is to provide means and steps for cutting, slabing and deactivating metal tubular members. The present invention is unique in its ability to cut, flatten, and decontaminate metal tubular elements in a completely safe manner without generating more difficult to dispose of radioactive residues. Here, radial, preferably hollow metal elements contaminated with radioactive particles will continue to be considered metal tubular elements.

In a preferred embodiment, the deactivation system comprises a cutting line (2) (see Fig. 1), a flattening line (3) (see Fig. 3), metal plate holding means (4) (see Fig. 7) and a washing line (2). 1) (see Fig. 5). After washing and drying, complete contamination control is performed on all radioactive particles (not shown in the drawings).

In a preferred embodiment of the invention, the washing line (1) comprises a first bath (8), a second bath (9) and a third bath (10), steam neutralizing means (11), drying means (12), lifting means (13) (see Figs. .5 and Fig. 6). The wash line further comprises means for holding the elements (8-13), line means, current source means, and standard machine coupling means for supplying, discharging, and controlling fluid, air, or vapor. It should be clear to a person skilled in the art that support, power supply, and connection means are standard production line arrangements that are laid out in accordance with the safety regulations applicable to the elements (8-13) and will not be described in detail herein. In addition, the number of baths (8-10) should not limit the scope of the present invention as it should be apparent to one skilled in the art that the washing process may be performed with at least one bath, but an additional number of baths may be utilized to achieve better process yields. . The cleaning processes are implemented with higher throughput, where the ultrasonic cleaning and rinsing steps are implemented in separate baths without the need to change the bath contents (acid solution, water, etc.). Tanks of sufficient capacity for holding liquids will continue to be kept here as baths.

In a preferred embodiment of the invention, the first bath (8) is a soaking bath (8), preferably made of non-oxidizing metals or metal alloys such as stainless steel. The soaking bath (8), which is filled with the first solution of the first concentration, is used for the initial wetting of the metal plates (5). In a preferred embodiment of the invention, the first first concentration solution is 100% water. It should be clear to one skilled in the art that the first bath (8) is not mandatory for this process and merely improves the efficiency of the cleaning process. Also, the scope of the present invention is not limited to water as the first solution of the first bath (8). Other liquids or solutions may also be added to the first bath (8).

In a preferred embodiment of the invention, the second bath (9) is a deactivation bath (9), preferably made of non-acid reactive materials. The decontamination bath (9) is filled with the second concentration of the second solution. In addition, the second bath (9) comprises ultrasonic wave generators (14) mounted such that the vector of generated waves is oriented parallel to the planes of the metal plates (5). In a preferred embodiment of the invention, the metal plates (5) placed in the holding means (4) in a vertical orientation are immersed vertically in the second bath (9). The ultrasonic wave generators (14) are located on the sides of the bath (see Fig. 10). The decontamination bath (9) may further include fluid inlet and outlet means, circulation means (16), filters (15), pumps (17), and controllers that enable the second bath (9) to be filled with the second solution and provide process control by filtering any residue. for a more efficient cleaning process. Also, these devices provide safe collection of radioactive particles in filtration units (15). The second bath (9) is hermetically sealed in the upper portion and the upper portion of the bath is connected to the vapor neutralization means (11). The second solution is heated and evaporated due to the mechanical energy absorption of the ultrasonic waves generated by the generators (14), which converts to the internal energy of the solution. It should be clear to a person skilled in the art that the present invention is not limited to the particular arrangement of the ultrasonic wave generators (14) and should not limit the scope of the present invention. The ultrasonic transducer, transducer power or frequency should be selected based on the capacity of the second bath (9) and the duration of the desired process. It should also be clear to one skilled in the art that the sealing means may be any standard sealing means which, in the preferred embodiment, has an airtight lid.

During ultrasonic cleaning, the contaminated residue separates from the surfaces of the metal plates (5) and sinks to the lower part of the second bath (9), while the acid solution vapor rises to the upper part of the second bath (9). For this reason, the circulation filtration system collects particles from the contaminated second solution through the lower portion of the second bath (9) by pumping the solution and filtering the solution through filtering capsules (15). The purified acid solution is then returned to the top of the second bath (9) via a circulating circuit (16), which is preferably a sealed conduit. Further, the contaminated vapor is directed to the vapor neutralizing means (11) where it is condensed, neutralized and filtered accordingly.

In a preferred embodiment of the invention, the vapor neutralization means (11) comprise vapor suction means; most preferably, an air pump hermetically connected to the upper part of the second bath (9). The vapor suction means are designed to extract contaminated vapors generated during the cleaning process in a second bath (9). The vapor neutralization means (11) further comprises condensing and neutralizing parts. In the neutralizing part, the contaminated vapor is mixed with sodium hydroxide. Only the neutralized condensate is released as a by-product and, if necessary, filtered to ensure that any radioactive residue is safely disposed of.

In a preferred embodiment of the invention, the filtering capsules (15) are mechanical fluid filtering capsules employing surface or deep filters that collect radioactive radicals from the second solution by passing a purified second solution. The filtration system may include more than one filtration capsule (15) for a better cleaning effect. However, the scope of the present invention is not limited to the filter capsules (15) as the only second solution filter means, nor is the scope of the present invention limited to the amount of said capsules (15). It should be clear to one skilled in the art that filtering capsules (15) are used in this system only for convenience in handling radioactive residues, since used filtering capsules (15) can be removed from the system and replaced with new capsules (15). The used capsules (15) are further disposed of as radioactive waste, for example by burial or storage.

In a preferred embodiment of the invention the second concentration of the second solution is 0.5-1.5% nitric acid solution. However, the present invention is not limited to the type or concentration of the second solution and it should be apparent to those skilled in the art that the second solution may be any solution which neutralizes radioactive radicals and the second concentration may be any concentration which is effective and . The high frequency mechanical waves propagating through the second solution along the planes of the metal plates affect the surfaces of the metal plates (5), purifying them of radioactive residues. So, this process is both chemical and mechanical cleaning.

In a preferred embodiment of the invention, the third bath (10) is a rinse bath (10), preferably made of non-oxidizing metals or metal alloys such as stainless steel. The rinse bath (10) comprises means for supplying a high pressure water stream. The current removes the acidic solution residue from the metal plates. The rinse bath (10) may further include rinse aid filtration means if absolutely necessary for complete safety.

In a preferred embodiment of the invention, the drying means (12) are high pressure air flow generators (12) which generate air gusts towards the metal plates (5) by drying the plates until the surface of the plates is free of adhering water. It should be clear to a person skilled in the art that the drying means (12) should not limit the scope of the present invention as they are used only as a process accelerator, since the metal plates (5) can dry without additional drying means.

In a preferred embodiment of the invention, the lifting means (13) comprises one or more hoists (13) attached to the holding means. The lifts (13) are adapted to move the cassettes (4) with the metal plates (5) from one element (810, 12) to another element in a fully automated manner. For this reason, the washing line (1) is fully automatic and does not require physical human interaction during the process, thus ensuring process safety and workers' health.

In a preferred embodiment of the invention, the cutting line (2) comprises pushing means (7) and cutting means (16). The cutting line (2) further includes standard means for holding, controlling and rotating the pushing means. These tools may include, but are not limited to: drives, turbines, generators, belts, gears, stands, bolts, nuts, power supplies, switches, and covers. In a preferred embodiment, the cutting means (16) is a sharp blade horizontally mounted inside the cutting line (2) on one side between the pushing means (7) (see Fig. 2). The blade (16) should be secured so that it can cut the metal tubular member along one side without physical contact with the pushing means (7). In a preferred embodiment, the pushing means are radially concave rollers (7) which are rotated continuously during the process (see Fig. 2) and of similar size. This new configuration enables continuous pipe cutting without creating chips or dust. The tube (7) inserted into one side of the cutting line (2) is retracted into the cutting line (2). The rotating rollers (7) press the tube against the blade with sufficient force to cut the tube along one side. In a preferred embodiment, the cutting line (2) comprises at least 10 pairs of rotating rollers (7), but the number of rollers should not limit the scope of the present invention as this process may be implemented with different number of rollers (7) until the pressing rollers (7) generate sufficient friction. to make the cut. The result of this line is a contaminated metal tubular member with one longitudinal cut along one side. It should be understood by those skilled in the art that the scope of the present invention is not limited to rotating rollers (7) as pushing means (7) and other means such as pistons are possible. Preferably, the blade is made of a solid material such as solid metal alloys, ceramics, synthetic diamonds, or other coating materials such as titanium coated blades.

In another embodiment of the invention, the cutting of the metal tubular member may also be accomplished by laser radiation, plasma jet or water jet. In all of these alternative flushing processes, a certain number of residues are generated, and appropriate filtration techniques must be adapted to ensure that the flushing process is safe.

It should be clear to a person skilled in the art that the cutting line (2) enables cutting of pipes of any length (5) since this process can be implemented on metal tubular elements (5) that are longer than the dimensions of the cutting line (2).

In a preferred embodiment of the invention, the plating line (3) comprises plating means (6) which are mounted on the machine so that the plating means (6) gradually expands the tube to the plate (see Fig. 8). The flattening line (3) further comprises standard control, support and torsion means for the flattening means (6). These tools may include, but are not limited to: drives, turbines, generators, belts, gears, stands, bolts, nuts, power supplies, switches, and covers. In a preferred embodiment, the plating means (6) is an expanding roller (6) having a diameter of the expanded portion of the expandable metal tubular member which gradually increases with each successive roller. All of these rollers are rotated continuously during the plating phase (see Fig. 4). The rollers intervene in the groove of the tubular member, widening and straightening said member as the diameter of the rollers increases. The partially expanded metal tubular member is pushed toward a subsequent roller having a wider cylindrical surface (blade) which further widens said member. The pushing is done by rollers that have already expanded the metal tubular member. The process continues until the tubular member is fully flattened (see Fig. 8). Such a new plating line (3) makes it possible to straighten a metal tubular member having only one longitudinal cut. In a preferred embodiment, the plating line (3) comprises 11 rollers (6), wherein the outer diameter of the cylindrical surface gradually increases from less than the cutting width to greater than the diameter of the straightened metal plate. However, the number of plating rollers (6) and the diameter of the expanding parts should not limit the scope of the present invention, since the same technical effect can be achieved with the variously arranged mechanically rotating expanding parts.

In a preferred embodiment of the invention, the plate holding means (4) is a cartridge (4), preferably made of a solid material having high mechanical and chemical resistance, such as stainless steel. The cartridge (4) contains metal plates (5) which are ready for the washing step. The metal plates (5) in the cassette are arranged parallel to each other in order to make the washing process more efficient and the solution flows to all surfaces of the plates. In addition, the metal plates (5) can be placed in the cassette (4) several heights (see Fig. 9). It should be clear to a person skilled in the art that the storage means (4) are not limited in their shape, size or configuration of the cartridge (4) and any storage device capable of accommodating the metal plates (5) is within the scope of the present invention.

In a preferred embodiment of the invention, the deactivation method comprises the steps of: cutting a tubular metal member along one side of the member; a tubular metal member being straightened to a metal plate (5); loading the metal plate (5) into the holding means (4); soaking the holding means (4) containing the metal plates (5); removing radioactive particles from the metal plates (5) during the washing step; management of canceled remains; flushing the remaining second solution from the holding means (4); drying the storage means (4) loaded with the metal plates (4); determining the radiation level of the metal plates (4); repeating the decontamination process if the level of security has not been reached.

In a preferred embodiment of the invention, the step of cutting the tubular metal member along one side of the member comprises feeding the contaminated tubular metal member to the cutting line (2), wherein the cutting line (2) cuts the member by machine-pressing the member along the cutting means. It should be clear to a person skilled in the art that the tubular metal member may be fed into the cutting line by a human or a robot. Also, the cutting tools can be sharp blade, laser beam, plasma jet or water jet. A combination of water jet and laser radiation is also possible.

In a preferred embodiment of the invention, the straightening step of the metal tubular member comprises feeding a contaminated tubular metal member with a longitudinal cut into a straightening line (3), where the straightening line (3) flattens the member gradually expanding it with the slabs (6).

In a preferred embodiment of the invention, the step of placing the straightened metal plates (5) in the holding means (4) comprises loading the metal plates (5) into the holding means (4) parallel to each other with fixed gaps between adjacent plates (5). The loading can be done by either a human or a robot.

In a preferred embodiment of the invention, the soaking step of the holding means (4) loaded with metal plates (5) comprises immersing the holding means (4) in a first bath (8) filled with a first solution. Immersion is accomplished by lifting means (13).

In a preferred embodiment of the invention, the washing step comprises removing radioactive particles from the metal plates (5) by immersing the receptacles (4) loaded with the metal plates (5) in a second bath (9) filled with the second solution. Immersion is accomplished by lifting means (13). The second bath (9) is hermetically sealed and ultrasonic waves are generated so that the wave vectors are directed along the planes of the metal plates (5).

The acid solution and the radioactive residue which has evaporated during the washing step must be properly disposed of. The wash tank has a tapered tapered bottom that is connected to a circular drainage system to effectively handle radioactive residues. The drainage system comprises one or more filtration devices which collect the residues with radioactive particles. Preferably, the filters are housed in a double walled stainless steel capsule that can be removed, sealed and used for long-term waste disposal. It should be clear to a person skilled in the art that the deposited residue may be further disposed of as radioactive waste, stored in storage or neutralized with appropriate solutions.

The acid solution evaporated from the second bath (9) is incorporated into the vapor neutralization means (11). In one embodiment, the vapor neutralization means (11) comprises a vacuum suction device which provides a spray of the alkaline solution. The sprayed alkaline solution droplets react with acidic vapors and neutralize them. This vapor management system may also include additional filtration devices to collect any particulate matter that may have entered the vapor composition.

In a preferred embodiment of the invention, during the remaining second solution removal step, the holding means (4) containing the metal plates (5) are placed in a third bath (10). Placement is accomplished by lifting means (13). The remainder of the second solution is cleaned of the metal plates (5) by rinsing the plates (5) with a high pressure water stream. The receptacles (4) are rotated and turned to the respective water flow so that all surfaces of the receptacles (4) and the metal plates (5) are properly cleaned. It should be clear to a person skilled in the art that residues of the second solution may be removed from the metal plates (5) by other standard methods of washing and rinsing such as re-immersion in water.

In a preferred embodiment of the invention, the step of determining the radiation level comprises determining the surface radiation level of the metal plates (5) by means of radiation measuring means such as a Geiger counter. It should be clear to one skilled in the art that the method of detecting radiation should not limit the scope of the present invention as it can be accomplished using a variety of known techniques, tools and systems that can qualitatively and / or quantitatively measure the radiation levels of metal plates. A clear advantage of the method of decontamination disclosed herein is that the metal plates (5) are fully straightened during the process, and a high degree of proximity is achieved during measurements. This provides an efficient, fast and reliable method of detecting beta particles over the entire surface of the metal plates (5).

In a preferred embodiment of the invention, the step of repeating the decontamination process if the level of safety is not achieved comprises comparing the measured radiation value with a predetermined value. If the measured value is higher than expected, the following steps are repeated: removal of radioactive particles from the metal plates (5) during the washing step; rinsing the remaining second solution of the receptacles containing the metal plates (5); re-setting the radiation level of the metal plates (5). The predetermined value, in the preferred embodiment, is measured in Severts or Gray and is the one that complies with security regulations. Thus, an element that has a value lower than the default radiation value is considered to be deactivated and an element having a higher radiation value than the default value is considered contaminated.

In a preferred embodiment of the invention, the drying step of the storage means (4) loaded with the metal plates (5) is performed prior to the determination of the radioactivity. However, to ensure process optimization, several metal plates may be subjected to intermediate measurements prior to the drying step while they are still contained in the container (4). Once the safety level has been reached, the container means (4) loaded with metal plates (5) are placed in the drying area by means of lifting means. The holding means (4) together with the metal plates (5) are then dried by means of drying means (12). The drying means (12) generates strong air currents which displace the water particles adhering to the surfaces of the metal plates (5). The plates are dried until no traces of water are visible on the metal plates (5). It should be clear to a person skilled in the art that drying agents (12) should not limit the scope of the present invention as they are only used as process catalysts, since the metal plates (5) could dry without additional drying agents.

Claims (20)

DEFINITION A method of deactivating the inner and outer surfaces of contaminated tubular metal elements, comprising the following steps: longitudinal cutting of tubular metal elements, straightening of slit tubular metal elements into metal plates, loading of metal plates into storage means, soaking of metal plates, washing of metal plates in an ultrasonic bath, determination of the level of radioactivity of metal plates making one longitudinal cut along one side of the tubular metal member in the cutting line (2); in that the straightening of the tubular metal members to the metal plates is accomplished by feeding the slotted tubular metal members into a lining line (3), wherein the metallic tubular member is gradually expanded and straightened along a longitudinal section by a plurality of roller-type slabs (6). 2. A method according to claim 1, wherein the step of cutting the tubular metal elements comprises pushing the tubular metal elements along the cutting means, wherein the cutting line comprises at least one of the following cutting means: sharp blade, laser beam cutter, plasma stream cutter or water jet. cutter. 3. A method according to claim 1, characterized in that the step of loading the metal plates (5) into the holding means (4) comprises placing the metal plates (5) parallel to one another in the holding means (4), leaving a gap between adjacent metal plates (5). ). 4. A method according to claim 1, characterized in that the soaking step of the metal plates (5) comprises immersing the receptacles (4) loaded with the metal plates (5) in a first bath (8) filled with the first solution. 5. A method according to claim 1, characterized in that the step of washing the metal plates (5) in an ultrasonic bath (9) comprises immersing the receptacles (4) loaded with the metal plates (5) in a second bath (9) filled with a second solution, wherein the second bath (9) is hermetically sealed and ultrasonic waves are generated such that the wave vectors are directed along the planes of the metal plates (5). 6. A method according to claim 1, characterized in that the step of washing the metal plates in an ultrasonic bath (9) further comprises extracting vapor from the second bath (9), wherein the acidic solution vapor is directed to the vapor neutralization means (11) a stream which reacts with and neutralizes the acid vapor, and the precipitated residue is filtered off with one or more filters. 7. The method of claim 1, wherein the step of washing the metal plates in an ultrasonic bath (9) further comprises circulating a second solution in the second bath (9), wherein the acidic solution is circulated through one or more filtration means (15) containing radioactive residues. filtered out. 8. The method of claim 1, wherein the method further comprises the step of washing away the remaining second solution from the holding means (4) loaded with metal plates (5), wherein the step comprises holding means (4), placing the metal plates (5) in a third bath (10), wherein the remainder of the second solution is cleaned of the metal plates using a high pressure water stream. 9. A method according to claim 1, characterized in that the step of determining the level of radioactivity of the metal plates (5) comprises measuring the radioactivity of the metal plates (5) using radiation measuring means. 10. The method of claim 1, wherein the method further comprises washing the metal plates in a second bath (9), washing in a third bath (10), and drying processes if the level of safety is not achieved. 11. The method of claim 5, wherein the first solution is pure water. 12. The method of claim 6, wherein the second solution is a solution of nitric acid in a concentration of 0.5% to 1.5%. 13. System for the decontamination of internal and external surfaces of contaminated tubular metal elements, comprising: washing line, cutting line, flattening line, holding means for holding elements during the washing step, characterized in that the cutting line (2) further comprises pushing means (7) and cutting means (16), wherein the pushing means (7) generates mechanical a force along the length of the tubular member, wherein the mechanical force is sufficient to cut the tubular member by pressing said member against the cutting means (16); wherein the plating line (3) further comprises a plurality of plating means (6) disposed in a progressively increasing diameter, wherein the plating means is applied to expand and straighten the tubular member j metal plate (5). 14. A system according to claim 13, characterized in that the cutting line (2) comprises at least one of the following cutting means: a sharp blade laser cutter, a plasma flow cutter or a water jet cutter. 15. The system of claim 13, wherein the washing line (1) further comprises a first bath (8), a second bath (9), a third bath (10), vapor neutralization means (11), acidic solution recirculation and filtration means (15), drying means (12) and lifting means (13). 16. A system as claimed in claim 13, characterized in that the means (4) for holding the metal tubular elements is a cartridge (4) adapted to fit a plurality of metal plates parallel to one another, leaving a gap between adjacent plates (5). 17. A system as claimed in claim 13, characterized in that the pushers (7) are radially concave rolls of a uniform size. 18. A system according to claim 13, characterized in that the flattening means (6) are cylindrical expanding rollers (6) with a gradually increasing diameter of the cylindrical expanding part. 19. The system of claim 15, wherein the second bath (9) is connected to at least one filtration means (15), wherein the filtration means is a filtration capsule (15); wherein the filtration capsule filters the pollution particles from the second solution by passing the purified second solution back to the second bath (9). 20. A system according to claim 19, characterized in that the filtering capsule (15) is a replaceable capsule which can be used to store collected contaminants in a radioactive waste repository.