Liquid radioactive waste injection system

Abstract

A system is disclosed for introducing liquid radioactive waste into a vitrification melter, which vitrifies the radioactive waste. [Solution] A liquid radioactive waste injection system according to an embodiment of the present invention injects liquid radioactive waste into a vitrification melting furnace that vitrifies the radioactive waste, and may include a waste storage tank that stores the liquid radioactive waste, and a waste injection device that receives the liquid radioactive waste from the waste storage tank and injects the supplied liquid radioactive waste into the vitrification melting furnace.

Description

[Technical Field]

[0001] The present invention relates to a system for feeding liquid radioactive waste into a vitrification melter, which vitrifies the radioactive waste. [Background technology]

[0002] The stable treatment, storage, and management of waste, especially hazardous waste such as radioactive waste, is a very important issue. Among the methods of waste treatment and storage, the use of glass to treat waste is called vitrification, which is a method of permanently isolating radioactive waste, sludge, contaminated soil, or industrial waste by enclosing it in a glass structure to prevent it from seeping into the surrounding environment.

[0003] In general, a waste vitrification device melts a glass-forming agent and waste in a melting furnace to vitrify the waste, exhausts volatile components in the waste through an exhaust treatment process, and applies heat to toxic substances such as radionuclides and heavy metals so that they become part of a glass network structure. A residence time is given until a homogeneous molten glass mixture is formed, and the glass melt is then discharged to form a vitrified body.

[0004] There are various types of melting furnaces depending on the heating method, and among them, the cold crucible induction melter (CCIM) mainly consists of a cylindrical melting chamber with electrical insulators inserted between multiple metal sectors through which cooling water circulates, and a high-frequency induction coil installed on the outside of the melting chamber. The high-frequency current applied to the induction coil melts the materials (e.g., waste and glass) inside the melting chamber.

[0005] When the radioactive waste is fed into the melting furnace, it must be fed evenly, otherwise the melting of the radioactive waste in the melting furnace will be uneven. Summary of the Invention [Problem to be solved by the invention]

[0006] Meanwhile, an important operational technology in radioactive waste treatment involves mixing water with initially dried solid or sludge-like radioactive waste to produce a liquid, which is then stably and quantitatively fed into a glass melting furnace at over 1,000°C to vitrify. In particular, the various types and large amounts of secondary waste generated in the process of treating radioactively contaminated water generated during the cooling of the reactors at the Fukushima nuclear power plant in Japan are all temporarily stored in metal containers in the form of sludge. Among the methods for stably treating this waste, vitrification technology is attracting the most attention.

[0007] The problem to be solved by the present invention is to provide a liquid radioactive waste injection system that converts sludge and the like into liquid radioactive waste and inputs the liquid radioactive waste into a vitrification melting furnace.

[0008] The objects of the present invention are not limited to those mentioned above, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] To achieve the above object, a liquid radioactive waste injection system according to an embodiment of the present invention injects liquid radioactive waste into a vitrification melting furnace that vitrifies the radioactive waste, and may include a waste storage tank that stores the liquid radioactive waste, and a waste injection device that receives a supply of the liquid radioactive waste from the waste storage tank and injects the supplied liquid radioactive waste into the vitrification melting furnace.

[0010] The waste storage tank may include an agitator to mix the liquid radioactive waste.

[0011] The waste charging device may include a charging pipe for charging the liquid radioactive waste into the vitrification melting furnace, a cooling pipe that contacts the charging pipe and through which cooling water flows to cool the charging pipe, and a housing that surrounds and accommodates the charging pipe and the cooling pipe.

[0012] The cooling pipe may include an inlet portion at one side through which the cooling water is drawn in and an outlet portion at the other side through which the cooling water is discharged.

[0013] The waste charging device may further include a connecting pipe connecting the inlet and the outlet, and the connecting pipe and the cooling pipe may form a closed cooling water circuit for circulating and flowing the cooling water.

[0014] The cooling water can be discharged to the outside through the discharge portion.

[0015] The input tube may be located in a central portion of the housing.

[0016] The system may further include a peristaltic tube pump that supplies the liquid radioactive waste from the waste storage tank to the waste input device.

[0017] When the vitrification melting furnace includes a solid radioactive waste supply pipe, the waste input device is attached to the supply pipe and can input the liquid radioactive waste into the vitrification melting furnace through the supply pipe.

[0018] Specific details of other embodiments are included in the detailed description and drawings. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a liquid radioactive waste injection system that can stably supply liquid radioactive waste to a vitrification melting furnace. [Brief explanation of the drawings]

[0020] [Figure 1] 1 illustrates a liquid radioactive waste input system according to an embodiment of the present invention. [Figure 2] 1 is a diagram showing a waste injection device of the liquid radioactive waste injection system of the present invention. FIG. [Figure 3] 1 is a diagram showing a waste injection device of the liquid radioactive waste injection system of the present invention. FIG. [Figure 4] 1 is a diagram showing a waste injection device of the liquid radioactive waste injection system of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Best Mode for Carrying Out the Invention The present invention provides a liquid radioactive waste injection system for injecting liquid radioactive waste into a vitrification melting furnace that vitrifies the radioactive waste, the system including a waste storage tank for storing the liquid radioactive waste, and a waste injection device for receiving the liquid radioactive waste from the waste storage tank and injecting the supplied liquid radioactive waste into the vitrification melting furnace.

[0022] MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Advantages and features of the present invention, as well as methods for achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be realized in various different forms. These embodiments are provided solely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art to which the present invention pertains. The present invention is defined solely by the scope of the claims. The same reference symbols refer to the same elements throughout the specification.

[0023] Hereinafter, a liquid radioactive waste injection system according to an embodiment of the present invention will be described.

[0024] FIG. 1 is a diagram showing a liquid radioactive waste injection system according to an embodiment of the present invention, and FIGS. 2 to 4 are diagrams showing a waste injection device of the liquid radioactive waste injection system according to the present invention.

[0025] Referring to FIG. 1, a liquid radioactive waste injection system 10 according to an embodiment of the present invention injects liquid radioactive waste into a vitrification melting furnace that vitrifies the radioactive waste, and may include a waste storage tank 100 that stores the liquid radioactive waste, and a waste injection device 200 that receives the liquid radioactive waste from the waste storage tank 100 and injects the supplied liquid radioactive waste into the vitrification melting furnace.

[0026] The radioactive waste vitrification facility is a facility that processes radioactive waste more safely. It can not only dramatically reduce the volume of medium and low level radioactive waste, but also minimize the leakage of radioactive materials into the surrounding area in any environment, thereby significantly improving the safety of radioactive waste processing.

[0027] Radioactive waste vitrification equipment not only fundamentally blocks radioactive materials from leaking into the environment by combining radioactive waste with a glass structure, but also revolutionarily reduces the volume of radioactive waste. Vitrification technology can reduce the initial volume of all combustible and non-combustible medium- and low-level radioactive waste generated at nuclear power plants to less than 1 / 20. This not only ensures the safety of radioactive waste disposal, but also greatly contributes to the stable promotion of disposal projects for the construction of management facilities.

[0028] The radioactive waste vitrification equipment can vitrify radioactive waste through the following process.

[0029] Glass raw materials are placed in an induction-heated vitrification melting furnace, where the glass is melted using heat induced by an electromagnetic field. Once a glass melt of approximately 1100°C is produced, crushed waste stored in the radioactive waste storage area is fed to the glass melt via a radioactive waste feeder, where it decomposes on the glass melt, with the radioactive materials firmly bonding with the glass components. Combustible waste that can be treated in an induction-heated vitrification melting furnace includes workers' clothing, gloves, shoes, and paper waste, as well as low-radioactivity waste resin used for water purification at nuclear power plants.

[0030] Once in the glass structure, radionuclides cannot escape under any environmental conditions. The strength of the bond between the glass structure and radionuclides has been confirmed by internationally recognized leaching tests.

[0031] The waste storage tank 100 is for storing radioactive waste, and the waste storage tank 100 constituting the liquid radioactive waste injection system 10 according to an embodiment of the present invention is capable of storing liquid radioactive waste.

[0032] The waste storage tank 100 may include an agitator 110 to agitate and mix the liquid radioactive waste contained therein. The agitator 110 may be composed of a shaft to which power is transmitted and blades that perform agitation. That is, when the shaft rotates due to external power, the blades attached to the shaft rotate, mixing the liquid radioactive waste within the waste storage tank 110. As a result, the waste contained in the liquid radioactive waste can be evenly dispersed in a liquid phase and stored within the waste storage tank 100. The liquid radioactive waste stored in the waste storage tank 100 is supplied to the waste input device 200 via supply pipes 105 and 107 and a peristaltic pump 300, etc.

[0033] 1-3, a liquid radioactive waste injection system 10 according to an embodiment of the present invention may include a waste injection device 200.

[0034] The waste injection device 200 injects the liquid radioactive waste supplied from the waste storage tank 100 into the melting furnace. To this end, the waste injection device 200 may include an injection pipe 210 for injecting the liquid radioactive waste into the vitrification melting furnace, a cooling pipe 220 in contact with the injection pipe 210 and through which cooling water flows to cool the injection pipe 210, and a housing 201 for surrounding and accommodating the injection pipe 210 and the cooling pipe 220.

[0035] The input pipe 210, the cooling pipe 220, and the housing 201 may be made of a corrosion-resistant material so as not to be corroded by radioactive waste or other waste materials and the outside air. Preferably, the input pipe 210, the cooling pipe 220, and the housing 201 may be made of stainless steel.

[0036] The input pipe 210 can function as a flow path for the liquid radioactive waste to move through. One side of the input pipe 210 can be connected to the waste storage tank 100 and the supply pipes 105 and 107, and the other side can be connected to a vitrification melting furnace.

[0037] That is, when waste is supplied from the waste storage tank 100, it is transferred to a peristaltic tube pump 300 via a first supply pipe 105. The liquid radioactive waste injection system 10 according to an embodiment of the present invention may include a peristaltic pump 300, which can supply the waste at a constant rate to the waste injection device 200. The waste supplied from the peristaltic pump 300 is supplied to an input pipe 210 of the waste injection device 200 via a second supply pipe 107. The input pipe 210, which has received the waste, can inject the waste into a melting furnace.

[0038] The temperature inside the input pipe 210 of the waste input device 200 may rise to 600 to 1,000°C depending on the waste being transferred. Since overheating of the input pipe 210 may cause deformation of the waste input device 200 or the waste, it is necessary to cool the inside and outside of the input pipe 210. For this purpose, the waste input device 200 may include a cooling pipe 220.

[0039] The cooling pipe 220 is disposed in the housing 201 so as to be in contact with the input pipe 210 so as to supply cold to the input pipe 210. By disposing the cooling pipe 220 and the input pipe 210 so as to be in contact with each other, the cooling pipe 220 can transfer cold to the input pipe 210 and cool the input pipe 210.

[0040] Cooling water flows through the cooling pipe 220 to cool the input pipe 210. To this end, the cooling pipe 220 may include an inlet 221 through which the cooling water is drawn in and an outlet 223 through which the cooling water is discharged. The cooling water flowing into the inlet 221 moves along the inlet pipe 225 and exchanges heat with the input pipe 210, thereby cooling the input pipe 210.

[0041] The cooling water moves along the discharge pipe 226 connected to the inlet pipe 225 , exchanges heat with the input pipe 210 , and is discharged to the outside of the cooling pipe 220 through the discharge part 223 .

[0042] For example, cooling water at 100°C and a pressure of 5 bar is drawn in through inlet 221, passes through cooling pipe 220, and exchanges heat with input pipe 210, thereby cooling input pipe 210. The cooling water that has exchanged heat with input pipe 210 is discharged to the outside of cooling pipe 220 through outlet 223.

[0043] At this time, the cooling water discharged to the outside of the cooling pipe 220 through the discharge part 223 is drained to the outside of the waste feeding device 200. That is, the cooling water is not reused but is drained and discharged to the outside of the waste feeding device 200. In this case, new cooling water must be continuously supplied from the outside.

[0044] 4, the waste input device 200 may further include a connecting pipe 250 connecting the inlet 221 and the outlet 223. As a result, the connecting pipe 250 and the cooling pipe 220 may form a closed cooling water circuit that circulates and flows the cooling water.

[0045] In this case, a heat exchanger (not shown) including a cooling cycle for cooling the cooling water that has absorbed heat from the input pipe 210 may be located in the flow path of the connecting pipe 250. The heat exchanger on the connecting pipe 250 allows the cooling water to be adjusted to a state required for cooling the input pipe 210. For example, the cooling water that has passed through the heat exchanger may be adjusted to a state of 5 bar and 100°C required for cooling the input pipe 210.

[0046] 3 and 4, the input pipe 210 may be located in the center of the housing 201. By locating the input pipe 210 in the center, the connection position can be smoothly determined and managed when connecting to the melting furnace.

[0047] The liquid radioactive waste injection system 10 according to the embodiment of the present invention can be connected to and installed in a vitrification melting furnace. More specifically, the waste injection device 200 of the liquid radioactive waste injection system 10 can be installed in the melting furnace to inject liquid radioactive waste into the melting furnace.

[0048] For example, if the vitrification melting furnace includes a solid radioactive waste supply pipe (not shown), the waste input device 200 can be attached to the solid radioactive waste supply pipe and the liquid radioactive waste can be input into the vitrification melting furnace through the supply pipe. That is, the vitrification melting furnace can receive the supply of liquid radioactive waste through the liquid radioactive waste input system 10 according to an embodiment of the present invention without installing a separate liquid supply pipe. Therefore, according to the present invention, liquid radioactive waste can be treated using the structure of an existing melting furnace.

[0049] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art will understand that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the above-described embodiment is illustrative in all respects and is not limiting.

Claims

1. In a system in which liquid radioactive waste is fed into a vitrification melting furnace that vitrifies the radioactive waste, a waste storage tank for storing the liquid radioactive waste; a waste injection device that receives the liquid radioactive waste from the waste storage tank and injects the liquid radioactive waste into the vitrification melting furnace; and a peristaltic tube pump that supplies the liquid radioactive waste from the waste storage tank to the waste input device; The waste input device is an injection pipe for injecting the liquid radioactive waste into the vitrification melting furnace; a cooling pipe that contacts the input pipe and through which cooling water flows to cool the input pipe; a housing that surrounds and houses the input pipe and the cooling pipe; The cooling pipe includes an inlet portion at one side through which the cooling water is drawn in and an outlet portion at the other side through which the cooling water is discharged, The waste input device further includes a connecting pipe connecting the inlet and the outlet, The connecting pipe and the cooling pipe form a closed cooling water circuit that circulates and flows the cooling water, A heat exchanger for cooling the cooling water that has absorbed heat from the input pipe is located in the flow path of the connecting pipe, The heat exchanger adjusts the cooling water to a predetermined temperature and pressure; the waste storage tank includes an agitator to mix the liquid radioactive waste; A liquid radioactive waste injection system, characterized in that the injection pipe is located in the center of the housing.

2. When the vitrification melting furnace includes a solid radioactive waste supply pipe, 2. The liquid radioactive waste injection system according to claim 1, wherein the waste injection device is attached to the supply pipe and injects the liquid radioactive waste into the vitrification melting furnace through the supply pipe.

Images