JP6479335B2 - Cleaning system and cleaning method for in-drum cement solidification device - Google Patents

Description

  Embodiments of the present invention relate to a cleaning system and method for an in-drum cement solidification device.

  In nuclear related facilities, waste liquid concentrated radioactive waste liquid and radioactive waste such as radioactive powdered resin and granular resin are generated. These radioactive wastes, for example, are mixed with cement and water and filled in a solidified container to form a cement solidified body, which is then buried in the ground for disposal.

  There are an in-drum type and an out-drum type as a method of producing such a cement solidified body. The in-drum type is a method in which radioactive waste, cement and water are kneaded by a cement mixer or the like in a solidification container such as a drum can, and the mixture is solidified as it is in the solidification container. The out-drum type is a method in which radioactive waste, cement and water are kneaded in advance using a kneading apparatus or the like, and the obtained kneaded product is filled from the kneading apparatus into a solidification container and solidified.

  In the method of producing a solidified cement, cement paste containing radioactive material adheres to the cement mixer and the kneading apparatus after cement kneading, and before the cement paste hardens on the surface of the cement mixer and the kneading apparatus. It is necessary to remove the cement paste.

  Therefore, in the case of an out-drum cement solidification apparatus, a configuration provided with a cleaning mechanism is employed. (For example, refer to patent documents 1 and 2.)

  Here, the in-drum type cement solidification device has the advantage that the device is simple and the amount of washing water for removing cement paste can be reduced compared with the out-drum type, and is widely used. ing. The adhesion of the cement paste to the cement mixer used in such an in-drum cement solidification device depends on the properties of radioactive waste, such as the viscosity of the cement paste, and so on. In the solidification device, the cement mixer is manually cleaned.

JP-A-2-176499 JP-A-7-120595

  However, in the case of manually cleaning the cement mixer, there is a problem that the work load on the workers is high. In addition, it is desirable to reduce the amount of cleaning wastewater that is a secondary waste.

  The present invention has been made to solve the above-described problems, and in the cleaning of the in-drum cement solidification device, the cleaning work load can be reduced, and the amount of generated cleaning wastewater as a secondary waste It is an object of the present invention to provide a cleaning system of an in-drum cement solidification device capable of reducing the

One aspect of the cleaning system of the in-drum cement solidification device according to the present invention is a cleaning system for cleaning an in-drum cement solidification device comprising a mixer for kneading radioactive waste, water and cement in a solidification container. A washing tank having a cylindrical shape with a bottom, and having an upper opening for inserting the mixer from above, and capable of storing washing water therein; and the washing tank under the mixer. A moving mechanism for moving to a washing position and a standby position, and a plurality of washing nozzles provided in the washing tank, for moving with the washing tank to jet the washing water into the washing tank to wash the mixer A solid-liquid separation container for storing washing wastewater discharged from the washing tank and separating the washing wastewater into solid content and washing water; discharging the washing wastewater from the washing tank and delivering it to the solid-liquid separation container To wash And the water pump, characterized by comprising a cleaning water supply pump for supplying the washing water separated in the solid component in the solid-liquid separation vessel to said cleaning nozzle. The washing nozzle moves horizontally with the washing tank and sprays the washing water into the washing tank at the washing position to wash the mixer .

One aspect of the cleaning method of the in-drum cement solidification device according to the present invention is a cleaning method for cleaning an in-drum cement solidification device including a mixer for kneading radioactive waste, water, and cement in a solidification container. A cleaning tank moving step of moving the cleaning tank and the cleaning nozzle from the standby position to the cleaning position; a mixer lowering step of lowering the mixer and accommodating the cleaning tank; rotating the mixer in the cleaning tank The shower water is stored in the washing tank by performing the shower washing step after the shower washing step and the shower washing step of spraying the washing water from the washing nozzle toward the mixer while moving up and down. After the immersion cleaning step of immersing and rotating the mixer, and the immersion cleaning step of rotating the mixer while discharging the cleaning wastewater stored in the cleaning tank after the immersion cleaning step. Characterized by comprising a waste water discharge step.

  According to the cleaning system and the cleaning method of the in-drum cement solidification device of the embodiment, it is possible to reduce the work load of the worker at the time of the mixer cleaning. In addition, the amount of secondary waste generated can be reduced.

It is a schematic block diagram which shows the structure of the in-drum type cement solidification apparatus provided with the mixer which is washing | cleaning object of embodiment. It is a systematic diagram showing roughly the composition of the cleaning system of the in-drum type cement solidification device of an embodiment. It is a flow figure showing the cleaning method using the cleaning system of the in-drum type cement solidification device of an embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram schematically showing a configuration of an in-drum cement solidification device 10 to be cleaned in the present embodiment. The in-drum type cement solidification device 10 includes a solidification container 11 for filling radioactive waste, a solidification material measuring tank 12 for storing cement which is a solidification material, and a mixer 13 for kneading contents in the solidification container 11. The mixer hood 14 is provided to prevent the contents of the solidification container 11 from scattering outside the solidification container 11 at the time of kneading.

  The solidification process of the radioactive waste using the in-drum type cement solidification device 10 is performed, for example, as follows. Radioactive waste is filled in the solidifying container 11, and cement is put into the solidifying container 11 from the solidifying material measuring tank 12. Further, water is introduced, and then the contents of the solidification container 11 are kneaded by the mixer 13. After kneading, the mixer 13 is taken out of the solidification container 11 and the kneaded material in the solidification container 11 is solidified. The solidification container 11 after taking out the mixer 13 is sent out of the in-drum cement solidification device 10 by the moving mechanism 22, for example, and conveys the new solidification container 11 into the in-drum cement solidification device 10.

  FIG. 2 is a system diagram schematically showing a configuration of the cleaning system 20 of the in-drum cement solidification device of the present embodiment. The cleaning system 20 includes a cleaning tank 21 which is used in the in-drum cement solidification device 10 and accommodates and cleans the mixer 13 to which the kneaded material containing the solid content S adheres, and a moving mechanism 22 which moves the cleaning tank 21. ing. The washing tank 21 is provided with a washing nozzle 23 for jetting washing water.

  Furthermore, the cleaning system 20 of the in-drum cement solidification device is provided with a solid-liquid separation container 24 that stores the cleaning wastewater generated in the cleaning tank 21 and separates it into the solid content S and the cleaning water L. The solid-liquid separation container 24 is connected to the washing nozzle 23 by a washing water supply pipe 25. A wash water supply pump 26 for supplying the wash water L in the solid-liquid separation container 24 to the wash nozzle 23 is interposed in the wash water supply pipe 25. On the upstream side of the washing water supply pump 26, a valve V1 such as an open / close valve is interposed. Further, a filter 27 for capturing the solid content S in the washing water L may be interposed in the washing water supply pipe 25.

  The solid-liquid separation container 24 is connected to the drainage port 21 c provided at the lower end of the side wall of the cleaning tank 21 by the cleaning wastewater transfer pipe 28. A valve V2 is inserted in the vicinity of the connection between the cleaning wastewater transfer pipe 28 and the cleaning tank 21. Further, in the washing wastewater transfer pipe 28, a washing wastewater pump 29 for transferring the washing wastewater in the washing tank 21 into the solid-liquid separation container 24 is interposed. A valve V3 is inserted on the upstream side of the washing waste water pump 29 of the washing waste water transfer pipe.

  As described above, in the cleaning system 20 of the in-drum cement solidification device, the cleaning water L in the solid-liquid separation container 24 is supplied to the cleaning tank 21 by the cleaning water supply pipe 25 and the cleaning wastewater generated in the cleaning tank 21 is It is configured to be sent to the solid-liquid separation container 24 by the washing wastewater transfer pipe 28.

  The moving mechanism 22 transports the washing tank 21 placed at the standby position to the washing position below the mixer 13 after carrying out the solidified container 11 after the kneading from the solidifying device 10. Further, the cleaning tank 21 used for cleaning is transported to the standby position. In order to move both the solidification container 11 and the washing tank 21 by the moving mechanism 22, the washing tank 21 should be of the same size and shape as the solidification container 11, for example, a drum having an inner volume of about 200 L Is preferred.

  The cleaning tank 21 has a bottomed cylindrical shape and has an upper opening 21 a for inserting the mixer 13 from above. The inner bottom surface 21b of the cleaning tank 21 is preferably formed in an inclined shape which is inclined toward the drainage port 21c of the cleaning wastewater. The inclined shape is preferably, for example, a conical shape in which the center of the inner bottom surface 21b is convex. Although depending on the shape and size of the mixer 13, the inclination angle of the inclined shape is about 5 to 15 degrees. In this embodiment, it is approximately 10 degrees. As a result, the solid content S (adhesion) washed from the mixer 13 can be effectively discharged from the washing tank 21 together with the washing water L without staying in the washing tank 21.

  As the cleaning nozzle 23, it is possible to use a straight forward nozzle which jets high pressure water straight and a fan shaped nozzle which jets high pressure water fan-like. The mounting hole 30 can be installed in, for example, a wall surface of the cleaning tank 21, and the cleaning nozzle 23 can be attached to the cleaning tank 21 via the mounting hole 30. If such an attachment method is adopted and a large number of attachment holes 30 are installed in the cleaning tank 21 in advance, the number of the cleaning nozzles 23 and the installation position can be appropriately changed according to the type, shape and the like of the mixer 13. Also, for example, by using a ball joint or the like for connecting the mounting hole 30 and the cleaning nozzle 23, the cleaning nozzle 23 can be attached to the cleaning tank 21 at a desired angle, or the attachment angle can be attached variably. It is.

  The upstream end of the washing water supply pipe 25 has a suction pipe (not shown) for sucking the washing water L in the solid-liquid separation container 24. The suction pipe is located below the water level of the flush water L. The suction pipe has a piping structure connected to the cleaning water supply pipe 25 using, for example, a swivel joint equipped with a float so that the suction pipe is located near the water surface of the cleaning liquid L even when the water level of the cleaning liquid L changes. Is preferred.

  A branch pipe 31 is connected in the vicinity of the outlet of the solid-liquid separation container 24 of the flush water supply pipe 25. A valve V4 is inserted in the branch pipe 31. Further, a valve V5 is connected to the upstream side of a connection point of the flush water supply pipe 25 with the branch pipe 31, and a valve V6 is interposed downstream thereof.

  The branch pipe 31 is a pipe for sucking in air when draining water in the pipe of the cleaning system 20 of the in-drum type cement solidification device. The end of the branch pipe 31 is located above the water surface of the washing water L so as not to be in contact with the liquid surface of the washing water L in the solid-liquid separation container 24.

  A first bypass pipe 32 for bypassing the cleaning water supply pump 26 is connected to the cleaning water supply pipe 25. A valve V7 is inserted in the first bypass pipe 32.

  The downstream end of the cleaning wastewater transfer pipe 28 is used for solid-liquid separation in order to drain the air in the piping of the cleaning system 20 of the in-drum cement solidification device in the solid-liquid separation container 24. It is installed above the water surface of the washing water L in the container 24 so as not to contact the washing water L.

  In addition, a second bypass pipe 33 that bypasses the cleaning wastewater pump 29 is connected to the cleaning wastewater transfer pipe 28. In the second bypass pipe 33, a valve V8 is inserted.

  The washing water supply pipe 25 and the washing wastewater transfer pipe 28 are connected by a washing tank bypass pipe 34 which bypasses the washing tank 21. The cleaning tank bypass pipe 34 is connected to the cleaning water supply pipe 25 via a valve V9 such as a three-way valve.

  The solid-liquid separation container 24 is, for example, a bottomed cylindrical container and has an upper opening. The upper opening is preferably provided with a hood 35 for preventing splashing of return water into the solid-liquid separation container 24. The hood 35 preferably has, for example, a structure having a drive mechanism of a counterweight system, in order to be able to be moved up and down easily. Thereby, replacement | exchange of the solid-liquid separation container 24, and conveyance can be performed easily. In addition, it is preferable that the washing water supply pipe 25, the branch pipe 31, and the washing wastewater discharge pipe 28 be movably installed according to the elevation of the hood 35. Thereby, exchange etc. of solid-liquid separation container 24 can be performed more easily. For example, by using a drum having a capacity of 200 L as the solid-liquid separation container 24, the cleaning system 20 of the in-drum cement solidification device can be simplified.

  In addition, the cleaning system 20 of the in-drum cement solidification device includes the control unit 36 that controls the operation of the mixer 13, the moving mechanism 22, the cleaning water supply pump 26, the cleaning wastewater pump 29, and the valves V1 to V9. And each process in the cleaning method of the in-drum type cement solidification device mentioned below is automatically performed by control of control part 36.

  Next, a cleaning method using the cleaning system 20 of the in-drum cement solidification device of the present embodiment will be described. FIG. 3 is a flowchart of the cleaning method of the present embodiment. The cleaning method of the present embodiment includes a cleaning tank moving step S1, a mixer lowering step S2, a cleaning step S3 and a cleaning wastewater discharging step S4. The cleaning step S3 includes a shower cleaning step S31 and an immersion cleaning step S32. Moreover, you may have the water removal process S5 as needed after washing wastewater discharge process S4.

  The mixer 13 used for kneading in the solidifying device 10 of FIG. 1 is extracted from the solidifying container 11 by a lift mechanism (not shown). After the solidification container 11 is discharged from the lower side of the mixer by the moving mechanism 22, the cleaning tank 21 disposed at the standby position by the moving mechanism 22 is transported to the cleaning position below the mixer 13 (washing tank moving step S1). In a state where the washing water supply pump 26 and the washing wastewater pump 29 are stopped, the mixer 13 is lowered by the raising and lowering mechanism to be accommodated above the washing tank 21 (mixer lowering step S2).

  In the cleaning step S3, the valve V9 is switched to the cleaning nozzle 23 side. Also, the valves V1, V5 and V6 are open, and the valves V2, V3, V4, V7 and V8 are closed. With the washing waste water pump 29 stopped, the washing water supply pump 26 is operated to supply the washing water L in the solid-liquid separation container 24 to the washing nozzle 23 through the washing water supply pipe 25.

  The washing water is pressurized by the washing water supply pump 26 and jetted from the washing nozzle 23 to wash the mixer 13 (shower washing step S31). At this time, the solid content S (adhered substance) adhering to the mixer 13 can be effectively cleaned by rotating and vertically moving the mixer 13. Cleaning wastewater generated by the cleaning is stored in the cleaning tank 21. When the water level of the washing wastewater in the washing tank 21 rises, the mixer 13 is lowered to immerse the washing water L in the washing tank 21 while rotating the mixer 13 (immersion washing step S32). When the whole of the mixer 13 is immersed in the washing water L in the washing tank 21, the injection of the washing water L may be stopped. Furthermore, the mixer 13 may be moved up and down in the washing wastewater by the elevating mechanism. Thereby, the deposit | attachment of the mixer 13 can be wash | cleaned effectively.

  Next, the washing wastewater discharging step S4 is performed. If the mixer 13 is moved up and down, stop it as necessary, switch the valve V9 to the cleaning tank bypass pipe 34, open the valves V2 and V3, and close the valves V1 and V4 to V8. Do. The washing water supply pump 26 is stopped and the washing wastewater pump 29 is operated to transfer the washing wastewater in the washing tank 21 into the solid-liquid separation container 24. At this time, the mixer 13 is kept rotating. In the solid-liquid separation container 24, the solid content S in the washing wastewater is precipitated, and the washing wastewater is separated into the solid content S and the washing water L.

  Here, when the mixer 13 is rotated, the solid content S in the washing wastewater is easily collected near the center of the washing tank 21 by the vortex flow. When the inner bottom surface 21b of the cleaning tank 21 is formed in a conical shape, the solid content S can be moved in the direction of the inner wall of the cleaning tank 21, so that these can be effectively discharged.

  The washing water L separated in the solid-liquid separation container 24 can be reused by being supplied to the washing nozzle 23 by the washing water supply pump 26.

  After the washing wastewater in the washing tank 21 is discharged in the washing wastewater discharging step S4, the water removing step S5 is performed as necessary. In the water removing step S5, the washing water L remaining in the piping constituting the washing system 20 of the in-drum cement solidification device is discharged into the solid-liquid separation container 24 together with the solid content S. Thereby, it can suppress that solid content S solidifies in piping and causes clogging of piping. The water removing step S5 includes a step S51 for draining water in the washing water supply pipe 25, the washing wastewater transfer pipe 28 bypassing the washing wastewater pump 29, and the second bypass pipe 33, and a washing bypassing the washing water supply pump 26. Step S52 for draining water in the water supply pipe 25, the first bypass pipe 32 and the washing waste water transfer pipe 28, and the step for draining the washing water supply pipe 25, the washing waste water transfer pipe 28 and the washing tank bypass pipe 34 There are three steps with S53. One of steps S51 to S53 may be performed alone, or two or more steps may be performed in combination. The combination and order of these can be changed as appropriate depending on the piping to be drained.

  In step S51, the wash water supply pump 26 is operated and the wash wastewater pump 29 is stopped. The valve V9 is switched to the cleaning tank bypass pipe 34 side, the valves V1, V4, V6 and V8 are opened, and the valves V2, V3, V5 and V7 are closed. As a result, the air in the upper part of the solid-liquid separation container 24 is sucked through the branch pipe 31, and the washing water supply pipe 25, the washing tank bypass pipe 34, the washing wastewater transfer pipe 28 bypassing the washing wastewater pump 29; The bypass pipe 33 is vented, and the washing water L remaining inside and the solid content S contained in the washing water L are delivered into the solid-liquid separation container 24.

  In step S52, the wash water supply pump 26 is stopped and the wash wastewater pump 29 is operated. The valve V9 is switched to the cleaning tank bypass pipe 34 side, the valves V3, V4, V6 and V7 are opened, and the valves V1, V2, V5 and V8 are closed. As a result, the air in the upper part of the solid-liquid separation container 24 is sucked through the branch pipe 31, and the wash water supply pipe 25 and the first bypass pipe 32, which bypassed the wash water supply pump 26, the wash tank bypass pipe 34, The washing wastewater transfer pipe 28 is vented, and the washing water L remaining therein and the solid content S contained therein are delivered into the solid-liquid separation container 24.

  In step S53, both the washing water supply pump 26 and the washing wastewater pump 29 are operated. The valve V9 is switched to the cleaning nozzle 23 side, the valves V1, V2, V3, V4 and V6 are opened, and the valves V5, V7 and V8 are closed. As a result, air is sucked from the upper opening of the washing tank 21, and the washing water supply pipe 25, the washing tank bypass pipe 34 and the washing waste water transfer pipe 28 are ventilated, and the washing water L remaining in the inside is contained therein. The solid content S is delivered into the solid-liquid separation container 24.

  In the cleaning method of the present embodiment, the operation of each device in the cleaning tank moving step S1, the mixer lowering step S2, the cleaning step S3, the cleaning wastewater discharging step S4 and the water removing step S5 is automatically performed by the control unit 36. Can.

  The operating states of the first and second pumps and the switching or opening / closing states of the valves V1 to V9 in the cleaning step S3, the cleaning wastewater discharge step S4 and the water draining steps S51 to S53 are shown in Table 1.

  As described above, according to the cleaning system and method of the in-drum cement solidification device of the present embodiment, the cleaning of the mixer of the in-drum cement solidification device of radioactive waste, the discharge of the cleaning wastewater from the cleaning tank, and the piping The process up to draining can be performed automatically. Therefore, the workload of mixer cleaning can be reduced. In addition, since the washing waste water is used as washing water, the amount of secondary waste generated can be reduced.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

  DESCRIPTION OF SYMBOLS 10 ... In-drum type cement solidification apparatus, 11 ... Solidification container, 12 ... Solidification material measurement tank, 13 ... Mixer, 14 ... Mixer hood, 20 ... Cleaning system of in-drum type cement solidification apparatus, 21 ... Cleaning tank, 21a ... Upper part Opening, 21b: inside bottom surface, 21c: drainage port, 22: moving mechanism, 23: washing nozzle, 24: solid-liquid separation container, 25: washing water supply pipe, 26: washing water supply pump, 27: filter, 28: washing Waste water transfer pipe, 29: washing waste water pump, 30: mounting hole, 31: branch pipe, 32: first bypass pipe, 33: second bypass pipe, 34: washing tank bypass pipe, 35: hood, 36: control Part, L: washing water, S: solid content, S1: washing tank moving step, S2: mixer lowering step, S3: washing step, S4: washing wastewater discharging step, S5, S51, S52, S53: water removing step, V1 V9 ... valve.

Claims (8)

A cleaning system for cleaning an in-dram cement solidification device comprising a mixer for kneading radioactive waste, water and cement in a solidification container, comprising:
A bottomed cylindrical cylindrical washing tank having an upper opening for inserting the mixer from above and capable of storing washing water therein;
A moving mechanism for moving the cleaning tank to a cleaning position and a standby position below the mixer;
A plurality of washing nozzles provided in the washing tank, moving horizontally with the washing tank, spraying the washing water into the washing tank at the washing position, and washing the mixer;
A solid-liquid separation container for storing washing wastewater discharged from the washing tank and separating the washing wastewater into solid content and washing water;
A washing wastewater pump for discharging the washing wastewater from the washing tank and delivering it to the solid-liquid separation vessel;
And a washing water supply pump for supplying the washing water separated from the solid content in the solid-liquid separation vessel to the washing nozzle.   The cleaning system of an in-drum cement solidification device according to claim 1, wherein the moving mechanism is a conveyor for loading the cleaning tank.   The cleaning system of an in-drum cement solidification device according to claim 1 or 2, wherein the moving mechanism has a roller for loading the cleaning tank.   The cleaning system of the in-drum cement solidification device according to any one of claims 1 to 3, wherein an inner bottom surface of the cleaning tank is formed in a conical shape. A washing tank moving step of moving the washing tank from the standby position to the washing position by the moving mechanism;
A mixer lowering step of lowering the mixer and accommodating the mixer in the washing tank from the upper opening;
A shower cleaning step of operating the washing water supply pump while rotating and moving the mixer up and down to spray the washing water from the washing nozzle toward the mixer;
An immersion cleaning step of immersing and rotating the mixer in the cleaning water stored in the cleaning tank by performing the shower cleaning step after the shower cleaning step;
After the immersion cleaning process, the cleaning wastewater pump is operated while rotating the mixer to discharge the cleaning wastewater stored in the cleaning tank, and the cleaning wastewater discharging process introduced into the solid-liquid separation container; ,
The in-drum cement according to any one of claims 1 to 4, further comprising: a control unit that controls the moving mechanism, the mixer, the washing water supply pump, and the washing wastewater pump so as to perform Solidifier cleaning system.   The cleaning system for an in-drum cement solidification device according to any one of claims 1 to 5, wherein the cleaning tank has a plurality of mounting holes for mounting the cleaning nozzle.   The said solid-liquid separation container is comprised from the bottomed cylindrical container which has an upper opening, and it comprises the hood which covers the said upper opening so that opening and closing is possible. Cleaning system for drum cement solidification equipment. A cleaning method for cleaning an in-dram cement solidification device comprising a mixer for kneading radioactive waste, water and cement in a solidification container, comprising:
A washing tank moving step of moving the washing tank and the washing nozzle from the standby position to the washing position;
A mixer lowering step of lowering the mixer and accommodating the washing tank;
A shower cleaning step of spraying cleaning water from the cleaning nozzle toward the mixer while rotating and moving the mixer in the cleaning tank;
An immersion cleaning step of immersing and rotating the mixer in the cleaning water stored in the cleaning tank by performing the shower cleaning step after the shower cleaning step;
A cleaning wastewater discharge step of discharging the cleaning wastewater stored in the cleaning tank while rotating the mixer after the immersion cleaning step;
A method of cleaning an in-drum cement solidification device, comprising:

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