JPH0812276B2 - Device for solidifying radioactive waste liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a device for solidifying radioactive waste liquid.

(Prior Art) In recent years, a plastic solidification method has been adopted for solidification treatment of radioactive waste liquid in a nuclear power plant because of its excellent solubility reduction of radioactive waste. 2 and 3
With reference to the drawings, a solidification device for radioactive waste liquid adopting a conventional plastic solidification method will be described. In FIG. 2, the radioactive waste liquid is stored in the radioactive waste liquid storage tank 1. The radioactive liquid waste introduced from the radioactive liquid waste storage tank 1 is dried and powdered by the dryer 2. This powdered radioactive waste liquid is passed through the powder transfer device 3 and the powder storage layer 4
And a certain amount of powder from the powder storage layer 4 is introduced into the mixing tank 6 via the powder transfer device 5 and the powder transfer pipe 5a. A thermosetting resin is introduced into the mixing tank 6 from a thermosetting resin tank 7 through a resin transfer pipe 8. Then, the thermosetting resin and the radioactive powder are mixed in the mixing tank 6. This mixture is first initiated by the polymerization initiator supplied from the polymerization initiator storage tank 9 via the first chemical injection pipe 10, and further from the polymerization accelerator storage tank 11 via the second chemical injection pipe 12. It is accelerated by the supplied polymerization accelerator. When the polymerization reaction is to be stopped for some reason, the polymerization inhibitor stored in the polymerization inhibitor storage tank 13 is supplied to the mixing tank 6 via the third chemical injection pipe 14. Then, the polymerized plastic mixture is filled in the drum can 15 and stored as radioactive waste.

In the above configuration, as a method for supplying the above-mentioned various drugs, generally, a pump for transfer is provided between the various drug storage tanks and the mixing tank. Here, FIG. 3 shows a schematic configuration diagram of a conventional drug supply device. In FIG. 3, the same parts as those in FIG. 2 are designated by the same reference numerals, and the description of the configuration will be omitted. Further, since the polymerization initiator, the polymerization accelerator, and the polymerization inhibitor have the same injection method, the transfer device for the initiator will be described below as an example, and the same parts as those of the other transfer devices will be denoted by the same reference numerals. The description is omitted. In FIG. 3, the polymerization initiator is introduced from the polymerization initiator storage tank 9 to the metering pipe 18 by the transfer pump 16 via the first automatically operated valve 17. At this time, the second automatic operation valve 19 provided downstream of the measuring pipe 18 is closed, and the third automatic operation valve 20 which is a three-way valve connects the measuring pipe 18 and the polymerization initiator storage tank 9 with each other. It has been configured. When the liquid level in the measuring pipe 18 rises and reaches a preset liquid level, it is detected by a liquid level gauge 21 provided in the measuring pipe 18, and the liquid level signal 21a closes the first automatic control valve 17. Then, the second automatically operated valve 19 is opened, and the third automatically operated valve 20 connects the metering pipe 18 and the inert gas supply device 22 to each other. As a result, the polymerization initiator in the measuring pipe 18 is pressure-fed by the inert gas and is supplied to the mixing tank 6 via the second automatic operation valve 19.
The supply of the polymerization initiator is completed when the flow of the inert gas is detected by the flow meter 23 provided between the inert gas supply device 22 and the third automatic operation valve 20. And
Each of the polymerization accelerator and polymerization inhibitor is supplied in a fixed amount to the mixing tank by the same method. The measuring pipe 18 is opened to the gas phase portion of the storage tank 9 from above in order to promptly introduce the drug into the measuring pipe 18 through the conducting pipe 24. Further, while each chemical is being supplied, the mixing tank is cooled by a refrigerant in order to suppress the progress of the polymerization reaction. This refrigerant is guided from the refrigerant storage tank 25 to the periphery of the mixing tank by the transfer pump 26 via the refrigerator 27, and then circulated so as to be guided to the refrigerant storage tank 5 again. Furthermore, the storage tank for the polymerization initiator is cooled by a refrigerant to maintain the quality of the polymerization initiator.

(Problems to be Solved by the Invention) In the above configuration, since the conventional radioactive waste liquid solidifying device has a complicated structure, a lot of labor is required for maintenance of the equipment. Further, each drug storage tank is installed in the radiation controlled area, and the self-confidence of the drug is a dangerous substance, so not only the replenishment work of the drug solution is restricted, but also many secondary wastes are generated.

Therefore, as shown in FIG. 4, an example in which only the storage tank is installed in the radiation non-controlled area is shown. Here, FIG. 4 shows an improved example of the conventional example of the apparatus for solidifying radioactive waste liquid shown in FIG. In FIG. 4, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description of the structure of those parts will be omitted. Fourth
In the figure, since the chemical injection pipe 10 for guiding the chemical liquid from the storage tank 9 to the mixing tank is longer than in the conventional case, a large amount of the chemical remains in the pipe. Then, the chemicals staying in this pipe may be deteriorated due to insufficient cooling. Therefore, in order to prevent the deterioration of the medicine, the medicine injection pipe
A circulation line 28 for guiding the drug accumulated in the storage tank 9 from 10 is provided via a control valve 29. Therefore, the space for these pipes is increased as compared with the conventional example, and a large amount of space is required.

However, in the current electronic power plants, it is desired to make each device compact, and a simpler and compact apparatus for solidifying radioactive waste liquid has been desired.

In view of the above circumstances, an object of the present invention is to obtain a compacting device for radioactive waste liquid which is compact and has excellent maintainability.

[Structure of Invention]

(Means for Solving Problems) In order to achieve the above-mentioned object, in the present invention, a thermosetting resin, a polymerization initiator, and a polymerization accelerator are sequentially mixed with each other after the radioactive waste liquid is dried and powdered to form a plastic. When a solidification product is formed and the polymerization reaction is to be stopped, the storage tank for each of the polymerization initiator, the polymerization accelerator, and the polymerization inhibitor is thermoset in the radioactive waste liquid solidification device that is supplied with the polymerization inhibitor. The resin, the polymerization initiator, the polymerization accelerator, and the polymerization inhibitor are arranged above the mixing tank for mixing, and above each of the storage tanks, a supply tank corresponding to each medicine is arranged in the radiation non-controlled area. , The replenishment tank and each of the storage tanks are connected by a chemical solution supply pipe without an upward gradient, and the chemical solution is injected without an upward gradient through a chemical solution measuring device that measures the storage tank and the mixing tank with a measuring pipe. Provided is a solidification device for radioactive waste liquid, which is characterized by being connected by a pipe.

(Operation) In the solidification device for radioactive waste liquid configured in this way, various chemical tanks are placed above the mixing tank, and various chemicals are guided to the mixing tank by natural flow and pressure feeding with an inert gas. Therefore, the transfer pump, which is a dynamic device, can be eliminated, the maintainability can be improved, and the facility utilization rate can be improved due to the reduction of the pump space. Further, since the medicine can be replenished within the radiation non-controlled area, no secondary waste is generated and the workability of the worker can be improved.

Embodiment An embodiment of the present invention will be described below with reference to FIG. Here, FIG. 1 shows a system diagram showing a main part of the apparatus for solidifying radioactive waste liquid of the present invention. In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description of the structure of those parts will be omitted. Also, since the same injection method is used together with the polymerization initiator, the polymerization accelerator, and the polymerization inhibitor, the transfer device before the start of polymerization will be described as an example, and the same parts as other transfer devices will be denoted by the same reference numerals. , The description is omitted. The polymerization initiator is led from the polymerization initiator storage tank 9 to a measuring pipe 18 arranged below the polymerization initiator storage tank 9 via a first automatically operated valve 17. At this time, a second automatically operated valve provided downstream of the measuring pipe 18
19 is closed, and a third automatically operated valve 20 which is a three-way valve connects between the metering pipe 18 and the polymerization initiator storage tank 9. When the liquid level in the measuring pipe 18 rises and reaches a preset liquid level, it is detected by the liquid level gauge 21, and the liquid level signal
The first automatically operated valve 17 is configured to be closed by 21a. Next, the second automatically operated valve 19 is opened, and the third automatically operated valve 20 is electrically connected between the measuring pipe 18 and the inert gas supply device 22. As a result, the polymerization initiator in the measuring pipe 18 is
A flow meter 23, which is supplied to the mixing tank 6 disposed further below 18 and is provided between the inert gas supply device 22 and the third automatic operation valve 20, detects the flow of the inert gas. This completes the supply of the polymerization initiator.

The polymerization initiator storage tank 9, the polymerization accelerator storage tank 11, the polymerization inhibitor storage tank 13 and the mixing tank 6 are connected to the first to third drug injection pipes 10, 12 and 14 for transferring various drugs. In order to transfer to the mixing tank without a pump, there is no upward slope. Further, in order to replenish the polymerization initiator storage tank 9 with the polymerization initiator, after the required amount of the polymerization initiator is put into the polymerization initiator replenishment tank 31 in the radiation non-controlled area, When the automatic operation valve 32 on the downstream side is opened, the polymerization disclosure agent is replenished into the polymerization initiator storage tank 9 via the flow meter 33. At this time, when the replenishment of the polymerization initiator is completed by the detection of the flow meter 33, the polymerization initiator replenishment completion signal 33a is transmitted from the flow meter 33, and the automatic operation valve 32 is closed.

In order to transfer the polymerization initiator replenishment tank 31 and the chemical solution replenishment pipe 34 connecting the polymerization initiator storage tank 9 to the polymerization initiator storage tank without a chemical transfer pump,
It is configured so that there is no upward slope.

Further, the polymerization initiator storage tank 9 is provided with a liquid level gauge 35. In order to prevent excessive replenishment of the chemical liquid, when the liquid level of the polymerization initiator storage tank 9 is a certain value or more, the liquid level gauge 35 is provided.
A control signal 35a is transmitted from the control signal 35a to control the automatic operation valve 32 of the chemical liquid supply pipe 34 so as not to open.

With the above configuration, the radioactive waste liquid solidifying device according to the present invention becomes more compact by eliminating the transfer pump, and the facility utilization rate can be improved. Furthermore, since the upward gradient of the various chemical injection pipes can be eliminated and the pressure feeding by the inert gas can be carried out as in the conventional case, various chemicals can be surely injected into the mixing tank. In addition, since the equipment is compact and the number of dynamic equipment is reduced, the maintainability can be further improved. In addition, since the chemical solution can be replenished in the radiation non-controlled area,
Work can be facilitated without the generation of secondary waste.

〔The invention's effect〕

According to the present invention, various chemical liquid tanks are arranged above the mixing tank, the transfer pump is removed, and the chemical liquid is transferred by the natural flow of the liquid and the pressure feed by the inert gas.
The solidification device for radioactive waste liquid can be made compact and the facility utilization rate can be improved. Furthermore, since the number of dynamic devices has been reduced, the maintainability can also be improved. Further, since the medicine can be replenished within the radiation non-controlled area, no secondary waste is generated and workability can be improved.

[Brief description of drawings]

FIG. 1 is a schematic system diagram showing a main part of a solidification device for radioactive waste liquid according to an embodiment of the present invention, FIG. 2 is a schematic system diagram showing a conventional solidification device for radioactive waste liquid, and FIG. 3 is a conventional radioactive liquid. FIG. 4 is a schematic system diagram showing various chemical liquid transfer devices provided in the waste liquid solidifying device, and FIG. 4 is a schematic system diagram showing an improved example of the radioactive waste liquid solidifying device shown in FIG. 6 ... Mixing tank, 7 ... Thermosetting resin tank 8 ... Resin transfer pipe, 9 ... Polymerization initiator storage tank 11 ... Polymerization accelerator storage tank, 13 ... Polymerization inhibitor storage tank 17 ... 1 automatic operation valve, 18 ... measuring pipe 19 ... second automatic operation valve, 20 ... third automatic operation valve 21 ... level gauge, 22 ... inert gas supply device 31 ... start of polymerization Reagent supply tank, 33 ...... Flow meter 34 ... Polymerization initiator supply pipe

Claims (1)

[Claims] 1. When a radioactive waste liquid is dried and powdered, a thermosetting resin, a polymerization initiator and a polymerization accelerator are sequentially mixed to form a solidified body of plastic, and a polymerization inhibitor is added when the polymerization reaction is stopped. In the apparatus for solidifying the radioactive waste liquid to be supplied, the storage tank for each of the polymerization initiator, the polymerization accelerator, and the polymerization inhibitor is mixed with the thermosetting resin, the polymerization initiator, the polymerization accelerator, and the polymerization inhibitor. A replenishment tank is provided above the storage tank, and a corresponding replenishment tank for each drug is placed above the storage tank in the radiation non-controlled area. A solidification device for radioactive waste liquid, characterized in that it is connected by a pipe, and the storage tank and the mixing tank are connected by a liquid medicine injection pipe having no upward gradient through a liquid medicine measuring device for measuring with a measuring pipe.