JPS59162492A - Method and device for solidifying radioactive waste - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a solidification treatment device for radioactive waste generated in nuclear power generation facilities, and in particular, the present invention relates to a solidification treatment device for radioactive waste generated in nuclear power generation facilities, and in particular, a method for solidifying waste by using a powder solidification agent made of an inorganic material. It is suitable for application to things that undergo assimilation treatment.

[Prior art]

A device that assimilates radioactive waste by filling it into a single-material solidification container such as a P-C container (polymer-impregnated concrete container) and using a solidification agent such as special water glass. is proposed.

These solidification devices had the following drawbacks.

α) Since the solidifying agent in powder form is handled, there is a high possibility that troubles such as clogging of the piping of the solidifying agent supply system or solidifying agent sticking to the piping etc. will occur.

(2) In order to prevent the above-mentioned troubles, the shape of the solidifying agent tank, the slope of the assimilating agent supply piping, etc. are restricted.

(3) In addition to the assimilate tank, it is necessary to provide a weighing tank and weighing equipment for weighing the solidified material. Furthermore, accurate weighing is impossible due to adhesion of the solidifying agent to the inner surface of the weighing tank. In particular, when the solidifying agent is made of an inorganic material such as special water glass, the ratio of the 11ml solidifying agent to the added water (water mixing ratio) is determined by the fluidity of the solidifying agent paste after crosstalk (0,5 It is difficult to produce a solidified material with uniform physical properties using conventional methods, as it is difficult to produce a solidified material with uniform physical properties due to the difference in fluidity, which affects the water permeability and strength of the assimilated material after hardening. Met.

For reference, Figure 1 shows the relationship between the water content in the solidifying agent paste and the fluidity of the solidifying agent paste, and Figure 2 shows the relationship between the assimilate strength and the hot water rate in the solidifying agent paste. These data (-1L are for when special water glass is used in Tachikawa as a one-time punishment.

[Purpose of the invention]

The purpose of the present invention is to fill a solidification container with radioactive waste,
When solidifying waste using a powdered solidifying agent, if the powdered assimilating agent blocks pipes or tanks,
Alternatively, a method and apparatus for solidifying radioactive waste that can prevent the solidifying agent from sticking to them, enable accurate weighing of the assimilating agent, and always produce solidified bodies with homogeneous physical properties. Our goal is to provide the following.

[Summary of the invention]

The present invention is characterized in that radioactive waste generated in nuclear power generation facilities is solidified using a solidifying agent, in which a certain amount of powdered solidifying agent is packaged in advance and then supplied to an assimilation agent kneading tank. The solidifying agent paste is kneaded with added water in the kneading tank, and the solidifying agent paste is injected into the solidifying container to produce a solidified body of radioactive waste.

[Embodiments of the invention]

FIG. 3 shows an example of a solidification treatment system using a powdered solidification agent. As shown in the figure, the large amount of waste is first temporarily stored in a waste storage tank 2, and then weighed in an appropriate amount by a waste weighing hopper 3 and filled into a solidification container 1. Further, the powdered assimilating agent is supplied to the solidifying agent tank 4 and temporarily stored therein. This raw material powder is fed from a solidifying agent tank 4 to a solid metering tank 6 through a rotary feeder 5. In the tank 6, the amount received is managed by the load cell/L'9. The additive water for one-sided formation is supplied from the water supply system to the additive water measuring tank 8 and weighed. The weighed powder assimilate agent and added water are led to a solidifying agent mixing tank 7, and after being mixed, are poured into a solidifying container 1 filled with waste. As mentioned above, such a system has the following problems.

(1) Problems with clogging or sticking of solidifying agent supply piping or valves occur. Next, since the solidifying material is in powder form,
When moisture is present, the powders adhere to each other and form granules, which can lead to blockage of pipes.

(2) It is difficult to accurately weigh the powder solidifying agent. That is, for the reason (1), the solidifying agent adheres to the measuring tank 6 and the inner wall of the piping, making accurate weighing difficult.

The solution of the present invention to the above problems will be explained below.

FIG. 4 is a flowchart of an assimilation processing system according to the present invention. Thereafter, this solidifying agent package 10 is transported to the kneading tank 7 by the solidifying agent package transportation equipment 11 in an amount necessary for solidifying. The added water is supplied to the added water measuring tank 8, the amount of water corresponding to the weight of the solidifying agent is measured, and the amount of water is measured to be equal to the weight of the solidifying agent.
transported to.

The one-sided conversion container 1 is carried into a solidification facility and set in an assimilation treatment device. The waste shaped into pellets is stored in a waste storage tank 2, and then sent to a waste weighing tank 3, where the container 4 has a capacity 7 corresponding to the amount to be filled into the container 4.
The bond is weighed and filled into the solidification container 1.

Next, after injecting the solidifying agent paste (k) kneaded in the kneading tank 7 into the container 1 filled with waste, the container 1 is covered with a lid 12, and the solidifying agent paste t-
The solidified material is then carried out after being cured after applying a post-pull 1 nong 13 and the like to be injected.

The above is an explanation of the pellet solidification method for assimilating pellet-shaped waste.11 Even when the present invention is applied to a homogeneous solidification method, the processing steps IJi waste filling and solidifying agent paste injection are simply interchanged. However, there is no change in the handling of assimilates and solidified materials.

Similarly, the cage material for making the powder solidifying agent into a cage is water-soluble polyvinyl alcohol,
Alternatively, it is preferable to select a cellulose-based material. The packaging material is in a small amount compared to the solidifying agent, and has no effect on the formation of the hardening agent or its physical properties.

As described above, in the present invention, an assimilation system using an inorganic powder assimilation agent can be easily realized by weighing the powder assimilation agent in advance to a certain extent and then packaging it. It is.

That is, in the present invention, even if a powdered solidifying agent made of an inorganic material is used, it is converted into a cage and sent to the kneading tank 7, so that an accurate amount of assimilating agent can be supplied at all times. It is possible to maintain the water mixing ratio of the assimilate paste in an optimum state.

First, a specific example of the configuration of the apparatus of the present invention will be explained with reference to FIG. This diagram shows a solidification process using an inorganic coagulant (special water glass) and filling an assimilation container made of an inorganic thin container (PIC, etc.) with waste formed into pellets. It shows the system.

First, an empty solidification container (thin-walled container made of inorganic material) 1 with a content of about f1707 is conveyed to the waste filling section by the empty container conveyor 21, and is moved to the filling cap 16 by the container elevator 23.
It is pushed up to the point where it is connected to. Further, the pellets temporarily stored in the waste storage tank 2 are maintained at about 60C by a heater 14. The pellets are guided to the waste weighing hopper 3, and in the weighing hopper 3, vibration is applied by the vibrator 15 to flatten the pellet level, and when the pellet level reaches a specified value, the level switch 25 is activated and the valve 26 is closed. Pellet weighing is complete. In this example, the vibration filling method is used to fill the pellets into the hopper 3, and the pellet filling capacity of the container is set to 110 tons by experiment.The pellets in the weighing hopper 3 after pellet weighing are The pellets are filled into the container 1. At this time, the pellets are somewhat powdered, so to prevent the generation of radioactive dust, a cap 16 and a gasket 27 are attached to the opening of the container 1 to ensure close contact with the container 1. Improving.

In addition, vent lines 2B and 3a are provided in the filling section, waste storage tank 2, and weighing hole 3, respectively, to maintain a weak negative pressure inside the container and prevent dust from dispersing. The pellets naturally filled into the container 1 due to gravity are removed by applying vibration to the container 24.
The pellet volume inside is set to 110 tons. At this time, the power of the vibrator 15 of the weighing hopper 3 and the vibrator 24 of the container 1 are made consistent.

Next, the solidifying agent side will be described. The raw material powder, which is an assimilation agent, is pre-measured and packaged in a certain amount before being delivered. When making a pack group, several types of feed, such as 10 kg and 5 kg, can be manufactured so that the amount of solidifying agent supplied can be finely adjusted. Further, as the solidifying agent package material, it is preferable to use polyvinyl alcohol, which has excellent water solubility.

The assimilating agent packages 10 are transported by a transport belt conveyor 17 to the solidifying agent kneading tank 7, in pieces of appropriate size, for example, IOK (the number of required solidifying agent packages will be described later together with the amount of water added).

The additive water for one-way conversion is supplied to the additive water measuring tank 8 from the supply system. In the measuring tank 8, the level switch 28
The amount of water is controlled and when it reaches a specified level (for example, 29 tons), the valve 29 is closed and the supply is stopped.

The mixing ratio of added water in the solidifying agent paste to be mixed is preferably set to 22.5% in view of the fluidity of the solidifying agent paste and the properties of the solidified product. The specific gravity of the solidifying agent paste with a hot water rate of 22j5% is 1.95, and the required injection volume into the container [170 tons] is 607 (11
7 becomes 9). This place.

The amount of solidifying agent paste is preferably set at approximately 130 to 96 degrees, taking into account the total amount of solidifying agent paste deposited on the wall surface of the tank. As a result, the weight of the solidifying agent is 9 in 100, so the solidifying agent is 10 packages of 9 in 10, and the amount of water added is 29 tons.

In the solidifying agent kneading tank 7, the solidifying agent and the added water are kneaded for a certain period of time, and after the mixing is completed, the solidifying agent paste is poured into the container 1 after filling with pellets. The injection amount is controlled by a level switch 30, and when the specified injection amount is reached, the valve 31 closes and stops the 1+ injection.

After the injection of pellets and solidifying agent paste is completed, the container 1 is lowered by the elevator 23, and the container lid 12 is attached to the lid.
It is attached to A20. Since an iron plate is embedded in the lid 12, it is attracted by the electromagnet 19 of the lid mounting machine 2o.

After the lid is attached, the container 1 is lifted up again by the elevator 23, and the solidifying agent paste remaining in the assimilating agent kneading tank 7 is injected into the void in the container 1 to perform post-filling.

At this time, set the level switch to 3 to prevent over 70.
o Manage the amount of injection.

After the post-filling is completed, the filling container conveyor 22
Transferred to curing facility.

The transfer of the assimilate package 10 to the assimilate kneading tank 7 will be explained in detail in FIGS. 6 and 7. The solidifying agent package 1o is transferred to the kneading tank 7 by a transfer belt conveyor 17, and a package input port 33 is provided in the kneading tank hi32. Inlet port 33 is spring 3
A door 34 having a number 5 is provided so as to be opened by the load of the package when the package is inserted. The door 34 is closed except when the package 10 is inserted, and prevents the assimilant paste from flying away during stirring of the solidifying agent. Further, the upper lid 32 is provided with a viewing window 39, an agitator motor 36, an added water inlet 37, and a level dial seat 38.

The effects of the above implementation sequence will be described below.

(1) By pre-packaging the raw material powder of the solidifying agent, it is possible to eliminate the need to handle the powder in the solidifying treatment system, thereby eliminating the need to handle the powder in the solidifying agent, preventing valve closing or sticking due to the solidifying agent. Also, it is possible to eliminate the occurrence of adhesion of by-products to the inner surfaces of tanks and various equipment. Therefore, it has become possible to assimilate waste using a container made of an inorganic material and a solidifying agent, making it possible to produce an amorphous assimilate with long-term stability.

(2) Since the raw material powder of the solidifying agent is measured and packaged in advance, the solidifying agent storage tank, assimilate measuring tank, and solidifying agent measuring equipment can be omitted, which improves economic efficiency, simplicity, and maintenance of the solidifying agent equipment. This improves performance and also makes operation and control easier.

(3) Since the raw material powder for the assimilating agent can be accurately weighed, it is possible to always produce a solidified material with uniform physical properties.

(4) When filling the solidification container 1 with pellets, the vibrator 24
Because of the vibration, the pellet filling rate was improved by about 10% compared to natural filling, and the volume reduction ratio was increased.

(5) Belt conveyor 1 for transporting assimilate package 10
7, it is no longer necessary to consider the slope of the transfer line (necessary when transferring by gravity).

In addition, a spring-loaded door 3 is installed at the package input port 33 of the kneading tank 7.
4, it is possible to prevent the paste from scattering from the immersion opening 33.

(6) Because the pellets are stored in the storage tank 2 at a temperature of 6 (l), when the solidifying agent paste is poured into the container 1, a protective film is formed on the pellets due to the temperature difference between the pellets and the paste. Since the water absorption rate of the pellets is reduced, cracks in the solidified product due to swelling of the pellets can be prevented.

(7) Polyvinyl aluminum as material for solidifying agent package
r-ru (using P, V, A l-(dolphin,
P, , V. Since humans are immersed in water, they are ideal as packaging materials.

〔Effect of the invention〕

As explained above, in the present invention, the raw material powder for the assimilation agent is packaged in a predetermined amount before being sent to the assimilation processing equipment, so that the assimilation agent in powder form is used. In a product that solidifies waste, it is possible to completely prevent the solidifying agent from clogging the powdered assimilating agent iE+, QW or tank, or from sticking to them, and thus to accurately weigh the assimilating agent. As a result, it is possible to produce an assimilate with uniform physical properties at all times.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the fluidity of assimilating agent paste with respect to solidifying agent water mixing ratio, Figure 2 is a green diagram showing the relationship between solidifying agent water mixing ratio and solidified solid strength, and Figure 3 is a diagram showing the relationship between solidifying agent water mixing ratio and solidified material strength. Fig. 4 is a diagram showing the flow of the assimilation processing system of the present invention, Fig. 5 is a system diagram showing an example of the solidification processing apparatus of the present invention, and Fig. 6 is a system diagram showing an example of the assimilation processing system using The figure is a schematic plan view illustrating in detail the means for transferring the assimilating agent package to the kneading tank and the groove structure of the lid of the solidifying agent kneading tank, and FIG. 7 is a longitudinal sectional view of FIG. 6. 1... Solidification container, 2... Waste (pellet) storage tank, 3... Bulk waste weighing hopper, 4... Assimilate tank,
5... Rotary feeder, 6... Solidifying agent measuring tank, 7... Solidifying agent kneading tank, 8... Added water measuring tank,
9...-Load cell, lO... Anabolic agent package, 1
1...Package transportation equipment, 12...Lid, 13...
- Post filling layer, 14... heater, 15...
Vibrator, 16... Filling cap, 17... Belt conveyor, 19... Electromagnet, 20... Lid attachment 1, 21... Empty container conveyor, 22... Filling container conveyor, 23 ... Elevator, 24... Vibrator, 25...
・Level switch, 26...Measuring hopper population valve, 27
...Patsukin, 28...Level switch, 29...
・Additional water supply valve, 30...Level switch, 31...
- Solidifying agent injection valve, 32... Kneading tank top cover, 33... Package inlet, 34... Inlet door, 35...
Spring, 36--Agitator motor, 37--Additional water inlet, 38--Level dial washer, 39--Peep window. Me 1 Flash Reiki a Water Sil Eternal Prison (%) Ji 30

Claims (1)

[Claims] 1. In a device in which radioactive waste generated in nuclear power generation equipment is solidified using an assimilating agent, a certain amount of powdered solidifying agent is packaged in advance and then placed in a solidifying agent kneading tank. The assimilating agent paste is supplied and kneaded with added water in the kneading tank to produce a solidifying agent paste, and the assimilating agent paste is injected into the solidifying container to produce a 1M radioactive waste product. Assimilation treatment method for radioactive waste. 2. The method for assimilating radioactive waste according to claim 1, characterized in that polyvinyl alcohol is used as a packaging material for packaging the powdered solidifying agent. 3. Store pellet-shaped waste at 60C in a waste storage tank.
The method for solidifying radioactive waste according to claim 1 or 2, characterized in that after heating the radioactive waste to an assimilation container, the solidifying agent paste is poured into the solidifying container. . 4. Claims 1 to 3, characterized in that the powder solidifying agent is an assimilating agent made of inorganic material such as special water glass.
A method for assimilating radioactive waste as described in any of the above. 5. In solidification processing equipment that solidifies radioactive waste generated in nuclear power generation facilities using a solidification agent, waste Jf! l
A waste storage tank for storing J, a waste measuring hopper connected to this storage tank, an added water measuring tank, an assimilating agent package in which a certain amount of powdered assimilating agent is packaged, and the added water needle an assimilating agent kneading tank communicating with the assimilating agent mixing tank, a pan cage transfer means for conveying the solidifying agent packages to the assimilating agent mixing tank, a solidifying container filled with the waste and solidifying agent paste, and an empty assimilating agent mixing tank. means for transporting empty containers into a solidification facility; means for communicating the assimilation containers carried into the solidification facility with the waste weighing hopper and the assimilation agent mixing tank; and waste and assimilation agent. 1. An apparatus for solidifying radioactive waste, comprising a filling container transfer means for transporting a solidifying container filled with paste. 6. The radioactive waste according to claim 5, characterized in that the waste is formed into pellets, and the waste storage tank is provided with a heater for heating the pellets. solidification processing equipment. 7. Radioactive waste as set forth in claim 6, characterized in that a vibrator is provided to shake at least one of the waste weighing hopper and the solidification container to vibrate the waste pellets. Material solidification processing equipment. 8. The radioactive waste solidification processing apparatus according to any one of claims 5 to 7, wherein the means for conveying the corporal cage and the solidification container are each a belt conveyor.