JPS61128197A - Method of treating radioactive spent ion exchange resin - 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 method for treating radioactive spent ion exchange resin generated from nuclear power plants, etc. The present invention relates to a method of granulating by adding an agent.

[Background of the invention]

BACKGROUND OF THE INVENTION The operation of nuclear power plants and other facilities generates waste fluids that contain radioactive substances, and these waste fluids are often treated using ion exchange resins. Disposal of radioactive spent ion exchange resin generated at this time is one of the issues in the operation of nuclear power plants. For example, in a boiling water nuclear power plant, the amount of radioactive waste generated is
It is dominated by used ion exchange resin.

Conventionally, used ion exchange resins have been stored as slurry in tanks, or mixed with a solidifying agent such as cement or asphalt, solidified in drums, and stored in facilities.

Recently, methods have been developed in which the used ion exchange resin slurry is turned into dry powder, the water that accounts for most of its volume is removed, and then solidified with a solidifying agent, or if necessary, it is made into pellets and stored for a predetermined period of time, and then an assimilated material is used. A method of solidifying the material is being considered.

It has been confirmed that this method can reduce the volume to a fraction of that of the method of directly solidifying the slurry with cement.

When granulating used ion exchange resin, JP-A-57-1
As shown in Japanese Patent No. 78194, there is a method of granulation using a thermoplastic resin or a rubber-like elastic polymer as a binder, but the use of a thermoplastic resin in this way causes the following problems.

■ When cleaning, it is necessary to use an organic solvent.
Care must be taken when handling.

■ 180 to 200 Ct when using thermoplastic resin
It needs to be heated.

■ Secondary waste (washing waste) is an organic solvent and must be handled with care.

It is desired to develop a binder that does not have the above-mentioned problems, that is, can be washed with water, can be processed at room temperature, and the resulting pellets have excellent weather resistance.

[Purpose of the invention]

The purpose of the present invention is to obtain pellets with excellent weather resistance and to ensure safe handling by adding a water-soluble binder, lubricant, and reinforcing agent to dry powder of radioactive used ion exchange resin and granulating it. An object of the present invention is to provide a method for treating radioactive used ion exchange resin with excellent properties.

[Summary of the invention]

The present invention provides a method for drying and pulverizing a used ion exchange resin slurry generated in a nuclear power plant and then granulating the water-soluble binder 1- 10% by weight and lubricant 0.5-5
% by weight and 5-20% by weight of reinforcing agent and then granulation, or add 1-10% by weight of water-soluble binder and 0.5-5% by weight of lubricant to the used ion exchange resin slurry. , is dried and powdered, and further reinforcing agent is added in an amount of 5 to 20% by weight.
A method for processing a used ion exchange resin, characterized by adding and granulating it.

[Embodiments of the invention]

The principle and idea of the present invention will be explained below.

When granulating used ion exchange resin, using a water-soluble binder can be easily done by washing or water, and handling of washing waste is relatively easy as no organic solvent is used. . The water-soluble binder has the property that it can fully exhibit its effect as a binder unless water is added thereto so that it can be sufficiently uniformly kneaded.

It is possible to create pellets that are

An example of a water-soluble binder is methylcellulose (MC)
, carboxymethylcellulose (CMC) polyvinyl alcohol (PVA), water? l Paraffin etc. can be used.

As the lubricant, liquid silicone, paraffin emulsion, wax emulsion, polyethylene precol (PEG), etc. can be used.

Cellulose fibers and the like can be used as reinforcing agents.

Next, the present invention will be explained in detail.

The method of adding the above-mentioned additives is shown in Figures 1 and 2.
As shown in the figure, there are two possible methods: adding additives after drying and pulverizing the used resin slurry, and adding additives to the used ion exchange resin slurry and then drying and pulverizing the slurry.

First, Figure 1 (when used ion exchange resin slurry is dried and powdered, various additives are mixed in, and then granulated)
This method will be explained in detail.

A water-soluble binder was added in a range of 0 to 20% by weight to a powder containing 0.5% by weight of a lubricant and 5% by weight of a strength reinforcing agent, and the weather resistance of the resulting pellet was tested in the air. The results shown as the rate of change in compressive strength after storage are shown in FIG.

As shown in the figure, the strength deterioration is due to the water-soluble binder at 1% by weight.
It was not observed above, and even when 10% by weight or more was added, 10
Since the effect is the same as in the case of 0 weight, the water-soluble binder is
It is preferably 1% by weight or more and 10% by weight or less.

Next, 0.5% by weight of water-soluble binder and 5% by weight of strength reinforcing agent.
The weather resistance was investigated when a lubricant was added to the powder by varying the amount from 0 to 10.0% by weight. Weather resistance was evaluated by compressive strength ratio (initial strength was set as 1). The results are shown in FIG. The lubricant content should be 0.5% by weight or more without any strength deterioration, and no significant effect is observed even if 5.0% by weight or more is added, so the addition rate of the lubricant should be 0.5% by weight or more. The content is preferably 5.0% by weight or less.

Next, 0.5% by weight of water-soluble binder and 0.5% by weight of lubricant.
The study was conducted by changing the amount of strength reinforcing agent from 0 to 25% by weight in the powder containing the following. The results are shown in FIG. If the strength required for the pellet strength is 1, the addition rate of the reinforcing agent must be 5% by weight or more to reduce dust, and even if 200% by weight or more is added, no significant effect is seen, so the addition rate of the reinforcing agent is 5%.
It is desirable that the weight percentage be 20% by weight or more and 20% by weight or less.

The preferred blending ratio of various additives is 100% by weight.
When closed, 1 to 10% by weight of water-soluble binder and 0 lubricant.
．． 5-5% by weight, reinforcing agent 5-20% by weight, water 15% by weight
That's all. The amount of water added in this formulation must be such that the above-mentioned ingredients can be sufficiently uniformly mixed and additives such as binders can be uniformly distributed. As the amount of water-soluble binder added increases, the amount of water required increases. Furthermore, since the maximum water content that can be granulated is approximately determined by the granulation method, it is necessary to limit the amount of water added depending on the granulation method.

Furthermore, the pellet of ion exchange resin has a property of easily absorbing moisture due to the nature of the ion exchange resin, so the higher the initial moisture content, the less it absorbs moisture. From the above, the water content is 15% by weight or less within the range that can be granulated, and in the case of a priketing machine, the water content is 40% by weight or less.

Next, regarding the method shown in Figure 2 (in which additives (water-soluble binder and lubricant) are mixed into the used ion exchange resin slurry, it is dried and powdered, and a reinforcing agent is further mixed in and granulated). explain. The preferred blending ratio of various additives is 1 to 15% of the water-soluble binder when the resulting powder is ioo:i%.
wt%, lubricant 0, 5-5 wt%, reinforcing agent 5-20''J
IL generation%.

Next, specific examples will be described using the drawings.

<Example 1> This embodiment is shown in FIG.

A 10% by weight ion exchange resin slurry 1 is dried and powdered from a supply tank 2 in a dryer 3, and then filled into a powder hopper 4. 50 kg of dry powder resin was put into the kneading tank 5 from the powder hopper 4, 14 KIi of liquid silicone 7 as a lubricant was added from the additive tank 6, and 3.3 kg of methylcellulose as a binder and reinforcing agent were added from the additive tank 8. 12Kg9 of cellulose fiber was added to water 9o from the added water tank 10.
After Kllt 1 is added to the kneading tank 5, it is kneaded into the minions for 5 minutes. At the same time, the pressed chevron-shaped granulator 13 is filled with #1 and 200 g, and granulated using a cutter 1.4. The prepared pellets are filled into a container 15.

The pellets produced in Example 1 showed no deterioration in strength during storage in the atmosphere for one month, and were excellent in weather resistance. The test results are shown in Figure 7.

According to this example, since a water-soluble binder is used,
There is an advantage that the kneading tank 5 and the granulator 13 can be washed with water.

<Example 2> This embodiment is shown in FIG.

A 10% ion exchange resin slurry 1 from a supply tank 2 is dried and powdered in a dryer 3, and then filled into a powder hopper 4. Dry powder resin 50Kz from powder hopper 4
into a kneading tank 5, 1.4 liters of liquid silicone 6 as a lubricant from an additive tank 6, 3.3 KIi of methylcellulose as a binder and 12 liters of cellulose fiber as a reinforcing agent from an additive tank 8. Added water 10 to 12
After each Kfl 1 is added to the kneading tank 5, it is kneaded into the minions for 5 minutes. Next, the mixed material is supplied to the preketting machine 16 and granulated. The created beret is in container 15
is filled with.

The pellet made in Example 1 did not show any strength deterioration during storage in the atmosphere for one month and had excellent weather resistance, but the pellet made in Example 2 also showed poor weather resistance. I was able to create an excellent beret.

<Example 3> In Example 2, a priquetting machine was used as the granulator, but the same method can be used even if a tablet machine is used, but in this case, the amount of added water is reduced to 30 KI.
Make it l. The pellet thus produced can also have excellent weather resistance, similar to the pellet produced in Example 1.

<Example 4> Example 4 is shown in FIG. 9. To a feed tank 2 containing a 10% by weight ion exchange resin slurry 1 are added methyl cellulose 1 OKq9 as a binder from an additive tank 16 and liquid silicone 1,5 Kf7 as a lubricant from an additive tank 6. The thoroughly kneaded mixture is supplied to a dryer 3 and pulverized.

The produced powder enters the powder hopper 4, and from the powder hopper 4, 50~ is measured by the load cell 12 and cut into the kneading tank 5. Cellulose fibers 17 serving as reinforcing materials are cut out from the additive tank 18 to 5 and 9 to the mixing tank 5, and are mixed. The mixed powder is granulated by a preketting machine 19 and filled into a container 15.

The pellets produced in Example 4 also have excellent weather resistance.

Modifications> Examples 1 to 4 all show examples in which used ion exchange resin is dried and powdered and made into pellets as is. If the ion exchange group is decomposed and then subjected to a treatment such as pelleting, it is possible to create pellets with even better weather resistance.

〔Effect of the invention〕

According to the present invention, when granulating used ion exchange resin into pellets, a water-soluble binder is used, so washing can be performed with water, and granulation can be performed at room temperature. It has excellent handling properties and can be safely granulated.

Additionally, since it contains a lubricant with excellent weather resistance, a reinforcing agent, and water in a certain proportion, it has the effect of making a pellet with excellent weather resistance.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 respectively show the basics 70- of the method of the present invention.
Figure 3 is a diagram showing the relationship between the addition rate of water-soluble binder and the rate of change in compressive strength of the pellet, and Figure 4 is the relationship between the addition rate of lubricant and the change in compressive strength of the pellet over time. FIG. 5 is a diagram showing the relationship between the reinforcing agent addition rate and the compressive strength of the pellet. FIG. 6 is a system diagram showing the outline of the apparatus for carrying out Example 1 of the present invention. The figure is a diagram showing the changes over time in the unconfined compressive strength and water content of the pellets prepared in Example 1, Figure 8 is a system diagram showing the outline of the apparatus for carrying out Example 2 of the present invention, and Figure 9 is the diagram of the present invention. FIG. 4 is a system diagram schematically showing an apparatus for implementing Example 4 of the invention. 1... Used ion exchange resin slurry, 2... Supply tank, 3... Dryer, 4... Powder hopper, 5...
... Kneading tank, 6... Additive tank, 7... Liquid silicon, 8... Additive tank, 9... Cellulose fiber and binder, 10... Additive water tank, 11...
Water, 12...Load cell, 13...Extrusion type granulation stone, 14...Cutter 1.15...Container, 16...
・Priketing machine, 1 diagram 20 3 mouths O124g g +012 14 +g
+3 207j
And -1 to ゛勺島 4 口0 15 30 As 6
0 Drunken Relief (C1) Neyu', 3Ei'J <-c Le O-zu Ndai 6 Seal) Shizoe Sword Rogo y-14I21 Cha Go Figure θ 3 Otsu q t2 1
5'
30 Pregnancy Mouth Lesson δ Mouth

Claims (1)

[Claims] 1. In a method of drying and pulverizing used ion exchange resin slurry generated in a nuclear power plant and then granulating it, after drying and pulverizing the used ion exchange resin slurry, water-soluble Binder 1-10% by weight, lubricant 0.5-5% by weight,
and a reinforcing agent in an amount of 5 to 20% by weight, followed by granulation. 2. In claim 1, when granulating by extrusion molding, the moisture content of the powder is 50% by weight or more6.
A method for processing radioactive used ion exchange resin, which comprises extrusion molding the resin after reducing it to 0% by weight or less. 3. In claim 1, when granulating by dry pressure molding (tablet machine), the moisture content of the powder is 15% by weight.
A method for processing radioactive used ion exchange resin, which is characterized by: 4. In claim 1, when granulating using a priketing machine, the moisture content of the powder is 40.
A method for processing radioactive used ion exchange resin, characterized by reducing the amount to less than % by weight. 5. In a method in which spent ion exchange resin slurry generated in a nuclear power plant is dried and powdered and then granulated, 100% by weight of the produced powder is added to the spent ion exchange resin slurry.
as water-soluble binder 1-10% by weight, lubricant 0.5-5%
% by weight, and then drying and powdering, and further adding 5 to 20% by weight of a reinforcing agent to this powder and granulating it. 6. In claim 5, the radioactive spent ion exchange product is characterized in that when dry pressure molding is performed using a tablet machine, the molding is performed after the moisture content of the powder is adjusted to 5 to 15% by weight. How to treat resin. 7. In claim 5, when the powder is granulated by dry pressure molding using a priquetting machine, the powder is molded after the moisture content of the powder is adjusted to 5 to 40% by weight. How to dispose of radioactive used ion exchange resin.