JPH10153694A - Method for processing radioactive solid waste containing metal aluminum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly retain the mechanical strength of a solid body and the leaching prevention performance of a radioactive nuclide by reacting a radioactive solid waste containing metal aluminum with an alkali solution for generating hydrogen gas and mixing the obtained reaction liquid with a solid material with a latent hydraulic property substance as a main constituent for hardening. SOLUTION: A radioactive solid waste containing metal aluminum and an alkali solution are reacted with each other for generating hydrogen gas, and the obtained reaction liquid and a hardening material with a latent hydraulic property substance as a main constituent are mixed for hardening. Alkali metal hydroxide, especially sodium hydroxide, is preferable as an alkali agent in an alkali solution. The alkali agent concentration in the alkali solution is normally 10-50wt.%. The alkali agent is preferably reacted at 5/10-12/1 by molar ratio for metal aluminum in the radioactive solid waste. A reaction temperature is preferably 50-120 deg.C. For example, a granulated blast furnace slag and a converter slag are used as the latent hydraulic property substance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating radioactive solid waste containing metallic aluminum using an inorganic solidifying material.

[0002]

BACKGROUND OF THE INVENTION In nuclear power plants, nuclear power related experimental facilities, nuclear fuel handling facilities, spent nuclear fuel reprocessing facilities, nuclear material powered ships and other radioactive material handling facilities,
A large amount of radioactive solid waste is generated. Among these, as a method of treating non-combustible radioactive solid waste, a method of solidifying the radioactive solid waste with cement, a method of compressing, or a method of heating and melting at a high temperature to solidify are known.

[0003] Such non-combustible radioactive solid wastes often contain metallic aluminum. For example, in a system for purifying air in a building such as a nuclear power plant, a particulate filter for exhaust gas, a so-called HEPA filter, is used, which comprises a glass fiber filter and an aluminum spacer.

However, when such a radioactive solid waste containing aluminum is heated and melted, the aluminum is oxidized to form an Al ₂ O ₃ film on the surface of the flake or bulk radioactive solid waste. It becomes a protective layer. Therefore, the flaky or massive radioactive solid waste remains in its original shape without being melted.

When radioactive solid waste containing aluminum is solidified with hydraulic cement typified by Portland cement, calcium hydroxide in the cement reacts with aluminum at the stage of mixing the two, and hydrogen gas bubbles are generated. Since the hardening of the cement begins before the generation of hydrogen gas is completed, a dense cement solid cannot be produced, and the mechanical strength of the cement solid and the ability to prevent radionuclides from leaching become insufficient.

As a method of solidifying such a radioactive waste containing metallic aluminum, for example, JP-A-61-32000 and JP-A-4-287000 disclose aluminum in advance with an alkali substance or hydrogen peroxide. A method has been proposed in which hydrogen gas is generated by reacting and then solidified with cement. However, in Portland cement and the like which have been conventionally used, when the alkali concentration is high, a quick setting reaction occurs during kneading, and even if the solidification treatment operation cannot be performed or is performed, a cement having good solidified physical properties (compressive strength, etc.). A solid cannot be obtained.

It has also been proposed to add lithium nitrate in order to suppress the corrosion of aluminum in the radioactive solid waste by reacting with the cement. However, it is unclear whether the suppression effect of the corrosion inhibitor can be continued even in the order of several hundred years.

In view of the above circumstances, the present inventors have conducted intensive studies on a method for treating radioactive solid waste containing aluminum, and found that after reacting aluminum with an alkali substance in advance to generate hydrogen gas, By adding and solidifying a solidifying material containing a latent hydraulic substance as a main component to the reaction solution, radioactive solid waste can be efficiently treated, and the obtained solidified product has excellent mechanical strength and The present inventors have found that they have the ability to prevent leaching of radionuclides, and have completed the present invention.

[0009]

An object of the present invention is to provide a method for solidifying a radioactive solid waste containing aluminum, which is capable of being highly filled and solidified, and which has an excellent mechanical strength and a performance of preventing radionuclides from leaching out. It is an object of the present invention to provide a method for treating radioactive solid waste.

[0010]

SUMMARY OF THE INVENTION A method for treating radioactive solid waste containing metallic aluminum according to the present invention is obtained after reacting a radioactive solid waste containing metallic aluminum with an alkali solution to generate hydrogen gas. The reaction liquid is mixed with a solidifying material mainly composed of a latent hydraulic substance and solidified.

The alkali agent in the alkali solution includes at least one selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates and alkali metal silicates. Further, the molar ratio between the metal aluminum and the alkali agent (alkali / aluminum) is preferably 5/10 or more.

The method for treating a radioactive solid waste containing aluminum metal according to the present invention is suitable when the radioactive waste containing aluminum metal is incinerated ash. Further, when the metal aluminum-containing radioactive solid waste is a particulate filter for purifying exhaust gas containing glass fibers, when reacting the metal aluminum contained in the filter with the alkali solution, the glass fibers contained in the filter are removed. Is also preferably dissolved.

In the case where the radioactive solid waste containing metallic aluminum is miscellaneous solid waste, after reacting metallic aluminum in the miscellaneous solid waste with an alkali solution, the insoluble miscellaneous solid is removed. It is preferable to add a solidifying material containing a latent hydraulic substance as a main component to the reaction liquid to solidify the same.

Further, when the metal aluminum-containing radioactive solid waste is miscellaneous solid waste, after reacting the metallic aluminum in the miscellaneous solid waste with an alkali agent, the insoluble miscellaneous solid is removed. It is preferable that the precipitate is separated from the reaction solution by solid-liquid separation, and a solidifying material containing a latent hydraulic substance as a main component is added to the obtained solid to solidify.

The solidified material as described above contains, if necessary, an ultrafine powder material together with a latent hydraulic material, and may further contain an inorganic needle-like material. As the latent hydraulic substance, at least one selected from the group consisting of granulated blast furnace slag, converter slag, and incinerated fly ash can be used.

Further, as the ultrafine powder substance, at least one selected from the group consisting of silica fume, silica powder, alumina powder and ultrafine anhydrous silica can be used. As inorganic needle-like substances, wollastonite,
At least one selected from the group consisting of sepiolite, asbestos, carbon fiber, and alumina fiber can be used.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for treating radioactive solid waste containing metallic aluminum according to the present invention will be described in detail.

The method for treating a radioactive solid waste containing metallic aluminum according to the present invention comprises reacting a radioactive solid waste containing metallic aluminum with an alkali solution to generate hydrogen gas, and then obtaining the obtained reaction gas. The liquid and a solidifying material mainly composed of a latent hydraulic substance are mixed and solidified. In this case, a solidified material may be added to the reaction liquid, or conversely, the reaction liquid may be added to the solidified material.

The radioactive solid waste containing metallic aluminum refers to non-combustible materials generated in radioactive facilities such as nuclear power plants, nuclear facilities, nuclear fuel handling facilities, spent nuclear fuel reprocessing facilities, and nuclear powered ships. Solid waste containing metallic aluminum, for example, incineration ash generated after incineration of combustible waste, particulate filter for exhaust gas purification containing glass fibers (HEPA filter), heat insulating material Miscellaneous solid wastes such as covers and electric drills.

As the alkaline agent in the alkaline solution,
Consists of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, alkali metal carbonates such as sodium carbonate and potassium carbonate, and alkali metal silicates such as sodium silicate At least one selected from the group is mentioned. Of these, alkali metal hydroxides are preferred, and sodium hydroxide is particularly preferred.

The alkali dissolving solution is usually prepared by dissolving the above alkali agent in water. The concentration of the alkali agent in the alkali dissolving solution depends on the rate of reaction between the alkali and aluminum due to the shape of the metal aluminum in the waste and the reaction heat. It is selected in an appropriate range from the viewpoint of controllability, but is usually 10 to 50% by weight.
It is.

The alkali agent is used in a molar ratio (alkali / aluminum) of 5/10 or more, preferably 5/10 to 12 with respect to metallic aluminum in the radioactive solid waste.
The reaction is desirably performed in the amount of / 1.

When the molar ratio (metal / aluminum) of the metal aluminum and the alkali agent is 1 or less, a precipitate (precipitation of aluminum hydroxide) may be formed in the reaction solution. In this case, the slurry (reaction liquid) containing the precipitate of aluminum hydroxide can be directly mixed with a solidifying material mainly composed of a latent hydraulic substance and solidified. Also, the precipitate of aluminum hydroxide is separated from this slurry,
The sediment (solid content) after the separation can be solidified with a solidifying material containing a latent hydraulic substance as a main component. Further, the reaction solution after solid-liquid separation can be reused as an alkali solution. When the reaction solution is reused as the alkali solution, the alkali removed together with the precipitation of aluminum hydroxide may be supplied.

The reaction between the metallic aluminum and the alkali solution depends on the composition of the radioactive waste and the intensity of stirring, but the reaction temperature is 25 ° C. or higher, preferably 50 to 120 ° C.
It is desirable that

In the present invention, a reaction solution obtained by reacting metallic aluminum and an alkali solution is mixed with a solidifying material (SC material) containing a latent hydraulic substance as a main component and solidified. As the latent hydraulic substance, specifically, granulated blast furnace slag, converter slag, incinerated fly ash, and the like can be used, and two or more of these can be used in combination. Of these, granulated blast furnace slag is preferred.

This granulated blast furnace slag has a Blaine specific surface area of at least 1000 cm ² / g, preferably from 2000 to 20 g / m 2.
000 cm ² / g, particularly preferably 5000 to 1000
It is preferably 0 cm ² / g.

It is also possible to use two or more types of granulated blast furnace slag having different specific surface areas of the blast furnace, for example, those having a specific surface area of 2,000 to 5,000 cm ² / g (S)
And (L) of 10,000 to 30,000 cm ² / g can be used in combination.
It can be used in such an amount that the (weight ratio) becomes 1 to 20, preferably 2 to 10.

[0028] The solidified material used in the present invention may contain an ultrafine powder substance as required. The ultrafine powder material has an average particle size smaller than the particle size of the latent hydraulic material, and the average particle size of the ultrafine powder material is preferably one order of magnitude larger than the particle size of the latent hydraulic material. Smaller than
More preferably, it is at least two orders of magnitude smaller. Specifically, the average particle size of the ultrafine powder material is usually 10 μm or less, preferably 0 μm or less.
_. It is a 01~2μm.

Examples of such an ultrafine powder substance include silica fume, silica powder, alumina powder and ultrafine anhydrous silica. Two or more of these can be used in combination. Of these, silica fume is preferred. The ultrafine powder substance is usually 2 to 100 parts by weight, preferably 5 to 3 parts by weight, based on 100 parts by weight of the latent hydraulic substance.
It can be used in an amount of 0 parts by weight.

The solidified material used in the present invention may contain an inorganic needle-like substance in addition to the above-mentioned ultrafine powder substance, if necessary. Examples of the inorganic needle-like substance include wollastonite, sepiolite, asbestos, carbon fiber, and alumina fiber. Two or more of these can be used in combination. Of these, wollastonite is preferred. The inorganic acicular substance is usually 1 to 50 parts by weight based on 100 parts by weight of the total amount of the latent hydraulic substance and the ultrafine powder substance.
It can be used in an amount of 2 parts by weight, preferably 2 to 20 parts by weight.

The solidified material used in the present invention may be, if necessary, ¹⁴ g of quicklime, slaked lime, portland cement or the like.
It may contain a C adsorbent. Such a ¹⁴ C adsorbent may be contained in the solidified material in an amount of usually about 2 to 40% by weight.

The solidified material mainly composed of the latent hydraulic substance as described above can be obtained by mixing the above-mentioned components in powder in a predetermined amount. In the present invention, this solidified material is used as the reaction solution 10
25 to 100 parts by weight, preferably 3 to 0 parts by weight
It is desirable to use it in an amount of 4 to 80 parts by weight.

In the present invention, the reaction liquid between the radioactive solid waste containing metallic aluminum and the alkali solution is solidified by using the solidifying material (SC material) mainly composed of the latent hydraulic substance as described above. At this time, an aqueous solution of an alkali metal hydroxide such as NaOH may be further added as an alkali stimulant to the reaction solution after the completion of hydrogen generation, if necessary. For example, an alkali stimulant having a concentration of about 10 to 50% by weight can be used in an amount of usually 3 to 30 parts by weight, preferably 10 to 20 parts by weight, based on 100 parts by weight of the solidifying material.

When the viscosity of the reaction solution or the mixed slurry of the reaction solution and the solidifying material is too high to be kneaded,
Dispersants can also be added. As this dispersant,
A polymer having a carboxylic acid group or a salt thereof in the molecule can be used. For example, poly (meth) acrylic acid, acrylic acid / maleic acid copolymer, acrylic acid / maleic acid / vinyl ether copolymer, acrylic acid itaconic acid-styrene copolymer, acrylic acid-itaconic acid-methacrylic acid-styrene copolymer, maleic acid-C ₅ ~ anhydrous
C ₈ olefin copolymers and their salts (eg, sodium salts) can be used. Examples of the C ₅ -C ₈ olefin include 2-methyl-1-butene, 1-pentene, 1-pentene,
Hexene, amylene, cyclopentene, cyclohexene and the like can be mentioned.

Further, formalin condensate of naphthalenesulfonic acid, ligninsulfonic acid condensate, and the like, which are generally used as a cement water reducing agent, can also be used.

Among these, preferred are sodium salts of acrylic acid / maleic acid copolymers, sodium salts of maleic anhydride / C ₅ -C ₈ olefin copolymers, and sodium salts of acrylic acid / itaconic acid / styrene copolymer. . The dispersant as described above is usually 0.1 to 15 parts by weight, preferably 0.5 to 6 parts by weight, based on 100 parts by weight of the total of the latent hydraulic substance and the optional ultrafine powder substance. It can be used in quantity. The dispersant is preferably used as an aqueous solution having a concentration of about 10 to 50% by weight.

The details of the solidifying material containing a latent hydraulic substance as a main component as described above are described in JP-A-8-179095 filed earlier by the present applicant. The technology described in the gazette can be used.

In the present invention, components such as the above-described solidifying material containing a latent hydraulic substance as a main component and, if necessary, a dispersant are added to an alkali solution in which metallic aluminum is dissolved, and the mixture is kneaded.・ I solidify it. The compressive strength of the obtained solidified body is 15 kgf / cm ² or more, preferably 80 kgf / cm ²
It is desirable that this is the case.

According to the treatment method of the present invention, metallic aluminum in metallic aluminum-containing radioactive solid waste reacts with an alkaline agent to generate hydrogen gas, and is converted into aluminum hydroxide or alkali aluminate. For this reason, even if the radioactive solid waste after the treatment is solidified, the solidified material does not react with metallic aluminum, so that the solidified material has a low level of voids and cracks, and the solidified material has excellent mechanical strength. And has the ability to prevent radionuclides leaching.

Even after the above treatment, even if the radioactive solid waste that does not dissolve in alkali is melted and solidified, the metal aluminum is already aluminum hydroxide or alkali aluminate. Absent. For this reason, the Al ₂ O ₃ coating does not hinder the melting treatment of the flakes or massive radioactive solid waste. Hereinafter, a specific example of the method for treating radioactive solid waste containing metal aluminum according to the present invention will be described.

Solidification treatment of incinerated ash The alkali solution and a predetermined amount of water are put into a kneader, and the incinerated ash is gradually added thereto. The metal aluminum in the incineration ash reacts with the alkali to generate hydrogen gas. A solidifying material containing a latent hydraulic substance as a main component is added to the reaction solution after the generation of hydrogen gas, and the mixture is kneaded. The mixture is discharged into a drum, cured at room temperature to about 60 ° C., and solidified.

The HEPA filter is solidified. The HEPA filter has a glass fiber filter attached in a zigzag manner, and an aluminum spacer is used in the gap. When the HEPA filter is solidified, the filter portion (glass fiber and metal aluminum) is cut into an appropriate size as necessary, and kneaded with an alkali solution. The aluminum spacer reacts with the alkali solution to generate hydrogen gas. This reaction solution is heated to 40 to 120 ° C, preferably 70 to 120 ° C, particularly preferably 90 to 100 ° C, and stirred for 10 to 50 hours, preferably 20 to 40 hours,
Dissolve the glass fibers. In the solution obtained in this way,
After supplying and kneading a solidifying material mainly composed of a latent hydraulic substance, the mixture is discharged into a drum, cured at room temperature to 60 ° C., and solidified.

Solidification treatment of miscellaneous solid waste Miscellaneous solid waste includes waste containing metal aluminum such as a heat insulating material cover and an electric drill. The portion of such waste composed of a substance other than aluminum metal is separated and then solidified by a method such as filling and solidification after dissolution of the aluminum metal.

When treating such miscellaneous solid waste containing metallic aluminum, for example, it is stored in a palanquin or the like, immersed in an alkaline solution, and allowed to react until the generation of hydrogen is completed. After removing the waste,
A solidifying agent containing a latent hydraulic substance as a main component is added to the obtained reaction solution, and the mixture is kneaded.
Cur at ℃ and solidify.

When the amount of metallic aluminum in the miscellaneous solid waste is large relative to the alkali (the molar ratio (aluminum / alkali) is 1 or more), aluminum hydroxide precipitates and precipitates. That is, the metal aluminum in the miscellaneous solid waste is reacted with the alkali solution, the reaction is continued until the generation of hydrogen is completed, the miscellaneous solid waste insoluble in alkali is removed, and the obtained reaction solution (slurry) is added. After separating the precipitated aluminum hydroxide precipitate (solid content), a solidifying material containing a latent hydraulic substance as a main component is added to the solid content and kneaded in the presence of water. It may be cured at ６０60 ° C. and solidified. In this case, since aluminum hydroxide as a solid content is separated, the filling efficiency in the drum can can be increased. When the reaction solution after the solid-liquid separation is returned to the alkali dissolution tank, the reaction solution can be reused as a solution for dissolving aluminum metal.

[0046]

In the treatment method according to the present invention, since the metallic aluminum in the radioactive solid waste containing metallic aluminum reacts with the alkali solution to form aluminum hydroxide or alkali aluminate, No voids or cracks occur in the solidified body. For this reason, the mechanical strength of the solidified body and the performance of preventing radionuclides from leaching can be kept high.

When the exhaust gas purifying filter containing glass fibers is treated by the treatment method of the present invention, the glass fibers of the filter can be dissolved and solidified together with the metallic aluminum. Furthermore, when the miscellaneous solid waste is treated by the treatment method according to the present invention, metallic aluminum in the complex solid waste having a complicated shape can be selectively treated.

[0048]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.
In the following examples, a 40% by weight aqueous solution of a sodium salt of an amylene-maleic anhydride copolymer was used as a dispersant. Evaluation method The physical properties of the slurry and the solid obtained by the treatment method according to the present invention were measured as follows.

Flow value The slurry after kneading was measured according to JIS R5201. Compressive strength The kneaded slurry was poured into a 4 cm × 4 cm, 16 cm high compressive strength mold and cured at 60 ° C. for 24 hours. The solidified product was subjected to a 0.2 mm loading speed using an Amsler universal testing machine.
Calculate by dividing the load at the time of compressing and breaking at / min by the sectional area.

Water resistance: The kneaded slurry was poured into a water resistance test mold having a diameter of 4.5 cm and a height of 4.4 cm, and the solidified product cured at 60 ° C. for 24 hours was subjected to a 10-fold removal of solids by volume. Immerse in ionic water, measure weight change and volume change after one week to three months,
Water resistance was judged based on whether the surface had no cracks or cracks and maintained its original shape. (In addition, the evaluation of the water resistance performance is shown by ○ when the original shape is maintained even after one week to three months.) Gas generation The solid is immersed in a 1N-sodium hydroxide solution, Gas evolution was determined.

[0051]

[Example 1] Solidification of incineration ash From the analysis results of incineration ash stored in the nuclear power plant,
63.2% by weight of kaolin, 10.0% by weight of talc, 18.6% by weight of ferric oxide, 3.5% by weight of gypsum dihydrate, 1.1 of iron powder
% By weight and 0.5% by weight of metallic aluminum were mixed to obtain a simulated incinerated ash.

As a solidified material (SC material) mainly containing a latent hydraulic substance, an SC material (1) having the following composition was used. SC material (1) Granulated blast furnace slag (Brain specific surface area: 8000 cm ² / g): 90 parts by weight Silica fume: 10 parts by weight

A mortar mixer manufactured by Marubishi Machine Co., Ltd. was charged with 264 g of a 25% by weight aqueous NaOH solution and 500 g of water as an alkali solution, and 1066 g of simulated incinerated ash was gradually supplied while stirring at 140 rpm. After about 5 minutes, generation of hydrogen was confirmed. After 30 minutes, little evolution of hydrogen was seen. One hour after the start of the supply of the simulated incinerated ash, 86 g of a dispersant, 635 g of SC material (1), and 25% by weight of NaOH
113 g of an aqueous solution and 100 g of water were added and kneaded for 5 minutes. Flow value of slurry after kneading, compressive strength of solidified body,
Water resistance and gas evolution were evaluated. Table 1 shows the results.

[0054]

Example 2 A treatment was performed in the same manner as in Example 1 except that 113 g of a 25% by weight NaOH aqueous solution was not added, and the evaluation was performed. Table 1 shows the results.

[0055]

Example 3 Solidification of HEPA Filter The wooden frame of the HEPA filter manufactured by Cambridge was disassembled,
The glass filter and the metal aluminum spacer were taken out from the wooden frame bonding portion, and the glass filter was cut into 1 to 3 cm.

15.2 g of a metal aluminum spacer was supplied to a mortar mixer manufactured by Marubishi Machine Co., Ltd. while stirring 100 g of a 25 wt% NaOH aqueous solution at 140 rpm. After the generation of hydrogen disappeared, the glass filter was impregnated with a solution of metallic aluminum and stirred at 90 ° C. for 24 hours to dissolve the glass filter, and 3.5 g of a dispersing agent was added to the SC material having the following composition. 75 g of (2) was added and kneaded for 5 minutes. The flow value of the slurry after kneading, the compressive strength of the solidified body, water resistance and gas generation were evaluated. Table 1 shows the results.

The filling ratio of metallic aluminum in the obtained solid was 7.5% by weight. One HEPA filter contains about 3 kg of metallic aluminum, which indicates that about 8 filters can be filled when converted to a 200-liter drum. SC material (2) Granulated blast furnace slag (Brain specific surface area 10,000 cm ² / g): 90 parts by weight Silica fume: 10 parts by weight Wollastonite: 10 parts by weight

[0058]

[Table 1]

[0059]

Embodiment 4 18 g of metallic aluminum and 25 wt% N
An aOH aqueous solution (1066 g) and water (332.5 g) were gradually mixed and reacted to prepare a simulated liquid in which metallic aluminum was dissolved. The SC material (1) was added to this simulated liquid for 800
g and 32 g of a dispersant, and kneaded with a mortar mixer for 5 minutes to evaluate the flow value, specific gravity, compressive strength, and water resistance. Table 2 shows the results.

[0060]

Example 5 180 g of metallic aluminum and 25% by weight
1066 g of an aqueous NaOH solution and 332.5 g of water were mixed and reacted to prepare a simulated liquid in which metallic aluminum was dissolved. An SC material (3) having the following composition was added to this simulated liquid.
Was added and 48 g of a dispersant was added, and the mixture was kneaded with a mortar mixer for 5 minutes, and the flow value, specific gravity, compressive strength, and water resistance were evaluated. Table 2 shows the results. SC material (3) Granulated blast furnace slag (Brain specific surface area: 4500 cm ² / g): 70 parts by weight Silica fume: 10 parts by weight Slaked lime: 20 parts by weight

[0061]

Example 6 138.9 g of metallic aluminum, 710 g of a 25 wt% NaOH aqueous solution, and 311.6 g of water were mixed and reacted to prepare a simulated liquid in which metallic aluminum was dissolved. 918 g of the SC material (1) was added to this simulation liquid,
36.7 g of the dispersant was added and kneaded with a mortar mixer for 5 minutes, and the flow value, specific gravity, compressive strength, and water resistance were evaluated. Table 2 shows the results.

[0062]

Example 7 120 g of metallic aluminum and 25% by weight
497.7 g of an aqueous NaOH solution and 418 g of water were mixed and reacted to prepare a simulated liquid in which metallic aluminum was dissolved. To this simulated liquid, 800 g of the SC material (2) and 32 g of a dispersant were added and kneaded with a mortar mixer for 5 minutes, and the flow value, specific gravity, compressive strength, and water resistance were evaluated. Table 2 shows the results.

[0063]

Embodiment 8 180 g of metallic aluminum and 25% by weight
533.3 g of an aqueous NaOH solution and 492 g of water were mixed and reacted to prepare a simulated liquid in which metallic aluminum was dissolved. 600 g of the SC material (3) and 22.2 g of the dispersant were added to the simulated liquid and kneaded with a mortar mixer for 5 minutes, and the flow value, specific gravity, compressive strength, and water resistance were evaluated.
Table 2 shows the results.

[0064]

Embodiment 9: 153 g of metallic aluminum and 25% by weight
1000 g of NaOH aqueous solution and 43 g of water were mixed and reacted to prepare a simulated solution in which metallic aluminum was dissolved. SC material (4) having the following composition was added to this simulated liquid for 7 minutes.
After adding 00 g and 35 g of a dispersant, the mixture was kneaded with a mortar mixer for 5 minutes, and the flow value, specific gravity, compressive strength, and water resistance were evaluated. Table 2 shows the results. SC material (4) Granulated blast furnace slag (Brain specific surface area: 4000 cm ² / g value): 90 parts by weight Slaked lime: 10 parts by weight

[0065]

Comparative Example 1 180 g of metallic aluminum and 25% by weight
A simulation liquid in which metallic aluminum was dissolved was prepared by mixing and reacting 1066 g of an aqueous NaOH solution and 32.5 g of water. Portland cement 1200
g and 48 g of a dispersing agent were added and kneaded with a mortar mixer, but cement was partially set and a good solidified product was not obtained.

[0066]

[Table 2]

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kazunori Suzuki 2205 Narita-cho, Oarai-cho, Higashiibaraki-gun, Ibaraki Prefecture Inside the Niigata Oarai Nuclear Technology Development Center (72) Inventor Yoshimitsu Karasawa Hongo, Fujioka City, Gunma Prefecture 903-61 (72) Inventor Masayuki Kiyomoto 1476-5 Sachigawa, Omiya City, Saitama Prefecture

Claims (12)

[Claims] 1. A radioactive solid waste containing metallic aluminum is reacted with an alkali solution to generate hydrogen gas, and then the obtained reaction solution is solidified with a latent hydraulic substance as a main component. A method for treating metallic aluminum-containing radioactive solid waste, comprising mixing and solidifying the mixture. 2. The method according to claim 1, wherein the alkali agent in the alkali solution is at least one selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates and alkali metal silicates. The method for treating radioactive solid waste containing metallic aluminum according to claim 1. 3. The method for treating radioactive solid waste containing metallic aluminum according to claim 1, wherein the molar ratio between the metallic aluminum and the alkali agent (alkali / aluminum) is 5/10 or more. 4. The method according to claim 1, wherein said radioactive solid waste containing metallic aluminum is incinerated ash. 5. The radioactive solid waste containing metallic aluminum is a particulate filter for purifying exhaust gas containing glass fibers, and is contained in the filter when reacting metallic aluminum contained in the filter with an alkali solution. The method for treating metallic aluminum-containing radioactive solid waste according to claim 1, wherein the glass fiber to be dissolved is also dissolved. 6. The radioactive solid waste containing metallic aluminum is miscellaneous solid waste. After reacting metallic aluminum in the miscellaneous solid waste with an alkali solution, the insoluble miscellaneous solid is removed. The method for treating a radioactive solid waste containing metallic aluminum according to claim 1, wherein a solidifying material containing a latent hydraulic substance as a main component is added to the obtained reaction solution to be solidified. 7. After reacting the metallic aluminum in the miscellaneous solid waste with the alkali solution, the insoluble miscellaneous solid is removed, and the precipitate is solid-liquid separated from the obtained reaction solution. 7. The method for treating a radioactive solid waste containing metallic aluminum according to claim 6, wherein a solidifying material containing a latent hydraulic substance as a main component is added to the solid content to be solidified. 8. The solidified material contains an ultrafine powder material together with a latent hydraulic material.
3. The method for treating a radioactive solid waste containing metal aluminum according to item 1. 9. The method for treating radioactive solid waste containing aluminum metal according to claim 8, wherein the solidified material contains an inorganic needle-like substance in addition to the latent hydraulic substance and the ultrafine powder substance. . 10. The metallic aluminum-containing radioactive solid according to claim 1, wherein the latent hydraulic substance is at least one selected from the group consisting of granulated blast furnace slag, converter slag, and incinerated fly ash. Waste treatment method. 11. The metal according to claim 8, wherein the ultrafine powder material is at least one selected from the group consisting of silica fume, silica stone powder, alumina powder and ultrafine anhydrous silica. A method for treating radioactive solid waste containing aluminum. 12. The radioactive material containing metal aluminum according to claim 9, wherein the inorganic acicular substance is at least one selected from the group consisting of wollastonite, sepiolite, asbestos, carbon fiber, and alumina fiber. Solid waste treatment method.