JP2018072082A - Method for processing radioactive contaminated water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method for solidifying radioactive contaminated water in a short time.SOLUTION: A water-containing resin composition, which contains radioactive contaminated water (A), one or more thiol compounds (B) selected from a secondary thiol compound (B1) and a tertiary thiol compound (B2), a radical polymerizable compound (C), a filler (D) and a surfactant (E), is solidified by addition of a radical polymerizable initiator (F). A solidifying material is sealed in a container and buried in the ground.SELECTED DRAWING: None

Description

  The present invention relates to a method for treating radioactively contaminated water generated by an accident at a nuclear power plant or the like. Specifically, the present invention relates to a method for solidifying radioactively contaminated water, and further relates to a method for treating a solidified body obtained by the solidifying method of the present invention by enclosing it in a container.

Due to the accident at the nuclear power plant, a large amount of radioactively contaminated water is generated, and various studies are being conducted to treat it until it reaches a safe level. Non-Patent Document 1 reports the implementation status of contaminated water purification by multi-nuclide removal equipment. The treatment methods of tritium water generated here are formation injection, ocean discharge, water vapor release, hydrogen release, underground burial. There is a discussion about how.
As a method of treating contaminated water as a solidified body, Patent Document 1 discloses a method of reacting treated water containing tritium with hemihydrate gypsum and taking the treated water into crystal water of dihydrate gypsum. Furthermore, Patent Document 2 discloses a method for treating contaminated water by mixing paper sludge incineration ash, an alkali activator, and contaminated water to form a solid polymer.

Japanese Patent Laying-Open No. 2015-062004 JP2015-231610A

Ministry of Economy, Trade and Industry homepage "Countermeasures against contaminated water at Fukushima Daiichi Nuclear Power Station" http://www.meti.go.jp/earthquake/nuclear/osensuitaisaku.html

However, for radioactively contaminated water, we are looking for effective treatment means from the viewpoint of treatment period, cost, safety and reputational measures, and in the meantime treated water (tritium water) generated through multi-nuclide removal equipment ) Will continue to increase, there is currently a temporary tank added to temporarily store this. Based on these current conditions, radioactive contaminated water has the following problems.
(1) Heavy metal elements such as strontium contained in radioactively contaminated water can be removed to some extent by means of ion exchange membranes, centrifuges, water distillation, electrolysis, etc., but are not completely removed.
(2) Tritium water contained in the treated water from which heavy metal elements have been removed is chemically equivalent to water molecules, so it cannot be completely separated from water even though it can be concentrated to some extent.
(3) Although the concentrated tritium water is stored in the temporary tank, the inner wall of the temporary tank deteriorates due to the radioactivity of the tritium water, and cannot be stably stored for a long period of time. Also, the inside of the deteriorated tank cannot be inspected, and there is a risk of damage due to the influence of an earthquake or the like. Due to these factors, when tritiated water concentrated to a high concentration flows out, there is a risk of exposure to workers performing operations such as stopping the spill, or secondary contamination such as penetration into the soil and further contamination. There are also concerns about disasters.
Therefore, it is one of effective means to keep radioactively contaminated water stably in a solidified state. However, the method of Patent Document 1 has a problem that it takes time to take the treated water into the crystal water of dihydrate gypsum and solidify it completely. The method of Patent Document 2 has a problem that the solidified geopolymer itself becomes a radioactive pollutant.

  Based on the above points, an object of the present invention is to provide a treatment method for solidifying radioactively contaminated water in a short time. Another object of the present invention is to provide a method for stably storing for a long period of time by enclosing a solidified body obtained by such a processing method in a container.

That is, the gist of the present invention is the following [1] to [11].
[1] A method for treating radioactively contaminated water comprising a step of solidifying a hydrous resin composition containing radioactively contaminated water (A), wherein the hydrous resin composition is a mixture containing radioactively contaminated water (A) A radical polymerization initiator (F) is added to the liquid (I), and the mixed liquid (I) is selected from radioactively contaminated water (A), a secondary thiol compound (B1), and a tertiary thiol compound (B2). Including one or more thiol compounds (B), radical polymerizable compounds (C), fillers (D), and surfactants (E), and the hydrated resin composition comprises 100 parts by mass of the component (C). Radiation containing 5 to 50 parts by mass of the component (A) and 0.05 to 10 parts by mass of the component (E) with respect to a total of 100 parts by mass of the components (A) to (F) How to treat contaminated water.
[2] The hydrated resin composition further includes at least one selected from Group 1 to Group 2 metal elements, Group 3 to 12 metal elements, Group 13 to 14 metal elements, rare earth metal elements, and bismuth. The method for treating radioactive contaminated water according to the above [1], comprising the metal compound (M) containing the metal M.
[3] Step 1 of obtaining a mixed solution (i) by mixing the radical polymerizable compound (C) and the thiol compound (B), the radioactively contaminated water (A) and the surfactant (E) Step 2 of mixing and mixing the liquid mixture (i) to obtain the liquid mixture (I), and step 3 of mixing the liquid mixture (I) and the radical polymerization initiator (F). The method for treating radioactive contaminated water according to the above [1] or [2].
[4] The thiol compound (B) is 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5-tris [2- (3- Mercaptobutyryloxyethyl)]-1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, trimethylolethanetris (3-mercaptobutyrate) and trimethylolpropane tris (3- The method for treating radioactive contaminated water according to any one of the above [1] to [3], which is one or more selected from mercaptobutyrate.
[5] The water-containing resin composition is 0.01 to 15 parts by mass of the thiol compound (B) and 10 to 500 parts by mass of the filler (D) with respect to 100 parts by mass of the radical polymerizable compound (C). The method for treating radioactive contaminated water according to any one of [1] to [4] above, which is contained in a part.
[6] The radioactively contaminated water (A) is composed of tritium water from which radioactive metals have been removed, Group 1 to 2 metal elements, Group 3 to 12 metal elements, Group 13 to 14 metal elements, and rare earth elements. The method for treating radioactive contaminated water according to any one of [1] to [5] above, wherein the metal compound (M) containing at least one metal M selected from metal elements and bismuth is blended. .
[7] The radioactively contaminated water (A) is tritium water from which radioactive metals have been removed, and the filler (D) is a metal element belonging to Groups 1 and 2, a metal element belonging to Groups 3 to 12, and 13 to 14 Any one of the above-mentioned [1] to [6], wherein a metal compound (M) containing at least one metal M selected from a group metal element, a rare earth metal element, and bismuth is blended. Radioactive contaminated water treatment method.
[8] In the storage container for radioactively contaminated water, the radioactively contaminated water (A) is solidified by the treatment method described in any one of [1] to [7] above, and then the opening of the storage container A method for treating radioactive contaminated water that is sealed and stored.
[9] The method for treating radioactive contaminated water according to [8] above, wherein the storage container is made of glass fiber reinforced plastic.
[10] When the storage container is made of glass fiber reinforced plastic, the storage container includes the thiol compound (B), the radical polymerizable compound (C), the radical polymerization initiator (F), and the metal. The method for treating radioactive contaminated water according to the above [9], which is made of any material selected from a resin composition containing a compound, an epoxy resin, and a phenol resin.
[11] The method for treating radioactive contaminated water according to any one of [8] to [10] above, wherein the storage container is buried in the ground.

  ADVANTAGE OF THE INVENTION According to this invention, the processing method which solidifies radioactive contamination water in a short time can be provided. Moreover, the solidified body obtained by the treatment method of the present invention can be stably stored for a long period of time by enclosing it in a container.

The method for treating radioactive contaminated water of the present invention includes a step of solidifying the hydrated resin composition containing the radioactive contaminated water (A).
[Hydrous resin composition]
The water-containing resin composition is obtained by adding the radical polymerization initiator (F) to the mixed liquid (I) containing the radioactively contaminated water (A).
The mixed liquid (I) includes radioactively contaminated water (A), one or more thiol compounds (B) selected from a secondary thiol compound (B1) and a tertiary thiol compound (B2), a radical polymerizable compound ( C), filler (D), and surfactant (E).
Accordingly, the water-containing resin composition includes radioactively contaminated water (A), thiol compound (B), radical polymerizable compound (C), filler (D), surfactant (E), and radical polymerization initiator ( F) is included.
In addition, the metal is contained in the water-containing resin composition in this invention. The metal may be a radionuclide that is inevitably contained in the radioactively contaminated water, or may be a metal M described later that is added as necessary. Although content of the metal in a water-containing resin composition is not specifically limited, Preferably it is 0.1-10 mass parts with respect to 100 mass parts of radically polymerizable compounds (C), More preferably, it is 0.5-5 mass parts. It is.
Hereinafter, each of these components will be described.

<Radioactive contamination water (A)>
Radioactive polluted water contains radionuclides, which are metals.
The main radionuclides in radioactive contaminated water, cobalt ⁽⁶⁰ Co, half-life 5.27 years), strontium ⁽⁹⁰ Sr, half-life 28.78 years), ruthenium ⁽¹⁰⁶ Ru), antimony ⁽¹²⁵ Sb ), Cesium ( ¹³⁷ Cs, half-life 30.1 years), iodine ( ¹²⁹ I), tritium ( ³ H or T, half-life 12.32 years), and the like. In the method for treating radioactive contaminated water of the present invention, a thiol compound (B) and a metal contained in the radioactive contaminated water form a complex by adding a thiol compound (B) described later to the radioactive contaminated water. To stabilize. Furthermore, when this metal acts as a catalyst, curing of the radically polymerizable compound (C) described later proceeds, and a solidified body of radioactively contaminated water can be produced. If the thiol compound (B) is not present, the metal in the radioactively contaminated water is deactivated by the influence of water and loses its catalytic ability, so that the curing of the radical polymerizable compound (C) does not proceed and a solidified body is produced. I can't.

The radioactively contaminated water can be used as it is without any pretreatment. In this case, it is presumed that the thiol compound (B) is coordinated to a metal contained in the contaminated water to form a complex in accordance with the following priority order. The order of priority for forming the complex is estimated to be ¹⁰⁶ Ru> ⁶⁰ Co> ¹³⁷ Cs> ⁹⁰ Sr> ¹²⁵ Sb.
In addition, treated water (hereinafter also referred to as “tritium water”) obtained by removing main radionuclides from the radioactively contaminated water (A) in advance by the multi-nuclide removal equipment is treated by the method of the present invention to produce a solidified body. Also good. In this case, a metal M that functions as a curing catalyst may be added as necessary. Metal M is a metal element of Group 1 or 2 such as lithium, magnesium, calcium, and barium, titanium, zirconium, vanadium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, copper, silver, gold Group 3-12 metal elements such as zinc, Group 13-14 metal elements such as aluminum, indium, tin and lead, rare earth metal elements such as neodymium and cerium, and bismuth. One of these may be used alone, or two or more may be used. The aspect in which the metal M is added is not particularly limited, and may be added to tritium water, may be added to the radioactively contaminated water (A) from which the radionuclide has not been removed, and the filler (D) described later. You may add to.
When the metal M is added, it is preferably added as a metal compound (M) containing the metal M. The metal compound (M) is one or more selected from metal soaps and metal complexes having a β-diketone skeleton. The metal compound (M) is preferred. The metal soap in the present invention refers to a salt of a long chain fatty acid or an organic acid other than the long chain fatty acid and a metal element other than potassium and sodium. The metal complex having a β-diketone skeleton in the present invention refers to a complex in which a compound having a structure having one carbon atom between two carbonyl groups is coordinated with a metal element. Specifically, metal soaps such as manganese octylate, cobalt octylate, zinc octylate, vanadium octylate, cobalt naphthenate, copper naphthenate, barium naphthenate, vanadium acetoacetate, cobalt acetoacetate, and iron acetoacetate; Preferred examples include metal complexes having a β-diketone skeleton such as vanadium acetylacetonate, cobalt acetylacetonate, titanium acetylacetonate, titanium dibutoxybis (acetylacetonate), iron acetylacetonate, and acetoacetic acid ethyl ester cobalt. .

The radioactively contaminated water (A) contains a large amount of heavy metal elements and rare metal elements that are undergoing radiation decay unless pretreatment is performed. The heavy metal element and the rare metal element may be recovered from the contaminated water by trapping the thiol compound (B) after forming a complex with the heavy metal element and the rare metal element in the contaminated water. In this case, it is necessary to operate in an environment where radioactivity does not leak.
The amount of radioactively contaminated water (A) in the hydrated resin composition is 5 to 50 parts by mass, preferably 7 to 40 parts by mass, more preferably 100 parts by mass of the radical polymerizable compound (C) described later. 10 to 30 parts by mass.
Further, the content of the metal contained in the radioactively contaminated water (A) is preferably at least 100 ppm by mass or more, and when the content is not sufficient, as a curing catalyst for the radical polymerizable compound (C). From the viewpoint of supplementing the function, it is preferable to add the metal compound (M) as described above.

<Thiol compound (B)>
In the present invention, the thiol compound (B) has a function as a curing accelerator and is coordinated in the vicinity of the metal contained in the radioactively contaminated water (A) or the filler (D) to be described later. It is presumed that it has a function of preventing the deactivation of the metal and helping the metal to function as a curing catalyst.

In the present invention, the thiol compound (B) is one or more thiol compounds selected from the secondary thiol compound (B1) and the tertiary thiol compound (B2). The secondary thiol compound (B1) means a compound having at least one mercapto group bonded to a secondary carbon atom in the molecule, and the tertiary thiol compound (B2) is bonded to a tertiary carbon atom in the molecule. Means a compound having at least one mercapto group. The thiol compound (B) used in the present invention may be referred to as a mercapto group bonded to a secondary or tertiary carbon atom in the molecule (hereinafter referred to as “secondary mercapto group” or “tertiary mercapto group”, respectively). ) Is not particularly limited as long as it is a compound having at least one, but from the viewpoint of quickly curing even in a state containing water, and from the deactivation of the metal contained in the radioactively contaminated water and filler by water From the viewpoint of prevention, a polyfunctional thiol which is a compound having 2 or more secondary or tertiary mercapto groups in total in the molecule is preferable, and among them, 2 is a compound having 2 secondary or tertiary mercapto groups in the molecule. Functional thiols are preferred. Further, the secondary thiol compound (B1) is more preferable than the tertiary thiol compound (B2).
As used herein, “polyfunctional thiol” means a thiol compound having two or more mercapto groups as functional groups, and “bifunctional thiol” means two mercapto groups as functional groups. Means a thiol compound.

Specific examples of the thiol compound (B) used in the present invention include compounds described in JP2013-221091A. Among them, a thiol compound having a group including an ester structure represented by the following formula (T) is preferable, and in particular, when R ¹ is a secondary thiol compound (B1) in which a hydrogen atom is present, carbonyl oxygen and a mercapto group are Coordination to the metal M contained in the radioactively contaminated water (A) is facilitated, and the metal element is considered to be surrounded by the thiol compound. As a result, the contact between the metal element and water is suppressed. Seems to be able to. In the case of the tertiary thiol compound (B2), R ¹ and R ² are both bulkier substituents than hydrogen, and from the viewpoint of steric hindrance in the coordination of the mercapto group to the metal element, the secondary thiol compound (B1) It is considered that can better exhibit curing acceleration performance. However, even in the tertiary thiol compound (B2), when the carbonyl oxygen and the mercapto group are stably coordinated to the metal element, the contact between the metal element and water is further suppressed than in the secondary thiol compound (B1). It is thought to get.

(In the formula (T), R ¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aromatic group having 6 to 18 carbon atoms, and R ² is an alkyl group having 1 to 10 carbon atoms, Or an aromatic group having 6 to 18 carbon atoms, and M is a metal contained in the radioactively contaminated water (A).)
Preferred compounds used as the thiol compound (B) are 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5-tris [2- (3-Mercaptobutyryloxyethyl)]-1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, trimethylolethanetris (3-mercaptobutyrate) and trimethylolpropane tris (3-mercaptobutyrate), which may be used alone or in admixture of two or more.
The thiol compound (B) is preferably 0.01 to 15 parts by mass, more preferably 0.1 to 12 parts by mass, and still more preferably 0.3 to 100 parts by mass of the radical polymerizable compound (C) described later. -10 parts by mass, more preferably 0.5-10 parts by mass. When the amount of the thiol compound (B) is 0.01 parts by mass or more, a sufficient curing function can be obtained, and when it is 15 parts by mass or less, the reaction rate can be controlled while appropriately controlling.

<Radically polymerizable compound (C)>
As a solidifying agent for solidifying the radioactively contaminated water (A), a radical polymerizable compound (C) (hereinafter also referred to as “component (C)”) is used. In the present invention, the radical polymerizable compound refers to a compound having an ethylenically unsaturated group in the molecule and capable of proceeding a polymerization reaction by a radical.
Examples of radical polymerizable compounds include vinyl ester resins (epoxy (meth) acrylate resins), unsaturated polyester resins, polyester (meth) acrylate resins, urethane (meth) acrylate resins, (meth) acrylate resins, radical polymerizable unsaturated monomers. And a mixture of the above resin and a radically polymerizable unsaturated monomer, among others, a vinyl ester resin, an unsaturated polyester resin, or a mixture of these and a radically polymerizable unsaturated monomer. More than species are preferred. In the present specification, “(meth) acrylate” means “one or both of acrylate and methacrylate”.

[Vinyl ester resin]
As the vinyl ester resin, one obtained by reacting an unsaturated monobasic acid with an epoxy resin can be used.
Examples of the epoxy resin include bisphenol A diglycidyl ether and high molecular weight homologues thereof, novolak glycidyl ethers, and the like.
Specifically, bisphenol-type epoxy resins (for example, those obtained by reacting bisphenols such as bisphenol A, bisphenol F, bisphenol S and tetrabromobisphenol A with epichlorohydrin and / or methyl epichlorohydrin, or glycidyl of bisphenol A, And the like obtained by reacting a condensate of ether and the above bisphenol with epichlorohydrin and / or methyl epichlorohydrin), biphenyl type epoxy resin (for example, obtained by reacting biphenol with epichlorohydrin and / or methyl epichlorohydrin) , Naphthalene type epoxy resins (for example, those obtained by reacting dihydroxynaphthalene with epichlorohydrin and / or methyl epichlorohydrin), Aralkyl diphenol type epoxy resin (for example, obtained by reacting aralkyl phenol with epichlorohydrin and / or methyl epichlorohydrin), diglycidyl type epoxy resin (for example, dimer acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester) Alicyclic epoxy resins (for example, alicyclic diepoxy acetals, alicyclic diepoxy adipates, alicyclic diepoxycarboxylates, etc.), having an oxazolidone ring obtained by reacting the epoxy resin with diisocyanate Epoxy resins (as specific examples, Araldite AER4152 made by Asahi Kasei Epoxy), novolak type epoxy resins (for example, phenol novolak or cresol novolak and epichlorohydrin) And / or methyl epichlorohydrin), trisphenolmethane type epoxy resins (for example, those obtained by reacting trisphenolmethane, triscresol methane with epichlorohydrin and / or methyl epichlorohydrin). Can be mentioned.

Known unsaturated monobasic acids can be used, and examples thereof include (meth) acrylic acid, crotonic acid, cinnamic acid and the like. In addition, a reaction product of a compound having one hydroxy group and one or more (meth) acryloyl groups and a polybasic acid anhydride may be used. In the present specification, “(meth) acrylic acid” means “one or both of acrylic acid and methacrylic acid”, and “(meth) acryloyl group” means “acryloyl group and methacryloyl group”. Means one or both.
The said polybasic acid is used in order to increase the molecular weight of the said epoxy resin, and can use a well-known thing. For example, succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, fumaric acid, maleic acid, itaconic acid, tetrahydrophthalic acid, hexahydrophthalic acid, dimer acid, ethylene glycol 2 mol maleic anhydride adduct, polyethylene Glycol 2 mol maleic anhydride adduct, propylene glycol 2 mol maleic anhydride adduct, polypropylene glycol 2 mol maleic anhydride adduct, dodecanedioic acid, tridecanedioic acid, octadecanedioic acid, 1,16- (6 -Ethylhexadecane) dicarboxylic acid, 1,12- (6-ethyldodecane) dicarboxylic acid, carboxyl group-terminated butadiene / acrylonitrile copolymer (trade name Hycar CTBN), and the like.

[Unsaturated polyester resin]
As unsaturated polyester resin, what was obtained by esterifying the unsaturated dibasic acid and the dibasic acid component containing a saturated dibasic acid as needed, and a polyhydric alcohol component can be used. .
Examples of the unsaturated dibasic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride and the like, and these may be used alone or in combination of two or more.
Examples of the saturated dibasic acid include aliphatic dibasic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and isosebacic acid, phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid, and terephthalic acid. , Tetrachlorophthalic acid, tetrachlorophthalic anhydride, dimer acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid anhydride, 4 , 4′-biphenyldicarboxylic acid, aromatic dibasic acids such as dialkyl esters, halogenated saturated dibasic acids, and the like. These may be used alone or in combination of two or more.

The polyhydric alcohol is not particularly limited. For example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 2,2-dimethyl-1,3-propanedio -2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol, Polyethylene glycol, dipropylene glycol, polypropylene glycol, 1,2- Chrohexane glycol, 1,3-cyclohexane glycol, 1,4-cyclohexane glycol, 1,4-cyclohexanedimethanol, paraxylene glycol, bicyclohexyl-4,4'-diol, 2,6-decalin glycol, 2,7 A dihydric alcohol such as decalin glycol;
Two adducts, such as hydrogenated bisphenol A, cyclohexanedimethanol, bisphenol A, bisphenol F, bisphenol S, tetrabromobisphenol A and the like, and adducts of propylene oxide and alkylene oxide typified by ethylene oxide, etc. Examples thereof include trihydric or higher alcohols such as 1,2,3,4-tetrahydroxybutane, glycerin, trimethylolpropane and pentaerythritol.

The unsaturated polyester may be modified with a dicyclopentadiene compound within a range not impairing the effects of the present invention. Regarding modification methods using dicyclopentadiene compounds, for example, after obtaining dicyclopentadiene and a maleic acid addition product (sidedecanol monomaleate), this is used as a monobasic acid to introduce a dicyclopentadiene skeleton. The publicly known methods such as the method to do.
An oxidation polymerization (air curing) group such as an allyl group or a benzyl group can be introduced into the vinyl ester resin or unsaturated polyester resin used in the present invention. The introduction method is not particularly limited. For example, addition of an oxidation polymerization group-containing polymer, condensation of a compound having a hydroxyl group and an allyl ether group, allyl glycidyl ether, 2,6-diglycidyl phenyl allyl ether with a hydroxyl group and allyl ether And a method of adding a reaction product of a compound having a group and an acid anhydride.
Incidentally, the oxidative polymerization (air curing) in the present invention refers to cross-linking associated with the generation and decomposition of a peroxide by oxidation of a methylene bond between an ether bond and a double bond, such as found in an allyl ether group. .

[Polyester (meth) acrylate resin, urethane (meth) acrylate resin, and (meth) acrylate resin]
As the polyester (meth) acrylate resin in the present invention, for example, a polyester obtained by reacting a polyvalent carboxylic acid and a polyhydric alcohol, specifically, with respect to hydroxyl groups at both ends such as polyethylene terephthalate, ) A resin obtained by reacting acrylic acid can be used.
Moreover, as urethane (meth) acrylate resin, for example, it was obtained by making (meth) acrylic acid react with the hydroxyl group or isocyanato group of the both ends of the polyurethane obtained by making isocyanate and a polyhydric alcohol react. Resin can be used.
Examples of the (meth) acrylate resin include a poly (meth) acrylic resin having one or more substituents selected from a hydroxyl group, an isocyanato group, a carboxy group, and an epoxy group, ) A resin obtained by reacting a (meth) acrylic acid ester having a hydroxyl group with a substituent of a polymer with acrylate can be used.

[Radically polymerizable unsaturated monomer]
In the present invention, a radical polymerizable unsaturated monomer can be used as the radical polymerizable compound (C).
Although the radical polymerizable unsaturated monomer may be used alone, it is used as a mixture of the radical polymerizable unsaturated monomer and at least one of the vinyl ester resin and the unsaturated polyester resin. It is preferable.
Although there is no restriction | limiting in particular in the said radically polymerizable unsaturated monomer, What has a vinyl group or a (meth) acryloyl group is preferable.
Specific examples of the monomer having a vinyl group include styrene, p-chlorostyrene, vinyltoluene, α-methylstyrene, dichlorostyrene, divinylbenzene, t-butylstyrene, vinyl acetate, diallyl phthalate, triallyl isocyanurate. Etc.

  Specific examples of the monomer having a (meth) acryloyl group include acrylic acid esters and methacrylic acid esters. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, (meth) acrylic 2-ethylhexyl acid, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, Ethylene glycol monomethyl ether (meth) acrylate, ethylene glycol monoethyl ether (meth) acrylate, ethylene glycol monobutyl ether (meth) acrylate, ethylene glycol monohexyl ether (meth) acrylate, ethylene glycol mono 2-ethylhexyl Ether (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, diethylene glycol monobutyl ether (meth) acrylate, diethylene glycol monohexyl ether (meth) acrylate, diethylene glycol mono-2-ethylhexyl ether (meth) acrylate , Neopentyl glycol di (meth) acrylate, PTMG dimethacrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2-hydroxy 1,3 dimethacryloxypropane, 2,2-bis [4- (methacryloylethoxy) phenyl] Lopan, 2,2-bis [4- (methacryloxy / diethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy / polyethoxy) phenyl] propane, tetraethylene glycol diacrylate, bisphenol AEO modified (n = 2) Diacrylate, isocyanuric acid EO-modified (n = 3) diacrylate, pentaerythritol di (meth) acrylate monostearate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tricyclodecanyl (meta ) Acrylate, tricyclodecanyl methacrylate or tris (2-hydroxyethyl) isocyanurate.

Furthermore, as the polyfunctional (meth) acrylic acid ester, for example, ethylene glycol di (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1, Alkanediol di (meth) acrylates such as 4-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate; diethylene glycol di (meth) acrylate, dipropylene glycol Polyoxyalkylene-glycol di (meth) acrylates such as di (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate Trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Examples include pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate.
Furthermore, the following compounds can also be used as the radical polymerizable unsaturated monomer. Specifically, divinylbenzene, diallyl phthalate, triallyl phthalate, triallyl cyanurate, triallyl isocyanurate, allyl (meth) acrylate, diallyl fumarate, allyl methacrylate, vinyl benzyl butyl ether, vinyl benzyl hexyl ether, vinyl benzyl octyl Ether, vinylbenzyl (2-ethylhexyl) ether, vinylbenzyl (β-methoxymethyl) ether, vinylbenzyl (n-butoxypropyl) ether, vinylbenzylcyclohexyl ether, vinylbenzyl (β-phenoxyethyl) ether, vinylbenzyl dicyclo Pentenyl ether, vinylbenzyl dicyclopentenyloxyethyl ether, vinylbenzyl dicyclopentenyl methyl ether, divinyl vinyl Nyl ether can be mentioned.
These may be used alone or in combination of two or more.

Radical polymerizable unsaturated monomers can be used to improve the hardness, strength, etc. when solidifying radioactively contaminated water, but if its content is too high, it will lead to deterioration of the solidified body and environmental pollution There is a case. Therefore, the content of the radical polymerizable unsaturated monomer is preferably 90% by mass or less in the radical polymerizable compound (C).
Further, when the radically polymerizable compound (C) particularly contains styrene as the radically polymerizable unsaturated monomer, the content thereof is preferably 60% by mass or less, more preferably 50% by mass or less, and 20% by mass or less. Is more preferable, and 5 mass% or less is still more preferable.

The radical polymerizable compound (C) is a catalyst or polymerization inhibitor used when synthesizing vinyl ester resin, unsaturated polyester resin, polyester (meth) acrylate resin, urethane (meth) acrylate resin, and (meth) acrylate resin. May remain.
Examples of the catalyst include compounds containing tertiary nitrogen such as triethylamine, pyridine derivatives, imidazole derivatives and imidazole derivatives; amine salts such as tetramethylammonium chloride and triethylamine; and phosphorus compounds such as trimethylphosphine and triphenylphosphine. Can be mentioned.
Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, phenothiazine and the like.
When a catalyst or a polymerization inhibitor remains in the radical polymerizable compound (C), the amount thereof is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass in total of the vinyl ester resin and the unsaturated polyester resin, respectively. It is.
The content of the radically polymerizable compound (C) in the water-containing resin composition is preferably 15 to 95% by mass, more preferably 20 to 90% by mass. When the content of the radical polymerizable compound (C) is within the above range, the hardness of the solidified product is further improved.

<Filler (D)>
Contains a filler (D) (hereinafter also referred to as “component (D)”) in the water-containing resin composition for the purpose of improving workability and adjusting the physical properties of the solidified material when radioactively contaminated water is solidified. To do. Examples of the filler (D) include inorganic fillers and organic fillers.
Examples of inorganic fillers include cement, quicklime, river gravel, river sand, sea gravel, sea sand, mountain gravel, crushed stone, crushed sand, silica sand and other artificial aggregates such as ceramic and glass waste, talc. However, from the viewpoint of heat generation and shrinkage due to the hydration reaction of cement, a combination of cement having hydration reactivity and dry aggregate such as river gravel is preferable.
As cement, Portland cement such as ordinary Portland cement, early strong Portland cement, super early strong Portland cement, moderately hot Portland cement, sulfate-resistant Portland cement, mixed cements such as blast furnace cement, silica cement, fly ash cement, Special cements such as ultrafast cement, alumina cement, oil well cement, geothermal cement, color cement, fine powder cement, and various gypsums can be used.

In addition, aluminum hydroxide can be used from the viewpoint of imparting flame retardancy, and fumed silica, talc, and the like can also be used from the viewpoint of adjusting fluidity. Furthermore, a molecular sieve can also be used.
Furthermore, it is preferable to mix adsorbents such as zeolite and activated carbon from the viewpoint of removing pollutants and radioactive substances contained in water.
As the organic filler, organic fillers such as amide wax and water-absorbing polymer can also be used.
Further, a part or all of the filler (D) may be replaced with a solidified geopolymer disclosed in JP-A-2015-231610, or waste such as soil and rubble contaminated with radioactivity. In addition, when using tritium water from which metal species have been removed as the radioactively contaminated water (A), in order to supplement the amount of metal that functions as a curing catalyst, a metal compound (M) is added to the filler (D). You may mix. As the metal compound (M) in this case, those mentioned in the item of the radioactively contaminated water (A) can be used.

  As for content of a filler (D), 10-500 mass parts is preferable with respect to 100 mass parts of radically polymerizable compounds (C). When the amount of the filler (D) is within the above range, the viscosity during the treatment can be controlled to ensure sufficient workability, and sufficient strength is expressed when the radioactively contaminated water is solidified. be able to.

<Surfactant (E)>
A surfactant (E) (hereinafter also referred to as “component (E)”) is used for the purpose of improving the familiarity between the radical polymerizable compound (C) and the radioactively contaminated water (A). When radioactively contaminated water containing no surfactant is solidified, the radioactively contaminated water is ejected out of the cured product of the radical polymerizable compound (C), and only the radical polymerizable compound (C) tends to be cured. is there. By using the surfactant (E), the radical polymerizable compound (C) has an effect that it is cured while embracing the radioactively contaminated water and does not escape from the solidified body.

Examples of the surfactant include an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant. These surfactants may be used alone or in combination of two or more.
Among these surfactants, one or more selected from anionic surfactants and nonionic surfactants are preferable.
Examples of the anionic surfactant include alkyl sulfate esters such as sodium lauryl sulfate and triethanolamine lauryl sulfate, polyoxyethylene alkyl such as polyoxyethylene lauryl ether sodium sulfate and polyoxyethylene alkyl ether sulfate triethanolamine. Fatty acid salts such as ether sulfate ester salt, dodecylbenzenesulfonic acid, sodium dodecylbenzenesulfonate, sodium alkylnaphthalene sulfonate, sodium dialkylsulfosuccinate, sodium stearate soap, oleic acid potassium soap, castor oil potassium soap , Naphthalene sulfonic acid formalin condensate, special polymer system and the like.
Among these, sulfonates are preferable, sodium dialkylsulfosuccinate is more preferable, and sodium dioctylsulfosuccinate is still more preferable.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene distyrenated phenyl ether, Polyoxyethylene derivatives such as polyoxyethylene tribenzylphenyl ether and polyoxyethylene polyoxypropylene glycol; polyoxyalkylene alkyl ethers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate; polyoxy Ethylene sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Tate like polyoxyethylene sorbitan fatty acid esters; polyoxyethylene sorbit tetraoleate and the like of the polyoxyethylene sorbitol fatty acid esters; glycerol monostearate, glycerine fatty acid esters such as glycerol monooleate.
In these, polyoxyethylene alkyl ethers, such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, are preferable. Moreover, 5-15 are preferable and, as for HLB (Hydrophile-Lipophil Balance) of a nonionic surfactant, 6-12 are more preferable.

  The amount of the surfactant (E) in the water-containing resin composition is as follows: the radioactively contaminated water (A), the thiol compound (B), the radical polymerizable compound (C), the filler (D), and the surfactant. It is 0.05-10 mass parts with respect to a total of 100 mass parts of (E) and the radical polymerization initiator (F) mentioned later, Preferably it is 0.05-5 mass parts, More preferably, it is 0.05-3 mass. Part, more preferably 0.06 to 1 part by mass, still more preferably 0.07 to 0.5 part by mass. Since the fall of the water absorption of a filler (D) can be prevented as the quantity of surfactant is 0.05 mass part or more, the effect of a filler can be exhibited. Moreover, while being 10 mass parts or less, while being able to suppress the fall of a resin physical property, the balance of the performance obtained and cost improves.

<Radical polymerization initiator (F)>
In the water-containing resin composition in the treatment method of the present invention, a radical polymerization initiator (F) (hereinafter also referred to as “component (F)”) is used as a curing agent. Examples of the radical polymerization initiator (F) include at least one initiator selected from a thermal radical polymerization initiator and a photo radical polymerization initiator.
Examples of the thermal radical polymerization initiator include diacyl peroxides such as benzoyl peroxide, peroxyesters such as t-butylperoxybenzoate, hydroperoxides such as cumene hydroperoxide, and dialkyls such as dicumyl peroxide. Organic peroxides such as peroxides, ketone peroxides such as methyl ethyl ketone peroxide, acetylacetone peroxide, peroxyketals, alkyl peresters, and carbonates may be mentioned.
Examples of the photo radical polymerization initiator include benzoin ethers such as benzoin alkyl ether, benzophenones such as benzophenone, benzyl and methyl orthobenzoylbenzoate, benzyl dimethyl ketal, 2,2-diethoxyacetophenone, 2-hydroxy-2-methylprote Examples include acetophenones such as piophenone, 4-isopropyl-2-hydroxy-2-methylpropiophenone and 1,1-dichloroacetophenone, and thioxanthones such as 2-chlorothioxanthone, 2-methylthioxanthone and 2-isopropylthioxanthone. It is done.

The amount of the radical polymerization initiator (F) in the water-containing resin composition is preferably 0.3 to 10 parts by mass, more preferably 0.3 to 7 parts per 100 parts by mass of the radical polymerizable compound (C). It is a mass part, More preferably, it is 0.4-6 mass part, More preferably, it is 0.5-5 mass part.
When the amount of the radical polymerization initiator (F) is 0.3 parts by mass or more, the radically polymerizable water-containing resin composition of the present invention can be sufficiently cured, and when it is 10 parts by mass or less, the obtained effect And the balance of manufacturing costs.

<Other ingredients>
[Other curing accelerators]
The water-containing resin composition in the treatment method of the present invention may contain other curing accelerators other than the metal and thiol compound (B) contained in the radioactively contaminated water (A) for the purpose of improving curability. .
Other curing accelerators include amines such as aniline, N, N-substituted aniline, N, N-substituted-p-toluidine, and 4- (N, N-substituted amino) benzaldehyde. Aniline, N, N-dimethylaniline, N, N-diethylaniline, p-toluidine, N, N-dimethyl-p-toluidine, N, N-bis (2-hydroxyethyl) -p-toluidine, 4- (N , N-dimethylamino) benzaldehyde, 4- [N, N-bis (2-hydroxyethyl) amino] benzaldehyde, 4- (N-methyl-N-hydroxyethylamino) benzaldehyde, N, N-bis (2-hydroxy) Propyl) -p-toluidine, N-ethyl-m-toluidine, triethanolamine, m-toluidine, diethylenetriamine, pyridine, Enirimoruhorin, piperidine, N, N-bis (hydroxyethyl) aniline, the diethanol aniline can be used.

(Polymerization inhibitor)
In the water-containing resin composition in the treatment method of the present invention, a polymerization inhibitor may be used from the viewpoint of suppressing excessive polymerization and controlling the reaction rate.
Examples of the polymerization inhibitor include known ones such as hydroquinone, methylhydroquinone, phenothiazine, catechol, and 4-tert-butylcatechol.
When a polymerization inhibitor is contained, the amount thereof is preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the radical polymerizable compound (C).

(Curing retarder)
The water-containing resin composition in the treatment method of the present invention may contain a curing retarder for the purpose of delaying the curing of the radical polymerizable compound (C). Examples of the curing retarder include free radical curing retarders such as 2,2,6,6-tetramethylpiperidine 1-oxyl free radical (TEMPO), 4-hydroxy-2,2,6,6- TEMPO such as tetramethylpiperidine 1-oxyl free radical (4H-TEMPO), 4-oxo-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (4-Oxo-TEMPO) and derivatives thereof . Among these, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (4H-TEMPO) is preferable in terms of cost and ease of handling.
In the case of containing an inorganic filler such as cement, a setting retarder selected from oxycarboxylic acid, phosphonic acid and derivatives thereof can also be used. Specifically, examples of the oxycarboxylic acid and derivatives thereof include gluconic acid, glucoheptonic acid, arabonic acid, malic acid, tartaric acid, citric acid, and alkali metal salts and alkaline earth metal salts thereof. Examples of phosphonic acid and its derivatives include aluminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), hexamethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta ( Methylenephosphonic acid), their alkali metal salts and alkaline earth metal salts.

  When the curing retarder is contained, the amount thereof is preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the radical polymerizable compound (C).

[Coupling agent]
In the treatment method of the present invention, it is preferable to solidify the water-containing resin composition in a storage container as described later. Therefore, a coupling agent may be used for the purpose of improving the adhesion of the water-containing resin composition to the storage container. Examples of coupling agents include silane coupling agents, titanate coupling agents, aluminum coupling agents, and the like.
An example of such a coupling agent is a silane coupling agent represented by R ³ —Si (OR ⁴ ) ₃ . Examples of R ³ include an aminopropyl group, a glycidyloxy group, a methacryloxy group, an N-phenylaminopropyl group, a mercapto group, and a vinyl group. Examples of R ⁴ include a methyl group and an ethyl group. Etc.
When a coupling agent is contained, the amount thereof is preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the radical polymerizable compound (C).

(Wet dispersant)
The water-containing resin composition in the treatment method of the present invention may contain a wetting and dispersing agent.
Examples of the wetting and dispersing agent include a fluorine-based wetting and dispersing agent and a silicon-based wetting and dispersing agent, and these may be used alone or in combination of two or more.
Commercially available fluorine-based wetting and dispersing agents include MegaFac (registered trademark) F176, MegaFac (registered trademark) R08 (manufactured by Dainippon Ink and Chemicals, Inc.), PF656, PF6320 (manufactured by OMNOVA), Troisol S- 366 (manufactured by Troy Chemical Co., Ltd.), Florard FC430 (manufactured by 3M Japan Co., Ltd.), polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.
Commercially available products of the silicone-based wetting and dispersing agent include BYK (registered trademark) -322, BYK (registered trademark) -377, BYK (registered trademark) -UV3570, BYK (registered trademark) -330, and BYK (registered trademark) -302. , BYK (registered trademark) -UV3500, BYK-306 (manufactured by BYK Japan), polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.
Moreover, it is preferable that a silicone type wet dispersing agent is a silicone type wet dispersing agent containing the compound represented by a following formula (U).

(In the formula, R ⁵ and R ⁶ are each independently a hydrocarbon group having 1 to 200 carbon atoms which may contain an aromatic ring, or — (CH ₂ ) ₃ O (C ₂ H ₄ O) _p ( CH ₂ CH (CH ₃ ) O) _q R ′, n is an integer of 1 to 200, R ′ is an alkyl group having 1 to 12 carbon atoms, p and q are each an integer, and q / p = 0 to 10 is satisfied.)
In addition, as a commercial item of the silicone type wetting and dispersing agent containing the compound represented by the formula (U), BYK (registered trademark) -302 and BYK (registered trademark) -322 (manufactured by Big Chemie Japan Co., Ltd.) can be mentioned. It is done.
When the wet dispersant is contained, the amount thereof is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the radical polymerizable compound (C).

〔wax〕
The water-containing resin composition used in the treatment method of the present invention may contain a wax.
Examples of the wax include paraffin waxes and polar waxes, and these may be used alone or in combination of two or more.
Known paraffin waxes having various melting points can be used as the paraffin waxes. Moreover, as polar wax, what has a polar group and a nonpolar group in the structure can be used, and specifically, NPS (registered trademark) -8070, 9125 (made by Nippon Seiwa Co., Ltd.), Emanon (registered trademark) 3199, 3299 (manufactured by Kao Corporation) and the like.
When the wax is contained, the amount thereof is preferably 0.05 to 4 parts by mass, more preferably 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the radical polymerizable compound (C).

[Thixotropic agent]
A thixotropic agent may be used in the water-containing resin composition in the treatment method of the present invention for the purpose of viscosity adjustment for ensuring workability.
Examples of the thixotropic agent include an inorganic thixotropic agent and an organic thixotropic agent. Examples of the organic thixotropic agent include hydrogenated castor oil type, amide type, polyethylene oxide type, vegetable oil polymerized oil type, interface. An activator system and a composite system using these in combination are exemplified. Specifically, DISPARLON (registered trademark) 6900-20X (Enomoto Kasei Co., Ltd.) and the like can be mentioned.
In addition, examples of the inorganic thixotropic agent include silica and bentonite, and hydrophobic ones such as Leolosil (registered trademark) PM-20L (gas phase method silica manufactured by Tokuyama Corporation), Aerosil (registered trademark) AEROSIL. R-106 (Nippon Aerosil Co., Ltd.) and the like, and examples of hydrophilic ones include Aerosil (registered trademark) AEROSIL-200 (Nippon Aerosil Co., Ltd.). From the viewpoint of further improving thixotropic properties, those obtained by adding BYK (registered trademark) -R605 or BYK (registered trademark) -R606 (made by Big Chemie Japan Co., Ltd.) as a thixotropic modifier to hydrophilic calcined silica. Can also be suitably used.
When the thixotropic agent is contained, the amount thereof is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the radical polymerizable compound (C).

<Storage container>
In the treatment method of the present invention, a solidified body of a water-containing resin composition containing radioactively contaminated water (A) is produced in a radioactively contaminated water storage container, and the opening of the storage container is sealed as it is for safe radiation. It is desirable to have a treatment method that keeps the product until it reaches the performance level. The storage container is not particularly limited as long as it has excellent waterproofness, durability, and radiation resistance, and those known in the art such as metal, plastic, fiber reinforced plastic (FRP), etc. should be used. Can do. More preferably, a glass fiber reinforced plastic container can be used. For example, a storage container formed using a known molding method such as pultrusion molding, hand lay-up molding, filament winding molding, or the like can be used. The shape and size of the storage container are not particularly limited, and various shapes can be employed according to the user's request. From the viewpoint of efficiently dissipating the heat of curing, it is desirable to use a container having a large surface area such as a plate container. If it is a plate-shaped container, since it can also be stored by stacking after sealing an opening part, it is advantageous also from a viewpoint of volume reduction of a storage place.

In the case of using a container made of FRP as the storage container, the resin to be used is not particularly limited, but the radical polymerizable compound (C), epoxy resin, phenol resin, etc. used for preparing the solidified body of the radioactively contaminated water (A) described above Can be used. As the epoxy resin and the phenol resin, those listed in JP-A-2014-139565 can be used, and in addition, “Nuclear Power Equipment Standard Maintenance Standard (JSMES NA1-2004)” issued by the Japan Society of Mechanical Engineers (2004) Lipoxy (registered trademark) H-630 manufactured by Showa Denko K.K. In the case of using a resin that conforms to the above-mentioned standards, it is more preferable to cure the resin according to this because a detailed specification is determined for use.
As the curing agent and the crosslinking agent used for the production of the FRP container, the radical polymerization initiator (F) and those described in JP-A-2014-139565 can be used.
Considering that it is not affected by moisture such as climatic conditions and humidity, it contains the thiol compound (B), the metal compound (M), the radical polymerizable compound (C), and the radical polymerization initiator (F). It is preferable to use the composition to be used as a material for a storage container made of glass fiber reinforced plastic.

[Method of treating radioactive contaminated water]
The method for treating radioactive contaminated water of the present invention includes a step of solidifying the water-containing resin composition.
<Method for preparing water-containing resin composition>
The water-containing resin composition of the present invention is a mixed liquid (I) containing radioactively contaminated water (A), a thiol compound (B), a radical polymerizable compound (C), a filler (D), and a surfactant (E). ) And a radical polymerization initiator (F). From the viewpoint of uniform mixing, Step 1 of obtaining the mixed liquid (i) by mixing the radical polymerizable compound (C) and the thiol compound (B), the radioactively contaminated water (A) and the interface The activator (E) is mixed, and the mixed solution (i) is mixed with the activator (E) to obtain a mixed solution (I), and the mixed solution (I) and the radical polymerization initiator (F) are mixed. A method having Step 3 of mixing is preferable. In this case, the filler (D) and other components added as necessary are preferably mixed in either step 1 or step 2 from the viewpoint of mixing uniformly before the radical polymerization is started. It is more preferable to mix in step 2.
By treating the radioactively contaminated water (A) by the above method, the thiol compound (B) is efficiently coordinated in the vicinity of the metal in the radioactively contaminated water (A) or the metal blended in the filler (D). It becomes possible to make it.
There is no restriction | limiting in particular in the mixing method in each said process, It can carry out by a well-known method. Moreover, the temperature at the time of each mixing is preferably 10 to 40 ° C. from the viewpoint of uniformly mixing and suppressing the deterioration of each component.

<Step of solidifying the hydrated resin composition>
The water-containing resin composition of the present invention is a mixed liquid (I) containing radioactively contaminated water (A), a thiol compound (B), a radical polymerizable compound (C), a filler (D), and a surfactant (E). ) And a radical polymerization initiator (F). By adding the radical polymerization initiator (F), the radical polymerizable compound (C) is cured by polymerization, whereby the water-containing resin composition is solidified.
There are various forms of solidification, and solidification may proceed only by adding the radical polymerization initiator (F). For example, if a thermal polymerization initiator is used, heating is performed as necessary. If light photoinitiator is used, light irradiation may be performed as necessary.
The water-containing resin composition containing the radioactively contaminated water (A) is preferably solidified in the storage container. After the solidified form of radioactively contaminated water (A) is formed, the opening of the storage container is sealed to form a sealed container, and then stored for a long time until the radioactivity is reduced to a safe level. The material used for sealing the storage container is preferably the same as that used for preparing the storage container.

When a storage container made of FRP is used, the storage container is used as disclosed in Japanese Patent Application Laid-Open No. 2014-139565 “A step of applying and supporting a filler that adsorbs and / or shields radioactive substances on an FRP prepreg”. It is also possible to perform maintenance by repairing or reinforcing the damaged part. The resin material at that time is a composition containing the thiol compound (B), the radical polymerizable compound (C), the radical polymerization initiator (F), and the metal compound (M) so as not to be affected by water. Is preferably used.
The storage container enclosing the solidified radioactively contaminated water (A) may be buried and stored in the ground at the final disposal site. It is also possible to release the storage container into space and dispose of it.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not restrict | limited by an Example.
The raw materials used in Examples and Comparative Examples are as follows.

<Radioactive contamination water (A)>
・ Water (A-1)
・ Heavy water (A-2)
Radioactive contaminated water or tritium water was replaced with water or heavy water.

<Thiol compound (B)>
-Bifunctional secondary thiol compound, “Karenz MT (registered trademark) BD1” (1,4-bis (3-mercaptobutyryloxy) butane, molecular weight 299.43), <Radically polymerizable compound (C )>
・ Vinyl ester resin Lipoxy (registered trademark), "NSR-112" (without styrene), Showa Denko K.K.

<Filler (D)>
・ No. 6 silica sand (D-1)
・ Portland cement JIS standard product, made by HOKUSEI Cement, ordinary cement (D-2)
<Surfactant (E)>
・ Sodium dialkylsulfosuccinate, “Perex OT-P”, manufactured by Kao Corporation <Radical polymerization initiator (F)>
-Cumene hydroperoxide, “Park Mill H-80”, manufactured by NOF Corporation

<Metal compound (M)>
・ Cobalt octylate, “hexoate cobalt” (cobalt content 8% by mass, molecular weight 345.34 in the total product), manufactured by Toei Chemical Co., Ltd. <other ingredients>
・ Curing retarder Citric acid, Wako Pure Chemical Industries, Ltd.

<Examples 1-5, Comparative Examples 1-5>
Example 1
After adding and stirring 1 part by weight of the metal compound (M) at room temperature to 100 parts by weight of the radical polymerizable compound (C), 0.5 part by weight of the thiol compound (B) is added and stirred to mix. A liquid (i) was obtained. 25 parts by mass of 1% by weight surfactant obtained by further mixing water (A-1) and surfactant (E) with the mixed liquid (i), 250 parts by mass of filler (D-1), and filler (D-2) 50 parts by mass was added and stirred, to obtain a mixed liquid (I). 1 part by mass of the radical polymerization initiator (F) was added to and stirred with respect to the mixed solution (I) to obtain a water-containing resin composition. The weight loss rate of the water-containing resin composition was measured. The results are shown in Table 1.
In addition, it confirmed that the obtained water-containing resin composition solidified in about 30 minutes at 25 degreeC after radical polymerization initiator (F) addition.

-Examples 2-5, Comparative Examples 1-5
A water-containing resin composition was obtained in the same manner as in Example 1 except that each component was blended according to the description in Table 1. The weight loss rate of the water-containing resin composition was measured. The results are shown in Table 1.
In Comparative Examples 3 and 4, since the water-containing resin composition did not cure, the weight reduction rate could not be measured.

<Measurement of weight loss rate>
The water-containing resin compositions obtained in the examples and comparative examples were poured into a mold having a square of 4 cm on a side and a thickness of 3 mm to obtain a measurement target sample (a). The weight of the sample (a) when poured into the mold was measured. About this sample (a), each weight reduction | decrease rate was measured as shown below.
(1) Weight reduction rate A (%)
The sample (a) was dried at 25 ° C. for 12 hours to obtain a sample (b), and the weight reduction rate (%) after drying was calculated.
The weight loss rate A is calculated as follows.
100 × (weight of sample (a) −weight of sample (b)) / weight of sample (a) (2) cumulative weight reduction rate B (%)
The sample (b) was dried in an oven at 80 ° C. for 6 hours to obtain a sample (c), and the cumulative weight loss rate (%) after drying was calculated.
Calculation of the cumulative weight reduction rate B is as follows.
B = 100 × (weight of sample (a) −weight of sample (c)) / weight of sample (a) The calculation of the moisture reduction rate B ′ (%) is as follows.
B ′ = 100 × (weight of sample (a) −weight of sample (c)) / weight of water in sample (a) (3) cumulative weight reduction rate C (%)
Remove the sample (c) from the mold, measure the weight of the cured product so that there are six pieces, and then dry the pieces in an oven at 100 ° C. for 2 hours to obtain a sample (d). The cumulative weight loss rate (%) of was calculated.
Calculation of the cumulative weight reduction rate C is as follows.
C = 100 × (weight of sample (a) −weight of sample (d)) / weight of sample (a) Calculation of moisture reduction rate C ′ (%) is as follows.
C ′ = 100 × (weight of sample (a) −weight of sample (d)) / weight of moisture in sample (a)

According to the method for treating radioactive contaminated water of the present invention, it was found that the radioactive contaminated water can be solidified in a short time. Further, it was found that the obtained solidified product has a high water retention effect because of its low weight loss rate, that is, it can be stably stored.
On the other hand, Comparative Examples 1, 2, and 5 in which the surfactant (E) was not blended had a higher weight reduction rate than the Examples, and the water retention effect was low. Moreover, the comparative example 3 which does not mix | blend a metal compound (M) and the comparative example 4 which does not mix | blend a thiol compound (B) did not confirm hardening of a water-containing resin composition.

  According to the treatment method of the present invention, radioactively contaminated water can be efficiently solidified and stably stored for a long period of time. Furthermore, by sealing this solidified body in a storage container and storing it, it can be appropriately managed until the radioactivity reaches a safe level.

Claims (11)

A method for treating radioactive contaminated water comprising a step of solidifying a water-containing resin composition containing radioactive contaminated water (A),
The water-containing resin composition is obtained by adding a radical polymerization initiator (F) to a mixed liquid (I) containing radioactively contaminated water (A),
The mixed liquid (I) is a radioactively contaminated water (A), one or more thiol compounds (B) selected from a secondary thiol compound (B1) and a tertiary thiol compound (B2), a radical polymerizable compound (C ), Filler (D), and surfactant (E),
The water-containing resin composition is 5 to 50 parts by mass of the component (A) with respect to 100 parts by mass of the component (C), and 100 parts by mass of the components (A) to (F). E) The processing method of radioactive contamination water containing 0.05-10 mass parts component.   The water-containing resin composition further includes at least one metal M selected from Group 1 to Group 2 metal elements, Group 3 to 12 metal elements, Group 13 to 14 metal elements, rare earth metal elements, and bismuth. The processing method of the radioactive contamination water of Claim 1 containing the metal compound (M) containing this.   Step 1 of obtaining a mixed liquid (i) by mixing the radical polymerizable compound (C) and the thiol compound (B), mixing the radioactively contaminated water (A) and the surfactant (E), It has the process 2 which obtains the said liquid mixture (I) by mixing the said liquid mixture (i) to this, and the process 3 which mixes the said liquid mixture (I) and the said radical polymerization initiator (F). Item 3. A method for treating radioactively contaminated water according to Item 1 or 2.   The thiol compound (B) is 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5-tris [2- (3-mercaptobutyryl). Oxyethyl)]-1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, trimethylolethane tris (3-mercaptobutyrate) and trimethylolpropane tris (3-mercaptobutyrate) The method for treating radioactive contaminated water according to any one of claims 1 to 3, which is at least one selected from   The hydrated resin composition contains 0.01 to 15 parts by mass of the thiol compound (B) and 10 to 500 parts by mass of the filler (D) with respect to 100 parts by mass of the radical polymerizable compound (C). The processing method of the radioactive contamination water of any one of Claims 1-4.   The radioactively contaminated water (A) is tritium water from which radioactive metals have been removed, Group 1 to 2 metal elements, Group 3 to 12 metal elements, Group 13 to 14 metal elements, rare earth metal elements, The processing method of the radioactive polluted water of any one of Claims 1-5 which mix | blends the metal compound (M) containing the at least 1 sort (s) of metal M chosen from bismuth.   The radioactively contaminated water (A) is tritium water from which radioactive metals have been removed, and the filler (D) is a metal element of Group 1 or 2, a metal element of Group 3 to 12, or a metal of Group 13 to 14. Radioactive contaminated water according to any one of claims 1 to 5, which is a blend of a metal compound (M) containing at least one metal M selected from an element, a rare earth metal element, and bismuth. Processing method.   In the storage container of radioactively contaminated water, the radioactively contaminated water (A) is solidified by the treatment method according to any one of claims 1 to 7, and then the opening of the storage container is sealed and stored. To treat radioactively contaminated water.   The method for treating radioactive contaminated water according to claim 8, wherein the storage container is made of glass fiber reinforced plastic.   When the storage container is made of glass fiber reinforced plastic, the storage container includes the thiol compound (B), the radical polymerizable compound (C), the radical polymerization initiator (F), and the metal compound (M The method of treating radioactive contaminated water according to claim 9, wherein the material is made of any material selected from a resin composition containing epoxy), an epoxy resin, and a phenol resin.   The method for treating radioactive contaminated water according to any one of claims 8 to 10, wherein the storage container is buried in the ground.