DE2363475C3 - Process for processing solid waste containing radioactive or toxic substances for safe handling, transport and disposal - Google Patents

Description

Features solved

The solid waste materials produced with the aid of the mixture to be used according to the invention Polymers are distinguished from those containing waste material obtainable by the known processes Polymerizaten through a significantly improved leaching and washout resistance and a decisive improved thermal resistance. Compared to those in the German Offenlegungsschrift 22 12 574, the method according to the invention also offers the important advantage that both solid waste in the dry state, as well as water, aqueous solutions, organic liquids or solid waste containing organic solutions can be solidified equally well. aside from that The mixture to be used according to the invention is distinguished from the other polymerization processes by a shorter polymerization time at room temperature.

The method according to the invention is suitable for solidifying radioactively contaminated or toxic ones Waste materials such as B. in nuclear technology in the preparation or separation of radioactive substances or incurred when cleaning the equipment used.

Examples of radioactively contaminated waste are:

Activated carbon, e.g. B. from exhaust air filter systems, from the post-cleaning of evaporator condensers, od. Ashes, e.g. B. from incineration plants for burning radioactive waste,

Metal chips, e.g. B. from the fuel assembly production and the mechanical processing of contaminated equipment and systems, precipitation sludge, such. B. from a chemical treatment of radioactive waste water,
Apparatus parts, e.g. B. from the maintenance of contaminated systems and devices,

Precipitation such as B. arise in the storage of radioactive waste solutions.
Deposits such as those found in B. in storage containers, pipelines or pumps for radioactive solutions arise, spent ion exchangers, z. B. from the cleaning of radioactively contaminated water cycles in nuclear reactors and fuel storage pools.

The following toxic waste materials should be mentioned: cadmium and arsenic compounds, cyanides, compounds of Chromium, mercury and its salts, tin and antimony compounds, thallium compounds, solid waste with pesticides, insecticides, fungicides, food poisons, etc. Both dry waste materials as well as waste materials containing water or aqueous solutions and organic liquids or organic solutions are solidified.

Preferably, the dry waste materials are in a range between 30 and 70 percent by weight, based on the mixture (waste materials and polymerization mixture), the styrene in a range between 80 and 98 percent by weight, based on the polymerization mixture, the divinylbenzene in a range between 1 and 15 percent by weight, based on the polymerization mixture, and the polymerization catalysts in a range between 0.5 and 5 percent by weight, based on the polymerization mixture used.

Solid waste materials that contain water or aqueous solutions are made with emulsifiers and / or swellable bzv /. absorbent solids are added before they are mixed with the polymerization mixture (monomer mixture) be mixed in the weight ratio range of solids to polymerization mixture between 2: 1 and 1: 1. In this case, it is advantageous to use for better mixing of the monomer mixture with the in the solid-containing water to emulsifiers. Particularly suitable as such are:

Anion-active surfactants, especially alkyl sulfonates, alkyl and arylbenzene sulfonates and non-ionic surfactants, especially ethoxylated and propoxylated fatty alcohols, fatty acids and fatty amines.

ίο also come for the method according to the invention swellable or absorbent solids in question, those with radioactively contaminated or toxic liquids are soaked

As swellable or absorbent solids, carrier substances are to be mentioned, which due to their physical Structure can absorb liquids. Organic adsorbents are predominantly used as swellable solids macroporous crosslinked copolymers, and in particular ion exchangers. As absorbent Substances are also inorganic gels, such as. B. silica gel, silica gel, alumina gel or kieselguhr, zeolites and in particular vermiculite is used.

Solid waste in a mixture with organic liquids or organic solutions are mixed with the polymerization mixture with sorbents added in the weight ratio range of solids to monomer mixture between 2: 1 and 1: 1. as Sorbents are vermiculite or macroporous styrene-divinylbenzene copolymers used.

The process according to the invention is generally carried out in such a way that the solid is removed in portions, preferably without stirring, at room temperature to form a reaction mixture from the monovinyl compound and the polyvinyl compound.

The ratio of monomer mixture to solids can be between 50: 1 and 1: 3, expediently between 2: 1 and 1: 2, vary. When using moist solids it is advantageous to slightly increase the monomer content.

The polymerization is carried out in a manner known per se with the aid of polymerization catalysts. The polymerization catalysts used are also known; Examples include: acetyl peroxide, Benzoyl peroxide, tert-butyl hydroperoxide, cumene peroxide, lauroyl peroxide, azodiisobutyric acid dinitrile, Methyl ethyl ketone peroxide, tetralin peroxide and persulfates. It is preferable to use it of catalysts with low light-off temperature, such. B. Azodiisobutyric acid dinitrile. When using azodiisobutyric acid dinitrile is used with an amount of catalyst between 0.1 and 10 percent by weight, preferably between 0.5 and 5 percent by weight. After the heat tint has subsided the material is cured and the radioactively contaminated or toxic solid is enclosed by the polymer. These mixtures to be polymerized generally solidify to form after 2 to 20 days solid block and can then advantageously remain in the polymerization vessel.

When including aqueous swollen solids, e.g. B. of vermiculite or dried ion exchangers, it has proven to be advantageous to add small amounts of the corresponding dry swellable solid to bind the condensation water that is created by the temperature rise during the polymerization process.
Since the inclusion of radioactively contaminated and toxic

shear solids advantageously without further mixing is carried out in the containers in which the final storage takes place, is due to the small amount of equipment Effort given a high operational identity. The method according to the invention can be used for all solids which even have a high liquid content can apply.

example 1

In a 2001 container, the contents are stored at 25 ° C in a solution of

21.55 kg styrene,
0.75 kg divinylbenzene

(60 percent by weight) and 0.70 kg of azodiisobutyric acid nitrile,

60 kg of radioactively contaminated boiler ash, obtained from an incineration plant for combustible radioactive waste, entered in portions. After 45 ^° C., the mixture solidifies after 2 days and is hardened after 5 days

10

15th

Example 2

In a 2001 container, the contents are stored at 20 ° C in a solution of

56.2 kg styrene, 2.0 kg divinylbenzene

(60 percent by weight) and 1.8 kg of azodiisobutyronitrile

3 kg of azodiisobutyric acid dinitrile and
6 kg of an oleyl alcohol reacted with 18 moles of ethylene oxide

given. A homogeneous solution is made by stirring by hand. 100 kg are added to this solution a radioactively contaminated strongly acidic cation exchanger of the type with 8% divinylbenzene crosslinked polystyrene sulfonic acid entered. At 50 ° C the mixture solidifies after 4 days and hardened after 14 days

Example 5

A) Swelling of a radioactively contaminated
Solution in dried ion exchanger

In a vessel from 2001 will be content

120 kg of a radioactively contaminated approximately 30 weight percent sodium nitrate solution was presented and to that

45 kg of a dried, strongly acidic cation exchanger crosslinked with 2% divinylbenzene given the base of polystyrene sulfonic acid.

The resin is allowed to swell in a solution for 8 hours, the swollen resin is filtered off with suction and the moist product is set for block polymerization.

B) bulk polymerization

In a container with a content of 200 l at 20 ⁰ C are successively

50 kg of a moist, radioactively contaminated mixed-bed exchanger, which in the equivalent ratio of 58 kg from an anion exchanger based on a polyvinyltrimethylammo- 3 kg crosslinked with 2 kg of 4% divinylbenzene nium hydroxide and a cation exchanger on the 6 kg Base is composed of a polystyrene sulfonic acid crosslinked with 8% divinylbenzene, entered. At 35 ° C the mixture solidifies after 2 days and is hardened after 6 days.

Example 3 45 135kg

In a container of 200 l at 22 ° C in 9 kg a solution of

93.7 kg styrene, 3.3 kg divinylbenzene

(60 percent by weight) and 3.0 kg of azodiisobutyronitrile

80 kg of a moist, radioactively contaminated, strongly basic anion exchanger based on a 4% Divinylbenzene crosslinked polyvinylbenzyltrimethylammonium hydroxide registered. At 30 ° C the mixture solidifies after 3 days and is hardened after 6 days.

Styrene,

Divinylbenzene (60 percent by weight),

Azodiisobutyric acid dinitrile and

one reacted with 18 moles of ethylene oxide

Given oleyl alcohol.

A homogeneous solution is produced by stirring by hand. Be in this solution

of the resin containing sodium niirate produced under A) and

of a dried, strongly acidic cation exchanger crosslinked with 2% divinylbenzene based on polystyrene sulfonic acid

using a metering device, entered in portions. The mixture continues to solidify at 45 ° C 3 days and is hardened after about 4 weeks.

Example 6

A) Swelling of a radioactively contaminated
Solution in vermiculite

Example 4

In a container of 200 l
after another

Contents are at 25 ° C

58 kg styrene,
2 kg divinylbenzene (60 percent by weight),

In a vessel from 2001 the contents are kept at 24 ° C

50 kg of a radioactively contaminated 30 weight percent sodium nitrate solution and added
9 kg vermiculite given.

It is allowed to swell for at least 1 hour, the swollen material is suction filtered and the moist product is added

7 8

Polymerization. with

50 kg of a pearl-shaped with 18% divinylbenzene

B) block polymerization and crosslink with 65% isododecane (equ

net on the monomer mixture) is porous

In a container with a capacity of 200 l, 5 made polystyrene ^{are made at 2O 0 C}

after another

well mixed. The mixture is left to swell for 1 hour and then added

53.0 kg of styrene, 25 ° C to a solution of

2.0 kg divinylbenzene

(60 percent by weight) and io 93.7 kg of styrene,

0.3 kg azodiisobutyric acid nitrile 3.3 kg divinylbenzene

(60 percent by weight) and

given. Stirring by hand makes 3.0 kg of azodiisobutyric acid dinitrile. gene solution produced. In this solution 39 kg

of the product obtained under A) simultaneously with 2 kg of 15 At 40 ° C., the mixture has solidified after 3 days and vermiculite, if necessary using a dosing device, cured after 12 days, added in portions. At 60 ⁰ C

the mixture solidifies after 4 days and after about 4 is Example 10

Cured weeks. After heat of reaction occurs

a temporary temperature rise for several days increase by 30 to 40 ° C. a solution of

Example 7 43.0kg styrene,

1.5 kg of divinylbenzene (60 percent by weight), in a container of 200 liters at 20 ° C 25 1.4 kg of azodiisobutyric acid dinitrile and

120.0 kg of a pulverized 30 before the polymerization reaction kg of a radioactively contaminated pump oil nert, radioactively contaminated broken glass

with registered.

50 kg of a pearl-shaped with 18% divinylbenzene

cross-linked and with 65% isododecane (calculated 30 At 40 ° C the mixture solidifies after 2 days on the monomer mixture) porous solid block. Both leached by distilled made polystyrene intimately mixed. No radioactivity was found in water after 14 days

posed.

The mixture is left to swell for 1 hour and is added at 22 ° C
Solution of 35 to Example 11

140.5 kg of styrene, in a container with a capacity of 200 liters at 25 ° C in

5.0 kg divinylbenzene a solution of

(60 percent by weight) and

4.5 kg of azodiisobutyric acid dinitrile. 40 43.0 kg styrene,

1.5 kg divinylbenzene

At 35 ° C the mixture solidifies after 2 days and is (60 percent by weight) and

cured after 12 days. 1.4 kg of azodiisobutyric acid dinitrile

Example 8 45 100.0 kg of calcium orthoarsenate (Ca3 (As3O4) 2) entered. At 35 ° C the mixture solidifies after 3 days and in a container of 200 liters at 20 ° C is hardened after 8 days.

37.5 kg radioactively contaminated pump oil with example 12

25.0 kg vermiculite 50

In a container with a capacity of 200 l at 2O ⁰ C in

Mix well for 10 minutes. Then you give a solution of at 24 ° C a solution of

43.0 kg styrene,

107.7 kg styrene, 55 1.5 kg divinylbenzene

3.8 kg divinylbenzene (60 weight percent) and

(60 percent by weight) and 1.4 kg of azodiisobutyric acid dinitrile

3.5 kg of azodiisobutyric acid dinitrile.

100.0 kg cadmium sulfate (CdSO ₄ ) entered. At 35 ⁰ C

At 35 ° C the mixture solidifies after 3 days and at 60 ° the mixture solidifies after 4 days and is after 8 days hardened after 8 days hardened to a solid block.

Example 9 Example 13

In a container of 200 1 capacity C 65 are at 25 ° in a container of 200 I content is at 25 ⁰ C in

a solution of

50 kg of a 10 percent by volume radioactively contaminated tributyl phosphate solution in isodecane 43.0 kg styrene,

9

1.5 kg divinylbenzene (60 percent by weight), 1.4 kg of azodiisobutyric acid dinitrile and 100.0 kg of a radioactively contaminated silica gel (Grain size from 0.1 to 0.3 mm),

that accrues from kerosene cleaning, entered and mixed well. At 40 ^° C., the mixture has solidified after 2 days and hardened to form a solid block after 8 days.

10

Example 14

In a container with a capacity of 200 liters at 25 ° C in a solution of

15th

120 kg styrene,
4 kg divinylbenzene,
4 kg of azodiisobutyric acid dinitrile. 12 kg of the sodium salt of dodecylbenzenesulfonic acid

and 20

100 kg of diatomaceous earth with 15 percent by weight of radioactively contaminated water

given and mixed well. At 30 ^° C., the mixture solidifies after 4 days and is hardened after 8 days.

30th

35

40

45

50

85

CO

C5

Claims (9)

Patent claims: 1. Process for processing solid waste containing radioactive or toxic substances for safe handling, transport and disposal, in which the waste with a polymerizable Mixture of styrene, another copolymerizable compound and polymerization catalysts is mixed and converted into a solid block by polymerization, thereby characterized in that divinylbenzene is used as a further copolymerizable compound and that based on the mixture of waste and polymerization mixture, the solid waste in a range between 2 and 75 percent by weight, and based on the polymerization mixture Styrene in a range between 60 and 99 percent by weight, divinylbenzene in a range between 0.5 and 30 percent by weight, and the polymerization catalysts in a range between 0.1 and 10 percent by weight. 2. The method according to claim 1, characterized in that based on the mixture of waste and polymerization mixture of the waste in solid form in a range between 30 and 70 percent by weight and, based on the polymerization mixture, the styrene in a range between 80 and 98 percent by weight, the divinylbenzene in a range between 1 and 15 percent by weight and the Polymerization catalysts are used in a range between 0.5 and 5 percent by weight. 3. The method according to claim 1, characterized in that the solid waste, the water or Contains aqueous solutions, mixed with emulsifiers and / or swellable or absorbent substances before it goes with the polymerization mixture in the weight ratio range waste to polymerization mixture is mixed between 2: 1 and 1: 1. 4. The method according to claim 3, characterized in that as emulsifiers or anionic nonionic surfactants can be used. 5. The method according to claim 4, characterized in that the anionic surfactants are alkyl sulfonates, Alkyl or arylbenzenesulfonates and, as nonionic surfactants, ethoxylated or propoxylated fatty alcohols, Fatty acids or fatty amines can be used. 6. The method according to claim 3, characterized in that dried as absorbent substances Ion exchangers, inorganic gels, kieselguhr or vermiculite can be used. 7. The method according to claim 6, characterized in that the inorganic gels or silica gel Alumina gel can be used. 8. The method according to claim 1, characterized in that the solid waste, the organic liquids or contains organic solutions, sorbents are added before being added to the polymerization mixture in the weight ratio range waste to polymerization mixture between 2: 1 and Is mixed 1: 1. 9. The method according to claim 8, characterized in that the sorbents are vermiculite or macroporous Styrene-divinylbenzene copolymers can be used. The invention relates to a method for processing of solid waste containing radioactive or toxic substances for safe handling, transportation and disposal, in which the waste with a polymerizable mixture of styrene, another copolymerizable compound and polymerization catalysts and mixed into one by polymerization solid block is transferred. In technology, especially in nuclear energy, fall Waste materials that are highly toxic or radioactively contaminated and which, if stored or transported require treatment that prevents them from entering the biocycle. It is known to collect such solid waste such. B. Falling sludge, exhausted ion exchangers, ashes and combustion residues, metal shavings, etc. in containers to store or to mix with cement paste and store them enclosed in cement. From the German Offenlegungsschrift 22 12 574, from which the invention is based, is a method for conditioning radioactive waste known, according to which the waste is in the form of dry powder, in a at room temperature polymerizable resin mixed and this resin with a monomer, z. B. styrene, to a solid Block polymerized in the German Offenlegungsschrift 17 69 911 is a process for the concentration of aqueous solutions and suspensions of radioactive waste described, according to which this in eihgedickter form with polymeric alcohols to a rubber-like homogeneous bodies are solidified. From the German Offenlegungsschrift 22 63 676 it is known aqueous Solutions by adding vinyl monomers and catalysts and subsequent polymerization in Transferring radiation-absorbing, no longer flowable gels. However, storage in containers has proven to be problematic because of the corrosion phenomena on the containers. The disadvantages of inclusion in cement are the associated large volumes of waste, the poor setting ability with respect to the waste materials to be enclosed, and poor leaching behavior of the waste materials enclosed in the cement. According to the processes described in German Offenlegungsschrift 22 12 574 and 17 69 911, polymers are obtained in which the leaching behavior of the polymerized radioactive waste does not ensure that the polymers are safely dumped.
The invention is based on the object of creating a method for processing solid waste containing radioactive or toxic substances, with the aid of which radioactive or toxic solid waste or solid waste containing radioactive or toxic substances can be irreversibly transferred to blocks that have a relatively high Have leaching and washout resistance. The solid waste materials should be able to solidify equally well both in the dry state and with a content of water, aqueous solutions or organic liquids or organic solutions. The method should be able to be carried out by semi-skilled workers only in a short time without a great deal of equipment and costs. It should lead to solidification products that ensure safe handling and safe transport to a final storage facility. According to the invention, this object is achieved by what is stated in the characterizing part of patent claim I.