RU2576331C1 - Method of disposal of toxic and radioactive wastes - Google Patents

Abstract

FIELD: protective equipment.

SUBSTANCE: invention relates to techniques for treatment of toxic and radioactive substances and can be used in development of field deposits with filling of mined space. During erection of envelop from buses the internal clearance between them and containers is filled with construction foam based on liquid pre-polymer with propellant forming rigid polyurethane. Foam supply height is accepted equal to half the height of protective envelope when the whole volume of foam is supplied simultaneously.

EFFECT: technical result consists in reduction of labour intensity when creating envelops and reduced risk of corrosion of containers.

1 cl, 1 dwg

Description

The invention relates to technologies for the treatment of toxic and radioactive technologies and can be used in the development of deposits with the laying of the developed space.

Known underground storage of radioactive waste (RF patent No. 2118857, publ. 09/10/1998). Underground storage of radioactive waste includes mine workings located in permafrost. Solid radioactive waste is disposed in the working volume of the mine workings. A liquid reservoir is formed at the bottom of each mine. The drive is separated from the working volume of the mine by a layer of fluid-impervious material with a low coefficient of thermal conductivity.

The disadvantage of this method is the narrow scope associated with the possibility of use only in areas of permafrost.

A known method of the disposal of toxic waste in mine workings (RF patent No. 2118459, publ. 08/27/1998). The method of burial of toxic waste in mine workings involves the formation of chambers separated by interchamber pillars, drilling of large diameter wells, placement of containers with toxic waste in wells. New is that wells for the placement of containers with waste are drilled in the soil of disposal chambers. At the same time, discharge slots with a depth not less than the depth of the wells pass in the salt column along the contour of the chambers. After placing containers with waste in the wells, the gaps between them are filled with liquid insulating material, insoluble in water.

The disadvantage of this method is the high complexity of drilling wells and the formation of cutting gaps.

A known method for the disposal of supertoxic industrial wastes (RF patent No. 2317160, publ. 02.20.2008). A method of disposing of supertoxic industrial wastes involves sequentially placing a waterproof screen, compacting it, stacking and compacting waste, coating the waste with a second waterproof screen, compacting and filling it with a layer of soil and plant soil, followed by planting. As a waterproof screen, an insulating material IM-1 is used, containing oil sludge, limestone in small-sized form, drilling waste, clay rocks, biological products, impregnated with liquid bitumen or tar. Before laying from supertoxic waste, cemented blocks are formed in a humid environment at 40-60 ° C for 1-3 days, including: supertoxic waste, Portland cement, river sand, insulation material IM-1 in the following ratio of components, wt. hours: supertoxic waste - 1 wt. hours, Portland cement - 0.1-0.3 wt. hours, river sand - 0.1-0.3 wt. o'clock, the insulating material IM-1 - 0.05-0.1 wt. hours, which are covered with liquid bitumen or tar for 3-5 minutes, then cooled and sent to the laying.

The disadvantage of this method is the high complexity and high consumption of materials.

There is a method of disposing of solid radioactive waste in near-surface burial sites (RF patent No. 2366011, publ. 08/27/2009). When disposing of waste, the cemetery is deboned from below and from the sides with a layer of 0.5 to 1.5 m of a compacted clay mixture with bauxite sludge. After filling the repository with waste, they are dubbed from above so that the vertical layout of this waterproofing layer provides a drain of atmospheric precipitation. Bauxite sludge is obtained by calcining bauxite ore together with lime and soda and subsequent washing with water from soluble sodium compounds.

The disadvantage of this method is the presence of specific ingredients and the high complexity of the processes for using the method.

Known reinforced concrete storage of radioactive waste (RF patent No. 2242813, publ. 12/20/2004). The inventive reinforced concrete storage of radioactive waste includes surrounded by a drainage ditch made in the soil mass, tapering from top to bottom capacity with a flat bottom. On the bottom there is a reinforced concrete tank divided into compartments with walls, a bottom and a lid formed by floor slabs. Moreover, the inner surface of the walls and bottom of the reinforced concrete, divided into compartments of the tank is covered with a waterproof lining (insulating material). A reinforced concrete tank divided into compartments is located below the surface of the soil mass. A layer of sand is located above a reinforced concrete reservoir divided into compartments; horizontal vapor-liquid thermosiphons are installed above its lower surface. A heat insulator is located along the upper and lateral surfaces of the sand layer, and a drainage ditch is located along the perimeter of the sand layer. The space between the walls of a container tapering from top to bottom and the walls of a reinforced concrete tank divided into compartments, as well as between the cover of a reinforced concrete tank divided into compartments and the surface of a tank tapering from top to bottom, is filled with dispersed soil.

The disadvantage of this method is the design complexity and high complexity of the creation.

A known method of the disposal of toxic and radioactive waste, (RF patent No. 2532951, publ. November 20, 2014), adopted as a prototype. The method includes the formation of chambers separated by inter-chamber pillars, the placement of containers in sarcophagi erected from spent tire tires of self-propelled heavy vehicles by stacking them and fastening them together, isolating adjacent workings with waterproofing jumpers and filling with a hydraulic hardening tab, accepting the height of the sarcophagi less than the estimated level of shrinkage bookmarks, and the height of the stacking piles of containers in the sarcophagi is less than the height of the sarcophagi.

The disadvantage of this method is the high complexity of creating sarcophagi and the possibility of intense corrosion of containers.

The technical result of the invention is to reduce the complexity of creating sarcophagi and reduce the likelihood of corrosion of containers.

The technical result is achieved by the fact that, as the sarcophagi are erected from the tires, the internal gap between them and the containers for fastening is filled with a mounting foam based on a liquid prepolymer with a propellant, followed by the formation of a rigid polyurethane foam, and the foam supply height is equal to half the height of the sarcophagus from the tires when foam is applied to the entire sarcophagus at once.

The method of disposal of toxic and radioactive waste is illustrated in figure 1, which shows a layout of containers in the filling array, a cross section of the laid space, where:

1 - mine workings in the form of a chamber, obtained as a result of mining;

2 - interchamber pillars;

3 - sarcophagi, erected from the waste tires of heavy vehicles by laying them in a stack and fastening together;

4 - hydraulic hardening tab;

5 - waste container;

6 - internal gap between tires and containers filled with polyurethane foam based on a liquid prepolymer with a propellant, followed by the formation of rigid polyurethane foam.

When pouring polyurethane foam based on a liquid prepolymer with a propellant after the liquid prepolymer leaves the container under the influence of air humidity and surface moisture (which is typical for mines and mines, which almost always have significant humidity), a polymerization (solidification) reaction occurs. Ultimately, a rigid polyurethane foam is formed with increased mechanical strength (in relation, for example, to stable foams), which has expansion properties with filling all the places. Polyurethane foams are currently widely used in construction and, after hardening, have mechanical strength and other properties. For example, IZOFLEX polyurethane foam has the following properties: solidification time 12 hours, tensile strength 0.1 MPa, adhesiveness 0.1 MPa, heat resistance -50- + 130 °, fire hazard class - self-extinguishing. Use temperature - from +5 to + 30 ° C. The density of the resulting foam is about 18 kg / m ³ . 0.75 L of free-flowing foam IZOFLEX forms about 45 L of foam. Thus, based on the basic properties of the foam, the possibility of its effective use in the underground space is visible, since in mines there is almost always high humidity, which contributes to the rapid hardening of the liquid prepolymer displaced by the propellant. High thermal stability and self-extinguishing properties will increase the safety of work. Due to the production of foam directly in the worked out space, the method operations are greatly simplified and labor costs for erecting sarcophagi from tires are reduced. In addition to ease of use, mounting foam has expansion properties that are most effective in free and wet mine openings. Therefore, the height of the foam supply is taken equal to half the height of the sarcophagus from the tires when feeding foam to the entire sarcophagus immediately, since mounting foams based on liquid prepolymer have a relatively identical ability to increase the volume, on average, twice. The properties of increasing the volume of filled foam will contribute to the effective fastening of containers 5 inside the sarcophagi from waste tires 3, which reduces the likelihood of corrosion of containers 5 by eliminating the formation of air gaps between the tires of the sarcophagus and the backfill array. To fill the internal space between the tires and containers 5, professional and unprofessional mounting foams from Chemlux, Domos, Formula, Krass, Panafix, Bartons, Macroflex, etc. can be used. When working with polyurethane foam, workers should use personal protective equipment, at least rubber gloves, to prevent contact between the foam and hands.

The method of disposal of toxic and radioactive waste is as follows. The mine workings are formed by mining in the form of chambers 1, separated by interchamber pillars 2. Then, containers 5 are placed in chambers 1 in sarcophagi 3, erected from used wheel tires of heavy vehicles. Sarcophagi 3 are formed by stacking and fastening the tires together by filling the internal gap 6 between them and the containers with a mounting foam based on a liquid prepolymer with a propellant, followed by the formation of rigid polyurethane foam. The width of the container is taken no more than 0.9D, where D is the inner diameter of the tire, m. This clearance will avoid the difficulties associated with the installation of containers 3 in the inner space of the sarcophagi 5. The height of the foam is taken equal to half the height of the sarcophagus 3 of the tires when feeding the foam to the entire sarcophagus at once. After installing the required number of sarcophagi 3 inside the chambers 1, the adjacent workings are isolated with waterproofing jumpers (not shown conditionally). Then, the remaining space between the sarcophagi 3 and the chambers 1 is filled with a hydraulic hardening tab 6. The height of the sarcophagi 3 is less than the calculated level of shrinkage of the tab 6, and the stacking heights of containers 5 in the sarcophagi 3 are less than the height of the sarcophagi 3.

The use of this method of disposal of toxic and radioactive waste provides the following advantages:

- reducing the complexity of creating sarcophagi;

- reducing the likelihood of corrosion of containers;

- increasing the safety of the construction of sarcophagi and the laying of works.

Claims (1)

A method for the burial of toxic and radioactive waste, including the formation of mine workings in the form of chambers separated by interchamber pillars, placing containers in sarcophagi erected from spent wheel tires of heavy-duty self-propelled vehicles by stacking them and fastening them together, isolating adjacent workings with waterproofing jumpers and filling with hydraulic hardening bookmark, the acceptance of the height of the sarcophagi is less than the estimated level of shrinkage of the bookmark, and the height of the stacking containers rocophagi are less than the height of the sarcophagi, characterized in that as the sarcophagi are erected from the tires, the internal gap between them and the containers for fastening is filled with a mounting foam based on a liquid prepolymer with a propellant, followed by the formation of a rigid polyurethane foam, and the height of the foam supply is taken equal to half the height of the sarcophagus from the tires at applying foam to the entire sarcophagus immediately.

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