Store soil and plant residues, contaminated with radioactive isotopes of strontium-90 and cesium - 137

 

(57) Abstract:

The invention relates to containers storage of soil or plant residues, contaminated with radioactive isotopes of strontium and cesium in natural soils, and can be used for the construction of a system of man-made barriers limiting distribution in surface and ground waters, soils radioactive isotopes. The technical result of the invention is the construction of simple, reliable construction of storage tanks in loose soils to store and purification of soils contaminated with isotopes of strontium and cesium. The problem is solved using the storage design for soils contaminated with isotopes of strontium and cesium in the form of pit placed on the walls and bottom of the clay layer. A distinctive feature of the store is that the quality of the clay used layer montmorillonite clay, on which is placed a layer of ash powder ironstone and a layer of gravel gypsum limestone gravel. The components of a two-insulating layers is taken in the ratio 1 : 1. 1 C.p. f-crystals, 1 Il.

The invention relates to containers storage of soils and R construction system technogenic geochemical barriers, limiting distribution in surface and ground waters and soils of radioactive isotopes.

Known near-surface method of disposal of radioactive waste (RO) in betonirovannaa trenches, which are placed in containers with low activity waste. There is a method of disposal of RO in the mines, horizontal underground mine workings and boreholes where the containers with medium - and high-level RO (Nuclear energy, environment and people. International atomic energy Agency. Vienna, 1986, S. 109-129).

In both cases, for better isolation of the waste from the environment held engineering (man-made) barriers permeable to aqueous solutions of clay, sometimes mixed with sand fraction (usually quartz sand). This material is placed in the bottom of the landfill, between the containers and the walls of the store, as well as for overlapping burial ground from above.

The disadvantage of this storage is complicated in structure and expensive insulation for storage tanks with RO.

Known structure to implement the method of storage of radioactive tailings, which is as follows: original pressed raissadat the formation of two dams from pebbles, height, for example, 4 m And in the lower part of the upper dam form the bypass line, and the side surface dams cover anti-filtration layer is a polyethylene film. Before the top of the dam to form a layer of crushed zeolite capacity of 2.5 m and a height of 3 m, in the upper part of which lay a network of perforated piping (U.S. Pat. RF N 2090946, IPC G 21 F 9/24, 20.09.97 year). This device is taken as a prototype for the invention.

The disadvantages of the known constructions are constructive complexity and high cost of the materials used.

The objective of the invention is the construction of simple, reliable construction of storage tanks in natural friable soils for storage and purification of soil and plant residues, contaminated with isotopes: strontium-90 and cesium-137.

The problem is solved using the storage for soil and plant residues, contaminated with radioactive isotopes of strontium and cesium in the form of pit placed on the walls and bottom of the clay layer.

A distinctive feature of the store is that the quality of the clay used layer montmorillonite clay, ncoi. The components of a two-insulating layers is taken in the ratio 1:1.

The drawing shows a cross section of a store-landfill for solid wastes with radionuclides: strontium-90 and cesium-137. The store is made in the form of excavation in soft soil 1. Multi-layer insulation of the walls and bottom (system technogenic geochemical barriers) includes: 2-layer montmorillonite clay, layer 3 is a mechanical mixture of ash powder ironstone red or sludge in the ratio of 1:1, layer 4-gravel gypsum (Ca (SO42H2O) or anhydrite (CaSO4). Store posted by the soil or plant residues 5, contaminated by radionuclides strontium and cesium. The side of the store surrounded by chopping the dirt embankment 6.

The essence of the invention lies in the fact that the store creates a complex system of technogenic geochemical barriers in the form of layers of different material composition are placed on the bottom and walls of the pit in the following sequence. On bottom of the pit and the walls are covered with a layer of montmorillonite clay 2, which performs the role of infiltration and geochemical sorption barrier: it delays the infiltration flow naturally on the powder ironstone in the ratio of 1:1. The mixture is multifunctional: it creates an alkaline geochemical barrier, which coagulated containing strontium and cesium pulvinate complexes. It performs the task geochemical sorption barrier, which delayed the radionuclides of strontium and cesium. Layer 3 is located on montmorillonite clay 2 and consists of a mixture of ash and ironstone in the ratio of 1: 1. He is an alkaline geochemical barrier for ash creates an alkaline environment. Here coagulated pulvinate complexes containing radionuclides of strontium and cesium. Goethite contained in the layer 3, performs the role of sorption geochemical barrier: it delays the cations of strontium and cesium received from layer 4. Layer 3 is laid gravel gypsum (CaSO42H2O) or anhydrite (CaSO4). The dissolution of these minerals in the solution act ions SO42-that precipitated Sr2+on sulphate geochemical barrier and delay the strontium in this layer in the form of small insoluble crystals SrSO4.

Layer 4 is the substrate that holds the soil or plant residues 5, contact isotopes strontium-90 and cesium-137.

In the proposed design repository repository p is atmospheric rain or snow, wash contaminated substances is carried out throughout their migration through the system technogenic geochemical barriers created in the repository.

Pit storage is simple in construction and consists of affordable and cheap insulation using natural products.

The invention can be used in land reclamation in the area of man-made pollution by radionuclides strontium and cesium.

1. Store soil and plant residues, contaminated with isotopes of strontium-90 and cesium-137, in the form of pit posted on the walls and bottom of the clay layer, characterized in that as the clay it contains a layer of montmorillonite clay, on which is placed a layer of ash powder ironstone and a layer of gravel gypsum limestone gravel.

2. Store under item 1, characterized in that each component layer contains the ingredients in the ratio of 1:1.

 

Same patents:

The invention relates to the disposal of solid radioactive waste in the ground

The invention relates to the field of environmental protection and is intended for disposal of solid radioactive waste with low, middle and high level waste, and toxic waste
The invention relates to the field of waste disposal of radioactive waste

The invention relates to the field of chemical engineering, in particular to the submersible pump installations, and can find application in chemical, petrochemical, and other industries
The invention relates to the protection of the environment, namely the collection and disposal of radioactive waste generated as a result of floating nuclear power plants (PAES)

The invention relates to the field of disposal of radioactive substances

The invention relates to the field of treatment and disposal of soil, soil, bottom sediments of streams contaminated with plutonium isotopes and radionuclides released during accidents during production of underground nuclear explosions in the Northern regions in remote sparsely populated areas

The invention relates to the field of radioactive waste management in nuclear power and industry, and other activities and can be used for long-term storage and/or disposal of moderately and metallovedeniye radioactive waste
The invention relates to the protection of the environment, namely, the cleaning area from radioactive waste, reactor compartments formed by the utilization of nuclear ships, submarines, ships, etc

The invention relates to mining and can be used for the decontamination of radioactively contaminated territories and storage of metal-containing species

FIELD: immobilization of heterogeneous radioactive wastes.

SUBSTANCE: proposed method includes production of dehydrated radioactive sediment and filtrate on filtering centrifuge; heating of dehydrated radioactive sediment at 500 - 600 °C; crushing of products of heating into fragments measuring maximum 30 mm; case-hardening of crushed fragments with high-penetration cement solution which is, essentially, mixture of cement having specific surfaced area of minimum 8000 cm2/g and liquid phase at liquid phase-to-cement mass proportion of 0.6 - 1.4; for the final procedure mixture obtained is cooled down.

EFFECT: reduced amount of radioactive wastes, enhanced radiation safety, and reduced power requirement.

2 cl, 1 tbl, 2 ex

FIELD: treatment of heterogeneous liquid radioactive wastes.

SUBSTANCE: proposed method includes extraction of radium from radioactive oil slimes by means of hot water, acid or alkali solutions. Before doing so radioactive oil slime is subjected to recovery annealing with lack of hydrogen in atmosphere of incomplete combustion of carbon and hydrocarbons produced by using oil products. Recovery annealing temperature is maintained between 700 and 900 °C for 1 to 3 h. Annealed oil slime is treated with hot steam and once more with heat steam and sulfuric acid at concentration of the latter between 5 and 10% relative to mass of extracting solution.

EFFECT: enhanced quality of radioactive waste treatment.

4 cl, 1 dwg, 1 tbl, 1 ex

FIELD: recovery of liquid radioactive wastes.

SUBSTANCE: proposed method is used for localizing spent granular, powdered, or milled ion-exchange resins in Na- or H-form in dry or wet condition by including them in solid matrix. Matrix base is made of blast-furnace slag milled to fractions below 0.075 mm and tempered with sodium hydroxide solution of 100 - 150 g/l concentration.

EFFECT: enhanced degree of filling compound with wastes and extended range of its application.

1 cl, 1 dwg, 8 ex

FIELD: decontaminating natural water reservoirs from radionuclides.

SUBSTANCE: proposed method includes introduction of sorbent in contaminated water body. Used as sorbent is zeolite powder or man-produced substance, such as red slime or slime production waste. Mirabilite is used as precipitant and in addition water is decontaminated by using water-plant, such as reed and pondweed planted out in water reservoir in advance.

EFFECT: enhanced efficiency of water reservoir decontamination from radionuclides.

1 cl, 1 ex

FIELD: recovery of liquid radioactive wastes.

SUBSTANCE: proposed method for recovering alpha-active nitric acid solution containing trivalent iron includes pre-concentration of solution being recovered by its evaporation to produce regenerated nitric acid in still bottoms, whereupon still bottoms are neutralized to pH of 1 - 2 and trivalent iron is partially recovered by sodium sulfate until valence forms ratio Fe3+ : Fe2 = 2 : 1 is attained. This is followed by next neutralization with alkali to pH = 10 - 11. Magnetite sediment obtained after settling down is conveyed for curing. Then solution is decanted, clarified solution is magnetically separated and additionally cleaned.

EFFECT: reduced volume of secondary wastes, reduced consumption of chemical agents used for the purpose.

2 cl, 1 tbl, 1 ex

FIELD: radioactive waste processing by the burning method.

SUBSTANCE: the proposed furnace for radioactive waste burning has a case, within of which non less three burning chambers are coaxially located. The chambers have a general chamber for ash reburning. The general chamber is equipped with a fire grate. Each of burning chambers is autonomous, has the device for supply of fuel and oxidizer and is equipped with a fire grate and gate. The chamber for reburning the waste gases is coaxially located in the central part of the furnace. This chamber consists of external and internal cases, forming a labyrinth gas duct. The burning chambers are connected with the chamber for reburning the waste gases by means of gas-escape channels, having unequally-height and unequally-directional levels of location in each two neighboring burning chambers. A pressure-tight lock chamber of cylindrical shape is located over the burning chambers and chamber for waste gas reburning. The lock chamber is general for all burning chambers and is equipped with a cover, charging branch, pipe of exhaust ventilation, heat exchanger, transport system and control unit. The unit for control of the drives of transport system, fire grates, gates and strips is located on the lock chamber cover. The transport system consists of drive and container with a tray and limit switch. The container is fulfilled in the form of horizontally located cylinder. It is foreseen the circular motion of the cylinder. The drive of the transport system is connected with the container by means of an open gearing and is equipped with a gear, located on the output shaft. The output and input pipes for acceptance and unloading of wastes are located with good alignment one under other on the cylindrical surface of the container. The bushings are located on the side end surfaces of the container. The tray has possibility of rotation and has the shape of a bed, repeating the curvature of the internal surface of container case. Besides, the semi-axes are located on the semicircular side end surfaces of the container. These semi-axes together with the container bushings form a movable joint of the type of axis-bushing.

EFFECT: increased economical efficiency, processing efficiency, operation reliability and environment safety.

1 cl, 7 dwg

FIELD: methods of liquid radioactive wastes processing.

SUBSTANCE: the invention is pertaining to the field of liquid radioactive wastes processing. The invention presents a method of neutralization of the low-mineralized and medium-mineralized low-active liquid wastes in the field conditions, which includes the liquid wastes purification by mechanical filters and ultrafilters. The subsequent desalination is conducted by reverse-osmotic filters and an after-purification - by ion-exchange filters with a reactant treatment of the spent ion-exchange resins using potassium ferrocyanide and cobalt salts. Then the treated resin is used as a sorption prefilter, in which they use purification of the wastes before their feeding to the ion-exchange filter. The formed secondary A-wastes are fixed in the stable medium. Advantages of the invention consist is an improved purification efficiency and reduction of the secondary wastes volume.

EFFECT: the invention ensures improved purification efficiency and reduction of the secondary wastes volume.

3 ex

FIELD: nuclear engineering; methods of processing of radioactive effluent.

SUBSTANCE: the invention is pertaining to the field of nuclear engineering, in particular, to the methods of processing of radioactive effluent. The method of processing of the radioactive effluent containing radionuclides in the ionic and colloid forms and ballast components of the mineral and organic nature in the soluted and suspended states provides, that the organic components of the radioactive effluent are oxidized up to a gaseous state, and the mineral ionic components and radionuclides are transformed in a suspended state in the form of hydroxides of metals by feeding of the ozone waste. A stream of the oxygenated waste is separated for a thickened slurry and a liquid phase, using the selective sorbents conduct an afterpurification of the liquid phase from the radionuclides, which have remained in the ionic form. The produced slime and the spent sorbents are transformed into the solid form and sent for a long -term storage. Before treatment with ozone the stream of the radioactive effluent is purified from the suspended particles using its percolation through a mesh filtering material, and before an afterpurification of the liquid phase with the help of the selective sorbents conduct a membrane microstraining with separation from the liquid phase of radionuclides in the colloid form, which are sent back in the stream of the radioactive effluent after injection in it of ozone. The technical effect of the invention consist in an improved purification of the radioactive effluent from radionuclides.

EFFECT: the invention ensures an improved purification of the radioactive effluent from radionuclides.

1 dwg, 1 ex

FIELD: recovery of liquid radioactive wastes.

SUBSTANCE: proposed method for treatment of sulfuric ammonium radioactive solutions includes electrotype coagulation treatment involving passage of radioactive solutions through vibroliquefied iron-coke galvanic pair. Radioactive solution pH is corrected and radionuclide-containing deposit separated. In the process pH of radioactive solutions is corrected in two stages with deposit being separated after each stage. First-stage deposit is mixed up with montmorillonite clay and granules are molded. Then they are dried out and agglomerated to produce glass-ceramics wherein radionuclide-containing deposits are immobilized. Filtrate is treated with foam layer to blow off ammonia and then passed through natural ion-exchanger. Method for immobilizing radionuclide-containing deposit in glass-ceramics includes molding of granules of radionuclide-containing deposit mixed up with montmorillonite clay. Granules are molded in two stages. Core of granule of radionuclide-containing deposit mixed up with montmorillonite clay is produced during first stage and covered with shell of glass-ceramics based on homogeneous mixture of montmorillonite clay and quartz sand, during second stage, quartz sand content of mixture being 10 - 30 mass percent.

EFFECT: enhanced reliability of radioactive waste immobilization.

6 cl, 2 dwg, 1 tbl, 3 ex

FIELD: recovering and decontaminating liquid radioactive wastes.

SUBSTANCE: proposed method includes settling down of source radioactive waste flow to form above-the-sediment liquid and mud. Above-the-sediment liquid is clarified in mechanical filter and filtrate is formed in the process. Filtrate is separated by ultra-filtration to form concentrate which is mixed up with source flow of liquid radioactive wastes and permeate. The latter is separated into brine and dialyzate; the former is concentrated by way of electroosmosis producing radioactive concentrate flow and dilute flow mixed up with permeate flow; the latter is subjected to deep desalting to form decontaminated solution. In the process filtrate coming from mechanical filter is subjected to ion-selective sorption prior to ultrafiltration , then associating dopes are introduced therein. Ultrafiltration is made under forced turbulent conditions and deep desalting of dialyzate is conducted in two stages; first stage includes reverse osmosis and second one, electric deionization of decontaminated solution.

EFFECT: enhanced decontamination degree of solution and ability of recovering highly mineralized wastes.

1 cl, 1 dwg, 1 ex

Up!