Neutralisation method of liquid radioactive wastes of nuclear power plants contaminated with oil products, corrosion products and synthetic surface active substances in field
FIELD: power industry.
SUBSTANCE: method provides for sedimentation of waste in an initial tank with draining of contaminants from surface to an oil product sump, pre-cleaning on mechanical bulk filters with modified nitrogen-containing coals and coarse and fine cleaning microfilters, softening and demineralisation on a reverse-osmosis filter with deposition of wastes in two intermediate tanks. Filtrate of reverse-osmosis filters is supplied for additional cleaning on ion-exchange filters, and concentrate is returned to the first intermediate tank before microfilters as an alkalising reagent prior to saturation as to salts with curing of formed radioactive concentrates by introduction to Portland cement. Coals saturated with oil products are replaced with new ones, and waste ones are burnt with oil products drained from the initial tank, including ash residue in Portland cement together with waste concentrates.
EFFECT: improving strength of cement stone by 1,5-2 times and reliable fixation of radionuclides in it.
The invention relates to the field of decontamination of liquid radioactive waste (LRW) nuclear power plants (NPP), contaminated petroleum products, corrosion products, and synthetic surfactants (detergents), membrane-sorption methods.
During operation of the NPP formed LRW often have elevated contamination by petroleum products, corrosion products and detergents, which are sorbed radionuclides and their concentrations are often ten times higher than the content in the aqueous phase. [Yepimakhov V.N., Chetverikov CENTURIES, Oleinik MS and other Decontamination and preservation of vessels for storage of liquid radioactive waste // THREAD them. A.P. Alexandrov: Annual report on research and production activities. 2006, St. Petersburg., ed. LLC "SRC "Morinth", 2006, p.65-69]. While NPP, as a rule, do not have their own treatment plants and are therefore often forced to clean LRW on the mobile units in the field [Efimov A.A. Leontiev,, Yepimakhov NR. and other tech THREADS to them. Afalexander on radioactive waste management. - Scientific and technical collection "Ecology and atomic energy", 1998, spec. edition, p.40-44].
A known method of purification of liquid radioactive wastes into the field on a mobile unit, comprising a pretreatment on mechanical and ultrafilter, softening the sodium-Katie Etowah filters desalination on electrodialyzer with defending LRW in the source and intermediate containers and purification of the N+-cationite filters, followed by curing the resulting radioactive concentrates by including Portland cement [Sobolev, IGOR Timofeev E.M., Panteleyev V.I. and other Mobile plant for the treatment of mineralized low-level liquid waste. - Atomic energy, 1992, t, issue 6 s-478].
The disadvantage of this method is that when high pollution LRW oil cleanup on ultrafilter ineffective and oil clogged pores in the ion-exchange resins N+-cationite filters, removing the sorbent from the system [Pushkarev CENTURIES, YU.V. Egorov, BORIS Khrustalev. Clarification and decontamination of wastewater by flotation. - M, Energoatomizdat, 1969]
There is a method of treatment of LRW in field conditions at the facility, including pretreatment on mechanical and ultrafilter, softening and desalination by reverse osmosis filters with defending LRW in the source and intermediate containers, purification on ion-exchange filters, and curing the resulting radioactive concentrates included in Portland cement [RF Patent №2144798, bull. No. 2, 2000]. In the technological essence and the achieved technical result of this method is closest to the proposed and selected in which the quality of the prototype.
The disadvantage of this method is that when high pollution LRW oil leakage of the ultrafiltration process starts to prevent the gel polarization [Membrane Separation Processes. Ed. P. Meares. - Amsterdam: Elsevier, 1976], which requires frequent reagent leaching ultrafiltration membranes. As a result, while in an intermediate tank is formed salt of the radioactive concentrate, in the capacity of the original LRW accumulated radioactive concentrate oil and detergents. If salt concentrates the salt content of up to 150 g/l at inclusion in the Portland cement to form a durable, safe during the transportation of cement blocks, cementing received ultrafiltration concentrates petroleum products and detergents (organic content is more than 1 g/l) decrease the quality of the hardened cement compounds [Malasek E., Vojtech O. the Development of methods for solidification of radioactive concentrates. - In the book: Research in the field of disposal of liquid, solid and gaseous radioactive waste and decontamination of contaminated surfaces (proceedings of the IV scientific-technical conference of the CMEA, Moscow, 22-23 December 1976). M: Atomizdat, 1978, VIP, pp.5-20], [Komarov A., Construction materials and products. - M.: Higher school", 1971, 560 S.].
Object of the invention is to provide a method for disposal of liquid radioactive othogonality power plants, oil contaminated with corrosion products and detergents.
The technical result of the invention is to improve the reliability of fixation of radionuclides and improving the quality of the cement compounds.
To achieve the technical result in the method of treatment of LRW NPU oil contaminated with corrosion products and detergents, in the field, including pretreatment on mechanical and membrane filters, desalination by reverse osmosis filters with defending LRW in the source and intermediate containers, purification on ion-exchange filters, and curing the resulting radioactive concentrates included in Portland cement, according to the invention after the assertion of LRW in the source tank is made by draining the upper layer of water pollution in the collection of oil, when carrying out the pretreatment as mechanical filters use conventional filters with modified nitrogen-containing coals, after settling in the first interim capacity LRW serves on the membrane the filters, which use microfilters coarse and fine cleaning, then LRW sent to the second intermediate tank, after settling in the second intermediate tank LRW is directed to the reverse osmosis filters, the concentrate is returned to the first intermediate tank in cachestoreprivate reagent prior to its saturation salts, saturated oil coal extracted from the mechanical filter replace with new, and waste coals burn with the oil drained from the upper layer of the source containers in the collection of oils obtained ash include Portland cement together with saturated salts of reverse osmosis concentrate LRW.
Modified nitrogen-containing coals (MAU) compared with standard activated carbons brands BAU, AG-3, SKT has higher adsorption capacity (5-7 times higher), provide deep cleaning water from oil to 0.05 mg/kg, detergents up to 0.1 mg/kg [TU 0320-001-23363781-01].
The proposed method is illustrated by a drawing, which shows a diagram of the disposal of liquid radioactive waste from nuclear power plants, oil contaminated with corrosion products and surface-active substances in the field.
Technological scheme shown in Fig., includes: the capacity of the original LRW 1, proceedings of petroleum products 2, mechanical filter, filled MAU, 3, the first intermediate tank 4, the second intermediate tank 8, the pumps 5 and 9, the microfilters rough 6 and thin 7 purification, reverse osmosis filter 10, the ion-exchange filter 11 and the capacity of purified water 12.
The method is as follows.
LRW contaminated with oil, about what uchumi corrosion and detergents, after soaking and settling in the tank the original LRW 1 and the drain of the top layer of dirt in the collection of the oil 2 is directed to a pretreatment by gravity on the bulk carbon filter 3, downloaded, modified nitrogen-containing carbon, to remove oil, detergents and dissolved corrosion products (iron and others). The filtrate carbon filter 3 is directed to sludge in the first intermediate tank 4 and the pump 5 to the microfilters rough 6 and 7 for fine cleaning removal of suspended corrosion products. Next, the filtrate microfilters 6 and 7 are sent to defend the second intermediate tank 8 and the pump 9 on the reverse osmosis filter 10 to remove hardness salts and partial demineralization. Softened the filtrate reverse osmosis filter 10 is directed to further demineralization by ion exchange filter 11, and the concentrate is returned to the first intermediate tank 4. The filtrate ion exchange filter is sent to the capacity of purified water 12 for averaging and determining the residual specific activity and subsequent discharge. Because bicarbonate ions are in reverse osmosis filtrate (dissolved CO2virtually no delayed membranes, passing freely to the filtrate, and interacting with the water molecules, re-forms in it, the bicarbonate ions), then concentrate on ratesmortgage filter 10, doing in the first intermediate tank 4, podslushivaet (as alkaline and alkaline earth ions in the filtrate carbon filter 3 and increases the pH of the environment. This results in the settling vessel 4 to the additional release of suspended corrosion products and hardness salts, which are then displayed on the microfilters rough 6 and fine cleaning 7. Concentrate reverse osmosis filter 10, when saturated salts and radionuclides periodically withdrawn from the first intermediate tank 4 by cementing. MAU, when saturated with oil products and detergents, are extracted from the carbon filter 3 and fed to the combustion with solid combustible radioactive waste (paper, rags, cleaning materials, bad clothes) and the oil drained from the collection of petroleum products 2. Resulting ash has vodovyazushchimi properties and in the amount of 20-30% by weight of cement added to the Portland cement when cementing reverse osmosis concentrates.
In comparison with the known membrane-sorption methods of disposal of liquid radioactive waste with subsequent cementing concentrates in the proposed method polluting LRW petroleum products do not reduce the quality of the hardened cement compounds, and, ultimately, improve it, which is not obvious from the prior art. Thus,additive to Portland cement ash residue 20 to 30% by weight of cement increases the strength of cement stone in 1,5-2 times. In addition, the ash material contributes to the viscosity of the cement mixing and, consequently, reduce its porosity, i.e. improving the strength of the fixation of radionuclides.
Examples of specific performance.
Example 1. As LRW used drain water salinity (0.5 g/l) was determined by bicarbonates, sulphates and chlorides of alkali and alkaline earth metals (pH~7), contaminated with oil up to 50 mg/l, detergents (sulfone-scrap) up to 30 mg/l and suspended corrosion products, and silt up to 20 mg/liter Volumetric Σβ-activity LRW reached to 2.0×104Bq/l and was determined137Cs90Sr60Co.
The LRW decontamination was carried out as described above. As a download for a three-stage coal bulk filter used modified nitrogen-containing coals brand MAU-2A (manufactured by NPP "polichem"). In the microfilters coarse and fine cleaning of used items fiber grades EPV and all. In the reverse osmosis filter used roll of reverse osmosis membrane elements type ESPAI-4040. In a three-stage ion-exchange filter as load used cation marks KU-2 in the H+form.
Coal filters and microfilters stood no more than 5%90Sr, up to 15%137Cs and up to 50%60With. Reverse osmosis filters provided the coefficients of isdi from ∑β activity an average of about 100, i.e. at the level of desalination and ion-exchange filters - an average of more than 103. Thus, provided the total clearance from SR-radionuclides below the intervention level (cmwater) NRB-99/2009. When reaching into the reverse osmosis concentrate salt content up to 50 g/l was sent cementing. In coal filters after sorption on MAU 300 mg/d of petroleum products, radioactive waste coals were removed and sent for incineration together with the oil drained from the surface of the source container in the collection of oil, the volume of waste was reduced by several tens of times. The obtained ash was added to the Portland cement in the amount of 20-30% by weight of cement and was mixed Portland cement with reverse osmosis concentrate at a ratio equal to 1:1. Cured in 28 days cement compound satisfies the regulatory requirements of GOST R-2002 [radioactive Waste cemented. General technical requirements. - M., ed. standards, 2002, 8 S.].
Example 2. Differs from example 1 in that the content in LRW suspended corrosion products, and silt was 100 mg/L. In this case, the PA coal filters (curb MAU-2A) and the microfilters were allocated to 15%90Sr, up to 50%137Cs and up to 90%60With.
The proposed method can be implemented on the same domestic equipment, Thu is the prototype, i.e. industrially applicable. Depending on the type of contamination LRW for its removal can be used as all equipment installation, and only the necessary part.
Method of decontamination of liquid radioactive waste from nuclear power plants, oil contaminated with corrosion products and synthetic surface-active substances, in the field, including pretreatment on mechanical and membrane filters, desalination by reverse osmosis filters with the defense of liquid radioactive waste at the source and intermediate containers and purification on ion-exchange filters with curing the formed radioactive concentrates include Portland cement, characterized in that after settling of waste at the source capacity to produce discharge of the top layer of dirt in the collection of oil, when carrying out the pretreatment as mechanical filters use conventional filters with modified nitrogen-containing coals, after settling in the first intermediate capacity of liquid radioactive waste is served on membrane filters, which use microfilters coarse and fine cleaning, the waste is sent to the second intermediate tank, after settling in the second intermediate tank waste sent for Opatovicka the filters, the concentrate is returned to the first intermediate tank as alkalizing reagent prior to its saturation salts, saturated with petroleum coal extracted from the mechanical filter replace with new, and waste coals burn with the oil drained from the upper layer of the source containers in the collection of oils obtained ash include Portland cement together with saturated salts of reverse osmosis concentrate waste.
FIELD: power industry.
SUBSTANCE: method for preparation of spent nuclear fuel reprocessing solutions containing complexing agents for extraction of multivalent actinides at suppression of action of complexing agents consists in introduction to a solution of nitric-acid solutions of transient metals that fix complexing impurities better than plutonium does. As complexing agents, the solution can contain ethanedioic acid, mellitic acid and other polybasic acids and oxygen acids, DTPA and EDTA. As added binding agents, there used are nitric-acid solutions of molybdenum and/or zirconium, including spent nuclear fuel solution based on uranium-molybdenum alloys introduced in equimolar amounts or amounts close to them as to metal: complexing agent ratio.
EFFECT: invention allows extracting multivalent actinides from spent nuclear fuel solutions containing complexing agents applying non-destructive methods and without strong change of reagent medium.
FIELD: power engineering.
SUBSTANCE: calcination of a solution of radioactive wastes (RAW) is carried out in a microwave plasma reactor, then a homogeneous glass melt is produced in a frequency melter of direct induction heating. The method includes supply of the RAW solution into a zone of electrothermal processing, which comprises a zone of plasma microwave processing of the RAW solution in the water and vapour plasma and a zone of bath processing of the melt produced by direct induction heating of inorganic RAW ingredients, melting and electromagnetic mixing of inorganic RAW ingredients, continuous removal of the melt, cooling of the gas flow, cleaning of the gas flow from volatile products of RAW decomposition and from process dust. The device for realisation of the method comprises a plasma chamber, the upper part of which is made in the form of a truncated cone, equipped with an all-metal microwave plasmatron, which generates a flow of water and vapour plasma, a unit of RAW solution supply, a frequency melter of direct induction heating for melting and homogenisation of inorganic RAW ingredients, equipped with a pipeline for melt drainage, a collector - an accumulator of glass melt, a pipeline for gas flow transportation for cleaning.
EFFECT: solving the problem of complex environmentally and technical safe processing of RAW.
14 cl, 2 dwg
FIELD: power industry.
SUBSTANCE: invention refers to processing technology of high-salty liquid radioactive wastes of low and medium activity level, which contain up to 30% of organic substances by their being added to magnesite cement. Composite material has the following composition: loose dead-burned magnesite caustic powder - 27-28 wt %, hard salts - 5-6 wt %, calcium chloride (CaCl2) - 0.1-6 wt %, catalytic carbon-bearing additive - 0.1-0.2 wt %; potassium ferrocyanide solution - 0.05-0.1 wt %; and nickel nitrate solution - 0.05-0.1 wt %, and liquid radioactive wastes are the rest. The following sequence of ingredients is added to liquid radioactive wastes: hard salts, potassium ferrocyanide solution, nickel nitrate solution, calcium chloride, catalytic carbon-bearing additive, and loose dead-burned magnesite caustic powder. The invention allows obtaining compounds meeting the main requirements of their quality as per GOST R 51883-2002 (cesium leaching rate -137 ≤1-10-3, achieved - 2-10-5g/cm2·day, and compressive mechanical strength ≥5 MPa), with filling of dry radioactive layers of up to 37 wt %.
EFFECT: compliance with the main requirements.
FIELD: process engineering.
SUBSTANCE: invention relates to treatment of radioactive fluid and pulpy wastes formed in recovery of radiated nuclear fuel. Proposed method comprises destructing oxalate ions in mother waters by nitric acid in the presence of variable-valency metal ions. Processing of oxalate mother solution and pulpy wastes comprises mixing mother solution with solid phase of hydroxide pulp.
EFFECT: power savings, decreased amount of radioactive wastes.
3 cl, 3 tbl
FIELD: process engineering.
SUBSTANCE: installation for removal of liquid radioactive wastes (LRW) from temporary storage reservoirs comprises floating platform arranged there inside and composed of a tank equipped with system of ultrasound radiators connected with ultrasound oscillation generator and remote control system. Said ultrasound radiators are regularly arranged on floating platform walls and bottom to disperse and dissolve the sediments and to displace the platform in preset direction. Installation is equipped with LRW lifting and discharging system comprising pump and pipelined and remote control and observation system. Besides, said installation is integrated with LRS treatment unit.
EFFECT: higher efficiency and safety.
11 cl, 2 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to environmental protection against liquid radioactive wastes (LRW) that make byproducts of used nuclear fuel treatment or other industrial activities. Proposed method comprises converting LRW components into solid phase by processing them with silicon-bearing compounds of geothermal origin at 5-60°C. Dispersions of silicon dioxide spherulites are used as a hardener and produced by membrane concentration of natural geothermal solution, spherulite diameter making 4-150 nm at silicon dioxide concentration not lower than 105 g/kg, using microfibers from inorganic oxides, for example, basalt used in amounts of 0.5-5 wt % silicon dioxide dispersion weight.
EFFECT: higher safety.
4 dwg, 8 ex, 2 tbl
SUBSTANCE: disclosed is material which contains polyazacycloalkane which is grafted on polypropylene fibre, a method of producing said material and a method of removing metal cations from a liquid by bringing said liquid into contact with said material.
EFFECT: disclosed material combines excellent selectivity of binding heavy metals, lanthanides or actinides with excellent operational characteristics.
55 cl, 6 dwg, 9 tbl, 8 ex
SUBSTANCE: method of processing spent ion-exchange resins contaminated with radioactive elements involves wet grinding of resin grains to particle size 1-45 mcm, adding alkali to the obtained suspension to pH 10.5-11.0, liquid-phase oxidation of the suspension while feeding air into the oxidation zone under conditions of supercritical state of water at temperature 450-550°C and pressure 230-250 atm, removing gaseous oxidation products in form of CO2 and N2, separating the solid and liquid phases by filtering and subsequent deactivation of the liquid phase.
EFFECT: invention enables to reduce the volume of radioactive wastes for permanent storage, is characterised by absence of secondary gaseous wastes and does not require use of aggressive chemicals.
5 cl, 1 ex, 1 tbl
SUBSTANCE: method of processing a radioactive solution involves the following. First, an iron (III) compound in form of chloride or sulphate is added to the solution in amount of 0.04-0.05 mol/l to form an iron-containing precipitate. At the first step, a minimum amount of mineral acid - hydrochloric or sulphuric acid - is added, and at the second step 0.18-0.24 g-eq/l of the corresponding acid is added to the solution. The solution is held for not less than 120 hours at room temperature or not less than 18 hours at 70-95°C and sodium sulphide is added to the solution in a molar amount which is 1.5 times greater than the amount of the added iron (III) compound to form a basic collective precipitate of radionuclides of cobalt and caesium and a mother solution containing an organic complexing agent and a residual amount of radionuclides of cobalt and caesium. The mother solution is subjected to a post-treatment cycle by adding an iron (III) compound in amount of 0.02-0.04 mol/l with respect to iron (III) and mineral acid in an amount which is equivalent to content of sodium in the added sodium sulphide, holding the obtained mother solution and adding additional sodium sulphide in molar amount which is 1.5 times greater than the amount of the additionally added iron (III) to form an additional collective precipitate of the post-treated mother solution.
EFFECT: invention enables to increase processability of the method by replacing oxidation of the organic complexing agent with cationic substitution of the cobalt radionuclide therein, reduce the amount of reagents used while ensuring high degree of purification of solutions.
6 cl, 4 ex
FIELD: power industry.
SUBSTANCE: water treatment method of natural or artificial water reservoir from radioactive isotopes and harmful chemical substances involves the intake of source water, its pre-treatment and the main treatment by two-stage reverse osmosis so that filtrate is obtained, which is supplied to consumer as treated water and concentrate returned to water reservoir. Combined concentrate obtained at the stage of pre-treatment and the first stage of reverse osmosis is returned to water reservoir, and concentrate obtained at the second stage of reverse osmosis is supplied to the first stage of reverse osmosis.
EFFECT: invention allows improving the efficiency of treatment procedure and reducing the amount of secondary wastes.
6 cl, 1 dwg, 1 ex, 1 tbl
FIELD: chemical technology; recovery of deactivated and decontaminated radioactive industrial wastes.
SUBSTANCE: proposed method that can be used for deactivating and decontaminating industrial radioactive wastes incorporating Tb-232 and their daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Sl, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like includes dissolution of wastes, treatment of solutions or pulps with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9 - 10 in the amount of 120-150% of total content of metal oxyhydrates stoichiometrically required for precipitation, pulp is filtered, and barium chloride in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp, as well as pre-diluted sulfuric acid spent 5 - 20 times in chlorine compressors in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2 are introduced in filtrate. Alternately introduced in sulfate pulp formed in the process are lime milk to pH = 11 - 12, then acid chloride wash effluents from equipment and industrial flats at pulp-to-effluents ratio of 1 : (2 - 3) to pH = 6.5 - 8.5, and pulp obtained is filtered. Decontaminated solution is discharged to sewerage system and sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization process; then 35 - 45 mass percent of inert filler, 10 - 20 mass percent of magnesium oxide, and 15 -m 25 mass percent of magnesium chloride are introduced in pasty mixture formed in the process while continuously stirring ingredients. Compound obtained is subjected to heat treatment at temperature of 80 - 120 oC and compressed by applying pressure of 60 to 80 at.
EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes due to enhanced coprecipitation of natural radionuclides.
7 c, 1 ex
FIELD: recovery of liquid radioactive wastes.
SUBSTANCE: method for extracting nitric acid from solution includes bringing solution in contact with nitrogen-containing agent and separating the phases. For the process use is made of organic nitrogen-containing material forming poorly soluble sediment together with nitric acid. Urea nitrate sediment deactivating method includes treatment of inert nozzle in fluidized bed at temperature of 750 - 800 °C with fuel combustion products having residual oxygen content of 2 - 3 volume percent.
EFFECT: reduced cost.
7 cl, 5 ex
FIELD: radioactive waste treatment.
SUBSTANCE: suspension of magnetite obtained via electroerosion dispersing of iron-containing raw material in distilled water is added to solution to be processed. Adjusting pH of solution to 11-12 leads to precipitation. Decanted solution is subjected to magnetic separation followed by ion-exchange purification.
EFFECT: enhanced purification efficiency.
3 cl, 1 tbl
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.
FIELD: recovery of radioactive wastes.
SUBSTANCE: proposed method for matrix immobilization of industrial wastes includes preparation of source solution of industrial wastes and impregnation of ceramic matrix with this solution followed by roasting this matrix; source liquid radioactive wastes used for the purpose are first treated with promoter crystallization solution doped with oxide-forming admixtures whereupon radioactive wastes are introduced in ceramic matrix and roasted using microwave energy at temperature of 900 - 1 000 °C. Such procedure provides for recovering great amount of radioactive wastes included and chemically bonded in ceramic matrix which makes it possible to reduce leaching and to enhance matrix strength and life.
EFFECT: facilitated procedure, reduced cost, enhanced quality of radioactive waste immobilization and environmental friendliness.
FIELD: technology of handling of the liquid nuclear wastes of the nuclear fuel and power cycle; methods of reprocessing of the liquid nuclear wastes.
SUBSTANCE: the invention is pertaining to the procedure of the liquid nuclear wastes handling of the nuclear fuel and power cycle and may be used during reprocessing of the liquid nuclear wastes (LNW). The method includes the preliminary concentration, ozonization, microfiltration of the vat residue with fractionation of the permeate and the concentrate and the ion-selective purification of the permeate using the ion-selective a sorbent. At that the microfiltration is conducted at least in two stages: the permeate of each previous stage of the microfiltration is directed to the microfiltration as the source solution for the subsequent stage of the microfiltration, and at the final stage of the permeate from the microfiltration is sent to the utilization. The concentrate produced at each next stage of the microfiltration is mixed with the source solution of the previous stage of the microfiltration. The concentrate produced at the first stage of the microfiltration is directed to the conditioning and dumping. The ion-selective sorbent is added in the permeate of the previous stage of the microfiltration before the final stage of the microfiltration. The invention ensures: reduction of the volume of the liquid nuclear wastes due to the deep purification of the LNW with the high saline share from the radionuclides and extraction of the radionuclides in the compact form of the sparingly soluble compounds at the corresponding increase of the factor of purification of the salts extracted at the stage of the vat residue treatment; reduction and optimization of the consumption of the permeate and concentrate interacting with the source solution as well as produced at the further stages.
EFFECT: the invention ensures: reduction of the volume of the liquid nuclear wastes; the deep purification of the LNW with the high saline share from the radionuclides and extraction of the radionuclides in the compact form of the sparingly soluble compounds at the corresponding increase of the factor of purification of the salts extracted at the stage of the vat resudue treatment; reduction and optimization of the consumption of the permeate and concentrate interacting with the source solution ands produced at the further stages.
FIELD: environment protection against radioactive pollutants; immobilization of nuclear radioactive wastes.
SUBSTANCE: proposed method for solidifying liquid radioactive wastes includes their spray drying and calcination, calcination product vitrification using flux dopes, melt draining to tank, and annealing of solid block. Liquid radioactive wastes are heated in advance in continuous flow to evaporate 30-80 percentage ratio of water contained in them, and steam-water mixture produced in the process is sprayed under its own pressure in chamber heated to temperature of 600-800 °C. Solid particles of calcination product are separated from steam-gas mixture by sedimentation at temperature below 300 °C and filtration.
EFFECT: extended service life of equipment, enhanced productivity and radiation safety for personnel handling highly radioactive products.
FIELD: nuclear engineering; preservation of dry, wet, and liquid radioactive wastes.
SUBSTANCE: proposed composition has resin portion of cold-cured compound ATOMIK and filler. Resin portion ingredients are as follows, parts by weight: epoxy oligomer, 100;, curing agent (aromatic amines), 38-50 furfural, 9-11. Used as filler is composition incorporating following ingredients, parts by weight: cement, 50-100; marshalite, 50-100 or bentonite, 50-100, or when they are jointly used: marshalite, 90-100 and bentonite, 90-100. Such composition provides for desired radiation resistance in absence of leaching of alpha-, beta-, and gamma-active radionuclides from preserved specimens of reactor graphite.
EFFECT: enhanced radiation stability of preserved specimens free from pits and voids, and adequate lifetime of preserved wastes; ability of their depreservation.
1 cl, 2 dwg, 2 tbl, 2 ex
FIELD: treatment of radioactive effluents and solid-phase saturated waters.
SUBSTANCE: some portion of organic fraction is reduced in first reactor by way of biological aerobic treatment. Filtrate/permeate taken from tangential filtering device is either directly used or supplied to first or next reactor. Solid phase is gravitationally extracted within tank of partial-flow filtering device and compacted in bottom region; concentrated effluents flowing from tangential filtering device are fed in next sedimentation region which is above first sedimentation region or above next one through intake channel; then effluents flowing above or from one side of sedimentation region are discharged through branch channel.
EFFECT: ability of selecting and technically optimizing separate modules.
34 cl, 5 dwg
FIELD: recovery of irradiated nuclear fuel.
SUBSTANCE: proposed method for reconditioning reusable extractant includes treatment of the latter with aqueous alkali solution. Extractant containing uranium in amount of minimum 5 g/l is treated with alkali solution whose concentration is over 10 mole/l followed by sediment separation.
EFFECT: reduced radionuclide content of reusable extractant including difficult-to-remove radioactive ruthenium.
5 cl, 2 tbl, 2 ex