Microbiological method of transmutation of chemical elements and conversion of isotopes of chemical elements
SUBSTANCE: radioactive raw materials containing radioactive chemical elements or their isotopes, are treated with an aqueous suspension of bacteria of Thiobacillus in the presence of elements with variable valence. The radioactive raw materials are used as ores or radioactive wastes of nuclear cycles. The method is implemented to obtain polonium, radon, francium, radium, actinium, thorium, protactinium, uranium, neptunium, americium, nickel, manganese, bromine, hafnium, ytterbium, mercury, gold, platinum, and their isotopes.
EFFECT: invention enables to obtain valuable radioactive elements, to carry out the inactivation of nuclear wastes with the conversion of radioactive isotopes of the waste elements into stable isotopes.
3 cl, 18 dwg, 5 tbl, 9 ex
SUBSTANCE: what is provided is heterogenic catalytic decomposition of process media containing oxalate ions having the concentration of 16-18 g/l (complexing agents (up to 2 g/l), surfactant (up to 50 mg/l)) and nitric acid (up to 60 g/l) on a platinum catalyst applied on anion exchange resin VP-1AP (0.05-2 wt % of platinum). The effect is achieving a degree of decomposition of oxalate ions, complexing agents, surfactants up to 99.9%, in the residual concentrations - less than 10 mg/l in oxalate ions and less than 1 mg/l in complexing agent (EDTA, Trilon B) and surfactant (sulphonol).
EFFECT: improving the characteristics.
3 cl, 1 dwg
FIELD: physics, nuclear.
SUBSTANCE: offered group of the inventions relates to the devices for processing of radioactive solutions. In the offered method of processing of radioactive solutions before filling of the vessel with the solution in its bottom place an additional vessel from a thin dielectric film is placed. Then the radioactive solution is poured into the vessel, with adding of the substances for treatment process control. After that the solution is exposed to irradiation by unipolar electromagnetic impulses with the power more than 1 MW and with duration less than 1 ns, minimum frequency 1 kHz. The solution is treated within 10-30 minutes, held in the vessel during 1-4 days, then the treated solution is drained and additional vessel is removed for utilization. The offered unit contains a current-conducting housing (1), the central part of which contains electrode (2), designed as a horizontal plate. The plate repeats the housing cross-section shape, but have the sizes 20-30% from the cross-section area of the housing. The unit also contains the generator of unipolar electromagnetic impulses, located outside the housing (3). During the treatment at the bottom of the housing the additional vessel (4) is placed.
EFFECT: simplification of devices for treatment of radioactive solutions with keeping of high quality of cleaning.
2 cl, 1 dwg
SUBSTANCE: proposed method comprises immersion of alloy into salt melt to change rare-earth element from liquid alloy into melt by oxidation. Note here that said oxidation us performed in zinc chloride melt at 420-550°C while melt zinc ions are used as oxidiser.
EFFECT: higher yield.
2 tbl, 2 ex
SUBSTANCE: invention relates to radiochemical technology and can be used in production of "reactor" 99Mo as a generator of 99mTc of a biomedical purpose, as well as in an analysis of technological solutions for preliminary separation of Mo or Mo and Zr in extraction reprocessing of solutions of technology of spent nuclear fuel of nuclear power plants (NPP SNF). Described are versions of methods of selective extractive separation of a considerable part of molybdenum or together molybdenum and zirconium from radioactive solutions with obtaining an extract. A reprocessed radioactive solution is processed with an extractant, which represents poorly soluble in a water phase alcohol, in the presence of an extracted complexing agent. As the complexing agent, hydroxamic acids with a number of carbon atoms 6-12 can be used, which ensures sufficiently complete extraction of molybdenum and zirconium in an organic phase. Molybdenum or molybdenum and zirconium are separated from the extract in the compact form by sublimation or re-extraction.
EFFECT: obtaining the extract, purified from alpha- and gamma-radioactive admixtures more than by 100 times, and further separate extraction of radionuclides from the extract, combined in the final stage of the process with the extractant regeneration.
17 cl, 2 tbl, 12 ex
SUBSTANCE: method involves converting wastes to a gel-like state and is characterised by that solutions of highly active wastes are mixed with zirconium and iron salts and glycerine to concentration of said salts of not less than 0.12, 0.6 and 0.25 M/l respectively, holding the obtained mixture for not less than 2.5 hours, followed by adding to the mixture a solution of mono-substituted potassium phosphate in phosphoric acid to molar ratio of components Zr:Fe:K:PO4=1:3:2:5-8, drying, calcining the obtained polymer gel of zirconyl phosphate at 70-90°C and 300-400°C, respectively, and melting the obtained granules at 980-1000°C.
EFFECT: converting wastes into compact material which is suitable for long-term and safe storage.
3 cl, 2 tbl, 1 ex
SUBSTANCE: invention relates to hydrometallurgy of uranium and can be used to recycle mother solutions formed when producing uranium tetrafluoride from nitrate solutions via extraction, re-extraction and heat treatment of uranium compounds obtained from re-extracts to obtain uranium dioxide and further treatment thereof with chloride and fluoride solutions. The method of recycling mother solutions from production of uranium tetrafluoride involves mixing said solutions at pH 4.0-5.2 by bubbling air until pH stabilises and treating with sodium hydroxide at pH 10.5-11.0, separating the uranium-containing residues from the solutions and return thereof to the step of leaching raw products, settling the waste solutions in a tailing pond and pumping the remaining part of the solutions into the ground.
EFFECT: low consumption of nitric acid, sodium hydroxide and lime, reduced discharge of liquid wastes in the tailing pond.
3 cl, 6 tbl
FIELD: process engineering.
SUBSTANCE: invention relates to processing of heterogeneous liquid radioactive wastes, particularly, to processing of used fine abrasive filter materials and can be used for processing of waste filter perlite powder of special water treatment systems. Proposed method consists in extraction of filter perlite powder pump from storage tank, removal of excess moisture, transfer by hydrotransport, cementation, and adding ion exchange resins in amount of 10÷75% of filter perlite powder volume at density of 1÷1.5 g/cm3 to said pulp before transfer from storage tank.
EFFECT: 80-100 times decreased wear of equipment and pipelines.
SUBSTANCE: invention relates to processing liquid radioactive wastes formed when processing spent nuclear fuel. Described is a method of processing technetium solutions, which involves precipitation of technetium from nitrate solutions with concentration of nitric acid or the nitrate ion of not more than 3 mol/l, with concentrated aqueous solutions of o-phenanthroline or α-bipyridyl complexes of divalent transition metals, or mixed complexes of said organic compounds or mixed complexes containing o-phenanthroline or α-bipyridyl with dibasic amines. The obtained precipitates of organometallic pertechnetates are calcined in a hydrogen current at temperature of 600-1200°C with or without a low-melting metal or oxide thereof with melting point of 200-800°C to obtain stable matrices that are suitable for further storage and processing.
EFFECT: obtaining technetium in the final form which is suitable for further storage and processing.
5 cl, 2 tbl, 6 ex
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.
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.
SUBSTANCE: invention relates to rare and radioactive element technologies and can be used to obtain concentrates of rare and rare-earth elements from monazite. The method of processing monazite concentrate includes treating the feed stock with a mixture of sulphuric acid and ammonium fluoride at 200-230°C for 30-40 min, purifying the obtained product from phosphate and fluoride products by sublimation, water leaching sulphates of rare-earth elements, neutralising the solution with barium chloride, selectively separating the thorium, uranium, iron and rare-earth product, wherein separation of the rare-earth product is carried out through a step of precipitating double salts of rare-earth elements with ammonium sulphate, followed by conversion into nitrates of rare-earth elements through a calcination step, dissolving in nitric acid and solvent refining from thorium impurities.
EFFECT: invention provides high degree of extraction and purity of the rare-earth product.
3 cl, 2 dwg, 3 ex
SUBSTANCE: proposed method comprises leaching the stock nitric acid solution to obtain suspension, introducing coprecipitator therein at 30-50°C and mixing. Then, clarified solution is separated from insoluble residue and directed for extraction. Said coprecipitator represents fresh solution of copolymer of acrylamide and chloride trimethyl ammonium ethyl acrylate of molecular weight of 3-15 millions with low charge density. Copolymer is introduced to concentration of 5.95-11.9 mg/l of insoluble residue. Prior to separation of clarified solution from insoluble residue settling is performed for 30-40 minutes.
EFFECT: lower processing costs.
3 cl, 1 dwg, 1 tbl
SUBSTANCE: composition contains a compound of formula (I)
as a complexing component, where R is a C1-C12 alkyl, in percentage content of 1-99%, and the rest of the polymer matrix is a macroporous spherical granular copolymer of styrene with divinyl benzene LPS-500 with granule size of 40-200 mcm.
EFFECT: high sorption capacity with respect to Mo-99.
SUBSTANCE: invention refers to metallurgy, particularly to hydrometallurgical methods of processing and deactivation of radioactive waste at rare metal production. The method includes hydro washing away of spent melt of saline spraying filter (SSF), the chlorination process of loparit concentrates, treatment of produced suspension with alkaline reagent, mixing with iron containing shop flush waters, separation of radioactive sediment from the mother solution and transporting of radioactive sediment into a special waste storage (SWS). Prior to treatment with the alkaline reagent the suspension, produced after hydro washing away of spent melt SSF, is mixed at a ratio 1:(0.8-1.2) with the solution, containing 250-300 g/dm3 chlorides of alkali metals, and is heated to 85±5°C. With the use of solution of sodium hydroxide as the alkaline reagent treatment of the suspension is performed to pH 2.0+0.5, then this solution is held for 0.5+0.1 hr, then solution of high molecular flocculant- hydrolysed oilacrilamid - is introduced and is held without mixing for 2.0±0.5 hrs. After that the thickened part of the suspension is fed to a nutsch-filter, the produced sediment - rare metal concentrate - is dried, tempered and transfered to chlorination of source loparit concentrates. Filtrate is combined with clarified portion of the suspension, heated to 80±10°C and treated with solution of sodium hydroxide to pH 12.0±0.5. Produced oxihydrate pulp is held at 80±10°C for 1.0±0.5 hrs and is fed to a filter-press-I; the extracted radioactive sediment is washed out at the filter-press-I 3-4 volumes of water, and process water is merged with shop flush water. The washed out sediment is blown out with a compressed air at the filter-press-I, then unloaded and transported to SWS, while mother solution is mixed at a ratio of 1:(10-20) with iron containing shop flush water. Produced radioactive chloride solution is heated to 80±10°C and treated with solution of sodium hydroxide to pH 12.0±0.5, the resulted pulp is held at 80±10°C and pumped to a filter-press-II with production of deactivating solution, which is discharged to a shop drainage, and with production of sediment; the latter is merged with the sediment - rare metal concentrate, extracted out of suspension after dissolving of the spent melt SSF; the said sediment is heat treated and partially neutralized, then dried, tempered and transferred to chlorinating in saline chlorinators together with the source loparit concentrate.
EFFECT: upgraded degree of deactivation of solutions and discharge waters and additional extraction of valuable elements.
2 dwg, 1 ex
FIELD: radiochemistry; analytical chemistry.
SUBSTANCE: proposed method consists in treatment of solution containing elements to be separated, diethylene triamine, pentaacetic acid, carbamide or formic acid, extracting agent in form of solution of chlorinated cobalt dicarbollide and polyethylene glycol in organic solvent or solution of cobalt dicarbollide, zirconium slat of dibutyl phosphoric acid and polyethylene glycol in organic solvent. Americian passes into organic solution at higher degree as compared with curium. Proposed method takes into account factor of separation of americian and curium and facilitates the process due to avoidance of salting-out agent.
EFFECT: enhanced efficiency.
4 cl, 2 tbl, 2 ex
FIELD: reprocessing of worked-out equipment, contaminated with radioactive impurities.
SUBSTANCE: claimed method includes deactivation of contaminated equipment in assembly, disassembling, fragmentation, separation of surface-contaminated fragments, deactivation thereof, classification of metal kinds and groups, and acceptance of mechanical and physical alterations. Fragments satisfied to acceptance results are deactivated without changing form and metal structure thereof and separated into fragments for direct application and for technological update. Fragments not satisfied to acceptance results are used as debris of metal radwastes in metallurgy to produce steel and alloys. Method for production of steel and alloys includes batch preparing, additive introducing during melting process and casting of finished metal. Necessary debris amount to produce desired chemical element content in specific grade of steel or alloy is predetermined followed by calculation of dilution coefficient and upper limit value of debris specific activity. Then debris with specific activity of not more than calculated upper limit value is fed in founding as the base metal and/or addition alloy.
EFFECT: simplified and economy reprocessing method; increased metal amount recycled into national economy, and reduced solid radwaste amount.
3 cl, 2 ex
SUBSTANCE: method includes controlling flow of air fed for biooxidation and the rate of mixing in a tub where biooxidation is carried out, based on concentration of divalent iron ions in a pulp, while ensuring a near zero concentration value. When the concentration of divalent iron ions in the pulp increases to more than 0.5-1.0 g/dm3, the flow of air fed for biooxidation and the rate of mixing are increased. In the absence of divalent iron ions in the pulp, the flow of air fed for biooxidation and the rate of mixing are reduced until traces of divalent iron ions appear to a near zero concentration.
EFFECT: simple, accurate and fast control of the process of biooxidation of sulphide concentrates, high redox potential and efficiency of biooxidation of sulphide concentrates, low power consumption of biooxidation.