The method of fixation of radioactive waste
(57) Abstract:The invention relates to nuclear energy, in particular to methods of radioactive waste management (RW), located in the basins of storage in the form of aqueous solutions and suspensions of sediment. Sediments contain radionuclides by several orders of magnitude greater than the aqueous phase of the basin-store. Sediments are characterized by high mobility, can easily vspuchivatsya, to flow and to be extruded at the conservation pools of storage by filling. The main technical challenge in conservation pools stores is reliable fixation sediment RAO on the bottom of the reservoir by filling them without mixing with vodolazam not less than 2 slag, which is then ground to a specific surface 4000-6000 cm2/, the Height of the slag backfill shall be not less than 2.5 cm, and the speed of filling of 0.125-0,375 m2/H. This method allows you to get a secure fit RAO on the bottom of the pool store, their subsequent curing and robust composite, ensuring their safe disposal. 1 C.p. f-crystals, 2 tab. The invention relates to the field of nuclear energy, in particular to Stadnyk solutions and suspensions of sediment.Sediments contain radionuclides by several orders of magnitude greater than the aqueous phase of the basin-store. Consisting mainly of colloidal phases hydroxides of Fe+3and Al+3sediments are characterized by high mobility, can easily vspuchivatsya, to flow and to be extruded at the conservation pools of storage by filling. The output of bottom sediments on the water or on the shore, due to the mixing or extrusion, is dangerous as a source of possible emergency windscreen separation of radionuclides, because the power (height) of bottom sediments increases as a result of their displacement during filling of waters of the pool store.Known technology fixation sediment RAO at the conservation pool storage by filling rocky soil with the use of hollow concrete blocks /1/.The disadvantages of this method include the lack of binding properties of the backfill material, which does not allow to reliably fix RAO on the bottom of the pool store.Also known a technology of filling the waters of the basin-store by horizontal slipped on easily rock soil from the shore to the centre of the pond /2/. The main disadvantage of this method t is I.The closest technical solution to the present invention is a method of curing waste containing radioactive isotopes, by mixing with steel granulated slag with vodolazam respect of 0.2 - 0.6 with a specific surface area binder 2800 - 4000 cm2/g /3/ prototype.The disadvantages of the method prototype should include mandatory mixing of the slag after filling in waste and solidification at low vodolazam respect of 0.2 to 0.6, which is not possible in the case of sediment RAO to ensure a secure fit on the bottom of the pool store.In this regard, the main technical challenge in the conservation of basin-RW repositories is a reliable fixation of sediment RAO at the bottom by filling them without mixing metallurgical slag, followed by curing and robust composite, ensuring safe disposal of radioactive waste.This new technical result is achieved in that in the method of fixation of radioactive waste by filling and curing of metallurgical slag backfill produced without mixing with vodolazam not less than 2 slag, which is then ground to a specific item is delivered 0,125 - 0,375 m2/PMA significant difference in the specific weights of metallurgical slag (d=a 3.2-3.4 g/cm3and sediment RAO (d~1,2-1,3 g/cm3) causes the penetration of the slag particles in the depth of the colloidal phase sediment, causing lifting and squeezing the last filling.The degree of extrusion of bottom sediments, which is defined as the ratio of the number of bottom sediments above the slag backfill the remaining beneath it depends on the speed of filling slag (m2/h), height (cm) and should not exceed 0.1.For metallurgical slag with a specific surface area of 4000 - 6000 cm2/g degree of extrusion sediment RAO at a speed of slag backfill 0,125 - 0,375 m2/h does not exceed 0.1. The increase in the rate of slag backfill up to 0.45 m2/h causing the rise of sediment RAO and increase the extent of their bump to 0.12 to 0.15 for both primary and sour metallurgical slag.At the height of the slag backfill less than 2.5 cm (specific surface area of from 4000 to 6500 cm2/g), as and when the specific surface area of 3500 cm2/h (the height of the backfill 2.5 cm) effect of solidification absent in both types of toxins under the water phase at a depth of 1 m during the year. Vaem. Due to the fact that over the bottom sediments RAO is always a layer of the aqueous phase depth of 1 m, vodovorote ratio is at least 2. The strength of the monoliths when you commit sediment RAO slag backfill exceeds one year 270 kgf/cm2. The increase in specific surface metallurgical slag up to 6500 cm2/g does not change the parameters of strength, but is not economically advisable.Examples of implementation
Example 1. Metallurgical slag (acidic or basic) is crushed to obtain a specific surface area of 3500 - 6500 cm2/'clock In the aqueous phase pool storage depth of 1 m is poured out without mixing the slag with a specific surface area of 3500, 4000, 6000 and 6500 cm2/g, creating a height of backfill 1,0; 2,5 and 30 cm and maintained during the year. As the aqueous phase of the basin-store use distilled water (similar rainfall) or salt solution containing NaNO3, PA2SO4, Na2Ac, NaCl, Mq+2Ca+2at pH of 8.9-9.0 and the amount of salt 80 g/L.The test results of samples of the slag backfill strength after one year of exposure in the aqueous phase are presented in table. 1.From the data presented in table. 1, it follows that when the height of the slag backfill less than 2.5 and not harden. Similar results in reduction of the specific surface of the slag from 4000 to 3500 cm2/g at a height of backfill 2,5 seeThe increase in the specific surface of the slag from 6000 to 6500 cm2/g does not change the parameters of strength, but uneconomical. Metallurgical slag with a specific surface area of 4000 - 6000 cm2/g hardened to a depth of 1 m at vodolazam not less than 2 in water and water-salt solutions at the height of the backfill is not less than 2.5 cm, forming one year composite, the strength of which exceeds 300 kgf/cm2.Example 2. Metallurgical slag (acidic or basic) is crushed to obtain a specific surface area of 4000 - 6000 cm2/year In the aqueous phase of the basin-store, containing at a depth of 1 m sediment RAO, pour out without mixing the slag (specific surface area of 4000, 6000 cm2/g) with a speed of filling 0,125; 0,375; 0.45 m2/h, creating a height of backfill 2,5; 6; 15; 30; 34 cm and fixing the degree of extrusion of sediment.As the simulator sediment RAO basin-store use a suspension of hydroxides of iron and aluminium, taken in the ratio of Fe+3:Al+3=1:1 with a concentration of 13.3 g/l in a solution of NaNO3(70 g/l) at pH 9-10. The results of the COI is dstanley in table. 2.From the data table. 2 it follows that when the speed of filling 0,125 - 0,375 m2/h for metallurgical slag with a specific surface area of 4000 - 6000 cm2/g degree of extrusion sediment RAO does not exceed 0.1 at the height of the backfill is not less than 2.5 see an increase in the speed of the slag backfill up to 0.45 m2/h causing the rise of sediment RAO and increase the extent of their bump to 0.12 to 0.15 for both primary and sour metallurgical slag.Metallurgical slag acidic and basic with a specific surface area of 4000 - 6000 cm2/g covered without stirring speed 0,125 - 0,375 m2/h, and the height of the slag backfill of at least 2.5 cm begin to solidify when vodolazam more 2 through 140 - 110 and 12 days, respectively. A year later the strength of the slag monoliths commit sediment RAO is more than 270 kgf/cm2.Thus, the use of the proposed method will allow you to get a secure fit of the bottom sediments of radioactive wastes resulting from the curing that will ensure the safety of their burial in water basins stores.Sources of information
1. Y. C. Glagoleva, E., zekun and other Strategy for radioactive waste is alexahin, C. A. Egorov. Retrospective recovery of morphometric parameters oz. Karachay using geographic information systems. The issues of radiation safety, N 4, 1996, S. 60 - 66, the Magazine "Mayak", the Ministry of atomic energy.3. Auth. testimony N 880149, publ. 30.04.82. Newsletter # 16 (prototype). 1. The method of fixation of radioactive waste by filling and curing of metallurgical slag, characterized in that the filling is produced without mixing with vodolazam not less than 2, and metallurgical slag is then ground to a specific surface area of 4000 - 6000 cm2/g, and the height of the slag backfill shall be not less than 2.5 cm, and the speed of filling of 0.125 - 0,375 m2/PM2. The method according to p. 1, characterized in that used as the acidic and basic metallurgical slag, with astringent properties in water, aqueous salt solutions and suspensions.
FIELD: monitoring the ecological safety.
SUBSTANCE: it is proposed a new method for monitoring the safety of sites for storage of radioactive wastes. The method is based on determination of the Cr(VI) nonsorbed ion concentration in the soils, surrounding the storage sites.
EFFECT: reliability of monitoring the safety of sites for radioactive waste storage.
4 cl, 4 dwg, 3 ex, 2 tbl
FIELD: evacuation of radioactive wastes.
SUBSTANCE: proposed method for container-free subsurface burial of solid radioactive wastes in abandoned deep workings of cryolite zone involves delivery of solid radiation sources pre-cooled in winter to abandoned mine workings. Radiation sources are placed in layer-by-layer manner on prepared falsework paled floor, leveled, compacted, flooded with water, and frozen by natural cold before piling radioactive wastes to full height of subsurface workings. In the process, burial ground is shaped in the form of pillar. Split ice is added in the course of placing layers of solid radioactive wastes including their forced cooling with cold atmospheric air.
EFFECT: enhanced reliability and safety.
1 cl, 1 dwg
FIELD: disposal of radioactive wastes.
SUBSTANCE: proposed method for building radioactive waste disposal structure involves formation of horizontal helical system of round-section transport and room tunnels penetrated by single mechanized tunneling machine including erection of grade-crossing elimination structures. Helical system of tunnels is made in the form of ellipse with variable distance between adjacent tunnels of helical system. Grade-crossing elimination structures are erected at two diametrically opposite points of system where each pair of tunnels is joined to form single tunnel communicating with adjacent coupled tunnel through crossover. Tunnel-to-tunnel distance is predetermined at several points by simulation including heat and radiation load on soil mass.
EFFECT: enhanced radiation safety and reduced construction charges.
1 cl, 2 dwg
FIELD: methods of the radioactive waste disposal.
SUBSTANCE: the invention is pertaining to the field of the radioactive waste disposal. Substance of the invention: the method of the radioactive waste disposal includes boring of a borehole, placement of containers with the A-waste and leaving of a barrier pillar in the zone of the plastic deformations of the surrounding rocks, filling of the free volume of the borehole with an expanding plugging material and sealing of a the borehole head. At that the A-waste disposal is conducted in a clay bed, which is in a plastic state. The containers with the A-waste are placed in the middle part of the clay bed in its section with a length of l = m -2hδ, where "m" is the clay bed thickness, hδ is the thickness of argillaceous rocks. The plugging of the free volume of the borehole is conducted using the extracted from the borehole dried and crushed rock. At that on the section of placement of the containers the plugging is performed by substitution of the drilling mud, and on the section of the barrier pillar after an evacuation of the drilling mud - by portioned feed with water addition in the volume corresponding to the natural humidity. Advantages of the invention consist in an increased degree of reliability at the radioactive waste land disposal.
EFFECT: the invention ensures an increased degree of reliability at the radioactive waste land disposal.
5 dwg, 1 ex
FIELD: long-term storage of radioactive wastes.
SUBSTANCE: spent nuclear fuel storage has vertical well with bridge in top part of well, containers with spent nuclear fuel boxes disposed in well, and well ventilating system. Containers are made in the form of cylinders with perforated sections in bottom part which are vertically installed on well face. Boxes holding spent nuclear fuel are disposed within container one on top of other. At least one empty container is placed in well and bridge is installed in top part of well below upper ends of containers.
EFFECT: enhanced reliability and long time of radioactive wastes isolation.
2 cl, 2 dwg
FIELD: burying liquid radioactive wastes; waste recovery at radiochemical plants.
SUBSTANCE: proposed method for burying liquid radioactive wastes incorporating hydrolyzing admixtures into deep-seated container bed includes correction of waste pH by nitric acid solutions and pre-treatment of container bed by forcing nitric acid solutions therein. Nitric acid solution is introduced into container bed in amount sufficient for neutralizing carbonates contained in soil which enters in reaction with waste and for attaining void liquid pH of 1.5, as well as into wastes until their pH is brought to 1 - 1.5. Under such conditions wastes are passed into deep-seated formations without precipitating over long distances.
EFFECT: elongated working time of well, enhanced safety of burying wastes into deep-seated beds.
1 cl, 3 ex, 3 tbl
FIELD: physics; construction.
SUBSTANCE: process of crashed atomic reactor entombment includes construction of underground mortuary in the form of vertical underground excavation. Internal volume of the excavation is filled with ice which forms a new temporary ice foundation under the basis of the crashed reactor. The weight of the latter is shifted to the new ice foundation, heat is conducted to it, and gradually the height of ice foundation is decreasing till the complete removal of ice. At that, the crashed reactor is set at the mortuary made previously at the basement of excavation. Before deposition of the crashed reactor underground, solidity (thickness) of frozen soil body under the reactor basis is improved, and then, after the new ice foundation is ready, the load is increased, and the previous ground base is destroyed by adjoining of excavation ice body to the crashed reactor basis via flexible load-bearing cables laid through the vertical wells.
EFFECT: reduces amount of work in immediate proximity to a crashed atomic reactor.
FIELD: underground disposal of biologically hazardous sewage.
SUBSTANCE: process of underground disposal of biologically hazardous sewage into geological formations, which do not have distinct aquifiers above the working floor, includes drilling of injection wells and pumping sewage into the working floor. The process is distinguished by sewage pumping into working floor simultaneously with technical fluid injection into a stratum above the working floor. Pressure of technical fluid injection into the buffering floor is sustained at the level of 0.9-1.1 of sewage injection pressure in the working floor.
EFFECT: prevents disposed sewage penetration into higher aquifiers.
2 cl, 2 dwg
FIELD: construction, hydrotechnics.
SUBSTANCE: invention is attributed to cleaning methods for beds of minor rivers in permafrost zone with seasonal flow from sediments contaminated with radionuclides from radioactive solid waste handling. Removal of contaminated sediments is executed in winter by segments in downstream direction after discharge cancellation and their dewatering. Bottom ground is loosened and mechanically shaved by layers as it is freezed by natural cold with stocking it in temporary piles and subsequent transportation outside river floodplain for burying or laying in surface burial hills. To speed-up layer-by-layer freezing the net of trenches with vertical walls is cut in parallel in bottom ground depth as it freezes. Trench width is defined by parameters of equipment being used, their depth is not less than half a meter and distance between trenches corresponds to double trench depth. The invention allows to isolate from biota (for a period of not less than 100 years) the most migration suspectable solid radioactive wastes and hence to lower the risk of people irradiation.
EFFECT: lowering the risk of people irradiation.
SUBSTANCE: invention can be used for protection of fresh groundwater, ground and soils from pollution by toxic and radioactive substances in areas of technical wastes storage. In expected place of landfill it is created barrier, formed samples set of ground strata for depth till first water-bearing stratum of protected territory and set of local clay samples from the nearest region. Samples of ground strata are divided into layers presented by different lithological members and then territory is divided into separated sections and for each of them functioning critical time as natural geochemical barrier is defined. Then territorial sections (k) are defined, for them variation range ΔTs of territory required operation life Toper from critical time of its operating as natural geochemical barrier Tscrit exceed previously agreed acceptable value ΔTs= Toper - Tscrit > Tacc. Then it is formed database of potential contaminant migratory parameters for local clays and materials for artificial barriers, each section of being protected territory is covered by barrier material.
EFFECT: providing criterion of predictability territory operation critical time, appraisal ability of contaminants migration velocity in ground strata and increasing of being protected territory operating time.
7 cl, 2 dwg