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IPC classes for russian patent Method of cleaning soil contaminated with strontium radionuclide (RU 2504852):
Another patents in same IPC classes:
 Cutting machine of caissons with defective irradiated fuel assemblies / 2504851
Objective of the proposed technical solution of the device is creation of a special machine for cutting of a hole of large diameter in a thick-wall tube sheet around the caisson using technological machining methods under conditions of high embedded depth and narrowness of a cutout. The machine is equipped with a cutting tool rotation and vertical supply mechanism, as well as a moving platform. The machine is equipped with a horizontal supply mechanism and installed on guide posts arranged on the moving platform. A fixed support of the machine, at the end of which there is a conical cavity made coaxially to rotation axis of the cutting tool and into which a semi-spherical projection of a centring head, in the centre of which there is a blind hole, is installed on the caisson end face with its location along its inner diameter and is spring-loaded from below.
 Method to dismantle caissons with defect irradiated fuel assemblies from storage of nuclear-technological support vessels / 2498433
Invention relates to methods for radioactive wastes handling and may be used to dismantle caissons with installed defect irradiated fuel assemblies (IFA), which are in storages of nuclear-technological support (NTS) vessels. In a cavity of each caisson they add in sequence large-sized polyethylene, a mixture of crushed stone fractions, steel shots, and then Wood's alloy granules to the level of IFA brackets, afterwards the caisson is cut from the tube sheet of the storage tank, heated to melting with subsequent cooling and hardening of the Wood's alloy, afterwards a lifting cover is welded to the upper end of the caisson, and it is loaded with axial stretching load, then circular cutting of the caisson wall is carried out below location of fuel parts of the IFA with partial cutting of of the wall leaving 0.3-0.4 mm, then the axial stretching load is removed from the lifting cover, the caisson is torn off by jacks and transferred with the help of a transfer container into a transport radiation-safe container for storage and processing.
 Method to reclaim soils contaminated with radionuclides / 2498432
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 Pulsation valve submersible pump / 2493623
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 Method for space burial of radioactive wastes in far space and spacecraft for its realisation / 2492537
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 Method for removing deposit of mox-fuel from electrolysis cathode / 2489760
Method for removing deposit of MOX-fuel from an electrolysis unit cathode involves removal of the cathode with deposit of MOX-fuel from molten metal in the electrolysis unit and supply of cooling agent. After the cathode with deposit is removed from molten metal, it is exposed above molten metal till its complete efflux from the deposit. Then, the cathode with deposit of MOX-fuel is placed into a container into which cooling agent is supplied in the form of jets of liquid nitrogen or its vapours, which are directed to the deposit surface, to surface of deposit of MOX-fuel till cracks appear on the deposit; after that, the deposit is destructed mechanically and unloaded from the container.
Method for recycling of spend riteg for long-term storage / 2487431
Method for recycling of RITEG consists in total withdrawal of a radiation and thermal block (RTB) with all thermal elements (RIT) and radiation protection from depleted uranium, placement into a container, rigid fixation in it, welding of the container cover. Then the container is vacuumised, afterwards it is filled with inert gas, sealed and transported to the place of burial.
 Method of sampling radioactive sediment from storage tanks and device to this end / 2474900
Proposed method comprises full-hole drilling of well, preliminary feed of flushing fluid into strining bottom drilling pipe, and feeding drilled sediment into bottom drilling pipe. Drilled sediment inside said drilling string is subjected to additional grinding and loosening in drilling and slurrying. Suspension is transferred into protective dry box via central pipe arranged inside drilling string. Suspension is fed beck from dry box into tank. On reaching analysed interval, suspension is sampled in required volume. Besides, there is a device to sample radioactive sediment from storage tanks that comprises drilling string, cartridge with drill bit attached to bottom drill pipe. Central pipe is arranged inside drilling string and fitted in top dripping pipe via sealing assy and attached thereto by split joint. Top section of drilling pipe is brought into enclosed dry box and furnished with shutoff valve and connected to rotation drive via shaft while central pipe bottom section is furnished with rippers arranged on its outer surface.
 Device for washing out deposit and deactivation / 2458419
Device for washing out the deposit and deactivation includes working fluid pipeline with side connection pipe and with a bar connected to pipeline using detachable connections, nozzle connected by means of articulated rod to external rotating bearing race and interconnected with working fluid pipeline by means of a flexible sleeve, shaft arranged inside bar and connected through movable bearing assembly to nozzle inclination angle changing actuator, and through spline connection and toothed gear to nozzle rotating actuator, and control system. Above side connection pipe there connected coaxially to pipeline is post with support platform on which movable bearing assembly with nozzle inclination angle changing actuator and nozzle rotating actuator are installed; side connection pipe is connected to supply pipelines by means of flexible sleeve, support platform is equipped with vertical movement actuator, and side connection pipe is connected to supply pipeline by means of flexible sleeve.
 Oscillatory stirring device of annular apparatus / 2446494
Oscillatory stirring device has a nozzle assembly, a distribution cavity, a pulsation chamber with a pulse conductor and an air distributor. The pulsation chamber consists of two partition walls in the annular space of the apparatus, in the lower part of said walls of which there are holes linked to the distribution cavities entering the annular space of the apparatus. The holes in the partition walls are connected to distribution cavities which are in form of U-shaped deflectors whose bases lie adjacent to the bottom of the apparatus with a gap or to distribution cavities in form of radial tubes with nozzles directed an angle to the bottom of the apparatus. The lower connecting pipe of the pulse conductor in the pulsation chamber can have plugged end and holes on the sidewalls.
 / 2263985
 / 2265904
 / 2267179
 / 2273067
 / 2273902
 / 2273903
 / 2278430
 / 2293386
 / 2294571
 / 2316834
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FIELD: physics.
SUBSTANCE: method of cleaning soil contaminated with a strontium radionuclide involves cutting and removing vegetation, adding lime and tilling the soil. After removing vegetation, the soil on the contaminated area is loosened at a depth of 1.2-1.5 m while feeding carbon dioxide gas into the bottom part of the loosened layer and water-retaining rolls are filled around the area after adding lime and tilling.
EFFECT: invention increases efficiency of fixing the strontium isotope outside the root layer.
The present invention relates to the field of purification of soil radionuclides, including strontium, and may find use in the purification of agricultural land predominantly humid areas contaminated with radioactive fallout.
A known method of cleaning soil from radionuclides and device for its implementation (U.S. Pat. Of the Russian Federation No. 2140676, MKI G21F 9/34, BI No. 30, 1999).
According to this method, the soil stack drainage system consisting of pipe-filters made of clay powder. Water containing radionuclides, enters through the walls of the pipe-filters in drainage system and discharged into special wells. In the process of contact of radionuclides from the surface of the clay powder pipe-filters is their fixation. After exhaustion of the sorption ability of the pipe-filters removed and disposed of.
Feature strontium is the brevity of finding it in the form of mobile ions, so as interacting with organic matter of the soil sorption complex (SPC), it forms water-insoluble complexes. Therefore, the disadvantage of this method of cleaning soil from radionuclide Sr-90 is its low efficiency in the humid zone, where the washing waters are only rain or flood water, as well as the high cost of laying and retrieving tubefilter the century
A known method of cleaning soil contaminated with radionuclides Sr-90 and Cs-137. (U.S. Pat. Of the Russian Federation No. 2278428, MKI G21F 9/34, BI No. 17, 2006) According to this method, on a cleared site make fertilizing, liming the plowing and sowing a mixture of perennial grasses. Autumn grass mowed and warehoused in special vaults. This method is adopted as a prototype.
Application of lime provides increased mobility of Sr-90, so strontium with a downward current of storm or flood waters moved in the depth of the soil where the clay fraction and the lack of moisture newly forming inactive complexes.
The disadvantage of this method is the low efficiency of the process of fixation, as the isotopes of strontium may enter an inactive state only on clay soils when the moisture. During the spring flood soil moisture penetrates beyond the soil and maintains high humidity levels in the subsoils. Flood water flowing over the soil surface, wash it and make a strontium outside the contaminated area. After the cessation of surface runoff begins active drying of the surface, while soil moisture containing movable strontium, within a meter layer of the soil will pull to the surface uchastkov arable layer, returning him isotopes of strontium. Part of the soil moisture that leaked into the deeper layers of the soil, enters the groundwater, contaminating them with isotopes of strontium. This is especially dangerous when the underlying sandy soil.
The purpose of the invention is improving the efficiency of fixation of radionuclides strontium beyond the root zone of the plants and prevent the entry of their ground water and surface water run-off.
This objective is achieved in that in the known method of cleaning soil from radionuclide strontium, including mowing and removal of vegetation, application of lime and tillage of the soil, according to the invention, after the removal of vegetation on the contaminated area produce loosening the soil to a depth of 1.2-1.5 m, with a simultaneous flow in the lower part of the loosened layer of carbon dioxide, and after liming and conducting tillage on the contour plot occiput water-holding shafts.
A new technical result from application of the proposed method is that deep tillage in combination with a supply of carbon dioxide and detention of melt water on the surface of the land allow during the spring flood to lock the movable Sr-90 in the form of a practically insoluble salt SrCO3below the root zone at a depth of tilling the soil, preventing the removal of E. what about the ground water. The device shaft improves the efficiency of soil leaching and prevent removal of Sr-90 with the surface flow.
The proposed method using spring flow is as follows:
Contaminated isotope Sr-90 array is divided into parts washing. Parcel size depending on the terrain ranges from 1 to 5 ha in Autumn on plots mowed vegetation, and put it in storage. Then produce loosening to a depth of 1.2-1.5 m, solid or striped across 1,0-2,0 m digging Depth of 1.2-1.5 m adopted on the basis of limiting the depth of penetration of the main mass of roots of the plants. The distance between the stripes loosening of 1.0-2.0 m made in consideration of the magnitude of capillary moisture transfer in soils with different texture.
At the same time in the lower part of the loosened layer is injected carbon dioxide. Because carbon dioxide has a density exceeds the density of the air, it will accumulate on the digging depth. After digging on the site make applying lime fertilizers in the amount of 5-6 t/ha and plowing with the turnover of the reservoir. Then plot the contour enclosing earthen wall with a height of 0.5-0.8 m the Calcium in the lime, when interacting with ACC push from him, strontium, increasing the mobility of the latter.
Spring melt water washes away the movable isotope r-90 in the depth of the loosened layer, where carbon dioxide, interacting with water, forms carbonic acid (H2CO3which, reacting with Sr-90, forms a salt SrCO3practically insoluble in water. This ensures the fixation Sr-90 outside meter layer of the soil where the root system of most herbaceous plants does not penetrate. Water purified from isotopes of strontium, seeps below, feeding the groundwater.
After spring flood on the site make the determination of strontium in the rooting zone of the soil. If Sr-90 concentrations exceed the MPC, on the site re-produce the whole works. By reducing the content of Sr-90 to the level of the MPC shafts level and area sown crops with a fibrous root system, such as annual grasses herbs, whose root system is mainly in the topsoil (0.2-0.3 m), therefore, strontium, recorded outside meter layer of the soil in the roots of the plant does not come, and meter the thickness of the soil reduces the intensity of its radiation.
Thus, implementation of the proposed method can significantly improve the efficiency of fixation of strontium isotope beyond the root zone soil layer by translating it into an insoluble state. This fixation of strontium outside meter soil layer to provide the characteristic decrease in the intensity of its radiation.
The method of cleaning soil from radionuclide strontium, including mowing and removal of vegetation, application of lime and plowing, characterized in that after the removal of vegetation on the contaminated area produce loosening the soil to a depth of 1.2-1.5 m with a simultaneous flow in the lower part of the loosened layer of carbon dioxide, and after liming and conducting tillage on the contour plot occiput water-holding shafts.
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