RU2637380C1 - Device for conditioning radioactive ion exchange resins - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: device consists of a container for curing radioactive ion exchange resins (IER) with a filling control sensor, IER pulp tanks equipped with a pipeline for loading the IER pulp and a pipeline for transporting the IER pulp. The device includes a dehydrating and dosing unit equipped with a pipe of the IER pulp return, an overflow pipe of the IER pulp, a recirculation system, a recirculation liquid return pipe with a stop valve; a vibrating plate, the IER curing container is provided with a IER pulp filling and distributing pipe, an upper mesh forming the upper drainage cavity, and a lower mesh, a polymer binder pipe mixer with a polymer resin supply pipe, a pipe of feeding the hardener, and a perforated nozzle to increase the homogeneity and supply of the finished polymer binder; the IER pulp transporting pipeline is equipped with a dosing pump for controlling the IER pulp transportation.

EFFECT: improving the quality of the final product.

1 dwg

Description

The invention relates to the field of processing of radioactive waste, in particular radioactive ion-exchange resins (IOS), and is intended for conditioning them by incorporating into epoxy resin-based polymer compositions.

A known method of polymer curing for radioactive waste (KR 101154875 (B1)), which describes a device for polymer curing of radioactive waste, including tanks for IOS and polymeric materials, a mixing tank for mixing radioactive waste with a polymer binder with a mixing blade, a mixer and a drum for the final product . IOS and a polymer binder are fed into the mixing tank using a metering pump and mixed using a paddle mixer. After mixing, the finished compound through the second mixing tank is metered into the drums to obtain the final cured product.

The disadvantages of this method are:

- low quality of the final product due to non-compliance with the ratio of IOS and polymer binder due to the lack of dosing equipment for IOS, providing an accurate ratio of components. Due to the lack of equipment for dehydration of IOS, excess moisture enters the finished compound, which also leads to deterioration in the quality of the final product;

- increased design complexity due to the presence of several tanks to obtain a mixture of IOS with a polymer binder.

A device for processing ion-exchange resins is known (JP No. 57 010 400 (B4)), which contains a reservoir for radioactive waste, a squeezing centrifuge and a container for curing spent resins, the base of which is mounted on a hydraulic lifting mechanism. After dehydration in a centrifuge, the spent ion-exchange resins are fed into the container. The polymer binder is fed into the container through a polymer binder component mixer equipped with a mixer.

The disadvantages of the known device are:

- low quality of the final product due to non-compliance with the ratio of IOS and polymer binder due to the insufficient accuracy of the dosage of IOS carried out by the time of the centrifuge and the lack of equipment that allows dosage by weight or volume. The low quality of the final product is also associated with the conditions for impregnation of the IOS, in which the polymer binder enters the surface of the IOS in the container, since the outlet for the input of the polymer binder is located in the top lid of the container;

- increased design complexity associated with the presence of a mixer with an agitator for a polymer binder, a lifting mechanism with hydraulic drive and a drive for rotating the centrifuge.

Closest to the proposed device is a device for the curing of radioactive waste (US 5 416 251 (A62D 3/00)), containing a container for curing IOS with a filling control sensor, IOS pulp capacity, equipped with an IOS pulp loading pipeline, a water supply pipe and a transportation pipeline IOS pulps, a container for a substitute solution, containing a pipeline for filling it and a pipe for supplying a substitute solution in a container for curing IOS, a container with a mixer for a polymer binder, containing w conduit for feeding the polymer binder in a container with a stirrer, a conduit for transporting the polymer binder in the finished container for curing ILE pump for transporting the finished polymer binder to cure in a container ILE tube with flexible sleeve for introducing into a container of polymer binder to cure the ITS. The IOS curing container has an upper branch pipe for removing residual liquid from the upper part of the container, connected to a pipeline and a pump for removing liquid, a recessed pipe for removing residual liquid from the bottom drainage cavity formed by a drainage mat, connected to a pipe and a pump for removing liquid from the bottom of the container .

The disadvantages of the device are:

- reduced quality of the final product due to the lack of equipment for accurate dosing of radioactive IOS, as a result of which it is impossible to comply with the ratio of IOS and polymer binder, and the lack of equipment for uniform distribution of IOS when filling the container for curing IOS, as a result of which voids form in the container. The reduced quality of the final product is also associated with the presence of a flexible hose nozzle in the device for introducing a polymer binder into the central part of the container for curing IOS, which does not allow for uniform distribution of the polymer binder over the entire area of the container, as a result of which local zones form in the volume of air-conditioned IOS not impregnated with a polymeric binder;

- reduced reliability and safety of the device due to the lack of equipment for the controlled transportation of radioactive IOS to the container for curing IOS and the formation of stagnant zones in the pipeline for the transport of pulp IOS; the formation of plugs in the pipeline for transporting the finished polymer binder and a nozzle with a flexible sleeve for introducing the finished polymer binder into the container for curing IOS due to the increase in viscosity of the finished polymer binder during its preparation and transportation, which leads to the need for additional maintenance with dismantling and replacement of elements devices

- an increase in the amount of secondary radioactive waste associated with the need to regularly supply additional water to the IOS pulp tank in order to provide the possibility of feeding the pulp of the radioactive IOS to the IOS curing container, as well as the use of a replacement solution to displace excess water from the radioactive IOS supplied from the tank for a replacement solution.

The technical result achieved by the proposed device is to improve the quality of the final product, increase the reliability and safety of the device, reduce the amount of secondary radioactive waste.

The specified technical result is achieved by the fact that a device for curing radioactive ion-exchange resins is proposed, consisting of an IOS pulp tank equipped with an IOS pulp loading pipeline and an IOS pulp transportation pipeline; metering pump; a dewatering and dosing apparatus equipped with an IOS pulp return pipe, an IOS pulp overflow pipe with shutoff valves and an IOS pulp discharge pipe with shutoff valves; a recirculation system consisting of a residual fluid drain pipe, a pump, a recirculation tank, a recirculation fluid supply pipe with shutoff valves to the dewatering and dosing apparatus, a recirculation fluid supply pipe to the IOS pulp tank with shutoff valves, a vibro plate, an IOS curing container equipped with a control sensor filling, pipe filling and distribution of pulp IOS, the upper grid, forming the upper drainage cavity under the lid of the container, the lower grid, form a bottom drainage cavity, an upper branch pipe for the removal of residual liquid from the upper drainage cavity into the recirculation system, a deepened branch pipe for the drainage of residual liquid from the bottom drainage cavity into the recirculation system, a polymer binder pipe mixer equipped with a pipe for supplying polymer resin, a pipe for supplying a hardener and a perforated nozzle to increase homogeneity and supply the finished polymer binder.

Distinctive features of the proposed device is that:

- the IOS pulp transportation pipeline is equipped with a metering pump;

- the composition of the proposed device includes a dehydration and dosage apparatus equipped with an IOS pulp return pipe, an IOS pulp overflow pipe with shutoff valves, an IOS pulp discharge pipe with shutoff valves;

- the device has a recirculation system consisting of a residual fluid drain pipe, a pump, a recirculation tank, a recirculation fluid supply pipe equipped with shutoff valves, to a dewatering and dosing apparatus, a recirculation fluid supply pipe to the IOS pulp tank equipped with shutoff valves;

- the IOS curing container is equipped with an upper mesh forming the upper drainage cavity, a lower mesh forming the bottom drainage cavity, an IOS pulp filling and distribution pipe, a polymer binder mixer with a pipe for feeding polymer resin, a pipe for feeding the hardener and a perforated nozzle;

- the composition of the proposed device includes a vibratory platform on which a container for curing IOS is installed.

The IOS pulp transport pipeline equipped with a metering pump increases the reliability and safety of the device, allowing controlled transport of the IOS pulp, which eliminates the formation of stagnant zones in the IOS pulp transport pipeline.

The dehydration and dosing apparatus improves the quality of the final product due to the exact portioned dosing of the IOS, which allows to maintain the desired ratio between the IOS and the polymer binder. Accurate batch dosing of IOS is achieved by the fact that the IOS pulp return pipeline ensures maximum filling of the dewatering and dosing apparatus and the removal of an excessive amount of IOS pulp back to the IOS pulp tank, and the IOS pulp overflow pipe with shut-off valves and the IOS pulp discharge pipe with shut-off valves allow separating the excess the settled liquid and excess IOS pulp after holding the IOS pulp in the dehydration and dosing apparatus and form a portion of the IOS pulp for discharge into the curing container Nia ITS.

The recirculation system reduces the amount of secondary radioactive waste by reusing residual liquid. The residual fluid drain pipe and the residual fluid drain pipe pump provide dewatering of the IOS in the container for curing the IOS and supplying the residual liquid to the recirculation tank for collecting it, a pipeline for supplying the recirculating liquid to the pulp tank of the IOS with shut-off valves and a pipe for supplying the recirculating liquid to the dehydration and dosing apparatus with shut-off valves provide reuse and recirculation of the collected residual fluid.

Upper mesh forming the upper drainage cavity, lower mesh forming the bottom drainage cavity, IOS pulp filling and distribution nozzle, IOS pulp feeding into the central part of the IOS curing container, polymer binder mixer with perforated nozzle to increase homogeneity and supply the finished polymer binder located under the lower grid, can improve the quality of the final product by ensuring the effective separation of residual liquid from the pulp of IOS uniform distribution of the polymeric binder during its passage upwards through the bottom and top grid during impregnation ILE.

In addition, the polymer binder tube mixer with a pipe for supplying polymer resin and a pipe for supplying a hardener increases the reliability and safety of the device due to the separate supply of polymer resin and hardener, which eliminates the premature initiation of the curing process of the polymer binder, increasing its viscosity and the formation of plugs in elements of the device.

The presence of a vibratory platform on which the IOS curing container is installed improves the quality of the final product by ensuring uniform distribution of IOS in the container for curing IOS, its effective dehydration and uniform impregnation with a polymer binder by vibration exposure to IOS.

In FIG. 1 presents a diagram of the inventive device for the curing of radioactive ion-exchange resins.

The device consists of an IOS 1 pulp loading pipeline, an IOS 2 pulp tank, an IOS 3 pulp transportation pipeline with a metering pump 4, a dewatering and metering device 5 with an IOS 6 pulp return pipe, an IOS 7 pulp overflow pipe with shutoff valves 8 and a pulp discharge pipe IOS 9 with shutoff valves 10, a curing container for IOS 11 with a filling control sensor 12, an IOS 13 filling and distribution pulp nozzle 13, a polymer binder pipe mixer 14 equipped with a pipe for supplying polymer resin 15, p a hardener feed nozzle 16 and a perforated nozzle 17. The container is provided with a lower mesh 18 forming a bottom drainage cavity 19, an upper mesh 20 forming a upper drainage cavity 21, a buried residual fluid outlet pipe 22 to remove residual fluid from the bottom drainage cavity 19, and an upper nozzle the removal of residual fluid 23 to remove residual fluid from the upper drainage cavity 21. Also, the device is equipped with a vibrating plate 24, a pipeline for the removal of residual fluid 25, a pump 26, capacity p recirculation 27, recirculation fluid supply pipe 28 with shutoff valves 29, recirculation fluid return pipe 30 with shutoff valves 31.

The device operates as follows.

Through the IOS 1 pulp loading pipeline, the IOS radioactive pulp is loaded into the IOS 2 pulp tank. From the IOS 2 pulp tank through the IOS 3 pulp transportation pipeline, with the help of the metering pump 4, the IOS radioactive pulp is sent to the dehydration and dosing apparatus 5. The dehydration and dosing apparatus 5 is completely filled with IOS pulp, an excess of which is discharged through the IOS 6 pulp return pipeline to the IOS 2 pulp tank. In the dehydration and dosing apparatus 5, the pulp is aged and the excess settled is discharged liquid and excess pulp IOS into the capacity of the pulp IOS 2 through the overflow pipe pulp IOS 7 with the open position of the shutoff valve 8. Turns on the vibrating platform 24. Through the discharge pipe pulp IOS 9 when the open position of the shutoff valve 10 and the pipe filling and distribution of the pulp IOS 13 is unloaded IOS into the container for curing IOS 11 into the space between the lower grid 18 and the upper grid 20. Using the pump 26, the IOS is dehydrated in the container for curing IOS 11 by removing liquid from the bottom drainage floor 19 through the recessed branch pipe for the discharge of residual liquid 22 and from the upper drainage cavity 21 through the upper pipe for the discharge of residual liquid 23. Through the pipeline for the discharge of residual liquid 25, the residual liquid is supplied to the recirculation tank 27. Using the recirculation fluid supply pipe 28 with the valves 29 open, the IOS residues are washed out from the dehydration and dosage unit 5 into the IOS 11 curing container. Thus, a precisely measured volume of IO is fed into the IOS 11 curing container C, equal to the working volume of the container for curing the IOS 11. With the shut-off valve 10 closed, the pump 26 conducts the evacuation of the IOS in the container for curing the IOS 11. Then the polymer resin is fed into the pipe binder of the polymer binder 14 through the pipe for feeding the polymer resin 15 and the hardener through the pipe for supplying the hardener 16. The polymer binder obtained after passing through the pipe mixer through the perforated nozzle 17 for entering the finished polymer binder enters the bottom drainage cavity 19. As the polymer binder arrives, the bottom drainage cavity is filled, the IOS is uniformly impregnated with it in the direction from the bottom up, and the upper drainage cavity is filled. The filling of the container for curing IOS 11 with a polymer binder is monitored using a filling control sensor 12. After filling the container for curing IOS 11 with a polymer binder, the vibrating plate 24 is turned off, the filling and distribution pipe for the pulp of IOS 13, the pipe for feeding polymer resin 15, the pipe for feeding hardener 16, the recessed residual fluid outlet pipe 22 and the upper residual fluid pipe 23 are sealed with screw caps. The curing container of the IOS 11 is sent to the holding zone for curing the polymer binder, and then to the radioactive waste storage. To reuse and control the moisture content and fluidity of the IOS pulp, as well as to ensure the possibility of its transportation, the recirculation liquid from the recirculation tank 27 is supplied to the IOS 2 pulp tank through the recirculation fluid return pipe 30 when the shutoff valve 31 is open.

Claims (1)

A device for conditioning radioactive ion-exchange resins, consisting of an IOS curing container with a fill control sensor, an upper residual liquid branch pipe, a buried residual liquid branch pipe, an IOS pulp tank equipped with an IOS pulp loading pipe and an IOS pulp transportation pipe, characterized in that it has a dewatering and dosing apparatus equipped with an IOS pulp return pipe, an IOS pulp overflow pipe with shutoff valves and a pulp discharge pipe And OS with shutoff valves, a recirculation system consisting of a residual fluid drain pipe, a pump, a recirculation tank, a recirculation fluid supply pipe with shutoff valves, a recirculation fluid return pipe with shutoff valves; a vibratory platform on which a container for curing IOS is installed; The IOS curing container is equipped with an IOS pulp filling and distribution nozzle, an upper mesh that forms the upper drainage cavity, and a lower mesh that forms the bottom drainage cavity, as well as a polymer binder with a pipe for feeding polymer resin, a pipe for feeding hardener and a perforated nozzle for increase homogeneity and supply of the finished polymer binder; the IOS pulp transportation pipeline is equipped with a metering pump for controlling the IOS pulp transportation.

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