RU54691U1 - INSTALLATION OF CEMENTING OF LIQUID RADIOACTIVE WASTE - Google Patents

Abstract

Usage: at nuclear power plants, radiochemical plants The essence of the utility model: Cementing liquid radioactive waste contains a lock chamber equipped with a lock compartment, a container for dry cement with additives and a cement compound preparation unit located in the protective chamber, including a container for liquid radioactive waste with a device feeding liquid radioactive waste into a container and a mixing device connected to a rotation and reciprocating drive escheniya "up-down", while protecting the floor of the chamber are laid rails passing through the airlock and ending outside the glove box, and the container is set on the rails with the possibility of entry into the containment chamber through an airlock. The installation is characterized in that it is equipped with a cement dough preparation unit located outside the protective chamber, including a dry cement tank, a water tank and an additional mixing device connected to an additional up-down rotation and reciprocating drive, while the preparation unit the cement compound is located above the container stop in the protective chamber with the possibility of interaction with the container, and the cement paste preparation unit is located above the a container mill outside the protective chamber with the possibility of interaction with the container.

Description

The utility model relates to techniques for treating materials with radioactive contamination, namely, to devices for the treatment of liquid radioactive waste LRW fixation in a stable solid medium, for example in cement with additives necessary for solidification.

The predominant use of the utility model is in the nuclear industry, but use in other sectors, for example, in the chemical and metallurgical, is not ruled out.

The curing of low- and medium-active LRW directly in containers sent for long-term storage to a stationary controlled storage facility is becoming more widespread at nuclear power plants and in nuclear research centers. Currently, active development of a project for cementing medium-level waste at the Federal State Unitary Enterprise “Mayak Production Association” is underway. The present invention is the result of part of these developments.

The cementing process directly in the container (a barrel with a volume of 200, 400, 500 liters or a reinforced concrete container with a volume of 1000 liters), installed in a protective chamber, is carried out by loading a portion of cement with additives, followed by mixing with the simultaneous supply of LRW until a cement compound is formed. When cement is loaded into a container and cement is mixed with LRW, dusting necessarily takes place, and dust particles dropping LRW from the container into the surrounding space of the containment chamber, which increases the degree of radioactive contamination of the environment surrounding the container and the container itself. To exclude an increase in the degree of radioactive infection

the protective chamber and the equipment located in it must be washed periodically to reduce the degree of contamination in order to continue the technological process not only for the production of the cement compound, but also for the safe removal of the container from the protective chamber and its transportation to the storage. It is necessary to solve the problem of eliminating an increase in the degree of radioactive contamination of the protective chamber by eliminating dusting of dry cement and entrainment of LRW particles and cement compound into the protective chamber.

Consider the solutions known from the prior art, similar to the claimed one, and analyze their capabilities in solving this problem.

A device for curing radioactive waste in a container is known (see Japanese Application No. 1-40319, CL G 21 F 9/16, 1980). It contains a protective chamber (in the application - a shielding heating box), a container that is docked from the inside to the hole in the plate of the protective chamber, a mixing device (in the application - a stirrer) located in the shielding casing and connected to the rotation drive and the reciprocating drive " up and down ”, and the bellows, which serves to separate the space of the protective chamber (“ dirty zone ”) from the space of the service area (“ clean zone ”) and is a flexible sealing device.

LRW and cement or concrete to be mixed are fed into the container in a certain proportion. The mixer is lowered down and introduced into the container, and after mixing the components are lifted into the casing. The resulting compound is cured directly in the container.

This device solves the problem of disinfecting radioactive waste by incorporating it into a solid, stable environment directly in a container, which is then transported to storage. However, the device does not provide design solutions, due to which the problem of eliminating dusting and emissions of LRW drops would be resolved

and even a cement compound, as well as an increase in the degree of contamination of the shielding box associated with these phenomena. And this means that it will be necessary to decontaminate it and the equipment located in it, which leads to additional capital and operating costs for the implementation of a rather expensive cementing process.

Closest to the claimed is a technical solution (see application RU 95112892 A, class G 21 F 9/16, publication date 1997.08.20, adopted as a prototype. A device for curing liquid radioactive waste (LRW) contains a container for dry cement, LRW container, LRW dispenser, compound mixing device and container The LRW curing device is made in the form of a protective chamber having a closed circuit in working condition, at the ends of which there are entrance and exit locks, a rail put is laid inside the chamber and along its floor L, along which a transport trolley with a tank mounted on it moves, pre-filled with crushed stone and cement, into which LRW are fed through a dispenser made in the form of a telescopic pipe that can move in a vertical plane.The container sealing mechanism with a compound are located in the protective chamber, the mechanism of mixing a sealed container, the mechanism of its deactivation after mixing, and the mechanism for installing this container in an airtight container for subsequent burial, while the mechanism of mixing the container ensures the rotation of the sealed container in a vertical plane.

In this device, an attempt is made to eliminate those disadvantages that are observed in the previously described analogue, i.e. the device is equipped with many mechanisms and means to reduce the level of radioactive contamination of the chamber space due to dusting of dry cement, ejection of droplets of LRW and compound. To do this, there are mechanisms for decontamination of the dispenser and the sealed container, as well as a mechanism for mixing the latter. In addition, as part of the famous

The device provides for the presence of both a sealed container and a container. Their presence in the device indicates insufficient deactivation of the container, which is why it must be hidden in a container.

However, it is well known that the more different mechanisms are in one device, the more difficult it is to successfully manage it, and especially at radiochemical enterprises, where this control is most often remote. As a result, there are high capital costs for the purchase of equipment, and operating costs.

In this regard, a technical solution was created that is the subject of patent protection for this application.

The inventive utility model will exclude an increase in the level of radioactive contamination inside the protective chamber, since when using this utility model for cementing LRW there will be no dusting of cement, which means there will be no entrainment with dust of drops of LRW and the cement compound.

The inventive utility model, like the prototype, contains a protective chamber equipped with a lock compartment, a container, a container for dry cement with additives and a cement compound preparation unit located in the protective chamber, including a liquid radioactive waste container with a liquid radioactive waste feed device and a mixing device connected to the drive rotation and with the drive of the reciprocating movement "up and down", while the rails passing through the airlock compartment and ending outside total chamber, and the container is mounted on rails with the possibility of entry into the protective chamber.

The installation differs from the prototype in that it is equipped with a cement paste preparation unit located outside the protective chamber, including a container for dry cement with additives, a water tank and an additional mixing device connected to an additional rotation drive and a reciprocating drive

up-down movement, while the cement compound preparation unit is located above the container stopping place in the protective chamber with the possibility of interaction with the container, and the cement dough preparation unit is located above the container stopping point outside the protective chamber with the possibility of interaction with the container.

It should be noted that the applicant accepted the following features to be identical in the inventive installation and in the known device (as they are listed in the restrictive part of the utility model formula).

the gateway compartment is identical to the entrance gateway;

the container is identical to a container filled with cement and crushed stone;

cementing liquid radioactive feed device identical to LRW dispenser;

the mixing device is identical to the device for mixing the compound (mixing mechanism of a sealed container);

drives of rotation and reciprocating movement "up and down" is identical to the sign "... telescopic pipe, having the ability to move in a vertical plane";

the container is mounted on rails with the possibility of entry into the protective chamber identical to the transport trolley with a tank mounted on it.

The inventive utility model meets all conditions of patentability.

It has novelty, since the applicant has not identified a technical solution from the prior art characterized by the same set of essential features.

The utility model is industrially applicable, since the installation itself and its features are feasible and reproducible; nothing in the proposed technical solution does not contradict and does not interfere with their use in industrial production with the achievement of the expected technical result.

Proof of this is the following description of the construction of a cementing plant for liquid radioactive waste and its operation.

In the drawing - a General view of a specific installation.

The installation comprises a protective chamber 1, equipped with a lock compartment 2, a container 3, a container 4 for dry cement with additives and a unit for preparing a cement compound located in the protective chamber 1, including a container 5 for liquid radioactive waste (LRW) with a feed device 6 (LRW) in the container 3 and the mixing device 7 in the form of two vertical paddle mixers connected to the drive 8 of rotation and reciprocating movement "up and down". Rails 9 are laid along the floor of the protective chamber 9, passing through the lock compartment 2 and ending outside the protective chamber 1 in the so-called “clean zone” 10. The container 3 is mounted on the rails 9 with the possibility of entering the protective chamber 1 through the lock compartment 2 from the “clean zone” "10. The ability to enter the container 3 can be carried out, for example, using a transport trolley 11 or another vehicle mounted on rails 9, plying from the" clean zone "10 into the protective chamber 1 through the lock compartment 2.

The installation is equipped with a cement dough preparation unit located outside the protective chamber 1 in the “clean zone” 10, including a container 4 for dry cement with additives, a water tank 12 and an additional mixing device 13 in the form of two vertical paddle mixers connected to an additional rotary drive 14 and return - translational movement "up and down".

The site of preparation of the cement compound, namely, the lower end of the device 6 feed LRW and mixers 7 are located above the stop in the protective chamber 1 of the truck 11 with the container 3, and the site of preparation of the cement paste, namely, the lower end of the device 15 of the supply of cement with additives, lower end of water supply device 16 and agitator 13

located above the stop outside the protective chamber 1, in the "clean zone" 10, the cart 11 with the container 3.

Installation works as follows.

The cart 11 with the container is located at the stopping point in the “clean zone" 10. The mixers 13 are driven by the drive 14 into rotation and translational movement "down" for entry (interaction) into the container 3, which serves cement with additives and water in a predetermined ratio T: G. The components are mixed until a homogeneous mixture - cement paste. The agitators 13 drive 14 return "up" to its original position. The airlock compartment 2 and the trolley 11 are opened, moving along the rails 9, enter the protective chamber 1. Here, the trolley 11 with the container 3 reaches the stopping place. LRW is supplied to the container 3 with the cement dough from the tank 5 through the device 6. The drive 8 is turned on, the mixers 7 rotate and move “down”, enter (interact with ...) into the container 3, in which mixing takes place until the cement slurry is homogeneous with LRW, receiving a cement compound. The container 3 is removed from the protective chamber 1 for further solidification and final transportation to the storage.

The use of the claimed utility model in the disposal of LRW at radiochemical enterprises and nuclear power plants will result in the following advantages:

the preparation of cement paste outside the protective chamber will exclude an increase in the level of radioactive contamination in it, since there is no dusting of cement, and the dusting of cement at the place of preparation of the cement paste outside the protective chamber will not cause radioactive contamination, since there are no LRW and not yet hardened compound there;

The installation, which is simple in design, will not require an increase in capital and operating costs in comparison with a device - a prototype. Contamination of the protective chamber will be within acceptable limits, due to the level of activity of the waste itself.

Claims (1)

A cementing unit for liquid radioactive waste containing a protective chamber equipped with a lock compartment, a container, a container for dry cement with additives and a cement compound preparation unit located in the protective chamber, including a container for liquid radioactive waste with a device for supplying liquid radioactive waste to the container and a mixing device connected with the drive of rotation and reciprocating movement "up and down", while the rails passing through the sluice are laid along the floor of the protective chamber a new compartment and ending on the outside of the protective chamber, and the container is mounted on rails with the possibility of entering the protective chamber through the airlock compartment, characterized in that the installation is equipped with a cement paste preparation unit located outside the protective chamber, including a container for dry cement, a water tank and an additional mixing a device connected to an additional drive rotation and reciprocating movement "up and down", while the site of preparation of the cement compound is located above the places m stopping the container in a glove box capable of cooperating with the container, and the cement slurry preparation unit is disposed above the point where the stop of the container outside the glove box to interact with the container.