RU2328047C1 - Process of radioactive component localisation in insulated vessel, and safety barrier system - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: to localise radioactive components, two technological metal vessels are placed at the insulated vessel surface. The two vessels are insulated against that surface and used for oil seal production. Before casting of cement grout containing ionising radiation absorption components, a hole is drilled in the insulated vessel through the oil seal of one of the technological vessels, radiation control is conducted, and in the same vessel a removable filtre unit is installed to absorb gas-aerosol fraction of the radioactive substance in the insulated vessel. Then the second hole is drilled in the second technological vessel for cement grouting and monitoring of insulated vessel infill. The holes are sealed by half-turn ball valves after filling, filling system and filtre unit are undocked, then the technological vessels are sealed. Radiation control is run constantly during the whole localisation process. Removable filtre unit is double-stage, the first stage containing water and noxious gas vapour sorbents, the second stage containing a Petryanov Filtre.

EFFECT: better safety of operations with radioactive substances.

4 cl, 1 dwg

Description

The invention relates to the field of environmental protection and is a means of localizing radioactive components containing a gas-aerosol fraction in sealed containers.

The invention can be used in the nuclear industry and other areas where it is required to preserve toxic substances of various kinds that are in sealed containers, to exclude their release into the environment for a long storage time.

A known method of isolation of solid radioactive waste from the environment. (Pat. RF №2153720 from 03/26/199, publ. 07/27/2000). The method includes creating an underground reinforced concrete container divided by reinforced concrete partitions into sections, installing perforated pipes in sections higher than the section height, creating holes for perforated pipes in reinforced concrete slabs and openings arranged along the longitudinal axes of reinforced concrete slabs, filling holes, filling them thermoplastic material, filling sections of the tank with solid radioactive waste, pouring them with a mixture of non-radioactive cement ora with an inorganic sorbent, monolithic waste by holding the cement slurry to form cement stone, closing sections of the concrete tank with reinforced concrete slabs, drilling holes through the thermoplastic material, installing technological pipes in the well, heating thermoplastic material to seal the joints, pumping cement mortar through the technological pipes removal of process pipes, sealing of reinforced concrete slabs, sampling through perforated pipes from the tank.

The disadvantages of this method are:

- increased environmental hazard when implementing the method for the localization of radioactive materials (r / m) that are in sealed containers and incorporating a gas-aerosol component or capable of active formation of aerosols in contact with atmospheric air;

- the lack of a system for filtering gases displaced from the cavities when pouring concrete mixture, and operational control of the displaced gas entering the environment;

- possible release of toxic gases into the environment, as when drilling through thermoplastic material, the necessary degree of sealing of the contact point between the drill and thermoplastic material is not provided;

- extraction from wells to the surface of the technological pipes used to fill the tank with concrete mix.

A known method of creating radiation protection around a radioactive component, a protective shield from radiation from a cellular cement mortar. (US Pat. No. 6046377 dated 10/06/1998, IPC G21F 9/00).

The method mainly includes preparing a container in which the radioactive component is placed, preparing a cellular cement mortar, which includes a cement mortar, a finished foam material, a bentonite gel and ionizing radiation absorbing material, pumping the cellular cement mortar into the container. Cement mortar is prepared during the localization of the radioactive component, the solution is supplied to the pump and injected under pressure through an injection hose, which is connected to a pumping device, which communicates with the inner part of the protective shell built around the protective chamber with the radioactive component. The protective shell is made of a sufficiently light steel sheet, which allows you to create a shell in a faster and more economical way.

The objective of the above method is to provide shielding of the "hot" components in the reactor chambers by erecting a protective shell from a sufficiently light steel sheet, which allows you to create a shell in a faster and more economical way, filling it with a fluid solution that absorbs ionizing radiation.

The disadvantage of this method and device is the inability to ensure radiation safety in the localization of radioactive components containing a gas aerosol fraction that are under high pressure in sealed containers. The method is narrow-profile and cannot be extended to the localization of toxic components of various profiles in other industries.

The objective of the present invention is to provide a universal method and device of increased safety for the localization (burial) of highly active r / m containing a gas-aerosol component, or capable of active formation of aerosols in contact with atmospheric air, located in a sealed container under high pressure.

The technical result of the claimed invention is to increase the safety of work with radioactive substances during their localization by reducing the release of hazardous and toxic components into the environment.

The technical result is achieved by the fact that in the known method for the localization of radioactive components contained in a sealed container, including the preparation of a container, the preparation of a cement slurry containing components that absorb ionizing radiation, pouring cement into a container, the preparation of the container consists in the fact that on its upper two technological metal containers are installed on the surface, they are sealed against this surface, oil gates are arranged in them, before filling a cement solution containing components that absorb ionizing radiation, drill a hole in an airtight container through an oil shutter of one of the technological tanks, perform radiation monitoring, install a removable filtration unit in the same technological tank that absorbs the gas-aerosol component of radioactive substances in the pressurized container, then a second hole is drilled through an oil shutter of another technological tank in a sealed tank, cement grout is poured ora, controlling the filling of the cavity of the sealed container through the first hole, after each drilling, the drill is discharged into the cavity, after filling, the holes are sealed, the filling system and filtering unit are undocked, then the technological tanks are sealed, and radiation monitoring is carried out continuously throughout the entire localization process .

The technical result is achieved by the fact that in the protective barrier system localizing the radioactive components containing the sealed container, the container filling system with liquid flowing cement containing the components absorbing ionizing radiation, two technological metal containers are sealed on the upper surface of the container, oil gates are arranged in them, through which drill holes in the container, ball valves are installed to close the holes after drilling and filling the cement container a saline solution, in one of the processing of metal containers a removable filter assembly, wherein the system is provided with a radiation monitoring equipment.

The filtration unit can be a two-stage filter, the first stage of which is sorbents for sorption of water vapor and harmful gases, the second stage is a filter made of Petryanov’s fabric. Ball valves can be made semi-turn.

The installation of two technological metal containers with oil gates and ball valves helps to increase safety when working with a sealed container in which highly active radioactive materials containing a gas aerosol component are under pressure. To localize the drilling fluid, drilling is carried out through oil gates, the gases escaping from the container are bubbled in oil, and the bursting gases settle on the filter, which is installed in one of the technological tanks.

Continuous monitoring of the pollution of the second stage of the filtration unit and radiation monitoring of the cleaned gas emitted into the environment makes it possible to control the breakthrough of radioactive aerosols and, when the filtration efficiency decreases, the filters are replaced. Thus, the safety of work with a radiation hazardous facility is increased and the risk of environmental pollution by radioactive substances is reduced.

Discharging drills after drilling into the container cavity also helps to reduce the risk of radioactive substances entering the environment and personnel exposure during work. At the moment the drill is discharged into the container cavity, the technological capacity is blocked with a ball valve and an additional check of the hole sealing reliability is carried out, the degree of which is judged by the behavior of the oil layer poured from above onto the hemisphere of the ball valve.

Ball valves installed in technological tanks, after filling the container with liquid cement, reliably seal the holes through which the technological operations described above were carried out.

The execution of ball valves half-turn speeds up the sealing process and, thereby, helps to minimize the exit time of harmful products.

A cement mortar containing components that absorb ionizing radiation is prepared sufficiently liquid to ensure uniform spreading over the internal volume of the cavity and to prevent premature (until the entire tank is filled) monolithic.

After filling the tank, with continuous monitoring of the filling of the cavity, purification of the displaced gas by the filtration unit and radiation monitoring of the cleaned gas emitted into the environment, the cement mortar is exposed to the formation of cement stone, additional sealing of technological tanks is carried out, etc. reliable localization of container contents is achieved.

The use of a two-stage filter increases reliability and safety when working with the objects in question. The first stage, which is a zeolite sorbent, serves to absorb toxic gases and moisture from the displaced gas medium, and the second stage, made of Petryanov’s fabric, is designed to deposit radioactive aerosols on the filter.

Thus, the task and the technical result, which is to increase the safety of the work carried out and the safety of the environment, are confirmed by a combination of the claimed features of the method of localization (burial) of highly active r / m, incorporating a gas-aerosol component, or capable of active aerosol formation upon contact with atmospheric air in a sealed container under high pressure, and a protective barrier system.

In FIG. Shows a general view of the protective barrier system, which implements the localization method, where:

1 - container (sealed metal container) with radioactive components inside;

2, 3 - technological metal containers;

4, 5 - half-turn ball valves;

6 - filtration unit.

Equipment for drilling, pouring cement and radiation monitoring equipment are not shown.

The inventive method is implemented as follows. Two technological metal containers (2, 3) are installed on the container (sealed metal container), on its outer surface, and they are sealed relative to this surface. They poured thick technical oil with high viscosity. Then, through a technological container (2), filled with oil, a hole is drilled in an airtight container (1), after which the drill is dropped into the cavity of the container and the ball valve is closed. A removable filtration unit (block) is hermetically installed on the technological vessel (6), a ball valve is opened and, with constant radiation monitoring, overpressure is vented through the filtration unit. Then, a second hole for pouring the cement mixture is drilled through the oil shutter in the second technological tank (3), the drill is dropped into the cavity of the container, the ball valve in the second technological tank is closed and the cement pouring unit is tightly connected to it. A ball valve is opened in the second technological tank and pouring liquid cement mixture containing components that absorb ionizing radiation, while continuously monitoring the pollution of the second stage of the filtration unit and radiation monitoring of the cleaned gas emitted into the environment. After filling the container (1) with a solution of the cement mixture, the cement pouring unit and the filtration unit (6) are undocked and the technological containers are sealed.

The inventive method of localization and a protective barrier system reliably localize the radioactive substances in the container and can significantly reduce their potential danger to personnel and the environment. This is confirmed by the results of radiation monitoring during the work and upon completion.

The inventive method and system are universal, because can be used:

for the safe transportation of r / m, incorporating a gas-aerosol component, to the places of their burial;

to increase the degree of safety of containers (containers) with highly active containers located directly in the warehouse;

for localization of r / m in the cavities of the boxes and other technological tanks during their decommissioning;

for preservation of the tanks located underground, in which experiments were carried out using r / m.

Claims (4)

1. The method of localization of radioactive components contained in an airtight container, including preparing the tank, preparing a liquid cement mortar containing components that absorb ionizing radiation, pouring the cement mortar into the tank, characterized in that the preparation of the sealed tank is that on its upper surface install two technological metal containers, seal them relative to this surface, organize oil gates in them, before pouring the cement mortar, with containing components that absorb ionizing radiation, drill a hole in an airtight container through an oil shutter of one of the technological tanks, perform radiation monitoring, install a removable filtering unit in the same technological tank that absorbs the gas-aerosol component of radioactive substances in the pressurized container, then through the oil the shutter of another technological metal tank is drilled a second hole in the sealed tank and cement is poured, to ntroliruya filling the container through the first opening, after each drilling bit is dropped into cavity container is sealed after filling openings produce undock filling system and filter unit, followed by sealing the process tanks, the radiation control produce continuously throughout the localization process. 2. A protective barrier system that localizes the radioactive components contained in an airtight container, including a system for filling the container with a fluid cement mortar containing components that absorb ionizing radiation, characterized in that two technological metal containers are sealed on the upper surface of the container, and oil gates are arranged in them through which holes are drilled in the container and ball valves are installed to close the holes after drilling and filling the container ementnym solution in one of the processing tanks has a removable filter assembly, wherein the system is provided with a radiation monitoring equipment. 3. The protective barrier system according to claim 2, characterized in that the removable filtration unit is made in two stages, the first stage is sorbents for sorption of water vapor and harmful gases, the second stage is a filter made of Petryanov’s fabric. 4. The protective barrier system according to claim 2, characterized in that the ball valves are made half-turn.