RU2756329C1 - Radiometric device for remote monitoring of vessel tightness - Google Patents

Abstract

FIELD: radioactivity measurements.

SUBSTANCE: invention relates to a device for monitoring the tightness of vessels containing highly toxic radioactive materials. The radiometric device for remote monitoring of the tightness of the vessel consists of a metal body with a removable lid, on which a tightness control fitting, pass-through electrical hermetic connectors, a pressure equalization valve and a movable rod with an alpha radiation source are fixed. The body has the ability to overlap the controlled area of the vessel, in which sealed pass-through devices are located, and testing equipment with radiometric alpha radiation sensors. The sensitive elements of the alpha radiation sensors are fixed by means of clamps on the outer surface of the vessel in the controlled area near the existing sealed butt joints, and the sensors are connected to the external recording equipment and the power supply unit through the electrical hermetic connectors of the lid.

EFFECT: possibility of conducting remote periodic monitoring of the vessel’s tightness for the release of highly toxic radioactive materials in the places of sealed butt joints of the vessel’s pass-through devices.

5 cl, 4 dwg

Description

The invention relates to the field of devices designed to control the tightness of vessels containing highly toxic radioactive materials.

Known container for patent RU No. 2157009, IPC G21F 5/005, G21F 5/008, publ. 09/27/2000, containing spent nuclear fuel (SNF), which includes a hermetic overlap of the inner cavity of the container, made in the form of at least two removable protective covers installed one above the other and forming sealing contours with the body with the formation of cavities, each of which made with a channel for communication with a device for tightness control (UKG). A blind hole is made in the housing on the outside, which is hermetically closed by an additional removable cover (SC) with the formation of an additional cavity under it, with which the mentioned channels are communicated. The additional SC forms sealing contours with the body with the formation of another cavity, which is made with a channel for communication with the CCG. An additional branched channel is made in the additional SC for communication of the additional cavity with the CCG.

This device makes it possible to control the tightness of the container loaded with SNF without removing the outer protective covers, but it cannot be used for remote control of the tightness of the vessel.

Known packaging for radioactive material according to US patent No. 4447733, IPC G21F 5/12, publ. 05/08/1984, which contains a radiation-absorbing vessel having an inner plug-type lid that seals the inner cavity of the vessel, and an outer protective lid that covers the middle plug-type lid and defines a gap between them, in which the gas can be monitored to detect seal failure. The outer lid is hermetically sealed on the vessel so that the cavity between it and the inner lid is isolated from the atmosphere. According to the invention, this cavity is pumped with gas at a pressure higher than atmospheric pressure, which is also higher than the pressure inside the vessel, and the pressure in the space between the outer protective and inner covers is controlled. A drop in pressure signals a failure of any seal between the plunger-type cover and the vessel, or between the protective cover and the vessel.

This device provides the ability to control the tightness of the vessel by pumping pressure into the interopercular cavity, however, it requires equipment for pumping pressure, and it cannot be used where it is technically impossible to pump pressure into the cavity or for other reasons (for example, in terms of the safety of the release of radioactive contents ).

The technical result consists in the possibility of remote periodic monitoring of the tightness of the vessel for the release of highly toxic radioactive materials in the places of hermetically sealed butt joints of the passage devices of the vessel.

The technical result is achieved by a radiometric device for remote control of vessel tightness, consisting of a metal body with a removable cover, on which are fixed the tightness control nipple, through electrical hermetic connectors, a pressure equalization valve and a movable stem with an alpha radiation source, the body has the ability to overlap the controlled area of the vessel, in of which there are sealed pass-through devices, and testing equipment with radiometric alpha-radiation sensors, the sensitive elements of which are fixed by means of clamps on the outer surface of the vessel in the controlled area near the existing sealed butt joints, the sensors are connected to external recording equipment and the power supply through electrical hermetic connectors of the lid ...

In execution options:

- the metal body is collapsible and consists of hermetically connected cylindrical and conical parts;

- the pressure equalization valve is made in the form of a hydrophobic labyrinth cartridge;

- sensitive elements are made flexible, the basis of which is a polymer optical fiber;

- the latch is made in the form of a magnetic strip having grooves for accommodating the sensor's sensitive elements passing under it.

The design of the metal body is collapsible, which allows its installation on a controlled vessel in separate parts without the use of lifting equipment.

The presence of a tightness control nipple makes it possible to check the tightness of the connections of the device's components at the places where the sealing elements are installed and at the place where it is connected to the controlled vessel.

The presence of through electrical hermetic connectors allows the sensors to be connected to the power supply and recording equipment located outside the device, from which the measurement data are then transmitted via a cable communication line to a personal computer.

The design of the valve in the form of a hydrophobic-labyrinth cartridge eliminates deformation of the device body, which can subsequently lead to its depressurization, due to constant pressure equalization between the ambient pressure and the controlled area, thereby ensuring the safety of the device, regardless of operating conditions in the event of large pressure drops and temperatures.

The presence of a movable rod with a source of alpha radiation makes it possible to calibrate the testing equipment, made in the form of radiometric sensors of alpha radiation with sensitive elements, without additional access to the controlled area, while the rod is moved manually.

The presence in the device of flexible sensitive elements of the alpha-radiation sensor, which have the ability to take the shape of the required control zone, allows their position to be fixed on a metal surface with magnetic properties using a magnetic strip, in the grooves of which they are placed, and to fix the release of highly toxic radioactive materials into in case of loss of tightness of the vessel.

FIG. 1 shows a general view of the device (view from the end of the controlled vessel), FIG. 2 - view A in FIG. 1, FIG. 3 - section b-b in Fig. 1, FIG. 4 - remote element B in Fig. 2.

The device 1 consists of several hermetically sealed parts: a metal body 2 and a cover 3.

The body 2, for the possibility of its installation without lifting devices on the controlled vessel 4, is made composite and has a cylindrical 5 and conical 6 parts, hermetically connected by means of sealing elements 7, 8. The hermetic installation of the body 2 on the controlled vessel 4 is carried out thanks to the sealing element 9.

The cover 3 of the device 1 has holes for installing electrical hermetic connectors 10 and 11, through which communication is carried out between the testing equipment 12 located inside the device 1 and the recording equipment 13 with the power supply unit 14 located outside it. The connection between the testing equipment 12 and the recording equipment 13 with the power supply unit 14 is carried out through the harnesses for taking readings 15 and the harnesses for supplying power 16.

In the center of the cover 3 of the device 1 there is a movable rod 17, on one side of which an alpha radiation source 18 is installed and secured with a nut, and on the other side there is a sleeve 19 and a nut with a locking screw 20, on the outer side of the sleeve 19 there is a hexagon for rotation her key. To maintain the tightness of the device 1 when moving the movable rod 17, grooves with sealing elements 21 installed in them are provided on its surface.

The tightness of the device 1 is controlled through the fitting 22 on the cover 3. The tight connection of the fitting 22 with the cover 3 is ensured by the sealing element 23.

In order to equalize the pressure as a result of a change in the outside temperature, as well as to prevent moisture from entering the inside of the device with these changes, the design provides for the installation of a pressure equalization valve 24, made in the form of a hydrophobic-labyrinth cartridge, protected from the outside from mechanical influences by a cover 25 with grooves for the possibility of free air passage.

The testing equipment 12 consists of alpha-radiation sensors 26 and sensing elements 27, fixed on the outer surface of the vessel 4 in the controlled area near the existing sealed butt joints, with the help of clamps 28, made in the form of magnetic strips, in the grooves of which they are placed.

Installation of device 1 is carried out in the following sequence:

- the cylindrical part 5 of the body 2 of the device 1 is installed on the controlled vessel 4 and fixed through the threaded holes;

- on the surface of the controlled vessel 4, the alpha-radiation sensors 26 are fixed and the sensing elements 27 are wired near the sealed butt joints of the controlled vessel 4 using the clamps 28;

- install and fix in the threaded holes of the cylindrical part 5 the conical part 6 of the device 1 using the sealing element 7 and standard fasteners;

- the source of alpha radiation 18 is fixed on the movable rod 17 by means of a nut;

- by rotating the sleeve 19, a control check is made of the movement of the movable rod 17 from one extreme position to another. Restriction of the movement of the movable rod 17 on the one hand occurs due to the collar at its end, and on the other hand, due to the collar on the sleeve 19;

- make a docking to the sealed connectors 10 and 11 of the harnesses for taking readings 15 and harnesses for supplying power 16 from the alpha radiation sensors 26;

- install and fix the cover 3 into the threaded holes of the conical part 6 using a sealing element 8 and standard fasteners;

- the device 1 is checked for leaks, for which pressure is applied through the fitting 22, while instead of the cover with grooves 25, a cover with a sealing element is installed on the hydrophobic-labyrinth cartridge 24 (not shown in the drawing). After a tightness test, the cover with a sealing element is replaced by a cover with 25 grooves;

- the testing equipment 12 is calibrated, for which the alpha radiation source 18, fixed on the movable rod 17, is brought as close as possible to the sensitive elements 27 of the alpha radiation sensor 26 by rotating the sleeve 19. The perceived signal from the alpha radiation sensors 26 through the readout harnesses 15 enters the recording equipment 13, from which the measurement data is transmitted via a cable communication line, to a personal computer (not shown in the drawing);

- after calibration, the movable rod 17 with the alpha radiation source 18 is removed from the alpha radiation sensor 26 to the maximum possible distance at which the sensitive elements 27 of the alpha radiation sensor 26 do not react to the alpha radiation source 18 available on the rod 17.

In the operating mode, the device 1 installed on the controlled vessel 4 remotely monitors the radiation situation. In the event of the release of radioactive content, the sensitive elements 27 of the alpha-radiation sensor 26 send a signal to the recording equipment 13, from which the measurement data are then transmitted via a cable communication line to a personal computer.

Claims (5)

1. Radiometric device for remote control of vessel tightness, consisting of a metal body with a removable cover, on which are fixed the tightness control nipple, electrical feed-through sealed connectors, a pressure equalization valve and a movable stem with an alpha radiation source, the body has the ability to overlap the controlled area of the vessel, in which there are sealed pass-through devices, and testing equipment with radiometric sensors of alpha radiation, the sensitive elements of which are fixed by means of clamps on the outer surface of the vessel in the controlled area near the existing sealed butt joints, the sensors are connected to the external recording equipment and the power supply through electrical hermetic connectors of the lid. 2. Radiometric device for remote control of vessel tightness according to claim 1, characterized in that the metal body is collapsible and consists of hermetically connected cylindrical and conical parts. 3. Radiometric device for remote control of vessel tightness according to claim 1, characterized in that the pressure equalization valve is made in the form of a hydrophobic-labyrinth cartridge. 4. Radiometric device for remote control of vessel tightness according to claim 1, characterized in that the sensitive elements are made flexible, the basis of which is a polymer optical fiber. 5. Radiometric device for remote control of vessel tightness according to claim 1, characterized in that the locks are made in the form of a magnetic strip having grooves for accommodating the sensor's sensitive elements passing under it.

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