RU2713916C1 - Method for transfer of spent rods of control and protection from off-duty covers for spent fuel assemblies - Google Patents

Abstract

FIELD: nuclear physics and equipment.

SUBSTANCE: invention relates to nuclear power engineering. Disclosed is a method of reloading spent rods laid in cells of off-grade covers for SFA and placed in storage facilities of coastal technological bases (CTB), in standard sleeves for SFA. Protective container with off-standard cover is installed in the loading station, in each cell of which there is not more than three rods, and the second protective container with empty standard jacket. Pedestals are installed on both containers and plugs are opened on both jackets. Hydraulic clamping device (HCD) and coordinate-clamping device (CCD) are installed on pedestal of first container. HCD working chamber is brought into the cell of the off-grade jacket through the loading opening. Working chamber is filled with an alcohol-glycerine mixture to pressure of not more than 1 MPa. Grip with rod is lifted from cell jacket above CCD by 40÷50 mm. Gripper is disengaged from the rod. Channel container is installed on the coordinate-aiming device (CAD). Rod is loaded into a free cell of the case.

EFFECT: invention allows reducing surface contamination with radioactive substances and emission of radionuclides at overload of defective CPS rods.

3 cl, 10 dwg

Description

The invention relates to the field of nuclear energy, in particular, to methods for the treatment of solid radioactive waste of a high degree of activity (SRW HLW), and can be used for reloading spent defective control and protection rods (CPS), improperly stacked in cells of defective covers for spent fuel assemblies (SFA), which are located in the storage facilities of coastal technical bases (BTB).

A defective CPS spent rod is a CPS rod discharged from the reactor together with the spent core, cut into two parts: a low active upper part and a high active lower part with a highly active neutron moderator, and deformed during cutting or overloading. When cutting the CPS rod in the cutting zone, a violation of the geometry of the diameter of the rod and the occurrence of barbs may occur. When transporting and overloading the highly active part of the CPS rod, a violation of the rod geometry along the length is possible, as well as the occurrence of a spill of the neutron moderator.

A defective (non-standard) cover for the SFA is a cover for transportation and storage with the following possible defects: deformation of the bayonet connection of the suspension of the pipe part with the cork, depressurization of the cover, and curvature of the lower part of the cover.

In accordance with the Federal Target Program for the Utilization and Rehabilitation of Nuclear Facilities in 1995-2017. The main works were carried out on the decommissioning, disposal and temporary storage of nuclear submarines and surface ships, the rehabilitation of coastal and floating technical bases with SFA storage facilities and CPS rods.

As a result of these works, a large number of CPS rods unloaded from nuclear power plants (NPPs) of the 1st and 2nd generations were formed. At present, the full-time storage facilities for spent CPS rods are completely full, and the problem of storing newly unloaded CPS rods has become urgent, because FSUE Mayak PO cannot accept them for processing due to the fact that the technology of processing a neutron moderator has not yet been mastered.

The decision of the leadership of the State Atomic Energy Corporation Rosatom and the Russian Navy determined the temporary storage of spent CPS rods as solid radioactive waste of a high degree of activity (SRW HLW) in vacant storages and in cases for SFA.

CPS rods from SFAs differ in mass and size characteristics. The CPS rods exceed the SFAs in length by more than 0.5 m, but are smaller in weight by about 8-10 times and the outer diameter by about 2.5 times. The indicated weight and size characteristics allow the use of covers for SFAs when storing CPS rods in the SFA storages for storage, with a segment of the low-active upper part of the CPS rod, which goes into further circulation as solid radioactive waste of low activity level (SRW NAO), and the remaining parts of the CPS rods (SRW VAO) load in covers for SFA. No more than 3 CPS rods are loaded into each cell of the cover, which is determined by the inner diameter of the cover cell and the outer diameter of the CPS rods.

When NAO parts are cut off and loading under the power of HLW parts of the CPS rods into the cells of the covers, including substandard ones, burrs and irregularities of the geometric shape occur, which makes it impossible to reload the CAO parts of the CPS into the standard cases for the SFA using standard collet, ball and tick captures. The absence of a standard head of the CPS rod (after cutting off the NAO part), the relatively small diameter of the cell cover for the SFAs and the relatively small gaps between the CPS rods also cannot provide unloading of the CPS rods with standard grips, and this leads to a significant increase in the complexity of work and, therefore, additional exposure to personnel and the environment.

The use of standard methods of handling spent control system rods, which were abnormally stacked in the cells of the SFA covers, including the capture of the control system rods, drawing them into a transfer container and their further transportation for processing, is impossible due to their high degree of defectiveness and destruction. The dismantling of CPS rods with similar defects from the cells of the SFA covers in a regular way can lead to uncontrolled release of high-level radioactive substances into the environment, which will negatively affect the health of personnel and the environment.

A known method of connecting a pipe gripper "Standart" (supplier LLC "SDS-11", a distributor of COLLI DRILL GROUP in Russia and the CIS countries) with a polyethylene pipe. Fixation of the pipe with a grip occurs due to the input of the grip into the inner diameter of the pipe and the subsequent screwing of the eyebolt, while the gear segments of the collet expand and fix the pipe to the grip. The more traction you need to pull the pipe, the more revolutions of the eyebolt need to be done to better grip the grip with the pipe.

However, this method can only be used to grip the grip with plastic pipes and with a minimum inner diameter of 25 mm, and the inner diameter of the spent control rod of the control rod is less than 19 mm. In addition, this method can only be used for coupling pipes with the intact geometry of the inner hole of the pipe.

There is a method of unloading spent CPS rods from floating technical bases (PTB) and loading them into the reactor of a decommissioned nuclear submarine, described in the report of NIKIET JSC No. 111.41.42 "Transport and technological scheme for loading the CPS shells into the reactors of utilized nuclear submarines for the Nerpa Shipyard, Zvezdochka CS OJSC, Zvyozdochka CS OJSC, SVRTS OJSC, Zvezda DVZ OJSC, Moscow, 2012. Since 1997, as a container for long-term aging of HLW parts CPS rods use reactors of utilized nuclear shipbuilding facilities After unloading of these cores.

The technology for implementing this method of unloading spent CPS rods from PTB storage facilities or standard CPS systems of reactors and then loading them into places of unloaded reactor active zones reduces to cutting the CPS rods to the size of the screen assembly so that they subsequently do not interfere with the seal of the reactor cover, for which purpose :

- raising the liners above the reactor cover to the required height (a significant increase in the radiation level is thus excluded, since the upper part of the sleeve is in the reactor cover and is weakly activated during operation);

- fixation in a special device;

- trimming the upper part to the required size of the lower part of the sleeve into the reactor (SRW HLW);

- installation of the tip in the lower part of the sleeve in the place of the cut and welding it to the sleeve to ensure subsequent connection with the gripper sb. 26-1 OK-300PB;

- lowering the sleeve with highly active parts of the CPS until it stops down.

The disadvantages of the method:

- when welding the tips there are additional labor costs and dose loads on the staff. The operation of welding a tip in an area of increased activity provokes the release of radioactive aerosols into the environment;

- only temporary storage is provided in the reactor compartments of the disposed submarines of the solid radioactive waste of the radioactive waste, parts of the CPS rods, which contradicts Federal Law No. 190-FZ of July 11, 2011, “On the Management of Radioactive Waste and on Amending Certain Legislative Acts of the Russian Federation”, in accordance with who need to carry out the disposal of SRW radioactive waste.

Closest to the technical nature of the claimed method is the "Method and device for reloading and fault detection of irradiated fuel assemblies that are in defective covers" according to patent No. 2373588, according to which a working area for overloading and fault detection of SFAs containing four adjacent technological ones in the storage floor is formed cells equipped with guide funnels mounted on retractable supports, with which they provide a vertical arrangement of covers loaded into the cells; The defective cover is transferred using a cover container from the storage cell and lowered through the guiding funnel to the first technological cell, after which they start overloading the SFA located in this cover, for which a channel pulling device creates a controlled pulling force, while the SFA pulled out with force less than 80 kgf, load through a pointing device into a standard case located in the second technological cell, SFA, elongated with a force within 80-120 kgf, load through a pointing device GUSTs amplified in Case disposed in the third processing cell, and if the generated force exceeds 120 kgf, these spent fuel assemblies are left in the defective pouch and its overload cheholnym container through the guide funnel in the fourth cell equipped with a thin-walled hermetic pencil case.

After transshipment and detection of spent fuel assemblies, they are sent for processing in air-conditioned packaging.

The disadvantages of the method:

- transshipment work is carried out in the SFA storage facility, that is, in the zone of increased radiation hazard, which will negatively affect the amount of dose loads on personnel and the environment;

- the capture of a regular channel container will not provide overload of the cut off highly active part of the CPS rods.

The objective of the present invention is to provide a method for overloading the CPS rods from substandard SFA covers to air-conditioners.

The implementation of the present invention will allow to obtain a technical result in the form of reducing and minimizing surface contamination with radioactive substances and radionuclide emissions during overload of defective CPS rods, as well as reducing the time spent by CPS rods outside the cover and eliminating spills of a neutron absorber, which will reduce the absorbed radiation dose of maintenance personnel and radioactive environmental pollution.

The specified technical result is obtained due to the fact that according to the proposed method, a protective container with spent CPS rods is installed in a substandard case in each loading cell, in each cell of which no more than three CPS rods are loaded, and a second protective container with an empty air conditioner cover, then onto both set the pedestals of the container and open the plugs from substandard and air-conditioned covers; on the pedestal of the first container with a substandard cover, a hydraulic clamping device (GZP) and a coordinate clamping device (KZU) are installed, through the loading hole of which a working chamber of the GZP is brought into the cell of the substandard cover and installed between the laid rods, after which the working chamber is filled with an alcohol-glycerin mixture to pressure no more than 1 MPa, fixing the position of the rods, then through the boot hole of the KZU to one of the fixed rods fail capture with installed self-tapping screw with a removable head, which is directed with the help of a short-circuit breaker to the center of the cavity of the rod and, turning the gripper, cut the self-tapping screw into the rod until it stops, then release the pressure in the working chamber of the hydraulic breaker, then the gripper with the rod is raised from the cover cell by 40 ÷ 50 mm above the short-circuit breaker providing access to the self-tapping screw and the head of the rod, which is clamped in the short circuit block, the grip is unhooked from the rod and the grip is removed from the defective rod unloading area, the head is screwed off with the self-tapping screw and the necessary correction of the head part of the rod is made, then channel container, the grip of the channel container is engaged with the part of the self-tapping screw protruding from the rod, the KZU is opened and the rod is loaded into the cavity of the channel container, then the channel container is installed on the coordinate-guiding device (KNU) mounted on the pedestal of the second protective container and the rod is loaded into the channel a free cell of the cover, the operation of reloading the rods is repeated until all cells of this cover are completely filled, after which the KNU is removed from the pedestal of the second container, set for shield plug on the cover, and then transport the container to the loading zone in the TUK.

A special case of the proposed method is that, if necessary, before the start of the overload, the deformed bayonet joint of the tube plug suspension is edited.

The next special case of the proposed method is that the alcohol-glycerin mixture is prepared from a composition of alcohol with glycerin in the optimal composition (in% by weight):

- alcohol - 50%;

- glycerin - 50%.

The introduction of an empty working chamber of the horizontal drainage chamber and its guidance with the help of a television camera, as well as loading into the upper lateral space of the cover cell that is not filled with control rods, does not present technological difficulties, and filling the working chamber with an alcohol-glycerin mixture under a pressure of not more than 1 MPa contributes to its expansion and reliable fixation (compression) CPS rods between each other and the inner wall of the cover cell. When depressurizing the working chamber, it is freely removed from the cavity of the cell cover.

The use of the alcohol-glycerin mixture eliminates the appearance of secondary LRW, which could have occurred when using other working hydraulic fluids (water, oil) that penetrated the cell of the case (during emergency depressurization of the working chamber of the clamping device), since the alcohol component will evaporate and the glycerol component will settle on the walls of the cell cover with subsequent curing.

A grip having a self-tapping screw with a taper thread similar to self-tapping screws will reliably crash when rotating an irregular geometric shape even in the presence of relatively large burrs, when the pipe thickness is not more than 1.0-2.0 mm, and the material - GOST 5632 steel 08Kh18N10T GOST 5632. This steel grade has good ductility, which will ensure strong screwing of the self-tapping screw with the CPS rod and the corresponding adhesion force when pulling the gripper cover with the CPS rod from the cell of the grip (reliability of adhesion).

The invention is illustrated by the following graphic figures:

- FIG. 1 - Loading post for reloading the CPS rods from substandard covers for SFAs into air-conditioned covers and its technological equipment;

- FIG. 2 - Section AA. The location of the CPS rods in the cells of the cover with the installation of the working chamber;

- FIG. 3 - Section B. The location of the CPS rods in the cells of the cover for the SFA with the installation of the working chamber of the receiver in the upper space of the cell cover;

- FIG. 4 - Section AA. The working chamber of the hydraulic fracturing device in the expanded state under the pressure of the working fluid, the control rods are fixed;

- FIG. 5 - Section B. The working chamber of the hydraulic fracturing device in the expanded state under the pressure of the working fluid, the CPS rods are fixed, the capture is directed to the center of the cavity of the CPS rod;

- FIG. 6 - Section B. Capture with a self-tapping screw, introduced by the method of screwing, in the center of the cavity of the rod of the CPS;

- FIG. 7 - Schematic diagram of the hydraulic circuit;

- FIG. 8 - Structural-kinematic diagram of the KZU;

- FIG. 9 - Provisions of the removed and installed traffic jams in covers of protective containers;

- FIG. 10 - Installation of the channel container over the short circuit switch.

The proposed method of overloading the CPS rods located in substandard SFA covers is carried out in the following order.

In the SFA loading post 1, a container 2 is installed with three CPS 3 rods placed in each cell of the substandard cover 4, and a container 5 with an empty air conditioning cover 6 for the SFA (Fig. 1).

SFA loading stations 1 are available at BTB, ATO vessels and nuclear shipbuilding and ship repair enterprises for channel and cover loading and unloading of SFAs.

On the bottle part of containers 2 and 5, pedestals 7 and 8 are installed, which perform the functions of biological protection and have the ability to install the necessary technological equipment and equipment on them for unloading and loading defective CPS rods.

On the pedestal 7, a coordinate clamping device (KZU) 9 with clamping mechanisms with prismatic jaws, a camera and a backlighting device, a screen bioprotection 10 and a hydraulic clamping device (GZP) 11 are sequentially installed (Fig. 1).

Through the channels of the base of the KZU 9 (not shown in the figures) and the internal cavity of the container 2, a cable and a camera 13 with a backlight 14 are introduced into the upper lateral space of the cell 12 of the cover 4 (Fig. 1 - Fig. 3).

Through the boot hole (through groove) KZU 9 enter the capture 15 and the working chamber 16 with the tread 17 of the PPP 11 (Fig. 1 - Fig. 5).

GZP 11 consists of a plunger pump type RGN 18 with a manual drive, widely used in factories of the shipbuilding industry. The pump RGN 18 is equipped with a drain tank 19, a drain valve 20, a check valve 21, a pressure gauge 22 and a mounting bracket 23. The pressure port of the pump 18 is connected through a check valve 21 and a rigid pipe 24 to the working chamber 16, which is protected by the tread 17. (Fig. 1 , Fig. 7).

The capture 15 consists of a housing 25, a screw 26, a self-tapping screw 27 and a screw 28 (Fig. 6). The housing 25 is fully welded, has an opening for installing the screw 26, a threaded hole for installing the screw 28, and coaxial square and cylindrical holes for installing the self-tapping screw 27. The screw 26 is inserted into the opening of the housing 25 to create a torque when inserting the self-tapping screw 27 into the internal cavity of the control rod 29 The screw 28 secures the self-tapping screw 27 from falling out of the housing 25. The self-tapping screw 27 consists of a housing 30 with a tapered thread, on which is fixed a square head 31 screwed into the housing 30.

KZU 9 is designed to guide the capture 15 and the working chamber 16 with the tread 17 to the head of the inner cavity of the rod CPS 29 in the cell of the substandard cover 4 and the subsequent retention of the rod CPS 29 and the working chamber 16 of the GZP in clamping mechanisms (Fig. 5, Fig. 6) .

KZU 9 is composed of a fixed base 32 (Fig. 8) mounted on a pedestal 7, a carousel 33 mounted on ball bearings 34. A carriage 35 is mounted on the carousel 33, on the guides of which there is a guidance and clamping mechanism for gripping 36 and a guidance and clamping mechanism 37 the working chamber GZP 11. KZU 9 has the ability to guide the capture 15 and the working chamber 16 GZP in two horizontal coordinates due to the manual drive 38 (screw-nut) using socket wrenches 39 and in the angular coordinate by manually turning the carousel 33 and fixing p position by turning the stopper latch 40.

The work on the overload of spent control rods located in substandard SFA covers according to the claimed method is carried out in stages in the following sequence.

Preparatory work for the reloading of spent control rods 3 located in substandard SFA 4 covers is carried out in loading post 1.

Loading post 1 should be equipped with the following standard handling equipment and accessories:

- channel container 41 with a grip for the heads of the CPS rods, a traverse and a centering funnel 46 (Fig. 10);

- a cover container 42 with a grip for the heads of the SFA covers and a traverse (Fig. 1);

- coordinate-guiding device (KNU) 43 for loading the CPS rods into the cells of the SFA cover (Fig. 1);

- a set of equipment for removing or coupling the plug from the cover;

- a set of empty air conditioning covers 6 SFA (Fig. 1);

- a set of cameras 13 and lighting 14 (Fig. 1, Fig. 3, Fig. 5);

- two protective containers 2 and 5 of type TK-12.

The loading station 1 should be located in the service area of the bridge or portal crane 44 of the corresponding lifting capacity, as well as a cantilever-slewing crane-beam (KPKB) 45 (Fig. 1).

If necessary, edit the deformed bayonet connection of the suspension of the plug of each substandard cover 4 according to the method described in patent No. 2373588.

The overload of defective CPS rods from substandard covers in the conditional is as follows. In the loading station 1 (Fig. 1), a container 2 with a substandard OVS cover 4 is installed, in each cell of which no more than three CPS rods are placed, and a container 5 with an empty air conditioner cover 6. The installation of containers 2 and 5 in the loading station 1 is carried out using bridge or gantry crane 44. Using the same crane 44, pedestals are mounted on both containers 2 and 5: on the container 2 - pedestal 7, on the container 5 - pedestal 8. Pedestals 7 and 8 provide the necessary biological protection for personnel from gamma radiation and have the ability to install the necessary equipment and technological equipment for operations overload control rods of the fuel assemblies 4 covers substandard conditioning in 6 cases.

Through the internal channels of the base 32 of the KZU 9, a television cable with a television camera 13 with a backlight 14 (not shown in the figures) is inserted into the inner cavity of the cell of a substandard cover 4. For preliminary alignment of the guidance and clamping mechanism of the gripper 36 with respect to the unloading cell of the substandard cover 4, a laser pointer, for example, Green Lazer, is installed in the gripping gripper 36, and using a laser beam, alignment is made using the spindles 38 and the circular carousel movement 33 sec its subsequent locking with the latch 40. After preliminary alignment from the clamping gripping device 36, the laser pointer is removed (Fig. 8).

Using KPKB 45 in the guidance and clamping mechanism of the rigid pipe 37 through the boot hole 49 (Fig. 8) in the caliper 35 and the carousel 33 install the pipe 24 (Fig. 3), which is connected to the working chamber 16 and is protected by the tread 17. Using the chassis screws 38, socket wrenches 39 and the rotation of the carousel 33 aim the working chamber 16 with the tread 17 on the inner cavity of the substandard cover 4 cell, and the working chamber 16 with the tread 17 is lowered into the empty side space (Fig. 2). The rigid pipe 24 is connected via a quick disconnect connection (BRS) 46 to the RGN 18 hand pump, the working chamber 16 is filled with an alcohol-glycerin mixture 47 to a pressure of not more than 1 MPa, while the working chamber 16 is expanded with the tread 17 and the CPS rods are fixed to each other and the cell wall case 4 (Fig. 4, Fig. 5).

Using KPKB 45, a gripper 15 with a self-tapping screw 27 is installed in the guidance and clamping mechanism of the gripper 36 and the final guidance of the gripper 15 with a self-tapping screw 27 is made using one of the spindles 38, socket wrenches 39 and the carousel 33 to one of the control rods 4 located in the cell cover 4 (Fig. 6).

Disengage the gripper 15 with a self-tapping screw 27 from the slings of KPKB 45, unclench the guidance and clamping mechanism of the gripper 36, and then using the winch 26, rotating the gripper 15, insert the self-tapping screw 27 with a tapered thread, similar to self-tapping screws, into the internal cavity of the rod CPS 29 until fully inserted (Fig. 6).

Grip 15 with a self-tapping screw 27 screwed into the inner cavity of the control rod 29, sling with KPKB 45, and then relieve pressure in the working volume 16. Using KPKB 45 capture 15 with a tapping screw 27 and screwed rod CPS 29 is lifted from the cell cover 4 and clamped into the guidance and clamping mechanism of the gripper 36 is 40 ÷ 50 mm higher than the short circuit switch and the level embedded in the rod of the control rod 29 of the self-tapping screw 27.

With a self-tapping screw 27, a square head 31 is screwed (Fig. 6) and the necessary editing of the head part of the CPS rod is performed with a bench tool. Thus, the head part of the CPS rod with a self-tapping screw without a square head 31 has become identical to the standard head of the CPS rod.

On the pedestal 8 of the container 5 with a conditional cover 6, a standard channel coordinate-guiding device (KNU) 43 is installed (Fig. 1).

Above KZU 9, a regular channel container 41 (Fig. 10) is installed through a centering funnel 46, equipped with a standard control for the CPS rod, and it engages with the head part of the self-tapping screw 27 fixed to the CPS rod 29, after which the guidance and clamping mechanisms of the gripper 36 are unclenched and load into the cavity of the channel container 41 (not shown in Fig.).

The channel container 41 is rearranged on KNU 43 and the CPS rod is unloaded into a free cell of the conditional cover 6. The operations of reloading the rods from the substandard cover 4 to the conditional 6 are repeated until all cells of the conditional cover 6 are completely filled (no more than three CPS rods in each cell of the cover) (Fig. 1).

KNU 43 is removed from the pedestal 8 of the container 5, the plug 48 (Fig. 9) is installed on the air conditioner cover 6, then the case container 42 is installed on the pedestal 8, into which the air conditioner case 6 with spent control system rods is loaded, and then it is loaded into TUK transport container for temporary storage and its further shipment to FSUE “Mayak” for processing of the control system or long-term storage.

Monitoring of operations on the reloading of the CPS rods is carried out using a camera 13 and a backlight 14.

Thus, in the described method, the problem of radiation-safe overload of defective CPS rods from substandard SFA covers to air-conditioned SFA covers unused for their intended purpose is solved.

Claims (5)

1. The method of reloading spent rods laid in the cells of substandard covers for SFA and located in the storage facilities of coastal technological bases (BTB), in conditional covers for SFAs, in which they form a working area for loading conditional covers with rods into transport packaging kits (TUK), characterized the fact that a protective container with a substandard cover is installed in the loading station, in each cell of which no more than three rods are laid, and a second protective container with an empty conditional cover, then on both containers Nera set pedestals and open plugs on both covers; on the pedestal of the first container, a hydraulic clamping device (GZP) and a coordinate-clamping device (KZU) are installed, through the loading opening of which a working chamber of the GZP is brought into the cell of the substandard cover and installed between the laid rods, after which the working chamber is filled with an alcohol-glycerin mixture to a pressure of not more than 1 MPa, fixing the position of the rods, then through the boot hole of the KZU to one of the fixed rods, a gripper with a self-tapping screw installed in it with a removable head, cat they are guided with the help of a short-circuit breaker to the center of the cavity of the rod and, rotating the gripper, they cut the self-tapping screw into the rod until it stops, then release the pressure in the working chamber of the horizontal disassembly, then the gripper with the rod is raised from the cover cell by 40 ÷ 50 mm above the short-circuit breaker, providing access to the self-tapping screw and the head of the rod, which is clamped in the short circuit block, detach the grip from the rod and remove the capture from the defective rod unloading area, screw the head off the self-tapping screw and make the necessary correction of the head of the rod, then install it over the short circuit through a centering funnel the channel container is engaged, the channel container is engaged in engagement with the self-tapping part protruding from the rod, the KZU is opened and the rod is loaded into the channel container cavity, then the channel container is installed on the coordinate-guiding device (KNU) mounted on the pedestal of the second protective container, and through the hole in KNU load the rod into a free cell of the cover, the operation of reloading the rods is repeated until all cells of this cover are completely filled, after which the KNU is removed from the pedestal of the second container , install the protective plug on the cover and then transport the container to the loading area of the TUK. 2. The method of reloading according to claim 1, characterized in that, if necessary, before the beginning of the overload, the deformed bayonet joint of the tube plug suspension is edited. 3. The method of overloading according to claim 1, characterized in that the alcohol-glycerin mixture is prepared from a composition of alcohol with glycerin in the composition,% by weight: - alcohol - 50; - glycerin - 50.

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