RU2759056C1 - Guide clamping device - Google Patents

Abstract

FIELD: nuclear energy.

SUBSTANCE: invention relates to the field of nuclear energy, in particular to methods of handling solid radioactive waste of a high degree of activity. The guiding clamping device contains a base plate and a rotary plate; on the base plate, ball bearings are horizontally mounted, on which a rotary plate is coaxially mounted with a stop end position lock and a support installed along an axis passing through the center of rotation of the rotary plate. The caliper has two clamping mechanisms installed on the slide guides with two manual screw drives providing axial reciprocating movement along the caliper, and four clamping prisms are installed perpendicular to the axis of the caliper in the grooves of the clamping mechanism bodies, the compression-expansion of which is performed by four manual screw drives. To install the spent fuel assemblies in the area of the clamping prisms, the base has a through axial cylindrical hole with a diameter equal to the outer diameter of the SFA canister, and in the rotary plate there is an oval hole, which is located symmetrically to the center of rotation of the rotary plate with a distance between the centers of the oval equal to the center-to-center distance of oppositely located peripheral of the SFA canister cells with a hole width at least 10 mm larger than the diameter of the SFA canister cell.

EFFECT: improvement of technological capabilities for guiding and reloading abnormally laid SFAs, repairing the head of SFAs, which ensures a decrease in radioactive contamination of the environment.

1 cl, 5 dwg

Description

The invention relates to the field of nuclear energy, in particular, to methods of handling solid radioactive waste of a high degree of activity (HLW SRW) and can be used when re-covering and handling spent defective fuel assemblies (SFA), stacked abnormally in the cells of defective casks for spent fuel assemblies or in storage cells of coastal technical bases (BTB), nuclear service vessels (ATO) or in protective transport containers (TC).

Defective SFA is a fuel assembly unloaded from the reactor and deformed during refueling or technological handling. In this case, a violation of the geometry of the fuel assembly is possible, as well as the occurrence of spillage of fuel elements in places where corrosion processes occur.

A defective SFA bag may have the following deviations from the norm:

- deformation of the bayonet connection of the tube part suspension with the plug;

- depressurization of the cover;

- curvature of the body.

Known guiding devices 1054.02.00.000 OKB "Izhora Plants", which have become widespread in BTB, ATO ships and shipyards. They are used to orient the reloading canal container sb.02 when unloading and loading spent fuel assemblies into the cells of casks for spent fuel assemblies and for orienting a single-cover basic container of the KB-651 type with slots of a transport container of the TK-18 type when loading and unloading casks from spent fuel assemblies and at the same time ensuring radiation safety maintenance personnel during these operations. Operations for loading and unloading spent fuel assemblies into casks for spent fuel assemblies using the specified guidance device are carried out at a special loading station, and for loading and unloading casks with spent fuel assemblies into a transport container of the TK-18 type, the guidance device is installed on the end of the TK-18 container body.

Such guiding devices have one fixed and two movable plates with manual drives and worm gears, and the loading holes of the upper movable plates are made with eccentricity relative to the axis of the lower fixed plate. Such a design of the targeting device ensures high accuracy of guidance of overloaded spent fuel assemblies, but does not allow loading and unloading defective spent fuel assemblies and casings due to their defectiveness, destruction and abnormal placement.

Known guiding device for removing side reflectors, patent No. 2581100. The invention can be used to extract side reflectors from a nuclear reactor with a liquid metal coolant. The device contains a base, a rotary plate with a drive, a telescope and a mechanism for its movement. The telescope is made with the possibility of passage between the control and protection system mechanism and the wall of the reactor monoblock (MBR), is mounted on the telescope movement mechanism (MPT) trolley connected to the rotary plate, and can be docked with the reflector head. MPT is made in the form of a trolley moving along guides on a rotary plate. The MPT drive is made in the form of a screw mechanism, the screw of which is fixed on the rotary plate with the possibility of rotation, and the nut, with the ability to move along the screw, is fixed on the MPT trolley. The drive for moving the telescope guide tube is made in the form of a screw mechanism, the screw of which is installed eccentrically relative to the telescope body with the possibility of rotation. Such a device does not allow loading and unloading defective spent fuel assemblies with a high degree of defectiveness, destruction, and placed abnormally.

Known guiding device for aligning one product with another when reloading products according to patent No. 2161588. The guiding device contains a base and a guide tube for guiding the movement of the gripper, a large and small rotary plates with offset axes of rotation and drives that provide access to a given coordinate in the service area, and a screw jack. The jack includes a screw mounted with the possibility of free rotation from the drive on the guide tube, a nut with a sleeve having guide rollers and a rigid stop limiting the movement of the nut with a sleeve along the guide pipe. The guide tube contains a vertically moving core with a collar and an opening for the balls. The holes have tapered chamfers to restrict the balls from falling out towards the center, and grooves and a chamfer are made in the lower part of the sleeve to interact with the said balls. The chamfer is made with a reverse taper to go from the groove diameter to a diameter that accommodates the specified core. The guide tube is installed in a small swivel plate.

Such a device does not allow large values of the vertical movement of the guide element, thereby not providing loading and unloading of defective spent fuel assemblies with a high degree of defectiveness, destruction and placed abnormally. However, this device is technically the closest to the claimed guidance clamping device and therefore is taken as a prototype.

The objective of the present invention is to create a guiding clamping device (NCD) for reloading defective spent fuel assemblies that have been placed abnormally in storage cells or from defective canisters into conditioned canisters for spent fuel assemblies.

The implementation of the present invention will provide a technical result in the form of acquiring technological capabilities for guiding and reloading abnormally stacked spent fuel assemblies, repairing the head of the spent fuel assemblies, which ensures a decrease in radioactive contamination of the environment.

Obtaining the specified technical result is ensured due to the fact that according to the presented invention, the guiding clamping device contains a support and a rotary plate, and on the support plate, ball bearings are horizontally mounted, on which a rotary plate is coaxially mounted with a position lock with a thrust end and a support installed along the axis, passing through the center of rotation of the pivot plate, while the support has two clamping mechanisms installed on the slide guides with two manual screw drives, providing axial reciprocating movement along the support, and four clamping prisms are installed perpendicular to the axis of the support in the slots of the clamping mechanism bodies, compression - which are unclamped by four manual screw drives, and for installation of the spent fuel assemblies in the area of the clamping prisms, there is a through axial cylindrical hole in the base with a diameter equal to the outer diameter of the jacket for spent fuel assemblies, and in the rotary plate there is an oval hole, which is It is located symmetrically to the center of rotation of the rotary plate with the distance between the centers of the oval equal to the center-to-center distance of the oppositely located peripheral cells of the SFA canister with the hole width at least 10 mm larger than the diameter of the canister cell for spent fuel assemblies.

A special case of the claimed invention is that a biological shielding is mounted on the rotary plate, which protects personnel from radiation exposure when aiming the gripper at the head (low-level) defective SFA and carrying out repair and locksmith work with it.

Installing the rotary plate coaxially on the ball bearings of the base plate allows you to manually rotate the rotary plate relative to the base plate with little effort.

The installation of the support on the swivel plate and its design make it possible to install two clamping devices for the following operations:

- clamping-unclamping of the spent fuel assemblies during the repair work of the low-level warhead;

- clamping-unclamping devices for internal guidance of the gripper using a TV camera and lighting in the storage cells of the BTB or ATO ships.

Manual screw drives make it possible to orient the positions of the clamping mechanisms with grips relative to the heads of defective spent fuel assemblies located in the canisters or storage cells, and to clamp-unclamp the clamping prisms of the clamping mechanisms.

The end stop position lock is a locking device for fixing a certain position of the rotary plate relative to the base plate.

A through axial cylindrical hole in the base plate with a diameter equal to the outer diameter of the SFA canister provides a grip on the spent fuel assembly head located in the canister or storage cell and subsequent transfer to the area of the clamping prisms of the clamping mechanisms.

An oval hole in the rotary plate with a distance between the centers of the oval equal to the distance of the oppositely located peripheral cells of the SFA canister, with the oval width at least 10 mm larger than the diameter of the spent fuel canister cell, allows you to target the SFA in the canister cell or storage cell and transfer the spent fuel assemblies to the zone clamping prisms of clamping mechanisms through the caliper. This design of the device ensures the handling of defective spent fuel assemblies using a loop gripper.

The essence of the invention is illustrated by the following graphical figures:

FIG. 1 - guiding clamping device, assembled;

FIG. 2 - support assembly;

FIG. 3 - supporting and rotary plates assembled;

FIG. 4 - installation of the guiding clamping device on the cell for working with the container;

FIG. 5 - the working position of the loop grip relative to the camera and the illuminating device.

The proposed guiding clamping device is a prefabricated structure consisting of a base plate 1 and a rotary plate 2 (Fig. 1). On the base plate 1, radially and vertically ball bearings 3 are mounted, on which a rotary plate 2 with biological shielding 4, a thrust end position lock 5 and a support 6 are mounted coaxially. clamping mechanism 7 mounted on the guide rails 8 with two manual screw drives 9. These drives provide an axial reciprocating movement (Figure 2).

Perpendicular to the axis of the support 6 in the grooves of the bodies of the clamping mechanisms 7, four clamping prisms 10 are installed, the compression-expansion of which is performed by four manual screw drives 11 (Fig. 2). The base plate 1 has a through axial cylindrical hole 12, the diameter of which is equal to the diameter of the jacket for spent fuel assemblies (Fig. 3).

The rotary plate 2 has an oval hole 13 located symmetrically to the center of rotation of the rotary plate 2 with the distance between the centers of the oval equal to the center-to-center distance of the opposite peripheral cells of the SFA canister with the opening 13 at least 10 mm wider than the diameter of the canister cell for spent fuel assemblies (Fig. 3).

On the rotary plate 2 through a threaded hole 14, a stop end position lock 5 (Fig. 1) is mounted.

Working with the clamping device when handling and re-covering with defective spent fuel assemblies is carried out in the following sequence.

Work on re-covering and handling defective spent fuel assemblies located in the storage cells of the FTB or BTB is carried out directly above the storage cell from which the spent fuel assemblies will be unloaded.

A typical funnel 16 is installed on the end part of the storage cell 15, on which NZU 17 is mounted (Fig. 4). Through the through axial cylindrical hole 12 and the oval hole 13, a cable with a TV camera 18 and illumination 19 (Fig. 5) is inserted into the inner cavity of the storage cell 15 (Fig. 5), and then a laser pointer is installed to pre-center the clamping mechanism through which the loop grip 20 will be inserted, for example, from Green Laser, and using a laser beam, alignment is performed using manual screw drives 9 and 11 and a circular movement of the rotary plate 2, followed by its locking with the position lock 5 relative to the base plate 1. For this, the position lock 5 is screwed into the threaded hole to stop against the end surface of the base plate 1.

Then, with four manual screw drives 11, the clamping prisms 10 are bred to the maximum extreme positions, through the formed openings between the clamping prisms 10, a typical loop grip 20 and a television camera 18 with an illuminating device 19 are inserted into the storage cell, which are then fixed in the clamping mechanisms 7, and using manual screw drives 9 are guided to the head of the unloaded defective SFA.

The head of the defective SFA is coupled with the working part of the loop gripper 20, the clamping prisms 10 are uncoupled and the gripper with the defective SFA is pulled (raised) from the storage cell so that the SFA head is above the clamping zone of the clamping prisms 10, which clamp the SFA.

They carry out repair and locksmith work to restore the spent fuel assemblies to their normal state. Then, a channel container 22 is installed on the upper end of the funnel 16, through the adapter 21, the SFA head is connected to the grip of the channel container 22, the clamping prisms 10 are uncoupled, and the spent fuel assemblies are loaded into the channel container 22 and then loaded into conditioned casks (Fig. .4).

Observation of the operations on aiming, engaging and unloading spent fuel assemblies from the storage cells of the BTB and PTB is carried out using a TV camera 18 and a lighting device 19 and a computer monitor (not shown in the Fig.).

Thus, the use of the proposed invention will solve the problem of radiation-safe unloading of defective spent fuel assemblies from storage cells, carry out repair and locksmith work to restore the spent fuel assemblies, contributes to further processing of spent fuel assemblies at the FSUE "PO Mayak" enterprise.

Claims (2)

1. A guiding clamping device containing a base plate and a rotary plate, ball bearings, characterized in that a rotary plate is placed on the ball bearings installed horizontally on the base plate, on which a thrust end position lock is installed, a support is mounted along the axis passing through the center of rotation of the pivot plate, while the support has two clamping mechanisms installed on the support guides with two manual screw drives, providing axial reciprocating movement along the support and perpendicular to the support axis; four clamping prisms are installed in the grooves of the bodies of the clamping mechanisms, the compression-expansion of which is performed by four manual screw drives, and in the base plate in the area of the clamping prisms there is a through axial cylindrical hole with a diameter equal to the outer diameter of the cover for spent fuel assemblies, and in the rotary plate - an oval a hole located symmetrically to the center of rotation of the rotary plate with a distance between the centers of the oval equal to the center-to-center distance of opposite peripheral cells of the cover for spent fuel assemblies with a hole width of at least 10 mm greater than the diameter of the cover cell for spent fuel assemblies. 2. The device according to claim 1, characterized in that a biological shielding is mounted on the rotary plate.

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