RU2569336C1 - Pick-and-place device with transient unit for installation into and removal from nuclear reactor of core elements - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: pick-and-place complex includes a conveying unit, a tight container with biological protection, a guide transient pipe and a transient unit. Movement of core elements to the tight container is performed inside the guide transient pipe tightly installed on a handling seat in a small turning plate of the reactor and attached to the container through the transient unit installed in the turning ceiling panel of the above-reactor room. The container is provided with a catch moved by means of load-carrying and control chains of the catch. The guide transient pipe is provided with a casing pipe to control the catch and a lifting device of the transient unit.

EFFECT: reduction of radiation doses on the personnel.

3 dwg

Description

The invention relates to nuclear technology and can be used to install and remove core elements having dimensions not exceeding the dimensions of fuel assemblies from nuclear reactors with a liquid metal coolant, in particular with sodium.

A reloading device for installing and extracting elements of the core from a nuclear reactor is an integral element of the transport and technological system of the reactor, designed for handling in-reactor assemblies. Elements of the core that have dimensions that do not exceed the dimensions of the fuel assemblies include, in particular, fuel assemblies (FAs), control and protection working bodies, sleeves of experimental channels and working bodies of the control and protection system, side screen assemblies, isotopic assemblies and technological rods. The overload consists in removing from the reactor cooled by the sodium coolant elements of the active zone of the fuel assembly size and installing “fresh” in their place. Since the highest requirements for reliability and maintainability are imposed on transshipment equipment performing the unloading and transportation of spent nuclear fuel, as well as the loading of fresh nuclear fuel, the transshipment device should operate in such a way that, in case of any failure in any equipment, it is impossible to exclude a situation in which it is impossible it would be possible to complete the operation for reloading nuclear fuel or it would be impossible to return the device to its original position with safety. Since there is an over-reactor room of considerable height (6000 mm) between the central hall and the reactor, it is required to create an overload path in this room, which provides the necessary protective environment during overloading, eliminating the ignition of the sodium coolant.

Known reloading machine of a nuclear reactor (patent RU No. 2397555 C1, G21C 19/00, G21C 19/10, publ. 08/20/2010) containing a working rod, vertically mounted on a trolley, and a blasting mechanism with an actuator interacting with the working rod. The actuator is made in the form of electromechanical jacks with a rigid kinematic connection.

However, in this machine, due to the fact that the rod is lifted using a cable, the installation of fuel assemblies in the reactor becomes problematic because of the need to overcome the frictional force that arises when the assemblies are installed in the corresponding jacks of the reactor rotary plugs. In addition, this reloading machine does not create a path that allows overloading through the over-reactor room.

A known machine for reloading fuel assemblies of a nuclear reactor (patent RU No. 2236052 C2, G21C 19/10, G21C 19/18, G21C 19/19 publ. 09/10/2004) containing a telescopic rod with a swinging grip controlled by a cable drive. The swinging grip is controlled by the rope tension force. The completion of the operation for overloading the fuel assembly and disengaging from the fuel assembly upon failure of the gripper control body is ensured.

The disadvantage of this machine is the possibility of a fuel assembly dropping in the event of a capture failure and the inability to create an overload path in the over-reactor room.

A known loading and unloading machine (REM) (Dollezhal N.A., Emelyanov I.Ya. Channel nuclear power reactor, M., Atomizdat, 1980), which allows overloading a channel nuclear reactor at any power level, as well as after it is stopped and dampening. The main parts of the REM are: a crane, consisting of a bridge and a trolley that moves along the bridge; spacesuit; a container with movable biological protection, including a drive for moving and controlling the gripper and a gripper that is movable and controlled by two chains made of channel-shaped links with bushings and rollers in hinges; farm with technological equipment (pumps, bellows valves, valves, containers, compressed air cylinders), electrical equipment and instrumentation; two precision guidance systems; loops and controls.

REM also does not create a path allowing overload through the over-reactor room. In addition, REM captures controlled by chains have significant dimensions, which makes it impossible to use them in the confined arrangement of equipment on the rotary plugs of a nuclear reactor.

The closest in technical essence is a reloading machine for a fast neutron reactor (AS SU No. 397094 A, G21C 19/10, publ. 07/20/1971), containing a transport device, a sealed container, a cooling system of a fuel assembly during overload, a gate and a manipulating device made in the form of a rod of two coaxial pipes equipped with drives, one pipe of which is connected to the cooling system, and the other moves relative to the first and is equipped with a device for connecting to the fuel assembly.

The disadvantages of this reloading machine include:

- the need to use an extended rod of the manipulating device;

- the absence of a single channel that allows for overloading through the over-reactor room with safety;

- the possibility of mechanical deformation of overloaded products.

The invention is based on the task of developing the design of a reloading device, which allows, during transport and technological operations to reload elements of the core, to eliminate mechanical damage to overloaded elements, to provide reliable protection for personnel, to prevent unacceptable release of radioactivity, and to ensure fire and physical safety.

To solve this problem, a design of a reloading device with a transition unit for installing and extracting core elements from a nuclear reactor has been developed. The essence of the proposed technical solution lies in the fact that the transshipment device with the adapter block, containing the transport device and a sealed container with biological protection, it is proposed to additionally provide a guide adapter pipe and adapter block, which allow you to organize an overload path through the over-reactor room. The objective of the invention is solved in that the movement of the core elements into an airtight container is carried out inside the adapter transition pipe, hermetically mounted on the overload socket in the small rotary plate of the reactor and docked with the container through the transition block installed in the rotary plate of the over-reactor room. This technical solution allows to provide the necessary protective environment during overloading and eliminates the possibility of mechanical deformation of overloaded products. The guide adapter tube and the adapter block docked with it still perform the function of continuous biological protection along the entire height of the reactor chamber. In this case, the sealed container is equipped with a gripper that is moved by means of the carrier and control gripper chains, and the guide adapter pipe is equipped with a casing for controlling the gripper and a device for lifting the adapter block.

The technical result that can be obtained using the proposed invention is:

- the ability to overload the elements of the active zone in the normal mode from the "discharge socket" (permanently assigned cell);

- the possibility of overloading (if necessary) the elements of the active zone with the provision of fixation of neighboring elements;

- the possibility of overloading the elements of the active zone from the reactor through the over-reactor room;

- the ability to move the elements of the active zone inside the reloading device, excluding mechanical damage;

- reduction of dose loads for staff;

- improving the reliability and safety of work, including exclusion of falling onto the floor of the central assembly hall, as well as foreign objects and media into the reactor cavity.

The technical result is achieved by the fact that:

- the container is equipped with a gripper moved by means of a carrier and a control circuit, which allows the installation of reactor core elements in the reactor to overcome the friction forces arising in the coolant;

- the guide adapter tube sealed on the reactor rotary plate is docked with the adapter block, which creates a path for overloading the core elements in the over-reactor room with the function of continuous biological protection and allows overloading inside it while protecting core elements from mechanical damage;

- the guide adapter pipe is equipped with a removable casing pipe with a vertical displacement drive, which, if necessary, allows for the fixation of neighboring elements of the active zone.

The invention is illustrated by drawings of FIG. 1-3:

in FIG. 1 is a general view of the design of a reloading device with a transition block in its initial position;

in FIG. 2 - in the working position (the gripper is located on the assembly head in the active zone);

in FIG. 3 - remote element A in FIG. 2 (lower part of the grip structure).

In FIG. 1 shows the design of a reloading device with a transition block for installing and removing core elements from a nuclear reactor, which comprises: a transport device 1, a sealed container 2 with biological protection 3, a guide transition pipe 4 and a transition block 5.

The transport device 1 consists of a gantry crane electric self-propelled bridge 6 and a crane electric self-propelled trolley 7 and moves around the central hall. Bridge 6 is designed to move along the axis of the central hall and is equipped with a system of precise guidance to the specified coordinates. Power supply and control is carried out by a cable located in the canyon of the central hall. The trolley 7 is designed to move the airtight container 2 across the axis of the central hall and is also equipped with an accurate guidance system at the specified coordinates.

The sealed container 2 is placed on the trolley 7 of the transport device 1. The sealed container 2 is designed to ensure radiation and physical safety when removing, installing, transporting and storing overloaded core elements. Thermal and biological protection 3 of the airtight container 2 is provided by layer-by-layer installation of removable sheets of thermal insulation, neutron moderator and absorber sheets, which simplifies the installation process of the device, increases its maintainability and optimizes the mass of biological protection. The sealed container 2 contains a gate 8 for sealing the container and docking with the adapter block 5, the carrier 9 and the control 10 of the capture chain, the drive 11 of the carrier chain of the capture, the drive 12 of the control chain of the capture, chain receivers 13, the guide pipe 14, the drive 15 of the guide pipe, the capture 16 , drive 17 for turning the gripper, TV camera 18. The gripper 16, the movement of which in the guide tube 14 is limited by the upper end stops 19 and the lower stops “crackers” 20, includes a housing 21, a rod 22 with a locking sleeve 23 and tabs 24, a plug 25. Capture 16 move inside the guide conductive tube 14 by the actuator 11, the carrier capture circuit pushing the carrier capture circuit 9 and sprockets 26 and 27 of the carrier capture control circuits. The guide tube 14 is moved inside the container 2 through the rack and pinion using the drive tube 15. The control of the capture 16 is carried out by the drive 12 of the control circuit of the capture through the control circuit 10 of the capture. The opening of the capture 16 is carried out by lifting the rod 22 with the sleeve 23 using the control circuit 10 of the capture. When performing an operation to orient an element of the core, in particular a fuel assembly (hereinafter referred to as assembly 28), the gripper 16 has a fixed height position, i.e. is in the highest position, which eliminates the possibility of mechanical deformation of the overloaded products. Monitoring the position of the assembly 28 is carried out using three TV cameras 18 located in the lower part of the sealed container 2.

The guide adapter pipe 4 (Fig. 1) is designed to organize and ensure the tightness of the overload path 29 between the reactor and the upper floor of the central hall, which allows for radiation safety in the over-reactor space and the central hall during transshipment operations. The guide adapter pipe 4 mounted on the overload socket 30 in the small reactor rotary plate 31, which is located on the large reactor rotary plate 32, consists of the adapter guide body 33, the casing 34, which is removable, and the vertical casing pipe drive 35. Casing pipe 34 carry out and fixation of the neighboring six assemblies from twitching. The adapter transition pipe 4 also includes: a lifting device 36, which allows the adapter 5 to move when docked with an airtight container 2, a gate 37 that overlaps the passage section of the adapter pipe 4 when overloaded and locked, and a media replacement system 38. Forced cooling of exhaust elements the active zone is carried out when they are in their highest position due to purging by cooling argon of the autonomous gas circuit. In the case of de-energized lift drives when the spent core elements are in an intermediate position, the lifting device 36 is automatically disconnected from the drives to ensure spontaneous lowering of the core elements into the reactor cavity.

The adapter block 5 is removable, and it is installed in the technological hole of the small rotary plate 39 of the overlapping of the reactor room, which is located on the large rotary plate 40 of the overlapping of the reactor chamber. The adapter block 5 is designed to provide a tight dock with a sealed container 2.

The guide adapter pipe 4, joined through the adapter unit 5 with the guide pipe 14 of the sealed container 2, organizes the overload path 29, which provides the necessary protective medium during overload.

The proposed reloading device with a transition unit for installing and removing from the nuclear reactor the elements of the active zone operates as follows.

The initial state before the beginning of the overload of the elements of the active zone, in the particular case, the overload of the fuel assemblies (Fig. 1): the reactor is stopped and located, the reactor parameters for the overload mode are set.

To carry out the overload of the core elements, an overload path 29 is organized. A guide adapter pipe 4 is mounted on a small rotary plate 31 of the reactor above the overload socket 30. The protective reactor plug (not shown) is removed. Technological covers (not shown) are removed from the small pivot plate 39 of the overlap of the reactor chamber and the adapter pipe guide 4. Install the adapter block 5 on a small rotary plate 39 of the over-reactor room and connect to the guide adapter pipe 4. Using the transport device 1, guide the container 2 onto the adapter block 5, while the sliders 8 and 37 are closed, the gripper 16 and the guide pipe 14 of the sealed container 2 are in the highest position. By joint rotation of the small 31 and large 32 of the rotary plates of the reactor (the casing 34 is raised above the heads of the assemblies 28), as well as the rotation of the small 39 and large 40 of the rotary plates of the overreactor room, the axes of the assembly 28, transition guide tube 4 and adapter block 5 are combined forming a path of overload 29. By rotating the large 32 and small 31 rotary plates of the reactor, the channel in the small rotary plate 31 of the reactor is brought to the axis of the overloaded assembly 28. Next, the casing 34 by means of a vertical displacement drive 35 the heads of six assemblies lowering and fixing the heads of the six assemblies surrounding the unloaded assembly 28. Using the bridge 6 and the trolley 7, the axis of the sealed container 2 is aligned with the axis of the overload path 29. Then the sealed container 2 is joined to the guide adapter pipe 4. Docking is carried out by raising the adapter block 5 using a lifting device 36 of the guide adapter pipe 4, before pressing against the body of the sealed container 2. Replace the medium in the interscale space with argon using a medium replacement system 38.

Open the gate 8 of the sealed container 2, then the gate 37 of the guide adapter pipe 4 (Fig. 2). The gripper 16 is lowered on the pushing carrier chain 9 until it is seated on the stops "crackers" 20 of the guide pipe 14. The further lowering of the gripper 16 is carried out using the drive 15 of the guide pipe (rack and pinion). The sprockets 26 and 27 of the carrier 9 and the control 10 of the gripper circuits are disconnected from the drives, the vertical movement of the housing 21 of the gripper 16 in the guide tube 14 is limited by stops "crackers" 20 within 150 mm. The closed grip 16 is lowered until it contacts the assembly head 28. With the drive 35 for vertical movement of the casing, the casing 34 is lifted together with the rod 22 with the fixing sleeve 23 of the grip 16 until the tabs 24 of the rod 22 with the fork 25 open, while the grip 16 is “sagged” onto assembly head 28 due to free play. With the drive 35 for vertical movement of the casing pipe, the casing 34 is lowered all the way into the heads of neighboring assemblies, while simultaneously locking and fixing the tabs 24 of the grip 16. To fix the grip 16, a control preload of the rod 22 with the sleeve 23 of the drive 11 of the grip chain through the control circuit 10 of the grip is activated clutch drive torque limit. The drive 15 of the guide tube capture 16 with the assembly 28 is removed from the active zone until the guide tube 14 reaches the upper end stops 19. In this case, “dry” of the capture 16 and the connection of the sprockets 26 and 27 of the carrier 9 and the control 10 of the capture circuit to the drives. Further raising of the assembly 28 is carried out by the drive 11 of the gripping carrier circuit until it reaches its highest position. At this stage of the upgrade, the video cameras 18 state the assembly state and read the code for entering into the accounting system. The gates 8 are closed, then the gates 37 and the inter-crib space is purged with air with the discharge of media into the special ventilation system.

Using the lifting device 36 of the guide adapter pipe 4, lower the adapter block 5, unseal the container 2 and open it to the receiving equipment of the transport and technological part, where it is docked according to a scheme similar to the scheme of docking with the guide adapter pipe 4. The spent assembly 28 is lowered into receiving equipment of the transport and technological part using the capture 16. According to the layout of the receiving equipment according to the height of placement during lowering, it could s is enabled and the guide tube 14, e.g., during docking with the slots protective cells. The opening of the capture 16 is carried out by lifting the rod 22 with the sleeve 23 using the control circuit 10 of the capture.

The operation to orient the assembly 28 is performed when the gripper 16 is in its highest position by the drive 17 of the rotation of the gripper. Monitoring the position of the assembly 28 is carried out using three TV cameras 18 located in the lower part of the sealed container 2 so that the lower shank of the assembly 28 with the hexagon element of the cover is in the field of view. To enable video recording of the state of the assembly 28, the capture 16 is moved in two stages - first, on the carrier 9 and the control 10 of the capture chains, the capture 16 is lowered to fit the “crackers” 20 of the guide pipe 14 to the lower stops. The sprockets 26 and 27 of the chains are disconnected from the drives and deadlock stars. The drive 15 of the guide tube 14 is turned on, and the assembly 28 is further lowered to account for it being mounted on the assembly head 28; the gripper 16 is closed. The unwinding of the carrier 9 and the control 10 of the capture circuit is carried out under its own weight.

In the event of a blackout of the drives when the assembly 28 is in an intermediate position, it is provided that the lifting mechanisms are disconnected from the drives to ensure that the assembly 28 is spontaneously lowered into the reactor cavity to provide heat removal in the coolant medium.

The installation of "fresh" assemblies in the reactor is carried out in the reverse order. “Fresh” assemblies are kept in the drum of fresh assemblies before loading into the reactor. Download the “fresh” assembly from the drum of the fresh assemblies into the upper cavity of the container 2, close the gate 8. Using the transport device 1, move the sealed container 2 with the “fresh” assembly to the overload path 29. Using the lifting device 36 of the guide adapter tube 4, lift again the adapter block 5 before docking with the sealed container 2. Open the gate 37 of the guide adapter 4. Lower the casing 34 to fix the neighboring assemblies, then open the gate 8 of the airtight container 2. Lower the “fresh” Orc overloaded socket 30. Open the grip 16 on the head of "fresh" assembly. Raise the gripper 16 into the upper cavity of the airtight container 2. Close the gate 8 of the airtight container 2, then the gate 37 of the guide adapter tube 4, purge the interscreen space with air and discharge the medium into the special ventilation system. Disconnect the sealed container 2 by lowering the adapter block 5.

A reloading device with a transition block is inserted for installation and extraction of core elements from the nuclear reactor onto the next pair of fuel assemblies and overloading is performed.

The proposed device provides the required safety of work, radiation protection of personnel, as well as protection of personnel from temperature effects, while:

- creates a single sealed overload path, providing continuous biological protection and the necessary protective environment, eliminating the ignition of sodium coolant;

- unloading the irradiated elements of the core from the reactor into a sealed container is carried out inside the reloading device in an inert gas protective environment, excluding air entering the reactor through the over-reactor room.

Claims (1)

A transfer device with a transition block for installing and removing core elements from a nuclear reactor, comprising a transport device, an airtight container, a gate, characterized in that it further includes a guide transition tube and a transition block creating an overload path, wherein the guide transition tube is hermetically mounted on the swivel the reactor plate and is equipped with a lifting device for moving the adapter block, and a removable casing with a vertical displacement drive Nia, a transition block, providing the dock with the sealed container, is mounted in the rotary plate overlapping nadreaktornogo space, wherein the sealed container is equipped with a biological shielding and seizure, a carrier movable by means of the control and trapping circuits.

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