RU2348084C1 - Device for withdrawal of spent fuel assemblies - Google Patents

Abstract

FIELD: physics, nuclear physics.

SUBSTANCE: invention is related to devices for withdrawal of spent fuel assemblies (SFA) of nuclear reactors from cooling pond into transport package container (TPC). Device comprises radiation-protection unit arranged in the form of refueling container with gate at the lower end. There is mechanical grip inside refueling container, which is arranged with the possibility of SFA displacement along axis. TPC comprises protective cover, and there is basket in the form of grid with cells installed inside. It also comprises guiding device for loading of SFA from collector to refueling container. It also comprises guiding device for loading of SFA from refueling container into TPC, and also weight-lifting mechanism. Inside refueling container there is guiding tube of square section installed coaxially to it. Cells of TPC grid have square section, and guiding device for loading of SFA into TPC is arranged in the form of two plates. Upper plate is conjugated with refueling container and is equipped with two openings arranged in plane that passes through axis of guiding tube. Lower plate is fixed on TPC and is equipped with two geometric templates of basket grid, every of which is arranged in the form of openings system located so that whenever axes of upper plate openings are matched with axes of pair of openings that imitate specified cell of TPC in every of template, axis and plane of refueling container guiding tube symmetry coincides with axis and plane of symmetry of corresponding TPC cell.

EFFECT: creation of safe device for withdrawal of spent fuel assemblies of nuclear reactors from cooling pond into transport package container.

5 cl, 4 dwg

Description

The present invention relates to devices for reloading spent fuel assemblies (SFA) of nuclear reactors, mainly research reactors of the IRT type (standard research reactor), from the holding pool to a transport packaging container (TUK).

A device is known for loading capsules with spent nuclear fuel into a container [RF patent No. 2066488, IPC G21C 19/0, publ. 1996.04.28]. The device comprises a transport pipe designed for overloading the capsule, a cargo rope of a crane mechanism with a grip fixed to it that interacts with the capsule, and a mechanism for holding the capsule from falling, including blocks and flexible couplings connected to the brake engaging mechanism that interacts with the end switches of the crane mechanism . The mechanism for keeping the capsule from falling includes a grip interacting with a sling device mounted on the upper end surface of the capsule.

The disadvantage of this device is that it is intended for transshipment of the capsule into a single container, thus, it cannot be used for transshipment of SFAs of square section into a multi-seat container.

For the prototype of the invention, a device was selected for loading SFAs into a multi-seat container [RF patent No. 2094863, IPC G21C 19/00, publ. 1997.10.27]. The device includes a radiation protective unit, a lifting mechanism, a pointing device with a receiving funnel located above the SFA cutting chamber, in which the SFA storage container is located. The radiation protection unit is equipped with grippers for their docking with the SFA and their loading into the container of the railway platform.

To load the radiation-protective SFA unit, the radiation-protective unit is installed by means of a lifting mechanism on the receiving funnel of the pointing device located above the SFA cutting chamber. The radiation-protective unit is guided by a pointing device to the SFA bundles located in the container storage tank of the cutting chamber. Then the grips of the radiation protective unit are pushed to dock them with the SFA and the SFA is lifted into the cavity of the radiation protective unit. The loaded radiation-shielding SFA unit is transported by means of a lifting mechanism and mounted on a receiving funnel of a pointing device located above the container of the railway platform. The radiation-guiding unit is guided by the pointing device onto the container. Then the radiation protective unit is lowered and joined with the container. At the same time, the SFA located on the capture below the others first gets into the cell of the container. The remaining SFAs are installed in the cells of the container, by means of captures, after the SFA is turned around the loaded cell. Then the captures are disconnected from the SFA and lifted into the cavity of the radiation-protective unit. The radiation protection unit is undocked with the container, and it is ready to load the next SFA.

The disadvantage of this device is that it is designed to overload assemblies of only circular cross-section.

The problem to which the invention is directed, is to provide a device for transferring spent fuel assemblies of square cross section from an accumulator in a nuclear reactor holding pool to a multi-seat transport packaging container with lattice cells having a square cross-section.

To solve the problem, the device for reloading spent fuel assemblies contains a radiation protective unit made in the form of a reloading container with a gate at the lower end, a mechanical gripper is placed inside the reloading container, made with the possibility of moving the spent fuel assemblies along the axis of the reloading container, transport and packaging container with a protective cover, inside of which there is a basket in the form of a lattice with cells for accommodating waste heat assembly, a guiding device for loading spent fuel assemblies from a storage device into a transfer container, a guiding device for loading spent fuel assemblies from a loading container into a transport and packaging container, and also a lifting mechanism, characterized in that a guide tube coaxially placed inside the loading container a square cross-section, the lattice cells of the transport and packaging container have a square cross-section, and the suggestive a device for loading spent fuel assemblies into a transport and packaging container is made in the form of two plates having openings in the middle part, the upper plate is paired with a reloading container and provided with two through holes made in a plane passing through the axis of the guide tube, the lower plate is paired with a transport -packaging container and is equipped with two geometric patterns of the basket lattice, which are made in the form of a system of holes placed so that when the axes of the holes are aligned, the top th plate with the axes of the pair of holes simulating predetermined lattice cell transport and packaging container in each of the templates, the axis and the plane of symmetry of the guide tube reloading container coincides with the axis of symmetry and the plane of the corresponding lattice transport and packaging device cell.

In a particular embodiment, two pins are fixed in the holes of the upper plate.

In another particular embodiment, two pins are installed in two holes of the templates that simulate a given lattice cell of the transport and packaging container.

In another particular embodiment, a gate is installed between the transport packaging container and the bottom plate of the pointing device, the movable protective flaps of which are made in the form of a parallelepiped made of a material that protects against ionizing radiation.

In another particular embodiment, the transport and packaging container is provided with a protective box for lifting and removing the protective cover.

The invention is illustrated by drawings.

Figure 1 presents a General view of the device in the loading position of the SFA from the reloading container in TUK,

figure 2 presents a top view of the upper and lower plates of the pointing device, as well as the basket TUK in the position when two pairs of holes of the upper and lower plates are aligned with pins,

figure 3 presents a device for centering SFAs when they are loaded into a transfer container from a storage tank container of the holding pool,

figure 4 presents a protective box for removing and installing the cover TUK.

Figure 1-4 shows the following positions: 1 - winch to move the mechanical gripper; 2 - mechanical gripper, which serves to engage the SFA in the holding pool, the placement of the SFA in the reloading container and install it in the TUK; 3 - a guide tube with a cross-section in the shape of a square mounted inside the transfer container; 4 - reloading container; 5 - gate of the transfer container; 6 - protection block reloading container; 7 - the mechanism for moving the gate of the reloading container, 8 - the case of the gate of the reloading container, 9 - the upper plate of the guiding device for loading the SFA from the reloading container into the TUK; 10 - the bottom plate of the pointing device for loading the SFA from the reloading container in the TUK; 11 - the mechanism for moving the gate valves TUK; 12 - gate valve housing TUK; 13 - gate valves TUK; 14 - grid basket TUK with cells; 15 - TUK; 16 - the mechanism for lifting the cover TUK; 17 - protective box; 18 - protective cover TUK; 19 - plate mounted above the container - storage pool storage; 20 - a guide tube with a cross-section in the form of a square, mounted in a plate above the container - storage tank storage pool for the orientation of the SFA; 21 - SFA; 22 - holes for unlocking the mechanical capture; 23 - geometric patterns of the lattice baskets of the lower plate, made in the form of a system of holes; 24 - holes of two geometric patterns of the lattice basket of the bottom plate; 25 - cell lattice basket TUK; 26 - pins of the upper (lower) plate for the orientation of the TUK with SFA along the axes of the cells of the TUK basket.

The device is a TUK 15 (see figure 1), inside which is placed the lattice of the basket 14 with cells 25 (see also figure 2). On top of the TUK, a gate is installed, consisting of a housing 12, movable flaps 13 made in the form of a parallelepiped made of a material that protects against ionizing radiation, and a mechanism for moving the flaps 11. The guidance device for loading the SFA 21 into the TUK is made in the form of two plates: top plate 9 and a bottom plate 10 having openings in the middle part. The upper plate is associated with a transfer container 4 and is equipped with two holes for orienting the transfer container with the SFA along the axes of the cells of the TUK basket. In the upper part of the reloading container, openings 22 are made with plugs for unlocking the mechanical gripper. The bottom plate is paired with the TUK. Two geometric patterns 23 of the basket lattice are formed in the lower plate, which are made in the form of a system of holes 24. Two pairs of holes of the upper and lower plates, combined with pins 26, orient the TUK with the SFA along the axes of the cells of the TUK basket. The upper plate is associated with a transfer container, inside of which a guide tube 3 is placed coaxially with it. The transfer container is provided with a mechanical gripper 2 with a winch 1. Between the transfer container and the induction plate there is a slide 5 consisting of a housing 8, a movement mechanism 7 and an ionizing radiation protection block 6. The TUK is equipped with a hollow protective box 17 (see also Fig. 4), inside of which is placed a protective cover 18 with a mechanism for lifting it 16. To arrange the orientation of the SFA in azimuth, a device is used in the holding pool the centering of the SFA (see also Fig. 3), including a plate 19 located above the container - the storage pool of the holding pool, equipped with a guide tube 20 with a square cross-section.

The proposed device operates as follows.

A guide pipe 20, having a square cross-section, is directed at the SFA 21 located in the storage pool storage so that the pipe profile coincides with the SFA profile. The transfer container 4 is transferred by a lifting mechanism to the container, the storage pool of the holding pool, and is mounted on the plate 19 of the centering device.

The guide tube 3, having a square cross-section and placed inside the body of the transfer container, is oriented along the guide tube, also having a square cross-section and installed in the plate of the SFA centering device in the storage tank container. Open the gate 5 of the reloading container, including the protection unit 6, the gate body 8 and the mechanism for moving the gate 7. Using a mechanical gripper 2, they engage with the SFA. The mechanical gripper is suspended on the cable of the transfer container with the possibility of vertical movement. When moving down, the gripping legs fold and penetrate into the SFA head, where again, under the influence of gravity, they straighten and abut against the internal walls of the SFA head. When the cable is moved up, the gripper legs abut the tides on the body of the SFA head and engage with the head of the SFA. Rotating the handle of the winch 1, the SFA is lifted into the transfer container, then the gate of the transfer container is closed.

The reloading container with a lifting mechanism is moved to the TUK 15, equipped with a basket 14 in the form of a lattice with cells 25 having a square cross-section for placement of SFA. A gate is installed on the TUK, consisting of a movement mechanism 11, the housing 12 and the gate leaves 13. To orient the SFA in azimuth relative to the cells of the TUK basket lattice, a guiding device is made in the form of two plates: the top plate 9 and the bottom plate 10.

The upper plate is mounted on the lower plate in the desired position according to the overload pattern so as to align with the pins 26 the axes of the two holes of the upper plate with the axes of the holes 24 in each of the geometric patterns 23 of the basket lattice of the lower plate.

A transfer container loaded with one SFA is installed on the guide plate, as a result of which the plane of symmetry of the transfer tube of the transfer container coincides with the plane of symmetry of the corresponding TUK cell.

Then, with the TUK gate open, using the winch 1, the SFA is lowered into one of the cells of the TUK basket lattice. Disengage the mechanical gripper with the SFA, draw it into the reloading container and close the TUK gate valves. To disengage the gripper from the SFA, it is mounted on a solid support — the cell lattice of the TUK basket, and then the gripper is moved down to weaken the cable. At the same time, the seizure, by its weight, removes the paws inward and at the same time includes the lock. When moving the grip up, the latch holds the tabs inside the grip, allowing the grip to exit the SFA. After uncoupling from the SFA, the gripper is lifted into the transfer container to the stop and the TUK gate valves are closed. Raise the container and lower the grip, and then turn off the latch. A mechanical grip is unlocked through one of the holes 22. Freed from the action of the latch, the claw paws under the influence of gravity again straighten.

The capture is ready to grip with the next SFA.

When the TUK is filled with SFAs, the protective box 17, equipped with the lifting mechanism 16 of the protective cover 18, is mounted on the gate, after removing the upper and lower plates, they are centered on the hole for the passage of the cover located in the protective box, and the TUK is closed with a cover, then the gate is removed with the protective boxing and disconnect the mechanism for lifting the cover TUK.

Thus, the proposed device allows you to reload the SFA square section from the storage pool in a transport packaging container.

Claims (5)

1. A device for reloading spent fuel assemblies, containing a radiation protective unit, made in the form of a reloading container with a gate at the lower end, a mechanical gripper is placed inside the reloading container, made with the possibility of moving the spent fuel assemblies along the axis of the reloading container, transport and packaging container with protective cover, inside of which there is a basket in the form of a lattice with cells for accommodating spent fuel assemblies, suggestive a property for loading spent fuel assemblies from a storage device into a transfer container, a guiding device for loading spent fuel assemblies from a transfer container into a transport packaging container, and also a lifting mechanism, characterized in that a guide tube with a cross section is placed inside the transfer container in the shape of a square, the lattice cells of the transport and packaging container have a cross-section in the shape of a square, and the pointing device for loading from worked fuel assemblies in the transport packaging container is made in the form of two plates having openings in the middle part, the upper plate is paired with a transfer container and provided with two holes made in a plane passing through the axis of the guide tube, the lower plate is paired with a transport and packaging container and equipped with two geometric patterns lattice baskets, which are made in the form of a system of holes arranged so that when combining the axes of the holes of the upper plate with the axes of a pair of holes, uyuschih predetermined lattice cell transport and packaging container in each of the templates, and the axis of the plane of symmetry of the guide pipe handling container coincides with the axis and a symmetry plane corresponding grid transport and packaging device cell. 2. The device for overload according to claim 1, characterized in that two pins are fixed in the holes of the upper plate. 3. The device for reloading according to claim 1, characterized in that two pins are installed in two holes of the templates that simulate a given lattice cell of the transport-packaging container. 4. The device for reloading according to claim 1, characterized in that between the transport and packaging container and the bottom plate of the pointing device, a gate is installed, the movable protective flaps of which are made in the form of a parallelepiped made of a material that protects against ionizing radiation. 5. The device for reloading according to claim 1, characterized in that the transport and packaging container is equipped with a protective box for lifting and removing the protective cover.

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