RU163907U1 - INSTALLATION OF OPENED FUEL FUEL STORAGE CASE - Google Patents

Abstract

The utility model relates to nuclear energy, in particular, to means for storing spent nuclear fuel elements of the RBMK-1000 reactor and is intended for use in a dry storage of spent nuclear fuel.

The installation for opening the spent nuclear fuel storage case contains a fixed shaft, a mechanism for installing and holding the cover of the case and a device for cutting the weld of the cover with the case of the case. The device for cutting the weld is equipped with a drive for turning the cutting tool around the pencil case.

The rotary drive of the cutting tool comprises a cutting tool mounted on an axis with the possibility of rotation around the pencil case and a rotation drive, on the output shaft of which a gear is engaged, which engages with a gear ring mounted on the device body. The rotation drive is made reversible with an adjustable speed.

The technical result is the creation of the possibility of opening a pencil case in a fixed shaft.

Description

The utility model relates to nuclear energy, in particular, to means for storing spent nuclear fuel elements of RBMK-1000 and VVER-1000 reactors and are intended for use in dry storage of spent nuclear fuel.

Spent nuclear fuel (SNF) from the RBMK-1000 reactor in the form of fuel rod bundles placed in ampoules at nuclear power plants is delivered to a dry storage in a protective container. Also, the VVER-1000 reactor SNF comes to the dry storage facility in the form of spent fuel assemblies (SFAs) from the wet storage facility. Further, in the chambers of the complete set of canisters (CCP) of the dry storage, the ampoules and SFAs are loaded into the cases of the canisters (see patents Nos. 2435239 and 2510087 IPC ⁷ G21C 19/06), placed in rotary shafts, and sealed by welding covers with cases. There, the canisters are filled through the valves with a nitrogen-helium mixture under excessive pressure, after which the tightness of the welded joint of the lid with the canister body is monitored by a helium leak detector. If helium leaks are detected, a second weld is applied to the joint, and in case of leakage of the weld after the second weld is applied, the canister must be opened to load SNF into another canister.

Known for the installation of opening canisters installed in the KKP (drawing 1694-12-0002 developed by the Central Design Bureau of Mechanical Engineering, St. Petersburg) is a stationary device that includes a rotary shaft with a rotation drive, a mechanism for installing and holding the canister cover, and a cutting device weld and penetration with transmissions connecting the drives to the executive bodies of the autopsy installation.

A pivot shaft designed to rotate a pencil case installed therein includes a pivot housing, clamping devices for centering and fixing the pencil case therein, a drive for transmitting rotation to the pivot housing, remote transmissions passing through the penetrations with the transmission and bevel gearboxes.

Also, near the rotary shaft, installations were installed for welding the case of the canister with its cover, filling the canister with a nitrogen-helium mixture and monitoring the tightness of the weld.

Currently, the mechanism for installing and holding the cover of the pencil case is made according to the patent No. 2518159, in accordance with which the lid is engaged by capturing the electromechanical non-copying bridge manipulator by a sleeve with an internal shoulder. The sleeve at the top is identical in shape and size to the ampoule cover. A stand is used to hold the lid.

A device for cutting a weld is a milling machine, designed according to the project 1694-31-0003 and installed permanently on a plate near the rotary shaft. The milling machine includes a stand consisting of two vertical rails along which the prefabricated housing moves with horizontal rails integrated into it.

Inside the guides are a shaft that transmits rotation to the spindle of the milling head, and screw pairs of vertical and horizontal movements of the milling head.

The actuators of the machine have the following movements:

- rotation of the spindle with the tool;

- horizontal movement of the milling head;

- vertical movement of the milling head.

To transfer movements to the actuators located in the control panel from the drives installed in the serviced zone, kinematic chains are assembled, consisting of distribution and bevel gears, shafts with articulated couplings passing through the penetrations in the protective walls with seals.

The drives are gearboxes with electromagnetic couplings, and the choice of movement is carried out by switching on the corresponding electromagnetic couplings.

A known installation of opening canisters works as follows.

The milling cutter with the help of the machine's actuating mechanisms, providing vertical and horizontal movement of the milling head, is located above the sheared weld. The body of the rotary shaft with a case installed in it is driven into rotation. The vertical movement of the milling head is driven by cutting the milling cutter into the weld and the base metal of the body and the canister cover. After several revolutions of the rotary shaft housing, the weld is cut off and the milling head is pulled to the side. Then, the lock opens and holds the canister cover installation and retention mechanism, the cover is removed from the canister case and the SNF is reloaded into another canister. The lid is reinstalled on the empty case of the case and the case is transported for decontamination. As practice has shown, the duration of cutting a weld with a milling machine is 6-8 hours.

The disadvantages of the known installation of opening canisters include the fact that during cutting of the weld, the rotary shaft cannot be used to load ampoules into canisters.

At the same time, there are fixed shafts in the KKP, which serve for temporary storage of a case not fully loaded with ampoules until the arrival of the next flight.

The utility model is aimed at obtaining a technical result, which consists in creating the possibility of opening a pencil case in a fixed shaft.

The specified technical result is achieved by the fact that in the autopsy installation, including the mechanism for installing and holding the cover of the pencil case and the device for cutting the weld, the opening canister is placed in a fixed shaft, and the device for cutting the weld is equipped with a drive for turning the cutting tool around the pencil case.

In the particular case of execution, the rotary drive of the cutting tool comprises a cutting tool mounted on an axis with a possibility of rotation around the pencil case and a rotation drive, on the output shaft of which a gear is engaged that engages with a gear ring mounted on the device body.

In another particular case of execution, the rotation drive is made reversible with an adjustable speed.

Placing the opened leakproof canister in a fixed shaft allows simultaneously with its opening to load ampoules from SNF into a canister installed in the rotary shaft, and thereby reduce the duration of ampoule overloading.

The inclusion in the device for cutting the weld seam of the drive turning the cutting tool around the canister allows for the cutting of the weld along the perimeter of the canister and the opening of the fixed canister in a fixed shaft.

The installation on the axis with the possibility of rotation around the pencil box of the cutting tool and the rotation drive, on the output shaft of which a gear is installed, which engages with a gear ring mounted on the device case, allows the gear to rotate when the gear rotates by rolling around the gear ring rotation and cutting tool around the pencil case, thereby creating the possibility of cutting the weld along the perimeter of the fixed pencil, installed in a fixed shaft.

Performing a reversible rotation drive allows, after a complete revolution of the cutting tool around the pencil case, to return the cutting tool to its original position for the next pass, avoiding twisting of the supply cables and sleeves.

The implementation of the rotation drive with an adjustable speed allows you to choose the optimal feed rate of the tool depending on the depth of cut

The drawing shows a General view of the installation in section.

The proposed installation of opening contains a fixed shaft 1, a mechanism for installing and holding the cover of the pencil case (not shown in the drawings) and a device 2 for cutting a leaky weld 3 connecting the cover 4 with the body 5 of the pencil case 6 installed in the fixed shaft 1. The device 2 contains a body 7 mounted by its flange 8 on the cover 4 and fixed on it. A gear ring 9 is attached to the housing 7. An axis 10 is installed along the central axis of the flange 8. A sleeve 11 is mounted rotatably on the axis 10, to which a reversible drive 12 is connected, on the output shaft of which a gear 13 is installed, which engages with the gear ring 9, and a cutting tool 14, which is used as a grinding machine 15 with a cutting wheel 16 and a casing 17 for removal of cutting products.

The proposed installation is equipped with a remote control and a power cable, a sleeve for suction of cutting products, as well as a sleeve for supplying compressed air (not shown in the drawings) when using a pneumatic grinder 15.

The proposed installation works as follows. The leaky case 6 is transferred to the fixed shaft 1, freeing the rotating shaft to continue overloading the spent fuel. The cutting device 2 is mounted on the cover 4 and fixed on it. The copy manipulator connects the grinding machine 15 to the hoses for supplying compressed air and suction of the cutting products, the reversing drive 12 to the supply cable and bringing the cutting wheel 16 to the weld 3. The compressed air is fed to the grinding machine 15 and the cutting wheel 16 is cut into the root of the weld 3 to the required depth. Turn on the reverse drive 12. When rotating, the gear 13, which is meshed with the ring gear 9, is rolled around it, turning the reversing drive 12 and the sleeve 15 attached to it around the axis 10. At the same time, the grinding machine 15 attached to the sleeve also rotates around the stationary case 3 by cutting the weld 3 along the perimeter of the can 6. Depending on the depth of the cutting wheel 16, the cutting of the weld 3 can be carried out in several passes with the return of the cutting wheel 16 to its original position using the direction of rotation of the reversible drive 12. After cutting the weld seam 3, turn off the reverse drive 12 and supply compressed air to the grinder 15, disconnect them from the compressed air supply and suction of cutting products and from the supply cable with the copy manipulator and remove the device 2 from the canister 6. Further, the mechanism for installing and holding the lid of the canister lid 4 can be removed from the housing, and the ampoules can be overloaded into another canister.

Claims (1)

An opening installation for a spent nuclear fuel storage case housed in a fixed shaft, comprising a mechanism for installing and holding a cover of a case and a device for cutting a weld, characterized in that the device for cutting a weld is provided with a drive for turning the cutting tool around the case.

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