Device for repairing nuclear reactor fuel assembly

FIELD: nuclear power engineering; water-moderated and water-cooled reactors.

SUBSTANCE: proposed device designed for repairing faulty fuel assemblies where damaged and unsealed fuel elements are detected has gripping means for installing fuel element or displacer incorporating grip operating mechanism. The latter is made in the form of kinematically enclosed cable system whose cable is rigidly fixed with gripping means and sequentially engages upper fixed roller, upper movable roller, frictional hauling drum, intermediate roller, and lower fixed roller. Upper movable roller is secured on one end of rocker arm whose other end is joined with load; intermediate roller is disposed above frictional hauling drum and connected to force transducer. Such design of device makes it possible to reduce damage probability to unsealed fuel elements in the course of their extraction and installation, to reduce damage to cladding outer surfaces of new fuel elements or displacers, and to enhance nuclear fuel burnup.

EFFECT: reduced damage probability, enhanced yield of fuel assemblies upon replacement of unsealed fuel elements.

4 cl, 1 dwg

 

The technical field to which the invention relates.

The invention relates to nuclear technology and applies tools for recovery of fuel assemblies for light water nuclear reactors, which are damaged, in particular leaky fuel elements.

The level of technology

During operation of the fuel assemblies in the active zone of the nuclear reactor at conditions of elevated temperature, pressure and radiation likely to damage of fuel elements. A fuel Assembly with damaged fuel elements must be removed from service. When you do this you have two options: direct fuel Assembly for processing or replace a damaged fuel element for a new fuel element or install in its place the displacer. Obviously, the first way is not cheap, because the processing goes incompletely burnt nuclear fuel. So now to the fuel assemblies must meet the requirements for providing remote mounting and dismantling. For remote mounting and dismantling are special devices that allow you to replace damaged (leaking) fuel elements to return fuel assemblies in Akti the reduction zone of the reactor system.

A device for the Assembly of fuel assemblies containing an eccentric rotary Cam inserted into a cell of the spacer grid for unclamping spring petals, and a key retainer spring petals after they are wound rotary Cam (GB 1397969, G 21 21/00, 18.06.1975). The key, locked spring petals left on the spacer grid for the free passage of fuel elements. After installation of fuel elements in the fuel Assembly with the key removed from the lattice.

Also known Luggage for cutting and repair of fuel assemblies containing moving the camera crane, mine cutting, which is installed with the possibility of vertical movement tilter swivel case, and sawing machine with spindle (EN 2072569, G 21 21/00, 27.01.1997). The camera is equipped with a canister located in the case. In the case include a fuel Assembly, which is beyond repair, and replace the fuel elements. This camera is designed for repair of fuel assemblies channel uranium-graphite reactors and may not be used for repair of fuel assemblies for light water power reactors, particularly of the type VVER-1000.

The closest in technical essence and the achieved result to the described invention is a device for re the Ontario fuel Assembly of a nuclear reactor, containing the capture tool to remove a leaking fuel element and/or for installation in a fuel Assembly of a new fuel element or separator, provided with a drive capture (GB 2115599, G 21 21/00, 07.09.1983). The known device comprises a device for cutting welds with suction to collect fine particles. Removing the leaking fuel elements and the installation of new fuel elements or plungers produce one force actuator, which may cause damage to the fuel Assembly as a whole.

The invention

The present invention is to design and build a device to repair a fuel Assembly of a nuclear reactor with improved performance.

The solution of this task is possible obtain a technical result, namely, that reduces the probability of failure of leaking fuel elements in the process of their extraction, reduces damage to the outer surface of the shells of new fuel elements or plungers, increased burnup of nuclear fuel due to the increase of the yield of fuel assemblies after replacement of leaking fuel elements.

These technical results are achieved by the fact that in condition the device for repair fuel Assembly of a nuclear reactor, containing the capture tool to remove a leaking fuel element and/or for installation in a fuel Assembly of a new fuel element or separator, provided with a drive grip, wheel drive grip made in the form of kinematically closed cable system, the cable which is rigidly connected with the capture tool and consistently communicates with the upper fixed roller, the upper movable roller, a driving friction drum, the intermediate roller and the lower fixed roller and the movable roller mounted on one end of the rocker arm, the other end of which is connected to the load, and an intermediate roller is located above the driven friction drum and connected to the sensor effort.

A distinctive feature of the present invention is that the actuator grip is made in the form of a kinematically closed cable system, the cable which is rigidly connected with the capture tool. The cable also consistently communicates with the upper fixed roller, the upper movable roller, a driving friction drum, the intermediate roller and the lower fixed roller and the movable roller mounted on one end of the rocker arm, the other end of which is connected to the load, and an intermediate roller is located above the driven friction drum and connected to the sensor effort. The result is a constant tension cable systems with variable loads.

In addition, the capture tool made with the possibility of rotation of the fuel element or separator.

It is advisable to carry out the rotation of the friction drive drum due to the engine, kinematically connected to the friction drive drum through a reduction gear and a safety clutch.

Appropriate gear to do the worm.

List of figures

The drawing shows a kinematic diagram of the device for repair fuel Assembly of a nuclear reactor.

Information confirming the possibility of carrying out the invention

The device for repair of fuel assemblies includes a tool 1 capture to remove leaking fuel element and/or for installation in a fuel Assembly of a new fuel element 2 or of the displacer. The actuator grip is made in the form of a kinematically closed cable system, the cable 3 which is rigidly connected with the capture tool 1 and sequentially communicates with the upper fixed roller 4, the upper rolling roller 5, the friction drive drum 6, the intermediate roller 7 and the lower fixed roller 8. The upper movable roller 5 is fixed on one end of the rocker arm 9, the other end of which is connected to the load 10. An intermediate roller 7 is located above the friction drive drum 6 and is connected to the sensor efforts 11. Tool 1 capture, it is advisable to move through the guide rollers 12. The drive of the friction drum 6 is connected to the engine 13 by means of the worm gear 14 and a safety clutch 15.

Operates the device in the following way. During the rotation of the driven friction drum 3 is a vertical moving means 1 capture new fuel element 2 or of the displacer, which is installed in the fuel Assembly (not shown). The constant tension of the cable 3 is carried by the upper rolling roller 5 mounted on one end of the rocker arm 9. The other end of the rocker arm 9 is connected to the load 10, which provides a constant tension of the cable 3. Changing the length of the lever arm 9 and the weight of cargo 10, you can provide the option of changing the tension of the cable 3 in a wide range. The sensor 11 of the efforts connected with the intermediate roller 7, allows you to monitor the effort of installing a new fuel element or separator in the fuel Assembly.

The device in accordance with the present invention can be manufactured using known means.

1. The device for repair fuel Assembly of a nuclear reactor, steriade the capture tool to remove a leaking fuel element and/or for installation in a fuel Assembly of a new fuel element or displacer, equipped with a drive engagement, characterized in that the actuator grip is made in the form of a kinematically closed cable system, the cable which is rigidly connected with the capture tool and consistently communicates with the upper fixed roller, the upper movable roller, a driving friction drum, the intermediate roller and the lower fixed roller and the movable roller mounted on one end of the rocker arm, the other end of which is connected to the load, and an intermediate roller is located above the driven friction drum and connected to the sensor effort.

2. The device according to claim 1, characterized in that the capture tool made with the possibility of rotation of the fuel element or separator.

3. The device according to claim 1 or 2, characterized in that the equipped engine, kinematically connected with a driving friction drum through a reduction gear and a safety clutch.

4. The device according to claim 4, characterized in that the gear made of the worm.



 

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