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DISMANTLING TECHNIQUES

STATE OF THE ART ON DEVELOPMENT OF TECHNOLOGIES FOR DISMANTLING

OF NUCLEAR INSTALLATIONS IN RUSSIA

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Outline

• Techniques• Remote use of techniques for dismantling

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Plasma Arc Torch

• High cutting speed• Low driving force• Can be used in air and water

• Production of aerosols• Large quantity of secondary waste

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Electro-erosion fragmentation

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Electro-erosion fragmentation

• Very precise• Adequate for “chirurgical operations”

• Slow• Production of aerosols

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Gas Jet cutting

• easily rigged by manipulation devices • high production runs

• High quantities of secondary wasteFig. source: TMI

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Source: PRC Laser

Laser cuttingPrinciple

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Laser cutting

• Limited cutting thickness• Energy consuming• In the test phase

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Explosive cutting

Ref: http://www.pml.tno.nl/en/em/ap_cutting.html

Explosive cutting: Shape charges are used to cut through thick steel plates and cylinders

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Explosive cutting

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Choice of a dismantling techniqueTo be considered

• maturity of the technique• environment• complexity, thickness, etc.. Of material to

be dismantled• amount of generated secondary waste • cutting duration• operator's dose uptake • easiness of the operation• ….

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The remote-controlled complexes (RCC) for dismantling of nuclear

reactors of channel type

1 - Bearing truss; 2 - Skewing platform; 3 - Crosspiece; 4 - Hoist; 5 - Water seal; 6,12 - Safety compartments; 7 - Repair box; 8 - Handling box; 9-11 - Radiation-safety plates; 13 - Facility for sealing and decontaminating the primary packing of radioactive waste; 14 - Auxiliary safety container; 15 - Platform turning mechanism; 16 - Crosspiece lifting mechanism; 17 - Light-duty (tool) manipulator; 18 - Heavy-duty (load) manipulator

The general construction of the remote-control system for dismantling of reactor of the first power unit at the Beloyarsk NPP:

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Remote-controlled complexes for dismantling of nuclear reactors of vessel type

The dismantling system for mechanical cutting of the vessel of VVER-440 reactor:

1 - Supporting structure; 2 - Pull-rod; 3 - Tip; 4 - Ports; 5 - Platform; 6 - Turning gear; 7 - Rotary

table; 8 - Radial slots of rotary table; 9 - Rotary tool heads; 10 - Cutting tool; 11 - Grip; 12 - Hoist; 13 - Manipulator; 14 - Tool box; 15 - Handling facility; 16 - Platform hoisting mechanism; 17- Safety shell;

18 - Centering device