Laser Cutting and Size Reduction
Category: Dismantlement > Non-Mechanical Cutting Equipment > Laser Cutting
Reference # : OST/TMS No 1477, DOE/EM-0612 Model No :
The Remote Laser-Cutting (RLC) size reduction system cuts metal equipment of almost any size and shape in a remote-handling, high-radiation environment. The technique is an adaptation of the commercial laser-cutting method commonly used in automotive manufacturing and other industrial applications. Laser cutting is performed by generating a laser beam in a water-cooled laser power unit, transmitting this beam through a C-2 fiber optic cable, and cutting with the beam using an end effector that incorporates a focusing optics package and an assist gas injection port.
Benefits
Easy to use and easily handled with the hot-cell manipulator, allowing for precise placement
Able to cut complex geometries, such as a pipe within a pipe, in a single pass
Able to cut material at the desired location, cut difficult geometries in a straightforward manner, and cut material in its current condition
Dirt, corrosion, material expansion, and surface contamination do not materially affect cutting rate
Does not emit dangerous levels of metal vapor
Limitations
The Pacific Norwest National Laboratory (PNNL) laser cutting end effector needs to be perfected for freehand use. Several improvements were proposed but were not implemented because of time and budget constraints. The simplest and most promising improvement would be to mount a positioning finger on the end effector so the manipulator
operator could touch the finger to the cutting target to establish standoff distance instead of judging
distance by eye alone. A focal length longer than 200 mm could also be tried because a longer focal
length results in a larger and less critical optimum standoff distance but a larger focused spot size. The
larger spot size would, however, reduce the energy density and thus decrease cutting rate and increase
kerf width.
Further testing is needed to confirm the PNNL conclusion that high-OH concentration cables suffer less
irradiation-induced darkening than low-OH concentration cables. Testing high-OH and low-OH cables
was limited to irradiating one sample of each cable type. Higher irradiation levels should also be tried, as well as irradiation during cutting instead of sequential irradiation and photobleaching.
The laser cutting speed for the Energy Technology Engineerin Center (ETEC) storage tubes could have been increased significantly by using a
higher laser power and an auto-focusing cutting head, coupled with some modifications to the tube holding device or system.
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close up of the size reduction machine and Laser Cutting
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