It has now demonstrated a 5 kW fiber laser projector, configured rather like a rifle, that can be wielded by a single person.
To address the challenges encountered in decommissioning a nuclear facility, the UK-based firm TWI has since 2009 been developing laser tube-cutting methods for the UK’s Nuclear Decommissioning Authority. It has now demonstrated a 5 kW fiber laser projector, configured rather like a rifle, that can be wielded by a single person.
Metal pipework forms a surprisingly large proportion of the total volume of contaminated material that must be removed and treated when a nuclear facility is decommissioned. Laser cutting offers benefits for cutting of contaminated tubing, in that the cutting rate can be quite fast, no reaction forces result from the cutting process, and very little spread of contaminated material occurs. However, past laser cutting systems have generally been unwieldy, cumbersome, and used cutting geometries not well suited to the nuclear jungle of densely interwoven stainless steel tubing.
The TWI handheld laser cutting torch uses laser light generated by an IPG Photonics YLS-5000 5 kW ytterbium fiber laser (Larger fiber lasers are available, and could be used to enable more powerful laser torches). Ytterbium is the same laser element as is found in YAG lasers, which share the 1.06 micron laser wavelength. While this unit is rather large (1.4 m/55 in tall, 0.85 m/33 in on a side, and weighing in excess of half a ton), it can be connected to the torch through hundreds of meters of fiber, if required.
Laser cutting is a well established manufacturing process, but the cutting geometries encountered in demolition work are very different than the usual cutting on a flat table. In particular, very little study has been made of cutting tubing from a single side, rather than cutting by rotating the tube with a fixed laser directed at the desired kerf.