Laser cutter TWI (Great Abington, Cambridgeshire, England) has been recognized by the UK Nuclear Decommissioning Authority (NDA; Moor Row, Cumbria, England) with a prestigious award for introducing remote cutting technology to decommission radioactive metal storage containers. The remote cutting system, which uses the company’s laser cutting technology, is expected to bring savings to the UK worth hundreds of millions of pounds.
Related: Progress in the use of laser cutting for decommissioning
Magnox Ltd has a large number of radioactive metal storage containers, which have been used over many years for storing and moving fuel elements for the UK’s Magnox reactors. Currently, the cost of storing low- and intermediate-level nuclear waste is related to the volume of the parts. The estimated cost of storing one such container for its lifetime is £0.5 million. There are around 300 containers at Hinkley Point and upwards of 2000 at Sellafield.
Although laser cutting is a well-established method for precision cutting of metals, it has only recently been applied to decommissioning. Magnox Ltd wanted to investigate an approach for breaking down metal storage containers—also known as nuclear skips—which would result in a significant reduction in the amount of active material needing storage. Notably, radioactivity in these skips is restricted to within 1.5mm of the material surface.
TWI was able to demonstrate that by using robotics to address positioning tolerances, its remote one-pass laser cutting technology can be used to quickly and safely divide a Magnox nuclear skip into five pieces. From here, the pieces pass into a five-axis milling machine, their geometries are scanned, and 1.5mm is cut away from exposed surfaces.
The resulting active material forms a mass of just over 50kg, compared to the 450kg weight of an empty contaminated skip. The newly cut mass also has a high packing density, so the volume remaining in storage is significantly reduced. Remaining (non-active) steel can be melted and recycled.
The facility has been designed such that it can be remobilized on another nuclear site.
The NDA Supply Chain Awards took place on November 4, 2015, in Manchester, in front of 1800 guests. The Technology/Innovation Implementation Award recognizes both the innovation and collaboration required to take a technology/innovation through to successful deployment on a site. TWI accepted the award alongside Fanuc Robotics and Magnox Ltd.
For more information, please visit www.twi-global.com.