Laser cutting hazards of nuclear infrastructure decommissioning and dismantling

Laser cutting technology to support dismantling and disposal of radioactive waste.

Our aim

The high temperatures of the laser process can cause volatile separation of metals and produce laser-generated aerosols that contain more nano-sized particles compared to other cutting methods. Current hazard controls require staff to package solid particulate waste from filters and clean the environment where aerosols are deposited. The generation and transportation mechanisms of these aerosols are not fully understood and the risk from the particulates is not controlled at source.

This research aims to develop methods for the assessment, control and capture of laser-generated aerosol hazards. The outcomes will include enhanced safety guidelines for laser use in hazardous environments, new techniques for analysing emissions and valuable data to support the nuclear decommissioning industry. 

Our research

The research focuses on multiple key aspects of laser fume and include:

  • The measurement of the particulate mass size distribution and concentration from laser cutting of stainless steel. To ensure accurate sampling, a two-stage sampling system was implemented to manage particle transport efficiently while minimising deposition losses. This system incorporated turbulent mixing for homogeneity, flow conditioning to eliminate bias and mechanisms to mitigate gravitational and inertial deposition. Adjustments to sampling dynamics, such as isokinetic or anisokinetic sampling, were made to optimise particle collection based on specific size ranges.
  • The study employs schlieren imaging in an idealised environment to examine gas dynamic interactions during laser cutting and explored how process parameters such as stand-off distance, nozzle type and gas supply pressure influenced aerosol formation. High-speed imaging of melt ejection was used to observe the effects of surface stagnation pressure on particle size and melt behaviour. Additionally, a comparison between reactive (air) and non-reactive (nitrogen) gases was conducted to analyse differences in melt ejection regimes.
  • An investigation of pre-filtering methods such as induced agglomeration, which could increase particle size and extend filter life cycles, with detailed analysis of nanoparticle particle concentrations, analysis of agglomeration and dilution effects and exploration of pre-filtering techniques, with further research into fume abatement strategies.

Our outcomes

Our publications include:

  • “Controlling nozzle and kerf gas dynamics to manage hazardous laser cutting fume” 10.2351/7.0000747
  • “Reducing environmental risks in laser cutting: a study of low-pressure gas dynamics" 10.2351/7.0001106

Our sponsors

  • The United Kingdom National Nuclear Laboratory
  • The UK Nuclear Decommissioning Authority (NDA) project “Bad Laser Cutting to Get Good Laser Fume”
  • Engineering and Physical Sciences Research Council (EPSRC) Industrial Case Award [EP/X524803/1] and National Nuclear User Facility
  • Laser Optical Engineering Ltd

Loughborough project team