Investigation of specific applications of laser cutting for dismantling of nuclear power plants

The aim of this work, performed on an experimental basis in a frame of strict collaboration between industry (Fiat-CIEI and Fiat-CRF in Turin) and public research laboratories (ENEA-PAS-FIBI in Bologna, ENEA-PAS-ISP and ENEA-TIB-TECNLAS in Rome) and supported by a CEC contract, was to bring out the items for better evaluation of the laser beam application possibilities in dismantling nuclear power plants. The main topics of the research have been: (i) study and definition of the relevant basic parameters ruling the aerosol generation rate and behaviour in terms of physical and chemical characteristics. This work has been performed in a facility specifically designed for aerosol measurements and equipped with a 2kW laser source; (ii) study of the feasibility of local abatement of the aerosols produced and of the pressure drop in the HEPA filters; (iii) study of long-distance transmission of the laser beam power performed with a 5KW laser source with an evaluation of the power loss and beam characteristic modifications; (iv) study of laser beam technique application for dismantling the Garigliano power plant steam drum in order to better demonstrate the feasibility of the use of this technique. The research resulted in the conclusion that the laser beam is actually appropriate for long-distance dismantling of metal components. Although the main aspects of the laser cutting process have been examined, some problems remain to be investigated. This could be performed, after proper cost-benefit evaluation, during a future decommissioning programme