NPP decommissioning: a methodology to evaluate the gaseous pollution produced by hot cutting processes

A right methodology to determine preventively gaseous emissions arising from cutting process is essential to properly evaluate pollution in decommissioning a NPP. Said assessment can be related, in addition, to other diverse situations. In this paper, the estimated values of the pollution involved with plasma torch and oxyacetylene arc cutting processes are presented, in particular relating to the volatilized material, the volume of the powders per hour, and the concentration at the inhalation and in the environment. These processes have been carried out in an experimental campaign at the Caorso nuclear power plant (CaNPP), currently under dismantlement. The cut components are no activated pipes and plates - carbon steel with different surface treatments - exposed to the reactor coolant steam. Considerations are reported to evaluate the dilution between emissions and air at the inhalation and suggestions follow to safely perform the mentioned cutting procedures. Final considerations are also reported concerning the investigation of materials and components obtained from NPP decommissioning.