Laser Decontamination of Paint Coated Concrete in Nuclear Plants

Laser technology offers an efficient decontamination of surfaces contaminated by Polychlorinated Biphenyls (PCB). PCB is a component of protective coatings on concrete walls in NPP’s up to the 1980s-years. State of the art is a manual and mechanic ablation, which then poses danger of a secondary contamination and needs a second treatment in a hazardous waste incinerator. A 10 kW diode laser in continuous wave mode and wavelength of 915–1030 nm rises up the surface temperature for ablation of coatings and thermal decomposition in one process step. Meanwhile, decontamination rates of 6.345 m²/h have been operated using a laser spot of 45 × 10 mm². An experimental facility with a three-barrier-system to contain toxic material has been designed and constructed. First experimental investigations use epoxy wall coatings for an optimization of the process and to calculate a simulation of the ablation process. Further experimental investigations for ablation of PCB-coatings can be operated safely. A second development is an in-situ measurement system to detect the thermal decomposition of PCB by a laser induced fluorescence (LIF) system by the project partner TU Bergakademie Freiberg (TUBAF), Germany.