Journal of Nuclear Fuel Cycle and Waste Technology

Metal surface decontamination characteristics were investigated by using a laser ablation method. A second harmonic generation of a Q-switched Nd:YAG laser with a wave length of 532 nm, a pulse energy of 150 mJ and a pulse width of 5 ns was employed to assess the decontamination performance for metal surfaces contaminated with CsNO3, Co(NH4)2(SO4)2, Eu2O3 and CeO2. The ablation behavior was investigated for the decontamination variables such as a number of laser shots, laser fluence and an irradiation angle. Their optimum values were found to be 8, 13.3 J/cm2 and 30o, respectively. The decontamination efficiency was different depending on the kinds of the contaminated ions, due to their different melting and boiling points and was in the order: CsNO3>Co(NH4)2(SO4)2>Eu2O3>CeO2. We also evaluated a correlation between the metal ablation thickness and the number of laser shots for the different laser fluences.

Keywords

Ablation decontamination,Q-switched Nd:YAG laser,Second harmonic generation,High radioactive facilities,Radioactive metal waste