Dry excimer laser cleaning applied to nuclear decontamination

Abstract

Excimer laser ablation is a very powerful tool of dry cleaning. This technique allows the removal or oxide or painting deposited on a material without any modifications of the chemical and physical properties of its surface. This method has been effectively used in many areas. In nuclear industry, there is a great interest to develop in developing an efficient dry decontamination process. A review of the main laser decontamination experiments performed in the world is presented. Our laser cleaning prototype based on excimer laser ablation process is described. This prototype has been tested in nuclear facilities. It is mainly composed of a XeCl laser, a bundle of fibers for beam transmission, optical systems, collection cell with filter for ablated particle recovery, computer control of cleaning efficiency and beam displacement. Different kinds of materials, which are representative of contamination usually found in nuclear field, have been irradiated. Decontamination factors (initial activity/residual activity) higher than 15 for fixed contamination and up to 100 for unfixed contamination have been obtained. These performances demonstrate that the laser-based technique is the most efficient one for dry and fast decontamination.