Development of high-power density, high-speed scanning Laser decontamination technology, 2; Analytical evaluation of metal surface delamination

Kisohara, Naoyuki ; Aoyagi, Yuji*; Taguchi, Toshihiro  

Decontamination technologies, which remove radioactive substances from material surfaces, are significant to reduce radioactive wastes and recycle materials in decommissioning. Laser decontamination provides advantages such as remote processing and less produced secondary waste. The JAEA's experimental study has revealed that high-power density and high-speed Laser scanning irradiations achieve high decontamination efficiency by surface metal vaporization. The JAEA's computer code has been used to understand the phenomena induced by laser heating. This computer code has physical models including thermal conduction, metal melting, vaporization and radiation. The transient calculation is applied to simulate moving heat source by Laser scanning. The computer results have clarified surface melting, vaporization and solidification, explaining the relation between measured delamination depth and Laser irradiation conditions well.