Study on Laser Decontamination Technology for Metal Scraps with Radioactively Contaminated Surfaces

Abstract

In order to apply the laser decontamination technology to the clearance or recycling of metal scraps with radioactively contaminated surfaces, this study builds a laser decontamination experimental setup based on the 350 W nanosecond pulsed fiber laser. Then, this study conducts a series of experiments for the key parameters of the laser ablation and decontamination technology, including laser power, pulse duration, frequency, line spacing and scanning speed. According to these experimental results, the rule and the optimum parameters corresponding to different decontamination depths for the laser decontamination technology are obtained. This study in turn conducts verification test of this technology by applying it to the storage rack baseplate of the control rod pool for a nuclear power plant (NPP). The test results show that after the laser decontamination technology is used and the decontamination depth reaches 10 μm, the contamination level of the surface radioactively contaminated by β rays of the sample is reduced to less than 0.8 Bq/cm2, and can meet the clearance level.