Decontamination of uranium-containing radioactive waste from stainless steel surfaces using NaOH-based molten salts

Herein, we report a new strategy for the rapid removal of uranium-containing contaminants from metal surfaces, and it relies on decontaminants made of NaOH-based molten salts. The addition of Na2CO3 and NaCl to NaOH exhibited superior decontamination performance, with a decontamination rate of 93.8% within 12 min, outdoing the performance of the single NaOH molten salt. The experimental results demonstrated that the synergistic effects between CO32- and Cl- promoted the corrosion efficiency of the molten salt on the substrate, which accelerated the decontamination rate. Additionally, benefiting from the optimization of the experimental conditions by the response surface method (RSM), the decontamination efficiency was improved to 94.9%. Notably, it also showed remarkable results in the decontamination of specimens containing different uranium oxides at low and high levels of radioactivity. This technology is promising for broadening the path in rapid decontamination of radioactive contaminants on metal surfaces.

Automated summary

In this study, a new strategy using NaOH-based molten salts as decontaminants was developed for the rapid removal of uranium-containing contaminants from metal surfaces. The addition of Na2CO3 and NaCl to NaOH greatly enhanced the decontamination performance, achieving a decontamination rate of 93.8% within 12 minutes, surpassing the performance of single NaOH molten salt. The synergistic effects of CO32- and Cl- promoted the corrosion efficiency, accelerating the decontamination rate. By optimizing the experimental conditions using the response surface method (RSM), the decontamination efficiency was further improved to 94.9%. Notably, this technology also showed remarkable results in decontaminating specimens with different uranium oxides at varying levels of radioactivity.