Within the nuclear industry, the issue of radioactive waste management is of vital importance. Therefore, it is necessary to have methods and tools that allow for the treatment of contaminated materials without compromising worker health and that are economically viable. This work focuses on the synthesis of gels based on natural polysaccharides, which can form easily removable polymeric films and can decontaminate metal surfaces contaminated with radionuclides. Decontamination aims to remove or reduce contaminants (sometimes in combination with other hazardous materials) present on the surfaces of pipes, tools, glove boxes, radioactive cells, structures, and equipment such as rotors, motors, centrifuges, pumps, pump heads, columns, etc.
The use of polysaccharide-based decontamination gels is one of the currently available chemical decontamination treatment methods. It offers several advantages, such as lower operating costs during decontamination processes, lower risk for occupationally exposed personnel, no need to install a sealed system, and the gels being biodegradable. The use and development of decontamination gels contribute to reducing radioactive waste management costs and improving treatment.
Gels composed of different polysaccharides were tested to evaluate their decontamination properties on stainless steel surfaces and were evaluated by obtaining decontamination factors (DF). Gels containing 2.8% chitosan, 6% sodium alginate, 1% guar gum + 3% hydroxyethyl-cellulose, and 3% pectin were synthesized.
Decontamination tests on stainless steel specimens were positive, with high DF values obtained for various radionuclides, demonstrating the gels' ability to decontaminate metal surfaces and the high efficiency of the decontamination process. Radionuclides such as Nd-147 on stainless steel stood out, with very high Fd values. Similarly, high Fd values were obtained for Co-58 and Hf-181. The DF values in the decontamination process depend on the type of gel applied, the contaminating radionuclide, and the surface to be decontaminated.
