Raw materials from nuclear waste

Berlin, Germany (SPX) Jan 14, 2025
Is permanent storage the only strategy for dealing with nuclear waste? According to Prof. Kristina Kvashnina of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), there is another option. With support from a new EU-funded project, she aims to explore innovative ways to recycle elements from nuclear waste using advanced separation techniques. These methods could uncover valuable raw materials hidden in old nuclear fuels, not just for nuclear energy but for other industries as well. The initiative, titled "MaLaR - Novel 2D-3D Materials for Lanthanide Recovery from Nuclear Waste," has secured 2.3 million euros in funding for a three-year period. The international collaboration involves partners from Germany, France, Sweden, and Romania.

Lanthanides, the target of these recycling efforts, are a group of chemical elements that include certain rare earths. These materials play a critical role in numerous applications, such as screens, batteries, magnets, contrast agents, and biological probes. "Lanthanides are a very rare raw material, most of which comes from China. That's why we are trying to recycle this raw material from waste, even from nuclear waste," explained Kvashnina, the coordinator of the MaLaR project. She is part of HZDR's Institute of Resource Ecology and holds a professorship at Universite Grenoble Alpes in France.

To achieve effective recycling, the waste must first be separated. This task presents unique challenges due to the safety risks associated with radioactive elements and the similar chemical behaviors of the materials in nuclear waste. "That's why it's very difficult to find something which only causes a reaction in one element and not in others so that you can extract just the one," Kvashnina noted. Current separation methods often rely on hazardous chemicals, consume large amounts of energy, and produce additional waste.

Carbon materials as specific element scavengers

The MaLaR Consortium is working on a groundbreaking approach to address these challenges. The team's goal is to develop novel three-dimensional materials as tools for efficient, eco-friendly, and sustainable separation techniques. This method is intended for use not only with nuclear waste but also with industrial waste, including materials from radiomedical applications. Similar to existing separation processes, the researchers will employ the principle of sorption: specific radioactive elements in liquid nuclear waste adhere to the solid surface of a sorbent, allowing their separation from other waste components.

Recent studies indicate that graphene oxides - porous, carbon-based materials - can surpass the performance of leading industrial sorbents used for radionuclides. Furthermore, adjustments to the electronic structure of these materials have shown to further enhance their sorption efficiency. In the MaLaR project, Kvashnina and her collaborators plan to systematically investigate the chemical interactions involved and design new graphene oxide-based materials capable of selectively targeting specific elements.

Managing nuclear and industrial waste

"Our aim is to design a material with which we can initially extract individual elements from synthetic element mixtures. In the future, that could then be transferred to various applications," Kvashnina emphasized. While the project's three-year timeline allows only for an initial step toward recycling, success could pave the way for broader applications. The benefits would extend beyond recovering raw materials from nuclear and industrial waste to improving the safety of radioactive waste storage by enabling the separation and independent storage of isotopes with different lifetimes. The project's ultimate goal is to develop practical, market-ready technologies.

The MaLaR team benefits from its members' expertise in diverse fields, including 2D/3D materials development, radioactive element chemistry, and fundamental physics. The project also incorporates advanced in-situ techniques to investigate trace concentrations of lanthanides in radioactive materials.

"It'll be great to spend the next few years working in this team. We can combine fundamental insights from experiments with theoretical calculations and models as well as material characterization and development," said Kvashnina. She will also lead experiments at HZDR's Rossendorf Beamline (ROBL) at the European Synchrotron (ESRF) in Grenoble, where the new materials' chemical properties will be tested using high-intensity x-ray light.