Crystals to save nuclear waste

In a world increasingly concerned about the environmental and geopolitical implications of using fossil fuels, nuclear power is attracting significant attention. As a sustainable clean energy source capable of generating electricity on a large scale without greenhouse gas emissions, it offers a promising solution to support society’s transition to a carbon-neutral future.

However, nuclear power production generates radioactive waste. Safe management of this waste is a critical challenge that must be overcome in order to gain public confidence in this transformative energy solution.

An innovative solution for nuclear waste management

A team of researchers fromUniversity of Houston developed an innovative solution for nuclear waste management: molecular crystals based on cyclotetrabenzylhydrazones. These crystals, from a major discovery the team made in 2015, are able to capture iodine—one of the most common radioactive fission products—in aqueous and organic solutions, as well as at the interface between the two.

“This last point is particularly important because capture of iodine at the interfaces can prevent the iodine from reaching and damaging the specialized coatings used in nuclear reactors and waste containment vessels.Ognjen Miljanic, professor of chemistry and corresponding author of the article detailing this discovery, noted in Ognjen Miljanic Cell Physical Science Reports.

These crystals exhibit an amazing iodine adsorption capacity, rivaling porous metal organic frameworks (MOFs) and covalent organic frameworks (COFs), previously considered to be the pinnacle of iodine adsorption materials.

Alexandra Robles’ role in discovery

Alexandra Robles, first author of the study and a former doctoral student who based her thesis on this research, was working with crystals in Miljanic’s lab when she made the discovery. His interest in a solution to nuclear waste led Robles to investigate the use of crystals to capture iodine.

“The iodine ended up capturing at the interface between the organic and aqueous layers, a phenomenon that has not been studied much.Professor Miljanić added, adding that this exceptional property offers an intrinsic advantage. “When the material is deposited between the organic layer and the aqueous layer, it essentially stops the transfer of iodine from one layer to the next“.

Benefits of the catch-and-release technique

Not only does this process maintain the integrity of reactor liners and improve containment, but captured iodine can also be transported from one site to another. “The idea here is to capture it in a place that is difficult to manage, and then release it in a place that is easier to manage.Professor Miljanic said.

The other advantage of the catch-and-release technique is that the crystals can be reused. “If the contaminant simply adheres to the reagent, the whole must be discarded, which increases waste and economic lossesHe explained.

Of course, all this extraordinary potential has not yet been tested in practical applications, which makes Ognjen Miljanic think about the next steps.

Molecules, crystals and octopuses

The team created these tiny organic molecules containing only carbon, hydrogen and oxygen atoms using commercially available chemicals.

Each crystal is a ring-like structure from which eight linear segments emerge, leading the research team to call it the “octopus.”

“They are easy to manufacture and can be produced on a large scale from relatively inexpensive materials without a special protective atmosphere.Professor Miljanic pointed out again.

He estimates that he can currently produce these crystals at a cost of about $1 per gram in an academic laboratory. In an industrial context, the researcher believes the cost would be much lower.

These hungry little crystals are very versatile and can pick up more than just iodine. The team used them to capture carbon dioxide, which would be another big step towards a cleaner, more sustainable world. In addition, the “octopus” molecules are closely related to those in materials used to manufacture lithium-ion batteries, opening the door to other energy opportunities.

“It’s a simple type of molecule that can do all kinds of different things depending on how it integrates with the rest of the given system.Professor Miljanic concluded.So we keep track of all those apps as well“.

He is excited about the many possibilities crystals offer and is passionate about exploring practical applications. His next goal is to find a partner who will help scientists explore different aspects of the work.

In the meantime, the researchers plan to continue to explore the kinetics and behavior of the crystal structures to further improve them.

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In short, the University of Houston team’s discovery could transform nuclear waste management. Capable of capturing radioactive iodine, these crystals can form an effective and economical solution. The possibility of reusing these crystals after iodine capture represents a major advance in reducing nuclear waste. Although the work is still in a preliminary stage, the prospects offered by this technology are very promising.

For a better understanding

Q: How does this new way of managing nuclear waste work?

A: This method is based on the use of molecular crystals that can capture radioactive iodine, which is a common fission product in nuclear waste.

Q: What are the advantages of this new method?

A: One of the main advantages of this method is that the crystals used to capture iodine can be reused, which could help reduce the amount of nuclear waste.

Q: What are the next steps for this research?

A: The researchers now hope to test this method in practical applications and explore other potential uses for the crystals, including carbon dioxide capture.

Caption: A team of researchers from the University of Houston has discovered molecular crystals that are able to capture iodine, one of the most common radioactive fission products. These versatile crystals can be used for nuclear waste management and other energy-related applications.

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