Researchers have discovered a new material that could be used to trap dangerous gases released during nuclear reprocessing and waste handling to make the procedures cheaper and safer.
The material, discovered by a team of scientists from the Swiss École Polytechnique Fédérale de Lausanne and the Pacific Northwest National Laboratory of the US Department of Energy, is a nano-porous crystal that can assemble itself into an ordered pre-determined structure.
Experiments have previously been conducted with this type of material to capture CO2 emissions, but the scientists found it can also absorb nuclear waste gases such as xenon and krypton.
These gases are released during nuclear reprocessing and usually escape from the facilities. The current methods of capturing them are costly and complicated and involve energy-intensive distillation at very low temperatures. The process is hazardous, as it can cause explosions.
The material, abbreviated to SBMOF-1, can capture both xenon and krypton at room temperature and can even cater for the different half-lives of the two compounds.
In an article published in the latest issue of the journal Nature Communications, the team described how they found the material scanning a massive database of 125,000 materials and running computer simulations to spot which materials have the ability to separate xenon from krypton in industrial conditions.
"This is a great example of computer-inspired material discovery," said materials scientist Praveen Thallapally of the Department of Energy's Pacific Northwest National Laboratory. "Usually the experimental results are more realistic than computational ones. This time, the computer modelling showed us something the experiments weren't telling us."
As xenon has a much shorter half-life than krypton - a month versus a decade - the scientists had to find a material that would be selective for both but would capture them separately. As xenon is used in commercial lighting, propulsion, imaging, anesthesia and insulation, it can also be sold back into the chemical market to offset costs.
The new material has pores so small that only a single molecule of gas can fit inside each pore.