How can radioactive waste from nuclear-fuel reprocessing plants be banished? Nature Communications published research by scientists at the national level at EPFL and the U.S. on SBMOF-1, a material deemed a metal-organic framework.
This type of crystal absorbs radioactive waste better than current options.
Not only can the nanoporous crystal, which contains materials known to rid CO2 emissions and other contaminants, absorb waste better, it is a cheaper and safer option. This discovery is important for nuclear power plants that outdo fossil fuel plants in terms of cost but produce xenon and krypton that escape as dangerous gases.
It wasn’t easy for scientists to make the discovery as they had to sift through 125,000 candidates to find a certain molecular structure that can separate xenon and krypton at room temperature, as well as pose a lower risk of explosion. SBMOF-1 can also most likely be altered into an optimal crystal structure.
By self-assembly, the crystal structure would allow for greater gas storage separation, catalysis, optics, and chemical sensing. It is fascinating to know that SBMOF-1 has xenon/krypton selectivity under typical nuclear plant conditions as well as at room temperature.
This property allows scientists to capture both xenon and krypton separately despite preference for both. It was difficult for scientists in the past to find a suitable material, as xenon has a half-life of one month and krypton has a half-life of 10 years. By separating the components, xenon can be sold on the market as it is used in commercial lighting, propulsion, imaging, anesthesia, and even insulation.
SBMOF-1 has pore sizes similar to that of xenon atoms. The gas that is more attracted to the pore walls is separated from the other gas. In the future, it’s possible that SBMOF-1 will be used to capture other noble gases like radon.