Through a U.S. Department of Energy Technology Commercialization Fund project supported by the Office of Nuclear Energy, national lab and industry scientists will develop xenon- and krypton-trapping “nanocages” to improve nuclear power production and waste remediation

An illustration of individual atoms of three different noble gases—argon, krypton, and xenon—getting trapped in a 2-D array of nanosized “cages.” These porous frameworks have a hexagonal prism shape and are made of silicon and oxygen. Brookhaven Lab and industry partner Forge Nano will advance this technology for nuclear energy applications.

UPTON, NY—A research proposal submitted by the Center for Functional Nanomaterials (CFN) and Nuclear Science and Technology (NST) Department at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, with the startup Forge Nano as a partner, has been selected as a 2020 Technology Commercialization Fund (TCF) project. Of the 82 technologies selected from among more than 220 applications, three were developed at Brookhaven Lab. This TCF funding is the first to be awarded to the CFN, where the technology was developed.

The DOE Office of Technology Transitions manages the TCF program, which was created by the Energy Policy Act of 2005 to promote promising energy technologies developed at DOE national labs. Federal funding awarded through the TCF is matched with nonfederal contributions by private partners interested in commercializing the technology. The goal of the TCF is to advance the commercialization of these technologies and strengthen lab-private sector partnerships to deploy them to the marketplace.

The project that Brookhaven Lab and Forge Nano scientists will partner on is called “Maturation of Technology for Trapping Xenon and Krypton.”

Xenon (Xe) and krypton (Kr) are two noble gases produced during nuclear fission—a reaction in which the nucleus of an atom splits into two or more smaller, lighter nuclei—inside nuclear reactors. These gases can decrease the amount of energy extracted from a nuclear fuel source by increasing the pressure in the fuel rod (the sealed tubes that contain fissionable material) and reduce fuel rod lifetime. Moreover, radioactive isotopes of Xe and Kr can become trapped in unreacted fuel, which requires disposal. Therefore, capturing and removing Xe and Kr could improve the energy-generation efficiency of nuclear reactors and reduce radioactive waste.

For several years, scientists in the NST Department have been exploring various candidate materials—including microporous carbon and porous metal-organic frameworks—to absorb these fission gases, thereby reducing pressure buildup in fuel rods. Separately, scientists at the CFN have been developing 2-D porous, cage-like frameworks made of ultrathin—less than a single nanometer—inorganic silica (silicon and oxygen) and aluminosilicate (aluminum, silicon, and oxygen) films supported on metal surfaces. In 2017, they became the first team to trap a noble gas inside a 2-D porous structure at room temperature. Last year, they discovered the mechanism by which these “nanocages” trap and separate single atoms of argon (Ar), Kr, and Xe at room temperature. Following these studies, the CFN submitted an invention disclosure on the silicate materials for trapping gases (among other applications) to Brookhaven’s Intellectual Property Legal Group, which together with Brookhaven’s Office of Technology Transfer, helped the team explore promising applications and connected CFN and NST scientists.

“Trapping single atoms of noble gases at noncryogenic temperatures is extremely difficult and a relevant challenge for nuclear waste remediation, among other industrial applications,” said CFN Interface Science and Catalysis Group materials scientist Anibal Boscoboinik, who has been leading the work. “This difficulty is primarily due to the weak interaction of noble gases in their neutral state. The approach developed at the CFN enables trapping of the noble gas atoms in cages via ionization—converting them to electrically charged atoms, or ions—for a very brief time so they can enter the cages. Once they are inside, they go back to their neutral, stable state, but by that time they are already physically confined in the cages.”