With global warming grabbing headlines, carbon-free nuclear power is gaining popularity—and with it, concerns over what to do with the spent uranium fuel. The largest long-term burial project, Yucca Mountain, has stalled, and even though uranium’s first trip through a reactor extracts only 5 percent of its energy, power plants in the U.S. don’t reprocess fuel. This is mainly because the most common form of uranium, an ion called uranyl, is extremely difficult to extract from the spent fuel rods. But a new Pac-Man-like molecule could change that.

The molecule, created by scientists at the University of Edinburgh in Scotland, is called a macrocycle. It looks like a set of jaws, and when it comes into contact with uranyl, it chomps down and engulfs most of the ion. This weakens uranyl’s structure, making it more likely to react with compounds that can easily be fished out of a solution. The scientists still have a few hurdles to clear before the Pac-Man molecules can be set loose. For instance, the macrocycle doesn’t work well in water or air. But researchers say the work shows that uranyl reprocessing isn’t the dead end it was once believed to be, and they hope it leads to a greener nuclear era.