Plutonium is used across the world in nuclear power plants, and while it generates lots of energy, its waste products are still not easy to deal with. Now, researchers argue that our ignorance may be making it ever more difficult.
Researchers at the University of Florida have completed an in-depth study of the chemical properties of plutonium and they argue that this heavy element behaves a lot more simply than we previously thought. They believe that plutonium reacts a bit like iron and nickel, which are much lighter. This might help us develop new ways to treat nuclear waste. The discovery is published in Nature Chemistry.
"What makes this discovery so interesting is that the material – rather than being really complicated and really exotic – is really, really simple," senior author Professor Thomas Albrecht-Schmitt said in a statement. "Your imagination goes wild, and you think 'Wow, I could make that class of compound with many other types of heavy elements.' I could use other heavy elements like uranium or maybe even berkelium."
The team discovered a type of electron transfer in a compound with two plutonium atoms. The electrons were moving back and forth between them, which they weren’t expecting to see in a such an element, although it’s very common in simpler atoms. The researchers had an unmistakable visual cue to suggest that something weird was going on. The compound had an unusual color: chocolate brown.
"Plutonium makes wild, vibrant colors," Albrecht-Schmitt added. "It can be purple, it can be these beautiful pinks. It can be this super dark black-blue. This compound was brown, like a beautiful brown chocolate bar. When we saw that color, we knew something was electronically unusual about it."
The electronic configuration of elements is key to their chemical interactions, and with plutonium's 94 electrons and several orbitals, it appears to be one of the most complex elements out there. But there are ways to make it behave and we need to focus on these approaches.
This new finding could allow for the development of a storage and waste management solution, which is currently beyond what we can do. And other radioactive elements could be dealt with in a similar matter. The research team has already looked into both californium and berkelium.
"In order to develop materials that say trap plutonium, you first have to understand at the most basic level, the electronic properties of plutonium," Professor Albrecht-Schmitt concluded. "So that means making very simple compounds, characterizing them in exquisite detail and understanding both experimentally and theoretically all of the properties you're observing."