Plutonium is produced in conventional nuclear reactors. The plutonium can be treated as waste and disposed of. It can be extracted from the spent nuclear fuel and be used to create new mixed uranium/plutonium fuel. It can also be extracted, refined and used to produce nuclear weapons. Combined civilian and military stockpiles worldwide probably exceed five hundred tons. A nuclear warhead can be made with less than ten pounds of plutonium.
Research in the chemistry of plutonium is currently being conducted at Florida State University by Professor Thomas Albrecht-Schmitt. He and his team have been researching plutonium chemistry for decades. Last year, he received $10 million grant from the Department of Energy to form a new Energy Frontier Research Center at the University of Florida that will focus on accelerating scientific efforts to clean up nuclear waste.
One focus of Albrecht-Schmitt’s research was to see how plutonium behaved differently than lighter metals such as iron and nickel in compounds with organic materials. They are finding that plutonium does nor interact with other elements and form compounds in exactly the fashion that was assumed. It turned out that plutonium behaved more like lighter metals in a compound with organic materials that was previously understood.
They were expecting the chemistry of their new plutonium/organic compound to be very complicated but it turned out to be quite simple. They realized that they could probably make the same types of compounds with other heavy metals including uranium and berkelium. (Berkelium is a transuranic element with atomic number 97. Berkelium does not occur in nature. It was first produced in 1947 at the University of California at Berkeley by bombarding americium-241 with helium-4 nuclei for several hours in the 60-inch cyclotron.)
When Albrecht-Schmitt first saw the new compound, he suspected that something interesting had happened because of the color of the compound. Plutonium compounds often have wild bright colors like purples and pinks. The fact that the new compound was brown suggested that they were seeing a new phenomenon.
Light metals are used to form compounds with organic materials. These compounds often contain light metal positive ions which exchange electrons. This makes the light metals attractive for forming compounds with this exchange of electrons. It was an important breakthrough to find that plutonium could form similar compounds.
Albrecht-Schmitt said, "In order to develop materials that say trap plutonium, you first have to understand at the most basic level, the electronic properties of plutonium. 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."
Albrecht-Schmitt and his team have explored the chemistry of other heavy elements in the outer reaches of the periodic table such as californium. (Californium is a man-made transuranic element. Its symbol is Cf and it has an atomic number of 98. It was first produced 1950 at the University of California Radiation Laboratory in Berkeley, by bombarding curium with helium-4 ions.)
It is hoped that better understanding of the chemistry of plutonium will improve methods of environmental remediation from radioactive contamination.
