Americium, what you need to know
What is Americium?
Americium is an artificial chemical element with the symbol Am and atomic number 95. It is a minor actinide produced in small quantities by fission reactions in nuclear reactors. Like all actinides, americium is radioactive.
Where does it come from?
Discovered in 1944 in the United States during experiments on plutonium, americium is created by neutron capture from plutonium in spent nuclear fuel and owes its name to the American continent.
What is it used for?
Americium-241 is used for applications related to its ionizing radiation, in environments where it is perfectly controlled. It was historically known for its (now obsolete) use in domestic smoke detectors. Here, it emits a flow of radiation that is used
in the devices to detect the presence of smoke particles in the air. It is also found in certain industrial applications, particularly for measuring the level of liquids or solid materials in tanks, and in soil exploration.
For some years now,
interest in americium-241 has focused on its use in powering electrical devices used in space. Due to its long half-life (430 years) and energy density, it performs well where solar and chemical energy have limitations. The heat it gives off warms
vital systems and can be converted into electricity (Seebeck thermoelectric effect).
Originally, plutonium-238 was predominantly used for its similar properties. However, due to limited global supply of plutonium and growing demand linked
to space programs, americium-241 offers a reliable and sustainable alternative.
Americium at Orano
Orano stores plutonium at its La Hague site for subsequent recycling in the manufacture of MOX fuel. A redissolution process is required to ensure the purity of the plutonium dioxide over time. This process separates out the americium-241 that has been
formed over the years through the natural decay of plutonium-241. Until now, this americium has been sent for vitrified waste disposition, but it could soon be recycled.
In 2024, a laboratory-scale pilot project demonstrated the validity of the process developed by Orano to extract this americium-241. Orano has therefore launched technical studies with a view to designing an industrial production facility at the La Hague site.