Solvay and AREVA have signed an agreement to develop new applications for the use of thorium, an element that is abundantly present in the earth's crust and part of rare earth elements or uranium. The agreement aims to define the conditions ensuring the responsible management of thorium. It includes the deployment of a R and D program to study, amongst others, the use of thorium as a potential fuel in nuclear plants, as a complement to fuels using uranium and plutonium.

Through the extraction of rare earth elements from Solvay and AREVA's uranium extraction activities, both companies have inventories of thorium in France.