Investigation of kinetics and mechanisms of metallic beryllium corrosion for the management of radioactive wastes

Activated beryllium wastes are produced by the nuclear industry and have to be managed as radioactive waste during decommissioning and dismantling of nuclear facilities. One potential approach to the management of these wastes is their encapsulation and stabilization in cementitious matrices. The main issue with this conditioning is aqueous corrosion, leading to the hydrogen production and potential crack formation leading to a loss of confinement. To evaluate the suitability of different cement formulations, such as Ordinary Portland Cement (OPC) or magnesium phosphate cement for encapsulation of metallic beryllium, the corrosion behaviour of beryllium metal was investigated in solutions with different pHs. In alkaline solutions representative of OPC pore fluids (i.e. NaOH solutions with pH between 12.5 and 14), corrosion rates increase drastically with increasing pH. Investigations of the surface of the corroded beryllium samples by scanning electron microscopy indicate that pitting corrosion is the main corrosion mechanism under these conditions.