Radioactive sources are used in a wide variety of devices in medical, industrial, agricultural and research facilities worldwide. These sources emit high levels of ionising radiation, which can treat cancer, measure materials used in industry and sterilise food and medical appliances. Problems may arise when they are no longer needed, damaged, or decayed. The IAEA helps its Member States find long-term solutions for the safe and secure storage of disused sealed radioactive sources. Vilmos Friedrich is a radioactive waste expert in the IAEA Department of Nuclear Energy.