The Joint Convention is the only international legally binding instrument to address the safety of spent fuel and radioactive waste management. Spent fuel – nuclear fuel that has been removed from a nuclear power or research reactor following irradiation – is a mixture of plutonium, uranium and radioactive waste materials that must be carefully managed. Aside from the operation of nuclear reactors, radioactive waste is generated from a range of applications of atomic energy, including the use of radioisotopes in medical, industrial, research and agricultural sectors. Twenty years ago, on 18 June 2001, the Joint Convention entered into force with 25 countries. Today, of the 173 IAEA Member States, 83 are party to the Convention.