Radioactive waste

Civilisation produces a multitude of radioactive substances, the hazard potential of which requires elaborate safety systems. If further use of a radioactive substance is not possible or not desired, it will be defined as radioactive waste. A significant proportion of this waste is produced by the operation of nuclear power plants. Additional waste is produced in research reactors and scientific or technical facilities, and in small quantities in the medical field. Radioactive waste contains unstable atoms, i.e. atoms whose nuclei spontaneously disintegrate and emit ionising radiation.

To protect humans and the environment from the adverse effects of this radiation, it is necessary to shield direct radiation and to prevent the release of radioactive substances. As some of the isotopes are very long-lived, compliance with both of these requirements must be ensured over a long period of time. Shielding against direct radiation can be achieved by placing several hundred meters of rock between the radioactive material and the outside world, or by using massive casks and concrete walls.