Safety and radiation protection requirements

The hazard potential of a nuclear installation in the process of decommissioning depends on the kind and level of its radioactive inventory and the fact that part of this inventory could be released during an incident. Removing the fuel elements of a nuclear power plant reduces the activity inventory to around one ten-thousandth of the original level, thus significantly lowering the hazard potential.

A range of technical and administrative measures ensure protection for operating staff, the population and the environment against harmful effects of ionising radiation, both during normal operation and in case of accidents and incidents. They include:

• confinement of the radioactive inventory in systems and rooms in order to prevent release and spread
• shielding measures to reduce exposure in the workplace
• individual protection measures for personnel, for example the requirement to wear special protective suits, gloves, overshoes and where necessary breathing masks
• training for plant personnel and external staff
• optimised ventilation at the plant and
• filtering exhaust air and treating waste water to minimise the volume of radioactive substances that may be discharged into the environment in a controlled way in accordance with the official licence.

There is also close monitoring of the technically unavoidable discharge of radionuclides with exhaust air and waste water. Values for these discharges are laid down in the licences. In practice, levels fall far short of these licence values during both operation and decommissioning. Further safety aspects cover occupational safety, accident prevention et cetera, which are relevant for every industrial installation.