9. Is there any way to prevent Nuclear or Radiological Accident?

The primary means of accident prevention is “defence in depth”. Defence in depth is implemented primarily through a combined number of consecutive and independent levels of protection that would have to fail before harmful effects could be caused to people or to the environment. If one level of protection or barrier were to fail, the subsequent level or barrier would be available. When properly implemented, defence in depth ensures that no single technical, human or organisational failure could lead to harmful effects, and that the combinations of failures that could trigger significant harmful effects are of very low probability. The independent effectiveness of the different levels of defence is a requisite component of defence in depth.

Defence in depth is provided by an appropriate combination of:

  • An effective management system with a strong management commitment to safety and a strong safety culture.
  • Adequate site selection and the incorporation of good design and engineering features providing safety margins, diversity and redundancy, mainly by the use of:
  • Design, technology and materials of high quality and reliability;
  • Control, limiting and protection systems and surveillance features;
  • An appropriate combination of inherent and engineered safety features;
  • Comprehensive operational procedures and practices as well as accident management procedures.