The Defense-in-Depth (DiD) concept is internationally applied successfully in the design and operation of nuclear power plants. In nuclear power, DiD is an international standard. It is based on a structure of several security levels which are independent of one another to reduce the probability of occurrence of unexpected events or damage. The principle is that in the case of a security level failure /non-availability, the next level becomes effective, so that the effects of events are minimized.
DiD uses among others the following principles:
The concept of the DiD, which has been successfully applied in nuclear technology for many years, can be used in all sectors which are subject to increased safety requirements and/or have an increased risk profile and thus achieve a significant improvement in the safety level.