All practical steps must be taken to prevent and mitigate nuclear or radiological accidents. The most harmful consequences arising from facilities and activities have come from the loss of control over a nuclear reactor core, nuclear chain reaction, radioactive source or another source of radiation.
Consequently, to ensure that the likelihood of an accident having harmful consequences is extremely low, measures have to be taken in order to:
- Prevent the occurrence of failures or abnormal conditions (including security breaches) that could lead to such a loss of control;
- Prevent the escalation of any such failures or abnormal conditions that do occur;
- Prevent the loss of or the loss of control over a radioactive source or another source of radiation.