What is a Safety Case?
The Office for Nuclear Regulation (ONR) is the regulatory body for all aspects of nuclear safety within the UK. The UK generally operates a goal-setting regime rather than the more prescriptive regimes applied in other countries such as France and the USA.
Defence in depth requires that multiple layers of defence are provided via engineered features and management arrangements for preventing failures, and if prevention fails, limiting the consequences and prevention of evolution of events to more serious conditions.
While the safety case is a mandatory regulatory requirement, its primary purpose is to enable
each licensee to satisfy itself that it has considered all potential risks associated with
the activities on its site, and has implemented suitable and sufficient measures to mitigate
the risk of radiological consequences to its staff and to the public to a level that is
As Low As Reasonably Practicable.