Critical knowledge
From NKM WIKIDOC
Definition
Critical knowledge is The minimum knowledge required for a nuclear organization to operate. The knowledge established in the context of a particular position that is deemed imperative for incumbents of the said position to possess before being allowed to perform associated duties and tasks independently.

Fig 1 Euler diagram of Knowledge base and its relationship to Nuclear knowledge and Critical knowledge
Description
The knowledge established in the context of a particular position that is deemed imperative for incumbents of the said position to possess before being allowed to perform associated duties and tasks independently. Source: Risk Management of Knowledge Loss in Nuclear Industry Organizations