Regulatory oversight is an activity outside direct control of the management of the hazardous system. That fact does not mean that this activity would be unimportant. Instead the regulator
may be considered as an important stakeholder with whom safety can be discussed and evaluated. Already the requirement to present arguments and evidence that an acceptable safety has been
reached, initiates a second check of their validity. Trust is an important attribute in regulatory communication both with license holders and with the society. Guidance for assessing regulatory
effectiveness has been given by IAEA (2002) and OECD/NEA (2011).