ABSTRACT
This historical review of nuclear safety institutions and principles and of the incorporation of human factors in the production of assessments is ripe with lessons. In the span of fifty years, the role of the nuclear safety expert and the conditions under which they carry out their work have changed considerably. The physicist who was involved in the start-up and operation of new reactors gradually morphed into the expert statutorily separate from licensees, whose activity could be guided by a few key policy principles and governed by a set of procedures. Let us review three points that seem especially important:
• The resonance of defense in depth and the concept of barriers in nuclear safety policy principles. It bespeaks a view of safety as a set of systems that prevent accidents or mitigate their effects. An indication of this is found in the prevalent form of control employed by human factors experts. Viewed in terms of human and organizational factors, such an approach to safety might lead an expert to check for the presence of operating training systems or rules on the design of operating instructions. The control of safety by experts could thus come primarily under a form of bureaucratic control as defined by Ouchi (procedure-based control, cf. p. 20).
