Development of the Level 2 PRA Standard

The process of creating a standard is a very challenging exercise. This is particularly true when the standard has to be sufficiently flexible so as to accommodate a wide range of tools, methods and user (both national and international) needs, while simultaneously ensuring the requirements are sufficiently clear such that they can be implemented consistently and produce a product that is expected to provide acceptable predictions of plant risk. This paper provides an overview of the Level 2 PRA standard, its philosophical construction, and the integration and inter-relationship of the standard with the existing Level 1/LERF PRA standard and the proposed Level 3 PRA standard.