Classification and ranking of fundamental phenomena for validation of ACR computer codes

The high level identification and ranking of governing phenomena for major plant accidents establishes the basis for the safety analysis computer code validation process. The identification and ranking of phenomena is based on a set of major accident categories and event sequences, the safety concerns associated with the phases of the accidents and the impact of the associated governing processes and phenomena on the identified safety concerns. This paper reviews the classification and ranking of fundamental physical phenomena that are relevant for code validation for ACR safety analysis applications. A summary of the process of identification and ranking of the phenomena for the ACR and its application to large LOCA events is presented in this paper. (author)