Analyzing Unprotected Transients in Metal Fuel Cores with the SAS4A Accident Analysis Code

摘要

In the search for new advanced reactor concepts with enhanced safety and economics, attention is now centered in the US on the development of Liquid Metal-Cooled Reactors (LMR) equipped with a metal fuel core. While metal fuel reactors present significant advantages over oxide fuel reactors during normal operation and protected transients, they also have desirable characteristics during low probability unprotected transients. The consequences of these transients are evaluated using the SAS4A code system sup 1 . The SAS4A code has been designed to simulate the events that occur in an LMR core during the initiating phase of a hypothetical severe unprotected accident such as the Transient Overpower (TOP) or loss of Flow (LOF) accidents. In order to adapt the SAS4A code to the analysis of metal fuel cores, new models have been developed, reflecting the special characteristics of these cores. This paper describes current SAS4A capabilities and emphasizes the influence of metal fuel characteristics on the whole core behavior during the accident. (ERA citation 13:036267)