Accident analysis of an experimental accelerator driven system

In order to demonstrate the safety of the 80 MWth LBE-cooled XADS design concept an extensive dynamic transient analysis was performed in the framework of the European research program PDS-XADS. A wide set of enveloping plant-specific transient initiators was selected to assess the intrinsic safety characteristics of the sub-critical core and to demonstrate the safety margins of the systems design. Some of them are characterized by a very low probability of occurrence (on the verge of credibility) in order to intentionally challenge the limits of the design. The transient analysis was performed by means of the neutronic thermal-hydraulic coupled code RELAP5/PARCS modified to analyse this kind of plants. This paper deals with the representative results of the transient analyse. It also provide a description of the numerical models developed for the XADS (code modifications, plant nodalization). (authors)