Transient analyses to support the definition of trade experiment start-up procedures

The TRADE experiment, where a TRIGA reactor in subcritical configuration is coupled with a proton accelerator (cyclotron) through a spallation target interface, is conceived to demonstrate the feasibility of the coupling of the different components of an ADS (accelerator, target and subcritical core) at a thermal power level able to trigger the reactivity thermal feedbacks. Among the main purposes of the TRADE experiments there is the investigation of the start-up and shutdown procedures, to be defined as much as possible according to the TRIGA-RC1 safety approach. In this paper a preliminary analysis of TRIGA transients induced by accidental jumps of the cyclotron proton beam current impinging on the target assuming different subcriticality levels of the core has been carried out by means of TIESTE-MINOSSE and PARCS/RELAP5 codes, both able to treat coupled neutron kinetic and thermal-hydraulics.