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Software architecture

The simulator developed in ASSAS will consist in several components.

TEAM_SUITE® software developed by Tecnatom will provide the HMI (Human-Machine Interface) through which the trainee and the instructor will be able to interact with the simulation. It will be possible to start, freeze, speed-up or slow-down the simulation, to visualise the results of the simulation, to withdraw data, to operate systems and to trigger malfunctions.

ASTEC scientific code developed by IRSN will simulate the progress of the severe accident and provide all calculation results to the HMI. ASTEC is composed of several modules corresponding to the different physical phenomena involved in a severe accident. During the ASSAS project, the performance of the different modules will be improved to allow the real-time execution of the simulator, for a realistic user experience. Some modules will be optimised thanks to efficient programming techniques, like parallelisation. Other modules may be partially or totally replaced by AI-based surrogate models. The different modules will work together to form a hydrid calculation tool, as shown in the diagramm below.

Other approaches developed during the project will try to replace ASTEC entirely with a machine-learning model. 

AI-based models will be trained on a reference database generated with ASTEC. For global surrogate models, which do not need to be interfaced with ASTEC, the American severe accident code Melcor can be used to produce training data. 

The optimisation of ASTEC’s modules and the use of AI may modify the calculation results. So, the simulator will be validated against reference codes to verify that the approximations remain acceptable.