New stage in the design of a Transmutation Advanced Device for Sustainable Energy Applications (TADSEA))

Transmutation Advanced Device for Sustainable Energy Applications (TADSEA) is a pebble-bed Accelerator Driven System (ADS) with a graphite-gas configuration, designed for nuclear waste transmutation and obtaining heat at very high temperatures to produce hydrogen. In this new stage in the design of TADSEA, it was proposed and modelled a new burn-up strategy, simulating a multi-pass scheme of the pebbles through the core. In order to obtain the axial density power distribution more uniform, for more realistic thermal-hydraulic calculations. In the neutronic calculations it was considered the double heterogeneity of the fuel, by means of a detailed geometry modelling. In previous thermal-hydraulic studies of the TADSEA using CFD code, the pebble-bed nuclear core was considered as a porous medium. In this paper, the heat transfer from the fuel elements to the coolant was analysed using a realistic approach in ANSYS CFX 14. The maximum heat transfer inside the spherical fuel elements with a body centered cubic (BCC) cell and the entire height of core was studied. During the steady state, critical elements don't reached the limit temperature value for this type of fuel. (author)