Thermo-hydraulic analysis of EU DEMO WCLL breeding blanket

In the frame of EUROfusion Work Package Breeding Blanket, thermal-hydraulic engineering analyses were carried out at ENEA Brasimone, in close cooperation with Sapienza University of Rome, to investigate thermal and fluid-dynamic behavior of the Water Cooled Lithium Lead Breeding Blanket, which is a candidate option for the European DEMO nuclear fusion reactor. The research activity focused on the equatorial elementary cell of an outboard segment with the aim of obtaining a temperature map of breeding blanket domains and to evaluate breeding zone and first wall systems cooling ability. A three-dimensional finite volume model of the breeding unit was developed, adopting the commercial CFD code ANSYS CFX 15.0. Steady state simulations were carried out considering a heat flux of 0.5 MW m−2, a radial power density distribution applied to all domains, and buoyancies forces activated in PbLi region. Results show that FW and BZ systems have good cooling efficiency, maintaining the maximum temperature in PbLi and solid structures well below 500 °C. The thermal-hydraulic results are discussed, highlighting open issues and suggesting pertinent modifications to DEMO WCLL coolant system layout aimed at optimizing the design.