Dual-Coolant Lead-Lithium (DCLL) blanket: status and R&D in the area of MHD thermofluids and fluid materials interaction

S. Smolentsev - M. Abdou

University of California, Los Angeles, USA

Abstract
The DCLL is an attractive breeding blanket concept that leads to a high-temperature (T ∼ 700\degC), high thermal efficiency (η > 40%) blanket system. In the DCLL, the eutectic alloy lead-lithium (PbLi) circulates slowly (V ∼  10 cm/s) for power conversion and tritium breeding, experiencing strong magnetohydrodynamic (MHD) interactions. The MHD effects are also expected to have a strong impact on heat and mass transfer processes in the blanket, including tritium transport and corrosion of structural and functional materials. The key element of the DCLL concept is a flow channel insert (FCI) that serves as an electrical and thermal insulator to reduce the MHD pressure drop and to decouple the temperature-limited steel structure from the flowing hot PbLi. The paper introduces the concept, reviews history of the development of the DCLL in the US and worldwide and then reviews the most important R& D results obtained in the US in the ITER DCLL TBM program (2005-2011) and more recently in the area of MHD thermofluids and fluid materials interaction, including experimental and computational studies of MHD PbLi flows and corrosion of reduced activation ferritic/martensitic (RAFM) steel in the PbLi in the presence of a magnetic field. Figs 6, Refs 25.