This paper presents recent advances by an international team of five countries Canada, U.S., China, Slovenia and Romania on the development and scale-up of the copper chlorine (Cu-Cl) cycle for thermochemical hydrogen production using nuclear or solar energy. Electrochemical cell analysis and membrane characterization for the CuCl/HCl electrolysis process are presented. Constituent solubility in the ternary CuCl/HCl/H2O system and XRD measurements are reported in regards to the CuCl2 crystallization process. Materials corrosion in high temperature copper chloride salts and performance of coatings of reactor surface alloys are examined. Finally, system integration is examined, with respect to scale-up of unit operations, cascaded heat pumps for heat upgrading, and linkage of heat exchangers with solar and nuclear plants. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.