High voltage direct current (HVDC) circuit breakers are a key technology to enable fault management for multi terminal DC (MTDC) networks. DC circuit breakers using superconductors for current limiting have been proposed previously and experimentally tested at low voltage levels. Superconductor materials are ideal for DC networks: they do not incur losses operating with pure DC current. This paper will focus on the interface between the superconductor element and the other elements of the breaker, i.e., the mechanical switch and semiconductor elements. A 10 kV DC circuit breaker will be developed based on the optimized interface and control strategy.