Although its basic thermodynamic features were conceptualized several decades ago, component performance fell short of making the supercritical CO2 (S-CO2) power plants commercially competitive. In the late 1990s a CANES group revisited the situation in view of turbomachinery efficiency improvements and the development of compact and efficient printed circuit heat exchangers. Performance modeling showed that a recompression version of the cycle was now more efficient than Rankine steam cycles above about 450°C, and potentially of lower capital cost. This makes a modernized S-CO2 power plant attractive for a variety of advanced reactor types. The MIT CANES effort has helped encourage R&D organizations in several countries, including Sandia in the US, to undertake construction of demonstration units of this cycle.