Enhanced CANDU 6 (EC6)

The Enhanced CANDU 6 is the Generation III version of the CANDU 6, developed by Candu Energy, a subsidiary of SNC-Lavalin (now AtkinsRéalis). It keeps the essentials of the line: 380 horizontal channels, natural uranium, heavy water as moderator and coolant, on-power refueling and two independent shutdown systems. What changes is the margin: 740 MWe gross, about 700 net, a design life of over 50 years against the original 30, a more robust containment, upgraded safety systems for severe accidents and open-top modular construction to shorten the build. It can operate flexibly down to 50% power.

The Canadian Nuclear Safety Commission completed its pre-project design review of the EC6 in 2013. It was proposed for Cernavodă 3 and 4 in Romania, whose construction was left half finished in the 1990s, and for a fourth plant in Argentina, where it was studied as a successor to Embalse before the project changed course. None has been built; Romania is now moving to complete Cernavodă 3 and 4 on the existing CANDU 6 structures.