High Quality Content by WIKIPEDIA articles! The Advanced CANDU Reactor (ACR) is a Generation III+ nuclear reactor design and is a further development of existing CANDU reactors designed by Atomic Energy of Canada Limited. The ACR is a light-water-cooled reactor that incorporates features of both Pressurised Heavy Water Reactors (PHWR) and Advanced Pressurized Water Reactors (APWR) technologies. It uses a similar design concept to the Steam Generating Heavy Water Reactor (SGHWR).