The Gentilly-2 CANDU pressurized heavy water reactor (PHWR) is owned and operated by Hydro-Québec. It has a gross output of 675 MWe. Gentilly-2 was one of the first 700 MWe class CANDU 6 plants to be built.
Its construction began in 1974, and it went into service in 1983.
Nuclear energy, generated by Gentilly 2, provides approximately 3 per cent of Québec's electricity, or enough to meet the needs of about 180,000 homes and businesses.
In addition to having one of the first CANDU 6 nuclear power plants, Hydro-Québec was the first utility to adopt MACSTOR™ technology for its Gentilly station. MACSTOR (Modular Air-Cooled STORage) provides above-ground dry storage for used nuclear fuel. Hydro-Québec's first MACSTOR unit was installed in 1995. Since then, another four storage units were installed, and an additional five are planned.
In the beginning of the 1980s, there was a major imbalance between the supply and demand of electricity, made even worse by the 1981-1982 recession. To limit the surplus of energy in the Québec electricity grid, the Gentilly 2 nuclear power plant operated at only 50 per cent of its rated generating capacity over long periods until 1987, when it began operating at full power.
The Gentilly-2 reactor was safely shut down in December 2012.