Bugey Nuclear Power Station

Bugey Nuclear Power Station is EDF's four-reactor pressurised water plant at Saint-Vulbas in the Ain department of eastern France, on the right bank of the Rhone roughly 35 kilometres upstream of Lyon. The four active units, Bugey 2, 3, 4 and 5, each generate in the 880 to 910 megawatt range, giving the site a combined capacity of around 3,580 megawatts. A fifth, older reactor, Bugey 1, a gas-cooled unit that entered service in 1972, was permanently shut down in 1994 and remains under decommissioning.

The station was built during France's 1970s nuclear expansion: Bugey 2 and 3 entered commercial service in March 1979, Bugey 4 followed in July 1979 and Bugey 5 in January 1980, making Bugey one of the older stations in France's operating fleet.

Its Rhone-side siting is a structural feature of the site: units 2 and 3 draw direct river cooling while 4 and 5 use cooling towers, a distinction that shapes how each pair copes with hot, low-flow summers. Hot weather periodically forces the regulator ASNR to weigh environmental thermal-discharge limits against grid operator RTE's requests for continued output, a recurring seasonal tension for Rhone-cooled reactors rather than a one-off event.