Commissioned in 1978, the Unterweser NPP is a thermal power plant situated along the Unterweser River, ten kilometers south of Nordenham. Whereas conventional thermal power plants use boilers fired by fossil fuels, the Unterweser plant has a nuclear-powered steam generation system.

The reactors used for generating nuclear energy in Germany are light water reactors (LWRs), in which ordinary or 'light' water (H2O) serves both as a coolant and moderator. There are to types of LWR: boiling-water reactors (BWR) and pressurized-water reactors (PWR). The Unterweser station is powered by a PWR.