The Zwentendorf Nuclear Power Plant was the first commercial nuclear plant for electric power generation built in Austria, of three nuclear plants originally envisioned. Construction of the plant at Zwentendorf was finished but the plant never entered service. The start-up of the Zwentendorf plant, as well as the construction of the other two plants, was prevented by a referendum on 5 November 1978, in which a narrow majority of 50.47% voted against the start-up.