In 2013 the Bulgarian government announced plans to expand the existing nuclear power plant at Kozloduy.
The decision followed the cancellation of a proposed new plant at Belene.
In 2014 it was announced that US company Westinghouse Electric would develop the project, though development was delayed following negotiations over Westinghouse's role, with the Government wanting the company to commit to being an investor on the project.
In late 2015 it was announced that an unknown Chinese investment consortium may take a financing role on the deal.
The first four units of the power plant were constructed in the 1970s with Units 5 and 6 following in 1987 and 1991 respectively. Units 5 and 6 are the only ones still functional and are currently being upgraded.