Sellafield may have started as early as August 2004, and was categorised as a level 3 event on the International Nuclear Event Scale, resulting in fines. In February 2009, NuGeneration (NuGen), a consortium of GDF Suez, Iberdrola and Scottish and Southern Energy (SSE), announced plans to build a new nuclear power station of up to 3.6GW capacity at Sellafield. In October 2009, NuGen purchased an option to acquire land around Sellafield from the NDA for £70m. On 2 June 2010, Sellafield's gates were closed as a precaution in the wake of a deadly shooting spree and subsequent police manhunt, and the
Wylfa Nuclear Power Station nuclear station on a site adjacent to the old plant. An application to build two advanced boiling water reactors was submitted by Horizon Nuclear Power to the Office of Nuclear Regulation on 4 April 2017. Wylfa was the second nuclear power station to be built in Wales after Trawsfynydd in 1959. Following the closure of Trawsfynydd in 1991, Wylfa became Wales' only nuclear power station. Construction of Wylfa, which was undertaken by British Nuclear Design & Construction (BNDC), a consortium backed by English Electric, Babcock & Wilcox Ltd and Taylor Woodrow Construction, began in 1963. The reactors were supplied by