The first was the January 1950 confession by Klaus Fuchs that he had been passing atomic information to the Soviets. His confession led to immediate and sweeping classification of almost anything nuclear related. This included all fusion related work, as the previous fears about the possibility of using fusion as a neutron source to produce plutonium now seemed like a serious issue. The earlier plans to move the team from Imperial were put into effect immediately, with the AEI labs being set up at the former Aldermaston and opening in April. This lab soon became the Atomic Weapons Research Establishment.