In 1969, after a long negotiation, the United Kingdom Atomic Energy Authority (UKAEA) signed a formal agreement to supply Pakistan with a nuclear fuel reprocessing plant capable of extracting of weapons-grade plutonium annually. PAEC selected a team five senior scientists, including geophysicist Dr. Ahsan Mubarak, who were sent to Sellafield to receive technical training. Later Mubarak's team advised the government not to acquire the whole reprocessing plant, only key parts important to building the weapons, while the plant would be built indigenously.