High Quality Content by WIKIPEDIA articles! The Tube Alloys was a codename of the clandestine research and development programme, authorized by the Government of the United Kingdom with participation from Canada, aiming to develop atomic weapons for Great-Britain`s nuclear program during World War II. Starting with the Western Allies`s nuclear bomb project in 1942, the British efforts were kept in extremely high-level secrecy such that they had to be referred to by code even within the highest circles of government. At the end of World War II, the Tube Alloys came to refer specifically to the element plutonium, whose very existence was secret until its use in the atomic bombing of Nagasaki.