Original sentence: Tube Alloys was the code-name for the British nuclear weapon directorate during World War II, when the very possibility of nuclear weapons was kept at such a high level of secrecy that it had to be referred to by code even in the highest circles of government
Edited sentence: Tube Alloys was the code-name for the British nuclear weapon directorate during World War II, when the development of nuclear weapons was kept at such a high level of secrecy that it had to be referred to by code even in the highest circles of government