The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1946 by scientists, including some who worked on the Manhattan Project, to develop the first atomic bombs. The Federation of American Scientists states that it aims to reduce the amount of nuclear weapons that are in use, and prevent nuclear and radiological terrorism.
https://en.wikipedia.org/wiki/Federation_of_American_Scientists