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 a group of scientists, some of whom had previously contributed to the development of nuclear weapons in the Manhattan Project. 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