In the 1940s and 1960s the United States carried out hundreds of nuclear tests, and the images of some of these experiments are well known and circulated for a long time on the Internet. However, most of the films filmed during rehearsals are still held in the custody of the US government, totally out of the public domain.
Reliving the past.
Of the total digitized tapes, 750 left the Top Secret classification and 63 were released on the laboratory channel on YouTube.
https://www.youtube.com/playlist?list=PLvGO_dWo8VfcmG166wKRy5z-GlJ_OQND5