A Green Beret HALO jumps with a 50 pound tactical nuke between his legs
The Special Atomic Demolition Munition (SADM), also known as the XM129 and XM159 Atomic Demolition Charges and the B54 bomb was a nuclear man-portable atomic demolition munition (ADM) system fielded by the US military from the 1960s to 1980s but never used in combat.
On December 27, 2018, the Green Bay Press-Gazette interviewed veteran Mark Bentley, who had trained for the Special Atomic Demolition Munition program to manually place and detonate the SADM. The report stated that he and other soldiers training for the program knew this was a suicide mission because either it would be unrealistic to outrun the timer on the bomb, or that soldiers would be obligated to secure the site before the timer went off.
However, employment manuals specifically describe the firing party and their guard retreating from the emplacement site, at which point security of the device is provided through a combination of passive security measures including concealment, camouflage, and the use of decoys; and by active security measures including booby traps, obstacles such as concertina wire and landmines, and long-range artillery fire. Further, the SADM included a Field Wire Remote Control System (FWRCS), a device that enabled the sending of safe/arm and firing signals to the weapon via a wire for safe remote detonation of the weapon.