Nuclear fission Mexico, which was the scientific hub for research on bomb development and design. Other sites, notably the Berkeley Radiation Laboratory and the Metallurgical Laboratory at the University of Chicago, played important contributing roles. Overall scientific direction of the project was managed by the physicist J. Robert Oppenheimer. In July 1945, the first atomic explosive device, dubbed "Trinity", was detonated in the New Mexico desert. It was fueled by plutonium created at Hanford. In August 1945, two more atomic devices – "Little Boy", a uranium-235 bomb, and "Fat Man", a plutonium bomb – were used against the Japanese cities of Hiroshima
B46 nuclear bomb was redesignated the B53 nuclear bomb and W53 warhead. 50 B53 bombs were in US inactive reserves from 1997 to 2011, though none were actively deployed during that period. B46 nuclear bomb The B46 nuclear bomb (or Mk-46) was an American high-yield thermonuclear bomb which was designed and tested in the late 1950s. It was never deployed. Though originally intended to be a production design, the B46 ended up being only an intermediate prototype which was test fired several times. These prototypes were known as TX-46 units (Test/Experimental). The B46 design roughly weighed 8,120 pounds and was about 37 inches