B61 nuclear bomb

B61
B61 training unit intended for ground crew. It accurately replicates the shape and size of a "live" B61 (together with its safety/arming mechanisms) but contains only inert materials
Type	Nuclear bomb
Service history
Used by	United States
Production history
Designer	Los Alamos National Laboratory
Designed	1963
Manufacturer	Pantex Plant
Unit cost	$28 million (Mod 12)[1]
Produced	1968 (full production)
No. built	3,155
Variants	13
Specifications
Mass	715 pounds (324 kg)[2]
Length	141.6 inches (3.60 m)[2]
Diameter	13.3 inches (34 cm)[2]
Blast yield	Believed to be either 0.3–340 kt[3] or 0.3–400 kt[4] in the weapon's various mods.

The B61 nuclear bomb is the primary thermonuclear gravity bomb in the United States Enduring Stockpile following the end of the Cold War. It is a low-to-intermediate yield strategic and tactical nuclear weapon featuring a two-stage radiation implosion design.^[5]

The B61 is of the variable yield ("dial-a-yield" in informal military jargon) design with a yield of 0.3 to 340 kilotons in its various mods ("modifications"). It is a Full Fuzing Option (FUFO) weapon, meaning it is equipped with the full range of fuzing and delivery options, including air and ground burst fuzing, and free-fall, retarded free-fall and laydown delivery.^[2] It has a streamlined casing capable of withstanding supersonic flight and is 11 ft 8 in (3.56 m) long, with a diameter of about 13 inches (33 cm). The basic weight of the B-61 is about 700 pounds (320 kg), although the weights of individual weapons may vary depending on version and fuze/retardation configuration. As of 2020, the weapon was undergoing a 12th modification. According to the Federation of American Scientists in 2012, the roughly 400 B61-12s will each cost "more than its weight in gold" - $28 million apiece.^[6][1]