US will build its first new nuclear warhead in 40 years

w66 warhead sembled nuclear weapon, or a radioactive nuclear weapon component The Mk 11 RV containing a W66 warhead fell approximately 75 feet to the floor of the silo

warhead and in the W66 Sprint warhead A different primary with a different name is used in IHE B61 bomb mods and in the W81 and W85 warheads  w66 The Sprint was a two-stage, solid-fuel anti-ballistic missile , armed with a W66 enhanced-radiation thermonuclear warhead used by the United States