Fizzle (nuclear explosion)

The cause(s) for the failure might be linked to improper design, poor construction, or lack of expertise.

[4] For practical purposes, a fizzle can still have considerable explosive yield when compared to conventional weapons.

In multistage fission-fusion weapons, full yield of the fission primary that fails to initiate fusion ignition in the fusion secondary (or produces only a small degree of fusion) is also considered a "fizzle", as the weapon failed to reach its design yield despite the fission primary working correctly.

One month after the September 11, 2001 attacks, a CIA informant known as "Dragonfire" reported that al-Qaeda had smuggled a low-yield nuclear weapon into New York City.

[11] Although the report was found to be false, concerns were expressed that even a "fizzle bomb" capable of yielding a fraction of the known 10-kiloton weapons could cause "horrific" consequences.