US's smallest nuke would be perfect to shut the well down...

As BP prepares to lower a four-story, 70-ton dome over the oil gusher under the Gulf of Mexico, the Russians — the world’s biggest oil producers — have some advice for their American counterparts: nuke it.

Komsomoloskaya Pravda, the best-selling Russian daily, reports that in Soviet times such leaks were plugged with controlled nuclear blasts underground. The idea is simple, KP writes: “the underground explosion moves the rock, presses on it, and, in essence, squeezes the well’s channel.”

Yes! It’s so simple, in fact, that the Soviet Union, a major oil exporter, used this method five times to deal with petrocalamities. The first happened in Uzbekistan, on September 30, 1966 with a blast 1.5 times the strength of the Hiroshima bomb and at a depth of 1.5 kilometers. KP also notes that subterranean nuclear blasts were used as much as 169 times in the Soviet Union to accomplish fairly mundane tasks like creating underground storage spaces for gas or building canals.

These kinds of surgical strikes to shut off underground leaks, however, were carried out only five times, with the last one occuring in 1979. And there was only one misfire, near Kharkov, Ukraine, where a nuclear blast was unable to stanch a gas leak.

Happily, with a track record like that, “the chances of failure in the Gulf of Mexico are 20%,” KP writes. “The Americans could certainly risk it.”
http://trueslant.com/juliaioffe/2010/05/04/nuke-that-slick/

In 1991, President George H.W. Bush announced his decision to retire artillery-fired atomic weapons in the U.S. stockpile. The President made his decision unilaterally, apart from any arms control agreement with the former Soviet Union. The weapons, including all W-79s, were returned to NNSA for dismantlement at the Pantex plant. Source