Powerful nuclear "plugs" - sometimes 3 Hiroshima - we have enjoyed until 1979. And only once failed. In 1972 in Kharkov region failed to block the emergency gas blowout. The explosion was mysteriously left on the surface, forming a mushroom cloud. Although the charge was minimal - just a 4 kiloton. And laid deep - for more than two kilometers.
Total probability of failure in the Gulf of Mexico - 20 percent. Americans could take a chance. The chance of dying during the flight to the moon they were even higher.
Of course, we used a civilian nuclear program on the ground, the Americans as to the sea - under water where the ocean depth reaches 1500 meters.
But in principle there is no difference - you still need to drill a well at a distance from leaking. And it lowered the bomb. As in the movie "Armageddon" with Bruce Willis in the role of a driller. It is desirable that the calculations were done correctly. Such hope is: the U.S. is full of smart scientists and powerful computers. And Russia could have contributed. We still live peaceful nuclear demolition.
http://www.kp.ru/daily/24482/640124/