US detonated nuclear bomb to unlock gas; 213M cubic feet were produced, but the gas was radioactive

In 1967, the US detonated a 29-kiloton nuclear device 4,227 feet underground in New Mexico to boost natural gas production. Five tests produced 213 million cubic feet of gas, but it contained measurable radioactivity. The experiment was later ended, the site cleaned up, and radioactive contamination remains underground in the blast zone.