In 1973, the US set off three 33-kiloton nuclear devices in one Colorado well to crack gas-bearing rock; the cavities never connected and Project Plowshare was shut down

In 1973, the Rio Blanco project set off three nuclear explosions in Colorado, intending to create fractures in the rock to facilitate natural gas extraction. However, the anticipated connection between underground chambers failed to materialize, revealing only minimal interaction between the explosion sites. Eventually, due to various technical challenges and environmental concerns, the project was discontinued.
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