yes, the first tests, went on even after independance. The very first were open air. Then there was "burried" tests (not really underground: just a pile of sand moved over the bomb). One went real badly: the yield was "too good" for the crap over it, and it blasted through. The jargon in french for that is a "débourrage". A delegation of official including a minister watching the test from a mile away was sprayed with radioactive sand. He's still there to tell on TV though...

Pierre