Claim: The Operation Grommet was followed by the Operation Emery, another nuclear test series done in an underground shaft mostly for weapons development and safety experiment.
Evidence: The United States's Grommet nuclear test series was a group of 34 nuclear tests conducted in 1971–1972. underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
safety experiment underground shaft,
safety experiment underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft,
weapons development underground shaft, tunnel