Amchitka Island, Alaska (KINY) No radioactive material has leaked from locations where the federal government conducted underground nuclear tests between 1965 and 1971.
The U.S. Department of Energy reported no subsurface migration of radioactive material and no excessive risk was found in samples tested in 2011.
Samples taken in 2016 upheld those earlier findings.
A 7.9 magnitude earthquake in 2014 did damage the caps on the three drilling mud pits but none of the diesel fuel filled mud was exposed.
Damage from the quake has not been repaired.
Three tests were conducted on Amchitka, about 1,340 miles southwest of Anchorage. The U.S. built a military base there during World War II.
The 2011 tests also gave seafood harvested in the area a clean bill of health.