It was conducted on Yucca Flat at the Nevada Test Site like many other nuke tests in America. Area 8 hosted the "Baneberry" shot of Operation Emery on December 18, 1970.
The atomic test blast was a American test blast in Navada, USA. It was an utter cock-up!
The 10 kiloton warhead was test detonated 900 ft (270 m) below the surface, but its enormous energy cracked the soil in unexpected ways, causing a fissure near ground zero and the failure of the shaft and cap, thus letting the fall out vent out on to the test site 3.5 minuets after the blast.
The radioactive plume released 6.7 megacuries (250 PBq) of radioactive material, including 80 kCi (3.0 PBq) of iodine-131. Most of the fall out fell locally, then deposited heavily as radionuclide-laden snow in Lassen and Sierra counties in northeast California, and to lesser degrees in southern Idaho, northern Nevada and some eastern sections of Oregon and Washington states. The final radionuclides traveled across the US to Canada, the Gulf of Mexico and the Atlantic Ocean.
Some 86 workers at the site were exposed to low level radioactivity and 2 NTS workers acute myeloid leukemia, but the test was not blamed for there deaths despite of the American government's proven failure to do the test properly in the first place.