On March 1 1954, on Bikini Atoll, in the Marshall Islands, the US military detonated the world’s first lithium-deuteride hydrogen bomb, a thousand times more powerful than the Hiroshima and Nagasaki bombs. The radiation blew downwind, to the southeast, and irradiated the residents of Rongelap and Utirik atolls, and the crew of tuna boat Fukuryu Maru, “Lucky Dragon.”  

The islanders and fishing crew suffered radiation sickness, hair loss, and peeling skin. Crew member, Aikichi Kuboyama, died six months later in a Hiroshima hospital. Island children, suffered lifelong health effects, including cancers, and most died prematurely. The Lucky Dragon sailors were exposed to 3-5 sieverts of radiation.

One sievert will cause severe radiation sickness leading to cancer and death. Five sieverts will kill half those exposed within a month (like the workers who died at Chernobyl within the first few week). Ten sieverts will kill any human being. Hiroshima and Nagasaki victims received 150 Sieverts. Even microorganisms perished.

Castle Bravo Blast - Creative Commons

Castle Bravo nuclear weapons test on Bikini Atoll 

Today, inside the crippled Fukushima nuclear reactor-2, the melting core releases 530 sieverts per hour, enough to kill a human instantly and melt steel robotic equipment within two hours.