Five thousand miles west of Los Angeles and 500 miles north of the equator, on a far-flung spit of white coral sand in the central Pacific, a massive, aging and weathered concrete dome bobs up and down with the tide.
Here in the Marshall Islands, Runit Dome holds more than 3.1 million cubic feet — or 35 Olympic-sized swimming pools — of U.S.-produced radioactive soil and debris, including lethal amounts of plutonium. Nowhere else has the United States saddled another country with so much of its nuclear waste, a product of its Cold War atomic testing program.
Between 1946 and 1958, the United States detonated 67 nuclear bombs on, in and above the Marshall Islands — vaporizing whole islands, carving craters into its shallow lagoons and exiling hundreds of people from their homes.
U.S. authorities later cleaned up contaminated soil on Enewetak Atoll, where the United States not only detonated the bulk of its weapons tests but, as The Times has learned, also conducted a dozen biological weapons tests and dumped 130 tons of soil from an irradiated Nevada testing site. It then deposited the atoll’s most lethal debris and soil into the dome.