By Michael B. Gerrad, The New York Times, December 3, 2014
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A concrete dome covers radioactive soil at Enewetak Atoll, Marshall Islands. Credit James P. Blair/National Geographic, via Getty Images.
THERE is no consistent air service to the coral atoll of Enewetak in the Marshall Islands, where the United States tested 67 nuclear weapons between 1946 and 1958. On my first trip to the capital, Majuro, in 2010, to study the danger posed there by the rising ocean, I managed to get on a special flight taking dignitaries to Enewetak for the dedication of a school. From there, I boarded a small boat to visit a nuclear waste dump that the world had all but forgotten.
The Marshall Islands are only about six feet above sea level. Its survival and that of other island nations are on the minds of negotiators gathering this week in Lima, Peru, for a United Nations climate change conference.
This place stands out for its misfortunes: ravaged first by radioactivity from tests conducted after World War II and, now, by the rising seas that threaten to swallow it.
When the boat reached a tiny island called Runit, we jumped out, crossed a narrow beach and walked through some shrub brush. A concrete dome about 350 feet across loomed ahead. I saw no signs, fences or guards. My guide walked up the shallow incline of the dome and stood on its top; impulsively I followed him. I wished I had brought a Geiger counter.
The United States had chosen this string of islands halfway between Hawaii and Australia for its nuclear tests; specifically the atolls of Bikini and Enewetak. Each is a thin broken circle of coral reefs surrounding a lagoon, the remnants of ancient volcanoes. In the 1970s the United States was thinking about granting independence to the country, which it did eventually, and was considering what to do about the mess the testing left behind.
Bikini was so radioactive that there was little hope of allowing its displaced population ever to return home. But the military studied how to clean up Enewetak so that at least some land could become habitable again. The Defense Department concluded that there was so much soil contaminated with cesium-137 and strontium-90 that the safest approach was to leave it alone and let it decay naturally. Both have half-lives of about 30 years.
But also left behind by the blasts was plutonium-239, which has a half-life of 24,000 years. With enough plutonium-239 in the right form, a bomb could be made. That is why the United States participated in a $150 million operation, completed in 2012, to secure and clean up the plutonium at a Soviet-era nuclear test site in Kazakhstan.
At Enewetak, the United States decided in the late 1970s to dump as much plutonium-contaminated soil as it could gather into a 33-foot-deep crater on Runit that had been carved out in 1958 by a bomb roughly the size of the one detonated over Hiroshima.
In addition to the contaminated soil, crews filled 437 plastic bags with plutonium chunks they had picked up from the ground, left behind when one bomb misfired. These also went into the crater, which was then covered with an 18-inch-thick concrete cap. Most of the rest of the radioactive waste, with too little plutonium to trouble with, was bulldozed into the lagoon, over the objections of the Environmental Protection Agency and the displaced people of Enewetak. American officials also chose to leave radiation on the land at levels far higher than would be allowed after a similar cleanup in the United States.
The cleanup was completed in 1980, and some of the residents of Enewetak, who had been forced out in 1946 to make way for the bombs, were allowed to return. About half the atoll was still uninhabitable, however, and most of the rest had lost its ability to grow food. Canned Spam became a staple.
Longevity was not among the design criteria for the Runit dome (unlike Yucca Mountain in Nevada, where, until recently, the federal government planned to deposit its spent nuclear fuel deep underground in facilities designed to be safe for at least one million years). In fact the dome does not meet American standards for landfills for household trash.
A task force of the federal government’s National Research Council warned in 1982 that the dome might be breached by a severe typhoon. But a 2013 report sponsored by the Department of Energy saw no reason to worry. “Catastrophic failure of the concrete dome,” it said, “and instantaneous release of all its contents into the lagoon will not necessarily lead to any significant change in the radiation dose delivered to the local resident population.”
The reason, according to the report, was that the radiation inside the dome was “dwarfed” by the radiation in the sediments in the lagoon. Thus a leak from the dome would be no added threat because it is dirtier on the outside than the inside. Plutonium isotopes recently discovered in the South China Sea have been traced to the Marshall Islands, some 2,800 miles away.
An inspection last year found that the dome was deteriorating, and the radioactive groundwater below rises and falls with the tides. Storms wash sand onto the dome; vines grow in the cracks.
As things now stand, the Runit dome is likely to be submerged by rising seas or torn apart by storms, releasing its radioactive poison into the ocean and compounding the legacy our advanced civilization has left to this tiny island nation.
Michael B. Gerrard, the director of the Sabin Center for Climate Change Law at Columbia, is the co-editor, with Gregory E. Wannier, of “Threatened Island Nations: Legal Implications of Rising Seas and a Changing Climate.”
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