While many believe that nuclear is the most dangerous source of electricity, the designation actually belongs to major hydroelectric dams.
Japan’s ongoing disaster at the Fukushima nuclear plant, now in its agonizing third week, has led many to conclude that nuclear is the most dangerous way to generate electricity. Not so. Nuclear is not the most dangerous, not by a long shot. That distinction unambiguously belongs to large hydroelectric dams.
The most catastrophic dam failure in history occurred in China in 1975, with the near-simultaneous failures of the Banqiao and Shimantan dams. The “August 1975 disaster,” as the Chinese call the horrors associated with the dams’ collapse, drowned 26,000 people, according to the Chinese government. Another 200,000 lives were lost in its aftermath. Records from the days following the dams’ collapse describe the chaos:
“East of Xincai and Pingyu, the water is still rising at the rate of two centimetres an hour. Two million people across the district are trapped by the water…. In Runan, 100,000 who were initially submerged but somehow survived [by clinging to trees, rooftops, etc.] are still in the water. Forty thousand people have been rescued; 200,000 are sick with diarrhea and other related illnesses. There’s no medicine. In Shangcai, 300,000 people are marooned on the dam, on rooftops, and elsewhere. Twenty communes have been engulfed by flood waters. Many people haven’t eaten anything for days. In Shangcai, another 600,000 are surrounded by the flood.”
Four days later: “The disease morbidity rate has soared. According to incomplete statistics, 1.13 million people have contracted illnesses, including 80,000 in Runan and 250,000 in Pingyu; in Wangdui commune alone, 17,000 people out of a total population of 42,000 have fallen ill, and medical staff, despite their best efforts, can only treat 800 cases a day.”
In all, 11 million were affected by the disaster, which came of a severe storm and unprecedented rainfall, leading to flooding that overwhelmed the two dams. Shimantan was built to withstand a flood so rare that it would come but once every 500 years; Banqiao was built to withstand an even rarer event — a once-in-a-1,000-year flood. The flood that arrived in August of 1975 was a once-in-a-2,000-year flood.
When the dams failed, they unleashed a tsunami six meters high and 12 kilometres wide that inundated 29 counties and municipalities. The scale of the disaster compares to that of the earthquake and tsunami that hit Japan. It cannot compare to the consequences of the radiation leaks from Japan’s Fukushima reactors, which, though dangerous to nuclear workers, are likely to cause no casualties among the general population.
Neither can it compare to either of the two other serious nuclear accidents that have occurred, at Three Mile island, which led to no deaths, and at Chernobyl, where United Nations agencies such as the World Health Organization, the International Atomic Energy Agency, and the Scientific Committee on the Effects of Atomic Radiation have been steadily decreasing death estimates with the passage of time. Because the dead bodies have simply not materialized, the UN agencies now outright dismiss the very high estimates of death that came from organizations like Greenpeace, saying of them, “These claims are highly exaggerated.” The maximum number of deaths that the UN agencies estimated in 2005 was “a few per cent…. Such an increase could mean eventually up to several thousand fatal cancers.” Even here, the UN agencies expressed doubt that these predicted deaths could be substantiated. “An increase of this magnitude would be very difficult to detect, even with very careful long-term epidemiological studies
,” it reported. The difficulty stemmed from the theoretical model that the UN was using to project deaths — known as the “linear no threshold” model, it amounted to a guesstimate that even the scientists who uphold it acknowledge to be unproven and unprovable.
Three years later, the UN distanced itself even further
from claims that the Chernobyl accident could have killed many in the general population — the UN’s Scientific Committee on the Effects of Atomic Radiation found only 15 fatalities from thyroid cancers. “Among the general population, to date there has been no consistent evidence of any other health effect that can be attributed to radiation exposure,” it reported. Because the theoretical models diverged so much from reality, it decided to set them aside. “The committee has decided not to use models to project absolute numbers of effects in populations exposed to low doses because of unacceptable uncertainties in the predictions,” it stated.
While deaths from nuclear accidents are hard to find, those from dams are not. Italy lost 2,000 people in a 1963 dam failure, France 400 in a 1959 failure. Smaller dam failures have led to lower losses of life in the U.K., the United States and Germany. The future will likely make the hazards of dam building more evident still, particularly in China, the world’s most aggressive dam builder.
According to the Chinese government itself, some 37,000 dams — 40% of its total — are at risk. In the decade ending in 2008, 59 dams were breached either due to torrential rains or shoddy construction. In 2008, Sichuan, home to 90% of China’s dams, suffered a devastating earthquake that damaged some 1,800 dams and left 69 of them in danger of catastrophic collapse.
Near Sichuan, situated atop two fault lines and upstream of Wuhan, population 10 million, lies the Three Gorges Dam, the world’s largest. If the Three Gorges dam failed catastrophically, as dam experts fear it might, the tsunami that would be unleashed would precipitate the world’s largest man-made disaster, with a death toll in the millions.
Lawrence Solomon is executive director of Energy Probe
, an anti-nuclear organization, and the author of The Deniers.
The extent of damage wreaked by the 1975 floods was first revealed in the West by Dai Qing in her 1998 book, The River Dragon Has Come. To read more of her description, click here.
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