Wednesday, Mar. 28, 1979. In the Three Mile Island nuclear power station in Harrisburg, Pennsylvania, the nightmare scenario of nuclear physicists was about to unfold. At four in the

morning, employees in the control room noticed the failure of a pump in the reactor's water cooling loop. When a bypass valve failed to trip, water stopped flowing to steam generators,

resulting in an emergency reactor shutdown. But the reactor continued to generate so-called decay heat. A relief valve opened automatically but then failed to close, allowing coolant to flow

out at a rate of one ton per minute. The control panel erroneously indicated that the cooling system was functioning normally, meaning technicians initially failed to recognize the problem.

Still, the series of events had a devastating effect: Not only was radioactivity released into the atmosphere, but contaminated coolant escaped into the nearby river. Cancer rates in the

local population later rose dramatically. In addition, large parts of the reactor and the power plant site were contaminated. The clean-up operation in Harrisburg took 14 years and cost more

than $1 billion. And the reactor ruins are radioactive to this day.

The case is instructive. It was the result of tiny construction errors and a small dose of human error. And now, as the world watches on in horror as the catastrophe in Fukushima continues

to unfold, the debate on the safety of nuclear power has been reignited. The area around Fukushima will likely remain contaminated for decades, if not centuries. And many are once again

wondering if the returns from nuclear technology justifies the risks. How can anything be considered under control which can so quickly mutate into an apocalypse?

Sadly, though, disasters like Three Mile Island and Fukushima are not as rare as one would hope. There have been plenty of atomic accidents resulting in significant radioactive leaks, spills

and explosions. And the Chernobly Exclusion Zone, for all the attention it gets, is far from the only nuclear no-go area on the planet. A look at some of the worst incidents is enough to

demonstrate just how high the price of nuclear energy and nuclear weapons truly is.

The Soviet authorities tried to cover up the incident for as long as possible. On the morning after the explosion, area residents were requested to stay indoors and to keep their windows

closed. One day later, all 50,000 residents of Pripyat were evacuated. They were told they would be able to return home after three days, but they were never allowed back.

It was weeks before the full extent of the disaster became known outside of the Soviet Union as radioactivity reached large parts of Europe. An exclusion zone was set up prohibiting entry

into an area 30 kilometers on all sides of the stricken reactor. Some say that as many as 110,000 people lost their lives with hundreds of thousands more still suffering from the effects of

the radiation, but other estimates are much lower. The International Atomic Energy Agency (IAEA) said in 2006 that fewer than 50 people died from initial exposure to radiation from the

reactor. At the scene of the accident, radiation exposure is still 700 times higher than permissible levels, and Pripyat remains uninhabitable.

But just 40 years later, massive problems with the site have become apparent. Despite assurances to the contrary, 12,000 liters of water are leaking into the site each day, rusting the drums

and resulting in a release of radioactivity. As yet, there is no proposal for what to do with the resulting sludge nor is there a plan in place for solving the Asse problem. Many of the

waste drums were simply piled up, instead of neatly stacked. It is impossible to get close enough to begin a clean up program.

Fifty-two buildings at Hanford remain contaminated to this day, and 240 square miles are uninhabitable due to the radioactivity that has seeped into the soil and ground water: uranium,

cesium, strontium, plutonium and other deadly radio-nuclides. Altogether, more than 204,000 cubic meters of highly radioactive waste remain on site -- two-thirds of the total for the entire

US. In one area, discharges of more than 216 million liters of radioactive, liquid waste and cooling water have flowed out of leaky tanks. More than 100,000 spent fuel rods -- 2,300 tons of

them -- still sit in leaky basins close to the Columbia River.

The plant is also notorious for the so-called "Green Run" -- the deliberate release of a highly radioactive cloud from the T-plant, the world's largest plutonium factory at the time. The

radiation was almost 1,000 times worse than that released during the 1979 meltdown at Three Mile Island in Pennsylvania, the worst nuclear accident in American history. Fallout from the

experiment drifted all the way to California. People wondered why they suddenly got sick. Studies would eventually show that some babies at Hanford were radiated twice as much as the

children of Chernobyl.

The Kazakh government had hoped to make the site available for agricultural use once again. But some areas are still so contaminated with plutonium that they have to be covered with huge,

two-meter thick steel plates to contain the radiation.

In 1998, the site was used for five additional atomic weapons tests. It is unknown whether any radiation leaked to the surface -- officials have claimed that none was detected. To date,

India has still not signed the Nuclear Non-Proliferation Treaty but has pledged never to strike first with nuclear weapons.

The speed of construction carried a great cost. In 1955, 251 workers were exposed to radiation during repair work. Then, on Oct. 10 1957, a reactor core began to burn. In an attempt to

extinguish the fire, a radioactive cloud was released, followed by a second one the next day. The radiation reached as far as Switzerland. The fires were only brought under control after two

days.

The authorities attempted to cover up the accident, initially saying only that there had been an incident, but that the workers involved had been able to scrub away the radiation with soap

and water. The only warning was that cow's milk in a radius of 200 miles from the reactor should not be consumed. In reality, the population surrounding the reactor received radiation doses

10 times higher than that seen as permissible for a lifetime.

According to official figures, 33 people were killed by the after-effects of the disaster, with more than 200 diagnosed with thyroid cancer. To this day, 15 tons of damage fuel rods are

still stored on site as is radioactive ash and mud, leftover from the fire. The reactor is now to be dismantled using a robot built exclusively for the project. In all, it is set to cost

some 500 million pounds.

A report completed by the IAEA in 2005 at the request of the Algerian government found that no further measures were necessary to clean up the Sahara testing grounds. Radiation levels, the

report found, were very weak. But Algerian victims' groups complain that France never carried out a decontamination program They say that cancer rates in the region are high and that

children are often born with abnormalities.

France wasn't the only country to test nuclear devices in the South Pacific. The US detonated 23 nuclear bombs at Bikini Atoll, starting in 1946. One of the blasts contaminated 23 crew

members of a Japanese fishing boat, an event which angered Japan and provided the inspiration for the 1954 film "Godzilla." Some 200 inhabitants of the islands were relocated, but several

were returned in the 1960s once the US declared the islands safe for habitation. They were, however, removed once again when failed pregnancies and birth deffects began to mount. Fish caught

in the atoll's lagoon are still not safe to eat.

The US also conducted nuclear tests at Enewetak Atoll. The photo above shows a Hydrogen bomb blast on Enewetak Atoll in 1952.

In March of 1997, 35 workers were contaminated with radiation at a nuclear reprocessing facility nearby, at the time, the worst nuclear accident in Japan's history. Just two years later at a

uranium reprocessing facility in Tokaimura, 80 workers were contaminated and two died in an accident.

Forty-five years later, the Palomares region still faces aftereffects of the accident. The Spanish government in Madrid has recently promised that cleaning up remaining contamination was a

priority and a US team of experts was dispatched to help advise the effort. An estimated half a kilogram of plutonium is believed to still be in the soil.

It wasn't until the 1970s that information about the catastrophe leaked to the West. The Soviet regime first admitted it in 1989. The number of deaths and details of the long-term effects

remain unknown. The 150-square-kilometer area over which the radioactive cloud dispersed remains closed off to this day and entry is forbidden.