A look at the Fukushima and Chernobyl nuclear disasters

Demonstrators display placards calling on the government to protect children against radiation during an anti-nuclear protest in Tokyo on March 5, 2016. PHOTO: AFP
A view of the abandoned city of Pripyat is seen near the Chernobyl nuclear power plant in Ukraine on March 23, 2016. PHOTO: REUTERS
The farmlands of Iitate are now covered with black bags containing contaminated soil. ST PHOTO: SEOW BEI YI

FUKUSHIMA, JAPAN - Japan this month (March) marked the fifth anniversary of the Fukushima nuclear disaster with a series of sombre remembrance ceremonies across the country.

At 2.46pm local time (1.46pm in Singapore) on March 11, 2011, a 9.0-magnitude earthquake struck under the Pacific Ocean, triggering a 10 metre wall of water that devastated the north-eastern coast of Japan. It caused meltdowns in three reactors at the Fukushima Daiichi (No. 1) Nuclear Power Plant in the worst nuclear accident since the Chernobyl accident on April 26, 1986.

Ahead of the 30th anniversary of the Chernobyl tragedy in April, The Straits Times takes a close-up look at both disasters.

How many people were affected?

Fukushima: Some 18,500 people died or are still missing from the earthquake and tsunami. Another 470,000 people were evacuated due to the nuclear fallout. They include those who live within a 20km radius from the Fukushima No. 1 nuclear plant, as well as residents living in areas around 30km away. Some 100,000 remain displaced till today.

Chernobyl: About 116,000 people were evacuated within three weeks of the accident which was caused by a flawed reactor design. The plant was located in Soviet Ukraine, 20km south of the border with Belarus. More than 220,000 people from Belarus, the Russian Federation and Ukraine have since been resettled in the less contaminated areas.

What was the impact on health?

Fukushima: Over 300,000 people below 18 have been screened for thyroid cancer with about 150 testing positive. Some experts have put this down to a result of more rigorous testing rather than the direct impact of radiation. Last October, Japan confirmed the first case of radiation-linked cancer for a former worker of the stricken Fukushima No. 1 power plant.

Chernobyl: Immediate casualties included firefighters battling the initial explosion and fires. Although the fires were put out in a few hours, radiation doses on the first day spiked to 20,000 millisieverts (mSv), about 8,000 times more than the average dose of 2.4 mSv of natural background radiation people are exposed to in a year, causing 28 deaths by end-July 1986. Six of them were firemen.

By 2000, about 4,000 cases of thyroid cancer had been diagnosed in children who were exposed to the radioactive fallout. But a United Nations Scientific Committee on the Effects of Atomic Radiation report the same year also noted that besides the increase in cases of thyroid cancer, "there is no evidence of a major public health impact attributable to radiation exposure 14 years after the accident". By 2005, 15 people who were exposed to high radiation died from thyroid cancer.

What has happened since the nuclear disasters?

Fukushima: Dozens of nuclear reactors were shuttered after the March 2011 disaster, and efforts to get them restarted have become entangled in a web of lawsuits amid public fears.

As of today, there are only two operating nuclear reactors in Japan. Prime Minister Shinzo Abe said in March that Japan "cannot do without nuclear power" as his country turns to liquefied natural gas in record quantities to make up for lost nuclear capacity. Before Fukushima, Japan got almost 30 per cent of its electricity from nuclear. The Abe administration aims have nuclear energy supply meet at least 22 per cent of Japan's power needs by 2030.

In February, three former utility executives from the Tokyo Electric Power Company (Tepco), which owns the stricken power plant in Fukushima, were charged with negligence. They were the first to face criminal charges over the disaster. Prosecutors alleged Tepco knew it was possible the plant could be hit by a tsunami bigger than it was designed to withstand, but chose to ignore long-term safety in order to save costs. Tepco's internal calculation in 2008 was that a 15.7-metre tsunami could hit the plant, yet it built a plant that could withstand only a 5.7 m wall of water. Tepco has argued that the risk of such a tsunami was so low that it was "outside the realm of realistic possibilities".

Chernobyl: There were four reactors at the Chernobyl plant, the last of which was shut down only in 2000 under immense international pressure.
This schedule was agreed during a visit by then-US President Bill Clinton to the Ukraine capital of Kiev that year. Reactor 4 was where the 1986 accident happened, while reactor 2 was put offline due to a fire in 1991. Reactors 1 and 3 were capable of producing electricity and due to Ukraine's dependence on nuclear power, continued operations until 1996 and 2000 respectively.

A large area of the 4,200 sq km exclusion zone remains out of bounds, including the well-documented town of Pripyat. Tour groups can travel up to within 300 m of the destroyed reactor, which reportedly still emits more than 25 times what is the normal background radiation levels despite being cocooned within a concrete enclosure called a sarcophagus.

Geiger counters monitor the radiation levels in a cafeteria which serves tourists and the estimated 6,000 people who still work within the exclusion zone. Anyone exiting the radioactive areas has to undergo radiation inspection points. The job of the workers is to build a new 20,000-tonne steel cocoon called the Chernobyl New Safe Confinement, which is scheduled to be completed by 2017. The new enclosure is necessary because existing controls cannot sufficiently contain the radiation. It costs S$3.1 billion, and will likely contain the radiation for 100 years.

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