Fukushima out of control

SUBHEAD: Radiation levels soaring past danger levels. Japanese to dump radioactive water into ocean.

By Staff on 1 September 2013 for RTE News -

Image above: Japan's nuclear inspectors at water tanks early this month where radiation levels have rocketed in 'deplorable' situation. From original article.

Radiation near a tank holding highly contaminated water at Japan's crippled Fukushima nuclear plant has spiked 18-fold, the plant's operator says.

Radiation of 1,800 millisieverts per hour - enough to kill an exposed person in four hours - was detected near the bottom of one storage tank yesterday according to the Tokyo Electric Power Co (Tepco).

Readings on Aug 22 measured radiation of 100 millisieverts per hour at the same tank.

Japan's legal limits for nuclear plant workers' exposure during normal hours is just 50 millisieverts

Last month, Tepco revealed that water from the tank was leaking. Japan's chief cabinet secretary has described as the situation as "deplorable".

The Japanese nuclear regulator has raised the leak from a level 1 "anomaly" to a level 3 "serious incident" on the international scale for radiation releases.

The Fukushima plant was devastated by a tsunami on 11 March 2011 causing meltdowns at three reactors, radioactive contamination of the air, sea and food and the evacuation of 160,000 people.

It sparked the worst nuclear crisis since Chernobyl in Ukraine in the former USSR in 1986.

While there were no new leaks found at the tank, a Tepco spokesman said another leak had been detected from a pipe connecting two other tanks nearby.

"We have not confirmed fresh leakage from the tank and water levels inside the tank have not changed," the Tepco spokesman said. "We are investigating the cause."

Tepco said the radiation measured was beta rays, which would be easier to protect against than gamma rays.

The Tepco spokesman also said the higher level of radiation from the latest reading was partly because investigators had used a measuring instrument capable of registering greater amounts of radiation.

Instruments used previously had only been capable of measuring radiation up to 100 millisieverts, but the new instruments were able to measure up to 10,000 millisieverts.

With no one seeming to know how to bring the crisis to an end, Tepco said last week it would invite foreign decommissioning experts to advise it on how to deal with the highly radioactive water leaking from the site.

Water to be dumped in Pacific

By Kim-Kyung on 1 September 2013 for Australian Broadcast Company -

The head of Japan's nuclear watchdog has flagged dumping radioactive water from the Fukushima nuclear plant into the Pacific, but says the level of contamination in the water would be well within legal limits.

Speaking to foreign reporters in Tokyo, the head of the Nuclear Regulation Authority, Shinichi Tanaka, said there may be no choice but to pump radioactive water from Fukushima into the sea.

"I'm afraid that it is unavoidable to dump or release the water into the sea," he said.

But Mr Tanaka says most of the contamination would be removed first, meaning the radiation level in the water would be well below the legal limit.

There is more than 300,000 tonnes of contaminated water being stored at the Fukushima plant, with hundreds of tonnes being added to that every day.

Plant operator Tokyo Electric Power Co (TEPCO) has long struggled to deal with the massive amounts of water used to cool reactors that went into meltdown after being struck by an earthquake and tsunami in March 2011.

Key points:
Neighbouring countries and local fishermen have expressed concern at the mooted release from the plant, where contaminated water was already believed to have escaped into sea.

Mr Tanaka says he would try to gain the international community's understanding before dumping any treated water into the Pacific.

"The situation at Fukushima is changing everyday," Mr Tanaka said.

"Fukushima Daiichi has various risks. The accident has yet to be settled down."

The clean-up at the plant has been hit by a series of mishaps that have cast doubt on the utility's ability to contain the world's worst atomic disaster.

On Sunday the company said it had found highly radioactive water dripping from a pipe connecting two coolant tanks at one of four radiation hotspots.

Denouncing the firm's "careless management" of contaminated water, Mr Tanaka said: "We need to give them very strict instructions."

Charges against former PM dropped

Newspaper Sankei Shimbun reported on Monday that prosecutors had decided to drop criminal charges against former prime minister Naoto Kan, government officials and TEPCO executives over their roles in the immediate aftermath of the disaster.

Prosecutors had examined the case after local residents filed criminal complaints, but could not find enough evidence to show negligence of duty, the daily said, adding that the decision may be announced later this week.

Meanwhile, workers began switching off one of Japan's two working reactors on Monday, with the other set for shutdown later this month and no restarts in sight.

Kansai Electric Power had started reducing generating power at its Unit Number 3 at the Oi plant in the western prefecture of Fukui, a company spokesman said.

He said the reactor will be fully shut down by early Tuesday in readiness for inspections legally mandated within 13 months of the start of commercial operations.

The reactor is one of the only two still generating power in Japan. The other one, Unit Number 4 at Oi, is to be switched off on September 15, 2013.

Japan has turned to pricey fossil-fuel alternatives to fill the gap left by the shutdown of atomic plants, which had supplied about one-third of the resource-poor nation's electricity before the disaster.

Radioactive plume in US by 2014

By Jeremy Hsu on 1 September 2013 for Huffington Post - 

A radioactive plume of water in the Pacific Ocean from Japan's Fukushima nuclear plant, which was crippled in the 2011 earthquake and tsunami, will likely reach U.S. coastal waters starting in 2014, according to a new study. The long journey of the radioactive particles could help researchers better understand how the ocean’s currents circulate around the world.

Ocean simulations showed that the plume of radioactive cesium-137 released by the Fukushima disaster in 2011 could begin flowing into U.S. coastal waters starting in early 2014 and peak in 2016. Luckily, two ocean currents off the eastern coast of Japan — the Kuroshio Current and the Kuroshio Extension — would have diluted the radioactive material so that its concentration fell well below the World Health Organization’s safety levels within four months of the Fukushima incident. But it could have been a different story if nuclear disaster struck on the other side of Japan.

“The environmental impact could have been worse if the contaminated water would have been released in another oceanic environment in which the circulation was less energetic and turbulent,” said Vincent Rossi, an oceanographer and postdoctoral research fellow at the Institute for Cross-Disciplinary Physics and Complex Systems in Spain.

Fukushima’s radioactive water release has taken its time journeying across the Pacific. By comparison, atmospheric radiation from the Fukushima plant began reaching the U.S. West Coast within just days of the disaster back in 2011. [Fukushima Radiation Leak: 5 Things You Should Know]

Tracking radioactivity’s path
The radioactive plume has three different sources: radioactive particles falling out from the atmosphere into the ocean, contaminated water directly released from the plant, and water that became contaminated by leaching radioactive particles from tainted soil.

The release of cesium-137 from Fukushima in Japan’s more turbulent eastern currents means the radioactive material is diluted to the point of posing little threat to humans by the time it leaves Japan’s coastal waters. Rossi worked with former colleagues at the Climate Change Research Centre at the University of New South Wales in Australia to simulate the spread of Fukushima’s radioactivity in the oceans — a study detailed in the October issue of the journal Deep-Sea Research Part 1.

Researchers averaged 27 experimental runs of their model — each run starting in a different year — to ensure that the simulated spread of the cesium-137 as a "tracer" was not unusually affected by initial ocean conditions. Many oceanographers studying the ocean’s currents prefer using cesium-137 to track the ocean currents because it acts as a passive tracer in seawater, meaning it doesn't interact much with other things, and decays slowly with a long half-life of 30 years.

“One advantage of this tracer is its long half-life and our ability to measure it quite accurately, so that it can be used in the future to test our models of ocean circulation and see how well they represent reality over time,” Rossi told LiveScience. “In 20 years' time, we could go out, grab measurements everywhere in the Pacific and compare them to our model.”

Journey across the Pacific Rim
The team focused on predicting the path of the radioactivity until it reached the continental shelf waters stretching from the U.S. coastline to about 180 miles (300 kilometers) offshore. About 10 to 30 becquerels (units of radioactivity representing decay per second) per cubic meter of cesium-137 could reach U.S. and Canadian coastal waters north of Oregon between 2014 and 2020. (Such levels are far below the U.S. Environmental Protection Agency’s limits for drinking water.)

By comparison, California’s coast may receive just 10 to 20 becquerels per cubic meter from 2016 to 2025. That slower, lesser impact comes from Pacific currents taking part of the radioactive plume down below the ocean surface on a slower journey toward the Californian coast, Rossi explained.

A large proportion of the radioactive plume from the initial Fukushima release won't even reach U.S. coastal waters anytime soon. Instead, the majority of the cesium-137 will remain in the North Pacific gyre — a region of ocean that circulates slowly clockwise and has trapped debris in its center to form the “Great Pacific Garbage Patch” — and continue to be diluted for approximately a decade following the initial Fukushima release in 2011. (The water from the current power plant leak would be expected to take a similar long-term path to the initial plume released, Rossi said.)

But the plume will eventually begin to escape the North Pacific gyre in an even more diluted form. About 25 percent of the radioactivity initially released will travel to the Indian Ocean and South Pacific over two to three decades after the Fukushima disaster, the model showed.

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