Monday, 21 October 2013

Radioactive water leaks at Fukushima

This is, as I read it, from rain that is not from last week's typhoon. If so, what is a typhoon arriving mid-week going to do to defenses that seem to be already overwhelmed?

I am doubtful about reports about a loss of power. As to conjecture that Fukushima Daiichi will have to be evacuated - we'll have to wait and see what transpires after Francisco hits.

Radioactive water leaks at Fukushima as operator underestimates rainfall
Highly radioactive water overflowed barriers into Japan's Fukushima Daiichi nuclear power plant, its operating utility said on Monday, after it underestimated how much rain would fall at the plant and failed to pump it out quickly enough


21 October, 2013, 03.40 GMT



The utility, Tokyo Electric Power Co, also known as Tepco, has been battling to contain radioactive water at the nuclear complex, which suffered meltdowns and hydrogen explosions following a devastating earthquake and tsunami in March 2011.

Dealing with hundreds of tonnes of groundwater flowing through the wrecked nuclear plant daily is a constant headache for the utility and for the government, casting doubt on Prime Minister Shinzo Abe's promises that the Fukushima water "situation is under control."

After heavy rain on Sunday, water with high levels of radioactive strontium overflowed containment areas built around some 1,000 tanks storing tonnes of radioactive water at the plant, Tepco said. The radioactive water is a by-product of an improvised cooling system designed to keep the wrecked reactors under control in case of further disaster.

Tepco said it had planned to pump out the accumulating rainwater into empty tanks, check it for radioactivity, and if it was uncontaminated, release into the sea. But the company was overwhelmed by the amount of rainwater.

"Our pumps could not keep up with the rainwater. As a result, it flowed over some containment areas," said Tepco spokesman Yoshikazu Nagai. The company had planned for 30 to 40 millimetres of rainfall on Sunday, but by late afternoon the rainfall already stood at around 100 millimetres, he said.

The ongoing crisis at the Fukushima Daiichi plant, 220 km (130 miles) north of Tokyo, highlight the immensity of the task of containing and controlling radioactive water and eventually decommissioning the plant, processes expected to take decades.

Earlier this year, Tepco lost power to cool spent uranium fuel rods at the plant after a rat shorted wiring at the plant.

In the latest incident, containment areas surrounding 12 of 23 groups of tanks overflowed, with one of them containing Strontium-90 as highly concentrated as 710 Becquerels per litre - 71 times higher than the level set by the company as safe for release.

Strontium-90 is a by-product of the fission of uranium and plutonium in nuclear reactors as well as nuclear weapons, the U.S. Environmental Protection Agency says on its website.

Tepco said it will prepare some 30 extra pumps and lay additional 10 kilometres of pipes to prevent overflowing from happening again.

The utility has come under increased scrutiny after it found in August that 300 tonnes of highly radioactive water had leaked from one of the hastily built storage tanks at the Fukushima site. Japan stepped up support for the embattled utility in September, pledging half a billion dollars to help contain contaminated water at Fukushima.

Tepco is seeking permission to restart its only remaining viable plant - Kashiwazaki Kariwa, the world's largest nuclear power station, to cut high fuel costs and restore its finances.




For RT article GO HERE




Fukushima Watch: Parsing the Latest Radioactive Spike in “Zen-Beta’’
In an alarming Friday-morning alert, the operator of the stricken Fukushima Daiichi nuclear-power plant said that radiation levels on Oct. 17 had spiked some 6,500 times higher overnight, at a well near the spot where 300 tons of highly radioactive water is thought to have leaked in August.


21 October, 2013, 03.40 GMT



Where that 300 tons of water went has always been unclear, since there was no physical trace of it in the area. The well had been dug to check whether there were any signs that contaminated water was spreading from the leak site, and the spike in radioactivity – a day after Typhoon Wipha dumped masses of rain on the plant – suggests that it was starting to, said Tokyo Electric Power Co.

It’s a lot harder to figure out just how bad that creeping contamination is, however. JRT’s preliminary answer: It could be quite bad, since Tepco’s data suggests the water could contain dangerous strontium-90 at a level thousands of times higher than the legal emission limit.

Tepco tests water at many of Fukushima Daiichi’s wells daily, using a quick method that measures something it calls “zen-beta’’ in Japanese – or “all-beta’’ in English. That’s a measure of how much beta radiation there is in the sample, using a unit called becquerels (Bq) that tracks the energy released per second.
Friday’s alert said that the zen-beta in the contaminated well was 400,000 Bq per liter – a record-high measurement.

But just what does that mean?

Beta radiation releases less energy and so is weaker than gamma – the other type of radiation commonly released by the elements Tepco tracks at Fukushima Daiichi. So


What’s emitting that beta radiation makes a big difference, however. Beta-emitter tritium, for instance, is a radioactive form of hydrogen seen as one of the least harmful elements – while strontium-90 is a much more dangerous element linked to bone cancer. Nuclear plants in Japan are allowed to release 60,000 Bq per liter of tritium, but only 30 Bq per liter of strontium-90.

So how much of that 400,000 Bq per liter is comprised of what? Tepco says it doesn’t know since it takes a lot of time to do that analysis.

Still, it turns out that none of it is tritium, since the type of quick measurement used for the beta-radiation check isn’t sensitive enough to pick up tritium, says a Tepco spokesman.

What’s more, Tepco has found that the zen-beta from the kind of water that was stored in the leaky tank is generally half from strontium-90 and half from a radioactive form of an element called yttrium, which is formed from strontium-90 in the process of nuclear decay.

That would suggest there could be 200,000 Bq per liter of strontium-90 in the well – more than 6,600 times the allowed emission limit.




Fukushima overwhelmed with radioactive water
Temporary cooling system inundated after operator Tepco failed to estimate amount of rain that would fall over weekend.



21 October, 2013,


Highly radioactive water overflowed barriers into Japan's Fukushima Daiichi nuclear power station after its operator Tepco underestimated how much rain would fall and failed to pump it out quickly enough.

Tepco has been battling to contain radioactive water at the nuclear complex, which suffered meltdowns and hydrogen explosions following a devastating earthquake and tsunami in March 2011.

Dealing with hundreds of tonnes of groundwater flowing through the wrecked nuclear station daily is a constant problem for the utility and for the government, casting doubt on the promises of Japan's prime minister, Shinzo Abe, that the Fukushima water "situation is under control".

After heavy rain on Sunday, water with high levels of radioactive strontium overflowed containment areas built around some 1,000 tanks storing tonnes of radioactive water at the plant, Tepco said.

The radioactive water is a by-product of an improvised cooling system designed to keep the wrecked reactors under control in case of further disaster.

Tepco said it had planned to pump out the accumulating rainwater into empty tanks, check it for radioactivity, and if it was uncontaminated, release into the sea. But the company was overwhelmed by the amount of rainwater.

"Our pumps could not keep up with the rainwater. As a result, it flowed over some containment areas," said Tepco spokesman Yoshikazu Nagai.

The company had planned for 30mm to 40mm of rainfall on Sunday, but by late afternoon the rainfall already stood at about 100mm, he said.

The ongoing crisis at the Fukushima Daiichi plant, 220km north of Tokyo, highlights the immensity of the task of containing and controlling radioactive water and eventually decommissioning the plant, processes that are expected to take decades.

Tepco is seeking permission to restart its only remaining viable power station - Kashiwazaki Kariwa, the world's largest nuclear power facility, to cut high fuel costs and restore its finances.




Fukushima Fear: Radiation rises, 'nobody really knows how to dodge disaster'


There's a worrying spike in radiation at the Fukushima nuclear plant. Readings from a water storage tank have rocketed six-and-a-half-thousand times higher in two days. A powerful typhoon swept through Japan earlier this week, causing toxic waters to be released into a drainage ditch leading to the Pacific Ocean. It's compounded what's been a worsening situation at the plant in recent months, as Irina Galushko explains


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