2 may 2011

[News from the English-language website of NHK World, the Japanese equivalent of BBC World Service.]

Level now 3300 times limit at No. 2 reactor intake

The operator of the troubled Fukushima nuclear power plant says it has detected higher levels of radioactive materials in seawater samples from near the water intake at one of the reactors.

Tokyo Electric Power Company says it detected 130 becquerels of radioactive iodine-131 per cubic centimeter in samples collected near the water intake for the Number 2 reactor on Saturday. The figure is 3,300 times the national limit and 30 percent higher than the level detected on Friday.

It's the same site where iodine-131 at a level 7.5 million times the limit was detected on April 2nd. TEPCO says it detected radioactive cesium-134 at 120 times the limit and cesium-137 at 81 times the limit at the same place on Saturday. But the readings taken for these 2 substances were down for the third straight day.

There was a 90 percent drop in levels of iodine and cesium to the south of water intakes for reactors 1 through to 4.

The level of highly radioactive water in the sea rose to three to four times the level of the previous day along the coast 10 kilometers south of the power plant.

TEPCO says it's continuing to monitor the level, though there has not been a fresh leak of highly contaminated water.

Monday, May 02, 2011 05:45 +0900 (JST)

Cesium found in sludge

Relatively high levels of radioactive cesium have been detected in the sludge from a waste water treatment plant in Koriyama City, Fukushima Prefecture.

The prefectural government is tracking some of the sludge that has been shipped out of the prefecture to be used in making cement.

The prefecture's investigation found that the sludge contained 26,400 becquerels of radioactive cesium per kilogram.

The solidified slag made from it contained 334,000 becquerels per kilogram, which is 1,300 times the level before the accident at the Fukushima Daiichi nuclear power plant.

The prefecture says rain likely washed radioactive substances from the surface of the ground into the sewer, and they became concentrated through processing.

The sludge from the facility is transported out of the prefecture and used to produce cement.

The prefectural government will suspend the recycling and track the sludge that has been shipped since the accident to determine how it has been used.

The land and transport ministry says it will report the incident to the Nuclear Safety Agency, and coordinate with the Environment Ministry and other relevant organizations to find ways to process the sludge safely. The sludge must be kept at the facility until a solution is found.

The ministry says there is no precedent for this, but that it will decide soon what to do.

Sunday, May 01, 2011 23:20 +0900 (JST)

[4C comment: The slag made from the sludge has levels of cesium 1300 times higher than pre-accident levels. There is no mention in the article of what a "safe" level is considered to be, but a level of hundreds of thousands of becquerels per kg looks high for anything that is not destined for long-term secure storage away from human activities. Cesium-137 has a halflife of 30.2 years, so it is considered potentially hazardous for around 300 years (rule of thumb is 10 halflives).]


Shareholders want nuclear plants closed

A group of Tohoku Electric Power Company shareholders will submit a motion calling for the closure of the company's nuclear plants.

220 individual stockholders decided on the move ahead of the company's annual shareholders' meeting at the end of next month.

The investors are demanding that the utility state in its agreement with shareholders that it will close its nuclear power plants and end its investment in a reprocessing plant in Aomori Prefecture and similar projects.

The shareholders say the problems at the Tokyo Electric Power Company's Fukushima Daiichi nuclear plant was a warning that accidents at any nuclear plant can lead to dangers that cannot be contained by any one company.

They will deliver documents on the demand to the company on Monday. The subject is expected to be discussed at this year's shareholders' meeting.

The move comes after the firm measured tsunamis higher than expected and strong tremors at its Onagawa nuclear plant in Miyagi Prefecture during the March 11th earthquake and the aftershock on April 7th.

The Tohoku Electric Power Company declined to comment on the move. But it said it had safely suspended operations at its power plants and that it will improve its risk management and strengthen measures to check its equipment.

Sunday, May 01, 2011 23:20 +0900 (JST)

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