information about Fukushima published in English in Japanese media info publiée en anglais dans la presse japonaise
14 Juillet 2014
July 14, 2014
TEPCO's rubble removal at Fukushima plant likely spread cesium to rice paddies
http://ajw.asahi.com/article/0311disaster/fukushima/AJ201407140051
By MIKI AOKI/ Staff Writer
Tokyo Electric Power Co. plans to clear debris from the Fukushima No. 1 nuclear plant despite strong indications that earlier removal work contaminated rice paddies far from the stricken facility, The Asahi Shimbun has learned.
The agriculture ministry pointed out the possibility that the removal of rubble from the plant site in August last year spread radioactive substances to 14 rice paddies in Minami-Soma outside the evacuation zone and more than 20 kilometers from the plant.
Cesium levels in the rice crops harvested last autumn exceeded the safety standard of 100 becquerels per kilogram, according to ministry officials.
Radioactivity readings above the standard were also detected from rice grown at five locations inside the evacuation zone.
The ministry called on TEPCO to take preventive measures in its debris-removal work.
Although the utility has since suspended its clearing operations at the plant, the company plans to soon dismantle a cover installed on the No. 1 reactor building, where highly contaminated debris remains to be removed.
TEPCO has not told the public about the ministry’s findings.
“(If TEPCO hopes to resume rubble-clearing operations), providing information on the possibility of the spread of (contaminated substances) is a major premise,” said Takehiko Murayama, a risk management professor at the Tokyo Institute of Technology.
An agriculture ministry survey found that some parts of rice crops that emerged in mid-August were contaminated. If the crops had drawn up radioactive substances released into the soil immediately after the Fukushima nuclear plant was hit by the Great East Japan Earthquake and tsunami in March 2011, those substances would be detected uniformly throughout the plants.
Since they weren’t, the ministry concluded that the radioactive substances had been newly released at least by the end of September 2013, the harvest period for the rice crops.
The ministry is pointing to Aug. 19, when TEPCO removed a large piece of wreckage from the plant’s No. 3 reactor building. Radioactive dust under the debris blew away in the process and exposed two workers away from the reactor to radiation.
A maximum reading of 13 becquerels per square centimeter was detected from the heads of the two workers. Air dose rates increased at five measuring points 2.8 to 8.3 km north-northwest on the leeward side of the nuclear plant.
The Fukushima prefectural government attributed the increase in air dose rates to radioactive substances released during the Aug. 19 removal operation.
“We cannot think of any other factors,” said a prefectural official. “It is almost certain that the rise in readings was caused by the clearance work.”
The farm ministry also said Minami-Soma lies downwind of the five measuring spots, and that the System for Prediction of Environmental Emergency Dose Information (SPEEDI) estimated that the released particles would reach the city within three hours.
It also says Minami-Soma is the only city with more than one site contaminated with cesium levels exceeding the safety standard, and that the high readings were not detected from rice crops in the area the previous fiscal year.
Ministry officials said they planned to disclose the findings after confirming the cause of the rice crop contamination.
TEPCO said it will resume debris-clearing efforts at the nuclear plant while taking preventive measures based on the ministry’s instructions that came in March this year.
However, the utility said it has yet to learn how far the released particles spread.
The company said its plans to dismantle the cover on the No. 1 reactor building will be the fastest way to remove wreckage from the site. TEPCO will also spray more anti-scattering agents than usual during the operation.
But the company acknowledged that the procedure will still lead to the release of a large amount of radioactive substances, and the spread of the substances will depend on the weather and the wind direction.
Kyodo
Debris cleanup work by Tokyo Electric Power Co. at the Fukushima No. 1 nuclear plant may have led to the contamination of rice crops in nearby areas, agriculture ministry officials said Monday.
Radioactive cesium exceeding the government limit of 100 becquerels per kilogram was detected in rice crops from Minamisoma, Fukushima Prefecture, last year, including areas located more than 20 km from the crippled nuclear plant.
Farm ministry officials said they could not deny the possibility that radioactive dust was stirred up when Tepco cleaned up debris at the No. 3 reactor last August and that the dust could have made its way north to Minamisoma.
The ministry told Tepco in March to take measures to prevent dust dispersal, according to the officials.
A Tepco spokesman said the company does not deny the possibility that its cleanup work is to blame but added it isn’t clear whether that was the direct cause of the contamination.
The tainted rice was tested by the Fukushima Prefectural Government and never made it to market.
Debris removal may have caused rice contamination
http://www3.nhk.or.jp/nhkworld/english/news/20140714_17.html
Rice paddies located about 20 kilometers from the Fukushima Daiichi plant were found contaminated with radioactive cesium blown by the wind.
The agriculture ministry called for plant operator TEPCO to take measures.
The Fukushima Prefectural government revealed that last year's harvested rice from 14 locations in the city of Minami Soma contained more than 100 becquerels of cesium per kilogram. This is beyond the government's safety limit. The contaminated rice has been removed.
The ministry says cesium was detected on the outside of the husk. Debris removal work conducted last August at the Number 3 reactor may be one of the reasons for the contamination.
TEPCO reportedly told the ministry it will use chemicals to stop dust from spreading during debris removal work. The utility said it will increase monitoring of the spreading dust.
Neither the ministry nor the utility told Minami Soma City officials the work at the plant may have contaminated the crop.
City officials say they were greatly startled. They said the ministry should have explained the matter to local authorities much earlier.
The ministry says it was going to report the finding after it determined the cause.
TEPCO is scheduled to conduct a large-scale debris removal work at Number One reactor. For this, it plans to disassemble covers which had been put to prevent the radioactive materials from spreading.
Jul. 14, 2014 - Updated 05:47 UTC
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