information about Fukushima published in English in Japanese media info publiée en anglais dans la presse japonaise
28 Juillet 2013
http://mainichi.jp/english/english/newsselect/news/20130727p2a00m0na008000c.html
Water in a service tunnel on the seaward side of the stricken Fukushima No. 1 nuclear plant is contaminated with 2.35 billion becquerels of radioactive material per liter, plant operator Tokyo Electric Power Co. (TEPCO) revealed on July 27.
TEPCO believes the water is the source of the contamination the utility recently admitted had been found in an observation well on the plant grounds, leading to suspicions that radioactive water was seeping into the Pacific Ocean.
According to the utility, about 750 million becquerels per liter is cesium-134, which has a half-life of about two years, while cesium-137 -- with a half-life of roughly 30 years -- makes up 1.6 billion becquerels per liter of the contamination. Another 750 million becquerels is thought to be strontium and other radioactive elements that emit beta radiation.
In April 2011, soon after the meltdowns at the Fukushima plant, there was a leak of highly-contaminated water near the No. 2 reactor's water intake. Tests of that spill showed radioactive cesium contamination of 3.6 billion becquerels per liter. TEPCO believes that the water in the service tunnel may be left over from the April 2011 leak.
TEPCO says it will start operations to clean up the service tunnel in September this year.
Kyodo
Tokyo Electric Power Co. said Saturday that the trench problem at the crippled Fukushima No. 1 nuclear plant has cropped up again and is sending highly radioactive water into the sea.
The water in the underground passage, which runs under the turbine building of reactor 2, contains 2.35 billion becquerels of cesium per liter, roughly the same as that measured right after the crisis began in spring 2011.
The latest sample, taken Friday from a trench, contained 750 million becquerels of cesium-134, 1.6 billion becquerels of cesium-137 and 750 million becquerels of other radioactive substances, the utility said.
A sample from April 2011 contained 1.8 billion becquerels of both cesium-134 and cesium-137 per liter. Cesium has a half-life of about 30 years.
The trench is believed to be the source of the groundwater problem that’s been baffling Tepco’s experts for months. Their current theory is that the highly radioactive water found and left in the trench in 2011 is now leaking directly into the groundwater, which is seeping into the sea.
Tepco finally admitted Monday that contaminated water was getting into the Pacific. The admission came after the Nuclear Regulation Authority pointed out that highly radioactive water was “strongly suspected” to be seeping into the ground under the site and making its way to the sea.
The utility hopes to halt the problem by building a wall out of liquid glass between the reactors and the sea and removing the contaminated water from the underground passage.
Water in plant's tunnel still highly contaminated
http://www3.nhk.or.jp/nhkworld/english/news/20130727_25.html
The operator of the damaged Fukushima Daiichi nuclear power plant says contaminated water found in one of the plant's tunnels is as highly radioactive as the water that leaked into the sea in April 2011, soon after the accident.
Highly radioactive substances have been detected in coastal observation wells on the plant's premises and in nearby seawater since May of this year.
Tokyo Electric Power Company, or TEPCO, admitted that contaminated water was leaking into the sea but has not been able to identify its source.
The firm says 2.35 billion becquerels of cesium per liter was detected in samples collected on Friday in a tunnel located near the plant's Number 2 reactor and 50 meters from the coast.
Contaminated water with a similar level of radioactivity leaked into the sea in April 2011, soon after the nuclear accident.
The utility says contaminated water that accumulated after the accident is believed to have remained in the tunnel.
The company says there may be other causes, but that it has not been able to identify them.
TEPCO plans to continue to measure the concentration and level of contaminated water in coastal tunnels near the Number 2 and 3 reactors.
It also intends to take measures to reduce the amount of contaminated water and prevent it from leaking into the sea.
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