they hope to learn how cesium moves from fallen leaves to soil. the results show that rain washed it off leaves six months after the accident. the researchers say that as the leaves decomposed, the cesium moved into the soil. after two years of research, they say that only about 0.1% to 0.2% has reached a depth of 10 centimeters. >> translator: the results suggest that the cesium has not penetrated deep into the ground. i think the findings will be useful to decontaminate affected areas. >> they concluded it's unlikely underground water has probably carried radioactive cesium from the soil to nearby areas. >>> japanese leaders are looking to the outer reaches of their territory to launch a new anti-global warming strategy. they want residents of remote islands to one day rely on renewable energy for power generation instead of diesel. >> translator: we want to start establishing a low carbon society from remote islands. a society that can produce energy locally, and then store it. >> officials with the environment ministry say residents on about 1

as leaves decomposed the cesium moved into the soil. after two years of research, 0.1 to 0.2% has reached a depth of 10 centimeters. >> translator: the result suggests the cesium has not penetrated deep into the ground. i believe the findings are useful for decontaminating areas. >> the water is unlikely to have carried to nearby areas. cleaning up areas around the plant has been a major challenge for japanese leaders. cabinet ministers say the government should bear part of the cost that could be million of the. local governments are carrying out decontamination work. the plant operator of the electric plant is covering expenses. tepco executives are asking the go. to contribute toward the massive costs. accelerating the clean up work is crucial for the prefecture to recover quickly. >> translator: the government is studying the matter comprehensively including the financial issue. >> finance minister says the government is responsible for the problem. >> translator: the government has long promoted energy as a national policy. i think

they found cesium in a sample of ocean water. they took the sample from a monitoring point about a kilometer off the coast. this is the first timeworkers have detected radio active material in that area. tepco officials say they measured 1.4 becquerels per liter of cesium in the sample. they say the level is lower than the safety standard for drinking water set by the world health organization, 10 becquerels per liter. they did not detect cesium in another sample taken on thursday. workers started checking the water in that area in august after they found contaminated groundwater had been seeping into the ocean. >>> japanese nuclear regulators will soon be getting international support in their efforts to monitor the impact of the crisis. specialists with the united nations nuclear watch talk will join teams checking radiation levels offshore. >> translator: monitoring nurk activity is very important. >> the assistance was offered to the head of the nuclear authority. ieaa says figures released by japan alone would not convince p

they found cesium at the location two weeks ago. the officials say they can't explain why the substance is present there, but almost nonexistent elsewhere outside the plant's harbor. they're planning to install devices that can check radiation levels offshore at all times. >>> as tepco managers struggle to decommission the fukushima plant, they're trying to prepare another facility to resume operations. they're working to restart two reactors on the sea of japan coast. they allowed the media to see a new safety feature. the filtered vent system would be used in the event of a severe accident. tepco workers have started installing the devices in a reactor building at the kashiwazaki-kariwa. filtered vents are designed to release pressure in containment vessels if an accident occurs. they use a combined water and chemical filtration system to reduce the amount of radioactive materials released to almost zero. the governor is worried the system cannot contain all dangerous substances. >> translator: even if we use this system, we still

a team of american scientists reported last year that they detected low levels of radioactive cesium in 33 of 50 bluefin caught off the coast of california. team members said the damaged nuclear plants with a source of the contamination. they made their conclusion based on levels of cesium 134 which has a half-life of about two years and only produced by nuclear reactors. the japanese and u.s. researchers are trying to start a joint study to determine how the toxins got into the tuna. nhk explains in japan in depth. >> reporter: this professor has been did you did mass reen creatures in the waters. marine creatures in the waters. >> translator: we estimated concentration levels to be so low they wouldn't be detectible in the u.s. but the fact that they found contaminated fish off the coast of the u.s. really shocked us. even if the figures are extremely low. they say the level of contamination doesn't pose a threat to human health. >> reporter: but he says he wants to share his data with the u.s. researchers to figure out how the tuna pick up the radioactive material. he says it take

they made their conclusion based on levels of cesium 134 which has a half life of about two years and only produced by nuclear reactors. the japanese and u.s. researchers are trying to start a joint study to determine how the toxins got into the tuna. nhk world has more in "japan in depth." >>> the professor has been studying marine creatures in the waters of fukushima prefecture. >> translator: we estimated concentration levels to be so low they wouldn't be detectible in the u.s. but the fact they found contaminated fish off the coast of the u.s. really shocked us. even if the figures are extremely low. >> he says the level of contamination doesn't pose a threat to human health, but he says he wants to share his data with the u.s. researchers to figure out how the tuna pickup the radioactive material. he says it take time for tuna to accumulatee radioactive substances since they're at the top of the marine food chain. tiny creatures such as plankton absorb radioactive substances first. small fish then eat the plankton. and big fish like tuna eat the smaller ones. recent study show bl