Stopping the groundwater is crucial, says Tepco’s generalmanager for research and development of Fukushima Daiichidecommissioning, Shunichi Suzuki, adding that “Every day we haveapproximately 400 metric tons of groundwater.”Tepco is now building a bypass system to try to stop the water,flowing from high ground into the buildings, mixing with the wateralready being poured onto the leaking reactors through ajerry-rigged cooling system.”One approach we are considering is putting grout likecement. In other words, filling it in. That would block all theholes,” Suzuki said as cited by Reuters, adding that removingthe groundwater may take from two to four more years.One of the most challenging tasks for the operator remains thedisposal of water contaminated after it is poured onto thereactors. Radioactive material must be filtered out and stored.Work to treat and store the contaminated water is behindschedule, partly because of the groundwater flooding in. OnThursday, the company announced another delay in an operation toremove radioactive material from the water.The Japanese government has told the facility to revise by Juneits roadmap for cleaning up the site, which is expected to takewell over a quarter of a century.”What we need to do is isolate, remove and store the damagedand broken nuclear fuel safely. This work will take 30 to 40 yearsto complete,” plant manager Takeshi Takahashi told themedia.Experts say it could cost at least $12 billion to close thereactors down.Monday it will be two years since the worst atomic disastersince Chernobyl in 1986. On March 11, 2011, an earthquake and asubsequent tsunami knocked out cooling equipment at the company’sFukushima Daiichi plant north of Tokyo, leading to the meltdown ofthree reactor cores. More than 160,000 people were forced fromtheir homes.Another earthquake or tsunami could be fatal for the crippledFukushima nuclear plant, according to a nuclear engineer, as twoyears after the disaster it’s still vulnerable to naturaldisasters.”What remained intact after the disaster is completelyfragile and when the next one comes it’s going to collapse,” hetold The Weekend Australian newspaper.Local residents are still unaware if it’s safe to return totheir homes in the disaster area of Fukushima prefecture. Thedisplacement caused huge psychological distress, becoming one ofthe biggest health issues which emerged from the disaster,according to experts, while attention is also focused on thepotential cancer risks years after the tragedy.A health questionnaire sent to Fukushima residents by theFukushima Medical University found that around 15 percent of the67,500 respondents indicated high levels of stress – much higherthan the 3 percent among the general population of the country.