Efforts to remove radiation-contaminated water filling up at a troubled reactor building and an underground trench connected to it at the crisis-hit Fukushima Daiichi nuclear power plant have hit a snag, casting a shadow on restoration of the vital cooling functions at the site, the government's nuclear safety agency said Wednesday.
The evolving nuclear crisis also showed no signs of abating, as the agency said the same day the highest concentration of radioactive iodine-131 was detected Tuesday in a seawater sample taken near the plant's drainage outlets in the Pacific Ocean. The density was 3,355 times the maximum level permitted under law.
Workers rushed to pump out radiation-polluted water that has been filling up the basement of the No. 1 reactor's turbine building and the tunnel-like trench connected to it, but they found out Tuesday a tank accommodating the water from the building had become full, the Nuclear and Industrial Safety Agency said.
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Experts had suggested that the emergency injection of seawater into the Nos. 1-3 reactor cores to cool them down would eventually lead to their dismantlement, as salt and impure substances in seawater causes equipment corrosion.
Nishiyama said it is expected to take at least 20 years to finish the procedures to decommission the six-reactor Fukushima plant. Katsumata said TEPCO considers it as an option to cover the troubled reactors with ''stone coffins'' made of concrete and iron, a solution adopted in the 1986 Chernobyl nuclear crisis.
Kyodo News