6 Feb (NucNet): Radiation levels in purified groundwater pumped into the sea from sub-drain and groundwater drain systems at the Fukushima-Daiichi nuclear station in Japan were substantially below the operational targets set by Tokyo Electric Power Corporation (Tepco), according to a report submitted by Tepco to the International Atomic Energy Agency. Tepco said its operational targets are well below those specified by the country’s nuclear regulator and about one-tenth lower than targets set by the World Health Organisation for acceptable drinking water. The results were confirmed by the Japan Chemical Analysis Centre, Tepco said. According to Tepco, analysis of seawater sampled during the discharge operation at the nearest seawater sampling post from the discharge point showed that radiation levels in seawater remain lower than the limits laid down by the regulator. The groundwater, which flows onto the nuclear site from hills behind the facility, mixes with contaminated water being used to cool melted fuel. The treated groundwater is only released into the sea when it is confirmed that concentrations of radioactive material have been reduced to between 0.001% and 0.0001% of their original levels and are below operational targets.