Contaminated water has leaked from a treatment system at Japan’s crippled Fukushima nuclear plant, with some potentially entering the sea, the plant’s operator says, according to the BBC. Workers found the leak – caused by a crack in a concrete foundation – on Sunday morning. Tepco said some 45 cubic metres of water had escaped before sandbags blocked the leak. Some water leaked into a drainage ditch that flowed out to sea, it added. The nuclear plant was crippled by the 11 March earthquake and tsunami.