challenge after the finding on Monday that at least 300 tons of highly radioactive water

Tokyo Electric Power Company says it will step up monitoring and control of radioactive water leaks at its wrecked Fukushima nuclear plant in northeast Japan.The utility faces the challenge after the finding on Monday that at least 300 tons of highly radioactive water has leaked from a storage tank into the ground.TEPCO started to remove the remaining 700 tons of contaminated water from the tank on Tuesday to find out how the leak occurred.Most of the leaked water is believed to have flowed out of a low barrier around the tank.Under the instruction of the nation's nuclear regulator, the utility is also examining soil and groundwater to see if the tainted water has flowed into the sea.The plant has seen a series of water leaks from tanks and other problems as it tries to clean up the accident caused by the 2011 earthquake and tsunami.Contaminated groundwater has also been found to be leaking into the sea, requiring the utility to find drastic steps to contain the radioactive water building up at the plant.  Aug. 20, 2013 - Updated 22:19