TOKYO: Japan stopped highly radioactive water leaking into the sea on Wednesday from a crippled nuclear plant and acknowledged it could have given more information to neighboring countries about contamination in the ocean. Despite the breakthrough in plugging the leak at the Fukushima Daiichi power plant, engineers need to pump 11.5 million liters of contaminated water back into the ocean because they have run out of storage space at the facility. The water was used to cool over-heated fuel rods. Nuclear experts said the damaged reactors were far from being under control almost a month after they were hit by a massive earthquake and tsunami on March 11. Plant operator Tokyo Electric Power (TEPCO) said it had stemmed the leak using liquid glass at one of the plants six reactors. “The leaks were slowed yesterday after we injected a mixture of liquid glass and a hardening agent and it has now stopped,” a TEPCO spokesman told Reuters. Engineers had been struggling to stop leaks from reactor No. 2, even using sawdust and newspapers. Neighbors South Korea and China are getting concerned about the world's worst nuclear disaster since Chernobyl in 1986, and the radioactive water being pumped into the sea, newspapers reported. “We are instructing the trade and foreign ministries to work better together so that detailed explanations are supplied especially to neighboring countries,” Chief Cabinet Secretary Yukio Edano told a news conference. Experts insisted the low-level radioactive water to be pumped into the ocean posed no health hazard to people. “The original amount of radioactivity is very low, and when you dilute this with a huge body of water, the final levels will be even lower than legal limits,” said Pradip Deb, senior lecturer in Medical Radiations at the School of Medical Sciences, Royal Melbourne Institute of Technology University.