The operator of the Japan's crippled Fukushima nuclear power plant has started to discharge contaminated water into the Pacific Ocean to speed up efforts to tackle the crisis caused by last month's earthquake and tsunami, Xinhua reported Tuesday.
The nuclear plant had been damaged March 11 in a magnitude-9 earthquake that spawned a massive tsunami, leaving over 12,000 people dead.
In a bid to free up storage space for even more highly radioactive water that has hampered efforts to stabilise the reactors, the Tokyo Electric Power Co. (TEPCO) said it would have to get rid of the less toxic water.
A total of 15,000 tonnes of water containing radioactive material was set to be released, including contaminated groundwater from near No. 5 and No. 6 reactors, the plant operator said.
The level of radioactive substances in the water is up to 500 times the legal limit permitted for release in the environment, the Kyodo news agency reported.
TEPCO has revealed that radioactive iodine-131, which was more than 10,000 times the legal concentration limit, was detected in the water found in the pit.
Japan's Nuclear Industrial Safety Agency authorized the dumping as an emergency measure and said the disposal would pose "no major health risk".
"We have no choice but to release water tainted with radioactive material into the ocean as a safety measure," said Chief Cabinet Secretary Yukio Edano.
Experts say that while the radioactive material is likely to be diluted in the sea, it remains uncertain how the marine environment will be affected when considering the impact of highly radioactive water already leaked into the sea.
Contamination from the plant has been found in the air, ground, seawater and in local produce, including vegetables, dairy products, and mushrooms.