An investigation by Greenpeace has concluded that the water Japan is planning to dump into the ocean from the Fukushima nuclear plant contains not only tritium, as has been widely reported, but a number of other radioactive substances as well.
Those include carbon-14, which its says concentrates in fish at a level thousands of times higher than tritium and has the potential to damage human DNA.
In its report, Greenpeace said the plan goes against the Convention on the Law of the Sea.
A senior nuclear specialist with Greenpeace Germany, Shaun Burnie, said the Japanese government is "covering up the scale of the crisis at Fukushima."
He also said Japan has failed to explain to people in Fukushima and in neighboring countries that the contaminated water to be discharged contains dangerous levels of carbon-14.
On Friday, the science committee at South Korea's National Assembly adopted a resolution urging Tokyo to dispose of the radioactive water safely.
The committee demanded that the water not be dumped without Japan consulting the international community and its neighbors, including South Korea and China.
It plans to send the resolution to the Japanese Embassy in Seoul.
In the meantime, the Japanese government has reportedly decided to delay announcing the discharge plan.
There had been speculation that it would officially announce the plan next week.
Yoon Jung-min, Arirang News.