Japan to release Fukushima water into sea

Japan says it will release more than a million tonnes of contaminated water from the destroyed Fukushima nuclear station into the sea.

On Tuesday, the government announced a plan to begin releasing the water in about two years.

The plant's operator, TEPCO, will filter the water to remove harmful radioactive isotopes.

Prime Minister Yoshihide Suga again made his country's argument that the water must be released to decommission the Fukushima plant.

"We will secure safety which is far above the regulation standards, and the government as a whole will conduct exhaustive measures against harmful rumours. We've judged that oceanic release is a realistic (option)."

One isotope that has sparked anxiety is called tritium, as it is difficult to separate from water.

However, it is considered to be relatively harmless because it does not emit enough energy to penetrate human skin.

Suga says that even still, its concentration in the water Japan dumps would be reduced to around one-seventh of the drinking water standard defined by the World Health Organisation.

Other plants around the world routinely pump water with lows levels of tritium into the ocean.

But local fisherman have opposed dumping the water for years.

And neighbours aren't happy either.

China called the move 'extremely irresponsible' on Tuesday, and spokesman for South Korea called the decision unacceptable.

Japan has been working closely with the International Atomic Energy Agency since the meltdown.

Despite the outrage, the government has pointed out there is simply no more room at the site in the huge tanks that hold waste water.

The Japanese government has been keen to stress the filtering and dilution processes.

A senior government spokesperson emailed media outlets on Monday to request the term "contaminated" not be used in reporting, arguing it was misleading.