Japan has started pumping treated nuclear waste water into the Pacific Ocean. It is the start of a plan to release contaminated water from a nuclear accident in 2011.
The United Nations signed off on the move in July, but critics have raised concerns about its safety.
Here’s what you need to know.
How did we get here?
The water became contaminated after an earthquake and tsunami hit the Fukushima nuclear power plant in 2011.
Over 15,000 people are believed to have died across the region from the natural disaster.
The tsunami cut the power supply to the plant, triggering a chain reaction that caused its reactor cores – the heart of the nuclear plant – to meltdown. The water to cool the reactor cores (500 Olympic-sized pools’ worth of water) became highly contaminated.
Dumping the nuclear waste water
Japan has been storing that radioactive water in tanks ever since and officially made the decision to release it into the Pacific Ocean in 2021.
To meet safety standards, Japan diluted the contaminated water to remove all but one radioactive chemical called tritium.
The concentration of the tritium in the dumped water is seven times below the recommended amount for safe drinking water.
The dumping process began this week, and authorities expect it to take about 30 years to complete.
How safe is it?
Japan’s Nuclear Regulation Authority and the UN’s International Atomic Energy Agency (IAEA) signed off on the plans earlier this year.
The IAEA found in July that the dumping met international safety standards, and the practice would have a “negligible radiological impact” on people and the environment.
They plan to continue monitoring the dumping as it is released. The water will be released away from popular fishing areas and about one kilometre from the Japanese coastline.
Foreign opposition
The Chinese Government has accused Japan of not sufficiently proving the safety of the dumping. A spokesperson said it infringes upon “people’s rights to health, development and a healthy environment”.
Japan exported $US600 million of seafood to China in 2022. China blocked future imports in response to the dumping.
There have also been protests in South Korea. One group of protesters were arrested after attempting to enter the Japanese embassy in Seoul, South Korea’s capital. North Korea, through state media, have also criticised the dumping.