Japan releases water from Fukushima nuke plant China furious

Japan began releasing wastewater from the crippled Fukushima nuclear plant into the Pacific Ocean yesterday, prompting a furious China to ban all seafood imports from its neighbour.

The start of the discharge of around 540 Olympic swimming pools' worth of water over several decades is a big step in decommissioning the still highly dangerous site 12 years after one of the world's worst nuclear accidents.

Live video provided by plant operator TEPCO showed two engineers clicking on computer mouses and an official saying -- after a countdown -- that the "valves near the seawater transport pumps are opening".

Japan has repeatedly insisted the wastewater is treated and will be harmless, a position backed by UN atomic watchdog the International Atomic Energy Agency (IAEA).

The IAEA said yesterday that new on-site tests had confirmed the levels of radioactive tritium in the water being discharged were safe.

But China has warned the release will contaminate the ocean, and immediately responded yesterday by blasting Japan as "extremely selfish".

It then banned all Japanese seafood imports "to comprehensively prevent the food safety risks of radioactive contamination" -- with Japan hours later demanding China lift the ban.

North Korea's foreign ministry likewise criticised the release, urging Japan to call it off.