Japan plans to release radioactive water from Fukushima nuclear plant into the sea this year

Japan is planning to release one million tonnes of radioactive water into the sea this year.

The waste-water is to be discharged from a Fukushima nuclear power plant, to north of Tokyo, in spring or summer.

The government and plant operator Tokyo Electric Power Company Holdings (TEPCO) say there is about 1,000 tanks of radioactive water at the plant, which are at risk of leaking if there is a major earthquake or tsunami.

The water was collected after a massive earthquake and tsunami in 2011 destroyed the plant’s cooling systems.

This caused three reactors to melt and release large amounts of radiation.

Water used to cool the damaged reactor cores, which became highly radioactive, leaked into the basements of the reactor buildings. This was then collected, treated and stored in tanks.

The release plan has been fiercely opposed by fishermen, local residents and Japan’s neighbours, including China and South Korea.

Fukushima residents worry the reputation of their agricultural and fishing products will be further damaged.

When the plan was first announced in April 2021, the water was to be released in spring 2023, but this has been delayed to 'spring or summer'.

The hold-up has come due to slow progress on creating a release tunnel and the need to gain public support.

Why does Japan want to release radioactive water?

Under the current plan, TEPCO will transport the radioactive water through a pipeline from the tanks to a facility at the coast.

Here, it will be diluted with seawater and sent through an undersea tunnel, which is being built, out into the ocean. The company says, the possibility of rough winter weather and sea conditions may delay the tunnel building works.

Most of the radioactivity is removed from the water during treatment, but tritium cannot be removed and low levels of some other radionuclides also remain.

What could the impact be?

The government and TEPCO say the environmental and health impacts will be negligible as the water will be slowly released after further treatment and dilution by large amounts of seawater.

Some scientists say the impact of long-term, low-dose exposure to tritium and other radionuclides on the environment and humans is still unknown and the release plan should be delayed. They say tritium affects humans more when it is consumed in fish.

Chief Cabinet Secretary Hirokazu Matsuno said the government has revised the plans, enhancing efforts to ensure safety and measures to financially support the local fishing industry.

TEPCO President Tomoaki Kobayakawa said despite the government’s later timing for the wastewater release, his company still aims to have the facility ready by the spring.

He also acknowledged a lack of local understanding about the release and pledged to continue efforts to reduce safety concerns.

Japan is cooperating with the International Atomic Energy Agency ( IAEA) to increase the safety, transparency and understanding of the water discharge plan.

An IAEA team that visited Japan a number of times for talks and plant inspections last year will visit again in January to meet with nuclear regulators and will release a final report before the planned release begins.

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