Treated water release from Fukushima Daiichi nuclear plant starts

Tokyo Electric Power Company has started to release treated and diluted water from the Fukushima Daiichi nuclear power plant into the ocean.

Japan's government says it is a necessary step to decommission the plant, more than 12 years after it was devastated by an earthquake and tsunami.

Before the release, the plant's operator said it was ready to move forward after confirming the water's dilution had been carried out as planned.

TEPCO analyzed the concentration of tritium, which is measured in units called "becquerel." It found the diluted water contained between 43 to 63 becquerels per liter. That is far below Japan's environmental release standards of 60,000 becquerels per liter.

Fukushima Daiichi suffered a triple meltdown in 2011. Since then, water used to cool molten fuel at the plant is mixing with rain and groundwater and the volume has been accumulating.

The water is treated to remove most radioactive substances, but still contains tritium. Before the release, the operator is diluting the treated water to reduce tritium levels to about one-seventh of the World Health Organization's guidelines for drinking water.

The water will then be sent through a tunnel under the seabed and discharged one kilometer off the coast. The first round of the process will take around 17 days, and involve the release of about 7,800 tons of treated water.

The full process is expected to take at least thirty years. Members of local industries have voiced concern over how the release will impact their business. The government has promised to work hard to prevent any reputational damage.