Japan releases treated Fukushima nuclear power plant water into the sea

Tokyo — The Government of Japan decided on Tuesday to begin releasing large amounts of treated radioactive water into the Pacific Ocean from the destroyed Fukushima nuclear power plant within two years. This is an option that has been strongly opposed by local fishermen and residents.

The decision, which had long been speculated but was postponed for years due to security concerns and protests, was made at a ministerial meeting that approved the liberation of the ocean as the best option.

The accumulated water has been stored in the tanks of the Fukushima Daiichi Nuclear Power Station since the 2011 earthquake and tsunami damaged the reactor and the cooling water was contaminated and began to leak.

The factory operator, TEPCO, said it would fill up its storage capacity later next year.

Prime Minister Yoshihide Suga said ocean release is the “most realistic” option and that it is “unavoidable” to dispose of water in the decommissioning of the Fukushima plant, which is expected to take decades.

Yoshihide Suga
Prime Minister Yoshihide Suga (left) will attend a cabinet meeting held at the official residence in Tokyo on April 12, 2021.

TEPCO and government officials say that tritium, which is not harmful in small amounts, cannot be removed from water, but all other selected radionuclides can be reduced to levels that are allowed to be released. Some scientists say the long-term effects of such low-dose exposures to large amounts of water on marine life are unknown.

TEPCO plans to start water discharge about two years after constructing the facility based on the safety requirements of the regulatory authorities based on the basic plan adopted by the ministers. The disposal of water cannot be postponed any longer, and the environment around the factory needs to be improved so that residents can live safely.

According to TEPCO, the storage capacity of 1.37 million tons will be full by the fall of 2022. Also, the area currently filled with storage tanks must be released to build new facilities needed to remove melted fuel debris from the interior. Reactor, a process scheduled to begin in the next few years.

Japan Nuclear Fukushima Water
The Fukushima Daiichi Nuclear Power Station can be seen from Namie Town, Fukushima Prefecture, in northern Tokyo on April 13, 2021. (Yusuke Ogata / via Kyoto News AP)

During the decade following the tsunami disaster, water to cool nuclear material constantly escaped from the damaged primary containment vessel into the basement of the reactor building. To make up for the loss, more water is pumped into the reactor to keep the molten fuel cool. Water is also pumped and processed, some of which is recycled as cooling water and the rest is stored in 1,020 tanks, which currently hold 1.25 million tonnes of radioactive water.

Minister of Economy, Trade and Industry Hiroshi Kajiyama said these tanks, which occupy a large space in the plant complex, hinder the safe and steady progress of decommissioning. According to the report, tanks can also be damaged and leak in the event of another strong earthquake or tsunami.

Discharging water into the sea is the most realistic method explained by a government committee that has been discussing for about seven years how to dispose of water without further damaging Fukushima’s image, fisheries and other businesses. it was done. A report produced last year states that evaporation is a less desirable option.

According to the report, about 70% of the water in the tank exceeds the permissible emission limits for pollution, but it is refiltered, diluted with seawater and then released. According to tentative estimates, the gradual release of water will take about 30 years, but will be completed before the plant is completely decommissioned.

Japan said it would comply with international regulations on emissions and, with the support of the International Atomic Energy Agency and others, ensure data disclosure and transparency in order to gain the understanding of the international community. China and South Korea have expressed serious concern about water emissions and their potential impact.

The government said it would do its best to support the local fishery, and the report said TEPCO would compensate for the damage if it occurred despite those efforts.

Kajiyama will visit Fukushima on Tuesday afternoon to meet with local towns and fisheries authorities to explain the decision. He said he would continue to work to gain their understanding over the next two years.

Mari Yamaguchi