Environmental groups are skeptical of a Japanese government declaration claiming that contaminated water stored at the crippled Fukushima nuclear plant is safe to release into the ocean.

Officials from the Ministry of Economy, Trade and Industry addressed a government committee Monday, and said that the health risk associated with releasing water that absorbed radionuclides in the aftermath of the March 2011 nuclear accident would be "small."

During the hearing, the officials said that releasing the water over the course of one year would cause exposure amounting to a miniscule fraction of the radiation that humans are naturally exposed to annually. 

The officials said that storage facilities are already close to capacity, with over 1 million tons of contaminated water being stored in steel tanks on the site in northeast Japan.

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Tokyo Electric Power Company (TEPCO), the operator of the Fukushima plant, estimates that with around 120 tons of ground water leaking into the basement levels of the three reactors that suffered meltdowns as a result of the 2011 earthquake and tsunami, the storage tanks will reach capacity in the summer of 2022. 

Contamination questions

TEPCO and the government have long believed that the best way to dispose of the water is to simply release it into the ocean. They claimed until this year that contaminated water had been cleansed by a so-called advanced liquid processing system to the point that virtually all the radionuclides had been reduced to "non-detect" levels. 

Leaked TEPCO documents, however, show that varying amounts of 62 radionuclides — including strontium, iodine, cesium and cobalt — have not been removed from the water. 

The company has also been criticized for refusing to permit independent organizations to test the water that is being stored at the site.

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Nevertheless, environmentalists fear that preparations are under way to release the water into the environment. 

"Even a year ago, when the first report on options for disposing the treated water was presented to the committee, it seemed clear to me even then that the preferred option was to release it into the ocean," said Azby Brown, the lead researcher for Tokyo-based nuclear monitoring organization Safecast Japan. Other options included evaporation and burying the water.

"My take on this is that they have already reached a decision and that all these discussions now on the options are purely theater."

Calls for added storage capacity

Safecast, Greenpeace and other environmental organizations have called for the company to build more tanks on the site. Additionally, when the area within the plant perimeter is full, they advocate building more storage on adjacent farmland that can no longer be used because it is too highly contaminated.

Brown said TEPCO officials ruled that option out on the grounds that they want to limit the tanks to the existing site. 

"Honestly, I don't see much evidence of genuine consideration of the other options," he said.

Others are more optimistic that the government and TEPCO will eventually conclude that it would be too damaging to their reputations to dump the water into the Pacific. 

"They do seem to be coming back to this option regularly, but once you start to look at the logistics of it, very quickly it's clear that it's virtually impossible," said Hideyuki Ban, co-director of the Citizens' Nuclear Information Center. 

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"We do not know the levels of radionuclides in the water they say has been treated, but the best guess we have is that levels of tritium are at about 1 million becquerels per liter," he said.

"The government has set a level of 60,000 becquerels per liter as the target before the water is released, but TEPCO says they want to get it down to 1,500 becquerels."

"To do that is going to take a long time, and then every tank of water that was going to be released would have to be tested to make sure that it meets those standards," Ban said. "We think that they would be better off just deciding to keep storing the water for the next 30 years."

The best of bad options?

TEPCO said that a final decision on how to dispose of the water will be made by the government after all the available options have been taken into consideration.

But a company official told DW that time is running out for a decision to be made.

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"In three years, the capacity that we are adding at the site at the moment will be used up and there is nowhere else to build tanks," he said. "We have a three-year window for the government to decide on a policy and a course of action."