National

Fukushima nuclear plant to run out of tanks to store tritium-laced water in three years, Tepco says

by Kazuaki Nagata

Staff Writer

Tokyo Electric Power Company Holdings Inc. on Friday projected that the storage tanks for the treated contaminated water at its Fukushima No. 1 nuclear plant would reach full capacity in three years despite plans to expand storage space, complicating the government’s efforts to tackle the build-up.

Despite the dwindling storage space, a government committee tasked with deciding what to do with the treated water build-up said at a meeting it would consider sticking with holding the water at the facility for the foreseeable future due to strong objections from residents to discharging it into the sea.

During the meeting, Tepco projected that storage would reach full capacity by around summer 2022 even after the expansion — the first time it has issued such a precise estimate.

According to Tepco, the Fukushima No. 1 plant had 960 massive tanks containing 1.15 million tons of treated water as of July 18. Water that has touched the highly radioactive melted fuel debris has been cleaned up through water treatment machines and is stored in the tanks, but the high-tech treatment machines are able to remove most radionuclides except tritium. The plant currently sees an increase of contaminated water by 170 tons a day, Tepco says.

Releasing tritium-tainted water into the sea in a controlled manner is common practice at nuclear power plants around the world, and it was generally considered the most viable option as it could be done quickly and would cost the least.

The head of the Nuclear Regulation Authority, Toyoshi Fuketa, has long said that releasing the treated water into the sea is the most reasonable option, but people in Fukushima, especially fishermen, fear it will damage the region’s reputation.

Addressing those concerns, the government panel, launched in November 2016, has been looking for the best option in terms of guarding against reputational damage. Injecting it into the ground, discharging it as steam or hydrogen, or solidification followed by underground burial have all been on the table. Under the current plan, Tepco is set to increase the tank space to store 1.37 million tons of water a total, but estimates show that will only last until summer 2022.

But the more space it creates, the bigger the decommissioning headache becomes.

Tepco claims that if the number of tanks continues to swell, that could slow the progress of other tasks necessary for scrapping the plant, which was hit by a monstrous quake and tsunami in March 2011 that led to the triple core meltdown.

The utility, for instance, says the site will need as much as 81,000 sq. meters of space to store any melted fuel debris that is successfully retrieved, in addition to spent fuel rods. That’s enough space to build new tanks that can store about 380,000 tons of water, Tepco says. Some committee members said it is reasonable to consider the new storage option given the residents’ concern but added that neither the water nor the tanks can stay forever. “As the decommissioning work will move forward, some space is needed to build the necessary facilities. Whether (the tanks) will eat up so much space that it drags down the decommissioning work needs to be considered,” said Tokuhiro Yamamoto, a committee member and executive director at the Japan Atomic Energy Agency.

He added that if the committee endorses the storage plan, it will also need to set some conditions to end it.

Some other committee members asked if it would be possible to expand the plant’s area to secure more storage space. Tepco said that would be very difficult because it would require contract renegotiations between the government and local landowners.