The cleanup of Fukushima, the nuclear plant where catastrophe struck after the 2011 tsunami, is progressing about as quickly as a hamster running in a wheel. Every 2.5 days, the site’s owner, TEPCO, fills a new 1,000-ton tank with freshly contaminated groundwater that seeps continuously into the radioactive reactor site.

Ongoing efforts to stem the flow of water from the surrounding hills include building an underground ice wall, but in the meantime, the utility is treating its growing farm filled with hundreds of tanks of radioactive liquid waste. The eventual end goal is to safely dump clean water back into the ocean.





At the center of much of these efforts so far has been Kurion, a venture capital-backed California startup founded in 2008 that’s been involved in the cleanup at the U.S. Department of Energy’s Hanford nuclear waste site in Washington, a former plutonium-making facility that provided fuel for the first nuclear bomb.

Its technology was first used in the early months after the Fukushima disaster, as responders were still struggling to contain the meltdown by pumping in millions of gallons of seawater to cool the reactors. The looming problem was that the plant was quickly filling up with contaminated cooling water that was too radioactive to safely remove. Three months after the tsunami, Kurion rushed to build, test, and install an external system that acted like a molecular sieve to remove the most dangerous radioactive element–cesium–so that water could be pumped outside the reactors and either be reused as cooling water or stored in tanks without endangering workers nearby.

To date, Kurion’s cesium removal system has processed 50 million gallons of water. This weekend, a Russian cargo airplane will deliver another Kurion system that will start to tackle the removal of radioactive strontium, which became the biggest threat after the cesium was treated. By mid-July, the company plans to submit a proposal to the Japanese government to start treating one of the last threats in the holding tanks: tritium, a radioactive form of the water molecule itself, which makes it a much harder contaminant to treat.





“Every pressurized water reactor around the world generates tritium,” says Kurion CEO Bill Gallo. “There has been no technology to capture [it]. Usually, the tritium is allowed to decay and, once it’s below a certain level, the water is released.” Gallo says that Kurion has developed a technology that, to his own knowledge, is the only one that can remove tritium from reactor wastewater, which is preferable to letting it decay to safe levels, since it’s controversial what “safe” levels even mean. So far, Kurion has tested its tritium removal technology at only a pilot scale. If it’s proposal is accepted, it would have its first full deployment at Fukushima, Gallo says.

Once all of these wastes are treated, Kurion is also developing a modular system that vitrifies the contaminated remnant waste, which means turning the waste into stable glass that can last tens of thousands of years. Vitrification technology is already in use around the world, but Gallo says the system the company is developing will be smaller and modular, so it will cost less money to send it to sites. At the Hanford site, Gallo says, it is needed to stem the 56 million gallons of stored wastes that are known to be leaking.