On March 11, 2011, a 9.0-magnitude earthquake off the Pacific coast of Japan caused a powerful tsunami near the Fukushima Daiichi Nuclear Power Plant. Water from the overwhelming tsunami waves accumulated in the plant’s sub-basement, triggering meltdowns in three reactors. It threatened to overflow the site and discharge radioactive wastewater into the Pacific Ocean.
With a 20 kilometer exclusion zone and more than 350,000 people displaced, Fukushima immediately became the largest nuclear accident since 1986’s Chernobyl disaster in Russia. It is only the second site to receive the International Atomic Energy Agency’s highest classification for nuclear accidents.
Honeywell UOP Adsorbents Are the Right Solution
When the initial water treatment system implemented at Fukushima was not able to remove radioactive contaminants quickly enough, Honeywell UOP and a consortium of U.S. companies, in partnership with the Japanese companies overseeing the site, were brought in to provide a back-up system that would supplement these efforts. This system ended up cleaning the water to higher purities while generating less waste, so it became the primary treatment system.
Honeywell UOP pioneered the adsorbents industry more than 60 years ago with the invention of the first synthetic zeolites for use as molecular sieve adsorbents. When the company was initially approached to help clean Fukushima’s water, it had been more than 15 years since it had produced the types of adsorbents that were needed. For a project as large as Fukushima, Honeywell had to update its production recipes, identify new raw material suppliers, and re-develop test procedures for the new adsorbents—all in less than eight weeks.
An adsorbent works by selectively removing ions, atoms, and molecules from different types of substances. For Fukushima, Honeywell utilized its UOP IONSIV™ Selective Media
adsorbents to identify and remove radioactive ions from the water—specifically cesium and strontium, two elements that accounted for almost 95 percent of the radioactive contaminants in the water—until the amounts were reduced to levels safe for storage.
100 Million Gallons Cleaned in the First Two Years
By 2013, Honeywell adsorbents had cleaned more than 100 million gallons of radiation-contaminated water at Fukushima. The treated water was continuously used to cool Fukushima’s reactors, after which it was cleaned again. When it wasn’t being re-used, extra water was stored in large storage tanks so that it would not spill into the ocean.
In April 2013, Honeywell UOP was a co-recipient of the Federal Laboratory Consortium’s prestigious National Award for Excellence in Technology Transfer
. The award recognized the company’s round-the-clock efforts to help clean cesium-contaminated seawater at the plant, including providing technical expertise to ensure the adsorbents’ optimal performance.
More Uses for Honeywell Adsorbents
According to the most recent data from the Tokyo Electric Power Company (TEPCO), which is overseeing the Fukushima clean-up, more than 300 million gallons of water have been cleaned of radioactive material, and Honeywell UOP adsorbents are expected to remain in use for the next 10 years.
They won’t be cleaning just stored water, either.
Situated between the mountains and the Pacific Ocean, Fukushima must carefully monitor rainfall, which comes down from the mountains toward the plant, where it picks up radioactive contaminants from the ground and threatens to discharge into the ocean. To prevent this, Honeywell UOP’s adsorbents will be used in Fukushima’s aquifer system to help remove radioactive elements from the rainwater before they can reach the Pacific.
The Fukushima disaster has prompted stricter regulations on not only water, but also air emissions at nuclear plants all over the world. Honeywell’s work in removing radioactive elements from water has led to the development of new adsorbents that help perform a similar filtration of radioactive ions from steam by capturing iodine emissions from nuclear vents. Honeywell is working to implement these air adsorbents in Asia and Europe.
The adsorbents used at Fukushima have helped clean millions of gallons of water, preventing radioactive elements from contaminating water supplies beyond the site. Though estimates vary on how long the overall cleaning efforts will take, it is comforting to know that something as small as a Honeywell adsorbent can make a world of difference.