2 February, 2015
U.S. Kurion to Verify Tritium Separation at Fukushima Daiichi
The Tokyo Electric Power Co. (TEPCO) is currently attempting to use multi-nuclide removal equipment — known as ALPS, or Advanced Liquid Processing System — to remove 62 nuclides from contaminated water generated at its Fukushima Daiichi Nuclear Power Station (NPS), but the results have not been totally successful. Dealing with tritium remains an issue.
Approximately 270,000 tons of highly contaminated water is currently stored in tanks erected above ground at the site.
Kurion Inc. of the United States, which developed and installed the cesium absorption devices and mobile systems used to treat strontium at the NPS, has developed new technology to remove the tritium. The equipment has now been adopted by Japan’s Ministry of Economy, Trade and Industry (METI) for a demonstration project for verification tests of tritium separation technology.
Existing technology to remove tritium is quite expensive, and has usually been applied to highly contaminated heavy water. On the other hand, Kurion’s Modular Detritiation System (MDS) is designed to decontaminate light water, similar to the tritium-containing water at the Fukushima Daiichi NPS, in an economic way.
In the system, tritiated water is first electrolyzed into two components: pure oxygen and hydrogen-tritium. Next, all the hydrogen-tritium is sent to an original column, where normal hydrogen is extracted until only the tritium remains. The cost advantages in terms of construction, operation and stable storage of the removed tritium have already been proven.
Kurion will complete the MDS through the demonstration project, after which it wants to begin operating at the NPS as soon as possible, including delivering necessary data during FY15, which begins in April.
On January 23, TEPCO indicated that it would be difficult to treat all contaminated water at the Fukushima Daiichi, using ALPS and other methods, by the end of the current fiscal year, which is March 31.
At the station, contaminated water has been treated so far with three types of ALPS systems: existing, additional and advanced. It has become technologically difficult, however, to achieve the availability factors initially assumed.
TEPCO will take additional steps, including improving equipment and devices and adjusting their operation. It expects to complete the treatment in mid-May at the current pace.