Advanced detritiation technology could solve waste water problem
Laker TRF testing identifies efficiencies that could resolve Fukushima storage issue.
Canadian company Laker TRF, a subsidiary of Laker Energy Products Ltd., says that its water detritiation technology could solve decontamination and decommissioning problems at nuclear plants like Fukushima Daiichi and Savannah River Nuclear Laboratory, reducing tritium concentrations to levels below naturally occurring rainwater.
This would allow safe release into oceans, as well as supplying the entire global demand of the stable medical isotope oxygen-18, which is produced as a by-product of the process.
Just last month, Japanese environment minister Yoshiaka Harada said Tokyo Electric Power Co (TEPCO) would have to dump one million tons of contaminated water into the Pacific Ocean which has been collected from the destroyed Fukushima plant since it was hit by an earthquake and tsunami in 2011. TEPCO said it will run out of storage space for the water by 2022.
Laker TRF’s Advanced Water Distillation (AWD) technology was originally developed for pressurized heavy water reactors but it says could provide “cost-effective and reliable” detritiation for light water applications.
“AWD can be used to detritiate decommissioned heavy water from heavy water reactors, and also to recover tritium from light water reactors and spills of tritiated water,” Laker TRF Sales Director Cameron Nevay told Nuclear Energy Insider.
“For example, the United States has several thousand tons of tritiated heavy water from decommissioned heavy water reactors at Savannah River Nuclear Laboratory that could be detritiated to convert a liability into an asset.”
AWD is compact and more energy efficient, making practical tritium recovery from water, which was previously considered impractical. Tritium releases to the environment can be reduced, and large volumes of tritiated water liability can be safely dealt with.
“AWD is more compact than existing water distillation technology which makes AWD now cost effective versus competing technologies,” said Nevay.
“AWD is up to 80% more energy efficient than existing processes, which employ very complex processes, and in some cases, had very poor operating capacity. AWD is a very simple process, requiring minimal maintenance, and has the benefit of producing a life-saving medical isotope.”
A test plant has been operating in Oakville, Ontario, Canada since 2018. A larger, multi-column test plant will be built in Cambridge, Ontario next year.
Laker says its AWD technology uses the latest advancements in water distillation equipment design and configuration. In testing it has already achieved a five-fold equipment height reduction. The process operates under benign conditions of purified warm water under vacuum, which eliminates the chance of leakage and associated environmental emissions.
Veolia in the race
Veolia Nuclear Solutions – who specialize in nuclear facility clean-up and treatment of radioactive waste – has also developed a patent-pending Modular Detritiation System (MDS). This technology is based on the principle of combined electrolysis catalytic exchange (CECE) and releases only clean oxygen and hydrogen with no liquid effluent.
The technology builds on proven heavy water solutions, and although developed with a focus on light water, it can also be adapted for use in heavy water detritiation. Veolia’s tritium facility in Richmond, Washington, was constructed and commissioned in five months.
Water detritiation is hydrogen isotope separation, exploiting small differences in chemical or physical properties of substances containing the mass 1, 2 and 3 hydrogen isotopes, referred to as H, D and T.
“In water distillation, small differences in vapor pressure of different isotopologues (H2O, HDO, HTO, D2O and DTO) is used to separate the hydrogen isotopes,” explains Laker’s Nevay. “The vapor pressure difference between H2O and HTO is five times greater than the vapor pressure difference between D2O and DTO, making recovery of tritium from light water five times as efficient.”
Nuclear plants commonly dump water into the ocean that contains tritium, as it is hard to separate and considered to be relatively harmless as it occurs naturally.
TEPCO recently admitted that water stored at Fukushima still contains contaminants beside tritium.