A new recycling plant will soon recover uranium from the ashes of radioactive garbage to be recycled back into nuclear fuel using an efficient, environmentally friendly technology inspired by decaffeinated coffee. The technique may eventually lead to recycling the most dangerous forms of radioactive waste. Developed at the University of Idaho by chemistry professor Chien Wai, the process uses supercritical fluids to dissolve toxic metals. When coupled with a purifying process developed in partnership with Sydney Koegler, a university alum and engineer with nuclear power company AREVA, enriched uranium can be recovered from the ashes of contaminated materials. The school signed an agreement with AREVA last week under which the company will use several of Wai’s discoveries to extract the metals from contaminated ash. AREVA provided research funding and will now gain rights to the university’s share of a joint patent that further separates the enriched uranium from the extracted metals.

A supercritical fluid — in this case carbon dioxide — is any substance raised to a temperature and pressure at which it exhibits properties of both a gas and a liquid. When supercritical, the substance can move directly into a solid like a gas and yet dissolve compounds like a liquid. Supercritical carbon dioxide has directly dissolved and removed caffeine from whole coffee beans for decades, Wai noted. When the carbon dioxide’s pressure is returned to normal, it becomes a gas and evaporates, leaving behind only the extracted metals. No solvents are required, no acids are applied, and no organic waste is left behind. “That’s why decaffeinated coffee tastes so good,” said Wai. Because the technology is so simple, cost-effective and environmentally friendly, AREVA is eager to test its first full-scale use on 32 tons of incinerator ash at a nuclear fuel fabrication plant in Richland, WA. During normal operation at the plant, common items including filters, rags, paper wipes, and gloves become contaminated with uranium. The waste is burned to reduce its volume and increase its uranium content, making it easier to recover the uranium. Nearly 10% of the ash’s weight is usable enriched uranium, worth about $900 dollars per pound on today’s market. That means about $5 million dollars is currently sitting in the garbage waiting to be recovered, Wai said. “This process has been extremely collaborative — it’s one of those [deals] that you just love,” said Gene Merrell, the university’s chief technology transfer officer and assistant vice president for research. “It’s going to be a great deal that will benefit the University of Idaho, AREVA and the entire world.” Go to: 123 Idaho

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