A new plant will help* *recover uranium from the ashes of radioactive wastes, which can then be recycled with an efficient, ecoe- friendly green technolog.  Over the course of 20 years, Chien Wai, a University of Idaho chemistry professor, has developed a process that uses supercritical fluids to dissolve toxic metals. When coupled with a purifying process developed in partnership with Sydney Koegler, an engineer with nuclear industry leader AREVA, a French nuclear energy company, Enriched uranium can be recovered from the ashesof contaminated materials.

On Wednesday, Aug. 20, 2008, representatives from Areva and the University of Idaho signed an agreement in Moscow, Idaho, to share the technologies and pave the way for the recycling plant’s construction in Richland, WA. “Radioactive waste is a big problem facing the United States and the entire world,” said Wai. “We need new, innovative technology, and I think supercritical fluid is one such technology that will play an important role in the very near future.” 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. For example, says Wai, supercritical carbon dioxide has directly dissolved and removed caffeine from whole coffee beans for decades. When the carbon dioxide’s pressure is returned to normal, it becomes a gas and evaporates, leaving behind only the extracted metals. No solvents required, no acids applied, and no organic waste left behind. 

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 in Richland, Wash.The existing plant in Richland

fabricates fuel for commercial nuclear power plants from raw enriched uranium supplied by utility customers as uranium hexafluoride (UF6). During normal operation, 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 percent of the ash’s weight is usable enriched uranium, worth about $900 dollars per pound on today’s market. This means about $5 million dollars is currently sitting in the garbage waiting to be recovered. The process may even become the basis of the next generation of plants designed to recover useful materials from spent fuel.

The new recycling plant is expected to be

operational in 2009 and will take about a year to process AREVA’s ash inventory. When finished, much of its operating time can be devoted to ash received from other sites.