Radium-226, discovered in 1898 by Marie Sklodowska-Curie and Pierre Curie, was formerly used in radiotherapy but has since been replaced by other sources.
The changes made last year by the Conservatives were aimed at boosting recycling rates but sparked complaints and an independent councillor claimed festering waste was putting public health at risk.
Research by Global Energy Monitor finds significant low-carbon investments worldwide but ongoing commitment to coal- and ore-intensive blast furnace production in China and India.
Earlier this week, the company had launched the new facility with a ribbon cutting ceremony, which was attended among others by Chattanooga Mayor Tim Kelly.