K-65 residues

K-65 residues are the very radioactive mill residues resulting from a uniquely concentrated uranium ore discovered before WW II in Katanga province (Shinkolobwe) of the Democratic Republic of the Congo (formerly called the Belgian Congo).

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This ore, dubbed "K-65", had a record 65% uranium content. It also held very high concentrations of thorium and radium (and their decay products, including radon gas) which are retained in the tailings (residues). The very high concentrations of these extremely toxic, long-lived radionuclides present in these wastes prompted the National Academy of Sciences' National Research Council to categorize them as indistinguishable in hazard from High-Level Waste in its 1995 report, "Safety of the High-Level Uranium Ore Residues at the Niagara Falls Storage Site, Lewiston, New York" [1]. The K-65 ores were refined as a key part of the Manhattan Project during World War II at the Linde Ceramics Plant at Tonawanda, NY, and at the Mallinckrodt Chemical Works in St. Louis, MO; these ores were the primary raw material source of ~80% of the uranium used in the Hiroshima bomb. The Mallinckrodt "K-65 residues" were later moved to a huge, new, Cold War uranium refinery at Fernald, OH (outside of Cincinnati) which commenced operations in 1951. The refining of "K-65" ore was continued at Fernald. The Linde "K-65 residues" were transported to a storage silo built at the federally appropriated Lake Ontario Ordnance Works site outside of Lewiston, NY, a short distance from Niagara Falls, NY.

References

• Tonawanda Nuclear Site Info glossary