By SCOTT SONNER
Associated Press

RENO, Nev. (AP) - The U.S. Energy Department has suspended shipments of low-level radioactive waste from Tennessee to Nevada while it investigates whether the materials were being mislabeled and shipped out of compliance with state or federal regulations for several years.

Department spokeswoman Shaylyn Hynes said in a statement Wednesday that none of the materials shipped as early as 2013 from the Y-12 facility in Tennessee posed any health or safety threats to workers or the general public.

But she said the shipments slated for disposal at the Nevada National Security Site north of Las Vegas were not in compliance with the site's acceptance criteria and were "potentially mischaracterized" as the wrong category of low-level waste for years.

She says the department's National Nuclear Security Administration has launched an internal investigation "to determine how this went undetected" for up to six years.

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