The Department of Energy (DOE) established the Idaho
National Laboratory (INL) in Idaho Falls, Idaho and three
gaseous diffusion plants (GDP) at: the K-25
Complex at Oak Ridge, Tennessee; the Paducah
Gaseous Diffusion Plant in Paducah, Kentucky; and the Portsmouth
Gaseous Diffusion Plant in Portsmouth, Ohio. At each of the
GDPs, uranium hexafluoride gas (UF6) was "enriched";
meaning the relative amount of uranium-235 isotope was increased.
This was accomplished by moving UF6 through a multi-stage series
of porous membrane "barriers." This enriched UF6 was
a necessary ingredient in nuclear weapons production and is now
used in the civilian nuclear power industry.
In 2003, the Worker Health Protection Program added two new medical screening sites to its program: the Oak Ridge National Laboratories (ORNL) and Y-12 in Oak Ridge, Tennessee. Two years later, two closure sites were added to WHPP: Fernald in Harrison, Ohio and Mound in Miamisburg, Ohio. In 2011, the Nevada Test Site (NTS), Lawrence Livermore National Lab (LLNL), Lawrence Berkley National Lab (LBNL), and Sandia/CA National Lab were added, bringing the total number of sites to thirteen.