Paducah
Gaseous
Diffusion
Plant

What is the Paducah Gaseous Diffusion Plant?

The U.S. Department of Energy’s (DOE) Paducah Gaseous Diffusion Plant (PGDP), located in far Western Kentucky, was the last government uranium enrichment facility operating in the country.  The now-antiquated gaseous diffusion process was used for uranium enrichment at the PGDP.  The process required the production of uranium in a gaseous form, uranium hexafluoride, and the physical separation of “less than one percent” quantities of the desired uranium-235 isotope from the abundantly plentiful uranium-238 isotope – accomplished at the scale of an atom.

Plant operations began in 1952 as the initial uranium enrichment step to produce material for Cold-War weapons development and an emerging nuclear power industry. Enrichment operations were the Plant’s primary mission and required the construction of expansive ‘Process’ buildings to house the massive equipment the gaseous diffusion process required. The Plant also required the construction and long-term maintenance of extensive water, power, cooling and physical support infrastructure. At the time of its construction, the C-333 Process Building was one of the largest man-made structures in the world enclosing over 90 million cubic feet compared to the Empire State Building which encloses 37 million cubic feet.

In the early 1950s more than 29,000 construction workers and tradesmen were employed in the construction of the PGDP and two nearby power plants needed to satisfy the PGDP’s electricity needs. From the early 1950s until shutdown of enrichment operations in May 2013, the PGDP employed an average of 1,700 skilled workers to manage, operate, upgrade and maintain the enrichment operations, implement plant decontamination and decommissioning, and conduct environmental restoration activities.

The Paducah plant produced low-enriched uranium which was further enriched and processed at the Portsmouth Gaseous Diffusion Plant in Piketon, Ohio and the K-25 plant in Oak Ridge, Tennessee. In the 1960s the Paducah plant was dedicated to uranium enrichment for nuclear power plants. Depleted uranium, a by-product of the enrichment process, is stored at the PGDP for re-enrichment, recycling or disposal and comprises the largest stockpile of mined uranium in the world.

The Need for Uranium

In 1938, physicists in Berlin successfully split a uranium atom, opening the scientific world to the possibility of nuclear fission and atomic weapons that harness nuclear fission for its potential to release energy. Some physicists who had fled Europe, including Leo Szilard and Albert Einstein, recognized the dangers of atomic weapons, especially if Nazi Germany were to develop them before the rest of the world. With Szilard’s help, Einstein wrote a letter to President Roosevelt warning him of the possible Nazi nuclear dangers which led to the creation of the secret Uranium Committee in 1939. In 1942, the Committee became the Manhattan Project.

The Manhattan Project, led by Col. Leslie Groves and physicist Robert Oppenheimer, pursued two paths toward the creation of an atomic super weapon: a uranium bomb and a plutonium bomb. Large amounts of refined uranium ore had to be processed and enriched in order to create the necessary forms and quantities of enriched uranium and plutonium for the bombs.

To accomplish uranium enrichment three isotope separation processes, electromagnetic separation, liquid thermal diffusion, and gaseous diffusion were conducted at facilities in Oak Ridge, Tennessee. Plutonium was produced at Manhattan Project facilities in Hanford, Washington. Both uranium and plutonium paths achieved the goal of producing bombs by 1945. The Atomic Age began with a successful test of the “Gadget” carried out near Los Alamos, New Mexico, followed by the bombings of the Japanese cities of Hiroshima and Nagasaki which prompted the end of World War II.

The Cold War began shortly after the end of World War II with several world powers advancing their nuclear arms capabilities. In 1949, The Soviet Union successfully detonated its first atomic weapon marking the onset of a worldwide nuclear arms race.

In June 1950, North Korean forces, supported by Soviet machinery and munitions, crossed the 38^th parallel and invaded South Korea igniting the Korean War. After North Korean forces nearly drove U.S.-led forces off the Korean peninsula, U.N. forces joined the U.S. and quickly staged a successful campaign pushing to the Yalu River at the North Korea-China border. In response, Chinese forces massed the first in a wave of attacks on the Korean peninsula and drove U.S.-backed U.N. and South Korean forces south of the 38^th parallel.

Because of threats posed by nuclear proliferation and an ongoing Korean conflict, the Government decided that additional material was needed to expand the U.S. nuclear arsenal. A decision was made to expand K-25’s production capabilities with additional uranium plants.

What is Gaseous Diffusion?

In order for uranium's energy to be harnessed for weapons or fuel, the concentration of the uranium-235 isotope must be increased relative to its natural concentration. The process of increasing the concentration of the uranium-235 isotope in uranium is known as ‘enrichment’.

Why Paducah?