Calutron - Swords to Plowshares story

Pictured is equipment at the Y-12 National Security Complex that helped separate uranium during World War II and other elements following the war that greatly assisted important scientific research.

D. Ray Smith, Y-12 Historian (retired), Oak Ridge City Historian and Commissioner, Tennessee Historical Commission

The Building 9204-3 (Beta 3) Calutrons at the Y-12 National Security Complex, the last remaining full racetrack of Manhattan Project era electromagnetic separation equipment, have received a substantial amount of attention lately. A couple thousand people were allowed to view them during a series of public tours in June, 2005, that were associated with the Secret City Festival. This was the first time ever they have been open to the public. To say the reaction of the visitors who were able to stand where the actual work was done that issued in the Nuclear Age was one of awe is a tremendous understatement.

It all started at an annual labor management prayer breakfast in December 2004 when Oak Ridge Mayor David Bradshaw asked Dennis Ruddy, BWXT Y-12’s president and general manager, if it would be possible to allow the public to see the Beta 3 calutrons during the June 2005 Secret City Festival. It has been the spark that has created a ground swell of historic preservation activities surrounding the Beta 3 calutrons at Y-12. In 2010, members of the National Park Service were also given a tour of the calutrons in Beta 3. And again in November, 2015, when the Manhattan Project National Historical Park was established, public tours were again provided. Beta 3, along with Building 9731 are both designated as facilities of the new national park.

The main feature of the calutrons at Y-12 during the Manhattan Project was their use to separate uranium-235 from the more abundant uranium-238 found in natural uranium. The percentage of uranium-235 in uranium ore is only 0.7%. Separating that scarce material required a specialized process and was highly labor intensive. In August 1945 the workforce at Y-12 peaked at 22,482 people who were working around the clock on calutrons in large buildings to separate approximately 60 kilograms of the extremely rare and valuable material. This was enough uranium 235, and a little left over, for the first atomic bomb, “Little Boy,” that was dropped on Hiroshima, Japan on August 6, 1945. Ultimately, 1,152 calutrons were installed in nine large buildings at Y-12.

Little Boy along with Fat Man – a plutonium bomb, dropped on Nagasaki on August 9, 1945 - led to the end of World War II. Some say this action potentially saved more than a million lives that might have been lost during a land invasion of Japan, known as "Operation Downfall."

This uranium story is better known than the rest of the story of the Beta 3 Calutrons at Y-12. When the war ended, K-25 and its Gaseous Diffusion Process had just become fully operational. It was a far more efficient process for separating (enriching) uranium. The Y-12 calutrons (with their 14,700 tons of silver) were dismantled and removed from eight of the nine major buildings at Y-12. Only the two Alpha calutrons and two Beta calutrons in Building 9731, the Pilot Facility and the 72 Beta calutrons in Building 9204-3 (Beta 3) were not removed. The initial reason was to continue experiments to improve the proficiency of the calutron process. This proved to be impossible to do with any degree of success. But the people at Y-12 were not through.

Almost immediately the scientists at Y-12 realized that the calutrons were capable of being used to separate not just uranium, but most any element in the periodic table! This was a tremendous leap in knowledge and realized as potentially very significant. This scientific realization provided what was arguably to become an even more important contribution of the Beta 3 calutrons than the uranium-235 separated for the first atomic bomb. However, this particular aspect of the service to mankind made by the people and equipment first built for wartime use has not been recognized and has not been given its proper credit.

In the May 2005 issue of Physics Today, William E. Parkins’ article “The Uranium Bomb, the Calutron, and the Space Charge Problem,” concludes with the following summary: “The most important legacy of the project (the Y-12 calutrons) has been the contribution to science, technology, and medicine made possible through the use of separated isotopes of nearly all the elements of the periodic table. Hundreds of kilograms have been prepared for research and diagnostics in physics, chemistry, earth sciences, biology, and medicine. This service has been provided at cost for almost 60 years through the use of calutrons in the pilot units and Beta tracks at Y-12, all operated by Oak Ridge National Laboratory. Nationally and internationally, thousands of customers and millions of medical patients have benefited.”

Parkins’ reference for the above statement is an article by L. O. Love in Science magazine.

Parkins goes on to say, “The development and use of the calutron to produce enriched uranium for the first atomic bomb that was exploded in warfare, and then to produce the full spectrum of separated isotopes for uses in peacetime, is the greatest example of beating swords into plowshares in the history of human kind. For its contribution in both wartime and peacetime, the physics profession can be proud.”

Oak Ridge can be proud of the accomplishment of its citizens who contributed over the years to this most significant achievement that Parkins calls the “greatest example of beating swords into plowshares in the history of human kind.”

People like Joe Tracy and Scott Aaron who have managed this program and the numerous people who have done the exacting and precise work over the years should be given accolades and recognition for their roles in the significant contribution to medical research and treatment as well as other technological advances enhanced by stable isotope separation.

Alvin Weinberg, Director of the Oak Ridge National Laboratory for many years, when asked what was the most important contribution of Oak Ridge to the world, without hesitation said, "Medical Isotopes. They help millions of people every year." The exact same equipment, the same science, that helped produce the first atomic bomb ever used in warfare, also produced the stable isotopes that were sent to the Graphite Reactor to be made radioactive and used as nuclear medicine and other applications in industry and agriculture.

That really is an example of "beating swords into plowshares" in a real sense of the concept.