Lyle Benjamin Borst

Abstract

Lyle Benjamin Borst, who led the construction of the graphite reactor at Brookhaven National Laboratory, died on 30 July 2002 at his home in Williamsville, New York.Lyle was born on 24 November 1912 in Chicago, Illinois. He received both bachelor’s and master’s degrees in chemistry from the University of Illinois. In 1941, he was awarded a PhD in chemistry from the University of Chicago. His doctoral dissertation, prepared under William Draper Harkins, was entitled “The Angular Distribution of Recoil Nuclei.”Between 1941 and 1943, Lyle was a research associate at the Metallurgical Laboratory in Chicago. He joined Clinton Laboratories (later Oak Ridge National Laboratory) in Oak Ridge, Tennessee, in 1943; there he worked as a senior physicist on the Manhattan Project. In 1946, he was named chairman of Brookhaven’s department of reactor science and engineering, where he developed the design of the lab’s graphite reactor and eventually was in charge of its operation.Lyle had been involved earlier in the X-10 reactor at Oak Ridge, which was also air cooled. That experience led him to a number of changes that greatly enhanced the design of the new reactor in terms of its research capability. Most important, he changed the geometry of cooling by designing a vertical cut across the center of the graphite structure, thus separating the two halves and permitting the coolant air to enter the approximately 10-centimeter-wide gap. The coolant then moved in opposite directions through the two halves into separate plenums and then to a common stack for release at about 350 feet above ground. The separation of the coolant stream into the two halves led to cooling channels only half as long as the graphite structure. The shortened air-flow path reduced the pressure drop of coolant across the reactor markedly for a given rate of flow through each channel and led to substantially increased power for the same pressure drop.As a result of Lyle’s innovations, the design power of the graphite reactor was 28 MW compared to the 2–3 MW of the X-10 reactor. Lyle also settled on control and scram rods that penetrated the core at the corners in a diagonal scheme, which allowed for the reactor’s maximum surface area to be used for experimental facilities. More than 50 experiments could be installed simultaneously—more than all other research reactors in the world combined.Lyle’s design also improved the cooling of the reactor’s fuel. To permit the relatively high power that the reactor generated, the natural uranium fuel was enclosed in aluminum tubes with six fins each to increase the heat transfer area. The sealed cans with the fuel elements were filled with an atmosphere of helium to protect the uranium from oxidation by the coolant air. The system’s integrity was monitored for leaky elements by sensors. In 1951, Lyle left Brookhaven for the University of Utah, where he became a professor of physics. At that time, atmospheric testing of nuclear weapons was at a peak, which greatly upset Lyle. After collecting fallout in his yard and concluding that the resulting amounts of radioactive material were health-threatening, he gave interviews to newspaper reporters about his concerns and made his views known to the Atomic Energy Commission.Lyle left Utah in 1954 for a faculty position at New York University, where he taught physics and nuclear engineering. While at NYU, we sent him a supply of uranium slugs from the graphite reactor’s stockpile that we had used in a maximum-criticality experiment. Lyle used the uranium in an experimental lattice arrangement installed in an olive barrel, an experiment that became known as the “Pickle Barrel” experiment. The “pickle barrel” ended up in the Smithsonian Institution as the first teaching subcritical reactor.In 1961, Lyle joined SUNY Buffalo as a professor of physics. He served in that position until 1983, when he was named a professor emeritus.Lyle was a proponent of openness in the nuclear program. He cofounded both the Association of Oak Ridge Scientists and the Federation of American Scientists, organizations that had openly backed the McMahon bill and civilian rather than military control of atomic energy. Later, he was a member of the national board of the American Civil Liberties Union.Lyle was a strong and forceful advocate for what he believed was technically and morally correct. His efforts have left a lasting imprint on the peaceful uses of atomic energy. Lyle Benjamin Borst PPT|High resolution© 2003 American Institute of Physics.