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ORNL Directors

Stephen Streiffer portrait

Stephen Streiffer, Laboratory Director

2023–present
UT-Battelle

As a materials scientist, Streiffer joined ORNL after extensive experience across the national laboratory system. He previously served as the interim director of SLAC National Accelerator Laboratory and spent 24 years at Argonne National Laboratory, concluding his tenure as the deputy director for science and technology.

Thomas Zacharia

Thomas Zacharia, Laboratory Director

2017–2022
UT-Battelle

In 2017, Zacharia was appointed laboratory director. Zacharia began his career at ORNL as a postdoctoral fellow in 1987. Understanding the incredible potential of computing to improve scientific research, Zacharia advanced computational science at the laboratory as the leader of a new materials modeling and simulation group. Through several leadership roles, including associate laboratory director for computing and deputy director for science and technology, Zacharia built the laboratory into a global supercomputing power.

Thom Mason

Thom Mason, Laboratory Director

2007–2017
UT-Battelle

A condensed matter physicist, Mason joined ORNL in 1998 to serve as science director for the Spallation Neutron Source project, which was under construction. As laboratory director, Mason signified a shift from modernization and growth to "executing the science."

Jeff Wadsworth

Jeff Wadsworth, Laboratory Director

2003–2007
UT-Battelle

During Jeff Wadsworth's tenure, ORNL established the Oak Ridge Leadership Computing Facility, completed construction of the Spallation Neutron Source, moved the U.S. ITER office to Oak Ridge, and made great strides in laboratory safety and operations. An internationally recognized metallurgist, Wadsworth left ORNL in 2007 to become executive vice president for laboratory operations at Battelle.

ORNL Image

Bill Madia, Laboratory Director

2000–2003
UT-Battelle

A former Battelle nuclear researcher, Madia was part of DOE's "Blue Ribbon Panel" to consult on the Three Mile Island accident. Prior to joining ORNL, Madia served as director at another Battelle-managed laboratory, Pacific Northwest National Laboratory. Construction began on the Spallation Neutron Source and the Center for Nanophase Materials Sciences during his tenure as director.

Alvin Trivelpiece

Alvin Trivelpiece, Laboratory Director

1989–2000
Martin Marietta Energy Systems
Lockheed Martin Energy Research

As director, Trivelpiece led ORNL into new partnerships with universities and industrial firms in efforts to achieve faster technology transfers to the commercial marketplace. Trivelpiece promoted high-performance scientific computing at the laboratory and started the process that eventually led to the construction of the Spallation Neutron Source.

 Alex Zucker

Alex Zucker, Laboratory Director

1988–1989
Martin Marietta Energy Systems

When Herman Postma assumed the role of senior vice president at Martin Marietta Energy Systems, Zucker was named acting director. Zucker first came to the laboratory in 1950 and was an early pioneer in nuclear physics research. He was later instrumental in several administrative milestones, such as helping bring about the High Temperature Materials Laboratory.

Herman Postma

Herman Postma, Laboratory Director

1974–1988
Union Carbide Corporation
Martin Marietta Energy Systems

With a background in nuclear fusion, rather than fission, Postma was the first ORNL director without Manhattan Project experience. Coinciding with the oil crisis of the 1970s, Postma's tenure as director saw new directions for the laboratory, including expansion of environmental science and conservation projects.

Floyd Culler

Floyd Culler, Laboratory Director

1973–1974
Union Carbide Corporation

Deputy laboratory director during Weinberg’s departure, Culler assumed the role of acting laboratory director in 1973. Coming from the Y-12 plant, Culler began his career at ORNL in 1947 as a design engineer for nuclear-fuel recycling plants and later served as director of the Chemical Technology Division and associate laboratory director for nuclear technology.

Alvin Weinberg

 

Alvin Weinberg, Laboratory Director

1955–1973
Union Carbide Corporation

Weinberg came to ORNL in 1945 to join the Physics Division at the urging of mentor Eugene Wigner, became division chief in 1947, then succeeded Wigner as ORNL research director in 1948. Weinberg is credited with communicating the meaning and intent of "Big Science," a phrase that has become commonplace among both scientists and policymakers. Weinberg led ORNL through years of maturing and diversification, and served as a scientific advisor to Presidents Dwight D. Eisenhower and John F. Kennedy. A proponent of nuclear energy, he wrote often of issues concerning nuclear energy and the broader relationship between society and technology.

Clarence Larson

Clarence Larson, Laboratory Director

1950–1955
Union Carbide Corporation

A veteran of the Manhattan Project, Larson led the design and construction of the calutrons used for electromagnetic separation of uranium-235 during the war. Following acting executive director Nelson Rucker, Larson presided over the $20 million budget for new buildings.

Nelson Rucker

Nelson Rucker, Executive Director

1948–1950
Union Carbide Corporation

During the search for a permanent laboratory director, Union Carbide Corporation named Nelson Rucker, then plant manager at Y-12, executive director of ORNL. Rucker had been a graduate of Virginia Military Institute and a former Carbide plant manager in West Virginia before coming to Oak Ridge with Carbide during the war.

Prescott Sandidge

Prescott Sandidge, Executive Director

1947–1948
Monsanto Chemical Company

Following James Lum's departure in 1947, Lum's assistant Sandidge was named executive director while Monsanto Chemical Company completed its contract for the Atomic Energy Commission.

Eugene Wigner

Eugene Wigner, Director for Research and Development

1946–1947
Monsanto Chemical Company

Wigner came to the laboratory in early 1946 on a year’s leave from Princeton University. His goals as research director were developing university research reactors; establishing nuclear science training; and coordinating scientific research with universities throughout the South.

James Lum

James Lum, Executive Director

1945–1947
Monsanto Chemical Company

As executive director, Lum oversaw administrative tasks for the laboratory, while the director for research and development oversaw the science mission.

Martin Whitaker

Martin Whitaker, Laboratory Director

1943–1945
U.S. Army

Instrumental in building the Chicago Pile 1 at Stagg Field in Chicago, Whitaker brought Enrico Fermi and Arthur Compton to Oak Ridge to witness the first operation of the Graphite Reactor.