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Leadership Team

Brief profiles of Oak Ridge National Laboratory's Leadership Team members are linked to each member's name. For more information about ORNL management, please contact us at


Thomas Zacharia
Laboratory Director

Thomas Zacharia, director of Oak Ridge National Laboratory (ORNL) since July 1, 2017, guides the application of an exceptionally broad set of core capabilities to the solution of compelling problems in science and technology, exploiting ORNL's signature strengths in materials science and engineering, high-performance computing and computational sciences, neutron science, and nuclear science and technology to deliver mission outcomes for the U.S. Department of Energy (DOE) and other sponsors.


Lindsey Twardy
Chief of Staff

Lindsey Twardy serves as an advisor to the Laboratory Director and helps to integrate leadership across ORNL to advance the Lab’s vision, fulfill mission objectives, and ensure operational effectiveness.





Moe Khaleel
Deputy for Science and Technology (Interim)
and Projects

Moe Khaleel oversees one of the nation's most extensive portfolios of research and development, spanning physical and materials sciences, energy and engineering sciences, computing and computational sciences, biological and environmental sciences, neutron sciences, and global security, as well as projects that will ensure US leadership across diverse disciplines, for the U.S. Department of Energy and other sponsors.



Alan Icenhour
Deputy for Laboratory Operations

Alan Icenhour coordinates overall operations and support functions at the Oak Ridge National Laboratory: facilities operations; environment, safety, and health; business operations; security; human resources; communications; and technology transfer. In concert with the Deputy Director of Science and Technology, he supports the Laboratory Director in the planning, integration, and execution of Laboratory-level initiatives.



Ken Andersen
Associate Laboratory Director, Neutron Sciences

Ken Andersen brings extensive experience to the neutron scattering research and user programs at ORNL. He joined ORNL from the European Spallation Source in Sweden, where he led the Neutron Instruments Division and oversaw the selection and construction of instruments from conceptual development through design, procurement, installation and commissioning. 



J. Scott Branham
Director, Business Services

As Chief Financial Officer, Mr. Branham leads the Laboratory's Business Services Directorate, with responsibility for directing the ORNL budgeting process and business management functions and delivering relevant and reliable financial analysis and reporting. The directorate's functions include procurement, accounting, business analysis, business systems, pension and savings operations, small business contracting, and prime contract administration. Mr. Branham also serves as Chief Financial Officer for UT-Battelle, LLC.


Deborah Frincke
Associate Laboratory Director,
National Security Sciences

Deborah Frincke guides research and development of science-based solutions to complex threats to public safety, national defense, energy infrastructure, and the economy. Leveraging the Lab's broad science foundation, she oversees multi-disciplinary teams who apply capabilities in nuclear and uranium science, high-performance computing, geographical information science, cyber and data science, applied materials, and advanced manufacturing to national security challenges.


John Haines
Director, Second Target Station Project 

John Haines is director of the Second Target Station Project Office. He brings more than 30 years of experience leading project teams for technologically challenging systems and projects to his post at the laboratory. Before assuming his current position, John held leadership posts at the European Spallation Source, most recently managing the ESS construction project.



Cynthia Jenks
Associate Laboratory Director,
Physical Sciences

Cynthia Jenks stewards ORNL's broad physical sciences portfolio, with particular emphases on quantum materials; structural materials and alloys; soft materials; nanoscience; and applications of materials and chemistry in energy and security.




David Keim
Director, Communications

David Keim leads the Communications Division at Oak Ridge National Laboratory. His responsibilities include media and community relations, internal communications, protocol visits and lab events, and he led the multi-site design team for the new American Museum of Science and Energy. His staff provides strategic support for Lab leadership and ensures the quality of science writing, technical editing, design, photography, and videography across ORNL’s diverse research portfolio.



Douglas B. Kothe
Director, Exascale Computing Project 

Douglas B. Kothe has more than three decades' experience conducting and leading applied R&D in computational applications to simulate complex physical phenomena in energy, defense, and manufacturing. Previously ORNL's Deputy Associate Laboratory Director for Computing and Computational Sciences, Dr. Kothe also served as Director of the Consortium for Advanced Simulation of Light Water Reactors, DOE’s first Energy Innovation Hub (2010-2015), and as Director of Science at the National Center for Computational Sciences (2006-2010).


C. Gail Lewis
Chief Audit Executive and 
Director, Internal Audit

Ms. Lewis has served as the UT-Battelle Chief Audit Executive since September 2011. She leads the Internal Audit Directorate, which is responsible for all audit activities, and the staff concerns program. The organization provides independent, objective assurance and consulting services designed to support and improve the effectiveness of risk management, control, and governance processes through evaluations of all ORNL management systems, processes, and programs.


David J. Mandl
General Counsel

David Mandl is the lab's General Counsel and Secretary of UT-Battelle, LLC. He has 20 years of legal experience, primarily in environmental, safety and health law; nuclear safety and radiological protection; security (including physical and information/cyber); corporate law and governance; and fraud and the civil False Claims Act. He has served as primary legal counsel to various Lab organizations, committees and projects, and he advises senior management regarding regulatory compliance, risk management, and public relations.


Kathryn McCarthy
Associate Laboratory Director,
Fusion and Fission Energy and Science

Kathy McCarthy joined ORNL after serving as vice president for science and technology and director of the Canadian Nuclear Laboratories. She also held leadership roles at Idaho National Laboratory as director of domestic programs in INL’s Nuclear Science and Technology Directorate, director of the Light Water Reactor Sustainability Program Technical Integration Office, and national technical director for the Systems Analysis Campaign for DOE Nuclear Energy’s Fuel Cycle R&D Program.


Jeffrey Allen Nichols
Associate Laboratory Director, 
Computing and Computational Sciences

Dr. Nichols has led ORNL’s Computing and Computational Sciences Directorate since April 2009, overseeing the National Center for Computational Sciences (NCCS), home to the National Leadership Computing Facility, which delivers state-of-the-art scientific research and technological innovations. He leads the lab’s agenda in advanced high-performance computing in priority areas such as climate change, fusion energy, nanotechnology, and biotechnology.



John Powell
Environment, Safety, Health, and Quality

John Powell is an environmental engineer with more than 35 years of ES&H experience within the U.S. Department of Energy (DOE) complex.





Jimmy Stone
Director, Facilities and Operations

Jimmy Stone manages seven divisions that provide critical laboratory support services. These include facility operations, laboratory protection (security, fire protection, emergency preparedness, and emergency management), engineering and construction management, materials fabrication, site services, logistical functions, and craft services. In addition, the Facilities and Operations Directorate includes facilities strategic planning and natural resources functions.



Xin Sun
Associate Laboratory Director, 
Energy Science and Technology

As ORNL’s Associate Laboratory Director (ALD) for the Energy Science and Technology Directorate, Dr. Xin Sun leads a $305 million research portfolio focused on translating science into solutions for the most critical problems facing society at the nexus of energy and security.



Balendra Sutharshan
Associate Laboratory Director,
Isotope Science and Engineering

Associate Laboratory Director Dr. Balendra Sutharshan, who joined ORNL in 2021, leads the Isotope Science and Engineering Directorate (ISED), which is comprised of two research divisions (Radioisotope Science and Technology, and Enrichment Science and Engineering) and one operating division (Nonreactor Nuclear Facilities).



Stan Wullschleger
Associate Laboratory Director,
Biological and Environmental Systems Science

As ORNL’s Associate Laboratory Director (ALD) for Biological and Environmental Systems Science, Dr. Stan Wullschleger leads a $107 million research portfolio targeting the convergence of biology, ecology, engineering, data discovery, physical sciences, and computing to advance U.S. competitiveness in the global bioeconomy and Earth system sustainability.


Jody Zahn
Director, Human Resources

Jody Zahn is the Human Resources Director at Oak Ridge National Laboratory and oversees the talent acquisition, talent services, labor relations, benefits, diversity, immigration, employee and organizational development, and compensation functions at the laboratory.