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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


Jeff Smith
Interim Laboratory Director

Jeff Smith, interim director of Oak Ridge National Laboratory, 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.

Susan Hubbard
Deputy for Science and Technology

Susan Hubbard guides one of the nation’s most extensive portfolios of research and development, spanning computing and computational sciences, materials science, environmental and biological research, energy science and technology, isotope research and development, fission and fusion energy, neutron sciences, and national security sciences. In concert with the Deputy for Laboratory Operations, she supports the Laboratory Director in the planning, integration, and execution of Laboratory-level initiatives.

Alan Icenhour
Deputy for 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.

Lindsey Twardy
Chief of Staff

Lindsey Twardy is Chief of Staff at Oak Ridge National Laboratory. In this role, she 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.

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.

Jeremy Busby
Associate Laboratory Director, Fusion and Fission Energy and Science

Jeremy Busby is the Associate Laboratory Director for Fusion and Fission Energy and Science at Oak Ridge National Laboratory. He oversees the directorate’s unique facilities, capabilities, and talented scientists and engineers who are tackling such challenges as extending operations of the current US nuclear reactor fleet; investigating economical and flexible advanced reactor systems; and making fusion energy a viable power source.

Bart O. Iddins
Director, Environment, Safety, Health, and Quality

Dr. Bart Iddins serves as director of Environment, Safety, Health and Quality. He joined the Laboratory in June 2018 as director of the Health Services Division after retiring from the Air Force as a major general. He concluded his military career as commander of the 59th Medical Wing at Joint Base San Antonio, Texas, and CEO of the San Antonio Military Health System, with 8,000 direct personnel and a $1.2 billion budget.

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.

Moe Khaleel
Associate Laboratory Director, National Security Sciences

Dr. Moe Khaleel guides the research and development of science-based solutions to counter critical threats to public safety, national defense, energy infrastructure and the economy. Leveraging the broad science foundation at ORNL, he oversees the work of multi-disciplinary research teams with signature capabilities in nuclear and uranium science, high-performance computing, geographic information science, cyber security science and advanced manufacturing.

Douglas B. Kothe
Associate Laboratory Director, 
Computing and Computational Sciences

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, 

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
Director, US ITER Project

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.

Graeme Murdoch
Director, Second Target Station Project 

Graeme Murdoch is the project director for the Second Target Station. He has over 35 years of progressive experience working in technical and management capacities in a particle accelerator and fusion engineering environment. 

Tyler Owens
Federal Affairs Director

Tyler Owens is federal affairs director at ORNL. In this role, he serves as ORNL’s senior representative and chief liaison to government officials, industry, think tanks, and university representatives in Washington, D.C. He provides guidance to the laboratory director to develop and execute strategies that best position ORNL in the evolving federal policy environment. He is also responsible for presenting ORNL’s priorities to Congress, the administration, and federal agencies.

Fred Pieper
Chief Audit Executive and 
Director, Internal Audit

Fred Pieper, who has served as a chief audit executive for 14 years, leads the Internal Audit Directorate, which is responsible for all audit activities and the Employee Concerns Program at ORNL. The organization provides independent, objective assurance and consulting services to improve the effectiveness of risk management, internal control, and governance processes through evaluations of ORNL management systems, processes, and programs.

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 composed 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

Human Resources Director Jody Zahn oversees ORNL’s efforts to recruit and retain premier talent who bring together diverse ideas, cultures, and educational backgrounds to achieve the Laboratory’s mission. In addition to talent strategy and talent development, Zahn’s responsibilities span HR operations, labor relations, talent engagement and mobility, and total rewards.