Group Leader - Reactor Analysis and Modeling

Date: Oct 31, 2023

Location: Oak Ridge, TN, US, 37830

Company: Oak Ridge National Laboratory

Requisition Id 11968 


We are seeking a Group Leader for our Reactor Analysis and Modeling Group who will focus on coordinating the performance of quantitative analyses needed to support operation and planned upgrades of the High Flux Isotope Reactor (HFIR). This position resides in the Reactor Analysis and Modeling Group in the Nuclear Safety and Experiment Analysis Section (NSEA), Research Reactors Division (RRD), Neutron Sciences Directorate at Oak Ridge National Laboratory (ORNL).  


As part of our team, you will work in an analytical environment using specialized modeling programs and tools, supporting cross-disciplinary teams, and collaborating with people having diverse cultural backgrounds both inside and outside the organization! The successful candidate should have a strong background in nuclear reactor analysis, a curiosity about various nuclear engineering subject areas, and the capability to lead a technically diverse program in support of HFIR.


Major Duties/Responsibilities: 

  • Provide programmatic leadership to the team of technically diverse reactor analysts who support HFIR nuclear safety, experiment analysis, and research activities through modeling, analysis, and engineering evaluations.
  • Lead by example by performing high-quality reactor modeling, simulation, and analysis activities to support the nation’s most versatile research reactor.
  • Mentor staff and manage the scope of the reactor analysis and modeling program.
  • Provide relevant input to assist the NSEA Manager and other group or program leads to support safe, reliable, and efficient operations as well as the RRD’s achievements and scientific missions.
  • Work with the Experiments and R&D Programs Group to support programmatic missions, such as isotope production and materials irradiation.
  • Collaborate on projects, such as the high-enriched uranium to low-enriched uranium fuel conversion project.
  • Support the use of computer clusters and simulation codes, including software quality assurance activities to meet applicable regulations.
  • Perform safety analyst role for assigned systems, such as fuel and control elements, including evaluations through the Unreviewed Safety Question (USQ) process.
  • Collaborate with staff throughout RRD and other ORNL directorates and divisions to support RRD and ORNL missions.
  • Thoroughly document and present work performed to meet project deliverables.
  • Prepare and review publications to document reactor analysis and modeling for HFIR and associated research programs.
  • Ensure technical compliance with 10CFR830 Subparts A and B, affecting reactor safety, through implementation of ORNL Standards Based Management System (SBMS) and RRD procedures.
  • Ensure adherence to the rules and regulations that govern the operation of a DOE nuclear facility and ensure compliance with Environment, Safety and Health (ES&H) and QA requirements.
  • Maintain a strong commitment to nuclear safety and human performance improvement initiatives.
  • Deliver ORNL’s mission by aligning behaviors, priorities, and interactions with our core values of Impact, Integrity, Teamwork, Safety, and Service. Promote diversity, equity, inclusion, and accessibility by encouraging a respectful workplace – in how we treat one another, work together, and measure success.


Basic Qualifications:

  • A PhD in a science or engineering field with at least 2 years of relevant experience. (A bachelor’s degree in a relevant field will be considered with at least 8 years of experience or a master’s degree in a relevant field with 6 years of related experience will also be considered.)
  • Strong reactor analysis background in a related field, such as reactor physics or thermal hydraulics, as proven through graduate thesis research, publications, and/or work experience.
  • Must be organized, diligent, and sensitized to a nuclear safety culture.


Preferred Qualifications:

  • A PhD with 4 or more years of relevant experience.
  • Experience modeling and analyzing research reactors with software, such as MCNP, SCALE, COMSOL, and RELAP.
  • Experience and knowledge of the multi-physics reactor engineering framework, including the interplay between reactor physics, thermal-hydraulics, thermal-structural interaction, fluid dynamics, transient analysis, and accident analysis.
  • Experience with LINUX or LINUX-like environments and scripting/computer languages, such as MATLAB, Python, and Fortran
  • Familiarity and experience with 10CFR830 Subparts A and B and the USQ process.
  • Experience at a commercial, research, or naval reactor.
  • NRC/DOE regulatory experience and/or past interaction with regulators.
  • Experience with DOE-STD-3009 and/or Regulatory Guide 1.70.
  • Demonstrated problem-solving skills and a willingness to apply those skills to a variety of engineering problems.
  • Excellent communication skills, including verbal, presentation, and writing skills.
  • Motivated self-starter with the ability to work independently and to participate creatively in collaborative teams across the laboratory.
  • Ability to function well in a fast-paced research environment, set priorities to accomplish multiple tasks on time and adapt to evolving needs.


Special Requirements:

L clearance: This position requires the ability to obtain and maintain a clearance from the Department of Energy. As such, this position is a Workplace Substance Abuse (WSAP) testing designated position. WSAP positions require passing a pre-placement drug test and participation in an ongoing random drug testing program.


Benefits at ORNL:  

ORNL offers competitive pay and benefits programs to attract and retain hardworking people. The laboratory offers many employee benefits, including medical and retirement plans and flexible work hours, to help you and your family live happy and healthy. Employee amenities such as on-site fitness, banking, and cafeteria facilities are also provided for convenience.


Other benefits include the following: Prescription Drug Plan, Dental Plan, Vision Plan, 401(k) Retirement Plan, Contributory Pension Plan, Life Insurance, Disability Benefits, Generous Vacation and Holidays, Parental Leave, Legal Insurance with Identity Theft Protection, Employee Assistance Plan, Flexible Spending Accounts, Health Savings Accounts, Wellness Programs, Educational Assistance, Relocation Assistance, and Employee Discounts.


If you have difficulty using the online application system or need an accommodation to apply due to a disability, please email: or call 1.866.963.9545.




This position will remain open for a minimum of 5 days after which it will close when a qualified candidate is identified and/or hired.

We accept Word (.doc, .docx), Adobe (unsecured .pdf), Rich Text Format (.rtf), and HTML (.htm, .html) up to 5MB in size. Resumes from third party vendors will not be accepted; these resumes will be deleted and the candidates submitted will not be considered for employment.

If you have trouble applying for a position, please email

ORNL is an equal opportunity employer. All qualified applicants, including individuals with disabilities and protected veterans, are encouraged to apply.  UT-Battelle is an E-Verify employer.

Nearest Major Market: Knoxville