Mechanical Engineer

Hukari Ascendent is a Women-Owned, Small Business specializing in comprehensive engineering and technical support services associated with commercial nuclear power and other Department of Energy (DOE) nuclear activities.

Operating at 85 MW, the High Flux Isotope Reactor (HFIR) is the highest flux reactor‑based source of neutrons for research in the United States and provides one of the highest steady‑state neutron fluxes of any research reactor in the world. The Research Reactors Division (RRD) is responsible for operating and maintaining HFIR, while the HFIR Upgrades Project Office manages both the HFIR Beryllium Reflector Replacement (HBRR) and Pressure Vessel Replacement (PVR) Projects.

This position seeks an experienced engineering professional with over 10 years of hands‑on experience at an operating nuclear reactor, including expertise in engineering design and manufacturing practices. The ideal candidate will have a strong background in welding and joining techniques, combined with a solid understanding of machine design principles and comprehensive knowledge of ASME Boiler and Pressure Vessel Codes (Sections III and VIII) and ASME B31.1 piping codes.

This role will support efforts to restore HFIR’s operating power from 85 MW back to 100 MW as part of the PVR Project, which is currently in the early stages of Critical Decision-1 (CD-1), as defined by DOE Order 413.3B. The individual will work closely with system engineers, designers, and various other disciplines within RRD to deliver design milestones on schedule and within scope.

• Apply engineering expertise to support HFIR operations
• Prepare engineering designs for new installations and for replacement or upgrade of HFIR structures, systems, and components (SSCs)
• Perform calculations and analyses to support design basis and requirements
• Apply relevant codes and standards, including ASTM, ASME Boiler and Pressure Vessel Code, ASME B31 piping codes, NQA-1, AWS, etc.
• Support development of reactor core component replacement plans
• Prepare design specifications and define acceptance criteria for component upgrades
• Update material specifications and provide technical support for material procurement
• Implement modifications in accordance with RRD configuration control processes

• Bachelors degree in mechanical engineering, nuclear engineering, or related discipline
• Minimum of 10 years in DOE nuclear facilities and/or commercial nuclear plants
• Comprehensive understanding of nuclear technology, including reactor safety basis, design, and construction
• Proficiency in engineering design and manufacturing practices, including welding and joining techniques and machine design
• Familiarity with DOE Orders and Standards (e.g., DOE O 420.1C, DOE STD 1189, DOE STD-)
• Strong ability to read and interpret mechanical design drawings and apply GD&T principles (ASME Y14.5)
• Experience with AutoPIPE and finite element analysis is desirable
• Experience with configuration management and engineering change control processes in a nuclear environment
• Must be qualified for access to technology subject to export control requirements without an export control license
• This position may require Workplace Substance Abuse Program (WSAP) testing, including passing a pre‑placement drug test and participation in an ongoing random drug testing program

Hukari Ascendent offers an excellent benefits package including medical, dental, vision, and life insurance, 401(k) plan, and paid time off.

Opportunities with Hukari Ascendent change frequently. For a complete listing of our current openings, please visit our website at

Hukari Ascendent is an Equal Opportunity/Affirmative Action Employer. All qualified applicants receive consideration for employment without regard to age, disability, race, color, religion, creed, national origin, sex, marital status, sexual orientation, veteran or military status including disabled veterans and Vietnam era veterans, or other protected status.

Hukari Ascendent maintains a drug‑free workplace.