Position title: Nuclear Engineer III/IV (Reactor Design)
Location: Madison, WI
About Us:
Fissionaire is pioneering the next generation of nuclear technology to deliver safe, scalable, and sustainable energy. Our team is small, fast-moving, and mission-driven — combining deep technical expertise with a startup’s sense of urgency. As we grow, we’re designing the systems that will redefine what nuclear power can do for the world.
Job Summary:
We’re looking for a Nuclear Engineer III/IV to lead and contribute to the design, analysis, and optimization of our advanced nuclear reactor systems. The ideal candidate combines strong nuclear engineering fundamentals with hands-on design experience and the creativity to solve unprecedented challenges. This role requires innovative thinking, technical precision, and a proactive drive to advance clean energy technology from concept to reality.
Key Responsibilities:
- Lead reactor core and system-level design activities, including thermal-hydraulic, neutronic, and mechanical aspects.
- Perform analysis, simulation, and optimization using industry-standard nuclear design tools.
- Integrate fuel, coolant, and structural components into coherent system designs that meet safety, performance, and economic targets.
- Collaborate with mechanical, materials, and safety engineers to ensure design coherence and regulatory readiness.
- Conduct risk assessments and safety analyses to ensure designs meet stringent nuclear safety requirements.
- Prepare technical reports, design documentation, and presentations for internal stakeholders and regulatory bodies.
- Conduct trade studies and sensitivity analyses to guide design decisions.
- Participate in design reviews, safety analyses, and regulatory interactions
- Stay current with emerging reactor technologies, materials research, and simulation methodologies.
- Participate in project planning, budgeting, and scheduling to ensure timely delivery of design milestones.
- Contribute to a culture of innovation, accountability, and technical excellence.
‘
Qualifications
- Master’s degree in Nuclear Engineering, Mechanical Engineering or a related field. Ph.D. preferred but not required.
- Minimum of 3-5 years of experience in nuclear reactor design, analysis, or related fields within industry or in academic work.
- Proficiency with nuclear design and analysis software, such as MCNP, SCALE, RELAP5, COMSOL, MOOSE, ANSYS, SERPENT, OpenMC, or similar nuclear analysis codes.
- Strong understanding of neutronics, thermal-hydraulics, fuel cycle analysis, and reactor physics.
- Familiarity with CAD software for reactor component design.
- Proficiency in programming languages for data analysis, scripting, or automation of design processes.
- Knowledge of nuclear physics, neutronics, thermal-hydraulics, and reactor safety principles.
- Demonstrated ability to translate analytical results into design decisions.
- Experience with Molten Salt Reactor design.
- Demonstrated ability to work independently, take initiative, and drive projects to completion with minimal supervision.
- Excellent written and verbal communication skills for technical documentation and cross-functional collaboration.
- Familiarity with nuclear regulatory frameworks and safety standards.
- Knowledge of materials science, particularly related to radiation-resistant materials and high-temperature applications.
- Experience with risk assessments and analysis (PRA, FMEA etc.)
- Familiarity with computational fluid dynamics (CFD) for thermal-hydraulic analysis preferred.
- U.S. citizenship or permanent residency required.
What We Offer:
- Competitive salary
- Comprehensive benefits including medical, dental and vision
- Paid time off, sick leave and holidays
- Bereavement leave
If you are passionate about the energy that impacts our day-to-day lives and want to work with talented and dedicated people across the globe, apply today!
www.fissionaire.com
Fissionaire is an Equal Opportunity Employer that does not discriminate on the basis of actual or perceived race, colour, creed, religion, national origin, ancestry, citizenship status, age, sex or gender (including pregnancy, childbirth, pregnancy-related conditions, and lactation), gender identity or expression (including transgender status), sexual orientation, marital status, family or relationship structure, military service and veteran status, physical or mental disability, genetic information, gender identity, or any other characteristic protected by applicable federal, state, or local laws and ordinances. Fissionaire’s management team is dedicated to this policy with respect to recruitment, hiring, placement, promotion, transfer, training, compensation, benefits, employee activities, access to facilities and programs, and general treatment during employment.
Job Type: Full-time
Pay: $125,000.00 - $180,000.00 per year
Education:
Location:
- Madison, WI 53719 (Required)
Work Location: In person
