Position Title: Structures Engineer
Location: Madison, WI

About Us We’re 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 systems that will redefine what nuclear power can do for the world.

About the role Fissionaire is building the next generation of nuclear technologies, and this role is responsible for turning ideas into parts. You’ll own the design and structural analysis of reactor and support system parts, support multidisciplinary engineering teams, and ensure designs meet up with nuclear-grade expectations. If you thrive in high-accountability environments and want your work to directly shape future nuclear systems, this is where you’ll make an impact.

Key Responsibilities

● Develop detailed CAD models for nuclear system components, mechanical assemblies, piping, shielding, and structural elements.

● Develop structural loads in coordination with other engineering teams

● Analyze and size components, assemblies and systems based on developed loads using industry standards, engineering calculations and FEM.

● Develop and implement analysis methods that to include static, cyclic and thermal loads.

● Support design, development and execution of structural and hydraulic tests.

● Create analysis reports to support reactor licensing per business standards.

● Coordinate across disciplines to ensure all loads and design constraints are fully understood and captured.

● Maintain configuration control, analysis standards, revision logs, and documentation in accordance with nuclear QA frameworks (e.g., ASME NQA-1, ANSI/ANS standards).

● Support design reviews by preparing designs, analysis, interface checks, and tolerance analyses.

● Collaborate closely with other mechanical, nuclear, thermal-hydraulic, and systems engineers to refine concepts, resolve design issues, and ensure alignment across disciplines.

● Assist in vendor interface by providing clear specifications, answering technical queries, and updating designs/analysis as needed.

● Contribute to continuous improvement of design and analysis workflows, libraries, and standards.

● Willing to relocate to Madison, WI

Qualifications

● Bachelor’s or Masters degree in Mechanical, Nuclear, Aerospace or related field and 10+ years experience in structures design and analysis roles.

● Proficiency with modern CAD tools (e.g., SolidWorks, Inventor, Creo, AutoCAD, or similar).

● Experience with high temperature structural design and analysis.

● Expertise in common structural analysis software (ANSYS, NASTRAN, FEMAP etc)

● Experience applying nuclear-industry standards (ASME, ASTM, RCC-MRx, etc.).

● Ability to read, interpret, and develop engineering drawings.

● Detail-driven mindset with a disciplined approach to documentation and version control.

● US Citizenship, or Permanent Resident status required.

Preferred Qualifications

● Experience in reactor design, radiation shielding, balance-of-plant systems, or nuclear fuel cycle equipment.

● Familiarity with PLM/PDM systems (Windchill, Teamcenter, etc.).

● Background in piping design, pressure vessel design, or seismic qualification and fatigue spectrum development.

● Exposure to manufacturing processes, suppliers, and tolerancing best practices in regulated environments.

What Success Looks Like

● Development and analysis of reactor structures designs that meet business timelines , objectives and quality standards.

● Use of creative problem solving to find ways to accelerate development while maintaining quality standards and design objectives.

● You communicate clearly and communicate effectively, to maintain coordination across the IPT.

● You take ownership of your work and help push Fissionaire’s designs forward with confidence and precision.

Fissionaire’s technology is subject to U.S. export control regulations, which require the company to review applicants’ eligibility based on their citizenship or residency status. As part of the application process, candidates will be asked to indicate whether they are a U.S. citizen, or permanent resident to support this review. Because government authorization timelines can vary, Fissionaire is unable to consider alternate resident statuses where required approvals may not be obtainable within a timeframe that meets business needs.

What We Offer

• Competitive salary with equity options
• Comprehensive benefits, holiday and PTO schedule
• Opportunity to work with a groundbreaking nuclear startup

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.

Benefits:

• Dental insurance
• Health insurance
• Life insurance
• Paid time off
• Vision insurance

Education:

• Bachelor's (Required)

Work Location: In person