Mechanical Designer

Position: Mechanical Designer

Location:
Houston, TX or Remote Employment Type: Full Time Reports To: Director, Core Design

About Us
We are a next-generation nuclear technology startup pioneering the commercialization of High-Temperature Gas-cooled Reactors (HTGRs) — a proven, safe, and transformative technology for delivering ultra-high-temperature heat and enabling a carbon-neutral future. Our mission is to deploy the world’s first global fleet of Advanced Modular Reactors, redefining how clean energy powers industries, communities, and economies. As a fast-growing company in its early stage, every team member — whether in engineering, program management, partnerships, operations, or business development — plays a direct role in shaping our technology, culture, and impact. You’ll join a collaborative, mission-driven team of internationally recognized experts and innovators working together to bring advanced nuclear energy to the world. The Role The Mechanical Designer will be a key contributor to ZettaJoule’s reactor design activities, responsible for developing the 3D CAD models, assemblies, and detailed drawings that define the mechanical design of our High-Temperature Gas-cooled Reactor (HTGR). Working at the intersection of design engineering, analysis, materials, and manufacturing, this role translates engineering requirements and design concepts into buildable, maintainable, and inspectable components using 3D CAD tools. The Mechanical Designer maintains configuration-controlled CAD data, manages assembly-level interfaces across systems, and supports design reviews, fabrication vendors, and the technical baseline as the design matures from concept through detailed design.

Key Responsibilities
• Develop 3D models, assemblies, and 2D fabrication drawings for HTGR primary system components — reactor vessel, core internals, heat exchangers, hot gas ducting, and supporting structures.
• Apply GD&T and drafting standards to produce clear, complete, manufacturable drawing packages, including weld details, tolerancing, and inspection requirements.
• Design components with consideration for high-temperature service, including thermal expansion, differential growth, clearances, and support and restraint arrangements.
• Collaborate with Stress Analysis, Materials, Thermal Hydraulics, and Systems Engineering to incorporate analysis results, material constraints, and design loadings into the CAD design.
• Build and maintain large, multi-level assembly models and manage interfaces between systems and components, including interference checks, envelope and space allocation, and constructability and maintainability reviews.
• Prepare and maintain CAD models in a form suitable for simulation, such as simplified geometry, defeaturing, and mid-surface extraction, in support of finite element and CFD analyses.
• Create and manage bills of materials, part numbering, and revision control within a PDM/PLM environment (e.g., SolidWorks PDM) in coordination with Systems Engineering configuration management.
• Support design reviews, change control, and the design baseline by documenting design changes, and by generating visualizations and layout drawings for technical and stakeholder communication.
• Work with fabrication vendors and suppliers to resolve manufacturability questions, review shop drawings, and support fabrication, inspection, and assembly planning.
• Contribute to development of CAD standards, templates, and modeling best practices for the engineering team. What You'll Bring
• BS in Mechanical Engineering, Mechanical Engineering Technology, or a related field required; equivalent design experience considered.
• Minimum 5 years of experience as a mechanical designer or design engineer in an engineering or manufacturing environment.
• Advanced proficiency in SolidWorks, Autodesk Fusion, or other 3D CAD tools, including part, assembly, sheet metal, weldments, surfacing, and drawing modules; CSWP or CSWE certification strongly valued.
• Working knowledge of GD&T and of engineering drawing and documentation standards.
• Experience designing pressure-retaining equipment, heat exchangers, piping, or other heavy industrial components for energy, process, or aerospace applications.
• Experience working within a PDM/PLM system and configuration-controlled design environment. Citizenship U.
S. citizenship or U.
S. permanent resident status is required. Access to EAR-controlled and 10 CFR 810-governed nuclear technology requires authorization consistent with U.
S. export control law. Even Better
• Experience designing nuclear, high-temperature, or high-pressure components, or working under ASME Section III / Section VIII requirements or a nuclear quality assurance program (10 CFR 50 Appendix B / NQA-1).
• Experience with SolidWorks PDM, SolidWorks Simulation, or Flow Simulation, or with design-for-analysis workflows.
• Experience with design for welding, high-temperature alloys, or graphite and ceramic components.
• Familiarity with other CAD platforms (e.g., Creo, Inventor, NX, or CATIA) or plant layout tools.
• Experience in an early-stage or startup engineering environment with rapidly evolving designs.
• Experience with AI driven 3D CAD design. Why Work for Us
• Competitive salary.
• Flexible hours & remote options.
• Health/Life/Disability benefits.
• Vacation/Sick leave.
• Work alongside internationally recognized experts shaping the future of nuclear energy. EEO Statement ZettaJoule is an Equal Employment Opportunity employer committed to diversity and inclusion.