Senior Mechanical Engineer

Valar Atomics is a nuclear energy company focused on scaling high-temperature gas reactors (HTGRs) for grid-independent industrial applications. The company is developing what it calls gigasites, large-scale facilities housing hundreds of nuclear reactors intended to power heavy industry, data centers, hydrogen production, and clean hydrocarbon fuel synthesis. Their reactor design uses TRISO fuel, a graphite moderator, and helium coolant, a combination the company highlights for its strong safety profile and proliferation resistance. By operating outside the traditional electricity grid, Valar Atomics aims to unlock economies of scale that have historically eluded the nuclear industry. Valar Atomics' mission centers on making nuclear energy the cheapest and most reliable energy source in the world, with a particular emphasis on decarbonizing industrial processes and enabling clean fuel production. Their hydrogen output, generated via a sulfur-iodine thermochemical cycle, can be combined with captured CO2 to produce synthetic hydrocarbons through a modified Fischer-Tropsch process, offering a pathway to drop-in clean fuels. The company also targets the surging power demands of AI data centers, which are projected to require over 200 additional terawatt-hours of grid power by 2030. The company is currently advancing its Ward 250 project, a test reactor being developed in partnership with the U.S. Department of Energy, the San Rafael Energy Research Center, and the State of Utah, with a target go-live date of July 4, 2026, America's 250th birthday. The reactor has already been physically transported to Emery County, Utah, with logistical support from the U.S. military. Four executive orders issued under the Trump administration provided a mandate supporting the project's accelerated deployment timeline.

About Valar Atomics

At Valar Atomics, we're redefining what's possible in energy. Our mission is to make clean, high-temperature nuclear power scalable—unlocking abundant energy for industry, hydrogen, and next-generation manufacturing. We are a team of builders, engineers, and operators who believe nuclear energy should be fast to deploy, factory-made, and built for the real world. Our first pilot plant in Orangeville, Utah will demonstrate how advanced nuclear systems and fuel fabrication can power the future. Joining Valar Atomics means becoming part of a company where autonomy, ownership, and impact exist at every level.

The Role

We're seeking a highly skilled Senior Mechanical Design Engineer to join our engineering team and accelerate the frontier of advanced power generation. In this role, you'll be responsible for designing, developing, and validating mechanical systems and components that meet performance, manufacturability, and cost requirements. You'll work closely with cross-functional teams to bring innovative products from concept to production, and serve as a technical leader and mentor for less experienced engineers.

Key Responsibilities

• Lead mechanical design efforts for major subsystems, ensuring alignment between performance targets, manufacturability, and cost.
• Mentor junior engineers and review mechanical designs to ensure consistency with company standards and engineering rigor.
• Develop detailed 3D CAD models, assemblies, and engineering drawings (SolidWorks, Creo, or NX), applying advanced GD&T and tolerance analysis.
• Perform structural, thermal, and fluid analyses (FEA and CFD) to validate system performance and reliability.
• Oversee prototype fabrication, assembly, and testing, and interpret results to refine designs and improve system performance.
• Partner with electrical, manufacturing, and systems engineers to drive integration and design optimization.
• Work closely with vendors to manage DFM feedback, manufacturing process selection, and quality control.
• Contribute to internal best practices for mechanical design, documentation, and configuration management.

You Will Be Successful in This Role If

• You take true ownership of major subsystems, balancing performance, manufacturability, and cost in every design decision.
• You bring strong technical judgment to design trade-offs and know when to dig deeper versus when to keep moving.
• You apply analysis (FEA, CFD, hand calculations) appropriately, treating it as a tool for design decisions rather than a deliverable.
• You partner effectively with manufacturing and supplier teams, designing for what can actually be built and inspected.
• You mentor and develop other engineers, raising the technical capability of the team over time.
• You communicate and document clearly, leaving designs and design intent that other engineers can build on.
• You approach problems with a root-cause mindset, treating failures as opportunities to understand the system better.

Basic Qualifications

• Bachelor's degree in Mechanical Engineering or a related field.
• 5–10 years of experience in mechanical design and product development.
• Proven track record of designing and delivering production-ready hardware.
• Expertise in CAD (SolidWorks, Creo, NX, or similar) and mechanical drafting standards.
• Strong knowledge of materials, manufacturing processes, and mechanical systems.
• Experience performing or overseeing FEA and CFD analyses.
• Excellent communication, technical documentation, and leadership skills.

Preferred Skills and Experience

• Master's degree in Mechanical Engineering or a related field.
• Experience in high-performance or safety-critical systems (aerospace, energy, or defense).
• Deep understanding of DFM/DFA and reliability engineering.
• Familiarity with PLM/PDM tools and design control processes.
• Hands-on prototyping, testing, and validation experience.
• Strong analytical mindset with the ability to lead root cause investigations.

What We Offer  

• Competitive base salary 
• Equity ownership in a rapidly growing advanced energy company 
• Comprehensive medical benefits 
• Unlimited PTO
• Free daily lunch and dinner provided onsite 
• Generous PPE stipend
• High-impact startup environment with significant ownership and autonomy 
• Opportunities for rapid career growth and internal advancement 
• Direct collaboration with experienced operators, engineers, and industry leaders 
• The opportunity to help build and scale transformative energy technology from the ground up

Equal Employment Opportunity Statement

Valar Atomics is an equal opportunity employer. We consider all qualified applicants without regard to race, color, religion, sex, gender identity, sexual orientation, national origin, age, disability, veteran status, or any other protected status under applicable law.

We are committed to providing a workplace free of discrimination and harassment and will provide reasonable accommodation as required by law.

Applicants must be legally authorized to work in the United States as a U.S. citizen or lawful permanent resident (green card holder).