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Salary: USD 110,000 - 180,000 / annual
General Matter is a venture-backed nuclear fuel enrichment company incubated within Founders Fund, backed by over a dozen top-tier VC firms. The company is building the world's lowest-cost uranium enrichment services in the US to support advanced reactors, AI, and critical manufacturing. The mission is to make nuclear energy the cleanest, safest, and most affordable baseload power source.
As a Mechanical Test Engineer, you will design, build, and operate the test infrastructure that qualifies the mechanical hardware for next-generation enrichment technology. This includes precision optical mounts, alignment stages, beam delivery paths, and structures that must survive demanding thermal, vibration, shock, and material-compatibility conditions unique to uranium processing.
You will work hands-on with prototype and production hardware, designing fixtures and test setups from scratch. Key responsibilities include:
• Design, build, and maintain test fixtures, rigs, and setups for mechanical, thermal, vibration, shock, and durability testing of enrichment hardware, including precision optical and beam delivery assemblies.
• Develop and execute test plans that verify mechanical performance, alignment stability, and beam pointing/positioning accuracy under representative environmental and process conditions.
• Perform coupon- and component-level materials testing (fatigue, corrosion, wear, thermal cycling) to support material selection and qualification decisions.
• Instrument test articles and collect, reduce, and analyze test data to assess pass/fail criteria and identify design margins.
• Perform root-cause analysis on test failures and partner with design engineers to develop and verify corrective actions.
• Own test documentation, including test plans, procedures, reports, and qualification packages, ensuring traceability for engineering and regulatory purposes.
• Continuously improve test methods, tooling, and lab infrastructure to increase test throughput and fidelity as hardware iterates rapidly.
• Work closely with mechanical, optical, materials, manufacturing, and nuclear engineers to translate test results into design and process improvements.
You will operate in a fast-paced, Skunkworks-style environment with a lean, world-class team applying first-principles engineering to nuclear fuel production. The culture emphasizes urgency, accountability, and transparency.
REQUIREMENTS:
• Bachelor's degree in Mechanical Engineering or related field
• 3+ years of experience in mechanical test engineering, environmental test, or hardware qualification (via project team, research, internship, and/or professional experience)
• Hands-on experience designing and building test fixtures and instrumented test setups
• Working knowledge of environmental test methods (vibration, shock, thermal cycling, thermal vacuum, durability/fatigue)
• Comfortable working directly with hardware in a lab environment, including troubleshooting instrumentation and data acquisition systems
• Evidence of exceptional ability (prior projects, portfolio of work, completed products, etc.)
• Ability to work extended hours and weekends as necessary
PREFERRED:
• Background or working knowledge in materials science or metallurgy, particularly failure analysis, fatigue/corrosion testing, or performance of metals and alloys under extreme thermal, mechanical, or corrosive conditions
• Experience testing precision optical or photonic-based hardware (alignment stage repeatability, beam pointing/stability verification, thermal management validation for high-energy optical components)
• Experience with data acquisition systems, sensors (accelerometers, strain gauges, thermocouples), and test automation
• Strong understanding of engineering fundamentals and statistical methods for interpreting test data
• Experience in a fast-paced engineering environment or highly technical role requiring resourceful, entrepreneurial approach to complete tasks within tight timeframes or budget constraints
