Test Engineer, Numenor (Reactor)

The Team

The Numenor team is building Valar's next reactor, the flagship program that will define how we deliver nuclear power at scale. This dedicated team owns the entire plant, from the reactor core and helium systems to cooling, plant modules, and the Citadel, uniting mechanical, systems, safety, IC&E, quality, and supply chain under one mission. The work starts with bringing the first unit to life and ends with a production line that delivers reactors faster with every build. What this team builds will power the critical infrastructure of the future.

The Role

Valar Atomics seeks a Test Engineer for the reactor program. This role will design and build test stands, run test campaigns, and turn raw data into the evidence that proves Numenor's hardware meets its design basis. You will test components and systems such as control rod mechanisms, helium systems, and plant modules, from early development through integrated testing and commissioning on the first unit, then help build the repeatable acceptance testing that lets every unit after it ship faster.

The role sits at the intersection of hardware, data, and compliance, and demands someone who is hands-on and hardware-first while bringing the rigor and traceability that nuclear work requires.

Key Responsibilities

Test Stand Design and Execution

• Design, build, and maintain test stands for performance, reliability, endurance, environmental, and qualification testing.
• Develop test plans, profiles, and procedures with design engineers and the V&V team.
• Run tests, monitor live data, and adjust parameters to capture meaningful results.

Data Acquisition and Integration

• Set up and maintain data acquisition systems, including remote and unattended capability.
• Integrate test stand data streams with SCADA and historian infrastructure.
• Process raw test data into clean, usable formats for engineering analysis and reporting.

Troubleshooting and Diagnostics

• Troubleshoot instrumentation, test stand hardware, and data acquisition faults during test execution.
• Analyze test data to diagnose root causes and turn findings into design recommendations.

Build, Test and Commissioning

• Support integrated system testing and commissioning through first operation.
• Develop standardized acceptance tests so each unit is verified faster than the last.

Reporting and Compliance

• Prepare clear, accurate test reports and maintain traceable records of procedures, configurations, and results.
• Present test results and methodology to government regulators and auditors as needed.
• Work closely with mechanical, systems engineering, safety, IC&E, and quality so test results feed directly into the plant design.

Basic Qualifications

• Bachelor's degree in Mechanical, Electrical, or Aerospace Engineering or a related field, or equivalent hands-on experience.
• 2+ years of test engineering experience on hardware.
• Experience designing and building test stands or test fixtures.
• Familiarity with data acquisition systems, sensors, and instrumentation.
• Working knowledge of Python, MATLAB, SQL, or similar tools for data handling and analysis.
• Strong troubleshooting mindset, with the ability to diagnose issues from data.
• Clear written and verbal communication, including presenting technical results to non-technical or regulatory audiences.

Preferred Skills and Experience

• Experience with SCADA and historian systems.
• Testing of high-temperature, high-pressure, or gas systems, such as helium, pressure vessels, or heat exchangers.
• Mechanism, actuator, or qualification testing.
• Test experience on first-of-a-kind hardware in aerospace, power generation, oil and gas, or defense.
• Experience preparing documentation for regulatory review or compliance audits.
• Nuclear industry experience: commercial, defense, or national laboratory. A plus, not a prerequisite.

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