Mechanisms Engineer

Radiant Industries
El Segundo, CA
On-site

Who this role is best for

Best suited to mechanically inclined engineers with experience in complex system integration working in nuclear energy and advanced reactor development.

Best fit for

  • Mechanical engineers with a background in multi-component system design and iterative improvement
    — “Experience designing hardware that was manufactured, deployed, and iteratively improved.”
  • Professionals skilled in both hand calculations and finite element analysis for structural integrity
    — “Perform detailed thermomechanical analysis (static strength, durability/fatigue) and kinematic analysis to determine structural integrity and performance margins using both hand calculations and finite element tools.”
  • Candidates who can manage end-to-end development of subassemblies and supplier relationships
    — “Own subassembly design, manufacturing, and test schedules. Find and develop suppliers for components.”

Things to consider

  • This role requires full-time, on-site presence with no remote flexibility.
    — “Must work 100% onsite at El Segundo HQ.”
  • The position involves compliance with U.S. export controls, which may affect eligibility.
    — “This position involves access to technology that is subject to U.S. export controls.”

How to stand out

  • Highlight experience in actuator or valve mechanisms with performance validation.
    — “Ownership of critical mechanisms such as the control blade actuator or air jacket valves.”
  • Demonstrate ability to lead risk assessments for complex systems.
    — “Own risk analysis (FMEA) for subsystems.”
  • Emphasize clear communication skills and ability to collaborate across disciplines.
    — “Provide expertise and feedback to engineers in other functional areas via clear, constructive communication.”
  • Showcase proficiency in both CAD tools and finite element analysis platforms.
    — “Experience with design of multi-component assemblies in CAD (NX or similar).”
  • Demonstrate skill in deriving free-body diagrams for unfamiliar systems.
    — “Ability to derive free-body diagrams for systems with which one was not previously familiar.”
Pace · SteadyCollaboration · HighAutonomy · MediumDecision Impact · Company

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

  • mechanisms design
  • stress analysis
  • assembly and testing
  • risk analysis
  • collaboration with interdisciplinary teams
Typical background
mechanical engineeringaeronautical engineeringstress analysis

Skills & requirements

Required

Mechanisms DesignStress AnalysisFinite Element AnalysisMaterial SelectionAssembly And TestingRisk Analysis

Preferred

CAD DesignPneumatic SystemsElectromechanical ComponentsGD&TAi-assisted Automation

Stack & domain

Mechanisms DesignThermomechanical AnalysisKinematic AnalysisFinite Element Tools (abaqus, Ansys, Femap)CAD (NX)GD&TText-based Software Development ToolsPneumatic SystemsElectromechanical ComponentsManufacturing/assembly InstructionsTest PlansBill-of-materials (bom)Risk Analysis (fmea)CommunicationTeamworkProblem-solvingProject ManagementAttention To DetailSelf-motivationCollaborationTime ManagementAdaptabilityNuclear MicroreactorsPortable Nuclear PowerData CentersMilitary BasesSoftware EngineeringFactory-built MicroreactorsAI Tools

About the role

Original posting from Radiant Industries via Ashby

ABOUT RADIANT

Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt, fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development leverages modern software engineering to rapidly deliver safe, factory-built microreactors that use existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor at the Idaho National Laboratory this summer, with initial customer deliveries beginning in 2028.

ABOUT THE ROLE

Radiant is seeking a highly motivated Mechanisms Engineer to design and develop critical mechanisms within Kaleidos. You will solve unique challenges creating efficient and reliable mechanisms that control reactivity or actuate critical safety features. You will be responsible for the following: trade studies, material selection, detailed structural analysis, assembly, integration, and testing. You will have an instrumental impact of fueling the first new commercial reactor design in over 50 years by 2026.

Responsibilities & Duties:

  • Ownership of critical mechanisms such as the control blade actuator or air jacket valves.
  • Conduct trade studies and develop designs to meet program requirements.
  • Perform detailed thermomechanical analysis (static strength, durability/fatigue) and kinematic analysis to determine structural integrity and performance margins using both hand calculations and finite element tools.
  • Develop and execute manufacturing/assembly instructions and test plans.
  • Create and manage a Bill-Of-Materials (BOM).
  • Find and develop suppliers for components.
  • Own subassembly design, manufacturing, and test schedules.
  • Own risk analysis (FMEA) for subsystems.
  • Collect requirements, provide expertise and feedback to engineers in other functional areas via clear, constructive communication.

Required Qualifications & Skills:

  • Bachelor’s degree from an accredited institution in Mechanical or Aeronautical Engineering.
  • 3+ years of experience designing mechanisms.
  • 3+ years of experience performing stress analysis using both hand calculations and finite element tools (Abaqus, Ansys, FEMAP, or similar).

Desired Qualifications & Skills:

  • Experience with design of multi-component assemblies in CAD (NX or similar).
  • Experience designing hardware that was manufactured, deployed, and iteratively improved.
  • Experience designing pneumatic systems.
  • Experience integrating electromechanical components such as motors or encoders.
  • Experience working with interdisciplinary teams.
  • Solid understanding and application of GD&T.
  • Proficiency with both “hand calc” analytical methods and higher fidelity finite element-based analysis methods.
  • Ability to derive free-body diagrams for systems with which one was not previously familiar.
  • Self-motivated with strong organizational, written, and oral communication skills.
  • Experience with using text-based software development tools.

Additional Requirements:

  • Must be willing to work extended hours and weekends as necessary to accomplish our mission.
  • Must work 100% onsite at El Segundo HQ.

BENEFITS AND PERKS

  • Stock: Substantial incentive stock plan for all full-time employees.
  • Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.
  • One Medical: Sponsored memberships for employees and their dependents.
  • Vision: 100% top tier plan coverage + 50% for dependents.
  • Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.
  • Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.
  • 8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.
  • Daily catered lunch. Free snacks and drinks.
  • Flexible PTO policy. Remote workday allocation.
  • Company and team-bonding events, happy hours and in-person camaraderie.
  • Beautiful El Segundo headquarters close to the Pacific Ocean.

Total Compensation and Benefits

Radiant compensates people for impact and invests in those who continue to raise the bar. Radiant’s new hire compensation package includes base salary, substantial equity grants, and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance, experience, education, and qualifications, and are designed to support continued growth as scope, responsibility, and impact expand at Radiant.

The best of today’s advanced reactor builders don’t wait for job postings. They join the winning team. If that’s you, contact us directly for immediate opportunities: recruiting@radiantnuclear.com.

We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity or expression, pregnancy, age, national origin, disability status, genetic information, protected veteran status, or any other characteristic protected by law.

This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicant’s capacity to serve in compliance with U.S. export controls.

Source: Radiant Industries careers (Ashby)

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