About Radiant

Radiant is an El Segundo, CA-based company building the world's only mass-produced, transportable nuclear microreactors. The U.S. grid is under growing strain, with power demand accelerating, driving higher utility costs, rising carbon emissions, and interconnection backlogs. Radiant has a solution, transportable, on-site power. Our first reactor, Kaleidos, is 1 megawatt: small enough to be factory-built, transported by land, sea, or air, and deployed wherever power is needed. 1 MW can power 1000 homes for five years. Ship it back and we refuel for a 20 year operating life. We made energy a product that can be used for critical infrastructure like military bases, data centers, hospitals, and remote sites, as well as the commercial main street businesses that keep America running. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Navy and Air Force and has signed pre-order agreements with Equinix, with deployments beginning in 2028.

About the Role

Radiant is seeking a highly motivated Senior Mechanical Engineer, Mechanisms 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.

4+ years of experience designing mechanisms.

4+ 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.