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 Stress Engineer to own and execute structural loads, vibration, and dynamic analyses for complex mechanical systems associated for Kaleidos, the world's first portable microreactor and supporting hardware. You will play a critical role in ensuring structural integrity and survivability across all phases of the product lifecycle, including manufacturing, transportation, handling, deployment, and operational environments.

This role requires a hands-on engineer who is comfortable working in ambiguous, fast-paced environments and collaborating closely with structures, mechanical design, thermal, nuclear, and test teams.

Responsibilities & Duties

Develop and own static, dynamic, and transient loads for reactor systems, support structures, and transport configurations.

Perform structural dynamics analyses, including modal, random vibration, shock, sine vibration, and fatigue assessments.

Implement explicit dynamics simulations to model nonlinear reactor response under transient seismic and transportation event cases.

Define and analyze transportation and handling environments, including shock and vibration from road, rail, air, or sea transport.

Generate load cases and environments to support structural sizing, design margins, and verification plans.

Conduct finite element analyses (FEA) using tools such as ANSYS, Abaqus, or similar tools.

Collaborate with design engineers to influence hardware architecture, material selection, and joint design.

Support test planning and correlation, including shaker tests, modal surveys, and structural verification testing.

Develop and maintain analysis documentation, reports, and requirements for internal reviews and regulatory interfaces.

Contribute to failure investigations, root cause analyses, and design improvements

Help establish best practices for loads, dynamics, and structural verification within a growing engineering organization.

Required Qualifications & Skills

Bachelor’s degree in Mechanical Engineering, Aerospace Engineering, Structural Engineering, or a related field.

4+ years of professional experience in stress, loads, dynamics, or structural analysis for complex mechanical systems.

Strong fundamentals in structural mechanics, dynamics, and vibration.

Experience with finite element modeling and analysis of metallic and composite structures.

Proficiency with industry-standard FEA tools (e.g., ANSYS, Abaqus, Nastran).

Familiarity with design allowables, safety factors, and margin-of-safety methodologies.

Ability to work cross-functionally and communicate analysis results clearly to both technical and non-technical stakeholders.

Desired Qualifications & Skills

Experience in aerospace, launch, defense, nuclear, or heavy industrial hardware environments.

Dynamics modeling software experience (LD-Dyna, Abaqus explicit, or other).

Background in shock and vibration testing and test-article correlation.

Knowledge of fatigue, fracture mechanics, and bolted joint analysis.

Experience defining or interpreting environmental specifications and requirements.