2026 New Graduate - Mechanical Engineer at Radiant in El Segundo, CA

Summary: Radiant is seeking a highly motivated New Graduate Mechanical Engineer to join the KDU Engineering team. You will contribute directly to the design, assembly, and testing of the Kaleidos Development Unit (KDU), working alongside a cross-disciplinary team of engineers. Responsibilities: - Contribute to the design, analysis, and testing of KDU subsystems (fluid systems, mechanisms, or structural components) - Take ownership of deliverables from concept through build and validation, with guidance from senior engineers - Collaborate across disciplines to integrate designs and resolve technical challenges - Support system-level testing, troubleshooting, and design iteration to accelerate KDU development - Communicate results through design reviews, technical reports, and presentations to peers and leadership Required Qualifications: - BS in Mechanical Engineering, Aerospace Engineering, or a related discipline (completed or expected Spring 2026) - Strong foundation in engineering first principles, including thermodynamics, fluid mechanics, statics, dynamics, and strength of materials - Hands-on experience in design and build through projects, research, labs, or internships - Proficiency with engineering tools (e.g., CAD, analysis software, lab instrumentation) - This role is based onsite at Radiant's HQ in El Segundo, CA - Extended hours or occasional weekend work may be required to support project milestones Preferred Qualifications: - MS in Mechanical Engineering, Aerospace Engineering, or related discipline (completed or in progress) - Prior internship, co-op, or project-based experience related to fluid systems, mechanisms, or structures - Ability to independently solve complex engineering tasks and seek out resources proactively - Comfortable working in a fast-paced, startup environment with a collaborative, mission-driven mindset - Excitement for Radiant's mission to rapidly deploy nuclear microreactors to remote locations requiring abundant, clean energy - Knowledge of reactor physics is helpful but not required Required Skills: Mechanical Engineering, Fluid Mechanics, Thermodynamics Important Skills: CAD, Strength of Materials Benefits: 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.