Mechanical Engineer, Mechanisms – 2026 New Graduate

Job Description

Mechanical Engineer, Mechanisms – 2026 New Graduate

Radiant is seeking a highly motivated Mechanical Engineer, Mechanisms – 2026 New Graduate to join the KDU Engineering team. This role offers a unique opportunity to contribute directly to the design, assembly, and testing of the Kaleidos Development Unit (KDU), which is the United States’ first new fueled reactor design in over 50 years. As part of a cross-disciplinary team, you will take ownership of projects aimed at advancing KDU’s readiness for fueled operations.

Responsibilities and Duties

• Contribute to the design, analysis, and testing of KDU mechanisms.
• 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 Skills And Qualifications

• Education: BS in Mechanical Engineering, Aerospace Engineering, or a related discipline (completed or expected Spring 2026).
• Engineering Fundamentals: Strong foundation in engineering first principles, including but not limited to thermodynamics, fluid mechanics, statics, dynamics, and strength of materials.
• Hands-on Experience: Practical experience in design and build gained through projects, research, labs, or internships.
• Technical Proficiency: Proficiency with engineering tools such as CAD, analysis software, and lab instrumentation.

Desired Skills And Qualifications

• Advanced Education: MS in Mechanical Engineering, Aerospace Engineering, or related discipline (completed or in progress).
• Mechanisms Experience: Prior internship, co-op, or project-based experience related to mechanisms.
• Problem-Solving: Ability to independently solve complex engineering tasks and proactively seek out resources.
• Startup Mindset: Comfortable working in a fast-paced, startup environment with a collaborative, mission-driven mindset.
• Mission Alignment: Excitement for Radiant’s mission to rapidly deploy nuclear microreactors to remote locations requiring abundant, clean energy.
• Specialized Knowledge: Knowledge of reactor physics is helpful but not required.

Additional Requirements

• Location: This role is based onsite at Radiant’s HQ in El Segundo, CA.
• Work Schedule: Extended hours or occasional weekend work may be required to support project milestones.
• Export Controls: This position involves access to technology subject to U.S. export controls. Any job offer will be contingent upon the applicant’s capacity to serve in compliance with U.S. export controls.
• Visa Sponsorship: Unfortunately, Radiant is unable to provide visa sponsorship for this position.

Benefits And Perks

• Equity: Substantial incentive stock plan for all full-time employees.
• Medical: 100% coverage up to base silver level plan for employees + 50% for 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, with orthodontia extra, 50% for dependents.
• Voluntary Benefits: Voluntary life, accident, hospital, critical illness, commuter, and FSA/HSA are offered as employee-contributed benefits.
• Parental Leave: 8 weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.
• Food & Drink: Daily catered lunch, free snacks and drinks.
• Time Off: Flexible PTO policy and remote workday allocation.
• Culture: Company and team-bonding events, happy hours, and in-person camaraderie.
• Location: Beautiful El Segundo headquarters close to the Pacific Ocean.

Total Compensation And Benefits

Radiant compensates based on impact and invests in employees who consistently raise the bar. The 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.

Compensation Range: $95,000 – $105,000

Application Information

Radiant is an equal opportunity employer. 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.

If you are a top advanced reactor builder and wish to join the winning team, contact us directly for immediate opportunities: recruiting@radiantnuclear.com.