2027 New Graduate - Mechanical Engineer

About the role

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 leverages modern software engineering to rapidly deliver safe, factory‑built microreactors using 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.

Responsibilities

• Contribute to the design, analysis, and testing of the microreactor.
• 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.

Qualifications

• BS or MS in Mechanical Engineering, Aerospace Engineering, or a related discipline.
• Graduating in December 2026 or Spring 2027.
• 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).

Benefits

• Substantial incentive stock plan for all full‑time employees.
• Medical: 100 % coverage up to base silver level plan for employee; 50 % for dependents, with options 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 (employee‑contributed).
• 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 and remote‑workday allocation.
• Company and team‑bonding events, happy hours, and in‑person camaraderie.
• Beautiful El Segundo headquarters close to the Pacific Ocean.

Pay

Compensation range: $105,000 – $130,000. Radiant’s new‑hire package includes base salary, substantial equity grants, and comprehensive health benefits. Total compensation is determined through a rigorous evaluation of interview performance, experience, education, and qualifications, and is designed to support continued growth as scope, responsibility, and impact expand.