Mechanical Engineer, Fluid Systems - 2026 New Graduate

Radiant Industries•El Segundo, CA

1d•Onsite

About The Position

Radiant is seeking a highly motivated Mechanical Engineer, Fluid Systems - 2026 New Graduate to join the KDU Engineering team. You will contribute directly to the design, assembly, and testing of the Kaleidos Development Unit (KDU) – the United States’ first new fueled reactor design in over 50 years. You will take ownership of projects that advance KDU’s readiness for fueled operations, working alongside a cross-disciplinary team of engineers.

Requirements

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.
Hands-on experience in design and build through projects, research, labs, or internships.
Proficiency with engineering tools (e.g., CAD, analysis software, lab instrumentation).

Nice To Haves

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.
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.

Responsibilities

Contribute to the design, analysis, and testing of KDU fluid subsystems.
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.

Benefits

Substantial incentive stock plan for all full-time employees.
100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans for Medical.
Sponsored memberships for employees and their dependents for One Medical.
100% top tier plan coverage + 50% for dependents for Vision.
100% top tier plan coverage, orthodontia extra, 50% for dependents for Dental.
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.