Nuclear Engineer - 2026 New Graduate
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 failsafe microreactor that can be transported anywhere power is needed and run for up to five years without the need to refuel. 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's unique, practical approach to nuclear development utilizes modern software engineering to rapidly achieve safe, factory-built microreactors that leverage existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor next year at the Idaho Laboratory, with initial customer deliveries beginning in 2028.
Nuclear Engineer - New Graduates
Radiant is seeking a highly motivated early career nuclear engineer to design and analyze nuclear systems for a 1MW HTGR nuclear microreactor. You will have the opportunity for mentorship from experienced engineers in a fast-paced startup environment while taking great ownership of projects end-to-end. You will be responsible for various aspects of the nuclear design and analysis as priorities shift and expertise is gained. Build your nuclear career at Radiant and be a key contributor to testing the first new reactor design in over 50 years by 2026.
Responsibilities & Duties
Ownership of Nuclear design and analysis, examples:
Shielding: Transport, Operational, Self-Activation and environmental Activation, Waste Categorization, working with both customer and regulatory requirements
Run coupled neutronics and thermal calculations to refine the thermal model in various scenarios
Mechanical: Assess damage effects and bulk material properties changes due to high flux on ceramics and metals inside the core
Neutronics: Develop control schemes and design control systems using transient simulations to finalize source sizing and detector selection
Fuel and Waste: Model burnup distribution, design burnable absorber, and perform criticality assessments for transport and waste facility compatibility
Develop requirements for hardware systems, structures, and components
Create and manage a Bill-Of-Materials (BOM).
Find and develop suppliers for all components.
Own subassembly design, manufacturing, and test schedules.
Collect requirements, provide expertise and feedback to engineers in other functional areas via clear, constructive communication.
Required Qualifications & Skills
Bachelor's degree in nuclear engineering or equivalent degree from accredited institution
Proficient in at least one of the following programming : Python, C++, C#, or another scientific computing
Desired Qualifications & Skills
Self-motivated with strong organizational, written, and oral communication skills
Competency in distributed software development process
Hands-on experience designing hardware and/or performing tests
Related experience with OpenMC, Serpent, MCNP, MOOSE, BISON, RELAP, CFD, Pronghorn, GRIFFIN, or other nuclear software packages
At least 1 year of software development experience:
C, C++, or Python development experience is .
Prior use of code repositories, unit testing, performance benchmarking, and software review / release processes.
Familiarity with good documentation practices and implementation of style guidelines.
Additional Requirements:
Must be willing to work extended hours and weekends as necessary to accomplish our mission.
Must work 100% onsite at El Segundo HQ.
Total Compensation and Benefits
Radiant's new hire compensation package includes base salary, substantial equity grants, and comprehensive benefits. Total compensation and level are determined through a holistic evaluation of your interview performance, experience, education, and qualifications.
Benefits and Perks for Eligible Employees:
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 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.
We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to , , , , , or expression, , , , status, genetic information, protected veteran status, or any other characteristic protected by law.
Unfortunately, we are unable to provide visa sponsorship at this time.
This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicant's capacity to serve in compliance with U.S. export controls.