Summer 2026 Internship - Nuclear Engineer
About The Position
Radiant is seeking a highly motivated Nuclear Engineering Intern to support the design and analysis of nuclear systems for a 1MW HTGR nuclear microreactor. As part of the engineering team, you will work alongside experienced nuclear engineers and gain hands-on experience in areas such as neutronics, thermal-hydraulics, shielding, and fuel analysis. This internship offers direct mentorship in a fast-paced startup environment, providing you with a unique opportunity to contribute to the development of the first new fueled reactor design in over 50 years. Please note: we plan to begin interviewing for Summer 2026 internships in November/December.
Requirements
- Currently pursuing a bachelor’s or master’s degree in nuclear engineering or a related discipline.
- Strong academic foundation in nuclear engineering principles (e.g., reactor physics, thermal-hydraulics, radiation shielding).
- Proficiency in at least one programming language (Python, C++, C#, or similar).
Nice To Haves
- Hands-on experience through coursework, research, projects, or labs in nuclear system design or analysis.
- Familiarity with nuclear simulation codes (e.g., OpenMC, Serpent, MCNP, MOOSE, BISON, RELAP, CFD, Pronghorn, GRIFFIN).
- Prior software development experience or exposure to version control, testing, or documentation practices.
- Strong communication skills and ability to work in a collaborative team environment.
- Enthusiasm for Radiant’s mission to rapidly deploy nuclear microreactors to provide clean energy in remote locations.
Responsibilities
- Assist with nuclear design and analysis tasks, including shielding, neutronics, thermal, and fuel-related studies.
- Support coupled neutronics and thermal calculations to refine system performance models.
- Document methods, results, and findings in clear technical reports and presentations.
- Collaborate with cross-functional teams and provide technical input as projects evolve.
- Support the development of lower order shielding analysis models to develop rapid shielding design solutions.
- Support the development of uncertainty propagation methodology and its execution on the Kaleidos Demonstration Unit
- Perform criticality safety analysis for the Production Plant of Kaleidos reactors
- Present a final project review at the end of internship to engineers and leadership
Benefits
- Stock: Substantial incentive stock plan for all full-time employees.
- Medical: 100% premium coverage for base Silver level plan for employee + 50% premium coverage for dependents. Platinum plans available.
- One Medical: Sponsored memberships for eligible employees and their dependents.
- Vision: 100% premium coverage for top tier plan + 50% for dependents.
- Dental: 100% premium coverage for top tier plan (including orthodontia) + 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.
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What This Job Offers
Career Level
Intern
Number of Employees
101-250 employees
