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Radiant is building the world's first mass-produced, portable nuclear microreactors. The company's flagship product, Kaleidos, is a 1-megawatt, fail-safe microreactor designed for rapid deployment to hospitals, data centers, remote sites, and military bases. Founded in 2020 and headquartered in El Segundo, CA, Radiant is preparing to test its first reactor at Idaho National Laboratory with initial customer deliveries expected in 2028.
As Senior Nuclear Engineer, you will own the modeling methods and reactor physics calculations that form the foundation of Radiant's Digital Twin simulation software. This is a critical technical role directly supporting the commercialization of the first mass-produced nuclear reactor.
Key responsibilities include:
- Developing and owning neutronics modeling methods and reactor physics calculations for transient safety analyses
- Performing calculations of energy deposition distributions, reactivity coefficients, kinetics parameters, and control blade worths
- Verifying assumptions and assessing conservatism of neutronics models
- Documenting methods for both technical and non-technical audiences
- Supporting Verification & Validation efforts for the Digital Twin
- Reviewing and supporting other nuclear analyses across the company in reactor physics, shielding, and radiation detection
Required qualifications: Bachelor's degree in nuclear engineering or related field; 4+ years of experience with Monte Carlo nuclear engineering software (OpenMC, MCNP, Serpent, SCALE, or similar); experience documenting analysis methods and assumptions; strong programming skills (preferably Python).
Desired qualifications include reactor kinetics knowledge, thermal hydraulic principles, and experience communicating with cross-functional teams. The role requires 100% onsite work at El Segundo headquarters and willingness to work extended hours as needed.
Compensation includes base salary, substantial equity grants, and comprehensive benefits (medical, dental, vision, 8 weeks paid parental leave, flexible PTO, catered lunches, and team events).
