Staff Nuclear Engineer

About the role

Radiant is seeking a Staff Nuclear Engineer to provide technical expertise across the nuclear design and analysis of its portable microreactor, Kaleidos. The role combines deep hands‑on analysis with technical ownership across major nuclear engineering workstreams.

Key responsibilities

• Provide technical leadership across reactor physics, core performance, shielding, dose, activation, thermal‑hydraulics, safety analysis, instrumentation & controls, and reactor operations.
• Own complex nuclear engineering projects from requirements capture through model development, analysis, technical review, and final documentation.
• Develop, review, and improve high‑fidelity neutron and radiation transport models for design, safety, testing, and regulatory evaluations.
• Lead multidisciplinary technical trades and establish rigorous practices for model verification, validation, peer review, and uncertainty evaluation.
• Collaborate with reactor systems, thermal, mechanical, electrical, test, operations, safety, and regulatory teams to resolve design challenges.

Required profile

• Bachelor’s degree in nuclear engineering or a related technical discipline.
• 8+ years of relevant nuclear engineering experience across reactor design, analysis, testing, licensing, safety, or operations.
• Demonstrated ability to operate independently on technically complex problems and drive work from definition through technical closure.
• Strong written and verbal communication skills for explaining complex analyses to multidisciplinary teams.

Required skills

• Deep knowledge of neutron transport theory and Monte Carlo simulation methods.
• Professional experience with MCNP, OpenMC, or comparable neutron and radiation transport codes.
• Familiarity with SCALE, Serpent, Shift, Griffin, MOOSE‑based applications.
• Proficiency in Python for simulation automation, model generation, and post‑processing.
• Understanding of reactor physics concepts such as criticality, reactivity coefficients, depletion, power distribution, and shutdown margin.

What we offer

• Substantial incentive stock plan for all full‑time employees.
• Comprehensive medical, vision, dental, and supplemental voluntary benefits.
• One Medical sponsored memberships for employees and dependents.
• On‑site work at Radiant’s El Segundo headquarters.