Lead Nuclear Engineer – Monte Carlo & Microreactor (Onsite)

Radiant; El Segundo, Northern (CA, KY); Hybrid; USD 180,000 - 240,000; Full time

Benefits offered by this job

Stock options

Medical plan

One Medical

Vision coverage

Dental coverage

Life insurance

Parental leave

Catered lunch

Flexible PTO

Team events

El Segundo HQ proximity

Job summary

Radiant, based in El Segundo, CA, seeks a Principal Nuclear Engineer to lead interdisciplinary nuclear engineering work for Kaleidos. You will guide design trades, model development, and regulatory documentation while mentoring engineers across multiple disciplines.

Ideal candidates have deep neutron transport expertise (Monte Carlo), experience with MCNP/OpenMC, and a proven track record of technical leadership in reactor design and safety analysis.

Qualifications

• Bachelor’s degree in nuclear engineering or related technical field.
• 9+ years of relevant nuclear engineering experience across reactor design, analysis, testing, licensing, safety, or operations.
• Demonstrated experience leading complex nuclear engineering projects and multidisciplinary teams.
• Experience hiring, mentoring, or technically leading nuclear engineers.
• Deep knowledge of neutron transport theory, Monte Carlo methods, nuclear data, and statistical convergence.
• Experience with MCNP/OpenMC or comparable neutron transport models.

Responsibilities

• Lead an interdisciplinary team across reactor physics, core performance, shielding, dose, and safety analysis.
• Establish technical priorities, project plans, and ownership across the organization.
• Serve as a technical authority for neutron transport and Monte Carlo methods.
• Own projects from requirements to documentation and testing.
• Guide analyses of criticality, shutdown margin, power distribution, and radiation transport.
• Translate analytical results into actionable design decisions for core and systems.
• Establish rigorous model verification, validation, and documentation practices.
• Collaborate with reactor systems, thermal, mechanical, electrical, and regulatory teams.
• Translate standards into analysis plans, calculation packages, and verification activities.
• Support reactor testing, instrumentation requirements, and startup activities.
• Identify risks and mentor engineers through guidance and coaching.

Skills

Nuclear engineering

Reactor design

Monte Carlo methods

Neutron transport

Leadership & mentoring

Regulatory documentation

Python

Education

Bachelor’s degree in nuclear engineering

Master’s degree or Ph.D. (preferred)

Tools

MCNP

OpenMC

Griffin

SCALE

Job description

Radiant, based in El Segundo, CA, seeks a Principal Nuclear Engineer to lead interdisciplinary nuclear engineering work for Kaleidos. You will guide design trades, model development, and regulatory documentation while mentoring engineers across multiple disciplines.

Ideal candidates have deep neutron transport expertise (Monte Carlo), experience with MCNP/OpenMC, and a proven track record of technical leadership in reactor design and safety analysis.