Lead Nuclear Engineer for Microreactor Design & Analysis

Radiant, Inc.; 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 plan

Dental plan

Parental leave

Lunch provided

Onsite HQ

Job summary

Radiant, Inc. in El Segundo, CA, seeks a Lead Nuclear Engineer to provide technical and people leadership across core physics, shielding, dose, and regulatory evaluation for Kaleidos.

You will guide nuclear engineering work from requirements through validation, while owning priorities and budgets. The role requires 5+ years in nuclear engineering, deep knowledge of neutron transport and MCNP/OpenMC, and on-site collaboration with cross-functional teams to deliver critical reactor analyses and

Qualifications

• Bachelor’s degree in nuclear engineering or a related technical discipline from an accredited institution.
• 5+ years of relevant nuclear engineering experience across reactor design, analysis, testing, licensing, safety, or operations.
• 1+ year of experience managing direct reports.
• Demonstrated experience leading complex nuclear engineering projects involving multiple technical disciplines and stakeholders.
• Deep knowledge of neutron transport theory, Monte Carlo simulation methods, nuclear data, and statistical convergence.
• Professional experience developing and applying MCNP, OpenMC, or comparable neutron and radiation transport models.
• Strong understanding of reactor physics concepts, including criticality, reactivity coefficients, depletion, power distribution, shutdown margin, neutron and gamma transport, and uncertainty analysis.
• Experience translating analytical results into reactor design decisions, technical requirements, safety conclusions, or regulatory documentation.
• Familiarity with model verification and validation, configuration control, peer review, and nuclear software quality practices.
• Strong written and verbal communication skills, including the ability to explain complex analyses, assumptions, uncertainties, and technical conclusions to multidisciplinary teams.

Responsibilities

• Lead an interdisciplinary team working across reactor physics, core performance, shielding, dose and activation, thermal-hydraulics, safety analysis, I&C, and reactor operations.
• Hire, manage, and develop a high-performing team of nuclear engineers through clear expectations, technical guidance, actionable feedback, and regular coaching.
• Establish team priorities, project plans, schedules, resource needs, budgets, and clear ownership for nuclear engineering deliverables.
• Own nuclear engineering projects from requirements capture and design iteration through model development, analysis, technical review, and final documentation.
• Guide analyses of criticality, reactivity control, shutdown margin, power distribution, depletion, temperature feedback, radiation transport, dose, activation, and shielding performance.
• Translate analytical results into actionable requirements and design decisions affecting the core, shielding, control systems, instrumentation, fluid systems, structures, and surrounding hardware.
• Establish rigorous practices for model verification and validation, peer review, configuration control, uncertainty evaluation, and technical documentation.
• Ensure analytical assumptions, limitations, uncertainties, margins, and conclusions are clearly documented and technically defensible.
• Collaborate with reactor systems, thermal, mechanical, electrical, test, operations, safety, and regulatory teams to resolve multidisciplinary design challenges.
• Work with the regulatory organization to translate applicable nuclear standards and requirements into analysis plans, design criteria, calculation packages, and verification activities.
• Support reactor testing and startup by defining analysis needs, instrumentation requirements, acceptance criteria, and methods for comparing predicted and measured performance.
• Identify technical and programmatic risks, develop practical mitigation plans, and drive complex nuclear engineering problems through closure.
• Communicate technical status, risks, decisions, and recommendations clearly to engineering teams and company leadership.

Skills

Nuclear engineering leadership

Neutron transport theory

Monte Carlo methods

Model verification & validation

Written and verbal communication

Regulatory documentation

Python or simulation tools

Education

Bachelor’s degree in nuclear engineering

Master’s degree or Ph.D. in nuclear engineering

Tools

MCNP

OpenMC

SCALE

Serpent

Shift

Griffin

MOOSE-based applications

Python

Job description

Radiant, Inc. in El Segundo, CA, seeks a Lead Nuclear Engineer to provide technical and people leadership across core physics, shielding, dose, and regulatory evaluation for Kaleidos.

You will guide nuclear engineering work from requirements through validation, while owning priorities and budgets. The role requires 5+ years in nuclear engineering, deep knowledge of neutron transport and MCNP/OpenMC, and on-site collaboration with cross-functional teams to deliver critical reactor analyses and