About Radiant

Radiant is an El Segundo CA-based startup building the worlds first mass-produced portable nuclear microreactors. The companys first reactor Kaleidos is a 1-megawatt fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals data centers remote sites and military bases. Radiants unique practical approach to nuclear development leverages modern software engineering to rapidly deliver safe factory-built microreactors that use existing well-qualified materials. Founded in 2020 Radiant is on track to test its first reactor at the Idaho National Laboratory this summer with initial customer deliveries beginning in 2028.

About the Role

Radiant is seeking a technical and people-oriented Lead Nuclear Engineer for our nuclear design and analysis group focused in areas such as core physics shielding instrumentation & controls and reactor operations. You will lead a high-performing team through the design development and test stages of the Kaleidos microreactor. You will own the schedule budget hiring and execution of nuclear-related milestones with a key focus on safety reliability portability and performance. The ideal candidate is comfortable in interdisciplinary environments working cross-functionally with engineers and leadership is fluent in engineering first principles has tenacious creative problem-solving abilities and keen to get to the solution of a problem and loves to mentor and motivate engineers to deliver their best work. You will play a critical role in driving the first portable nuclear microreactor to market.

Responsibilities & Duties:

• Manage an interdisciplinary team of nuclear engineers focused in areas such as safety analyses core performance shielding including operational dose activation shutdown dose I&C operations thermal-hydraulics and more.

• Hire lead and grow a high performing team of nuclear engineers.

• Own nuclear engineering projects end to end including requirement capture multi-disciplinary design iteration simulation pipeline development analysis post-processing and summarization for regulatory deliverables.

• Collaborate with regulatory team on nuclear industry standards and requirements.

• Mentor engineers through actionable feedback and coaching.

Required Qualifications & Skills:

• Bachelors degree in nuclear engineering or equivalent degree from accredited institution.

• 5 years nuclear engineering industry experience with relevant software use including MCNP and/or OpenMC.

• Deep knowledge of neutron transport and Monte Carlo simulation theory.

• 1 year managing direct reports.

Desired Qualifications & Skills:

• Masters or PhD in nuclear engineering or equivalent degree from accredited institution.

• Subject matter expert in one of following areas: safety analysis shielding instrumentation and controls reactor operations and/or radioactive material transportation.

Additional Requirements:

• Must be willing to work extended hours and weekends as necessary to accomplish our mission.

• Must work 100% onsite at El Segundo HQ.

Benefits and Perks

• Stock: Substantial incentive stock plan for all full-time employees.

• Medical: 100% up to base silver level plan for employee 50% dependents offers up to Platinum plans.

• One Medical: Sponsored memberships for employees and their dependents.

• Vision: 100% top tier plan coverage 50% for dependents.

• Dental: 100% top tier plan coverage orthodontia extra 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.

Total Compensation and Benefits
Radiant compensates people for impact and invests in those who continue to raise the bar. Radiants new hire compensation package includes base salary substantial equity grants and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance experience education and qualifications and are designed to support continued growth as scope responsibility and impact expand at Radiant.

The best of todays advanced reactor builders dont wait for job postings. They join the winning team. If thats you contact us directly for immediate opportunities: .

We are an equal opportunity employer and all qualified applicants will receive consideration for employment without regard to race color religion sex sexual orientation gender identity or expression pregnancy age national origin disability status genetic information protected veteran status or any other characteristic protected by law.

Unfortunately we are unable to provide visa sponsorship at this time.

This position involves access to technology that is subject to U.S. export controls. Any job offer made will be contingent upon the applicants capacity to serve in compliance with U.S. export controls.

Required Experience:

IC