Lead Reactor Operations Engineer

About Radiant

Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s 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. Radiant’s 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.

As the Lead Reactor Operations Engineer, you will direct the team providing operational insights to ensure the development of Kaleidos and its functionality meet the requirements for safe, efficient, and reliable reactor operations and commissioning. This position will oversee and approve the development of reactor operating interfaces, conduct of operations, and procedures. You will also go one step further and qualify as a Kaleidos Reactor Operator yourself – always remaining technically hands on.

Responsibilities & Duties:

• Lead, mentor, and grow a team of Reactor Operations Engineers, setting technical priorities aligned with test, commissioning, and operational milestones.

• Qualify as an operator to gain firsthand experience and ensure the team's work aligns with real-world execution.

• Establish the conduct of operations and fleet monitoring processes for Kaleidos reactors.

• Support development of control algorithms for semi-autonomous and/or manual operations.

• Support the evaluation of integrated plant response to various events, accidents, and malfunctions.

• Participate in design reviews and provide feedback from an operations and maintenance perspective.

• Ensure all team deliverables meet DOE and NRC standards, maintaining strict formatting, clarity, and usability in procedural documentation.

• Recruit, hire, and develop engineering talent to scale the team with Radiant's growth.

Required Qualifications & Skills:

• 6+ years of full-time professional engineering experience, including system design, analysis, or testing, with 2+ years in a formal or informal technical leadership role.

• Familiarity with the interrelationships and dependencies of reactor systems, encompassing nuclear, mechanical, I&C and electrical systems - and their response as an integrated power plant system.

• Licensed as Senior Reactor Operator or Naval equivalent.

• Ability to apply first principles thinking to solve problems and make decisions in uncertain or ambiguous situations.

• Excellent written and verbal communication skills.

• Background in highly regulated industries (e.g., nuclear, aerospace, aviation, maritime).

• Demonstrated ability to lead and develop technical teams, managing and making decisions on risk, while remaining hands-on.

Desired Qualifications & Skills:

• Prior experience working as an operator in nuclear environments (e.g., nuclear energy, naval reactors, or radiation-controlled facilities), with familiarity in safety protocols, regulatory compliance, and high-reliability operations.

• 3+ years of full-time nuclear operations experience.

• Licensed as Senior Reactor Operator or Naval equivalent.

• Hands-on experience in developing technical procedures, human factors engineering, or operational interface design.

• Prior operations background such as mission control room operator.

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.

• Willingness to travel 50% - 60% of the time, as needed for projects.

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. Radiant’s 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 today’s advanced reactor builders don’t wait for job postings. They join the winning team. If that’s you, contact us directly for immediate opportunities: [email protected].

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.

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