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Nuclear Systems Engineer - Reactor Operations

El Segundo, California, United States

Radiant is an El-Segundo, CA-based clean energy startup building a nuclear microreactor. A climate-friendly alternative to diesel generators, Radiant's Kaleidos 1MW microreactor will be the world's first portable, zero-emissions power source that works anywhere. We plan to test our development reactor by 2026 and if successful, it will be the first new commercial reactor design to achieve a fueled test in over 50 years. Radiant's goal is to bring one of the world's first factory-constructed microreactors to market. Our microreactor can bring power to remote parts of the world and provide backup power for life-saving applications in hospitals or disaster-relief scenarios. 

Nuclear Systems Engineer

We are seeking a Systems Engineer to design and implement mission-critical procedures for reactor operators managing our groundbreaking nuclear microreactor technology. This role offers a rare opportunity to bridge engineering, operations, and human factors in a highly technical and regulated environment. You will collaborate with a multidisciplinary team to translate complex hardware and software designs into clear, executable, and DOE or NRC compliant procedures. Your work will ensure that Reactor Operators (ROs) and Senior Reactor Operators (SROs) can efficiently and safely execute test, commissioning, and operational activities.

This position goes beyond traditional systems engineering—you will also gain hands-on experience as a reactor operator, directly influencing the development of operational software, procedures, and digital twin simulations. Your contributions will enhance operator efficiency, safety, and real-world execution of our cutting-edge microreactors.

Responsibilities and Duties:

  • Develop and refine operational procedures that integrate both software and hardware-in-the-loop testing.
  • Collaborate closely with engineers to improve operator interfaces, procedural workflows, and software tools.
  • Qualify as an operator to gain firsthand experience, ensuring procedures align with real-world execution.
  • Support testing and iterative improvements of digital twin scenarios, operator systems, and human-machine interfaces.
  • Ensure compliance with DOE and NRC standards, maintaining strict formatting, clarity, and usability in procedural documentation.

Required Skills and Qualifications:

  • Undergraduate degree in engineering discipline.
  • 2+ years of full-time professional experience in engineering problem-solving, including system design, analysis, or testing.
  • Proficiency in managing or optimizing complex hardware and software processes for testing and operations.
  • Ability to apply first principles thinking to solve problems and make decisions in uncertain or ambiguous situations.

Desired Skills and Qualifications:

  • Hands-on experience in developing technical procedures, human factors engineering, or operational interface design.
  • Prior operations background such as mission control room operator. 
  • Background in highly regulated industries (e.g., nuclear, aerospace, aviation, maritime).
  • Proficiency in Python, UNIX, for procedure testing within the simulator environments.
  • Experience with human factors and user-centered instructions for operational workflows.

Additional Requirements:

  • Must be willing to work extended hours and weekends as necessary to achieve company goals.
  • Must work 100% onsite at El Segundo HQ.

Employee Benefits for Eligible Employees:

  • Stock: Substantial incentive stock plan for all full time, salaried 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 are offered as employee contributed benefits.
  • Free snacks and drinks onsite. 
  • Flexible PTO policy.

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 applicant’s capacity to serve in compliance with U.S. export controls.

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