Senior Controls Systems Engineer

About the role

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. Senior Controls Systems Engineer Radiant is seeking a Senior Controls Systems Engineer to lead the design, implementation, and validation of autonomous control systems for nuclear microreactors. In this role, you will own control system development end-to-end—from requirements definition through operational deployment—including algorithm development, modeling and simulation, embedded implementation, and system validation. You will design and integrate tightly coupled control functions spanning reactivity control, primary loop mass flow, alternator/generator speed, and multi-reactor coordination on microgrids. The ideal candidate is comfortable working within regulatory environments, developing autonomous and adaptive control strategies, and performing system-level analysis of nonlinear, coupled dynamic systems. This role requires close collaboration with multidisciplinary engineering teams responsible for hardware, software, and system integration. Responsibilities & Duties Serve as Responsible Engineer with full technical ownership of Kaleidos control systems, including generator, supervisory, and plant-level controls. Design and implement subsystem control architectures, including Reactor reactivity control mechanisms, Electrical power conversion and grid interface controls, Generator and alternator speed control (FOC, SVM) Develop control algorithms, embedded software, and analytic models to derive and flow down requirements to components and subsystems. Perform system-level modeling and analysis of coupled linear and nonlinear dynamics. Lead control system prototyping, simulation, hardware testing, validation, and verification activities. Develop and execute methods for analyzing control system performance, robustness, and stability. Review and analyze test data to validate control performance and inform design iteration. Author technical documentation and support regulatory review and licensing of control systems. Collaborate closely with mechanical, electrical, nuclear, and software engineering teams to ensure successful system integration. Required Qualifications & Skills Bachelor's and master's degree or higher in Electrical Engineering, Mechanical Engineering, Physics, Nuclear Engineering, or a related discipline. 5+ years of experience in dynamic system modeling, control algorithm development, simulation, testing, and auto-code generation using MATLAB/Simulink, including deployment to embedded targets. 5+ years of experience designing, implementing, and calibrating controllers for linear and nonlinear dynamic systems. Deep expertise in classical control theory, including: Stability analysis, On/off and PID control, Sliding mode control, Multivariable control, Gain scheduling, Reference tracking, bandwidth design, controllability, and observability analysis Hands-on experience designing controllers and observers for stochastic systems. Hands-on experience designing observers and estimators for linear and nonlinear systems. Experience modeling, simulating, and testing complex coupled dynamic systems. Expertise in Monte Carlo analysis, uncertainty quantification, and system identification. Familiarity with industrial and embedded communication protocols, including EtherNet/IP, EtherCAT, CANOpen, Ethernet, and RS-422/485. Desired Qualifications & Skills PhD in Electrical Engineering, Mechanical Engineering, Physics, Nuclear Engineering, or a related discipline. 7+ years of experience in control systems engineering. Hands-on experience designing motor controls, battery controls, power electronics control, Experience with autonomous system diagnostics, including fault detection, isolation, and recovery (FDIR). Experience with permanent magnet synchronous motor control, including FOC, VSM, and sensorless techniques. Experience with turbomachinery control, including turbines or jet engines. Experience with microgrid control and multi-source power systems. 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. 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. 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.