Radiant Industries
El Segundo, California
Job Description Job Description 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. About the Role We are seeking a Reactor Operations 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 fast-paced 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 (RO), directly influencing the development of operational software, procedures, and future reactor designs. Responsibilities & Duties: Qualify as an operator to gain firsthand experience, ensuring procedures align with real-world execution. Collaborate closely with engineers to improve operator interfaces, procedural workflows, and software tools. 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. Develop and refine operational procedures that integrate both software and hardware-in-the-loop testing. Required Qualifications & Skills: 4+ 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. Background in highly regulated industries (e.g., nuclear, aerospace, aviation, maritime). 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 2+ 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. 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 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: . 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. Compensation Range: $106,500 - $146,475
Job Description Job Description 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. About the Role We are seeking a Reactor Operations 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 fast-paced 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 (RO), directly influencing the development of operational software, procedures, and future reactor designs. Responsibilities & Duties: Qualify as an operator to gain firsthand experience, ensuring procedures align with real-world execution. Collaborate closely with engineers to improve operator interfaces, procedural workflows, and software tools. 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. Develop and refine operational procedures that integrate both software and hardware-in-the-loop testing. Required Qualifications & Skills: 4+ 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. Background in highly regulated industries (e.g., nuclear, aerospace, aviation, maritime). 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 2+ 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. 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 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: . 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. Compensation Range: $106,500 - $146,475
Radiant Industries
El Segundo, California
Job Description Job Description 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. Radiant is seeking a highly motivated Reactor Operations Engineer to join the team. Responsibilities: Develop and refine operational procedures that integrate both software and hardware-in-the-loop testing. 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. Collaborate closely with engineers to improve operator interfaces, procedural workflows, and software tools. 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. Qualifications: BS or MS in Mechanical Engineering, Nuclear Engineering, Aerospace Engineering, or a related discipline. Graduating in December 2026 or Spring 2027. 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 Qualifications: Hands-on experience in developing technical procedures, human factors engineering, or operational interface design. Proficiency in Python, UNIX, for procedure testing within the simulator environments. Experience with human factors and user-centered instructions for operational workflows. 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: . 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. Compensation Range: $105K - $130K
Job Description Job Description 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. Radiant is seeking a highly motivated Reactor Operations Engineer to join the team. Responsibilities: Develop and refine operational procedures that integrate both software and hardware-in-the-loop testing. 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. Collaborate closely with engineers to improve operator interfaces, procedural workflows, and software tools. 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. Qualifications: BS or MS in Mechanical Engineering, Nuclear Engineering, Aerospace Engineering, or a related discipline. Graduating in December 2026 or Spring 2027. 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 Qualifications: Hands-on experience in developing technical procedures, human factors engineering, or operational interface design. Proficiency in Python, UNIX, for procedure testing within the simulator environments. Experience with human factors and user-centered instructions for operational workflows. 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: . 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. Compensation Range: $105K - $130K
Radiant Industries
El Segundo, California
Job Description Job Description 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. About the Role Radiant is seeking a Principal Turbomachinery Engineer to serve as the Responsible Engineer for the turbomachinery within our nuclear-driven power generation system. This role owns the mechanical design, integrity, and performance of the core rotating assembly at the heart of our 1MW closed-loop Brayton cycle. You will define and drive the mechanical architecture of high-speed rotating hardware operating at extreme temperatures, pressures, and rotational speeds. As a deeply technical individual contributor, you will set direction for rotor dynamics, structures, bearings, seals, and system integration while working closely with electrical, thermal, and manufacturing teams. This is a hands-on, high-ownership role focused on technical excellence, sound engineering judgment, and delivering reliable, production-ready turbomachinery. Responsibilities & Duties: Technical Ownership & System Architecture Serve as Responsible Engineer for the turbomachinery mechanical system. Own the mechanical architecture and design strategy for high-speed rotating assemblies (up to 30 krpm). Lead rotor dynamics, structural integrity, and life analysis for rotating components and assemblies. Define and flow down requirements from system-level constraints including thermal, structural, and operational environments. Make key technical decisions on rotor layout, shafting, bearings, seals, materials, and clearances. Ensure designs meet performance, reliability, safety, and regulatory requirements. Establish and uphold standards for mechanical design rigor, analysis quality, and documentation. Mechanical Design & Analysis Lead detailed design of turbomachinery components including rotors, shafts, housings, and support structures. Test and validate rotordynamic systems, driving model correlation, risk reduction, and performance verification. Perform and review structural and thermal analysis to ensure integrity under high-speed and high-temperature operation. Define tolerances, fits, stack-ups, and alignment strategies for precision rotating assemblies. Partner with electrical engineering on alternator rotor integration, including electromagnetic and structural coupling. Cross-Functional Integration Partner closely with turbomachinery aero, motor design, thermal, manufacturing, and test teams. Ensure seamless integration between turbine, compressor, and alternator subsystems. Drive clear interface definitions across mechanical, electrical, and thermal boundaries. Collaborate with manufacturing to ensure designs are producible, inspectable, and scalable. Engage with suppliers on technically critical components and design decisions. Prototyping, Testing & Validation Support assembly, integration, and test of turbomachinery hardware. Define validation strategies including spin testing, thermal testing, and system-level operation. Lead root cause analysis and drive design iteration for test failures or performance gaps. Remain hands-on in hardware bring-up, troubleshooting, and refinement. Technical Influence Act as a subject matter expert in turbomachinery mechanical design and rotating systems. Provide technical guidance and design reviews across the team without direct people management responsibility. Influence engineering direction through deep expertise, data-driven decisions, and strong judgment. Contribute to technical roadmap, risk identification, and mitigation strategies. Required Qualifications & Skills: B.S. in Mechanical Engineering or related field. 8+ years of experience designing high-speed rotating machinery (turbines, compressors, or similar systems). Deep expertise in structural analysis and mechanical design of turbomachinery. Experience with bearings, seals, and high-speed shafting design. Expert-level proficiency with analysis tools (e.g., ANSYS) and advanced use of NX and Teamcenter for complex design, simulation, and product lifecycle management. Strong understanding of tolerancing, GD&T, and precision mechanical assembly. Experience owning hardware through design, build, and test cycles. Hands-on experience with assembly, integration, and troubleshooting of turbomachinery. Strong system-level thinking and mechanical intuition. Excellent engineering judgment and decision-making capability. Ability to influence without authority across cross-functional teams. Clear communicator capable of articulating complex technical concepts. High ownership mindset and accountability for hardware outcomes. Ability to operate effectively in a fast-paced, first-of-a-kind development environment. Desired Qualifications & Skills: 10+ years of turbomachinery or rotating equipment experience. M.S. or Ph.D. in Mechanical Engineering. Experience with closed-loop Brayton cycle systems or similar energy systems. Familiarity with high-temperature materials and extreme environment design. Experience integrating mechanical systems with high-speed electric machines. Prior experience as a Responsible Engineer for complex hardware. Experience scaling hardware from prototype to production. 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: . 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. Compensation Range: $200,500 - $314,475
Job Description Job Description 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. About the Role Radiant is seeking a Principal Turbomachinery Engineer to serve as the Responsible Engineer for the turbomachinery within our nuclear-driven power generation system. This role owns the mechanical design, integrity, and performance of the core rotating assembly at the heart of our 1MW closed-loop Brayton cycle. You will define and drive the mechanical architecture of high-speed rotating hardware operating at extreme temperatures, pressures, and rotational speeds. As a deeply technical individual contributor, you will set direction for rotor dynamics, structures, bearings, seals, and system integration while working closely with electrical, thermal, and manufacturing teams. This is a hands-on, high-ownership role focused on technical excellence, sound engineering judgment, and delivering reliable, production-ready turbomachinery. Responsibilities & Duties: Technical Ownership & System Architecture Serve as Responsible Engineer for the turbomachinery mechanical system. Own the mechanical architecture and design strategy for high-speed rotating assemblies (up to 30 krpm). Lead rotor dynamics, structural integrity, and life analysis for rotating components and assemblies. Define and flow down requirements from system-level constraints including thermal, structural, and operational environments. Make key technical decisions on rotor layout, shafting, bearings, seals, materials, and clearances. Ensure designs meet performance, reliability, safety, and regulatory requirements. Establish and uphold standards for mechanical design rigor, analysis quality, and documentation. Mechanical Design & Analysis Lead detailed design of turbomachinery components including rotors, shafts, housings, and support structures. Test and validate rotordynamic systems, driving model correlation, risk reduction, and performance verification. Perform and review structural and thermal analysis to ensure integrity under high-speed and high-temperature operation. Define tolerances, fits, stack-ups, and alignment strategies for precision rotating assemblies. Partner with electrical engineering on alternator rotor integration, including electromagnetic and structural coupling. Cross-Functional Integration Partner closely with turbomachinery aero, motor design, thermal, manufacturing, and test teams. Ensure seamless integration between turbine, compressor, and alternator subsystems. Drive clear interface definitions across mechanical, electrical, and thermal boundaries. Collaborate with manufacturing to ensure designs are producible, inspectable, and scalable. Engage with suppliers on technically critical components and design decisions. Prototyping, Testing & Validation Support assembly, integration, and test of turbomachinery hardware. Define validation strategies including spin testing, thermal testing, and system-level operation. Lead root cause analysis and drive design iteration for test failures or performance gaps. Remain hands-on in hardware bring-up, troubleshooting, and refinement. Technical Influence Act as a subject matter expert in turbomachinery mechanical design and rotating systems. Provide technical guidance and design reviews across the team without direct people management responsibility. Influence engineering direction through deep expertise, data-driven decisions, and strong judgment. Contribute to technical roadmap, risk identification, and mitigation strategies. Required Qualifications & Skills: B.S. in Mechanical Engineering or related field. 8+ years of experience designing high-speed rotating machinery (turbines, compressors, or similar systems). Deep expertise in structural analysis and mechanical design of turbomachinery. Experience with bearings, seals, and high-speed shafting design. Expert-level proficiency with analysis tools (e.g., ANSYS) and advanced use of NX and Teamcenter for complex design, simulation, and product lifecycle management. Strong understanding of tolerancing, GD&T, and precision mechanical assembly. Experience owning hardware through design, build, and test cycles. Hands-on experience with assembly, integration, and troubleshooting of turbomachinery. Strong system-level thinking and mechanical intuition. Excellent engineering judgment and decision-making capability. Ability to influence without authority across cross-functional teams. Clear communicator capable of articulating complex technical concepts. High ownership mindset and accountability for hardware outcomes. Ability to operate effectively in a fast-paced, first-of-a-kind development environment. Desired Qualifications & Skills: 10+ years of turbomachinery or rotating equipment experience. M.S. or Ph.D. in Mechanical Engineering. Experience with closed-loop Brayton cycle systems or similar energy systems. Familiarity with high-temperature materials and extreme environment design. Experience integrating mechanical systems with high-speed electric machines. Prior experience as a Responsible Engineer for complex hardware. Experience scaling hardware from prototype to production. 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: . 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. Compensation Range: $200,500 - $314,475