Senior Nuclear Systems Architect

Speedrun Talent Network; El Segundo (CA); On-site; USD 180,000 - 240,000; Full time

Benefits offered by this job

Stock plan

Medical plans

One Medical

Vision plan

Dental plan

Voluntary benefits

Parental leave

Education program

Free lunch

Flexible PTO

Team events

El Segundo HQ

Job summary

Radiant, based in El Segundo, CA, seeks a Staff Reactor Systems Engineer to own the technical integration of Kaleidos, a first-of-a-kind nuclear microreactor. You will translate product and safety requirements into subsystem specifications, managing interfaces and ensuring safe, testable, and producible performance.

You will collaborate across disciplines to resolve cross-system tradeoffs, establish systems engineering practices, and guide Kaleidos from development to scaled production, enabling

Qualifications

• Bachelor’s degree in engineering, physics, or a related technical discipline.
• 10+ years of professional engineering experience, including systems engineering, integration, testing, or technical leadership on complex hardware.
• Experience owning requirements and interfaces for a complex system from concept through build, test, and operation.
• Experience leading system-level trade studies and making decisions with incomplete information.
• Strong knowledge across disciplines like thermal-fluids, mechanical, structural, power systems, or controls.
• Experience with verification and validation, hazard and risk analysis methods (e.g., FMEA, FTA).
• Demonstrated technical leadership across multidisciplinary teams without formal authority.
• Strong written and verbal communication, including producing clear technical documents.

Responsibilities

• Own the Kaleidos system architecture and serve as technical authority for integrated system performance, safety, and reliability.
• Define and manage system budgets (thermal, mass, power, reactivity, and volume) and allocate margins across subsystems.
• Own interface definitions and interface control documents between subsystems.
• Maintain the technical baseline (requirements, configuration, change control, risk registers, and documentation).
• Identify cross-cutting risks early and drive them to resolution.
• Define the verification and validation strategy and partner with Test Engineering to turn requirements into tests.
• Correlate analysis and test results against system requirements and resolve discrepancies.
• Support safety-basis and licensing or regulatory documentation.
• Mentor engineers across the organization in systems thinking and interface discipline.
• Communicate system status, risks, and tradeoffs clearly to leadership.

Skills

System architecture

Requirements management

Interface definition

Cross-disciplinary collaboration

Systems thinking

Communication

Leadership without authority

Education

Bachelor’s degree in engineering/physics

Tools

FMEA

FTA

Job description

Radiant, based in El Segundo, CA, seeks a Staff Reactor Systems Engineer to own the technical integration of Kaleidos, a first-of-a-kind nuclear microreactor. You will translate product and safety requirements into subsystem specifications, managing interfaces and ensuring safe, testable, and producible performance.

You will collaborate across disciplines to resolve cross-system tradeoffs, establish systems engineering practices, and guide Kaleidos from development to scaled production, enabling