Senior Manufacturing Engineer

About Radiant Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. Rising energy demand is straining the U.S. grid and driving up utility costs, emissions, and interconnection backlogs. Radiant decentralizes energy, producing power close to where it’s used. Its first reactor, Kaleidos, is a factory-built, 1-megawatt, fail-safe microreactor that can be transported by land, sea, or air and runs up to 5 years without refueling.

Deployed locally without a decade-long build or permitting fight, Kaleidos provides independent power for critical infrastructure like military bases, data centers, hospitals, and remote sites. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Air Force, Navy, and has pre-order agreements with Equinix, with deployments beginning in 2028.About the Role Radiant is seeking a Senior Manufacturing Engineer to help transition Kaleidos from a first-of-a-kind reactor build into a repeatable, scalable production system.

With the initial Kaleidos reactor build complete, Radiant is now applying what we learned through design, fabrication, assembly, integration, and test to the next generation of the product. This includes reducing mass and part count, improving manufacturability and assembly, increasing production repeatability, and developing the processes, tooling, equipment, suppliers, and quality controls required to manufacture reactors at  this role, you will work closely with design, quality, test, supply chain, and operations engineers to influence hardware from the earliest stages of design through fabrication and final assembly.

You will own manufacturing processes for critical reactor components, mechanisms, structures, and integrated assemblies, ensuring designs can be built safely, reliably, and repeatedly while meeting demanding performance and quality requirements.

You will be expected to identify manufacturing constraints early, drive DFM and DFA into the product, develop and qualify production processes, and close the loop between engineering intent and what happens on the factory floor. The ideal candidate is equally comfortable reviewing a CAD model with a design engineer, developing a fixture or manufacturing process, troubleshooting a build issue, working with a supplier, and using production data to improve the next iteration of the product.

This is a hands-on engineering role with significant influence over how Kaleidos evolves from a development program into a manufacturable product.

Responsibilities & Duties Own manufacturing and inspection processes for critical Kaleidos components, mechanisms, structures, and assemblies from design release through fabrication, integration, and final acceptance.

Partner closely with design engineers to drive design for manufacturability and assembly (DFM/DFA), influencing hardware to reduce mass, part count, manufacturing complexity, assembly time, and production risk.

Evaluate designs for manufacturability, inspectability, tolerance stack-up, tooling access, assembly sequence, subsystem integration, and final reactor assembly.

Develop, qualify, document, and continuously improve manufacturing processes for complex mechanical hardware and integrated assemblies.

Translate engineering drawings, CAD models, requirements, and specifications into manufacturing plans, work instructions, inspection strategies, tooling requirements, and production controls.

Define fabrication and assembly approaches for new hardware, including process selection, sequencing, make-versus-buy decisions, and inspection methodology.

Design and develop production tooling, fixtures, assembly aids, lifting equipment, and other manufacturing equipment required to safely and repeatably build reactor hardware.

Partner with Quality and Test Engineering to establish inspection and acceptance strategies, resolve build and test issues, and incorporate lessons learned into future hardware and processes.

Investigate manufacturing defects, nonconformances, and assembly issues using structured root-cause analysis and implement durable corrective actions.

Identify, evaluate, and develop suppliers for critical components and manufacturing processes, working directly with suppliers to mature fabrication methods and resolve technical issues.

Identify and implement capital equipment, machinery, and production infrastructure needed to support current builds and future production volumes.

Support hands-on build,…