Principal Electrical Engineer, Integration & Test

About Radiant

Radiant is an El Segundo, CA-based company building the world's only mass-produced, transportable nuclear microreactors. The U.S. grid is under growing strain, with power demand accelerating, driving higher utility costs, rising carbon emissions, and interconnection backlogs. Radiant has a solution, transportable, on-site power. Our first reactor, Kaleidos, is 1 megawatt: small enough to be factory-built, transported by land, sea, or air, and deployed wherever power is needed. 1 MW can power 1000 homes for five years. Ship it back and we refuel for a 20 year operating life. We made energy a product that can be used for critical infrastructure like military bases, data centers, hospitals, and remote sites, as well as the commercial main street businesses that keep America running. Founded in 2020, Radiant is under contract to deliver power to the U.S. Army, Navy and Air Force and has signed pre-order agreements with Equinix, with deployments beginning in 2028.

About the Role

Radiant is seeking a Principal Electrical Engineer to lead the electrical system architecture and test infrastructure for Kaleidos, our commercial microreactor targeted for deployment in 2028. You will own end-to-end electrical integration, from architecture and requirements definition through hardware bring-up, testing, and commissioning, and lead the development of Hardware-in-the-Loop (HIL) systems and the broader test environment that validates the reactor before it reaches the field. As the technical authority across electrical integration and validation strategy, you will set direction independently while collaborating across mechanical, software, and systems engineering. You will define the electrical architecture behind the first commercialized portable microreactor as we begin deploying to our customers in 2028.

Responsibilities & Duties:

• Build the HIL platform from the ground up: plant simulation, real hardware in the loop, and the test environment Kaleidos ultimately ships from.

• Own the design, build, and maintenance of electrical test infrastructure, establishing it as a foundational asset for validating the commercial unit ahead of 2028.

• Define and own electrical and software integration requirements across power distribution, signal conditioning, sensor mapping, actuator interfaces, and device simulation.

• Own the communication layer between hardware, control systems, and software protocol selection, timing, and fault behavior at the boundaries.

• Define and drive the electrical validation strategy, developing the test procedures and methodologies the program depends on.

• Own schedule, budget, and vendor management for electrical hardware and integration activities.

• Drive automation and tooling improvements, with real influence over how the team tests.