---
title: 'Senior Build Engineer, Turbomachinery at Radiant Industries'
canonical: 'https://feeny.ai/job/senior-build-engineer-turbomachinery-radiant-industries-el-segundo-m5wssr3vpxve'
type: 'job'
last_seen: '2026-11-09'
---

# Senior Build Engineer, Turbomachinery at Radiant Industries

- **Company:** [Radiant Industries](https://feeny.ai/companies/radiant-industries)
- **Location:** El Segundo, CA
- **Compensation:** $158k–$219k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-11-09
- **Last confirmed live:** 2026-11-09
- **Apply:** https://jobs.ashbyhq.com/radiant-industries/13d25280-e5c4-4401-a65d-c73859ade990/application

**Skills:** GD&T, Mechanical drawings interpretation, CAD models, Turbomachinery systems, Rotating machinery assembly, Precision assembly, Rotor balancing, Bearing handling, Nuclear energy experience

> The Build Engineer assembles and integrates high-speed turbomachinery hardware for a nuclear microreactor program. This hands-on role involves developing assembly instructions, supporting test and validation teams, and ensuring first-article readiness through precise mechanical construction and troubleshooting.

## Job description

## 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 highly motivated Senior Build Engineer to lead the assembly, integration, and build execution of high-performance turbomachinery systems for our portable nuclear microreactor. This is a hands-on engineering role requiring strong mechanical fundamentals, precision assembly experience, and the ability to independently solve complex hardware challenges. You will take ownership of prototype and first-article turbomachinery builds, working closely with design, manufacturing, and test teams to translate engineering designs into functional, test-ready hardware. This role will be instrumental in developing assembly processes, resolving integration challenges, and improving hardware reliability and build repeatability as we advance toward production.

Responsibilities & Duties: Turbomachinery Build & Integration

- Lead hands-on assembly, integration, and troubleshooting of complex turbomachinery hardware, including compressors, turbines, rotors, electric motors, bearings, seals, and housings.
- Own precision assembly operations, including rotor stacking, bearing installation, balancing, alignment, and mechanical fit-up.
- Interpret engineering drawings, GD&T, tolerance stack-ups, and mechanical specifications to ensure proper assembly and hardware functionality.
- Identify and resolve assembly challenges involving tight tolerances, component interfaces, alignment, and mechanical interference.
- Drive first-article build execution, ensuring hardware meets engineering requirements and is ready for testing and validation.

Build Process Development & Tooling

- Develop, implement, and refine assembly processes, work instructions, alignment procedures, and torque specifications for complex rotating machinery.
- Design and develop custom assembly tooling, fixtures, and work-holding solutions to improve build efficiency, precision, and repeatability.
- Evaluate assembly methods, identify process improvements, and establish best practices for transitioning prototype builds toward repeatable production processes.
- Maintain detailed build documentation, including as-built configurations, inspection results, nonconformances, and lessons learned.

Technical Problem-Solving & Cross-Functional Collaboration

- Partner closely with design, manufacturing, and test engineers to resolve hardware integration challenges and improve design for manufacturability and assembly.
- Lead root cause investigations and corrective actions for assembly defects, mechanical failures, and hardware nonconformances.
- Provide technical feedback on component design, tolerances, material selection, and assembly interfaces to improve hardware performance and reliability.
- Support hardware testing, including pre-test inspections, post-test teardown, failure investigations, and implementation of design or process improvements.
- Provide technical guidance and mentorship to junior engineers and technicians, establishing high standards for precision assembly, workmanship, and build quality.

Required Qualifications & Skills

- Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or a related engineering discipline.
- 5+ years of relevant experience in mechanical assembly, hardware integration, manufacturing, or build engineering involving complex mechanical systems.
- Demonstrated hands-on experience assembling, integrating, and troubleshooting precision mechanical hardware.
- Strong understanding of GD&T, tolerance stack-ups, mechanical fits, fasteners, torque requirements, and alignment principles.
- Proficiency in reading and interpreting complex engineering drawings, assembly documentation, and 3D CAD models.
- Experience developing assembly procedures, troubleshooting hardware issues, and improving build processes.
- Strong mechanical aptitude and first-principles problem-solving skills, with the ability to independently resolve complex technical challenges.
- Ability to work effectively across design, manufacturing, and test engineering teams in a fast-paced hardware development environment.

Desired Qualifications & Skills

- Direct experience with turbomachinery, gas turbines, compressors, high-speed rotating equipment, or power generation systems.
- Experience with precision rotor assembly, dynamic balancing, bearing installation, shaft alignment, and high-speed rotating machinery.
- Familiarity with precision measurement and inspection techniques, including dial indicators, micrometers, bore gauges, and other metrology equipment.
- Experience designing or developing custom assembly fixtures, tooling, and mechanical ground support equipment.
- Familiarity with rotor dynamics, thermal growth, bearing preload, interference fits, and mechanical clearances.
- Experience supporting first-article builds, prototype development, hardware testing, and design iteration.
- Experience transitioning complex hardware from engineering development to repeatable production processes.
- Prior nuclear industry experience is not required.

Additional Requirements

- Must be willing to work extended hours and occasional weekends to support critical build and test schedules.
- Must work 100% onsite at Radiant's El Segundo headquarters.

## 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.
- Nuclear Engineering Certificate Program: 100% covered educational program with Penn State University, for eligible employees, to rapidly upscale into nuclear.
- 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 full-time 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: recruiting@radiantnuclear.com.

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.

## About Radiant Industries

## Company Overview
- **One-liner**: Radiant Industries is building the world’s first mass‑produced, portable nuclear microreactor (Kaleidos) to replace diesel generators with zero‑emission, resilient power for remote sites, hospitals, data centers, and military installations.
- **Entity Type**: Private (Series D – $300M raised in December 2025, led by Lockheed Martin Ventures)
- **Headquarters**: El Segundo, California, USA
- **Founded**: 2020 (some sources list 2019)
- **Founders**: Not publicly disclosed

## Core Business
- **Primary industry**: Nuclear electric power generation / clean energy
- **Target customers**: B2B – remote communities, hospitals, data centers, military bases, industrial sites that currently rely on diesel generators or unstable grids
- **Mission**: To bring one of the world’s first factory‑constructed microreactors to market, providing portable, zero‑emissions power anywhere, anytime.

## Products & Services
- **[Kaleidos Microreactor](https://www.radiantnuclear.com/)**: A 1 MW electric / 1.9 MW thermal portable nuclear reactor packaged in a shipping container. It uses helium gas cooling and TRISO fuel (meltdown‑proof ceramic uranium particles). Delivered by truck or aircraft, installed without site excavation, and can reach full power the next day. After 5+ years the entire container is returned to the factory for refueling; up to four fuel cycles yield a 20‑year product lifetime. Customers purchase via Power Purchase Agreements (PPAs) or direct unit sales.

## Market Standing
- **Valuation / Market Cap**: Not disclosed
- **Key Metric**: Total funding raised – **$622.6M** (as of early 2026)
- **Notable Investors/Partners**: Andreessen Horowitz (led Series B), Lockheed Martin Ventures (led Series D), plus 18+ other investors across Series B, C, and D rounds
- **Growth Signals**:
  - Headcount grew **141% YoY** to 157 employees (as of mid‑2026)
  - 64 active job postings (+178% YoY)
  - Plans to test its development reactor in **2026** – which would be the first new commercial reactor design to achieve a fueled test in over 50 years
  - Initial customer deployments targeted for **2028**
  - SBIR Phase II awards from the U.S. Air Force for nuclear microreactor installation energy resilience

## Competitive Advantages
- **Portability & speed**: Delivered in a standard shipping container, installed in one day, no on‑site water or excavation needed.
- **Passive safety**: TRISO fuel is meltdown‑proof; the core is cooled by natural convection (air jacket) without pumps.
- **Factory‑built, factory‑refueled**: No nuclear waste or infrastructure left on site after the container is returned.
- **High energy density**: Over 110× the energy density of existing diesel systems.
- **Fleet monitoring**: Hundreds of units can be monitored 24/7 from a centralized control center.

## Strategic Focus
- Complete fueled testing of the Kaleidos prototype in 2026.
- Secure regulatory approvals (special nuclear material license, Part 7 license).
- Scale manufacturing for initial customer deployments beginning in 2028.
- Expand into military, commercial, and humanitarian markets (disaster relief, remote microgrids, backup power).

## Why Work Here
- **Culture & mission**: High‑impact climate tech – directly replacing diesel generators with clean nuclear power. Rated 5.0/5.0 on employer reviews (5 reviews) with strong scores for culture (4.7) and career growth (4.8).
- **Work location**: On‑site in El Segundo, CA (steps from the Pacific Ocean, near downtown). Employees work from a physical office.
- **Perks**: Company equity, relocation assistance, free daily meals, commuter benefits, onsite parking, generous parental leave, family medical leave, onsite Mother’s Room, dental/health insurance, FSA.
- **Diversity & inclusion**: Mandated unconscious bias training; hiring practices that promote diversity.
- **Tech stack**: React, TypeScript, Python, C++, C#, Kubernetes, Docker, PostgreSQL, AWS, Ansys, SolidWorks, Altium, and more. Engineers work on cutting‑edge nuclear, mechanical, and embedded systems.
- **Growth trajectory**: 141% headcount growth in the past year; 64 open roles across engineering, regulatory, supply chain, and operations.

## Sources
1. [radiantnuclear.com](https://www.radiantnuclear.com/) – Product details, specs, deployment model
2. [builtin.com](https://builtin.com/company/radiant) – Company overview, perks, culture, tech stack, reviews
3. [linkedin.com](https://www.linkedin.com/company/r-a-d-i-a-n-t) – Funding, headcount, employee growth, locations, key executives
4. [sbir.gov](https://www.sbir.gov/portfolio/1655711) – SBIR awards, Phase II contracts with U.S. Air Force
5. [jobs.ashbyhq.com](https://jobs.ashbyhq.com/radiant-industries) – Current open positions (64+)

## Other roles at Radiant Industries

- [Staff Nuclear Engineer](https://feeny.ai/job/staff-nuclear-engineer-radiant-industries-el-segundo-yx5h3evqz8w6) — El Segundo, CA
- [Program Development Lead](https://feeny.ai/job/program-development-lead-radiant-industries-el-segundo-dat68x1gvag2) — El Segundo, CA
- [Senior Operations Associate](https://feeny.ai/job/senior-operations-associate-radiant-industries-el-segundo-tyvmyj7b34nr) — El Segundo, CA
- [Principal Thermal Modeling Engineer](https://feeny.ai/job/principal-thermal-modeling-engineer-radiant-industries-el-segundo-9kfh14wgzf1p) — El Segundo, CA
- [Principal Turbomachinery Engineer](https://feeny.ai/job/principal-turbomachinery-engineer-radiant-industries-el-segundo-t79km8ymbgam) — El Segundo, CA
- [Site Lead](https://feeny.ai/job/site-lead-radiant-industries-el-segundo-s3eqh34jwg06) — El Segundo, CA
- [Staff Regulatory Engineer](https://feeny.ai/job/staff-regulatory-engineer-radiant-industries-el-segundo-bsm92yhympbx) — El Segundo, CA
- [Senior Regulatory Engineer](https://feeny.ai/job/senior-regulatory-engineer-radiant-industries-el-segundo-nr50jybcam8n) — El Segundo, CA
- [Director of Regulatory Affairs](https://feeny.ai/job/director-of-regulatory-affairs-radiant-industries-washington-zcqq77x6texk) — Washington, DC
- [Staff Turbomachinery Engineer](https://feeny.ai/job/staff-turbomachinery-engineer-radiant-industries-el-segundo-xepvcqf8gbzg) — El Segundo, CA