Full-Time
Test Engineer
Mechanical/Fluids
Radiant
501-1,000 employees
Develops nuclear microreactors for portable power
Compensation Overview
$106.5k - $146.5k/yr
El Segundo, CA, USA
In Person
Must work 100% on-site at the El Segundo headquarters.
Bachelor's
 QA & Testing (1) |
|---|
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- At least 2 years of full-time professional experience in engineering problem-solving, including system design, analysis, or testing.
- A bachelor's degree from an accredited institution in mechanical engineering, manufacturing engineering, or another related engineering discipline.
- Ability to apply first-principles thinking to solve problems and make decisions in uncertain or ambiguous situations.
- Background in highly regulated industries such as nuclear, aerospace, aviation, or maritime.
- Demonstrated ability to lead projects and work independently.
- Strong technical fundamentals in fluids and thermodynamics.
- Strong written and verbal communication skills.
- Flexible and adaptable approach, with the ability to seek out requirements with minimal direction.
- Willingness to work extended hours and weekends as necessary.
- Ability to work 100% on-site at the El Segundo headquarters.
- Capacity to serve in compliance with United States export controls as a condition of employment.
- Perform testing as a Test Conductor or Test Director to gain firsthand experience and ensure procedures align with real-world execution.
- Partner with design engineers to develop test methods for complex mechanisms and structures.
- Support testing and iterative improvements of fluid, electrical, and structural hardware for the Kaleidos reactor through development, qualification, and acceptance testing.
- Identify and develop appropriate suppliers for component sourcing and fabrication.
- Drive continuous-improvement initiatives in test processes and data-delivery quality.
- Support one-off test campaigns in a fast-paced, minimum-requirements environment to reduce hardware risk.
- Ensure compliance with Department of Energy and Nuclear Regulatory Commission standards while maintaining strict formatting, clarity, and usability in procedural documentation.
- Assist with test planning and execution, risk identification and mitigation, hardware integration for test campaigns, post-test inspections, data review, and hardware performance analysis.
- Contribute to the development of operational software, procedures, and test ground support equipment.
- Prior experience working as an operator in fast-paced test environments, such as rocket engine testing, turbopump testing, or component-level testing, with familiarity in safety protocols, high-reliability operations, high-pressure gases, safety engineering, Failure Modes, Effects, and Criticality Analysis, and keep-out zones.
- Experience designing, fabricating, or operating fluid systems.
- Knowledge of instrumentation including pressure transducers, thermocouples, resistance temperature detectors, and accelerometers.
- Ability to read and interpret engineering standards, technical requirements, and engineering drawings, including ASME B31.3, ASME B31.1, and ASME Boiler Code Sections III and VIII.
- Hands-on experience developing technical procedures.
- Experience reviewing test data and analyzing hardware performance.
- Prior operations experience designing and commissioning test ground support equipment, including test fixtures, fluid systems, and electrical systems.
- Proficiency with Ion, Epsilon3, NX Computer-Aided Design, and Teamcenter.
- Experience with Beckhoff programmable logic controllers.
Radiant Nuclear develops compact nuclear microreactors, notably the Kaleidos reactor, to provide portable, reliable power for remote locations and military use. The system uses a CO2-based power cycle to generate electricity from a small reactor, enabling a compact, robust power source suitable for challenging environments. Radiant differentiates itself through a team of SpaceX veterans and a clear focus on compactness, efficiency, and turbomachinery-driven power generation, with early traction from government contracts (e.g., a $3.8 million DoD award) and partnerships with private sector investors. The company’s goal is to supply sustainable, portable nuclear energy to government and industrial clients, accelerating adoption of microreactor technology for frontline, remote, and strategic applications.
Company Size
501-1,000
Company Stage
Series D
Total Funding
$620.7M
Headquarters
El Segundo, California
Founded
2019
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Simplify's Take
What believers are saying
- NRC accepted R-50 Part 70 review on May 5, 2026, speeding licensing.
- Air Force selected Radiant for Buckley on April 22, 2026, opening procurement pathways.
- More than $300 million funding and Lockheed Martin investment finance factory buildout and testing.
What critics are saying
- NRC review ends December 18, 2026; a denial delays R-50 and investor confidence.
- Kaleidos depends on TRISO fuel, INL testing, and 2028 delivery; any failure breaks commercialization.
- A reactor accident or community opposition at Buckley Space Force Base can kill deployment plans.
What makes Radiant unique
- Radiant Industries is the only 2026 full-power, commercial microreactor tester at INL's DOME.
- R-50's Tennessee factory strategy targets mass-produced Kaleidos reactors, not bespoke one-off builds.
- Lockheed Martin Ventures and DoD backing validate defense-first demand for portable nuclear power.
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Benefits
Health Insurance
Dental Insurance
Vision Insurance
Stock Options
Unlimited Paid Time Off
One Medical
Growth & Insights and Company News
6 month growth
↑ 7%1 year growth
↑ 1%2 year growth
↑ 3%Antares fetches $470M to move on military base reactor push. Stay Connected Find opportunities - and win them. July 28, 2026 03:07 PM ET The three-year-old startup wants to get ahead of the government's own deadline for operating a nuclear reactor on military property. Antares, a nuclear power startup that designs small modular reactors, has completed a $470 million Series C capital raise to move ahead on efforts to build those systems for U.S. military bases. For Antares, this new financing round announced Tuesday comes a mere seven months after the three-year-old company closed a $96 million Series B raise ahead of a key demonstration for the Idaho National Laboratory. Paradigm and Caffeinated Capital led the Series C round with participation from Industrias Ventures, Point72 Ventures and Shine Capital. Nuclear power is of keen interest to government agencies and commercial enterprises, as well as investors, amid rising electricity demand from data center operators and others that run artificial intelligence workloads. Antares' Mark-0 reactor achieved criticality on June 4 at INL in what the company touts as the first time in four decades that a privately-developed, non-light-water reactor achieved such a designation. Antares is also one of three finalists in a Defense Department initiative for testing small modular reactors at Air Force bases in Colorado and Montana. Radiant Industries and Westinghouse are competing with Antares for selection under the Advanced Nuclear Power for Installation program. The winner will work with the Air Force to have advanced nuclear reactor operating on at least one of the service branch's installation by 2030 or sooner. "On June 4th, we won the race to criticality, and now we've shifted to the race to commercialization," Jordan Bramble, CEO and co-founder of Antares, said in a release. "The military has been a partner to us every step of the way. We've secured firm contracts to build reactors." Antares describes its government customer network as including the Air Force, Space Force, Defense Innovation Unit and NASA. "Our deep customer relationships and committed orderbook allow us to focus our engineering roadmap on one simple thing from here on out - reactors that operate reliably and safely for 6+ years deployed to military installations as soon as 2028," Bramble added. The $470 million Series C figure breaks out to $370 million in equity and $100 million in debt, which Antares will use to accelerate its path from demonstrating its reactor to fielding by 2028. Sept. 30, 2028 also represents a deadline set forth by President Trump's Executive Order 14299 for DOD to begin operating a reactor at a domestic military installation. Antares is eyeing 2027 as the year for the Mark-1 reactor to begin producing electricity.
Radiant on track to build the first commercial nuclear microreactors factory in America. May 5, 2026 7:41 AM Gift Article NRC Launches Accelerated Review of 10 CFR Part 70 License for R-50 Production Facility in Tennessee EL SEGUNDO, CA / ACCESS Newswire / May 5, 2026 / The U.S. Nuclear Regulatory Commission (NRC) has formally accepted for review the Radiant's 10 CFR Part 70 license application for its R-50 Production Facility in Tennessee. The NRC will review the application on an expedited timeline with a goal of completing its work within eight months, approximately 55% faster than the standard schedule for this type of review. This marks a major regulatory milestone and is a first for the microreactor industry, and a key indicator that America is on the cusp of an energy revolution. "This accelerated review reflects the NRC's commitment to enabling advanced reactor technologies while maintaining our broader effort to improve efficiency and upholding our rigorous safety standards," NRC Chairman Ho K. Nieh said in an NRC press release announcing the acceptance. "Thank you Chairman Nieh for your alignment with this administration's goal to rapidly deploy nuclear reactors. We have been working every day to validate our design, process, and product. Five years of development, thousands of man hours, and hundreds of pages of technical information, testing, repeated results, and documentation have led to this moment," said Dr. Rita Baranwal, Chief Nuclear Officer at Radiant Industries. "We are grateful to the NRC for their continued support and engagement, and believe this acceptance review approval, in conjunction with the May 1, 2026 Notice of Public Review for 10 CFR Part 57, demonstrates the NRC's commitment to delivering on the President's Executive Orders and supporting an evolving nuclear industry." NRC Part 70 is one of the biggest regulatory hurdles for a nuclear energy company to establish a production facility. It enables the use of fuel in the microreactor manufacturing process, which is a key step toward establishing the R-50 Production Facility as a cornerstone of advanced nuclear reactor development. Radiant is committed to meeting the highest standards of safety, security, and regulatory compliance as Tricityherald work to bring this critical capability online. The NRC's acceptance confirms that Radiant's application is sufficiently complete for detailed technical review. This step initiates the agency's comprehensive evaluation of the R-50 facility's design, safety basis, and operational programs under the requirements of 10 CFR Part 70, which governs the possession and use of special nuclear material. The R-50 Production Facility is designed to support Radiant's mission to deliver reliable, scalable, and innovative nuclear power for use everywhere. Once licensed and operational, the facility will support assembly, production, and testing of the company's Kaleidos reactors using highly resilient TRISO fuel. Radiant will continue to collaborate closely with the NRC throughout the review process and anticipates ongoing engagement as the agency conducts its safety, environmental, and technical evaluations. About Radiant Industries: Radiant Industries is a leading developer of advanced nuclear technologies focused on delivering clean, resilient, and scalable energy solutions. Through innovation in reactor design, fuel production, and systems engineering, Radiant is committed to enabling a new generation of nuclear applications for commercial, industrial, and defense customers. Media Contact:
The US Nuclear Regulatory Commission has accepted Radiant Industries' licence application for its R-50 Production Facility in Tennessee, marking the first such review for the microreactor industry. The NRC will complete its review within eight months, approximately 55% faster than the standard timeline. The 10 CFR Part 70 licence enables the use of fuel in the microreactor manufacturing process, a crucial regulatory milestone for establishing the facility. Once operational, the Tennessee plant will support assembly, production and testing of Radiant's Kaleidos reactors using TRISO fuel. The expedited review reflects the NRC's commitment to enabling advanced reactor technologies whilst maintaining safety standards. Radiant has submitted five years of development work and technical documentation for the review process.
Plugged in | may 2026. May 14, 2026 Maine Gov. Mills vetoes data Center moratorium bill. Maine Gov. Janet Mills vetoed a bill establishing the country's first statewide moratorium on data centers. It sought to prevent construction until November 2027. MISO capacity prices fall as new supply outpaces demand growth. Capacity offered by the Midcontinent Independent System Operator increased 3.4% to 141 GW from 136.3 GW a year driven by solar, gas and battery storage connections. Fusion energy group seeks PJM connection for first commercial power plant. Commonwealth Fusion Systems submitted an application to connect its ARC plant to the PJM Interconnection becoming the first U.S-based fusion firm to apply to join a major power grid operator. A new thermal battery could help this Minnesota campus electrify heat. The University of Minnesota and Cache Energy have installed a thermal battery unit that transforms electricity into intense heat to efficiently run a steam heating system. Full throttle: five trends reshaping the gas power boom. Natural gas is experiencing a massive surge in development driven by rising electricity demand. Five trends are shaping this development. Clean energy program for businesses, data Center campuses gets green light in Georgia. The Georgia Power Service Commission has voted to allow data centers and other large load customers to identify and commit to paying for solar, battery, and other renewable energy projects to supply their own power needs. Kentucky power's Transmission Line rebuild project slated to begin this summer. The Kentucky Public Service Commission has approved the construction of the Prestonsburg-Thelma Transmission Line that will rebuild roughly 14 miles of transmission line to 69-KV standards providing reliable power to the region. DOE names first four Nuclear Energy Launch Pad developers. The Department of Energy and National Reactor Innovation Center has announced four developers for the Nuclear Energy Launch Pad including Deployable Energy, General Matter, NuCube Energy in partnership with Idaho State University and Radiant Nuclear. Title: trump administration preserves federal funding for US DAC and hydrogen hubs. The U.S. Department of Energy has decided to preserve or modify roughly 2,000 carbon removal or climate-oriented projects including five major hydrogen hubs and the two largest carbon dioxide direct air capture hubs. Colorado legislature sends 'advanced transmission technology' bill to governor. The Colorado legislature passed legislation requiring regulated utilities to consider using "advanced transmission technologies" in the 10-year transmission plans the utilities issue every two years.
Air Force selects Radiant to deliver microreactors to Buckley Space Force Base. April 22, 2026 7:24 AM Gift Article Kaleidos reactors will supply resilient power to support critical national security and intelligence missions EL SEGUNDO, CA / ACCESS Newswire / April 22, 2026 / The Department of the Air Force, in conjunction with the Defense Innovation Unit, today announced that it has selected Radiant to develop and operate a nuclear microreactor proposed for Buckley Space Force Base in Aurora, Colorado, in fulfillment of the Advanced Nuclear Power for Installations (ANPI) initiative. Radiant's Kaleidos reactors aims to be America's first commercially developed microreactor to support a military facility, ushering in the nation's renewed commitment to nuclear power. The first Kaleidos reactors will be delivered by 2028. "Together with our incredible government partners, Radiant is making the nuclear renaissance a reality," said Mike Starrett, Chief Revenue Officer at Radiant. "The American energy industry needs to make progress now, not in 5 or 10 years. With a full-power reactor already under assembly, Radiant will deliver." Radiant's Kaleidos microreactor will provide sustained, uninterrupted energy to support critical infrastructure for the Department of the Air Force. "The future of air and space dominance is powered by resilient energy," said Honorable Michael Borders, Assistant Secretary of the Air Force for Energy, Installations, and Environment. "By integrating advanced nuclear technology, we are not just keeping the lights on; we are guaranteeing that our most critical national security missions will never be held at risk by a power outage. This is a pivotal moment for the Department of the Air Force." With a resilient, always-on power capability measured in years, not days, Kaleidos will provide the operational continuity and mission readiness that critical installations demand. "This places Buckley Space Force Base at the forefront of the Department's next-generation energy technology initiative," said Col. Eamon Murray, Space Base Delta 2 commander, Buckley Space Force Base, Colo. "A secure and reliable power source will enable Buckley's warfighters from all 6 services and allied nations to support the Joint Force in all situations, and we are proud to lead the charge to advance our warfighters' technological superiority. The success of this endeavor depends on strong community trust we've built through proactive engagement and communication, and we're excited to continue that engagement and transparency throughout this process." The ANPI program seeks to have at least one advanced nuclear reactor operating on at least one DAF installation by 2030 or sooner. Next steps include siting and environmental analyses as part of the National Environmental Policy Act process. Radiant is the only nuclear energy company conducting a full power, commercial scale, multi-megawatt powered test at the Idaho National Laboratory's DOME test facility in 2026. Radiant will announce a series of public meetings to share information about the Kaleidos microreactor project. Learn more about Radiant at www.radiantnuclear.com. About Radiant Radiant is building the world's first mass-produced nuclear generators that can go anywhere they're needed, whenever they're needed, and without constant refueling. The company's first generator, Kaleidos, is a 1 MWe failsafe nuclear microreactor. Founded in 2020, Radiant plans to test its first reactor in 2026, with initial customer deployments beginning in 2028. Radiant's mission is to mass produce the most economical and reliable portable reactors in the world. Media Contact