<div><p>Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt failsafe microreactor that can be transported anywhere power is needed and run for up to five years without the need to refuel. Portable nuclear power with rapid deploy capability can replace similar-sized diesel generators, and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development utilizes modern software engineering to rapidly achieve safe, factory-built microreactors that leverage existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor next year at the Idaho National Laboratory, with initial customer deliveries beginning in 2028.</p></div><div><strong>Software Engineering Internship<br></strong><br>Radiant is seeking a motivated <strong>Software Engineering Intern</strong> with a strong computer science foundation to join our team. As an intern, you will work alongside mechanical, electrical, and nuclear engineers to assist in developing software tools that support simulation and analysis for reactor design, development, and safety analysis. This is an excellent opportunity to gain hands-on software development experience in a highly interdisciplinary environment.<br><br><em>Please note: we plan to begin interviewing for Summer 2026 internships in November/December. </em><br><br><strong>Responsibilities and Duties:</strong></div><ul><li>Assist in creating tooling to support a variety of simulation software packages.</li><li>Contribute to internal software products that support simulation and analysis of simulation results.</li></ul><div><strong>Required Qualifications and Skills:</strong></div><ul><li>Currently pursuing a degree in computer science, physics, or a related technical discipline.</li><li>Familiarity with Python, C++, C#, or similar object-oriented programming languages.</li><li>Basic knowledge of software development practices and version control tools such as Git.</li></ul><div><strong>Desired Qualifications and Skills:</strong></div><ul><li>Strong self-motivation and the ability to collaborate effectively in a team environment.</li><li>Interest in contributing to simulation tools or working on software testing.</li><li>Familiarity with distributed software development and common design patterns is a plus.</li><li>A passion for physics, hardware, or electrical engineering is highly encouraged.</li></ul><div><strong>Additional Information:</strong></div><ul><li>This internship will require working onsite at our El Segundo HQ.</li><li>You may be asked to work extended hours or weekends occasionally to support project goals.</li></ul><div><p><strong>Total Compensation and Benefits</strong></p><p>Radiant's new hire compensation package includes base salary, substantial equity grants, and comprehensive benefits. Total compensation and level are determined through a holistic evaluation of your interview performance, experience, education, and qualifications. </p><p><strong>Benefits and Perks for Eligible Employees:</strong></p><ul><li>Stock: Substantial incentive stock plan for all full-time employees.</li><li>Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.</li><li>One Medical: Sponsored memberships for employees and their dependents.</li><li>Vision: 100% top tier plan coverage + 50% for dependents.</li><li>Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.</li><li>Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.</li><li>8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.</li><li>Daily catered lunch. Free snacks and drinks.</li><li>Flexible PTO policy. Remote workday allocation.</li><li>Company and team-bonding events, happy hours and in-person camaraderie.</li><li>Beautiful El Segundo headquarters close to the Pacific Ocean.</li></ul><p><em>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.</em></p><p><em>Unfortunately, we are unable to provide visa sponsorship at this time. </em></p><p><em>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.<br></em></p></div>

<p>Radiant is a clean energy startup building a nuclear microreactor. A climate-friendly alternative to diesel generators, Radiant's Kaleidos 1MW microreactor will be the world's first portable, zero-emissions power source that works anywhere. We plan to test our development reactor by 2026 and if successful, it will be the first new commercial reactor design to achieve a fueled test in over 50 years. Our microreactor can bring power to remote parts of the world and provide backup power for life-saving applications in hospitals or disaster-relief scenarios.&nbsp;</p>

Summer 2026 Internship - Software Engineering

<div><p>Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt failsafe microreactor that can be transported anywhere power is needed and run for up to five years without the need to refuel. Portable nuclear power with rapid deploy capability can replace similar-sized diesel generators, and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development utilizes modern software engineering to rapidly achieve safe, factory-built microreactors that leverage existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor next year at the Idaho National Laboratory, with initial customer deliveries beginning in 2028.</p></div><div><strong>Software Engineering Internship<br></strong><br>Radiant is seeking a motivated&nbsp;<strong>Software Engineering Intern</strong>&nbsp;with a strong computer science foundation to join our team. As an intern, you will work alongside mechanical, electrical, and nuclear engineers to assist in developing software tools that support simulation and analysis for reactor design, development, and safety analysis. This is an excellent opportunity to gain hands-on software development experience in a highly interdisciplinary environment.<br><br><em>Please note: we plan to begin interviewing for Summer 2026 internships in November/December.&nbsp;</em><br><br><strong>Responsibilities and Duties:</strong></div><ul><li>Assist in creating tooling to support a variety of simulation software packages.</li><li>Contribute to internal software products that support simulation and analysis of simulation results.</li></ul><div><strong>Required Qualifications and Skills:</strong></div><ul><li>Currently pursuing a degree in computer science, physics, or a related technical discipline.</li><li>Familiarity with Python, C++, C#, or similar object-oriented programming languages.</li><li>Basic knowledge of software development practices and version control tools such as Git.</li></ul><div><strong>Desired Qualifications and Skills:</strong></div><ul><li>Strong self-motivation and the ability to collaborate effectively in a team environment.</li><li>Interest in contributing to simulation tools or working on software testing.</li><li>Familiarity with distributed software development and common design patterns is a plus.</li><li>A passion for physics, hardware, or electrical engineering is highly encouraged.</li></ul><div><strong>Additional Information:</strong></div><ul><li>This internship will require working onsite at our El Segundo HQ.</li><li>You may be asked to work extended hours or weekends occasionally to support project goals.</li></ul><div><p><strong>Total Compensation and Benefits</strong></p><p>Radiant's new hire compensation package includes base salary, substantial equity grants, and comprehensive benefits. Total compensation and level are determined through a holistic evaluation of your interview performance, experience, education, and qualifications.&nbsp;</p><p><strong>Benefits and Perks for Eligible Employees:</strong></p><ul><li>Stock: Substantial incentive stock plan for all full-time employees.</li><li>Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.</li><li>One Medical: Sponsored memberships for employees and their dependents.</li><li>Vision: 100% top tier plan coverage + 50% for dependents.</li><li>Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.</li><li>Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.</li><li>8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.</li><li>Daily catered lunch. Free snacks and drinks.</li><li>Flexible PTO policy. Remote workday allocation.</li><li>Company and team-bonding events, happy hours and in-person camaraderie.</li><li>Beautiful El Segundo headquarters close to the Pacific Ocean.</li></ul><p><em>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.</em></p><p><em>Unfortunately, we are unable to provide visa sponsorship at this time. </em></p><p><em>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.<br></em></p></div>

Summer 2026 Internship - Software Engineering

About the Job

About the Company

Radiant

Similar Jobs

Software Engineering Intern (Summer 2026)

Software Engineering Intern (Summer 2026)

Systems Engineering Intern (Summer 2026)

Systems Engineering Intern (Summer 2026)

Software Engineer Intern - Summer 2026

Software Engineer Intern - Summer 2026

IT Software Developer Intern

IT Software Developer Intern

IT Software Developer Intern

IT Software Developer Intern

RMCC Software Engineering Intern

RMCC Software Engineering Intern

RF Science Intern (Summer 2026)

RF Science Intern (Summer 2026)

Software Engineering Intern - Automation

Software Engineering Intern - Automation

Software Engineer, ML Infrastructure - Winter Internship 2025/2026

Software Engineer, ML Infrastructure - Winter Internship 2025/2026

Systems Engineering Internships

Systems Engineering InternshipsNew