Senior Technical Program Manager, Security & IT

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, fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. 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 leverages modern software engineering to rapidly deliver safe, factory-built microreactors that use existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor at the Idaho National Laboratory this summer, with initial customer deliveries beginning in 2028.

About the Role

Radiant is seeking a talented Technical Program Manager, IT & Security, to own visibility and delivery across our IT and security program portfolio. You will track eight concurrent programs spanning three states: a reactor program at Idaho National Laboratory; a fuel facility and manufacturing plant in Tennessee; warehouse and office buildouts in Los Angeles; a site decommissioning; and a CMMC and NIST SP 800-171 compliance program running across all of it.

We have strong technical leaders on each effort. What we don't have is one person who can see the whole portfolio at once, keep it visible, and ensure teams meet commitments. In this role, you won't write the SSP or design the network. You'll make sure the people doing that work are aligned, unblocked, and delivering against a schedule everyone can see. You'll represent IT leadership in meetings we can't attend, and you'll be the reason nothing quietly slips.

Responsibilities & Duties

* Build the system of record for how IT and security programs are tracked at Radiant, standing up the tooling, cadence, and reporting that today lives across spreadsheets, inboxes, and people's heads.

* Own the operating cadence, including recurring status meetings within IT and security and cross-functional reviews with facilities, construction, engineering, and external partners; set agendas, drive to decisions, capture actions, and follow up.

* Maintain integrated schedules, dependencies, risks, and milestones across concurrent programs; know what's on track, what's at risk, and what needs escalation before anyone asks.

* Keep IT scope sequenced with construction, partnering with the facilities project manager to ensure structured cabling, MDF/IDF, low-voltage, access control, cameras, wireless, and carrier circuits are planned into general contractor milestones rather than retrofitted after drywall.

* Support the CMMC and NIST SP 800-171 compliance program alongside executives, tracking milestone plans, POA&M status, remediation coordination, evidence collection, and assessor coordination while technical control decisions remain with the security team.

* Produce technical and network diagrams, architecture documentation, project charters, status reporting, and executive summaries.

* Escalate slipping commitments and unresolved blockers to the VP of IT and VP of Cybersecurity early enough to act on them.

Required Qualifications & Skills

* 6+ years in technical program or project management, including infrastructure and security programs.

* Experience delivering IT infrastructure into new construction or facility buildouts, manufacturing, industrial, healthcare, or multi-site commercial.

* Ability to read a construction schedule, work with a facilities PM and general contractor, and know when the window for IT work opens and closes.

* Hands-on experience administering and structuring work in Atlassian tooling, building Jira projects, workflows, dashboards, and Confluence spaces that teams actually adopted.

* Ability to hold your own in an architecture review: read and produce network diagrams, understand infrastructure and security concepts, and ask the right questions of engineers without needing translation.

* Experience in a regulated environment, nuclear, defense, aerospace, life sciences, or similar, including work under compliance frameworks.

* Track record of driving accountability without direct authority, through influence, clear artifacts, and disciplined follow-through.

* Strong written communication, documentation that engineers respect and executives can act on.

Desired Qualifications & Skills

* Familiarity with CMMC, NIST SP 800-171, or FedRAMP.

* Experience in DOE, a national laboratory, or ITAR-controlled environments.

* Exposure to OT and IT convergence in manufacturing or plant settings.

* Site decommissioning or IT asset disposition experience.

* PMP or equivalent formal project management training.

Additional Requirements

* Must be willing to work extended hours and weekends as necessary to accomplish our mission.

* Must work 100% onsite at Radiant's El Segundo HQ.

* Travel up to 15%, heavier during site activation windows.

• 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.

• 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 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: [email protected].
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.