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.

Radiant is seeking a Technical Program Manager, IT & Security, to own visibility and delivery across our IT and security portfolio: eight concurrent programs across three states, including 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 spanning all of it.

We have strong technical leaders on each effort. This role exists to see the whole portfolio, keep it visible, and hold teams to their commitments. You won't write the SSP or design the network; you'll keep the people who do aligned, unblocked, and delivering against a schedule everyone can see. You'll represent IT leadership in meetings we can't attend, and be the reason nothing quietly slips.

• Build the system of record for tracking IT and security programs, including the tooling, cadence, and reporting.

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

• Maintain integrated schedules, dependencies, risks, and milestones across all eight concurrent programs; know what is on track, what is at risk, and what needs escalation before anyone asks.

• Produce network and architecture diagrams, 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, and represent IT leadership in meetings they cannot attend

• Support the CMMC and NIST SP 800-171 program alongside executives: milestone plans, POA&M status, remediation coordination, evidence collection, assessor coordination; technical control decisions stay with the security team.

• First 90 days: inventory all eight programs and their owners, stand up the Jira and Confluence structure, publish the first integrated portfolio schedule, and establish the recurring reporting cadence

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

• Delivered IT infrastructure into new construction or facility buildouts: manufacturing, industrial, healthcare, or multi-site commercial

• Hands-on Atlassian administration-built Jira projects, workflows, dashboards, and Confluence spaces that teams actually adopted, not just filed tickets in someone else's instance

• Can hold their own in an architecture review; reads and produces network diagrams; understands infrastructure and security concepts; asks the right questions of engineers without needing translation.

• Keep IT scope sequenced with construction alongside the facilities PM and general contractor so structured cabling, MDF/IDF, low voltage, access control, cameras, wireless, and carrier circuits are planned into GC milestones.

• Regulated environment experience (nuclear, defense, aerospace, life sciences, or similar) including work under compliance frameworks

• Strong written communication skills, producing documentation that is respected by engineers and actionable for executives.

• Foster a culture of influence, effective stakeholder management, and teamwork.

• Breadth of IT experience

• Delivered IT infrastructure into new construction or facility buildouts: manufacturing, industrial, healthcare, or multi-site commercial

• Familiarity with CMMC, NIST SP 800-171, or FedRAMP

• DOE, national laboratory, or ITAR-controlled environment experience

• 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

• Multi-site or multi-state portfolio experience with regular travel

• 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.