Senior Technical Program Manager, Security & IT

About Radiant

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…