Senior Material Planner

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. About the Role Radiant is seeking a proactive Senior Material Planner to own material planning across the full lifecycle of our micro nuclear reactors. This role partners with Engineering to translate reactor designs into a company-wide planning bill of materials and works alongside the Mission Planning team to stand up Materials Resource Planning (MRP) within our new Enterprise Resource Planning (ERP) system. You will manage key part attributes — lead times, order quantities, and safety stock — to keep material plans accurate across the build. You will coordinate closely with Production to ensure make/buy decisions in MRP reflect the current build sequence. As Radiant's first Material Planner, you will build this function from the ground up and set the standard for how material planning operates at the company. Responsibilities & Duties: Planning Bill of Materials: Partner with Engineering to translate reactor design into a company-wide planning bill of materials. MRP Standup: Work with the Mission Planning team to configure and launch Materials Resource Planning within our new ERP system. Part Attribute Management: Own and maintain part attributes — lead times, order quantities, safety stock levels — to ensure accurate, actionable material plans. Make/Buy Alignment: Coordinate with Production to keep make/buy decisions in MRP current with the production plan. Shortage Reporting: Produce weekly Clear to Build reports identifying company-wide material shortages for Production. Design Release Reporting: Produce weekly Design Release Needs reports, flagging designs required to meet procurement lead times. Deliverables: Company-wide planning bill of materials Populated Materials Resource Plan Maintained part attributes across the product line Weekly Clear to Build reports showing production shortages Weekly Design Release Needs reports based on procurement lead times Required Qualifications & Skills: 3 – 10 years of relevant experience in material planning, supply chain management, or operations, preferably within manufacturing or technology sectors. ERP/MRP system experience Strong analytical and organizational skills with an ability to manage complex, evolving bills of materials. Excellent cross-functional communication skills — this role sits at the intersection of Engineering, Mission Planning, and Production. Comfort operating with ambiguity and building processes from scratch. Desired Qualifications & Skills: Experience working in a start-up, or other rapidly evolving industry is preferred Additional Requirements: Must be willing to work extended hours and weekends as necessary to accomplish our mission. Must work 100% onsite at El Segundo HQ. Benefits and Perks 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. …

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