Cost Accounting Manager

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.

Responsibilities & Duties:

• Lead and oversee all cost and inventory accounting functions within the accounting team, reporting directly to the Director of Accounting.

• Manage all aspects of manufacturing cost accounting, including costing projects, month-end close, cost maintenance, labor and overhead absorption, inventory and fixed assets management, and freight/duty tracking.

• Develop strong cross-functional relationships with Operations and Supply Chain teams to enhance understanding of processes, costs, and revenue drivers.

• Analyze cost variances, production volumes, and material usage trends, implementing timely adjustments in collaboration with key stakeholders.

• Take ownership of cost accounting functions, establish best practices, and drive process improvements, with a focus on change management.

• Identify and implement operational efficiencies to improve labor and overhead burden costs, driving business profitability.

• Ensure ERP data accuracy through regular analysis, internal audits, and coordination with inventory control and production teams. Lead ERP process enhancements to support evolving business needs.

• Partner with FP&A to identify cost drivers, develop financial models, and ensure accurate Bill of Materials (BOM) cost calculations. Perform key variance analyses, including margin analysis, purchase price variances, and cost revaluations.

• Prepare accounting schedules and reports for internal and external stakeholders.

• Support audit processes as needed.

Required Qualifications & Skills:

• Bachelor’s degree in Accounting, Finance, or a related field.

• 7+ years of cost accounting experience, preferably in a manufacturing and/or R&D environment.

• Strong hands-on expertise in managerial and financial accounting, with the ability to understand production environments and related financial processes.

• Deep knowledge of supply chain, inventory flow, operations, and manufacturing principles.

• Proven ability to analyze transactional data in an ERP system and communicate key insights to leadership.

• Strong business acumen with a solid understanding of financial, distribution, and manufacturing systems.

• Highly organized, dependable, and professional, with the ability to multitask, prioritize, and meet deadlines.

• Ability to work independently and collaborate cross-functionally to achieve organizational goals.

• Willingness to work overtime as needed.

• Excellent written and verbal communication skills, with strong attention to detail and accuracy.

• Preferred qualifications: CPA, MBA, or CMA certification, along with supervisory and financial reporting experience.

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.

• 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.