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.

Job Summary:

We are seeking a T&E (Travel & Expense) Specialist to manage the processing and review of employee T&E activity and credit card charges for our nuclear energy company. You will help ensure expenses are accurate, policy-compliant, and properly recorded, while providing responsive support to employees who travel to project sites, vendor facilities, and regulatory meetings.

Key Responsibilities:

• Review and process employee expense reports for accuracy, policy compliance, and proper documentation

• Process corporate card transactions and reconcile card statements to the general ledger

• Verify correct coding of expenses to cost centers, projects, and accounts, including project-specific cost tracking

• Ensure compliance with company travel policy and applicable government contract cost rules (e.g., per diem, allowable costs), where relevant

• Respond to employee questions and resolve expense report issues in a timely, professional manner

• Follow up on missing receipts, overdue reports, and unreconciled items

• Prepare periodic reports on travel spend, policy exceptions, and outstanding balances

• Support month-end close activities related to T&E accruals

• Identify process improvements and help maintain T&E policy documentation

Required Qualifications:

• Associate's or Bachelor's degree in Accounting, Finance, Business Administration, or a related field (or equivalent experience)

• 3+ years of experience in travel and expense processing, accounts payable, or a similar finance role

• Experience with expense management platforms (e.g., Ramp, Concur, Expensify, Workday, Coupa)

• Strong working knowledge of Microsoft Excel

• Attention to detail and strong organizational skills

• Clear written and verbal communication skills

• Ability to handle confidential financial information with discretion

Preferred Qualifications:

• Experience supporting a regulated industry such as nuclear, energy, aerospace, or defense

• Familiarity with government contract cost principles (e.g., FAR, DCAA requirements) or Department of Energy contracting

• Experience with corporate card programs and reconciliation

• Familiarity with ERP systems (e.g., SAP, Oracle, NetSuite)

• Experience with international travel, foreign per diem rates, and multi-currency expenses

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.

• 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: recruiting@radiantnuclear.com.

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.