About the role

Nuclear Analysis Engineer

Aalo is seeking a Nuclear Analysis Engineer to support the design, analysis, licensing, testing, deployment, and operation of Aalo's advanced reactor systems. Aalo is developing modular sodium-cooled reactor technology intended for scalable manufacturing and deployment. This role will contribute directly to reactor core design, safety analysis, and the technical basis needed to support design decisions, testing, and regulatory engagement.

As a Nuclear Analysis Engineer, you will perform a broad range of reactor physics and neutronics analyses using modern modeling and simulation tools. Your work will help guide core design and optimization, evaluate reactor performance and safety behavior, and generate high-quality technical documentation to support internal reviews and external submittals. This role is highly collaborative and interfaces closely with teams across fuel design, thermal-hydraulics, safety analysis, mechanical design, manufacturing, testing, and licensing.

Aalo operates in a fast-paced engineering environment. Engineers are expected to take ownership of difficult technical problems, develop practical and rigorous analytical methods, communicate clearly, and help drive designs from early concepts through detailed analysis, fabrication, testing, and operation.

Responsibilities

Specific responsibilities may include:

• Perform neutronics and reactor physics analyses in support of the design, evaluation, and optimization of advanced reactor cores.
• Develop high-fidelity three-dimensional reactor models using Monte Carlo transport tools such as Serpent, MCNP, OpenMC, and SCALE.
• Perform deterministic reactor physics calculations and develop reduced-order models, as appropriate, to support design iteration, scoping studies, and coupled analyses.
• Evaluate core criticality, neutron flux and power distributions, power peaking, control rod worth, shutdown margin, excess reactivity, and other key nuclear design parameters.
• Perform fuel depletion and fuel cycle analyses, including evaluation of fuel burnup, isotopic evolution, fission product poisoning, reactivity swing, activation, decay heat, and fuel management strategies.
• Support multiphysics analysis by coupling neutronics models with thermal-hydraulics, fuel performance, and thermo-mechanical analysis tools.
• Evaluate reactivity coefficients and feedback mechanisms, including fuel temperature (Doppler), moderator temperature, coolant temperature and density effects, voiding, and other temperature-dependent material effects.
• Calculate reactor kinetics parameters, including delayed neutron fraction, neutron generation time, and related quantities needed for reactor dynamics and safety analysis.
• Perform activation, radiation source term, and shielding analyses as needed to support reactor design, operations, maintenance, and safety evaluations.
• Prepare clear, well-organized technical reports, presentations, and supporting documentation for design reviews, safety analyses, and licensing activities.
• Communicate methods, assumptions, uncertainties, limitations, and design implications effectively to both technical and cross-functional stakeholders.

Technical Areas

Candidates may contribute across several of the following technical areas:

• Monte Carlo neutron transport
• Deterministic neutron transport and diffusion methods
• Criticality analysis
• Fuel depletion and fuel cycle analysis
• Radioactive decay, activation, and source term characterization
• Sensitivity analysis and uncertainty quantification
• Multiphysics coupling
• Neutron instrumentation and detector response
• Verification and validation of neutronics analysis software

Minimum Qualifications

• Bachelor's degree in Nuclear Engineering, Physics, Mechanical Engineering, or a closely related technical discipline
• 5+ years of experience performing reactor physics or neutronics analyses for nuclear reactor systems
• Strong grounding in neutron transport, reactor physics, criticality, and nuclear engineering fundamentals
• Experience with continuous-energy Monte Carlo methods and codes
• Experience with deterministic reactor physics methods or tools, including diffusion theory, discrete ordinates, nodal methods, or fast reactor analysis methods
• Proficiency in Python for engineering analysis, automation, scientific computing, or data processing
• Strong written and verbal communication skills

Preferred Qualifications

• Master's degree or Ph.D. in Nuclear Engineering or a related field
• 10+ years of experience in reactor physics, core design, or nuclear analysis
• Experience with one or more production neutronics tools such as Serpent, MCNP, OpenMC, SCALE/KENO, Griffin, or DIF3D
• Experience with deterministic reactor physics tools or methods, including diffusion, discrete ordinates, nodal methods, or fast reactor analysis approaches
• Experience with advanced thermal-spectrum reactor design
• Experience designing or analyzing sodium-cooled reactor systems
• Experience using AI tools to improve the efficiency and effectiveness of engineering workflows
• Experience working under NQA-1-compliant software quality assurance programs and procedures, including software qualification and commercial-grade dedication

Requirements:

• Based in the United States
• Willing to work on-site in Austin, TX

What It Takes to Succeed at Aalo

We're building technology that will help reshape the future of energy. The pace is fast, the problems are difficult, and the expectations are high. Successful team members consistently demonstrate:

Extreme Ownership - You take responsibility for outcomes, not just tasks. You proactively identify problems, drive solutions, and follow through.

A Passion for Solving Hard Problems - You are energized by challenges that others avoid and enjoy finding practical solutions to complex technical issues.

A Sense of Urgency - You move quickly, make thoughtful decisions, and maintain momentum while balancing quality and execution.

What We Offer

• Competitive salary based on technical level
• Health, Dental, and Vision Insurance
• Paid Time Off
• Corporate Gym Membership

Candidates only. No recruiters or agencies, please.