Computational Nuclear Engineer

About Thea Energy:

Thea Energy is leveraging recent breakthroughs in stellarator physics and engineering to create a faster and simpler approach to commercializing fusion energy. The company is reinventing the stellarator using computer-controlled arrays of planar coils thereby replacing the intricate, complex modular magnets required in all other stellarator architectures. Thea Energy is on a mission to create a limitless source of zero emission energy for a sustainable future.

Position Overview:

We are seeking a highly motivated Computational Nuclear Engineer to join our team, focusing on neutronics and multiphysics simulations for stellarator fusion systems. The ideal candidate will possess a strong background in computational transport methods, with a particular emphasis on multiphysics reactor design, dose rate calculations, and radiation shielding optimization. You will work with minimal supervision, contributing to cutting-edge research and development to ensure the safety and performance of Thea Energy’s stellarator systems.

Key Responsibility Areas:

• Develop and implement advanced workflows for high-fidelity neutronics and related multiphysics simulations in complex 3D stellarator geometries.

• Conduct simulations of fusion blanket performance, including tritium breeding ratios (TBR), energy deposition, material activation, radiation shielding, and more.

• Collaborate with cross-disciplinary teams to perform multiphysics coupling (e.g., neutronics to thermal-hydraulics or structural analysis) to refine reactor designs.

• Perform dose rate calculations and design optimized shielding solutions for personnel and sensitive equipment.

• Prepare technical reports, presentations, and publications based on simulation results and optimization findings.

Ideal Experience & Skillsets:

• PhD in Nuclear Engineering, Computational Physics, Applied Physics, or a related field with 2+ years of experience; or a Master’s degree in a relevant field with 4+ years of experience.

• Strong knowledge of Monte Carlo radiation transport codes (e.g., OpenMC, MCNP, Serpent).

• Proficiency in programming languages commonly used in scientific computing, specifically Python and C++.

• Proficiency in modern scientific software development best-practices (e.g. git, GitHub, CI)

• Experience in multiphysics coupling frameworks (e.g., MOOSE, Cardinal, NekRS).

• Excellent analytical, problem-solving, and communication skills.

Preferred Skills:

• Experience with nuclear data processing and libraries (e.g., NJOY). Experience with deterministic neutron transport solvers (e.g. Atilla, OpenSN)

• Familiarity with High-Performance Computing (HPC) environments and parallel programming (MPI/OpenMP).

• Background in applying machine learning techniques to optimize nuclear simulation results or data handling.

• Understanding of fusion-specific nuclear challenges, such as first-wall material damage and tritium fuel cycle management.

Personal Attributes:

• Ability to work independently and manage projects with minimal supervision in a startup environment.

• Strong attention to detail and a passion for advancing the field of fusion energy research.

• Willingness to collaborate with a diverse team of scientists and engineers within the company and externally.

• Persistent optimism and a willingness to take on tough challenges.

• Excited to think creatively about solutions to difficult problems and not relying solely on what has been done before.

Company Benefits:

• Salary range: $120,000-$180,000

• Comprehensive health benefits (e.g. medical/dental/vision)

• Employee equity stock options

• 20 days PTO