Neutronics Engineer

About the role

This role owns the core neutronics analysis required for licensing and operational safety of the Alpha stellarator, driving the integration of simulation workflows into a fast-moving engineering pipeline. You will shape the architecture of the world's first commercial fusion power plant by making system-level decisions that determine how this first-of-a-kind energy technology is designed, integrated, and deployed at scale. The position requires solving some of the most complex engineering challenges by working across tightly coupled disciplines, including plasma physics, magnets, cryogenics, manufacturing, and controls, to resolve critical trade-offs and turn cutting-edge science into a functioning product. You will design real hardware alongside a pragmatic, fast-moving team from all over the world, combining advanced simulation and systems thinking with a strong execution mindset to accelerate the path to commercial fusion energy. In this capacity, you will carry out reproducible neutronics simulations and automate neutronics simulation workflows, producing shutdown dose rate maps, analyzing magnet heating, and performing tritium breeding, DPA, and activation using both CSG and CAD-based neutronics models. Your impact will be felt as you contribute directly to an integrated design effort alongside machine learning experts, software engineers, fusion scientists, and fusion engineers, making a tangible impact on the future of clean energy.

Key facts

What you'll do

• Perform neutronics analysis using OpenMC and DAGMC for a range of neutron and photon responses important for stellarator optimization and design.
• Contribute to the integration of neutronics analysis into automated pipelines, including programming in Python (essential skill), using version control (Git/Graphite) within a Docker environment, Programming in C++ is considered a benefit.
• Perform verification and validation by comparing simulation results obtained with OpenMC to other codes and experimental data.
• Construct simulation ready CAD with CadQuery and CSG geometries of the stellarator and surrounding facility.
• Develop and maintain in-house neutronics workflows while ensuring reproducibility, accuracy, and alignment with regulatory requirements for licensing.
• Analyze shutdown dose rate maps and assess radiation shielding performance for both workers and the public in compliance with strict safety standards.
• Evaluate tritium breeding ratios and activation levels to inform material selection and component lifetime strategies for the Alpha device.
• Collaborate with magnet and cryogenic teams to model heat loads and assess magnetic shielding integrity under various operational scenarios.
• Contribute to open-source codes used for nuclear data processing, CAD conversion, meshing, and particle transport simulations to strengthen the broader fusion community.
• Support the integration of machine learning techniques to optimize simulation workflows, reduce turnaround time, and improve predictive fidelity.
• Work within Dockerized computational environments and HPC/cloud infrastructure to execute large-scale simulations efficiently and securely.
• Document methodologies, assumptions, and results clearly to enable peer review, auditing, and seamless handover between team members.

Requirements

• A PhD or Master's degree in nuclear physics, nuclear engineering, or equivalent experience.
• Experience in processing nuclear data for transport simulations and uncertainty quantification.
• Experience with the main codes that we use (OpenMC, DAGMC, CadQuery, Gmsh) for neutronics analysis.
• Experience designing neutron and gamma shielding for high-energy density environments typical of fusion systems.
• An experienced Python programmer using software development tools such as Git to build robust, version-controlled workflows.
• A strong understanding of computational methods for radiation transport, dose deposition, and activation analysis.
• Familiarity with CSG and CAD-based modeling approaches for complex geometry representation in neutronics simulations.
• Proven ability to work within regulated environments where safety, reliability, and traceability are paramount.

Nice to have

• Experience with computation in cloud or HPC environments involving numerical simulations (desirable).

Practical notes

This role sits at L2/L3 of our framework, please inquire during the recruitment process for further information.

Interview Process

• Recruiter Interview (30-60 min)
• Technical Screening (30 min)
• Technical Panel (3x60 min)
• CEO call (30 min)