Neutronics Jobs in Oak Ridge, TN (NOW HIRING)

Join us in our mission to commercialize fusion energy
About Type One Energy
Type One Energy Group is mission-driven to provide sustainable, affordable fusion power to the world. Established in 2019 and venture-backed in 2023, the company is led by a team of globally recognized fusion scientists with a strong track record of building state-of-the-art stellarator fusion machines, together with veteran business leaders experienced in scaling companies and commercializing energy technologies.
If you are searching for the best new ideas and share our vision, join us as a Multiphysics Modeling Engineer. This is what you need to know:
Location: Knoxville, TN or Culham (UK)
Salary: Highly Competitive Plus Benefits
Contract: Permanent, full time
Reporting to: Senior Director of Nuclear and Fuel Cycle
Your role in the mission:
Type One Energy is seeking a highly experienced and technically strong Multiphysics Modeling Engineer to drive the development, integration, and application of advanced multiphysics simulation capabilities for fusion energy systems.
This role is responsible for establishing and executing the company's strategy for MOOSE-based simulation across plasma-facing components, structural systems, blankets, and tritium-relevant subsystems. The role will play a critical part in enabling high-fidelity, tightly coupled simulations to inform the design of the Infinity Two stellarator power plant and future commercial systems.
The successful candidate will help establish multiphysics capabilities, develop simulation workflows that integrate radiation, thermal, structural, materials, and tritium physics, and ensure that modeling outputs are rigorously validated and directly tied to engineering decision-making.
In addition, the Multiphysics Modeling Engineer will help define the architecture for integrated simulation environments, including coupling MOOSE with external tools (e.g., neutronics, plasma codes, CAD/meshing pipelines), and will contribute to the development closely coupled models for near-term experimental activities.

• Serve as a technical authority for multiphysics simulation using the MOOSE framework across key fusion subsystems (e.g., plasma-facing components, blankets, tritium plant, etc).
• Develop and execute a comprehensive roadmap for MOOSE-based modelling, including physics capability development, validation strategy, and integration with the broader design toolchain.
• Lead the development of tightly coupled multiphysics models (thermal, structural, tritium transport, radiation, electromagnetics, and materials behaviour) to support fusion energy system design.
• Establish best practices for software quality assurance, model development, verification & validation (V&V), configuration control, and reproducibility.
• Collaborate with cross-functional teams (plasma physics, neutronics, mechanical, thermofluid, materials, systems engineering) to ensure consistent and integrated modelling approaches.
• Develop workflows to couple MOOSE with external tools (e.g., radiation transport, plasma, structural, CFD tools) for end-to-end simulation capability.
• Apply simulation results to evaluate performance, lifetime, and failure modes of critical components under fusion-relevant conditions.
• Support design trade studies and optimization using high-fidelity multiphysics simulations.
• Integrate experimental data and R&D results into models to improve predictive capability and reduce uncertainty.
• Contribute to the development of closely coupled models for near-term experimental activities.
• Prepare technical reports, presentations, and publications to communicate modelling results and influence design decisions.
• Engage with external collaborators (national labs, universities, industry partners) to advance state-of-the-art multiphysics modelling approaches.
• Be accountable for the quality, accuracy, and applicability of simulation tools and results.
• Provide transparent and realistic assessments of timelines, risks, resource requirements, and data needs.

What you'll need:

• PhD or equivalent experience in Nuclear Engineering, Mechanical Engineering, Physics, Materials Science, Computer Science, or a related field.
• Proven track record in multiphysics simulation and computational modeling, ideally in fusion, advanced fission, or high-performance energy systems.
• Deep experience with the MOOSE framework and its ecosystem.
• Strong understanding of coupled physics relevant to fusion systems, including: Heat transfer and thermal hydraulics, Structural mechanics and material behavior, Radiation effects and materials degradation, Tritium/hydrogen transport, and Electromagnetic effects (desirable).
• Familiarity with complementary tools such as OpenMC, MCNP, ANSYS, COMSOL, OpenFOAM, or plasma simulation codes.
• Experience developing or extending scientific software in C++ and/or Python.
• Demonstrated experience leading technical programs and managing complex, multidisciplinary modeling efforts.
• Experience with verification and validation methodologies and uncertainty quantification.
• Familiarity with HPC environments and parallel computing.
• Experience integrating multiple simulation tools and managing complex workflows.
• Strong analytical, problem-solving, and systems-thinking skills.
• Excellent communication skills, with the ability to translate advanced simulation results into engineering insight.

We offer:
In addition to a basic salary and yearly bonus, you will also get...

• A hybrid work policy
• Stock options
• Relocation assistance
• Insurance plans
• Retirement options
• And many more great voluntary benefits

Type One Energy applies proven advanced manufacturing methods, modern computational physics and high-field superconducting magnets to develop its optimized stellarator fusion energy system. Our FusionDirect development program pursues the lowest-risk, shortest-schedule path to a fusion power plant over the coming decade, using a partner-intensive and capital-efficient strategy.
Type One Energy is committed to community engagement in the development and deployment of its clean energy technology. For more information, visit www.typeoneenergy.com or follow us on LinkedIn.
Equal Opportunity Statement
Type One Energy is an equal opportunity employer. We value diversity, searching for the best new ideas and remaining open to unique perspectives. Therefore, all qualified applicants will receive consideration for employment independent of race, color, religion, sex, sexual orientation, gender identity, national origin, disability or veteran status, age, or any other characteristics protected by applicable federal, state, or local laws. All qualified individuals are encouraged to apply.