---
title: 'Computational Nuclear Engineer at Thea Energy'
canonical: 'https://feeny.ai/job/computational-nuclear-engineer-thea-energy-kearny-g9b7nhmpksyx'
type: 'job'
last_seen: '2026-09-09'
---

# Computational Nuclear Engineer at Thea Energy

- **Company:** Thea Energy
- **Location:** Kearny, NJ
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-08-19
- **Last confirmed live:** 2026-09-09
- **Apply:** https://jobs.lever.co/thea.energy/58ed4eaf-1e73-4877-a6cf-14e6604ad1d3

## Job description

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

It’s not necessary to meet all of the skillsets outlined above. Please feel free to send us a note and tell us why you would still be a great fit for this role or Thea Energy.

Diversity and Inclusion: Thea Energy is an equal opportunity employer committed to creating a company of diverse backgrounds. By creating a diverse environment, we will bring new ideas and approaches to solving some of the world’s hardest (and most important) problems. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, sexual orientation, gender identity or expression, national origin, family or marital status, age, disability, veteran’s status, or other characteristic protected by applicable laws and regulations.

## About Thea Energy

## Company Overview
- **One-liner**: Thea Energy is developing a simplified, economical stellarator fusion energy system using arrays of mass-manufacturable planar magnets and dynamic software controls.
- **Entity Type**: Private (Startup; founded in 2022)
- **Headquarters**: Kearny, New Jersey, USA
- **Founded**: 2022
- **Founders**: Founded with technology developed at Princeton University (specific founder names not publicly listed on main site).

## Core Business
- **Primary industry**: Fusion Energy / Clean Energy / Climate Tech
- **Target customers**: Utilities, grid operators, industrial energy users, and governments seeking baseload, zero-emission power generation.
- **Mission**: "To create a limitless source of zero emission energy for the future of humanity." [thea.energy](https://thea.energy/)

## Products & Services
- **Eos (Neutron Source Stellarator)**: A near-term commercial neutron source designed to achieve world-leading fusion performance and de-risk their first fusion power plant. [thea.energy](https://thea.energy/)
- **Helios (Fusion Power Plant)**: The company’s first planned full-scale fusion power plant, intended for commercial electricity generation. [thea.energy](https://thea.energy/)
- **Software-Defined Magnetics Platform**: The core technology differentiator—replacing complex, expensive 3D magnet coils with arrays of simpler, mass-manufacturable planar magnets controlled by a sophisticated software stack. This transfers hardware complexity into the digital realm. [thea.energy](https://thea.energy/)

## Market Standing
- **Valuation / Total Funding**: Not publicly disclosed.
- **Key Metric**: Private startup; notable for its technological breakthrough rather than public revenue. The company has active job postings (41 roles listed on Indeed) and is in a high-growth hiring phase. [indeed.com](https://www.indeed.com/cmp/Thea-Energy/about)
- **Notable Investors/Partners**: Announced a collaboration with **NVIDIA**, **Synopsys Inc**, **Argonne National Laboratory**, and **Princeton Plasma Physics Laboratory (PPPL)** to build the first digital twin of a stellarator fusion power plant using AI physics and engineering. [indeed.com](https://www.indeed.com/cmp/Thea-Energy/about)
- **Growth Signals**: Rapidly growing team; active hiring across engineering, supply chain, finance, and marketing roles; partnership with major tech and national lab players; progression from a science project (Eos) toward a commercial power plant (Helios).

## Competitive Advantages
- **Planar Magnet Arrays**: Replaces the prohibitively complex and expensive 3D coils of traditional stellarators with simple, mass-manufacturable planar magnets. This radically reduces cost and manufacturing complexity. [thea.energy](https://thea.energy/)
- **Software-First Approach**: Transfers the geometric complexity from hardware to a dynamic software control system, leveraging decades of progress in computing and controls to simplify the physical build. [thea.energy](https://thea.energy/)
- **Stellarator Advantage**: The stellarator is the only magnetic confinement system that creates all required fields with superconducting coils, enabling steady-state operation (no plasma disruptions), which is a key advantage over tokamaks. [thea.energy](https://thea.energy/)

## Strategic Focus
- **Commercialization of Eos**: Achieving near-term fusion performance and commercial operation with their neutron source stellarator.
- **De-risking Helios**: Using Eos as a stepping stone to validate technology and reduce risk for their first full-scale fusion power plant.
- **Digital Twin Development**: Leveraging AI and simulation (with NVIDIA, Synopsys, Argonne, PPPL) to accelerate design, operation, and optimization of their fusion systems.
- **Scaling the Organization**: Building out a multi-disciplinary team spanning fusion science, engineering, supply chain, and business functions.

## Why Work Here
- **Mission-Driven Work**: Opportunity to work on one of the biggest challenges facing humanity—creating limitless, zero-emission energy. [thea.energy](https://thea.energy/careers/)
- **Culture**: Described as dynamic, flexible, and adaptive, balancing strong individual autonomy with a collective team spirit. Employees are empowered to take ownership of their career growth. [thea.energy](https://thea.energy/careers/)
- **Diversity & Inclusion**: Explicitly committed to building a diverse workplace and encourages applications even if candidates don't meet every listed requirement. [thea.energy](https://thea.energy/careers/)
- **Work Model**: Roles are listed as **On-site** in Kearny, NJ (for most technical and corporate roles) and some internships. [jobs.lever.co/thea.energy](https://jobs.lever.co/thea.energy)
- **Benefits**: Competitive salaries, health benefits (medical/dental/vision), employee equity, 20 days PTO, paid holidays and sick time, paid parental leave, 401k, life and disability insurance, and office perks. [thea.energy](https://thea.energy/careers/)

## Sources
1. [thea.energy](https://thea.energy/)
2. [thea.energy/about-us](https://thea.energy/about-us/)
3. [thea.energy/careers](https://thea.energy/careers/)
4. [jobs.lever.co/thea.energy](https://jobs.lever.co/thea.energy)
5. [indeed.com](https://www.indeed.com/cmp/Thea-Energy/about)

## Other roles at Thea Energy

- [Manager, Strategic Sourcing & Technical Subcontracts](https://feeny.ai/job/manager-strategic-sourcing-technical-subcontracts-thea-energy-kearny-06g92h82d76h) — Kearny, NJ
- [Communications Associate](https://feeny.ai/job/communications-associate-thea-energy-kearny-12p9kmfws884) — Kearny, NJ
- [Buyer/Planner](https://feeny.ai/job/buyer-planner-thea-energy-kearny-jk2zmr1vzg4c) — Kearny, NJ
- [Physics Intern - Fall 2026](https://feeny.ai/job/physics-intern-fall-2026-thea-energy-kearny-dhryh9hjn1bm) — Kearny, NJ
- [Plasma-Material Interaction (PMI) Manager](https://feeny.ai/job/plasma-material-interaction-pmi-manager-thea-energy-kearny-f483kg4r7q71) — Kearny, NJ
- [Manufacturing Engineering Intern - Fall 2026](https://feeny.ai/job/manufacturing-engineering-intern-fall-2026-thea-energy-kearny-mmxhg3t29fpx) — Kearny, NJ
- [Contract - Senior VFX Network Engineer](https://feeny.ai/job/contract-senior-vfx-network-engineer-thea-energy-remote-08ee6kf1ceg5)
- [Director - Site Development](https://feeny.ai/job/director-site-development-thea-energy-kearny-tk3n6pgnmg0g) — Kearny, NJ
- [FP&A Manager](https://feeny.ai/job/fp-a-manager-thea-energy-kearny-nmnsk5kxe19g) — Kearny, NJ
- [Integrated Modeling Intern - Fall 2026](https://feeny.ai/job/integrated-modeling-intern-fall-2026-thea-energy-kearny-4bg8sxp9at91) — Kearny, NJ