About the Company

Humanity faces two critical challenges: securing reliable energy for everyone and aggressively lowering our environmental impact. Nuclear fission is the key to solving both at once, and our client is actively developing the technology to rapidly scale the deployment of nuclear fission today.

This is a direct hire, permanent placement position for a client of AdAstra Talent Advisors. This position is based in El Segundo, CA. More company details will be shared during an initial call.

The Opportunity

As the Sr. Nuclear Engineer, you will take end-to-end ownership of the nuclear design and safety analysis of our client’s first nuclear reactor — spanning core design and fuel cycle, reactivity control, and radiation release and dose analysis. You will advance the design from today’s working simulation models through design finalization, licensing, and first criticality, and will build the analysis tools and methods needed to do it at unprecedented speed.





You will also own the highest-impact analyses and design decisions while setting the technical bar for the nuclear engineering team. Successful candidates will have previously demonstrated extreme ownership in modeling, analyzing, or de-risking complex physical systems, and will be highly motivated to power humanity with abundant, clean energy.

Responsibilities
- Support key aspects of nuclear core design including fuel assembly design, reactivity control through burnable poisons, chemical, and mechanical shim, thermal hydraulics, and fuel cycle design
- Own reactivity control design and analysis: control rod worth, shutdown margin, reactivity coefficients, chemical and mechanical shim, and transient response
- Perform radiation shielding and release analysis against regulatory limits
- Work closely with fluids, structures, components and manufacturing teams to deliver a highly system-optimized and manufacturable design
- Maintain tight partnerships with fuel procurement supply chain including enr

📌 Senior Nuclear Engineer (Pereira)
🏢 Adastra
📍 Pereira