Nuclear Reactor Engineer

Reactor Physics & Neutronics Engineer — Micro Modular Reactor

Pisa, Italy · Onsite · Permanent · 50-60,000 € + bonus

Design the core of a reactor that will actually get built

Most nuclear engineers spend a career optimising someone else's core. This is a chance to define one from a blank sheet.

Our client is a nuclear technology company developing a Micro Modular Reactor — small enough to transport, simple enough to deploy where grid power doesn't reach, and designed to produce both clean electricity and medical and industrial radioisotopes .

They are currently taking the design through the US NRC licensing process , which means the neutronics work you do here doesn't sit in a report. It goes into a licensing submittal, and then into hardware.

Why this role is different:

• Real scope, real ownership. A (team size) engineering team, not a 400-person division. Your core design decisions reach the CTO the same week you make them.
• Licensing-grade work. Your analyses become part of a formal NRC submittal — the highest-rigour environment in the industry, and a credential that follows you for the rest of your career.
• Two missions in one machine. Carbon-free power and isotope production for cancer diagnostics and treatment.

What you'll own

You'll be the reactor physics authority on the MMR core — from first-principles modelling through to defending your numbers in front of a regulator.

• Core design & optimisation — define and iterate the core configuration, working the trade space between reactivity, thermal limits, cycle length and manufacturability.
• Neutronics analysis — criticality and reactivity coefficients, burnup and depletion, cross-section generation, flux and power distributions.
• Shielding & dose — shielding design, dose rate calculations, and validation of radiation barriers.
• Fuel cycle — fuel management strategy and fuel cycle analysis for a first-of-a-kind core.
• Licensing support — produce the analyses and technical documentation that support the NRC submittal, and engage directly with regulators and reviewers.
• Safety analysis — support risk assessment and failure mode analysis on reactor components alongside the safety team.
• Method & tool development — improve the models, workflows and verification practices the team will rely on for the next decade.

What you'll bring

Essential

• MSc in Nuclear Engineering, Reactor Physics, or a closely related field.
• Strong grounding in reactor physics — you can explain why a core behaves the way your model says it does.
• Hands-on experience with at least one Monte Carlo or deterministic neutronics code: Serpent, MCNP, SCALE, PARCS , or equivalent.
• Working knowledge of nuclear safety principles and a regulatory framework (NRC, IAEA, or a national equivalent ).
• The engineering judgement to know when a result is wrong before the reviewer tells you.
• Clear written English — your documentation will be read by regulators.

Nice to have (genuinely optional)

• PhD in reactor physics, neutronics, or radiation transport.
• Experience contributing to a licensing submittal or safety case.
• Micro-reactor, SMR, HTGR, molten salt or research-reactor experience.
• Radioisotope production experience.
• Scripting for automation and coupling (Python).
• Italian — useful for working with (the Italian engineering team / partners), not required.

Don't tick every box? Apply anyway. Deep strength in core design and neutronics matters far more to us than a complete checklist.