Nuclear Security Engineer

Full job description

About the work

Mercor is assembling a panel of nuclear materials and safeguards experts to red-team frontier AI models. The goal is to test whether a model can correctly judge the misuse potential of a technical request — answering legitimate questions fully while refusing genuinely dangerous ones.

You will:

• Write challenging single-turn prompts in your domain, labelled across three levels: benign, dual-use, and adversarial.
• Evaluate the responses that come back against a defined policy standard, and judge whether each was handled correctly.
• Write the reference answer — what a correct response looks like, and the technical reasoning for why.

This domain lives on the dual-use line more than most. The same material-balance calculation that closes an inspector's account can be used to hide what is missing from it; the same protection assessment that hardens a facility maps its weaknesses. A model that refuses a routine material-accounting question is failing as badly as one that answers a question it shouldn't. Drawing that line reliably is why we need practitioners rather than generalists.

Background we're looking for

We're looking for people who have been responsible for keeping nuclear material where it belongs — material control and accountability, physical protection, and the assessments that test both. What matters most is being able to tell a routine professional question from one that's fishing for something else: the same vulnerability assessment that closes a gap also describes it. You will be writing prompts that sit exactly on that line, then judging whether the model held it.

Examples of relevant backgrounds (ideally with red-teaming experience):

• Material control and accountability (MC&A) programme design, operation or assessment at a national laboratory or licensee
• Physical protection system engineering — sensors, barriers, delay, response force, performance testing
• Vulnerability assessment and adversary path analysis for nuclear facilities
• Insider threat and human reliability programme work
• Nuclear security policy, training or international assistance programmes

What this role demands beyond technical depth

This is writing-intensive work. Every judgment you make needs a written rationale that a non-specialist can follow. Prior technical writing, published research, or expert witness experience is a strong signal; please include a sample or link. You will also be reading and writing about misuse scenarios in your field for sustained periods. We brief experts on this in advance, and you can pause or step away at any point without penalty.

Before you apply

Your work here will not involve, and must not draw on, classified or export-controlled information, or anything covered by an NDA or prepublication review obligation. If you hold such obligations you may still be a good fit; tell us in your application and we will scope the work accordingly.

Last checked open on Oct 28, 2026. Job description provided by Mercor.