Radiological Security Specialist - Expert

Mercor; Toronto; On-site; CAD 90,000 - 130,000; Full time

Job summary

Mercor is assembling a panel of radiological safety 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 prompts across benign, dual-use, and adversarial levels, evaluate responses, and craft the reference answers with detailed reasoning for policy compliance.

Qualifications

• Strong written rationale for judgments accessible to non-specialists.
• Experience writing prompts across benign, dual-use, and adversarial categories.
• Ability to evaluate model responses against defined policy standards.

Responsibilities

• Write challenging prompts in benign, dual-use, and adversarial categories.
• Evaluate model responses against policy standards.
• Write reference answers with technical reasoning.
• Provide clear written rationales for judgments.

Skills

Red-teaming experience

Technical writing

Analytical thinking

Domain knowledge: radiological safety

Job description

About the work

Mercor is assembling a panel of radiological safety 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 isotope underpins cancer therapy and industrial radiography; the same shielding calculation protects a worker and conceals a source. A model that refuses a routine dose 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 assessed how Category 1 and 2 sources actually get stolen, shielded or moved — the security and vulnerability side of a licensed programme, not just its paperwork. What matters most is being able to tell a routine professional question from one that's fishing for something else: the same shielding calculation protects a worker and conceals a source. 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):

• Security or vulnerability assessment of licensed facilities holding Category 1 and 2 sources
• Physical protection design and review — detect, delay, assess and respond; insider threat considerations
• Source recovery, consolidation or security-upgrade programmes for disused and orphan sources
• Regulatory security inspection and compliance — 10 CFR 37 or national equivalents
• Transport security for radioactive material — routing, escort, tracking and chain of custody

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.