Robots in the Hot Zone: Cleaning Up the Nuclear Sites Humans Can't Enter

Nuclear decommissioning is the ultimate dirty, dangerous, and dull job. Some corners of a wrecked or ageing reactor are so radioactive that a human would absorb a lethal dose in minutes. For decades that made parts of these sites effectively unreachable. Robots are changing that — and 2026 is the year they stopped being an experiment and started being staff.

Sellafield: the robot dog clocks in

Sellafield, in Cumbria, is one of the most complex nuclear sites in Europe, home to some of the world's most hazardous buildings. For roughly two years, engineering firm AtkinsRéalis has been deploying a customised Boston Dynamics “Spot” quadruped there. In 2025 the team reported a milestone: operating the robot remotely from outside the site's licence boundary, over a highly secure network with live-streamed video — pulling the human operator out of the danger zone entirely. Spot's kit reportedly includes 360-degree imaging, LiDAR scanning, gamma and alpha radiation characterisation, swabbing and environmental monitoring, letting it map and sample places like the Pile Fuel Cladding Silo. In early 2026, Sellafield reported it would move the robots into “routine, business-as-usual” operations — not a demo, a day job.

Fukushima: 22 metres of robotic arm

In Japan, TEPCO faces a harder task: retrieving the melted fuel debris fused inside the ruined reactors of Fukushima Daiichi. In April 2025 it reported completing a second trial retrieval from Unit 2, using an improved 22-metre telescopic robot nicknamed “Telesco” to extract a fragment weighing just 0.187 grams. Analysis reportedly detected americium-241 and europium-154 — chemical fingerprints of nuclear fuel. Minuscule as it is, the sample matters: an estimated 880 tonnes of fuel debris remain, and every gram teaches engineers how to plan a removal that will take decades.

Why this is the real frontier

It is easy to be dazzled by dancing humanoids. The more consequential robotics may be these unglamorous machines inching into spaces that would kill a person in minutes. The work is slow, the payloads are measured in grams, and progress is counted in years. But this is exactly where robots earn their keep — not by replacing human workers, but by reaching where humans simply cannot go. Both programmes point the same way: from one-off trials toward a permanent robotic presence in the most hazardous corners of the nuclear age.