The last time a human entered the Pile Fuel Storage Pond at the Sellafield nuclear site in Cumbria, England, was in 1958, when records show a maintenance operator and health physics monitor carried out a dive into the newly constructed pond to repair a broken winch. At least that was true until December 2022, when Josh Everett, a diver from the U.K. specialist nuclear diving team Underwater Construction Corporation (UCC) UK Ltd., became the first person in more than 60 years to work in one of the most unique workplaces in the world.

Robotics experts from Sandia National Laboratories and representatives from the Department of Energy Office of Environmental Management’s Technology Development Office recently visited the Sellafield nuclear site in England to discuss how robotics, artificial intelligence, and other emerging tools can be developed and used in nuclear cleanup operations.

The United Kingdom’s nuclear renaissance

The United Kingdom’s nuclear industry is expanding, with the U.K. government committed to supporting the build of more civil nuclear power plants (deployments up to 24 GW by 2050)¹ while also undertaking large-scale decommissioning work in parallel.² The defense sector is experiencing growth with the decommissioning, operation, and new build of submarines, plus managing the U.K.’s deterrent.³ Although the civil and defense programs are separate, they draw on the same group of skills and people.

The Windscale Piles, circa 1956. (Photo: DOE)

After the Atomic Energy Act of 1946 ended collaboration between the United States and its World War II allies (specifically, the United Kingdom and Canada), the British government felt it necessary to go down its own path in developing nuclear technology. As a result, the Windscale Piles, in Seascale, Cumberland, England, were planned and built with the aim of producing plutonium for the U.K.’s defense purposes. Windscale Pile No. 1 became operational in 1950, and Windscale Pile No. 2 followed shortly after in 1951.

Early in the design process, the U.K. government came to realize that it did not have an adequately expansive piece of land that could provide a safety barrier in case of an issue at a water-cooled reactor. If the flow of water coolant were to be interrupted, an evacuation and exclusion zone could require a large land area that Britain simply did not have. The government, therefore, decided to construct both reactors with a natural draft air convection core cooling system. A massive cooling chimney at each reactor would soar nearly 400 feet into the air.

The U.K. National Nuclear Laboratory’s Colin Fairbairn (left) and Ben Smith (in pre-COVID days) work on the Box Encapsulation Plant (BEP) robots project at the NNL’s facility in Workington, Cumbria, U.K. Photos: UKNNL

Though robotics solutions have been used across many industries, for many purposes, Sellafield Ltd has begun to bring robotics to the U.K. nuclear industry to conduct tasks in extreme environments. The Sellafield site, in Cumbria, United Kingdom, contains historic waste storage silos and storage ponds, some of which started operations in the 1950s and contain some of the most hazardous intermediate--level waste in the United Kingdom. There is a pressing need to decommission these aging facilities as soon as possible, as some of them pose significant radiation risk.