The UK’s National Centre for Nuclear Robotics is developing machine vision, artificial intelligence and advanced robots to decommission the country’s 4.9m tonnes of nuclear waste.
Launched in 2018, the NCNR is a consortium of eight universities led by the University of Birmingham and backed by £42m of funding. Its primary mission is to develop robotic solutions that can characterise, handle and decommission the huge amounts of waste generated by the nuclear industry over the past since the early 1950s.
Using current technology, the clean-up would take 120 years and an estimated one million human entries into contaminated zones, with a cost of approximately £234bn. According to the NCNR, developing robots capable of taking up the task is a necessity for a number of reasons.
“There’s a large amount of radioactive waste that humans can’t go near at all,” Prof Rustam Stolkin, co-director of the NCNR, told a press event at the Royal Institution. “And where we have technology that’s now becoming capable to do the complex things that human workers do, we have an ethical and moral obligation to stop using humans in those roles. We don’t send Victorian children up chimneys any more. It’s not socially acceptable.”
Where humans can deal with nuclear waste, they must be kitted out in air-fed plastic suits, usually wearing multiple layers and gloves for protection. But they must often also operate heavy tools, such as disc grinders, for dismantling the metal piping and containers that make up much of the legacy waste. It’s tiring and dangerous work, limited to just a couple of hours at a time. And for every barrel of high-level waste that is decommissioned, 11 further barrels of secondary waste – such as contaminated suits and gloves – is created. Using machines would help cut down on this secondary waste, but the sector has largely proved resistant to the adoption of robotics.
“Nuclear is a profoundly un-roboticised industry,” said Stolkin, head of Birmingham’s Extreme Robotics Lab, which is at the vanguard of NCNR’s research. “The reason that you’ve been able to have this (robotics) revolution in manufacturing, is because manufacturing is a very structured, constrained, precise environment.”
Conversely, nuclear waste is completely unstructured, and therein lies the challenge. What’s required is machine vision and AI that can characterise waste objects with no prior knowledge, enabling robots to deal with the waste autonomously. While this is a relatively simple task for a human – radiation levels notwithstanding – it is incredibly complex for a machine and represents the bleeding edge of current AI research.
“Autonomous robotic grasping is the current forefront frontier in international robotics and AI research,” Stolkin explained. “You can’t buy a robot from an industrial robot manufacturer that can do that stuff. Well, we buy the robots, but we make them behave in clever ways.”
On top of this, the robots obviously need to be resilient to high levels of radiation, as well as capable of mapping and navigating areas where no human has set foot since in 70 years. And it’s not just grasping that the robots will be required to do. NCNR has already used a robot to cut contaminated steel with a laser, the first time ever a robot has been allowed to act autonomously inside a radioactive zone.
Further afield, NCNR has also been involved in operations at Chernobyl using drones to map radiation levels in the infamous ‘Red Forest’, the most highly contaminated area following the 1986 nuclear disaster at the plant. Under the lead of NCNR co-director Prof Tom Scott and working alongside Ukrainian authorities, the team successfully identified a previously unknown radiation hotspot within the forest. It’s hoped the drone mapping system, along with other NCNR advances, can be spun out to commercial applications beyond the nuclear industry.
What about all the plutonium up at Sellafield? 112 tonnes I believe, 40% of the world store and one of the most dangerous chemicals, let alone the nuclear risk. We can’t sell it or give it away and it can’t be dismantled! How will this be tackled so as not to leave a toxic legacy?
If we use molten salt reactors we can feed them with plutonium and ‘burn’ the radioactive materials. Plutonium can be converted and even be commercial in the process. We have no nuclear policy.
I believe the USA is looking into a system to produce electricity for nuclear waste. If this system can be developed that would that lease put this material to a useful end?
Plutonium is already being used to produce electricity in current generation reactors as MOX (mixed oxide fuel). It fissions into various relatively short lived isotopes which are allowed to mostly decay in the spent fuel ponds.
We should be taking this one step further and breeding non fissile U238 into Plutonium and then using it for power generation.
Plutonium is chemically no more toxic than other similar heavy metals.
It is unclear to me why there is such emphasis on AI and machine vision.
I believe that, if it is hazardous, or difficult, for people to go in then remote controlled robots might be a better and easier option (and if a robot fails then it could be retrieved via its control cables) and the case for autonomy is not at all evident (as people are good at assessing things – though possibly some augmented reality viewing might assist)
I suspect that there is a need for such robots to access difficult locations – and this might require more sophisticated locomotion(worm like?) and development of positioning and of gripping, forming and cutting tooling; such technology could well have important medical application too – which would be good – and a very useful development of robotics technology (autonomy raises all sorts of ethical and trust issues – who would want a medical robot deciding to quick lobotomy??)
The types of waste are mentioned but, by implication, the secondary waste is just as hazardous as the primary – and needs to be disposed of the same way; I do not believe that this is correct at all – obviously someone trying to make a “business case”
I agree that the radioactive actinides pose a disposal issue – but that is a political desire for dumping/burial rather than a re-use/recycling option.
It’s somewhat unclear exactly what is meant by ‘nuclear waste’ in the article. There are already systems for dealing with spent nuclear fuel however there is currently little political will for reprocessing (Uranium is also too cheap). I assume (always dangerous) that the article is referring to decommissioning waste rather than fuel waste. The secondary waste referred to, suits and gloves, is currently landfill rather than anything of significant activity. The key action in most decommissioning is to wait for most of the radioactivity to decay. By basic physics high activity material decays faster than low activity material.
And indeed much of policy to date has relied on waste material decaying to more manageable levels. The issue is that many of the facilities used for this purpose are themselves nearing their end-of-life, meaning other solutions must now be pursued.
Pu can be used in any reactor type – it does not need to be a molten salt design. I believe (the late) Westinghouse once suggested building 16 of their larger AP1000 PWRs which would dispose of the Pu in about 40 years. But I agree – we have no nuclear policy, in fact no energy policy at all other than ‘leave it to the market’ to which the market responds simply by putting the price up. True Pu is being used in MOX but the rate of use is very small – the enrichment percentage is relatively small in AGR fuel so the Pu content in MOX will be just that percentage less the 0.7% natural U235 content as a ballpark figure. This will take a long time to use and our present fleet will all be closed by 2035 according to current plans, possibly apart from Hinkley C when it eventually generates (if ever).
It’s probably better to use Pu in a reactor which takes metallic fuel than in MOx, because MOx is so difficult to make: like a Wedgewood teacup, as one nuclear fuel specialist once told me. Metallic fuel forms tend to be more forgiving.