Partner: Atkins
We live in a world that is becoming increasingly virtual. The metaverse beckons, promising new ways of relating to each other and of doing business. But the benefits, in most of our daily lives, are unclear, will the virtual and augmented realities that are being constructed amount to much more than updated versions of Pokémon Go or Second Life? Or will they just accentuate the many harms we see already online?
For engineers, however, the creation of representations in the digital world offers real world value. They can bring certainty and accuracy to planning, replacing an unstructured mess of legacy data with a ‘single source of truth’ model, that brings together both old knowledge of a site, and freshly generated scans. Which can be used to plan projects safely and efficiently.
This approach has particular benefits in the nuclear sector, where sites are built over a span of decades and have specific hazards, that demand certainty and conservatism from project managers. By creating digital twins of these sites, steps in the decommissioning process can be planned out in the virtual world, allowing them to be performed efficiently while reducing the need for staff to enter hazardous areas.
In this article we will learn about how digital twins are used for nuclear decommissioning.
A generational site
Jonathan Gill is a Lead Mechanical Engineer at Atkins. He has worked on nuclear waste decommissioning projects in the UK, at Sellafield, and in Canada. A site like Sellafield poses some unique challenges.
“Sellafield has been there since the 1950s. It was, originally, used to develop munitions as part of the Cold War. and then eventually moved on to power generation. And now it’s going into its later life, of decommissioning,” says Gill.
Over the decades that a site like Sellafield has been in use, change has been constant. Much of the knowledge of how and why a site has changed is stored in the heads of those who work there. Institutional knowledge.
“And of course everyone comes to their retirement at some point, so you lose that information and that data knowledge. So you want to be able to capture that, as far as possible, to be able to understand why the asset is in the state it is in, how it came to be like that, what configuration control has been done.”
In a facility designed for other uses, decision-making rationale might also be lost.
“[In Sellafield] we’re trying to do a process that the site, wasn’t designed for. And with that high hazard environment you want to try and keep exposure to the minimum.”
Where changes at the site have been recorded, this was often done before anyone could guess how data would be used in the 21st Century.
“There’s a huge amount of data,” says Poppy Harrison, an Engineer at Atkins. “It’s not been structured, because generally in nuclear decommissioning, those assets have been operational for years and years before we had good information management principles, before we knew what data to collect, and why to collect it.”
This is not a problem that is unique to nuclear decommissioning. These sites are not terribly managed. A lot of older assets in many sectors have this issue where data has not been managed as modern technicians would like.
Gill adds, “Some documentation may be held on a system, but it may be that because of the way that the data has been held, it is erroneous compared to what has actually been done.”
So you get two extremes, you get one level of data not being collected, and you don’t have as good an idea as you would like, and on the other hand you have too much data, and it’s not structured and you don’t know what to do with it.
Making the data from a site like this useful, first requires thought about what is being recorded, how it is structured, and then how it is represented.
“You start with the problem, right?” says Harrison. “Which is true of most engineering. What are you trying to solve? What are you trying to do? What’s your end goal? And that will relate to what you need to do with that data.
“You can’t define all your processes and just say, we’re going to make a digital twin, this is what we’re going to do. And sometimes a digital twin isn’t the right solution. I think that’s important to remember, you know, we’re not trying to say you definitely need this, this is 100% what you need. Are there other solutions we can offer? It comes back to what your problem is.”
It is important not to gather data for the sake of gathering data. Unstructured, underutilised and unrequited information.
“The digital twin tends to help focus and leverage the important data,” says Gill. “And then the true value of the data that we want. There’s a concept where there’s ‘data’, and then there’s actual useful ‘information’ to take out of that data. And that’s what the digital twin is meant to assist clients with, gathering data to deal with the decommissioning process.”
The knowledge baseline
The digital twin gives you a much a much more improved knowledge baseline to work off than other methodologies. Much like the consumer ‘metaverse’ the concept of a ‘digital twin’ is wide and, often, ill-defined.
Harrison says, “Everyone’s got their own definition, and you can kind of consider it from every level from very basic, are you looking at reality capture, so point clouds from laser scanning and photogrammetry all the way up to what people more traditionally probably think of as digital twins. So autonomous solutions, you look at machine learning and AI linked in with robotics. So a lot of the benefit and the value add from something you might call a digital twin, or you might not, comes more from that lower level reality capture, virtual mock up side of things.”
Gill adds, “Digital twins generally don’t have to be a 3D model, it can just be a digital representation of a physical asset or process. And we see the ability to, with decommissioning it’s really helping the client as well as the project team understand the inventory, the information available, what’s there so that they can understand their waste streams, and overall their liabilities that they have for their asset.”
The data on a project like this may be held only on paper, and may not have been well archived.
“Some parts of sites,” says Harrison. “Are already pretty well documented, you don’t need to go in and do this if it’s not necessary. Other parts might be more complicated, you might have drawings from many years ago that you know, someone’s put a cigarette out on, and you can’t read anymore.”
Or bad handwriting from decades before may not be clear to everyone. On a nuclear decommissioning project, it is in the ability to precisely plan site interventions that a digital twin shows its value.
“What the benefit of a digital twin is, especially a data rich, visualisation-style, digital twin,” says Gill. “Is it gives the ability to stakeholders to view their site, avoid having to do pre-job briefs, preparation, dose monitoring, etc. That is all timely, costly, and can also be seen as unnecessary, now that we’ve got the capability of digital means of 360-degree videos, laser point cloud scans that can all be held within the single source of truth platform, which we know as a digital twin.”
That single source of truth can be accessed from anywhere, in a conference room away from the power station itself.
Harrison explains, “A lot of nuclear safety is, ‘Can we get people away from this?’ ‘Do we need to put people in suits and put them in the area?’ ‘Do we need hands in glove boxes?’, for example. And digital is a really great enabler of ensuring sort of safety and security and making sure we can keep the people that are working on these projects and are often working in nuclear environments for many years, making sure they’re not exposed unnecessarily to anything.”
Experts anywhere in the world can also be involved, without the environmental impacts and general inconvenience of international travel.
“The nuclear industry is not huge. So quite often, people aren’t necessarily conveniently located right next to your local power plant. So if you can save on that, that’s also a real benefit,” says Harrison.
The cloud-based nature of a digital twin means that everyone can access that single, authoritative, model. At any time, from anywhere in the world. And the accuracy of digital twins means that more accurate forecasts can be made.
“So it also helps the client and, it’s a bit of a boring thing to say, but it helps with costing and pricing as well as just planning,” says Harrison.
On a congested, frequently reconfigured, site like a nuclear power plant, planning a load path for equipment moved in and out of a facility can be a challenge. An unanticipated obstacle might block movement of the load through the site. On any site, that can cause delay and additional costs. On a nuclear site, where staff must minimise their dose of radiation, it is much more critical. The traditional way to manage risks on a project is to include a wide safety margin on any movement. But that can mean the best engineering solution for a problem is made impossible.
“That means that say, you’re trying to plan a job or at the very early stages, you’re making concept designs or proposals, it’s really hard, you’ve got a lot of uncertainty in there. So you’re going to have to use a lot of tolerances that you might not need,” says Harrison. “You can take some of that away, you can be a little bit more certain or a little bit more confident in your pricing and in your design, and maybe you can take away some of that conservatism.”
The precise measurements used to build a digital twin, and their accurate representation in a four-dimensional model, including time as well as space, means that unanticipated obstacles can be avoided.
Gill adds, “For example, if you’ve got a large piece of steel work, or a component and you and you know that there’s maybe a routing sort of concern from the client, of how it works, you can, you can go through and do effectively do the job within the digital twin, just through these animations, thereby saving the time for the pre job brief, saving the time for getting the staff ready and all this.
“And then as well, actually bringing in the component, realising it doesn’t actually fit through your alley way. And then you’re back to square one. And you’ve just wasted time and money. So the digital twin then allows you to effectively carry out carry out work in the digtialised space, and hopefully, and hopefully give you the right informed decision about what the component needs to be, for them to then carry out the task in reality.”
With an accurate digital twin, augmented reality can be used to plan jobs like this.
“There was a bay within Sellafield,” Gill continues, “that they were looking to install a platform, to do enabling works. And we were able to identify through augmented reality, through the digital twin, that there were clash detection issues.”
The fourth dimension in a digital twin can extend much further than the duration of a single job. As well as measurements of physical and temporal dimensions, a twin can include specific data relevant to the site. On a nuclear site, worker health is protected by limiting the dose of radiation staff receive. One way to do this is through dosimeters. These are physical devices, carried by workers while on site, that record how much radiation they have encountered. They will tell the wearer if they are receiving a dangerous dose of radiation.
Traditional planning approaches limit the time workers spend in areas with high doses of radiation. As with moving equipment through site, this requires taking a very conservative approach. A digital twin can work alongside this approach, removing the need for physical presence at the site when planning work. But it can also allow for more precise predictions of the dose that a worker will receive, allowing more accurate and appropriate safety margins to be used.
“Are there any areas they want to try and avoid and therefore,” says Gill, “ensure a low risk because ultimately, lower risks means lower costs to the operators and—in the case of a lot of the UK fleet—taxpayers?”
In many sectors, sensor monitoring of assets is used to predict maintenance requirements, without humans on site. This sort of monitoring can be incorporated into a digital twin, making planning of maintenance visits more efficient and effective.
Digital twins are accessible on standard computer hardware, through a desktop or web application that connects to a definitive version in the cloud. As you’d expect in a nuclear environment, it is designed to meet the most stingent security standards.
The process of building a digital twin, identifying the data you need to collect, collate, and structure, and representing it in a way that will best meet project needs may take around a year. Or it may take much less.
With pre-existing data, and new data collected during the construction of the twin, in place, it can then be used and added to throughout the life – and afterlife – of a real-world asset, whether that is a power station, an industrial site, or a utility. Within the nuclear sector alone, there will be plenty of demand for a ‘single source of truth’ on assets.
“By 2030, 2035, there’s estimated to be in the region of 50 to 100 nuclear reactors that are looking to move into decommissioning because they’re coming to the end of their design life,” says Gill. “Within the UK, quite a few of the EDF and Magnox fleet are also in that case. So we see that with Sellafield as a prime example we can of showcase these cost savings and the benefits that and then ensure that nuclear decommissioning isn’t such a headache.”
A safer physical reality, grounded in a growing digital reality.
