Digital twinning is increasingly viewed as one of the key innovations for increasing safety and efficiency in nuclear plants.

A digital twin is a digital model of a process that helps optimize or predict performance. And they are becoming more widespread in nuclear plants to help maintain and maximize operations.

Leading systems and engineering technology experts Frazer-Nash Consultancy, based in the UK and Australia, are at the forefront of digital twin technology across multiple sectors, ranging from Formula 1 motor racing to nuclear.

Dr Peter van Manen, Service Development at Frazer-Nash, believes the nuclear sector can benefit greatly from digital twinning as it can monitor the integrity, efficiency, predict plant condition and, importantly, help reduce maintenance costs.

And those costs are significant. According to research undertaken by Frazer-Nash, over the 60-year lifetime of the UK’s 16GWe fleet, savings of 3.7 billion pounds (US$4.65 billion) could be made.

“A digital twin is an approximation of something that is real,” Dr van Manen told Nuclear Energy Insider. “We use it to predict what might happen, to expose characteristics of a system that may be difficult to detect.

“If you take something like a nuclear reactor, one of the problems is that it is very difficult to put sensors inside as it is a very hostile environment, so that naturally means you rely upon inspections and historical information.

“Having a digital twin allows you to frame some of this data in a better way against the physics and the chemistry that is going on.”

Consistency of prediction

Dr van Manen cites the analogy of a satellite navigation system, which we rely on to tell us if there is a traffic jam ahead or if there is an accident that we could avoid and take a safer and quicker route. The information the satnav uses is a sample of the traffic on the road coupled with its knowledge of the road network.

“You rely on the information it gives you as it gives consistency of prediction and you get to the point where you don’t think it could be incorrect,” he says. “The uncertainty is quite low because you have the right level of measurement and the right level of monitoring. So the satellite navigation system is essentially a digital twin of the road network.”

Trusting a satnav is one thing but relying on a mathematical model to run a nuclear power plant is a major leap of faith. However, that is not stopping many operators turning to digital twins.

“It’s a mixture of saving on maintenance, increasing performance of the plant and understanding better what your plant is doing and its capacity,” says Dr van Manen.

Those savings could be significant, with 2% being a “reasonable assumption” for a plant that is already operational. For a new plant under construction or at initial planning stage, the gains could be even greater. Introducing a digital twin at an early stage can increase efficiency and reduce the cost of construction.

Testing scenarios

GE says that using a digital twin allows operators to test “what if” scenarios against business objectives, allowing for more informed decisions.

GE’s own industrial platform, Predix, has been designed to manage huge volumes of industrial data at scale, integrated with business applications to allow plant executives, plant managers and workers to interact with the digital twin in real time.

Exelon, for example, has been working closely with GE Predix and has seen business impact in regards to safety, cost management and performance.

GE says its digital twin uses advanced sensor technologies coupled with artificial intelligence and big data gathered from tens of thousands of hours of operation to inform the digital twin of potential efficiency gains while monitoring every aspect of the plant.

Digital twin technology is not, however, solely applicable to large-scale nuclear plant and equipment. When there are complex decisions to make or a trade-off between two or more options, the digital twin provides a virtual area that enables you to explore options quickly, optimize outcomes and arrive at a balanced compromise. It allows the complex interaction of people, plant, processes and environment to be modelled and interventions to be implemented.

This empowers an organisation to learn and store knowledge about how its assets behave, in order to improve operational strategies and reduce risk.

Speaking in 2017, then GE Chief Technology Officer Sham Chotai outlined one of the cost benefits of the then emerging digital twin technology.

“For instance, a compressor might fail. In the case of a nuclear plant, that can cause a scram and it can cost millions of dollars to bring a plant back online,” he said. “Using the concept of the digital twin combined with deep machine learning we are able to predict 30 to 60 days ahead that a compressor will fail.”

Gaining traction

While many plants have already integrated digital twin technology, many more are expected to take it up in the next five years, with older plants also able to embrace the technology thanks to being built on common IT technology that will support the digital transformation.

“Old legacy assets can benefit as the digital twin can provide you with a better idea of how much life is left in the plant and can do so with a higher level of certainty,” says Dr van Manen.

“Where you have high value assets then you want to extend their life or gain more value from them.”

Digital twins in the nuclear power industry are becoming more widespread every year, according to Dr van Manen.

“Each time that digital twins prove they are successful, there is an openness to consider their application,” he says. “It would be wrong to say they are being used extensively but they are certainly gaining traction quite quickly as they prove their worth.”

While operational efficiency gains are significant, the ability to avoid potential downtime through predictive maintenance and monitoring while increasing safety and plant life are also essential to the bottom line.