HUGE AMOUNTS OF MONEY ARE typically spent each year on the design and validation of the human-machine interfaces (HMI) and the optimisation of operating procedures at nuclear facilities. But there may be a better way.

The virtual reality (VR) control room at Finland’s Loviisa nuclear plant came in at less than a tenth of the cost of a conventional physical simulator, and operator Fortum says it also provides new opportunities for training and can be used to validate new equipment further upstream.

The cost of physical control room simulators is so high because they require an exact, functional replica of the real environment. And there is a practical issue: because the physical simulators are usually fully booked, it doesn’t leave much time for additional testing or evaluations. In contrast, the cost of a virtual replica is a fraction that of a physical simulator, and changes can be implemented quickly in VR.

Already 90% of the staff at the two-unit Loviisa station have done some basic training in VR. Virtual reality, including 360 degree content, is now also part of the basic curriculum, where it is used for plant familiarisation, fire evacuation drills and to practice maintenance/inspection processes.

The VR development was undertaken in Fortum Nuclear R&D, and is currently developed by Fortum eSite, a subsidiary dedicated to industrial training in virtual reality, supervised by Joakim Bergroth, a human factors specialist with a decade of experience in the nuclear industry.

“Our VR efforts go back five years,” says Bergroth. At the time, Loviisa was in the midst of a huge instrumentation and control upgrade project and the HMI teams needed to be able to evaluate control room designs more quickly. “In 2016, we did our first subsystem validation in VR, which was a part of the ELSA project, and we had good results,” says Bergroth.

Since then, the teams have been working to improve functionality and update the system to take advantage of the latest developments in VR technology. Another “pre-integrated system validation” was conducted in VR in 2017, over 6 months before the actual planned ISV on the physical simulator. “The findings in this VR validation, gave us plenty of time to fix design errors before anything was even installed on the physical simulator,” Bergroth adds.

To further develop its VR simulator Fortum turned to Varjo, a Finnish start-up and developer of the Varjo VR-1, a high-resolution virtual reality headset designed for professional use. Its dual-screen system makes it possible to distinguish details. The high resolution makes it possible to more accurately represent the control panels, screens and other elements of the simulator.

“Previously, when you needed to look at dynamic displays in a simulated VR environment, you would usually lean closer to the display to see the parameters and symbols clearly. That’s not something you would do in the real world. You were forced to do it because the resolution was not good enough. With the Varjo VR-1, the problem has finally been solved. Virtual environments can now be explored in a realistic way,” Bergroth says.

A crucial aspect in safety-critical environments is the design process. For nuclear control rooms, validations are a compulsory part of the process. All operator procedures, new display systems and hardwired panel designs must be validated in physical simulators before they are brought into use. This is to ensure that the control room works as intended.

Before VR simulators, validations were typically done very late in the project, and a design change meant time- consuming changes in the physical simulator on site. This was costly and ineffective, and in the worst cases could lead to project delays of up to 12 months. With the help of VR, pre-validations and evaluations can be done several months ahead of time.

“After the pre-ISV in VR, we were confident that we had all the biggest errors fixed. And we did. It saved us thousands of working hours, and monetary-wise probably hundreds of thousands of euros,” Bergroth says.

The realism of the VR simulator also meant Fortum eSite was able to add elements to the training not previously possible. “We can add natural phenomena like fire, smoke, flood or earthquakes that are impossible to accomplish in a physical simulator or environment,” Bergroth said. “It is possible to get the stress factors to a more realistic level, so that we can learn more about how well our human machine interfaces are working. Also, the operators are more prepared if something like that happens in real life.”

The new VR-1 includes eye tracking, which can help Bergroth and his team to analyse operator performance and get information about how well the user interfaces work.

During training, the staff cannot always tell which procedures the operator trainees are using, as they do not have visibility of which page or sentence the trainee is following in the manual.

The integrated eye tracking functionality in VR-1 gives new insight into operator behaviour. Trainers can follow trainees’ eye movements accurately and give them automatic assignments. For instance, if the procedure says that the trainee needs to check a value from the hardwired panels, with the help of real-time gaze data, a trigger assigned in the VR environment can notify trainers if the trainee does not complete the action quickly enough after reading the instructions, or at all.

Fortum is now planning a project. The next phase could see heartbeat sensors added to give even greater insight into how the human machine interfaces support the operator, and how the operators feel and act in stressful situations.

Bergroth sees immense potential in transforming the way nuclear power plant operators are trained globally. But in the near future, he also expects to see VR taken into use in many other safety-critical and process industries, as full-scale, full-scope VR simulators are cheaper than physical simulators. “With VR-1, the end users in nuclear operations and many other industries are more likely to see and accept the possibilities of VR and what it brings to their industry. That is game-changing,” says Bergroth.

Main image: Loviisa nuclear plant in Finland has built a dedicated virtual reality training room (Photo: Jani Ylinen, Varjo)