Magnox – Virtual Reality (VR) Simulation of Decommissioning Facilities
Magnox are currently engaged upon a programme of works to decommission two nuclear reactors at their Winfrith Site. Magnox engaged Cineon Training to create a virtual environment that would enable workers to gain experience of a nuclear flask handling facility prior to its installation.
Cineon Training developed the proof-of-concept functional training tool based upon the envisaged nuclear waste handling process utilising a virtual reproduction of the waste transfer flask. This tool was also to inform the design development process and provide a means for testing the efficacy of the simulated environment through Cognitive Task Analysis.
We spent time with the Magnox Engineering Team responsible for the work area and storyboarded the process to ensure that all envisaged steps were included. From this a list of 47 individual actions were generated.
We worked from existing CAD drawings in the form of a 3D ‘NavisWorks’ model which was converted into a real-time virtual environment. Using game engine software we added functionality and design elements such as sound effects, and surface textures to make the work area as realistic as possible.
The Virtual Reality simulation was then accessed via a Head Mounted Display (HMD) and ‘touch’ sensors were used to enable operators to turn keys and wind winches.
“enable workers to gain experience of a nuclear flask handling facility prior to its installation”
In order to validate this virtual reality simulation as an effective training tool, we ran a study with subject matter experts.
We conducted a short survey and performed cognitive task analysis to establish the cognitive and motor skill challenges that the VR model simulates. We examined the subjective views of the SMEs, and captured objective data through psychometric tests and in-vivo performance metrics, the results of which would help us to establish the efficacy of the simulation as a training tool.
Construct validity refers to the extent to which the VR simulation appropriately simulates the real-world task. In this instance we had no comparison to the real-world (as the real-world flask facility does not yet exist) and as such we would not perform a construct validity assessment following the usual ‘within subject’ approach (comparing each subject’s performance in the real-world and the VR environment to make comparisons).
To overcome this we performed a ‘repeated measures assessment’, comparing performance across two repetitions of the same task with the VR environment, which showed that that performance improved in all but one task after just one repetition, and the standard deviation (the variation and range in values) was lower for the second iteration of the task.
This suggests that all subjects were learning, and that the consistency of performance was increasing after only one repetition.
We also performed a ‘between subjects correlative assessment’, exploring differences in VR performance based on differences between the users.
“This suggests that all subjects were learning, and that the consistency of performance was increasing”
This research suggests there is merit in adopting this simulation to (1) prepare operators for tasks prior to construction of the real-world facility, and (2) further explore design and use issues, in order to inform the on-going design and constructions process.
“This research suggests there is merit in adopting this simulation”
By creating a VR version of the equipment users were able to test the flask handling process and highlight areas where improvements could be made to the equipment, which were fed back to the client. By modelling the process virtually, we were able to inform the design and improve system processes.
Importantly, this will allow the training of operators without the risk of plant damage or injury.