Upgrading the simulator at Torness nuclear power plant

EDF’S TORNESS PLANT IS A two-unit advanced gas-cooled reactor (AGR) on the east coast of Scotland, 33 miles east of Edinburgh.

Torness is a sister plant to GSE partner EDF Energy’s Heysham 2 station, on England’s north west coast. GSE upgraded the Heysham 2 simulator in 2012 and was selected to upgrade the similar Torness simulator. The intent was to upgrade the Heysham 2 simulator with some of the improved models developed for Torness. EDF hoped that by keeping the two simulators in line, they could save costs on simulator support and maintenance by sharing resources.

However, the life extension plans at Torness included significant plant upgrades and the simulator was no longer reflecting the current plant environment. Additionally, the original simulator did not have the capabilities and modern simulation technology used in other simulators in the EDF Energy fleet. The power plant needed a new approach to simulation as well hardware and software upgrades.

Since operators play a vital role in the safe operation of the Torness reactors and the associated generating equipment, an upgrade was essential. They needed a high-fidelity central control room simulator to perform their control and oversight functions effectively. It would enable individuals and teams to be trained through normal plant operations and evolutions, as well as postulated fault scenarios. To ensure the operator’s performance and behaviours meet world-class standards, EDF provides five weekly training sessions for each of its five operator shifts.

The solution

GSE mapped out a plan to upgrade the process models using modern and maintainable simulation software (improving the fidelity and accuracy of the simulation), and incorporate modern simulation features to enhance training and incorporate recent plant changes. This would mean replacing the original simulation computers, as they could no longer accommodate the more sophisticated simulation technology being deployed.

The GSE simulator upgrades were designed to provide more detailed operator training on plant process relationships, and malfunction recognition and response, including:

• More realistic training. Instructors no longer needed to work around deficiencies or explain the difference between the simulator and the real plant.
• Improved model response. To ensure operators better understand how the plant will perform under a variety of incidents, GSE developed additional malfunctions that allowed operators to ‘experience’ more situations, gain confidence, and improve response to the same events in the plant.
• Enhanced interaction with auxiliary systems, improving on some shortcomings of the previous simulator.

Additionally, the Torness project featured:

• Unit 2 simulation: As a two-unit plant sharing certain common systems, including electrical, auxiliary and cooling, the operation of one reactor can influence the performance of the other. The original Torness simulator facility had a complete replica of the Unit 1 desk and common systems, but only a partial, static, and non-operational mockup of the unit 2 desk. There was no capability to train on site-wide events or model the interaction between the two reactors on common systems. EDF chose to invest in a complete and integrated model of the unit 2 desk, allowing simultaneous training on both reactors for key plant scenarios. To achieve this, GSE built the unit 2 model and integrated it with the common systems, requiring a unique testing scheme for each simulator plus the combined plant.
• Emulation of the complex data processing and control system (DPCS): This system, which was old by power plant standards, did not have a modern virtual solution. GSE analysed the detailed design of the control algorithms, graphical display screens, and internal calculations and recreated the functionality of the DPCS using GSE simulation software tools. The work included hundreds of thousands of lines of code and 510 unique graphical display pages.
• Soft panels: GSE’s scope included developing additional simulation complexes using soft panel displays rather than hard panels. The soft panels had interactive touchscreens so the operators would manipulate panel instrumentation that was similar to the actual hardware. GSE also connected the soft panels to the simulation model to respond to operator actions in real time and to be used in the classroom and the debrief room. The soft panels provided a cost-efficient way of reflecting the unit 2 desk, instead of purchasing older analogue instruments and the associated input/output systems.
• Debriefing technology: Plans included a richer, more meaningful debrief room experience. A copy of the just-completed simulator session can be replayed to show operators how well they performed and correct any actions. The simulator replay is synchronised with the audio and video system in the simulator control room, so the students can watch their own performance. This effective and timely feedback is a key element of EDF’s training programme.

Another challenge: the pandemic

COVID-19 affected the Torness simulator project, as it did many others around the world.

The simulator development process, including design, coding, and preliminary testing, first began at GSE’s facility in Maryland in the USA. The project shifted to Scotland in 2019, which required a team of eight GSE engineers to move temporarily to complete hardware software integration and final testing. The team was in place when the pandemic hit, and travel restrictions were imposed.

The timeline, which had looked like smooth sailing up to that point, was suddenly looking at a work stoppage, huge delays, and quarantining of the GSE team.

The team chose to stay in Scotland, continuing work and forgoing planned trips home, displaying the team spirit behind the Torness upgrade initiative as well as committed customer service.

“GSE proved to be the best partnership for this project. I was impressed by the team, their dedication, professionalism, and overall delivery of the simulator project,” says EDF’s Richard Cawkwell. “All this in the wake of the COVID pandemic. Their team was exemplary, and I cannot praise them enough.”

Progress has been maintained: “Despite the additional complications that COVID-19, we are now starting to see delivery of training on the new simulator,” says Dermot O’Loughlin, operations manager at the Torness nuclear power station. “So far, initial feedback has been very positive. We are looking forward to testing our operators with the full functionality available to ensure Torness maintains its excellent safe reliable generation record,” O’Loughlin adds.

Author information: Gill Grady, Senior vice president, GSE Systems