Source: International Atomic Energy Agency – IAEA
“A training is conducted in a full-scope simulator at the construction site of the United Arab Emirates’s Barakah nuclear power plant in February 2016.” (Photo: Louise Potterton/IAEA)
Students and professionals in the nuclear power field are taking on learning opportunities while being housebound during the COVID-19 pandemic. Requests to use the IAEA’s basic principle nuclear reactor simulators have risen sharply in recent weeks. New users will have the opportunity to learn more about operating them at an IAEA webinar on 12 May.
“This suite of nuclear power plant simulators is part of the IAEA education and training programmes on technology development of advanced reactors and can be accessed upon request by interested parties from around the world,” said Stefano Monti, Head of the IAEA’s Nuclear Power Technology Development Section.
These simulators include several features to help users understand fundamental concepts behind the behaviour of nuclear power plants and their reactors, including the most widely used water-cooled reactor types. They also provide an overview of how various plant systems and components work in harmony to power turbines and produce low-carbon electricity.
In the integral pressurized water reactor (IPWR) simulator, for instance, users can navigate through several screens, each containing key information allowing them to adjust certain variables of the reactor’s operation. One provides a summary of reactor parameters such as primary pressure, flow and temperature. Another view lays out the status of the reactor core. The “Systems” screen provides a visual overview of how the plant’s main systems, including the reactor and turbines, work together. And on the “Controls” screen, users may adjust values which affect reactor performance and power output.
This simulator not only provides insight into how this IPWR works. It also allows users to see how the changes they make to plant variables alter the plant’s operation, and perform manoeuvres similar to what would take place in the course of actual plant operations. For example, users can reduce power output to mimic what would happen in a “load following” scenario. Load following is performed when, for example, the demand for nuclear-generated electricity decreases, due to decreased demand or increased availability of power from other sources.
“Currently, most nuclear plants operate in ‘baseload’ mode, continually generating electricity at their maximum capacity. However, there is a trend of countries moving toward hybrid energy systems which incorporate nuclear together with a diverse mix of renewable energy sources. A greater need for flexible nuclear operations is emerging, and many advanced power plants offer standard features for load following,” said Gerardo Martinez-Guridi, an IAEA nuclear engineer who specializes in water-cooled reactor technology. “It is important for prospective nuclear engineers to understand the dynamics of the consequences of reducing a reactor’s power output, for example, and simulators can be very effective in helping students visualize these processes.”
Like pilots taking off or landing on an aviation simulator, users of a simulator can perform a variety of manoeuvres. For example, to reduce power using the IPWR simulator on a hypothetical 45 MW (e) SMR operating at 100% capacity, the user moves to the Rods Position Control area of the Controls screen to change the plant mode from “reactor leading” to “turbine leading”; in this mode, the reactor’s output changes depending on the turbine load demand. Once this step is complete, the user navigates to the Turbine Control area and reduces the turbine load demand from 45 MW (e) to 40 MW (e) (or another desired power level), changes the turbine load rate to 2 MW/minute (or the desired rate), and clicks “Go”. From here, much like in a real IPWR design, everything else is essentially automatic. The control rods are partially inserted into the virtual reactor core, reducing the reactor power output to match the turbine demand, and the user can then observe changes in variables such as neutron flux and feedwater flow, and compare them with the initial values at 100% power.
“Many reactor variables change when the power output is adjusted, and it is useful to see how this occurs in real-time,” said Chirayu Batra, an IAEA nuclear engineer who will lead the upcoming webinar. “Users will know that the operation is complete once the various parameters have stabilized at their new values.” Observing and comparing the parameter changes helps users know what to expect during a real power manoeuvre, he added.
Two IAEA publications provide overviews of how simulators may support capacity building and also classify them for application in education and training.