Date of registration 2020-09-24
German company Siemens realizes smart factory
based on digital technology
Virtual reality ITER
When Tony Stark, the protagonist of Iron Man, creates Iron Man nano suit with the arc reactor in his chest, he goes through a series of processes such as designing the suit, making a prototype, trying out the prototype, checking its size, testing its performance. Such technology to embody real machines, systems or environment in a virtual space including computer and to reflect all available variables such as materials, time, temperature, and pressure in real time to use them for the production of a prototype, monitoring, simulation, and optimization is known as ‘digital twin.’ Digital twin, which perfectly combines real physical world and digital virtual world, is also to be used in nuclear fusion research.
As the name implies, ‘digital twin’ refers to digital twins that exist in the virtual world. It is the concept advocated by U.S.-based consumer electronics company General Electric (GE) and is characterized by the interactions between twins in the computer and in reality based on data. Digital Twin enabled people to experiment with various circumstances reflecting reality, predict results, save technology development costs, and enhance the efficiency of industrial sites.
Although the concept spread mainly in the manufacturing industry in the 2000s, it is now acting as a problem solver in a wide range of areas such as aerospace, defense, construction, energy, and urban design. For example, Singapore pursued the national digital twin platform called ‘Smart Nation Project’. It created digitally twinned smart cities in collaboration with global companies, and used these cities as a test stage for various urban administrations, including urban population distribution, transportation, environment, and commercial districts. The result was, of course, a successful city construction.
Various digital twins have been also witnessed in the field of nuclear fusion. Digital twin is a key tool that leads to success in large construction projects such as International Thermonuclear Experimental Reactor, or ITER. ITER Organization is operating a virtual reality room (VR room) that adds 3D visualization technology to simulation. The ITER cannot allow even small errors in the assembly and manufacturing process because hundreds of thousands of components must be perfectly aligned and interlock like cog wheels. That is because ITER experts are looking for optimal assembly method and sequence in the VR room. The large 2.5m (wide) x 4m (high) screen displays vivid 3D images featuring the nuclear fusion device’s cooling water piping system, vessel support, and other plant systems or components, thereby serving as a venue where experts of each ITER device can gather together to discuss the optimal interface. They can also send and receive 3D data directly with the ITER CAD database through software.
Digital twin is also an effective tool to overcome the extreme environment of nuclear fusion. The inside of the fusion reactor, where the ultra-high temperature plasma of 100 million degrees Celsius is faced with superconducting magnetic fields, is an environment hardly accessible by humans. The Joint European Torus (JET), an experimental nuclear fusion reactor, manages the nuclear reactor by means of remote handling of robots in the control room built outside the reactor. Such technology of remote handling that transmits human movements to robot arms is a kind of digital twin. In addition, France’s nuclear fusion device called Tore Supra and China's nuclear fusion device called East have introduced digital twin for remote maintenance of nuclear fusion reactors.
South Korea’s KSTAR can also encounter digital twin in the next two years. In May 2020, NFRI started the ‘digital twin-based nuclear fusion energy facility operation’ project in May 2020. The project is being participated by SF Technology and VR Media, companies specializing in digital twin, and Sangmyung University.
Dr. Kwon Jae Min, Director of Advanced Physics Research Division of NFRI, who is in charge of this project, said, “It is possible to maximize the performance of KSTAR by reflecting all operational elements such as plasma temperature, pressure, and magnetic field strength, as well as all device properties that make up KSTAR in digital twin”, adding “Prevention of collapse in ultra-high plasma and control of superconducting magnetic fields are challenges that the nuclear fusion industry has long faced. I expect that a more challenging and reliable nuclear fusion research would be possible if experiments on each variable are conducted and an optimization method is derived.”
In order for digital twin to be competent as expected, digital KSTAR must realize even the same plasma motions as real ones. What is needed to this end is to maximize the performance of computer simulation with high quality data secured by KSTAR. A variety of simulation codes and physical models for tokamak plasma have been developed so far. In particular, this year, a new supercomputer will start operation, which is the key resource for the simulation researchs has also been strengthened.
The goal of the digital twin project is the first stage of development that simulates various nuclear fusion issues and derives an optimal solution. Such issues include how plasma is generated and sustained, how heating beams energize plasma and create hot spots in tokamak walls facing plasma. The project aims to remotely control the actual KSTAR via digital KSTAR in the later stage of the development.
Digital twin is also in line with the Virtual DEMO (V-DEMO) which is being prepared by NFRI for the purpose of construction of a nuclear fusion demonstration reactor. In the near future, we hope that the digital KSTAR can be used with real KSTAR through expanding collaboration with NFRI, fusion community, and industries.