Fusion doesn't start in the reactor—it starts on the computer
When I read in today’s Heidenheimer Zeitung that components for fusion power plants are to be manufactured in the future on the site of the former Gundremmingen nuclear power plant, I had to look twice. Just a few kilometers from our corporate headquarters in Heidenheim, a new industrial hub is currently taking shape for one of the most exciting future technologies of all.
My first thought was: What an impressive development.
My second thought, however, was: Actually, we’ve been involved with this topic for many years now.
That makes me all the more pleased that Merkle CAE Solutions will be part of the TIL Fusion network in the future. For us, this membership isn’t an entry into a new field of technology, but rather the logical continuation of a development that began years ago.
Fusion is not new territory for us
Many people associate nuclear fusion exclusively with giant tokamaks, superconducting magnets, or extreme temperatures of over 100 million degrees Celsius.
For engineers, however, the real challenge begins much earlier.
Before a fusion reactor can even be built, countless technical issues must be resolved. How do components behave under extreme thermal stresses? What vibrations occur under extreme load conditions? How can highly sensitive components be protected from particles or molecular contaminants? And how can all these questions be answered long before a prototype even exists?
This is precisely where the world of numerical simulation begins.
Our Experience with ITER
ITER is currently the world’s largest research project dedicated to the development of nuclear fusion and is considered a major step toward future commercial fusion power plants.
Several years ago, we had the opportunity to collaborate with various partners on projects related to the international ITER fusion project in Cadarache.
One key focus was contamination control within the reactor sectors. Even the tiniest metallic or organic particles can impair the function of highly sensitive components. At the same time, the construction of a fusion reactor spans many years, and in some cases even decades. Even components that were originally clean become recontaminated during this time and must be reliably cleaned again before commissioning. Together with our project partners, we developed concepts that allow for the analysis and optimization of particle transport, cleaning, and the prevention of recontamination as early as the planning phase.
Using computational fluid dynamics simulations, various cleaning concepts were evaluated and examined for their effectiveness. The effectiveness was successfully demonstrated in a pilot project using a replica heat exchanger and was later applied at the Cadarache facility to clean the installed heat exchangers.
Other, even earlier projects focused on the seismic safety of the high-voltage deck at the ITER facility in Cadarache. The components used there must function reliably even under extreme dynamic load conditions. Using extensive structural dynamics and seismic simulations, we were able to examine, evaluate, and optimize the behavior of the structures in detail as early as the development phase.
These projects have impressively demonstrated the demands that future fusion power plants will place on development, quality assurance, and simulation. Much of the experience gained there can be directly applied to new challenges today.
Why Simulation Is Essential for Fusion
Nuclear fusion presents engineers with extraordinary challenges. Extreme temperatures, strong magnetic fields, thermomechanical load cycles, and the most demanding requirements for materials and manufacturing quality call for a deep understanding of system behavior.
Experiments alone are insufficient for this purpose, both in terms of time and cost.
Numerical simulation makes it possible to analyze structural mechanics, thermal behavior, fluid flow, particle transport, and coupled multiphysics phenomena as early as the development phase. Weak points become apparent, design variants can be evaluated, and development can be significantly accelerated—long before the first component is manufactured.
Especially when it comes to future technologies such as nuclear fusion, the digital twin thus becomes a crucial development tool.
Fusion doesn't just begin in the reactor.
It begins many years earlier—on the computer, in simulations, and in the minds of the engineers who have the courage to break new ground.
Yours Stefan Merkle
