Magnetic Containment Could Produce Continuous Fusion

News in December 2022 that scientists at Lawrence Livermore National Laboratory (LLNL) had achieved scientific energy breakeven with nuclear fusion after decades of trying has validated the idea that nuclear fusion might one day provide a source of clean carbon-free energy. Energy breakeven means that the fusion reaction produces more energy than the energy input that is used to drive it. 

 

Creating fusion with magnetic containment. Image used courtesy of Type One Energy

 

Fusion, in this case, was accomplished by creating a plasma of hydrogen isotopes of deuterium and tritium at temperatures of 100 million degrees Kelvin. Energy is released as the hydrogen combines to form helium. 

Fusion represents the possibility of complete energy transformation and decarbonization, according to Nicolas Sauvage, president of TDK Ventures.

At the temperatures required to form a fusion reaction–about six times hotter than the temperature at the sun’s core–the hydrogen plasma that forms cannot be contained in a solid and must be held within a magnetic field within the fusion reaction chamber. To be successful, however, the hydrogen isotopes must be forced together for long enough and at a high enough temperature for fusion to occur. 

 

Stellarator

A Wisconsin company called TDK Ventures, working with Breakthrough Energy Ventures and Doral Energy-Tech Ventures, is assisting with the funding of Type One Energy. This group of scientists from the University of Wisconsin, Oak Ridge National Lab, and Max Planck Institute for Plasma Physics has developed a magnetic confinement concept using advances in 3D printing (also called additive manufacturing) and the application of high-temperature superconductor magnets.

Type One Energy is developing the stellarator (created initially in 1951) that uses shaped 3D magnetics to confine plasma gases along a twisting circular path. At present, most fusion energy concepts use pulses of fusion energy. The steady-state operation would have significant advantages for a baseload powerplant operation, and the stellarator is viewed as one way to accomplish this. 

Because the stellarator’s performance is controlled by the fields generated by external magnets, it is relatively stable and simple to operate. A stellarator can also operate continuously, allowing the possibility of continuous steady-state operation of the fusion reaction. 

 

Fusion represents the possibility of complete energy transformation and decarbonization, according to Nicolas Sauvage, president of TDK Ventures.

 

In 2015, the Wendelstein 7-X experimental stellarator at Germany’s Max Planck Institute for Plasma Physics was developed to demonstrate the concept of continuous fusion reactions. Although this stellarator did not achieve energy breakeven, it helped to define the challenges faced with such a goal. Among these are achieving an effective magnetic field and the difficulty in manufacturing non-planar magnets with complex geometries. Type One Energy is applying 3D printing (additive manufacturing) to overcome this technical challenge and build optimized stellarators. 

Traditional nuclear power has employed fission reactions for commercial power generation. In a fission reaction, uranium atoms are split into two smaller atoms, releasing energy. Controlling a fission reaction is complicated if meltdowns are to be prevented. The result is radioactive waste materials that must be stored for hundreds or even thousands of years. A fusion reaction does not use radioactive uranium fuel, and the fusion reaction ceases if a failure occurs, making fusion nuclear power inherently safer.