Stabilizing the Plasma

Nuclear power is becoming one of the most viable options for a truly renewable and highly efficient energy source. Of its two variants, nuclear fusion, can supposedly provide even greater energy. In fact, just recently, a South Korean nuclear reactor brought us closer to reaching the “holy grail” of energy research.

Nuclear fusion is the product of a process that’s essentially the opposite of fission. It generates several times more energy than fission by combining two light nuclei (usually hydrogen isotopes). Stabilizing this process, however, still largely eludes us due to difficulties in controlling the super-hot plasma that keeps the reaction going.

The KSTAR (Korean Superconducting Tokamak Advanced Research) reactor was able to sustain the high-performance plasma for a record 70 seconds. This may sound like a trifle, but sustaining the plasma needed in fusion involves hitting the “triple product” — its particle density, its confinement time, and its temperature.

Challenges and Potential

The KSTAR team reached the plasma state using a completely non-inductive mode and a high-power neutral beam. Heat on plasma-facing parts of the reactor was reduced to workable levels by creating a 3D spinning field, which was combined with a groundbreaking method that allowed for higher plasma pressures at lower temperatures.

“The success of KSTAR in ITB operation has enabled us to study the new fusion reactor operation technology that can realize the necessary operation mode for future fusion power plants,” explains KSTAR Research Center.

Nuclear fusion research has made considerable progress this year. Just last October, MIT’s now retired Alcator C-Mod tokamak fusion reactor managed to reach record-breaking levels of plasma pressure. Now, KSTAR is able to actually prolong stable plasma life.

“This is a huge step forward for realization of the fusion reactor,” according to NFRI.

When we finally develop reactor technology that can make nuclear fusion practical, we will have access to an authentically renewable energy that can provide four times the energy of fission (one fission event yields around 200 MeV of energy, or about 3.2 ´ 10-11 watt-seconds). On top of this, it is also cleaner, with very low expected carbon emissions.