In experimental nuclear fusion plants in both the U.S. and Europe, scientists are fighting to pass the magical threshold where the reactor outputs more energy than what it consumes. When we reach this, we can in theory generate practically unlimited power. However, there are major obstacles in our way to get there.
What is Nuclear Fusion?
Fusion is the same type of nuclear power that makes the sun and other starts burn. Instead of to atoms being split apart like we do in nuclear fission plants, fusion is the name of the process when to atoms melt together. To achieve this, we need massive amounts of heat.
Is nuclear fusion possible? Nuclear fusion has in fact been done several times, but so far not with a net gain in energy. Beam-target fusion, beam-beam fusion and lastly thermonuclear fusion are the most known methods to harness nuclear fusion. This article will focus on the last one since it at this stage is the most promising.
How Does Nuclear Fusion Power Plants Work?
International Thermonuclear Experimental Reactor (ITER)
The construction of ITER in Cadarache in southern France has already started. If everything goes as planned, this experimental fusion reactor will be fired up as early as in 2018.
This power plant will be the world’s largest tokamak, a type of nuclear fusion that utilizes toroid shaped reactors (looks like a donut). Magnets around the donut to keep gases with incredible temperaturs and pressures in place, conditions that can be compared to those of the sun.
Inside the donut-shaped reaction chamber, hydrogen gas (detrium and tritium isotopes) is heated to 100 million degrees before the fusion can take place. The process must be completed without any further addition of energy, before the reactor can be called a success.
Experiments on nuclear fusion has been conducted previously in Princton Laboratory (U.S.) as well as Joint Thermonuclear Reactor JET (England). The latter one holding the current record with an energy output of 16 MW – a net loss of several hundred MW. We hope that ITER will push this record even further, bringing us closer to commercial fusion.
Scientist argue if we can actually harness nuclear power through a method known as cold fusion. Fusion energy is harnessed at room temperature, by using a set of chemical reactions instead of heat. We have yet to see any real proof for cold fusion.
Fusion of deuterium pulled out from 1L sea water is equivalent to the energy in 300 L petrol. There is no doubt that the potential of nuclear fusion is big. Unfortunately we have a long way to go.
Read more about fusion power in Nuclear Energy Pros and Cons.
Below is a video of Steven Cowley’s presentation about nuclear fusion on TED in 2009. I highly recommend watching it.