The world’s biggest operational experimental nuclear fusion reactor - a technology in its infancy but billed by some as the answer to humanity’s future energy needs - has been inaugurated in Naka, Japan.
Fusion differs from fission, the technique used in nuclear power plants, by fusing two atomic nuclei instead of splitting one. The goal of the JT-60SA reactor is to investigate the feasibility of fusion as a safe, large-scale and carbon-free source of net energy - with more energy generated than is put into producing it.
The six-storey-high machine, in a hangar in Naka, north of Tokyo, comprises a doughnut-shaped “tokamak” vessel set to contain swirling plasma heated up to 200mC (360mF).
It is a joint project between the European Union and Japan, and is the forerunner for its big brother in France, the under-construction International Thermonuclear Experimental Reactor (ITER). Despite numerous delays over the years, ITER is aiming to achieve full plasma generation by, originally, 2030 - but after numerous delays, the date keeps slipping back. While this may be consistent with a common adage in the power industry: “Fusion power is always just 10 years away,” progress in harnessing fusion is unquestionable, and, if commercial fusion is achieved, the current generation is likely to see a total revolution in energy in their lifetimes.
The ultimate aim of both projects is to coax hydrogen nuclei inside to fuse into one heavier element, helium, releasing energy in the form of light and heat, and mimicking the process that takes place inside the sun.
On the other side of the Pacific, a Virginia startup called NearStar Fusion is trying a bold new approach to achieving the holy grail of clean energy. NearStar believes it can harness modern railgun technology to achieve abundant green energy more efficiently than fusion dependent on lasers - which is what both the JT-60SA and ITER are using.
Instead, NearStar is firing plasma railguns at hydrogen fuel to ignite the fusion reaction. The world is taking note, as this method promises to drastically reduce the energy input required and, theoretically, should make achieving commercial viability easier. The race is on!