Nuclear fusion: A shot at true clean energy

Researchers in the UK recently revealed that they had achieved a new milestone in generating fusion energy during the most recent experiment conducted with the Joint European Torus (JET) machines, as per CNN's report.

According to the UK Atomic Energy Authority (UKAEA), a group at the JET facility near Oxford in central England produced 69 megajoules for a duration of five seconds using 0.2 milligrams of fuel. This quantity of energy could sustain approximately 12,000 households for the same period.

This experiment marked the conclusive trial at the JET site utilising a toroidal machine known as a 'tokamak'.

The JET facility, short for Joint European Torus, stands as the most extensive and sophisticated tokamak globally. A tokamak functions to confine plasma within a toroidal shape using magnetic fields, with the aim of achieving nuclear fusion.

Since its inception in 1983, JET has made significant progress in fusion science and engineering.

Nuclear fusion, akin to the process occurring in the sun, holds promise for addressing climate change by offering a plentiful, safe, and eco-friendly energy source. Fusion inherently presents safety as it lacks the potential to initiate a runaway process.

"JET has operated as close to power-plant conditions as is possible with today's facilities, and its legacy will be pervasive in all future power plants," Ian Chapman, UKAEA CEO, told CNN.

Over four decades, more than 300 scientists and engineers from EUROfusion, a consortium of researchers spanning Europe, have contributed to JET's groundbreaking experiments.

Within JET's tokamak, 0.1 milligrams each of deuterium and tritium, both hydrogen isotopes, underwent heating to temperatures 10 times hotter than the sun's core to produce plasma. Magnets maintained this mixture in position as it rotated, leading to fusion and the release of substantial heat energy.

Deuterium is readily available in seawater, while tritium can be obtained as a byproduct of nuclear fission.

Per unit weight, fusion releases nearly four million times more energy than burning coal, oil, or gas, with helium being the sole waste product. But the Lawrence Livermore National Laboratory in the US was the only facility to achieve this feat — the pinnacle of nuclear fusion — in late 2022, utilising a distinct process involving lasers.

JET conducted its inaugural deuterium-tritium experiments in 1997.

The results unveiled on Thursday showcased the capability to sustain fusion for five seconds, as prolonging beyond that duration would risk overheating JET's copper wire magnets.

ITER, the International Thermonuclear Experimental Reactor, aims to prolong the fusion process beyond 300 seconds by incorporating superconductor electromagnets into its design.

If ITER progresses as planned, a prototype fusion power plant could be operational by 2050.

But despite achieving a new milestone, JET did not surpass the energy input with output.

Moreover, fusion energy, touted as a potential game-changer for the climate crisis caused primarily by human burning of fossil fuels, is a technology that still requires many years of development before it can be commercialised.

Aneeqa Khan, a research fellow in nuclear fusion at the University of Manchester, emphasises that by the time fusion technology is fully matured, it may be too late to deploy it as a primary tool to combat climate change.

Nevertheless, numerous hurdles persist. Khan notes that the energy expended to conduct fusion experiments exceeds the energy generated, underscoring the ongoing challenges.

"This represents a significant scientific achievement, yet commercial fusion implementation remains distant. Constructing a fusion power plant entails numerous engineering and material obstacles," she remarked.

"Despite these challenges, investment in fusion is increasing, and tangible progress is being made. It is imperative to cultivate a skilled workforce for this field, and I anticipate the technology will see utilisation in the latter half of this century," she added.

The announcement of this breakthrough coincided with the EU's climate and weather monitoring service, Copernicus, confirming that global temperatures had surpassed the critical threshold of 1.5 degrees Celsius over a 12-month period for the first time.

While scientists express greater concern regarding prolonged warming beyond this threshold, the milestone serves as a symbolic indicator that the world is approaching a level of climate change it may struggle to manage.

According to climate science, the world must nearly halve its greenhouse gas emissions by the end of this decade and achieve net-zero emissions by 2050 to prevent catastrophic global warming. This necessitates a swift transition away from fossil fuels such as coal, oil, and gas.

Historically, international collaboration on fusion energy has been strong because, unlike nuclear fission employed in atomic power plants, fusion technology cannot be weaponised.