UK nuclear fusion facility completes experiments for the first time in 40 years

“It felt great. Working on a design is one thing, working with it is another.”

Professor Barry Green talks about the moment in June 1983 when Oxford’s JET Fusion Laboratory conducted its first experiment.

For the next 40 years, European projects pursued nuclear fusion and the nearly limitless potential of clean energy.

But the world’s most successful nuclear reactor will conclude its final tests on Saturday.

Nuclear fusion was “discovered” in the 1920s, and research in the following years focused on developing fusion for nuclear weapons.

In 1958, after U.S. war research on nuclear fusion was declassified, the United States engaged Russia, Britain, Europe, Japan, and the United States in a race to develop fusion reactions to provide energy.

Nuclear fusion is considered the holy grail of energy production because it releases large amounts of energy without emitting any greenhouse gases.

It is the process that powers the Sun and other stars. It works by taking pairs of light atoms and forcing them together. This is the opposite of nuclear fission, where heavy atoms split apart.

The UK and Europe decided to work together and the Joint European Torus (JET) site was born. Scientists were brought to Cullum in Oxfordshire from all over the continent. Professor Green was one of them.

The Australian, who had worked on plasma physics research in Germany, became the chief engineer on site and oversaw the design and construction. The model chosen is a tokamak, which uses a magnetic field to confine a plasma (hot ionized gas) inside a container. This plasma allows light elements to fuse together to obtain energy.

It was also designed to work with a mixture of deuterium and tritium (the radioactive elements of hydrogen) rather than just one, which proved to be an important decision. This has been confirmed to be the most efficient reaction for fusion reactors.

The world’s first experiment using this mixed fuel was conducted at JET in 1991. Higher energy yields were achieved in subsequent experiments, and the facility holds the world record for the highest energy produced from a fusion experiment – 59 megajoules (MJ) in five experiments – the second pulse.

Despite the record, the JET site faced numerous difficulties and delays, with experiments suspended for nearly a decade during internal structure replacements in the mid-2000s, according to JET senior development manager Fernanda Rimini. That’s what it means.

And the hope of producing enough energy to power homes is still far away. 59 MJ is only enough to boil about 60 kettles of water.

Joel Mailloux is the JET Science Program leader who will oversee the third round of deuterium and tritium experiments, which conclude on Saturday.

She said the main challenges they are focusing on are making the plasma more stable, distributing the power load and improving the materials inside the reactor to withstand the conditions. Ta.

Even when the experiment ends, scientists will still have much to learn from JET.

“Decommissioning involves analyzing what happened to the reactor. [reactor] The material and how it has changed. This will help us better maintain other fusion sites,” Ms Rimini said.

One of the facilities benefiting from JET’s research will be the new Iter reactor in southern France. It is the world’s largest fusion project, a consortium of many countries including the EU, Russia, the US and China, but a few weeks ago the UK government confirmed that the UK would not play a role.

“In line with the wishes of the UK’s fusion sector, the UK has decided to pursue a domestic fusion energy strategy instead of joining the EU’s Euratom programme,” the government said.

The UK Government has committed to spending £650m on the UK’s alternative fusion program between now and 2027. This includes a new prototype fusion energy plant called STEP in Nottinghamshire.

Paul Methven, UK Atomic Energy Agency’s STEP program director, told the BBC: “In an initiative like this we need to be very ambitious but also realistic.

“We’re working pretty hard for first operations in the early 2040s.”