The walls of the Joint European Torus fusion reactor are lined with the same materials as ITER, a much larger fusion reactor under construction.

©EUROfusion (CC BY)

Last-minute deal grants European money to U.K.-based fusion reactor

At the eleventh hour, the European Union has agreed to fund Europe’s premier fusion research facility in the United Kingdom—even if the United Kingdom leaves the European Union early next month. The decision to provide €100 million to keep the Joint European Torus (JET) running in 2019 and 2020 will come as a relief both to fusion researchers building the much larger ITER reactor near Cadarache in France and the 500 JET staff working in Culham, near Oxford, U.K.

“Now we have some certainty over JET,” says Ian Chapman, director of the Culham Centre for Fusion Energy (CCFE), which hosts the JET. But the agreement does not guarantee the JET’s future beyond the end of next year, nor does it ensure that U.K. scientists will be able to participate in European fusion research programs.

Until the $25 billion ITER is finished in 2025, the JET is the largest fusion reactor in the world. In 2011, the interior surface of its reactor vessel was relined with the same material ITER will use, tungsten and beryllium, making the JET the best simulator for understanding the behavior of its giant cousin.

The JET was built in the 1970s and ’80s as part of Euratom, a European agreement governing nuclear research. In recent years, CCFE has been managing the JET on behalf of Euratom. But Brexit, the threat of the United Kingdom’s departure from the European Union, has clouded the reactor’s future. The U.K. government has said it also intends to withdraw from Euratom, a separate treaty than the one that governs the European Union. The U.K. government wishes to become an associate member of Euratom, a position that Switzerland holds, so it can continue to participate in research and training. But that agreement cannot be negotiated until after Brexit, which could come as soon as 12 April—or not. With the United Kingdom’s future relationship with Europe still a matter of heated debate, so is its partnership with Euratom.

CCFE was contracted to manage the JET until the end of 2018. The agreement announced today keeps the JET running until the end of 2020 with €100 million from Euratom. “There is no Brexit clause,” Chapman says, so whatever happens in the coming weeks, the JET is safe for now.

The JET is essential for ITER preparations, not just because of its inner wall, but because it is the only reactor in the world equipped to run with the same sort of fuel ITER will use, a mixture of deuterium and tritium, both isotopes of hydrogen. In 2020, researchers hope to study how this fuel behaves in the revamped the JET to make it easier to get ITER up to full performance. “It’s a really important experiment,” Chapman says. “We need to demonstrate that we can get a high-performance plasma with a tungsten-beryllium wall. It’s never been done with deuterium-tritium before.”

Beyond 2020, the JET’s future is uncertain, even aside from Brexit. Euratom and ITER would both like to keep the JET running to carry out more studies up until 2024. Ultimately,  that depends on it winning funding in the European Union’s next funding cycle, which begins in 2021. But a question still hangs over what sort of relationship the United Kingdom will have with Euratom by that time. “That uncertainty has not gone away,” Chapman says.