Slovenia's leading research institution, the Jožef Stefan Institute (IJS) has officially launched a new facility at its TRIGA nuclear research reactor meant to advance fusion energy technology. The aim is to study how and why intense radiation occurs during the cooling of fusion reactors so as to enable a safer environment for research and improved reactor performance.

The KATANA water activation loop experimental facility that will help recreate conditions similar to those in fusion reactors was launched on 3 June with an event at the research reactor in Dol pri Ljubljani, just east of the Slovenian capital.

Luka Snoj, head of the reactor physics department and TRIGA reactor manager at IJS, hailed fusion energy as a potential new low-carbon energy source that can play a crucial role in combating climate change and environmental pollution from fossil fuels.

"Fusion is the process that powers stars, including the Sun, and is a source of immense energy. All the energy we have on Earth actually comes from the Sun. It drives the wind, enables solar and hydropower plants to function. We now want to recreate the processes happening inside the Sun here on Earth and generate fusion energy based on that," he explained.

He stressed that fusion on Earth has already been proven possible. The new ITER fusion reactor currently under construction in southern France, the largest international project in fusion energy, now aims to achieve higher fusion power output.

One challenge for future fusion reactors is their cooling systems. These will be cooled by water, which will become highly radioactive due to exposure to neutron radiation from the reactor, causing radiation around it. Although this radiation will be short-lived, it will still affect how long researchers can remain in its vicinity, and nearby electronic equipment will also be exposed, Snoj warned.

To better understand these phenomena, the European fusion consortium EUROfusion is developing simulation tools to calculate such radiation levels. However, these tools need to be validated through experiments. Therefore, at the TRIGA reactor, IJS has established the KATANA water activation loop experimental facility to recreate conditions similar to those in fusion reactors.

The purpose is to study radiation doses around the water cooling loop to better comprehend the processes causing water radioactivity during fusion reactor cooling, thus ensuring a safer environment for researchers and ultimately improving reactor efficiency, said Snoj, who led the facility's construction.

EUROfusion programme director Ambrogio Fasoli described the facility's launch as a major step forward in fusion progress in Europe and worldwide. Creating fusion energy is extremely difficult, so it's crucial that we work together, pooling our infrastructure and knowledge, he said.

The three-year development and construction of the facility, which cost nearly €1 million, were co-financed by EUROfusion and the Slovenian Research Agency.

Completed in early 2024, the facility is already licensed, successfully launched, and conducting initial test measurements. "First results indicate the irradiation facility is operating as expected," Snoj said.