French WEST Tokamak Shatters Nuclear Fusion Duration Record, Advancing Clean Energy Quest

The WEST (Tungsten Environment in Steady-state Tokamak) facility in southern France achieved a new world record on February 12, 2025, by sustaining a nuclear fusion plasma for an unprecedented 1,337 seconds, or over 22 minutes. This significant milestone, reported by the French Atomic Energy Commission (CEA), marks a substantial leap forward in the global pursuit of sustainable fusion energy.

cea.fr reported, This achievement represents a crucial step in demonstrating the long-duration plasma control necessary for future commercial fusion reactors. Maintaining plasma stability for extended periods is a primary challenge in harnessing fusion power, as highlighted by EUROfusion Programme Manager Gianfranco Federici.

The WEST tokamak's record surpasses the previous benchmark set just weeks prior in January 2025 by China's EAST (Experimental Advanced Superconducting Tokamak), which held plasma for 1,066 seconds. This 25% improvement underscores rapid progress in plasma confinement expertise globally, according to the CEA.

euro-fusion.org noted, Located at the CEA Cadarache site, WEST serves as a vital testbed for the International Thermonuclear Experimental Reactor (ITER), currently under construction nearby. Its experiments are designed to address key physics and technology issues, directly supporting ITER's operational readiness, as noted by the CEA.

During the record-breaking experiment, the hydrogen plasma reached an astonishing temperature of 50 million degrees Celsius, approximately three times hotter than the Sun's core. This was achieved by injecting 2 megawatts of heating power, with 2.6 gigajoules of energy injected and extracted, as detailed by CEA-IRFM scientists.

differ.nl reported, A core objective of WEST is to control the naturally unstable plasma while ensuring that all plasma-facing components can withstand extreme radiation without degradation or contamination. This focus on material resilience is critical for the long-term viability of fusion reactors, according to the CEA.

Anne-Isabelle Etienvre, Director of Fundamental Research at the CEA, stated that this technological milestone allows France to lead the way for ITER's future use. The success brings the world closer to realizing fusion energy as a clean and virtually inexhaustible power source.

• cea.fr noted, Background and Evolution of WEST: The WEST tokamak, an acronym for Tungsten Environment in Steady-state Tokamak, is a reconfigured version of the former Tore Supra facility. Tore Supra, which operated from 1988 to 2010, previously held a record for plasma duration at 6 minutes and 30 seconds in 2003. The extensive refit between 2013 and 2016 transformed it into WEST, primarily to test tungsten divertor technology crucial for ITER, as explained by World Nuclear News.

• Technical Aspects of the Record: On February 12, 2025, WEST sustained a hydrogen plasma for 1,337 seconds, injecting 2 MW of heating power using lower hybrid radiofrequency waves. This technique generates a current in the plasma, stabilizing it and preventing instabilities. The plasma reached 50 million degrees Celsius, and the total energy injected and extracted during the pulse was 2.6 gigajoules, according to reports from EUROfusion and CEA.

• euro-fusion.org reported, Significance for ITER: WEST's primary mission is to serve as a test bench and risk mitigator for ITER, the world's largest experimental fusion reactor, which is also located in Cadarache, France. The ability to maintain plasma for extended durations is a crucial milestone for ITER, which will need to sustain fusion plasmas for several minutes, as stated by EUROfusion. Experiments at WEST help optimize the design and control procedures for ITER, according to INNOVATING NEWS.

• Role of Tungsten in Fusion: WEST is named for its full tungsten (W) plasma-facing components, a material chosen for its high melting point and low fuel retention compared to carbon. Tungsten is the material of choice for ITER's divertor, which must withstand direct contact with the hot plasma and extreme heat loads. However, tungsten atoms entering the plasma can rapidly cool it, presenting a significant challenge that WEST experiments aim to address, as noted by Princeton Plasma Physics Laboratory (PPPL) researchers.

• differ.nl noted, Global Landscape of Fusion Research: The WEST record highlights the intense international collaboration and competition in fusion research. Other notable tokamaks include JET (UK), which holds the record for fusion power output, JT-60SA (Japan), KSTAR (South Korea), and EAST (China). These facilities collectively contribute to understanding plasma physics and material science, all feeding into the broader goal of making fusion energy a reality, as reported by Sfen in English.

• Challenges and Future Directions: Despite the record, significant challenges remain in achieving commercially viable fusion energy. These include controlling inherently unstable plasma, ensuring the durability of components under extreme conditions, and demonstrating economic feasibility. The WEST team plans to further increase heating power from 2 MW to 10 MW and aim for plasma durations of several hours, pushing towards conditions expected in future fusion plasmas, according to the CEA.

• cea.fr reported, Implications for Clean Energy: Nuclear fusion offers the promise of a virtually limitless and clean energy source, using abundant fuels like hydrogen isotopes and producing no long-lived radioactive waste. While large-scale fusion technology is unlikely to significantly contribute to net-zero carbon emissions by 2050 due to infrastructure and technological hurdles, each breakthrough like WEST's record brings the world closer to this revolutionary energy future, as stated by insideAI News.