The Applied Superconductivity Center at Seoul National University, led by Professor Seungyong Hahn of the Department of Electrical and Computer Engineering and the Electric Power Research Institute, announced that it has signed a three-phase joint research agreement worth £10.17 million (approximately KRW 20 billion) with UK Industrial Fusion Solutions (UKIFS), a wholly owned subsidiary of the United Kingdom Atomic Energy Authority (UKAEA) that leads the Spherical Tokamak for Energy Production (STEP) program. STEP is a major strategic national infrastructure project led by UKAEA. It aims to build a 100 MW-class commercial fusion power plant by the early 2040s, capable of supplying electricity to more than 200,000 four-person households. In June 2025, the UK government confirmed West Burton in Nottinghamshire as the construction site and announced an investment of £2.5 billion (approximately KRW 4.9 trillion) over five years to advance fusion energy development.* * Source: Major funding milestone for world-first prototype fusion plant - STEP Fusion The Applied Superconductivity Center and UKAEA laid the groundwork for this project through Phase 1 and Phase 2 joint research conducted over approximately two years, beginning in June 2024. In Phase 1, the team designed and fabricated a 3.6-meter-class, high-current, high-temperature superconducting cable prototype, achieving world-class performance and reliability. In Phase 2, the team developed manufacturing equipment for long-length cable production applicable to actual fusion magnets. In particular, the fabricated cable prototype underwent performance testing in July 2025 at the SULTAN test facility under the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. As a result, the prototype achieved the facility’s operational limits of an external magnetic field of 10.9 T and an operating current of 91 kA, corresponding to an electromagnetic force* of 100 tons per meter. The cable also demonstrated high reliability, with no performance degradation observed after more than 1,400 repeated charge-discharge cycles and intentional quench accident tests. This represents an unprecedented achievement in the field of high-temperature superconducting cables since the SULTAN ((German) SUpraLeiter Test ANlage) facility began operation in 1992. Furthermore, key performance indicators, including temperature-dependent critical current predictions, matched the values predicted in advance by analysis software independently developed by the SNU research team, demonstrating the precision of the team’s design technology. * Electromagnetic force: the product of current, perpendicular magnetic field, and length In Phase 2 of the research collaboration, which began in July 2025, the team moved beyond the conventional manual fabrication method for high-temperature superconducting cables and developed dedicated manufacturing equipment for long-length cable production required for future fusion magnets. In the newly agreed Phase 3 collaboration, the goal is to fabricate a 3-meter-scale prototype of a Toroidal Field Model Coil (TFMC) for fusion applications. This Phase 3 collaboration is expected to serve as an important turning point in raising the technology readiness level (TRL) of STEP’s high-temperature superconducting magnet technology, as the scope of cooperation has significantly expanded beyond the laboratory scale to long-length cable production using the team’s self-developed specialized manufacturing equipment and ultimately to the fabrication of a TFMC prototype. Behind these achievements is the work of the Project for Research and Innovation in Superconducting Magnet (PRISM), also known as the High-Temperature Superconducting Magnet Core Technology Research Group. PRISM is supported by the National Research Foundation of Korea under the Ministry of Science and ICT and led by the Applied Superconductivity Center at Seoul National University. The group is headed by Sangjin Lee, visiting professor in the ECE Department at SNU. Launched in 2022, PRISM carries out the High-Temperature Superconducting Magnet Technology Development Project from April 2022 to December 2026, under the vision of “the nation as one research institute and one university.” With a total budget of KRW 46.4 billion over five years, the project brings together 27 industry, university, and research institutions and more than 220 researchers. The group has systematized high-temperature superconducting magnets, which can be applied across a wide range of manufacturing industries, into four major configurations and seven key technologies for the first time in the world, and is developing core original technologies for mass production and high-end commercialization. Based on the results of the ongoing prototype development, the research team is currently discussing plans to expand the number of fusion model magnet prototypes produced and to participate in the fabrication of the final STEP model magnet. This marks the first case in which Korean technology could be applied to a core system of an actual fusion reactor, going beyond the simple supply of components. The collaboration is expected to open opportunities for Korean researchers and deep-tech companies to enter various advanced industrial fields, including future high-temperature-superconductivity-based fusion reactor construction projects, as well as biotechnology and materials, medicine, national defense, advanced science, and future mobility. Ultimately, the results of Korea’s original high-temperature superconducting technology development are expected to become a key foundation not only for the achievements of individual research institutions, but also for the expansion of the broader domestic industrial ecosystem into the global market and for securing national strategic technological competitiveness. For this joint research with UKIFS, SNU formed a response team together with PRISM participating companies PowerNix Co., Ltd. (CEO Kwanghee Yun) and Standard Magnet Inc. (CEO Jaemin Kim). The team worked closely together throughout the entire process of designing, fabricating, and evaluating the cable prototype, producing excellent outcomes. These achievements are linked to the Ministry of Science and ICT’s “Deep Science Startup Activation Support Program” and are now leading to the establishment of a domestic company specializing in high-temperature superconducting systems for fusion energy, centered on the response team. This collaboration is also being carried out as part of the Seoul National University Energy Initiative (SNU-EI), led by Professor Sung Jae Kim of the ECE Department. Accordingly, beyond the development of high-temperature superconducting magnet technology for fusion power, which is expected to become one pillar of future electricity production, the project is expected to lay the groundwork for collaboration with energy experts in the production division under SNU-EI. Through this collaboration, the team aims to examine key enabling technologies and technological limitations that can accelerate the practical commercialization of fusion energy, while expanding into various forms of technical cooperation and derivative projects. ▲ Figure 1. (Left) Schematic of the STEP fusion reactor being developed by the UKAEA (Source: https://step.ukaea.uk/) (Right) Configuration of an HTS magnet system for fusion applications: (1) wire; (2) cable; (3) magnet; (4) system. The UKAEA-SNU joint research agreement is expected to expand from cables to magnets and systems. (Source: Wire - https://sunam2004.tradekorea.com/main.do; Cable - provided by SNU; Magnet - K. J. Chung et al., Design and Fabrication of VEST at SNU, presented at 16th International Workshop on Spherical Torus, Sep. 27-30, 2011.; System - https://actu.epfl.ch/news/welcome-mast-upgrade-a-new-fusion-device/) ▲ Figure 2. (Left) Prototype of dedicated manufacturing equipment for long-length cable production developed at SNU (Right) Installation of a 12-meter-long facility based on the prototype ▲ Figure 3. (Left) The SULTAN test facility managed by the Swiss Plasma Center (SPC) under EPFL in Switzerland. The facility outlined by the light-green frame on the right is SULTAN. (Source: https://www.epfl.ch/research/domains/swiss-plasma-center/research/superconductivity/page-97675-en-html/) (Center) Photo of the HTS cable tested at the SULTAN facility. The cable achieved the facility’s operational limits of an external magnetic field of 10.9 T and an operating current of 91 kA, corresponding to an electromagnetic force of 100 tons per meter. (Right) Data recorded when the cable reached its maximum current, showing representative voltage (navy) and current (blue) in the high-field region of 10.9 T. The cable reached 91 kA at around 20 K. ▲ Figure 4. (Left) Equipment for fabricating a HTS cable former (Right) Photo of the fabricated 10-meter-class long-length cable former [Contact] - Professor Seungyong Hahn / 02-880-1495 / hahnsy@snu.ac.kr - Integrated M.S.-Ph.D. Candidate Dongwoo Lee / imdwl0830@snu.ac.kr [Reference] - STEP Website: https://stepfusion.com/uk-fusion-energy-strengthens-korea-partnership/ - College of Engineering Notice Board: https://eng.snu.ac.kr/communication/promotion/news?md=v&bbsidx=8075 - Maeil Business Newspaper Article: https://n.news.naver.com/article/009/0005682928?sid=105 Source: https://ece.snu.ac.kr/ece/news?md=v&bbsidx=57756 Translated by: Changhoon Kang, English Editor of the Department of Electrical and Computer Engineering, changhoon27@snu.ac.kr...
May 21, 2026