As part of the GEMINI 4.0 project (Horizon Europe/Euratom), a Summer School was held on 24-26.09.2024. It brought together 70 participants from Poland and Europe, Asia and Africa. They learned about the technology of high-temperature gas-cooled reactors (HTGRs) and, above all, their application for the generation of process heat between 300 and 550 degrees Celsius, electricity, low-temperature district heat, hydrogen, etc., the so-called polygeneration. High-temperature reactors are currently the most viable opportunity for the decarbonisation of the Polish and European chemical industry in need of high-temperature steam, which cannot be produced by the currently commonly used light-water reactors for power generation.

The speakers at the school were eminent European HTGR technology specialists, including dr Frederic Reitsma (IAEA), dr M. Fuetterer (JRC), dr Dominique Hittner, dr Michel Pasquet (Framatome, project coordinator), as well as Polish specialists from the Institute of Energy PIB, Synthos Green Energy company and local NCBJ representatives. Prof. Mariusz Dabrowski presented the advancement of the technical design of the Polish HTGR-POLA research reactor to be built in Świerk, and dr Józef Sobolewski presented the pan-European situation regarding the decarbonisation of industry in Poland and Europe.

During the school, attention was drawn to the advantages of HTGR technology, including its passively regulated safety systems governed by the laws of physics, such as the negative temperature coefficient of reactivity, the radiating of excess heat through heated graphite and the retention of fission products in the first shell of porous pyrolytic carbon. Also discussed were issues related to the design, systems and components of the reactor structure and equipment, reactor safety analyses, polygeneration, including steam and hydrogen production, as well as socio-economic aspects related to the implementation of this technology.

The GEMINI 4.0 project, led by the European association NC2I (Nuclear Cogeneration Industrial Initiative), aims to develop the concept of a 180 MW thermal HTGR industrial reactor for the needs of Poland and Europe and specified proposals for its applications in hard-to-decarbonise branches of the economy, with the very important aim of achieving Europe's climate goals. In parallel to this project, the NCBJ, in cooperation with the Japan Atomic Energy Agency and assisted by the Polish design company Energoprojekt Katowice (EPK), is finalising the basic design of the HTGR-POLA research and demonstration reactor of 30 MW thermal power to be built at the Świerk nuclear site, as the first stage of implementing HTGR technology in our country. The basic design consists of more than 3,000 pages of technical description contained in 18 volumes and several hundred models of reactor components.