The Japan Atomic Energy Agency (JAEA) is embarking on an innovative project to produce clean hydrogen using heat from a high-temperature gas-cooled nuclear reactor located at the Oarai Nuclear Engineering Institute in Ibaraki prefecture, Japan. By applying to connect a hydrogen production facility to its high-temperature test reactor, JAEA aims to decarbonize industries such as steelmaking and chemicals. The approval of this project could establish high-temperature gas-cooled reactor technology as a viable method for low-carbon hydrogen production, pioneering the world's first large-scale use of such reactors for hydrogen generation. Utilizing thermochemical water splitting, the process will leverage heat up to 950°C from the test reactor to split water into hydrogen and oxygen, ensuring emissions-free hydrogen production. JAEA targets to commence hydrogen production by 2030, pending regulatory consent, and plans for a complete demonstration reactor in the mid-2030s. Although specific hydrogen output volumes are undisclosed, the technology's capability to produce larger quantities of hydrogen due to higher outlet temperatures is promising. The agency will install the hydrogen production facility adjacent to the test reactor to facilitate the transfer of high-temperature heat through underground piping. Additionally, JAEA is exploring methods to eliminate CO2 emissions from auxiliary systems, strengthening the environmental benefits of the project. The advancement of high-temperature gas-cooled reactors in hydrogen production is anticipated to revolutionize the sector by providing a sustainable solution for low-carbon hydrogen, aligning with global efforts towards emissions reduction and energy innovation.