The facility is designed to store spent nuclear fuel that has been cooled for more than 15 years in the plant’s on-site spent fuel pools. The fuel will then be transferred into metal dry storage casks and placed inside a dedicated building. The facility will have a storage capacity of up to 960 fuel assemblies.
The structure, including its underground section, will measure approximately 30 meters in height, 50 meters in width, and 60 meters in depth. The dry storage casks will feature multilayered metal structures and be passively cooled by natural airflow.
Dry storage technology—which requires neither water nor external power for cooling—is considered highly resilient to natural disasters such as earthquakes and tsunamis. Its adoption is increasing both in Japan and abroad.
Regarding the Genkai facility, Kyushu Electric Power applied for a reactor installation modification license in January 2019 and received approval in April 2021. The company subsequently submitted its design and construction plan in June 2024, and final approval was granted on April 30 of this year, paving the way for the start of construction.
