Abstract: The invention relates to an inexpensively-/easily-decommissionable nuclear power plant, where a nuclear isle of one or more nuclear power-stations is installed in caverns, and further, side by side with them, a centre for characterising, treating and conditioning radioactive wastes and two repositories are installed in suitable caverns, with a final repository being adapted to store low-intermediate level nuclear wastes and a temporary repository being adapted to store spent fuel, high-level long-life radioactive materials and, in case, spare nuclear rods for reactor refueling.