Nuclear Decommissioning Plan and Waste Management Overview

The government has unveiled a roadmap to dismantle nuclear power plants and manage radioactive waste, introducing the Seventh General Radioactive Waste Plan. The document confirms the planned regular shutdown of seven reactors that remained active between 2027 and 2035, a course already agreed with plant operators in March 2019.

Two moments from the dismantling of the Swedish factory | GDES

Under the schedule, the Almaraz I plant in Extremadura will halt in November 2027. It will be followed by Almaraz II in October 2028, Ascó I in October 2030, Cofrentes in Valencia, Ascó in Tarragona in November 2030, Vandellós II in February 2035, and Trillo in Guadalajara in May 2035.

The plan anticipates dismantling nuclear facilities three years after final shutdown, with Vandellós I excluded since it is already in progress and its final phase will run from 2030. It also outlines a central repository for spent fuel and high‑level waste as an alternative to the currently blocked or seven decentralized temporary depots at each nuclear plant. Spent waste will be stored temporarily for sixty years while the ultimate solution remains a Deep Geological Repository where waste would stay for thousands of years at depths ranging from 500 meters to about one kilometer. Finland is highlighted as the first country to construct such a facility.

Countdown to big blackout

The expense of shutting down the nuclear cycle and safeguarding waste could reach up to 26.5 billion euros. While the government remains firm on the timetable, some experts argue that Spain’s reliance on other energy sources, like natural gas, creates pressure to rethink plant closures, a factor underscored by the Ukraine conflict. This pressure has driven electricity costs higher in many cases.

Countdown to big blackout

Since 1984, Enresa has operated as a public company charged with managing radioactive waste and dismantling nuclear facilities. The one facility largely dismantled to date is José Cabrera in Almonacid de Zorita (Guadalajara).

Enresa notes that the most complex phase involves handling the active components of the plant, especially the reactor internals where fission reactions initiate, proceed, and are controlled, and the reactor itself containing these components. Together with spent fuel, these elements represent the most active parts of a decommissioned plant and demand highly specialized work.

Boat

The Valencia‑based company GDES, employing about 1,700 people and reporting a turnover near 124.5 million in 2021, runs a division dedicated to nuclear dismantling. The firm completed post‑segmentation work on Barsebäck‑1 in Sweden and achieved a milestone by dismantling a 600 MW reactor for the first time. José Tomás Ruiz, Vice President of GDES and Director of Nuclear Services, explains that this is an industrial process carried out in a challenging environment due to radiological conditions, with every detail planned well in advance. Ruiz notes that dismantling a power plant requires planning years ahead and often begins before the plant’s operation ends.

three years to start

Enresa describes that work begins three years after the shutoff, as spent fuel must cool in cooling pools. Decommissioning itself can take up to a decade. Dismantling goes beyond mere demolition; it involves disassembling large equipment. Radiological limits require underwater cutting using robotic tools and precise techniques. Materials must be managed to minimize radioactive waste. All steps are supervised by nuclear safety authorities to ensure safe conditions and environmental protection throughout.

Spain initially chose to reprocess waste from Vandellós I, José Cabrera, and Santa María de Garoña in France and the United Kingdom. In 1982 this approach was halted, and each Spanish plant began storing spent fuel in its own pools. The reprocessing waste, depending on contracts, may or may not be returned to Spain. Today, waste from spent fuel reprocessing from Vandellós remains in France and must be returned.

The proposed Central Temporary Depot in Villar de las Cañas, Cuenca, was abandoned two years ago amid local opposition to a nuclear cemetery. Administrators are now considering either an ATC elsewhere or seven Distributed Temporary Depots next to each of Spain’s seven nuclear plants.

For final disposal of spent fuel and high‑level waste, the international consensus supports deep storage in underground facilities within stable geological formations. Enresa explains that geological storage can occur in clay, salt, and hard rock such as granite, gneiss, basalt, or tuff. The emplacement depth depends on the chosen formation and its insulating properties, with hard rock typically needing a depth of 500 to 1,000 meters.

Citizen consensus helped shape Finland’s Deep Geological Repository project, with the Onkalo facility on Olkiluoto Island reaching a depth of about 450 meters and a vast network of tunnels. The Finnish approach, built over decades, aims to provide a lasting solution for spent fuel, with confidence in its safety for the long term.

The drive to close the nuclear cycle began at a moment when concerns rose about Spain’s readiness for a major blackout. Alberto Escrivá, a professor of Nuclear Engineering at the Polytechnic University of Valencia, argues that a stable and necessary energy source is essential until renewable capacity can meet demand. The Ukraine conflict highlighted gas dependency as a fallback, though it remains unclear whether society can do without nuclear power without new technologies. Energy firms like Iberdrola favor renewables but face high maintenance costs, while others see extended plant lifespans as a practical bridge toward a lower‑carbon future.