Countdown to big blackout

According to the schedule, the Almaraz I plant (Extremadura) will be stopped in November 2027. It will be followed by Almaraz II in October 2028, Ascó I (Tarragona) in October 2030, Cofrentes (Valencia), Ascó (Tarragona) in November 2030. ) in September 2032, Vandellós II in February 2035 and Trillo (Guadalajara) in May 2035.

The plan envisages dismantling of nuclear facilities three years after the definitive cessation, with the exception of Vandellós I, which is currently in the process and whose final phase will take place from 2030. central repository (ATC) for spent fuel and high-level waste – an alternative to the currently blocked – or seven decentralized temporary warehouses (ATDs) at nuclear power plant facilities. The waste will be stored “temporarily” for sixty years, while the final solution consists of a Deep Geological Repository (AGP) where the waste will remain for thousands of years at a depth of between 500 meters and one kilometer. Finland is the first country in the world to build such a warehouse.

The cost of shutting down the nuclear switch and storing waste safely could be up to 26,500m euros. Although the government is clear that there is no turning back on this calendar, some experts argue that the shutdown of nuclear power plants should be reconsidered because of Spain’s dependence on other energy sources such as gas, as demonstrated by the war in Ukraine. This has increased the cost of electricity many times over.

In 1984, the State established Enresa, a public company whose mission is responsible for the management of radioactive waste and the dismantling of nuclear facilities. The only facility that has so far been almost completely dismantled is José Cabrera’s facility in Almonacid de Zorita (Guadalajara).

Enresa sources explain that the most complex process is the “management of the active parts of the plant, particularly the internal elements of the reactor (where nuclear fission chain reactions are initiated, maintained and controlled) and the ship itself containing them. These, along with spent fuel, are the most active parts of a discontinued nuclear power plant. These are complex tasks.”

Boat

The Valencian company GDES (1,700 workers and a total turnover of 124.5 million in 2021) has a branch dedicated to the dismantling of nuclear power plants. The firm successfully completed post-segmentation work on the ship of the Swedish Barsebäck-1 nuclear power plant and reached a career milestone by dismantling a 600 MW reactor for the first time. José Tomás Ruiz, Vice President of GDES and Director of Nuclear Services, points out that this is an industrial process that is carried out in a complex environment due to the radiological conditions involved and everything has to be planned down to the smallest detail. . “It is important to understand that the dismantling of a power plant was planned years in advance and indeed began long before the operation ended,” Ruiz said.

three years to start

According to Enresa, work begins three years after the cut, as spent fuel must be cooled in the facility’s pools. Decommissioning itself can take up to ten years. “Dismantling is not just the demolition of buildings. It is a process that requires disassembly of large equipment. Due to radiological limitations, very sophisticated underwater cutting techniques must be employed using robotic equipment and other more or less surgical methods. In addition, materials need to be managed in a way that reduces radioactive waste. All these processes are overseen by nuclear safety authorities and require very complex procedures to ensure that work is carried out in safe conditions and that the environment is protected at all times,” says GDES vice president.

Spain initially chose to reprocess the waste from the first nuclear power plants (Vandellós I, José Cabrera and Santa María de Garoña in Burgos) at plants in France and the United Kingdom. In 1982, this practice was abolished and it was decided that each Spanish factory would temporarily store spent fuel (uranium) in its own pools. As a result of the first strategy, radioactive reprocessing waste was obtained, which, depending on the contracts, should or should not be returned to Spain. Currently, radioactive waste from spent fuel reprocessing from the remaining Vandellós nuclear power plant in France needs to be returned to the country.

The workaround for spent uranium was to be the planned Central Temporary Depot (ATC) in Villar de las Cañas in the municipality of Cuenca, but two years ago the Government rejected this location for a nuclear cemetery. The main problem is that the citizen refuses such warehouses. In this context, the Administrator is now considering two alternatives: an ATC elsewhere or seven Distributed Temporary Depots (ATDs) next to each of the seven Spanish nuclear power plants.

For the final disposal of spent fuel and high-level waste, the most appropriate and safe solution accepted by the international community is deep storage in underground engineering facilities within stable geological formations. According to Enresa, “Geological storage can be carried out in different geological formations, the best studied rock types are clay, salt and hard igneous, metamorphic or igneous rocks such as granite, gneiss, basalt or tuff”. The depth at which the tank should be placed depends largely on the type of formation chosen and the insulating capacity of the above formations. The general design depth for hard rock emplacement is between 500 and 1,000 meters.

Citizen consensus was key in the construction of the Finnish Deep Geological Repository (AGP), according to industry employers Foro Nuclear. The Onkalo depot on Olkiluoto Island, with a depth of about 450 meters and more than 70 kilometers of tunnels and wells, will store spent fuel from the country’s nuclear reactors. Infrastructure evolved from a decision made 40 years ago to provide a definitive solution to the waste problem. The Scandinavian country is confident that the nuclear burial will last at least 100,000 years.

The race to close the nuclear park began at a time when warnings were rising that Spain was not yet ready for the big blackout. Alberto Escrivá, Professor of Nuclear Engineering at the Polytechnic University of Valencia, argues that «until a large generation of renewable energy can be developed, it is a stable and necessary source of energy. The conflict in Ukraine showed how dependent we are on gas as a backup resource. It is not clear that we can do without nuclear without a new technology. The analyst at energy consultancy Grupo ASE Rubén Hernández agrees with Escrivá that it is necessary to extend the useful life of power plants because of their dependence on gas. However, energy companies like Iberdrola are not in favor of extension due to high maintenance costs and have stepped up their commitment to renewable energy.