Nuclear waste management is one of the most contentious issues in the Spanish energy sector, from environmental, economic, and political perspectives. In addition to the usual debates about the closure and future of nuclear power plants, a legal battle has now erupted between the country's largest electricity companies and the government over an increase in the tax levied for the management and storage of this hazardous waste. Meanwhile, in international waters off the coast of Galicia, an investigation is underway into the legacy of decades of radioactive waste dumping in the northeastern Atlantic, which could have unknown effects on the marine ecosystem.
The conflict with the electricity companies revolves around the 30% increase in the so-called "Enresa tax," which finances the management and decommissioning of nuclear power plants. Endesa and Iberdrola, the main owners of Spain's nuclear fleet, have filed formal claims and lawsuits against the State, Enresa, and the Nuclear Safety Council. In total, they are seeking €778 million in compensation , motivated by the unilateral tax increase approved by the government in 2023. According to the companies, the protocol for the orderly closure of the plants, signed in 2019, stipulated that the increase could not exceed 20% of the tariff then in effect.
Why did the rate go up and what does it consist of?
The revision of the fee, which has increased from €7,98 to €10,36 per megawatt-hour (MWh), is, according to the government, a response to the need to cover the high costs associated with nuclear decommissioning and waste management in Spain. The fund managed by Enresa finances all related activities, and now, instead of a centralized storage facility, the government is opting to build seven temporary storage facilities at the sites of the nuclear power plants themselves, which complicates logistics and increases the cost of the process.
The companies consider the price increase a breach of the 2019 agreement and fear that the lack of profitability and the tax burden will worsen the viability of nuclear power plants, especially in the current context dominated by renewable energies. They have resorted to all available legal avenues , from claims for damages (Endesa) to administrative litigation (Iberdrola), in addition to challenging the new national waste plan and recent regulatory changes.
Impact of nuclear waste on the sea
While the debate over the economic cost plays out in the courts and offices, the environmental problem of nuclear waste remains. An international team led by the French National Centre for Scientific Research (CNRS), with the participation of Spanish experts, has launched a research operation in the Atlantic to locate and analyze waste deposited between 1940 and 1980, some 600 kilometers off the Galician coast.
More than 2.000 radioactive barrels have already been identified in an area that could hold more than 200.000. Using underwater robots like UlyX and advanced sonar techniques, scientists are mapping the area and collecting samples of water, sediment, and fish to measure potential radioactivity and its effects.
According to initial data provided by geologist Javier EscartÃn, one of the project coordinators, the levels of radioactivity currently detected are not cause for concern . Although the exact composition of the drums remains unknown, they are suspected to contain laboratory materials and low- or intermediate-level radioactive waste. The presence of these spills, reported since the late 80s, underscores the importance of regularly monitoring their potential impacts on marine biodiversity.
Spain and the repatriation of waste from France
One of the most notorious cases of nuclear waste management involves the waste from the Vandellós I nuclear power plant , which was shut down in 1989. Following an accident and its abrupt closure, some of the spent fuel was sent to France for storage and reprocessing. Due to delays in the construction of permanent storage facilities in Spain, the country has been paying France millions of euros in penalties every day for not yet repatriating this material. The penalties reached over €87.000 per day, although after a recent agreement, the figure will decrease slightly until 2026. The schedule anticipates the return of the waste in 2028, provided that the Vandellós I Temporary Storage Facility is operational as a precursor to the Deep Geological Repository, which is expected to open in 2073.
The official position and the future of nuclear power
The Ministry for Ecological Transition maintains that the "polluter pays" principle must prevail: electricity companies must bear the full cost of managing nuclear waste, without passing these costs on to consumers. Any request to extend the operational life of nuclear power plants will only be considered if safety and electricity supply are guaranteed, and if no additional burden is placed on citizens. Although Endesa and Iberdrola have submitted proposals to postpone plant closures, unanimity among all owners is required for any changes, and there is currently no consensus among the affected companies.
Furthermore, the legal pressure from electricity companies comes at a time of declining profitability for nuclear energy compared to renewable technologies, with specific taxes on production and waste treatment that make net costs per megawatt hour significantly higher than in other European countries.
Nuclear waste management continues to pose a major challenge for Spain, whether due to economic disputes between the state and electricity companies, the practical problems of storing and repatriating waste, or the need to monitor the environmental impact of historical discharges into the sea. Balancing safety, economic viability, regulatory compliance, and environmental impact is increasingly difficult to manage, in a context where the energy transition and environmental protection are more prominent than ever in public and political debate.
