The extraordinary heatwave this summer is pushing nuclear power plants into crisis, forcing shutdowns because reactor cooling has become impossible.
The heatwave that has swept Europe from north to south in recent weeks has caused the shutdown of several nuclear power plants in France, Germany and Sweden due to water scarcity and high river and sea temperatures, as these waters are used to cool the reactors. Added to this is the damage to aquatic flora and fauna. After using the water for cooling purposes, the plants discharge it back into watercourses or the sea at even higher temperatures, causing a further rise in temperatures that is leading to mass fish die-offs.
In France, no fewer than four nuclear reactors were shut down due to the impossibility of activating adequate cooling without placing further stress on the ecosystems of certain rivers. EDF, France's largest energy producer and distributor, decided to shut down one reactor at the Fessenheim power plant in Alsace, one at Saint-Alban near Gravelines, in Nord-Pas-de-Calais, and two more at the Bugey power plant, 25 kilometres east of Lyon and just over 150 from the Italian border. The latter is remembered for the incident that occurred in June of the previous year when, during maintenance work, the malfunction of a valve led to a pressure build-up in the reactor heat removal system, causing a venting that, fortunately, did not result in any release of radioactivity into the air, despite the considerable alarm it had generated.
Like their French counterparts, the authorities in Germany have also decided to adopt extraordinary measures by slowing energy production at nuclear power plants. The reason is always the same: if plant temperatures were to rise too high, the intake of cooling water would become impossible, opening up catastrophic scenarios. As a precautionary measure, on the upper Rhine, energy producer Karlsruhe EnBW reduced output at the Philippsburg nuclear power plant to between 2 and 10 per cent. The same fate could befall the Neckarwestheim plant and the Brokdorf plant.
The question of how to cool nuclear power plants when the temperature of the water used under normal conditions exceeds the critical threshold is an issue affecting Sweden too, despite its use of seawater. The unrelenting heat has brought water temperatures to around 25 degrees, a level far too high, prompting the authorities to suspend operations at the Ringhals nuclear power plant, the most powerful in the country. A rare event, yet one that nonetheless highlights the fragility of nuclear facilities which, while on the one hand guaranteeing large quantities of clean energy, on the other are constantly having to contend with situations that risk triggering catastrophic accidents.