A massive influx of jellyfish has led to the partial shutdown of a nuclear reactor in northern France.
Gravelines, one of the region’s biggest nuclear power stations located between Dunkirk and Calais, saw two of its six units pulled offline on Wednesday and Thursday as jellyfish clogged the seawater cooling filters. A third unit had been shut since 10 August for the same reason, while a fourth paused for inspection. EDF confirms that units three, four and six are now offline, and units one and two operate at a reduced capacity as a precaution.
Each of Gravelines’ units generates about 900 megawatts, and the plant relies on a canal connecting to the North Sea for cooling. Rising temperatures elevate surface plankton, attracting jellyfish en masse, a phenomenon most pronounced in summer months.
To counter this, EDF has partnered with fishermen who harvest and release jellyfish offshore, a strategy already tested elsewhere. Similar troubles hit Torness in Scotland in 2011 and Sweden’s Oskarshamn plant in 2013, marking the event as an uncommon but real threat to nuclear safety.
As climate change accelerates plankton blooms, engineers anticipate that marine life will increasingly challenge the integrity of cooling systems at nuclear and heating plants alike. Proactive filtration upgrades and real‑time marine monitoring are on the agenda to avert future shutdowns.
