Partial shutdown of units at France's Gravelines nuclear power plant due to jellyfish influx

French utility EDF announced on August 27 that the Gravelines nuclear power plant in northern France has taken emergency measures to shut down or reduce power output at some reactor units following a massive influx of jellyfish. An EDF spokesperson stated that since the night of August 26, more than 200 tonnes of jellyfish have accumulated near the filtration system of the plant's seawater pumping station. To ensure facility safety, the plant took preventive measures by completely shutting down 2 of its 6 reactor units. Meanwhile, 2 other units were operated at reduced power, and the remaining 2 units were already offline for maintenance and inspection reasons. This means that no unit at the Gravelines nuclear power plant is currently generating at full capacity...

2026-08-29

France's Gravelines Nuclear Power Plant Reports Multiple INES Level 0 Events

France's Gravelines nuclear power plant recently disclosed significant events reported to the French Nuclear Safety and Radiation Protection Authority (ASNR). The events cover safety, operations, and radiation protection, and were all rated as Level 0 on the International Nuclear and Radiological Event Scale (INES), i.e., below the scale threshold, with no actual impact on facility safety, personnel health, or the environment. In a generic safety event involving EDF's 900 MWe-class nuclear reactor units, EDF discovered during inspections at the Cruas nuclear power plant that certain commercially supplied electric servomechanisms had been installed in functional positions requiring higher qualification levels, K3 or K3ad. K3 corresponds to seismic requirements, while K3ad involves both seismic and harsh environmental conditions, including radiation environments. Subsequently, EDF conducted checks on related equipment at the Blayais, Chinon, Cruas, Dampierre, Gravelines, Saint-Laurent, and Tricastin nuclear power plants and confirmed that a batch of equipment had model suitability issues.

2026-08-27

France Approves Preliminary Works for EPR2 Project at Gravelines Nuclear Power Plant

The French government issued a decree on August 22, local time, approving French utility EDF to launch preliminary preparation works for two EPR2 pressurized water reactors at the Gravelines nuclear power plant, and granting it related environmental permits for site development. The plant currently operates six 900 MW units and is the largest nuclear power station in Western Europe by installed capacity. According to the decree, the approved works include construction of construction platforms and site facilities, relocation of the existing rail terminal, earthworks, foundation reinforcement, construction of waterproof containment structures, and construction access roads. The work also involves relocation of protected flora and fauna, construction of a public information center, and construction of some ancillary parking facilities. EDF said...

2026-08-25

Unit 3 of France's Gravelines Nuclear Power Plant Reconnected to Grid, Unit 4 Remains Shut Down

According to EDF on August 18, Unit 3 of the Gravelines Nuclear Power Plant in northern France was reconnected to the national grid at 3:55 a.m. local time on August 18. The unit had been automatically shut down at 7:43 p.m. on August 10 in accordance with established safety protection procedures due to a large influx of jellyfish into the seawater pump station filtration system. The Gravelines Nuclear Power Plant has a total of six units. On August 10, a large number of jellyfish entered the pump station used to draw seawater for cooling nuclear facilities, affecting equipment such as pre-filters and filter drums. In accordance with operating procedures, Units 3 and 4 were automatically shut down; the operating team also shut down Unit 2 and reduced Unit 1's power to 50% to adapt to changing site conditions. Unit 5 was...

2026-08-20

Heatwave and jellyfish influx into pump stations push French nuclear unit unavailability to 20.4%

The heatwave sweeping across multiple regions of France is impacting the country's electricity production. Several nuclear reactors operated by Électricité de France (EDF) have been shut down or derated due to environmental restrictions or external environmental factors, with the unavailability rate of affected units rising to 20.4% before 10:00 AM on August 12, marking a recent high. Of France's 57 nuclear reactors, 13 are currently affected. Among them, 8 units are fully shut down: Bugey Unit 3, Cattenom Unit 1, Chooz Units 1 and 2, Golfech Unit 2, and Gravelines Units 2, 3, and 4; another 5 units are operating below rated power, including Saint-Alban Unit 2, Tricastin Units 1 and 4...

2026-08-13

Jellyfish Blockage Forces Shutdown of French Nuclear Units; Experts Say Shutdown Demonstrates Effectiveness of Safety Systems

France's Gravelines Nuclear Power Plant recently shut down some of its units again after large numbers of jellyfish entered the water intake system. On August 11, reactors 2, 3, and 4 at the plant were forced to shut down due to blockage in the seawater cooling pump system, reactor 1 was reduced to half power operation, reactor 5 was under maintenance at the time, and only reactor 6 continued normal operation. EDF (Électricité de France) stated that the incident had no impact on nuclear safety, personnel, or the environment, and the affected units would be restarted in phases. Located in northern France, the Gravelines Nuclear Power Plant is one of the largest nuclear power plants in Western Europe. Similar situations have occurred before. In the 20...

2026-08-13

French nuclear fleet output drops to 59% of full capacity

On Wednesday, August 12, French nuclear reactors operated at 59% of full capacity, according to RTÉ grid data and Bloomberg calculations, down 1 percentage point from 60% on Tuesday, August 11. EDF, the world's largest nuclear power operator, currently has 34 reactors in operation with a total available capacity of 33,250 MW; France's 57 nuclear reactors normally supply more than two-thirds of the country's electricity. EDF recently halted power generation at the Gravelines 2 and Bugey 3 reactors, while extending the outage of the Gravelines 3 and 4 units and the Cattenom 4 reactor...

2026-08-13

Three units at France's Gravelines nuclear power plant automatically shut down due to jellyfish intrusion

French utility EDF recently stated on its website that three units at the Gravelines nuclear power plant in northern France automatically shut down after a large influx of jellyfish clogged the filtration system, triggering safety measures. The statement indicated that the incident occurred on August 10, 2026. Due to the jellyfish intrusion, three units at the Gravelines plant automatically shut down, while a fourth unit reduced its power output. The plant has a total of six reactors, of which the fifth reactor had already been shut down for planned maintenance, and the sixth reactor remained in operation. The Gravelines plant experienced a similar situation a year earlier, when a large number of jellyfish entered the relevant water intake and filtration systems, causing four reactors to automatically shut down...

2026-08-12