Utility EdF last night curtailed about 3.1GW or just over half of France's 5.4GW Gravelines nuclear reactor — made up of six 900MW reactors — in response to a huge influx of jellyfish, increasing to 3.6GW on Tuesday evening.
EdF first automatically shut down units 3 and 4, followed by a unit 2 shutdown and a curtailment by half of unit 1, the utility said today.
Units 3 and 4 left the grid just before 20:00 local time on Monday, while unit 2 followed with a full-capacity outage at 22:30. Unit 1 began reduced operations at 430MW of capacity from 21:00, according to the utility's unavailability ticker.
Meanwhile, unit 5 was already off line for maintenance until 8 December, while unit 6 will be reduced to 500MW of capacity as of 16:30 today until 10:00 on Wednesday, according to a Remit notice published this afternoon.
The curtailments — excluding the partial reduction at unit 6 — equate to a 3.13GW or 58pc reduction in Gravelines' total plant capacity. Including the unit 6 curtailment, total reductions were at 3.63GW, or 67pc of the reactor's entire capacity.
The curtailments at units 1 and 2 are currently scheduled to last until Wednesday at 23:00, while units 3 and 4 are set to return to the grid at 23:00 on 16 and 19 August, respectively.
User-reported jellyfish weather service Meduseo on Monday reported an increase to 75 from 0 on its jellyfish density evolution chart at the Gravelines beach, next to the plant in northern France.
The recorded global average sea surface temperature last month was the highest for any July on record at 20.96°C, data from EU earth-monitoring programme Copernicus show.
And curtailed output from France's nuclear reactors so far this summer is nearing 5TWh due to heat and drought, having impacted 30pc of the fleet since restrictions began on 22 June. July was the hottest month ever recorded, according to state weather agency Meteo France, and one of the driest, with river flows and soil moisture at historic lows.
On this day a year ago, EdF disconnected four 910MW units at Gravelines after finding jellyfish in filtering drums at the reactor's pumping stations.
