Jellyfish, Extreme Weather Reduce French Nuclear Capacity; Romania Plant Shuts

Romania's state-owned nuclear power producer Nuclearelectrica plans to shut down its last working reactor on August 13 due to falling water levels on the Danube river.

The two reactors at Nuclearelectrica's Cernavoda power plant typically supply about a fifth of Romania's electricity. Romania has declared an energy emergency through August, taking measures such as dredging the channel and sinking rock-filled barges. Romanian naval forces also carried out a controlled underwater explosion on the riverbed last week to improve water flow to the plant's cooling systems.

In France, the country recorded a more than 20 percent shortfall in nuclear power production capacity on Wednesday, a record deficit. This was caused by environmentally related outages linked to drought, extreme heat, and a jellyfish invasion. Between 9:45 am and 10:00 am, EDF's nuclear fleet experienced a new peak in outages due to environmental constraints or external environmental causes.

Thirteen of EDF's 57 reactors were affected, with eight completely shut down and five operating at reduced power. Much of the lost generating capacity resulted from full or partial shutdowns at five of the six reactors at the Gravelines nuclear power plant. A swarm of jellyfish clogged pumps used to cool the units there. EDF reported around 100kg of jellyfish arrived on Saturday, increasing to several tens of tons by Monday.

This marks the second successive year a jellyfish swarm has shuttered reactors at Gravelines. EDF had installed cameras and deployed fishing boats to patrol the area after last year's incident. Fishing vessels now conduct preventive fishing operations 24 hours a day with three boats patrolling off the coast. Outside Gravelines, other reactor shutdowns or reductions are linked to extreme heat and droughts, which deprive plants of cooling water.

France uses nuclear power to generate around 70 percent of its electricity. Nicolas Goldberg, an energy expert at Colombus Consulting, states this situation does not pose short-term supply problems.