With summer temperatures across northern Europe already rising, France may be forced into a repeat of 2003 when the country was faced with the shutdown of parts of its nuclear generation fleet after river water supply dropped to levels that threatened cooling water supplies and temperatures rose to record highs.

With 58 reactors that supply around 80% of the country’s energy, Electricit√© de France (EdF) is already calling for consumers to cut demand and has been on the verge of disconnecting the Tricastin plant, located in southeast France on the Rhone, when discharge water temperature exceeded 25oC, the maximum allowed under environmental laws.

In addition, reactors must also be shut down if the internal temperature rises above 50oC or if the volume of water flowing through the reactor falls below certain limits. However, the government has in the past temporarily raised limits under similar circumstances, particularly when such shutdowns would cause widespread disruption given the lack of hydroelectric or thermal capacity available to replace any nuclear generation taken off line.

In a related story, EdF shut two 1,300 MW reactors at its Paluel station as a precautionary measure after seaweed threatened to block its water intake, The plant, located on the northwest coast was shut down in June last year after heavy storms churned up massive amounts of seaweed that choked the water intake.