As France’s grid operator Réseau de Transport d’Électricité (RTE) warned the public that they need to start taking measures to conserve energy as temperatures plummet or face rolling blackouts, the nation’s nuclear watchdog, the Autorité de Sûreté Nucléaire (ASN), has given the go-ahead to restart all but three of the 12 nuclear reactors that have been offline since the discovery last year of widespread “carbon irregularities.”

On January 12, ASN approved the restart of nine reactors affected by the carbon concentration anomaly in the steam generator channel heads manufactured by Japan Casting and Forging Corporation (JCFC). The approval followed ASN’s examination of the results of inspections and technical demonstrations provided by French utility EDF for all the affected 900-MWe reactors.

On January 17, meanwhile, RTE issued advice on Twitter and its website for how people can help reduce electricity use during periods when demand is highest. If, for instance, each household lowers the temperature in their living room by 1 degree Celsius (1.8 degrees Fahrenheit), it would save the equivalent output of two nuclear reactors, according to French energy ministry.

That’s a serious figure given that French power demand is forecast to peak at about 95 GW this week, compared with a record 102 GW in February 2012. Reactor availability remains a problem. Only about 90% of France 58 nuclear reactors are available, about the same as last year. However, usually at this time of the year, EDF has almost all its reactors online to maximize supplies during cold weather. Two years ago, availability was 99%. But at the end of 2016, France’s nuclear availability stood at around 83%.

If the voluntary demand reductions aren’t enough, RTE may start to implement “exceptional measures” that include shutting off factories and dimming lights across the country, it said. RTE added that it would shortly announce whether these measures are required.

The nine reactors that can now be restarted are Bugey 4, Dampierre 3, Fessenheim 1, Gravelines 2 and 4, Saint-Laurent B1, and Tricastin 1, 3, and 4. All of these are 900 MWe units. ASN had ordered EDF in October to carry out additional inspections on the steam generator channel heads of certain reactors within three months.

On January 11, the company asked that the inspection deadline for Unit 2 of the Tricastin plant be postponed by two weeks due to the cold weather, despite the immediate risk to the national electrical grid.

EDF also asked that the inspection deadline set for Civaux 1 be postponed until the end of March. ASN said it is examining data provided by EDF for the 1,450-MWe Civaux Units 1 and 2 with assistance from France’s Institute for Radiological Protection and Nuclear Safety.


Lee Buchsbaum (, a former editor and contributor to Coal Age, Mining, and EnergyBiz, has covered coal and other industrial subjects for nearly 20 years and is a seasoned industrial photographer.