“Half of the country’s reactors are closed and I am announcing that this summer there are still others that will be closed.” Sunday, May 22, Jean-Luc Mélenchon recalled, during an appearance on the program “Le Grand Jury”, on RTL and LCI, that he was not a nuclear fan. He castigated the use of this energy, a few days after the publication of the annual report of the Nuclear Safety Authority (ASN), on May 17, which returned to the “corrosion problems” identified in the piping of several reactors.
Half of nuclear reactors are already shut down, partly for corrosion reasons. I warn you, there may be others this summer because of the drought. #TheGrandJury pic.twitter.com/hfJnjDSNMM
— Jean-Luc Melenchon (@JLMelenchon) May 22, 2022
In this same passage from the “Grand Jury”, the “Prime Minister candidate of the New People’s Union”in his own words, warns against “intermittency” nuclear energy and urges France to develop offshore wind energy to cope to global warming. According to him, the drought which is already affecting France threatens the proper functioning of the reactors in the weeks to come. “Half [des réacteurs] is already closed, partly for corrosion problems, but this summer it will be because of the heat, the drop in the level of the rivers and the warming of the water. You can’t cool a nuclear power plant with hot water!” he added.
Indeed, nuclear power plants are located on the banks of rivers, rivers or the sea because they need water to cool their reactors. Some plants are equipped with cooling towers (TAR) but still require water to run their cooling system. So, is Jean-Luc Mélenchon saying true or fake?
As of May 24, 27 of the 56 French nuclear reactors were effectively shut down, according to EDF, or nearly half. From day to day, the number of reactors in operation may vary. On May 16, 29 reactors were shut down. In May, approximately 50% of the reactors were out of operation. For 12 of them, it is an unexpected shutdown due to a “corrosion problem”.
On the other hand, for the others, the shutdowns have been planned for a long time to carry out maintenance or refueling operations. These suspensions, which can last between one and six months, are scheduled for spring because electricity needs are lower than in winter. A special case should be noted in Chinon (Indre-et-Loire): a reactor is shut down due to a crack identified on a weld in its cooling circuit.
So what will happen this summer, since Jean-Luc Mélenchon projects himself into this period? Impossible to say with certainty if other reactors will be shut down due to the drought or the heat wave. The risk exists, given the summer weather forecast. In 22 of the 96 departments of France, the Ministry of Ecological Transition estimates “very probable” the risk of drought by the end of summer 2022 (PDF). In line with a month of May with record temperatures. Olivier Dubois, Deputy Director of Safety Expertise at the Institute for Radiation Protection and Nuclear Safety (IRSN) also judges “difficult to make predictions. Everything will depend on the summer weather. IIt is possible that reactors will be shut down, in the event of a heat wave or drought, this happens quite regularly.
Thereby, between May 9 and 15, the Blayais power plant (Gironde) had to slow down its electricity production due to a heat spike. Located on the edge of the Gironde estuary, the reactors of this plant depend on its water to cool. However, during a heat wave, the temperature of the water is too high to be used by their cooling system. In case of drought, it is the flow of the rivers which is insufficient. Especially since the problems of drought and heat waves can accumulate. During the July 2020 heat wave, EDF decided to shut down one of its reactors in Golfech (Tarn-et-Garonne).
Plants most prone to shutdowns “are those of Tricastin (Drôme), Saint-Alban (Isère) and Bugey (Ain), because they are located on the Rhône, a river whose temperature increases significantly during the summer. But the Golfech plant, which has an air-cooling tower, could also be subject to shutdown, because in summer, the flow of the Garonne is sometimes too low”, explains Olivier Dubois.
Will the energy supplier be forced to opt for such procedures again this year? Jean-Luc Mélenchon’s predictions can only be verified at the end of the summer. However, given the weather forecasts for the coming summer and the history of shutdowns during the last heat waves, Jean-Luc Mélenchon’s warning is not unfounded.
In reality, even if the water in the streams is “hot”, it could be used by the plant’s cooling system. But such an operation would further warm the rivers or rivers in which the water is taken and then discharged, which poses an environmental problem. This is therefore not a technical problem but a regulatory one. In order to protect the ecosystem of waterways, maximum discharge temperatures for water used to cool nuclear reactors are set specifically for each plant, according the conditions defined by the Nuclear Safety Authority (ASN).
Thus, when the temperature of the water used for cooling nuclear reactors exceeds the limit set by interministerial decree, the reactors are shut down. These limits also depend on the season. For example, in the case of Gironde, “before May 15, the winter regulations apply with a maximum authorized water temperature level of 30 degrees. After May 15, this threshold increases to 36.5 ° C”, Explain Fabrice Guillonenergy company of the CGT EDF, to Echoes.
Water that is too hot can promote the proliferation of algae and disrupt fish reproduction. However, in the event of heat waves jeopardizing the ability of the electricity network to meet electricity demand, ASN may authorize EDF to temporarily exceed the maximum water discharge temperatures. Reinforced monitoring of the environment is then put in place, according to the ASN.