The debate on the use of water resources by nuclear power plants has been revived, while the deputies have been examining since Monday March 13 the government bill to accelerate the development of nuclear power in France, as Emmanuel Macron wishes.
>> Acceleration of nuclear power: what should be the purpose of the bill examined in the National Assembly?
The majority, in favor of the text, and the opposition, believing that the reactors consume too much water and that there is not enough, have begun to challenge each other with a lot of figures from the presentation of the text in the Economic Affairs Committee to the National Assembly at the beginning of the month, Wednesday March 1, then the exchanges continued on Twitter. But who is right? We try to see more clearly.
The power plants return 98% of the water withdrawn
Responding to criticism, the rapporteur of the bill, Maud Bregeonalso a Renaissance deputy for Hauts-de-Seine and a former EDF engineer specializing in nuclear power, said that “the reactors, indeed, need water to be cooled, it is water which is taken and it is water which is then returned and, that is very important”. The engineer relied on numbers: “Open cycle reactors restore 100% of the water they take, closed cycle reactors certainly restore only 60%, but consume less”she explained.
Contrary to what EELV/LFI says, the water needed to cool nuclear power plants is not consumed, but taken and returned.
Power drops during heat waves are occasional and minimal (reread the RTE report), with no impact on safety. pic.twitter.com/0oiQaIr94B
— Maud BREGEON (@MaudBregeon) March 2, 2023
And indeed, these figures are correct. RTE mentions them in its prospective report on “Energy Futures 2050”, published in October 2021. Of the 56 reactors currently in the French nuclear fleet, 26 are in “open circuit”, this means that “cold water is pumped into the river or the sea, cools the secondary circuit through the condenser, then is discharged into the river with an increased temperature”. For the 30 other reactors, in “closed circuit”, “The water taken and heated in the condenser then circulates in the air cooler, where it is cooled before being discharged into the river. This process leads to a net water consumption of around 40% of the water taken”. In other words, 60% of the water withdrawn for these reactors is returned to where it came from and the other 40% evaporates, literally, through this kind of white smoke that flies over the cooling towers .
Nevertheless, these closed circuit reactors take much less water than the others, to the point that these evaporations represent a very small percentage of all the water used by the power stations. The French Nuclear Energy Society – an association founded in the 1970s to support the industry – claims that only 2% of the water used by power plants goes up in smoke. The Council of State proposes the same water consumption scales in its 2010 public report entitled “Water and its rights”: “The water consumed represents between 1% and 3% of withdrawals” by nuclear power plants, he says.
But they consume between 20% and 30% of water resources
Except that, from the point of view of natural water resources, these evaporations represent a lot. The national secretary of Europe-Ecologie Les-Verts, Marine Tondelieraffirm that “nearly a third of the water consumed in France is dedicated to nuclear power plants” and that nuclear power is “the 2nd item of consumption after agriculture”. And the number she uses is also true. Or rather, he was.
From the National Assembly (cc @MaudBregeon) on the radio (cc @dseux), we hear all kinds of lies or untruths about nuclear water consumption.
➡️nearly 1/3 of the water CONSUMED in France is dedicated to nuclear power plants.
We explain everything to you https://t.co/WJILN5qR6I
— Marine Tondelier (@marinetondelier) March 7, 2023
It is given in the latest Environmental Report of France published in March 2022 by the Ministry of Ecological Transition. It can be read that, between 2008 and 2018, “agriculture is the leading water-consuming activity with 45% of the total, ahead of cooling power plants (31%), drinking water (21%) and industrial uses (4%)”. Nevertheless, contacted by TF1 on Monday March 13, the ministry disputed its own figure, considering that “the data in question were now dated and no doubt overstated” and specifying that the ministry’s statistics service was in the process of making a new count.
Other sources rather give a figure around 20%. In 2010, the Council of State, in particular, estimated that water consumption by nuclear power represented “22% of the volume consumed” in total in France in one year. Figure quoted by the Water Information Center and then by the French Nuclear Energy Company. With this estimate, nuclear power is no longer the second largest water consumer, but the third, after agriculture and drinking water.
“Limited” impact of the drought according to RTE
“At this rate, there will soon not be enough water in our rivers to cool the power plants”, is alarmed the ecologist Marine Tondelier, referring to the depletion of water resources, drought and climate change. On the contrary, the impact of global warming on the operation of power plants “is minimal”, answers the rapporteur of the bill Maud Bregeon. Which one is right?
The power of some reactors has already had to be lowered due to the high temperatures. In June, EDF slowed down one of the reactors at the Saint-Alban power station (Isère) because the flow of the Rhône was too low. Most often, the reactors are slowed down because of the temperature of the rivers: the water there is hot and the discharges from the power stations would heat it up even more and this would pose a problem for biodiversity – which the Sortir dunuclear network denounces. Nevertheless, last summer, power stations obtained exemptions to be able to continue to operate when the temperature of the rivers was too high, to the detriment of the regulation and the preservation of the fauna and flora of the rivers.
Result, “on an annual scale, the energy lost corresponding to these unavailabilities is globally limited”nuance RTE in its report, “less than 1% except in 2003, marked by a major heat wave”.
While it is difficult to know what will happen in the future, the company responsible for transporting electricity has tried to assess the consequences of global warming on power plants by 2050. RTE affirms that “these trends will have a direct effect on the cold source of nuclear reactors, and potentially on their availability. (…) For riverside sites, with unchanged regulations and without adaptation of existing facilities, the risks of unavailability of units should increase”. Difficulties linked to climate change affect only 4 sites out of 18, according to RTE. “The risk of unavailability for climate-sensitive reactors could increase by a factor of two to three.”
Consequently, RTE recommends installing new power plants by the sea, where they are not affected by the problems of drought and the drying up of waterways.