With the heat wave, nuclear power plants must also adapt. The ubiquitous thermometer is racing in France with temperatures regularly hitting 40°C, and rivers lower and lower. Since August 6, five nuclear power plants have benefited from environmental waivers through September 11 for heat discharge water temperatures, despite the potential negative impacts on the environment.
The principle of operation of a nuclear reactor is to produce electricity from the heat given off by the chain reaction occurring in its core. againstTherefore, nuclear facilities must be permanently cooled in order to be able to operate in complete safety. This explains their construction by the sea or near rivers or streams. They draw from it large amounts of water necessary for the cooling circuit and some reactors, depending on the model, and then discharge it into the nearby stream. However, the discharged water is subject to environmental restrictions and must not exceed the temperature threshold in order to protect aquatic fauna and flora.
Since the heat wave in the summer of 2003, each plant concerned must comply with the discharge standards specified by Nuclear Safety Authority (ASN). To achieve this, power plants reduce their energy in order to reject less water. But, due to historically low electricity production in Europe and France, the electricity grid operator, RTE, has asked to maintain production. Thus exceptions to the discharge criteria were granted for five reactors in operation: Bugey (Ain), Blayais (Girond), Saint-Alban (Isère), Tricastin (Drôme) and Golfech (Tarn-et-Garonne).
“So the restriction makes it possible to refuse a little more hot water than planned.”Jacques Perseboa, director of the Center for Research in Energy Economics and Law.
So far, this exception has only been used once in 2018. It was in Golfech, where the temperature of the water being discharged exceeded the standard. It lasted three days.
But with these bouts of heat multiplying, wouldn’t we risk reaching for a perpetual detraction regime? For the researcher,Slightly different standards should be accepted in the future“.But the central point in his eyes is to find locations.”The most appropriate“For the new French nuclear program. Of the 56 French reactors, 30 have a system with”cooling towers “, allowing the station to be cooled and the steam to be evacuated by steam.”This system is characterized by pumping less water, but returns less because part of it goes into the atmosphere.“, explains Jacques Perseboa. The other system is a system called”Open“Cooling by the river or the sea where”A 900 MW plant needs 40 cubic meters of water per second and then drains 97% of that water, causing the river to heat up.“, continues the specialist. Of the 26 reactors, 14 are by sea.
“Which means that if we want to build new power plants tomorrow, we will have to prefer the seashore. The problem is that it is difficult to find sites”Jacques Perseboa, director of the Center for Research in Energy Economics and Law.
Last February, Emmanuel Macron announced his intention to build six EPR reactors in France, with studies for another eight. RTE highlighted the problem of global warming on the nuclear fleet in its report on the future of the energy system. Of the first six EPR reactors planned, EDF has proposed four by the sea, at Penly (Seine-Maritime), near Dieppe, and at Gravelines to the north. The latter two can come out of the ground in Tricasten or Bougie, on the banks of the Rhone. For them, the electrical network manager depends on the water cooling systems of the refrigeration circuit. Therefore sufficient space will have to be found at future EPR installation sites.
for Jack Persiboa,There are solutions, this does not call into question the program” but “Additional limitations have to be taken into account, Analyse. System must be preferred air conditioner Thus you find space because the towers require more surfaces. There are other solutions, we can try to use the residual heat, we can think about storing the heat in the ground“.