Nuclear power plants, warming and heat wave

Or how EdF is lobbying to counter standards for the cooling water temperature of its atomic power plants.


The heat wave of 2003 had revealed it, the heat wave of 2006 confirmed it: nuclear power plants are very sensitive to an ambient temperature above the average! Reason: a power plant must be cooled with river water. However, not only are these waters currently warmer (heat wave), but the flow of rivers is also limited (drought). And since EdF has, in theory, no right to heat water by more than X ° C.

Thus the values ​​X is fixed at 0,3 ° C for the installations located on the edge of the Garonne, at 1,5 ° C for the installations located on the edge of the Meuse, Moselle or Seine and at 1 ° C for the installations located on the banks of the Rhône, partially or entirely equipped with atmospheric cooling towers. This value is brought to 3 ° C in the absence of such turns.

Since the flow of the river is constant and the temperature difference is fixed by the standards, there is a problem of heat balance and concerns about cooling (or warming) are therefore created. A drop in power could easily solve the problem ...

Only here: EdF cannot easily lower its production because the strong development of individual air conditioners (since 2003) now requires stronger power during the summer (+ 3% compared to normal in July according to RTE). Mechanical air conditioners are therefore not at all a solution to the problem of global warming, on the contrary they largely contribute to the overheating of urban centers and the overconsumption of electricity! And to say that there are solar air conditioners ... but this is another debate.

In order to meet demand, EdF therefore has no other choice than to reject hotter water than required by the Standards…

Read also: CITEPA: inventory of emissions by large combustion plants in France

Here are some excerpts from Press:

1) Heat wave: EDF wants its plants to reject warmer waters

EDF has asked the government to exceptionally authorize, in the event of a heat wave, its nuclear and thermal power plants located along the river to take and discharge cooling water at temperatures "slightly above" standards, the group announced. Saturday.

"The need to maintain the security of electricity supply on the territory, in the current conditions of very persistent heat in several European countries, led EDF to request, as a precaution, the implementation of exceptional measures with the public authorities ", EDF said in a press release.


The request for authorization was made to the ministries of Finances, Ecology and Health which, if they accept it, will take an interministerial decree in this direction, explained a spokesperson of EDF joined by AFP.


At Golfech, the water returned is at a maximum of 30 degrees against 28 usually, while in Bugey, it is at a maximum of 27 degrees against 24 normally, EDF said in its press release.

To explain its decision, the group pointed out that "the exceptional heats of recent days, higher than 3 at 6 degrees to seasonal norms, have led to a historic rise in river temperatures" and weakened water resources, "indispensable to the hydraulic production "and the cooling of power stations.

2) Heat wave: derogations for water discharges granted to EDF

In a press release, EDF pointed out, however, that a similar device had been put in place during the heat wave in 2003 and "that no impact on the flora or fauna had been observed".
Exemptions have already been granted this summer for three plants located on the Garonne and the Rhone.
The company recalls that it was recently forced to buy electricity on the wholesale markets to guarantee the supply of French territory.
On July 19, EDF announced that it had purchased 2.000 megawatts of electricity abroad.

Read also: Cool Earth to fight against global warming?

3) Heat wave: derogation and nuclear power plant 3 everywhere…

Exceeding these temperature thresholds could lead to the shutdown of several power plants.

EDF has asked the Government to authorize derogations on the temperature of discharges into the water for 6 thermal generating stations in Blénod, La Maxe, Porcheville, Aramon, Richemont and Cordemais.

Nelly OLIN, Minister of Ecology and Sustainable Development, has ruled out for the moment any possibility of derogation for 3 of the central 6 concerned. This decision was taken, after consultation with the Ministry of Industry, based on the analysis of its services in terms of impact on natural aquatic environments and in view of the information provided by the transport network manager. electricity, RTE. Indeed, the operation of these plants does not appear essential to the continuity of power users.

It authorized, as a precaution, the prefects to make exemptions for central 3 (Aramon, Cordemais and Richemont). These derogations are triggered only in cases of absolute necessity in order to maintain the safety of the electricity distribution network and are accompanied by accompanying measures relating to respect for the environment.

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