.png)
Summarize with AI
How much electricity does a nuclear power plant consume?
Mis à jour le
January 28, 2026
4
Min reading
A nuclear power plant transforms heat into electricity through the fission of an atomic nucleus. It is composed of one or more reactors that are organized into nuclear units.
According to recent figures, it allows produce a large quantity of energy. Now, what about the one that the nuclear power plant consumes to carry out this transformation? SirEnergies provides you with some clarifications on this consumption.
An electrical consumption of 20 TWh/year in the French nuclear fleet
It exists several nuclear power plant technologies. Here we will focus on BWR and REP technologies.
There are power plants with a pressurized water reactor and those with a boiling water reactor. All the nuclear reactors used in France use pressurized water. They have three power levels:
- 900 MW
- 1,300 MW
- 1,450 MW
The 900 MW one produces on average 500,000 MWh of nuclear electricity per month. The higher the power of the reactor, the more this quantity of nuclear energy increases. To have such an efficiency, it first consumes electricity.
In France, all nuclear power plants consume approximately 20 TWh/year for auxiliaries (pumps, preheating, ventilation, uranium enrichment, etc.). Either 5% of French production.
Uranium-235
Inside a nuclear reactor there are fuel elements that are several meters long. These in turn are composed of fuel rod bundles in which nuclear fuel is found, uranium-235. It is in the form of pellets and a few are enough to activate the fission process that will produce heat. To create this phenomenon, the pellets are assembled and placed in a tank filled with water.
The temperature of the latter rises as soon as it comes into contact with the pellets (the water is first heated thanks to the friction of the water in the primary circuit and then fission takes over to raise the temperature of the water). However, the reactors keep the water under pressure and prevent it from boiling.
It circulates in a closed circuit which is called a primary circuit. It then goes through a steam generator and Transmits its heat to the water present in a secondary circuit. This water in turn heats up and becomes steam. It will activate the turbines that will drive the alternator that will produce electricity.
Each of these machines deploys great power, they require a lot of energy to function properly.
Enrichment of fuels
After its extraction, the uranium is precipitated, filtered, washed and dried. It is then rid of its impurities and is transformed into uranium hexafluoride (UF6). In this refined but natural metal, there are 993 g of uranium-238 compared to only 7 g of uranium-235.
Although it is the only one that is fissile, uranium-235 cannot be used in reactors with such an isotope. Its proportion must be between 30 and 50 g for it to be able to undergo nuclear fission, which will allow the production of electricity.
It is for this reason that it must be enriched before transforming it into pastilles. This step requires a lot of energy, nearly 19,000,000 MWh per year. This is explained by the multitude of machines that are involved during the operation. The methods that have been developed for enrichment are:
- gaseous diffusion
- The ultracentrifuge
When it reaches 56°C, uranium hexafluoride goes into a gaseous state. As soon as it is in this form, it is diffused through barriers that are thin partitions pierced with small holes. Being lighter than uranium-238 molecules, those of uranium-235 cross barriers more quickly.
However, after a single pass, the quantity of uranium-238 remains present in considerable quantity. To reach the right proportion of uranium-235, the process is therefore repeated at least 1,400 times.
Ultracentrifugation has gradually replaced gaseous diffusion and is used in almost all power plants in the world. With this method, enrichment takes place in a set of centrifuges.
They are each equipped with a rotor that makes between 50,000 and 70,000 rpm. This speed makes it possible to separate, in the gas, the two uranium molecules. Those that are heavy are projected onto the wall and those that are light (isotope 235) remain in the center.
The gas enriched in uranium-235 rises and is recovered then sent to another juicer. The cycle will be repeated several times to obtain the desired proportion of uranium-235. Ultracentrifugation also consumes a lot of electricity, but this is less than that spent by the first process.
The pump station
The pump station provides the nuclear power plant with the water it needs to function properly. It comes from a river, a river or a sea near the power plant. If the source has a high flow rate, the water pumped is several tens of m³ per second.
If not, only a few m³ are sampled per second. This cold water circulates through thousands of tubes that are in a condensing device. When the steam that drives the turbines to produce heat comes out, it comes into contact with the tubes. The water inside cools and condenses it until it becomes liquid again.
A pump then brings it back to the steam generator for a new cycle while the condenser water, which is now hot, is rejected. However, when river or sea flow is low, it is sent to cooling towers. The current of air that circulates in the tower cools it. Much of this water is returned to the tubes and the rest evaporates into the atmosphere.
This device makes it possible toavoid thermal pollution and to limit the heating of the water source. There is also electricity used in control rooms and for exports.
To go further, do not hesitate to read our in-depth article on” Nuclear energy: between innovation and energy transition ”.
Did you know that?
The quantity of ARENH (Regulated Access to Nuclear Historic Energy) that a site can benefit from depends on its consumption profile, and more precisely on its consumption during the hours called “ARENH”.
SirEnergies advises you for Advance your ARENH law and increase the possible share of ARENH in your price formula. This will have a direct impact on Lower your electricity bill.
Our tools analyze your past consumption to give you advice for optimizing your ARENH right.
Click below for more information:
Take the first step towards optimization
In a few clicks, organize an exchange with one of our experts.
weekly newsletter subscribers
4.9
The answers to your questions
Is Bellenergie Business electricity really green?
.png){kind=icon}
Yes. The supplier guarantees an offer 100% renewable via the official Guarantees of Origin (GO) mechanism.
For the most demanding companies, the offer GREENVOLT+ ensures very low carbon intensity electricity, sourced exclusively from independent French producers (hydraulic, wind, solar).
Qu'est-ce qui remplace l'ARENH depuis le 1er janvier 2026 ?
Le dispositif ARENH a laissé place au VNU (Versement Nucléaire Universel).
Ce changement structurel expose davantage les entreprises aux prix de gros, rendant la gestion des risques plus complexe qu'auparavant.
Il devient alors indispensable de définir une stratégie d'achat d'électricité avec Sirenergies pour lisser l'impact de la volatilité des marchés sur votre budget.
What are the main taxes applicable?
Among the taxes include TICFE, TICGN, CTA, CJA and TURPE. They represent a significant part of the bill and vary according to consumption profiles. Understanding them well is essential to optimize costs.
Comment l'eau est-elle transformée en électricité ?
Le processus repose sur l'utilisation de la force de l'eau (énergie cinétique) issue des courants, des chutes d'eau ou des dénivelés. Le fonctionnement suit trois étapes clés :
- Le barrage retient l'eau et l'oriente vers des conduites.
- La pression de l'eau fait tourner une turbine, créant de l'énergie mécanique.
- Une génératrice (alternateur) transforme cette énergie mécanique en électricité, laquelle est ensuite adaptée par un transformateur pour le réseau
Pourquoi la France a-t-elle exporté un volume record d'électricité en 2025 ?
Ce record de 92,3 TWh s'explique par la conjonction de trois facteurs :
- Le redressement du parc nucléaire : Après les problèmes de corrosion sous contrainte de 2022, la production nucléaire a retrouvé une forte disponibilité (373 TWh).
- L'essor des renouvelables : Une capacité installée en hausse (solaire et éolien) et une production hydraulique solide.
- Une consommation intérieure atone : La demande française reste inférieure de 6 % à la moyenne historique, créant un surplus massif disponible pour nos voisins.
What is the difference between €/MWh and kWh?
The €/MWh is a price unit used in wholesale markets, while kWh is the unit visible on your bills.
Which taxes are particularly relevant for farms?
Farms are subject to taxes such as TICFE or TICGN. Sirenergies verifies their application, identifies cases of exemption and accompanies the procedures to reduce the tax burden.
Pourquoi mon contrat est-il en kVA et ma consommation en kWh ?
Le kVA mesure la capacité maximale que votre compteur peut supporter à un instant T, tandis que le kWh mesure la quantité d'énergie consommée sur une durée.
What are the challenges for tertiary companies?
Tertiary companies must manage their energy costs while guaranteeing the comfort of users (offices, shops, services). Consumption is often linked to heating, air conditioning and lighting, which requires precise monitoring to avoid budgetary excesses.
How to properly define your subscribed power?
The subscribed power must be calculated according to the consumption profile and uses (heating, industrial processes, tertiary equipment). One fine analysis makes it possible to ensure the adequacy between real need and contract.
What are the customer reviews on bellenergie Business's customer service?
In 2025, the supplier had a NPS (Net Promoter Score) of +16 and a note of 4,17/5.
Satisfaction is based on a “zero solicitation” model and 100% in-house customer service in Toulon, guaranteeing proximity and responsiveness that cannot be found with major historical suppliers.
What are the consequences of overpowering?
Exceeding capacity leads to financial penalties and can impact the size of the contract. Adjust the correctly subscribed power makes it possible to avoid these additional costs.
How to optimize the taxes and contributions of a community?
Communities are subject to taxes such as TICFE or TICGN. Sirenergies analyzes invoices, identifies exemption possibilities and fixes possible errors to reduce the tax burden.
Quel est l'impact de ces exportations sur le prix de l'électricité pour les entreprises ?
L'abondance de production française tire les prix du marché de gros vers le bas.
En vertu du mécanisme de l'Ordre de Mérite (Merit Order), les centrales les moins coûteuses (nucléaire, renouvelables) couvrent la demande plus souvent, évinçant les centrales à gaz ou charbon plus onéreuses.
Cela multiplie les épisodes de prix bas, voire négatifs, sur le marché spot.
Quel est le nouveau record 2025 d'exportation d'électricité de la France ?
En 2025, la France a atteint un solde exportateur net de 92,3 TWh, battant le précédent record de 2024 (89 TWh).
What taxes are particularly relevant to manufacturers?
The industry is concerned by TICFE, TICGN and other contributions that may represent an important part of invoices. Sirenergies identifies cases of exemption and accompanies the procedures to benefit from them.
What are the electricity offers offered by bellenergie Business?
The range E @sy is available in four pricing structures to adapt to each risk profile:
- E @sy Fixed: 100% budget visibility without variation.
- E @sy Click: Smoothed price thanks to staggered purchases on the markets.
- E @sy Block + Spot: A mix between a secure base and a portion indexed to daily prices.
- E @sy Sport: A 100% dynamic offer to take advantage of downside opportunities in real time.
What is energy sourcing?
Sourcing consists in identifying and analysing the offers of several electricity and gas suppliers. This approach makes it possible to obtain contracts adapted to the consumption profile and budgetary constraints of the company.
What are the PP1 and PP2 alert days?
These are signals sent by RTE during periods of tension on the electrical network. The Sirenergies tool informs you in real time to anticipate your uses.
What is the point of following Spot & Forward prices?
This makes it possible to choose the right time to contract, secure your budgets and anticipate increases.
How to optimize taxes and contributions?
Tertiary companies are concerned by taxes such as TICFE or TICGN. Sirenergies checks the accuracy of invoices, identifies possible exemptions, and helps correct errors to sustainably reduce costs.
Quel est l'impact réel de la rénovation de l'éclairage public ?
C'est le levier le plus rapide pour obtenir des résultats visibles. L'éclairage représente environ 40 % de la consommation d'électricité d'une commune.
Passer au LED avec pilotage intelligent permet de réduire la facture de 50 à 80 %, avec un retour sur investissement (ROI) rapide, souvent estimé à 2 ou 3 ans.
Quelle est la différence concrète entre le transport et la distribution d'électricité ?
Le transport (RTE) correspond aux "autoroutes" de l’électricité. Il s’agit de transporter de très grandes quantités d'énergie sur de longues distances, depuis les centrales de production (nucléaires, barrages, parcs éoliens offshore) vers les régions de consommation.
La distribution (Enedis) s'apparente aux "routes départementales" et aux rues. Elle récupère l'électricité à la sortie du réseau de transport pour la livrer directement chez le client final, en abaissant la tension pour qu'elle soit utilisable par vos appareils.
Why launch an energy tender?
Un appel d’offres permet de mettre en concurrence plusieurs fournisseurs d’électricité et de gaz afin d’obtenir des conditions contractuelles optimisées. C’est une démarche transparente qui permet de choisir l’offre la plus adaptée aux besoins budgétaires et techniques de l’organisation.
L'hydroélectricité est-elle une énergie "propre" ?
Oui, elle est considérée comme une énergie renouvelable à faibles émissions de gaz à effet de serre.
De plus, l'eau ne subit aucune transformation chimique durant le cycle de production et réintègre son milieu naturel en aval.
Cependant, la construction de barrages nécessite des mesures pour protéger les écosystèmes (débit minimum, passes à poissons).
How do I get a tax exemption?
Some businesses may obtain a partial or total exemption from the TICFE or the TICGN, depending on their activity and energy intensity. The support of an expert makes it possible to identify the eligibility criteria and to put together the file.
How do I read an electricity or gas bill?
One invoice consists of several elements: consumption, supplier share, taxes and contributions. The analysis of each line makes it possible to identify possible errors and to check the consistency with the signed contract.
Pourquoi le kVA est-il crucial pour les entreprises ?
Parce que la puissance souscrite en kVA détermine le prix de l'abonnement et que tout dépassement peut entraîner des surcoûts importants.
Qu'est-ce que le cosinus phi
C'est l'indicateur d'efficacité d'un appareil électrique ; il représente le ratio entre la puissance active (utile) et la puissance apparente (totale).
The answers to your questions
No items found.