How much water do nuclear power plants consume? – 2023 edition

This study aims to provide interested parties with quick and easy access to a database based on consolidated public sources on water consumption by nuclear reactors in France. It also aims to clarify various concepts that can lead to confusion, such as the distinction between withdrawal and consumption or between open and closed circuits.

It also enables us to visualize the water consumption of power plants at the right level, which is the local level. This study also presents the situation of each Nuclear Power Plant (CNPE) in relation to the cold source from which it uses water.

Here are the main findings:

• In 2021, 97% of the freshwater taken from rivers by nuclear power plants was returned to the original environment. The remaining 3% represented 410 Mm3 of water and now accounts for 12% of French freshwater consumption.
• Over 2021, the average consumption of a nuclear power plant (CNPE) represents 1% of the flow of the rivers in which it is installed.
• The consumption of open-circuit nuclear reactors along the Rhône is very low compared to the two Bugey reactors and the four Cruas reactors operating in a closed circuit. These open-circuit reactors will draw 11 billion m3 of water in 2021, over 99% of which will be returned to the Rhône.
• An open circuit consumes much less water than a closed circuit. But it takes more water from the environment, generating a greater temperature rise between upstream and downstream. There is no systematically preferred cooling method. The choice of technology depends on the specific situation of each plant.

From a methodological point of view, the Sfen report is based on monthly declarations of water withdrawal and consumption by nuclear power plants (source: EDF) and flow data from the nearest hydrometric stations. ■