Water management

In France 10% of abstracted water is used by industry but in fact only 7% of this share is really used, as the water used for the cooling of installations (included nuclear power plants) is largely returned to the environment. In a nuclear power plant there are 3 cooling systems: the primary circuit, the secondary circuit and the heat sink. The latter allows the condensation of water after its passage in the turbine. The heat sink requires water abstraction from the environment. Considering water abstraction, there are 2 types of nuclear power plants: those that are equipped with cooling towers and those that are not. The presence of cooling towers implies a closed circuit and the water abstraction is low: a few cubic meters per second per reactor and 30 to 40% of this water evaporates in the cooling towers. The absence of cooling towers implies an open circuit and water abstraction is much more important around 50 m³ per second per reactor and 96% of it returns to the environment slightly warmer. Water discharges are regulated by decrees in order to protect the environment and during heat waves nuclear power plants have to reduced power production to reduce water abstraction and maintain the temperature of rivers below roughly 30 Celsius degrees. (A.C.)