[en] In French nuclear power plants, the secondary water conditioning is essentially based on the use of a volatile amine and a reducing reagent. The additional use of a corrosion inhibitor is limited to units with secondary side corrosion of Alloy 600 MA SG tubes. The main aim of secondary water treatment optimisation is to achieve the best compromise as follows: to minimize the different types of corrosion of the different PWRs materials (copper corrosion, flow assisted corrosion, SG fouling and secondary side corrosion), to reduce operation and maintenance costs (short term and long term), to minimise the impacts on the environment, to protect workers health. In a first part, this paper describes the studies recently carried out to try to optimise the secondary water treatment in French PWRs. They concern the possibility to use ethanolamine (ETA) in replacement of morpholine and ammonia and the possibility to use carbohydrazide (CBH) in replacement of hydrazine. In a second part, this paper presents the French secondary water treatment policy established in 2000, which is depending on the presence or not of copper alloys. (authors)