Industrial water management for nuclear power generation

The use of nuclear power plants to generate most of the electricity consumed in mainland France is a major environmental asset in terms of limiting the production of greenhouse gases, which are responsible for global warming. All the more reason, therefore, for this electricity production to be carried out with the utmost respect for other environmental aspects, in addition to safety and economic imperatives. Water resource management is a key environmental issue, firstly because of the limited quantities of fresh water available, secondly because of the warming of rivers associated with global warming, and thirdly because of all the discharges made into water.

It is therefore important for the operation of nuclear power plants to manage this scarce resource as effectively as possible in all three respects: the quantity of water available, thermal discharges, and chemical and radiochemical discharges. Most water is required to cool the condenser, while a small quantity is needed to produce demineralized water to supplement the various nuclear power plant circuits. These requirements do not differentiate a nuclear power plant from a conventional thermal power plant fuelled by coal or oil, which are therefore no alternative to limited water resources.

The solution for the first two aspects (quantity of water and thermal discharges) is to locate as many nuclear power plants as possible (5 out of 19 at 1 ^er January 2008) by the sea or in estuaries, but it is imperative to distribute production points over the territory in a way that is compatible with consumption locations. For the 14 river-cooled power plants, water heating is limited by the use of cooling towers on 11 of them. On the other hand, this technology presents a number of difficulties, as described in this dossier, including chemical or other treatments to combat scaling (precipitation of calcium salts under the effect of concentration and temperature) and the proliferation of pathogenic micro-organisms. Regulations in this area are increasingly draconian, in line with the precautionary principle regarding potential microbiological and health impacts. This considerably complicates chemical treatments and the resulting discharges into the river. Industrial water management is further complicated by the fact that it is superimposed on the other limitations on liquid chemical and radioactive discharges associated with the operation of these nuclear power plants.