The “smoke” coming out of the cooling towers of the nuclear power plants of Doel and Tihange is actually …… steam.
This steam is not radioactive because it does not come into contact with the primary circuit. The cooling towers are part of the tertiary circuit and serve for the evacuation of heat resulting from the condensation, within the condenser, of steam coming out of the turbines. To learn more about the different circuits of a nuclear power plant, click here.
The gaseous radioactive waste produced during operation of a nuclear power plant is released in a controlled way through the stacks. The thus released radioactivity to the environment must be inferior to the limits imposed by the Authorities. These limits, of course, are very much lower than the potentially dangerous limits.
Cooling towers for that matter are not characteristic of nuclear power plants : classic thermal plants or other industrial installations, that are not directly cooled by a river, a lake or a sea, also dispose of such towers. The electrical CCGT (Combined Cycle Gas Turbine) power plant in Drogenbos, near the Brussels ring-road, is an example of this (see picture).