For environmental protection and economic reasons, process water and reagents are recycled where possible. Thus, water vapour from evaporation is condensed and nitrous vapour is directed to an absorption tower to be recombined into nitric acid.

In accordance with regulations governing radiation protection (see Chapter 2), effluent containing very low levels of activity can be released without treatment to the sea. Where the activity is higher the radionuclides are removed by co-precipitation. The resulting solid wastes are then immobilized. Wastes of relatively low specific activity that do not contain alpha emitters may be incorporated in bitumen.

Higher activity liquid wastes are concentrated by a set of evaporators. These include nitric effluents, those having a significant content of a emitters, tritiated effluents (before vitrification) and non-tritiated refined products from purification of uranium and plutonium.

Raffinates — the concentrated solution of fission products and minor actinides in nitric acid — are stored in permanently cooled and ventilated pulsed tanks prior to vitrification.