Influence of potable water cleaning techniques on the radiological quality of water

In case of accidental radioactive discharges, the drinking water would not represent the first concern for the definition of the total radiological risk; however, it would generally constitute the first concern of the consumer. The purpose of the results come from experiments carried out in laboratory and were to evaluate the efficiency of two type of processing of drinking water on the elimination of the radionuclides cesium and strontium. Therefore, a catchment water was contaminated with radioactive aerosols representative of an accident. Then, it was made potable on the one hand, using a traditional process (clarification and filtration on sand then on activated carbon), and on the other hand, by a less traditional but easily integrable technique within an already existing process, in which sand is replaced by zeolite. The performance at the end of the processing using sand is average for cesium (from 67 to 73 % according to the type of coagulant injected) and becomes frankly poor for strontium (between 46 and 51 %). The results obtained with the process including of zeolite are very satisfactory. The performance at the end of the processing as well reach 99 % for strontium as for cesium whatever the type of coagulant used. The present study thus made it possible to show the insufficiency of the processing known as 'traditional' of drinking water towards to the elimination of the radionuclides cesium and strontium, but also to outline the features of a new process still to improve radioactive decontamination of water. (authors)