Measurement of some radioelement activities in some water samples from the Miner Moulouya river area at the North-East of Morocco

The natural radioactivity in natural waters comes mainly from the primordial radionuclides in soils. Further, some cosmogenic radionuclides and/or radionuclides originated from pollution can be found in these waters. The polluting radioelements can rise from industrial wastes, geological erosion of U- bearing rocks or excessive utilization of agricultural fertilizers. The natural radioactivity of groundwater varies greatly, high concentrations of natural radioactive elements have been found not only in water from U mines, but also in some other sources of water. Concentrations of natural radioelements in natural samples depend on the physico-chemical conditions and on the geological, geographical and socio-economical environment. Rivers transport the major path by which most of products of chemical weathering on land reach the sea. The concentration and isotope ratios of U- and Th-series nuclides in river water are, therefore, very important parameters needed to construct geochemical balances for these elements. Several types of chemical reactions strongly affect the chemistry if some elements and some radionuclides such U can be scavenged from solution into river bottom sediments. Desorption of Ra by the increased salt content in the mixing zones drastically changes the dissolved Ra contributed to the ocean by rivers. In this work we report and compare activities and activity ratios of some radionuclides obtained on some natural water samples collected at sites situated along of The Moulouya river at the North-east of measured radionuclides with those found in other Moroccan and international natural water sources