It is well known, even not always well accepted, that there is a real lack of knowledge on the mechanisms of sediment transport. The equations which are the core of the Computed Fluid Dynamics (CFD) models have been developed in the first half of 20th century and are still used on most models with some adaptation using ‘’black box’’ coefficients. For the purpose of acquiring better knowledge on the transport mechanisms, ?there is a need for reliable and efficient measurement tools to be used in the field, at real scale, allowing the measurement of data without disturbing the hydrodynamical and physical conditions in the environment. Nuclear techniques are the most useful and efficient ones.The CRP will identify and coordinate the development and improvement of nuclear techniques (radiotracers and nucleonic measurement systems) and the associated methodologies in order to improve their capabilities and the quality of data to be obtained from their use and finally to give to the scientific community the best possible tools to fill the gap of knowledge in the field. Guidelines for the use of the nuclear technologies with a special emphasis on safety and regulatory aspects will be also developed. The CRP will contribute to a larger utilization of nuclear techniques in MSs through the enhanced capabilities and availability of nuclear techniques.