This paper aims to contribute to risk evaluation techniques and applications. The objective is to detect some weakness in ports internal chains based on the risk evaluation approach. Throughput of goods in ports might to be representing as chains of activities and each activity is submitted at their own risks. The combined effect of individual activities risks constitutes the global throughput chain risk. Detection and prevision of risks might to be useful to measure and to improve performances in port's throughput chains. Otherwise, the ports represent links of multimodal transport's chains, and then they play an important roll in the efficiency of integrals transport chains. Frequently, ports are considered only as a knot, as a "black box", where connection between sea transport and in land transport is done, but internal port's throughput operations and their efficiency are rarely studied. We analyze the general port's containers throughput process based on a professional description of individual activities and an evaluation of their own risks. Even if functionality of internal chains is perfectly established ans calibrated, the threats of chains disruptions are always existent. Some risks of individual operations might to provoke light dysfunctions and others the really disruptions in chains. The incertitude of risks importance and non-evaluated risks might to intimidate decision makers in ports, and to provoke mistaken or unnecessary improvements and investments. In this way, evaluation of risks in "ports internal chains" became a useful tool to detect chain's weakness, a guide to prevent eventual chain's disruptions and to planning for improvements. We propose a methodology to risk evaluation of chains based on combined individual risk's effect which allow us to expose the risks importance levels of terminals operations and their implications in a simple way. Finally, we detected the mainly weakness into chains as a result of our risk's analyze in the case of container's throughput in the "Normandie terminal" of the port of "Le Havre".