The transport of radionuclides at oceanic scales can be assessed using a Lagrangian model. In this review an application of such a model to the Atlantic, Indian and Pacific oceans is described. The transport model, which is fed with water currents provided by global ocean circulation models, includes advection by three–dimensional currents, turbulent mixing, radioactive decay and adsorption/release of radionuclides between water and bed sediments. Adsorption/release processes are described by means of a dynamic model based upon kinetic transfer coefficients. A stochastic method is used to solve turbulent mixing, decay and water/sediment interactions. The main results of these oceanic radionuclide transport studies are summarized in this paper. Particularly, the potential leakage of 137Cs from dumped nuclear wastes in the north Atlantic region was studied. Furthermore, hypothetical accidents, similar in magnitude to the Fukushima accident, were simulated for nuclear power plants located around the Indian Ocean coastlines. Finally, the transport of radionuclides resulting from the release of stored water, which was used to cool reactors after the Fukushima accident, was analyzed in the Pacific Ocean.

In the context of world economic integration, Vietnam's market-oriented economy is facing many opportunities and also many challenges. Market factors are gradually dominating and dominating economic activities, affecting overall economic achievements and in almost all production and consumption sectors. Shipping in general and shipping by the sea, in particular, is one of the economic sectors most affected by the process of openness and international economic integration. As government intervention in the economy decreases, the fluctuations in the total output of the economy, according to the cycle theory, are considered more. Continuous fluctuations and cyclical themselves are made up of variables related to the results of production and business of economic sectors, which transport goods by sea are one of them. Quantitative analysis is being used in many types of research on economic and financial fields in the world as well as in Vietnam. For a more holistic, comprehensive, and scientific view, the use of a powerful quantitative tool, it allows assessment of multidimensional relationships between macro variables and variables that reflect the industry's production results. The Vector Autoregression (VAR) is one of the reasonably standard quantitative models used to determine the multidimensional relationship between economic factors supposedly related to each other. Use this model to analyze the relationship between some key macroeconomic indicators and the volume of goods transported by sea in Vietnam. The author finds that there is a relatively close relationship between import and export turnover of goods and sea transport output. This result suggests many policy ideas to develop both international trade and shipping activities in Vietnam in the current period. On the other hand, the quantitative model used in the project can be applied at the enterprise level to help managers identify the impact of economic fluctuations on production and business results. On that basis, appropriate decisions will be made in the context of ongoing short-term economic fluctuations.