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Liquid sodium at high temperatures (470 K to 825 K) is used as the primary and secondary coolant in Liquid Metal cooled Fast Breeder Reactors (LMFBR). In the event of a postulated sodium leak in the Steam Generator Building (SGB) of a LMFBR, sodium readily combusts in the ambient air, especially at temperatures above 523 K. Intense sodium fire results and sodium oxide fumes are released as sodium aerosols. Sodium oxides are readily converted to sodium hydroxide in air due to the presence of moisture in it. Hence, sodium aerosols are invariably in the form of particulate sodium hydroxide. These aerosols damage not only the equipment and instruments due to their corrosive nature but also pose health hazard to humans. Hence, it is essential to estimate the concentration of sodium aerosols within the plant boundary for a sodium leak event. The Gaussian Plume Dispersion Model can obtain the atmospheric dispersion of sodium aerosols in an open terrain. However, this model does not give accurate results for dispersion in spaces close to the point of release and with buildings in between. The velocity field due to the wind is altered to a large extent by the intervening buildings and structures. Therefore, a detailed 3-D estimation of the velocity field and concentration has to be obtained through rigorous computational fluid dynamics (CFD) approach. PHOENICS code has been employed to determine concentration of sodium aerosols at various distances from the point of release. The dispersion studies have been carried out for the release of sodium aerosols at different elevations from the ground and for different wind directions.

The main theme of this paper is to save the lives of poor fishermen who is severely punishing by the other country coastal guards. This is achieved with the help of GPS and embedded system. GPS (Global Positioning System) is increasingly being used for a wide range of applications. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the earth. This paper deals on the versatility and the usefulness of a GPS device in the sea. The main objective of the paper is to help the fishermen not to navigate beyond other country's border. If a fisherman navigates beyond the country's border, an alarm is generated indicating that the fisherman has crossed the border. Additionally, a GSM transmitter interface will send a message to base station located on the sea shore indicating that a boat has crossed the border. Thus guards in the shore can assist and provide additional help to those fishermen if needed. Keeping in mind about lives of Indian fishermen, this device has been created to help them not to move beyond the border. On the whole, it is an attempt to build a suitable device for the fishermen at a reasonably low cost.

Core Catcher is provided as an in-vessel core debris retention device to collect, support, cool and maintain in sub-critical configuration, the generated core debris from fuel melting due to certain postulated Beyond Design Basis Events (BDBE) for Fast Breeder Reactor (FBR). This also acts as a barrier to prevent settling of debris on main vessel and keeps its maximum temperature within acceptable creep range. Heat transfer by natural convection in the core catcher assembly has been assessed numerically and through water experiments using geometrically similar configuration. Resistive heating elements are used in experiment as heat source to simulate debris decay heat on core catcher. Series of experiments were carried out for two configurations referred as geometry A and geometry B. The later configuration showed enhanced natural convective heat transfer from the lower plenum of the vessel. Temperatures were monitored at critical positions and compared with numerical evaluation. Numerically evaluated flow fields and isotherms are compared with experimental data for specific steady state temperatures on heat source plate. Numerical results are found to be in good agreement with that obtained from experiments. The combined efforts of numerical and experimental work conclude core catcher assembly with geometry B to be more suitable.Copyright © 2006 by ASME