Experimental Verification of a Heat Store Model

Russian Engineering Research - A mathematical model of a heat store based on melting of the working medium is verified by means of an experiment. The model describes a heat store containing a...     

Environmental Impact of Structural Metals

The environmental impact of structural metals is assessed on the basis of life-cycle analysis. The environmental safety index is calculated for the most common structural metals. Such assessments permit estimation of the environmental hazards over the life cycle of metals and comparison of the impact of different groups of structural materials—in particular, metals and polymers.     

Cluster Strategy for Eco-Innovation at Manufacturing Enterprises

The environmental hazards of manufacturing are analyzed and the inadequacies of existing environmental protection measures are considered. A graph of the relationships between investment activity in eco-innovation and its outcome is proposed. The environmental impact of manufacturing enterprises may be reduced by more effective organization of innovation on the basis of clusters.     

Effect of boric acid mass transfer on the accumulation thereof in a fuel core under emergency modes at NPPs with WMR

Boric acid mass transfer processes in the reactor facilities with WMR are considered for the case of an emergency with breaking of the main circulation pipeline (MCP) and the operation of the passive safety systems, such as first-, second-, and third-stage accumulator tank systems, and a passive heat removal system (PHRS). Calculation results are presented for a change in the boric acid concentration in the fuel core (FC) of a water-moderated reactor (WMR) in the case of an emergency process. The calculations have been performed for different values of drop entrainment of boric acid from the reactor (0, 0.2, 2%). A substantial excess of the maximum concentration of boric acid has been found to occur 24 hours after an emergency event with a break of MCP. It is shown that increasing the droplet entrainment of boric acid causes the crystallization and accumulation thereof in the FC to become slower. The mass of boric acid deposits on the elements of internals is determined depending on the values of drop entrainment. These results allow one to draw a conclusion concerning the possibility of accumulation and crystallization of boric acid in the FC, because the latter event could lead to a blocking of the flow cross section and disturbance in the heat removal from fuel elements. A review of available literature data concerning the thermal properties of boric acid solution (density, viscosity, thermal conductivity) is presented. It is found that the available data are of quite a general character, but it does not cover the entire range of parameters (temperature, pressure, acid concentrations) inherent in a possible emergency situation at nuclear power plants with WMR. It is demonstrated that experimental study of boric acid drop entrainment at the parameters inherent in the emergency mode of WMR operation, as well as the studies of boric acid thermal properties in a wide range of concentrations, are required.