Synthetic Heat Transfer Fluids as Thermal Energy Storage Media for Existing NPPs

This paper provides a conceptual presentation on the integration of existing nuclear power plants with technically robust thermal energy storage solution. Although a more detailed analysis with entire condensate and feed water system integrated to the energy storage solution is required for more accurate analysis, for the conceptual presentation a simpler approach based on energy density and exergy analysis is adopted. Therminol and Dowtherm are commercially available robust technological solutions for this purpose and operate in the temperature range compatible with the existing PWRs. The analysis shows that exergy recovery efficiency is close to 95%, i.e. equal to efficiency proposed using molten salts. The energy density values for these HTFs in this operating range are not expected to create practical challenges and geometrical requirements can be met within the existing nuclear power plants. The energy storage costs with these off the shelf materials already being produced in very large quantities via well established processes are much lower than the projected costs of futuristic grid scale battery solutions. (authors)