Chapter Seven - Packed Bed Thermal Storage for LWRs

Abstract

Popular thermal energy storage options currently available are not well suited for grid-scale integration with light water-cooled reactors (LWRs) or nuclear power plants (NPP). Integrating these process solutions either complicates plant layout and regulatory aspects or can even lead to a drastic reduction in thermal efficiency. LWRs produce steam; thus, what is required is a low-cost system to send steam to heat storage at times of low electricity prices and use that steam to generate peak electricity at times of higher prices. Light water-cooled small modular reactors (LW-SMRs) have a compact layout where steam generators or primary to secondary heat exchangers are placed within the reactor vessels. Most of the LW-SMR-based NPP designs cannot accommodate additional heat exchange equipment to recover and store thermal energy from the primary side or reactor coolant, which requires heat energy to be directly recovered from steam. Packed bed thermal storage consisting of inert particles with sufficient thermal conductivity and capacity to efficiently store energy provides a mechanism to directly store the energy of steam.