Molten Salt Reactor Dispatch Optimization via Thermal Energy Storage: Coupled Thermodynamic Modeling and Rolling-Horizon Economic Analysis

Abstract Integrating molten salt reactors with molten salt thermal energy storage represents a promising pathway to enhance grid flexibility and mitigate renewable intermittency. This paper presents a thermodynamic framework for a molten salt reactor (MSR) interfaced with a dual-tank nitrate salt TES system and a steam Rankine cycle, parameterized against the KP-FHR commercial reference design. A co-simulation architecture couples the thermodynamic plant model with a rolling-horizon dispatch optimizer, wherein the thermodynamic module resolves instantaneous thermal states and propagates updated system variables at each optimization interval. The objective function maximizes revenue from electricity markets by leveraging locational marginal pricing and net load signals, subject to the steady-state reactor thermal output constraint. A case study is performed using 15-minute-resolution CAISO day-ahead price and grid load data for a representative summer operating day. Coupling a TES system within the MSR's intermediate molten-salt loop yields a 20.1% increase in net power block output, achieved without uprating the reactor's thermal capacity. The TES subsystem enables load-following operation by charging during periods of suppressed grid demand and discharging stored thermal inventory during peak load events, effectively decoupling reactor operation from power block dispatch and smoothing power oscillations at the grid interface. The results presented provide a technical basis for integrating thermal energy storage into advanced nuclear systems, with potential implications for the operational flexibility and reliability of low-carbon energy grids.