In response to the contradiction between the insufficient flexibility of nuclear power due to the high proportion of renewable energy grid connection and the increasing demand for system frequency regulations, this paper proposes a coordinated operation model of a nuclear–storage consortium. It uses all-vanadium redox flow batteries as the flexibility transformation solution. Referring to the PJM market and the Guangdong electricity market mechanism, a two-tier optimization model for the nuclear power–energy storage consortium’s participation in the electricity energy/secondary frequency regulation market is constructed. The upper layer optimizes the scale of energy storage configuration, and the lower layer realizes joint clearing based on the Security-Constrained Unit Commitment–Security-Constrained Economic Dispatch (SCUC-SCED) framework. It takes into account the nuclear frequency regulation safety share constraint and energy storage performance coefficient. The case analysis demonstrates that the configuration of 70 MW/70 MWh vanadium redox flow batteries can increase the annualized net income of the consortium by 2.8429 million yuan, mainly by shifting the nuclear power regulation space from the energy market to the high-value frequency regulation market. This study verifies the feasibility of the nuclear–storage synergy model in enhancing market competitiveness while ensuring nuclear safety, providing a quantitative reference for the flexibility transformation of nuclear power and the design of power market mechanisms.

In response to the contradiction between the insufficient flexibility of nuclear power under the high proportion of renewable energy grid connection and the increasing demand for system frequency regulation, this paper proposes a coordinated operation model of nuclear storage consortium, using all-vanadium REDOX flow batteries as the flexibility transformation solution. Referring to the PJM market and the Guangdong electricity market mechanism, a two-tier optimization model for the nuclear energy storage consortium to participate in the electricity-secondary frequency regulation market is constructed. The upper layer optimizes the scale of energy storage configuration, and the lower layer realizes joint clearing based on the SCUC-SCED framework, taking into account the nuclear frequency regulation safety share constraint and energy storage performance coefficient. The case analysis shows that the configuration of 70 MW/70 MWh vanadium REDOX flow batteries can increase the annualized net income of the consortium by 2.8429 million yuan, mainly by shifting the nuclear power regulation space from the energy market to the high-value frequency regulation market. The study verified the feasibility of the nuclear storage synergy model in enhancing market competitiveness while ensuring nuclear safety, providing a quantitative reference for the flexibility transformation of nuclear power and the design of power market mechanisms.