Under the drive of the “dual carbon” goals, the insufficient frequency regulation capability of nuclear power as a baseload source and the dynamic demand of integrating a high proportion of renewable energy into the grid have increasingly highlighted conflicts. The inherent minute-level regulation inertia of nuclear power units struggles to cope with second-level frequency fluctuations in the grid, leading to an increased risk of system instability. There is an urgent need for energy storage technologies to fill the millisecond-level power support gap for nuclear power frequency regulation. This paper, focusing on nuclear power frequency regulation scenarios, constructs a “Technology–Economy–Policy” multidimensional energy storage evaluation system for the first time. Through a systematic analysis of 11 key indicators, such as response time and safety, the paper selects energy storage technologies suitable for nuclear power frequency regulation scenarios and proposes a hybrid energy storage optimization strategy. The research provides a systematic evaluation framework and empirical support for the selection of energy storage for nuclear power frequency regulation, with significant practical value in improving grid dynamic stability and promoting the construction of new power systems under the “dual carbon” goals.

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.