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.

Traditional in-service inspection (ISI) methods for pipelines have certain limitations in identifying pipeline leakages. When these methods are directly applied to the ISI of Hua-long pressurized reactor (HPR1000) nuclear power plants, where the system complexity has significantly increased, they may lead to insufficient inspection efficiency and an extremely heavy workload. In this study, based on the framework of typical risk-informed analysis methods for nuclear power plants in the industry and integrating domestic engineering practical experience, an optimized ISI model for pipelines in HPR1000 nuclear power plants was constructed, and a pilot application was carried out on the chemical and volume control system (RCV) of the primary circuit. The inspection strategy was optimized through a series of steps, including determining the analysis scope, conducting pipe segment failure analysis, constructing a risk matrix, selecting inspection elements, and assessing risk impacts. Case studies showed that the risk-informed in-service inspection (RI-ISI) method successfully classified over 3000 welds in the RCV system based on risk levels (high, medium, low). After optimization, 16 low-risk welds (risk level 7) and one of the two medium-risk welds (risk level 4) that originally required volumetric inspection were exempted from inspection. Quantitative risk analysis confirmed that the increments in core damage frequency (CDF) and large early-release frequency (LERF) caused by this optimization were far below the regulatory limits. This method significantly reduces the inspection burden of medium- and low-risk pipelines while ensuring that high-risk areas receive priority attention, providing important technical support for the safe and efficient operation and maintenance of HPR1000 and subsequent third-generation nuclear power units.

Under high renewable energy penetration, nuclear power units face significant challenges in peak regulation and market clearing due to constraints on minimum technical output and ramping capability. To address this issue, a long-term power system of Guangdong Province in 2035 is taken as the study case, and an energy–reserve co-clearing simulation framework based on Security-Constrained Unit Commitment (SCUC) and Security-Constrained Economic Dispatch (SCED) is established to systematically evaluate the clearing performance of nuclear power and the formation mechanism of residual electricity under multiple market scenarios. On this basis, a nuclear power-coupled Alkaline Electrolysis (AEL) hydrogen production pathway is proposed as a peak-shaving utilization option, and an economic assessment model for nuclear-based hydrogen production is developed to quantify the investment performance under different hydrogen production capacities and operating modes. The results indicate that the integration of an AEL hydrogen production system can effectively alleviate the rigidity of nuclear power output. Under the “12-3-48-3” flexible peak-shaving mode, the residual electricity available for hydrogen production increases by approximately 30% compared with a typical peak-shaving strategy. Under scenarios with low electricity prices and green hydrogen prices, when the hydrogen production capacity is configured at 50–100 MW, the investment payback period is approximately six years, and the project exhibits strong economic robustness against variations in the discount rate. These findings demonstrate that nuclear-based hydrogen production is economically feasible in future power systems with high renewable penetration, providing quantitative support for nuclear flexibility enhancement and the coordinated development of low-carbon energy systems.

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.

China’s nuclear power plants traditionally operate to meet baseload needs, with minimal involvement in peak load regulation. However, as the share of renewable energy generation rapidly increases, the volatility of the power system and the demand for peak load regulation have significantly risen, necessitating greater nuclear power flexibility to meet the new power system’s requirements. Our study forecasts the energy structure and load demand for the Province of Liaoning in Northeastern China in 2035. Under this vision, it analyzes the flexibility challenges faced by nuclear generation units. A joint clearing model for spot electricity and ancillary services, along with an energy storage revenue model, was established. Based on this, this study analyzed the clearing results for various typical scenarios in the Province of Liaoning in 2035. The simulation results demonstrate that nuclear units will participate in peak shaving by the target year. This study demonstrates the feasibility of solid-state thermal storage in improving both flexibility and economic efficiency of nuclear generation. Based on these findings, policy recommendations are proposed, including improving regulation compensation mechanisms and promoting multi-energy coupling, providing crucial theoretical and practical support for the role transformation of nuclear generation entities in the new power system. This study establishes a full lifecycle economic assessment model for combined heat and power revenue versus thermal storage investment costs, considering integrated nuclear power–solid thermal energy storage heating systems as the primary technical pathway. Taking a configuration plan with a 715 MW heating capacity and a 6000 MWh thermal storage capacity as an example under Liaoning Province’s 2035 long-term scenario, the simulation results indicate that introducing solid thermal energy storage can significantly improve the revenue structure of nuclear units while meeting deep peak shaving demands, reducing the project’s static payback period to under 11 years.

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.