Following the Fukushima Daiichi accident, Chinese nuclear power plants implemented extensive safety improvements addressing extreme external events, prolonged station blackout, loss of ultimate heat sink, spent fuel pool cooling, severe accident mitigation, and emergency response. A key issue beyond the initial implementation of these measures is how the associated safety functions can remain available and effective throughout long-term plant operation. This study examines the linkage between post-Fukushima engineering and emergency improvements and operational safety management through a document-based comparative analysis of regulatory and technical documents, improvement reports from the Qinshan and Daya Bay nuclear power bases, and national reports and policies concerning equipment reliability, initiating events, probabilistic safety assessment (PSA), maintenance effectiveness, and configuration risk management. The analysis shows that the improvements extended beyond hardware reinforcement to equipment interfaces, procedures, inspection, testing, maintenance, training, and emergency drills, making functional availability a continuing management requirement. Accumulated equipment reliability and initiating-event data provide an increasingly localized basis for PSA and risk-informed decision-making, while maintenance effectiveness evaluation and configuration risk management connect risk information with equipment performance monitoring, maintenance planning, and operational decisions under changing plant configurations. PSA and risk-informed approaches had already been introduced in China before the Fukushima accident; the accident therefore reinforced and broadened their subsequent application rather than marking their starting point. Overall, the study identifies a linkage from engineering improvement to functional availability, risk information, and long-term operational safety management, clarifying how accident-driven safety upgrades are connected to their continued management during plant operation.