The recirculation valve is a key component in the emergency core cooling system, primarily serving to establish natural circulation and prevent core overheating in the event of a LOCA accident. Its reliability is critical to the overall accident safety of the reactor. The spring in the valve is the key component that leads to valve failure. Therefore, this paper focuses on the reliability of the valve spring. Using high-temperature creep experimental data for the material, finite element analysis (FEA) is performed on the spring. Additionally, accelerated testing methods are employed to calculate the spring's service life at the design temperature. The impact of pit defects at different locations on the spring's surface on its creep behavior is also investigated. The study concludes that the spring has a service life of approximately 61.2 years at 613.15 K. Surface defects cause uneven stress distribution at the corresponding locations of the spring, significantly reducing its service life. The effect of defects at different locations on reliability varies. Defects at the outer side and lower end of the spring accelerate creep more significantly. This research can provide valuable insights for valve spring design and reliability verification, and it can also support the calculation of the overall valve service life and failure probability.