The Maanshan plant is scheduled to be decommissioned in 2025. Taiwan Power Company, the owner of the plant, plans to apply exemption from the emergency plan (EP) while the plant is in decommissioning. One requirement for this exemption is that the fuel rod peak cladding temperature (PCT) must be below 565 °C for the postulated complete loss-of-coolant accident in the spent fuel pool (SFP), assuming cooled by air only. In this study, accident analysis models for the Maanshan SFP are developed. First, the decay heat power is calculated based on the specified cooling time. Second, air temperature entering the fuel assemblies is calculated using GOTHIC code, and then is provided as a boundary condition to the following PCT calculation. Finally, the PCT is calculated from the assembly model using Ansys Fluent code. The specified cooling time is acceptable or not is determined by the criterion that whether the PCT is below the limit. With the cooling time of 54 months, the calculated PCT is about 537 °C. Thus, the shortest cooling time allowed for applying EP exemption would be 54 months for the Maanshan units, which is much longer than that of the reference plants. This is because all the spent fuel assemblies are still stored in the SFP, resulting in a higher total decay power. A suggestion of removing the spent fuel assemblies to the dry storage facility is proposed if the Maanshan plant intends to apply the EP exemption while the plant is in decommissioning.