Abstract: Different types of dry casks are used globally for storing spent nuclear fuel. As Bangladesh prepares to operate the Rooppur Nuclear Power Plant (RNPP), a reliable dry storage solution will be essential for managing spent fuel assemblies. This study evaluates the thermal behavior of a conventional TN32-B dry cask under long-term storage conditions. The heat transfer mechanisms—radiation between surfaces, natural convection within the air-filled canister, and conduction through solid components—are modeled using steady-state thermal analysis in ANSYS. A detailed temperature distribution is obtained for a cask loaded with 16 fuel assemblies. The maximum fuel temperature was found to be 314.5 °C at the top surface of the assemblies. This result was validated against benchmark data from commercial systems, showing good agreement. The predicted peak cladding temperature remains 61.64 K below the international safety limit of 649.1 K, confirming that the design operates within acceptable thermal margins. A sensitivity analysis was also performed to assess the influence of key parameters—surface emissivity, decay heat load, and ambient temperature—on peak cladding temperature. The Relative Sensitivity Coefficient for decay heat was found to be 0.394, indicating that a 1% increase in decay heat leads to a 0.394% rise in peak temperature. These findings confirm that the TN32-B cask design provides safe and robust thermal performance for extended dry storage across a range of operating conditions. The findings of the Ansys thermal simulation for the TN-32B dry cask clearly show that the safety limitations satisfied the study questions posed in section 2. It is evident from the Ansys thermal simulation findings for the TN-32B dry cask that the section 1 research objectives are also well fulfilled.

Keywords: Dry cask, ANSYS, nuclear waste, peak cladding temperature, sensitivity analysis

Pages: 72-87

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