Risk assessment and numerical analysis of short-term accident scenarios in a nuclear fuel storage vault

• Published in: Numerical heat transfer. Part A, Applications Vol. 85; no. 17; pp. 2896 - 2916
• Main Authors: Mishra, Vivek Kumar, Panda, Saroj Kumar, Sen, Biswanath, Samantaray, Dipti
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 01.09.2024; Taylor & Francis Ltd
• Subjects: Accident conditions; Air flow; Air temperature; Blackout; computational fluid dynamics (CFD); Cooling; Cooling systems; Cooling water; decay heat; Fuel storage; natural convection; nuclear fuel storage; Nuclear fuels; Nuclear reactors; Nuclear safety; Numerical analysis; Risk analysis; Risk assessment; Storage facilities; Suction; temperature distribution; Uncertainty analysis
• ISSN: 1040-7782; 1521-0634
• DOI: 10.1080/10407782.2023.2230354

Analysis of various accident scenarios is vital for the safety assessment of nuclear fuel storage facilities. The accidents in the storage vault due to loss of cooling are generally considered highly uncertain since the accident progression is slow (in comparison to reactors) and allows time for remedial activities to the operator. In the present work, numerical simulations of different accident scenarios have been carried out for a short duration to understand the situation better. Thermal aspects of accident conditions such as failure of the suction blower, drying of cooling water at the chiller, and combined effect of both accidents were investigated. The airflow inside the ventilated enclosures due to the failure of the blower and the rise in inlet air temperature is analyzed numerically. The temperature distributions inside the vault and the rise in temperature of the sub-assemblies and magazines have been studied. The key mechanisms of heat transfer, which take part in nuclear fuel storage vault for post-accident conditions, were identified. The study will be helpful to classify various accident conditions based on their thermal implications and the model developed can be used to design passive cooling systems.