Radioactive Substance Release Risk Assessment for Fuel Mechanical Damage in Fuel Route

Abstract

Irradiated fuel assemblies may be damaged by dropped load or other external force during their operation and storage, resulting in a potential release of radioactive substance. In order to assess the risk of radioactive substance release risk caused by fuel mechanical damage, the methodology of probabilistic safety assessment is used in this study. It takes the initiating events analysis as the starting point, studies the various technical elements involved, and provides the corresponding quantitative assessment results and risk insights. The results of case analysis show that the dominant contribution to the fuel mechanical damage frequency comes from the drop of fuel assembly due to spent fuel pool crane failure. The risk of fuel mechanical damage can be effectively reduced by the purification of spent fuel pool water and ventilation system in the buildings. Optimizing the lifting path of spent fuel cask in hoisting pit to avoid the maximum lifting height exceeding the cask test height, which can greatly reduce the risk of spent fuel cask cask dropping.