Update on impact effects in nuclear plants Part III - Review of heavy object drop

The consequences of an accidental drop of a heavy component from a lifting device in a nuclear power plant are required to be evaluated even though the device may have been designed using good engineering practice. This paper summarizes some industry experience regarding heavy object drops and quantifies the range of accident parameters of interest. The main subject matter deals with the local and global (overall) structural behavior of floors and associated structures due to impact. Present methods of design/analysis and available test data are reviewed. In general, the available test data is sparse for large-size, low-velocity missiles which are typical for heavy object drops, and therefore current analytical approaches are considered to be unproven. Limitations of current approaches and recommended research are presented