Scoping study of spent fuel cask transportation accidents

A scoping study of spent fuel cask transportation accidents was performed to provide the NRC with an assessment of existing information and to recommend, on a priority basis, the additional information that should be obtained to allow specification of increasingly realistic source terms. The scope was limited to the escape of radionuclides from the cask to the environment resulting from severe accidents. The accident environment definition associated with a severe accident is the starting point and was selected not for its realism but to allow sensitivity studies on the remaining variables in the accident scenario. However, given this accident definition, the remainder of the evaluation of the accident scenarios is to be as realistic as possible. Information was found to be inadequate to make correlations between accident severity and radionuclide release. Generally, cask and fuel rod thermal-hydraulic data and analytical capability were found to be reasonably adequate; however, data and analytical capability for evaluating structural response to impact are not. Radionuclide behavior information is adequate for noble gases but generally inadequate for most volatile radionuclides and for fuel particulates. A series of gauging calculations were performed to permit prioritization of the information needs, and research recommendations were made in eight areas