Cask manufacturing methods and quality assurance problems

This paper presents the results of a study performed to identify and evaluate cask manufacturing methods and materials which are presently or could be readily available in the United States. The study includes a comparison of the economic and technical advantages to be gained from manufacturing casks specifically for application to long-cooled fuel (5 years or greater) and waste materials. The conclusions that have been drawn from this study, which is still in progress are as follows: if spent fuel payloads are in fact cooled for five or more years prior to transportation there is a significant advantage to be gained from cask designs which are tailored to this longer cooling time; the most economic cask design is that which utilizes a lead gamma shield; the all-steel, single wall casks show substantial potential benefits resulting from ready availability and the cost and inspection advantages that result from the design simplicity; the future use of depleted uranium shielded casks in the United States is expected to be low as a result of the high cost and lack of manufacturing facilities; of the three types of neutron absorber systems evluated, the borated cast-in-place silicone rubber shows significant technical and cost advantages; andmore » design and fabrication code requirements and regulatory requirements yet to be developed in the United States are likely to have a profound effect on the next generation of transportation casks.« less