Stainless steel cans, of various sizes and designs, are used for the storage of nuclear fuel. For the purpose of formal risk assessment, it was necessary to determine the pressure limits of each type. Internal pressure testing, to failure, was carried out on batches of cans to different designs and weld procedures. Statistical analysis of the results was used to determine lower-bound properties. Weibull failure distributions were obtained for each type of can and found to be suitable for the purpose of assessment. The knowledge gained of failure probability as a function of pressure provided a suitable for input to the formal risk assessment process.