[en] A 130 metric ton spent fuel rail transport system was impacted at 130 kph into a massive concrete barrier and then engulfed in the flames of a hydrocarbon pool fire. These tests were conducted at Sandia Laboratories as the final phase of a Department of Energy sponsored series in which spent fuel containers were subjected to severe transportation accidents. The objectives of this broad test program were (1) to assess and demonstrate the validity of current analytical methods and scale modeling techniques for predicting damage in real accident conditions, and (2) to gain quantitative knowledge of the accident environment by measuring the response of full-scale hardware under actual crash and fire conditions. The tests are not intended to prove or disprove the validity of the present regulatory standards. The test demonstrated that (1) current scale modeling (impact only) and analytical techniques can conservatively predict the response of a spent fuel cask system in a severe impact and fire environment and (2) spent fuel casks can be expected to retain their integrity even after being involved in extremely severe transportation accidents. In the fire test, the cask was subjected to twice the radiant heat flux and three times the duration of the current regulatory thermal requirement without degradation to the cask structure. In addition, much information has been gained on the behavior of the cask and transport system in extreme environments