Nuclear Engineering and Design 240 (2010) 1699–1706 Contents lists available at ScienceDirect Nuclear Engineering and Design journal homepage: www.elsevier.com/locate/nucengdes Spent fuel transport cask thermal evaluation under normal and accident conditions G. Pugliese, R. Lo Frano ∗ , G. Forasassi Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, n ◦ 2-56126 Pisa, Italy article info Article history: Received 7 October 2009 Received in revised form 11 February 2010 Accepted 23 February 2010 abstract The casks used for transport of nuclear materials, especially the spent fuel element (SPE), must be designed according to rigorous acceptance criteria and standards requirements, e.g. the International Atomic Energy Agency ones, in order to provide protection to people and environment against radiation exposure particularly in a severe accident scenario. The aim of this work was the evaluation of the integrity of a spent fuel cask under both normal and accident scenarios transport conditions, such as impact and rigorous fire events, in according to the IAEA accident test requirements. The thermal behaviour and the temperatures distribution of a Light Water Reactor (LWR) spent fuel transport cask are presented in this paper, especially with reference to the Italian cask designed by AGN, which was characterized by a cylindrical body, with water or air inside the internal cavity, and two lateral shock absorbers. Using the finite element code ANSYS a series of thermal analyses (steady-state and transient thermal analyses) were carried out in order to obtain the maximum fuel temperature and the temperatures field in the body of the cask, both in normal and in accidents scenario, considering all the heat transfer modes between the cask and the external environment (fire in the test or air in the normal conditions) as well as inside the cask itself. In order to follow the standards requirements, the thermal analyses in accidents scenarios were also performed adopting a deformed shape of the shock absorbers to simulate the mechanical effects of a previous IAEA 9 m drop test event. Impact tests on scale models of the shock absorbers have already been conducted in the past at the Department of Mechanical, Nuclear and Production Engineering, University of Pisa, in the ‘80s. The obtained results, used for possible new licensing approval purposes by the Italian competent Authority of the cask for PWR spent fuel cask transport by the Italian competent Authority, are discussed. © 2010 Elsevier B.V. All rights reserved. 1. Introduction The perspective of a worldwide “nuclear renaissance” for elec- tricity production, is also related to the nuclear spent fuel issues in terms of both short- and long-term management. Nevertheless the problem of how to manage spent fuel in the interim, before a per- manent solution is agreed upon, is widely discussed in all countries that use nuclear power for the reason that it is important to under- stand all the issues involved in spent fuel storage and transportation to make the best choices possible. Moreover nuclear power genera- tion is recommended as a promising way to contribute to long-term energy supply and as a measure against global warming. In this context, waiting for the future deployment of the today under development Generation IV reactors projects, as well as of a closed fuel cycle, the spent nuclear fuel (SNF) represents an open ∗ Corresponding author. Tel.: +39 050 2218093; fax: +39 050 2218065. E-mail address: rosa.lofrano@ing.unipi.it (R.L. Frano). issue to be explored thoroughly the used uranium fuel is widely referred in literature to as “spent fuel”. Spent nuclear fuel is the nuclear fuel that has been irradiated in a nuclear reactor during the operation of nuclear power plants (NPP) to the point where it is no longer useful in sustaining a nuclear reaction. Historically, the generated spent nuclear fuel is designated as useful recyclable energy resource. SNF shall be properly stored until the reprocessing, that allows to chemically separate the valu- able material, such as uranium or plutonium, from the waste, was done. Moreover intermediate storage of spent fuel is important as a means for contributing to the flexible operation of the overall nuclear fuel cycle. In fact the design of the packaging system is strictly related to the need to protect the population and environment from exposure to the radiation emitted by the radioactive materials contained in the spent fuel. Therefore a cask packaging system must ensure that: • The spent fuel remains contained even under severe accident conditions; 0029-5493/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.nucengdes.2010.02.033