The Fukushima accident has pointed out the importance of considering all possible strategies to ensure the cooling of a nuclear reactor core in accidental conditions. Maintaining the fuel coollability would avoid a further meltdown that may cause a rupture of the reactor vessel, significant radioactive releases to the containment of the reactor and, beyond, to the environment. An accident can cause the loss of cooling of the reactor core: a partial or even complete drying of the fuel assemblies may occur. In these conditions, increase of fuel temperature and pressure drop in the reactor core may lead to significant deformation or rupture of the fuel rod cladding, disperse the fragmented fuel and release fission products in the primary circuit. The consequences of cladding deformations on the cooling efficiency when reflooding the core by safety systems are an important safety issue. IRSN conducted a comprehensive assessment on numerous R&D programs performed during the last thirty years, in particular on swelling and rupture of the fuel rod cladding, the impact of this swelling on the cooling of fuel assemblies, the oxidation and the strength of the cladding during the quenching and during the subsequent handling (physical remove or extraction of the fuel assembly out of the core). These studies have led to significant progress in the understanding of these mechanisms; however there are still some pending questions. An R&D program has been launched by IRSN with the support of EDF, including both LOCA experimentation and mathematical modeling.