López Quintela, Manuel ArturoSpino, José LuisJovani Abril, RaquelUniversidade de Santiago de Compostela. Facultade de Química. Departamento de Química Física. Institute for Transuranium Elements Joint Research Centre2014-11-262014-11-262014-11-26http://hdl.handle.net/10347/11897High-performance ceramics with nanosized grains provide today the technical base for a large variety of improved applications in many technologies. This type of microstructure is of special interest as well in the nuclear field as it appears at the periphery of light water reactor (LWR) UO2 fuels at high burn-up (BU), where the material transforms spontaneously to a closed porous nanocrystalline nc-structure after surpassing a critical dose. The mechanical properties of this newly formed material are superior to those of the fresh fuel due to the nanostructure. Taking this into account, the aim of this work is to develop a fuel consisting of nc-UO2, which, besides the advantages of enhanced plasticity and faster creep, characteristic of the nc-state, which diminish the pellet clad interaction (PCI) stresses and cladding failure risks, has also the potentiality to develop closed porosity under irradiation, to largely retain fission gases. The study of its behaviour is therefore important, especially during accident conditions under which large amounts of radioactive fission products could be released into the reactor vessel, or to the exterior if the core containment breaks. Its potentiality for retention of fission gas and its improved mechanical properties and resistance to radiation-damage make so the nc-fuel material worthy of deep experimental analysis.engEsta obra atópase baixo unha licenza internacional Creative Commons BY-NC-ND 4.0. Calquera forma de reprodución, distribución, comunicación pública ou transformación desta obra non incluída na licenza Creative Commons BY-NC-ND 4.0 só pode ser realizada coa autorización expresa dos titulares, salvo excepción prevista pola lei. Pode acceder Vde. ao texto completo da licenza nesta ligazón: https://creativecommons.org/licenses/by-nc-nd/4.0/deed.glhttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.glNanocrystalsCeramicsAqueous and organic synthesisNanostructureHigh burn-up structureMaterias::Investigación::22 Física::2210 Química física::221004 Química de coloidesMaterias::Investigación::22 Física::2210 Química física::221026 Fenómenos de dispersióndoctoral thesisopen access