Reactor Safety for Lead or Lead-Bismuth (LBE) Cooled Reactors-Fuel-Coolant Interactions

The most widely used reactor type in the world is the light-water reactor (LWR) where two types are more common: PWR and BWR (pressure and boiling water reactors), along with Canada Deuterium Uranium reactor CANDU, gas-cooled reactors (AGR & Magnox), light water graphite reactor (RBMK & EGP), fast nuclear reactor (FBR) – Russia. At European level a collaborative effort supported by the European commission and leading European research institutes and industries was started to bring advanced fuel cycles and the P&T strategy together in order to investigate its economic and technical feasibility. The exploratory research done in the field and the launch of the Sustainable Nuclear Energy Technology Platform (SNE-TP) in 2007 lead to a joined effort from the European nuclear fission research community to issue a Strategic Research Agenda (SRA) that describes the roadmap towards sustainable nuclear fission energy. Here, the SNE-TP community identifies the sodium fast reactor technology as the reference but also highlights the need for the development of an alternative track with lead or gas cooling. In addition, the need for R&D activities in support of accelerator driven systems (ADS) was stressed to allow the demonstration of ADS technology by the construction of the first ADS Demo facility (MYRRHA). With regard to alternative fast reactor technologies as described in the SRA, lead cooled fast reactor (LFR) systems are very promising in meeting the Gen IV requirements in terms of sustainability, economics, safety and reliability and proliferation resistance & physical protection. This assessment is based on inherent properties of the reactor coolant and on design choices made. Reactor safety with regard to fuel-coolant interactions is an important step in the feasibility and safety assessment of such technologies. Theoretical and empirical approach will be further presented both for lead and lead-bismuth interaction with the nuclear fuel, in this case with UO2 and MOX fuel.