Lead-bismuth eutectic (LBE) is a very effective nuclear coolant because of its low melting temperature, high boiling temperature and neutronic transparency. In addition, LBE itself is a very efficient spallation target for neutron generation via a high-energy proton accelerator. On the other hand, liquid metal corrosion and embrittlement are major issues that must be dealt with in using LBE as a nuclear coolant and spallation target. Thus, LBE continues to be the subject of considerable research in the United States, Europe and Asia, specifically within the framework of the accelerator-driven transmutation systems and fast-spectrum reactors. An expert group that addresses the major issues associated with the use of LBE as a nuclear coolant in a unified framework is of benefit to all the interested parties. The main deliverable of the expert group was the LBE handbook.
The objectives of the expert group were to:
A number of HLM experiments were underway in Europe, such as the EUROTRANS project (devoted to the study of high-level nuclear waste transmutation with sub-critical accelerator-driven systems) and the ELSY project (devoted to the development of an HLM-cooled critical transmutation system). Moreover, additional experimental results were expected from laboratories in Japan, the United States and Korea. These new experimental results were crucial to consolidate:
Finally, the successful completion of the MEGAPIE experiment would deliver unique results on materials behaviour in HLM and representative conditions of a high power neutron spallation target. Consolidation of the understanding of HLM properties, the materials and thermal-hydraulics assessment, as well as the technological advancement, will be an essential contribution to the development of selected Gen-IV fast reactors and radioactive waste transmuters.
The former Expert Group on Heavy Liquid Metal (HLM) Technology was active for several years and its main objective was to issue a handbook with a collection of theoretical approaches and experimental data in order to deliver recommendations relevant for the design of HLM nuclear systems.
The task force developed best practice guidelines by performing a benchmark study on thermo-hydraulic modelling of heavy liquid metal coolant, e.g. lead and lead-bismuth eutectic (LBE) alloy.