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.
Under the guidance of the Working Party on Scientific Issues of Advanced Fuel Cycles (WPFC), the Expert Group on Reactor Coolants and Components Technology (EGCoCoT) undertakes activities with the goal to collect, evaluate and preserve relevant scientific data and to "translate" fundamental scientific understanding into application in support of i) the Development of construction codes used for design (design rules), ii) Key technical issues for licensing, and iii) Recommendations for Operation, Inspection and Handling.
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.