Topical day on compatibility of structural materials with heavy liquid metals

Topical day:  Avril 29, 2008

Scope

In recent years the technology of heavy liquid metals (HLM) has been gaining importance in different fields of applied nuclear research including waste reduction by transmutation, energy production via fission and fusion, nuclear medicine and the development of experimental research tools.

Transmutation in Accelerator Driven Systems (ADS) is a promising way to diminish the current world stock of minor actinides and fission products. Present day ADS designs use either HLM or gas as core coolant. As spallation target material and coolant, however, HLM is employed in every case. In nuclear energy production, a new generation of fast spectrum reactors with lead or its alloys as coolant is a candidate for development within the Generation IV initiative. In fusion research, lead lithium alloy is being investigated as a possibility to serve as tritium breeding material.

Finally, intense neutron sources act as an important research tool in physics, biology, medicine and material science. Spallation target technology, in which a high intensity proton beam interacts with a HLM can be used to generate these neutrons.

Intense neutron sources, be it from spallation targets or from new generation reactors or accelerator driven systems, can also be used to produce a wider range of medical radioisotopes than is the case with conventional thermal reactors.

It is clear that a thorough knowledge of the technological characteristics associated with the use of HLM in these applications is essential for successful development and engineering. This has been recognised worldwide and it is subject to large international investigations such as the MEGAPIE-initiative, the GNEP programme, GEN IV's LFR, J-PARC project and in Europe within the EURATOM framework programs such as the FP6-integrated project EUROTRANS, the FP6- I3-initiative VELLA and also the FP7-coordinated project GETMAT, where SCK•CEN is heavily involved. A large part of these efforts concerns the search for structural materials that are able to withstand the combination of intense irradiation, thermal and mechanical loads and HLM induced embrittlement, corrosion and erosion. The second part of the ongoing R&D deals with the fundamental and technological properties of the HLM.

The goal of the Topical Day is to present the current status of research concerning the compatibility of the selected candidate structural materials with the heavy liquid metal coolants in terms of their mechanical properties degradation due to corrosion, irradiation, thermal and mechanical loads, liquid metal embrittlement, etc. and to give perspectives for future developments.