Nuclear materials

During the coming decades, world is facing the challenge of prolonging the nuclear park life, or implanting new units with new technologies. As an example in the US, it was recently agreed that ‘The Turkey Point Plant’ in Florida extent its live time from 60 to 80 years and on the other side in UK EPR are under construction and several other are planned. In May 2019, the Polish National Atomic Energy Agency forecasted the completion of the first of six 1-1.5 GW units in 2033, with each successive unit to follow every two years, replacing coal-fired generation.

Nuclear energy production needs and will require materials that are extremely resistant under demanding environment: temperature, pressure and irradiation field. These materials are the barriers Their structural properties are investigated with emphasis on mechanical performance, durability, plasticity and stability. The symposium Nuclear Materials includes sessions dealing with materials ranging from structural components of fission thermal or fast reactors, fuel (solid or liquid) materials to waste forms. Production of these materials at the industrial level is discussed on the basis of economic, ecologic and safety considerations. Macro – properties such as quality, thermodynamics, thermophysical and mechanical as well as micro-structural analysis are studied from the atomic scale to the materials within a multi-scale approach.

Scope:

The component materials for Gen II and III, as well as for Gen IV reactors are tested for their behaviour under irradiation with particles (neutrons, protons, deutons …) of high energy and large flux. These are structural materials such as alloys (steels) or composites (cercer, cermet …) or are the coolant e.g. liquid metals or molten salts. The session concerns the R&D for high temperature gas reactors and molten salt reactors.

The fuels consist of solids or liquids with their components (homogeneous/heterogeneous, matrices, fissiles, burnable poisons, fertiles and additives). These fuel materials (oxides, nitrides, carbides, silicides / solid, or fluoride, chloride / liquid  …) are presented in a comprehensive way with emphasis of their intrinsic properties (thermal conductivity, high melting points). The new accident tolerant fuels and the inert matrix fuels shall be discussed in specific sub sessions. This section also includes liquid fuels such as molten fluorides (thermal) or chlorides (fast) for the molten salt reactors. Other liquids may also be investigated if acceptable. Again key properties such as melting points, thermal capacity, … are discussed in this session. A specific attention shall be carried to Post Irradiation Examination because these techniques deliver key results allowing fuel certification.

The waste forms must finally be recognized for their stability, durability, low solubility or leachability over geological time scale. The research includes materials such as homogeneous amorphous (glass) crystalline (spent UO2 fuels) or heterogeneous (Synroc, spent MOX fuel).

In all cases irradiation with accelerator guide the investigators in choosing optimal components prior irradiation in reactor. The challenge this century will be to work with much reliable and robust materials that make their use safer in nuclear system. Specific attention shall be given on the cost in Energy (EJ) during their production and their performance in term of retention of contaminants. The symposium shall contribute in enhancing the safety of the nuclear systems.

The symposium shall be followed by the IAEA technical meeting on Advances in Post-Irradiation Examination Techniques for Power Reactors and Innovative Fuels

Hot topics to be covered by the symposium:

• Green uranium/thorium mining
• Energy cheaper nuclear fuel cycle
• ‘Stronger’ structural materials
• Liquid fuel reactor components
• New nuclear industrial applications
• More performing waste forms
• Education in Nuclear Materials