F4E to test steel material for the fusion reactors of the future

ITER, the biggest international collaboration in the field of energy, will explore the viability of fusion and operate as a test bed for tritium breeder blanket concepts, known as Test Blanket Modules (TBMs) that will be located in the equatorial ports of the machine.

F4E is responsible for the design, manufacturing and delivery to the ITER site of these European high-tech components. Particular importance is attached to the materials of these components because they will be exposed to neutron irradiation, which can have a negative impact on their performance. Therefore, a set of parameters need to be taken into consideration before fabrication.

The candidate steel material that Europe is considering to use is EUROFER97. Amongst its many advantages, this steel responds well to neutron activation with a good resistance to neutron irradiation. It is compatible with liquid metal and ceramic breeders and its properties seem to respond well at high temperatures.

Through a contract signed between F4E and Stusdvik, a series of tests will be performed to help us learn more about the physical and mechanical properties of this steel. Studsvik and NRG, its subcontractor, have signed a contract in October to carry out the work and come back with a detailed technical analysis. The works are expected to last five years and will cost approximately 3.7 million EUR.

NRG will irradiate specimens in the High Flux material test Reactor in Petten (HFR) under controlled conditions similar to those in ITER at 300˚C and 500˚C. After irradiation, the material samples will be transported to Studsvik for post-irradiation examination and characterisation of the materials. The irradiated specimens will be compared with non-irradiated ones. These tests and examinations will be conducted to quantify how far neutron irradiation affects fatigue properties, fracture toughness, causes deformation and or influences the mechanical properties of this potential structural material for blankets of future fusion reactors.

The successful partnership of the two SMEs is another example of the potential contribution made by companies that are small in size but big in innovation.