Netherlands nuclear research and consultancy group (NRG) has completed the irradiation testing in its High Flux Reactor (HFR) at Petten of a new type of metal that will be used in a test programme for the International Thermonuclear Experimental Reactor (Iter) under construction at Cadarache in Southern France.
Together with the Swedish company Studsvik, NRG characterises the specially developed low-activation Eurofer97 alloy steel that is to be tested in Iter. It is designed to reduce long term radioactivity after exposure to radiation in ITER, or to higher exposure in future fusion reactors. The test performed at NRG is intended to demonstrate that Eurofer97 is sufficiently resistant to the radiation environment in Iter.
Components for use in Iter are still being developed. These include test set-ups inside which tritium will be produced by interaction with the neutron radiation generated in the fusion reaction. The material properties for the steel casing of the set-ups needs to be charaterised.
Four irradiations with steel samples began in December 2016 in the HFR and was completed on time in 2018. The materials are now transported to Studsvik (Sweden) where the properties will be analysed in detail to show whether the materials are suitable for the test set-ups in Iter.
This work has been financed by the European Union’s (EU’s) Fusion for Energy (F4E), which manages Europe’s contribution to Iter. F4E receives funding from the EU. Studsvik and its subcontractor NRG were awarded a contract in October 2015 for a detailed technical analysis of the physical and mechanical properties of Eurofer97. F4E has also contracted Germany's Saarschmiede GmbH to deliver various Eurofer97 finished products. A total of about 27 tonnes of Eurofer97 will be manufactured as special plates and bars with thicknesses ranging from 1.2mm to 45mm.
The Iter project includes China, Europe, Japan, India, South Korea, Russia and the USA. From injecting a thermal input of 50MW into its plasma, Iter will produce a thermal output of 500MW for about seven minutes. The first plasma operations are envisaged to start in 2025, with deuterium-tritium fusion experiments scheduled for 2035. Construction costs are expected to be around €20 billion ($25 billion), with components contributed by the Iter members on an 'in-kind' basis. The main aim is to demonstrate that nuclear fusion is a viable energy source, with no CO2 emissions or long-lived radioactive waste.
Photo caption: The High Flux Reactor (Credit: NRG)