The United Kingdom Atomic Energy Authority (UKAEA) working group has successfully demonstrated the industrial-scale production of fusion-grade steel.
Fusion-grade steel has the potential to reduce production costs by an order of magnitude and improve the efficiency of future fusion power plants.
In just its first year, the NEURONE (Neutron Irradiation of Advanced Steels) consortium has achieved a UK-first breakthrough. The group successfully produced fusion-grade reduced-activation ferritic-martensitic (RAFM) steel on an industrial scale using a seven-tonne Electric Arc Furnace (EAF) at the Materials Processing Institute (MPI) in Middlesbrough.
David Bowden, Group Team Leader for Materials Science and Engineering at UKAEA and NEURONE programme lead, explained: “One of the major challenges for delivering fusion energy is developing structural materials able to withstand the extreme temperatures (at least up to 650°C) and high neutron loads required by future fusion powerplants.”
The NEURONE consortium: Making groundbreaking advancements
The NEURONE Consortium is a £12m collaboration between UKAEA’s Materials Division and academic and industry partners across the UK, as well as international partners, which provide access to neutron irradiation facilities.
NEURONE was established to research, test and develop fusion-grade steel to operate at higher temperatures compared to conventional counterparts.
This will maximise the capacity of fusion machines to extract heat, which is used to power turbines and create electricity, improving the overall efficiency of fusion powerplants.
“NEURONE plans to produce advanced variants of RAFM steel, capable of operating up to 650°C – a stretch target, given the solid-state physics of irradiated materials behaviour,” stated Dr Bowden.
“Developing these types of steel could also benefit adjacent industries that require high-strength, high-temperature structural steels, such as nuclear fission or petrochemicals.”
He continued: “The programme also intends to produce an optimised advanced RAFM alloy using the electric arc furnace at a similar multi-tonne scale to the best EU developmental fusion RAFM steel (EUROFER 97).”
The benefits of fusion-grade steel
The high temperatures and radiation levels caused by the high neutron loads arise as a result of the fusion reaction. Therefore, the structural materials serve an important role in maintaining the integrity of the fusion power plant under these conditions.
Based on EAF technology, with enhanced purification and thermomechanical protocols, fusion-grade steel has the potential to dramatically decrease production costs by up to ten times compared to conventional RAFM counterparts, utilising existing and readily scalable infrastructure within the supply chain.
MPI led the trials, which enabled the manufacture, testing and analysis of specialist high-temperature steels initially at the laboratory scale, leading to industrial-scale trials in their EAF.
“As the only sovereign UK steel research facility able to produce RAFM steel at this scale, this is a groundbreaking moment for nuclear fusion R&D,” said Richard Birley, NEURONE project lead at MPI.
Dr Bowden added: “The production of 5.5 tonnes of fusion-grade steel lays the foundation for cost-effective manufacturing of these types of fusion steel for future commercial fusion programmes.”
Opportunities for steel manufacturers
NEURONE has also produced more than 50 different variants of advanced reduced-activation ferritic-martensitic (ARAFM) steel alloy for analysis.
New approaches have been established for analysing damage to materials, and data has been compiled on the performance of small initial lab-scale melts of material, which range between 100-400 grams in mass.
There is a potential opportunity for specialist UK steel manufacturers to be involved with the NEURONE Consortium’s activity in future, considering different aspects of ARAFM steel manufacture such as forging, rolling, and developing optimised process parameters.
