UK, US scientists to collaborate on fusion materials research

"One of the major challenges in harnessing fusion energy is developing materials to cope in extreme environments," UKAEA said. "This is because high energy neutrons and extreme temperatures can weaken or change the desirable mechanical, thermal, optical or electronic properties of materials, which can reduce the lifetime of fusion machines."

Under the GBP3 million (USD3.6 million), five-year partnership, materials will be irradiated using neutrons at the ORNL High Flux Isotope Reactor, a DOE Office of Science user facility, located in the USA. These materials will then be tested at ORNL and at UKAEA's Materials Research Facility at the Culham Campus in Oxfordshire, England.

This research will attempt to understand how certain materials respond to irradiation over extended periods, in order to increase the longevity of the materials used.

The materials researched under this partnership will primarily focus on the 'breeder blanket' - a component to provide the fusion fuel, tritium, to make power plants self-sufficient.

Post irradiation testing will include tensile and hardness property measurements, to understand both the effect and extent of radiation-induced hardening and concurrent loss of ductility in these materials.

Advanced microstructural analysis will also be carried out to understand the effects of neutron radiation on chemical segregation and precipitate stability. UKAEA said these assessments are critical to provide assurance that these alloys will be sufficiently durable and reliable to support a fusion power plant throughout the expected lifetime of each component.

The partnership will also see staff from the USA and UK visit their counterpart facilities via secondments to share industry skills.

The project is part of the UK Fusion Materials Roadmap, which was launched by UKAEA in 2021 with the aim of delivering new neutron-resilient materials as well as irradiation and post-irradiation testing to provide design engineers with data to build future fusion power plants.

"The partnership will allow UKAEA access to ORNL’s archive of existing irradiated materials, which include binary iron-chromium alloys, advanced steels, silicon carbide composites and copper alloys," said Amanda Quadling, UKAEA’s Director of Materials Research, "Alongside this, UKAEA will also be placing entirely new materials into the ORNL High Flux Isotope Reactor, including new high-temperature steels developed by both UKAEA and wider UK industry, permeation barrier coatings and welded materials."

"This research collaboration will be a critical piece of the economics of a fusion device in the future, establishing which materials can last for long periods in the fusion environment," added Mickey Wade, ORNL's Fusion Energy Division director. "This is a great opportunity for ORNL and UKAEA to partner on a key area for fusion."

In late-February, UKAEA announced it had awarded contracts worth a total GBP3.1 million (USD3.8 million) to 18 organisations to focus on overcoming specific technical and physical challenges to make fusion energy a commercial reality. The contracts - feasibility studies from GBP50,000 up to GBP200,000 - are funded by the UKAEA's Fusion Industry Programme and awarded through the UK government platform Small Business Research Initiative. The selected projects aim to tackle specific challenges linked to the commercialisation of fusion energy, from novel fusion materials and manufacturing techniques through to innovative heating and cooling systems, all needed for future fusion power plants.