The United Kingdom Atomic Energy Authority (UKAEA) and the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) have commenced a £3 million, five-year partnership. It will better understand the performance and behaviour of materials required for use in future commercial fusion power plants.
The partnership will involve irradiating materials using neutrons at the ORNL High Flux Isotope Reactor. This is a DOE Office of Science user facility, located in the United States. They will also test these materials at ORNL and at UKAEA’s Materials Research Facility at Culham Campus, Oxfordshire.
One of the major challenges in harnessing fusion energy is developing materials to cope in extreme environments. High energy neutrons and extreme temperatures can weaken or change the desirable mechanical, thermal, optical or electronic properties of materials. This can reduce the lifetime of fusion energy machines.
The research conducted with ORNL will attempt to understand how certain materials respond to irradiation over extended periods, in order to increase the longevity of the materials used.
Dr Amanda Quadling, UKAEA’s Director of Materials Research, said:
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.
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.
Dr Yutai Kato, ORNL’s Interim Director of Materials Science and Technology Division and Manager of Fusion Materials Program, said:
We’re pleased to have this opportunity to build on our collective materials research capabilities to better understand the materials that will be needed for future fusion power plants.
The materials researched under this partnership will primarily focus on the ‘breeder blanket’. This is a component that provides 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 effects of neutron radiation on chemical segregation and precipitate stability. These assessments are critical. They provide assurance that these alloys will be sufficiently durable and reliable to support a fusion power plant throughout the expected lifetime of each component.
In 2021, UKAEA launched the UK Fusion Materials Roadmap. This was with a view to deliver new neutron resilient materials as well as a suite of irradiation and post-irradiation test work to provide design engineers with data to build future fusion power plants.
The learnings from the work will be published in journals and materials handbooks and shared wider with industry. The intention is to accelerate the development of new materials for fusion applications.
The partnership will see staff from the USA and UK visit their counterpart facilities via secondments to share industry skills.