Day-San, G.C. Blackett, M. Dornhofer, A.K. Manduku, M.D. Anderton, L. Tanure, T.P. Davis, ‘Supply and demand of tungsten in a fleet of fusion power plants’, Fusion Engineering and Design, https://doi.org/10.1016/j.fusengdes.2025.114881 

Nuclear fusion has the potential to become a carbon-free, abundant energy source for both electricity and hydrogen markets. Tungsten is a key material for plasma-facing and internal shielding components, protecting the reactor’s structural elements from fusion plasma erosion, high temperatures, and radiation damage. 

This study combines the latest insights into tungsten’s behaviour in fusion environments, including neutron-induced material damage estimates, with realistic fusion power plant designs (ARIES-ST and EU-DEMO-2015 models) and neutronic simulations. It also incorporates an analysis of the tungsten supply industry to evaluate the supply and demand for tungsten in a fleet of future fusion power plants.  The results emphasise tungsten’s crucial role in ensuring the sustainable operation of fusion power plants, particularly in tokamak reactors. Additionally, the findings highlight the urgent need for increased domestic mining resources to meet the growing demand for tungsten and ensure reliable operations by the 2050s. Three tungsten supply scenarios were explored, demonstrating the necessity for new mining resources by the mid-2040s to maintain a sustainable supply for fusion plants by 2100. Without domestic tungsten sources, the UK or US would likely face significant supply shortages, necessitating substantial investment and expansion. 

The collaboration with Tungsten West Plc and Guardian Metal Resources Plc has been instrumental in deepening the understanding of tungsten’s role and the associated future requirements of the fusion energy sector. Tungsten West, a leader in Western tungsten mining and supply, brings valuable industry expertise, and Guardian Metal Resources Plc is a leading U.S.A focussed tungsten exploration and development particularly at their Nevada based projects. Their contributions, alongside with UKAEA FIP, have been crucial in addressing the complex challenges of tungsten supply for fusion power plants. 

Oxford Sigma is committed to advancing solutions at the intersection of materials science, fusion energy technologies and pragmatism, with a focus on accelerating sustainable fusion power. This tungsten study is a key part of Oxford Sigma’s mission to make fusion energy a practical, safe, and scalable solution for the global energy transition. 

“Being an UKAEA FIP student has been a great opportunity to apply what I’ve learned to real-world challenges. Understanding tungsten’s key role in fusion power has made me even more passionate about sustainable energy, and it’s exciting to contribute to such important research.”

~Elektra Day-San – FIP Summer Placement Student, first year Physics and Philosophy Undergraduate at the University of Bristol

“Tungsten West is thrilled to participate in this important study, which underscores the growing demand for tungsten as the world increasingly embraces sustainable energy solutions. This collaboration emphasises the necessity for the tungsten mining industry to enhance its efforts to address future fusion power needs, and we are dedicated to being at the forefront of this transition.”

~Tungsten West Plc 

“As a company dedicated to the important reshoring efforts ongoing worldwide for key critical metals, with a primary focus on mined tungsten supply in the U.S.A., this study highlights the rising importance of tungsten as an essential energy metal. In particular, it underscores the need for domestic mined tungsten sources to meet the growing demands of fusion energy into the future. At Guardian Metal Resources, we aim to be a future supplier of domestically mined tungsten to support this ground breaking technology.”

~Oliver Friesen CEO – Guardian Metal Resources Plc 

About Oxford Sigma 

Oxford Sigma is a Fusion Technology company with a vision to tackle energy security and climate change by accelerating the commercialisation of fusion energy. Our mission is to deliver materials technology, materials solutions, and fusion design services. Oxford Sigma aims to produce advanced materials technologies, agnostic to fusion approach, for the materials ecosystem. Our fusion core materials are engineered to enable longer term operations for fusion pilot plants, with the aim of roll out to the first-of-a-kind commercial power stations. Oxford Sigma is internationally recognised as a key fusion materials and technological leader.  

Get in touch at info@oxfordsigma.com  

About Tungsten West 

Tungsten West, headquartered in Plymouth, Devon, is focused on the responsible and sustainable restart of the Hemerdon tungsten and tin mine in Devon.  The Hemerdon mine is one of the world’s largest CRIRSCO compliant tungsten resources, hosting a Mineral Resource Estimate of 351.5 Mt at 0.12% WO3 and 0.03% Sn. The AIM listed company is focused on bringing value to its stakeholders and contributing to the domestic supply of critical metals. Tungsten West is committed to promoting STEM subjects and careers in the mining sector.  

About Guardian Metal Resources 

Guardian Metal Resources plc is an AIM listed tungsten exploration and development Company that controls two co-flagship tungsten assets in mining friendly Nevada, which includes 100% ownership of Pilot Mountain which is believed to host the largest undeveloped tungsten resource in the United States of America. 

The scientific publication is found in the Fusion Engineering and Design journal. It provides the first stage proof of concept of the team’s optimisation. The publication is available here and cited as:

Anderton, M. D., et al. “Novel high temperature tritium blanket designs for confined spaces in spherical tokamak fusion reactors.” Fusion Engineering and Design 210 (2025): 114732.

The research evaluates two novel high-temperature concepts for the inboard breeder blanket design, using confined spaces typical of spherical tokamaks. Key findings include:

• A tungsten-rhenium-hafnium-carbide lithium-based design, which demonstrated the highest tritium breeding ratio (TBR) in the study. Optimised for shielding and thermal requirements, this design achieved a global TBR of 0.135 in 3D neutronics calculations using a configuration of W-24.5Re-2HfC (wt%), lithium enriched to 90% in Li-6, a thin layer of beryllium titanate, and tungsten pentaboride (W2B5) as shielding material.
• A silicon carbide and lead-lithium concept, which was also investigated as an alternative breeding configuration, by comparison achieved a global TBR of 0.048.

While the results suggest that the local TBR of these designs remains well below 1 (the minimum required TBR for self-sufficiency), especially for the lead-lithium concept, the fractional contribution they provide in boosting tritium breeding could support development of next-step practical solutions to achieving tritium self-sufficiency—a critical challenge for commercial fusion energy.

Mark Anderton, Senior Engineer at Oxford Sigma, and lead author of the paper, commented: “The study highlights the importance of innovative materials in addressing a key challenge involving the coupling of tritium breeding and radiation shielding. This collaboration has enabled us to explore new design spaces for the central column of spherical tokamaks, demonstrating how advanced materials can help reduce barriers to fusion commercialisation.”

Dr. Richard Pearson, Chief Innovator at Kyoto Fusioneering, and a co-author on the paper, added: “This research represents the essence of what Kyoto Fusioneering stands for: tackling challenging problems with a research-driven, yet application-focused approach. By working collaboratively with Oxford Sigma and UKAEA, we’ve combined complementary expertise to address a unique issue in fusion plant design, pushing known boundaries, and gaining insights that may one day lead to delivery of new technologies that will enable new avenues for fusion energy.”

Dr. Simon Kirk, Vessel and In-Vessel Systems Design Integration Lead at UKIFS, added: “This project is a great example of fusion organisations working together with a spirit of openness and meant the technical expertise from the different organisations could be combined to address the difficult challenge on centre column tritium breeding in spherical tokamaks.”

Figure 1: Change in local tritium breeding ratio and neutron flux for a variety of shielding materials and enrichment levels.

About Kyoto Fusioneering
Kyoto Fusioneering, established in 2019, is a privately funded technology startup with facilities in Tokyo and Kyoto (Japan), Reading (UK), Karlsruhe (Germany) and Seattle (USA). The company specializes in developing advanced technologies for commercial fusion power plants, such as gyrotron systems, tritium fuel cycle technologies, and breeding blankets for tritium production and power generation. Working collaboratively with public and private fusion developers across the globe, Kyoto Fusioneering’s mission is to make fusion energy the ultimate, sustainable solution for humanity’s energy needs. Explore more about KF’s vision for the future of energy at www.kyotofusioneering.com/en/ or by contacting media@kyotofusioneering.com.

About Oxford Sigma
Oxford Sigma tackles energy security and climate change by accelerating the commercialisation of fusion energy. Oxford Sigma’s mission is to deliver materials technology, materials solutions, and fusion design services in order to accelerate the commercialisation of fusion energy. Oxford Sigma is internationally recognised as a key fusion materials and technological leader within the market. Get in touch at info@oxfordsigma.com.

About STEP/ UKIFS
STEP (Spherical Tokamak for Energy Production) is a major technology and infrastructure programme that will demonstrate net energy from fusion, fuel self-sufficiency and a route to plant maintenance. UKAEA is STEP’s fusion partner and will work alongside STEP’s industry partners – one in engineering and one in construction – expected to be announced at the end of 2025/early 2026. The STEP programme is being delivered by UK Industrial Fusion Solutions Ltd (UKIFS) a wholly owned subsidiary of UKAEA Group. UKIFS will lead STEP’s integrated delivery team to design and build the prototype plant at West Burton site in Nottinghamshire, targeting first operations in 2040.

The scientific publication is found in the Fusion Engineering and Design journal. It provides the first stage proof of concept of the team’s optimisation. The publication is available here and cited as:

Anderton, et al. Fusion Engineering and Design 197 (2023) 114073

This publication supports Oxford Sigma’s recent patent on isotopic tailoring of tungsten for fusion.

Nuclear fusion has the potential to become a carbon-free, abundant energy source for both the electricity and hydrogen market of the future. A fusion power station will require the use of plasma facing components that shield the machines’ structural components from fusion plasma erosion, high temperatures and radiation damage.

One outstanding functional materials challenge for fusion energy is the plasma-facing components (PFCs) material’s selection. Fusion plasma temperatures of up to 109 °C require PFC materials to operate with temperatures in excess of 1000 °C under normal operation, and potentially higher during off-normal events. In addition, fusion plasmas produce high energy neutrons that pass through the wall material, interacting with the nuclei within the material’s structure, producing displacements and transmutation of isotopes. Tungsten is the leading PFC material choice because it meets the materials requirements for PFCs by possessing a high melting temperature (3422 °C), a high thermal conductivity, high plasma sputtering threshold, and a high temperature operational window.

A side effect of the use of tungsten in neutron irradiation environments such as fusion is the transmutation to rhenium and osmium, which are known to degrade the mechanical and thermal properties. In Oxford Sigma’s research, nuclear simulations were used to investigate a strategy of selective isotopic enrichment and/or depletion of tungsten isotopes to supress the formation of rhenium and osmium in a representative first-wall monoblock design. The research found that rhenium and osmium production can be reduced by up to three orders of magnitude compared to natural tungsten by depleting tungsten-186 isotope. This work is part of a wider strategy within Oxford Sigma to develop material solutions for fusion power stations.

“Oxford Sigma is striving to provide optimisations for issues which present significant challenges to the deployment of commercial fusion energy. This research is a step towards improving component lifetimes and reducing waste in future fusion reactors, thus making fusion more sustainable commercial option.”

~ Mark Anderton, Nuclear Engineer, Oxford Sigma.

“Novel materials are required to tackle the extreme conditions in fusion reactors. This proof-of-concept study undertaken in collaboration with Oxford Sigma explores an exciting avenue for supressing the production of detrimental elements under irradiation“

~ Dr Matthew Lloyd, Research Fellow at University of Birmingham.

Oxford Sigma tackles energy security and climate change by accelerating the commercialisation of fusion energy. Oxford Sigma’s mission is to deliver materials technology, materials solutions, and fusion design services in order to accelerate the commercialisation of fusion energy. Oxford Sigma is internationally recognised as a key fusion materials and technological leader within the market.

Get in touch at info@oxfordsigma.com

Oxford Sigma is contributing to the publication of the upcoming American Society of Mechanical Engineers (ASME)’s Boiler & Pressure Vessel Code (BPVC) Section III Division 4 “Fusion Energy Devices”, which will be published in July 2023, that provides a development pathway for codes and standards in fusion energy. The peer-reviewed paper by Dr Davis provides a rationale for this need to develop new methods for tomorrow’s fusion power stations in line with ASME BPVC codes and standards [1].

A nuclear fusion power station will be constructed out of materials that will be used to develop components that will perform multiple functions. These functions could be structural, magnetic, thermal, nuclear, fuel production, optical, or radiation shielding. If the failure of any (or multiple) of these functions leads to a safety concern to the environment, workers, or members of the public, then a national regulator will impose assessments to determine that adequate mitigation schemes are in place to either reduce or remove the hazard. The purpose of codes and standards is to establish national or international criteria based on state-of-the-art knowledge, experience, and experimental feedback from facilities to ensure structural integrity is maintained.

[1] T. Davis, “The need for codes and standards in nuclear fusion energy”, Journal of Fusion Energy, 42, 13, 2013, https://doi.org/10.1007/s10894-023-00350-2

About Oxford Sigma

Oxford Sigma tackles energy security and climate change by accelerating the commercialisation of fusion energy. Oxford Sigma’s mission is to deliver materials technology, materials solutions, and fusion design services in order to accelerate the commercialisation of fusion energy. Oxford Sigma is internationally recognised as a key fusion materials and technological leader within the market. The company operates in the United States, United Kingdom, European Union, Canada, and Japan.

Get in touch at info@oxfordsigma.com

Dr Thomas Davis has published a paper in the Journal of Nuclear Materials entitled, ‘Nanocluster evolution and mechanical properties of ion irradiated T91 ferritic-martensitic steel’.

The T91 grade and similar 9Cr tempered-martensitic steels (also known as ferritic-martensitic) are leading candidate structural alloys for fast fission nuclear and fusion power reactors. Grade 91 (referred hereafter as T91) steel is a candidate for sodium and lead/lead-bismuth cooled advanced nuclear reactors. Similar reduced activation variants are candidates for structural components in future fusion power reactors.

Ion irradiation has been used to investigate the radiation-induced precipitation of nanoclusters and changes in mechanical properties of commercial-grade T91 ferritic-martensitic steel irradiated with Fe4+ ions up to 4.10 dpa at 301 – 311 °C (using the Dalton Cambrian Facility). The use of atom probe tomography and nanoindentation, when applied in tandem, have shown to provide an insight into how radiation-induced microstructural effects can explain the observed changes in mechanical properties.

Access the paper here.

Davis & Musgrove Ltd develops novel technologies for fusion energy, holds expertise in advanced nuclear energy, and supports the defence industry. We also provide technical and regulatory-based consultancy. We are expanding at a fast pace in the energy and defence sectors. Through collaboration with industry, academia, and government, the company has expanded into patent and product development in fusion technology, as well as expanding its services into defence & energy strategy.

Please do get in touch at info@oxfordsigma.com

Dr Thomas Davis has co-authored, with fellow researchers in the field, a published paper in Energy Policy entitled ‘Re-examining the role of nuclear fusion in a renewables-based energy mix.’ Fusion energy is often regarded as a long-term solution to the world’s energy needs. However, even after solving the critical research challenges, engineering and materials science will still impose significant constraints on the characteristics of a fusion power plant. This paper re-examines the role of nuclear fusion in a renewables-based energy mix.

Access the paper here.

Davis & Musgrove Ltd develops novel technologies for fusion energy, holds expertise in advanced nuclear energy, and supports the defence industry. We also provide technical and regulatory-based consultancy. We are expanding at a fast pace in the energy and defence sectors. Through collaboration with industry, academia, and government, the company has expanded into patent and product development in fusion technology, as well as expanding its services into defence & energy strategy.

Please do get in touch at info@oxfordsigma.com

The paper evaluates and assesses how: a) the Office for Nuclear Regulation (ONR)’s formal approval could serve as a catalyst in compelling countries in the Middle East, South East Asia, Africa, South America, and Europe to purchase, either independently or via Chinese state loans, Chinese nuclear power; and b) Chinese strategic leverage over the UK and the national security implications related to the financial and construction approval for the UK Hualong One nuclear power station on British soil.

Read the full report here.

The Royal United Services Institute (RUSI) is the world’s oldest and the UK’s leading defence and security think tank. Now its ninth year, the RUSI UK PONI Annual Conference is the premier national forum for the nuclear policy community to consider salient issues in the field and promote the emergence of a new generation of expertise in academia, industry, government, and the military.

Davis & Musgrove Ltd develops novel technologies for fusion energy, holds expertise in advanced nuclear energy, and supports the defence industry. We also provide technical and regulatory-based consultancy. We are expanding at a fast pace in the energy and defence sectors. Through collaboration with industry, academia, and government, the company has expanded into patent and product development in fusion technology, as well as expanding its services into defence & energy strategy.

Please do get in touch at info@oxfordsigma.com

Dr Thomas Davis has published a paper with Materialia entitled, ‘Atom probe characterisation of segregation driven Cu and Mn–Ni–Si co-precipitation in neutron irradiated T91 tempered-martensitic steel’.

The T91 grade and similar 9Cr tempered-martensitic steels (also known as ferritic-martensitic) are leading candidate structural alloys for fast fission nuclear and fusion power reactors. Grade 91 (referred hereafter as T91) steel is a candidate for sodium and lead/lead-bismuth cooled advanced nuclear reactors. Similar reduced activation variants are candidates for structural components in future fusion power reactors. The attractive properties of T91 steels for these applications include: a) excellent void swelling resistance; b) high thermal conductivity and low thermal expansion; c) existing supply chain for steels widely used in boiler tubes, heat exchangers and piping and; d) American Society of Mechanical Engineers (ASME) BPVC Section III Division 5 nuclear code qualification. At low temperatures (300–400 °C) neutron irradiation hardens and embrittles these steels, therefore it is important to investigate the origin of this mode of life limiting property degradation. Neutron irradiation drives microstructural and microchemical evolutions in TMS, like T91, which have detrimental effects on the mechanical properties, thus limiting the lifetime and performance of reactor structural components.

This study has provided an insight into the MNSP compositions, volume fractions and sizes, which may contribute to a better understanding of the embrittlement of T91 steel. Moreover, this study builds upon the extensive understanding of precipitation in RPV steels and corresponding much more limited Fe–Cr alloy systems.

The post neutron irradiation examination was conducted at the Microscopy and Characterization Suite located at the Center for Advanced Energy Studies (CAES) with the support from the Nuclear Science User Facility Department of Energy funding programme. 

Access the paper here.

Davis & Musgrove Ltd develops novel technologies for fusion energy, holds expertise in advanced nuclear energy, and supports the defence industry. We also provide technical and regulatory-based consultancy. We are expanding at a fast pace in the energy and defence sectors. Through collaboration with industry, academia, and government, the company has expanded into patent and product development in fusion technology, as well as expanding its services into defence & energy strategy.

Please do get in touch at info@oxfordsigma.com

For any country seeking to build new nuclear power stations, there is only one player currently offering a complete package; Rosatom., the Russian state-owned nuclear utility company. Rosatom provides a full service that includes the design, commissioning, building, operation, decommissioning, provision of training to regulators and engineers, provision of solutions for nuclear waste, and provision of full financial packages. In other words, Rosatom provides a product that covers the whole nuclear fuel cycle. The United States, United Kingdom, France, South Korea, Japan and China are not prepared to offer such a complete nuclear export package.

The sphere of influence that Russia is building around the Eastern European, Middle Eastern, and Asian countries through their deployments of nuclear reactors should be cautiously analysed. Furthermore, if we investigate long-term nuclear development, Generation IV nuclear reactors will become the dominant technology for energy production. Russia has aligned itself to be the main player in the research, development, and innovation behind such designs, which will allow it to become a pillar in the global nuclear export market.

The publication explores how Russia’s nuclear export strategy could enable a diplomatic advantage, as the Russian nuclear power stations offered will operate for at least 60 years. For the first time, this talk will discuss how we are on the cusp of observing Russia’s bleeding edge research in Generation IV nuclear reactors; the result of this could enable Russia to become a significant influencer in geopolitical issues via its deployment of these Generation IV reactors over the next 50 to 150 years.

The Royal United Services Institute (RUSI) is the world’s oldest and the UK’s leading defence and security think tank. Now its ninth year, the RUSI UK PONI Annual Conference is the premier national forum for the nuclear policy community to consider salient issues in the field and promote the emergence of a new generation of expertise in academia, industry, government, and the military.

Davis & Musgrove Ltd develops novel technologies for fusion energy, holds expertise in advanced nuclear energy, and supports the defence industry. We also provide technical and regulatory-based consultancy. We are expanding at a fast pace in the energy and defence sectors. Through collaboration with industry, academia, and government, the company has expanded into patent and product development in fusion technology, as well as expanding its services into defence & energy strategy.

Please do get in touch at info@oxfordsigma.com