UK-based Tokamak Energy has presented the first details of the high-field spherical tokamak at the Annual Meeting of the American Physical Society (APS) Division of Plasma Physics in Atlanta, Georgia.
Tokamak Energy is designing a pilot plant capable of generating 800 MW of fusion power and 85 MW of net electricity. The plant will include a complete set of new generation high temperature superconducting (HTS) magnets to confine and control the deuterium and tritium hydrogen fuel in a plasma many times hotter than the centre of the sun. Initial designs are for the tokamak to have an aspect ratio of 2.0, plasma major radius of 4.25 metres and a magnetic field of 4.25 Tesla, as well as a liquid lithium tritium breeding blanket.
Tokamak Energy was founded in 2009 as a spin-off from UK Atomic Energy Authority (UKAEA). Its US subsidiary, Tokamak Energy Inc, was established in 2019. In 2022, Tokamak Energy achieved a world-first by reaching a plasma temperature of 100m degrees Celsius in its ST40 spherical tokamak. This is the threshold required for commercial fusion energy and the highest temperature ever achieved in a privately funded spherical tokamak. Tokamak Energy is the only private company with more than 10 years’ experience of designing, building and operating tokamaks.
Tokamak Inc was one of eight private companies awarded a grant in 2023 as part of the US Department of Energy’s (DOE’s) $46m Milestone Based Fusion Development Program. This programme, based on the Bold Decadal Vision for Commercial Fusion Energy announced by the White house in 2022, provides support for private companies to partner with US national laboratories and universities, with the overall aim of pilot-scale demonstration of fusion energy in the 2030s. US support for fusion was continued in June with the release of the DOE Fusion Energy Strategy 2024. Tokamak Inc has received seven previous awards through the US Innovation Network for Fusion Energy (INFUSE) programme.
The paper presented at APS, Early design workflow and progress of Tokamak Energy’s high-field spherical tokamak fusion pilot plant for the US DOE Milestone-Based Fusion Development Program, was delivered by Erik Maartensson.
It overviews Tokamak Energy’s (TE) contribution to the US Milestone-Based Fusion Development Program. Collaborating with US partners, TE will deliver a pre-conceptual design for a fusion pilot plant (FPP) based on a high-field spherical tokamak with high-temperature superconducting magnets. The focus is on the early-stage design workflow and the current state of the project. It discusses TE’s emphasis on integration across all sub-systems and its influence on the overall design and proceeds to show the state of both engineering and physics work.
The starting point is PyTOK, an in-house whole plant systems code, which finds optimal design points across a range of parameters, whilst enforcing engineering self-consistency. A favourable design is taken into a rapid engineering and physics workflow, where the team assesses it more in-depth for up to two weeks. The assessments include neutronics for nuclear heating and tritium breeding ratio, initial plasma scenario and operating point analyses, magnet cage optimisation and plasma exhaust checks. “By involving the entire team at this early stage, and not fully relying on an integrated code to analyse the design points, we ensure that an integrated and coherent device is carried forward to the next level of fidelity,” the paper says.
Michael Ginsberg, President of Tokamak Energy Inc, said: “The first design details of our high-field spherical tokamak created great excitement at the prestigious APS conference. We are delighted by the reception from an expert crowd and energised on our mission to demonstrate net power from this pilot plant in the mid-2030s, paving the way for globally deployable carbon-free fusion energy. We now look forward to working with our partners in the U.S. to evolve and progress this design.”
