Multi-million-pound investment to fast-track fusion fuel development

10/03/2025

The UK Atomic Energy Authority (UKAEA)’s £200 million Lithium Breeding Tritium Innovation (LIBRTI) programme has announced a series of significant steps to advance fusion energy development.

The announcement aligns with the UK Department for Energy Security and Net Zero’s recent support for the nation’s fusion programme and budget plans for 2025/2026.

Part of the broader Fusion Futures initiative, LIBRTI focuses on pioneering fusion fuel advancements and stimulating general industry capacity through international collaboration.

Over its four-year span, the programme aims to demonstrate controlled tritium breeding, a critical step for future fusion power plants.

Future fusion power plants will rely on two hydrogen isotopes, deuterium and tritium, to produce energy. Deuterium can be readily extracted from seawater. Tritium, however, is scarce in supply, necessitating the development of methods to produce it sustainably.

To address this challenge, tritium must be produced (or ‘bred’) in a lithium-containing blanket that surrounds the fusion reaction.

This ‘breeder blanket’ will perform several tasks:

Tritium production: reacting with high-energy neutrons produced during fusion to generate tritium.
Heat absorption: capturing the immense heat generated by fusion reactions for energy conversion.
Act as a shield: protecting the machine’s components from radiation damage.

By ensuring a continuous supply of tritium for the fusion machine’s operations, the breeder blanket enables a self-sustaining fuel cycle.

As part of this effort, UKAEA intends to purchase a neutron source, which will form the backbone of a first-of-a-kind test-bed facility to be built at Culham Campus in Oxfordshire.

Shine Technologies, USA, is expected to deliver a 14 MeV deuterium-tritium fusion system to provide the LIBRTI neutron source in 2027.

John Norton, LIBRTI Director at UKAEA, explained: “The neutron source selected shall provide neutrons of the same energy as those emitted from a fusion machine, enabling LIBRTI to experiment with a wide range of materials and engineering configurations to shape and advance the breeding models required for next-step blanket designs.”

Greg Piefer, CEO of Shine Technologies, said: “Our partnership with UKAEA’s LIBRTI programme is a key milestone for fusion energy. Today, our systems are already achieving up to 50 trillion fusion reactions per second, which makes them the world’s brightest steady-state deuterium-tritium neutron sources. These fusion spectrum neutrons are essential to validate tritium breeding materials critical for scalable fusion energy systems. We are excited to work with UKAEA to develop next-generation fusion solutions to help pave the way to clean, abundant energy.”

UKAEA will also provide £9 million of funding for 12 small-scale tritium breeding and digital simulation experiments. Each of the 12 experimental and digital projects is expected to run until March 2026. Outcomes are expected to include new tritium transport models, the development of novel breeder materials and diagnostics, and digital platforms for the test-bed facility.

Among them, Amentum has won an £800,000 contract from UKAEA to develop a liquid lithium breeder system digital twin.

Stuart Codling, Amentum’s Group Director, Global Fusion Power, said: “Building on our expertise in breeder systems, physics modelling and system architecture, we will develop a digital twin that will help with the design, build, operation and maintenance of the LIBRTI facility.

“Liquid lithium presents several unique challenges and significant unknowns, so experimental research is needed to fill large gaps in the available data.

“The first step will be to create a digital model to support the design of a lithium breeder system by predicting corrosion rates, tritium breeding efficiency and purification system performance. As LIBRTI progresses and new codes and data become available, new capabilities will be integrated into the system. The end goal is to integrate two-way data flow that will support a true digital twin once LIBRTI is operational.”

DigiLab, a leading UK artificial intelligence (AI) company, will support the project by providing its Uncertainty Engine software to integrate the latest machine learning and uncertainty quantification capabilities into the model.

A comprehensive digital strategy for the programme has been developed. The resultant digital platform includes a Building Information Management (BIM) system that will work in tandem with a multiphysics simulation model.

This digital platform will enable the programme to replicate performance and ensure accurate modelling and optimisation for future designs of tritium breeder blanket systems.

Amanda Quadling, Executive Director for Fusion Fundamental Research and Materials Science at UKAEA and Senior Responsible Owner for LIBRTI, concluded: “We aim to move from a science experiment to providing the supply chain with the confidence needed to support future fusion power plants. The engineering scale experimental results combined with a robust digital platform offer powerful ways to design and substantiate future breeder systems for industrial use.”

https://ccfe.ukaea.uk/programmes/fusion-futures/librti

<< Back