A multiphysics and AI-driven approach to tritium production for fusion reactors
Fusion energy promises to be the ultimate energy source: safe, virtually unlimited, and CO₂ free. But there is a critical challenge to solve: tritium.
Why is tritium so important?
Tritium is one of the two fuels required for the fusion reaction (along with deuterium). The problem is that it barely exists in nature. The entire world’s inventory would fit in a suitcase. That is why future fusion reactors must produce their own tritium using components called breeder blankets, which surround the plasma and generate tritium when neutrons interact with lithium.
Designing these systems is extraordinarily complex: it involves neutronics, heat transfer, fluid dynamics, and tritium transport, all tightly coupled. And here is the big problem: we cannot build a full reactor just to test if it works.
Our solution: bidirectional scaling methodology
At IDOM, we have developed an innovative approach combining advanced multiphysics simulation with artificial intelligence models:
Scale Up: We predict the behaviour of an entire reactor (with hundreds of elements) from detailed simulations of individual components, using surrogate models that capture the essential physics.
Scale Down: We design laboratory experiments that faithfully reproduce real reactor conditions, preserving the key dimensionless numbers that govern tritium transport.
This approach allows us to answer two fundamental questions: how will the full reactor behave? and what experiments do we need to validate it?
Open source tools
Our work relies on open source tools. We have developed PARABLANK, a parametric breeder blanket geometry generator that enables rapid exploration of different configurations. For multiphysics simulation, we use the MOOSE framework from Idaho National Laboratory (INL), where IDOM actively contributes to the development of tritium transport capabilities (TMAP8). This open source philosophy accelerates innovation and facilitates international collaboration in fusion.
The LIBRTI Programme
This work is part of LIBRTI (Lithium Breeding Research for Tritium Innovation), a strategic collaboration between UK Atomic Energy Authority and the University of Bristol, where IDOM provides multiphysics simulation and system design capabilities.
LIBRTI is key to the UK fusion programme and the development of STEP (Spherical Tokamak for Energy Production), which aims to be the first fusion reactor connected to the electricity grid.
This month, Alexandre Sureda presented as a key speaker at the LIBRTI progress meeting. He shared our progress on the LIBRTI project at UK Atomic Energy Authority with world leading experts in tritium breeding, blanket technology, and fusion reactor design.
During the event, Juan Diego Iberico and Fernando Scarafia presented their posters: “Data-Driven Surrogate Models for Multiphysics Tritium Breeding Blanket Performance Prediction” and “Open-source thermal-hydraulic assessment of the HCPB breeder blanket“, which also showcased the progress made on the project. The event was also attended by Eduard Llinás and Alya Jasmine.
Sharing our methodology with this international community of specialists reinforces the value of collaborative research in tackling fusion’s greatest challenges.
IDOM at Culham Science Centre
From our office at Culham Science Centre, the heart of UK fusion research and home to JET (the world’s largest tokamak), our team works side by side with UKAEA and leading players in the sector. Being here allows us to participate directly in Europe’s most advanced fusion ecosystem.
Proud to contribute to one of the greatest technological challenges of our generation. Fusion is not science fiction. It is engineering, and it is happening now.
