Fusion blankets serve three primary functions: 1) breeding tritium fuel, 2) power harnessing to convert fusion energy to usable heat, and 3) shielding magnet systems from radiation damage. Liquid breeder blanket concepts include lead-lithium eutectic (PbLi), molten lithium and beryllium fluoride at eutectic composition (FLiBe), or liquid lithium (Li) as the breeding medium with self-cooled,...
The Tritium Breeder (TriBreed) demonstrator project aims to develop a prototype breeding device that will enable accurate measurements of tritium production and develop novel breeding materials. TriBreed will act as a stepping stone between previous and planned tritium breeding experiments based on low flux neutron generators (typically 10$^{10}$ n s$^{-1}$) and LIBRTI, by taking advantage of...
The efficient and accurate design of tritium breeder blankets is essential for the success of nuclear fusion reactors, playing a vital role in achieving optimal performance and safety. This study, developed within the LIBRTI programme funded by UK Atomic Energy Authority (UKAEA), introduces a comprehensive workflow that integrates parametric geometry generation, meshing, and multiphysics...
The development of breeding blankets is critical for the realization of fusion energy, as they are essential in fuel production and energy generation in fusion reactors. The pre-conceptual design for the K-DEMO blanket has commenced, with the HCCP blanket concept adopted as the reference design following the KO-EU HCCP TBM project, while other potential design options are being explored. To...
Lithium aluminate (i.e., y-LiAlO2) pellets were subjected to neutron irradiation during the TMIST-3 in-reactor experiment, which was designed to evaluate tritium release rate and speciation from various pellet designs. The TMIST-3 experiment consists of a short-term and a long-term test train to study the effects of burnup, burnup rate, and time on tritium release rate and speciation. The...
The University of Bristol and Astral Systems are establishing a tritium breeding research facility in the north of Bristol. This leverages the expertise of the University of Bristol on material manufacture and instrumentation design and Astral’s revolutionary compact neutron sources.
The facility consists of a gas management system (GMS), a breeder blanket module (BBM) and a DD neutron...
In this talk, we present the ongoing work on creating a high-fidelity digital twin of the LIBRTI facility using NVIDIA Omniverse and illustrate how design processes, real-time simulation, robotics, and visual analytics integrate to enable future operational workflows. The prototype interactive experience illustrates an example end-to-end irradiation sequence within the facility, including...
Within the context of deploying future fusion power devices, the breeder blanket system remains at a very low technology readiness level (TRL) and therefore requires substantial research and development to ensure long-term robustness, reliability, and safety. Breeder blankets are highly complex, tightly coupled systems involving neutronics, thermal hydraulics, materials behaviour, and tritium...
In order to most efficiently produce tritium from a high energy neutronic reaction, lithium dense tritium breeding materials (TBMs) are required. TBMs must operate under high temperatures and neutron radiation, whilst producing extractable tritium and being compatible with the surrounding materials. Ceramic TBMs offer material compatibility and do not suffer from magnetohydrodynamic (MHD)...
Breeding blanket designs considered for DEMO include not only materials but also technologies, whose behaviour under fusion-like conditions has not yet been tested. Therefore, it is urgent to evaluate these blankets in relevant environments, with emphasis on significant radiation levels. Looking for solutions to qualify and validate the breeding blankets, IFMIF-DONES has launched a new...
As the UK nuclear ‘renaissance’ continues apace, steels continue to demonstrate incredible versatility and performance, particularly as we consider next-generation structural materials to use in the most demanding environments ever developed. Proposed commercial fusion powerplants contain plasmas ten times hotter than the sun, with materials witnessing extreme levels of radiation damage. This...
We have undertaken tritium breeding experiments using 14.1 MeV neutron generators for irradiation of capsules filled with molten salts (ClLiF and FLiBe) at temperatures 600C - 700C. Tritium that is bred in the salt is collected by sweep gas into bubblers and then analyzed with Liquid Scintillation Counting. The collected tritium is compared to measured neutron fluences from the neutron...
Presenting on behalf of the TRIBAL consortium
The TRIBAL – Tritium Breeding to Advance LIBRTI project is a collaboration between the University of Edinburgh, Commonwealth Fusion Systems, Eni, the University of California Berkeley, and Xcimer Energy. This project was funded via the LIBRTI feeder stream projects in early 2025 and is unique in developing the FLiBe molten salt breeding blanket....
The Water-Cooled Lithium Lead (WCLL) concept is one of the reference breeding blanket options for the European Demonstration Fusion Power Reactor (DEMO) and a key focus of the joint EUROfusion and Fusion for Energy (F4E) research programme. Ensuring tritium self-sufficiency and adequate shielding performance requires robust experimental validation of neutronics predictions, together with a...
Liquid breeder-based blanket concepts have been proposed for fusion power plants around the globe. While there are ongoing projects addressing key challenges, such as flow under magnetic fields, safety, and heat transfer; the tritium breeding via neutron irradiation in flow is only scheduled to take place in over a decade from now [1] [2]. This has motivated the demonstration of flowing...
One of the priorities at Kyoto Fusioneering is breeding blanket design and build. To achieve this, we are actively developing different blanket designs in-house, working alongside UKAEA, LIBRTI, and private fusion partners. Our research and development efforts are shaped by uncertainties in both design and manufacturing processes. As a result, we established UNITY-1 -a non-nuclear integrated...
The LIBRTI program seeks to de-risk fuel-cycle technology through physical demonstrations of specific breeder concepts, and accompany this with a digital representation of the facility to enhance the understanding of any measurements obtained. Such endeavours provide a route to in-silico design and qualification of breeder blanket technologies, thereby accelerating the critical pathway to...
Predicting tritium generation, retention, and release in a breeder blanket is essential for the design of fusion experiments, reactor prototypes, and ultimately commercial systems. Sensible and reliable design choices requires close alignment between simulations and experiments overseeing a variety of processes and physical scales. Assessing the predictive accuracy of tritium transport...
In the design, construction and operation of breeder blankets, there is large uncertainty in a range of properties including the geometry, material properties, physical parameters, isotope composition and nuclear cross-sections. Uncertainty quantification (UQ) methods aim to quantify how variability in each of the properties drives variability in the performance of the system. This allows...
Tritium-producing burnable absorber rods (TPBARs) are irradiated in a commercial power plant to produce tritium for US defense purposes. The presentation will review the current state of the US tritium production program, production history that led to the present state, and discussions of a few planning scenarios for the future. The organization of the National Nuclear Security...
Solid-type tritium breeders are typically used in pebble form to ensure suitable packing behavior, stress distribution, thermal conductance, and purge gas flow. Beyond these physical characteristics, tritium release behavior is a key performance factor for breeder materials in fusion reactors. The Korea Institute of Fusion Energy (KFE) has developed the core technology for fabricating tritium...
In this work, we analyse and compare different liquid metal blanket designs that are based on alternative approaches to achieving heat balance, with a primary focus on understanding the MHD drag associated with these options. Specifically, we consider three concepts:
(i) Helium-cooled blanket: All heat is removed by helium flow, which is compressed and pumped at very high velocities through...
Liquid lithium is a candidate material for tritium breeding and as a coolant in fusion reactors. Vanadium is proposed as the corresponding structural material surrounding the liquid lithium, owing to their compatibility. However, tritium retention and transport in liquid lithium and across a lithium-vanadium interface is either ambiguous or unknown from literature, which prevents an accurate...
SHINE Technologies has been selected as the DT neutron source supplier for the LIBRTI tritium breeding test facility. As part of UKAEA’s broader Fusion Futures initiative, the LIBRTI program focuses on pioneering fusion fuel advancements and stimulating general industry capacity through international collaboration. Over its four-year span, the program aims to demonstrate controlled tritium...
The transition to commercial fusion energy hinges on robust, real-time tritium monitoring within breeder blanket systems. This work, developed under the TRI-PRISM Project and led by Kyoto Fusioneering UK in collaboration with ENEA, Canadian Nuclear Laboratories, and the University of Birmingham, presents the latest advances in hydrogen isotope permeation sensor (HPS) technology for...
Tritium breeding is an essential element of civilian fusion nuclear energy technologies development paths as it provides a crucial constituent of the plasma fuel. Fusion research and development programs need to establish tritium production in line with fusion energy technologies deployment and development requirements. Tritium, as a radioactive isotope of hydrogen can be produced by nuclear...
Neutronics plays a vital role in the design, operation, and decommissioning of nuclear facilities, requiring accurate assessments of neutron energy distributions, activation calculations, and gamma decay fields. Transport codes, either deterministic or Monte Carlo-based, are used for these assessments. Deterministic methods are faster but less detailed, while Monte Carlo-based methods, though...
The supply of tritium fuel within a tokamak design fusion reactor remains an ongoing challenge for the developing nuclear fusion industry. Tokamak-design fusion reactors will need to be self-sufficient for the supply of tritium fuel into their fusion reaction. To satisfy this self-sufficiency criteria, numerous breeder blanket concepts for tritium generation exist, with liquid lithium and...
A major challenge for fusion reactors is the production of tritium fuel for sustained fusion reactions, as well as the extraction of heat to generate electricity. Both aspects are directly linked to the breeder blanket (BB) components in a reactor. An extensive literature indicates that various blanket designs have been proposed worldwide, including solid-pebble breeders, liquid lithium-lead...
Tritium breeding blankets are essential to fuel the fusion reaction, and lithium-containing liquid metals are proposed as breeding materials since they can effectively absorb neutrons from the fusion reaction and produce tritium.1,2 However, liquid metals pose chemical challenges, e.g., high alkalinity and/or corrosiveness, which can be exacerbated by non-metallic impurities.3 Whilst...
This work presents a data-driven surrogate modeling framework developed within the LIBRTI project to enable computationally tractable full-scale tritium breeder blanket analysis. High fidelity multiphysics simulations coupling neutronics, thermal-hydraulics, and tritium transport are prohibitively expensive for system-level parametric studies due to the computational burden of resolving 3D...
As a part of LIBRTI programme, the University of Birmingham has designed and manufactured a Tritium Breeding Module (TBM). The module is required to house a solid Li2TiO3 breeder block capable of producing tritium under neutron irradiation, which can subsequently be captured using a bubbler system and quantified via liquid scintillation techniques. Helium–hydrogen purge gas (95% He, 5% H₂) is...
Recently, molten salts have been proposed for numerous applications: as coolants for advanced nuclear fission and fusion reactors, and as thermal vectors for thermal energy transfer. The characterization and understanding of the chemical behavior and mass transport of corrosion products and other solutes in the molten salt is critical for the design, licensing and operation of the various...
The deployment of new, enhanced performance, low activation, fusion-grade steels for in-vessel components such as breeder blankets can only be realised through advances in material science, industrial supply chain capability, component design and manufacturing technologies. The process of manufacturing a breeder blanket component will include many of the following steps: casting, rolling,...
This work deploys an integrated Model-Based Systems Engineering (MBSE) framework for guiding the verification and validation (V&V) of a dual-cooled lithium–lead (DCLL) breeder blanket mock-up, with a focus on neutronics, tritium behaviour and material performance under fusion-relevant irradiation. By formalising stakeholder needs and design requirements, the framework establishes a traceable...
Reliable thermal-hydraulic assessment of Helium-Cooled Pebble Bed (HCPB) breeder blankets is essential to guarantee temperature limits, tritium extraction performance, and structural integrity under fusion-relevant loads. In this work, an open-source workflow for HCPB thermal--hydraulic analysis is presented, spanning from pin-level conjugate heat transfer to system-level blanket modelling...
As part of the LIBRTI programme, the University of Birmingham is developing capability to (a) breed tritium from lithium ceramic in a metal capsule with the HF-ADNeF neutron source [1] and (b) detect tritium with a tritium bubbler and liquid scintillator system. To predict tritium activity, an OpenMC [2] model of the facility has been developed using the existing HF-ADNeF source term developed...
The reliable design and effective deployment of tritium breeding blankets are critical challenges for realizing fusion energy. The fusion neutronics group at the University of Tennessee, Knoxville (UTK) has conducted integrated research focused on evaluating fusion blanket performance using the Fusion Nuclear Science Facility (FNSF) as a testbed. This research has analyzed TBR performance...
Tokamak Energy is developing a liquid metal breeder blanket for the ST-E1 power plant. Due to spatial constraints, the blanket in a spherical tokamak can only be installed in the outboard region. The breeder material is natural lithium, while the walls are designed to be manufactured from the vanadium alloy V44.
The breeder circulates through the blanket at a very low flow rate, determined by...
The Helium Cooled Pebble Bed (HCPB) is one of the breeding blanket concepts under investigation by EUROfusion for the EU DEMO fusion reactor. The DEMO Design Criteria for In-Vessel Components (DDC-IC), currently being developed within EUROfusion, aims to reduce over-conservatism and enhance performance by employing an in-elastic design-by-analysis approach based on advanced non-linear finite...
