Methodology
How the edition was made: methods, the model card, the evidence cut and its age, the acceptance record and the glossary.
Contents
- ·Edition home
- ·Executive summary
- 1Fusion is an experiment record and a fuel-cycle question
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5First-plant fuel and licence set the pace
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- BData appendix
- CReferences and record
- ·Complete edition, for print
A.1Methods
The global baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.
| No. | Derivation | Calculation | Result |
|---|---|---|---|
| (1) | Target gain of the December 2022 NIF shot | 3.15 ÷ 2.05 | 1.54 |
| (2) | Start of deuterium-tritium operation in the 2016 ITER plan implied by a four-year delay to 2039 | 2039 minus 4 | 2035 |
| (3) | Average fusion power over the JET record pulse | 69 MJ ÷ 5 s | about 14 MW |
| (4) | Ratio of private funding in 12 months to July 2026 to the 2025 figure | 4.48 ÷ 2.64 | about 1.7 times |
| Strength | Definition |
|---|---|
| STRONG | a disruption in the source system has historically changed the target system’s service or output within one season, in more than one region |
| MODERATE | an effect is documented but buffered or slower |
| WEAK | an effect is plausible but not documented at global scale |
| Label | Rule |
|---|---|
| Reported | value as issued by its source, with year |
| Inferred | reasoned from cited evidence; never a measurement |
| Estimated | Nexus analytical value with stated method |
| Scenario | conditional on stated assumptions |
| Expert input | structured editorial judgement awaiting evidence |
A.2Model card, Fusion System Model v0
- Model ID
- MDL-XT14-FUSION · v0.1
- Purpose
- represent fusion and frontier energy as infrastructure coupled to energy, fuel supply, materials, finance, workforce and licensing
- Family
- graph-based system of systems
- Inputs
- the cited sources of this edition; no proprietary data
- Method
- expert-specified coupling strengths (STRONG · MODERATE · WEAK) from assessments and analogue events
- Validation
- none yet, first validation against federation evidence in 2027
- Uncertainty
- qualitative; strengths are hypotheses, not measurements
- Domain of validity
- global scale; not for asset-, site- or country-level use
- Reproducibility
- strength table and sources published in this edition
20couplings
typed in v0
0strong
documented within one season
0moderate
documented, buffered
20weak
plausible, undocumented
A.3The baseline evidence cut
Every Nexus edition is published from a frozen evidence cut. The global baseline cut is documentary: it pins the exact edition of every source cited. Federation cuts begin with the first national Foundry cuts in 2027.
- Cut ID
- DC-XTECH-FUSION-GLOBAL-2026-B0
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 46 cited sources, each at the edition and access date in the references
- Model runs
- none at baseline, analytical values are stated with their method
- Digest
- computed at freeze and recorded in the publication record
- Supersedes
- nothing, first cut of the series
- Superseded by
- the 2027 fusion annual cut
Lineage
- 01
source edition
- 02
pinned citation
- 03
finding
- 04
page
- 05
publication record
| Element | Baseline 2026 | 2027 global annual |
|---|---|---|
| Sources | cited global publications, pinned by edition | national, regional and sector cuts through one graph |
| Analysis | stated methods and editorial estimates | typed analysis specifications |
| Models | Fusion System Model v0 specification | model runs with receipts |
| Findings | twelve baseline findings | findings re-bound to federation evidence |
| Review | five passes scheduled | five passes on the exact digest |
A.4Evidence age and coverage
A 2026 global edition rests on evidence observed in many different years. This page shows each time base, so that no single year label hides older evidence.
| Indicator | Observed | Released | Cadence | Next release |
|---|---|---|---|---|
| NIF record shot | 2025 | Apr 2025 | per event | refurbished shots |
| JET energy record | 2023 | Oct 2023 · Feb 2024 | one-off | ITER results |
| WEST and EAST durations | 2025 | Jan to Feb 2025 | per event | next campaigns |
| ITER baseline | 2026 | page read 2026-11-03 | periodic | next Council update |
| Industry survey | 2026 | Jul 2026 | annual | July 2027 |
| US regulator rule | 2026 | Feb 2026 | per rule | final rule |
| UK strategy | 2026 | Mar 2026 | periodic | EN-8 draft |
| Tritium supply analysis | 2018 | 2018 · 2025 commentary | one-off | new studies |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Experiments | GOOD | power and gain on a plant basis |
| Fuel cycle | THIN | tritium and lithium-6 volumes |
| Governance | PARTIAL | final rules and national plans |
| Investment | PARTIAL | public funding totals |
| Energy | THIN | electricity delivered to a grid |
| Materials | THIN | component lifetimes |
| Skills | THIN | workforce numbers |
| Frontier energy beyond fusion | THIN | covered by other editions |
| Field | Source that would fill it | Blocker |
|---|---|---|
| Electricity delivered to a grid from fusion | plant operators and grid operators | no plant in operation in the sources read; company plans only2423 |
| Facility electricity per NIF shot or per WEST pulse | laboratory facility reports | not on the pages read; gain counts laser energy on target only5 |
| Global tritium inventory and start-up demand on a common basis | IAEA, national tritium programmes, peer-reviewed supply studies | one conference analysis and one commentary read; estimates differ2022 |
| Lithium-6 enrichment capacity and demand | enrichment operators, national laboratories | one company presentation read; a 2026 preprint seen in search only2133 |
| ITER cost of the 2024 baseline | ITER Council documents | not on the page read; a figure appears only in search summaries26 |
| SPARC first plasma date and status | Commonwealth Fusion Systems and its regulators | date reported in search summaries only; no primary page opened29 |
| Commonwealth Fusion Systems offtake terms with Google | company releases | seen in search summaries only; terms not disclosed27 |
| Helion Microsoft agreement terms | company releases | release page returned a block; figure taken from the company page read2824 |
| Fusion Industry Association 2026 report from the report itself | FIA report30 | report page returned an error; figures come from a news service10 |
| IAEA World Fusion Outlook 2025 from the report itself | IAEA publication31 | publication page returned a payment error; figures come from news9 |
| Status of the final US rule on fusion machines | Federal Register and NRC | proposed rule read; no final rule located at evidence close14 |
| Status of the EU fusion strategy | European Commission | call for evidence read; no strategy text located18 |
| Public funding totals by country | ministries, OECD, national audit offices | not consolidated; UK, Germany and China figures are on different bases151619 |
| Workforce size and fabrication capacity by country | national statistics, industry surveys | not retrieved; capability rung stays LISTED |
A.5Evidence cards, two anchor sources
Published on the annual report site of Lawrence Livermore National Laboratory for 2025. One facility. Role: binds INF-001 and the gain tiles. Coverage: laser-driven inertial confinement.
EVD-XT14-001
Record fusion yield and gain at the National Ignition Facility5
Conference paper of the UK Atomic Energy Authority, 2018. One-off. Role: binds MIN-006. Coverage: heavy-water reactors and scenarios to 2055.
EVD-XT14-002
Global supply of tritium for fusion R and D from heavy-water reactors20
| Dimension | EVD-XT14-001 | EVD-XT14-002 |
|---|---|---|
| Completeness | one facility; one shot series | scenarios to 2055 on 2018 data |
| Timeliness | annual report for 2025 | about eight years old |
| Revision | yearly reports | revised from an earlier work |
| Method transparency | yield and laser energy stated | scenario assumptions stated |
| External validation | laboratory report; journal papers for earlier shots | conference review |
Evidence cards to follow in 2027
A.6Publication acceptance record
Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.
| Group | Area | Items | Pass | N/A | Pending |
|---|---|---|---|---|---|
| D1 | Identity and scope | 8 | 8 | 0 | 0 |
| D2 | Source and data | 12 | 9 | 1 | 2 |
| D3 | Analysis and models | 12 | 3 | 8 | 1 |
| D4 | Findings and claims | 9 | 8 | 0 | 1 |
| D5 | Figures, tables, maps | 10 | 6 | 2 | 2 |
| D6 | Editorial and citations | 10 | 8 | 0 | 2 |
| D7 | Review and approval | 13 | 0 | 0 | 13 |
| D8 | Artefact and design | 12 | 7 | 0 | 5 |
| D9 | Registry and release | 9 | 0 | 0 | 9 |
Publication gate
- Conditions met
- 14 of 23 at evidence close
- Blocking problems
- none recorded
- Open conditions
- reviews, approval of the exact digest, deposit, registry pointer
Not applicable at baseline
- Model runs
- first runs in Q1 2027
- Maps
- plates in Q2 2027
- Waivers
- none
A.7Status words
| Status | What it means |
|---|---|
| Observed | Measured directly and published by the source. |
| Reported | Published statistics of an official or institutional source. |
| Declared | Stated by the body concerned; not independently measured. |
| Estimated | A Nexus estimate from cited evidence, with its method in Annex A. |
| Modelled | Produced by a stated model from cited inputs. |
| Inferred | Reasoned from cited evidence; not measured. |
| Forecast | A projection by the cited source. |
| Simulated | A simulation result under stated assumptions. |
| Scenario | A conditional statement under stated assumptions; never a prediction. |
| Expert input | Expert judgement, recorded with its basis. |
| Candidate | Proposed for a later edition; not yet evidence. |
| Evidence-quality levels (EQL 1 to 5) grade the source behind a value; they are not a score of the subject. | |
A.8How the edition is made, released and corrected
Every edition is built from a sealed evidence cut, reviewed under three keys, signed and deposited before any site shows it as published; corrections go to Nexus Standards as change proposals and feed the next cut.
| Step | What happens | Source |
|---|---|---|
| 01 Evidence arrives from the pillars | Foundry seals observations and indicator series, Universe hands over after-action and scenario findings, and contributions are screened at every gateway, including this site’s. | |
| 02 The cut is sealed | On the cut date the evidence is pinned under one identifier, so anyone can rebuild the edition from exactly what it was built on. | |
| 03 The edition is assembled | The edition is drafted from its template and content pack. Agents may draft; they never publish and never decide. | |
| 04 The keys turn | At the publisher of record the truth key comes first: every value is checked against its source or stated method before the meaning and capital keys turn. No edition moves on until every key has been turned by a named steward. | |
| 05 The gate opens | A named approver releases one exact digest of the edition; any change after this point is a new version, never a silent edit. | |
| 06 Signed and deposited | The PDF, the web edition and the data bundle are signed together with a manifest and an RO-Crate description, and deposited on Zenodo with a concept and a version DOI. | |
| 07 Published on its desk’s site | Only then does the edition show as published on its desk’s Reports site, and the Collection lists it as a part. | |
| 08 Corrections go to Standards | Method and correction findings go to Nexus Standards as change proposals; citations, corrections and new contributions feed the next evidence cut. |
A teaching model of the process, not a forecast and not a record of any run; dates and counts on this page come from the programme record. Sources: Reports governance at GCRI Canada (2026); Zenodo, repository of record for Reports deposits (2026).
Lifecycle, one state at a time: Draft, Computed, Evidence bound, Reviewed, Approved for release, Published, Corrected, Superseded. This edition is a draft.
A.9Glossary and abbreviations
| Term | Meaning |
|---|---|
| Baseline Edition | the inaugural annual edition that fixes the reference state for the series |
| WEFH+B | water, energy, food, health and biodiversity, the national nexus core |
| Coupling | a typed dependency through which one system transmits to another |
| Protection gap | the share of losses not covered by insurance |
| Capability ladder | LISTED → EXISTS → ADEQUATE → TESTED → DEMONSTRATED |
| EQL | evidence-quality level, 1–5 |
| Evidence cut | a frozen resolution of exact sources and versions |
| NNC · NLC · NWG | National Nexus Consortium · National Leadership Council · National Working Groups |
| Abbreviation | Expansion |
|---|---|
| CANDU | Canada Deuterium Uranium heavy-water reactor |
| D-T | deuterium-tritium |
| EAST | Experimental Advanced Superconducting Tokamak |
| FIA | Fusion Industry Association |
| IAEA | International Atomic Energy Agency |
| ITER | international fusion research project in France |
| JET | Joint European Torus |
| NIF | National Ignition Facility |
| NRC | US Nuclear Regulatory Commission |
| STEP | Spherical Tokamak for Energy Production |
| TBR | tritium breeding ratio |
| WEST | Tungsten Environment in Steady-state Tokamak |
A.10Technical annex
| Item | Annex | Contents | Status |
|---|---|---|---|
| A.1 | Indicator definitions | the global indicator set, with units and sources | IN THIS EDITION |
| A.2 | Coupling strengths | the twenty-cell matrix and its rationale | IN THIS EDITION |
| A.3 | Scenario specification | SCN-XT14-FUE-01 assumptions and signposts | IN THIS EDITION |
| A.4 | Capability placements | rung evidence for fifteen functions | IN THIS EDITION |
| A.5 | Model diagnostics | first runs and validation | 2027 |
| A.6 | Sensitivity analyses | influence of coupling strengths | 2027 |
| A.7 | Cluster notes | cards for the major fusion device and fuel-cycle clusters | 2027 |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition: target gain
- Construct
- fusion energy produced divided by the laser energy delivered to the target
- Unit
- times
- Method
- yield and laser energy as reported by the laboratory for a single shot
- Source
- Lawrence Livermore National Laboratory annual report5
- Uncertainty
- no uncertainty is stated on the page read
- Known limits
- laser energy on target only; facility electricity is not included; one facility
Notes
Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references
- 24Helion (ed.), Orion, the first fusion power plant (company page; Malaga, Washington; construction from 2025; initial operations stated for 2028; Microsoft agreement for 50 MW; a vendor announcement, weak evidence). Helion Energy, Everett. Observation year 2026. Accessed 2026-11-03.back
- 23Commonwealth Fusion Systems and Eni (eds.), Eni and CFS sign over USD 1 billion power purchase agreement (joint company release of 22 September 2025; 400 MW ARC plant in Chesterfield County, Virginia; grid connection in the early 2030s; a vendor announcement, weak evidence). Commonwealth Fusion Systems, Devens. Observation year 2025. Accessed 2026-11-03.back
- 5Lawrence Livermore National Laboratory (ed.), National Ignition Facility 2025 (annual report page; 8.6 MJ on 7 April 2025 from 2.08 MJ delivered, target gain 4.13; refurbishment and enhanced yield capability to 2.6 MJ). Lawrence Livermore National Laboratory, Livermore. Observation year 2025. Accessed 2026-11-03.back
- 20Coleman, M. and Kovari, M., Global supply of tritium for fusion R and D from heavy water reactors (conference paper, UK Atomic Energy Authority; abstract and introduction read from the PDF; 0 to 27.7 kg available in 2055 across scenarios; 7.4 kg for a demonstration reactor in 2055 in one case). UK Atomic Energy Authority, Abingdon. Observation year 2018. Accessed 2026-11-03.back
- 22Theiding, T., Tritium: a few kilograms can make or break nuclear fusion (policy blog post of 6 March 2025; about 25 kg of civilian tritium in 2024; a student fellow commentary, weak evidence). Kleinman Center for Energy Policy, University of Pennsylvania, Philadelphia. Observation year 2024. Accessed 2026-11-03.back
- 21Pearson, R.J., The availability and supply of critical natural resources for the realisation of a fusion pilot plant: fuels for fusion (presentation to the US Department of Energy fusion workshop, 1 to 3 June 2022; lithium-6 is 7.4% of natural lithium; blankets need 30 to 90%; supply effectively zero; a company presentation, weak evidence). Kyoto Fusioneering, London. Observation year 2022. Accessed 2026-11-03.back
- 33UNVERIFIED, not opened: Ward, P. and colleagues, Lithium enrichment threatens to curb fusion deployment, arXiv:2605.04707, 2026, taken from search-result summaries. arXiv, Ithaca. Observation year 2026. Accessed 2026-11-03.back
- 26UNVERIFIED, not opened: ITER Organization and press (eds.), ITER 2024 baseline additional cost of about EUR 5 billion, taken from search-result summaries. Observation year 2024. Accessed 2026-11-03.back
- 29UNVERIFIED, not opened: Commonwealth Fusion Systems (ed.), SPARC status, first plasma reported as a 2027 target, taken from search-result summaries and secondary pages. Commonwealth Fusion Systems, Devens. Observation year 2026. Accessed 2026-11-03.back
- 27UNVERIFIED, not opened: Commonwealth Fusion Systems (ed.), offtake agreement with Google for 200 MW from the Virginia ARC plant, June 2025, taken from search-result summaries. Commonwealth Fusion Systems, Devens. Observation year 2025. Accessed 2026-11-03.back
- 28UNVERIFIED, not opened: Helion (ed.), Helion secures land and begins building on the site of the first fusion power plant, release of 30 July 2025 (the release page returned a block) and the 2023 Microsoft agreement, taken from search-result summaries. Helion Energy, Everett. Observation year 2025. Accessed 2026-11-03.back
- 30UNVERIFIED, not opened: Fusion Industry Association (ed.), The Global Fusion Industry in 2026 (report page returned an error; figures read through a news service). Fusion Industry Association, Washington. Observation year 2026. Accessed 2026-11-03.back
- 10World Nuclear News (ed.), Fusion industry raised USD4.5 billion in past year, report says (14 July 2026; Fusion Industry Association 2026 survey: USD 4.48 billion in 12 months, USD 14.24 billion cumulative, 56 companies; an industry survey, weak evidence). World Nuclear Association, London. Observation year 2026. Accessed 2026-11-03.back
- 31UNVERIFIED, not opened: IAEA (ed.), World Fusion Outlook 2025 (publication page returned a payment error; figures read through news). International Atomic Energy Agency, Vienna. Observation year 2025. Accessed 2026-11-03.back
- 9World Nuclear News (ed.), Fusion entering implementation phase, says Grossi (report on the IAEA World Fusion Outlook 2025; more than 160 devices; private investment above USD 10 billion; October 2025). World Nuclear Association, London. Observation year 2025. Accessed 2026-11-03.back
- 14US Nuclear Regulatory Commission (ed.), Federal Register notice of 26 February 2026, proposed rule on regulatory framework for fusion machines (10 CFR part 30; comments due 27 May 2026; the first 100,000 of 168,363 characters were read). Office of the Federal Register, Washington. Observation year 2026. Accessed 2026-11-03.back
- 18European Commission (ed.), Commission launches call for evidence to support first-ever EU-wide fusion strategy (news item of 6 June 2025; call open to 1 July 2025; strategy then programmed for the end of 2025). Directorate-General for Energy, Brussels. Observation year 2025. Accessed 2026-11-03.back
- 15UK Department for Energy Security and Net Zero (ed.), A new energy revolution: the UK plan for delivering fusion energy (policy paper of 16 March 2026; over GBP 2.5 billion over five years; GBP 1.3 billion for STEP and UK Fusion Energy; the first 100,000 of 127,790 characters were read). UK Government, London. Observation year 2026. Accessed 2026-11-03.back
- 16Clean Energy Wire (ed.), German government pledges more than EUR 2 bln for nuclear fusion (news report of 2 October 2025; cabinet plan of 1 October 2025). Clean Energy Wire, Berlin. Observation year 2025. Accessed 2026-11-03.back
- 19American Nuclear Society (ed.), China launches fusion-focused company (news report of 30 July 2025; China Fusion Energy Co., 15 billion yuan registered capital, subsidiary of a state nuclear group; BEST tokamak in Hefei hoped for 2027). American Nuclear Society, La Grange Park. Observation year 2025. Accessed 2026-11-03.back
- 7ITER Organization (ed.), ITER in a few lines (project page; baseline reviewed by the ITER Council in November 2024; start of research operation 2034; deuterium-tritium operation 2039; Q of 10, 500 MW from 50 MW). ITER Organization, Saint-Paul-lez-Durance. Observation year 2026. Accessed 2026-11-03.back