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
- 1Advanced nuclear is firm infrastructure and a delivery test
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Fuel supply gap while first-of-a-kind units are delayed
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- A.1 Methods
- A.2 Model card, Advanced nuclear System Model v0
- A.3 The baseline evidence cut
- A.4 Evidence age and coverage
- A.5 Evidence cards, two anchor sources
- A.6 Publication acceptance record
- A.7 Status words
- A.8 How the edition is made, released and corrected
- A.9 Glossary and abbreviations
- A.10 Technical annex
- 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) | Rosatom share of 2025 world enrichment capacity | 29.133 ÷ 68.076 | ≈ 42.8% |
| (2) | Ratio of Vogtle 3 and 4 cost estimate of May 2022 to the initial estimate | 30.34 ÷ 14 | ≈ 2.17 times |
| (3) | NRC review time for the Natrium permit against the initial schedule | 18 ÷ 27 | ≈ 0.67 |
| (4) | Average net capacity per operable reactor, 2025 | 405,667 ÷ 443 | ≈ 916 MWe |
| 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, Advanced nuclear System Model v0
- Model ID
- MDL-XT15-FISSION · v0.1
- Purpose
- represent advanced nuclear fission as infrastructure coupled to energy, fuel supply and enrichment, siting and waste, 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-FISSION-GLOBAL-2026-B0
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 42 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 advanced nuclear 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 | Advanced nuclear 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 |
|---|---|---|---|---|
| Fleet counts | 2025 | page read 2026-11-03 | continuous | next annual update |
| Pilot program criticality | 2026 | Jun to Jul 2026 | per event | remaining participants |
| Natrium permit | 2026 | Mar 2026 | one-off | operating licence |
| Part 53 rule | 2026 | Mar 2026 | one-off | first application |
| HALEU page | 2024 | Dec 2024 | periodic | new DOE update |
| Enrichment capacity | 2025 | fuel report 2025 | annual | next report |
| Reactor cost records | 2022 to 2026 | May 2022 to Feb 2026 | per event | new estimates |
| Waste volume study | 2022 | May 2022 | one-off | new studies |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Reactors | PARTIAL | operating record of advanced units |
| Licensing | GOOD | review times outside the United States |
| Fuel | PARTIAL | HALEU output by year |
| Cost | PARTIAL | delivered cost of advanced units |
| Waste | THIN | common basis for comparison |
| Supply chain | THIN | fabrication capacity |
| Skills | THIN | workforce numbers |
| Climate role | THIN | life-cycle emissions |
| Field | Source that would fill it | Blocker |
|---|---|---|
| Delivered cost of first-of-a-kind advanced and small reactors | owners, national audit bodies, regulator filings | no advanced unit is complete; only modelled costs and large-unit records were read151725 |
| HALEU production against demand, by year | DOE, Centrus, national statistics | one DOE page read; output by year not found11 |
| World nuclear capacity projections for 2050 from the IAEA report | IAEA Energy, Electricity and Nuclear Power Estimates | the report page was not opened; figures appear only in trade summaries2 |
| Executive Order 14301 text on the test reactor goal | White House presidential actions | the page address returned not found; the goal comes from a society report56 |
| Operating record of any commercial advanced reactor | operators and regulators | none found operating at baseline |
| Linglong One commissioning and commercial operation | CNNC and national regulator releases | the profile page says commissioning is expected during 2026; no confirmation was found18 |
| Count of small reactor designs and projects | OECD NEA dashboard, IAEA booklet | the dashboard page returned a service error; the booklet was not opened2942 |
| Uranium resources and demand projections | OECD NEA and IAEA Red Book | the page returned forbidden30 |
| Life-cycle emissions of nuclear generation | UNECE, IPCC | both pages returned forbidden or could not be read3536 |
| Cooling-water and land use of new sites | site licence applications and environmental reports | not retrieved |
| Fabrication capacity and materials dependence by country | industry and trade statistics | not retrieved |
| Nuclear workforce size and skills gaps | national statistics, OECD, industry surveys | not retrieved; capability rung stays LISTED |
| Regulator pages for NuScale, Kairos and Darlington | NRC, CNSC, OPG | pages returned not found or forbidden; figures come from country profiles14313839 |
| Capability rungs beyond licensing and planning | agencies, operators, laboratories | not reviewed |
A.5Evidence cards, two anchor sources
Issued by the US Department of Energy in March 2026. One-off. Role: binds INF-003 and the licensing tile. Coverage: one sodium-cooled reactor at one site.
EVD-XT15-001
Natrium construction permit release8
Compiled by the World Nuclear Association from its 2025 fuel report. Annual. Role: binds TRD-007 and the supply tile. Coverage: operator capacity for 2022, 2025 and a 2030 projection.
EVD-XT15-002
Uranium enrichment capacity table12
| Dimension | EVD-XT15-001 | EVD-XT15-002 |
|---|---|---|
| Completeness | one reactor; scope of permit stated | four operators plus others; China estimated |
| Timeliness | issued within days of the permit | annual; 2025 data |
| Revision | no correction seen | annual updates |
| Method transparency | review process described by the agency | compiled data; China method stated |
| External validation | regulator decision | industry compilation |
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 |
|---|---|
| CFR | Code of Federal Regulations |
| DOE | US Department of Energy |
| EO | executive order |
| HALEU | high-assay low-enriched uranium |
| HTR-PM | high-temperature gas-cooled reactor pebble-bed module |
| IAEA | International Atomic Energy Agency |
| LEU | low-enriched uranium |
| MWe | megawatts of electrical output |
| NRC | US Nuclear Regulatory Commission |
| SMR | small modular reactor |
| SWU | separative work unit |
| STUK | Finnish radiation and nuclear safety authority |
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-XT15-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 reactor and fuel supply clusters | 2027 |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition: enrichment capacity
- Construct
- annual separative work capacity of uranium enrichment plants, by operator
- Unit
- million separative work units (SWU) a year
- Method
- operator capacity as compiled in a 2025 industry fuel report and shown on the page
- Source
- World Nuclear Association enrichment page12
- Uncertainty
- China values are estimates that assume enough capacity is built for its domestic fleet
- Known limits
- capacity is not output; shares are derived by the editors, method (1)
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
- 15World Nuclear Association (ed.), Nuclear Power in the USA (country profile; 94 operable reactors, 96,952 MWe; Vogtle 3 and 4 cost estimates; Kemmerer permit March 2026; Clinch River construction licence September 2026; Palisades and Crane restart status; page states three reactors critical by July 2026). World Nuclear Association, London. Observation year 2026. Accessed 2026-11-03.back
- 17World Nuclear Association (ed.), Nuclear Power in the United Kingdom (country profile, first 100,000 characters read; Rolls-Royce SMR delivery contract April 2026 for three Wylfa units with up to GBP 599 million loan financing; Hinkley Point C GBP 35 billion in 2015 prices, February 2026; Sizewell C). World Nuclear Association, London. Observation year 2026. Accessed 2026-11-03.back
- 25Steigerwald, B., Weibezahn, J., Slowik, M. and von Hirschhausen, C., Uncertainties in estimating production costs of future nuclear technologies: a model-based analysis of small modular reactors, Energy 281, 128204, 2023 (abstract page read). Elsevier, Amsterdam. Observation year 2023. Accessed 2026-11-03.back
- 11US Department of Energy, Office of Nuclear Energy (ed.), What is high-assay low-enriched uranium (HALEU)? (article of 3 December 2024; enrichment 5% to less than 20% U-235; demand could reach 50 metric tons a year by 2035; Piketon more than 100 kg enriched). US Department of Energy, Washington. Observation year 2024. Accessed 2026-11-03.back
- 2UNVERIFIED, not opened: IAEA (ed.), Energy, Electricity and Nuclear Power Estimates for the Period up to 2050, 2025 edition (377 GW at end of 2024; high case 992 GW and low case 561 GW in 2050), taken from search-result summaries of trade reports; the IAEA page was not retrieved. International Atomic Energy Agency, Vienna. Observation year 2025. Accessed 2026-11-03.back
- 5UNVERIFIED, not opened: The White House (ed.), Reforming Nuclear Reactor Testing at the Department of Energy, Executive Order 14301, 23 May 2025, the page address returned not found; the goal of three reactors achieving criticality by 4 July 2026 is taken from the American Nuclear Society report. The White House, Washington. Observation year 2025. Accessed 2026-11-03.back
- 6American Nuclear Society (ed.), The deadline arrives: checking in on the Reactor Pilot Program (news article, 2 July 2026; criticality by Antares 4 June, Valar 18 June, Deployable Energy 1 July; ten companies selected in August 2025; status of the remaining participants). American Nuclear Society, La Grange Park. Observation year 2026. Accessed 2026-11-03.back
- 18World Nuclear Association (ed.), Nuclear Power in China (country profile, first 100,000 characters read; 65 reactors, 65,085 MWe operable; 39 under construction; HTR-PM commercial operation December 2023; Linglong One commissioning expected during 2026; 110 GWe target by 2030). World Nuclear Association, London. Observation year 2026. Accessed 2026-11-03.back
- 29UNVERIFIED, not opened: OECD Nuclear Energy Agency (ed.), The NEA Small Modular Reactor Dashboard, second edition, the page returned a service error; no figure from it is used. OECD NEA, Paris. Observation year 2024. Accessed 2026-11-03.back
- 42UNVERIFIED, not opened: IAEA (ed.), Advances in Small Modular Reactor Technology Developments, 2022 edition, cited from memory without a figure. International Atomic Energy Agency, Vienna. Observation year 2022. Accessed 2026-11-03.back
- 30UNVERIFIED, not opened: OECD NEA and IAEA (eds.), Uranium 2024: Resources, Production and Demand, the page returned forbidden; no figure from it is used. OECD NEA, Paris. Observation year 2025. Accessed 2026-11-03.back
- 35UNVERIFIED, not opened: UNECE (ed.), Life Cycle Assessment of Electricity Generation Options, 2021, the page returned forbidden; no figure from it is used. United Nations Economic Commission for Europe, Geneva. Observation year 2021. Accessed 2026-11-03.back
- 36UNVERIFIED, not opened: IPCC (ed.), Climate Change 2022: Mitigation of Climate Change, Working Group III, chapter 6, the page returned forbidden; no figure from it is used. Intergovernmental Panel on Climate Change, Geneva. Observation year 2022. Accessed 2026-11-03.back
- 14World Nuclear Association (ed.), Nuclear Power in Canada (country profile; Darlington BWRX-300, construction licence April 2025, first nuclear concrete 26 June 2026, operation expected 2030, CAD 20.9 billion for four units; page lists 316 MWe gross and describes 300 MWe). World Nuclear Association, London. Observation year 2026. Accessed 2026-11-03.back
- 31UNVERIFIED, not opened: US Nuclear Regulatory Commission (ed.), NuScale US460 standard design approval page, the page address returned not found; the approval is cited from memory without a figure. US NRC, Rockville. Observation year 2025. Accessed 2026-11-03.back
- 38UNVERIFIED, not opened: US Nuclear Regulatory Commission (ed.), Kairos Power Hermes test reactor licensing page, the page address returned not found; no figure from it is used. US NRC, Rockville. Observation year 2025. Accessed 2026-11-03.back
- 39UNVERIFIED, not opened: Ontario Power Generation (ed.), Darlington New Nuclear Project page, the page returned forbidden; Darlington figures are taken from the World Nuclear Association country profile. OPG, Toronto. Observation year 2026. Accessed 2026-11-03.back
- 8US Department of Energy, Office of Nuclear Energy (ed.), NRC Issues Construction Permit for TerraPower’s Natrium Advanced Reactor (article, 9 March 2026; 345 MWe sodium-cooled fast reactor, storage lifts output to 500 MW; Kemmerer Unit 1, Wyoming; operating licence separate). US Department of Energy, Washington. Observation year 2026. Accessed 2026-11-03.back
- 12World Nuclear Association (ed.), Uranium Enrichment (information library page; capacity table from the WNA Nuclear Fuel Report 2025: 68.076 million SWU in 2025, Rosatom 29.133, Urenco 17.300, CNNC 13.789 estimated, Orano 7.500; US ban on Russian low-enriched uranium from August 2024). World Nuclear Association, London. Observation year 2025. Accessed 2026-11-03.back
- 10US Nuclear Regulatory Commission (ed.), 10 CFR Part 53 rulemaking page (final rule 91 FR 15696; risk-informed, performance-based, technology-inclusive framework; background in NEIMA and the ADVANCE Act). US Nuclear Regulatory Commission, Rockville. Observation year 2026. Accessed 2026-11-03.back