How the atlas is built

Reactor units follow IAEA PRIS categories as republished by the World Nuclear Association: operable means operating or in suspended operation; under construction, planned and proposed follow the WNA plans page; shut down means permanently shut down.

Node size on the reactor map scales with net MWe of the operable units at a site. Sites without published coordinates are listed in the country panel only. The timeline draws units by their year of first grid connection, or by commercial operation where the WNA table has no connection date.

Electricity mix, nuclear share and grid carbon intensity are Ember data via the Our World in Data energy dataset, latest year per country. The decarbonisation block is arithmetic on that mix with IPCC AR5 lifecycle medians, not a forecast.

Uranium production is World Nuclear Association data in tonnes of uranium (tU). Resources are the NEA/IAEA Red Book as summarised by the WNA. Price indicators are Cameco's monthly series, an industry average of the UxC and TradeTech month-end prices.

Mines and fuel-cycle facilities come from WNA country and fuel-cycle pages, the WISE Uranium Project, regulators and company reports. Coordinates cite their own source; town-level coordinates are flagged in the record notes.

Explainer facts were verified on 9 October 2026. "Primary source" means the citing page was read that day; "reputable secondary" means WNA, WNN, ANS or NucNet. Claims that could not be verified are listed in the fact base and are not shown on the site.

Chart colours were validated for colour-vision deficiency and contrast with an OKLab-based check on both surfaces; every chart has a legend or a title naming its series, a table view and a source line.

Reactor units. IAEA PRIS could not be read directly (pris.iaea.org redirects to the JavaScript-only PRIS data browser launched in August 2026); every PRIS-derived value comes via the WNA Reactor Database (accessed 2026-10-09) or GeoNuclearData (2024-03-02). PRIS world totals could therefore not be fetched; the WNA summary page totals (442 operable / 405,227 MWe; 80 under construction / 79,388 MWe) are used instead. The PRIS "Suspended Operation" flag is carried from GeoNuclearData (2024-03-02) and adjusted for documented restarts (WNA Japan profile); units that entered or left suspended status since 2024 without such documentation are not captured. Planned and proposed units: the WNA plans page publishes only per-country counts (122 planned / 336 proposed worldwide). Unit-level planned/proposed records come from WNA country profiles where fetched (see planned_units.csv) and otherwise from the 2024 GeoNuclearData "Planned" list reclassified by rule (notes say so); they are incomplete and rated low. operator is null wherever no source names it (PRIS country pages could not be read); it is filled from the WNA Japan profile, the WNA plans page and the patch sources listed in docs/data/reactors.md. gross_mwe is null except for units under construction (WNA plans page) and planned units with a WNA country-profile figure. grid_connection is only available for currently operable units; commercial_operation dates come from GeoNuclearData and are missing for units that started up after 2024-03. Xin'an HTR-PM600 units 1-2 (China): site location not confirmed; coordinates null. Cape Nagloynyn 1-2 (floating): coordinates are the approximate planned mooring site. Khmelnitski 4: WNA lists 0 MWe (placeholder); the GeoNuclearData 1035 MWe design figure is retained with a note. Baltic-1 (Russia): retained as under construction (frozen since 2013) from GeoNuclearData; not in the WNA under-construction list. CEFR (China Experimental Fast Reactor, 20 MWe) is excluded: delisted from PRIS as a research reactor (GeoNuclearData README) and absent from the WNA database. GeoNuclearData is licensed ODbL 1.0 / DbCL 1.0 (not CC BY 4.0): a derivative database must attribute it and be offered under ODbL (share-alike) - decision needed before publication.

SMR projects. CAREM-25 (Argentina): no 2025-2026 status source found; record reflects Sept 2024 halt — may be stale. Reactor Pilot Program: whether Groves Isotope Test Reactor, Last Energy PWR-5, Radiant Kaleidos, Oklo Aurora-INL or Deep Fission reached criticality after 2026-07-02 is unverified. X-energy Long Mott: NRC construction permit decision pending after 2026-09-22 hearing (record closed 2026-10-06) — check for issuance. Rolls-Royce SMR GDA Step 3 completion (due Aug 2026) and UK nuclear site licence application at Wylfa not confirmed. Russia: Baimsky floating units — delivery years, per-unit MWe (106 vs 110) and site coordinates unverified; Yakutia RITM-200N unit count (1 vs 2) and target year (2028 vs 2030) conflict between NEI and WNA. Fuel enrichment is null for most records; only HTR-PM (8.5%), NuScale (4.95% design max) and Xe-100 (15.5% design) carry figures, the latter two from developer design data not re-verified today. Darlington units 2-4: no separate cost/schedule published; CAD 20.9bn provincial budget scope (unit 1 vs four units) ambiguous in sources. Coordinates: most are site-level approximations from reference knowledge, not GIS-verified; city-centroid or null where flagged in notes. Not covered (no named site or filing found in time): Oklo Pluto, Last Energy Haskell County (TX), Westinghouse AP300 UK Teesside progress, Hyundai E&C own SMR, Copenhagen Atomics 2026 experiment outcome, Saltfoss/Seaborg funding status, Ghana project-level 2026 update. ENTRA1/TVA: 'TVA board review of SMR allocation' was reported as pending for October 2026 — verify outcome. TVO/Fortum, Helen (Finland) and other European utility SMR feasibility programmes without a selected design are not recorded.

Uranium mines. 20 mine record(s) without sourced coordinates: zhalpak, rook-i-arrow, midwest, kiggavik, michelin, mulga-rock, omahola, zhonghe, dasa, lost-creek, burke-hollow, palangana, whirlwind, roca-honda, qizilkok, tiris, novokostiantynivka, narwapahar, rohil, cerro-solo

Fuel-cycle facilities. 1 facility record(s) without sourced coordinates: turamdih-mill

Country electricity mix, latest year. Electricity columns (Ember) run to 2025 for World; latest electricity year per country (number of ISO3 countries): none: 6, 2025: 90, 2024: 106, 2023: 16, 2022: 1, 2009: 1. Primary-energy columns (Energy Institute) end in 2024 in this file; the legacy GitHub release is frozen and will not receive the Statistical Review 2026 (2025 data). Ukraine: Ember has not published country data after 2022, so the nuclear series stops in 2022. Entities without an ISO3 code other than the listed aggregates (e.g. Kosovo, OWID continents, income groups) are excluded. Ember aims to report gross generation (Eurostat annual data for Europe, incl. plant auxiliary consumption); national TSO statistics such as RTE publish net production, so country figures here can be ~5% above national statistics (see the France cross-check in docs/data/country_energy.md). Latest-year values are partly estimated by Ember from monthly data and may be revised; missing latest-year net imports are carried forward by Ember.

Deals, restarts, new builds, policy. Palisades (Holtec): fuel loading paused after a tilted fuel assembly (late Sep 2026); licence amendment under NRC review; grid synchronisation not achieved as of 2026-10-09 and no firm restart date published. Crane Clean Energy Center: NRC fuel licence amendment approved (per Constellation Q2 2026 results) but the approval date and the remaining licensing steps before the 2027 restart are not recorded as separate dated milestones. Rooppur 1: trial grid connection expected by Aug 2026 not confirmed; Akkuyu 1 start-up in 2026 (Rosatom target) not verified. Hinkley Point C: no 2025-2026 schedule/cost update recorded (latest record is EDF's 23 Jan 2024 revision). Sizewell C/EPR2: whether EDF's EPR2 final investment decision (expected late 2026) has occurred is unverified. Kozloduy 7/8: full EPC contract status after the Nov 2024 engineering contract not verified; Slovakia-Westinghouse contract after the Jan 2026 IGA not verified. Japan-US investment framework (28 Oct 2025): figures from POWER magazine only; White House fact sheet not fetched (confidence low). Kazakhstan second plant (26 Jan 2026 resolution): vendor (CNNC expected) and site details are press expectations; the official resolution text on adilet.zan.kz was not fetched. Netherlands: NEO NL FEED award date taken from WNN (26 Aug 2026); the Preferred Site Decision had not been adopted as of that report. Uranium offtake 2025-2026: only Ur-Energy's eighth agreement (5 Aug 2025) and Cameco-India (2 Mar 2026) carry disclosed terms. Paladin reports 11 contracts (~50% of Langer Heinrich life-of-mine, Jan 2025) and enCore reports deliveries under undisclosed contracts without per-contract terms; Boss Energy signed no new disclosed offtake in 2025-2026; UEC has no long-term utility contracts (its May 2026 Strategic Uranium Reserve offer is not a signed deal). No individual 2025-2026 offtake records exist for these four companies. Kazatomprom: 2026 operational guidance published with FY2025 results (early 2026) and any 2026 revisions are not recorded; the record set stops at the 22 Aug 2025 cut. Niger/Orano: ICSID arbitration outcome pending; reported 2026 sales of the blocked Somair stockpile by Niger not verified. Global Atomic: DFC facility is a board approval subject to conditions; closing not confirmed as of 2026-10-09. Meta 2026: only the 9 Jan 2026 Vistra/TerraPower/Oklo package is recorded; any later 2026 Meta nuclear agreements are not covered. Deal values: most PPAs do not disclose prices; value fields are null unless the source states an amount; no currency conversion is applied. Company slugs for nuclear-side companies follow the agreed convention; seven of them (holtec, westinghouse, tva, opg, rolls-royce-smr, cgn, cnnc) are shorter than the ids in data/companies_nuclear.json and are mapped to them on the site (D56); 47 slugs name parties without a company record (hyperscalers, utilities, state bodies, project companies).