Reactor Parameter Analysis
Browser-based implementation of the Nuclear Reactor Directory Project (NRDP): a citation-backed reactor database and weighted comparison engine from Calhoun & Eckert (2024), published in the Countering WMD Journal. Filter 65 documented reactors, review summary statistics, and rank units against the parameters you specify.
Background
The Nuclear Reactor Directory Project (NRDP) was proposed in A Unique Solution to Nuclear Reactor Parameter Centralization: Streamlining the Search and Analysis of WMD Reactors of Concern (Aaron Calhoun & Matthew Eckert; Countering WMD Journal, 27th Edition, 2024). The article argues that researchers studying reactor design and counter-proliferation need a reactor-centric database — not just power-plant summaries — with external citations, exportable parameter tables, and quantitative comparison tooling.
Calhoun and Eckert identify four gaps in systems such as IAEA ARIS/PRIS and the World Nuclear Association reactor listings:
- Reactor parameters are updated irregularly in existing registries.
- External citations beyond the parent organization are rarely attached to entries.
- There is little tooling to quantitatively compare reactor characteristics.
- Parameter exports for offline analysis are limited (often PDF-only).
NRDP responds with an open, citation-backed directory: reactors as rows, characteristics as columns, split into quantitative (numeric) and qualitative (categorical) fields, plus a weighted scoring engine to rank how closely each unit matches a researcher's desired specification. An early desktop prototype (Nuclear-Reactor-Database-Dataframe-Analysis-Program, tkinter + pandas) implemented the database and GUI described in the paper's appendices. This ReactorMC page is a public, client-side realization of the same idea — no login, every row links to its primary source, and all scoring runs in the browser on the filtered set.
Primary source: Countering WMD Journal, Issue 27 PDF (pp. 62–65) · Journal archives (fallback)
Weighted comparison method
The similarity finder below implements the NRDP scoring flow from Calhoun & Eckert (2024). You pick characteristics, assign relative weights, and enter desired values. Each reactor receives a 0–100 match score; higher means closer to your target.
Step 1 — normalize weights
Relative user weights W_i^raw become normalized factors W_i that sum to 1.
Step 2a — quantitative deviation
v_d is your desired value; v_r is the reactor's published value. Absolute percent deviation from the target.
Step 2b — qualitative deviation
Categorical fields (class, coolant, moderator, fuel) use binary match / no-match.
Step 3 — characteristic sub-score
Each characteristic maps to a 0–100 similarity sub-score. Quantitative d is clamped at 1 so scores never go negative.
Step 4 — total score
The reactor's overall match score is the weighted sum of sub-scores. Reactors are ranked by S_n (highest first).
ReactorMC adaptation: if a reactor lacks a value for a selected quantitative field, that characteristic is skipped and remaining weights are renormalized across scorable fields only — missing data neither helps nor penalizes a unit. Scores always apply to the currently filtered list. See the original paper for GUI screenshots and the EGP-6 reference comparison in Appendix B.
Filter the database
Summary statistics
Reactors (filtered)
65
of 65 total
Mean thermal power
1,596.9
65 with data · MWth
Median thermal power
870
MWth
Range
1–4,590
MWth
Reactors by class
PWR
23
SFR
11
PHWR
7
BWR
5
HTGR
5
Research
5
LWGR
4
GCR
2
MSR
2
LFR
1
World map
Plant-site markers for the filtered reactor set. Click a pin to jump to that reactor in the table below.
- Operational
- Under Construction
- Under Development
- Shutdown
Find the best-matching reactor
Enable the characteristics you care about, set a desired value, and assign a relative weight. Each reactor gets a 0–100 match score using the NRDP method above (see Step 3–4). Scores apply to the currently filtered list.
Reactor database (65)
| # | Reactor | Design | Country | Class | Coolant | Moderator | Fuel | MWth | MWe | Enr% | P MPa | T out | Cycle | Pos. | Operator | Crit. | Status | Source | Source 2 | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | ACP100 (Linglong One) | Integral SMR | China | PWR | Light water | Light water | UO₂ | 385 | 125 | 4 | — | — | — | — | — | — | Under Construction | IAEA ARIS — SMR Catalogue 2024 (ACP100) | — | Integral PWR SMR under construction at Changjiang, Hainan. |
| 2 | Advanced Test Reactor (ATR) | Serpentine flux-trap test reactor | United States | Research | Light water | Light water | U-Al (HEU plate) | 250 | — | 93 | — | — | — | — | — | 1967 | Operational | US NRC / INL — ATR | — | High-flux materials-test reactor at Idaho National Laboratory. |
| 3 | Ascó 2 | Westinghouse 3-loop | Spain | PWR | Light water | Light water | UO₂ | 2,941 | 1,027 | — | — | — | — | — | Asociación Nuclear Ascó-Vandellós (Anav) | 1985 | Operational | IAEA PRIS — Ascó 2 | WNA — Spain profile | — |
| 4 | Atucha 1 | Siemens KWU PHWR | Argentina | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | UO₂ (slightly enriched) | 1,179 | 362 | 0.85 | — | — | — | — | — | 1974 | Operational | WNA — Argentina profile | — | Originally natural U; converted to ~0.85% slightly-enriched U. |
| 5 | AVR Jülich | Pebble-bed prototype | Germany | HTGR | Helium | Graphite | TRISO (HEU/Th) | 46 | 15 | — | — | — | — | — | — | 1966 | Shutdown | WNA — Small reactors | — | First pebble-bed reactor. Shut 1988. |
| 6 | Barakah 1 | APR-1400 | United Arab Emirates | PWR | Light water | Light water | UO₂ | 3,983 | 1,345 | 4 | — | — | — | — | — | 2020 | Operational | WNA — UAE profile | — | First nuclear power reactor in the Arab world. |
| 7 | Beznau 1 | Westinghouse 2-loop | Switzerland | PWR | Light water | Light water | UO₂ | 1,130 | 380 | — | — | — | — | — | Axpo (Kernkraftwerk Beznau) | 1969 | Operational | IAEA PRIS — Beznau 1 | ENSI — Swiss nuclear regulator | Among the oldest operating PWRs worldwide; twin unit on the Aare River. |
| 8 | BN-600 | BN-600 | Russia | SFR | Liquid sodium | None (fast spectrum) | UO₂ (HEU) | 1,470 | 600 | 21 | — | — | — | — | — | 1980 | Operational | WNA — Fast neutron reactors | — | Long-running commercial fast reactor (Beloyarsk 3). Mixed-enrichment UO₂ zones (~17–26%). |
| 9 | BN-800 | BN-800 | Russia | SFR | Liquid sodium | None (fast spectrum) | MOX / UO₂ | 2,100 | 880 | — | — | — | — | — | — | 2014 | Operational | WNA — Fast neutron reactors | — | Beloyarsk 4; transitioning to a full MOX core. |
| 10 | BREST-OD-300 | BREST-OD-300 | Russia | LFR | Liquid lead | None (fast spectrum) | Mixed U-Pu nitride | 700 | 300 | — | — | — | — | — | — | — | Under Construction | WNA — Fast neutron reactors (BREST-OD-300) | — | Lead-cooled fast reactor under construction at Seversk, Russia. |
| 11 | Browns Ferry 1 | BWR/4 (Mark I) | United States | BWR | Light water | Light water | UO₂ | 3,952 | 1,310 | 3.5 | — | — | — | — | — | 1973 | Operational | WNA — Browns Ferry 1 | — | — |
| 12 | BWRX-300 | SMR (GE Hitachi) | United States / Canada | BWR | Light water | Light water | UO₂ | 870 | 300 | 4 | — | — | — | — | — | — | Under Construction | GE Vernova — BWRX-300 | — | First unit under construction at Darlington, Canada. |
| 13 | Calder Hall 1 | Magnox | United Kingdom | GCR | Carbon dioxide (CO₂) | Graphite | Natural U metal | 182 | 50 | 0.71 | — | — | — | — | — | 1956 | Shutdown | WNA — UK profile | — | First industrial-scale power station to deliver to a grid. Shut 2003. |
| 14 | CEFR | China Experimental Fast Reactor | China | SFR | Liquid sodium | None (fast spectrum) | UO₂ (HEU) | 65 | 20 | — | — | — | — | — | — | 2010 | Operational | WNA — China profile (CEFR) | — | — |
| 15 | Cernavodă 1 | CANDU 6 | Romania | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | Natural UO₂ | 2,064 | 706 | 0.71 | — | — | — | — | — | 1996 | Operational | WNA — Romania profile | — | — |
| 16 | Chernobyl 4 | RBMK-1000 | Ukraine | LWGR | Light water | Graphite | UO₂ | 3,200 | 1,000 | 2 | — | — | — | — | — | 1983 | Shutdown | WNA — Chernobyl accident | — | Destroyed in the 1986 accident. |
| 17 | Darlington 1 | CANDU (850 MWe class) | Canada | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | Natural UO₂ | 2,776 | 935 | 0.71 | — | — | — | — | — | 1990 | Operational | WNA — Canada profile | — | — |
| 18 | Dresden 1 | Early GE BWR | United States | BWR | Light water | Light water | UO₂ | 700 | 197 | — | — | — | — | — | — | 1959 | Shutdown | WNA — USA profile | — | First privately-financed US commercial reactor. Shut 1978. |
| 19 | EBR-I | Experimental Breeder Reactor I | United States | SFR | NaK eutectic | None (fast spectrum) | U metal (HEU) | 1.4 | 0.2 | — | — | — | — | — | — | 1951 | Shutdown | US NRC — EBR-I historical record | — | First reactor to generate usable electricity (Dec 1951). Now a museum. |
| 20 | EBR-II | Experimental Breeder Reactor II | United States | SFR | Liquid sodium | None (fast spectrum) | U-Zr metal (HEU) | 62.5 | 20 | — | — | — | — | — | — | 1964 | Shutdown | WNA — Fast neutron reactors (EBR-II) | — | Demonstrated the Integral Fast Reactor concept. Shut 1994. |
| 21 | EGP-6 (Bilibino) | EGP-6 | Russia | LWGR | Light water (boiling) | Graphite | UO₂ | 62 | 11 | 3 | — | — | — | — | — | 1973 | Shutdown | WNA — Russia profile | — | Small graphite-moderated cogeneration units at Bilibino, Arctic Russia. Used as the reference comparison reactor in the Calhoun & Eckert NRDP prototype. |
| 22 | Fangchenggang 3 | HPR1000 (Hualong One) | China | PWR | Light water | Light water | UO₂ | 3,150 | 1,180 | — | 15.5 | 328.5 | — | 177 | Guangxi Fangchenggang Nuclear Power Co. | 2022 | Operational | IAEA PRIS — Fangchenggang 3 | CGN / JAIF — Hualong One design parameters | First of two HPR1000 units at Fangchenggang Phase II. RCS outlet/inlet 328.5 / 291.5 °C and 177 assemblies from Hualong One design summaries. |
| 23 | Fangchenggang 4 | HPR1000 (Hualong One) | China | PWR | Light water | Light water | UO₂ | 3,150 | 1,180 | — | 15.5 | 328.5 | — | 177 | Guangxi Fangchenggang Nuclear Power Co. | 2024 | Operational | IAEA PRIS — Fangchenggang 4 | CGN / JAIF — Hualong One design parameters | Twin HPR1000 to Unit 3; commercial operation May 2024 (IAEA RDS-2, 2025). |
| 24 | Flamanville 3 | EPR | France | PWR | Light water | Light water | UO₂ | 4,500 | 1,630 | 4 | — | — | — | — | — | 2024 | Operational | WNA — France profile | — | — |
| 25 | Fort St. Vrain | Prismatic HTGR | United States | HTGR | Helium | Graphite | TRISO (HEU/Th carbide) | 842 | 330 | — | — | — | — | — | — | 1974 | Shutdown | WNA — USA profile | — | Only US commercial-scale HTGR. Shut 1989. |
| 26 | HFIR | High Flux Isotope Reactor | United States | Research | Light water | Light water / beryllium | U₃O₈-Al (HEU) | 85 | — | 93 | — | — | — | — | — | 1965 | Operational | ORNL — HFIR | — | One of the highest steady-state neutron fluxes in the world. |
| 27 | Hinkley Point B (R3) | AGR | United Kingdom | GCR | Carbon dioxide (CO₂) | Graphite | UO₂ | 1,500 | 610 | 2.6 | — | — | — | — | — | 1976 | Shutdown | WNA — UK profile | — | Advanced Gas-cooled Reactor. Shut 2022. |
| 28 | HTR-PM | Pebble-bed (Shidaowan) | China | HTGR | Helium | Graphite | TRISO (UO₂) | 500 | 210 | 8.5 | — | — | — | — | — | 2021 | Operational | WNA — China profile (HTR-PM) | — | Twin 250 MWth pebble-bed modules driving one turbine. World's first commercial HTGR (2023). |
| 29 | HTTR | Prismatic test reactor | Japan | HTGR | Helium | Graphite | TRISO (UO₂) | 30 | — | 6 | — | — | — | — | — | 1998 | Operational | WNA — Japan profile (HTTR) | — | Reached 950 °C coolant outlet; used for hydrogen-production R&D. |
| 30 | Joyo | Experimental SFR (MK-III core) | Japan | SFR | Liquid sodium | None (fast spectrum) | MOX | 140 | — | — | — | 500 | — | — | Japan Atomic Energy Agency (JAEA) | 1977 | Shutdown | JAEA — Joyo MK-III core data | JAEA — Joyo user's guide | MK-III rated 140 MWt (outlet 500 °C). No electricity generation. Out of service since 2007; regulatory restart (MK-IV, ~100 MWt) pending as of 2026. |
| 31 | Kaiga 1 | IPHWR-220 | India | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | Natural UO₂ | 801 | 220 | 0.71 | 8.53 | 293.4 | 24 | 306 | Nuclear Power Corporation of India Ltd. (NPCIL) | 2000 | Operational | IAEA PRIS — Kaiga 1 | WNA — India profile (IPHWR-220) | 306 horizontal pressure tubes per ARIS IPHWR-220 (RAPS-3&4 reference design). Primary pressure 87 kg/cm² (g) ≈ 8.53 MPa from IPHWR-220 design tables. |
| 32 | Kashiwazaki-Kariwa 6 | ABWR | Japan | BWR | Light water | Light water | UO₂ | 3,926 | 1,356 | 3.5 | — | — | — | — | — | 1996 | Operational | US NRC — ABWR design certification | — | One of the first ABWRs to enter service. |
| 33 | KLT-40S (Akademik Lomonosov) | Floating SMR (icebreaker-derived) | Russia | PWR | Light water | Light water | UO₂ | 150 | 35 | 18.6 | — | — | — | — | — | 2018 | Operational | IAEA ARIS — SMR Catalogue 2024 (KLT-40S) | — | Two reactors aboard the world's first floating NPP. ~2×35 MWe. |
| 34 | Koeberg 1 | Framatome CP1 (2-loop) | South Africa | PWR | Light water | Light water | UO₂ | 2,775 | 964 | — | — | — | — | — | Eskom | 1984 | Operational | IAEA PRIS — Koeberg 1 | WNA — South Africa profile | Africa's only nuclear power station; twin CP1 PWR on the Atlantic coast. |
| 35 | Leningrad 1 | RBMK-1000 | Russia | LWGR | Light water | Graphite | UO₂ | 3,200 | 1,000 | 2 | — | — | — | — | — | 1973 | Shutdown | WNA — RBMK reactors | — | First RBMK-1000. Enrichment raised over time (~2.0–2.8%). Shut 2018. |
| 36 | Loviisa 1 | VVER-440 (V-213) | Finland | PWR | Light water | Light water | UO₂ | 1,500 | 507 | 3.6 | — | — | — | — | — | 1977 | Operational | WNA — Finland profile | — | — |
| 37 | MIT Reactor (MITR-II) | Tank-in-pool | United States | Research | Light water | Light water / D₂O | U-Al (HEU plate) | 6 | — | 93 | — | — | — | — | — | 1975 | Operational | MIT — Nuclear Reactor Laboratory | — | University research reactor (MITR-II uprate of the 1958 MITR-I). |
| 38 | Monju | Prototype FBR | Japan | SFR | Liquid sodium | None (fast spectrum) | MOX | 714 | 280 | — | — | — | — | — | — | 1994 | Shutdown | WNA — Japan profile | — | Decommissioning began 2018 after a sodium-leak history. |
| 39 | MSRE | Molten-Salt Reactor Experiment | United States | MSR | Molten fluoride salt (FLiBe) | Graphite | Dissolved U-235 / U-233 fluoride | 7.4 | — | — | — | — | — | — | — | 1965 | Shutdown | ORNL — Molten Salt Reactor | — | Landmark ORNL experiment; ran on U-235 then U-233 fuel salt. Shut 1969. |
| 40 | Natrium | TerraPower Natrium | United States | SFR | Liquid sodium | None (fast spectrum) | Metallic HALEU | 840 | 345 | 15 | — | — | — | — | — | — | Under Construction | TerraPower — Natrium | — | Pool-type SFR with molten-salt thermal storage (up to ~500 MWe peak). HALEU ~5–20%. Under construction at Kemmerer, Wyoming. |
| 41 | Novovoronezh II-1 | VVER-1200 (AES-2006) | Russia | PWR | Light water | Light water | UO₂ | 3,200 | 1,200 | 4 | — | — | — | — | — | 2016 | Operational | Rosatom — VVER-1200 | — | Reference plant for the VVER-1200/V-491 line. |
| 42 | NuScale Power Module | Integral SMR (VOYGR) | United States | PWR | Light water | Light water | UO₂ | 250 | 77 | 4.95 | — | — | — | — | — | — | Under Development | IAEA ARIS — SMR Catalogue 2024 (NuScale) | — | Natural-circulation integral PWR; US NRC-certified design (uprated to 77 MWe/module). |
| 43 | Obninsk AM-1 | AM-1 ('Atom Mirny') | Russia | LWGR | Light water | Graphite | U metal (enriched) | 30 | 5 | 5 | — | — | — | — | — | 1954 | Shutdown | WNA — History of nuclear energy | — | First reactor to supply electricity to a grid (1954). Shut 2002. |
| 44 | Olkiluoto 3 | EPR | Finland | PWR | Light water | Light water | UO₂ | 4,300 | 1,600 | 4 | — | — | — | — | — | 2021 | Operational | WNA — Finland profile | — | Grid connection 2022, commercial operation 2023. |
| 45 | OPAL | Open-pool (INVAP) | Australia | Research | Light water | Light water | U₃Si₂-Al (LEU) | 20 | — | 19.75 | — | — | — | — | — | 2006 | Operational | ANSTO — OPAL | — | LEU open-pool reactor for isotope production and neutron science. |
| 46 | Palo Verde 1 | CE System 80 (2-loop, dry cooling) | United States | PWR | Light water | Light water | UO₂ | 3,990 | 1,414 | — | — | — | — | — | Arizona Public Service Co. | 1985 | Operational | IAEA PRIS — Palo Verde 1 | WNA — Palo Verde 1 | Largest US nuclear plant by output; unique desert dry-cooled site. |
| 47 | Phénix | Phénix | France | SFR | Liquid sodium | None (fast spectrum) | MOX | 563 | 250 | — | — | — | — | — | — | 1973 | Shutdown | WNA — Fast neutron reactors | — | Long-running French prototype fast reactor. Shut 2009. |
| 48 | Point Lepreau | CANDU 6 | Canada | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | Natural UO₂ | 2,064 | 660 | 0.71 | — | — | — | — | — | 1982 | Operational | WNA — Canada profile | — | — |
| 49 | Qinshan Phase III-1 | CANDU 6 | China | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | Natural UO₂ | 2,064 | 728 | 0.71 | — | — | — | — | — | 2002 | Operational | WNA — China profile | — | — |
| 50 | Rapsodie | Loop-type experimental SFR | France | SFR | Liquid sodium | None (fast spectrum) | MOX / UO₂ | 40 | — | — | — | 550 | — | — | CEA Cadarache | 1967 | Shutdown | IPFM — Fast Breeder Reactor Programs (Rapsodie history) | CEA — Rapsodie stage-2 dismantling report (OSTI) | France's first fast reactor; 40 MWt after 1970 core redesign. Permanent shutdown 15 Apr 1983 (sodium microleak). Outlet ~550 °C in representative commercial conditions (WNA/CEA summaries). |
| 51 | Ringhals 3 | Westinghouse 3-loop | Sweden | PWR | Light water | Light water | UO₂ | 3,135 | 1,128 | — | — | — | — | — | Ringhals AB (Vattenfall / Uniper) | 1980 | Operational | IAEA PRIS — Ringhals 3 | WNA — Sweden profile | Sweden's only remaining PWR after Ringhals 1–2 BWRs shut; uprated over its lifetime. |
| 52 | Shin Kori 3 | APR-1400 | South Korea | PWR | Light water | Light water | UO₂ | 3,983 | 1,400 | 4 | — | — | — | — | — | 2015 | Operational | US NRC — APR-1400 design certification | — | — |
| 53 | Shippingport | First US commercial PWR | United States | PWR | Light water | Light water | UO₂ / seed-blanket | 236 | 60 | — | — | — | — | — | — | 1957 | Shutdown | OSTI — Shippingport Atomic Power Station | — | First full-scale US commercial PWR; later ran as a light-water breeder (Th/U-233). Shut 1982. |
| 54 | Sizewell B | SNUPPS-derived 4-loop | United Kingdom | PWR | Light water | Light water | UO₂ | 3,425 | 1,198 | 3.5 | — | — | — | — | — | 1995 | Operational | WNA — UK profile | — | — |
| 55 | SMART | Integral SMR | South Korea | PWR | Light water | Light water | UO₂ | 365 | 100 | 4.8 | — | — | — | — | — | — | Under Development | IAEA ARIS — SMR Catalogue 2024 (SMART) | — | KAERI integral PWR; standard design approval granted in Korea. |
| 56 | Superphénix | SPX-1 | France | SFR | Liquid sodium | None (fast spectrum) | MOX | 2,990 | 1,242 | — | — | — | — | — | — | 1985 | Shutdown | WNA — Fast neutron reactors | — | Largest fast reactor ever built. Shut 1998. |
| 57 | Taishan 1 | EPR | China | PWR | Light water | Light water | UO₂ | 4,590 | 1,660 | 4 | — | — | — | — | — | 2018 | Operational | WNA — China profile | — | First EPR to enter commercial operation worldwide. |
| 58 | Tarapur 1 | BWR-1 (Mark 2) | India | BWR | Light water | Light water | UO₂ | 530 | 160 | — | — | — | — | — | Nuclear Power Corporation of India Ltd. (NPCIL) | 1969 | Operational | IAEA PRIS — Tarapur 1 | WNA — India profile | First commercial nuclear power units in India (with Tarapur 2). Suspended Jan 2020–Jan 2026 for recirculation-system repairs; PRIS lists return to operation Jan 2026. |
| 59 | Temelín 1 | VVER-1000 (V-320) | Czech Republic | PWR | Light water | Light water | UO₂ | 3,000 | 1,080 | 4 | — | — | — | — | — | 2000 | Operational | WNA — Czech Republic profile | — | — |
| 60 | TMSR-LF1 | Liquid-fuel thorium MSR | China | MSR | Molten fluoride salt | Graphite | Dissolved U/Th fluoride | 2 | — | — | — | — | — | — | — | 2023 | Operational | WNA — Molten salt reactors | — | Experimental 2 MWth thorium MSR at Wuwei; first MSR criticality since MSRE. |
| 61 | TRIGA Mark II | TRIGA (General Atomics) | United States | Research | Light water | U-ZrH (inherent) / water | U-ZrH (LEU) | 1 | — | 19.75 | — | — | — | — | — | 1960 | Operational | General Atomics — TRIGA | — | Representative of the widely-deployed TRIGA family; inherently safe via prompt negative fuel temperature coefficient. Powers vary 0.1–14 MWth by site. |
| 62 | Vogtle 3 | AP1000 | United States | PWR | Light water | Light water | UO₂ | 3,415 | 1,117 | 4.5 | — | — | — | — | — | 2023 | Operational | Westinghouse AP1000 | — | First newly-built US reactor in ~30 years; enrichment nominal ≤4.95%. |
| 63 | Watts Bar 2 | Westinghouse 4-loop (ICECND) | United States | PWR | Light water | Light water | UO₂ | 3,411 | 1,218 | — | — | — | — | — | Tennessee Valley Authority | 2016 | Operational | IAEA PRIS — Watts Bar 2 | WNA — USA profile | Construction started 1973, suspended 1985, restarted 2007; last new US PWR grid connection before Vogtle 3–4. |
| 64 | Wolsong 1 | CANDU 6 | South Korea | PHWR | Heavy water (D₂O) | Heavy water (D₂O) | Natural UO₂ | 2,061 | 683 | 0.71 | 10 | — | — | 380 | Korea Hydro & Nuclear Power (KHNP) | 1982 | Shutdown | IAEA PRIS — Wolsong 1 | WNA — Canada profile (CANDU 6) | First CANDU in Korea; permanently shut 24 Dec 2019 (PRIS). 380 fuel channels per CANDU 6 standard design. |
| 65 | Xe-100 | X-energy pebble-bed SMR | United States | HTGR | Helium | Graphite | TRISO (UCO, HALEU) | 200 | 80 | 15.5 | — | — | — | — | — | — | Under Development | X-energy — Xe-100 | — | Four-pack design selected for a Dow Seadrift, Texas project. HALEU ~15.5%. |
Scoring follows the NRDP weighted-similarity method (Calhoun & Eckert, 2024). Figures are headline reference values from the cited sources; "—" means the value is not reliably published for that unit and is omitted rather than estimated. Enrichment values are nominal design figures. Where two source links appear, the first is the primary operational registry (usually IAEA PRIS) and the second is a design or operator reference. This is an educational tool, not an authoritative reactor registry — verify against the linked primary sources before citing.