Nuclear reactor vendors
The nuclear steam supply system (NSSS) suppliers of every unit, as recorded in the IAEA's PRIS and expanded in table 25 of Nuclear Power Reactors in the World 2025, grouped by company. Each vendor links to all its units and, where it also designs research reactors, to those reactors.
Westinghouse
90 units · 12 countries
Origin of the commercial pressurized water reactor; its 2-, 3- and 4-loop designs and the AP1000 were built on four continents.
Rosatom (Atomenergomash, Atomstroyexport)
78 units · 11 countries
The Russian state group: Atomenergomash builds the VVER nuclear island, Atomstroyexport delivers the plants abroad and the Federal Atomic Energy Agency was its predecessor.
Framatome
73 units · 6 countries
Supplier of nearly the whole French pressurized-water fleet, from the CP0 to the EPR.
General Electric
63 units · 8 countries
Creator of the boiling water reactor; today GE Hitachi Nuclear Energy, with the ABWR and the BWRX-300.
Atomic Energy of Canada Limited
35 units · 6 countries
Designer of the CANDU, with Ontario Hydro on the Canadian plants and local partners on the exports.
Siemens / Kraftwerk Union
29 units · 6 countries
Germany's pressurized and boiling water reactors, and the pressure-vessel PHWRs at Atucha.
CNNC
23 units · 2 countries
China's state nuclear corporation, with its NPIC and SNERDI design institutes: CNP-300, CNP-600 and Hualong One.
British nuclear consortia (NPC, APC, EE/B&W/T, GEC, NNC)
23 units · 2 countries
The consortia that built Britain's Magnox and AGR stations besides TNPG: Nuclear Power Company, Atomic Power Construction, English Electric with Babcock and Taylor Woodrow, GEC and the National Nuclear Corporation.
Nuclear Power Corporation of India
22 units · 1 countries
Operator and designer of India's pressurized heavy water line, from the IPHWR-220 to the IPHWR-700.
Atomenergoexport (USSR)
20 units · 5 countries
The Soviet exporter of VVER-440 and VVER-1000 plants to central and eastern Europe.
Mitsubishi Heavy Industries
20 units · 1 countries
Supplier of Japan's pressurized water reactors, in 2-, 3- and 4-loop versions.
China First Heavy Industries
19 units · 1 countries
Maker of reactor vessels and heavy nuclear-island components for China's recent fleet.
Izhorsky Plant and Atommash (USSR)
19 units · 2 countries
The two Soviet makers of VVER-1000 vessels and heavy equipment, Izhorsky in Leningrad and Atommash in Volgodonsk, recorded as suppliers of the Ukrainian plants.
Doosan (with KOPEC)
18 units · 1 countries
Maker of the nuclear island of Korea's OPR-1000 and APR-1400, with KOPEC engineering.
Toshiba
17 units · 1 countries
One of Japan's two boiling water reactor suppliers, including the ABWR.
Combustion Engineering
15 units · 1 countries
Two-loop pressurized water reactors in the United States; its System 80 is the origin of the APR-1400.
The Nuclear Power Group
14 units · 2 countries
British consortium behind first-generation Magnox and AGR reactors.
Hitachi
13 units · 1 countries
Japan's other boiling water reactor supplier; today GE's partner in GE Hitachi.
Dongfang Electric
13 units · 1 countries
Chinese maker of nuclear-island components for the CPR-1000 and Hualong One.
Škoda
13 units · 2 countries
Czechoslovak maker of the VVER-440 units at Dukovany, Bohunice and Mochovce.
ASEA-Atom / ABB Atom
12 units · 2 countries
Sweden's and Finland's home-designed boiling water reactors.
Babcock & Wilcox
10 units · 1 countries
Pressurized water reactors with once-through steam generators; Three Mile Island among them.
Soviet nuclear ministries (Minsredmash, Minatomenergoprom)
9 units · 3 countries
The Ministry of Medium Machine Building and its successor Minatomenergoprom are recorded as suppliers of the early Soviet reactors, from Obninsk to Ignalina.
UK Atomic Energy Authority
7 units · 1 countries
Calder Hall, Chapelcross and Britain's fast reactor prototypes.
KEPCO
4 units · 1 countries
Korea's state utility, prime contractor of the four APR-1400 units at Barakah in the Emirates.
General Atomics
2 units · 1 countries
The two US high-temperature gas reactors, Peach Bottom 1 and Fort St. Vrain, and the TRIGA family of research reactors worldwide.